diff options
Diffstat (limited to 'src/or/transports.c')
| -rw-r--r-- | src/or/transports.c | 373 |
1 files changed, 320 insertions, 53 deletions
diff --git a/src/or/transports.c b/src/or/transports.c index 4ba239562a..dd07a917ee 100644 --- a/src/or/transports.c +++ b/src/or/transports.c @@ -39,13 +39,17 @@ * transport_t structs. * * When the managed proxy stops spitting METHOD lines (signified by a - * '{S,C}METHODS DONE' message) we register all the transports - * collected to the circuitbuild.c subsystem. At this point, the - * pointers to transport_t can be transformed into dangling pointers - * at any point by the circuitbuild.c subsystem, and so we replace all - * transport_t pointers with strings describing the transport names. - * We can still go from a transport name to a transport_t using the - * fact that each transport name uniquely identifies a transport_t. + * '{S,C}METHODS DONE' message) we pass copies of its transports to + * the bridge subsystem. We keep copies of the 'transport_t's on the + * managed proxy to be able to associate the proxy with its + * transports, and we pass copies to the bridge subsystem so that + * transports can be associated with bridges. + * [ XXX We should try see whether the two copies are really needed + * and maybe cut it into a single copy of the 'transport_t' shared + * between the managed proxy and the bridge subsystem. Preliminary + * analysis shows that both copies are needed with the current code + * logic, because of race conditions that can cause dangling + * pointers. ] * * <b>In even more detail, this is what happens when a SIGHUP * occurs:</b> @@ -127,6 +131,219 @@ static INLINE void free_execve_args(char **arg); protocol version. */ #define PROTO_VERSION_ONE 1 +/** A list of pluggable transports found in torrc. */ +static smartlist_t *transport_list = NULL; + +/** Returns a transport_t struct for a transport proxy supporting the + protocol <b>name</b> listening at <b>addr</b>:<b>port</b> using + SOCKS version <b>socks_ver</b>. */ +static transport_t * +transport_new(const tor_addr_t *addr, uint16_t port, + const char *name, int socks_ver) +{ + transport_t *t = tor_malloc_zero(sizeof(transport_t)); + + tor_addr_copy(&t->addr, addr); + t->port = port; + t->name = tor_strdup(name); + t->socks_version = socks_ver; + + return t; +} + +/** Free the pluggable transport struct <b>transport</b>. */ +void +transport_free(transport_t *transport) +{ + if (!transport) + return; + + tor_free(transport->name); + tor_free(transport); +} + +/** Mark every entry of the transport list to be removed on our next call to + * sweep_transport_list unless it has first been un-marked. */ +void +mark_transport_list(void) +{ + if (!transport_list) + transport_list = smartlist_new(); + SMARTLIST_FOREACH(transport_list, transport_t *, t, + t->marked_for_removal = 1); +} + +/** Remove every entry of the transport list that was marked with + * mark_transport_list if it has not subsequently been un-marked. */ +void +sweep_transport_list(void) +{ + if (!transport_list) + transport_list = smartlist_new(); + SMARTLIST_FOREACH_BEGIN(transport_list, transport_t *, t) { + if (t->marked_for_removal) { + SMARTLIST_DEL_CURRENT(transport_list, t); + transport_free(t); + } + } SMARTLIST_FOREACH_END(t); +} + +/** Initialize the pluggable transports list to empty, creating it if + * needed. */ +static void +clear_transport_list(void) +{ + if (!transport_list) + transport_list = smartlist_new(); + SMARTLIST_FOREACH(transport_list, transport_t *, t, transport_free(t)); + smartlist_clear(transport_list); +} + +/** Return a deep copy of <b>transport</b>. */ +static transport_t * +transport_copy(const transport_t *transport) +{ + transport_t *new_transport = NULL; + + tor_assert(transport); + + new_transport = tor_malloc_zero(sizeof(transport_t)); + + new_transport->socks_version = transport->socks_version; + new_transport->name = tor_strdup(transport->name); + tor_addr_copy(&new_transport->addr, &transport->addr); + new_transport->port = transport->port; + new_transport->marked_for_removal = transport->marked_for_removal; + + return new_transport; +} + +/** Returns the transport in our transport list that has the name <b>name</b>. + * Else returns NULL. */ +transport_t * +transport_get_by_name(const char *name) +{ + tor_assert(name); + + if (!transport_list) + return NULL; + + SMARTLIST_FOREACH_BEGIN(transport_list, transport_t *, transport) { + if (!strcmp(transport->name, name)) + return transport; + } SMARTLIST_FOREACH_END(transport); + + return NULL; +} + +/** Resolve any conflicts that the insertion of transport <b>t</b> + * might cause. + * Return 0 if <b>t</b> is OK and should be registered, 1 if there is + * a transport identical to <b>t</b> already registered and -1 if + * <b>t</b> cannot be added due to conflicts. */ +static int +transport_resolve_conflicts(const transport_t *t) +{ + /* This is how we resolve transport conflicts: + + If there is already a transport with the same name and addrport, + we either have duplicate torrc lines OR we are here post-HUP and + this transport was here pre-HUP as well. In any case, mark the + old transport so that it doesn't get removed and ignore the new + one. Our caller has to free the new transport so we return '1' to + signify this. + + If there is already a transport with the same name but different + addrport: + * if it's marked for removal, it means that it either has a lower + priority than 't' in torrc (otherwise the mark would have been + cleared by the paragraph above), or it doesn't exist at all in + the post-HUP torrc. We destroy the old transport and register 't'. + * if it's *not* marked for removal, it means that it was newly + added in the post-HUP torrc or that it's of higher priority, in + this case we ignore 't'. */ + transport_t *t_tmp = transport_get_by_name(t->name); + if (t_tmp) { /* same name */ + if (tor_addr_eq(&t->addr, &t_tmp->addr) && (t->port == t_tmp->port)) { + /* same name *and* addrport */ + t_tmp->marked_for_removal = 0; + return 1; + } else { /* same name but different addrport */ + if (t_tmp->marked_for_removal) { /* marked for removal */ + log_notice(LD_GENERAL, "You tried to add transport '%s' at '%s:%u' " + "but there was already a transport marked for deletion at " + "'%s:%u'. We deleted the old transport and registered the " + "new one.", t->name, fmt_addr(&t->addr), t->port, + fmt_addr(&t_tmp->addr), t_tmp->port); + smartlist_remove(transport_list, t_tmp); + transport_free(t_tmp); + } else { /* *not* marked for removal */ + log_notice(LD_GENERAL, "You tried to add transport '%s' at '%s:%u' " + "but the same transport already exists at '%s:%u'. " + "Skipping.", t->name, fmt_addr(&t->addr), t->port, + fmt_addr(&t_tmp->addr), t_tmp->port); + return -1; + } + } + } + + return 0; +} + +/** Add transport <b>t</b> to the internal list of pluggable + * transports. + * Returns 0 if the transport was added correctly, 1 if the same + * transport was already registered (in this case the caller must + * free the transport) and -1 if there was an error. */ +static int +transport_add(transport_t *t) +{ + int r; + tor_assert(t); + + r = transport_resolve_conflicts(t); + + switch (r) { + case 0: /* should register transport */ + if (!transport_list) + transport_list = smartlist_new(); + smartlist_add(transport_list, t); + return 0; + default: /* let our caller know the return code */ + return r; + } +} + +/** Remember a new pluggable transport proxy at <b>addr</b>:<b>port</b>. + * <b>name</b> is set to the name of the protocol this proxy uses. + * <b>socks_ver</b> is set to the SOCKS version of the proxy. */ +int +transport_add_from_config(const tor_addr_t *addr, uint16_t port, + const char *name, int socks_ver) +{ + transport_t *t = transport_new(addr, port, name, socks_ver); + + int r = transport_add(t); + + switch (r) { + case -1: + default: + log_notice(LD_GENERAL, "Could not add transport %s at %s:%u. Skipping.", + t->name, fmt_addr(&t->addr), t->port); + transport_free(t); + return -1; + case 1: + log_info(LD_GENERAL, "Succesfully registered transport %s at %s:%u.", + t->name, fmt_addr(&t->addr), t->port); + transport_free(t); /* falling */ + return 0; + case 0: + log_info(LD_GENERAL, "Succesfully registered transport %s at %s:%u.", + t->name, fmt_addr(&t->addr), t->port); + return 0; + } +} + /** List of unconfigured managed proxies. */ static smartlist_t *managed_proxy_list = NULL; /** Number of still unconfigured proxies. */ @@ -217,11 +434,11 @@ proxy_needs_restart(const managed_proxy_t *mp) { /* mp->transport_to_launch is populated with the names of the transports that must be launched *after* the SIGHUP. - mp->transports is populated with the names of the transports that - were launched *before* the SIGHUP. + mp->transports is populated with the transports that were + launched *before* the SIGHUP. - If the two lists contain the same strings, we don't need to - restart the proxy, since it already does what we want. */ + Check if all the transports that need to be launched are already + launched: */ tor_assert(smartlist_len(mp->transports_to_launch) > 0); tor_assert(mp->conf_state == PT_PROTO_COMPLETED); @@ -229,11 +446,11 @@ proxy_needs_restart(const managed_proxy_t *mp) if (smartlist_len(mp->transports_to_launch) != smartlist_len(mp->transports)) goto needs_restart; - SMARTLIST_FOREACH_BEGIN(mp->transports_to_launch, char *, t_t_l) { - if (!smartlist_string_isin(mp->transports, t_t_l)) + SMARTLIST_FOREACH_BEGIN(mp->transports, const transport_t *, t) { + if (!smartlist_string_isin(mp->transports_to_launch, t->name)) goto needs_restart; - } SMARTLIST_FOREACH_END(t_t_l); + } SMARTLIST_FOREACH_END(t); return 0; @@ -245,6 +462,7 @@ proxy_needs_restart(const managed_proxy_t *mp) * preparations and then flag its state so that it will be relaunched * in the next tick. */ static void + proxy_prepare_for_restart(managed_proxy_t *mp) { transport_t *t_tmp = NULL; @@ -255,16 +473,17 @@ proxy_prepare_for_restart(managed_proxy_t *mp) tor_process_handle_destroy(mp->process_handle, 1); mp->process_handle = NULL; - /* destroy all its old transports. we no longer use them. */ - SMARTLIST_FOREACH_BEGIN(mp->transports, const char *, t_name) { - t_tmp = transport_get_by_name(t_name); + /* destroy all its registered transports, since we will no longer + use them. */ + SMARTLIST_FOREACH_BEGIN(mp->transports, const transport_t *, t) { + t_tmp = transport_get_by_name(t->name); if (t_tmp) t_tmp->marked_for_removal = 1; - } SMARTLIST_FOREACH_END(t_name); + } SMARTLIST_FOREACH_END(t); sweep_transport_list(); - /* free the transport names in mp->transports */ - SMARTLIST_FOREACH(mp->transports, char *, t_name, tor_free(t_name)); + /* free the transport in mp->transports */ + SMARTLIST_FOREACH(mp->transports, transport_t *, t, transport_free(t)); smartlist_clear(mp->transports); /* flag it as an infant proxy so that it gets launched on next tick */ @@ -315,6 +534,7 @@ launch_managed_proxy(managed_proxy_t *mp) void pt_configure_remaining_proxies(void) { + int at_least_a_proxy_config_finished = 0; smartlist_t *tmp = smartlist_new(); log_debug(LD_CONFIG, "Configuring remaining managed proxies (%d)!", @@ -352,11 +572,17 @@ pt_configure_remaining_proxies(void) if (!proxy_configuration_finished(mp)) configure_proxy(mp); + if (proxy_configuration_finished(mp)) + at_least_a_proxy_config_finished = 1; + } SMARTLIST_FOREACH_END(mp); smartlist_free(tmp); check_if_restarts_needed = 0; assert_unconfigured_count_ok(); + + if (at_least_a_proxy_config_finished) + mark_my_descriptor_dirty("configured managed proxies"); } #ifdef _WIN32 @@ -468,68 +694,48 @@ configure_proxy(managed_proxy_t *mp) /** Register server managed proxy <b>mp</b> transports to state */ static void -register_server_proxy(managed_proxy_t *mp) +register_server_proxy(const managed_proxy_t *mp) { - /* After we register this proxy's transports, we switch its - mp->transports to a list containing strings of its transport - names. (See transports.h) */ - smartlist_t *sm_tmp = smartlist_new(); - tor_assert(mp->conf_state != PT_PROTO_COMPLETED); + SMARTLIST_FOREACH_BEGIN(mp->transports, transport_t *, t) { save_transport_to_state(t->name, &t->addr, t->port); log_notice(LD_GENERAL, "Registered server transport '%s' at '%s:%d'", t->name, fmt_addr(&t->addr), (int)t->port); - smartlist_add(sm_tmp, tor_strdup(t->name)); } SMARTLIST_FOREACH_END(t); - - /* Since server proxies don't register their transports in the - circuitbuild.c subsystem, it's our duty to free them when we - switch mp->transports to strings. */ - SMARTLIST_FOREACH(mp->transports, transport_t *, t, transport_free(t)); - smartlist_free(mp->transports); - - mp->transports = sm_tmp; } /** Register all the transports