lib: Add np1_flow_read and np1_flow_write calls

Reading/writing to (N + 1)-flows from the IPCP was using a raw QoS flow
to bypass some functions in the ipcp_flow_read call. But this call was
broken for keepalive packets.  Fixing the ipcp_flow_read call for
(N - 1) flows causes the IPCPs to drop 0-byte keepalive packets coming from
(N + 1) client flows.

>From now on, there is a dedicated call for (N + 1) reads/writes from
the IPCPs that's more efficient and cleaner. The (N + 1) flow internal
QoS is now also defaulted to a qos_np1 qosspec, instead of tampering
with the qosspec requested by the (N + 1) client.

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

4 files changed, 12 insertions, 5 deletions

diff --git a/src/ipcpd/unicast/dt.c b/src/ipcpd/unicast/dt.c
index 9c16e5d0..9cc53edc 100644
--- a/src/ipcpd/unicast/dt.c
+++ b/src/ipcpd/unicast/dt.c
@@ -713,7 +713,7 @@ void dt_fini(void)
 
 int dt_start(void)
 {
-        dt.psched = psched_create(packet_handler);
+        dt.psched = psched_create(packet_handler, ipcp_flow_read);
         if (dt.psched == NULL) {
                 log_err("Failed to create N-1 packet scheduler.");
                 return -1;
diff --git a/src/ipcpd/unicast/fa.c b/src/ipcpd/unicast/fa.c
index 5f3dd1a7..345d4031 100644
--- a/src/ipcpd/unicast/fa.c
+++ b/src/ipcpd/unicast/fa.c
@@ -756,7 +756,7 @@ int fa_start(void)
         int                 pol;
         int                 max;
 
-        fa.psched = psched_create(packet_handler);
+        fa.psched = psched_create(packet_handler, np1_flow_read);
         if (fa.psched == NULL) {
                 log_err("Failed to start packet scheduler.");
                 goto fail_psched;
diff --git a/src/ipcpd/unicast/psched.c b/src/ipcpd/unicast/psched.c
index 33ac5afe..bb452726 100644
--- a/src/ipcpd/unicast/psched.c
+++ b/src/ipcpd/unicast/psched.c
@@ -50,6 +50,7 @@ static int qos_prio [] = {
 struct psched {
         fset_t *         set[QOS_CUBE_MAX];
         next_packet_fn_t callback;
+        read_fn_t        read;
         pthread_t        readers[QOS_CUBE_MAX * IPCP_SCHED_THR_MUL];
 };
 
@@ -101,7 +102,7 @@ static void * packet_reader(void * o)
                                 notifier_event(NOTIFY_DT_FLOW_UP, &fd);
                                 break;
                         case FLOW_PKT:
-                                if (ipcp_flow_read(fd, &sdb))
+                                if (sched->read(fd, &sdb) < 0)
                                         continue;
 
                                 sched->callback(fd, qc, sdb);
@@ -117,7 +118,8 @@ static void * packet_reader(void * o)
         return (void *) 0;
 }
 
-struct psched * psched_create(next_packet_fn_t callback)
+struct psched * psched_create(next_packet_fn_t callback,
+                              read_fn_t        read)
 {
         struct psched *       psched;
         struct sched_info *   infos[QOS_CUBE_MAX * IPCP_SCHED_THR_MUL];
@@ -131,6 +133,7 @@ struct psched * psched_create(next_packet_fn_t callback)
                 goto fail_malloc;
 
         psched->callback = callback;
+        psched->read     = read;
 
         for (i = 0; i < QOS_CUBE_MAX; ++i) {
                 psched->set[i] = fset_create();
diff --git a/src/ipcpd/unicast/psched.h b/src/ipcpd/unicast/psched.h
index 1f22b34b..654d73d9 100644
--- a/src/ipcpd/unicast/psched.h
+++ b/src/ipcpd/unicast/psched.h
@@ -30,7 +30,11 @@ typedef void (* next_packet_fn_t)(int                  fd,
                                   qoscube_t            qc,
                                   struct shm_du_buff * sdb);
 
-struct psched * psched_create(next_packet_fn_t callback);
+typedef int (* read_fn_t)(int                   fd,
+                          struct shm_du_buff ** sdb);
+
+struct psched * psched_create(next_packet_fn_t callback,
+                              read_fn_t        read);
 
 void            psched_destroy(struct psched * psched);