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-rw-r--r--include/net/netlink.h372
1 files changed, 327 insertions, 45 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h
index 23f27b0b3cef..395b4406f4b0 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -183,6 +183,7 @@ enum {
NLA_REJECT,
NLA_EXACT_LEN,
NLA_EXACT_LEN_WARN,
+ NLA_MIN_LEN,
__NLA_TYPE_MAX,
};
@@ -212,6 +213,7 @@ enum nla_policy_validation {
* NLA_NUL_STRING Maximum length of string (excluding NUL)
* NLA_FLAG Unused
* NLA_BINARY Maximum length of attribute payload
+ * NLA_MIN_LEN Minimum length of attribute payload
* NLA_NESTED,
* NLA_NESTED_ARRAY Length verification is done by checking len of
* nested header (or empty); len field is used if
@@ -230,6 +232,7 @@ enum nla_policy_validation {
* it is rejected.
* NLA_EXACT_LEN_WARN Attribute should have exactly this length, a warning
* is logged if it is longer, shorter is rejected.
+ * NLA_MIN_LEN Minimum length of attribute payload
* All other Minimum length of attribute payload
*
* Meaning of `validation_data' field:
@@ -281,7 +284,7 @@ enum nla_policy_validation {
* static const struct nla_policy my_policy[ATTR_MAX+1] = {
* [ATTR_FOO] = { .type = NLA_U16 },
* [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
- * [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
+ * [ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) },
* [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags },
* };
*/
@@ -296,12 +299,31 @@ struct nla_policy {
};
int (*validate)(const struct nlattr *attr,
struct netlink_ext_ack *extack);
+ /* This entry is special, and used for the attribute at index 0
+ * only, and specifies special data about the policy, namely it
+ * specifies the "boundary type" where strict length validation
+ * starts for any attribute types >= this value, also, strict
+ * nesting validation starts here.
+ *
+ * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
+ * for any types >= this, so need to use NLA_MIN_LEN to get the
+ * previous pure { .len = xyz } behaviour. The advantage of this
+ * is that types not specified in the policy will be rejected.
+ *
+ * For completely new families it should be set to 1 so that the
+ * validation is enforced for all attributes. For existing ones
+ * it should be set at least when new attributes are added to
+ * the enum used by the policy, and be set to the new value that
+ * was added to enforce strict validation from thereon.
+ */
+ u16 strict_start_type;
};
};
#define NLA_POLICY_EXACT_LEN(_len) { .type = NLA_EXACT_LEN, .len = _len }
#define NLA_POLICY_EXACT_LEN_WARN(_len) { .type = NLA_EXACT_LEN_WARN, \
.len = _len }
+#define NLA_POLICY_MIN_LEN(_len) { .type = NLA_MIN_LEN, .len = _len }
#define NLA_POLICY_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN)
#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
@@ -365,21 +387,52 @@ struct nl_info {
bool skip_notify;
};
+/**
+ * enum netlink_validation - netlink message/attribute validation levels
+ * @NL_VALIDATE_LIBERAL: Old-style "be liberal" validation, not caring about
+ * extra data at the end of the message, attributes being longer than
+ * they should be, or unknown attributes being present.
+ * @NL_VALIDATE_TRAILING: Reject junk data encountered after attribute parsing.
+ * @NL_VALIDATE_MAXTYPE: Reject attributes > max type; Together with _TRAILING
+ * this is equivalent to the old nla_parse_strict()/nlmsg_parse_strict().
+ * @NL_VALIDATE_UNSPEC: Reject attributes with NLA_UNSPEC in the policy.
+ * This can safely be set by the kernel when the given policy has no
+ * NLA_UNSPEC anymore, and can thus be used to ensure policy entries
+ * are enforced going forward.
+ * @NL_VALIDATE_STRICT_ATTRS: strict attribute policy parsing (e.g.
+ * U8, U16, U32 must have exact size, etc.)
