XXX CTF for dhcpagent/dhcpinfo; support for setting MTUgce

8 files changed, 75 insertions, 6 deletions

diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpagent/Makefile b/usr/src/cmd/cmd-inet/sbin/dhcpagent/Makefile
index b52683dee2..550c2aa118 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpagent/Makefile
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpagent/Makefile
@@ -34,6 +34,7 @@ OBJS =	adopt.o agent.o async.o bound.o class_id.o defaults.o inform.o \
 	request.o script_handler.o select.o states.o util.o
 
 include ../../../Makefile.cmd
+include ../../../Makefile.ctf
 
 SRCS    = $(OBJS:%.o=%.c)
 POFILES = $(OBJS:%.o=%.po)
diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpagent/bound.c b/usr/src/cmd/cmd-inet/sbin/dhcpagent/bound.c
index 0e5d496af2..8fc093f684 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpagent/bound.c
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpagent/bound.c
@@ -455,13 +455,15 @@ void
 dhcp_bound_complete(dhcp_smach_t *dsmp)
 {
 	PKT_LIST	*ack = dsmp->dsm_ack;
+	DHCP_OPT	*mtu;
 	DHCP_OPT	*routes;
 	DHCP_OPT	*router_list;
 	int		i;
 	DHCPSTATE	oldstate;
 	dhcp_lif_t	*lif;
 	boolean_t	ignore_routes = B_FALSE, ignore_router_list = B_FALSE;
-	boolean_t	manage_classless_routes;
+	boolean_t	ignore_mtu = B_FALSE;
+	boolean_t	manage_classless_routes, manage_mtu;
 
 	/*
 	 * Do bound state entry processing only if running IPv4.  There's no
@@ -484,6 +486,7 @@ dhcp_bound_complete(dhcp_smach_t *dsmp)
 
 	manage_classless_routes = df_get_bool(dsmp->dsm_name, dsmp->dsm_isv6,
 	    DF_CLASSLESS_ROUTES);
+	manage_mtu = df_get_bool(dsmp->dsm_name, dsmp->dsm_isv6, DF_SET_MTU);
 
 	/*
 	 * Check to see if the default route or classless routes options appear
@@ -491,6 +494,9 @@ dhcp_bound_complete(dhcp_smach_t *dsmp)
 	 */
 	for (i = 0; i < dsmp->dsm_pillen; i++) {
 		switch (dsmp->dsm_pil[i]) {
+		case CD_MTU:
+			ignore_mtu = B_TRUE;
+			break;
 		case CD_ROUTER:
 			ignore_router_list = B_TRUE;
 			break;
@@ -501,8 +507,23 @@ dhcp_bound_complete(dhcp_smach_t *dsmp)
 	}
 
 	/*
-	 * XXX Set interface MTU...
+	 * If the server provides a valid MTU option, and the operator has not
+	 * disabled MTU management, configure the MTU on the interface now.
+	 * The SIOCSLIFMTU ioctl does not work for IPv4 logicals.
 	 */
+	if (manage_mtu && !ignore_mtu && strchr(lif->lif_name, ':') == NULL &&
+	    (mtu = ack->opts[CD_MTU]) != NULL &&
+	    mtu->len == sizeof (uint16_t)) {
+		uint16_t mtuval;
+
+		(void) memcpy(&mtuval, mtu->value, sizeof (mtuval));
+		mtuval = ntohs(mtuval);
+
+		if (!set_lif_mtu(lif, mtuval)) {
+			dhcpmsg(MSG_ERR, "dhcp_bound_complete: could not set "
+			    "interface MTU to %u", (uint_t)mtuval);
+		}
+	}
 
 	/*
 	 * XXX Get classless routes...
diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.c b/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.c
index 634438be1a..34e502778e 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.c
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.c
@@ -46,9 +46,8 @@ struct dhcp_default {
 };
 
 /*
- * note: keep in the same order as tunable parameter constants in defaults.h
+ * NOTE: Keep in the same order as tunable parameter constants in defaults.h
  */
-
 static struct dhcp_default defaults[] = {
 	{ "RELEASE_ON_SIGTERM",  "0",	 0,   0	  },
 	{ "IGNORE_FAILED_ARP",	 "1",	 0,   -1  },
@@ -66,6 +65,7 @@ static struct dhcp_default defaults[] = {
 	{ "DNS_DOMAINNAME",  NULL,	 0,   0	  },
 	{ "ADOPT_DOMAINNAME",	 "0",	 0,   0	  },
 	{ "CLASSLESS_ROUTES",	 "1",	 0,   0	  },
+	{ "SET_MTU",	 	 "1",	 0,   0	  }
 };
 
 
diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.h b/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.h
index b2aec7fcea..537f3551f2 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.h
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpagent/defaults.h
@@ -40,9 +40,8 @@ extern "C" {
 #endif
 
 /*
- * tunable parameters -- keep in the same order as defaults[] in defaults.c
+ * Tunable parameters -- keep in the same order as defaults[] in defaults.c
  */
-
 enum {
 	DF_RELEASE_ON_SIGTERM,	/* send RELEASE on each if upon SIGTERM */
 	_UNUSED_DF_IGNORE_FAILED_ARP,
@@ -60,6 +59,7 @@ enum {
 	DF_DNS_DOMAINNAME,	/* static domain name if not in --reqhost */
 	DF_ADOPT_DOMAINNAME,	/* adopt DHCP domain if not in --reqhost */
 	DF_CLASSLESS_ROUTES,	/* manage additional routes (option 121) */
+	DF_SET_MTU		/* set interface MTU (option 26) */
 };
 
