http_ws.c
No OneTemporary
Actions

Authored By

Unknown

Size

32 KB

Referenced Files

None

Subscribers

None

http_ws.c
View Options

	/* http_ws.c - WebSockets support functions
	*
	* Copyright (c) 1994-2020 Carnegie Mellon University. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in
	* the documentation and/or other materials provided with the
	* distribution.
	*
	* 3. The name "Carnegie Mellon University" must not be used to
	* endorse or promote products derived from this software without
	* prior written permission. For permission or any legal
	* details, please contact
	* Carnegie Mellon University
	* Center for Technology Transfer and Enterprise Creation
	* 4615 Forbes Avenue
	* Suite 302
	* Pittsburgh, PA 15213
	* (412) 268-7393, fax: (412) 268-7395
	* innovation@andrew.cmu.edu
	*
	* 4. Redistributions of any form whatsoever must retain the following
	* acknowledgment:
	* "This product includes software developed by Computing Services
	* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
	*
	* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
	* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
	* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
	* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
	* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
	* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*
	*/

	#include <config.h>
	#include <sysexits.h>

	#include "httpd.h"
	#include "http_ws.h"
	#include "util.h"

	#ifdef HAVE_WSLAY

	#include <errno.h>
	#include <syslog.h>

	#include <sasl/saslutil.h>

	#include "http_h2.h"
	#include "retry.h"
	#include "telemetry.h"
	#include "tok.h"
	#include "xsha1.h"

	/* generated headers are not necessarily in current directory */
	#include "imap/http_err.h"


	#define WS_CKEY_LEN 24
	#define WS_AKEY_LEN 28
	#define WS_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"


	/* WebSocket Extension flags */
	enum {
	EXT_PMCE_DEFLATE = (1<<0) /* Per-Message Compression Ext (RFC 7692) */
	};

	/* Supported WebSocket Extensions */
	static struct ws_extension {
	const char *name;
	unsigned flag;
	} extensions[] = {
	#ifdef HAVE_ZLIB
	{ "permessage-deflate", EXT_PMCE_DEFLATE },
	#endif
	{ NULL, 0 }
	};


	/* WebSocket channel context */
	struct ws_context {
	wslay_event_context_ptr event;
	const char *accept_key;
	const char *protocol;
	ws_data_callback *data_cb;
	struct buf log;
	int log_tail;
	unsigned ext; /* Bitmask of negotiated extension(s) */

	struct buf h2_data; /* Input data pointer when under HTTP/2 */

	union {
	struct {
	void zstrm; / Zlib decompression context */
	unsigned no_context : 1;
	unsigned max_wbits;
	} deflate;
	} pmce;
	};

	static int ws_timeout;


	static const char *wslay_opcode_as_str(enum wslay_opcode opcode)
	{
	switch (opcode) {
	case WSLAY_CONTINUATION_FRAME:
	return "Continuation";
	case WSLAY_TEXT_FRAME:
	return "Text";
	case WSLAY_BINARY_FRAME:
	return "Binary";
	case WSLAY_CONNECTION_CLOSE:
	return "Close";
	case WSLAY_PING:
	return "Ping";
	case WSLAY_PONG:
	return "Pong";
	default:
	return "Unknown opcode";
	}
	}

	static const char *wslay_error_as_str(enum wslay_error err_code)
	{
	switch (err_code) {
	case WSLAY_ERR_WANT_READ:
	return "Want to read more data from peer";
	case WSLAY_ERR_WANT_WRITE:
	return "Want to send more data to peer";
	case WSLAY_ERR_PROTO:
	return "Protocol error";
	case WSLAY_ERR_INVALID_ARGUMENT:
	return "Message is invalid";
	case WSLAY_ERR_INVALID_CALLBACK:
	return "Invalid callback";
	case WSLAY_ERR_NO_MORE_MSG:
	return "Could not queue message";
	case WSLAY_ERR_CALLBACK_FAILURE:
	return "The user callback function failed";
	case WSLAY_ERR_WOULDBLOCK:
	return "Operation would block";
	case WSLAY_ERR_NOMEM:
	return "Out of memory";
	default:
	return (err_code ? "Unknown error code" : "Success");
	}
	}

	static ssize_t h1_send_cb(wslay_event_context_ptr ev,
	const uint8_t *data, size_t len,
	int flags __attribute__((unused)),
	void *user_data)
	{
	struct transaction_t txn = (struct transaction_t ) user_data;

	int r = prot_write(txn->conn->pout, (const char *) data, len);

