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| author |   hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 02:41:33 -0500 |
|---|---|---|
| committer | hongbotian <hongbo.tianhongbo@huawei.com> | 2015-11-30 02:43:36 -0500 |
| commit | 9401f816dd0d9d550fe98a8507224bde51c4b847 (patch) | |
| tree | 94f2d7a7893a787bafdca8b5ef063ea316938874 /rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp | |
| parent | e8ec7aa8e38a93f5b034ac74cebce5de23710317 (diff) | |
upload tomcat
JIRA: BOTTLENECK-7
Change-Id: I875d474869efd76ca203c30b60ebc0c3ee606d0e
Signed-off-by: hongbotian <hongbo.tianhongbo@huawei.com>
Diffstat (limited to 'rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp')
4 files changed, 2614 insertions, 0 deletions
diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/ajpv13a.html b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/ajpv13a.html new file mode 100644 index 00000000..58056035 --- /dev/null +++ b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/ajpv13a.html @@ -0,0 +1,654 @@ +<html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>The Apache Tomcat Connector - AJP Protocol Reference - AJPv13</title><meta name="author" value="danmil@shore.net"><meta name="email" value="danmil@shore.net"><meta name="author" value="Jean-Frederic Clere"><meta name="email" value="jfrederic.clere@fujitsu-siemens.com"><link href="../style.css" type="text/css" rel="stylesheet"></head><body bgcolor="#ffffff" text="#000000" link="#525D76" alink="#525D76" vlink="#525D76"><table border="0" width="100%" cellspacing="4"><!--PAGE HEADER--><tr><td colspan="2"><!--TOMCAT LOGO--><a href="http://tomcat.apache.org/"><img src="../images/tomcat.gif" align="left" alt="Apache Tomcat" border="0"></a><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="http://www.apache.org/images/asf-logo.gif" align="right" alt="Apache Logo" border="0"></a></td></tr><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><tr><!--LEFT SIDE NAVIGATION--><td width="20%" valign="top" nowrap="true"><p><strong>Links</strong></p><ul><li><a href="../index.html">Docs Home</a></li></ul><p><strong>Reference Guide</strong></p><ul><li><a href="../reference/workers.html">workers.properties</a></li><li><a href="../reference/uriworkermap.html">uriworkermap.properties</a></li><li><a href="../reference/status.html">Status Worker</a></li><li><a href="../reference/apache.html">Apache HTTP Server</a></li><li><a href="../reference/iis.html">IIS</a></li></ul><p><strong>Generic HowTo</strong></p><ul><li><a href="../generic_howto/quick.html">For the impatient</a></li><li><a href="../generic_howto/workers.html">All about workers</a></li><li><a href="../generic_howto/timeouts.html">Timeouts</a></li><li><a href="../generic_howto/loadbalancers.html">Load Balancing</a></li><li><a href="../generic_howto/proxy.html">Reverse Proxy</a></li></ul><p><strong>Webserver HowTo</strong></p><ul><li><a href="../webserver_howto/apache.html">Apache HTTP Server</a></li><li><a href="../webserver_howto/iis.html">IIS</a></li><li><a href="../webserver_howto/nes.html">Netscape/SunOne/Sun</a></li></ul><p><strong>AJP Protocol Reference</strong></p><ul><li><a href="../ajp/ajpv13a.html">AJPv13</a></li><li><a href="../ajp/ajpv13ext.html">AJPv13 Extension Proposal</a></li></ul><p><strong>Miscellaneous Documentation</strong></p><ul><li><a href="../miscellaneous/faq.html">Frequently asked questions</a></li><li><a href="../miscellaneous/changelog.html">Changelog</a></li><li><a href="http://issues.apache.org/bugzilla/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=&product=Tomcat+Connectors&long_desc_type=substring&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&keywords_type=allwords&keywords=&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&emailassigned_to1=1&emailtype1=substring&email1=&emailassigned_to2=1&emailreporter2=1&emailcc2=1&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0=">Current Tomcat Connectors bugs</a></li><li><a href="../miscellaneous/doccontrib.html">Contribute documentation</a></li><li><a href="../miscellaneous/jkstatustasks.html">JK Status Ant Tasks</a></li><li><a href="../miscellaneous/reporttools.html">Reporting Tools</a></li><li><a href="http://tomcat.apache.org/connectors-doc-archive/jk2/index.html">Old JK/JK2 documentation</a></li></ul><p><strong>News</strong></p><ul><li><a href="../news/20110701.html">2011</a></li><li><a href="../news/20100101.html">2010</a></li><li><a href="../news/20090301.html">2009</a></li><li><a href="../news/20081001.html">2008</a></li><li><a href="../news/20070301.html">2007</a></li><li><a href="../news/20060101.html">2006</a></li><li><a href="../news/20050101.html">2005</a></li><li><a href="../news/20041100.html">2004</a></li></ul></td><!--RIGHT SIDE MAIN BODY--><td width="80%" valign="top" align="left"><table border="0" width="100%" cellspacing="4"><tr><td align="left" valign="top"><h1>The Apache Tomcat Connector - AJP Protocol Reference</h1><h2>AJPv13</h2></td><td align="right" valign="top" nowrap="true"><small><a href="printer/ajpv13a.html"><img src="../images/printer.gif" border="0" alt="Printer Friendly Version"><br>print-friendly<br>version + </a></small></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Intro"><strong>Intro</strong></a></font></td></tr><tr><td><blockquote> + +<p> +The original document was written by +Dan Milstein, <author email="danmil@shore.net">danmil@shore.net</author> +on December 2000. The present document is generated out of an xml file +to allow a more easy integration in the Tomcat documentation. + +</p> + +<p> +This describes the Apache JServ Protocol version 1.3 (hereafter +<b>ajp13</b>). There is, apparently, no current documentation of how the +protocol works. This document is an attempt to remedy that, in order to +make life easier for maintainers of JK, and for anyone who wants to +port the protocol somewhere (into jakarta 4.x, for example). +</p> + +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="author"><strong>author</strong></a></font></td></tr><tr><td><blockquote> + +<p> +I am not one of the designers of this protocol -- I believe that Gal +Shachor was the original designer. Everything in this document is derived +from the actual implementation I found in the tomcat 3.x code. I hope it +is useful, but I can't make any grand claims to perfect accuracy. I also +don't know why certain design decisions were made. Where I was able, I've +offered some possible justifications for certain choices, but those are +only my guesses. In general, the C code which Shachor wrote is very clean +and comprehensible (if almost totally undocumented). I've cleaned up the +Java code, and I think it's reasonably readable. +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Design Goals"><strong>Design Goals</strong></a></font></td></tr><tr><td><blockquote> + +<p> +According to email from Gal Shachor to the jakarta-dev mailing list, +the original goals of <b>JK</b> (and thus <b>ajp13</b>) were to extend +<b>mod_jserv</b> and <b>ajp12</b> by (I am only including the goals which +relate to communication between the web server and the servlet container): + +<ul> + <li> Increasing performance (speed, specifically). </li> + + <li> Adding support for SSL, so that <b class="code">isSecure()</b> and + <b class="code">getScheme()</b> will function correctly within the servlet + container. The client certificates and cipher suite will be + available to servlets as request attributes. </li> + +</ul> +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Overview of the protocol"><strong>Overview of the protocol</strong></a></font></td></tr><tr><td><blockquote> + +<p> +The <b>ajp13</b> protocol is packet-oriented. A binary format was +presumably chosen over the more readable plain text for reasons of +performance. The web server communicates with the servlet container over +TCP connections. To cut down on the expensive process of socket creation, +the web server will attempt to maintain persistent TCP connections to the +servlet container, and to reuse a connection for multiple request/response +cycles. +</p><p> +Once a connection is assigned to a particular request, it will not be +used for any others until the request-handling cycle has terminated. In +other words, requests are not multiplexed over connections. This makes +for much simpler code at either end of the connection, although it does +cause more connections to be open at once. +</p><p> +Once the web server has opened a connection to the servlet container, +the connection can be in one of the following states: +</p><p> +<ul> + <li> Idle <br> No request is being handled over this connection. </li> + <li> Assigned <br> The connecton is handling a specific request.</li> +</ul> + +</p><p> +Once a connection is assigned to handle a particular request, the basic +request informaton (e.g. HTTP headers, etc) is sent over the connection in +a highly condensed form (e.g. common strings are encoded as integers). +Details of that format are below in Request Packet Structure. If there is a +body to the request (content-length > 0), that is sent in a separate +packet immediately after. +</p><p> +At this point, the servlet container is presumably ready to start +processing the request. As it does so, it can send the +following messages back to the web server: + +<ul> + <li>SEND_HEADERS <br>Send a set of headers back to the browser.</li> + + <li>SEND_BODY_CHUNK <br>Send a chunk of body data back to the browser.</li> + + <li>GET_BODY_CHUNK <br>Get further data from the request if it hasn't all + been transferred yet. This is necessary because the packets have a fixed + maximum size and arbitrary amounts of data can be included the body of a + request (for uploaded files, for example). (Note: this is unrelated to + HTTP chunked tranfer).</li> + + <li>END_RESPONSE <br> Finish the request-handling cycle.</li> +</ul> +</p><p> + +Each message is accompanied by a differently formatted packet of data. See +Response Packet Structures below for details. +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Basic Packet Structure"><strong>Basic Packet Structure</strong></a></font></td></tr><tr><td><blockquote> + +<p> +There is a bit of an XDR heritage to this protocol, but it differs in +lots of ways (no 4 byte alignment, for example). +</p><p> +Byte order: I am not clear about the endian-ness of the individual +bytes. I'm guessing the bytes are little-endian, because that's what XDR +specifies, and I'm guessing that sys/socket library is magically making +that so (on the C side). If anyone with a better knowledge of socket calls +can step in, that would be great. +</p><p> +There are four data types in the protocol: bytes, booleans, integers and +strings. + +<dl> + <dt><b>Byte</b></dt> + <dd>A single byte.</dd> + + <dt><b>Boolean</b></dt> + <dd>A single byte, 1 = true, 0 = false. Using other non-zero values as + true (i.e. C-style) may work in some places, but it won't in + others.</dd> + + <dt><b>Integer</b></dt> + <dd>A number in the range of 0 to 2^16 (32768). Stored in 2 bytes with + the high-order byte first.</dd> + + <dt><b>String</b></dt> + <dd>A variable-sized string (length bounded by 2^16). Encoded with the + length packed into two bytes first, followed by the string (including the + terminating '\0'). Note that the encoded length does <b>not</b> include + the trailing '\0' -- it is like <b class="code">strlen</b>. This is a touch + confusing on the Java side, which is littered with odd autoincrement + statements to skip over these terminators. I believe the reason this was + done was to allow the C code to be extra efficient when reading strings + which the servlet container is sending back -- with the terminating \0 + character, the C code can pass around references into a single buffer, + without copying. If the \0 was missing, the C code would have to copy + things out in order to get its notion of a string. Note a size of -1 + (65535) indicates a null string and no data follow the length in this + case.</dd> +</dl> +</p> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Packet Size"><strong>Packet Size</strong></a></font></td></tr><tr><td><blockquote> +<p> +According to much of the code, the max packet +size is 8 * 1024 bytes (8K). The actual length of the packet is encoded in the +header. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Packet Headers"><strong>Packet Headers</strong></a></font></td></tr><tr><td><blockquote> +<p> +Packets sent from the server to the container begin with +<b class="code">0x1234</b>. Packets sent from the container to the server begin +with <b class="code">AB</b> (that's the ASCII code for A followed by the ASCII +code for B). After those first two bytes, there is an integer (encoded as +above) with the length of the payload. Although this might suggest that +the maximum payload could be as large as 2^16, in fact, the code sets the +maximum to be 8K. + + +<table> + <tr> + <th colspan="6">Packet Format (Server->Container)</th> + </tr> + + <tr> + <th>Byte</th> + <td>0</td> + <td>1</td> + <td>2</td> + <td>3</td> + <td>4...(n+3)</td> + </tr> + + <tr> + <th>Contents</th> + <td>0x12</td> + <td>0x34</td> + <td colspan="2">Data Length (n)</td> + <td>Data</td> + </tr> +</table> + +<table> + <tr> + <th colspan="6"><b>Packet Format (Container->Server)</b></th> + </tr> + + <tr> + <th>Byte</th> + <td>0</td> + <td>1</td> + <td>2</td> + <td>3</td> + <td>4...