From e9324b2ce656e1910d2385b9b47a2f926456dbe3 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 9 Aug 2012 10:08:45 +0000 Subject: netfilter: nf_ct_sip: fix helper name Commit 3a8fc53a (netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names) introduced a bug in the SIP helper, the helper name is sprinted to the sip_names array instead of instead of into the helper structure. This breaks the helper match and the /proc/net/nf_conntrack_expect output. Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_sip.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 758a1bacc126..2fb666920cc9 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -1515,7 +1515,6 @@ static int sip_help_udp(struct sk_buff *skb, unsigned int protoff, } static struct nf_conntrack_helper sip[MAX_PORTS][4] __read_mostly; -static char sip_names[MAX_PORTS][4][sizeof("sip-65535")] __read_mostly; static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { [SIP_EXPECT_SIGNALLING] = { @@ -1585,9 +1584,9 @@ static int __init nf_conntrack_sip_init(void) sip[i][j].me = THIS_MODULE; if (ports[i] == SIP_PORT) - sprintf(sip_names[i][j], "sip"); + sprintf(sip[i][j].name, "sip"); else - sprintf(sip_names[i][j], "sip-%u", i); + sprintf(sip[i][j].name, "sip-%u", i); pr_debug("port #%u: %u\n", i, ports[i]); -- cgit v1.2.3 From 02b69cbdc2fb2e1bfbfd9ac0c246d7be1b08d3cd Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 9 Aug 2012 10:08:46 +0000 Subject: netfilter: nf_ct_sip: fix IPv6 address parsing Within SIP messages IPv6 addresses are enclosed in square brackets in most cases, with the exception of the "received=" header parameter. Currently the helper fails to parse enclosed addresses. This patch: - changes the SIP address parsing function to enforce square brackets when required, and accept them when not required but present, as recommended by RFC 5118. - adds a new SDP address parsing function that never accepts square brackets since SDP doesn't use them. With these changes, the SIP helper correctly parses all test messages from RFC 5118 (Session Initiation Protocol (SIP) Torture Test Messages for Internet Protocol Version 6 (IPv6)). Signed-off-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/nf_conntrack_sip.h | 2 +- net/ipv4/netfilter/nf_nat_sip.c | 4 +- net/netfilter/nf_conntrack_sip.c | 87 ++++++++++++++++++++++++------ 3 files changed, 73 insertions(+), 20 deletions(-) (limited to 'net/netfilter') diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h index 0dfc8b7210a3..89f2a627f3f0 100644 --- a/include/linux/netfilter/nf_conntrack_sip.h +++ b/include/linux/netfilter/nf_conntrack_sip.h @@ -164,7 +164,7 @@ extern int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr unsigned int dataoff, unsigned int datalen, const char *name, unsigned int *matchoff, unsigned int *matchlen, - union nf_inet_addr *addr); + union nf_inet_addr *addr, bool delim); extern int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr, unsigned int off, unsigned int datalen, const char *name, diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c index ea4a23813d26..eef8f29e8bf8 100644 --- a/net/ipv4/netfilter/nf_nat_sip.c +++ b/net/ipv4/netfilter/nf_nat_sip.c @@ -173,7 +173,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff, * the reply. */ if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen, "maddr=", &poff, &plen, - &addr) > 0 && + &addr, true) > 0 && addr.ip == ct->tuplehash[dir].tuple.src.u3.ip && addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) { buflen = sprintf(buffer, "%pI4", @@ -187,7 +187,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff, * from which the server received the request. */ if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen, "received=", &poff, &plen, - &addr) > 0 && + &addr, false) > 0 && addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip && addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) { buflen = sprintf(buffer, "%pI4", diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 2fb666920cc9..5c0a112aeee6 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -183,12 +183,12 @@ static int media_len(const struct nf_conn *ct, const char *dptr, return len + digits_len(ct, dptr, limit, shift); } -static int parse_addr(const struct nf_conn *ct, const char *cp, - const char **endp, union nf_inet_addr *addr, - const char *limit) +static int sip_parse_addr(const struct nf_conn *ct, const char *cp, + const char **endp, union nf_inet_addr *addr, + const char *limit, bool delim) { const char *end; - int ret = 0; + int ret; if (!ct) return 0; @@ -197,16 +197,28 @@ static int parse_addr(const