| 1 | --- a/include/linux/netfilter/nf_conntrack_sip.h |
| 2 | +++ b/include/linux/netfilter/nf_conntrack_sip.h |
| 3 | @@ -2,12 +2,15 @@ |
| 4 | #define __NF_CONNTRACK_SIP_H__ |
| 5 | #ifdef __KERNEL__ |
| 6 | |
| 7 | +#include <linux/types.h> |
| 8 | + |
| 9 | #define SIP_PORT 5060 |
| 10 | #define SIP_TIMEOUT 3600 |
| 11 | |
| 12 | struct nf_ct_sip_master { |
| 13 | unsigned int register_cseq; |
| 14 | unsigned int invite_cseq; |
| 15 | + __be16 forced_dport; |
| 16 | }; |
| 17 | |
| 18 | enum sip_expectation_classes { |
| 19 | --- a/net/ipv4/netfilter/nf_nat_sip.c |
| 20 | +++ b/net/ipv4/netfilter/nf_nat_sip.c |
| 21 | @@ -73,6 +73,7 @@ static int map_addr(struct sk_buff *skb, |
| 22 | enum ip_conntrack_info ctinfo; |
| 23 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 24 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 25 | + struct nf_conn_help *help = nfct_help(ct); |
| 26 | char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; |
| 27 | unsigned int buflen; |
| 28 | __be32 newaddr; |
| 29 | @@ -85,7 +86,8 @@ static int map_addr(struct sk_buff *skb, |
| 30 | } else if (ct->tuplehash[dir].tuple.dst.u3.ip == addr->ip && |
| 31 | ct->tuplehash[dir].tuple.dst.u.udp.port == port) { |
| 32 | newaddr = ct->tuplehash[!dir].tuple.src.u3.ip; |
| 33 | - newport = ct->tuplehash[!dir].tuple.src.u.udp.port; |
| 34 | + newport = help->help.ct_sip_info.forced_dport ? : |
| 35 | + ct->tuplehash[!dir].tuple.src.u.udp.port; |
| 36 | } else |
| 37 | return 1; |
| 38 | |
| 39 | @@ -121,6 +123,7 @@ static unsigned int ip_nat_sip(struct sk |
| 40 | enum ip_conntrack_info ctinfo; |
| 41 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 42 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 43 | + struct nf_conn_help *help = nfct_help(ct); |
| 44 | unsigned int coff, matchoff, matchlen; |
| 45 | enum sip_header_types hdr; |
| 46 | union nf_inet_addr addr; |
| 47 | @@ -229,6 +232,20 @@ next: |
| 48 | !map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_TO)) |
| 49 | return NF_DROP; |
| 50 | |
| 51 | + /* Mangle destination port for Cisco phones, then fix up checksums */ |
| 52 | + if (dir == IP_CT_DIR_REPLY && help->help.ct_sip_info.forced_dport) { |
| 53 | + struct udphdr *uh; |
| 54 | + |
| 55 | + if (!skb_make_writable(skb, skb->len)) |
| 56 | + return NF_DROP; |
| 57 | + |
| 58 | + uh = (struct udphdr *)(skb->data + ip_hdrlen(skb)); |
| 59 | + uh->dest = help->help.ct_sip_info.forced_dport; |
| 60 | + |
| 61 | + if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, 0, 0, NULL, 0)) |
| 62 | + return NF_DROP; |
| 63 | + } |
| 64 | + |
| 65 | return NF_ACCEPT; |
| 66 | } |
| 67 | |
| 68 | @@ -280,8 +297,10 @@ static unsigned int ip_nat_sip_expect(st |
| 69 | enum ip_conntrack_info ctinfo; |
| 70 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 71 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 72 | + struct nf_conn_help *help = nfct_help(ct); |
| 73 | __be32 newip; |
| 74 | u_int16_t port; |
| 75 | + __be16 srcport; |
| 76 | char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")]; |
| 77 | unsigned buflen; |
| 78 | |
| 79 | @@ -294,8 +313,9 @@ static unsigned int ip_nat_sip_expect(st |
| 80 | /* If the signalling port matches the connection's source port in the |
| 81 | * original direction, try to use the destination port in the opposite |
| 82 | * direction. */ |
| 83 | - if (exp->tuple.dst.u.udp.port == |
| 84 | - ct->tuplehash[dir].tuple.src.u.udp.port) |
| 85 | + srcport = help->help.ct_sip_info.forced_dport ? : |
| 86 | + ct->tuplehash[dir].tuple.src.u.udp.port; |
| 87 | + if (exp->tuple.dst.u.udp.port == srcport) |
| 88 | port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port); |
| 89 | else |
| 90 | port = ntohs(exp->tuple.dst.u.udp.port); |
| 91 | --- a/net/netfilter/nf_conntrack_sip.c |
| 92 | +++ b/net/netfilter/nf_conntrack_sip.c |
| 93 | @@ -1363,8 +1363,25 @@ static int process_sip_request(struct sk |
| 94 | { |
| 95 | enum ip_conntrack_info ctinfo; |
| 96 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 97 | + struct nf_conn_help *help = nfct_help(ct); |
| 98 | + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 99 | unsigned int matchoff, matchlen; |
| 100 | unsigned int cseq, i; |
| 101 | + union nf_inet_addr addr; |
| 102 | + __be16 port; |
| 103 | + |
| 104 | + /* Many Cisco IP phones use a high source port for SIP requests, but |
| 105 | + * listen for the response on port 5060. If we are the local |
| 106 | + * router for one of these phones, save the port number from the |
| 107 | + * Via: header so that nf_nat_sip can redirect the responses to |
| 108 | + * the correct port. |
| 109 | + */ |
| 110 | + if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, |
| 111 | + SIP_HDR_VIA_UDP, NULL, &matchoff, |
| 112 | + &matchlen, &addr, &port) > 0 && |
| 113 | + port != ct->tuplehash[dir].tuple.src.u.udp.port && |
| 114 | + nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3)) |
| 115 | + help->help.ct_sip_info.forced_dport = port; |
| 116 | |
| 117 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { |
| 118 | const struct sip_handler *handler; |
| 119 | |
