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Add res_http_websocket module which implements the WebSocket protocol according to RFC 6455.

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Review: https://reviewboard.asterisk.org/r/1952/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@368359 65c4cc65-6c06-0410-ace0-fbb531ad65f3
certified/11.2
Joshua Colp 13 years ago
parent 91a20ee2f9
commit 380c7c5c39
5 changed files with 973 additions and 0 deletions
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280
include/asterisk/http_websocket.h
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/*
* 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.
*/
#ifndef _ASTERISK_HTTP_WEBSOCKET_H
#define _ASTERISK_HTTP_WEBSOCKET_H
#include "asterisk/module.h"
/*!
* \file http_websocket.h
* \brief Support for WebSocket connections within the Asterisk HTTP server.
*
* \author Joshua Colp <jcolp@digium.com>
*
*/
/*! \brief WebSocket operation codes */
enum ast_websocket_opcode {
AST_WEBSOCKET_OPCODE_TEXT = 0x1, /*!< Text frame */
AST_WEBSOCKET_OPCODE_BINARY = 0x2, /*!< Binary frame */
AST_WEBSOCKET_OPCODE_PING = 0x9, /*!< Request that the other side respond with a pong */
AST_WEBSOCKET_OPCODE_PONG = 0xA, /*!< Response to a ping */
AST_WEBSOCKET_OPCODE_CLOSE = 0x8, /*!< Connection is being closed */
AST_WEBSOCKET_OPCODE_CONTINUATION = 0x0, /*!< Continuation of a previous frame */
};
/*!
* \brief Opaque structure for WebSocket sessions
*/
struct ast_websocket;
/*!
* \brief Callback for when a new connection for a sub-protocol is established
*
* \param session A WebSocket session structure
* \param parameters Parameters extracted from the request URI
* \param headers Headers included in the request
*
* \note Once called the ownership of the session is transferred to the sub-protocol handler. It
* is responsible for closing and cleaning up.
*
*/
typedef void (*ast_websocket_callback)(struct ast_websocket *session, struct ast_variable *parameters, struct ast_variable *headers);
/*!
* \brief Add a sub-protocol handler to the server
*
* \param name Name of the sub-protocol to register
* \param callback Callback called when a new connection requesting the sub-protocol is established
*
* \retval 0 success
* \retval -1 if sub-protocol handler could not be registered
*/
int ast_websocket_add_protocol(const char *name, ast_websocket_callback callback);
/*!
* \brief Remove a sub-protocol handler from the server
*
* \param name Name of the sub-protocol to unregister
* \param callback Callback that was previously registered with the sub-protocol
*
* \retval 0 success
* \retval -1 if sub-protocol was not found or if callback did not match
*/
int ast_websocket_remove_protocol(const char *name, ast_websocket_callback callback);
/*!
* \brief Read a WebSocket frame and handle it
*
* \param session Pointer to the WebSocket session
* \param payload Pointer to a char* which will be populated with a pointer to the payload if present
* \param payload_len Pointer to a uint64_t which will be populated with the length of the payload if present
* \param opcode Pointer to an enum which will be populated with the opcode of the frame
* \param fragmented Pointer to an int which is set to 1 if payload is fragmented and 0 if not
*
* \retval -1 on error
* \retval 0 on success
*
* \note Once an AST_WEBSOCKET_OPCODE_CLOSE opcode is received the socket will be closed
*/
int ast_websocket_read(struct ast_websocket *session, char **payload, uint64_t *payload_len, enum ast_websocket_opcode *opcode, int *fragmented);
/*!
* \brief Construct and transmit a WebSocket frame
*
* \param session Pointer to the WebSocket session
* \param opcode WebSocket operation code to place in the frame
* \param payload Optional pointer to a payload to add to the frame
* \param actual_length Length of the payload (0 if no payload)
*
* \retval 0 if successfully written
* \retval -1 if error occurred
*/
int ast_websocket_write(struct ast_websocket *session, enum ast_websocket_opcode opcode, char *payload, uint64_t actual_length);
/*!
* \brief Close a WebSocket session by sending a message with the CLOSE opcode and an optional code
*
* \param session Pointer to the WebSocket session
* \param reason Reason code for closing the session as defined in the RFC
*
* \retval 0 if successfully written
* \retval -1 if error occurred
*/
int ast_websocket_close(struct ast_websocket *session, uint16_t reason);
/*!
