| /* |
| * H.323 connection tracking helper |
| * |
| * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net> |
| * |
| * This source code is licensed under General Public License version 2. |
| * |
| * Based on the 'brute force' H.323 connection tracking module by |
| * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> |
| * |
| * For more information, please see http://nath323.sourceforge.net/ |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/ctype.h> |
| #include <linux/inet.h> |
| #include <linux/in.h> |
| #include <linux/ip.h> |
| #include <linux/udp.h> |
| #include <linux/tcp.h> |
| #include <linux/skbuff.h> |
| #include <net/route.h> |
| #include <net/ip6_route.h> |
| |
| #include <net/netfilter/nf_conntrack.h> |
| #include <net/netfilter/nf_conntrack_core.h> |
| #include <net/netfilter/nf_conntrack_tuple.h> |
| #include <net/netfilter/nf_conntrack_expect.h> |
| #include <net/netfilter/nf_conntrack_ecache.h> |
| #include <net/netfilter/nf_conntrack_helper.h> |
| #include <linux/netfilter/nf_conntrack_h323.h> |
| |
| /* 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 *skb, |
| unsigned char **data, int dataoff, |
| H245_TransportAddress *taddr, |
| union nf_inet_addr *addr, __be16 port) |
| __read_mostly; |
| int (*set_h225_addr_hook) (struct sk_buff *skb, |
| unsigned char **data, int dataoff, |
| TransportAddress *taddr, |
| union nf_inet_addr *addr, __be16 port) |
| __read_mostly; |
| int (*set_sig_addr_hook) (struct sk_buff *skb, |
| 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 *skb, |
| 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 *skb, |
| 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 *skb, |
| 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 *skb, |
| 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 *skb, |
| 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 *skb, |
| 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 *skb, 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); |
| const struct tcphdr *th; |
| struct tcphdr _tcph; |
| int tcpdatalen; |
| int tcpdataoff; |
| unsigned char *tpkt; |
| int tpktlen; |
| int tpktoff; |
| |
| /* Get TCP header */ |
| th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
| if (th == NULL) |
| return 0; |
| |
| /* Get TCP data offset */ |
| tcpdataoff = protoff + th->doff * 4; |
| |
| /* Get TCP data length */ |
| tcpdatalen = skb->len - tcpdataoff; |
| if (tcpdatalen <= 0) /* No TCP data */ |
| goto clear_out; |
| |
| if (*data == NULL) { /* first TPKT */ |
| /* Get first TPKT pointer */ |
| tpkt = skb_header_pointer(skb, 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) { |
| pr_debug("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 */ |
| pr_debug("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 */ |
| pr_debug("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, const unsigned char *data, |
| H245_TransportAddress *taddr, |
| union nf_inet_addr *addr, __be16 *port) |
| { |
| const unsigned char *p; |
| int len; |
| |
| if (taddr->choice != eH245_TransportAddress_unicastAddress) |
| return 0; |
| |
| switch (taddr->unicastAddress.choice) { |
| case eUnicastAddress_iPAddress: |
| if (nf_ct_l3num(ct) != AF_INET) |
| return 0; |
| p = data + taddr->unicastAddress.iPAddress.network; |
| len = 4; |
| break; |
| case eUnicastAddress_iP6Address: |
| if (nf_ct_l3num(ct) != 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 *skb, 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_inet_addr 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_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &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_ct_expect_alloc(ct)) == NULL) { |
| nf_ct_expect_put(rtp_exp); |
| return -1; |
| } |
| nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &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(skb, ct, ctinfo, data, dataoff, |
| taddr, port, rtp_port, rtp_exp, rtcp_exp); |
| } else { /* Conntrack only */ |
| if (nf_ct_expect_related(rtp_exp) == 0) { |
| if (nf_ct_expect_related(rtcp_exp) == 0) { |
| pr_debug("nf_ct_h323: expect RTP "); |
| nf_ct_dump_tuple(&rtp_exp->tuple); |
| pr_debug("nf_ct_h323: expect RTCP "); |
| nf_ct_dump_tuple(&rtcp_exp->tuple); |
| } else { |
| nf_ct_unexpect_related(rtp_exp); |
| ret = -1; |
| } |
| } else |
| ret = -1; |
| } |
| |
| nf_ct_expect_put(rtp_exp); |
| nf_ct_expect_put(rtcp_exp); |
| |
| return ret; |
| } |
| |
| /****************************************************************************/ |
| static int expect_t120(struct sk_buff *skb, |
| 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_inet_addr 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_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &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(skb, ct, ctinfo, data, dataoff, taddr, |
