svn commit: r209756 - head/sbin/dhclient

[Brian Somers]

Author: brian
Date: Wed Jul  7 06:06:54 2010
New Revision: 209756
URL: http://svn.freebsd.org/changeset/base/209756

Log:
  When dhclient obtains a lease, it runs dhclient-script and expects
  it to configure the interface.  When the script is complete, dhclient
  monitors the routing socket and will terminate if its address is
  deleted or if its interface is removed or brought down.
  
  Because the routing socket is already open when dhclient-script is
  run, dhclient ignores address deletions for 10 seconds after the
  script was run.
  
  If the address that will be obtained is already configured on the
  interface before dhclient starts, and if dhclient-script takes more
  than 10 seconds (perhaps due to dhclient-*-hooks latencies), on script
  completion, dhclient will immediately and silently exit when it sees
  the RTM_DELADDR routing message resulting from the script reassigning
  the address to the interface.
  
  This change logs dhclient's reason for exiting and also changes the
  10 second timeout to be effective from completion of dhclient-script
  rather than from when it was started.
  
  We now ignore RTM_DELADDR and RTM_NEWADDR messages when the message
  contains no interface address (which should not happen) rather than
  exiting.
  
  Not reviewed by:	brooks (timeout)
  MFC after:		3 weeks

Modified:
  head/sbin/dhclient/dhclient.c

Modified: head/sbin/dhclient/dhclient.c
==============================================================================
--- head/sbin/dhclient/dhclient.c	Wed Jul  7 04:06:38 2010	(r209755)
+++ head/sbin/dhclient/dhclient.c	Wed Jul  7 06:06:54 2010	(r209756)
@@ -126,7 +126,7 @@ int		 fork_privchld(int, int);
 	    ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
 #define	ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
 
-time_t	scripttime;
+static time_t	scripttime;
 
 int
 findproto(char *cp, int n)
@@ -204,7 +204,7 @@ disassoc(void *arg)
 void
 routehandler(struct protocol *p)
 {
-	char msg[2048];
+	char msg[2048], *addr;
 	struct rt_msghdr *rtm;
 	struct if_msghdr *ifm;
 	struct ifa_msghdr *ifam;
@@ -224,13 +224,6 @@ routehandler(struct protocol *p)
 
 	switch (rtm->rtm_type) {
 	case RTM_NEWADDR:
-		/*
-		 * XXX: If someone other than us adds our address,
-		 * we should assume they are taking over from us,
-		 * delete the lease record, and exit without modifying
-		 * the interface.
-		 */
-		break;
 	case RTM_DELADDR:
 		ifam = (struct ifa_msghdr *)rtm;
 
@@ -243,7 +236,7 @@ routehandler(struct protocol *p)
 
 		sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
 		if (sa == NULL)
-			goto die;
+			break;
 
 		if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
 			error("king bula sez: len mismatch");
@@ -255,21 +248,42 @@ routehandler(struct protocol *p)
 			if (addr_eq(a, l->address))
 				break;
 
-		if (l == NULL)	/* deleted addr is not the one we set */
+		if (l == NULL)	/* added/deleted addr is not the one we set */
 			break;
-		goto die;
+
+		addr = inet_ntoa(((struct sockaddr_in *)sa)->sin_addr);
+		if (rtm->rtm_type == RTM_NEWADDR)  {
+			/*
+			 * XXX: If someone other than us adds our address,
+			 * should we assume they are taking over from us,
+			 * delete the lease record, and exit without modifying
+			 * the interface?
+			 */
+			warning("My address (%s) was re-added", addr);
+		} else {
+			warning("My address (%s) was deleted, dhclient exiting",
+			    addr);
+			goto die;
+		}
+		break;
 	case RTM_IFINFO:
 		ifm = (struct if_msghdr *)rtm;
 		if (ifm->ifm_index != ifi->index)
 			break;
-		if ((rtm->rtm_flags & RTF_UP) == 0)
+		if ((rtm->rtm_flags & RTF_UP) == 0) {
+			warning("Interface %s is down, dhclient exiting",
+			    ifi->name);
 			goto die;
+		}
 		break;
 	case RTM_IFANNOUNCE:
 		ifan = (struct if_announcemsghdr *)rtm;
 		if (ifan->ifan_what == IFAN_DEPARTURE &&
-		    ifan->ifan_index == ifi->index)
+		    ifan->ifan_index == ifi->index) {
+			warning("Interface %s is gone, dhclient exiting",
+			    ifi->name);
 			goto die;
+		}
 		break;
 	case RTM_IEEE80211:
 		ifan = (struct if_announcemsghdr *)rtm;
@@ -2110,8 +2124,6 @@ script_go(void)
 	struct buf	*buf;
 	int		 ret;
 
-	scripttime = time(NULL);
-
 	hdr.code = IMSG_SCRIPT_GO;
 	hdr.len = sizeof(struct imsg_hdr);
 
@@ -2132,6 +2144,8 @@ script_go(void)
 		error("received corrupted message");
 	buf_read(privfd, &ret, sizeof(ret));
 
+	scripttime = time(NULL);
+
 	return (ret);
 }