| /* |
| * libwebsockets - small server side websockets and web server implementation |
| * |
| * Copyright (C) 2010-2013 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 "private-libwebsockets.h" |
| |
| #ifdef WIN32 |
| #include <io.h> |
| #endif |
| |
| static int |
| libwebsocket_0405_frame_mask_generate(struct libwebsocket *wsi) |
| { |
| int n; |
| |
| /* fetch the per-frame nonce */ |
| |
| n = libwebsockets_get_random(wsi->protocol->owning_server, |
| wsi->u.ws.frame_masking_nonce_04, 4); |
| if (n != 4) { |
| lwsl_parser("Unable to read from random device %s %d\n", |
| SYSTEM_RANDOM_FILEPATH, n); |
| return 1; |
| } |
| |
| /* start masking from first byte of masking key buffer */ |
| wsi->u.ws.frame_mask_index = 0; |
| |
| return 0; |
| } |
| |
| #ifdef _DEBUG |
| |
| void lwsl_hexdump(void *vbuf, size_t len) |
| { |
| int n; |
| int m; |
| int start; |
| unsigned char *buf = (unsigned char *)vbuf; |
| char line[80]; |
| char *p; |
| |
| lwsl_parser("\n"); |
| |
| for (n = 0; n < len;) { |
| start = n; |
| p = line; |
| |
| p += sprintf(p, "%04X: ", start); |
| |
| for (m = 0; m < 16 && n < len; m++) |
| p += sprintf(p, "%02X ", buf[n++]); |
| while (m++ < 16) |
| p += sprintf(p, " "); |
| |
| p += sprintf(p, " "); |
| |
| for (m = 0; m < 16 && (start + m) < len; m++) { |
| if (buf[start + m] >= ' ' && buf[start + m] < 127) |
| *p++ = buf[start + m]; |
| else |
| *p++ = '.'; |
| } |
| while (m++ < 16) |
| *p++ = ' '; |
| |
| *p++ = '\n'; |
| *p = '\0'; |
| lwsl_debug("%s", line); |
| } |
| lwsl_debug("\n"); |
| } |
| |
| #endif |
| |
| /* |
| * notice this returns number of bytes sent, or -1 |
| */ |
| |
| int lws_issue_raw(struct libwebsocket *wsi, unsigned char *buf, size_t len) |
| { |
| struct libwebsocket_context *context = wsi->protocol->owning_server; |
| int n; |
| #ifndef LWS_NO_EXTENSIONS |
| int m; |
| |
| /* |
| * one of the extensions is carrying our data itself? Like mux? |
| */ |
| |
| for (n = 0; n < wsi->count_active_extensions; n++) { |
| /* |
| * there can only be active extensions after handshake completed |
| * so we can rely on protocol being set already in here |
| */ |
| m = wsi->active_extensions[n]->callback( |
| wsi->protocol->owning_server, |
| wsi->active_extensions[n], wsi, |
| LWS_EXT_CALLBACK_PACKET_TX_DO_SEND, |
| wsi->active_extensions_user[n], &buf, len); |
| if (m < 0) { |
| lwsl_ext("Extension reports fatal error\n"); |
| return -1; |
| } |
| if (m) /* handled */ { |
| /* lwsl_ext("ext sent it\n"); */ |
| return m; |
| } |
| } |
| #endif |
| if (!wsi->sock) |
| lwsl_warn("** error 0 sock but expected to send\n"); |
| |
| /* |
| * nope, send it on the socket directly |
| */ |
| |
| #if 0 |
| lwsl_debug(" TX: "); |
| lws_hexdump(buf, len); |
| #endif |
| |
| lws_latency_pre(context, wsi); |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (wsi->ssl) { |
| n = SSL_write(wsi->ssl, buf, len); |
| lws_latency(context, wsi, "SSL_write lws_issue_raw", n, n >= 0); |
| if (n < 0) { |
| lwsl_debug("ERROR writing to socket\n"); |
| return -1; |
| } |
| } else { |
| #endif |
| n = send(wsi->sock, buf, len, MSG_NOSIGNAL); |