* \brief Enable multi-frame reconstruction up to a certain number of bytes
*
* \param session Pointer to the WebSocket session
* \param bytes If a reconstructed payload exceeds the specified number of bytes the payload will be returned
* and upon reception of the next multi-frame a new reconstructed payload will begin.
*/
void ast_websocket_reconstruct_enable(struct ast_websocket *session, size_t bytes);
/*!
* \brief Disable multi-frame reconstruction
*
* \param session Pointer to the WebSocket session
*
* \note If reconstruction is disabled each message that is part of a multi-frame message will be sent up to
* the user when ast_websocket_read is called.
*/
void ast_websocket_reconstruct_disable(struct ast_websocket *session);
/*!
* \brief Increase the reference count for a WebSocket session
*
* \param session Pointer to the WebSocket session
*/
void ast_websocket_ref(struct ast_websocket *session);
/*!
* \brief Decrease the reference count for a WebSocket session
*
* \param session Pointer to the WebSocket session
*/
void ast_websocket_unref(struct ast_websocket *session);
/*!
* \brief Get the file descriptor for a WebSocket session.
*
* \retval file descriptor
*
* \note You must *not* directly read from or write to this file descriptor. It should only be used for polling.
*/
int ast_websocket_fd(struct ast_websocket *session);
/*!
* \brief Get the remote address for a WebSocket connected session.
*
* \retval ast_sockaddr Remote address
*/
struct ast_sockaddr *ast_websocket_remote_address(struct ast_websocket *session);
/*!
* \brief Get whether the WebSocket session is using a secure transport or not.
*
* \retval 0 if unsecure
* \retval 1 if secure
*/
int ast_websocket_is_secure(struct ast_websocket *session);
#endif /* _ASTERISK_HTTP_WEBSOCKET_H */
/*
* 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.
*/
#ifndef _ASTERISK_HTTP_WEBSOCKET_H
#define _ASTERISK_HTTP_WEBSOCKET_H
#include "asterisk/module.h"
/*!
* \file http_websocket.h
* \brief Support for WebSocket connections within the Asterisk HTTP server.
*
* \author Joshua Colp <jcolp@digium.com>
*
*/
/*! \brief WebSocket operation codes */
enum ast_websocket_opcode {
AST_WEBSOCKET_OPCODE_TEXT = 0x1, /*!< Text frame */
AST_WEBSOCKET_OPCODE_BINARY = 0x2, /*!< Binary frame */
AST_WEBSOCKET_OPCODE_PING = 0x9, /*!< Request that the other side respond with a pong */
AST_WEBSOCKET_OPCODE_PONG = 0xA, /*!< Response to a ping */
AST_WEBSOCKET_OPCODE_CLOSE = 0x8, /*!< Connection is being closed */
AST_WEBSOCKET_OPCODE_CONTINUATION = 0x0, /*!< Continuation of a previous frame */
};
/*!
* \brief Callback for when a new connection for a sub-protocol is established
*
* \param f Pointer to the file instance for the session
* \param fd File descriptor for the session
* \param remote_address The address of the remote party
*
* \note Once called the ownership of the session is transferred to the sub-protocol handler. It
* is responsible for closing and cleaning up.
*
*/
typedef void (*ast_websocket_callback)(FILE *f, int fd, struct ast_sockaddr *remote_address);
/*!
* \brief Add a sub-protocol handler to the server
*
* \param name Name of the sub-protocol to register
* \param callback Callback called when a new connection requesting the sub-protocol is established
*
* \retval 0 success
* \retval -1 if sub-protocol handler could not be registered
*/
int ast_websocket_add_protocol(char *name, ast_websocket_callback callback);
/*!
* \brief Remove a sub-protocol handler from the server
*
* \param name Name of the sub-protocol to unregister
* \param callback Callback that was previously registered with the sub-protocol
*
* \retval 0 success
* \retval -1 if sub-protocol was not found or if callback did not match
*/
int ast_websocket_remove_protocol(char *name, ast_websocket_callback callback);
/*!
* \brief Read a WebSocket frame and handle it
*
* \param f Pointer to the file stream, used to respond to certain frames
* \param buf Pointer to the buffer containing the frame
* \param buflen Size of the buffer
* \param payload_len Pointer to a uint64_t which will be populated with the length of the payload if present
* \param opcode Pointer to an int which will be populated with the opcode of the frame
*
* \retval NULL if no payload is present
* \retval non-NULL if payload is present, returned pointer points to beginning of payload
*/
char *ast_websocket_read(FILE *f, char *buf, size_t buflen, uint64_t *payload_len, int *opcode);
/*!
