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- /* Copyright (c) 2011, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file transports.c
- * \brief Pluggable Transports related code.
- *
- * \details
- * Each managed proxy is represented by a <b>managed_proxy_t</b>.
- * Each managed proxy can support multiple transports.
- * Each managed proxy gets configured through a multistep process.
- *
- * ::managed_proxy_list contains all the managed proxies this tor
- * instance is supporting.
- * In the ::managed_proxy_list there are ::unconfigured_proxies_n
- * managed proxies that are still unconfigured.
- *
- * In every run_scheduled_event() tick, we attempt to launch and then
- * configure the unconfiged managed proxies, using the configuration
- * protocol defined in the 180_pluggable_transport.txt proposal. A
- * managed proxy might need several ticks to get fully configured.
- *
- * When a managed proxy is fully configured, we register all its
- * transports to the circuitbuild.c subsystem. At that point the
- * transports are owned by the circuitbuild.c subsystem.
- *
- * When a managed proxy fails to follow the 180 configuration
- * protocol, it gets marked as broken and gets destroyed.
- *
- * <b>In a little more detail:</b>
- *
- * While we are serially parsing torrc, we store all the transports
- * that a proxy should spawn in its <em>transports_to_launch</em>
- * element.
- *
- * When we finish reading the torrc, we spawn the managed proxy and
- * expect {S,C}METHOD lines from its output. We add transports
- * described by METHOD lines to its <em>transports</em> element, as
- * 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.
- *
- * <b>In even more detail, this is what happens when a SIGHUP
- * occurs:</b>
- *
- * We immediately destroy all unconfigured proxies (We shouldn't have
- * unconfigured proxies in the first place, except when SIGHUP rings
- * immediately after tor is launched.).
- *
- * We mark all managed proxies and transports to signify that they
- * must be removed if they don't contribute by the new torrc
- * (we mark using the <b>marked_for_removal</b> element).
- * We also mark all managed proxies to signify that they might need to
- * be restarted so that they end up supporting all the transports the
- * new torrc wants them to support (using the <b>got_hup</b> element).
- * We also clear their <b>transports_to_launch</b> list so that we can
- * put there the transports we need to launch according to the new
- * torrc.
- *
- * We then start parsing torrc again.
- *
- * Everytime we encounter a transport line using a known pre-SIGHUP
- * managed proxy, we cleanse that proxy from the removal mark.
- * We also mark it as unconfigured so that on the next scheduled
- * events tick, we investigate whether we need to restart the proxy
- * so that it also spawns the new transports.
- * If the post-SIGHUP <b>transports_to_launch</b> list is identical to
- * the pre-SIGHUP one, it means that no changes were introduced to
- * this proxy during the SIGHUP and no restart has to take place.
- *
- * During the post-SIGHUP torrc parsing, we unmark all transports
- * spawned by managed proxies that we find in our torrc.
- * We do that so that if we don't need to restart a managed proxy, we
- * can continue using its old transports normally.
- * If we end up restarting the proxy, we destroy and unregister all
- * old transports from the circuitbuild.c subsystem.
- **/
- #define PT_PRIVATE
- #include "or.h"
- #include "config.h"
- #include "circuitbuild.h"
- #include "transports.h"
- #include "util.h"
- #include "router.h"
- static process_environment_t *
- create_managed_proxy_environment(const managed_proxy_t *mp);
- static INLINE int proxy_configuration_finished(const managed_proxy_t *mp);
- static void managed_proxy_destroy(managed_proxy_t *mp,
- int also_terminate_process);
- static void handle_finished_proxy(managed_proxy_t *mp);
- static void configure_proxy(managed_proxy_t *mp);
- static void parse_method_error(const char *line, int is_server_method);
- #define parse_server_method_error(l) parse_method_error(l, 1)
