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6e348067ee
The annotation says in sctp_new(): "If it is a shutdown ack OOTB packet, we expect a return shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8)". However, it does not check SCTP_CID_SHUTDOWN_ACK before setting vtag[REPLY] in the conntrack entry(ct). Because of that, if the ct in Router disappears for some reason in [1] with the packet sequence like below: Client > Server: sctp (1) [INIT] [init tag: 3201533963] Server > Client: sctp (1) [INIT ACK] [init tag: 972498433] Client > Server: sctp (1) [COOKIE ECHO] Server > Client: sctp (1) [COOKIE ACK] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057809] Server > Client: sctp (1) [SACK] [cum ack 3075057809] Server > Client: sctp (1) [HB REQ] (the ct in Router disappears somehow) <-------- [1] Client > Server: sctp (1) [HB ACK] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057810] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057810] Client > Server: sctp (1) [HB REQ] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057810] Client > Server: sctp (1) [HB REQ] Client > Server: sctp (1) [ABORT] when processing HB ACK packet in Router it calls sctp_new() to initialize the new ct with vtag[REPLY] set to HB_ACK packet's vtag. Later when sending DATA from Client, all the SACKs from Server will get dropped in Router, as the SACK packet's vtag does not match vtag[REPLY] in the ct. The worst thing is the vtag in this ct will never get fixed by the upcoming packets from Server. This patch fixes it by checking SCTP_CID_SHUTDOWN_ACK before setting vtag[REPLY] in the ct in sctp_new() as the annotation says. With this fix, it will leave vtag[REPLY] in ct to 0 in the case above, and the next HB REQ/ACK from Server is able to fix the vtag as its value is 0 in nf_conntrack_sctp_packet(). Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
730 lines
22 KiB
C
730 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Connection tracking protocol helper module for SCTP.
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*
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* Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
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* Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
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*
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* SCTP is defined in RFC 2960. References to various sections in this code
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* are to this RFC.
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*/
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#include <linux/types.h>
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#include <linux/timer.h>
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#include <linux/netfilter.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <linux/sctp.h>
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#include <linux/string.h>
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#include <linux/seq_file.h>
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#include <linux/spinlock.h>
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#include <linux/interrupt.h>
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#include <net/sctp/checksum.h>
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#include <net/netfilter/nf_log.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
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#include <net/netfilter/nf_conntrack_timeout.h>
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static const char *const sctp_conntrack_names[] = {
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[SCTP_CONNTRACK_NONE] = "NONE",
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[SCTP_CONNTRACK_CLOSED] = "CLOSED",
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[SCTP_CONNTRACK_COOKIE_WAIT] = "COOKIE_WAIT",
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[SCTP_CONNTRACK_COOKIE_ECHOED] = "COOKIE_ECHOED",
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[SCTP_CONNTRACK_ESTABLISHED] = "ESTABLISHED",
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[SCTP_CONNTRACK_SHUTDOWN_SENT] = "SHUTDOWN_SENT",
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[SCTP_CONNTRACK_SHUTDOWN_RECD] = "SHUTDOWN_RECD",
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[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = "SHUTDOWN_ACK_SENT",
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[SCTP_CONNTRACK_HEARTBEAT_SENT] = "HEARTBEAT_SENT",
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};
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#define SECS * HZ
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#define MINS * 60 SECS
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#define HOURS * 60 MINS
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#define DAYS * 24 HOURS
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static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = {
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[SCTP_CONNTRACK_CLOSED] = 10 SECS,
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[SCTP_CONNTRACK_COOKIE_WAIT] = 3 SECS,
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[SCTP_CONNTRACK_COOKIE_ECHOED] = 3 SECS,
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[SCTP_CONNTRACK_ESTABLISHED] = 210 SECS,
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[SCTP_CONNTRACK_SHUTDOWN_SENT] = 3 SECS,
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[SCTP_CONNTRACK_SHUTDOWN_RECD] = 3 SECS,
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[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = 3 SECS,
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[SCTP_CONNTRACK_HEARTBEAT_SENT] = 30 SECS,
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};
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#define SCTP_FLAG_HEARTBEAT_VTAG_FAILED 1
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#define sNO SCTP_CONNTRACK_NONE
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#define sCL SCTP_CONNTRACK_CLOSED
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#define sCW SCTP_CONNTRACK_COOKIE_WAIT
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#define sCE SCTP_CONNTRACK_COOKIE_ECHOED
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#define sES SCTP_CONNTRACK_ESTABLISHED
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#define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
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#define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
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#define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
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#define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
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#define sIV SCTP_CONNTRACK_MAX
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/*
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These are the descriptions of the states:
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NOTE: These state names are tantalizingly similar to the states of an
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SCTP endpoint. But the interpretation of the states is a little different,
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considering that these are the states of the connection and not of an end
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point. Please note the subtleties. -Kiran
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NONE - Nothing so far.