	xsyslog(LOG_DEBUG, "WS send", "len=<%zu>, r=<%d>", len, r);

	if (r) {
	wslay_event_set_error(ev, WSLAY_ERR_CALLBACK_FAILURE);
	return -1;
	}

	return len;
	}

	static ssize_t h1_recv_cb(wslay_event_context_ptr ev,
	uint8_t *buf, size_t len,
	int flags __attribute__((unused)),
	void *user_data)
	{
	struct transaction_t txn = (struct transaction_t ) user_data;
	struct protstream *pin = txn->conn->pin;
	ssize_t n;

	n = prot_read(pin, (char *) buf, len);
	if (n) {
	/* We received some data - don't block next time
	Note: This callback gets called multiple times until it
	would block. We don't actually want to block and prevent
	output from being submitted */
	prot_NONBLOCK(pin);
	}
	else {
	/* No data - block next time (for client timeout) */
	prot_BLOCK(pin);

	/* XXX Wslay seems to treat any other error as catastrophic and
	sends a close frame on its own, bypassing the logic in ws_input().
	Always return WOULDBLOCK here so we can return appropriate
	status codes and message strings in ws_input().
	*/
	wslay_event_set_error(ev, WSLAY_ERR_WOULDBLOCK);
	}

	xsyslog(LOG_DEBUG, "WS recv", "len=<%zu>, n=<%zd>, eof=<%d>, err=<%s>",
	len, n, pin->eof, pin->error ? pin->error : "");

	return n;
	}

	static ssize_t h2_send_cb(wslay_event_context_ptr ev,
	const uint8_t *data, size_t len,
	int flags, void *user_data)
	{
	struct transaction_t txn = (struct transaction_t ) user_data;
	int last_chunk = (txn->flags.conn & CONN_CLOSE) && !(flags & WSLAY_MSG_MORE);

	int r = txn->conn->resp_body_chunk(txn, (const char *) data, len,
	last_chunk, NULL /* md5ctx */);

	xsyslog(LOG_DEBUG, "WS send", "len=<%zu>, r=<%d>", len, r);

	if (r) {
	wslay_event_set_error(ev, WSLAY_ERR_CALLBACK_FAILURE);
	return -1;
	}

	return len;
	}

	static ssize_t h2_recv_cb(wslay_event_context_ptr ev,
	uint8_t *buf, size_t len,
	int flags __attribute__((unused)),
	void *user_data)
	{
	struct transaction_t txn = (struct transaction_t ) user_data;
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	const char *dataptr = buf_base(&ctx->h2_data);
	size_t datalen = buf_len(&ctx->h2_data);
	ssize_t n;

	if (!dataptr) {
	/* New data has been read into the request body */
	dataptr = buf_base(&txn->req_body.payload);
	datalen = buf_len(&txn->req_body.payload);
	}

	if (!datalen) {
	/* No data */
	wslay_event_set_error(ev, WSLAY_ERR_WOULDBLOCK);

	/* Reset our input data pointer to NULL */
	buf_free(&ctx->h2_data);

	n = -1;
	}
	else {
	/* Don't return more data than requested */
	n = (datalen > len) ? len : datalen;

	/* Copy the input data into the output buffer */
	memcpy(buf, dataptr, n);

	/* Set our input data pointer to the remaining payload (if any) */
	buf_init_ro(&ctx->h2_data, dataptr + n, datalen - n);
	}

	xsyslog(LOG_DEBUG, "WS recv",
	"len=<%zu>, datalen=<%zu>, n=<%zd>", len, datalen, n);

	return n;
	}


	#ifdef HAVE_ZLIB
	#include <zlib.h>

	static void ws_zlib_init(struct transaction_t txn, tok_t params)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	unsigned client_max_wbits = MAX_WBITS;
	char *token;

	ctx->pmce.deflate.max_wbits = MAX_WBITS;

	/* Process parameters */
	while ((token = tok_next(params))) {
	char *value = strchr(token, '=');

	if (value) *value++ = '\0';

	if (!strcmp(token, "server_no_context_takeover")) {
	ctx->pmce.deflate.no_context = 1;
	}
	else if (!strcmp(token, "client_no_context_takeover")) {
	/* Don't HAVE to do anything here */
	}
	else if (!strcmp(token, "server_max_window_bits")) {
	if (value) {
	if (*value == '"') value++;
	ctx->pmce.deflate.max_wbits = atoi(value);
	}
	else ctx->pmce.deflate.max_wbits = 0; /* force error */
	}
	else if (!strcmp(token, "client_max_window_bits")) {
	if (value) {
	if (*value == '"') value++;
	client_max_wbits = atoi(value);
	}
	}
	}

