Esempio n. 1
0
static dns_ctx_handle_t *dns_ctx_alloc(const char *ns, int port) {
  void *vh;
  dns_ctx_handle_t *h = NULL;
  pthread_mutex_lock(&dns_ctx_store_lock);
  if(ns == NULL && default_ctx_handle != NULL) {
    /* special case -- default context */
    h = default_ctx_handle;
    noit_atomic_inc32(&h->refcnt);
    goto bail;
  }
  if(ns &&
     noit_hash_retrieve(&dns_ctx_store, ns, strlen(ns), &vh)) {
    h = (dns_ctx_handle_t *)vh;
    noit_atomic_inc32(&h->refcnt);
  }
  else {
    int failed = 0;
    h = calloc(1, sizeof(*h));
    h->ns = ns ? strdup(ns) : NULL;
    h->ctx = dns_new(NULL);
    if(dns_init(h->ctx, 0) != 0) failed++;
    if(ns) {
      if(dns_add_serv(h->ctx, NULL) < 0) failed++;
      if(dns_add_serv(h->ctx, ns) < 0) failed++;
    }
    if(port && port != DNS_PORT) {
      dns_set_opt(h->ctx, DNS_OPT_PORT, port);
    }
    if(dns_open(h->ctx) < 0) failed++;
    if(failed) {
      noitL(nlerr, "dns_open failed\n");
      free(h->ns);
      free(h);
      h = NULL;
      goto bail;
    }
    dns_set_tmcbck(h->ctx, eventer_dns_utm_fn, h);
    h->e = eventer_alloc();
    h->e->mask = EVENTER_READ | EVENTER_EXCEPTION;
    h->e->closure = h;
    h->e->callback = dns_eventer_callback;
    h->e->fd = dns_sock(h->ctx);
    eventer_add(h->e);
    h->refcnt = 1;
    if(!ns)
      default_ctx_handle = h;
    else
      noit_hash_store(&dns_ctx_store, h->ns, strlen(h->ns), h);
  }
 bail:
  pthread_mutex_unlock(&dns_ctx_store_lock);
  return h;
}
Esempio n. 2
0
int
resolv_init(struct ev_loop *loop, char **nameservers, int nameserver_num, int ipv6first)
{
    if (ipv6first)
        resolv_mode = MODE_IPV6_FIRST;
    else
        resolv_mode = MODE_IPV4_FIRST;

    struct dns_ctx *ctx = &dns_defctx;
    if (nameservers == NULL) {
        /* Nameservers not specified, use system resolver config */
        dns_init(ctx, 0);
    } else {
        dns_reset(ctx);

        for (int i = 0; i < nameserver_num; i++) {
            char *server = nameservers[i];
            dns_add_serv(ctx, server);
        }
    }

    int sockfd = dns_open(ctx);
    if (sockfd < 0) {
        FATAL("Failed to open DNS resolver socket");
    }

    if (nameserver_num == 1 && nameservers != NULL) {
        if (strncmp("127.0.0.1", nameservers[0], 9) == 0
            || strncmp("::1", nameservers[0], 3) == 0) {
            if (verbose) {
                LOGI("bind UDP resolver to %s", nameservers[0]);
            }
            if (bind_to_address(sockfd, nameservers[0]) == -1)
                ERROR("bind_to_address");
        }
    }

#ifdef __MINGW32__
    setnonblocking(sockfd);
#else
    int flags = fcntl(sockfd, F_GETFL, 0);
    fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
#endif

    ev_io_init(&resolv_io_watcher, resolv_sock_cb, sockfd, EV_READ);
    resolv_io_watcher.data = ctx;

    ev_io_start(loop, &resolv_io_watcher);

    ev_timer_init(&resolv_timeout_watcher, resolv_timeout_cb, 0.0, 0.0);
    resolv_timeout_watcher.data = ctx;

    dns_set_tmcbck(ctx, dns_timer_setup_cb, loop);

    return sockfd;
}
Esempio n. 3
0
int main(int argc, char **argv) {
  int c;
  struct ipcheck ipc;
  char *nameserver = NULL;
  int zgiven = 0;

  if (!(progname = strrchr(argv[0], '/'))) progname = argv[0];
  else argv[0] = ++progname;

