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circuitpython/extmod/modwebsocket.c

319 lines
11 KiB

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Paul Sokolovsky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include "py/nlr.h"
#include "py/obj.h"
#include "py/runtime.h"
#include "py/stream.h"
#include "extmod/modwebsocket.h"
#if MICROPY_PY_WEBSOCKET
enum { FRAME_HEADER, FRAME_OPT, PAYLOAD, CONTROL };
enum { BLOCKING_WRITE = 0x80 };
typedef struct _mp_obj_websocket_t {
mp_obj_base_t base;
mp_obj_t sock;
uint32_t msg_sz;
byte mask[4];
byte state;
byte to_recv;
byte mask_pos;
byte buf_pos;
byte buf[6];
byte opts;
// Copy of last data frame flags
byte ws_flags;
// Copy of current frame flags
byte last_flags;
} mp_obj_websocket_t;
STATIC mp_uint_t websocket_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode);
STATIC mp_obj_t websocket_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
mp_arg_check_num(n_args, n_kw, 1, 2, false);
mp_obj_websocket_t *o = m_new_obj(mp_obj_websocket_t);
o->base.type = type;
o->sock = args[0];
o->state = FRAME_HEADER;
o->to_recv = 2;
o->mask_pos = 0;
o->buf_pos = 0;
o->opts = FRAME_TXT;
if (n_args > 1 && args[1] == mp_const_true) {
o->opts |= BLOCKING_WRITE;
}
return MP_OBJ_FROM_PTR(o);
}
STATIC mp_uint_t websocket_read(mp_obj_t self_in, void *buf, mp_uint_t size, int *errcode) {
mp_obj_websocket_t *self = MP_OBJ_TO_PTR(self_in);
const mp_stream_p_t *stream_p = mp_get_stream_raise(self->sock, MP_STREAM_OP_READ);
while (1) {
if (self->to_recv != 0) {
mp_uint_t out_sz = stream_p->read(self->sock, self->buf + self->buf_pos, self->to_recv, errcode);
if (out_sz == 0 || out_sz == MP_STREAM_ERROR) {
return out_sz;
}
self->buf_pos += out_sz;
self->to_recv -= out_sz;
if (self->to_recv != 0) {
*errcode = EAGAIN;
return MP_STREAM_ERROR;
}
}
switch (self->state) {
case FRAME_HEADER: {
// TODO: Split frame handling below is untested so far, so conservatively disable it
assert(self->buf[0] & 0x80);
// "Control frames MAY be injected in the middle of a fragmented message."
// So, they must be processed before data frames (and not alter
// self->ws_flags)
byte frame_type = self->buf[0];
self->last_flags = frame_type;
frame_type &= FRAME_OPCODE_MASK;
if ((self->buf[0] & FRAME_OPCODE_MASK) == FRAME_CONT) {
// Preserve previous frame type
self->ws_flags = (self->ws_flags & FRAME_OPCODE_MASK) | (self->buf[0] & ~FRAME_OPCODE_MASK);
} else {
self->ws_flags = self->buf[0];
}
// Reset mask in case someone will use "simplified" protocol
// without masks.
memset(self->mask, 0, sizeof(self->mask));
int to_recv = 0;
size_t sz = self->buf[1] & 0x7f;
if (sz == 126) {
// Msg size is next 2 bytes
to_recv += 2;
} else if (sz == 127) {
// Msg size is next 8 bytes
assert(0);
}
if (self->buf[1] & 0x80) {
// Next 4 bytes is mask
to_recv += 4;
}
self->buf_pos = 0;
self->to_recv = to_recv;
self->msg_sz = sz; // May be overridden by FRAME_OPT
if (to_recv != 0) {
self->state = FRAME_OPT;
} else {
if (frame_type >= FRAME_CLOSE) {
self->state = CONTROL;
} else {
self->state = PAYLOAD;
}
}
continue;
}
case FRAME_OPT: {
if ((self->buf_pos & 3) == 2) {
// First two bytes are message length
self->msg_sz = (self->buf[0] << 8) | self->buf[1];
}
if (self->buf_pos >= 4) {
// Last 4 bytes is mask
memcpy(self->mask, self->buf + self->buf_pos - 4, 4);
}
self->buf_pos = 0;
if ((self->last_flags & FRAME_OPCODE_MASK) >= FRAME_CLOSE) {
self->state = CONTROL;
} else {
self->state = PAYLOAD;
}
continue;
}
case PAYLOAD:
case CONTROL: {
mp_uint_t out_sz = 0;
if (self->msg_sz == 0) {
// In case message had zero payload
goto no_payload;
}
size_t sz = MIN(size, self->msg_sz);
