Merge pull request #4111 from cgundogan/pr/rpl/dao_refactoring_pktbuf

rpl: refactor dao sending to use appropriate pktbuf functions

sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c

@@ -621,13 +621,44 @@ void gnrc_rpl_recv_DIO(gnrc_rpl_dio_t *dio, ipv6_addr_t *src, uint16_t len)
     }
 }
 
-void _dao_fill_target(gnrc_rpl_opt_target_t *target, ipv6_addr_t *addr)
+gnrc_pktsnip_t *_dao_target_build(gnrc_pktsnip_t *pkt, ipv6_addr_t *addr)
 {
+    gnrc_rpl_opt_target_t *target;
+    gnrc_pktsnip_t *opt_snip;
+    if ((opt_snip = gnrc_pktbuf_add(pkt, NULL, sizeof(gnrc_rpl_opt_target_t),
+                               GNRC_NETTYPE_UNDEF)) == NULL) {
+        DEBUG("RPL: Send DAO - no space left in packet buffer\n");
+        gnrc_pktbuf_release(pkt);
+        return NULL;
+    }
+    target = opt_snip->data;
     target->type = GNRC_RPL_OPT_TARGET;
     target->length = sizeof(target->flags) + sizeof(target->prefix_length) + sizeof(target->target);
     target->flags = 0;
     target->prefix_length = 128;
     target->target = *addr;
+    return opt_snip;
+}
+
+gnrc_pktsnip_t *_dao_transit_build(gnrc_pktsnip_t *pkt, uint8_t lifetime)
+{
+    gnrc_rpl_opt_transit_t *transit;
+    gnrc_pktsnip_t *opt_snip;
+    if ((opt_snip = gnrc_pktbuf_add(pkt, NULL, sizeof(gnrc_rpl_opt_transit_t),
+                               GNRC_NETTYPE_UNDEF)) == NULL) {
+        DEBUG("RPL: Send DAO - no space left in packet buffer\n");
+        gnrc_pktbuf_release(pkt);
+        return NULL;
+    }
+    transit = opt_snip->data;
+    transit->type = GNRC_RPL_OPT_TRANSIT;
+    transit->length = sizeof(transit->e_flags) + sizeof(transit->path_control) +
+                      sizeof(transit->path_sequence) + sizeof(transit->path_lifetime);
+    transit->e_flags = 0;
+    transit->path_control = 0;
+    transit->path_sequence = 0;
+    transit->path_lifetime = lifetime;
+    return opt_snip;
 }
 
 void gnrc_rpl_send_DAO(gnrc_rpl_dodag_t *dodag, ipv6_addr_t *destination, uint8_t lifetime)
@@ -653,11 +684,8 @@ void gnrc_rpl_send_DAO(gnrc_rpl_dodag_t *dodag, ipv6_addr_t *destination, uint8_
         destination = &(dodag->parents->addr);
     }
 
-    gnrc_pktsnip_t *pkt;
+    gnrc_pktsnip_t *pkt = NULL, *tmp = NULL;
-    icmpv6_hdr_t *icmp;
     gnrc_rpl_dao_t *dao;
-    gnrc_rpl_opt_target_t *target;
-    gnrc_rpl_opt_transit_t *transit;
 
     /* find my address */
     ipv6_addr_t *me = NULL;
@@ -669,8 +697,8 @@ void gnrc_rpl_send_DAO(gnrc_rpl_dodag_t *dodag, ipv6_addr_t *destination, uint8_
 
     gnrc_ipv6_netif_addr_t *me_netif = gnrc_ipv6_netif_addr_get(me);
     if (me_netif == NULL) {
-        DEBUG("RPL: no netif address found for %s\n", ipv6_addr_to_str(addr_str, me,
+        DEBUG("RPL: no netif address found for %s\n",
-                    sizeof(addr_str)));
+              ipv6_addr_to_str(addr_str, me, sizeof(addr_str)));
         return;
     }
 
@@ -681,30 +709,49 @@ void gnrc_rpl_send_DAO(gnrc_rpl_dodag_t *dodag, ipv6_addr_t *destination, uint8_
     fib_get_destination_set(&gnrc_ipv6_fib_table, prefix.u8,
                             sizeof(ipv6_addr_t), fib_dest_set, &dst_size);
 
