/* * H.323 connection tracking helper * * Copyright (c) 2006 Jing Min Zhao * * This source code is licensed under General Public License version 2. * * Based on the 'brute force' H.323 connection tracking module by * Jozsef Kadlecsik * * For more information, please see http://nath323.sourceforge.net/ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if 0 #define DEBUGP printk #else #define DEBUGP(format, args...) #endif /* Parameters */ static unsigned int default_rrq_ttl __read_mostly = 300; module_param(default_rrq_ttl, uint, 0600); MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ"); static int gkrouted_only __read_mostly = 1; module_param(gkrouted_only, int, 0600); MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper"); static int callforward_filter __read_mostly = 1; module_param(callforward_filter, bool, 0600); MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations " "if both endpoints are on different sides " "(determined by routing information)"); /* Hooks for NAT */ int (*set_h245_addr_hook) (struct sk_buff **pskb, unsigned char **data, int dataoff, H245_TransportAddress *taddr, union nf_conntrack_address *addr, __be16 port) __read_mostly; int (*set_h225_addr_hook) (struct sk_buff **pskb, unsigned char **data, int dataoff, TransportAddress *taddr, union nf_conntrack_address *addr, __be16 port) __read_mostly; int (*set_sig_addr_hook) (struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, TransportAddress *taddr, int count) __read_mostly; int (*set_ras_addr_hook) (struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, TransportAddress *taddr, int count) __read_mostly; int (*nat_rtp_rtcp_hook) (struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, H245_TransportAddress *taddr, __be16 port, __be16 rtp_port, struct nf_conntrack_expect *rtp_exp, struct nf_conntrack_expect *rtcp_exp) __read_mostly; int (*nat_t120_hook) (struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, H245_TransportAddress *taddr, __be16 port, struct nf_conntrack_expect *exp) __read_mostly; int (*nat_h245_hook) (struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, TransportAddress *taddr, __be16 port, struct nf_conntrack_expect *exp) __read_mostly; int (*nat_callforwarding_hook) (struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, TransportAddress *taddr, __be16 port, struct nf_conntrack_expect *exp) __read_mostly; int (*nat_q931_hook) (struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, TransportAddress *taddr, int idx, __be16 port, struct nf_conntrack_expect *exp) __read_mostly; static DEFINE_SPINLOCK(nf_h323_lock); static char *h323_buffer; static struct nf_conntrack_helper nf_conntrack_helper_h245; static struct nf_conntrack_helper nf_conntrack_helper_q931[]; static struct nf_conntrack_helper nf_conntrack_helper_ras[]; /****************************************************************************/ static int get_tpkt_data(struct sk_buff **pskb, unsigned int protoff, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int *datalen, int *dataoff) { struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; int dir = CTINFO2DIR(ctinfo); struct tcphdr _tcph, *th; int tcpdatalen; int tcpdataoff; unsigned char *tpkt; int tpktlen; int tpktoff; /* Get TCP header */ th = skb_header_pointer(*pskb, protoff, sizeof(_tcph), &_tcph); if (th == NULL) return 0; /* Get TCP data offset */ tcpdataoff = protoff + th->doff * 4; /* Get TCP data length */ tcpdatalen = (*pskb)->len - tcpdataoff; if (tcpdatalen <= 0) /* No TCP data */ goto clear_out; if (*data == NULL) { /* first TPKT */ /* Get first TPKT pointer */ tpkt = skb_header_pointer(*pskb, tcpdataoff, tcpdatalen, h323_buffer); BUG_ON(tpkt == NULL); /* Validate TPKT identifier */ if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) { /* Netmeeting sends TPKT header and data separately */ if (info->tpkt_len[dir] > 0) { DEBUGP("nf_ct_h323: previous packet " "indicated separate TPKT data of %hu " "bytes\n", info->tpkt_len[dir]); if (info->tpkt_len[dir] <= tcpdatalen) { /* Yes, there was a TPKT header * received */ *data = tpkt; *datalen = info->tpkt_len[dir]; *dataoff = 0; goto out; } /* Fragmented TPKT */ if (net_ratelimit()) printk("nf_ct_h323: " "fragmented TPKT\n"); goto clear_out; } /* It is not even a TPKT */ return 0; } tpktoff = 0; } else { /* Next TPKT */ tpktoff = *dataoff + *datalen; tcpdatalen -= tpktoff; if (tcpdatalen <= 4) /* No more TPKT */ goto clear_out; tpkt = *data + *datalen; /* Validate TPKT identifier */ if (tpkt[0] != 0x03 || tpkt[1] != 0) goto clear_out; } /* Validate TPKT length */ tpktlen = tpkt[2] * 256 + tpkt[3]; if (tpktlen < 4) goto clear_out; if (tpktlen > tcpdatalen) { if (tcpdatalen == 4) { /* Separate TPKT header */ /* Netmeeting sends TPKT header and data separately */ DEBUGP("nf_ct_h323: separate TPKT header indicates " "there will be TPKT data of %hu bytes\n", tpktlen - 4); info->tpkt_len[dir] = tpktlen - 4; return 0; } if (net_ratelimit()) printk("nf_ct_h323: incomplete TPKT (fragmented?)