3 files changed, 60 insertions, 51 deletions

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 8e5ce1ca7bfc..9d0dbfb26300 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -24,11 +24,13 @@ enum sip_header_pos {
 extern unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
                                        enum ip_conntrack_info ctinfo,
                                        struct nf_conn *ct,
-                                       const char **dptr);
+                                       const char **dptr,
+                                       unsigned int *datalen);
 extern unsigned int (*nf_nat_sdp_hook)(struct sk_buff *skb,
                                        enum ip_conntrack_info ctinfo,
                                        struct nf_conntrack_expect *exp,
-                                       const char *dptr);
+                                       const char **dptr,
+                                       unsigned int *datalen);
 
 extern int ct_sip_get_info(const struct nf_conn *ct, const char *dptr,
                            size_t dlen, unsigned int *matchoff,
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index 84d8b4982cdf..e77122e65283 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -60,15 +60,35 @@ static void addr_map_init(const struct nf_conn *ct, struct addr_map *map)
         }
 }
 
+static unsigned int mangle_packet(struct sk_buff *skb,
+                                  const char **dptr, unsigned int *datalen,
+                                  unsigned int matchoff, unsigned int matchlen,
+                                  const char *buffer, unsigned int buflen)
+{
+        enum ip_conntrack_info ctinfo;
+        struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+        if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, matchoff, matchlen,
+                                      buffer, buflen))
+                return 0;
+
+        /* Reload data pointer and adjust datalen value */
+        *dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
+        *datalen += buflen - matchlen;
+        return 1;
+}
+
 static int map_sip_addr(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
-                        struct nf_conn *ct, const char **dptr, size_t dlen,
+                        struct nf_conn *ct,
+                        const char **dptr, unsigned int *datalen,
                         enum sip_header_pos pos, struct addr_map *map)
 {
         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
         unsigned int matchlen, matchoff, addrlen;
         char *addr;
 
-        if (ct_sip_get_info(ct, *dptr, dlen, &matchoff, &matchlen, pos) <= 0)
+        if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff, &matchlen,
+                            pos) <= 0)
                 return 1;
 
         if ((matchlen == map->addr[dir].srciplen ||
@@ -84,26 +104,19 @@ static int map_sip_addr(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
         } else
                 return 1;
 
-        if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
-                                      matchoff, matchlen, addr, addrlen))
-                return 0;
-        *dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
-        return 1;
-
+        return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+                             addr, addrlen);
 }
 
 static unsigned int ip_nat_sip(struct sk_buff *skb,
                                enum ip_conntrack_info ctinfo,
                                struct nf_conn *ct,
-                               const char **dptr)
+                               const char **dptr, unsigned int *datalen)
 {
         enum sip_header_pos pos;
         struct addr_map map;
-        int dataoff, datalen;
 
-        dataoff = ip_hdrlen(skb) + sizeof(struct udphdr);
-        datalen = skb->len - dataoff;
-        if (datalen < sizeof("SIP/2.0") - 1)
+        if (*datalen < sizeof("SIP/2.0") - 1)
                 return NF_ACCEPT;
 
         addr_map_init(ct, &map);
@@ -115,7 +128,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
                  * The "userinfo" and "@" components of the SIP URI MUST NOT
                  * be present.
                  */
-                if (datalen >= sizeof("REGISTER") - 1 &&
+                if (*datalen >= sizeof("REGISTER") - 1 &&
                     strncmp(*dptr, "REGISTER", sizeof("REGISTER") - 1) == 0)
                         pos = POS_REG_REQ_URI;
                 else
@@ -136,51 +149,45 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 static unsigned int mangle_sip_packet(struct sk_buff *skb,
                                       enum ip_conntrack_info ctinfo,
                                       struct nf_conn *ct,
-                                      const char **dptr, size_t dlen,
+                                      const char **dptr, unsigned int *datalen,
                                       char *buffer, int bufflen,
                                       enum sip_header_pos pos)
 {
         unsigned int matchlen, matchoff;
 
-        if (ct_sip_get_info(ct, *dptr, dlen, &matchoff, &matchlen, pos) <= 0)
-                return 0;
-
-        if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
-                                      matchoff, matchlen, buffer, bufflen))
+        if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff, &matchlen,
+                            pos) <= 0)
                 return 0;
 
-        /* We need to reload this. Thanks Patrick. */
-        *dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
-        return 1;
+        return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+                             buffer, bufflen);
 }
 
 static int mangle_content_len(struct sk_buff *skb,
                               enum ip_conntrack_info ctinfo,
                               struct nf_conn *ct,
-                              const char *dptr)
+                              const char **dptr, unsigned int *datalen)
 {
-        unsigned int dataoff, matchoff, matchlen;
+        unsigned int matchoff, matchlen;
         char buffer[sizeof("65536")];
         int bufflen;
 
-        dataoff = ip_hdrlen(skb) + sizeof(struct udphdr);
-
         /* Get actual SDP length */
-        if (ct_sip_get_info(ct, dptr, skb->len - dataoff, &matchoff,
+        if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff,
                             &matchlen, POS_SDP_HEADER) > 0) {
 
                 /* since ct_sip_get_info() give us a pointer passing 'v='
                    we need to add 2 bytes in this count. */
-                int c_len = skb->len - dataoff - matchoff + 2;
+                int c_len = *datalen - matchoff + 2;
 
