![Piotr Jaroszyński](/assets/img/avatar_default.png)
Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com> Signed-off-by: Michael Brown <mcb30@ipxe.org>
1338 lines
34 KiB
C
1338 lines
34 KiB
C
#include <string.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <assert.h>
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#include <errno.h>
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#include <byteswap.h>
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#include <ipxe/timer.h>
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#include <ipxe/iobuf.h>
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#include <ipxe/malloc.h>
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#include <ipxe/retry.h>
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#include <ipxe/refcnt.h>
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#include <ipxe/xfer.h>
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#include <ipxe/open.h>
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#include <ipxe/uri.h>
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#include <ipxe/tcpip.h>
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#include <ipxe/tcp.h>
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/** @file
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*
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* TCP protocol
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*
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*/
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FILE_LICENCE ( GPL2_OR_LATER );
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/** A TCP connection */
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struct tcp_connection {
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/** Reference counter */
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struct refcnt refcnt;
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/** List of TCP connections */
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struct list_head list;
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/** Flags */
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unsigned int flags;
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/** Data transfer interface */
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struct interface xfer;
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/** Remote socket address */
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struct sockaddr_tcpip peer;
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/** Local port */
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unsigned int local_port;
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/** Current TCP state */
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unsigned int tcp_state;
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/** Previous TCP state
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*
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* Maintained only for debug messages
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*/
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unsigned int prev_tcp_state;
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/** Current sequence number
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*
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* Equivalent to SND.UNA in RFC 793 terminology.
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*/
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uint32_t snd_seq;
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/** Unacknowledged sequence count
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*
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* Equivalent to (SND.NXT-SND.UNA) in RFC 793 terminology.
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*/
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uint32_t snd_sent;
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/** Send window
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*
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* Equivalent to SND.WND in RFC 793 terminology
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*/
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uint32_t snd_win;
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/** Current acknowledgement number
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*
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* Equivalent to RCV.NXT in RFC 793 terminology.
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*/
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uint32_t rcv_ack;
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/** Receive window
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*
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* Equivalent to RCV.WND in RFC 793 terminology.
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*/
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uint32_t rcv_win;
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/** Most recent received timestamp
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*
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* Equivalent to TS.Recent in RFC 1323 terminology.
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*/
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uint32_t ts_recent;
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/** Transmit queue */
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struct list_head tx_queue;
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/** Receive queue */
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struct list_head rx_queue;
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/** Retransmission timer */
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struct retry_timer timer;
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/** Shutdown (TIME_WAIT) timer */
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struct retry_timer wait;
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};
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/** TCP flags */
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enum tcp_flags {
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/** TCP data transfer interface has been closed */
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TCP_XFER_CLOSED = 0x0001,
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/** TCP timestamps are enabled */
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TCP_TS_ENABLED = 0x0002,
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/** TCP acknowledgement is pending */
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TCP_ACK_PENDING = 0x0004,
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};
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/** TCP internal header
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*
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* This is the header that replaces the TCP header for packets
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* enqueued on the receive queue.
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*/
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struct tcp_rx_queued_header {
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/** SEQ value, in host-endian order
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*
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* This represents the SEQ value at the time the packet is
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* enqueued, and so excludes the SYN, if present.
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*/
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uint32_t seq;
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/** Flags
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*
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* Only FIN is valid within this flags byte; all other flags
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* have already been processed by the time the packet is
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* enqueued.