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COOKIE WAIT - We have seen an INIT chunk in the original direction, or also
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an INIT_ACK chunk in the reply direction.
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COOKIE ECHOED - We have seen a COOKIE_ECHO chunk in the original direction.
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ESTABLISHED - We have seen a COOKIE_ACK in the reply direction.
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SHUTDOWN_SENT - We have seen a SHUTDOWN chunk in the original direction.
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SHUTDOWN_RECD - We have seen a SHUTDOWN chunk in the reply direction.
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SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
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to that of the SHUTDOWN chunk.
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CLOSED - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
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the SHUTDOWN chunk. Connection is closed.
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HEARTBEAT_SENT - We have seen a HEARTBEAT in a new flow.
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*/
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/* TODO
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- I have assumed that the first INIT is in the original direction.
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This messes things when an INIT comes in the reply direction in CLOSED
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state.
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- Check the error type in the reply dir before transitioning from
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cookie echoed to closed.
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- Sec 5.2.4 of RFC 2960
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- Full Multi Homing support.
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*/
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/* SCTP conntrack state transitions */
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static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
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{
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/* ORIGINAL */
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/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS */
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/* init */ {sCL, sCL, sCW, sCE, sES, sCL, sCL, sSA, sCW},
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/* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},
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/* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
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/* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL},
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/* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA},
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/* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},/* Can't have Stale cookie*/
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/* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL},/* 5.2.4 - Big TODO */
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/* cookie_ack */ {sCL, sCL, sCW, sES, sES, sSS, sSR, sSA, sCL},/* Can't come in orig dir */
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/* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL},
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/* heartbeat */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
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/* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
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},
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{
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/* REPLY */
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/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS */
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/* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV},/* INIT in sCL Big TODO */
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/* init_ack */ {sIV, sCW, sCW, sCE, sES, sSS, sSR, sSA, sIV},
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/* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV},
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/* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV},
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/* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV},
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/* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV},
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/* cookie_echo */ {sIV, sCL, sCE, sCE, sES, sSS, sSR, sSA, sIV},/* Can't come in reply dir */
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/* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV},
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/* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV},
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/* heartbeat */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS},
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/* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sES},
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}
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};
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#ifdef CONFIG_NF_CONNTRACK_PROCFS
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/* Print out the private part of the conntrack. */
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static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
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{
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seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]);
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}
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#endif
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/* do_basic_checks ensures sch->length > 0, do not use before */
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#define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \
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for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0; \
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(offset) < (skb)->len && \
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((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \
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(offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
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/* Some validity checks to make sure the chunks are fine */
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static int do_basic_checks(struct nf_conn *ct,
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const struct sk_buff *skb,
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unsigned int dataoff,
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unsigned long *map,
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const struct nf_hook_state *state)
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{
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u_int32_t offset, count;
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struct sctp_chunkhdr _sch, *sch;
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int flag;
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flag = 0;
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for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
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if (sch->type == SCTP_CID_INIT ||
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sch->type == SCTP_CID_INIT_ACK ||
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sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
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flag = 1;
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/*
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* Cookie Ack/Echo chunks not the first OR
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* Init / Init Ack / Shutdown compl chunks not the only chunks
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* OR zero-length.
