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linux/net/ethtool/bitset.c

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ethtool: netlink bitset handling The ethtool netlink code uses common framework for passing arbitrary length bit sets to allow future extensions. A bitset can be a list (only one bitmap) or can consist of value and mask pair (used e.g. when client want to modify only some bits). A bitset can use one of two formats: verbose (bit by bit) or compact. Verbose format consists of bitset size (number of bits), list flag and an array of bit nests, telling which bits are part of the list or which bits are in the mask and which of them are to be set. In requests, bits can be identified by index (position) or by name. In replies, kernel provides both index and name. Verbose format is suitable for "one shot" applications like standard ethtool command as it avoids the need to either keep bit names (e.g. link modes) in sync with kernel or having to add an extra roundtrip for string set request (e.g. for private flags). Compact format uses one (list) or two (value/mask) arrays of 32-bit words to store the bitmap(s). It is more suitable for long running applications (ethtool in monitor mode or network management daemons) which can retrieve the names once and then pass only compact bitmaps to save space. Userspace requests can use either format; ETHTOOL_FLAG_COMPACT_BITSETS flag in request header tells kernel which format to use in reply. Notifications always use compact format. As some code uses arrays of unsigned long for internal representation and some arrays of u32 (or even a single u32), two sets of parse/compose helpers are introduced. To avoid code duplication, helpers for unsigned long arrays are implemented as wrappers around helpers for u32 arrays. There are two reasons for this choice: (1) u32 arrays are more frequent in ethtool code and (2) unsigned long array can be always interpreted as an u32 array on little endian 64-bit and all 32-bit architectures while we would need special handling for odd number of u32 words in the opposite direction. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 17:55:28 +03:00
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/ethtool_netlink.h>
#include <linux/bitmap.h>
#include "netlink.h"
#include "bitset.h"
/* Some bitmaps are internally represented as an array of unsigned long, some
* as an array of u32 (some even as single u32 for now). To avoid the need of
* wrappers on caller side, we provide two set of functions: those with "32"
* suffix in their names expect u32 based bitmaps, those without it expect
* unsigned long bitmaps.
*/
static u32 ethnl_lower_bits(unsigned int n)
{
return ~(u32)0 >> (32 - n % 32);
}
static u32 ethnl_upper_bits(unsigned int n)
{
return ~(u32)0 << (n % 32);
}
/**
* ethnl_bitmap32_clear() - Clear u32 based bitmap
* @dst: bitmap to clear
* @start: beginning of the interval
* @end: end of the interval
* @mod: set if bitmap was modified
*
* Clear @nbits bits of a bitmap with indices @start <= i < @end
*/
static void ethnl_bitmap32_clear(u32 *dst, unsigned int start, unsigned int end,
bool *mod)
{
unsigned int start_word = start / 32;
unsigned int end_word = end / 32;
unsigned int i;
u32 mask;
if (end <= start)
return;
if (start % 32) {
mask = ethnl_upper_bits(start);
if (end_word == start_word) {
mask &= ethnl_lower_bits(end);
if (dst[start_word] & mask) {
dst[start_word] &= ~mask;
*mod = true;
}
return;
}
if (dst[start_word] & mask) {
dst[start_word] &= ~mask;
*mod = true;
}
start_word++;
}
for (i = start_word; i < end_word; i++) {
if (dst[i]) {
dst[i] = 0;
*mod = true;
}
}
if (end % 32) {
mask = ethnl_lower_bits(end);
if (dst[end_word] & mask) {
dst[end_word] &= ~mask;
*mod = true;
}
}
}
/**
* ethnl_bitmap32_not_zero() - Check if any bit is set in an interval
* @map: bitmap to test
* @start: beginning of the interval
* @end: end of the interval
*
* Return: true if there is non-zero bit with index @start <= i < @end,
* false if the whole interval is zero
*/
static bool ethnl_bitmap32_not_zero(const u32 *map, unsigned int start,
unsigned int end)
{
unsigned int start_word = start / 32;
unsigned int end_word = end / 32;
u32 mask;
if (end <= start)
return true;
if (start % 32) {
mask = ethnl_upper_bits(start);
if (end_word == start_word) {
mask &= ethnl_lower_bits(end);
return map[start_word] & mask;
}
if (map[start_word] & mask)
return true;
start_word++;
}
if (!memchr_inv(map + start_word, '\0',
(end_word - start_word) * sizeof(u32)))
return true;
if (end % 32 == 0)
return true;
return map[end_word] & ethnl_lower_bits(end);
}
/**
* ethnl_bitmap32_update() - Modify u32 based bitmap according to value/mask
* pair
* @dst: bitmap to update
* @nbits: bit size of the bitmap
* @value: values to set
* @mask: mask of bits to set
* @mod: set to true if bitmap is modified, preserve if not
*
* Set bits in @dst bitmap which are set in @mask to values from @value, leave
* the rest untouched. If destination bitmap was modified, set @mod to true,
* leave as it is if not.
