/* SCTP kernel reference Implementation
|
/* SCTP kernel reference Implementation
|
* (C) Copyright IBM Corp. 2001, 2004
|
* (C) Copyright IBM Corp. 2001, 2004
|
* Copyright (c) 1999-2000 Cisco, Inc.
|
* Copyright (c) 1999-2000 Cisco, Inc.
|
* Copyright (c) 1999-2001 Motorola, Inc.
|
* Copyright (c) 1999-2001 Motorola, Inc.
|
*
|
*
|
* This file is part of the SCTP kernel reference Implementation
|
* This file is part of the SCTP kernel reference Implementation
|
*
|
*
|
* These functions handle output processing.
|
* These functions handle output processing.
|
*
|
*
|
* The SCTP reference implementation is free software;
|
* The SCTP reference implementation is free software;
|
* you can redistribute it and/or modify it under the terms of
|
* you can redistribute it and/or modify it under the terms of
|
* the GNU General Public License as published by
|
* the GNU General Public License as published by
|
* the Free Software Foundation; either version 2, or (at your option)
|
* the Free Software Foundation; either version 2, or (at your option)
|
* any later version.
|
* any later version.
|
*
|
*
|
* The SCTP reference implementation is distributed in the hope that it
|
* The SCTP reference implementation is distributed in the hope that it
|
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
|
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
|
* ************************
|
* ************************
|
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
* See the GNU General Public License for more details.
|
* See the GNU General Public License for more details.
|
*
|
*
|
* You should have received a copy of the GNU General Public License
|
* You should have received a copy of the GNU General Public License
|
* along with GNU CC; see the file COPYING. If not, write to
|
* along with GNU CC; see the file COPYING. If not, write to
|
* the Free Software Foundation, 59 Temple Place - Suite 330,
|
* the Free Software Foundation, 59 Temple Place - Suite 330,
|
* Boston, MA 02111-1307, USA.
|
* Boston, MA 02111-1307, USA.
|
*
|
*
|
* Please send any bug reports or fixes you make to the
|
* Please send any bug reports or fixes you make to the
|
* email address(es):
|
* email address(es):
|
* lksctp developers <lksctp-developers@lists.sourceforge.net>
|
* lksctp developers <lksctp-developers@lists.sourceforge.net>
|
*
|
*
|
* Or submit a bug report through the following website:
|
* Or submit a bug report through the following website:
|
* http://www.sf.net/projects/lksctp
|
* http://www.sf.net/projects/lksctp
|
*
|
*
|
* Written or modified by:
|
* Written or modified by:
|
* La Monte H.P. Yarroll <piggy@acm.org>
|
* La Monte H.P. Yarroll <piggy@acm.org>
|
* Karl Knutson <karl@athena.chicago.il.us>
|
* Karl Knutson <karl@athena.chicago.il.us>
|
* Jon Grimm <jgrimm@austin.ibm.com>
|
* Jon Grimm <jgrimm@austin.ibm.com>
|
* Sridhar Samudrala <sri@us.ibm.com>
|
* Sridhar Samudrala <sri@us.ibm.com>
|
*
|
*
|
* Any bugs reported given to us we will try to fix... any fixes shared will
|
* Any bugs reported given to us we will try to fix... any fixes shared will
|
* be incorporated into the next SCTP release.
|
* be incorporated into the next SCTP release.
|
*/
|
*/
|
|
|
#include <linux/types.h>
|
#include <linux/types.h>
|
#include <linux/kernel.h>
|
#include <linux/kernel.h>
|
#include <linux/wait.h>
|
#include <linux/wait.h>
|
#include <linux/time.h>
|
#include <linux/time.h>
|
#include <linux/ip.h>
|
#include <linux/ip.h>
|
#include <linux/ipv6.h>
|
#include <linux/ipv6.h>
|
#include <linux/init.h>
|
#include <linux/init.h>
|
#include <net/inet_ecn.h>
|
#include <net/inet_ecn.h>
|
#include <net/icmp.h>
|
#include <net/icmp.h>
|
|
|
#ifndef TEST_FRAME
|
#ifndef TEST_FRAME
|
#include <net/tcp.h>
|
#include <net/tcp.h>
|
#endif /* TEST_FRAME (not defined) */
|
#endif /* TEST_FRAME (not defined) */
|
|
|
#include <linux/socket.h> /* for sa_family_t */
|
#include <linux/socket.h> /* for sa_family_t */
|
#include <net/sock.h>
|
#include <net/sock.h>
|
|
|
#include <net/sctp/sctp.h>
|
#include <net/sctp/sctp.h>
|
#include <net/sctp/sm.h>
|
#include <net/sctp/sm.h>
|
|
|
/* Forward declarations for private helpers. */
|
/* Forward declarations for private helpers. */
|
static void sctp_packet_reset(struct sctp_packet *packet);
|
static void sctp_packet_reset(struct sctp_packet *packet);
|
static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
|
static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
|
struct sctp_chunk *chunk);
|
struct sctp_chunk *chunk);
|
|
|
/* Config a packet.
|
/* Config a packet.
|
* This appears to be a followup set of initializations.)
|
* This appears to be a followup set of initializations.)
