Author: hrs
Date: Sat Dec 31 13:15:52 2016
New Revision: 310974
URL: https://svnweb.freebsd.org/changeset/base/310974
Log:
- Use more descriptive names for variables.
- Set O_CLOEXEC to the signal pipe and /dev/klog.
- Use a single signal handler to catch both SIGHUP and SIGCHLD.
- Fix a bug which did FD_SET() the writer-end of the pipe.
Modified:
head/usr.sbin/syslogd/syslogd.c
Modified: head/usr.sbin/syslogd/syslogd.c
==============================================================================
--- head/usr.sbin/syslogd/syslogd.c Sat Dec 31 13:10:08 2016
(r310973)
+++ head/usr.sbin/syslogd/syslogd.c Sat Dec 31 13:15:52 2016
(r310974)
@@ -321,7 +321,7 @@ static int LogFacPri; /* Put facility an
static int KeepKernFac; /* Keep remotely logged kernel facility */
static int needdofsync = 0; /* Are any file(s) waiting to be fsynced? */
static struct pidfh *pfh;
-static int sigp[2]; /* Pipe to catch a signal during select(). */
+static int sigpipe[2]; /* Pipe to catch a signal during select(). */
static volatile sig_atomic_t MarkSet, WantDie, WantInitialize, WantReapchild;
@@ -341,7 +341,6 @@ static void dofsync(void);
static void domark(int);
static void fprintlog(struct filed *, int, const char *);
static void init(int);
-static void init_sh(int);
static void logerror(const char *);
static void logmsg(int, const char *, const char *, int);
static void log_deadchild(pid_t, int, const char *);
@@ -350,12 +349,12 @@ static int socksetup(struct peer *);
static int socklist_recv_file(struct socklist *);
static int socklist_recv_sock(struct socklist *);
static int socklist_recv_signal(struct socklist *);
+static void sighandler(int);
static int skip_message(const char *, const char *, int);
static void printline(const char *, char *, int);
static void printsys(char *);
static int p_open(const char *, pid_t *);
static void reapchild(int);
-static void reapchild_sh(int);
static const char *ttymsg_check(struct iovec *, int, char *, int);
static void usage(void);
static int validate(struct sockaddr *, const char *);
@@ -582,18 +581,18 @@ main(int argc, char *argv[])
usage();
/* Pipe to catch a signal during select(). */
- s = pipe2(sigp, O_NONBLOCK);
+ s = pipe2(sigpipe, O_CLOEXEC);
if (s < 0) {
err(1, "cannot open a pipe for signals");
} else {
addsock(NULL, 0, &(struct socklist){
- .sl_socket = sigp[1],
+ .sl_socket = sigpipe[0],
.sl_recv = socklist_recv_signal
});
}
/* Listen by default: /dev/klog. */
- s = open(_PATH_KLOG, O_RDONLY|O_NONBLOCK, 0);
+ s = open(_PATH_KLOG, O_RDONLY | O_NONBLOCK | O_CLOEXEC, 0);
if (s < 0) {
dprintf("can't open %s (%d)\n", _PATH_KLOG, errno);
} else {
@@ -646,8 +645,8 @@ main(int argc, char *argv[])
(void)signal(SIGTERM, dodie);
(void)signal(SIGINT, Debug ? dodie : SIG_IGN);
(void)signal(SIGQUIT, Debug ? dodie : SIG_IGN);
- (void)signal(SIGHUP, init_sh);
- (void)signal(SIGCHLD, reapchild_sh);
+ (void)signal(SIGHUP, sighandler);
+ (void)signal(SIGCHLD, sighandler);
(void)signal(SIGALRM, domark);
(void)signal(SIGPIPE, SIG_IGN); /* We'll catch EPIPE instead. */
(void)alarm(TIMERINTVL);
@@ -717,12 +716,31 @@ static int
socklist_recv_signal(struct socklist *sl __unused)
{
ssize_t len;
- static char buf[BUFSIZ];
-
- /* Clear an wake-up signal by reading dummy data. */
- while ((len = read(sigp[0], buf, sizeof(buf))) > 0)
- ;
+ int i, nsig, signo;
+ if (ioctl(sigpipe[0], FIONREAD, &i) != 0) {
+ logerror("ioctl(FIONREAD)");
+ err(1, "signal pipe read failed");
+ }
+ nsig = i / sizeof(signo);
+ dprintf("# of received signals = %d\n", nsig);
+ for (i = 0; i < nsig; i++) {
+ len = read(sigpipe[0], &signo, sizeof(signo));
+ if (len != sizeof(signo)) {
+ logerror("signal pipe read failed");
+ err(1, "signal pipe read failed");
+ }
+ dprintf("Received signal: %d from fd=%d\n", signo,
+ sigpipe[0]);
+ switch (signo) {
+ case SIGHUP:
+ WantInitialize = 1;
+ break;
+ case SIGCHLD:
+ WantReapchild = 1;
+ break;
+ }
+ }
return (0);
}
@@ -1512,17 +1530,6 @@ ttymsg_check(struct iovec *iov, int iovc
}
static void
-reapchild_sh(int signo)
-{
- static char buf[BUFSIZ];
-
- WantReapchild = signo;
- /* Send an wake-up signal to the select() loop. */
- read(sigp[0], buf, sizeof(buf));
- write(sigp[1], &signo, sizeof(signo));
-}
-
-static void
reapchild(int signo __unused)
{
int status;
@@ -1793,20 +1800,17 @@ readconfigfile(FILE *cf, int allow_inclu
}
}
-/*
- * INIT -- Initialize syslogd from configuration table
- */
static void
-init_sh(int signo)
+sighandler(int signo)
{
- static char buf[BUFSIZ];
- WantInitialize = signo;
/* Send an wake-up signal to the select() loop. */
- read(sigp[0], buf, sizeof(buf));
- write(sigp[1], &signo, sizeof(signo));
+ write(sigpipe[1], &signo, sizeof(signo));
}
+/*
+ * INIT -- Initialize syslogd from configuration table
+ */
static void
init(int signo)
{
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