mirror of https://github.com/asterisk/asterisk
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
384 lines
9.0 KiB
384 lines
9.0 KiB
/*
|
|
* ENUM Support for Asterisk
|
|
*
|
|
* Copyright (C) 2003 Digium
|
|
*
|
|
* Written by Mark Spencer <markster@digium.com>
|
|
*
|
|
* Funding provided by nic.at
|
|
*
|
|
* Distributed under the terms of the GNU GPL
|
|
*
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <resolv.h>
|
|
#include <errno.h>
|
|
|
|
#include <asterisk/logger.h>
|
|
#include <asterisk/options.h>
|
|
#include <asterisk/enum.h>
|
|
#include <asterisk/channel.h>
|
|
#include <asterisk/config.h>
|
|
|
|
#define MAX_SIZE 4096
|
|
|
|
#define TOPLEV "e164.arpa."
|
|
|
|
typedef struct {
|
|
unsigned id :16; /* query identification number */
|
|
#if BYTE_ORDER == BIG_ENDIAN
|
|
/* fields in third byte */
|
|
unsigned qr: 1; /* response flag */
|
|
unsigned opcode: 4; /* purpose of message */
|
|
unsigned aa: 1; /* authoritive answer */
|
|
unsigned tc: 1; /* truncated message */
|
|
unsigned rd: 1; /* recursion desired */
|
|
/* fields in fourth byte */
|
|
unsigned ra: 1; /* recursion available */
|
|
unsigned unused :1; /* unused bits (MBZ as of 4.9.3a3) */
|
|
unsigned ad: 1; /* authentic data from named */
|
|
unsigned cd: 1; /* checking disabled by resolver */
|
|
unsigned rcode :4; /* response code */
|
|
#endif
|
|
#if BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
|
|
/* fields in third byte */
|
|
unsigned rd :1; /* recursion desired */
|
|
unsigned tc :1; /* truncated message */
|
|
unsigned aa :1; /* authoritive answer */
|
|
unsigned opcode :4; /* purpose of message */
|
|
unsigned qr :1; /* response flag */
|
|
/* fields in fourth byte */
|
|
unsigned rcode :4; /* response code */
|
|
unsigned cd: 1; /* checking disabled by resolver */
|
|
unsigned ad: 1; /* authentic data from named */
|
|
unsigned unused :1; /* unused bits (MBZ as of 4.9.3a3) */
|
|
unsigned ra :1; /* recursion available */
|
|
#endif
|
|
/* remaining bytes */
|
|
unsigned qdcount :16; /* number of question entries */
|
|
unsigned ancount :16; /* number of answer entries */
|
|
unsigned nscount :16; /* number of authority entries */
|
|
unsigned arcount :16; /* number of resource entries */
|
|
} dns_HEADER;
|
|
|
|
static struct enum_search {
|
|
char toplev[80];
|
|
struct enum_search *next;
|
|
} *toplevs;
|
|
|
|
static int enumver = 0;
|
|
|
|
static pthread_mutex_t enumlock = AST_MUTEX_INITIALIZER;
|
|
|
|
static int skip_name(unsigned char *s, int len)
|
|
{
|
|
/* Shamelessly take from SER */
|
|
int x = 0;
|
|
while(x < len) {
|
|
if (!*s) {
|
|
s++;
|
|
x++;
|
|
break;
|
|
}
|
|
if (((*s) & 0xc0) == 0xc0) {
|
|
s += 2;
|
|
x += 2;
|
|
break;
|
|
}
|
|
x += *s + 1;
|
|
s += *s + 1;
|
|
}
|
|
if (x >= len)
|
|
return -1;
|
|
return x;
|
|
}
|
|
|
|
struct dn_answer {
|
|
unsigned short rtype;
|
|
unsigned short class;
|
|
unsigned int ttl;
|
|
unsigned short size;
|
|
} __attribute__ ((__packed__));
|
|
|
|
struct naptr {
|
|
unsigned short order;
|
|
unsigned short pref;
|
|
} __attribute__ ((__packed__));
|
|
|
|
static int parse_ie(unsigned char *data, int maxdatalen, unsigned char *src, int srclen)
|
|
{
|
|
int len, olen;
|
|
len = olen = (int)src[0];
|
|
src++;
|
|
srclen--;
|
|
if (len > srclen) {
|
|
ast_log(LOG_WARNING, "Want %d, got %d\n", len, srclen);
|
|
return -1;
|
|
}
|
|
if (len > maxdatalen)
|
|
