iax2-provision.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, 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 IAX Provisioning Protocol 
 *
 * \author Mark Spencer <markster@digium.com>
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 373368 $")

#include <netdb.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/socket.h>

#include "asterisk/config.h"
#include "asterisk/cli.h"
#include "asterisk/lock.h"
#include "asterisk/frame.h"
#include "asterisk/md5.h"
#include "asterisk/astdb.h"
#include "asterisk/utils.h"
#include "asterisk/acl.h"
#include "iax2.h"
#include "iax2-provision.h"
#include "iax2-parser.h"

static int provinit = 0;

struct iax_template {
   int dead;
   char name[80];
   char src[80];
   char user[20];
   char pass[20];
   char lang[10];
   unsigned short port;
   unsigned int server;
   unsigned short serverport;
   unsigned int altserver;
   unsigned int flags;
   iax2_format format;
   unsigned int tos;
   AST_LIST_ENTRY(iax_template) list;
};

static AST_LIST_HEAD_NOLOCK_STATIC(templates, iax_template);

AST_MUTEX_DEFINE_STATIC(provlock);

static struct iax_flag {
   char *name;
   int value;
} iax_flags[] = {
   { "register", PROV_FLAG_REGISTER },
   { "secure", PROV_FLAG_SECURE },
   { "heartbeat", PROV_FLAG_HEARTBEAT },
   { "debug", PROV_FLAG_DEBUG },
   { "disablecid", PROV_FLAG_DIS_CALLERID },
   { "disablecw", PROV_FLAG_DIS_CALLWAIT },
   { "disablecidcw", PROV_FLAG_DIS_CIDCW },
   { "disable3way", PROV_FLAG_DIS_THREEWAY },
};

char *iax_provflags2str(char *buf, int buflen, unsigned int flags)
{
   int x;

   if (!buf || buflen < 1)
      return NULL;
   
   buf[0] = '\0';

   for (x = 0; x < ARRAY_LEN(iax_flags); x++) {
      if (flags & iax_flags[x].value){
         strncat(buf, iax_flags[x].name, buflen - strlen(buf) - 1);
         strncat(buf, ",", buflen - strlen(buf) - 1);
      }
   }

   if (!ast_strlen_zero(buf)) 
      buf[strlen(buf) - 1] = '\0';
   else
      strncpy(buf, "none", buflen - 1);

   return buf;
}

static unsigned int iax_str2flags(const char *buf)
{
   int x;
   int len;
   unsigned int flags = 0;
   char *e;
   while(buf && *buf) {
      e = strchr(buf, ',');
      if (e)
         len = e - buf;
      else
         len = 0;
      for (x = 0; x < ARRAY_LEN(iax_flags); x++) {
         if ((len && !strncasecmp(iax_flags[x].name, buf, len)) ||
             (!len && !strcasecmp(iax_flags[x].name, buf))) {
            flags |= iax_flags[x].value;
            break;
         }
      }
      if (e) {
         buf = e + 1;
         while(*buf && (*buf < 33))
            buf++;
      } else
         break;
   }
   return flags;
}

static void iax_template_copy(struct iax_template *dst, struct iax_template *src)
{
   if (!dst || !src) {
      return;
   }

   dst->dead = src->dead;
   ast_copy_string(dst->name, src->name, sizeof(dst->name));
   ast_copy_string(dst->src, src->src, sizeof(dst->src));
   ast_copy_string(dst->user, src->user, sizeof(dst->user));
   ast_copy_string(dst->pass, src->pass, sizeof(dst->pass));
   ast_copy_string(dst->lang, src->lang, sizeof(dst->lang));
   dst->port = src->port;
   dst->server = src->server;
   dst->altserver = src->altserver;
   dst->flags = src->flags;
   dst->format = src->format;
   dst->tos = src->tos;
}

static struct iax_template *iax_template_find(const char *s, int allowdead)
{
   struct iax_template *cur;

