X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2Fapply-default-acl.c;h=c4d0c3b9b4871094edf9f08a5053c0bf083cf653;hb=df929bebddb9852c8e50481169e2fd1b5a01faf6;hp=de4e1acc3b7b7cd10654ac4e389814d0786c6d89;hpb=a7187b9c820583d75581c6fe7e26e38ed9e24f7e;p=apply-default-acl.git

diff --git a/src/apply-default-acl.c b/src/apply-default-acl.c
index de4e1ac..c4d0c3b 100644
--- a/src/apply-default-acl.c
+++ b/src/apply-default-acl.c
@@ -34,87 +34,6 @@
 
 
 
-/**
- * @brief Get the mode bits from the given file descriptor.
- *
- * @param fd
- *   The file descriptor (which may reference a directory) whose
- *   mode we want.
- *
- * @return A mode_t (st_mode) structure containing the mode bits.
- *   See sys/stat.h for details.
- */
-mode_t get_mode(int fd) {
-  if (fd <= 0) {
-    errno = ENOENT;
-    return ACL_ERROR;
-  }
-
-  struct stat s;
-  int result = fstat(fd, &s);
-
-  if (result == 0) {
-    return s.st_mode;
-  }
-  else {
-    /* errno will be set already by lstat() */
-    return result;
-  }
-}
-
-
-
-/**
- * @brief Determine if the given file descriptor might refer to an
- *   (unsafe) hard link.
- *
- * @param fd
- *   The file descriptor whose link count we want to investigate.
- *
- * @return true if we are certain that @c fd does not describe a hard
- *   link, and false otherwise. In case of error, false is returned,
- *   because we are not sure that @c fd is not a hard link.
- */
-bool is_hardlink_safe(int fd) {
-  if (fd <= 0) {
-    return false;
-  }
-  struct stat s;
-  int result = fstat(fd, &s);
-  if (result == 0) {
-    return (s.st_nlink == 1 || S_ISDIR(s.st_mode));
-  }
-  else {
-    return false;
-  }
-}
-
-
-/**
- * @brief Determine whether or not the given file descriptor is for
- *   a regular file.
- *
- * @param fd
- *   The file descriptor to test for regular-fileness.
- *
- * @return true if @c fd describes a regular file, and false otherwise.
- */
-bool is_regular_file(int fd) {
-  if (fd <= 0) {
-    return false;
-  }
-
-  struct stat s;
-  int result = fstat(fd, &s);
-  if (result == 0) {
-    return S_ISREG(s.st_mode);
-  }
-  else {
-    return false;
-  }
-}
-
-
 
 /**
  * @brief Determine whether or not the given path is accessible.
@@ -140,9 +59,7 @@ bool path_accessible(const char* path) {
 
   /* If the path is relative, interpret it relative to the current
      working directory (just like the access() system call). */
-  int result = faccessat(AT_FDCWD, path, F_OK, flags);
-
-  if (result == 0) {
+  if (faccessat(AT_FDCWD, path, F_OK, flags) == 0) {
     return true;
   }
   else {
@@ -166,8 +83,7 @@ bool is_path_directory(const char* path) {
   }
 
   struct stat s;
-  int result = lstat(path, &s);
-  if (result == 0) {
+  if (lstat(path, &s) == 0) {
     return S_ISDIR(s.st_mode);
   }
   else {
@@ -176,30 +92,6 @@ bool is_path_directory(const char* path) {
 }
 
 
-/**
- * @brief Determine whether or not the given file descriptor is for
- *   a directory.
- *
- * @param fd
- *   The file descriptor whose directoryness is in question.
- *
- * @return true if @c fd describes a directory, and false otherwise.
- */
-bool is_directory(int fd) {
-  if (fd <= 0) {
-    return false;
-  }
-
-  struct stat s;
-  int result = fstat(fd, &s);
-  if (result == 0) {
-    return S_ISDIR(s.st_mode);
-  }
-  else {
-    return false;
-  }
-}
-
 
