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Diffstat (limited to 'net/ieee802154/6lowpan.c')
-rw-r--r--net/ieee802154/6lowpan.c891
1 files changed, 891 insertions, 0 deletions
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
new file mode 100644
index 00000000000..19d6aefe97d
--- /dev/null
+++ b/net/ieee802154/6lowpan.c
@@ -0,0 +1,891 @@
+/*
+ * Copyright 2011, Siemens AG
+ * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+/*
+ * Based on patches from Jon Smirl <jonsmirl@gmail.com>
+ * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* Jon's code is based on 6lowpan implementation for Contiki which is:
+ * Copyright (c) 2008, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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.
+ */
+
+#define DEBUG
+
+#include <linux/bitops.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/netdevice.h>
+#include <net/af_ieee802154.h>
+#include <net/ieee802154.h>
+#include <net/ieee802154_netdev.h>
+#include <net/ipv6.h>
+
+#include "6lowpan.h"
+
+/* TTL uncompression values */
+static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
+
+static LIST_HEAD(lowpan_devices);
+
+/*
+ * Uncompression of linklocal:
+ * 0 -> 16 bytes from packet
+ * 1 -> 2 bytes from prefix - bunch of zeroes and 8 from packet
+ * 2 -> 2 bytes from prefix - zeroes + 2 from packet
+ * 3 -> 2 bytes from prefix - infer 8 bytes from lladdr
+ *
+ * NOTE: => the uncompress function does change 0xf to 0x10
+ * NOTE: 0x00 => no-autoconfig => unspecified
+ */
+static const u8 lowpan_unc_llconf[] = {0x0f, 0x28, 0x22, 0x20};
+
+/*
+ * Uncompression of ctx-based:
+ * 0 -> 0 bits from packet [unspecified / reserved]
+ * 1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet
+ * 2 -> 8 bytes from prefix - zeroes + 2 from packet
+ * 3 -> 8 bytes from prefix - infer 8 bytes from lladdr
+ */
+static const u8 lowpan_unc_ctxconf[] = {0x00, 0x88, 0x82, 0x80};
+
+/*
+ * Uncompression of ctx-base
+ * 0 -> 0 bits from packet
+ * 1 -> 2 bytes from prefix - bunch of zeroes 5 from packet
+ * 2 -> 2 bytes from prefix - zeroes + 3 from packet
+ * 3 -> 2 bytes from prefix - infer 1 bytes from lladdr
+ */
+static const u8 lowpan_unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21};
+
+/* Link local prefix */
+static const u8 lowpan_llprefix[] = {0xfe, 0x80};
+
+/* private device info */
+struct lowpan_dev_info {
+ struct net_device *real_dev; /* real WPAN device ptr */
+ struct mutex dev_list_mtx; /* mutex for list ops */
+};
+
+struct lowpan_dev_record {
+ struct net_device *ldev;
+ struct list_head list;
+};
+
+static inline struct
+lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
+{
+ return netdev_priv(dev);
+}
+
+static inline void lowpan_address_flip(u8 *src, u8 *dest)
+{
+ int i;
+ for (i = 0; i < IEEE802154_ADDR_LEN; i++)
+ (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
+}
+
+/* list of all 6lowpan devices, uses for package delivering */
+/* print data in line */
+static inline void lowpan_raw_dump_inline(const char *caller, char *msg,
+ unsigned char *buf, int len)
+{
+#ifdef DEBUG
+ if (msg)
+ pr_debug("(%s) %s: ", caller, msg);
+ print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE,
+ 16, 1, buf, len, false);
+#endif /* DEBUG */
+}
+
+/*
+ * print data in a table format:
+ *
+ * addr: xx xx xx xx xx xx
+ * addr: xx xx xx xx xx xx
+ * ...
