irmd: Pass MTU from IPCP to process for FRCT

FRCT needs to know the MTU for fragmentation. The MTU is now passed
from the layer serving the flow to the process as part of flow
allocation.

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

4 files changed, 41 insertions, 0 deletions

diff --git a/src/irmd/main.c b/src/irmd/main.c
index 5a6245e0..ffb07334 100644
--- a/src/irmd/main.c
+++ b/src/irmd/main.c
@@ -87,6 +87,8 @@
 #define OAP_SEEN_TIMER     20   /*  s */
 #define DEALLOC_TIME       300  /*  s */
 #define DIRECT_MPL         1    /*  s */
+/* bytes; in-process, bounded only by PUP/GSPP. */
+#define DIRECT_MTU         65000
 
 enum irm_state {
         IRMD_NULL = 0,
@@ -1216,6 +1218,7 @@ static int flow_alloc_direct(const char *       dst,
 
         acc.n_1_pid = flow->n_pid;
         acc.mpl     = DIRECT_MPL;
+        acc.mtu     = DIRECT_MTU;
         acc.qs      = flow->qs;
         acc.state   = FLOW_ALLOCATED;
 
@@ -1251,6 +1254,7 @@ static int flow_alloc_direct(const char *       dst,
         flow->id      = acc.id;
         flow->n_1_pid = acc.n_pid;
         flow->mpl     = DIRECT_MPL;
+        flow->mtu     = DIRECT_MTU;
         flow->state   = FLOW_ALLOCATED;
 
         log_info("Flow %d allocated (direct) for %d to %s.",
diff --git a/src/irmd/reg/flow.c b/src/irmd/reg/flow.c
index 93c3e128..5c709dea 100644
--- a/src/irmd/reg/flow.c
+++ b/src/irmd/reg/flow.c
@@ -42,6 +42,7 @@ struct reg_flow * reg_flow_create(const struct flow_info * info)
         assert(info->n_pid != 0);
         assert(info->n_1_pid == 0);
         assert(info->mpl == 0);
+        assert(info->mtu == 0);
         assert(info->state == FLOW_INIT);
 
         flow = malloc(sizeof(*flow));
@@ -160,6 +161,7 @@ int reg_flow_update(struct reg_flow *  flow,
                 assert(info->mpl != 0);
 
                 flow->info.mpl = info->mpl;
+                flow->info.mtu = info->mtu;
 
                 if (flow->info.state == FLOW_ALLOC_PENDING)
                         break;
diff --git a/src/irmd/reg/tests/flow_test.c b/src/irmd/reg/tests/flow_test.c
index 7e1c1360..10cd9f3d 100644
--- a/src/irmd/reg/tests/flow_test.c
+++ b/src/irmd/reg/tests/flow_test.c
@@ -122,6 +122,21 @@ static int test_reg_flow_create_has_mpl(void) {
         return TEST_RC_SUCCESS;
 }
 
+static int test_reg_flow_create_has_mtu(void) {
+        struct flow_info info = {
+                .id      = 1,
+                .n_pid   = 1,
+                .n_1_pid = 0,
+                .mtu     = 1400,
+                .qs      = qos_raw,
+                .state   = FLOW_ALLOC_PENDING
+        };
+
+        reg_flow_create(&info); /* assert fail */
+
+        return TEST_RC_SUCCESS;
+}
+
 static int test_reg_flow_update(void)
 {
         struct reg_flow * f;
@@ -210,6 +225,7 @@ static int test_reg_flow_assert_fails(void)
         ret |= test_assert_fail(test_reg_flow_create_has_n_1_pid);
         ret |= test_assert_fail(test_reg_flow_create_wrong_state);
         ret |= test_assert_fail(test_reg_flow_create_has_mpl);
+        ret |= test_assert_fail(test_reg_flow_create_has_mtu);
         ret |= test_assert_fail(test_reg_flow_update_wrong_id);
 
         return ret;
diff --git a/src/irmd/reg/tests/reg_test.c b/src/irmd/reg/tests/reg_test.c
index 5a5178c2..dcc26783 100644
--- a/src/irmd/reg/tests/reg_test.c
+++ b/src/irmd/reg/tests/reg_test.c
@@ -31,6 +31,7 @@
 #define TEST_N_1_PID  3999
 #define TEST_FAKE_ID  9128349
 #define TEST_MPL      5
+#define TEST_MTU      1400
 #define TEST_PROG     "reg_test" /* own binary for binary check */
 #define TEST_IPCP     "testipcp"
 #define TEST_NAME     "testname"
@@ -266,6 +267,7 @@ static int test_reg_accept_flow_success(void)
 
         n_1_info.id  = info.id;
         n_1_info.mpl = 1;
+        n_1_info.mtu = TEST_MTU;
 
         pthread_create(&thr, NULL, test_flow_respond_accept, &n_1_info);
 
@@ -284,6 +286,11 @@ static int test_reg_accept_flow_success(void)
                 goto fail;
         }
 
+        if (info.mtu != TEST_MTU) {
+                printf("MTU not propagated.\n");
+                goto fail;
+        }
+
         if (rbuf.data == NULL) {
                 printf("rbuf data not returned.\n");
                 goto fail;
@@ -363,6 +370,7 @@ static int test_reg_accept_flow_success_no_crypt(void)
 
         n_1_info.id  = info.id;
         n_1_info.mpl = 1;
+        n_1_info.mtu = TEST_MTU;
 
         pthread_create(&thr, NULL, test_flow_respond_accept, &n_1_info);
 
@@ -381,6 +389,11 @@ static int test_reg_accept_flow_success_no_crypt(void)
                 goto fail;
         }
 
+        if (info.mtu != TEST_MTU) {
+                printf("MTU not propagated.\n");
+                goto fail;
+        }
+
         if (rbuf.data == NULL) {
                 printf("rbuf data was not returned.\n");
                 goto fail;
@@ -533,6 +546,7 @@ static int test_reg_respond_alloc_duplicate(void)
 
         n_1_info.id  = info.id;
         n_1_info.mpl = 1;
+        n_1_info.mtu = TEST_MTU;
 
         pthread_create(&thr, NULL, test_flow_respond_alloc, &n_1_info);
 
@@ -547,6 +561,11 @@ static int test_reg_respond_alloc_duplicate(void)
         pthread_join(thr, NULL);
         freebuf(rbuf);
 
+        if (info.mtu != TEST_MTU) {
+                printf("MTU not propagated.\n");
+                goto fail;
+        }
+
         /* Duplicate reply on an already-ALLOCATED flow must not assert. */
         dup_info       = n_1_info;
         dup_info.state = FLOW_DEALLOCATED;