mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-11 09:50:12 +00:00
Code Issues Releases Activity

- Use more descriptive names for variables.

Browse Source 
- 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.
This commit is contained in:
Hiroki Sato 2016-12-31 13:15:52 +00:00
parent c4df255db7
commit 8ffb87bf8c
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=310974
1 changed files with 39 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

74
usr.sbin/syslogd/syslogd.c
View File

@ -321,7 +321,7 @@ static int LogFacPri; /* Put facility and priority in log message: */
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);
}
@ -1511,17 +1529,6 @@ ttymsg_check(struct iovec *iov, int iovcnt, char *line, int tmout)
return ttymsg(iov, iovcnt, line, tmout);
}
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)
{
@ -1793,20 +1800,17 @@ readconfigfile(FILE *cf, int allow_includes)
}
}
static void
sighandler(int signo)
{
/* Send an wake-up signal to the select() loop. */
write(sigpipe[1], &signo, sizeof(signo));
}
/*
* INIT -- Initialize syslogd from configuration table
*/
static void
init_sh(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));
}
static void
init(int signo)
{