| lws_latency(context, wsi, "send lws_issue_raw", n, n == len); |
| if (n < 0) { |
| lwsl_debug("ERROR writing len %d to skt %d\n", len, n); |
| return -1; |
| } |
| #ifdef LWS_OPENSSL_SUPPORT |
| } |
| #endif |
| return n; |
| } |
| |
| #ifdef LWS_NO_EXTENSIONS |
| int |
| lws_issue_raw_ext_access(struct libwebsocket *wsi, |
| unsigned char *buf, size_t len) |
| { |
| return lws_issue_raw(wsi, buf, len); |
| } |
| #else |
| int |
| lws_issue_raw_ext_access(struct libwebsocket *wsi, |
| unsigned char *buf, size_t len) |
| { |
| int ret; |
| struct lws_tokens eff_buf; |
| int m; |
| int n; |
| |
| eff_buf.token = (char *)buf; |
| eff_buf.token_len = len; |
| |
| /* |
| * while we have original buf to spill ourselves, or extensions report |
| * more in their pipeline |
| */ |
| |
| ret = 1; |
| while (ret == 1) { |
| |
| /* default to nobody has more to spill */ |
| |
| ret = 0; |
| |
| /* show every extension the new incoming data */ |
| |
| for (n = 0; n < wsi->count_active_extensions; n++) { |
| m = wsi->active_extensions[n]->callback( |
| wsi->protocol->owning_server, |
| wsi->active_extensions[n], wsi, |
| LWS_EXT_CALLBACK_PACKET_TX_PRESEND, |
| wsi->active_extensions_user[n], &eff_buf, 0); |
| if (m < 0) { |
| lwsl_ext("Extension: fatal error\n"); |
| return -1; |
| } |
| if (m) |
| /* |
| * at least one extension told us he has more |
| * to spill, so we will go around again after |
| */ |
| ret = 1; |
| } |
| |
| /* assuming they left us something to send, send it */ |
| |
| if (eff_buf.token_len) { |
| n = lws_issue_raw(wsi, (unsigned char *)eff_buf.token, |
| eff_buf.token_len); |
| if (n < 0) |
| return -1; |
| /* |
| * Keep amount spilled small to minimize chance of this |
| */ |
| if (n != eff_buf.token_len) { |
| lwsl_err("Unable to spill ext %d vs %d\n", |
| eff_buf.token_len, n); |
| return -1; |
| } |
| |
| } |
| |
| lwsl_parser("written %d bytes to client\n", eff_buf.token_len); |
| |
| /* no extension has more to spill */ |
| |
| if (!ret) |
| break; |
| |
| /* we used up what we had */ |
| |
| eff_buf.token = NULL; |
| eff_buf.token_len = 0; |
| |
| /* |
| * Did that leave the pipe choked? |
| */ |
| |
| if (!lws_send_pipe_choked(wsi)) |
| /* no we could add more */ |
| continue; |
| |
| lwsl_debug("choked\n"); |
| |
| /* |
| * Yes, he's choked. Don't spill the rest now get a callback |
| * when he is ready to send and take care of it there |
| */ |
| libwebsocket_callback_on_writable( |
| wsi->protocol->owning_server, wsi); |
| wsi->extension_data_pending = 1; |
| ret = 0; |
| } |
| |
| return len; |
| } |
| #endif |
| |
| /** |
| * libwebsocket_write() - Apply protocol then write data to client |
| * @wsi: Websocket instance (available from user callback) |
| * @buf: The data to send. For data being sent on a websocket |
| * connection (ie, not default http), this buffer MUST have |
| * LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer |
| * and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid |
| * in the buffer after (buf + len). This is so the protocol |
| * header and trailer data can be added in-situ. |
| * @len: Count of the data bytes in the payload starting from buf |
