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-rw-r--r--lib/nlattr.c876
1 files changed, 769 insertions, 107 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c
index 18eca7809b08..be9c576b6e2d 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* NETLINK Netlink attributes
*
@@ -9,13 +10,31 @@
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/jiffies.h>
-#include <linux/netdevice.h>
+#include <linux/nospec.h>
#include <linux/skbuff.h>
#include <linux/string.h>
#include <linux/types.h>
#include <net/netlink.h>
-static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = {
+/* For these data types, attribute length should be exactly the given
+ * size. However, to maintain compatibility with broken commands, if the
+ * attribute length does not match the expected size a warning is emitted
+ * to the user that the command is sending invalid data and needs to be fixed.
+ */
+static const u8 nla_attr_len[NLA_TYPE_MAX+1] = {
+ [NLA_U8] = sizeof(u8),
+ [NLA_U16] = sizeof(u16),
+ [NLA_U32] = sizeof(u32),
+ [NLA_U64] = sizeof(u64),
+ [NLA_S8] = sizeof(s8),
+ [NLA_S16] = sizeof(s16),
+ [NLA_S32] = sizeof(s32),
+ [NLA_S64] = sizeof(s64),
+ [NLA_BE16] = sizeof(__be16),
+ [NLA_BE32] = sizeof(__be32),
+};
+
+static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
[NLA_U8] = sizeof(u8),
[NLA_U16] = sizeof(u16),
[NLA_U32] = sizeof(u32),
@@ -26,25 +45,427 @@ static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = {
[NLA_S16] = sizeof(s16),
[NLA_S32] = sizeof(s32),
[NLA_S64] = sizeof(s64),
+ [NLA_BE16] = sizeof(__be16),
+ [NLA_BE32] = sizeof(__be32),
};
+/*
+ * Nested policies might refer back to the original
+ * policy in some cases, and userspace could try to
+ * abuse that and recurse by nesting in the right
+ * ways. Limit recursion to avoid this problem.
+ */
+#define MAX_POLICY_RECURSION_DEPTH 10
+
+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);
+
+static int validate_nla_bitfield32(const struct nlattr *nla,
+ const u32 valid_flags_mask)
+{
+ const struct nla_bitfield32 *bf = nla_data(nla);
+
+ if (!valid_flags_mask)
+ return -EINVAL;
+
+ /*disallow invalid bit selector */
+ if (bf->selector & ~valid_flags_mask)
+ return -EINVAL;
+
+ /*disallow invalid bit values */
+ if (bf->value & ~valid_flags_mask)
+ return -EINVAL;
+
+ /*disallow valid bit values that are not selected*/
+ if (bf->value & ~bf->selector)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int nla_validate_array(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack,
+ unsigned int validate, unsigned int depth)
+{
+ const struct nlattr *entry;
+ int rem;
+
+ nla_for_each_attr(entry, head, len, rem) {
+ int ret;
+
+ if (nla_len(entry) == 0)
+ continue;
+
+ if (nla_len(entry) < NLA_HDRLEN) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, entry, policy,
+ "Array element too short");
+ return -ERANGE;
+ }
+
+ ret = __nla_validate_parse(nla_data(entry), nla_len(entry),
+ maxtype, policy, validate, extack,
+ NULL, depth + 1);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+void nla_get_range_unsigned(const struct nla_policy *pt,
+ struct netlink_range_validation *range)
+{
+ WARN_ON_ONCE(pt->validation_type != NLA_VALIDATE_RANGE_PTR &&
+ (pt->min < 0 || pt->max < 0));
+
+ range->min = 0;
+
+ switch (pt->type) {
+ case NLA_U8:
+ range->max = U8_MAX;
+ break;
+ case NLA_U16:
+ case NLA_BE16:
+ case NLA_BINARY:
+ range->max = U16_MAX;
+ break;
+ case NLA_U32:
+ case NLA_BE32:
+ range->max = U32_MAX;
+ break;
+ case NLA_U64:
+ case NLA_UINT:
+ case NLA_MSECS:
+ range->max = U64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ switch (pt->validation_type) {
+ case NLA_VALIDATE_RANGE:
+ case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
+ range->min = pt->min;
+ range->max = pt->max;
+ break;
+ case NLA_VALIDATE_RANGE_PTR:
+ *range = *pt->range;
+ break;
+ case NLA_VALIDATE_MIN:
+ range->min = pt->min;
+ break;
+ case NLA_VALIDATE_MAX:
