/*
* SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <sys/random.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include "esp_log.h"
#include "esp_transport.h"
#include "esp_transport_tcp.h"
#include "esp_transport_ws.h"
#include "esp_transport_internal.h"
#include "errno.h"
#include "esp_tls_crypto.h"
#include <arpa/inet.h>
static const char *TAG = "transport_ws";
#define WS_BUFFER_SIZE CONFIG_WS_BUFFER_SIZE
#define WS_FIN 0x80
#define WS_OPCODE_CONT 0x00
#define WS_OPCODE_TEXT 0x01
#define WS_OPCODE_BINARY 0x02
#define WS_OPCODE_CLOSE 0x08
#define WS_OPCODE_PING 0x09
#define WS_OPCODE_PONG 0x0a
#define WS_OPCODE_CONTROL_FRAME 0x08
// Second byte
#define WS_MASK 0x80
#define WS_SIZE16 126
#define WS_SIZE64 127
#define MAX_WEBSOCKET_HEADER_SIZE 16
#define WS_RESPONSE_OK 101
#define WS_TRANSPORT_MAX_CONTROL_FRAME_BUFFER_LEN 125
typedef struct {
uint8_t opcode;
bool fin; /*!< Frame fin flag, for continuations */
char mask_key[4]; /*!< Mask key for this payload */
int payload_len; /*!< Total length of the payload */
int bytes_remaining; /*!< Bytes left to read of the payload */
bool header_received; /*!< Flag to indicate that a new message header was received */
} ws_transport_frame_state_t;
typedef struct {
char *path;
char *buffer;
char *sub_protocol;
char *user_agent;
char *headers;
char *auth;
int http_status_code;
bool propagate_control_frames;
ws_transport_frame_state_t frame_state;
esp_transport_handle_t parent;
} transport_ws_t;
/**
* @brief Handles control frames
*
* This API is used internally to handle control frames at the transport layer.
* The API could be possibly promoted to a public API if needed by some clients
*
* @param t Websocket transport handle
* @param buffer Buffer with the actual payload of the control packet to be processed
* @param len Length of the buffer (typically the same as the payload buffer)
* @param timeout_ms The timeout milliseconds
* @param client_closed To indicate that the connection has been closed by the client
* (to prevent echoing the CLOSE packet if true, as this is the actual echo from the server)
*
* @return
* 0 - no activity, or successfully responded to PING
* -1 - Failure: Error on read or the actual payload longer then buffer
* 1 - Close handshake success
* 2 - Got PONG message
*/
static int esp_transport_ws_handle_control_frames(esp_transport_handle_t t, char *buffer, int len, int timeout_ms, bool client_closed);
static inline uint8_t ws_get_bin_opcode(ws_transport_opcodes_t opcode)
{
return (uint8_t)opcode;
}
static esp_transport_handle_t ws_get_payload_transport_handle(esp_transport_handle_t t)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
/* Reading parts of a frame directly will disrupt the WS internal frame state,
reset bytes_remaining to prepare for reading a new frame */
ws->frame_state.bytes_remaining = 0;
return ws->parent;
}
static char *trimwhitespace(const char *str)
{
char *end;
// Trim leading space
while (isspace((unsigned char)*str)) {
str++;
}
if (*str == 0) {
return (char *)str;
}
// Trim trailing space
end = (char *)(str + strlen(str) - 1);
while (end > str && isspace((unsigned char)*end)) {
end--;
}
// Write new null terminator
*(end + 1) = 0;
return (char *)str;
}
static int get_http_status_code(const char *buffer)
{
const char http[] = "HTTP/";
const char *found = strcasestr(buffer, http);
char status_code[4];
if (found) {
found += sizeof(http)/sizeof(http[0]) - 1;
found = strchr(found, ' ');
if (found) {
found++;
strncpy(status_code, found, 4);
status_code[3] = '\0';
int code = atoi(status_code);
ESP_LOGD(TAG, "HTTP status code is %d", code);