| * @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one |
| * of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate |
| * data on a websockets connection. Remember to allow the extra |
| * bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT |
| * are used. |
| * |
| * This function provides the way to issue data back to the client |
| * for both http and websocket protocols. |
| * |
| * In the case of sending using websocket protocol, be sure to allocate |
| * valid storage before and after buf as explained above. This scheme |
| * allows maximum efficiency of sending data and protocol in a single |
| * packet while not burdening the user code with any protocol knowledge. |
| * |
| * Return may be -1 for a fatal error needing connection close, or a |
| * positive number reflecting the amount of bytes actually sent. This |
| * can be less than the requested number of bytes due to OS memory |
| * pressure at any given time. |
| */ |
| |
| int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf, |
| size_t len, enum libwebsocket_write_protocol protocol) |
| { |
| int n; |
| int pre = 0; |
| int post = 0; |
| int masked7 = wsi->mode == LWS_CONNMODE_WS_CLIENT; |
| unsigned char *dropmask = NULL; |
| unsigned char is_masked_bit = 0; |
| size_t orig_len = len; |
| #ifndef LWS_NO_EXTENSIONS |
| struct lws_tokens eff_buf; |
| int m; |
| #endif |
| |
| if (len == 0 && protocol != LWS_WRITE_CLOSE) { |
| lwsl_warn("zero length libwebsocket_write attempt\n"); |
| return 0; |
| } |
| |
| if (protocol == LWS_WRITE_HTTP) |
| goto send_raw; |
| |
| /* websocket protocol, either binary or text */ |
| |
| if (wsi->state != WSI_STATE_ESTABLISHED) |
| return -1; |
| |
| #ifndef LWS_NO_EXTENSIONS |
| /* give a change to the extensions to modify payload */ |
| eff_buf.token = (char *)buf; |
| eff_buf.token_len = len; |
| |
| switch (protocol) { |
| case LWS_WRITE_PING: |
| case LWS_WRITE_PONG: |
| case LWS_WRITE_CLOSE: |
| break; |
| default: |
| |
| for (n = 0; n < wsi->count_active_extensions; n++) { |
| m = wsi->active_extensions[n]->callback( |
| wsi->protocol->owning_server, |
| wsi->active_extensions[n], wsi, |
| LWS_EXT_CALLBACK_PAYLOAD_TX, |
| wsi->active_extensions_user[n], &eff_buf, 0); |
| if (m < 0) |
| return -1; |
| } |
| } |
| |
| buf = (unsigned char *)eff_buf.token; |
| len = eff_buf.token_len; |
| #endif |
| |
| switch (wsi->ietf_spec_revision) { |
| case 13: |
| if (masked7) { |
| pre += 4; |
| dropmask = &buf[0 - pre]; |
| is_masked_bit = 0x80; |
| } |
| |
| switch (protocol & 0xf) { |
| case LWS_WRITE_TEXT: |
| n = LWS_WS_OPCODE_07__TEXT_FRAME; |
| break; |
| case LWS_WRITE_BINARY: |
| n = LWS_WS_OPCODE_07__BINARY_FRAME; |
| break; |
| case LWS_WRITE_CONTINUATION: |
| n = LWS_WS_OPCODE_07__CONTINUATION; |
| break; |
| |
| case LWS_WRITE_CLOSE: |
| n = LWS_WS_OPCODE_07__CLOSE; |
| |
| /* |
| * 06+ has a 2-byte status code in network order |
| * we can do this because we demand post-buf |
| */ |
| |
| if (wsi->u.ws.close_reason) { |
| /* reason codes count as data bytes */ |
| buf -= 2; |
| buf[0] = wsi->u.ws.close_reason >> 8; |
| buf[1] = wsi->u.ws.close_reason; |
