mirror of https://gitee.com/openkylin/qemu.git
99 lines
2.6 KiB
C
99 lines
2.6 KiB
C
/*
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* FUSE: Filesystem in Userspace
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* Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
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*
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* Utility functions for setting signal handlers.
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*
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* This program can be distributed under the terms of the GNU LGPLv2.
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* See the file COPYING.LIB
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*/
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#include "qemu/osdep.h"
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#include "fuse_i.h"
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#include "fuse_lowlevel.h"
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#include <errno.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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static struct fuse_session *fuse_instance;
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static void exit_handler(int sig)
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{
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if (fuse_instance) {
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fuse_session_exit(fuse_instance);
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if (sig <= 0) {
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fuse_log(FUSE_LOG_ERR, "assertion error: signal value <= 0\n");
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abort();
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}
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fuse_instance->error = sig;
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}
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}
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static void do_nothing(int sig)
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{
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(void)sig;
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}
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static int set_one_signal_handler(int sig, void (*handler)(int), int remove)
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{
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struct sigaction sa;
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struct sigaction old_sa;
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memset(&sa, 0, sizeof(struct sigaction));
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sa.sa_handler = remove ? SIG_DFL : handler;
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sigemptyset(&(sa.sa_mask));
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sa.sa_flags = 0;
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if (sigaction(sig, NULL, &old_sa) == -1) {
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fuse_log(FUSE_LOG_ERR, "fuse: cannot get old signal handler: %s\n",
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strerror(errno));
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return -1;
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}
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if (old_sa.sa_handler == (remove ? handler : SIG_DFL) &&
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sigaction(sig, &sa, NULL) == -1) {
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fuse_log(FUSE_LOG_ERR, "fuse: cannot set signal handler: %s\n",
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strerror(errno));
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return -1;
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}
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return 0;
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}
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int fuse_set_signal_handlers(struct fuse_session *se)
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{
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/*
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* If we used SIG_IGN instead of the do_nothing function,
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* then we would be unable to tell if we set SIG_IGN (and
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* thus should reset to SIG_DFL in fuse_remove_signal_handlers)
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* or if it was already set to SIG_IGN (and should be left
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* untouched.
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*/
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if (set_one_signal_handler(SIGHUP, exit_handler, 0) == -1 ||
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set_one_signal_handler(SIGINT, exit_handler, 0) == -1 ||
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set_one_signal_handler(SIGTERM, exit_handler, 0) == -1 ||
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set_one_signal_handler(SIGPIPE, do_nothing, 0) == -1) {
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return -1;
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}
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fuse_instance = se;
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return 0;
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}
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void fuse_remove_signal_handlers(struct fuse_session *se)
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{
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if (fuse_instance != se) {
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fuse_log(FUSE_LOG_ERR,
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"fuse: fuse_remove_signal_handlers: unknown session\n");
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} else {
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fuse_instance = NULL;
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}
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set_one_signal_handler(SIGHUP, exit_handler, 1);
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set_one_signal_handler(SIGINT, exit_handler, 1);
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set_one_signal_handler(SIGTERM, exit_handler, 1);
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set_one_signal_handler(SIGPIPE, do_nothing, 1);
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}
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