asterisk/res/res_http_websocket.c

1556 lines
47 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2012, Digium, Inc.
*
* Joshua Colp <jcolp@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief WebSocket support for the Asterisk internal HTTP server
*
* \author Joshua Colp <jcolp@digium.com>
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/http.h"
#include "asterisk/astobj2.h"
#include "asterisk/strings.h"
#include "asterisk/file.h"
#include "asterisk/unaligned.h"
#include "asterisk/uri.h"
#include "asterisk/uuid.h"
#define AST_API_MODULE
#include "asterisk/http_websocket.h"
/*! \brief GUID used to compute the accept key, defined in the specifications */
#define WEBSOCKET_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
/*! \brief Length of a websocket's client key */
#define CLIENT_KEY_SIZE 16
/*! \brief Number of buckets for registered protocols */
#define MAX_PROTOCOL_BUCKETS 7
#ifdef LOW_MEMORY
/*! \brief Size of the pre-determined buffer for WebSocket frames */
#define MAXIMUM_FRAME_SIZE 8192
/*! \brief Default reconstruction size for multi-frame payload reconstruction. If exceeded the next frame will start a
* payload.
*/
#define DEFAULT_RECONSTRUCTION_CEILING 8192
/*! \brief Maximum reconstruction size for multi-frame payload reconstruction. */
#define MAXIMUM_RECONSTRUCTION_CEILING 8192
#else
/*! \brief Size of the pre-determined buffer for WebSocket frames */
#define MAXIMUM_FRAME_SIZE 65535
/*! \brief Default reconstruction size for multi-frame payload reconstruction. If exceeded the next frame will start a
* payload.
*/
#define DEFAULT_RECONSTRUCTION_CEILING MAXIMUM_FRAME_SIZE
/*! \brief Maximum reconstruction size for multi-frame payload reconstruction. */
#define MAXIMUM_RECONSTRUCTION_CEILING MAXIMUM_FRAME_SIZE
#endif
/*! \brief Maximum size of a websocket frame header
* 1 byte flags and opcode
* 1 byte mask flag + payload len
* 8 bytes max extended length
* 4 bytes optional masking key
* ... payload follows ...
* */
#define MAX_WS_HDR_SZ 14
#define MIN_WS_HDR_SZ 2
/*! \brief Structure definition for session */
struct ast_websocket {
struct ast_iostream *stream; /*!< iostream of the connection */
struct ast_sockaddr remote_address; /*!< Address of the remote client */
struct ast_sockaddr local_address; /*!< Our local address */
enum ast_websocket_opcode opcode; /*!< Cached opcode for multi-frame messages */
size_t payload_len; /*!< Length of the payload */
char *payload; /*!< Pointer to the payload */
size_t reconstruct; /*!< Number of bytes before a reconstructed payload will be returned and a new one started */
int timeout; /*!< The timeout for operations on the socket */
unsigned int secure:1; /*!< Bit to indicate that the transport is secure */
unsigned int closing:1; /*!< Bit to indicate that the session is in the process of being closed */
unsigned int close_sent:1; /*!< Bit to indicate that the session close opcode has been sent and no further data will be sent */
struct websocket_client *client; /*!< Client object when connected as a client websocket */
char session_id[AST_UUID_STR_LEN]; /*!< The identifier for the websocket session */
uint16_t close_status_code; /*!< Status code sent in a CLOSE frame upon shutdown */
char buf[MAXIMUM_FRAME_SIZE]; /*!< Fixed buffer for reading data into */
};
/*! \brief Hashing function for protocols */
static int protocol_hash_fn(const void *obj, const int flags)
{
const struct ast_websocket_protocol *protocol = obj;
const char *name = obj;
return ast_str_case_hash(flags & OBJ_KEY ? name : protocol->name);
}
/*! \brief Comparison function for protocols */
static int protocol_cmp_fn(void *obj, void *arg, int flags)
{
const struct ast_websocket_protocol *protocol1 = obj, *protocol2 = arg;
const char *protocol = arg;
return !strcasecmp(protocol1->name, flags & OBJ_KEY ? protocol : protocol2->name) ? CMP_MATCH | CMP_STOP : 0;
}
/*! \brief Destructor function for protocols */
static void protocol_destroy_fn(void *obj)
{
struct ast_websocket_protocol *protocol = obj;
ast_free(protocol->name);
}
/*! \brief Structure for a WebSocket server */
struct ast_websocket_server {
struct ao2_container *protocols; /*!< Container for registered protocols */
};
static void websocket_server_dtor(void *obj)
{
struct ast_websocket_server *server = obj;
ao2_cleanup(server->protocols);
server->protocols = NULL;
}
static struct ast_websocket_server *websocket_server_create_impl(void)
{
RAII_VAR(struct ast_websocket_server *, server, NULL, ao2_cleanup);
server = ao2_alloc(sizeof(*server), websocket_server_dtor);
if (!server) {
return NULL;
}
server->protocols = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
MAX_PROTOCOL_BUCKETS, protocol_hash_fn, NULL, protocol_cmp_fn);
if (!server->protocols) {
return NULL;
}
ao2_ref(server, +1);
return server;
}
static struct ast_websocket_server *websocket_server_internal_create(void)
