diff options
Diffstat (limited to 'src/or/hs_config.c')
| -rw-r--r-- | src/or/hs_config.c | 590 |
1 files changed, 590 insertions, 0 deletions
diff --git a/src/or/hs_config.c b/src/or/hs_config.c new file mode 100644 index 0000000000..be223503a0 --- /dev/null +++ b/src/or/hs_config.c @@ -0,0 +1,590 @@ +/* Copyright (c) 2017, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file hs_config.c + * \brief Implement hidden service configuration subsystem. + * + * \details + * + * This file has basically one main entry point: hs_config_service_all(). It + * takes the torrc options and configure hidden service from it. In validate + * mode, nothing is added to the global service list or keys are not generated + * nor loaded. + * + * A service is configured in two steps. It is first created using the tor + * options and then put in a staging list. It will stay there until + * hs_service_load_all_keys() is called. That function is responsible to + * load/generate the keys for the service in the staging list and if + * successful, transfert the service to the main global service list where + * at that point it is ready to be used. + * + * Configuration functions are per-version and there is a main generic one for + * every option that is common to all version (config_generic_service). + **/ + +#define HS_CONFIG_PRIVATE + +#include "hs_common.h" +#include "hs_config.h" +#include "hs_service.h" +#include "rendservice.h" + +/* Using the given list of services, stage them into our global state. Every + * service version are handled. This function can remove entries in the given + * service_list. + * + * Staging a service means that we take all services in service_list and we + * put them in the staging list (global) which acts as a temporary list that + * is used by the service loading key process. In other words, staging a + * service puts it in a list to be considered when loading the keys and then + * moved to the main global list. */ +static void +stage_services(smartlist_t *service_list) +{ + tor_assert(service_list); + + /* This is v2 specific. Trigger service pruning which will make sure the + * just configured services end up in the main global list. It should only + * be done in non validation mode because v2 subsystem handles service + * object differently. */ + rend_service_prune_list(); + + /* Cleanup v2 service from the list, we don't need those object anymore + * because we validated them all against the others and we want to stage + * only >= v3 service. And remember, v2 has a different object type which is + * shadow copied from an hs_service_t type. */ + SMARTLIST_FOREACH_BEGIN(service_list, hs_service_t *, s) { + if (s->config.version == HS_VERSION_TWO) { + SMARTLIST_DEL_CURRENT(service_list, s); + hs_service_free(s); + } + } SMARTLIST_FOREACH_END(s); + + /* This is >= v3 specific. Using the newly configured service list, stage + * them into our global state. Every object ownership is lost after. */ + hs_service_stage_services(service_list); +} + +/* Validate the given service against all service in the given list. If the + * service is ephemeral, this function ignores it. Services with the same + * directory path aren't allowed and will return an error. If a duplicate is + * found, 1 is returned else 0 if none found. */ +static int +service_is_duplicate_in_list(const smartlist_t *service_list, + const hs_service_t *service) +{ + int ret = 0; + + tor_assert(service_list); + tor_assert(service); + + /* Ephemeral service don't have a directory configured so no need to check + * for a service in the list having the same path. */ + if (service->config.is_ephemeral) { + goto end; + } + + /* XXX: Validate if we have any service that has the given service dir path. + * This has two problems: + * + * a) It's O(n^2), but the same comment from the bottom of + * rend_config_services() should apply. + * + * b) We only compare directory paths as strings, so we can't + * detect two distinct paths that specify the same directory + * (which can arise from symlinks, case-insensitivity, bind + * mounts, etc.). + * + * It also can't detect that two separate Tor instances are trying + * to use the same HiddenServiceDir; for that, we would need a + * lock file. But this is enough to detect a simple mistake that + * at least one person has actually made. */ + SMARTLIST_FOREACH_BEGIN(service_list, const hs_service_t *, s) { + if (!strcmp(s->config.directory_path, service->config.directory_path)) { + log_warn(LD_REND, "Another hidden service is already configured " + "for directory %s", + escaped(service->config.directory_path)); + ret = 1; + goto end; + } + } SMARTLIST_FOREACH_END(s); + + end: + return ret; +} + +/* Helper function: Given an configuration option name, its value, a minimum + * min and a maxium max, parse the value as a uint64_t. On success, ok is set + * to 1 and ret is the parsed value. On error, ok is set to 0 and ret must be + * ignored. This function logs both on error and success. */ +static uint64_t +helper_parse_uint64(const char *opt, const char *value, uint64_t min, + uint64_t max, int *ok) +{ + uint64_t ret = 0; + + tor_assert(opt); + tor_assert(value); + tor_assert(ok); + + *ok = 0; + ret = tor_parse_uint64(value, 10, min, max, ok, NULL); + if (!*ok) { + log_warn(LD_CONFIG, "%s must be between %" PRIu64 " and %"PRIu64 + ", not %s.", + opt, min, max, value); + goto err; + } + log_info(LD_CONFIG, "%s was parsed to %" PRIu64, opt, ret); + err: + return ret; +} + +/* Return true iff the given options starting at line_ for a hidden service + * contains at least one invalid option. Each hidden service option don't + * apply to all versions so this function can find out. The line_ MUST start + * right after the HiddenServiceDir line of this service. + * + * This is mainly for usability so we can inform the user of any invalid + * option for the hidden service version instead of silently ignoring. */ +static int +config_has_invalid_options(const config_line_t *line_, + const hs_service_t *service) +{ + int ret = 0; + const char **optlist; + const config_line_t *line; + + tor_assert(service); + tor_assert(service->config.version <= HS_VERSION_MAX); + + /* List of options that a v3 service doesn't support thus must exclude from + * its configuration. */ + const char *opts_exclude_v3[] = { + "HiddenServiceAuthorizeClient", + NULL /* End marker. */ + }; + + /* Defining the size explicitly allows us to take advantage of the compiler + * which warns us if we ever bump the max version but forget to grow this + * array. The plus one is because we have a version 0 :). */ + struct { + const char **list; + } exclude_lists[HS_VERSION_MAX + 1] = { + { NULL }, /* v0. */ + { NULL }, /* v1. */ + { NULL }, /* v2 */ + { opts_exclude_v3 }, /* v3. */ + }; + + optlist = exclude_lists[service->config.version].list; + if (optlist == NULL) { + /* No exclude options to look at for this version. */ + goto end; + } + for (int i = 0; optlist[i]; i++) { + const char *opt = optlist[i]; + for (line = line_; line; line = line->next) { + if (!strcasecmp(line->key, "HiddenServiceDir")) { + /* We just hit the next hidden service, stop right now. */ + goto end; + } + if (!strcasecmp(line->key, opt)) { + log_warn(LD_CONFIG, "Hidden service option %s is incompatible with " + "version %" PRIu32 " of service in %s", + opt, service->config.version, + service->config.directory_path); + ret = 1; + /* Continue the loop so we can find all possible options. */ + continue; + } + } + } + end: + return ret; +} + +/* Validate service configuration. This is used when loading the configuration + * and once we've setup a service object, it's config object is passed to this + * function for further validation. This does not validate service key + * material. Return 0 if valid else -1 if invalid. */ +static int +config_validate_service(const hs_service_config_t *config) +{ + tor_assert(config); + + /* Amount of ports validation. */ + if (!config->ports || smartlist_len(config->ports) == 0) { + log_warn(LD_CONFIG, "Hidden service (%s) with no ports configured.", + escaped(config->directory_path)); + goto invalid; + } + + /* Valid. */ + return 0; + invalid: + return -1; +} + +/* Configuration funcion for a version 3 service. The line_ must be pointing + * to the directive directly after a HiddenServiceDir. That way, when hitting + * the next HiddenServiceDir line or reaching the end of the list of lines, we + * know that we have to stop looking for more options. The given service + * object must be already allocated and passed through + * config_generic_service() prior to calling this function. + * + * Return 0 on success else a negative value. */ +static int +config_service_v3(const config_line_t *line_, + hs_service_config_t *config) +{ + int have_num_ip = 0; + const char *dup_opt_seen = NULL; + const config_line_t *line; + + tor_assert(config); + + for (line = line_; line; line = line->next) { + int ok = 0; + if (!strcasecmp(line->key, "HiddenServiceDir")) { + /* We just hit the next hidden service, stop right now. */ + break; + } + /* Number of introduction points. */ + if (!strcasecmp(line->key, "HiddenServiceNumIntroductionPoints")) { + config->num_intro_points = + (unsigned int) helper_parse_uint64(line->key, line->value, + NUM_INTRO_POINTS_DEFAULT, + HS_CONFIG_V3_MAX_INTRO_POINTS, + &ok); + if (!ok || have_num_ip) { + if (have_num_ip) + dup_opt_seen = line->key; + goto err; + } + have_num_ip = 1; + continue; + } + } + + /* We do not load the key material for the service at this stage. This is + * done later once tor can confirm that it is in a running state. */ + + /* We are about to return a fully configured service so do one last pass of + * validation at it. */ + if (config_validate_service(config) < 0) { + goto err; + } + + return 0; + err: + if (dup_opt_seen) { + log_warn(LD_CONFIG, "Duplicate directive %s.", dup_opt_seen); + } + return -1; +} + +/* Configure a service using the given options in line_ and options. This is + * called for any service regardless of its version which means that all + * directives in this function are generic to any service version. This + * function will also check the validity of the service directory path. + * + * The line_ must be pointing to the directive directly after a + * HiddenServiceDir. That way, when hitting the next HiddenServiceDir line or + * reaching the end of the list of lines, we know that we have to stop looking + * for more options. + * + * Return 0 on success else -1. */ +static int +config_generic_service(const config_line_t *line_, + const or_options_t *options, + hs_service_t *service) +{ + int dir_seen = 0; + const config_line_t *line; + hs_service_config_t *config; + /* If this is set, we've seen a duplicate of this option. Keep the string + * so we can log the directive. */ + const char *dup_opt_seen = NULL; + /* These variables will tell us if we ever have duplicate. */ + int have_version = 0, have_allow_unknown_ports = 0; + int have_dir_group_read = 0, have_max_streams = 0; + int have_max_streams_close = 0; + + tor_assert(line_); + tor_assert(options); + tor_assert(service); + + /* Makes thing easier. */ + config = &service->config; + + /* The first line starts with HiddenServiceDir so we consider what's next is + * the configuration of the service. */ + for (line = line_; line ; line = line->next) { + int ok = 0; + + /* This indicate that we have a new service to configure. */ + if (!strcasecmp(line->key, "HiddenServiceDir")) { + /* This function only configures one service at a time so if we've + * already seen one, stop right now. */ + if (dir_seen) { + break; + } + /* Ok, we've seen one and we are about to configure it. */ + dir_seen = 1; + config->directory_path = tor_strdup(line->value); + log_info(LD_CONFIG, "HiddenServiceDir=%s. Configuring...", + escaped(config->directory_path)); + continue; + } + if (BUG(!dir_seen)) { + goto err; + } + /* Version of the service. */ + if (!strcasecmp(line->key, "HiddenServiceVersion")) { + service->config.version = + (uint32_t) helper_parse_uint64(line->key, line->value, HS_VERSION_MIN, + HS_VERSION_MAX, &ok); + if (!ok || have_version) { + if (have_version) + dup_opt_seen = line->key; + goto err; + } + have_version = 1; + continue; + } + /* Virtual port. */ + if (!strcasecmp(line->key, "HiddenServicePort")) { + char *err_msg = NULL; + /* XXX: Can we rename this? */ + rend_service_port_config_t *portcfg = + rend_service_parse_port_config(line->value, " ", &err_msg); + if (!portcfg) { + if (err_msg) { + log_warn(LD_CONFIG, "%s", err_msg); + } + tor_free(err_msg); + goto err; + } + tor_assert(!err_msg); + smartlist_add(config->ports, portcfg); + log_info(LD_CONFIG, "HiddenServicePort=%s for %s", + line->value, escaped(config->directory_path)); + continue; + } + /* Do we allow unknown ports. */ + if (!strcasecmp(line->key, "HiddenServiceAllowUnknownPorts")) { + config->allow_unknown_ports = + (unsigned int) helper_parse_uint64(line->key, line->value, 0, 1, &ok); + if (!ok || have_allow_unknown_ports) { + if (have_allow_unknown_ports) + dup_opt_seen = line->key; + goto err; + } + have_allow_unknown_ports = 1; + continue; + } + /* Directory group readable. */ + if (!strcasecmp(line->key, "HiddenServiceDirGroupReadable")) { + config->dir_group_readable = + (unsigned int) helper_parse_uint64(line->key, line->value, 0, 1, &ok); + if (!ok || have_dir_group_read) { + if (have_dir_group_read) + dup_opt_seen = line->key; + goto err; + } + have_dir_group_read = 1; + continue; + } + /* Maximum streams per circuit. */ + if (!strcasecmp(line->key, "HiddenServiceMaxStreams")) { + config->max_streams_per_rdv_circuit = + helper_parse_uint64(line->key, line->value, 0, + HS_CONFIG_MAX_STREAMS_PER_RDV_CIRCUIT, &ok); + if (!ok || have_max_streams) { + if (have_max_streams) + dup_opt_seen = line->key; + goto err; + } + have_max_streams = 1; + continue; + } + /* Maximum amount of streams before we close the circuit. */ + if (!strcasecmp(line->key, "HiddenServiceMaxStreamsCloseCircuit")) { + config->max_streams_close_circuit = + (unsigned int) helper_parse_uint64(line->key, line->value, 0, 1, &ok); + if (!ok || have_max_streams_close) { + if (have_max_streams_close) + dup_opt_seen = line->key; + goto err; + } + have_max_streams_close = 1; + continue; + } + } + + /* Check if we are configured in non anonymous mode meaning every service + * becomes a single onion service. */ + if (rend_service_non_anonymous_mode_enabled(options)) { + config->is_single_onion = 1; + /* We will add support for IPv6-only v3 single onion services in a future + * Tor version. This won't catch "ReachableAddresses reject *4", but that + * option doesn't work anyway. */ + if (options->ClientUseIPv4 == 0 && config->version == HS_VERSION_THREE) { + log_warn(LD_CONFIG, "IPv6-only v3 single onion services are not " + "supported. Set HiddenServiceSingleHopMode 0 and " + "HiddenServiceNonAnonymousMode 0, or set ClientUseIPv4 1."); + goto err; + } + } + + /* Success */ + return 0; + err: + if (dup_opt_seen) { + log_warn(LD_CONFIG, "Duplicate directive %s.", dup_opt_seen); + } + return -1; +} + +/* Configure a service using the given line and options. This function will + * call the corresponding configuration function for a specific service + * version and validate the service against the other ones. On success, add + * the service to the given list and return 0. On error, nothing is added to + * the list and a negative value is returned. */ +static int +config_service(const config_line_t *line, const or_options_t *options, + smartlist_t *service_list) +{ + int ret; + hs_service_t *service = NULL; + + tor_assert(line); + tor_assert(options); + tor_assert(service_list); + + /* We have a new hidden service. */ + service = hs_service_new(options); + /* We'll configure that service as a generic one and then pass it to a + * specific function according to the configured version number. */ + if (config_generic_service(line, options, service) < 0) { + goto err; + } + tor_assert(service->config.version <= HS_VERSION_MAX); + /* Before we configure the service on a per-version basis, we'll make + * sure that this set of options for a service are valid that is for + * instance an option only for v2 is not used for v3. */ + if (config_has_invalid_options(line->next, service)) { + goto err; + } + /* Check permission on service directory that was just parsed. And this must + * be done regardless of the service version. Do not ask for the directory + * to be created, this is done when the keys are loaded because we could be + * in validation mode right now. */ + if (hs_check_service_private_dir(options->User, + service->config.directory_path, + service->config.dir_group_readable, + 0) < 0) { + goto err; + } + /* Different functions are in charge of specific options for a version. We + * start just after the service directory line so once we hit another + * directory line, the function knows that it has to stop parsing. */ + switch (service->config.version) { + case HS_VERSION_TWO: + ret = rend_config_service(line->next, options, &service->config); + break; + case HS_VERSION_THREE: + ret = config_service_v3(line->next, &service->config); + break; + default: + /* We do validate before if we support the parsed version. */ + tor_assert_nonfatal_unreached(); + goto err; + } + if (ret < 0) { + goto err; + } + /* We'll check if this service can be kept depending on the others + * configured previously. */ + if (service_is_duplicate_in_list(service_list, service)) { + goto err; + } + /* Passes, add it to the given list. */ + smartlist_add(service_list, service); + return 0; + + err: + hs_service_free(service); + return -1; +} + +/* From a set of <b>options</b>, setup every hidden service found. Return 0 on + * success or -1 on failure. If <b>validate_only</b> is set, parse, warn and + * return as normal, but don't actually change the configured services. */ +int +hs_config_service_all(const or_options_t *options, int validate_only) +{ + int dir_option_seen = 0, ret = -1; + const config_line_t *line; + smartlist_t *new_service_list = NULL; + + tor_assert(options); + + /* Newly configured service are put in that list which is then used for + * validation and staging for >= v3. */ + new_service_list = smartlist_new(); + + for (line = options->RendConfigLines; line; line = line->next) { + /* Ignore all directives that aren't the start of a service. */ + if (strcasecmp(line->key, "HiddenServiceDir")) { + if (!dir_option_seen) { + log_warn(LD_CONFIG, "%s with no preceding HiddenServiceDir directive", + line->key); + goto err; + } + continue; + } + /* Flag that we've seen a directory directive and we'll use it to make + * sure that the torrc options ordering is actually valid. */ + dir_option_seen = 1; + + /* Try to configure this service now. On success, it will be added to the + * list and validated against the service in that same list. */ + if (config_service(line, options, new_service_list) < 0) { + goto err; + } + } + + /* In non validation mode, we'll stage those services we just successfully + * configured. Service ownership is transferred from the list to the global + * state. If any service is invalid, it will be removed from the list and + * freed. All versions are handled in that function. */ + if (!validate_only) { + stage_services(new_service_list); + } else { + /* We've just validated that we were able to build a clean working list of + * services. We don't need those objects anymore. */ + SMARTLIST_FOREACH(new_service_list, hs_service_t *, s, + hs_service_free(s)); + /* For the v2 subsystem, the configuration function adds the service + * object to the staging list and it is transferred in the main list + * through the prunning process. In validation mode, we thus have to purge + * the staging list so it's not kept in memory as valid service. */ + rend_service_free_staging_list(); + } + + /* Success. Note that the service list has no ownership of its content. */ + ret = 0; + goto end; + + err: + SMARTLIST_FOREACH(new_service_list, hs_service_t *, s, hs_service_free(s)); + + end: + smartlist_free(new_service_list); + /* Tor main should call the free all function on error. */ + return ret; +} + |