- #define parse_client_method_error(l) parse_method_error(l, 0)
- static INLINE void free_execve_args(char **arg);
- /** Managed proxy protocol strings */
- #define PROTO_ENV_ERROR "ENV-ERROR"
- #define PROTO_NEG_SUCCESS "VERSION"
- #define PROTO_NEG_FAIL "VERSION-ERROR no-version"
- #define PROTO_CMETHOD "CMETHOD"
- #define PROTO_SMETHOD "SMETHOD"
- #define PROTO_CMETHOD_ERROR "CMETHOD-ERROR"
- #define PROTO_SMETHOD_ERROR "SMETHOD-ERROR"
- #define PROTO_CMETHODS_DONE "CMETHODS DONE"
- #define PROTO_SMETHODS_DONE "SMETHODS DONE"
- /* The smallest valid managed proxy protocol line that can
- appear. It's the size of "VERSION 1" */
- #define SMALLEST_MANAGED_LINE_SIZE 9
- /** Number of environment variables for managed proxy clients/servers. */
- #define ENVIRON_SIZE_CLIENT 3
- #define ENVIRON_SIZE_SERVER 7 /* XXX known to be too high, but that's ok */
- /** The first and only supported - at the moment - configuration
- protocol version. */
- #define PROTO_VERSION_ONE 1
- /** List of unconfigured managed proxies. */
- static smartlist_t *managed_proxy_list = NULL;
- /** Number of still unconfigured proxies. */
- static int unconfigured_proxies_n = 0;
- /** Boolean: True iff we might need to restart some proxies. */
- static int check_if_restarts_needed = 0;
- /** Return true if there are still unconfigured managed proxies, or proxies
- * that need restarting. */
- int
- pt_proxies_configuration_pending(void)
- {
- return unconfigured_proxies_n || check_if_restarts_needed;
- }
- /** Assert that the unconfigured_proxies_n value correctly matches the number
- * of proxies in a state other than PT_PROTO_COMPLETE. */
- static void
- assert_unconfigured_count_ok(void)
- {
- int n_completed = 0;
- if (!managed_proxy_list) {
- tor_assert(unconfigured_proxies_n == 0);
- return;
- }
- SMARTLIST_FOREACH(managed_proxy_list, managed_proxy_t *, mp, {
- if (mp->conf_state == PT_PROTO_COMPLETED)
- ++n_completed;
- });
- tor_assert(n_completed + unconfigured_proxies_n ==
- smartlist_len(managed_proxy_list));
- }
- /** Return true if <b>mp</b> has the same argv as <b>proxy_argv</b> */
- static int
- managed_proxy_has_argv(const managed_proxy_t *mp, char **proxy_argv)
- {
- char **tmp1=proxy_argv;
- char **tmp2=mp->argv;
- tor_assert(tmp1);
- tor_assert(tmp2);
- while (*tmp1 && *tmp2) {
- if (strcmp(*tmp1++, *tmp2++))
- return 0;
- }
- if (!*tmp1 && !*tmp2)
- return 1;
- return 0;
- }
- /** Return a managed proxy with the same argv as <b>proxy_argv</b>.
- * If no such managed proxy exists, return NULL. */
- static managed_proxy_t *
- get_managed_proxy_by_argv_and_type(char **proxy_argv, int is_server)
- {
- if (!managed_proxy_list)
- return NULL;
- SMARTLIST_FOREACH_BEGIN(managed_proxy_list, managed_proxy_t *, mp) {
- if (managed_proxy_has_argv(mp, proxy_argv) &&
- mp->is_server == is_server)
- return mp;
- } SMARTLIST_FOREACH_END(mp);
- return NULL;
- }
- /** Add <b>transport</b> to managed proxy <b>mp</b>. */
- static void
- add_transport_to_proxy(const char *transport, managed_proxy_t *mp)
- {
- tor_assert(mp->transports_to_launch);
- if (!smartlist_string_isin(mp->transports_to_launch, transport))
- smartlist_add(mp->transports_to_launch, tor_strdup(transport));
- }
- /** Called when a SIGHUP occurs. Returns true if managed proxy
- * <b>mp</b> needs to be restarted after the SIGHUP, based on the new
- * torrc. */
- static int
- 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.
- If the two lists contain the same strings, we don't need to
- restart the proxy, since it already does what we want. */
- tor_assert(smartlist_len(mp->transports_to_launch) > 0);
- tor_assert(mp->conf_state == PT_PROTO_COMPLETED);
- 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))
- goto needs_restart;
- } SMARTLIST_FOREACH_END(t_t_l);
- return 0;
- needs_restart:
- return 1;
- }
- /** Managed proxy <b>mp</b> must be restarted. Do all the necessary
- * 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;
- tor_assert(mp->conf_state == PT_PROTO_COMPLETED);
- /* destroy the process handle and terminate the process. */
