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/**
* @file
* @author Pawel Zubrycki <paw.zubr@gmail.com>
* @author 2013 Stefan Radomski (stefan.radomski@cs.tu-darmstadt.de)
* @copyright Simplified BSD
*
* @cond
* This program is free software: you can redistribute it and/or modify
* it under the terms of the FreeBSD license as published by the FreeBSD
* project.
*
* 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.
*
* You should have received a copy of the FreeBSD license along with this
* program. If not, see <http://www.opensource.org/licenses/bsd-license>.
* @endcond
*/
#include "evws.h"
#include <stdlib.h>
#include <string.h>
#include <event2/buffer.h>
#include <event2/bufferevent.h>
#include "uscxml/util/SHA1.h"
#include "uscxml/util/Base64.h"
#ifdef _WIN32
char* strsep(char** stringp, const char* delim) {
char* start = *stringp;
char* p;
p = (start != NULL) ? strpbrk(start, delim) : NULL;
if (p == NULL)
{
*stringp = NULL;
}
else
{
*p = '\0';
*stringp = p + 1;
}
return start;
}
#define strdup _strdup
#endif
static int evws_parse_first_line(struct evws_connection *conn, char *line);
static int evws_parse_header_line(char *line, char **skey, char **svalue);
// Callbacks
static void cb_accept(struct evconnlistener *listener, evutil_socket_t fd, struct sockaddr *address, int socklen, void *ctx);
static void cb_read_handshake(struct bufferevent *bev, void *arg);
static void cb_read_frame(struct bufferevent *bev, void *arg);
#define WS_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
struct evws *evws_new(struct event_base *base) {
struct evws *ret_obj = (struct evws*)calloc(1, sizeof(struct evws));
ret_obj->base = base;
ret_obj->listener = NULL;
(&ret_obj->connections)->tqh_first = NULL;
(&ret_obj->connections)->tqh_last = &((&ret_obj->connections)->tqh_first);
(&ret_obj->callbacks)->tqh_first = NULL;
(&ret_obj->callbacks)->tqh_last = &((&ret_obj->callbacks)->tqh_first);
return ret_obj;
}
void evws_free(struct evws *ptr) {
// Tu wiecej czyszczenia
free(ptr);
}
evutil_socket_t evws_bind_socket(struct evws * ws, unsigned short port) {
struct sockaddr_in sin;
// Creating serverside socket
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = htonl(0);
sin.sin_port = htons(port);
if(!(ws->listener = evconnlistener_new_bind(ws->base,
cb_accept,
ws,
LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE|LEV_OPT_THREADSAFE,
-1,
(struct sockaddr*)&sin, sizeof(sin)))
) {
return 0;
}
return evconnlistener_get_fd(ws->listener);
}
int evws_set_cb(struct evws * ws, const char * uri, cb_frame_type message_cb, cb_type connect_cb, void * arg) {
struct evws_cb *ws_cb = NULL;
for (ws_cb = (&ws->callbacks)->tqh_first; ws_cb; ws_cb = ws_cb->next.tqe_next) {
if (strcmp(ws_cb->uri, uri) == 0)
return (-1);
}
if((ws_cb = (struct evws_cb*)calloc(1, sizeof(struct evws_cb))) == NULL) {
return (-2);
}
ws_cb->uri = (char*)strdup(uri);
ws_cb->msg_cb = message_cb;
ws_cb->conn_cb = connect_cb;
ws_cb->cb_arg = arg;
// TAILQ_INSERT_TAIL
ws_cb->next.tqe_next = NULL;
ws_cb->next.tqe_prev = (&ws->callbacks)->tqh_last;
