diff options
Diffstat (limited to 'mqtt_websockets/src/ws_client.c')
| -rw-r--r-- | mqtt_websockets/src/ws_client.c | 744 |
1 files changed, 744 insertions, 0 deletions
diff --git a/mqtt_websockets/src/ws_client.c b/mqtt_websockets/src/ws_client.c new file mode 100644 index 00000000..47f633e7 --- /dev/null +++ b/mqtt_websockets/src/ws_client.c @@ -0,0 +1,744 @@ +// Copyright (C) 2020 Timotej Šiškovič +// SPDX-License-Identifier: GPL-3.0-only +// +// This program is free software: you can redistribute it and/or modify it +// under the terms of the GNU General Public License as published by the Free Software Foundation, version 3. +// +// This program 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 General Public License for more details. +// +// You should have received a copy of the GNU General Public License along with this program. +// If not, see <https://www.gnu.org/licenses/>. + +#include <fcntl.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <ctype.h> + +#include <openssl/evp.h> + +#include "ws_client.h" +#include "common_internal.h" + +#ifdef MQTT_WEBSOCKETS_DEBUG +#include "../c-rbuf/src/ringbuffer_internal.h" +#endif + +#define UNIT_LOG_PREFIX "ws_client: " +#define FATAL(fmt, ...) mws_fatal(client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define ERROR(fmt, ...) mws_error(client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define WARN(fmt, ...) mws_warn (client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define INFO(fmt, ...) mws_info (client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define DEBUG(fmt, ...) mws_debug(client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) + +const char *websocket_upgrage_hdr = "GET /mqtt HTTP/1.1\x0D\x0A" + "Host: %s\x0D\x0A" + "Upgrade: websocket\x0D\x0A" + "Connection: Upgrade\x0D\x0A" + "Sec-WebSocket-Key: %s\x0D\x0A" + "Origin: http://example.com\x0D\x0A" + "Sec-WebSocket-Protocol: mqtt\x0D\x0A" + "Sec-WebSocket-Version: 13\x0D\x0A\x0D\x0A"; + +const char *mqtt_protoid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; + +#define DEFAULT_RINGBUFFER_SIZE (1024*128) +#define ENTROPY_SOURCE "/dev/urandom" +ws_client *ws_client_new(size_t buf_size, char **host, mqtt_wss_log_ctx_t log) +{ + ws_client *client; + + if(!host) + return NULL; + + client = mw_calloc(1, sizeof(ws_client)); + if (!client) + return NULL; + + client->host = host; + client->log = log; + + client->buf_read = rbuf_create(buf_size ? buf_size : DEFAULT_RINGBUFFER_SIZE); + if (!client->buf_read) + goto cleanup; + + client->buf_write = rbuf_create(buf_size ? buf_size : DEFAULT_RINGBUFFER_SIZE); + if (!client->buf_write) + goto cleanup_1; + + client->buf_to_mqtt = rbuf_create(buf_size ? buf_size : DEFAULT_RINGBUFFER_SIZE); + if (!client->buf_to_mqtt) + goto cleanup_2; + + client->entropy_fd = open(ENTROPY_SOURCE, O_RDONLY); + if (client->entropy_fd < 1) { + ERROR("Error opening entropy source \"" ENTROPY_SOURCE "\". Reason: \"%s\"", strerror(errno)); + goto cleanup_3; + } + + return client; + +cleanup_3: + rbuf_free(client->buf_to_mqtt); +cleanup_2: + rbuf_free(client->buf_write); +cleanup_1: + rbuf_free(client->buf_read); +cleanup: + mw_free(client); + return NULL; +} + +void ws_client_free_headers(ws_client *client) +{ + struct http_header *ptr = client->hs.headers; + struct http_header *tmp; + + while (ptr) { + tmp = ptr; + ptr = ptr->next; + mw_free(tmp); + } + + client->hs.headers = NULL; + client->hs.headers_tail = NULL; + client->hs.hdr_count = 0; +} + +void ws_client_destroy(ws_client *client) +{ + ws_client_free_headers(client); + mw_free(client->hs.nonce_reply); + mw_free(client->hs.http_reply_msg); + close(client->entropy_fd); + rbuf_free(client->buf_read); + rbuf_free(client->buf_write); + rbuf_free(client->buf_to_mqtt); + mw_free(client); +} + +void ws_client_reset(ws_client *client) +{ + ws_client_free_headers(client); + mw_free(client->hs.nonce_reply); + client->hs.nonce_reply = NULL; + mw_free(client->hs.http_reply_msg); + client->hs.http_reply_msg = NULL; + rbuf_flush(client->buf_read); + rbuf_flush(client->buf_write); + rbuf_flush(client->buf_to_mqtt); + client->state = WS_RAW; + client->hs.hdr_state = WS_HDR_HTTP; + client->rx.parse_state = WS_FIRST_2BYTES; +} + +#define MAX_HTTP_HDR_COUNT 128 +int ws_client_add_http_header(ws_client *client, struct http_header *hdr) +{ + if (client->hs.hdr_count > MAX_HTTP_HDR_COUNT) { + ERROR("Too many HTTP response header fields"); + return -1; + } + + if (client->hs.headers) + client->hs.headers_tail->next = hdr; + else + client->hs.headers = hdr; + + client->hs.headers_tail = hdr; + client->hs.hdr_count++; + + return 0; +} + +int ws_client_want_write(ws_client *client) +{ + return rbuf_bytes_available(client->buf_write); +} + +#define RAND_SRC "/dev/urandom" +static int ws_client_get_nonce(ws_client *client, char *dest, unsigned int size) +{ + // we do not need crypto secure random here + // it's just used for protocol negotiation + int rd; + int f = open(RAND_SRC, O_RDONLY); + if (f < 0) { + ERROR("Error opening \"%s\". Err: \"%s\"", RAND_SRC, strerror(errno)); + return -2; + } + + if ((rd = read(f, dest, size)) > 0) { + close(f); + return rd; + } + close(f); + return -1; +} + +#define WEBSOCKET_NONCE_SIZE 16 +#define TEMP_BUF_SIZE 4096 +int ws_client_start_handshake(ws_client *client) +{ + char nonce[WEBSOCKET_NONCE_SIZE]; + char nonce_b64[256]; + char second[TEMP_BUF_SIZE]; + unsigned int md_len; + unsigned char *digest; + EVP_MD_CTX *md_ctx; + const EVP_MD *md; + + if(!*client->host) { + ERROR("Hostname has not been set. We should not be able to come here!"); + return 1; + } + + ws_client_get_nonce(client, nonce, WEBSOCKET_NONCE_SIZE); + EVP_EncodeBlock((unsigned char *)nonce_b64, (const unsigned char *)nonce, WEBSOCKET_NONCE_SIZE); + snprintf(second, TEMP_BUF_SIZE, websocket_upgrage_hdr, + *client->host, + nonce_b64); + if(rbuf_bytes_free(client->buf_write) < strlen(second)) { + ERROR("Write buffer capacity too low."); + return 1; + } + + rbuf_push(client->buf_write, second, strlen(second)); + client->state = WS_HANDSHAKE; + + //Calculating expected Sec-WebSocket-Accept reply + snprintf(second, TEMP_BUF_SIZE, "%s%s", nonce_b64, mqtt_protoid); + +#if (OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110) + md_ctx = EVP_MD_CTX_create(); +#else + md_ctx = EVP_MD_CTX_new(); +#endif + if (md_ctx == NULL) { + ERROR("Cant create EVP_MD Context"); + return 1; + } + + md = EVP_get_digestbyname("sha1"); + if (!md) { + ERROR("Unknown message digest"); + return 1; + } + + if ((digest = (unsigned char *)OPENSSL_malloc(EVP_MD_size(EVP_sha256()))) == NULL) { + ERROR("Cant alloc digest"); + return 