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Diffstat (limited to 'rubbos/app/httpd-2.0.64/modules/ssl/ssl_scache_shmcb.c')
| -rw-r--r-- | rubbos/app/httpd-2.0.64/modules/ssl/ssl_scache_shmcb.c | 1362 |
1 files changed, 1362 insertions, 0 deletions
diff --git a/rubbos/app/httpd-2.0.64/modules/ssl/ssl_scache_shmcb.c b/rubbos/app/httpd-2.0.64/modules/ssl/ssl_scache_shmcb.c new file mode 100644 index 00000000..cee66bf5 --- /dev/null +++ b/rubbos/app/httpd-2.0.64/modules/ssl/ssl_scache_shmcb.c @@ -0,0 +1,1362 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* _ _ + * _ __ ___ ___ __| | ___ ___| | mod_ssl + * | '_ ` _ \ / _ \ / _` | / __/ __| | Apache Interface to OpenSSL + * | | | | | | (_) | (_| | \__ \__ \ | + * |_| |_| |_|\___/ \__,_|___|___/___/_| + * |_____| + * ssl_scache_shmcb.c + * Session Cache via Shared Memory (Cyclic Buffer Variant) + */ + +#include "mod_ssl.h" + +/* + * This shared memory based SSL session cache implementation was + * originally written by Geoff Thorpe <geoff@geoffthorpe.net> for C2Net + * Europe as a contribution to Ralf Engelschall's mod_ssl project. + */ + +/* + * The shared-memory segment header can be cast to and from the + * SHMCBHeader type, all other structures need to be initialised by + * utility functions. + * + * The "header" looks like this; + * + * data applying to the overall structure: + * - division_offset (unsigned int): + * how far into the shared memory segment the first division is. + * - division_size (unsigned int): + * how many bytes each division occupies. + * (NB: This includes the queue and the cache) + * - division_mask (unsigned char): + * the "mask" in the next line. Add one to this, + * and that's the number of divisions. + * + * data applying to within each division: + * - queue_size (unsigned int): + * how big each "queue" is. NB: The queue is the first block in each + * division and is followed immediately by the cache itself so so + * there's no cache_offset value. + * + * data applying to within each queue: + * - index_num (unsigned char): + * how many indexes in each cache's queue + * - index_offset (unsigned char): + * how far into the queue the first index is. + * - index_size: + * how big each index is. + * + * data applying to within each cache: + * - cache_data_offset (unsigned int): + * how far into the cache the session-data array is stored. + * - cache_data_size (unsigned int): + * how big each cache's data block is. + * + * statistics data (this will eventually be per-division but right now + * there's only one mutex): + * - stores (unsigned long): + * how many stores have been performed in the cache. + * - expiries (unsigned long): + * how many session have been expired from the cache. + * - scrolled (unsigned long): + * how many sessions have been scrolled out of full cache during a + * "store" operation. This is different to the "removes" stats as + * they are requested by mod_ssl/Apache, these are done because of + * cache logistics. (NB: Also, this value should be deducible from + * the others if my code has no bugs, but I count it anyway - plus + * it helps debugging :-). + * - retrieves_hit (unsigned long): + * how many session-retrieves have succeeded. + * - retrieves_miss (unsigned long): + * how many session-retrieves have failed. + * - removes_hit (unsigned long): + * - removes_miss (unsigned long): + * + * Following immediately after the header is an array of "divisions". + * Each division is simply a "queue" immediately followed by its + * corresponding "cache". Each division handles some pre-defined band + * of sessions by using the "division_mask" in the header. Eg. if + * division_mask=0x1f then there are 32 divisions, the first of which + * will store sessions whose least-significant 5 bits are 0, the second + * stores session whose LS 5 bits equal 1, etc. A queue is an indexing + * structure referring to its corresponding cache. + * + * A "queue" looks like this; + * + * - first_pos (unsigned int): + * the location within the array of indexes where the virtual + * "left-hand-edge" of the cyclic buffer is. + * - pos_count (unsigned int): + * the number of indexes occupied from first_pos onwards. + * + * ...followed by an array of indexes, each of which can be + * memcpy'd to and from an SHMCBIndex, and look like this; + * + * - expires (time_t): + * the time() value at which this session expires. + * - offset (unsigned int): + * the offset within the cache data block where the corresponding + * session is stored. + * - s_id2 (unsigned char): + * the second byte of the session_id, stored as an optimisation to + * reduce the number of d2i_SSL_SESSION calls that are made when doing + * a lookup. + * - removed (unsigned char): + * a byte used to indicate whether a session has been "passively" + * removed. Ie. it is still in the cache but is to be disregarded by + * any "retrieve" operation. + * + * A "cache" looks like this; + * + * - first_pos (unsigned int): + * the location within the data block where the virtual + * "left-hand-edge" of the cyclic buffer is. + * - pos_count (unsigned int): + * the number of bytes used in the data block from first_pos onwards. + * + * ...followed by the data block in which actual DER-encoded SSL + * sessions are stored. + */ + +/* + * Header - can be memcpy'd to and from the front of the shared + * memory segment. NB: The first copy (commented out) has the + * elements in a meaningful order, but due to data-alignment + * braindeadness, the second (uncommented) copy has the types grouped + * so as to decrease "struct-bloat". sigh. + */ +typedef struct { + unsigned long num_stores; + unsigned long num_expiries; + unsigned long num_scrolled; + unsigned long num_retrieves_hit; + unsigned long num_retrieves_miss; + unsigned long num_removes_hit; + unsigned long num_removes_miss; + unsigned int division_offset; + unsigned int division_size; + unsigned int queue_size; + unsigned int cache_data_offset; + unsigned int cache_data_size; + unsigned char division_mask; + unsigned int index_num; + unsigned int index_offset; + unsigned int index_size; +} SHMCBHeader; + +/* + * Index - can be memcpy'd to and from an index inside each + * queue's index array. + */ +typedef struct { + time_t expires; + unsigned int offset; + unsigned char s_id2; + unsigned char removed; +} SHMCBIndex; + +/* + * Queue - must be populated by a call to shmcb_get_division + * and the structure's pointers are used for updating (ie. + * the structure doesn't need any "set" to update values). + */ +typedef struct { + SHMCBHeader *header; + unsigned int *first_pos; + unsigned int *pos_count; + SHMCBIndex *indexes; +} SHMCBQueue; + +/* + * Cache - same comment as for Queue. 