diff options
Diffstat (limited to 'net/ipv4/netfilter/ip_conntrack_helper_h323.c')
| -rw-r--r-- | net/ipv4/netfilter/ip_conntrack_helper_h323.c | 1731 |
1 files changed, 1731 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ip_conntrack_helper_h323.c b/net/ipv4/netfilter/ip_conntrack_helper_h323.c new file mode 100644 index 00000000000000..20da6730b86056 --- /dev/null +++ b/net/ipv4/netfilter/ip_conntrack_helper_h323.c @@ -0,0 +1,1731 @@ +/* + * 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/ + * + * Changes: + * 2006-02-01 - initial version 0.1 + * + * 2006-02-20 - version 0.2 + * 1. Changed source format to follow kernel conventions + * 2. Deleted some unnecessary structures + * 3. Minor fixes + * + * 2006-03-10 - version 0.3 + * 1. Added support for multiple TPKTs in one packet (suggested by + * Patrick McHardy) + * 2. Avoid excessive stack usage (based on Patrick McHardy's patch) + * 3. Added support for non-linear skb (based on Patrick McHardy's patch) + * 4. Fixed missing H.245 module owner (Patrick McHardy) + * 5. Avoid long RAS expectation chains (Patrick McHardy) + * 6. Fixed incorrect __exit attribute (Patrick McHardy) + * 7. Eliminated unnecessary return code + * 8. Fixed incorrect use of NAT data from conntrack code (suggested by + * Patrick McHardy) + * 9. Fixed TTL calculation error in RCF + * 10. Added TTL support in RRQ + * 11. Better support for separate TPKT header and data + * + * 2006-03-15 - version 0.4 + * 1. Added support for T.120 channels + * 2. Added parameter gkrouted_only (suggested by Patrick McHardy) + * 3. Splitted ASN.1 code and data (suggested by Patrick McHardy) + * 4. Sort ASN.1 data to avoid forwarding declarations (suggested by + * Patrick McHardy) + * 5. Reset next TPKT data length in get_tpkt_data() + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/netfilter.h> +#include <linux/ip.h> +#include <net/tcp.h> +#include <linux/netfilter_ipv4/ip_conntrack.h> +#include <linux/netfilter_ipv4/ip_conntrack_core.h> +#include <linux/netfilter_ipv4/ip_conntrack_helper.h> +#include <linux/netfilter_ipv4/ip_conntrack_tuple.h> +#include <linux/netfilter_ipv4/ip_conntrack_h323.h> +#include <linux/moduleparam.h> + +#include "ip_conntrack_helper_h323_asn1.h" + +#if 0 +#define DEBUGP printk +#else +#define DEBUGP(format, args...) +#endif + +/* Parameters */ +static int gkrouted_only = 1; +module_param(gkrouted_only, int, 0600); +MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper"); + +/* Hooks for NAT */ +int (*set_h245_addr_hook) (struct sk_buff ** pskb, + unsigned char **data, int dataoff, + H245_TransportAddress * addr, + u_int32_t ip, u_int16_t port); +int (*set_h225_addr_hook) (struct sk_buff ** pskb, + unsigned char **data, int dataoff, + TransportAddress * addr, + u_int32_t ip, u_int16_t port); +int (*set_sig_addr_hook) (struct sk_buff ** pskb, + struct ip_conntrack * ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, + TransportAddress * addr, int count); +int (*set_ras_addr_hook) (struct sk_buff ** pskb, + struct ip_conntrack * ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, + TransportAddress * addr, int count); +int (*nat_rtp_rtcp_hook) (struct sk_buff ** pskb, + struct ip_conntrack * ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + H245_TransportAddress * addr, + u_int16_t port, u_int16_t rtp_port, + struct ip_conntrack_expect * rtp_exp, + struct ip_conntrack_expect * rtcp_exp); +int (*nat_t120_hook) (struct sk_buff ** pskb, + struct ip_conntrack * ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + H245_TransportAddress * addr, u_int16_t port, + struct ip_conntrack_expect * exp); +int (*nat_h245_hook) (struct sk_buff ** pskb, + struct ip_conntrack * ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + TransportAddress * addr, u_int16_t port, + struct ip_conntrack_expect * exp); +int (*nat_q931_hook) (struct sk_buff ** pskb, + struct ip_conntrack * ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, TransportAddress * addr, int idx, + u_int16_t port, struct ip_conntrack_expect * exp); + + +static DEFINE_SPINLOCK(ip_h323_lock); +static char *h323_buffer; + +/****************************************************************************/ +static int