diff options
| -rw-r--r-- | Documentation/networking/ethtool-netlink.rst | 84 | ||||
| -rw-r--r-- | include/uapi/linux/ethtool_netlink.h | 35 | ||||
| -rw-r--r-- | net/ethtool/Makefile | 2 | ||||
| -rw-r--r-- | net/ethtool/bitset.c | 735 | ||||
| -rw-r--r-- | net/ethtool/bitset.h | 28 |
5 files changed, 883 insertions, 1 deletions
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst index 9448442ad293..7797f1237472 100644 --- a/Documentation/networking/ethtool-netlink.rst +++ b/Documentation/networking/ethtool-netlink.rst @@ -76,6 +76,90 @@ of the flag should be interpreted the way the client expects. A client must not set flags it does not understand. +Bit sets +======== + +For short bitmaps of (reasonably) fixed length, standard ``NLA_BITFIELD32`` +type is used. For arbitrary length bitmaps, ethtool netlink uses a nested +attribute with contents of one of two forms: compact (two binary bitmaps +representing bit values and mask of affected bits) and bit-by-bit (list of +bits identified by either index or name). + +Verbose (bit-by-bit) bitsets allow sending symbolic names for bits together +with their values which saves a round trip (when the bitset is passed in a +request) or at least a second request (when the bitset is in a reply). This is +useful for one shot applications like traditional ethtool command. On the +other hand, long running applications like ethtool monitor (displaying +notifications) or network management daemons may prefer fetching the names +only once and using compact form to save message size. Notifications from +ethtool netlink interface always use compact form for bitsets. + +A bitset can represent either a value/mask pair (``ETHTOOL_A_BITSET_NOMASK`` +not set) or a single bitmap (``ETHTOOL_A_BITSET_NOMASK`` set). In requests +modifying a bitmap, the former changes the bit set in mask to values set in +value and preserves the rest; the latter sets the bits set in the bitmap and +clears the rest. + +Compact form: nested (bitset) atrribute contents: + + ============================ ====== ============================ + ``ETHTOOL_A_BITSET_NOMASK`` flag no mask, only a list + ``ETHTOOL_A_BITSET_SIZE`` u32 number of significant bits + ``ETHTOOL_A_BITSET_VALUE`` binary bitmap of bit values + ``ETHTOOL_A_BITSET_MASK`` binary bitmap of valid bits + ============================ ====== ============================ + +Value and mask must have length at least ``ETHTOOL_A_BITSET_SIZE`` bits +rounded up to a multiple of 32 bits. They consist of 32-bit words in host byte +order, words ordered from least significant to most significant (i.e. the same +way as bitmaps are passed with ioctl interface). + +For compact form, ``ETHTOOL_A_BITSET_SIZE`` and ``ETHTOOL_A_BITSET_VALUE`` are +mandatory. ``ETHTOOL_A_BITSET_MASK`` attribute is mandatory if +``ETHTOOL_A_BITSET_NOMASK`` is not set (bitset represents a value/mask pair); +if ``ETHTOOL_A_BITSET_NOMASK`` is not set, ``ETHTOOL_A_BITSET_MASK`` is not +allowed (bitset represents a single bitmap. + +Kernel bit set length may differ from userspace length if older application is +used on newer kernel or vice versa. If userspace bitmap is longer, an error is +issued only if the request actually tries to set values of some bits not +recognized by kernel. + +Bit-by-bit form: nested (bitset) attribute contents: + + +------------------------------------+--------+-----------------------------+ + | ``ETHTOOL_A_BITSET_NOMASK`` | flag | no mask, only a list | + +------------------------------------+--------+-----------------------------+ + | ``ETHTOOL_A_BITSET_SIZE`` | u32 | number of significant bits | + +------------------------------------+--------+-----------------------------+ + | ``ETHTOOL_A_BITSET_BITS`` | nested | array of bits | + +-+----------------------------------+--------+-----------------------------+ + | | ``ETHTOOL_A_BITSET_BITS_BIT+`` | nested | one bit | + +-+-+--------------------------------+--------+-----------------------------+ + | | | ``ETHTOOL_A_BITSET_BIT_INDEX`` | u32 | bit index (0 for LSB) | + +-+-+--------------------------------+--------+-----------------------------+ + | | | ``ETHTOOL_A_BITSET_BIT_NAME`` | string | bit name | + +-+-+--------------------------------+--------+-----------------------------+ + | | | ``ETHTOOL_A_BITSET_BIT_VALUE`` | flag | present if bit is set | + +-+-+--------------------------------+--------+-----------------------------+ + +Bit size is optional for bit-by-bit form. ``ETHTOOL_A_BITSET_BITS`` nest can +only contain ``ETHTOOL_A_BITSET_BITS_BIT`` attributes but there can be an +arbitrary number of them. A bit may be identified by its index or by its +name. When used in requests, listed bits are set to 0 or 1 according to +``ETHTOOL_A_BITSET_BIT_VALUE``, the rest is preserved. A request fails if +index exceeds kernel bit length or if name is not recognized. + +When ``ETHTOOL_A_BITSET_NOMASK`` flag is present, bitset is interpreted as +a simple bitmap. ``ETHTOOL_A_BITSET_BIT_VALUE`` attributes are not used in +such case. Such bitset represents a bitmap with listed bits set and the rest +zero. + +In requests, application can use either form. Form used by kernel in reply is +determined by ``ETHTOOL_FLAG_COMPACT_BITSETS`` flag in flags field of request +header. Semantics of value and mask depends on the attribute. + + List of message types ===================== diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h index 82fc3b5f41c9..951203049615 100644 --- a/include/uapi/linux/ethtool_netlink.h +++ b/include/uapi/linux/ethtool_netlink.h @@ -50,6 +50,41 @@ enum { ETHTOOL_A_HEADER_MAX = __ETHTOOL_A_HEADER_CNT - 1 }; +/* bit sets */ + +enum { + ETHTOOL_A_BITSET_BIT_UNSPEC, + ETHTOOL_A_BITSET_BIT_INDEX, /* u32 */ + ETHTOOL_A_BITSET_BIT_NAME, /* string */ + ETHTOOL_A_BITSET_BIT_VALUE, /* flag */ + + /* add new constants above here */ + __ETHTOOL_A_BITSET_BIT_CNT, + ETHTOOL_A_BITSET_BIT_MAX = __ETHTOOL_A_BITSET_BIT_CNT - 1 +}; + +enum { + ETHTOOL_A_BITSET_BITS_UNSPEC, + ETHTOOL_A_BITSET_BITS_BIT, /* nest - _A_BITSET_BIT_* */ + + /* add new constants above here */ + __ETHTOOL_A_BITSET_BITS_CNT, + ETHTOOL_A_BITSET_BITS_MAX = __ETHTOOL_A_BITSET_BITS_CNT - 1 +}; + +enum { + ETHTOOL_A_BITSET_UNSPEC, + ETHTOOL_A_BITSET_NOMASK, /* flag */ + ETHTOOL_A_BITSET_SIZE, /* u32 */ + ETHTOOL_A_BITSET_BITS, /* nest - _A_BITSET_BITS_* */ + ETHTOOL_A_BITSET_VALUE, /* binary */ + ETHTOOL_A_BITSET_MASK, /* binary */ + + /* add new constants above here */ + __ETHTOOL_A_BITSET_CNT, + ETHTOOL_A_BITSET_MAX = __ETHTOOL_A_BITSET_CNT - 1 +}; + /* generic netlink info */ #define ETHTOOL_GENL_NAME "ethtool" #define ETHTOOL_GENL_VERSION 1 diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile index 59d5ee230c29..a7e6c2c85db9 100644 --- a/net/ethtool/Makefile +++ b/net/ethtool/Makefile @@ -4,4 +4,4 @@ obj-y += ioctl.o common.o obj-$(CONFIG_ETHTOOL_NETLINK) += ethtool_nl.o -ethtool_nl-y := netlink.o +ethtool_nl-y := netlink.o bitset.o diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c new file mode 100644 index 000000000000..fce45dac4205 --- /dev/null +++ b/net/ethtool/bitset.c @@ -0,0 +1,735 @@ +// 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_A_BITSET_SIZE] = { .type = NLA_U32 }, + [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; + } + no_mask = tb[ETHTOOL_A_BITSET_NOMASK]; + + 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; +} + +#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) */ diff --git a/net/ethtool/bitset.h b/net/ethtool/bitset.h new file mode 100644 index 000000000000..b8247e34109d --- /dev/null +++ b/net/ethtool/bitset.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef _NET_ETHTOOL_BITSET_H +#define _NET_ETHTOOL_BITSET_H + +typedef const char (*const ethnl_string_array_t)[ETH_GSTRING_LEN]; + +int ethnl_bitset_is_compact(const struct nlattr *bitset, bool *compact); +int ethnl_bitset_size(const unsigned long *val, const unsigned long *mask, + unsigned int nbits, ethnl_string_array_t names, + bool compact); +int ethnl_bitset32_size(const u32 *val, const u32 *mask, unsigned int nbits, + ethnl_string_array_t names, bool 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); +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); +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); +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); + +#endif /* _NET_ETHTOOL_BITSET_H */ |