+ */
+static inline void lowpan_raw_dump_table(const char *caller, char *msg,
+ unsigned char *buf, int len)
+{
+#ifdef DEBUG
+ if (msg)
+ pr_debug("(%s) %s:\n", caller, msg);
+ print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET,
+ 16, 1, buf, len, false);
+#endif /* DEBUG */
+}
+
+static u8
+lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, const struct in6_addr *ipaddr,
+ const unsigned char *lladdr)
+{
+ u8 val = 0;
+
+ if (is_addr_mac_addr_based(ipaddr, lladdr))
+ val = 3; /* 0-bits */
+ else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
+ /* compress IID to 16 bits xxxx::XXXX */
+ memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
+ *hc06_ptr += 2;
+ val = 2; /* 16-bits */
+ } else {
+ /* do not compress IID => xxxx::IID */
+ memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
+ *hc06_ptr += 8;
+ val = 1; /* 64-bits */
+ }
+
+ return rol8(val, shift);
+}
+
+static void
+lowpan_uip_ds6_set_addr_iid(struct in6_addr *ipaddr, unsigned char *lladdr)
+{
+ memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ALEN);
+ /* second bit-flip (Universe/Local) is done according RFC2464 */
+ ipaddr->s6_addr[8] ^= 0x02;
+}
+
+/*
+ * Uncompress addresses based on a prefix and a postfix with zeroes in
+ * between. If the postfix is zero in length it will use the link address
+ * to configure the IP address (autoconf style).
+ * pref_post_count takes a byte where the first nibble specify prefix count
+ * and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
+ */
+static int
+lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
+ u8 const *prefix, u8 pref_post_count, unsigned char *lladdr)
+{
+ u8 prefcount = pref_post_count >> 4;
+ u8 postcount = pref_post_count & 0x0f;
+
+ /* full nibble 15 => 16 */
+ prefcount = (prefcount == 15 ? 16 : prefcount);
+ postcount = (postcount == 15 ? 16 : postcount);
+
+ if (lladdr)
+ lowpan_raw_dump_inline(__func__, "linklocal address",
+ lladdr, IEEE802154_ALEN);
+ if (prefcount > 0)
+ memcpy(ipaddr, prefix, prefcount);
+
+ if (prefcount + postcount < 16)
+ memset(&ipaddr->s6_addr[prefcount], 0,
+ 16 - (prefcount + postcount));
+
+ if (postcount > 0) {
+ memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount);
+ skb_pull(skb, postcount);
+ } else if (prefcount > 0) {
+ if (lladdr == NULL)
+ return -EINVAL;
+
+ /* no IID based configuration if no prefix and no data */
+ lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr);
+ }
+
+ pr_debug("(%s): uncompressing %d + %d => ", __func__, prefcount,
+ postcount);
+ lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16);
+
+ return 0;
+}
+
+static u8 lowpan_fetch_skb_u8(struct sk_buff *skb)
+{
+ u8 ret;
+
+ ret = skb->data[0];
+ skb_pull(skb, 1);
+
+ return ret;
+}
+
+static int lowpan_header_create(struct sk_buff *skb,
+ struct net_device *dev,
+ unsigned short type, const void *_daddr,
+ const void *_saddr, unsigned len)
+{
+ u8 tmp, iphc0, iphc1, *hc06_ptr;
+ struct ipv6hdr *hdr;
+ const u8 *saddr = _saddr;
+ const u8 *daddr = _daddr;
+ u8 *head;
+ struct ieee802154_addr sa, da;
+
+ if (type != ETH_P_IPV6)
+ return 0;
+ /* TODO:
+ * if this package isn't ipv6 one, where should it be routed?