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*/
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if (((sch->type == SCTP_CID_COOKIE_ACK ||
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sch->type == SCTP_CID_COOKIE_ECHO ||
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flag) &&
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count != 0) || !sch->length) {
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nf_ct_l4proto_log_invalid(skb, ct, state,
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"%s failed. chunk num %d, type %d, len %d flag %d\n",
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__func__, count, sch->type, sch->length, flag);
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return 1;
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}
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if (map)
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set_bit(sch->type, map);
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}
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return count == 0;
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}
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static int sctp_new_state(enum ip_conntrack_dir dir,
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enum sctp_conntrack cur_state,
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int chunk_type)
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{
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int i;
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switch (chunk_type) {
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case SCTP_CID_INIT:
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i = 0;
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break;
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case SCTP_CID_INIT_ACK:
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i = 1;
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break;
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case SCTP_CID_ABORT:
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i = 2;
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break;
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case SCTP_CID_SHUTDOWN:
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i = 3;
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break;
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case SCTP_CID_SHUTDOWN_ACK:
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i = 4;
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break;
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case SCTP_CID_ERROR:
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i = 5;
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break;
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case SCTP_CID_COOKIE_ECHO:
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i = 6;
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break;
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case SCTP_CID_COOKIE_ACK:
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i = 7;
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break;
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case SCTP_CID_SHUTDOWN_COMPLETE:
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i = 8;
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break;
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case SCTP_CID_HEARTBEAT:
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i = 9;
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break;
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case SCTP_CID_HEARTBEAT_ACK:
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i = 10;
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break;
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default:
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/* Other chunks like DATA or SACK do not change the state */
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pr_debug("Unknown chunk type %d, Will stay in %s\n",
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chunk_type, sctp_conntrack_names[cur_state]);
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return cur_state;
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}
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return sctp_conntracks[dir][i][cur_state];
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}
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/* Don't need lock here: this conntrack not in circulation yet */
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static noinline bool
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sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
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const struct sctphdr *sh, unsigned int dataoff)
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{
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enum sctp_conntrack new_state;
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const struct sctp_chunkhdr *sch;
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struct sctp_chunkhdr _sch;
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u32 offset, count;
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memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
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new_state = SCTP_CONNTRACK_MAX;
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for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) {
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new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
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SCTP_CONNTRACK_NONE, sch->type);
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/* Invalid: delete conntrack */
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if (new_state == SCTP_CONNTRACK_NONE ||
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new_state == SCTP_CONNTRACK_MAX) {
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pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
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return false;
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}
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/* Copy the vtag into the state info */
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if (sch->type == SCTP_CID_INIT) {
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struct sctp_inithdr _inithdr, *ih;
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/* Sec 8.5.1 (A) */
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if (sh->vtag)
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return false;
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ih = skb_header_pointer(skb, offset + sizeof(_sch),
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sizeof(_inithdr), &_inithdr);
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if (!ih)
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return false;
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pr_debug("Setting vtag %x for new conn\n",
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ih->init_tag);
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ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag;
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} else if (sch->type == SCTP_CID_HEARTBEAT) {
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pr_debug("Setting vtag %x for secondary conntrack\n",
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sh->vtag);
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ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
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} else if (sch->type == SCTP_CID_SHUTDOWN_ACK) {
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/* If it is a shutdown ack OOTB packet, we expect a return
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shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