return code == 0 ? -1 : code;
}
}
return -1;
}
static char *get_http_header(const char *buffer, const char *key)
{
char *found = strcasestr(buffer, key);
if (found) {
found += strlen(key);
char *found_end = strstr(found, "\r\n");
if (found_end) {
found_end[0] = 0;//terminal string
return trimwhitespace(found);
}
}
return NULL;
}
static int ws_connect(esp_transport_handle_t t, const char *host, int port, int timeout_ms)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
if (esp_transport_connect(ws->parent, host, port, timeout_ms) < 0) {
ESP_LOGE(TAG, "Error connecting to host %s:%d", host, port);
return -1;
}
unsigned char random_key[16];
ssize_t rc;
if ((rc = getrandom(random_key, sizeof(random_key), 0)) < 0) {
ESP_LOGD(TAG, "getrandom() returned %zd", rc);
return -1;
}
// Size of base64 coded string is equal '((input_size * 4) / 3) + (input_size / 96) + 6' including Z-term
unsigned char client_key[28] = {0};
const char *user_agent_ptr = (ws->user_agent) ? (ws->user_agent) : "ESP32 Websocket Client";
#ifdef CONFIG_WS_DYNAMIC_BUFFER
if (!ws->buffer) {
ws->buffer = malloc(WS_BUFFER_SIZE);
if (!ws->buffer) {
ESP_LOGE(TAG, "Cannot allocate buffer for connect, need-%d", WS_BUFFER_SIZE);
return -1;
}
}
#endif
size_t outlen = 0;
esp_crypto_base64_encode(client_key, sizeof(client_key), &outlen, random_key, sizeof(random_key));
int len = snprintf(ws->buffer, WS_BUFFER_SIZE,
"GET %s HTTP/1.1\r\n"
"Connection: Upgrade\r\n"
"Host: %s:%d\r\n"
"User-Agent: %s\r\n"
"Upgrade: websocket\r\n"
"Sec-WebSocket-Version: 13\r\n"
"Sec-WebSocket-Key: %s\r\n",
ws->path,
host, port, user_agent_ptr,
client_key);
if (len <= 0 || len >= WS_BUFFER_SIZE) {
ESP_LOGE(TAG, "Error in request generation, desired request len: %d, buffer size: %d", len, WS_BUFFER_SIZE);
return -1;
}
if (ws->sub_protocol) {
ESP_LOGD(TAG, "sub_protocol: %s", ws->sub_protocol);
int r = snprintf(ws->buffer + len, WS_BUFFER_SIZE - len, "Sec-WebSocket-Protocol: %s\r\n", ws->sub_protocol);
len += r;
if (r <= 0 || len >= WS_BUFFER_SIZE) {
ESP_LOGE(TAG, "Error in request generation"
"(snprintf of subprotocol returned %d, desired request len: %d, buffer size: %d", r, len, WS_BUFFER_SIZE);
return -1;
}
}
if (ws->auth) {
ESP_LOGD(TAG, "Authorization: %s", ws->auth);
int r = snprintf(ws->buffer + len, WS_BUFFER_SIZE - len, "Authorization: %s\r\n", ws->auth);
len += r;
if (r <= 0 || len >= WS_BUFFER_SIZE) {
ESP_LOGE(TAG, "Error in request generation"
"(snprintf of authorization returned %d, desired request len: %d, buffer size: %d", r, len, WS_BUFFER_SIZE);
return -1;
}
}
if (ws->headers) {
ESP_LOGD(TAG, "headers: %s", ws->headers);
int r = snprintf(ws->buffer + len, WS_BUFFER_SIZE - len, "%s", ws->headers);
len += r;
if (r <= 0 || len >= WS_BUFFER_SIZE) {
ESP_LOGE(TAG, "Error in request generation"
"(strncpy of headers returned %d, desired request len: %d, buffer size: %d", r, len, WS_BUFFER_SIZE);
return -1;
}
}
int r = snprintf(ws->buffer + len, WS_BUFFER_SIZE - len, "\r\n");
len += r;
if (r <= 0 || len >= WS_BUFFER_SIZE) {
ESP_LOGE(TAG, "Error in request generation"
"(snprintf of header terminal returned %d, desired request len: %d, buffer size: %d", r, len, WS_BUFFER_SIZE);
return -1;
}
ESP_LOGD(TAG, "Write upgrade request\r\n%s", ws->buffer);
if (esp_transport_write(ws->parent, ws->buffer, len, timeout_ms) <= 0) {
ESP_LOGE(TAG, "Error write Upgrade header %s", ws->buffer);
return -1;
}
int header_len = 0;
do {
if ((len = esp_transport_read(ws->parent, ws->buffer + header_len, WS_BUFFER_SIZE - header_len, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error read response for Upgrade header %s", ws->buffer);
