From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 15/31] netfilter: conntrack: remove the l4proto->new() function Date: Tue, 9 Oct 2018 01:01:09 +0200 Message-ID: <20181008230125.2330-16-pablo@netfilter.org> References: <20181008230125.2330-1-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: Received: from mail.us.es ([193.147.175.20]:56250 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726569AbeJIGPr (ORCPT ); Tue, 9 Oct 2018 02:15:47 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 5A76B53AA41 for ; Tue, 9 Oct 2018 01:01:43 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 2ECB2DA856 for ; Tue, 9 Oct 2018 01:01:43 +0200 (CEST) In-Reply-To: <20181008230125.2330-1-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Florian Westphal ->new() gets invoked after ->error() and before ->packet() if a conntrack lookup has found no result for the tuple. We can fold it into ->packet() -- the packet() implementations can check if the conntrack is confirmed (new) or not (already in hash). If its unconfirmed, the conntrack isn't in the hash yet so current skb created a new conntrack entry. Only relevant side effect -- if packet() doesn't return NF_ACCEPT but -NF_ACCEPT (or drop), while the conntrack was just created, then the newly allocated conntrack is freed right away, rather than not created in the first place. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_l4proto.h | 5 - net/netfilter/nf_conntrack_core.c | 6 -- net/netfilter/nf_conntrack_proto_dccp.c | 17 ++- net/netfilter/nf_conntrack_proto_generic.c | 20 ++-- net/netfilter/nf_conntrack_proto_gre.c | 33 +++--- net/netfilter/nf_conntrack_proto_icmp.c | 28 ++--- net/netfilter/nf_conntrack_proto_icmpv6.c | 37 +++---- net/netfilter/nf_conntrack_proto_sctp.c | 144 ++++++++++++------------- net/netfilter/nf_conntrack_proto_tcp.c | 156 +++++++++++++-------------- net/netfilter/nf_conntrack_proto_udp.c | 11 -- 10 files changed, 194 insertions(+), 263 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h index a857a0adfb31..016958e67fcc 100644 --- a/include/net/netfilter/nf_conntrack_l4proto.h +++ b/include/net/netfilter/nf_conntrack_l4proto.h @@ -48,11 +48,6 @@ struct nf_conntrack_l4proto { enum ip_conntrack_info ctinfo, const struct nf_hook_state *state); - /* Called when a new connection for this protocol found; - * returns TRUE if it's OK. If so, packet() called next. */ - bool (*new)(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff); - /* Called when a conntrack entry is destroyed */ void (*destroy)(struct nf_conn *ct); diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 8e275f4cdcdd..dccc96e94d7c 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1370,12 +1370,6 @@ init_conntrack(struct net *net, struct nf_conn *tmpl, timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL; - if (!l4proto->new(ct, skb, dataoff)) { - nf_conntrack_free(ct); - pr_debug("can't track with proto module\n"); - return NULL; - } - if (timeout_ext) nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout), GFP_ATOMIC); diff --git a/net/netfilter/nf_conntrack_proto_dccp.c b/net/netfilter/nf_conntrack_proto_dccp.c index 8595c79742a2..e7b5449ea883 100644 --- a/net/netfilter/nf_conntrack_proto_dccp.c +++ b/net/netfilter/nf_conntrack_proto_dccp.c @@ -389,18 +389,15 @@ static inline struct nf_dccp_net *dccp_pernet(struct net *net) return &net->ct.nf_ct_proto.dccp; } -static bool dccp_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) +static noinline bool +dccp_new(struct nf_conn *ct, const struct sk_buff *skb, + const struct dccp_hdr *dh) { struct net *net = nf_ct_net(ct); struct nf_dccp_net *dn; - struct