+ range->max = pt->max;
+ break;
+ default:
+ break;
+ }
+}
+
+static int nla_validate_range_unsigned(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack,
+ unsigned int validate)
+{
+ struct netlink_range_validation range;
+ u64 value;
+
+ switch (pt->type) {
+ case NLA_U8:
+ value = nla_get_u8(nla);
+ break;
+ case NLA_U16:
+ value = nla_get_u16(nla);
+ break;
+ case NLA_U32:
+ value = nla_get_u32(nla);
+ break;
+ case NLA_U64:
+ value = nla_get_u64(nla);
+ break;
+ case NLA_UINT:
+ value = nla_get_uint(nla);
+ break;
+ case NLA_MSECS:
+ value = nla_get_u64(nla);
+ break;
+ case NLA_BINARY:
+ value = nla_len(nla);
+ break;
+ case NLA_BE16:
+ value = ntohs(nla_get_be16(nla));
+ break;
+ case NLA_BE32:
+ value = ntohl(nla_get_be32(nla));
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ nla_get_range_unsigned(pt, &range);
+
+ if (pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG &&
+ pt->type == NLA_BINARY && value > range.max) {
+ pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
+ current->comm, pt->type);
+ if (validate & NL_VALIDATE_STRICT_ATTRS) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "invalid attribute length");
+ return -EINVAL;
+ }
+
+ /* this assumes min <= max (don't validate against min) */
+ return 0;
+ }
+
+ if (value < range.min || value > range.max) {
+ bool binary = pt->type == NLA_BINARY;
+
+ if (binary)
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "binary attribute size out of range");
+ else
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "integer out of range");
+
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+void nla_get_range_signed(const struct nla_policy *pt,
+ struct netlink_range_validation_signed *range)
+{
+ switch (pt->type) {
+ case NLA_S8:
+ range->min = S8_MIN;
+ range->max = S8_MAX;
+ break;
+ case NLA_S16:
+ range->min = S16_MIN;
+ range->max = S16_MAX;
+ break;
+ case NLA_S32:
+ range->min = S32_MIN;
+ range->max = S32_MAX;
+ break;
+ case NLA_S64:
+ case NLA_SINT:
+ range->min = S64_MIN;
+ range->max = S64_MAX;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ switch (pt->validation_type) {
+ case NLA_VALIDATE_RANGE:
+ range->min = pt->min;
+ range->max = pt->max;
+ break;
+ case NLA_VALIDATE_RANGE_PTR:
+ *range = *pt->range_signed;
+ break;
+ case NLA_VALIDATE_MIN:
+ range->min = pt->min;
+ break;
+ case NLA_VALIDATE_MAX:
+ range->max = pt->max;
+ break;
+ default:
+ break;
+ }
+}
+
+static int nla_validate_int_range_signed(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ struct netlink_range_validation_signed range;
+ s64 value;
+
+ switch (pt->type) {
+ case NLA_S8:
+ value = nla_get_s8(nla);
+ break;
+ case NLA_S16:
+ value = nla_get_s16(nla);
+ break;
+ case NLA_S32:
+ value = nla_get_s32(nla);
+ break;
+ case NLA_S64:
+ value = nla_get_s64(nla);
+ break;
+ case NLA_SINT:
+ value = nla_get_sint(nla);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ nla_get_range_signed(pt, &range);
+
+ if (value < range.min || value > range.max) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "integer out of range");
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+static int nla_validate_int_range(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack,
+ unsigned int validate)
+{
+ switch (pt->type) {
+ case NLA_U8:
+ case NLA_U16:
+ case NLA_U32:
+ case NLA_U64:
+ case NLA_UINT:
+ case NLA_MSECS:
+ case NLA_BINARY:
+ case NLA_BE16:
+ case NLA_BE32:
+ return nla_validate_range_unsigned(pt, nla, extack, validate);
+ case NLA_S8:
+ case NLA_S16:
+ case NLA_S32:
+ case NLA_S64:
+ case NLA_SINT:
+ return nla_validate_int_range_signed(pt, nla, extack);
+ default:
+ WARN_ON(1);
+ return -EINVAL;
+ }
+}
+
+static int nla_validate_mask(const struct nla_policy *pt,
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
+{
+ u64 value;
+
+ switch (pt->type) {
+ case NLA_U8:
+ value = nla_get_u8(nla);
+ break;
+ case NLA_U16:
+ value = nla_get_u16(nla);
