susmb

commit 64313aed26f8c03e48d817d01affe47eb2df5a1e
parent fdd9015111ff8fcb39d85d25250d14b1d532e44f
Author: Geoff Johnstone <qwerty@acm.org>
Date:   Sat, 13 Mar 2010 13:29:26 +0000

Don't truncate silently in snprintf().

Diffstat:
M
conffile.c
 | 
9
++++++---
M
usmb.c
 | 
25
++++++++++++++++++++++---
M
utils.c
 | 
31
++++++++++++++++++++++++++++++-
M
utils.h
 | 
7
+++++++

4 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/conffile.c b/conffile.c
@@ -111,8 +111,11 @@ static bool do_xpath_text (xmlXPathContextPtr ctx,
                            const char *child, char **out)
 {
   char xpath[2048];
-  snprintf (xpath, sizeof (xpath),
-            "/usmbconfig/%s[@id='%s']/%s/text()", parent, id, child);
+
+  if (!bsnprintf (xpath, sizeof (xpath),
+                  "/usmbconfig/%s[@id='%s']/%s/text()", parent, id, child))
+    return false;
+
   return xml_xpath_text (ctx, xpath, (void *)out);
 }
 
@@ -146,7 +149,7 @@ bool conffile_get_mount (const char *filename, const char *key,
     if (!do_xpath_text (ctx, "mount", key, "mountpoint", mountpoint)) break;
     (void)do_xpath_text (ctx, "mount", key, "options", options);
 
-    snprintf (xp, sizeof (xp), "/usmbconfig/mount[@id='%s']", key);
+    if (!snprintf (xp, sizeof (xp), "/usmbconfig/mount[@id='%s']", key)) break;
     if (!xml_xpath_attr_value (ctx, xp, "credentials", &creds)) break;
 
     (void)do_xpath_text (ctx, "credentials", creds, "domain", domain);
diff --git a/usmb.c b/usmb.c
@@ -21,6 +21,7 @@
 #include "samba3x-compat.h"
 #include <fuse.h>
 #include <assert.h>
+#include <limits.h>
 #include <errno.h>
 #include <stdarg.h>
 #include <stdbool.h>
@@ -190,7 +191,13 @@ static bool create_share_name (const char *server_, const char *sharename)
     return false;
   }
 
-  snprintf (share, len, "smb://%s/%s", server_, sharename);
+  if (!bsnprintf (share, len, "smb://%s/%s", server_, sharename))
+  {
+    fputs ("Share server and/or name are too long.\n", stderr);
+    free (share);
+    return false;
+  }
+
   DEBUG (fprintf (stderr, "Share URL: %s\n", share));
   return true;
 }
@@ -276,8 +283,20 @@ int main (int argc, char **argv)
   }
 
   {
-    static char conf[256];
-    snprintf (conf, sizeof (conf), "%s/.usmb.conf", getenv ("HOME"));
+    static char conf[PATH_MAX];
+    const char * const HOME = getenv ("HOME");
+    if (NULL == HOME)
+    {
+      fputs ("Please set the HOME environment variable.\n", stderr);
+      return EXIT_FAILURE;
+    }
+
+    if (!bsnprintf (conf, sizeof (conf), "%s/.usmb.conf", HOME))
+    {
+      fputs ("Configuration file path is too long.\n", stderr);
+      return EXIT_FAILURE;
+    }
+
     conffile = conf;
   }
 
diff --git a/utils.c b/utils.c
@@ -1,5 +1,5 @@
 /* usmb - mount SMB shares via FUSE and Samba
- * Copyright (C) 2006-2009 Geoff Johnstone
+ * Copyright (C) 2006-2010 Geoff Johnstone
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
@@ -140,3 +140,32 @@ void xfree_errno (const void *ptr)
   errno = err;
 }
 
+
+bool bsnprintf (char *str, size_t size, const char *format, ...)
+{
+  va_list ap;
+  bool ret;
+
+  assert (str);
+  assert (format);
+
+  va_start (ap, format);
+  ret = bvsnprintf (str, size, format, ap);
+  va_end (ap);
+
+  return ret;
+}
+
+
+bool bvsnprintf (char *str, size_t size, const char *format, va_list ap)
+{
+  int ret;
+
+  assert (str);
+  assert (format);
+
+  ret = vsnprintf (str, size, format, ap);
+
+  return ((ret >= 0) && ((size_t)ret < size));
+}
+
diff --git a/utils.h b/utils.h
@@ -17,6 +17,10 @@
 #ifndef UTILS_H
   #define UTILS_H
 
+  #include <stdarg.h>
+  #include <stdbool.h>
+  #include <stddef.h>
+
   #ifdef DEBUG
     #undef DEBUG
     #define DEBUG(x) (x)
@@ -31,5 +35,8 @@
   void clear_and_free (char *ptr);
   void free_errno (const void *ptr);
   void xfree_errno (const void *ptr);
+  bool bsnprintf (char *str, size_t size, const char *format, ...)
+    __attribute__ ((format (printf, 3, 4)));
+  bool bvsnprintf (char *str, size_t size, const char *format, va_list ap);
 
 #endif