/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2011, 2012 Nicira, Inc.
*
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
*
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, 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.
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
*/
#include <config.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
+#include <stdlib.h>
#include <unistd.h>
#include "poll-loop.h"
#include "socket-util.h"
+#include "type-props.h"
#include "util.h"
+#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(signals);
#if defined(_NSIG)
#define N_SIGNALS _NSIG
#endif
struct signal {
+ struct sigaction saved_sa;
int signr;
};
static bool inited;
if (!inited) {
inited = true;
- if (pipe(fds)) {
- ovs_fatal(errno, "could not create pipe");
- }
- set_nonblocking(fds[0]);
- set_nonblocking(fds[1]);
+ xpipe_nonblocking(fds);
}
}
signal_init();
+ s = xmalloc(sizeof *s);
+ s->signr = signr;
+
/* Set up signal handler. */
assert(signr >= 1 && signr < N_SIGNALS);
memset(&sa, 0, sizeof sa);
sa.sa_handler = signal_handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
- if (sigaction(signr, &sa, NULL)) {
- ovs_fatal(errno, "sigaction(%d) failed", signr);
- }
+ xsigaction(signr, &sa, &s->saved_sa);
- /* Return structure. */
- s = xmalloc(sizeof *s);
- s->signr = signr;
return s;
}
+/* Unregisters the handler for 's', restores the signal handler that was in
+ * effect before signal_register() was called, and frees 's'. */
+void
+signal_unregister(struct signal *s)
+{
+ if (s) {
+ xsigaction(s->signr, &s->saved_sa, NULL);
+ free(s);
+ }
+}
+
/* Returns true if signal 's' has been received since the last call to this
* function with argument 's'. */
bool
signal_poll(struct signal *s)
{
char buf[_POSIX_PIPE_BUF];
- read(fds[0], buf, sizeof buf);
+ ignore(read(fds[0], buf, sizeof buf));
if (signaled[s->signr]) {
signaled[s->signr] = 0;
return true;
signal_handler(int signr)
{
if (signr >= 1 && signr < N_SIGNALS) {
- write(fds[1], "", 1);
+ ignore(write(fds[1], "", 1));
signaled[signr] = true;
}
}
+
+/* Returns the name of signal 'signum' as a string. The string may be in a
+ * static buffer that is reused from one call to the next.
+ *
+ * The string is probably a (possibly multi-word) description of the signal
+ * (e.g. "Hangup") instead of just the stringified version of the macro
+ * (e.g. "SIGHUP"). */
+const char *
+signal_name(int signum)
+{
+ const char *name = NULL;
+#ifdef HAVE_STRSIGNAL
+ name = strsignal(signum);
+#endif
+ if (!name) {
+ static char buffer[7 + INT_STRLEN(int) + 1];
+ sprintf(buffer, "signal %d", signum);
+ name = buffer;
+ }
+ return name;
+}
+
+void
+xsigaction(int signum, const struct sigaction *new, struct sigaction *old)
+{
+ if (sigaction(signum, new, old)) {
+ VLOG_FATAL("sigaction(%s) failed (%s)",
+ signal_name(signum), strerror(errno));
+ }
+}
+
+void
+xsigprocmask(int how, const sigset_t *new, sigset_t *old)
+{
+ if (sigprocmask(how, new, old)) {
+ VLOG_FATAL("sigprocmask failed (%s)", strerror(errno));
+ }
+}