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authorRajithaY <rajithax.yerrumsetty@intel.com>2017-04-25 03:31:15 -0700
committerRajitha Yerrumchetty <rajithax.yerrumsetty@intel.com>2017-05-22 06:48:08 +0000
commitbb756eebdac6fd24e8919e2c43f7d2c8c4091f59 (patch)
treeca11e03542edf2d8f631efeca5e1626d211107e3 /qemu/roms/ipxe/src/net/tcp.c
parenta14b48d18a9ed03ec191cf16b162206998a895ce (diff)
Adding qemu as a submodule of KVMFORNFV
This Patch includes the changes to add qemu as a submodule to kvmfornfv repo and make use of the updated latest qemu for the execution of all testcase Change-Id: I1280af507a857675c7f81d30c95255635667bdd7 Signed-off-by:RajithaY<rajithax.yerrumsetty@intel.com>
Diffstat (limited to 'qemu/roms/ipxe/src/net/tcp.c')
-rw-r--r--qemu/roms/ipxe/src/net/tcp.c1687
1 files changed, 0 insertions, 1687 deletions
diff --git a/qemu/roms/ipxe/src/net/tcp.c b/qemu/roms/ipxe/src/net/tcp.c
deleted file mode 100644
index c69c83b85..000000000
--- a/qemu/roms/ipxe/src/net/tcp.c
+++ /dev/null
@@ -1,1687 +0,0 @@
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <assert.h>
-#include <errno.h>
-#include <byteswap.h>
-#include <ipxe/timer.h>
-#include <ipxe/iobuf.h>
-#include <ipxe/malloc.h>
-#include <ipxe/init.h>
-#include <ipxe/retry.h>
-#include <ipxe/refcnt.h>
-#include <ipxe/pending.h>
-#include <ipxe/xfer.h>
-#include <ipxe/open.h>
-#include <ipxe/uri.h>
-#include <ipxe/netdevice.h>
-#include <ipxe/profile.h>
-#include <ipxe/process.h>
-#include <ipxe/tcpip.h>
-#include <ipxe/tcp.h>
-
-/** @file
- *
- * TCP protocol
- *
- */
-
-FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
-/** A TCP connection */
-struct tcp_connection {
- /** Reference counter */
- struct refcnt refcnt;
- /** List of TCP connections */
- struct list_head list;
-
- /** Flags */
- unsigned int flags;
-
- /** Data transfer interface */
- struct interface xfer;
-
- /** Remote socket address */
- struct sockaddr_tcpip peer;
- /** Local port */
- unsigned int local_port;
- /** Maximum segment size */
- size_t mss;
-
- /** Current TCP state */
- unsigned int tcp_state;
- /** Previous TCP state
- *
- * Maintained only for debug messages
- */
- unsigned int prev_tcp_state;
- /** Current sequence number
- *
- * Equivalent to SND.UNA in RFC 793 terminology.
- */
- uint32_t snd_seq;
- /** Unacknowledged sequence count
- *
- * Equivalent to (SND.NXT-SND.UNA) in RFC 793 terminology.
- */
- uint32_t snd_sent;
- /** Send window
- *
- * Equivalent to SND.WND in RFC 793 terminology
- */
- uint32_t snd_win;
- /** Current acknowledgement number
- *
- * Equivalent to RCV.NXT in RFC 793 terminology.
- */
- uint32_t rcv_ack;
- /** Receive window
- *
- * Equivalent to RCV.WND in RFC 793 terminology.
- */
- uint32_t rcv_win;
- /** Received timestamp value
- *
- * Updated when a packet is received; copied to ts_recent when
- * the window is advanced.
- */
- uint32_t ts_val;
- /** Most recent received timestamp that advanced the window
- *
- * Equivalent to TS.Recent in RFC 1323 terminology.
- */
- uint32_t ts_recent;
- /** Send window scale
- *
- * Equivalent to Snd.Wind.Scale in RFC 1323 terminology
- */
- uint8_t snd_win_scale;
- /** Receive window scale
- *
- * Equivalent to Rcv.Wind.Scale in RFC 1323 terminology
- */
- uint8_t rcv_win_scale;
-
- /** Selective acknowledgement list (in host-endian order) */
- struct tcp_sack_block sack[TCP_SACK_MAX];
-
- /** Transmit queue */
- struct list_head tx_queue;
- /** Receive queue */
- struct list_head rx_queue;
- /** Transmission process */
- struct process process;
- /** Retransmission timer */
- struct retry_timer timer;
- /** Shutdown (TIME_WAIT) timer */
- struct retry_timer wait;
-
- /** Pending operations for SYN and FIN */
- struct pending_operation pending_flags;
- /** Pending operations for transmit queue */
- struct pending_operation pending_data;
-};
-
-/** TCP flags */
-enum tcp_flags {
- /** TCP data transfer interface has been closed */
- TCP_XFER_CLOSED = 0x0001,
- /** TCP timestamps are enabled */
- TCP_TS_ENABLED = 0x0002,
- /** TCP acknowledgement is pending */
- TCP_ACK_PENDING = 0x0004,
- /** TCP selective acknowledgement is enabled */
- TCP_SACK_ENABLED = 0x0008,
-};
-
-/** TCP internal header
- *
- * This is the header that replaces the TCP header for packets
- * enqueued on the receive queue.
- */
-struct tcp_rx_queued_header {
- /** SEQ value, in host-endian order
- *
- * This represents the SEQ value at the time the packet is
- * enqueued, and so excludes the SYN, if present.
- */
- uint32_t seq;
- /** Next SEQ value, in host-endian order */
- uint32_t nxt;
- /** Flags
- *
- * Only FIN is valid within this flags byte; all other flags
- * have already been processed by the time the packet is
- * enqueued.
