--- gvpe/src/vpn_dns.C	2011/10/18 10:54:17	1.53
+++ gvpe/src/vpn_dns.C	2022/10/06 03:03:09	1.57
@@ -148,7 +148,7 @@
 
 #define MAX_DEC_LEN 500
 #define MAX_ENC_LEN (MAX_DEC_LEN * 2)
-#define MAX_LIMBS ((MAX_DEC_LEN * 8 + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS)
+#define MAX_LIMBS ((MAX_DEC_LEN * 8 + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS + 1)
 
 // ugly. minimum base is 16(!)
 struct basecoder
@@ -169,6 +169,8 @@
 basecoder::basecoder (const char *cmap)
 : cmap (cmap)
 {
+  int decn = -1;
+
   for (unsigned int len = 0; len < MAX_DEC_LEN; ++len)
     {
       u8 src [MAX_DEC_LEN];
@@ -182,11 +184,12 @@
       n = mpn_set_str (m, src, len, 256);
       n = mpn_get_str (dst, this->cmap.size, m, n);
 
-      for (int i = 0; !dst [i]; ++i)
-        n--;
+      for (int i = 0; n && !dst [i]; ++i, --n)
+        ;
 
       enc_len [len] = n;
-      dec_len [n] = len;
+      while (decn < n)
+        dec_len [++decn] = len;
     }
 }
 
@@ -199,9 +202,6 @@
 unsigned int
 basecoder::decode_len (unsigned int len) const
 {
-  while (len && !dec_len [len])
-    --len;
-
   return dec_len [len];
 }
 
@@ -311,9 +311,9 @@
   seqno &= SEQNO_MASK;
 
   u8 hdr[3] = {
-    seqno,
-    (seqno >> 8) | (retry << 6),
-    clientid,
+    u8 (seqno),
+    u8 ((seqno >> 8) | (retry << 6)),
+    u8 (clientid),
   };
 
   cdc36.encode (data, hdr, 3);
@@ -366,8 +366,7 @@
 void
 byte_stream::remove (int count)
 {
-  if (count > fill)
-    assert (count <= fill);
+  assert (count <= fill);
 
   memmove (data, data + count, fill -= count);
 }
@@ -397,19 +396,23 @@
   return true;
 }
 
-vpn_packet *byte_stream::get ()
+vpn_packet *
+byte_stream::get ()
 {
   unsigned int len;
   
   for (;;)
     {
+      if (fill < 2)
+        return 0;
+
       len = (data [0] << 8) | data [1];
 
-      if (len <= MAXSIZE || fill < 2)
+      if (len <= MAXSIZE)
         break;
 
       // TODO: handle this better than skipping, e.g. by reset
-      slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
+      slog (L_DEBUG, _("DNS: corrupted packet (%02x %02x > %d) stream skipping a byte..."), data [0], data [1], MAXSIZE);
       remove (1);
     }