1 files changed, 410 insertions, 0 deletions

diff --git a/src/lib-master/master-service-settings-cache.c b/src/lib-master/master-service-settings-cache.c
new file mode 100644
index 0000000..11dd66b
--- /dev/null
+++ b/src/lib-master/master-service-settings-cache.c
@@ -0,0 +1,410 @@
+/* Copyright (c) 2010-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "wildcard-match.h"
+#include "hash.h"
+#include "llist.h"
+#include "settings-parser.h"
+#include "dns-util.h"
+#include "strescape.h"
+#include "master-service-private.h"
+#include "master-service-settings.h"
+#include "master-service-settings-cache.h"
+
+/* we start with just a guess. it's updated later. */
+#define CACHE_INITIAL_ENTRY_POOL_SIZE (1024*16)
+#define CACHE_ADD_ENTRY_POOL_SIZE 1024
+
+struct config_filter {
+	struct config_filter *prev, *next;
+
+	const char *local_name;
+	struct ip_addr local_ip, remote_ip;
+	unsigned int local_bits, remote_bits;
+};
+
+struct settings_entry {
+	struct settings_entry *prev, *next;
+
+	pool_t pool;
+	const char *local_name;
+	struct ip_addr local_ip;
+
+	struct setting_parser_context *parser;
+};
+
+struct master_service_settings_cache {
+	pool_t pool;
+
+	struct master_service *service;
+	const char *module;
+	const char *service_name;
+	size_t max_cache_size;
+
+	/* global settings for this service (after they've been read) */
+	struct setting_parser_context *global_parser;
+
+	/* cache for other settings (local_ip/local_name set) */
+	struct settings_entry *oldest, *newest;
+	/* separate list for entries whose parser=global_parser */
+	struct settings_entry *oldest_global, *newest_global;
+	/* local_name, local_ip => struct settings_entry */
+	HASH_TABLE(char *, struct settings_entry *) local_name_hash;
+	HASH_TABLE(struct ip_addr *, struct settings_entry *) local_ip_hash;
+
+	struct config_filter *filters;
+
+	/* Initial size for new settings entry pools */
+	size_t approx_entry_pool_size;
+	/* number of bytes malloced by cached settings entries
+	   (doesn't count memory used by hash table or global sets) */
+	size_t cache_malloc_size;
+
+	bool done_initial_lookup:1;
+	bool service_uses_local:1;
+	bool service_uses_remote:1;
+};
+
+struct master_service_settings_cache *
+master_service_settings_cache_init(struct master_service *service,
+				   const char *module, const char *service_name)
+{
+	struct master_service_settings_cache *cache;
+	pool_t pool;
+
+	pool = pool_alloconly_create(MEMPOOL_GROWING"master service settings cache",
+				     1024*12);
+	cache = p_new(pool, struct master_service_settings_cache, 1);
+	cache->pool = pool;
+	cache->service = service;
+	cache->module = p_strdup(pool, module);
+	cache->service_name = p_strdup(pool, service_name);
+	cache->max_cache_size = SIZE_MAX;
+	return cache;
+}
+
+int master_service_settings_cache_init_filter(struct master_service_settings_cache *cache)
+{
+	const char *const *filters;
+	const char *error;
+
+	if (cache->filters != NULL)
+		return 0;
+	if (master_service_settings_get_filters(cache->service, &filters, &error) < 0) {
+		i_error("master-service: cannot get filters: %s", error);
+		return -1;
+	}
+
+	/* parse filters */
+	while(*filters != NULL) {
+		const char *const *keys = t_strsplit_tabescaped(*filters);
+		struct config_filter *filter =
+			p_new(cache->pool, struct config_filter, 1);
+		while(*keys != NULL) {
+			if (str_begins(*keys, "local-net=")) {
+				(void)net_parse_range((*keys)+10,
+					&filter->local_ip, &filter->local_bits);
+			} else if (str_begins(*keys, "remote-net=")) {
+				(void)net_parse_range((*keys)+11,
+					&filter->remote_ip, &filter->remote_bits);
+			} else if (str_begins(*keys, "local-name=")) {
+				filter->local_name = p_strdup(cache->pool, (*keys)+11);
+			}
+			keys++;
+		}
+		DLLIST_PREPEND(&cache->filters, filter);
+		filters++;
+	}
+	return 0;
+}
+
+static bool
+match_local_name(const char *local_name,
+		 const char *filter_local_name)
+{
+	/* Handle multiple names separated by spaces in local_name
+	   * Ex: local_name "mail.domain.tld domain.tld mx.domain.tld" { ... } */
+	const char *ptr;
+	while((ptr = strchr(filter_local_name, ' ')) != NULL) {
+		if (dns_match_wildcard(local_name,
+		    t_strdup_until(filter_local_name, ptr)) == 0)
+			return TRUE;
+		filter_local_name = ptr+1;
+	}
+	return dns_match_wildcard(local_name, filter_local_name) == 0;
+}
+
+/* Remove any elements which there is no filter for */
+static void
+master_service_settings_cache_fix_input(struct master_service_settings_cache *cache,
+				        const struct master_service_settings_input *input,
+					struct master_service_settings_input *new_input)
+{
+	bool found_lip, found_rip, found_local_name;
+
+	found_lip = found_rip = found_local_name = FALSE;
+
+	struct config_filter *filter = cache->filters;
+	while(filter != NULL) {
+		if (filter->local_bits > 0 &&
+		    net_is_in_network(&input->local_ip, &filter->local_ip,
+				      filter->local_bits))