- 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);
- if (t_tmp)
- t_tmp->marked_for_removal = 1;
- } SMARTLIST_FOREACH_END(t_name);
- sweep_transport_list();
- /* free the transport names in mp->transports */
- SMARTLIST_FOREACH(mp->transports, char *, t_name, tor_free(t_name));
- smartlist_clear(mp->transports);
- /* flag it as an infant proxy so that it gets launched on next tick */
- mp->conf_state = PT_PROTO_INFANT;
- unconfigured_proxies_n++;
- }
- /** Launch managed proxy <b>mp</b>. */
- static int
- launch_managed_proxy(managed_proxy_t *mp)
- {
- int retval;
- process_environment_t *env = create_managed_proxy_environment(mp);
- #ifdef _WIN32
- /* Passing NULL as lpApplicationName makes Windows search for the .exe */
- retval = tor_spawn_background(NULL,
- (const char **)mp->argv,
- env,
- &mp->process_handle);
- #else
- retval = tor_spawn_background(mp->argv[0],
- (const char **)mp->argv,
- env,
- &mp->process_handle);
- #endif
- process_environment_free(env);
- if (retval == PROCESS_STATUS_ERROR) {
- log_warn(LD_GENERAL, "Managed proxy at '%s' failed at launch.",
- mp->argv[0]);
- return -1;
- }
- log_info(LD_CONFIG, "Managed proxy at '%s' has spawned with PID '%d'.",
- mp->argv[0], tor_process_get_pid(mp->process_handle));
- mp->conf_state = PT_PROTO_LAUNCHED;
- return 0;
- }
- /** Check if any of the managed proxies we are currently trying to
- * configure have anything new to say. This is called from
- * run_scheduled_events(). */
- void
- pt_configure_remaining_proxies(void)
- {
- smartlist_t *tmp = smartlist_new();
- log_debug(LD_CONFIG, "Configuring remaining managed proxies (%d)!",
- unconfigured_proxies_n);
- /* Iterate over tmp, not managed_proxy_list, since configure_proxy can
- * remove elements from managed_proxy_list. */
- smartlist_add_all(tmp, managed_proxy_list);
- assert_unconfigured_count_ok();
- SMARTLIST_FOREACH_BEGIN(tmp, managed_proxy_t *, mp) {
- tor_assert(mp->conf_state != PT_PROTO_BROKEN ||
- mp->conf_state != PT_PROTO_FAILED_LAUNCH);
- if (mp->got_hup) {
- mp->got_hup = 0;
- /* This proxy is marked by a SIGHUP. Check whether we need to
- restart it. */
- if (proxy_needs_restart(mp)) {
- log_info(LD_GENERAL, "Preparing managed proxy for restart.");
- proxy_prepare_for_restart(mp);
- } else { /* it doesn't need to be restarted. */
- log_info(LD_GENERAL, "Nothing changed for managed proxy after HUP: "
- "not restarting.");
- }
- continue;
- }
- /* If the proxy is not fully configured, try to configure it
- futher. */
- if (!proxy_configuration_finished(mp))
- configure_proxy(mp);
- } SMARTLIST_FOREACH_END(mp);
- smartlist_free(tmp);
- check_if_restarts_needed = 0;
- assert_unconfigured_count_ok();
- }
- #ifdef _WIN32
- /** Attempt to continue configuring managed proxy <b>mp</b>. */
- static void
- configure_proxy(managed_proxy_t *mp)
- {
- int pos;
- char stdout_buf[200];
- smartlist_t *lines = NULL;
- /* if we haven't launched the proxy yet, do it now */
- if (mp->conf_state == PT_PROTO_INFANT) {
- if (launch_managed_proxy(mp) < 0) { /* launch fail */
- mp->conf_state = PT_PROTO_FAILED_LAUNCH;
- handle_finished_proxy(mp);
- }
- return;
- }
- tor_assert(mp->conf_state != PT_PROTO_INFANT);
- tor_assert(mp->process_handle);
- pos = tor_read_all_handle(tor_process_get_stdout_pipe(mp->process_handle),
- stdout_buf, sizeof(stdout_buf) - 1, NULL);
- if (pos < 0) {
- log_notice(LD_GENERAL, "Failed to read data from managed proxy");
- mp->conf_state = PT_PROTO_BROKEN;
- goto done;
- }
- if (pos == 0) /* proxy has nothing interesting to say. */
- return;
- /* End with a null even if there isn't a \r\n at the end */
- /* TODO: What if this is a partial line? */
- stdout_buf[pos] = '\0';
- /* Split up the buffer */
- lines = smartlist_new();
- tor_split_lines(lines, stdout_buf, pos);
- /* Handle lines. */
- SMARTLIST_FOREACH_BEGIN(lines, const char *, line) {
- handle_proxy_line(line, mp);
- if (proxy_configuration_finished(mp))
- goto done;
- } SMARTLIST_FOREACH_END(line);
- done:
- /* if the proxy finished configuring, exit the loop. */
- if (proxy_configuration_finished(mp))
- handle_finished_proxy(mp);
