Merge pull request #14755 from benpicco/examples/gnrc_border_router-native

examples/gnrc_border_route: simplify ZEP setup on native

cpu/native/include/socket_zep.h

@@ -13,6 +13,39 @@
  *
  * @see @ref net_zep for protocol definitions
  *
+ * This ZEP implementation can send a dummy HELLO packet on startup.
+ * This is used to make dispatchers aware of the node.
+ * To enable this behavior, add
+ *
+ * ```
+ * USEMODULE += socket_zep_hello
+ * ```
+ *
+ * to your Makefile.
+ *
+ * A ZEP dispatcher can just drop those packets (ZEP type 0xFF) if it
+ * chooses to parse the ZEP header.
+ *
+ * The header of the HELLO packet will look like this:
+ *
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |         Preamble (EX)         |  Version (2)  |  Type  (255)  |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |                                                               |
+ *     +                                                               +
+ *     |                                                               |
+ *     +                         Reserved (0)                         +
+ *     |                                                               |
+ *     +                                                               +
+ *     |                                                               |
+ *     +               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |               |      'H'      |      'E'      |      'L'      |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |      'L'      |      'O'      |       0       |       0       |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |       0       |       0       |       0       |       0       |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
  * @{
  *
  * @file

cpu/native/socket_zep/socket_zep.c

@@ -40,6 +40,9 @@
  * (https://pubs.opengroup.org/onlinepubs/9699919799.2016edition/basedefs/time.h.html) */
 #define TV_USEC_PER_SEC         (1000000L)
 
+/* dummy packet to register with ZEP dispatcher */
+#define SOCKET_ZEP_V2_TYPE_HELLO   (255)
+
 static size_t _zep_hdr_fill_v2_data(socket_zep_t *dev, zep_v2_data_hdr_t *hdr,
                                     size_t payload_len)
 {
@@ -390,6 +393,21 @@ static int _connect_remote(socket_zep_t *dev, const socket_zep_params_t *params)
     return res;
 }
 
+static void _send_zep_hello(socket_zep_t *dev)
+{
+    if (IS_USED(MODULE_SOCKET_ZEP_HELLO)) {
+        /* dummy packet */
+        zep_v2_data_hdr_t hdr = {
+            .hdr.preamble = "EX",
+            .hdr.version  = 2,
+            .type = SOCKET_ZEP_V2_TYPE_HELLO,
+            .resv = "HELLO",
+        };
+
+        real_write(dev->sock_fd, &hdr, sizeof(hdr));
+    }
+}
+
 void socket_zep_setup(socket_zep_t *dev, const socket_zep_params_t *params)
 {
     int res;
@@ -408,7 +426,10 @@ void socket_zep_setup(socket_zep_t *dev, const socket_zep_params_t *params)
         dev->sock_fd = res;
     }
 
-    _connect_remote(dev, params);
+    if (_connect_remote(dev, params) == 0) {
+        /* send dummy data to connect to dispatcher */
+        _send_zep_hello(dev);
+    }
 
     /* generate hardware address from local address */
     uint8_t ss_array[sizeof(struct sockaddr_storage)] = { 0 };

dist/tools/Makefile

@@ -1,4 +1,4 @@
-HOST_TOOLS=ethos uhcpd sliptty
+HOST_TOOLS=ethos uhcpd sliptty zep_dispatch
 
 .PHONY: all $(HOST_TOOLS)
 

dist/tools/zep_dispatch/Makefile

@@ -0,0 +1,16 @@
+CFLAGS?=-g -O3 -Wall -Wextra
+
+BINARY := bin/zep_dispatch
+all: bin $(BINARY)
+
+bin:
+	mkdir bin
+
+RIOTBASE:=../../..
+RIOT_INCLUDE=$(RIOTBASE)/core/include
+SRCS:=$(wildcard *.c)
+$(BINARY): $(SRCS)
+	$(CC) $(CFLAGS) $(CFLAGS_EXTRA) -I$(RIOT_INCLUDE) $(SRCS) -o $@
+
+clean:
+	rm -f $(BINARY)

