Asterisk.org: Developer Documentation (28 Oct 2009)

Wed Oct 28 15:47:54 2009

## Asterisk developer's documentation

# iax2-provision.c

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    00001 /*
    00002  * Asterisk -- An open source telephony toolkit.
    00003  *
    00004  * Copyright (C) 1999 - 2005, Digium, Inc.
    00005  *
    00006  * Mark Spencer <markster@digium.com>
    00007  *
    00008  * See http://www.asterisk.org for more information about
    00009  * the Asterisk project. Please do not directly contact
    00010  * any of the maintainers of this project for assistance;
    00011  * the project provides a web site, mailing lists and IRC
    00012  * channels for your use.
    00013  *
    00014  * This program is free software, distributed under the terms of
    00015  * the GNU General Public License Version 2. See the LICENSE file
    00016  * at the top of the source tree.
    00017  */
    00018
    00019 /*! \file
    00020  * \brief IAX Provisioning Protocol
    00021  *
    00022  */
    00023
    00024 #include <unistd.h>
    00025 #include <stdlib.h>
    00026 #include <string.h>
    00027 #include <stdio.h>
    00028 #include <netdb.h>
    00029 #include <netinet/in.h>
    00030 #include <netinet/in_systm.h>
    00031 #include <netinet/ip.h>
    00032 #include <sys/socket.h>
    00033
    00034 #include "asterisk.h"
    00035
    00036 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 211526 $")
    00037
    00038 #include "asterisk/config.h"
    00039 #include "asterisk/logger.h"
    00040 #include "asterisk/cli.h"
    00041 #include "asterisk/lock.h"
    00042 #include "asterisk/frame.h"
    00043 #include "asterisk/options.h"
    00044 #include "asterisk/md5.h"
    00045 #include "asterisk/astdb.h"
    00046 #include "asterisk/utils.h"
    00047 #include "iax2.h"
    00048 #include "iax2-provision.h"
    00049 #include "iax2-parser.h"
    00050
    00051 #ifndef IPTOS_MINCOST
    00052 #define IPTOS_MINCOST 0x02
    00053 #endif
    00054
    00055 static int provinit = 0;
    00056
    00057 struct iax_template {
    00058    int dead;
    00059    char name[80];
    00060    char src[80];
    00061    struct iax_template *next;
    00062    char user[20];
    00063    char pass[20];
    00064    char lang[10];
    00065    unsigned short port;
    00066    unsigned int server;
    00067    unsigned short serverport;
    00068    unsigned int altserver;
    00069    unsigned int flags;
    00070    unsigned int format;
    00071    int tos;
    00072 } *templates;
    00073
    00074 static struct iax_flag {
    00075    char *name;
    00076    int value;
    00077 } iax_flags[] = {
    00078    { "register", PROV_FLAG_REGISTER },
    00079    { "secure", PROV_FLAG_SECURE },
    00080    { "heartbeat", PROV_FLAG_HEARTBEAT },
    00081    { "debug", PROV_FLAG_DEBUG },
    00082    { "disablecid", PROV_FLAG_DIS_CALLERID },
    00083    { "disablecw", PROV_FLAG_DIS_CALLWAIT },
    00084    { "disablecidcw", PROV_FLAG_DIS_CIDCW },
    00085    { "disable3way", PROV_FLAG_DIS_THREEWAY },
    00086 };
    00087
    00088 char *iax_provflags2str(char *buf, int buflen, unsigned int flags)
    00089 {
    00090    int x;
    00091    if (!buf || buflen < 1) {
    00092       return(NULL);
    00093    }
    00094    buf[0] = '\0';
    00095    for (x=0;x<sizeof(iax_flags) / sizeof(iax_flags[0]); x++) {
    00096       if (flags & iax_flags[x].value){
    00097          strncat(buf, iax_flags[x].name, buflen - strlen(buf) - 1);
    00098          strncat(buf, ",", buflen - strlen(buf) - 1);
    00099       }
    00100    }
    00101    if (strlen(buf))
    00102       buf[strlen(buf) - 1] = '\0';
    00103    else
