1 files changed, 80 insertions, 0 deletions
diff --git a/src/dnsstub/dns_name.c b/src/dnsstub/dns_name.c
new file mode 100644
index 0000000..0723a8f
--- /dev/null
+++ b/src/dnsstub/dns_name.c
@@ -0,0 +1,80 @@
+#include "stralloc.h"
+#include "uint_t.h"
+#include "byte.h"
+#include "ip.h"
+#include "dnsresolv.h"
+
+/**
+	@file dns_name.c
+	@author djb, fefe, feh
+	@source ucspi-tcp
+	@brief DNS name query (ptr)
+*/
+
+static char *q = 0;
+
+int dns_name_packet(stralloc *out,const char *buf,unsigned int len)
+{
+  unsigned int pos;
+  char header[12];
+  uint16 numanswers;
+  uint16 datalen;
+
+  if (!stralloc_copys(out,"")) return DNS_MEM;
+
+  pos = dns_packet_copy(buf,len,0,header,12); if (!pos) return DNS_ERR;
+  uint16_unpack_big(header + 6,&numanswers);
+  pos = dns_packet_skipname(buf,len,pos); if (!pos) return DNS_ERR;
+  pos += 4;
+
+  while (numanswers--) {
+    pos = dns_packet_skipname(buf,len,pos); if (!pos) return DNS_ERR;
+    pos = dns_packet_copy(buf,len,pos,header,10); if (!pos) return DNS_ERR;
+    uint16_unpack_big(header + 8,&datalen);
+    if (byte_equal(header,2,DNS_T_PTR))
+      if (byte_equal(header + 2,2,DNS_C_IN)) {
+        if (!dns_packet_getname(buf,len,pos,&q)) return DNS_ERR;
+        if (dns_domain_todot_cat(out,q) <= 0) return DNS_ERR;
+        return 1;
+      }
+    pos += datalen;
+  }
+
+  return 0;
+}
+
+int dns_name4(stralloc *out,const char ip[4])
+{
+  int rc;
+  char name[DNS_NAME4_DOMAIN];
+
+  dns_name4_domain(name,ip);
+  if (dns_resolve(name,DNS_T_PTR) < 0) return DNS_ERR;
+  if ((rc = dns_name_packet(out,dns_resolve_tx.packet,dns_resolve_tx.packetlen)) < 0) return DNS_ERR;
+  dns_transmit_free(&dns_resolve_tx);
+  dns_domain_free(&q);
+
+  return rc;
+}
+
+int dns_name6(stralloc *out,const char ip[16])
+{
+  int rc;
+  char name[DNS_NAME6_DOMAIN];
+
+  dns_name6_domain(name,ip);
+  if (dns_resolve(name,DNS_T_PTR) < 0) return DNS_ERR;
+  if ((rc = dns_name_packet(out,dns_resolve_tx.packet,dns_resolve_tx.packetlen)) < 0) return DNS_ERR;
+  dns_transmit_free(&dns_resolve_tx);
+  dns_domain_free(&q);
+
+  return rc;
+}
+
+int dns_name(stralloc *out,const char ip[16])
+{
+  if (ip6_isv4mapped(ip))
+    return dns_name4(out,ip+12);
+  else
+    return dns_name6(out,ip);
+}