Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
- Copyright (C) 1997 - 2000 Pekka Riikonen
+ Copyright (C) 1997 - 2001 Pekka Riikonen
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
GNU General Public License for more details.
*/
-/*
- * $Id$
- * $Log$
- * Revision 1.8 2000/10/06 08:10:23 priikone
- * Added WHOIS to send multiple replies if multiple nicknames are
- * found.
- * Added MOTD command and [motd] config section and server also sends
- * motd to client on connection now.
- * Fixed TOPIC command some more.
- *
- * Revision 1.7 2000/07/26 07:04:01 priikone
- * Added server_find_by_id, replace_[server/client]_id.
- *
- * Revision 1.6 2000/07/17 11:47:30 priikone
- * Added command lagging support. Added idle counting support.
- *
- * Revision 1.5 2000/07/12 05:59:41 priikone
- * Major rewrite of ID Cache system. Support added for the new
- * ID cache system. Major rewrite of ID List stuff on server. All
- * SilcXXXList's are now called SilcXXXEntry's and they are pointers
- * by default. A lot rewritten ID list functions.
- *
- * Revision 1.4 2000/07/06 07:16:13 priikone
- * Added SilcPublicKey's
- *
- * Revision 1.3 2000/07/05 06:14:01 priikone
- * Global costemic changes.
- *
- * Revision 1.2 2000/07/03 05:52:11 priikone
- * Fixed typo and a bug.
- *
- * Revision 1.1.1.1 2000/06/27 11:36:56 priikone
- * Imported from internal CVS/Added Log headers.
- *
- *
- */
+/* $Id$ */
#include "serverincludes.h"
#include "idlist.h"
+/******************************************************************************
+
+ Common functions
+
+******************************************************************************/
+
+/* This function is used to add keys and stuff to common ID entry data
+ structure. */
+
+void silc_idlist_add_data(void *entry, SilcIDListData idata)
+{
+ SilcIDListData data = (SilcIDListData)entry;
+ data->send_key = idata->send_key;
+ data->receive_key = idata->receive_key;
+ data->hash = idata->hash;
+ data->hmac = idata->hmac;
+ data->hmac_key = idata->hmac_key;
+ data->hmac_key_len = idata->hmac_key_len;
+ data->public_key = idata->public_key;
+ data->last_receive = idata->last_receive;
+ data->last_sent = idata->last_sent;
+ data->registered = idata->registered;
+}
+
+/* Free's all data in the common ID entry data structure. */
+
+void silc_idlist_del_data(void *entry)
+{
+ SilcIDListData idata = (SilcIDListData)entry;
+ if (idata->send_key)
+ silc_cipher_free(idata->send_key);
+ if (idata->receive_key)
+ silc_cipher_free(idata->receive_key);
+ if (idata->hmac)
+ silc_hmac_free(idata->hmac);
+ if (idata->hmac_key) {
+ memset(idata->hmac_key, 0, idata->hmac_key_len);
+ silc_free(idata->hmac_key);
+ }
+ if (idata->public_key)
+ silc_pkcs_public_key_free(idata->public_key);
+}
+
+/* Purges ID cache */
+
+SILC_TASK_CALLBACK_GLOBAL(silc_idlist_purge)
+{
+ SilcIDListPurge i = (SilcIDListPurge)context;
+
+ SILC_LOG_DEBUG(("Start"));
+
+ silc_idcache_purge(i->cache);
+ silc_task_register(i->timeout_queue, 0,
+ silc_idlist_purge,
+ (void *)i, 600, 0,
+ SILC_TASK_TIMEOUT, SILC_TASK_PRI_LOW);
+}
+
/******************************************************************************
Server entry functions
silc_idlist_add_server(SilcIDList id_list,
char *server_name, int server_type,
SilcServerID *id, SilcServerEntry router,
- SilcCipher send_key, SilcCipher receive_key,
- SilcPKCS pkcs, SilcHmac hmac,
- SilcPublicKey public_key, void *connection)
+ void *connection)
{
SilcServerEntry server;
server->server_type = server_type;
server->id = id;
server->router = router;
- server->send_key = send_key;
- server->receive_key = receive_key;
- server->pkcs = pkcs;
- server->hmac = hmac;
- server->public_key = public_key;
server->connection = connection;
- if (!silc_idcache_add(id_list->servers, server->server_name, SILC_ID_SERVER,
- (void *)server->id, (void *)server, TRUE)) {
