Skip to content

Commit

Permalink
netfilter: conntrack: unify established states for SCTP paths
Browse files Browse the repository at this point in the history 
commit a44b765 upstream.

An SCTP endpoint can start an association through a path and tear it
down over another one. That means the initial path will not see the
shutdown sequence, and the conntrack entry will remain in ESTABLISHED
state for 5 days.

By merging the HEARTBEAT_ACKED and ESTABLISHED states into one
ESTABLISHED state, there remains no difference between a primary or
secondary path. The timeout for the merged ESTABLISHED state is set to
210 seconds (hb_interval * max_path_retrans + rto_max). So, even if a
path doesn't see the shutdown sequence, it will expire in a reasonable
amount of time.

With this change in place, there is now more than one state from which
we can transition to ESTABLISHED, COOKIE_ECHOED and HEARTBEAT_SENT, so
handle the setting of ASSURED bit whenever a state change has happened
and the new state is ESTABLISHED. Removed the check for dir==REPLY since
the transition to ESTABLISHED can happen only in the reply direction.

Fixes: 9fb9cbb ("[NETFILTER]: Add nf_conntrack subsystem.")
Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  • Loading branch information
@gregkh
Sriram Yagnaraman authored and gregkh committed Feb 1, 2023
1 parent 70654f9 commit dc1ccb4
Show file tree
Hide file tree
Showing 4 changed files with 41 additions and 64 deletions.
2 changes: 1 addition & 1 deletion include/uapi/linux/netfilter/nf_conntrack_sctp.h
View file
Expand Up @@ -15,7 +15,7 @@ enum sctp_conntrack {
SCTP_CONNTRACK_SHUTDOWN_RECD,
SCTP_CONNTRACK_SHUTDOWN_ACK_SENT,
SCTP_CONNTRACK_HEARTBEAT_SENT,
SCTP_CONNTRACK_HEARTBEAT_ACKED,
SCTP_CONNTRACK_HEARTBEAT_ACKED, /* no longer used */
SCTP_CONNTRACK_MAX
};

Expand Down
2 changes: 1 addition & 1 deletion include/uapi/linux/netfilter/nfnetlink_cttimeout.h
View file
Expand Up @@ -94,7 +94,7 @@ enum ctattr_timeout_sctp {
CTA_TIMEOUT_SCTP_SHUTDOWN_RECD,
CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT,
CTA_TIMEOUT_SCTP_HEARTBEAT_SENT,
CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED,
CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED, /* no longer used */
__CTA_TIMEOUT_SCTP_MAX
};
#define CTA_TIMEOUT_SCTP_MAX (__CTA_TIMEOUT_SCTP_MAX - 1)
Expand Down
93 changes: 39 additions & 54 deletions net/netfilter/nf_conntrack_proto_sctp.c
View file
Expand Up @@ -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
Expand All @@ -54,12 +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,
};

#define SCTP_FLAG_HEARTBEAT_VTAG_FAILED 1
Expand All @@ -73,7 +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 sIV SCTP_CONNTRACK_MAX

/*
Expand All @@ -96,9 +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 in the direction opposite to
that of the HEARTBEAT chunk. Secondary connection is
established.
*/

/* TODO
Expand All @@ -115,33 +104,33 @@ cookie echoed to closed.
static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
{
/* ORIGINAL */
/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
/* init */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA},
/* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},
/* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
/* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS},
/* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA},
/* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/
/* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */
/* cookie_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */
/* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA},
/* heartbeat */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
/* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}
/* 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 */
/* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */
/* init_ack */ {sIV, sCW, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},
/* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL},
/* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR},
/* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA},
/* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA},
/* cookie_echo */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */
/* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA},
/* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA},
/* heartbeat */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
/* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, 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},
}
};

Expand Down Expand Up @@ -508,8 +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);

Expand All @@ -523,14 +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:
Expand Down
8 changes: 0 additions & 8 deletions net/netfilter/nf_conntrack_standalone.c
View file
Expand Up @@ -601,7 +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,
#endif
#ifdef CONFIG_NF_CT_PROTO_DCCP
NF_SYSCTL_CT_PROTO_TIMEOUT_DCCP_REQUEST,
Expand Down Expand Up @@ -886,12 +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,
},
#endif
#ifdef CONFIG_NF_CT_PROTO_DCCP
[NF_SYSCTL_CT_PROTO_TIMEOUT_DCCP_REQUEST] = {
Expand Down Expand Up @@ -1035,7 +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);
#undef XASSIGN
#endif
}
Expand Down

0 comments on commit dc1ccb4

Please sign in to comment.