(n+3)</td> + </tr> + + <tr> + <th>Contents</th> + <td>A</td> + <td>B</td> + <td colspan="2">Data Length (n)</td> + <td>Data</td> + </tr> +</table> +</p> +<p> +<A NAME="prefix-codes"></A> For most packets, the first byte of the +payload encodes the type of message. The exception is for request body +packets sent from the server to the container -- they are sent with a +standard packet header (0x1234 and then length of the packet), but without +any prefix code after that (this seems like a mistake to me). +</p><p> +The web server can send the following messages to the servlet container: + +<table> + <tr> + <th>Code</th> + <th>Type of Packet</th> + <th>Meaning</th> + </tr> + <tr> + <td>2</td> + <td>Forward Request</td> + <td>Begin the request-processing cycle with the following data</td> + </tr> + <tr> + <td>7</td> + <td>Shutdown</td> + <td>The web server asks the container to shut itself down.</td> + </tr> + <tr> + <td>8</td> + <td>Ping</td> + <td>The web server asks the container to take control (secure login phase).</td> + </tr> + <tr> + <td>10</td> + <td>CPing</td> + <td>The web server asks the container to respond quickly with a CPong.</td> + </tr> + <tr> + <td>none</td> + <td>Data</td> + <td>Size (2 bytes) and corresponding body data.</td> + </tr> +</table> +</p> +<p> +To ensure some +basic security, the container will only actually do the <b class="code">Shutdown</b> if the +request comes from the same machine on which it's hosted. +</p> +<p> +The first <b class="code">Data</b> packet is send immediatly after the <b class="code">Forward Request</b> by the web server. +</p> + +<p>The servlet container can send the following types of messages to the web +server: +<table> + <tr> + <th>Code</th> + <th>Type of Packet</th> + <th>Meaning</th> + </tr> + <tr> + <td>3</td> + <td>Send Body Chunk</td> + <td>Send a chunk of the body from the servlet container to the web + server (and presumably, onto the browser). </td> + </tr> + <tr> + <td>4</td> + <td>Send Headers</td> + <td>Send the response headers from the servlet container to the web + server (and presumably, onto the browser).</td> + </tr> + <tr> + <td>5</td> + <td>End Response</td> + <td>Marks the end of the response (and thus the request-handling cycle).</td> + </tr> + <tr> + <td>6</td> + <td>Get Body Chunk</td> + <td>Get further data from the request if it hasn't all been transferred + yet.</td> + </tr> + <tr> + <td>9</td> + <td>CPong Reply</td> + <td>The reply to a CPing request</td> + </tr> +</table> +</p> +<p> +Each of the above messages has a different internal structure, detailed below. +</p> +</blockquote></td></tr></table> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Request Packet Structure"><strong>Request Packet Structure</strong></a></font></td></tr><tr><td><blockquote> + +<p> +For messages from the server to the container of type "Forward Request": +</p><p> +<div class="example"><pre> +AJP13_FORWARD_REQUEST := + prefix_code (byte) 0x02 = JK_AJP13_FORWARD_REQUEST + method (byte) + protocol (string) + req_uri (string) + remote_addr (string) + remote_host (string) + server_name (string) + server_port (integer) + is_ssl (boolean) + num_headers (integer) + request_headers *(req_header_name req_header_value) + attributes *(attribut_name attribute_value) + request_terminator (byte) OxFF +</pre></div> +</p><p> +The <b class="code">request_headers</b> have the following structure: +</p><p> +<div class="example"><pre> +req_header_name := + sc_req_header_name | (string) [see below for how this is parsed] + +sc_req_header_name := 0xA0xx (integer) + +req_header_value := (string) +</pre></div> +</p><p> + +The <b class="code">attributes</b> are optional and have the following structure: +</p><p> +<div class="example"><pre> +attribute_name := sc_a_name | (sc_a_req_attribute string) + +attribute_value := (string) + +</pre></div> +</p><p> +Not that the all-important header is "content-length', because it +determines whether or not the container looks for another packet +immediately. +</p><p> +Detailed description of the elements of Forward Request. +</p> +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="request_prefix"><strong>request_prefix</strong></a></font></td></tr><tr><td><blockquote> +<p> +For all requests, this will be 2. +See above for details on other <A HREF="#prefix-codes">prefix codes</A>. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="method"><strong>method</strong></a></font></td></tr><tr><td><blockquote> +<p> +The HTTP method, encoded as a single byte: +</p> + +<p> +<table> + <tr><th>Command Name</th><th>Code</th></tr> + <tr><td>OPTIONS</td><td>1</td></tr> + <tr><td>GET</td><td>2</td></tr> + <tr><td>HEAD</td><td>3</td></tr> + <tr><td>POST</td><td>4</td></tr> + <tr><td>PUT</td><td>5</td></tr> + <tr><td>DELETE</td><td>6</td></tr> + <tr><td>TRACE</td><td>7</td></tr> + <tr><td>PROPFIND</td><td>8</td></tr> + <tr><td>PROPPATCH</td><td>9</td></tr> + <tr><td>MKCOL</td><td>10</td></tr> + <tr><td>COPY</td><td>11</td></tr> + <tr><td>MOVE</td><td>12</td></tr> + <tr><td>LOCK</td><td>13</td></tr> + <tr><td>UNLOCK</td><td>14</td></tr> + <tr><td>ACL</td><td>15</td></tr> + <tr><td>REPORT</td><td>16</td></tr> + <tr><td>VERSION-CONTROL</td><td>17</td></tr> + <tr><td>CHECKIN</td><td>18</td></tr> + <tr><td>CHECKOUT</td><td>19</td></tr> + <tr><td>UNCHECKOUT</td><td>20</td></tr> + <tr><td>SEARCH</td><td>21</td></tr> + <tr><td>MKWORKSPACE</td><td>22</td></tr> + <tr><td>UPDATE</td><td>23</td></tr> + <tr><td>LABEL</td><td>24</td></tr> + <tr><td>MERGE</td><td>25</td></tr> + <tr><td>BASELINE_CONTROL</td><td>26</td></tr> + <tr><td>MKACTIVITY</td><td>27</td></tr> +</table> +</p> + +<p>Later version of ajp13, when used with mod_jk2, will transport +additional methods, even if they are not in this list. +</p> + +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="protocol, req_uri, remote_addr, remote_host, server_name, server_port, is_ssl"><strong>protocol, req_uri, remote_addr, remote_host, server_name, server_port, is_ssl</strong></a></font></td></tr><tr><td><blockquote> +<p> + These are all fairly self-explanatory. Each of these is required, and + will be sent for every request. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Headers"><strong>Headers</strong></a></font></td></tr><tr><td><blockquote> +<p> + The structure of <b class="code">request_headers</b> is the following: + First, the number of headers <b class="code">num_headers</b> is encoded. + Then, a series of header name <b class="code">req_header_name</b> / value + <b class="code">req_header_value</b> pairs follows. + Common header names are encoded as integers, + to save space. If the header name is not in the list of basic headers, + it is encoded normally (as a string, with prefixed length). The list of + common headers <b class="code">sc_req_header_name</b>and their codes + is as follows (all are case-sensitive): +</p><p> +<table> + <tr><th>Name</th><th>Code value</th><th>Code name</th></tr> + <tr><td>accept</td><td>0xA001</td><td>SC_REQ_ACCEPT</td></tr> + <tr><td>accept-charset</td><td>0xA002</td><td>SC_REQ_ACCEPT_CHARSET</td></tr> + <tr><td>accept-encoding</td><td>0xA003</td><td>SC_REQ_ACCEPT_ENCODING</td></tr> + <tr><td>accept-language</td><td>0xA004</td><td>SC_REQ_ACCEPT_LANGUAGE</td></tr> + <tr><td>authorization</td><td>0xA005</td><td>SC_REQ_AUTHORIZATION</td></tr> + <tr><td>connection</td><td>0xA006</td><td>SC_REQ_CONNECTION</td></tr> + <tr><td>content-type</td><td>0xA007</td><td>SC_REQ_CONTENT_TYPE</td></tr> + <tr><td>content-length</td><td>0xA008</td><td>SC_REQ_CONTENT_LENGTH</td></tr> + <tr><td>cookie</td><td>0xA009</td><td>SC_REQ_COOKIE</td></tr> + <tr><td>cookie2</td><td>0xA00A</td><td>SC_REQ_COOKIE2</td></tr> + <tr><td>host</td><td>0xA00B</td><td>SC_REQ_HOST</td></tr> + <tr><td>pragma</td><td>0xA00C</td><td>SC_REQ_PRAGMA</td></tr> + <tr><td>referer</td><td>0xA00D</td><td>SC_REQ_REFERER</td></tr> + <tr><td>user-agent</td><td>0xA00E</td><td>SC_REQ_USER_AGENT</td></tr> +</table> +</p><p> + The Java code that reads this grabs the first two-byte integer and if + it sees an <b class="code">'0xA0'</b> in the most significant + byte, it uses the integer in the second byte as an index into an array of + header names. If the first byte is not '0xA0', it assumes that the + two-byte integer is the length of a string, which is then read in. +</p><p> + This works on the assumption that no header names will have length + greater than 0x9999 (==0xA000 - 1), which is perfectly reasonable, though + somewhat arbitrary. (If you, like me, started to think about the cookie + spec here, and about how long headers can get, fear not -- this limit is + on header <b>names</b> not header <b>values</b>. It seems unlikely that + unmanageably huge header names will be showing up in the HTTP spec any time + soon). +</p><p> + <b>Note:</b> The <b class="code">content-length</b> header is extremely + important. If it is present and non-zero, the container assumes that + the request has a body (a POST request, for example), and immediately + reads a separate packet off the input stream to get that body. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Attributes"><strong>Attributes</strong></a></font></td></tr><tr><td><blockquote> +<p> + + The attributes prefixed with a <b class="code">?</b> + (e.g. <b class="code">?context</b>) are all optional. For each, there is a + single byte code to indicate the type of attribute, and then a string to + give its value. They can be sent in any order (thogh the C code always + sends them in the order listed below). A special terminating code is + sent to signal the end of the list of optional attributes. The list of + byte codes is: +</p><p> + +<table> + <tr><th>Information</th><th>Code Value</th><th>Note</th></tr> + <tr><td>?context</td><td>0x01</td><td>Not currently implemented</td></tr> + <tr><td>?servlet_path</td><td>0x02</td><td>Not currently implemented</td></tr> + <tr><td>?remote_user</td><td>0x03</td><td></td></tr> + <tr><td>?auth_type</td><td>0x04</td><td></td></tr> + <tr><td>?query_string</td><td>0x05</td><td></td></tr> + <tr><td>?route</td><td>0x06</td><td></td></tr> + <tr><td>?ssl_cert</td><td>0x07</td><td></td></tr> + <tr><td>?ssl_cipher</td><td>0x08</td><td></td></tr> + <tr><td>?ssl_session</td><td>0x09</td><td></td></tr> + <tr><td>?req_attribute</td><td>0x0A</td><td>Name (the name of the attribut follows)</td></tr> + <tr><td>?ssl_key_size</td><td>0x0B</td><td></td></tr> + <tr><td>?secret</td><td>0x0C</td><td></td></tr> + <tr><td>?stored_method</td><td>0x0D</td><td></td></tr> + <tr><td>are_done</td><td>0xFF</td><td>request_terminator</td></tr> +</table> + +</p><p> + + The <b class="code">context</b> and <b class="code">servlet_path</b> are not currently + set by the C code, and most of the Java code completely ignores whatever + is sent over for those fields (and some of it will actually break if a + string is sent along after one of those codes). I don't know if this is + a bug or an unimplemented feature or just vestigial code, but it's + missing from both sides of the connection. +</p><p> + The <b class="code">remote_user</b> and <b class="code">auth_type</b> presumably refer + to HTTP-level authentication, and communicate the remote user's username + and the type of authentication used to establish their identity (e.g. Basic, + Digest). I'm not clear on why the password isn't also sent, but I don't + know HTTP authentication inside and out. +</p><p> + The <b class="code">query_string</b>, <b class="code">ssl_cert</b>, + <b class="code">ssl_cipher</b>, and <b class="code">ssl_session</b> refer to the + corresponding pieces of HTTP and HTTPS. +</p><p> + The <b class="code">route</b>, as I understand it, is used to support sticky + sessions -- associating a user's sesson with a particular Tomcat instance + in the presence of multiple, load-balancing servers. I don't know the + details. +</p><p> + Beyond this list of basic attributes, any number of other attributes can + be sent via the <b class="code">req_attribute</b> code (0x0A). A pair of strings + to represent the attribute name and value are sent immediately after each + instance of that code. Environment values are passed in via this method. +</p><p> + Finally, after all the attributes have been sent, the attribute terminator, + 0xFF, is sent. This signals both the end of the list of attributes and + also then end of the Request Packet. +</p> +</blockquote></td></tr></table> + +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Response Packet Structure"><strong>Response Packet Structure</strong></a></font></td></tr><tr><td><blockquote> + +<p> +For messages which the container can send back to the server. + +<div class="example"><pre> +AJP13_SEND_BODY_CHUNK := + prefix_code 3 + chunk_length (integer) + chunk *(byte) + + +AJP13_SEND_HEADERS := + prefix_code 4 + http_status_code (integer) + http_status_msg (string) + num_headers (integer) + response_headers *(res_header_name header_value) + +res_header_name := + sc_res_header_name | (string) [see below for how this is parsed] + +sc_res_header_name := 0xA0 (byte) + +header_value := (string) + +AJP13_END_RESPONSE := + prefix_code 5 + reuse (boolean) + + +AJP13_GET_BODY_CHUNK := + prefix_code 6 + requested_length (integer) +</pre></div> + +</p> +<p> +Details: +</p> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Send Body Chunk"><strong>Send Body Chunk</strong></a></font></td></tr><tr><td><blockquote> +<p> + The chunk is basically binary data, and is sent directly back to the browser. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Send Headers"><strong>Send Headers</strong></a></font></td></tr><tr><td><blockquote> +<p> + The status code and message are the usual HTTP things (e.g. "200" and "OK"). + The response header names are encoded the same way the request header names are. + See <A HREF="#header_encoding">above</A> for details about how the the + codes are distinguished from the strings. The codes for common headers are: +</p> + +<p> +<table> + <tr><th>Name</th><th>Code value</th></tr> + <tr><td>Content-Type</td><td>0xA001</td></tr> + <tr><td>Content-Language</td><td>0xA002</td></tr> + <tr><td>Content-Length</td><td>0xA003</td></tr> + <tr><td>Date</td><td>0xA004</td></tr> + <tr><td>Last-Modified</td><td>0xA005</td></tr> + <tr><td>Location</td><td>0xA006</td></tr> + <tr><td>Set-Cookie</td><td>0xA007</td></tr> + <tr><td>Set-Cookie2</td><td>0xA008</td></tr> + <tr><td>Servlet-Engine</td><td>0xA009</td></tr> + <tr><td>Status</td><td>0xA00A</td></tr> + <tr><td>WWW-Authenticate</td><td>0xA00B</td></tr> +</table> + +</p> + +<p> + After the code or the string header name, the header value is immediately + encoded. +</p> + +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="End Response"><strong>End Response</strong></a></font></td></tr><tr><td><blockquote> +<p> + Signals the end of this request-handling cycle. If the + <b class="code">reuse</b> flag is true (==1), this TCP connection can now be used to + handle new incoming requests. If <b class="code">reuse</b> is false (anything + other than 1 in the actual C code), the connection should be closed. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Get Body Chunk"><strong>Get Body Chunk</strong></a></font></td></tr><tr><td><blockquote> +<p> + The container asks for more data from the request (If the body was + too large to fit in the first packet sent over or when the request is + chuncked). + The server will send a body packet back with an amount of data which is + the minimum of the <b class="code">request_length</b>, + the maximum send body size (8186 (8 Kbytes - 6)), and the + number of bytes actually left to send from the request body. +<br> + If there is no more data in the body (i.e. the servlet container is + trying to read past the end of the body), the server will send back an + "empty" packet, which is a body packet with a payload length of 0. + (0x12,0x34,0x00,0x00) +</p> +</blockquote></td></tr></table> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Questions I Have"><strong>Questions I Have</strong></a></font></td></tr><tr><td><blockquote> + +<p> What happens if the request headers > max packet size? There is no +provision to send a second packet of request headers in case there are more +than 8K (I think this is correctly handled for response headers, though I'm +not certain). I don't know if there is a way to get more than 8K worth of +data into that initial set of request headers, but I'll bet there is +(combine long cookies with long ssl information and a lot of environment +variables, and you should hit 8K easily). I think the connector would just +fail before trying to send any headers in this case, but I'm not certain.</p> + +<p> What about authentication? There doesn't seem to be any authentication +of the connection between the web server and the container. This strikes +me as potentially dangerous.</p> + +</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em> + Copyright © 1999-2011, Apache Software Foundation + </em></font></div></td></tr></table></body></html>
\ No newline at end of file diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/ajpv13ext.html b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/ajpv13ext.html new file mode 100644 index 00000000..187aab19 --- /dev/null +++ b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/ajpv13ext.html @@ -0,0 +1,654 @@ +<html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>The Apache Tomcat Connector - AJP Protocol Reference - AJPv13 extensions Proposal</title><meta name="author" value="Henri Gomez"><meta name="email" value="hgomez@apache.org"><link href="../style.css" type="text/css" rel="stylesheet"></head><body bgcolor="#ffffff" text="#000000" link="#525D76" alink="#525D76" vlink="#525D76"><table border="0" width="100%" cellspacing="4"><!--PAGE HEADER--><tr><td colspan="2"><!--TOMCAT LOGO--><a href="http://tomcat.apache.org/"><img src="../images/tomcat.gif" align="left" alt="Apache Tomcat" border="0"></a><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="http://www.apache.org/images/asf-logo.gif" align="right" alt="Apache Logo" border="0"></a></td></tr><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><tr><!--LEFT SIDE NAVIGATION--><td width="20%" valign="top" nowrap="true"><p><strong>Links</strong></p><ul><li><a href="../index.html">Docs Home</a></li></ul><p><strong>Reference Guide</strong></p><ul><li><a href="../reference/workers.html">workers.properties</a></li><li><a href="../reference/uriworkermap.html">uriworkermap.properties</a></li><li><a href="../reference/status.html">Status Worker</a></li><li><a href="../reference/apache.html">Apache HTTP Server</a></li><li><a href="../reference/iis.html">IIS</a></li></ul><p><strong>Generic HowTo</strong></p><ul><li><a href="../generic_howto/quick.html">For the impatient</a></li><li><a href="../generic_howto/workers.html">All about workers</a></li><li><a href="../generic_howto/timeouts.html">Timeouts</a></li><li><a href="../generic_howto/loadbalancers.html">Load Balancing</a></li><li><a href="../generic_howto/proxy.html">Reverse Proxy</a></li></ul><p><strong>Webserver HowTo</strong></p><ul><li><a href="../webserver_howto/apache.html">Apache HTTP Server</a></li><li><a href="../webserver_howto/iis.html">IIS</a></li><li><a href="../webserver_howto/nes.html">Netscape/SunOne/Sun</a></li></ul><p><strong>AJP Protocol Reference</strong></p><ul><li><a href="../ajp/ajpv13a.html">AJPv13</a></li><li><a href="../ajp/ajpv13ext.html">AJPv13 Extension Proposal</a></li></ul><p><strong>Miscellaneous Documentation</strong></p><ul><li><a href="../miscellaneous/faq.html">Frequently asked questions</a></li><li><a href="../miscellaneous/changelog.html">Changelog</a></li><li><a href="http://issues.apache.org/bugzilla/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=&product=Tomcat+Connectors&long_desc_type=substring&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&keywords_type=allwords&keywords=&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&emailassigned_to1=1&emailtype1=substring&email1=&emailassigned_to2=1&emailreporter2=1&emailcc2=1&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0=">Current Tomcat Connectors bugs</a></li><li><a href="../miscellaneous/doccontrib.html">Contribute documentation</a></li><li><a href="../miscellaneous/jkstatustasks.html">JK Status Ant Tasks</a></li><li><a href="../miscellaneous/reporttools.html">Reporting Tools</a></li><li><a href="http://tomcat.apache.org/connectors-doc-archive/jk2/index.html">Old JK/JK2 documentation</a></li></ul><p><strong>News</strong></p><ul><li><a href="../news/20110701.html">2011</a></li><li><a href="../news/20100101.html">2010</a></li><li><a href="../news/20090301.html">2009</a></li><li><a href="../news/20081001.html">2008</a></li><li><a href="../news/20070301.html">2007</a></li><li><a href="../news/20060101.html">2006</a></li><li><a href="../news/20050101.html">2005</a></li><li><a href="../news/20041100.html">2004</a></li></ul></td><!--RIGHT SIDE MAIN BODY--><td width="80%" valign="top" align="left"><table border="0" width="100%" cellspacing="4"><tr><td align="left" valign="top"><h1>The Apache Tomcat Connector - AJP Protocol Reference</h1><h2>AJPv13 extensions Proposal</h2></td><td align="right" valign="top" nowrap="true"><small><a href="printer/ajpv13ext.html"><img src="../images/printer.gif" border="0" alt="Printer Friendly Version"><br>print-friendly<br>version + </a></small></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> +<p> +This document is a proposal of evolution of the current +Apache JServ Protocol version 1.3, also known as ajp13. +I'll not cover here the full protocol but only the add-on from ajp13. + +This nth pass include comments from the tomcat-dev list and +misses discovered during developpment. +</p> +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Missing features in AJP13"><strong>Missing features in AJP13</strong></a></font></td></tr><tr><td><blockquote> +<p> +ajp13 is a good protocol to link a servlet engine like tomcat to a web server like Apache: + +<ul> +<li> +use persistants connections to avoid reconnect time at each request +</li> +<li> +encode many http commands to reduce stream size +</li> +<li> +send to servlet engine many info from web server (like SSL certs) +</li> +</ul> +<p> +But ajp13 lacks support for : +</p> +<ul> +<li> + security between web server and servlet engine. + Anybody can connect to an ajp13 port (no login mecanism used) + You could connect, for example with telnet, and keep the remote thread + up by not sending any data (no timeout in connection) +</li> +<li> + context information passed from servlet engine to web server. + Part of the configuration of JK, the web server connector, is to + indicate to the web server which URI to handle. + The mod_jk JkMount directive, told to web server which URI must be + forwarded to servlet engine. + A servlet engine allready knows which URI it handle and TC 3.3 is + allready capable to generate a config file for JK from the list + of available contexts. +</li> +<li> + state update of contexts from servlet engine to web server. + Big site with farm of Tomcat, like ISP and virtuals hosters, + may need to stop a context for admin purposes. In that case the front + web server must know that the context is currently down, to eventually + relay the request to another Tomcat +</li> +<li> + verify state of connection before sending request. + Actually JK send the request to the servlet engine and next wait + for the answer. But one of the beauty of the socket API, is you that + you could write() to a closed connection without any error reporting, + but a read() to a closed connection return you the error code. +</li> +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Proposed add-ons to AJP13"><strong>Proposed add-ons to AJP13</strong></a></font></td></tr><tr><td><blockquote> +<p> +Let's descrive here the features and add-on that could be added to AJP13. +Since this document is a proposal, a reasonable level of chaos must be expected at first. +Be sure that discussion on tomcat list will help clarify points, add +features but the current list seems to be a 'minimun vital' + +<ul> + +<li> +Advanced login features at connect time +</li> + +<li> +Basic authorisation system, where a shared secret key is +present in web server and servlet engine. +</li> + +<li> +Basic protocol negociation, just to be sure that if functionnalities are added +to AJP13 in the future, current implementations will still works. +</li> + +<li> +Clean handling of 'Unknown packets' +</li> + +<li> +Extended env vars passed from web-server to servlet engine. +</li> + +<li> +Add extra SSL informations needed by Servlet 2.3 API (like SSL_KEY_SIZE) +</li> + +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Advanced login"><strong>Advanced login</strong></a></font></td></tr><tr><td><blockquote> +<p> + +<ol> +<li> +WEB-SERVER send LOGIN INIT CMD + NEGOCIATION DATA + WEB SERVER INFO +</li> +<li> + TOMCAT respond with LOGIN SEED CMD + RANDOM DATA +</li> +<li> + WEB-SERVER calculted the MD5 of RANDOM DATA+SECRET DATA +</li> +<li> + WEB-SERVER send LOGIN COMP CMD + MD5 (SECRET DATA + RANDOM DATA) +</li> +<li> + TOMCAT respond with LOGIN STATUS CMD + NEGOCIED DATA + SERVLET ENGINE INFO +</li> +</ol> + +To prevent DOS attack, the servlet engine will wait +the LOGIN CMD only 15/30 seconds and reports the +timeout exception for admins investigation. + +The login command will contains basic protocol +negociation information like compressing ability, +crypto, context info (at start up), context update at +run-time (up/down), level of SSL env vars, AJP protocol +level supported (level1/level2/level3...) + +The Web server info will contain web server info and +connector name (ie Apache 1.3.26 + mod_ssl 2.8.8 + mod_jk 1.2.1 + mod_perl 1.25). + +The servlet engine will mask the negociation mask with it's own +mask (what it can do) and return it when loggin is accepted. + +This will help having a basic AJP13 implementation (level 1) +on a web-server working with a more advanced protocol handler on +the servlet engine side or vice-versa. + +AJP13 was designed to be small and fast and so many +SSL informations present in the web-server are not +forwarded to the servlet engine. + +We add here four negociations flags to provide more +informations on client SSL data (certs), server SSL datas, +crypto used, and misc datas (timeout...). +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Messages Stream"><strong>Messages Stream</strong></a></font></td></tr><tr><td><blockquote> +<p> +<div class="example"><pre> ++----------------+------------------+-----------------+ +| LOGIN INIT CMD | NEGOCIATION DATA | WEB SERVER INFO | ++----------------+------------------+-----------------+ + ++----------------+----------------+ +| LOGIN SEED CMD | MD5 of entropy | ++----------------+----------------+ + ++----------------+----------------------------+ +| LOGIN COMP CMD | MD5 of RANDOM + SECRET KEY | ++----------------+----------------------------+ + ++-----------+---------------+---------------------+ +| LOGOK CMD | NEGOCIED DATA | SERVLET ENGINE INFO | ++-----------+---------------+---------------------+ + ++------------+--------------+ +| LOGNOK CMD | FAILURE CODE | ++------------+--------------+ +</pre></div> + +<ul> +<li> +LOGIN INIT CMD, LOGIN SEED CMD, LOGIN COMP CMD, LOGOK CMD, LOGNOK CMD are 1 byte long. +</li> +<li> +MD5, MD5 of RANDOM + SECRET KEY are 32 chars long. +</li> +<li> +NEGOCIATION DATA, NEGOCIED DATA, FAILURE CODE are 32 bits long. +</li> +<li> +WEB SERVER INFO, SERVLET ENGINE INFO are CString. +</li> +</ul> + +The secret key will be