svn commit: r209271 - stable/7/usr.sbin/arp

[Max Laier]

Author: mlaier
Date: Thu Jun 17 20:38:18 2010
New Revision: 209271
URL: http://svn.freebsd.org/changeset/base/209271

Log:
  MFC r209063:
    Cache the last result from if_indextoname for printing.  This speeds up
    "arp -an" when using a lot of aliases (on a single interface).
  
    A better fix would include a better interface for if_indextoname than
    getting the whole address list from the kernel just to find the one
    index->name mapping.
  > Description of fields to fill in above:                     76 columns --|
  > PR:            If a GNATS PR is affected by the change.
  > Submitted by:  If someone else sent in the change.
  > Reviewed by:   If someone else reviewed your modification.
  > Approved by:   If you needed approval for this commit.
  > Obtained from: If the change is from a third party.
  > MFC after:     N [day[s]|week[s]|month[s]].  Request a reminder email.
  > Security:      Vulnerability reference (one per line) or description.
  > Empty fields above will be automatically removed.
  
  _M   arp
  M    arp/arp.c

Modified:
  stable/7/usr.sbin/arp/arp.c
Directory Properties:
  stable/7/usr.sbin/arp/   (props changed)

Modified: stable/7/usr.sbin/arp/arp.c
==============================================================================
--- stable/7/usr.sbin/arp/arp.c	Thu Jun 17 20:10:41 2010	(r209270)
+++ stable/7/usr.sbin/arp/arp.c	Thu Jun 17 20:38:18 2010	(r209271)
@@ -523,6 +523,9 @@ search(u_long addr, action_fn *action)
 /*
  * Display an arp entry
  */
+static char lifname[IF_NAMESIZE];
+static int64_t lifindex = -1;
+
 static void
 print_entry(struct sockaddr_dl *sdl,
 	struct sockaddr_inarp *addr, struct rt_msghdr *rtm)
@@ -530,7 +533,6 @@ print_entry(struct sockaddr_dl *sdl,
 	const char *host;
 	struct hostent *hp;
 	struct iso88025_sockaddr_dl_data *trld;
-	char ifname[IF_NAMESIZE];
 	int seg;
 
 	if (nflag == 0)
@@ -559,8 +561,12 @@ print_entry(struct sockaddr_dl *sdl,
 		}
 	} else
 		printf("(incomplete)");
-	if (if_indextoname(sdl->sdl_index, ifname) != NULL)
-		printf(" on %s", ifname);
+	if (sdl->sdl_index != lifindex &&
+	    if_indextoname(sdl->sdl_index, lifname) != NULL) {
+        	lifindex = sdl->sdl_index;
+		printf(" on %s", lifname);
+        } else if (sdl->sdl_index == lifindex)
+		printf(" on %s", lifname);
 	if (rtm->rtm_rmx.rmx_expire == 0)
 		printf(" permanent");
 	if (addr->sin_other & SIN_PROXY)