exhtdr: pacify compiler warning

gcc 7.1.1 complains:

exthdr.c:41:31: warning: ‘%d’ directive output may be truncated writing between 1 and 8 bytes into a region of size 3 [-Wformat-truncation=]
    snprintf(buf, sizeof buf, "%d", offset);
                               ^~
This warning is incorrect, as offset is limited by tcp option ranges,
but gcc doesn't know this. Increase buffer to avoid the warning.

Signed-off-by: Florian Westphal <fw@strlen.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/exthdr.c b/src/exthdr.c
index a678115b..a412025c 100644
--- a/src/exthdr.c
+++ b/src/exthdr.c
@@ -30,7 +30,7 @@ static void exthdr_expr_print(const struct expr *expr, struct output_ctx *octx)
 		 * multiplicator
 		 */
 		unsigned int offset = expr->exthdr.offset / 64;
-		char buf[3] = {0};
+		char buf[9] = {0};
 
 		if (expr->exthdr.flags & NFT_EXTHDR_F_PRESENT) {
 			printf("tcp option %s", expr->exthdr.desc->name);