| port, exp); |
| } else { /* Conntrack only */ |
| if (nf_ct_expect_related(exp) == 0) { |
| pr_debug("nf_ct_h323: expect T.120 "); |
| nf_ct_dump_tuple(&exp->tuple); |
| } else |
| ret = -1; |
| } |
| |
| nf_ct_expect_put(exp); |
| |
| return ret; |
| } |
| |
| /****************************************************************************/ |
| static int process_h245_channel(struct sk_buff *skb, |
| 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(skb, ct, ctinfo, data, dataoff, |
| &channel->mediaChannel); |
| if (ret < 0) |
| return -1; |
| } |
| |
| if (channel-> |
| options & eH2250LogicalChannelParameters_mediaControlChannel) { |
| /* RTCP */ |
| ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff, |
| &channel->mediaControlChannel); |
| if (ret < 0) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_olc(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, int dataoff, |
| OpenLogicalChannel *olc) |
| { |
| int ret; |
| |
| pr_debug("nf_ct_h323: OpenLogicalChannel\n"); |
| |
| if (olc->forwardLogicalChannelParameters.multiplexParameters.choice == |
| eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters) |
| { |
| ret = process_h245_channel(skb, 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(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &olc->separateStack.networkAddress. |
| localAreaAddress); |
| if (ret < 0) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_olca(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, int dataoff, |
| OpenLogicalChannelAck *olca) |
| { |
| H2250LogicalChannelAckParameters *ack; |
| int ret; |
| |
| pr_debug("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(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &ack->mediaChannel); |
| if (ret < 0) |
| return -1; |
| } |
| |
| if (ack->options & |
| eH2250LogicalChannelAckParameters_mediaControlChannel) { |
| /* RTCP */ |
| ret = expect_rtp_rtcp(skb, ct, ctinfo, data, dataoff, |
| &ack->mediaControlChannel); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| if ((olca->options & eOpenLogicalChannelAck_separateStack) && |
| olca->separateStack.networkAddress.choice == |
| eNetworkAccessParameters_networkAddress_localAreaAddress) { |
| ret = expect_t120(skb, ct, ctinfo, data, dataoff, |
| &olca->separateStack.networkAddress. |
| localAreaAddress); |
| if (ret < 0) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_h245(struct sk_buff *skb, 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(skb, ct, ctinfo, data, dataoff, |
| &mscm->request.openLogicalChannel); |
| } |
| pr_debug("nf_ct_h323: H.245 Request %d\n", |
| mscm->request.choice); |
| break; |
| case eMultimediaSystemControlMessage_response: |
| if (mscm->response.choice == |
| eResponseMessage_openLogicalChannelAck) { |
| return process_olca(skb, ct, ctinfo, data, dataoff, |
| &mscm->response. |
| openLogicalChannelAck); |
| } |
| pr_debug("nf_ct_h323: H.245 Response %d\n", |
| mscm->response.choice); |
| break; |
| default: |
| pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice); |
| break; |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int h245_help(struct sk_buff *skb, 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; |
| } |
| pr_debug("nf_ct_h245: skblen = %u\n", skb->len); |
| |
| spin_lock_bh(&nf_h323_lock); |
| |
| /* Process each TPKT */ |
| while (get_tpkt_data(skb, protoff, ct, ctinfo, |
| &data, &datalen, &dataoff)) { |
| pr_debug("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) { |
| pr_debug("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(skb, 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 const struct nf_conntrack_expect_policy h245_exp_policy = { |
| .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */, |
| .timeout = 240, |
| }; |
| |
| static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = { |
| .name = "H.245", |
| .me = THIS_MODULE, |
| .tuple.src.l3num = AF_UNSPEC, |
| .tuple.dst.protonum = IPPROTO_UDP, |
| .help = h245_help, |
| .expect_policy = &h245_exp_policy, |
| }; |
| |
| /****************************************************************************/ |
| int get_h225_addr(struct nf_conn *ct, unsigned char *data, |
| TransportAddress *taddr, |
| union nf_inet_addr *addr, __be16 *port) |
| { |
| const unsigned char *p; |
| int len; |
| |
| switch (taddr->choice) { |
| case eTransportAddress_ipAddress: |
| if (nf_ct_l3num(ct) != AF_INET) |
| return 0; |
| p = data + taddr->ipAddress.ip; |
| len = 4; |
| break; |
| case eTransportAddress_ip6Address: |
| if (nf_ct_l3num(ct) != AF_INET6) |
| return 0; |