   AST_LIST_TRAVERSE(&templates, cur, list) {
      if (!strcasecmp(s, cur->name)) {
         if (!allowdead && cur->dead) {
            cur = NULL;
         }
         break;
      }
   }

   return cur;
}

char *iax_prov_complete_template(const char *line, const char *word, int pos, int state)
{
   struct iax_template *c;
   int which=0;
   char *ret = NULL;
   int wordlen = strlen(word);

   if (pos == 3) {
      ast_mutex_lock(&provlock);
      AST_LIST_TRAVERSE(&templates, c, list) {
         if (!strncasecmp(word, c->name, wordlen) && ++which > state) {
            ret = ast_strdup(c->name);
            break;
         }
      }
      ast_mutex_unlock(&provlock);
   }
   return ret;
}

static unsigned int prov_ver_calc(struct iax_ie_data *provdata)
{
   struct MD5Context md5;
   unsigned int tmp[4];
   MD5Init(&md5);
   MD5Update(&md5, provdata->buf, provdata->pos);
   MD5Final((unsigned char *)tmp, &md5);
   return tmp[0] ^ tmp[1] ^ tmp[2] ^ tmp[3];
}

int iax_provision_build(struct iax_ie_data *provdata, unsigned int *signature, const char *template, int force)
{
   struct iax_template *cur;
   unsigned int sig;
   char tmp[40];
   memset(provdata, 0, sizeof(*provdata));
   ast_mutex_lock(&provlock);
   cur = iax_template_find(template, 1);
   /* If no match, try searching for '*' */
   if (!cur)
      cur = iax_template_find("*", 1);
   if (cur) {
      /* found it -- add information elements as appropriate */
      if (force || strlen(cur->user))
         iax_ie_append_str(provdata, PROV_IE_USER, cur->user);
      if (force || strlen(cur->pass))
         iax_ie_append_str(provdata, PROV_IE_PASS, cur->pass);
      if (force || strlen(cur->lang))
         iax_ie_append_str(provdata, PROV_IE_LANG, cur->lang);
      if (force || cur->port)
         iax_ie_append_short(provdata, PROV_IE_PORTNO, cur->port);
      if (force || cur->server)
         iax_ie_append_int(provdata, PROV_IE_SERVERIP, cur->server);
      if (force || cur->serverport)
         iax_ie_append_short(provdata, PROV_IE_SERVERPORT, cur->serverport);
      if (force || cur->altserver)
         iax_ie_append_int(provdata, PROV_IE_ALTSERVER, cur->altserver);
      if (force || cur->flags)
         iax_ie_append_int(provdata, PROV_IE_FLAGS, cur->flags);
      if (force || cur->format)
         iax_ie_append_int(provdata, PROV_IE_FORMAT, cur->format);
      if (force || cur->tos)
         iax_ie_append_byte(provdata, PROV_IE_TOS, cur->tos);
      
      /* Calculate checksum of message so far */
      sig = prov_ver_calc(provdata);
      if (signature)
         *signature = sig;
      /* Store signature */
      iax_ie_append_int(provdata, PROV_IE_PROVVER, sig);
      /* Cache signature for later verification so we need not recalculate all this */
      snprintf(tmp, sizeof(tmp), "v0x%08x", sig);
      ast_db_put("iax/provisioning/cache", template, tmp);
   } else
      ast_db_put("iax/provisioning/cache", template, "u");
   ast_mutex_unlock(&provlock);
   return cur ? 0 : -1;
}

int iax_provision_version(unsigned int *version, const char *template, int force)
{
   char tmp[80] = "";
   struct iax_ie_data ied;
   int ret=0;
   memset(&ied, 0, sizeof(ied));

   ast_mutex_lock(&provlock);
   if (ast_db_get("iax/provisioning/cache", template, tmp, sizeof(tmp))) {
      ast_log(LOG_ERROR, "ast_db_get failed to retrieve iax/provisioning/cache/%s\n", template);
   }
   if (sscanf(tmp, "v%30x", version) != 1) {
      if (strcmp(tmp, "u")) {
         ret = iax_provision_build(&ied, version, template, force);
         if (ret)
            ast_debug(1, "Unable to create provisioning packet for '%s'\n", template);
      } else
         ret = -1;
   } else
      ast_debug(1, "Retrieved cached version '%s' = '%08x'\n", tmp, *version);
   ast_mutex_unlock(&provlock);
   return ret;
}