	/* (Re)configure compression context for raw deflate */
	if (txn->zstrm) deflateEnd(txn->zstrm);
	else txn->zstrm = xzmalloc(sizeof(z_stream));

	if (deflateInit2(txn->zstrm, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
	-ctx->pmce.deflate.max_wbits,
	MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK) {
	free(txn->zstrm);
	txn->zstrm = NULL;
	}

	if (txn->zstrm) {
	/* Configure decompression context for raw deflate */
	ctx->pmce.deflate.zstrm = xzmalloc(sizeof(z_stream));
	if (inflateInit2(ctx->pmce.deflate.zstrm, -client_max_wbits) != Z_OK) {
	free(ctx->pmce.deflate.zstrm);
	ctx->pmce.deflate.zstrm = NULL;
	}
	else {
	/* Enable this PMCE */
	ctx->ext = EXT_PMCE_DEFLATE;
	}
	}
	}

	static void ws_zlib_done(struct ws_context *ctx)
	{
	if (ctx->pmce.deflate.zstrm) {
	inflateEnd(ctx->pmce.deflate.zstrm);
	free(ctx->pmce.deflate.zstrm);
	}
	}

	static int zlib_decompress(struct transaction_t *txn,
	const char *buf, unsigned len)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	z_stream *zstrm = ctx->pmce.deflate.zstrm;

	if (!zstrm) {
	xsyslog(LOG_ERR, "WS: no z_stream", NULL);
	return -1;
	}

	zstrm->next_in = (Bytef *) buf;
	zstrm->avail_in = len;

	buf_reset(&txn->zbuf);

	do {
	int zr;

	buf_ensure(&txn->zbuf, 4096);

	zstrm->next_out = (Bytef *) txn->zbuf.s + txn->zbuf.len;
	zstrm->avail_out = txn->zbuf.alloc - txn->zbuf.len;

	zr = inflate(zstrm, Z_SYNC_FLUSH);
	if (!(zr == Z_OK \|\| zr == Z_STREAM_END \|\| zr == Z_BUF_ERROR)) {
	/* something went wrong */
	xsyslog(LOG_ERR, "WS inflate error",
	"zr=<%d>, msg=<%s>", zr, zstrm->msg);
	return -1;
	}

	txn->zbuf.len = txn->zbuf.alloc - zstrm->avail_out;

	} while (!zstrm->avail_out);

	return 0;
	}
	#else /* !HAVE_ZLIB */

	#define MAX_WBITS 0

	static void ws_zlib_init(struct transaction_t *txn __attribute__((unused)),
	tok_t *params __attribute__((unused))) { }

	static void ws_zlib_done(struct ws_context *ctx __attribute__((unused))) { }

	static int zlib_decompress(struct transaction_t *txn __attribute__((unused)),
	const char *buf __attribute__((unused)),
	unsigned len __attribute__((unused)))
	{
	fatal("zlib_decompress() called, but no Zlib", EX_SOFTWARE);
	}

	#endif /* HAVE_ZLIB */


	static void on_frame_recv_start_cb(wslay_event_context_ptr ev __attribute__((unused)),
	const struct wslay_event_on_frame_recv_start_arg *arg,
	void *user_data __attribute__((unused)))
	{
	xsyslog(LOG_DEBUG, "WS frame start",
	"opcode=<%s>, rsv=<0x%x>, fin=<0x%x>, length=<%ld>",
	wslay_opcode_as_str(arg->opcode), arg->rsv, arg->fin, arg->payload_length);
	}

	#define COMP_FAILED_ERR "Compressing message failed"
	#define DECOMP_FAILED_ERR "Decompressing message failed"

	static int queue_msg(struct transaction_t txn, struct buf outbuf,
	struct wslay_event_msg msgarg, uint8_t rsv,
	const char pmce_str, const char err_msg)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;

	/* Compress the server response, if supported by the client */
	if (ctx->ext & EXT_PMCE_DEFLATE) {
	int r = zlib_compress(txn,
	ctx->pmce.deflate.no_context ? COMPRESS_START : 0,
	buf_base(outbuf), buf_len(outbuf));
	if (r) {
	syslog(LOG_ERR, "queue_response(): zlib_compress() failed");

	if (err_msg) *err_msg = COMP_FAILED_ERR;
	return WSLAY_CODE_INTERNAL_SERVER_ERROR;
	}

	/* Trim the trailing 4 bytes */
	buf_truncate(&txn->zbuf, buf_len(&txn->zbuf) - 4);
	buf_move(outbuf, &txn->zbuf);