*/
static void ethnl_bitmap32_update(u32 *dst, unsigned int nbits,
const u32 *value, const u32 *mask, bool *mod)
{
while (nbits > 0) {
u32 real_mask = mask ? *mask : ~(u32)0;
u32 new_value;
if (nbits < 32)
real_mask &= ethnl_lower_bits(nbits);
new_value = (*dst & ~real_mask) | (*value & real_mask);
if (new_value != *dst) {
*dst = new_value;
*mod = true;
}
if (nbits <= 32)
break;
dst++;
nbits -= 32;
value++;
if (mask)
mask++;
}
}
static bool ethnl_bitmap32_test_bit(const u32 *map, unsigned int index)
{
return map[index / 32] & (1U << (index % 32));
}
/**
* ethnl_bitset32_size() - Calculate size of bitset nested attribute
* @val: value bitmap (u32 based)
* @mask: mask bitmap (u32 based, optional)
* @nbits: bit length of the bitset
* @names: array of bit names (optional)
* @compact: assume compact format for output
*
* Estimate length of netlink attribute composed by a later call to
* ethnl_put_bitset32() call with the same arguments.
*
* Return: negative error code or attribute length estimate
*/
int ethnl_bitset32_size(const u32 *val, const u32 *mask, unsigned int nbits,
ethnl_string_array_t names, bool compact)
{
unsigned int len = 0;
/* list flag */
if (!mask)
len += nla_total_size(sizeof(u32));
/* size */
len += nla_total_size(sizeof(u32));
if (compact) {
unsigned int nwords = DIV_ROUND_UP(nbits, 32);
/* value, mask */
len += (mask ? 2 : 1) * nla_total_size(nwords * sizeof(u32));
} else {
unsigned int bits_len = 0;
unsigned int bit_len, i;
for (i = 0; i < nbits; i++) {
const char *name = names ? names[i] : NULL;
if (!ethnl_bitmap32_test_bit(mask ?: val, i))
continue;
/* index */
bit_len = nla_total_size(sizeof(u32));
/* name */
if (name)
bit_len += ethnl_strz_size(name);
/* value */
if (mask && ethnl_bitmap32_test_bit(val, i))
bit_len += nla_total_size(0);
/* bit nest */
bits_len += nla_total_size(bit_len);
}
/* bits nest */
len += nla_total_size(bits_len);
}
/* outermost nest */
return nla_total_size(len);
}
/**
* ethnl_put_bitset32() - Put a bitset nest into a message
* @skb: skb with the message
* @attrtype: attribute type for the bitset nest
* @val: value bitmap (u32 based)
* @mask: mask bitmap (u32 based, optional)
* @nbits: bit length of the bitset
* @names: array of bit names (optional)
* @compact: use compact format for the output
*
* Compose a nested attribute representing a bitset. If @mask is null, simple
* bitmap (bit list) is created, if @mask is provided, represent a value/mask
* pair. Bit names are only used in verbose mode and when provided by calller.
*
* Return: 0 on success, negative error value on error
*/
int ethnl_put_bitset32(struct sk_buff *skb, int attrtype, const u32 *val,
const u32 *mask, unsigned int nbits,
ethnl_string_array_t names, bool compact)
{
struct nlattr *nest;
struct nlattr *attr;
nest = nla_nest_start(skb, attrtype);
if (!nest)
return -EMSGSIZE;
if (!mask && nla_put_flag(skb, ETHTOOL_A_BITSET_NOMASK))
goto nla_put_failure;
if (nla_put_u32(skb, ETHTOOL_A_BITSET_SIZE, nbits))
goto nla_put_failure;
if (compact) {
unsigned int nwords = DIV_ROUND_UP(nbits, 32);
unsigned int nbytes = nwords * sizeof(u32);
u32 *dst;
attr = nla_reserve(skb, ETHTOOL_A_BITSET_VALUE, nbytes);
if (!attr)
goto nla_put_failure;
dst = nla_data(attr);
memcpy(dst, val, nbytes);
if (nbits % 32)
dst[nwords - 1] &= ethnl_lower_bits(nbits);
if (mask) {
attr = nla_reserve(skb, ETHTOOL_A_BITSET_MASK, nbytes);
if (!attr)
goto nla_put_failure;
dst = nla_data(attr);
memcpy(dst, mask, nbytes);
if (nbits % 32)
dst[nwords - 1] &= ethnl_lower_bits(nbits);
}
} else {
struct nlattr *bits;
unsigned int i;
bits = nla_nest_start(skb, ETHTOOL_A_BITSET_BITS);
if (!bits)
goto nla_put_failure;
for (i = 0; i < nbits; i++) {
const char *name = names ? names[i] : NULL;
if (!ethnl_bitmap32_test_bit(mask ?: val, i))
continue;
attr = nla_nest_start(skb, ETHTOOL_A_BITSET_BITS_BIT);
if (!attr)
goto nla_put_failure;
if (nla_put_u32(skb, ETHTOOL_A_BITSET_BIT_INDEX, i))
goto nla_put_failure;
if (name &&
ethnl_put_strz(skb, ETHTOOL_A_BITSET_BIT_NAME, name))
goto nla_put_failure;
if (mask && ethnl_bitmap32_test_bit(val, i) &&
nla_put_flag(skb, ETHTOOL_A_BITSET_BIT_VALUE))
goto nla_put_failure;
nla_nest_end(skb, attr);
}
nla_nest_end(skb, bits);
}
nla_nest_end(skb, nest);
return 0;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
static const struct nla_policy bitset_policy[ETHTOOL_A_BITSET_MAX + 1] = {
[ETHTOOL_A_BITSET_UNSPEC] = { .type = NLA_REJECT },
[ETHTOOL_A_BITSET_NOMASK] = { .type = NLA_FLAG },