dccp_hdr _dh, *dh; const char *msg; u_int8_t state; - dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); - BUG_ON(dh == NULL); - state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE]; switch (state) { default: @@ -449,8 +446,12 @@ static int dccp_packet(struct nf_conn *ct, const struct sk_buff *skb, unsigned int *timeouts; dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); - BUG_ON(dh == NULL); + if (!dh) + return NF_DROP; + type = dh->dccph_type; + if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh)) + return -NF_ACCEPT; if (type == DCCP_PKT_RESET && !test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { @@ -850,7 +851,6 @@ static struct nf_proto_net *dccp_get_net_proto(struct net *net) const struct nf_conntrack_l4proto nf_conntrack_l4proto_dccp4 = { .l3proto = AF_INET, .l4proto = IPPROTO_DCCP, - .new = dccp_new, .packet = dccp_packet, .error = dccp_error, .can_early_drop = dccp_can_early_drop, @@ -883,7 +883,6 @@ EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_dccp4); const struct nf_conntrack_l4proto nf_conntrack_l4proto_dccp6 = { .l3proto = AF_INET6, .l4proto = IPPROTO_DCCP, - .new = dccp_new, .packet = dccp_packet, .error = dccp_error, .can_early_drop = dccp_can_early_drop, diff --git a/net/netfilter/nf_conntrack_proto_generic.c b/net/netfilter/nf_conntrack_proto_generic.c index 9940161cfef1..deeb05c50f02 100644 --- a/net/netfilter/nf_conntrack_proto_generic.c +++ b/net/netfilter/nf_conntrack_proto_generic.c @@ -51,6 +51,12 @@ static int generic_packet(struct nf_conn *ct, { const unsigned int *timeout = nf_ct_timeout_lookup(ct); + if (!nf_generic_should_process(nf_ct_protonum(ct))) { + pr_warn_once("conntrack: generic helper won't handle protocol %d. Please consider loading the specific helper module.\n", + nf_ct_protonum(ct)); + return -NF_ACCEPT; + } + if (!timeout) timeout = &generic_pernet(nf_ct_net(ct))->timeout; @@ -58,19 +64,6 @@ static int generic_packet(struct nf_conn *ct, return NF_ACCEPT; } -/* Called when a new connection for this protocol found. */ -static bool generic_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) -{ - bool ret; - - ret = nf_generic_should_process(nf_ct_protonum(ct)); - if (!ret) - pr_warn_once("conntrack: generic helper won't handle protocol %d. Please consider loading the specific helper module.\n", - nf_ct_protonum(ct)); - return ret; -} - #ifdef CONFIG_NF_CONNTRACK_TIMEOUT #include @@ -164,7 +157,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic = .l4proto = 255, .pkt_to_tuple = generic_pkt_to_tuple, .packet = generic_packet, - .new = generic_new, #ifdef CONFIG_NF_CONNTRACK_TIMEOUT .ctnl_timeout = { .nlattr_to_obj = generic_timeout_nlattr_to_obj, diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c index 85313a191456..a44bbee271cb 100644 --- a/net/netfilter/nf_conntrack_proto_gre.c +++ b/net/netfilter/nf_conntrack_proto_gre.c @@ -238,6 +238,18 @@ static int gre_packet(struct nf_conn *ct, enum ip_conntrack_info ctinfo, const struct nf_hook_state *state) { + if (!nf_ct_is_confirmed(ct)) { + unsigned int *timeouts = nf_ct_timeout_lookup(ct); + + if (!timeouts) + timeouts = gre_get_timeouts(nf_ct_net(ct)); + + /* initialize to sane value. Ideally a conntrack helper + * (e.g. in case of pptp) is increasing them */ + ct->proto.gre.stream_timeout = timeouts[GRE_CT_REPLIED]; + ct->proto.gre.timeout = timeouts[GRE_CT_UNREPLIED]; + } + /* If we've seen traffic both ways, this is a GRE connection. * Extend timeout. */ if (ct->status & IPS_SEEN_REPLY) { @@ -253,26 +265,6 @@ static int gre_packet(struct nf_conn *ct, return NF_ACCEPT; } -/* Called when a new connection for this