static int iax_template_parse(struct iax_template *cur, struct ast_config *cfg, const char *s, const char *def)
{
   struct ast_variable *v;
   int foundportno = 0;
   int foundserverportno = 0;
   int x;
   struct in_addr ia;
   struct hostent *hp;
   struct ast_hostent h;
   struct iax_template *src, tmp;
   const char *t;
   if (def) {
      t = ast_variable_retrieve(cfg, s ,"template");
      src = NULL;
      if (t && strlen(t)) {
         src = iax_template_find(t, 0);
         if (!src)
            ast_log(LOG_WARNING, "Unable to find base template '%s' for creating '%s'.  Trying '%s'\n", t, s, def);
         else
            def = t;
      } 
      if (!src) {
         src = iax_template_find(def, 0);
         if (!src)
            ast_log(LOG_WARNING, "Unable to locate default base template '%s' for creating '%s', omitting.\n", def, s);
      }
      if (!src)
         return -1;
      ast_mutex_lock(&provlock);
      /* Backup old data */
      iax_template_copy(&tmp, cur);
      /* Restore from src */
      iax_template_copy(cur, src);
      /* Restore important headers */
      memcpy(cur->name, tmp.name, sizeof(cur->name));
      cur->dead = tmp.dead;
      ast_mutex_unlock(&provlock);
   }
   if (def)
      ast_copy_string(cur->src, def, sizeof(cur->src));
   else
      cur->src[0] = '\0';
   v = ast_variable_browse(cfg, s);
   while(v) {
      if (!strcasecmp(v->name, "port") || !strcasecmp(v->name, "serverport")) {
         if ((sscanf(v->value, "%5d", &x) == 1) && (x > 0) && (x < 65535)) {
            if (!strcasecmp(v->name, "port")) {
               cur->port = x;
               foundportno = 1;
            } else {
               cur->serverport = x;
               foundserverportno = 1;
            }
         } else
            ast_log(LOG_WARNING, "Ignoring invalid %s '%s' for '%s' at line %d\n", v->name, v->value, s, v->lineno);
      } else if (!strcasecmp(v->name, "server") || !strcasecmp(v->name, "altserver")) {
         hp = ast_gethostbyname(v->value, &h);
         if (hp) {
            memcpy(&ia, hp->h_addr, sizeof(ia));
            if (!strcasecmp(v->name, "server"))
               cur->server = ntohl(ia.s_addr);
            else
               cur->altserver = ntohl(ia.s_addr);
         } else 
            ast_log(LOG_WARNING, "Ignoring invalid %s '%s' for '%s' at line %d\n", v->name, v->value, s, v->lineno);
      } else if (!strcasecmp(v->name, "codec")) {
         struct ast_format tmpfmt;
         if ((ast_getformatbyname(v->value, &tmpfmt)) > 0) {
            cur->format = ast_format_to_old_bitfield(&tmpfmt);
         } else
            ast_log(LOG_WARNING, "Ignoring invalid codec '%s' for '%s' at line %d\n", v->value, s, v->lineno);
      } else if (!strcasecmp(v->name, "tos")) {
         if (ast_str2tos(v->value, &cur->tos))
            ast_log(LOG_WARNING, "Invalid tos value at line %d, refer to QoS documentation\n", v->lineno);
      } else if (!strcasecmp(v->name, "user")) {
         ast_copy_string(cur->user, v->value, sizeof(cur->user));
         if (strcmp(cur->user, v->value))
            ast_log(LOG_WARNING, "Truncating username from '%s' to '%s' for '%s' at line %d\n", v->value, cur->user, s, v->lineno);
      } else if (!strcasecmp(v->name, "pass")) {
         ast_copy_string(cur->pass, v->value, sizeof(cur->pass));
         if (strcmp(cur->pass, v->value))
            ast_log(LOG_WARNING, "Truncating password from '%s' to '%s' for '%s' at line %d\n", v->value, cur->pass, s, v->lineno);
      } else if (!strcasecmp(v->name, "language")) {
         ast_copy_string(cur->lang, v->value, sizeof(cur->lang));
         if (strcmp(cur->lang, v->value))
            ast_log(LOG_WARNING, "Truncating language from '%s' to '%s' for '%s' at line %d\n", v->value, cur->lang, s, v->lineno);
      } else if (!strcasecmp(v->name, "flags")) {
         cur->flags = iax_str2flags(v->value);
      } else if (!strncasecmp(v->name, "flags", 5) && strchr(v->name, '+')) {
         cur->flags |= iax_str2flags(v->value);
      } else if (!strncasecmp(v->name, "flags", 5) && strchr(v->name, '-')) {
         cur->flags &= ~iax_str2flags(v->value);
      } else if (strcasecmp(v->name, "template")) {
         ast_log(LOG_WARNING, "Unknown keyword '%s' in definition of '%s' at line %d\n", v->name, s, v->lineno);
      }
      v = v->next;
   }
   if (!foundportno)
      cur->port = IAX_DEFAULT_PORTNO;
   if (!foundserverportno)
      cur->serverport = IAX_DEFAULT_PORTNO;
   return 0;
}

