godot/thirdparty/libwebsockets/roles/ws/server-ws.c
2019-05-01 14:41:47 +02:00

837 lines
20 KiB
C

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2018 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 <core/private.h>
#define LWS_CPYAPP(ptr, str) { strcpy(ptr, str); ptr += strlen(str); }
#if !defined(LWS_WITHOUT_EXTENSIONS)
static int
lws_extension_server_handshake(struct lws *wsi, char **p, int budget)
{
struct lws_context *context = wsi->context;
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
char ext_name[64], *args, *end = (*p) + budget - 1;
const struct lws_ext_options *opts, *po;
const struct lws_extension *ext;
struct lws_ext_option_arg oa;
int n, m, more = 1;
int ext_count = 0;
char ignore;
char *c;
/*
* Figure out which extensions the client has that we want to
* enable on this connection, and give him back the list
*/
if (!lws_hdr_total_length(wsi, WSI_TOKEN_EXTENSIONS))
return 0;
/*
* break down the list of client extensions
* and go through them
*/
if (lws_hdr_copy(wsi, (char *)pt->serv_buf, context->pt_serv_buf_size,
WSI_TOKEN_EXTENSIONS) < 0)
return 1;
c = (char *)pt->serv_buf;
lwsl_parser("WSI_TOKEN_EXTENSIONS = '%s'\n", c);
wsi->ws->count_act_ext = 0;
ignore = 0;
n = 0;
args = NULL;
/*
* We may get a simple request
*
* Sec-WebSocket-Extensions: permessage-deflate
*
* or an elaborated one with requested options
*
* Sec-WebSocket-Extensions: permessage-deflate; \
* server_no_context_takeover; \
* client_no_context_takeover
*/
while (more) {
if (c >= (char *)pt->serv_buf + 255)
return -1;
if (*c && (*c != ',' && *c != '\t')) {
if (*c == ';') {
ignore = 1;
if (!args)
args = c + 1;
}
if (ignore || *c == ' ') {
c++;
continue;
}
ext_name[n] = *c++;
if (n < (int)sizeof(ext_name) - 1)
n++;
continue;
}
ext_name[n] = '\0';
ignore = 0;
if (!*c)
more = 0;
else {
c++;
if (!n)
continue;
}
while (args && *args && *args == ' ')
args++;
/* check a client's extension against our support */
ext = wsi->vhost->ws.extensions;
while (ext && ext->callback) {
if (strcmp(ext_name, ext->name)) {
ext++;
continue;
}
/*
* oh, we do support this one he asked for... but let's
* confirm he only gave it once
*/
for (m = 0; m < wsi->ws->count_act_ext; m++)
if (wsi->ws->active_extensions[m] == ext) {
lwsl_info("extension mentioned twice\n");
return 1; /* shenanigans */
}
/*
* ask user code if it's OK to apply it on this
* particular connection + protocol
*/
m = (wsi->protocol->callback)(wsi,
LWS_CALLBACK_CONFIRM_EXTENSION_OKAY,
wsi->user_space, ext_name, 0);
/*
* zero return from callback means go ahead and allow
* the extension, it's what we get if the callback is
* unhandled
*/
if (m) {
ext++;
continue;
}
/* apply it */
ext_count++;
/* instantiate the extension on this conn */
wsi->ws->active_extensions[wsi->ws->count_act_ext] = ext;
/* allow him to construct his context */
if (ext->callback(lws_get_context(wsi), ext, wsi,
LWS_EXT_CB_CONSTRUCT,
(void *)&wsi->ws->act_ext_user[
wsi->ws->count_act_ext],
(void *)&opts, 0)) {
lwsl_info("ext %s failed construction\n",
ext_name);
ext_count--;
ext++;
continue;
}
if (ext_count > 1)
*(*p)++ = ',';
else
LWS_CPYAPP(*p,
"\x0d\x0aSec-WebSocket-Extensions: ");
*p += lws_snprintf(*p, (end - *p), "%s", ext_name);
/*
* The client may send a bunch of different option
* sets for the same extension, we are supposed to
* pick one we like the look of. The option sets are
* separated by comma.
*
* Actually we just either accept the first one or
* nothing.
