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update DNS resolver

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@1555 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Mark Spencer
2003-09-27 00:22:46 +00:00
parent 55512a7328
commit b14e6b526b
3 changed files with 73 additions and 371 deletions
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223
enum.c
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@@ -11,67 +11,27 @@
*
*/
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <regex.h>
#include <unistd.h>
#include <errno.h>
#include <asterisk/logger.h>
#include <asterisk/options.h>
#include <asterisk/enum.h>
#include <asterisk/dns.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;
@@ -81,36 +41,6 @@ static int enumver = 0;
static ast_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;
@@ -171,13 +101,8 @@ static int parse_naptr(unsigned char *dst, int dstsize, char *tech, int techsize
return -1;
}
#if 0
printf("Input: %s\n", naptrinput);
printf("Flags: %s\n", flags);
printf("Services: %s\n", services);
printf("Regexp: %s\n", regexp);
printf("Repl: %s\n", repl);
#endif
ast_log(LOG_DEBUG, "input='%s', flags='%s', services='%s', regexp='%s', repl='%s'\n",
naptrinput, flags, services, regexp, repl);
if (tolower(flags[0]) != 'u') {
ast_log(LOG_WARNING, "Flag must be 'U' or 'u'.\n");
@@ -283,119 +208,56 @@ static int parse_naptr(unsigned char *dst, int dstsize, char *tech, int techsize
return 0;
}
static int parse_answer(unsigned char *dst, int dstlen, unsigned char *tech, int techlen, unsigned char *answer, int len, char *naptrinput)
struct enum_context {
char *dst;
int dstlen;
char *tech;
int techlen;
char *naptrinput;
};
static int enum_callback(void *context, u_char *answer, int len, u_char *fullanswer)
{
/*
* 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;
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), naptrinput))
ast_log(LOG_WARNING, "Failed to parse naptr :(\n");
if (strlen(dst))
return 0;
}
answer += ntohs(ans->size);
}
struct enum_context *c = (struct enum_context *)context;
if (parse_naptr(c->dst, c->dstlen, c->tech, c->techlen, answer, len, c->naptrinput))
ast_log(LOG_WARNING, "Failed to parse naptr :(\n");
if (strlen(c->dst))
return 1;
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];
struct enum_context context;
char tmp[259 + 80];
char naptrinput[80] = "+";
int pos = strlen(number) - 1;
int newpos=0;
int res = -1;
int newpos = 0;
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;
strncat(naptrinput, number, sizeof(naptrinput) - 2);
context.naptrinput = naptrinput;
context.dst = dst;
context.dstlen = dstlen;
context.tech = tech;
context.techlen = techlen;
if (pos > 128)
pos = 128;
while(pos >= 0) {
tmp[newpos++] = number[pos--];
tmp[newpos++] = '.';
}
#if 0
printf("Looking for '%s'\n", tmp);
#endif
if (chan && ast_autoservice_start(chan) < 0)
return -1;
for(;;) {
ast_mutex_lock(&enumlock);
if (version != enumver) {
@@ -411,25 +273,16 @@ int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int ds
ast_mutex_unlock(&enumlock);
if (!s)
break;
res = res_nsearch(&enumstate, tmp, C_IN, T_NAPTR, answer, sizeof(answer));
if (res > 0)
ret = ast_search_dns(&context, tmp, C_IN, T_NAPTR, enum_callback);
if (ret > 0)
break;
}
if (res > 0) {
if ((res = parse_answer(dst, dstlen, tech, techlen, answer, res, naptrinput))) {
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 {
if (ret < 0) {
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;
}