diff options
Diffstat (limited to 'modules/natbd/natbd.c')
| -rw-r--r-- | modules/natbd/natbd.c | 508 |
1 files changed, 508 insertions, 0 deletions
diff --git a/modules/natbd/natbd.c b/modules/natbd/natbd.c new file mode 100644 index 0000000..6711961 --- /dev/null +++ b/modules/natbd/natbd.c @@ -0,0 +1,508 @@ +/** + * @file natbd.c NAT Behavior Discovery Module + * + * Copyright (C) 2010 Creytiv.com + */ +#include <re.h> +#include <baresip.h> + + +#define DEBUG_MODULE "natbd" +#define DEBUG_LEVEL 5 +#include <re_dbg.h> + + +/* + * NAT Behavior Discovery Using STUN (RFC 5780) + * + * This module is only for diagnostics purposes and does not affect + * the main SIP client. It uses the NATBD api in libre to detect the + * NAT Behaviour, by sending STUN packets to a STUN server. Both + * protocols UDP and TCP are supported. + */ + + +struct natbd { + struct nat_hairpinning *nh; + struct nat_filtering *nf; + struct nat_lifetime *nl; + struct nat_mapping *nm; + struct nat_genalg *ga; + struct stun_dns *dns; + struct sa stun_srv; + struct tmr tmr; + char host[256]; + uint16_t port; + uint32_t interval; + bool terminated; + int proto; + int res_hp; + enum nat_type res_nm; + enum nat_type res_nf; + struct nat_lifetime_interval res_nl; + uint32_t n_nl; + int status_ga; +}; + +static struct natbd *natbdv[2]; + + +static const char *hairpinning_str(int res_hp) +{ + switch (res_hp) { + + case -1: return "Unknown"; + case 0: return "Not Supported"; + default: return "Supported"; + } +} + + +static const char *genalg_str(int status) +{ + switch (status) { + + case -1: return "Not Detected"; + case 0: return "Unknown"; + case 1: return "Detected"; + default: return "???"; + } +} + + +static int natbd_status(struct re_printf *pf, void *arg) +{ + const struct natbd *natbd = arg; + int err; + + if (!pf || !natbd) + return 0; + + err = re_hprintf(pf, "NAT Binding Discovery (using %s:%J)\n", + net_proto2name(natbd->proto), + &natbd->stun_srv); + err |= re_hprintf(pf, " Hairpinning: %s\n", + hairpinning_str(natbd->res_hp)); + err |= re_hprintf(pf, " Mapping: %s\n", + nat_type_str(natbd->res_nm)); + if (natbd->proto == IPPROTO_UDP) { + err |= re_hprintf(pf, " Filtering: %s\n", + nat_type_str(natbd->res_nf)); + err |= re_hprintf(pf, " Lifetime: min=%u cur=%u max=%u" + " (%u probes)\n", natbd->res_nl.min, + natbd->res_nl.cur, natbd->res_nl.max, + natbd->n_nl); + } + err |= re_hprintf(pf, " Generic ALG: %s\n", + genalg_str(natbd->status_ga)); + + return err; +} + + +static void nat_hairpinning_handler(int err, bool supported, void *arg) +{ + struct natbd *natbd = arg; + const int res_hp = (0 == err) ? supported : -1; + + if (natbd->terminated) + return; + + if (res_hp != natbd->res_hp) { + info("NAT Hairpinning %s changed from (%s) to (%s)\n", + net_proto2name(natbd->proto), + hairpinning_str(natbd->res_hp), + hairpinning_str(res_hp)); + } + + natbd->res_hp = res_hp; + + natbd->nh = mem_deref(natbd->nh); +} + + +static void nat_mapping_handler(int err, enum nat_type type, void *arg) +{ + struct natbd *natbd = arg; + + if (natbd->terminated) + return; + + if (err) { + DEBUG_WARNING("NAT mapping failed (%m)\n", err); + goto out; + } + + if (type != natbd->res_nm) { + info("NAT Mapping %s changed from (%s) to (%s)\n", + net_proto2name(natbd->proto), + nat_type_str(natbd->res_nm), + nat_type_str(type)); + } + + natbd->res_nm = type; + + out: + natbd->nm = mem_deref(natbd->nm); +} + + +static void nat_filtering_handler(int