- if (lines)
- smartlist_free(lines);
- }
- #else /* _WIN32 */
- /** Attempt to continue configuring managed proxy <b>mp</b>. */
- static void
- configure_proxy(managed_proxy_t *mp)
- {
- enum stream_status r;
- char stdout_buf[200];
- /* if we haven't launched the proxy yet, do it now */
- if (mp->conf_state == PT_PROTO_INFANT) {
- if (launch_managed_proxy(mp) < 0) { /* launch fail */
- mp->conf_state = PT_PROTO_FAILED_LAUNCH;
- handle_finished_proxy(mp);
- }
- return;
- }
- tor_assert(mp->conf_state != PT_PROTO_INFANT);
- tor_assert(mp->process_handle);
- while (1) {
- r = get_string_from_pipe(tor_process_get_stdout_pipe(mp->process_handle),
- stdout_buf, sizeof(stdout_buf) - 1);
- if (r == IO_STREAM_OKAY) { /* got a line; handle it! */
- handle_proxy_line((const char *)stdout_buf, mp);
- } else if (r == IO_STREAM_EAGAIN) { /* check back later */
- return;
- } else if (r == IO_STREAM_CLOSED || r == IO_STREAM_TERM) { /* snap! */
- log_notice(LD_GENERAL, "Managed proxy stream closed. "
- "Most probably application stopped running");
- mp->conf_state = PT_PROTO_BROKEN;
- } else { /* unknown stream status */
- log_notice(LD_GENERAL, "Unknown stream status while configuring proxy.");
- }
- /* if the proxy finished configuring, exit the loop. */
- if (proxy_configuration_finished(mp)) {
- handle_finished_proxy(mp);
- return;
- }
- }
- }
- #endif /* _WIN32 */
- /** Register server managed proxy <b>mp</b> transports to state */
- static void
- register_server_proxy(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)
- {
- 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);
- switch (r) {
- case -1:
- log_notice(LD_GENERAL, "Could not add transport %s. Skipping.", t->name);
- transport_free(t);
- 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);
- 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)
- {
- if (mp->is_server)
- register_server_proxy(mp);
- else
- register_client_proxy(mp);
- }
- /** Free memory allocated by managed proxy <b>mp</b>. */
- 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));
- /* free the transports smartlist */
- smartlist_free(mp->transports);
- /* free the transports_to_launch smartlist */
- SMARTLIST_FOREACH(mp->transports_to_launch, char *, t, tor_free(t));
- smartlist_free(mp->transports_to_launch);
- /* remove it from the list of managed proxies */
- smartlist_remove(managed_proxy_list, mp);
- /* free the argv */
- free_execve_args(mp->argv);
- tor_process_handle_destroy(mp->process_handle, also_terminate_process);
- mp->process_handle = NULL;
- tor_free(mp);
- }
- /** Handle a configured or broken managed proxy <b>mp</b>. */
- static void
- handle_finished_proxy(managed_proxy_t *mp)
- {
- switch (mp->conf_state) {
- case PT_PROTO_BROKEN: /* if broken: */
- managed_proxy_destroy(mp, 1); /* annihilate it. */
- break;
- case PT_PROTO_FAILED_LAUNCH: /* if it failed before launching: */
- managed_proxy_destroy(mp, 0); /* destroy it but don't terminate */
- break;
- case PT_PROTO_CONFIGURED: /* if configured correctly: */
- register_proxy(mp); /* register its transports */
- mp->conf_state = PT_PROTO_COMPLETED; /* and mark it as completed. */
- break;
- case PT_PROTO_INFANT:
- case PT_PROTO_LAUNCHED:
- case PT_PROTO_ACCEPTING_METHODS:
- case PT_PROTO_COMPLETED:
- default:
- log_warn(LD_CONFIG, "Unexpected managed proxy state in "
- "handle_finished_proxy().");
- tor_assert(0);
- }
- unconfigured_proxies_n--;
- tor_assert(unconfigured_proxies_n >= 0);
- }
- /** Return true if the configuration of the managed proxy <b>mp</b> is
- finished. */
- static INLINE int
- proxy_configuration_finished(const managed_proxy_t *mp)
- {
- return (mp->conf_state == PT_PROTO_CONFIGURED ||
- mp->conf_state == PT_PROTO_BROKEN ||
- mp->conf_state == PT_PROTO_FAILED_LAUNCH);
- }
- /** This function is called when a proxy sends an {S,C}METHODS DONE message. */
- static void
- handle_methods_done(const managed_proxy_t *mp)
- {
- tor_assert(mp->transports);
- if (smartlist_len(mp->transports) == 0)
- log_notice(LD_GENERAL, "Proxy was spawned successfully, "
- "but it didn't laucn any pluggable transport listeners!");
