From: Roy Marples <roy@marples.name>
Date: Sat, 16 May 2015 20:42:05 +0000 (+0000)
Subject: Improve IN_IFF_TENTATIVE with ip sharing.
X-Git-Tag: v6.9.0~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dc1979d93275bec87c3025c995b9672ae29cb131;p=thirdparty%2Fdhcpcd.git

Improve IN_IFF_TENTATIVE with ip sharing.
---

diff --git a/arp.c b/arp.c
index d49ee1af..c53e4c7b 100644
--- a/arp.c
+++ b/arp.c
@@ -294,17 +294,19 @@ arp_probe(struct arp_state *astate)
 	arp_probe1(astate);
 }
 
-static struct arp_state *
+struct arp_state *
 arp_find(struct interface *ifp, const struct in_addr *addr)
 {
 	struct arp_state *astate;
 	struct dhcp_state *state;
 
-	state = D_STATE(ifp);
+	if ((state = D_STATE(ifp)) == NULL)
+		goto out;
 	TAILQ_FOREACH(astate, &state->arp_states, next) {
 		if (astate->addr.s_addr == addr->s_addr && astate->iface == ifp)
 			return astate;
 	}
+out:
 	errno = ESRCH;
 	return NULL;
 }
diff --git a/arp.h b/arp.h
index 83422fe1..5e513b29 100644
--- a/arp.h
+++ b/arp.h
@@ -73,6 +73,7 @@ struct arp_state *arp_new(struct interface *, const struct in_addr *);
 void arp_cancel(struct arp_state *);
 void arp_free(struct arp_state *);
 void arp_free_but(struct arp_state *);
+struct arp_state *arp_find(struct interface *, const struct in_addr *);
 void arp_close(struct interface *);
 
 void arp_handleifa(int, struct interface *, const struct in_addr *, int);
diff --git a/dhcp.c b/dhcp.c
index 9280eb37..afcef4fb 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -1866,6 +1866,104 @@ dhcp_rebind(void *arg)
 	send_rebind(ifp);
 }
 
+static void
+dhcp_arp_probed(struct arp_state *astate)
+{
+	struct dhcp_state *state;
+	struct if_options *ifo;
+
+	/* We didn't find a profile for this
+	 * address or hwaddr, so move to the next
+	 * arping profile */
+	state = D_STATE(astate->iface);
+	ifo = astate->iface->options;
+	if (state->arping_index < ifo->arping_len) {
+		if (++state->arping_index < ifo->arping_len) {
+			astate->addr.s_addr =
+			    ifo->arping[state->arping_index - 1];
+			arp_probe(astate);
+		}
+		dhcpcd_startinterface(astate->iface);
+		return;
+	}
+	dhcp_close(astate->iface);
+	eloop_timeout_delete(astate->iface->ctx->eloop, NULL, astate->iface);
+#ifdef IN_IFF_TENTATIVE
+	ipv4_finaliseaddr(astate->iface);
+	arp_close(astate->iface);
+#else
+	dhcp_bind(astate->iface, astate);
+#endif
+}
+
+static void
+dhcp_arp_conflicted(struct arp_state *astate, const struct arp_msg *amsg)
+{
+	struct dhcp_state *state;
+	struct if_options *ifo;
+
+	state = D_STATE(astate->iface);
+	ifo = astate->iface->options;
+	if (state->arping_index &&
+	    state->arping_index <= ifo->arping_len &&
+	    amsg &&
+	    (amsg->sip.s_addr == ifo->arping[state->arping_index - 1] ||
+	    (amsg->sip.s_addr == 0 &&
+	    amsg->tip.s_addr == ifo->arping[state->arping_index - 1])))
+	{
+		char buf[HWADDR_LEN * 3];
+
+		astate->failed.s_addr = ifo->arping[state->arping_index - 1];
+		arp_report_conflicted(astate, amsg);
+		hwaddr_ntoa(amsg->sha, astate->iface->hwlen, buf, sizeof(buf));
+		if (dhcpcd_selectprofile(astate->iface, buf) == -1 &&
+		    dhcpcd_selectprofile(astate->iface,
+		        inet_ntoa(astate->failed)) == -1)
+		{
+			/* We didn't find a profile for this
+			 * address or hwaddr, so move to the next
+			 * arping profile */
+			dhcp_arp_probed(astate);
+			return;
+		}
+		dhcp_close(astate->iface);
+		arp_close(astate->iface);
+		eloop_timeout_delete(astate->iface->ctx->eloop, NULL,
+		    astate->iface);
+		dhcpcd_startinterface(astate->iface);
+	}
+
+	/* RFC 2131 3.1.5, Client-server interaction
+	 * NULL amsg means IN_IFF_DUPLICATED */
+	if (amsg == NULL || (state->offer &&
+	    (amsg->sip.s_addr == state->offer->yiaddr ||
+	    (amsg->sip.s_addr == 0 &&
+	    amsg->tip.s_addr == state->offer->yiaddr))))
+	{
+#ifdef IN_IFF_DUPLICATED
+		struct ipv4_addr *ia;
+#endif
+
+		if (amsg)
+			astate->failed.s_addr = state->offer->yiaddr;
+		else
+			astate->failed = astate->addr;
+		arp_report_conflicted(astate, amsg);
+		unlink(state->leasefile);
+		if (!state->lease.frominfo)
+			dhcp_decline(astate->iface);
+#ifdef IN_IFF_DUPLICATED
+		ia = ipv4_iffindaddr(astate->iface, &astate->addr, NULL);
+		if (ia)
+			ipv4_deladdr(astate->iface, &ia->addr, &ia->net);
+#endif
+		eloop_timeout_delete(astate->iface->ctx->eloop, NULL,
+		    astate->iface);
+		eloop_timeout_add_sec(astate->iface->ctx->eloop,
+		    DHCP_RAND_MAX, dhcp_discover, astate->iface);
+	}
+}
+
 void
 dhcp_bind(struct interface *ifp, struct arp_state *astate)
 {
@@ -1876,6 +1974,9 @@ dhcp_bind(struct interface *ifp, struct arp_state *astate)
 
