Add tag filtering of dhcp-host directives.

CHANGELOG

@@ -78,6 +78,9 @@ version 2.81
 	boot. Many thanks to Harald Jensås for his work on this idea and
 	earlier patches.
 
+	Add filtering by tag of --dhcp-host directives. Based on a patch
+	by Harald Jensås.
+	
 	
 version 2.80
 	Add support for RFC 4039 DHCP rapid commit. Thanks to Ashram Method

man/dnsmasq.8

@@ -975,7 +975,7 @@ is also included, as described in RFC-3775 section 7.3.
 tells dnsmasq to advertise the prefix without the on-link (aka L) bit set.
 
 .TP
-.B \-G, --dhcp-host=[<hwaddr>][,id:<client_id>|*][,set:<tag>][,<ipaddr>][,<hostname>][,<lease_time>][,ignore]
+.B \-G, --dhcp-host=[<hwaddr>][,id:<client_id>|*][,set:<tag>][tag:<tag>][,<ipaddr>][,<hostname>][,<lease_time>][,ignore]
 Specify per host parameters for the DHCP server. This allows a machine
 with a particular hardware address to be always allocated the same
 hostname, IP address and lease time. A hostname specified like this
@@ -1060,6 +1060,9 @@ ignore requests from unknown machines using
 .B --dhcp-ignore=tag:!known
 If the host matches only a \fB--dhcp-host\fP directive which cannot
 be used because it specifies an address on different subnet, the tag "known-othernet" is set.
+
+The tag:<tag> construct filters which dhcp-host directives are used. Tagged directives are used in preference to untagged ones.
+
 Ethernet addresses (but not client-ids) may have
 wildcard bytes, so for example 
 .B --dhcp-host=00:20:e0:3b:13:*,ignore 

src/dhcp-common.c

@@ -304,11 +304,12 @@ static int is_config_in_context(struct dhcp_context *context, struct dhcp_config
   return 0;
 }
 
-struct dhcp_config *find_config(struct dhcp_config *configs,
+static struct dhcp_config *find_config_match(struct dhcp_config *configs,
-				struct dhcp_context *context,
+					     struct dhcp_context *context,
-				unsigned char *clid, int clid_len,
+					     unsigned char *clid, int clid_len,
-				unsigned char *hwaddr, int hw_len, 
+					     unsigned char *hwaddr, int hw_len, 
-				int hw_type, char *hostname)
+					     int hw_type, char *hostname,
+					     struct dhcp_netid *tags, int tag_not_needed)
 {
   int count, new;
   struct dhcp_config *config, *candidate; 
@@ -320,7 +321,9 @@ struct dhcp_config *find_config(struct dhcp_config *configs,
 	{
 	  if (config->clid_len == clid_len && 
 	      memcmp(config->clid, clid, clid_len) == 0 &&
-	      is_config_in_context(context, config))
+	      is_config_in_context(context, config) &&
+	      match_netid(config->filter, tags, tag_not_needed))
+	    
 	    return config;
 	  
 	  /* dhcpcd prefixes ASCII client IDs by zero which is wrong, but we try and
@@ -328,7 +331,8 @@ struct dhcp_config *find_config(struct dhcp_config *configs,
 	     see lease_update_from_configs() */
 	  if ((!context || !(context->flags & CONTEXT_V6)) && *clid == 0 && config->clid_len == clid_len-1  &&
 	      memcmp(config->clid, clid+1, clid_len-1) == 0 &&
-	      is_config_in_context(context, config))
+	      is_config_in_context(context, config) &&
+	      match_netid(config->filter, tags, tag_not_needed))
 	    return config;
 	}
   
@@ -336,14 +340,16 @@ struct dhcp_config *find_config(struct dhcp_config *configs,
   if (hwaddr)
     for (config = configs; config; config = config->next)
       if (config_has_mac(config, hwaddr, hw_len, hw_type) &&
-	  is_config_in_context(context, config))
+	  is_config_in_context(context, config) &&
+	  match_netid(config->filter, tags, tag_not_needed))
 	return config;
   
   if (hostname && context)
     for (config = configs; config; config = config->next)
       if ((config->flags & CONFIG_NAME) && 
 	  hostname_isequal(config->hostname, hostname) &&
-	  is_config_in_context(context, config))
+	  is_config_in_context(context, config) &&
+	  match_netid(config->filter, tags, tag_not_needed))
 	return config;
 
