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libwebsockets/lwsws/main.c
Andy Green 4b7144f763 lws_buflist
For h1 / ws, a combination of removing POLLIN wait and
stashing any unused rx lets us immediately respond to
rx flow control requests in a simple and effective way,
because the tcp socket is the stream.

But for muxed protocols like h2, that technique cannot
be used because we cannot silence the whole bundle of
streams because one can't handle any more rx dynamically.

There are control frames and content for other streams
serialized inbetween the flow controlled stream content.
We have no choice but to read to so we can see the other
things.  Therefore for muxed protocols like h2 and spdy,
rx flow control boils down to tx credit manipulation
on individual streams to staunch the flow at the peer.

However that requires a round trip to take effect, any
transmitted packets that were in flight before the tx credit
reduction arrives at the remote peer are still going to come
and have to be dealt with by adding them to the stash.

This patch introduces lws_buflist scatter-gather type
buffer management for rxflow handling, so we can append
buffer segments in a linked-list to handle whatever rx
is unavoidably in flight on a stream that is trying to
assert rx flow control.
2018-04-19 16:15:10 +08:00

326 lines
7 KiB
C

/*
* libwebsockets web server application
*
* Copyright (C) 2010-2017 Andy Green <andy@warmcat.com>
*
* This file is made available under the Creative Commons CC0 1.0
* Universal Public Domain Dedication.
*
* The person who associated a work with this deed has dedicated
* the work to the public domain by waiving all of his or her rights
* to the work worldwide under copyright law, including all related
* and neighboring rights, to the extent allowed by law. You can copy,
* modify, distribute and perform the work, even for commercial purposes,
* all without asking permission.
*
* The test apps are intended to be adapted for use in your code, which
* may be proprietary. So unlike the library itself, they are licensed
* Public Domain.
*/
#include "lws_config.h"
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <signal.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <assert.h>
#ifndef _WIN32
#include <dirent.h>
#include <syslog.h>
#include <sys/time.h>
#include <unistd.h>
#include <sys/wait.h>
#else
#include <io.h>
#include "gettimeofday.h"
int fork(void)
{
fprintf(stderr, "Sorry Windows doesn't support fork().\n");
return 0;
}
#endif
#include "../lib/libwebsockets.h"
#include <uv.h>
static struct lws_context *context;
static char config_dir[128];
static int opts = 0, do_reload = 1;
static uv_loop_t loop;
static uv_signal_t signal_outer;
static int pids[32];
void lwsl_emit_stderr(int level, const char *line);
#define LWSWS_CONFIG_STRING_SIZE (32 * 1024)
static const struct lws_extension exts[] = {
#if !defined(LWS_WITHOUT_EXTENSIONS)
{
"permessage-deflate",
lws_extension_callback_pm_deflate,
"permessage-deflate"
},
#endif
{ NULL, NULL, NULL /* terminator */ }
};
static const char * const plugin_dirs[] = {
INSTALL_DATADIR"/libwebsockets-test-server/plugins/",
NULL
};
static struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "debug", required_argument, NULL, 'd' },
{ "configdir", required_argument, NULL, 'c' },
{ NULL, 0, 0, 0 }
};
void signal_cb(uv_signal_t *watcher, int signum)
{
switch (watcher->signum) {
case SIGTERM:
case SIGINT:
break;
case SIGHUP:
if (lws_context_is_deprecated(context))
return;
lwsl_notice("Dropping listen sockets\n");
lws_context_deprecate(context, NULL);
return;
default:
signal(SIGABRT, SIG_DFL);
abort();
break;
}
lwsl_err("Signal %d caught\n", watcher->signum);
lws_libuv_stop(context);
}
static int
context_creation(void)
{
int cs_len = LWSWS_CONFIG_STRING_SIZE - 1;
struct lws_context_creation_info info;
char *cs, *config_strings;
cs = config_strings = malloc(LWSWS_CONFIG_STRING_SIZE);
if (!config_strings) {
lwsl_err("Unable to allocate config strings heap\n");
return -1;
}