{
return websocket_server_create_impl();
}
struct ast_websocket_server *AST_OPTIONAL_API_NAME(ast_websocket_server_create)(void)
{
return websocket_server_create_impl();
}
/*! \brief Destructor function for sessions */
static void session_destroy_fn(void *obj)
{
struct ast_websocket *session = obj;
if (session->stream) {
ast_websocket_close(session, session->close_status_code);
if (session->stream) {
ast_iostream_close(session->stream);
session->stream = NULL;
ast_verb(2, "WebSocket connection %s '%s' closed\n", session->client ? "to" : "from",
ast_sockaddr_stringify(&session->remote_address));
}
}
ao2_cleanup(session->client);
ast_free(session->payload);
}
struct ast_websocket_protocol *AST_OPTIONAL_API_NAME(ast_websocket_sub_protocol_alloc)(const char *name)
{
struct ast_websocket_protocol *protocol;
protocol = ao2_alloc(sizeof(*protocol), protocol_destroy_fn);
if (!protocol) {
return NULL;
}
protocol->name = ast_strdup(name);
if (!protocol->name) {
ao2_ref(protocol, -1);
return NULL;
}
protocol->version = AST_WEBSOCKET_PROTOCOL_VERSION;
return protocol;
}
int AST_OPTIONAL_API_NAME(ast_websocket_server_add_protocol)(struct ast_websocket_server *server, const char *name, ast_websocket_callback callback)
{
struct ast_websocket_protocol *protocol;
if (!server->protocols) {
return -1;
}
protocol = ast_websocket_sub_protocol_alloc(name);
if (!protocol) {
return -1;
}
protocol->session_established = callback;
if (ast_websocket_server_add_protocol2(server, protocol)) {
ao2_ref(protocol, -1);
return -1;
}
return 0;
}
int AST_OPTIONAL_API_NAME(ast_websocket_server_add_protocol2)(struct ast_websocket_server *server, struct ast_websocket_protocol *protocol)
{
struct ast_websocket_protocol *existing;
if (!server->protocols) {
return -1;
}
if (protocol->version != AST_WEBSOCKET_PROTOCOL_VERSION) {
ast_log(LOG_WARNING, "WebSocket could not register sub-protocol '%s': "
"expected version '%u', got version '%u'\n",
protocol->name, AST_WEBSOCKET_PROTOCOL_VERSION, protocol->version);
return -1;
}
ao2_lock(server->protocols);
/* Ensure a second protocol handler is not registered for the same protocol */
existing = ao2_find(server->protocols, protocol->name, OBJ_KEY | OBJ_NOLOCK);
if (existing) {
ao2_ref(existing, -1);
ao2_unlock(server->protocols);
return -1;
}
ao2_link_flags(server->protocols, protocol, OBJ_NOLOCK);
ao2_unlock(server->protocols);
ast_verb(2, "WebSocket registered sub-protocol '%s'\n", protocol->name);
ao2_ref(protocol, -1);
return 0;
}
int AST_OPTIONAL_API_NAME(ast_websocket_server_remove_protocol)(struct ast_websocket_server *server, const char *name, ast_websocket_callback callback)
{
struct ast_websocket_protocol *protocol;
if (!(protocol = ao2_find(server->protocols, name, OBJ_KEY))) {
return -1;
}
if (protocol->session_established != callback) {
ao2_ref(protocol, -1);
return -1;
}
ao2_unlink(server->protocols, protocol);
ao2_ref(protocol, -1);
ast_verb(2, "WebSocket unregistered sub-protocol '%s'\n", name);
return 0;
}
/*! \brief Perform payload masking for client sessions */
static void websocket_mask_payload(struct ast_websocket *session, char *frame, char *payload, uint64_t payload_size)
{
/* RFC 6455 5.1 - clients MUST mask frame data */
if (session->client) {
uint64_t i;
uint8_t mask_key_idx;
uint32_t mask_key = ast_random();
uint8_t length = frame[1] & 0x7f;
frame[1] |= 0x80; /* set mask bit to 1 */
/* The mask key octet position depends on the length */
mask_key_idx = length == 126 ? 4 : length == 127 ? 10 : 2;
put_unaligned_uint32(&frame[mask_key_idx], mask_key);
for (i = 0; i < payload_size; i++) {
payload[i] ^= ((char *)&mask_key)[i % 4];
}
}
}
/*! \brief Close function for websocket session */
int AST_OPTIONAL_API_NAME(ast_websocket_close)(struct ast_websocket *session, uint16_t reason)
{
enum ast_websocket_opcode opcode = AST_WEBSOCKET_OPCODE_CLOSE;
/* The header is either 2 or 6 bytes and the
* reason code takes up another 2 bytes */
char frame[8] = { 0, };
int header_size, fsize, res;
if (session->close_sent) {
return 0;
}
/* clients need space for an additional 4 byte masking key */
header_size = session->client ? 6 : 2;
fsize = header_size + 2;
frame[0] = opcode | 0x80;
frame[1] = 2; /* The reason code is always 2 bytes */
/* If no reason has been specified assume 1000 which is normal closure */
put_unaligned_uint16(&frame[header_size], htons(reason ? reason : 1000));
websocket_mask_payload(session, frame, &frame[header_size], 2);
session->closing = 1;
session->close_sent = 1;
ao2_lock(session);
ast_iostream_set_timeout_inactivity(session->stream, session->timeout);
res = ast_iostream_write(session->stream, frame, fsize);
ast_iostream_set_timeout_disable(session->stream);
/* If an error occurred when trying to close this connection explicitly terminate it now.
* Doing so will cause the thread polling on it to wake up and terminate.