    00104       strncpy(buf, "none", buflen - 1);
    00105    return buf;
    00106 }
    00107
    00108 static unsigned int iax_str2flags(const char *buf)
    00109 {
    00110    int x;
    00111    int len;
    00112    int found;
    00113    unsigned int flags = 0;
    00114    char *e;
    00115    while(buf && *buf) {
    00116       e = strchr(buf, ',');
    00117       if (e)
    00118          len = e - buf;
    00119       else
    00120          len = 0;
    00121       found = 0;
    00122       for (x=0;x<sizeof(iax_flags) / sizeof(iax_flags[0]); x++) {
    00123          if ((len && !strncasecmp(iax_flags[x].name, buf, len)) ||
    00124              (!len && !strcasecmp(iax_flags[x].name, buf))) {
    00125             flags |= iax_flags[x].value;
    00126             break;
    00127          }
    00128       }
    00129       if (e) {
    00130          buf = e + 1;
    00131          while(*buf && (*buf < 33))
    00132             buf++;
    00133       } else
    00134          break;
    00135    }
    00136    return flags;
    00137 }
    00138 AST_MUTEX_DEFINE_STATIC(provlock);
    00139
    00140 static struct iax_template *iax_template_find(const char *s, int allowdead)
    00141 {
    00142    struct iax_template *cur;
    00143    cur = templates;
    00144    while(cur) {
    00145       if (!strcasecmp(s, cur->name)) {
    00146          if (!allowdead && cur->dead)
    00147             cur = NULL;
    00148          break;
    00149       }
    00150       cur = cur->next;
    00151    }
    00152    return cur;
    00153 }
    00154
    00155 char *iax_prov_complete_template(char *line, char *word, int pos, int state)
    00156 {
    00157    struct iax_template *c;
    00158    int which=0;
    00159    char *ret;
    00160    ast_mutex_lock(&provlock);
    00161    c = templates;
    00162    while(c) {
    00163       if (!strncasecmp(word, c->name, strlen(word))) {
    00164          if (++which > state)
    00165             break;
    00166       }
    00167       c = c->next;
    00168    }
    00169    if (c) {
    00170       ret = strdup(c->name);
    00171    } else
    00172       ret = NULL;
    00173    ast_mutex_unlock(&provlock);
    00174    return ret;
    00175 }
    00176
    00177 static unsigned int prov_ver_calc(struct iax_ie_data *provdata)
    00178 {
    00179    struct MD5Context md5;
    00180    unsigned int tmp[4];
    00181    MD5Init(&md5);
    00182    MD5Update(&md5, provdata->buf, provdata->pos);
    00183    MD5Final((unsigned char *)tmp, &md5);
    00184    return tmp[0] ^ tmp[1] ^ tmp[2] ^ tmp[3];
    00185 }
    00186
    00187 int iax_provision_build(struct iax_ie_data *provdata, unsigned int *signature, const char *template, int force)
    00188 {
    00189    struct iax_template *cur;
    00190    unsigned int sig;
    00191    char tmp[40];
    00192    memset(provdata, 0, sizeof(*provdata));
    00193    ast_mutex_lock(&provlock);
    00194    cur = iax_template_find(template, 1);
    00195    /* If no match, try searching for '*' */
    00196    if (!cur)
    00197       cur = iax_template_find("*", 1);
    00198    if (cur) {
    00199       /* found it -- add information elements as appropriate */
    00200       if (force || strlen(cur->user))
    00201          iax_ie_append_str(provdata, PROV_IE_USER, cur->user);
    00202       if (force || strlen(cur->pass))
    00203          iax_ie_append_str(provdata, PROV_IE_PASS, cur->pass);
    00204       if (force || strlen(cur->lang))
    00205          iax_ie_append_str(provdata, PROV_IE_LANG, cur->lang);
    00206       if (force || cur->port)
    00207          iax_ie_append_short(provdata, PROV_IE_PORTNO, cur->port);
