diff options
Diffstat (limited to 'srv.c')
| -rwxr-xr-x | srv.c | 217 |
1 files changed, 33 insertions, 184 deletions
@@ -11,68 +11,19 @@ * */ -#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 <stdio.h> +#include <string.h> +#include <unistd.h> +#include <asterisk/channel.h> #include <asterisk/logger.h> -#include <asterisk/options.h> #include <asterisk/srv.h> -#include <asterisk/channel.h> -#include <asterisk/config.h> - -#define MAX_SIZE 4096 - -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; - -struct dn_answer { - unsigned short rtype; - unsigned short class; - unsigned int ttl; - unsigned short size; -} __attribute__ ((__packed__)); +#include <asterisk/dns.h> +#include <asterisk/options.h> struct srv { unsigned short priority; @@ -80,29 +31,6 @@ struct srv { unsigned short portnum; } __attribute__ ((__packed__)); -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; -} - static int parse_ie(unsigned char *data, int maxdatalen, unsigned char *src, int srclen) { int len, olen; @@ -149,124 +77,45 @@ static int parse_srv(unsigned char *host, int hostlen, int *portno, unsigned cha return(-1); } -static int parse_answer(unsigned char *host, int hostlen, int *port, char *answer, int len) +struct srv_context { + char *host; + int hostlen; + int *port; +}; + +static int srv_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; -/* int lastlit = 1; */ - char *oanswer = answer; - host[0] = '\0'; - *port = 0; + struct srv_context *c = (struct srv_context *)context; -#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, already at %04x\n", len, 0x2a + (answer - oanswer)); - printf("Answer count: %d\n", ntohs(h->ancount)); - printf("Looking for %d/%d\n", C_IN, T_SRV); - printf("Answer so far: %02x %02x %02x %02x %02x %02x\n", answer[0], answer[1], answer[2], answer[3], answer[4], answer[5]); -#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 (%04x), class: %d (%04x), ttl: %d (%08x), length: %d (%04x)\n", ntohs(ans->rtype), ntohs(ans->rtype), ntohs(ans->class), ntohs(ans->class), - ntohl(ans->ttl), ntohl(ans->ttl), ntohs(ans->size), ntohs(ans->size)); -#endif - len -= ntohs(ans->size); - if (len < 0) { - ast_log(LOG_WARNING, "Length exceeds frame by %d\n", -len); - return -1; - } - if ((ntohs(ans->class) == C_IN) && (ntohs(ans->rtype) == T_SRV)) { + if (parse_srv(c->host, c->hostlen, c->port, answer, len, fullanswer)) + ast_log(LOG_WARNING, "Failed to parse srv\n"); - if (parse_srv(host, hostlen, port, answer, ntohs(ans->size),oanswer)) - ast_log(LOG_WARNING, "Failed to parse srv :(\n"); + if (strlen(c->host)) + return 1; - if (strlen(host)) - return 0; - } - answer += ntohs(ans->size); - } - return 0; + return 0; } int ast_get_srv(struct ast_channel *chan, char *host, int hostlen, int *port, const char *service) { - int res; - int ret = -1; - struct __res_state srvstate; - char answer[MAX_SIZE]; + struct srv_context context; + int ret; + + context.host = host; + context.hostlen = hostlen; + context.port = port; - if (*port) - *port = 0; - res_ninit(&srvstate); if (chan && ast_autoservice_start(chan) < 0) return -1; - res = res_nsearch(&srvstate, service, C_IN, T_SRV, answer, sizeof(answer)); - if (res > 0) { - if ((res = parse_answer(host, hostlen, port, answer, res))) { - ast_log(LOG_WARNING, "Parse error returned %d\n", res); - ret = 0; - } else { - ast_log(LOG_DEBUG, "Found host '%s', port '%d'\n", host, *port); - ret = 1; - } - } else { - ast_log(LOG_DEBUG, "No such service found: %s (%s)\n", service, strerror(errno)); - ret = 0; - } + + ret = ast_search_dns(&context, service, C_IN, T_SRV, srv_callback); + if (chan) ret |= ast_autoservice_stop(chan); - res_nclose(&srvstate); + + if (ret <= 0) + return ret; + strcpy(host, ""); + *port = -1; return ret; } |