*/
if (res != fsize) {
ast_iostream_close(session->stream);
session->stream = NULL;
ast_verb(2, "WebSocket connection %s '%s' forcefully closed due to fatal write error\n",
session->client ? "to" : "from", ast_sockaddr_stringify(&session->remote_address));
}
ao2_unlock(session);
return res == sizeof(frame);
}
static const char *opcode_map[] = {
[AST_WEBSOCKET_OPCODE_CONTINUATION] = "continuation",
[AST_WEBSOCKET_OPCODE_TEXT] = "text",
[AST_WEBSOCKET_OPCODE_BINARY] = "binary",
[AST_WEBSOCKET_OPCODE_CLOSE] = "close",
[AST_WEBSOCKET_OPCODE_PING] = "ping",
[AST_WEBSOCKET_OPCODE_PONG] = "pong",
};
static const char *websocket_opcode2str(enum ast_websocket_opcode opcode)
{
if (opcode < AST_WEBSOCKET_OPCODE_CONTINUATION ||
opcode > AST_WEBSOCKET_OPCODE_PONG) {
return "<unknown>";
} else {
return opcode_map[opcode];
}
}
/*! \brief Write function for websocket traffic */
int AST_OPTIONAL_API_NAME(ast_websocket_write)(struct ast_websocket *session, enum ast_websocket_opcode opcode, char *payload, uint64_t payload_size)
{
size_t header_size = 2; /* The minimum size of a websocket frame is 2 bytes */
char *frame;
uint64_t length;
uint64_t frame_size;
ast_debug(3, "Writing websocket %s frame, length %" PRIu64 "\n",
websocket_opcode2str(opcode), payload_size);
if (payload_size < 126) {
length = payload_size;
} else if (payload_size < (1 << 16)) {
length = 126;
/* We need an additional 2 bytes to store the extended length */
header_size += 2;
} else {
length = 127;
/* We need an additional 8 bytes to store the really really extended length */
header_size += 8;
}
if (session->client) {
/* Additional 4 bytes for the client masking key */
header_size += 4;
}
frame_size = header_size + payload_size;
frame = ast_alloca(frame_size + 1);
memset(frame, 0, frame_size + 1);
frame[0] = opcode | 0x80;
frame[1] = length;
/* Use the additional available bytes to store the length */
if (length == 126) {
put_unaligned_uint16(&frame[2], htons(payload_size));
} else if (length == 127) {
put_unaligned_uint64(&frame[2], htonll(payload_size));
}
memcpy(&frame[header_size], payload, payload_size);
websocket_mask_payload(session, frame, &frame[header_size], payload_size);
ao2_lock(session);
if (session->closing) {
ao2_unlock(session);
return -1;
}
ast_iostream_set_timeout_sequence(session->stream, ast_tvnow(), session->timeout);
if (ast_iostream_write(session->stream, frame, frame_size) != frame_size) {
ao2_unlock(session);
/* 1011 - server terminating connection due to not being able to fulfill the request */
ast_debug(1, "Closing WS with 1011 because we can't fulfill a write request\n");
ast_websocket_close(session, 1011);
return -1;
}
ast_iostream_set_timeout_disable(session->stream);
ao2_unlock(session);
return 0;
}
void AST_OPTIONAL_API_NAME(ast_websocket_reconstruct_enable)(struct ast_websocket *session, size_t bytes)
{
session->reconstruct = MIN(bytes, MAXIMUM_RECONSTRUCTION_CEILING);
}
void AST_OPTIONAL_API_NAME(ast_websocket_reconstruct_disable)(struct ast_websocket *session)
{
session->reconstruct = 0;
}
void AST_OPTIONAL_API_NAME(ast_websocket_ref)(struct ast_websocket *session)
{
ao2_ref(session, +1);
}
void AST_OPTIONAL_API_NAME(ast_websocket_unref)(struct ast_websocket *session)
{
ao2_cleanup(session);
}
int AST_OPTIONAL_API_NAME(ast_websocket_fd)(struct ast_websocket *session)
{
return session->closing ? -1 : ast_iostream_get_fd(session->stream);
}
int AST_OPTIONAL_API_NAME(ast_websocket_wait_for_input)(struct ast_websocket *session, int timeout)
{
return session->closing ? -1 : ast_iostream_wait_for_input(session->stream, timeout);
}
struct ast_sockaddr * AST_OPTIONAL_API_NAME(ast_websocket_remote_address)(struct ast_websocket *session)
{
return &session->remote_address;
}
struct ast_sockaddr * AST_OPTIONAL_API_NAME(ast_websocket_local_address)(struct ast_websocket *session)
{
return &session->local_address;
}
int AST_OPTIONAL_API_NAME(ast_websocket_is_secure)(struct ast_websocket *session)
{
return session->secure;
}
int AST_OPTIONAL_API_NAME(ast_websocket_set_nonblock)(struct ast_websocket *session)
{
ast_iostream_nonblock(session->stream);
ast_iostream_set_exclusive_input(session->stream, 0);
return 0;
}
int AST_OPTIONAL_API_NAME(ast_websocket_set_timeout)(struct ast_websocket *session, int timeout)
{
session->timeout = timeout;
return 0;
}
const char * AST_OPTIONAL_API_NAME(ast_websocket_session_id)(struct ast_websocket *session)
{
return session->session_id;
}
/* MAINTENANCE WARNING on ast_websocket_read()!
*
* We have to keep in mind during this function that the fact that session->fd seems ready
* (via poll) does not necessarily mean we have application data ready, because in the case
* of an SSL socket, there is some encryption data overhead that needs to be read from the
* TCP socket, so poll() may say there are bytes to be read, but whether it is just 1 byte
* or N bytes we do not know that, and we do not know how many of those bytes (if any) are
* for application data (for us) and not just for the SSL protocol consumption
*
* There used to be a couple of nasty bugs here that were fixed in last refactoring but I
* want to document them so the constraints are clear and we do not re-introduce them:
*
* - This function would incorrectly assume that fread() would necessarily return more than
* 1 byte of data, just because a websocket frame is always >= 2 bytes, but the thing
* is we're dealing with a TCP bitstream here, we could read just one byte and that's normal.
* The problem before was that if just one byte was read, the function bailed out and returned
* an error, effectively dropping the first byte of a websocket frame header!
*
* - Another subtle bug was that it would just read up to MAX_WS_HDR_SZ (14 bytes) via fread()
* then assume that executing poll() would tell you if there is more to read, but since
* we're dealing with a buffered stream (session->f is a FILE*), poll would say there is
* nothing else to read (in the real tcp socket session->fd) and we would get stuck here
* without processing the rest of the data in session->f internal buffers until another packet
* came on the network to unblock us!
*
* Note during the header parsing stage we try to read in small chunks just what we need, this
* is buffered data anyways, no expensive syscall required most of the time ...