+ */
+ head = kzalloc(100, GFP_KERNEL);
+ if (head == NULL)
+ return -ENOMEM;
+
+ hdr = ipv6_hdr(skb);
+ hc06_ptr = head + 2;
+
+ pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
+ "\tnexthdr = 0x%02x\n\thop_lim = %d\n", __func__,
+ hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
+ hdr->hop_limit);
+
+ lowpan_raw_dump_table(__func__, "raw skb network header dump",
+ skb_network_header(skb), sizeof(struct ipv6hdr));
+
+ if (!saddr)
+ saddr = dev->dev_addr;
+
+ lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
+
+ /*
+ * As we copy some bit-length fields, in the IPHC encoding bytes,
+ * we sometimes use |=
+ * If the field is 0, and the current bit value in memory is 1,
+ * this does not work. We therefore reset the IPHC encoding here
+ */
+ iphc0 = LOWPAN_DISPATCH_IPHC;
+ iphc1 = 0;
+
+ /* TODO: context lookup */
+
+ lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
+
+ /*
+ * Traffic class, flow label
+ * If flow label is 0, compress it. If traffic class is 0, compress it
+ * We have to process both in the same time as the offset of traffic
+ * class depends on the presence of version and flow label
+ */
+
+ /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
+ tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
+ tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
+
+ if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
+ (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
+ /* flow label can be compressed */
+ iphc0 |= LOWPAN_IPHC_FL_C;
+ if ((hdr->priority == 0) &&
+ ((hdr->flow_lbl[0] & 0xF0) == 0)) {
+ /* compress (elide) all */
+ iphc0 |= LOWPAN_IPHC_TC_C;
+ } else {
+ /* compress only the flow label */
+ *hc06_ptr = tmp;
+ hc06_ptr += 1;
+ }
+ } else {
+ /* Flow label cannot be compressed */
+ if ((hdr->priority == 0) &&
+ ((hdr->flow_lbl[0] & 0xF0) == 0)) {
+ /* compress only traffic class */
+ iphc0 |= LOWPAN_IPHC_TC_C;
+ *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
+ memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
+ hc06_ptr += 3;
+ } else {
+ /* compress nothing */
+ memcpy(hc06_ptr, &hdr, 4);
+ /* replace the top byte with new ECN | DSCP format */
+ *hc06_ptr = tmp;
+ hc06_ptr += 4;
+ }
+ }
+
+ /* NOTE: payload length is always compressed */
+
+ /* Next Header is compress if UDP */
+ if (hdr->nexthdr == UIP_PROTO_UDP)
+ iphc0 |= LOWPAN_IPHC_NH_C;
+
+/* TODO: next header compression */
+
+ if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
+ *hc06_ptr = hdr->nexthdr;
+ hc06_ptr += 1;
+ }
+
+ /*
+ * Hop limit
+ * if 1: compress, encoding is 01
+ * if 64: compress, encoding is 10
+ * if 255: compress, encoding is 11
+ * else do not compress
+ */
+ switch (hdr->hop_limit) {
+ case 1:
+ iphc0 |= LOWPAN_IPHC_TTL_1;
+ break;
+ case 64:
+ iphc0 |= LOWPAN_IPHC_TTL_64;
+ break;
+ case 255:
+ iphc0 |= LOWPAN_IPHC_TTL_255;
+ break;
+ default:
+ *hc06_ptr = hdr->hop_limit;
+ break;
+ }
+
+ /* source address compression */
+ if (is_addr_unspecified(&hdr->saddr)) {
+ pr_debug("(%s): source address is unspecified, setting SAC\n",
+ __func__);
+ iphc1 |= LOWPAN_IPHC_SAC;
+ /* TODO: context lookup */
+ } else if (is_addr_link_local(&hdr->saddr)) {
+ pr_debug("(%s): source address is link-local\n", __func__);
+ iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
+ LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
+ } else {
+ pr_debug("(%s): send the full source address\n", __func__);
+ memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
+ hc06_ptr += 16;
+ }
+
+ /* destination address compression */
+ if (is_addr_mcast(&hdr->daddr)) {
+ pr_debug("(%s): destination address is multicast", __func__);
+ iphc1 |= LOWPAN_IPHC_M;
+ if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
+ pr_debug("compressed to 1 octet\n");
+ iphc1 |= LOWPAN_IPHC_DAM_11;
+ /* use last byte */
+ *hc06_ptr = hdr->daddr.s6_addr[15];
+ hc06_ptr += 1;
+ } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
+ pr_debug("compressed to 4 octets\n");
+ iphc1 |= LOWPAN_IPHC_DAM_10;
+ /* second byte + the last three */
+ *hc06_ptr = hdr->daddr.s6_addr[1];
+ memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
+ hc06_ptr += 4;
+ } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
+ pr_debug("compressed to 6 octets\n");
+ iphc1 |= LOWPAN_IPHC_DAM_01;
+ /* second byte + the last five */
+ *hc06_ptr = hdr->daddr.s6_addr[1];
+ memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
+ hc06_ptr += 6;
+ } else {
+ pr_debug("using full address\n");
+ iphc1 |= LOWPAN_IPHC_DAM_00;
+ memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
+ hc06_ptr += 16;
+ }
+ } else {
+ pr_debug("(%s): destination address is unicast: ", __func__);
+ /* TODO: context lookup */
+ if (is_addr_link_local(&hdr->daddr)) {
+ pr_debug("destination address is link-local\n");
+ iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
+ LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
+ } else {
+ pr_debug("using full address\n");
+ memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
+ hc06_ptr += 16;
+ }
+ }
+
+ /* TODO: UDP header compression */
+ /* TODO: Next Header compression */
+
+ head[0] = iphc0;
+ head[1] = iphc1;
+
+ skb_pull(skb, sizeof(struct ipv6hdr));
+ memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
+
+ kfree(head);
+
+ lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
+ skb->len);
+
+ /*
+ * NOTE1: I'm still unsure about the fact that compression and WPAN
+ * header are created here and not later in the xmit. So wait for
+ * an opinion of net maintainers.
