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374d345d9b
We currently push everyone to use padding to align 64b values in netlink. Un-padded nla_put_u64() doesn't even exist any more. The story behind this possibly start with this thread: https://lore.kernel.org/netdev/20121204.130914.1457976839967676240.davem@davemloft.net/ where DaveM was concerned about the alignment of a structure containing 64b stats. If user space tries to access such struct directly: struct some_stats *stats = nla_data(attr); printf("A: %llu", stats->a); lack of alignment may become problematic for some architectures. These days we most often put every single member in a separate attribute, meaning that the code above would use a helper like nla_get_u64(), which can deal with alignment internally. Even for arches which don't have good unaligned access - access aligned to 4B should be pretty efficient. Kernel and well known libraries deal with unaligned input already. Padded 64b is quite space-inefficient (64b + pad means at worst 16B per attr vs 32b which takes 8B). It is also more typing: if (nla_put_u64_pad(rsp, NETDEV_A_SOMETHING_SOMETHING, value, NETDEV_A_SOMETHING_PAD)) Create a new attribute type which will use 32 bits at netlink level if value is small enough (probably most of the time?), and (4B-aligned) 64 bits otherwise. Kernel API is just: if (nla_put_uint(rsp, NETDEV_A_SOMETHING_SOMETHING, value)) Calling this new type "just" sint / uint with no specific size will hopefully also make people more comfortable with using it. Currently telling people "don't use u8, you may need the bits, and netlink will round up to 4B, anyway" is the #1 comment we give to newcomers. In terms of netlink layout it looks like this: 0 4 8 12 16 32b: [nlattr][ u32 ] 64b: [ pad ][nlattr][ u64 ] uint(32) [nlattr][ u32 ] uint(64) [nlattr][ u64 ] Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1166 lines
28 KiB
C
1166 lines
28 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* NETLINK Netlink attributes
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*
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* Authors: Thomas Graf <tgraf@suug.ch>
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* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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*/
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#include <linux/export.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/jiffies.h>
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#include <linux/nospec.h>
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#include <linux/skbuff.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <net/netlink.h>
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/* For these data types, attribute length should be exactly the given
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* size. However, to maintain compatibility with broken commands, if the
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* attribute length does not match the expected size a warning is emitted
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* to the user that the command is sending invalid data and needs to be fixed.
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*/
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static const u8 nla_attr_len[NLA_TYPE_MAX+1] = {
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[NLA_U8] = sizeof(u8),
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[NLA_U16] = sizeof(u16),
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[NLA_U32] = sizeof(u32),
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[NLA_U64] = sizeof(u64),
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[NLA_S8] = sizeof(s8),
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[NLA_S16] = sizeof(s16),
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[NLA_S32] = sizeof(s32),
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[NLA_S64] = sizeof(s64),
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};
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static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
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[NLA_U8] = sizeof(u8),
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[NLA_U16] = sizeof(u16),
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[NLA_U32] = sizeof(u32),
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[NLA_U64] = sizeof(u64),
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[NLA_MSECS] = sizeof(u64),
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[NLA_NESTED] = NLA_HDRLEN,
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[NLA_S8] = sizeof(s8),
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[NLA_S16] = sizeof(s16),
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[NLA_S32] = sizeof(s32),
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[NLA_S64] = sizeof(s64),
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};
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/*
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* Nested policies might refer back to the original
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* policy in some cases, and userspace could try to
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* abuse that and recurse by nesting in the right
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* ways. Limit recursion to avoid this problem.
