From 0e5b2871ca6456b01d4bf037a6e68badf1ff1a41 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henryk=20Pl=C3=B6tz?= <henryk@ploetzli.ch>
Date: Fri, 3 Oct 2014 19:58:52 +0200
Subject: Initial commit of djbdns-1.05.tar.gz Source was
 http://cr.yp.to/djbdns/djbdns-1.05.tar.gz, SHA1
 2efdb3a039d0c548f40936aa9cb30829e0ce8c3d

---
 response.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 response.c

(limited to 'response.c')

diff --git a/response.c b/response.c
new file mode 100644
index 0000000..ba90c89
--- /dev/null
+++ b/response.c
@@ -0,0 +1,121 @@
+#include "dns.h"
+#include "byte.h"
+#include "uint16.h"
+#include "response.h"
+
+char response[65535];
+unsigned int response_len = 0; /* <= 65535 */
+static unsigned int tctarget;
+
+#define NAMES 100
+static char name[NAMES][128];
+static unsigned int name_ptr[NAMES]; /* each < 16384 */
+static unsigned int name_num;
+
+int response_addbytes(const char *buf,unsigned int len)
+{
+  if (len > 65535 - response_len) return 0;
+  byte_copy(response + response_len,len,buf);
+  response_len += len;
+  return 1;
+}
+
+int response_addname(const char *d)
+{
+  unsigned int dlen;
+  unsigned int i;
+  char buf[2];
+
+  dlen = dns_domain_length(d);
+
+  while (*d) {
+    for (i = 0;i < name_num;++i)
+      if (dns_domain_equal(d,name[i])) {
+        uint16_pack_big(buf,49152 + name_ptr[i]);
+        return response_addbytes(buf,2);
+      }
+    if (dlen <= 128)
+      if (name_num < NAMES) {
+	byte_copy(name[name_num],dlen,d);
+	name_ptr[name_num] = response_len;
+	++name_num;
+      }
+    i = (unsigned char) *d;
+    ++i;
+    if (!response_addbytes(d,i)) return 0;
+    d += i;
+    dlen -= i;
+  }
+  return response_addbytes(d,1);
+}
+
+int response_query(const char *q,const char qtype[2],const char qclass[2])
+{
+  response_len = 0;
+  name_num = 0;
+  if (!response_addbytes("\0\0\201\200\0\1\0\0\0\0\0\0",12)) return 0;
+  if (!response_addname(q)) return 0;
+  if (!response_addbytes(qtype,2)) return 0;
+  if (!response_addbytes(qclass,2)) return 0;
+  tctarget = response_len;
+  return 1;
+}
+
+static unsigned int dpos;
+
+static int flaghidettl = 0;
+
+void response_hidettl(void)
+{
+  flaghidettl = 1;
+}
+
+int response_rstart(const char *d,const char type[2],uint32 ttl)
+{
+  char ttlstr[4];
+  if (!response_addname(d)) return 0;
+  if (!response_addbytes(type,2)) return 0;
+  if (!response_addbytes(DNS_C_IN,2)) return 0;
+  if (flaghidettl) ttl = 0;
+  uint32_pack_big(ttlstr,ttl);
+  if (!response_addbytes(ttlstr,4)) return 0;
+  if (!response_addbytes("\0\0",2)) return 0;
+  dpos = response_len;
+  return 1;
+}
+
+void response_rfinish(int x)
+{
+  uint16_pack_big(response + dpos - 2,response_len - dpos);
+  if (!++response[x + 1]) ++response[x];
+}
+
+int response_cname(const char *c,const char *d,uint32 ttl)
+{
+  if (!response_rstart(c,DNS_T_CNAME,ttl)) return 0;
+  if (!response_addname(d)) return 0;
+  response_rfinish(RESPONSE_ANSWER);
+  return 1;
+}
+
+void response_nxdomain(void)
+{
+  response[3] |= 3;
+  response[2] |= 4;
+}
+
+void response_servfail(void)
+{
+  response[3] |= 2;
+}
+
+void response_id(const char id[2])
+{
+  byte_copy(response,2,id);
+}
+
+void response_tc(void)
+{
+  response[2] |= 2;
+  response_len = tctarget;
+}
-- 
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