From 5b92b61f3891517d18d0573ad2c939c81b59ecfe Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 22 Sep 2010 08:34:12 +0200 Subject: netfilter: nf_nat: better error handling of nf_ct_expect_related() in helpers This patch improves the situation in which the expectation table is full for conntrack NAT helpers. Basically, we give up if we don't find a place in the table instead of looping over nf_ct_expect_related() with a different port (we should only do this if it returns -EBUSY, for -EMFILE or -ESHUTDOWN I think that it's better to skip this). Signed-off-by: Pablo Neira Ayuso Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/nf_nat_amanda.c | 9 ++++++- net/ipv4/netfilter/nf_nat_ftp.c | 9 ++++++- net/ipv4/netfilter/nf_nat_h323.c | 53 +++++++++++++++++++++++++++++++++----- net/ipv4/netfilter/nf_nat_irc.c | 9 ++++++- net/ipv4/netfilter/nf_nat_sip.c | 27 ++++++++++++++++--- 5 files changed, 93 insertions(+), 14 deletions(-) diff --git a/net/ipv4/netfilter/nf_nat_amanda.c b/net/ipv4/netfilter/nf_nat_amanda.c index c31b876..0f23b3f 100644 --- a/net/ipv4/netfilter/nf_nat_amanda.c +++ b/net/ipv4/netfilter/nf_nat_amanda.c @@ -44,9 +44,16 @@ static unsigned int help(struct sk_buff *skb, /* Try to get same port: if not, try to change it. */ for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) { + int ret; + exp->tuple.dst.u.tcp.port = htons(port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + port = 0; break; + } } if (port == 0) diff --git a/net/ipv4/netfilter/nf_nat_ftp.c b/net/ipv4/netfilter/nf_nat_ftp.c index 86e0e84..dc73abb 100644 --- a/net/ipv4/netfilter/nf_nat_ftp.c +++ b/net/ipv4/netfilter/nf_nat_ftp.c @@ -79,9 +79,16 @@ static unsigned int nf_nat_ftp(struct sk_buff *skb, /* Try to get same port: if not, try to change it. */ for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) { + int ret; + exp->tuple.dst.u.tcp.port = htons(port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + port = 0; break; + } } if (port == 0) diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c index 5045196..790f316 100644 --- a/net/ipv4/netfilter/nf_nat_h323.c +++ b/net/ipv4/netfilter/nf_nat_h323.c @@ -222,13 +222,24 @@ static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct, /* Try to get a pair of ports. */ for (nated_port = ntohs(rtp_exp->tuple.dst.u.udp.port); nated_port != 0; nated_port += 2) { + int ret; + rtp_exp->tuple.dst.u.udp.port = htons(nated_port); - if (nf_ct_expect_related(rtp_exp) == 0) { + ret = nf_ct_expect_related(rtp_exp); + if (ret == 0) { rtcp_exp->tuple.dst.u.udp.port = htons(nated_port + 1); - if (nf_ct_expect_related(rtcp_exp) == 0) + ret = nf_ct_expect_related(rtcp_exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + nf_ct_unexpect_related(rtp_exp); + nated_port = 0; break; - nf_ct_unexpect_related(rtp_exp); + } + } else if (ret != -EBUSY) { + nated_port = 0; + break; } } @@ -284,9 +295,16 @@ static int nat_t120(struct sk_buff *skb, struct nf_conn *ct, /* Try to get same port: if not, try to change it. */ for (; nated_port != 0; nated_port++) { + int ret; + exp->tuple.dst.u.tcp.port = htons(nated_port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + nated_port = 0; break; + } } if (nated_port == 0) { /* No port available */ @@ -334,9 +352,16 @@ static int nat_h245(struct sk_buff *skb, struct nf_conn *ct, /* Try to get same port: if not, try to change it. */ for (; nated_port != 0; nated_port++) { + int ret; + exp->tuple.dst.u.tcp.port = htons(nated_port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) break; + else if (ret != -EBUSY) { + nated_port = 0; + break; + } } if (nated_port == 0) { /* No port available */ @@ -418,9 +443,16 @@ static int nat_q931(struct sk_buff *skb, struct nf_conn *ct, /* Try to get same port: if not, try to change it. */ for (; nated_port != 0; nated_port++) { + int ret; + exp->tuple.dst.u.tcp.port = htons(nated_port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + nated_port = 0; break; + } } if (nated_port == 0) { /* No port available */ @@ -500,9 +532,16 @@ static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct, /* Try to get same port: if not, try to change it. */ for (nated_port = ntohs(port); nated_port != 0; nated_port++) { + int ret; + exp->tuple.dst.u.tcp.port = htons(nated_port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) break; + else if (ret != -EBUSY) { + nated_port = 0; + break; + } } if (nated_port == 0) { /* No port available */ diff --git a/net/ipv4/netfilter/nf_nat_irc.c b/net/ipv4/netfilter/nf_nat_irc.c index ea83a88..535e1a8 100644 --- a/net/ipv4/netfilter/nf_nat_irc.c +++ b/net/ipv4/netfilter/nf_nat_irc.c @@ -45,9 +45,16 @@ static unsigned int help(struct sk_buff *skb, /* Try to get same port: if not, try to change it. */ for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) { + int ret; + exp->tuple.dst.u.tcp.port = htons(port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + port = 0; break; + } } if (port == 0) diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c index 11b538d..e40cf78 100644 --- a/net/ipv4/netfilter/nf_nat_sip.c +++ b/net/ipv4/netfilter/nf_nat_sip.c @@ -307,9 +307,16 @@ static unsigned int ip_nat_sip_expect(struct sk_buff *skb, unsigned int dataoff, exp->expectfn = ip_nat_sip_expected; for (; port != 0; port++) { + int ret; + exp->tuple.dst.u.udp.port = htons(port); - if (nf_ct_expect_related(exp) == 0) + ret = nf_ct_expect_related(exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + port = 0; break; + } } if (port == 0) @@ -480,13 +487,25 @@ static unsigned int ip_nat_sdp_media(struct sk_buff *skb, unsigned int dataoff, /* Try to get same pair of ports: if not, try to change them. */ for (port = ntohs(rtp_exp->tuple.dst.u.udp.port); port != 0; port += 2) { + int ret; + rtp_exp->tuple.dst.u.udp.port = htons(port); - if (nf_ct_expect_related(rtp_exp) != 0) + ret = nf_ct_expect_related(rtp_exp); + if (ret == -EBUSY) continue; + else if (ret < 0) { + port = 0; + break; + } rtcp_exp->tuple.dst.u.udp.port = htons(port + 1); - if (nf_ct_expect_related(rtcp_exp) == 0) + ret = nf_ct_expect_related(rtcp_exp); + if (ret == 0) break; - nf_ct_unexpect_related(rtp_exp); + else if (ret != -EBUSY) { + nf_ct_unexpect_related(rtp_exp); + port = 0; + break; + } } if (port == 0) -- cgit v1.1