return -1;
}
header_len += len;
ws->buffer[header_len] = '\0';
ESP_LOGD(TAG, "Read header chunk %d, current header size: %d", len, header_len);
} while (NULL == strstr(ws->buffer, "\r\n\r\n") && header_len < WS_BUFFER_SIZE);
ws->http_status_code = get_http_status_code(ws->buffer);
if (ws->http_status_code == -1) {
ESP_LOGE(TAG, "HTTP upgrade failed");
return -1;
}
char *server_key = get_http_header(ws->buffer, "Sec-WebSocket-Accept:");
if (server_key == NULL) {
ESP_LOGE(TAG, "Sec-WebSocket-Accept not found");
return -1;
}
// See esp_crypto_sha1() arg size
unsigned char expected_server_sha1[20];
// Size of base64 coded string see above
unsigned char expected_server_key[33] = {0};
// If you are interested, see https://tools.ietf.org/html/rfc6455
const char expected_server_magic[] = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
unsigned char expected_server_text[sizeof(client_key) + sizeof(expected_server_magic) + 1];
strcpy((char *)expected_server_text, (char *)client_key);
strcat((char *)expected_server_text, expected_server_magic);
size_t key_len = strlen((char *)expected_server_text);
esp_crypto_sha1(expected_server_text, key_len, expected_server_sha1);
esp_crypto_base64_encode(expected_server_key, sizeof(expected_server_key), &outlen, expected_server_sha1, sizeof(expected_server_sha1));
expected_server_key[ (outlen < sizeof(expected_server_key)) ? outlen : (sizeof(expected_server_key) - 1) ] = 0;
ESP_LOGD(TAG, "server key=%s, send_key=%s, expected_server_key=%s", (char *)server_key, (char *)client_key, expected_server_key);
if (strcmp((char *)expected_server_key, (char *)server_key) != 0) {
ESP_LOGE(TAG, "Invalid websocket key");
return -1;
}
#ifdef CONFIG_WS_DYNAMIC_BUFFER
free(ws->buffer);
ws->buffer = NULL;
#endif
return 0;
}
static int _ws_write(esp_transport_handle_t t, int opcode, int mask_flag, const char *b, int len, int timeout_ms)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
char *buffer = (char *)b;
char ws_header[MAX_WEBSOCKET_HEADER_SIZE];
char *mask;
int header_len = 0, i;
int poll_write;
if ((poll_write = esp_transport_poll_write(ws->parent, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error transport_poll_write");
return poll_write;
}
ws_header[header_len++] = opcode;
if (len <= 125) {
ws_header[header_len++] = (uint8_t)(len | mask_flag);
} else if (len < 65536) {
ws_header[header_len++] = WS_SIZE16 | mask_flag;
ws_header[header_len++] = (uint8_t)(len >> 8);
ws_header[header_len++] = (uint8_t)(len & 0xFF);
} else {
ws_header[header_len++] = WS_SIZE64 | mask_flag;
/* Support maximum 4 bytes length */
ws_header[header_len++] = 0; //(uint8_t)((len >> 56) & 0xFF);
ws_header[header_len++] = 0; //(uint8_t)((len >> 48) & 0xFF);
ws_header[header_len++] = 0; //(uint8_t)((len >> 40) & 0xFF);
ws_header[header_len++] = 0; //(uint8_t)((len >> 32) & 0xFF);
ws_header[header_len++] = (uint8_t)((len >> 24) & 0xFF);
ws_header[header_len++] = (uint8_t)((len >> 16) & 0xFF);
ws_header[header_len++] = (uint8_t)((len >> 8) & 0xFF);
ws_header[header_len++] = (uint8_t)((len >> 0) & 0xFF);
}
if (mask_flag) {
mask = &ws_header[header_len];
ssize_t rc;
if ((rc = getrandom(ws_header + header_len, 4, 0)) < 0) {
ESP_LOGD(TAG, "getrandom() returned %zd", rc);
return -1;
}
header_len += 4;
for (i = 0; i < len; ++i) {
buffer[i] = (buffer[i] ^ mask[i % 4]);
}
}
if (esp_transport_write(ws->parent, ws_header, header_len, timeout_ms) != header_len) {
ESP_LOGE(TAG, "Error write header");
return -1;
}
if (len == 0) {
return 0;
}
int ret = esp_transport_write(ws->parent, buffer, len, timeout_ms);