\n"); goto clear_out; } /* This is the encapsulated data */ *data = tpkt + 4; *datalen = tpktlen - 4; *dataoff = tpktoff + 4; out: /* Clear TPKT length */ info->tpkt_len[dir] = 0; return 1; clear_out: info->tpkt_len[dir] = 0; return 0; } /****************************************************************************/ static int get_h245_addr(struct nf_conn *ct, unsigned char *data, H245_TransportAddress *taddr, union nf_conntrack_address *addr, __be16 *port) { unsigned char *p; int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; int len; if (taddr->choice != eH245_TransportAddress_unicastAddress) return 0; switch (taddr->unicastAddress.choice) { case eUnicastAddress_iPAddress: if (family != AF_INET) return 0; p = data + taddr->unicastAddress.iPAddress.network; len = 4; break; case eUnicastAddress_iP6Address: if (family != AF_INET6) return 0; p = data + taddr->unicastAddress.iP6Address.network; len = 16; break; default: return 0; } memcpy(addr, p, len); memset((void *)addr + len, 0, sizeof(*addr) - len); memcpy(port, p + len, sizeof(__be16)); return 1; } /****************************************************************************/ static int expect_rtp_rtcp(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, H245_TransportAddress *taddr) { int dir = CTINFO2DIR(ctinfo); int ret = 0; __be16 port; __be16 rtp_port, rtcp_port; union nf_conntrack_address addr; struct nf_conntrack_expect *rtp_exp; struct nf_conntrack_expect *rtcp_exp; typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp; /* Read RTP or RTCP address */ if (!get_h245_addr(ct, *data, taddr, &addr, &port) || memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || port == 0) return 0; /* RTP port is even */ port &= htons(~1); rtp_port = port; rtcp_port = htons(ntohs(port) + 1); /* Create expect for RTP */ if ((rtp_exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(rtp_exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, IPPROTO_UDP, NULL, &rtp_port); /* Create expect for RTCP */ if ((rtcp_exp = nf_conntrack_expect_alloc(ct)) == NULL) { nf_conntrack_expect_put(rtp_exp); return -1; } nf_conntrack_expect_init(rtcp_exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, IPPROTO_UDP, NULL, &rtcp_port); if (memcmp(&ct->tuplehash[dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(ct->tuplehash[dir].tuple.src.u3)) && (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) && ct->status & IPS_NAT_MASK) { /* NAT needed */ ret = nat_rtp_rtcp(pskb, ct, ctinfo, data, dataoff, taddr, port, rtp_port, rtp_exp, rtcp_exp); } else { /* Conntrack only */ if (nf_conntrack_expect_related(rtp_exp) == 0) { if (nf_conntrack_expect_related(rtcp_exp) == 0) { DEBUGP("nf_ct_h323: expect RTP "); NF_CT_DUMP_TUPLE(&rtp_exp->tuple); DEBUGP("nf_ct_h323: expect RTCP "); NF_CT_DUMP_TUPLE(&rtcp_exp->tuple); } else { nf_conntrack_unexpect_related(rtp_exp); ret = -1; } } else ret = -1; } nf_conntrack_expect_put(rtp_exp); nf_conntrack_expect_put(rtcp_exp); return ret; } /****************************************************************************/ static int expect_t120(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, H245_TransportAddress *taddr) { int dir = CTINFO2DIR(ctinfo); int ret = 0; __be16 port; union nf_conntrack_address addr; struct nf_conntrack_expect *exp; typeof(nat_t120_hook) nat_t120; /* Read T.120 address */ if (!get_h245_addr(ct, *data, taddr, &addr, &port) || memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || port == 0) return 0; /* Create expect for T.120 connections */ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, IPPROTO_TCP, NULL, &port); exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */ if (memcmp(&ct->tuplehash[dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(ct->tuplehash[dir].tuple.src.u3)) && (nat_t120 = rcu_dereference(nat_t120_hook)) && ct->status & IPS_NAT_MASK) { /* NAT needed */ ret = nat_t120(pskb, ct, ctinfo, data, dataoff, taddr, port, exp); } else { /* Conntrack only */ if (nf_conntrack_expect_related(exp) == 0) { DEBUGP("nf_ct_h323: expect T.120 "); NF_CT_DUMP_TUPLE(&exp->tuple); } else ret = -1; } nf_conntrack_expect_put(exp); return ret; } /****************************************************************************/ static int process_h245_channel(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, H2250LogicalChannelParameters *channel) { int ret; if (channel->options & eH2250LogicalChannelParameters_mediaChannel) { /* RTP */ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff, &channel->mediaChannel); if (ret < 0) return -1; } if (channel-> options & eH2250LogicalChannelParameters_mediaControlChannel) { /* RTCP */ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff, &channel->mediaControlChannel); if (ret < 0) return -1; } return 0; } /****************************************************************************/ static int process_olc(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, OpenLogicalChannel *olc) { int ret; DEBUGP("nf_ct_h323: OpenLogicalChannel\n"); if (olc->forwardLogicalChannelParameters.multiplexParameters.choice == eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters) { ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff, &olc-> forwardLogicalChannelParameters. multiplexParameters. h2250LogicalChannelParameters); if (ret < 0) return -1; } if ((olc->options & eOpenLogicalChannel_reverseLogicalChannelParameters) && (olc->reverseLogicalChannelParameters.options & eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters) && (olc->reverseLogicalChannelParameters.multiplexParameters. choice == eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)) { ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff, &olc-> reverseLogicalChannelParameters. multiplexParameters. h2250LogicalChannelParameters); if (ret < 0) return -1; } if ((olc->options & eOpenLogicalChannel_separateStack) && olc->forwardLogicalChannelParameters.dataType.choice == eDataType_data && olc->forwardLogicalChannelParameters.dataType.data.application. choice == eDataApplicationCapability_application_t120 && olc->forwardLogicalChannelParameters.dataType.data.application. t120.choice == eDataProtocolCapability_separateLANStack && olc->separateStack.networkAddress.choice == eNetworkAccessParameters_networkAddress_localAreaAddress) { ret = expect_t120(pskb, ct, ctinfo, data, dataoff, &olc->separateStack.networkAddress. localAreaAddress); if (ret < 0) return -1; } return 0; } /****************************************************************************/ static int process_olca(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, OpenLogicalChannelAck *olca) { H2250LogicalChannelAckParameters *ack; int ret; DEBUGP("nf_ct_h323: OpenLogicalChannelAck\n"); if ((olca->options & eOpenLogicalChannelAck_reverseLogicalChannelParameters) && (olca->reverseLogicalChannelParameters.options & eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters) && (olca->reverseLogicalChannelParameters.multiplexParameters. choice == eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)) { ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff, &olca-> reverseLogicalChannelParameters. multiplexParameters. h2250LogicalChannelParameters); if (ret < 0) return -1; } if ((olca->options & eOpenLogicalChannelAck_forwardMultiplexAckParameters) && (olca->forwardMultiplexAckParameters.choice == eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters)) { ack = &olca->forwardMultiplexAckParameters. h2250LogicalChannelAckParameters; if (ack->options & eH2250LogicalChannelAckParameters_mediaChannel) { /* RTP */ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff, &ack->mediaChannel); if (ret < 0) return -1; } if (ack->options & eH2250LogicalChannelAckParameters_mediaControlChannel) { /* RTCP */ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff, &ack->mediaControlChannel); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_h245(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, MultimediaSystemControlMessage *mscm) { switch (mscm->choice) { case eMultimediaSystemControlMessage_request: if (mscm->request.choice == eRequestMessage_openLogicalChannel) { return process_olc(pskb, ct, ctinfo, data, dataoff, &mscm->request.openLogicalChannel); } DEBUGP("nf_ct_h323: H.245 Request %d\n", mscm->request.choice); break; case eMultimediaSystemControlMessage_response: if (mscm->response.choice == eResponseMessage_openLogicalChannelAck) { return process_olca(pskb, ct, ctinfo, data, dataoff, &mscm->response. openLogicalChannelAck); } DEBUGP("nf_ct_h323: H.245 Response %d\n", mscm->response.choice); break; default: DEBUGP("nf_ct_h323: H.245 signal %d\n", mscm->choice); break; } return 0; } /****************************************************************************/ static int h245_help(struct sk_buff **pskb, unsigned int protoff, struct nf_conn *ct, enum ip_conntrack_info ctinfo) { static MultimediaSystemControlMessage mscm; unsigned char *data = NULL; int datalen; int dataoff; int ret; /* Until there's been traffic both ways, don't look in packets. */ if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) { return NF_ACCEPT; } DEBUGP("nf_ct_h245: skblen = %u\n", (*pskb)->len); spin_lock_bh(&nf_h323_lock); /* Process each TPKT */ while (get_tpkt_data(pskb, protoff, ct, ctinfo, &data, &datalen, &dataoff)) { DEBUGP("nf_ct_h245: TPKT len=%d ", datalen); NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); /* Decode H.245 signal */ ret = DecodeMultimediaSystemControlMessage(data, datalen, &mscm); if (ret < 0) { if (net_ratelimit()) printk("nf_ct_h245: decoding error: %s\n", ret == H323_ERROR_BOUND ? "out of bound" : "out of range"); /* We don't drop when decoding error */ break; } /* Process H.245 signal */ if (process_h245(pskb, ct, ctinfo, &data, dataoff, &mscm) < 0) goto drop; } spin_unlock_bh(&nf_h323_lock); return NF_ACCEPT; drop: spin_unlock_bh(&nf_h323_lock); if (net_ratelimit()) printk("nf_ct_h245: packet dropped\n"); return NF_DROP; } /****************************************************************************/ static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = { .name = "H.245", .me = THIS_MODULE, .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */, .timeout = 240, .tuple.dst.protonum = IPPROTO_UDP, .mask.src.u.udp.port = __constant_htons(0xFFFF), .mask.dst.protonum = 0xFF, .help = h245_help }; /****************************************************************************/ int get_h225_addr(struct nf_conn *ct, unsigned char *data, TransportAddress *taddr, union nf_conntrack_address *addr, __be16 *port) { unsigned char *p; int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; int len; switch (taddr->choice) { case eTransportAddress_ipAddress: if (family != AF_INET) return 0; p = data + taddr->ipAddress.ip; len = 4; break; case eTransportAddress_ip6Address: if (family != AF_INET6) return 0; p = data + taddr->ip6Address.ip6; len = 16; break; default: return 0; } memcpy(addr, p, len); memset((void *)addr + len, 0, sizeof(*addr) - len); memcpy(port, p + len, sizeof(__be16)); return 1; } /****************************************************************************/ static int expect_h245(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, TransportAddress *taddr) { int dir = CTINFO2DIR(ctinfo); int ret = 0; __be16 port; union nf_conntrack_address addr; struct nf_conntrack_expect *exp; typeof(nat_h245_hook) nat_h245; /* Read h245Address */ if (!get_h225_addr(ct, *data, taddr, &addr, &port) || memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) || port == 0) return 0; /* Create expect for h245 connection */ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, IPPROTO_TCP, NULL, &port); exp->helper = &nf_conntrack_helper_h245; if (memcmp(&ct->tuplehash[dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(ct->tuplehash[dir].tuple.src.u3)) && (nat_h245 = rcu_dereference(nat_h245_hook)) && ct->status & IPS_NAT_MASK) { /* NAT needed */ ret = nat_h245(pskb, ct, ctinfo, data, dataoff, taddr, port, exp); } else { /* Conntrack only */ if (nf_conntrack_expect_related(exp) == 0) { DEBUGP("nf_ct_q931: expect H.245 "); NF_CT_DUMP_TUPLE(&exp->tuple); } else