ipdpd: Pass MPL to application at flow_allocation

The maximum packet lifetime (MPL) is a property of the flow that needs
to be passed to the reliable transmission protocol (FRCP) for its
correct operation. Previously, the value of MPL was set fixed as one
of the (fixed) Delta-t parameters. This patch makes the MPL a property
of the layer, and it can now be set per layer-type at build time.
This is a step towards a proper MPL estimator in the flow allocator.

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

3 files changed, 23 insertions, 8 deletions

diff --git a/src/lib/dev.c b/src/lib/dev.c
index 2e61df52..5f6a3694 100644
--- a/src/lib/dev.c
+++ b/src/lib/dev.c
@@ -574,6 +574,7 @@ int flow_accept(qosspec_t *             qs,
         uint8_t     buf[MSGBUFSZ];
         int         err = -EIRMD;
         ssize_t     key_len;
+        time_t      mpl;
 
         memset(s, 0, SYMMKEYSZ);
 
@@ -617,7 +618,7 @@ int flow_accept(qosspec_t *             qs,
         }
 
         if (!recv_msg->has_pid || !recv_msg->has_flow_id ||
-            recv_msg->qosspec == NULL)
+            !recv_msg->has_mpl || recv_msg->qosspec == NULL)
                 goto fail_result;
 
         if (recv_msg->pk.len != 0 &&
@@ -632,6 +633,8 @@ int flow_accept(qosspec_t *             qs,
         fd = flow_init(recv_msg->flow_id, recv_msg->pid,
                        msg_to_spec(recv_msg->qosspec), s);
 
+        mpl = recv_msg->mpl;
+
         irm_msg__free_unpacked(recv_msg, NULL);
 
         if (fd < 0)
@@ -642,7 +645,7 @@ int flow_accept(qosspec_t *             qs,
         assert(ai.flows[fd].frcti == NULL);
 
         if (ai.flows[fd].qs.in_order != 0) {
-                ai.flows[fd].frcti = frcti_create(fd, DELT_A, DELT_R, DELT_MPL);
+                ai.flows[fd].frcti = frcti_create(fd, DELT_A, DELT_R, mpl);
                 if (ai.flows[fd].frcti == NULL) {
                         pthread_rwlock_unlock(&ai.lock);
                         flow_dealloc(fd);
@@ -678,6 +681,7 @@ static int __flow_alloc(const char *            dst,
         uint8_t       s[SYMMKEYSZ];   /* secret key for flow */
         uint8_t       buf[MSGBUFSZ];
         int           err = -EIRMD;
+        time_t        mpl;
 
         memset(s, 0, SYMMKEYSZ);
 
@@ -726,7 +730,8 @@ static int __flow_alloc(const char *            dst,
                 goto fail_result;
         }
 
-        if (!recv_msg->has_pid || !recv_msg->has_flow_id)
+        if (!recv_msg->has_pid || !recv_msg->has_flow_id ||
+            !recv_msg->has_mpl)
                 goto fail_result;
 
         if (!join && qs != NULL && qs->cypher_s != 0) {
@@ -747,6 +752,8 @@ static int __flow_alloc(const char *            dst,
         fd = flow_init(recv_msg->flow_id, recv_msg->pid,
                        qs == NULL ? qos_raw : *qs, s);
 
+        mpl = recv_msg->mpl;
+
         irm_msg__free_unpacked(recv_msg, NULL);
 
         if (fd < 0)
@@ -757,7 +764,7 @@ static int __flow_alloc(const char *            dst,
         assert(ai.flows[fd].frcti == NULL);
 
         if (ai.flows[fd].qs.in_order != 0) {
-                ai.flows[fd].frcti = frcti_create(fd, DELT_A, DELT_R, DELT_MPL);
+                ai.flows[fd].frcti = frcti_create(fd, DELT_A, DELT_R, mpl);
                 if (ai.flows[fd].frcti == NULL) {
                         pthread_rwlock_unlock(&ai.lock);
                         flow_dealloc(fd);
@@ -1771,6 +1778,7 @@ int ipcp_create_r(int result)
 int ipcp_flow_req_arr(const uint8_t * dst,
                       size_t          len,
                       qosspec_t       qs,
+                      time_t          mpl,
                       const void *    data,
                       size_t          dlen)
 {
@@ -1789,6 +1797,8 @@ int ipcp_flow_req_arr(const uint8_t * dst,
         msg.hash.data = (uint8_t *) dst;
         qs_msg        = spec_to_msg(&qs);
         msg.qosspec   = &qs_msg;
+        msg.has_mpl   = true;
+        msg.mpl       = mpl;
         msg.has_pk    = true;
         msg.pk.data   = (uint8_t *) data;
         msg.pk.len    = dlen;
@@ -1817,6 +1827,7 @@ int ipcp_flow_req_arr(const uint8_t * dst,
 
 int ipcp_flow_alloc_reply(int          fd,
                           int          response,
+                          time_t       mpl,
                           const void * data,
                           size_t       len)
 {
@@ -1831,6 +1842,8 @@ int ipcp_flow_alloc_reply(int          fd,
         msg.has_pk       = true;
         msg.pk.data      = (uint8_t *) data;
         msg.pk.len       = (uint32_t) len;
+        msg.has_mpl      = true;
+        msg.mpl          = mpl;
 
         pthread_rwlock_rdlock(&ai.lock);
 
diff --git a/src/lib/ipcpd_messages.proto b/src/lib/ipcpd_messages.proto
index a8c3bfb4..4908a3a3 100644
--- a/src/lib/ipcpd_messages.proto
+++ b/src/lib/ipcpd_messages.proto
@@ -53,5 +53,6 @@ message ipcp_msg {
         optional int32 response            = 10;
         optional string comp               = 11;
         optional uint32 timeo_sec          = 12;
-        optional int32 result              = 13;
+        optional sint32 mpl                = 13;
+        optional int32 result              = 14;
 };
diff --git a/src/lib/irmd_messages.proto b/src/lib/irmd_messages.proto
index 515d486f..2173d514 100644
--- a/src/lib/irmd_messages.proto
+++ b/src/lib/irmd_messages.proto
@@ -84,7 +84,8 @@ message irm_msg {
         repeated name_info_msg names  = 16;
         optional uint32 timeo_sec     = 17;
         optional uint32 timeo_nsec    = 18;
-        optional string comp          = 19;
-        optional bytes pk             = 20; /* piggyback */
-        optional sint32 result        = 21;
+        optional sint32 mpl           = 19;
+        optional string comp          = 20;
+        optional bytes pk             = 21; /* piggyback */
+        optional sint32 result        = 22;
 };