  while((c = getopt(argc, argv, "hqtvms:S:cn:")) != EOF) switch(c) {
  case 's': ++zgiven; addzone(optarg); break;
  case 'S':
    ++zgiven;
    if (addzonefile(optarg)) break;
    fprintf(stderr, "%s: unable to read %s\n", progname, optarg);
    return 1;
  case 'c': ++zgiven; nzones = 0; break;
  case 'q': --verbose; break;
  case 'v': ++verbose; break;
  case 't': do_txt = 1; break;
  case 'n': nameserver = optarg; break;
  case 'm': ++stopfirst; break;
  case 'h':
    printf("%s: %s.\n", progname, version);
    printf("Usage is: %s [options] address..\n", progname);
    printf(
"Where options are:\n"
" -h - print this help and exit\n"
" -s service - add the service (DNSBL zone) to the serice list\n"
" -S service-file - add the DNSBL zone(s) read from the given file\n"
" -c - clear service list\n"
" -v - increase verbosity level (more -vs => more verbose)\n"
" -q - decrease verbosity level (opposite of -v)\n"
" -t - obtain and print TXT records if any\n"
" -m - stop checking after first address match in any list\n"
" -n ipaddr - use the given nameserver instead of the default\n"
"(if no -s or -S option is given, use $RBLCHECK_ZONES, ~/.rblcheckrc\n"
"or /etc/rblcheckrc in that order)\n"
    );
    return 0;
  default:
    fprintf(stderr, "%s: use `%s -h' for help\n", progname, progname);
    return 1;
  }

  if (!zgiven) {
    char *s = getenv("RBLCHECK_ZONES");
    if (s) {
      char *k;
      s = strdup(s);
      k = strtok(s, " \t");
      while(k) {
        addzone(k);
        k = strtok(NULL, " \t");
      }
      free(s);
    }
    else {
      char *path;
      char *home = getenv("HOME");
      if (!home) home = ".";
      path = malloc(strlen(home) + 1 + sizeof(".rblcheckrc"));
      sprintf(path, "%s/.rblcheckrc", home);
      if (!addzonefile(path))
        addzonefile("/etc/rblcheckrc");
      free(path);
    }
  }
  if (!nzones) {
    fprintf(stderr, "%s: no service (zone) list specified (-s or -S option)\n",
            progname);
    return 1;
  }

  argv += optind;
  argc -= optind;

  if (!argc)
    return 0;

  if (dns_init(0) < 0) {
    fprintf(stderr, "%s: unable to initialize DNS library: %s\n",
            progname, strerror(errno));
    return 1;
  }
  if (nameserver) {
    dns_add_serv(NULL, NULL);
    if (dns_add_serv(NULL, nameserver) < 0)
      fprintf(stderr, "%s: unable to use nameserver %s: %s\n",
              progname, nameserver, strerror(errno));
  }
  if (dns_open(NULL) < 0) {
    fprintf(stderr, "%s: unable to initialize DNS library: %s\n",
            progname, strerror(errno));
    return 1;
  }

  for (c = 0; c < argc; ++c) {
    if (c && (verbose > 1 || (verbose == 1 && do_txt))) putchar('\n');
    ipc.name = argv[c];
    submit(&ipc);
    waitdns(&ipc);
    display_result(&ipc);
    if (stopfirst > 1 && listed) break;
  }

  return listed ? 100 : failures ? 2 : 0;
}
Esempio n. 4
0
static void dns_set_serv_internal(struct dns_ctx *ctx, char *serv) {
  dns_add_serv(ctx, NULL);
  for(serv = strtok(serv, space); serv; serv = strtok(NULL, space))
    dns_add_serv(ctx, serv);
}
Esempio n. 5
0
static int dns_init_resolvconf(struct dns_ctx *ctx) {
  char *v;
  char buf[2049];	/* this buffer is used to hold /etc/resolv.conf */
  int has_srch = 0;

  /* read resolv.conf... */
  { int fd = open("/etc/resolv.conf", O_RDONLY);
    if (fd >= 0) {
      int l = read(fd, buf, sizeof(buf) - 1);
      close(fd);
      buf[l < 0 ? 0 : l] = '\0';
    }
    else
      buf[0] = '\0';
  }
  if (buf[0]) {	/* ...and parse it */
    char *line, *nextline;
    line = buf;
    do {
      nextline = strchr(line, '\n');
      if (nextline) *nextline++ = '\0';
      v = line;
      while(*v && !ISSPACE(*v)) ++v;
      if (!*v) continue;
      *v++ = '\0';
      while(ISSPACE(*v)) ++v;
      if (!*v) continue;
      if (strcmp(line, "domain") == 0) {
        dns_set_srch_internal(ctx, strtok(v, space));
	has_srch = 1;
      }
      else if (strcmp(line, "search") == 0) {
        dns_set_srch_internal(ctx, v);
	has_srch = 1;
      }
      else if (strcmp(line, "nameserver") == 0)
        dns_add_serv(ctx, strtok(v, space));
      else if (strcmp(line, "options") == 0)
        dns_set_opts(ctx, v);
    } while((line = nextline) != NULL);
  }

  buf[sizeof(buf)-1] = '\0';