*/
static inline int ws_safe_read(struct ast_websocket *session, char *buf, size_t len, enum ast_websocket_opcode *opcode)
{
ssize_t rlen;
int xlen = len;
char *rbuf = buf;
int sanity = 10;
ast_assert(len > 0);
if (!len) {
errno = EINVAL;
return -1;
}
ao2_lock(session);
if (!session->stream) {
ao2_unlock(session);
errno = ECONNABORTED;
return -1;
}
for (;;) {
rlen = ast_iostream_read(session->stream, rbuf, xlen);
if (rlen != xlen) {
if (rlen == 0) {
ast_log(LOG_WARNING, "Web socket closed abruptly\n");
*opcode = AST_WEBSOCKET_OPCODE_CLOSE;
session->closing = 1;
ao2_unlock(session);
return -1;
}
if (rlen < 0 && errno != EAGAIN) {
ast_log(LOG_ERROR, "Error reading from web socket: %s\n", strerror(errno));
*opcode = AST_WEBSOCKET_OPCODE_CLOSE;
session->closing = 1;
ao2_unlock(session);
return -1;
}
if (!--sanity) {
ast_log(LOG_WARNING, "Websocket seems unresponsive, disconnecting ...\n");
*opcode = AST_WEBSOCKET_OPCODE_CLOSE;
session->closing = 1;
ao2_unlock(session);
return -1;
}
}
if (rlen > 0) {
xlen = xlen - rlen;
rbuf = rbuf + rlen;
if (!xlen) {
break;
}
}
if (ast_iostream_wait_for_input(session->stream, 1000) < 0) {
ast_log(LOG_ERROR, "ast_iostream_wait_for_input returned err: %s\n", strerror(errno));
*opcode = AST_WEBSOCKET_OPCODE_CLOSE;
session->closing = 1;
ao2_unlock(session);
return -1;
}
}
ao2_unlock(session);
return 0;
}
int AST_OPTIONAL_API_NAME(ast_websocket_read)(struct ast_websocket *session, char **payload, uint64_t *payload_len, enum ast_websocket_opcode *opcode, int *fragmented)
{
int fin = 0;
int mask_present = 0;
char *mask = NULL, *new_payload = NULL;
size_t options_len = 0, frame_size = 0;
*payload = NULL;
*payload_len = 0;
*fragmented = 0;
if (ws_safe_read(session, &session->buf[0], MIN_WS_HDR_SZ, opcode)) {
return -1;
}
frame_size += MIN_WS_HDR_SZ;
/* ok, now we have the first 2 bytes, so we know some flags, opcode and payload length (or whether payload length extension will be required) */
*opcode = session->buf[0] & 0xf;
*payload_len = session->buf[1] & 0x7f;
if (*opcode == AST_WEBSOCKET_OPCODE_TEXT || *opcode == AST_WEBSOCKET_OPCODE_BINARY || *opcode == AST_WEBSOCKET_OPCODE_CONTINUATION ||
*opcode == AST_WEBSOCKET_OPCODE_PING || *opcode == AST_WEBSOCKET_OPCODE_PONG || *opcode == AST_WEBSOCKET_OPCODE_CLOSE) {
fin = (session->buf[0] >> 7) & 1;
mask_present = (session->buf[1] >> 7) & 1;
/* Based on the mask flag and payload length, determine how much more we need to read before start parsing the rest of the header */
options_len += mask_present ? 4 : 0;
options_len += (*payload_len == 126) ? 2 : (*payload_len == 127) ? 8 : 0;
if (options_len) {
/* read the rest of the header options */
if (ws_safe_read(session, &session->buf[frame_size], options_len, opcode)) {
return -1;
}
frame_size += options_len;
}
if (*payload_len == 126) {
/* Grab the 2-byte payload length */
*payload_len = ntohs(get_unaligned_uint16(&session->buf[2]));
mask = &session->buf[4];
} else if (*payload_len == 127) {
/* Grab the 8-byte payload length */
*payload_len = ntohll(get_unaligned_uint64(&session->buf[2]));
mask = &session->buf[10];
} else {
/* Just set the mask after the small 2-byte header */
mask = &session->buf[2];
}
/* Now read the rest of the payload */
*payload = &session->buf[frame_size]; /* payload will start here, at the end of the options, if any */
frame_size = frame_size + (*payload_len); /* final frame size is header + optional headers + payload data */
if (frame_size > MAXIMUM_FRAME_SIZE) {
ast_log(LOG_WARNING, "Cannot fit huge websocket frame of %zu bytes\n", frame_size);
/* The frame won't fit :-( */
ast_websocket_close(session, 1009);
return -1;
}
if (*payload_len) {
if (ws_safe_read(session, *payload, *payload_len, opcode)) {
return -1;
}
}
/* If a mask is present unmask the payload */
if (mask_present) {
unsigned int pos;
for (pos = 0; pos < *payload_len; pos++) {
(*payload)[pos] ^= mask[pos % 4];
}
}
/* Per the RFC for PING we need to send back an opcode with the application data as received */
if (*opcode == AST_WEBSOCKET_OPCODE_PING) {
if (ast_websocket_write(session, AST_WEBSOCKET_OPCODE_PONG, *payload, *payload_len)) {
ast_websocket_close(session, 1009);
}
*payload_len = 0;
return 0;
}
/* Stop PONG processing here */
if (*opcode == AST_WEBSOCKET_OPCODE_PONG) {
*payload_len = 0;
return 0;
}
/* Save the CLOSE status code which will be sent in our own CLOSE in the destructor */
if (*opcode == AST_WEBSOCKET_OPCODE_CLOSE) {
session->closing = 1;
if (*payload_len >= 2) {
session->close_status_code = ntohs(get_unaligned_uint16(*payload));
}
*payload_len = 0;
return 0;
}
/* Below this point we are handling TEXT, BINARY or CONTINUATION opcodes */
if (*payload_len) {
if (!(new_payload = ast_realloc(session->payload, (session->payload_len + *payload_len)))) {
ast_log(LOG_WARNING, "Failed allocation: %p, %zu, %"PRIu64"\n",
session->payload, session->payload_len, *payload_len);
*payload_len = 0;
ast_websocket_close(session, 1009);
return -1;
}
session->payload = new_payload;
memcpy((session->payload + session->payload_len), (*payload), (*payload_len));
session->payload_len += *payload_len;
} else if (!session->payload_len && session->payload) {
ast_free(session->payload);
session->payload = NULL;
}
if (!fin && session->reconstruct && (session->payload_len < session->reconstruct)) {
/* If this is not a final message we need to defer returning it until later */
if (*opcode != AST_WEBSOCKET_OPCODE_CONTINUATION) {
session->opcode = *opcode;
}
*opcode = AST_WEBSOCKET_OPCODE_CONTINUATION;
*payload_len = 0;
*payload = NULL;
} else {
if (*opcode == AST_WEBSOCKET_OPCODE_CONTINUATION) {
if (!fin) {
/* If this was not actually the final message tell the user it is fragmented so they can deal with it accordingly */
*fragmented = 1;
} else {
/* Final frame in multi-frame so push up the actual opcode */
*opcode = session->opcode;
}
}
*payload_len = session->payload_len;
*payload = session->payload;
session->payload_len = 0;
}
} else {
ast_log(LOG_WARNING, "WebSocket unknown opcode %u\n", *opcode);
/* We received an opcode that we don't understand, the RFC states that 1003 is for a type of data that can't be accepted... opcodes
* fit that, I think. */
ast_websocket_close(session, 1003);
}
return 0;
}
/*!
* \brief If the server has exactly one configured protocol, return it.