 #define	DHCP_AGENT_DEFAULTS	"/etc/default/dhcpagent"
diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpagent/dhcpagent.dfl b/usr/src/cmd/cmd-inet/sbin/dhcpagent/dhcpagent.dfl
index e457264c4d..edee460623 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpagent/dhcpagent.dfl
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpagent/dhcpagent.dfl
@@ -23,6 +23,7 @@
 # Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 # Copyright (c) 2016-2017, Chris Fraire <cfraire@me.com>.
+# Copyright 2019, Joyent, Inc.
 #
 
 #
@@ -167,6 +168,11 @@
 #
 # CLASSLESS_ROUTES=no
 
+# XXX By default, the DHCP agent will set the MTU of the link if the MTU option
+# (26) is provided by the server.  To prevent this, uncomment the following
+# line.
+#
+# SET_MTU=no
 
 # By default, a parameter request list requesting a subnet mask (1), router
 # (3), DNS server (6), hostname (12), DNS domain (15), MTU (26), broadcast
diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.c b/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.c
index fd18717259..3e4a2dd285 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.c
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.c
@@ -438,6 +438,7 @@ insert_lif(dhcp_pif_t *pif, const char *lname, int *error)
 		lif->lif_max = 1024;
 	else
 		lif->lif_max = lifr.lifr_mtu;
+	lif->lif_mtu_orig = lif->lif_mtu = lif->lif_max;
 
 	if (ioctl(fd, SIOCGLIFADDR, &lifr) == -1) {
 		if (errno == ENXIO)
@@ -1227,6 +1228,41 @@ clear_lif_dhcp(dhcp_lif_t *lif)
 	(void) ioctl(fd, SIOCSLIFFLAGS, &lifr);
 }
 
+boolean_t
+set_lif_mtu(dhcp_lif_t *lif, uint_t mtu)
+{
+	struct lifreq lifr;
+	int fd = lif->lif_pif->pif_isv6 ? v6_sock_fd : v4_sock_fd;
+
+	if (lif->lif_mtu == mtu) {
+		/*
+		 * We set the MTU to this value already.
+		 */
+		return (B_TRUE);
+	}
+
+	(void) memset(&lifr, 0, sizeof (lifr));
+	(void) strlcpy(lifr.lifr_name, lif->lif_name, LIFNAMSIZ);
+	lifr.lifr_mtu = mtu;
+
+	if (ioctl(fd, SIOCSLIFMTU, &lifr) == -1) {
+		return (B_FALSE);
+	}
+
+	lif->lif_mtu = mtu;
+	return (B_TRUE);
+}
+
+boolean_t
+clear_lif_mtu(dhcp_lif_t *lif)
+{
+	if (lif->lif_mtu == lif->lif_mtu_orig) {
+		return (B_TRUE);
+	}
+
+	return (set_lif_mtu(lif, lif->lif_mtu_orig));
+}
+
 /*
  * set_lif_deprecated(): Set the "deprecated" flag to tell users that this
  *			 address will be going away.  As the interface is
diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.h b/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.h
index 446adfb36f..d164adf3a9 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.h
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpagent/interface.h
@@ -76,6 +76,8 @@ struct dhcp_lif_s {
 	dhcp_smach_t	*lif_smachs;	/* pointer to list of state machines */
 	dhcp_lease_t	*lif_lease;	/* backpointer to lease holding LIF */
 	uint64_t	lif_flags;	/* Interface flags (IFF_*) */
+	uint_t		lif_mtu;	/* Interface MTU */
+	uint_t		lif_mtu_orig;	/* Original interface MTU */
 	int		lif_sock_ip_fd;	/* Bound to addr.BOOTPC for src addr */
 	iu_event_id_t	lif_packet_id;	/* event packet id */
 	uint_t		lif_max;	/* maximum IP message size */
@@ -183,6 +185,8 @@ dhcp_lif_t	*attach_lif(const char *, boolean_t, int *);
 int		set_lif_dhcp(dhcp_lif_t *);
 void		set_lif_deprecated(dhcp_lif_t *);
 boolean_t	clear_lif_deprecated(dhcp_lif_t *);
+boolean_t	set_lif_mtu(dhcp_lif_t *, uint_t);
+boolean_t	clear_lif_mtu(dhcp_lif_t *);
 boolean_t	open_ip_lif(dhcp_lif_t *, in_addr_t, boolean_t);
 void		close_ip_lif(dhcp_lif_t *);
 void		lif_mark_decline(dhcp_lif_t *, const char *);
diff --git a/usr/src/cmd/cmd-inet/sbin/dhcpinfo/Makefile b/usr/src/cmd/cmd-inet/sbin/dhcpinfo/Makefile
index d97f88d796..09ec55480a 100644
--- a/usr/src/cmd/cmd-inet/sbin/dhcpinfo/Makefile
+++ b/usr/src/cmd/cmd-inet/sbin/dhcpinfo/Makefile
@@ -33,6 +33,7 @@ ROOTFS_PROG = $(PROG)
 OBJS    = $(PROG).o
 
 include ../../../Makefile.cmd
+include ../../../Makefile.ctf
 
 LDLIBS  += -ldhcpagent -ldhcputil
 LINTFLAGS += -u	# due to problems with libgen