Use UDP len when calculating UDP checksums
The length of the IP payload is normally equal to the UDP length, UDP Options (draft-ietf-tsvwg-udp-options-02) suggests using the difference between IP length and UDP length to create space for trailing data. Correct checksum length calculation to use the UDP length rather than the IP length when not offloading UDP checksums. Approved by: jtl (mentor) Differential Revision: https://reviews.freebsd.org/D15222
This commit is contained in:
parent
bca1b45bb1
commit
1fdbfb909f
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=334705
@ -80,6 +80,10 @@ __FBSDID("$FreeBSD$");
|
||||
#include <netinet/in_var.h>
|
||||
#include <netinet/ip_var.h>
|
||||
#include <netinet/ip_options.h>
|
||||
|
||||
#include <netinet/udp.h>
|
||||
#include <netinet/udp_var.h>
|
||||
|
||||
#ifdef SCTP
|
||||
#include <netinet/sctp.h>
|
||||
#include <netinet/sctp_crc32.h>
|
||||
@ -920,14 +924,28 @@ void
|
||||
in_delayed_cksum(struct mbuf *m)
|
||||
{
|
||||
struct ip *ip;
|
||||
uint16_t csum, offset, ip_len;
|
||||
struct udphdr *uh;
|
||||
uint16_t cklen, csum, offset;
|
||||
|
||||
ip = mtod(m, struct ip *);
|
||||
offset = ip->ip_hl << 2 ;
|
||||
ip_len = ntohs(ip->ip_len);
|
||||
csum = in_cksum_skip(m, ip_len, offset);
|
||||
if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
|
||||
csum = 0xffff;
|
||||
|
||||
if (m->m_pkthdr.csum_flags & CSUM_UDP) {
|
||||
/* if udp header is not in the first mbuf copy udplen */
|
||||
if (offset + sizeof(struct udphdr) > m->m_len)
|
||||
m_copydata(m, offset + offsetof(struct udphdr, uh_ulen),
|
||||
2, (caddr_t)&cklen);
|
||||
else {
|
||||
uh = (struct udphdr *)((caddr_t)ip + offset);
|
||||
cklen = ntohs(uh->uh_ulen);
|
||||
}
|
||||
csum = in_cksum_skip(m, cklen + offset, offset);
|
||||
if (csum == 0)
|
||||
csum = 0xffff;
|
||||
} else {
|
||||
cklen = ntohs(ip->ip_len);
|
||||
csum = in_cksum_skip(m, cklen, offset);
|
||||
}
|
||||
offset += m->m_pkthdr.csum_data; /* checksum offset */
|
||||
|
||||
/* find the mbuf in the chain where the checksum starts*/
|
||||
|
Loading…
Reference in New Issue
Block a user