Remove configure probes for sockaddr_storage members.

Remove four probes for members of sockaddr_storage.  Keep only the probe
for sockaddr's sa_len, which is enough for our two remaining places that
know about _len fields:

1.  ifaddr.c needs to know if sockaddr has sa_len to understand the
result of ioctl(SIOCGIFCONF).  Only AIX is still using the relevant code
today, but it seems like a good idea to keep it compilable on Linux.

2.  ip.c was testing for presence of ss_len to decide whether to fill in
sun_len in our getaddrinfo_unix() function.  It's just as good to test
for sa_len.  If you have one, you have them all.

(The code in #2 isn't actually needed at all on several OSes I checked
since modern versions ignore sa_len on input to system calls.  Proving
that's the case for all relevant OSes is left for another day, but
wouldn't get rid of that last probe anyway if we still want it for #1.)

Discussion: https://postgr.es/m/CA%2BhUKGJJjF2AqdU_Aug5n2MAc1gr%3DGykNjVBZq%2Bd6Jrcp3Dyvg%40mail.gmail.com

config/c-library.m4

@@ -73,20 +73,14 @@ AC_DEFUN([PGAC_UNION_SEMUN],
 ])])# PGAC_UNION_SEMUN
 
 
-# PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS
-# --------------------------------------
-# Check the members of `struct sockaddr_storage'.  We need to know about
-# ss_family and ss_len.  (Some platforms follow RFC 2553 and call them
-# __ss_family and __ss_len.)  We also check struct sockaddr's sa_len.
-AC_DEFUN([PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS],
-[AC_CHECK_MEMBERS([struct sockaddr_storage.ss_family,
-		   struct sockaddr_storage.__ss_family,
-		   struct sockaddr_storage.ss_len,
-		   struct sockaddr_storage.__ss_len,
-		   struct sockaddr.sa_len], [], [],
+# PGAC_STRUCT_SOCKADDR_MEMBERS
+# ----------------------------
+# Check if struct sockaddr and subtypes have 4.4BSD-style length.
+AC_DEFUN([PGAC_STRUCT_SOCKADDR_SA_LEN],
+[AC_CHECK_MEMBERS([struct sockaddr.sa_len], [], [],
 [#include <sys/types.h>
 #include <sys/socket.h>
-])])# PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS
+])])# PGAC_STRUCT_SOCKADDR_MEMBERS
 
 
 # PGAC_TYPE_LOCALE_T

configure

@@ -14990,54 +14990,6 @@ _ACEOF
 
 fi
 
-ac_fn_c_check_member "$LINENO" "struct sockaddr_storage" "ss_family" "ac_cv_member_struct_sockaddr_storage_ss_family" "#include <sys/types.h>
-#include <sys/socket.h>
-
-"
-if test "x$ac_cv_member_struct_sockaddr_storage_ss_family" = xyes; then :
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY 1
-_ACEOF
-
-
-fi
-ac_fn_c_check_member "$LINENO" "struct sockaddr_storage" "__ss_family" "ac_cv_member_struct_sockaddr_storage___ss_family" "#include <sys/types.h>
-#include <sys/socket.h>
-
-"
-if test "x$ac_cv_member_struct_sockaddr_storage___ss_family" = xyes; then :
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY 1
-_ACEOF
-
-
-fi
-ac_fn_c_check_member "$LINENO" "struct sockaddr_storage" "ss_len" "ac_cv_member_struct_sockaddr_storage_ss_len" "#include <sys/types.h>
-#include <sys/socket.h>
-
-"
-if test "x$ac_cv_member_struct_sockaddr_storage_ss_len" = xyes; then :
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN 1
-_ACEOF
-
-
-fi
-ac_fn_c_check_member "$LINENO" "struct sockaddr_storage" "__ss_len" "ac_cv_member_struct_sockaddr_storage___ss_len" "#include <sys/types.h>
-#include <sys/socket.h>
-
-"
-if test "x$ac_cv_member_struct_sockaddr_storage___ss_len" = xyes; then :
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_STRUCT_SOCKADDR_STORAGE___SS_LEN 1
-_ACEOF
-
-
-fi
 ac_fn_c_check_member "$LINENO" "struct sockaddr" "sa_len" "ac_cv_member_struct_sockaddr_sa_len" "#include <sys/types.h>
 #include <sys/socket.h>
 

configure.ac

@@ -1614,7 +1614,7 @@ PGAC_C_COMPUTED_GOTO
 PGAC_STRUCT_TIMEZONE
 PGAC_UNION_SEMUN
 AC_CHECK_TYPES(socklen_t, [], [], [#include <sys/socket.h>])
-PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS
+PGAC_STRUCT_SOCKADDR_SA_LEN
 
 PGAC_TYPE_LOCALE_T
 

src/common/ip.c

@@ -227,7 +227,7 @@ getaddrinfo_unix(const char *path, const struct addrinfo *hintsp,
 	 * something with it.  To suppress the warning, clamp the struct size to
 	 * what will fit in sun_len.
 	 */
-#ifdef HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
 	unp->sun_len = Min(sizeof(struct sockaddr_un),
 					   ((size_t) 1 << (sizeof(unp->sun_len) * BITS_PER_BYTE)) - 1);
 #endif

src/include/libpq/pqcomm.h

@@ -21,19 +21,6 @@
 #include <netdb.h>
 #include <netinet/in.h>
 
-#ifndef HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY
-#ifdef HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY
-#define ss_family __ss_family
-#else
-#error struct sockaddr_storage does not provide an ss_family member
-#endif
-#endif
-
-#ifdef HAVE_STRUCT_SOCKADDR_STORAGE___SS_LEN
-#define ss_len __ss_len
-#define HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN 1
-#endif
-
 typedef struct
 {
 	struct sockaddr_storage addr;

src/include/pg_config.h.in

@@ -442,18 +442,6 @@
 /* Define to 1 if `sa_len' is a member of `struct sockaddr'. */
 #undef HAVE_STRUCT_SOCKADDR_SA_LEN
 
-/* Define to 1 if `ss_family' is a member of `struct sockaddr_storage'. */
-#undef HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY
-
-/* Define to 1 if `ss_len' is a member of `struct sockaddr_storage'. */
-#undef HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN
-
-/* Define to 1 if `__ss_family' is a member of `struct sockaddr_storage'. */
-#undef HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY
-
-/* Define to 1 if `__ss_len' is a member of `struct sockaddr_storage'. */
-#undef HAVE_STRUCT_SOCKADDR_STORAGE___SS_LEN
-
 /* Define to 1 if `tm_zone' is a member of `struct tm'. */
 #undef HAVE_STRUCT_TM_TM_ZONE
 

src/tools/msvc/Solution.pm

@@ -343,10 +343,6 @@ sub GenerateFiles
 		HAVE_STRUCT_CMSGCRED                     => undef,
 		HAVE_STRUCT_OPTION                       => undef,
 		HAVE_STRUCT_SOCKADDR_SA_LEN              => undef,
-		HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY   => 1,
-		HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN      => undef,
-		HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY => undef,
-		HAVE_STRUCT_SOCKADDR_STORAGE___SS_LEN    => undef,
 		HAVE_STRUCT_TM_TM_ZONE                   => undef,
 		HAVE_SYNC_FILE_RANGE                     => undef,
 		HAVE_SYNCFS                              => undef,