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linux/net/netfilter/nf_conntrack_proto_sctp.c
Xin Long 9bfab6d23a netfilter: set default timeout to 3 secs for sctp shutdown send and recv state 
In SCTP protocol, it is using the same timer (T2 timer) for SHUTDOWN and
SHUTDOWN_ACK retransmission. However in sctp conntrack the default timeout
value for SCTP_CONNTRACK_SHUTDOWN_ACK_SENT state is 3 secs while it's 300
msecs for SCTP_CONNTRACK_SHUTDOWN_SEND/RECV state.

As Paolo Valerio noticed, this might cause unwanted expiration of the ct
entry. In my test, with 1s tc netem delay set on the NAT path, after the
SHUTDOWN is sent, the sctp ct entry enters SCTP_CONNTRACK_SHUTDOWN_SEND
state. However, due to 300ms (too short) delay, when the SHUTDOWN_ACK is
sent back from the peer, the sctp ct entry has expired and been deleted,
and then the SHUTDOWN_ACK has to be dropped.

Also, it is confusing these two sysctl options always show 0 due to all
timeout values using sec as unit:

  net.netfilter.nf_conntrack_sctp_timeout_shutdown_recd = 0
  net.netfilter.nf_conntrack_sctp_timeout_shutdown_sent = 0

This patch fixes it by also using 3 secs for sctp shutdown send and recv
state in sctp conntrack, which is also RTO.initial value in SCTP protocol.

Note that the very short time value for SCTP_CONNTRACK_SHUTDOWN_SEND/RECV
was probably used for a rare scenario where SHUTDOWN is sent on 1st path
but SHUTDOWN_ACK is replied on 2nd path, then a new connection started
immediately on 1st path. So this patch also moves from SHUTDOWN_SEND/RECV
to CLOSE when receiving INIT in the ORIGINAL direction.

Fixes: 9fb9cbb108 ("[NETFILTER]: Add nf_conntrack subsystem.")
Reported-by: Paolo Valerio <pvalerio@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
2023-08-16 00:05:15 +02:00

708 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Connection tracking protocol helper module for SCTP.
*
* Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
* Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
*
* SCTP is defined in RFC 2960. References to various sections in this code
* are to this RFC.
*/
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/netfilter.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/sctp.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <net/sctp/checksum.h>
#include <net/netfilter/nf_log.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_timeout.h>
static const char *const sctp_conntrack_names[] = {
[SCTP_CONNTRACK_NONE] = "NONE",
[SCTP_CONNTRACK_CLOSED] = "CLOSED",
[SCTP_CONNTRACK_COOKIE_WAIT] = "COOKIE_WAIT",
[SCTP_CONNTRACK_COOKIE_ECHOED] = "COOKIE_ECHOED",
[SCTP_CONNTRACK_ESTABLISHED] = "ESTABLISHED",
[SCTP_CONNTRACK_SHUTDOWN_SENT] = "SHUTDOWN_SENT",
[SCTP_CONNTRACK_SHUTDOWN_RECD] = "SHUTDOWN_RECD",
[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = "SHUTDOWN_ACK_SENT",
[SCTP_CONNTRACK_HEARTBEAT_SENT] = "HEARTBEAT_SENT",
};
#define SECS * HZ
#define MINS * 60 SECS
#define HOURS * 60 MINS
#define DAYS * 24 HOURS
static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = {
[SCTP_CONNTRACK_CLOSED] = 10 SECS,
[SCTP_CONNTRACK_COOKIE_WAIT] = 3 SECS,
[SCTP_CONNTRACK_COOKIE_ECHOED] = 3 SECS,
[SCTP_CONNTRACK_ESTABLISHED] = 210 SECS,
[SCTP_CONNTRACK_SHUTDOWN_SENT] = 3 SECS,
[SCTP_CONNTRACK_SHUTDOWN_RECD] = 3 SECS,
[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = 3 SECS,
[SCTP_CONNTRACK_HEARTBEAT_SENT] = 30 SECS,
};
#define SCTP_FLAG_HEARTBEAT_VTAG_FAILED 1
#define sNO SCTP_CONNTRACK_NONE
#define sCL SCTP_CONNTRACK_CLOSED
#define sCW SCTP_CONNTRACK_COOKIE_WAIT
#define sCE SCTP_CONNTRACK_COOKIE_ECHOED
#define sES SCTP_CONNTRACK_ESTABLISHED
#define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
#define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
#define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
#define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
#define sIV SCTP_CONNTRACK_MAX
/*
These are the descriptions of the states:
NOTE: These state names are tantalizingly similar to the states of an
SCTP endpoint. But the interpretation of the states is a little different,
considering that these are the states of the connection and not of an end
point. Please note the subtleties. -Kiran
NONE - Nothing so far.