ret = -1; } nf_conntrack_expect_put(exp); return ret; } /* If the calling party is on the same side of the forward-to party, * we don't need to track the second call */ static int callforward_do_filter(union nf_conntrack_address *src, union nf_conntrack_address *dst, int family) { struct flowi fl1, fl2; int ret = 0; memset(&fl1, 0, sizeof(fl1)); memset(&fl2, 0, sizeof(fl2)); switch (family) { case AF_INET: { struct rtable *rt1, *rt2; fl1.fl4_dst = src->ip; fl2.fl4_dst = dst->ip; if (ip_route_output_key(&rt1, &fl1) == 0) { if (ip_route_output_key(&rt2, &fl2) == 0) { if (rt1->rt_gateway == rt2->rt_gateway && rt1->u.dst.dev == rt2->u.dst.dev) ret = 1; dst_release(&rt2->u.dst); } dst_release(&rt1->u.dst); } break; } #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) case AF_INET6: { struct rt6_info *rt1, *rt2; memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst)); memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst)); rt1 = (struct rt6_info *)ip6_route_output(NULL, &fl1); if (rt1) { rt2 = (struct rt6_info *)ip6_route_output(NULL, &fl2); if (rt2) { if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway, sizeof(rt1->rt6i_gateway)) && rt1->u.dst.dev == rt2->u.dst.dev) ret = 1; dst_release(&rt2->u.dst); } dst_release(&rt1->u.dst); } break; } #endif } return ret; } /****************************************************************************/ static int expect_callforwarding(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, TransportAddress *taddr) { int dir = CTINFO2DIR(ctinfo); int ret = 0; __be16 port; union nf_conntrack_address addr; struct nf_conntrack_expect *exp; typeof(nat_callforwarding_hook) nat_callforwarding; /* Read alternativeAddress */ if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0) return 0; /* If the calling party is on the same side of the forward-to party, * we don't need to track the second call */ if (callforward_filter && callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3, ct->tuplehash[!dir].tuple.src.l3num)) { DEBUGP("nf_ct_q931: Call Forwarding not tracked\n"); return 0; } /* Create expect for the second call leg */ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &addr, IPPROTO_TCP, NULL, &port); exp->helper = nf_conntrack_helper_q931; if (memcmp(&ct->tuplehash[dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(ct->tuplehash[dir].tuple.src.u3)) && (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) && ct->status & IPS_NAT_MASK) { /* Need NAT */ ret = nat_callforwarding(pskb, ct, ctinfo, data, dataoff, taddr, port, exp); } else { /* Conntrack only */ if (nf_conntrack_expect_related(exp) == 0) { DEBUGP("nf_ct_q931: expect Call Forwarding "); NF_CT_DUMP_TUPLE(&exp->tuple); } else ret = -1; } nf_conntrack_expect_put(exp); return ret; } /****************************************************************************/ static int process_setup(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, Setup_UUIE *setup) { int dir = CTINFO2DIR(ctinfo); int ret; int i; __be16 port; union nf_conntrack_address addr; typeof(set_h225_addr_hook) set_h225_addr; DEBUGP("nf_ct_q931: Setup\n"); if (setup->options & eSetup_UUIE_h245Address) { ret = expect_h245(pskb, ct, ctinfo, data, dataoff, &setup->h245Address); if (ret < 0) return -1; } set_h225_addr = rcu_dereference(set_h225_addr_hook); if ((setup->options & eSetup_UUIE_destCallSignalAddress) && (set_h225_addr) && ct->status && IPS_NAT_MASK && get_h225_addr(ct, *data, &setup->destCallSignalAddress, &addr, &port) && memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) { DEBUGP("nf_ct_q931: set destCallSignalAddress " NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n", NIP6(*(struct in6_addr *)&addr), ntohs(port), NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3), ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port)); ret = set_h225_addr(pskb, data, dataoff, &setup->destCallSignalAddress, &ct->tuplehash[!dir].tuple.src.u3, ct->tuplehash[!dir].tuple.src.u.tcp.port); if (ret < 0) return -1; } if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) && (set_h225_addr) && ct->status & IPS_NAT_MASK && get_h225_addr(ct, *data, &setup->sourceCallSignalAddress, &addr, &port) && memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) { DEBUGP("nf_ct_q931: set sourceCallSignalAddress " NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n", NIP6(*(struct in6_addr *)&addr), ntohs(port), NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3), ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port)); ret = set_h225_addr(pskb, data, dataoff, &setup->sourceCallSignalAddress, &ct->tuplehash[!dir].tuple.dst.u3, ct->tuplehash[!dir].tuple.dst.u.tcp.port); if (ret < 0) return -1; } if (setup->options & eSetup_UUIE_fastStart) { for (i = 0; i < setup->fastStart.count; i++) { ret = process_olc(pskb, ct, ctinfo, data, dataoff, &setup->fastStart.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_callproceeding(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, CallProceeding_UUIE *callproc) { int ret; int i; DEBUGP("nf_ct_q931: CallProceeding\n"); if (callproc->options & eCallProceeding_UUIE_h245Address) { ret = expect_h245(pskb, ct, ctinfo, data, dataoff, &callproc->h245Address); if (ret < 0) return -1; } if (callproc->options & eCallProceeding_UUIE_fastStart) { for (i = 0; i < callproc->fastStart.count; i++) { ret = process_olc(pskb, ct, ctinfo, data, dataoff, &callproc->fastStart.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_connect(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, Connect_UUIE *connect) { int ret; int i; DEBUGP("nf_ct_q931: Connect\n"); if (connect->options & eConnect_UUIE_h245Address) { ret = expect_h245(pskb, ct, ctinfo, data, dataoff, &connect->h245Address); if (ret < 0) return -1; } if (connect->options & eConnect_UUIE_fastStart) { for (i = 0; i < connect->fastStart.count; i++) { ret = process_olc(pskb, ct, ctinfo, data, dataoff, &connect->fastStart.