In article <20060320154314.830FB2DA27@cvs.netbsd.org>,
Matthias Drochner  <drochner@netbsd.org> wrote:
>
>Module Name:	src
>Committed By:	drochner
>Date:		Mon Mar 20 15:43:14 UTC 2006
>
>Modified Files:
>	src/lib/libpcap: gencode.c
>
>Log Message:
>revert wrong fix to a non-existant problem
>
>Don't believe Coverity blindly!
>
Which part don't you believe:

	struct in6_addr mask;

	if (sizeof(mask) * 8 < masklen)
		bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8));
	memset(&mask, 0, sizeof(mask));
	memset(&mask, 0xff, masklen / 8);
	if (masklen % 8) {
		mask.s6_addr[masklen / 8] =
			(0xff << (8 - masklen % 8)) & 0xff;
	}

-----
	sizeof(mask) == 16
	/* assume the maximum possible maxlen without calling bpf_error */
	masklen == 128 = (16 * 8)

	mask.s6_addr[masklen / 8] = mask.s6_addr[16] = oops, since in6_addr:

	struct in6_addr {
		union {
			__uint8_t   __u6_addr8[16];
			__uint16_t  __u6_addr16[8];
			uint32_t  __u6_addr32[4];
		} __u6_addr;			/* 128-bit IP6 address */
	};

#define s6_addr   __u6_addr.__u6_addr8

-----

Perhaps the proper fix is:

	if (masklen < sizeof(mask) * 8)
		bpf_error("mask length must be < %u", (unsigned int)(sizeof(mask) * 8));

christos