'Queue's are in a 1-1 + * correspondance with 'Cache's and are usually carried round + * in a pair, they are only seperated for clarity. + */ +typedef struct { + SHMCBHeader *header; + unsigned int *first_pos; + unsigned int *pos_count; + unsigned char *data; +} SHMCBCache; + +/* + * Forward function prototypes. + */ + +/* Functions for working around data-alignment-picky systems (sparcs, + Irix, etc). These use "memcpy" as a way of foxing these systems into + treating the composite types as byte-arrays rather than higher-level + primitives that it prefers to have 4-(or 8-)byte aligned. I don't + envisage this being a performance issue as a couple of 2 or 4 byte + memcpys can hardly make a dent on the massive memmove operations this + cache technique avoids, nor the overheads of ASN en/decoding. */ +static unsigned int shmcb_get_safe_uint(unsigned int *); +static void shmcb_set_safe_uint_ex(unsigned char *, const unsigned char *); +#define shmcb_set_safe_uint(pdest, src) \ + do { \ + unsigned int tmp_uint = src; \ + shmcb_set_safe_uint_ex((unsigned char *)pdest, \ + (const unsigned char *)(&tmp_uint)); \ + } while(0) +#if 0 /* Unused so far */ +static unsigned long shmcb_get_safe_ulong(unsigned long *); +static void shmcb_set_safe_ulong_ex(unsigned char *, const unsigned char *); +#define shmcb_set_safe_ulong(pdest, src) \ + do { \ + unsigned long tmp_ulong = src; \ + shmcb_set_safe_ulong_ex((unsigned char *)pdest, \ + (const unsigned char *)(&tmp_ulong)); \ + } while(0) +#endif +static time_t shmcb_get_safe_time(time_t *); +static void shmcb_set_safe_time_ex(unsigned char *, const unsigned char *); +#define shmcb_set_safe_time(pdest, src) \ + do { \ + time_t tmp_time = src; \ + shmcb_set_safe_time_ex((unsigned char *)pdest, \ + (const unsigned char *)(&tmp_time)); \ + } while(0) + +/* This is necessary simply so that the size passed to memset() is not a + * compile-time constant, preventing the compiler from optimising it. */ +static void shmcb_safe_clear(void *ptr, size_t size) +{ + memset(ptr, 0, size); +} + +/* Underlying functions for session-caching */ +static BOOL shmcb_init_memory(server_rec *, void *, unsigned int); +static BOOL shmcb_store_session(server_rec *, void *, UCHAR *, int, SSL_SESSION *, time_t); +static SSL_SESSION *shmcb_retrieve_session(server_rec *, void *, UCHAR *, int); +static BOOL shmcb_remove_session(server_rec *, void *, UCHAR *, int); + +/* Utility functions for manipulating the structures */ +static void shmcb_get_header(void *, SHMCBHeader **); +static BOOL shmcb_get_division(SHMCBHeader *, SHMCBQueue *, SHMCBCache *, unsigned int); +static SHMCBIndex *shmcb_get_index(const SHMCBQueue *, unsigned int); +static unsigned int shmcb_expire_division(server_rec *, SHMCBQueue *, SHMCBCache *); +static BOOL shmcb_insert_encoded_session(server_rec *, SHMCBQueue *, SHMCBCache *, unsigned char *, unsigned int, unsigned char *, time_t); +static SSL_SESSION *shmcb_lookup_session_id(server_rec *, SHMCBQueue *, SHMCBCache *, UCHAR *, unsigned int); +static BOOL shmcb_remove_session_id(server_rec *, SHMCBQueue *, SHMCBCache *, UCHAR *, unsigned int); + +/* + * Data-alignment functions (a.k.a. avoidance tactics) + * + * NB: On HPUX (and possibly others) there is a *very* mischievous little + * "optimisation" in the compilers where it will convert the following; + * memcpy(dest_ptr, &source, sizeof(unsigned int)); + * (where dest_ptr is of type (unsigned int *) and source is (unsigned int)) + * into; + * *dest_ptr = source; (or *dest_ptr = *(&source), not sure). + * Either way, it completely destroys the whole point of these _safe_ + * functions, because the assignment operation will fall victim to the + * architecture's byte-alignment dictations, whereas the memcpy (as a + * byte-by-byte copy) should not. sigh. So, if you're wondering about the + * apparently unnecessary conversions to (unsigned char *) in these + * functions, you now have an explanation. Don't just revert them back and + * say "ooh look, it still works" - if you try it on HPUX (well, 32-bit + * HPUX 11.00 at least) you may find it fails with a SIGBUS. :-( + */ + +static unsigned int shmcb_get_safe_uint(unsigned int *ptr) +{ + unsigned int ret; + shmcb_set_safe_uint_ex((unsigned char *)(&ret), + (const unsigned char *)ptr); + return ret; +} + +static void shmcb_set_safe_uint_ex(unsigned char *dest, + const unsigned char *src) +{ + memcpy(dest, src, sizeof(unsigned int)); +} + +#if 0 /* Unused so far */ +static unsigned long shmcb_get_safe_ulong(unsigned long *ptr) +{ + unsigned long ret; + shmcb_set_safe_ulong_ex((unsigned char *)(&ret), + (const unsigned char *)ptr); + return ret; +} + +static void shmcb_set_safe_ulong_ex(unsigned char *dest, + const unsigned char *src) +{ + memcpy(dest, src, sizeof(unsigned long)); +} +#endif + +static time_t shmcb_get_safe_time(time_t * ptr) +{ + time_t ret; + shmcb_set_safe_time_ex((unsigned char *)(&ret), + (const unsigned char *)ptr); + return ret; +} + +static void shmcb_set_safe_time_ex(unsigned char *dest, + const unsigned char *src) +{ + memcpy(dest, src, sizeof(time_t)); +} +/* +** +** High-Level "handlers" as per ssl_scache.c +** +*/ + +void ssl_scache_shmcb_init(server_rec *s, apr_pool_t *p) +{ + SSLModConfigRec *mc = myModConfig(s); + void *shm_segment; + apr_size_t shm_segsize; + apr_status_t rv; + + /* + * Create shared memory segment + */ + if (mc->szSessionCacheDataFile == NULL) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "SSLSessionCache required"); + ssl_die(); + } + + /* Use anonymous shm by default, fall back on name-based. */ + rv = apr_shm_create(&(mc->pSessionCacheDataMM), + mc->nSessionCacheDataSize, + NULL, mc->pPool); + + if (APR_STATUS_IS_ENOTIMPL(rv)) { + rv = apr_shm_create(&(mc->pSessionCacheDataMM), + mc->nSessionCacheDataSize, + mc->szSessionCacheDataFile, + mc->pPool); + } + + if (rv != APR_SUCCESS) { + char buf[100]; + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "Cannot allocate shared memory: (%d)%s", rv, + apr_strerror(rv, buf, sizeof(buf))); + ssl_die(); + } + shm_segment = apr_shm_baseaddr_get(mc->pSessionCacheDataMM); + shm_segsize = apr_shm_size_get(mc->pSessionCacheDataMM); + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "shmcb_init allocated %" APR_SIZE_T_FMT + " bytes of shared memory", + shm_segsize); + if (!shmcb_init_memory(s, shm_segment, shm_segsize)) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "Failure initialising 'shmcb' shared memory"); + ssl_die(); + } + ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, + "Shared memory session cache initialised"); + + /* + * Success ... we hack the memory block into place by cheating for + * now and stealing a member variable the original shared memory + * cache was using. :-) + */ + mc->tSessionCacheDataTable = (table_t *) shm_segment; + return; +} + +void ssl_scache_shmcb_kill(server_rec *s) +{ + SSLModConfigRec *mc = myModConfig(s); + + if (mc->pSessionCacheDataMM != NULL) { + apr_shm_destroy(mc->pSessionCacheDataMM); + mc->pSessionCacheDataMM = NULL; + } + return; +} + +BOOL ssl_scache_shmcb_store(server_rec *s, UCHAR *id, int idlen, + time_t timeout, SSL_SESSION * pSession) +{ + SSLModConfigRec *mc = myModConfig(s); + void *shm_segment; + BOOL to_return = FALSE; + + /* We've kludged our pointer into the other cache's member variable. */ + shm_segment = (void *) mc->tSessionCacheDataTable; + ssl_mutex_on(s); + if (!shmcb_store_session(s, shm_segment, id, idlen, pSession, timeout)) + /* in this cache engine, "stores" should never fail. */ + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "'shmcb' code was unable to store a " + "session in the cache."); + else { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "shmcb_store successful"); + to_return = TRUE; + } + ssl_mutex_off(s); + return to_return; +} + +SSL_SESSION *ssl_scache_shmcb_retrieve(server_rec *s, UCHAR *id, int idlen) +{ + SSLModConfigRec *mc = myModConfig(s); + void *shm_segment; + SSL_SESSION *pSession; + + /* We've kludged our pointer into the other cache's member variable. */ + shm_segment = (void *) mc->tSessionCacheDataTable; + ssl_mutex_on(s); + pSession = shmcb_retrieve_session(s, shm_segment, id, idlen); + ssl_mutex_off(s); + if (pSession) + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "shmcb_retrieve had a hit"); + else { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "shmcb_retrieve had a miss"); + ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, + "Client requested a 'session-resume' but " + "we have no such session."); + } + return pSession; +} + +void ssl_scache_shmcb_remove(server_rec *s, UCHAR *id, int idlen) +{ + SSLModConfigRec *mc = myModConfig(s); + void *shm_segment; + + /* We've kludged our pointer into the other cache's member variable. */ + shm_segment = (void *) mc->tSessionCacheDataTable; + ssl_mutex_on(s); + shmcb_remove_session(s, shm_segment, id, idlen); + ssl_mutex_off(s); +} + +void ssl_scache_shmcb_expire(server_rec *s) +{ + /* NOP */ + return; +} + +void ssl_scache_shmcb_status(server_rec *s, apr_pool_t *p, + void (*func) (char *, void *), void *arg) +{ + SSLModConfigRec *mc = myModConfig(s); + SHMCBHeader *header; + SHMCBQueue queue; + SHMCBCache cache; + SHMCBIndex *idx; + void *shm_segment; + unsigned int loop, total, cache_total, non_empty_divisions; + int index_pct, cache_pct; + double expiry_total; + time_t average_expiry, now, max_expiry, min_expiry, idxexpiry; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "inside ssl_scache_shmcb_status"); + + /* We've kludged our pointer into the other cache's member variable. */ + shm_segment = (void *) mc->tSessionCacheDataTable; + + /* Get the header structure. */ + shmcb_get_header(shm_segment, &header); + total = cache_total = non_empty_divisions = 0; + average_expiry = max_expiry = min_expiry = 0; + expiry_total = 0; + + /* It may seem strange to grab "now" at this point, but in theory + * we should never have a negative threshold but grabbing "now" after + * the loop (which performs expiries) could allow that chance. */ + now = time(NULL); + for (loop = 0; loop <= header->division_mask; loop++) { + if (shmcb_get_division(header, &queue, &cache, loop)) { + shmcb_expire_division(s, &queue, &cache); + total += shmcb_get_safe_uint(queue.pos_count); + cache_total += shmcb_get_safe_uint(cache.pos_count); + if (shmcb_get_safe_uint(queue.pos_count) > 0) { + idx = shmcb_get_index(&queue, + shmcb_get_safe_uint(queue.first_pos)); + non_empty_divisions++; + idxexpiry = shmcb_get_safe_time(&(idx->expires)); + expiry_total += (double) idxexpiry; + max_expiry = (idxexpiry > max_expiry ? idxexpiry : + max_expiry); + if (min_expiry == 0) + min_expiry = idxexpiry; + else + min_expiry = (idxexpiry < min_expiry ? idxexpiry : + min_expiry); + } + } + } + index_pct = (100 * total) / (header->index_num * (header->division_mask + 1)); + cache_pct = (100 * cache_total) / (header->cache_data_size * (header->division_mask + 1)); + func(apr_psprintf(p, "cache type: <b>SHMCB</b>, shared memory: <b>%d</b> " + "bytes, current sessions: <b>%d</b><br>", + mc->nSessionCacheDataSize, total), arg); + func(apr_psprintf(p, "sub-caches: <b>%d</b>, indexes per sub-cache: " + "<b>%d</b><br>", (int) header->division_mask + 1, + (int) header->index_num), arg); + if (non_empty_divisions != 0) { + average_expiry = (time_t)(expiry_total / (double)non_empty_divisions); + func(apr_psprintf(p, "time left on oldest entries' SSL sessions: "), arg); + if (now < average_expiry) + func(apr_psprintf(p, "avg: <b>%d</b> seconds, (range: %d...