protocol found. */ -static bool gre_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) -{ - unsigned int *timeouts = nf_ct_timeout_lookup(ct); - - if (!timeouts) - timeouts = gre_get_timeouts(nf_ct_net(ct)); - - pr_debug(": "); - nf_ct_dump_tuple(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); - - /* initialize to sane value. Ideally a conntrack helper - * (e.g. in case of pptp) is increasing them */ - ct->proto.gre.stream_timeout = timeouts[GRE_CT_REPLIED]; - ct->proto.gre.timeout = timeouts[GRE_CT_UNREPLIED]; - - return true; -} - /* Called when a conntrack entry has already been removed from the hashes * and is about to be deleted from memory */ static void gre_destroy(struct nf_conn *ct) @@ -359,7 +351,6 @@ static const struct nf_conntrack_l4proto nf_conntrack_l4proto_gre4 = { .print_conntrack = gre_print_conntrack, #endif .packet = gre_packet, - .new = gre_new, .destroy = gre_destroy, .me = THIS_MODULE, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) diff --git a/net/netfilter/nf_conntrack_proto_icmp.c b/net/netfilter/nf_conntrack_proto_icmp.c index c3a304b53245..19ef0c41602b 100644 --- a/net/netfilter/nf_conntrack_proto_icmp.c +++ b/net/netfilter/nf_conntrack_proto_icmp.c @@ -72,11 +72,6 @@ static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple, return true; } -static unsigned int *icmp_get_timeouts(struct net *net) -{ - return &icmp_pernet(net)->timeout; -} - /* Returns verdict for packet, or -1 for invalid. */ static int icmp_packet(struct nf_conn *ct, const struct sk_buff *skb, @@ -88,19 +83,6 @@ static int icmp_packet(struct nf_conn *ct, successful reply to avoid excessive conntrackd traffic and also to handle correctly ICMP echo reply duplicates. */ unsigned int *timeout = nf_ct_timeout_lookup(ct); - - if (!timeout) - timeout = icmp_get_timeouts(nf_ct_net(ct)); - - nf_ct_refresh_acct(ct, ctinfo, skb, *timeout); - - return NF_ACCEPT; -} - -/* Called when a new connection for this protocol found. */ -static bool icmp_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) -{ static const u_int8_t valid_new[] = { [ICMP_ECHO] = 1, [ICMP_TIMESTAMP] = 1, @@ -114,9 +96,14 @@ static bool icmp_new(struct nf_conn *ct, const struct sk_buff *skb, pr_debug("icmp: can't create new conn with type %u\n", ct->tuplehash[0].tuple.dst.u.icmp.type); nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple); - return false; + return -NF_ACCEPT; } - return true; + + if (!timeout) + timeout = &icmp_pernet(nf_ct_net(ct))->timeout; + + nf_ct_refresh_acct(ct, ctinfo, skb, *timeout); + return NF_ACCEPT; } /* Returns conntrack if it dealt with ICMP, and filled in skb fields */ @@ -368,7 +355,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp = .pkt_to_tuple = icmp_pkt_to_tuple, .invert_tuple = icmp_invert_tuple, .packet = icmp_packet, - .new = icmp_new, .error = icmp_error, .destroy = NULL, .me = NULL, diff --git a/net/netfilter/nf_conntrack_proto_icmpv6.c b/net/netfilter/nf_conntrack_proto_icmpv6.c index bb5c98b0af89..bb94363818e6 100644 --- a/net/netfilter/nf_conntrack_proto_icmpv6.c +++ b/net/netfilter/nf_conntrack_proto_icmpv6.c @@ -98,6 +98,22 @@ static int icmpv6_packet(struct nf_conn *ct, const struct nf_hook_state *state) { unsigned int *timeout = nf_ct_timeout_lookup(ct); + static const u8 valid_new[] = { + [ICMPV6_ECHO_REQUEST - 128] = 1, + [ICMPV6_NI_QUERY - 128] = 1 + }; + + if (!nf_ct_is_confirmed(ct)) { + int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128; + + if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) { + /* Can't create a new ICMPv6 `conn' with this. */ + pr_debug("icmpv6: can't create new conn with type %u\n", + type + 128); + nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple); + return -NF_ACCEPT; + } + } if (!timeout) timeout = icmpv6_get_timeouts(nf_ct_net(ct)); @@ -110,26 +126,6 @@ static int icmpv6_packet(struct nf_conn *ct, return NF_ACCEPT; } -/* Called when a new connection for this protocol found. */ -static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) -{ - static const u_int8_t valid_new[] = { - [ICMPV6_ECHO_REQUEST - 128] = 1, - [ICMPV6_NI_QUERY - 128] = 1 - }; - int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128; - - if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) { - /* Can't create a new ICMPv6 `conn' with this. */ - pr_debug("icmpv6: can't create new conn with type %u\n", - type + 128); - nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple); - return false; - } - return true; -} - static int icmpv6_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb, @@ -370,7 +366,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 = .pkt_to_tuple = icmpv6_pkt_to_tuple, .invert_tuple = icmpv6_invert_tuple, .packet = icmpv6_packet, - .new = icmpv6_new, .error = icmpv6_error, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) .tuple_to_nlattr = icmpv6_tuple_to_nlattr, diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index 34b80cea4a56..78c115152a78 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -273,6 +273,63 @@ static int sctp_new_state(enum ip_conntrack_dir dir, return sctp_conntracks[dir][i][cur_state]; } +/* Don't need lock here: this conntrack not in circulation yet */ +static noinline bool +sctp_new(struct nf_conn *ct, const struct sk_buff *skb, + const struct sctphdr *sh, unsigned int dataoff) +{ + enum sctp_conntrack new_state; + const struct sctp_chunkhdr *sch; + struct sctp_chunkhdr _sch; + u32 offset, count; + + memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp)); + new_state = SCTP_CONNTRACK_MAX; + for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) { + new_state = sctp_new_state(IP_CT_DIR_ORIGINAL, + SCTP_CONNTRACK_NONE, sch->type); + + /* Invalid: delete conntrack */ + if (new_state == SCTP_CONNTRACK_NONE || + new_state == SCTP_CONNTRACK_MAX) { + pr_debug("nf_conntrack_sctp: invalid new deleting.\n"); + return false; + } + + /* Copy the vtag into the state info */ + if (sch->type == SCTP_CID_INIT) { + struct sctp_inithdr _inithdr, *ih; + /* Sec 8.5.1 (A) */ + if (sh->vtag) + return false; + + ih = skb_header_pointer(skb, offset + sizeof(_sch), + sizeof(_inithdr), &_inithdr); + if (!ih) + return false; + + pr_debug("Setting vtag %x for new conn\n", + ih->init_tag); + + ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag; + } 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; + } else { + /* If it is a shutdown ack OOTB packet, we expect a return + shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */ + pr_debug("Setting vtag %x for new conn OOTB\n", + sh->vtag); + ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag; + } + + ct->proto.sctp.state = new_state; + } + + return true; +} + /* Returns verdict for packet, or -NF_ACCEPT for invalid. */ static int sctp_packet(struct nf_conn *ct, const struct sk_buff *skb, @@ -297,6 +354,17 @@ static int sctp_packet(struct nf_conn *ct, if (do_basic_checks(ct, skb, dataoff, map) != 0) goto out; + if (!nf_ct_is_confirmed(ct)) { + /* If an OOTB packet has any of these chunks discard (Sec 8.4) */ + if (test_bit(SCTP_CID_ABORT, map) || + test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) || + test_bit(SCTP_CID_COOKIE_ACK, map)) + return -NF_ACCEPT; + + if (!sctp_new(ct, skb, sh, dataoff)) + return -NF_ACCEPT; + } + /* Check the verification tag (Sec 8.5) */ if (!test_bit(SCTP_CID_INIT, map) && !