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11#include <net/6lowpan.h>
12#include <net/ndisc.h>
13#include <net/ieee802154_netdev.h>
14#include <net/mac802154.h>
15
16#include "6lowpan_i.h"
17
18#define LOWPAN_FRAG1_HEAD_SIZE 0x4
19#define LOWPAN_FRAGN_HEAD_SIZE 0x5
20
21struct lowpan_addr_info {
22 struct ieee802154_addr daddr;
23 struct ieee802154_addr saddr;
24};
25
26static inline struct
27lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
28{
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));
32}
33
34
35
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37
38
39
40
41int 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)
44{
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);
49 struct neighbour *n;
50
51
52
53
54 if (type != ETH_P_IPV6)
55 return 0;
56
57
58 info->saddr.pan_id = wpan_dev->pan_id;
59 info->daddr.pan_id = info->saddr.pan_id;
60
61 if (!memcmp(daddr, ldev->broadcast, EUI64_ADDR_LEN)) {
62 info->daddr.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
63 info->daddr.mode = IEEE802154_ADDR_SHORT;
64 } else {
65 __le16 short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
66
67 n = neigh_lookup(&nd_tbl, &hdr->daddr, ldev);
68 if (n) {
69 llneigh = lowpan_802154_neigh(neighbour_priv(n));
70 read_lock_bh(&n->lock);
71 short_addr = llneigh->short_addr;
72 read_unlock_bh(&n->lock);
73 }
74
75 if (llneigh &&
76 lowpan_802154_is_valid_src_short_addr(short_addr)) {
77 info->daddr.short_addr = short_addr;
78 info->daddr.mode = IEEE802154_ADDR_SHORT;
79 } else {
80 info->daddr.mode = IEEE802154_ADDR_LONG;
81 ieee802154_be64_to_le64(&info->daddr.extended_addr,
82 daddr);
83 }
84
85 if (n)
86 neigh_release(n);
87 }
88
89 if (!saddr) {
90 if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
91 info->saddr.mode = IEEE802154_ADDR_SHORT;
92 info->saddr.short_addr = wpan_dev->short_addr;
93 } else {
94 info->saddr.mode = IEEE802154_ADDR_LONG;
95 info->saddr.extended_addr = wpan_dev->extended_addr;
96 }
97 } else {
98 info->saddr.mode = IEEE802154_ADDR_LONG;
99 ieee802154_be64_to_le64(&info->saddr.extended_addr, saddr);
100 }
101
102 return 0;
103}
104
105static struct sk_buff*
106lowpan_alloc_frag(struct sk_buff *skb, int size,
107 const struct ieee802154_hdr *master_hdr, bool frag1)
108{
109 struct net_device *wdev = lowpan_802154_dev(skb->dev)->wdev;
110 struct sk_buff *frag;
111 int rc;
112
113 frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size,
114 GFP_ATOMIC);
115
116 if (likely(frag)) {
117 frag->dev = wdev;
118 frag->priority = skb->priority;
119 skb_reserve(frag, wdev->needed_headroom);
120 skb_reset_network_header(frag);
121 *mac_cb(frag) = *mac_cb(skb);
122
123 if (frag1) {
124 skb_put_data(frag, skb_mac_header(skb), skb->mac_len);
125 } else {
126 rc = wpan_dev_hard_header(frag, wdev,
127 &master_hdr->dest,
128 &master_hdr->source, size);
129 if (rc < 0) {
130 kfree_skb(frag);
131 return ERR_PTR(rc);
132 }
133 }
134 } else {
135 frag = ERR_PTR(-ENOMEM);
136 }
137
138 return frag;
139}
140
141static int
142lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
143 u8 *frag_hdr, int frag_hdrlen,
144 int offset, int len, bool frag1)
145{
146 struct sk_buff *frag;
147
148 raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
149
150 frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1);
151 if (IS_ERR(frag))
152 return PTR_ERR(frag);
153
154 skb_put_data(frag, frag_hdr, frag_hdrlen);
155 skb_put_data(frag, skb_network_header(skb) + offset, len);
156
157 raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
158
159 return dev_queue_xmit(frag);
160}
161
162static int
163lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
164 const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
165 u16 dgram_offset)
166{
