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/*
* Copyright (C) 2016 "IoT.bzh"
* Author: José Bollo <jose.bollo@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define _GNU_SOURCE
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <assert.h>
#include <errno.h>
#include <sys/uio.h>
#include <string.h>
#include <stdarg.h>
#include <systemd/sd-event.h>
#include "websock.h"
#include "afb-ws.h"
#include "afb-common.h"
/*
* declaration of the websock interface for afb-ws
*/
static ssize_t aws_writev(struct afb_ws *ws, const struct iovec *iov, int iovcnt);
static ssize_t aws_readv(struct afb_ws *ws, const struct iovec *iov, int iovcnt);
static void aws_on_close(struct afb_ws *ws, uint16_t code, size_t size);
static void aws_on_text(struct afb_ws *ws, int last, size_t size);
static void aws_on_binary(struct afb_ws *ws, int last, size_t size);
static void aws_on_continue(struct afb_ws *ws, int last, size_t size);
static void aws_on_readable(struct afb_ws *ws);
static void aws_on_error(struct afb_ws *ws, uint16_t code, const void *data, size_t size);
static struct websock_itf aws_itf = {
.writev = (void*)aws_writev,
.readv = (void*)aws_readv,
.on_ping = NULL,
.on_pong = NULL,
.on_close = (void*)aws_on_close,
.on_text = (void*)aws_on_text,
.on_binary = (void*)aws_on_binary,
.on_continue = (void*)aws_on_continue,
.on_extension = NULL,
.on_error = (void*)aws_on_error
};
/*
* a common scheme of buffer handling
*/
struct buf
{
char *buffer;
size_t size;
};
/*
* the state
*/
enum state
{
waiting,
reading_text,
reading_binary
};
/*
* the afb_ws structure
*/
struct afb_ws
{
int fd; /* the socket file descriptor */
enum state state; /* current state */
const struct afb_ws_itf *itf; /* the callback interface */
void *closure; /* closure when calling the callbacks */
struct websock *ws; /* the websock handler */
sd_event_source *evsrc; /* the event source for the socket */
struct buf buffer; /* the last read fragment */
};
/*
* Returns the current buffer of 'ws' that is reset.
*/
static inline struct buf aws_pick_buffer(struct afb_ws *ws)
{
struct buf result = ws->buffer;
ws->buffer.buffer = NULL;
ws->buffer.size = 0;
return result;
}
/*
* Disconnect the websocket 'ws' and calls on_hangup if
* 'call_on_hangup' is not null.
*/
static void aws_disconnect(struct afb_ws *ws, int call_on_hangup)
{
struct websock *wsi = ws->ws;
if (wsi != NULL) {
ws->ws = NULL;
sd_event_source_unref(ws->evsrc);
ws->evsrc = NULL;
websock_destroy(wsi);
free(aws_pick_buffer(ws).buffer);
ws->state = waiting;
if (call_on_hangup && ws->itf->on_hangup)
ws->itf->on_hangup(ws->closure);
}
}
static int io_event_callback(sd_event_source *src, int fd, uint32_t revents, void *ws)
{
if ((revents & EPOLLIN) != 0)
aws_on_readable(ws);
if ((revents & EPOLLHUP) != 0)
afb_ws_hangup(ws);
return 0;
}
/*
* Creates the afb_ws structure for the file descritor
* 'fd' and the callbacks described by the interface 'itf'
* and its 'closure'.
*
* Returns the handle for the afb_ws created or NULL on error.
*/
struct afb_ws *afb_ws_create(int fd, const struct afb_ws_itf *itf, void *closure)
{
int rc;
struct afb_ws *result;
assert(fd >= 0);
/* allocation */
result = malloc(sizeof * result);
if (result == NULL)
goto error;
/* init */
result->fd = fd;
result->state = waiting;
result->itf = itf;
result->closure = closure;
result->buffer.buffer = NULL;
result->buffer.size = 0;
/* creates the websocket */
result->ws = websock_create_v13(&aws_itf, result);
if (result->ws == NULL)
goto error2;
/* creates the evsrc */
rc = sd_event_add_io(afb_common_get_event_loop(), &result->evsrc, result->fd, EPOLLIN, io_event_callback, result);
if (rc < 0) {
errno = -rc;
goto error3;
}
return result;
error3:
websock_destroy(result->ws);
error2:
free(result);
error:
return NULL;
}
/*
* Destroys the websocket 'ws'
* It first hangup (but without calling on_hangup for safety reasons)
* if needed.