|
*/
|
*/
|
struct sctp_packet *sctp_packet_config(struct sctp_packet *packet,
|
struct sctp_packet *sctp_packet_config(struct sctp_packet *packet,
|
__u32 vtag, int ecn_capable,
|
__u32 vtag, int ecn_capable,
|
sctp_packet_phandler_t *prepend_handler)
|
sctp_packet_phandler_t *prepend_handler)
|
{
|
{
|
int packet_empty = (packet->size == SCTP_IP_OVERHEAD);
|
int packet_empty = (packet->size == SCTP_IP_OVERHEAD);
|
|
|
packet->vtag = vtag;
|
packet->vtag = vtag;
|
packet->ecn_capable = ecn_capable;
|
packet->ecn_capable = ecn_capable;
|
packet->get_prepend_chunk = prepend_handler;
|
packet->get_prepend_chunk = prepend_handler;
|
packet->has_cookie_echo = 0;
|
packet->has_cookie_echo = 0;
|
packet->has_sack = 0;
|
packet->has_sack = 0;
|
packet->ipfragok = 0;
|
packet->ipfragok = 0;
|
|
|
/* We might need to call the prepend_handler right away. */
|
/* We might need to call the prepend_handler right away. */
|
if (packet_empty)
|
if (packet_empty)
|
sctp_packet_reset(packet);
|
sctp_packet_reset(packet);
|
return packet;
|
return packet;
|
}
|
}
|
|
|
/* Initialize the packet structure. */
|
/* Initialize the packet structure. */
|
struct sctp_packet *sctp_packet_init(struct sctp_packet *packet,
|
struct sctp_packet *sctp_packet_init(struct sctp_packet *packet,
|
struct sctp_transport *transport,
|
struct sctp_transport *transport,
|
__u16 sport, __u16 dport)
|
__u16 sport, __u16 dport)
|
{
|
{
|
packet->transport = transport;
|
packet->transport = transport;
|
packet->source_port = sport;
|
packet->source_port = sport;
|
packet->destination_port = dport;
|
packet->destination_port = dport;
|
skb_queue_head_init(&packet->chunks);
|
skb_queue_head_init(&packet->chunks);
|
packet->size = SCTP_IP_OVERHEAD;
|
packet->size = SCTP_IP_OVERHEAD;
|
packet->vtag = 0;
|
packet->vtag = 0;
|
packet->ecn_capable = 0;
|
packet->ecn_capable = 0;
|
packet->get_prepend_chunk = NULL;
|
packet->get_prepend_chunk = NULL;
|
packet->has_cookie_echo = 0;
|
packet->has_cookie_echo = 0;
|
packet->has_sack = 0;
|
packet->has_sack = 0;
|
packet->ipfragok = 0;
|
packet->ipfragok = 0;
|
packet->malloced = 0;
|
packet->malloced = 0;
|
sctp_packet_reset(packet);
|
sctp_packet_reset(packet);
|
return packet;
|
return packet;
|
}
|
}
|
|
|
/* Free a packet. */
|
/* Free a packet. */
|
void sctp_packet_free(struct sctp_packet *packet)
|
void sctp_packet_free(struct sctp_packet *packet)
|
{
|
{
|
struct sctp_chunk *chunk;
|
struct sctp_chunk *chunk;
|
|
|
while ((chunk = (struct sctp_chunk *)__skb_dequeue(&packet->chunks)))
|
while ((chunk = (struct sctp_chunk *)__skb_dequeue(&packet->chunks)))
|
sctp_chunk_free(chunk);
|
sctp_chunk_free(chunk);
|
|
|
if (packet->malloced)
|
if (packet->malloced)
|
kfree(packet);
|
kfree(packet);
|
}
|
}
|
|
|
/* This routine tries to append the chunk to the offered packet. If adding
|
/* This routine tries to append the chunk to the offered packet. If adding
|
* the chunk causes the packet to exceed the path MTU and COOKIE_ECHO chunk
|
* the chunk causes the packet to exceed the path MTU and COOKIE_ECHO chunk
|
* is not present in the packet, it transmits the input packet.
|
* is not present in the packet, it transmits the input packet.
|
* Data can be bundled with a packet containing a COOKIE_ECHO chunk as long
|
* Data can be bundled with a packet containing a COOKIE_ECHO chunk as long
|
* as it can fit in the packet, but any more data that does not fit in this
|
* as it can fit in the packet, but any more data that does not fit in this
|
* packet can be sent only after receiving the COOKIE_ACK.
|
* packet can be sent only after receiving the COOKIE_ACK.
|
*/
|
*/
|
sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *packet,
|
sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *packet,
|
struct sctp_chunk *chunk)
|
struct sctp_chunk *chunk)
|
{
|
{
|
sctp_xmit_t retval;
|
sctp_xmit_t retval;
|
int error = 0;
|
int error = 0;
|
|
|
switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) {
|
switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) {
|
case SCTP_XMIT_PMTU_FULL:
|
case SCTP_XMIT_PMTU_FULL:
|
if (!packet->has_cookie_echo) {
|
if (!packet->has_cookie_echo) {
|
error = sctp_packet_transmit(packet);
|
error = sctp_packet_transmit(packet);
|
if (error < 0)
|
if (error < 0)
|
chunk->skb->sk->sk_err = -error;
|
chunk->skb->sk->sk_err = -error;
|
|
|
/* If we have an empty packet, then we can NOT ever
|
/* If we have an empty packet, then we can NOT ever
|
* return PMTU_FULL.
|
* return PMTU_FULL.
|
*/
|
*/
|
retval = sctp_packet_append_chunk(packet, chunk);
|
retval = sctp_packet_append_chunk(packet, chunk);
|
}
|
}
|
break;
|
break;
|
|
|
case SCTP_XMIT_MUST_FRAG:
|
case SCTP_XMIT_MUST_FRAG:
|
case SCTP_XMIT_RWND_FULL:
|
case SCTP_XMIT_RWND_FULL:
|
case SCTP_XMIT_OK:
|
case SCTP_XMIT_OK:
|
case SCTP_XMIT_NAGLE_DELAY:
|
case SCTP_XMIT_NAGLE_DELAY:
|
break;
|
break;
|
};
|
};
|
|
|
return retval;
|
return retval;
|
}
|
}
|
|
|
/* Try to bundle a SACK with the packet. */
|
/* Try to bundle a SACK with the packet. */
|
static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt,
|
static sctp_xmit_t sctp_packet_bundle_sack(struct sctp_packet *pkt,
|
struct sctp_chunk *chunk)
|
struct sctp_chunk *chunk)
|
{
|
{
|
sctp_xmit_t retval = SCTP_XMIT_OK;
|
sctp_xmit_t retval = SCTP_XMIT_OK;
|
|
|
/* If sending DATA and haven't aleady bundled a SACK, try to
|
/* If sending DATA and haven't aleady bundled a SACK, try to
|
* bundle one in to the packet.
