* Documentation in Documentation/networking/radiotap-headers.txt
*/
+struct radiotap_align_size {
+ uint8_t align:4, size:4;
+};
+
+struct ieee80211_radiotap_namespace {
+ const struct radiotap_align_size *align_size;
+ int n_bits;
+ uint32_t oui;
+ uint8_t subns;
+};
+
+struct ieee80211_radiotap_vendor_namespaces {
+ const struct ieee80211_radiotap_namespace *ns;
+ int n_ns;
+};
+
/**
* struct ieee80211_radiotap_iterator - tracks walk thru present radiotap args
- * @rtheader: pointer to the radiotap header we are walking through
- * @max_length: length of radiotap header in cpu byte ordering
- * @this_arg_index: IEEE80211_RADIOTAP_... index of current arg
- * @this_arg: pointer to current radiotap arg
- * @arg_index: internal next argument index
- * @arg: internal next argument pointer
- * @next_bitmap: internal pointer to next present u32
- * @bitmap_shifter: internal shifter for curr u32 bitmap, b0 set == arg present
+ * @this_arg_index: index of current arg, valid after each successful call
+ * to ieee80211_radiotap_iterator_next()
+ * @this_arg: pointer to current radiotap arg; it is valid after each
+ * call to ieee80211_radiotap_iterator_next() but also after
+ * ieee80211_radiotap_iterator_init() where it will point to
+ * the beginning of the actual data portion
+ * @this_arg_size: length of the current arg, for convenience
+ * @current_namespace: pointer to the current namespace definition
+ * (or internally %NULL if the current namespace is unknown)
+ * @is_radiotap_ns: indicates whether the current namespace is the default
+ * radiotap namespace or not
+ *
+ * @overrides: override standard radiotap fields
+ * @n_overrides: number of overrides
+ *
+ * @_rtheader: pointer to the radiotap header we are walking through
+ * @_max_length: length of radiotap header in cpu byte ordering
+ * @_arg_index: next argument index
+ * @_arg: next argument pointer
+ * @_next_bitmap: internal pointer to next present u32
+ * @_bitmap_shifter: internal shifter for curr u32 bitmap, b0 set == arg present
+ * @_vns: vendor namespace definitions
+ * @_next_ns_data: beginning of the next namespace's data
+ * @_reset_on_ext: internal; reset the arg index to 0 when going to the
+ * next bitmap word
+ *
+ * Describes the radiotap parser state. Fields prefixed with an underscore
+ * must not be used by users of the parser, only by the parser internally.
*/
struct ieee80211_radiotap_iterator {
- struct ieee80211_radiotap_header *rtheader;
- int max_length;
+ struct ieee80211_radiotap_header *_rtheader;
+ const struct ieee80211_radiotap_vendor_namespaces *_vns;
+ const struct ieee80211_radiotap_namespace *current_namespace;
+
+ unsigned char *_arg, *_next_ns_data;
+ uint32_t *_next_bitmap;
+
+ unsigned char *this_arg;
int this_arg_index;
- u8 *this_arg;
+ int this_arg_size;
- int arg_index;
- u8 *arg;
- __le32 *next_bitmap;
- u32 bitmap_shifter;
+ int is_radiotap_ns;
+
+ int _max_length;
+ int _arg_index;
+ uint32_t _bitmap_shifter;
+ int _reset_on_ext;
};
extern int ieee80211_radiotap_iterator_init(
- struct ieee80211_radiotap_iterator *iterator,
- struct ieee80211_radiotap_header *radiotap_header,
- int max_length);
+ struct ieee80211_radiotap_iterator *iterator,
+ struct ieee80211_radiotap_header *radiotap_header,
+ int max_length, const struct ieee80211_radiotap_vendor_namespaces *vns);
extern int ieee80211_radiotap_iterator_next(
- struct ieee80211_radiotap_iterator *iterator);
+ struct ieee80211_radiotap_iterator *iterator);
+
extern const unsigned char rfc1042_header[6];
extern const unsigned char bridge_tunnel_header[6];
* Radiotap parser
*
* Copyright 2007 Andy Green <andy@warmcat.com>
+ * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See COPYING for more details.
