Merge pull request #13275 from miri64/gnrc_ipv6_ext_opt/feat/initial

gnrc_ipv6_ext_opt: initial import

Makefile.dep

@@ -330,6 +330,10 @@ ifneq (,$(filter gnrc_ipv6_ext_frag,$(USEMODULE)))
   USEMODULE += xtimer
 endif
 
+ifneq (,$(filter gnrc_ipv6_ext_opt,$(USEMODULE)))
+  USEMODULE += gnrc_ipv6_ext
+endif
+
 ifneq (,$(filter gnrc_ipv6_ext_rh,$(USEMODULE)))
   USEMODULE += gnrc_ipv6_ext
 endif

sys/include/net/gnrc/ipv6/ext/opt.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2020 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    net_gnrc_ipv6_ext_opt Support for IPv6 option extension headers
+ * @ingroup     net_gnrc_ipv6_ext
+ * @brief       GNRC implementation of IPv6 hop-by-hop and destination option
+ *              header extension
+ * @{
+ *
+ * @file
+ * @brief   GNRC hop-by-hop and destination option header definitions.
+ *
+ * @author  Martine Lenders <[email protected]>
+ */
+#ifndef NET_GNRC_IPV6_EXT_OPT_H
+#define NET_GNRC_IPV6_EXT_OPT_H
+
+#include <stdint.h>
+
+#include "net/gnrc/pkt.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   Processes all options within an IPv6 option header
+ *
+ * @pre `pkt != NULL`
+ * @pre `(protnum == PROTNUM_IPV6_EXT_HOPOPT) || (protnum == PROTNUM_IPV6_EXT_DST)`
+ *
+ * @param[in] pkt       The packet containing the option header. The option
+ *                      must be contained in the first snip, with all
+ *                      preceding headers marked (in receive order).
+ *                      Must not be NULL.
+ * @param[in] protnum   The protocol number of the option header. Must be
+ *                      @ref PROTNUM_IPV6_EXT_HOPOPT or @ref
+ *                      PROTNUM_IPV6_EXT_DST
+ *
+ * @return  @p pkt with the option header marked on success.
+ * @return  NULL, if the packet was consumed by the option handling.
+ * @return  NULL, on error. @p pkt is released with EINVAL in that case and if
+ *          necessary and [`gnrc_icmpv6_error`](@ref net_gnrc_icmpv6_error) is
+ *          used, the according ICMPv6 error message is sent.
+ */
+gnrc_pktsnip_t *gnrc_ipv6_ext_opt_process(gnrc_pktsnip_t *pkt,
+                                          uint8_t protnum);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NET_GNRC_IPV6_EXT_OPT_H */
+/** @} */

