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/*
* Copyright 2016 IoT.bzh
* Author: José Bollo <jose.bollo@iot.bzh>
*
* Inspired by the work of
*
* 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 <microhttpd.h>
#include <assert.h>
#include <errno.h>
#include <sys/uio.h>
#include <string.h>
#include <json.h>
#include <openssl/sha.h>
#include "websock.h"
#include "afb-req-itf.h"
#include "afb-method.h"
#include "afb-hreq.h"
#include "afb-websock.h"
#include "afb-apis.h"
#include "session.h"
#include "utils-upoll.h"
/**************** WebSocket connection upgrade ****************************/
static const char websocket_s[] = "websocket";
static const char sec_websocket_key_s[] = "Sec-WebSocket-Key";
static const char sec_websocket_version_s[] = "Sec-WebSocket-Version";
static const char sec_websocket_accept_s[] = "Sec-WebSocket-Accept";
static const char sec_websocket_protocol_s[] = "Sec-WebSocket-Protocol";
static const char websocket_guid[] = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
static void enc64(unsigned char *in, char *out)
{
static const char tob64[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
out[0] = tob64[in[0] >> 2];
out[1] = tob64[((in[0] & 0x03) << 4) | ((in[1] & 0xf0) >> 4)];
out[2] = tob64[((in[1] & 0x0f) << 2) | ((in[2] & 0xc0) >> 6)];
out[3] = tob64[in[2] & 0x3f];
}
static void make_accept_value(const char *key, char result[29])
{
unsigned char md[SHA_DIGEST_LENGTH+1];
size_t len = strlen(key);
char *buffer = alloca(len + sizeof websocket_guid - 1);
memcpy(buffer, key, len);
memcpy(buffer + len, websocket_guid, sizeof websocket_guid - 1);
SHA1((const unsigned char *)buffer, (unsigned long)(len + sizeof websocket_guid - 1), md);
assert(SHA_DIGEST_LENGTH == 20);
md[20] = 0;
enc64(&md[0], &result[0]);
enc64(&md[3], &result[4]);
enc64(&md[6], &result[8]);
enc64(&md[9], &result[12]);
enc64(&md[12], &result[16]);
enc64(&md[15], &result[20]);
enc64(&md[18], &result[24]);
result[27] = '=';
result[28] = 0;
}
static int headerhas(const char *header, const char *needle)
{
static const char sep[] = " \t,";
size_t len, n;
n = strlen(needle);
for(;;) {
header += strspn(header, sep);
if (!*header)
return 0;
len = strcspn(header, sep);
if (n == len && 0 == strncasecmp(needle, header, n))
return 1;
header += len;
}
}
int afb_websock_check(struct afb_hreq *hreq, int *later)
{
const char *connection, *upgrade, *key, *version, *protocols;
char acceptval[29];
int vernum;
struct MHD_Response *response;
/* is an upgrade to websocket ? */
upgrade = afb_hreq_get_header(hreq, MHD_HTTP_HEADER_UPGRADE);
if (upgrade == NULL || strcasecmp(upgrade, websocket_s))
return 0;
/* is a connection for upgrade ? */
connection = afb_hreq_get_header(hreq, MHD_HTTP_HEADER_CONNECTION);
if (connection == NULL || !headerhas (connection, MHD_HTTP_HEADER_UPGRADE))
return 0;
/* is a get ? */
if(hreq->method != afb_method_get || strcasecmp(hreq->version, MHD_HTTP_VERSION_1_1))
return 0;
/* has a key and a version ? */
key = afb_hreq_get_header(hreq, sec_websocket_key_s);
version = afb_hreq_get_header(hreq, sec_websocket_version_s);
if (key == NULL || version == NULL)
return 0;
/* is a supported version ? */
vernum = atoi(version);
if (vernum != 13) {
response = MHD_create_response_from_buffer(0, NULL, MHD_RESPMEM_PERSISTENT);
MHD_add_response_header (response, sec_websocket_version_s, "13");
MHD_queue_response (hreq->connection, MHD_HTTP_BAD_REQUEST, response);
