diff options
Diffstat (limited to 'net/ipv4/netfilter/ip_nat_helper_h323.c')
-rw-r--r-- | net/ipv4/netfilter/ip_nat_helper_h323.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ip_nat_helper_h323.c b/net/ipv4/netfilter/ip_nat_helper_h323.c index d45663d..419b878 100644 --- a/net/ipv4/netfilter/ip_nat_helper_h323.c +++ b/net/ipv4/netfilter/ip_nat_helper_h323.c @@ -487,6 +487,80 @@ static int nat_q931(struct sk_buff **pskb, struct ip_conntrack *ct, } /****************************************************************************/ +static void ip_nat_callforwarding_expect(struct ip_conntrack *new, + struct ip_conntrack_expect *this) +{ + struct ip_nat_range range; + + /* This must be a fresh one. */ + BUG_ON(new->status & IPS_NAT_DONE_MASK); + + /* Change src to where master sends to */ + range.flags = IP_NAT_RANGE_MAP_IPS; + range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.ip; + + /* hook doesn't matter, but it has to do source manip */ + ip_nat_setup_info(new, &range, NF_IP_POST_ROUTING); + + /* For DST manip, map port here to where it's expected. */ + range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED); + range.min = range.max = this->saved_proto; + range.min_ip = range.max_ip = this->saved_ip; + + /* hook doesn't matter, but it has to do destination manip */ + ip_nat_setup_info(new, &range, NF_IP_PRE_ROUTING); + + ip_conntrack_q931_expect(new, this); +} + +/****************************************************************************/ +static int nat_callforwarding(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + TransportAddress * addr, u_int16_t port, + struct ip_conntrack_expect *exp) +{ + int dir = CTINFO2DIR(ctinfo); + u_int16_t nated_port; + + /* Set expectations for NAT */ + exp->saved_ip = exp->tuple.dst.ip; + exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip; + exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; + exp->expectfn = ip_nat_callforwarding_expect; + exp->dir = !dir; + + /* Try to get same port: if not, try to change it. */ + for (nated_port = port; nated_port != 0; nated_port++) { + exp->tuple.dst.u.tcp.port = htons(nated_port); + if (ip_conntrack_expect_related(exp) == 0) + break; + } + + if (nated_port == 0) { /* No port available */ + if (net_ratelimit()) + printk("ip_nat_q931: out of TCP ports\n"); + return 0; + } + + /* Modify signal */ + if (!set_h225_addr(pskb, data, dataoff, addr, + ct->tuplehash[!dir].tuple.dst.ip, + nated_port) == 0) { + ip_conntrack_unexpect_related(exp); + return -1; + } + + /* Success */ + DEBUGP("ip_nat_q931: expect Call Forwarding " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), ntohs(exp->tuple.dst.u.tcp.port)); + + return 0; +} + +/****************************************************************************/ static int __init init(void) { BUG_ON(set_h245_addr_hook != NULL); @@ -496,6 +570,7 @@ static int __init init(void) BUG_ON(nat_rtp_rtcp_hook != NULL); BUG_ON(nat_t120_hook != NULL); BUG_ON(nat_h245_hook != NULL); + BUG_ON(nat_callforwarding_hook != NULL); BUG_ON(nat_q931_hook != NULL); set_h245_addr_hook = set_h245_addr; @@ -505,6 +580,7 @@ static int __init init(void) nat_rtp_rtcp_hook = nat_rtp_rtcp; nat_t120_hook = nat_t120; nat_h245_hook = nat_h245; + nat_callforwarding_hook = nat_callforwarding; nat_q931_hook = nat_q931; DEBUGP("ip_nat_h323: init success\n"); @@ -521,6 +597,7 @@ static void __exit fini(void) nat_rtp_rtcp_hook = NULL; nat_t120_hook = NULL; nat_h245_hook = NULL; + nat_callforwarding_hook = NULL; nat_q931_hook = NULL; synchronize_net(); } |