sys/include/net/ipv6/ext/opt.h

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2020 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    net_ipv6_ext_opt IPv6 destination and hop-by-hop options
+ * @ingroup     net_ipv6_ext
+ * @brief       Definitions for IPv6 destination and hop-by-hop options
+ *              extension headers
+ * @{
+ *
+ * @file
+ * @brief   Destination and hop-by-hop options extension header definitions.
+ *
+ * @author  Martine Lenders <[email protected]>
+ */
+#ifndef NET_IPV6_EXT_OPT_H
+#define NET_IPV6_EXT_OPT_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @name Destination and hop-by-hop option types
+ * @see [IANA, IPv6 parameters]
+ *      (https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#ipv6-parameters-2)
+ * @{
+ */
+#define IPV6_EXT_OPT_PAD1           (0x00U) /**< Pad1 */
+#define IPV6_EXT_OPT_PADN           (0x01U) /**< PadN */
+#define IPV6_EXT_OPT_JUMBO          (0xC2U) /**< Jumbo payload */
+#define IPV6_EXT_OPT_RPL            (0x63U) /**< RPL Option */
+#define IPV6_EXT_OPT_TEL            (0x04U) /**< Tunnel Encapsulation Limit */
+#define IPV6_EXT_OPT_RTR_ALERT      (0x05U) /**< Router Alert */
+#define IPV6_EXT_OPT_QUICK_START    (0x26U) /**< Quick-Start */
+#define IPV6_EXT_OPT_CALIPSO        (0x07U) /**< CALIPSO */
+#define IPV6_EXT_OPT_SMF_DPD        (0x08U) /**< SMF_DPD */
+#define IPV6_EXT_OPT_HOME_ADDR      (0xC9U) /**< Home Address */
+#define IPV6_EXT_OPT_ILNP_NONCE     (0x8BU) /**< ILNP Nonce */
+#define IPV6_EXT_OPT_LIO            (0x8CU) /**< Line-Identification Option */
+#define IPV6_EXT_OPT_MPL            (0x6DU) /**< MPL Option */
+#define IPV6_EXT_OPT_IP_DFF         (0xEEU) /**< IP_DFF */
+#define IPV6_EXT_OPT_PDM            (0x0FU) /**< Performance and Diagnostic Metrics */
+/** @} */
+
+/**
+ * @name Processing actions
+ * @see [RFC 8200, section 4.2](https://tools.ietf.org/html/rfc8200#section-4.2)
+ *
+ * > The Option Type identifiers are internally encoded such that their
+ * > highest-order 2 bits specify the action that must be taken if the
+ * > processing IPv6 node does not recognize the Option Type
+ * @{
+ */
+/**
+ * @brief   mask to decode action from type
+ */
+#define IPV6_EXT_OPT_ACTION_MASK            (0xc0)
+/**
+ * @brief   skip over this option and continue processing the header
+ */
+#define IPV6_EXT_OPT_ACTION_SKIP            (0x00)
+#define IPV6_EXT_OPT_ACTION_DISC            (0x40)  /**< discard the packet */
+/**
+ * @brief   discard the packet
+ *
+ * > and, regardless of whether or not the packet's Destination Address
+ * > was a multicast address, send an ICMP Parameter Problem, Code 2,
+ * > message to the packet's Source Address, pointing to the
+ * > unrecognized Option Type.
+ */
+#define IPV6_EXT_OPT_ACTION_DISC_ERR_MCAST  (0x80)
+
+/**
+ * @brief   discard the packet
+ *
+ * > and, only if the packet's Destination Address was not a multicast
+ * > address, send an ICMP Parameter Problem, Code 2, message to the
+ * > packet's Source Address, pointing to the unrecognized Option Type.
+ */
+#define IPV6_EXT_OPT_ACTION_DISC_ERR        (0xc0)
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NET_IPV6_EXT_OPT_H */
+/** @} */

sys/net/gnrc/Makefile

@@ -19,6 +19,9 @@ endif
 ifneq (,$(filter gnrc_ipv6_ext_frag,$(USEMODULE)))
   DIRS += network_layer/ipv6/ext/frag
 endif
+ifneq (,$(filter gnrc_ipv6_ext_opt,$(USEMODULE)))
+  DIRS += network_layer/ipv6/ext/opt
+endif
 ifneq (,$(filter gnrc_ipv6_ext_rh,$(USEMODULE)))
   DIRS += network_layer/ipv6/ext/rh
 endif

