Process the "O bit."

If the value of OtherConfigFlag changes from FALSE to TRUE, the
host should invoke the stateful autoconfiguration protocol,
requesting information.
[RFC 2462 Section 5.5.3]

Obtained from:	KAME
MFC after:	1 week

usr.sbin/rtsold/dump.c

@@ -76,6 +76,8 @@ dump_interface_status()
 		}
 		fprintf(fp, "  interface status: %s\n",
 			ifinfo->active > 0 ? "active" : "inactive");
+		fprintf(fp, "  other config: %s\n",
+		    ifinfo->otherconfig ? "on" : "off");
 		fprintf(fp, "  rtsold status: %s\n", ifstatstr[ifinfo->state]);
 		fprintf(fp, "  carrier detection: %s\n",
 			ifinfo->mediareqok ? "available" : "unavailable");

usr.sbin/rtsold/rtsol.c

@@ -35,7 +35,10 @@
 #include <sys/socket.h>
 #include <sys/uio.h>
 #include <sys/time.h>
+#include <fcntl.h>
 #include <sys/queue.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
 
 #include <net/if.h>
 #include <net/route.h>
@@ -70,6 +73,9 @@ int rssock;
 
 static struct sockaddr_in6 sin6_allrouters = {sizeof(sin6_allrouters), AF_INET6};
 
+static void call_script __P((char *, char *));
+static int safefile __P((const char *));
+
 int
 sockopen()
 {
@@ -233,6 +239,7 @@ rtsol_input(int s)
 	struct cmsghdr *cm;
 	struct in6_pktinfo *pi = NULL;
 	struct ifinfo *ifi = NULL;
+	struct nd_router_advert *nd_ra;
 	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 
 	/* get message */
@@ -330,6 +337,23 @@ rtsol_input(int s)
 			 INET6_ADDRSTRLEN),
 	       ifi->ifname, ifi->state);
 
+	nd_ra = (struct nd_router_advert *)icp;
+
+	/*
+	 * Process the "O bit."
+	 * If the value of OtherConfigFlag changes from FALSE to TRUE, the
+	 * host should invoke the stateful autoconfiguration protocol,
+	 * requesting information.
+	 * [RFC 2462 Section 5.5.3]
+	 */
+	if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) &&
+	    !ifi->otherconfig) {
+		warnmsg(LOG_DEBUG, __func__,
+		    "OtherConfigFlag on %s is turned on", ifi->ifname);
+		ifi->otherconfig = 1;
+		call_script(otherconf_script, ifi->ifname);
+	}
+
 	ifi->racnt++;
 
 	switch(ifi->state) {
@@ -343,3 +367,106 @@ rtsol_input(int s)
 		 break;
 	}
 }
+
+static void
+call_script(scriptpath, ifname)
+	char *scriptpath, *ifname;
+{
+	pid_t pid, wpid;
+
+	if (scriptpath == NULL)
+		return;
+
+	/* launch the script */
+	pid = fork();
+	if (pid < 0) {
+		warnmsg(LOG_ERR, __func__,
+		    "failed to fork: %s", strerror(errno));
+		return;
+	} else if (pid) {
+		int wstatus;
+
+		do {
+			wpid = wait(&wstatus);
+		} while (wpid != pid && wpid > 0);
+
+		if (wpid < 0)
+			warnmsg(LOG_ERR, __func__,
+			    "wait: %s", strerror(errno));
+		else {
+			warnmsg(LOG_DEBUG, __func__,
+			    "script \"%s\" terminated", scriptpath);
+		}
+	} else {
+		char *argv[3];
+		int fd;
+
+		argv[0] = scriptpath;
+		argv[1] = ifname;
+		argv[2] = NULL;
+
+		if (safefile(scriptpath)) {
+			warnmsg(LOG_ERR, __func__,
+			    "script \"%s\" cannot be executed safely",
+			    scriptpath);
+			exit(1);
+		}
+
+		if ((fd = open("/dev/null", O_RDWR)) != -1) {
+			dup2(fd, STDIN_FILENO);
+			dup2(fd, STDOUT_FILENO);
+			dup2(fd, STDERR_FILENO);
+			if (fd > STDERR_FILENO)
+				close(fd);
+		}
+
+		execv(scriptpath, argv);
+
+		warnmsg(LOG_ERR, __func__, "child: exec failed: %s",
+		    strerror(errno));
+		exit(0);
+	}
+
+	return;
+}
+
+static int
+safefile(path)
+	const char *path;
+{
+	struct stat s;
+	uid_t myuid;
+
+	/* no setuid */
+	if (getuid() != geteuid()) {
+		warnmsg(LOG_NOTICE, __func__,
+		    "setuid'ed execution not allowed\n");
+		return (-1);
+	}
+
+	if (lstat(path, &s) != 0) {
+		warnmsg(LOG_NOTICE, __func__, "lstat failed: %s",
+		    strerror(errno));
+		return (-1);
+	}
+
+	/* the file must be owned by the running uid */
+	myuid = getuid();
+	if (s.st_uid != myuid) {
+		warnmsg(LOG_NOTICE, __func__,
+		    "%s has invalid owner uid\n", path);
+		return (-1);
+	}
+
+	switch (s.st_mode & S_IFMT) {
+	case S_IFREG:
+		break;
+	default:
+		warnmsg(LOG_NOTICE, __func__,
+		    "%s is an invalid file type 0x%o\n",
+		    path, (s.st_mode & S_IFMT));
+		return (-1);
+	}
+
+	return (0);
+}