+ break;
+ case NLA_U32:
+ value = nla_get_u32(nla);
+ break;
+ case NLA_U64:
+ value = nla_get_u64(nla);
+ break;
+ case NLA_UINT:
+ value = nla_get_uint(nla);
+ break;
+ case NLA_BE16:
+ value = ntohs(nla_get_be16(nla));
+ break;
+ case NLA_BE32:
+ value = ntohl(nla_get_be32(nla));
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (value & ~(u64)pt->mask) {
+ NL_SET_ERR_MSG_ATTR(extack, nla, "reserved bit set");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int validate_nla(const struct nlattr *nla, int maxtype,
- const struct nla_policy *policy)
+ const struct nla_policy *policy, unsigned int validate,
+ struct netlink_ext_ack *extack, unsigned int depth)
{
+ u16 strict_start_type = policy[0].strict_start_type;
const struct nla_policy *pt;
int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
+ int err = -ERANGE;
+
+ if (strict_start_type && type >= strict_start_type)
+ validate |= NL_VALIDATE_STRICT;
if (type <= 0 || type > maxtype)
return 0;
+ type = array_index_nospec(type, maxtype + 1);
pt = &policy[type];
BUG_ON(pt->type > NLA_TYPE_MAX);
+ if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) {
+ pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
+ current->comm, type);
+ if (validate & NL_VALIDATE_STRICT_ATTRS) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "invalid attribute length");
+ return -EINVAL;
+ }
+ }
+
+ if (validate & NL_VALIDATE_NESTED) {
+ if ((pt->type == NLA_NESTED || pt->type == NLA_NESTED_ARRAY) &&
+ !(nla->nla_type & NLA_F_NESTED)) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "NLA_F_NESTED is missing");
+ return -EINVAL;
+ }
+ if (pt->type != NLA_NESTED && pt->type != NLA_NESTED_ARRAY &&
+ pt->type != NLA_UNSPEC && (nla->nla_type & NLA_F_NESTED)) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "NLA_F_NESTED not expected");
+ return -EINVAL;
+ }
+ }
+
switch (pt->type) {
+ case NLA_REJECT:
+ if (extack && pt->reject_message) {
+ NL_SET_BAD_ATTR(extack, nla);
+ extack->_msg = pt->reject_message;
+ return -EINVAL;
+ }
+ err = -EINVAL;
+ goto out_err;
+
case NLA_FLAG:
if (attrlen > 0)
- return -ERANGE;
+ goto out_err;
+ break;
+
+ case NLA_SINT:
+ case NLA_UINT:
+ if (attrlen != sizeof(u32) && attrlen != sizeof(u64)) {
+ NL_SET_ERR_MSG_ATTR_POL(extack, nla, pt,
+ "invalid attribute length");
+ return -EINVAL;
+ }
+ break;
+
+ case NLA_BITFIELD32:
+ if (attrlen != sizeof(struct nla_bitfield32))
+ goto out_err;
+
+ err = validate_nla_bitfield32(nla, pt->bitfield32_valid);
+ if (err)
+ goto out_err;
break;
case NLA_NUL_STRING:
@@ -53,13 +474,15 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
else
minlen = attrlen;
- if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
- return -EINVAL;
- /* fall through */
+ if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL) {
+ err = -EINVAL;
+ goto out_err;
+ }
+ fallthrough;
case NLA_STRING:
if (attrlen < 1)
- return -ERANGE;
+ goto out_err;
if (pt->len) {
char *buf = nla_data(nla);
@@ -68,78 +491,197 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
attrlen--;
if (attrlen > pt->len)
- return -ERANGE;
+ goto out_err;
}
break;
case NLA_BINARY:
if (pt->len && attrlen > pt->len)
- return -ERANGE;
+ goto out_err;
break;
- case NLA_NESTED_COMPAT:
- if (attrlen < pt->len)
- return -ERANGE;
- if (attrlen < NLA_ALIGN(pt->len))
- break;
- if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN)
- return -ERANGE;
- nla = nla_data(nla) + NLA_ALIGN(pt->len);
- if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla))
- return -ERANGE;
- 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 if (pt->type != NLA_UNSPEC)
+ else
minlen = nla_attr_minlen[pt->type];
if (attrlen < minlen)
- return -ERANGE;
+ 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
+ * __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. Attributes with a type exceeding maxtype will be
- * ignored. See documenation of struct nla_policy for more details.