*/
static struct ast_websocket_protocol *one_protocol(
struct ast_websocket_server *server)
{
SCOPED_AO2LOCK(lock, server->protocols);
if (ao2_container_count(server->protocols) != 1) {
return NULL;
}
return ao2_callback(server->protocols, OBJ_NOLOCK, NULL, NULL);
}
static char *websocket_combine_key(const char *key, char *res, int res_size)
{
char *combined;
unsigned combined_length = strlen(key) + strlen(WEBSOCKET_GUID) + 1;
uint8_t sha[20];
combined = ast_alloca(combined_length);
snprintf(combined, combined_length, "%s%s", key, WEBSOCKET_GUID);
ast_sha1_hash_uint(sha, combined);
ast_base64encode(res, (const unsigned char*)sha, 20, res_size);
return res;
}
static void websocket_bad_request(struct ast_tcptls_session_instance *ser)
{
struct ast_str *http_header = ast_str_create(64);
if (!http_header) {
ast_http_request_close_on_completion(ser);
ast_http_error(ser, 500, "Server Error", "Out of memory");
return;
}
ast_str_set(&http_header, 0, "Sec-WebSocket-Version: 7, 8, 13\r\n");
ast_http_send(ser, AST_HTTP_UNKNOWN, 400, "Bad Request", http_header, NULL, 0, 0);
}
int AST_OPTIONAL_API_NAME(ast_websocket_uri_cb)(struct ast_tcptls_session_instance *ser, const struct ast_http_uri *urih, const char *uri, enum ast_http_method method, struct ast_variable *get_vars, struct ast_variable *headers)
{
struct ast_variable *v;
const char *upgrade = NULL, *key = NULL, *key1 = NULL, *key2 = NULL, *protos = NULL;
char *requested_protocols = NULL, *protocol = NULL;
int version = 0, flags = 1;
struct ast_websocket_protocol *protocol_handler = NULL;
struct ast_websocket *session;
struct ast_websocket_server *server;
SCOPED_MODULE_USE(ast_module_info->self);
/* Upgrade requests are only permitted on GET methods */
if (method != AST_HTTP_GET) {
ast_http_error(ser, 501, "Not Implemented", "Attempt to use unimplemented / unsupported method");
return 0;
}
server = urih->data;
/* Get the minimum headers required to satisfy our needs */
for (v = headers; v; v = v->next) {
if (!strcasecmp(v->name, "Upgrade")) {
upgrade = v->value;
} else if (!strcasecmp(v->name, "Sec-WebSocket-Key")) {
key = v->value;
} else if (!strcasecmp(v->name, "Sec-WebSocket-Key1")) {
key1 = v->value;
} else if (!strcasecmp(v->name, "Sec-WebSocket-Key2")) {
key2 = v->value;
} else if (!strcasecmp(v->name, "Sec-WebSocket-Protocol")) {
protos = v->value;
} else if (!strcasecmp(v->name, "Sec-WebSocket-Version")) {
if (sscanf(v->value, "%30d", &version) != 1) {
version = 0;
}
}
}
/* If this is not a websocket upgrade abort */
if (!upgrade || strcasecmp(upgrade, "websocket")) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - did not request WebSocket\n",
ast_sockaddr_stringify(&ser->remote_address));
ast_http_error(ser, 426, "Upgrade Required", NULL);
return 0;
} else if (ast_strlen_zero(protos)) {
/* If there's only a single protocol registered, and the
* client doesn't specify what protocol it's using, go ahead
* and accept the connection */
protocol_handler = one_protocol(server);
if (!protocol_handler) {
/* Multiple registered subprotocols; client must specify */
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - no protocols requested\n",
ast_sockaddr_stringify(&ser->remote_address));
websocket_bad_request(ser);
return 0;
}
} else if (key1 && key2) {
/* Specification defined in http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-76 and
* http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00 -- not currently supported*/
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - unsupported version '00/76' chosen\n",
ast_sockaddr_stringify(&ser->remote_address));
websocket_bad_request(ser);
return 0;
}
if (!protocol_handler && protos) {
requested_protocols = ast_strdupa(protos);
/* Iterate through the requested protocols trying to find one that we have a handler for */
while (!protocol_handler && (protocol = strsep(&requested_protocols, ","))) {
protocol_handler = ao2_find(server->protocols, ast_strip(protocol), OBJ_KEY);
}
}
/* If no protocol handler exists bump this back to the requester */
if (!protocol_handler) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - no protocols out of '%s' supported\n",
ast_sockaddr_stringify(&ser->remote_address), protos);
websocket_bad_request(ser);
return 0;
}
/* Determine how to respond depending on the version */
if (version == 7 || version == 8 || version == 13) {
char base64[64];
if (!key || strlen(key) + strlen(WEBSOCKET_GUID) + 1 > 8192) { /* no stack overflows please */
websocket_bad_request(ser);
ao2_ref(protocol_handler, -1);
return 0;
}
if (ast_http_body_discard(ser)) {
websocket_bad_request(ser);
ao2_ref(protocol_handler, -1);
return 0;
}
if (!(session = ao2_alloc(sizeof(*session) + AST_UUID_STR_LEN + 1, session_destroy_fn))) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted\n",
ast_sockaddr_stringify(&ser->remote_address));
websocket_bad_request(ser);
ao2_ref(protocol_handler, -1);
return 0;
}
session->timeout = AST_DEFAULT_WEBSOCKET_WRITE_TIMEOUT;
/* Generate the session id */
if (!ast_uuid_generate_str(session->session_id, sizeof(session->session_id))) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - failed to generate a session id\n",
ast_sockaddr_stringify(&ser->remote_address));
ast_http_error(ser, 500, "Internal Server Error", "Allocation failed");
ao2_ref(protocol_handler, -1);
return 0;
}
if (protocol_handler->session_attempted
&& protocol_handler->session_attempted(ser, get_vars, headers, session->session_id)) {
ast_debug(3, "WebSocket connection from '%s' rejected by protocol handler '%s'\n",
ast_sockaddr_stringify(&ser->remote_address), protocol_handler->name);
websocket_bad_request(ser);
ao2_ref(protocol_handler, -1);
return 0;
}
/* RFC 6455, Section 4.1:
*
* 6. If the response includes a |Sec-WebSocket-Protocol| header
* field and this header field indicates the use of a
* subprotocol that was not present in the client's handshake
* (the server has indicated a subprotocol not requested by
* the client), the client MUST _Fail the WebSocket
* Connection_.
