18 files changed, 872 insertions, 534 deletions

diff --git a/include/net/netfilter/ipv4/nf_reject.h b/include/net/netfilter/ipv4/nf_reject.h
new file mode 100644
index 000000000000..931fbf812171
--- /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 000000000000..710d17ed70b4
--- /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");