6lowpan: introduce 6lowpan-nd
authorAlexander Aring <aar@pengutronix.de>
Wed, 15 Jun 2016 19:20:25 +0000 (21:20 +0200)
committerDavid S. Miller <davem@davemloft.net>
Thu, 16 Jun 2016 03:41:23 +0000 (20:41 -0700)
This patch introduce different 6lowpan handling for receive and transmit
NS/NA messages for the ipv6 neighbour discovery. The first use-case is
for supporting 802.15.4 short addresses inside the option fields and
handling for RFC6775 6CO option field as userspace option.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/net/ndisc.h
net/6lowpan/6lowpan_i.h
net/6lowpan/Makefile
net/6lowpan/core.c
net/6lowpan/ndisc.c [new file with mode: 0644]

index 3f0f41ddbeb043103b348c522c171862cea9ba52..be1fe2283254449b7e7183ea6b5d4d209cdcf55a 100644 (file)
@@ -35,6 +35,7 @@ enum {
        ND_OPT_ROUTE_INFO = 24,         /* RFC4191 */
        ND_OPT_RDNSS = 25,              /* RFC5006 */
        ND_OPT_DNSSL = 31,              /* RFC6106 */
+       ND_OPT_6CO = 34,                /* RFC6775 */
        __ND_OPT_MAX
 };
 
@@ -109,14 +110,19 @@ struct ndisc_options {
 #endif
        struct nd_opt_hdr *nd_useropts;
        struct nd_opt_hdr *nd_useropts_end;
+#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
+       struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
+#endif
 };
 
-#define nd_opts_src_lladdr     nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
-#define nd_opts_tgt_lladdr     nd_opt_array[ND_OPT_TARGET_LL_ADDR]
-#define nd_opts_pi             nd_opt_array[ND_OPT_PREFIX_INFO]
-#define nd_opts_pi_end         nd_opt_array[__ND_OPT_PREFIX_INFO_END]
-#define nd_opts_rh             nd_opt_array[ND_OPT_REDIRECT_HDR]
-#define nd_opts_mtu            nd_opt_array[ND_OPT_MTU]
+#define nd_opts_src_lladdr             nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
+#define nd_opts_tgt_lladdr             nd_opt_array[ND_OPT_TARGET_LL_ADDR]
+#define nd_opts_pi                     nd_opt_array[ND_OPT_PREFIX_INFO]
+#define nd_opts_pi_end                 nd_opt_array[__ND_OPT_PREFIX_INFO_END]
+#define nd_opts_rh                     nd_opt_array[ND_OPT_REDIRECT_HDR]
+#define nd_opts_mtu                    nd_opt_array[ND_OPT_MTU]
+#define nd_802154_opts_src_lladdr      nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
+#define nd_802154_opts_tgt_lladdr      nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
 
 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 
index 97ecc27aeca695da7de57e66ac741663095886a1..a67caee119290c6b6ebf090ac39fbd6845f3d476 100644 (file)
@@ -12,6 +12,10 @@ static inline bool lowpan_is_ll(const struct net_device *dev,
        return lowpan_dev(dev)->lltype == lltype;
 }
 
+extern const struct ndisc_ops lowpan_ndisc_ops;
+
+int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev);
+
 #ifdef CONFIG_6LOWPAN_DEBUGFS
 int lowpan_dev_debugfs_init(struct net_device *dev);
 void lowpan_dev_debugfs_exit(struct net_device *dev);
index e44f3bf2dd42e23e22cc7acb008e52cb2210f75c..12d131ab2324f1ebf4d5d122341f81333a3c611c 100644 (file)
@@ -1,6 +1,6 @@
 obj-$(CONFIG_6LOWPAN) += 6lowpan.o
 
-6lowpan-y := core.o iphc.o nhc.o
+6lowpan-y := core.o iphc.o nhc.o ndisc.o
 6lowpan-$(CONFIG_6LOWPAN_DEBUGFS) += debugfs.o
 
 #rfc6282 nhcs
index 1c7a42b4852404c79af475bb8240b30d97302793..5945f7e19c679cb882a5a5716a1de33bed50a8f1 100644 (file)
@@ -34,6 +34,8 @@ int lowpan_register_netdevice(struct net_device *dev,
        for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
                lowpan_dev(dev)->ctx.table[i].id = i;
 