1; + } + + EVP_DigestInit_ex(md_ctx, md, NULL); + EVP_DigestUpdate(md_ctx, second, strlen(second)); + EVP_DigestFinal_ex(md_ctx, digest, &md_len); + + EVP_EncodeBlock((unsigned char *)nonce_b64, digest, md_len); + + mw_free(client->hs.nonce_reply); + client->hs.nonce_reply = mw_strdup(nonce_b64); + + OPENSSL_free(digest); + +#if (OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110) + EVP_MD_CTX_destroy(md_ctx); +#else + EVP_MD_CTX_free(md_ctx); +#endif + + return 0; +} + +#define BUF_READ_MEMCMP_CONST(const, err) \ + if (rbuf_memcmp_n(client->buf_read, const, strlen(const))) { \ + ERROR(err); \ + rbuf_flush(client->buf_read); \ + return WS_CLIENT_PROTOCOL_ERROR; \ + } + +#define BUF_READ_CHECK_AT_LEAST(x) \ + if (rbuf_bytes_available(client->buf_read) < x) \ + return WS_CLIENT_NEED_MORE_BYTES; + +#define MAX_HTTP_LINE_LENGTH 1024*4 +#define HTTP_SC_LENGTH 4 // "XXX " http status code as C string +#define WS_CLIENT_HTTP_HDR "HTTP/1.1 " +#define WS_CONN_ACCEPT "sec-websocket-accept" +#define HTTP_HDR_SEPARATOR ": " +#define WS_NONCE_STRLEN_B64 28 +#define WS_HTTP_NEWLINE "\r\n" +#define HTTP_HEADER_NAME_MAX_LEN 256 +#if HTTP_HEADER_NAME_MAX_LEN > MAX_HTTP_LINE_LENGTH +#error "Buffer too small" +#endif +#if WS_NONCE_STRLEN_B64 > MAX_HTTP_LINE_LENGTH +#error "Buffer too small" +#endif + +#define HTTP_HDR_LINE_CHECK_LIMIT(x) if ((x) >= MAX_HTTP_LINE_LENGTH) \ +{ \ + ERROR("HTTP line received is too long. Maximum is %d", MAX_HTTP_LINE_LENGTH); \ + return WS_CLIENT_PROTOCOL_ERROR; \ +} + +int ws_client_parse_handshake_resp(ws_client *client) +{ + char buf[HTTP_SC_LENGTH]; + int idx_crlf, idx_sep; + char *ptr; + size_t bytes; + switch (client->hs.hdr_state) { + case WS_HDR_HTTP: + BUF_READ_CHECK_AT_LEAST(strlen(WS_CLIENT_HTTP_HDR)) + BUF_READ_MEMCMP_CONST(WS_CLIENT_HTTP_HDR, "Expected \"HTTP1.1\" header"); + rbuf_bump_tail(client->buf_read, strlen(WS_CLIENT_HTTP_HDR)); + client->hs.hdr_state = WS_HDR_RC; + break; + case WS_HDR_RC: + BUF_READ_CHECK_AT_LEAST(HTTP_SC_LENGTH); // "XXX " http return code + rbuf_pop(client->buf_read, buf, HTTP_SC_LENGTH); + if (buf[HTTP_SC_LENGTH - 1] != 0x20) { + ERROR("HTTP status code received is not terminated by space (0x20)"); + return WS_CLIENT_PROTOCOL_ERROR; + } + buf[HTTP_SC_LENGTH - 1] = 0; + client->hs.http_code = atoi(buf); + if (client->hs.http_code < 100 || client->hs.http_code >= 600) { + ERROR("HTTP status code received not in valid range 100-600"); + return WS_CLIENT_PROTOCOL_ERROR; + } + client->hs.hdr_state = WS_HDR_ENDLINE; + break; + case WS_HDR_ENDLINE: + ptr = rbuf_find_bytes(client->buf_read, WS_HTTP_NEWLINE, strlen(WS_HTTP_NEWLINE), &idx_crlf); + if (!ptr) { + bytes = rbuf_bytes_available(client->buf_read); + HTTP_HDR_LINE_CHECK_LIMIT(bytes); + return WS_CLIENT_NEED_MORE_BYTES; + } + HTTP_HDR_LINE_CHECK_LIMIT(idx_crlf); + + client->hs.http_reply_msg = mw_malloc(idx_crlf+1); + rbuf_pop(client->buf_read, client->hs.http_reply_msg, idx_crlf); + client->hs.http_reply_msg[idx_crlf] = 0; + rbuf_bump_tail(client->buf_read, strlen(WS_HTTP_NEWLINE)); + client->hs.hdr_state = WS_HDR_PARSE_HEADERS; + break; + case WS_HDR_PARSE_HEADERS: + ptr = rbuf_find_bytes(client->buf_read, WS_HTTP_NEWLINE, strlen(WS_HTTP_NEWLINE), &idx_crlf); + if (!ptr) { + bytes = rbuf_bytes_available(client->buf_read); + HTTP_HDR_LINE_CHECK_LIMIT(bytes); + return WS_CLIENT_NEED_MORE_BYTES; + } + HTTP_HDR_LINE_CHECK_LIMIT(idx_crlf); + + if (!idx_crlf) { // empty