 
 /**
@@ -226,19 +118,16 @@ bool is_directory(int fd) {
  *   returned. Otherwise, @c ACL_SUCCESS.
  *
  */
-int acl_set_entry(acl_t* aclp,
-		  acl_entry_t entry) {
+int acl_set_entry(acl_t* aclp, acl_entry_t entry) {
 
   acl_tag_t entry_tag;
-  int gt_result = acl_get_tag_type(entry, &entry_tag);
-  if (gt_result == ACL_ERROR) {
+  if (acl_get_tag_type(entry, &entry_tag) == ACL_ERROR) {
     perror("acl_set_entry (acl_get_tag_type)");
     return ACL_ERROR;
   }
 
   acl_permset_t entry_permset;
-  int ps_result = acl_get_permset(entry, &entry_permset);
-  if (ps_result == ACL_ERROR) {
+  if (acl_get_permset(entry, &entry_permset) == ACL_ERROR) {
     perror("acl_set_entry (acl_get_permset)");
     return ACL_ERROR;
   }
@@ -249,9 +138,8 @@ int acl_set_entry(acl_t* aclp,
 
   while (result == ACL_SUCCESS) {
     acl_tag_t existing_tag = ACL_UNDEFINED_TAG;
-    int tag_result = acl_get_tag_type(existing_entry, &existing_tag);
 
-    if (tag_result == ACL_ERROR) {
+    if (acl_get_tag_type(existing_entry, &existing_tag) == ACL_ERROR) {
        perror("set_acl_tag_permset (acl_get_tag_type)");
        return ACL_ERROR;
     }
@@ -265,14 +153,12 @@ int acl_set_entry(acl_t* aclp,
 	   match one of them, we're allowed to return ACL_SUCCESS
 	   below and bypass the rest of the function. */
 	acl_permset_t existing_permset;
-	int gep_result = acl_get_permset(existing_entry, &existing_permset);
-	if (gep_result == ACL_ERROR) {
+	if (acl_get_permset(existing_entry, &existing_permset) == ACL_ERROR) {
 	  perror("acl_set_entry (acl_get_permset)");
 	  return ACL_ERROR;
 	}
 
-	int s_result = acl_set_permset(existing_entry, entry_permset);
-	if (s_result == ACL_ERROR) {
+	if (acl_set_permset(existing_entry, entry_permset) == ACL_ERROR) {
 	  perror("acl_set_entry (acl_set_permset)");
 	  return ACL_ERROR;
 	}
@@ -303,20 +189,17 @@ int acl_set_entry(acl_t* aclp,
    * be fed to acl_free(). In other words, we should still be freeing
    * the right thing, even if the value pointed to by aclp changes.
    */
-  int c_result = acl_create_entry(aclp, &new_entry);
-  if (c_result == ACL_ERROR) {
+  if (acl_create_entry(aclp, &new_entry) == ACL_ERROR) {
     perror("acl_set_entry (acl_create_entry)");
     return ACL_ERROR;
   }
 
-  int st_result = acl_set_tag_type(new_entry, entry_tag);
-  if (st_result == ACL_ERROR) {
+  if (acl_set_tag_type(new_entry, entry_tag) == ACL_ERROR) {
     perror("acl_set_entry (acl_set_tag_type)");
     return ACL_ERROR;
   }
 
-  int s_result = acl_set_permset(new_entry, entry_permset);
-  if (s_result == ACL_ERROR) {
+  if (acl_set_permset(new_entry, entry_permset) == ACL_ERROR) {
     perror("acl_set_entry (acl_set_permset)");
     return ACL_ERROR;
   }
@@ -329,8 +212,7 @@ int acl_set_entry(acl_t* aclp,
       return ACL_ERROR;
     }
 
-    int sq_result = acl_set_qualifier(new_entry, entry_qual);
-    if (sq_result == ACL_ERROR) {
+    if (acl_set_qualifier(new_entry, entry_qual) == ACL_ERROR) {
       perror("acl_set_entry (acl_set_qualifier)");
       return ACL_ERROR;
     }
@@ -421,9 +303,8 @@ int acl_execute_masked(acl_t acl) {
 
   while (ge_result == ACL_SUCCESS) {
     acl_tag_t tag = ACL_UNDEFINED_TAG;
-    int tag_result = acl_get_tag_type(entry, &tag);
 
-    if (tag_result == ACL_ERROR) {
+    if (acl_get_tag_type(entry, &tag) == ACL_ERROR) {
        perror("acl_execute_masked (acl_get_tag_type)");
        return ACL_ERROR;
     }
@@ -433,8 +314,7 @@ int acl_execute_masked(acl_t acl) {
 	 execute is specified. */
       acl_permset_t permset;
 
