The checksum algorithm used by IPv4, TCP and UDP allows a zero value to be represented by either 0x0000 and 0xFFFF. But per RFC 768, a zero UDP checksum must be transmitted as 0xFFFF because 0x0000 is a special value meaning no checksum. Substitute 0xFFFF whenever a checksum is computed as zero when modifying a UDP datagram header. Doing this on IPv4 and TCP checksums is unnecessary but legal. Add a wrapper for net_checksum_finish() that makes the substitution. (We can't just change net_checksum_finish(), as that function is also used by receivers to verify checksums, and in that case the expected value is always 0x0000.) Signed-off-by: Ed Swierk <eswierk@skyportsystems.com> Signed-off-by: Jason Wang <jasowang@redhat.com> |
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checksum.h | ||
eth.h | ||
filter.h | ||
net.h | ||
queue.h | ||
slirp.h | ||
tap.h | ||
vhost-user.h | ||
vhost_net.h |