On Mon, Oct 28, 2024 at 06:07:14PM +0000, Daniel P. Berrangé wrote: > On Mon, Oct 28, 2024 at 10:32:55AM -0700, Andrea Bolognani wrote: > > I did some testing of my own and I can confirm that FreeBSD and > > OpenBSD are fine with this change, as are various Linux flavors > > (Alpine, CirrOS, Debian, Fedora, openSUSE, Ubuntu). > > > > However, a few other operating systems aren't: namely GNU/Hurd, Haiku > > and NetBSD break with this change. Interestingly, these were all fine > > with the nftables backend before it. > > Well that's odd. I've checked NetBSD source code and found no less > than 3 DHCP client impls, and all of them cope with checksum == 0. > > https://github.com/NetBSD/src/blob/trunk/usr.bin/rump_dhcpclient/net.c#L497 > > https://github.com/NetBSD/src/blob/trunk/external/bsd/dhcpcd/dist/src/dhcp.c#L3507 > > https://github.com/NetBSD/src/blob/trunk/external/mpl/dhcp/dist/common/packet.c#L373 > > the middle impl also directly copes with partial checksums The boot log contains Starting dhcpcd. wm0: checksum failure from 192.168.124.1 so I guess the second implementation is the relevant one. > Not identified the Hurd/Haiku DHCP client code yet... I'm using Debian GNU/Hurd, so the DHCP client is the same as regular Debian (ISC DHCP). The source can be found at https://deb.debian.org/debian-ports/pool-hurd-i386/main/i/isc-dhcp/ The version is a bit old and there's the tiniest amount of patching compared to the Linux build, specifically: --- isc-dhcp-4.4.3-P1-1.1/debian/patches/bind-fix 1970-01-01 01:00:00.000000000 +0100 +++ isc-dhcp-4.4.3-P1-1.1+hurd.1/debian/patches/bind-fix 2023-02-15 15:39:49.000000000 +0100 @@ -0,0 +1,26 @@ +Index: isc-dhcp-4.4.3-P1-build/bind/bind-9.11.36/lib/isc/unix/socket.c +=================================================================== +--- isc-dhcp-4.4.3-P1-build.orig/bind/bind-9.11.36/lib/isc/unix/socket.c ++++ isc-dhcp-4.4.3-P1-build/bind/bind-9.11.36/lib/isc/unix/socket.c +@@ -2633,7 +2633,7 @@ opensocket(isc__socketmgr_t *manager, is + char strbuf[ISC_STRERRORSIZE]; + const char *err = "socket"; + int tries = 0; +-#if defined(USE_CMSG) || defined(SO_BSDCOMPAT) || defined(SO_NOSIGPIPE) ++#if 1 + int on = 1; + #endif + #if defined(SO_RCVBUF) I'm not sure whether this could be relevant to the issue at hand. To clarify, this is something that needs to be handled at the userspace level, no kernel changes required? And clearly it affects DHCP, but what about other protocols? Are we confident those will cope just fine? -- Andrea Bolognani / Red Hat / Virtualization
