Check EDITOR/VISUAL to make sure sudoedit is not re-invoking itself or sudo.

This allows one to set EDITOR to sudoedit without getting into an infinite
loop of sudoedit running itself until the path gets too big.

diff --git a/sudo_edit.c b/sudo_edit.c
index 8548d7a50525f858e2559eef4a3fc8cf724952a7..29bc4cf29dbb63130a88d82d97c43238e89883d6 100644 (file)
--- a/sudo_edit.c
+++ b/sudo_edit.c
@@ -62,10 +62,13 @@ __unused static const char rcsid[] = "$Sudo$";
 extern sigaction_t saved_sa_int, saved_sa_quit, saved_sa_tstp;
 extern char **environ;
 
+static char *find_editor();
+
 /*
  * Wrapper to allow users to edit privileged files with their own uid.
  */
-int sudo_edit(argc, argv, envp)
+int
+sudo_edit(argc, argv, envp)
     int argc;
     char **argv;
     char **envp;
@@ -189,20 +192,8 @@ int sudo_edit(argc, argv, envp)
     if (argc == 1)
        return(1);                      /* no files readable, you lose */
 
-    /*
-     * Determine which editor to use.  We don't bother restricting this
-     * based on def_env_editor or def_editor since the editor runs with
-     * the uid of the invoking user, not the runas (privileged) user.
-     */
     environ = envp;
-    if (((editor = getenv("VISUAL")) != NULL && *editor != '\0') ||
-       ((editor = getenv("EDITOR")) != NULL && *editor != '\0')) {
-       editor = estrdup(editor);
-    } else {
-       editor = estrdup(def_editor);
-       if ((cp = strchr(editor, ':')) != NULL)
-           *cp = '\0';                 /* def_editor could be a path */
-    }
+    editor = find_editor();
 
     /*
      * Allocate space for the new argument vector and fill it in.
@@ -358,3 +349,39 @@ cleanup:
     }
     return(1);
 }
+
+/*
+ * Determine which editor to use.  We don't bother restricting this
+ * based on def_env_editor or def_editor since the editor runs with
+ * the uid of the invoking user, not the runas (privileged) user.
+ */
+static char *
+find_editor()
+{
+    char *cp, *editor = NULL, **ev, *ev0[3];
+
+    ev0[0] = "VISUAL";
+    ev0[1] = "EDITOR";
+    ev0[2] = NULL;
+    for (ev = ev0; *ev != NULL; ev++) {
+       if ((editor = getenv(*ev)) != NULL && *editor != '\0') {
+           if ((cp = strrchr(editor, '/')) != NULL)
+               cp++;
+           else
+               cp = editor;
+           /* Ignore "sudoedit" and "sudo" to avoid an endless loop. */
+           if (strncmp(cp, "sudo", 4) != 0 ||
+               (cp[4] != ' ' && cp[4] != '\0' && strcmp(cp + 4, "edit") != 0)) {
+               editor = estrdup(editor);
+               break;
+           }
+       }
+       editor = NULL;
+    }
+    if (editor == NULL) {
+       editor = estrdup(def_editor);
+       if ((cp = strchr(editor, ':')) != NULL)
+           *cp = '\0';                 /* def_editor could be a path */
+    }
+    return(editor);
+}