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*/
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uint8_t flags;
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/** Reserved */
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uint8_t reserved[3];
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};
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/**
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* List of registered TCP connections
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*/
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static LIST_HEAD ( tcp_conns );
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/* Forward declarations */
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static struct interface_descriptor tcp_xfer_desc;
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static void tcp_expired ( struct retry_timer *timer, int over );
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static void tcp_wait_expired ( struct retry_timer *timer, int over );
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static int tcp_rx_ack ( struct tcp_connection *tcp, uint32_t ack,
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uint32_t win );
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/**
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* Name TCP state
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*
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* @v state TCP state
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* @ret name Name of TCP state
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*/
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static inline __attribute__ (( always_inline )) const char *
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tcp_state ( int state ) {
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switch ( state ) {
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case TCP_CLOSED: return "CLOSED";
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case TCP_LISTEN: return "LISTEN";
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case TCP_SYN_SENT: return "SYN_SENT";
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case TCP_SYN_RCVD: return "SYN_RCVD";
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case TCP_ESTABLISHED: return "ESTABLISHED";
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case TCP_FIN_WAIT_1: return "FIN_WAIT_1";
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case TCP_FIN_WAIT_2: return "FIN_WAIT_2";
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case TCP_CLOSING_OR_LAST_ACK: return "CLOSING/LAST_ACK";
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case TCP_TIME_WAIT: return "TIME_WAIT";
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case TCP_CLOSE_WAIT: return "CLOSE_WAIT";
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default: return "INVALID";
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}
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}
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/**
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* Dump TCP state transition
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*
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* @v tcp TCP connection
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*/
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static inline __attribute__ (( always_inline )) void
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tcp_dump_state ( struct tcp_connection *tcp ) {
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if ( tcp->tcp_state != tcp->prev_tcp_state ) {
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DBGC ( tcp, "TCP %p transitioned from %s to %s\n", tcp,
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tcp_state ( tcp->prev_tcp_state ),
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tcp_state ( tcp->tcp_state ) );
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}
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tcp->prev_tcp_state = tcp->tcp_state;
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}
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/**
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* Dump TCP flags
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*
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* @v flags TCP flags
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*/
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static inline __attribute__ (( always_inline )) void
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tcp_dump_flags ( struct tcp_connection *tcp, unsigned int flags ) {
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if ( flags & TCP_RST )
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DBGC2 ( tcp, " RST" );
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if ( flags & TCP_SYN )
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DBGC2 ( tcp, " SYN" );
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if ( flags & TCP_PSH )
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DBGC2 ( tcp, " PSH" );
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if ( flags & TCP_FIN )
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DBGC2 ( tcp, " FIN" );
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if ( flags & TCP_ACK )
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DBGC2 ( tcp, " ACK" );
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}
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/***************************************************************************
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*
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* Open and close
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*
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***************************************************************************
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*/
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/**
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* Bind TCP connection to local port
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*
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* @v tcp TCP connection
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* @v port Local port number
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* @ret rc Return status code
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*
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* If the port is 0, the connection is assigned an available port
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* between 1024 and 65535.
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*/
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static int tcp_bind ( struct tcp_connection *tcp, unsigned int port ) {
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struct tcp_connection *existing;
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uint16_t try_port;
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unsigned int i;
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/* If no port is specified, find an available port */
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if ( ! port ) {
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try_port = random();
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for ( i = 0 ; i < 65536 ; i++ ) {
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try_port++;
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if ( try_port < 1024 )
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continue;
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if ( tcp_bind ( tcp, try_port ) == 0 )
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return 0;
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}
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DBGC ( tcp, "TCP %p could not bind: no free ports\n", tcp );
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return -EADDRINUSE;
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}
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/* Attempt bind to local port */
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list_for_each_entry ( existing, &tcp_conns, list ) {
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if ( existing->local_port == port ) {
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DBGC ( tcp, "TCP %p could not bind: port %d in use\n",
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tcp, port );
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return -EADDRINUSE;
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}
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}
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tcp->local_port = port;
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DBGC ( tcp, "TCP %p bound to port %d\n", tcp, port );
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return 0;
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}
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/**
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* Open a TCP connection
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*
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* @v xfer Data transfer interface
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* @v peer Peer socket address
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* @v local Local socket address, or NULL
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* @ret rc Return status code
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*/
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static int tcp_open ( struct interface *xfer, struct sockaddr *peer,
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struct sockaddr *local ) {
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struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
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struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
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struct tcp_connection *tcp;
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unsigned int bind_port;
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int rc;
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/* Allocate and initialise structure */
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tcp = zalloc ( sizeof ( *tcp ) );
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if ( ! tcp )
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return -ENOMEM;
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DBGC ( tcp, "TCP %p allocated\n", tcp );
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ref_init ( &tcp->refcnt, NULL );
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intf_init ( &tcp->xfer, &tcp_xfer_desc, &tcp->refcnt );
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timer_init ( &tcp->timer, tcp_expired );
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timer_init ( &tcp->wait, tcp_wait_expired );
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tcp->prev_tcp_state = TCP_CLOSED;
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tcp->tcp_state = TCP_STATE_SENT ( TCP_SYN );
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tcp_dump_state ( tcp );
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tcp->snd_seq = random();
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INIT_LIST_HEAD ( &tcp->tx_queue );
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INIT_LIST_HEAD ( &tcp->rx_queue );
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memcpy ( &tcp->peer, st_peer, sizeof ( tcp->peer ) );
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/* Bind to local port */
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bind_port = ( st_local ? ntohs ( st_local->st_port ) : 0 );
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if ( ( rc = tcp_bind ( tcp, bind_port ) ) != 0 )
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goto err;
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/* Start timer to initiate SYN */
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start_timer_nodelay ( &tcp->timer );
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/* Attach parent interface, transfer reference to connection
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* list and return
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*/
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intf_plug_plug ( &tcp->xfer, xfer );
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list_add ( &tcp->list, &tcp_conns );
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return 0;
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err:
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ref_put ( &tcp->refcnt );
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return rc;
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}
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/**
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* Close TCP connection
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*
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* @v tcp TCP connection
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* @v rc Reason for close
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*
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* Closes the data transfer interface. If the TCP state machine is in
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* a suitable state, the connection will be deleted.
