From 914ac555cd40f9c09e655a737214bfb7de21b8d9 Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Wed, 15 Sep 2021 22:59:52 +0900 Subject: [PATCH] ether-addr-util: make hw_addr_to_string() return valid string even if hardware address is null Previously, when the length of the hardware address is zero, then the buffer was not nul-terminated. This also replaces sprintf() with hexchar(). --- src/basic/ether-addr-util.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/src/basic/ether-addr-util.c b/src/basic/ether-addr-util.c index e660ac2c6f..dc5b5b833d 100644 --- a/src/basic/ether-addr-util.c +++ b/src/basic/ether-addr-util.c @@ -7,6 +7,7 @@ #include #include "ether-addr-util.h" +#include "hexdecoct.h" #include "macro.h" #include "string-util.h" @@ -15,12 +16,13 @@ char* hw_addr_to_string(const struct hw_addr_data *addr, char buffer[HW_ADDR_TO_ assert(buffer); assert(addr->length <= HW_ADDR_MAX_SIZE); - for (size_t i = 0; i < addr->length; i++) { - sprintf(&buffer[3*i], "%02"PRIx8, addr->bytes[i]); - if (i < addr->length - 1) - buffer[3*i + 2] = ':'; + for (size_t i = 0, j = 0; i < addr->length; i++) { + buffer[j++] = hexchar(addr->bytes[i] >> 4); + buffer[j++] = hexchar(addr->bytes[i] & 0x0f); + buffer[j++] = ':'; } + buffer[addr->length > 0 ? addr->length * 3 - 1 : 0] = '\0'; return buffer; } -- 2.25.1