// in case of masked transport we have to revert back to the original data, as ws layer
// does not create its own copy of data to be sent
if (mask_flag) {
mask = &ws_header[header_len - 4];
for (i = 0; i < len; ++i) {
buffer[i] = (buffer[i] ^ mask[i % 4]);
}
}
return ret;
}
int esp_transport_ws_send_raw(esp_transport_handle_t t, ws_transport_opcodes_t opcode, const char *b, int len, int timeout_ms)
{
uint8_t op_code = ws_get_bin_opcode(opcode);
if (t == NULL) {
ESP_LOGE(TAG, "Transport must be a valid ws handle");
return ESP_ERR_INVALID_ARG;
}
ESP_LOGD(TAG, "Sending raw ws message with opcode %d", op_code);
return _ws_write(t, op_code, WS_MASK, b, len, timeout_ms);
}
static int ws_write(esp_transport_handle_t t, const char *b, int len, int timeout_ms)
{
if (len == 0) {
// Default transport write of zero length in ws layer sends out a ping message.
// This behaviour could however be altered in IDF 5.0, since a separate API for sending
// messages with user defined opcodes has been introduced.
ESP_LOGD(TAG, "Write PING message");
return _ws_write(t, WS_OPCODE_PING | WS_FIN, WS_MASK, NULL, 0, timeout_ms);
}
return _ws_write(t, WS_OPCODE_BINARY | WS_FIN, WS_MASK, b, len, timeout_ms);
}
static int ws_read_payload(esp_transport_handle_t t, char *buffer, int len, int timeout_ms)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
int bytes_to_read;
int rlen = 0;
if (ws->frame_state.bytes_remaining > len) {
ESP_LOGD(TAG, "Actual data to receive (%d) are longer than ws buffer (%d)", ws->frame_state.bytes_remaining, len);
bytes_to_read = len;
} else {
bytes_to_read = ws->frame_state.bytes_remaining;
}
// Receive and process payload
if (bytes_to_read != 0 && (rlen = esp_transport_read(ws->parent, buffer, bytes_to_read, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error read data");
return rlen;
}
ws->frame_state.bytes_remaining -= rlen;
for (int i = 0; i < bytes_to_read; i++) {
buffer[i] = (buffer[i] ^ ws->frame_state.mask_key[i % 4]);
}
return rlen;
}
/* Read and parse the WS header, determine length of payload */
static int ws_read_header(esp_transport_handle_t t, char *buffer, int len, int timeout_ms)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
int payload_len;
char ws_header[MAX_WEBSOCKET_HEADER_SIZE];
char *data_ptr = ws_header, mask;
int rlen;
int poll_read;
ws->frame_state.header_received = false;
if ((poll_read = esp_transport_poll_read(ws->parent, timeout_ms)) <= 0) {
return poll_read;
}
// Receive and process header first (based on header size)
int header = 2;
int mask_len = 4;
if ((rlen = esp_transport_read(ws->parent, data_ptr, header, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error read data");
return rlen;
}
ws->frame_state.header_received = true;
ws->frame_state.fin = (*data_ptr & 0x80) != 0;
ws->frame_state.opcode = (*data_ptr & 0x0F);
data_ptr ++;
mask = ((*data_ptr >> 7) & 0x01);
payload_len = (*data_ptr & 0x7F);
data_ptr++;
ESP_LOGD(TAG, "Opcode: %d, mask: %d, len: %d", ws->frame_state.opcode, mask, payload_len);
if (payload_len == 126) {
// headerLen += 2;
if ((rlen = esp_transport_read(ws->parent, data_ptr, header, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error read data");
return rlen;
}
payload_len = data_ptr[0] << 8 | data_ptr[1];
} else if (payload_len == 127) {
// headerLen += 8;
header = 8;
if ((rlen = esp_transport_read(ws->parent, data_ptr, header, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error read data");
return rlen;
}
if (data_ptr[0] != 0 || data_ptr[1] != 0 || data_ptr[2] != 0 || data_ptr[3] != 0) {
// really too big!