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*/
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#define MAX_POLICY_RECURSION_DEPTH 10
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static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype,
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const struct nla_policy *policy,
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unsigned int validate,
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struct netlink_ext_ack *extack,
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struct nlattr **tb, unsigned int depth);
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static int validate_nla_bitfield32(const struct nlattr *nla,
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const u32 valid_flags_mask)
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{
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const struct nla_bitfield32 *bf = nla_data(nla);
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if (!valid_flags_mask)
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return -EINVAL;
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/*disallow invalid bit selector */
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if (bf->selector & ~valid_flags_mask)
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return -EINVAL;
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/*disallow invalid bit values */
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if (bf->value & ~valid_flags_mask)
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return -EINVAL;
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/*disallow valid bit values that are not selected*/
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if (bf->value & ~bf->selector)
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return -EINVAL;
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return 0;
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}
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static int nla_validate_array(const struct nlattr *head, int len, int maxtype,
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const struct nla_policy *policy,
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struct netlink_ext_ack *extack,
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unsigned int validate, unsigned int depth)
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{
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const struct nlattr *entry;
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int rem;
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nla_for_each_attr(entry, head, len, rem) {
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int ret;
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if (nla_len(entry) == 0)
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continue;
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if (nla_len(entry) < NLA_HDRLEN) {
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NL_SET_ERR_MSG_ATTR_POL(extack, entry, policy,
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"Array element too short");
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return -ERANGE;
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}
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ret = __nla_validate_parse(nla_data(entry), nla_len(entry),
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maxtype, policy, validate, extack,
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NULL, depth + 1);
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if (ret < 0)
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return ret;
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}
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return 0;
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}
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void nla_get_range_unsigned(const struct nla_policy *pt,
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struct netlink_range_validation *range)
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{
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WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR &&
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(pt->min < 0 || pt->max < 0));
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range->min = 0;
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switch (pt->type) {
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case NLA_U8:
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range->max = U8_MAX;
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break;
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case NLA_U16:
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case NLA_BE16:
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case NLA_BINARY:
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range->max = U16_MAX;
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break;
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case NLA_U32:
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case NLA_BE32:
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range->max = U32_MAX;
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break;
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case NLA_U64:
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case NLA_UINT:
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case NLA_MSECS:
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range->max = U64_MAX;
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break;
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default:
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WARN_ON_ONCE(1);
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return;
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}
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switch (pt->validation_type) {
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case NLA_VALIDATE_RANGE:
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case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
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range->min = pt->min;
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range->max = pt->max;
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break;
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case NLA_VALIDATE_RANGE_PTR:
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*range = *pt->range;
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break;
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case NLA_VALIDATE_MIN:
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range->min = pt->min;
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break;
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case NLA_VALIDATE_MAX:
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range->max = pt->max;
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break;
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default:
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break;
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}
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}
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static int nla_validate_range_unsigned(const struct nla_policy *pt,
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const struct nlattr *nla,
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struct netlink_ext_ack *extack,
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unsigned int validate)
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{
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struct netlink_range_validation range;
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u64 value;
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switch (pt->type) {
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case NLA_U8:
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value = nla_get_u8(nla);
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break;
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case NLA_U16:
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value = nla_get_u16(nla);
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break;
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case NLA_U32:
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value = nla_get_u32(nla);
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break;
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case NLA_U64:
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value = nla_get_u64(nla);
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break;
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case NLA_UINT:
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value = nla_get_uint(nla);
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break;
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case NLA_MSECS:
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value = nla_get_u64(nla);
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break;
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case NLA_BINARY:
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value = nla_len(nla);
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break;
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case NLA_BE16:
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value = ntohs(nla_get_be16(nla));
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break;
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case NLA_BE32:
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value = ntohl(nla_get_be32(nla));
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break;
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default:
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return -EINVAL;
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}
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nla_get_range_unsigned(pt, &range);
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if (pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG &&
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pt->type == NLA_BINARY && value > range.max) {
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pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
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current->comm, pt->type);
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if (validate & NL_VALIDATE_STRICT_ATTRS) {
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"invalid attribute length");
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return -EINVAL;
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}
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/* this assumes min <= max (don't validate against min) */
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return 0;
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}
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if (value < range.min || value > range.max) {
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bool binary = pt->type == NLA_BINARY;
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if (binary)
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"binary attribute size out of range");
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else
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"integer out of range");
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return -ERANGE;
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}
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return 0;
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}
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void nla_get_range_signed(const struct nla_policy *pt,
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struct netlink_range_validation_signed *range)
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{
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switch (pt->type) {
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case NLA_S8:
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range->min = S8_MIN;
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range->max = S8_MAX;
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break;
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case NLA_S16:
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range->min = S16_MIN;
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range->max = S16_MAX;
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break;
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case NLA_S32:
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range->min = S32_MIN;
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range->max = S32_MAX;
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break;
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case NLA_S64:
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case NLA_SINT:
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range->min = S64_MIN;
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range->max = S64_MAX;
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break;
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default:
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WARN_ON_ONCE(1);
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return;
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}
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switch (pt->validation_type) {
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case NLA_VALIDATE_RANGE:
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range->min = pt->min;
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range->max = pt->max;
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break;
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case NLA_VALIDATE_RANGE_PTR:
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*range = *pt->range_signed;
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break;
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case NLA_VALIDATE_MIN:
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range->min = pt->min;