*
* Go through the options trying to apply the
* recognized ones
*/
lwsl_info("ext args %s\n", args);
while (args && *args && *args != ',') {
while (*args == ' ')
args++;
po = opts;
while (po->name) {
/* only support arg-less options... */
if (po->type != EXTARG_NONE ||
strncmp(args, po->name,
strlen(po->name))) {
po++;
continue;
}
oa.option_name = NULL;
oa.option_index = (int)(po - opts);
oa.start = NULL;
oa.len = 0;
lwsl_info("setting '%s'\n", po->name);
if (!ext->callback(lws_get_context(wsi),
ext, wsi,
LWS_EXT_CB_OPTION_SET,
wsi->ws->act_ext_user[
wsi->ws->count_act_ext],
&oa, (end - *p))) {
*p += lws_snprintf(*p, (end - *p),
"; %s", po->name);
lwsl_debug("adding option %s\n",
po->name);
}
po++;
}
while (*args && *args != ',' && *args != ';')
args++;
if (*args == ';')
args++;
}
wsi->ws->count_act_ext++;
lwsl_parser("cnt_act_ext <- %d\n", wsi->ws->count_act_ext);
if (args && *args == ',')
more = 0;
ext++;
}
n = 0;
args = NULL;
}
return 0;
}
#endif
int
lws_process_ws_upgrade(struct lws *wsi)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
char protocol_list[128], protocol_name[64], *p;
int protocol_len, hit, n = 0, non_space_char_found = 0;
if (!wsi->protocol)
lwsl_err("NULL protocol at lws_read\n");
/*
* It's either websocket or h2->websocket
*
* Select the first protocol we support from the list
* the client sent us.
*
* Copy it to remove header fragmentation
*/
if (lws_hdr_copy(wsi, protocol_list, sizeof(protocol_list) - 1,
WSI_TOKEN_PROTOCOL) < 0) {
lwsl_err("protocol list too long");
return 1;
}
protocol_len = lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL);
protocol_list[protocol_len] = '\0';
p = protocol_list;
hit = 0;
while (*p && !hit) {
n = 0;
non_space_char_found = 0;
while (n < (int)sizeof(protocol_name) - 1 &&
*p && *p != ',') {
/* ignore leading spaces */
if (!non_space_char_found && *p == ' ') {
n++;
continue;
}
non_space_char_found = 1;
protocol_name[n++] = *p++;
}
protocol_name[n] = '\0';
if (*p)
p++;
lwsl_debug("checking %s\n", protocol_name);
n = 0;
while (wsi->vhost->protocols[n].callback) {
lwsl_debug("try %s\n",
wsi->vhost->protocols[n].name);
if (wsi->vhost->protocols[n].name &&
!strcmp(wsi->vhost->protocols[n].name,
protocol_name)) {
wsi->protocol = &wsi->vhost->protocols[n];
hit = 1;
break;
}
n++;
}
}
/* we didn't find a protocol he wanted? */
if (!hit) {
if (lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL)) {
lwsl_notice("No protocol from \"%s\" supported\n",
protocol_list);
return 1;
}
/*
* some clients only have one protocol and
* do not send the protocol list header...
* allow it and match to the vhost's default
* protocol (which itself defaults to zero)
*/
lwsl_info("defaulting to prot handler %d\n",
wsi->vhost->default_protocol_index);
n = wsi->vhost->default_protocol_index;
wsi->protocol = &wsi->vhost->protocols[
(int)wsi->vhost->default_protocol_index];
}
/* allocate the ws struct for the wsi */
wsi->ws = lws_zalloc(sizeof(*wsi->ws), "ws struct");
if (!wsi->ws) {
lwsl_notice("OOM\n");
return 1;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_VERSION))
wsi->ws->ietf_spec_revision =
atoi(lws_hdr_simple_ptr(wsi, WSI_TOKEN_VERSION));
/* allocate wsi->user storage */
if (lws_ensure_user_space(wsi)) {
lwsl_notice("problem with user space\n");
return 1;
}
/*
* Give the user code a chance to study the request and
* have the opportunity to deny it
*/
if ((wsi->protocol->callback)(wsi,
LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
wsi->user_space,
lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL), 0)) {
lwsl_warn("User code denied connection\n");
return 1;
}
/*
* Perform the handshake according to the protocol version the
* client announced
*/
switch (wsi->ws->ietf_spec_revision) {
default:
lwsl_notice("Unknown client spec version %d\n",
wsi->ws->ietf_spec_revision);
wsi->ws->ietf_spec_revision = 13;
//return 1;
/* fallthru */
case 13:
#if defined(LWS_WITH_HTTP2)
if (wsi->h2_stream_carries_ws) {
if (lws_h2_ws_handshake(wsi)) {
lwsl_notice("h2 ws handshake failed\n");
return 1;
}
} else
#endif
{
lwsl_parser("lws_parse calling handshake_04\n");
if (handshake_0405(wsi->context, wsi)) {
lwsl_notice("hs0405 has failed the connection\n");
return 1;
}
}
break;
}
lws_same_vh_protocol_insert(wsi, n);
/*
* We are upgrading to ws, so http/1.1 + h2 and keepalive + pipelined
* header considerations about keeping the ah around no longer apply.