|
* bundle one in to the packet.
|
*/
|
*/
|
if (sctp_chunk_is_data(chunk) && !pkt->has_sack &&
|
if (sctp_chunk_is_data(chunk) && !pkt->has_sack &&
|
!pkt->has_cookie_echo) {
|
!pkt->has_cookie_echo) {
|
struct sctp_association *asoc;
|
struct sctp_association *asoc;
|
asoc = pkt->transport->asoc;
|
asoc = pkt->transport->asoc;
|
|
|
if (asoc->a_rwnd > asoc->rwnd) {
|
if (asoc->a_rwnd > asoc->rwnd) {
|
struct sctp_chunk *sack;
|
struct sctp_chunk *sack;
|
asoc->a_rwnd = asoc->rwnd;
|
asoc->a_rwnd = asoc->rwnd;
|
sack = sctp_make_sack(asoc);
|
sack = sctp_make_sack(asoc);
|
if (sack) {
|
if (sack) {
|
struct timer_list *timer;
|
struct timer_list *timer;
|
retval = sctp_packet_append_chunk(pkt, sack);
|
retval = sctp_packet_append_chunk(pkt, sack);
|
asoc->peer.sack_needed = 0;
|
asoc->peer.sack_needed = 0;
|
timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
|
timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
|
if (timer_pending(timer) && del_timer(timer))
|
if (timer_pending(timer) && del_timer(timer))
|
sctp_association_put(asoc);
|
sctp_association_put(asoc);
|
}
|
}
|
}
|
}
|
}
|
}
|
return retval;
|
return retval;
|
}
|
}
|
|
|
/* Append a chunk to the offered packet reporting back any inability to do
|
/* Append a chunk to the offered packet reporting back any inability to do
|
* so.
|
* so.
|
*/
|
*/
|
sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
|
sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
|
struct sctp_chunk *chunk)
|
struct sctp_chunk *chunk)
|
{
|
{
|
sctp_xmit_t retval = SCTP_XMIT_OK;
|
sctp_xmit_t retval = SCTP_XMIT_OK;
|
__u16 chunk_len = WORD_ROUND(ntohs(chunk->chunk_hdr->length));
|
__u16 chunk_len = WORD_ROUND(ntohs(chunk->chunk_hdr->length));
|
size_t psize;
|
size_t psize;
|
size_t pmtu;
|
size_t pmtu;
|
int too_big;
|
int too_big;
|
|
|
retval = sctp_packet_bundle_sack(packet, chunk);
|
retval = sctp_packet_bundle_sack(packet, chunk);
|
psize = packet->size;
|
psize = packet->size;
|
|
|
if (retval != SCTP_XMIT_OK)
|
if (retval != SCTP_XMIT_OK)
|
goto finish;
|
goto finish;
|
|
|
pmtu = ((packet->transport->asoc) ?
|
pmtu = ((packet->transport->asoc) ?
|
(packet->transport->asoc->pmtu) :
|
(packet->transport->asoc->pmtu) :
|
(packet->transport->pmtu));
|
(packet->transport->pmtu));
|
|
|
too_big = (psize + chunk_len > pmtu);
|
too_big = (psize + chunk_len > pmtu);
|
|
|
/* Decide if we need to fragment or resubmit later. */
|
/* Decide if we need to fragment or resubmit later. */
|
if (too_big) {
|
if (too_big) {
|
int packet_empty = (packet->size == SCTP_IP_OVERHEAD);
|
int packet_empty = (packet->size == SCTP_IP_OVERHEAD);
|
|
|
/* Both control chunks and data chunks with TSNs are
|
/* Both control chunks and data chunks with TSNs are
|
* non-fragmentable.
|
* non-fragmentable.
|
*/
|
*/
|
if (packet_empty || !sctp_chunk_is_data(chunk)) {
|
if (packet_empty || !sctp_chunk_is_data(chunk)) {
|
/* We no longer do re-fragmentation.
|
/* We no longer do re-fragmentation.
|
* Just fragment at the IP layer, if we
|
* Just fragment at the IP layer, if we
|
* actually hit this condition
|
* actually hit this condition
|
*/
|
*/
|
|
|
packet->ipfragok = 1;
|
packet->ipfragok = 1;
|
goto append;
|
goto append;
|
|
|
} else {
|
} else {
|
retval = SCTP_XMIT_PMTU_FULL;
|
retval = SCTP_XMIT_PMTU_FULL;
|
goto finish;
|
goto finish;
|
}
|
}
|
} else {
|
} else {
|
/* The chunk fits in the packet. */
|
/* The chunk fits in the packet. */
|
goto append;
|
goto append;
|
}
|
}
|
|
|
append:
|
append:
|
/* We believe that this chunk is OK to add to the packet (as
|
/* We believe that this chunk is OK to add to the packet (as
|
* long as we have the cwnd for it).
|
* long as we have the cwnd for it).
|
*/
|
*/
|
|
|
/* DATA is a special case since we must examine both rwnd and cwnd
|
/* DATA is a special case since we must examine both rwnd and cwnd
|
* before we send DATA.
|
* before we send DATA.