get_tpkt_data(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int *datalen, int *dataoff) +{ + struct ip_ct_h323_master *info = &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, (*pskb)->nh.iph->ihl * 4, + sizeof(_tcph), &_tcph); + if (th == NULL) + return 0; + + /* Get TCP data offset */ + tcpdataoff = (*pskb)->nh.iph->ihl * 4 + 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("ip_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("ip_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 > tcpdatalen) { + if (tcpdatalen == 4) { /* Separate TPKT header */ + /* Netmeeting sends TPKT header and data separately */ + DEBUGP("ip_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("ip_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; +} + +/****************************************************************************/ +int get_h245_addr(unsigned char *data, H245_TransportAddress * addr, + u_int32_t * ip, u_int16_t * port) +{ + unsigned char *p; + + if (addr->choice != eH245_TransportAddress_unicastAddress || + addr->unicastAddress.choice != eUnicastAddress_iPAddress) + return 0; + + p = data + addr->unicastAddress.iPAddress.network; + *ip = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | (p[3])); + *port = (p[4] << 8) | (p[5]); + + return 1; +} + +/****************************************************************************/ +static int expect_rtp_rtcp(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + H245_TransportAddress * addr) +{ + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + u_int32_t ip; + u_int16_t port; + u_int16_t rtp_port; + struct ip_conntrack_expect *rtp_exp; + struct ip_conntrack_expect *rtcp_exp; + + /* Read RTP or RTCP address */ + if (!get_h245_addr(*data, addr, &ip, &port) || + ip != ct->tuplehash[dir].tuple.src.ip || port == 0) + return 0; + + /* RTP port is even */ + rtp_port = port & (~1); + + /* Create expect for RTP */ + if ((rtp_exp = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + rtp_exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + rtp_exp->tuple.src.u.udp.port = 0; + rtp_exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip; + rtp_exp->tuple.dst.u.udp.port = htons(rtp_port); + rtp_exp->tuple.dst.protonum = IPPROTO_UDP; + rtp_exp->mask.src.ip = 0xFFFFFFFF; + rtp_exp->mask.src.u.udp.port = 0; + rtp_exp->mask.dst.ip = 0xFFFFFFFF; + rtp_exp->mask.dst.u.udp.port = 0xFFFF; + rtp_exp->mask.dst.protonum = 0xFF; + rtp_exp->flags = 0; + + /* Create expect for RTCP */ + if ((rtcp_exp = ip_conntrack_expect_alloc(ct)) == NULL) { + ip_conntrack_expect_put(rtp_exp); + return -1; + } + rtcp_exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + rtcp_exp->tuple.src.u.udp.port = 0; + rtcp_exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip; + rtcp_exp->tuple.dst.u.udp.port = htons(rtp_port + 1); + rtcp_exp->tuple.dst.protonum = IPPROTO_UDP; + rtcp_exp->mask.src.ip = 0xFFFFFFFF; + rtcp_exp->mask.src.u.udp.port = 0; + rtcp_exp->mask.dst.ip = 0xFFFFFFFF; + rtcp_exp->mask.dst.u.udp.port = 0xFFFF; + rtcp_exp->mask.dst.protonum = 0xFF; + rtcp_exp->flags = 0; + + if (ct->tuplehash[dir].tuple.src.ip != + ct->tuplehash[!dir].tuple.dst.ip && nat_rtp_rtcp_hook) { + /* NAT needed */ + ret = nat_rtp_rtcp_hook(pskb, ct, ctinfo, data, dataoff, + addr, port, rtp_port, rtp_exp, + rtcp_exp); + } else { /* Conntrack only */ + rtp_exp->expectfn = NULL; + rtcp_exp->expectfn = NULL; + + if (ip_conntrack_expect_related(rtp_exp) == 0) { + if (ip_conntrack_expect_related(rtcp_exp) == 0) { + DEBUGP("ip_ct_h323: expect RTP " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(rtp_exp->tuple.src.ip), + ntohs(rtp_exp->tuple.src.u.udp.port), + NIPQUAD(rtp_exp->tuple.dst.ip), + ntohs(rtp_exp->tuple.dst.u.udp.port)); + DEBUGP("ip_ct_h323: expect RTCP " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(rtcp_exp->tuple.src.ip), + ntohs(rtcp_exp->tuple.src.u.udp.port), + NIPQUAD(rtcp_exp->tuple.dst.ip), + ntohs(rtcp_exp->tuple.dst.u.udp.port)); + } else { + ip_conntrack_unexpect_related(rtp_exp); + ret = -1; + } + } else + ret = -1; + } + + ip_conntrack_expect_put(rtp_exp); + ip_conntrack_expect_put(rtcp_exp); + + return ret; +} + +/****************************************************************************/ +static int expect_t120(struct sk_buff **pskb, + struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + H245_TransportAddress * addr) +{ + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + u_int32_t ip; + u_int16_t port; + struct ip_conntrack_expect *exp = NULL; + + /* Read T.120 address */ + if (!get_h245_addr(*data, addr, &ip, &port) || + ip != ct->tuplehash[dir].tuple.src.ip || port == 0) + return 0; + + /* Create expect for T.120 connections */ + if ((exp = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + exp->tuple.src.u.tcp.port = 0; + exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip; + exp->tuple.dst.u.tcp.port = htons(port); + exp->tuple.dst.protonum = IPPROTO_TCP; + exp->mask.src.ip = 0xFFFFFFFF; + exp->mask.src.u.tcp.port = 0; + exp->mask.dst.ip = 0xFFFFFFFF; + exp->mask.dst.u.tcp.port = 0xFFFF; + exp->mask.dst.protonum = 0xFF; + exp->flags = IP_CT_EXPECT_PERMANENT; /* Accept multiple channels */ + + if (ct->tuplehash[dir].tuple.src.ip != + ct->tuplehash[!dir].tuple.dst.ip && nat_t120_hook) { + /* NAT needed */ + ret = nat_t120_hook(pskb, ct, ctinfo, data, dataoff, addr, + port, exp); + } else { /* Conntrack only */ + exp->expectfn = NULL; + if (ip_conntrack_expect_related(exp) == 0) { + DEBUGP("ip_ct_h323: expect T.120 " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port)); + } else + ret = -1; + } + + ip_conntrack_expect_put(exp); + + return ret; +} + +/****************************************************************************/ +static int process_h245_channel(struct sk_buff **pskb, + struct ip_conntrack *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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + OpenLogicalChannel * olc) +{ + int ret; + + DEBUGP("ip_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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + OpenLogicalChannelAck * olca) +{ + H2250LogicalChannelAckParameters *ack; + int ret; + + DEBUGP("ip_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 ip_conntrack *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("ip_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("ip_ct_h323: H.245 Response %d\n", + mscm->response.choice); + break; + default: + DEBUGP("ip_ct_h323: H.245 signal %d\n", mscm->choice); + break; + } + + return 0; +} + +/****************************************************************************/ +static int h245_help(struct sk_buff **pskb, struct ip_conntrack *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("ip_ct_h245: skblen = %u\n", (*pskb)->len); + + spin_lock_bh(&ip_h323_lock); + + /* Process each TPKT */ + while (get_tpkt_data(pskb, ct, ctinfo, &data, &datalen, &dataoff)) { + DEBUGP("ip_ct_h245: TPKT %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n", + NIPQUAD((*pskb)->nh.iph->saddr), + NIPQUAD((*pskb)->nh.iph->daddr), datalen); + + /* Decode H.245 signal */ + ret = DecodeMultimediaSystemControlMessage(data, datalen, + &mscm); + if (ret < 0) { + if (net_ratelimit()) + printk("ip_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(&ip_h323_lock); + return NF_ACCEPT; + + drop: + spin_unlock_bh(&ip_h323_lock); + if (net_ratelimit()) + printk("ip_ct_h245: packet dropped\n"); + return NF_DROP; +} + +/****************************************************************************/ +static struct ip_conntrack_helper ip_conntrack_helper_h245 = { + .name = "H.245", + .me = THIS_MODULE, + .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */ , + .timeout = 240, + .tuple = {.dst = {.protonum = IPPROTO_TCP}}, + .mask = {.src = {.u = {0xFFFF}}, + .dst = {.protonum = 0xFF}}, + .help = h245_help +}; + +/****************************************************************************/ +void ip_conntrack_h245_expect(struct ip_conntrack *new, + struct ip_conntrack_expect *this) +{ + write_lock_bh(&ip_conntrack_lock); + new->helper = &ip_conntrack_helper_h245; + write_unlock_bh(&ip_conntrack_lock); +} + +/****************************************************************************/ +static int get_h225_addr(unsigned char *data, TransportAddress * addr, + u_int32_t * ip, u_int16_t * port) +{ + unsigned char *p; + + if (addr->choice != eTransportAddress_ipAddress) + return 0; + + p = data + addr->ipAddress.ip; + *ip = htonl((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | (p[3])); + *port = (p[4] << 8) | (p[5]); + + return 1; +} + +/****************************************************************************/ +static int expect_h245(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + TransportAddress * addr) +{ + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + u_int32_t ip; + u_int16_t port; + struct ip_conntrack_expect *exp = NULL; + + /* Read h245Address */ + if (!get_h225_addr(*data, addr, &ip, &port) || + ip != ct->tuplehash[dir].tuple.src.ip || port == 0) + return 0; + + /* Create expect for h245 connection */ + if ((exp = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + exp->tuple.src.u.tcp.port = 0; + exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip; + exp->tuple.dst.u.tcp.port = htons(port); + exp->tuple.dst.protonum = IPPROTO_TCP; + exp->mask.src.ip = 0xFFFFFFFF; + exp->mask.src.u.tcp.port = 0; + exp->mask.dst.ip = 0xFFFFFFFF; + exp->mask.dst.u.tcp.port = 0xFFFF; + exp->mask.dst.protonum = 0xFF; + exp->flags = 0; + + if (ct->tuplehash[dir].tuple.src.ip != + ct->tuplehash[!dir].tuple.dst.ip && nat_h245_hook) { + /* NAT needed */ + ret = nat_h245_hook(pskb, ct, ctinfo, data, dataoff, addr, + port, exp); + } else { /* Conntrack only */ + exp->expectfn = ip_conntrack_h245_expect; + + if (ip_conntrack_expect_related(exp) == 0) { + DEBUGP("ip_ct_q931: expect H.245 " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port)); + } else + ret = -1; + } + + ip_conntrack_expect_put(exp); + + return ret; +} + +/****************************************************************************/ +static int process_setup(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + Setup_UUIE * setup) +{ + int dir = CTINFO2DIR(ctinfo); + int ret; + int i; + u_int32_t ip; + u_int16_t port; + + DEBUGP("ip_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; + } + + if ((setup->options & eSetup_UUIE_destCallSignalAddress) && + (set_h225_addr_hook) && + get_h225_addr(*data, &setup->destCallSignalAddress, &ip, &port) && + ip != ct->tuplehash[!dir].tuple.src.ip) { + DEBUGP("ip_ct_q931: set destCallSignalAddress " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(ip), port, + NIPQUAD(ct->tuplehash[!dir].tuple.src.ip), + ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port)); + ret = set_h225_addr_hook(pskb, data, dataoff, + &setup->destCallSignalAddress, + ct->tuplehash[!dir].tuple.src.ip, + ntohs(ct->tuplehash[!dir].tuple.src. + u.tcp.port)); + if (ret < 0) + return -1; + } + + if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) && + (set_h225_addr_hook) && + get_h225_addr(*data, &setup->sourceCallSignalAddress, &ip, &port) + && ip != ct->tuplehash[!dir].tuple.dst.ip) { + DEBUGP("ip_ct_q931: set sourceCallSignalAddress " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(ip), port, + NIPQUAD(ct->tuplehash[!dir].tuple.dst.ip), + ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port)); + ret = set_h225_addr_hook(pskb, data, dataoff, + &setup->sourceCallSignalAddress, + ct->tuplehash[!dir].tuple.dst.ip, + ntohs(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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + CallProceeding_UUIE * callproc) +{ + int ret; + int i; + + DEBUGP("ip_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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + Connect_UUIE * connect) +{ + int ret; + int i; + + DEBUGP("ip_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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + Alerting_UUIE * alert) +{ + int ret; + int i; + + DEBUGP("ip_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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + Information_UUIE * info) +{ + int ret; + int i; + + DEBUGP("ip_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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + Facility_UUIE * facility) +{ + int ret; + int i; + + DEBUGP("ip_ct_q931: Facility\n"); + + 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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + Progress_UUIE * progress) +{ + int ret; + int i; + + DEBUGP("ip_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 