usr.sbin/rtsold/rtsold.8

@@ -40,15 +40,19 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl dDfm1
+.Op Fl O Ar script-name
 .Ar interface ...
 .Nm
 .Op Fl dDfm1
+.Op Fl O Ar script-name
 .Fl a
 .Nm rtsol
 .Op Fl dD
+.Op Fl O Ar script-name
 .Ar interface ...
 .Nm rtsol
 .Op Fl dD
+.Op Fl O Ar script-name
 .Fl a
 .\"
 .Sh DESCRIPTION
@@ -128,6 +132,21 @@ When sending a Router Solicitation on an interface,
 .Nm
 includes a Source Link-layer address option if the interface
 has a link-layer address.
+.Lp
+.Nm
+manages a per-interface parameter to detect if a separate protocol is
+needed for configuration parameters other than host's addresses.
+At the invocation time, the flag is FALSE, and becomes TRUE when
+the daemon receives a router advertisement with the OtherConfig flag
+being set.
+A script file can be specified to deal with the case
+.Pq see below .
+When
+.Nm
+start resending router solicitation messages by one of the conditions
+events,
+the daemon resets the parameter because the event may indicate a
+change on the attached link.
 .Pp
 Upon receipt of signal
 .Dv SIGUSR1 ,
@@ -178,6 +197,20 @@ Transmit Router Solicitation packets until at least one valid Router
 Advertisement packet has arrived on each
 .Ar interface ,
 then exit.
+.It Fl O Ar script-name
+Specifies a supplement script file to handle the Other Configuration
+flag of the router advertisement.
+When the flag changes from FALSE to TRUE,
+.Nm
+will invoke
+.Ar script-name
+with a single argument of the receiving interface name,
+expecting the script will then start a protocol for the other
+configuration.
+.Ar script-name
+must be the absolute path from root to the script file, be a regular
+file, and be created by the same owner who runs
+.Nm .
 .El
 .Sh DIAGNOSTICS
 .Ex -std rtsold rtsol

usr.sbin/rtsold/rtsold.c

@@ -57,6 +57,7 @@ struct ifinfo *iflist;
 struct timeval tm_max =	{0x7fffffff, 0x7fffffff};
 int aflag = 0;
 int dflag = 0;
+char *otherconf_script;
 static int log_upto = 999;
 static int fflag = 0;
 
@@ -126,9 +127,9 @@ main(argc, argv)
 	if (argv0 && argv0[strlen(argv0) - 1] != 'd') {
 		fflag = 1;
 		once = 1;
-		opts = "adD";
+		opts = "adDO:";
 	} else
-		opts = "adDfm1";
+		opts = "adDfm1O:";
 
 	while ((ch = getopt(argc, argv, opts)) != -1) {
 		switch (ch) {
@@ -150,6 +151,9 @@ main(argc, argv)
 		case '1':
 			once = 1;
 			break;
+		case 'O':
+			otherconf_script = optarg;
+			break;
 		default:
 			usage(argv0);
 			/*NOTREACHED*/
@@ -196,6 +200,11 @@ main(argc, argv)
 			setlogmask(LOG_UPTO(log_upto));
 	}
 
+	if (otherconf_script && *otherconf_script != '/') {
+		errx(1, "configuration script (%s) must be an absolute path",
+		    otherconf_script);
+	}
+
 #ifndef HAVE_ARC4RANDOM
 	/* random value initilization */
 	srandom((u_long)time(NULL));
@@ -524,6 +533,13 @@ rtsol_check_timer()
 					ifinfo->state = IFS_PROBE;
 				}
 
+				/*
+				 * If we need a probe, clear the previous
+				 * status wrt the "other" configuration.
+				 */
+				if (probe)
+					ifinfo->otherconfig = 0;
+
 				if (probe && mobile_node)
 					defrouter_probe(ifinfo->sdl->sdl_index);
 				break;

usr.sbin/rtsold/rtsold.h

@@ -40,6 +40,8 @@ struct ifinfo {
 	int probeinterval;	/* interval of probe timer(if necessary) */
 	int probetimer;		/* rest of probe timer */
 	int mediareqok;		/* wheter the IF supports SIOCGIFMEDIA */
+	int otherconfig;	/* need a separate protocol for the "other"
+				 * configuration */
 	int state;
 	int probes;
 	int dadcount;
@@ -63,6 +65,7 @@ struct ifinfo {
 /* rtsold.c */
 extern struct timeval tm_max;
 extern int dflag;
+extern char *otherconf_script;
 struct ifinfo *find_ifinfo __P((int ifindex));
 void rtsol_timer_update __P((struct ifinfo *ifinfo));
 extern void warnmsg __P((int, const char *, const char *, ...))