| len += 2; |
| } |
| break; |
| case LWS_WRITE_PING: |
| n = LWS_WS_OPCODE_07__PING; |
| break; |
| case LWS_WRITE_PONG: |
| n = LWS_WS_OPCODE_07__PONG; |
| break; |
| default: |
| lwsl_warn("lws_write: unknown write opc / protocol\n"); |
| return -1; |
| } |
| |
| if (!(protocol & LWS_WRITE_NO_FIN)) |
| n |= 1 << 7; |
| |
| if (len < 126) { |
| pre += 2; |
| buf[-pre] = n; |
| buf[-pre + 1] = len | is_masked_bit; |
| } else { |
| if (len < 65536) { |
| pre += 4; |
| buf[-pre] = n; |
| buf[-pre + 1] = 126 | is_masked_bit; |
| buf[-pre + 2] = len >> 8; |
| buf[-pre + 3] = len; |
| } else { |
| pre += 10; |
| buf[-pre] = n; |
| buf[-pre + 1] = 127 | is_masked_bit; |
| #if defined __LP64__ |
| buf[-pre + 2] = (len >> 56) & 0x7f; |
| buf[-pre + 3] = len >> 48; |
| buf[-pre + 4] = len >> 40; |
| buf[-pre + 5] = len >> 32; |
| #else |
| buf[-pre + 2] = 0; |
| buf[-pre + 3] = 0; |
| buf[-pre + 4] = 0; |
| buf[-pre + 5] = 0; |
| #endif |
| buf[-pre + 6] = len >> 24; |
| buf[-pre + 7] = len >> 16; |
| buf[-pre + 8] = len >> 8; |
| buf[-pre + 9] = len; |
| } |
| } |
| break; |
| } |
| |
| /* |
| * Deal with masking if we are in client -> server direction and |
| * the protocol demands it |
| */ |
| |
| if (wsi->mode == LWS_CONNMODE_WS_CLIENT) { |
| |
| if (libwebsocket_0405_frame_mask_generate(wsi)) { |
| lwsl_err("lws_write: frame mask generation failed\n"); |
| return -1; |
| } |
| |
| /* |
| * in v7, just mask the payload |
| */ |
| for (n = 4; n < (int)len + 4; n++) |
| dropmask[n] = dropmask[n] ^ |
| wsi->u.ws.frame_masking_nonce_04[ |
| (wsi->u.ws.frame_mask_index++) & 3]; |
| |
| if (dropmask) |
| /* copy the frame nonce into place */ |
| memcpy(dropmask, |
| wsi->u.ws.frame_masking_nonce_04, 4); |
| } |
| |
| send_raw: |
| |
| #if 0 |
| lwsl_debug("send %ld: ", len + post); |
| lwsl_hexdump(&buf[-pre], len + post); |
| #endif |
| |
| switch (protocol) { |
| case LWS_WRITE_CLOSE: |
| /* lwsl_hexdump(&buf[-pre], len + post); */ |
| case LWS_WRITE_HTTP: |
| case LWS_WRITE_PONG: |
| case LWS_WRITE_PING: |
| return lws_issue_raw(wsi, (unsigned char *)buf - pre, |
| len + pre + post); |
| default: |
| break; |
| } |
| |
| /* |
| * give any active extensions a chance to munge the buffer |
| * before send. We pass in a pointer to an lws_tokens struct |
| * prepared with the default buffer and content length that's in |
| * there. Rather than rewrite the default buffer, extensions |
| * that expect to grow the buffer can adapt .token to |
| * point to their own per-connection buffer in the extension |
| * user allocation. By default with no extensions or no |
| * extension callback handling, just the normal input buffer is |
| * used then so it is efficient. |
| * |
| * callback returns 1 in case it wants to spill more buffers |
| */ |
| |
| n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post); |
| if (n < 0) |
| return n; |
| |
| return orig_len - ((len - pre + post) -n ); |
| } |
| |
| int libwebsockets_serve_http_file_fragment( |
| struct libwebsocket_context *context, struct libwebsocket *wsi) |
| { |
| int ret = 0; |
| int n, m; |
| |
| while (!lws_send_pipe_choked(wsi)) { |