out_sz = stream_p->read(self->sock, buf, sz, errcode);
if (out_sz == 0 || out_sz == MP_STREAM_ERROR) {
return out_sz;
}
sz = out_sz;
for (byte *p = buf; sz--; p++) {
*p ^= self->mask[self->mask_pos++ & 3];
}
self->msg_sz -= out_sz;
if (self->msg_sz == 0) {
byte last_state;
no_payload:
last_state = self->state;
self->state = FRAME_HEADER;
self->to_recv = 2;
self->mask_pos = 0;
self->buf_pos = 0;
// Handle control frame
if (last_state == CONTROL) {
byte frame_type = self->last_flags & FRAME_OPCODE_MASK;
if (frame_type == FRAME_CLOSE) {
static char close_resp[2] = {0x88, 0};
int err;
websocket_write(self_in, close_resp, sizeof(close_resp), &err);
return 0;
}
//DEBUG_printf("Finished receiving ctrl message %x, ignoring\n", self->last_flags);
continue;
}
}
if (out_sz != 0) {
return out_sz;
}
// Empty (data) frame received is not EOF
continue;
}
}
}
}
STATIC mp_uint_t websocket_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode) {
mp_obj_websocket_t *self = MP_OBJ_TO_PTR(self_in);
assert(size < 0x10000);
byte header[4] = {0x80 | (self->opts & FRAME_OPCODE_MASK)};
int hdr_sz;
if (size < 126) {
header[1] = size;
hdr_sz = 2;
} else {
header[1] = 126;
header[2] = size >> 8;
header[3] = size & 0xff;
hdr_sz = 4;
}
mp_obj_t dest[3];
if (self->opts & BLOCKING_WRITE) {
mp_load_method(self->sock, MP_QSTR_setblocking, dest);
dest[2] = mp_const_true;
mp_call_method_n_kw(1, 0, dest);
}
mp_uint_t out_sz = mp_stream_write_exactly(self->sock, header, hdr_sz, errcode);
if (*errcode == 0) {
out_sz = mp_stream_write_exactly(self->sock, buf, size, errcode);
}
if (self->opts & BLOCKING_WRITE) {
dest[2] = mp_const_false;
mp_call_method_n_kw(1, 0, dest);
}
if (*errcode != 0) {
return MP_STREAM_ERROR;
}
return out_sz;
}
STATIC mp_uint_t websocket_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t arg, int *errcode) {
mp_obj_websocket_t *self = MP_OBJ_TO_PTR(self_in);
switch (request) {
case MP_STREAM_GET_DATA_OPTS:
return self->ws_flags & FRAME_OPCODE_MASK;
case MP_STREAM_SET_DATA_OPTS: {
int cur = self->opts & FRAME_OPCODE_MASK;
self->opts = (self->opts & ~FRAME_OPCODE_MASK) | (arg & FRAME_OPCODE_MASK);
return cur;
}
default:
*errcode = EINVAL;
return MP_STREAM_ERROR;
}
}
STATIC mp_obj_t websocket_close(mp_obj_t self_in) {
mp_obj_websocket_t *self = MP_OBJ_TO_PTR(self_in);
// TODO: Send close signaling to the other side, otherwise it's
// abrupt close (connection abort).
return mp_stream_close(self->sock);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(websocket_close_obj, websocket_close);
STATIC const mp_rom_map_elem_t websocket_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
{ MP_ROM_QSTR(MP_QSTR_ioctl), MP_ROM_PTR(&mp_stream_ioctl_obj) },
{ MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&websocket_close_obj) },
};
STATIC MP_DEFINE_CONST_DICT(websocket_locals_dict, websocket_locals_dict_table);
STATIC const mp_stream_p_t websocket_stream_p = {
.read = websocket_read,
.write = websocket_write,
.ioctl = websocket_ioctl,
};
STATIC const mp_obj_type_t websocket_type = {
{ &mp_type_type },
.name = MP_QSTR_websocket,
.make_new = websocket_make_new,
.protocol = &websocket_stream_p,
.locals_dict = (void*)&websocket_locals_dict,
};
STATIC const mp_rom_map_elem_t websocket_module_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_websocket) },
{ MP_ROM_QSTR(MP_QSTR_websocket), MP_ROM_PTR(&websocket_type) },
};
STATIC MP_DEFINE_CONST_DICT(websocket_module_globals, websocket_module_globals_table);
const mp_obj_module_t mp_module_websocket = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t*)&websocket_module_globals,
};
#endif // MICROPY_PY_WEBSOCKET