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/ieee802154_netdev.h>
13 #include <net/mac802154.h>
15 #include "6lowpan_i.h"
17 #define LOWPAN_FRAG1_HEAD_SIZE 0x4
18 #define LOWPAN_FRAGN_HEAD_SIZE 0x5
20 /* don't save pan id, it's intra pan */
24 /* IPv6 needs big endian here */
30 struct lowpan_addr_info {
31 struct lowpan_addr daddr;
32 struct lowpan_addr saddr;
36 lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
38 WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
39 return (struct lowpan_addr_info *)(skb->data -
40 sizeof(struct lowpan_addr_info));
43 /* This callback will be called from AF_PACKET and IPv6 stack, the AF_PACKET
44 * sockets gives an 8 byte array for addresses only!
46 * TODO I think AF_PACKET DGRAM (sending/receiving) RAW (sending) makes no
47 * sense here. We should disable it, the right use-case would be AF_INET6
50 int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev,
51 unsigned short type, const void *_daddr,
52 const void *_saddr, unsigned int len)
54 const u8 *saddr = _saddr;
55 const u8 *daddr = _daddr;
56 struct lowpan_addr_info *info;
62 * if this package isn't ipv6 one, where should it be routed?
64 if (type != ETH_P_IPV6)
68 saddr = ldev->dev_addr;
70 raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
71 raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
73 info = lowpan_skb_priv(skb);
75 /* TODO: Currently we only support extended_addr */
76 info->daddr.mode = IEEE802154_ADDR_LONG;
77 memcpy(&info->daddr.u.extended_addr, daddr,
78 sizeof(info->daddr.u.extended_addr));
79 info->saddr.mode = IEEE802154_ADDR_LONG;
80 memcpy(&info->saddr.u.extended_addr, saddr,
81 sizeof(info->daddr.u.extended_addr));
86 static struct sk_buff*
87 lowpan_alloc_frag(struct sk_buff *skb, int size,
88 const struct ieee802154_hdr *master_hdr, bool frag1)
90 struct net_device *wdev = lowpan_dev_info(skb->dev)->wdev;
94 frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size,
99 frag->priority = skb->priority;
100 skb_reserve(frag, wdev->needed_headroom);
101 skb_reset_network_header(frag);
102 *mac_cb(frag) = *mac_cb(skb);
105 memcpy(skb_put(frag, skb->mac_len),
106 skb_mac_header(skb), skb->mac_len);
108 rc = wpan_dev_hard_header(frag, wdev,
110 &master_hdr->source, size);
117 frag = ERR_PTR(-ENOMEM);
124 lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
125 u8 *frag_hdr, int frag_hdrlen,
126 int offset, int len, bool frag1)
128 struct sk_buff *frag;
130 raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
132 frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1);
134 return PTR_ERR(frag);
136 memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen);
137 memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len);
139 raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
141 return dev_queue_xmit(frag);
145 lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
146 const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
151 int frag_cap, frag_len, payload_cap, rc;
152 int skb_unprocessed, skb_offset;
154 frag_tag = htons(lowpan_dev_info(ldev)->fragment_tag);
155 lowpan_dev_info(ldev)->fragment_tag++;
157 frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07);
158 frag_hdr[1] = dgram_size & 0xff;
159 memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
161 payload_cap = ieee802154_max_payload(wpan_hdr);
163 frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
164 skb_network_header_len(skb), 8);
166 skb_offset = skb_network_header_len(skb);
167 skb_unprocessed = skb->len - skb->mac_len - skb_offset;
169 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
170 LOWPAN_FRAG1_HEAD_SIZE, 0,
171 frag_len + skb_network_header_len(skb),
174 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
175 __func__, ntohs(frag_tag));
179 frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
180 frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN;
181 frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
184 dgram_offset += frag_len;
185 skb_offset += frag_len;
186 skb_unprocessed -= frag_len;
187 frag_len = min(frag_cap, skb_unprocessed);
189 frag_hdr[4] = dgram_offset >> 3;
191 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
192 LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
195 pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
196 __func__, ntohs(frag_tag), skb_offset);
199 } while (skb_unprocessed > frag_cap);
201 ldev->stats.tx_packets++;
202 ldev->stats.tx_bytes += dgram_size;
204 return NET_XMIT_SUCCESS;
211 static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
212 u16 *dgram_size, u16 *dgram_offset)
214 struct wpan_dev *wpan_dev = lowpan_dev_info(ldev)->wdev->ieee802154_ptr;
215 struct ieee802154_addr sa, da;
216 struct ieee802154_mac_cb *cb = mac_cb_init(skb);
217 struct lowpan_addr_info info;
220 memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
222 /* TODO: Currently we only support extended_addr */
223 daddr = &info.daddr.u.extended_addr;
224 saddr = &info.saddr.u.extended_addr;
226 *dgram_size = skb->len;
227 lowpan_header_compress(skb, ldev, daddr, saddr);
228 /* dgram_offset = (saved bytes after compression) + lowpan header len */
229 *dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb);
231 cb->type = IEEE802154_FC_TYPE_DATA;
233 /* prepare wpan address data */
234 sa.mode = IEEE802154_ADDR_LONG;
235 sa.pan_id = wpan_dev->pan_id;
236 sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
238 /* intra-PAN communications */
239 da.pan_id = sa.pan_id;
241 /* if the destination address is the broadcast address, use the
242 * corresponding short address
244 if (!memcmp(daddr, ldev->broadcast, EUI64_ADDR_LEN)) {
245 da.mode = IEEE802154_ADDR_SHORT;
246 da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
249 da.mode = IEEE802154_ADDR_LONG;
250 da.extended_addr = ieee802154_devaddr_from_raw(daddr);
251 cb->ackreq = wpan_dev->ackreq;
254 return wpan_dev_hard_header(skb, lowpan_dev_info(ldev)->wdev, &da, &sa,
258 netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
260 struct ieee802154_hdr wpan_hdr;
262 u16 dgram_size, dgram_offset;
264 pr_debug("package xmit\n");
266 WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);
268 /* We must take a copy of the skb before we modify/replace the ipv6
269 * header as the header could be used elsewhere
271 if (unlikely(skb_headroom(skb) < ldev->needed_headroom ||
272 skb_tailroom(skb) < ldev->needed_tailroom)) {
273 struct sk_buff *nskb;
275 nskb = skb_copy_expand(skb, ldev->needed_headroom,
276 ldev->needed_tailroom, GFP_ATOMIC);
282 return NET_XMIT_DROP;
285 skb = skb_unshare(skb, GFP_ATOMIC);
287 return NET_XMIT_DROP;
290 ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
293 return NET_XMIT_DROP;
296 if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
298 return NET_XMIT_DROP;
301 max_single = ieee802154_max_payload(&wpan_hdr);
303 if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
304 skb->dev = lowpan_dev_info(ldev)->wdev;
305 ldev->stats.tx_packets++;
306 ldev->stats.tx_bytes += dgram_size;
307 return dev_queue_xmit(skb);
311 pr_debug("frame is too big, fragmentation is needed\n");
312 rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
315 return rc < 0 ? NET_XMIT_DROP : rc;