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pr_debug("Setting vtag %x for new conn OOTB\n",
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sh->vtag);
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ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
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}
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ct->proto.sctp.state = SCTP_CONNTRACK_NONE;
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}
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return true;
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}
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static bool sctp_error(struct sk_buff *skb,
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unsigned int dataoff,
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const struct nf_hook_state *state)
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{
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const struct sctphdr *sh;
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const char *logmsg;
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if (skb->len < dataoff + sizeof(struct sctphdr)) {
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logmsg = "nf_ct_sctp: short packet ";
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goto out_invalid;
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}
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if (state->hook == NF_INET_PRE_ROUTING &&
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state->net->ct.sysctl_checksum &&
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skb->ip_summed == CHECKSUM_NONE) {
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if (skb_ensure_writable(skb, dataoff + sizeof(*sh))) {
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logmsg = "nf_ct_sctp: failed to read header ";
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goto out_invalid;
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}
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sh = (const struct sctphdr *)(skb->data + dataoff);
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if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
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logmsg = "nf_ct_sctp: bad CRC ";
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goto out_invalid;
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}
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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}
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return false;
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out_invalid:
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nf_l4proto_log_invalid(skb, state, IPPROTO_SCTP, "%s", logmsg);
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return true;
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}
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/* Returns verdict for packet, or -NF_ACCEPT for invalid. */
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int nf_conntrack_sctp_packet(struct nf_conn *ct,
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struct sk_buff *skb,
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unsigned int dataoff,
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enum ip_conntrack_info ctinfo,
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const struct nf_hook_state *state)
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{
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enum sctp_conntrack new_state, old_state;
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enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
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const struct sctphdr *sh;
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struct sctphdr _sctph;
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const struct sctp_chunkhdr *sch;
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struct sctp_chunkhdr _sch;
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u_int32_t offset, count;
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unsigned int *timeouts;
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unsigned long map[256 / sizeof(unsigned long)] = { 0 };
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bool ignore = false;
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if (sctp_error(skb, dataoff, state))
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return -NF_ACCEPT;
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sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
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if (sh == NULL)
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goto out;
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if (do_basic_checks(ct, skb, dataoff, map, state) != 0)
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goto out;
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if (!nf_ct_is_confirmed(ct)) {
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/* If an OOTB packet has any of these chunks discard (Sec 8.4) */
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if (test_bit(SCTP_CID_ABORT, map) ||
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test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
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test_bit(SCTP_CID_COOKIE_ACK, map))
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return -NF_ACCEPT;
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if (!sctp_new(ct, skb, sh, dataoff))
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return -NF_ACCEPT;
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}
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/* Check the verification tag (Sec 8.5) */
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if (!test_bit(SCTP_CID_INIT, map) &&
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!test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
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!test_bit(SCTP_CID_COOKIE_ECHO, map) &&
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!test_bit(SCTP_CID_ABORT, map) &&
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!test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
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!test_bit(SCTP_CID_HEARTBEAT, map) &&
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!test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
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sh->vtag != ct->proto.sctp.vtag[dir]) {
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|
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_COOKIE_ACK) {
|
|
ct->proto.sctp.init[dir] = 0;
|
|
ct->proto.sctp.init[!dir] = 0;
|
|
} 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) {
|
|
struct sctp_inithdr _ih, *ih;
|
|
|
|
ih = skb_header_pointer(skb, offset + sizeof(_sch), sizeof(*ih), &_ih);
|
|
if (!ih)
|
|
goto out_unlock;
|
|
|
|
if (ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir])
|
|
ct->proto.sctp.init[!dir] = 0;
|
|
ct->proto.sctp.init[dir] = 1;
|
|
|
|
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;
|
|
} else if (sch->type == SCTP_CID_INIT_ACK) {
|
|
struct sctp_inithdr _ih, *ih;
|
|
__be32 vtag;
|
|
|
|
ih = skb_header_pointer(skb, offset + sizeof(_sch), sizeof(*ih), &_ih);
|
|
if (!ih)
|
|
goto out_unlock;
|
|
|
|
vtag = ct->proto.sctp.vtag[!dir];
|
|
if (!ct->proto.sctp.init[!dir] && vtag && vtag != ih->init_tag)
|
|
goto out_unlock;
|
|
/* collision */
|
|
if (ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir] &&
|
|
vtag != ih->init_tag)
|
|
goto out_unlock;
|
|
|
|
pr_debug("Setting vtag %x for dir %d\n", ih->init_tag, !dir);
|
|
ct->proto.sctp.vtag[!dir] = ih->init_tag;
|
|
}
|
|
|
|
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 */
|
|
};
|