dist/tools/zep_dispatch/main.c

@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2020 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License v2. See the file LICENSE for more details.
+ */
+
+#ifndef ZEP_DISPATCH_PDU
+#define ZEP_DISPATCH_PDU    256
+#endif
+
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "list.h"
+#include "kernel_defines.h"
+
+typedef struct {
+    list_node_t node;
+    struct sockaddr_in6 addr;
+} zep_client_t;
+
+static void dispatch_loop(int sock)
+{
+    list_node_t head = { .next = NULL };
+
+    puts("entering loop…");
+    while (1) {
+        char addr_str[INET6_ADDRSTRLEN];
+        uint8_t buffer[ZEP_DISPATCH_PDU];
+        struct sockaddr_in6 src_addr;
+        socklen_t addr_len = sizeof(src_addr);
+
+        /* receive incoming packet */
+        ssize_t bytes_in = recvfrom(sock, buffer, sizeof(buffer), 0,
+                               (struct sockaddr*)&src_addr, &addr_len);
+
+        if (bytes_in <= 0 || addr_len != sizeof(src_addr)) {
+            continue;
+        }
+
+        /* send packet to all other clients */
+        bool known_node = false;
+        list_node_t *prev = &head;
+        for (list_node_t* n = head.next; n; n = n->next) {
+            struct sockaddr_in6 *addr = &container_of(n, zep_client_t, node)->addr;
+
+            /* don't echo packet back to sender */
+            if (memcmp(&src_addr, addr, addr_len) == 0) {
+                known_node = true;
+            /* remove client if sending fails */
+            } else if (sendto(sock, buffer, bytes_in, 0, (struct sockaddr*)addr, addr_len) < 0) {
+                inet_ntop(AF_INET6, &addr->sin6_addr, addr_str, INET6_ADDRSTRLEN);
+                printf("removing [%s]:%d\n", addr_str, ntohs(addr->sin6_port));
+                prev->next = n->next;
+                free(n);
+                continue;
+            }
+
+            prev = n;
+        }
+
+        /* if the client new, add it to the broadcast list */
+        if (!known_node) {
+            inet_ntop(AF_INET6, &src_addr.sin6_addr, addr_str, INET6_ADDRSTRLEN);
+            printf("adding [%s]:%d\n", addr_str, ntohs(src_addr.sin6_port));
+            zep_client_t *client = malloc(sizeof(zep_client_t));
+            memcpy(&client->addr, &src_addr, addr_len);
+            list_add(&head, &client->node);
+        }
+    }
+}
+
+int main(int argc, char **argv)
+{
+    if (argc < 3) {
+        fprintf(stderr, "usage: %s <address> <port>\n",
+                argv[0]);
+        exit(1);
+    }
+
+    struct addrinfo hint = {
+        .ai_family   = AF_INET6,
+        .ai_socktype = SOCK_DGRAM,
+        .ai_protocol = IPPROTO_UDP,
+        .ai_flags    = AI_NUMERICHOST,
+    };
+
+    struct addrinfo *server_addr;
+    int res = getaddrinfo(argv[1], argv[2],
+                          &hint, &server_addr);
+    if (res != 0) {
+        perror("getaddrinfo()");
+        exit(1);
+    }
+
+    int sock = socket(server_addr->ai_family, server_addr->ai_socktype,
+                      server_addr->ai_protocol);
+    if (sock < 0) {
+        perror("socket() failed");
+        exit(1);
+    }
+
+    if (bind(sock, server_addr->ai_addr, server_addr->ai_addrlen) < 0) {
+        perror("bind() failed");
+        exit(1);
+    }
+
+    freeaddrinfo(server_addr);
+
+    dispatch_loop(sock);
+
+    close(sock);
+
+    return 0;
+}

