Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

1) Perform SCTP vtag verification for ABORT/SHUTDOWN_COMPLETE according
   to RFC 9260, Sect 8.5.1.

2) Fix infinite loop if SCTP chunk size is zero in for_each_sctp_chunk().
   And remove useless check in this macro too.

3) Revert DATA_SENT state in the SCTP tracker, this was applied in the
   previous merge window. Next patch in this series provides a more
   simple approach to multihoming support.

4) Unify HEARTBEAT_ACKED and ESTABLISHED states for SCTP multihoming
   support, use default ESTABLISHED of 210 seconds based on
   heartbeat timeout * maximum number of retransmission + round-trip timeout.
   Otherwise, SCTP conntrack entry that represents secondary paths
   remain stale in the table for up to 5 days.

This is a slightly large batch with fixes for the SCTP connection
tracking helper, all patches from Sriram Yagnaraman.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: conntrack: unify established states for SCTP paths
  Revert "netfilter: conntrack: add sctp DATA_SENT state"
  netfilter: conntrack: fix bug in for_each_sctp_chunk
  netfilter: conntrack: fix vtag checks for ABORT/SHUTDOWN_COMPLETE
====================

Link: https://lore.kernel.org/r/20230124183933.4752-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 72 insertions, 114 deletions

diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index d88b92a8ffca..945dd40e7077 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -27,22 +27,16 @@
 #include <net/netfilter/nf_conntrack_ecache.h>
 #include <net/netfilter/nf_conntrack_timeout.h>
 
-/* FIXME: Examine ipfilter's timeouts and conntrack transitions more
-   closely.  They're more complex. --RR
-
-   And so for me for SCTP :D -Kiran */
-
 static const char *const sctp_conntrack_names[] = {
-	"NONE",
-	"CLOSED",
-	"COOKIE_WAIT",
-	"COOKIE_ECHOED",
-	"ESTABLISHED",
-	"SHUTDOWN_SENT",
-	"SHUTDOWN_RECD",
-	"SHUTDOWN_ACK_SENT",
-	"HEARTBEAT_SENT",
-	"HEARTBEAT_ACKED",
+	[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
@@ -54,13 +48,11 @@ 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]		= 5 DAYS,
+	[SCTP_CONNTRACK_ESTABLISHED]		= 210 SECS,
 	[SCTP_CONNTRACK_SHUTDOWN_SENT]		= 300 SECS / 1000,
 	[SCTP_CONNTRACK_SHUTDOWN_RECD]		= 300 SECS / 1000,
 	[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT]	= 3 SECS,
 	[SCTP_CONNTRACK_HEARTBEAT_SENT]		= 30 SECS,
-	[SCTP_CONNTRACK_HEARTBEAT_ACKED]	= 210 SECS,
-	[SCTP_CONNTRACK_DATA_SENT]		= 30 SECS,
 };
 
 #define	SCTP_FLAG_HEARTBEAT_VTAG_FAILED	1
@@ -74,8 +66,6 @@ static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = {
 #define	sSR SCTP_CONNTRACK_SHUTDOWN_RECD
 #define	sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
 #define	sHS SCTP_CONNTRACK_HEARTBEAT_SENT
-#define	sHA SCTP_CONNTRACK_HEARTBEAT_ACKED
-#define	sDS SCTP_CONNTRACK_DATA_SENT
 #define	sIV SCTP_CONNTRACK_MAX
 
 /*
@@ -98,10 +88,6 @@ SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
 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.
-HEARTBEAT_ACKED   - We have seen a HEARTBEAT-ACK/DATA/SACK in the direction
-		    opposite to that of the HEARTBEAT/DATA chunk. Secondary connection
-		    is established.
-DATA_SENT         - We have seen a DATA/SACK in a new flow.
 */
 
 /* TODO
@@ -115,38 +101,36 @@ cookie echoed to closed.
 */
 
 /* SCTP conntrack state transitions */
-static const u8 sctp_conntracks[2][12][SCTP_CONNTRACK_MAX] = {
+static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
 	{
 /*	ORIGINAL	*/
-/*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA, sDS */
-/* init         */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA, sCW},
-/* init_ack     */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA, sCL},
-/* abort        */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
-/* shutdown     */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS, sCL},
-/* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA, sSA},
-/* error        */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA, sCL},/* Can't have Stale cookie*/
-/* cookie_echo  */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA, sCL},/* 5.2.4 - Big TODO */
-/* cookie_ack   */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA, sCL},/* Can't come in orig dir */
-/* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA, sCL},
-/* heartbeat    */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA, sDS},
-/* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA, sDS},
-/* data/sack    */ {sDS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA, sDS}
+/*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS */
+/* init         */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, 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, sHA, sDS */
-/* init         */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA, sIV},/* INIT in sCL Big TODO */
-/* init_ack     */ {sIV, sCW, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA, sIV},
-/* abort        */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL, sIV},
-/* shutdown     */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR, sIV},
-/* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA, sIV},
-/* error        */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA, sIV},
-/* cookie_echo  */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA, sIV},/* Can't come in reply dir */
-/* cookie_ack   */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA, sIV},
-/* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA, sIV},
-/* heartbeat    */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA, sHA},
-/* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA, sHA},
-/* data/sack    */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA, sHA},
+/*                  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},
 	}
 };
 
