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-rw-r--r--net/wireless/radiotap.c305
1 files changed, 198 insertions, 107 deletions
diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c
index f591871a7b4..1332c445d1c 100644
--- a/net/wireless/radiotap.c
+++ b/net/wireless/radiotap.c
@@ -2,6 +2,16 @@
2 * Radiotap parser 2 * Radiotap parser
3 * 3 *
4 * Copyright 2007 Andy Green <andy@warmcat.com> 4 * Copyright 2007 Andy Green <andy@warmcat.com>
5 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * Alternatively, this software may be distributed under the terms of BSD
12 * license.
13 *
14 * See COPYING for more details.
5 */ 15 */
6 16
7#include <net/cfg80211.h> 17#include <net/cfg80211.h>
@@ -10,6 +20,35 @@
10 20
11/* function prototypes and related defs are in include/net/cfg80211.h */ 21/* function prototypes and related defs are in include/net/cfg80211.h */
12 22
23static const struct radiotap_align_size rtap_namespace_sizes[] = {
24 [IEEE80211_RADIOTAP_TSFT] = { .align = 8, .size = 8, },
25 [IEEE80211_RADIOTAP_FLAGS] = { .align = 1, .size = 1, },
26 [IEEE80211_RADIOTAP_RATE] = { .align = 1, .size = 1, },
27 [IEEE80211_RADIOTAP_CHANNEL] = { .align = 2, .size = 4, },
28 [IEEE80211_RADIOTAP_FHSS] = { .align = 2, .size = 2, },
29 [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = { .align = 1, .size = 1, },
30 [IEEE80211_RADIOTAP_DBM_ANTNOISE] = { .align = 1, .size = 1, },
31 [IEEE80211_RADIOTAP_LOCK_QUALITY] = { .align = 2, .size = 2, },
32 [IEEE80211_RADIOTAP_TX_ATTENUATION] = { .align = 2, .size = 2, },
33 [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = { .align = 2, .size = 2, },
34 [IEEE80211_RADIOTAP_DBM_TX_POWER] = { .align = 1, .size = 1, },
35 [IEEE80211_RADIOTAP_ANTENNA] = { .align = 1, .size = 1, },
36 [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = { .align = 1, .size = 1, },
37 [IEEE80211_RADIOTAP_DB_ANTNOISE] = { .align = 1, .size = 1, },
38 [IEEE80211_RADIOTAP_RX_FLAGS] = { .align = 2, .size = 2, },
39 [IEEE80211_RADIOTAP_TX_FLAGS] = { .align = 2, .size = 2, },
40 [IEEE80211_RADIOTAP_RTS_RETRIES] = { .align = 1, .size = 1, },
41 [IEEE80211_RADIOTAP_DATA_RETRIES] = { .align = 1, .size = 1, },
42 /*
43 * add more here as they are defined in radiotap.h
44 */
45};
46
47static const struct ieee80211_radiotap_namespace radiotap_ns = {
48 .n_bits = sizeof(rtap_namespace_sizes) / sizeof(rtap_namespace_sizes[0]),
49 .align_size = rtap_namespace_sizes,
50};
51
13/** 52/**
14 * ieee80211_radiotap_iterator_init - radiotap parser iterator initialization 53 * ieee80211_radiotap_iterator_init - radiotap parser iterator initialization
15 * @iterator: radiotap_iterator to initialize 54 * @iterator: radiotap_iterator to initialize
@@ -50,9 +89,9 @@
50 */ 89 */
51 90
52int ieee80211_radiotap_iterator_init( 91int ieee80211_radiotap_iterator_init(
53 struct ieee80211_radiotap_iterator *iterator, 92 struct ieee80211_radiotap_iterator *iterator,
54 struct ieee80211_radiotap_header *radiotap_header, 93 struct ieee80211_radiotap_header *radiotap_header,
55 int max_length) 94 int max_length, const struct ieee80211_radiotap_vendor_namespaces *vns)
56{ 95{
57 /* Linux only supports version 0 radiotap format */ 96 /* Linux only supports version 0 radiotap format */
58 if (radiotap_header->it_version) 97 if (radiotap_header->it_version)
@@ -62,19 +101,24 @@ int ieee80211_radiotap_iterator_init(
62 if (max_length < get_unaligned_le16(&radiotap_header->it_len)) 101 if (max_length < get_unaligned_le16(&radiotap_header->it_len))
63 return -EINVAL; 102 return -EINVAL;
64 103
65 iterator->rtheader = radiotap_header; 104 iterator->_rtheader = radiotap_header;
66 iterator->max_length = get_unaligned_le16(&radiotap_header->it_len); 105 iterator->_max_length = get_unaligned_le16(&radiotap_header->it_len);