	*rsv \|= WSLAY_RSV1_BIT;
	if (pmce_str) *pmce_str = "deflate";
	}

	/* Queue the server response */
	msgarg->msg = (const uint8_t *) buf_base(outbuf);
	msgarg->msg_length = buf_len(outbuf);
	wslay_event_queue_msg_ex(ctx->event, msgarg, *rsv);

	return 0;
	}

	static void on_msg_recv_cb(wslay_event_context_ptr ev,
	const struct wslay_event_on_msg_recv_arg *arg,
	void *user_data)
	{
	struct transaction_t txn = (struct transaction_t ) user_data;
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	struct buf inbuf = BUF_INITIALIZER, outbuf = BUF_INITIALIZER;
	struct wslay_event_msg msgarg = { arg->opcode, NULL, 0 };
	uint8_t rsv = WSLAY_RSV_NONE;
	double cmdtime, nettime;
	const char *err_msg;
	const char *pmce_str = NULL;
	int r, err_code = 0;
	int logfd = -1;

	/* Place client request into a buf */
	buf_init_ro(&inbuf, (const char *) arg->msg, arg->msg_length);

	/* Decompress request, if necessary */
	if (wslay_get_rsv1(arg->rsv)) {
	if (ctx->ext & EXT_PMCE_DEFLATE) {
	pmce_str = "deflate";

	/* Add trailing 4 bytes */
	buf_appendmap(&inbuf, "\x00\x00\xff\xff", 4);

	r = zlib_decompress(txn, buf_base(&inbuf), buf_len(&inbuf));
	if (r) {
	xsyslog(LOG_ERR, "WS: zlib_decompress() failed", NULL);
	}
	}
	else {
	xsyslog(LOG_ERR, "WS: unknown PMCE", NULL);
	r = -1;
	}

	if (r) {
	err_code = WSLAY_CODE_PROTOCOL_ERROR;
	err_msg = DECOMP_FAILED_ERR;
	goto err;
	}

	buf_move(&inbuf, &txn->zbuf);
	}

	/* Log the uncompressed client request */
	buf_truncate(&ctx->log, ctx->log_tail);
	buf_printf(&ctx->log, "opcode=%s; rsv=0x%x; length=%ld",
	wslay_opcode_as_str(arg->opcode), arg->rsv, arg->msg_length);
	if (pmce_str) {
	buf_printf(&ctx->log, " [%ld]; pmce=%s", buf_len(&inbuf), pmce_str);
	pmce_str = NULL;
	}

	switch (arg->opcode) {
	case WSLAY_CONNECTION_CLOSE:
	buf_printf(&ctx->log, "; status=%d; msg='%s'", arg->status_code,
	buf_len(&inbuf) ? buf_cstring(&inbuf)+2 : "");
	txn->flags.conn = CONN_CLOSE;
	break;

	case WSLAY_TEXT_FRAME:
	case WSLAY_BINARY_FRAME:
	session_new_id();
	logfd = telemetry_log(httpd_userid, NULL, NULL, 0);
	if (logfd >= 0) {
	/* Telemetry logging */
	struct iovec iov[2];
	int niov = 0;

	buf_reset(&txn->buf);
	buf_printf(&txn->buf, "<" TIME_T_FMT "<", time(NULL)); /* timestamp */
	WRITEV_ADD_TO_IOVEC(iov, niov,
	buf_base(&txn->buf), buf_len(&txn->buf));
	WRITEV_ADD_TO_IOVEC(iov, niov, buf_base(&inbuf), buf_len(&inbuf));
	if (writev(logfd, iov, niov) < 0) {
	syslog(LOG_NOTICE, "IONOTICE: failed to write telemetry for %s", httpd_userid);
	}
	}

	/* Process the request */
	r = ctx->data_cb(txn, arg->opcode, &inbuf, &outbuf, &ctx->log);
	if (r) {
	switch (r) {
	case HTTP_NO_CONTENT:
	/* Nothing to output */
	break;
	case HTTP_SERVER_ERROR:
	err_code = WSLAY_CODE_INTERNAL_SERVER_ERROR;
	break;
	case HTTP_NOT_ACCEPTABLE:
	err_code = WSLAY_CODE_UNSUPPORTED_DATA;
	break;
	default:
	err_code = WSLAY_CODE_INVALID_FRAME_PAYLOAD_DATA;
	break;
	}

	err_msg = error_message(r);
	goto err;
	}

	if (logfd >= 0) {
	/* Telemetry logging */
	struct iovec iov[2];
	int niov = 0;

	buf_reset(&txn->buf);
	buf_printf(&txn->buf, ">" TIME_T_FMT ">", time(NULL)); /* timestamp */
	WRITEV_ADD_TO_IOVEC(iov, niov,
	buf_base(&txn->buf), buf_len(&txn->buf));
	WRITEV_ADD_TO_IOVEC(iov, niov, buf_base(&outbuf), buf_len(&outbuf));
	if (writev(logfd, iov, niov) < 0) {
	syslog(LOG_NOTICE, "IONOTICE: failed to write telemetry for %s", httpd_userid);
	}
	}