    00208       if (force || cur->server)
    00209          iax_ie_append_int(provdata, PROV_IE_SERVERIP, cur->server);
    00210       if (force || cur->serverport)
    00211          iax_ie_append_short(provdata, PROV_IE_SERVERPORT, cur->serverport);
    00212       if (force || cur->altserver)
    00213          iax_ie_append_int(provdata, PROV_IE_ALTSERVER, cur->altserver);
    00214       if (force || cur->flags)
    00215          iax_ie_append_int(provdata, PROV_IE_FLAGS, cur->flags);
    00216       if (force || cur->format)
    00217          iax_ie_append_int(provdata, PROV_IE_FORMAT, cur->format);
    00218       if (force || cur->tos)
    00219          iax_ie_append_byte(provdata, PROV_IE_TOS, cur->tos);
    00220
    00221       /* Calculate checksum of message so far */
    00222       sig = prov_ver_calc(provdata);
    00223       if (signature)
    00224          *signature = sig;
    00225       /* Store signature */
    00226       iax_ie_append_int(provdata, PROV_IE_PROVVER, sig);
    00227       /* Cache signature for later verification so we need not recalculate all this */
    00228       snprintf(tmp, sizeof(tmp), "v0x%08x", sig);
    00229       ast_db_put("iax/provisioning/cache", template, tmp);
    00230    } else
    00231       ast_db_put("iax/provisioning/cache", template, "u");
    00232    ast_mutex_unlock(&provlock);
    00233    return cur ? 0 : -1;
    00234 }
    00235
    00236 int iax_provision_version(unsigned int *version, const char *template, int force)
    00237 {
    00238    char tmp[80] = "";
    00239    struct iax_ie_data ied;
    00240    int ret=0;
    00241    memset(&ied, 0, sizeof(ied));
    00242
    00243    ast_mutex_lock(&provlock);
    00244    ast_db_get("iax/provisioning/cache", template, tmp, sizeof(tmp));
    00245    if (sscanf(tmp, "v%30x", version) != 1) {
    00246       if (strcmp(tmp, "u")) {
    00247          ret = iax_provision_build(&ied, version, template, force);
    00248          if (ret)
    00249             ast_log(LOG_DEBUG, "Unable to create provisioning packet for '%s'\n", template);
    00250       } else
    00251          ret = -1;
    00252    } else if (option_debug)
    00253       ast_log(LOG_DEBUG, "Retrieved cached version '%s' = '%08x'\n", tmp, *version);
    00254    ast_mutex_unlock(&provlock);
    00255    return ret;
    00256 }
    00257
    00258 static int iax_template_parse(struct iax_template *cur, struct ast_config *cfg, char *s, char *def)
    00259 {
    00260    struct ast_variable *v;
    00261    int foundportno = 0;
    00262    int foundserverportno = 0;
    00263    int x;
    00264    struct in_addr ia;
    00265    struct hostent *hp;
    00266    struct ast_hostent h;
    00267    struct iax_template *src, tmp;
    00268    char *t;
    00269    if (def) {
    00270       t = ast_variable_retrieve(cfg, s ,"template");
    00271       src = NULL;
    00272       if (t && strlen(t)) {
    00273          src = iax_template_find(t, 0);
    00274          if (!src)
    00275             ast_log(LOG_WARNING, "Unable to find base template '%s' for creating '%s'.  Trying '%s'\n", t, s, def);
    00276          else
    00277             def = t;
    00278       }
    00279       if (!src) {
    00280          src = iax_template_find(def, 0);
    00281          if (!src)
    00282             ast_log(LOG_WARNING, "Unable to locate default base template '%s' for creating '%s', omitting.\n", def, s);
    00283       }
    00284       if (!src)
    00285          return -1;
    00286       ast_mutex_lock(&provlock);
    00287       /* Backup old data */
    00288       memcpy(&tmp, cur, sizeof(tmp));
    00289       /* Restore from src */