err, enum nat_type type, void *arg) +{ + struct natbd *natbd = arg; + + if (natbd->terminated) + return; + + if (err) { + DEBUG_WARNING("NAT filtering failed (%m)\n", err); + goto out; + } + + if (type != natbd->res_nf) { + info("NAT Filtering %s changed from (%s) to (%s)\n", + net_proto2name(natbd->proto), + nat_type_str(natbd->res_nf), + nat_type_str(type)); + } + + natbd->res_nf = type; + + out: + natbd->nf = mem_deref(natbd->nf); +} + + +static void nat_lifetime_handler(int err, + const struct nat_lifetime_interval *interval, + void *arg) +{ + struct natbd *natbd = arg; + + ++natbd->n_nl; + + if (err) { + DEBUG_WARNING("nat_lifetime_handler: (%m)\n", err); + return; + } + + natbd->res_nl = *interval; + + info("NAT Binding lifetime for %s: min=%u cur=%u max=%u\n", + net_proto2name(natbd->proto), + interval->min, interval->cur, interval->max); +} + + +static void nat_genalg_handler(int err, uint16_t scode, const char *reason, + int status, const struct sa *map, + void *arg) +{ + struct natbd *natbd = arg; + + (void)map; + + if (natbd->terminated) + return; + + if (err) { + DEBUG_WARNING("Generic ALG detection failed: %m\n", err); + goto out; + } + else if (scode) { + DEBUG_WARNING("Generic ALG detection failed: %u %s\n", + scode, reason); + goto out; + } + + if (status != natbd->status_ga) { + info("Generic ALG for %s changed from (%s) to (%s)\n", + net_proto2name(natbd->proto), + genalg_str(natbd->status_ga), + genalg_str(status)); + } + + natbd->status_ga = status; + + out: + natbd->ga = mem_deref(natbd->ga); +} + + +static void destructor(void *arg) +{ + struct natbd *natbd = arg; + + natbd->terminated = true; + + tmr_cancel(&natbd->tmr); + mem_deref(natbd->dns); + mem_deref(natbd->nh); + mem_deref(natbd->nm); + mem_deref(natbd->nf); + mem_deref(natbd->nl); + mem_deref(natbd->ga); +} + + +static int natbd_start(struct natbd *natbd) +{ + int err = 0; + + if (!natbd->nh) { + err |= nat_hairpinning_alloc(&natbd->nh, &natbd->stun_srv, + natbd->proto, NULL, + nat_hairpinning_handler, natbd); + err |= nat_hairpinning_start(natbd->nh); + if (err) { + DEBUG_WARNING("nat_hairpinning_start() failed (%m)\n", + err); + } + } + + if (!natbd->nm) { + err |= nat_mapping_alloc(&natbd->nm, net_laddr_af(net_af()), + &natbd->stun_srv, natbd->proto, NULL, + nat_mapping_handler, natbd); + err |= nat_mapping_start(natbd->nm); + if (err) { + DEBUG_WARNING("nat_mapping_start() failed (%m)\n", + err); + } + } + + if (natbd->proto == IPPROTO_UDP) { + + if (!natbd->nf) { + err |= nat_filtering_alloc(&natbd->nf, + &natbd->stun_srv, NULL, + nat_filtering_handler, + natbd); + err |= nat_filtering_start(natbd->nf); + if (err) { + DEBUG_WARNING("nat_filtering_start() (%m)\n", + err); + } + } + } + + if (!natbd->ga) { + err |= nat_genalg_alloc(&natbd->ga, &natbd->stun_srv, + natbd->proto, NULL, + nat_genalg_handler, natbd); + + if (err) { + DEBUG_WARNING("natbd_init: %m\n", err); + } + err |= nat_genalg_start(natbd->ga); + if (err) { + DEBUG_WARNING("nat_genalg_start() failed (%m)\n", + err); + } + } + + return err; +} + + +static void timeout(void *arg) +{ + struct natbd *natbd = arg; + + info("%H\n", natbd_status, natbd); + + natbd_start(natbd); + + tmr_start(&natbd->tmr, natbd->interval * 1000, timeout, natbd); +} + + +static void dns_handler(int err, const struct sa *addr, void *arg) +{ + struct natbd *natbd = arg; + + if (err) { + DEBUG_WARNING("failed to resolve '%s' (%m)\n", + natbd->host, err); + goto