ip_conntrack *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("ip_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, struct ip_conntrack *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("ip_ct_q931: skblen = %u\n", (*pskb)->len); + + spin_lock_bh(&ip_h323_lock); + + /* Process each TPKT */ + while (get_tpkt_data(pskb, ct, ctinfo, &data, &datalen, &dataoff)) { + DEBUGP("ip_ct_q931: TPKT %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n", + NIPQUAD((*pskb)->nh.iph->saddr), + NIPQUAD((*pskb)->nh.iph->daddr), datalen); + + /* Decode Q.931 signal */ + ret = DecodeQ931(data, datalen, &q931); + if (ret < 0) { + if (net_ratelimit()) + printk("ip_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(&ip_h323_lock); + return NF_ACCEPT; + + drop: + spin_unlock_bh(&ip_h323_lock); + if (net_ratelimit()) + printk("ip_ct_q931: packet dropped\n"); + return NF_DROP; +} + +/****************************************************************************/ +static struct ip_conntrack_helper ip_conntrack_helper_q931 = { + .name = "Q.931", + .me = THIS_MODULE, + .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4 /* T.120 and H.245 */ , + .timeout = 240, + .tuple = {.src = {.u = {__constant_htons(Q931_PORT)}}, + .dst = {.protonum = IPPROTO_TCP}}, + .mask = {.src = {.u = {0xFFFF}}, + .dst = {.protonum = 0xFF}}, + .help = q931_help +}; + +/****************************************************************************/ +void ip_conntrack_q931_expect(struct ip_conntrack *new, + struct ip_conntrack_expect *this) +{ + write_lock_bh(&ip_conntrack_lock); + new->helper = &ip_conntrack_helper_q931; + write_unlock_bh(&ip_conntrack_lock); +} + +/****************************************************************************/ +static unsigned char *get_udp_data(struct sk_buff **pskb, int *datalen) +{ + struct udphdr _uh, *uh; + int dataoff; + + uh = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4, sizeof(_uh), + &_uh); + if (uh == NULL) + return NULL; + dataoff = (*pskb)->nh.iph->ihl * 4 + sizeof(_uh); + if (dataoff >= (*pskb)->len) + return NULL; + *datalen = (*pskb)->len - dataoff; + return skb_header_pointer(*pskb, dataoff, *datalen, h323_buffer); +} + +/****************************************************************************/ +static struct ip_conntrack_expect *find_expect(struct ip_conntrack *ct, + u_int32_t ip, u_int16_t port) +{ + struct ip_conntrack_expect *exp; + struct ip_conntrack_tuple tuple; + + tuple.src.ip = 0; + tuple.src.u.tcp.port = 0; + tuple.dst.ip = ip; + tuple.dst.u.tcp.port = htons(port); + tuple.dst.protonum = IPPROTO_TCP; + + exp = __ip_conntrack_expect_find(&tuple); + if (exp->master == ct) + return exp; + return NULL; +} + +/****************************************************************************/ +static int set_expect_timeout(struct ip_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 ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, + TransportAddress * addr, int count) +{ + struct ip_ct_h323_master *info = &ct->help.ct_h323_info; + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + int i; + u_int32_t ip; + u_int16_t port; + struct ip_conntrack_expect *exp; + + /* Look for the first related address */ + for (i = 0; i < count; i++) { + if (get_h225_addr(*data, &addr[i], &ip, &port) && + ip == ct->tuplehash[dir].tuple.src.ip && port != 0) + break; + } + + if (i >= count) /* Not found */ + return 0; + + /* Create expect for Q.931 */ + if ((exp = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + exp->tuple.src.ip = gkrouted_only ? /* only accept calls from GK? */ + ct->tuplehash[!dir].tuple.src.ip : 0; + exp->tuple.src.u.tcp.port = 0; + exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip; + exp->tuple.dst.u.tcp.port = htons(port); + exp->tuple.dst.protonum = IPPROTO_TCP; + exp->mask.src.ip = gkrouted_only ? 