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_alerting(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, Alerting_UUIE *alert) { int ret; int i; DEBUGP("nf_ct_q931: Alerting\n"); if (alert->options & eAlerting_UUIE_h245Address) { ret = expect_h245(pskb, ct, ctinfo, data, dataoff, &alert->h245Address); if (ret < 0) return -1; } if (alert->options & eAlerting_UUIE_fastStart) { for (i = 0; i < alert->fastStart.count; i++) { ret = process_olc(pskb, ct, ctinfo, data, dataoff, &alert->fastStart.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_information(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, Information_UUIE *info) { int ret; int i; DEBUGP("nf_ct_q931: Information\n"); if (info->options & eInformation_UUIE_fastStart) { for (i = 0; i < info->fastStart.count; i++) { ret = process_olc(pskb, ct, ctinfo, data, dataoff, &info->fastStart.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_facility(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, Facility_UUIE *facility) { int ret; int i; DEBUGP("nf_ct_q931: Facility\n"); if (facility->reason.choice == eFacilityReason_callForwarded) { if (facility->options & eFacility_UUIE_alternativeAddress) return expect_callforwarding(pskb, ct, ctinfo, data, dataoff, &facility-> alternativeAddress); return 0; } if (facility->options & eFacility_UUIE_h245Address) { ret = expect_h245(pskb, ct, ctinfo, data, dataoff, &facility->h245Address); if (ret < 0) return -1; } if (facility->options & eFacility_UUIE_fastStart) { for (i = 0; i < facility->fastStart.count; i++) { ret = process_olc(pskb, ct, ctinfo, data, dataoff, &facility->fastStart.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_progress(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, Progress_UUIE *progress) { int ret; int i; DEBUGP("nf_ct_q931: Progress\n"); if (progress->options & eProgress_UUIE_h245Address) { ret = expect_h245(pskb, ct, ctinfo, data, dataoff, &progress->h245Address); if (ret < 0) return -1; } if (progress->options & eProgress_UUIE_fastStart) { for (i = 0; i < progress->fastStart.count; i++) { ret = process_olc(pskb, ct, ctinfo, data, dataoff, &progress->fastStart.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int process_q931(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, int dataoff, Q931 *q931) { H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu; int i; int ret = 0; switch (pdu->h323_message_body.choice) { case eH323_UU_PDU_h323_message_body_setup: ret = process_setup(pskb, ct, ctinfo, data, dataoff, &pdu->h323_message_body.setup); break; case eH323_UU_PDU_h323_message_body_callProceeding: ret = process_callproceeding(pskb, ct, ctinfo, data, dataoff, &pdu->h323_message_body. callProceeding); break; case eH323_UU_PDU_h323_message_body_connect: ret = process_connect(pskb, ct, ctinfo, data, dataoff, &pdu->h323_message_body.connect); break; case eH323_UU_PDU_h323_message_body_alerting: ret = process_alerting(pskb, ct, ctinfo, data, dataoff, &pdu->h323_message_body.alerting); break; case eH323_UU_PDU_h323_message_body_information: ret = process_information(pskb, ct, ctinfo, data, dataoff, &pdu->h323_message_body. information); break; case eH323_UU_PDU_h323_message_body_facility: ret = process_facility(pskb, ct, ctinfo, data, dataoff, &pdu->h323_message_body.facility); break; case eH323_UU_PDU_h323_message_body_progress: ret = process_progress(pskb, ct, ctinfo, data, dataoff, &pdu->h323_message_body.progress); break; default: DEBUGP("nf_ct_q931: Q.931 signal %d\n", pdu->h323_message_body.choice); break; } if (ret < 0) return -1; if (pdu->options & eH323_UU_PDU_h245Control) { for (i = 0; i < pdu->h245Control.count; i++) { ret = process_h245(pskb, ct, ctinfo, data, dataoff, &pdu->h245Control.item[i]); if (ret < 0) return -1; } } return 0; } /****************************************************************************/ static int q931_help(struct sk_buff **pskb, unsigned int protoff, struct nf_conn *ct, enum ip_conntrack_info ctinfo) { static Q931 q931; unsigned char *data = NULL; int datalen; int dataoff; int ret; /* Until there's been traffic both ways, don't look in packets. */ if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) { return NF_ACCEPT; } DEBUGP("nf_ct_q931: skblen = %u\n", (*pskb)->len); spin_lock_bh(&nf_h323_lock); /* Process each TPKT */ while (get_tpkt_data(pskb, protoff, ct, ctinfo, &data, &datalen, &dataoff)) { DEBUGP("nf_ct_q931: TPKT len=%d ", datalen); NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); /* Decode Q.931 signal */ ret = DecodeQ931(data, datalen, &q931); if (ret < 0) { if (net_ratelimit()) printk("nf_ct_q931: decoding error: %s\n", ret == H323_ERROR_BOUND ? "out of bound" : "out of range"); /* We don't drop when decoding error */ break; } /* Process Q.931 signal */ if (process_q931(pskb, ct, ctinfo, &data, dataoff, &q931) < 0) goto drop; } spin_unlock_bh(&nf_h323_lock); return NF_ACCEPT; drop: spin_unlock_bh(&nf_h323_lock); if (net_ratelimit()) printk("nf_ct_q931: packet dropped\n"); return NF_DROP; } /****************************************************************************/ static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = { { .name = "Q.931", .me = THIS_MODULE, /* T.120 and H.245 */ .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4, .timeout = 240, .tuple.src.l3num = AF_INET, .tuple.src.u.tcp.port = __constant_htons(Q931_PORT), .tuple.dst.protonum = IPPROTO_TCP, .mask.src.l3num = 0xFFFF, .mask.src.u.tcp.port = __constant_htons(0xFFFF), .mask.dst.protonum = 0xFF, .help = q931_help }, { .name = "Q.931", .me = THIS_MODULE, /* T.120 and H.245 */ .