COOKIE WAIT - We have seen an INIT chunk in the original direction, or also
an INIT_ACK chunk in the reply direction.
COOKIE ECHOED - We have seen a COOKIE_ECHO chunk in the original direction.
ESTABLISHED - We have seen a COOKIE_ACK in the reply direction.
SHUTDOWN_SENT - We have seen a SHUTDOWN chunk in the original direction.
SHUTDOWN_RECD - We have seen a SHUTDOWN chunk in the reply direction.
SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
to that of the SHUTDOWN chunk.
CLOSED - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
the SHUTDOWN chunk. Connection is closed.
HEARTBEAT_SENT - We have seen a HEARTBEAT in a new flow.
*/
/* TODO
- I have assumed that the first INIT is in the original direction.
This messes things when an INIT comes in the reply direction in CLOSED
state.
- Check the error type in the reply dir before transitioning from
cookie echoed to closed.
- Sec 5.2.4 of RFC 2960
- Full Multi Homing support.
*/
/* SCTP conntrack state transitions */
static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
{
/* ORIGINAL */
/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS */
/* init */ {sCL, sCL, sCW, sCE, sES, sCL, sCL, sSA, sCW},
/* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},
/* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
/* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL},
/* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA},
/* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},/* Can't have Stale cookie*/
/* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL},/* 5.2.4 - Big TODO */
/* cookie_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},/* Can't come in orig dir */
/* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL},
/* heartbeat */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
/* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
},
{
/* REPLY */
/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS */
/* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV},/* INIT in sCL Big TODO */
/* init_ack */ {sIV, sCW, sCW, sCE, sES, sSS, sSR, sSA, sIV},
/* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV},
/* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV},
/* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV},
/* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV},
/* cookie_echo */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV},/* Can't come in reply dir */
/* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV},
/* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV},
/* heartbeat */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
/* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sES},
}
};
#ifdef CONFIG_NF_CONNTRACK_PROCFS
/* Print out the private part of the conntrack. */
static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
{
seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]);
}
#endif
/* do_basic_checks ensures sch->length > 0, do not use before */
#define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \
for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0; \
(offset) < (skb)->len && \
((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \
(offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
/* Some validity checks to make sure the chunks are fine */
static int do_basic_checks(struct nf_conn *ct,
const struct sk_buff *skb,
unsigned int dataoff,
unsigned long *map,
const struct nf_hook_state *state)
{
u_int32_t offset, count;
struct sctp_chunkhdr _sch, *sch;
int flag;
flag = 0;
for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
if (sch->type == SCTP_CID_INIT ||
sch->type == SCTP_CID_INIT_ACK ||
sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
flag = 1;
/*
* Cookie Ack/Echo chunks not the first OR
* Init / Init Ack / Shutdown compl chunks not the only chunks
* OR zero-length.
*/
if (((sch->type == SCTP_CID_COOKIE_ACK ||
sch->type == SCTP_CID_COOKIE_ECHO ||
flag) &&
count != 0) || !sch->length) {
nf_ct_l4proto_log_invalid(skb, ct, state,
"%s failed. chunk num %d, type %d, len %d flag %d\n",
