/* * libwebsockets - small server side websockets and web server implementation * * Copyright (C) 2010-2018 Andy Green <andy@warmcat.com> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation: * version 2.1 of the License. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301 USA */ #include <core/private.h> /* * In-place str to lower case */ static void strtolower(char *s) { while (*s) { #ifdef LWS_PLAT_OPTEE int tolower_optee(int c); *s = tolower_optee((int)*s); #else *s = tolower((int)*s); #endif s++; } } int lws_create_client_ws_object(struct lws_client_connect_info *i, struct lws *wsi) { int v = SPEC_LATEST_SUPPORTED; /* allocate the ws struct for the wsi */ wsi->ws = lws_zalloc(sizeof(*wsi->ws), "client ws struct"); if (!wsi->ws) { lwsl_notice("OOM\n"); return 1; } /* -1 means just use latest supported */ if (i->ietf_version_or_minus_one != -1 && i->ietf_version_or_minus_one) v = i->ietf_version_or_minus_one; wsi->ws->ietf_spec_revision = v; return 0; } #if !defined(LWS_NO_CLIENT) int lws_ws_handshake_client(struct lws *wsi, unsigned char **buf, size_t len) { if ((lwsi_state(wsi) != LRS_WAITING_PROXY_REPLY) && (lwsi_state(wsi) != LRS_H1C_ISSUE_HANDSHAKE) && (lwsi_state(wsi) != LRS_WAITING_SERVER_REPLY) && !lwsi_role_client(wsi)) return 0; // lwsl_notice("%s: hs client gets %d in\n", __func__, (int)len); while (len) { /* * we were accepting input but now we stopped doing so */ if (lws_is_flowcontrolled(wsi)) { //lwsl_notice("%s: caching %ld\n", __func__, (long)len); lws_rxflow_cache(wsi, *buf, 0, (int)len); *buf += len; return 0; } #if !defined(LWS_WITHOUT_EXTENSIONS) if (wsi->ws->rx_draining_ext) { int m; //lwsl_notice("%s: draining ext\n", __func__); if (lwsi_role_client(wsi)) m = lws_ws_client_rx_sm(wsi, 0); else m = lws_ws_rx_sm(wsi, 0, 0); if (m < 0) return -1; continue; } #endif /* caller will account for buflist usage */ if (lws_ws_client_rx_sm(wsi, *(*buf)++)) { lwsl_notice("%s: client_rx_sm exited, DROPPING %d\n", __func__, (int)len); return -1; } len--; } // lwsl_notice("%s: finished with %ld\n", __func__, (long)len); return 0; } #endif char * lws_generate_client_ws_handshake(struct lws *wsi, char *p) { char buf[128], hash[20], key_b64[40]; int n; #if !defined(LWS_WITHOUT_EXTENSIONS) const struct lws_extension *ext; int ext_count = 0; #endif /* * create the random key */ n = lws_get_random(wsi->context, hash, 16); if (n != 16) { lwsl_err("Unable to read from random dev %s\n", SYSTEM_RANDOM_FILEPATH); return NULL; } lws_b64_encode_string(hash, 16, key_b64, sizeof(key_b64)); p += sprintf(p, "Upgrade: websocket\x0d\x0a" "Connection: Upgrade\x0d\x0a" "Sec-WebSocket-Key: "); strcpy(p, key_b64); p += strlen(key_b64); p += sprintf(p, "\x0d\x0a"); if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS)) p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a", lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS)); /* tell the server what extensions we could support */ #if !defined(LWS_WITHOUT_EXTENSIONS) ext = wsi->vhost->ws.extensions; while (ext && ext->callback) { n = wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED, wsi->user_space, (char *)ext->name, 0); /* * zero return from callback means go ahead and allow * the extension, it's what we get if the callback is * unhandled */ if (n) { ext++; continue; } /* apply it */ if (ext_count) *p++ = ','; else