len = maxdatalen;
|
|
memcpy(data, src, len);
|
|
return olen + 1;
|
|
}
|
|
|
|
static int parse_naptr(unsigned char *dst, int dstsize, char *tech, int techsize, unsigned char *answer, int len)
|
|
{
|
|
unsigned char *oanswer = answer;
|
|
unsigned char flags[80] = "";
|
|
unsigned char services[80] = "";
|
|
unsigned char regexp[80] = "";
|
|
unsigned char repl[80] = "";
|
|
int res;
|
|
|
|
if (len < sizeof(struct naptr)) {
|
|
printf("Length too short\n");
|
|
return -1;
|
|
}
|
|
answer += sizeof(struct naptr);
|
|
len -= sizeof(struct naptr);
|
|
if ((res = parse_ie(flags, sizeof(flags) - 1, answer, len)) < 0) {
|
|
ast_log(LOG_WARNING, "Failed to get flags\n");
|
|
return -1;
|
|
} else { answer += res; len -= res; }
|
|
if ((res = parse_ie(services, sizeof(services) - 1, answer, len)) < 0) {
|
|
ast_log(LOG_WARNING, "Failed to get services\n");
|
|
return -1;
|
|
} else { answer += res; len -= res; }
|
|
if ((res = parse_ie(regexp, sizeof(regexp) - 1, answer, len)) < 0)
|
|
return -1; else { answer += res; len -= res; }
|
|
if ((res = dn_expand(oanswer,answer + len,answer, repl, sizeof(repl) - 1)) < 0) {
|
|
ast_log(LOG_WARNING, "Failed to expand hostname\n");
|
|
return -1;
|
|
}
|
|
#if 0
|
|
printf("Flags: %s\n", flags);
|
|
printf("Services: %s\n", services);
|
|
printf("Regexp: %s\n", regexp);
|
|
printf("Repl: %s\n", repl);
|
|
#endif
|
|
if (!strncmp(regexp, "!^.*$!", 6)) {
|
|
if (!strncmp(services, "E2U+voice:", 10)) {
|
|
if (regexp[strlen(regexp) - 1] == '!')
|
|
regexp[strlen(regexp) - 1] = '\0';
|
|
#if 0
|
|
printf("Technology: %s\n", services + 10);
|
|
printf("Destination: %s\n", regexp + 6);
|
|
#endif
|
|
strncpy(dst, regexp + 6, dstsize);
|
|
strncpy(tech, services + 10, techsize);
|
|
}
|
|
} else
|
|
ast_log(LOG_WARNING, "Non-total substitution not yet supported\n");
|
|
return 0;
|
|
}
|
|
|
|
static int parse_answer(unsigned char *dst, int dstlen, unsigned char *tech, int techlen, unsigned char *answer, int len)
|
|
{
|
|
/*
|
|
* This function is influenced by "ser" the SIP router.
|
|
*/
|
|
int x;
|
|
int res;
|
|
dns_HEADER *h;
|
|
struct dn_answer *ans;
|
|
dst[0] = '\0';
|
|
tech[0] = '\0';
|
|
#if 0
|
|
for (x=0;x<len;x++) {
|
|
if ((answer[x] < 32) || (answer[x] > 127)) {
|
|
if (lastlit)
|
|
printf("\"");
|
|
printf(" 0x%02x", answer[x]);
|
|
lastlit = 0;
|
|
} else {
|
|
if (!lastlit)
|
|
printf(" \"");
|
|
printf("%c", answer[x]);
|
|
lastlit = 1;
|
|
}
|
|
}
|
|
printf("\n");
|
|
#endif
|
|
h = (dns_HEADER *)answer;
|
|
/* Skip over DNS header */
|
|
answer += sizeof(dns_HEADER);
|
|
len -= sizeof(dns_HEADER);
|
|
#if 0
|
|
printf("Query count: %d\n", ntohs(h->qdcount));
|
|
#endif
|
|
for (x=0;x<ntohs(h->qdcount);x++) {
|
|
if ((res = skip_name(answer, len)) < 0) {
|
|
ast_log(LOG_WARNING, "Couldn't skip over name\n");
|
|
return -1;
|
|
}
|
|
answer += res;
|
|
len -= res;
|
|
answer += 4; /* Skip QCODE / QCLASS */
|
|
len -= 4;
|
|
if (len < 0) {
|
|
ast_log(LOG_WARNING, "Strange query size\n");
|
|
return -1;
|
|
}
|
|
}
|
|
#if 0
|
|
printf("Length remaining: %d\n", len);
|
|
printf("Answer count: %d\n", ntohs(h->ancount));
|
|
printf("Looking for %d/%d\n", C_IN, T_NAPTR);
|
|
#endif
|
|
for (x=0;x<ntohs(h->ancount);x++) {
|
|
if ((res = skip_name(answer, len) < 0)) {
|
|
ast_log(LOG_WARNING, "Failed to skip name :(\n");
|
|
return -1;
|
|
}
|
|
answer += res;
|
|
len -= res;
|
|
