Merged in sandervrijders/ouroboros/be-frct (pull request #555)

lib: Add basic FRCT mechanisms

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;
+}