- log_info(LD_CONFIG, "%s managed proxy configuration completed!",
- mp->is_server ? "Server" : "Client");
- }
- /** Handle a configuration protocol <b>line</b> received from a
- * managed proxy <b>mp</b>. */
- void
- handle_proxy_line(const char *line, managed_proxy_t *mp)
- {
- log_debug(LD_GENERAL, "Got a line from managed proxy: %s", line);
- if (strlen(line) < SMALLEST_MANAGED_LINE_SIZE) {
- log_warn(LD_GENERAL, "Managed proxy configuration line is too small. "
- "Discarding");
- goto err;
- }
- if (!strcmpstart(line, PROTO_ENV_ERROR)) {
- if (mp->conf_state != PT_PROTO_LAUNCHED)
- goto err;
- parse_env_error(line);
- goto err;
- } else if (!strcmpstart(line, PROTO_NEG_FAIL)) {
- if (mp->conf_state != PT_PROTO_LAUNCHED)
- goto err;
- log_warn(LD_CONFIG, "Managed proxy could not pick a "
- "configuration protocol version.");
- goto err;
- } else if (!strcmpstart(line, PROTO_NEG_SUCCESS)) {
- if (mp->conf_state != PT_PROTO_LAUNCHED)
- goto err;
- if (parse_version(line,mp) < 0)
- goto err;
- tor_assert(mp->conf_protocol != 0);
- mp->conf_state = PT_PROTO_ACCEPTING_METHODS;
- return;
- } else if (!strcmpstart(line, PROTO_CMETHODS_DONE)) {
- if (mp->conf_state != PT_PROTO_ACCEPTING_METHODS)
- goto err;
- handle_methods_done(mp);
- mp->conf_state = PT_PROTO_CONFIGURED;
- return;
- } else if (!strcmpstart(line, PROTO_SMETHODS_DONE)) {
- if (mp->conf_state != PT_PROTO_ACCEPTING_METHODS)
- goto err;
- handle_methods_done(mp);
- mp->conf_state = PT_PROTO_CONFIGURED;
- return;
- } else if (!strcmpstart(line, PROTO_CMETHOD_ERROR)) {
- if (mp->conf_state != PT_PROTO_ACCEPTING_METHODS)
- goto err;
- parse_client_method_error(line);
- goto err;
- } else if (!strcmpstart(line, PROTO_SMETHOD_ERROR)) {
- if (mp->conf_state != PT_PROTO_ACCEPTING_METHODS)
- goto err;
- parse_server_method_error(line);
- goto err;
- } else if (!strcmpstart(line, PROTO_CMETHOD)) {
- if (mp->conf_state != PT_PROTO_ACCEPTING_METHODS)
- goto err;
- if (parse_cmethod_line(line, mp) < 0)
- goto err;
- return;
- } else if (!strcmpstart(line, PROTO_SMETHOD)) {
- if (mp->conf_state != PT_PROTO_ACCEPTING_METHODS)
- goto err;
- if (parse_smethod_line(line, mp) < 0)
- goto err;
- return;
- } else if (!strcmpstart(line, SPAWN_ERROR_MESSAGE)) {
- log_warn(LD_GENERAL, "Could not launch managed proxy executable!");
- mp->conf_state = PT_PROTO_FAILED_LAUNCH;
- return;
- }
- log_warn(LD_CONFIG, "Unknown line received by managed proxy. (%s)", line);
- err:
- mp->conf_state = PT_PROTO_BROKEN;
- log_warn(LD_CONFIG, "Managed proxy at '%s' failed the configuration protocol"
- " and will be destroyed.", mp->argv ? mp->argv[0] : "");
- }
- /** Parses an ENV-ERROR <b>line</b> and warns the user accordingly. */
- void
- parse_env_error(const char *line)
- {
- /* (Length of the protocol string) plus (a space) and (the first char of
- the error message) */
- if (strlen(line) < (strlen(PROTO_ENV_ERROR) + 2))
- log_notice(LD_CONFIG, "Managed proxy sent us an %s without an error "
- "message.", PROTO_ENV_ERROR);
- log_warn(LD_CONFIG, "Managed proxy couldn't understand the "
- "pluggable transport environment variables. (%s)",
- line+strlen(PROTO_ENV_ERROR)+1);
- }
- /** Handles a VERSION <b>line</b>. Updates the configuration protocol
- * version in <b>mp</b>. */
- int
- parse_version(const char *line, managed_proxy_t *mp)
- {
- if (strlen(line) < (strlen(PROTO_NEG_SUCCESS) + 2)) {
- log_warn(LD_CONFIG, "Managed proxy sent us malformed %s line.",
- PROTO_NEG_SUCCESS);
- return -1;
- }
- if (strcmp("1", line+strlen(PROTO_NEG_SUCCESS)+1)) { /* hardcoded temp */
- log_warn(LD_CONFIG, "Managed proxy tried to negotiate on version '%s'. "
- "We only support version '1'", line+strlen(PROTO_NEG_SUCCESS)+1);
- return -1;
- }
- mp->conf_protocol = PROTO_VERSION_ONE; /* temp. till more versions appear */
- return 0;
- }
- /** Parses {C,S}METHOD-ERROR <b>line</b> and warns the user
- * accordingly. If <b>is_server</b> it is an SMETHOD-ERROR,
- * otherwise it is a CMETHOD-ERROR. */
- static void
- parse_method_error(const char *line, int is_server)
- {
- const char* error = is_server ?