set by a new propertie in +workers.properties : secretkey +<div class="example"><pre> +worker.ajp13.port=8009 +worker.ajp13.host=localhost +worker.ajp13.type=ajp13 +worker.ajp13.secretkey=myverysecretkey +</pre></div> +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Shutdown feature"><strong>Shutdown feature</strong></a></font></td></tr><tr><td><blockquote> +<p> +AJP13 miss a functionnality of AJP12, which is shutdown command. +A logout will tell servlet engine to shutdown itself. +<div class="example"><pre> ++--------------+----------------------------+ +| SHUTDOWN CMD | MD5 of RANDOM + SECRET KEY | ++--------------+----------------------------+ + ++------------+ +| SHUTOK CMD | ++------------+ + ++-------------+--------------+ +| SHUTNOK CMD | FAILURE CODE | ++-------------+--------------+ +</pre></div> + +<ul> +<li> +SHUTDOWN CMD, SHUTOK CMD, SHUTNOK CMD are 1 byte long. +</li> +<li> +MD5 of RANDOM + SECRET KEY are 32 chars long. +</li> +<li> +FAILURE CODE is 32 bits long. +</li> +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Extended Env Vars feature"><strong>Extended Env Vars feature</strong></a></font></td></tr><tr><td><blockquote> +<p> +NOTA: + +While working on AJP13 in JK, I really discovered "JkEnvVar". +The following "Extended Env Vars feature" description may not +be implemented in extended AJP13 since allready available in original +implementation. + +DESC: + +Many users will want to see some of their web-server env vars +passed to their servlet engine. + +To reduce the network traffic, the web-servlet will send a +table to describing the external vars in a shorter fashion. + +We'll use there a functionnality allready present in AJP13, +attributes list : + +In the AJP13, we've got : + +<div class="example"><pre> +AJP13_FORWARD_REQUEST := + prefix_code 2 + method (byte) + protocol (string) + req_uri (string) + remote_addr (string) + remote_host (string) + server_name (string) + server_port (integer) + is_ssl (boolean) + num_headers (integer) + request_headers *(req_header_name req_header_value) + + ?context (byte string) + ?servlet_path (byte string) + ?remote_user (byte string) + ?auth_type (byte string) + ?query_string (byte string) + ?route (byte string) + ?ssl_cert (byte string) + ?ssl_cipher (byte string) + ?ssl_session (byte string) + + ?attributes *(attribute_name attribute_value) + request_terminator (byte) +</pre></div> + +Using short 'web server attribute name' will reduce the +network traffic. + +<div class="example"><pre> ++-------------------+---------------------------+-------------------------------+----+ +| EXTENDED VARS CMD | WEB SERVER ATTRIBUTE NAME | SERVLET ENGINE ATTRIBUTE NAME | ES | ++-------------------+---------------------------+-------------------------------+----+ +</pre></div> + +ie : + +<div class="example"><pre> +JkExtVars S1 SSL_CLIENT_V_START javax.servlet.request.ssl_start_cert_date +JkExtVars S2 SSL_CLIENT_V_END javax.servlet.request.ssl_end_cert_date +JkExtVars S3 SSL_SESSION_ID javax.servlet.request.ssl_session_id + + ++-------------------+----+-------------------------------------------+ +| EXTENDED VARS CMD | S1 | javax.servlet.request.ssl_start_cert_date | ++-------------------+----+-------------------------------------------+ ++----+-----------------------------------------+ +| S2 | javax.servlet.request.ssl_end_cert_date | ++----+-----------------------------------------+ ++----+-----------------------------------------+ +| S3 | javax.servlet.request.ssl_end_cert_date | ++----+-----------------------------------------+ +</pre></div> + +During transmission in extended AJP13 we'll see attributes name +containing S1, S2, S3 and attributes values of +2001/01/03, 2002/01/03, 0123AFE56. + +This example showed the use of extended SSL vars but +any 'personnal' web-server vars like custom authentification +vars could be reused in the servlet engine. +The cost will be only some more bytes in the AJP traffic. + +<ul> +<li> +EXTENDED VARS CMD is 1 byte long. +</li> +<li> +WEB SERVER ATTRIBUTE NAME, SERVLET ENGINE ATTRIBUTE NAME are CString. +</li> +<li> +ES is an empty CString. +</li> +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Context informations forwarding for Servlet engine to Web Server"><strong>Context informations forwarding for Servlet engine to Web Server</strong></a></font></td></tr><tr><td><blockquote> +<p> +Just after the LOGON PHASE, the web server will ask for the list of contexts +and URLs/URIs handled by the servlet engine. +It will ease installation in many sites, reduce questions about configuration +on tomcat-user list, and be ready for servlet API 2.3. + +This mode will be activated by a new directive JkAutoMount + +ie: JkAutoMount examples myworker1 /examples/ + +If we want to get ALL the contexts handled by the servlet engine, willcard +could be used : + +ie: JkAutoMount * myworker1 * + +A servlet engine could have many contexts, /examples, /admin, /test. +We may want to use only some contexts for a given worker. It was +done previously, in apache HTTP server for example, by setting by +hand the JkMount accordingly in each [virtual] area of Apache. + +If you web-server support virtual hosting, we'll forward also that +information to servlet engine which will only return contexts for +that virtual host. +In that case the servlet engine will only return the URL/URI matching +these particular virtual server (defined in server.xml). +This feature will help ISP and big sites which mutualize large farm +of Tomcat in load-balancing configuration. + +<div class="example"><pre> ++-----------------+-------------------+----------+----------+----+ +| CONTEXT QRY CMD | VIRTUAL HOST NAME | CONTEXTA | CONTEXTB | ES | ++-----------------+-------------------+----------+----------+----+ + ++------------------+-------------------+----------+-------------------+----------+---------------+----+ +| CONTEXT INFO CMD | VIRTUAL HOST NAME | CONTEXTA | URL1 URL2 URL3 ES | CONTEXTB | URL1 URL2 ... | ES | ++------------------+-------------------+----------+-------------------+----------+---------------+----+ +</pre></div> + +We'll discover via context-query, the list of URL/MIMES handled by the remove servlet engine +for a list of contextes. +In wildcard mode, CONTEXTA will contains just '*'. + +<ul> +<li> +CONTEXT QRY CMD and CONTEXT INFO CMD are 1 byte long. +</li> +<li> +VIRTUAL HOST NAME is a CString, ie an array of chars terminated by a null byte (/0). +</li> +<li> +An empty string is just a null byte (/0). +</li> +<li> +ES is an empty CString. Indicate end of URI/URLs or end of CONTEXTs. +</li> +</ul> + +NB:<br> +When VirtualMode is not to be used, the VIRTUAL HOST NAME is '*'. +In that case the servlet engine will send all contexts handled. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Context informations updates from Servlet engine to Web Server"><strong>Context informations updates from Servlet engine to Web Server</strong></a></font></td></tr><tr><td><blockquote> +<p> +Context update are messages caming from the servlet engine each time a context +is desactivated/reactivated. The update will be in use when the directive JkUpdateMount. +This directive will set the AJP13_CONTEXT_UPDATE_NEG flag. + +ie: JkUpdateMount myworker1 + +<div class="example"><pre> ++--------------------+-------------------+----------+--------+----------+--------+----+ +| CONTEXT UPDATE CMD | VIRTUAL HOST NAME | CONTEXTA | STATUS | CONTEXTB | STATUS | ES | ++--------------------+-------------------+----------+--------+----------+--------+----+ +</pre></div> + +<ul> +<li> +CONTEXT UPDATE CMD, STATUS are 1 byte long. +</li> +<li> +VIRTUAL HOST NAME, CONTEXTS are CString. +</li> +<li> +ES is an empty CString. Indicate end of CONTEXTs. +</li> +</ul> + +NB:<br> +When VirtualMode is not in use, the VIRTUAL HOST NAME is '*'. +STATUS is one byte indicating if context is UP/DOWN/INVALID +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Context status query to Servlet engine"><strong>Context status query to Servlet engine</strong></a></font></td></tr><tr><td><blockquote> +<p> +This query will be used by the web-server to determine if a given +contexts are UP, DOWN or INVALID (and should be removed). + +<div class="example"><pre> ++-------------------+--------------------+----------+----------+----+ +| CONTEXT STATE CMD | VIRTUAL HOST NAME | CONTEXTA | CONTEXTB | ES | ++-------------------+--------------------+----------+----------+----+ + ++-------------------------+-------------------+----------+--------+----------+--------+----+ +| CONTEXT STATE REPLY CMD | VIRTUAL HOST NAME | CONTEXTA | STATUS | CONTEXTB | STATUS | ES | ++-------------------------+-------------------+----------+-------------------+--------+----+ +</pre></div> + +<ul> +<li> +CONTEXT STATE CMD, CONTEXT STATE REPLY CMD, STATUS are 1 byte long. +</li> +<li> +VIRTUAL HOST NAME, CONTEXTs are CString +</li> +<li> +ES is an empty CString +</li> +</ul> + +NB:<br> +When VirtualMode is not in use, the VIRTUAL HOST NAME is an empty string. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Handling of unknown packets"><strong>Handling of unknown packets</strong></a></font></td></tr><tr><td><blockquote> +<p> +Sometimes even with a well negocied protocol, we may be in a situation +where one end (web server or servlet engine), will receive a message it +couldn't understand. In that case the receiver will send an +'UNKNOW PACKET CMD' with attached the unhandled message. + +<div class="example"><pre> ++--------------------+------------------------+-------------------+ +| UNKNOWN PACKET CMD | UNHANDLED MESSAGE SIZE | UNHANDLED MESSAGE | ++--------------------+------------------------+-------------------+ +</pre></div> + +Depending on the message, the sender will report an error and if +possible will try to forward the message to another endpoint. + +<ul> +<li> +UNKNOWN PACKET CMD is 1 byte long. +</li> +<li> +UNHANDLED MESSAGE SIZE is 16bits long. +</li> +<li> +UNHANDLED MESSAGE is an array of byte (length is contained in UNHANDLED MESSAGE SIZE) +</li> +</ul> + +NB:<br> +added UNHANDLED MESSAGE SIZE (development) +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Verification of connection before sending request"><strong>Verification of connection before sending request</strong></a></font></td></tr><tr><td><blockquote> +<p> +NOTA: This fonctionality may never be used, since it may slow up the normal process +since requiring on the web-server side an extra IO (read) before forwarding +the request..... + +One of the beauty of socket APIs, is that you could write on a half closed socket. +When servlet engine close the socket, the web server will discover it only at the +next read() to the socket. +Basically, in the AJP13 protocol, the web server send the HTTP HEADER and HTTP BODY +(POST by chunk of 8K) to the servlet engine and then try to receive the reply. +If the connection was broken the web server will learn it only at receive time. + +We could use a buffering scheme but what happen when you use the servlet engine +for upload operations with more than 8ko of datas ? + +The hack in the AJP13 protocol is to add some bytes to read after the end of the +service : + +<div class="example"><pre> +EXAMPLE OF DISCUSSION BETWEEN WEB SERVER AND SERVLET ENGINE + +AJP HTTP-HEADER (+ HTTP-POST) (WEB->SERVLET) + +AJP HTTP-REPLY (SERVLET->WEB) + +AJP END OF DISCUSSION (SERVLET->WEB) + +---> AJP STATUS (SERVLET->WEB AJP13) +</pre></div> + +The AJP STATUS will not be read by the servlet engine at the end of +the request/response #N but at the begining of the next session. + +More at that time the web server could also use OS dependants functions +(or better APR functions) to determine if there is also more data +to read. And that datas could be CONTEXT Updates. + +This will avoid the web server sending a request to a +desactivated context. In that case, if the load-balancing is used, +it will search for another servlet engine to handle the request. + +And that feature will help ISP and big sites with farm of tomcat, +to updates their servlet engine without any service interruption. + +<div class="example"><pre> ++------------+-------------+ +| STATUS CMD | STATUS DATA | ++------------+-------------+ +</pre></div> + +<ul> +<li> +STATUS CMD and STATUS DATA are one byte long. +</li> +</ul> +</p> +</blockquote></td></tr></table> + +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Conclusion"><strong>Conclusion</strong></a></font></td></tr><tr><td><blockquote> +<p> +The goal of the extended AJP13 protocol is to overcome some of the original AJP13 limitation. +An easier configuration, a better support for large site and farm of Tomcat, +a simple authentification system and provision for protocol updates. + +Using the stable ajp13 implementation in JK (native) and in servlet +engine (java), it's a reasonable evolution of the well known ajp13. +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Commands and IDs in extended AJP13 Index"><strong>Commands and IDs in extended AJP13 Index</strong></a></font></td></tr><tr><td><blockquote> +<p> +Index of Commands and ID to be added in AJP13 Protocol +</p> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Commands IDs"><strong>Commands IDs</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Command Name</th><th>Command