*/
#include <net/cfg80211.h>
/* function prototypes and related defs are in include/net/cfg80211.h */
+static const struct radiotap_align_size rtap_namespace_sizes[] = {
+ [IEEE80211_RADIOTAP_TSFT] = { .align = 8, .size = 8, },
+ [IEEE80211_RADIOTAP_FLAGS] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_RATE] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_CHANNEL] = { .align = 2, .size = 4, },
+ [IEEE80211_RADIOTAP_FHSS] = { .align = 2, .size = 2, },
+ [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_DBM_ANTNOISE] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_LOCK_QUALITY] = { .align = 2, .size = 2, },
+ [IEEE80211_RADIOTAP_TX_ATTENUATION] = { .align = 2, .size = 2, },
+ [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = { .align = 2, .size = 2, },
+ [IEEE80211_RADIOTAP_DBM_TX_POWER] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_ANTENNA] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_DB_ANTNOISE] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_RX_FLAGS] = { .align = 2, .size = 2, },
+ [IEEE80211_RADIOTAP_TX_FLAGS] = { .align = 2, .size = 2, },
+ [IEEE80211_RADIOTAP_RTS_RETRIES] = { .align = 1, .size = 1, },
+ [IEEE80211_RADIOTAP_DATA_RETRIES] = { .align = 1, .size = 1, },
+ /*
+ * add more here as they are defined in radiotap.h
+ */
+};
+
+static const struct ieee80211_radiotap_namespace radiotap_ns = {
+ .n_bits = sizeof(rtap_namespace_sizes) / sizeof(rtap_namespace_sizes[0]),
+ .align_size = rtap_namespace_sizes,
+};
+
/**
* ieee80211_radiotap_iterator_init - radiotap parser iterator initialization
* @iterator: radiotap_iterator to initialize
*/
int ieee80211_radiotap_iterator_init(
- struct ieee80211_radiotap_iterator *iterator,
- struct ieee80211_radiotap_header *radiotap_header,
- int max_length)
+ struct ieee80211_radiotap_iterator *iterator,
+ struct ieee80211_radiotap_header *radiotap_header,
+ int max_length, const struct ieee80211_radiotap_vendor_namespaces *vns)
{
/* Linux only supports version 0 radiotap format */
if (radiotap_header->it_version)
if (max_length < get_unaligned_le16(&radiotap_header->it_len))
return -EINVAL;
- iterator->rtheader = radiotap_header;
- iterator->max_length = get_unaligned_le16(&radiotap_header->it_len);
- iterator->arg_index = 0;
- iterator->bitmap_shifter = get_unaligned_le32(&radiotap_header->it_present);
- iterator->arg = (u8 *)radiotap_header + sizeof(*radiotap_header);
- iterator->this_arg = NULL;
+ iterator->_rtheader = radiotap_header;
+ iterator->_max_length = get_unaligned_le16(&radiotap_header->it_len);
+ iterator->_arg_index = 0;
+ iterator->_bitmap_shifter = get_unaligned_le32(&radiotap_header->it_present);
+ iterator->_arg = (uint8_t *)radiotap_header + sizeof(*radiotap_header);
+ iterator->_reset_on_ext = 0;
+ iterator->_next_bitmap = &radiotap_header->it_present;
+ iterator->_next_bitmap++;
+ iterator->_vns = vns;
+ iterator->current_namespace = &radiotap_ns;
+ iterator->is_radiotap_ns = 1;
/* find payload start allowing for extended bitmap(s) */
- if (unlikely(iterator->bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT))) {
- while (get_unaligned_le32(iterator->arg) &
- (1 << IEEE80211_RADIOTAP_EXT)) {
- iterator->arg += sizeof(u32);
+ if (iterator->_bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT)) {
+ while (get_unaligned_le32(iterator->_arg) &
+ (1 << IEEE80211_RADIOTAP_EXT)) {
+ iterator->_arg += sizeof(uint32_t);
/*
* check for insanity where the present bitmaps
* stated radiotap header length
*/
- if (((ulong)iterator->arg -
- (ulong)iterator->rtheader) > iterator->max_length)
+ if ((unsigned long)iterator->_arg -
+ (unsigned long)iterator->_rtheader >
+ (unsigned long)iterator->_max_length)
return -EINVAL;
}
- iterator->arg += sizeof(u32);
+ iterator->_arg += sizeof(uint32_t);
/*
* no need to check again for blowing past stated radiotap
*/
}
+ iterator->this_arg = iterator->_arg;
+
/* we are all initialized happily */
return 0;
}
EXPORT_SYMBOL(ieee80211_radiotap_iterator_init);
+static void find_ns(struct ieee80211_radiotap_iterator *iterator,
+ uint32_t oui, uint8_t subns)
+{
+ int i;
+
+ iterator->current_namespace = NULL;
+
+ if (!iterator->_vns)
+ return;
+
+ for (i = 0; i < iterator->_vns->n_ns; i++) {
+ if (iterator->_vns->ns[i].oui != oui)
+ continue;
+ if (iterator->_vns->ns[i].subns != subns)
+ continue;
+
+ iterator->current_namespace = &iterator->_vns->ns[i];
+ break;
+ }
+}
+
+
/**
* ieee80211_radiotap_iterator_next - return next radiotap parser iterator arg
*/
int ieee80211_radiotap_iterator_next(
- struct ieee80211_radiotap_iterator *iterator)
+ struct ieee80211_radiotap_iterator *iterator)
{
-
- /*
- * small length lookup table for all radiotap types we heard of
- * starting from b0 in the bitmap, so we can walk the payload
- * area of the radiotap header
- *
- * There is a requirement to pad args, so that args
- * of a given length must begin at a boundary of that length
- * -- but note that compound args are allowed (eg, 2 x u16
- * for IEEE80211_RADIOTAP_CHANNEL) so total arg length is not
- * a reliable indicator of alignment requirement.