- PROTO_SMETHOD_ERROR : PROTO_CMETHOD_ERROR;
- /* (Length of the protocol string) plus (a space) and (the first char of
- the error message) */
- if (strlen(line) < (strlen(error) + 2))
- log_warn(LD_CONFIG, "Managed proxy sent us an %s without an error "
- "message.", error);
- log_warn(LD_CONFIG, "%s managed proxy encountered a method error. (%s)",
- is_server ? "Server" : "Client",
- line+strlen(error)+1);
- }
- /** Parses an SMETHOD <b>line</b> and if well-formed it registers the
- * new transport in <b>mp</b>. */
- int
- parse_smethod_line(const char *line, managed_proxy_t *mp)
- {
- int r;
- smartlist_t *items = NULL;
- char *method_name=NULL;
- char *addrport=NULL;
- tor_addr_t addr;
- uint16_t port = 0;
- transport_t *transport=NULL;
- items = smartlist_new();
- smartlist_split_string(items, line, NULL,
- SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
- if (smartlist_len(items) < 3) {
- log_warn(LD_CONFIG, "Server managed proxy sent us a SMETHOD line "
- "with too few arguments.");
- goto err;
- }
- tor_assert(!strcmp(smartlist_get(items,0),PROTO_SMETHOD));
- method_name = smartlist_get(items,1);
- if (!string_is_C_identifier(method_name)) {
- log_warn(LD_CONFIG, "Transport name is not a C identifier (%s).",
- method_name);
- goto err;
- }
- addrport = smartlist_get(items, 2);
- if (tor_addr_port_lookup(addrport, &addr, &port)<0) {
- log_warn(LD_CONFIG, "Error parsing transport "
- "address '%s'", addrport);
- goto err;
- }
- if (!port) {
- log_warn(LD_CONFIG,
- "Transport address '%s' has no port.", addrport);
- goto err;
- }
- transport = transport_new(&addr, port, method_name, PROXY_NONE);
- if (!transport)
- goto err;
- smartlist_add(mp->transports, transport);
- /* For now, notify the user so that he knows where the server
- transport is listening. */
- log_info(LD_CONFIG, "Server transport %s at %s:%d.",
- method_name, fmt_addr(&addr), (int)port);
- r=0;
- goto done;
- err:
- r = -1;
- done:
- SMARTLIST_FOREACH(items, char*, s, tor_free(s));
- smartlist_free(items);
- return r;
- }
- /** Parses a CMETHOD <b>line</b>, and if well-formed it registers
- * the new transport in <b>mp</b>. */
- int
- parse_cmethod_line(const char *line, managed_proxy_t *mp)
- {
- int r;
- smartlist_t *items = NULL;
- char *method_name=NULL;
- char *socks_ver_str=NULL;
- int socks_ver=PROXY_NONE;
- char *addrport=NULL;
- tor_addr_t addr;
- uint16_t port = 0;
- transport_t *transport=NULL;
- items = smartlist_new();
- smartlist_split_string(items, line, NULL,
- SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
- if (smartlist_len(items) < 4) {
- log_warn(LD_CONFIG, "Client managed proxy sent us a CMETHOD line "
- "with too few arguments.");
- goto err;
- }
- tor_assert(!strcmp(smartlist_get(items,0),PROTO_CMETHOD));
- method_name = smartlist_get(items,1);
- if (!string_is_C_identifier(method_name)) {
- log_warn(LD_CONFIG, "Transport name is not a C identifier (%s).",
- method_name);
- goto err;
- }
- socks_ver_str = smartlist_get(items,2);
- if (!strcmp(socks_ver_str,"socks4")) {
- socks_ver = PROXY_SOCKS4;
- } else if (!strcmp(socks_ver_str,"socks5")) {
- socks_ver = PROXY_SOCKS5;
- } else {
- log_warn(LD_CONFIG, "Client managed proxy sent us a proxy protocol "
- "we don't recognize. (%s)", socks_ver_str);
- goto err;
- }
- addrport = smartlist_get(items, 3);
- if (tor_addr_port_lookup(addrport, &addr, &port)<0) {
- log_warn(LD_CONFIG, "Error parsing transport "
- "address '%s'", addrport);
- goto err;
- }
- if (!port) {
- log_warn(LD_CONFIG,
- "Transport address '%s' has no port.", addrport);
- goto err;
- }
- transport = transport_new(&addr, port, method_name, socks_ver);
- if (!transport)
- goto err;
- smartlist_add(mp->transports, transport);
- log_info(LD_CONFIG, "Transport %s at %s:%d with SOCKS %d. "
- "Attached to managed proxy.",
- method_name, fmt_addr(&addr), (int)port, socks_ver);
- r=0;
- goto done;
- err:
- r = -1;
- done:
- SMARTLIST_FOREACH(items, char*, s, tor_free(s));
- smartlist_free(items);
- return r;
- }
- /** Return the string that tor should place in TOR_PT_SERVER_BINDADDR