 	if (state->state == DHS_BOUND)
 		goto applyaddr;
+#ifdef IN_IFF_TENTATIVE
+	state->added |= STATE_TENTATIVE;
+#endif
 	state->reason = NULL;
 	free(state->old);
 	state->old = state->new;
@@ -1993,6 +2094,16 @@ dhcp_bind(struct interface *ifp, struct arp_state *astate)
 			    "%s: write_lease: %m", __func__);
 
 applyaddr:
+#ifdef IN_IFF_TENTATIVE
+	if (astate == NULL) {
+		astate = arp_new(ifp, &lease->addr);
+		if (astate) {
+			astate->probed_cb = dhcp_arp_probed;
+			astate->conflicted_cb = dhcp_arp_conflicted;
+		}
+	}
+#endif
+
 	ipv4_applyaddr(ifp);
 	if (ifo->options & DHCPCD_ARP &&
 	    !(ifp->ctx->options & DHCPCD_FORKED))
@@ -2348,104 +2459,6 @@ whitelisted_ip(const struct if_options *ifo, in_addr_t addr)
 	return 0;
 }
 
-static void
-dhcp_arp_probed(struct arp_state *astate)
-{
-	struct dhcp_state *state;
-	struct if_options *ifo;
-
-	/* We didn't find a profile for this
-	 * address or hwaddr, so move to the next
-	 * arping profile */
-	state = D_STATE(astate->iface);
-	ifo = astate->iface->options;
-	if (state->arping_index < ifo->arping_len) {
-		if (++state->arping_index < ifo->arping_len) {
-			astate->addr.s_addr =
-			    ifo->arping[state->arping_index - 1];
-			arp_probe(astate);
-		}
-		dhcpcd_startinterface(astate->iface);
-		return;
-	}
-	dhcp_close(astate->iface);
-	eloop_timeout_delete(astate->iface->ctx->eloop, NULL, astate->iface);
-#ifdef IN_IFF_TENTATIVE
-	ipv4_finaliseaddr(astate->iface);
-	arp_close(astate->iface);
-#else
-	dhcp_bind(astate->iface, astate);
-#endif
-}
-
-static void
-dhcp_arp_conflicted(struct arp_state *astate, const struct arp_msg *amsg)
-{
-	struct dhcp_state *state;
-	struct if_options *ifo;
-
-	state = D_STATE(astate->iface);
-	ifo = astate->iface->options;
-	if (state->arping_index &&
-	    state->arping_index <= ifo->arping_len &&
-	    amsg &&
-	    (amsg->sip.s_addr == ifo->arping[state->arping_index - 1] ||
-	    (amsg->sip.s_addr == 0 &&
-	    amsg->tip.s_addr == ifo->arping[state->arping_index - 1])))
-	{
-		char buf[HWADDR_LEN * 3];
-
-		astate->failed.s_addr = ifo->arping[state->arping_index - 1];
-		arp_report_conflicted(astate, amsg);
-		hwaddr_ntoa(amsg->sha, astate->iface->hwlen, buf, sizeof(buf));
-		if (dhcpcd_selectprofile(astate->iface, buf) == -1 &&
-		    dhcpcd_selectprofile(astate->iface,
-		        inet_ntoa(astate->failed)) == -1)
-		{
-			/* We didn't find a profile for this
-			 * address or hwaddr, so move to the next
-			 * arping profile */
-			dhcp_arp_probed(astate);
-			return;
-		}
-		dhcp_close(astate->iface);
