From d901a9369e6e7d07a7eb4ddb315c6fcbaf8b24d3 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Tue, 25 Mar 2008 20:25:32 -0700 Subject: [PATCH] [NETFILTER]: nf_conntrack_sip: allow media expectations with wildcard source address Media streams can come from anywhere, add a module parameter which controls whether wildcard expectations or expectations between the two signalling endpoints are created. Since the same media description sent on multiple connections may results in multiple identical expections when using a wildcard source, we need to check whether a similar expectation already exists for a different connection before attempting to register it. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/netfilter/nf_conntrack_sip.c | 45 +++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 043aa557e7a8..813aa8c67e4c 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -42,6 +42,11 @@ module_param(sip_direct_signalling, int, 0600); MODULE_PARM_DESC(sip_direct_signalling, "expect incoming calls from registrar " "only (default 1)"); +static int sip_direct_media __read_mostly = 1; +module_param(sip_direct_media, int, 0600); +MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling " + "endpoints only (default 1)"); + unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, const char **dptr, unsigned int *datalen) __read_mostly; @@ -656,21 +661,53 @@ static void flush_expectations(struct nf_conn *ct, bool media) static int set_expected_rtp(struct sk_buff *skb, const char **dptr, unsigned int *datalen, - union nf_inet_addr *addr, __be16 port) + union nf_inet_addr *daddr, __be16 port) { struct nf_conntrack_expect *exp; enum ip_conntrack_info ctinfo; struct nf_conn *ct = nf_ct_get(skb, &ctinfo); enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + union nf_inet_addr *saddr; + struct nf_conntrack_tuple tuple; int family = ct->tuplehash[!dir].tuple.src.l3num; - int ret; + int skip_expect = 0, ret; typeof(nf_nat_sdp_hook) nf_nat_sdp; + saddr = NULL; + if (sip_direct_media) { + if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3)) + return NF_ACCEPT; + saddr = &ct->tuplehash[!dir].tuple.src.u3; + } + + /* We need to check whether the registration exists before attempting + * to register it since we can see the same media description multiple + * times on different connections in case multiple endpoints receive + * the same call. + */ + memset(&tuple, 0, sizeof(tuple)); + if (saddr) + tuple.src.u3 = *saddr; + tuple.src.l3num = family; + tuple.dst.protonum = IPPROTO_UDP; + tuple.dst.u3 = *daddr; + tuple.dst.u.udp.port = port; + + rcu_read_lock(); + exp = __nf_ct_expect_find(&tuple); + if (exp && exp->master != ct && + nfct_help(exp->master)->helper == nfct_help(ct)->helper && + exp->class == SIP_EXPECT_AUDIO) + skip_expect = 1; + rcu_read_unlock(); + + if (skip_expect) + return NF_ACCEPT; + exp = nf_ct_expect_alloc(ct); if (exp == NULL) return NF_DROP; - nf_ct_expect_init(exp, SIP_EXPECT_AUDIO, family, - &ct->tuplehash[!dir].tuple.src.u3, addr, + nf_ct_expect_init(exp, SIP_EXPECT_AUDIO, family, saddr, daddr, IPPROTO_UDP, NULL, &port); nf_nat_sdp = rcu_dereference(nf_nat_sdp_hook); -- 2.20.1