[NETFILTER]: nf_nat: add helpers for common NAT protocol operations

[linux-2.6-omap-h63xx.git] / net / ipv4 / netfilter / nf_nat_proto_udp.c

diff --git a/net/ipv4/netfilter/nf_nat_proto_udp.c b/net/ipv4/netfilter/nf_nat_proto_udp.c
index a0af4fd95584f0c67bc834833aad79ddb168e6d7..a182f5ac317740d3c2e236e25b1456c9c9fad2e3 100644 (file)
--- a/net/ipv4/netfilter/nf_nat_proto_udp.c
+++ b/net/ipv4/netfilter/nf_nat_proto_udp.c
@@ -8,7 +8,6 @@
 
 #include <linux/types.h>
 #include <linux/init.h>
-#include <linux/random.h>
 #include <linux/ip.h>
 #include <linux/udp.h>
 
@@ -18,22 +17,7 @@
 #include <net/netfilter/nf_nat_rule.h>
 #include <net/netfilter/nf_nat_protocol.h>
 
-static int
-udp_in_range(const struct nf_conntrack_tuple *tuple,
-            enum nf_nat_manip_type maniptype,
-            const union nf_conntrack_man_proto *min,
-            const union nf_conntrack_man_proto *max)
-{
-       __be16 port;
-
-       if (maniptype == IP_NAT_MANIP_SRC)
-               port = tuple->src.u.udp.port;
-       else
-               port = tuple->dst.u.udp.port;
-
-       return ntohs(port) >= ntohs(min->udp.port) &&
-              ntohs(port) <= ntohs(max->udp.port);
-}
+static u_int16_t udp_port_rover;
 
 static int
 udp_unique_tuple(struct nf_conntrack_tuple *tuple,
@@ -41,67 +25,27 @@ udp_unique_tuple(struct nf_conntrack_tuple *tuple,
                 enum nf_nat_manip_type maniptype,
                 const struct nf_conn *ct)
 {
-       static u_int16_t port;
-       __be16 *portptr;
-       unsigned int range_size, min, i;
-
-       if (maniptype == IP_NAT_MANIP_SRC)
-               portptr = &tuple->src.u.udp.port;
-       else
-               portptr = &tuple->dst.u.udp.port;
-
-       /* If no range specified... */
-       if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
-               /* If it's dst rewrite, can't change port */
-               if (maniptype == IP_NAT_MANIP_DST)
-                       return 0;
-
-               if (ntohs(*portptr) < 1024) {
-                       /* Loose convention: >> 512 is credential passing */
-                       if (ntohs(*portptr)<512) {
-                               min = 1;
-                               range_size = 511 - min + 1;
-                       } else {
-                               min = 600;
-                               range_size = 1023 - min + 1;
-                       }
-               } else {
-                       min = 1024;
-                       range_size = 65535 - 1024 + 1;
-               }
-       } else {
-               min = ntohs(range->min.udp.port);
-               range_size = ntohs(range->max.udp.port) - min + 1;
-       }
-
-       if (range->flags & IP_NAT_RANGE_PROTO_RANDOM)
-               port = net_random();
-
-       for (i = 0; i < range_size; i++, port++) {
-               *portptr = htons(min + port % range_size);
-               if (!nf_nat_used_tuple(tuple, ct))
-                       return 1;
-       }
-       return 0;
+       return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
+                                        &udp_port_rover);
 }
 
 static int
-udp_manip_pkt(struct sk_buff **pskb,
+udp_manip_pkt(struct sk_buff *skb,
              unsigned int iphdroff,
              const struct nf_conntrack_tuple *tuple,
              enum nf_nat_manip_type maniptype)
 {
-       struct iphdr *iph = (struct iphdr *)((*pskb)->data + iphdroff);
+       const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
        struct udphdr *hdr;
        unsigned int hdroff = iphdroff + iph->ihl*4;
        __be32 oldip, newip;
        __be16 *portptr, newport;
 
-       if (!skb_make_writable(pskb, hdroff + sizeof(*hdr)))
+       if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
                return 0;
 
-       iph = (struct iphdr *)((*pskb)->data + iphdroff);
-       hdr = (struct udphdr *)((*pskb)->data + hdroff);
+       iph = (struct iphdr *)(skb->data + iphdroff);
+       hdr = (struct udphdr *)(skb->data + hdroff);
 
        if (maniptype == IP_NAT_MANIP_SRC) {
                /* Get rid of src ip and src pt */
@@ -116,10 +60,10 @@ udp_manip_pkt(struct sk_buff **pskb,
                newport = tuple->dst.u.udp.port;
                portptr = &hdr->dest;
        }
-       if (hdr->check || (*pskb)->ip_summed == CHECKSUM_PARTIAL) {
-               nf_proto_csum_replace4(&hdr->check, *pskb, oldip, newip, 1);
-               nf_proto_csum_replace2(&hdr->check, *pskb, *portptr, newport,
-                                      0);
+       if (hdr->check || skb->ip_summed == CHECKSUM_PARTIAL) {
+               inet_proto_csum_replace4(&hdr->check, skb, oldip, newip, 1);
+               inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport,
+                                        0);
                if (!hdr->check)
                        hdr->check = CSUM_MANGLED_0;
        }
@@ -127,12 +71,12 @@ udp_manip_pkt(struct sk_buff **pskb,
        return 1;
 }
 
-struct nf_nat_protocol nf_nat_protocol_udp = {
+const struct nf_nat_protocol nf_nat_protocol_udp = {
        .name                   = "UDP",
        .protonum               = IPPROTO_UDP,
        .me                     = THIS_MODULE,
        .manip_pkt              = udp_manip_pkt,
-       .in_range               = udp_in_range,
+       .in_range               = nf_nat_proto_in_range,
        .unique_tuple           = udp_unique_tuple,
 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
        .range_to_nlattr        = nf_nat_port_range_to_nlattr,