db.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief ASTdb Management
 *
 * \author Mark Spencer <markster@digium.com> 
 *
 * \note DB3 is licensed under Sleepycat Public License and is thus incompatible
 * with GPL.  To avoid having to make another exception (and complicate 
 * licensing even further) we elect to use DB1 which is BSD licensed 
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 322981 $")

#include "asterisk/_private.h"
#include "asterisk/paths.h"   /* use ast_config_AST_DB */
#include <sys/time.h>
#include <signal.h>
#include <dirent.h>

#include "asterisk/channel.h"
#include "asterisk/file.h"
#include "asterisk/app.h"
#include "asterisk/dsp.h"
#include "asterisk/astdb.h"
#include "asterisk/cli.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/manager.h"
#include "db1-ast/include/db.h"

/*** DOCUMENTATION
   <manager name="DBGet" language="en_US">
      <synopsis>
         Get DB Entry.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="Family" required="true" />
         <parameter name="Key" required="true" />
      </syntax>
      <description>
      </description>
   </manager>
   <manager name="DBPut" language="en_US">
      <synopsis>
         Put DB entry.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="Family" required="true" />
         <parameter name="Key" required="true" />
         <parameter name="Val" />
      </syntax>
      <description>
      </description>
   </manager>
   <manager name="DBDel" language="en_US">
      <synopsis>
         Delete DB entry.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="Family" required="true" />
         <parameter name="Key" required="true" />
      </syntax>
      <description>
      </description>
   </manager>
   <manager name="DBDelTree" language="en_US">
      <synopsis>
         Delete DB Tree.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="Family" required="true" />
         <parameter name="Key" />
      </syntax>
      <description>
      </description>
   </manager>
 ***/

#define MAX_DB_FIELD 256

static DB *astdb;
AST_MUTEX_DEFINE_STATIC(dblock);
static ast_cond_t dbcond;
typedef int (*process_keys_cb)(DBT *key, DBT *value, const char *filter, void *data);

static void db_sync(void);

static int dbinit(void) 
{
   if (!astdb && !(astdb = dbopen(ast_config_AST_DB, O_CREAT | O_RDWR, AST_FILE_MODE, DB_BTREE, NULL))) {
      ast_log(LOG_WARNING, "Unable to open Asterisk database '%s': %s\n", ast_config_AST_DB, strerror(errno));
      return -1;
   }
   return 0;
}


static inline int keymatch(const char *key, const char *prefix)
{
   int preflen = strlen(prefix);
   if (!preflen)
      return 1;
   if (!strcasecmp(key, prefix))
      return 1;
   if ((strlen(key) > preflen) && !strncasecmp(key, prefix, preflen)) {
      if (key[preflen] == '/')
         return 1;
   }
   return 0;
}

static inline int subkeymatch(const char *key, const char *suffix)
{
   int suffixlen = strlen(suffix);
   if (suffixlen) {
      const char *subkey = key + strlen(key) - suffixlen;
      if (subkey < key)
         return 0;
      if (!strcasecmp(subkey, suffix))
         return 1;
   }
   return 0;
}

static const char *dbt_data2str(DBT *dbt)
{
   char *data = "";

   if (dbt->size) {
      data = dbt->data;
      data[dbt->size - 1] = '\0';
   }

   return data;
}

static inline const char *dbt_data2str_full(DBT *dbt, const char *def)
{
   return S_OR(dbt_data2str(dbt), def);
}

static int process_db_keys(process_keys_cb cb, void *data, const char *filter, int sync)
{
   DBT key = { 0, }, value = { 0, }, last_key = { 0, };
   int counter = 0;
   int res, last = 0;
   char last_key_s[MAX_DB_FIELD];

   ast_mutex_lock(&dblock);
   if (dbinit()) {
      ast_mutex_unlock(&dblock);
      return -1;
   }