67 iterator->arg_index = 0; 106 iterator->_arg_index = 0;
68 iterator->bitmap_shifter = get_unaligned_le32(&radiotap_header->it_present); 107 iterator->_bitmap_shifter = get_unaligned_le32(&radiotap_header->it_present);
69 iterator->arg = (u8 *)radiotap_header + sizeof(*radiotap_header); 108 iterator->_arg = (uint8_t *)radiotap_header + sizeof(*radiotap_header);
70 iterator->this_arg = NULL; 109 iterator->_reset_on_ext = 0;
110 iterator->_next_bitmap = &radiotap_header->it_present;
111 iterator->_next_bitmap++;
112 iterator->_vns = vns;
113 iterator->current_namespace = &radiotap_ns;
114 iterator->is_radiotap_ns = 1;
71 115
72 /* find payload start allowing for extended bitmap(s) */ 116 /* find payload start allowing for extended bitmap(s) */
73 117
74 if (unlikely(iterator->bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT))) { 118 if (iterator->_bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT)) {
75 while (get_unaligned_le32(iterator->arg) & 119 while (get_unaligned_le32(iterator->_arg) &
76 (1 << IEEE80211_RADIOTAP_EXT)) { 120 (1 << IEEE80211_RADIOTAP_EXT)) {
77 iterator->arg += sizeof(u32); 121 iterator->_arg += sizeof(uint32_t);
78 122
79 /* 123 /*
80 * check for insanity where the present bitmaps 124 * check for insanity where the present bitmaps
@@ -82,12 +126,13 @@ int ieee80211_radiotap_iterator_init(
82 * stated radiotap header length 126 * stated radiotap header length
83 */ 127 */
84 128
85 if (((ulong)iterator->arg - 129 if ((unsigned long)iterator->_arg -
86 (ulong)iterator->rtheader) > iterator->max_length) 130 (unsigned long)iterator->_rtheader >
131 (unsigned long)iterator->_max_length)
87 return -EINVAL; 132 return -EINVAL;
88 } 133 }
89 134
90 iterator->arg += sizeof(u32); 135 iterator->_arg += sizeof(uint32_t);
91 136
92 /* 137 /*
93 * no need to check again for blowing past stated radiotap 138 * no need to check again for blowing past stated radiotap
@@ -96,12 +141,36 @@ int ieee80211_radiotap_iterator_init(
96 */ 141 */
97 } 142 }
98 143
144 iterator->this_arg = iterator->_arg;
145
99 /* we are all initialized happily */ 146 /* we are all initialized happily */
100 147
101 return 0; 148 return 0;
102} 149}
103EXPORT_SYMBOL(ieee80211_radiotap_iterator_init); 150EXPORT_SYMBOL(ieee80211_radiotap_iterator_init);
104 151
152static void find_ns(struct ieee80211_radiotap_iterator *iterator,
153 uint32_t oui, uint8_t subns)
154{
155 int i;
156
157 iterator->current_namespace = NULL;
158
159 if (!iterator->_vns)
160 return;
161
162 for (i = 0; i < iterator->_vns->n_ns; i++) {
163 if (iterator->_vns->ns[i].oui != oui)
164 continue;
165 if (iterator->_vns->ns[i].subns != subns)
166 continue;
167
168 iterator->current_namespace = &iterator->_vns->ns[i];
169 break;
170 }
171}
172
173
105 174
106/** 175/**
107 * ieee80211_radiotap_iterator_next - return next radiotap parser iterator arg 176 * ieee80211_radiotap_iterator_next - return next radiotap parser iterator arg
@@ -127,99 +196,80 @@ EXPORT_SYMBOL(ieee80211_radiotap_iterator_init);
127 */ 196 */
128 197
129int ieee80211_radiotap_iterator_next( 198int ieee80211_radiotap_iterator_next(
130 struct ieee80211_radiotap_iterator *iterator) 199 struct ieee80211_radiotap_iterator *iterator)
131{ 200{
132 201 while (1) {
133 /*
134 * small length lookup table for all radiotap types we heard of
135 * starting from b0 in the bitmap, so we can walk the payload
136 * area of the radiotap header
137 *
138 * There is a requirement to pad args, so that args
139 * of a given length must begin at a boundary of that length
140 * -- but note that compound args are allowed (eg, 2 x u16
141 * for IEEE80211_RADIOTAP_CHANNEL) so total arg length is not
142 * a reliable indicator of alignment requirement.
