From: cy Date: Tue, 6 Oct 2015 03:41:11 +0000 (+0000) Subject: On some interfaces, ipfilter drops UDP packets with zero checkum. X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=b09fc0c241c99f57ec17d3ca87519258b4a6dfee;p=people%2Fjulieng%2Ffreebsd.git On some interfaces, ipfilter drops UDP packets with zero checkum. This commit fixes that. PR: 166372 Submitted by: mk@neon1.net Reviewed by: Darren Reed MFC after: 1 week --- diff --git a/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c b/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c index 93ea5725d0bc..a5d3f44aea10 100644 --- a/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c +++ b/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c @@ -1104,6 +1104,22 @@ ipf_checkv4sum(fin) return -1; } if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) { + /* Depending on the driver, UDP may have zero checksum */ + if (fin->fin_p == IPPROTO_UDP && (fin->fin_flx & + (FI_FRAG|FI_SHORT|FI_BAD)) == 0) { + udphdr_t *udp = fin->fin_dp; + if (udp->uh_sum == 0) { + /* + * we're good no matter what the hardware + * checksum flags and csum_data say (handling + * of csum_data for zero UDP checksum is not + * consistent across all drivers) + */ + fin->fin_cksum = 1; + return 0; + } + } + if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) sum = m->m_pkthdr.csum_data; else