payload_len = 0xFFFFFFFF;
} else {
payload_len = data_ptr[4] << 24 | data_ptr[5] << 16 | data_ptr[6] << 8 | data_ptr[7];
}
}
if (mask) {
// Read and store mask
if (payload_len != 0 && (rlen = esp_transport_read(ws->parent, buffer, mask_len, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error read data");
return rlen;
}
memcpy(ws->frame_state.mask_key, buffer, mask_len);
} else {
memset(ws->frame_state.mask_key, 0, mask_len);
}
ws->frame_state.payload_len = payload_len;
ws->frame_state.bytes_remaining = payload_len;
return payload_len;
}
static int ws_handle_control_frame_internal(esp_transport_handle_t t, int timeout_ms)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
char *control_frame_buffer = NULL;
int control_frame_buffer_len = 0;
int payload_len = ws->frame_state.payload_len;
int ret = 0;
// If no new header reception in progress, or not a control frame
// just pass 0 -> no need to handle control frames
if (ws->frame_state.header_received == false ||
!(ws->frame_state.opcode & WS_OPCODE_CONTROL_FRAME)) {
return 0;
}
if (payload_len > WS_TRANSPORT_MAX_CONTROL_FRAME_BUFFER_LEN) {
ESP_LOGE(TAG, "Not enough room for reading control frames (need=%d, max_allowed=%d)",
ws->frame_state.payload_len, WS_TRANSPORT_MAX_CONTROL_FRAME_BUFFER_LEN);
return -1;
}
// Now we can handle the control frame correctly (either zero payload, or a short one for which we allocate mem)
control_frame_buffer_len = payload_len;
if (control_frame_buffer_len > 0) {
control_frame_buffer = malloc(control_frame_buffer_len);
if (control_frame_buffer == NULL) {
ESP_LOGE(TAG, "Cannot allocate buffer for control frames, need-%d", control_frame_buffer_len);
return -1;
}
} else {
control_frame_buffer_len = 0;
}
// read the payload of the control frame
int actual_len = ws_read_payload(t, control_frame_buffer, control_frame_buffer_len, timeout_ms);
if (actual_len != payload_len) {
ESP_LOGE(TAG, "Control frame (opcode=%d) payload read failed (payload_len=%d, read_len=%d)",
ws->frame_state.opcode, payload_len, actual_len);
ret = -1;
goto free_payload_buffer;
}
ret = esp_transport_ws_handle_control_frames(t, control_frame_buffer, control_frame_buffer_len, timeout_ms, false);
free_payload_buffer:
free(control_frame_buffer);
return ret > 0 ? 0 : ret; // We don't propagate control frames, pass 0 to upper layers
}
static int ws_read(esp_transport_handle_t t, char *buffer, int len, int timeout_ms)
{
int rlen = 0;
transport_ws_t *ws = esp_transport_get_context_data(t);
// If message exceeds buffer len then subsequent reads will skip reading header and read whatever is left of the payload
if (ws->frame_state.bytes_remaining <= 0) {
if ( (rlen = ws_read_header(t, buffer, len, timeout_ms)) < 0) {
// If something when wrong then we prepare for reading a new header
ws->frame_state.bytes_remaining = 0;
return rlen;
}
// If the new opcode is a control frame and we don't pass it to the app
// - try to handle it internally using the application buffer
if (ws->frame_state.header_received && (ws->frame_state.opcode & WS_OPCODE_CONTROL_FRAME) &&
ws->propagate_control_frames == false) {
// automatically handle only 0 payload frames and make the transport read to return 0 on success
// which might be interpreted as timeouts
return ws_handle_control_frame_internal(t, timeout_ms);
}
if (rlen == 0) {
ws->frame_state.bytes_remaining = 0;
return 0; // timeout
}
}
if (ws->frame_state.payload_len) {
if ( (rlen = ws_read_payload(t, buffer, len, timeout_ms)) <= 0) {
