- Renamed the ``proxy'' modifier of the -d flag to ``pub'',

  to be consistent with the -s flag.  Updated documentation
  on what this modifier does.

- Added the ``only'' keyword to the -s and -S flags, that
  could be used to created "proxy-only" published entries.
  Previously, arp(8) created an entry of this type only
  in the absence of the route to a destination.

PR:		bin/12357
MFC after:	1 week

2 files changed, 53 insertions, 27 deletions

diff --git a/usr.sbin/arp/arp.8 b/usr.sbin/arp/arp.8
index 80fcae5..985f2ef 100644
--- a/usr.sbin/arp/arp.8
+++ b/usr.sbin/arp/arp.8
@@ -47,18 +47,18 @@
 .Fl a
 .Nm
 .Fl d Ar hostname
-.Op Cm proxy
+.Op Cm pub
 .Nm
 .Fl d
 .Fl a
 .Nm
 .Fl s Ar hostname ether_addr
 .Op Cm temp
-.Op Cm pub
+.Op Cm pub Op Cm only
 .Nm
 .Fl S Ar hostname ether_addr
 .Op Cm temp
-.Op Cm pub
+.Op Cm pub Op Cm only
 .Nm
 .Fl f Ar filename
 .Sh DESCRIPTION
@@ -86,10 +86,17 @@ A super-user may delete an entry for the host called
 with the
 .Fl d
 flag.
-The
-.Cm proxy
-keyword is sometimes required when deleting published ARP entries.
-This flag may be combined with the
+It the
+.Cm pub
+keyword is specified, only
+.Dq published
+.Tn ARP
+entry
+for this host will be deleted.
+.Pp
+Alternatively, the
+.Fl d
+flag may be combined with the
 .Fl a
 flag to delete all entries.
 .It Fl n
@@ -109,7 +116,9 @@ The entry will be permanent unless the word
 is given in the command. 
 If the word
 .Cm pub
-is given, the entry will be "published"; i.e., this system will
+is given, the entry will be
+.Dq published ;
+i.e., this system will
 act as an
 .Tn ARP
 server,
@@ -123,6 +132,16 @@ can be given as
 in which case the interfaces on this host will be examined,
 and if one of them is found to occupy the same subnet, its
 Ethernet address will be used.
+If the
+.Cm only
+keyword is also specified, this will create a
+.Dq "published (proxy only)"
+entry.
+This type of entry is created automatically if
+.Nm
+detects that the routing table entry for
+.Ar hostname
+already exists.
 .It Fl S Ar hostname ether_addr
 Is just like
 .Fl s
diff --git a/usr.sbin/arp/arp.c b/usr.sbin/arp/arp.c
index 3f9c5fc..94ca7ba 100644
--- a/usr.sbin/arp/arp.c
+++ b/usr.sbin/arp/arp.c
@@ -115,9 +115,7 @@ static int s = -1;
 #define SETFUNC(f)	{ if (func) usage(); func = (f); }
 
