diff options
| -rw-r--r-- | net/netfilter/nf_conntrack_sip.c | 84 |
1 files changed, 43 insertions, 41 deletions
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index f20fa2d94c0a..96bedb52bd4b 100644 --- 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; |