line, header end + rbuf_bump_tail(client->buf_read, strlen(WS_HTTP_NEWLINE)); + client->hs.hdr_state = WS_HDR_PARSE_DONE; + return 0; + } + + ptr = rbuf_find_bytes(client->buf_read, HTTP_HDR_SEPARATOR, strlen(HTTP_HDR_SEPARATOR), &idx_sep); + if (!ptr || idx_sep > idx_crlf) { + ERROR("Expected HTTP hdr field key/value separator \": \" before endline in non empty HTTP header line"); + return WS_CLIENT_PROTOCOL_ERROR; + } + if (idx_crlf == idx_sep + (int)strlen(HTTP_HDR_SEPARATOR)) { + ERROR("HTTP Header value cannot be empty"); + return WS_CLIENT_PROTOCOL_ERROR; + } + + if (idx_sep > HTTP_HEADER_NAME_MAX_LEN) { + ERROR("HTTP header too long (%d)", idx_sep); + return WS_CLIENT_PROTOCOL_ERROR; + } + + struct http_header *hdr = mw_calloc(1, sizeof(struct http_header) + idx_crlf); //idx_crlf includes ": " that will be used as 2 \0 bytes + hdr->key = ((char*)hdr) + sizeof(struct http_header); + hdr->value = hdr->key + idx_sep + 1; + + bytes = rbuf_pop(client->buf_read, hdr->key, idx_sep); + rbuf_bump_tail(client->buf_read, strlen(HTTP_HDR_SEPARATOR)); + + bytes = rbuf_pop(client->buf_read, hdr->value, idx_crlf - idx_sep - strlen(HTTP_HDR_SEPARATOR)); + rbuf_bump_tail(client->buf_read, strlen(WS_HTTP_NEWLINE)); + + for (int i = 0; hdr->key[i]; i++) + hdr->key[i] = tolower(hdr->key[i]); + +// DEBUG("HTTP header \"%s\" received. Value \"%s\"", hdr->key, hdr->value); + + if (ws_client_add_http_header(client, hdr)) + return WS_CLIENT_PROTOCOL_ERROR; + + if (!strcmp(hdr->key, WS_CONN_ACCEPT)) { + if (strcmp(client->hs.nonce_reply, hdr->value)) { + ERROR("Received NONCE \"%s\" does not match expected nonce of \"%s\"", hdr->value, client->hs.nonce_reply); + return WS_CLIENT_PROTOCOL_ERROR; + } + client->hs.nonce_matched = 1; + } + + break; + case WS_HDR_PARSE_DONE: + if (!client->hs.nonce_matched) { + ERROR("Missing " WS_CONN_ACCEPT " header"); + return WS_CLIENT_PROTOCOL_ERROR; + } + if (client->hs.http_code != 101) { + ERROR("HTTP return code not 101. Received %d with msg \"%s\".", client->hs.http_code, client->hs.http_reply_msg); + return WS_CLIENT_PROTOCOL_ERROR; + } + + client->state = WS_ESTABLISHED; + client->hs.hdr_state = WS_HDR_ALL_DONE; + INFO("Websocket Connection Accepted By Server"); + return WS_CLIENT_PARSING_DONE; + case WS_HDR_ALL_DONE: + FATAL("This is error we should never come here!"); + return WS_CLIENT_PROTOCOL_ERROR; + } + return 0; +} + +#define BYTE_MSB 0x80 +#define WS_FINAL_FRAG BYTE_MSB +#define WS_PAYLOAD_MASKED BYTE_MSB + +static inline size_t get_ws_hdr_size(size_t payload_size) +{ + size_t hdr_len = 2 + 4 /*mask*/; + if(payload_size > 125) + hdr_len += 2; + if(payload_size > 65535) + hdr_len += 6; + return hdr_len; +} + +#define MAX_POSSIBLE_HDR_LEN 14 +int ws_client_send(ws_client *client, enum websocket_opcode frame_type, const char *data, size_t size) +{ + // TODO maybe? implement fragmenting, it is not necessary though + // as both tested MQTT brokers have no reuirement of one MQTT envelope + // be equal to one WebSockets envelope. Therefore there is no need to send + // one big MQTT message as single fragmented WebSocket envelope + char hdr[MAX_POSSIBLE_HDR_LEN]; + char *ptr = hdr; + char *mask; + int size_written = 0; + size_t j = 0; + + size_t w_buff_free = rbuf_bytes_free(client->buf_write); + size_t hdr_len = get_ws_hdr_size(size); + + if (w_buff_free < hdr_len * 2) { +#ifdef DEBUG_ULTRA_VERBOSE + DEBUG("Write buffer full. Can't write requested %d size.", size); +#endif + return 0; + } + + if (w_buff_free < (hdr_len + size)) { +#ifdef DEBUG_ULTRA_VERBOSE + DEBUG("Can't write whole MQTT packet of %d bytes into the buffer. Will do partial send of %d.", size, w_buff_free - hdr_len); +#endif + size = w_buff_free - hdr_len; + hdr_len = get_ws_hdr_size(size); + // the actual needed header size might decrease if we cut number of bytes + // if decrease of size crosses 65535 or 125 boundary + // but I can live with that at least for now + // worst case is we have 6 more bytes we could have written + // no bigus dealus + } + + *ptr++ = frame_type | WS_FINAL_FRAG; + + //generate length + *ptr = WS_PAYLOAD_MASKED; + if (size > 65535) { + *ptr++ |= 0x7f; + uint64_t be = htobe64(size); + memcpy(ptr, (void *)&be, sizeof(be)); + ptr += sizeof(be); + } else if (size > 125) { + *ptr++ |= 0x7e; + uint16_t be = htobe16(size); + memcpy(ptr, (void *)&be, sizeof(be)); + ptr += sizeof(be); + } else + *ptr++ |= size; + + mask = ptr; + if (read(client->entropy_fd, mask, sizeof(uint32_t)) < (ssize_t)sizeof(uint32_t)) { + ERROR("Unable to get mask from \"" ENTROPY_SOURCE "\""); + return -2; + } + + rbuf_push(client->buf_write, hdr, hdr_len); + + if (!size) + return 0; + + // copy and mask data in the write ringbuffer + while (size - size_written) { + size_t writable_bytes; + char *w_ptr = rbuf_get_linear_insert_range(client->buf_write, &writable_bytes); + if(!writable_bytes) + break; + + writable_bytes = (writable_bytes > size) ? (size - size_written) : writable_bytes; + + memcpy(w_ptr, &data[size_written], writable_bytes); + rbuf_bump_head(client->buf_write, writable_bytes); + + for (size_t i = 0; i < writable_bytes; i++, j++) + w_ptr[i] ^= mask[j % 4]; + size_written += writable_bytes; + } + return size_written; +} + +static int check_opcode(ws_client *client,enum websocket_opcode oc) +{ + switch(oc) { + case WS_OP_BINARY_FRAME: + case WS_OP_CONNECTION_CLOSE: + case WS_OP_PING: + return 0; + case WS_OP_CONTINUATION_FRAME: + FATAL("WS_OP_CONTINUATION_FRAME NOT IMPLEMENTED YET!!!!"); + return 0; + case WS_OP_TEXT_FRAME: + FATAL("WS_OP_TEXT_FRAME NOT IMPLEMENTED YET!!!!"); + return 0; + case WS_OP_PONG: + FATAL("WS_OP_PONG NOT IMPLEMENTED YET!!!!"); + return 0; + default: + return WS_CLIENT_PROTOCOL_ERROR; + } +} + +static inline void ws_client_rx_post_hdr_state(ws_client *client) +{ + switch(client->rx.opcode) { + case WS_OP_BINARY_FRAME: + client->rx.parse_state = WS_PAYLOAD_DATA; + return; + case WS_OP_CONNECTION_CLOSE: + client->rx.parse_state = WS_PAYLOAD_CONNECTION_CLOSE; + return; + case WS_OP_PING: + client->rx.parse_state = WS_PAYLOAD_PING_REQ_PAYLOAD; + return; + default: + client->rx.parse_state = WS_PAYLOAD_SKIP_UNKNOWN_PAYLOAD; + return; + } +} + +#define LONGEST_POSSIBLE_HDR_PART 8 +int ws_client_process_rx_ws(ws_client *client) +{ + char buf[LONGEST_POSSIBLE_HDR_PART]; + size_t size; + switch (client->rx.parse_state) { + case WS_FIRST_2BYTES: + BUF_READ_CHECK_AT_LEAST(2); + rbuf_pop(client->buf_read, buf, 2); + client->rx.opcode = buf[0] & (char)~BYTE_MSB; + + if (!