- */
- uint8_t flags;
- /** Reserved */
- uint8_t reserved[3];
-};
-
-/**
- * List of registered TCP connections
- */
-static LIST_HEAD ( tcp_conns );
-
-/** Transmit profiler */
-static struct profiler tcp_tx_profiler __profiler = { .name = "tcp.tx" };
-
-/** Receive profiler */
-static struct profiler tcp_rx_profiler __profiler = { .name = "tcp.rx" };
-
-/** Data transfer profiler */
-static struct profiler tcp_xfer_profiler __profiler = { .name = "tcp.xfer" };
-
-/* Forward declarations */
-static struct process_descriptor tcp_process_desc;
-static struct interface_descriptor tcp_xfer_desc;
-static void tcp_expired ( struct retry_timer *timer, int over );
-static void tcp_wait_expired ( struct retry_timer *timer, int over );
-static struct tcp_connection * tcp_demux ( unsigned int local_port );
-static int tcp_rx_ack ( struct tcp_connection *tcp, uint32_t ack,
- uint32_t win );
-
-/**
- * Name TCP state
- *
- * @v state TCP state
- * @ret name Name of TCP state
- */
-static inline __attribute__ (( always_inline )) const char *
-tcp_state ( int state ) {
- switch ( state ) {
- case TCP_CLOSED: return "CLOSED";
- case TCP_LISTEN: return "LISTEN";
- case TCP_SYN_SENT: return "SYN_SENT";
- case TCP_SYN_RCVD: return "SYN_RCVD";
- case TCP_ESTABLISHED: return "ESTABLISHED";
- case TCP_FIN_WAIT_1: return "FIN_WAIT_1";
- case TCP_FIN_WAIT_2: return "FIN_WAIT_2";
- case TCP_CLOSING_OR_LAST_ACK: return "CLOSING/LAST_ACK";
- case TCP_TIME_WAIT: return "TIME_WAIT";
- case TCP_CLOSE_WAIT: return "CLOSE_WAIT";
- default: return "INVALID";
- }
-}
-
-/**
- * Dump TCP state transition
- *
- * @v tcp TCP connection
- */
-static inline __attribute__ (( always_inline )) void
-tcp_dump_state ( struct tcp_connection *tcp ) {
-
- if ( tcp->tcp_state != tcp->prev_tcp_state ) {
- DBGC ( tcp, "TCP %p transitioned from %s to %s\n", tcp,
- tcp_state ( tcp->prev_tcp_state ),
- tcp_state ( tcp->tcp_state ) );
- }
- tcp->prev_tcp_state = tcp->tcp_state;
-}
-
-/**
- * Dump TCP flags
- *
- * @v flags TCP flags
- */
-static inline __attribute__ (( always_inline )) void
-tcp_dump_flags ( struct tcp_connection *tcp, unsigned int flags ) {
- if ( flags & TCP_RST )
- DBGC2 ( tcp, " RST" );
- if ( flags & TCP_SYN )
- DBGC2 ( tcp, " SYN" );
- if ( flags & TCP_PSH )
- DBGC2 ( tcp, " PSH" );
- if ( flags & TCP_FIN )
- DBGC2 ( tcp, " FIN" );
- if ( flags & TCP_ACK )
- DBGC2 ( tcp, " ACK" );
-}
-
-/***************************************************************************
- *
- * Open and close
- *
- ***************************************************************************
- */
-
-/**
- * Check if local TCP port is available
- *
- * @v port Local port number
- * @ret port Local port number, or negative error
- */
-static int tcp_port_available ( int port ) {
-
- return ( tcp_demux ( port ) ? -EADDRINUSE : port );
-}
-
-/**
- * Open a TCP connection
- *
- * @v xfer Data transfer interface
- * @v peer Peer socket address
- * @v local Local socket address, or NULL
- * @ret rc Return status code
- */
-static int tcp_open ( struct interface *xfer, struct sockaddr *peer,
- struct sockaddr *local ) {
- struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
- struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
- struct tcp_connection *tcp;
- size_t mtu;
- int port;
- int rc;
-
- /* Allocate and initialise structure */
- tcp = zalloc ( sizeof ( *tcp ) );
- if ( ! tcp )
- return -ENOMEM;
- DBGC ( tcp, "TCP %p allocated\n", tcp );
- ref_init ( &tcp->refcnt, NULL );
- intf_init ( &tcp->xfer, &tcp_xfer_desc, &tcp->refcnt );
- process_init_stopped ( &tcp->process, &tcp_process_desc, &tcp->refcnt );
- timer_init ( &tcp->timer, tcp_expired, &tcp->refcnt );
- timer_init ( &tcp->wait, tcp_wait_expired, &tcp->refcnt );
- tcp->prev_tcp_state = TCP_CLOSED;
- tcp->tcp_state = TCP_STATE_SENT ( TCP_SYN );
- tcp_dump_state ( tcp );
- tcp->snd_seq = random();
- INIT_LIST_HEAD ( &tcp->tx_queue );
- INIT_LIST_HEAD ( &tcp->rx_queue );
- memcpy ( &tcp->peer, st_peer, sizeof ( tcp->peer ) );
-
- /* Calculate MSS */
- mtu = tcpip_mtu ( &tcp->peer );
- if ( ! mtu ) {
- DBGC ( tcp, "TCP %p has no route to %s\n",
- tcp, sock_ntoa ( peer ) );
- rc = -ENETUNREACH;
- goto err;
- }
- tcp->mss = ( mtu - sizeof ( struct tcp_header ) );
-
- /* Bind to local port */
- port = tcpip_bind ( st_local, tcp_port_available );
- if ( port < 0 ) {
- rc = port;
- DBGC ( tcp, "TCP %p could not bind: %s\n",
- tcp, strerror ( rc ) );
- goto err;
- }
- tcp->local_port = port;
- DBGC ( tcp, "TCP %p bound to port %d\n", tcp, tcp->local_port );
-
- /* Start timer to initiate SYN */
- start_timer_nodelay ( &tcp->timer );
-
- /* Add a pending operation for the SYN */
- pending_get ( &tcp->pending_flags );
-
- /* Attach parent interface, transfer reference to connection
- * list and return
- */
- intf_plug_plug ( &tcp->xfer, xfer );
- list_add ( &tcp->list, &tcp_conns );
- return 0;
-
- err:
- ref_put ( &tcp->refcnt );
- return rc;
-}
-
-/**
- * Close TCP connection
- *
- * @v tcp TCP connection
- * @v rc Reason for close
- *
- * Closes the data transfer interface. If the TCP state machine is in
- * a suitable state, the connection will be deleted.
- */
-static void tcp_close ( struct tcp_connection *tcp, int rc ) {
- struct io_buffer *iobuf;
- struct io_buffer *tmp;
-
- /* Close data transfer interface */
- intf_shutdown ( &tcp->xfer, rc );
- tcp->flags |= TCP_XFER_CLOSED;
-
- /* If we are in CLOSED, or have otherwise not yet received a
- * SYN (i.e. we are in LISTEN or SYN_SENT), just delete the
- * connection.
- */
- if ( ! ( tcp->tcp_state & TCP_STATE_RCVD ( TCP_SYN ) ) ) {
-
- /* Transition to CLOSED for the sake of debugging messages */
- tcp->tcp_state = TCP_CLOSED;
- tcp_dump_state ( tcp );
-
- /* Free any unprocessed I/O buffers */
- list_for_each_entry_safe ( iobuf, tmp, &tcp->rx_queue, list ) {
- list_del ( &iobuf->list );
- free_iob ( iobuf );
- }
-
- /* Free any unsent I/O buffers */
- list_for_each_entry_safe ( iobuf, tmp, &tcp->tx_queue, list ) {
- list_del ( &iobuf->list );
- free_iob ( iobuf );
- pending_put ( &tcp->pending_data );
- }
- assert ( ! is_pending ( &tcp->pending_data ) );
-
- /* Remove pending operations for SYN and FIN, if applicable */
- pending_put ( &tcp->pending_flags );
- pending_put ( &tcp->pending_flags );
-
- /* Remove from list and drop reference */
- process_del ( &tcp->process );
- stop_timer ( &tcp->timer );
- stop_timer ( &tcp->wait );
- list_del ( &tcp->list );
- ref_put ( &tcp->refcnt );
- DBGC ( tcp, "TCP %p connection deleted\n", tcp );
- return;
- }
-
- /* If we have not had our SYN acknowledged (i.e. we are in
- * SYN_RCVD), pretend that it has been acknowledged so that we
- * can send a FIN without breaking things.
- */
- if ( ! ( tcp->tcp_state & TCP_STATE_ACKED ( TCP_SYN ) ) )
- tcp_rx_ack ( tcp, ( tcp->snd_seq + 1 ), 0 );
-
- /* If we have no data remaining to send, start sending FIN */
- if ( list_empty ( &tcp->tx_queue ) &&
- ! ( tcp->tcp_state & TCP_STATE_SENT ( TCP_FIN ) ) ) {
-
- tcp->tcp_state |= TCP_STATE_SENT ( TCP_FIN );
- tcp_dump_state ( tcp );
- process_add ( &tcp->process );
-
- /* Add a pending operation for the FIN */
- pending_get ( &tcp->pending_flags );
- }
-}
-
-/***************************************************************************
- *
- * Transmit data path
- *
- ***************************************************************************
- */
-
-/**
- * Calculate transmission window
- *
- * @v tcp TCP connection
- * @ret len Maximum length that can be sent in a single packet
- */
-static size_t tcp_xmit_win ( struct tcp_connection *tcp ) {
- size_t len;
-
- /* Not ready if we're not in a suitable connection state */
- if ( ! TCP_CAN_SEND_DATA ( tcp->tcp_state ) )
- return 0;
-
- /* Length is the minimum of the receiver's window and the path MTU */
- len = tcp->snd_win;
- if ( len > TCP_PATH_MTU )
- len = TCP_PATH_MTU;
-
- return len;
-}
-
-/**
- * Check data-transfer flow control window
- *
- * @v tcp TCP connection
- * @ret len Length of window
- */
-static size_t tcp_xfer_window ( struct tcp_connection *tcp ) {
-
- /* Not ready if data queue is non-empty. This imposes a limit
- * of only one unACKed packet in the TX queue at any time; we
- * do this to conserve memory usage.
