Added a hello-world example for Open1722

Signed-off-by: Naresh Nayak <[email protected]>

CMakeLists.txt

@@ -82,6 +82,16 @@ add_executable(cvf-listener "examples/cvf/cvf-listener.c")
 target_include_directories(cvf-listener PRIVATE "examples" "include")
 target_link_libraries(cvf-listener open1722 open1722examples)
 
+# Hello-world talker app
+add_executable(hello-world-talker "examples/hello-world/hello-world-talker.c")
+target_include_directories(hello-world-talker PRIVATE "examples" "include")
+target_link_libraries(hello-world-talker open1722 open1722examples)
+
+# Hello-world listener app
+add_executable(hello-world-listener "examples/hello-world/hello-world-listener.c")
+target_include_directories(hello-world-listener PRIVATE "examples" "include")
+target_link_libraries(hello-world-listener open1722 open1722examples)
+
 #### Tests ####################################################################
 
 enable_testing()

examples/hello-world/README.md

@@ -0,0 +1,35 @@
+# Hello World!
+
+The hello-world applications provide an exemplary set of listener and talker based on the IEEE 1722 protocol.
+These applications are based on the Genereal Purpose Control (GPC) subtype of the AVTP Control Formats.
+
+## hello-world-talker
+_hello-world-talker_ sends the string "Hello World!" packed in a GPC frame of AVTP Control Format.
+The string being sent can be changed using the ```--message``` option.
+Options are available to send the IEEE 1722 frame as layer 2 frame or as a UDP segment.
+
+To run over Ethernet
+```
+$ ./hello-world-talker <Ethernet interface name> <Destination MAC address>
+```
+
+To run over UDP
+```
+$ ./hello-world-talker --udp <destination IP>:<Port>
+```
+
+By running wireshark on an appropriate interface, IEEE 1722 frames can be observed.
+
+
+## hello-world-listener
+_hello-world-listener_ receives the message string sent by the talker and prints it out on the console. The listener shall be operated in the same configuration (e.g. layer 2 or UDP) as the talker to ensure compatability.
+
+To run over Ethernet
+```
+$ ./hello-world-listener <Ethernet interface name>
+```
+
+To run over UDP
+```
+$ ./hello-world-talker --udp <--port=<UDP port>
+```