out; + } + + info("natbd: resolved STUN-server for %s -- %J\n", + net_proto2name(natbd->proto), addr); + + sa_cpy(&natbd->stun_srv, addr); + + natbd_start(natbd); + + /* Lifetime discovery is a special test */ + if (natbd->proto == IPPROTO_UDP) { + + err = nat_lifetime_alloc(&natbd->nl, &natbd->stun_srv, 3, + NULL, nat_lifetime_handler, natbd); + err |= nat_lifetime_start(natbd->nl); + if (err) { + DEBUG_WARNING("nat_lifetime_start() failed (%m)\n", + err); + } + } + + tmr_start(&natbd->tmr, natbd->interval * 1000, timeout, natbd); + + out: + natbd->dns = mem_deref(natbd->dns); +} + + +static void timeout_init(void *arg) +{ + struct natbd *natbd = arg; + const char *proto_str; + int err = 0; + + if (sa_isset(&natbd->stun_srv, SA_ALL)) { + dns_handler(0, &natbd->stun_srv, natbd); + return; + } + + if (natbd->proto == IPPROTO_UDP) + proto_str = stun_proto_udp; + else if (natbd->proto == IPPROTO_TCP) + proto_str = stun_proto_tcp; + else { + err = EPROTONOSUPPORT; + goto out; + } + + err = stun_server_discover(&natbd->dns, net_dnsc(), + stun_usage_binding, + proto_str, net_af(), + natbd->host, natbd->port, + dns_handler, natbd); + if (err) + goto out; + + out: + if (err) { + DEBUG_WARNING("timeout_init: %m\n", err); + } +} + + +static int natbd_alloc(struct natbd **natbdp, uint32_t interval, + int proto, const char *server) +{ + struct pl host, port; + struct natbd *natbd; + int err = 0; + + if (!natbdp || !interval || !proto || !server) + return EINVAL; + + natbd = mem_zalloc(sizeof(*natbd), destructor); + if (!natbd) + return ENOMEM; + + natbd->interval = interval; + natbd->proto = proto; + natbd->res_hp = -1; + + if (0 == sa_decode(&natbd->stun_srv, server, str_len(server))) { + ; + } + else if (0 == re_regex(server, str_len(server), "[^:]+[:]*[^]*", + &host, NULL, &port)) { + + pl_strcpy(&host, natbd->host, sizeof(natbd->host)); + natbd->port = pl_u32(&port); + } + else { + DEBUG_WARNING("failed to decode natbd_server (%s)\n", + server); + err = EINVAL; + goto out; + } + + tmr_start(&natbd->tmr, 1, timeout_init, natbd); + + out: + if (err) + mem_deref(natbd); + else + *natbdp = natbd; + + return err; +} + + +static int status(struct re_printf *pf, void *unused) +{ + size_t i; + int err = 0; + + (void)unused; + + for (i=0; i<ARRAY_SIZE(natbdv); i++) { + + if (natbdv[i]) + err |= natbd_status(pf, natbdv[i]); + } + + return err; +} + + +static const struct cmd cmdv[] = { + {'z', 0, "NAT status", status} +}; + + +static int module_init(void) +{ + char server[256] = ""; + uint32_t interval = 3600; + int err; + + err = cmd_register(cmdv, ARRAY_SIZE(cmdv)); + if (err) + return err; + + (void)conf_get_u32(conf_cur(), "natbd_interval", &interval); + (void)conf_get_str(conf_cur(), "natbd_server", server, sizeof(server)); + + if (!server[0]) { + DEBUG_WARNING("missing config 'natbd_server'\n"); + return EINVAL; + } + + info("natbd: Enable NAT Behavior Discovery using STUN server %s\n", + server); + + err |= natbd_alloc(&natbdv[0], interval, IPPROTO_UDP, server); + err |= natbd_alloc(&natbdv[1], interval, IPPROTO_TCP, server); + if (err) { + DEBUG_WARNING("failed to allocate natbd state: %m\n", err); + } + + return err; +} + + +static int module_close(void) +{ + size_t i; + + for (i=0; i<ARRAY_SIZE(natbdv); i++) + natbdv[i] = mem_deref(natbdv[i]); + + cmd_unregister(cmdv); + + return 0; +} + + +EXPORT_SYM const struct mod_export DECL_EXPORTS(natbd) = { + "natbd", + "natbd", + module_init, + module_close, +}; |