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4, .timeout = 240, .tuple.src.l3num = AF_INET6, .tuple.src.u.tcp.port = __constant_htons(Q931_PORT), .tuple.dst.protonum = IPPROTO_TCP, .mask.src.l3num = 0xFFFF, .mask.src.u.tcp.port = __constant_htons(0xFFFF), .mask.dst.protonum = 0xFF, .help = q931_help }, }; /****************************************************************************/ static unsigned char *get_udp_data(struct sk_buff **pskb, unsigned int protoff, int *datalen) { struct udphdr _uh, *uh; int dataoff; uh = skb_header_pointer(*pskb, protoff, sizeof(_uh), &_uh); if (uh == NULL) return NULL; dataoff = protoff + sizeof(_uh); if (dataoff >= (*pskb)->len) return NULL; *datalen = (*pskb)->len - dataoff; return skb_header_pointer(*pskb, dataoff, *datalen, h323_buffer); } /****************************************************************************/ static struct nf_conntrack_expect *find_expect(struct nf_conn *ct, union nf_conntrack_address *addr, __be16 port) { struct nf_conntrack_expect *exp; struct nf_conntrack_tuple tuple; memset(&tuple.src.u3, 0, sizeof(tuple.src.u3)); tuple.src.u.tcp.port = 0; memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3)); tuple.dst.u.tcp.port = port; tuple.dst.protonum = IPPROTO_TCP; exp = __nf_conntrack_expect_find(&tuple); if (exp && exp->master == ct) return exp; return NULL; } /****************************************************************************/ static int set_expect_timeout(struct nf_conntrack_expect *exp, unsigned timeout) { if (!exp || !del_timer(&exp->timeout)) return 0; exp->timeout.expires = jiffies + timeout * HZ; add_timer(&exp->timeout); return 1; } /****************************************************************************/ static int expect_q931(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, TransportAddress *taddr, int count) { struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; int dir = CTINFO2DIR(ctinfo); int ret = 0; int i; __be16 port; union nf_conntrack_address addr; struct nf_conntrack_expect *exp; typeof(nat_q931_hook) nat_q931; /* Look for the first related address */ for (i = 0; i < count; i++) { if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) && memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) == 0 && port != 0) break; } if (i >= count) /* Not found */ return 0; /* Create expect for Q.931 */ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num, gkrouted_only ? /* only accept calls from GK? */ &ct->tuplehash[!dir].tuple.src.u3 : NULL, &ct->tuplehash[!dir].tuple.dst.u3, IPPROTO_TCP, NULL, &port); exp->helper = nf_conntrack_helper_q931; exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */ nat_q931 = rcu_dereference(nat_q931_hook); if (nat_q931 && ct->status & IPS_NAT_MASK) { /* Need NAT */ ret = nat_q931(pskb, ct, ctinfo, data, taddr, i, port, exp); } else { /* Conntrack only */ if (nf_conntrack_expect_related(exp) == 0) { DEBUGP("nf_ct_ras: expect Q.931 "); NF_CT_DUMP_TUPLE(&exp->tuple); /* Save port for looking up expect in processing RCF */ info->sig_port[dir] = port; } else ret = -1; } nf_conntrack_expect_put(exp); return ret; } /****************************************************************************/ static int process_grq(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, GatekeeperRequest *grq) { typeof(set_ras_addr_hook) set_ras_addr; DEBUGP("nf_ct_ras: GRQ\n"); set_ras_addr = rcu_dereference(set_ras_addr_hook); if (set_ras_addr && ct->status & IPS_NAT_MASK) /* NATed */ return set_ras_addr(pskb, ct, ctinfo, data, &grq->rasAddress, 1); return 0; } /****************************************************************************/ static int process_gcf(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, GatekeeperConfirm *gcf) { int dir = CTINFO2DIR(ctinfo); int ret = 0; __be16 port; union nf_conntrack_address addr; struct nf_conntrack_expect *exp; DEBUGP("nf_ct_ras: GCF\n"); if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port)) return 0; /* Registration port is the same as discovery port */ if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && port == ct->tuplehash[dir].tuple.src.u.udp.port) return 0; /* Avoid RAS expectation loops. A GCF is never expected. */ if (test_bit(IPS_EXPECTED_BIT, &ct->status)) return 0; /* Need new expect */ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &addr, IPPROTO_UDP, NULL, &port); exp->helper = nf_conntrack_helper_ras; if (nf_conntrack_expect_related(exp) == 0) { DEBUGP("nf_ct_ras: expect RAS "); NF_CT_DUMP_TUPLE(&exp->tuple); } else ret = -1; nf_conntrack_expect_put(exp); return ret; } /****************************************************************************/ static int process_rrq(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, RegistrationRequest *rrq) { struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; int ret; typeof(set_ras_addr_hook) set_ras_addr; DEBUGP("nf_ct_ras: RRQ\n"); ret = expect_q931(pskb, ct, ctinfo, data, rrq->callSignalAddress.item, rrq->callSignalAddress.count); if (ret < 0) return -1; set_ras_addr = rcu_dereference(set_ras_addr_hook); if (set_ras_addr && ct->status & IPS_NAT_MASK) { ret = set_ras_addr(pskb, ct, ctinfo, data, rrq->rasAddress.item, rrq->rasAddress.count); if (ret < 0) return -1; } if (rrq->options & eRegistrationRequest_timeToLive) { DEBUGP("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive); info->timeout = rrq->timeToLive; } else info->timeout = default_rrq_ttl; return 0; } /****************************************************************************/ static int process_rcf(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, RegistrationConfirm *rcf) { struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; int dir = CTINFO2DIR(ctinfo); int ret; struct nf_conntrack_expect *exp; typeof(set_sig_addr_hook) set_sig_addr; DEBUGP("nf_ct_ras: RCF\n"); set_sig_addr = rcu_dereference(set_sig_addr_hook); if (set_sig_addr && ct->status & IPS_NAT_MASK) { ret = set_sig_addr(pskb, ct, ctinfo, data, rcf->callSignalAddress.item, rcf->callSignalAddress.count); if (ret < 0) return -1; } if (rcf->options & eRegistrationConfirm_timeToLive) { DEBUGP("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive); info->timeout = rcf->timeToLive; } if (info->timeout > 0) { DEBUGP ("nf_ct_ras: set RAS connection timeout to %u seconds\n", info->timeout); nf_ct_refresh(ct, *pskb, info->timeout * HZ); /* Set expect timeout */ read_lock_bh(&nf_conntrack_lock); exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3, info->sig_port[!dir]); if (exp) { DEBUGP("nf_ct_ras: set Q.931 expect " "timeout to %u seconds for", info->timeout); NF_CT_DUMP_TUPLE(&exp->tuple); set_expect_timeout(exp, info->timeout); } read_unlock_bh(&nf_conntrack_lock); } return 0; } /****************************************************************************/ static int process_urq(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, UnregistrationRequest *urq) { struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; int dir = CTINFO2DIR(ctinfo); int ret; typeof(set_sig_addr_hook) set_sig_addr; DEBUGP("nf_ct_ras: URQ\n"); set_sig_addr = rcu_dereference(set_sig_addr_hook); if (set_sig_addr && ct->status & IPS_NAT_MASK) { ret = set_sig_addr(pskb, ct, ctinfo, data, urq->callSignalAddress.item, urq->callSignalAddress.count); if (ret < 0) return -1; } /* Clear old expect */ nf_ct_remove_expectations(ct); info->sig_port[dir] = 0; info->sig_port[!dir] = 0; /* Give it 30 seconds for UCF or URJ */ nf_ct_refresh(ct, *pskb, 30 * HZ); return 0; } /****************************************************************************/ static int process_arq(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, AdmissionRequest *arq) { struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; int dir = CTINFO2DIR(ctinfo); __be16 port; union nf_conntrack_address addr; typeof(set_h225_addr_hook) set_h225_addr; DEBUGP("nf_ct_ras: ARQ\n"); set_h225_addr = rcu_dereference(set_h225_addr_hook); if ((arq->options & eAdmissionRequest_destCallSignalAddress) && get_h225_addr(ct, *data, &arq->destCallSignalAddress, &addr, &port) && !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && port == info->sig_port[dir] && set_h225_addr && ct->status & IPS_NAT_MASK) { /* Answering ARQ */ return set_h225_addr(pskb, data, 0, &arq->destCallSignalAddress, &ct->tuplehash[!dir].tuple.dst.u3, info->sig_port[!dir]); } if ((arq->options & eAdmissionRequest_srcCallSignalAddress) && get_h225_addr(ct, *data, &arq->srcCallSignalAddress, &addr, &port) && !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) && set_h225_addr && ct->status & IPS_NAT_MASK) { /* Calling ARQ */ return set_h225_addr(pskb, data, 0, &arq->srcCallSignalAddress, &ct->tuplehash[!dir].tuple.dst.u3, port); } return 0; } /****************************************************************************/ static int process_acf(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, AdmissionConfirm *acf) { int dir = CTINFO2DIR(ctinfo); int ret = 0; __be16 port; union nf_conntrack_address addr; struct nf_conntrack_expect *exp; typeof(set_sig_addr_hook) set_sig_addr; DEBUGP("nf_ct_ras: ACF\n"); if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress, &addr, &port)) return 0; if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) { /* Answering ACF */ set_sig_addr = rcu_dereference(set_sig_addr_hook); if (set_sig_addr && ct->status & IPS_NAT_MASK) return set_sig_addr(pskb, ct, ctinfo, data, &acf->destCallSignalAddress, 1); return 0; } /* Need new expect */ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &addr, IPPROTO_TCP, NULL, &port); exp->flags = NF_CT_EXPECT_PERMANENT; exp->helper = nf_conntrack_helper_q931; if (nf_conntrack_expect_related(exp) == 0) { DEBUGP("nf_ct_ras: expect Q.931 "); NF_CT_DUMP_TUPLE(&exp->tuple); } else ret = -1; nf_conntrack_expect_put(exp); return ret; } /****************************************************************************/ static int process_lrq(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, LocationRequest *lrq) { typeof(set_ras_addr_hook) set_ras_addr; DEBUGP("nf_ct_ras: LRQ\n"); set_ras_addr = rcu_dereference(set_ras_addr_hook); if (set_ras_addr && ct->status & IPS_NAT_MASK) return set_ras_addr(pskb, ct, ctinfo, data, &lrq->replyAddress, 1); return 0; } /****************************************************************************/ static int process_lcf(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, LocationConfirm *lcf) { int dir = CTINFO2DIR(ctinfo); int ret = 0; __be16 port; union nf_conntrack_address addr; struct nf_conntrack_expect *exp; DEBUGP("nf_ct_ras: LCF\n"); if (!get_h225_addr(ct, *data, &lcf->callSignalAddress, &addr, &port)) return 0; /* Need new expect for call signal */ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL) return -1; nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num, &ct->tuplehash[!dir].tuple.src.u3, &addr, IPPROTO_TCP, NULL, &port); exp->flags = NF_CT_EXPECT_PERMANENT; exp->helper = nf_conntrack_helper_q931; if (nf_conntrack_expect_related(exp) == 0) { DEBUGP("nf_ct_ras: expect Q.931 "); NF_CT_DUMP_TUPLE(&exp->tuple); } else ret = -1; nf_conntrack_expect_put(exp); /* Ignore rasAddress */ return ret; } /****************************************************************************/ static int