MHD_destroy_response (response);
*later = 1;
return 1;
}
/* is the protocol supported ? */
protocols = afb_hreq_get_header(hreq, sec_websocket_protocol_s);
/* send the accept connection */
make_accept_value(key, acceptval);
response = MHD_create_response_from_buffer(0, NULL, MHD_RESPMEM_PERSISTENT);
MHD_add_response_header (response, sec_websocket_accept_s, acceptval);
MHD_add_response_header (response, MHD_HTTP_HEADER_CONNECTION, MHD_HTTP_HEADER_UPGRADE);
MHD_add_response_header (response, MHD_HTTP_HEADER_UPGRADE, websocket_s);
MHD_queue_response (hreq->connection, MHD_HTTP_SWITCHING_PROTOCOLS, response);
MHD_destroy_response (response);
*later = 0;
return 1;
}
/**************** WebSocket handling ****************************/
static ssize_t aws_writev(struct afb_websock *ws, const struct iovec *iov, int iovcnt);
static ssize_t aws_readv(struct afb_websock *ws, const struct iovec *iov, int iovcnt);
static void aws_disconnect(struct afb_websock *ws);
static void aws_on_close(struct afb_websock *ws, uint16_t code, size_t size);
static void aws_on_content(struct afb_websock *ws, int last, size_t size);
static void aws_on_readable(struct afb_websock *ws);
static struct websock_itf aws_itf = {
.writev = (void*)aws_writev,
.readv = (void*)aws_readv,
.disconnect = (void*)aws_disconnect,
.on_ping = NULL,
.on_pong = NULL,
.on_close = (void*)aws_on_close,
.on_text = (void*)aws_on_content,
.on_binary = (void*)aws_on_content,
.on_continue = (void*)aws_on_content,
.on_extension = NULL,
};
struct afb_wsreq
{
struct afb_websock *aws;
struct afb_wsreq *next;
struct json_object *id;
struct json_object *name;
struct json_object *token;
struct json_object *request;
};
struct afb_websock
{
int fd;
struct MHD_Connection *connection;
struct websock *ws;
struct upoll *up;
struct AFB_clientCtx *context;
struct json_tokener *tokener;
struct afb_wsreq *requests;
};
static struct afb_arg wsreq_get(struct afb_wsreq *wsreq, const char *name);
static void wsreq_iterate(struct afb_wsreq *wsreq, int (*iterator)(void *closure, struct afb_arg arg), void *closure);
static void wsreq_fail(struct afb_wsreq *wsreq, const char *status, const char *info);
static void wsreq_success(struct afb_wsreq *wsreq, struct json_object *obj, const char *info);
static int wsreq_session_create(struct afb_wsreq *wsreq);
static int wsreq_session_check(struct afb_wsreq *wsreq, int refresh);
static void wsreq_session_close(struct afb_wsreq *wsreq);
static const struct afb_req_itf wsreq_itf = {
.get = (void*)wsreq_get,
.iterate = (void*)wsreq_iterate,
.fail = (void*)wsreq_fail,
.success = (void*)wsreq_success,
.session_create = (void*)wsreq_session_create,
.session_check = (void*)wsreq_session_check,
.session_close = (void*)wsreq_session_close
};
struct afb_websock *afb_websock_create(struct afb_hreq *hreq)
{
int fd;
struct afb_websock *result;
fd = MHD_get_connection_info(hreq->connection,
MHD_CONNECTION_INFO_CONNECTION_FD)->connect_fd;
fd = dup(fd);
if (fd < 0)
return NULL;
result = malloc(sizeof * result);
if (result == NULL)
goto error;
result->connection = hreq->connection;
result->fd = fd;
result->context = ctxClientGet(afb_hreq_context(hreq));
if (result->context == NULL)
goto error2;
result->tokener = json_tokener_new();
if (result->tokener == NULL)
goto error3;
result->ws = websock_create_v13(&aws_itf, result);
if (result->ws == NULL)
goto error4;
