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Enter epoch when addding IPv4 multicast forwarding cache entry
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Authored by karels on Mar 21 2022, 3:07 PM.
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Details

Summary

The code path from the IPv4 multicast setsockopt could call ip_output()
without entering an epoch. Specifically, the MRT_ADD_MFC setbsocopt
would call add_mfc(), which in turn called ip_mdq() to send queued
packets. This resulted in an epoch assert failure in ip_output().
Enter an epoch in add_mfc(), and add some epoch asserts to check
for similar failures.

Test Plan

tested with mrouted and rwhod -m

Diff Detail

Repository
rG FreeBSD src repository
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Event Timeline

bz added a subscriber: bz.

Sounds reasonable to me and I like the extra asserts for documentation purposes; I always wonder if the entire ioctl paths should just acquire/release epoch but that's a totally different can of worms.

This revision is now accepted and ready to land.Mar 21 2022, 3:24 PM
cy added a subscriber: cy.