*(&ws->callbacks)->tqh_last = ws_cb;
(&ws->callbacks)->tqh_last = &(ws_cb->next.tqe_next);
return (0);
}
cb_frame_type evws_set_gencb(struct evws *ws, cb_frame_type cb, void * arg) {
cb_frame_type old_cb = ws->gencb;
ws->gencb = cb;
ws->gencb_arg = arg;
return old_cb;
}
// Broadcast data to all buffers associated with pattern
void evws_broadcast(struct evws *ws, const char *uri, enum evws_opcode opcode, const char *data, uint64_t length) {
struct evws_connection *ws_connection;
for ((ws_connection) = (&ws->connections)->tqh_first; ws_connection; ws_connection = ws_connection->next.tqe_next) {
if (strcmp(ws_connection->uri, uri) == 0)
evws_send_data(ws_connection, opcode, data, length);
}
}
int evws_is_valid_connection(struct evws *ws, struct evws_connection *conn) {
struct evws_connection *ws_connection;
for ((ws_connection) = (&ws->connections)->tqh_first; ws_connection; ws_connection = ws_connection->next.tqe_next) {
if (ws_connection == conn)
return 1;
}
return 0;
}
// Error callback
static void cb_error(struct bufferevent *bev, short what, void *ctx) {
struct evws_connection *conn = ctx;
if (conn->next.tqe_next != NULL) {
conn->next.tqe_next->next.tqe_prev = conn->next.tqe_prev;
} else {
(&(conn->ws->connections))->tqh_last = conn->next.tqe_prev;
}
*(conn)->next.tqe_prev = conn->next.tqe_next;
evws_connection_free(conn);
}
//Callback to accept
static void cb_accept(struct evconnlistener *listener, evutil_socket_t fd, struct sockaddr *address, int socklen, void *arg) {
struct evws *ws = arg;
struct evws_connection *ws_conn = evws_connection_new(ws, fd);
bufferevent_setcb(ws_conn->bufev, cb_read_handshake, NULL, cb_error, ws_conn);
bufferevent_enable(ws_conn->bufev, EV_READ);
}
int evws_parse_first_line(struct evws_connection *conn, char *line) {
char *method;
char *uri;
char *version;
/* Parse the request line */
method = strsep(&line, " ");
if (line == NULL)
return (-1);
uri = strsep(&line, " ");
if (line == NULL)
return (-1);
version = strsep(&line, " ");
if (line != NULL)
return (-1);
(void)method;
(void)version;
if ((conn->uri = strdup(uri)) == NULL) {
return (-1);
}
return (0);
}
// Callback to read handshake
void cb_read_handshake(struct bufferevent *bev, void *arg) {
struct evws_connection *ws_conn = arg;
char *line, *skey, *svalue;
struct evbuffer *buffer = bufferevent_get_input(bev);
struct evws_header *header = NULL;
size_t line_length;
char *key = NULL;
char *host = NULL;
char *origin = NULL;
SHA1Context sha1;
char chksumSha1[21];
int i;
int md5End = 0;
char chksumBase64[200];
base64_encodestate* base64Ctx = NULL;
switch(ws_conn->state) {
case 0:
line = evbuffer_readln(buffer, &line_length, EVBUFFER_EOL_CRLF);
evws_parse_first_line(ws_conn, line);
ws_conn->state = EVWS_FIRSTLINE_READ;
free(line);
case EVWS_FIRSTLINE_READ:
while ((line = evbuffer_readln(buffer, &line_length, EVBUFFER_EOL_CRLF)) != NULL) {
if (*line == '\0') { /* Last header - Done */
free(line);
ws_conn->state = EVWS_HEADER_READ;
break;
}
evws_parse_header_line(line, &skey, &svalue);
if(strcmp(skey, "Sec-WebSocket-Key") == 0) {