supported by client managed proxy * <b>mp</b> to the bridge subsystem. */ static void -register_client_proxy(managed_proxy_t *mp) +register_client_proxy(const managed_proxy_t *mp) { int r; - /* After we register this proxy's transports, we switch its - mp->transports to a list containing strings of its transport - names. (See transports.h) */ - smartlist_t *sm_tmp = smartlist_new(); tor_assert(mp->conf_state != PT_PROTO_COMPLETED); + SMARTLIST_FOREACH_BEGIN(mp->transports, transport_t *, t) { - r = transport_add(t); + transport_t *transport_tmp = transport_copy(t); + r = transport_add(transport_tmp); switch (r) { case -1: log_notice(LD_GENERAL, "Could not add transport %s. Skipping.", t->name); - transport_free(t); + transport_free(transport_tmp); break; case 0: log_info(LD_GENERAL, "Succesfully registered transport %s", t->name); - smartlist_add(sm_tmp, tor_strdup(t->name)); break; case 1: log_info(LD_GENERAL, "Succesfully registered transport %s", t->name); - smartlist_add(sm_tmp, tor_strdup(t->name)); - transport_free(t); + transport_free(transport_tmp); break; } } SMARTLIST_FOREACH_END(t); - - smartlist_free(mp->transports); - mp->transports = sm_tmp; } /** Register the transports of managed proxy <b>mp</b>. */ static INLINE void -register_proxy(managed_proxy_t *mp) +register_proxy(const managed_proxy_t *mp) { if (mp->is_server) register_server_proxy(mp); @@ -542,10 +748,7 @@ static void managed_proxy_destroy(managed_proxy_t *mp, int also_terminate_process) { - if (mp->conf_state != PT_PROTO_COMPLETED) - SMARTLIST_FOREACH(mp->transports, transport_t *, t, transport_free(t)); - else - SMARTLIST_FOREACH(mp->transports, char *, t_name, tor_free(t_name)); + SMARTLIST_FOREACH(mp->transports, transport_t *, t, transport_free(t)); /* free the transports smartlist */ smartlist_free(mp->transports); @@ -1181,6 +1384,64 @@ pt_prepare_proxy_list_for_config_read(void) tor_assert(unconfigured_proxies_n == 0); } +/** Return the pluggable transport string that we should display in + * our extra-info descriptor. If we shouldn't display such a string, + * or we have nothing to display, return NULL. The string is + * allocated on the heap and it's the responsibility of the caller to + * free it. */ +char * +pt_get_extra_info_descriptor_string(void) +{ + char *the_string = NULL; + smartlist_t *string_chunks = NULL; + + if (!managed_proxy_list) + return NULL; + + string_chunks = smartlist_new(); + + /* For each managed proxy, add its transports to the chunks list. */ + SMARTLIST_FOREACH_BEGIN(managed_proxy_list, const managed_proxy_t *, mp) { + if ((!mp->is_server) || (mp->conf_state != PT_PROTO_COMPLETED)) + continue; + + tor_assert(mp->transports); + + SMARTLIST_FOREACH_BEGIN(mp->transports, const transport_t *, t) { + /* If the transport proxy returned "0.0.0.0" as its address, and + * we know our external IP address, use it. Otherwise, use the + * returned address. */ + const char *addr_str = fmt_addr(&t->addr); + uint32_t external_ip_address = 0; + if (tor_addr_is_null(&t->addr) && + router_pick_published_address(get_options(), + &external_ip_address) >= 0) { + /* returned addr was 0.0.0.0 and we found our external IP + address: use it. */ + addr_str = fmt_addr32(external_ip_address); + } + + smartlist_add_asprintf(string_chunks, + "transport %s %s:%u", + t->name, addr_str, t->port); + } SMARTLIST_FOREACH_END(t); + + } SMARTLIST_FOREACH_END(mp); + + if (smartlist_len(string_chunks) == 0) { + smartlist_free(string_chunks); + return NULL; + } + + /* Join all the chunks into the final string. */ + the_string = smartlist_join_strings(string_chunks, "\n", 1, NULL); + + SMARTLIST_FOREACH(string_chunks, char *, s, tor_free(s)); + smartlist_free(string_chunks); + + return the_string; +} + /** The tor config was read. * Destroy all managed proxies that were marked by a previous call to * prepare_proxy_list_for_config_read() and are not used by the new @@ -1204,6 +1465,12 @@ sweep_proxy_list(void) void pt_free_all(void) { + if (transport_list) { + clear_transport_list(); + smartlist_free(transport_list); + transport_list = NULL; + } + if (managed_proxy_list) { /* If the proxy is in PT_PROTO_COMPLETED, it has registered its transports and it's the duty of the circuitbuild.c subsystem to |