syslogd: support "symlink to symlink" for /dev/log; reduce stack usage
function old new delta
create_socket - 134 +134
syslogd_main 1132 865 -267
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 134/-267) Total: -133 bytes
text data bss dec hex filename
775603 974 9420 785997 bfe4d busybox_old
775445 974 9420 785839 bfdaf busybox_unstripped
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index da63ced..e3abcc7 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -467,13 +467,39 @@
}
#endif
-static void do_syslogd(void) ATTRIBUTE_NORETURN;
-static void do_syslogd(void)
+/* Don't inline: prevent struct sockaddr_un to take up space on stack
+ * permanently */
+static NOINLINE int create_socket(void)
{
struct sockaddr_un sunx;
int sock_fd;
char *dev_log_name;
+ memset(&sunx, 0, sizeof(sunx));
+ sunx.sun_family = AF_UNIX;
+
+ /* Unlink old /dev/log or object it points to. */
+ /* (if it exists, bind will fail) */
+ strcpy(sunx.sun_path, "/dev/log");
+ dev_log_name = xmalloc_follow_symlinks("/dev/log");
+ if (dev_log_name) {
+ safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
+ free(dev_log_name);
+ }
+ unlink(sunx.sun_path);
+
+ sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
+ xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
+ chmod("/dev/log", 0666);
+
+ return sock_fd;
+}
+
+static void do_syslogd(void) ATTRIBUTE_NORETURN;
+static void do_syslogd(void)
+{
+ int sock_fd;
+
/* Set up signal handlers */
signal(SIGINT, quit_signal);
signal(SIGTERM, quit_signal);
@@ -487,36 +513,8 @@
signal(SIGALRM, do_mark);
alarm(G.markInterval);
#endif
- remove_pidfile("/var/run/syslogd.pid");
+ sock_fd = create_socket();
- memset(&sunx, 0, sizeof(sunx));
- sunx.sun_family = AF_UNIX;
- strcpy(sunx.sun_path, "/dev/log");
-
- /* Unlink old /dev/log or object it points to. */
- /* (if it exists, bind will fail) */
- logmode = LOGMODE_NONE;
- dev_log_name = xmalloc_readlink_or_warn("/dev/log");
- logmode = LOGMODE_STDIO;
- if (dev_log_name) {
- int fd = xopen(".", O_NONBLOCK);
- xchdir("/dev");
- /* we do not check whether this is a link also */
- unlink(dev_log_name);
- fchdir(fd);
- close(fd);
- safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
- free(dev_log_name);
- } else {
- unlink("/dev/log");
- }
-
- sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
- xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
-
- if (chmod("/dev/log", 0666) < 0) {
- bb_perror_msg_and_die("cannot set permission on /dev/log");
- }
if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
ipcsyslog_init();
}