lib: Refactor FRCT implementation

The frct_pci and rq headers are moved from include/ouroboros to
src/lib since they are only needed in the library. FRCT is moved to
its own source file.

FRCT takes the application PDUs, encapsulates and processes them and
hands them back. This makes it easier to disable FRCT should the
application want to write to a "raw" flow. An FRCT instance is now
allocated upon alloc and released upon dealloc.

The FRCT data structure is split into a sender and receiver connection
record. Setting a new configuration will now be done upon sending the
next data PDU, which will flag the DRF for a new run and use that
configuration. This avoids some issues should packets arrive
out-of-order, and simplifies setting a configuration.

Signed-off-by: Dimitri Staessens <[email protected]>
Signed-off-by: Sander Vrijders <[email protected]>

1 files changed, 26 insertions, 37 deletions

diff --git a/src/lib/frct_pci.c b/src/lib/frct_pci.c
index e44554f2..509cc8e2 100644
--- a/src/lib/frct_pci.c
+++ b/src/lib/frct_pci.c
@@ -20,29 +20,23 @@
  * Foundation, Inc., http://www.fsf.org/about/contact/.
  */
 
-#include <ouroboros/frct_pci.h>
 #include <ouroboros/hash.h>
 #include <ouroboros/errno.h>
 
+#include "frct_pci.h"
+
 #include <assert.h>
 #include <string.h>
 
-#define TYPE_SIZE       1
-#define SEQNO_SIZE      8
-#define FLAGS_SIZE      1
-#define CONF_FLAGS_SIZE sizeof(((struct frct_pci *) NULL)->conf_flags)
-#define BASE_SIZE       TYPE_SIZE + FLAGS_SIZE + SEQNO_SIZE
-#define CONFIG_SIZE     CONF_FLAGS_SIZE
-
-static size_t get_head_len(struct frct_pci * pci)
-{
-        size_t len = BASE_SIZE;
+#define TYPE_SIZE        1
+#define FLAGS_SIZE       1
+#define SEQNO_SIZE       8
+#define CONF_FLAGS_SIZE  2
 
-        if (pci->type & PDU_TYPE_CONFIG)
-                len += CONFIG_SIZE;
+#define BASE_SIZE        TYPE_SIZE + FLAGS_SIZE + SEQNO_SIZE
 
-        return len;
-}
+#define head_len(pci)    (pci->type & PDU_TYPE_CONFIG ?                 \
+                          BASE_SIZE + CONF_FLAGS_SIZE : BASE_SIZE)
 
 int frct_pci_ser(struct shm_du_buff * sdb,
                  struct frct_pci *    pci,
@@ -50,15 +44,12 @@ int frct_pci_ser(struct shm_du_buff * sdb,
 {
         uint8_t * head;
         uint8_t * tail;
-        size_t    len;
         size_t    offset = 0;
 
         assert(sdb);
         assert(pci);
 
-        len = get_head_len(pci);
-
-        head = shm_du_buff_head_alloc(sdb, len);
+        head = shm_du_buff_head_alloc(sdb, head_len(pci));
         if (head == NULL)
                 return -EPERM;
 
@@ -70,14 +61,14 @@ int frct_pci_ser(struct shm_du_buff * sdb,
         offset += SEQNO_SIZE;
 
         if (pci->type & PDU_TYPE_CONFIG) {
-                memcpy(head + offset, &pci->conf_flags, CONF_FLAGS_SIZE);
+                memcpy(head + offset, &pci->cflags, CONF_FLAGS_SIZE);
                 /* offset += CONF_FLAGS_SIZE; */
         }
 
         if (error_check) {
                 tail = shm_du_buff_tail_alloc(sdb, hash_len(HASH_CRC32));
                 if (tail == NULL) {
-                        shm_du_buff_head_release(sdb, len);
+                        shm_du_buff_head_release(sdb, head_len(pci));
                         return -EPERM;
                 }
 
@@ -103,23 +94,8 @@ int frct_pci_des(struct shm_du_buff * sdb,
 
         head = shm_du_buff_head(sdb);
 
-         /* Depending on the type a different deserialization. */
-        memcpy(&pci->type, head, TYPE_SIZE);
-        offset += TYPE_SIZE;
-        memcpy(&pci->flags, head + offset, FLAGS_SIZE);
-        offset += FLAGS_SIZE;
-        memcpy(&pci->seqno, head + offset, SEQNO_SIZE);
-        offset += SEQNO_SIZE;
-
-        if (pci->type & PDU_TYPE_CONFIG) {
-                memcpy(&pci->conf_flags, head + offset, CONF_FLAGS_SIZE);
-                /* offset += CONF_FLAGS_SIZE; */
-        }
-
         if (error_check) {
                 tail = shm_du_buff_tail(sdb);
-                if (tail == NULL)
-                        return -EPERM;
 
                 mem_hash(HASH_CRC32, &crc, head,
                          tail - head - hash_len(HASH_CRC32));
@@ -134,7 +110,20 @@ int frct_pci_des(struct shm_du_buff * sdb,
                 shm_du_buff_tail_release(sdb, hash_len(HASH_CRC32));
         }
 
-        shm_du_buff_head_release(sdb, get_head_len(pci));
+        /* Depending on the type a different deserialization. */
+        memcpy(&pci->type, head, TYPE_SIZE);
+        offset += TYPE_SIZE;
+        memcpy(&pci->flags, head + offset, FLAGS_SIZE);
+        offset += FLAGS_SIZE;
+        memcpy(&pci->seqno, head + offset, SEQNO_SIZE);
+        offset += SEQNO_SIZE;
+
+        if (pci->type & PDU_TYPE_CONFIG) {
+                memcpy(&pci->cflags, head + offset, CONF_FLAGS_SIZE);
+                /* offset += CONF_FLAGS_SIZE; */
+        }
+
+        shm_du_buff_head_release(sdb, head_len(pci));
 
         return 0;
 }