   /* Somehow, the database can become corrupted such that astdb->seq will continue looping through
    * the database indefinitely. The pointer to last_key.data ends up getting re-used by the BDB lib
    * so this specifically queries for the last entry, makes a copy of the key, and then uses it as
    * a sentinel to avoid repeatedly looping over the list. */

   if (astdb->seq(astdb, &last_key, &value, R_LAST)) {
      /* Empty database */
      ast_mutex_unlock(&dblock);
      return 0;
   }

   memcpy(last_key_s, last_key.data, MIN(last_key.size - 1, sizeof(last_key_s)));
   last_key_s[last_key.size - 1] = '\0';
   for (res = astdb->seq(astdb, &key, &value, R_FIRST);
         !res;
         res = astdb->seq(astdb, &key, &value, R_NEXT)) {
      /* The callback might delete the key, so we have to check it before calling */
      last = !strcmp(dbt_data2str_full(&key, "<bad key>"), last_key_s);
      counter += cb(&key, &value, filter, data);
      if (last) {
         break;
      }
   }

   if (sync) {
      db_sync();
   }

   ast_mutex_unlock(&dblock);

   return counter;
}

static int db_deltree_cb(DBT *key, DBT *value, const char *filter, void *data)
{
   int res = 0;

   if (keymatch(dbt_data2str_full(key, "<bad key>"), filter)) {
      astdb->del(astdb, key, 0);
      res = 1;
   }
   return res;
}

int ast_db_deltree(const char *family, const char *keytree)
{
   char prefix[MAX_DB_FIELD];

   if (family) {
      if (keytree) {
         snprintf(prefix, sizeof(prefix), "/%s/%s", family, keytree);
      } else {
         snprintf(prefix, sizeof(prefix), "/%s", family);
      }
   } else if (keytree) {
      return -1;
   } else {
      prefix[0] = '\0';
   }

   return process_db_keys(db_deltree_cb, NULL, prefix, 1);
}

int ast_db_put(const char *family, const char *keys, const char *value)
{
   char fullkey[MAX_DB_FIELD];
   DBT key, data;
   int res, fullkeylen;

   ast_mutex_lock(&dblock);
   if (dbinit()) {
      ast_mutex_unlock(&dblock);
      return -1;
   }

   fullkeylen = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, keys);
   memset(&key, 0, sizeof(key));
   memset(&data, 0, sizeof(data));
   key.data = fullkey;
   key.size = fullkeylen + 1;
   data.data = (char *) value;
   data.size = strlen(value) + 1;
   res = astdb->put(astdb, &key, &data, 0);
   db_sync();
   ast_mutex_unlock(&dblock);
   if (res)
      ast_log(LOG_WARNING, "Unable to put value '%s' for key '%s' in family '%s'\n", value, keys, family);

   return res;
}

int ast_db_get(const char *family, const char *keys, char *value, int valuelen)
{
   char fullkey[MAX_DB_FIELD] = "";
   DBT key, data;
   int res, fullkeylen;

   ast_mutex_lock(&dblock);
   if (dbinit()) {
      ast_mutex_unlock(&dblock);
      return -1;
   }

   fullkeylen = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, keys);
   memset(&key, 0, sizeof(key));
   memset(&data, 0, sizeof(data));
   memset(value, 0, valuelen);
   key.data = fullkey;
   key.size = fullkeylen + 1;

   res = astdb->get(astdb, &key, &data, 0);

   /* Be sure to NULL terminate our data either way */
   if (res) {
      ast_debug(1, "Unable to find key '%s' in family '%s'\n", keys, family);
   } else {
#if 0
      printf("Got value of size %d\n", data.size);
#endif
      if (data.size) {
         ((char *)data.data)[data.size - 1] = '\0';
         /* Make sure that we don't write too much to the dst pointer or we don't read too much from the source pointer */
         ast_copy_string(value, data.data, (valuelen > data.size) ? data.size : valuelen);
      } else {
         ast_log(LOG_NOTICE, "Strange, empty value for /%s/%s\n", family, keys);
      }
   }

   /* Data is not fully isolated for concurrency, so the lock must be extended
    * to after the copy to the output buffer. */
   ast_mutex_unlock(&dblock);

   return res;
}

int ast_db_del(const char *family, const char *keys)
{
   char fullkey[MAX_DB_FIELD];
   DBT key;
   int res, fullkeylen;

   ast_mutex_lock(&dblock);
   if (dbinit()) {
      ast_mutex_unlock(&dblock);
      return -1;
   }
   
   fullkeylen = snprintf(fullkey, sizeof(fullkey), "/%s/%s", family, keys);
   memset(&key, 0, sizeof(key));
   key.data = fullkey;
   key.size = fullkeylen + 1;
   
