resolv: Move dn_expand to its own file and into libc

And reformat to GNU style.

This switches back to the dn_expand name for the ABI symbol and turns
__dn_expand into a compatibility symbol.  With the improved namespace
management in current glibc, it is no longer necessary to use a
private namespace symbol.  To avoid old code binding to a
GLIBC_PRIVATE symbol by accident, use __libc_dn_expand for the
internal symbol name.

The symbols dn_expand, __dnexpand were moved using
scripts/move-symbol-to-libc.py, followed by an adjustment to make
dn_expand the only GLIBC_2.34 symbol.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

76 files changed, 219 insertions, 90 deletions

diff --git a/include/resolv.h b/include/resolv.h
index daf4a74777..44fc0c346f 100644
--- a/include/resolv.h
+++ b/include/resolv.h
@@ -44,7 +44,6 @@ libresolv_hidden_proto (_sethtent)
 libresolv_hidden_proto (_gethtent)
 libresolv_hidden_proto (_gethtbyaddr)
 libresolv_hidden_proto (_gethtbyname2)
-libresolv_hidden_proto (__dn_expand)
 libresolv_hidden_proto (__dn_comp)
 libresolv_hidden_proto (__dn_skipname)
 libresolv_hidden_proto (__res_hnok)
@@ -66,5 +65,8 @@ libresolv_hidden_proto (__res_queriesmatch)
 libresolv_hidden_proto (__b64_ntop)
 libresolv_hidden_proto (__dn_count_labels)
 
+extern __typeof (dn_expand) __libc_dn_expand;
+libc_hidden_proto (__libc_dn_expand)
+
 # endif /* _RESOLV_H_ && !_ISOMAC */
 #endif
diff --git a/resolv/Makefile b/resolv/Makefile
index 64600ab845..3e7de81fb5 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -28,6 +28,7 @@ headers	:= resolv.h bits/types/res_state.h \
 	   sys/bitypes.h
 
 routines := \
+  dn_expand \
   herror \
   inet_addr \
   inet_ntop \
diff --git a/resolv/Versions b/resolv/Versions
index a676be2e42..4a9203042f 100644
--- a/resolv/Versions
+++ b/resolv/Versions
@@ -3,6 +3,7 @@ libc {
     __h_errno_location;
     __res_randomid;
     _res;
+    dn_expand;
     h_errlist;
     h_nerr;
     herror;
@@ -10,6 +11,7 @@ libc {
     res_init;
   }
   GLIBC_2.2 {
+    __dn_expand;
     __res_init;
     __res_nclose;
     __res_ninit;
@@ -40,6 +42,7 @@ libc {
     gai_suspend;
     getaddrinfo_a;
 %endif
+    dn_expand;
     ns_name_compress;
     ns_name_ntop;
     ns_name_pack;
@@ -55,6 +58,7 @@ libc {
     __h_errno;
     __inet_aton_exact;
     __inet_pton_length;
+    __libc_dn_expand;
     __ns_name_compress;
     __ns_name_ntop;
     __ns_name_pack;
@@ -120,7 +124,6 @@ libresolv {
     _res_opcodes;
     _res_resultcodes;
     _sethtent;
-    dn_expand;
     inet_net_ntop;
     inet_net_pton;
     inet_neta;
@@ -135,7 +138,6 @@ libresolv {
     res_send_setrhook;
   }
   GLIBC_2.2 {
-    __dn_expand;
     __res_hostalias;
     __res_mkquery;
     __res_nmkquery;
diff --git a/resolv/compat-gethnamaddr.c b/resolv/compat-gethnamaddr.c
index 0e24dcbbcc..1c630fcb3d 100644
--- a/resolv/compat-gethnamaddr.c
+++ b/resolv/compat-gethnamaddr.c
@@ -179,7 +179,7 @@ getanswer (const querybuf *answer, int anslen, const char *qname, int qtype)
 		__set_h_errno (NO_RECOVERY);
 		return (NULL);
 	}
-	n = dn_expand(answer->buf, eom, cp, bp, buflen);
+	n = __libc_