static int iax_process_template(struct ast_config *cfg, char *s, char *def)
{
   /* Find an already existing one if there */
   struct iax_template *cur;
   int mallocd = 0;

   cur = iax_template_find(s, 1 /* allow dead */);
   if (!cur) {
      mallocd = 1;
      cur = ast_calloc(1, sizeof(*cur));
      if (!cur) {
         ast_log(LOG_WARNING, "Out of memory!\n");
         return -1;
      }
      /* Initialize entry */
      ast_copy_string(cur->name, s, sizeof(cur->name));
      cur->dead = 1;
   }
   if (!iax_template_parse(cur, cfg, s, def))
      cur->dead = 0;

   /* Link if we're mallocd */
   if (mallocd) {
      ast_mutex_lock(&provlock);
      AST_LIST_INSERT_HEAD(&templates, cur, list);
      ast_mutex_unlock(&provlock);
   }
   return 0;
}

static const char *ifthere(const char *s)
{
   if (strlen(s))
      return s;
   else
      return "<unspecified>";
}

static const char *iax_server(unsigned int addr)
{
   struct in_addr ia;
   
   if (!addr)
      return "<unspecified>";
   
   ia.s_addr = htonl(addr);

   return ast_inet_ntoa(ia);
}


static char *iax_show_provisioning(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct iax_template *cur;
   char server[INET_ADDRSTRLEN];
   char alternate[INET_ADDRSTRLEN];
   char flags[80];   /* Has to be big enough for 'flags' too */
   int found = 0;

   switch (cmd) {
   case CLI_INIT:
      e->command = "iax2 show provisioning";
      e->usage =
         "Usage: iax2 show provisioning [template]\n"
         "       Lists all known IAX provisioning templates or a\n"
         "       specific one if specified.\n";
      return NULL;
   case CLI_GENERATE:
      return iax_prov_complete_template(a->line, a->word, a->pos, a->n);
   }

   if ((a->argc != 3) && (a->argc != 4))
      return CLI_SHOWUSAGE;

