Merge "Slightly refactor signal handling and fd closing"
diff --git a/src/dnsmasq.c b/src/dnsmasq.c
index 43490cb..5aca297 100755
--- a/src/dnsmasq.c
+++ b/src/dnsmasq.c
@@ -16,6 +16,8 @@
#include "dnsmasq.h"
+#include <sys/stat.h>
+
#if defined(HAVE_BSD_NETWORK)
#error Should not HAVE_BSD_NETWORK
#endif
@@ -75,11 +77,52 @@
static int check_android_listeners(fd_set *set);
#endif
+void setupSignalHandling() {
+ struct sigaction sigact;
+
+ sigact.sa_handler = sig_handler;
+ sigact.sa_flags = 0;
+ sigemptyset(&sigact.sa_mask);
+ sigaction(SIGUSR1, &sigact, NULL);
+ sigaction(SIGUSR2, &sigact, NULL);
+ sigaction(SIGHUP, &sigact, NULL);
+ sigaction(SIGTERM, &sigact, NULL);
+ sigaction(SIGALRM, &sigact, NULL);
+ sigaction(SIGCHLD, &sigact, NULL);
+
+ /* ignore SIGPIPE */
+ sigact.sa_handler = SIG_IGN;
+ sigaction(SIGPIPE, &sigact, NULL);
+}
+
+void closeUnwantedFileDescriptors() {
+ const long kMaxFd = sysconf(_SC_OPEN_MAX);
+ long i;
+ struct stat stat_buf;
+
+ /* Close any file descriptors we inherited apart from std{in|out|err}. */
+ for (i = 0; i < kMaxFd; i++) {
+ // TODO: Evaluate just skipping STDIN, since netd does not
+ // (intentionally) pass in any other file descriptors.
+ if (i == STDOUT_FILENO || i == STDERR_FILENO || i == STDIN_FILENO) {
+ continue;
+ }
+
+ if (fstat(i, &stat_buf) != 0) {
+ if (errno == EBADF) continue;
+ my_syslog(LOG_ERR, "fstat(%d) error: %d/%s", i, errno, strerror(errno));
+ } else {
+ my_syslog(LOG_ERR, "Closing inherited file descriptor %d (%u:%u)",
+ i, stat_buf.st_dev, stat_buf.st_ino);
+ }
+ close(i);
+ }
+}
+
int main (int argc, char **argv)
{
int bind_fallback = 0;
time_t now;
- struct sigaction sigact;
struct iname *if_tmp;
int piperead, pipefd[2], err_pipe[2];
struct passwd *ent_pw = NULL;
@@ -102,19 +145,7 @@
textdomain("dnsmasq");
#endif
- sigact.sa_handler = sig_handler;
- sigact.sa_flags = 0;
- sigemptyset(&sigact.sa_mask);
- sigaction(SIGUSR1, &sigact, NULL);
- sigaction(SIGUSR2, &sigact, NULL);
- sigaction(SIGHUP, &sigact, NULL);
- sigaction(SIGTERM, &sigact, NULL);
- sigaction(SIGALRM, &sigact, NULL);
- sigaction(SIGCHLD, &sigact, NULL);
-
- /* ignore SIGPIPE */
- sigact.sa_handler = SIG_IGN;
- sigaction(SIGPIPE, &sigact, NULL);
+ setupSignalHandling();
umask(022); /* known umask, create leases and pid files as 0644 */
@@ -133,11 +164,8 @@
daemon->lease_file = LEASEFILE;
}
#endif
-
- /* Close any file descriptors we inherited apart from std{in|out|err} */
- for (i = 0; i < max_fd; i++)
- if (i != STDOUT_FILENO && i != STDERR_FILENO && i != STDIN_FILENO)
- close(i);
+
+ closeUnwantedFileDescriptors();
#ifdef HAVE_LINUX_NETWORK
netlink_init();
@@ -589,43 +617,29 @@
}
}
-static void sig_handler(int sig)
-{
- if (pid == 0)
- {
- /* ignore anything other than TERM during startup
- and in helper proc. (helper ignore TERM too) */
- if (sig == SIGTERM)
- exit(EC_MISC);
- }
- else if (pid != getpid())
- {
- /* alarm is used to kill TCP children after a fixed time. */
- if (sig == SIGALRM)
- _exit(0);
- }
- else
- {
- /* master process */
- int event, errsave = errno;
-
- if (sig == SIGHUP)
- event = EVENT_RELOAD;
- else if (sig == SIGCHLD)
- event = EVENT_CHILD;
- else if (sig == SIGALRM)
- event = EVENT_ALARM;
- else if (sig == SIGTERM)
- event = EVENT_TERM;
- else if (sig == SIGUSR1)
- event = EVENT_DUMP;
- else if (sig == SIGUSR2)
- event = EVENT_REOPEN;
- else
- return;
+static void sig_handler(int sig) {
+ if (pid == 0) {
+ /* ignore anything other than TERM during startup
+ and in helper proc. (helper ignore TERM too) */
+ if (sig == SIGTERM) exit(EC_MISC);
+ } else if (pid != getpid()) {
+ /* alarm is used to kill TCP children after a fixed time. */
+ if (sig == SIGALRM) _exit(0);
+ } else {
+ /* master process */
+ const int errsave = errno;
+ int event;
- send_event(pipewrite, event, 0);
- errno = errsave;
+ if (sig == SIGHUP) event = EVENT_RELOAD;
+ else if (sig == SIGCHLD) event = EVENT_CHILD;
+ else if (sig == SIGALRM) event = EVENT_ALARM;
+ else if (sig == SIGTERM) event = EVENT_TERM;
+ else if (sig == SIGUSR1) event = EVENT_DUMP;
+ else if (sig == SIGUSR2) event = EVENT_REOPEN;
+ else return;
+
+ send_event(pipewrite, event, 0);
+ errno = errsave;
}
}
