EDNS(0) Client Subnet

- Add indexer `edns_ecs_subnet`

src/dns_message.c

@@ -120,6 +120,7 @@ static indexer indexers[] = {
     { "edns_ecs_source_prefix", indexer_want_edns_options, edns_ecs_source_prefix_indexer, edns_ecs_source_prefix_iterator, edns_ecs_source_prefix_reset },
     { "edns_ecs_scope_prefix", indexer_want_edns_options, edns_ecs_scope_prefix_indexer, edns_ecs_scope_prefix_iterator, edns_ecs_scope_prefix_reset },
     { "edns_ecs_address", indexer_want_edns_options, edns_ecs_address_indexer, edns_ecs_address_iterator, edns_ecs_address_reset },
+    { "edns_ecs_subnet", indexer_want_edns_options, edns_ecs_subnet_indexer, edns_ecs_subnet_iterator, edns_ecs_subnet_reset },
     { "edns_ede", indexer_want_edns_options, edns_ede_indexer, edns_ede_iterator },
     { "edns_ede_code", indexer_want_edns_options, edns_ede_code_indexer, edns_ede_code_iterator, edns_ede_code_reset },
     { "edns_ede_textlen", indexer_want_edns_options, edns_ede_textlen_indexer, edns_ede_textlen_iterator, edns_ede_textlen_reset },

src/dsc.conf.5.in

@@ -538,6 +538,9 @@ The EDNS(0) Client Subnet scope prefix-length.
 \fBedns_ecs_address\fR
 The EDNS(0) Client Subnet address bytes as a hexadecimal string.
 .TP
+\fBedns_ecs_subnet\fR
+The EDNS(0) Client Subnet address as an IPv4/IPv6 textual address.
+.TP
 \fBedns_ede\fR
 Indicates whether or not a EDNS(0) Extended DNS Errors (RFC8914) was present with "yes" or "no".
 .TP

src/edns_ecs_index.c

@@ -39,8 +39,10 @@
 #include "edns_ecs_index.h"
 #include "xmalloc.h"
 #include "hashtbl.h"
+#include "inX_addr.h"
 
 #include <string.h>
+#include <sys/socket.h> // For AF_ on BSDs
 
 // edns_ecs
 
@@ -289,3 +291,92 @@ void edns_ecs_address_reset()
     addressHash      = NULL;
     address_next_idx = 0;
 }
+
+// edns_ecs_subnet
+
+static hashtbl* subnetHash      = NULL;
+static int      subnet_next_idx = 0;
+
+typedef struct
+{
+    inX_addr addr;
+    int      index;
+} subnetobj;
+
+static unsigned int
+subnet_hashfunc(const void* key)
+{
+    return inXaddr_hash((const inX_addr*)key);
+}
+
+static int
+subnet_cmpfunc(const void* a, const void* b)
+{
+    return inXaddr_cmp((const inX_addr*)a, (const inX_addr*)b);
+}
+
+int edns_ecs_subnet_indexer(const dns_message* m)
+{
+    subnetobj* obj;
+    inX_addr   addr = { 0 };
+
+    if (m->malformed || !m->edns.ecs.address)
+        return -1;
+    switch (m->edns.ecs.family) { // IANA Address Family Numbers
+    case 1:
+        if (m->edns.ecs.len > sizeof(addr.in4))
+            return -1;
+        addr.family = AF_INET;
+        memcpy(&addr.in4, m->edns.ecs.address, m->edns.ecs.len);
+        break;
+    case 2:
+        if (m->edns.ecs.len > sizeof(addr.in6))
+            return -1;
+        addr.family = AF_INET6;
+        memcpy(&addr.in6, m->edns.ecs.address, m->edns.ecs.len);
+        break;
+    default:
+        return -1;
+    }
+    if (NULL == subnetHash) {
+        subnetHash = hash_create(MAX_ARRAY_SZ, subnet_hashfunc, subnet_cmpfunc, 1, NULL, afree);
+        if (NULL == subnetHash)
+            return -1;
+    }
+    if ((obj = hash_find(&addr, subnetHash)))
+        return obj->index;
+    obj = acalloc(1, sizeof(*obj));
+    if (NULL == obj)
+        return -1;
+    obj->addr  = addr;
+    obj->index = subnet_next_idx;
+    if (0 != hash_add(&obj->addr, obj, subnetHash)) {
+        afree(obj);
+        return -1;
+    }
+    subnet_next_idx++;
+    return obj->index;
+}
+
+int edns_ecs_subnet_iterator(const char** label)
+{
+    subnetobj*  obj;
+    static char label_buf[128];
+    if (0 == subnet_next_idx)
+        return -1;
+    if (NULL == label) {
+        hash_iter_init(subnetHash);
+        return subnet_next_idx;
+    }
+    if ((obj = hash_iterate(subnetHash)) == NULL)
+        return -1;
+    inXaddr_ntop(&obj->addr, label_buf, 128);
+    *label = label_buf;
+    return obj->index;
+}
+
+void edns_ecs_subnet_reset()
+{
+    subnetHash      = NULL;
+    subnet_next_idx = 0;
+}

src/edns_ecs_index.h

@@ -58,4 +58,8 @@ int  edns_ecs_address_indexer(const dns_message*);
 int  edns_ecs_address_iterator(const char** label);
 void edns_ecs_address_reset(void);
 
+int  edns_ecs_subnet_indexer(const dns_message*);
+int  edns_ecs_subnet_iterator(const char** label);
+void edns_ecs_subnet_reset(void);
+
 #endif /* __dsc_edns_ecs_index_h */

src/test/test_291.conf

@@ -16,6 +16,7 @@ dataset edns_ecs_family dns All:null edns_ecs_family:edns_ecs_family edns0-only;
 dataset edns_ecs_source_prefix dns All:null edns_ecs_source_prefix:edns_ecs_source_prefix edns0-only;
 dataset edns_ecs_scope_prefix dns All:null edns_ecs_scope_prefix:edns_ecs_scope_prefix edns0-only;
 dataset edns_ecs_address dns All:null edns_ecs_address:edns_ecs_address edns0-only;
+dataset edns_ecs_subnet dns All:null edns_ecs_subnet:edns_ecs_subnet edns0-only;
 dataset edns_ede dns All:null edns_ede:edns_ede;
 dataset edns_ede_code dns All:null edns_ede_code:edns_ede_code edns0-only;
 dataset edns_ede_textlen dns All:null edns_ede_textlen:edns_ede_textlen edns0-only;

src/test/test_291.xml_gold

@@ -47,6 +47,15 @@
     </All>
   </data>
 </array>
+<array name="edns_ecs_subnet" dimensions="2" start_time="1688541698" stop_time="1688541706">
+  <dimension number="1" type="All"/>
+  <dimension number="2" type="edns_ecs_subnet"/>
+  <data>
+    <All val="ALL">
+      <edns_ecs_subnet val="172.17.0.0" count="2"/>
+    </All>
+  </data>
+</array>
 <array name="edns_ecs_address" dimensions="2" start_time="1688541698" stop_time="1688541706">
   <dimension number="1" type="All"/>
   <dimension number="2" type="edns_ecs_address"/>