Edit File: fpm_signals.c
/* (c) 2007,2008 Andrei Nigmatulin */ #include "fpm_config.h" #include <signal.h> #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <errno.h> #include "fpm.h" #include "fpm_signals.h" #include "fpm_sockets.h" #include "fpm_php.h" #include "zlog.h" static int sp[2]; static sigset_t block_sigset; static sigset_t child_block_sigset; const char *fpm_signal_names[NSIG + 1] = { #ifdef SIGHUP [SIGHUP] = "SIGHUP", #endif #ifdef SIGINT [SIGINT] = "SIGINT", #endif #ifdef SIGQUIT [SIGQUIT] = "SIGQUIT", #endif #ifdef SIGILL [SIGILL] = "SIGILL", #endif #ifdef SIGTRAP [SIGTRAP] = "SIGTRAP", #endif #ifdef SIGABRT [SIGABRT] = "SIGABRT", #endif #ifdef SIGEMT [SIGEMT] = "SIGEMT", #endif #ifdef SIGBUS [SIGBUS] = "SIGBUS", #endif #ifdef SIGFPE [SIGFPE] = "SIGFPE", #endif #ifdef SIGKILL [SIGKILL] = "SIGKILL", #endif #ifdef SIGUSR1 [SIGUSR1] = "SIGUSR1", #endif #ifdef SIGSEGV [SIGSEGV] = "SIGSEGV", #endif #ifdef SIGUSR2 [SIGUSR2] = "SIGUSR2", #endif #ifdef SIGPIPE [SIGPIPE] = "SIGPIPE", #endif #ifdef SIGALRM [SIGALRM] = "SIGALRM", #endif #ifdef SIGTERM [SIGTERM] = "SIGTERM", #endif #ifdef SIGCHLD [SIGCHLD] = "SIGCHLD", #endif #ifdef SIGCONT [SIGCONT] = "SIGCONT", #endif #ifdef SIGSTOP [SIGSTOP] = "SIGSTOP", #endif #ifdef SIGTSTP [SIGTSTP] = "SIGTSTP", #endif #ifdef SIGTTIN [SIGTTIN] = "SIGTTIN", #endif #ifdef SIGTTOU [SIGTTOU] = "SIGTTOU", #endif #ifdef SIGURG [SIGURG] = "SIGURG", #endif #ifdef SIGXCPU [SIGXCPU] = "SIGXCPU", #endif #ifdef SIGXFSZ [SIGXFSZ] = "SIGXFSZ", #endif #ifdef SIGVTALRM [SIGVTALRM] = "SIGVTALRM", #endif #ifdef SIGPROF [SIGPROF] = "SIGPROF", #endif #ifdef SIGWINCH [SIGWINCH] = "SIGWINCH", #endif #ifdef SIGINFO [SIGINFO] = "SIGINFO", #endif #ifdef SIGIO [SIGIO] = "SIGIO", #endif #ifdef SIGPWR [SIGPWR] = "SIGPWR", #endif #ifdef SIGSYS [SIGSYS] = "SIGSYS", #endif #ifdef SIGWAITING [SIGWAITING] = "SIGWAITING", #endif #ifdef SIGLWP [SIGLWP] = "SIGLWP", #endif #ifdef SIGFREEZE [SIGFREEZE] = "SIGFREEZE", #endif #ifdef SIGTHAW [SIGTHAW] = "SIGTHAW", #endif #ifdef SIGCANCEL [SIGCANCEL] = "SIGCANCEL", #endif #ifdef SIGLOST [SIGLOST] = "SIGLOST", #endif }; static void sig_soft_quit(int signo) /* {{{ */ { int saved_errno = errno; /* closing fastcgi listening socket will force fcgi_accept() exit immediately */ close(fpm_globals.listening_socket); if (0 > socket(AF_UNIX, SOCK_STREAM, 0)) { zlog(ZLOG_WARNING, "failed to create a new socket"); } fpm_php_soft_quit(); errno = saved_errno; } /* }}} */ static void sig_handler(int signo) /* {{{ */ { static const char sig_chars[NSIG + 1] = { [SIGTERM] = 'T', [SIGINT] = 'I', [SIGUSR1] = '1', [SIGUSR2] = '2', [SIGQUIT] = 'Q', [SIGCHLD] = 'C' }; char s; int saved_errno; if (fpm_globals.parent_pid != getpid()) { /* Avoid using of signal handlers from the master process in a worker before the child sets up its own signal handlers. Normally it is prevented by the sigprocmask() calls around fork(). This execution branch is a last resort trap that has no protection against #76601. */ return; } saved_errno = errno; s = sig_chars[signo]; zend_quiet_write(sp[1], &s, sizeof(s)); errno = saved_errno; } /* }}} */ int fpm_signals_init_main(void) { struct sigaction act; if (0 > socketpair(AF_UNIX, SOCK_STREAM, 0, sp)) { zlog(ZLOG_SYSERROR, "failed to init signals: socketpair()"); return -1; } if (0 > fd_set_blocked(sp[0], 0) || 0 > fd_set_blocked(sp[1], 0)) { zlog(ZLOG_SYSERROR, "failed to init signals: fd_set_blocked()"); return -1; } if (0 > fcntl(sp[0], F_SETFD, FD_CLOEXEC) || 0 > fcntl(sp[1], F_SETFD, FD_CLOEXEC)) { zlog(ZLOG_SYSERROR, "failed to init signals: fcntl(F_SETFD, FD_CLOEXEC)"); return -1; } memset(&act, 0, sizeof(act)); act.sa_handler = sig_handler; sigfillset(&act.sa_mask); if (0 > sigaction(SIGTERM, &act, 0) || 0 > sigaction(SIGINT, &act, 0) || 0 > sigaction(SIGUSR1, &act, 0) || 0 > sigaction(SIGUSR2, &act, 0) || 0 > sigaction(SIGCHLD, &act, 0) || 0 > sigaction(SIGQUIT, &act, 0)) { zlog(ZLOG_SYSERROR, "failed to init signals: sigaction()"); return -1; } zlog(ZLOG_DEBUG, "Unblocking all signals"); if (0 > fpm_signals_unblock()) { return -1; } return 0; } int fpm_signals_init_child(void) { struct sigaction act, act_dfl; memset(&act, 0, sizeof(act)); memset(&act_dfl, 0, sizeof(act_dfl)); act.sa_handler = &sig_soft_quit; act.sa_flags |= SA_RESTART; act_dfl.sa_handler = SIG_DFL; close(sp[0]); close(sp[1]); if (0 > sigaction(SIGTERM, &act_dfl, 0) || 0 > sigaction(SIGINT, &act_dfl, 0) || 0 > sigaction(SIGUSR1, &act_dfl, 0) || 0 > sigaction(SIGUSR2, &act_dfl, 0) || 0 > sigaction(SIGCHLD, &act_dfl, 0) || 0 > sigaction(SIGQUIT, &act, 0)) { zlog(ZLOG_SYSERROR, "failed to init child signals: sigaction()"); return -1; } zend_signal_init(); if (0 > fpm_signals_unblock()) { return -1; } return 0; } int fpm_signals_get_fd(void) { return sp[0]; } int fpm_signals_init_mask(void) { /* Subset of signals from fpm_signals_init_main() and fpm_got_signal() blocked to avoid unexpected death during early init or during reload just after execvp() or fork */ int init_signal_array[] = { SIGUSR1, SIGUSR2, SIGCHLD }; size_t size = sizeof(init_signal_array)/sizeof(init_signal_array[0]); size_t i = 0; if (0 > sigemptyset(&block_sigset) || 0 > sigemptyset(&child_block_sigset)) { zlog(ZLOG_SYSERROR, "failed to prepare signal block mask: sigemptyset()"); return -1; } for (i = 0; i < size; ++i) { int sig_i = init_signal_array[i]; if (0 > sigaddset(&block_sigset, sig_i) || 0 > sigaddset(&child_block_sigset, sig_i)) { if (sig_i <= NSIG && fpm_signal_names[sig_i] != NULL) { zlog(ZLOG_SYSERROR, "failed to prepare signal block mask: sigaddset(%s)", fpm_signal_names[sig_i]); } else { zlog(ZLOG_SYSERROR, "failed to prepare signal block mask: sigaddset(%d)", sig_i); } return -1; } } if (0 > sigaddset(&child_block_sigset, SIGTERM) || 0 > sigaddset(&child_block_sigset, SIGQUIT)) { zlog(ZLOG_SYSERROR, "failed to prepare child signal block mask: sigaddset()"); return -1; } return 0; } int fpm_signals_block(void) { if (0 > sigprocmask(SIG_BLOCK, &block_sigset, NULL)) { zlog(ZLOG_SYSERROR, "failed to block signals"); return -1; } return 0; } int fpm_signals_child_block(void) { if (0 > sigprocmask(SIG_BLOCK, &child_block_sigset, NULL)) { zlog(ZLOG_SYSERROR, "failed to block child signals"); return -1; } return 0; } int fpm_signals_unblock(void) { /* Ensure that during reload after upgrade all signals are unblocked. block_sigset could have different value before execve() */ sigset_t all_signals; sigfillset(&all_signals); if (0 > sigprocmask(SIG_UNBLOCK, &all_signals, NULL)) { zlog(ZLOG_SYSERROR, "failed to unblock signals"); return -1; } return 0; }