| n = read(wsi->u.http.fd, context->service_buffer, |
| sizeof(context->service_buffer)); |
| if (n > 0) { |
| m = libwebsocket_write(wsi, context->service_buffer, n, |
| LWS_WRITE_HTTP); |
| if (m < 0) |
| return -1; |
| |
| wsi->u.http.filepos += n; |
| if (m != n) |
| /* adjust for what was not sent */ |
| lseek(wsi->u.http.fd, m - n, SEEK_CUR); |
| } |
| |
| if (n < 0) |
| return -1; /* caller will close */ |
| |
| if (n < sizeof(context->service_buffer) || |
| wsi->u.http.filepos == wsi->u.http.filelen) { |
| wsi->state = WSI_STATE_HTTP; |
| |
| if (wsi->protocol->callback) |
| ret = user_callback_handle_rxflow( |
| wsi->protocol->callback, context, wsi, |
| LWS_CALLBACK_HTTP_FILE_COMPLETION, |
| wsi->user_space, NULL, 0); |
| return ret; |
| } |
| } |
| |
| lwsl_notice("choked before able to send whole file (post)\n"); |
| libwebsocket_callback_on_writable(context, wsi); |
| |
| return ret; |
| } |
| |
| /** |
| * libwebsockets_serve_http_file() - Send a file back to the client using http |
| * @context: libwebsockets context |
| * @wsi: Websocket instance (available from user callback) |
| * @file: The file to issue over http |
| * @content_type: The http content type, eg, text/html |
| * |
| * This function is intended to be called from the callback in response |
| * to http requests from the client. It allows the callback to issue |
| * local files down the http link in a single step. |
| * |
| * Returning <0 indicates error and the wsi should be closed. Returning |
| * >0 indicates the file was completely sent and the wsi should be closed. |
| * ==0 indicates the file transfer is started and needs more service later, |
| * the wsi should be left alone. |
| */ |
| |
| int libwebsockets_serve_http_file(struct libwebsocket_context *context, |
| struct libwebsocket *wsi, const char *file, |
| const char *content_type) |
| { |
| struct stat stat_buf; |
| unsigned char *p = context->service_buffer; |
| int ret = 0; |
| |
| wsi->u.http.fd = open(file, O_RDONLY |
| #ifdef WIN32 |
| | _O_BINARY |
| #endif |
| ); |
| |
| if (wsi->u.http.fd < 1) { |
| p += sprintf((char *)p, |
| "HTTP/1.0 400 Bad\x0d\x0aServer: libwebsockets\x0d\x0a\x0d\x0a" |
| ); |
| wsi->u.http.fd = 0; |
| /* too small to care about partial, closing anyway */ |
| libwebsocket_write(wsi, context->service_buffer, |
| p - context->service_buffer, LWS_WRITE_HTTP); |
| |
| return -1; |
| } |
| |
| fstat(wsi->u.http.fd, &stat_buf); |
| wsi->u.http.filelen = stat_buf.st_size; |
| p += sprintf((char *)p, |
| "HTTP/1.0 200 OK\x0d\x0aServer: libwebsockets\x0d\x0a""Content-Type: %s\x0d\x0a", |
| content_type); |
| p += sprintf((char *)p, |
| "Content-Length: %u\x0d\x0a\x0d\x0a", |
| (unsigned int)stat_buf.st_size); |
| |
| ret = libwebsocket_write(wsi, context->service_buffer, |
| p - context->service_buffer, LWS_WRITE_HTTP); |
| if (ret != (p - context->service_buffer)) { |
| lwsl_err("_write returned %d from %d\n", ret, (p - context->service_buffer)); |
| return -1; |
| } |
| |
| wsi->u.http.filepos = 0; |
| wsi->state = WSI_STATE_HTTP_ISSUING_FILE; |
| |
| return libwebsockets_serve_http_file_fragment(context, wsi); |
| } |
| |