__func__, count, sch->type, sch->length, flag);
return 1;
}
if (map)
set_bit(sch->type, map);
}
return count == 0;
}
static int sctp_new_state(enum ip_conntrack_dir dir,
enum sctp_conntrack cur_state,
int chunk_type)
{
int i;
switch (chunk_type) {
case SCTP_CID_INIT:
i = 0;
break;
case SCTP_CID_INIT_ACK:
i = 1;
break;
case SCTP_CID_ABORT:
i = 2;
break;
case SCTP_CID_SHUTDOWN:
i = 3;
break;
case SCTP_CID_SHUTDOWN_ACK:
i = 4;
break;
case SCTP_CID_ERROR:
i = 5;
break;
case SCTP_CID_COOKIE_ECHO:
i = 6;
break;
case SCTP_CID_COOKIE_ACK:
i = 7;
break;
case SCTP_CID_SHUTDOWN_COMPLETE:
i = 8;
break;
case SCTP_CID_HEARTBEAT:
i = 9;
break;
case SCTP_CID_HEARTBEAT_ACK:
i = 10;
break;
default:
/* Other chunks like DATA or SACK do not change the state */
pr_debug("Unknown chunk type %d, Will stay in %s\n",
chunk_type, sctp_conntrack_names[cur_state]);
return cur_state;
}
return sctp_conntracks[dir][i][cur_state];
}
/* Don't need lock here: this conntrack not in circulation yet */
static noinline bool
sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
const struct sctphdr *sh, unsigned int dataoff)
{
enum sctp_conntrack new_state;
const struct sctp_chunkhdr *sch;
struct sctp_chunkhdr _sch;
u32 offset, count;
memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
new_state = SCTP_CONNTRACK_MAX;
for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) {
new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
SCTP_CONNTRACK_NONE, sch->type);
/* Invalid: delete conntrack */
if (new_state == SCTP_CONNTRACK_NONE ||
new_state == SCTP_CONNTRACK_MAX) {
pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
return false;
}
/* Copy the vtag into the state info */
if (sch->type == SCTP_CID_INIT) {
struct sctp_inithdr _inithdr, *ih;
/* Sec 8.5.1 (A) */
if (sh->vtag)
return false;
ih = skb_header_pointer(skb, offset + sizeof(_sch),
sizeof(_inithdr), &_inithdr);
if (!ih)
return false;
pr_debug("Setting vtag %x for new conn\n",
ih->init_tag);
ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag;
} else if (sch->type == SCTP_CID_HEARTBEAT) {
pr_debug("Setting vtag %x for secondary conntrack\n",
sh->vtag);
ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
} else {
/* If it is a shutdown ack OOTB packet, we expect a return
shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
pr_debug("Setting vtag %x for new conn OOTB\n",
sh->vtag);
ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
}
ct->proto.sctp.state = SCTP_CONNTRACK_NONE;
}
return true;
}
static bool sctp_error(struct sk_buff *skb,
unsigned int dataoff,
const struct nf_hook_state *state)
{
const struct sctphdr *sh;
const char *logmsg;
if (skb->len < dataoff + sizeof(struct sctphdr)) {
logmsg = "nf_ct_sctp: short packet ";
goto out_invalid;
}
if (state->hook == NF_INET_PRE_ROUTING &&
state->net->ct.sysctl_checksum &&
skb->ip_summed == CHECKSUM_NONE) {
if (skb_ensure_writable(skb, dataoff + sizeof(*sh))) {
logmsg = "nf_ct_sctp: failed to read header ";
goto out_invalid;
}
sh = (const struct sctphdr *)(skb->data + dataoff);
if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
logmsg = "nf_ct_sctp: bad CRC ";
goto out_invalid;
}
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
return false;
out_invalid:
nf_l4proto_log_invalid(skb, state, IPPROTO_SCTP, "%s", logmsg);
return true;
}
/* Returns verdict for packet, or -NF_ACCEPT for invalid. */
int nf_conntrack_sctp_packet(struct nf_conn *ct,
struct sk_buff *skb,
unsigned int dataoff,
enum ip_conntrack_info ctinfo,
const struct nf_hook_state *state)
{
enum sctp_conntrack new_state, old_state;
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
const struct sctphdr *sh;
struct sctphdr _sctph;
const struct sctp_chunkhdr *sch;
struct sctp_chunkhdr _sch;
u_int32_t offset, count;
unsigned int *timeouts;
unsigned long map[256 / sizeof(unsigned long)] = { 0 };
bool ignore = false;
if (sctp_error(skb, dataoff, state))
return -NF_ACCEPT;
sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
if (sh == NULL)
goto out;
if (do_basic_checks(ct, skb, dataoff, map, state) != 0)
