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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. | |
4 | * | |
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. | |
9 | */ | |
10 | ||
11 | #include <net/6lowpan.h> | |
12 | #include <net/ieee802154_netdev.h> | |
13 | ||
14 | #include "6lowpan_i.h" | |
15 | ||
16 | /* don't save pan id, it's intra pan */ | |
17 | struct lowpan_addr { | |
18 | u8 mode; | |
19 | union { | |
20 | /* IPv6 needs big endian here */ | |
21 | __be64 extended_addr; | |
22 | __be16 short_addr; | |
23 | } u; | |
24 | }; | |
25 | ||
26 | struct lowpan_addr_info { | |
27 | struct lowpan_addr daddr; | |
28 | struct lowpan_addr saddr; | |
29 | }; | |
30 | ||
31 | static inline struct | |
32 | lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb) | |
33 | { | |
34 | WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info)); | |
35 | return (struct lowpan_addr_info *)(skb->data - | |
36 | sizeof(struct lowpan_addr_info)); | |
37 | } | |
38 | ||
39 | int lowpan_header_create(struct sk_buff *skb, struct net_device *dev, | |
40 | unsigned short type, const void *_daddr, | |
41 | const void *_saddr, unsigned int len) | |
42 | { | |
43 | const u8 *saddr = _saddr; | |
44 | const u8 *daddr = _daddr; | |
45 | struct lowpan_addr_info *info; | |
46 | ||
47 | /* TODO: | |
48 | * if this package isn't ipv6 one, where should it be routed? | |
49 | */ | |
50 | if (type != ETH_P_IPV6) | |
51 | return 0; | |
52 | ||
53 | if (!saddr) | |
54 | saddr = dev->dev_addr; | |
55 | ||
56 | raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8); | |
57 | raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8); | |
58 | ||
59 | info = lowpan_skb_priv(skb); | |
60 | ||
61 | /* TODO: Currently we only support extended_addr */ | |
62 | info->daddr.mode = IEEE802154_ADDR_LONG; | |
63 | memcpy(&info->daddr.u.extended_addr, daddr, | |
64 | sizeof(info->daddr.u.extended_addr)); | |
65 | info->saddr.mode = IEEE802154_ADDR_LONG; | |
66 | memcpy(&info->saddr.u.extended_addr, saddr, | |
67 | sizeof(info->daddr.u.extended_addr)); | |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
72 | static struct sk_buff* | |
73 | lowpan_alloc_frag(struct sk_buff *skb, int size, | |
74 | const struct ieee802154_hdr *master_hdr) | |
75 | { | |
76 | struct net_device *real_dev = lowpan_dev_info(skb->dev)->real_dev; | |
77 | struct sk_buff *frag; | |
78 | int rc; | |
79 | ||
80 | frag = alloc_skb(real_dev->hard_header_len + | |
81 | real_dev->needed_tailroom + size, | |
82 | GFP_ATOMIC); | |
83 | ||
84 | if (likely(frag)) { | |
85 | frag->dev = real_dev; | |
86 | frag->priority = skb->priority; | |
87 | skb_reserve(frag, real_dev->hard_header_len); | |
88 | skb_reset_network_header(frag); | |
89 | *mac_cb(frag) = *mac_cb(skb); | |
90 | ||
91 | rc = dev_hard_header(frag, real_dev, 0, &master_hdr->dest, | |
92 | &master_hdr->source, size); | |
93 | if (rc < 0) { | |
94 | kfree_skb(frag); | |
95 | return ERR_PTR(rc); | |
96 | } | |
97 | } else { | |
98 | frag = ERR_PTR(-ENOMEM); | |
99 | } | |
100 | ||
101 | return frag; | |
102 | } | |
103 | ||
104 | static int | |
105 | lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr, | |
106 | u8 *frag_hdr, int frag_hdrlen, | |
107 | int offset, int len) | |
108 | { | |
109 | struct sk_buff *frag; | |
110 | ||
111 | raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen); | |
112 | ||
113 | frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr); | |
114 | if (IS_ERR(frag)) | |
115 | return -PTR_ERR(frag); | |
116 | ||
117 | memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen); | |
118 | memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len); | |
119 | ||
120 | raw_dump_table(__func__, " fragment dump", frag->data, frag->len); | |
121 | ||
122 | return dev_queue_xmit(frag); | |
123 | } | |
124 | ||
125 | static int | |
126 | lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *dev, | |
127 | const struct ieee802154_hdr *wpan_hdr) | |
128 | { | |
129 | u16 dgram_size, dgram_offset; | |
130 | __be16 frag_tag; | |
131 | u8 frag_hdr[5]; | |
132 | int frag_cap, frag_len, payload_cap, rc; | |
133 | int skb_unprocessed, skb_offset; | |
134 | ||
135 | dgram_size = lowpan_uncompress_size(skb, &dgram_offset) - | |
136 | skb->mac_len; | |
137 | frag_tag = htons(lowpan_dev_info(dev)->fragment_tag); | |
138 | lowpan_dev_info(dev)->fragment_tag++; | |
139 | ||
140 | frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07); | |
141 | frag_hdr[1] = dgram_size & 0xff; | |
142 | memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag)); | |
143 | ||
144 | payload_cap = ieee802154_max_payload(wpan_hdr); | |
145 | ||
146 | frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE - | |
147 | skb_network_header_len(skb), 8); | |
148 | ||
149 | skb_offset = skb_network_header_len(skb); | |
150 | skb_unprocessed = skb->len - skb->mac_len - skb_offset; | |
151 | ||
152 | rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr, | |
153 | LOWPAN_FRAG1_HEAD_SIZE, 0, | |
154 | frag_len + skb_network_header_len(skb)); | |
155 | if (rc) { | |
156 | pr_debug("%s unable to send FRAG1 packet (tag: %d)", | |
157 | __func__, ntohs(frag_tag)); | |
158 | goto err; | |
159 | } | |
160 | ||
161 | frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1; | |
162 | frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN; | |
163 | frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8); | |
164 | ||
165 | do { | |
166 | dgram_offset += frag_len; | |
167 | skb_offset += frag_len; | |
168 | skb_unprocessed -= frag_len; | |
169 | frag_len = min(frag_cap, skb_unprocessed); | |
170 | ||
171 | frag_hdr[4] = dgram_offset >> 3; | |
172 | ||
173 | rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr, | |
174 | LOWPAN_FRAGN_HEAD_SIZE, skb_offset, | |
175 | frag_len); | |
176 | if (rc) { | |
177 | pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n", | |
178 | __func__, ntohs(frag_tag), skb_offset); | |
179 | goto err; | |
180 | } | |
181 | } while (skb_unprocessed > frag_cap); | |
182 | ||
183 | consume_skb(skb); | |
184 | return NET_XMIT_SUCCESS; | |
185 | ||
186 | err: | |
187 | kfree_skb(skb); | |
188 | return rc; | |
189 | } | |
190 | ||
191 | static int lowpan_header(struct sk_buff *skb, struct net_device *dev) | |
192 | { | |
193 | struct ieee802154_addr sa, da; | |
194 | struct ieee802154_mac_cb *cb = mac_cb_init(skb); | |
195 | struct lowpan_addr_info info; | |
196 | void *daddr, *saddr; | |
197 | ||
198 | memcpy(&info, lowpan_skb_priv(skb), sizeof(info)); | |
199 | ||
200 | /* TODO: Currently we only support extended_addr */ | |
201 | daddr = &info.daddr.u.extended_addr; | |
202 | saddr = &info.saddr.u.extended_addr; | |
203 | ||
204 | lowpan_header_compress(skb, dev, ETH_P_IPV6, daddr, saddr, skb->len); | |
205 | ||
206 | cb->type = IEEE802154_FC_TYPE_DATA; | |
207 | ||
208 | /* prepare wpan address data */ | |
209 | sa.mode = IEEE802154_ADDR_LONG; | |
210 | sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev); | |
211 | sa.extended_addr = ieee802154_devaddr_from_raw(saddr); | |
212 | ||
213 | /* intra-PAN communications */ | |
214 | da.pan_id = sa.pan_id; | |
215 | ||
216 | /* if the destination address is the broadcast address, use the | |
217 | * corresponding short address | |
218 | */ | |
219 | if (lowpan_is_addr_broadcast((const u8 *)daddr)) { | |
220 | da.mode = IEEE802154_ADDR_SHORT; | |
221 | da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST); | |
222 | cb->ackreq = false; | |
223 | } else { | |
224 | da.mode = IEEE802154_ADDR_LONG; | |
225 | da.extended_addr = ieee802154_devaddr_from_raw(daddr); | |
226 | cb->ackreq = true; | |
227 | } | |
228 | ||
229 | return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev, | |
230 | ETH_P_IPV6, (void *)&da, (void *)&sa, 0); | |
231 | } | |
232 | ||
233 | netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev) | |
234 | { | |
235 | struct ieee802154_hdr wpan_hdr; | |
236 | int max_single, ret; | |
237 | ||
238 | pr_debug("package xmit\n"); | |
239 | ||
240 | /* We must take a copy of the skb before we modify/replace the ipv6 | |
241 | * header as the header could be used elsewhere | |
242 | */ | |
243 | skb = skb_unshare(skb, GFP_ATOMIC); | |
244 | if (!skb) | |
245 | return NET_XMIT_DROP; | |
246 | ||
247 | ret = lowpan_header(skb, dev); | |
248 | if (ret < 0) { | |
249 | kfree_skb(skb); | |
250 | return NET_XMIT_DROP; | |
251 | } | |
252 | ||
253 | if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) { | |
254 | kfree_skb(skb); | |
255 | return NET_XMIT_DROP; | |
256 | } | |
257 | ||
258 | max_single = ieee802154_max_payload(&wpan_hdr); | |
259 | ||
260 | if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) { | |
261 | skb->dev = lowpan_dev_info(dev)->real_dev; | |
262 | return dev_queue_xmit(skb); | |
263 | } else { | |
264 | netdev_tx_t rc; | |
265 | ||
266 | pr_debug("frame is too big, fragmentation is needed\n"); | |
267 | rc = lowpan_xmit_fragmented(skb, dev, &wpan_hdr); | |
268 | ||
269 | return rc < 0 ? NET_XMIT_DROP : rc; | |
270 | } | |
271 | } |