From patchwork Mon Jan 6 13:46:37 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 307320 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44DB52C00D4 for ; Tue, 7 Jan 2014 00:47:39 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751763AbaAFNrb (ORCPT ); Mon, 6 Jan 2014 08:47:31 -0500 Received: from mail.us.es ([193.147.175.20]:59553 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754719AbaAFNrA (ORCPT ); Mon, 6 Jan 2014 08:47:00 -0500 Received: (qmail 9967 invoked from network); 6 Jan 2014 14:46:58 +0100 Received: from unknown (HELO us.es) (192.168.2.13) by us.es with SMTP; 6 Jan 2014 14:46:58 +0100 Received: (qmail 20413 invoked by uid 507); 6 Jan 2014 13:46:58 -0000 X-Qmail-Scanner-Diagnostics: from 127.0.0.1 by antivirus3 (envelope-from , uid 501) with qmail-scanner-2.10 (clamdscan: 0.98/18317. spamassassin: 3.3.2. 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Processed in 2.752271 secs); 06 Jan 2014 13:46:58 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on antivirus3 X-Spam-Level: X-Spam-Status: No, score=-99.8 required=7.5 tests=BAYES_50,RCVD_IN_PBL, RCVD_IN_RP_RNBL, RCVD_IN_SORBS_DUL, RDNS_DYNAMIC, SMTPAUTH_US, USER_IN_WHITELIST autolearn=disabled version=3.3.2 X-Spam-ASN: AS12715 95.20.0.0/16 X-Envelope-From: pablo@netfilter.org Received: from unknown (HELO antivirus3) (127.0.0.1) by us.es with SMTP; 6 Jan 2014 13:46:56 -0000 Received: from 192.168.1.13 (192.168.1.13) by antivirus3 (F-Secure/fsigk_smtp/412/antivirus3); Mon, 06 Jan 2014 14:46:56 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/412/antivirus3) Received: (qmail 24112 invoked from network); 6 Jan 2014 14:46:55 +0100 Received: from 108.60.20.95.dynamic.jazztel.es (HELO localhost.localdomain) (pneira@us.es@95.20.60.108) by mail.us.es with SMTP; 6 Jan 2014 14:46:55 +0100 From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 08/13] netfilter: REJECT: separate reusable code Date: Mon, 6 Jan 2014 14:46:37 +0100 Message-Id: <1389016002-9116-9-git-send-email-pablo@netfilter.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1389016002-9116-1-git-send-email-pablo@netfilter.org> References: <1389016002-9116-1-git-send-email-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Leblond This patch prepares the addition of TCP reset support in the nft_reject module by moving reusable code into a header file. Signed-off-by: Eric Leblond Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/ipv4/nf_reject.h | 128 +++++++++++++++++++++++ include/net/netfilter/ipv6/nf_reject.h | 171 ++++++++++++++++++++++++++++++ net/ipv4/netfilter/ipt_REJECT.c | 140 ++----------------------- net/ipv6/netfilter/ip6t_REJECT.c | 179 ++------------------------------ 4 files changed, 317 insertions(+), 301 deletions(-) create mode 100644 include/net/netfilter/ipv4/nf_reject.h create mode 100644 include/net/netfilter/ipv6/nf_reject.h diff --git a/include/net/netfilter/ipv4/nf_reject.h b/include/net/netfilter/ipv4/nf_reject.h new file mode 100644 index 0000000..931fbf8 --- /dev/null +++ b/include/net/netfilter/ipv4/nf_reject.h @@ -0,0 +1,128 @@ +#ifndef _IPV4_NF_REJECT_H +#define _IPV4_NF_REJECT_H + +#include +#include +#include +#include + +static inline void nf_send_unreach(struct sk_buff *skb_in, int code) +{ + icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0); +} + +/* Send RST reply */ +static void nf_send_reset(struct sk_buff *oldskb, int hook) +{ + struct sk_buff *nskb; + const struct iphdr *oiph; + struct iphdr *niph; + const struct tcphdr *oth; + struct tcphdr _otcph, *tcph; + + /* IP header checks: fragment. */ + if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET)) + return; + + oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb), + sizeof(_otcph), &_otcph); + if (oth == NULL) + return; + + /* No RST for RST. */ + if (oth->rst) + return; + + if (skb_rtable(oldskb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) + return; + + /* Check checksum */ + if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP)) + return; + oiph = ip_hdr(oldskb); + + nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) + + LL_MAX_HEADER, GFP_ATOMIC); + if (!nskb) + return; + + skb_reserve(nskb, LL_MAX_HEADER); + + skb_reset_network_header(nskb); + niph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr)); + niph->version = 4; + niph->ihl = sizeof(struct iphdr) / 4; + niph->tos = 0; + niph->id = 0; + niph->frag_off = htons(IP_DF); + niph->protocol = IPPROTO_TCP; + niph->check = 0; + niph->saddr = oiph->daddr; + niph->daddr = oiph->saddr; + + skb_reset_transport_header(nskb); + tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr)); + memset(tcph, 0, sizeof(*tcph)); + tcph->source = oth->dest; + tcph->dest = oth->source; + tcph->doff = sizeof(struct tcphdr) / 4; + + if (oth->ack) + tcph->seq = oth->ack_seq; + else { + tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin + + oldskb->len - ip_hdrlen(oldskb) - + (oth->doff << 2)); + tcph->ack = 1; + } + + tcph->rst = 1; + tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), niph->saddr, + niph->daddr, 0); + nskb->ip_summed = CHECKSUM_PARTIAL; + nskb->csum_start = (unsigned char *)tcph - nskb->head; + nskb->csum_offset = offsetof(struct tcphdr, check); + + /* ip_route_me_harder expects skb->dst to be set */ + skb_dst_set_noref(nskb, skb_dst(oldskb)); + + nskb->protocol = htons(ETH_P_IP); + if (ip_route_me_harder(nskb, RTN_UNSPEC)) + goto free_nskb; + + niph->ttl = ip4_dst_hoplimit(skb_dst(nskb)); + + /* "Never happens" */ + if (nskb->len > dst_mtu(skb_dst(nskb))) + goto free_nskb; + + nf_ct_attach(nskb, oldskb); + +#ifdef CONFIG_BRIDGE_NETFILTER + /* If we use ip_local_out for bridged traffic, the MAC source on + * the RST will be ours, instead of the destination's. This confuses + * some routers/firewalls, and they drop the packet. So we need to + * build the eth header using the original destination's MAC as the + * source, and send the RST packet directly. + */ + if (oldskb->nf_bridge) { + struct ethhdr *oeth = eth_hdr(oldskb); + nskb->dev = oldskb->nf_bridge->physindev; + niph->tot_len = htons(nskb->len); + ip_send_check(niph); + if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol), + oeth->h_source, oeth->h_dest, nskb->len) < 0) + goto free_nskb; + dev_queue_xmit(nskb); + } else +#endif + ip_local_out(nskb); + + return; + + free_nskb: + kfree_skb(nskb); +} + + +#endif /* _IPV4_NF_REJECT_H */ diff --git a/include/net/netfilter/ipv6/nf_reject.h b/include/net/netfilter/ipv6/nf_reject.h new file mode 100644 index 0000000..710d17e --- /dev/null +++ b/include/net/netfilter/ipv6/nf_reject.h @@ -0,0 +1,171 @@ +#ifndef _IPV6_NF_REJECT_H +#define _IPV6_NF_REJECT_H + +#include +#include +#include +#include +#include + +static inline void +nf_send_unreach6(struct net *net, struct sk_buff *skb_in, unsigned char code, + unsigned int hooknum) +{ + if (hooknum == NF_INET_LOCAL_OUT && skb_in->dev == NULL) + skb_in->dev = net->loopback_dev; + + icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0); +} + +/* Send RST reply */ +static void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook) +{ + struct sk_buff *nskb; + struct tcphdr otcph, *tcph; + unsigned int otcplen, hh_len; + int tcphoff, needs_ack; + const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); + struct ipv6hdr *ip6h; +#define DEFAULT_TOS_VALUE 0x0U + const __u8 tclass = DEFAULT_TOS_VALUE; + struct dst_entry *dst = NULL; + u8 proto; + __be16 frag_off; + struct flowi6 fl6; + + if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) || + (!