buffer: use nftnl_expr_snprintf() from nftnl_buf_expr()

This helper function deals with no ->snprintf() indirection in
expression and safe buffer nul-termination, use it.

Fixes: 059b9bf6fb31 ("src: Use nftnl_buf to export XML/JSON rules")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/buffer.c b/src/buffer.c
index f9d5a838c4ab65d7519bb3d77f4abb29c97b8625..9ec86af121c9d8786e605f97d0a5d7d3906f451e 100644 (file)
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -14,6 +14,7 @@
 #include <string.h>
 #include <buffer.h>
 #include <libnftnl/common.h>
+#include <libnftnl/expr.h>
 #include "internal.h"
 
 int nftnl_buf_update(struct nftnl_buf *b, int ret)
@@ -206,8 +207,8 @@ int nftnl_buf_expr(struct nftnl_buf *b, int type, uint32_t flags,
        case NFTNL_OUTPUT_JSON:
                nftnl_buf_put(b, "{");
                nftnl_buf_str(b, type, expr->ops->name, TYPE);
-               ret = expr->ops->snprintf(b->buf + b->off, b->len, type, flags,
-                                         expr);
+               ret = nftnl_expr_snprintf(b->buf + b->off, b->len, expr, type,
+                                         flags);
                if (ret > 0)
                        nftnl_buf_update(b, ret);
                else