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) && @@ -398,80 +466,6 @@ static int sctp_packet(struct nf_conn *ct, return -NF_ACCEPT; } -/* Called when a new connection for this protocol found. */ -static bool sctp_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) -{ - enum sctp_conntrack new_state; - const struct sctphdr *sh; - struct sctphdr _sctph; - const struct sctp_chunkhdr *sch; - struct sctp_chunkhdr _sch; - u_int32_t offset, count; - unsigned long map[256 / sizeof(unsigned long)] = { 0 }; - - sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph); - if (sh == NULL) - return false; - - if (do_basic_checks(ct, skb, dataoff, map) != 0) - return false; - - /* If an OOTB packet has any of these chunks discard (Sec 8.4) */ - if (test_bit(SCTP_CID_ABORT, map) || - test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) || - test_bit(SCTP_CID_COOKIE_ACK, map)) - return false; - - memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp)); - new_state = SCTP_CONNTRACK_MAX; - for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { - /* Don't need lock here: this conntrack not in circulation yet */ - new_state = sctp_new_state(IP_CT_DIR_ORIGINAL, - SCTP_CONNTRACK_NONE, sch->type); - - /* Invalid: delete conntrack */ - if (new_state == SCTP_CONNTRACK_NONE || - new_state == SCTP_CONNTRACK_MAX) { - pr_debug("nf_conntrack_sctp: invalid new deleting.\n"); - return false; - } - - /* Copy the vtag into the state info */ - if (sch->type == SCTP_CID_INIT) { - struct sctp_inithdr _inithdr, *ih; - /* Sec 8.5.1 (A) */ - if (sh->vtag) - return false; - - ih = skb_header_pointer(skb, offset + sizeof(_sch), - sizeof(_inithdr), &_inithdr); - if (!ih) - return false; - - pr_debug("Setting vtag %x for new conn\n", - ih->init_tag); - - ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag; - } 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; - } - /* If it is a shutdown ack OOTB packet, we expect a return - shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */ - else { - pr_debug("Setting vtag %x for new conn OOTB\n", - sh->vtag); - ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag; - } - - ct->proto.sctp.state = new_state; - } - - return true; -} - static int sctp_error(struct nf_conn *tpl, struct sk_buff *skb, unsigned int dataoff, const struct nf_hook_state *state) @@ -769,7 +763,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 = { .print_conntrack = sctp_print_conntrack, #endif .packet = sctp_packet, - .new = sctp_new, .error = sctp_error, .can_early_drop = sctp_can_early_drop, .me = THIS_MODULE, @@ -803,7 +796,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 = { .print_conntrack = sctp_print_conntrack, #endif .packet = sctp_packet, - .new = sctp_new, .error = sctp_error, .can_early_drop = sctp_can_early_drop, .me = THIS_MODULE, diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c index 5128f0a79ed4..6d278cdff145 100644 --- a/net/netfilter/nf_conntrack_proto_tcp.c +++ b/net/netfilter/nf_conntrack_proto_tcp.c @@ -770,6 +770,78 @@ static int tcp_error(struct nf_conn *tmpl, return NF_ACCEPT; } +static noinline bool tcp_new(struct nf_conn *ct, const struct sk_buff *skb, + unsigned int dataoff, + const struct tcphdr *th) +{ + enum tcp_conntrack new_state; + struct net *net = nf_ct_net(ct); + const struct nf_tcp_net *tn = tcp_pernet(net); + const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[0]; + const struct ip_ct_tcp_state *receiver = &ct->proto.tcp.seen[1]; + + /* Don't need lock here: this conntrack not in circulation yet */ + new_state = tcp_conntracks[0][get_conntrack_index(th)][TCP_CONNTRACK_NONE]; + + /* Invalid: delete conntrack */ + if (new_state >= TCP_CONNTRACK_MAX) { + pr_debug("nf_ct_tcp: invalid new deleting.