%d)<br>", + (int)(average_expiry - now), (int) (min_expiry - now), + (int)(max_expiry - now)), arg); + else + func(apr_psprintf(p, "expiry threshold: <b>Calculation Error!</b>" + "<br>"), arg); + + } + func(apr_psprintf(p, "index usage: <b>%d%%</b>, cache usage: <b>%d%%</b>" + "<br>", index_pct, cache_pct), arg); + func(apr_psprintf(p, "total sessions stored since starting: <b>%lu</b><br>", + header->num_stores), arg); + func(apr_psprintf(p,"total sessions expired since starting: <b>%lu</b><br>", + header->num_expiries), arg); + func(apr_psprintf(p, "total (pre-expiry) sessions scrolled out of the " + "cache: <b>%lu</b><br>", header->num_scrolled), arg); + func(apr_psprintf(p, "total retrieves since starting: <b>%lu</b> hit, " + "<b>%lu</b> miss<br>", header->num_retrieves_hit, + header->num_retrieves_miss), arg); + func(apr_psprintf(p, "total removes since starting: <b>%lu</b> hit, " + "<b>%lu</b> miss<br>", header->num_removes_hit, + header->num_removes_miss), arg); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving shmcb_status"); + return; +} + +/* +** +** Memory manipulation and low-level cache operations +** +*/ + +static BOOL shmcb_init_memory( + server_rec *s, void *shm_mem, + unsigned int shm_mem_size) +{ + SHMCBHeader *header; + SHMCBQueue queue; + SHMCBCache cache; + unsigned int temp, loop, granularity; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "entered shmcb_init_memory()"); + + /* Calculate some sizes... */ + temp = sizeof(SHMCBHeader); + + /* If the segment is ridiculously too small, bail out */ + if (shm_mem_size < (2*temp)) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shared memory segment too small"); + return FALSE; + } + + /* Make temp the amount of memory without the header */ + temp = shm_mem_size - temp; + + /* Work on the basis that you need 10 bytes index for each session + * (approx 150 bytes), which is to divide temp by 160 - and then + * make sure we err on having too index space to burn even when + * the cache is full, which is a lot less stupid than having + * having not enough index space to utilise the whole cache!. */ + temp /= 120; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "for %u bytes, recommending %u indexes", + shm_mem_size, temp); + + /* We should divide these indexes evenly amongst the queues. Try + * to get it so that there are roughly half the number of divisions + * as there are indexes in each division. */ + granularity = 256; + while ((temp / granularity) < (2 * granularity)) + granularity /= 2; + + /* So we have 'granularity' divisions, set 'temp' equal to the + * number of indexes in each division. */ + temp /= granularity; + + /* Too small? Bail ... */ + if (temp < 5) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shared memory segment too small"); + return FALSE; + } + + /* OK, we're sorted - from here on in, the return should be TRUE */ + header = (SHMCBHeader *)shm_mem; + header->division_mask = (unsigned char)(granularity - 1); + header->division_offset = sizeof(SHMCBHeader); + header->index_num = temp; + header->index_offset = (2 * sizeof(unsigned int)); + header->index_size = sizeof(SHMCBIndex); + header->queue_size = header->index_offset + + (header->index_num * header->index_size); + + /* Now calculate the space for each division */ + temp = shm_mem_size - header->division_offset; + header->division_size = temp / granularity; + + /* Calculate the space left in each division for the cache */ + temp -= header->queue_size; + header->cache_data_offset = (2 * sizeof(unsigned int)); + header->cache_data_size = header->division_size - + header->queue_size - header->cache_data_offset; + + /* Output trace info */ + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "shmcb_init_memory choices follow"); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "division_mask = 0x%02X", header->division_mask); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "division_offset = %u", header->division_offset); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "division_size = %u", header->division_size); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "queue_size = %u", header->queue_size); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "index_num = %u", header->index_num); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "index_offset = %u", header->index_offset); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "index_size = %u", header->index_size); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "cache_data_offset = %u", header->cache_data_offset); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "cache_data_size = %u", header->cache_data_size); + + /* The header is done, make the caches empty */ + for (loop = 0; loop < granularity; loop++) { + if (!shmcb_get_division(header, &queue, &cache, loop)) + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "shmcb_init_memory, " "internal error"); + shmcb_set_safe_uint(cache.first_pos, 0); + shmcb_set_safe_uint(cache.pos_count, 0); + shmcb_set_safe_uint(queue.first_pos, 0); + shmcb_set_safe_uint(queue.pos_count, 0); + } + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving shmcb_init_memory()"); + return TRUE; +} + +static BOOL shmcb_store_session( + server_rec *s, void *shm_segment, UCHAR *id, + int idlen, SSL_SESSION * pSession, + time_t timeout) +{ + SHMCBHeader *header; + SHMCBQueue queue; + SHMCBCache cache; + unsigned char masked_index; + unsigned char encoded[SSL_SESSION_MAX_DER]; + unsigned char *ptr_encoded; + unsigned int len_encoded; + time_t expiry_time; + unsigned char *session_id = SSL_SESSION_get_session_id(pSession); + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "inside shmcb_store_session"); + + /* Get the header structure, which division this session will fall into etc. */ + shmcb_get_header(shm_segment, &header); + masked_index = session_id[0] & header->division_mask; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "session_id[0]=%u, masked