libwebsockets/lib/client-parser.c
Andy Green 3b0066cb3f close: make close notification go through writable
Until now we took the approach if just writing the close notification
broke something, we didn't care because we were closing the connection
anyway.

But with lws_meta, breaking stuff in the parent connection would be a
sticky problem outliving the closing child connection.

So this adds a new wsi state LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION
and makes the send go via the writable callback mechanism.
2017-07-19 08:55:57 +08:00

589 lines
15 KiB
C

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2014 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include "private-libwebsockets.h"
/*
* parsers.c: lws_rx_sm() needs to be roughly kept in
* sync with changes here, esp related to ext draining
*/
int lws_client_rx_sm(struct lws *wsi, unsigned char c)
{
int callback_action = LWS_CALLBACK_CLIENT_RECEIVE;
int handled, n, m, rx_draining_ext = 0;
unsigned short close_code;
struct lws_tokens eff_buf;
unsigned char *pp;
if (wsi->u.ws.rx_draining_ext) {
assert(!c);
eff_buf.token = NULL;
eff_buf.token_len = 0;
lws_remove_wsi_from_draining_ext_list(wsi);
rx_draining_ext = 1;
lwsl_debug("%s: doing draining flow\n", __func__);
goto drain_extension;
}
if (wsi->socket_is_permanently_unusable)
return -1;
switch (wsi->lws_rx_parse_state) {
case LWS_RXPS_NEW:
/* control frames (PING) may interrupt checkable sequences */
wsi->u.ws.defeat_check_utf8 = 0;
switch (wsi->ietf_spec_revision) {
case 13:
wsi->u.ws.opcode = c & 0xf;
/* revisit if an extension wants them... */
switch (wsi->u.ws.opcode) {
case LWSWSOPC_TEXT_FRAME:
wsi->u.ws.rsv_first_msg = (c & 0x70);
wsi->u.ws.continuation_possible = 1;
wsi->u.ws.check_utf8 = lws_check_opt(
wsi->context->options,
LWS_SERVER_OPTION_VALIDATE_UTF8);
wsi->u.ws.utf8 = 0;
break;
case LWSWSOPC_BINARY_FRAME:
wsi->u.ws.rsv_first_msg = (c & 0x70);
wsi->u.ws.check_utf8 = 0;
wsi->u.ws.continuation_possible = 1;
break;
case LWSWSOPC_CONTINUATION:
if (!wsi->u.ws.continuation_possible) {
lwsl_info("disordered continuation\n");
return -1;
}
break;
case LWSWSOPC_CLOSE:
wsi->u.ws.check_utf8 = 0;
wsi->u.ws.utf8 = 0;
break;
case 3:
case 4:
case 5:
case 6:
case 7:
case 0xb:
case 0xc:
case 0xd:
case 0xe:
case 0xf:
lwsl_info("illegal opcode\n");
return -1;
default:
wsi->u.ws.defeat_check_utf8 = 1;
break;
}
wsi->u.ws.rsv = (c & 0x70);
/* revisit if an extension wants them... */
if (
#ifndef LWS_NO_EXTENSIONS
!wsi->count_act_ext &&
#endif
wsi->u.ws.rsv) {
lwsl_info("illegal rsv bits set\n");
return -1;
}
wsi->u.ws.final = !!((c >> 7) & 1);
lwsl_ext("%s: This RX frame Final %d\n", __func__, wsi->u.ws.final);
if (wsi->u.ws.owed_a_fin &&
(wsi->u.ws.opcode == LWSWSOPC_TEXT_FRAME ||
wsi->u.ws.opcode == LWSWSOPC_BINARY_FRAME)) {
lwsl_info("hey you owed us a FIN\n");
return -1;
}
if ((!(wsi->u.ws.opcode & 8)) && wsi->u.ws.final) {
wsi->u.ws.continuation_possible = 0;
wsi->u.ws.owed_a_fin = 0;
}
if ((wsi->u.ws.opcode & 8) && !wsi->u.ws.final) {
lwsl_info("control message cannot be fragmented\n");
return -1;
}
if (!wsi->u.ws.final)
wsi->u.ws.owed_a_fin = 1;
switch (wsi->u.ws.opcode) {
case LWSWSOPC_TEXT_FRAME:
case LWSWSOPC_BINARY_FRAME:
wsi->u.ws.frame_is_binary = wsi->u.ws.opcode ==
LWSWSOPC_BINARY_FRAME;
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
break;
default:
lwsl_err("unknown spec version %02d\n",
wsi->ietf_spec_revision);
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN:
wsi->u.ws.this_frame_masked = !!(c & 0x80);
switch (c & 0x7f) {
case 126:
/* control frames are not allowed to have big lengths */
if (wsi->u.ws.opcode & 8)
goto illegal_ctl_length;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
break;
case 127:
/* control frames are not allowed to have big lengths */
if (wsi->u.ws.opcode & 8)
goto illegal_ctl_length;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
break;
default:
wsi->u.ws.rx_packet_length = c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (c)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_2:
wsi->u.ws.rx_packet_length = c << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_1:
wsi->u.ws.rx_packet_length |= c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_8:
if (c & 0x80) {
lwsl_warn("b63 of length must be zero\n");
/* kill the connection */
return -1;
}
#if defined __LP64__
wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
#else
wsi->u.ws.rx_packet_length = 0;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_7:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_6:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_5:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_4:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_3:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_2:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_1:
wsi->u.ws.rx_packet_length |= (size_t)c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
wsi->u.ws.mask[0] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
wsi->u.ws.mask[1] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
wsi->u.ws.mask[2] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
wsi->u.ws.mask[3] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
break;
case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
assert(wsi->u.ws.rx_ubuf);
if (wsi->u.ws.rx_draining_ext)
goto drain_extension;
if (wsi->u.ws.this_frame_masked && !wsi->u.ws.all_zero_nonce)
c ^= wsi->u.ws.mask[(wsi->u.ws.mask_idx++) & 3];
wsi->u.ws.rx_ubuf[LWS_PRE + (wsi->u.ws.rx_ubuf_head++)] = c;
if (--wsi->u.ws.rx_packet_length == 0) {
/* spill because we have the whole frame */
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
/*
* if there's no protocol max frame size given, we are
* supposed to default to context->pt_serv_buf_size
*/
if (!wsi->protocol->rx_buffer_size &&
wsi->u.ws.rx_ubuf_head != wsi->context->pt_serv_buf_size)
break;
if (wsi->protocol->rx_buffer_size &&
wsi->u.ws.rx_ubuf_head != wsi->protocol->rx_buffer_size)
break;
/* spill because we filled our rx buffer */
spill:
handled = 0;
/*
* is this frame a control packet we should take care of at this
* layer? If so service it and hide it from the user callback
*/
switch (wsi->u.ws.opcode) {
case LWSWSOPC_CLOSE:
pp = (unsigned char *)&wsi->u.ws.rx_ubuf[LWS_PRE];
if (lws_check_opt(wsi->context->options,
LWS_SERVER_OPTION_VALIDATE_UTF8) &&
wsi->u.ws.rx_ubuf_head > 2 &&
lws_check_utf8(&wsi->u.ws.utf8, pp + 2,
wsi->u.ws.rx_ubuf_head - 2))
goto utf8_fail;
/* is this an acknowledgement of our close? */
if (wsi->state == LWSS_AWAITING_CLOSE_ACK) {
/*
* fine he has told us he is closing too, let's
* finish our close
*/
lwsl_parser("seen server's close ack\n");
return -1;
}
lwsl_parser("client sees server close len = %d\n",
wsi->u.ws.rx_ubuf_head);
if (wsi->u.ws.rx_ubuf_head >= 2) {
close_code = (pp[0] << 8) | pp[1];
if (close_code < 1000 ||
close_code == 1004 ||
close_code == 1005 ||
close_code == 1006 ||
close_code == 1012 ||
close_code == 1013 ||
close_code == 1014 ||
close_code == 1015 ||
(close_code >= 1016 && close_code < 3000)
) {
pp[0] = (LWS_CLOSE_STATUS_PROTOCOL_ERR >> 8) & 0xff;
pp[1] = LWS_CLOSE_STATUS_PROTOCOL_ERR & 0xff;
}
}
if (user_callback_handle_rxflow(
wsi->protocol->callback, wsi,
LWS_CALLBACK_WS_PEER_INITIATED_CLOSE,
wsi->user_space, pp,
wsi->u.ws.rx_ubuf_head))
return -1;
if (lws_partial_buffered(wsi))
/*
* if we're in the middle of something,
* we can't do a normal close response and
* have to just close our end.