*
* However it's common for the first ws protocol data to have been
* coalesced with the browser upgrade request and to already be in the
* ah rx buffer.
*/
lws_pt_lock(pt, __func__);
if (wsi->h2_stream_carries_ws)
lws_role_transition(wsi, LWSIFR_SERVER | LWSIFR_P_ENCAP_H2,
LRS_ESTABLISHED, &role_ops_ws);
else
lws_role_transition(wsi, LWSIFR_SERVER, LRS_ESTABLISHED,
&role_ops_ws);
lws_pt_unlock(pt);
lws_server_init_wsi_for_ws(wsi);
lwsl_parser("accepted v%02d connection\n", wsi->ws->ietf_spec_revision);
lwsl_info("%s: %p: dropping ah on ws upgrade\n", __func__, wsi);
lws_header_table_detach(wsi, 1);
return 0;
}
int
handshake_0405(struct lws_context *context, struct lws *wsi)
{
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
struct lws_process_html_args args;
unsigned char hash[20];
int n, accept_len;
char *response;
char *p;
if (!lws_hdr_total_length(wsi, WSI_TOKEN_HOST) ||
!lws_hdr_total_length(wsi, WSI_TOKEN_KEY)) {
lwsl_info("handshake_04 missing pieces\n");
/* completed header processing, but missing some bits */
goto bail;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_KEY) >= MAX_WEBSOCKET_04_KEY_LEN) {
lwsl_warn("Client key too long %d\n", MAX_WEBSOCKET_04_KEY_LEN);
goto bail;
}
/*
* since key length is restricted above (currently 128), cannot
* overflow
*/
n = sprintf((char *)pt->serv_buf,
"%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_KEY));
lws_SHA1(pt->serv_buf, n, hash);
accept_len = lws_b64_encode_string((char *)hash, 20,
(char *)pt->serv_buf, context->pt_serv_buf_size);
if (accept_len < 0) {
lwsl_warn("Base64 encoded hash too long\n");
goto bail;
}
/* allocate the per-connection user memory (if any) */
if (lws_ensure_user_space(wsi))
goto bail;
/* create the response packet */
/* make a buffer big enough for everything */
response = (char *)pt->serv_buf + MAX_WEBSOCKET_04_KEY_LEN + 256 + LWS_PRE;
p = response;
LWS_CPYAPP(p, "HTTP/1.1 101 Switching Protocols\x0d\x0a"
"Upgrade: WebSocket\x0d\x0a"
"Connection: Upgrade\x0d\x0a"
"Sec-WebSocket-Accept: ");
strcpy(p, (char *)pt->serv_buf);
p += accept_len;
/* we can only return the protocol header if:
* - one came in, and ... */
if (lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL) &&
/* - it is not an empty string */
wsi->protocol->name &&
wsi->protocol->name[0]) {
LWS_CPYAPP(p, "\x0d\x0aSec-WebSocket-Protocol: ");
p += lws_snprintf(p, 128, "%s", wsi->protocol->name);
}
#if !defined(LWS_WITHOUT_EXTENSIONS)
/*
* Figure out which extensions the client has that we want to
* enable on this connection, and give him back the list.
*
* Give him a limited write bugdet
*/
if (lws_extension_server_handshake(wsi, &p, 192))
goto bail;
#endif
LWS_CPYAPP(p, "\x0d\x0a");
args.p = p;
args.max_len = lws_ptr_diff((char *)pt->serv_buf +
context->pt_serv_buf_size, p);
if (user_callback_handle_rxflow(wsi->protocol->callback, wsi,
LWS_CALLBACK_ADD_HEADERS,
wsi->user_space, &args, 0))
goto bail;
p = args.p;
/* end of response packet */
LWS_CPYAPP(p, "\x0d\x0a");
/* okay send the handshake response accepting the connection */
lwsl_parser("issuing resp pkt %d len\n",
lws_ptr_diff(p, response));
#if defined(DEBUG)
fwrite(response, 1, p - response, stderr);
#endif
n = lws_write(wsi, (unsigned char *)response, p - response,
LWS_WRITE_HTTP_HEADERS);
if (n != (p - response)) {
lwsl_info("%s: ERROR writing to socket %d\n", __func__, n);
goto bail;
}
/* alright clean up and set ourselves into established state */
lwsi_set_state(wsi, LRS_ESTABLISHED);
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
{
const char * uri_ptr =
lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI);
int uri_len = lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI);
const struct lws_http_mount *hit =
lws_find_mount(wsi, uri_ptr, uri_len);
if (hit && hit->cgienv &&
wsi->protocol->callback(wsi, LWS_CALLBACK_HTTP_PMO,
wsi->user_space, (void *)hit->cgienv, 0))
return 1;
}
return 0;
bail:
/* caller will free up his parsing allocations */
return -1;
}
/*
* Once we reach LWS_RXPS_WS_FRAME_PAYLOAD, we know how much
* to expect in that state and can deal with it in bulk more efficiently.