p += sprintf(p, "Sec-WebSocket-Extensions: "); p += sprintf(p, "%s", ext->client_offer); ext_count++; ext++; } if (ext_count) p += sprintf(p, "\x0d\x0a"); #endif if (wsi->ws->ietf_spec_revision) p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a", wsi->ws->ietf_spec_revision); /* prepare the expected server accept response */ key_b64[39] = '\0'; /* enforce composed length below buf sizeof */ n = sprintf(buf, "%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11", key_b64); lws_SHA1((unsigned char *)buf, n, (unsigned char *)hash); lws_b64_encode_string(hash, 20, wsi->http.ah->initial_handshake_hash_base64, sizeof(wsi->http.ah->initial_handshake_hash_base64)); return p; } int lws_client_ws_upgrade(struct lws *wsi, const char **cce) { int n, len, okay = 0; struct lws_context *context = wsi->context; const char *pc; char *p; #if !defined(LWS_WITHOUT_EXTENSIONS) struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi]; char *sb = (char *)&pt->serv_buf[0]; const struct lws_ext_options *opts; const struct lws_extension *ext; char ext_name[128]; const char *c, *a; char ignore; int more = 1; #endif if (wsi->client_h2_substream) {/* !!! client ws-over-h2 not there yet */ lwsl_warn("%s: client ws-over-h2 upgrade not supported yet\n", __func__); *cce = "HS: h2 / ws upgrade unsupported"; goto bail3; } if (wsi->http.ah->http_response == 401) { lwsl_warn( "lws_client_handshake: got bad HTTP response '%d'\n", wsi->http.ah->http_response); *cce = "HS: ws upgrade unauthorized"; goto bail3; } if (wsi->http.ah->http_response != 101) { lwsl_warn( "lws_client_handshake: got bad HTTP response '%d'\n", wsi->http.ah->http_response); *cce = "HS: ws upgrade response not 101"; goto bail3; } if (lws_hdr_total_length(wsi, WSI_TOKEN_ACCEPT) == 0) { lwsl_info("no ACCEPT\n"); *cce = "HS: ACCEPT missing"; goto bail3; } p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_UPGRADE); if (!p) { lwsl_info("no UPGRADE\n"); *cce = "HS: UPGRADE missing"; goto bail3; } strtolower(p); if (strcmp(p, "websocket")) { lwsl_warn( "lws_client_handshake: got bad Upgrade header '%s'\n", p); *cce = "HS: Upgrade to something other than websocket"; goto bail3; } p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_CONNECTION); if (!p) { lwsl_info("no Connection hdr\n"); *cce = "HS: CONNECTION missing"; goto bail3; } strtolower(p); if (strcmp(p, "upgrade")) { lwsl_warn("lws_client_int_s_hs: bad header %s\n", p); *cce = "HS: UPGRADE malformed"; goto bail3; } pc = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS); if (!pc) { lwsl_parser("lws_client_int_s_hs: no protocol list\n"); } else lwsl_parser("lws_client_int_s_hs: protocol list '%s'\n", pc); /* * confirm the protocol the server wants to talk was in the list * of protocols we offered */ len = lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL); if (!len) { lwsl_info("%s: WSI_TOKEN_PROTOCOL is null\n", __func__); /* * no protocol name to work from, * default to first protocol */ n = 0; wsi->protocol = &wsi->vhost->protocols[0]; goto check_extensions; } p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL); len = (int)strlen(p); while (pc && *pc && !okay) { if (!strncmp(pc, p, len) && (pc[len] == ',' || pc[len] == '\0')) { okay = 1; continue; } while (*pc && *pc++ != ',') ; while (*pc && *pc == ' ') pc++; } if (!okay) { lwsl_info("%s: got bad protocol %s\n", __func__, p); *cce = "HS: PROTOCOL malformed"; goto bail2; } /* * identify the selected protocol struct and set it */ n = 0; /* keep client connection pre-bound protocol */ if (!lwsi_role_client(wsi)) wsi->protocol = NULL; while (wsi->vhost->protocols[n].callback) { if (!wsi->protocol && strcmp(p, wsi->vhost->protocols[n].name) == 0) { wsi->protocol = &wsi->vhost->protocols[n]; break; } n++; } if (!wsi->vhost->protocols[n].callback) { /* no match */ /* if server, that's already fatal */ if (!lwsi_role_client(wsi)) { lwsl_info("%s: fail protocol %s\n", __func__, p); *cce = "HS: Cannot match protocol"; goto bail2; } /* for client, find the index of our pre-bound protocol */ n = 0; while (wsi->vhost->protocols[n].callback) { if (wsi->protocol && strcmp(wsi->protocol->name, wsi->vhost->protocols[n].name) == 0) { wsi->protocol = &wsi->vhost->protocols[n]; break; } n++; } if (!wsi->vhost->protocols[n].callback) { if (wsi->protocol) lwsl_err("Failed to match protocol %s\n", wsi->protocol->name); else lwsl_err("No protocol on client\n"); goto bail2; } } lwsl_debug("Selected protocol %s\n", wsi->protocol->name); check_extensions: /* * stitch protocol choice into the vh protocol linked list * We always insert ourselves at the start of the list * * X <-> B * X <-> pAn <-> pB */ lws_vhost_lock(wsi->vhost); wsi->same_vh_protocol_prev = /* guy who points to us */ &wsi->vhost->same_vh_protocol_list[n]; wsi->same_vh_protocol_next = /* old first guy is our next */ wsi->vhost->same_vh_protocol_list[n]; /* we become the new first guy */ wsi->vhost->same_vh_protocol_list[n] = wsi; if (wsi->same_vh_protocol_next) /* old first guy points back to us now */ wsi->same_vh_protocol_next->same_vh_protocol_prev = &wsi->same_vh_protocol_next; wsi->on_same_vh_list = 1; lws_vhost_unlock(wsi->vhost); #if !defined(LWS_WITHOUT_EXTENSIONS) /* instantiate the accepted extensions */ if (!lws_hdr_total_length(wsi, WSI_TOKEN_EXTENSIONS)) { lwsl_ext("no client extensions allowed by server\n"); goto check_accept; } /* * break down the list of server accepted extensions * and go through matching them or identifying bogons */ if (lws_hdr_copy(wsi, sb, context->pt_serv_buf_size, WSI_TOKEN_EXTENSIONS) < 0) { lwsl_warn("ext list from server failed to copy\n"); *cce = "HS: EXT: list too big"; goto bail2; } c = sb; n = 0; ignore = 0; a = NULL; while (more) { if (*c && (*c != ',' && *c != '\t')) { if (*c == ';') { ignore = 1; if (!a) a = c + 1; } if (ignore || *c == ' ') { c++; continue; } ext_name[n] = *c++; if (n < (int)sizeof(ext_name) - 1) n++; continue; } ext_name[n] = '\0'; ignore = 0; if (!*c) more = 0; else { c++; if (!n) continue; } /* check we actually support it */ lwsl_notice("checking client ext %s\n", ext_name); n = 0; ext = wsi->vhost->ws.extensions; while (ext && ext->callback) { if (strcmp(ext_name, ext->name)) { ext++; continue; } n = 1; lwsl_notice("instantiating client ext %s\n", ext_name); /* instantiate the extension on this conn */ wsi->ws->active_extensions[wsi->ws->count_act_ext] = ext; /* allow him to construct his ext instance */ if (ext->callback(lws_get_context(wsi), ext, wsi, LWS_EXT_CB_CLIENT_CONSTRUCT, (void *)&wsi->ws->act_ext_user[wsi->ws->count_act_ext], (void *)&opts, 0)) { lwsl_info(" ext %s failed construction\n", ext_name); ext++; continue; } /* * allow the user code to override ext defaults