| p = data + taddr->ip6Address.ip; |
| 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 *skb, 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_inet_addr 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_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &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(skb, ct, ctinfo, data, dataoff, taddr, |
| port, exp); |
| } else { /* Conntrack only */ |
| if (nf_ct_expect_related(exp) == 0) { |
| pr_debug("nf_ct_q931: expect H.245 "); |
| nf_ct_dump_tuple(&exp->tuple); |
| } else |
| ret = -1; |
| } |
| |
| nf_ct_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(const union nf_inet_addr *src, |
| const union nf_inet_addr *dst, |
| u_int8_t family) |
| { |
| const struct nf_afinfo *afinfo; |
| struct flowi fl1, fl2; |
| int ret = 0; |
| |
| /* rcu_read_lock()ed by nf_hook_slow() */ |
| afinfo = nf_get_afinfo(family); |
| if (!afinfo) |
| return 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 (!afinfo->route((struct dst_entry **)&rt1, &fl1)) { |
| if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) { |
| 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_NF_CONNTRACK_IPV6) || \ |
| defined(CONFIG_NF_CONNTRACK_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)); |
| if (!afinfo->route((struct dst_entry **)&rt1, &fl1)) { |
| if (!afinfo->route((struct dst_entry **)&rt2, &fl2)) { |
| 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 *skb, |
| 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_inet_addr 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, |
| nf_ct_l3num(ct))) { |
| pr_debug("nf_ct_q931: Call Forwarding not tracked\n"); |
| return 0; |
| } |
| |
| /* Create expect for the second call leg */ |
| if ((exp = nf_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &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(skb, ct, ctinfo, data, dataoff, |
| taddr, port, exp); |
| } else { /* Conntrack only */ |
| if (nf_ct_expect_related(exp) == 0) { |
| pr_debug("nf_ct_q931: expect Call Forwarding "); |
| nf_ct_dump_tuple(&exp->tuple); |
| } else |
| ret = -1; |
| } |
| |
| nf_ct_expect_put(exp); |
| |
| return ret; |
| } |
| |
| /****************************************************************************/ |
| static int process_setup(struct sk_buff *skb, 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_inet_addr addr; |
| typeof(set_h225_addr_hook) set_h225_addr; |
| |
| pr_debug("nf_ct_q931: Setup\n"); |
| |
| if (setup->options & eSetup_UUIE_h245Address) { |
| ret = expect_h245(skb, 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))) { |
| pr_debug("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(skb, 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))) { |
| pr_debug("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(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &setup->fastStart.item[i]); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_callproceeding(struct sk_buff *skb, |
| struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, int dataoff, |
| CallProceeding_UUIE *callproc) |
| { |
| int ret; |
| int i; |
| |
| pr_debug("nf_ct_q931: CallProceeding\n"); |
| |
| if (callproc->options & eCallProceeding_UUIE_h245Address) { |
| ret = expect_h245(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &callproc->fastStart.item[i]); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_connect(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, int dataoff, |
| Connect_UUIE *connect) |
| { |
| int ret; |
| int i; |
| |
| pr_debug("nf_ct_q931: Connect\n"); |
| |
| if (connect->options & eConnect_UUIE_h245Address) { |
| ret = expect_h245(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &connect->fastStart.item[i]); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_alerting(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, int dataoff, |
| Alerting_UUIE *alert) |
| { |
| int ret; |
| int i; |
| |
| pr_debug("nf_ct_q931: Alerting\n"); |
| |
| if (alert->options & eAlerting_UUIE_h245Address) { |
| ret = expect_h245(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &alert->fastStart.item[i]); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_facility(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, int dataoff, |
| Facility_UUIE *facility) |
| { |
| int ret; |
| int i; |
| |
| pr_debug("nf_ct_q931: Facility\n"); |
| |
| if (facility->reason.choice == eFacilityReason_callForwarded) { |
| if (facility->options & eFacility_UUIE_alternativeAddress) |
| return expect_callforwarding(skb, ct, ctinfo, data, |
| dataoff, |
| &facility-> |
| alternativeAddress); |
| return 0; |
| } |
| |
| if (facility->options & eFacility_UUIE_h245Address) { |
