/*
* Performs HTTP handshake. *fd* is the file descriptor of the
* connection to the client. This function returns 0 if it succeeds,
* or returns -1.
*/
int http_handshake(int fd) {
char header[16384], *accept_key, *keyhdstart, *keyhdend, res_header[256];
size_t header_length = 0, res_header_sent = 0, res_header_length;
ssize_t r;
while(1) {
while((r = read(fd, header+header_length,
sizeof(header)-header_length)) == -1 && errno == EINTR);
if(r == -1) {
perror("read");
return -1;
} else if(r == 0) {
fprintf(stderr, "HTTP Handshake: Got EOF\n");
return -1;
} else {
header_length += r;
if(header_length >= 4 &&
memcmp(header+header_length-4, "\r\n\r\n", 4) == 0) {
break;
} else if(header_length == sizeof(header)) {
fprintf(stderr, "HTTP Handshake: Too large HTTP headers\n");
return -1;
}
}
}
if(http_header_find_field_value(header, "Upgrade", "websocket") == NULL ||
http_header_find_field_value(header, "Connection", "Upgrade") == NULL ||
(keyhdstart = http_header_find_field_value(header, "Sec-WebSocket-Key", NULL)) == NULL) {
fprintf(stderr, "HTTP Handshake: Missing required header fields\n");
return -1;
}
for(; *keyhdstart == ' '; ++keyhdstart);
keyhdend = keyhdstart;
for(; *keyhdend != '\r' && *keyhdend != ' '; ++keyhdend);
if(keyhdend-keyhdstart != 24) {
printf("%s\n", keyhdstart);
fprintf(stderr, "HTTP Handshake: Invalid value in Sec-WebSocket-Key\n");
return -1;
}
accept_key = create_accept_key(keyhdstart);
snprintf(res_header, sizeof(res_header),
"HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: websocket\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"\r\n", accept_key);
free(accept_key);
res_header_length = strlen(res_header);
while(res_header_sent < res_header_length) {
while((r = write(fd, res_header+res_header_sent, res_header_length-res_header_sent)) == -1 && errno == EINTR);
if(r == -1) {
perror("write");
return -1;
} else {
res_header_sent += r;
}
}
return 0;
}
/*
* Performs HTTP handshake. *fd* is the file descriptor of the
* connection to the client. This function returns 0 if it succeeds,
* or returns -1.
*/
int http_handshake(int fd)
{
/*
* Note: The implementation of HTTP handshake in this function is
* written for just a example of how to use of wslay library and is
* not meant to be used in production code. In practice, you need
* to do more strict verification of the client's handshake.
*/
char header[16384], accept_key[29], *keyhdstart, *keyhdend, res_header[256];
size_t header_length = 0, res_header_sent = 0, res_header_length;
ssize_t r;
while(1) {
while((r = read(fd, header+header_length,
sizeof(header)-header_length)) == -1 && errno == EINTR);
if(r == -1) {
perror("read");
return -1;
} else if(r == 0) {
fprintf(stderr, "HTTP Handshake: Got EOF");
return -1;
} else {
header_length += r;
if(header_length >= 4 &&
memcmp(header+header_length-4, "\r\n\r\n", 4) == 0) {
break;
} else if(header_length == sizeof(header)) {
fprintf(stderr, "HTTP Handshake: Too large HTTP headers");
return -1;
}
}
}
if(http_header_find_field_value(header, "Upgrade", "websocket") == NULL ||
http_header_find_field_value(header, "Connection", "Upgrade") == NULL ||
(keyhdstart = http_header_find_field_value(header, "Sec-WebSocket-Key", NULL)) == NULL) {
fprintf(stderr, "HTTP Handshake: Missing required header fields");
return -1;
}
for(; *keyhdstart == ' '; ++keyhdstart);
keyhdend = keyhdstart;
for(; *keyhdend != '\r' && *keyhdend != ' '; ++keyhdend);
if(keyhdend-keyhdstart != 24) {
printf("%s\n", keyhdstart);
fprintf(stderr, "HTTP Handshake: Invalid value in Sec-WebSocket-Key");
return -1;
}
create_accept_key(accept_key, keyhdstart);
snprintf(res_header, sizeof(res_header),
"HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: websocket\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"\r\n", accept_key);
res_header_length = strlen(res_header);
while(res_header_sent < res_header_length) {
while((r = write(fd, res_header+res_header_sent,
res_header_length-res_header_sent)) == -1 &&
errno == EINTR);
if(r == -1) {
perror("write");
return -1;
} else {
res_header_sent += r;
}
}
return 0;
}
/*
* \brief Performs simple HTTP handshake. *fd* is the file descriptor of the
* connection to the client. This function returns 0 if it succeeds,
* or returns -1.