ethtool: limit bitset size Syzbot reported that ethnl_compact_sanity_checks() can be tricked into reading past the end of ETHTOOL_A_BITSET_VALUE and ETHTOOL_A_BITSET_MASK attributes and even the message by passing a value between (u32)(-31) and (u32)(-1) as ETHTOOL_A_BITSET_SIZE. The problem is that DIV_ROUND_UP(attr_nbits, 32) is 0 for such values so that zero length ETHTOOL_A_BITSET_VALUE will pass the length check but ethnl_bitmap32_not_zero() check would try to access up to 512 MB of attribute "payload". Prevent this overflow byt limiting the bitset size. Technically, compact bitset format would allow bitset sizes up to almost 2^18 (so that the nest size does not exceed U16_MAX) but bitsets used by ethtool are much shorter. S16_MAX, the largest value which can be directly used as an upper limit in policy, should be a reasonable compromise. Fixes: 10b518d4e6dd ("ethtool: netlink bitset handling") Reported-by: syzbot+7fd4ed5b4234ab1fdccd@syzkaller.appspotmail.com Reported-by: syzbot+709b7a64d57978247e44@syzkaller.appspotmail.com Reported-by: syzbot+983cb8fb2d17a7af549d@syzkaller.appspotmail.com Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 22:42:12 +03:00
[ETHTOOL_A_BITSET_SIZE] = NLA_POLICY_MAX(NLA_U32,
ETHNL_MAX_BITSET_SIZE),
ethtool: netlink bitset handling The ethtool netlink code uses common framework for passing arbitrary length bit sets to allow future extensions. A bitset can be a list (only one bitmap) or can consist of value and mask pair (used e.g. when client want to modify only some bits). A bitset can use one of two formats: verbose (bit by bit) or compact. Verbose format consists of bitset size (number of bits), list flag and an array of bit nests, telling which bits are part of the list or which bits are in the mask and which of them are to be set. In requests, bits can be identified by index (position) or by name. In replies, kernel provides both index and name. Verbose format is suitable for "one shot" applications like standard ethtool command as it avoids the need to either keep bit names (e.g. link modes) in sync with kernel or having to add an extra roundtrip for string set request (e.g. for private flags). Compact format uses one (list) or two (value/mask) arrays of 32-bit words to store the bitmap(s). It is more suitable for long running applications (ethtool in monitor mode or network management daemons) which can retrieve the names once and then pass only compact bitmaps to save space. Userspace requests can use either format; ETHTOOL_FLAG_COMPACT_BITSETS flag in request header tells kernel which format to use in reply. Notifications always use compact format. As some code uses arrays of unsigned long for internal representation and some arrays of u32 (or even a single u32), two sets of parse/compose helpers are introduced. To avoid code duplication, helpers for unsigned long arrays are implemented as wrappers around helpers for u32 arrays. There are two reasons for this choice: (1) u32 arrays are more frequent in ethtool code and (2) unsigned long array can be always interpreted as an u32 array on little endian 64-bit and all 32-bit architectures while we would need special handling for odd number of u32 words in the opposite direction. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 17:55:28 +03:00
[ETHTOOL_A_BITSET_BITS] = { .type = NLA_NESTED },
[ETHTOOL_A_BITSET_VALUE] = { .type = NLA_BINARY },
[ETHTOOL_A_BITSET_MASK] = { .type = NLA_BINARY },
};
static const struct nla_policy bit_policy[ETHTOOL_A_BITSET_BIT_MAX + 1] = {
[ETHTOOL_A_BITSET_BIT_UNSPEC] = { .type = NLA_REJECT },
[ETHTOOL_A_BITSET_BIT_INDEX] = { .type = NLA_U32 },
[ETHTOOL_A_BITSET_BIT_NAME] = { .type = NLA_NUL_STRING },
[ETHTOOL_A_BITSET_BIT_VALUE] = { .type = NLA_FLAG },
};
/**
* ethnl_bitset_is_compact() - check if bitset attribute represents a compact
* bitset
* @bitset: nested attribute representing a bitset
* @compact: pointer for return value
*
* Return: 0 on success, negative error code on failure
*/
int ethnl_bitset_is_compact(const struct nlattr *bitset, bool *compact)
{
struct nlattr *tb[ETHTOOL_A_BITSET_MAX + 1];
int ret;
ret = nla_parse_nested(tb, ETHTOOL_A_BITSET_MAX, bitset,
bitset_policy, NULL);
if (ret < 0)
return ret;
if (tb[ETHTOOL_A_BITSET_BITS]) {
if (tb[ETHTOOL_A_BITSET_VALUE] || tb[ETHTOOL_A_BITSET_MASK])
return -EINVAL;
*compact = false;
return 0;
}
if (!tb[ETHTOOL_A_BITSET_SIZE] || !tb[ETHTOOL_A_BITSET_VALUE])
return -EINVAL;
*compact = true;
return 0;
}
/**
* ethnl_name_to_idx() - look up string index for a name
* @names: array of ETH_GSTRING_LEN sized strings
* @n_names: number of strings in the array
