diff options
Diffstat (limited to 'net/ipv4')
-rw-r--r-- | net/ipv4/netfilter/nf_nat_sip.c | 121 |
1 files changed, 84 insertions, 37 deletions
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c index f73ab4883b7..4429069d9b4 100644 --- a/net/ipv4/netfilter/nf_nat_sip.c +++ b/net/ipv4/netfilter/nf_nat_sip.c @@ -316,45 +316,77 @@ static int mangle_content_len(struct sk_buff *skb, buffer, buflen); } -static unsigned mangle_sdp_packet(struct sk_buff *skb, - const char **dptr, unsigned int *datalen, +static unsigned mangle_sdp_packet(struct sk_buff *skb, const char **dptr, + unsigned int dataoff, unsigned int *datalen, enum sdp_header_types type, + enum sdp_header_types term, char *buffer, int buflen) { enum ip_conntrack_info ctinfo; struct nf_conn *ct = nf_ct_get(skb, &ctinfo); unsigned int matchlen, matchoff; - if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen, type, SDP_HDR_UNSPEC, + if (ct_sip_get_sdp_header(ct, *dptr, dataoff, *datalen, type, term, &matchoff, &matchlen) <= 0) return 0; return mangle_packet(skb, dptr, datalen, matchoff, matchlen, buffer, buflen); } -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, unsigned int *datalen) +static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr, + unsigned int dataoff, + unsigned int *datalen, + enum sdp_header_types type, + enum sdp_header_types term, + const union nf_inet_addr *addr) { char buffer[sizeof("nnn.nnn.nnn.nnn")]; - unsigned int bufflen; + unsigned int buflen; - /* Mangle owner and contact info. */ - bufflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip)); - if (!mangle_sdp_packet(skb, dptr, datalen, SDP_HDR_OWNER_IP4, - buffer, bufflen)) + buflen = sprintf(buffer, NIPQUAD_FMT, NIPQUAD(addr->ip)); + if (!mangle_sdp_packet(skb, dptr, dataoff, datalen, type, term, + buffer, buflen)) return 0; - if (!mangle_sdp_packet(skb, dptr, datalen, SDP_HDR_CONNECTION_IP4, - buffer, bufflen)) + return mangle_content_len(skb, dptr, datalen); +} + +static unsigned int ip_nat_sdp_port(struct sk_buff *skb, + const char **dptr, + unsigned int *datalen, + unsigned int matchoff, + unsigned int matchlen, + u_int16_t port) +{ + char buffer[sizeof("nnnnn")]; + unsigned int buflen; + + buflen = sprintf(buffer, "%u", port); + if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen, + buffer, buflen)) return 0; - /* Mangle media port. */ - bufflen = sprintf(buffer, "%u", port); - if (!mangle_sdp_packet(skb, dptr, datalen, SDP_HDR_MEDIA, - buffer, bufflen)) + return mangle_content_len(skb, dptr, datalen); +} + +static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr, + unsigned int dataoff, + unsigned int *datalen, + const union nf_inet_addr *addr) +{ + char buffer[sizeof("nnn.nnn.nnn.nnn")]; + unsigned int buflen; + + /* Mangle session description owner and contact addresses */ + buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(addr->ip)); + if (!mangle_sdp_packet(skb, dptr, dataoff, datalen, + SDP_HDR_OWNER_IP4, SDP_HDR_MEDIA, + buffer, buflen)) + return 0; + + if (!mangle_sdp_packet(skb, dptr, dataoff, datalen, + SDP_HDR_CONNECTION_IP4, SDP_HDR_MEDIA, + buffer, buflen)) return 0; return mangle_content_len(skb, dptr, datalen); @@ -362,32 +394,35 @@ static