-		arp_close(astate->iface);
-		eloop_timeout_delete(astate->iface->ctx->eloop, NULL,
-		    astate->iface);
-		dhcpcd_startinterface(astate->iface);
-	}
-
-	/* RFC 2131 3.1.5, Client-server interaction
-	 * NULL amsg means IN_IFF_DUPLICATED */
-	if (amsg == NULL || (state->offer &&
-	    (amsg->sip.s_addr == state->offer->yiaddr ||
-	    (amsg->sip.s_addr == 0 &&
-	    amsg->tip.s_addr == state->offer->yiaddr))))
-	{
-#ifdef IN_IFF_DUPLICATED
-		struct ipv4_addr *ia;
-#endif
-
-		if (amsg)
-			astate->failed.s_addr = state->offer->yiaddr;
-		else
-			astate->failed = astate->addr;
-		arp_report_conflicted(astate, amsg);
-		unlink(state->leasefile);
-		if (!state->lease.frominfo)
-			dhcp_decline(astate->iface);
-#ifdef IN_IFF_DUPLICATED
-		ia = ipv4_iffindaddr(astate->iface, &astate->addr, NULL);
-		if (ia)
-			ipv4_deladdr(astate->iface, &ia->addr, &ia->net);
-#endif
-		eloop_timeout_delete(astate->iface->ctx->eloop, NULL,
-		    astate->iface);
-		eloop_timeout_add_sec(astate->iface->ctx->eloop,
-		    DHCP_RAND_MAX, dhcp_discover, astate->iface);
-	}
-}
-
 static void
 dhcp_handledhcp(struct interface *ifp, struct dhcp_message **dhcpp,
     const struct in_addr *from)
@@ -2763,18 +2776,7 @@ dhcp_handledhcp(struct interface *ifp, struct dhcp_message **dhcpp,
 	eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp);
 	astate = NULL;
 
-#ifdef IN_IFF_TENTATIVE
-	addr.s_addr = state->offer->yiaddr;
-	astate = arp_new(ifp, &addr);
-	if (astate) {
-		astate->probed_cb = dhcp_arp_probed;
-		astate->conflicted_cb = dhcp_arp_conflicted;
-		/* No need to start the probe as we'll
-		 * listen to the kernel stating DAD or not and
-		 * that action look look for our ARP state  for
-		 * what to do. */
-	}
-#else
+#ifndef IN_IFF_TENTATIVE
 	if (ifo->options & DHCPCD_ARP
 	    && state->addr.s_addr != state->offer->yiaddr)
 	{
diff --git a/dhcpcd.c b/dhcpcd.c
index 84036264..cb07e88d 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -669,7 +669,8 @@ dhcpcd_handlecarrier(struct dhcpcd_ctx *ctx, int carrier, unsigned int flags,
 			script_runreason(ifp, "NOCARRIER");
 #ifdef NOCARRIER_PRESERVE_IP
 			arp_close(ifp);
-			ipv4_buildroutes(ifp->ctx);
+			if_sortinterfaces(ctx);
+			ipv4_preferanother(ifp);
 			ipv6nd_expire(ifp, 0);
 #else
 			dhcpcd_drop(ifp, 0);
diff --git a/ipv4.c b/ipv4.c
index f73e4097..9fba88a7 100644
--- a/ipv4.c
+++ b/ipv4.c
@@ -750,6 +750,7 @@ ipv4_deladdr(struct interface *ifp,
 	int r;
 	struct ipv4_state *state;
 	struct ipv4_addr *ap;
+	struct arp_state *astate;
 
