Re: bin/57952 (dhcpcd(8) inexplicably terminated in the night)

[Roy Marples <roy%marples.name@localhost>]

The following reply was made to PR bin/57952; it has been noted by GNATS.

From: Roy Marples <roy%marples.name@localhost>
To: "gnats-bugs" <gnats-bugs%netbsd.org@localhost>
Cc: "riastradh" <riastradh%NetBSD.org@localhost>, "roy" <roy%netbsd.org@localhost>,
	"gnats-admin" <gnats-admin%netbsd.org@localhost>,
	"netbsd-bugs" <netbsd-bugs%netbsd.org@localhost>,
	"campbell+netbsd" <campbell+netbsd%mumble.net@localhost>
Subject: Re: bin/57952 (dhcpcd(8) inexplicably terminated in the night)
Date: Thu, 22 Feb 2024 23:37:23 +0000

 ----- On Thu, 22 Feb 2024 15:36:31 +0000    wrote --- 
   > Could I trouble you to take a look at this, roy?
 
 So dhcpcd crashed. As it runs in an empty chroot without the ability to create anything it has no means of saving any segfault information to the best of my knowledge.
 
 > dhcpcd[622]: ps_sendcmdmsg: No buffer space available
 > dhcpcd[622]: ps_inet_recvra: No buffer space available
 
 This means we tried to send a message over privsep that was bigger than what we allocate for.
 For reference, it's a fairly large allocation:
 #define	PS_BUFLEN		((64 * 1024) +			\
 				 sizeof(struct ps_msghdr) +	\
 				 sizeof(struct msghdr) +	\
 				 CMSG_SPACE(sizeof(struct in6_pktinfo) + \
 					    sizeof(int)))
 
 Basically this should be more than enough for an unfragmented message either from ICMP or UDP in any address family.
 It seems that it received a RA message dhcpcd really didn't like.
 
 > dhcpcd[622]: ure0: fe80::${ROGUEDEVICE}: no longer a default router
 > syslogd[423]: last message repeated 6 times
 > dhcpcd[622]: ps_inet_dodispatch: Connection reset by peer
 
 This is the manager process noting that the network proxy has gone away.
 
 I'll see if manually tripping the above condition causes an error or not and try to fix it.
 Bit busy until after the weekend, so hopefully I'll have something next week.
 
 Roy