-      int ps_result = acl_get_permset(entry, &permset);
-      if (ps_result == ACL_ERROR) {
+      if (acl_get_permset(entry, &permset) == ACL_ERROR) {
 	perror("acl_execute_masked (acl_get_permset)");
 	return ACL_ERROR;
       }
@@ -460,38 +340,27 @@ int acl_execute_masked(acl_t acl) {
 
 
 /**
- * @brief Determine whether @c fd is executable (by anyone) or a
- *   directory.
+ * @brief Determine whether @c fd is executable by anyone.
+ *
  *
  * This is used as part of the heuristic to determine whether or not
  * we should mask the execute bit when inheriting an ACL. If @c fd
- * describes a directory, the answer is a clear-cut yes. This behavior
- * is modeled after the capital 'X' perms of setfacl.
- *
- * If @c fd describes a file, we check the @a effective permissions,
- * contrary to what setfacl does.
+ * describes a file, we check the @a effective permissions, contrary
+ * to what setfacl does.
  *
  * @param fd
  *   The file descriptor to check.
  *
  * @return
- *   - @c ACL_SUCCESS - @c fd describes a directory, or someone has effective
-       execute permissions.
- *   - @c ACL_FAILURE - @c fd describes a regular file and nobody can execute
-       it.
+ *   - @c ACL_SUCCESS - Someone has effective execute permissions on @c fd.
+ *   - @c ACL_FAILURE - Nobody can execute @c fd.
  *   - @c ACL_ERROR - Unexpected library error.
  */
-int any_can_execute_or_dir(int fd) {
-
-  if (is_directory(fd)) {
-    /* That was easy... */
-    return ACL_SUCCESS;
-  }
-
+int any_can_execute(int fd) {
   acl_t acl = acl_get_fd(fd);
 
   if (acl == (acl_t)NULL) {
-    perror("any_can_execute_or_dir (acl_get_file)");
+    perror("any_can_execute (acl_get_file)");
     return ACL_ERROR;
   }
 
@@ -499,8 +368,13 @@ int any_can_execute_or_dir(int fd) {
   int result = ACL_FAILURE;
 
   if (acl_is_minimal(acl)) {
-    mode_t mode = get_mode(fd);
-    if (mode & (S_IXUSR | S_IXOTH | S_IXGRP)) {
+    struct stat s;
+    if (fstat(fd, &s) == -1) {
+      perror("any_can_execute (fstat)");
+      result = ACL_ERROR;
+      goto cleanup;
+    }
+    if (s.st_mode & (S_IXUSR | S_IXOTH | S_IXGRP)) {
       result = ACL_SUCCESS;
       goto cleanup;
     }
@@ -517,10 +391,9 @@ int any_can_execute_or_dir(int fd) {
     /* The first thing we do is check to see if this is a mask
        entry. If it is, we skip it entirely. */
     acl_tag_t tag = ACL_UNDEFINED_TAG;
-    int tag_result = acl_get_tag_type(entry, &tag);
 
-    if (tag_result == ACL_ERROR) {
-      perror("any_can_execute_or_dir (acl_get_tag_type)");
+    if (acl_get_tag_type(entry, &tag) == ACL_ERROR) {
+      perror("any_can_execute_or (acl_get_tag_type)");
       result = ACL_ERROR;
       goto cleanup;
     }
@@ -533,16 +406,15 @@ int any_can_execute_or_dir(int fd) {
     /* Ok, so it's not a mask entry. Check the execute perms. */
     acl_permset_t permset;
 
-    int ps_result = acl_get_permset(entry, &permset);
-    if (ps_result == ACL_ERROR) {
-      perror("any_can_execute_or_dir (acl_get_permset)");
+    if (acl_get_permset(entry, &permset) == ACL_ERROR) {
+      perror("any_can_execute_or (acl_get_permset)");
       result = ACL_ERROR;
       goto cleanup;
     }
 
     int gp_result = acl_get_perm(permset, ACL_EXECUTE);
     if (gp_result == ACL_ERROR) {
-      perror("any_can_execute_or_dir (acl_get_perm)");
+      perror("any_can_execute (acl_get_perm)");
       result = ACL_ERROR;
       goto cleanup;
     }
@@ -559,7 +431,7 @@ int any_can_execute_or_dir(int fd) {
   }
 
   if (ge_result == ACL_ERROR) {
-    perror("any_can_execute_or_dir (acl_get_entry)");
+    perror("any_can_execute (acl_get_entry)");
     result = ACL_ERROR;
     goto cleanup;
   }
@@ -592,7 +464,8 @@ int any_can_execute_or_dir(int fd) {
 int assign_default_acl(const char* path, acl_t acl) {
 
   if (path == NULL) {
-    errno = ENOENT;
+    errno = EINVAL;
+    perror("assign_default_acl (args)");
     return ACL_ERROR;
   }
 
