dhcpcd-discuss

Didn't spot that.
Try this one insted.

On 20/08/2020 18:17, Shyamlee Badole wrote:
> Hey,
>
> Thank You for sending the patch.
> I've tested this patch (version 7.0.0), but the issue is still reproducible.
>
> The option that is given in dhcpcd.conf is lastlease and not lastleaseextend.
> Could this be the cause since in dhcp_expire() we are checking for the latter as 
> follows:
> if (ifp->options->options & DHCPCD_LASTLEASE_EXTEND)
>
> Thanks,
> Shyamlee
>
> On Thu, Aug 20, 2020 at 9:48 PM Roy Marples <roy@xxxxxxxxxxxx 
> <mailto:roy@xxxxxxxxxxxx>> wrote:
>
>     I don't maintain dhcpcd-7 anymore - many bugs have been fixed since.
>     Anyway the attached patch should work - let me know.
>
>     Roy
>
>     On 20/08/2020 17:10, Shyamlee Badole wrote:
>      > Hi,
>      >
>      > Thank You for sending the patch.
>      > Since we are using dhcpcd 7.0.0 if you have, can you please share the
>     patch for
>      > this version?
>      >
>      > Thanks,
>      > Shyamlee
>      >
>      > On Thu, Aug 20, 2020 at 8:43 PM Roy Marples <roy@xxxxxxxxxxxx
>     <mailto:roy@xxxxxxxxxxxx>
>      > <mailto:roy@xxxxxxxxxxxx <mailto:roy@xxxxxxxxxxxx>>> wrote:
>      >
>      >     On 20/08/2020 11:57, Shyamlee Badole wrote:
>      >      > Hi,
>      >      >
>      >      > I am attaching the pcap file to give you a better idea of the issue.
>      >      >
>      >      > As seen from the pcap, when the link is detected on the interface
>     (eth1),
>      >      > initially the client tried to contact the dhcp server after which it
>      >     broadcasted
>      >      > the request asking for previous lease. After that a timeout occurs
>     (eth1:
>      >     timed
>      >      > out contacting a DHCP server, using last lease)
>      >      >
>      >      > After timeout(since that router is down), the client has sent a
>     Broadcast
>      >      > DISCOVER, to which a dhcp server belonging to another network has
>     offered
>      >     an ip.
>      >      > (eth1: offered 192.168.44.6 from 192.168.44.1)
>      >      > The client is now sending REQUEST to the server(192.168.44.1)
>     using the
>      >     previous
>      >      > IP(66.170.65.115).
>      >      > This REQUEST is sent unicast to the old router gateway and the
>     client is not
>      >      > able to accept the offered ip and continuously sends the unicast
>     REQUEST.
>      >      > Since the client has already entered the Discover phase, it should
>      >     broadcast the
>      >      > request instead of unicasting to the old gateway (which is no
>     longer valid).
>      >      > If this request to accept the offer was broadcasted, it will be
>     able to
>      >     receive
>      >      > the reply from the new server.
>      >
>      >     Thanks, makes it simple to fix I hope!
>      >     Comitted this to fix:
>      >
>     https://roy.marples.name/cgit/dhcpcd.git/commit/?id=f021b552b5c53cfa785bc5f8df1c97fa8ffa9b86
>      >
>      >     Can you test it please?
>      >
>      >     Roy
>      >
diff --git a/src/dhcp.c b/src/dhcp.c
index ed1b0a6d..71f844ed 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -778,7 +778,7 @@ make_message(struct bootp **bootpm, const struct interface *ifp, uint8_t type)
 	    (type == DHCP_REQUEST &&
 	    state->addr->mask.s_addr == lease->mask.s_addr &&
 	    (state->new == NULL || IS_DHCP(state->new)) &&
-	    !(state->added & STATE_FAKE))))
+	    !(state->added & (STATE_FAKE | STATE_EXPIRED)))))
 		bootp->ciaddr = state->addr->addr.s_addr;
 
 	bootp->op = BOOTREQUEST;
@@ -1968,6 +1968,9 @@ dhcp_expire(void *arg)
 
 	logerrx("%s: DHCP lease expired", ifp->name);
 	if (ifp->options->options & DHCPCD_LASTLEASE_EXTEND) {
+		struct dhcp_state *state = D_STATE(ifp);
+
+		state->added |= STATE_EXPIRED;
 		if (dhcp_leaseextend(ifp) == 0)
 			return;
 		logerr(__func__);
@@ -2332,6 +2335,8 @@ dhcp_lastlease(void *arg)
 	loginfox("%s: timed out contacting a DHCP server, using last lease",
 	    ifp->name);
 	dhcp_bind(ifp);
+	/* Although the lease hasn't expired, we don't want to send requests from it either. */
+	state->added |= STATE_EXPIRED;
 	/* If we forked, stop here. */
 	if (ifp->ctx->options & DHCPCD_FORKED)
 		return;
diff --git a/src/ipv4.h b/src/ipv4.h
index bcd0031f..03b9ac61 100644
--- a/src/ipv4.h
+++ b/src/ipv4.h
@@ -117,6 +117,7 @@ bool inet_getroutes(struct dhcpcd_ctx *, struct rt_head *);
 
 #define STATE_ADDED		0x01
 #define STATE_FAKE		0x02
+#define STATE_EXPIRED		0x04
 
 int ipv4_deladdr(struct ipv4_addr *, int);
 struct ipv4_addr *ipv4_addaddr(struct interface *,