+			found_lip = TRUE;
+		if (filter->remote_bits > 0 &&
+		    net_is_in_network(&input->remote_ip, &filter->remote_ip,
+				      filter->remote_bits))
+			found_rip = TRUE;
+		if (input->local_name != NULL && filter->local_name != NULL &&
+		    match_local_name(input->local_name, filter->local_name))
+			found_local_name = TRUE;
+		filter = filter->next;
+	};
+
+	*new_input = *input;
+
+	if (!found_lip)
+		i_zero(&new_input->local_ip);
+	if (!found_rip)
+		i_zero(&new_input->remote_ip);
+	if (!found_local_name)
+		new_input->local_name = NULL;
+}
+
+
+void master_service_settings_cache_deinit(struct master_service_settings_cache **_cache)
+{
+	struct master_service_settings_cache *cache = *_cache;
+	struct settings_entry *entry, *next;
+
+	/* parsers need to be deinitialized, because they reference the pool */
+	for (entry = cache->oldest_global; entry != NULL; entry = next) {
+		next = entry->next;
+		i_assert(entry->parser == cache->global_parser);
+		pool_unref(&entry->pool);
+	}
+	for (entry = cache->oldest; entry != NULL; entry = next) {
+		next = entry->next;
+		i_assert(entry->parser != cache->global_parser);
+		settings_parser_deinit(&entry->parser);
+		pool_unref(&entry->pool);
+	}
+	hash_table_destroy(&cache->local_name_hash);
+	hash_table_destroy(&cache->local_ip_hash);
+	if (cache->global_parser != NULL)
+		settings_parser_deinit(&cache->global_parser);
+	pool_unref(&cache->pool);
+}
+
+static bool
+cache_can_return_global(struct master_service_settings_cache *cache,
+			const struct master_service_settings_input *input)
+{
+	if (cache->service_uses_local) {
+		if (input->local_name != NULL || input->local_ip.family != 0)
+			return FALSE;
+	}
+	if (cache->service_uses_remote) {
+		if (input->remote_ip.family != 0)
+			return FALSE;
+	}
+	return TRUE;
+}
+
+static bool
+cache_find(struct master_service_settings_cache *cache,
+	   const struct master_service_settings_input *input,
+	   const struct setting_parser_context **parser_r)
+{
+	struct settings_entry *entry = NULL;
+
+	if (!cache->done_initial_lookup)
+		return FALSE;
+
+	if (cache_can_return_global(cache, input)) {
+		if (cache->global_parser != NULL) {
+			*parser_r = cache->global_parser;
+			return TRUE;
+		}
+		return FALSE;
+	}
+
+	if (cache->service_uses_remote)
+		return FALSE;
+
+	/* see if we have it already in cache. if local_name is specified,
+	   don't even try to use local_ip (even though we have it), because
+	   there may be different settings specifically for local_name */
+	if (input->local_name != NULL) {
+		if (hash_table_is_created(cache->local_name_hash)) {
+			entry = hash_table_lookup(cache->local_name_hash,
+						  input->local_name);
+		}
+	} else if (hash_table_is_created(cache->local_ip_hash) &&
+		   input->local_ip.family != 0) {
+		entry = hash_table_lookup(cache->local_ip_hash,
+					  &input->local_ip);
+	}
+
+	if (entry != NULL) {
+		if (entry->parser != cache->global_parser) {
+			DLLIST2_REMOVE(&cache->oldest, &cache->newest, entry);
+			DLLIST2_APPEND(&cache->oldest, &cache->newest, entry);
+		}
+		*parser_r = entry->parser;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+static void
+setting_entry_detach(struct master_service_settings_cache *cache,
+		     struct settings_entry *entry)
+{
+	DLLIST2_REMOVE(&cache->oldest, &cache->newest, entry);
+	cache->cache_malloc_size -=
+		pool_alloconly_get_total_alloc_size(entry->pool);
+
+	if (entry->local_name != NULL)
+		hash_table_remove(cache->local_name_hash, entry->local_name);
+	else if (entry->local_ip.family != 0)
+		hash_table_remove(cache->local_ip_hash, &entry->local_ip);
+	settings_parser_deinit(&entry->parser);
+}
+
+static struct setting_parser_context *
+cache_add(struct master_service_settings_cache *cache,
+	  const struct master_service_settings_input *input,
+	  const struct master_service_settings_output *output,
+	  struct setting_parser_context *parser)
+{
+	struct settings_entry *entry;
+	pool_t pool;
+	size_t pool_size;
+	char *entry_local_name;
+
+	if (!output->used_local && !output->used_remote) {
+		/* these are same as global settings */
+		if (cache->global_parser == NULL) {
+			cache->global_parser =
+				settings_parser_dup(parser, cache->pool);
+		}
+	}
+	if (cache->service_uses_remote) {
+		/* for now we don't try to handle caching remote IPs */
+		return parser;
+	}
+
+	if (input->local_name == NULL && input->local_ip.family == 0)
+		return parser;
+
+	if (!output->used_local) {
+		/* use global settings, but add local_ip/host to hash tables
+		   so we'll find them */
+		pool = pool_alloconly_create("settings global entry", 256);
+	} else if (cache->cache_malloc_size >= cache->max_cache_size) {
+		/* free the oldest and reuse its pool */
+		pool = cache->oldest->pool;
+		setting_entry_detach(cache, cache->oldest);
+		p_clear(pool); /* note: frees also entry */
+	} else {
+		pool_size = cache->approx_entry_pool_size != 0 ?