@@ -609,8 +482,7 @@ int assign_default_acl(const char* path, acl_t acl) {
     return ACL_ERROR; /* Nothing to clean up in this case. */
   }
 
-  int sf_result = acl_set_file(path, ACL_TYPE_DEFAULT, path_acl);
-  if (sf_result == ACL_ERROR) {
+  if (acl_set_file(path, ACL_TYPE_DEFAULT, path_acl) == ACL_ERROR) {
     perror("assign_default_acl (acl_set_file)");
     result = ACL_ERROR;
   }
@@ -662,6 +534,10 @@ int wipe_acls(int fd) {
  * @param path
  *   The path whose ACL we would like to reset to its default.
  *
+ * @param sp
+ *   A pointer to a stat structure for @c path, or @c NULL if you don't
+ *   have one handy.
+ *
  * @param no_exec_mask
  *   The value (either true or false) of the --no-exec-mask flag.
  *
@@ -671,10 +547,13 @@ int wipe_acls(int fd) {
  *     or the parent of @c path is not a directory.
  *   - @c ACL_ERROR - Unexpected library error.
  */
-int apply_default_acl(const char* path, bool no_exec_mask) {
+int apply_default_acl(const char* path,
+		      const struct stat* sp,
+		      bool no_exec_mask) {
 
   if (path == NULL) {
-    errno = ENOENT;
+    errno = EINVAL;
+    perror("apply_default_acl (args)");
     return ACL_ERROR;
   }
 
@@ -722,27 +601,42 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
    * race condition here, but the window is as small as possible
    * between when we open the file descriptor (look above) and when we
    * fstat it.
+   *
+   * Note: we only need to call fstat ourselves if we weren't passed a
+   * valid pointer to a stat structure (nftw does that).
   */
-  if (!is_hardlink_safe(fd)) {
-    result = ACL_FAILURE;
-    goto cleanup;
+  if (sp == NULL) {
+    struct stat s;
+    if (fstat(fd, &s) == -1) {
+      perror("apply_default_acl (fstat)");
+      goto cleanup;
+    }
+
+    sp = &s;
   }
 
-  if (!is_regular_file(fd) && !is_directory(fd)) {
-    result = ACL_FAILURE;
-    goto cleanup;
+  if (!S_ISDIR(sp->st_mode)) {
+    /* If it's not a directory, make sure it's a regular,
+       non-hard-linked file. */
+    if (!S_ISREG(sp->st_mode) || sp->st_nlink != 1) {
+      result = ACL_FAILURE;
+      goto cleanup;
+    }
   }
 
+
   /* Default to not masking the exec bit; i.e. applying the default
      ACL literally. If --no-exec-mask was not specified, then we try
-     to "guess" whether or not to mask the exec bit. */
+     to "guess" whether or not to mask the exec bit. This behavior
+     is modeled after the capital 'X' perms of setfacl. */
   bool allow_exec = true;
 
   if (!no_exec_mask) {
-    int ace_result = any_can_execute_or_dir(fd);
+    /* Never mask the execute bit on directories. */
+    int ace_result = any_can_execute(fd) || S_ISDIR(sp->st_mode);
 
     if (ace_result == ACL_ERROR) {
-      perror("apply_default_acl (any_can_execute_or_dir)");
+      perror("apply_default_acl (any_can_execute)");
       result = ACL_ERROR;
       goto cleanup;
     }
@@ -758,8 +652,7 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
     goto cleanup;
   }
 
-  int wipe_result = wipe_acls(fd);
-  if (wipe_result == ACL_ERROR) {
+  if (wipe_acls(fd) == ACL_ERROR) {
     perror("apply_default_acl (wipe_acls)");
     result = ACL_ERROR;
     goto cleanup;
@@ -775,8 +668,7 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
   }
 
   /* If it's a directory, inherit the parent's default. */
-  int inherit_result = assign_default_acl(path, defacl);
-  if (inherit_result == ACL_ERROR) {
+  if (assign_default_acl(path, defacl) == ACL_ERROR) {
     perror("apply_default_acl (assign_default_acl)");
     result = ACL_ERROR;
     goto cleanup;
@@ -787,9 +679,8 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
 
   while (ge_result == ACL_SUCCESS) {
     acl_tag_t tag = ACL_UNDEFINED_TAG;
-    int tag_result = acl_get_tag_type(entry, &tag);
 