* @name: name to look up
*
* Return: index of the string if found, -ENOENT if not found
*/
static int ethnl_name_to_idx(ethnl_string_array_t names, unsigned int n_names,
const char *name)
{
unsigned int i;
if (!names)
return -ENOENT;
for (i = 0; i < n_names; i++) {
/* names[i] may not be null terminated */
if (!strncmp(names[i], name, ETH_GSTRING_LEN) &&
strlen(name) <= ETH_GSTRING_LEN)
return i;
}
return -ENOENT;
}
static int ethnl_parse_bit(unsigned int *index, bool *val, unsigned int nbits,
const struct nlattr *bit_attr, bool no_mask,
ethnl_string_array_t names,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[ETHTOOL_A_BITSET_BIT_MAX + 1];
int ret, idx;
ret = nla_parse_nested(tb, ETHTOOL_A_BITSET_BIT_MAX, bit_attr,
bit_policy, extack);
if (ret < 0)
return ret;
if (tb[ETHTOOL_A_BITSET_BIT_INDEX]) {
const char *name;
idx = nla_get_u32(tb[ETHTOOL_A_BITSET_BIT_INDEX]);
if (idx >= nbits) {
NL_SET_ERR_MSG_ATTR(extack,
tb[ETHTOOL_A_BITSET_BIT_INDEX],
"bit index too high");
return -EOPNOTSUPP;
}
name = names ? names[idx] : NULL;
if (tb[ETHTOOL_A_BITSET_BIT_NAME] && name &&
strncmp(nla_data(tb[ETHTOOL_A_BITSET_BIT_NAME]), name,
nla_len(tb[ETHTOOL_A_BITSET_BIT_NAME]))) {
NL_SET_ERR_MSG_ATTR(extack, bit_attr,
"bit index and name mismatch");
return -EINVAL;
}
} else if (tb[ETHTOOL_A_BITSET_BIT_NAME]) {
idx = ethnl_name_to_idx(names, nbits,
nla_data(tb[ETHTOOL_A_BITSET_BIT_NAME]));
if (idx < 0) {
NL_SET_ERR_MSG_ATTR(extack,
tb[ETHTOOL_A_BITSET_BIT_NAME],
"bit name not found");
return -EOPNOTSUPP;
}
} else {
NL_SET_ERR_MSG_ATTR(extack, bit_attr,
"neither bit index nor name specified");
return -EINVAL;
}
*index = idx;
*val = no_mask || tb[ETHTOOL_A_BITSET_BIT_VALUE];
return 0;
}
static int
ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits,
const struct nlattr *attr, struct nlattr **tb,
ethnl_string_array_t names,
struct netlink_ext_ack *extack, bool *mod)
{
struct nlattr *bit_attr;
bool no_mask;
int rem;
int ret;
if (tb[ETHTOOL_A_BITSET_VALUE]) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
"value only allowed in compact bitset");
return -EINVAL;
}
if (tb[ETHTOOL_A_BITSET_MASK]) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
"mask only allowed in compact bitset");
return -EINVAL;
}
ethtool: fix application of verbose no_mask bitset A bitset without mask in a _SET request means we want exactly the bits in the bitset to be set. This works correctly for compact format but when verbose format is parsed, ethnl_update_bitset32_verbose() only sets the bits present in the request bitset but does not clear the rest. This can cause incorrect results like lion:~ # ethtool eth0 | grep Wake Supports Wake-on: pumbg Wake-on: g lion:~ # ethtool -s eth0 wol u lion:~ # ethtool eth0 | grep Wake Supports Wake-on: pumbg Wake-on: ug when the second ethtool command issues request ETHTOOL_MSG_WOL_SET ETHTOOL_A_WOL_HEADER ETHTOOL_A_HEADER_DEV_NAME = "eth0" ETHTOOL_A_WOL_MODES ETHTOOL_A_BITSET_NOMASK ETHTOOL_A_BITSET_BITS ETHTOOL_A_BITSET_BITS_BIT ETHTOOL_BITSET_BIT_INDEX = 1 Fix the logic by clearing the whole target bitmap before we start iterating through the request bits. Fixes: 10b518d4e6dd ("ethtool: netlink bitset handling") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-15 03:55:53 +03:00
ethtool: netlink bitset handling The ethtool netlink code uses common framework for passing arbitrary length bit sets to allow future extensions. A bitset can be a list (only one bitmap) or can consist of value and mask pair (used e.g. when client want to modify only some bits). A bitset can use one of two formats: verbose (bit by bit) or compact. Verbose format consists of bitset size (number of bits), list flag and an array of bit nests, telling which bits are part of the list or which bits are in the mask and which of them are to be set. In requests, bits can be identified by index (position) or by name. In replies, kernel provides both index and name. Verbose format is suitable for "one shot" applications like standard ethtool command as it avoids the need to either keep bit names (e.g. link modes) in sync with kernel or having to add an extra roundtrip for string set request (e.g. for private flags). Compact format uses one (list) or two (value/mask) arrays of 32-bit words to store the bitmap(s). It is more suitable for long running applications (ethtool in monitor mode or network management daemons) which can retrieve the names once and then pass only compact bitmaps to save space. Userspace requests can use either format; ETHTOOL_FLAG_COMPACT_BITSETS