--- /dev/null
+/*
+ * IRC - Internet Relay Chat, ircd/ircd_signal.c
+ * Copyright (C) 1990 Jarkko Oikarinen and
+ * University of Oulu, Computing Center
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 1, or (at your option)
+ * any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/** @file
+ * @brief Signal handlers for ircu.
+ * @version $Id$
+ */
+#include "config.h"
+
+#include "ircd.h"
+#include "ircd_alloc.h"
+#include "ircd_events.h"
+#include "ircd_log.h"
+#include "ircd_signal.h"
+#include "s_conf.h"
+
+/* #include <assert.h> -- Now using assert in ircd_log.h */
+#include <signal.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/** Records a function to be called when a child process terminates. */
+struct ChildRecord {
+ struct ChildRecord *next;
+ SigChldCallBack call;
+ void *datum;
+ pid_t cpid;
+};
+
+/** Counts various types of signals that we receive. */
+static struct tag_SignalCounter {
+ unsigned int alrm; /**< Received SIGALRM count. */
+ unsigned int hup; /**< Received SIGHUP count. */
+ unsigned int chld; /**< Received SIGCHLD count. */
+} SignalCounter;
+
+/** Event generator for SIGHUP. */
+static struct Signal sig_hup;
+/** Event generator for SIGINT. */
+static struct Signal sig_int;
+/** Event generator for SIGTERM. */
+static struct Signal sig_term;
+/** Event generator for SIGCHLD. */
+static struct Signal sig_chld;
+/** List of active child process callback requests. */
+static struct ChildRecord *children;
+/** List of inactive (free) child records. */
+static struct ChildRecord *crec_freelist;
+
+/* Make sure we have a definition for SIGCHLD. */
+#if !defined(SIGCHLD)
+# define SIGCHLD SIGCLD
+#endif
+
+/** Signal handler for SIGALRM.
+ * @param[in] sig Signal number (ignored).
+ */
+static void sigalrm_handler(int sig)
+{
+ ++SignalCounter.alrm;
+}
+
+/** Signal callback for SIGTERM.
+ * @param[in] ev Signal event descriptor.
+ */
+static void sigterm_callback(struct Event* ev)
+{
+ assert(0 != ev_signal(ev));
+ assert(ET_SIGNAL == ev_type(ev));
+ assert(SIGTERM == sig_signal(ev_signal(ev)));
+ assert(SIGTERM == ev_data(ev));
+
+ server_die("received signal SIGTERM");
+}
+
+/** Signal callback for SIGHUP.
+ * @param[in] ev Signal event descriptor.
+ */
+static void sighup_callback(struct Event* ev)
+{
+ assert(0 != ev_signal(ev));
+ assert(ET_SIGNAL == ev_type(ev));
+ assert(SIGHUP == sig_signal(ev_signal(ev)));
+ assert(SIGHUP == ev_data(ev));
+
+ ++SignalCounter.hup;
+ rehash(&me, 1);
+}
+
+/** Signal callback for SIGINT.
+ * @param[in] ev Signal event descriptor.
+ */
+static void sigint_callback(struct Event* ev)
+{
+ assert(0 != ev_signal(ev));
+ assert(ET_SIGNAL == ev_type(ev));
+ assert(SIGINT == sig_signal(ev_signal(ev)));
+ assert(SIGINT == ev_data(ev));
+
+ server_restart("caught signal: SIGINT");
+}
+
+/** Allocate a child callback record.
+ * @return Newly allocated callback record.
+ */
+static struct ChildRecord *alloc_crec(void)
+{
+ struct ChildRecord *crec;
+
+ if (crec_freelist)
+ {
+ crec = crec_freelist;
+ crec_freelist = crec->next;
+ }
+ else
+ {
+ crec = MyCalloc(1, sizeof(*crec));
+ }
+
+ memset(crec, 0, sizeof(*crec));
+ crec->next = NULL;
+ return crec;
+}
+
+/** Release \a crec, which is after \a prev.
+ * @param[in] crec Child process callback record to release.