+ */
+ /*
+ * NOTE2: to be absolutely correct, we must derive PANid information
+ * from MAC subif of the 'dev' and 'real_dev' network devices, but
+ * this isn't implemented in mainline yet, so currently we assign 0xff
+ */
+ {
+ /* prepare wpan address data */
+ sa.addr_type = IEEE802154_ADDR_LONG;
+ sa.pan_id = 0xff;
+
+ da.addr_type = IEEE802154_ADDR_LONG;
+ da.pan_id = 0xff;
+
+ memcpy(&(da.hwaddr), daddr, 8);
+ memcpy(&(sa.hwaddr), saddr, 8);
+
+ mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+ return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
+ type, (void *)&da, (void *)&sa, skb->len);
+ }
+}
+
+static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
+{
+ struct sk_buff *new;
+ struct lowpan_dev_record *entry;
+ int stat = NET_RX_SUCCESS;
+
+ new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
+ GFP_ATOMIC);
+ kfree_skb(skb);
+
+ if (!new)
+ return -ENOMEM;
+
+ skb_push(new, sizeof(struct ipv6hdr));
+ skb_reset_network_header(new);
+ skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
+
+ new->protocol = htons(ETH_P_IPV6);
+ new->pkt_type = PACKET_HOST;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(entry, &lowpan_devices, list)
+ if (lowpan_dev_info(entry->ldev)->real_dev == new->dev) {
+ skb = skb_copy(new, GFP_ATOMIC);
+ if (!skb) {
+ stat = -ENOMEM;
+ break;
+ }
+
+ skb->dev = entry->ldev;
+ stat = netif_rx(skb);
+ }
+ rcu_read_unlock();
+
+ kfree_skb(new);
+
+ return stat;
+}
+
+static int
+lowpan_process_data(struct sk_buff *skb)
+{
+ struct ipv6hdr hdr;
+ u8 tmp, iphc0, iphc1, num_context = 0;
+ u8 *_saddr, *_daddr;
+ int err;
+
+ lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
+ skb->len);
+ /* at least two bytes will be used for the encoding */
+ if (skb->len < 2)
+ goto drop;
+ iphc0 = lowpan_fetch_skb_u8(skb);
+ iphc1 = lowpan_fetch_skb_u8(skb);
+
+ _saddr = mac_cb(skb)->sa.hwaddr;
+ _daddr = mac_cb(skb)->da.hwaddr;
+
+ pr_debug("(%s): iphc0 = %02x, iphc1 = %02x\n", __func__, iphc0, iphc1);
+
+ /* another if the CID flag is set */
+ if (iphc1 & LOWPAN_IPHC_CID) {
+ pr_debug("(%s): CID flag is set, increase header with one\n",
+ __func__);
+ if (!skb->len)
+ goto drop;
+ num_context = lowpan_fetch_skb_u8(skb);
+ }
+
+ hdr.version = 6;
+
+ /* Traffic Class and Flow Label */
+ switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
+ /*
+ * Traffic Class and FLow Label carried in-line
+ * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
+ */
+ case 0: /* 00b */
+ if (!skb->len)
+ goto drop;
+ tmp = lowpan_fetch_skb_u8(skb);
+ memcpy(&hdr.flow_lbl, &skb->data[0], 3);
+ skb_pull(skb, 3);
+ hdr.priority = ((tmp >> 2) & 0x0f);
+ hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
+ (hdr.flow_lbl[0] & 0x0f);
+ break;
+ /*
+ * Traffic class carried in-line
+ * ECN + DSCP (1 byte), Flow Label is elided
+ */
+ case 1: /* 10b */
+ if (!skb->len)
+ goto drop;
+ tmp = lowpan_fetch_skb_u8(skb);
+ hdr.priority = ((tmp >> 2) & 0x0f);
+ hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
+ hdr.flow_lbl[1] = 0;
+ hdr.flow_lbl[2] = 0;
+ break;
+ /*
+ * Flow Label carried in-line
+ * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
+ */
+ case 2: /* 01b */
+ if (!skb->len)
+ goto drop;
+ tmp = lowpan_fetch_skb_u8(skb);
+ hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
+ memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
+ skb_pull(skb, 2);
+ break;
+ /* Traffic Class and Flow Label are elided */
+ case 3: /* 11b */
+ hdr.priority = 0;
+ hdr.flow_lbl[0] = 0;
+ hdr.flow_lbl[1] = 0;
+ hdr.flow_lbl[2] = 0;
+ break;
+ default:
+ break;