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break;
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case NLA_VALIDATE_MAX:
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range->max = pt->max;
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break;
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default:
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break;
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}
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}
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static int nla_validate_int_range_signed(const struct nla_policy *pt,
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const struct nlattr *nla,
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struct netlink_ext_ack *extack)
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{
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struct netlink_range_validation_signed range;
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s64 value;
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switch (pt->type) {
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case NLA_S8:
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value = nla_get_s8(nla);
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break;
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case NLA_S16:
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value = nla_get_s16(nla);
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break;
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case NLA_S32:
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value = nla_get_s32(nla);
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break;
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case NLA_S64:
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value = nla_get_s64(nla);
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break;
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case NLA_SINT:
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value = nla_get_sint(nla);
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break;
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default:
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return -EINVAL;
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}
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nla_get_range_signed(pt, &range);
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if (value < range.min || value > range.max) {
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"integer out of range");
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return -ERANGE;
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}
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return 0;
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}
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static int nla_validate_int_range(const struct nla_policy *pt,
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const struct nlattr *nla,
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struct netlink_ext_ack *extack,
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unsigned int validate)
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{
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switch (pt->type) {
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case NLA_U8:
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case NLA_U16:
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case NLA_U32:
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case NLA_U64:
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case NLA_UINT:
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case NLA_MSECS:
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case NLA_BINARY:
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case NLA_BE16:
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case NLA_BE32:
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return nla_validate_range_unsigned(pt, nla, extack, validate);
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case NLA_S8:
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case NLA_S16:
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case NLA_S32:
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case NLA_S64:
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case NLA_SINT:
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return nla_validate_int_range_signed(pt, nla, extack);
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default:
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WARN_ON(1);
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return -EINVAL;
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}
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}
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static int nla_validate_mask(const struct nla_policy *pt,
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const struct nlattr *nla,
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struct netlink_ext_ack *extack)
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{
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u64 value;
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switch (pt->type) {
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case NLA_U8:
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value = nla_get_u8(nla);
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break;
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case NLA_U16:
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value = nla_get_u16(nla);
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break;
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case NLA_U32:
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value = nla_get_u32(nla);
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break;
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case NLA_U64:
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value = nla_get_u64(nla);
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break;
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case NLA_UINT:
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value = nla_get_uint(nla);
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break;
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case NLA_BE16:
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value = ntohs(nla_get_be16(nla));
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break;
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case NLA_BE32:
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value = ntohl(nla_get_be32(nla));
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break;
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default:
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return -EINVAL;
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}
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if (value & ~(u64)pt->mask) {
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NL_SET_ERR_MSG_ATTR(extack, nla, "reserved bit set");
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return -EINVAL;
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}
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return 0;
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}
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static int validate_nla(const struct nlattr *nla, int maxtype,
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const struct nla_policy *policy, unsigned int validate,
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struct netlink_ext_ack *extack, unsigned int depth)
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{
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u16 strict_start_type = policy[0].strict_start_type;
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const struct nla_policy *pt;
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int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
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int err = -ERANGE;
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if (strict_start_type && type >= strict_start_type)
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validate |= NL_VALIDATE_STRICT;
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if (type <= 0 || type > maxtype)
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return 0;
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type = array_index_nospec(type, maxtype + 1);
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pt = &policy[type];
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BUG_ON(pt->type > NLA_TYPE_MAX);
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if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) {
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pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
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current->comm, type);
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if (validate & NL_VALIDATE_STRICT_ATTRS) {
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"invalid attribute length");
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return -EINVAL;
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}
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}
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if (validate & NL_VALIDATE_NESTED) {
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if ((pt->type == NLA_NESTED || pt->type == NLA_NESTED_ARRAY) &&
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!(nla->nla_type & NLA_F_NESTED)) {
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"NLA_F_NESTED is missing");
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return -EINVAL;
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}
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if (pt->type != NLA_NESTED && pt->type != NLA_NESTED_ARRAY &&
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pt->type != NLA_UNSPEC && (nla->nla_type & NLA_F_NESTED)) {
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"NLA_F_NESTED not expected");
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return -EINVAL;
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}
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}
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|
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switch (pt->type) {
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case NLA_REJECT:
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if (extack && pt->reject_message) {
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NL_SET_BAD_ATTR(extack, nla);
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extack->_msg = pt->reject_message;
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return -EINVAL;
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}
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err = -EINVAL;
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goto out_err;
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|
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case NLA_FLAG:
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if (attrlen > 0)
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goto out_err;
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break;
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|
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case NLA_SINT:
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case NLA_UINT:
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if (attrlen != sizeof(u32) && attrlen != sizeof(u64)) {
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NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
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"invalid attribute length");
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return -EINVAL;
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}
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break;
|
|
|
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case NLA_BITFIELD32:
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if (attrlen != sizeof(struct nla_bitfield32))
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goto out_err;
|
|
|
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err = validate_nla_bitfield32(nla, pt->bitfield32_valid);
|
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if (err)
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goto out_err;
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break;
|
|
|
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case NLA_NUL_STRING:
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if (pt->len)
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minlen = min_t(int, attrlen, pt->len + 1);
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else
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minlen = attrlen;
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|
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if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) {
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err = -EINVAL;
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goto out_err;
|
|
}
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fallthrough;
|
|
|
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case NLA_STRING:
|
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if (attrlen < 1)
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goto out_err;
|
|
|
|
if (pt->len) {
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char *buf = nla_data(nla);
|
|
|
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if (buf[attrlen - 1] == '\0')
|
|
attrlen--;
|
|
|
|
if (attrlen > pt->len)
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|
goto out_err;
|
|
}
|
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break;
|
|
|
|
case NLA_BINARY:
|
|
if (pt->len && attrlen > pt->len)
|
|
goto out_err;
|
|
break;
|
|
|
|
case NLA_NESTED:
|
|
/* a nested attributes is allowed to be empty; if its not,
|
|
* it must have a size of at least NLA_HDRLEN.
