1 /* This program is free software; you can redistribute it and/or modify
2 * it under the terms of the GNU General Public License version 2
3 * as published by the Free Software Foundation.
5 * This program is distributed in the hope that it will be useful,
6 * but WITHOUT ANY WARRANTY; without even the implied warranty of
7 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
8 * GNU General Public License for more details.
11 #include <net/6lowpan.h>
12 #include <net/ndisc.h>
13 #include <net/ieee802154_netdev.h>
14 #include <net/mac802154.h>
16 #include "6lowpan_i.h"
18 #define LOWPAN_FRAG1_HEAD_SIZE 0x4
19 #define LOWPAN_FRAGN_HEAD_SIZE 0x5
21 struct lowpan_addr_info {
22 struct ieee802154_addr daddr;
23 struct ieee802154_addr saddr;
27 lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
29 WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
30 return (struct lowpan_addr_info *)(skb->data -
31 sizeof(struct lowpan_addr_info));
34 /* This callback will be called from AF_PACKET and IPv6 stack, the AF_PACKET
35 * sockets gives an 8 byte array for addresses only!
37 * TODO I think AF_PACKET DGRAM (sending/receiving) RAW (sending) makes no
38 * sense here. We should disable it, the right use-case would be AF_INET6
41 int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev,
42 unsigned short type, const void *daddr,
43 const void *saddr, unsigned int len)
45 struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
46 struct lowpan_addr_info *info = lowpan_skb_priv(skb);
47 struct lowpan_802154_neigh *llneigh = NULL;
48 const struct ipv6hdr *hdr = ipv6_hdr(skb);
55 * if this package isn't ipv6 one, where should it be routed?
57 if (type != ETH_P_IPV6)
60 /* intra-pan communication */
61 info->saddr.pan_id = wpan_dev->pan_id;
62 info->daddr.pan_id = info->saddr.pan_id;
64 if (!memcmp(daddr, ldev->broadcast, EUI64_ADDR_LEN)) {
65 info->daddr.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
66 info->daddr.mode = IEEE802154_ADDR_SHORT;
68 __le16 short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
70 n = neigh_lookup(&nd_tbl, &hdr->daddr, ldev);
72 llneigh = lowpan_802154_neigh(neighbour_priv(n));
73 read_lock_bh(&n->lock);
74 short_addr = llneigh->short_addr;
75 read_unlock_bh(&n->lock);
79 lowpan_802154_is_valid_src_short_addr(short_addr)) {
80 info->daddr.short_addr = short_addr;
81 info->daddr.mode = IEEE802154_ADDR_SHORT;
83 info->daddr.mode = IEEE802154_ADDR_LONG;
84 ieee802154_be64_to_le64(&info->daddr.extended_addr,
93 if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
94 info->saddr.mode = IEEE802154_ADDR_SHORT;
95 info->saddr.short_addr = wpan_dev->short_addr;
97 info->saddr.mode = IEEE802154_ADDR_LONG;
98 info->saddr.extended_addr = wpan_dev->extended_addr;
101 info->saddr.mode = IEEE802154_ADDR_LONG;
102 ieee802154_be64_to_le64(&info->saddr.extended_addr, saddr);
108 static struct sk_buff*
109 lowpan_alloc_frag(struct sk_buff *skb, int size,
110 const struct ieee802154_hdr *master_hdr, bool frag1)
112 struct net_device *wdev = lowpan_802154_dev(skb->dev)->wdev;
113 struct sk_buff *frag;
116 frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size,
121 frag->priority = skb->priority;
122 skb_reserve(frag, wdev->needed_headroom);
123 skb_reset_network_header(frag);
124 *mac_cb(frag) = *mac_cb(skb);
127 memcpy(skb_put(frag, skb->mac_len),
128 skb_mac_header(skb), skb->mac_len);
130 rc = wpan_dev_hard_header(frag, wdev,
132 &master_hdr->source, size);
139 frag = ERR_PTR(-ENOMEM);
146 lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
147 u8 *frag_hdr, int frag_hdrlen,
148 int offset, int len, bool frag1)
150 struct sk_buff *frag;
152 raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
154 frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1);
156 return PTR_ERR(frag);
158 memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen);
159 memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len);