- * while configuring the server managed proxy in <b>mp</b>. The
- * string is stored in the heap, and it's the the responsibility of
- * the caller to deallocate it after its use. */
- static char *
- get_bindaddr_for_server_proxy(const managed_proxy_t *mp)
- {
- char *bindaddr_result = NULL;
- char *bindaddr_tmp = NULL;
- smartlist_t *string_tmp = smartlist_new();
- tor_assert(mp->is_server);
- SMARTLIST_FOREACH_BEGIN(mp->transports_to_launch, char *, t) {
- bindaddr_tmp = get_stored_bindaddr_for_server_transport(t);
- smartlist_add_asprintf(string_tmp, "%s-%s", t, bindaddr_tmp);
- tor_free(bindaddr_tmp);
- } SMARTLIST_FOREACH_END(t);
- bindaddr_result = smartlist_join_strings(string_tmp, ",", 0, NULL);
- SMARTLIST_FOREACH(string_tmp, char *, t, tor_free(t));
- smartlist_free(string_tmp);
- return bindaddr_result;
- }
- /** Return a newly allocated process_environment_t * for <b>mp</b>'s
- * process. */
- static process_environment_t *
- create_managed_proxy_environment(const managed_proxy_t *mp)
- {
- const or_options_t *options = get_options();
- /* Environment variables to be added to or set in mp's environment. */
- smartlist_t *envs = smartlist_new();
- /* XXXX The next time someone touches this code, shorten the name of
- * set_environment_variable_in_smartlist, add a
- * set_env_var_in_smartlist_asprintf function, and get rid of the
- * silly extra envs smartlist. */
- /* The final environment to be passed to mp. */
- smartlist_t *merged_env_vars = get_current_process_environment_variables();
- process_environment_t *env;
- {
- char *state_tmp = get_datadir_fname("pt_state/"); /* XXX temp */
- smartlist_add_asprintf(envs, "TOR_PT_STATE_LOCATION=%s", state_tmp);
- tor_free(state_tmp);
- }
- smartlist_add(envs, tor_strdup("TOR_PT_MANAGED_TRANSPORT_VER=1"));
- {
- char *transports_to_launch =
- smartlist_join_strings(mp->transports_to_launch, ",", 0, NULL);
- smartlist_add_asprintf(envs,
- mp->is_server ?
- "TOR_PT_SERVER_TRANSPORTS=%s" :
- "TOR_PT_CLIENT_TRANSPORTS=%s",
- transports_to_launch);
- tor_free(transports_to_launch);
- }
- if (mp->is_server) {
- smartlist_add_asprintf(envs, "TOR_PT_ORPORT=127.0.0.1:%s",
- options->ORPort->value);
- {
- char *bindaddr_tmp = get_bindaddr_for_server_proxy(mp);
- smartlist_add_asprintf(envs, "TOR_PT_SERVER_BINDADDR=%s", bindaddr_tmp);
- tor_free(bindaddr_tmp);
- }
- /* XXX023 Remove the '=' here once versions of obfsproxy which
- * assert that this env var exists are sufficiently dead.
- *
- * (If we remove this line entirely, some joker will stick this
- * variable in Tor's environment and crash PTs that try to parse
- * it even when not run in server mode.) */
- smartlist_add(envs, tor_strdup("TOR_PT_EXTENDED_SERVER_PORT="));
- }
- SMARTLIST_FOREACH_BEGIN(envs, const char *, env_var) {
- set_environment_variable_in_smartlist(merged_env_vars, env_var,
- _tor_free, 1);
- } SMARTLIST_FOREACH_END(env_var);
- env = process_environment_make(merged_env_vars);
- smartlist_free(envs);
- SMARTLIST_FOREACH(merged_env_vars, void *, x, tor_free(x));
- smartlist_free(merged_env_vars);
- return env;
- }
- /** Create and return a new managed proxy for <b>transport</b> using
- * <b>proxy_argv</b>. If <b>is_server</b> is true, it's a server
- * managed proxy. */
- static managed_proxy_t *
- managed_proxy_create(const smartlist_t *transport_list,
- char **proxy_argv, int is_server)
- {
- managed_proxy_t *mp = tor_malloc_zero(sizeof(managed_proxy_t));
- mp->conf_state = PT_PROTO_INFANT;
- mp->is_server = is_server;
- mp->argv = proxy_argv;
- mp->transports = smartlist_new();
- mp->transports_to_launch = smartlist_new();
- SMARTLIST_FOREACH(transport_list, const char *, transport,
- add_transport_to_proxy(transport, mp));
- /* register the managed proxy */
- if (!managed_proxy_list)
- managed_proxy_list = smartlist_new();
- smartlist_add(managed_proxy_list, mp);
- unconfigured_proxies_n++;
- assert_unconfigured_count_ok();
- return mp;
- }
- /** Register proxy with <b>proxy_argv</b>, supporting transports in
- * <b>transport_list</b>, to the managed proxy subsystem.
