[NETFILTER]: nf_conntrack_sip: move SDP parsing to seperate function

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

diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index f20fa2d..96bedb5 100644 (file)
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -565,19 +565,49 @@ static int set_expected_rtp(struct sk_buff *skb,
        return ret;
 }
 
+static int process_sdp(struct sk_buff *skb,
+                      const char **dptr, unsigned int *datalen)
+{
+       enum ip_conntrack_info ctinfo;
+       struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+       int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+       unsigned int matchoff, matchlen;
+       union nf_inet_addr addr;
+       unsigned int port;
+       enum sdp_header_types type;
+
+       /* Get address and port from SDP packet. */
+       type = family == AF_INET ? SDP_HDR_CONNECTION_IP4 :
+                                  SDP_HDR_CONNECTION_IP6;
+
+       if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen,
+                                 type, SDP_HDR_UNSPEC,
+                                 &matchoff, &matchlen) <= 0)
+               return NF_ACCEPT;
+
+       /* We'll drop only if there are parse problems. */
+       if (!parse_addr(ct, *dptr + matchoff, NULL, &addr, *dptr + *datalen))
+               return NF_DROP;
+
+       if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen,
+                                 SDP_HDR_MEDIA, SDP_HDR_UNSPEC,
+                                 &matchoff, &matchlen) <= 0)
+               return NF_ACCEPT;
+
+       port = simple_strtoul(*dptr + matchoff, NULL, 10);
+       if (port < 1024 || port > 65535)
+               return NF_DROP;
+
+       return set_expected_rtp(skb, dptr, datalen, &addr, htons(port));
+}
+
 static int sip_help(struct sk_buff *skb,
                    unsigned int protoff,
                    struct nf_conn *ct,
                    enum ip_conntrack_info ctinfo)
 {
-       int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
-       union nf_inet_addr addr;
        unsigned int dataoff, datalen;
        const char *dptr;
-       int ret = NF_ACCEPT;
-       unsigned int matchoff, matchlen;
-       u_int16_t port;
-       enum sdp_header_types type;
        typeof(nf_nat_sip_hook) nf_nat_sip;
 
        /* No Data ? */
@@ -591,56 +621,28 @@ static int sip_help(struct sk_buff *skb,
                dptr = skb->data + dataoff;
        else {
                pr_debug("Copy of skbuff not supported yet.\n");
-               goto out;
+               return NF_ACCEPT;
        }
 
        nf_nat_sip = rcu_dereference(nf_nat_sip_hook);
        if (nf_nat_sip && ct->status & IPS_NAT_MASK) {
-               if (!nf_nat_sip(skb, &dptr, &datalen)) {
-                       ret = NF_DROP;
-                       goto out;
-               }
+               if (!nf_nat_sip(skb, &dptr, &datalen))
+                       return NF_DROP;
        }
 
        datalen = skb->len - dataoff;
        if (datalen < strlen("SIP/2.0 200"))
-               goto out;
+               return NF_ACCEPT;
 
        /* RTP info only in some SDP pkts */
        if (strnicmp(dptr, "INVITE", strlen("INVITE")) != 0 &&
            strnicmp(dptr, "UPDATE", strlen("UPDATE")) != 0 &&
            strnicmp(dptr, "SIP/2.0 180", strlen("SIP/2.0 180")) != 0 &&
            strnicmp(dptr, "SIP/2.0 183", strlen("SIP/2.0 183")) != 0 &&
-           strnicmp(dptr, "SIP/2.0 200", strlen("SIP/2.0 200")) != 0) {
-               goto out;
-       }
-       /* Get address and port from SDP packet. */
-       type = family == AF_INET ? SDP_HDR_CONNECTION_IP4 :
-                                  SDP_HDR_CONNECTION_IP6;
-       if (ct_sip_get_sdp_header(ct, dptr, 0, datalen, type, SDP_HDR_UNSPEC,
-                                 &matchoff, &matchlen) > 0) {
+           strnicmp(dptr, "SIP/2.0 200", strlen("SIP/2.0 200")) != 0)
+               return NF_ACCEPT;
 
-               /* We'll drop only if there are parse problems. */
-               if (!parse_addr(ct, dptr + matchoff, NULL, &addr,
-                               dptr + datalen)) {
-                       ret = NF_DROP;
-                       goto out;
-               }
-               if (ct_sip_get_sdp_header(ct, dptr, 0, datalen,
-                                         SDP_HDR_MEDIA, SDP_HDR_UNSPEC,
-                                         &matchoff, &matchlen) > 0) {
-
-                       port = simple_strtoul(dptr + matchoff, NULL, 10);
-                       if (port < 1024) {
-                               ret = NF_DROP;
-                               goto out;
-                       }
-                       ret = set_expected_rtp(skb, &dptr, &datalen,
-                                              &addr, htons(port));
-               }
-       }
-out:
-       return ret;
+       return process_sdp(skb, &dptr, &datalen);
 }
 
 static struct nf_conntrack_helper sip[MAX_PORTS][2] __read_mostly;