1
2
3
4
5
6
7
8
9
10
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
36
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 memcpy(skb_put(frag, skb->mac_len),
125 skb_mac_header(skb), skb->mac_len);
126 } else {
127 rc = wpan_dev_hard_header(frag, wdev,
128 &master_hdr->dest,
129 &master_hdr->source, size);
130 if (rc < 0) {
131 kfree_skb(frag);
132 return ERR_PTR(rc);
133 }
134 }
135 } else {
136 frag = ERR_PTR(-ENOMEM);
137 }
138
139 return frag;
140}
141
142static int
143lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
144 u8 *frag_hdr, int frag_hdrlen,
145 int offset, int len, bool frag1)
146{
147 struct sk_buff *frag;
148
149 raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
150
151 frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1);
152 if (IS_ERR(frag))
153 return PTR_ERR(frag);
154
155 memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen);
156 memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len);
157
158 raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
159
160 return dev_queue_xmit(frag);
161}
162
163static int
164lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
165 const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
166 u16 dgram_offset)
167{
168 __be16 frag_tag;
169 u8 frag_hdr[5];
170 int frag_cap, frag_len, payload_cap, rc;
171 int skb_unprocessed, skb_offset;
172
173 frag_tag = htons(lowpan_802154_dev(ldev)->fragment_tag);
174 lowpan_802154_dev(ldev)->fragment_tag++;
175
176 frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07);
177 frag_hdr[1] = dgram_size & 0xff;
178 memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
179
180 payload_cap = ieee802154_max_payload(wpan_hdr);
181
182 frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
183 skb_network_header_len(skb), 8);
184
185 skb_offset = skb_network_header_len(skb);
186 skb_unprocessed = skb->len - skb->mac_len - skb_offset;
187
188 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
189 LOWPAN_FRAG1_HEAD_SIZE, 0,
190 frag_len + skb_network_header_len(skb),
191 true);
192 if (rc) {
193 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
194 __func__, ntohs(frag_tag));
195 goto err;
196 }
197
198 frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
199 frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN;
200 frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
201
202 do {
203 dgram_offset += frag_len;
204 skb_offset += frag_len;
205 skb_unprocessed -= frag_len;
206 frag_len = min(frag_cap, skb_unprocessed);
207
208 frag_hdr[4] = dgram_offset >> 3;
209
210 rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
211 LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
212 frag_len, false);
213 if (rc) {
214 pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
215 __func__, ntohs(frag_tag), skb_offset);
216 goto err;
217 }
218 } while (skb_unprocessed > frag_cap);
219
220 ldev->stats.tx_packets++;
221 ldev->stats.tx_bytes += dgram_size;
222 consume_skb(skb);
223 return NET_XMIT_SUCCESS;
224
225err:
226 kfree_skb(skb);
227 return rc;
228}
229
230static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
231 u16 *dgram_size, u16 *dgram_offset)
232{
233 struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
234 struct ieee802154_mac_cb *cb = mac_cb_init(skb);
235 struct lowpan_addr_info info;
236
237 memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
238
239 *dgram_size = skb->len;
240 lowpan_header_compress(skb, ldev, &info.daddr, &info.saddr);
241
242 *dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb);
243
244 cb->type = IEEE802154_FC_TYPE_DATA;
245
246 if (info.daddr.mode == IEEE802154_ADDR_SHORT &&
247 ieee802154_is_broadcast_short_addr(info.daddr.short_addr))
248 cb->ackreq = false;
249 else
250 cb->ackreq = wpan_dev->ackreq;
251
252 return wpan_dev_hard_header(skb, lowpan_802154_dev(ldev)->wdev,
253 &info.daddr, &info.saddr, 0);
254}
255
256netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
257{
258 struct ieee802154_hdr wpan_hdr;
259 int max_single, ret;
260 u16 dgram_size, dgram_offset;
261
262 pr_debug("package xmit\n");
263
264 WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);
265
266
267
268
269 skb = skb_unshare(skb, GFP_ATOMIC);
270 if (!skb)
271 return NET_XMIT_DROP;
272
273 ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
274 if (ret < 0) {
275 kfree_skb(skb);
276 return NET_XMIT_DROP;
277 }
278
279 if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
280 kfree_skb(skb);
281 return NET_XMIT_DROP;
282 }
283
284 max_single = ieee802154_max_payload(&wpan_hdr);
285
286 if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
287 skb->dev = lowpan_802154_dev(ldev)->wdev;
288 ldev->stats.tx_packets++;
289 ldev->stats.tx_bytes += dgram_size;
290 return dev_queue_xmit(skb);
291 } else {
292 netdev_tx_t rc;
293
294 pr_debug("frame is too big, fragmentation is needed\n");
295 rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
296 dgram_offset);
297
298 return rc < 0 ? NET_XMIT_DROP : rc;
299 }
300}
301
