[PATCH 2/5] resolv: Check for inet_ntop failure in ns_sprintrrf

[Florian Weimer]

This makes the output more consistent (either failure or complete
output) and helps with systematic testing with varying buffer
sizes.
---
 resolv/ns_print.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/resolv/ns_print.c b/resolv/ns_print.c
index cef2212fd2..5701e3d0c5 100644
--- a/resolv/ns_print.c
+++ b/resolv/ns_print.c
@@ -141,7 +141,8 @@ ns_sprintrrf(const u_char *msg, size_t msglen,
 	case ns_t_a:
 	  if (rdlen != (size_t)NS_INADDRSZ)
 			goto formerr;
-		(void) inet_ntop(AF_INET, rdata, buf, buflen);
+		if (inet_ntop (AF_INET, rdata, buf, buflen) == NULL)
+		  return -1;
 		addlen(strlen(buf), &buf, &buflen);
 		break;
 
@@ -308,10 +309,11 @@ ns_sprintrrf(const u_char *msg, size_t msglen,
 
 	case ns_t_aaaa:
 	  if (rdlen != (size_t)NS_IN6ADDRSZ)
-			goto formerr;
-		(void) inet_ntop(AF_INET6, rdata, buf, buflen);
-		addlen(strlen(buf), &buf, &buflen);
-		break;
+	    goto formerr;
+	  if (inet_ntop (AF_INET6, rdata, buf, buflen) == NULL)
+	    return -1;
+	  addlen(strlen(buf), &buf, &buflen);
+	  break;
 
 	case ns_t_loc: {
 		char t[255];
@@ -400,7 +402,8 @@ ns_sprintrrf(const u_char *msg, size_t msglen,
 			goto formerr;
 
 		/* Address. */
-		(void) inet_ntop(AF_INET, rdata, buf, buflen);
+		if (inet_ntop (AF_INET, rdata, buf, buflen) == NULL)
+		  return -1;
 		addlen(strlen(buf), &buf, &buflen);
 		rdata += NS_INADDRSZ;
 
@@ -542,7 +545,8 @@ ns_sprintrrf(const u_char *msg, size_t msglen,
 			if (rdata + pbyte >= edata) goto formerr;
 			memset(&a, 0, sizeof(a));
 			memcpy(&a.s6_addr[pbyte], rdata, sizeof(a) - pbyte);
-			(void) inet_ntop(AF_INET6, &a, buf, buflen);
+			if (inet_ntop (AF_INET6, &a, buf, buflen) == NULL)
+			  return -1;
 			addlen(strlen(buf), &buf, &buflen);
 			rdata += sizeof(a) - pbyte;
 		}
-- 
2.53.0