vserver 1.9.3

[linux-2.6.git] / net / ipv4 / netfilter / ip_conntrack_proto_udp.c

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_udp.c b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
index a63c32d..5bc28a2 100644 (file)
--- a/net/ipv4/netfilter/ip_conntrack_proto_udp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_udp.c
@@ -12,6 +12,10 @@
 #include <linux/netfilter.h>
 #include <linux/in.h>
 #include <linux/udp.h>
+#include <linux/seq_file.h>
+#include <net/checksum.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
 #include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
 
 unsigned long ip_ct_udp_timeout = 30*HZ;
@@ -21,14 +25,15 @@ static int udp_pkt_to_tuple(const struct sk_buff *skb,
                             unsigned int dataoff,
                             struct ip_conntrack_tuple *tuple)
 {
-       struct udphdr hdr;
+       struct udphdr _hdr, *hp;
 
        /* Actually only need first 8 bytes. */
-       if (skb_copy_bits(skb, dataoff, &hdr, 8) != 0)
+       hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
+       if (hp == NULL)
                return 0;
 
-       tuple->src.u.udp.port = hdr.source;
-       tuple->dst.u.udp.port = hdr.dest;
+       tuple->src.u.udp.port = hp->source;
+       tuple->dst.u.udp.port = hp->dest;
 
        return 1;
 }
@@ -42,17 +47,17 @@ static int udp_invert_tuple(struct ip_conntrack_tuple *tuple,
 }
 
 /* Print out the per-protocol part of the tuple. */
-static unsigned int udp_print_tuple(char *buffer,
-                                   const struct ip_conntrack_tuple *tuple)
+static int udp_print_tuple(struct seq_file *s,
+                          const struct ip_conntrack_tuple *tuple)
 {
-       return sprintf(buffer, "sport=%hu dport=%hu ",
-                      ntohs(tuple->src.u.udp.port),
-                      ntohs(tuple->dst.u.udp.port));
+       return seq_printf(s, "sport=%hu dport=%hu ",
+                         ntohs(tuple->src.u.udp.port),
+                         ntohs(tuple->dst.u.udp.port));
 }
 
 /* Print out the private part of the conntrack. */
-static unsigned int udp_print_conntrack(char *buffer,
-                                       const struct ip_conntrack *conntrack)
+static int udp_print_conntrack(struct seq_file *s,
+                              const struct ip_conntrack *conntrack)
 {
        return 0;
 }
@@ -60,16 +65,17 @@ static unsigned int udp_print_conntrack(char *buffer,
 /* Returns verdict for packet, and may modify conntracktype */
 static int udp_packet(struct ip_conntrack *conntrack,
                      const struct sk_buff *skb,
-                     enum ip_conntrack_info conntrackinfo)
+                     enum ip_conntrack_info ctinfo)
 {
        /* If we've seen traffic both ways, this is some kind of UDP
           stream.  Extend timeout. */
        if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
-               ip_ct_refresh(conntrack, ip_ct_udp_timeout_stream);
+               ip_ct_refresh_acct(conntrack, ctinfo, skb, 
+                                  ip_ct_udp_timeout_stream);
                /* Also, more likely to be important, and not a probe */
                set_bit(IPS_ASSURED_BIT, &conntrack->status);
        } else
-               ip_ct_refresh(conntrack, ip_ct_udp_timeout);
+               ip_ct_refresh_acct(conntrack, ctinfo, skb, ip_ct_udp_timeout);
 
        return NF_ACCEPT;
 }
@@ -80,7 +86,61 @@ static int udp_new(struct ip_conntrack *conntrack, const struct sk_buff *skb)
        return 1;
 }
 
-struct ip_conntrack_protocol ip_conntrack_protocol_udp
-= { { NULL, NULL }, IPPROTO_UDP, "udp",
-    udp_pkt_to_tuple, udp_invert_tuple, udp_print_tuple, udp_print_conntrack,
-    udp_packet, udp_new, NULL, NULL, NULL };
+static int udp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
+                    unsigned int hooknum)
+{
+       struct iphdr *iph = skb->nh.iph;
+       unsigned int udplen = skb->len - iph->ihl * 4;
+       struct udphdr _hdr, *hdr;
+
+       /* Header is too small? */
+       hdr = skb_header_pointer(skb, iph->ihl*4, sizeof(_hdr), &_hdr);
+       if (hdr == NULL) {
+               if (LOG_INVALID(IPPROTO_UDP))
+                       nf_log_packet(PF_INET, 0, skb, NULL, NULL, 
+                                 "ip_ct_udp: short packet ");
+               return -NF_ACCEPT;
+       }
+       
+       /* Truncated/malformed packets */
+       if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
+               if (LOG_INVALID(IPPROTO_UDP))
+                       nf_log_packet(PF_INET, 0, skb, NULL, NULL, 
+                                 "ip_ct_udp: truncated/malformed packet ");
+               return -NF_ACCEPT;
+       }
+       
+       /* Packet with no checksum */
+       if (!hdr->check)
+               return NF_ACCEPT;
+
+       /* Checksum invalid? Ignore.
+        * We skip checking packets on the outgoing path
+        * because the semantic of CHECKSUM_HW is different there 
+        * and moreover root might send raw packets.
+        * FIXME: Source route IP option packets --RR */
+       if (hooknum == NF_IP_PRE_ROUTING
+           && csum_tcpudp_magic(iph->saddr, iph->daddr, udplen, IPPROTO_UDP,
+                                skb->ip_summed == CHECKSUM_HW ? skb->csum
+                                : skb_checksum(skb, iph->ihl*4, udplen, 0))) {
+               if (LOG_INVALID(IPPROTO_UDP))
+                       nf_log_packet(PF_INET, 0, skb, NULL, NULL, 
+                                 "ip_ct_udp: bad UDP checksum ");
+               return -NF_ACCEPT;
+       }
+       
+       return NF_ACCEPT;
+}
+
+struct ip_conntrack_protocol ip_conntrack_protocol_udp =
+{
+       .proto                  = IPPROTO_UDP,
+       .name                   = "udp",
+       .pkt_to_tuple           = udp_pkt_to_tuple,
+       .invert_tuple           = udp_invert_tuple,
+       .print_tuple            = udp_print_tuple,
+       .print_conntrack        = udp_print_conntrack,
+       .packet                 = udp_packet,
+       .new                    = udp_new,
+       .error                  = udp_error,
+};