	/* Queue the server response */
	size_t orig_len = buf_len(&outbuf);
	err_code = queue_msg(txn, &outbuf, &msgarg, &rsv, &pmce_str, &err_msg);

	/* Log the server response */
	buf_printf(&ctx->log,
	") => \"Success\" (opcode=%s; rsv=0x%x; length=%ld",
	wslay_opcode_as_str(msgarg.opcode), rsv, msgarg.msg_length);
	if (pmce_str) {
	buf_printf(&ctx->log, " [%ld]; pmce=%s", orig_len, pmce_str);
	}

	/* close out the telemetry log for this action */
	if (logfd >= 0) close(logfd);
	logfd = -1;

	break;
	}

	err:
	if (logfd >= 0) close(logfd);

	if (err_code) {
	size_t err_msg_len = strlen(err_msg);

	xsyslog(LOG_DEBUG, "WS close", NULL);
	wslay_event_queue_close(ev, err_code, (uint8_t *) err_msg, err_msg_len);

	/* Log the server response */
	buf_printf(&ctx->log,
	") => \"Fail\" (opcode=%s; rsv=0x%x; length=%ld"
	"; status=%d; msg='%s'",
	wslay_opcode_as_str(WSLAY_CONNECTION_CLOSE), rsv, err_msg_len,
	err_code, err_msg);
	}

	/* Add timing stats */
	cmdtime_endtimer(&cmdtime, &nettime);
	buf_printf(&ctx->log, ") [timing: cmd=%f net=%f total=%f]",
	cmdtime, nettime, cmdtime + nettime);

	syslog(LOG_INFO, "%s", buf_cstring(&ctx->log));

	buf_free(&inbuf);
	buf_free(&outbuf);
	}


	HIDDEN int ws_init(struct http_connection *conn __attribute__((unused)),
	struct buf *serverinfo)
	{
	buf_printf(serverinfo, " Wslay/%s", WSLAY_VERSION);

	ws_timeout = config_getduration(IMAPOPT_WEBSOCKET_TIMEOUT, 'm');

	return (ws_timeout > 0);
	}


	/* Parse Sec-WebSocket-Extensions header(s) for interesting extensions */
	static void parse_extensions(struct transaction_t *txn)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	const char **ext_hdr =
	spool_getheader(txn->req_hdrs, "Sec-WebSocket-Extensions");
	int i;

	/* Look for interesting extensions. Unknown == ignore */
	for (i = 0; ext_hdr && ext_hdr[i]; i++) {
	tok_t ext = TOK_INITIALIZER(ext_hdr[i], ",", TOK_TRIMLEFT\|TOK_TRIMRIGHT);
	char *token;

	while ((token = tok_next(&ext))) {
	struct ws_extension *extp = extensions;
	tok_t param;

	tok_initm(&param, token, ";", TOK_TRIMLEFT\|TOK_TRIMRIGHT);
	token = tok_next(&param);

	/* Locate a matching extension */
	while (extp->name && strcmp(token, extp->name)) extp++;

	/* Check if client wants per-message compression */
	if (config_getswitch(IMAPOPT_HTTPALLOWCOMPRESS)) {
	if (extp->flag == EXT_PMCE_DEFLATE) {
	ws_zlib_init(txn, &param);
	}

	if (ctx->ext) {
	/* Compression has been enabled */
	wslay_event_config_set_allowed_rsv_bits(ctx->event,
	WSLAY_RSV1_BIT);
	}
	}
	tok_fini(&param);
	}

	tok_fini(&ext);
	}
	}


	static void _end_channel(struct transaction_t *txn)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	const char *msg = txn->conn->close_str ? txn->conn->close_str : txn->error.desc;

	if (!ctx) return;

	wslay_event_context_ptr ev = ctx->event;