    00290       memcpy(cur, src, sizeof(tmp));
    00291       /* Restore important headers */
    00292       memcpy(cur->name, tmp.name, sizeof(cur->name));
    00293       cur->dead = tmp.dead;
    00294       cur->next = tmp.next;
    00295       ast_mutex_unlock(&provlock);
    00296    }
    00297    if (def)
    00298       strncpy(cur->src, def, sizeof(cur->src) - 1);
    00299    else
    00300       cur->src[0] = '\0';
    00301    v = ast_variable_browse(cfg, s);
    00302    while(v) {
    00303       if (!strcasecmp(v->name, "port") || !strcasecmp(v->name, "serverport")) {
    00304          if ((sscanf(v->value, "%5d", &x) == 1) && (x > 0) && (x < 65535)) {
    00305             if (!strcasecmp(v->name, "port")) {
    00306                cur->port = x;
    00307                foundportno = 1;
    00308             } else {
    00309                cur->serverport = x;
    00310                foundserverportno = 1;
    00311             }
    00312          } else
    00313             ast_log(LOG_WARNING, "Ignoring invalid %s '%s' for '%s' at line %d\n", v->name, v->value, s, v->lineno);
    00314       } else if (!strcasecmp(v->name, "server") || !strcasecmp(v->name, "altserver")) {
    00315          hp = ast_gethostbyname(v->value, &h);
    00316          if (hp) {
    00317             memcpy(&ia, hp->h_addr, sizeof(ia));
    00318             if (!strcasecmp(v->name, "server"))
    00319                cur->server = ntohl(ia.s_addr);
    00320             else
    00321                cur->altserver = ntohl(ia.s_addr);
    00322          } else
    00323             ast_log(LOG_WARNING, "Ignoring invalid %s '%s' for '%s' at line %d\n", v->name, v->value, s, v->lineno);
    00324       } else if (!strcasecmp(v->name, "codec")) {
    00325          if ((x = ast_getformatbyname(v->value)) > 0) {
    00326             cur->format = x;
    00327          } else
    00328             ast_log(LOG_WARNING, "Ignoring invalid codec '%s' for '%s' at line %d\n", v->value, s, v->lineno);
    00329       } else if (!strcasecmp(v->name, "tos")) {
    00330          if (sscanf(v->value, "%3d", &x) == 1)
    00331             cur->tos = x & 0xff;
    00332          else if (!strcasecmp(v->value, "lowdelay"))
    00333             cur->tos = IPTOS_LOWDELAY;
    00334          else if (!strcasecmp(v->value, "throughput"))
    00335             cur->tos = IPTOS_THROUGHPUT;
    00336          else if (!strcasecmp(v->value, "reliability"))
    00337             cur->tos = IPTOS_RELIABILITY;
    00338          else if (!strcasecmp(v->value, "mincost"))
    00339             cur->tos = IPTOS_MINCOST;
    00340          else if (!strcasecmp(v->value, "none"))
    00341             cur->tos = 0;
    00342          else
    00343             ast_log(LOG_WARNING, "Invalid tos value at line %d, should be 'lowdelay', 'throughput', 'reliability', 'mincost', or 'none'\n", v->lineno);
    00344       } else if (!strcasecmp(v->name, "user")) {
    00345          strncpy(cur->user, v->value, sizeof(cur->user) - 1);
    00346          if (strcmp(cur->user, v->value))
    00347             ast_log(LOG_WARNING, "Truncating username from '%s' to '%s' for '%s' at line %d\n", v->value, cur->user, s, v->lineno);
    00348       } else if (!strcasecmp(v->name, "pass")) {
    00349          strncpy(cur->pass, v->value, sizeof(cur->pass) - 1);
    00350          if (strcmp(cur->pass, v->value))
    00351             ast_log(LOG_WARNING, "Truncating password from '%s' to '%s' for '%s' at line %d\n", v->value, cur->pass, s, v->lineno);
    00352       } else if (!strcasecmp(v->name, "language")) {
    00353          strncpy(cur->lang, v->value, sizeof(cur->lang) - 1);
    00354          if (strcmp(cur->lang, v->value))