result->up = upoll_open(result->fd, result);
if (result->up == NULL)
goto error5;
upoll_on_readable(result->up, (void*)aws_on_readable);
upoll_on_hangup(result->up, (void*)aws_disconnect);
return result;
error5:
websock_destroy(result->ws);
error4:
json_tokener_free(result->tokener);
error3:
ctxClientPut(result->context);
error2:
free(result);
error:
close(fd);
return NULL;
}
static ssize_t aws_writev(struct afb_websock *ws, const struct iovec *iov, int iovcnt)
{
ssize_t rc;
do {
rc = writev(ws->fd, iov, iovcnt);
} while(rc == -1 && errno == EINTR);
return rc;
}
static ssize_t aws_readv(struct afb_websock *ws, const struct iovec *iov, int iovcnt)
{
ssize_t rc;
do {
rc = readv(ws->fd, iov, iovcnt);
} while(rc == -1 && errno == EINTR);
return rc;
}
static void aws_disconnect(struct afb_websock *ws)
{
upoll_close(ws->up);
websock_destroy(ws->ws);
close(ws->fd);
MHD_resume_connection (ws->connection);
ctxClientPut(ws->context);
json_tokener_free(ws->tokener);
free(ws);
}
static void aws_on_close(struct afb_websock *ws, uint16_t code, size_t size)
{
/* do nothing */
}
static void aws_on_readable(struct afb_websock *ws)
{
websock_dispatch(ws->ws);
}
static int aws_handle_json(struct afb_websock *aws, struct json_object *obj)
{
struct afb_req r;
int count, num;
struct json_object *type, *id, *name, *req, *token;
struct afb_wsreq *wsreq;
const char *api, *verb;
size_t lenapi, lenverb;
/* protocol inspired by http://www.gir.fr/ocppjs/ocpp_srpc_spec.shtml */
/* the object must be an array of 4 or 5 elements */
if (!json_object_is_type(obj, json_type_array))
goto error;
count = json_object_array_length(obj);
if (count < 4 || count > 5)
goto error;
/* get the 5 elements: type id name request token */
type = json_object_array_get_idx(obj, 0);
id = json_object_array_get_idx(obj, 1);
name = json_object_array_get_idx(obj, 2);
req = json_object_array_get_idx(obj, 3);
token = json_object_array_get_idx(obj, 4);
/* check the types: int string string object string */
if (!json_object_is_type(type, json_type_int))
goto error;
if (!json_object_is_type(id, json_type_string))
goto error;
if (!json_object_is_type(name, json_type_string))
goto error;
if (!json_object_is_type(req, json_type_object))
goto error;
if (token != NULL && !json_object_is_type(token, json_type_string))
goto error;
/* the type is only 2 */
num = json_object_get_int(type);
if (num != 2)
goto error;
/* checks the api/verb structure of name */
api = json_object_get_string(name);
for (lenapi = 0 ; api[lenapi] && api[lenapi] != '/' ; lenapi++);
if (!lenapi || !api[lenapi])
goto error;
verb = &api[lenapi+1];
for (lenverb = 0 ; verb[lenverb] && verb[lenverb] != '/' ; lenverb++);
if (!lenverb || verb[lenverb])
goto error;
/* allocates the request data */
wsreq = malloc(sizeof *wsreq);
if (wsreq == NULL)
goto error;
/* fill and record the request */
wsreq->aws = aws;
wsreq->id = json_object_get(id);
wsreq->name = json_object_get(name);
wsreq->token = json_object_get(token);
wsreq->request = json_object_get(req);
wsreq->next = aws->requests;
aws->requests = wsreq;
json_object_put(obj);
r.data = wsreq;
r.itf = &wsreq_itf;
afb_apis_call(r, aws->context, api, lenapi, verb, lenverb);
return 1;
error:
json_object_put(obj);
return 0;
}
static void aws_on_content(struct afb_websock *ws, int last, size_t size)
{
ssize_t rrc;
char buffer[8000];
struct json_object *obj;
json_tokener_reset(ws->tokener);
while(size) {