| ret = expect_h245(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &facility->fastStart.item[i]); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_progress(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, int dataoff, |
| Progress_UUIE *progress) |
| { |
| int ret; |
| int i; |
| |
| pr_debug("nf_ct_q931: Progress\n"); |
| |
| if (progress->options & eProgress_UUIE_h245Address) { |
| ret = expect_h245(skb, 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(skb, ct, ctinfo, data, dataoff, |
| &progress->fastStart.item[i]); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_q931(struct sk_buff *skb, 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(skb, ct, ctinfo, data, dataoff, |
| &pdu->h323_message_body.setup); |
| break; |
| case eH323_UU_PDU_h323_message_body_callProceeding: |
| ret = process_callproceeding(skb, ct, ctinfo, data, dataoff, |
| &pdu->h323_message_body. |
| callProceeding); |
| break; |
| case eH323_UU_PDU_h323_message_body_connect: |
| ret = process_connect(skb, ct, ctinfo, data, dataoff, |
| &pdu->h323_message_body.connect); |
| break; |
| case eH323_UU_PDU_h323_message_body_alerting: |
| ret = process_alerting(skb, ct, ctinfo, data, dataoff, |
| &pdu->h323_message_body.alerting); |
| break; |
| case eH323_UU_PDU_h323_message_body_facility: |
| ret = process_facility(skb, ct, ctinfo, data, dataoff, |
| &pdu->h323_message_body.facility); |
| break; |
| case eH323_UU_PDU_h323_message_body_progress: |
| ret = process_progress(skb, ct, ctinfo, data, dataoff, |
| &pdu->h323_message_body.progress); |
| break; |
| default: |
| pr_debug("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(skb, ct, ctinfo, data, dataoff, |
| &pdu->h245Control.item[i]); |
| if (ret < 0) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int q931_help(struct sk_buff *skb, 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; |
| } |
| pr_debug("nf_ct_q931: skblen = %u\n", skb->len); |
| |
| spin_lock_bh(&nf_h323_lock); |
| |
| /* Process each TPKT */ |
| while (get_tpkt_data(skb, protoff, ct, ctinfo, |
| &data, &datalen, &dataoff)) { |
| pr_debug("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) { |
| pr_debug("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(skb, 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 const struct nf_conntrack_expect_policy q931_exp_policy = { |
| /* T.120 and H.245 */ |
| .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4, |
| .timeout = 240, |
| }; |
| |
| static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = { |
| { |
| .name = "Q.931", |
| .me = THIS_MODULE, |
| .tuple.src.l3num = AF_INET, |
| .tuple.src.u.tcp.port = __constant_htons(Q931_PORT), |
| .tuple.dst.protonum = IPPROTO_TCP, |
| .help = q931_help, |
| .expect_policy = &q931_exp_policy, |
| }, |
| { |
| .name = "Q.931", |
| .me = THIS_MODULE, |
| .tuple.src.l3num = AF_INET6, |
| .tuple.src.u.tcp.port = __constant_htons(Q931_PORT), |
| .tuple.dst.protonum = IPPROTO_TCP, |
| .help = q931_help, |
| .expect_policy = &q931_exp_policy, |
| }, |
| }; |
| |
| /****************************************************************************/ |
| static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff, |
| int *datalen) |
| { |
| const struct udphdr *uh; |
| struct udphdr _uh; |
| int dataoff; |
| |
| uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh); |
| if (uh == NULL) |
| return NULL; |
| dataoff = protoff + sizeof(_uh); |
| if (dataoff >= skb->len) |
| return NULL; |
| *datalen = skb->len - dataoff; |
| return skb_header_pointer(skb, dataoff, *datalen, h323_buffer); |
| } |
| |
| /****************************************************************************/ |
| static struct nf_conntrack_expect *find_expect(struct nf_conn *ct, |
| union nf_inet_addr *addr, |
| __be16 port) |
| { |
| struct net *net = nf_ct_net(ct); |
| 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_ct_expect_find(net, &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 *skb, 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_inet_addr 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_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| 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(skb, ct, ctinfo, data, taddr, i, port, exp); |
| } else { /* Conntrack only */ |
| if (nf_ct_expect_related(exp) == 0) { |
| pr_debug("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_ct_expect_put(exp); |
| |
| return ret; |
| } |
| |
| /****************************************************************************/ |
| static int process_grq(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, GatekeeperRequest *grq) |
| { |
| typeof(set_ras_addr_hook) set_ras_addr; |
| |
| pr_debug("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(skb, ct, ctinfo, data, |