- */
- if ( ! list_empty ( &tcp->tx_queue ) )
- return 0;
-
- /* Return TCP window length */
- return tcp_xmit_win ( tcp );
-}
-
-/**
- * Find selective acknowledgement block
- *
- * @v tcp TCP connection
- * @v seq SEQ value in SACK block (in host-endian order)
- * @v sack SACK block to fill in (in host-endian order)
- * @ret len Length of SACK block
- */
-static uint32_t tcp_sack_block ( struct tcp_connection *tcp, uint32_t seq,
- struct tcp_sack_block *sack ) {
- struct io_buffer *iobuf;
- struct tcp_rx_queued_header *tcpqhdr;
- uint32_t left = tcp->rcv_ack;
- uint32_t right = left;
-
- /* Find highest block which does not start after SEQ */
- list_for_each_entry ( iobuf, &tcp->rx_queue, list ) {
- tcpqhdr = iobuf->data;
- if ( tcp_cmp ( tcpqhdr->seq, right ) > 0 ) {
- if ( tcp_cmp ( tcpqhdr->seq, seq ) > 0 )
- break;
- left = tcpqhdr->seq;
- }
- if ( tcp_cmp ( tcpqhdr->nxt, right ) > 0 )
- right = tcpqhdr->nxt;
- }
-
- /* Fail if this block does not contain SEQ */
- if ( tcp_cmp ( right, seq ) < 0 )
- return 0;
-
- /* Populate SACK block */
- sack->left = left;
- sack->right = right;
- return ( right - left );
-}
-
-/**
- * Update TCP selective acknowledgement list
- *
- * @v tcp TCP connection
- * @v seq SEQ value in first SACK block (in host-endian order)
- * @ret count Number of SACK blocks
- */
-static unsigned int tcp_sack ( struct tcp_connection *tcp, uint32_t seq ) {
- struct tcp_sack_block sack[TCP_SACK_MAX];
- unsigned int old = 0;
- unsigned int new = 0;
- unsigned int i;
- uint32_t len;
-
- /* Populate first new SACK block */
- len = tcp_sack_block ( tcp, seq, &sack[0] );
- if ( len )
- new++;
-
- /* Populate remaining new SACK blocks based on old SACK blocks */
- for ( old = 0 ; old < TCP_SACK_MAX ; old++ ) {
-
- /* Stop if we run out of space in the new list */
- if ( new == TCP_SACK_MAX )
- break;
-
- /* Skip empty old SACK blocks */
- if ( tcp->sack[old].left == tcp->sack[old].right )
- continue;
-
- /* Populate new SACK block */
- len = tcp_sack_block ( tcp, tcp->sack[old].left, &sack[new] );
- if ( len == 0 )
- continue;
-
- /* Eliminate duplicates */
- for ( i = 0 ; i < new ; i++ ) {
- if ( sack[i].left == sack[new].left ) {
- new--;
- break;
- }
- }
- new++;
- }
-
- /* Update SACK list */
- memset ( tcp->sack, 0, sizeof ( tcp->sack ) );
- memcpy ( tcp->sack, sack, ( new * sizeof ( tcp->sack[0] ) ) );
- return new;
-}
-
-/**
- * Process TCP transmit queue
- *
- * @v tcp TCP connection
- * @v max_len Maximum length to process
- * @v dest I/O buffer to fill with data, or NULL
- * @v remove Remove data from queue
- * @ret len Length of data processed
- *
- * This processes at most @c max_len bytes from the TCP connection's
- * transmit queue. Data will be copied into the @c dest I/O buffer
- * (if provided) and, if @c remove is true, removed from the transmit
- * queue.
- */
-static size_t tcp_process_tx_queue ( struct tcp_connection *tcp, size_t max_len,
- struct io_buffer *dest, int remove ) {
- struct io_buffer *iobuf;
- struct io_buffer *tmp;
- size_t frag_len;
- size_t len = 0;
-
- list_for_each_entry_safe ( iobuf, tmp, &tcp->tx_queue, list ) {
- frag_len = iob_len ( iobuf );
- if ( frag_len > max_len )
- frag_len = max_len;
- if ( dest ) {
- memcpy ( iob_put ( dest, frag_len ), iobuf->data,
- frag_len );
- }
- if ( remove ) {
- iob_pull ( iobuf, frag_len );
- if ( ! iob_len ( iobuf ) ) {
- list_del ( &iobuf->list );
- free_iob ( iobuf );
- pending_put ( &tcp->pending_data );
- }
- }
- len += frag_len;
- max_len -= frag_len;
- }
- return len;
-}
-
-/**
- * Transmit any outstanding data (with selective acknowledgement)
- *
- * @v tcp TCP connection
- * @v sack_seq SEQ for first selective acknowledgement (if any)
- *
- * Transmits any outstanding data on the connection.
- *
- * Note that even if an error is returned, the retransmission timer
- * will have been started if necessary, and so the stack will
- * eventually attempt to retransmit the failed packet.
- */
-static void tcp_xmit_sack ( struct tcp_connection *tcp, uint32_t sack_seq ) {
- struct io_buffer *iobuf;
- struct tcp_header *tcphdr;
- struct tcp_mss_option *mssopt;
- struct tcp_window_scale_padded_option *wsopt;
- struct tcp_timestamp_padded_option *tsopt;
- struct tcp_sack_permitted_padded_option *spopt;
- struct tcp_sack_padded_option *sackopt;
- struct tcp_sack_block *sack;
- void *payload;
- unsigned int flags;
- unsigned int sack_count;
- unsigned int i;
- size_t len = 0;
- size_t sack_len;
- uint32_t seq_len;
- uint32_t max_rcv_win;
- uint32_t max_representable_win;
- int rc;
-
- /* Start profiling */
- profile_start ( &tcp_tx_profiler );
-
- /* If retransmission timer is already running, do nothing */
- if ( timer_running ( &tcp->timer ) )
- return;
-
- /* Calculate both the actual (payload) and sequence space
- * lengths that we wish to transmit.
- */
- if ( TCP_CAN_SEND_DATA ( tcp->tcp_state ) ) {
- len = tcp_process_tx_queue ( tcp, tcp_xmit_win ( tcp ),
- NULL, 0 );
- }
- seq_len = len;
- flags = TCP_FLAGS_SENDING ( tcp->tcp_state );
- if ( flags & ( TCP_SYN | TCP_FIN ) ) {
- /* SYN or FIN consume one byte, and we can never send both */
- assert ( ! ( ( flags & TCP_SYN ) && ( flags & TCP_FIN ) ) );
- seq_len++;
- }
- tcp->snd_sent = seq_len;
-
- /* If we have nothing to transmit, stop now */
- if ( ( seq_len == 0 ) && ! ( tcp->flags & TCP_ACK_PENDING ) )
- return;
-
- /* If we are transmitting anything that requires
- * acknowledgement (i.e. consumes sequence space), start the
- * retransmission timer. Do this before attempting to
- * allocate the I/O buffer, in case allocation itself fails.
