lib: Add basic FRCT mechanisms

This adds the basic FRCT mechanisms to the library. Upon flow alloc or
accept an FRCT instance is now created and used when reading or
writing to the flow. The timerwheel has been refactored to allow
recharging timers and removing them and is now part of the
library. The first SDU sent over the connection has the DRF set and
this initializes the connection. Sender and receiver inactivity timers
are added.

1 files changed, 105 insertions, 0 deletions

diff --git a/src/lib/frct_pci.c b/src/lib/frct_pci.c
new file mode 100644
index 00000000..92cf8cd9
--- /dev/null
+++ b/src/lib/frct_pci.c
@@ -0,0 +1,105 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2017
+ *
+ * Protocol Control Information of FRCT
+ *
+ *    Dimitri Staessens <[email protected]>
+ *    Sander Vrijders   <[email protected]>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#include <ouroboros/config.h>
+#include <ouroboros/frct_pci.h>
+#include <ouroboros/hash.h>
+#include <ouroboros/errno.h>
+
+#include <assert.h>
+#include <string.h>
+
+#define TYPE_SIZE  1
+#define SEQNO_SIZE 8
+#define FLAGS_SIZE 1
+
+/* FIXME: Head size will differ on type */
+#define HEAD_SIZE TYPE_SIZE + FLAGS_SIZE + SEQNO_SIZE
+
+int frct_pci_ser(struct shm_du_buff * sdb,
+                 struct frct_pci *    pci,
+                 bool                 error_check)
+{
+        uint8_t * head;
+        uint8_t * tail;
+
+        assert(sdb);
+        assert(pci);
+
+        head = shm_du_buff_head_alloc(sdb, HEAD_SIZE);
+        if (head == NULL)
+                return -EPERM;
+
+        memcpy(head, &pci->type, TYPE_SIZE);
+        memcpy(head + TYPE_SIZE, &pci->flags, FLAGS_SIZE);
+        memcpy(head + TYPE_SIZE + FLAGS_SIZE, &pci->seqno, SEQNO_SIZE);
+
+        if (error_check) {
+                tail = shm_du_buff_tail_alloc(sdb, hash_len(HASH_CRC32));
+                if (tail == NULL) {
+                        shm_du_buff_head_release(sdb, HEAD_SIZE);
+                        return -EPERM;
+                }
+
+                *((uint32_t *) tail) = 0;
+                mem_hash(HASH_CRC32, (uint32_t *) tail, head, tail - head);
+        }
+
+        return 0;
+}
+
+int frct_pci_des(struct shm_du_buff * sdb,
+                 struct frct_pci *    pci,
+                 bool                 error_check)
+{
+        uint8_t * head;
+        uint8_t * tail;
+        uint32_t  crc;
+
+        assert(sdb);
+        assert(pci);
+
+        head = shm_du_buff_head(sdb);
+
+         /* FIXME: Depending on the type a different deserialization */
+        memcpy(&pci->type, head, TYPE_SIZE);
+        memcpy(&pci->flags, head + TYPE_SIZE, FLAGS_SIZE);
+        memcpy(&pci->seqno, head + TYPE_SIZE + FLAGS_SIZE, SEQNO_SIZE);
+
+        if (error_check) {
+                tail = shm_du_buff_tail(sdb);
+                if (tail == NULL)
+                        return -EPERM;
+
+                mem_hash(HASH_CRC32, &crc, head, tail - head);
+
+                /* Corrupted SDU */
+                if (crc != 0)
+                        return -1;
+
+                shm_du_buff_tail_release(sdb, hash_len(HASH_CRC32));
+        }
+
+        shm_du_buff_head_release(sdb, HEAD_SIZE);
+
+        return 0;
+}