  /* get list of nameservers from env. vars. */
  if ((v = getenv("NSCACHEIP")) != NULL ||
      (v = getenv("NAMESERVERS")) != NULL) {
    strncpy(buf, v, sizeof(buf) - 1);
    dns_set_serv_internal(ctx, buf);
  }
  /* if $LOCALDOMAIN is set, use it for search list */
  if ((v = getenv("LOCALDOMAIN")) != NULL) {
    strncpy(buf, v, sizeof(buf) - 1);
    dns_set_srch_internal(ctx, buf);
    has_srch = 1;
  }
  if ((v = getenv("RES_OPTIONS")) != NULL)
    dns_set_opts(ctx, v);

  /* if still no search list, use local domain name */
  if (has_srch &&
      gethostname(buf, sizeof(buf) - 1) == 0 &&
      (v = strchr(buf, '.')) != NULL &&
      *++v != '\0')
    dns_add_srch(ctx, v);

  return 0;
}
Esempio n. 6
0
static int dns_init_resolvconf(struct dns_ctx *ctx) {
  char *v;
  char buf[4097];	/* this buffer is used to hold /etc/resolv.conf */
  int has_srch = 0;

  /* read resolv.conf... */
  { int fd = open("/etc/resolv.conf", O_RDONLY);
    if (fd >= 0) {
      int l = read(fd, buf, sizeof(buf) - 1);
      close(fd);
      buf[l < 0 ? 0 : l] = '\0';
    }
    else
      buf[0] = '\0';
  }
  if (buf[0]) {	/* ...and parse it */
    char *line, *nextline;
    line = buf;
    do {
      nextline = strchr(line, '\n');
      if (nextline) *nextline++ = '\0';
      v = line;
      while(*v && !ISSPACE(*v)) ++v;
      if (!*v) continue;
      *v++ = '\0';
      while(ISSPACE(*v)) ++v;
      if (!*v) continue;
      if (strcmp(line, "domain") == 0) {
        dns_set_srch_internal(ctx, strtok(v, space));
	has_srch = 1;
      }
      else if (strcmp(line, "search") == 0) {
        dns_set_srch_internal(ctx, v);
	has_srch = 1;
      }
      else if (strcmp(line, "nameserver") == 0)
        dns_add_serv(ctx, strtok(v, space));
      else if (strcmp(line, "options") == 0)
        dns_set_opts(ctx, v);
    } while((line = nextline) != NULL);
  }

  buf[sizeof(buf)-1] = '\0';

#if TARGET_OS_IPHONE
  // SOLUTION FOUND:
  // http://iphone.galloway.me.uk/2009/11/iphone-dns-servers/
  
  // ORIGINAL CODE EXAMPLE:
  //
  //      #if TARGET_OS_IPHONE
  //      #include <resolv.h>
  //      #endif
  // 
  //      ...
  // 
  //      #if TARGET_OS_IPHONE
  //      // XXX: On the iPhone we need to get the DNS servers using resolv.h magic
  //      if ((_res.options & RES_INIT) == 0) res_init();
  //      channel->nservers = _res.nscount;
  //      channel->servers = malloc(channel->nservers * sizeof(struct server_state));
  //      memset(channel->servers, '\0', channel->nservers * sizeof(struct server_state));
  // 
  //      int i;
  //      for (i = 0; i < channel->nservers; i++)
  //      {
  //          memcpy(&channel->servers[i].addr, &_res.nsaddr_list[i].sin_addr, sizeof(struct in_addr));
  //      }
  //      #endif

  if ((_res.options & RES_INIT) == 0) res_init();
  
  int i;
  for (i = 0; i < _res.nscount; i++)
  {
    struct sockaddr_in address;
    memset(&address, 0, sizeof(address));
    address.sin_family = AF_INET;
    address.sin_addr = _res.nsaddr_list[i].sin_addr;              // loopback is a special case since it could be stored as ::1 in IPv6