*/
wsi->socket_is_permanently_unusable = 1;
else
/*
* parrot the close packet payload back
* we do not care about how it went, we are closing
* immediately afterwards
*/
lws_write(wsi, (unsigned char *)&wsi->u.ws.rx_ubuf[LWS_PRE],
wsi->u.ws.rx_ubuf_head,
LWS_WRITE_CLOSE);
wsi->state = LWSS_RETURNED_CLOSE_ALREADY;
/* close the connection */
return -1;
case LWSWSOPC_PING:
lwsl_info("received %d byte ping, sending pong\n",
wsi->u.ws.rx_ubuf_head);
/* he set a close reason on this guy, ignore PING */
if (wsi->u.ws.close_in_ping_buffer_len)
goto ping_drop;
if (wsi->u.ws.ping_pending_flag) {
/*
* there is already a pending ping payload
* we should just log and drop
*/
lwsl_parser("DROP PING since one pending\n");
goto ping_drop;
}
/* control packets can only be < 128 bytes long */
if (wsi->u.ws.rx_ubuf_head > 128 - 3) {
lwsl_parser("DROP PING payload too large\n");
goto ping_drop;
}
/* stash the pong payload */
memcpy(wsi->u.ws.ping_payload_buf + LWS_PRE,
&wsi->u.ws.rx_ubuf[LWS_PRE],
wsi->u.ws.rx_ubuf_head);
wsi->u.ws.ping_payload_len = wsi->u.ws.rx_ubuf_head;
wsi->u.ws.ping_pending_flag = 1;
/* get it sent as soon as possible */
lws_callback_on_writable(wsi);
ping_drop:
wsi->u.ws.rx_ubuf_head = 0;
handled = 1;
break;
case LWSWSOPC_PONG:
lwsl_info("client receied pong\n");
lwsl_hexdump(&wsi->u.ws.rx_ubuf[LWS_PRE],
wsi->u.ws.rx_ubuf_head);
if (wsi->pending_timeout == PENDING_TIMEOUT_WS_PONG_CHECK_GET_PONG) {
lwsl_info("received expected PONG on wsi %p\n", wsi);
lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
}
/* issue it */
callback_action = LWS_CALLBACK_CLIENT_RECEIVE_PONG;
break;
case LWSWSOPC_CONTINUATION:
case LWSWSOPC_TEXT_FRAME:
case LWSWSOPC_BINARY_FRAME:
break;
default:
lwsl_parser("Reserved opc 0x%2X\n", wsi->u.ws.opcode);
/*
* It's something special we can't understand here.
* Pass the payload up to the extension's parsing
* state machine.
*/
eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
if (lws_ext_cb_active(wsi,
LWS_EXT_CB_EXTENDED_PAYLOAD_RX,
&eff_buf, 0) <= 0) { /* not handle or fail */
lwsl_ext("Unhandled ext opc 0x%x\n", wsi->u.ws.opcode);
wsi->u.ws.rx_ubuf_head = 0;
return 0;
}
handled = 1;
break;
}
/*
* No it's real payload, pass it up to the user callback.
* It's nicely buffered with the pre-padding taken care of
* so it can be sent straight out again using lws_write
*/
if (handled)
goto already_done;
eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
drain_extension:
lwsl_ext("%s: passing %d to ext\n", __func__, eff_buf.token_len);
n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_RX, &eff_buf, 0);
lwsl_ext("Ext RX returned %d\n", n);
if (n < 0) {
wsi->socket_is_permanently_unusable = 1;
return -1;
}
lwsl_ext("post inflate eff_buf len %d\n", eff_buf.token_len);
if (rx_draining_ext && !eff_buf.token_len) {
lwsl_err(" --- ignoring zero drain result, ending drain\n");
goto already_done;
}
if (wsi->u.ws.check_utf8 && !wsi->u.ws.defeat_check_utf8) {
if (lws_check_utf8(&wsi->u.ws.utf8,
(unsigned char *)eff_buf.token,
eff_buf.token_len))
goto utf8_fail;
/* we are ending partway through utf-8 character? */
if (!wsi->u.ws.rx_packet_length && wsi->u.ws.final &&
wsi->u.ws.utf8 && !n) {
lwsl_info("FINAL utf8 error\n");
utf8_fail: lwsl_info("utf8 error\n");
return -1;
}
}
if (eff_buf.token_len < 0 &&
callback_action != LWS_CALLBACK_CLIENT_RECEIVE_PONG)
goto already_done;
if (!eff_buf.token)
goto already_done;
eff_buf.token[eff_buf.token_len] = '\0';
if (!wsi->protocol->callback)
goto already_done;
if (callback_action == LWS_CALLBACK_CLIENT_RECEIVE_PONG)
lwsl_info("Client doing pong callback\n");
if (n && eff_buf.token_len)
/* extension had more... main loop will come back
* we want callback to be done with this set, if so,
* because lws_is_final() hides it was final until the
* last chunk
*/
lws_add_wsi_to_draining_ext_list(wsi);
else
lws_remove_wsi_from_draining_ext_list(wsi);
if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
wsi->state == LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION ||
wsi->state == LWSS_AWAITING_CLOSE_ACK)
goto already_done;
m = wsi->protocol->callback(wsi,
(enum lws_callback_reasons)callback_action,
wsi->user_space, eff_buf.token, eff_buf.token_len);
/* if user code wants to close, let caller know */
if (m)
return 1;
already_done:
wsi->u.ws.rx_ubuf_head = 0;
break;
default:
lwsl_err("client rx illegal state\n");
return 1;
}
return 0;
illegal_ctl_length:
lwsl_warn("Control frame asking for extended length is illegal\n");
/* kill the connection */
return -1;
}