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*/
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static void tcp_close ( struct tcp_connection *tcp, int rc ) {
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struct io_buffer *iobuf;
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struct io_buffer *tmp;
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/* Close data transfer interface */
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intf_shutdown ( &tcp->xfer, rc );
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tcp->flags |= TCP_XFER_CLOSED;
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/* If we are in CLOSED, or have otherwise not yet received a
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* SYN (i.e. we are in LISTEN or SYN_SENT), just delete the
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* connection.
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*/
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if ( ! ( tcp->tcp_state & TCP_STATE_RCVD ( TCP_SYN ) ) ) {
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/* Transition to CLOSED for the sake of debugging messages */
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tcp->tcp_state = TCP_CLOSED;
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tcp_dump_state ( tcp );
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/* Free any unprocessed I/O buffers */
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list_for_each_entry_safe ( iobuf, tmp, &tcp->rx_queue, list ) {
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list_del ( &iobuf->list );
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free_iob ( iobuf );
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}
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/* Free any unsent I/O buffers */
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list_for_each_entry_safe ( iobuf, tmp, &tcp->tx_queue, list ) {
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list_del ( &iobuf->list );
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free_iob ( iobuf );
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}
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/* Remove from list and drop reference */
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stop_timer ( &tcp->timer );
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list_del ( &tcp->list );
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ref_put ( &tcp->refcnt );
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DBGC ( tcp, "TCP %p connection deleted\n", tcp );
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return;
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}
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/* If we have not had our SYN acknowledged (i.e. we are in
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* SYN_RCVD), pretend that it has been acknowledged so that we
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* can send a FIN without breaking things.
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*/
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if ( ! ( tcp->tcp_state & TCP_STATE_ACKED ( TCP_SYN ) ) )
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tcp_rx_ack ( tcp, ( tcp->snd_seq + 1 ), 0 );
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/* If we have no data remaining to send, start sending FIN */
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if ( list_empty ( &tcp->tx_queue ) ) {
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tcp->tcp_state |= TCP_STATE_SENT ( TCP_FIN );
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tcp_dump_state ( tcp );
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}
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}
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/***************************************************************************
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*
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* Transmit data path
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*
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***************************************************************************
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*/
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/**
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* Calculate transmission window
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*
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* @v tcp TCP connection
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* @ret len Maximum length that can be sent in a single packet
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*/
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static size_t tcp_xmit_win ( struct tcp_connection *tcp ) {
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size_t len;
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/* Not ready if we're not in a suitable connection state */
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if ( ! TCP_CAN_SEND_DATA ( tcp->tcp_state ) )
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return 0;
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/* Length is the minimum of the receiver's window and the path MTU */
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len = tcp->snd_win;
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if ( len > TCP_PATH_MTU )
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len = TCP_PATH_MTU;
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return len;
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}
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/**
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* Process TCP transmit queue
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*
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* @v tcp TCP connection
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* @v max_len Maximum length to process
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* @v dest I/O buffer to fill with data, or NULL
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* @v remove Remove data from queue
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* @ret len Length of data processed
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*
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* This processes at most @c max_len bytes from the TCP connection's
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* transmit queue. Data will be copied into the @c dest I/O buffer
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* (if provided) and, if @c remove is true, removed from the transmit
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* queue.