|
|
*/
|
|
if (attrlen == 0)
|
|
break;
|
|
if (attrlen < NLA_HDRLEN)
|
|
goto out_err;
|
|
if (pt->nested_policy) {
|
|
err = __nla_validate_parse(nla_data(nla), nla_len(nla),
|
|
pt->len, pt->nested_policy,
|
|
validate, extack, NULL,
|
|
depth + 1);
|
|
if (err < 0) {
|
|
/*
|
|
* return directly to preserve the inner
|
|
* error message/attribute pointer
|
|
*/
|
|
return err;
|
|
}
|
|
}
|
|
break;
|
|
case NLA_NESTED_ARRAY:
|
|
/* a nested array attribute is allowed to be empty; if its not,
|
|
* it must have a size of at least NLA_HDRLEN.
|
|
*/
|
|
if (attrlen == 0)
|
|
break;
|
|
if (attrlen < NLA_HDRLEN)
|
|
goto out_err;
|
|
if (pt->nested_policy) {
|
|
int err;
|
|
|
|
err = nla_validate_array(nla_data(nla), nla_len(nla),
|
|
pt->len, pt->nested_policy,
|
|
extack, validate, depth);
|
|
if (err < 0) {
|
|
/*
|
|
* return directly to preserve the inner
|
|
* error message/attribute pointer
|
|
*/
|
|
return err;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case NLA_UNSPEC:
|
|
if (validate & NL_VALIDATE_UNSPEC) {
|
|
NL_SET_ERR_MSG_ATTR(extack, nla,
|
|
"Unsupported attribute");
|
|
return -EINVAL;
|
|
}
|
|
if (attrlen < pt->len)
|
|
goto out_err;
|
|
break;
|
|
|
|
default:
|
|
if (pt->len)
|
|
minlen = pt->len;
|
|
else
|
|
minlen = nla_attr_minlen[pt->type];
|
|
|
|
if (attrlen < minlen)
|
|
goto out_err;
|
|
}
|
|
|
|
/* further validation */
|
|
switch (pt->validation_type) {
|
|
case NLA_VALIDATE_NONE:
|
|
/* nothing to do */
|
|
break;
|
|
case NLA_VALIDATE_RANGE_PTR:
|
|
case NLA_VALIDATE_RANGE:
|
|
case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
|
|
case NLA_VALIDATE_MIN:
|
|
case NLA_VALIDATE_MAX:
|
|
err = nla_validate_int_range(pt, nla, extack, validate);
|
|
if (err)
|
|
return err;
|
|
break;
|
|
case NLA_VALIDATE_MASK:
|
|
err = nla_validate_mask(pt, nla, extack);
|
|
if (err)
|
|
return err;
|
|
break;
|
|
case NLA_VALIDATE_FUNCTION:
|
|
if (pt->validate) {
|
|
err = pt->validate(nla, extack);
|
|
if (err)
|
|
return err;
|
|
}
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
out_err:
|
|
NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
|
|
"Attribute failed policy validation");
|
|
return err;
|
|
}
|
|
|
|
static int __nla_validate_parse(const struct nlattr *head, int len, int maxtype,
|
|
const struct nla_policy *policy,
|
|
unsigned int validate,
|
|
struct netlink_ext_ack *extack,
|
|
struct nlattr **tb, unsigned int depth)
|
|
{
|
|
const struct nlattr *nla;
|
|
int rem;
|
|
|
|
if (depth >= MAX_POLICY_RECURSION_DEPTH) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"allowed policy recursion depth exceeded");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (tb)
|
|
memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
|
|
|
|
nla_for_each_attr(nla, head, len, rem) {
|
|
u16 type = nla_type(nla);
|
|
|
|
if (type == 0 || type > maxtype) {
|
|
if (validate & NL_VALIDATE_MAXTYPE) {
|
|
NL_SET_ERR_MSG_ATTR(extack, nla,
|
|
"Unknown attribute type");
|
|
return -EINVAL;
|
|
}
|
|
continue;
|
|
}
|
|
type = array_index_nospec(type, maxtype + 1);
|
|
if (policy) {
|
|
int err = validate_nla(nla, maxtype, policy,
|
|
validate, extack, depth);
|
|
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
|
|
if (tb)
|
|
tb[type] = (struct nlattr *)nla;
|
|
}
