/** * Try with next host in the (already shuffled) list. */ static void uhc_try_next(void) { host_addr_t addr; g_assert(uhc_connecting); g_assert(uhc_ctx.timeout_ev == NULL); if (!uhc_pick()) { uhc_connecting = FALSE; return; } /* * The following may recurse if resolution is synchronous, but * we're protected by the `attempts' counter. */ if (string_to_host_addr(uhc_ctx.host, NULL, &addr)) { uhc_ctx.addr = addr; if (GNET_PROPERTY(bootstrap_debug)) g_debug("BOOT UDP host cache \"%s\"", uhc_ctx.host); uhc_send_ping(); } else { (void) adns_resolve(uhc_ctx.host, settings_dns_net(), uhc_host_resolved, NULL); } }
/** * Request asynchronous DNS resolution for item, prior to inserting to * the whitelist or updating the existing host address (when revalidating). */ static void whitelist_dns_resolve(struct whitelist *item, bool revalidate) { struct whitelist_dns *ctx; char *host; g_assert(item != NULL); g_assert(revalidate || !is_host_addr(item->addr)); g_assert(item->host != NULL); /* * Since resolution is normally going to happen asynchronously, we must * keep track of the generation at which the resolution was requested. */ WALLOC(ctx); ctx->item = item; ctx->generation = whitelist_generation; ctx->revalidate = revalidate; host = item->host->name; if (adns_resolve(host, settings_dns_net(), whitelist_dns_cb, ctx)) { /* Asynchronous resolution */ if (GNET_PROPERTY(whitelist_debug) > 1) log_whitelist_item(item, "asynchronously resolving"); } else { /* Synchronous resolution, whitelist_dns_cb() already called */ } }
/** * Loads the whitelist into memory. */ static void G_COLD whitelist_retrieve(void) { char line[1024]; FILE *f; filestat_t st; unsigned linenum = 0; file_path_t fp[1]; whitelist_generation++; file_path_set(fp, settings_config_dir(), whitelist_file); f = file_config_open_read_norename("Host Whitelist", fp, N_ITEMS(fp)); if (!f) return; if (fstat(fileno(f), &st)) { g_warning("%s(): fstat() failed: %m", G_STRFUNC); fclose(f); return; } while (fgets(line, sizeof line, f)) { pslist_t *sl_addr, *sl; const char *endptr, *start; host_addr_t addr; uint16 port; uint8 bits; bool item_ok; bool use_tls; char *hname; linenum++; if (!file_line_chomp_tail(line, sizeof line, NULL)) { g_warning("%s(): line %u too long, aborting", G_STRFUNC, linenum); break; } if (file_line_is_skipable(line)) continue; sl_addr = NULL; addr = zero_host_addr; endptr = NULL; hname = NULL; endptr = is_strprefix(line, "tls:"); if (endptr) { use_tls = TRUE; start = endptr; } else { use_tls = FALSE; start = line; } port = 0; if (string_to_host_addr_port(start, &endptr, &addr, &port)) { sl_addr = name_to_host_addr(host_addr_to_string(addr), settings_dns_net()); } else if (string_to_host_or_addr(start, &endptr, &addr)) { uchar c = *endptr; switch (c) { case '\0': case ':': case '/': break; default: if (!is_ascii_space(c)) endptr = NULL; } if (!endptr) { g_warning("%s(): line %d: " "expected a hostname or IP address \"%s\"", G_STRFUNC, linenum, line); continue; } /* Terminate the string for name_to_host_addr() */ hname = h_strndup(start, endptr - start); } else { g_warning("%s(): line %d: expected hostname or IP address \"%s\"", G_STRFUNC, linenum, line); continue; } g_assert(sl_addr != NULL || hname != NULL); g_assert(NULL != endptr); bits = 0; item_ok = TRUE; /* * When an explicit address is given (no hostname) and with no * port, one can suffix the address with bits to indicate a CIDR * range of whitelisted addresses. */ if (0 == port) { /* Ignore trailing items separated by a space */ while ('\0' != *endptr && !is_ascii_space(*endptr)) { uchar c = *endptr++; if (':' == c) { int error; uint32 v; if (0 != port) { g_warning("%s(): line %d: multiple colons after host", G_STRFUNC, linenum); item_ok = FALSE; break; } v = parse_uint32(endptr, &endptr, 10, &error); port = (error || v > 0xffff) ? 0 : v; if (0 == port) { g_warning("%s(): line %d: " "invalid port value after host", G_STRFUNC, linenum); item_ok = FALSE; break; } } else if ('/' == c) { const char *ep; uint32 mask; if (0 != bits) { g_warning("%s(): line %d: " "multiple slashes after host", G_STRFUNC, linenum); item_ok = FALSE; break; } if (string_to_ip_strict(endptr, &mask, &ep)) { if (!host_addr_is_ipv4(addr)) { g_warning("%s(): line %d: " "IPv4 netmask after non-IPv4 address", G_STRFUNC, linenum); item_ok = FALSE; break; } endptr = ep; if (0 == (bits = netmask_to_cidr(mask))) { g_warning("%s(): line %d: " "IPv4 netmask after non-IPv4 address", G_STRFUNC, linenum); item_ok = FALSE; break; } } else { int error; uint32 v; v = parse_uint32(endptr, &endptr, 10, &error); if ( error || 0 == v || (v > 32 && host_addr_is_ipv4(addr)) || (v > 128 && host_addr_is_ipv6(addr)) ) { g_warning("%s(): line %d: " "invalid numeric netmask after host", G_STRFUNC, linenum); item_ok = FALSE; break; } bits = v; } } else { g_warning("%s(): line %d: " "unexpected character after host", G_STRFUNC, linenum); item_ok = FALSE; break; } } } if (item_ok) { struct whitelist *item; if (hname) { item = whitelist_hostname_create(use_tls, hname, port); whitelist_dns_resolve(item, FALSE); } else { PSLIST_FOREACH(sl_addr, sl) { host_addr_t *aptr = sl->data; g_assert(aptr != NULL); item = whitelist_addr_create(use_tls, *aptr, port, bits); whitelist_add(item); } } } else {
/* adns interface functions (UI -> Core)*/ gboolean guc_adns_resolve(const char *hostname, adns_callback_t user_callback, gpointer user_data) { return adns_resolve(hostname, settings_dns_net(), user_callback, user_data); }