| &grq->rasAddress, 1); |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_gcf(struct sk_buff *skb, 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_inet_addr addr; |
| struct nf_conntrack_expect *exp; |
| |
| pr_debug("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_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &ct->tuplehash[!dir].tuple.src.u3, &addr, |
| IPPROTO_UDP, NULL, &port); |
| exp->helper = nf_conntrack_helper_ras; |
| |
| if (nf_ct_expect_related(exp) == 0) { |
| pr_debug("nf_ct_ras: expect RAS "); |
| nf_ct_dump_tuple(&exp->tuple); |
| } else |
| ret = -1; |
| |
| nf_ct_expect_put(exp); |
| |
| return ret; |
| } |
| |
| /****************************************************************************/ |
| static int process_rrq(struct sk_buff *skb, 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; |
| |
| pr_debug("nf_ct_ras: RRQ\n"); |
| |
| ret = expect_q931(skb, 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(skb, ct, ctinfo, data, |
| rrq->rasAddress.item, |
| rrq->rasAddress.count); |
| if (ret < 0) |
| return -1; |
| } |
| |
| if (rrq->options & eRegistrationRequest_timeToLive) { |
| pr_debug("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 *skb, 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; |
| |
| pr_debug("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(skb, ct, ctinfo, data, |
| rcf->callSignalAddress.item, |
| rcf->callSignalAddress.count); |
| if (ret < 0) |
| return -1; |
| } |
| |
| if (rcf->options & eRegistrationConfirm_timeToLive) { |
| pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive); |
| info->timeout = rcf->timeToLive; |
| } |
| |
| if (info->timeout > 0) { |
| pr_debug("nf_ct_ras: set RAS connection timeout to " |
| "%u seconds\n", info->timeout); |
| nf_ct_refresh(ct, skb, info->timeout * HZ); |
| |
| /* Set expect timeout */ |
| spin_lock_bh(&nf_conntrack_lock); |
| exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3, |
| info->sig_port[!dir]); |
| if (exp) { |
| pr_debug("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); |
| } |
| spin_unlock_bh(&nf_conntrack_lock); |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_urq(struct sk_buff *skb, 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; |
| |
| pr_debug("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(skb, 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, skb, 30 * HZ); |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_arq(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, AdmissionRequest *arq) |
| { |
| const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info; |
| int dir = CTINFO2DIR(ctinfo); |
| __be16 port; |
| union nf_inet_addr addr; |
| typeof(set_h225_addr_hook) set_h225_addr; |
| |
| pr_debug("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(skb, 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(skb, data, 0, |
| &arq->srcCallSignalAddress, |
| &ct->tuplehash[!dir].tuple.dst.u3, |
| port); |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_acf(struct sk_buff *skb, 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_inet_addr addr; |
| struct nf_conntrack_expect *exp; |
| typeof(set_sig_addr_hook) set_sig_addr; |
| |
| pr_debug("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(skb, ct, ctinfo, data, |
| &acf->destCallSignalAddress, 1); |
| return 0; |
| } |
| |
| /* Need new expect */ |
| if ((exp = nf_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &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_ct_expect_related(exp) == 0) { |
| pr_debug("nf_ct_ras: expect Q.931 "); |
| nf_ct_dump_tuple(&exp->tuple); |
| } else |
| ret = -1; |
| |
| nf_ct_expect_put(exp); |
| |
| return ret; |
| } |
| |
| /****************************************************************************/ |
| static int process_lrq(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, LocationRequest *lrq) |
| { |
| typeof(set_ras_addr_hook) set_ras_addr; |
| |
| pr_debug("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(skb, ct, ctinfo, data, |
| &lrq->replyAddress, 1); |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_lcf(struct sk_buff *skb, 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_inet_addr addr; |
| struct nf_conntrack_expect *exp; |
| |
| pr_debug("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_ct_expect_alloc(ct)) == NULL) |
| return -1; |
| nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct), |
| &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_ct_expect_related(exp) == 0) { |
| pr_debug("nf_ct_ras: expect Q.931 "); |
| nf_ct_dump_tuple(&exp->tuple); |
| } else |
| ret = -1; |
| |
| nf_ct_expect_put(exp); |
| |