+ }
+
+ /* Next Header */
+ if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
+ /* Next header is carried inline */
+ if (!skb->len)
+ goto drop;
+ hdr.nexthdr = lowpan_fetch_skb_u8(skb);
+ pr_debug("(%s): NH flag is set, next header is carried "
+ "inline: %02x\n", __func__, hdr.nexthdr);
+ }
+
+ /* Hop Limit */
+ if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
+ hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
+ else {
+ if (!skb->len)
+ goto drop;
+ hdr.hop_limit = lowpan_fetch_skb_u8(skb);
+ }
+
+ /* Extract SAM to the tmp variable */
+ tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
+
+ /* Source address uncompression */
+ pr_debug("(%s): source address stateless compression\n", __func__);
+ err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
+ lowpan_unc_llconf[tmp], skb->data);
+ if (err)
+ goto drop;
+
+ /* Extract DAM to the tmp variable */
+ tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
+
+ /* check for Multicast Compression */
+ if (iphc1 & LOWPAN_IPHC_M) {
+ if (iphc1 & LOWPAN_IPHC_DAC) {
+ pr_debug("(%s): destination address context-based "
+ "multicast compression\n", __func__);
+ /* TODO: implement this */
+ } else {
+ u8 prefix[] = {0xff, 0x02};
+
+ pr_debug("(%s): destination address non-context-based"
+ " multicast compression\n", __func__);
+ if (0 < tmp && tmp < 3) {
+ if (!skb->len)
+ goto drop;
+ else
+ prefix[1] = lowpan_fetch_skb_u8(skb);
+ }
+
+ err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
+ lowpan_unc_mxconf[tmp], NULL);
+ if (err)
+ goto drop;
+ }
+ } else {
+ pr_debug("(%s): destination address stateless compression\n",
+ __func__);
+ err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
+ lowpan_unc_llconf[tmp], skb->data);
+ if (err)
+ goto drop;
+ }
+
+ /* TODO: UDP header parse */
+
+ /* Not fragmented package */
+ hdr.payload_len = htons(skb->len);
+
+ pr_debug("(%s): skb headroom size = %d, data length = %d\n", __func__,
+ skb_headroom(skb), skb->len);
+
+ pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
+ "nexthdr = 0x%02x\n\thop_lim = %d\n", __func__, hdr.version,
+ ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
+
+ lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
+ sizeof(hdr));
+ return lowpan_skb_deliver(skb, &hdr);
+drop:
+ kfree_skb(skb);
+ return -EINVAL;
+}
+
+static int lowpan_set_address(struct net_device *dev, void *p)
+{
+ struct sockaddr *sa = p;
+
+ if (netif_running(dev))
+ return -EBUSY;
+
+ /* TODO: validate addr */
+ memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
+
+ return 0;
+}
+
+static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ int err = 0;
+
+ pr_debug("(%s): package xmit\n", __func__);
+
+ skb->dev = lowpan_dev_info(dev)->real_dev;
+ if (skb->dev == NULL) {
+ pr_debug("(%s) ERROR: no real wpan device found\n", __func__);
+ dev_kfree_skb(skb);
+ } else
+ err = dev_queue_xmit(skb);
+
+ return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
+}
+
+static void lowpan_dev_free(struct net_device *dev)
+{
+ dev_put(lowpan_dev_info(dev)->real_dev);
+ free_netdev(dev);
+}
+
+static struct header_ops lowpan_header_ops = {
+ .create = lowpan_header_create,
+};
+
+static const struct net_device_ops lowpan_netdev_ops = {
+ .ndo_start_xmit = lowpan_xmit,
+ .ndo_set_mac_address = lowpan_set_address,
+};
+
+static void lowpan_setup(struct net_device *dev)
+{
+ pr_debug("(%s)\n", __func__);
+
+ dev->addr_len = IEEE802154_ADDR_LEN;
+ memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
+ dev->type = ARPHRD_IEEE802154;
+ dev->features = NETIF_F_NO_CSUM;