key = strdup(svalue);
} else if(strcmp(skey, "Host") == 0) {
host = strdup(svalue);
} else if(strcmp(skey, "Origin") == 0) {
origin = strdup(svalue);
}
header = evws_header_new(skey, svalue);
// TAILQ_INSERT_TAIL
header->next.tqe_next = NULL;
header->next.tqe_prev = (&ws_conn->headers)->tqh_last;
*(&ws_conn->headers)->tqh_last = header;
(&ws_conn->headers)->tqh_last = &(header->next.tqe_next);
free(line);
}
default:
break;
};
if (key == NULL)
return;
// -- SHA1
SHA1Reset(&sha1);
SHA1Input(&sha1, (const unsigned char*)key, 24);
SHA1Input(&sha1, (const unsigned char*)WS_GUID, 36);
SHA1Result(&sha1);
for (i = 0; i < 5; i++) {
chksumSha1[i * 4 + 0] = (sha1.Message_Digest[i] >> 24) & 0xff;
chksumSha1[i * 4 + 1] = (sha1.Message_Digest[i] >> 16) & 0xff;
chksumSha1[i * 4 + 2] = (sha1.Message_Digest[i] >> 8) & 0xff;
chksumSha1[i * 4 + 3] = (sha1.Message_Digest[i] >> 0) & 0xff;
}
// printf("%s\n", chksumSha1);
// -- BASE64
base64Ctx = malloc(sizeof(base64_encodestate));
base64_init_encodestate(base64Ctx);
md5End += base64_encode_block(chksumSha1, 20, chksumBase64, base64Ctx);
md5End += base64_encode_blockend(&chksumBase64[md5End], base64Ctx);
// blockend writes unneccessary \n
chksumBase64[md5End - 1] = 0;
free(base64Ctx);
free(key);
free(host);
free(origin);
evbuffer_add_printf(bufferevent_get_output(ws_conn->bufev),
"HTTP/1.1 101 Web Socket Protocol Handshake\r\n"
"Upgrade: WebSocket\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"Server: uSCXML\r\n"
"Access-Control-Allow-Origin: *\r\n"
"Access-Control-Allow-Credentials: true\r\n"
"Access-Control-Allow-Headers: content-type\r\n"
"Access-Control-Allow-Headers: authorization\r\n"
"Access-Control-Allow-Headers: x-websocket-extensions\r\n"
"Access-Control-Allow-Headers: x-websocket-version\r\n"
"Access-Control-Allow-Headers: x-websocket-protocol\r\n"
"\r\n",
chksumBase64
);
bufferevent_setcb(ws_conn->bufev, cb_read_frame, ((void*)0), cb_error, ws_conn);
ws_conn->next.tqe_next = NULL;
ws_conn->next.tqe_prev = (&(ws_conn->ws->connections))->tqh_last;
*(&(ws_conn->ws->connections))->tqh_last = ws_conn;
(&(ws_conn->ws->connections))->tqh_last = &(ws_conn->next.tqe_next);
{
struct evws_cb *ws_cb;
for (ws_cb = ((&ws_conn->ws->callbacks))->tqh_first; ws_cb; ws_cb = ws_cb->next.tqe_next) {
if (strcmp(ws_cb->uri, ws_conn->uri) == 0) {
if(ws_cb->conn_cb != ((void*)0))
ws_cb->conn_cb(ws_conn, ((void*)0), 0, ws_cb->cb_arg);
return;
}
}
}
}
int evws_parse_header_line(char *line, char **skey, char **svalue)
{
*svalue = line;
*skey = strsep(svalue, ":");
if (*svalue == NULL)
return -1;
*svalue += strspn(*svalue, " ");
return (0);
}
// Callback to read sent data
void cb_read_frame(struct bufferevent *bev, void *arg)
{
struct evws_connection *conn = arg;
struct evws *ws = conn->ws;
char readbuf[2048]; // make sure a MTU fits
int size = 0;
struct evbuffer *buffer = bufferevent_get_input(bev);
while ((size = evbuffer_remove(buffer, readbuf, sizeof(readbuf))) > 0) {
char* dataPtr = readbuf;
NEXT_FRAME:
if (conn->frame == NULL) {
// data starts with the first byte of a new frame