161 raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
163 return dev_queue_xmit(frag);
167 lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
168 const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
173 int frag_cap, frag_len, payload_cap, rc;
174 int skb_unprocessed, skb_offset;
176 frag_tag = htons(lowpan_802154_dev(ldev)->fragment_tag);
177 lowpan_802154_dev(ldev)->fragment_tag++;
179 frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07);
180 frag_hdr[1] = dgram_size & 0xff;
181 memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
183 payload_cap = ieee802154_max_payload(wpan_hdr);
185 frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
186 skb_network_header_len(skb), 8);
188 skb_offset = skb_network_header_len(skb);
189 skb_unprocessed = skb->len - skb->mac_len - skb_offset;
191 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
192 LOWPAN_FRAG1_HEAD_SIZE, 0,
193 frag_len + skb_network_header_len(skb),
196 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
197 __func__, ntohs(frag_tag));
201 frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
202 frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN;
203 frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
206 dgram_offset += frag_len;
207 skb_offset += frag_len;
208 skb_unprocessed -= frag_len;
209 frag_len = min(frag_cap, skb_unprocessed);
211 frag_hdr[4] = dgram_offset >> 3;
213 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
214 LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
217 pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
218 __func__, ntohs(frag_tag), skb_offset);
221 } while (skb_unprocessed > frag_cap);
223 ldev->stats.tx_packets++;
224 ldev->stats.tx_bytes += dgram_size;
226 return NET_XMIT_SUCCESS;
233 static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
234 u16 *dgram_size, u16 *dgram_offset)
236 struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
237 struct ieee802154_mac_cb *cb = mac_cb_init(skb);
238 struct lowpan_addr_info info;
240 memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
242 *dgram_size = skb->len;
243 lowpan_header_compress(skb, ldev, &info.daddr, &info.saddr);
244 /* dgram_offset = (saved bytes after compression) + lowpan header len */
245 *dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb);
247 cb->type = IEEE802154_FC_TYPE_DATA;
249 if (info.daddr.mode == IEEE802154_ADDR_SHORT &&
250 ieee802154_is_broadcast_short_addr(info.daddr.short_addr))
253 cb->ackreq = wpan_dev->ackreq;
255 return wpan_dev_hard_header(skb, lowpan_802154_dev(ldev)->wdev,
256 &info.daddr, &info.saddr, 0);
259 netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
261 struct ieee802154_hdr wpan_hdr;
263 u16 dgram_size, dgram_offset;
265 pr_debug("package xmit\n");
267 WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);
269 /* We must take a copy of the skb before we modify/replace the ipv6
270 * header as the header could be used elsewhere
272 if (unlikely(skb_headroom(skb) < ldev->needed_headroom ||
273 skb_tailroom(skb) < ldev->needed_tailroom)) {
274 struct sk_buff *nskb;
276 nskb = skb_copy_expand(skb, ldev->needed_headroom,
277 ldev->needed_tailroom, GFP_ATOMIC);
283 return NET_XMIT_DROP;
286 skb = skb_unshare(skb, GFP_ATOMIC);
288 return NET_XMIT_DROP;
291 ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
294 return NET_XMIT_DROP;
297 if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
299 return NET_XMIT_DROP;
302 max_single = ieee802154_max_payload(&wpan_hdr);
304 if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
305 skb->dev = lowpan_802154_dev(ldev)->wdev;
306 ldev->stats.tx_packets++;
307 ldev->stats.tx_bytes += dgram_size;
308 return dev_queue_xmit(skb);
312 pr_debug("frame is too big, fragmentation is needed\n");
313 rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
316 return rc < 0 ? NET_XMIT_DROP : rc;