1 files changed, 101 insertions, 0 deletions
diff --git a/pickdns.c b/pickdns.c
new file mode 100644
index 0000000..28c4ba5
--- /dev/null
+++ b/pickdns.c
@@ -0,0 +1,101 @@
+#include <unistd.h>
+#include "byte.h"
+#include "case.h"
+#include "dns.h"
+#include "open.h"
+#include "cdb.h"
+#include "response.h"
+
+const char *fatal = "pickdns: fatal: ";
+const char *starting = "starting pickdns\n";
+
+static char seed[128];
+
+void initialize(void)
+{
+  dns_random_init(seed);
+}
+
+static struct cdb c;
+static char key[258];
+static char data[512];
+
+static int doit(char *q,char qtype[2],char ip[4])
+{
+  int r;
+  uint32 dlen;
+  unsigned int qlen;
+  int flaga;
+  int flagmx;
+
+  qlen = dns_domain_length(q);
+  if (qlen > 255) return 0; /* impossible */
+
+  flaga = byte_equal(qtype,2,DNS_T_A);
+  flagmx = byte_equal(qtype,2,DNS_T_MX);
+  if (byte_equal(qtype,2,DNS_T_ANY)) flaga = flagmx = 1;
+  if (!flaga && !flagmx) goto REFUSE;
+
+  key[0] = '%';
+  byte_copy(key + 1,4,ip);
+
+  r = cdb_find(&c,key,5);
+  if (!r) r = cdb_find(&c,key,4);
+  if (!r) r = cdb_find(&c,key,3);
+  if (!r) r = cdb_find(&c,key,2);
+  if (r == -1) return 0;
+
+  key[0] = '+';
+  byte_zero(key + 1,2);
+  if (r && (cdb_datalen(&c) == 2))
+    if (cdb_read(&c,key + 1,2,cdb_datapos(&c)) == -1) return 0;
+
+  byte_copy(key + 3,qlen,q);
+  case_lowerb(key + 3,qlen + 3);
+
+  r = cdb_find(&c,key,qlen + 3);
+  if (!r) {
+    byte_zero(key + 1,2);
+    r = cdb_find(&c,key,qlen + 3);
+  }
+  if (!r) goto REFUSE;
+  if (r == -1) return 0;
+  dlen = cdb_datalen(&c);
+
+  if (dlen > 512) dlen = 512;
+  if (cdb_read(&c,data,dlen,cdb_datapos(&c)) == -1) return 0;
+
+  if (flaga) {
+    dns_sortip(data,dlen);
+    if (dlen > 12) dlen = 12;
+    while (dlen >= 4) {
+      dlen -= 4;
+      if (!response_rstart(q,DNS_T_A,5)) return 0;
+      if (!response_addbytes(data + dlen,4)) return 0;
+      response_rfinish(RESPONSE_ANSWER);
+    }
+  }
+
+  return 1;
+
+
+  REFUSE:
+  response[2] &= ~4;
+  response[3] &= ~15;
+  response[3] |= 5;
+  return 1;
+}
+
+int respond(char *q,char qtype[2],char ip[4])
+{
+  int fd;
+  int result;
+
+  fd = open_read("data.cdb");
+  if (fd == -1) return 0;
+  cdb_init(&c,fd);
+  result = doit(q,qtype,ip);
+  cdb_free(&c);
+  close(fd);
+  return result;
+}