    00355             ast_log(LOG_WARNING, "Truncating language from '%s' to '%s' for '%s' at line %d\n", v->value, cur->lang, s, v->lineno);
    00356       } else if (!strcasecmp(v->name, "flags")) {
    00357          cur->flags = iax_str2flags(v->value);
    00358       } else if (!strncasecmp(v->name, "flags", 5) && strchr(v->name, '+')) {
    00359          cur->flags |= iax_str2flags(v->value);
    00360       } else if (!strncasecmp(v->name, "flags", 5) && strchr(v->name, '-')) {
    00361          cur->flags &= ~iax_str2flags(v->value);
    00362       } else if (strcasecmp(v->name, "template")) {
    00363          ast_log(LOG_WARNING, "Unknown keyword '%s' in definition of '%s' at line %d\n", v->name, s, v->lineno);
    00364       }
    00365       v = v->next;
    00366    }
    00367    if (!foundportno)
    00368       cur->port = IAX_DEFAULT_PORTNO;
    00369    if (!foundserverportno)
    00370       cur->serverport = IAX_DEFAULT_PORTNO;
    00371    return 0;
    00372 }
    00373
    00374 static int iax_process_template(struct ast_config *cfg, char *s, char *def)
    00375 {
    00376    /* Find an already existing one if there */
    00377    struct iax_template *cur;
    00378    int mallocd = 0;
    00379    cur = templates;
    00380    while(cur) {
    00381       if (!strcasecmp(cur->name, s))
    00382          break;
    00383       cur = cur->next;
    00384    }
    00385    if (!cur) {
    00386       mallocd = 1;
    00387       cur = malloc(sizeof(struct iax_template));
    00388       if (!cur) {
    00389          ast_log(LOG_WARNING, "Out of memory!\n");
    00390          return -1;
    00391       }
    00392       /* Initialize entry */
    00393       memset(cur, 0, sizeof(*cur));
    00394       strncpy(cur->name, s, sizeof(cur->name) - 1);
    00395       cur->dead = 1;
    00396    }
    00397    if (!iax_template_parse(cur, cfg, s, def))
    00398       cur->dead = 0;
    00399
    00400    /* Link if we're mallocd */
    00401    if (mallocd) {
    00402       ast_mutex_lock(&provlock);
    00403       cur->next = templates;
    00404       templates = cur;
    00405       ast_mutex_unlock(&provlock);
    00406    }
    00407    return 0;
    00408 }
    00409
    00410 static char show_provisioning_usage[] =
    00411 "Usage: iax show provisioning [template]\n"
    00412 "       Lists all known IAX provisioning templates or a\n"
    00413 "       specific one if specified.\n";
    00414
    00415 static const char *ifthere(const char *s)
    00416 {
    00417    if (strlen(s))
    00418       return s;
    00419    else
    00420       return "<unspecified>";
    00421 }
    00422
    00423 static const char *iax_server(char *a, int alen, unsigned int addr)
    00424 {
    00425    struct in_addr ia;
    00426    if (!addr)
    00427       return "<unspecified>";
    00428    ia.s_addr = htonl(addr);
    00429    return ast_inet_ntoa(a, alen, ia);
    00430 }
    00431
    00432
    00433 static int iax_show_provisioning(int fd, int argc, char *argv[])
    00434 {
    00435    struct iax_template *cur;
    00436    char iabuf[80];   /* Has to be big enough for 'flags' too */
    00437    int found = 0;
    00438    if ((argc != 3) && (argc != 4))
    00439       return RESULT_SHOWUSAGE;
    00440    ast_mutex_lock(&provlock);
    00441    for (cur = templates;cur;cur = cur->next) {
    00442       if ((argc == 3) || (!strcasecmp(argv[3], cur->name)))  {
    00443          if (found) ast_cli(fd, "\n");
    00444          ast_cli(fd, "== %s ==\n", cur->name);
    00445          ast_cli(fd, "Base Templ:   %s\n", strlen(cur->src) ? cur->src : "<none>");
    00446          ast_cli(fd, "Username:     %s\n", ifthere(cur->user));
