From: Todd C. Miller <Todd.Miller@courtesan.com>
Date: Thu, 12 Jan 2012 20:23:16 +0000 (-0500)
Subject: Allow "visudo -c" to work when we only have read-only access to the
X-Git-Tag: SUDO_1_7_9~31
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=36acde71acc91129c989609f003e306b63bdb6b0;p=sudo

Allow "visudo -c" to work when we only have read-only access to the
sudoers include files.

--HG--
branch : 1.7
---

diff --git a/visudo.c b/visudo.c
index e3f9b8cfd..f79b9ff11 100644
--- a/visudo.c
+++ b/visudo.c
@@ -136,6 +136,7 @@ struct sudo_user sudo_user;
 struct passwd *list_pw;
 static struct sudoersfile_list sudoerslist;
 static struct rbtree *alias_freelist;
+static int checkonly;
 
 int
 main(argc, argv)
@@ -144,7 +145,7 @@ main(argc, argv)
 {
     struct sudoersfile *sp;
     char *args, *editor, *sudoers_path;
-    int ch, checkonly, quiet, strict, oldperms;
+    int ch, quiet, strict, oldperms;
 #if defined(SUDO_DEVEL) && defined(__OpenBSD__)
     extern char *malloc_options;
     malloc_options = "AFGJPR";
@@ -828,6 +829,12 @@ open_sudoers(path, doedit, keepopen)
 {
     struct sudoersfile *entry;
     FILE *fp;
+    int open_flags;
+
+    if (checkonly)
+	open_flags = O_RDONLY;
+    else
+	open_flags = O_RDWR | O_CREAT;
 
     /* Check for existing entry */
     tq_foreach_fwd(&sudoerslist, entry) {
@@ -840,7 +847,7 @@ open_sudoers(path, doedit, keepopen)
 	entry->modified = 0;
 	entry->prev = entry;
 	entry->next = NULL;
-	entry->fd = open(entry->path, O_RDWR | O_CREAT, SUDOERS_MODE);
+	entry->fd = open(entry->path, open_flags, SUDOERS_MODE);
 	entry->tpath = NULL;
 	entry->doedit = doedit;
 	if (entry->fd == -1) {
@@ -848,7 +855,7 @@ open_sudoers(path, doedit, keepopen)
 	    efree(entry);
 	    return NULL;
 	}
-	if (!lock_file(entry->fd, SUDO_TLOCK))
+	if (!checkonly && !lock_file(entry->fd, SUDO_TLOCK))
 	    errorx(1, "%s busy, try again later", entry->path);
 	if ((fp = fdopen(entry->fd, "r")) == NULL)
 	    error(1, "%s", entry->path);