Issue in bio_dgram_test in OpenSSL 3.2+

[Akira Kato <kato%wide.ad.jp@localhost>]

While this may not be an issue just for openssl, I'd post here.

It is possible to compile openssl (3.6.3) in pkgsrc, in either 9.4,
10.1, or even 11.0RC6. But when you run "make test", it stops in
"04-test_bio_dgram.t ......................".  Actually bio_dgram_test
(in test directory) consists of 2 tests.  The first test hungs while
the second test completes without any issue.

bio_dgram_test was introduced in openssl-3.2.0, and I tested several
versions of openssl on NetBSD11.0RC6 for amd64, the situation was the
same.

When it was compiled with -g, I ran the program under gdb, and
interrupted it, and the traceback looked like as follows:

#0  0x000076e199c6423a in recvmmsg () from /usr/lib/libc.so.12
#1  0x000076e19a04419c in recvmmsg () from /usr/lib/libpthread.so.1
#2  0x000000000041eee8 in dgram_recvmmsg ()
#3  0x000000000041a27a in BIO_recvmmsg ()
#4  0x0000000000405189 in do_recvmmsg (b=b@entry=0x76e199c0d580, 
    msg=msg@entry=0x7f7fff79e020, num_msg=num_msg@entry=128, 
    num_processed=num_processed@entry=0x7f7fff79ca88, flags=0)
    at test/bio_dgram_test.c:89
#5  0x00000000004063f0 in test_bio_dgram_impl (af=<optimized out>, use_local=0)
    at test/bio_dgram_test.c:408
#6  0x0000000000406ee8 in run_tests ()
#7  0x0000000000735cf0 in main ()

Note that on OpenBSD 7.9 and FreeBSD 14.4, bio_dgram_test successfully
completed without any error.

I failed to look into the detail what bio_dgram_test did, what
condition(s) cause the hung in recvmmsg(). I'd ask any suggestions
from the experts.

Regards,

-- Akira Kato, WIDE Project