+ if (!silc_idcache_add(id_list->servers, server->server_name,
+ server->server_name ? strlen(server->server_name) : 0,
+ SILC_ID_SERVER, (void *)server->id,
+ (void *)server, TRUE, FALSE)) {
silc_free(server);
return NULL;
}
/* Finds server by Server ID */
SilcServerEntry
-silc_idlist_find_server_by_id(SilcIDList id_list, SilcServerID *id)
+silc_idlist_find_server_by_id(SilcIDList id_list, SilcServerID *id,
+ SilcIDCacheEntry *ret_entry)
{
SilcIDCacheEntry id_cache = NULL;
SilcServerEntry server;
if (!id)
return NULL;
- SILC_LOG_DEBUG(("Finding server by ID"));
+ SILC_LOG_DEBUG(("Server ID (%s)",
+ silc_id_render(id, SILC_ID_SERVER)));
if (!silc_idcache_find_by_id_one(id_list->servers, (void *)id,
SILC_ID_SERVER, &id_cache))
server = (SilcServerEntry)id_cache->context;
+ if (ret_entry)
+ *ret_entry = id_cache;
+
+ return server;
+}
+
+/* Find server by name */
+
+SilcServerEntry
+silc_idlist_find_server_by_name(SilcIDList id_list, char *name,
+ SilcIDCacheEntry *ret_entry)
+{
+ SilcIDCacheEntry id_cache = NULL;
+ SilcServerEntry server;
+
+ SILC_LOG_DEBUG(("Server by name `%s'", name));
+
+ if (!silc_idcache_find_by_data_one(id_list->servers, name, &id_cache))
+ return NULL;
+
+ server = (SilcServerEntry)id_cache->context;
+
+ if (ret_entry)
+ *ret_entry = id_cache;
+
+ SILC_LOG_DEBUG(("Found"));
+
+ return server;
+}
+
+/* Find server by connection parameters, hostname and port */
+
+SilcServerEntry
+silc_idlist_find_server_by_conn(SilcIDList id_list, char *hostname,
+ int port, SilcIDCacheEntry *ret_entry)
+{
+ SilcIDCacheList list = NULL;
+ SilcIDCacheEntry id_cache = NULL;
+ SilcServerEntry server = NULL;
+ SilcSocketConnection sock;
+
+ SILC_LOG_DEBUG(("Server by hostname %s and port %d", hostname, port));
+
+ if (!silc_idcache_find_by_id(id_list->servers, SILC_ID_CACHE_ANY,
+ SILC_ID_SERVER, &list))
+ return NULL;
+
+ if (!silc_idcache_list_first(list, &id_cache)) {
+ silc_idcache_list_free(list);
+ return NULL;
+ }
+
+ while (id_cache) {
+ server = (SilcServerEntry)id_cache->context;
+ sock = (SilcSocketConnection)server->connection;
+
+ if (sock && ((sock->hostname && !strcmp(sock->hostname, hostname)) ||
+ (sock->ip && !strcmp(sock->ip, hostname)))
+ && sock->port == port)
+ break;
+
+ id_cache = NULL;
+ server = NULL;
+
+ if (!silc_idcache_list_next(list, &id_cache))
+ break;
+ }
+
+ silc_idcache_list_free(list);
+
+ if (ret_entry)
+ *ret_entry = id_cache;
+
+ SILC_LOG_DEBUG(("Found"));
+
return server;
}
server->id = new_id;
id_cache->id = (void *)new_id;
+ SILC_LOG_DEBUG(("Found"));
+
return server;
}
+/* Removes and free's server entry from ID list */
+
+int silc_idlist_del_server(SilcIDList id_list, SilcServerEntry entry)
+{
+ if (entry) {
+ /* Remove from cache */
+ if (entry->id)
+ if (!silc_idcache_del_by_id(id_list->servers, SILC_ID_SERVER,
+ (void *)entry->id))
+ return FALSE;
+
+ /* Free data */
+ if (entry->server_name)
+ silc_free(entry->server_name);
+ if (entry->id)
+ silc_free(entry->id);
+
+ memset(entry, 'F', sizeof(*entry));
+ silc_free(entry);
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
/******************************************************************************
Client entry functions
/* Add new client entry. This adds the client entry to ID cache system
and returns the allocated client entry or NULL on error. This is
- called when new client connection is accepted to the server. */
+ called when new client connection is accepted to the server. If The
+ `router' is provided then the all server routines assume that the client
+ is not directly connected local client but it has router set and is
+ remote. If this is the case then `connection' must be NULL. If, on the
+ other hand, the `connection' is provided then the client is assumed
+ to be directly connected local client and `router' must be NULL. */
SilcClientEntry
-silc_idlist_add_client(SilcIDList id_list, char *nickname, char *username,