*/
if (protocol) {
ast_iostream_printf(ser->stream,
"HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: %s\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"Sec-WebSocket-Protocol: %s\r\n\r\n",
upgrade,
websocket_combine_key(key, base64, sizeof(base64)),
protocol);
} else {
ast_iostream_printf(ser->stream,
"HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: %s\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: %s\r\n\r\n",
upgrade,
websocket_combine_key(key, base64, sizeof(base64)));
}
} else {
/* Specification defined in http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-75 or completely unknown */
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - unsupported version '%d' chosen\n",
ast_sockaddr_stringify(&ser->remote_address), version ? version : 75);
websocket_bad_request(ser);
ao2_ref(protocol_handler, -1);
return 0;
}
/* Enable keepalive on all sessions so the underlying user does not have to */
if (setsockopt(ast_iostream_get_fd(ser->stream), SOL_SOCKET, SO_KEEPALIVE, &flags, sizeof(flags))) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - failed to enable keepalive\n",
ast_sockaddr_stringify(&ser->remote_address));
websocket_bad_request(ser);
ao2_ref(session, -1);
ao2_ref(protocol_handler, -1);
return 0;
}
/* Get our local address for the connected socket */
if (ast_getsockname(ast_iostream_get_fd(ser->stream), &session->local_address)) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - failed to get local address\n",
ast_sockaddr_stringify(&ser->remote_address));
websocket_bad_request(ser);
ao2_ref(session, -1);
ao2_ref(protocol_handler, -1);
return 0;
}
ast_verb(2, "WebSocket connection from '%s' for protocol '%s' accepted using version '%d'\n", ast_sockaddr_stringify(&ser->remote_address), protocol ? : "", version);
/* Populate the session with all the needed details */
session->stream = ser->stream;
ast_sockaddr_copy(&session->remote_address, &ser->remote_address);
session->opcode = -1;
session->reconstruct = DEFAULT_RECONSTRUCTION_CEILING;
session->secure = ast_iostream_get_ssl(ser->stream) ? 1 : 0;
/* Give up ownership of the socket and pass it to the protocol handler */
ast_iostream_set_exclusive_input(session->stream, 0);
protocol_handler->session_established(session, get_vars, headers);
ao2_ref(protocol_handler, -1);
/*
* By dropping the stream from the session the connection
* won't get closed when the HTTP server cleans up because we
* passed the connection to the protocol handler.
*/
ser->stream = NULL;
return 0;
}
static struct ast_http_uri websocketuri = {
.callback = AST_OPTIONAL_API_NAME(ast_websocket_uri_cb),
.description = "Asterisk HTTP WebSocket",
.uri = "ws",
.has_subtree = 0,
.data = NULL,
.key = __FILE__,
};
/*! \brief Simple echo implementation which echoes received text and binary frames */
static void websocket_echo_callback(struct ast_websocket *session, struct ast_variable *parameters, struct ast_variable *headers)
{
int res;
ast_debug(1, "Entering WebSocket echo loop\n");
if (ast_fd_set_flags(ast_websocket_fd(session), O_NONBLOCK)) {
goto end;
}
while ((res = ast_websocket_wait_for_input(session, -1)) > 0) {
char *payload;
uint64_t payload_len;
enum ast_websocket_opcode opcode;
int fragmented;
if (ast_websocket_read(session, &payload, &payload_len, &opcode, &fragmented)) {
/* We err on the side of caution and terminate the session if any error occurs */
ast_log(LOG_WARNING, "Read failure during WebSocket echo loop\n");
break;
}
if (opcode == AST_WEBSOCKET_OPCODE_TEXT || opcode == AST_WEBSOCKET_OPCODE_BINARY) {
ast_websocket_write(session, opcode, payload, payload_len);
} else if (opcode == AST_WEBSOCKET_OPCODE_CLOSE) {
break;
} else {
ast_debug(1, "Ignored WebSocket opcode %u\n", opcode);
}
}
end:
ast_debug(1, "Exiting WebSocket echo loop\n");
ast_websocket_unref(session);
}
static int websocket_add_protocol_internal(const char *name, ast_websocket_callback callback)
{
struct ast_websocket_server *ws_server = websocketuri.data;
if (!ws_server) {
return -1;
}
return ast_websocket_server_add_protocol(ws_server, name, callback);
}
int AST_OPTIONAL_API_NAME(ast_websocket_add_protocol)(const char *name, ast_websocket_callback callback)
{
return websocket_add_protocol_internal(name, callback);
}
int AST_OPTIONAL_API_NAME(ast_websocket_add_protocol2)(struct ast_websocket_protocol *protocol)
{
struct ast_websocket_server *ws_server = websocketuri.data;
if (!ws_server) {
return -1;
}
if (ast_websocket_server_add_protocol2(ws_server, protocol)) {
return -1;
}
return 0;
}
static int websocket_remove_protocol_internal(const char *name, ast_websocket_callback callback)
{
struct ast_websocket_server *ws_server = websocketuri.data;
if (!ws_server) {
return -1;
}
return ast_websocket_server_remove_protocol(ws_server, name, callback);
}
int AST_OPTIONAL_API_NAME(ast_websocket_remove_protocol)(const char *name, ast_websocket_callback callback)
{
return websocket_remove_protocol_internal(name, callback);
}
/*! \brief Parse the given uri into a path and remote address.
*
* Expected uri form:
* \verbatim [ws[s]]://<host>[:port][/<path>] \endverbatim
*
* The returned host will contain the address and optional port while
* path will contain everything after the address/port if included.