   res = astdb->del(astdb, &key, 0);
   db_sync();
   
   ast_mutex_unlock(&dblock);

   if (res) {
      ast_debug(1, "Unable to find key '%s' in family '%s'\n", keys, family);
   }
   return res;
}

static char *handle_cli_database_put(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int res;

   switch (cmd) {
   case CLI_INIT:
      e->command = "database put";
      e->usage =
         "Usage: database put <family> <key> <value>\n"
         "       Adds or updates an entry in the Asterisk database for\n"
         "       a given family, key, and value.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != 5)
      return CLI_SHOWUSAGE;
   res = ast_db_put(a->argv[2], a->argv[3], a->argv[4]);
   if (res)  {
      ast_cli(a->fd, "Failed to update entry\n");
   } else {
      ast_cli(a->fd, "Updated database successfully\n");
   }
   return CLI_SUCCESS;
}

static char *handle_cli_database_get(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int res;
   char tmp[MAX_DB_FIELD];

   switch (cmd) {
   case CLI_INIT:
      e->command = "database get";
      e->usage =
         "Usage: database get <family> <key>\n"
         "       Retrieves an entry in the Asterisk database for a given\n"
         "       family and key.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != 4)
      return CLI_SHOWUSAGE;
   res = ast_db_get(a->argv[2], a->argv[3], tmp, sizeof(tmp));
   if (res) {
      ast_cli(a->fd, "Database entry not found.\n");
   } else {
      ast_cli(a->fd, "Value: %s\n", tmp);
   }
   return CLI_SUCCESS;
}

static char *handle_cli_database_del(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int res;

   switch (cmd) {
   case CLI_INIT:
      e->command = "database del";
      e->usage =
         "Usage: database del <family> <key>\n"
         "       Deletes an entry in the Asterisk database for a given\n"
         "       family and key.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != 4)
      return CLI_SHOWUSAGE;
   res = ast_db_del(a->argv[2], a->argv[3]);
   if (res) {
      ast_cli(a->fd, "Database entry does not exist.\n");
   } else {
      ast_cli(a->fd, "Database entry removed.\n");
   }
   return CLI_SUCCESS;
}

static char *handle_cli_database_deltree(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int res;

   switch (cmd) {
   case CLI_INIT:
      e->command = "database deltree";
      e->usage =
         "Usage: database deltree <family> [keytree]\n"
         "       Deletes a family or specific keytree within a family\n"
         "       in the Asterisk database.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if ((a->argc < 3) || (a->argc > 4))
      return CLI_SHOWUSAGE;
   if (a->argc == 4) {
      res = ast_db_deltree(a->argv[2], a->argv[3]);
   } else {
      res = ast_db_deltree(a->argv[2], NULL);
   }
   if (res < 0) {
      ast_cli(a->fd, "Database entries do not exist.\n");
   } else {
      ast_cli(a->fd, "%d database entries removed.\n",res);
   }
   return CLI_SUCCESS;
}

static int db_show_cb(DBT *key, DBT *value, const char *filter, void *data)
{
   struct ast_cli_args *a = data;
   const char *key_s = dbt_data2str_full(key, "<bad key>");
   const char *value_s = dbt_data2str_full(value, "<bad value>");

   if (keymatch(key_s, filter)) {
      ast_cli(a->fd, "%-50s: %-25s\n", key_s, value_s);
      return 1;
   }

   return 0;
}

static char *handle_cli_database_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char prefix[MAX_DB_FIELD];
   int counter = 0;

   switch (cmd) {
   case CLI_INIT:
      e->command = "database show";
      e->usage =
         "Usage: database show [family [keytree]]\n"
         "       Shows Asterisk database contents, optionally restricted\n"
         "       to a given family, or family and keytree.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc == 4) {
      /* Family and key tree */
      snprintf(prefix, sizeof(prefix), "/%s/%s", a->argv[2], a->argv[3]);
   } else if (a->argc == 3) {
      /* Family only */
      snprintf(prefix, sizeof(prefix), "/%s", a->argv[2]);
   } else if (a->argc == 2) {
      /* Neither */
      prefix[0] = '\0';
   } else {
      return CLI_SHOWUSAGE;
   }

   if((counter = process_db_keys(db_show_cb, a, prefix, 0)) < 0) {
      ast_cli(a->fd, "Database unavailable\n");
      return CLI_SUCCESS;
   }