index=%u", + session_id[0], masked_index); + if (!shmcb_get_division(header, &queue, &cache, (unsigned int)masked_index)) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shmcb_store_session internal error"); + return FALSE; + } + + /* Serialise the session, work out how much we're dealing + * with. NB: This check could be removed if we're not paranoid + * or we find some assurance that it will never be necessary. */ + len_encoded = i2d_SSL_SESSION(pSession, NULL); + if (len_encoded > SSL_SESSION_MAX_DER) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "session is too big (%u bytes)", len_encoded); + return FALSE; + } + ptr_encoded = encoded; + len_encoded = i2d_SSL_SESSION(pSession, &ptr_encoded); + expiry_time = timeout; + if (!shmcb_insert_encoded_session(s, &queue, &cache, encoded, + len_encoded, session_id, + expiry_time)) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "can't store a session!"); + return FALSE; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving shmcb_store successfully"); + header->num_stores++; + return TRUE; +} + +static SSL_SESSION *shmcb_retrieve_session( + server_rec *s, void *shm_segment, + UCHAR *id, int idlen) +{ + SHMCBHeader *header; + SHMCBQueue queue; + SHMCBCache cache; + unsigned char masked_index; + SSL_SESSION *pSession; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "inside shmcb_retrieve_session"); + if (idlen < 2) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "unusably short session_id provided " + "(%u bytes)", idlen); + return FALSE; + } + + /* Get the header structure, which division this session lookup + * will come from etc. */ + shmcb_get_header(shm_segment, &header); + masked_index = id[0] & header->division_mask; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "id[0]=%u, masked index=%u", id[0], masked_index); + if (!shmcb_get_division(header, &queue, &cache, (unsigned int) masked_index)) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shmcb_retrieve_session internal error"); + header->num_retrieves_miss++; + return FALSE; + } + + /* Get the session corresponding to the session_id or NULL if it + * doesn't exist (or is flagged as "removed"). */ + pSession = shmcb_lookup_session_id(s, &queue, &cache, id, idlen); + if (pSession) + header->num_retrieves_hit++; + else + header->num_retrieves_miss++; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving shmcb_retrieve_session"); + return pSession; +} + +static BOOL shmcb_remove_session( + server_rec *s, void *shm_segment, + UCHAR *id, int idlen) +{ + SHMCBHeader *header; + SHMCBQueue queue; + SHMCBCache cache; + unsigned char masked_index; + BOOL res; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "inside shmcb_remove_session"); + if (id == NULL) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "remove called with NULL session_id!"); + return FALSE; + } + + /* Get the header structure, which division this session remove + * will happen in etc. */ + shmcb_get_header(shm_segment, &header); + masked_index = id[0] & header->division_mask; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "id[0]=%u, masked index=%u", id[0], masked_index); + if (!shmcb_get_division(header, &queue, &cache, (unsigned int)masked_index)) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "shmcb_remove_session, internal error"); + header->num_removes_miss++; + return FALSE; + } + res = shmcb_remove_session_id(s, &queue, &cache, id, idlen); + if (res) + header->num_removes_hit++; + else + header->num_removes_miss++; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving shmcb_remove_session"); + return res; +} + + +/* +** +** Weirdo cyclic buffer functions +** +*/ + +/* This gets used in the cyclic "index array" (in the 'Queue's) and + * in the cyclic 'Cache's too ... you provide the "width" of the + * cyclic store, the starting position and how far to move (with + * wrapping if necessary). Basically it's addition modulo buf_size. */ +static unsigned int shmcb_cyclic_increment( + unsigned int buf_size, + unsigned int start_pos, + unsigned int to_add) +{ + start_pos += to_add; + while (start_pos >= buf_size) + start_pos -= buf_size; + return start_pos; +} + +/* Given two positions in a cyclic buffer, calculate the "distance". + * This is to cover the case ("non-trivial") where the 'next' offset + * is to the left of the 'start' offset. NB: This calculates the + * space inclusive of one end-point but not the other. There is an + * ambiguous case (which is why we use the <start_pos,offset> + * coordinate system rather than <start_pos,end_pos> one) when 'start' + * is the same as 'next'. It could indicate the buffer is full or it + * can indicate the buffer is empty ... I choose the latter as it's + * easier and usually necessary to check if the buffer is full anyway + * before doing incremental logic (which is this useful for), but we + * definitely need the empty case handled - in fact it's our starting + * state!! */ +static unsigned int shmcb_cyclic_space( + unsigned int buf_size, + unsigned int start_offset, + unsigned int next_offset) +{ + /* Is it the trivial case? */ + if (start_offset <= next_offset) + return (next_offset - start_offset); /* yes */ + else + return ((buf_size - start_offset) + next_offset); /* no */ +} + +/* A "normal-to-cyclic" memcpy ... this takes a linear block of + * memory and copies it onto a cyclic buffer. The purpose and + * function of this is pretty obvious, you need to cover the case + * that the destination (cyclic) buffer has to wrap round. */ +static void shmcb_cyclic_ntoc_memcpy( + unsigned int buf_size, + unsigned char *data, + unsigned int dest_offset, + unsigned char *src, unsigned int src_len) +{ + /* Cover the case that src_len > buf_size */ + if (src_len > buf_size) + src_len = buf_size; + + /* Can it be copied all in one go? */ + if (dest_offset + src_len < buf_size) + /* yes */ + memcpy(data + dest_offset, src, src_len); + else { + /* no */ + memcpy(data + dest_offset, src, buf_size - dest_offset); + memcpy(data, src + buf_size - dest_offset, + src_len + dest_offset - buf_size); + } + return; +} + +/* A "cyclic-to-normal" memcpy ... given the last function, this + * one's purpose is clear, it copies out of a cyclic buffer handling + * wrapping. */ +static void shmcb_cyclic_cton_memcpy( + unsigned int buf_size, + unsigned char *dest, + unsigned char *data, + unsigned int src_offset, + unsigned int src_len) +{ + /* Cover the case that src_len > buf_size */ + if (src_len > buf_size) + src_len = buf_size; + + /* Can it be copied all in one go? */ + if (src_offset + src_len < buf_size) + /* yes */ + memcpy(dest, data + src_offset, src_len); + else { + /* no */ + memcpy(dest, data + src_offset, buf_size - src_offset); + memcpy(dest + buf_size - src_offset, data, + src_len + src_offset - buf_size); + } + return; +} + +/* Here's the cool hack that makes it all work ... by simply + * making the first collection of bytes *be* our header structure + * (casting it into the C structure), we have the perfect way to + * maintain state in a shared-memory session cache from one call + * (and process) to the next, use the shared memory itself! The + * original mod_ssl shared-memory session cache uses variables + * inside the context, but we simply use that for storing the + * pointer to the shared memory itself. And don't forget, after + * Apache's initialisation, this "header" is constant/read-only + * so we can read it outside any locking. + * <grin> - sometimes I just *love* coding y'know?! */ +static void shmcb_get_header(void *shm_mem, SHMCBHeader **header) +{ + *header = (SHMCBHeader *)shm_mem; + return; +} + +/* This is what populates our "interesting" structures. Given a + * pointer to the header, and an index into the appropriate + * division (this must have already been masked using the + * division_mask by the caller!), we can populate the provided + * SHMCBQueue and SHMCBCache structures with values and + * pointers to the underlying shared memory. Upon returning + * (if not FALSE), the caller can meddle with the pointer + * values and they will map into the shared-memory directly, + * as such there's no need to "free" or "set" the Queue or + * Cache values, they were themselves references to the *real* + * data. */ +static BOOL shmcb_get_division( + SHMCBHeader *header, SHMCBQueue *queue, + SHMCBCache *cache, unsigned int idx) +{ + unsigned char *pQueue; + unsigned char *pCache; + + /* bounds check */ + if (idx > (unsigned int) header->division_mask) + return FALSE; + + /* Locate the blocks of memory storing the corresponding data */ + pQueue = ((unsigned char *) header) + header->division_offset + + (idx * header->division_size); + pCache = pQueue + header->queue_size; + + /* Populate the structures with appropriate pointers */ + queue->first_pos = (unsigned int *) pQueue; + + /* Our structures stay packed, no matter what the system's + * data-alignment regime is. */ + queue->pos_count = (unsigned int *) (pQueue + sizeof(unsigned int)); + queue->indexes = (SHMCBIndex *) (pQueue + (2 * sizeof(unsigned int))); + cache->first_pos = (unsigned int *) pCache; + cache->pos_count = (unsigned int *) (pCache + sizeof(unsigned int)); + cache->data = (unsigned char *) (pCache + (2 * sizeof(unsigned int))); + queue->header = cache->header = header; + + return TRUE; +} + +/* This returns a pointer to the piece of shared memory containing + * a specified 'Index'. SHMCBIndex, like SHMCBHeader, is a fixed + * width non-referencing structure of primitive types that can be + * cast onto the corresponding block of shared memory. Thus, by + * returning a cast pointer to that section of shared memory, the + * caller can read and write values to and from the "structure" and + * they are actually reading and writing the underlying shared + * memory. */ +static SHMCBIndex *shmcb_get_index( + const SHMCBQueue *queue, unsigned int idx) +{ + /* bounds check */ + if (idx > queue->header->index_num) + return NULL; + + /* Return a pointer to the index. NB: I am being horribly pendantic + * here so as to avoid any potential data-alignment assumptions being + * placed on the pointer arithmetic by the compiler (sigh). */ + return (SHMCBIndex *)(((unsigned char *) queue->indexes) + + (idx * sizeof(SHMCBIndex))); +} + +/* This functions rolls expired cache (and index) entries off the front + * of the cyclic buffers in a division. The function returns the number + * of expired sessions. */ +static unsigned int shmcb_expire_division( + server_rec *s, SHMCBQueue *queue, SHMCBCache *cache) +{ + SHMCBIndex *idx; + time_t now; + unsigned int loop, index_num, pos_count, new_pos; + SHMCBHeader *header; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "entering shmcb_expire_division"); + + /* We must calculate num and space ourselves based on expiry times. */ + now = time(NULL); + loop = 0; + new_pos = shmcb_get_safe_uint(queue->first_pos); + + /* Cache useful values */ + header = queue->header; + index_num = header->index_num; + pos_count = shmcb_get_safe_uint(queue->pos_count); + while (loop < pos_count) { + idx = shmcb_get_index(queue, new_pos); + if (shmcb_get_safe_time(&(idx->expires)) > now) + /* it hasn't expired yet, we're done iterating */ + break; + /* This one should be expired too. Shift to the next entry. */ + loop++; + new_pos = shmcb_cyclic_increment(index_num, new_pos, 1); + } + + /* Find the new_offset and make the expiries happen. */ + if (loop > 0) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "will be expiring %u sessions", loop); + /* We calculate the new_offset by "peeking" (or in the + * case it's the last entry, "sneaking" ;-). */ + if (loop == pos_count) { + /* We are expiring everything! This is easy to do... */ + shmcb_set_safe_uint(queue->pos_count, 0); + shmcb_set_safe_uint(cache->pos_count, 0); + } + else { + /* The Queue is easy to adjust */ + shmcb_set_safe_uint(queue->pos_count, + shmcb_get_safe_uint(queue->pos_count) - loop); + shmcb_set_safe_uint(queue->first_pos, new_pos); + /* peek to the start of the next session */ + idx = shmcb_get_index(queue, new_pos); + /* We