/* XXX Why am I adding 2 here? XXX */
|
|
answer += 2;
|
|
len -= 2;
|
|
ans = (struct dn_answer *)answer;
|
|
answer += sizeof(struct dn_answer);
|
|
len -= sizeof(struct dn_answer);
|
|
if (len < 0)
|
|
return -1;
|
|
#if 0
|
|
printf("Type: %d, class: %d, ttl: %d, length: %d\n", ntohs(ans->rtype), ntohs(ans->class),
|
|
ntohl(ans->ttl), ntohs(ans->size));
|
|
#endif
|
|
len -= ntohs(ans->size);
|
|
if (len < 0) {
|
|
ast_log(LOG_WARNING, "Length exceeds frame\n");
|
|
return -1;
|
|
}
|
|
if ((ntohs(ans->class) == C_IN) && (ntohs(ans->rtype) == T_NAPTR)) {
|
|
if (parse_naptr(dst, dstlen, tech, techlen, answer, ntohs(ans->size)))
|
|
ast_log(LOG_WARNING, "Failed to parse naptr :(\n");
|
|
if (strlen(dst))
|
|
return 0;
|
|
}
|
|
answer += ntohs(ans->size);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int dstlen, char *tech, int techlen)
|
|
{
|
|
unsigned char answer[MAX_SIZE];
|
|
char tmp[259 + 80];
|
|
int pos = strlen(number) - 1;
|
|
int newpos=0;
|
|
int res = -1;
|
|
int ret = -1;
|
|
struct enum_search *s = NULL;
|
|
int version = -1;
|
|
struct __res_state enumstate;
|
|
res_ninit(&enumstate);
|
|
if (chan && ast_autoservice_start(chan) < 0)
|
|
return -1;
|
|
|
|
if (pos > 128)
|
|
pos = 128;
|
|
while(pos >= 0) {
|
|
tmp[newpos++] = number[pos--];
|
|
tmp[newpos++] = '.';
|
|
}
|
|
#if 0
|
|
printf("Looking for '%s'\n", tmp);
|
|
#endif
|
|
|
|
for(;;) {
|
|
ast_pthread_mutex_lock(&enumlock);
|
|
if (version != enumver) {
|
|
/* Ooh, a reload... */
|
|
s = toplevs;
|
|
} else {
|
|
s = s->next;
|
|
}
|
|
if (s) {
|
|
strcpy(tmp + newpos, s->toplev);
|
|
}
|
|
ast_pthread_mutex_unlock(&enumlock);
|
|
if (!s)
|
|
break;
|
|
res = res_nsearch(&enumstate, tmp, C_IN, T_NAPTR, answer, sizeof(answer));
|
|
if (res > 0)
|
|
break;
|
|
}
|
|
if (res > 0) {
|
|
if ((res = parse_answer(dst, dstlen, tech, techlen, answer, res))) {
|
|
ast_log(LOG_WARNING, "Parse error returned %d\n", res);
|
|
ret = 0;
|
|
} else {
|
|
ast_log(LOG_DEBUG, "Found technology '%s', destination '%s'\n", tech, dst);
|
|
ret = 1;
|
|
}
|
|
} else {
|
|
ast_log(LOG_DEBUG, "No such number found: %s (%s)\n", tmp, strerror(errno));
|
|
ret = 0;
|
|
}
|
|
if (chan)
|
|
ret |= ast_autoservice_stop(chan);
|
|
res_nclose(&enumstate);
|
|
return ret;
|
|
}
|
|
|
|
static struct enum_search *enum_newtoplev(char *s)
|
|
{
|
|
struct enum_search *tmp;
|
|
tmp = malloc(sizeof(struct enum_search));
|
|
if (tmp) {
|
|
memset(tmp, 0, sizeof(struct enum_search));
|
|
strncpy(tmp->toplev, s, sizeof(tmp->toplev) - 1);
|
|
}
|
|
return tmp;
|
|
}
|
|
|
|
int ast_enum_init(void)
|
|
{
|
|
struct ast_config *cfg;
|
|
struct enum_search *s, *sl;
|
|
struct ast_variable *v;
|
|
|
|
/* Destroy existing list */
|
|
ast_pthread_mutex_lock(&enumlock);
|
|
s = toplevs;
|
|
while(s) {
|
|
sl = s;
|
|
s = s->next;
|
|
free(sl);
|
|
}
|
|
toplevs = NULL;
|
|
cfg = ast_load("enum.conf");
|
|
if (cfg) {
|
|
sl = NULL;
|
|
v = ast_variable_browse(cfg, "general");
|
|
while(v) {
|
|
if (!strcasecmp(v->name, "search")) {
|
|
s = enum_newtoplev(v->value);
|
|
if (s) {
|
|
if (sl)
|
|
sl->next = s;
|
|
else
|
|
toplevs = s;
|
|
sl = s;
|
|
}
|
|
}
|
|
v = v->next;
|
|
}
|
|
ast_destroy(cfg);
|
|
} else {
|
|
toplevs = enum_newtoplev(TOPLEV);
|
|
}
|
|
enumver++;
|
|
ast_pthread_mutex_unlock(&enumlock);
|
|
return 0;
|
|
}
|
|
|
|
int ast_enum_reload(void)
|
|
{
|
|
return ast_enum_init();
|
|
}
|