(ipv6_addr_type(&oip6h->daddr) & IPV6_ADDR_UNICAST))) { + pr_debug("addr is not unicast.\n"); + return; + } + + proto = oip6h->nexthdr; + tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), &proto, &frag_off); + + if ((tcphoff < 0) || (tcphoff > oldskb->len)) { + pr_debug("Cannot get TCP header.\n"); + return; + } + + otcplen = oldskb->len - tcphoff; + + /* IP header checks: fragment, too short. */ + if (proto != IPPROTO_TCP || otcplen < sizeof(struct tcphdr)) { + pr_debug("proto(%d) != IPPROTO_TCP, " + "or too short. otcplen = %d\n", + proto, otcplen); + return; + } + + if (skb_copy_bits(oldskb, tcphoff, &otcph, sizeof(struct tcphdr))) + BUG(); + + /* No RST for RST. */ + if (otcph.rst) { + pr_debug("RST is set\n"); + return; + } + + /* Check checksum. */ + if (nf_ip6_checksum(oldskb, hook, tcphoff, IPPROTO_TCP)) { + pr_debug("TCP checksum is invalid\n"); + return; + } + + memset(&fl6, 0, sizeof(fl6)); + fl6.flowi6_proto = IPPROTO_TCP; + fl6.saddr = oip6h->daddr; + fl6.daddr = oip6h->saddr; + fl6.fl6_sport = otcph.dest; + fl6.fl6_dport = otcph.source; + security_skb_classify_flow(oldskb, flowi6_to_flowi(&fl6)); + dst = ip6_route_output(net, NULL, &fl6); + if (dst == NULL || dst->error) { + dst_release(dst); + return; + } + dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); + if (IS_ERR(dst)) + return; + + hh_len = (dst->dev->hard_header_len + 15)&~15; + nskb = alloc_skb(hh_len + 15 + dst->header_len + sizeof(struct ipv6hdr) + + sizeof(struct tcphdr) + dst->trailer_len, + GFP_ATOMIC); + + if (!nskb) { + net_dbg_ratelimited("cannot alloc skb\n"); + dst_release(dst); + return; + } + + skb_dst_set(nskb, dst); + + skb_reserve(nskb, hh_len + dst->header_len); + + skb_put(nskb, sizeof(struct ipv6hdr)); + skb_reset_network_header(nskb); + ip6h = ipv6_hdr(nskb); + ip6_flow_hdr(ip6h, tclass, 0); + ip6h->hop_limit = ip6_dst_hoplimit(dst); + ip6h->nexthdr = IPPROTO_TCP; + ip6h->saddr = oip6h->daddr; + ip6h->daddr = oip6h->saddr; + + skb_reset_transport_header(nskb); + tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr)); + /* Truncate to length (no data) */ + tcph->doff = sizeof(struct tcphdr)/4; + tcph->source = otcph.dest; + tcph->dest = otcph.source; + + if (otcph.ack) { + needs_ack = 0; + tcph->seq = otcph.ack_seq; + tcph->ack_seq = 0; + } else { + needs_ack = 1; + tcph->ack_seq = htonl(ntohl(otcph.seq) + otcph.syn + otcph.fin + + otcplen - (otcph.doff<<2)); + tcph->seq = 0; + } + + /* Reset flags */ + ((u_int8_t *)tcph)[13] = 0; + tcph->rst = 1; + tcph->ack = needs_ack; + tcph->window = 0; + tcph->urg_ptr = 0; + tcph->check = 0; + + /* Adjust TCP checksum */ + tcph->check = csum_ipv6_magic(&ipv6_hdr(nskb)->saddr, + &ipv6_hdr(nskb)->daddr, + sizeof(struct tcphdr), IPPROTO_TCP, + csum_partial(tcph, + sizeof(struct tcphdr), 0)); + + nf_ct_attach(nskb, oldskb); + +#ifdef CONFIG_BRIDGE_NETFILTER + /* If we use ip6_local_out for bridged traffic, the MAC source on + * the RST will be ours, instead of the destination's. This confuses + * some routers/firewalls, and they drop the packet. So we need to + * build the eth header using the original destination's MAC as the + * source, and send the RST packet directly. + */ + if (oldskb->nf_bridge) { + struct ethhdr *oeth = eth_hdr(oldskb); + nskb->dev = oldskb->nf_bridge->physindev; + nskb->protocol = htons(ETH_P_IPV6); + ip6h->payload_len = htons(sizeof(struct tcphdr)); + if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol), + oeth->h_source, oeth->h_dest, nskb->len) < 