* \brief Construct and transmit a WebSocket frame
*
* \param f Pointer to the file stream which the frame will be sent on
* \param opcode WebSocket operation code to place in the frame
* \param payload Optional pointer to a payload to add to the frame
* \param actual_length Length of the payload (0 if no payload)
*/
void ast_websocket_write(FILE *f, int op_code, char *payload, uint64_t actual_length);
#endif /* _ASTERISK_HTTP_WEBSOCKET_H */

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include/asterisk/utils.h
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@ -219,6 +219,8 @@ struct hostent *ast_gethostbyname(const char *host, struct ast_hostent *hp);
void ast_md5_hash(char *output, const char *input);
/*! \brief Produces SHA1 hash based on input string */
void ast_sha1_hash(char *output, const char *input);
/*! \brief Produces SHA1 hash based on input string, stored in uint8_t array */
void ast_sha1_hash_uint(uint8_t *digest, const char *input);
int ast_base64encode_full(char *dst, const unsigned char *src, int srclen, int max, int linebreaks);

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main/utils.c
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@ -270,6 +270,18 @@ void ast_sha1_hash(char *output, const char *input)
ptr += sprintf(ptr, "%2.2x", Message_Digest[x]);
}
/*! \brief Produce a 20 byte SHA1 hash of value. */
void ast_sha1_hash_uint(uint8_t *digest, const char *input)
{
struct SHA1Context sha;
SHA1Reset(&sha);
SHA1Input(&sha, (const unsigned char *) input, strlen(input));
SHA1Result(&sha, digest);
}
/*! \brief decode BASE64 encoded text */
int ast_base64decode(unsigned char *dst, const char *src, int max)
{

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res/res_http_websocket.c
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/*
* 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>extended</support_level>
***/
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#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/http_websocket.h"
/*! \brief GUID used to compute the accept key, defined in the specifications */
#define WEBSOCKET_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
/*! \brief Number of buckets for registered protocols */
#define MAX_PROTOCOL_BUCKETS 7
/*! \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 16384
/*! \brief Maximum reconstruction size for multi-frame payload reconstruction. */
#define MAXIMUM_RECONSTRUCTION_CEILING 16384
/*! \brief Structure definition for session */
struct ast_websocket {
FILE *f; /*!< Pointer to the file instance used for writing and reading */
int fd; /*!< File descriptor for the session, only used for polling */
struct ast_sockaddr address; /*!< Address of the remote client */
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 */
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 */
};
/*! \brief Structure definition for protocols */
struct websocket_protocol {
char *name; /*!< Name of the protocol */
ast_websocket_callback callback; /*!< Callback called when a new session is established */
};
/*! \brief Container for registered protocols */
static struct ao2_container *protocols;
/*! \brief Hashing function for protocols */
static int protocol_hash_fn(const void *obj, const int flags)
{
const struct 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 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 websocket_protocol *protocol = obj;
ast_free(protocol->name);
}
/*! \brief Destructor function for sessions */
static void session_destroy_fn(void *obj)
{
struct ast_websocket *session = obj;
if (session->f) {
fclose(session->f);
ast_verb(2, "WebSocket connection from '%s' closed\n", ast_sockaddr_stringify(&session->address));
}
ast_free(session->payload);
}
int ast_websocket_add_protocol(const char *name, ast_websocket_callback callback)
{
struct websocket_protocol *protocol;
ao2_lock(protocols);
/* Ensure a second protocol handler is not registered for the same protocol */
if ((protocol = ao2_find(protocols, name, OBJ_KEY | OBJ_NOLOCK))) {
ao2_ref(protocol, -1);
ao2_unlock(protocols);
return -1;
}
if (!(protocol = ao2_alloc(sizeof(*protocol), protocol_destroy_fn))) {
ao2_unlock(protocols);
return -1;
}
if (!(protocol->name = ast_strdup(name))) {