|
*/
|
*/
|
if (sctp_chunk_is_data(chunk)) {
|
if (sctp_chunk_is_data(chunk)) {
|
retval = sctp_packet_append_data(packet, chunk);
|
retval = sctp_packet_append_data(packet, chunk);
|
/* Disallow SACK bundling after DATA. */
|
/* Disallow SACK bundling after DATA. */
|
packet->has_sack = 1;
|
packet->has_sack = 1;
|
if (SCTP_XMIT_OK != retval)
|
if (SCTP_XMIT_OK != retval)
|
goto finish;
|
goto finish;
|
} else if (SCTP_CID_COOKIE_ECHO == chunk->chunk_hdr->type)
|
} else if (SCTP_CID_COOKIE_ECHO == chunk->chunk_hdr->type)
|
packet->has_cookie_echo = 1;
|
packet->has_cookie_echo = 1;
|
else if (SCTP_CID_SACK == chunk->chunk_hdr->type)
|
else if (SCTP_CID_SACK == chunk->chunk_hdr->type)
|
packet->has_sack = 1;
|
packet->has_sack = 1;
|
|
|
/* It is OK to send this chunk. */
|
/* It is OK to send this chunk. */
|
__skb_queue_tail(&packet->chunks, (struct sk_buff *)chunk);
|
__skb_queue_tail(&packet->chunks, (struct sk_buff *)chunk);
|
packet->size += chunk_len;
|
packet->size += chunk_len;
|
finish:
|
finish:
|
return retval;
|
return retval;
|
}
|
}
|
|
|
/* All packets are sent to the network through this function from
|
/* All packets are sent to the network through this function from
|
* sctp_outq_tail().
|
* sctp_outq_tail().
|
*
|
*
|
* The return value is a normal kernel error return value.
|
* The return value is a normal kernel error return value.
|
*/
|
*/
|
int sctp_packet_transmit(struct sctp_packet *packet)
|
int sctp_packet_transmit(struct sctp_packet *packet)
|
{
|
{
|
struct sctp_transport *tp = packet->transport;
|
struct sctp_transport *tp = packet->transport;
|
struct sctp_association *asoc = tp->asoc;
|
struct sctp_association *asoc = tp->asoc;
|
struct sctphdr *sh;
|
struct sctphdr *sh;
|
__u32 crc32;
|
__u32 crc32;
|
struct sk_buff *nskb;
|
struct sk_buff *nskb;
|
struct sctp_chunk *chunk;
|
struct sctp_chunk *chunk;
|
struct sock *sk;
|
struct sock *sk;
|
int err = 0;
|
int err = 0;
|
int padding; /* How much padding do we need? */
|
int padding; /* How much padding do we need? */
|
__u8 has_data = 0;
|
__u8 has_data = 0;
|
struct dst_entry *dst;
|
struct dst_entry *dst;
|
|
|
/* Do NOT generate a chunkless packet. */
|
/* Do NOT generate a chunkless packet. */
|
chunk = (struct sctp_chunk *)skb_peek(&packet->chunks);
|
chunk = (struct sctp_chunk *)skb_peek(&packet->chunks);
|
if (unlikely(!chunk))
|
if (unlikely(!chunk))
|
return err;
|
return err;
|
|
|
/* Set up convenience variables... */
|
/* Set up convenience variables... */
|
sk = chunk->skb->sk;
|
sk = chunk->skb->sk;
|
|
|
/* Allocate the new skb. */
|
/* Allocate the new skb. */
|
nskb = dev_alloc_skb(packet->size);
|
nskb = dev_alloc_skb(packet->size);
|
if (!nskb)
|
if (!nskb)
|
goto nomem;
|
goto nomem;
|
|
|
/* Make sure the outbound skb has enough header room reserved. */
|
/* Make sure the outbound skb has enough header room reserved. */
|
skb_reserve(nskb, SCTP_IP_OVERHEAD);
|
skb_reserve(nskb, SCTP_IP_OVERHEAD);
|
|
|
/* Set the owning socket so that we know where to get the
|
/* Set the owning socket so that we know where to get the
|
* destination IP address.
|
* destination IP address.
|
*/
|
*/
|
skb_set_owner_w(nskb, sk);
|
skb_set_owner_w(nskb, sk);
|
|
|
/* Build the SCTP header. */
|
/* Build the SCTP header. */
|
sh = (struct sctphdr *)skb_push(nskb, sizeof(struct sctphdr));
|
sh = (struct sctphdr *)skb_push(nskb, sizeof(struct sctphdr));
|
sh->source = htons(packet->source_port);
|
sh->source = htons(packet->source_port);
|
sh->dest = htons(packet->destination_port);
|
sh->dest = htons(packet->destination_port);
|
|
|
/* From 6.8 Adler-32 Checksum Calculation:
|
/* From 6.8 Adler-32 Checksum Calculation:
|
* After the packet is constructed (containing the SCTP common
|
* After the packet is constructed (containing the SCTP common
|
* header and one or more control or DATA chunks), the
|
* header and one or more control or DATA chunks), the
|
* transmitter shall:
|
* transmitter shall:
|
*
|
*
|
* 1) Fill in the proper Verification Tag in the SCTP common
|
* 1) Fill in the proper Verification Tag in the SCTP common
|
* header and initialize the checksum field to 0's.
|
* header and initialize the checksum field to 0's.
|
*/
|
*/
|
sh->vtag = htonl(packet->vtag);
|
sh->vtag = htonl(packet->vtag);
|
sh->checksum = 0;
|
sh->checksum = 0;
|
|
|
/* 2) Calculate the Adler-32 checksum of the whole packet,
|
/* 2) Calculate the Adler-32 checksum of the whole packet,
|
* including the SCTP common header and all the
|
* including the SCTP common header and all the
|
* chunks.
|
* chunks.
|
*
|
*
|
* Note: Adler-32 is no longer applicable, as has been replaced
|
* Note: Adler-32 is no longer applicable, as has been replaced
|
* by CRC32-C as described in <draft-ietf-tsvwg-sctpcsum-02.txt>.
|
* by CRC32-C as described in <draft-ietf-tsvwg-sctpcsum-02.txt>.
|
*/
|
*/
|
crc32 = sctp_start_cksum((__u8 *)sh, sizeof(struct sctphdr));
|
crc32 = sctp_start_cksum((__u8 *)sh, sizeof(struct sctphdr));
|
|
|
/**
|
/**
|
* 6.10 Bundling
|
* 6.10 Bundling
|
*
|
*
|
* An endpoint bundles chunks by simply including multiple
|
* An endpoint bundles chunks by simply including multiple
|
* chunks in one outbound SCTP packet. ...