	/* Close the WS if we haven't already */
	if (wslay_event_get_write_enabled(ev) && !wslay_event_get_close_sent(ev)) {
	int r;

	if (!msg) msg = "Server unavailable";

	xsyslog(LOG_DEBUG, "WS close", "msg=<%s>", msg);

	syslog(LOG_DEBUG, "wslay_event_queue_close(%s)", msg);
	r = wslay_event_queue_close(ev, WSLAY_CODE_GOING_AWAY,
	(uint8_t *) msg, strlen(msg));
	if (r) {
	xsyslog(LOG_ERR, "WS close failed",
	"err=<%s>", wslay_error_as_str(r));
	}
	else {
	r = wslay_event_send(ev);
	if (r) {
	xsyslog(LOG_ERR, "WS send failed",
	"err=<%s>", wslay_error_as_str(r));
	}
	}
	}

	wslay_event_context_free(ev);
	buf_free(&ctx->log);

	ws_zlib_done(ctx);

	free(ctx);

	txn->ws_ctx = NULL;
	}

	static void _h1_shutdown(struct http_connection *conn)
	{
	if (!conn->ws_ctx \|\| !*conn->ws_ctx) return;

	struct transaction_t txn = // dummy transaction
	{ .conn = conn, .ws_ctx = *conn->ws_ctx, .error = { .desc = NULL } };

	_end_channel(&txn);
	}

	HIDDEN int ws_start_channel(struct transaction_t *txn,
	const char protocol, ws_data_callback data_cb)
	{
	int r, resp_code;
	const char *hdr, accept_key = NULL;
	wslay_event_context_ptr ev;
	struct ws_context *ctx;
	struct wslay_event_callbacks callbacks = {
	NULL, /* recv (assigned below) */
	NULL, /* send (assigned below) */
	NULL, /* genmask */
	NULL, /* on_frame_recv_start (debug only) */
	NULL, /* on_frame_recv_chunk */
	NULL, /* on_frame_recv_end */
	on_msg_recv_cb
	};

	/* Check for supported WebSocket version */
	hdr = spool_getheader(txn->req_hdrs, "Sec-WebSocket-Version");
	if (!hdr) {
	txn->error.desc = "Missing WebSocket version";
	return HTTP_BAD_REQUEST;
	}
	else if (hdr[1]) {
	txn->error.desc = "Multiple WebSocket versions";
	return HTTP_BAD_REQUEST;
	}
	else if (strcmp(hdr[0], WS_VERSION)) {
	txn->error.desc = "Unsupported WebSocket version";
	return HTTP_UPGRADE;
	}

	if (protocol) {
	/* Check for supported WebSocket subprotocol */
	int i, found = 0;

	hdr = spool_getheader(txn->req_hdrs, "Sec-WebSocket-Protocol");
	if (!hdr) {
	txn->error.desc = "Missing WebSocket protocol";
	return HTTP_BAD_REQUEST;
	}

	for (i = 0; !found && hdr[i]; i++) {
	tok_t tok = TOK_INITIALIZER(hdr[i], ",", TOK_TRIMLEFT\|TOK_TRIMRIGHT);
	char *token;

	while ((token = tok_next(&tok))) {
	if (!strcmp(token, protocol)) {
	found = 1;
	break;
	}
	}
	tok_fini(&tok);
	}
	if (!found) {
	txn->error.desc = "Unsupported WebSocket protocol";
	return HTTP_BAD_REQUEST;
	}
	}

	if (txn->flags.ver == VER_1_1) {
	unsigned char sha1buf[SHA1_DIGEST_LENGTH];

	/* Check for WebSocket client key */
	hdr = spool_getheader(txn->req_hdrs, "Sec-WebSocket-Key");
	if (!hdr) {
	txn->error.desc = "Missing WebSocket client key";
	return HTTP_BAD_REQUEST;
	}
	else if (hdr[1]) {
	txn->error.desc = "Multiple WebSocket client keys";
	return HTTP_BAD_REQUEST;
	}
	else if (strlen(hdr[0]) != WS_CKEY_LEN) {
	txn->error.desc = "Invalid WebSocket client key";
	return HTTP_BAD_REQUEST;
	}

	/* Create WebSocket accept key */
	buf_setcstr(&txn->buf, hdr[0]);
	buf_appendcstr(&txn->buf, WS_GUID);
	xsha1((u_char *) buf_base(&txn->buf), buf_len(&txn->buf), sha1buf);

	buf_ensure(&txn->buf, WS_AKEY_LEN+1);
	accept_key = buf_base(&txn->buf);

	r = sasl_encode64((char *) sha1buf, SHA1_DIGEST_LENGTH,
	(char *) accept_key, WS_AKEY_LEN+1, NULL);
	if (r != SASL_OK) {
	xsyslog(LOG_WARNING, "WS base64 encode failed", "r=<%d>", r);
	}