- * If <b>is_server</b> is true, then the proxy is a server proxy. */
- void
- pt_kickstart_proxy(const smartlist_t *transport_list,
- char **proxy_argv, int is_server)
- {
- managed_proxy_t *mp=NULL;
- transport_t *old_transport = NULL;
- mp = get_managed_proxy_by_argv_and_type(proxy_argv, is_server);
- if (!mp) { /* we haven't seen this proxy before */
- managed_proxy_create(transport_list, proxy_argv, is_server);
- } else { /* known proxy. add its transport to its transport list */
- if (mp->got_hup) {
- /* If the managed proxy we found is marked by a SIGHUP, it means
- that it's not useless and should be kept. If it's marked for
- removal, unmark it and increase the unconfigured proxies so
- that we try to restart it if we need to. Afterwards, check if
- a transport_t for 'transport' used to exist before the SIGHUP
- and make sure it doesn't get deleted because we might reuse
- it. */
- if (mp->marked_for_removal) {
- mp->marked_for_removal = 0;
- check_if_restarts_needed = 1;
- }
- SMARTLIST_FOREACH_BEGIN(transport_list, const char *, transport) {
- old_transport = transport_get_by_name(transport);
- if (old_transport)
- old_transport->marked_for_removal = 0;
- } SMARTLIST_FOREACH_END(transport);
- }
- SMARTLIST_FOREACH(transport_list, const char *, transport,
- add_transport_to_proxy(transport, mp));
- free_execve_args(proxy_argv);
- }
- }
- /** Frees the array of pointers in <b>arg</b> used as arguments to
- execve(2). */
- static INLINE void
- free_execve_args(char **arg)
- {
- char **tmp = arg;
- while (*tmp) /* use the fact that the last element of the array is a
- NULL pointer to know when to stop freeing */
- _tor_free(*tmp++);
- tor_free(arg);
- }
- /** Tor will read its config.
- * Prepare the managed proxy list so that proxies not used in the new
- * config will shutdown, and proxies that need to spawn different
- * transports will do so. */
- void
- pt_prepare_proxy_list_for_config_read(void)
- {
- if (!managed_proxy_list)
- return;
- assert_unconfigured_count_ok();
- SMARTLIST_FOREACH_BEGIN(managed_proxy_list, managed_proxy_t *, mp) {
- /* Destroy unconfigured proxies. */
- if (mp->conf_state != PT_PROTO_COMPLETED) {
- SMARTLIST_DEL_CURRENT(managed_proxy_list, mp);
- managed_proxy_destroy(mp, 1);
- unconfigured_proxies_n--;
- continue;
- }
- tor_assert(mp->conf_state == PT_PROTO_COMPLETED);
- mp->marked_for_removal = 1;
- mp->got_hup = 1;
- SMARTLIST_FOREACH(mp->transports_to_launch, char *, t, tor_free(t));
- smartlist_clear(mp->transports_to_launch);
- } SMARTLIST_FOREACH_END(mp);
- assert_unconfigured_count_ok();
- tor_assert(unconfigured_proxies_n == 0);
- }
- /** 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
- * config. */
- void
- sweep_proxy_list(void)
- {
- if (!managed_proxy_list)
- return;
- assert_unconfigured_count_ok();
- SMARTLIST_FOREACH_BEGIN(managed_proxy_list, managed_proxy_t *, mp) {
- if (mp->marked_for_removal) {
- SMARTLIST_DEL_CURRENT(managed_proxy_list, mp);
- managed_proxy_destroy(mp, 1);
- }
- } SMARTLIST_FOREACH_END(mp);
- assert_unconfigured_count_ok();
- }
- /** Release all storage held by the pluggable transports subsystem. */
- void
- pt_free_all(void)
- {
- 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
- free them. Otherwise, it hasn't registered its transports yet
- and we should free them here. */
- SMARTLIST_FOREACH(managed_proxy_list, managed_proxy_t *, mp, {
- SMARTLIST_DEL_CURRENT(managed_proxy_list, mp);
- managed_proxy_destroy(mp, 1);
- });
- smartlist_free(managed_proxy_list);
- managed_proxy_list=NULL;
- }
- }
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