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Diffstat (limited to 'hicn-light/src/core/wldr.c')
| -rwxr-xr-x | hicn-light/src/core/wldr.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/hicn-light/src/core/wldr.c b/hicn-light/src/core/wldr.c new file mode 100755 index 000000000..b94ae76e5 --- /dev/null +++ b/hicn-light/src/core/wldr.c @@ -0,0 +1,182 @@ +/* + * Copyright (c) 2017-2019 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <parc/assert/parc_Assert.h> +#include <parc/logging/parc_LogReporterTextStdout.h> +#include <src/core/connection.h> +#include <src/core/forwarder.h> +#include <src/core/wldr.h> +#include <stdint.h> +#include <stdio.h> + +struct wldr_buffer { + Message *message; + uint8_t rtx_counter; +}; + +typedef struct wldr_buffer WldrBuffer; + +struct wldr_state { + uint16_t expected_label; + uint16_t next_label; + WldrBuffer *buffer[BUFFER_SIZE]; +}; + +Wldr *wldr_Init() { + Wldr *wldr = parcMemory_AllocateAndClear(sizeof(Wldr)); + parcAssertNotNull(wldr, "parcMemory_AllocateAndClear(%zu) returned NULL", + sizeof(Wldr)); + wldr->expected_label = 1; + wldr->next_label = 1; + for (int i = 0; i < BUFFER_SIZE; i++) { + WldrBuffer *entry = parcMemory_AllocateAndClear(sizeof(WldrBuffer)); + parcAssertNotNull( + entry, + "WldrBuffer init: parcMemory_AllocateAndClear(%zu) returned NULL", + sizeof(WldrBuffer)); + entry->message = NULL; + entry->rtx_counter = 0; + wldr->buffer[i] = entry; + } + return wldr; +} + +void wldr_ResetState(Wldr *wldr) { + wldr->expected_label = 1; + wldr->next_label = 1; + for (int i = 0; i < BUFFER_SIZE; i++) { + wldr->buffer[i]->message = NULL; + wldr->buffer[i]->rtx_counter = 0; + } +} + +void wldr_Destroy(Wldr **wldrPtr) { + Wldr *wldr = *wldrPtr; + for (unsigned i = 0; i < BUFFER_SIZE; i++) { + if (wldr->buffer[i]->message != NULL) { + message_Release(&(wldr->buffer[i]->message)); + parcMemory_Deallocate((void **)&(wldr->buffer[i])); + } + } + parcMemory_Deallocate((void **)&wldr); + *wldrPtr = NULL; +} + +static void _wldr_RetransmitPacket(Wldr *wldr, const Connection *conn, + uint16_t label) { + if (wldr->buffer[label % BUFFER_SIZE]->message == NULL) { + // the required message for retransmission is not in the buffer + return; + } + + if (wldr->buffer[label % BUFFER_SIZE]->rtx_counter < MAX_RTX) { + Message *msg = wldr->buffer[label % BUFFER_SIZE]->message; + message_SetWldrLabel(msg, wldr->next_label); + + if (wldr->buffer[wldr->next_label % BUFFER_SIZE]->message != NULL) { + message_Release(&(wldr->buffer[wldr->next_label % BUFFER_SIZE]->message)); + } + + wldr->buffer[wldr->next_label % BUFFER_SIZE]->message = msg; + wldr->buffer[wldr->next_label % BUFFER_SIZE]->rtx_counter = + wldr->buffer[label % BUFFER_SIZE]->rtx_counter + 1; + message_Acquire(wldr->buffer[wldr->next_label % BUFFER_SIZE]->message); + wldr->next_label++; + connection_ReSend(conn, msg, false); + } +} + +static void _wldr_SendWldrNotificaiton(Wldr *wldr, const Connection *conn, + Message *message, uint16_t expected_lbl, + uint16_t received_lbl) { + // here we need to create a new packet that is used to send the wldr + // notification to the prevoius hop. the destionation address of the + // notification is the source address of the message for which we want to + // create a notification. in fact, if message is an interest the prevoius hop + // is identified by the src. if message is a data, we need to send the + // notification message with the content name has a source address in this way + // the message will be trapped by the pounting rules in the next hop We define + // the notification as an interest message so that the NAT in the send function + // will set the src address of the local connection. Notice that in this way + // the notification packet will be dispaced to the right connection at the next + // hop. + + Message *notification = + message_CreateWldrNotification(message, expected_lbl, received_lbl); + parcAssertNotNull(notification, "Got null from CreateWldrNotification"); + connection_ReSend(conn, notification, true); +} + +void wldr_SetLabel(Wldr *wldr, Message *message) { + // in this function we send the packet for the first time + // 1) we set the wldr label + message_SetWldrLabel(message, wldr->next_label); + + // 2) we store the pointer to packet in the buffer + if (wldr->buffer[wldr->next_label % BUFFER_SIZE]->message != NULL) { + // release an old message if necessary + message_Release(&(wldr->buffer[wldr->next_label % BUFFER_SIZE]->message)); + } + + // we need to acquire the message to avoid that it gets destroyed + message_Acquire(message); + + wldr->buffer[wldr->next_label % BUFFER_SIZE]->message = message; + wldr->buffer[wldr->next_label % BUFFER_SIZE]->rtx_counter = 0; + wldr->next_label++; + if (wldr->next_label == + 0) // we alwasy skip label 0 beacause it means that wldr is not active + wldr->next_label++; +} + +void wldr_DetectLosses(Wldr *wldr, const Connection *conn, Message *message) { + if (message_HasWldr(message)) { + // this is a normal wldr packet + uint16_t pkt_lbl = (uint16_t)message_GetWldrLabel(message); + if (pkt_lbl != wldr->expected_label) { + // if the received packet label is 1 and the expected packet label > + // pkt_lbl usually we are in the case where a remote note disconnected for + // a while and reconnected on this same connection, so the two nodes are + // out of synch for this reason we do not send any notification, we just + // synch the labels + + if ((pkt_lbl != 1) || (wldr->expected_label < pkt_lbl)) { + _wldr_SendWldrNotificaiton(wldr, conn, message, wldr->expected_label, + pkt_lbl); + } + + // here we always synch + wldr->expected_label = (uint16_t)(pkt_lbl + 1); + } else { + wldr->expected_label++; + if (wldr->expected_label == 0) + wldr->expected_label++; // for the next_label we want to skip 0 + } + } +} + +void wldr_HandleWldrNotification(Wldr *wldr, const Connection *conn, + Message *message) { + uint16_t expected_lbl = (uint16_t)message_GetWldrExpectedLabel(message); + uint16_t received_lbl = (uint16_t)message_GetWldrLastReceived(message); + if ((wldr->next_label - expected_lbl) > BUFFER_SIZE) { + // the packets are not in the buffer anymore + return; + } + while (expected_lbl < received_lbl) { + _wldr_RetransmitPacket(wldr, conn, expected_lbl); + expected_lbl++; + } +} |