flag in request header tells kernel which format to use in reply. Notifications always use compact format. As some code uses arrays of unsigned long for internal representation and some arrays of u32 (or even a single u32), two sets of parse/compose helpers are introduced. To avoid code duplication, helpers for unsigned long arrays are implemented as wrappers around helpers for u32 arrays. There are two reasons for this choice: (1) u32 arrays are more frequent in ethtool code and (2) unsigned long array can be always interpreted as an u32 array on little endian 64-bit and all 32-bit architectures while we would need special handling for odd number of u32 words in the opposite direction. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 17:55:28 +03:00
no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
ethtool: fix application of verbose no_mask bitset A bitset without mask in a _SET request means we want exactly the bits in the bitset to be set. This works correctly for compact format but when verbose format is parsed, ethnl_update_bitset32_verbose() only sets the bits present in the request bitset but does not clear the rest. This can cause incorrect results like lion:~ # ethtool eth0 | grep Wake Supports Wake-on: pumbg Wake-on: g lion:~ # ethtool -s eth0 wol u lion:~ # ethtool eth0 | grep Wake Supports Wake-on: pumbg Wake-on: ug when the second ethtool command issues request ETHTOOL_MSG_WOL_SET ETHTOOL_A_WOL_HEADER ETHTOOL_A_HEADER_DEV_NAME = "eth0" ETHTOOL_A_WOL_MODES ETHTOOL_A_BITSET_NOMASK ETHTOOL_A_BITSET_BITS ETHTOOL_A_BITSET_BITS_BIT ETHTOOL_BITSET_BIT_INDEX = 1 Fix the logic by clearing the whole target bitmap before we start iterating through the request bits. Fixes: 10b518d4e6dd ("ethtool: netlink bitset handling") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-15 03:55:53 +03:00
if (no_mask)
ethnl_bitmap32_clear(bitmap, 0, nbits, mod);
ethtool: netlink bitset handling The ethtool netlink code uses common framework for passing arbitrary length bit sets to allow future extensions. A bitset can be a list (only one bitmap) or can consist of value and mask pair (used e.g. when client want to modify only some bits). A bitset can use one of two formats: verbose (bit by bit) or compact. Verbose format consists of bitset size (number of bits), list flag and an array of bit nests, telling which bits are part of the list or which bits are in the mask and which of them are to be set. In requests, bits can be identified by index (position) or by name. In replies, kernel provides both index and name. Verbose format is suitable for "one shot" applications like standard ethtool command as it avoids the need to either keep bit names (e.g. link modes) in sync with kernel or having to add an extra roundtrip for string set request (e.g. for private flags). Compact format uses one (list) or two (value/mask) arrays of 32-bit words to store the bitmap(s). It is more suitable for long running applications (ethtool in monitor mode or network management daemons) which can retrieve the names once and then pass only compact bitmaps to save space. Userspace requests can use either format; ETHTOOL_FLAG_COMPACT_BITSETS flag in request header tells kernel which format to use in reply. Notifications always use compact format. As some code uses arrays of unsigned long for internal representation and some arrays of u32 (or even a single u32), two sets of parse/compose helpers are introduced. To avoid code duplication, helpers for unsigned long arrays are implemented as wrappers around helpers for u32 arrays. There are two reasons for this choice: (1) u32 arrays are more frequent in ethtool code and (2) unsigned long array can be always interpreted as an u32 array on little endian 64-bit and all 32-bit architectures while we would need special handling for odd number of u32 words in the opposite direction. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 17:55:28 +03:00
nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) {
bool old_val, new_val;
unsigned int idx;
if (nla_type(bit_attr) != ETHTOOL_A_BITSET_BITS_BIT) {
NL_SET_ERR_MSG_ATTR(extack, bit_attr,
"only ETHTOOL_A_BITSET_BITS_BIT allowed in ETHTOOL_A_BITSET_BITS");
return -EINVAL;
}
ret = ethnl_parse_bit(&idx, &new_val, nbits, bit_attr, no_mask,
names, extack);
if (ret < 0)
return ret;
old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32));
if (new_val != old_val) {
if (new_val)
bitmap[idx / 32] |= ((u32)1 << (idx % 32));
else
bitmap[idx / 32] &= ~((u32)1 << (idx % 32));
*mod = true;