 int
-main(argc, argv)
-	int argc;
-	char **argv;
+main(int argc, char *argv[])
 {
 	int ch, func = 0;
 	int rtn = 0;
@@ -166,7 +164,7 @@ main(argc, argv)
 		break;
 	case F_SET:
 	case F_REPLACE:
-		if (argc < 2 || argc > 5)
+		if (argc < 2 || argc > 6)
 			usage();
 		if (func == F_REPLACE)
 			(void) delete(argv[0], NULL);
@@ -239,7 +237,7 @@ getsocket(void)
 struct	sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
 struct	sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
 struct	sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
-int	expire_time, flags, export_only, doing_proxy, found_entry;
+int	expire_time, flags, doing_proxy, proxy_only, found_entry;
 struct	{
 	struct	rt_msghdr m_rtm;
 	char	m_space[512];
@@ -264,7 +262,7 @@ set(int argc, char **argv)
 	sdl_m = blank_sdl;
 	sin_m = blank_sin;
 	sin->sin_addr.s_addr = inet_addr(host);
-	if (sin->sin_addr.s_addr == -1) {
+	if (sin->sin_addr.s_addr == INADDR_NONE) {
 		if (!(hp = gethostbyname(host))) {
 			warnx("%s: %s", host, hstrerror(h_errno));
 			return (1);
@@ -272,16 +270,21 @@ set(int argc, char **argv)
 		bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
 		    sizeof sin->sin_addr);
 	}
-	doing_proxy = flags = export_only = expire_time = 0;
+	doing_proxy = flags = proxy_only = expire_time = 0;
 	while (argc-- > 0) {
 		if (strncmp(argv[0], "temp", 4) == 0) {
-			struct timeval time;
-			gettimeofday(&time, 0);
-			expire_time = time.tv_sec + 20 * 60;
+			struct timeval tv;
+			gettimeofday(&tv, 0);
+			expire_time = tv.tv_sec + 20 * 60;
 		}
 		else if (strncmp(argv[0], "pub", 3) == 0) {
 			flags |= RTF_ANNOUNCE;
-			doing_proxy = SIN_PROXY;
+			doing_proxy = 1;
+			if (argc && strncmp(argv[1], "only", 3) == 0) {
+				proxy_only = 1;
+				sin_m.sin_other = SIN_PROXY;
+				argc--; argv++;
+			}
 		} else if (strncmp(argv[0], "trail", 5) == 0) {
 			printf("%s: Sending trailers is no longer supported\n",
 				host);
@@ -324,7 +327,7 @@ tryagain:
 			return(1);
 		}
 		sin_m.sin_other = SIN_PROXY;
-		export_only = 1;
+		proxy_only = 1;
 		goto tryagain;
 	}
 overwrite:
@@ -348,7 +351,7 @@ get(char *host)
 
 	sin_m = blank_sin;
 	sin->sin_addr.s_addr = inet_addr(host);
-	if (sin->sin_addr.s_addr == -1) {
+	if (sin->sin_addr.s_addr == INADDR_NONE) {
 		if (!(hp = gethostbyname(host)))
 			errx(1, "%s: %s", host, hstrerror(h_errno));
 		bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
@@ -376,10 +379,14 @@ delete(char *host, char *info)
 
 	getsocket();
 	sin_m = blank_sin;
-	if (info && strncmp(info, "pro", 3) == 0)
-		sin_m.sin_other = SIN_PROXY;
+	if (info) {
+		if (strncmp(info, "pub", 3) == 0)
+			sin_m.sin_other = SIN_PROXY;
+		else
+			usage();
+	}
 	sin->sin_addr.s_addr = inet_addr(host);
-	if (sin->sin_addr.s_addr == -1) {
+	if (sin->sin_addr.s_addr == INADDR_NONE) {
 		if (!(hp = gethostbyname(host))) {
 			warnx("%s: %s", host, hstrerror(h_errno));
 			return (1);
@@ -470,7 +477,7 @@ void
 print_entry(struct sockaddr_dl *sdl,
 	struct sockaddr_inarp *sin, struct rt_msghdr *rtm)
 {
-	char *host;
+	const char *host;
 	struct hostent *hp;
 	int seg;
 
@@ -567,7 +574,7 @@ usage(void)
 	fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n%s\n",
 		"usage: arp [-n] hostname",
 		"       arp [-n] -a",
-		"       arp -d hostname [proxy]",
+		"       arp -d hostname [pub]",
 		"       arp -d -a",
 		"       arp -s hostname ether_addr [temp] [pub]",
 		"       arp -S hostname ether_addr [temp] [pub]",
@@ -601,7 +608,7 @@ rtmsg(int cmd)
 		rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
 		sin_m.sin_other = 0;
 		if (doing_proxy) {
-			if (export_only)
+			if (proxy_only)
 				sin_m.sin_other = SIN_PROXY;
 			else {
 				rtm->rtm_addrs |= RTA_NETMASK;