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,
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,
{
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;
}
*/
int ct_sip_parse_request(const struct nf_conn *ct,
const char *dptr, unsigned int datalen,
- unsigned int *matchoff, unsigned int *matchlen)
+ unsigned int *matchoff, unsigned int *matchlen,
+ union nf_inet_addr *addr, __be16 *port)
{
- const char *start = dptr, *limit = dptr + datalen;
+ const char *start = dptr, *limit = dptr + datalen, *end;
unsigned int mlen;
+ unsigned int p;
int shift = 0;
/* Skip method and following whitespace */
if (strnicmp(dptr, "sip:", strlen("sip:")) == 0)
break;
}
- *matchlen = skp_epaddr_len(ct, dptr, limit, &shift);
- if (!*matchlen)
+ if (!skp_epaddr_len(ct, dptr, limit, &shift))
return 0;
- *matchoff = dptr - start + shift;
+ dptr += shift;
+
+ if (!parse_addr(ct, dptr, &end, addr, limit))
+ return -1;
+ if (end < limit && *end == ':') {
+ end++;
+ p = simple_strtoul(end, (char **)&end, 10);
+ if (p < 1024 || p > 65535)
+ return -1;
+ *port = htons(p);
+ } else
+ *port = htons(SIP_PORT);
+
+ if (end == dptr)
+ return 0;
+ *matchoff = dptr - start;
+ *matchlen = end - dptr;
return 1;
}
EXPORT_SYMBOL_GPL(ct_sip_parse_request);