}
}
return 0;
}
static int ethnl_compact_sanity_checks(unsigned int nbits,
const struct nlattr *nest,
struct nlattr **tb,
struct netlink_ext_ack *extack)
{
bool no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
unsigned int attr_nbits, attr_nwords;
const struct nlattr *test_attr;
if (no_mask && tb[ETHTOOL_A_BITSET_MASK]) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
"mask not allowed in list bitset");
return -EINVAL;
}
if (!tb[ETHTOOL_A_BITSET_SIZE]) {
NL_SET_ERR_MSG_ATTR(extack, nest,
"missing size in compact bitset");
return -EINVAL;
}
if (!tb[ETHTOOL_A_BITSET_VALUE]) {
NL_SET_ERR_MSG_ATTR(extack, nest,
"missing value in compact bitset");
return -EINVAL;
}
if (!no_mask && !tb[ETHTOOL_A_BITSET_MASK]) {
NL_SET_ERR_MSG_ATTR(extack, nest,
"missing mask in compact nonlist bitset");
return -EINVAL;
}
attr_nbits = nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]);
attr_nwords = DIV_ROUND_UP(attr_nbits, 32);
if (nla_len(tb[ETHTOOL_A_BITSET_VALUE]) != attr_nwords * sizeof(u32)) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
"bitset value length does not match size");
return -EINVAL;
}
if (tb[ETHTOOL_A_BITSET_MASK] &&
nla_len(tb[ETHTOOL_A_BITSET_MASK]) != attr_nwords * sizeof(u32)) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
"bitset mask length does not match size");
return -EINVAL;
}
if (attr_nbits <= nbits)
return 0;
test_attr = no_mask ? tb[ETHTOOL_A_BITSET_VALUE] :
tb[ETHTOOL_A_BITSET_MASK];
if (ethnl_bitmap32_not_zero(nla_data(test_attr), nbits, attr_nbits)) {
NL_SET_ERR_MSG_ATTR(extack, test_attr,
"cannot modify bits past kernel bitset size");
return -EINVAL;
}
return 0;
}
/**
* ethnl_update_bitset32() - Apply a bitset nest to a u32 based bitmap
* @bitmap: bitmap to update
* @nbits: size of the updated bitmap in bits
* @attr: nest attribute to parse and apply
* @names: array of bit names; may be null for compact format
* @extack: extack for error reporting
* @mod: set this to true if bitmap is modified, leave as it is if not
*
* Apply bitset netsted attribute to a bitmap. If the attribute represents
* a bit list, @bitmap is set to its contents; otherwise, bits in mask are
* set to values from value. Bitmaps in the attribute may be longer than
* @nbits but the message must not request modifying any bits past @nbits.
*
* Return: negative error code on failure, 0 on success
*/
int ethnl_update_bitset32(u32 *bitmap, unsigned int nbits,
const struct nlattr *attr, ethnl_string_array_t names,
struct netlink_ext_ack *extack, bool *mod)
{
struct nlattr *tb[ETHTOOL_A_BITSET_MAX + 1];
unsigned int change_bits;
bool no_mask;
int ret;
if (!attr)
return 0;
ret = nla_parse_nested(tb, ETHTOOL_A_BITSET_MAX, attr, bitset_policy,
extack);
if (ret < 0)
return ret;
if (tb[ETHTOOL_A_BITSET_BITS])
return ethnl_update_bitset32_verbose(bitmap, nbits, attr, tb,
names, extack, mod);
ret = ethnl_compact_sanity_checks(nbits, attr, tb, extack);
if (ret < 0)
return ret;
no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
change_bits = min_t(unsigned int,
nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]), nbits);
ethnl_bitmap32_update(bitmap, change_bits,
nla_data(tb[ETHTOOL_A_BITSET_VALUE]),
no_mask ? NULL :
nla_data(tb[ETHTOOL_A_BITSET_MASK]),
mod);
if (no_mask && change_bits < nbits)
ethnl_bitmap32_clear(bitmap, change_bits, nbits, mod);
return 0;
}
ethtool: add ethnl_parse_bitset() helper Unlike other SET type commands, modifying netdev features is required to provide a reply telling userspace what was actually changed, compared to what was requested. For that purpose, the "modified" flag provided by ethnl_update_bitset() is not sufficient, we need full information which bits were requested to change. Therefore provide ethnl_parse_bitset() returning effective value and mask bitmaps equivalent to the contents of a bitset nested attribute. v2: use non-atomic __set_bit() (suggested by David Miller) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-12 23:07:53 +03:00
/**
* ethnl_parse_bitset() - Compute effective value and mask from bitset nest
* @val: unsigned long based bitmap to put value into
* @mask: unsigned long based bitmap to put mask into
* @nbits: size of @val and @mask bitmaps
* @attr: nest attribute to parse and apply
* @names: array of bit names; may be null for compact format
* @extack: extack for error reporting
*
* Provide @nbits size long bitmaps for value and mask so that
* x = (val & mask) | (x & ~mask) would modify any @nbits sized bitmap x
* the same way ethnl_update_bitset() with the same bitset attribute would.
