resolv: Move ns_name_unpack to its own file and into libc

Reformat to GNU style. Avoid out-of-bounds buffer arithmetic.
Eliminate the labellen function.

The symbol was moved using scripts/move-symbol-to-libc.py.

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

69 files changed, 187 insertions, 115 deletions

diff --git a/include/arpa/nameser.h b/include/arpa/nameser.h
index f1a696514a..2396a43030 100644
--- a/include/arpa/nameser.h
+++ b/include/arpa/nameser.h
@@ -68,7 +68,6 @@ libresolv_hidden_proto (ns_parserr)
 libresolv_hidden_proto (ns_name_pton)
 libresolv_hidden_proto (ns_name_pack)
 libresolv_hidden_proto (ns_name_skip)
-libresolv_hidden_proto (ns_name_unpack)
 libresolv_hidden_proto (ns_name_compress)
 libresolv_hidden_proto (ns_name_uncompress)
 libresolv_hidden_proto (ns_sprintrr)
@@ -80,6 +79,8 @@ libresolv_hidden_proto (ns_format_ttl)
 
 extern __typeof (ns_name_ntop) __ns_name_ntop;
 libc_hidden_proto (__ns_name_ntop)
+extern __typeof (ns_name_unpack) __ns_name_unpack;
+libc_hidden_proto (__ns_name_unpack)
 
 # endif /* !_ISOMAC */
 #endif
diff --git a/resolv/Makefile b/resolv/Makefile
index bb16175654..469a9a55ae 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -33,6 +33,7 @@ routines := \
   inet_ntop \
   inet_pton \
   ns_name_ntop \
+  ns_name_unpack \
   nsap_addr \
   res-close \
   res-state \
diff --git a/resolv/Versions b/resolv/Versions
index 4bf1a13d48..9b5c4d9733 100644
--- a/resolv/Versions
+++ b/resolv/Versions
@@ -26,6 +26,7 @@ libc {
   }
   GLIBC_2.9 {
     ns_name_ntop;
+    ns_name_unpack;
   }
   GLIBC_2.34 {
 %if PTHREAD_IN_LIBC
@@ -35,6 +36,7 @@ libc {
     getaddrinfo_a;
 %endif
     ns_name_ntop;
+    ns_name_unpack;
   }
   GLIBC_PRIVATE {
 %if !PTHREAD_IN_LIBC
@@ -45,6 +47,7 @@ libc {
     __inet_pton_length;
     __res_iclose;
     __ns_name_ntop;
+    __ns_name_unpack;
     __resolv_context_get;
     __resolv_context_get_override;
     __resolv_context_get_preinit;
@@ -147,7 +150,6 @@ libresolv {
     ns_name_rollback;
     ns_name_skip;
     ns_name_uncompress;
-    ns_name_unpack;
     ns_parse_ttl;
     ns_parserr;
     ns_put16;
@@ -162,7 +164,6 @@ libresolv {
   GLIBC_PRIVATE {
     __ns_get16;
     __ns_get32;
-    __ns_name_unpack;
     __res_context_hostalias;
     __res_context_query;
     __res_context_search;
diff --git a/resolv/ns_name.c b/resolv/ns_name.c
index 4990003746..a0d541f110 100644
--- a/resolv/ns_name.c
+++ b/resolv/ns_name.c
@@ -218,87 +218,6 @@ ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
 }
 
 /*%
- *	Unpack a domain name from a message, source may be compressed.
- *
- * return:
- *\li	-1 if it fails, or consumed octets if it succeeds.
- */
-int
-ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
-	       u_char *dst, size_t dstsiz)
-{
-	const u_char *srcp, *dstlim;
-	u_char *dstp;
-	int n, len, checked, l;
-
-	len = -1;
-	checked = 0;
-	dstp = dst;
-	srcp = src;
-	dstlim = dst + dstsiz;
-	if (srcp < msg || srcp >= eom) {
-		__set_errno (EMSGSIZE);
-		return (-1);
-	}
-	/* Fetch next label in domain name. */
-	while ((n = *srcp++) != 0) {
-		/* Check for indirection. */
-		switch (n & NS_CMPRSFLGS) {
-		case 0:
-			/* Limit checks. */
-			if ((l = labellen(srcp - 1)) < 0) {
-				__set_errno (EMSGSIZE);
-				return(-1);
-			}
-			if (dstp + l + 1 >= dstlim || srcp + l >= eom) {
-				__set_errno (EMSGSIZE);
-				return (-1);
-			}
-			checked += l + 1;
-			*dstp++ = n;
-			memcpy(dstp, srcp, l);
-			dstp += l;
-			srcp += l;
-			break;
-
-		case NS_CMPRSFLGS:
-			if (srcp >= eom) {
-				__set_errno (EMSGSIZE);
-				return (-1);
-			}
-			if (len < 0)
-				len = srcp - src + 1;
-			srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
-			if (srcp < msg || srcp >= eom) {  /*%< Out of range. */
-				__set_errno (EMSGSIZE);
-				return (-1);
-			}
-			checked += 2;
-			/*
-			 * Check for loops in the compressed name;
-			 * if we've looked at the whole message,
-			 * there must be a loop.
-			 */
-			if (checked >= eom - msg) {
-				__set_errno (EMSGSIZE);
-				return (-1);
-			}
-			break;
-
-		default:
-			__set_errno (EMSGSIZE);
-			return (-1);			/*%< flag error */
-		}
-	}
-	*dstp = '\0';
-	if (len < 0)
-		len = srcp - src;
-	return (len);
-}
-libresolv_hidden_def (ns_name_unpack)
-strong_alias (ns_name_unpack, __ns_name_unpack)
-