dist/tools/zep_dispatch/start_network.sh

@@ -0,0 +1,99 @@
+#!/usr/bin/env bash
+
+ZEP_DISPATCH_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+UHCPD="$(cd "${ZEP_DISPATCH_DIR}/../uhcpd/bin" && pwd -P)/uhcpd"
+DHCPD="$(cd "${ZEP_DISPATCH_DIR}/../dhcpv6-pd_ia/" && pwd -P)/dhcpv6-pd_ia.py"
+ZEP_DISPATCH="${ZEP_DISPATCH_DIR}/bin/zep_dispatch"
+
+TAP_GLB="fdea:dbee:f::1/64"
+
+NOSUDO="sudo -u ${SUDO_USER}"
+
+create_tap() {
+    ip tuntap add "${TAP}" mode tap user "${SUDO_USER}"
+    sysctl -w net.ipv6.conf."${TAP}".forwarding=1
+    sysctl -w net.ipv6.conf."${TAP}".accept_ra=0
+    ip link set "${TAP}" up
+    ip a a fe80::1/64 dev "${TAP}"
+    ip a a ${TAP_GLB} dev "${TAP}"
+    ip route add "${PREFIX}" via fe80::2 dev "${TAP}"
+}
+
+remove_tap() {
+    ip tuntap del "${TAP}" mode tap
+}
+
+cleanup() {
+    echo "Cleaning up..."
+    remove_tap
+    if [ -n "${UHCPD_PID}" ]; then
+        kill "${UHCPD_PID}"
+    fi
+    if [ -n "${ZEP_DISPATCH_PID}" ]; then
+        kill "${ZEP_DISPATCH_PID}"
+    fi
+    if [ -n "${DHCPD_PIDFILE}" ]; then
+        kill "$(cat "${DHCPD_PIDFILE}")"
+        rm "${DHCPD_PIDFILE}"
+    fi
+    trap "" INT QUIT TERM EXIT
+}
+
+start_uhcpd() {
+    ${UHCPD} "${TAP}" "${PREFIX}" > /dev/null &
+    UHCPD_PID=$!
+}
+
+start_dhcpd() {
+    DHCPD_PIDFILE=$(mktemp)
+    ${DHCPD} -d -p "${DHCPD_PIDFILE}" "${TAP}" "${PREFIX}" 2> /dev/null
+}
+
+start_zep_dispatch() {
+    ${ZEP_DISPATCH} :: "${ZEP_PORT_BASE}" > /dev/null &
+    ZEP_DISPATCH_PID=$!
+}
+
+if [ "$1" = "-d" ] || [ "$1" = "--use-dhcpv6" ]; then
+    USE_DHCPV6=1
+    shift 1
+else
+    USE_DHCPV6=0
+fi
+
+if [ "$1" = "-z" ] || [ "$1" = "--use-zep-dispatch" ]; then
+    USE_ZEP_DISPATCH=1
+    ZEP_PORT_BASE=$2
+    shift 2
+else
+    USE_ZEP_DISPATCH=0
+fi
+
+ELFFILE=$1
+PREFIX=$2
+shift 2
+
+# tap will be the last argument
+for TAP in "$@"; do :; done
+
+[[ -z "${ELFFILE}" || -z "${PREFIX}" || -z "${TAP}" ]] && {
+    echo "usage: $0 [-d|--use-dhcp] [-z|--use-zep <port>] " \
+         "<elffile> <prefix> [elf args]"
+    exit 1
+}
+
+trap "cleanup" INT QUIT TERM EXIT
+
+create_tap
+
+if [ ${USE_ZEP_DISPATCH} -eq 1 ]; then
+    start_zep_dispatch
+fi
+
+if [ ${USE_DHCPV6} -eq 1 ]; then
+    start_dhcpd
+else
+    start_uhcpd
+fi
+
+${NOSUDO} "${ELFFILE}" "${TAP}" "$@"

examples/gnrc_border_router/Makefile.board.dep

@@ -14,4 +14,5 @@ ifeq (,$(filter native,$(BOARD)))
   endif
 else
   USEMODULE += socket_zep
+  USEMODULE += socket_zep_hello
 endif

examples/gnrc_border_router/Makefile.native.conf

@@ -9,11 +9,17 @@ CFLAGS += -DASYNC_READ_NUMOF=$(shell expr $(ZEP_DEVICES) + 1)
 # Set CFLAGS if not being set via Kconfig
 CFLAGS += $(if $(CONFIG_KCONFIG_MODULE_DHCPV6),,-DCONFIG_DHCPV6_CLIENT_PFX_LEASE_MAX=$(ZEP_DEVICES))
 
