examples/gcoap: add IPv4 support

examples/gcoap/Makefile

@@ -14,17 +14,33 @@ RIOTBASE ?= $(CURDIR)/../..
 USEMODULE += netdev_default
 
 # use GNRC by default
-LWIP ?= 0
+LWIP_IPV4 ?= 0
+LWIP_IPV6 ?= 0
 
-ifeq (0,$(LWIP))
+ifeq (,$(filter 1, $(LWIP_IPV4) $(LWIP_IPV6)))
   USEMODULE += auto_init_gnrc_netif
   # Specify the mandatory networking modules
   USEMODULE += gnrc_ipv6_default
   # Additional networking modules that can be dropped if not needed
   USEMODULE += gnrc_icmpv6_echo
 else
-  USEMODULE += lwip_ipv6
   USEMODULE += lwip_netdev
+
+  ifeq (1,$(LWIP_IPV4))
+    USEMODULE += ipv4_addr
+
+    USEMODULE += lwip_arp
+    USEMODULE += lwip_ipv4
+    USEMODULE += lwip_dhcp_auto
+    CFLAGS += -DETHARP_SUPPORT_STATIC_ENTRIES=1
+  endif
+
+  ifeq (1,$(LWIP_IPV6))
+    USEMODULE += ipv6_addr
+
+    USEMODULE += lwip_ipv6
+    USEMODULE += lwip_ipv6_autoconfig
+  endif
 endif
 
 USEMODULE += gcoap
@@ -33,6 +49,7 @@ USEMODULE += gcoap
 USEMODULE += od
 USEMODULE += fmt
 USEMODULE += netutils
+USEMODULE += random
 # Add also the shell, some shell commands
 USEMODULE += shell
 USEMODULE += shell_cmds_default

examples/gcoap/client.c

@@ -141,18 +141,47 @@ static void _resp_handler(const gcoap_request_memo_t *memo, coap_pkt_t* pdu,
     }
 }
 
-static bool _parse_endpoint(sock_udp_ep_t *remote,
+static bool _parse_endpoint(sock_udp_ep_t *remote, const char *addr_str, const char *port_str)
-                            const char *addr_str, const char *port_str)
 {
-    netif_t *netif;
+    bool is_ipv4 = false;
+    bool is_ipv6 = false;
 
-    /* parse hostname */
+    if (IS_ACTIVE(SOCK_HAS_IPV6)) {
-    if (netutils_get_ipv6((ipv6_addr_t *)&remote->addr, &netif, addr_str) < 0) {
+        netif_t *netif;
+        /* IPv6 might contain '.', but IPv4 cannot contain ':' */
+        if (strstr(addr_str, ":") != NULL) {
+
+            /* parse hostname */
+            if (netutils_get_ipv6((ipv6_addr_t *)&remote->addr, &netif, addr_str) < 0) {
+                puts("gcoap_cli: unable to parse destination ipv6 address");
+                return false;
+            }
+
+            is_ipv6 = true;
+            remote->netif = netif ? netif_get_id(netif) : SOCK_ADDR_ANY_NETIF;
+            remote->family = AF_INET6;
+        }
+    }
+
+    if (IS_ACTIVE(SOCK_HAS_IPV4)) {
+        if (!is_ipv6 && strstr(addr_str, ".") != NULL) { /* IPv4 */
+
+            /* parse hostname */
+            if (netutils_get_ipv4((ipv4_addr_t *)&remote->addr, addr_str) < 0) {
+                puts("gcoap_cli: unable to parse destination ipv4 address");
+                return false;
+            }
+
+            is_ipv4 = true;
+            remote->netif = SOCK_ADDR_ANY_NETIF;
+            remote->family = AF_INET;
+        }
+    }
+
+    if (!is_ipv4 && !is_ipv6) {
         puts("gcoap_cli: unable to parse destination address");
         return false;
     }
-    remote->netif = netif ? netif_get_id(netif) : SOCK_ADDR_ANY_NETIF;
-    remote->family = AF_INET6;
 
     /* parse port */
     remote->port = atoi(port_str);
@@ -223,12 +252,34 @@ int gcoap_cli_cmd(int argc, char **argv)
         printf("CoAP open requests: %u\n", open_reqs);
         printf("Configured Proxy: ");
         if (_proxied) {
+#ifdef SOCK_HAS_IPV6
             char addrstr[IPV6_ADDR_MAX_STR_LEN];
-            printf("[%s]:%u\n",
+#else
-                   ipv6_addr_to_str(addrstr,
+            char addrstr[IPV4_ADDR_MAX_STR_LEN];
-                                    (ipv6_addr_t *) &_proxy_remote.addr.ipv6,
+#endif
-                                    sizeof(addrstr)),
+
-                   _proxy_remote.port);
+            switch (_proxy_remote.family) {
+#ifdef SOCK_HAS_IPV4
+            case AF_INET:
+                printf("%s:%u\n",
+                       ipv4_addr_to_str(addrstr,
+                                        (ipv4_addr_t *) &_proxy_remote.addr.ipv4,
+                                        sizeof(addrstr)),
+                       _proxy_remote.port);
+                break;
+#endif
+#ifdef SOCK_HAS_IPV6
+            case AF_INET6:
+                printf("[%s]:%u\n",
+                       ipv6_addr_to_str(addrstr,
+                                        (ipv6_addr_t *) &_proxy_remote.addr.ipv6,
+                                        sizeof(addrstr)),
+                       _proxy_remote.port);
+                break;
+#endif
+            default:
+                assert(0);
+            }
         }
         else {
             puts("None");
@@ -249,7 +300,15 @@ int gcoap_cli_cmd(int argc, char **argv)
             _proxied = false;
             return 0;
         }
-        printf("usage: %s proxy set <addr>[%%iface] <port>\n", argv[0]);
+
+        if (IS_ACTIVE(SOCK_HAS_IPV4)) {
+            printf("usage: %s proxy set <IPv4 addr> <port>\n", argv[0]);
+        }
+
+        if (IS_ACTIVE(SOCK_HAS_IPV6)) {
+            printf("usage: %s proxy set <IPv6 addr>[%%iface] <port>\n", argv[0]);
+        }
+
         printf("       %s proxy unset\n", argv[0]);
         return 1;
     }
@@ -287,7 +346,14 @@ int gcoap_cli_cmd(int argc, char **argv)
         }
 