ESP_LOGE(TAG, "Error reading payload data");
ws->frame_state.bytes_remaining = 0;
return rlen;
}
}
return rlen;
}
static int ws_poll_read(esp_transport_handle_t t, int timeout_ms)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
return esp_transport_poll_read(ws->parent, timeout_ms);
}
static int ws_poll_write(esp_transport_handle_t t, int timeout_ms)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
return esp_transport_poll_write(ws->parent, timeout_ms);;
}
static int ws_close(esp_transport_handle_t t)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
return esp_transport_close(ws->parent);
}
static esp_err_t ws_destroy(esp_transport_handle_t t)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
free(ws->buffer);
free(ws->path);
free(ws->sub_protocol);
free(ws->user_agent);
free(ws->headers);
free(ws->auth);
free(ws);
return 0;
}
static esp_err_t internal_esp_transport_ws_set_path(esp_transport_handle_t t, const char *path)
{
if (t == NULL) {
return ESP_ERR_INVALID_ARG;
}
transport_ws_t *ws = esp_transport_get_context_data(t);
if (ws->path) {
free(ws->path);
}
if (path == NULL) {
ws->path = NULL;
return ESP_OK;
}
ws->path = strdup(path);
if (ws->path == NULL) {
return ESP_ERR_NO_MEM;
}
return ESP_OK;
}
void esp_transport_ws_set_path(esp_transport_handle_t t, const char *path)
{
esp_err_t err = internal_esp_transport_ws_set_path(t, path);
if (err != ESP_OK) {
ESP_LOGE(TAG, "esp_transport_ws_set_path has internally failed with err=%d", err);
}
}
static int ws_get_socket(esp_transport_handle_t t)
{
if (t) {
transport_ws_t *ws = t->data;
if (ws && ws->parent && ws->parent->_get_socket) {
return ws->parent->_get_socket(ws->parent);
}
}
return -1;
}
esp_transport_handle_t esp_transport_ws_init(esp_transport_handle_t parent_handle)
{
if (parent_handle == NULL || parent_handle->foundation == NULL) {
ESP_LOGE(TAG, "Invalid parent ptotocol");
return NULL;
}
esp_transport_handle_t t = esp_transport_init();
if (t == NULL) {
return NULL;
}
transport_ws_t *ws = calloc(1, sizeof(transport_ws_t));
ESP_TRANSPORT_MEM_CHECK(TAG, ws, {
esp_transport_destroy(t);
return NULL;
});
ws->parent = parent_handle;
t->foundation = parent_handle->foundation;
ws->path = strdup("/");
ESP_TRANSPORT_MEM_CHECK(TAG, ws->path, {
free(ws);
esp_transport_destroy(t);
return NULL;
});
ws->buffer = malloc(WS_BUFFER_SIZE);
ESP_TRANSPORT_MEM_CHECK(TAG, ws->buffer, {
free(ws->path);
free(ws);
esp_transport_destroy(t);
return NULL;
});
esp_transport_set_func(t, ws_connect, ws_read, ws_write, ws_close, ws_poll_read, ws_poll_write, ws_destroy);
// websocket underlying transfer is the payload transfer handle
esp_transport_set_parent_transport_func(t, ws_get_payload_transport_handle);
esp_transport_set_context_data(t, ws);
t->_get_socket = ws_get_socket;
return t;
}
esp_err_t esp_transport_ws_set_subprotocol(esp_transport_handle_t t, const char *sub_protocol)
{
if (t == NULL) {
return ESP_ERR_INVALID_ARG;
}
transport_ws_t *ws = esp_transport_get_context_data(t);
if (ws->sub_protocol) {
free(ws->sub_protocol);
}
if (sub_protocol == NULL) {
ws->sub_protocol = NULL;
return ESP_OK;
}
ws->sub_protocol = strdup(sub_protocol);
if (ws->sub_protocol == NULL) {
return ESP_ERR_NO_MEM;
}
return ESP_OK;
}
esp_err_t esp_transport_ws_set_user_agent(esp_transport_handle_t t, const char *user_agent)
{
if (t == NULL) {
return ESP_ERR_INVALID_ARG;
}
transport_ws_t *ws = esp_transport_get_context_data(t);
if (ws->user_agent) {
