Clean up getaddrinfo(3) calls to make them look like the canonical

example from the man page. While there was nothing wrong this pattern
makes it easier to figure that out.
While here be more paranoid how much we memcpy(3).
Looks clean to deraadt@

1 files changed, 38 insertions, 43 deletions

diff --git a/sbin/ping6/ping6.c b/sbin/ping6/ping6.c
index ef9ad6d6757..e73d7026773 100644
--- a/sbin/ping6/ping6.c
+++ b/sbin/ping6/ping6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ping6.c,v 1.109 2015/08/30 18:27:03 florian Exp $	*/
+/*	$OpenBSD: ping6.c,v 1.110 2015/08/30 18:48:45 florian Exp $	*/
 /*	$KAME: ping6.c,v 1.163 2002/10/25 02:19:06 itojun Exp $	*/
 
 /*
@@ -175,10 +175,8 @@ u_int options;
 int mx_dup_ck = MAX_DUP_CHK;
 char rcvd_tbl[MAX_DUP_CHK / 8];
 
-struct addrinfo *res;
 struct sockaddr_in6 dst;	/* who to ping6 */
 struct sockaddr_in6 src;	/* src addr of this packet */
-socklen_t srclen;
 int datalen = DEFDATALEN;
 int s;				/* socket file descriptor */
 u_char outpack[MAXPACKETLEN];
@@ -250,10 +248,11 @@ void	 usage(void);
 int
 main(int argc, char *argv[])
 {
+	struct addrinfo *res0;
 	struct itimerval itimer;
 	struct sockaddr_in6 from;
 	struct addrinfo hints;
-	int ch, i, packlen, preload, optval, ret_ga;
+	int ch, i, packlen, preload, optval, error;
 	u_char *datap, *packet;
 	char *e, *target, *ifname = NULL, *gateway = NULL;
 	const char *errstr;
@@ -424,18 +423,16 @@ main(int argc, char *argv[])
 			hints.ai_socktype = SOCK_RAW;
 			hints.ai_protocol = IPPROTO_ICMPV6;
 
-			ret_ga = getaddrinfo(optarg, NULL, &hints, &res);
-			if (ret_ga) {
+			error = getaddrinfo(optarg, NULL, &hints, &res0);
+			if (error)
 				errx(1, "invalid source address: %s",
-				     gai_strerror(ret_ga));
-			}
-			/*
-			 * res->ai_family must be AF_INET6 and res->ai_addrlen
-			 * must be sizeof(src).
-			 */
-			memcpy(&src, res->ai_addr, res->ai_addrlen);
-			srclen = res->ai_addrlen;
-			freeaddrinfo(res);
+				     gai_strerror(error));
+
+			if (res0->ai_family != AF_INET6 || res0->ai_addrlen !=
+			    sizeof(src))
+				errx(1, "invalid source address");
+			memcpy(&src, res0->ai_addr, sizeof(src));
+			freeaddrinfo(res0);
 			options |= F_SRCADDR;
 			break;
 		case 's':		/* size of packet to send */
@@ -502,49 +499,47 @@ main(int argc, char *argv[])
 	hints.ai_socktype = SOCK_RAW;
 	hints.ai_protocol = IPPROTO_ICMPV6;
 
-	ret_ga = getaddrinfo(target, NULL, &hints, &res);
-	if (ret_ga)
-		errx(1, "%s", gai_strerror(ret_ga));
-	if (res->ai_canonname)
-		hostname = res->ai_canonname;
-	else
+	error = getaddrinfo(target, NULL, &hints, &res0);
+	if (error)
+		errx(1, "host %s: %s", target, gai_strerror(error));
+	if (res0->ai_canonname) {
+		if ((hostname = strdup(res0->ai_canonname)) == NULL)
+			errx(1, "out of memory");
+	} else
 		hostname = target;
-
-	if (!res->ai_addr)
+	if (res0->ai_next && (options & F_VERBOSE))
+		warnx("host resolves to multiple addresses");
+	if (res0->ai_family != AF_INET6 || res0->ai_addrlen != sizeof(dst))
 		errx(1, "getaddrinfo failed");
+	memcpy(&dst, res0->ai_addr, sizeof(dst));
 
-	memcpy(&dst, res->ai_addr, res->ai_addrlen);
+	freeaddrinfo(res0);
 
 	/* set the source address if specified. */
 	if ((options & F_SRCADDR) &&
-	    bind(s, (struct sockaddr *)&src, srclen) != 0) {
+	    bind(s, (struct sockaddr *)&src, sizeof(src)) != 0) {
 		err(1, "bind");
 	}
 
 	/* set the gateway (next hop) if specified */
 	if (gateway) {
-		struct addrinfo ghints, *gres;
-		int error;
-
-		memset(&ghints, 0, sizeof(ghints));
-		ghints.ai_family = AF_INET6;
-		ghints.ai_socktype = SOCK_RAW;
-		ghints.ai_protocol = IPPROTO_ICMPV6;
-
-		error = getaddrinfo(gateway, NULL, &ghints, &gres);
-		if (error) {
-			errx(1, "getaddrinfo for the gateway %s: %s",
-			     gateway, gai_strerror(error));
-		}
-		if (gres->ai_next && (options & F_VERBOSE))
+		memset(&hints, 0, sizeof(hints));
+		hints.ai_family = AF_INET6;
+		hints.ai_socktype = SOCK_RAW;
+		hints.ai_protocol = IPPROTO_ICMPV6;
+
+		error = getaddrinfo(gateway, NULL, &hints, &res0);
+		if (error)
+			errx(1, "gateway %s: %s", gateway, gai_strerror(error));
+
+		if (res0->ai_next && (options & F_VERBOSE))
 			warnx("gateway resolves to multiple addresses");
 
-		if (setsockopt(s, IPPROTO_IPV6, IPV6_NEXTHOP,
-		    gres->ai_addr, gres->ai_addrlen)) {
+		if (setsockopt(s, IPPROTO_IPV6, IPV6_NEXTHOP, res0->ai_addr,
+		    res0->ai_addrlen))
 			err(1, "setsockopt(IPV6_NEXTHOP)");
-		}
 
-		freeaddrinfo(gres);
+		freeaddrinfo(res0);
 	}
 
 	/*