Added argv_x functions to buffer.[ch] to be used to safely build

up argv strings for execve without the possibility of truncation
or misinterpretation of mid-argument spacing.


git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@3107 e7ae566f-a301-0410-adde-c780ea21d3b5

1 files changed, 33 insertions, 0 deletions

diff --git a/buffer.h b/buffer.h
index 7de3363..3190229 100644
--- a/buffer.h
+++ b/buffer.h
@@ -56,6 +56,12 @@ struct buffer
 #endif
 };
 
+/* used by argv_x functions */
+struct argv {
+  size_t argc;
+  char **argv;
+};
+
 /* for garbage collection */
 
 struct gc_entry
@@ -222,6 +228,33 @@ int openvpn_snprintf(char *str, size_t size, const char *format, ...)
     ;
 
 /*
+ * A printf-like function (that only recognizes a subset of standard printf
+ * format operators) that prints arguments to an argv list instead
+ * of a standard string.  This is used to build up argv arrays for passing
+ * to execve.
+ */
+void argv_init (struct argv *a);
+void argv_reset (struct argv *a);
+size_t argv_argc (const char *format);
+char *argv_term (const char **f);
+const char *argv_str (const struct argv *a, struct gc_arena *gc, const unsigned int flags);
+
+#define APA_CAT (1<<0) /* concatentate onto existing struct argv list */
+void argv_printf_arglist (struct argv *a, const char *format, const unsigned int flags, va_list arglist);
+
+void argv_printf (struct argv *a, const char *format, ...)
+#ifdef __GNUC__
+  __attribute__ ((format (printf, 2, 3)))
+#endif
+  ;
+
+void argv_printf_cat (struct argv *a, const char *format, ...)
+#ifdef __GNUC__
+  __attribute__ ((format (printf, 2, 3)))
+#endif
+  ;
+
+/*
  * remove/add trailing characters
  */