|
* chunks in one outbound SCTP packet. ...
|
*/
|
*/
|
|
|
/**
|
/**
|
* 3.2 Chunk Field Descriptions
|
* 3.2 Chunk Field Descriptions
|
*
|
*
|
* The total length of a chunk (including Type, Length and
|
* The total length of a chunk (including Type, Length and
|
* Value fields) MUST be a multiple of 4 bytes. If the length
|
* Value fields) MUST be a multiple of 4 bytes. If the length
|
* of the chunk is not a multiple of 4 bytes, the sender MUST
|
* of the chunk is not a multiple of 4 bytes, the sender MUST
|
* pad the chunk with all zero bytes and this padding is not
|
* pad the chunk with all zero bytes and this padding is not
|
* included in the chunk length field. The sender should
|
* included in the chunk length field. The sender should
|
* never pad with more than 3 bytes.
|
* never pad with more than 3 bytes.
|
*
|
*
|
* [This whole comment explains WORD_ROUND() below.]
|
* [This whole comment explains WORD_ROUND() below.]
|
*/
|
*/
|
SCTP_DEBUG_PRINTK("***sctp_transmit_packet***\n");
|
SCTP_DEBUG_PRINTK("***sctp_transmit_packet***\n");
|
while ((chunk = (struct sctp_chunk *)__skb_dequeue(&packet->chunks))) {
|
while ((chunk = (struct sctp_chunk *)__skb_dequeue(&packet->chunks))) {
|
if (sctp_chunk_is_data(chunk)) {
|
if (sctp_chunk_is_data(chunk)) {
|
|
|
if (!chunk->has_tsn) {
|
if (!chunk->has_tsn) {
|
sctp_chunk_assign_ssn(chunk);
|
sctp_chunk_assign_ssn(chunk);
|
sctp_chunk_assign_tsn(chunk);
|
sctp_chunk_assign_tsn(chunk);
|
|
|
/* 6.3.1 C4) When data is in flight and when allowed
|
/* 6.3.1 C4) When data is in flight and when allowed
|
* by rule C5, a new RTT measurement MUST be made each
|
* by rule C5, a new RTT measurement MUST be made each
|
* round trip. Furthermore, new RTT measurements
|
* round trip. Furthermore, new RTT measurements
|
* SHOULD be made no more than once per round-trip
|
* SHOULD be made no more than once per round-trip
|
* for a given destination transport address.
|
* for a given destination transport address.
|
*/
|
*/
|
|
|
if (!tp->rto_pending) {
|
if (!tp->rto_pending) {
|
chunk->rtt_in_progress = 1;
|
chunk->rtt_in_progress = 1;
|
tp->rto_pending = 1;
|
tp->rto_pending = 1;
|
}
|
}
|
} else
|
} else
|
chunk->resent = 1;
|
chunk->resent = 1;
|
|
|
chunk->sent_at = jiffies;
|
chunk->sent_at = jiffies;
|
has_data = 1;
|
has_data = 1;
|
}
|
}
|
|
|
padding = WORD_ROUND(chunk->skb->len) - chunk->skb->len;
|
padding = WORD_ROUND(chunk->skb->len) - chunk->skb->len;
|
if (padding)
|
if (padding)
|
memset(skb_put(chunk->skb, padding), 0, padding);
|
memset(skb_put(chunk->skb, padding), 0, padding);
|
|
|
crc32 = sctp_update_copy_cksum(skb_put(nskb, chunk->skb->len),
|
crc32 = sctp_update_copy_cksum(skb_put(nskb, chunk->skb->len),
|
chunk->skb->data,
|
chunk->skb->data,
|
chunk->skb->len, crc32);
|
chunk->skb->len, crc32);
|
|
|
SCTP_DEBUG_PRINTK("%s %p[%s] %s 0x%x, %s %d, %s %d, %s %d\n",
|
SCTP_DEBUG_PRINTK("%s %p[%s] %s 0x%x, %s %d, %s %d, %s %d\n",
|
"*** Chunk", chunk,
|
"*** Chunk", chunk,
|
sctp_cname(SCTP_ST_CHUNK(
|
sctp_cname(SCTP_ST_CHUNK(
|
chunk->chunk_hdr->type)),
|
chunk->chunk_hdr->type)),
|
chunk->has_tsn ? "TSN" : "No TSN",
|
chunk->has_tsn ? "TSN" : "No TSN",
|
chunk->has_tsn ?
|
chunk->has_tsn ?
|
ntohl(chunk->subh.data_hdr->tsn) : 0,
|
ntohl(chunk->subh.data_hdr->tsn) : 0,
|
"length", ntohs(chunk->chunk_hdr->length),
|
"length", ntohs(chunk->chunk_hdr->length),
|
"chunk->skb->len", chunk->skb->len,
|
"chunk->skb->len", chunk->skb->len,
|
"rtt_in_progress", chunk->rtt_in_progress);
|
"rtt_in_progress", chunk->rtt_in_progress);
|
|
|
/*
|
/*
|
* If this is a control chunk, this is our last
|
* If this is a control chunk, this is our last
|
* reference. Free data chunks after they've been
|
* reference. Free data chunks after they've been
|
* acknowledged or have failed.
|
* acknowledged or have failed.
|
*/
|
*/
|
if (!sctp_chunk_is_data(chunk))
|
if (!sctp_chunk_is_data(chunk))
|
sctp_chunk_free(chunk);
|
sctp_chunk_free(chunk);
|
}
|
}
|
|
|
/* Perform final transformation on checksum. */
|
/* Perform final transformation on checksum. */
|
crc32 = sctp_end_cksum(crc32);
|
crc32 = sctp_end_cksum(crc32);
|
|
|
/* 3) Put the resultant value into the checksum field in the
|
/* 3) Put the resultant value into the checksum field in the
|
* common header, and leave the rest of the bits unchanged.