+silc_idlist_add_client(SilcIDList id_list, unsigned char *nickname,
+ unsigned int nickname_len, char *username,
char *userinfo, SilcClientID *id,
- SilcServerEntry router,
- SilcCipher send_key, SilcCipher receive_key,
- SilcPKCS pkcs, SilcHmac hmac,
- SilcPublicKey public_key, void *connection)
+ SilcServerEntry router, void *connection)
{
SilcClientEntry client;
client->userinfo = userinfo;
client->id = id;
client->router = router;
- client->send_key = send_key;
- client->receive_key = receive_key;
- client->pkcs = pkcs;
- client->hmac = hmac;
- client->public_key = public_key;
client->connection = connection;
+ silc_list_init(client->channels, struct SilcChannelClientEntryStruct,
+ client_list);
- if (!silc_idcache_add(id_list->clients, client->nickname, SILC_ID_CLIENT,
- (void *)client->id, (void *)client, TRUE)) {
+ if (!silc_idcache_add(id_list->clients, nickname, nickname_len,
+ SILC_ID_CLIENT, (void *)client->id,
+ (void *)client, TRUE, FALSE)) {
silc_free(client);
return NULL;
}
}
/* Free client entry. This free's everything and removes the entry
- from ID cache. */
+ from ID cache. Call silc_idlist_del_data before calling this one. */
-void silc_idlist_del_client(SilcIDList id_list, SilcClientEntry entry)
+int silc_idlist_del_client(SilcIDList id_list, SilcClientEntry entry)
{
if (entry) {
/* Remove from cache */
if (entry->id)
- silc_idcache_del_by_id(id_list->clients, SILC_ID_CLIENT,
- (void *)entry->id);
+ if (!silc_idcache_del_by_id(id_list->clients, SILC_ID_CLIENT,
+ (void *)entry->id))
+ return FALSE;
/* Free data */
if (entry->nickname)
silc_free(entry->userinfo);
if (entry->id)
silc_free(entry->id);
- if (entry->send_key)
- silc_cipher_free(entry->send_key);
- if (entry->receive_key)
- silc_cipher_free(entry->receive_key);
- if (entry->pkcs)
- silc_pkcs_free(entry->pkcs);
- if (entry->public_key)
- silc_pkcs_public_key_free(entry->public_key);
- if (entry->hmac)
- silc_hmac_free(entry->hmac);
+
+ memset(entry, 'F', sizeof(*entry));
+ silc_free(entry);
+
+ return TRUE;
}
+
+ return FALSE;
}
/* Returns all clients matching requested nickname. Number of clients is
returned to `clients_count'. Caller must free the returned table. */
-SilcClientEntry *
-silc_idlist_get_clients_by_nickname(SilcIDList id_list, char *nickname,
- char *server, unsigned int *clients_count)
+int silc_idlist_get_clients_by_nickname(SilcIDList id_list, char *nickname,
+ char *server,
+ SilcClientEntry **clients,
+ unsigned int *clients_count)
{
SilcIDCacheList list = NULL;
SilcIDCacheEntry id_cache = NULL;
- SilcClientEntry *clients;
int i;
+ SILC_LOG_DEBUG(("Start"));
+
if (!silc_idcache_find_by_data(id_list->clients, nickname, &list))
- return NULL;
+ return FALSE;
- clients = silc_calloc(silc_idcache_list_count(list), sizeof(*clients));
+ *clients = silc_realloc(*clients,
+ (silc_idcache_list_count(list) + *clients_count) *
+ sizeof(**clients));
i = 0;
silc_idcache_list_first(list, &id_cache);
- clients[i++] = (SilcClientEntry)id_cache->context;
+ (*clients)[i++] = (SilcClientEntry)id_cache->context;
while (silc_idcache_list_next(list, &id_cache))
- clients[i++] = (SilcClientEntry)id_cache->context;
+ (*clients)[i++] = (SilcClientEntry)id_cache->context;
silc_idcache_list_free(list);
- if (clients_count)
- *clients_count = i;
+ *clients_count += i;
- return clients;
+ return TRUE;
}
-/* Finds client entry by nickname. */
-
-SilcClientEntry
-silc_idlist_find_client_by_nickname(SilcIDList id_list, char *nickname,
- char *server)
+/* Returns all clients matching requested nickname. Number of clients is
+ returned to `clients_count'. Caller must free the returned table. */
+/* XXX This actually checks the data, which can be hash of the nickname
+ but is not if the client is local client. Global client on global
+ list may have hash. Thus, this is not fully reliable function.