*/
static int websocket_client_parse_uri(const char *uri, char **host, struct ast_str **path)
{
struct ast_uri *parsed_uri = ast_uri_parse_websocket(uri);
if (!parsed_uri) {
return -1;
}
*host = ast_uri_make_host_with_port(parsed_uri);
if (ast_uri_path(parsed_uri) || ast_uri_query(parsed_uri)) {
*path = ast_str_create(64);
if (!*path) {
ao2_ref(parsed_uri, -1);
return -1;
}
if (ast_uri_path(parsed_uri)) {
ast_str_set(path, 0, "%s", ast_uri_path(parsed_uri));
}
if (ast_uri_query(parsed_uri)) {
ast_str_append(path, 0, "?%s", ast_uri_query(parsed_uri));
}
}
ao2_ref(parsed_uri, -1);
return 0;
}
static void websocket_client_args_destroy(void *obj)
{
struct ast_tcptls_session_args *args = obj;
if (args->tls_cfg) {
ast_free(args->tls_cfg->certfile);
ast_free(args->tls_cfg->pvtfile);
ast_free(args->tls_cfg->cipher);
ast_free(args->tls_cfg->cafile);
ast_free(args->tls_cfg->capath);
ast_ssl_teardown(args->tls_cfg);
}
ast_free(args->tls_cfg);
}
static struct ast_tcptls_session_args *websocket_client_args_create(
const char *host, struct ast_tls_config *tls_cfg,
enum ast_websocket_result *result)
{
struct ast_sockaddr *addr;
struct ast_tcptls_session_args *args = ao2_alloc(
sizeof(*args), websocket_client_args_destroy);
if (!args) {
*result = WS_ALLOCATE_ERROR;
return NULL;
}
args->accept_fd = -1;
args->tls_cfg = tls_cfg;
args->name = "websocket client";
if (!ast_sockaddr_resolve(&addr, host, 0, 0)) {
ast_log(LOG_ERROR, "Unable to resolve address %s\n",
host);
ao2_ref(args, -1);
*result = WS_URI_RESOLVE_ERROR;
return NULL;
}
ast_sockaddr_copy(&args->remote_address, addr);
ast_free(addr);
return args;
}
static char *websocket_client_create_key(void)
{
static int encoded_size = CLIENT_KEY_SIZE * 2 * sizeof(char) + 1;
/* key is randomly selected 16-byte base64 encoded value */
unsigned char key[CLIENT_KEY_SIZE + sizeof(long) - 1];
char *encoded = ast_malloc(encoded_size);
long i = 0;
if (!encoded) {
ast_log(LOG_ERROR, "Unable to allocate client websocket key\n");
return NULL;
}
while (i < CLIENT_KEY_SIZE) {
long num = ast_random();
memcpy(key + i, &num, sizeof(long));
i += sizeof(long);
}
ast_base64encode(encoded, key, CLIENT_KEY_SIZE, encoded_size);
return encoded;
}
struct websocket_client {
/*! host portion of client uri */
char *host;
/*! path for logical websocket connection */
struct ast_str *resource_name;
/*! unique key used during server handshaking */
char *key;
/*! container for registered protocols */
char *protocols;
/*! the protocol accepted by the server */
char *accept_protocol;
/*! websocket protocol version */
int version;
/*! tcptls connection arguments */
struct ast_tcptls_session_args *args;
/*! tcptls connection instance */
struct ast_tcptls_session_instance *ser;
};
static void websocket_client_destroy(void *obj)
{
struct websocket_client *client = obj;
ao2_cleanup(client->ser);
ao2_cleanup(client->args);
ast_free(client->accept_protocol);
ast_free(client->protocols);
ast_free(client->key);
ast_free(client->resource_name);
ast_free(client->host);
}
static struct ast_websocket * websocket_client_create(
struct ast_websocket_client_options *options, enum ast_websocket_result *result)
{
struct ast_websocket *ws = ao2_alloc(sizeof(*ws), session_destroy_fn);
if (!ws) {
ast_log(LOG_ERROR, "Unable to allocate websocket\n");
*result = WS_ALLOCATE_ERROR;
return NULL;
}
if (!(ws->client = ao2_alloc(
sizeof(*ws->client), websocket_client_destroy))) {
ast_log(LOG_ERROR, "Unable to allocate websocket client\n");
*result = WS_ALLOCATE_ERROR;
return NULL;
}
if (!(ws->client->key = websocket_client_create_key())) {
ao2_ref(ws, -1);
*result = WS_KEY_ERROR;
return NULL;
}
if (websocket_client_parse_uri(
options->uri, &ws->client->host, &ws->client->resource_name)) {
ao2_ref(ws, -1);
*result = WS_URI_PARSE_ERROR;
return NULL;
}
if (!(ws->client->args = websocket_client_args_create(
ws->client->host, options->tls_cfg, result))) {
ao2_ref(ws, -1);
return NULL;
}
ws->client->protocols = ast_strdup(options->protocols);
ws->client->version = 13;
ws->opcode = -1;
ws->reconstruct = DEFAULT_RECONSTRUCTION_CEILING;
return ws;
}
const char * AST_OPTIONAL_API_NAME(
ast_websocket_client_accept_protocol)(struct ast_websocket *ws)
{
return ws->client->accept_protocol;
}
static enum ast_websocket_result websocket_client_handle_response_code(
struct websocket_client *client, int response_code)
{
if (response_code <= 0) {
return WS_INVALID_RESPONSE;
}
switch (response_code) {
case 101:
return 0;
case 400:
ast_log(LOG_ERROR, "Received response 400 - Bad Request "
"- from %s\n", client->host);
return WS_BAD_REQUEST;
case 404:
ast_log(LOG_ERROR, "Received response 404 - Request URL not "
"found - from %s\n", client->host);
return WS_URL_NOT_FOUND;
}
ast_log(LOG_ERROR, "Invalid HTTP response code %d from %s\n",
response_code, client->host);
return WS_INVALID_RESPONSE;
}
static enum ast_websocket_result websocket_client_handshake_get_response(
struct websocket_client *client)
{
enum ast_websocket_result res;
char buf[4096];
char base64[64];
int has_upgrade = 0;
int has_connection = 0;
int has_accept = 0;
int has_protocol = 0;
while (ast_iostream_gets(client->ser->stream, buf, sizeof(buf)) <= 0) {
if (errno == EINTR || errno == EAGAIN) {
continue;
}
ast_log(LOG_ERROR, "Unable to retrieve HTTP status line.");
return WS_BAD_STATUS;
}
if ((res = websocket_client_handle_response_code(client,
ast_http_response_status_line(
buf, "HTTP/1.1", 101))) != WS_OK) {
return res;
}
/* Ignoring line folding - assuming header field values are contained
within a single line */
while (1) {
ssize_t len = ast_iostream_gets(client->ser->stream, buf, sizeof(buf));
char *name, *value;
int parsed;
if (len <= 0) {
if (errno == EINTR || errno == EAGAIN) {
continue;
}
break;
}
parsed = ast_http_header_parse(buf, &name, &value);
if (parsed < 0) {
break;
}
if (parsed > 0) {
continue;
}
if (!has_upgrade &&
(has_upgrade = ast_http_header_match(
name, "upgrade", value, "websocket")) < 0) {
return WS_HEADER_MISMATCH;
} else if (!has_connection &&
(has_connection = ast_http_header_match(
name, "connection", value, "upgrade")) < 0) {
return WS_HEADER_MISMATCH;
} else if (!has_accept &&
(has_accept = ast_http_header_match(
name, "sec-websocket-accept", value,
websocket_combine_key(
client->key, base64, sizeof(base64)))) < 0) {
return WS_HEADER_MISMATCH;
} else if (!has_protocol &&
(has_protocol = ast_http_header_match_in(
name, "sec-websocket-protocol", value, client->protocols))) {
if (has_protocol < 0) {
return WS_HEADER_MISMATCH;
}
client->accept_protocol = ast_strdup(value);
} else if (!strcasecmp(name, "sec-websocket-extensions")) {
ast_log(LOG_ERROR, "Extensions received, but not "
"supported by client\n");
return WS_NOT_SUPPORTED;
}
}
return has_upgrade && has_connection && has_accept ?