    00447          ast_cli(fd, "Secret:       %s\n", ifthere(cur->pass));
    00448          ast_cli(fd, "Language:     %s\n", ifthere(cur->lang));
    00449          ast_cli(fd, "Bind Port:    %d\n", cur->port);
    00450          ast_cli(fd, "Server:       %s\n", iax_server(iabuf, sizeof(iabuf), cur->server));
    00451          ast_cli(fd, "Server Port:  %d\n", cur->serverport);
    00452          ast_cli(fd, "Alternate:    %s\n", iax_server(iabuf, sizeof(iabuf), cur->altserver));
    00453          ast_cli(fd, "Flags:        %s\n", iax_provflags2str(iabuf, sizeof(iabuf), cur->flags));
    00454          ast_cli(fd, "Format:       %s\n", ast_getformatname(cur->format));
    00455          ast_cli(fd, "TOS:          %d\n", cur->tos);
    00456          found++;
    00457       }
    00458    }
    00459    ast_mutex_unlock(&provlock);
    00460    if (!found) {
    00461       if (argc == 3)
    00462          ast_cli(fd, "No provisioning templates found\n");
    00463       else
    00464          ast_cli(fd, "No provisioning template matching '%s' found\n", argv[3]);
    00465    }
    00466    return RESULT_SUCCESS;
    00467 }
    00468
    00469 static struct ast_cli_entry  cli_show_provisioning =
    00470    { { "iax2", "show", "provisioning", NULL }, iax_show_provisioning, "Show iax provisioning", show_provisioning_usage, iax_prov_complete_template };
    00471
    00472 static int iax_provision_init(void)
    00473 {
    00474    ast_cli_register(&cli_show_provisioning);
    00475    provinit = 1;
    00476    return 0;
    00477 }
    00478
    00479 int iax_provision_unload(void)
    00480 {
    00481    provinit = 0;
    00482    ast_cli_unregister(&cli_show_provisioning);
    00483    return 0;
    00484 }
    00485
    00486 int iax_provision_reload(void)
    00487 {
    00488    struct ast_config *cfg;
    00489    struct iax_template *cur, *prev, *next;
    00490    char *cat;
    00491    int found = 0;
    00492    if (!provinit)
    00493       iax_provision_init();
    00494    /* Mark all as dead.  No need for locking */
    00495    cur = templates;
    00496    while(cur) {
    00497       cur->dead = 1;
    00498       cur = cur->next;
    00499    }
    00500    cfg = ast_config_load("iaxprov.conf");
    00501    if (cfg) {
    00502       /* Load as appropriate */
    00503       cat = ast_category_browse(cfg, NULL);
    00504       while(cat) {
    00505          if (strcasecmp(cat, "general")) {
    00506             iax_process_template(cfg, cat, found ? "default" : NULL);
    00507             found++;
    00508             if (option_verbose > 2)
    00509                ast_verbose(VERBOSE_PREFIX_3 "Loaded provisioning template '%s'\n", cat);
    00510          }
    00511          cat = ast_category_browse(cfg, cat);
    00512       }
    00513       ast_config_destroy(cfg);
    00514    } else
    00515       ast_log(LOG_NOTICE, "No IAX provisioning configuration found, IAX provisioning disabled.\n");
    00516    ast_mutex_lock(&provlock);
    00517    /* Drop dead entries while locked */
    00518    prev = NULL;
    00519    cur = templates;
    00520    while(cur) {
    00521       next = cur->next;
    00522       if (cur->dead) {
    00523          if (prev)
    00524             prev->next = next;
    00525          else
    00526             templates = next;
    00527          free(cur);
    00528       } else
    00529          prev = cur;
    00530       cur = next;
    00531    }
    00532    ast_mutex_unlock(&provlock);
    00533    /* Purge cached signature DB entries */
    00534    ast_db_deltree("iax/provisioning/cache", NULL);
    00535    return 0;
    00536
    00537 }