\n"); + return false; + } + + if (new_state == TCP_CONNTRACK_SYN_SENT) { + memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp)); + /* SYN packet */ + ct->proto.tcp.seen[0].td_end = + segment_seq_plus_len(ntohl(th->seq), skb->len, + dataoff, th); + ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window); + if (ct->proto.tcp.seen[0].td_maxwin == 0) + ct->proto.tcp.seen[0].td_maxwin = 1; + ct->proto.tcp.seen[0].td_maxend = + ct->proto.tcp.seen[0].td_end; + + tcp_options(skb, dataoff, th, &ct->proto.tcp.seen[0]); + } else if (tn->tcp_loose == 0) { + /* Don't try to pick up connections. */ + return false; + } else { + memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp)); + /* + * We are in the middle of a connection, + * its history is lost for us. + * Let's try to use the data from the packet. + */ + ct->proto.tcp.seen[0].td_end = + segment_seq_plus_len(ntohl(th->seq), skb->len, + dataoff, th); + ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window); + if (ct->proto.tcp.seen[0].td_maxwin == 0) + ct->proto.tcp.seen[0].td_maxwin = 1; + ct->proto.tcp.seen[0].td_maxend = + ct->proto.tcp.seen[0].td_end + + ct->proto.tcp.seen[0].td_maxwin; + + /* We assume SACK and liberal window checking to handle + * window scaling */ + ct->proto.tcp.seen[0].flags = + ct->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM | + IP_CT_TCP_FLAG_BE_LIBERAL; + } + + /* tcp_packet will set them */ + ct->proto.tcp.last_index = TCP_NONE_SET; + + pr_debug("%s: sender end=%u maxend=%u maxwin=%u scale=%i " + "receiver end=%u maxend=%u maxwin=%u scale=%i\n", + __func__, + sender->td_end, sender->td_maxend, sender->td_maxwin, + sender->td_scale, + receiver->td_end, receiver->td_maxend, receiver->td_maxwin, + receiver->td_scale); + return true; +} + /* Returns verdict for packet, or -1 for invalid. */ static int tcp_packet(struct nf_conn *ct, const struct sk_buff *skb, @@ -788,7 +860,11 @@ static int tcp_packet(struct nf_conn *ct, unsigned long timeout; th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph); - BUG_ON(th == NULL); + if (th == NULL) + return -NF_ACCEPT; + + if (!nf_ct_is_confirmed(ct) && !tcp_new(ct, skb, dataoff, th)) + return -NF_ACCEPT; spin_lock_bh(&ct->lock); old_state = ct->proto.tcp.state; @@ -1069,82 +1145,6 @@ static int tcp_packet(struct nf_conn *ct, return NF_ACCEPT; } -/* Called when a new connection for this protocol found. */ -static bool tcp_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) -{ - enum tcp_conntrack new_state; - const struct tcphdr *th; - struct tcphdr _tcph; - struct net *net = nf_ct_net(ct); - struct nf_tcp_net *tn = tcp_pernet(net); - const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[0]; - const struct ip_ct_tcp_state *receiver = &ct->proto.tcp.seen[1]; - - th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph); - BUG_ON(th == NULL); - - /* Don't need lock here: this conntrack not in circulation yet */ - new_state = tcp_conntracks[0][get_conntrack_index(th)][TCP_CONNTRACK_NONE]; - - /* Invalid: delete conntrack */ - if (new_state >= TCP_CONNTRACK_MAX) { - pr_debug("nf_ct_tcp: invalid new deleting.