examples/hello-world/hello-world-listener.c

@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2024, COVESA
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *    * Redistributions of source code must retain the above copyright notice,
+ *      this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *    * Neither the name of COVESA nor the names of its contributors may be
+ *      used to endorse or promote products derived from this software without
+ *      specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <argp.h>
+#include <stdlib.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include "common/common.h"
+#include "avtp/Udp.h"
+#include "avtp/acf/Ntscf.h"
+#include "avtp/acf/Tscf.h"
+#include "avtp/acf/Common.h"
+#include "avtp/acf/Gpc.h"
+#include "avtp/CommonHeader.h"
+
+#define MAX_PDU_SIZE                1500
+#define MAX_MSG_SIZE                100
+
+static char ifname[IFNAMSIZ];
+static uint8_t macaddr[ETH_ALEN];
+static uint8_t use_udp;
+static uint32_t udp_port = 17220;
+
+static struct argp_option options[] = {
+    {"port", 'p', "UDP_PORT", 0, "UDP Port to listen on if UDP enabled"},
+    {"udp", 'u', 0, 0, "Use UDP"},
+    {"dst-mac-address", 0, 0, OPTION_DOC, "Stream destination MAC address (If Ethernet)"},
+    {"ifname", 0, 0, OPTION_DOC, "Network interface (If Ethernet)" },
+    { 0 }
+};
+
+static error_t parser(int key, char *arg, struct argp_state *state)
+{
+    int res;
+
+    switch (key) {
+    case 'p':
+        udp_port = atoi(arg);
+        break;
+    case 'u':
+        use_udp = 1;
+        break;
+
+    case ARGP_KEY_NO_ARGS:
+        break;
+
+    case ARGP_KEY_ARG:
+
+        if(state->argc < 2){
+            argp_usage(state);
+        }
+
+        if(!use_udp){
+
+            strncpy(ifname, arg, sizeof(ifname) - 1);
+
+            if(state->next < state->argc)
+            {
+                res = sscanf(state->argv[state->next], "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
+                        &macaddr[0], &macaddr[1], &macaddr[2],
+                        &macaddr[3], &macaddr[4], &macaddr[5]);
+                if (res != 6) {
+                    fprintf(stderr, "Invalid MAC address\n\n");
+                    argp_usage(state);
+                }
+                state->next += 1;
+            }
+        }
+
+        break;
+    }
+
+    return 0;
+}
+
+static struct argp argp = { options, parser, 0, 0};
+
+int main(int argc, char *argv[])
+{
+    int sk_fd, res;
+    uint64_t msg_length, proc_bytes = 0, msg_proc_bytes = 0;
+    uint64_t udp_seq_num, subtype, flag, acf_type, pdu_length;
+    uint8_t pdu[MAX_PDU_SIZE];
+    uint8_t *cf_pdu, *acf_pdu, *udp_pdu;
+    uint64_t gpc_code;
+    char *recd_msg;
+
+    argp_parse(&argp, argc, argv, 0, NULL, NULL);
+
+    if (use_udp) {
+        sk_fd = create_listener_socket_udp(udp_port);
+    } else {
+        sk_fd = create_listener_socket(ifname, macaddr, ETH_P_TSN);
+    }
+
+    if (sk_fd < 0)
+        return 1;
+
+    while (1) {
+        proc_bytes = 0;
+
+        res = recv(sk_fd, pdu, MAX_PDU_SIZE, 0);
+        if (res < 0 || res > MAX_PDU_SIZE) {
+            perror("Failed to receive data");
+            goto err;
+        }
+
+        // If UDP is used the packets starts with an encapsulation number
+        if (use_udp) {
+            udp_pdu = pdu;
+            Avtp_Udp_GetField((Avtp_Udp_t *)udp_pdu, AVTP_UDP_FIELD_ENCAPSULATION_SEQ_NO, &udp_seq_num);
+            cf_pdu = pdu + AVTP_UDP_HEADER_LEN;
+            proc_bytes += AVTP_UDP_HEADER_LEN;
+        } else {
+            cf_pdu = pdu;
+        }
+
+        // Check if the packet is a control format packet (i.e. NTSCF or TSCF)
+        res = Avtp_CommonHeader_GetField((Avtp_CommonHeader_t*)cf_pdu, AVTP_COMMON_HEADER_FIELD_SUBTYPE, &subtype);
+        if (res < 0) {
+            fprintf(stderr, "Failed to get subtype field: %d\n", res);
+            goto err;
+        }
+        if(subtype == AVTP_SUBTYPE_TSCF){
+            proc_bytes += AVTP_TSCF_HEADER_LEN;
+            Avtp_Tscf_GetField((Avtp_Tscf_t*)cf_pdu, AVTP_TSCF_FIELD_STREAM_DATA_LENGTH, (uint64_t *) &msg_length);
+        }else{
+            proc_bytes += AVTP_NTSCF_HEADER_LEN;
+            Avtp_Ntscf_GetField((Avtp_Ntscf_t*)cf_pdu, AVTP_NTSCF_FIELD_NTSCF_DATA_LENGTH, (uint64_t *) &msg_length);
+        }
+
+        // Check if the control packet payload is a ACF GPC.
+        acf_pdu = &pdu[proc_bytes];
+        Avtp_AcfCommon_GetField((Avtp_AcfCommon_t*)acf_pdu, AVTP_ACF_FIELD_ACF_MSG_TYPE, &acf_type);
+        if (acf_type != AVTP_ACF_TYPE_GPC) {
+            fprintf(stderr, "ACF type mismatch: expected %u, got %lu\n",
+                    AVTP_ACF_TYPE_GPC, acf_type);
+            continue;
+        }
+
+        // Parse the GPC Packet and print contents on the STDOUT
+        Avtp_Gpc_GetField((Avtp_Gpc_t*)acf_pdu, AVTP_GPC_FIELD_GPC_MSG_ID, &gpc_code);
+        Avtp_Gpc_GetField((Avtp_Gpc_t*)acf_pdu, AVTP_GPC_FIELD_ACF_MSG_LENGTH, &pdu_length);
+        if (pdu_length * 4 <= MAX_MSG_SIZE) {
+            recd_msg = acf_pdu + AVTP_GPC_HEADER_LEN;
+            printf("%s : GPC Code %ld\n", recd_msg, gpc_code);
+        }
+    }
+
+    return 0;
+
+err:
+    close(sk_fd);
+    return 1;
+
+}