]> asedeno.scripts.mit.edu Git - linux.git/commitdiff
netfilter: REJECT: separate reusable code
authorEric Leblond <eric@regit.org>
Sun, 29 Dec 2013 11:28:13 +0000 (12:28 +0100)
committerPablo Neira Ayuso <pablo@netfilter.org>
Mon, 30 Dec 2013 14:04:41 +0000 (15:04 +0100)
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 <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
include/net/netfilter/ipv4/nf_reject.h [new file with mode: 0644]
include/net/netfilter/ipv6/nf_reject.h [new file with mode: 0644]
net/ipv4/netfilter/ipt_REJECT.c
net/ipv6/netfilter/ip6t_REJECT.c

diff --git a/include/net/netfilter/ipv4/nf_reject.h b/include/net/netfilter/ipv4/nf_reject.h
new file mode 100644 (file)
index 0000000..931fbf8
--- /dev/null
@@ -0,0 +1,128 @@
+#ifndef _IPV4_NF_REJECT_H
+#define _IPV4_NF_REJECT_H
+
+#include <net/ip.h>
+#include <net/tcp.h>
+#include <net/route.h>
+#include <net/dst.h>
+
+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 (file)
index 0000000..710d17e
--- /dev/null
@@ -0,0 +1,171 @@
+#ifndef _IPV6_NF_REJECT_H
+#define _IPV6_NF_REJECT_H
+
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_checksum.h>
+#include <linux/netfilter_ipv6.h>
+
+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 */
index b969131ad1c198c6983b07fb1903abd2498f1374..5b6e0df4ccffcbd712b15757a9557b3cefbbabbd 100644 (file)
 #include <linux/udp.h>
 #include <linux/icmp.h>
 #include <net/icmp.h>
-#include <net/ip.h>
-#include <net/tcp.h>
-#include <net/route.h>
-#include <net/dst.h>
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
 #include <linux/netfilter_ipv4/ipt_REJECT.h>
 #include <linux/netfilter_bridge.h>
 #endif
 
+#include <net/netfilter/ipv4/nf_reject.h>
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
 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;
index da00a2ecde559431993f2e08ca29bc06a226155c..544b0a9da1b59db2fc59cbaf11a1eccd1de8dd3f 100644 (file)
 #include <linux/skbuff.h>
 #include <linux/icmpv6.h>
 #include <linux/netdevice.h>
-#include <net/ipv6.h>
-#include <net/tcp.h>
 #include <net/icmp.h>
-#include <net/ip6_checksum.h>
-#include <net/ip6_fib.h>
-#include <net/ip6_route.h>
 #include <net/flow.h>
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_ipv6/ip6_tables.h>
 #include <linux/netfilter_ipv6/ip6t_REJECT.h>
 
+#include <net/netfilter/ipv6/nf_reject.h>
+
 MODULE_AUTHOR("Yasuyuki KOZAKAI <yasuyuki.kozakai@toshiba.co.jp>");
 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);