+ * @NL_VALIDATE_NESTED: Check that NLA_F_NESTED is set for NLA_NESTED(_ARRAY)
+ * and unset for other policies.
+ */
+enum netlink_validation {
+ NL_VALIDATE_LIBERAL = 0,
+ NL_VALIDATE_TRAILING = BIT(0),
+ NL_VALIDATE_MAXTYPE = BIT(1),
+ NL_VALIDATE_UNSPEC = BIT(2),
+ NL_VALIDATE_STRICT_ATTRS = BIT(3),
+ NL_VALIDATE_NESTED = BIT(4),
+};
+
+#define NL_VALIDATE_DEPRECATED_STRICT (NL_VALIDATE_TRAILING |\
+ NL_VALIDATE_MAXTYPE)
+#define NL_VALIDATE_STRICT (NL_VALIDATE_TRAILING |\
+ NL_VALIDATE_MAXTYPE |\
+ NL_VALIDATE_UNSPEC |\
+ NL_VALIDATE_STRICT_ATTRS |\
+ NL_VALIDATE_NESTED)
+
int netlink_rcv_skb(struct sk_buff *skb,
int (*cb)(struct sk_buff *, struct nlmsghdr *,
struct netlink_ext_ack *));
int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
unsigned int group, int report, gfp_t flags);
-int nla_validate(const struct nlattr *head, int len, int maxtype,
- const struct nla_policy *policy,
- struct netlink_ext_ack *extack);
-int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
- int len, const struct nla_policy *policy,
- struct netlink_ext_ack *extack);
-int nla_parse_strict(struct nlattr **tb, int maxtype, const struct nlattr *head,
- int len, const struct nla_policy *policy,
- struct netlink_ext_ack *extack);
+int __nla_validate(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy, unsigned int validate,
+ struct netlink_ext_ack *extack);
+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);
int nla_policy_len(const struct nla_policy *, int);
struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);
size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);
@@ -508,42 +561,167 @@ nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
}
/**
- * nlmsg_parse - parse attributes of a netlink message
+ * 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
+ * @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 rejected, policy must be specified, attributes
+ * will be validated in the strictest way possible.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+static inline int nla_parse(struct nlattr **tb, int maxtype,
+ const struct nlattr *head, int len,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_parse(tb, maxtype, head, len, policy,
+ NL_VALIDATE_STRICT, extack);
+}
+
+/**
+ * nla_parse_deprecated - 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
+ * @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 ignored and attributes from the policy are not
+ * always strictly validated (only for new attributes).
+ *
+ * Returns 0 on success or a negative error code.
+ */
+static inline int nla_parse_deprecated(struct nlattr **tb, int maxtype,
+ const struct nlattr *head, int len,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_parse(tb, maxtype, head, len, policy,
+ NL_VALIDATE_LIBERAL, extack);
+}
+
+/**
+ * nla_parse_deprecated_strict - 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
+ * @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 rejected as well as trailing data, but the
+ * policy is not completely strictly validated (only for new attributes).
+ *
+ * Returns 0 on success or a negative error code.