|
* common header, and leave the rest of the bits unchanged.
|
*/
|
*/
|
sh->checksum = htonl(crc32);
|
sh->checksum = htonl(crc32);
|
|
|
/* IP layer ECN support
|
/* IP layer ECN support
|
* From RFC 2481
|
* From RFC 2481
|
* "The ECN-Capable Transport (ECT) bit would be set by the
|
* "The ECN-Capable Transport (ECT) bit would be set by the
|
* data sender to indicate that the end-points of the
|
* data sender to indicate that the end-points of the
|
* transport protocol are ECN-capable."
|
* transport protocol are ECN-capable."
|
*
|
*
|
* Now setting the ECT bit all the time, as it should not cause
|
* Now setting the ECT bit all the time, as it should not cause
|
* any problems protocol-wise even if our peer ignores it.
|
* any problems protocol-wise even if our peer ignores it.
|
*
|
*
|
* Note: The works for IPv6 layer checks this bit too later
|
* Note: The works for IPv6 layer checks this bit too later
|
* in transmission. See IP6_ECN_flow_xmit().
|
* in transmission. See IP6_ECN_flow_xmit().
|
*/
|
*/
|
INET_ECN_xmit(nskb->sk);
|
INET_ECN_xmit(nskb->sk);
|
|
|
/* Set up the IP options. */
|
/* Set up the IP options. */
|
/* BUG: not implemented
|
/* BUG: not implemented
|
* For v4 this all lives somewhere in sk->sk_opt...
|
* For v4 this all lives somewhere in sk->sk_opt...
|
*/
|
*/
|
|
|
/* Dump that on IP! */
|
/* Dump that on IP! */
|
if (asoc && asoc->peer.last_sent_to != tp) {
|
if (asoc && asoc->peer.last_sent_to != tp) {
|
/* Considering the multiple CPU scenario, this is a
|
/* Considering the multiple CPU scenario, this is a
|
* "correcter" place for last_sent_to. --xguo
|
* "correcter" place for last_sent_to. --xguo
|
*/
|
*/
|
asoc->peer.last_sent_to = tp;
|
asoc->peer.last_sent_to = tp;
|
}
|
}
|
|
|
if (has_data) {
|
if (has_data) {
|
struct timer_list *timer;
|
struct timer_list *timer;
|
unsigned long timeout;
|
unsigned long timeout;
|
|
|
tp->last_time_used = jiffies;
|
tp->last_time_used = jiffies;
|
|
|
/* Restart the AUTOCLOSE timer when sending data. */
|
/* Restart the AUTOCLOSE timer when sending data. */
|
if (sctp_state(asoc, ESTABLISHED) && asoc->autoclose) {
|
if (sctp_state(asoc, ESTABLISHED) && asoc->autoclose) {
|
timer = &asoc->timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE];
|
timer = &asoc->timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE];
|
timeout = asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE];
|
timeout = asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE];
|
|
|
if (!mod_timer(timer, jiffies + timeout))
|
if (!mod_timer(timer, jiffies + timeout))
|
sctp_association_hold(asoc);
|
sctp_association_hold(asoc);
|
}
|
}
|
}
|
}
|
|
|
dst = tp->dst;
|
dst = tp->dst;
|
/* The 'obsolete' field of dst is set to 2 when a dst is freed. */
|
/* The 'obsolete' field of dst is set to 2 when a dst is freed. */
|
if (!dst || (dst->obsolete > 1)) {
|
if (!dst || (dst->obsolete > 1)) {
|
dst_release(dst);
|
dst_release(dst);
|
sctp_transport_route(tp, NULL, sctp_sk(sk));
|
sctp_transport_route(tp, NULL, sctp_sk(sk));
|
sctp_assoc_sync_pmtu(asoc);
|
sctp_assoc_sync_pmtu(asoc);
|
}
|
}
|
|
|
nskb->dst = dst_clone(tp->dst);
|
nskb->dst = dst_clone(tp->dst);
|
if (!nskb->dst)
|
if (!nskb->dst)
|
goto no_route;
|
goto no_route;
|
|
|
SCTP_DEBUG_PRINTK("***sctp_transmit_packet*** skb len %d\n",
|
SCTP_DEBUG_PRINTK("***sctp_transmit_packet*** skb len %d\n",
|
nskb->len);
|
nskb->len);
|
|
|
(*tp->af_specific->sctp_xmit)(nskb, tp, packet->ipfragok);
|
(*tp->af_specific->sctp_xmit)(nskb, tp, packet->ipfragok);
|
|
|
out:
|
out:
|
packet->size = SCTP_IP_OVERHEAD;
|
packet->size = SCTP_IP_OVERHEAD;
|
return err;
|
return err;
|
no_route:
|
no_route:
|
kfree_skb(nskb);
|
kfree_skb(nskb);
|
IP_INC_STATS_BH(IpOutNoRoutes);
|
IP_INC_STATS_BH(IpOutNoRoutes);
|
|
|
/* FIXME: Returning the 'err' will effect all the associations
|
/* FIXME: Returning the 'err' will effect all the associations
|
* associated with a socket, although only one of the paths of the
|
* associated with a socket, although only one of the paths of the
|
* association is unreachable.
|
* association is unreachable.
|
* The real failure of a transport or association can be passed on
|
* The real failure of a transport or association can be passed on
|
* to the user via notifications. So setting this error may not be
|
* to the user via notifications. So setting this error may not be
|
* required.
|
* required.
|
*/
|
*/
|
/* err = -EHOSTUNREACH; */
|
/* err = -EHOSTUNREACH; */
|
err:
|
err:
|
/* Control chunks are unreliable so just drop them. DATA chunks
|
/* Control chunks are unreliable so just drop them. DATA chunks
|
* will get resent or dropped later.
