Alvaro Herrera <[email protected]> writes: > Robbie Harwood wrote: >> Michael Paquier <[email protected]> writes: > >> > + iov[0].iov_base = lenbuf; >> > + iov[0].iov_len = 4; >> > + iov[1].iov_base = output.value; >> > + iov[1].iov_len = output.length; >> > + >> > + ret = writev(port->sock, iov, 2); >> > >> > writev and iovec are not present on Windows, so this code would never >> > compile there, and it does not sound that this patch is a reason >> > sufficient enough to drop support of GSSAPI on Windows. >> >> Um. Okay. I guess on Windows I'll make two write calls then, since the >> only other option I see is to hit alloc again here. > > Hmm, I wouldn't push my luck by using writev here at all. We don't use > writev/readv anywhere, and it's quite possible that they are not present > on older Unixen which we still support. > http://pubs.opengroup.org/onlinepubs/009695399/functions/writev.html > says writev was introduced in "issue 4 version 2", which AFAICT is the > 2004 version, but our baseline is SUSv2 (1997). So it's definitely not > workable.
Understood. What do you suggest instead? To give some context here,
writev() is being used here because I have a GSSAPI payload that is
(effectively) opaque and need to include length in it. The only
alternatives I can see are either allocating a new buffer and reading
the payload + length into it (incurs additional memory overhead), or
calling a write/send function twice (incurs syscall overhead at
minimum).
>> > + {
>> > + {"gss_encrypt", PGC_USERSET, CONN_AUTH_SECURITY,
>> > + gettext_noop("Require encryption for all GSSAPI connections."),
>> > + NULL,
>> > + GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
>> > + },
>> > + &gss_encrypt, false, check_gss_encrypt, assign_gss_encrypt, NULL
>> > + },
>
> Why is this marked NOT_IN_SAMPLE?
Well, because it's not something that's supposed to be set in the file
(and indeed, you can't set it there, if I understand
GUC_DISALLOW_IN_FILE). It's used only as a connection parameter, and I
use its presence / absence for the client and server to negotiate GSSAPI
encryption support.
signature.asc
Description: PGP signature
