dnsmasq: backport latest pre2.81 patches

f52bb5b fix previous commit
18eac67 Fix entries in /etc/hosts disabling static leases.
f8c77ed Fix removal of DHCP_CLIENT_MAC options from DHCPv6 relay replies.
4bf62f6 Tidy cache_blockdata_free()
9c0d445 Fix e7bfd556c079c8b5e7425aed44abc35925b24043 to actually work.
2896e24 Check for not(DS or DNSKEY) in is_outdated_cname_pointer()
a90f09d Fix crash freeing negative SRV cache entries.
5b99eae Cache SRV records.
2daca52 Fix typo in ra-param man page section.
2c59473 File logic bug in cache-marshalling code. Introduced a couple of commits back.
cc921df Remove nested struct/union in cache records and all_addr.
ab194ed Futher address union tidying.
65a01b7 Tidy address-union handling: move class into explicit argument.
bde4647 Tidy all_addr union, merge log and rcode fields.
e7bfd55 Alter DHCP address selection after DECLINE in consec-addr mode. Avoid offering the same address after a recieving a DECLINE message to stop an infinite protocol loop. This has long been done in default address allocation mode: this adds similar behaviour when allocaing addresses consecutively.

The most relevant fix for openwrt is 18eac67 (& my own local f52bb5b
which fixes a missing bracket silly) To quote the patch:

It is possible for a config entry to have one address family specified by a
dhcp-host directive and the other added from /etc/hosts. This is especially
common on OpenWrt because it uses odhcpd for DHCPv6 and IPv6 leases are
imported into dnsmasq via a hosts file.

To handle this case there need to be separate *_HOSTS flags for IPv4 and IPv6.
Otherwise when the hosts file is reloaded it will clear the CONFIG_ADDR(6) flag
which was set by the dhcp-host directive.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

1 files changed, 57 insertions, 0 deletions

diff --git a/package/network/services/dnsmasq/patches/0017-Alter-DHCP-address-selection-after-DECLINE-in-consec.patch b/package/network/services/dnsmasq/patches/0017-Alter-DHCP-address-selection-after-DECLINE-in-consec.patch
new file mode 100644
index 0000000000..ef8b78a920
--- /dev/null
+++ b/package/network/services/dnsmasq/patches/0017-Alter-DHCP-address-selection-after-DECLINE-in-consec.patch
@@ -0,0 +1,57 @@
+From e7bfd556c079c8b5e7425aed44abc35925b24043 Mon Sep 17 00:00:00 2001
+From: Simon Kelley <simon@thekelleys.org.uk>
+Date: Mon, 31 Dec 2018 20:51:15 +0000
+Subject: [PATCH 17/30] Alter DHCP address selection after DECLINE in
+ consec-addr mode. Avoid offering the same address after a recieving a DECLINE
+ message to stop an infinite protocol loop. This has long been done in default
+ address allocation mode: this adds similar behaviour when allocaing addresses
+ consecutively.
+
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ src/dhcp.c  | 13 +++++++++++++
+ src/dhcp6.c | 11 +++++++++--
+ 2 files changed, 22 insertions(+), 2 deletions(-)
+
+--- a/src/dhcp.c
++++ b/src/dhcp.c
+@@ -754,6 +754,19 @@ int address_allocate(struct dhcp_context
+ 	      if (addr.s_addr == d->router.s_addr)
+ 		break;
+ 
++	    /* in consec-ip mode, skip addresses equal to
++	       the number of addresses rejected by clients. This
++	       should avoid the same client being offered the same
++	       address after it has rjected it. */
++	    if (option_bool(OPT_CONSEC_ADDR))
++	      {
++		if (c->addr_epoch)
++		  {
++		    c->addr_epoch--;
++		    d = context; /* d non-NULL skips the address. */
++		  }
++	      }
++	    
+ 	    /* Addresses which end in .255 and .0 are broken in Windows even when using 
+ 	       supernetting. ie dhcp-range=192.168.0.1,192.168.1.254,255,255,254.0
+ 	       then 192.168.0.255 is a valid IP address, but not for Windows as it's
+--- a/src/dhcp6.c
++++ b/src/dhcp6.c
+@@ -431,8 +431,15 @@ struct dhcp_context *address6_allocate(s
+       else
+ 	{ 
+ 	  if (!temp_addr && option_bool(OPT_CONSEC_ADDR))
+-	    /* seed is largest extant lease addr in this context */
+-	    start = lease_find_max_addr6(c) + serial;
++	    {
++	      /* seed is largest extant lease addr in this context,
++		 skip addresses equal to the number of addresses rejected
++		 by clients. This should avoid the same client being offered the same
++		 address after it has rjected it. */
++	      start = lease_find_max_addr6(c) + serial + c->addr_epoch;
++	      if (c->addr_epoch)
++		c->addr_epoch--;
++	    }
+ 	  else
+ 	    {
+ 	      u64 range = 1 + addr6part(&c->end6) - addr6part(&c->start6);