+ */
+static inline int nla_parse_deprecated_strict(struct nlattr **tb, int maxtype,
+ const struct nlattr *head,
+ int len,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_parse(tb, maxtype, head, len, policy,
+ NL_VALIDATE_DEPRECATED_STRICT, extack);
+}
+
+/**
+ * __nlmsg_parse - parse attributes of a netlink message
* @nlh: netlink message header
* @hdrlen: length of family specific header
* @tb: destination array with maxtype+1 elements
* @maxtype: maximum attribute type to be expected
* @policy: validation policy
+ * @validate: validation strictness
* @extack: extended ACK report struct
*
* See nla_parse()
*/
-static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
- struct nlattr *tb[], int maxtype,
- const struct nla_policy *policy,
- struct netlink_ext_ack *extack)
+static inline int __nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
+ struct nlattr *tb[], int maxtype,
+ const struct nla_policy *policy,
+ unsigned int validate,
+ struct netlink_ext_ack *extack)
{
if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
NL_SET_ERR_MSG(extack, "Invalid header length");
return -EINVAL;
}
- return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
- nlmsg_attrlen(nlh, hdrlen), policy, extack);
+ return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
+ nlmsg_attrlen(nlh, hdrlen), policy, validate,
+ extack);
}
-static inline int nlmsg_parse_strict(const struct nlmsghdr *nlh, int hdrlen,
- struct nlattr *tb[], int maxtype,
- const struct nla_policy *policy,
- struct netlink_ext_ack *extack)
+/**
+ * nlmsg_parse - parse attributes of a netlink message
+ * @nlh: netlink message header
+ * @hdrlen: length of family specific header
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @validate: validation strictness
+ * @extack: extended ACK report struct
+ *
+ * See nla_parse()
+ */
+static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
+ struct nlattr *tb[], int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
{
- if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) {
- NL_SET_ERR_MSG(extack, "Invalid header length");
- return -EINVAL;
- }
+ return __nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
+ nlmsg_attrlen(nlh, hdrlen), policy,
+ NL_VALIDATE_STRICT, extack);
+}
- return nla_parse_strict(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
- nlmsg_attrlen(nlh, hdrlen), policy, extack);
+/**
+ * nlmsg_parse_deprecated - parse attributes of a netlink message
+ * @nlh: netlink message header
+ * @hdrlen: length of family specific header
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @extack: extended ACK report struct
+ *
+ * See nla_parse_deprecated()
+ */
+static inline int nlmsg_parse_deprecated(const struct nlmsghdr *nlh, int hdrlen,
+ struct nlattr *tb[], int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
+ NL_VALIDATE_LIBERAL, extack);
+}
+
+/**
+ * nlmsg_parse_deprecated_strict - parse attributes of a netlink message
+ * @nlh: netlink message header
+ * @hdrlen: length of family specific header
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @extack: extended ACK report struct
+ *
+ * See nla_parse_deprecated_strict()
+ */
+static inline int
+nlmsg_parse_deprecated_strict(const struct nlmsghdr *nlh, int hdrlen,
+ struct nlattr *tb[], int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nlmsg_parse(nlh, hdrlen, tb, maxtype, policy,
+ NL_VALIDATE_DEPRECATED_STRICT, extack);
}
/**
@@ -562,26 +740,75 @@ static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
}
/**
- * nlmsg_validate - validate a netlink message including attributes
+ * nla_validate_deprecated - 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 is done in liberal mode.
+ * See documenation of struct nla_policy for more details.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+static inline int nla_validate_deprecated(const struct nlattr *head, int len,
+ int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_LIBERAL,
+ extack);
+}
+
+/**
+ * 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 is done in strict mode.
+ * See documenation of struct nla_policy for more details.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+static inline int nla_validate(const struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_validate(head, len, maxtype, policy, NL_VALIDATE_STRICT,
+ extack);
+}
+
+/**
+ * nlmsg_validate_deprecated - validate a netlink message including attributes
* @nlh: netlinket message header
* @hdrlen: length of familiy specific header
* @maxtype: maximum attribute type to be expected
* @policy: validation policy
* @extack: extended ACK report struct
*/
-static inline int nlmsg_validate(const struct nlmsghdr *nlh,
- int hdrlen, int maxtype,
- const struct nla_policy *policy,
- struct netlink_ext_ack *extack)
+static inline int nlmsg_validate_deprecated(const struct nlmsghdr *nlh,
+ int hdrlen, int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
{
if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
return -EINVAL;
- return nla_validate(nlmsg_attrdata(nlh, hdrlen),
- nlmsg_attrlen(nlh, hdrlen), maxtype, policy,
- extack);
+ return __nla_validate(nlmsg_attrdata(nlh, hdrlen),
+ nlmsg_attrlen(nlh, hdrlen), maxtype,
+ policy, NL_VALIDATE_LIBERAL, extack);
}
+
+
/**
* nlmsg_report - need to report back to application?