sys/net/gnrc/network_layer/ipv6/ext/gnrc_ipv6_ext.c

@@ -24,6 +24,7 @@
 #include "net/gnrc/icmpv6/error.h"
 #include "net/gnrc/ipv6.h"
 #include "net/gnrc/ipv6/ext/frag.h"
+#include "net/gnrc/ipv6/ext/opt.h"
 #include "net/gnrc/ipv6/ext/rh.h"
 #if defined(MODULE_GNRC_SIXLOWPAN_IPHC_NHC) && \
     defined(MODULE_GNRC_IPV6_EXT_FRAG)
@@ -311,6 +312,10 @@ static gnrc_pktsnip_t *_demux(gnrc_pktsnip_t *pkt, unsigned protnum)
 #endif  /* MODULE_GNRC_IPV6_EXT_FRAG */
         case PROTNUM_IPV6_EXT_HOPOPT:
         case PROTNUM_IPV6_EXT_DST:
+            if (IS_USED(MODULE_GNRC_IPV6_EXT_OPT)) {
+                return gnrc_ipv6_ext_opt_process(pkt, protnum);
+            }
+            /* Intentionally falls through */
         case PROTNUM_IPV6_EXT_AH:
         case PROTNUM_IPV6_EXT_ESP:
         case PROTNUM_IPV6_EXT_MOB:

sys/net/gnrc/network_layer/ipv6/ext/opt/Makefile

@@ -0,0 +1,3 @@
+MODULE := gnrc_ipv6_ext_opt
+
+include $(RIOTBASE)/Makefile.base

sys/net/gnrc/network_layer/ipv6/ext/opt/gnrc_ipv6_ext_opt.c

@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2020 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @{
+ *
+ * @file
+ * @author  Martine Lenders <[email protected]>
+ */
+
+#include "net/ipv6.h"
+#include "net/ipv6/ext.h"
+#include "net/ipv6/ext/opt.h"
+#include "net/gnrc/icmpv6/error.h"
+#include "net/gnrc/pktbuf.h"
+
+#include "net/gnrc/ipv6/ext/opt.h"
+
+#define ENABLE_DEBUG    (0)
+#include "debug.h"
+
+/**
+ * @brief   Determine what action to do, when option is not recognized
+ *
+ * @see     https://tools.ietf.org/html/rfc8200#section-4.2
+ *
+ * @param[in] type  Type of the option
+ */
+static inline uint8_t _unrec_action(uint8_t type)
+{
+    return (type & IPV6_EXT_OPT_ACTION_MASK);
+}
+
+static bool _multicast_dst(gnrc_pktsnip_t *pkt)
+{
+    gnrc_pktsnip_t *ipv6 = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_IPV6);
+    ipv6_hdr_t *ipv6_hdr;
+
+    assert(ipv6 != NULL);
+    ipv6_hdr = ipv6->data;
+    return ipv6_addr_is_multicast(&ipv6_hdr->dst);
+}
+
+gnrc_pktsnip_t *gnrc_ipv6_ext_opt_process(gnrc_pktsnip_t *pkt,
+                                          uint8_t protnum)
+{
+    assert(pkt != NULL);
+    assert((protnum == PROTNUM_IPV6_EXT_HOPOPT) ||
+           (protnum == PROTNUM_IPV6_EXT_DST));
+    gnrc_pktsnip_t *hdr;
+    ipv6_ext_t *opt_hdr = pkt->data;
+    uint8_t *opts;
+    size_t hdr_len;
+
+    if (pkt->size < sizeof(ipv6_ext_t)) {
+        DEBUG("gnrc_ipv6_ext_opt: packet of invalid size\n");
+        goto error;
+    }
+    hdr_len = ((opt_hdr->len * IPV6_EXT_LEN_UNIT) + IPV6_EXT_LEN_UNIT);
+    hdr = gnrc_pktbuf_mark(pkt, hdr_len, GNRC_NETTYPE_IPV6_EXT);
+    if (hdr == NULL) {
+        DEBUG("gnrc_ipv6_ext_opt: unable to mark option header\n");
+        goto error;
+    }
+    opts = hdr->data;
+    for (unsigned offset = sizeof(ipv6_ext_t); offset < hdr_len;) {
+        uint8_t opt_type = opts[offset++];
+        uint8_t opt_len;
+
+        if (opt_type == IPV6_EXT_OPT_PAD1) {
+            /* nothing more to do */
+            continue;
+        }
+        opt_len = opts[offset++];
+        if (opt_len > (hdr_len - offset)) {
+            DEBUG("gnrc_ipv6_ext_opt: invalid option size\n");
+            goto error;
+        }
+        switch (opt_type) {
+            /* IPV6_EXT_OPT_PAD1 already handled before length check due
+             * to special format */
+            case IPV6_EXT_OPT_PADN:
+                /* nothing to do, offset will be progressed below */
+                break;
+            default: {
+                bool send_error = false;
+
+                switch (_unrec_action(opt_type)) {
+                    case IPV6_EXT_OPT_ACTION_SKIP:
+                        DEBUG("gnrc_ipv6_ext_opt: skipping unknown "
+                              "option %02x\n", opt_type);
+                        /* skip here already, as we don't reach the
+                         * incrementation of offset below */
+                        offset += opt_len;
+                        continue;
+                    case IPV6_EXT_OPT_ACTION_DISC:
+                        break;
+                    case IPV6_EXT_OPT_ACTION_DISC_ERR_MCAST:
+                        send_error = IS_USED(MODULE_GNRC_ICMPV6_ERROR);
+                        break;
+                    case IPV6_EXT_OPT_ACTION_DISC_ERR:
+                        send_error = IS_USED(MODULE_GNRC_ICMPV6_ERROR) &&
+                                     !_multicast_dst(pkt);
+                        break;
+                }
+                DEBUG("gnrc_ipv6_ext_opt: discarding packet with unknown "
+                      "option %02x\n", opt_type);
+                if (send_error) {
+                    DEBUG("gnrc_ipv6_ext_opt: reporting parameter problem "
+                          "for option %02x (pos at %02x)\n", opts[offset - 2U],
+                          opt_type);
+                    gnrc_icmpv6_error_param_prob_send(
+                            ICMPV6_ERROR_PARAM_PROB_OPT,
+                            /* offset was already progressed to opt data*/
+                            &opts[offset - 2U], pkt);
+                }
+                goto error;
+            }
+        }
+        offset += opt_len;
+    }
+    return pkt;
+error:
+    gnrc_pktbuf_release_error(pkt, EINVAL);
+    return NULL;
+}
+
+/** @} */