*
* Return: negative error code on failure, 0 on success
*/
int ethnl_parse_bitset(unsigned long *val, unsigned long *mask,
unsigned int nbits, const struct nlattr *attr,
ethnl_string_array_t names,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[ETHTOOL_A_BITSET_MAX + 1];
const struct nlattr *bit_attr;
bool no_mask;
int rem;
int ret;
if (!attr)
return 0;
ret = nla_parse_nested(tb, ETHTOOL_A_BITSET_MAX, attr, bitset_policy,
extack);
if (ret < 0)
return ret;
no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
if (!tb[ETHTOOL_A_BITSET_BITS]) {
unsigned int change_bits;
ret = ethnl_compact_sanity_checks(nbits, attr, tb, extack);
if (ret < 0)
return ret;
change_bits = nla_get_u32(tb[ETHTOOL_A_BITSET_SIZE]);
bitmap_from_arr32(val, nla_data(tb[ETHTOOL_A_BITSET_VALUE]),
change_bits);
if (change_bits < nbits)
bitmap_clear(val, change_bits, nbits - change_bits);
if (no_mask) {
bitmap_fill(mask, nbits);
} else {
bitmap_from_arr32(mask,
nla_data(tb[ETHTOOL_A_BITSET_MASK]),
change_bits);
if (change_bits < nbits)
bitmap_clear(mask, change_bits,
nbits - change_bits);
}
return 0;
}
if (tb[ETHTOOL_A_BITSET_VALUE]) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_VALUE],
"value only allowed in compact bitset");
return -EINVAL;
}
if (tb[ETHTOOL_A_BITSET_MASK]) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_BITSET_MASK],
"mask only allowed in compact bitset");
return -EINVAL;
}
bitmap_zero(val, nbits);
if (no_mask)
bitmap_fill(mask, nbits);
else
bitmap_zero(mask, nbits);
nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) {
unsigned int idx;
bool bit_val;
ret = ethnl_parse_bit(&idx, &bit_val, nbits, bit_attr, no_mask,
names, extack);
if (ret < 0)
return ret;
if (bit_val)
__set_bit(idx, val);
if (!no_mask)
__set_bit(idx, mask);
}
return 0;
}
ethtool: netlink bitset handling The ethtool netlink code uses common framework for passing arbitrary length bit sets to allow future extensions. A bitset can be a list (only one bitmap) or can consist of value and mask pair (used e.g. when client want to modify only some bits). A bitset can use one of two formats: verbose (bit by bit) or compact. Verbose format consists of bitset size (number of bits), list flag and an array of bit nests, telling which bits are part of the list or which bits are in the mask and which of them are to be set. In requests, bits can be identified by index (position) or by name. In replies, kernel provides both index and name. Verbose format is suitable for "one shot" applications like standard ethtool command as it avoids the need to either keep bit names (e.g. link modes) in sync with kernel or having to add an extra roundtrip for string set request (e.g. for private flags). Compact format uses one (list) or two (value/mask) arrays of 32-bit words to store the bitmap(s). It is more suitable for long running applications (ethtool in monitor mode or network management daemons) which can retrieve the names once and then pass only compact bitmaps to save space. Userspace requests can use either format; ETHTOOL_FLAG_COMPACT_BITSETS flag in request header tells kernel which format to use in reply. Notifications always use compact format. As some code uses arrays of unsigned long for internal representation and some arrays of u32 (or even a single u32), two sets of parse/compose helpers are introduced. To avoid code duplication, helpers for unsigned long arrays are implemented as wrappers around helpers for u32 arrays. There are two reasons for this choice: (1) u32 arrays are more frequent in ethtool code and (2) unsigned long array can be always interpreted as an u32 array on little endian 64-bit and all 32-bit architectures while we would need special handling for odd number of u32 words in the opposite direction. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 17:55:28 +03:00
#if BITS_PER_LONG == 64 && defined(__BIG_ENDIAN)
/* 64-bit big endian architectures are the only case when u32 based bitmaps
* and unsigned long based bitmaps have different memory layout so that we
* cannot simply cast the latter to the former and need actual wrappers
* converting the latter to the former.