rrc = websock_read(ws->ws, buffer,
size > sizeof buffer ? sizeof buffer : size);
if (rrc < 0) {
websock_close(ws->ws);
return;
}
size -= (size_t)rrc;
obj = json_tokener_parse_ex(ws->tokener, buffer, (int)rrc);
if (obj != NULL) {
if (!aws_handle_json(ws, obj)) {
websock_close(ws->ws);
return;
}
} else if (json_tokener_get_error(ws->tokener) != json_tokener_continue) {
websock_close(ws->ws);
return;
}
}
}
static struct afb_arg wsreq_get(struct afb_wsreq *wsreq, const char *name)
{
struct afb_arg arg;
struct json_object *value;
if (json_object_object_get_ex(wsreq->request, name, &value)) {
arg.name = name;
arg.value = json_object_get_string(value);
arg.size = strlen(arg.value);
} else {
arg.name = NULL;
arg.value = NULL;
arg.size = 0;
}
arg.path = NULL;
return arg;
}
static void wsreq_iterate(struct afb_wsreq *wsreq, int (*iterator)(void *closure, struct afb_arg arg), void *closure)
{
struct afb_arg arg;
struct json_object_iterator it = json_object_iter_begin(wsreq->request);
struct json_object_iterator end = json_object_iter_end(wsreq->request);
arg.size = 0;
arg.path = NULL;
while(!json_object_iter_equal(&it, &end)) {
arg.name = json_object_iter_peek_name(&it);
arg.value = json_object_get_string(json_object_iter_peek_value(&it));
if (!iterator(closure, arg))
break;
json_object_iter_next(&it);
}
}
static int wsreq_session_create(struct afb_wsreq *wsreq)
{
struct AFB_clientCtx *context = wsreq->aws->context;
if (context->created)
return 0;
return wsreq_session_check(wsreq, 1);
}
static int wsreq_session_check(struct afb_wsreq *wsreq, int refresh)
{
const char *token;
struct AFB_clientCtx *context = wsreq->aws->context;
if (wsreq->token == NULL)
return 0;
token = json_object_get_string(wsreq->token);
if (token == NULL)
return 0;
if (!ctxTokenCheck (context, token))
return 0;
if (refresh) {
ctxTokenNew (context);
}
return 1;
}
static void wsreq_session_close(struct afb_wsreq *wsreq)
{
struct AFB_clientCtx *context = wsreq->aws->context;
ctxClientClose(context);
}
static void wsreq_reply(struct afb_wsreq *wsreq, int retcode, const char *status, const char *info, json_object *resp)
{
json_object *root, *request, *reply;
const char *message;
/* builds the answering structure */
root = json_object_new_object();
json_object_object_add(root, "jtype", json_object_new_string("afb-reply"));
request = json_object_new_object();
json_object_object_add(root, "request", request);
json_object_object_add(request, "status", json_object_new_string(status));
if (info)
json_object_object_add(request, "info", json_object_new_string(info));
if (resp)
json_object_object_add(root, "response", resp);
/* make the reply */
reply = json_object_new_array();
json_object_array_add(reply, json_object_new_int(retcode));
json_object_array_add(reply, wsreq->id);
json_object_array_add(reply, root);
json_object_array_add(reply, json_object_new_string(wsreq->aws->context->token));
/* emits the reply */
message = json_object_to_json_string(reply);
websock_text(wsreq->aws->ws, message, strlen(message));
json_object_put(reply);
/* TODO eliminates the wsreq */
}
static void wsreq_fail(struct afb_wsreq *wsreq, const char *status, const char *info)
{
wsreq_reply(wsreq, 4, status, info, NULL);
}
static void wsreq_success(struct afb_wsreq *wsreq, json_object *obj, const char *info)
{
wsreq_reply(wsreq, 3, "success", info, obj);
}
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