(buf[0] & (char)~WS_FINAL_FRAG)) { + ERROR("Not supporting fragmented messages yet!"); + return WS_CLIENT_PROTOCOL_ERROR; + } + + if (check_opcode(client, client->rx.opcode) == WS_CLIENT_PROTOCOL_ERROR) + return WS_CLIENT_PROTOCOL_ERROR; + + if (buf[1] & (char)WS_PAYLOAD_MASKED) { + ERROR("Mask is not allowed in Server->Client Websocket direction."); + return WS_CLIENT_PROTOCOL_ERROR; + } + + switch (buf[1]) { + case 127: + client->rx.parse_state = WS_PAYLOAD_EXTENDED_64; + break; + case 126: + client->rx.parse_state = WS_PAYLOAD_EXTENDED_16; + break; + default: + client->rx.payload_length = buf[1]; + ws_client_rx_post_hdr_state(client); + } + break; + case WS_PAYLOAD_EXTENDED_16: + BUF_READ_CHECK_AT_LEAST(2); + rbuf_pop(client->buf_read, buf, 2); + client->rx.payload_length = be16toh(*((uint16_t *)buf)); + ws_client_rx_post_hdr_state(client); + break; + case WS_PAYLOAD_EXTENDED_64: + BUF_READ_CHECK_AT_LEAST(LONGEST_POSSIBLE_HDR_PART); + rbuf_pop(client->buf_read, buf, LONGEST_POSSIBLE_HDR_PART); + client->rx.payload_length = be64toh(*((uint64_t *)buf)); + ws_client_rx_post_hdr_state(client); + break; + case WS_PAYLOAD_DATA: + // TODO not pretty? + while (client->rx.payload_processed < client->rx.payload_length) { + size_t remaining = client->rx.payload_length - client->rx.payload_processed; + if (!rbuf_bytes_available(client->buf_read)) + return WS_CLIENT_NEED_MORE_BYTES; + char *insert = rbuf_get_linear_insert_range(client->buf_to_mqtt, &size); + if (!insert) { +#ifdef DEBUG_ULTRA_VERBOSE + DEBUG("BUFFER TOO FULL. Avail %d req %d", (int)size, (int)remaining); +#endif + return WS_CLIENT_BUFFER_FULL; + } + size = (size > remaining) ? remaining : size; + size = rbuf_pop(client->buf_read, insert, size); + rbuf_bump_head(client->buf_to_mqtt, size); + client->rx.payload_processed += size; + } + client->rx.parse_state = WS_PACKET_DONE; + break; + case WS_PAYLOAD_CONNECTION_CLOSE: + // for WS_OP_CONNECTION_CLOSE allowed is + // a) empty payload + // b) 2byte reason code + // c) 2byte reason code followed by message + if (client->rx.payload_length == 1) { + ERROR("WebScoket CONNECTION_CLOSE can't have payload of size 1"); + return WS_CLIENT_PROTOCOL_ERROR; + } + if (!client->rx.payload_length) { + INFO("WebSocket server closed the connection without giving reason."); + client->rx.parse_state = WS_PACKET_DONE; + break; + } + client->rx.parse_state = WS_PAYLOAD_CONNECTION_CLOSE_EC; + break; + case WS_PAYLOAD_CONNECTION_CLOSE_EC: + BUF_READ_CHECK_AT_LEAST(sizeof(uint16_t)); + + rbuf_pop(client->buf_read, buf, sizeof(uint16_t)); + client->rx.specific_data.op_close.ec = be16toh(*((uint16_t *)buf)); + client->rx.payload_processed += sizeof(uint16_t); + + if(client->rx.payload_processed == client->rx.payload_length) { + INFO("WebSocket server closed the connection with EC=%d. Without message.", + client->rx.specific_data.op_close.ec); + client->rx.parse_state = WS_PACKET_DONE; + break; + } + client->rx.parse_state = WS_PAYLOAD_CONNECTION_CLOSE_MSG; + break; + case WS_PAYLOAD_CONNECTION_CLOSE_MSG: + if (!client->rx.specific_data.op_close.reason) + client->rx.specific_data.op_close.reason = mw_malloc(client->rx.payload_length + 1); + + while (client->rx.payload_processed < client->rx.payload_length) { + if (!rbuf_bytes_available(client->buf_read)) + return WS_CLIENT_NEED_MORE_BYTES; + client->rx.payload_processed += rbuf_pop(client->buf_read, + &client->rx.specific_data.op_close.reason[client->rx.payload_processed - sizeof(uint16_t)], + client->rx.payload_length - client->rx.payload_processed); + } + client->rx.specific_data.op_close.reason[client->rx.payload_length] = 0; + INFO("WebSocket server closed the connection with EC=%d and reason \"%s\"", + client->rx.specific_data.op_close.ec, + client->rx.specific_data.op_close.reason); + mw_free(client->rx.specific_data.op_close.reason); + client->rx.specific_data.op_close.reason = NULL; + client->rx.parse_state = WS_PACKET_DONE; + break; + case WS_PAYLOAD_SKIP_UNKNOWN_PAYLOAD: + BUF_READ_CHECK_AT_LEAST(client->rx.payload_length); + WARN("Skipping Websocket Packet of unsupported/unknown type"); + if (client->rx.payload_length) + rbuf_bump_tail(client->buf_read, client->rx.payload_length); + client->rx.parse_state = WS_PACKET_DONE; + return WS_CLIENT_PARSING_DONE; + case WS_PAYLOAD_PING_REQ_PAYLOAD: + if (client->rx.payload_length > rbuf_get_capacity(client->buf_read) / 2) { + ERROR("Ping arrived with payload which is too big!"); + return WS_CLIENT_INTERNAL_ERROR; + } + BUF_READ_CHECK_AT_LEAST(client->rx.payload_length); + client->rx.specific_data.ping_msg = mw_malloc(client->rx.payload_length); + rbuf_pop(client->buf_read, client->rx.specific_data.ping_msg, client->rx.payload_length); + // TODO schedule this instead of sending right away + // then attempt to send as soon as buffer space clears up + size = ws_client_send(client, WS_OP_PONG, client->rx.specific_data.ping_msg, client->rx.payload_length); + if (size != client->rx.payload_length) { + ERROR("Unable to send the PONG as one packet back. Closing connection."); + return WS_CLIENT_PROTOCOL_ERROR; + } + client->rx.parse_state = WS_PACKET_DONE; + return WS_CLIENT_PARSING_DONE; + case WS_PACKET_DONE: + client->rx.parse_state = WS_FIRST_2BYTES; + client->rx.payload_processed = 0; + if (client->rx.opcode == WS_OP_CONNECTION_CLOSE) + return WS_CLIENT_CONNECTION_CLOSED; + return WS_CLIENT_PARSING_DONE; + default: + FATAL("Unknown parse state"); + return WS_CLIENT_INTERNAL_ERROR; + } + return 0; +} + +int ws_client_process(ws_client *client) +{ + int ret; + switch(client->state) { + case WS_RAW: + if (ws_client_start_handshake(client)) + return WS_CLIENT_INTERNAL_ERROR; + return WS_CLIENT_NEED_MORE_BYTES; + case WS_HANDSHAKE: + do { + ret = ws_client_parse_handshake_resp(client); + if (ret == WS_CLIENT_PROTOCOL_ERROR) + client->state = WS_ERROR; + if (ret == WS_CLIENT_PARSING_DONE && client->state == WS_ESTABLISHED) + ret = WS_CLIENT_NEED_MORE_BYTES; + } while (!ret); + break; + case WS_ESTABLISHED: + do { + ret = ws_client_process_rx_ws(client); + switch(ret) { + case WS_CLIENT_PROTOCOL_ERROR: + client->state = WS_ERROR; + break; + case WS_CLIENT_CONNECTION_CLOSED: + client->state = WS_CONN_CLOSED_GRACEFUL; + break; + } + // if ret == 0 we can continue parsing + // if ret == WS_CLIENT_PARSING_DONE we processed + // one websocket packet and attempt processing + // next one if data available in the buffer + } while (!ret || ret == WS_CLIENT_PARSING_DONE); + break; + case WS_ERROR: + ERROR("ws_client is in error state. Restart the connection!"); + return WS_CLIENT_PROTOCOL_ERROR; + case WS_CONN_CLOSED_GRACEFUL: + ERROR("Connection has been gracefully closed. Calling this is useless (and probably bug) until you reconnect again."); + return WS_CLIENT_CONNECTION_CLOSED; + default: + FATAL("Unknown connection state! Probably memory corruption."); + return WS_CLIENT_INTERNAL_ERROR; + } + return ret; +} |