    dns_add_serv_s(ctx, (struct sockaddr *)&address);
  }
#endif //TARGET_OS_IPHONE

  /* get list of nameservers from env. vars. */
  if ((v = getenv("NSCACHEIP")) != NULL ||
      (v = getenv("NAMESERVERS")) != NULL) {
    strncpy(buf, v, sizeof(buf) - 1);
    dns_set_serv_internal(ctx, buf);
  }
  /* if $LOCALDOMAIN is set, use it for search list */
  if ((v = getenv("LOCALDOMAIN")) != NULL) {
    strncpy(buf, v, sizeof(buf) - 1);
    dns_set_srch_internal(ctx, buf);
    has_srch = 1;
  }
  if ((v = getenv("RES_OPTIONS")) != NULL)
    dns_set_opts(ctx, v);

  /* if still no search list, use local domain name */
  if (has_srch &&
      gethostname(buf, sizeof(buf) - 1) == 0 &&
      (v = strchr(buf, '.')) != NULL &&
      *++v != '\0')
    dns_add_srch(ctx, v);

  return 0;
}
Esempio n. 7
0
void noit_check_resolver_init() {
  int cnt;
  mtev_conf_section_t *servers, *searchdomains;
  eventer_t e;
  if(dns_init(NULL, 0) < 0)
    mtevL(noit_error, "dns initialization failed.\n");
  dns_ctx = dns_new(NULL);
  if(dns_init(dns_ctx, 0) != 0) {
    mtevL(noit_error, "dns initialization failed.\n");
    exit(-1);
  }

  /* Optional servers */
  servers = mtev_conf_get_sections(NULL, "//resolver//server", &cnt);
  if(cnt) {
    int i;
    char server[128];
    dns_add_serv(dns_ctx, NULL); /* reset */
    for(i=0;i<cnt;i++) {
      if(mtev_conf_get_stringbuf(servers[i], "self::node()",
                                 server, sizeof(server))) {
        if(dns_add_serv(dns_ctx, server) < 0) {
          mtevL(noit_error, "Failed adding DNS server: %s\n", server);
        }
      }
    }
    free(servers);
  }
  searchdomains = mtev_conf_get_sections(NULL, "//resolver//search", &cnt);
  if(cnt) {
    int i;
    char search[128];
    dns_add_srch(dns_ctx, NULL); /* reset */
    for(i=0;i<cnt;i++) {
      if(mtev_conf_get_stringbuf(searchdomains[i], "self::node()",
                                 search, sizeof(search))) {
        if(dns_add_srch(dns_ctx, search) < 0) {
          mtevL(noit_error, "Failed adding DNS search path: %s\n", search);
        }
        else if(dns_search_flag) dns_search_flag = 0; /* enable search */
      }
    }
    free(searchdomains);
  }

  if(mtev_conf_get_int(NULL, "//resolver/@ndots", &cnt))
    dns_set_opt(dns_ctx, DNS_OPT_NDOTS, cnt);

  if(mtev_conf_get_int(NULL, "//resolver/@ntries", &cnt))
    dns_set_opt(dns_ctx, DNS_OPT_NTRIES, cnt);

  if(mtev_conf_get_int(NULL, "//resolver/@timeout", &cnt))
    dns_set_opt(dns_ctx, DNS_OPT_TIMEOUT, cnt);

  if(dns_open(dns_ctx) < 0) {
    mtevL(noit_error, "dns open failed.\n");
    exit(-1);
  }
  eventer_name_callback("dns_cache_callback", dns_cache_callback);
  dns_set_tmcbck(dns_ctx, dns_cache_utm_fn, dns_ctx);
  e = eventer_alloc();
  e->mask = EVENTER_READ | EVENTER_EXCEPTION;
  e->closure = dns_ctx;
  e->callback = dns_cache_callback;
  e->fd = dns_sock(dns_ctx);
  eventer_add(e);

  mtev_skiplist_init(&nc_dns_cache);
  mtev_skiplist_set_compare(&nc_dns_cache, name_lookup, name_lookup_k);
  mtev_skiplist_add_index(&nc_dns_cache, refresh_idx, refresh_idx_k);