goto out;
if (!nf_ct_is_confirmed(ct)) {
/* If an OOTB packet has any of these chunks discard (Sec 8.4) */
if (test_bit(SCTP_CID_ABORT, map) ||
test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
test_bit(SCTP_CID_COOKIE_ACK, map))
return -NF_ACCEPT;
if (!sctp_new(ct, skb, sh, dataoff))
return -NF_ACCEPT;
}
/* Check the verification tag (Sec 8.5) */
if (!test_bit(SCTP_CID_INIT, map) &&
!test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
!test_bit(SCTP_CID_COOKIE_ECHO, map) &&
!test_bit(SCTP_CID_ABORT, map) &&
!test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
!test_bit(SCTP_CID_HEARTBEAT, map) &&
!test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
sh->vtag != ct->proto.sctp.vtag[dir]) {
nf_ct_l4proto_log_invalid(skb, ct, state,
"verification tag check failed %x vs %x for dir %d",
sh->vtag, ct->proto.sctp.vtag[dir], dir);
goto out;
}
old_state = new_state = SCTP_CONNTRACK_NONE;
spin_lock_bh(&ct->lock);
for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
/* Special cases of Verification tag check (Sec 8.5.1) */
if (sch->type == SCTP_CID_INIT) {
/* (A) vtag MUST be zero */
if (sh->vtag != 0)
goto out_unlock;
} else if (sch->type == SCTP_CID_ABORT) {
/* (B) vtag MUST match own vtag if T flag is unset OR
* MUST match peer's vtag if T flag is set
*/
if ((!(sch->flags & SCTP_CHUNK_FLAG_T) &&
sh->vtag != ct->proto.sctp.vtag[dir]) ||
((sch->flags & SCTP_CHUNK_FLAG_T) &&
sh->vtag != ct->proto.sctp.vtag[!dir]))
goto out_unlock;
} else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
/* (C) vtag MUST match own vtag if T flag is unset OR
* MUST match peer's vtag if T flag is set
*/
if ((!(sch->flags & SCTP_CHUNK_FLAG_T) &&
sh->vtag != ct->proto.sctp.vtag[dir]) ||
((sch->flags & SCTP_CHUNK_FLAG_T) &&
sh->vtag != ct->proto.sctp.vtag[!dir]))
goto out_unlock;
} else if (sch->type == SCTP_CID_COOKIE_ECHO) {
/* (D) vtag must be same as init_vtag as found in INIT_ACK */
if (sh->vtag != ct->proto.sctp.vtag[dir])
goto out_unlock;
} else if (sch->type == SCTP_CID_HEARTBEAT) {
if (ct->proto.sctp.vtag[dir] == 0) {
pr_debug("Setting %d vtag %x for dir %d\n", sch->type, sh->vtag, dir);
ct->proto.sctp.vtag[dir] = sh->vtag;
} else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
if (test_bit(SCTP_CID_DATA, map) || ignore)
goto out_unlock;
ct->proto.sctp.flags |= SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
ct->proto.sctp.last_dir = dir;
ignore = true;
continue;
} else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) {
ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
}
} else if (sch->type == SCTP_CID_HEARTBEAT_ACK) {
if (ct->proto.sctp.vtag[dir] == 0) {
pr_debug("Setting vtag %x for dir %d\n",
sh->vtag, dir);
ct->proto.sctp.vtag[dir] = sh->vtag;
} else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
if (test_bit(SCTP_CID_DATA, map) || ignore)
goto out_unlock;
if ((ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) == 0 ||
ct->proto.sctp.last_dir == dir)
goto out_unlock;
ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
ct->proto.sctp.vtag[dir] = sh->vtag;
ct->proto.sctp.vtag[!dir] = 0;
} else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) {
ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
}
}
old_state = ct->proto.sctp.state;
new_state = sctp_new_state(dir, old_state, sch->type);
/* Invalid */
if (new_state == SCTP_CONNTRACK_MAX) {
nf_ct_l4proto_log_invalid(skb, ct, state,
"Invalid, old_state %d, dir %d, type %d",
old_state, dir, sch->type);
goto out_unlock;
}
/* If it is an INIT or an INIT ACK note down the vtag */
if (sch->type == SCTP_CID_INIT ||
sch->type == SCTP_CID_INIT_ACK) {
struct sctp_inithdr _inithdr, *ih;
ih = skb_header_pointer(skb, offset + sizeof(_sch),
sizeof(_inithdr), &_inithdr);
if (ih == NULL)
goto out_unlock;
pr_debug("Setting vtag %x for dir %d\n",
ih->init_tag, !dir);
ct->proto.sctp.vtag[!dir] = ih->init_tag;
/* don't renew timeout on init retransmit so
* port reuse by client or NAT middlebox cannot
* keep entry alive indefinitely (incl. nat info).