	/* Link the WS context into the connection so we can
	properly close the WS during an abnormal shut_down() */
	txn->conn->ws_ctx = &txn->ws_ctx;
	ptrarray_add(&txn->conn->shutdown_callbacks, &_h1_shutdown);

	callbacks.recv_callback = &h1_recv_cb;
	callbacks.send_callback = &h1_send_cb;

	resp_code = HTTP_SWITCH_PROT;
	}
	else {
	/* HTTP/2 - Treat WS data as chunked response */
	txn->flags.te = TE_CHUNKED;

	callbacks.recv_callback = &h2_recv_cb;
	callbacks.send_callback = &h2_send_cb;

	resp_code = HTTP_OK;
	}

	if (config_getswitch(IMAPOPT_DEBUG)) {
	callbacks.on_frame_recv_start_callback = &on_frame_recv_start_cb;
	}

	/* Create server context */
	r = wslay_event_context_server_init(&ev, &callbacks, txn);
	if (r) {
	xsyslog(LOG_WARNING, "WS init failed", "err=<%s>", wslay_error_as_str(r));
	return HTTP_SERVER_ERROR;
	}

	/* Create channel context */
	ctx = xzmalloc(sizeof(struct ws_context));
	ctx->event = ev;
	ctx->accept_key = accept_key;
	ctx->protocol = protocol;
	ctx->data_cb = data_cb;
	txn->ws_ctx = ctx;
	ptrarray_add(&txn->done_callbacks, &_end_channel);

	/* Check for supported WebSocket extensions */
	parse_extensions(txn);

	/* Prepare log buffer */

	/* Add client data */
	buf_printf(&ctx->log, "%s", txn->conn->clienthost);
	if (httpd_userid) buf_printf(&ctx->log, " as \"%s\"", httpd_userid);
	if ((hdr = spool_getheader(txn->req_hdrs, "User-Agent"))) {
	buf_printf(&ctx->log, " with \"%s\"", hdr[0]);
	if ((hdr = spool_getheader(txn->req_hdrs, "X-Client")))
	buf_printf(&ctx->log, " by \"%s\"", hdr[0]);
	else if ((hdr = spool_getheader(txn->req_hdrs, "X-Requested-With")))
	buf_printf(&ctx->log, " by \"%s\"", hdr[0]);
	}

	/* Add request-line */
	buf_printf(&ctx->log, "; \"WebSocket/%s via %s\" (",
	protocol ? protocol : "echo" , txn->req_line.ver);
	if ((hdr = spool_getheader(txn->req_hdrs, ":stream-id"))) {
	buf_printf(&ctx->log, "stream-id=%s; ", hdr[0]);
	}
	ctx->log_tail = buf_len(&ctx->log);

	/* Tell client that WebSocket negotiation has succeeded */
	response_header(resp_code, txn);

	/* Force the response to the client immediately */
	prot_flush(txn->conn->pout);

	/* Don't do telemetry logging in prot layer */
	prot_setlog(txn->conn->pin, PROT_NO_FD);
	prot_setlog(txn->conn->pout, PROT_NO_FD);

	/* Set inactivity timer */
	prot_settimeout(txn->conn->pin, ws_timeout);

	return 0;
	}


	HIDDEN void ws_add_resp_hdrs(struct transaction_t *txn)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;

	if (!ctx) {
	simple_hdr(txn, "Sec-WebSocket-Version", "%s", WS_VERSION);
	return;
	}

	if (ctx->accept_key) {
	simple_hdr(txn, "Sec-WebSocket-Accept", "%s", ctx->accept_key);
	}

	if (ctx->protocol) {
	simple_hdr(txn, "Sec-WebSocket-Protocol", "%s", ctx->protocol);
	}

	if (ctx->ext & EXT_PMCE_DEFLATE) {
	simple_hdr(txn, "Sec-WebSocket-Extensions",
	"permessage-deflate%s; server_max_window_bits=%u",
	ctx->pmce.deflate.no_context ?
	"; server_no_context_takeover" : "",
	ctx->pmce.deflate.max_wbits);
	}
	}


	static void ws_output(struct transaction_t *txn)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	wslay_event_context_ptr ev = ctx->event;
	int want_read = wslay_event_want_read(ev);
	int want_write = wslay_event_want_write(ev);

	errno = 0;