+ * 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)
+int __nla_validate(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy, unsigned int validate,
+ struct netlink_ext_ack *extack)
{
- const struct nlattr *nla;
- int rem, err;
-
- nla_for_each_attr(nla, head, len, rem) {
- err = validate_nla(nla, maxtype, policy);
- if (err < 0)
- goto errout;
- }
-
- err = 0;
-errout:
- return err;
+ return __nla_validate_parse(head, len, maxtype, policy, validate,
+ extack, NULL, 0);
}
+EXPORT_SYMBOL(__nla_validate);
/**
- * nla_policy_len - Determin the max. length of a policy
- * @policy: policy to use
+ * 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
@@ -156,58 +698,41 @@ nla_policy_len(const struct nla_policy *p, int n)
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
+ * __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. Attributes with a type
- * exceeding maxtype will be silently ignored for backwards compatibility
- * reasons. policy may be set to NULL if no validation is required.
+ * 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)
+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)
{
- const struct nlattr *nla;
- int rem, err;
-
- 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 (policy) {
- err = validate_nla(nla, maxtype, policy);
- if (err < 0)
- goto errout;
- }
-
- tb[type] = (struct nlattr *)nla;
- }
- }
-
- if (unlikely(rem > 0))
- printk(KERN_WARNING "netlink: %d bytes leftover after parsing "
- "attributes.\n", rem);
-
- err = 0;
-errout:
- return err;
+ 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
@@ -228,36 +753,74 @@ struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
return NULL;
}
+EXPORT_SYMBOL(nla_find);
/**
- * nla_strlcpy - 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
+ * 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.
- * The result is always a valid NUL-terminated string. Unlike
- * strlcpy the destination buffer is always padded out.
+ * Unlike strscpy() the destination buffer is always padded out.
*
- * Returns the length of the source buffer.
+ * 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.
*/
-size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t 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 (dstsize > 0) {
- size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
-
- memset(dst, 0, dstsize);
- memcpy(dst, src, len);
+ if (srclen >= dstsize) {
+ len = dstsize - 1;
+ ret = -E2BIG;
+ } else {
+ len = srclen;
+ ret = len;
}
- return srclen;
+ 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
@@ -275,9 +838,12 @@ 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
@@ -295,6 +861,7 @@ int nla_memcmp(const struct nlattr *nla, const void *data,
return d;
}
+EXPORT_SYMBOL(nla_memcmp);
/**
* nla_strcmp - Compare a string attribute against a string
@@ -303,14 +870,21 @@ int nla_memcmp(const struct nlattr *nla, const void *data,
*/
int nla_strcmp(const struct nlattr *nla, const char *str)
{
- int len = strlen(str) + 1;
- int d = nla_len(nla) - len;
+ 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
/**
@@ -329,7 +903,7 @@ struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
{
struct nlattr *nla;
- nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen));
+ nla = skb_put(skb, nla_total_size(attrlen));
nla->nla_type = attrtype;
nla->nla_len = nla_attr_size(attrlen);
@@ -340,6 +914,29 @@ struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int 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.
+ *
+ * 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
@@ -351,12 +948,7 @@ EXPORT_SYMBOL(__nla_reserve);
*/
void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
{
- void *start;
-
- start = skb_put(skb, NLA_ALIGN(attrlen));
- memset(start, 0, NLA_ALIGN(attrlen));
-
- return start;
+ return skb_put_zero(skb, NLA_ALIGN(attrlen));
}
EXPORT_SYMBOL(__nla_reserve_nohdr);
@@ -382,6 +974,36 @@ struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int 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
@@ -421,6 +1043,27 @@ void __nla_put(struct sk_buff *skb, int attrtype, int 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
@@ -459,6 +1102,34 @@ int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
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
@@ -491,17 +1162,8 @@ int nla_append(struct sk_buff *skb, int attrlen, const void *data)
if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
return -EMSGSIZE;
- memcpy(skb_put(skb, attrlen), data, attrlen);
+ skb_put_data(skb, data, attrlen);
return 0;
}
EXPORT_SYMBOL(nla_append);
#endif
-
-EXPORT_SYMBOL(nla_validate);
-EXPORT_SYMBOL(nla_policy_len);
-EXPORT_SYMBOL(nla_parse);
-EXPORT_SYMBOL(nla_find);
-EXPORT_SYMBOL(nla_strlcpy);
-EXPORT_SYMBOL(nla_memcpy);
-EXPORT_SYMBOL(nla_memcmp);
-EXPORT_SYMBOL(nla_strcmp);