From: Roy Marples <roy@marples.name>
Date: Fri, 7 Aug 2015 08:49:07 +0000 (+0000)
Subject: Add IPv4LL subnet routes like the kernel does.
X-Git-Tag: v6.9.2~12
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f3dae6c2057278ff9bdb1b4eec1afb386856385;p=thirdparty%2Fdhcpcd.git

Add IPv4LL subnet routes like the kernel does.
Build the routing table before applying routes, fixes [a3de5dcae1].
---

diff --git a/if-bsd.c b/if-bsd.c
index f5ffe740..4a6a918f 100644
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -81,6 +81,7 @@
 #include "if.h"
 #include "if-options.h"
 #include "ipv4.h"
+#include "ipv4ll.h"
 #include "ipv6.h"
 #include "ipv6nd.h"
 
@@ -508,6 +509,7 @@ int
 if_route(unsigned char cmd, const struct rt *rt)
 {
 	const struct dhcp_state *state;
+	const struct ipv4ll_state *istate;
 	union sockunion {
 		struct sockaddr sa;
 		struct sockaddr_in sin;
@@ -534,10 +536,14 @@ if_route(unsigned char cmd, const struct rt *rt)
 		ADDSU;							      \
 	}
 
-	if (cmd != RTM_DELETE)
+	if (cmd != RTM_DELETE) {
 		state = D_CSTATE(rt->iface);
-	else	/* appease GCC */
+		istate = IPV4LL_DSTATE(rt->iface);
+	} else {
+		/* appease GCC */
 		state = NULL;
+		istate = NULL;
+	}
 	memset(&rtm, 0, sizeof(rtm));
 	rtm.hdr.rtm_version = RTM_VERSION;
 	rtm.hdr.rtm_seq = 1;
@@ -554,9 +560,14 @@ if_route(unsigned char cmd, const struct rt *rt)
 	if (cmd != RTM_DELETE) {
 		rtm.hdr.rtm_addrs |= RTA_IFA | RTA_IFP;
 		/* None interface subnet routes are static. */
-		if (rt->gate.s_addr != INADDR_ANY ||
+		if ((rt->gate.s_addr != INADDR_ANY ||
 		    rt->net.s_addr != state->net.s_addr ||
-		    rt->dest.s_addr != (state->addr.s_addr & state->net.s_addr))
+		    rt->dest.s_addr !=
+		    (state->addr.s_addr & state->net.s_addr)) &&
+		    (istate == NULL ||
+		    rt->dest.s_addr !=
+		    (istate->addr.s_addr & inaddr_llmask.s_addr) ||
+		    rt->net.s_addr != inaddr_llmask.s_addr))
 			rtm.hdr.rtm_flags |= RTF_STATIC;
 		else {
 #ifdef RTF_CLONING
@@ -627,7 +638,7 @@ if_route(unsigned char cmd, const struct rt *rt)
 		}
 
 		if (rtm.hdr.rtm_addrs & RTA_IFA)
-			ADDADDR(&state->addr);
+			ADDADDR(istate == NULL ? &state->addr : &istate->addr);
 
 		if (rt->mtu) {
 			rtm.hdr.rtm_inits |= RTV_MTU;
diff --git a/if-linux.c b/if-linux.c
index 59d8f134..3829dfcc 100644
--- a/if-linux.c
+++ b/if-linux.c
@@ -80,6 +80,7 @@
 #include "dhcp.h"
 #include "if.h"
 #include "ipv4.h"
+#include "ipv4ll.h"
 #include "ipv6.h"
 #include "ipv6nd.h"
 
@@ -1335,7 +1336,8 @@ if_route(unsigned char cmd, const struct rt *rt)
 {
 	struct nlmr nlm;
 	int retval = 0;
-	struct dhcp_state *state;
+	const struct dhcp_state *state;
+	const struct ipv4ll_state *istate;
 
 	memset(&nlm, 0, sizeof(nlm));
 	nlm.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
@@ -1356,14 +1358,18 @@ if_route(unsigned char cmd, const struct rt *rt)
 	nlm.rt.rtm_family = AF_INET;
 	nlm.rt.rtm_table = RT_TABLE_MAIN;
 