                 /* Now, update SDP length */
-                if (ct_sip_get_info(ct, dptr, skb->len - dataoff, &matchoff,
+                if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff,
                                     &matchlen, POS_CONTENT) > 0) {
 
                         bufflen = sprintf(buffer, "%u", c_len);
-                        return nf_nat_mangle_udp_packet(skb, ct, ctinfo,
-                                                        matchoff, matchlen,
-                                                        buffer, bufflen);
+                        return mangle_packet(skb, dptr, datalen,
+                                             matchoff, matchlen,
+                                             buffer, bufflen);
                 }
         }
         return 0;
@@ -190,30 +197,28 @@ static unsigned int mangle_sdp(struct sk_buff *skb,
                                enum ip_conntrack_info ctinfo,
                                struct nf_conn *ct,
                                __be32 newip, u_int16_t port,
-                               const char *dptr)
+                               const char **dptr, unsigned int *datalen)
 {
         char buffer[sizeof("nnn.nnn.nnn.nnn")];
-        unsigned int dataoff, bufflen;
-
-        dataoff = ip_hdrlen(skb) + sizeof(struct udphdr);
+        unsigned int bufflen;
 
         /* Mangle owner and contact info. */
         bufflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip));
-        if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff,
+        if (!mangle_sip_packet(skb, ctinfo, ct, dptr, datalen,
                                buffer, bufflen, POS_OWNER_IP4))
                 return 0;
 
-        if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff,
+        if (!mangle_sip_packet(skb, ctinfo, ct, dptr, datalen,
                                buffer, bufflen, POS_CONNECTION_IP4))
                 return 0;
 
         /* Mangle media port. */
         bufflen = sprintf(buffer, "%u", port);
-        if (!mangle_sip_packet(skb, ctinfo, ct, &dptr, skb->len - dataoff,
+        if (!mangle_sip_packet(skb, ctinfo, ct, dptr, datalen,
                                buffer, bufflen, POS_MEDIA))
                 return 0;
 
-        return mangle_content_len(skb, ctinfo, ct, dptr);
+        return mangle_content_len(skb, ctinfo, ct, dptr, datalen);
 }
 
 static void ip_nat_sdp_expect(struct nf_conn *ct,
@@ -242,7 +247,7 @@ static void ip_nat_sdp_expect(struct nf_conn *ct,
 static unsigned int ip_nat_sdp(struct sk_buff *skb,
                                enum ip_conntrack_info ctinfo,
                                struct nf_conntrack_expect *exp,
-                               const char *dptr)
+                               const char **dptr, unsigned int *datalen)
 {
         struct nf_conn *ct = exp->master;
         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
@@ -275,7 +280,7 @@ static unsigned int ip_nat_sdp(struct sk_buff *skb,
         if (port == 0)
                 return NF_DROP;
 
-        if (!mangle_sdp(skb, ctinfo, ct, newip, port, dptr)) {
+        if (!mangle_sdp(skb, ctinfo, ct, newip, port, dptr, datalen)) {
                 nf_ct_unexpect_related(exp);
                 return NF_DROP;
         }
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 016e1c1aafe4..fa0d5599ff24 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -39,13 +39,15 @@ MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session");
 unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
                                 enum ip_conntrack_info ctinfo,
                                 struct nf_conn *ct,
-                                const char **dptr) __read_mostly;
+                                const char **dptr,
+                                unsigned int *datalen) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sip_hook);
 
 unsigned int (*nf_nat_sdp_hook)(struct sk_buff *skb,
                                 enum ip_conntrack_info ctinfo,
                                 struct nf_conntrack_expect *exp,
-                                const char *dptr) __read_mostly;
+                                const char **dptr,
+                                unsigned int *datalen) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sdp_hook);
 
 static int digits_len(const struct nf_conn *, const char *, const char *, int *);
@@ -369,7 +371,7 @@ static int set_expected_rtp(struct sk_buff *skb,
                             enum ip_conntrack_info ctinfo,
                             union nf_inet_addr *addr,
                             __be16 port,
-                            const char *dptr)
+                            const char **dptr, unsigned int *datalen)
 {
         struct nf_conntrack_expect *exp;
         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
@@ -386,7 +388,7 @@ static int set_expected_rtp(struct sk_buff *skb,
 
         nf_nat_sdp = rcu_dereference(nf_nat_sdp_hook);
         if (nf_nat_sdp && ct->status & IPS_NAT_MASK)
-                ret = nf_nat_sdp(skb, ctinfo, exp, dptr);
+                ret = nf_nat_sdp(skb, ctinfo, exp, dptr, datalen);
         else {
                 if (nf_ct_expect_related(exp) != 0)
                         ret = NF_DROP;
@@ -429,7 +431,7 @@ static int sip_help(struct sk_buff *skb,
 
         nf_nat_sip = rcu_dereference(nf_nat_sip_hook);
         if (nf_nat_sip && ct->status & IPS_NAT_MASK) {
-                if (!nf_nat_sip(skb, ctinfo, ct, &dptr)) {
+                if (!nf_nat_sip(skb, ctinfo, ct, &dptr, &datalen)) {
                         ret = NF_DROP;
                         goto out;
                 }
@@ -466,7 +468,7 @@ static int sip_help(struct sk_buff *skb,
                                 goto out;
                         }
                         ret = set_expected_rtp(skb, ct, ctinfo, &addr,
-                                               htons(port), dptr);
+                                               htons(port), &dptr, &datalen);
                 }
         }
 out: