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- /* Copyright (c) 2001, Matej Pfajfar.
- * Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2018, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * @file pubsub_check.c
- * @brief Enforce various requirements on a pubsub_builder.
- **/
- #define PUBSUB_PRIVATE
- #include "lib/dispatch/dispatch_naming.h"
- #include "lib/dispatch/msgtypes.h"
- #include "lib/pubsub/pubsub_flags.h"
- #include "lib/pubsub/pubsub_builder_st.h"
- #include "lib/pubsub/pubsub_build.h"
- #include "lib/container/bitarray.h"
- #include "lib/container/smartlist.h"
- #include "lib/log/util_bug.h"
- #include "lib/malloc/malloc.h"
- #include "lib/string/compat_string.h"
- #include <string.h>
- static void pubsub_adjmap_add(pubsub_adjmap_t *map,
- const pubsub_cfg_t *item);
- /**
- * Helper: contruct and return a new pubsub_adjacency_map from <b>cfg</b>.
- * Return NULL on error.
- **/
- static pubsub_adjmap_t *
- pubsub_build_adjacency_map(const pubsub_items_t *cfg)
- {
- pubsub_adjmap_t *map = tor_malloc_zero(sizeof(*map));
- const size_t n_subsystems = get_num_subsys_ids();
- const size_t n_msgs = get_num_message_ids();
- map->n_subsystems = n_subsystems;
- map->n_msgs = n_msgs;
- map->pub_by_subsys = tor_calloc(n_subsystems, sizeof(smartlist_t*));
- map->sub_by_subsys = tor_calloc(n_subsystems, sizeof(smartlist_t*));
- map->pub_by_msg = tor_calloc(n_msgs, sizeof(smartlist_t*));
- map->sub_by_msg = tor_calloc(n_msgs, sizeof(smartlist_t*));
- SMARTLIST_FOREACH_BEGIN(cfg->items, const pubsub_cfg_t *, item) {
- pubsub_adjmap_add(map, item);
- } SMARTLIST_FOREACH_END(item);
- return map;
- }
- /**
- * Helper: add a single pubsub_cfg_t to an adjacency map.
- **/
- static void
- pubsub_adjmap_add(pubsub_adjmap_t *map,
- const pubsub_cfg_t *item)
- {
- smartlist_t **by_subsys;
- smartlist_t **by_msg;
- tor_assert(item->subsys < map->n_subsystems);
- tor_assert(item->msg < map->n_msgs);
- if (item->is_publish) {
- by_subsys = &map->pub_by_subsys[item->subsys];
- by_msg = &map->pub_by_msg[item->msg];
- } else {
- by_subsys = &map->sub_by_subsys[item->subsys];
- by_msg = &map->sub_by_msg[item->msg];
- }
- if (! *by_subsys)
- *by_subsys = smartlist_new();
- if (! *by_msg)
- *by_msg = smartlist_new();
- smartlist_add(*by_subsys, (void*) item);
- smartlist_add(*by_msg, (void *) item);
- }
- /**
- * Release all storage held by m and set m to NULL.
- **/
- #define pubsub_adjmap_free(m) \
- FREE_AND_NULL(pubsub_adjmap_t, pubsub_adjmap_free_, m)
- /**
- * Free every element of an <b>n</b>-element array of smartlists, then
- * free the array itself.
- **/
- static void
- pubsub_adjmap_free_helper(smartlist_t **lsts, size_t n)
- {
- if (!lsts)
- return;
- for (unsigned i = 0; i < n; ++i) {
- smartlist_free(lsts[i]);
- }
- tor_free(lsts);
- }
- /**
- * Release all storage held by <b>map</b>.
- **/
- static void
- pubsub_adjmap_free_(pubsub_adjmap_t *map)
- {
- if (!map)
- return;
- pubsub_adjmap_free_helper(map->pub_by_subsys, map->n_subsystems);
- pubsub_adjmap_free_helper(map->sub_by_subsys, map->n_subsystems);
- pubsub_adjmap_free_helper(map->pub_by_msg, map->n_msgs);
- pubsub_adjmap_free_helper(map->sub_by_msg, map->n_msgs);
- tor_free(map);
- }
- /**
- * Helper: return the length of <b>sl</b>, or 0 if sl is NULL.