|
|
|
|
if (unlikely(rem > 0)) {
|
|
pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n",
|
|
rem, current->comm);
|
|
NL_SET_ERR_MSG(extack, "bytes leftover after parsing attributes");
|
|
if (validate & NL_VALIDATE_TRAILING)
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __nla_validate - Validate a stream of attributes
|
|
* @head: head of attribute stream
|
|
* @len: length of attribute stream
|
|
* @maxtype: maximum attribute type to be expected
|
|
* @policy: validation policy
|
|
* @validate: validation strictness
|
|
* @extack: extended ACK report struct
|
|
*
|
|
* Validates all attributes in the specified attribute stream against the
|
|
* specified policy. Validation depends on the validate flags passed, see
|
|
* &enum netlink_validation for more details on that.
|
|
* See documentation of struct nla_policy for more details.
|
|
*
|
|
* Returns 0 on success or a negative error code.
|
|
*/
|
|
int __nla_validate(const struct nlattr *head, int len, int maxtype,
|
|
const struct nla_policy *policy, unsigned int validate,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
return __nla_validate_parse(head, len, maxtype, policy, validate,
|
|
extack, NULL, 0);
|
|
}
|
|
EXPORT_SYMBOL(__nla_validate);
|
|
|
|
/**
|
|
* nla_policy_len - Determine the max. length of a policy
|
|
* @p: policy to use
|
|
* @n: number of policies
|
|
*
|
|
* Determines the max. length of the policy. It is currently used
|
|
* to allocated Netlink buffers roughly the size of the actual
|
|
* message.
|
|
*
|
|
* Returns 0 on success or a negative error code.
|
|
*/
|
|
int
|
|
nla_policy_len(const struct nla_policy *p, int n)
|
|
{
|
|
int i, len = 0;
|
|
|
|
for (i = 0; i < n; i++, p++) {
|
|
if (p->len)
|
|
len += nla_total_size(p->len);
|
|
else if (nla_attr_len[p->type])
|
|
len += nla_total_size(nla_attr_len[p->type]);
|
|
else if (nla_attr_minlen[p->type])
|
|
len += nla_total_size(nla_attr_minlen[p->type]);
|
|
}
|
|
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL(nla_policy_len);
|
|
|
|
/**
|
|
* __nla_parse - Parse a stream of attributes into a tb buffer
|
|
* @tb: destination array with maxtype+1 elements
|
|
* @maxtype: maximum attribute type to be expected
|
|
* @head: head of attribute stream
|
|
* @len: length of attribute stream
|
|
* @policy: validation policy
|
|
* @validate: validation strictness
|
|
* @extack: extended ACK pointer
|
|
*
|
|
* Parses a stream of attributes and stores a pointer to each attribute in
|
|
* the tb array accessible via the attribute type.
|
|
* Validation is controlled by the @validate parameter.
|
|
*
|
|
* Returns 0 on success or a negative error code.
|
|
*/
|
|
int __nla_parse(struct nlattr **tb, int maxtype,
|
|
const struct nlattr *head, int len,
|
|
const struct nla_policy *policy, unsigned int validate,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
return __nla_validate_parse(head, len, maxtype, policy, validate,
|
|
extack, tb, 0);
|
|
}
|
|
EXPORT_SYMBOL(__nla_parse);
|
|
|
|
/**
|
|
* nla_find - Find a specific attribute in a stream of attributes
|
|
* @head: head of attribute stream
|
|
* @len: length of attribute stream
|
|
* @attrtype: type of attribute to look for
|
|
*
|
|
* Returns the first attribute in the stream matching the specified type.
