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"
 
#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 "asterisk/format_cache.h"
#include "asterisk/format_compatibility.h"
 
#include "include/iax2.h"
#include "include/provision.h"
#include "include/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 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")) {
            struct ast_sockaddr addr = { {0,} };
            if (ast_sockaddr_resolve_first_af(&addr, v->value, PARSE_PORT_FORBID, AF_INET)) {
                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"))
                    cur->server = ast_sockaddr_ipv4(&addr);
                else
                    cur->altserver = ast_sockaddr_ipv4(&addr);
            }
        } else if (!strcasecmp(v->name, "codec")) {
            struct ast_format *tmpfmt;
            if ((tmpfmt = ast_format_cache_get(v->value))) {
                cur->format = ast_format_compatibility_format2bitfield(tmpfmt);
                ao2_ref(tmpfmt, -1);
            } 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;
}