free(ws->user_agent);
}
if (user_agent == NULL) {
ws->user_agent = NULL;
return ESP_OK;
}
ws->user_agent = strdup(user_agent);
if (ws->user_agent == NULL) {
return ESP_ERR_NO_MEM;
}
return ESP_OK;
}
esp_err_t esp_transport_ws_set_headers(esp_transport_handle_t t, const char *headers)
{
if (t == NULL) {
return ESP_ERR_INVALID_ARG;
}
transport_ws_t *ws = esp_transport_get_context_data(t);
if (ws->headers) {
free(ws->headers);
}
if (headers == NULL) {
ws->headers = NULL;
return ESP_OK;
}
ws->headers = strdup(headers);
if (ws->headers == NULL) {
return ESP_ERR_NO_MEM;
}
return ESP_OK;
}
esp_err_t esp_transport_ws_set_auth(esp_transport_handle_t t, const char *auth)
{
if (t == NULL) {
return ESP_ERR_INVALID_ARG;
}
transport_ws_t *ws = esp_transport_get_context_data(t);
if (ws->auth) {
free(ws->auth);
}
if (auth == NULL) {
ws->auth = NULL;
return ESP_OK;
}
ws->auth = strdup(auth);
if (ws->auth == NULL) {
return ESP_ERR_NO_MEM;
}
return ESP_OK;
}
esp_err_t esp_transport_ws_set_config(esp_transport_handle_t t, const esp_transport_ws_config_t *config)
{
if (t == NULL) {
return ESP_ERR_INVALID_ARG;
}
esp_err_t err = ESP_OK;
transport_ws_t *ws = esp_transport_get_context_data(t);
if (config->ws_path) {
err = internal_esp_transport_ws_set_path(t, config->ws_path);
ESP_TRANSPORT_ERR_OK_CHECK(TAG, err, return err;)
}
if (config->sub_protocol) {
err = esp_transport_ws_set_subprotocol(t, config->sub_protocol);
ESP_TRANSPORT_ERR_OK_CHECK(TAG, err, return err;)
}
if (config->user_agent) {
err = esp_transport_ws_set_user_agent(t, config->user_agent);
ESP_TRANSPORT_ERR_OK_CHECK(TAG, err, return err;)
}
if (config->headers) {
err = esp_transport_ws_set_headers(t, config->headers);
ESP_TRANSPORT_ERR_OK_CHECK(TAG, err, return err;)
}
if (config->auth) {
err = esp_transport_ws_set_auth(t, config->auth);
ESP_TRANSPORT_ERR_OK_CHECK(TAG, err, return err;)
}
ws->propagate_control_frames = config->propagate_control_frames;
return err;
}
bool esp_transport_ws_get_fin_flag(esp_transport_handle_t t)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
return ws->frame_state.fin;
}
int esp_transport_ws_get_upgrade_request_status(esp_transport_handle_t t)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
return ws->http_status_code;
}
ws_transport_opcodes_t esp_transport_ws_get_read_opcode(esp_transport_handle_t t)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
if (ws->frame_state.header_received) {
// convert the header byte to enum if correctly received
return (ws_transport_opcodes_t)ws->frame_state.opcode;
}
return WS_TRANSPORT_OPCODES_NONE;
}
int esp_transport_ws_get_read_payload_len(esp_transport_handle_t t)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
return ws->frame_state.payload_len;
}
static int esp_transport_ws_handle_control_frames(esp_transport_handle_t t, char *buffer, int len, int timeout_ms, bool client_closed)
{
transport_ws_t *ws = esp_transport_get_context_data(t);
// If no new header reception in progress, or not a control frame
// just pass 0 -> no need to handle control frames
if (ws->frame_state.header_received == false ||
!(ws->frame_state.opcode & WS_OPCODE_CONTROL_FRAME)) {
return 0;
}
int actual_len;
int payload_len = ws->frame_state.payload_len;
ESP_LOGD(TAG, "Handling control frame with %d bytes payload", payload_len);
if (payload_len > len) {
ESP_LOGE(TAG, "Not enough room for processing the payload (need=%d, available=%d)", payload_len, len);
ws->frame_state.bytes_remaining = payload_len - len;
