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author | Michal Kubecek <mkubecek@suse.cz> | 2020-03-12 21:07:53 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2020-03-12 15:32:32 -0700 |
commit | 88db6d1e4f6222d22c1c4b4d4d7166cfa9d2fe0e (patch) | |
tree | 8857cf131cdaf9990495ec4010d240da360df15b /net/ethtool/bitset.c | |
parent | 0524399d4612f5af38b8383680dde4df4bc4eea2 (diff) | |
download | linux-88db6d1e4f6222d22c1c4b4d4d7166cfa9d2fe0e.tar.gz linux-88db6d1e4f6222d22c1c4b4d4d7166cfa9d2fe0e.tar.bz2 linux-88db6d1e4f6222d22c1c4b4d4d7166cfa9d2fe0e.zip |
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>
Diffstat (limited to 'net/ethtool/bitset.c')
-rw-r--r-- | net/ethtool/bitset.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c index ef9197541cb3..dae7402eaca3 100644 --- a/net/ethtool/bitset.c +++ b/net/ethtool/bitset.c @@ -588,6 +588,100 @@ int ethnl_update_bitset32(u32 *bitmap, unsigned int nbits, return 0; } +/** + * 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; +} + #if BITS_PER_LONG == 64 && defined(__BIG_ENDIAN) /* 64-bit big endian architectures are the only case when u32 based bitmaps |