process_irr(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, InfoRequestResponse *irr) { int ret; typeof(set_ras_addr_hook) set_ras_addr; typeof(set_sig_addr_hook) set_sig_addr; DEBUGP("nf_ct_ras: IRR\n"); set_ras_addr = rcu_dereference(set_ras_addr_hook); if (set_ras_addr && ct->status & IPS_NAT_MASK) { ret = set_ras_addr(pskb, ct, ctinfo, data, &irr->rasAddress, 1); if (ret < 0) return -1; } set_sig_addr = rcu_dereference(set_sig_addr_hook); if (set_sig_addr && ct->status & IPS_NAT_MASK) { ret = set_sig_addr(pskb, ct, ctinfo, data, irr->callSignalAddress.item, irr->callSignalAddress.count); if (ret < 0) return -1; } return 0; } /****************************************************************************/ static int process_ras(struct sk_buff **pskb, struct nf_conn *ct, enum ip_conntrack_info ctinfo, unsigned char **data, RasMessage *ras) { switch (ras->choice) { case eRasMessage_gatekeeperRequest: return process_grq(pskb, ct, ctinfo, data, &ras->gatekeeperRequest); case eRasMessage_gatekeeperConfirm: return process_gcf(pskb, ct, ctinfo, data, &ras->gatekeeperConfirm); case eRasMessage_registrationRequest: return process_rrq(pskb, ct, ctinfo, data, &ras->registrationRequest); case eRasMessage_registrationConfirm: return process_rcf(pskb, ct, ctinfo, data, &ras->registrationConfirm); case eRasMessage_unregistrationRequest: return process_urq(pskb, ct, ctinfo, data, &ras->unregistrationRequest); case eRasMessage_admissionRequest: return process_arq(pskb, ct, ctinfo, data, &ras->admissionRequest); case eRasMessage_admissionConfirm: return process_acf(pskb, ct, ctinfo, data, &ras->admissionConfirm); case eRasMessage_locationRequest: return process_lrq(pskb, ct, ctinfo, data, &ras->locationRequest); case eRasMessage_locationConfirm: return process_lcf(pskb, ct, ctinfo, data, &ras->locationConfirm); case eRasMessage_infoRequestResponse: return process_irr(pskb, ct, ctinfo, data, &ras->infoRequestResponse); default: DEBUGP("nf_ct_ras: RAS message %d\n", ras->choice); break; } return 0; } /****************************************************************************/ static int ras_help(struct sk_buff **pskb, unsigned int protoff, struct nf_conn *ct, enum ip_conntrack_info ctinfo) { static RasMessage ras; unsigned char *data; int datalen = 0; int ret; DEBUGP("nf_ct_ras: skblen = %u\n", (*pskb)->len); spin_lock_bh(&nf_h323_lock); /* Get UDP data */ data = get_udp_data(pskb, protoff, &datalen); if (data == NULL) goto accept; DEBUGP("nf_ct_ras: RAS message len=%d ", datalen); NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple); /* Decode RAS message */ ret = DecodeRasMessage(data, datalen, &ras); if (ret < 0) { if (net_ratelimit()) printk("nf_ct_ras: decoding error: %s\n", ret == H323_ERROR_BOUND ? "out of bound" : "out of range"); goto accept; } /* Process RAS message */ if (process_ras(pskb, ct, ctinfo, &data, &ras) < 0) goto drop; accept: spin_unlock_bh(&nf_h323_lock); return NF_ACCEPT; drop: spin_unlock_bh(&nf_h323_lock); if (net_ratelimit()) printk("nf_ct_ras: packet dropped\n"); return NF_DROP; } /****************************************************************************/ static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = { { .name = "RAS", .me = THIS_MODULE, .max_expected = 32, .timeout = 240, .tuple.src.l3num = AF_INET, .tuple.src.u.udp.port = __constant_htons(RAS_PORT), .tuple.dst.protonum = IPPROTO_UDP, .mask.src.l3num = 0xFFFF, .mask.src.u.udp.port = __constant_htons(0xFFFF), .mask.dst.protonum = 0xFF, .help = ras_help, }, { .name = "RAS", .me = THIS_MODULE, .max_expected = 32, .timeout = 240, .tuple.src.l3num = AF_INET6, .tuple.src.u.udp.port = __constant_htons(RAS_PORT), .tuple.dst.protonum = IPPROTO_UDP, .mask.src.l3num = 0xFFFF, .mask.src.u.udp.port = __constant_htons(0xFFFF), .mask.dst.protonum = 0xFF, .help = ras_help, }, }; /****************************************************************************/ static void __exit nf_conntrack_h323_fini(void) { nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]); nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]); nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]); nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]); kfree(h323_buffer); DEBUGP("nf_ct_h323: fini\n"); } /****************************************************************************/ static int __init nf_conntrack_h323_init(void) { int ret; h323_buffer = kmalloc(65536, GFP_KERNEL); if (!h323_buffer) return -ENOMEM; ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]); if (ret < 0) goto err1; ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]); if (ret < 0) goto err2; ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]); if (ret < 0) goto err3; ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]); if (ret < 0) goto err4; DEBUGP("nf_ct_h323: init success\n"); return 0; err4: nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]); err3: nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]); err2: nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]); err1: return ret; } /****************************************************************************/ module_init(nf_conntrack_h323_init); module_exit(nf_conntrack_h323_fini); EXPORT_SYMBOL_GPL(get_h225_addr); EXPORT_SYMBOL_GPL(set_h245_addr_hook); EXPORT_SYMBOL_GPL(set_h225_addr_hook); EXPORT_SYMBOL_GPL(set_sig_addr_hook); EXPORT_SYMBOL_GPL(set_ras_addr_hook); EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook); EXPORT_SYMBOL_GPL(nat_t120_hook); EXPORT_SYMBOL_GPL(nat_h245_hook); EXPORT_SYMBOL_GPL(nat_callforwarding_hook); EXPORT_SYMBOL_GPL(nat_q931_hook); MODULE_AUTHOR("Jing Min Zhao "); MODULE_DESCRIPTION("H.323 connection tracking helper"); MODULE_LICENSE("GPL"); MODULE_ALIAS("ip_conntrack_h323");