*/
void afb_ws_destroy(struct afb_ws *ws)
{
aws_disconnect(ws, 0);
free(ws);
}
/*
* Hangup the websocket 'ws'
*/
void afb_ws_hangup(struct afb_ws *ws)
{
aws_disconnect(ws, 1);
}
/*
* Sends a 'close' command to the endpoint of 'ws' with the 'code' and the
* 'reason' (that can be NULL and that else should not be greater than 123
* characters).
* Returns 0 on success or -1 in case of error.
*/
int afb_ws_close(struct afb_ws *ws, uint16_t code, const char *reason)
{
if (ws->ws == NULL) {
/* disconnected */
errno = EPIPE;
return -1;
}
return websock_close(ws->ws, code, reason, reason == NULL ? 0 : strlen(reason));
}
/*
* Sends a 'close' command to the endpoint of 'ws' with the 'code' and the
* 'reason' (that can be NULL and that else should not be greater than 123
* characters).
* Raise an error after 'close' command is sent.
* Returns 0 on success or -1 in case of error.
*/
int afb_ws_error(struct afb_ws *ws, uint16_t code, const char *reason)
{
if (ws->ws == NULL) {
/* disconnected */
errno = EPIPE;
return -1;
}
return websock_error(ws->ws, code, reason, reason == NULL ? 0 : strlen(reason));
}
/*
* Sends a 'text' of 'length' to the endpoint of 'ws'.
* Returns 0 on success or -1 in case of error.
*/
int afb_ws_text(struct afb_ws *ws, const char *text, size_t length)
{
if (ws->ws == NULL) {
/* disconnected */
errno = EPIPE;
return -1;
}
return websock_text(ws->ws, 1, text, length);
}
/*
* Sends a variable list of texts to the endpoint of 'ws'.
* Returns 0 on success or -1 in case of error.
*/
int afb_ws_texts(struct afb_ws *ws, ...)
{
va_list args;
struct iovec ios[32];
int count;
const char *s;
if (ws->ws == NULL) {
/* disconnected */
errno = EPIPE;
return -1;
}
count = 0;
va_start(args, ws);
s = va_arg(args, const char *);
while (s != NULL) {
if (count == 32) {
errno = EINVAL;
return -1;
}
ios[count].iov_base = (void*)s;
ios[count].iov_len = strlen(s);
count++;
s = va_arg(args, const char *);
}
va_end(args);
return websock_text_v(ws->ws, 1, ios, count);
}
/*
* Sends a binary 'data' of 'length' to the endpoint of 'ws'.
* Returns 0 on success or -1 in case of error.
*/
int afb_ws_binary(struct afb_ws *ws, const void *data, size_t length)
{
if (ws->ws == NULL) {
/* disconnected */
errno = EPIPE;
return -1;
}
return websock_binary(ws->ws, 1, data, length);
}
/*
* callback for writing data
*/
static ssize_t aws_writev(struct afb_ws *ws, const struct iovec *iov, int iovcnt)
{
ssize_t rc;
do {
rc = writev(ws->fd, iov, iovcnt);
} while(rc == -1 && errno == EINTR);
return rc;
}
/*
* callback for reading data
*/
static ssize_t aws_readv(struct afb_ws *ws, const struct iovec *iov, int iovcnt)
{
ssize_t rc;
do {
rc = readv(ws->fd, iov, iovcnt);
} while(rc == -1 && errno == EINTR);
if (rc == 0) {
errno = EPIPE;
rc = -1;
}
return rc;
}
/*
* callback on incoming data
*/
static void aws_on_readable(struct afb_ws *ws)
{
int rc;
assert(ws->ws != NULL);
rc = websock_dispatch(ws->ws);
if (rc < 0 && errno == EPIPE)
afb_ws_hangup(ws);
}
/*
* Reads from the websocket handled by 'ws' data of length 'size'
* and append it to the current buffer of 'ws'.