ao2_ref(protocol, -1);
ao2_unlock(protocols);
return -1;
}
protocol->callback = callback;
ao2_link_flags(protocols, protocol, OBJ_NOLOCK);
ao2_unlock(protocols);
ao2_ref(protocol, -1);
ast_verb(2, "WebSocket registered sub-protocol '%s'\n", name);
return 0;
}
int ast_websocket_remove_protocol(const char *name, ast_websocket_callback callback)
{
struct websocket_protocol *protocol;
if (!(protocol = ao2_find(protocols, name, OBJ_KEY))) {
return -1;
}
if (protocol->callback != callback) {
ao2_ref(protocol, -1);
return -1;
}
ao2_unlink(protocols, protocol);
ao2_ref(protocol, -1);
ast_verb(2, "WebSocket unregistered sub-protocol '%s'\n", name);
return 0;
}
/*! \brief Close function for websocket session */
int ast_websocket_close(struct ast_websocket *session, uint16_t reason)
{
char frame[4] = { 0, }; /* The header is 2 bytes and the reason code takes up another 2 bytes */
frame[0] = AST_WEBSOCKET_OPCODE_CLOSE | 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[2], htons(reason ? reason : 1000));
session->closing = 1;
return (fwrite(frame, 1, 4, session->f) == 4) ? 0 : -1;
}
/*! \brief Write function for websocket traffic */
int ast_websocket_write(struct ast_websocket *session, enum ast_websocket_opcode opcode, char *payload, uint64_t actual_length)
{
size_t header_size = 2; /* The minimum size of a websocket frame is 2 bytes */
char *frame;
uint64_t length = 0;
if (actual_length < 126) {
length = actual_length;
} else if (actual_length < (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;
}
frame = alloca(header_size);
memset(frame, 0, sizeof(*frame));
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(actual_length));
} else if (length == 127) {
put_unaligned_uint64(&frame[2], htonl(actual_length));
}
if (fwrite(frame, 1, header_size, session->f) != header_size) {
return -1;
}
if (fwrite(payload, 1, actual_length, session->f) != actual_length) {
return -1;
}
return 0;
}
void ast_websocket_reconstruct_enable(struct ast_websocket *session, size_t bytes)
{
session->reconstruct = MIN(bytes, MAXIMUM_RECONSTRUCTION_CEILING);
}
void ast_websocket_reconstruct_disable(struct ast_websocket *session)
{
session->reconstruct = 0;
}
void ast_websocket_ref(struct ast_websocket *session)
{
ao2_ref(session, +1);
}
void ast_websocket_unref(struct ast_websocket *session)
{
ao2_ref(session, -1);
}
int ast_websocket_fd(struct ast_websocket *session)
{
return session->closing ? -1 : session->fd;
}
struct ast_sockaddr *ast_websocket_remote_address(struct ast_websocket *session)
{
return &session->address;
}
int ast_websocket_is_secure(struct ast_websocket *session)
{
return session->secure;
}
int ast_websocket_read(struct ast_websocket *session, char **payload, uint64_t *payload_len, enum ast_websocket_opcode *opcode, int *fragmented)
{
char buf[MAXIMUM_FRAME_SIZE] = "";
size_t frame_size, expected = 2;
*payload = NULL;
*payload_len = 0;
*fragmented = 0;
/* We try to read in 14 bytes, which is the largest possible WebSocket header */
if ((frame_size = fread(&buf, 1, 14, session->f)) < 1) {
return -1;
}
/* The minimum size for a WebSocket frame is 2 bytes */
if (frame_size < expected) {
return -1;
}
*opcode = buf[0] & 0xf;
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) {
int fin = (buf[0] >> 7) & 1;
int mask_present = (buf[1] >> 7) & 1;
char *mask = NULL, *new_payload;
size_t remaining;
if (mask_present) {
/* The mask should take up 4 bytes */
expected += 4;
if (frame_size < expected) {
/* Per the RFC 1009 means we received a message that was too large for us to process */
ast_websocket_close(session, 1009);
return 0;
}
}
/* Assume no extended length and no masking at the beginning */
*payload_len = buf[1] & 0x7f;
*payload = &buf[2];
/* Determine if extended length is being used */
if (*payload_len == 126) {
/* Use the next 2 bytes to get a uint16_t */
expected += 2;
*payload += 2;
if (frame_size < expected) {
ast_websocket_close(session, 1009);
return 0;
}
*payload_len = ntohs(get_unaligned_uint16(&buf[2]));
} else if (*payload_len == 127) {
/* Use the next 8 bytes to get a uint64_t */
expected += 8;
*payload += 8;
if (frame_size < expected) {
ast_websocket_close(session, 1009);
return 0;
}
*payload_len = ntohl(get_unaligned_uint64(&buf[2]));
}