\n"); - return false; - } - - if (new_state == TCP_CONNTRACK_SYN_SENT) { - memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp)); - /* SYN packet */ - ct->proto.tcp.seen[0].td_end = - segment_seq_plus_len(ntohl(th->seq), skb->len, - dataoff, th); - ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window); - if (ct->proto.tcp.seen[0].td_maxwin == 0) - ct->proto.tcp.seen[0].td_maxwin = 1; - ct->proto.tcp.seen[0].td_maxend = - ct->proto.tcp.seen[0].td_end; - - tcp_options(skb, dataoff, th, &ct->proto.tcp.seen[0]); - } else if (tn->tcp_loose == 0) { - /* Don't try to pick up connections. */ - return false; - } else { - memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp)); - /* - * We are in the middle of a connection, - * its history is lost for us. - * Let's try to use the data from the packet. - */ - ct->proto.tcp.seen[0].td_end = - segment_seq_plus_len(ntohl(th->seq), skb->len, - dataoff, th); - ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window); - if (ct->proto.tcp.seen[0].td_maxwin == 0) - ct->proto.tcp.seen[0].td_maxwin = 1; - ct->proto.tcp.seen[0].td_maxend = - ct->proto.tcp.seen[0].td_end + - ct->proto.tcp.seen[0].td_maxwin; - - /* We assume SACK and liberal window checking to handle - * window scaling */ - ct->proto.tcp.seen[0].flags = - ct->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM | - IP_CT_TCP_FLAG_BE_LIBERAL; - } - - /* tcp_packet will set them */ - ct->proto.tcp.last_index = TCP_NONE_SET; - - pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i " - "receiver end=%u maxend=%u maxwin=%u scale=%i\n", - sender->td_end, sender->td_maxend, sender->td_maxwin, - sender->td_scale, - receiver->td_end, receiver->td_maxend, receiver->td_maxwin, - receiver->td_scale); - return true; -} - static bool tcp_can_early_drop(const struct nf_conn *ct) { switch (ct->proto.tcp.state) { @@ -1548,7 +1548,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 = .print_conntrack = tcp_print_conntrack, #endif .packet = tcp_packet, - .new = tcp_new, .error = tcp_error, .can_early_drop = tcp_can_early_drop, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) @@ -1583,7 +1582,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 = .print_conntrack = tcp_print_conntrack, #endif .packet = tcp_packet, - .new = tcp_new, .error = tcp_error, .can_early_drop = tcp_can_early_drop, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) diff --git a/net/netfilter/nf_conntrack_proto_udp.c b/net/netfilter/nf_conntrack_proto_udp.c index bf59d32bba98..1119323425e7 100644 --- a/net/netfilter/nf_conntrack_proto_udp.c +++ b/net/netfilter/nf_conntrack_proto_udp.c @@ -70,13 +70,6 @@ static int udp_packet(struct nf_conn *ct, return NF_ACCEPT; } -/* Called when a new connection for this protocol found. */ -static bool udp_new(struct nf_conn *ct, const struct sk_buff *skb, - unsigned int dataoff) -{ - return true; -} - #ifdef CONFIG_NF_CT_PROTO_UDPLITE static void udplite_error_log(const struct sk_buff *skb, const struct nf_hook_state *state, @@ -288,7 +281,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 = .l4proto = IPPROTO_UDP, .allow_clash = true, .packet = udp_packet, - .new = udp_new, .error = udp_error, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, @@ -317,7 +309,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 = .l4proto = IPPROTO_UDPLITE, .allow_clash = true, .packet = udp_packet, - .new = udp_new, .error = udplite_error, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, @@ -346,7 +337,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 = .l4proto = IPPROTO_UDP, .allow_clash = true, .packet = udp_packet, - .new = udp_new, .error = udp_error, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, @@ -375,7 +365,6 @@ const struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 = .l4proto = IPPROTO_UDPLITE, .allow_clash = true, .packet = udp_packet, - .new = udp_new, .error = udplite_error, #if IS_ENABLED(CONFIG_NF_CT_NETLINK) .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, -- 2.11.0