167 __be16 frag_tag;
168 u8 frag_hdr[5];
169 int frag_cap, frag_len, payload_cap, rc;
170 int skb_unprocessed, skb_offset;
171
172 frag_tag = htons(lowpan_802154_dev(ldev)->fragment_tag);
173 lowpan_802154_dev(ldev)->fragment_tag++;
174
175 frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07);
176 frag_hdr[1] = dgram_size & 0xff;
177 memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
178
179 payload_cap = ieee802154_max_payload(wpan_hdr);
180
181 frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
182 skb_network_header_len(skb), 8);
183
184 skb_offset = skb_network_header_len(skb);
185 skb_unprocessed = skb->len - skb->mac_len - skb_offset;
186
187 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
188 LOWPAN_FRAG1_HEAD_SIZE, 0,
189 frag_len + skb_network_header_len(skb),
190 true);
191 if (rc) {
192 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
193 __func__, ntohs(frag_tag));
194 goto err;
195 }
196
197 frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
198 frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN;
199 frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
200
201 do {
202 dgram_offset += frag_len;
203 skb_offset += frag_len;
204 skb_unprocessed -= frag_len;
205 frag_len = min(frag_cap, skb_unprocessed);
206
207 frag_hdr[4] = dgram_offset >> 3;
208
209 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
210 LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
211 frag_len, false);
212 if (rc) {
213 pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
214 __func__, ntohs(frag_tag), skb_offset);
215 goto err;
216 }
217 } while (skb_unprocessed > frag_cap);
218
219 ldev->stats.tx_packets++;
220 ldev->stats.tx_bytes += dgram_size;
221 consume_skb(skb);
222 return NET_XMIT_SUCCESS;
223
224err:
225 kfree_skb(skb);
226 return rc;
227}
228
229static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
230 u16 *dgram_size, u16 *dgram_offset)
231{
232 struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
233 struct ieee802154_mac_cb *cb = mac_cb_init(skb);
234 struct lowpan_addr_info info;
235
236 memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
237
238 *dgram_size = skb->len;
239 lowpan_header_compress(skb, ldev, &info.daddr, &info.saddr);
240
241 *dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb);
242
243 cb->type = IEEE802154_FC_TYPE_DATA;
244
245 if (info.daddr.mode == IEEE802154_ADDR_SHORT &&
246 ieee802154_is_broadcast_short_addr(info.daddr.short_addr))
247 cb->ackreq = false;
248 else
249 cb->ackreq = wpan_dev->ackreq;
250
251 return wpan_dev_hard_header(skb, lowpan_802154_dev(ldev)->wdev,
252 &info.daddr, &info.saddr, 0);
253}
254
255netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
256{
257 struct ieee802154_hdr wpan_hdr;
258 int max_single, ret;
259 u16 dgram_size, dgram_offset;
260
261 pr_debug("package xmit\n");
262
263 WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);
264
265
266
267
268 skb = skb_unshare(skb, GFP_ATOMIC);
269 if (!skb)
270 return NET_XMIT_DROP;
271
272 ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
273 if (ret < 0) {
274 kfree_skb(skb);
275 return NET_XMIT_DROP;
276 }
277
278 if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
279 kfree_skb(skb);
280 return NET_XMIT_DROP;
281 }
282
283 max_single = ieee802154_max_payload(&wpan_hdr);
284
285 if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
286 skb->dev = lowpan_802154_dev(ldev)->wdev;
287 ldev->stats.tx_packets++;
288 ldev->stats.tx_bytes += dgram_size;
289 return dev_queue_xmit(skb);
290 } else {
291 netdev_tx_t rc;
292
293 pr_debug("frame is too big, fragmentation is needed\n");
294 rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
295 dgram_offset);
296
297 return rc < 0 ? NET_XMIT_DROP : rc;
298 }
299}
300