+       dev->ndisc_ops = &lowpan_ndisc_ops;
+
        ret = register_netdevice(dev);
        if (ret < 0)
                return ret;
@@ -73,7 +75,7 @@ void lowpan_unregister_netdev(struct net_device *dev)
 }
 EXPORT_SYMBOL(lowpan_unregister_netdev);
 
-static int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
+int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
 {
        struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
 
diff --git a/net/6lowpan/ndisc.c b/net/6lowpan/ndisc.c
new file mode 100644 (file)
index 0000000..ae1d419
--- /dev/null
@@ -0,0 +1,234 @@
+/* This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Authors:
+ * (C) 2016 Pengutronix, Alexander Aring <aar@pengutronix.de>
+ */
+
+#include <net/6lowpan.h>
+#include <net/addrconf.h>
+#include <net/ndisc.h>
+
+#include "6lowpan_i.h"
+
+static int lowpan_ndisc_is_useropt(u8 nd_opt_type)
+{
+       return nd_opt_type == ND_OPT_6CO;
+}
+
+#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
+#define NDISC_802154_SHORT_ADDR_LENGTH 1
+static int lowpan_ndisc_parse_802154_options(const struct net_device *dev,
+                                            struct nd_opt_hdr *nd_opt,
+                                            struct ndisc_options *ndopts)
+{
+       switch (nd_opt->nd_opt_len) {
+       case NDISC_802154_SHORT_ADDR_LENGTH:
+               if (ndopts->nd_802154_opt_array[nd_opt->nd_opt_type])
+                       ND_PRINTK(2, warn,
+                                 "%s: duplicated short addr ND6 option found: type=%d\n",
+                                 __func__, nd_opt->nd_opt_type);
+               else
+                       ndopts->nd_802154_opt_array[nd_opt->nd_opt_type] = nd_opt;
+               return 1;
+       default:
+               /* all others will be handled by ndisc IPv6 option parsing */
+               return 0;
+       }
+}
+
+static int lowpan_ndisc_parse_options(const struct net_device *dev,
+                                     struct nd_opt_hdr *nd_opt,
+                                     struct ndisc_options *ndopts)
+{
+       switch (nd_opt->nd_opt_type) {
+       case ND_OPT_SOURCE_LL_ADDR:
+       case ND_OPT_TARGET_LL_ADDR:
+               return lowpan_ndisc_parse_802154_options(dev, nd_opt, ndopts);
+       default:
+               return 0;
+       }
+}
+
+static void lowpan_ndisc_802154_update(struct neighbour *n, u32 flags,
+                                      u8 icmp6_type,
+                                      const struct ndisc_options *ndopts)
+{
+       struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
+       u8 *lladdr_short = NULL;
+
+       switch (icmp6_type) {
+       case NDISC_ROUTER_SOLICITATION:
+       case NDISC_ROUTER_ADVERTISEMENT:
+       case NDISC_NEIGHBOUR_SOLICITATION:
+               if (ndopts->nd_802154_opts_src_lladdr) {
+                       lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_src_lladdr,
+                                                            IEEE802154_SHORT_ADDR_LEN, 0);
+                       if (!lladdr_short) {
+                               ND_PRINTK(2, warn,
+                                         "NA: invalid short link-layer address length\n");
+                               return;
+                       }
+               }
+               break;
+       case NDISC_REDIRECT:
+       case NDISC_NEIGHBOUR_ADVERTISEMENT:
+               if (ndopts->nd_802154_opts_tgt_lladdr) {
+                       lladdr_short = __ndisc_opt_addr_data(ndopts->nd_802154_opts_tgt_lladdr,
+                                                            IEEE802154_SHORT_ADDR_LEN, 0);
+                       if (!lladdr_short) {
+                               ND_PRINTK(2, warn,
+                                         "NA: invalid short link-layer address length\n");
+                               return;
+                       }
+               }
+               break;
+       default:
+               break;
+       }
+
+       write_lock_bh(&n->lock);
+       if (lladdr_short)
+               ieee802154_be16_to_le16(&neigh->short_addr, lladdr_short);
+       else
+               neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+       write_unlock_bh(&n->lock);
+}
+
+static void lowpan_ndisc_update(const struct net_device *dev,
+                               struct neighbour *n, u32 flags, u8 icmp6_type,
+                               const struct ndisc_options *ndopts)
+{
+       if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
+               return;
+
+       /* react on overrides only. TODO check if this is really right. */
+       if (flags & NEIGH_UPDATE_F_OVERRIDE)
+               lowpan_ndisc_802154_update(n, flags, icmp6_type, ndopts);
+}
+
+static int lowpan_ndisc_opt_addr_space(const struct net_device *dev,
+                                      u8 icmp6_type, struct neighbour *neigh,