WS_OK : WS_HEADER_MISSING;
}
static enum ast_websocket_result websocket_client_handshake(
struct websocket_client *client)
{
char protocols[100] = "";
if (!ast_strlen_zero(client->protocols)) {
sprintf(protocols, "Sec-WebSocket-Protocol: %s\r\n",
client->protocols);
}
if (ast_iostream_printf(client->ser->stream,
"GET /%s HTTP/1.1\r\n"
"Sec-WebSocket-Version: %d\r\n"
"Upgrade: websocket\r\n"
"Connection: Upgrade\r\n"
"Host: %s\r\n"
"Sec-WebSocket-Key: %s\r\n"
"%s\r\n",
client->resource_name ? ast_str_buffer(client->resource_name) : "",
client->version,
client->host,
client->key,
protocols) < 0) {
ast_log(LOG_ERROR, "Failed to send handshake.\n");
return WS_WRITE_ERROR;
}
/* wait for a response before doing anything else */
return websocket_client_handshake_get_response(client);
}
static enum ast_websocket_result websocket_client_connect(struct ast_websocket *ws, int timeout)
{
enum ast_websocket_result res;
/* create and connect the client - note client_start
releases the session instance on failure */
if (!(ws->client->ser = ast_tcptls_client_start_timeout(
ast_tcptls_client_create(ws->client->args), timeout))) {
return WS_CLIENT_START_ERROR;
}
if ((res = websocket_client_handshake(ws->client)) != WS_OK) {
ao2_ref(ws->client->ser, -1);
ws->client->ser = NULL;
return res;
}
ws->stream = ws->client->ser->stream;
ws->secure = ast_iostream_get_ssl(ws->stream) ? 1 : 0;
ws->client->ser->stream = NULL;
ast_sockaddr_copy(&ws->remote_address, &ws->client->ser->remote_address);
return WS_OK;
}
struct ast_websocket *AST_OPTIONAL_API_NAME(ast_websocket_client_create)
(const char *uri, const char *protocols, struct ast_tls_config *tls_cfg,
enum ast_websocket_result *result)
{
struct ast_websocket_client_options options = {
.uri = uri,
.protocols = protocols,
.timeout = -1,
.tls_cfg = tls_cfg,
};
return ast_websocket_client_create_with_options(&options, result);
}
struct ast_websocket *AST_OPTIONAL_API_NAME(ast_websocket_client_create_with_options)
(struct ast_websocket_client_options *options, enum ast_websocket_result *result)
{
struct ast_websocket *ws = websocket_client_create(options, result);
if (!ws) {
return NULL;
}
if ((*result = websocket_client_connect(ws, options->timeout)) != WS_OK) {
ao2_ref(ws, -1);
return NULL;
}
return ws;
}
int AST_OPTIONAL_API_NAME(ast_websocket_read_string)
(struct ast_websocket *ws, char **buf)
{
char *payload;
uint64_t payload_len;
enum ast_websocket_opcode opcode;
int fragmented = 1;
while (fragmented) {
if (ast_websocket_read(ws, &payload, &payload_len,
&opcode, &fragmented)) {
ast_log(LOG_ERROR, "Client WebSocket string read - "
"error reading string data\n");
return -1;
}
if (opcode == AST_WEBSOCKET_OPCODE_PING) {
/* Try read again, we have sent pong already */
fragmented = 1;
continue;
}
if (opcode == AST_WEBSOCKET_OPCODE_CONTINUATION) {
continue;
}
if (opcode == AST_WEBSOCKET_OPCODE_CLOSE) {
return -1;
}
if (opcode != AST_WEBSOCKET_OPCODE_TEXT) {
ast_log(LOG_ERROR, "Client WebSocket string read - "
"non string data received\n");
return -1;
}
}
if (!(*buf = ast_strndup(payload, payload_len))) {
return -1;
}
return payload_len + 1;
}
int AST_OPTIONAL_API_NAME(ast_websocket_write_string)
(struct ast_websocket *ws, const char *buf)
{
uint64_t len = strlen(buf);
ast_debug(3, "Writing websocket string of length %" PRIu64 "\n", len);
/* We do not pass strlen(buf) to ast_websocket_write() directly because the
* size_t returned by strlen() may not require the same storage size
* as the uint64_t that ast_websocket_write() uses. This normally
* would not cause a problem, but since ast_websocket_write() uses
* the optional API, this function call goes through a series of macros
* that may cause a 32-bit to 64-bit conversion to go awry.
*/
return ast_websocket_write(ws, AST_WEBSOCKET_OPCODE_TEXT,
(char *)buf, len);
}
static int load_module(void)
{
websocketuri.data = websocket_server_internal_create();
if (!websocketuri.data) {
return AST_MODULE_LOAD_DECLINE;
}
ast_http_uri_link(&websocketuri);
websocket_add_protocol_internal("echo", websocket_echo_callback);
return 0;
}
static int unload_module(void)
{
websocket_remove_protocol_internal("echo", websocket_echo_callback);
ast_http_uri_unlink(&websocketuri);
ao2_ref(websocketuri.data, -1);
websocketuri.data = NULL;
return 0;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "HTTP WebSocket Support",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_CHANNEL_DEPEND,
.requires = "http",
);