X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2Flibadacl.c;h=a1923601669b66efb0ffa45e62a9b73695354ddb;hb=0b4ff086871b13edb9da3bda67ac4b6f710e73dd;hp=b25a43b38cba13d055f26ca848241e041fb6d1c7;hpb=81233b65dc8bbccba15394751f240ad59f15f342;p=apply-default-acl.git

diff --git a/src/libadacl.c b/src/libadacl.c
index b25a43b..a192360 100644
--- a/src/libadacl.c
+++ b/src/libadacl.c
@@ -26,22 +26,39 @@
 #include "libadacl.h"
 
 
+/* Even though most other library functions reliably return -1 for
+ * error, it feels a little wrong to re-use the ACL_ERROR constant.
+ */
+#define CLOSE_ERROR -1
+#define OPEN_ERROR -1
+#define SNPRINTF_ERROR -1
+#define STAT_ERROR -1
+
+
 /**
  * @brief The recursive portion of the @c safe_open function, used to
  *   open a file descriptor in a symlink-safe way when combined with
  *   the @c O_NOFOLLOW flag.
  *
+ * The @c O_PATH flag is not used because we want to fail upon
+ * encountering any symlinks.
+ *
  * @param at_fd
  *   A file descriptor relative to which @c pathname will be opened.
  *
  * @param pathname
  *   The path to the file/directory/whatever whose descriptor you want.
  *
+ * @param flags
+ *   File status flags to be passed to @c openat.
+ *
  * @return a file descriptor for @c pathname if everything goes well,
  *   and @c OPEN_ERROR if not.
  */
 int safe_open_ex(int at_fd, char* pathname, int flags) {
-  if (pathname != NULL && strlen(pathname) == 0) {
+  /* We're only called by safe_open(), so pathname is guaranteed to be
+     non-NULL */
+  if (strlen(pathname) == 0) {
     /* Oops, went one level to deep with nothing to do. */
     return at_fd;
   }
@@ -97,6 +114,9 @@ int safe_open_ex(int at_fd, char* pathname, int flags) {
  * @param pathname
  *   The path to the file/directory/whatever whose descriptor you want.
  *
+ * @param flags
+ *   File status flags to be passed to @c openat.
+ *
  * @return a file descriptor for @c pathname if everything goes well,
  *   and @c OPEN_ERROR if not.
  */
@@ -145,6 +165,11 @@ int safe_open(const char* pathname, int flags) {
   }
 
   int fd = open("/", flags);
+  if (fd == OPEN_ERROR) {
+    perror("safe_open (open)");
+    return OPEN_ERROR;
+  }
+
   if (strcmp(abspath, "/") == 0) {
     return fd;
   }