  /* maybe load it from cache */
  if(noit_resolver_cache_load_hook_exists()) {
    struct timeval now;
    char *key;
    void *data;
    int len;
    gettimeofday(&now, NULL);
    while(noit_resolver_cache_load_hook_invoke(&key, &data, &len) == MTEV_HOOK_CONTINUE) {
      dns_cache_node *n;
      n = calloc(1, sizeof(*n));
      if(dns_cache_node_deserialize(n, data, len) >= 0) {
        n->target = strdup(key);
        /* if the TTL indicates that it will expire in less than 60 seconds
         * (including stuff that should have already expired), then fudge
         * the last_updated time to make it expire some random time within
         * the next 60 seconds.
         */
        if(n->last_needed > now.tv_sec || n->last_updated > now.tv_sec)
          break; /* impossible */

        n->last_needed = now.tv_sec;
        if(n->last_updated + n->ttl < now.tv_sec + 60) {
          int fudge = MIN(60, n->ttl) + 1;
          n->last_updated = now.tv_sec - n->ttl + (lrand48() % fudge);
        }
        DCLOCK();
        mtev_skiplist_insert(&nc_dns_cache, n);
        DCUNLOCK();
        n = NULL;
      }
      else {
        mtevL(noit_error, "Failed to deserialize resolver cache record.\n");
      }
      if(n) dns_cache_node_free(n);
      if(key) free(key);
      if(data) free(data);
    }
  }

  noit_check_resolver_loop(NULL, 0, NULL, NULL);
  register_console_dns_cache_commands();

  mtev_hash_init(&etc_hosts_cache);
  noit_check_etc_hosts_cache_refresh(NULL, 0, NULL, NULL);
}
Esempio n. 8
0
static dns_ctx_handle_t *dns_module_dns_ctx_alloc(noit_module_t *self, const char *ns, int port) {
  void *vh;
  char *hk = NULL;
  dns_mod_config_t *conf = noit_module_get_userdata(self);
  int randkey = random() % conf->contexts;
  dns_ctx_handle_t *h = NULL;
  if(ns && *ns == '\0') ns = NULL;
  pthread_mutex_lock(&dns_ctx_store_lock);
  if(ns == NULL && default_ctx_handle != NULL) {
    /* special case -- default context */
    h = default_ctx_handle;
    dns_module_dns_ctx_acquire(h);
    goto bail;
  }

  if (ns != NULL) {
    int len = snprintf(NULL, 0, "%s:%d:%d", ns, port, randkey); 
    hk = (char *)malloc(len+1);
    snprintf(hk, len+1, "%s:%d:%d", ns, port, randkey);
  }

  if(ns &&
     noit_hash_retrieve(&dns_ctx_store, hk, strlen(hk), &vh)) {
    h = (dns_ctx_handle_t *)vh;
    dns_module_dns_ctx_acquire(h);
    free(hk);
  }
  else {
    int failed = 0;
    h = calloc(1, sizeof(*h));
    h->ns = ns ? strdup(ns) : NULL;
    h->ctx = dns_new(NULL);
    if(dns_init(h->ctx, 0) != 0) {
      noitL(nlerr, "dns_init failed\n");
      failed++;
    }
    dns_set_dbgfn(h->ctx, dns_debug_wrap);
    if(ns) {
      if(dns_add_serv(h->ctx, NULL) < 0) {
        noitL(nlerr, "dns_add_serv(NULL) failed\n");
        failed++;
      }
      if(dns_add_serv(h->ctx, ns) < 0) {
        noitL(nlerr, "dns_add_serv(%s) failed\n", ns);
        failed++;
      }
    }
    if(port && port != DNS_PORT) {
      dns_set_opt(h->ctx, DNS_OPT_PORT, port);
    }
    if(dns_open(h->ctx) < 0) {
      noitL(nlerr, "dns_open failed\n");
      failed++;
    }
    if(failed) {
      free(h->ns);
      dns_free(h->ctx);
      free(h);
      free(hk);
      h = NULL;
      goto bail;
    }
    h->hkey = hk;
    dns_set_tmcbck(h->ctx, dns_module_eventer_dns_utm_fn, h);
    h->e = eventer_alloc();
    h->e->mask = EVENTER_READ | EVENTER_EXCEPTION;
    h->e->closure = h;
    h->e->callback = dns_module_eventer_callback;
    h->e->fd = dns_sock(h->ctx);
    eventer_add(h->e);
    h->refcnt = 1;
    if(!ns)
      default_ctx_handle = h;
    else
      noit_hash_store(&dns_ctx_store, h->hkey, strlen(h->hkey), h);
  }
 bail:
  pthread_mutex_unlock(&dns_ctx_store_lock);
  return h;
}