   ast_mutex_lock(&provlock);
   AST_LIST_TRAVERSE(&templates, cur, list) {
      if ((a->argc == 3) || (!strcasecmp(a->argv[3], cur->name)))  {
         if (found) 
            ast_cli(a->fd, "\n");
         ast_copy_string(server, iax_server(cur->server), sizeof(server));
         ast_copy_string(alternate, iax_server(cur->altserver), sizeof(alternate));
         ast_cli(a->fd, "== %s ==\n", cur->name);
         ast_cli(a->fd, "Base Templ:   %s\n", strlen(cur->src) ? cur->src : "<none>");
         ast_cli(a->fd, "Username:     %s\n", ifthere(cur->user));
         ast_cli(a->fd, "Secret:       %s\n", ifthere(cur->pass));
         ast_cli(a->fd, "Language:     %s\n", ifthere(cur->lang));
         ast_cli(a->fd, "Bind Port:    %d\n", cur->port);
         ast_cli(a->fd, "Server:       %s\n", server);
         ast_cli(a->fd, "Server Port:  %d\n", cur->serverport);
         ast_cli(a->fd, "Alternate:    %s\n", alternate);
         ast_cli(a->fd, "Flags:        %s\n", iax_provflags2str(flags, sizeof(flags), cur->flags));
         ast_cli(a->fd, "Format:       %s\n", iax2_getformatname(cur->format));
         ast_cli(a->fd, "TOS:          0x%x\n", cur->tos);
         found++;
      }
   }
   ast_mutex_unlock(&provlock);
   if (!found) {
      if (a->argc == 3)
         ast_cli(a->fd, "No provisioning templates found\n");
      else
         ast_cli(a->fd, "No provisioning template matching '%s' found\n", a->argv[3]);
   }
   return CLI_SUCCESS;
}

static struct ast_cli_entry cli_iax2_provision[] = {
   AST_CLI_DEFINE(iax_show_provisioning, "Display iax provisioning"),
};

static int iax_provision_init(void)
{
   ast_cli_register_multiple(cli_iax2_provision, sizeof(cli_iax2_provision) / sizeof(struct ast_cli_entry));
   provinit = 1;
   return 0;
}

static void iax_provision_free_templates(int dead)
{
   struct iax_template *cur;

   /* Drop dead or not (depending on dead) entries while locked */
   ast_mutex_lock(&provlock);
   AST_LIST_TRAVERSE_SAFE_BEGIN(&templates, cur, list) {
      if ((dead && cur->dead) || !dead) {
         AST_LIST_REMOVE_CURRENT(list);
         ast_free(cur);
      }
   }
   AST_LIST_TRAVERSE_SAFE_END;
   ast_mutex_unlock(&provlock);
}

int iax_provision_unload(void)
{
   provinit = 0;
   ast_cli_unregister_multiple(cli_iax2_provision, sizeof(cli_iax2_provision) / sizeof(struct ast_cli_entry));
   iax_provision_free_templates(0 /* Remove all templates. */);

   return 0;
}

int iax_provision_reload(int reload)
{
   struct ast_config *cfg;
   struct iax_template *cur;
   char *cat;
   int found = 0;
   struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
   if (!provinit)
      iax_provision_init();
   
   cfg = ast_config_load2("iaxprov.conf", "chan_iax2", config_flags);
   if (cfg != NULL && cfg != CONFIG_STATUS_FILEUNCHANGED && cfg != CONFIG_STATUS_FILEINVALID) {
      /* Mark all as dead.  No need for locking */
      AST_LIST_TRAVERSE(&templates, cur, list) {
         cur->dead = 1;
      }

      /* Load as appropriate */
      cat = ast_category_browse(cfg, NULL);
      while(cat) {
         if (strcasecmp(cat, "general")) {
            iax_process_template(cfg, cat, found ? "default" : NULL);
            found++;
            ast_verb(3, "Loaded provisioning template '%s'\n", cat);
         }
         cat = ast_category_browse(cfg, cat);
      }
      ast_config_destroy(cfg);
   } else if (cfg == CONFIG_STATUS_FILEUNCHANGED)
      return 0;
   else
      ast_log(LOG_NOTICE, "No IAX provisioning configuration found, IAX provisioning disabled.\n");

   iax_provision_free_templates(1 /* remove only marked as dead */);

   /* Purge cached signature DB entries */
   ast_db_deltree("iax/provisioning/cache", NULL);
   return 0;
}