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>

7 files changed, 39 insertions, 19 deletions

diff --git a/src/ipcpd/eth/eth.c b/src/ipcpd/eth/eth.c
index 53dc3b69..b7b3a41d 100644
--- a/src/ipcpd/eth/eth.c
+++ b/src/ipcpd/eth/eth.c
@@ -1016,10 +1016,15 @@ static void * eth_ipcp_packet_reader(void * o)
 #ifndef HAVE_NETMAP
                         shm_du_buff_head_release(sdb, ETH_HEADER_TOT_SIZE);
                         shm_du_buff_truncate(sdb, length);
-                        ipcp_flow_write(fd, sdb);
 #else
-                        flow_write(fd, &e_frame->payload, length);
+                        if (ipcp_sdb_reserve(&sdb, length))
+                                continue;
+
+                        buf = shm_du_buff_head(sdb);
+                        memcpy(buf, &e_frame->payload, length);
 #endif
+                        if (np1_flow_write(fd, sdb) < 0)
+                                ipcp_sdb_release(sdb);
                 }
         }
 
@@ -1062,7 +1067,7 @@ static void * eth_ipcp_packet_writer(void * o)
                         if (fqueue_type(fq) != FLOW_PKT)
                                 continue;
 
-                        if (ipcp_flow_read(fd, &sdb)) {
+                        if (np1_flow_read(fd, &sdb)) {
                                 log_dbg("Bad read from fd %d.", fd);
                                 continue;
                         }
diff --git a/src/ipcpd/ipcp.c b/src/ipcpd/ipcp.c
index d19d8e43..2426fbab 100644
--- a/src/ipcpd/ipcp.c
+++ b/src/ipcpd/ipcp.c
@@ -514,10 +514,8 @@ static void * mainloop(void * o)
                                 break;
                         }
 
-                        qs = msg_to_spec(msg->qosspec);
                         fd = np1_flow_alloc(msg->pid,
-                                            msg->flow_id,
-                                            qs);
+                                            msg->flow_id);
                         if (fd < 0) {
                                 log_err("Failed allocating fd on flow_id %d.",
                                         msg->flow_id);
@@ -525,6 +523,7 @@ static void * mainloop(void * o)
                                 break;
                         }
 
+                        qs = msg_to_spec(msg->qosspec);
                         ret_msg.result =
                                 ipcpi.ops->ipcp_flow_alloc(fd,
                                                            msg->hash.data,
@@ -549,10 +548,8 @@ static void * mainloop(void * o)
                                 break;
                         }
 
-                        qs = msg_to_spec(msg->qosspec);
                         fd = np1_flow_alloc(msg->pid,
-                                            msg->flow_id,
-                                            qs);
+                                            msg->flow_id);
                         if (fd < 0) {
                                 log_err("Failed allocating fd on flow_id %d.",
                                         msg->flow_id);
@@ -560,6 +557,7 @@ static void * mainloop(void * o)
                                 break;
                         }
 
+                        qs = msg_to_spec(msg->qosspec);
                         ret_msg.result =
                                 ipcpi.ops->ipcp_flow_join(fd,
                                                           msg->hash.data,
diff --git a/src/ipcpd/udp/main.c b/src/ipcpd/udp/main.c
index d3104163..6e32638d 100644
--- a/src/ipcpd/udp/main.c
+++ b/src/ipcpd/udp/main.c
@@ -450,9 +450,11 @@ static void * ipcp_udp_packet_reader(void * o)
         eid_p = (uint32_t *) buf;
 
         while (true) {
-                struct mgmt_frame * frame;
-                struct sockaddr_in  r_saddr;
-                socklen_t           len;
+                struct mgmt_frame *  frame;
+                struct sockaddr_in   r_saddr;
+                socklen_t            len;
+                struct shm_du_buff * sdb;
+                uint8_t *            head;
 
                 len = sizeof(r_saddr);
 
@@ -493,7 +495,15 @@ static void * ipcp_udp_packet_reader(void * o)
                         continue;
                 }
 
-                flow_write(eid, data, n - sizeof(eid));
+                n-= sizeof(eid);
+
+                if (ipcp_sdb_reserve(&sdb, n))
+                        continue;
+
+                head = shm_du_buff_head(sdb);
+                memcpy(head, data, n);
+                if (np1_flow_write(eid, sdb) < 0)
+                        ipcp_sdb_release(sdb);
         }
 
         return 0;
@@ -536,7 +546,7 @@ static void * ipcp_udp_packet_writer(void * o)
                         if (fqueue_type(fq) != FLOW_PKT)
                                 continue;
 
-                        if (ipcp_flow_read(fd, &sdb)) {
+                        if (np1_flow_read(fd, &sdb)) {
                                 log_dbg("Bad read from fd %d.", fd);
                                 continue;
                         }
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);