return -1;
}
if (ws->frame_state.opcode == WS_OPCODE_PING) {
// handle PING frames internally: just send a PONG with the same payload
actual_len = _ws_write(t, WS_OPCODE_PONG | WS_FIN, WS_MASK, buffer,
payload_len, timeout_ms);
if (actual_len != payload_len) {
ESP_LOGE(TAG, "PONG send failed (payload_len=%d, written_len=%d)", payload_len, actual_len);
return -1;
}
ESP_LOGD(TAG, "PONG sent correctly (payload_len=%d)", payload_len);
// control frame handled correctly, reset the flag indicating new header received
ws->frame_state.header_received = false;
return 0;
} else if (ws->frame_state.opcode == WS_OPCODE_CLOSE) {
// handle CLOSE by the server: send a zero payload frame
if (buffer && payload_len > 0) { // if some payload, print out the status code
uint16_t *code_network_order = (uint16_t *) buffer;
ESP_LOGI(TAG, "Got CLOSE frame with status code=%u", ntohs(*code_network_order));
}
if (client_closed == false) {
// Only echo the closing frame if not initiated by the client
if (_ws_write(t, WS_OPCODE_CLOSE | WS_FIN, WS_MASK, NULL, 0, timeout_ms) < 0) {
ESP_LOGE(TAG, "Sending CLOSE frame with 0 payload failed");
return -1;
}
ESP_LOGD(TAG, "CLOSE frame with no payload sent correctly");
}
// control frame handled correctly, reset the flag indicating new header received
ws->frame_state.header_received = false;
int ret = esp_transport_ws_poll_connection_closed(t, timeout_ms);
if (ret == 0) {
ESP_LOGW(TAG, "Connection cannot be terminated gracefully within timeout=%d", timeout_ms);
return -1;
}
if (ret < 0) {
ESP_LOGW(TAG, "Connection terminated while waiting for clean TCP close");
return -1;
}
ESP_LOGI(TAG, "Connection terminated gracefully");
return 1;
} else if (ws->frame_state.opcode == WS_OPCODE_PONG) {
// handle PONG: just indicate return code
ESP_LOGD(TAG, "Received PONG frame with payload=%d", payload_len);
// control frame handled correctly, reset the flag indicating new header received
ws->frame_state.header_received = false;
return 2;
}
return 0;
}
int esp_transport_ws_poll_connection_closed(esp_transport_handle_t t, int timeout_ms)
{
struct timeval timeout;
int sock = esp_transport_get_socket(t);
fd_set readset;
fd_set errset;
FD_ZERO(&readset);
FD_ZERO(&errset);
FD_SET(sock, &readset);
FD_SET(sock, &errset);
int ret = select(sock + 1, &readset, NULL, &errset, esp_transport_utils_ms_to_timeval(timeout_ms, &timeout));
if (ret > 0) {
if (FD_ISSET(sock, &readset)) {
uint8_t buffer;
if (recv(sock, &buffer, 1, MSG_PEEK) <= 0) {
// socket is readable, but reads zero bytes -- connection cleanly closed by FIN flag
return 1;
}
ESP_LOGW(TAG, "esp_transport_ws_poll_connection_closed: unexpected data readable on socket=%d", sock);
} else if (FD_ISSET(sock, &errset)) {
int sock_errno = 0;
uint32_t optlen = sizeof(sock_errno);
getsockopt(sock, SOL_SOCKET, SO_ERROR, &sock_errno, &optlen);
ESP_LOGD(TAG, "esp_transport_ws_poll_connection_closed select error %d, errno = %s, fd = %d", sock_errno, strerror(sock_errno), sock);
if (sock_errno == ENOTCONN || sock_errno == ECONNRESET || sock_errno == ECONNABORTED) {
// the three err codes above might be caused by connection termination by RTS flag
// which we still assume as expected closing sequence of ws-transport connection
return 1;
}
ESP_LOGE(TAG, "esp_transport_ws_poll_connection_closed: unexpected errno=%d on socket=%d", sock_errno, sock);
}
return -1; // indicates error: socket unexpectedly reads an actual data, or unexpected errno code
}
return ret;
}