Number</th></tr> + <tr><td>AJP13_LOGINIT_CMD</td><td>0x10</td></tr> + <tr><td>AJP13_LOGSEED_CMD</td><td>0x11</td></tr> + <tr><td>AJP13_LOGCOMP_CMD</td><td>0x12</td></tr> + <tr><td>AJP13_LOGOK_CMD</td><td>0x13</td></tr> + <tr><td>AJP13_LOGNOK_CMD</td><td>0x14</td></tr> + <tr><td>AJP13_CONTEXT_QRY_CMD</td><td>0x15</td></tr> + <tr><td>AJP13_CONTEXT_INFO_CMD</td><td>0x16</td></tr> + <tr><td>AJP13_CONTEXT_UPDATE_CMD</td><td>0x17</td></tr> + <tr><td>AJP13_STATUS_CMD</td><td>0x18</td></tr> + <tr><td>AJP13_SHUTDOWN_CMD</td><td>0x19</td></tr> + <tr><td>AJP13_SHUTOK_CMD</td><td>0x1A</td></tr> + <tr><td>AJP13_SHUTNOK_CMD</td><td>0x1B</td></tr> + <tr><td>AJP13_CONTEXT_STATE_CMD</td><td>0x1C</td></tr> + <tr><td>AJP13_CONTEXT_STATE_REP_CMD</td><td>0x1D</td></tr> + <tr><td>AJP13_UNKNOW_PACKET_CMD</td><td>0x1E</td></tr> +</table> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Negociations Flags"><strong>Negociations Flags</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Command Name</th><th>Number</th><th>Description</th></tr> + <tr><td>AJP13_CONTEXT_INFO_NEG</td><td>0x80000000</td><td>web-server want context info after login</td></tr> + <tr><td>AJP13_CONTEXT_UPDATE_NEG</td><td>0x40000000</td><td>web-server want context updates</td></tr> + <tr><td>AJP13_GZIP_STREAM_NEG</td><td>0x20000000</td><td>web-server want compressed stream</td></tr> + <tr><td>AJP13_DES56_STREAM_NEG</td><td>0x10000000</td><td>web-server want crypted DES56 stream with secret key</td></tr> + <tr><td>AJP13_SSL_VSERVER_NEG</td><td>0x08000000</td><td>Extended info on server SSL vars</td></tr> + <tr><td>AJP13_SSL_VCLIENT_NEG</td><td>0x04000000</td><td>Extended info on client SSL vars</td></tr> + <tr><td>AJP13_SSL_VCRYPTO_NEG</td><td>0x02000000</td><td>Extended info on crypto SSL vars</td></tr> + <tr><td>AJP13_SSL_VMISC_NEG</td><td>0x01000000</td><td>Extended info on misc SSL vars</td></tr> +</table> + +<br> + +<table> + <tr><th>Negociation ID</th><th>Number</th><th>Description</th></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJPXX_NEG</td><td>0x00FF0000</td><td>mask of protocol supported</td></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJP13L1_NEG</td><td>0x00010000</td><td>communication could use AJP13 Level 1</td></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJP13L2_NEG</td><td>0x00020000</td><td>communication could use AJP13 Level 2</td></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJP13L3_NEG</td><td>0x00040000</td><td>communication could use AJP13 Level 3</td></tr> +</table> + +<br> +All others flags must be set to 0 since they are reserved for future use. + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Failure IDs"><strong>Failure IDs</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Failure Id</th><th>Number</th></tr> + <tr><td>AJP13_BAD_KEY_ERR</td><td>0xFFFFFFFF</td></tr> + <tr><td>AJP13_ENGINE_DOWN_ERR</td><td>0xFFFFFFFE</td></tr> + <tr><td>AJP13_RETRY_LATER_ERR</td><td>0xFFFFFFFD</td></tr> + <tr><td>AJP13_SHUT_AUTHOR_FAILED_ERR</td><td>0xFFFFFFFC</td></tr> +</table> +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Status"><strong>Status</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Failure Id</th><th>Number</th></tr> + <tr><td>AJP13_CONTEXT_DOWN</td><td>0x01</td></tr> + <tr><td>AJP13_CONTEXT_UP</td><td>0x02</td></tr> + <tr><td>AJP13_CONTEXT_OK</td><td>0x03</td></tr> +</table> +</p> +</blockquote></td></tr></table> + +</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em> + Copyright © 1999-2011, Apache Software Foundation + </em></font></div></td></tr></table></body></html>
\ No newline at end of file diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/printer/ajpv13a.html b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/printer/ajpv13a.html new file mode 100644 index 00000000..53cf10a9 --- /dev/null +++ b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/printer/ajpv13a.html @@ -0,0 +1,653 @@ +<html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>The Apache Tomcat Connector - AJP Protocol Reference - AJPv13</title><meta name="author" value="danmil@shore.net"><meta name="email" value="danmil@shore.net"><meta name="author" value="Jean-Frederic Clere"><meta name="email" value="jfrederic.clere@fujitsu-siemens.com"><link href="../../style.css" type="text/css" rel="stylesheet"></head><body bgcolor="#ffffff" text="#000000" link="#525D76" alink="#525D76" vlink="#525D76"><table border="0" width="100%" cellspacing="4"><!--PAGE HEADER--><tr><td colspan="2"><!--TOMCAT LOGO--><a href="http://tomcat.apache.org/"><img src="../../images/tomcat.gif" align="left" alt="Apache Tomcat" border="0"></a><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="http://www.apache.org/images/asf-logo.gif" align="right" alt="Apache Logo" border="0"></a></td></tr><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><tr><!--RIGHT SIDE MAIN BODY--><td width="80%" valign="top" align="left"><table border="0" width="100%" cellspacing="4"><tr><td align="left" valign="top"><h1>The Apache Tomcat Connector - AJP Protocol Reference</h1><h2>AJPv13</h2></td><td align="right" valign="top" nowrap="true"><img src="../../images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Intro"><strong>Intro</strong></a></font></td></tr><tr><td><blockquote> + +<p> +The original document was written by +Dan Milstein, <author email="danmil@shore.net">danmil@shore.net</author> +on December 2000. The present document is generated out of an xml file +to allow a more easy integration in the Tomcat documentation. + +</p> + +<p> +This describes the Apache JServ Protocol version 1.3 (hereafter +<b>ajp13</b>). There is, apparently, no current documentation of how the +protocol works. This document is an attempt to remedy that, in order to +make life easier for maintainers of JK, and for anyone who wants to +port the protocol somewhere (into jakarta 4.x, for example). +</p> + +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="author"><strong>author</strong></a></font></td></tr><tr><td><blockquote> + +<p> +I am not one of the designers of this protocol -- I believe that Gal +Shachor was the original designer. Everything in this document is derived +from the actual implementation I found in the tomcat 3.x code. I hope it +is useful, but I can't make any grand claims to perfect accuracy. I also +don't know why certain design decisions were made. Where I was able, I've +offered some possible justifications for certain choices, but those are +only my guesses. In general, the C code which Shachor wrote is very clean +and comprehensible (if almost totally undocumented). I've cleaned up the +Java code, and I think it's reasonably readable. +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Design Goals"><strong>Design Goals</strong></a></font></td></tr><tr><td><blockquote> + +<p> +According to email from Gal Shachor to the jakarta-dev mailing list, +the original goals of <b>JK</b> (and thus <b>ajp13</b>) were to extend +<b>mod_jserv</b> and <b>ajp12</b> by (I am only including the goals which +relate to communication between the web server and the servlet container): + +<ul> + <li> Increasing performance (speed, specifically). </li> + + <li> Adding support for SSL, so that <b class="code">isSecure()</b> and + <b class="code">getScheme()</b> will function correctly within the servlet + container. The client certificates and cipher suite will be + available to servlets as request attributes. </li> + +</ul> +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Overview of the protocol"><strong>Overview of the protocol</strong></a></font></td></tr><tr><td><blockquote> + +<p> +The <b>ajp13</b> protocol is packet-oriented. A binary format was +presumably chosen over the more readable plain text for reasons of +performance. The web server communicates with the servlet container over +TCP connections. To cut down on the expensive process of socket creation, +the web server will attempt to maintain persistent TCP connections to the +servlet container, and to reuse a connection for multiple request/response +cycles. +</p><p> +Once a connection is assigned to a particular request, it will not be +used for any others until the request-handling cycle has terminated. In +other words, requests are not multiplexed over connections. This makes +for much simpler code at either end of the connection, although it does +cause more connections to be open at once. +</p><p> +Once the web server has opened a connection to the servlet container, +the connection can be in one of the following states: +</p><p> +<ul> + <li> Idle <br> No request is being handled over this connection. </li> + <li> Assigned <br> The connecton is handling a specific request.</li> +</ul> + +</p><p> +Once a connection is assigned to handle a particular request, the basic +request informaton (e.g. HTTP headers, etc) is sent over the connection in +a highly condensed form (e.g. common strings are encoded as integers). +Details of that format are below in Request Packet Structure. If there is a +body to the request (content-length > 0), that is sent in a separate +packet immediately after. +</p><p> +At this point, the servlet container is presumably ready to start +processing the request. As it does so, it can send the +following messages back to the web server: + +<ul> + <li>SEND_HEADERS <br>Send a set of headers back to the browser.</li> + + <li>SEND_BODY_CHUNK <br>Send a chunk of body data back to the browser.</li> + + <li>GET_BODY_CHUNK <br>Get further data from the request if it hasn't all + been transferred yet. This is necessary because the packets have a fixed + maximum size and arbitrary amounts of data can be included the body of a + request (for uploaded files, for example). (Note: this is unrelated to + HTTP chunked tranfer).</li> + + <li>END_RESPONSE <br> Finish the request-handling cycle.</li> +</ul> +</p><p> + +Each message is accompanied by a differently formatted packet of data. See +Response Packet Structures below for details. +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Basic Packet Structure"><strong>Basic Packet Structure</strong></a></font></td></tr><tr><td><blockquote> + +<p> +There is a bit of an XDR heritage to this protocol, but it differs in +lots of ways (no 4 byte alignment, for example). +</p><p> +Byte order: I am not clear about the endian-ness of the individual +bytes. I'm guessing the bytes are little-endian, because that's what XDR +specifies, and I'm guessing that sys/socket library is magically making +that so (on the C side). If anyone with a better knowledge of socket calls +can step in, that would be great. +</p><p> +There are four data types in the protocol: bytes, booleans, integers and +strings. + +<dl> + <dt><b>Byte</b></dt> + <dd>A single byte.</dd> + + <dt><b>Boolean</b></dt> + <dd>A single byte, 1 = true, 0 = false. Using other non-zero values as + true (i.e. C-style) may work in some places, but it won't in + others.</dd> + + <dt><b>Integer</b></dt> + <dd>A number in the range of 0 to 2^16 (32768). Stored in 2 bytes with + the high-order byte first.</dd> + + <dt><b>String</b></dt> + <dd>A variable-sized string (length bounded by 2^16). Encoded with the + length packed into two bytes first, followed by the string (including the + terminating '\0'). Note that the encoded length does <b>not</b> include + the trailing '\0' -- it is like <b class="code">strlen</b>. This is a touch + confusing on the Java side, which is littered with odd autoincrement + statements to skip over these terminators. I believe the reason this was + done was to allow the C code to be extra efficient when reading strings + which the servlet container is sending back -- with the terminating \0 + character, the C code can pass around references into a single buffer, + without copying. If the \0 was missing, the C code would have to copy + things out in order to get its notion of a string. Note a size of -1 + (65535) indicates a null string and no data follow the length in this + case.</dd> +</dl> +</p> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Packet Size"><strong>Packet Size</strong></a></font></td></tr><tr><td><blockquote> +<p> +According to much of the code, the max packet +size is 8 * 1024 bytes (8K). The actual length of the packet is encoded in the +header. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Packet Headers"><strong>Packet Headers</strong></a></font></td></tr><tr><td><blockquote> +<p> +Packets sent from the server to the container begin with +<b class="code">0x1234</b>. Packets sent from the container to the server begin +with <b class="code">AB</b> (that's the ASCII code for A followed by the ASCII +code for B). After those first two bytes, there is an integer (encoded as +above) with the length of the payload. Although this might suggest that +the maximum payload could be as large as 2^16, in fact, the code sets the +maximum to be 8K. + + +<table> + <tr> + <th colspan="6">Packet Format (Server->Container)</th> + </tr> + + <tr> + <th>Byte</th> + <td>0</td> + <td>1</td> + <td>2</td> + <td>3</td> + <td>4...(n+3)</td> + </tr> + + <tr> + <th>Contents</th> + <td>0x12</td> + <td>0x34</td> + <td colspan="2">Data Length (n)</td> + <td>Data</td> + </tr> +</table> + +<table> + <tr> + <th colspan="6"><b>Packet Format (Container->Server)</b></th> + </tr> + + <tr> + <th>Byte</th> + <td>0</td> + <td>1</td> + <td>2</td> + <td>3</td> + <td>4...(n+3)</td> + </tr> + + <tr> + <th>Contents</th> + <td>A</td> + <td>B</td> + <td colspan="2">Data Length (n)</td> + <td>Data</td> + </tr> +</table> +</p> +<p> +<A NAME="prefix-codes"></A> For most packets, the first byte of the +payload encodes the type of message. The exception is for request body +packets sent from the server to the container -- they are sent with a +standard packet header (0x1234 and then length of the packet), but without +any prefix code after that (this seems like a mistake to me). +</p><p> +The web server can send the following messages to the servlet container: + +<table> + <tr> + <th>Code</th> + <th>Type of Packet</th> + <th>Meaning</th> + </tr> + <tr> + <td>2</td> + <td>Forward Request</td> + <td>Begin the request-processing cycle with the following data</td> + </tr> + <tr> + <td>7</td> + <td>Shutdown</td> + <td>The web server asks the container to shut itself down.