|
|
*/
|
|
struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
|
|
{
|
|
const struct nlattr *nla;
|
|
int rem;
|
|
|
|
nla_for_each_attr(nla, head, len, rem)
|
|
if (nla_type(nla) == attrtype)
|
|
return (struct nlattr *)nla;
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(nla_find);
|
|
|
|
/**
|
|
* nla_strscpy - Copy string attribute payload into a sized buffer
|
|
* @dst: Where to copy the string to.
|
|
* @nla: Attribute to copy the string from.
|
|
* @dstsize: Size of destination buffer.
|
|
*
|
|
* Copies at most dstsize - 1 bytes into the destination buffer.
|
|
* Unlike strlcpy the destination buffer is always padded out.
|
|
*
|
|
* Return:
|
|
* * srclen - Returns @nla length (not including the trailing %NUL).
|
|
* * -E2BIG - If @dstsize is 0 or greater than U16_MAX or @nla length greater
|
|
* than @dstsize.
|
|
*/
|
|
ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize)
|
|
{
|
|
size_t srclen = nla_len(nla);
|
|
char *src = nla_data(nla);
|
|
ssize_t ret;
|
|
size_t len;
|
|
|
|
if (dstsize == 0 || WARN_ON_ONCE(dstsize > U16_MAX))
|
|
return -E2BIG;
|
|
|
|
if (srclen > 0 && src[srclen - 1] == '\0')
|
|
srclen--;
|
|
|
|
if (srclen >= dstsize) {
|
|
len = dstsize - 1;
|
|
ret = -E2BIG;
|
|
} else {
|
|
len = srclen;
|
|
ret = len;
|
|
}
|
|
|
|
memcpy(dst, src, len);
|
|
/* Zero pad end of dst. */
|
|
memset(dst + len, 0, dstsize - len);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(nla_strscpy);
|
|
|
|
/**
|
|
* nla_strdup - Copy string attribute payload into a newly allocated buffer
|
|
* @nla: attribute to copy the string from
|
|
* @flags: the type of memory to allocate (see kmalloc).
|
|
*
|
|
* Returns a pointer to the allocated buffer or NULL on error.
|
|
*/
|
|
char *nla_strdup(const struct nlattr *nla, gfp_t flags)
|
|
{
|
|
size_t srclen = nla_len(nla);
|
|
char *src = nla_data(nla), *dst;
|
|
|
|
if (srclen > 0 && src[srclen - 1] == '\0')
|
|
srclen--;
|
|
|
|
dst = kmalloc(srclen + 1, flags);
|
|
if (dst != NULL) {
|
|
memcpy(dst, src, srclen);
|
|
dst[srclen] = '\0';
|
|
}
|
|
return dst;
|
|
}
|
|
EXPORT_SYMBOL(nla_strdup);
|
|
|
|
/**
|
|
* nla_memcpy - Copy a netlink attribute into another memory area
|
|
* @dest: where to copy to memcpy
|
|
* @src: netlink attribute to copy from
|
|
* @count: size of the destination area
|
|
*
|
|
* Note: The number of bytes copied is limited by the length of
|
|
* attribute's payload. memcpy
|
|
*
|
|
* Returns the number of bytes copied.
|
|
*/
|
|
int nla_memcpy(void *dest, const struct nlattr *src, int count)
|
|
{
|
|
int minlen = min_t(int, count, nla_len(src));
|
|
|
|
memcpy(dest, nla_data(src), minlen);
|
|
if (count > minlen)
|
|
memset(dest + minlen, 0, count - minlen);
|
|
|
|
return minlen;
|
|
}
|
|
EXPORT_SYMBOL(nla_memcpy);
|
|
|
|
/**
|
|
* nla_memcmp - Compare an attribute with sized memory area
|
|
* @nla: netlink attribute
|
|
* @data: memory area
|
|
* @size: size of memory area
|
|
*/
|
|
int nla_memcmp(const struct nlattr *nla, const void *data,
|
|
size_t size)
|
|
{
|
|
int d = nla_len(nla) - size;
|
|
|
|
if (d == 0)
|
|
d = memcmp(nla_data(nla), data, size);
|
|
|
|
return d;
|
|
}
|
|
EXPORT_SYMBOL(nla_memcmp);
|
|
|
|
/**
|
|
* nla_strcmp - Compare a string attribute against a string
|
|
* @nla: netlink string attribute
|
|
* @str: another string
|
|
*/
|
|
int nla_strcmp(const struct nlattr *nla, const char *str)
|
|
{
|
|
int len = strlen(str);
|
|
char *buf = nla_data(nla);
|
|
int attrlen = nla_len(nla);
|
|
int d;
|
|
|
|
while (attrlen > 0 && buf[attrlen - 1] == '\0')
|
|
attrlen--;
|
|
|
|
d = attrlen - len;
|
|
if (d == 0)
|
|
d = memcmp(nla_data(nla), str, len);
|
|
|
|
return d;
|
|
}
|
|
EXPORT_SYMBOL(nla_strcmp);
|
|
|
|
#ifdef CONFIG_NET
|
|
/**
|
|
* __nla_reserve - reserve room for attribute on the skb
|
|
* @skb: socket buffer to reserve room on
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
*
|
|
* Adds a netlink attribute header to a socket buffer and reserves
|
|
* room for the payload but does not copy it.