	xsyslog(LOG_DEBUG, "WS output", "eof=<%d>, want read=<%d>, want write=<%d>",
	txn->conn->pin->eof, want_read, want_write);

	if (want_write) {
	/* Send queued frame(s) */
	int r = wslay_event_send(ev);
	if (r) {
	xsyslog(LOG_DEBUG, "WS send failed", "err=<%s>", wslay_error_as_str(r));
	txn->flags.conn = CONN_CLOSE;
	txn->error.desc = wslay_error_as_str(r);
	}
	}
	else if (!want_read) {
	/* Connection is done */
	xsyslog(LOG_DEBUG, "closing connection", NULL);
	txn->flags.conn = CONN_CLOSE;
	}
	}


	HIDDEN void ws_input(struct transaction_t *txn)
	{
	struct ws_context ctx = (struct ws_context ) txn->ws_ctx;
	wslay_event_context_ptr ev = ctx->event;
	int want_read = wslay_event_want_read(ev);
	int want_write = wslay_event_want_write(ev);
	int goaway = txn->conn->close \|\| (txn->flags.conn & CONN_CLOSE);
	struct protstream *pin = txn->conn->pin;

	errno = 0;

	xsyslog(LOG_DEBUG, "WS input",
	"goaway=<%d>, eof=<%d>, want read=<%d>, want write=<%d>",
	goaway, prot_IS_EOF(pin), want_read, want_write);

	if (want_read && !goaway) {
	/* Read frame(s) */
	int r = wslay_event_recv(ev);

	if (prot_IS_EOF(pin)) {
	/* Client closed connection */
	syslog(LOG_DEBUG, "client closed connection");
	wslay_event_shutdown_write(ev);
	txn->flags.conn = CONN_CLOSE;
	}
	else if (prot_error(pin)) {
	/* Client timeout or I/O error */
	goaway = 1;
	txn->error.desc = prot_error(pin);
	}
	else if (r) {
	/* Failure */
	xsyslog(LOG_DEBUG, "WS recv failed", "err=<%s>, prot err=<%s>",
	wslay_error_as_str(r), prot_error(pin));
	goaway = 1;
	txn->error.desc = wslay_error_as_str(r);
	}
	else {
	/* Successfully received frames */
	xsyslog(LOG_DEBUG, "WS recv: success", NULL);

	/* Reset request payload buffer */
	buf_reset(&txn->req_body.payload);
	}
	}

	if (goaway) {
	/* Tell client we are closing session */
	_end_channel(txn);
	txn->flags.conn = CONN_CLOSE;
	return;
	}

	/* Write frame(s) */
	ws_output(txn);

	return;
	}

	HIDDEN void ws_send(struct transaction_t txn, struct buf outbuf)
	{
	struct wslay_event_msg msgarg = { WSLAY_TEXT_FRAME, NULL, 0 };
	uint8_t rsv = WSLAY_RSV_NONE;

	if (!queue_msg(txn, outbuf, &msgarg, &rsv, NULL, NULL)) {
	ws_output(txn);
	}
	}

	#else /* !HAVE_WSLAY */

	HIDDEN int ws_init(struct http_connection *conn __attribute__((unused)),
	struct buf *serverinfo __attribute__((unused)))
	{
	return 0;
	}

	HIDDEN int ws_start_channel(struct transaction_t *txn __attribute__((unused)),
	const char *protocol __attribute__((unused)),
	ws_data_callback *data_cb __attribute__((unused)))
	{
	fatal("ws_start() called, but no Wslay", EX_SOFTWARE);
	}

	HIDDEN void ws_add_resp_hdrs(struct transaction_t *txn __attribute__((unused)))
	{
	}

	HIDDEN void ws_input(struct transaction_t *txn __attribute__((unused)))
	{
	fatal("ws_input() called, but no Wslay", EX_SOFTWARE);
	}

	HIDDEN void ws_send(struct transaction_t *txn __attribute__((unused)),
	struct buf *outbuf __attribute__((unused)))
	{
	fatal("ws_send() called, but no Wslay", EX_SOFTWARE);
	}

	#endif /* HAVE_WSLAY */

File Metadata

Mime Type: text/x-c
Expires: Fri, Apr 24, 10:52 AM (6 d, 14 h ago)
Storage Engine: blob
Storage Format: Raw Data
Storage Handle: 18830229
Default Alt Text: http_ws.c (32 KB)

http_ws.cNo OneTemporaryActions

http_ws.cView Options

File Metadata

Event Timeline

http_ws.c
No OneTemporary
Actions

http_ws.c
View Options