   
@@ -352,7 +358,8 @@ struct dhcp_config *find_config(struct dhcp_config *configs,
 
   /* use match with fewest wildcard octets */
   for (candidate = NULL, count = 0, config = configs; config; config = config->next)
-    if (is_config_in_context(context, config))
+    if (is_config_in_context(context, config) &&
+	match_netid(config->filter, tags, tag_not_needed))
       for (conf_addr = config->hwaddr; conf_addr; conf_addr = conf_addr->next)
 	if (conf_addr->wildcard_mask != 0 &&
 	    conf_addr->hwaddr_len == hw_len &&	
@@ -366,6 +373,21 @@ struct dhcp_config *find_config(struct dhcp_config *configs,
   return candidate;
 }
 
+/* Find tagged configs first. */
+struct dhcp_config *find_config(struct dhcp_config *configs,
+				struct dhcp_context *context,
+				unsigned char *clid, int clid_len,
+				unsigned char *hwaddr, int hw_len, 
+				int hw_type, char *hostname, struct dhcp_netid *tags)
+{
+  struct dhcp_config *ret = find_config_match(configs, context, clid, clid_len, hwaddr, hw_len, hw_type, hostname, tags, 0);
+
+  if (!ret)
+    ret = find_config_match(configs, context, clid, clid_len, hwaddr, hw_len, hw_type, hostname, tags, 1);
+
+  return ret;
+}
+
 void dhcp_update_configs(struct dhcp_config *configs)
 {
   /* Some people like to keep all static IP addresses in /etc/hosts.

src/dnsmasq.h

@@ -767,6 +767,7 @@ struct dhcp_config {
   unsigned char *clid;   /* clientid */
   char *hostname, *domain;
   struct dhcp_netid_list *netid;
+  struct dhcp_netid *filter;
 #ifdef HAVE_DHCP6
   struct addrlist *addr6;
 #endif
@@ -1555,7 +1556,8 @@ struct dhcp_config *find_config(struct dhcp_config *configs,
 				struct dhcp_context *context,
 				unsigned char *clid, int clid_len,
 				unsigned char *hwaddr, int hw_len, 
-				int hw_type, char *hostname);
+				int hw_type, char *hostname,
+				struct dhcp_netid *filter);
 int config_has_mac(struct dhcp_config *config, unsigned char *hwaddr, int len, int type);
 #ifdef HAVE_LINUX_NETWORK
 char *whichdevice(void);

src/lease.c

@@ -230,7 +230,7 @@ void lease_update_from_configs(void)
     if (lease->flags & (LEASE_TA | LEASE_NA))
       continue;
     else if ((config = find_config(daemon->dhcp_conf, NULL, lease->clid, lease->clid_len, 
-				   lease->hwaddr, lease->hwaddr_len, lease->hwaddr_type, NULL)) && 
+				   lease->hwaddr, lease->hwaddr_len, lease->hwaddr_type, NULL, NULL)) && 
 	     (config->flags & CONFIG_NAME) &&
 	     (!(config->flags & CONFIG_ADDR) || config->addr.s_addr == lease->addr.s_addr))
       lease_set_hostname(lease, config->hostname, 1, get_domain(lease->addr), NULL);

src/option.c

@@ -963,8 +963,7 @@ static char *set_prefix(char *arg)
    return arg;
 }
 
-static struct dhcp_netid *
+static struct dhcp_netid *dhcp_netid_create(const char *net, struct dhcp_netid *next)
-dhcp_netid_create(const char *net, struct dhcp_netid *next)
 {
   struct dhcp_netid *tt;
   tt = opt_malloc(sizeof (struct dhcp_netid));
@@ -1029,6 +1028,7 @@ static void dhcp_config_free(struct dhcp_config *config)
         }
       
       dhcp_netid_list_free(config->netid);
+      dhcp_netid_free(config->filter);
       
       if (config->flags & CONFIG_CLID)
         free(config->clid);
@@ -3217,6 +3217,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	new->flags = (option == LOPT_BANK) ? CONFIG_BANK : 0;
 	new->hwaddr = NULL;
 	new->netid = NULL;
+	new->filter = NULL;
 	new->clid = NULL;
 	new->addr6 = NULL;
 
