passt: Address new clang-tidy warnings from LLVM 13.0.1

clang-tidy from LLVM 13.0.1 reports some new warnings from these
checkers:

- altera-unroll-loops, altera-id-dependent-backward-branch: ignore
  for the moment being, add a TODO item

- bugprone-easily-swappable-parameters: ignore, nothing to do about
  those

- readability-function-cognitive-complexity: ignore for the moment
  being, add a TODO item

- altera-struct-pack-align: ignore, alignment is forced in protocol
  headers

- concurrency-mt-unsafe: ignore for the moment being, add a TODO
  item

Fix bugprone-implicit-widening-of-multiplication-result warnings,
though, that's doable and they seem to make sense.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/dhcp.c b/dhcp.c
index 0d6d698..a052397 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -271,10 +271,10 @@ int dhcp(struct ctx *c, struct ethhdr *eh, size_t len)
 	if (len < sizeof(*eh) + sizeof(*iph))
 		return 0;
 
-	if (len < sizeof(*eh) + iph->ihl * 4 + sizeof(*uh))
+	if (len < sizeof(*eh) + (long)iph->ihl * 4 + sizeof(*uh))
 		return 0;
 
-	uh = (struct udphdr *)((char *)iph + iph->ihl * 4);
+	uh = (struct udphdr *)((char *)iph + (long)(iph->ihl * 4));
 	m = (struct msg *)(uh + 1);
 
 	if (uh->dest != htons(67))
@@ -283,7 +283,7 @@ int dhcp(struct ctx *c, struct ethhdr *eh, size_t len)
 	if (c->no_dhcp)
 		return 1;
 
-	mlen = len - sizeof(*eh) - iph->ihl * 4 - sizeof(*uh);
+	mlen = len - sizeof(*eh) - (long)iph->ihl * 4 - sizeof(*uh);
 	if (mlen != ntohs(uh->len) - sizeof(*uh) ||
 	    mlen < offsetof(struct msg, o) ||
 	    m->op != BOOTREQUEST)
@@ -349,7 +349,7 @@ int dhcp(struct ctx *c, struct ethhdr *eh, size_t len)
 	iph->daddr = c->addr4;
 	iph->saddr = c->gw4;
 	iph->check = 0;
-	iph->check = csum_unaligned(iph, iph->ihl * 4, 0);
+	iph->check = csum_unaligned(iph, (intptr_t)(iph->ihl * 4), 0);
 
 	len += sizeof(*eh);
 	memcpy(eh->h_dest, eh->h_source, ETH_ALEN);