can use shmcb_cyclic_space because we've guaranteed + * we don't fit the ambiguous full/empty case. */ + shmcb_set_safe_uint(cache->pos_count, + shmcb_get_safe_uint(cache->pos_count) - + shmcb_cyclic_space(header->cache_data_size, + shmcb_get_safe_uint(cache->first_pos), + shmcb_get_safe_uint(&(idx->offset)))); + shmcb_set_safe_uint(cache->first_pos, shmcb_get_safe_uint(&(idx->offset))); + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "we now have %u sessions", + shmcb_get_safe_uint(queue->pos_count)); + } + header->num_expiries += loop; + return loop; +} + +/* Inserts a new encoded session into a queue/cache pair - expiring + * (early or otherwise) any leading sessions as necessary to ensure + * there is room. An error return (FALSE) should only happen in the + * event of surreal values being passed on, or ridiculously small + * cache sizes. NB: For tracing purposes, this function is also given + * the server_rec to allow "ssl_log()". */ +static BOOL shmcb_insert_encoded_session( + server_rec *s, SHMCBQueue * queue, + SHMCBCache * cache, + unsigned char *encoded, + unsigned int encoded_len, + unsigned char *session_id, + time_t expiry_time) +{ + SHMCBHeader *header; + SHMCBIndex *idx = NULL; + unsigned int gap, new_pos, loop, new_offset; + int need; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "entering shmcb_insert_encoded_session, " + "*queue->pos_count = %u", + shmcb_get_safe_uint(queue->pos_count)); + + /* If there's entries to expire, ditch them first thing. */ + shmcb_expire_division(s, queue, cache); + header = cache->header; + gap = header->cache_data_size - shmcb_get_safe_uint(cache->pos_count); + if (gap < encoded_len) { + new_pos = shmcb_get_safe_uint(queue->first_pos); + loop = 0; + need = (int) encoded_len - (int) gap; + while ((need > 0) && (loop + 1 < shmcb_get_safe_uint(queue->pos_count))) { + new_pos = shmcb_cyclic_increment(header->index_num, new_pos, 1); + loop += 1; + idx = shmcb_get_index(queue, new_pos); + need = (int) encoded_len - (int) gap - + shmcb_cyclic_space(header->cache_data_size, + shmcb_get_safe_uint(cache->first_pos), + shmcb_get_safe_uint(&(idx->offset))); + } + if (loop > 0) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "about to scroll %u sessions from %u", + loop, shmcb_get_safe_uint(queue->pos_count)); + /* We are removing "loop" items from the cache. */ + shmcb_set_safe_uint(cache->pos_count, + shmcb_get_safe_uint(cache->pos_count) - + shmcb_cyclic_space(header->cache_data_size, + shmcb_get_safe_uint(cache->first_pos), + shmcb_get_safe_uint(&(idx->offset)))); + shmcb_set_safe_uint(cache->first_pos, shmcb_get_safe_uint(&(idx->offset))); + shmcb_set_safe_uint(queue->pos_count, shmcb_get_safe_uint(queue->pos_count) - loop); + shmcb_set_safe_uint(queue->first_pos, new_pos); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "now only have %u sessions", + shmcb_get_safe_uint(queue->pos_count)); + /* Update the stats!!! */ + header->num_scrolled += loop; + } + } + + /* probably unecessary checks, but I'll leave them until this code + * is verified. */ + if (shmcb_get_safe_uint(cache->pos_count) + encoded_len > + header->cache_data_size) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shmcb_insert_encoded_session internal error"); + return FALSE; + } + if (shmcb_get_safe_uint(queue->pos_count) == header->index_num) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shmcb_insert_encoded_session internal error"); + return FALSE; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "we have %u bytes and %u indexes free - enough", + header->cache_data_size - + shmcb_get_safe_uint(cache->pos_count), header->index_num - + shmcb_get_safe_uint(queue->pos_count)); + + + /* HERE WE ASSUME THAT THE NEW SESSION SHOULD GO ON THE END! I'M NOT + * CHECKING WHETHER IT SHOULD BE GENUINELY "INSERTED" SOMEWHERE. + * + * We either fix that, or find out at a "higher" (read "mod_ssl") + * level whether it is possible to have distinct session caches for + * any attempted tomfoolery to do with different session timeouts. + * Knowing in advance that we can have a cache-wide constant timeout + * would make this stuff *MUCH* more efficient. Mind you, it's very + * efficient right now because I'm ignoring this problem!!! + */ + + /* Increment to the first unused byte */ + new_offset = shmcb_cyclic_increment(header->cache_data_size, + shmcb_get_safe_uint(cache->first_pos), + shmcb_get_safe_uint(cache->pos_count)); + /* Copy the DER-encoded session into place */ + shmcb_cyclic_ntoc_memcpy(header->cache_data_size, cache->data, + new_offset, encoded, encoded_len); + /* Get the new index that this session is stored in. */ + new_pos = shmcb_cyclic_increment(header->index_num, + shmcb_get_safe_uint(queue->first_pos), + shmcb_get_safe_uint(queue->pos_count)); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "storing in index %u, at offset %u", + new_pos, new_offset); + idx = shmcb_get_index(queue, new_pos); + if (idx == NULL) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shmcb_insert_encoded_session internal error"); + return FALSE; + } + shmcb_safe_clear(idx, sizeof(SHMCBIndex)); + shmcb_set_safe_time(&(idx->expires), expiry_time); + shmcb_set_safe_uint(&(idx->offset), new_offset); + + /* idx->removed = (unsigned char)0; */ /* Not needed given the memset above. */ + idx->s_id2 = session_id[1]; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "session_id[0]=%u, idx->s_id2=%u", + session_id[0], session_id[1]); + + /* All that remains is to adjust the cache's and queue's "pos_count"s. */ + shmcb_set_safe_uint(cache->pos_count, + shmcb_get_safe_uint(cache->pos_count) + encoded_len); + shmcb_set_safe_uint(queue->pos_count, + shmcb_get_safe_uint(queue->pos_count) + 1); + + /* And just for good debugging measure ... */ + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving now with %u bytes in the cache and %u indexes", + shmcb_get_safe_uint(cache->pos_count), + shmcb_get_safe_uint(queue->pos_count)); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving shmcb_insert_encoded_session"); + return