* @nlh: netlink message header
@@ -909,8 +1136,32 @@ static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
const struct nla_policy *policy,
struct netlink_ext_ack *extack)
{
- return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
- extack);
+ if (!(nla->nla_type & NLA_F_NESTED)) {
+ NL_SET_ERR_MSG_ATTR(extack, nla, "NLA_F_NESTED is missing");
+ return -EINVAL;
+ }
+
+ return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
+ NL_VALIDATE_STRICT, extack);
+}
+
+/**
+ * nla_parse_nested_deprecated - parse nested attributes
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @nla: attribute containing the nested attributes
+ * @policy: validation policy
+ * @extack: extended ACK report struct
+ *
+ * See nla_parse_deprecated()
+ */
+static inline int nla_parse_nested_deprecated(struct nlattr *tb[], int maxtype,
+ const struct nlattr *nla,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy,
+ NL_VALIDATE_LIBERAL, extack);
}
/**
@@ -1415,13 +1666,18 @@ static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp)
}
/**
- * nla_nest_start - Start a new level of nested attributes
+ * nla_nest_start_noflag - Start a new level of nested attributes
* @skb: socket buffer to add attributes to
* @attrtype: attribute type of container
*
- * Returns the container attribute
+ * This function exists for backward compatibility to use in APIs which never
+ * marked their nest attributes with NLA_F_NESTED flag. New APIs should use
+ * nla_nest_start() which sets the flag.
+ *
+ * Returns the container attribute or NULL on error
*/
-static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
+static inline struct nlattr *nla_nest_start_noflag(struct sk_buff *skb,
+ int attrtype)
{
struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
@@ -1432,6 +1688,21 @@ static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
}
/**
+ * nla_nest_start - Start a new level of nested attributes, with NLA_F_NESTED
+ * @skb: socket buffer to add attributes to
+ * @attrtype: attribute type of container
+ *
+ * Unlike nla_nest_start_noflag(), mark the nest attribute with NLA_F_NESTED
+ * flag. This is the preferred function to use in new code.
+ *
+ * Returns the container attribute or NULL on error
+ */
+static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
+{
+ return nla_nest_start_noflag(skb, attrtype | NLA_F_NESTED);
+}
+
+/**
* nla_nest_end - Finalize nesting of attributes
* @skb: socket buffer the attributes are stored in
* @start: container attribute
@@ -1465,6 +1736,7 @@ static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
* @start: container attribute
* @maxtype: maximum attribute type to be expected
* @policy: validation policy
+ * @validate: validation strictness
* @extack: extended ACK report struct
*
* Validates all attributes in the nested attribute stream against the
@@ -1473,12 +1745,22 @@ static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
*
* Returns 0 on success or a negative error code.
*/
-static inline int nla_validate_nested(const struct nlattr *start, int maxtype,
- const struct nla_policy *policy,
- struct netlink_ext_ack *extack)
+static inline int __nla_validate_nested(const struct nlattr *start, int maxtype,
+ const struct nla_policy *policy,
+ unsigned int validate,
+ struct netlink_ext_ack *extack)
+{
+ return __nla_validate(nla_data(start), nla_len(start), maxtype, policy,
+ validate, extack);
+}
+
+static inline int
+nla_validate_nested_deprecated(const struct nlattr *start, int maxtype,
+ const struct nla_policy *policy,
+ struct netlink_ext_ack *extack)
{
- return nla_validate(nla_data(start), nla_len(start), maxtype, policy,
- extack);
+ return __nla_validate_nested(start, maxtype, policy,
+ NL_VALIDATE_LIBERAL, extack);
}
/**