| /* Ignore rasAddress */ |
| |
| return ret; |
| } |
| |
| /****************************************************************************/ |
| static int process_irr(struct sk_buff *skb, 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; |
| |
| pr_debug("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(skb, 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(skb, ct, ctinfo, data, |
| irr->callSignalAddress.item, |
| irr->callSignalAddress.count); |
| if (ret < 0) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int process_ras(struct sk_buff *skb, struct nf_conn *ct, |
| enum ip_conntrack_info ctinfo, |
| unsigned char **data, RasMessage *ras) |
| { |
| switch (ras->choice) { |
| case eRasMessage_gatekeeperRequest: |
| return process_grq(skb, ct, ctinfo, data, |
| &ras->gatekeeperRequest); |
| case eRasMessage_gatekeeperConfirm: |
| return process_gcf(skb, ct, ctinfo, data, |
| &ras->gatekeeperConfirm); |
| case eRasMessage_registrationRequest: |
| return process_rrq(skb, ct, ctinfo, data, |
| &ras->registrationRequest); |
| case eRasMessage_registrationConfirm: |
| return process_rcf(skb, ct, ctinfo, data, |
| &ras->registrationConfirm); |
| case eRasMessage_unregistrationRequest: |
| return process_urq(skb, ct, ctinfo, data, |
| &ras->unregistrationRequest); |
| case eRasMessage_admissionRequest: |
| return process_arq(skb, ct, ctinfo, data, |
| &ras->admissionRequest); |
| case eRasMessage_admissionConfirm: |
| return process_acf(skb, ct, ctinfo, data, |
| &ras->admissionConfirm); |
| case eRasMessage_locationRequest: |
| return process_lrq(skb, ct, ctinfo, data, |
| &ras->locationRequest); |
| case eRasMessage_locationConfirm: |
| return process_lcf(skb, ct, ctinfo, data, |
| &ras->locationConfirm); |
| case eRasMessage_infoRequestResponse: |
| return process_irr(skb, ct, ctinfo, data, |
| &ras->infoRequestResponse); |
| default: |
| pr_debug("nf_ct_ras: RAS message %d\n", ras->choice); |
| break; |
| } |
| |
| return 0; |
| } |
| |
| /****************************************************************************/ |
| static int ras_help(struct sk_buff *skb, unsigned int protoff, |
| struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
| { |
| static RasMessage ras; |
| unsigned char *data; |
| int datalen = 0; |
| int ret; |
| |
| pr_debug("nf_ct_ras: skblen = %u\n", skb->len); |
| |
| spin_lock_bh(&nf_h323_lock); |
| |
| /* Get UDP data */ |
| data = get_udp_data(skb, protoff, &datalen); |
| if (data == NULL) |
| goto accept; |
| pr_debug("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) { |
| pr_debug("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(skb, 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 const struct nf_conntrack_expect_policy ras_exp_policy = { |
| .max_expected = 32, |
| .timeout = 240, |
| }; |
| |
| static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = { |
| { |
| .name = "RAS", |
| .me = THIS_MODULE, |
| .tuple.src.l3num = AF_INET, |
| .tuple.src.u.udp.port = __constant_htons(RAS_PORT), |
| .tuple.dst.protonum = IPPROTO_UDP, |
| .help = ras_help, |
| .expect_policy = &ras_exp_policy, |
| }, |
| { |
| .name = "RAS", |
| .me = THIS_MODULE, |
| .tuple.src.l3num = AF_INET6, |
| .tuple.src.u.udp.port = __constant_htons(RAS_PORT), |
| .tuple.dst.protonum = IPPROTO_UDP, |
| .help = ras_help, |
| .expect_policy = &ras_exp_policy, |
| }, |
| }; |
| |
| /****************************************************************************/ |
| 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]); |
| nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); |
| kfree(h323_buffer); |
| pr_debug("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_h245); |
| if (ret < 0) |
| goto err1; |
| ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]); |
| if (ret < 0) |
| goto err2; |
| ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]); |
| if (ret < 0) |
| goto err3; |
| ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]); |
| if (ret < 0) |
| goto err4; |
| ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]); |
| if (ret < 0) |
| goto err5; |
| pr_debug("nf_ct_h323: init success\n"); |
| return 0; |
| |
| err5: |
| nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]); |
| err4: |
| nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]); |
| err3: |
| nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]); |
| err2: |
| nf_conntrack_helper_unregister(&nf_conntrack_helper_h245); |
| err1: |
| kfree(h323_buffer); |
| 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 <zhaojingmin@users.sourceforge.net>"); |
| MODULE_DESCRIPTION("H.323 connection tracking helper"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("ip_conntrack_h323"); |