-	state = D_STATE(rt->iface);
+	state = D_CSTATE(rt->iface);
+	istate = IPV4LL_CSTATE(rt->iface);
 	if (cmd == RTM_DELETE)
 		nlm.rt.rtm_scope = RT_SCOPE_NOWHERE;
 	else {
 		/* We only change route metrics for kernel routes */
-		if (rt->dest.s_addr ==
+		if ((rt->dest.s_addr ==
 		    (state->addr.s_addr & state->net.s_addr) &&
-		    rt->net.s_addr == state->net.s_addr)
+		    rt->net.s_addr == state->net.s_addr) ||
+		    (istate && rt->dest.s_addr ==
+		    (istate->addr.s_addr & inaddr_llmask.s_addr) &&
+		    rt->net.s_addr == inaddr_llmask.s_addr))
 			nlm.rt.rtm_protocol = RTPROT_KERNEL;
 		else
 			nlm.rt.rtm_protocol = RTPROT_BOOT;
@@ -1383,7 +1389,8 @@ if_route(unsigned char cmd, const struct rt *rt)
 	    &rt->dest.s_addr, sizeof(rt->dest.s_addr));
 	if (nlm.rt.rtm_protocol == RTPROT_KERNEL) {
 		add_attr_l(&nlm.hdr, sizeof(nlm), RTA_PREFSRC,
-		    &state->addr.s_addr, sizeof(state->addr.s_addr));
+		    istate == NULL ? &state->addr.s_addr : &istate->addr.s_addr,
+		    sizeof(state->addr.s_addr));
 	}
 	/* If a host route then don't add the gateway */
 	if ((cmd == RTM_ADD || cmd == RTM_CHANGE) &&
diff --git a/ipv4.c b/ipv4.c
index 022c0e78..e0b29761 100644
--- a/ipv4.c
+++ b/ipv4.c
@@ -443,7 +443,7 @@ nc_route(struct rt *ort, struct rt *nrt)
 #ifdef HAVE_ROUTE_METRIC
 	/* With route metrics, we can safely add the new route before
 	 * deleting the old route. */
-	if (if_route(RTM_ADD, nrt)  == 0) {
+	if (if_route(RTM_ADD, nrt) == 0) {
 		if (ort && if_route(RTM_DELETE, ort) == -1 && errno != ESRCH)
 			logger(nrt->iface->ctx, LOG_ERR, "if_route (DEL): %m");
 		return 0;
diff --git a/ipv4ll.c b/ipv4ll.c
index 4815df4b..9952360e 100644
--- a/ipv4ll.c
+++ b/ipv4ll.c
@@ -45,8 +45,8 @@
 #include "ipv4ll.h"
 #include "script.h"
 
-static const struct in_addr inaddr_llmask = { HTONL(LINKLOCAL_MASK) };
-static const struct in_addr inaddr_llbcast = { HTONL(LINKLOCAL_BRDC) };
+const struct in_addr inaddr_llmask = { HTONL(LINKLOCAL_MASK) };
+const struct in_addr inaddr_llbcast = { HTONL(LINKLOCAL_BRDC) };
 
 static in_addr_t
 ipv4ll_pick_addr(const struct arp_state *astate)
@@ -189,6 +189,7 @@ ipv4ll_probed(struct arp_state *astate)
 #endif
 	state->addr = astate->addr;
 	timespecclear(&state->defend);
+	if_initrt(ifp);
 	ipv4_buildroutes(ifp->ctx);
 	arp_announce(astate);
 	script_runreason(ifp, "IPV4LL");
diff --git a/ipv4ll.h b/ipv4ll.h
index 4820c143..8fdf10b4 100644
--- a/ipv4ll.h
+++ b/ipv4ll.h
@@ -30,6 +30,9 @@
 
 #include "arp.h"
 
+extern const struct in_addr inaddr_llmask;
+extern const struct in_addr inaddr_llbcast;
+
 #define LINKLOCAL_ADDR	0xa9fe0000
 #define LINKLOCAL_MASK	IN_CLASSB_NET
 #define LINKLOCAL_BRDC	(LINKLOCAL_ADDR | ~LINKLOCAL_MASK)