|
* will get resent or dropped later.
|
*/
|
*/
|
|
|
while ((chunk = (struct sctp_chunk *)__skb_dequeue(&packet->chunks))) {
|
while ((chunk = (struct sctp_chunk *)__skb_dequeue(&packet->chunks))) {
|
if (!sctp_chunk_is_data(chunk))
|
if (!sctp_chunk_is_data(chunk))
|
sctp_chunk_free(chunk);
|
sctp_chunk_free(chunk);
|
}
|
}
|
goto out;
|
goto out;
|
nomem:
|
nomem:
|
err = -ENOMEM;
|
err = -ENOMEM;
|
printk("%s alloc_skb failed.\n", __FUNCTION__);
|
printk("%s alloc_skb failed.\n", __FUNCTION__);
|
goto err;
|
goto err;
|
}
|
}
|
|
|
/********************************************************************
|
/********************************************************************
|
* 2nd Level Abstractions
|
* 2nd Level Abstractions
|
********************************************************************/
|
********************************************************************/
|
|
|
/*
|
/*
|
* This private function resets the packet to a fresh state.
|
* This private function resets the packet to a fresh state.
|
*/
|
*/
|
static void sctp_packet_reset(struct sctp_packet *packet)
|
static void sctp_packet_reset(struct sctp_packet *packet)
|
{
|
{
|
struct sctp_chunk *chunk = NULL;
|
struct sctp_chunk *chunk = NULL;
|
|
|
packet->size = SCTP_IP_OVERHEAD;
|
packet->size = SCTP_IP_OVERHEAD;
|
|
|
if (packet->get_prepend_chunk)
|
if (packet->get_prepend_chunk)
|
chunk = packet->get_prepend_chunk(packet->transport->asoc);
|
chunk = packet->get_prepend_chunk(packet->transport->asoc);
|
|
|
/* If there a is a prepend chunk stick it on the list before
|
/* If there a is a prepend chunk stick it on the list before
|
* any other chunks get appended.
|
* any other chunks get appended.
|
*/
|
*/
|
if (chunk)
|
if (chunk)
|
sctp_packet_append_chunk(packet, chunk);
|
sctp_packet_append_chunk(packet, chunk);
|
}
|
}
|
|
|
/* This private function handles the specifics of appending DATA chunks. */
|
/* This private function handles the specifics of appending DATA chunks. */
|
static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
|
static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
|
struct sctp_chunk *chunk)
|
struct sctp_chunk *chunk)
|
{
|
{
|
sctp_xmit_t retval = SCTP_XMIT_OK;
|
sctp_xmit_t retval = SCTP_XMIT_OK;
|
size_t datasize, rwnd, inflight;
|
size_t datasize, rwnd, inflight;
|
struct sctp_transport *transport = packet->transport;
|
struct sctp_transport *transport = packet->transport;
|
__u32 max_burst_bytes;
|
__u32 max_burst_bytes;
|
struct sctp_association *asoc = transport->asoc;
|
struct sctp_association *asoc = transport->asoc;
|
struct sctp_opt *sp = sctp_sk(asoc->base.sk);
|
struct sctp_opt *sp = sctp_sk(asoc->base.sk);
|
struct sctp_outq *q = &asoc->outqueue;
|
struct sctp_outq *q = &asoc->outqueue;
|
|
|
/* RFC 2960 6.1 Transmission of DATA Chunks
|
/* RFC 2960 6.1 Transmission of DATA Chunks
|
*
|
*
|
* A) At any given time, the data sender MUST NOT transmit new data to
|
* A) At any given time, the data sender MUST NOT transmit new data to
|
* any destination transport address if its peer's rwnd indicates
|
* any destination transport address if its peer's rwnd indicates
|
* that the peer has no buffer space (i.e. rwnd is 0, see Section
|
* that the peer has no buffer space (i.e. rwnd is 0, see Section
|
* 6.2.1). However, regardless of the value of rwnd (including if it
|
* 6.2.1). However, regardless of the value of rwnd (including if it
|
* is 0), the data sender can always have one DATA chunk in flight to
|
* is 0), the data sender can always have one DATA chunk in flight to
|
* the receiver if allowed by cwnd (see rule B below). This rule
|
* the receiver if allowed by cwnd (see rule B below). This rule
|
* allows the sender to probe for a change in rwnd that the sender
|
* allows the sender to probe for a change in rwnd that the sender
|
* missed due to the SACK having been lost in transit from the data
|
* missed due to the SACK having been lost in transit from the data
|
* receiver to the data sender.
|
* receiver to the data sender.
|
*/
|
*/
|
|
|
rwnd = asoc->peer.rwnd;
|
rwnd = asoc->peer.rwnd;
|
inflight = asoc->outqueue.outstanding_bytes;
|
inflight = asoc->outqueue.outstanding_bytes;
|
|
|
datasize = sctp_data_size(chunk);
|
datasize = sctp_data_size(chunk);
|
|
|
if (datasize > rwnd) {
|
if (datasize > rwnd) {
|
if (inflight > 0) {
|
if (inflight > 0) {
|
/* We have (at least) one data chunk in flight,
|
/* We have (at least) one data chunk in flight,
|
* so we can't fall back to rule 6.1 B).
|
* so we can't fall back to rule 6.1 B).
|
*/
|
*/
|
retval = SCTP_XMIT_RWND_FULL;
|
retval = SCTP_XMIT_RWND_FULL;
|
goto finish;
|
goto finish;
|
}
|
}
|
}
|
}
|
|
|
/* sctpimpguide-05 2.14.2
|
/* sctpimpguide-05 2.14.2
|
* D) When the time comes for the sender to
|
* D) When the time comes for the sender to
|
* transmit new DATA chunks, the protocol parameter Max.Burst MUST
|
* transmit new DATA chunks, the protocol parameter Max.Burst MUST
|
* first be applied to limit how many new DATA chunks may be sent.
