util: loop_write - accept 0-length message

[elogind.git] / src / shared / util.c

diff --git a/src/shared/util.c b/src/shared/util.c
index 9b67dd8296fde6fab7ae3b862bf7ce63fc21e015..d3dacfcfb5300b0d55eb439273c277f2f7c0f0a5 100644 (file)
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -1665,7 +1665,7 @@ int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
 
         errno = 0;
 
-        while (nbytes > 0) {
+        do {
                 ssize_t k;
 
                 k = write(fd, p, nbytes);
@@ -1685,12 +1685,12 @@ int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
                         return -errno;
                 }
 
-                if (k == 0) /* Can't really happen */
+                if (nbytes > 0 && k == 0) /* Can't really happen */
                         return -EIO;
 
                 p += k;
                 nbytes -= k;
-        }
+        } while (nbytes > 0);
 
         return 0;
 }
@@ -5436,6 +5436,15 @@ int is_dir(const char* path, bool follow) {
         return !!S_ISDIR(st.st_mode);
 }
 
+int is_device_node(const char *path) {
+        struct stat info;
+
+        if (lstat(path, &info) < 0)
+                return -errno;
+
+        return !!(S_ISBLK(info.st_mode) || S_ISCHR(info.st_mode));
+}
+
 int unquote_first_word(const char **p, char **ret, UnquoteFlags flags) {
         _cleanup_free_ char *s = NULL;
         size_t allocated = 0, sz = 0;