- */
- if ( seq_len )
- start_timer ( &tcp->timer );
-
- /* Allocate I/O buffer */
- iobuf = alloc_iob ( len + TCP_MAX_HEADER_LEN );
- if ( ! iobuf ) {
- DBGC ( tcp, "TCP %p could not allocate iobuf for %08x..%08x "
- "%08x\n", tcp, tcp->snd_seq, ( tcp->snd_seq + seq_len ),
- tcp->rcv_ack );
- return;
- }
- iob_reserve ( iobuf, TCP_MAX_HEADER_LEN );
-
- /* Fill data payload from transmit queue */
- tcp_process_tx_queue ( tcp, len, iobuf, 0 );
-
- /* Expand receive window if possible */
- max_rcv_win = xfer_window ( &tcp->xfer );
- if ( max_rcv_win > TCP_MAX_WINDOW_SIZE )
- max_rcv_win = TCP_MAX_WINDOW_SIZE;
- max_representable_win = ( 0xffff << tcp->rcv_win_scale );
- if ( max_rcv_win > max_representable_win )
- max_rcv_win = max_representable_win;
- max_rcv_win &= ~0x03; /* Keep everything dword-aligned */
- if ( tcp->rcv_win < max_rcv_win )
- tcp->rcv_win = max_rcv_win;
-
- /* Fill up the TCP header */
- payload = iobuf->data;
- if ( flags & TCP_SYN ) {
- mssopt = iob_push ( iobuf, sizeof ( *mssopt ) );
- mssopt->kind = TCP_OPTION_MSS;
- mssopt->length = sizeof ( *mssopt );
- mssopt->mss = htons ( tcp->mss );
- wsopt = iob_push ( iobuf, sizeof ( *wsopt ) );
- wsopt->nop = TCP_OPTION_NOP;
- wsopt->wsopt.kind = TCP_OPTION_WS;
- wsopt->wsopt.length = sizeof ( wsopt->wsopt );
- wsopt->wsopt.scale = TCP_RX_WINDOW_SCALE;
- spopt = iob_push ( iobuf, sizeof ( *spopt ) );
- memset ( spopt->nop, TCP_OPTION_NOP, sizeof ( spopt ) );
- spopt->spopt.kind = TCP_OPTION_SACK_PERMITTED;
- spopt->spopt.length = sizeof ( spopt->spopt );
- }
- if ( ( flags & TCP_SYN ) || ( tcp->flags & TCP_TS_ENABLED ) ) {
- tsopt = iob_push ( iobuf, sizeof ( *tsopt ) );
- memset ( tsopt->nop, TCP_OPTION_NOP, sizeof ( tsopt->nop ) );
- tsopt->tsopt.kind = TCP_OPTION_TS;
- tsopt->tsopt.length = sizeof ( tsopt->tsopt );
- tsopt->tsopt.tsval = htonl ( currticks() );
- tsopt->tsopt.tsecr = htonl ( tcp->ts_recent );
- }
- if ( ( tcp->flags & TCP_SACK_ENABLED ) &&
- ( ! list_empty ( &tcp->rx_queue ) ) &&
- ( ( sack_count = tcp_sack ( tcp, sack_seq ) ) != 0 ) ) {
- sack_len = ( sack_count * sizeof ( *sack ) );
- sackopt = iob_push ( iobuf, ( sizeof ( *sackopt ) + sack_len ));
- memset ( sackopt->nop, TCP_OPTION_NOP, sizeof ( sackopt->nop ));
- sackopt->sackopt.kind = TCP_OPTION_SACK;
- sackopt->sackopt.length =
- ( sizeof ( sackopt->sackopt ) + sack_len );
- sack = ( ( ( void * ) sackopt ) + sizeof ( *sackopt ) );
- for ( i = 0 ; i < sack_count ; i++, sack++ ) {
- sack->left = htonl ( tcp->sack[i].left );
- sack->right = htonl ( tcp->sack[i].right );
- }
- }
- if ( len != 0 )
- flags |= TCP_PSH;
- tcphdr = iob_push ( iobuf, sizeof ( *tcphdr ) );
- memset ( tcphdr, 0, sizeof ( *tcphdr ) );
- tcphdr->src = htons ( tcp->local_port );
- tcphdr->dest = tcp->peer.st_port;
- tcphdr->seq = htonl ( tcp->snd_seq );
- tcphdr->ack = htonl ( tcp->rcv_ack );
- tcphdr->hlen = ( ( payload - iobuf->data ) << 2 );
- tcphdr->flags = flags;
- tcphdr->win = htons ( tcp->rcv_win >> tcp->rcv_win_scale );
- tcphdr->csum = tcpip_chksum ( iobuf->data, iob_len ( iobuf ) );
-
- /* Dump header */
- DBGC2 ( tcp, "TCP %p TX %d->%d %08x..%08x %08x %4zd",
- tcp, ntohs ( tcphdr->src ), ntohs ( tcphdr->dest ),
- ntohl ( tcphdr->seq ), ( ntohl ( tcphdr->seq ) + seq_len ),
- ntohl ( tcphdr->ack ), len );
- tcp_dump_flags ( tcp, tcphdr->flags );
- DBGC2 ( tcp, "\n" );
-
- /* Transmit packet */
- if ( ( rc = tcpip_tx ( iobuf, &tcp_protocol, NULL, &tcp->peer, NULL,
- &tcphdr->csum ) ) != 0 ) {
- DBGC ( tcp, "TCP %p could not transmit %08x..%08x %08x: %s\n",
- tcp, tcp->snd_seq, ( tcp->snd_seq + tcp->snd_sent ),
- tcp->rcv_ack, strerror ( rc ) );
- return;
- }
-
- /* Clear ACK-pending flag */
- tcp->flags &= ~TCP_ACK_PENDING;
-
- profile_stop ( &tcp_tx_profiler );
-}
-
-/**
- * Transmit any outstanding data
- *
- * @v tcp TCP connection
- */
-static void tcp_xmit ( struct tcp_connection *tcp ) {
-
- /* Transmit without an explicit first SACK */
- tcp_xmit_sack ( tcp, tcp->rcv_ack );
-}
-
-/** TCP process descriptor */
-static struct process_descriptor tcp_process_desc =
- PROC_DESC_ONCE ( struct tcp_connection, process, tcp_xmit );
-
-/**
- * Retransmission timer expired
- *
- * @v timer Retransmission timer
- * @v over Failure indicator
- */
-static void tcp_expired ( struct retry_timer *timer, int over ) {
- struct tcp_connection *tcp =
- container_of ( timer, struct tcp_connection, timer );
-
- DBGC ( tcp, "TCP %p timer %s in %s for %08x..%08x %08x\n", tcp,
- ( over ? "expired" : "fired" ), tcp_state ( tcp->tcp_state ),
- tcp->snd_seq, ( tcp->snd_seq + tcp->snd_sent ), tcp->rcv_ack );
-
- assert ( ( tcp->tcp_state == TCP_SYN_SENT ) ||
- ( tcp->tcp_state == TCP_SYN_RCVD ) ||
- ( tcp->tcp_state == TCP_ESTABLISHED ) ||
- ( tcp->tcp_state == TCP_FIN_WAIT_1 ) ||
- ( tcp->tcp_state == TCP_CLOSE_WAIT ) ||
- ( tcp->tcp_state == TCP_CLOSING_OR_LAST_ACK ) );
-
- if ( over ) {
- /* If we have finally timed out and given up,
- * terminate the connection
- */
- tcp->tcp_state = TCP_CLOSED;
- tcp_dump_state ( tcp );
- tcp_close ( tcp, -ETIMEDOUT );
- } else {
- /* Otherwise, retransmit the packet */
- tcp_xmit ( tcp );
- }
-}
-
-/**
- * Shutdown timer expired
- *
- * @v timer Shutdown timer
- * @v over Failure indicator
- */
-static void tcp_wait_expired ( struct retry_timer *timer, int over __unused ) {
- struct tcp_connection *tcp =
- container_of ( timer, struct tcp_connection, wait );
-
- assert ( tcp->tcp_state == TCP_TIME_WAIT );
-
- DBGC ( tcp, "TCP %p wait complete in %s for %08x..%08x %08x\n", tcp,
- tcp_state ( tcp->tcp_state ), tcp->snd_seq,
- ( tcp->snd_seq + tcp->snd_sent ), tcp->rcv_ack );
-
- tcp->tcp_state = TCP_CLOSED;
- tcp_dump_state ( tcp );
- tcp_close ( tcp, 0 );
-}
-
-/**
- * Send RST response to incoming packet
- *
- * @v in_tcphdr TCP header of incoming packet
- * @ret rc Return status code
- */
-static int tcp_xmit_reset ( struct tcp_connection *tcp,