+ /* Frame Control + Sequence Number + Address fields + Security Header */
+ dev->hard_header_len = 2 + 1 + 20 + 14;
+ dev->needed_tailroom = 2; /* FCS */
+ dev->mtu = 1281;
+ dev->tx_queue_len = 0;
+ dev->flags = IFF_NOARP | IFF_BROADCAST;
+ dev->watchdog_timeo = 0;
+
+ dev->netdev_ops = &lowpan_netdev_ops;
+ dev->header_ops = &lowpan_header_ops;
+ dev->destructor = lowpan_dev_free;
+}
+
+static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+ pr_debug("(%s)\n", __func__);
+
+ if (tb[IFLA_ADDRESS]) {
+ if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ if (!netif_running(dev))
+ goto drop;
+
+ if (dev->type != ARPHRD_IEEE802154)
+ goto drop;
+
+ /* check that it's our buffer */
+ if ((skb->data[0] & 0xe0) == 0x60)
+ lowpan_process_data(skb);
+
+ return NET_RX_SUCCESS;
+
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
+static int lowpan_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[])
+{
+ struct net_device *real_dev;
+ struct lowpan_dev_record *entry;
+
+ pr_debug("(%s)\n", __func__);
+
+ if (!tb[IFLA_LINK])
+ return -EINVAL;
+ /* find and hold real wpan device */
+ real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+ if (!real_dev)
+ return -ENODEV;
+
+ lowpan_dev_info(dev)->real_dev = real_dev;
+ mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
+
+ entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
+ if (!entry) {
+ dev_put(real_dev);
+ lowpan_dev_info(dev)->real_dev = NULL;
+ return -ENOMEM;
+ }
+
+ entry->ldev = dev;
+
+ mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
+ INIT_LIST_HEAD(&entry->list);
+ list_add_tail(&entry->list, &lowpan_devices);
+ mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
+
+ register_netdevice(dev);
+
+ return 0;
+}
+
+static void lowpan_dellink(struct net_device *dev, struct list_head *head)
+{
+ struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
+ struct net_device *real_dev = lowpan_dev->real_dev;
+ struct lowpan_dev_record *entry;
+ struct lowpan_dev_record *tmp;
+
+ ASSERT_RTNL();
+
+ mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
+ list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
+ if (entry->ldev == dev) {
+ list_del(&entry->list);
+ kfree(entry);
+ }
+ }
+ mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
+
+ mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
+
+ unregister_netdevice_queue(dev, head);
+
+ dev_put(real_dev);
+}
+
+static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
+ .kind = "lowpan",
+ .priv_size = sizeof(struct lowpan_dev_info),
+ .setup = lowpan_setup,
+ .newlink = lowpan_newlink,
+ .dellink = lowpan_dellink,
+ .validate = lowpan_validate,
+};
+
+static inline int __init lowpan_netlink_init(void)
+{
+ return rtnl_link_register(&lowpan_link_ops);
+}
+
+static inline void __init lowpan_netlink_fini(void)
+{
+ rtnl_link_unregister(&lowpan_link_ops);
+}
+
+static struct packet_type lowpan_packet_type = {
+ .type = __constant_htons(ETH_P_IEEE802154),
+ .func = lowpan_rcv,
+};
+
+static int __init lowpan_init_module(void)
+{
+ int err = 0;
+
+ pr_debug("(%s)\n", __func__);
+
+ err = lowpan_netlink_init();
+ if (err < 0)
+ goto out;
+
+ dev_add_pack(&lowpan_packet_type);
+out:
+ return err;
+}
+
+static void __exit lowpan_cleanup_module(void)
+{
+ pr_debug("(%s)\n", __func__);
+
+ lowpan_netlink_fini();
+
+ dev_remove_pack(&lowpan_packet_type);
+}
+
+module_init(lowpan_init_module);
+module_exit(lowpan_cleanup_module);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("lowpan");
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-18 12:08:07 +0000