+ Instead this should probably check the hash from the list of client ID's. */
+
+int silc_idlist_get_clients_by_hash(SilcIDList id_list, char *nickname,
+ SilcHash md5hash,
+ SilcClientEntry **clients,
+ unsigned int *clients_count)
{
SilcIDCacheList list = NULL;
SilcIDCacheEntry id_cache = NULL;
- SilcClientEntry client = NULL;
-
- SILC_LOG_DEBUG(("Finding client by nickname"));
-
- if (server) {
- if (!silc_idcache_find_by_data(id_list->clients, nickname, &list))
- return NULL;
+ unsigned char hash[32];
+ int i;
-#if 0
- while (silc_idcache_list_next(list, &id_cache)) {
- client = (SilcClientEntry)id_cache->context;
+ SILC_LOG_DEBUG(("Start"));
- if (!strcmp(server, XXX, strlen(server)))
- break;
+ silc_hash_make(md5hash, nickname, strlen(nickname), hash);
- client = NULL;
- }
-#endif
+ if (!silc_idcache_find_by_data(id_list->clients, hash, &list))
+ return FALSE;
- silc_idcache_list_free(list);
+ *clients = silc_realloc(*clients,
+ (silc_idcache_list_count(list) + *clients_count) *
+ sizeof(**clients));
- if (!client)
- return NULL;
- } else {
- if (!silc_idcache_find_by_data_one(id_list->clients, nickname, &id_cache))
- return NULL;
+ i = 0;
+ silc_idcache_list_first(list, &id_cache);
+ (*clients)[i++] = (SilcClientEntry)id_cache->context;
- client = (SilcClientEntry)id_cache->context;
- }
+ while (silc_idcache_list_next(list, &id_cache))
+ (*clients)[i++] = (SilcClientEntry)id_cache->context;
+
+ silc_idcache_list_free(list);
+
+ *clients_count += i;
- return client;
+ return TRUE;
}
/* Finds client by nickname hash. */
SilcClientEntry
silc_idlist_find_client_by_hash(SilcIDList id_list, char *nickname,
- SilcHash md5hash)
+ SilcHash md5hash, SilcIDCacheEntry *ret_entry)
{
SilcIDCacheList list = NULL;
SilcIDCacheEntry id_cache = NULL;
SilcClientEntry client = NULL;
unsigned char hash[32];
- SILC_LOG_DEBUG(("Finding client by hash"));
+ SILC_LOG_DEBUG(("Client by hash"));
silc_hash_make(md5hash, nickname, strlen(nickname), hash);
silc_idcache_list_free(list);
+ if (ret_entry)
+ *ret_entry = id_cache;
+
+ SILC_LOG_DEBUG(("Found"));
+
return client;
}
/* Finds client by Client ID */
SilcClientEntry
-silc_idlist_find_client_by_id(SilcIDList id_list, SilcClientID *id)
+silc_idlist_find_client_by_id(SilcIDList id_list, SilcClientID *id,
+ SilcIDCacheEntry *ret_entry)
{
SilcIDCacheEntry id_cache = NULL;
SilcClientEntry client;
if (!id)
return NULL;
- SILC_LOG_DEBUG(("Finding client by ID"));
+ SILC_LOG_DEBUG(("Client ID (%s)",
+ silc_id_render(id, SILC_ID_CLIENT)));
if (!silc_idcache_find_by_id_one(id_list->clients, (void *)id,
SILC_ID_CLIENT, &id_cache))
client = (SilcClientEntry)id_cache->context;
+ if (ret_entry)
+ *ret_entry = id_cache;
+
+ SILC_LOG_DEBUG(("Found"));
+
return client;
}
client->id = new_id;
id_cache->id = (void *)new_id;
+ /* If the old ID Cache data was the hash value of the old Client ID
+ replace it with the hash of new Client ID */
+ if (id_cache->data && !SILC_ID_COMPARE_HASH(old_id, id_cache->data)) {
+ silc_free(id_cache->data);