*/
static int
lws_ws_frame_rest_is_payload(struct lws *wsi, uint8_t **buf, size_t len)
{
uint8_t *buffer = *buf, mask[4];
struct lws_tokens ebuf;
unsigned int avail = (unsigned int)len;
#if !defined(LWS_WITHOUT_EXTENSIONS)
unsigned int old_packet_length = (int)wsi->ws->rx_packet_length;
#endif
int n = 0;
/*
* With zlib, we can give it as much input as we like. The pmd
* extension will draw it down in chunks (default 1024).
*
* If we try to restrict how much we give it, because we must go
* back to the event loop each time, we will drop the remainder...
*/
#if !defined(LWS_WITHOUT_EXTENSIONS)
if (!wsi->ws->count_act_ext)
#endif
{
if (wsi->protocol->rx_buffer_size)
avail = (int)wsi->protocol->rx_buffer_size;
else
avail = wsi->context->pt_serv_buf_size;
}
/* do not consume more than we should */
if (avail > wsi->ws->rx_packet_length)
avail = (unsigned int)wsi->ws->rx_packet_length;
/* do not consume more than what is in the buffer */
if (avail > len)
avail = (unsigned int)len;
if (avail <= 0)
return 0;
ebuf.token = (char *)buffer;
ebuf.len = avail;
//lwsl_hexdump_notice(ebuf.token, ebuf.len);
if (!wsi->ws->all_zero_nonce) {
for (n = 0; n < 4; n++)
mask[n] = wsi->ws->mask[(wsi->ws->mask_idx + n) & 3];
/* deal with 4-byte chunks using unwrapped loop */
n = avail >> 2;
while (n--) {
*(buffer) = *(buffer) ^ mask[0];
buffer++;
*(buffer) = *(buffer) ^ mask[1];
buffer++;
*(buffer) = *(buffer) ^ mask[2];
buffer++;
*(buffer) = *(buffer) ^ mask[3];
buffer++;
}
/* and the remaining bytes bytewise */
for (n = 0; n < (int)(avail & 3); n++) {
*(buffer) = *(buffer) ^ mask[n];
buffer++;
}
wsi->ws->mask_idx = (wsi->ws->mask_idx + avail) & 3;
}
lwsl_info("%s: using %d of raw input (total %d on offer)\n", __func__,
avail, (int)len);
(*buf) += avail;
len -= avail;
#if !defined(LWS_WITHOUT_EXTENSIONS)
n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_RX, &ebuf, 0);
lwsl_info("%s: ext says %d / ebuf.len %d\n", __func__, n, ebuf.len);
#endif
/*
* ebuf may be pointing somewhere completely different now,
* it's the output
*/
#if !defined(LWS_WITHOUT_EXTENSIONS)
if (n < 0) {
/*
* we may rely on this to get RX, just drop connection
*/
lwsl_notice("%s: LWS_EXT_CB_PAYLOAD_RX blew out\n", __func__);
wsi->socket_is_permanently_unusable = 1;
return -1;
}
#endif
wsi->ws->rx_packet_length -= avail;
#if !defined(LWS_WITHOUT_EXTENSIONS)
/*
* if we had an rx fragment right at the last compressed byte of the
* message, we can get a zero length inflated output, where no prior
* rx inflated output marked themselves with FIN, since there was
* raw ws payload still to drain at that time.
*
* Then we need to generate a zero length ws rx that can be understood
* as the message completion.
