[PATCH 3/4] ndp: Fix Clang analyzer warning (clang-analyzer-security.PointerSub)

Addresses Clang warning: "Subtraction of two pointers that do not point into the same array is undefined behavior" for the line: `ndp_send(c, dst, &ra, ptr - (unsigned char *)&ra);` Here, `ptr` is `&ra.var[0]`. The subtraction calculates the offset of `var[0]` within the `struct ra_options ra`. Since `ptr` points inside `ra`, this pointer arithmetic is well-defined for calculating the size of the data to send, even if `ptr` and `&ra` are not strictly considered part of the same "array" by the analyzer. Signed-off-by: Laurent Vivier --- ndp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/ndp.c b/ndp.c index ded2081ddd1d..b664034b00b1 100644 --- a/ndp.c +++ b/ndp.c @@ -328,6 +328,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst) memcpy(&ra.source_ll.mac, c->our_tap_mac, ETH_ALEN); + /* NOLINTNEXTLINE(clang-analyzer-security.PointerSub) */ ndp_send(c, dst, &ra, ptr - (unsigned char *)&ra); } -- 2.49.0