0) + return; + dev_queue_xmit(nskb); + } else +#endif + ip6_local_out(nskb); +} + +#endif /* _IPV6_NF_REJECT_H */ diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c index b969131..5b6e0df 100644 --- a/net/ipv4/netfilter/ipt_REJECT.c +++ b/net/ipv4/netfilter/ipt_REJECT.c @@ -17,10 +17,6 @@ #include #include #include -#include -#include -#include -#include #include #include #include @@ -28,128 +24,12 @@ #include #endif +#include + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Netfilter Core Team "); MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv4"); -/* Send RST reply */ -static void send_reset(struct sk_buff *oldskb, int hook) -{ - struct sk_buff *nskb; - const struct iphdr *oiph; - struct iphdr *niph; - const struct tcphdr *oth; - struct tcphdr _otcph, *tcph; - - /* IP header checks: fragment. */ - if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET)) - return; - - oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb), - sizeof(_otcph), &_otcph); - if (oth == NULL) - return; - - /* No RST for RST. */ - if (oth->rst) - return; - - if (skb_rtable(oldskb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) - return; - - /* Check checksum */ - if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP)) - return; - oiph = ip_hdr(oldskb); - - nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) + - LL_MAX_HEADER, GFP_ATOMIC); - if (!nskb) - return; - - skb_reserve(nskb, LL_MAX_HEADER); - - skb_reset_network_header(nskb); - niph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr)); - niph->version = 4; - niph->ihl = sizeof(struct iphdr) / 4; - niph->tos = 0; - niph->id = 0; - niph->frag_off = htons(IP_DF); - niph->protocol = IPPROTO_TCP; - niph->check = 0; - niph->saddr = oiph->daddr; - niph->daddr = oiph->saddr; - - skb_reset_transport_header(nskb); - tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr)); - memset(tcph, 0, sizeof(*tcph)); - tcph->source = oth->dest; - tcph->dest = oth->source; - tcph->doff = sizeof(struct tcphdr) / 4; - - if (oth->ack) - tcph->seq = oth->ack_seq; - else { - tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin + - oldskb->len - ip_hdrlen(oldskb) - - (oth->doff << 2)); - tcph->ack = 1; - } - - tcph->rst = 1; - tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), niph->saddr, - niph->daddr, 0); - nskb->ip_summed = CHECKSUM_PARTIAL; - nskb->csum_start = (unsigned char *)tcph - nskb->head; - nskb->csum_offset = offsetof(struct tcphdr, check); - - /* ip_route_me_harder expects skb->dst to be set */ - skb_dst_set_noref(nskb, skb_dst(oldskb)); - - nskb->protocol = htons(ETH_P_IP); - if (ip_route_me_harder(nskb, RTN_UNSPEC)) - goto free_nskb; - - niph->ttl = ip4_dst_hoplimit(skb_dst(nskb)); - - /* "Never happens" */ - if (nskb->len > dst_mtu(skb_dst(nskb))) - goto free_nskb; - - nf_ct_attach(nskb, oldskb); - -#ifdef CONFIG_BRIDGE_NETFILTER - /* If we use ip_local_out for bridged traffic, the MAC source on - * the RST will be ours, instead of the destination's. This confuses - * some routers/firewalls, and they drop the packet. So we need to - * build the eth header using the original destination's MAC as the - * source, and send the RST packet directly. - */ - if (oldskb->nf_bridge) { - struct ethhdr *oeth = eth_hdr(oldskb); - nskb->dev = oldskb->nf_bridge->physindev; - niph->tot_len = htons(nskb->len); - ip_send_check(niph); - if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol), - oeth->h_source, oeth->h_dest, nskb->len) < 0) - goto free_nskb; - dev_queue_xmit(nskb); - } else -#endif - ip_local_out(nskb); - - return; - - free_nskb: - kfree_skb(nskb); -} - -static inline void send_unreach(struct sk_buff *skb_in, int code) -{ - icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0); -} - static unsigned int reject_tg(struct sk_buff *skb, const struct xt_action_param *par) { @@ -157,28 +37,28 @@ reject_tg(struct sk_buff *skb, const struct xt_action_param *par) switch (reject->with) { case IPT_ICMP_NET_UNREACHABLE: - send_unreach(skb, ICMP_NET_UNREACH); + nf_send_unreach(skb, ICMP_NET_UNREACH); break; case IPT_ICMP_HOST_UNREACHABLE: - send_unreach(skb, ICMP_HOST_UNREACH); + nf_send_unreach(skb, ICMP_HOST_UNREACH); break; case IPT_ICMP_PROT_UNREACHABLE: - send_unreach(skb, ICMP_PROT_UNREACH); + nf_send_unreach(skb, ICMP_PROT_UNREACH); break; case IPT_ICMP_PORT_UNREACHABLE: - send_unreach(skb, ICMP_PORT_UNREACH); + nf_send_unreach(skb, ICMP_PORT_UNREACH); break; case IPT_ICMP_NET_PROHIBITED: - send_unreach(skb, ICMP_NET_ANO); + nf_send_unreach(skb, ICMP_NET_ANO); break; case IPT_ICMP_HOST_PROHIBITED: - send_unreach(skb, ICMP_HOST_ANO); + nf_send_unreach(skb, ICMP_HOST_ANO); break; case IPT_ICMP_ADMIN_PROHIBITED: - send_unreach(skb, ICMP_PKT_FILTERED); + nf_send_unreach(skb, ICMP_PKT_FILTERED); break; case IPT_TCP_RESET: - send_reset(skb, par->hooknum); + nf_send_reset(skb, par->hooknum); case IPT_ICMP_ECHOREPLY: /* Doesn't happen. */ break; diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c index da00a2e..544b0a9 100644 --- a/net/ipv6/netfilter/ip6t_REJECT.c +++ b/net/ipv6/netfilter/ip6t_REJECT.c @@ -23,181 +23,18 @@ #include #include #include -#include -#include #include -#include -#include -#include #include #include #include #include +#include + MODULE_AUTHOR("Yasuyuki KOZAKAI "); MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv6"); MODULE_LICENSE("GPL"); -/* Send RST reply */ -static void send_reset(struct net *net, struct sk_buff *oldskb, int hook) -{ - struct sk_buff *nskb; - struct tcphdr otcph, *tcph; - unsigned int otcplen, hh_len; - int tcphoff, needs_ack; - const struct ipv6hdr *oip6h = ipv6_hdr(oldskb); - struct ipv6hdr *ip6h; -#define DEFAULT_TOS_VALUE 0x0U - const __u8 tclass = DEFAULT_TOS_VALUE; - struct dst_entry *dst = NULL; - u8 proto; - __be16 frag_off; - struct flowi6 fl6; - - if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) || - (!(ipv6_addr_type(&oip6h->daddr) & IPV6_ADDR_UNICAST))) { - pr_debug("addr is not unicast.\n"); - return; - } - - proto = oip6h->nexthdr; - tcphoff = ipv6_skip_exthdr(oldskb, ((u8*)(oip6h+1) - oldskb->data), &proto, &frag_off); - - if ((tcphoff < 0) || (tcphoff > oldskb->len)) { - pr_debug("Cannot get TCP header.\n"); - return; - } - - otcplen = oldskb->len - tcphoff; - - /* IP header checks: fragment, too short. */ - if (proto != IPPROTO_TCP || otcplen < sizeof(struct tcphdr)) { - pr_debug("proto(%d) != IPPROTO_TCP, " - "or too short. otcplen = %d\n", - proto, otcplen); - return; - } - - if (skb_copy_bits(oldskb, tcphoff, &otcph, sizeof(struct tcphdr))) - BUG(); - - /* No RST for RST. */ - if (otcph.rst) { - pr_debug("RST is set\n"); - return; - } - - /* Check checksum. */ - if (nf_ip6_checksum(oldskb, hook, tcphoff, IPPROTO_TCP)) { - pr_debug("TCP checksum is invalid\n"); - return; - } - - memset(&fl6, 0, sizeof(fl6)); - fl6.flowi6_proto = IPPROTO_TCP; - fl6.saddr = oip6h->daddr; - fl6.daddr = oip6h->saddr; - fl6.fl6_sport = otcph.dest; - fl6.fl6_dport = otcph.source; - security_skb_classify_flow(oldskb, flowi6_to_flowi(&fl6)); - dst = ip6_route_output(net, NULL, &fl6); - if (dst == NULL || dst->error) { - dst_release(dst); - return; - } - dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); - if (IS_ERR(dst)) - return; - - hh_len = (dst->dev->hard_header_len + 15)&~15; - nskb = alloc_skb(hh_len + 15 + dst->header_len + sizeof(struct ipv6hdr) - + sizeof(struct