- struct sockaddr_tcpip *st_dest,
- struct tcp_header *in_tcphdr ) {
- struct io_buffer *iobuf;
- struct tcp_header *tcphdr;
- int rc;
-
- /* Allocate space for dataless TX buffer */
- iobuf = alloc_iob ( TCP_MAX_HEADER_LEN );
- if ( ! iobuf ) {
- DBGC ( tcp, "TCP %p could not allocate iobuf for RST "
- "%08x..%08x %08x\n", tcp, ntohl ( in_tcphdr->ack ),
- ntohl ( in_tcphdr->ack ), ntohl ( in_tcphdr->seq ) );
- return -ENOMEM;
- }
- iob_reserve ( iobuf, TCP_MAX_HEADER_LEN );
-
- /* Construct RST response */
- tcphdr = iob_push ( iobuf, sizeof ( *tcphdr ) );
- memset ( tcphdr, 0, sizeof ( *tcphdr ) );
- tcphdr->src = in_tcphdr->dest;
- tcphdr->dest = in_tcphdr->src;
- tcphdr->seq = in_tcphdr->ack;
- tcphdr->ack = in_tcphdr->seq;
- tcphdr->hlen = ( ( sizeof ( *tcphdr ) / 4 ) << 4 );
- tcphdr->flags = ( TCP_RST | TCP_ACK );
- tcphdr->win = htons ( 0 );
- tcphdr->csum = tcpip_chksum ( iobuf->data, iob_len ( iobuf ) );
-
- /* Dump header */
- DBGC2 ( tcp, "TCP %p TX %d->%d %08x..%08x %08x %4d",
- tcp, ntohs ( tcphdr->src ), ntohs ( tcphdr->dest ),
- ntohl ( tcphdr->seq ), ( ntohl ( tcphdr->seq ) ),
- ntohl ( tcphdr->ack ), 0 );
- tcp_dump_flags ( tcp, tcphdr->flags );
- DBGC2 ( tcp, "\n" );
-
- /* Transmit packet */
- if ( ( rc = tcpip_tx ( iobuf, &tcp_protocol, NULL, st_dest,
- NULL, &tcphdr->csum ) ) != 0 ) {
- DBGC ( tcp, "TCP %p could not transmit RST %08x..%08x %08x: "
- "%s\n", tcp, ntohl ( in_tcphdr->ack ),
- ntohl ( in_tcphdr->ack ), ntohl ( in_tcphdr->seq ),
- strerror ( rc ) );
- return rc;
- }
-
- return 0;
-}
-
-/***************************************************************************
- *
- * Receive data path
- *
- ***************************************************************************
- */
-
-/**
- * Identify TCP connection by local port number
- *
- * @v local_port Local port
- * @ret tcp TCP connection, or NULL
- */
-static struct tcp_connection * tcp_demux ( unsigned int local_port ) {
- struct tcp_connection *tcp;
-
- list_for_each_entry ( tcp, &tcp_conns, list ) {
- if ( tcp->local_port == local_port )
- return tcp;
- }
- return NULL;
-}
-
-/**
- * Parse TCP received options
- *
- * @v tcp TCP connection
- * @v data Raw options data
- * @v len Raw options length
- * @v options Options structure to fill in
- */
-static void tcp_rx_opts ( struct tcp_connection *tcp, const void *data,
- size_t len, struct tcp_options *options ) {
- const void *end = ( data + len );
- const struct tcp_option *option;
- unsigned int kind;
-
- memset ( options, 0, sizeof ( *options ) );
- while ( data < end ) {
- option = data;
- kind = option->kind;
- if ( kind == TCP_OPTION_END )
- return;
- if ( kind == TCP_OPTION_NOP ) {
- data++;
- continue;
- }
- switch ( kind ) {
- case TCP_OPTION_MSS:
- options->mssopt = data;
- break;
- case TCP_OPTION_WS:
- options->wsopt = data;
- break;
- case TCP_OPTION_SACK_PERMITTED:
- options->spopt = data;
- break;
- case TCP_OPTION_SACK:
- /* Ignore received SACKs */
- break;
- case TCP_OPTION_TS:
- options->tsopt = data;
- break;
- default:
- DBGC ( tcp, "TCP %p received unknown option %d\n",
- tcp, kind );
- break;
- }
- data += option->length;
- }
-}
-
-/**
- * Consume received sequence space
- *
- * @v tcp TCP connection
- * @v seq_len Sequence space length to consume
- */
-static void tcp_rx_seq ( struct tcp_connection *tcp, uint32_t seq_len ) {
- unsigned int sack;
-
- /* Sanity check */
- assert ( seq_len > 0 );
-
- /* Update acknowledgement number */
- tcp->rcv_ack += seq_len;
-
- /* Update window */
- if ( tcp->rcv_win > seq_len ) {
- tcp->rcv_win -= seq_len;
- } else {
- tcp->rcv_win = 0;
- }
-
- /* Update timestamp */
- tcp->ts_recent = tcp->ts_val;
-
- /* Update SACK list */
- for ( sack = 0 ; sack < TCP_SACK_MAX ; sack++ ) {
- if ( tcp->sack[sack].left == tcp->sack[sack].right )
- continue;
- if ( tcp_cmp ( tcp->sack[sack].left, tcp->rcv_ack ) < 0 )
- tcp->sack[sack].left = tcp->rcv_ack;
- if ( tcp_cmp ( tcp->sack[sack].right, tcp->rcv_ack ) < 0 )
- tcp->sack[sack].right = tcp->rcv_ack;
- }
-
- /* Mark ACK as pending */
- tcp->flags |= TCP_ACK_PENDING;
-}
-
-/**
- * Handle TCP received SYN
- *
- * @v tcp TCP connection
- * @v seq SEQ value (in host-endian order)
- * @v options TCP options
- * @ret rc Return status code
- */
-static int tcp_rx_syn ( struct tcp_connection *tcp, uint32_t seq,
- struct tcp_options *options ) {
-
- /* Synchronise sequence numbers on first SYN */
- if ( ! ( tcp->tcp_state & TCP_STATE_RCVD ( TCP_SYN ) ) ) {
- tcp->rcv_ack = seq;
- if ( options->tsopt )
- tcp->flags |= TCP_TS_ENABLED;
- if ( options->spopt )
- tcp->flags |= TCP_SACK_ENABLED;
- if ( options->wsopt ) {
- tcp->snd_win_scale = options->wsopt->scale;
- tcp->rcv_win_scale = TCP_RX_WINDOW_SCALE;
- }
- }
-
- /* Ignore duplicate SYN */
- if ( seq != tcp->rcv_ack )
- return 0;
-
- /* Acknowledge SYN */
- tcp_rx_seq ( tcp, 1 );
-
- /* Mark SYN as received and start sending ACKs with each packet */
- tcp->tcp_state |= ( TCP_STATE_SENT ( TCP_ACK ) |
- TCP_STATE_RCVD ( TCP_SYN ) );
-
- return 0;
-}
-
-/**
- * Handle TCP received ACK
- *
- * @v tcp TCP connection
- * @v ack ACK value (in host-endian order)
- * @v win WIN value (in host-endian order)
- * @ret rc Return status code
- */
-static int tcp_rx_ack ( struct tcp_connection *tcp, uint32_t ack,
- uint32_t win ) {
- uint32_t ack_len = ( ack - tcp->snd_seq );
- size_t len;
- unsigned int acked_flags;
-
- /* Check for out-of-range or old duplicate ACKs */
- if ( ack_len > tcp->snd_sent ) {
- DBGC ( tcp, "TCP %p received ACK for %08x..%08x, "
- "sent only %08x..%08x\n", tcp, tcp->snd_seq,
- ( tcp->snd_seq + ack_len ), tcp->snd_seq,
- ( tcp->snd_seq + tcp->snd_sent ) );
-
- if ( TCP_HAS_BEEN_ESTABLISHED ( tcp->tcp_state ) ) {
- /* Just ignore what might be old duplicate ACKs */
- return 0;
- } else {
- /* Send RST if an out-of-range ACK is received
- * on a not-yet-established connection, as per
- * RFC 793.
