X-Git-Url: https://git.distorted.org.uk/~mdw/tripe/blobdiff_plain/df9dfccffd73a98ebebdecb35b23a854a5209b78..7cd79da096ced70c89af673bc0c87990eaa68528:/servutil.c

diff --git a/servutil.c b/servutil.c
index dac92b7b..f4ab92e3 100644
--- a/servutil.c
+++ b/servutil.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: servutil.c,v 1.3 2001/06/19 22:08:11 mdw Exp $
+ * $Id$
  *
  * Various handy server-only utilities
  *
@@ -26,21 +26,6 @@
  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: servutil.c,v $
- * Revision 1.3  2001/06/19 22:08:11  mdw
- * Use magic number for packet size.
- *
- * Revision 1.2  2001/02/16 21:41:06  mdw
- * Use new spare buffer for building MP textual representations.  Add a
- * function for making human-readable time strings.
- *
- * Revision 1.1  2001/02/03 20:26:37  mdw
- * Initial checkin.
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 #include "tripe.h"
@@ -68,6 +53,24 @@ const char *mpstr(mp *m)
   return ((const char *)buf_t);
 }
 
+/* --- @gestr@ --- *
+ *
+ * Arguments:	@group *g@ = a group
+ *		@ge *x@ = a group element
+ *
+ * Returns:	A pointer to the element's textual representation.
+ *
+ * Use:		Converts a group element to a string.  Corrupts
+ *		@buf_t@.
+ */
+
+const char *gestr(group *g, ge *x)
+{
+  if (group_writestring(g, x, (char *)buf_t, sizeof(buf_t)))
+    return ("<failed>");
+  return ((const char *)buf_t);
+}
+
 /* --- @timestr@ --- *
  *
  * Arguments:	@time_t t@ = a time to convert
@@ -88,4 +91,74 @@ const char *timestr(time_t t)
   return ((const char *)buf_t);
 }
 
+/* --- @b64_encode@ --- *
+ *
+ * Arguments:	@const void *p@ = pointer to some gorp
+ *		@size_t sz@ = size of the gorp
+ *
+ * Returns:	Pointer to base64-encoded version in @buf_t@.
+ */
+
+const char *b64_encode(const void *p, size_t sz)
+{
+  base64_ctx b64;
+  dstr d = DSTR_INIT;
+
+  base64_init(&b64);
+  b64.indent = "";
+  b64.maxline = 0;
+  base64_encode(&b64, p, sz, &d);
+  base64_encode(&b64, 0, 0, &d);
+  while (d.len && d.buf[d.len - 1] == '=') d.len--;
+  assert(d.len < sizeof(buf_t));
+  memcpy(buf_t, d.buf, d.len);
+  buf_t[d.len] = 0;
+  dstr_destroy(&d);
+  return ((const char *)buf_t);
+}
+
+/* --- @seq_reset@ --- *
+ *
+ * Arguments:	@seqwin *s@ = sequence-checking window
+ *
+ * Returns:	---
+ *
+ * Use:		Resets a sequence number window.
+ */
+
+void seq_reset(seqwin *s) { s->seq = 0; s->win = 0; }
+
+/* --- @seq_check@ --- *
+ *
+ * Arguments:	@seqwin *s@ = sequence-checking window
+ *		@uint32 q@ = sequence number to check
+ *
+ * Returns:	A @SEQ_@ code.
+ *
+ * Use:		Checks a sequence number against the window, updating things
+ *		as necessary.
+ */
+
+int seq_check(seqwin *s, uint32 q)
+{
+  uint32 qbit;
+  uint32 n;
+
+  if (q < s->seq)
+    return (SEQ_OLD);
+  if (q >= s->seq + SEQ_WINSZ) {
+    n = q - (s->seq + SEQ_WINSZ - 1);
+    if (n < SEQ_WINSZ)
+      s->win >>= n;
+    else
+      s->win = 0;
+    s->seq += n;
+  }
+  qbit = 1 << (q - s->seq);
+  if (s->win & qbit)
+    return (SEQ_REPLAY);
+  s->win |= qbit;
+  return (0);
+}
+
 /*----- That's all, folks -------------------------------------------------*/