tcphdr) + dst->trailer_len, - GFP_ATOMIC); - - if (!nskb) { - net_dbg_ratelimited("cannot alloc skb\n"); - dst_release(dst); - return; - } - - skb_dst_set(nskb, dst); - - skb_reserve(nskb, hh_len + dst->header_len); - - skb_put(nskb, sizeof(struct ipv6hdr)); - skb_reset_network_header(nskb); - ip6h = ipv6_hdr(nskb); - ip6_flow_hdr(ip6h, tclass, 0); - ip6h->hop_limit = ip6_dst_hoplimit(dst); - ip6h->nexthdr = IPPROTO_TCP; - ip6h->saddr = oip6h->daddr; - ip6h->daddr = oip6h->saddr; - - skb_reset_transport_header(nskb); - tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr)); - /* Truncate to length (no data) */ - tcph->doff = sizeof(struct tcphdr)/4; - tcph->source = otcph.dest; - tcph->dest = otcph.source; - - if (otcph.ack) { - needs_ack = 0; - tcph->seq = otcph.ack_seq; - tcph->ack_seq = 0; - } else { - needs_ack = 1; - tcph->ack_seq = htonl(ntohl(otcph.seq) + otcph.syn + otcph.fin - + otcplen - (otcph.doff<<2)); - tcph->seq = 0; - } - - /* Reset flags */ - ((u_int8_t *)tcph)[13] = 0; - tcph->rst = 1; - tcph->ack = needs_ack; - tcph->window = 0; - tcph->urg_ptr = 0; - tcph->check = 0; - - /* Adjust TCP checksum */ - tcph->check = csum_ipv6_magic(&ipv6_hdr(nskb)->saddr, - &ipv6_hdr(nskb)->daddr, - sizeof(struct tcphdr), IPPROTO_TCP, - csum_partial(tcph, - sizeof(struct tcphdr), 0)); - - nf_ct_attach(nskb, oldskb); - -#ifdef CONFIG_BRIDGE_NETFILTER - /* If we use ip6_local_out for bridged traffic, the MAC source on - * the RST will be ours, instead of the destination's. This confuses - * some routers/firewalls, and they drop the packet. So we need to - * build the eth header using the original destination's MAC as the - * source, and send the RST packet directly. - */ - if (oldskb->nf_bridge) { - struct ethhdr *oeth = eth_hdr(oldskb); - nskb->dev = oldskb->nf_bridge->physindev; - nskb->protocol = htons(ETH_P_IPV6); - ip6h->payload_len = htons(sizeof(struct tcphdr)); - if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol), - oeth->h_source, oeth->h_dest, nskb->len) < 0) - return; - dev_queue_xmit(nskb); - } else -#endif - ip6_local_out(nskb); -} - -static inline void -send_unreach(struct net *net, struct sk_buff *skb_in, unsigned char code, - unsigned int hooknum) -{ - if (hooknum == NF_INET_LOCAL_OUT && skb_in->dev == NULL) - skb_in->dev = net->loopback_dev; - - icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0); -} static unsigned int reject_tg6(struct sk_buff *skb, const struct xt_action_param *par) @@ -208,25 +45,25 @@ reject_tg6(struct sk_buff *skb, const struct xt_action_param *par) pr_debug("%s: medium point\n", __func__); switch (reject->with) { case IP6T_ICMP6_NO_ROUTE: - send_unreach(net, skb, ICMPV6_NOROUTE, par->hooknum); + nf_send_unreach6(net, skb, ICMPV6_NOROUTE, par->hooknum); break; case IP6T_ICMP6_ADM_PROHIBITED: - send_unreach(net, skb, ICMPV6_ADM_PROHIBITED, par->hooknum); + nf_send_unreach6(net, skb, ICMPV6_ADM_PROHIBITED, par->hooknum); break; case IP6T_ICMP6_NOT_NEIGHBOUR: - send_unreach(net, skb, ICMPV6_NOT_NEIGHBOUR, par->hooknum); + nf_send_unreach6(net, skb, ICMPV6_NOT_NEIGHBOUR, par->hooknum); break; case IP6T_ICMP6_ADDR_UNREACH: - send_unreach(net, skb, ICMPV6_ADDR_UNREACH, par->hooknum); + nf_send_unreach6(net, skb, ICMPV6_ADDR_UNREACH, par->hooknum); break; case IP6T_ICMP6_PORT_UNREACH: - send_unreach(net, skb, ICMPV6_PORT_UNREACH, par->hooknum); + nf_send_unreach6(net, skb, ICMPV6_PORT_UNREACH, par->hooknum); break; case IP6T_ICMP6_ECHOREPLY: /* Do nothing */ break; case IP6T_TCP_RESET: - send_reset(net, skb, par->hooknum); + nf_send_reset6(net, skb, par->hooknum); break; default: net_info_ratelimited("case %u not handled yet\n", reject->with);