-# -z [::1]:$PORT for each ZEP device
-TERMFLAGS += $(patsubst %,-z [::1]:%, $(shell seq $(ZEP_PORT_BASE) $(ZEP_PORT_MAX)))
-
-ifneq (1,$(USE_DHCPV6))
-  # We don't need to start ethos so just start the UHCPD daemon in the
-  # background
-  TERMDEPS += uhcpd-daemon
+ifeq (1,$(USE_DHCPV6))
+  FLAGS_EXTRAS += --use-dhcpv6
 endif
+
+# enable the ZEP dispatcher
+FLAGS_EXTRAS += -z $(ZEP_PORT_BASE)
+
+# Configure terminal parameters
+TERMDEPS += host-tools
+TERMPROG_FLAGS = $(FLAGS_EXTRAS) $(ELFFILE) $(IPV6_PREFIX)
+TERMPROG ?= sudo $(RIOTTOOLS)/zep_dispatch/start_network.sh $(TERMPROG_FLAGS)
+
+# -z [::1]:$PORT for each ZEP device
+TERMFLAGS ?= $(patsubst %,-z [::1]:%, $(shell seq $(ZEP_PORT_BASE) $(ZEP_PORT_MAX)))

examples/gnrc_border_router/README.md

@@ -24,6 +24,8 @@ This example comes with support for three uplink types pre-configured:
 
 For `native` the host-facing [`netdev_tap`](https://doc.riot-os.org/netdev__tap_8h.html) device
 is configured, providing connectivity via a TAP interface to the RIOT instance.
+On the node-facing side [`socket_zep`](https://doc.riot-os.org/group__drivers__socket__zep.html)
+is used to simulate a IEEE 802.15.4 network.
 
 To select an uplink, set the UPLINK environment variable. For instance, use `UPLINK=slip`
 for a SLIP uplink.
@@ -143,6 +145,17 @@ On this example, such address can be pinged from 6lo motes:
 
 Thus far, IPv6 communication with between your PC and your motes is enabled.
 
+### Simulated network with native
+
+On native a IEEE 802.15.4 network is simulated by encapsulating 802.15.4 frames
+inside UDP packets. For this the `socket_zep` modules is used both on the border
+router and on the virtual mote.
+
+The UDP packets are sent to a dispatcher which forwards them to all other nodes.
+By default a simple dispatcher is provided that will forward every packet to
+every node (perfect broadcast), but it can be replaced by the user with alternative
+dispatchers to simulate more advanced topologies.
+
 # gnrc_border_router with manual config
 You can use `ethos` as a standalone driver, if you want to setup the BR manually.
 

examples/gnrc_networking/Makefile

@@ -36,6 +36,17 @@ USEMODULE += netstats_rpl
 # development process:
 DEVELHELP ?= 1
 
+# Instead of simulating an Ethernet connection, we can also simulate
+# an IEEE 802.15.4 radio using ZEP
+USE_ZEP ?= 0
+
+# set the ZEP port for native
+ZEP_PORT_BASE ?= 17754
+ifeq (1,$(USE_ZEP))
+  TERMFLAGS += -z [::1]:$(ZEP_PORT_BASE)
+  USEMODULE += socket_zep
+endif
+
 # Uncomment the following 2 lines to specify static link lokal IPv6 address
 # this might be useful for testing, in cases where you cannot or do not want to
 # run a shell with ifconfig to get the real link lokal address.

makefiles/pseudomodules.inc.mk

@@ -118,6 +118,7 @@ PSEUDOMODULES += sock_dtls
 PSEUDOMODULES += sock_ip
 PSEUDOMODULES += sock_tcp
 PSEUDOMODULES += sock_udp
+PSEUDOMODULES += socket_zep_hello
 PSEUDOMODULES += soft_uart_modecfg
 PSEUDOMODULES += stdin
 PSEUDOMODULES += stdio_cdc_acm