Snapshot 270198 compile error

On linux-elf:
pqcomm.c: In function `StreamServerPort':
pqcomm.c:605: structure has no member named `sun_len'
pqcomm.c: In function `StreamOpen':
pqcomm.c:760: structure has no member named `sun_len'

Yes,
the sun_len member of struct sockaddr_un is BSD-specific.
It is not there in Linux, nor in a SVR4-system we run here.

I had hard-coded the extra offset to 1 in the UNIXSOCK_PATH macro,
maybe 2 or 4 works OK on all systems.

regards,
--
---------------------------------------------
G�ran Thyni, sysadm, JMS Bildbasen, Kiruna

On linux-elf:
pqcomm.c: In function `StreamServerPort':
pqcomm.c:605: structure has no member named `sun_len'
pqcomm.c: In function `StreamOpen':
pqcomm.c:760: structure has no member named `sun_len'

Yes,
the sun_len member of struct sockaddr_un is BSD-specific.
It is not there in Linux, nor in a SVR4-system we run here.

I had hard-coded the extra offset to 1 in the UNIXSOCK_PATH macro,
maybe 2 or 4 works OK on all systems.

Gee, thanks. This does help tremendously. The protocol overhaul person
did not have the sun_len field, thought the +1 as a mistake of counting
the trailing null and removed it. I will apply the following patch
which should fix the situation. One problem is that under BSD, we never
set the sun_len field, but it still seems to work, and I can't think of
a platform-safe way of doing the assignment, so I will leave it alone.

---------------------------------------------------------------------------

*** ./include/libpq/pqcomm.h.orig	Tue Jan 27 07:25:25 1998
--- ./include/libpq/pqcomm.h	Tue Jan 27 07:36:34 1998
***************
*** 35,42 ****

#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
! sizeof ((sun).sun_len) + sizeof ((sun).sun_family))
!

  /*
   * These manipulate the frontend/backend protocol version number.
--- 35,46 ----

#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
! + 1 + sizeof ((sun).sun_family))
! /*
! * + 1 is for BSD-specific sizeof((sun).sun_len)
! * We never actually set sun_len, and I can't think of a
! * platform-safe way of doing it, but the code still works. bjm
! */

/*
* These manipulate the frontend/backend protocol version number.

--
Bruce Momjian
maillist@candle.pha.pa.us

On linux-elf:
pqcomm.c: In function `StreamServerPort':
pqcomm.c:605: structure has no member named `sun_len'
pqcomm.c: In function `StreamOpen':
pqcomm.c:760: structure has no member named `sun_len'

Yes,
the sun_len member of struct sockaddr_un is BSD-specific.
It is not there in Linux, nor in a SVR4-system we run here.

I had hard-coded the extra offset to 1 in the UNIXSOCK_PATH macro,
maybe 2 or 4 works OK on all systems.

I have applied a patch to document the +1 in the socket length.

--
Bruce Momjian
maillist@candle.pha.pa.us

Bruce Momjian wrote:

#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
! + 1 + sizeof ((sun).sun_family))
! /*
! * + 1 is for BSD-specific sizeof((sun).sun_len)
! * We never actually set sun_len, and I can't think of a
! * platform-safe way of doing it, but the code still works. bjm
! */

I don't think this is going to work. On glibc2 you will end up with a
trailing '\0' in the socket name. You won't be able to see it but I
think it will be there. Is the following version portable?

#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
((char *)&(sun).sun_path[0] - (char *)&(sun)))

Phil

Bruce Momjian wrote:

#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
! + 1 + sizeof ((sun).sun_family))
! /*
! * + 1 is for BSD-specific sizeof((sun).sun_len)
! * We never actually set sun_len, and I can't think of a
! * platform-safe way of doing it, but the code still works. bjm
! */

OK, I am with you. Even better, let's use offset(). Takes care of
possible OS padding between fields too:

---------------------------------------------------------------------------

*** ./include/libpq/pqcomm.h.orig	Tue Jan 27 14:28:27 1998
--- ./include/libpq/pqcomm.h	Tue Jan 27 14:48:15 1998
***************
*** 35,44 ****

#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
! + 1 + sizeof ((sun).sun_family))
/*
! * + 1 is for BSD-specific sizeof((sun).sun_len)
! * We never actually set sun_len, and I can't think of a
* platform-safe way of doing it, but the code still works. bjm
*/

--- 35,44 ----

#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
! offsetof(struct sockaddr_un, sun_path))
/*
! * We do this because sun_len is in BSD's struct, while others don't.
! * We never actually set BSD's sun_len, and I can't think of a
* platform-safe way of doing it, but the code still works. bjm
*/

--
Bruce Momjian
maillist@candle.pha.pa.us