*/
if (new_state == SCTP_CONNTRACK_CLOSED &&
old_state == SCTP_CONNTRACK_CLOSED &&
nf_ct_is_confirmed(ct))
ignore = true;
}
ct->proto.sctp.state = new_state;
if (old_state != new_state) {
nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
if (new_state == SCTP_CONNTRACK_ESTABLISHED &&
!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
nf_conntrack_event_cache(IPCT_ASSURED, ct);
}
}
spin_unlock_bh(&ct->lock);
/* allow but do not refresh timeout */
if (ignore)
return NF_ACCEPT;
timeouts = nf_ct_timeout_lookup(ct);
if (!timeouts)
timeouts = nf_sctp_pernet(nf_ct_net(ct))->timeouts;
nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
return NF_ACCEPT;
out_unlock:
spin_unlock_bh(&ct->lock);
out:
return -NF_ACCEPT;
}
static bool sctp_can_early_drop(const struct nf_conn *ct)
{
switch (ct->proto.sctp.state) {
case SCTP_CONNTRACK_SHUTDOWN_SENT:
case SCTP_CONNTRACK_SHUTDOWN_RECD:
case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT:
return true;
default:
break;
}
return false;
}
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
struct nf_conn *ct, bool destroy)
{
struct nlattr *nest_parms;
spin_lock_bh(&ct->lock);
nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP);
if (!nest_parms)
goto nla_put_failure;
if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state))
goto nla_put_failure;
if (destroy)
goto skip_state;
if (nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
goto nla_put_failure;
skip_state:
spin_unlock_bh(&ct->lock);
nla_nest_end(skb, nest_parms);
return 0;
nla_put_failure:
spin_unlock_bh(&ct->lock);
return -1;
}
static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
[CTA_PROTOINFO_SCTP_STATE] = { .type = NLA_U8 },
[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] = { .type = NLA_U32 },
[CTA_PROTOINFO_SCTP_VTAG_REPLY] = { .type = NLA_U32 },
};
#define SCTP_NLATTR_SIZE ( \
NLA_ALIGN(NLA_HDRLEN + 1) + \
NLA_ALIGN(NLA_HDRLEN + 4) + \
NLA_ALIGN(NLA_HDRLEN + 4))
static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
{
struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
int err;
/* updates may not contain the internal protocol info, skip parsing */
if (!attr)
return 0;
err = nla_parse_nested_deprecated(tb, CTA_PROTOINFO_SCTP_MAX, attr,
sctp_nla_policy, NULL);
if (err < 0)
return err;
if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
!tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
!tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
return -EINVAL;
spin_lock_bh(&ct->lock);
ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
spin_unlock_bh(&ct->lock);
return 0;
}
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_cttimeout.h>
static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
struct net *net, void *data)
{
unsigned int *timeouts = data;
struct nf_sctp_net *sn = nf_sctp_pernet(net);
int i;
if (!timeouts)
timeouts = sn->timeouts;
/* set default SCTP timeouts. */
for (i=0; i<SCTP_CONNTRACK_MAX; i++)
timeouts[i] = sn->timeouts[i];
/* there's a 1:1 mapping between attributes and protocol states. */
for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
if (tb[i]) {
timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
}
}
timeouts[CTA_TIMEOUT_SCTP_UNSPEC] = timeouts[CTA_TIMEOUT_SCTP_CLOSED];
return 0;
}
static int
sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
{
const unsigned int *timeouts = data;
int i;
for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -ENOSPC;
}
static const struct nla_policy
sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
[CTA_TIMEOUT_SCTP_CLOSED] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_COOKIE_WAIT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_COOKIE_ECHOED] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_ESTABLISHED] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_SHUTDOWN_SENT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_SHUTDOWN_RECD] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_HEARTBEAT_SENT] = { .type = NLA_U32 },
[CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED] = { .type = NLA_U32 },
};
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
void nf_conntrack_sctp_init_net(struct net *net)
{
struct nf_sctp_net *sn = nf_sctp_pernet(net);
int i;
for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
sn->timeouts[i] = sctp_timeouts[i];
/* timeouts[0] is unused, init it so ->timeouts[0] contains
* 'new' timeout, like udp or icmp.
*/
sn->timeouts[0] = sctp_timeouts[SCTP_CONNTRACK_CLOSED];
}
const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp = {
.l4proto = IPPROTO_SCTP,
#ifdef CONFIG_NF_CONNTRACK_PROCFS
.print_conntrack = sctp_print_conntrack,
#endif
.can_early_drop = sctp_can_early_drop,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.nlattr_size = SCTP_NLATTR_SIZE,
.to_nlattr = sctp_to_nlattr,
.from_nlattr = nlattr_to_sctp,
.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
.nla_policy = nf_ct_port_nla_policy,
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
.ctnl_timeout = {
.nlattr_to_obj = sctp_timeout_nlattr_to_obj,
.obj_to_nlattr = sctp_timeout_obj_to_nlattr,
.nlattr_max = CTA_TIMEOUT_SCTP_MAX,
.obj_size = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
.nla_policy = sctp_timeout_nla_policy,
},
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
};
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