struct nf_conn *ct, const char *cp, switch (nf_ct_l3num(ct)) { case AF_INET: ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); + if (ret == 0) + return 0; break; case AF_INET6: + if (cp < limit && *cp == '[') + cp++; + else if (delim) + return 0; + ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); + if (ret == 0) + return 0; + + if (end < limit && *end == ']') + end++; + else if (delim) + return 0; break; default: BUG(); } - if (ret == 0 || end == cp) - return 0; if (endp) *endp = end; return 1; @@ -219,7 +231,7 @@ static int epaddr_len(const struct nf_conn *ct, const char *dptr, union nf_inet_addr addr; const char *aux = dptr; - if (!parse_addr(ct, dptr, &dptr, &addr, limit)) { + if (!sip_parse_addr(ct, dptr, &dptr, &addr, limit, true)) { pr_debug("ip: %s parse failed.!\n", dptr); return 0; } @@ -296,7 +308,7 @@ int ct_sip_parse_request(const struct nf_conn *ct, return 0; dptr += shift; - if (!parse_addr(ct, dptr, &end, addr, limit)) + if (!sip_parse_addr(ct, dptr, &end, addr, limit, true)) return -1; if (end < limit && *end == ':') { end++; @@ -550,7 +562,7 @@ int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, if (ret == 0) return ret; - if (!parse_addr(ct, dptr + *matchoff, &c, addr, limit)) + if (!sip_parse_addr(ct, dptr + *matchoff, &c, addr, limit, true)) return -1; if (*c == ':') { c++; @@ -599,7 +611,7 @@ int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, unsigned int dataoff, unsigned int datalen, const char *name, unsigned int *matchoff, unsigned int *matchlen, - union nf_inet_addr *addr) + union nf_inet_addr *addr, bool delim) { const char *limit = dptr + datalen; const char *start, *end; @@ -613,7 +625,7 @@ int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, return 0; start += strlen(name); - if (!parse_addr(ct, start, &end, addr, limit)) + if (!sip_parse_addr(ct, start, &end, addr, limit, delim)) return 0; *matchoff = start - dptr; *matchlen = end - start; @@ -675,6 +687,47 @@ static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, return 1; } +static int sdp_parse_addr(const struct nf_conn *ct, const char *cp, + const char **endp, union nf_inet_addr *addr, + const char *limit) +{ + const char *end; + int ret; + + memset(addr, 0, sizeof(*addr)); + switch (nf_ct_l3num(ct)) { + case AF_INET: + ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); + break; + case AF_INET6: + ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); + break; + default: + BUG(); + } + + if (ret == 0) + return 0; + if (endp) + *endp = end; + return 1; +} + +/* skip ip address. returns its length. */ +static int sdp_addr_len(const struct nf_conn *ct, const char *dptr, + const char *limit, int *shift) +{ + union nf_inet_addr addr; + const char *aux = dptr; + + if (!sdp_parse_addr(ct, dptr, &dptr, &addr, limit)) { + pr_debug("ip: %s parse failed.!\n", dptr); + return 0; + } + + return dptr - aux; +} + /* SDP header parsing: a SDP session description contains an ordered set of * headers, starting with a section containing general session parameters, * optionally followed by multiple media descriptions. @@ -686,10 +739,10 @@ static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, */ static const struct sip_header ct_sdp_hdrs[] = { [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), - [SDP_HDR_OWNER_IP4] = SDP_HDR("o=", "IN IP4 ", epaddr_len), - [SDP_HDR_CONNECTION_IP4] = SDP_HDR("c=", "IN IP4 ", epaddr_len), - [SDP_HDR_OWNER_IP6] = SDP_HDR("o=", "IN IP6 ", epaddr_len), - [SDP_HDR_CONNECTION_IP6] = SDP_HDR("c=", "IN IP6 ", epaddr_len), + [SDP_HDR_OWNER_IP4] = SDP_HDR("o=", "IN IP4 ", sdp_addr_len), + [SDP_HDR_CONNECTION_IP4] = SDP_HDR("c=", "IN IP4 ", sdp_addr_len), + [SDP_HDR_OWNER_IP6] = SDP_HDR("o=", "IN IP6 ", sdp_addr_len), + [SDP_HDR_CONNECTION_IP6] = SDP_HDR("c=", "IN IP6 ", sdp_addr_len), [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), }; @@ -775,8 +828,8 @@ static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr, if (ret <= 0) return ret; - if (!parse_addr(ct, dptr + *matchoff, NULL, addr, - dptr + *matchoff + *matchlen)) + if (!sdp_parse_addr(ct, dptr + *matchoff, NULL, addr, + dptr + *matchoff + *matchlen)) return -1; return 1; } -- cgit v1.2.3 From 68e035c950dbceaf660144bf74054dfdfb6aad15 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 14 Aug 2012 12:47:37 +0200 Subject: netfilter: ctnetlink: fix missing locking while changing conntrack from nfqueue Since 9cb017665 netfilter: add glue code to integrate nfnetlink_queue and ctnetlink, we can modify the conntrack entry via nfnl_queue. However, the change of the conntrack entry via nfnetlink_queue requires appropriate locking to avoid concurrent updates. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_netlink.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 14f67a2cbcb5..da4fc37a8578 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1896,10 +1896,15 @@ static int ctnetlink_nfqueue_parse(const struct nlattr *attr, struct nf_conn *ct) { struct nlattr *cda[CTA_MAX+1]; + int ret; nla_parse_nested(cda, CTA_MAX, attr, ct_nla_policy); - return ctnetlink_nfqueue_parse_ct((const struct nlattr **)cda, ct); + spin_lock_bh(&nf_conntrack_lock); + ret = ctnetlink_nfqueue_parse_ct((const struct nlattr **)cda, ct); + spin_unlock_bh(&nf_conntrack_lock); + + return ret; } static struct nfq_ct_hook ctnetlink_nfqueue_hook = { -- cgit v1.2.3 From 2614f86490122bf51eb7c12ec73927f1900f4e7d Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 16 Aug 2012 02:25:24 +0200 Subject: netfilter: nf_ct_expect: fix possible access to uninitialized timer In __nf_ct_expect_check, the function refresh_timer returns 1 if a matching expectation is found and its timer is successfully refreshed. This results in nf_ct_expect_related returning 0. Note that at this point: - the passed expectation is not inserted in the expectation table and its timer was not initialized, since we have refreshed one matching/existing expectation. - nf_ct_expect_alloc uses kmem_cache_alloc, so the expectation timer is in some undefined state just after the allocation, until it is appropriately initialized. This can be a problem for the SIP helper during the expectation addition: ... if (nf_ct_expect_related(rtp_exp) == 0) { if (nf_ct_expect_related(rtcp_exp) != 0) nf_ct_unexpect_related(rtp_exp); ... Note that nf_ct_expect_related(rtp_exp) may return 0 for the timer refresh case that is detailed above. Then, if nf_ct_unexpect_related(rtcp_exp) returns != 0, nf_ct_unexpect_related(rtp_exp) is called, which does: spin_lock_bh(&nf_conntrack_lock); if (del_timer(&exp->timeout)) { nf_ct_unlink_expect(exp); nf_ct_expect_put(exp); } spin_unlock_bh(&nf_conntrack_lock); Note that del_timer always returns false if the timer has been initialized. However, the timer was not initialized since setup_timer was not called, therefore, the expectation timer remains in some undefined state. If I'm not missing anything, this may lead to the removal an unexistent expectation. To fix this, the optimization that allows refreshing an expectation is removed. Now nf_conntrack_expect_related looks more consistent to me since it always add the expectation in case that it returns success. Thanks to Patrick McHardy for participating in the discussion of this patch. I think this may be the source of the problem described by: http://marc.info/?l=netfilter-devel&m=134073514719421&w=2 Reported-by: Rafal Fitt Acked-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_expect.c | 29 ++++++----------------------- 1 file changed, 6 insertions(+), 23 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c index 45cf602a76bc..527651a53a45 100644 --- a/net/netfilter/nf_conntrack_expect.c +++ b/net/netfilter/nf_conntrack_expect.c @@ -361,23 +361,6 @@ static void evict_oldest_expect(struct nf_conn *master, } } -static inline int refresh_timer(struct nf_conntrack_expect *i) -{ - struct nf_conn_help *master_help = nfct_help(i->master); - const struct nf_conntrack_expect_policy *p; - - if (!del_timer(&i->timeout)) - return 0; - - p = &rcu_dereference_protected( - master_help->helper, - lockdep_is_held(&nf_conntrack_lock) - )->expect_policy[i->class]; - i->timeout.expires = jiffies + p->timeout * HZ; - add_timer(&i->timeout); - return 1; -} - static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect) { const struct nf_conntrack_expect_policy *p; @@ -386,7 +369,7 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect) struct nf_conn_help *master_help = nfct_help(master); struct nf_conntrack_helper *helper; struct net *net = nf_ct_exp_net(expect); - struct hlist_node *n; + struct hlist_node *n, *next; unsigned int h; int ret = 1; @@ -395,12 +378,12 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect) goto out; } h = nf_ct_expect_dst_hash(&expect->tuple); - hlist_for_each_entry(i, n, &net->ct.expect_hash[h], hnode) { + hlist_for_each_entry_safe(i, n, next, &net->ct.expect_hash[h], hnode) { if (expect_matches(i, expect)) { - /* Refresh timer: if it's dying, ignore.. */ - if (refresh_timer(i)) { - ret = 0; - goto out; + if (del_timer(&i->timeout)) { + nf_ct_unlink_expect(i); + nf_ct_expect_put(i); + break; } } else if (expect_clash(i, expect)) { ret = -EBUSY; -- cgit v1.2.3