-    if (tag_result == ACL_ERROR) {
+    if (acl_get_tag_type(entry, &tag) == ACL_ERROR) {
        perror("apply_default_acl (acl_get_tag_type)");
        result = ACL_ERROR;
        goto cleanup;
@@ -798,8 +689,7 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
 
     /* We've got an entry/tag from the default ACL. Get its permset. */
     acl_permset_t permset;
-    int ps_result = acl_get_permset(entry, &permset);
-    if (ps_result == ACL_ERROR) {
+    if (acl_get_permset(entry, &permset) == ACL_ERROR) {
       perror("apply_default_acl (acl_get_permset)");
       result = ACL_ERROR;
       goto cleanup;
@@ -815,15 +705,13 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
 	/* The mask doesn't affect acl_user_obj, acl_group_obj (in
 	   minimal ACLs) or acl_other entries, so if execute should be
 	   masked, we have to do it manually. */
-	int d_result = acl_delete_perm(permset, ACL_EXECUTE);
-	if (d_result == ACL_ERROR) {
+	if (acl_delete_perm(permset, ACL_EXECUTE) == ACL_ERROR) {
 	  perror("apply_default_acl (acl_delete_perm)");
 	  result = ACL_ERROR;
 	  goto cleanup;
 	}
 
-	int sp_result = acl_set_permset(entry, permset);
-	if (sp_result == ACL_ERROR) {
+	if (acl_set_permset(entry, permset) == ACL_ERROR) {
 	  perror("apply_default_acl (acl_set_permset)");
 	  result = ACL_ERROR;
 	  goto cleanup;
@@ -847,8 +735,7 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
      * called right here, we need acl_create_entry() to update the
      * value of "acl". To do that, it needs the address of "acl".
      */
-    int set_result = acl_set_entry(&acl, entry);
-    if (set_result == ACL_ERROR) {
+    if (acl_set_entry(&acl, entry) == ACL_ERROR) {
       perror("apply_default_acl (acl_set_entry)");
       result = ACL_ERROR;
       goto cleanup;
@@ -865,8 +752,7 @@ int apply_default_acl(const char* path, bool no_exec_mask) {
     goto cleanup;
   }
 
-  int sf_result = acl_set_fd(fd, acl);
-  if (sf_result == ACL_ERROR) {
+  if (acl_set_fd(fd, acl) == ACL_ERROR) {
     perror("apply_default_acl (acl_set_fd)");
     result = ACL_ERROR;
     goto cleanup;
@@ -919,12 +805,11 @@ void usage(const char* program_name) {
  *
  */
 int apply_default_acl_nftw(const char *target,
-			   const struct stat *s,
+			   const struct stat *sp,
 			   int info,
 			   struct FTW *ftw) {
 
-  bool app_result = apply_default_acl(target, false);
-  if (app_result) {
+  if (apply_default_acl(target, sp, false)) {
     return FTW_CONTINUE;
   }
   else {
@@ -942,12 +827,11 @@ int apply_default_acl_nftw(const char *target,
  *
  */
 int apply_default_acl_nftw_x(const char *target,
-			     const struct stat *s,
+			     const struct stat *sp,
 			     int info,
 			     struct FTW *ftw) {
 
-  bool app_result = apply_default_acl(target, true);
-  if (app_result) {
+  if (apply_default_acl(target, sp, true)) {
     return FTW_CONTINUE;
   }
   else {
@@ -984,7 +868,7 @@ int apply_default_acl_nftw_x(const char *target,
 bool apply_default_acl_recursive(const char *target, bool no_exec_mask) {
 
   if (!is_path_directory(target)) {
-    return apply_default_acl(target, no_exec_mask);
+    return apply_default_acl(target, NULL, no_exec_mask);
   }
 
   int max_levels = 256;
@@ -1086,7 +970,7 @@ int main(int argc, char* argv[]) {
     }
     else {
       /* It's either a normal file, or we're not operating recursively. */
-      reapp_result = apply_default_acl(target, no_exec_mask);
+      reapp_result = apply_default_acl(target, NULL, no_exec_mask);
     }
 
     if (!reapp_result) {