- */
- return -EINVAL;
- }
- }
-
- /* Update window size */
- tcp->snd_win = win;
-
- /* Ignore ACKs that don't actually acknowledge any new data.
- * (In particular, do not stop the retransmission timer; this
- * avoids creating a sorceror's apprentice syndrome when a
- * duplicate ACK is received and we still have data in our
- * transmit queue.)
- */
- if ( ack_len == 0 )
- return 0;
-
- /* Stop the retransmission timer */
- stop_timer ( &tcp->timer );
-
- /* Determine acknowledged flags and data length */
- len = ack_len;
- acked_flags = ( TCP_FLAGS_SENDING ( tcp->tcp_state ) &
- ( TCP_SYN | TCP_FIN ) );
- if ( acked_flags ) {
- len--;
- pending_put ( &tcp->pending_flags );
- }
-
- /* Update SEQ and sent counters */
- tcp->snd_seq = ack;
- tcp->snd_sent = 0;
-
- /* Remove any acknowledged data from transmit queue */
- tcp_process_tx_queue ( tcp, len, NULL, 1 );
-
- /* Mark SYN/FIN as acknowledged if applicable. */
- if ( acked_flags )
- tcp->tcp_state |= TCP_STATE_ACKED ( acked_flags );
-
- /* Start sending FIN if we've had all possible data ACKed */
- if ( list_empty ( &tcp->tx_queue ) &&
- ( tcp->flags & TCP_XFER_CLOSED ) &&
- ! ( tcp->tcp_state & TCP_STATE_SENT ( TCP_FIN ) ) ) {
- tcp->tcp_state |= TCP_STATE_SENT ( TCP_FIN );
- pending_get ( &tcp->pending_flags );
- }
-
- return 0;
-}
-
-/**
- * Handle TCP received data
- *
- * @v tcp TCP connection
- * @v seq SEQ value (in host-endian order)
- * @v iobuf I/O buffer
- * @ret rc Return status code
- *
- * This function takes ownership of the I/O buffer.
- */
-static int tcp_rx_data ( struct tcp_connection *tcp, uint32_t seq,
- struct io_buffer *iobuf ) {
- uint32_t already_rcvd;
- uint32_t len;
- int rc;
-
- /* Ignore duplicate or out-of-order data */
- already_rcvd = ( tcp->rcv_ack - seq );
- len = iob_len ( iobuf );
- if ( already_rcvd >= len ) {
- free_iob ( iobuf );
- return 0;
- }
- iob_pull ( iobuf, already_rcvd );
- len -= already_rcvd;
-
- /* Acknowledge new data */
- tcp_rx_seq ( tcp, len );
-
- /* Deliver data to application */
- profile_start ( &tcp_xfer_profiler );
- if ( ( rc = xfer_deliver_iob ( &tcp->xfer, iobuf ) ) != 0 ) {
- DBGC ( tcp, "TCP %p could not deliver %08x..%08x: %s\n",
- tcp, seq, ( seq + len ), strerror ( rc ) );
- return rc;
- }
- profile_stop ( &tcp_xfer_profiler );
-
- return 0;
-}
-
-/**
- * Handle TCP received FIN
- *
- * @v tcp TCP connection
- * @v seq SEQ value (in host-endian order)
- * @ret rc Return status code
- */
-static int tcp_rx_fin ( struct tcp_connection *tcp, uint32_t seq ) {
-
- /* Ignore duplicate or out-of-order FIN */
- if ( seq != tcp->rcv_ack )
- return 0;
-
- /* Acknowledge FIN */
- tcp_rx_seq ( tcp, 1 );
-
- /* Mark FIN as received */
- tcp->tcp_state |= TCP_STATE_RCVD ( TCP_FIN );
-
- /* Close connection */
- tcp_close ( tcp, 0 );
-
- return 0;
-}
-
-/**
- * Handle TCP received RST
- *
- * @v tcp TCP connection
- * @v seq SEQ value (in host-endian order)
- * @ret rc Return status code
- */
-static int tcp_rx_rst ( struct tcp_connection *tcp, uint32_t seq ) {
-
- /* Accept RST only if it falls within the window. If we have
- * not yet received a SYN, then we have no window to test
- * against, so fall back to checking that our SYN has been
- * ACKed.
- */
- if ( tcp->tcp_state & TCP_STATE_RCVD ( TCP_SYN ) ) {
- if ( ! tcp_in_window ( seq, tcp->rcv_ack, tcp->rcv_win ) )
- return 0;
- } else {
- if ( ! ( tcp->tcp_state & TCP_STATE_ACKED ( TCP_SYN ) ) )
- return 0;
- }
-
- /* Abort connection */
- tcp->tcp_state = TCP_CLOSED;
- tcp_dump_state ( tcp );
- tcp_close ( tcp, -ECONNRESET );
-
- DBGC ( tcp, "TCP %p connection reset by peer\n", tcp );
- return -ECONNRESET;
-}
-
-/**
- * Enqueue received TCP packet
- *
- * @v tcp TCP connection
- * @v seq SEQ value (in host-endian order)
- * @v flags TCP flags
- * @v iobuf I/O buffer
- */
-static void tcp_rx_enqueue ( struct tcp_connection *tcp, uint32_t seq,
- uint8_t flags, struct io_buffer *iobuf ) {
- struct tcp_rx_queued_header *tcpqhdr;
- struct io_buffer *queued;
- size_t len;
- uint32_t seq_len;
- uint32_t nxt;
-
- /* Calculate remaining flags and sequence length. Note that
- * SYN, if present, has already been processed by this point.
- */
- flags &= TCP_FIN;
- len = iob_len ( iobuf );
- seq_len = ( len + ( flags ? 1 : 0 ) );
- nxt = ( seq + seq_len );
-
- /* Discard immediately (to save memory) if:
- *
- * a) we have not yet received a SYN (and so have no defined
- * receive window), or
- * b) the packet lies entirely outside the receive window, or
- * c) there is no further content to process.