TRUE; +} + +/* Performs a lookup into a queue/cache pair for a + * session_id. If found, the session is deserialised + * and returned, otherwise NULL. */ +static SSL_SESSION *shmcb_lookup_session_id( + server_rec *s, SHMCBQueue *queue, + SHMCBCache *cache, UCHAR *id, + unsigned int idlen) +{ + unsigned char tempasn[SSL_SESSION_MAX_DER]; + SHMCBIndex *idx; + SHMCBHeader *header; + SSL_SESSION *pSession = NULL; + unsigned int curr_pos, loop, count; + MODSSL_D2I_SSL_SESSION_CONST unsigned char *ptr; + time_t now; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "entering shmcb_lookup_session_id"); + + /* If there are entries to expire, ditch them first thing. */ + shmcb_expire_division(s, queue, cache); + now = time(NULL); + curr_pos = shmcb_get_safe_uint(queue->first_pos); + count = shmcb_get_safe_uint(queue->pos_count); + header = queue->header; + for (loop = 0; loop < count; loop++) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "loop=%u, count=%u, curr_pos=%u", + loop, count, curr_pos); + idx = shmcb_get_index(queue, curr_pos); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "idx->s_id2=%u, id[1]=%u, offset=%u", + idx->s_id2, id[1], shmcb_get_safe_uint(&(idx->offset))); + /* Only look into the session further if; + * (a) the second byte of the session_id matches, + * (b) the "removed" flag isn't set, + * (c) the session hasn't expired yet. + * We do (c) like this so that it saves us having to + * do natural expiries ... naturally expired sessions + * scroll off the front anyway when the cache is full and + * "rotating", the only real issue that remains is the + * removal or disabling of forcibly killed sessions. */ + if ((idx->s_id2 == id[1]) && !idx->removed && + (shmcb_get_safe_time(&(idx->expires)) > now)) { + unsigned int session_id_length; + unsigned char *session_id; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "at index %u, found possible session match", + curr_pos); + shmcb_cyclic_cton_memcpy(header->cache_data_size, + tempasn, cache->data, + shmcb_get_safe_uint(&(idx->offset)), + SSL_SESSION_MAX_DER); + ptr = tempasn; + pSession = d2i_SSL_SESSION(NULL, &ptr, SSL_SESSION_MAX_DER); + session_id_length = SSL_SESSION_get_session_id_length(pSession); + session_id = SSL_SESSION_get_session_id(pSession); + + if (pSession == NULL) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "scach2_lookup_session_id internal error"); + return NULL; + } + if ((session_id_length == idlen) && + (memcmp(session_id, id, idlen) == 0)) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "a match!"); + return pSession; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "not a match"); + SSL_SESSION_free(pSession); + pSession = NULL; + } + curr_pos = shmcb_cyclic_increment(header->index_num, curr_pos, 1); + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "no matching sessions were found"); + return NULL; +} + +static BOOL shmcb_remove_session_id( + server_rec *s, SHMCBQueue *queue, + SHMCBCache *cache, UCHAR *id, unsigned int idlen) +{ + unsigned char tempasn[SSL_SESSION_MAX_DER]; + SSL_SESSION *pSession = NULL; + SHMCBIndex *idx; + SHMCBHeader *header; + unsigned int curr_pos, loop, count; + MODSSL_D2I_SSL_SESSION_CONST unsigned char *ptr; + BOOL to_return = FALSE; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "entering shmcb_remove_session_id"); + + /* If there's entries to expire, ditch them first thing. */ + /* shmcb_expire_division(s, queue, cache); */ + + /* Regarding the above ... hmmm ... I know my expiry code is slightly + * "faster" than all this remove stuff ... but if the higher level + * code calls a "remove" operation (and this *only* seems to happen + * when it has spotted an expired session before we had a chance to) + * then it should get credit for a remove (stats-wise). Also, in the + * off-chance that the server *requests* a renegotiate and wants to + * wipe the session clean we should give that priority over our own + * routine expiry handling. So I've moved the expiry check to *after* + * this general remove stuff. */ + curr_pos = shmcb_get_safe_uint(queue->first_pos); + count = shmcb_get_safe_uint(queue->pos_count); + header = cache->header; + for (loop = 0; loop < count; loop++) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "loop=%u, count=%u, curr_pos=%u", + loop, count, curr_pos); + idx = shmcb_get_index(queue, curr_pos); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "idx->s_id2=%u, id[1]=%u", idx->s_id2, + id[1]); + /* Only look into the session further if the second byte of the + * session_id matches. */ + if (idx->s_id2 == id[1]) { + unsigned int session_id_length; + unsigned char *session_id; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "at index %u, found possible " + "session match", curr_pos); + shmcb_cyclic_cton_memcpy(header->cache_data_size, + tempasn, cache->data, + shmcb_get_safe_uint(&(idx->offset)), + SSL_SESSION_MAX_DER); + ptr = tempasn; + pSession = d2i_SSL_SESSION(NULL, &ptr, SSL_SESSION_MAX_DER); + if (pSession == NULL) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, + "shmcb_remove_session_id, internal error"); + goto end; + } + session_id_length = SSL_SESSION_get_session_id_length(pSession); + session_id = SSL_SESSION_get_session_id(pSession); + + if ((session_id_length == idlen) + && (memcmp(id, session_id, idlen) == 0)) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "a match!"); + /* Scrub out this session "quietly" */ + idx->removed = (unsigned char) 1; + SSL_SESSION_free(pSession); + to_return = TRUE; + goto end; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "not a match"); + SSL_SESSION_free(pSession); + pSession = NULL; + } + curr_pos = shmcb_cyclic_increment(header->index_num, curr_pos, 1); + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "no matching sessions were found"); + + /* If there's entries to expire, ditch them now. */ + shmcb_expire_division(s, queue, cache); +end: + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, + "leaving shmcb_remove_session_id"); + return to_return; +} |