@@ -160,8 +144,8 @@ static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 
 #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)));	\
+	((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))) &&	\
+	(sch)->length;	\
 	(offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 
 /* Some validity checks to make sure the chunks are fine */
@@ -258,11 +242,6 @@ static int sctp_new_state(enum ip_conntrack_dir dir,
 		pr_debug("SCTP_CID_HEARTBEAT_ACK");
 		i = 10;
 		break;
-	case SCTP_CID_DATA:
-	case SCTP_CID_SACK:
-		pr_debug("SCTP_CID_DATA/SACK");
-		i = 11;
-		break;
 	default:
 		/* Other chunks like DATA or SACK do not change the state */
 		pr_debug("Unknown chunk type, Will stay in %s\n",
@@ -316,9 +295,7 @@ sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 				 ih->init_tag);
 
 			ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag;
-		} else if (sch->type == SCTP_CID_HEARTBEAT ||
-			   sch->type == SCTP_CID_DATA ||
-			   sch->type == SCTP_CID_SACK) {
+		} 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;
@@ -404,19 +381,19 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 
 		if (!sctp_new(ct, skb, sh, dataoff))
 			return -NF_ACCEPT;
-	} else {
-		/* 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]) {
-			pr_debug("Verification tag check failed\n");
-			goto out;
-		}
+	}
+
+	/* 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]) {
+		pr_debug("Verification tag check failed\n");
+		goto out;
 	}
 
 	old_state = new_state = SCTP_CONNTRACK_NONE;
@@ -424,22 +401,29 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 	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) {
-			/* Sec 8.5.1 (A) */
+			/* (A) vtag MUST be zero */
 			if (sh->vtag != 0)
 				goto out_unlock;
 		} else if (sch->type == SCTP_CID_ABORT) {
-			/* Sec 8.5.1 (B) */
-			if (sh->vtag != ct->proto.sctp.vtag[dir] &&
-			    sh->vtag != ct->proto.sctp.vtag[!dir])
+			/* (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) {
-			/* Sec 8.5.1 (C) */
-			if (sh->vtag != ct->proto.sctp.vtag[dir] &&
-			    sh->vtag != ct->proto.sctp.vtag[!dir] &&
-			    sch->flags & SCTP_CHUNK_FLAG_T)
+			/* (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) {
-			/* Sec 8.5.1 (D) */
+			/* (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) {
@@ -476,11 +460,6 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 			} 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_DATA || sch->type == SCTP_CID_SACK) {
-			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;
-			}
 		}
 
 		old_state = ct->proto.sctp.state;
@@ -518,8 +497,12 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 		}
 
 		ct->proto.sctp.state = new_state;
-		if (old_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);
 
@@ -533,14 +516,6 @@ int nf_conntrack_sctp_packet(struct nf_conn *ct,
 
 	nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 
-	if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
-	    dir == IP_CT_DIR_REPLY &&
-	    new_state == SCTP_CONNTRACK_ESTABLISHED) {
-		pr_debug("Setting assured bit\n");
-		set_bit(IPS_ASSURED_BIT, &ct->status);
-		nf_conntrack_event_cache(IPCT_ASSURED, ct);
-	}
-
 	return NF_ACCEPT;
 
 out_unlock:
@@ -701,7 +676,6 @@ sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
 	[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 },
-	[CTA_TIMEOUT_SCTP_DATA_SENT]		= { .type = NLA_U32 },
 };
 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 0250725e38a4..460294bd4b60 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -601,8 +601,6 @@ enum nf_ct_sysctl_index {
 	NF_SYSCTL_CT_PROTO_TIMEOUT_SCTP_SHUTDOWN_RECD,
 	NF_SYSCTL_CT_PROTO_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT,
 	NF_SYSCTL_CT_PROTO_TIMEOUT_SCTP_HEARTBEAT_SENT,
-	NF_SYSCTL_CT_PROTO_TIMEOUT_SCTP_HEARTBEAT_ACKED,
-	NF_SYSCTL_CT_PROTO_TIMEOUT_SCTP_DATA_SENT,
 #endif
 #ifdef CONFIG_NF_CT_PROTO_DCCP
 	NF_SYSCTL_CT_PROTO_TIMEOUT_DCCP_REQUEST,
@@ -887,18 +885,6 @@ static struct ctl_table nf_ct_sysctl_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_jiffies,
 	},
-	[NF_SYSCTL_CT_PROTO_TIMEOUT_SCTP_HEARTBEAT_ACKED] = {
-		.procname       = "nf_conntrack_sctp_timeout_heartbeat_acked",
-		.maxlen         = sizeof(unsigned int),
-		.mode           = 0644,
-		.proc_handler   = proc_dointvec_jiffies,
-	},
-	[NF_SYSCTL_CT_PROTO_TIMEOUT_SCTP_DATA_SENT] = {
-		.procname       = "nf_conntrack_sctp_timeout_data_sent",
-		.maxlen         = sizeof(unsigned int),
-		.mode           = 0644,
-		.proc_handler   = proc_dointvec_jiffies,
-	},
 #endif
 #ifdef CONFIG_NF_CT_PROTO_DCCP
 	[NF_SYSCTL_CT_PROTO_TIMEOUT_DCCP_REQUEST] = {
@@ -1042,8 +1028,6 @@ static void nf_conntrack_standalone_init_sctp_sysctl(struct net *net,
 	XASSIGN(SHUTDOWN_RECD, sn);
 	XASSIGN(SHUTDOWN_ACK_SENT, sn);
 	XASSIGN(HEARTBEAT_SENT, sn);
-	XASSIGN(HEARTBEAT_ACKED, sn);
-	XASSIGN(DATA_SENT, sn);
 #undef XASSIGN
 #endif
 }