-    int size = sizeof(icmpv6_hdr_t) + sizeof(gnrc_rpl_dao_t) +
+    /* add transit option for all target options */
-        (sizeof(gnrc_rpl_opt_target_t) * (dst_size + 1)) + sizeof(gnrc_rpl_opt_transit_t);
+    if ((pkt = _dao_transit_build(pkt, lifetime)) == NULL) {
-
-    bool local_instance = (dodag->instance->id & GNRC_RPL_INSTANCE_ID_MSB) ? true : false;
-
-    if (local_instance) {
-        size += sizeof(ipv6_addr_t);
-    }
-
-    if ((pkt = gnrc_icmpv6_build(NULL, ICMPV6_RPL_CTRL, GNRC_RPL_ICMPV6_CODE_DAO, size)) == NULL) {
         DEBUG("RPL: Send DAO - no space left in packet buffer\n");
         return;
     }
 
-    icmp = (icmpv6_hdr_t *)pkt->data;
+    /* add children */
-    dao = (gnrc_rpl_dao_t *)(icmp + 1);
+    for (size_t i = 0; i < dst_size; ++i) {
-    target = (gnrc_rpl_opt_target_t *) (dao + 1);
+        if ((pkt = _dao_target_build(pkt, ((ipv6_addr_t *) fib_dest_set[i].dest))) == NULL) {
+            DEBUG("RPL: Send DAO - no space left in packet buffer\n");
+            return;
+        }
+    }
 
+    /* add own address */
+    if ((pkt = _dao_target_build(pkt, me)) == NULL) {
+        DEBUG("RPL: Send DAO - no space left in packet buffer\n");
+        return;
+    }
+
+    bool local_instance = (dodag->instance->id & GNRC_RPL_INSTANCE_ID_MSB) ? true : false;
+
+    if (local_instance) {
+        if ((tmp = gnrc_pktbuf_add(pkt, &dodag->dodag_id, sizeof(ipv6_addr_t),
+                                   GNRC_NETTYPE_UNDEF)) == NULL) {
+            DEBUG("RPL: Send DAO - no space left in packet buffer\n");
+            gnrc_pktbuf_release(pkt);
+            return;
+        }
+        pkt = tmp;
+    }
+
+    if ((tmp = gnrc_pktbuf_add(pkt, NULL, sizeof(gnrc_rpl_dao_t), GNRC_NETTYPE_UNDEF)) == NULL) {
+        DEBUG("RPL: Send DAO - no space left in packet buffer\n");
+        gnrc_pktbuf_release(pkt);
+        return;
+    }
+    pkt = tmp;
+    dao = pkt->data;
     dao->instance_id = dodag->instance->id;
     if (local_instance) {
         /* set the D flag to indicate that a DODAG id is present */
         dao->k_d_flags = GNRC_RPL_DAO_D_BIT;
-        memcpy((dao + 1), &dodag->dodag_id, sizeof(ipv6_addr_t));
-        target = (gnrc_rpl_opt_target_t *)(((uint8_t *) target) + sizeof(ipv6_addr_t));
     }
     else {
         dao->k_d_flags = 0;
@@ -715,23 +762,12 @@ void gnrc_rpl_send_DAO(gnrc_rpl_dodag_t *dodag, ipv6_addr_t *destination, uint8_
     dao->dao_sequence = dodag->dao_seq;
     dao->reserved = 0;
 
-    /* add own address */
+    if ((tmp = gnrc_icmpv6_build(pkt, ICMPV6_RPL_CTRL, GNRC_RPL_ICMPV6_CODE_DAO,
-    _dao_fill_target(target, me);
+                                 sizeof(icmpv6_hdr_t))) == NULL) {
-
+        DEBUG("RPL: Send DAO - no space left in packet buffer\n");
-    /* add children */
+        return;
-    for (size_t i = 0; i < dst_size; ++i) {
-        target = (target + 1);
-        _dao_fill_target(target, ((ipv6_addr_t *) fib_dest_set[i].dest));
     }
-
+    pkt = tmp;
-    transit = (gnrc_rpl_opt_transit_t *) (target + 1);
-    transit->type = GNRC_RPL_OPT_TRANSIT;
-    transit->length = sizeof(transit->e_flags) + sizeof(transit->path_control) +
-        sizeof(transit->path_sequence) + sizeof(transit->path_lifetime);
-    transit->e_flags = 0;
-    transit->path_control = 0;
-    transit->path_sequence = 0;
-    transit->path_lifetime = lifetime;
 
     gnrc_rpl_send(pkt, NULL, destination, &dodag->dodag_id);