|
|
*
|
|
* The caller is responsible to ensure that the skb provides enough
|
|
* tailroom for the attribute header and payload.
|
|
*/
|
|
struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
|
|
{
|
|
struct nlattr *nla;
|
|
|
|
nla = skb_put(skb, nla_total_size(attrlen));
|
|
nla->nla_type = attrtype;
|
|
nla->nla_len = nla_attr_size(attrlen);
|
|
|
|
memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
|
|
|
|
return nla;
|
|
}
|
|
EXPORT_SYMBOL(__nla_reserve);
|
|
|
|
/**
|
|
* __nla_reserve_64bit - reserve room for attribute on the skb and align it
|
|
* @skb: socket buffer to reserve room on
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
* @padattr: attribute type for the padding
|
|
*
|
|
* Adds a netlink attribute header to a socket buffer and reserves
|
|
* room for the payload but does not copy it. It also ensure that this
|
|
* attribute will have a 64-bit aligned nla_data() area.
|
|
*
|
|
* The caller is responsible to ensure that the skb provides enough
|
|
* tailroom for the attribute header and payload.
|
|
*/
|
|
struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
|
|
int attrlen, int padattr)
|
|
{
|
|
nla_align_64bit(skb, padattr);
|
|
|
|
return __nla_reserve(skb, attrtype, attrlen);
|
|
}
|
|
EXPORT_SYMBOL(__nla_reserve_64bit);
|
|
|
|
/**
|
|
* __nla_reserve_nohdr - reserve room for attribute without header
|
|
* @skb: socket buffer to reserve room on
|
|
* @attrlen: length of attribute payload
|
|
*
|
|
* Reserves room for attribute payload without a header.
|
|
*
|
|
* The caller is responsible to ensure that the skb provides enough
|
|
* tailroom for the payload.
|
|
*/
|
|
void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
|
|
{
|
|
return skb_put_zero(skb, NLA_ALIGN(attrlen));
|
|
}
|
|
EXPORT_SYMBOL(__nla_reserve_nohdr);
|
|
|
|
/**
|
|
* nla_reserve - reserve room for attribute on the skb
|
|
* @skb: socket buffer to reserve room on
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
*
|
|
* Adds a netlink attribute header to a socket buffer and reserves
|
|
* room for the payload but does not copy it.
|
|
*
|
|
* Returns NULL if the tailroom of the skb is insufficient to store
|
|
* the attribute header and payload.
|
|
*/
|
|
struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
|
|
{
|
|
if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
|
|
return NULL;
|
|
|
|
return __nla_reserve(skb, attrtype, attrlen);
|
|
}
|
|
EXPORT_SYMBOL(nla_reserve);
|
|
|
|
/**
|
|
* nla_reserve_64bit - reserve room for attribute on the skb and align it
|
|
* @skb: socket buffer to reserve room on
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
* @padattr: attribute type for the padding
|
|
*
|
|
* Adds a netlink attribute header to a socket buffer and reserves
|
|
* room for the payload but does not copy it. It also ensure that this
|
|
* attribute will have a 64-bit aligned nla_data() area.
|
|
*
|
|
* Returns NULL if the tailroom of the skb is insufficient to store
|
|
* the attribute header and payload.
|
|
*/
|
|
struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, int attrlen,
|
|
int padattr)
|
|
{
|
|
size_t len;
|
|
|
|
if (nla_need_padding_for_64bit(skb))
|
|
len = nla_total_size_64bit(attrlen);
|
|
else
|
|
len = nla_total_size(attrlen);
|
|
if (unlikely(skb_tailroom(skb) < len))
|
|
return NULL;
|
|
|
|
return __nla_reserve_64bit(skb, attrtype, attrlen, padattr);
|
|
}
|
|
EXPORT_SYMBOL(nla_reserve_64bit);
|
|
|
|
/**
|
|
* nla_reserve_nohdr - reserve room for attribute without header
|
|
* @skb: socket buffer to reserve room on
|
|
* @attrlen: length of attribute payload
|
|
*
|
|
* Reserves room for attribute payload without a header.
