dnsmasq/bugfix-allow-binding-mac-with-ipv6.patch

From 53e1a09a06e11317bbde0e236837e5daa8d40593 Mon Sep 17 00:00:00 2001
From: liaichun <liaichun@huawei.com>
Date: Mon, 20 Apr 2020 16:06:51 +0800
---
 src/dnsmasq.c |  1 +
 src/dnsmasq.h |  4 +++-
 src/option.c  |  3 +++
 src/rfc3315.c | 35 ++++++++++++++++++++++++++++++++++-
 4 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/src/dnsmasq.c b/src/dnsmasq.c
index 5d64ceb..04c3be2 100644
--- a/src/dnsmasq.c
+++ b/src/dnsmasq.c
@@ -281,6 +281,7 @@ int main (int argc, char **argv)
     {
       daemon->doing_ra = option_bool(OPT_RA);
       
+      daemon->bind_mac_with_ip6 = option_bool(OPT_BIND_MAC_IP6);
       for (context = daemon->dhcp6; context; context = context->next)
 	{
 	  if (context->flags & CONTEXT_DHCP)
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index e455c3f..ef32f06 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -282,7 +282,8 @@ struct event_desc {
 #define OPT_NO_IDENT       70
 #define OPT_CACHE_RR       71
 #define OPT_LOCALHOST_SERVICE  72
-#define OPT_LAST           73
+#define OPT_BIND_MAC_IP6   73
+#define OPT_LAST           74
 
 #define OPTION_BITS (sizeof(unsigned int)*8)
 #define OPTION_SIZE ( (OPT_LAST/OPTION_BITS)+((OPT_LAST%OPTION_BITS)!=0) )
@@ -1211,6 +1212,7 @@ extern struct daemon {
   int override;
   int enable_pxe;
   int doing_ra, doing_dhcp6;
+  int bind_mac_with_ip6;
   struct dhcp_netid_list *dhcp_ignore, *dhcp_ignore_names, *dhcp_gen_names; 
   struct dhcp_netid_list *force_broadcast, *bootp_dynamic;
   struct hostsfile *dhcp_hosts_file, *dhcp_opts_file;
diff --git a/src/option.c b/src/option.c
index f4ff7c0..c36bf63 100644
--- a/src/option.c
+++ b/src/option.c
@@ -192,6 +192,7 @@ struct myoption {
 #define LOPT_NO_DHCP4      383
 #define LOPT_MAX_PROCS     384
 #define LOPT_DNSSEC_LIMITS 385
+#define LOPT_BIND_MAC_IP6  386
 
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
@@ -388,6 +389,7 @@ static const struct myoption opts[] =
     { "use-stale-cache", 2, 0 , LOPT_STALE_CACHE },
     { "no-ident", 0, 0, LOPT_NO_IDENT },
     { "max-tcp-connections", 1, 0, LOPT_MAX_PROCS },
+    { "bind-mac-with-ip6", 0, 0 , LOPT_BIND_MAC_IP6 },
     { NULL, 0, 0, 0 }
   };
 
@@ -591,6 +593,7 @@ static struct {
   { LOPT_NO_IDENT, OPT_NO_IDENT, NULL, gettext_noop("Do not add CHAOS TXT records."), NULL },
   { LOPT_CACHE_RR, ARG_DUP, "<RR-type>", gettext_noop("Cache this DNS resource record type."), NULL },
   { LOPT_MAX_PROCS, ARG_ONE, "<integer>", gettext_noop("Maximum number of concurrent tcp connections."), NULL },
+  { LOPT_BIND_MAC_IP6, OPT_BIND_MAC_IP6, NULL, gettext_noop("Bind mac with ipv6 address. This is an experimental feature and it conflicts with rfc3315."), NULL },
   { 0, 0, NULL, NULL, NULL }
 }; 
 
diff --git a/src/rfc3315.c b/src/rfc3315.c
index 400d939..004ebb8 100644
--- a/src/rfc3315.c
+++ b/src/rfc3315.c
@@ -49,6 +49,7 @@ static void end_ia(int t1cntr, unsigned int min_time, int do_fuzz);
 static void mark_context_used(struct state *state, struct in6_addr *addr);
 static void mark_config_used(struct dhcp_context *context, struct in6_addr *addr);
 static int check_address(struct state *state, struct in6_addr *addr);
+static int check_and_try_preempte_address(struct state *state, struct in6_addr *addr, time_t now, struct dhcp_config *config);
 static int config_valid(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr, struct state *state, time_t now);
 static struct addrlist *config_implies(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr);
 static void add_address(struct state *state, struct dhcp_context *context, unsigned int lease_time, void *ia_option, 
@@ -723,7 +724,8 @@ static int dhcp6_no_relay(struct state *state, int msg_type, unsigned char *inbu
 	    for (c = state->context; c; c = c->current) 
 	      if (!(c->flags & CONTEXT_CONF_USED) &&
 		  match_netid(c->filter, solicit_tags, plain_range) &&
-		  config_valid(config, c, &addr, state, now))
+		  config_valid(config, c, &addr, state, now) &&
+                  check_and_try_preempte_address(state, &addr, now, config))
 		{
 		  mark_config_used(state->context, &addr);
 		  if (have_config(config, CONFIG_TIME))
@@ -1313,6 +1315,37 @@ static int dhcp6_no_relay(struct state *state, int msg_type, unsigned char *inbu
 
 }
 
+static int check_and_try_preempte_address(struct state *state, struct in6_addr *addr, time_t now, struct dhcp_config *config)
+{
+  struct dhcp_lease *lease;
+
+  if (!(lease = lease6_find_by_addr(addr, 128, 0)))
+  {
+    return 1;
+  }
+
+
+  if(daemon->bind_mac_with_ip6) {
+    // break rfc3315 here
+    // bind mac address with a lease
+    if ((state->mac) && !(config->flags & CONFIG_CLID) &&
+      config_has_mac(config, state->mac, state->mac_len, state->mac_type)) {
+      lease_prune(lease, now);
+      return 1;
+    }
+  }
+
+  // what rfc3315 do
+  if (lease->clid_len != state->clid_len ||
+      memcmp(lease->clid, state->clid, state->clid_len) != 0 ||
+      lease->iaid != state->iaid)
+   {
+   return 0;
+   }
+
+  return 1;
+}
+
 static struct dhcp_netid *add_options(struct state *state, int do_refresh)  
 {
   void *oro;
-- 
2.33.0