- *
- * upper nybble: content alignment for arg
- * lower nybble: content length for arg
- */
-
- static const u8 rt_sizes[] = {
- [IEEE80211_RADIOTAP_TSFT] = 0x88,
- [IEEE80211_RADIOTAP_FLAGS] = 0x11,
- [IEEE80211_RADIOTAP_RATE] = 0x11,
- [IEEE80211_RADIOTAP_CHANNEL] = 0x24,
- [IEEE80211_RADIOTAP_FHSS] = 0x22,
- [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = 0x11,
- [IEEE80211_RADIOTAP_DBM_ANTNOISE] = 0x11,
- [IEEE80211_RADIOTAP_LOCK_QUALITY] = 0x22,
- [IEEE80211_RADIOTAP_TX_ATTENUATION] = 0x22,
- [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = 0x22,
- [IEEE80211_RADIOTAP_DBM_TX_POWER] = 0x11,
- [IEEE80211_RADIOTAP_ANTENNA] = 0x11,
- [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = 0x11,
- [IEEE80211_RADIOTAP_DB_ANTNOISE] = 0x11,
- [IEEE80211_RADIOTAP_RX_FLAGS] = 0x22,
- [IEEE80211_RADIOTAP_TX_FLAGS] = 0x22,
- [IEEE80211_RADIOTAP_RTS_RETRIES] = 0x11,
- [IEEE80211_RADIOTAP_DATA_RETRIES] = 0x11,
- /*
- * add more here as they are defined in
- * include/net/ieee80211_radiotap.h
- */
- };
-
- /*
- * for every radiotap entry we can at
- * least skip (by knowing the length)...
- */
-
- while (iterator->arg_index < sizeof(rt_sizes)) {
+ while (1) {
int hit = 0;
- int pad;
+ int pad, align, size, subns, vnslen;
+ uint32_t oui;
- if (!(iterator->bitmap_shifter & 1))
+ /* if no more EXT bits, that's it */
+ if ((iterator->_arg_index % 32) == IEEE80211_RADIOTAP_EXT &&
+ !(iterator->_bitmap_shifter & 1))
+ return -ENOENT;
+
+ if (!(iterator->_bitmap_shifter & 1))
goto next_entry; /* arg not present */
+ /* get alignment/size of data */
+ switch (iterator->_arg_index % 32) {
+ case IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE:
+ case IEEE80211_RADIOTAP_EXT:
+ align = 1;
+ size = 0;
+ break;
+ case IEEE80211_RADIOTAP_VENDOR_NAMESPACE:
+ align = 2;
+ size = 6;
+ break;
+ default:
+ if (!iterator->current_namespace ||
+ iterator->_arg_index >= iterator->current_namespace->n_bits) {
+ if (iterator->current_namespace == &radiotap_ns)
+ return -ENOENT;
+ align = 0;
+ } else {
+ align = iterator->current_namespace->align_size[iterator->_arg_index].align;
+ size = iterator->current_namespace->align_size[iterator->_arg_index].size;
+ }
+ if (!align) {
+ /* skip all subsequent data */
+ iterator->_arg = iterator->_next_ns_data;
+ /* give up on this namespace */
+ iterator->current_namespace = NULL;
+ goto next_entry;
+ }
+ break;
+ }
+
/*
* arg is present, account for alignment padding
- * 8-bit args can be at any alignment
- * 16-bit args must start on 16-bit boundary
- * 32-bit args must start on 32-bit boundary
- * 64-bit args must start on 64-bit boundary
*
- * note that total arg size can differ from alignment of
- * elements inside arg, so we use upper nybble of length
- * table to base alignment on
- *
- * also note: these alignments are ** relative to the
- * start of the radiotap header **. There is no guarantee
+ * Note that these alignments are relative to the start
+ * of the radiotap header. There is no guarantee
* that the radiotap header itself is aligned on any
* kind of boundary.