0xFFFFFFFF : 0; + exp->mask.src.u.tcp.port = 0; + exp->mask.dst.ip = 0xFFFFFFFF; + exp->mask.dst.u.tcp.port = 0xFFFF; + exp->mask.dst.protonum = 0xFF; + exp->flags = IP_CT_EXPECT_PERMANENT; /* Accept multiple calls */ + + if (nat_q931_hook) { /* Need NAT */ + ret = nat_q931_hook(pskb, ct, ctinfo, data, addr, i, + port, exp); + } else { /* Conntrack only */ + exp->expectfn = ip_conntrack_q931_expect; + + if (ip_conntrack_expect_related(exp) == 0) { + DEBUGP("ip_ct_ras: expect Q.931 " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port)); + + /* Save port for looking up expect in processing RCF */ + info->sig_port[dir] = port; + } else + ret = -1; + } + + ip_conntrack_expect_put(exp); + + return ret; +} + +/****************************************************************************/ +static int process_grq(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, GatekeeperRequest * grq) +{ + DEBUGP("ip_ct_ras: GRQ\n"); + + if (set_ras_addr_hook) /* NATed */ + return set_ras_addr_hook(pskb, ct, ctinfo, data, + &grq->rasAddress, 1); + return 0; +} + +/* Declare before using */ +static void ip_conntrack_ras_expect(struct ip_conntrack *new, + struct ip_conntrack_expect *this); + +/****************************************************************************/ +static int process_gcf(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, GatekeeperConfirm * gcf) +{ + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + u_int32_t ip; + u_int16_t port; + struct ip_conntrack_expect *exp; + + DEBUGP("ip_ct_ras: GCF\n"); + + if (!get_h225_addr(*data, &gcf->rasAddress, &ip, &port)) + return 0; + + /* Registration port is the same as discovery port */ + if (ip == ct->tuplehash[dir].tuple.src.ip && + port == ntohs(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 = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + exp->tuple.src.u.tcp.port = 0; + exp->tuple.dst.ip = ip; + exp->tuple.dst.u.tcp.port = htons(port); + exp->tuple.dst.protonum = IPPROTO_UDP; + exp->mask.src.ip = 0xFFFFFFFF; + exp->mask.src.u.tcp.port = 0; + exp->mask.dst.ip = 0xFFFFFFFF; + exp->mask.dst.u.tcp.port = 0xFFFF; + exp->mask.dst.protonum = 0xFF; + exp->flags = 0; + exp->expectfn = ip_conntrack_ras_expect; + if (ip_conntrack_expect_related(exp) == 0) { + DEBUGP("ip_ct_ras: expect RAS " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port)); + } else + ret = -1; + + ip_conntrack_expect_put(exp); + + return ret; +} + +/****************************************************************************/ +static int process_rrq(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, RegistrationRequest * rrq) +{ + struct ip_ct_h323_master *info = &ct->help.ct_h323_info; + int ret; + + DEBUGP("ip_ct_ras: RRQ\n"); + + ret = expect_q931(pskb, ct, ctinfo, data, + rrq->callSignalAddress.item, + rrq->callSignalAddress.count); + if (ret < 0) + return -1; + + if (set_ras_addr_hook) { + ret = set_ras_addr_hook(pskb, ct, ctinfo, data, + rrq->rasAddress.item, + rrq->rasAddress.count); + if (ret < 0) + return -1; + } + + if (rrq->options & eRegistrationRequest_timeToLive) { + DEBUGP("ip_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive); + info->timeout = rrq->timeToLive; + } else + info->timeout = 0; + + return 0; +} + +/****************************************************************************/ +static int process_rcf(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, RegistrationConfirm * rcf) +{ + struct ip_ct_h323_master *info = &ct->help.ct_h323_info; + int dir = CTINFO2DIR(ctinfo); + int ret; + struct ip_conntrack_expect *exp; + + DEBUGP("ip_ct_ras: RCF\n"); + + if (set_sig_addr_hook) { + ret = set_sig_addr_hook(pskb, ct, ctinfo, data, + rcf->callSignalAddress.item, + rcf->callSignalAddress.count); + if (ret < 0) + return -1; + } + + if (rcf->options & eRegistrationConfirm_timeToLive) { + DEBUGP("ip_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive); + info->timeout = rcf->timeToLive; + } + + if (info->timeout > 0) { + DEBUGP + ("ip_ct_ras: set RAS connection timeout to %u seconds\n", + info->timeout); + ip_ct_refresh_acct(ct, ctinfo, NULL, info->timeout * HZ); + + /* Set expect timeout */ + read_lock_bh(&ip_conntrack_lock); + exp = find_expect(ct, ct->tuplehash[dir].tuple.dst.ip, + info->sig_port[!dir]); + if (exp) { + DEBUGP("ip_ct_ras: set Q.931 expect " + "(%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu) " + "timeout to %u seconds\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port), + info->timeout); + set_expect_timeout(exp, info->timeout); + } + read_unlock_bh(&ip_conntrack_lock); + } + + return 