From: Eric Leblond <eric@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
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 <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
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 <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 */
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 <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>
@@ -28,128 +24,12 @@
#include <linux/netfilter_bridge.h>
#endif
+#include <net/netfilter/ipv4/nf_reject.h>
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@xxxxxxxxxxxxx>");
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 <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@xxxxxxxxxxxxx>");
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);
--
1.7.10.4
--
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