|
* first be applied to limit how many new DATA chunks may be sent.
|
* The limit is applied by adjusting cwnd as follows:
|
* The limit is applied by adjusting cwnd as follows:
|
* if ((flightsize + Max.Burst * MTU) < cwnd)
|
* if ((flightsize + Max.Burst * MTU) < cwnd)
|
* cwnd = flightsize + Max.Burst * MTU
|
* cwnd = flightsize + Max.Burst * MTU
|
*/
|
*/
|
max_burst_bytes = asoc->max_burst * asoc->pmtu;
|
max_burst_bytes = asoc->max_burst * asoc->pmtu;
|
if ((transport->flight_size + max_burst_bytes) < transport->cwnd) {
|
if ((transport->flight_size + max_burst_bytes) < transport->cwnd) {
|
transport->cwnd = transport->flight_size + max_burst_bytes;
|
transport->cwnd = transport->flight_size + max_burst_bytes;
|
SCTP_DEBUG_PRINTK("%s: cwnd limited by max_burst: "
|
SCTP_DEBUG_PRINTK("%s: cwnd limited by max_burst: "
|
"transport: %p, cwnd: %d, "
|
"transport: %p, cwnd: %d, "
|
"ssthresh: %d, flight_size: %d, "
|
"ssthresh: %d, flight_size: %d, "
|
"pba: %d\n",
|
"pba: %d\n",
|
__FUNCTION__, transport,
|
__FUNCTION__, transport,
|
transport->cwnd,
|
transport->cwnd,
|
transport->ssthresh,
|
transport->ssthresh,
|
transport->flight_size,
|
transport->flight_size,
|
transport->partial_bytes_acked);
|
transport->partial_bytes_acked);
|
}
|
}
|
|
|
/* RFC 2960 6.1 Transmission of DATA Chunks
|
/* RFC 2960 6.1 Transmission of DATA Chunks
|
*
|
*
|
* B) At any given time, the sender MUST NOT transmit new data
|
* B) At any given time, the sender MUST NOT transmit new data
|
* to a given transport address if it has cwnd or more bytes
|
* to a given transport address if it has cwnd or more bytes
|
* of data outstanding to that transport address.
|
* of data outstanding to that transport address.
|
*/
|
*/
|
/* RFC 7.2.4 & the Implementers Guide 2.8.
|
/* RFC 7.2.4 & the Implementers Guide 2.8.
|
*
|
*
|
* 3) ...
|
* 3) ...
|
* When a Fast Retransmit is being performed the sender SHOULD
|
* When a Fast Retransmit is being performed the sender SHOULD
|
* ignore the value of cwnd and SHOULD NOT delay retransmission.
|
* ignore the value of cwnd and SHOULD NOT delay retransmission.
|
*/
|
*/
|
if (!chunk->fast_retransmit)
|
if (!chunk->fast_retransmit)
|
if (transport->flight_size >= transport->cwnd) {
|
if (transport->flight_size >= transport->cwnd) {
|
retval = SCTP_XMIT_RWND_FULL;
|
retval = SCTP_XMIT_RWND_FULL;
|
goto finish;
|
goto finish;
|
}
|
}
|
|
|
/* Nagle's algorithm to solve small-packet problem:
|
/* Nagle's algorithm to solve small-packet problem:
|
* Inhibit the sending of new chunks when new outgoing data arrives
|
* Inhibit the sending of new chunks when new outgoing data arrives
|
* if any previously transmitted data on the connection remains
|
* if any previously transmitted data on the connection remains
|
* unacknowledged.
|
* unacknowledged.
|
*/
|
*/
|
if (!sp->nodelay && SCTP_IP_OVERHEAD == packet->size &&
|
if (!sp->nodelay && SCTP_IP_OVERHEAD == packet->size &&
|
q->outstanding_bytes && sctp_state(asoc, ESTABLISHED)) {
|
q->outstanding_bytes && sctp_state(asoc, ESTABLISHED)) {
|
unsigned len = datasize + q->out_qlen;
|
unsigned len = datasize + q->out_qlen;
|
|
|
/* Check whether this chunk and all the rest of pending
|
/* Check whether this chunk and all the rest of pending
|
* data will fit or delay in hopes of bundling a full
|
* data will fit or delay in hopes of bundling a full
|
* sized packet.
|
* sized packet.
|
*/
|
*/
|
if (len < asoc->pmtu - SCTP_IP_OVERHEAD) {
|
if (len < asoc->pmtu - SCTP_IP_OVERHEAD) {
|
retval = SCTP_XMIT_NAGLE_DELAY;
|
retval = SCTP_XMIT_NAGLE_DELAY;
|
goto finish;
|
goto finish;
|
}
|
}
|
}
|
}
|
|
|
/* Keep track of how many bytes are in flight over this transport. */
|
/* Keep track of how many bytes are in flight over this transport. */
|
transport->flight_size += datasize;
|
transport->flight_size += datasize;
|
|
|
/* Keep track of how many bytes are in flight to the receiver. */
|
/* Keep track of how many bytes are in flight to the receiver. */
|
asoc->outqueue.outstanding_bytes += datasize;
|
asoc->outqueue.outstanding_bytes += datasize;
|
|
|
/* Update our view of the receiver's rwnd. */
|
/* Update our view of the receiver's rwnd. */
|
if (datasize < rwnd)
|
if (datasize < rwnd)
|
rwnd -= datasize;
|
rwnd -= datasize;
|
else
|
else
|
rwnd = 0;
|
rwnd = 0;
|
|
|
asoc->peer.rwnd = rwnd;
|
asoc->peer.rwnd = rwnd;
|
/* Has been accepted for transmission. */
|
/* Has been accepted for transmission. */
|
chunk->msg->can_expire = 0;
|
chunk->msg->can_expire = 0;
|
|
|
finish:
|
finish:
|
return retval;
|
return retval;
|
}
|
}
|
|
|