conn->frame = evws_frame_new();
conn->frame->fin = (dataPtr[0] >> 7) & 1;
conn->frame->rsv = (dataPtr[0] >> 4) & 7;
conn->frame->opcode = dataPtr[0] & 0xfu;
conn->frame->state = EVWS_OPCODE_READ;
dataPtr++;
}
if (size - (dataPtr - readbuf) == 0)
continue;
if (conn->frame->state == EVWS_OPCODE_READ) { // we already read the first byte
conn->frame->has_mask = (dataPtr[0] >> 7) & 1;
if (conn->frame->has_mask)
conn->frame->mask_bytes = 4;
conn->frame->size = dataPtr[0] & 0x7fu;
dataPtr++;
if(conn->frame->size == 126) {
conn->frame->payload_bytes = 2;
conn->frame->size = 0;
} else if(conn->frame->size == 127) {
conn->frame->payload_bytes = 8;
conn->frame->size = 0;
} else {
conn->frame->payload_bytes = 0;
}
conn->frame->state = EVWS_PAYLOAD_LENGTH_LENGTH_READ;
}
if (size - (dataPtr - readbuf) == 0)
continue;
if (conn->frame->state == EVWS_PAYLOAD_LENGTH_LENGTH_READ) { // we already read the first byte
while(conn->frame->payload_bytes > 0 && // need to add more bytes to the payload length
(size - (dataPtr - readbuf) > 0)) { // and bytes still available
// length is in MSB network order - shift to left and add
conn->frame->size = (conn->frame->size << 8) + (uint8_t)dataPtr[0];
conn->frame->payload_bytes--;
dataPtr++;
}
if (conn->frame->payload_bytes == 0) {
conn->frame->state = EVWS_PAYLOAD_LENGTH_READ;
if (!conn->frame->has_mask)
conn->frame->state = EVWS_MASKING_KEY_READ;
}
conn->frame->data = (char*)malloc(conn->frame->size);
}
if (size - (dataPtr - readbuf) == 0)
continue;
if (conn->frame->state == EVWS_PAYLOAD_LENGTH_READ && // we already read the complete payload
conn->frame->has_mask) {
while (conn->frame->mask_bytes > 0 && // bytes for the frame mask
(size - (dataPtr - readbuf) > 0)) { // still some available
conn->frame->mask[4 - conn->frame->mask_bytes] = dataPtr[0];
conn->frame->mask_bytes--;
dataPtr++;
if (conn->frame->mask_bytes == 0)
conn->frame->state = EVWS_MASKING_KEY_READ;
}
}
if (size - (dataPtr - readbuf) == 0)
continue;
if (conn->frame->state == EVWS_MASKING_KEY_READ) { // we read all of the header
size_t remaining = size - (dataPtr - readbuf);
remaining = (remaining > conn->frame->size - conn->frame->payload_read ? conn->frame->size - conn->frame->payload_read : remaining);
if (conn->frame->has_mask) {
int i;
for (i = 0; i < remaining; i++) {
dataPtr[i] = dataPtr[i] ^ conn->frame->mask[conn->frame->mask_index];
conn->frame->mask_index++;
conn->frame->mask_index = conn->frame->mask_index % 4;
}
}
memcpy(conn->frame->data + conn->frame->payload_read, dataPtr, remaining);
conn->frame->payload_read += remaining;
dataPtr += remaining;
}
if (conn->frame->payload_read == conn->frame->size) {
// done reading this frame - invoke callbacks
struct evws_cb *ws_cb;
// TAILQ_FOREACH
for (ws_cb = ((&ws->callbacks))->tqh_first; ws_cb; ws_cb = (ws_cb->next.tqe_next)) {
if (strcmp(ws_cb->uri, conn->uri) == 0) {
if(ws_cb->msg_cb != ((void*)0)) {
ws_cb->msg_cb(conn, conn->frame, ws_cb->cb_arg);
}
}
}
ws->gencb(conn, conn->frame, ws->gencb_arg);
evws_frame_free(conn->frame);
conn->frame = NULL;