   ast_cli(a->fd, "%d results found.\n", counter);
   return CLI_SUCCESS;
}

static int db_showkey_cb(DBT *key, DBT *value, const char *filter, void *data)
{
   struct ast_cli_args *a = data;
   const char *key_s = dbt_data2str_full(key, "<bad key>");
   const char *value_s = dbt_data2str_full(value, "<bad value>");

   if (subkeymatch(key_s, filter)) {
      ast_cli(a->fd, "%-50s: %-25s\n", key_s, value_s);
      return 1;
   }

   return 0;
}

static char *handle_cli_database_showkey(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char suffix[MAX_DB_FIELD];
   int counter = 0;

   switch (cmd) {
   case CLI_INIT:
      e->command = "database showkey";
      e->usage =
         "Usage: database showkey <keytree>\n"
         "       Shows Asterisk database contents, restricted to a given key.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc == 3) {
      /* Key only */
      snprintf(suffix, sizeof(suffix), "/%s", a->argv[2]);
   } else {
      return CLI_SHOWUSAGE;
   }

   if ((counter = process_db_keys(db_showkey_cb, a, suffix, 0)) < 0) {
      ast_cli(a->fd, "Database unavailable\n");
      return CLI_SUCCESS;
   }

   ast_cli(a->fd, "%d results found.\n", counter);
   return CLI_SUCCESS;
}

static int db_gettree_cb(DBT *key, DBT *value, const char *filter, void *data)
{
   struct ast_db_entry **ret = data;
   struct ast_db_entry *cur;
   const char *key_s = dbt_data2str_full(key, "<bad key>");
   const char *value_s = dbt_data2str_full(value, "<bad value>");
   size_t key_slen = strlen(key_s) + 1, value_slen = strlen(value_s) + 1;

   if (keymatch(key_s, filter) && (cur = ast_malloc(sizeof(*cur) + key_slen + value_slen))) {
      cur->next = *ret;
      cur->key = cur->data + value_slen;
      strcpy(cur->data, value_s);
      strcpy(cur->key, key_s);
      *ret = cur;
      return 1;
   }

   return 0;
}

struct ast_db_entry *ast_db_gettree(const char *family, const char *keytree)
{
   char prefix[MAX_DB_FIELD];
   struct ast_db_entry *ret = NULL;

   if (!ast_strlen_zero(family)) {
      if (!ast_strlen_zero(keytree)) {
         /* Family and key tree */
         snprintf(prefix, sizeof(prefix), "/%s/%s", family, keytree);
      } else {
         /* Family only */
         snprintf(prefix, sizeof(prefix), "/%s", family);
      }
   } else {
      prefix[0] = '\0';
   }

   if (process_db_keys(db_gettree_cb, &ret, prefix, 0) < 0) {
      ast_log(LOG_WARNING, "Database unavailable\n");
      return NULL;
   }

   return ret;
}

void ast_db_freetree(struct ast_db_entry *dbe)
{
   struct ast_db_entry *last;
   while (dbe) {
      last = dbe;
      dbe = dbe->next;
      ast_free(last);
   }
}

static struct ast_cli_entry cli_database[] = {
   AST_CLI_DEFINE(handle_cli_database_show,    "Shows database contents"),
   AST_CLI_DEFINE(handle_cli_database_showkey, "Shows database contents"),
   AST_CLI_DEFINE(handle_cli_database_get,     "Gets database value"),
   AST_CLI_DEFINE(handle_cli_database_put,     "Adds/updates database value"),
   AST_CLI_DEFINE(handle_cli_database_del,     "Removes database key/value"),
   AST_CLI_DEFINE(handle_cli_database_deltree, "Removes database keytree/values")
};

static int manager_dbput(struct mansession *s, const struct message *m)
{
   const char *family = astman_get_header(m, "Family");
   const char *key = astman_get_header(m, "Key");
   const char *val = astman_get_header(m, "Val");
   int res;

   if (ast_strlen_zero(family)) {
      astman_send_error(s, m, "No family specified");
      return 0;
   }
   if (ast_strlen_zero(key)) {
      astman_send_error(s, m, "No key specified");
      return 0;
   }

