From 10a2ebc88b09defa4109486c9d31f48bf78ed72c Mon Sep 17 00:00:00 2001
From: Melinda Shore <melinda.shore@nomountain.net>
Date: Wed, 30 Oct 2013 13:16:20 -0700
Subject: [PATCH] Added address-to-hostname lookup.  Note: need a more robust
 address reverser

---
 src/hostname.c      | 33 ++++++++++++++++++++++++++-------
 src/sync.c          | 25 +++++++++++++++++++++++--
 src/util-internal.c | 30 ++++++++++++++++++++++++++++++
 src/util-internal.h |  1 +
 4 files changed, 80 insertions(+), 9 deletions(-)

diff --git a/src/hostname.c b/src/hostname.c
index e7ef7b74..dbdfe62d 100644
--- a/src/hostname.c
+++ b/src/hostname.c
@@ -29,6 +29,11 @@
  */
 
 #include <getdns/getdns.h>
+#include "context.h"
+#include "general.h"
+#include "util-internal.h"
+#include <string.h>
+
 
 /* stuff to make it compile pedantically */
 #define UNUSED_PARAM(x) ((void)(x))
@@ -47,13 +52,27 @@ getdns_hostname(
   getdns_callback_t          callback
 )
 {
-    UNUSED_PARAM(context);
-    UNUSED_PARAM(address);
-    UNUSED_PARAM(extensions);
-    UNUSED_PARAM(userarg);
-    UNUSED_PARAM(transaction_id);
-    UNUSED_PARAM(callback);
-    
+    struct getdns_bindata *address_data;
+    struct getdns_bindata *address_type;
+    uint16_t req_type;
+    char *name;
+    getdns_return_t retval;
+
+
+    if ((retval = getdns_dict_get_bindata(address, "address_data", &address_data)) != GETDNS_RETURN_GOOD)
+        return retval;
+    if ((retval = getdns_dict_get_bindata(address, "address_type", &address_type)) != GETDNS_RETURN_GOOD)
+        return retval;
+    if ((strncmp(GETDNS_STR_IPV4, (char *)address_type->data, strlen(GETDNS_STR_IPV4)) == 0) ||
+        (strncmp(GETDNS_STR_IPV6, (char *)address_type->data, strlen(GETDNS_STR_IPV6)) == 0))  
+        req_type = GETDNS_RRTYPE_PTR;
+    else
+        return GETDNS_RETURN_WRONG_TYPE_REQUESTED;
+    if ((name = reverse_address((char *)address_data->data)) == 0)
+        return GETDNS_RETURN_GENERIC_ERROR;
+    return getdns_general(context, name, req_type, extensions,
+                          userarg, transaction_id, callback);
+
     return GETDNS_RETURN_GOOD;
 } /* getdns_hostname */
 
diff --git a/src/sync.c b/src/sync.c
index bdd2b62b..a434ba26 100644
--- a/src/sync.c
+++ b/src/sync.c
@@ -157,8 +157,29 @@ getdns_hostname_sync(
   uint32_t               *response_length,
   struct getdns_dict     **response
 )
-{ UNUSED_PARAM(context); UNUSED_PARAM(address); UNUSED_PARAM(extensions);
-UNUSED_PARAM(response_length); UNUSED_PARAM(response); return GETDNS_RETURN_GOOD; }
+{
+    struct getdns_bindata *address_data;
+    struct getdns_bindata *address_type;
+    uint16_t req_type;
+    char *name;
+    getdns_return_t retval;
+
+
+    if ((retval = getdns_dict_get_bindata(address, "address_data", &address_data)) != GETDNS_RETURN_GOOD)
+        return retval;
+    if ((retval = getdns_dict_get_bindata(address, "address_type", &address_type)) != GETDNS_RETURN_GOOD)
+        return retval;
+    if ((strncmp(GETDNS_STR_IPV4, (char *)address_type->data, strlen(GETDNS_STR_IPV4)) == 0) ||
+        (strncmp(GETDNS_STR_IPV6, (char *)address_type->data, strlen(GETDNS_STR_IPV6)) == 0))
+        req_type = GETDNS_RRTYPE_PTR;
+    else
+        return GETDNS_RETURN_WRONG_TYPE_REQUESTED;
+    if ((name = reverse_address((char *)address_data)) == 0)
+        return GETDNS_RETURN_GENERIC_ERROR;
+    return getdns_general_sync(context, name, req_type, extensions,
+                        response_length, response);
+}
+
 
 getdns_return_t
 getdns_service_sync(
diff --git a/src/util-internal.c b/src/util-internal.c
index 07537c9a..402d09db 100644
--- a/src/util-internal.c
+++ b/src/util-internal.c
@@ -462,3 +462,33 @@ getdns_dict *create_getdns_response(struct getdns_dns_req* completed_request) {
     return result;
 }
 
+/*
+ * temporary, cheesy function to reverse an IPv4 address
+ * and slap "in-addr.arpa" on it.  Will replace
+ *           XXX
+ */
+
+char *
+reverse_address(char *addr_str)
+{
+    char *res_buf;
+    char *src_start = 0;
+    char *dest_start;
+
+    /* magic number 9 = 3 '.' + 5 'in-addr.arpa' + null terminator */
+    if ((res_buf = (char *)malloc(strlen(addr_str)+17)) == (char *)0)
+        return 0;
+    dest_start=res_buf;
+    while ((src_start = strrchr(addr_str, '.')) != 0)  {
+        strcpy(dest_start, src_start+1);
+        *src_start = 0;
+        dest_start = dest_start + strlen(dest_start);
+        *dest_start++ = '.';
+    }
+    strcpy(dest_start, addr_str);
+    dest_start = dest_start + strlen(dest_start);
+    strcpy(dest_start, ".in-addr.arpa");
+
+    return res_buf;
+}
+
diff --git a/src/util-internal.h b/src/util-internal.h
index 22094572..94b95bc3 100644
--- a/src/util-internal.h
+++ b/src/util-internal.h
@@ -51,3 +51,4 @@ getdns_return_t getdns_dict_util_set_string(getdns_dict* dict, char* name,
 /* get a string from a dict.  result is valid as long as dict is valid */
 getdns_return_t getdns_dict_util_get_string(getdns_dict* dict, char* name,
                                             char** result);
+char *reverse_address(char *addr_str);