+ id_cache->data = silc_calloc(sizeof(new_id->hash), sizeof(unsigned char));
+ memcpy(id_cache->data, new_id->hash, sizeof(new_id->hash));
+ silc_idcache_sort_by_data(id_list->clients);
+ }
+
+ SILC_LOG_DEBUG(("Replaced"));
+
return client;
}
+/* Client cache entry destructor that is called when the cache is purged. */
+
+void silc_idlist_client_destructor(SilcIDCache cache,
+ SilcIDCacheEntry entry)
+{
+ SilcClientEntry client;
+
+ SILC_LOG_DEBUG(("Start"));
+
+ client = (SilcClientEntry)entry->context;
+ if (client) {
+ if (client->nickname)
+ silc_free(client->nickname);
+ if (client->username)
+ silc_free(client->username);
+ if (client->userinfo)
+ silc_free(client->userinfo);
+ if (client->id)
+ silc_free(client->id);
+
+ memset(client, 'F', sizeof(*client));
+ silc_free(client);
+ }
+}
/******************************************************************************
SilcChannelEntry
silc_idlist_add_channel(SilcIDList id_list, char *channel_name, int mode,
SilcChannelID *id, SilcServerEntry router,
- SilcCipher channel_key)
+ SilcCipher channel_key, SilcHmac hmac)
{
SilcChannelEntry channel;
channel->id = id;
channel->router = router;
channel->channel_key = channel_key;
+ channel->hmac = hmac;
+ if (!channel->hmac)
+ if (!silc_hmac_alloc("hmac-sha1-96", NULL, &channel->hmac)) {
+ silc_free(channel);
+ return NULL;
+ }
+
+ silc_list_init(channel->user_list, struct SilcChannelClientEntryStruct,
+ channel_list);
if (!silc_idcache_add(id_list->channels, channel->channel_name,
- SILC_ID_CHANNEL, (void *)channel->id,
- (void *)channel, TRUE)) {
+ channel->channel_name ? strlen(channel->channel_name) :
+ 0, SILC_ID_CHANNEL,
+ (void *)channel->id, (void *)channel, TRUE, FALSE)) {
silc_free(channel);
return NULL;
}
/* Free channel entry. This free's everything. */
-void silc_idlist_del_channel(SilcIDList id_list, SilcChannelEntry entry)
+int silc_idlist_del_channel(SilcIDList id_list, SilcChannelEntry entry)
{
if (entry) {
+ SilcChannelClientEntry chl;
+
/* Remove from cache */
if (entry->id)
- silc_idcache_del_by_id(id_list->channels, SILC_ID_CHANNEL,
- (void *)entry->id);
+ if (!silc_idcache_del_by_id(id_list->channels, SILC_ID_CHANNEL,
+ (void *)entry->id))
+ return FALSE;
/* Free data */
if (entry->channel_name)
memset(entry->key, 0, entry->key_len / 8);
silc_free(entry->key);
}
- memset(entry->iv, 0, sizeof(entry->iv));
+ if (entry->cipher)
+ silc_free(entry->cipher);
+ if (entry->hmac_name)
+ silc_free(entry->hmac_name);
+ if (entry->rekey)
+ silc_free(entry->rekey);
+
+ /* Free all data, free also any reference from the client's channel
+ list since they share the same memory. */
+ silc_list_start(entry->user_list);
+ while ((chl = silc_list_get(entry->user_list)) != SILC_LIST_END) {
+ silc_list_del(chl->client->channels, chl);
+ silc_list_del(entry->user_list, chl);
+ silc_free(chl);
+ }
- if (entry->user_list_count)
- silc_free(entry->user_list);
+ memset(entry, 'F', sizeof(*entry));
+ silc_free(entry);
+ return TRUE;
}
+
+ return FALSE;
}