/* If masking is present the payload currently points to the mask, so move it over 4 bytes to the actual payload */
if (mask_present) {
mask = *payload;
*payload += 4;
}
/* Determine how much payload we need to read in as we may have already read some in */
remaining = *payload_len - (frame_size - expected);
/* If how much payload they want us to read in exceeds what we are capable of close the session, things
* will fail no matter what most likely */
if (remaining > (MAXIMUM_FRAME_SIZE - frame_size)) {
ast_websocket_close(session, 1009);
return 0;
}
new_payload = *payload + (frame_size - expected);
/* Read in the remaining payload */
while (remaining > 0) {
size_t payload_read;
/* Wait for data to come in */
if (ast_wait_for_input(session->fd, -1) <= 0) {
*opcode = AST_WEBSOCKET_OPCODE_CLOSE;
*payload = NULL;
session->closing = 1;
return 0;
}
/* If some sort of failure occurs notify the caller */
if ((payload_read = fread(new_payload, 1, remaining, session->f)) < 1) {
return -1;
}
remaining -= payload_read;
new_payload += payload_read;
}
/* 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];
}
}
if (!(new_payload = ast_realloc(session->payload, session->payload_len + *payload_len))) {
*payload_len = 0;
ast_websocket_close(session, 1009);
return 0;
}
/* Per the RFC for PING we need to send back an opcode with the application data as received */
if (*opcode == AST_WEBSOCKET_OPCODE_PING) {
ast_websocket_write(session, AST_WEBSOCKET_OPCODE_PONG, *payload, *payload_len);
}
session->payload = new_payload;
memcpy(session->payload + session->payload_len, *payload, *payload_len);
session->payload_len += *payload_len;
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 if (*opcode == AST_WEBSOCKET_OPCODE_CLOSE) {
char *new_payload;
*payload_len = buf[1] & 0x7f;
/* Make the payload available so the user can look at the reason code if they so desire */
if ((*payload_len) && (new_payload = ast_realloc(session->payload, *payload_len))) {
session->payload = new_payload;
memcpy(session->payload, &buf[2], *payload_len);
*payload = session->payload;
}
if (!session->closing) {
ast_websocket_close(session, 0);
}
fclose(session->f);
session->f = NULL;
ast_verb(2, "WebSocket connection from '%s' closed\n", ast_sockaddr_stringify(&session->address));
} else {
/* 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 Callback that is executed everytime an HTTP request is received by this module */
static int websocket_callback(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;
char *upgrade = NULL, *key = NULL, *key1 = NULL, *key2 = NULL, *protos = NULL, *requested_protocols = NULL, *protocol = NULL;
int version = 0, flags = 1;
struct websocket_protocol *protocol_handler = NULL;
struct ast_websocket *session;
/* 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 -1;
}
/* Get the minimum headers required to satisfy our needs */
for (v = headers; v; v = v->next) {
if (!strcasecmp(v->name, "Upgrade")) {
upgrade = ast_strip(ast_strdupa(v->value));
} else if (!strcasecmp(v->name, "Sec-WebSocket-Key")) {
key = ast_strip(ast_strdupa(v->value));
} else if (!strcasecmp(v->name, "Sec-WebSocket-Key1")) {
key1 = ast_strip(ast_strdupa(v->value));
} else if (!strcasecmp(v->name, "Sec-WebSocket-Key2")) {
key2 = ast_strip(ast_strdupa(v->value));
} else if (!strcasecmp(v->name, "Sec-WebSocket-Protocol")) {
requested_protocols = ast_strip(ast_strdupa(v->value));
protos = ast_strdupa(requested_protocols);
} 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",
ast_sockaddr_stringify(&ser->remote_address));
ast_http_error(ser, 426, "Upgrade Required", NULL);
return -1;
} else if (ast_strlen_zero(requested_protocols)) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - no protocols requested",
ast_sockaddr_stringify(&ser->remote_address));
fputs("HTTP/1.1 400 Bad Request\r\n"
"Sec-WebSocket-Version: 7, 8, 13\r\n\r\n", ser->f);
return -1;
} 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",
ast_sockaddr_stringify(&ser->remote_address));
fputs("HTTP/1.1 400 Bad Request\r\n"
"Sec-WebSocket-Version: 7, 8, 13\r\n\r\n", ser->f);
return 0;
}
/* Iterate through the requested protocols trying to find one that we have a handler for */
while ((protocol = strsep(&requested_protocols, ","))) {