0; +} + +/****************************************************************************/ +static int process_urq(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, UnregistrationRequest * urq) +{ + struct ip_ct_h323_master *info = &ct->help.ct_h323_info; + int dir = CTINFO2DIR(ctinfo); + int ret; + + DEBUGP("ip_ct_ras: URQ\n"); + + if (set_sig_addr_hook) { + ret = set_sig_addr_hook(pskb, ct, ctinfo, data, + urq->callSignalAddress.item, + urq->callSignalAddress.count); + if (ret < 0) + return -1; + } + + /* Clear old expect */ + ip_ct_remove_expectations(ct); + info->sig_port[dir] = 0; + info->sig_port[!dir] = 0; + + /* Give it 30 seconds for UCF or URJ */ + ip_ct_refresh_acct(ct, ctinfo, NULL, 30 * HZ); + + return 0; +} + +/****************************************************************************/ +static int process_arq(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, AdmissionRequest * arq) +{ + struct ip_ct_h323_master *info = &ct->help.ct_h323_info; + int dir = CTINFO2DIR(ctinfo); + u_int32_t ip; + u_int16_t port; + + DEBUGP("ip_ct_ras: ARQ\n"); + + if ((arq->options & eAdmissionRequest_destCallSignalAddress) && + get_h225_addr(*data, &arq->destCallSignalAddress, &ip, &port) && + ip == ct->tuplehash[dir].tuple.src.ip && + port == info->sig_port[dir] && set_h225_addr_hook) { + /* Answering ARQ */ + return set_h225_addr_hook(pskb, data, 0, + &arq->destCallSignalAddress, + ct->tuplehash[!dir].tuple.dst.ip, + info->sig_port[!dir]); + } + + if ((arq->options & eAdmissionRequest_srcCallSignalAddress) && + get_h225_addr(*data, &arq->srcCallSignalAddress, &ip, &port) && + ip == ct->tuplehash[dir].tuple.src.ip && set_h225_addr_hook) { + /* Calling ARQ */ + return set_h225_addr_hook(pskb, data, 0, + &arq->srcCallSignalAddress, + ct->tuplehash[!dir].tuple.dst.ip, + port); + } + + return 0; +} + +/****************************************************************************/ +static int process_acf(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, AdmissionConfirm * acf) +{ + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + u_int32_t ip; + u_int16_t port; + struct ip_conntrack_expect *exp; + + DEBUGP("ip_ct_ras: ACF\n"); + + if (!get_h225_addr(*data, &acf->destCallSignalAddress, &ip, &port)) + return 0; + + if (ip == ct->tuplehash[dir].tuple.dst.ip) { /* Answering ACF */ + if (set_sig_addr_hook) + return set_sig_addr_hook(pskb, ct, ctinfo, data, + &acf->destCallSignalAddress, + 1); + return 0; + } + + /* Need new expect */ + if ((exp = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + exp->tuple.src.u.tcp.port = 0; + exp->tuple.dst.ip = ip; + exp->tuple.dst.u.tcp.port = htons(port); + exp->tuple.dst.protonum = IPPROTO_TCP; + exp->mask.src.ip = 0xFFFFFFFF; + exp->mask.src.u.tcp.port = 0; + exp->mask.dst.ip = 0xFFFFFFFF; + exp->mask.dst.u.tcp.port = 0xFFFF; + exp->mask.dst.protonum = 0xFF; + exp->flags = IP_CT_EXPECT_PERMANENT; + exp->expectfn = ip_conntrack_q931_expect; + + if (ip_conntrack_expect_related(exp) == 0) { + DEBUGP("ip_ct_ras: expect Q.931 " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port)); + } else + ret = -1; + + ip_conntrack_expect_put(exp); + + return ret; +} + +/****************************************************************************/ +static int process_lrq(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, LocationRequest * lrq) +{ + DEBUGP("ip_ct_ras: LRQ\n"); + + if (set_ras_addr_hook) + return set_ras_addr_hook(pskb, ct, ctinfo, data, + &lrq->replyAddress, 1); + return 0; +} + +/****************************************************************************/ +static int process_lcf(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, LocationConfirm * lcf) +{ + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + u_int32_t ip; + u_int16_t port; + struct ip_conntrack_expect *exp = NULL; + + DEBUGP("ip_ct_ras: LCF\n"); + + if (!get_h225_addr(*data, &lcf->callSignalAddress, &ip, &port)) + return 0; + + /* Need new expect for call signal */ + if ((exp = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + exp->tuple.src.u.tcp.port = 0; + exp->tuple.dst.ip = ip; + exp->tuple.dst.u.tcp.port = htons(port); + exp->tuple.dst.protonum = IPPROTO_TCP; + exp->mask.src.ip = 