diff options
Diffstat (limited to 'include/net/netlink.h')
| -rw-r--r-- | include/net/netlink.h | 159 |
1 files changed, 151 insertions, 8 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h index 39e1d875d507..4c1e99303b5a 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -172,7 +172,7 @@ enum { NLA_FLAG, NLA_MSECS, NLA_NESTED, - NLA_NESTED_COMPAT, + NLA_NESTED_ARRAY, NLA_NUL_STRING, NLA_BINARY, NLA_S8, @@ -180,14 +180,28 @@ enum { NLA_S32, NLA_S64, NLA_BITFIELD32, + NLA_REJECT, + NLA_EXACT_LEN, + NLA_EXACT_LEN_WARN, __NLA_TYPE_MAX, }; #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) +enum nla_policy_validation { + NLA_VALIDATE_NONE, + NLA_VALIDATE_RANGE, + NLA_VALIDATE_MIN, + NLA_VALIDATE_MAX, + NLA_VALIDATE_FUNCTION, +}; + /** * struct nla_policy - attribute validation policy * @type: Type of attribute or NLA_UNSPEC + * @validation_type: type of attribute validation done in addition to + * type-specific validation (e.g. range, function call), see + * &enum nla_policy_validation * @len: Type specific length of payload * * Policies are defined as arrays of this struct, the array must be @@ -198,9 +212,11 @@ enum { * NLA_NUL_STRING Maximum length of string (excluding NUL) * NLA_FLAG Unused * NLA_BINARY Maximum length of attribute payload - * NLA_NESTED Don't use `len' field -- length verification is - * done by checking len of nested header (or empty) - * NLA_NESTED_COMPAT Minimum length of structure payload + * NLA_NESTED, + * NLA_NESTED_ARRAY Length verification is done by checking len of + * nested header (or empty); len field is used if + * validation_data is also used, for the max attr + * number in the nested policy. * NLA_U8, NLA_U16, * NLA_U32, NLA_U64, * NLA_S8, NLA_S16, @@ -208,9 +224,59 @@ enum { * NLA_MSECS Leaving the length field zero will verify the * given type fits, using it verifies minimum length * just like "All other" - * NLA_BITFIELD32 A 32-bit bitmap/bitselector attribute + * NLA_BITFIELD32 Unused + * NLA_REJECT Unused + * NLA_EXACT_LEN Attribute must have exactly this length, otherwise + * it is rejected. + * NLA_EXACT_LEN_WARN Attribute should have exactly this length, a warning + * is logged if it is longer, shorter is rejected. * All other Minimum length of attribute payload * + * Meaning of `validation_data' field: + * NLA_BITFIELD32 This is a 32-bit bitmap/bitselector attribute and + * validation data must point to a u32 value of valid + * flags + * NLA_REJECT This attribute is always rejected and validation data + * may point to a string to report as the error instead + * of the generic one in extended ACK. + * NLA_NESTED Points to a nested policy to validate, must also set + * `len' to the max attribute number. + * Note that nla_parse() will validate, but of course not + * parse, the nested sub-policies. + * NLA_NESTED_ARRAY Points to a nested policy to validate, must also set + * `len' to the max attribute number. The difference to + * NLA_NESTED is the structure - NLA_NESTED has the + * nested attributes directly inside, while an array has + * the nested attributes at another level down and the + * attributes directly in the nesting don't matter. + * All other Unused - but note that it's a union + * + * Meaning of `min' and `max' fields, use via NLA_POLICY_MIN, NLA_POLICY_MAX + * and NLA_POLICY_RANGE: + * NLA_U8, + * NLA_U16, + * NLA_U32, + * NLA_U64, + * NLA_S8, + * NLA_S16, + * NLA_S32, + * NLA_S64 These are used depending on the validation_type + * field, if that is min/max/range then the minimum, + * maximum and both are used (respectively) to check + * the value of the integer attribute. + * Note that in the interest of code simplicity and + * struct size both limits are s16, so you cannot + * enforce a range that doesn't fall within the range + * of s16 - do that as usual in the code instead. + * All other Unused - but note that it's a union + * + * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: + * NLA_BINARY Validation function called for the attribute, + * not compatible with use of the validation_data + * as in NLA_BITFIELD32, NLA_REJECT, NLA_NESTED and + * NLA_NESTED_ARRAY. + * All other Unused - but note that it's a union + * * Example: * static const struct nla_policy my_policy[ATTR_MAX+1] = { * [ATTR_FOO] = { .type = NLA_U16 }, @@ -220,11 +286,69 @@ enum { * }; */ struct nla_policy { - u16 type; + u8 type; + u8 validation_type; u16 len; - void *validation_data; + union { + const void *validation_data; + struct { + s16 min, max; + }; + int (*validate)(const struct nlattr *attr, + struct netlink_ext_ack *extack); + }; }; +#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_ETH_ADDR NLA_POLICY_EXACT_LEN(ETH_ALEN) +#define NLA_POLICY_ETH_ADDR_COMPAT NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN) + +#define NLA_POLICY_NESTED(maxattr, policy) \ + { .type = NLA_NESTED, .validation_data = policy, .len = maxattr } +#define NLA_POLICY_NESTED_ARRAY(maxattr, policy) \ + { .type = NLA_NESTED_ARRAY, .validation_data = policy, .len = maxattr } + +#define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition)) +#define NLA_ENSURE_INT_TYPE(tp) \ + (__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 || \ + tp == NLA_S16 || tp == NLA_U16 || \ + tp == NLA_S32 || tp == NLA_U32 || \ + tp == NLA_S64 || tp == NLA_U64) + tp) +#define NLA_ENSURE_NO_VALIDATION_PTR(tp) \ + (__NLA_ENSURE(tp != NLA_BITFIELD32 && \ + tp != NLA_REJECT && \ + tp != NLA_NESTED && \ + tp != NLA_NESTED_ARRAY) + tp) + +#define NLA_POLICY_RANGE(tp, _min, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_RANGE, \ + .min = _min, \ + .max = _max \ +} + +#define NLA_POLICY_MIN(tp, _min) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MIN, \ + .min = _min, \ +} + +#define NLA_POLICY_MAX(tp, _max) { \ + .type = NLA_ENSURE_INT_TYPE(tp), \ + .validation_type = NLA_VALIDATE_MAX, \ + .max = _max, \ +} + +#define NLA_POLICY_VALIDATE_FN(tp, fn, ...) { \ + .type = NLA_ENSURE_NO_VALIDATION_PTR(tp), \ + .validation_type = NLA_VALIDATE_FUNCTION, \ + .validate = fn, \ + .len = __VA_ARGS__ + 0, \ +} + /** * struct nl_info - netlink source information * @nlh: Netlink message header of original request @@ -249,6 +373,9 @@ int nla_validate(const struct nlattr *head, int len, int maxtype, 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_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); @@ -392,13 +519,29 @@ static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen, const struct nla_policy *policy, struct netlink_ext_ack *extack) { - if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) + 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); } +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) +{ + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) { + NL_SET_ERR_MSG(extack, "Invalid header length"); + return -EINVAL; + } + + return nla_parse_strict(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), policy, extack); +} + /** * nlmsg_find_attr - find a specific attribute in a netlink message * @nlh: netlink message header |