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

2 files changed, 30 insertions, 32 deletions

diff --git a/libbb/xreadlink.c b/libbb/xreadlink.c
index 0b6eb05f3..706a3d9ff 100644
--- a/libbb/xreadlink.c
+++ b/libbb/xreadlink.c
@@ -65,7 +65,7 @@ char *xmalloc_follow_symlinks(const char *path)
 
                 if (!--looping) {
                         free(linkpath);
-free_buf_ret_null:
+ free_buf_ret_null:
                         free(buf);
                         return NULL;
                 }
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index da63ced42..e3abcc7cb 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -467,13 +467,39 @@ static void do_mark(int sig)
 }
 #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 @@ static void do_syslogd(void)
         signal(SIGALRM, do_mark);
         alarm(G.markInterval);
 #endif
-        remove_pidfile("/var/run/syslogd.pid");
-
-        memset(&sunx, 0, sizeof(sunx));
-        sunx.sun_family = AF_UNIX;
-        strcpy(sunx.sun_path, "/dev/log");
+        sock_fd = create_socket();
 
-        /* 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();
         }