*/
if (!ebuf.len && /* zero-length inflation output */
!n && /* nothing left to drain from the inflator */
wsi->ws->count_act_ext && /* we are using pmd */
old_packet_length && /* we gave the inflator new input */
!wsi->ws->rx_packet_length && /* raw ws packet payload all gone */
wsi->ws->final && /* the raw ws packet is a FIN guy */
wsi->protocol->callback &&
!wsi->wsistate_pre_close) {
if (user_callback_handle_rxflow(wsi->protocol->callback, wsi,
LWS_CALLBACK_RECEIVE,
wsi->user_space, NULL, 0))
return -1;
return avail;
}
#endif
if (!ebuf.len)
return avail;
if (
#if !defined(LWS_WITHOUT_EXTENSIONS)
n &&
#endif
ebuf.len)
/* extension had more... main loop will come back */
lws_add_wsi_to_draining_ext_list(wsi);
else
lws_remove_wsi_from_draining_ext_list(wsi);
if (wsi->ws->check_utf8 && !wsi->ws->defeat_check_utf8) {
if (lws_check_utf8(&wsi->ws->utf8,
(unsigned char *)ebuf.token, ebuf.len)) {
lws_close_reason(wsi, LWS_CLOSE_STATUS_INVALID_PAYLOAD,
(uint8_t *)"bad utf8", 8);
goto utf8_fail;
}
/* we are ending partway through utf-8 character? */
if (!wsi->ws->rx_packet_length && wsi->ws->final &&
wsi->ws->utf8 && !n) {
lwsl_info("FINAL utf8 error\n");
lws_close_reason(wsi, LWS_CLOSE_STATUS_INVALID_PAYLOAD,
(uint8_t *)"partial utf8", 12);
utf8_fail:
lwsl_info("utf8 error\n");
lwsl_hexdump_info(ebuf.token, ebuf.len);
return -1;
}
}
if (wsi->protocol->callback && !wsi->wsistate_pre_close)
if (user_callback_handle_rxflow(wsi->protocol->callback, wsi,
LWS_CALLBACK_RECEIVE,
wsi->user_space,
ebuf.token, ebuf.len))
return -1;
wsi->ws->first_fragment = 0;
#if !defined(LWS_WITHOUT_EXTENSIONS)
lwsl_info("%s: input used %d, output %d, rem len %d, rx_draining_ext %d\n",
__func__, avail, ebuf.len, (int)len, wsi->ws->rx_draining_ext);
#endif
return avail; /* how much we used from the input */
}
int
lws_parse_ws(struct lws *wsi, unsigned char **buf, size_t len)
{
int m, bulk = 0;
lwsl_debug("%s: received %d byte packet\n", __func__, (int)len);
//lwsl_hexdump_notice(*buf, len);
/* let the rx protocol state machine have as much as it needs */
while (len) {
/*
* we were accepting input but now we stopped doing so
*/
if (wsi->rxflow_bitmap) {
lwsl_info("%s: doing rxflow\n", __func__);
lws_rxflow_cache(wsi, *buf, 0, (int)len);
lwsl_parser("%s: cached %ld\n", __func__, (long)len);
*buf += len; /* stashing it is taking care of it */
return 1;
}
#if !defined(LWS_WITHOUT_EXTENSIONS)
if (wsi->ws->rx_draining_ext) {
lwsl_debug("%s: draining rx ext\n", __func__);
m = lws_ws_rx_sm(wsi, ALREADY_PROCESSED_IGNORE_CHAR, 0);
if (m < 0)
return -1;
continue;
}
#endif
/* consume payload bytes efficiently */
while (wsi->lws_rx_parse_state == LWS_RXPS_WS_FRAME_PAYLOAD &&
(wsi->ws->opcode == LWSWSOPC_TEXT_FRAME ||
wsi->ws->opcode == LWSWSOPC_BINARY_FRAME ||
wsi->ws->opcode == LWSWSOPC_CONTINUATION) &&
len) {
uint8_t *bin = *buf;
bulk = 1;
m = lws_ws_frame_rest_is_payload(wsi, buf, len);
assert((int)lws_ptr_diff(*buf, bin) <= (int)len);
len -= lws_ptr_diff(*buf, bin);
if (!m) {
break;
}
if (m < 0) {
lwsl_info("%s: rest_is_payload bailed\n",
__func__);
return -1;
}
}
if (!bulk) {
/* process the byte */
m = lws_ws_rx_sm(wsi, 0, *(*buf)++);
len--;
} else {
/*
* We already handled this byte in bulk, just deal
* with the ramifications
*/
#if !defined(LWS_WITHOUT_EXTENSIONS)
lwsl_debug("%s: coming out of bulk with len %d, "
"wsi->ws->rx_draining_ext %d\n",
__func__, (int)len,
wsi->ws->rx_draining_ext);
#endif
m = lws_ws_rx_sm(wsi, ALREADY_PROCESSED_IGNORE_CHAR |
ALREADY_PROCESSED_NO_CB, 0);
}
if (m < 0) {
lwsl_info("%s: lws_ws_rx_sm bailed %d\n", __func__,
bulk);
return -1;
}
bulk = 0;
}
lwsl_debug("%s: exit with %d unused\n", __func__, (int)len);
return 0;
}