* Returns 0 in case of error or 1 in case of success.
*/
static int aws_read(struct afb_ws *ws, size_t size)
{
ssize_t sz;
char *buffer;
if (size != 0) {
buffer = realloc(ws->buffer.buffer, ws->buffer.size + size + 1);
if (buffer == NULL)
return 0;
ws->buffer.buffer = buffer;
sz = websock_read(ws->ws, &buffer[ws->buffer.size], size);
if ((size_t)sz != size)
return 0;
ws->buffer.size += size;
}
return 1;
}
/*
* Callback when 'close' command received from 'ws' with 'code' and 'size'.
*/
static void aws_on_close(struct afb_ws *ws, uint16_t code, size_t size)
{
struct buf b;
ws->state = waiting;
free(aws_pick_buffer(ws).buffer);
if (ws->itf->on_close == NULL) {
websock_drop(ws->ws);
afb_ws_hangup(ws);
} else if (!aws_read(ws, size))
ws->itf->on_close(ws->closure, code, NULL, 0);
else {
b = aws_pick_buffer(ws);
ws->itf->on_close(ws->closure, code, b.buffer, b.size);
}
}
/*
* Drops any incoming data and send an error of 'code'
*/
static void aws_drop_error(struct afb_ws *ws, uint16_t code)
{
ws->state = waiting;
free(aws_pick_buffer(ws).buffer);
websock_drop(ws->ws);
websock_error(ws->ws, code, NULL, 0);
}
/*
* Reads either text or binary data of 'size' from 'ws' eventually 'last'.
*/
static void aws_continue(struct afb_ws *ws, int last, size_t size)
{
struct buf b;
int istxt;
if (!aws_read(ws, size))
aws_drop_error(ws, WEBSOCKET_CODE_ABNORMAL);
else if (last) {
istxt = ws->state == reading_text;
ws->state = waiting;
b = aws_pick_buffer(ws);
b.buffer[b.size] = 0;
(istxt ? ws->itf->on_text : ws->itf->on_binary)(ws->closure, b.buffer, b.size);
}
}
/*
* Callback when 'text' message received from 'ws' with 'size' and possibly 'last'.
*/
static void aws_on_text(struct afb_ws *ws, int last, size_t size)
{
if (ws->state != waiting)
aws_drop_error(ws, WEBSOCKET_CODE_PROTOCOL_ERROR);
else if (ws->itf->on_text == NULL)
aws_drop_error(ws, WEBSOCKET_CODE_CANT_ACCEPT);
else {
ws->state = reading_text;
aws_continue(ws, last, size);
}
}
/*
* Callback when 'binary' message received from 'ws' with 'size' and possibly 'last'.
*/
static void aws_on_binary(struct afb_ws *ws, int last, size_t size)
{
if (ws->state != waiting)
aws_drop_error(ws, WEBSOCKET_CODE_PROTOCOL_ERROR);
else if (ws->itf->on_binary == NULL)
aws_drop_error(ws, WEBSOCKET_CODE_CANT_ACCEPT);
else {
ws->state = reading_binary;
aws_continue(ws, last, size);
}
}
/*
* Callback when 'close' command received from 'ws' with 'code' and 'size'.
*/
static void aws_on_continue(struct afb_ws *ws, int last, size_t size)
{
if (ws->state == waiting)
aws_drop_error(ws, WEBSOCKET_CODE_PROTOCOL_ERROR);
else
aws_continue(ws, last, size);
}
/*
* Callback when 'close' command is sent to 'ws' with 'code' and 'size'.
*/
static void aws_on_error(struct afb_ws *ws, uint16_t code, const void *data, size_t size)
{
if (ws->itf->on_error != NULL)
ws->itf->on_error(ws->closure, code, data, size);
else
afb_ws_hangup(ws);
}
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