</td> + </tr> + <tr> + <td>8</td> + <td>Ping</td> + <td>The web server asks the container to take control (secure login phase).</td> + </tr> + <tr> + <td>10</td> + <td>CPing</td> + <td>The web server asks the container to respond quickly with a CPong.</td> + </tr> + <tr> + <td>none</td> + <td>Data</td> + <td>Size (2 bytes) and corresponding body data.</td> + </tr> +</table> +</p> +<p> +To ensure some +basic security, the container will only actually do the <b class="code">Shutdown</b> if the +request comes from the same machine on which it's hosted. +</p> +<p> +The first <b class="code">Data</b> packet is send immediatly after the <b class="code">Forward Request</b> by the web server. +</p> + +<p>The servlet container can send the following types of messages to the web +server: +<table> + <tr> + <th>Code</th> + <th>Type of Packet</th> + <th>Meaning</th> + </tr> + <tr> + <td>3</td> + <td>Send Body Chunk</td> + <td>Send a chunk of the body from the servlet container to the web + server (and presumably, onto the browser). </td> + </tr> + <tr> + <td>4</td> + <td>Send Headers</td> + <td>Send the response headers from the servlet container to the web + server (and presumably, onto the browser).</td> + </tr> + <tr> + <td>5</td> + <td>End Response</td> + <td>Marks the end of the response (and thus the request-handling cycle).</td> + </tr> + <tr> + <td>6</td> + <td>Get Body Chunk</td> + <td>Get further data from the request if it hasn't all been transferred + yet.</td> + </tr> + <tr> + <td>9</td> + <td>CPong Reply</td> + <td>The reply to a CPing request</td> + </tr> +</table> +</p> +<p> +Each of the above messages has a different internal structure, detailed below. +</p> +</blockquote></td></tr></table> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Request Packet Structure"><strong>Request Packet Structure</strong></a></font></td></tr><tr><td><blockquote> + +<p> +For messages from the server to the container of type "Forward Request": +</p><p> +<div class="example"><pre> +AJP13_FORWARD_REQUEST := + prefix_code (byte) 0x02 = JK_AJP13_FORWARD_REQUEST + method (byte) + protocol (string) + req_uri (string) + remote_addr (string) + remote_host (string) + server_name (string) + server_port (integer) + is_ssl (boolean) + num_headers (integer) + request_headers *(req_header_name req_header_value) + attributes *(attribut_name attribute_value) + request_terminator (byte) OxFF +</pre></div> +</p><p> +The <b class="code">request_headers</b> have the following structure: +</p><p> +<div class="example"><pre> +req_header_name := + sc_req_header_name | (string) [see below for how this is parsed] + +sc_req_header_name := 0xA0xx (integer) + +req_header_value := (string) +</pre></div> +</p><p> + +The <b class="code">attributes</b> are optional and have the following structure: +</p><p> +<div class="example"><pre> +attribute_name := sc_a_name | (sc_a_req_attribute string) + +attribute_value := (string) + +</pre></div> +</p><p> +Not that the all-important header is "content-length', because it +determines whether or not the container looks for another packet +immediately. +</p><p> +Detailed description of the elements of Forward Request. +</p> +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="request_prefix"><strong>request_prefix</strong></a></font></td></tr><tr><td><blockquote> +<p> +For all requests, this will be 2. +See above for details on other <A HREF="#prefix-codes">prefix codes</A>. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="method"><strong>method</strong></a></font></td></tr><tr><td><blockquote> +<p> +The HTTP method, encoded as a single byte: +</p> + +<p> +<table> + <tr><th>Command Name</th><th>Code</th></tr> + <tr><td>OPTIONS</td><td>1</td></tr> + <tr><td>GET</td><td>2</td></tr> + <tr><td>HEAD</td><td>3</td></tr> + <tr><td>POST</td><td>4</td></tr> + <tr><td>PUT</td><td>5</td></tr> + <tr><td>DELETE</td><td>6</td></tr> + <tr><td>TRACE</td><td>7</td></tr> + <tr><td>PROPFIND</td><td>8</td></tr> + <tr><td>PROPPATCH</td><td>9</td></tr> + <tr><td>MKCOL</td><td>10</td></tr> + <tr><td>COPY</td><td>11</td></tr> + <tr><td>MOVE</td><td>12</td></tr> + <tr><td>LOCK</td><td>13</td></tr> + <tr><td>UNLOCK</td><td>14</td></tr> + <tr><td>ACL</td><td>15</td></tr> + <tr><td>REPORT</td><td>16</td></tr> + <tr><td>VERSION-CONTROL</td><td>17</td></tr> + <tr><td>CHECKIN</td><td>18</td></tr> + <tr><td>CHECKOUT</td><td>19</td></tr> + <tr><td>UNCHECKOUT</td><td>20</td></tr> + <tr><td>SEARCH</td><td>21</td></tr> + <tr><td>MKWORKSPACE</td><td>22</td></tr> + <tr><td>UPDATE</td><td>23</td></tr> + <tr><td>LABEL</td><td>24</td></tr> + <tr><td>MERGE</td><td>25</td></tr> + <tr><td>BASELINE_CONTROL</td><td>26</td></tr> + <tr><td>MKACTIVITY</td><td>27</td></tr> +</table> +</p> + +<p>Later version of ajp13, when used with mod_jk2, will transport +additional methods, even if they are not in this list. +</p> + +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="protocol, req_uri, remote_addr, remote_host, server_name, server_port, is_ssl"><strong>protocol, req_uri, remote_addr, remote_host, server_name, server_port, is_ssl</strong></a></font></td></tr><tr><td><blockquote> +<p> + These are all fairly self-explanatory. Each of these is required, and + will be sent for every request. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Headers"><strong>Headers</strong></a></font></td></tr><tr><td><blockquote> +<p> + The structure of <b class="code">request_headers</b> is the following: + First, the number of headers <b class="code">num_headers</b> is encoded. + Then, a series of header name <b class="code">req_header_name</b> / value + <b class="code">req_header_value</b> pairs follows. + Common header names are encoded as integers, + to save space. If the header name is not in the list of basic headers, + it is encoded normally (as a string, with prefixed length). The list of + common headers <b class="code">sc_req_header_name</b>and their codes + is as follows (all are case-sensitive): +</p><p> +<table> + <tr><th>Name</th><th>Code value</th><th>Code name</th></tr> + <tr><td>accept</td><td>0xA001</td><td>SC_REQ_ACCEPT</td></tr> + <tr><td>accept-charset</td><td>0xA002</td><td>SC_REQ_ACCEPT_CHARSET</td></tr> + <tr><td>accept-encoding</td><td>0xA003</td><td>SC_REQ_ACCEPT_ENCODING</td></tr> + <tr><td>accept-language</td><td>0xA004</td><td>SC_REQ_ACCEPT_LANGUAGE</td></tr> + <tr><td>authorization</td><td>0xA005</td><td>SC_REQ_AUTHORIZATION</td></tr> + <tr><td>connection</td><td>0xA006</td><td>SC_REQ_CONNECTION</td></tr> + <tr><td>content-type</td><td>0xA007</td><td>SC_REQ_CONTENT_TYPE</td></tr> + <tr><td>content-length</td><td>0xA008</td><td>SC_REQ_CONTENT_LENGTH</td></tr> + <tr><td>cookie</td><td>0xA009</td><td>SC_REQ_COOKIE</td></tr> + <tr><td>cookie2</td><td>0xA00A</td><td>SC_REQ_COOKIE2</td></tr> + <tr><td>host</td><td>0xA00B</td><td>SC_REQ_HOST</td></tr> + <tr><td>pragma</td><td>0xA00C</td><td>SC_REQ_PRAGMA</td></tr> + <tr><td>referer</td><td>0xA00D</td><td>SC_REQ_REFERER</td></tr> + <tr><td>user-agent</td><td>0xA00E</td><td>SC_REQ_USER_AGENT</td></tr> +</table> +</p><p> + The Java code that reads this grabs the first two-byte integer and if + it sees an <b class="code">'0xA0'</b> in the most significant + byte, it uses the integer in the second byte as an index into an array of + header names. If the first byte is not '0xA0', it assumes that the + two-byte integer is the length of a string, which is then read in. +</p><p> + This works on the assumption that no header names will have length + greater than 0x9999 (==0xA000 - 1), which is perfectly reasonable, though + somewhat arbitrary. (If you, like me, started to think about the cookie + spec here, and about how long headers can get, fear not -- this limit is + on header <b>names</b> not header <b>values</b>. It seems unlikely that + unmanageably huge header names will be showing up in the HTTP spec any time + soon). +</p><p> + <b>Note:</b> The <b class="code">content-length</b> header is extremely + important. If it is present and non-zero, the container assumes that + the request has a body (a POST request, for example), and immediately + reads a separate packet off the input stream to get that body. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Attributes"><strong>Attributes</strong></a></font></td></tr><tr><td><blockquote> +<p> + + The attributes prefixed with a <b class="code">?</b> + (e.g. <b class="code">?context</b>) are all optional. For each, there is a + single byte code to indicate the type of attribute, and then a string to + give its value. They can be sent in any order (thogh the C code always + sends them in the order listed below). A special terminating code is + sent to signal the end of the list of optional attributes. The list of + byte codes is: +</p><p> + +<table> + <tr><th>Information</th><th>Code Value</th><th>Note</th></tr> + <tr><td>?context</td><td>0x01</td><td>Not currently implemented</td></tr> + <tr><td>?servlet_path</td><td>0x02</td><td>Not currently implemented</td></tr> + <tr><td>?remote_user</td><td>0x03</td><td></td></tr> + <tr><td>?auth_type</td><td>0x04</td><td></td></tr> + <tr><td>?query_string</td><td>0x05</td><td></td></tr> + <tr><td>?route</td><td>0x06</td><td></td></tr> + <tr><td>?ssl_cert</td><td>0x07</td><td></td></tr> + <tr><td>?ssl_cipher</td><td>0x08</td><td></td></tr> + <tr><td>?ssl_session</td><td>0x09</td><td></td></tr> + <tr><td>?req_attribute</td><td>0x0A</td><td>Name (the name of the attribut follows)</td></tr> + <tr><td>?ssl_key_size</td><td>0x0B</td><td></td></tr> + <tr><td>?secret</td><td>0x0C</td><td></td></tr> + <tr><td>?stored_method</td><td>0x0D</td><td></td></tr> + <tr><td>are_done</td><td>0xFF</td><td>request_terminator</td></tr> +</table> + +</p><p> + + The <b class="code">context</b> and <b class="code">servlet_path</b> are not currently + set by the C code, and most of the Java code completely ignores whatever + is sent over for those fields (and some of it will actually break if a + string is sent along after one of those codes). I don't know if this is + a bug or an unimplemented feature or just vestigial code, but it's + missing from both sides of the connection. +</p><p> + The <b class="code">remote_user</b> and <b class="code">auth_type</b> presumably refer + to HTTP-level authentication, and communicate the remote user's username + and the type of authentication used to establish their identity (e.g. Basic, + Digest). I'm not clear on why the password isn't also sent, but I don't + know HTTP authentication inside and out. +</p><p> + The <b class="code">query_string</b>, <b class="code">ssl_cert</b>, + <b class="code">ssl_cipher</b>, and <b class="code">ssl_session</b> refer to the + corresponding pieces of HTTP and HTTPS. +</p><p> + The <b class="code">route</b>, as I understand it, is used to support sticky + sessions -- associating a user's sesson with a particular Tomcat instance + in the presence of multiple, load-balancing servers. I don't know the + details. +</p><p> + Beyond this list of basic attributes, any number of other attributes can + be sent via the <b class="code">req_attribute</b> code (0x0A). A pair of strings + to represent the attribute name and value are sent immediately after each + instance of that code. Environment values are passed in via this method. +</p><p> + Finally, after all the attributes have been sent, the attribute terminator, + 0xFF, is sent. This signals both the end of the list of attributes and + also then end of the Request Packet. +</p> +</blockquote></td></tr></table> + +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Response Packet Structure"><strong>Response Packet Structure</strong></a></font></td></tr><tr><td><blockquote> + +<p> +For messages which the container can send back to the server. + +<div class="example"><pre> +AJP13_SEND_BODY_CHUNK := + prefix_code 3 + chunk_length (integer) + chunk *(byte) + + +AJP13_SEND_HEADERS := + prefix_code 4 + http_status_code (integer) + http_status_msg (string) + num_headers (integer) + response_headers *(res_header_name header_value) + +res_header_name := + sc_res_header_name | (string) [see below for how this is parsed] + +sc_res_header_name := 0xA0 (byte) + +header_value := (string) + +AJP13_END_RESPONSE := + prefix_code 5 + reuse (boolean) + + +AJP13_GET_BODY_CHUNK := + prefix_code 6 + requested_length (integer) +</pre></div> + +</p> +<p> +Details: +</p> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Send Body Chunk"><strong>Send Body Chunk</strong></a></font></td></tr><tr><td><blockquote> +<p> + The chunk is basically binary data, and is sent directly back to the browser. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Send Headers"><strong>Send Headers</strong></a></font></td></tr><tr><td><blockquote> +<p> + The status code and message are the usual HTTP things (e.g. "200" and "OK"). + The response header names are encoded the same way the request header names are. + See <A HREF="#header_encoding">above</A> for details about how the the + codes are distinguished from the strings. The codes for common headers are: +</p> + +<p> +<table> + <tr><th>Name</th><th>Code value</th></tr> + <tr><td>Content-Type</td><td>0xA001</td></tr> + <tr><td>Content-Language</td><td>0xA002</td></tr> + <tr><td>Content-Length</td><td>0xA003</td></tr> + <tr><td>Date</td><td>0xA004</td></tr> + <tr><td>Last-Modified</td><td>0xA005</td></tr> + <tr><td>Location</td><td>0xA006</td></tr> + <tr><td>Set-Cookie</td><td>0xA007</td></tr> + <tr><td>Set-Cookie2</td><td>0xA008</td></tr> + <tr><td>Servlet-Engine</td><td>0xA009</td></tr> + <tr><td>Status</td><td>0xA00A</td></tr> + <tr><td>WWW-Authenticate</td><td>0xA00B</td></tr> +</table> + +</p> + +<p> + After the code or the string header name, the header value is immediately + encoded. +</p> + +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="End Response"><strong>End Response</strong></a></font></td></tr><tr><td><blockquote> +<p> + Signals the end of this request-handling cycle. If the + <b class="code">reuse</b> flag is true (==1), this TCP connection can now be used to + handle new incoming requests. If <b class="code">reuse</b> is false (anything + other than 1 in the actual C code), the connection should be closed. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Get Body Chunk"><strong>Get Body Chunk</strong></a></font></td></tr><tr><td><blockquote> +<p> + The container asks for more data from the request (If the body was + too large to fit in the first packet sent over or when the request is + chuncked). + The server will send a body packet back with an amount of data which is + the minimum of the <b class="code">request_length</b>, + the maximum send body size (8186 (8 Kbytes - 6)), and the + number of bytes actually left to send from the request body. +<br> + If there is no more data in the body (i.e. the servlet container is + trying to read past the end of the body), the server will send back an + "empty" packet, which is a body packet with a payload length of 0. + (0x12,0x34,0x00,0x00) +</p> +</blockquote></td></tr></table> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Questions I Have"><strong>Questions I Have</strong></a></font></td></tr><tr><td><blockquote> + +<p> What happens if the request headers > max packet size? There is no +provision to send a second packet of request headers in case there are more +than 8K (I think this is correctly handled for response headers, though I'm +not certain). I don't know if there is a way to get more than 8K worth of +data into that initial set of request headers, but I'll bet there is +(combine long cookies with long ssl information and a lot of environment +variables, and you should hit 8K easily). I think the connector would just +fail before trying to send any headers in this case, but I'm not certain.</p> + +<p> What about authentication? There doesn't seem to be any authentication +of the connection between the web server and the container. This strikes +me as potentially dangerous.</p> + +</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em> + Copyright © 1999-2011, Apache Software Foundation + </em></font></div></td></tr></table></body></html>
\ No newline at end of file diff --git a/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/printer/ajpv13ext.html b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/printer/ajpv13ext.html new file mode 100644 index 00000000..300f4b3c --- /dev/null +++ b/rubbos/app/tomcat-connectors-1.2.32-src/docs/ajp/printer/ajpv13ext.html @@ -0,0 +1,653 @@ +<html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>The Apache Tomcat Connector - AJP Protocol Reference - AJPv13 extensions Proposal</title><meta name="author" value="Henri Gomez"><meta name="email" value="hgomez@apache.org"><link href="../../style.css" type="text/css" rel="stylesheet"></head><body bgcolor="#ffffff" text="#000000" link="#525D76" alink="#525D76" vlink="#525D76"><table border="0" width="100%" cellspacing="4"><!--PAGE HEADER--><tr><td colspan="2"><!--TOMCAT LOGO--><a href="http://tomcat.apache.org/"><img src="../../images/tomcat.gif" align="left" alt="Apache Tomcat" border="0"></a><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="http://www.apache.org/images/asf-logo.gif" align="right" alt="Apache Logo" border="0"></a></td></tr><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><tr><!--RIGHT SIDE MAIN BODY--><td width="80%" valign="top" align="left"><table border="0" width="100%" cellspacing="4"><tr><td align="left" valign="top"><h1>The Apache Tomcat Connector - AJP Protocol Reference</h1><h2>AJPv13 extensions Proposal</h2></td><td align="right" valign="top" nowrap="true"><img src="../../images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> +<p> +This document is a proposal of evolution of the current +Apache JServ Protocol version 1.3, also known as ajp13. +I'll not cover here the full protocol but only the add-on from ajp13. + +This nth pass include comments from the tomcat-dev list and +misses discovered during developpment. +</p> +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Missing features in AJP13"><strong>Missing features in AJP13</strong></a></font></td></tr><tr><td><blockquote> +<p> +ajp13 is a good protocol to link a servlet engine like tomcat to a web server like Apache: + +<ul> +<li> +use persistants connections to avoid reconnect time at each request +</li> +<li> +encode many http commands to reduce stream size +</li> +<li> +send to servlet engine many info from web server (like SSL certs) +</li> +</ul> +<p> +But ajp13 lacks support for : +</p> +<ul> +<li> + security between web server and servlet engine. + Anybody can connect to an ajp13 port (no login mecanism used) + You could connect, for example with telnet, and keep the remote thread + up by not sending any data (no timeout in connection) +</li> +<li> + context information passed from servlet engine to web server. + Part of the configuration of JK, the web server connector, is to + indicate to the web server which URI to handle. + The mod_jk JkMount directive, told to web server which URI must be + forwarded to servlet engine. + A servlet engine allready knows which URI it handle and TC 3.3 is + allready capable to generate a config file for JK from the list + of available contexts. +</li> +<li> + state update of contexts from servlet engine to web server. + Big site with farm of Tomcat, like ISP and virtuals hosters, + may need to stop a context for admin purposes. In that case the front + web server must know that the context is currently down, to eventually + relay the request to another Tomcat +</li> +<li> + verify state of connection before sending request. + Actually JK send the request to the servlet engine and next wait + for the answer. But one of the beauty of the socket API, is you that + you could write() to a closed connection without any error reporting, + but a read() to a closed connection return you the error code. +</li> +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Proposed add-ons to AJP13"><strong>Proposed add-ons to AJP13</strong></a></font></td></tr><tr><td><blockquote> +<p> +Let's descrive here the features and add-on that could be added to AJP13. +Since this document is a proposal, a reasonable level of chaos must be expected at first. +Be sure that discussion on tomcat list will help clarify points, add +features but the current list seems to be a 'minimun vital' + +<ul> + +<li> +Advanced login features at connect time +</li> + +<li> +Basic authorisation system, where a shared secret key is +present in web server and servlet engine. +</li> + +<li> +Basic protocol negociation, just to be sure that if functionnalities are added +to AJP13 in the future, current implementations will still works. +</li> + +<li> +Clean handling of 'Unknown packets' +</li> + +<li> +Extended env vars passed from web-server to servlet engine. +</li> + +<li> +Add extra SSL informations needed by Servlet 2.3 API (like SSL_KEY_SIZE) +</li> + +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Advanced login"><strong>Advanced login</strong></a></font></td></tr><tr><td><blockquote> +<p> + +<ol> +<li> +WEB-SERVER send LOGIN INIT CMD + NEGOCIATION DATA + WEB SERVER INFO +</li> +<li> + TOMCAT respond with LOGIN SEED CMD + RANDOM DATA +</li> +<li> + WEB-SERVER calculted the MD5 of RANDOM DATA+SECRET DATA +</li> +<li> + WEB-SERVER send LOGIN COMP CMD + MD5 (SECRET DATA + RANDOM DATA) +</li> +<li> + TOMCAT respond with LOGIN STATUS CMD + NEGOCIED DATA + SERVLET ENGINE INFO +</li> +</ol> + +To prevent DOS attack, the servlet engine will wait +the LOGIN CMD only 15/30 seconds and reports the +timeout exception for admins investigation. + +The login command will contains basic protocol +negociation information like compressing ability, +crypto, context info (at start up), context update at +run-time (up/down), level of SSL env vars, AJP protocol +level supported (level1/level2/level3...) + +The Web server info will contain web server info and +connector name (ie Apache 1.3.26 + mod_ssl 2.8.8 + mod_jk 1.2.1 + mod_perl 1.25). + +The servlet engine will mask the negociation mask with it's own +mask (what it can do) and return it when loggin is accepted. + +This will help having a basic AJP13 implementation (level 1) +on a web-server working with a more advanced protocol handler on +the servlet engine side or vice-versa. + +AJP13 was designed to be small and fast and so many +SSL informations present in the web-server are not +forwarded to the servlet engine. + +We add here four negociations flags to provide more +informations on client SSL data (certs), server SSL datas, +crypto used, and misc datas (timeout...). +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Messages Stream"><strong>Messages Stream</strong></a></font></td></tr><tr><td><blockquote> +<p> +<div class="example"><pre> ++----------------+------------------+-----------------+ +| LOGIN INIT CMD | NEGOCIATION DATA | WEB SERVER INFO | ++----------------+------------------+-----------------+ + ++----------------+----------------+ +| LOGIN SEED CMD | MD5 of entropy | ++----------------+----------------+ + ++----------------+----------------------------+ +| LOGIN COMP CMD | MD5 of RANDOM + SECRET KEY | ++----------------+----------------------------+ + ++-----------+---------------+---------------------+ +| LOGOK CMD | NEGOCIED DATA | SERVLET ENGINE INFO | ++-----------+---------------+---------------------+ + ++------------+--------------+ +| LOGNOK CMD | FAILURE CODE | ++------------+--------------+ +</pre></div> + +<ul> +<li> +LOGIN INIT CMD, LOGIN SEED CMD, LOGIN COMP CMD, LOGOK CMD, LOGNOK CMD are 1 byte long. +</li> +<li> +MD5, MD5 of RANDOM + SECRET KEY are 32 chars long. +</li> +<li> +NEGOCIATION DATA, NEGOCIED DATA, FAILURE CODE are 32 bits long. +</li> +<li> +WEB SERVER INFO, SERVLET ENGINE INFO are CString. +</li> +</ul> + +The secret key will be set by a new propertie in +workers.properties : secretkey +<div class="example"><pre> +worker.ajp13.port=8009 +worker.ajp13.host=localhost +worker.ajp13.type=ajp13 +worker.ajp13.secretkey=myverysecretkey +</pre></div> +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Shutdown feature"><strong>Shutdown feature</strong></a></font></td></tr><tr><td><blockquote> +<p> +AJP13 miss a functionnality of AJP12, which is shutdown command. +A logout will tell servlet engine to shutdown itself. +<div class="example"><pre> ++--------------+----------------------------+ +| SHUTDOWN CMD | MD5 of RANDOM + SECRET KEY | ++--------------+----------------------------+ + ++------------+ +| SHUTOK CMD | ++------------+ + ++-------------+--------------+ +| SHUTNOK CMD | FAILURE CODE | ++-------------+--------------+ +</pre></div> + +<ul> +<li> +SHUTDOWN CMD, SHUTOK CMD, SHUTNOK CMD are 1 byte long. +</li> +<li> +MD5 of RANDOM + SECRET KEY are 32 chars long. +</li> +<li> +FAILURE CODE is 32 bits long. +</li> +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Extended Env Vars feature"><strong>Extended Env Vars feature</strong></a></font></td></tr><tr><td><blockquote> +<p> +NOTA: + +While working on AJP13 in JK, I really discovered "JkEnvVar". +The following "Extended Env Vars feature" description may not +be implemented in extended AJP13 since allready available in original +implementation. + +DESC: + +Many users will want to see some of their web-server env vars +passed to their servlet engine. + +To reduce the network traffic, the web-servlet will send a +table to describing the external vars in a shorter fashion. + +We'll use there a functionnality allready present in AJP13, +attributes list : + +In the AJP13, we've got : + +<div class="example"><pre> +AJP13_FORWARD_REQUEST := + prefix_code 2 + method (byte) + protocol (string) + req_uri (string) + remote_addr (string) + remote_host (string) + server_name (string) + server_port (integer) + is_ssl (boolean) + num_headers (integer) + request_headers *(req_header_name req_header_value) + + ?context (byte string) + ?servlet_path (byte string) + ?remote_user (byte string) + ?auth_type (byte string) + ?query_string (byte string) + ?route (byte string) + ?ssl_cert (byte string) + ?ssl_cipher (byte string) + ?ssl_session (byte string) + + ?attributes *(attribute_name attribute_value) + request_terminator (byte) +</pre></div> + +Using short 'web server attribute name' will reduce the +network traffic. + +<div class="example"><pre> ++-------------------+---------------------------+-------------------------------+----+ +| EXTENDED VARS CMD | WEB SERVER ATTRIBUTE NAME | SERVLET ENGINE ATTRIBUTE NAME | ES | ++-------------------+---------------------------+-------------------------------+----+ +</pre></div> + +ie : + +<div class="example"><pre> +JkExtVars S1 SSL_CLIENT_V_START javax.servlet.request.ssl_start_cert_date +JkExtVars S2 SSL_CLIENT_V_END javax.servlet.request.ssl_end_cert_date +JkExtVars S3 SSL_SESSION_ID javax.servlet.request.ssl_session_id + + ++-------------------+----+-------------------------------------------+ +| EXTENDED VARS CMD | S1 | javax.servlet.request.ssl_start_cert_date | ++-------------------+----+-------------------------------------------+ ++----+-----------------------------------------+ +| S2 | javax.servlet.request.ssl_end_cert_date | ++----+-----------------------------------------+ ++----+-----------------------------------------+ +| S3 | javax.servlet.request.ssl_end_cert_date | ++----+-----------------------------------------+ +</pre></div> + +During transmission in extended AJP13 we'll see attributes name +containing S1, S2, S3 and attributes values of +2001/01/03, 2002/01/03, 0123AFE56. + +This example showed the use of extended SSL vars but +any 'personnal' web-server vars like custom authentification +vars could be reused in the servlet engine. +The cost will be only some more bytes in the AJP traffic. + +<ul> +<li> +EXTENDED VARS CMD is 1 byte long. +</li> +<li> +WEB SERVER ATTRIBUTE NAME, SERVLET ENGINE ATTRIBUTE NAME are CString. +</li> +<li> +ES is an empty CString. +</li> +</ul> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Context informations forwarding for Servlet engine to Web Server"><strong>Context informations forwarding for Servlet engine to Web Server</strong></a></font></td></tr><tr><td><blockquote> +<p> +Just after the LOGON PHASE, the web server will ask for the list of contexts +and URLs/URIs handled by the servlet engine. +It will ease installation in many sites, reduce questions about configuration +on tomcat-user list, and be ready for servlet API 2.3. + +This mode will be activated by a new directive JkAutoMount + +ie: JkAutoMount examples myworker1 /examples/ + +If we want to get ALL the contexts handled by the servlet engine, willcard +could be used : + +ie: JkAutoMount * myworker1 * + +A servlet engine could have many contexts, /examples, /admin, /test. +We may want to use only some contexts for a given worker. It was +done previously, in apache HTTP server for example, by setting by +hand the JkMount accordingly in each [virtual] area of Apache. + +If you web-server support virtual hosting, we'll forward also that +information to servlet engine which will only return contexts for +that virtual host. +In that case the servlet engine will only return the URL/URI matching +these particular virtual server (defined in server.xml). +This feature will help ISP and big sites which mutualize large farm +of Tomcat in load-balancing configuration. + +<div class="example"><pre> ++-----------------+-------------------+----------+----------+----+ +| CONTEXT QRY CMD | VIRTUAL HOST NAME | CONTEXTA | CONTEXTB | ES | ++-----------------+-------------------+----------+----------+----+ + ++------------------+-------------------+----------+-------------------+----------+---------------+----+ +| CONTEXT INFO CMD | VIRTUAL HOST NAME | CONTEXTA | URL1 URL2 URL3 ES | CONTEXTB | URL1 URL2 ... | ES | ++------------------+-------------------+----------+-------------------+----------+---------------+----+ +</pre></div> + +We'll discover via context-query, the list of URL/MIMES handled by the remove servlet engine +for a list of contextes. +In wildcard mode, CONTEXTA will contains just '*'. + +<ul> +<li> +CONTEXT QRY CMD and CONTEXT INFO CMD are 1 byte long. +</li> +<li> +VIRTUAL HOST NAME is a CString, ie an array of chars terminated by a null byte (/0). +</li> +<li> +An empty string is just a null byte (/0). +</li> +<li> +ES is an empty CString. Indicate end of URI/URLs or end of CONTEXTs. +</li> +</ul> + +NB:<br> +When VirtualMode is not to be used, the VIRTUAL HOST NAME is '*'. +In that case the servlet engine will send all contexts handled. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Context informations updates from Servlet engine to Web Server"><strong>Context informations updates from Servlet engine to Web Server</strong></a></font></td></tr><tr><td><blockquote> +<p> +Context update are messages caming from the servlet engine each time a context +is desactivated/reactivated. The update will be in use when the directive JkUpdateMount. +This directive will set the AJP13_CONTEXT_UPDATE_NEG flag. + +ie: JkUpdateMount myworker1 + +<div class="example"><pre> ++--------------------+-------------------+----------+--------+----------+--------+----+ +| CONTEXT UPDATE CMD | VIRTUAL HOST NAME | CONTEXTA | STATUS | CONTEXTB | STATUS | ES | ++--------------------+-------------------+----------+--------+----------+--------+----+ +</pre></div> + +<ul> +<li> +CONTEXT UPDATE CMD, STATUS are 1 byte long. +</li> +<li> +VIRTUAL HOST NAME, CONTEXTS are CString. +</li> +<li> +ES is an empty CString. Indicate end of CONTEXTs. +</li> +</ul> + +NB:<br> +When VirtualMode is not in use, the VIRTUAL HOST NAME is '*'. +STATUS is one byte indicating if context is UP/DOWN/INVALID +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Context status query to Servlet engine"><strong>Context status query to Servlet engine</strong></a></font></td></tr><tr><td><blockquote> +<p> +This query will be used by the web-server to determine if a given +contexts are UP, DOWN or INVALID (and should be removed). + +<div class="example"><pre> ++-------------------+--------------------+----------+----------+----+ +| CONTEXT STATE CMD | VIRTUAL HOST NAME | CONTEXTA | CONTEXTB | ES | ++-------------------+--------------------+----------+----------+----+ + ++-------------------------+-------------------+----------+--------+----------+--------+----+ +| CONTEXT STATE REPLY CMD | VIRTUAL HOST NAME | CONTEXTA | STATUS | CONTEXTB | STATUS | ES | ++-------------------------+-------------------+----------+-------------------+--------+----+ +</pre></div> + +<ul> +<li> +CONTEXT STATE CMD, CONTEXT STATE REPLY CMD, STATUS are 1 byte long. +</li> +<li> +VIRTUAL HOST NAME, CONTEXTs are CString +</li> +<li> +ES is an empty CString +</li> +</ul> + +NB:<br> +When VirtualMode is not in use, the VIRTUAL HOST NAME is an empty string. +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Handling of unknown packets"><strong>Handling of unknown packets</strong></a></font></td></tr><tr><td><blockquote> +<p> +Sometimes even with a well negocied protocol, we may be in a situation +where one end (web server or servlet engine), will receive a message it +couldn't understand. In that case the receiver will send an +'UNKNOW PACKET CMD' with attached the unhandled message. + +<div class="example"><pre> ++--------------------+------------------------+-------------------+ +| UNKNOWN PACKET CMD | UNHANDLED MESSAGE SIZE | UNHANDLED MESSAGE | ++--------------------+------------------------+-------------------+ +</pre></div> + +Depending on the message, the sender will report an error and if +possible will try to forward the message to another endpoint. + +<ul> +<li> +UNKNOWN PACKET CMD is 1 byte long. +</li> +<li> +UNHANDLED MESSAGE SIZE is 16bits long. +</li> +<li> +UNHANDLED MESSAGE is an array of byte (length is contained in UNHANDLED MESSAGE SIZE) +</li> +</ul> + +NB:<br> +added UNHANDLED MESSAGE SIZE (development) +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Verification of connection before sending request"><strong>Verification of connection before sending request</strong></a></font></td></tr><tr><td><blockquote> +<p> +NOTA: This fonctionality may never be used, since it may slow up the normal process +since requiring on the web-server side an extra IO (read) before forwarding +the request..... + +One of the beauty of socket APIs, is that you could write on a half closed socket. +When servlet engine close the socket, the web server will discover it only at the +next read() to the socket. +Basically, in the AJP13 protocol, the web server send the HTTP HEADER and HTTP BODY +(POST by chunk of 8K) to the servlet engine and then try to receive the reply. +If the connection was broken the web server will learn it only at receive time. + +We could use a buffering scheme but what happen when you use the servlet engine +for upload operations with more than 8ko of datas ? + +The hack in the AJP13 protocol is to add some bytes to read after the end of the +service : + +<div class="example"><pre> +EXAMPLE OF DISCUSSION BETWEEN WEB SERVER AND SERVLET ENGINE + +AJP HTTP-HEADER (+ HTTP-POST) (WEB->SERVLET) + +AJP HTTP-REPLY (SERVLET->WEB) + +AJP END OF DISCUSSION (SERVLET->WEB) + +---> AJP STATUS (SERVLET->WEB AJP13) +</pre></div> + +The AJP STATUS will not be read by the servlet engine at the end of +the request/response #N but at the begining of the next session. + +More at that time the web server could also use OS dependants functions +(or better APR functions) to determine if there is also more data +to read. And that datas could be CONTEXT Updates. + +This will avoid the web server sending a request to a +desactivated context. In that case, if the load-balancing is used, +it will search for another servlet engine to handle the request. + +And that feature will help ISP and big sites with farm of tomcat, +to updates their servlet engine without any service interruption. + +<div class="example"><pre> ++------------+-------------+ +| STATUS CMD | STATUS DATA | ++------------+-------------+ +</pre></div> + +<ul> +<li> +STATUS CMD and STATUS DATA are one byte long. +</li> +</ul> +</p> +</blockquote></td></tr></table> + +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Conclusion"><strong>Conclusion</strong></a></font></td></tr><tr><td><blockquote> +<p> +The goal of the extended AJP13 protocol is to overcome some of the original AJP13 limitation. +An easier configuration, a better support for large site and farm of Tomcat, +a simple authentification system and provision for protocol updates. + +Using the stable ajp13 implementation in JK (native) and in servlet +engine (java), it's a reasonable evolution of the well known ajp13. +</p> +</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Commands and IDs in extended AJP13 Index"><strong>Commands and IDs in extended AJP13 Index</strong></a></font></td></tr><tr><td><blockquote> +<p> +Index of Commands and ID to be added in AJP13 Protocol +</p> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Commands IDs"><strong>Commands IDs</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Command Name</th><th>Command Number</th></tr> + <tr><td>AJP13_LOGINIT_CMD</td><td>0x10</td></tr> + <tr><td>AJP13_LOGSEED_CMD</td><td>0x11</td></tr> + <tr><td>AJP13_LOGCOMP_CMD</td><td>0x12</td></tr> + <tr><td>AJP13_LOGOK_CMD</td><td>0x13</td></tr> + <tr><td>AJP13_LOGNOK_CMD</td><td>0x14</td></tr> + <tr><td>AJP13_CONTEXT_QRY_CMD</td><td>0x15</td></tr> + <tr><td>AJP13_CONTEXT_INFO_CMD</td><td>0x16</td></tr> + <tr><td>AJP13_CONTEXT_UPDATE_CMD</td><td>0x17</td></tr> + <tr><td>AJP13_STATUS_CMD</td><td>0x18</td></tr> + <tr><td>AJP13_SHUTDOWN_CMD</td><td>0x19</td></tr> + <tr><td>AJP13_SHUTOK_CMD</td><td>0x1A</td></tr> + <tr><td>AJP13_SHUTNOK_CMD</td><td>0x1B</td></tr> + <tr><td>AJP13_CONTEXT_STATE_CMD</td><td>0x1C</td></tr> + <tr><td>AJP13_CONTEXT_STATE_REP_CMD</td><td>0x1D</td></tr> + <tr><td>AJP13_UNKNOW_PACKET_CMD</td><td>0x1E</td></tr> +</table> + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Negociations Flags"><strong>Negociations Flags</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Command Name</th><th>Number</th><th>Description</th></tr> + <tr><td>AJP13_CONTEXT_INFO_NEG</td><td>0x80000000</td><td>web-server want context info after login</td></tr> + <tr><td>AJP13_CONTEXT_UPDATE_NEG</td><td>0x40000000</td><td>web-server want context updates</td></tr> + <tr><td>AJP13_GZIP_STREAM_NEG</td><td>0x20000000</td><td>web-server want compressed stream</td></tr> + <tr><td>AJP13_DES56_STREAM_NEG</td><td>0x10000000</td><td>web-server want crypted DES56 stream with secret key</td></tr> + <tr><td>AJP13_SSL_VSERVER_NEG</td><td>0x08000000</td><td>Extended info on server SSL vars</td></tr> + <tr><td>AJP13_SSL_VCLIENT_NEG</td><td>0x04000000</td><td>Extended info on client SSL vars</td></tr> + <tr><td>AJP13_SSL_VCRYPTO_NEG</td><td>0x02000000</td><td>Extended info on crypto SSL vars</td></tr> + <tr><td>AJP13_SSL_VMISC_NEG</td><td>0x01000000</td><td>Extended info on misc SSL vars</td></tr> +</table> + +<br> + +<table> + <tr><th>Negociation ID</th><th>Number</th><th>Description</th></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJPXX_NEG</td><td>0x00FF0000</td><td>mask of protocol supported</td></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJP13L1_NEG</td><td>0x00010000</td><td>communication could use AJP13 Level 1</td></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJP13L2_NEG</td><td>0x00020000</td><td>communication could use AJP13 Level 2</td></tr> + <tr><td>AJP13_PROTO_SUPPORT_AJP13L3_NEG</td><td>0x00040000</td><td>communication could use AJP13 Level 3</td></tr> +</table> + +<br> +All others flags must be set to 0 since they are reserved for future use. + +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Failure IDs"><strong>Failure IDs</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Failure Id</th><th>Number</th></tr> + <tr><td>AJP13_BAD_KEY_ERR</td><td>0xFFFFFFFF</td></tr> + <tr><td>AJP13_ENGINE_DOWN_ERR</td><td>0xFFFFFFFE</td></tr> + <tr><td>AJP13_RETRY_LATER_ERR</td><td>0xFFFFFFFD</td></tr> + <tr><td>AJP13_SHUT_AUTHOR_FAILED_ERR</td><td>0xFFFFFFFC</td></tr> +</table> +</p> +</blockquote></td></tr></table> + +<table border="0" cellspacing="0" cellpadding="2" width="100%"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Status"><strong>Status</strong></a></font></td></tr><tr><td><blockquote> +<p> +<table> + <tr><th>Failure Id</th><th>Number</th></tr> + <tr><td>AJP13_CONTEXT_DOWN</td><td>0x01</td></tr> + <tr><td>AJP13_CONTEXT_UP</td><td>0x02</td></tr> + <tr><td>AJP13_CONTEXT_OK</td><td>0x03</td></tr> +</table> +</p> +</blockquote></td></tr></table> + +</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em> + Copyright © 1999-2011, Apache Software Foundation + 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