         if (_proxied) {
-            uri_len = snprintf(proxy_uri, 64, "coap://[%s]:%s%s", argv[apos], argv[apos+1], uri);
+            /* IPv6 might contain '.', but IPv4 cannot contain ':' */
+            if (strstr(argv[apos], ":") != NULL) {
+                uri_len = snprintf(proxy_uri, 64, "coap://[%s]:%s%s",
+                                   argv[apos], argv[apos+1], uri);
+            }
+            else {
+                uri_len = snprintf(proxy_uri, 64, "coap://%s:%s%s", argv[apos], argv[apos+1], uri);
+            }
             uri = proxy_uri;
 
             gcoap_req_init(&pdu, &buf[0], CONFIG_GCOAP_PDU_BUF_SIZE, code_pos, NULL);
@@ -338,9 +404,18 @@ int gcoap_cli_cmd(int argc, char **argv)
         return 0;
     }
     else {
-        printf("usage: %s <get|post|put> [-c] <addr>[%%iface] <port> <path> [data]\n",
+        if (IS_ACTIVE(SOCK_HAS_IPV4)) {
-               argv[0]);
+            printf("usage: %s <get|post|put> [-c] <IPv4 addr> <port> <path> [data]\n",
-        printf("       %s ping <addr>[%%iface] <port>\n", argv[0]);
+                   argv[0]);
+            printf("       %s ping <IPv4 addr> <port>\n", argv[0]);
+        }
+
+        if (IS_ACTIVE(SOCK_HAS_IPV6)) {
+            printf("usage: %s <get|post|put> [-c] <IPv6 addr>[%%iface] <port> <path> [data]\n",
+                   argv[0]);
+            printf("       %s ping <IPv6 addr>[%%iface] <port>\n", argv[0]);
+        }
+
         printf("Options\n");
         printf("    -c  Send confirmably (defaults to non-confirmable)\n");
         return 1;

sys/Makefile.include

@@ -189,3 +189,7 @@ endif
 ifneq (,$(filter preprocessor_%,$(USEMODULE)))
   include $(RIOTBASE)/sys/preprocessor/Makefile.include
 endif
+
+ifneq (,$(filter gcoap,$(USEMODULE)))
+  include $(RIOTBASE)/sys/net/application_layer/gcoap/Makefile.include
+endif

sys/net/application_layer/gcoap/Makefile.include

@@ -0,0 +1,4 @@
+ifeq (2, $(words $(filter ipv4 ipv6, $(USEMODULE))))
+  $(shell $(COLOR_ECHO) "$(COLOR_YELLOW)Due to limitations in the gcoap API it is currently not \
+                         possible to use a dual stack setup$(COLOR_RESET)" 1>&2)
+endif

sys/net/application_layer/gcoap/gcoap.c

@@ -159,7 +159,17 @@ static void *_event_loop(void *arg)
 
     sock_udp_ep_t local;
     memset(&local, 0, sizeof(sock_udp_ep_t));
+
+    /* FIXME: Once the problems with IPv4/IPv6 dual stack use in RIOT are fixed, adapt these lines
+     *        (and e.g. use AF_UNSPEC) */
+#ifdef SOCK_HAS_IPV4
+    local.family = AF_INET;
+#endif
+
+#ifdef SOCK_HAS_IPV6
     local.family = AF_INET6;
+#endif
+
     local.netif  = SOCK_ADDR_ANY_NETIF;
     local.port = CONFIG_GCOAP_PORT;
     int res = sock_udp_create(&_sock_udp, &local, NULL, 0);
@@ -828,8 +838,20 @@ static int _find_resource(gcoap_socket_type_t tl_type,
 
 static bool _memo_ep_is_multicast(const gcoap_request_memo_t *memo)
 {
-    return memo->remote_ep.family == AF_INET6 &&
+    switch (memo->remote_ep.family) {
-           ipv6_addr_is_multicast((const ipv6_addr_t *)&memo->remote_ep.addr.ipv6);
+#ifdef SOCK_HAS_IPV6
+    case AF_INET6:
+        return ipv6_addr_is_multicast((const ipv6_addr_t *)&memo->remote_ep.addr.ipv6);
+#endif
+#ifdef SOCK_HAS_IPV4
+    case AF_INET:
+        return ipv4_addr_is_multicast((const ipv4_addr_t *)&memo->remote_ep.addr.ipv4);
+#endif
+    default:
+        assert(0);
+    }
+
+    return false;
 }
 
 /*