@@ -3265,11 +3266,8 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 		    newlist->list = dhcp_netid_create(arg+4, NULL);
 		  }
 		else if (strstr(arg, "tag:") == arg)
-		  {
+		  new->filter = dhcp_netid_create(arg+4, new->filter);
 		  
-		    dhcp_config_free(new);
-		    ret_err(_("cannot match tags in --dhcp-host"));
-		  }
 #ifdef HAVE_DHCP6
 		else if (arg[0] == '[' && arg[strlen(arg)-1] == ']')
 		  {

src/rfc2131.c

@@ -504,7 +504,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
   mess->op = BOOTREPLY;
   
   config = find_config(daemon->dhcp_conf, context, clid, clid_len, 
-		       mess->chaddr, mess->hlen, mess->htype, NULL);
+		       mess->chaddr, mess->hlen, mess->htype, NULL, run_tag_if(netid));
 
   /* set "known" tag for known hosts */
   if (config)
@@ -514,7 +514,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
       netid = &known_id;
     }
   else if (find_config(daemon->dhcp_conf, NULL, clid, clid_len, 
-		       mess->chaddr, mess->hlen, mess->htype, NULL))
+		       mess->chaddr, mess->hlen, mess->htype, NULL, run_tag_if(netid)))
     {
       known_id.net = "known-othernet";
       known_id.next = netid;
@@ -781,7 +781,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		 to avoid impersonation by name. */
 	      struct dhcp_config *new = find_config(daemon->dhcp_conf, context, NULL, 0,
 						    mess->chaddr, mess->hlen, 
-						    mess->htype, hostname);
+						    mess->htype, hostname, run_tag_if(netid));
 	      if (new && !have_config(new, CONFIG_CLID) && !new->hwaddr)
 		{
 		  config = new;

src/rfc3315.c

@@ -526,7 +526,8 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
     }	 
   
   if (state->clid &&
-      (config = find_config(daemon->dhcp_conf, state->context, state->clid, state->clid_len, state->mac, state->mac_len, state->mac_type, NULL)) &&
+      (config = find_config(daemon->dhcp_conf, state->context, state->clid, state->clid_len,
+			    state->mac, state->mac_len, state->mac_type, NULL, run_tag_if(state->tags))) &&
       have_config(config, CONFIG_NAME))
     {
       state->hostname = config->hostname;
@@ -546,7 +547,7 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
 	      /* Search again now we have a hostname. 
 		 Only accept configs without CLID here, (it won't match)
 		 to avoid impersonation by name. */
-	      struct dhcp_config *new = find_config(daemon->dhcp_conf, state->context, NULL, 0, NULL, 0, 0, state->hostname);
+	      struct dhcp_config *new = find_config(daemon->dhcp_conf, state->context, NULL, 0, NULL, 0, 0, state->hostname, run_tag_if(state->tags));
 	      if (new && !have_config(new, CONFIG_CLID) && !new->hwaddr)
 		config = new;
 	    }
@@ -572,7 +573,8 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
 	ignore = 1;
     }
   else if (state->clid &&
-	   find_config(daemon->dhcp_conf, NULL, state->clid, state->clid_len, state->mac, state->mac_len, state->mac_type, NULL))
+	   find_config(daemon->dhcp_conf, NULL, state->clid, state->clid_len,
+		       state->mac, state->mac_len, state->mac_type, NULL, run_tag_if(state->tags)))
     {
       known_id.net = "known-othernet";
       known_id.next = state->tags;