tests/gnrc_ipv6_ext_opt/Makefile

@@ -0,0 +1,39 @@
+DEVELHELP = 1
+# name of your application
+include ../Makefile.tests_common
+
+export TAP ?= tap0
+
+# use Ethernet as link-layer protocol
+ifeq (native,$(BOARD))
+  TERMFLAGS ?= $(TAP)
+else
+  ETHOS_BAUDRATE ?= 115200
+  CFLAGS += -DETHOS_BAUDRATE=$(ETHOS_BAUDRATE)
+  TERMDEPS += ethos
+  TERMPROG ?= sudo $(RIOTTOOLS)/ethos/ethos
+  TERMFLAGS ?= $(TAP) $(PORT) $(ETHOS_BAUDRATE)
+endif
+USEMODULE += auto_init_gnrc_netif
+USEMODULE += gnrc_ipv6_default
+USEMODULE += gnrc_icmpv6_error
+USEMODULE += gnrc_pktdump
+USEMODULE += gnrc_pktbuf_cmd
+# IPv6 extension headers
+USEMODULE += gnrc_ipv6_ext_opt
+USEMODULE += od
+# Add also the shell, some shell commands
+USEMODULE += shell
+USEMODULE += shell_commands
+USEMODULE += ps
+
+# The test requires some setup and to be run as root
+# So it cannot currently be run
+TEST_ON_CI_BLACKLIST += all
+
+.PHONY: ethos
+
+ethos:
+	$(Q)env -u CC -u CFLAGS make -C $(RIOTTOOLS)/ethos
+
+include $(RIOTBASE)/Makefile.include

tests/gnrc_ipv6_ext_opt/Makefile.board.dep

@@ -0,0 +1,6 @@
+# Put board specific dependencies here
+ifeq (native,$(BOARD))
+  USEMODULE += netdev_tap
+else
+  USEMODULE += stdio_ethos
+endif