*
* To reduce the number of slab allocations, the wrappers use fixed size local
* variables for bitmaps up to ETHNL_SMALL_BITMAP_BITS bits which is the
* majority of bitmaps used by ethtool.
*/
#define ETHNL_SMALL_BITMAP_BITS 128
#define ETHNL_SMALL_BITMAP_WORDS DIV_ROUND_UP(ETHNL_SMALL_BITMAP_BITS, 32)
int ethnl_bitset_size(const unsigned long *val, const unsigned long *mask,
unsigned int nbits, ethnl_string_array_t names,
bool compact)
{
u32 small_mask32[ETHNL_SMALL_BITMAP_WORDS];
u32 small_val32[ETHNL_SMALL_BITMAP_WORDS];
u32 *mask32;
u32 *val32;
int ret;
if (nbits > ETHNL_SMALL_BITMAP_BITS) {
unsigned int nwords = DIV_ROUND_UP(nbits, 32);
val32 = kmalloc_array(2 * nwords, sizeof(u32), GFP_KERNEL);
if (!val32)
return -ENOMEM;
mask32 = val32 + nwords;
} else {
val32 = small_val32;
mask32 = small_mask32;
}
bitmap_to_arr32(val32, val, nbits);
if (mask)
bitmap_to_arr32(mask32, mask, nbits);
else
mask32 = NULL;
ret = ethnl_bitset32_size(val32, mask32, nbits, names, compact);
if (nbits > ETHNL_SMALL_BITMAP_BITS)
kfree(val32);
return ret;
}
int ethnl_put_bitset(struct sk_buff *skb, int attrtype,
const unsigned long *val, const unsigned long *mask,
unsigned int nbits, ethnl_string_array_t names,
bool compact)
{
u32 small_mask32[ETHNL_SMALL_BITMAP_WORDS];
u32 small_val32[ETHNL_SMALL_BITMAP_WORDS];
u32 *mask32;
u32 *val32;
int ret;
if (nbits > ETHNL_SMALL_BITMAP_BITS) {
unsigned int nwords = DIV_ROUND_UP(nbits, 32);
val32 = kmalloc_array(2 * nwords, sizeof(u32), GFP_KERNEL);
if (!val32)
return -ENOMEM;
mask32 = val32 + nwords;
} else {
val32 = small_val32;
mask32 = small_mask32;
}
bitmap_to_arr32(val32, val, nbits);
if (mask)
bitmap_to_arr32(mask32, mask, nbits);
else
mask32 = NULL;
ret = ethnl_put_bitset32(skb, attrtype, val32, mask32, nbits, names,
compact);
if (nbits > ETHNL_SMALL_BITMAP_BITS)
kfree(val32);
return ret;
}
int ethnl_update_bitset(unsigned long *bitmap, unsigned int nbits,
const struct nlattr *attr, ethnl_string_array_t names,
struct netlink_ext_ack *extack, bool *mod)
{
u32 small_bitmap32[ETHNL_SMALL_BITMAP_WORDS];
u32 *bitmap32 = small_bitmap32;
bool u32_mod = false;
int ret;
if (nbits > ETHNL_SMALL_BITMAP_BITS) {
unsigned int dst_words = DIV_ROUND_UP(nbits, 32);
bitmap32 = kmalloc_array(dst_words, sizeof(u32), GFP_KERNEL);
if (!bitmap32)
return -ENOMEM;
}
bitmap_to_arr32(bitmap32, bitmap, nbits);
ret = ethnl_update_bitset32(bitmap32, nbits, attr, names, extack,
&u32_mod);
if (u32_mod) {
bitmap_from_arr32(bitmap, bitmap32, nbits);
*mod = true;
}
if (nbits > ETHNL_SMALL_BITMAP_BITS)
kfree(bitmap32);
return ret;
}
#else
/* On little endian 64-bit and all 32-bit architectures, an unsigned long
* based bitmap can be interpreted as u32 based one using a simple cast.
*/
int ethnl_bitset_size(const unsigned long *val, const unsigned long *mask,
unsigned int nbits, ethnl_string_array_t names,
bool compact)
{
return ethnl_bitset32_size((const u32 *)val, (const u32 *)mask, nbits,
names, compact);
}
int ethnl_put_bitset(struct sk_buff *skb, int attrtype,
const unsigned long *val, const unsigned long *mask,
unsigned int nbits, ethnl_string_array_t names,
bool compact)
{
return ethnl_put_bitset32(skb, attrtype, (const u32 *)val,
(const u32 *)mask, nbits, names, compact);
}
int ethnl_update_bitset(unsigned long *bitmap, unsigned int nbits,
const struct nlattr *attr, ethnl_string_array_t names,
struct netlink_ext_ack *extack, bool *mod)
{
return ethnl_update_bitset32((u32 *)bitmap, nbits, attr, names, extack,
mod);
}
#endif /* BITS_PER_LONG == 64 && defined(__BIG_ENDIAN) */
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