 	logger(ifp->ctx, LOG_DEBUG, "%s: deleting IP address %s/%d",
 	    ifp->name, inet_ntoa(*addr), inet_ntocidr(*net));
@@ -759,15 +760,8 @@ ipv4_deladdr(struct interface *ifp,
 	    errno != ENODEV)
 		logger(ifp->ctx, LOG_ERR, "%s: %s: %m", ifp->name, __func__);
 
-	dstate = D_STATE(ifp);
-	if (dstate &&
-	    dstate->addr.s_addr == addr->s_addr &&
-	    dstate->net.s_addr == net->s_addr)
-	{
-		dstate->added = 0;
-		dstate->addr.s_addr = 0;
-		dstate->net.s_addr = 0;
-	}
+	if ((astate = arp_find(ifp, addr)) != NULL)
+		arp_free(astate);
 
 	state = IPV4_STATE(ifp);
 	TAILQ_FOREACH(ap, &state->addrs, next) {
@@ -779,6 +773,18 @@ ipv4_deladdr(struct interface *ifp,
 			break;
 		}
 	}
+
+	/* Have to do this last incase the function arguments
+	 * were these very pointers. */
+	dstate = D_STATE(ifp);
+	if (dstate &&
+	    dstate->addr.s_addr == addr->s_addr &&
+	    dstate->net.s_addr == net->s_addr)
+	{
+		dstate->added = 0;
+		dstate->addr.s_addr = 0;
+		dstate->net.s_addr = 0;
+	}
 	return r;
 }
 
@@ -822,6 +828,7 @@ ipv4_addaddr(struct interface *ifp, const struct dhcp_lease *lease)
 {
 	struct ipv4_state *state;
 	struct ipv4_addr *ia;
+	struct dhcp_state *dstate;
 
 	if ((state = ipv4_getstate(ifp)) == NULL) {
 		logger(ifp->ctx, LOG_ERR, "%s: ipv4_getstate: %m", __func__);
@@ -859,6 +866,17 @@ ipv4_addaddr(struct interface *ifp, const struct dhcp_lease *lease)
 	ia->addr_flags = IN_IFF_TENTATIVE;
 #endif
 	TAILQ_INSERT_TAIL(&state->addrs, ia, next);
+
+	dstate = D_STATE(ifp);
+#ifdef IN_IFF_TENTATIVE
+	dstate->added |= STATE_ADDED;
+#else
+	dstate->added = STATE_ADDED;
+#endif
+	dstate->defend = 0;
+	dstate->addr.s_addr = lease->addr.s_addr;
+	dstate->net.s_addr = lease->net.s_addr;
+
 	return 0;
 }
 
@@ -891,13 +909,45 @@ ipv4_finaliseaddr(struct interface *ifp)
 	    ipv4_iffindaddr(ifp, &lease->addr, NULL))
 		delete_address(ifp);
 
-	state->added = STATE_ADDED;
-	state->defend = 0;
-	state->addr.s_addr = lease->addr.s_addr;
-	state->net.s_addr = lease->net.s_addr;
+	state->added &= ~(STATE_FAKE | STATE_TENTATIVE);
 	ipv4_finalisert(ifp);
 }
 
+int
+ipv4_preferanother(struct interface *ifp)
+{
+	struct dhcp_state *state = D_STATE(ifp), *nstate;
+	struct interface *ifn;
+	int preferred;
+
+	preferred = 0;
+	if (!state->added)
+		goto out;
+
+	TAILQ_FOREACH(ifn, ifp->ctx->ifaces, next) {
+		if (ifn == ifp || strcmp(ifn->name, ifp->name) == 0)
+			break; /* We are already the most preferred */
+		nstate = D_STATE(ifn);
+		if (nstate && !nstate->added &&
+		    nstate->lease.addr.s_addr == state->addr.s_addr)
+		{
+			preferred = 1;
+			delete_address(ifp);
+			if (ifn->options->options & DHCPCD_ARP)
+				dhcp_bind(ifn, NULL);
+			else {
+				ipv4_addaddr(ifn, &nstate->lease);
+				nstate->added = STATE_ADDED;
+			}
+			break;
+		}
+	}
+
+out:
+	ipv4_buildroutes(ifp->ctx);
+	return preferred;
+}
+
 void
 ipv4_applyaddr(void *arg)
 {
@@ -914,38 +964,15 @@ ipv4_applyaddr(void *arg)
 	dhcp = state->new;
 	lease = &state->lease;
 