/* Finds channel by channel name. Channel names are unique and they
are not case-sensitive. */
SilcChannelEntry
-silc_idlist_find_channel_by_name(SilcIDList id_list, char *name)
+silc_idlist_find_channel_by_name(SilcIDList id_list, char *name,
+ SilcIDCacheEntry *ret_entry)
{
SilcIDCacheList list = NULL;
SilcIDCacheEntry id_cache = NULL;
SilcChannelEntry channel;
- SILC_LOG_DEBUG(("Finding channel by name"));
+ SILC_LOG_DEBUG(("Channel by name"));
if (!silc_idcache_find_by_data_loose(id_list->channels, name, &list))
return NULL;
channel = (SilcChannelEntry)id_cache->context;
+ if (ret_entry)
+ *ret_entry = id_cache;
+
silc_idcache_list_free(list);
+ SILC_LOG_DEBUG(("Found"));
+
return channel;
}
/* Finds channel by Channel ID. */
SilcChannelEntry
-silc_idlist_find_channel_by_id(SilcIDList id_list, SilcChannelID *id)
+silc_idlist_find_channel_by_id(SilcIDList id_list, SilcChannelID *id,
+ SilcIDCacheEntry *ret_entry)
{
SilcIDCacheEntry id_cache = NULL;
SilcChannelEntry channel;
if (!id)
return NULL;
- SILC_LOG_DEBUG(("Finding channel by ID"));
+ SILC_LOG_DEBUG(("Channel ID (%s)",
+ silc_id_render(id, SILC_ID_CHANNEL)));
if (!silc_idcache_find_by_id_one(id_list->channels, (void *)id,
SILC_ID_CHANNEL, &id_cache))
channel = (SilcChannelEntry)id_cache->context;
+ if (ret_entry)
+ *ret_entry = id_cache;
+
+ SILC_LOG_DEBUG(("Found"));
+
+ return channel;
+}
+
+/* Replaces old Channel ID with new one. This is done when router forces
+ normal server to change Channel ID. */
+
+SilcChannelEntry
+silc_idlist_replace_channel_id(SilcIDList id_list, SilcChannelID *old_id,
+ SilcChannelID *new_id)
+{
+ SilcIDCacheEntry id_cache = NULL;
+ SilcChannelEntry channel;
+
+ if (!old_id || !new_id)
+ return NULL;
+
+ SILC_LOG_DEBUG(("Replacing Channel ID"));
+
+ if (!silc_idcache_find_by_id_one(id_list->channels, (void *)old_id,
+ SILC_ID_CHANNEL, &id_cache))
+ return NULL;
+
+ channel = (SilcChannelEntry)id_cache->context;
+ silc_free(channel->id);
+ channel->id = new_id;
+ id_cache->id = (void *)new_id;
+
+ SILC_LOG_DEBUG(("Replaced"));
+
return channel;
}
+
+/* Returns channels from the ID list. If the `channel_id' is NULL then
+ all channels are returned. */
+
+SilcChannelEntry *
+silc_idlist_get_channels(SilcIDList id_list, SilcChannelID *channel_id,
+ unsigned int *channels_count)
+{
+ SilcIDCacheList list = NULL;
+ SilcIDCacheEntry id_cache = NULL;
+ SilcChannelEntry *channels;
+ int i;
+
+ SILC_LOG_DEBUG(("Start"));
+
+ if (!silc_idcache_find_by_id(id_list->channels, channel_id ? channel_id :
+ SILC_ID_CACHE_ANY, SILC_ID_CHANNEL, &list))
+ return NULL;
+
+ channels = silc_calloc(silc_idcache_list_count(list), sizeof(*channels));
+
+ i = 0;
+ silc_idcache_list_first(list, &id_cache);
+ channels[i++] = (SilcChannelEntry)id_cache->context;
+
+ while (silc_idcache_list_next(list, &id_cache))
+ channels[i++] = (SilcChannelEntry)id_cache->context;
+
+ silc_idcache_list_free(list);
+
+ if (channels_count)
+ *channels_count = i;
+
+ return channels;
+}
projects / silc.git / blobdiff