diff options
author | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 2003-06-12 22:14:03 +0000 |
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committer | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 2003-06-12 22:14:03 +0000 |
commit | 4e2c1d74ecc1852eeb081095bb875fd20ac7b161 (patch) | |
tree | 89ffdc901f8078451e4078c82195d1b44d623cef /srv.c | |
parent | d73374e107de6c78db4b2b9bdbbad3ed6d2fd484 (diff) |
Add missing srv.c and srv.h files
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@1086 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'srv.c')
-rwxr-xr-x | srv.c | 299 |
1 files changed, 299 insertions, 0 deletions
@@ -0,0 +1,299 @@ +/* + * 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 <sys/types.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/nameser.h> +#include <resolv.h> +#include <errno.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__)); + +struct srv { + unsigned short priority; + unsigned short weight; + 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; + 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_srv(unsigned char *host, int hostlen, int *portno, unsigned char *answer, int len) +{ + int res = 0; + struct srv *srv = (struct srv *)answer; + char repl[256] = ""; + char *oanswer = answer; + + if (len < sizeof(struct srv)) { + printf("Length too short\n"); + return -1; + } + answer += sizeof(struct srv); + len -= sizeof(struct srv); + + 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 (res && strcmp(repl, ".")) { + if (host) { + strncpy(host, repl, hostlen - 1); + host[hostlen] = '\0'; + } + if (portno) + *portno = ntohs(srv->portnum); + res = 1; + } + +#if 0 + 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 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"); +#endif + return 0; +} + +static int parse_answer(unsigned char *host, int hostlen, int *port, char *answer, int len) +{ + /* + * This function is influenced by "ser" the SIP router. + */ + int x; + int res; + dns_HEADER *h; + struct dn_answer *ans; + host[0] = '\0'; + *port = 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, 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(host, hostlen, port, answer, ntohs(ans->size))) + ast_log(LOG_WARNING, "Failed to parse srv :(\n"); + if (strlen(host)) + return 0; + } + answer += ntohs(ans->size); + } + 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]; + + 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; + } + if (chan) + ret |= ast_autoservice_stop(chan); + res_nclose(&srvstate); + return ret; +} |