|
|
*
|
|
* Returns NULL if the tailroom of the skb is insufficient to store
|
|
* the attribute payload.
|
|
*/
|
|
void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
|
|
{
|
|
if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
|
|
return NULL;
|
|
|
|
return __nla_reserve_nohdr(skb, attrlen);
|
|
}
|
|
EXPORT_SYMBOL(nla_reserve_nohdr);
|
|
|
|
/**
|
|
* __nla_put - Add a netlink attribute to a socket buffer
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
* @data: head of attribute payload
|
|
*
|
|
* The caller is responsible to ensure that the skb provides enough
|
|
* tailroom for the attribute header and payload.
|
|
*/
|
|
void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
|
|
const void *data)
|
|
{
|
|
struct nlattr *nla;
|
|
|
|
nla = __nla_reserve(skb, attrtype, attrlen);
|
|
memcpy(nla_data(nla), data, attrlen);
|
|
}
|
|
EXPORT_SYMBOL(__nla_put);
|
|
|
|
/**
|
|
* __nla_put_64bit - Add a netlink attribute to a socket buffer and align it
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
* @data: head of attribute payload
|
|
* @padattr: attribute type for the padding
|
|
*
|
|
* The caller is responsible to ensure that the skb provides enough
|
|
* tailroom for the attribute header and payload.
|
|
*/
|
|
void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
|
|
const void *data, int padattr)
|
|
{
|
|
struct nlattr *nla;
|
|
|
|
nla = __nla_reserve_64bit(skb, attrtype, attrlen, padattr);
|
|
memcpy(nla_data(nla), data, attrlen);
|
|
}
|
|
EXPORT_SYMBOL(__nla_put_64bit);
|
|
|
|
/**
|
|
* __nla_put_nohdr - Add a netlink attribute without header
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrlen: length of attribute payload
|
|
* @data: head of attribute payload
|
|
*
|
|
* The caller is responsible to ensure that the skb provides enough
|
|
* tailroom for the attribute payload.
|
|
*/
|
|
void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
|
|
{
|
|
void *start;
|
|
|
|
start = __nla_reserve_nohdr(skb, attrlen);
|
|
memcpy(start, data, attrlen);
|
|
}
|
|
EXPORT_SYMBOL(__nla_put_nohdr);
|
|
|
|
/**
|
|
* nla_put - Add a netlink attribute to a socket buffer
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
* @data: head of attribute payload
|
|
*
|
|
* Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
|
|
* the attribute header and payload.
|
|
*/
|
|
int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
|
|
{
|
|
if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
|
|
return -EMSGSIZE;
|
|
|
|
__nla_put(skb, attrtype, attrlen, data);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(nla_put);
|
|
|
|
/**
|
|
* nla_put_64bit - Add a netlink attribute to a socket buffer and align it
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrtype: attribute type
|
|
* @attrlen: length of attribute payload
|
|
* @data: head of attribute payload
|
|
* @padattr: attribute type for the padding
|
|
*
|
|
* Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
|
|
* the attribute header and payload.
|
|
*/
|
|
int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
|
|
const void *data, int padattr)
|
|
{
|
|
size_t len;
|
|
|
|
if (nla_need_padding_for_64bit(skb))
|
|
len = nla_total_size_64bit(attrlen);
|
|
else
|
|
len = nla_total_size(attrlen);
|
|
if (unlikely(skb_tailroom(skb) < len))
|
|
return -EMSGSIZE;
|
|
|
|
__nla_put_64bit(skb, attrtype, attrlen, data, padattr);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(nla_put_64bit);
|
|
|
|
/**
|
|
* nla_put_nohdr - Add a netlink attribute without header
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrlen: length of attribute payload
|
|
* @data: head of attribute payload
|
|
*
|
|
* Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
|
|
* the attribute payload.
|
|
*/
|
|
int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
|
|
{
|
|
if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
|
|
return -EMSGSIZE;
|
|
|
|
__nla_put_nohdr(skb, attrlen, data);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(nla_put_nohdr);
|
|
|
|
/**
|
|
* nla_append - Add a netlink attribute without header or padding
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrlen: length of attribute payload
|
|
* @data: head of attribute payload
|
|
*
|
|
* Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
|
|
* the attribute payload.
|
|
*/
|
|
int nla_append(struct sk_buff *skb, int attrlen, const void *data)
|
|
{
|
|
if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
|
|
return -EMSGSIZE;
|
|
|
|
skb_put_data(skb, data, attrlen);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(nla_append);
|
|
#endif
|