Move pqueue into ssl

This is an internal facility, never documented, not for
public consumption.  Move it into ssl (where it's only used
for DTLS).

I also made the typedef's for pqueue and pitem follow our style: they
name structures, not pointers.

Reviewed-by: Richard Levitte <levitte@openssl.org>
diff --git a/ssl/pqueue.c b/ssl/pqueue.c
new file mode 100644
index 0000000..21ee83e
--- /dev/null
+++ b/ssl/pqueue.c
@@ -0,0 +1,218 @@
+/* crypto/pqueue/pqueue.c */
+/*
+ * DTLS implementation written by Nagendra Modadugu
+ * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
+ */
+/* ====================================================================
+ * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include "ssl_locl.h"
+#include <openssl/bn.h>
+
+struct pqueue_st {
+    pitem *items;
+    int count;
+};
+
+pitem *pitem_new(unsigned char *prio64be, void *data)
+{
+    pitem *item = OPENSSL_malloc(sizeof(*item));
+    if (item == NULL)
+        return NULL;
+
+    memcpy(item->priority, prio64be, sizeof(item->priority));
+
+    item->data = data;
+    item->next = NULL;
+
+    return item;
+}
+
+void pitem_free(pitem *item)
+{
+    OPENSSL_free(item);
+}
+
+pqueue *pqueue_new()
+{
+    pqueue *pq = OPENSSL_zalloc(sizeof(*pq));
+
+    return pq;
+}
+
+void pqueue_free(pqueue *pq)
+{
+    OPENSSL_free(pq);
+}
+
+pitem *pqueue_insert(pqueue *pq, pitem *item)
+{
+    pitem *curr, *next;
+
+    if (pq->items == NULL) {
+        pq->items = item;
+        return item;
+    }
+
+    for (curr = NULL, next = pq->items;
+         next != NULL; curr = next, next = next->next) {
+        /*
+         * we can compare 64-bit value in big-endian encoding with memcmp:-)
+         */
+        int cmp = memcmp(next->priority, item->priority, 8);
+        if (cmp > 0) {          /* next > item */
+            item->next = next;
+
+            if (curr == NULL)
+                pq->items = item;
+            else
+                curr->next = item;
+
+            return item;
+        }
+
+        else if (cmp == 0)      /* duplicates not allowed */
+            return NULL;
+    }
+
+    item->next = NULL;
+    curr->next = item;
+
+    return item;
+}
+
+pitem *pqueue_peek(pqueue *pq)
+{
+    return pq->items;
+}
+
+pitem *pqueue_pop(pqueue *pq)
+{
+    pitem *item = pq->items;
+
+    if (pq->items != NULL)
+        pq->items = pq->items->next;
+
+    return item;
+}
+
+pitem *pqueue_find(pqueue *pq, unsigned char *prio64be)
+{
+    pitem *next;
+    pitem *found = NULL;
+
+    if (pq->items == NULL)
+        return NULL;
+
+    for (next = pq->items; next->next != NULL; next = next->next) {
+        if (memcmp(next->priority, prio64be, 8) == 0) {
+            found = next;
+            break;
+        }
+    }
+
+    /* check the one last node */
+    if (memcmp(next->priority, prio64be, 8) == 0)
+        found = next;
+
+    if (!found)
+        return NULL;
+
+    return found;
+}
+
+void pqueue_print(pqueue *pq)
+{
+    pitem *item = pq->items;
+
+    while (item != NULL) {
+        printf("item\t%02x%02x%02x%02x%02x%02x%02x%02x\n",
+               item->priority[0], item->priority[1],
+               item->priority[2], item->priority[3],
+               item->priority[4], item->priority[5],
+               item->priority[6], item->priority[7]);
+        item = item->next;
+    }
+}
+
+pitem *pqueue_iterator(pqueue *pq)
+{
+    return pqueue_peek(pq);
+}
+
+pitem *pqueue_next(pitem **item)
+{
+    pitem *ret;
+
+    if (item == NULL || *item == NULL)
+        return NULL;
+
+    /* *item != NULL */
+    ret = *item;
+    *item = (*item)->next;
+
+    return ret;
+}
+
+int pqueue_size(pqueue *pq)
+{
+    pitem *item = pq->items;
+    int count = 0;
+
+    while (item != NULL) {
+        count++;
+        item = item->next;
+    }
+    return count;
+}