if it * wants to */ ext_name[0] = '\0'; if (user_callback_handle_rxflow(wsi->protocol->callback, wsi, LWS_CALLBACK_WS_EXT_DEFAULTS, (char *)ext->name, ext_name, sizeof(ext_name))) { *cce = "HS: EXT: failed setting defaults"; goto bail2; } if (ext_name[0] && lws_ext_parse_options(ext, wsi, wsi->ws->act_ext_user[ wsi->ws->count_act_ext], opts, ext_name, (int)strlen(ext_name))) { lwsl_err("%s: unable to parse user defaults '%s'", __func__, ext_name); *cce = "HS: EXT: failed parsing defaults"; goto bail2; } /* * give the extension the server options */ if (a && lws_ext_parse_options(ext, wsi, wsi->ws->act_ext_user[wsi->ws->count_act_ext], opts, a, lws_ptr_diff(c, a))) { lwsl_err("%s: unable to parse remote def '%s'", __func__, a); *cce = "HS: EXT: failed parsing options"; goto bail2; } if (ext->callback(lws_get_context(wsi), ext, wsi, LWS_EXT_CB_OPTION_CONFIRM, wsi->ws->act_ext_user[wsi->ws->count_act_ext], NULL, 0)) { lwsl_err("%s: ext %s rejects server options %s", __func__, ext->name, a); *cce = "HS: EXT: Rejects server options"; goto bail2; } wsi->ws->count_act_ext++; ext++; } if (n == 0) { lwsl_warn("Unknown ext '%s'!\n", ext_name); *cce = "HS: EXT: unknown ext"; goto bail2; } a = NULL; n = 0; } check_accept: #endif /* * Confirm his accept token is the one we precomputed */ p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_ACCEPT); if (strcmp(p, wsi->http.ah->initial_handshake_hash_base64)) { lwsl_warn("lws_client_int_s_hs: accept '%s' wrong vs '%s'\n", p, wsi->http.ah->initial_handshake_hash_base64); *cce = "HS: Accept hash wrong"; goto bail2; } /* allocate the per-connection user memory (if any) */ if (lws_ensure_user_space(wsi)) { lwsl_err("Problem allocating wsi user mem\n"); *cce = "HS: OOM"; goto bail2; } /* * we seem to be good to go, give client last chance to check * headers and OK it */ if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH, wsi->user_space, NULL, 0)) { *cce = "HS: Rejected by filter cb"; goto bail2; } /* clear his proxy connection timeout */ lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0); /* free up his parsing allocations */ lws_header_table_detach(wsi, 0); lws_role_transition(wsi, LWSIFR_CLIENT, LRS_ESTABLISHED, &role_ops_ws); lws_restart_ws_ping_pong_timer(wsi); wsi->rxflow_change_to = LWS_RXFLOW_ALLOW; /* * create the frame buffer for this connection according to the * size mentioned in the protocol definition. If 0 there, then * use a big default for compatibility */ n = (int)wsi->protocol->rx_buffer_size; if (!n) n = context->pt_serv_buf_size; n += LWS_PRE; wsi->ws->rx_ubuf = lws_malloc(n + 4 /* 0x0000ffff zlib */, "client frame buffer"); if (!wsi->ws->rx_ubuf) { lwsl_err("Out of Mem allocating rx buffer %d\n", n); *cce = "HS: OOM"; goto bail2; } wsi->ws->rx_ubuf_alloc = n; lwsl_info("Allocating client RX buffer %d\n", n); #if !defined(LWS_WITH_ESP32) if (setsockopt(wsi->desc.sockfd, SOL_SOCKET, SO_SNDBUF, (const char *)&n, sizeof n)) { lwsl_warn("Failed to set SNDBUF to %d", n); *cce = "HS: SO_SNDBUF failed"; goto bail3; } #endif lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name); /* call him back to inform him he is up */ if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_ESTABLISHED, wsi->user_space, NULL, 0)) { *cce = "HS: Rejected at CLIENT_ESTABLISHED"; goto bail3; } return 0; bail3: return 3; bail2: return 2; }