+                                      u8 *ha_buf, u8 **ha)
+{
+       struct lowpan_802154_neigh *n;
+       struct wpan_dev *wpan_dev;
+       int addr_space = 0;
+
+       if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
+               return 0;
+
+       switch (icmp6_type) {
+       case NDISC_REDIRECT:
+               n = lowpan_802154_neigh(neighbour_priv(neigh));
+
+               read_lock_bh(&neigh->lock);
+               if (lowpan_802154_is_valid_src_short_addr(n->short_addr)) {
+                       memcpy(ha_buf, &n->short_addr,
+                              IEEE802154_SHORT_ADDR_LEN);
+                       read_unlock_bh(&neigh->lock);
+                       addr_space += __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
+                       *ha = ha_buf;
+               }
+               read_unlock_bh(&neigh->lock);
+               break;
+       case NDISC_NEIGHBOUR_ADVERTISEMENT:
+       case NDISC_NEIGHBOUR_SOLICITATION:
+       case NDISC_ROUTER_SOLICITATION:
+               wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
+
+               if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
+                       addr_space = __ndisc_opt_addr_space(IEEE802154_SHORT_ADDR_LEN, 0);
+               break;
+       default:
+               break;
+       }
+
+       return addr_space;
+}
+
+static void lowpan_ndisc_fill_addr_option(const struct net_device *dev,
+                                         struct sk_buff *skb, u8 icmp6_type,
+                                         const u8 *ha)
+{
+       struct wpan_dev *wpan_dev;
+       __be16 short_addr;
+       u8 opt_type;
+
+       if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
+               return;
+
+       switch (icmp6_type) {
+       case NDISC_REDIRECT:
+               if (ha) {
+                       ieee802154_le16_to_be16(&short_addr, ha);
+                       __ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
+                                                &short_addr,
+                                                IEEE802154_SHORT_ADDR_LEN, 0);
+               }
+               return;
+       case NDISC_NEIGHBOUR_ADVERTISEMENT:
+               opt_type = ND_OPT_TARGET_LL_ADDR;
+               break;
+       case NDISC_ROUTER_SOLICITATION:
+       case NDISC_NEIGHBOUR_SOLICITATION:
+               opt_type = ND_OPT_SOURCE_LL_ADDR;
+               break;
+       default:
+               return;
+       }
+
+       wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
+
+       if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
+               ieee802154_le16_to_be16(&short_addr,
+                                       &wpan_dev->short_addr);
+               __ndisc_fill_addr_option(skb, opt_type, &short_addr,
+                                        IEEE802154_SHORT_ADDR_LEN, 0);
+       }
+}
+
+static void lowpan_ndisc_prefix_rcv_add_addr(struct net *net,
+                                            struct net_device *dev,
+                                            const struct prefix_info *pinfo,
+                                            struct inet6_dev *in6_dev,
+                                            struct in6_addr *addr,
+                                            int addr_type, u32 addr_flags,
+                                            bool sllao, bool tokenized,
+                                            __u32 valid_lft,
+                                            u32 prefered_lft,
+                                            bool dev_addr_generated)
+{
+       int err;
+
+       /* generates short based address for RA PIO's */
+       if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) && dev_addr_generated &&
+           !addrconf_ifid_802154_6lowpan(addr->s6_addr + 8, dev)) {
+               err = addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
+                                                  addr, addr_type, addr_flags,
+                                                  sllao, tokenized, valid_lft,
+                                                  prefered_lft);
+               if (err)
+                       ND_PRINTK(2, warn,
+                                 "RA: could not add a short address based address for prefix: %pI6c\n",
+                                 &pinfo->prefix);
+       }
+}
+#endif
+
+const struct ndisc_ops lowpan_ndisc_ops = {
+       .is_useropt             = lowpan_ndisc_is_useropt,
+#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
+       .parse_options          = lowpan_ndisc_parse_options,
+       .update                 = lowpan_ndisc_update,
+       .opt_addr_space         = lowpan_ndisc_opt_addr_space,
+       .fill_addr_option       = lowpan_ndisc_fill_addr_option,
+       .prefix_rcv_add_addr    = lowpan_ndisc_prefix_rcv_add_addr,
+#endif
+};