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*/
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static size_t tcp_process_tx_queue ( struct tcp_connection *tcp, size_t max_len,
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struct io_buffer *dest, int remove ) {
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struct io_buffer *iobuf;
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struct io_buffer *tmp;
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size_t frag_len;
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size_t len = 0;
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list_for_each_entry_safe ( iobuf, tmp, &tcp->tx_queue, list ) {
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frag_len = iob_len ( iobuf );
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if ( frag_len > max_len )
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frag_len = max_len;
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if ( dest ) {
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memcpy ( iob_put ( dest, frag_len ), iobuf->data,
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frag_len );
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}
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if ( remove ) {
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iob_pull ( iobuf, frag_len );
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if ( ! iob_len ( iobuf ) ) {
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list_del ( &iobuf->list );
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free_iob ( iobuf );
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}
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}
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len += frag_len;
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max_len -= frag_len;
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}
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return len;
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}
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/**
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* Transmit any outstanding data
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*
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* @v tcp TCP connection
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*
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* Transmits any outstanding data on the connection.
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*
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* Note that even if an error is returned, the retransmission timer
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* will have been started if necessary, and so the stack will
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* eventually attempt to retransmit the failed packet.
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*/
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static int tcp_xmit ( struct tcp_connection *tcp ) {
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struct io_buffer *iobuf;
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struct tcp_header *tcphdr;
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struct tcp_mss_option *mssopt;
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struct tcp_timestamp_padded_option *tsopt;
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void *payload;
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unsigned int flags;
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size_t len = 0;
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uint32_t seq_len;
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uint32_t app_win;
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uint32_t max_rcv_win;
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int rc;
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/* If retransmission timer is already running, do nothing */
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if ( timer_running ( &tcp->timer ) )
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return 0;
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/* Calculate both the actual (payload) and sequence space
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* lengths that we wish to transmit.
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*/
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if ( TCP_CAN_SEND_DATA ( tcp->tcp_state ) ) {
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len = tcp_process_tx_queue ( tcp, tcp_xmit_win ( tcp ),
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NULL, 0 );
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}
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seq_len = len;
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flags = TCP_FLAGS_SENDING ( tcp->tcp_state );
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if ( flags & ( TCP_SYN | TCP_FIN ) ) {
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/* SYN or FIN consume one byte, and we can never send both */
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assert ( ! ( ( flags & TCP_SYN ) && ( flags & TCP_FIN ) ) );
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seq_len++;
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}
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tcp->snd_sent = seq_len;
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/* If we have nothing to transmit, stop now */
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if ( ( seq_len == 0 ) && ! ( tcp->flags & TCP_ACK_PENDING ) )
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return 0;
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|
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/* If we are transmitting anything that requires
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* acknowledgement (i.e. consumes sequence space), start the
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* retransmission timer. Do this before attempting to
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* allocate the I/O buffer, in case allocation itself fails.
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*/
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if ( seq_len )
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start_timer ( &tcp->timer );
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/* Allocate I/O buffer */
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iobuf = alloc_iob ( len + MAX_HDR_LEN );
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if ( ! iobuf ) {
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DBGC ( tcp, "TCP %p could not allocate iobuf for %08x..%08x "
