Use sock_addr_validate()

We want to check that the addresses are syntactically valid before
spiped daemonizes.

It's not strictly necessary for spipe, but we might as well check it so
that we can produce a usage() if necessary.

Suggested by:	Ross Richardson

spipe/main.c

@@ -13,6 +13,7 @@
 #include "graceful_shutdown.h"
 #include "parsenum.h"
 #include "sock.h"
+#include "sock_util.h"
 #include "warnp.h"
 
 #include "proto_conn.h"
@@ -221,7 +222,9 @@ main(int argc, char * argv[])
 		usage();
 	if (!(opt_o > 0.0))
 		usage();
-	if (opt_t == NULL)
+	if (sock_addr_validate(opt_t))
+		usage();
+	if (opt_b && sock_addr_validate(opt_b))
 		usage();
 
 	/* Initialize the "events & threads" cookie. */

spiped/main.c

@@ -13,6 +13,7 @@
 #include "parsenum.h"
 #include "setuidgid.h"
 #include "sock.h"
+#include "sock_util.h"
 #include "warnp.h"
 
 #include "dispatch.h"
@@ -239,9 +240,11 @@ main(int argc, char * argv[])
 		usage();
 	if ((opt_r != 60.0) && opt_R)
 		usage();
-	if (opt_s == NULL)
+	if (sock_addr_validate(opt_s))
 		usage();
-	if (opt_t == NULL)
+	if (sock_addr_validate(opt_t))
+		usage();
+	if (opt_b && sock_addr_validate(opt_b))
 		usage();
 
 	/*