memset(&info, 0, sizeof(info));
info.external_baggage_free_on_destroy = config_strings;
info.max_http_header_pool = 1024;
info.pt_serv_buf_size = 8192;
info.options = opts | LWS_SERVER_OPTION_VALIDATE_UTF8 |
LWS_SERVER_OPTION_EXPLICIT_VHOSTS |
LWS_SERVER_OPTION_LIBUV;
info.plugin_dirs = plugin_dirs;
lwsl_notice("Using config dir: \"%s\"\n", config_dir);
/*
* first go through the config for creating the outer context
*/
if (lwsws_get_config_globals(&info, config_dir, &cs, &cs_len))
goto init_failed;
context = lws_create_context(&info);
if (context == NULL) {
lwsl_err("libwebsocket init failed\n");
goto init_failed;
}
lws_uv_sigint_cfg(context, 1, signal_cb);
lws_uv_initloop(context, &loop, 0);
/*
* then create the vhosts... protocols are entirely coming from
* plugins, so we leave it NULL
*/
info.extensions = exts;
if (lwsws_get_config_vhosts(context, &info, config_dir,
&cs, &cs_len))
return 1;
return 0;
init_failed:
free(config_strings);
return 1;
}
/*
* root-level sighup handler
*/
static void
reload_handler(int signum)
{
#ifndef _WIN32
int m;
switch (signum) {
case SIGHUP: /* reload */
fprintf(stderr, "root process receives reload\n");
if (!do_reload) {
fprintf(stderr, "passing HUP to child processes\n");
for (m = 0; m < (int)ARRAY_SIZE(pids); m++)
if (pids[m])
kill(pids[m], SIGHUP);
sleep(1);
}
do_reload = 1;
break;
case SIGINT:
case SIGTERM:
case SIGKILL:
fprintf(stderr, "killing service processes\n");
for (m = 0; m < (int)ARRAY_SIZE(pids); m++)
if (pids[m])
kill(pids[m], SIGTERM);
exit(0);
}
#else
// kill() implementation needed for WIN32
#endif
}
int main(int argc, char **argv)
{
int n = 0, debug_level = 7;
#ifndef _WIN32
int m;
int status, syslog_options = LOG_PID | LOG_PERROR;
#endif
strcpy(config_dir, "/etc/lwsws");
while (n >= 0) {
n = getopt_long(argc, argv, "hd:c:", options, NULL);
if (n < 0)
continue;
switch (n) {
case 'd':
debug_level = atoi(optarg);
break;
case 'c':
lws_strncpy(config_dir, optarg, sizeof(config_dir));
break;
case 'h':
fprintf(stderr, "Usage: lwsws [-c <config dir>] "
"[-d <log bitfield>] [--help]\n");
exit(1);
}
}
#ifndef _WIN32
/*
* We leave our original process up permanently, because that
* suits systemd.
*
* Otherwise we get into problems when reload spawns new processes and
* the original one dies randomly.
*/
signal(SIGHUP, reload_handler);
signal(SIGINT, reload_handler);
fprintf(stderr, "Root process is %u\n", getpid());
while (1) {
if (do_reload) {
do_reload = 0;
n = fork();
if (n == 0) /* new */
break;
/* old */
if (n > 0)
for (m = 0; m < (int)ARRAY_SIZE(pids); m++)
if (!pids[m]) {
// fprintf(stderr, "added child pid %d\n", n);
pids[m] = n;
break;
}
}
#ifndef _WIN32
sleep(2);
n = waitpid(-1, &status, WNOHANG);
if (n > 0)
for (m = 0; m < (int)ARRAY_SIZE(pids); m++)
if (pids[m] == n) {
// fprintf(stderr, "reaped child pid %d\n", pids[m]);
pids[m] = 0;
break;
}
#else
// !!! implemenation needed
#endif
}
#endif
/* child process */
#ifndef _WIN32
/* we will only try to log things according to our debug_level */
setlogmask(LOG_UPTO (LOG_DEBUG));
openlog("lwsws", syslog_options, LOG_DAEMON);
#endif
lws_set_log_level(debug_level, lwsl_emit_syslog);
lwsl_notice("lwsws libwebsockets web server - license CC0 + LGPL2.1\n");
lwsl_notice("(C) Copyright 2010-2016 Andy Green <andy@warmcat.com>\n");
#if (UV_VERSION_MAJOR > 0) // Travis...
uv_loop_init(&loop);
#else
fprintf(stderr, "Your libuv is too old!\n");
return 0;
#endif
uv_signal_init(&loop, &signal_outer);
uv_signal_start(&signal_outer, signal_cb, SIGINT);
uv_signal_start(&signal_outer, signal_cb, SIGHUP);
if (context_creation()) {
lwsl_err("Context creation failed\n");
return 1;
}
lws_libuv_run(context, 0);
uv_signal_stop(&signal_outer);
lws_context_destroy(context);
#if (UV_VERSION_MAJOR > 0) // Travis...
lws_close_all_handles_in_loop(&loop);
n = 0;
while (n++ < 4096 && uv_loop_close(&loop))
uv_run(&loop, UV_RUN_NOWAIT);
#endif
lws_context_destroy2(context);
fprintf(stderr, "lwsws exited cleanly\n");
#ifndef _WIN32
closelog();
#endif
context = NULL;
return 0;
}