+ */
+static void release_crec(struct ChildRecord *crec)
+{
+ memset(crec, 0, sizeof(*crec));
+ crec->next = crec_freelist;
+ crec_freelist = crec;
+}
+
+/** Register a function to be called when a child process terminates.
+ * @param[in] child Child process ID.
+ * @param[in] call Function to call when process \a child terminates.
+ * @param[in] datum Additional data parameter to pass to \a call.
+ */
+void register_child(pid_t child, SigChldCallBack call, void *datum)
+{
+ struct ChildRecord *crec;
+
+ crec = alloc_crec();
+ /* Link into #children list. */
+ crec->next = children;
+ children = crec;
+ /* Fill in user fields. */
+ crec->call = call;
+ crec->datum = datum;
+ crec->cpid = child;
+}
+
+/** Unregister all callbacks for a child process, optionally calling
+ * them first.
+ * @param[in] child Child process ID to unregister.
+ * @param[in] do_call If non-zero, make the callbacks.
+ * @param[in] status If \a do_call is non-zero, the child's exit status.
+ */
+static void do_unregister_child(pid_t child, int do_call, int status)
+{
+ struct ChildRecord *crec = children;
+ struct ChildRecord *prev = NULL;
+
+ while (crec != NULL)
+ {
+ if (crec->cpid == child)
+ {
+ if (do_call)
+ crec->call(child, crec->datum, status);
+
+ if (prev)
+ prev->next = crec->next;
+ else
+ children = crec->next;
+
+ release_crec(crec);
+ }
+ else
+ prev = crec;
+ crec = prev ? prev->next : children;
+ }
+}
+
+/** Unregister all callbacks for a child process.
+ * @param[in] child Child process ID to unregister.
+ */
+void unregister_child(pid_t child)
+{
+ do_unregister_child(child, 0, 0);
+}
+
+/** Signal handler for SIGCHLD.
+ * @param[in] ev Signal event descriptor.
+ */
+static void sigchld_callback(struct Event *ev)
+{
+ pid_t cpid;
+ int status;
+
+ ++SignalCounter.chld;
+ do {
+ cpid = waitpid(-1, &status, WNOHANG);
+ if (cpid > 0)
+ do_unregister_child(cpid, 1, status);
+ } while (cpid > 0);
+}
+
+/** Register all necessary signal handlers. */
+void setup_signals(void)
+{
+ struct sigaction act;
+
+ act.sa_handler = SIG_IGN;
+ act.sa_flags = 0;
+ sigemptyset(&act.sa_mask);
+ sigaddset(&act.sa_mask, SIGPIPE);
+ sigaddset(&act.sa_mask, SIGALRM);
+#ifdef SIGWINCH
+ sigaddset(&act.sa_mask, SIGWINCH);
+ sigaction(SIGWINCH, &act, 0);
+#endif
+ sigaction(SIGPIPE, &act, 0);
+
+ act.sa_handler = sigalrm_handler;
+ sigaction(SIGALRM, &act, 0);
+
+ signal_add(&sig_hup, sighup_callback, 0, SIGHUP);
+ signal_add(&sig_int, sigint_callback, 0, SIGINT);
+ signal_add(&sig_term, sigterm_callback, 0, SIGTERM);
+ signal_add(&sig_chld, sigchld_callback, 0, SIGCHLD);
+
+#ifdef HAVE_RESTARTABLE_SYSCALLS
+ /*
+ * At least on Apollo sr10.1 it seems continuing system calls
+ * after signal is the default. The following 'siginterrupt'
+ * should change that default to interrupting calls.
+ */
+ siginterrupt(SIGALRM, 1);
+#endif
+}
+
+/** Kill and clean up all child processes. */
+void reap_children(void)
+{
+ /* Send SIGTERM to all children in process group. Sleep for a
+ * second to let them exit before we try to clean them up.
+ */
+ kill(0, SIGTERM);
+ sleep(1);
+ sigchld_callback(NULL);
+}
projects / ircu2.10.12-pk.git / blobdiff