143 *
144 * upper nybble: content alignment for arg
145 * lower nybble: content length for arg
146 */
147
148 static const u8 rt_sizes[] = {
149 [IEEE80211_RADIOTAP_TSFT] = 0x88,
150 [IEEE80211_RADIOTAP_FLAGS] = 0x11,
151 [IEEE80211_RADIOTAP_RATE] = 0x11,
152 [IEEE80211_RADIOTAP_CHANNEL] = 0x24,
153 [IEEE80211_RADIOTAP_FHSS] = 0x22,
154 [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = 0x11,
155 [IEEE80211_RADIOTAP_DBM_ANTNOISE] = 0x11,
156 [IEEE80211_RADIOTAP_LOCK_QUALITY] = 0x22,
157 [IEEE80211_RADIOTAP_TX_ATTENUATION] = 0x22,
158 [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = 0x22,
159 [IEEE80211_RADIOTAP_DBM_TX_POWER] = 0x11,
160 [IEEE80211_RADIOTAP_ANTENNA] = 0x11,
161 [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = 0x11,
162 [IEEE80211_RADIOTAP_DB_ANTNOISE] = 0x11,
163 [IEEE80211_RADIOTAP_RX_FLAGS] = 0x22,
164 [IEEE80211_RADIOTAP_TX_FLAGS] = 0x22,
165 [IEEE80211_RADIOTAP_RTS_RETRIES] = 0x11,
166 [IEEE80211_RADIOTAP_DATA_RETRIES] = 0x11,
167 /*
168 * add more here as they are defined in
169 * include/net/ieee80211_radiotap.h
170 */
171 };
172
173 /*
174 * for every radiotap entry we can at
175 * least skip (by knowing the length)...
176 */
177
178 while (iterator->arg_index < sizeof(rt_sizes)) {
179 int hit = 0; 202 int hit = 0;
180 int pad; 203 int pad, align, size, subns, vnslen;
204 uint32_t oui;
181 205
182 if (!(iterator->bitmap_shifter & 1)) 206 /* if no more EXT bits, that's it */
207 if ((iterator->_arg_index % 32) == IEEE80211_RADIOTAP_EXT &&
208 !(iterator->_bitmap_shifter & 1))
209 return -ENOENT;
210
211 if (!(iterator->_bitmap_shifter & 1))
183 goto next_entry; /* arg not present */ 212 goto next_entry; /* arg not present */
184 213
214 /* get alignment/size of data */
215 switch (iterator->_arg_index % 32) {
216 case IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE:
217 case IEEE80211_RADIOTAP_EXT:
218 align = 1;
219 size = 0;
220 break;
221 case IEEE80211_RADIOTAP_VENDOR_NAMESPACE:
222 align = 2;
223 size = 6;
224 break;
225 default:
226 if (!iterator->current_namespace ||
227 iterator->_arg_index >= iterator->current_namespace->n_bits) {
228 if (iterator->current_namespace == &radiotap_ns)
229 return -ENOENT;
230 align = 0;
231 } else {
232 align = iterator->current_namespace->align_size[iterator->_arg_index].align;
233 size = iterator->current_namespace->align_size[iterator->_arg_index].size;
234 }
235 if (!align) {
236 /* skip all subsequent data */
237 iterator->_arg = iterator->_next_ns_data;
238 /* give up on this namespace */
239 iterator->current_namespace = NULL;
240 goto next_entry;
241 }
242 break;
243 }
244
185 /* 245 /*
186 * arg is present, account for alignment padding 246 * arg is present, account for alignment padding
187 * 8-bit args can be at any alignment
188 * 16-bit args must start on 16-bit boundary
189 * 32-bit args must start on 32-bit boundary
190 * 64-bit args must start on 64-bit boundary
191 * 247 *
192 * note that total arg size can differ from alignment of 248 * Note that these alignments are relative to the start
193 * elements inside arg, so we use upper nybble of length 249 * of the radiotap header. There is no guarantee
194 * table to base alignment on
195 *
196 * also note: these alignments are ** relative to the
197 * start of the radiotap header **. There is no guarantee
198 * that the radiotap header itself is aligned on any 250 * that the radiotap header itself is aligned on any
199 * kind of boundary. 251 * kind of boundary.
200 * 252 *
201 * the above is why get_unaligned() is used to dereference 253 * The above is why get_unaligned() is used to dereference
202 * multibyte elements from the radiotap area 254 * multibyte elements from the radiotap area.
