Solaris ident authentication using unix domain sockets

Hi,
    I have a patch that I have been using to support postgresql's
notion of ident authentication when using unix domain sockets on
Solaris.  This patch basically just adds support for using
getupeercred() on Solaris so unix sockets and ident auth works just
like it does on Linux and elsewhere.

    This was my first attempt wrestling with automake.  I've
tested it builds properly after it is applied and autoreconf is run
on RHEL4/Linux/x86.  I am using the patch currently on Solaris 10 /
x86.

Garick

diff -cr postgresql_CVS/configure.in postgresql/configure.in
*** postgresql_CVS/configure.in    Tue Jun 24 15:52:30 2008
--- postgresql/configure.in    Tue Jun 24 15:57:22 2008
***************
*** 1095,1101 ****
  AC_FUNC_ACCEPT_ARGTYPES
  PGAC_FUNC_GETTIMEOFDAY_1ARG

! AC_CHECK_FUNCS([cbrt dlopen fcvt fdatasync getpeereid getrlimit memmove poll pstat readlink setproctitle setsid
sigprocmasksymlink sysconf towlower utime utimes waitpid wcstombs]) 

  AC_CHECK_DECLS(fdatasync, [], [], [#include <unistd.h>])
  AC_CHECK_DECLS(posix_fadvise, [], [], [#include <fcntl.h>])
--- 1095,1101 ----
  AC_FUNC_ACCEPT_ARGTYPES
  PGAC_FUNC_GETTIMEOFDAY_1ARG

! AC_CHECK_FUNCS([getpeerucred cbrt dlopen fcvt fdatasync getpeereid getrlimit memmove poll pstat readlink setproctitle
setsidsigprocmask symlink sysconf towlower utime utimes waitpid wcstombs]) 

  AC_CHECK_DECLS(fdatasync, [], [], [#include <unistd.h>])
  AC_CHECK_DECLS(posix_fadvise, [], [], [#include <fcntl.h>])
diff -cr postgresql_CVS/src/backend/libpq/hba.c postgresql/src/backend/libpq/hba.c
*** postgresql_CVS/src/backend/libpq/hba.c    Tue Jun 24 15:52:32 2008
--- postgresql/src/backend/libpq/hba.c    Tue Jun 24 15:53:00 2008
***************
*** 25,30 ****
--- 25,33 ----
  #include <sys/uio.h>
  #include <sys/ucred.h>
  #endif
+ #if defined(HAVE_GETPEERUCRED)
+ #include <ucred.h>
+ #endif
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <unistd.h>
***************
*** 1500,1505 ****
--- 1503,1539 ----
      strlcpy(ident_user, pass->pw_name, IDENT_USERNAME_MAX + 1);

      return true;
+ #elif defined(HAVE_GETPEERUCRED) /* Solaris > 10 */
+     uid_t        uid;
+     gid_t        gid;
+     struct passwd     *pass;
+     int         ucred_ok=1;
+     ucred_t *ucred = NULL;
+     if (getpeerucred(sock, &ucred) == -1)
+         ucred_ok = 0;
+     if (ucred_ok && (uid = ucred_geteuid(ucred)) == -1 )
+         ucred_ok = 0;
+     if (ucred_ok && (gid = ucred_getrgid(ucred)) == -1 )
+         ucred_ok = 0;
+     if (ucred)
+         ucred_free(ucred);
+     if (!ucred_ok) {
+         /* We didn't get a valid credentials struct. */
+         ereport(LOG, (
+              "could not get peer credentials: %s",
+                 strerror(errno)));
+         return false;
+     }
+     pass = getpwuid(uid);
+     if (pass == NULL)
+     {
+         ereport(LOG,
+             (errmsg("local user with ID %d does not exist",
+                     (int) uid)));
+         return false;
+     }
+     strlcpy(ident_user, pass->pw_name, IDENT_USERNAME_MAX + 1);
+     return true;
  #elif defined(HAVE_STRUCT_CMSGCRED) || defined(HAVE_STRUCT_FCRED) || (defined(HAVE_STRUCT_SOCKCRED) &&
defined(LOCAL_CREDS))
      struct msghdr msg;