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"%08x\n", tcp, tcp->snd_seq, ( tcp->snd_seq + seq_len ),
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tcp->rcv_ack );
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return -ENOMEM;
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}
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iob_reserve ( iobuf, MAX_HDR_LEN );
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/* Fill data payload from transmit queue */
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tcp_process_tx_queue ( tcp, len, iobuf, 0 );
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/* Expand receive window if possible */
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max_rcv_win = ( ( freemem * 3 ) / 4 );
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if ( max_rcv_win > TCP_MAX_WINDOW_SIZE )
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max_rcv_win = TCP_MAX_WINDOW_SIZE;
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app_win = xfer_window ( &tcp->xfer );
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if ( max_rcv_win > app_win )
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max_rcv_win = app_win;
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max_rcv_win &= ~0x03; /* Keep everything dword-aligned */
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if ( tcp->rcv_win < max_rcv_win )
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tcp->rcv_win = max_rcv_win;
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/* Fill up the TCP header */
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payload = iobuf->data;
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if ( flags & TCP_SYN ) {
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mssopt = iob_push ( iobuf, sizeof ( *mssopt ) );
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mssopt->kind = TCP_OPTION_MSS;
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mssopt->length = sizeof ( *mssopt );
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mssopt->mss = htons ( TCP_MSS );
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}
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if ( ( flags & TCP_SYN ) || ( tcp->flags & TCP_TS_ENABLED ) ) {
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tsopt = iob_push ( iobuf, sizeof ( *tsopt ) );
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memset ( tsopt->nop, TCP_OPTION_NOP, sizeof ( tsopt->nop ) );
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tsopt->tsopt.kind = TCP_OPTION_TS;
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tsopt->tsopt.length = sizeof ( tsopt->tsopt );
|
|
tsopt->tsopt.tsval = htonl ( currticks() );
|
|
tsopt->tsopt.tsecr = htonl ( tcp->ts_recent );
|
|
}
|
|
if ( ! ( flags & TCP_SYN ) )
|
|
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 );
|
|
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 rc;
|
|
}
|
|
|
|
/* Clear ACK-pending flag */
|
|
tcp->flags &= ~TCP_ACK_PENDING;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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 ( MAX_HDR_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, MAX_HDR_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 ( TCP_MAX_WINDOW_SIZE );
|
|
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_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 ) {
|
|
tcp->rcv_ack += seq_len;
|
|
if ( tcp->rcv_win > seq_len ) {
|
|
tcp->rcv_win -= seq_len;
|
|
} else {
|
|
tcp->rcv_win = 0;
|
|
}
|
|
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;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
}
|
|
|
|
/* 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--;
|
|
|
|
/* Update SEQ and sent counters, and window size */
|
|
tcp->snd_seq = ack;
|
|
tcp->snd_sent = 0;
|
|
tcp->snd_win = win;
|
|
|
|
/* 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 );
|
|
|
|
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 */
|
|
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;
|
|
}
|
|
|
|
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;
|
|
|
|
/* 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 ) );
|
|
|
|
/* 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 ( seq + seq_len, tcp->rcv_ack ) < 0 ) ||
|
|
( seq_len == 0 ) ) {
|
|
free_iob ( iobuf );
|
|
return;
|
|
}
|
|
|
|
/* Add internal header */
|
|
tcpqhdr = iob_push ( iobuf, sizeof ( *tcpqhdr ) );
|
|
tcpqhdr->seq = seq;
|
|
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 ( ! list_empty ( &tcp->rx_queue ) ) {
|
|
list_for_each_entry ( iobuf, &tcp->rx_queue, list )
|
|
break;
|
|
|
|
/* 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 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 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;
|
|
uint32_t win;
|
|
unsigned int flags;
|
|
size_t len;
|
|
uint32_t seq_len;
|
|
int rc;
|
|
|
|
/* 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 );
|
|
win = ntohs ( tcphdr->win );
|
|
flags = tcphdr->flags;
|
|
tcp_rx_opts ( tcp, ( ( ( void * ) tcphdr ) + sizeof ( *tcphdr ) ),
|
|
( hlen - sizeof ( *tcphdr ) ), &options );
|
|
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, send RST */
|
|
if ( ! tcp ) {
|
|
tcp_xmit_reset ( tcp, st_src, tcphdr );
|
|
rc = -ENOTCONN;
|
|
goto discard;
|
|
}
|
|
|
|
/* Update timestamp, if applicable */
|
|
if ( options.tsopt && tcp_in_window ( tcp->rcv_ack, seq, seq_len ) )
|
|
tcp->ts_recent = ntohl ( options.tsopt->tsval );
|
|
|
|
/* Handle ACK, if present */
|
|
if ( flags & TCP_ACK ) {
|
|
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 );
|
|
|
|
/* Send out any pending data */
|
|
tcp_xmit ( tcp );
|
|
|
|
/* 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 ) );
|
|
}
|
|
|
|
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 ) {
|
|
list_del ( &iobuf->list );
|
|
free_iob ( iobuf );
|
|
discarded++;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return discarded;
|
|
}
|
|
|
|
/** TCP cache discarder */
|
|
struct cache_discarder tcp_cache_discarder __cache_discarder = {
|
|
.discard = tcp_discard,
|
|
};
|
|
|
|
/***************************************************************************
|
|
*
|
|
* 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 );
|
|
}
|
|
|
|
/**
|
|
* Check 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 );
|
|
}
|
|
|
|
/**
|
|
* 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 );
|
|
|
|
/* 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 socket opener */
|
|
struct socket_opener tcp_socket_opener __socket_opener = {
|
|
.semantics = TCP_SOCK_STREAM,
|
|
.family = AF_INET,
|
|
.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,
|
|
};
|
|
|