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Commit 7d3dd043 authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

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



Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 624f8b7b

net/netfilter/nf_conntrack_sip.c

+43 −41
Original line number Diff line number Diff line
@@ -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) {



		/* 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) {

	    strnicmp(dptr, "SIP/2.0 200", strlen("SIP/2.0 200")) != 0)

		return NF_ACCEPT;



			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;