+			cache->approx_entry_pool_size :
+			CACHE_INITIAL_ENTRY_POOL_SIZE;
+		pool = pool_alloconly_create("settings entry", pool_size);
+	}
+	entry = p_new(pool, struct settings_entry, 1);
+	entry->pool = pool;
+	entry_local_name = p_strdup(pool, input->local_name);
+	entry->local_name = entry_local_name;
+	entry->local_ip = input->local_ip;
+	if (!output->used_local) {
+		entry->parser = cache->global_parser;
+		DLLIST2_APPEND(&cache->oldest_global, &cache->newest_global,
+			       entry);
+	} else {
+		entry->parser = settings_parser_dup(parser, entry->pool);
+		DLLIST2_APPEND(&cache->oldest, &cache->newest, entry);
+
+		pool_size = pool_alloconly_get_total_used_size(pool);
+		if (pool_size > cache->approx_entry_pool_size) {
+			cache->approx_entry_pool_size = pool_size +
+				CACHE_ADD_ENTRY_POOL_SIZE;
+		}
+	}
+	cache->cache_malloc_size += pool_alloconly_get_total_alloc_size(pool);
+
+	if (input->local_name != NULL) {
+		if (!hash_table_is_created(cache->local_name_hash)) {
+			hash_table_create(&cache->local_name_hash,
+					  cache->pool, 0, str_hash, strcmp);
+		}
+		i_assert(hash_table_lookup(cache->local_name_hash,
+					   entry_local_name) == NULL);
+		hash_table_insert(cache->local_name_hash,
+				  entry_local_name, entry);
+	} else if (input->local_ip.family != 0) {
+		if (!hash_table_is_created(cache->local_ip_hash)) {
+			hash_table_create(&cache->local_ip_hash, cache->pool, 0,
+					  net_ip_hash, net_ip_cmp);
+		}
+		i_assert(hash_table_lookup(cache->local_ip_hash,
+					   &entry->local_ip) == NULL);
+		hash_table_insert(cache->local_ip_hash,
+				  &entry->local_ip, entry);
+	}
+	return entry->parser;
+}
+
+int master_service_settings_cache_read(struct master_service_settings_cache *cache,
+				       const struct master_service_settings_input *input,
+				       const struct dynamic_settings_parser *dyn_parsers,
+				       const struct setting_parser_context **parser_r,
+				       const char **error_r)
+{
+	struct master_service_settings_output output;
+	struct master_service_settings_input new_input;
+	const struct master_service_settings *set;
+
+	i_assert(null_strcmp(input->module, cache->module) == 0);
+	i_assert(null_strcmp(input->service, cache->service_name) == 0);
+
+	if (cache_find(cache, input, parser_r))
+		return 0;
+
+	new_input = *input;
+	if (cache->filters != NULL) {
+		master_service_settings_cache_fix_input(cache, input, &new_input);
+		if (cache_find(cache, &new_input, parser_r))
+			return 0;
+	}
+
+	if (dyn_parsers != NULL) {
+		settings_parser_dyn_update(cache->pool, &new_input.roots,
+					   dyn_parsers);
+	}
+	if (master_service_settings_read(cache->service, &new_input,
+					 &output, error_r) < 0)
+		return -1;
+
+	if (!cache->done_initial_lookup) {
+		cache->done_initial_lookup = TRUE;
+		cache->service_uses_local = output.service_uses_local;
+		cache->service_uses_remote = output.service_uses_remote;
+
+		set = master_service_settings_get(cache->service);
+		cache->max_cache_size = set->config_cache_size;
+	}
+
+	if (output.used_local && !cache->service_uses_local) {
+		*error_r = "BUG: config unexpectedly returned local settings";
+		return -1;
+	}
+	if (output.used_remote && !cache->service_uses_remote) {
+		*error_r = "BUG: config unexpectedly returned remote settings";
+		return -1;
+	}
+
+	*parser_r = cache_add(cache, &new_input, &output,
+			      cache->service->set_parser);
+	return 0;
+}