This reverts commit 2886c93d1b.
The original commit has two problems:
* It sets SO_SNDBUF to be as large as MAXLINE. But for unix domain
sockets, the send buffer is bypassed. Packets go directly to the
peer's receive buffer, so setting and querying SO_SNDBUF is
ineffective. To ensure that the socket can accept messages of a
certain size, it would be necessary to add a SO_PEERRCVBUF socket
option that could query the connected peer's receive buffer size.
* It sets MAXLINE to 8 kB, which is larger than the default sockbuf size
of 4 kB. That's ok for the builtin syslogd, which sets its recvbuf
to 80 kB, but not ok for alternative sysloggers, like rsyslogd, which
use the default size.
As a consequence, writing messages of more than 4 kB with syslog() as a
non-root user while running rsyslogd would cause the logging application
to spin indefinitely within syslog().
PR: 260126
MFC: 2 weeks
Sponsored by: Axcient
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D33199
943c446629