   res = ast_db_put(family, key, S_OR(val, ""));
   if (res) {
      astman_send_error(s, m, "Failed to update entry");
   } else {
      astman_send_ack(s, m, "Updated database successfully");
   }
   return 0;
}

static int manager_dbget(struct mansession *s, const struct message *m)
{
   const char *id = astman_get_header(m,"ActionID");
   char idText[256] = "";
   const char *family = astman_get_header(m, "Family");
   const char *key = astman_get_header(m, "Key");
   char tmp[MAX_DB_FIELD];
   int res;

   if (ast_strlen_zero(family)) {
      astman_send_error(s, m, "No family specified.");
      return 0;
   }
   if (ast_strlen_zero(key)) {
      astman_send_error(s, m, "No key specified.");
      return 0;
   }

   if (!ast_strlen_zero(id))
      snprintf(idText, sizeof(idText) ,"ActionID: %s\r\n", id);

   res = ast_db_get(family, key, tmp, sizeof(tmp));
   if (res) {
      astman_send_error(s, m, "Database entry not found");
   } else {
      astman_send_ack(s, m, "Result will follow");
      astman_append(s, "Event: DBGetResponse\r\n"
            "Family: %s\r\n"
            "Key: %s\r\n"
            "Val: %s\r\n"
            "%s"
            "\r\n",
            family, key, tmp, idText);
      astman_append(s, "Event: DBGetComplete\r\n"
            "%s"
            "\r\n",
            idText);
   }
   return 0;
}

static int manager_dbdel(struct mansession *s, const struct message *m)
{
   const char *family = astman_get_header(m, "Family");
   const char *key = astman_get_header(m, "Key");
   int res;

   if (ast_strlen_zero(family)) {
      astman_send_error(s, m, "No family specified.");
      return 0;
   }

   if (ast_strlen_zero(key)) {
      astman_send_error(s, m, "No key specified.");
      return 0;
   }

   res = ast_db_del(family, key);
   if (res)
      astman_send_error(s, m, "Database entry not found");
   else
      astman_send_ack(s, m, "Key deleted successfully");

   return 0;
}

static int manager_dbdeltree(struct mansession *s, const struct message *m)
{
   const char *family = astman_get_header(m, "Family");
   const char *key = astman_get_header(m, "Key");
   int res;

   if (ast_strlen_zero(family)) {
      astman_send_error(s, m, "No family specified.");
      return 0;
   }

   if (!ast_strlen_zero(key))
      res = ast_db_deltree(family, key);
   else
      res = ast_db_deltree(family, NULL);

   if (res < 0)
      astman_send_error(s, m, "Database entry not found");
   else
      astman_send_ack(s, m, "Key tree deleted successfully");
   
   return 0;
}

/*!
 * \internal
 * \brief Signal the astdb sync thread to do its thing.
 *
 * \note dblock is assumed to be held when calling this function.
 */
static void db_sync(void)
{
   ast_cond_signal(&dbcond);
}

/*!
 * \internal
 * \brief astdb sync thread
 *
 * This thread is in charge of syncing astdb to disk after a change.
 * By pushing it off to this thread to take care of, this I/O bound operation
 * will not block other threads from performing other critical processing.
 * If changes happen rapidly, this thread will also ensure that the sync
 * operations are rate limited.
 */
static void *db_sync_thread(void *data)
{
   ast_mutex_lock(&dblock);
   for (;;) {
      ast_cond_wait(&dbcond, &dblock);
      ast_mutex_unlock(&dblock);
      sleep(1);
      ast_mutex_lock(&dblock);
      astdb->sync(astdb, 0);
   }

   return NULL;
}

int astdb_init(void)
{
   pthread_t dont_care;

   ast_cond_init(&dbcond, NULL);
   if (ast_pthread_create_background(&dont_care, NULL, db_sync_thread, NULL)) {
      return -1;
   }

   dbinit();
   ast_cli_register_multiple(cli_database, ARRAY_LEN(cli_database));
   ast_manager_register_xml("DBGet", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, manager_dbget);
   ast_manager_register_xml("DBPut", EVENT_FLAG_SYSTEM, manager_dbput);
   ast_manager_register_xml("DBDel", EVENT_FLAG_SYSTEM, manager_dbdel);
   ast_manager_register_xml("DBDelTree", EVENT_FLAG_SYSTEM, manager_dbdeltree);
   return 0;
}