Re: close(2) on a PF_ROUTE socket returns -1 and sets errno to EOPNOTSUPP

> On 15 Jan 2023, at 13:50, Alexander V. Chernikov <melifaro@ipfw.ru> wrote:
> 
> 
> 
>> On 14 Jan 2023, at 20:46, Guy Yur <guyyur@gmail.com> wrote:
>> 
>> Hi,
>> 
>> close(2) on a PF_ROUTE socket returns -1 and sets errno to EOPNOTSUPP.
>> I am testing 14.0-CURRENT (main branch) built today.
>> On 13.1-RELEASE-p5 close returns 0.
>> 
>> The problem looks to be related to 36b10ac2cd18a535cac20ccf51e3fc6c408671e8.
>> 
>> The commit removed rts_disconnect and initialization for .pru_disconnect.
>> After the change, .pr_disconnect is not initialized in rtsock.c
>> so now it is set to pr_disconnect_notsupp.
>> This causes flow of:
>>  soclose()
>>  sodisconnect()
>>  so->so_proto->pr_disconnect()
>>  pr_disconnect_notsupp()
>>  return EOPNOTSUPP
>> On 13.1 it called the raw socket disconnect which returned ENOTCONN.
>> 
>> Noticed in dhcpcd error: if_route (ADD): Operation not supported
>> dhcpcd with privsep called write() which failed with EEXIST (expected since
>> route already existed) and then close() which overwrote the errno to
>> EOPNOTSUPP and the parent process received back EOPNOTSUPP instead of EEXIST.
> Thank you for the report!
> I’ve created https://reviews.freebsd.org/D38059 to address the issue.
Landed in 42904794b804.
>> 
>> 
>> 
>> Simple test program (prints error on head, no error on 13.1):
>> 
>> #include <sys/types.h>
>> #include <sys/time.h>
>> #include <sys/socket.h>
>> #include <net/if.h>
>> #include <net/route.h>
>> #include <unistd.h>
>> #include <err.h>
>> 
>> int main(int argc, char *argv[])
>> {
>>  int s = socket(PF_ROUTE, SOCK_RAW, 0);
>>  if (s == -1)
>>    err(1, "socket()");
>>  if (close(s) == -1)
>>    err(1, "close()");
>>  return 0;
>> }
>> 
>> 
>> Regards,
>> Guy Yur