- */
- if ( ( ! ( tcp->tcp_state & TCP_STATE_RCVD ( TCP_SYN ) ) ) ||
- ( tcp_cmp ( seq, tcp->rcv_ack + tcp->rcv_win ) >= 0 ) ||
- ( tcp_cmp ( nxt, tcp->rcv_ack ) < 0 ) ||
- ( seq_len == 0 ) ) {
- free_iob ( iobuf );
- return;
- }
-
- /* Add internal header */
- tcpqhdr = iob_push ( iobuf, sizeof ( *tcpqhdr ) );
- tcpqhdr->seq = seq;
- tcpqhdr->nxt = nxt;
- tcpqhdr->flags = flags;
-
- /* Add to RX queue */
- list_for_each_entry ( queued, &tcp->rx_queue, list ) {
- tcpqhdr = queued->data;
- if ( tcp_cmp ( seq, tcpqhdr->seq ) < 0 )
- break;
- }
- list_add_tail ( &iobuf->list, &queued->list );
-}
-
-/**
- * Process receive queue
- *
- * @v tcp TCP connection
- */
-static void tcp_process_rx_queue ( struct tcp_connection *tcp ) {
- struct io_buffer *iobuf;
- struct tcp_rx_queued_header *tcpqhdr;
- uint32_t seq;
- unsigned int flags;
- size_t len;
-
- /* Process all applicable received buffers. Note that we
- * cannot use list_for_each_entry() to iterate over the RX
- * queue, since tcp_discard() may remove packets from the RX
- * queue while we are processing.
- */
- while ( ( iobuf = list_first_entry ( &tcp->rx_queue, struct io_buffer,
- list ) ) ) {
-
- /* Stop processing when we hit the first gap */
- tcpqhdr = iobuf->data;
- if ( tcp_cmp ( tcpqhdr->seq, tcp->rcv_ack ) > 0 )
- break;
-
- /* Strip internal header and remove from RX queue */
- list_del ( &iobuf->list );
- seq = tcpqhdr->seq;
- flags = tcpqhdr->flags;
- iob_pull ( iobuf, sizeof ( *tcpqhdr ) );
- len = iob_len ( iobuf );
-
- /* Handle new data, if any */
- tcp_rx_data ( tcp, seq, iob_disown ( iobuf ) );
- seq += len;
-
- /* Handle FIN, if present */
- if ( flags & TCP_FIN ) {
- tcp_rx_fin ( tcp, seq );
- seq++;
- }
- }
-}
-
-/**
- * Process received packet
- *
- * @v iobuf I/O buffer
- * @v netdev Network device
- * @v st_src Partially-filled source address
- * @v st_dest Partially-filled destination address
- * @v pshdr_csum Pseudo-header checksum
- * @ret rc Return status code
- */
-static int tcp_rx ( struct io_buffer *iobuf,
- struct net_device *netdev __unused,
- struct sockaddr_tcpip *st_src,
- struct sockaddr_tcpip *st_dest __unused,
- uint16_t pshdr_csum ) {
- struct tcp_header *tcphdr = iobuf->data;
- struct tcp_connection *tcp;
- struct tcp_options options;
- size_t hlen;
- uint16_t csum;
- uint32_t seq;
- uint32_t ack;
- uint16_t raw_win;
- uint32_t win;
- unsigned int flags;
- size_t len;
- uint32_t seq_len;
- size_t old_xfer_window;
- int rc;
-
- /* Start profiling */
- profile_start ( &tcp_rx_profiler );
-
- /* Sanity check packet */
- if ( iob_len ( iobuf ) < sizeof ( *tcphdr ) ) {
- DBG ( "TCP packet too short at %zd bytes (min %zd bytes)\n",
- iob_len ( iobuf ), sizeof ( *tcphdr ) );
- rc = -EINVAL;
- goto discard;
- }
- hlen = ( ( tcphdr->hlen & TCP_MASK_HLEN ) / 16 ) * 4;
- if ( hlen < sizeof ( *tcphdr ) ) {
- DBG ( "TCP header too short at %zd bytes (min %zd bytes)\n",
- hlen, sizeof ( *tcphdr ) );
- rc = -EINVAL;
- goto discard;
- }
- if ( hlen > iob_len ( iobuf ) ) {
- DBG ( "TCP header too long at %zd bytes (max %zd bytes)\n",
- hlen, iob_len ( iobuf ) );
- rc = -EINVAL;
- goto discard;
- }
- csum = tcpip_continue_chksum ( pshdr_csum, iobuf->data,
- iob_len ( iobuf ) );
- if ( csum != 0 ) {
- DBG ( "TCP checksum incorrect (is %04x including checksum "
- "field, should be 0000)\n", csum );
- rc = -EINVAL;
- goto discard;
- }
-
- /* Parse parameters from header and strip header */
- tcp = tcp_demux ( ntohs ( tcphdr->dest ) );
- seq = ntohl ( tcphdr->seq );
- ack = ntohl ( tcphdr->ack );
- raw_win = ntohs ( tcphdr->win );
- flags = tcphdr->flags;
- tcp_rx_opts ( tcp, ( ( ( void * ) tcphdr ) + sizeof ( *tcphdr ) ),
- ( hlen - sizeof ( *tcphdr ) ), &options );
- if ( tcp && options.tsopt )
- tcp->ts_val = ntohl ( options.tsopt->tsval );
- iob_pull ( iobuf, hlen );
- len = iob_len ( iobuf );
- seq_len = ( len + ( ( flags & TCP_SYN ) ? 1 : 0 ) +
- ( ( flags & TCP_FIN ) ? 1 : 0 ) );
-
- /* Dump header */
- DBGC2 ( tcp, "TCP %p RX %d<-%d %08x %08x..%08x %4zd",
- tcp, ntohs ( tcphdr->dest ), ntohs ( tcphdr->src ),
- ntohl ( tcphdr->ack ), ntohl ( tcphdr->seq ),
- ( ntohl ( tcphdr->seq ) + seq_len ), len );
- tcp_dump_flags ( tcp, tcphdr->flags );
- DBGC2 ( tcp, "\n" );
-
- /* If no connection was found, silently drop packet */
- if ( ! tcp ) {
- rc = -ENOTCONN;
- goto discard;
- }
-
- /* Record old data-transfer window */
- old_xfer_window = tcp_xfer_window ( tcp );
-
- /* Handle ACK, if present */
- if ( flags & TCP_ACK ) {
- win = ( raw_win << tcp->snd_win_scale );
- if ( ( rc = tcp_rx_ack ( tcp, ack, win ) ) != 0 ) {
- tcp_xmit_reset ( tcp, st_src, tcphdr );
- goto discard;
- }
- }
-
- /* Force an ACK if this packet is out of order */
- if ( ( tcp->tcp_state & TCP_STATE_RCVD ( TCP_SYN ) ) &&
- ( seq != tcp->rcv_ack ) ) {
- tcp->flags |= TCP_ACK_PENDING;
- }
-
- /* Handle SYN, if present */
- if ( flags & TCP_SYN ) {
- tcp_rx_syn ( tcp, seq, &options );
- seq++;
- }
-
- /* Handle RST, if present */
- if ( flags & TCP_RST ) {
- if ( ( rc = tcp_rx_rst ( tcp, seq ) ) != 0 )
- goto discard;
- }
-
- /* Enqueue received data */
- tcp_rx_enqueue ( tcp, seq, flags, iob_disown ( iobuf ) );
-
- /* Process receive queue */
- tcp_process_rx_queue ( tcp );
-
- /* Dump out any state change as a result of the received packet */
- tcp_dump_state ( tcp );
-
- /* Schedule transmission of ACK (and any pending data). If we
- * have received any out-of-order packets (i.e. if the receive
- * queue remains non-empty after processing) then send the ACK
- * immediately in order to trigger Fast Retransmission.
- */
- if ( list_empty ( &tcp->rx_queue ) ) {
- process_add ( &tcp->process );
- } else {
- tcp_xmit_sack ( tcp, seq );
- }
-
- /* If this packet was the last we expect to receive, set up
- * timer to expire and cause the connection to be freed.
- */
- if ( TCP_CLOSED_GRACEFULLY ( tcp->tcp_state ) ) {
- stop_timer ( &tcp->wait );
- start_timer_fixed ( &tcp->wait, ( 2 * TCP_MSL ) );
- }
-
- /* Notify application if window has changed */
- if ( tcp_xfer_window ( tcp ) != old_xfer_window )
- xfer_window_changed ( &tcp->xfer );
-
- profile_stop ( &tcp_rx_profiler );
- return 0;
-
- discard:
- /* Free received packet */
- free_iob ( iobuf );
- return rc;
-}
-
-/** TCP protocol */
-struct tcpip_protocol tcp_protocol __tcpip_protocol = {
- .name = "TCP",
- .rx = tcp_rx,
- .tcpip_proto = IP_TCP,
-};
-
-/**
- * Discard some cached TCP data
- *
- * @ret discarded Number of cached items discarded
- */
-static unsigned int tcp_discard ( void ) {
- struct tcp_connection *tcp;
- struct io_buffer *iobuf;
- unsigned int discarded = 0;
-
- /* Try to drop one queued RX packet from each connection */
- list_for_each_entry ( tcp, &tcp_conns, list ) {
- list_for_each_entry_reverse ( iobuf, &tcp->rx_queue, list ) {
-
- /* Remove packet from queue */
- list_del ( &iobuf->list );
- free_iob ( iobuf );
-
- /* Report discard */
- discarded++;
- break;
- }
- }
-
- return discarded;
-}
-
-/** TCP cache discarder */
-struct cache_discarder tcp_discarder __cache_discarder ( CACHE_NORMAL ) = {
- .discard = tcp_discard,
-};
-
-/**
- * Find first TCP connection that has not yet been closed
- *
- * @ret tcp First unclosed connection, or NULL
- */
-static struct tcp_connection * tcp_first_unclosed ( void ) {
- struct tcp_connection *tcp;
-
- /* Find first connection which has not yet been closed */
- list_for_each_entry ( tcp, &tcp_conns, list ) {
- if ( ! ( tcp->flags & TCP_XFER_CLOSED ) )
- return tcp;
- }
- return NULL;
-}
-
-/**
- * Find first TCP connection that has not yet finished all operations
- *
- * @ret tcp First unfinished connection, or NULL
- */
-static struct tcp_connection * tcp_first_unfinished ( void ) {
- struct tcp_connection *tcp;
-
- /* Find first connection which has not yet closed gracefully,
- * or which still has a pending transmission (e.g. to ACK the
- * received FIN).
- */
- list_for_each_entry ( tcp, &tcp_conns, list ) {
- if ( ( ! TCP_CLOSED_GRACEFULLY ( tcp->tcp_state ) ) ||
- process_running ( &tcp->process ) ) {
- return tcp;
- }
- }
- return NULL;
-}
-
-/**
- * Shut down all TCP connections
- *
- */
-static void tcp_shutdown ( int booting __unused ) {
- struct tcp_connection *tcp;
- unsigned long start;
- unsigned long elapsed;
-
- /* Initiate a graceful close of all connections, allowing for
- * the fact that the connection list may change as we do so.
- */
- while ( ( tcp = tcp_first_unclosed() ) ) {
- DBGC ( tcp, "TCP %p closing for shutdown\n", tcp );
- tcp_close ( tcp, -ECANCELED );
- }
-
- /* Wait for all connections to finish closing gracefully */
- start = currticks();
- while ( ( tcp = tcp_first_unfinished() ) &&
- ( ( elapsed = ( currticks() - start ) ) < TCP_FINISH_TIMEOUT )){
- step();
- }
-
- /* Forcibly close any remaining connections */
- while ( ( tcp = list_first_entry ( &tcp_conns, struct tcp_connection,
- list ) ) != NULL ) {
- tcp->tcp_state = TCP_CLOSED;
- tcp_dump_state ( tcp );
- tcp_close ( tcp, -ECANCELED );
- }
-}
-
-/** TCP shutdown function */
-struct startup_fn tcp_startup_fn __startup_fn ( STARTUP_LATE ) = {
- .shutdown = tcp_shutdown,
-};
-
-/***************************************************************************
- *
- * Data transfer interface
- *
- ***************************************************************************
- */
-
-/**
- * Close interface
- *
- * @v tcp TCP connection
- * @v rc Reason for close
- */
-static void tcp_xfer_close ( struct tcp_connection *tcp, int rc ) {
-
- /* Close data transfer interface */
- tcp_close ( tcp, rc );
-
- /* Transmit FIN, if possible */
- tcp_xmit ( tcp );
-}
-
-/**
- * Deliver datagram as I/O buffer
- *
- * @v tcp TCP connection
- * @v iobuf Datagram I/O buffer
- * @v meta Data transfer metadata
- * @ret rc Return status code
- */
-static int tcp_xfer_deliver ( struct tcp_connection *tcp,
- struct io_buffer *iobuf,
- struct xfer_metadata *meta __unused ) {
-
- /* Enqueue packet */
- list_add_tail ( &iobuf->list, &tcp->tx_queue );
-
- /* Each enqueued packet is a pending operation */
- pending_get ( &tcp->pending_data );
-
- /* Transmit data, if possible */
- tcp_xmit ( tcp );
-
- return 0;
-}
-
-/** TCP data transfer interface operations */
-static struct interface_operation tcp_xfer_operations[] = {
- INTF_OP ( xfer_deliver, struct tcp_connection *, tcp_xfer_deliver ),
- INTF_OP ( xfer_window, struct tcp_connection *, tcp_xfer_window ),
- INTF_OP ( intf_close, struct tcp_connection *, tcp_xfer_close ),
-};
-
-/** TCP data transfer interface descriptor */
-static struct interface_descriptor tcp_xfer_desc =
- INTF_DESC ( struct tcp_connection, xfer, tcp_xfer_operations );
-
-/***************************************************************************
- *
- * Openers
- *
- ***************************************************************************
- */
-
-/** TCP IPv4 socket opener */
-struct socket_opener tcp_ipv4_socket_opener __socket_opener = {
- .semantics = TCP_SOCK_STREAM,
- .family = AF_INET,
- .open = tcp_open,
-};
-
-/** TCP IPv6 socket opener */
-struct socket_opener tcp_ipv6_socket_opener __socket_opener = {
- .semantics = TCP_SOCK_STREAM,
- .family = AF_INET6,
- .open = tcp_open,
-};
-
-/** Linkage hack */
-int tcp_sock_stream = TCP_SOCK_STREAM;
-
-/**
- * Open TCP URI
- *
- * @v xfer Data transfer interface
- * @v uri URI
- * @ret rc Return status code
- */
-static int tcp_open_uri ( struct interface *xfer, struct uri *uri ) {
- struct sockaddr_tcpip peer;
-
- /* Sanity check */
- if ( ! uri->host )
- return -EINVAL;
-
- memset ( &peer, 0, sizeof ( peer ) );
- peer.st_port = htons ( uri_port ( uri, 0 ) );
- return xfer_open_named_socket ( xfer, SOCK_STREAM,
- ( struct sockaddr * ) &peer,
- uri->host, NULL );
-}
-
-/** TCP URI opener */
-struct uri_opener tcp_uri_opener __uri_opener = {
- .scheme = "tcp",
- .open = tcp_open_uri,
-};
-