[NETFILTER]: nf_nat_sip: get rid of text based header translation

Use the URI parsing helper to get the numerical addresses and get rid of the
text based header translation.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 62 deletions

diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index c13e43862361..5b4a5cd23f39 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -26,39 +26,6 @@ MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>");
 MODULE_DESCRIPTION("SIP NAT helper");
 MODULE_ALIAS("ip_nat_sip");
 
-struct addr_map {
-        struct {
-                char            src[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
-                char            dst[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
-                unsigned int    srclen, srciplen;
-                unsigned int    dstlen, dstiplen;
-        } addr[IP_CT_DIR_MAX];
-};
-
-static void addr_map_init(const struct nf_conn *ct, struct addr_map *map)
-{
-        const struct nf_conntrack_tuple *t;
-        enum ip_conntrack_dir dir;
-        unsigned int n;
-
-        for (dir = 0; dir < IP_CT_DIR_MAX; dir++) {
-                t = &ct->tuplehash[dir].tuple;
-
-                n = sprintf(map->addr[dir].src, "%u.%u.%u.%u",
-                            NIPQUAD(t->src.u3.ip));
-                map->addr[dir].srciplen = n;
-                n += sprintf(map->addr[dir].src + n, ":%u",
-                             ntohs(t->src.u.udp.port));
-                map->addr[dir].srclen = n;
-
-                n = sprintf(map->addr[dir].dst, "%u.%u.%u.%u",
-                            NIPQUAD(t->dst.u3.ip));
-                map->addr[dir].dstiplen = n;
-                n += sprintf(map->addr[dir].dst + n, ":%u",
-                             ntohs(t->dst.u.udp.port));
-                map->addr[dir].dstlen = n;
-        }
-}
 
 static unsigned int mangle_packet(struct sk_buff *skb,
                                   const char **dptr, unsigned int *datalen,
@@ -81,43 +48,51 @@ static unsigned int mangle_packet(struct sk_buff *skb,
 static int map_addr(struct sk_buff *skb,
                     const char **dptr, unsigned int *datalen,
                     unsigned int matchoff, unsigned int matchlen,
-                    struct addr_map *map)
+                    union nf_inet_addr *addr, __be16 port)
 {
         enum ip_conntrack_info ctinfo;
-        struct nf_conn *ct __maybe_unused = nf_ct_get(skb, &ctinfo);
+        struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
-        unsigned int addrlen;
-        char *addr;
-
-        if ((matchlen == map->addr[dir].srciplen ||
-             matchlen == map->addr[dir].srclen) &&
-            strncmp(*dptr + matchoff, map->addr[dir].src, matchlen) == 0) {
-                addr    = map->addr[!dir].dst;
-                addrlen = map->addr[!dir].dstlen;
-        } else if ((matchlen == map->addr[dir].dstiplen ||
-                    matchlen == map->addr[dir].dstlen) &&
-                   strncmp(*dptr + matchoff, map->addr[dir].dst, matchlen) == 0) {
-                addr    = map->addr[!dir].src;
-                addrlen = map->addr[!dir].srclen;
+        char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
+        unsigned int buflen;
+        __be32 newaddr;
+        __be16 newport;
+
+        if (ct->tuplehash[dir].tuple.src.u3.ip == addr->ip &&
+            ct->tuplehash[dir].tuple.src.u.udp.port == port) {
+                newaddr = ct->tuplehash[!dir].tuple.dst.u3.ip;
+                newport = ct->tuplehash[!dir].tuple.dst.u.udp.port;
+        } else if (ct->tuplehash[dir].tuple.dst.u3.ip == addr->ip &&
+                   ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
+                newaddr = ct->tuplehash[!dir].tuple.src.u3.ip;
+                newport = ct->tuplehash[!dir].tuple.src.u.udp.port;
         } else
                 return 1;
 
+        if (newaddr == addr->ip && newport == port)
+                return 1;
+
+        buflen = sprintf(buffer, "%u.%u.%u.%u:%u",
+                         NIPQUAD(newaddr), ntohs(newport));
+
         return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
-                             addr, addrlen);
+                             buffer, buflen);
 }
 
 static int map_sip_addr(struct sk_buff *skb,
                         const char **dptr, unsigned int *datalen,
-                        enum sip_header_types type, struct addr_map *map)
+                        enum sip_header_types type)
 {
         enum ip_conntrack_info ctinfo;
         struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
         unsigned int matchlen, matchoff;
+        union nf_inet_addr addr;
+        __be16 port;
 
-        if (ct_sip_get_header(ct, *dptr, 0, *datalen, type,
-                              &matchoff, &matchlen) <= 0)
+        if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, type, NULL,
+                                    &matchoff, &matchlen, &addr, &port) <= 0)
                 return 1;
-        return map_addr(skb, dptr, datalen, matchoff, matchlen, map);
+        return map_addr(skb, dptr, datalen, matchoff, matchlen, &addr, port);
 }
 
 static unsigned int ip_nat_sip(struct sk_buff *skb,
@@ -125,26 +100,27 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 {
         enum ip_conntrack_info ctinfo;
         struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
-        struct addr_map map;
         unsigned int matchoff, matchlen;
+        union nf_inet_addr addr;
+        __be16 port;
 
         if (*datalen < strlen("SIP/2.0"))
                 return NF_ACCEPT;
 
-        addr_map_init(ct, &map);
-
         /* Basic rules: requests and responses. */
         if (strnicmp(*dptr, "SIP/2.0", strlen("SIP/2.0")) != 0) {
                 if (ct_sip_parse_request(ct, *dptr, *datalen,
-                                         &matchoff, &matchlen) > 0 &&
-                    !map_addr(skb, dptr, datalen, matchoff, matchlen, &map))
+                                         &matchoff, &matchlen,
+                                         &addr, &port) > 0 &&
+                    !map_addr(skb, dptr, datalen, matchoff, matchlen,
+                              &addr, port))
                         return NF_DROP;
         }
 
-        if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM, &map) ||
-            !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO, &map) ||
-            !map_sip_addr(skb, dptr, datalen, SIP_HDR_VIA, &map) ||
-            !map_sip_addr(skb, dptr, datalen, SIP_HDR_CONTACT, &map))
+        if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM) ||
+            !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO) ||
+            !map_sip_addr(skb, dptr, datalen, SIP_HDR_VIA) ||
+            !map_sip_addr(skb, dptr, datalen, SIP_HDR_CONTACT))
                 return NF_DROP;
         return NF_ACCEPT;
 }