0xFFFFFFFF; + exp->mask.src.u.tcp.port = 0; + exp->mask.dst.ip = 0xFFFFFFFF; + exp->mask.dst.u.tcp.port = 0xFFFF; + exp->mask.dst.protonum = 0xFF; + exp->flags = IP_CT_EXPECT_PERMANENT; + exp->expectfn = ip_conntrack_q931_expect; + + if (ip_conntrack_expect_related(exp) == 0) { + DEBUGP("ip_ct_ras: expect Q.931 " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port)); + } else + ret = -1; + + ip_conntrack_expect_put(exp); + + /* Ignore rasAddress */ + + return ret; +} + +/****************************************************************************/ +static int process_irr(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, InfoRequestResponse * irr) +{ + int ret; + + DEBUGP("ip_ct_ras: IRR\n"); + + if (set_ras_addr_hook) { + ret = set_ras_addr_hook(pskb, ct, ctinfo, data, + &irr->rasAddress, 1); + if (ret < 0) + return -1; + } + + if (set_sig_addr_hook) { + ret = set_sig_addr_hook(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 ip_conntrack *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("ip_ct_ras: RAS message %d\n", ras->choice); + break; + } + + return 0; +} + +/****************************************************************************/ +static int ras_help(struct sk_buff **pskb, struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo) +{ + static RasMessage ras; + unsigned char *data; + int datalen = 0; + int ret; + + DEBUGP("ip_ct_ras: skblen = %u\n", (*pskb)->len); + + spin_lock_bh(&ip_h323_lock); + + /* Get UDP data */ + data = get_udp_data(pskb, &datalen); + if (data == NULL) + goto accept; + DEBUGP("ip_ct_ras: RAS message %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n", + NIPQUAD((*pskb)->nh.iph->saddr), + NIPQUAD((*pskb)->nh.iph->daddr), datalen); + + /* Decode RAS message */ + ret = DecodeRasMessage(data, datalen, &ras); + if (ret < 0) { + if (net_ratelimit()) + printk("ip_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(&ip_h323_lock); + return NF_ACCEPT; + + drop: + spin_unlock_bh(&ip_h323_lock); + if (net_ratelimit()) + printk("ip_ct_ras: packet dropped\n"); + return NF_DROP; +} + +/****************************************************************************/ +static struct ip_conntrack_helper ip_conntrack_helper_ras = { + .name = "RAS", + .me = THIS_MODULE, + .max_expected = 32, + .timeout = 240, + .tuple = {.src = {.u = {__constant_htons(RAS_PORT)}}, + .dst = {.protonum = IPPROTO_UDP}}, + .mask = {.src = {.u = {0xFFFE}}, + .dst = {.protonum = 0xFF}}, + .help = ras_help, +}; + +/****************************************************************************/ +static void ip_conntrack_ras_expect(struct ip_conntrack *new, + struct ip_conntrack_expect *this) +{ + write_lock_bh(&ip_conntrack_lock); + new->helper = &ip_conntrack_helper_ras; + write_unlock_bh(&ip_conntrack_lock); +} + +/****************************************************************************/ +/* Not __exit - called from init() */ +static void fini(void) +{ + ip_conntrack_helper_unregister(&ip_conntrack_helper_ras); + ip_conntrack_helper_unregister(&ip_conntrack_helper_q931); + kfree(h323_buffer); + DEBUGP("ip_ct_h323: fini\n"); +} + +/****************************************************************************/ +static int __init init(void) +{ + int ret; + + h323_buffer = kmalloc(65536, GFP_KERNEL); + if (!h323_buffer) + return -ENOMEM; + if ((ret = ip_conntrack_helper_register(&ip_conntrack_helper_q931)) || + (ret = ip_conntrack_helper_register(&ip_conntrack_helper_ras))) { + fini(); + return ret; + } + + DEBUGP("ip_ct_h323: init success\n"); + return 0; +} + +/****************************************************************************/ +module_init(init); +module_exit(fini); + +EXPORT_SYMBOL(get_h245_addr); +EXPORT_SYMBOL(get_h225_addr); +EXPORT_SYMBOL(ip_conntrack_h245_expect); +EXPORT_SYMBOL(ip_conntrack_q931_expect); +EXPORT_SYMBOL(set_h245_addr_hook); +EXPORT_SYMBOL(set_h225_addr_hook); +EXPORT_SYMBOL(set_sig_addr_hook); +EXPORT_SYMBOL(set_ras_addr_hook); +EXPORT_SYMBOL(nat_rtp_rtcp_hook); +EXPORT_SYMBOL(nat_t120_hook); +EXPORT_SYMBOL(nat_h245_hook); +EXPORT_SYMBOL(nat_q931_hook); + +MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>"); +MODULE_DESCRIPTION("H.323 connection tracking helper"); +MODULE_LICENSE("GPL"); |