- **/
- static int
- smartlist_len_opt(const smartlist_t *sl)
- {
- if (sl)
- return smartlist_len(sl);
- else
- return 0;
- }
- /** Return a pointer to a statically allocated string encoding the
- * dispatcher flags in <b>flags</b>. */
- static const char *
- format_flags(unsigned flags)
- {
- static char buf[32];
- buf[0] = 0;
- if (flags & DISP_FLAG_EXCL) {
- strlcat(buf, " EXCL", sizeof(buf));
- }
- if (flags & DISP_FLAG_STUB) {
- strlcat(buf, " STUB", sizeof(buf));
- }
- return buf[0] ? buf+1 : buf;
- }
- /**
- * Log a message containing a description of <b>cfg</b> at severity, prefixed
- * by the string <b>prefix</b>.
- */
- static void
- pubsub_cfg_dump(const pubsub_cfg_t *cfg, int severity, const char *prefix)
- {
- if (!prefix)
- prefix = 0;
- tor_log(severity, LD_MESG,
- "%s%s %s: %s{%s} on %s (%s) <%u %u %u %u %x> [%s:%d]",
- prefix,
- get_subsys_id_name(cfg->subsys),
- cfg->is_publish ? "PUB" : "SUB",
- get_message_id_name(cfg->msg),
- get_msg_type_id_name(cfg->type),
- get_channel_id_name(cfg->channel),
- format_flags(cfg->flags),
- cfg->subsys, cfg->msg, cfg->type, cfg->channel, cfg->flags,
- cfg->added_by_file, cfg->added_by_line);
- }
- /**
- * Check whether there are any errors or inconsistencies for the message
- * described by <b>msg</b> in <b>map</b>. If there are problems, log about
- * them, and return -1. Otherwise return 0.
- **/
- static int
- lint_message(const pubsub_adjmap_t *map, message_id_t msg)
- {
- /* NOTE: Some of the checks in this function are maybe over-zealous, and we
- * might not want to have them forever. I've marked them with [?] below.
- */
- if (BUG(msg >= map->n_msgs))
- return 0; // LCOV_EXCL_LINE
- const smartlist_t *pub = map->pub_by_msg[msg];
- const smartlist_t *sub = map->sub_by_msg[msg];
- const size_t n_pub = smartlist_len_opt(pub);
- const size_t n_sub = smartlist_len_opt(sub);
- if (n_pub == 0 && n_sub == 0) {
- log_info(LD_MESG, "Nobody is publishing or subscribing to message %u "
- "(%s).",
- msg, get_message_id_name(msg));
- return 0; // No publishers or subscribers: nothing to do.
- }
- /* We'll set this to false if there are any problems. */
- bool ok = true;
- /* First make sure that if there are publishers, there are subscribers. */
- if (n_pub == 0) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) has subscribers, but no publishers.",
- msg, get_message_id_name(msg));
- ok = false;
- } else if (n_sub == 0) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) has publishers, but no subscribers.",
- msg, get_message_id_name(msg));
- ok = false;
- }
- /* The 'all' list has the publishers and the subscribers. */
- smartlist_t *all = smartlist_new();
- if (pub)
- smartlist_add_all(all, pub);
- if (sub)
- smartlist_add_all(all, sub);
- const pubsub_cfg_t *item0 = smartlist_get(all, 0);
- /* Indicates which subsystems we've found publishing/subscribing here. */
- bitarray_t *published_by = bitarray_init_zero((unsigned)map->n_subsystems);
- bitarray_t *subscribed_by = bitarray_init_zero((unsigned)map->n_subsystems);
- bool pub_excl = false, sub_excl = false, chan_same = true, type_same = true;
- /* Make sure that the messages all have the same channel and type;
- * check whether the DISP_FLAG_EXCL flag is used;
- * and if any subsystem is publishing or subscribing to it twice [??].