unsigned int mangle_sdp(struct sk_buff *skb, /* So, this packet has hit the connection tracking matching code. Mangle it, and change the expectation to match the new version. */ -static unsigned int ip_nat_sdp(struct sk_buff *skb, - const char **dptr, unsigned int *datalen, - struct nf_conntrack_expect *rtp_exp, - struct nf_conntrack_expect *rtcp_exp) +static unsigned int ip_nat_sdp_media(struct sk_buff *skb, + const char **dptr, + unsigned int *datalen, + struct nf_conntrack_expect *rtp_exp, + struct nf_conntrack_expect *rtcp_exp, + unsigned int mediaoff, + unsigned int medialen, + union nf_inet_addr *rtp_addr) { enum ip_conntrack_info ctinfo; struct nf_conn *ct = nf_ct_get(skb, &ctinfo); enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - __be32 newip; u_int16_t port; /* Connection will come from reply */ if (ct->tuplehash[dir].tuple.src.u3.ip == ct->tuplehash[!dir].tuple.dst.u3.ip) - newip = rtp_exp->tuple.dst.u3.ip; + rtp_addr->ip = rtp_exp->tuple.dst.u3.ip; else - newip = ct->tuplehash[!dir].tuple.dst.u3.ip; + rtp_addr->ip = ct->tuplehash[!dir].tuple.dst.u3.ip; rtp_exp->saved_ip = rtp_exp->tuple.dst.u3.ip; - rtp_exp->tuple.dst.u3.ip = newip; + rtp_exp->tuple.dst.u3.ip = rtp_addr->ip; rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port; rtp_exp->dir = !dir; rtp_exp->expectfn = ip_nat_sip_expected; rtcp_exp->saved_ip = rtcp_exp->tuple.dst.u3.ip; - rtcp_exp->tuple.dst.u3.ip = newip; + rtcp_exp->tuple.dst.u3.ip = rtp_addr->ip; rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port; rtcp_exp->dir = !dir; rtcp_exp->expectfn = ip_nat_sip_expected; @@ -405,21 +440,29 @@ static unsigned int ip_nat_sdp(struct sk_buff *skb, } if (port == 0) - return NF_DROP; + goto err1; + + /* Update media port. */ + if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port && + !ip_nat_sdp_port(skb, dptr, datalen, mediaoff, medialen, port)) + goto err2; - if (!mangle_sdp(skb, ctinfo, ct, newip, port, dptr, datalen)) { - nf_ct_unexpect_related(rtp_exp); - nf_ct_unexpect_related(rtcp_exp); - return NF_DROP; - } return NF_ACCEPT; + +err2: + nf_ct_unexpect_related(rtp_exp); + nf_ct_unexpect_related(rtcp_exp); +err1: + return NF_DROP; } static void __exit nf_nat_sip_fini(void) { rcu_assign_pointer(nf_nat_sip_hook, NULL); rcu_assign_pointer(nf_nat_sip_expect_hook, NULL); - rcu_assign_pointer(nf_nat_sdp_hook, NULL); + rcu_assign_pointer(nf_nat_sdp_addr_hook, NULL); + rcu_assign_pointer(nf_nat_sdp_session_hook, NULL); + rcu_assign_pointer(nf_nat_sdp_media_hook, NULL); synchronize_rcu(); } @@ -427,10 +470,14 @@ static int __init nf_nat_sip_init(void) { BUG_ON(nf_nat_sip_hook != NULL); BUG_ON(nf_nat_sip_expect_hook != NULL); - BUG_ON(nf_nat_sdp_hook != NULL); + BUG_ON(nf_nat_sdp_addr_hook != NULL); + BUG_ON(nf_nat_sdp_session_hook != NULL); + BUG_ON(nf_nat_sdp_media_hook != NULL); rcu_assign_pointer(nf_nat_sip_hook, ip_nat_sip); rcu_assign_pointer(nf_nat_sip_expect_hook, ip_nat_sip_expect); - rcu_assign_pointer(nf_nat_sdp_hook, ip_nat_sdp); + rcu_assign_pointer(nf_nat_sdp_addr_hook, ip_nat_sdp_addr); + rcu_assign_pointer(nf_nat_sdp_session_hook, ip_nat_sdp_session); + rcu_assign_pointer(nf_nat_sdp_media_hook, ip_nat_sdp_media); return 0; } |