if ((protocol_handler = ao2_find(protocols, ast_strip(protocol), OBJ_KEY))) {
break;
}
}
/* 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);
fputs("HTTP/1.1 400 Bad Request\r\n"
"Sec-WebSocket-Version: 7, 8, 13\r\n\r\n", ser->f);
return 0;
}
/* Determine how to respond depending on the version */
if (version == 7 || version == 8 || version == 13) {
/* Version 7 defined in specification http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-07 */
/* Version 8 defined in specification http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10 */
/* Version 13 defined in specification http://tools.ietf.org/html/rfc6455 */
char combined[strlen(key) + strlen(WEBSOCKET_GUID) + 1], base64[64];
uint8_t sha[20];
if (!(session = ao2_alloc(sizeof(*session), session_destroy_fn))) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted",
ast_sockaddr_stringify(&ser->remote_address));
fputs("HTTP/1.1 400 Bad Request\r\n"
"Sec-WebSocket-Version: 7, 8, 13\r\n\r\n", ser->f);
ao2_ref(protocol_handler, -1);
return 0;
}
snprintf(combined, sizeof(combined), "%s%s", key, WEBSOCKET_GUID);
ast_sha1_hash_uint(sha, combined);
ast_base64encode(base64, (const unsigned char*)sha, 20, sizeof(base64));
fprintf(ser->f, "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,
base64,
protocol);
} 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",
ast_sockaddr_stringify(&ser->remote_address), version ? version : 75);
fputs("HTTP/1.1 400 Bad Request\r\n"
"Sec-WebSocket-Version: 7, 8, 13\r\n\r\n", ser->f);
ao2_ref(protocol_handler, -1);
return 0;
}
/* Enable keepalive on all sessions so the underlying user does not have to */
if (setsockopt(ser->fd, SOL_SOCKET, SO_KEEPALIVE, &flags, sizeof(flags))) {
ast_log(LOG_WARNING, "WebSocket connection from '%s' could not be accepted - failed to enable keepalive",
ast_sockaddr_stringify(&ser->remote_address));
fputs("HTTP/1.1 400 Bad Request\r\n"
"Sec-WebSocket-Version: 7, 8, 13\r\n\r\n", ser->f);
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->f = ser->f;
session->fd = ser->fd;
ast_sockaddr_copy(&session->address, &ser->remote_address);
session->opcode = -1;
session->reconstruct = DEFAULT_RECONSTRUCTION_CEILING;
session->secure = ser->ssl ? 1 : 0;
/* Give up ownership of the socket and pass it to the protocol handler */
protocol_handler->callback(session, get_vars, headers);
ao2_ref(protocol_handler, -1);
/* By dropping the FILE* from the session it won't get closed when the HTTP server cleans up */
ser->f = NULL;
return 0;
}
static struct ast_http_uri websocketuri = {
.callback = websocket_callback,
.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 flags, res;
if ((flags = fcntl(ast_websocket_fd(session), F_GETFL)) == -1) {
goto end;
}
flags |= O_NONBLOCK;
if (fcntl(ast_websocket_fd(session), F_SETFL, flags) == -1) {
goto end;
}
while ((res = ast_wait_for_input(ast_websocket_fd(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 */
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;
}
}
end:
ast_websocket_unref(session);
}
static int load_module(void)
{
protocols = ao2_container_alloc(MAX_PROTOCOL_BUCKETS, protocol_hash_fn, protocol_cmp_fn);
ast_http_uri_link(&websocketuri);
ast_websocket_add_protocol("echo", websocket_echo_callback);
return 0;
}
static int unload_module(void)
{
ast_websocket_remove_protocol("echo", websocket_echo_callback);
ast_http_uri_unlink(&websocketuri);
ao2_ref(protocols, -1);
return 0;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "HTTP WebSocket Support",
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_CHANNEL_DEPEND,
);

17
res/res_http_websocket.exports.in
Unescape View File

@ -0,0 +1,17 @@
{
global:
LINKER_SYMBOL_PREFIXast_websocket_add_protocol;
LINKER_SYMBOL_PREFIXast_websocket_remove_protocol;
LINKER_SYMBOL_PREFIXast_websocket_read;
LINKER_SYMBOL_PREFIXast_websocket_write;
LINKER_SYMBOL_PREFIXast_websocket_close;
LINKER_SYMBOL_PREFIXast_websocket_reconstruct_enable;
LINKER_SYMBOL_PREFIXast_websocket_reconstruct_disable;
LINKER_SYMBOL_PREFIXast_websocket_ref;
LINKER_SYMBOL_PREFIXast_websocket_unref;
LINKER_SYMBOL_PREFIXast_websocket_fd;
LINKER_SYMBOL_PREFIXast_websocket_remote_address;
LINKER_SYMBOL_PREFIXast_websocket_is_secure;
local:
*;
};
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