*/
static int http_handshake(int sockfd)
{
char header[16384], accept_key[29], res_header[256];
char *keyhdstart, *keyhdend;
size_t header_length = 0, res_header_sent = 0, res_header_length;
ssize_t ret;
fd_set set;
struct timeval timeout_tv, start_tv, current_tv;
/* Get current time */
gettimeofday(&start_tv, NULL);
/* Set default timeout */
timeout_tv.tv_sec = VRS_TIMEOUT;
timeout_tv.tv_usec = 0;
/* Try to read whole header without blocking read, use select and
* timeout */
while(1) {
FD_ZERO(&set);
FD_SET(sockfd, &set);
if( (ret = select(sockfd + 1, &set, NULL, NULL, &timeout_tv)) == -1 ) {
v_print_log(VRS_PRINT_ERROR, "%s:%s():%d select(): %s\n",
__FILE__, __FUNCTION__, __LINE__, strerror(errno));
return -1;
/* Was event on the listen socket */
} else if(ret > 0) {
if(FD_ISSET(sockfd, &set)) {
ret = read(sockfd,
header + header_length,
sizeof(header) - header_length);
if(ret == -1) {
v_print_log(VRS_PRINT_ERROR, "read(): %s\n", strerror(errno));
return -1;
} else if(ret == 0) {
v_print_log(VRS_PRINT_ERROR,
"HTTP Handshake: Got EOF");
return -1;
} else {
header_length += ret;
/* Was end of HTTP header reached? */
if(header_length >= 4 &&
memcmp(header + header_length - 4, "\r\n\r\n", 4) == 0)
{
break;
} else if(header_length == sizeof(header)) {
v_print_log(VRS_PRINT_ERROR,
"HTTP Handshake: Too large HTTP headers\n");
return -1;
}
}
}
}
gettimeofday(¤t_tv, NULL);
/* Update timeout */
timeout_tv.tv_sec = VRS_TIMEOUT - (current_tv.tv_sec - start_tv.tv_sec);
timeout_tv.tv_usec = 0;
/* Where there is no elapsing time, then exit handshake */
if(timeout_tv.tv_sec <= 0) {
v_print_log(VRS_PRINT_DEBUG_MSG,
"HTTP Handshake: Timed out\n");
return -1;
}
}
header[header_length] = '\0';
v_print_log(VRS_PRINT_DEBUG_MSG,
"HTTP Handshake: received request: %s\n",
header);
/* Check if required HTTP headers were received in the request */
/* Header has to contain field "Upgrade: websocket" */
if(http_header_find_field_value(header, "Upgrade", "websocket") == NULL) {
v_print_log(VRS_PRINT_ERROR,
"HTTP Handshake: Missing required header field 'Upgrade: websocket'\n");
return -1;
}
/* Header has to contain field "Connection: Upgrade" */
if(http_header_find_field_value(header, "Connection", "Upgrade") == NULL) {
v_print_log(VRS_PRINT_ERROR,
"HTTP Handshake: Missing required header field 'Connection: Upgrade'\n");
return -1;
}
/* Client has to send field Sec-WebSocket-Key in HTTP header */
if( (keyhdstart = http_header_find_field_value(header, "Sec-WebSocket-Key",
NULL)) == NULL)
{
v_print_log(VRS_PRINT_ERROR,
"HTTP Handshake: Missing required header field 'Sec-WebSocket-Key: SOME_SECRET_KEY'\n");
return -1;
}
/* Requested protocol name has to be equal to "v1.verse.tul.cz" */
if( http_header_find_field_value(header, "Sec-WebSocket-Protocol",
WEB_SOCKET_PROTO_NAME) == NULL)
{
v_print_log(VRS_PRINT_ERROR,
"HTTP Handshake: Missing required header field 'Sec-WebSocket-Protocol: %s'\n",
WEB_SOCKET_PROTO_NAME);
return -1;
}
/* Check the length of WebSocket key */
for(; *keyhdstart == ' '; ++keyhdstart);
keyhdend = keyhdstart;
for(; *keyhdend != '\r' && *keyhdend != ' '; ++keyhdend);
if(keyhdend - keyhdstart != WS_CLIENT_KEY_LEN) {
v_print_log(VRS_PRINT_ERROR,
"HTTP Handshake: Invalid value in Sec-WebSocket-Key\n");
return -1;
}
/* Create accepted key */
create_accept_key(accept_key, keyhdstart);
/* Create response for client */
snprintf(res_header, sizeof(res_header),
"HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: websocket\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"Sec-WebSocket-Protocol: %s\r\n"
"\r\n",
accept_key,
WEB_SOCKET_PROTO_NAME);
/* Send response to the client */
res_header_length = strlen(res_header);
while(res_header_sent < res_header_length) {
while((ret = write(sockfd, res_header + res_header_sent,
res_header_length - res_header_sent)) == -1 &&
errno == EINTR);
if(ret == -1) {
v_print_log(VRS_PRINT_ERROR, "write(): %s\n", strerror(errno));
return -1;
} else {
res_header_sent += ret;
}
}
v_print_log(VRS_PRINT_DEBUG_MSG, "HTTP Handshake: sent response\n");
return 0;
}