+	if_sortinterfaces(ifp->ctx);
 	if (dhcp == NULL) {
 		if ((ifo->options & (DHCPCD_EXITING | DHCPCD_PERSISTENT)) !=
 		    (DHCPCD_EXITING | DHCPCD_PERSISTENT))
 		{
-			if (state->added) {
-				struct in_addr addr;
-
-				addr = state->addr;
+			if (state->added && !ipv4_preferanother(ifp)) {
 				delete_address(ifp);
-				TAILQ_FOREACH(ifn, ifp->ctx->ifaces, next) {
-					if (ifn == ifp ||
-					    strcmp(ifn->name, ifp->name) == 0)
-						continue;
-					nstate = D_STATE(ifn);
-					if (nstate && !nstate->added &&
-					    nstate->addr.s_addr == addr.s_addr)
-					{
-						if (ifn->options->options &
-						    DHCPCD_ARP)
-						{
-							dhcp_bind(ifn, NULL);
-						} else {
-							ipv4_addaddr(ifn,
-							    &nstate->lease);
-							nstate->added =
-							    STATE_ADDED;
-						}
-						break;
-					}
-				}
+				ipv4_buildroutes(ifp->ctx);
 			}
-			ipv4_buildroutes(ifp->ctx);
 			script_runreason(ifp, state->reason);
 		} else
 			ipv4_buildroutes(ifp->ctx);
@@ -953,29 +980,30 @@ ipv4_applyaddr(void *arg)
 	}
 
 	/* Ensure only one interface has the address */
+	r = 0;
 	TAILQ_FOREACH(ifn, ifp->ctx->ifaces, next) {
-		if (ifn == ifp || strcmp(ifn->name, ifp->name) == 0)
+		if (ifn == ifp || strcmp(ifn->name, ifp->name) == 0) {
+			r = 1; /* past ourselves */
 			continue;
+		}
 		nstate = D_STATE(ifn);
 		if (nstate && nstate->added &&
 		    nstate->addr.s_addr == lease->addr.s_addr)
 		{
-			if (ifn->metric <= ifp->metric) {
+			if (r == 0) {
 				logger(ifp->ctx, LOG_INFO,
 				    "%s: preferring %s on %s",
 				    ifp->name,
 				    inet_ntoa(lease->addr),
 				    ifn->name);
-				state->addr.s_addr = lease->addr.s_addr;
-				state->net.s_addr = lease->net.s_addr;
-				ipv4_finalisert(ifp);
+				state->added &= ~STATE_TENTATIVE;
+				return;
 			}
 			logger(ifp->ctx, LOG_INFO, "%s: preferring %s on %s",
 			    ifn->name,
 			    inet_ntoa(lease->addr),
 			    ifp->name);
 			ipv4_deladdr(ifn, &nstate->addr, &nstate->net);
-			nstate->added = 0;
 			break;
 		}
 	}
diff --git a/ipv4.h b/ipv4.h
index 08b1c213..76c32c66 100644
--- a/ipv4.h
+++ b/ipv4.h
@@ -80,11 +80,13 @@ int ipv4_addrexists(struct dhcpcd_ctx *, const struct in_addr *);
 
 #define STATE_ADDED		0x01
 #define STATE_FAKE		0x02
+#define STATE_TENTATIVE		0x04
 
 void ipv4_buildroutes(struct dhcpcd_ctx *);
 void ipv4_finaliseaddr(struct interface *);
 int ipv4_deladdr(struct interface *ifp, const struct in_addr *,
     const struct in_addr *);
+int ipv4_preferanother(struct interface *ifp);
 void ipv4_applyaddr(void *);
 int ipv4_handlert(struct dhcpcd_ctx *, int, struct rt *);
 void ipv4_freerts(struct rt_head *);