commit b6b5104bab33df9ce505234da1e08cb1b58010db
author Maciej Żenczykowski <maze@google.com> Mon Nov 18 16:41:44 2019 -0800
committer Maciej Żenczykowski <maze@google.com> Sat Nov 30 12:34:20 2019 +0000
tree acc6670b3483564d1fbc1d1ce7cf5cdad7b0cad2
parent 3cedd1d5dd99119068aeed218769bf73369b9f06

remove configuration option 'plat_from_dns64_hostname'

RFC 7050 has been a standard for so long, and is likely used
by so many other implementations, that it doesn't seem to make
sense to use anything else then 'ipv4only.arpa' (also that's
what netd uses, and this code here is really dead, since
in Q we moved the detection out of clatd and into netd).

Test: builds,
  'git grep free_config' comes up empty
  'git grep plat_from_dns64_hostname' comes up empty
Bug: 144730808
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ibf0c8d5e2cec6359fba1f7dd8867bd2742f362b4

clatd.conf

diff --git a/clatd.conf b/clatd.conf
index ff80975..aef9c75 100644
--- a/clatd.conf
+++ b/clatd.conf
@@ -14,8 +14,6 @@
 
 # get the plat_subnet from dns lookups (requires DNS64)
 plat_from_dns64 yes
-# hostname to use to lookup plat subnet. must contain only A records
-plat_from_dns64_hostname ipv4only.arpa
 
 # plat subnet to send ipv4 traffic to. This is a /96 subnet.
 # This setting only makes sense with: plat_from_dns64 no

config.c

diff --git a/config.c b/config.c
index a859092..3ea510d 100644
--- a/config.c
+++ b/config.c
@@ -150,16 +150,6 @@
   return ret_val_ptr;
 }
 
-/* function: free_config
- * frees the memory used by the global config variable
- */
-void free_config() {
-  if (Global_Clatd_Config.plat_from_dns64_hostname) {
-    free(Global_Clatd_Config.plat_from_dns64_hostname);
-    Global_Clatd_Config.plat_from_dns64_hostname = NULL;
-  }
-}
-
 /* function: ipv6_prefix_equal
  * compares the prefixes two ipv6 addresses. assumes the prefix lengths are both /64.
  *   a1 - first address
@@ -180,7 +170,7 @@
   backoff_sleep = 1;
 
   while (1) {
-    status = plat_prefix(Global_Clatd_Config.plat_from_dns64_hostname, net_id, &tmp_ptr);
+    status = plat_prefix(DNS64_DETECTION_HOSTNAME, net_id, &tmp_ptr);
     if (status > 0) {
       memcpy(&Global_Clatd_Config.plat_subnet, &tmp_ptr, sizeof(struct in6_addr));
       return;
@@ -357,9 +347,6 @@
     } else {
       free(tmp_ptr);
 
-      if (!(Global_Clatd_Config.plat_from_dns64_hostname =
-              config_item_str(root, "plat_from_dns64_hostname", DEFAULT_DNS64_DETECTION_HOSTNAME)))
-        goto failed;
       dns64_detection(net_id);
     }
   }
@@ -381,7 +368,6 @@
 
 failed:
   free(root);
-  free_config();
   return 0;
 }
 

config.h

diff --git a/config.h b/config.h
index e521b74..88c632a 100644
--- a/config.h
+++ b/config.h
@@ -23,7 +23,7 @@
 
 #define DEFAULT_IPV4_LOCAL_SUBNET "192.0.0.4"
 #define DEFAULT_IPV4_LOCAL_PREFIXLEN "29"
-#define DEFAULT_DNS64_DETECTION_HOSTNAME "ipv4only.arpa"
+#define DNS64_DETECTION_HOSTNAME "ipv4only.arpa"
 
 struct clat_config {
   int16_t mtu, ipv4mtu;
@@ -33,7 +33,6 @@
   int16_t ipv4_local_prefixlen;
   struct in6_addr plat_subnet;
   char *default_pdp_interface;
-  char *plat_from_dns64_hostname;
   int use_dynamic_iid;
 };