- */
- SMARTLIST_FOREACH_BEGIN(all, const pubsub_cfg_t *, cfg) {
- if (cfg->channel != item0->channel) {
- chan_same = false;
- }
- if (cfg->type != item0->type) {
- type_same = false;
- }
- if (cfg->flags & DISP_FLAG_EXCL) {
- if (cfg->is_publish)
- pub_excl = true;
- else
- sub_excl = true;
- }
- if (cfg->is_publish) {
- if (bitarray_is_set(published_by, cfg->subsys)) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) is configured to be published by subsystem "
- "%u (%s) more than once.",
- msg, get_message_id_name(msg),
- cfg->subsys, get_subsys_id_name(cfg->subsys));
- ok = false;
- }
- bitarray_set(published_by, cfg->subsys);
- } else {
- if (bitarray_is_set(subscribed_by, cfg->subsys)) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) is configured to be subscribed by subsystem "
- "%u (%s) more than once.",
- msg, get_message_id_name(msg),
- cfg->subsys, get_subsys_id_name(cfg->subsys));
- ok = false;
- }
- bitarray_set(subscribed_by, cfg->subsys);
- }
- } SMARTLIST_FOREACH_END(cfg);
- /* Check whether any subsystem is publishing and subscribing the same
- * message. [??]
- */
- for (unsigned i = 0; i < map->n_subsystems; ++i) {
- if (bitarray_is_set(published_by, i) &&
- bitarray_is_set(subscribed_by, i)) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) is published and subscribed by the same "
- "subsystem %u (%s)",
- msg, get_message_id_name(msg),
- i, get_subsys_id_name(i));
- ok = false;
- }
- }
- if (! chan_same) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) is associated with multiple inconsistent "
- "channels.",
- msg, get_message_id_name(msg));
- ok = false;
- }
- if (! type_same) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) is associated with multiple inconsistent "
- "message types.",
- msg, get_message_id_name(msg));
- ok = false;
- }
- /* Enforce exclusive-ness for publishers and subscribers that have asked for
- * it.
- */
- if (pub_excl && smartlist_len(pub) > 1) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) has multiple publishers, but at least one is "
- "marked as exclusive.",
- msg, get_message_id_name(msg));
- ok = false;
- }
- if (sub_excl && smartlist_len(sub) > 1) {
- log_warn(LD_MESG|LD_BUG,
- "Message %u (%s) has multiple subscribers, but at least one is "
- "marked as exclusive.",
- msg, get_message_id_name(msg));
- ok = false;
- }
- if (!ok) {
- /* There was a problem -- let's log all the publishers and subscribers on
- * this message */
- SMARTLIST_FOREACH(all, pubsub_cfg_t *, cfg,
- pubsub_cfg_dump(cfg, LOG_WARN, " "));
- }
- smartlist_free(all);
- bitarray_free(published_by);
- bitarray_free(subscribed_by);
- return ok ? 0 : -1;
- }
- /**
- * Check all the messages in <b>map</b> for consistency. Return 0 on success,
- * -1 on problems.
- **/
- static int
- pubsub_adjmap_check(const pubsub_adjmap_t *map)
- {
- bool all_ok = true;
- for (unsigned i = 0; i < map->n_msgs; ++i) {
- if (lint_message(map, i) < 0) {
- all_ok = false;
- }
- }
- return all_ok ? 0 : -1;
- }
- /**
- * Check builder for consistency and various constraints. Return 0 on success,
- * -1 on failure.
- **/
- int
- pubsub_builder_check(pubsub_builder_t *builder)
- {
- pubsub_adjmap_t *map = pubsub_build_adjacency_map(builder->items);
- int rv = -1;
- if (!map)
- goto err; // should be impossible
- if (pubsub_adjmap_check(map) < 0)
- goto err;
- rv = 0;
- err:
- pubsub_adjmap_free(map);
- return rv;
- }
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