203 */ 255 */
204 256
205 pad = (((ulong)iterator->arg) - 257 pad = ((unsigned long)iterator->_arg -
206 ((ulong)iterator->rtheader)) & 258 (unsigned long)iterator->_rtheader) & (align - 1);
207 ((rt_sizes[iterator->arg_index] >> 4) - 1);
208 259
209 if (pad) 260 if (pad)
210 iterator->arg += 261 iterator->_arg += align - pad;
211 (rt_sizes[iterator->arg_index] >> 4) - pad;
212 262
213 /* 263 /*
214 * this is what we will return to user, but we need to 264 * this is what we will return to user, but we need to
215 * move on first so next call has something fresh to test 265 * move on first so next call has something fresh to test
216 */ 266 */
217 iterator->this_arg_index = iterator->arg_index; 267 iterator->this_arg_index = iterator->_arg_index;
218 iterator->this_arg = iterator->arg; 268 iterator->this_arg = iterator->_arg;
219 hit = 1; 269 iterator->this_arg_size = size;
220 270
221 /* internally move on the size of this arg */ 271 /* internally move on the size of this arg */
222 iterator->arg += rt_sizes[iterator->arg_index] & 0x0f; 272 iterator->_arg += size;
223 273
224 /* 274 /*
225 * check for insanity where we are given a bitmap that 275 * check for insanity where we are given a bitmap that
@@ -228,32 +278,73 @@ int ieee80211_radiotap_iterator_next(
228 * max_length on the last arg, never exceeding it. 278 * max_length on the last arg, never exceeding it.
229 */ 279 */
230 280
231 if (((ulong)iterator->arg - (ulong)iterator->rtheader) > 281 if ((unsigned long)iterator->_arg -
232 iterator->max_length) 282 (unsigned long)iterator->_rtheader >
283 (unsigned long)iterator->_max_length)
233 return -EINVAL; 284 return -EINVAL;
234 285
235 next_entry: 286 /* these special ones are valid in each bitmap word */
236 iterator->arg_index++; 287 switch (iterator->_arg_index % 32) {
237 if (unlikely((iterator->arg_index & 31) == 0)) { 288 case IEEE80211_RADIOTAP_VENDOR_NAMESPACE:
238 /* completed current u32 bitmap */ 289 iterator->_bitmap_shifter >>= 1;
239 if (iterator->bitmap_shifter & 1) { 290 iterator->_arg_index++;
240 /* b31 was set, there is more */ 291
241 /* move to next u32 bitmap */ 292 iterator->_reset_on_ext = 1;
242 iterator->bitmap_shifter = 293
243 get_unaligned_le32(iterator->next_bitmap); 294 vnslen = get_unaligned_le16(iterator->this_arg + 4);
244 iterator->next_bitmap++; 295 iterator->_next_ns_data = iterator->_arg + vnslen;
245 } else 296 oui = (*iterator->this_arg << 16) |
246 /* no more bitmaps: end */ 297 (*(iterator->this_arg + 1) << 8) |
247 iterator->arg_index = sizeof(rt_sizes); 298 *(iterator->this_arg + 2);
248 } else /* just try the next bit */ 299 subns = *(iterator->this_arg + 3);
249 iterator->bitmap_shifter >>= 1; 300
301 find_ns(iterator, oui, subns);
302
303 iterator->is_radiotap_ns = 0;
304 /* allow parsers to show this information */
305 iterator->this_arg_index =
306 IEEE80211_RADIOTAP_VENDOR_NAMESPACE;
307 iterator->this_arg_size += vnslen;
308 if ((unsigned long)iterator->this_arg +
309 iterator->this_arg_size -
310 (unsigned long)iterator->_rtheader >
311 (unsigned long)(unsigned long)iterator->_max_length)
312 return -EINVAL;
313 hit = 1;
314 break;
315 case IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE:
316 iterator->_bitmap_shifter >>= 1;
317 iterator->_arg_index++;
318
319 iterator->_reset_on_ext = 1;
320 iterator->current_namespace = &radiotap_ns;
321 iterator->is_radiotap_ns = 1;
322 break;
323 case IEEE80211_RADIOTAP_EXT:
324 /*
325 * bit 31 was set, there is more
326 * -- move to next u32 bitmap
327 */
328 iterator->_bitmap_shifter =
329 get_unaligned_le32(iterator->_next_bitmap);
330 iterator->_next_bitmap++;
331 if (iterator->_reset_on_ext)
332 iterator->_arg_index = 0;
333 else
334 iterator->_arg_index++;
335 iterator->_reset_on_ext = 0;
336 break;
337 default:
338 /* we've got a hit! */
339 hit = 1;
340 next_entry:
341 iterator->_bitmap_shifter >>= 1;
342 iterator->_arg_index++;
343 }
250 344
251 /* if we found a valid arg earlier, return it now */ 345 /* if we found a valid arg earlier, return it now */
252 if (hit) 346 if (hit)
253 return 0; 347 return 0;
254 } 348 }
255
256 /* we don't know how to handle any more args, we're done */
257 return -ENOENT;
258} 349}
259EXPORT_SYMBOL(ieee80211_radiotap_iterator_next); 350EXPORT_SYMBOL(ieee80211_radiotap_iterator_next);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-21 04:14:50 -0500