if (size - (dataPtr - readbuf) != 0) // there is more data in this packet
goto NEXT_FRAME;
}
}
}
void evws_send_data(struct evws_connection *conn, enum evws_opcode opcode, const char *data, uint64_t length) {
char* writePtr = NULL;
char *sendbuf = NULL;
struct evbuffer *buffer = NULL;
sendbuf = malloc(length + 10); // payload + header without masking key
if(sendbuf == NULL)
return;
writePtr = sendbuf;
writePtr[0] = (1 << 7); // set fin header and zero out RSV
writePtr[0] += opcode; // set opcode
writePtr++;
writePtr[0] = (0 << 7); // we don't mask replies
if (length < 126) {
writePtr[0] += (uint8_t)length;
writePtr++;
} else if(length < (1 << 16)) {
writePtr[0] = 126;
writePtr[1] = (((uint16_t)length) >> 8) & 0xff;
writePtr[2] = ((uint16_t)length) & 0xff;
writePtr += 3;
} else if(length < (1ull << 63)) {
writePtr[0] = 126;
// integer division and bitmask ought to be endian agnostic
writePtr[1] = (length / 0x0100000000000000) & 0xff;
writePtr[2] = (length / 0x0001000000000000) & 0xff;
writePtr[3] = (length / 0x0000010000000000) & 0xff;
writePtr[4] = (length / 0x0000000100000000) & 0xff;
writePtr[5] = (length / 0x0000000001000000) & 0xff;
writePtr[6] = (length / 0x0000000000010000) & 0xff;
writePtr[7] = (length / 0x0000000000000100) & 0xff;
writePtr[8] = (length / 0x0000000000000001) & 0xff;
writePtr += 9;
}
memcpy(writePtr, data, length);
writePtr += length;
buffer = bufferevent_get_output(conn->bufev);
evbuffer_add(buffer, sendbuf, writePtr - sendbuf);
free(sendbuf);
}
// --- new and free pairs ---
struct evws_connection* evws_connection_new(struct evws *ws, evutil_socket_t fd) {
struct evws_connection* conn = calloc(1, sizeof(struct evws_connection));
conn->ws = ws;
conn->fd = fd;
conn->uri = ((void*)0);
conn->bufev = bufferevent_socket_new(ws->base, fd, BEV_OPT_CLOSE_ON_FREE);
conn->state = 0;
conn->frame = ((void*)0);
(&conn->headers)->tqh_first = NULL;
(&conn->headers)->tqh_last = &(((&conn->headers))->tqh_first);
return conn;
}
void evws_connection_free(struct evws_connection *conn) {
struct evws_header *header;
bufferevent_free(conn->bufev);
if(conn->uri != ((void*)0))
free(conn->uri);
for (header = (&conn->headers)->tqh_first; header; header = header->next.tqe_next) {
evws_header_free(header);
}
free(conn);
}
struct evws_frame *evws_frame_new() {
struct evws_frame *frame = calloc(1, sizeof(struct evws_frame));
return frame;
}
void evws_frame_free(struct evws_frame *frame) {
if (frame->data)
free(frame->data);
free(frame);
}
struct evws_header *evws_header_new(char *key, char *value)
{
struct evws_header *head = calloc(1, sizeof(struct evws_header));
head->key = strdup(key);
head->value = strdup(value);
return head;
}
void evws_header_free(struct evws_header *header) {
if(header->key != NULL)
free(header->key);
if(header->value != NULL)
free(header->value);
free(header);
}
char *evws_find_header(const struct wsheadersq *q, const char *key) {
struct evws_header *hdr;
char * ret = ((void*)0);
for (hdr = q->tqh_first; hdr; hdr = hdr->next.tqe_next) {
if(strcmp(hdr->key, key) == 0) {
ret = hdr->value;
break;
}
}
return ret;
}
|