*
- * the above is why get_unaligned() is used to dereference
- * multibyte elements from the radiotap area
+ * The above is why get_unaligned() is used to dereference
+ * multibyte elements from the radiotap area.
*/
- pad = (((ulong)iterator->arg) -
- ((ulong)iterator->rtheader)) &
- ((rt_sizes[iterator->arg_index] >> 4) - 1);
+ pad = ((unsigned long)iterator->_arg -
+ (unsigned long)iterator->_rtheader) & (align - 1);
if (pad)
- iterator->arg +=
- (rt_sizes[iterator->arg_index] >> 4) - pad;
+ iterator->_arg += align - pad;
/*
* this is what we will return to user, but we need to
* move on first so next call has something fresh to test
*/
- iterator->this_arg_index = iterator->arg_index;
- iterator->this_arg = iterator->arg;
- hit = 1;
+ iterator->this_arg_index = iterator->_arg_index;
+ iterator->this_arg = iterator->_arg;
+ iterator->this_arg_size = size;
/* internally move on the size of this arg */
- iterator->arg += rt_sizes[iterator->arg_index] & 0x0f;
+ iterator->_arg += size;
/*
* check for insanity where we are given a bitmap that
* max_length on the last arg, never exceeding it.
*/
- if (((ulong)iterator->arg - (ulong)iterator->rtheader) >
- iterator->max_length)
+ if ((unsigned long)iterator->_arg -
+ (unsigned long)iterator->_rtheader >
+ (unsigned long)iterator->_max_length)
return -EINVAL;
- next_entry:
- iterator->arg_index++;
- if (unlikely((iterator->arg_index & 31) == 0)) {
- /* completed current u32 bitmap */
- if (iterator->bitmap_shifter & 1) {
- /* b31 was set, there is more */
- /* move to next u32 bitmap */
- iterator->bitmap_shifter =
- get_unaligned_le32(iterator->next_bitmap);
- iterator->next_bitmap++;
- } else
- /* no more bitmaps: end */
- iterator->arg_index = sizeof(rt_sizes);
- } else /* just try the next bit */
- iterator->bitmap_shifter >>= 1;
+ /* these special ones are valid in each bitmap word */
+ switch (iterator->_arg_index % 32) {
+ case IEEE80211_RADIOTAP_VENDOR_NAMESPACE:
+ iterator->_bitmap_shifter >>= 1;
+ iterator->_arg_index++;
+
+ iterator->_reset_on_ext = 1;
+
+ vnslen = get_unaligned_le16(iterator->this_arg + 4);
+ iterator->_next_ns_data = iterator->_arg + vnslen;
+ oui = (*iterator->this_arg << 16) |
+ (*(iterator->this_arg + 1) << 8) |
+ *(iterator->this_arg + 2);
+ subns = *(iterator->this_arg + 3);
+
+ find_ns(iterator, oui, subns);
+
+ iterator->is_radiotap_ns = 0;
+ /* allow parsers to show this information */
+ iterator->this_arg_index =
+ IEEE80211_RADIOTAP_VENDOR_NAMESPACE;
+ iterator->this_arg_size += vnslen;
+ if ((unsigned long)iterator->this_arg +
+ iterator->this_arg_size -
+ (unsigned long)iterator->_rtheader >
+ (unsigned long)(unsigned long)iterator->_max_length)
+ return -EINVAL;
+ hit = 1;
+ break;
+ case IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE:
+ iterator->_bitmap_shifter >>= 1;
+ iterator->_arg_index++;
+
+ iterator->_reset_on_ext = 1;
+ iterator->current_namespace = &radiotap_ns;
+ iterator->is_radiotap_ns = 1;
+ break;
+ case IEEE80211_RADIOTAP_EXT:
+ /*
+ * bit 31 was set, there is more
+ * -- move to next u32 bitmap
+ */
+ iterator->_bitmap_shifter =
+ get_unaligned_le32(iterator->_next_bitmap);
+ iterator->_next_bitmap++;
+ if (iterator->_reset_on_ext)
+ iterator->_arg_index = 0;
+ else
+ iterator->_arg_index++;
+ iterator->_reset_on_ext = 0;
+ break;
+ default:
+ /* we've got a hit! */
+ hit = 1;
+ next_entry:
+ iterator->_bitmap_shifter >>= 1;
+ iterator->_arg_index++;
+ }
/* if we found a valid arg earlier, return it now */
if (hit)
return 0;
}
-
- /* we don't know how to handle any more args, we're done */
- return -ENOENT;
}
EXPORT_SYMBOL(ieee80211_radiotap_iterator_next);
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff