The default route a guest obtains via NDP has an expiry. We set this to the maximum allowed, 65535s (about 18 hours). We missed, however, that after that expiry, the guest won't send a new Router Solicitation. Instead it expects an unsolicited Router Advertisement to have come at some point before the expiry. This means that on an IPv6 setup, the default will disappear after 18 hours. Correct this by sending unsolicited Router Advertisements as required by RFC 4861. Along the way we make a number of small cleanups to the NDP code. Link: https://github.com/kubevirt/kubevirt/issues/13191 v2: * Some minor stylistic fixes * Use srandom() * Better explanation of the random requirements for the RAs David Gibson (8): ndp: Remove redundant update to addr_seen ndp: Add ndp_send() helper ndp: Split out helpers for sending specific NDP message types ndp: Use struct assignment in preference to memcpy() for IPv6 addresses ndp: Make route lifetime a #define util: Add general low-level random bytes helper passt: Seed libc's pseudo random number generator ndp: Send unsolicited Router Advertisements ip.h | 9 +++ ndp.c | 219 +++++++++++++++++++++++++++++++++++++------------------- ndp.h | 7 +- passt.c | 42 ++++------- util.c | 54 ++++++++++++++ util.h | 2 + 6 files changed, 228 insertions(+), 105 deletions(-) -- 2.47.0