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Diffstat (limited to 'include/net/netlink.h')
| -rw-r--r-- | include/net/netlink.h | 1423 |
1 files changed, 1423 insertions, 0 deletions
diff --git a/include/net/netlink.h b/include/net/netlink.h new file mode 100644 index 000000000..39e1d875d --- /dev/null +++ b/include/net/netlink.h @@ -0,0 +1,1423 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_NETLINK_H +#define __NET_NETLINK_H + +#include <linux/types.h> +#include <linux/netlink.h> +#include <linux/jiffies.h> +#include <linux/in6.h> + +/* ======================================================================== + * Netlink Messages and Attributes Interface (As Seen On TV) + * ------------------------------------------------------------------------ + * Messages Interface + * ------------------------------------------------------------------------ + * + * Message Format: + * <--- nlmsg_total_size(payload) ---> + * <-- nlmsg_msg_size(payload) -> + * +----------+- - -+-------------+- - -+-------- - - + * | nlmsghdr | Pad | Payload | Pad | nlmsghdr + * +----------+- - -+-------------+- - -+-------- - - + * nlmsg_data(nlh)---^ ^ + * nlmsg_next(nlh)-----------------------+ + * + * Payload Format: + * <---------------------- nlmsg_len(nlh) ---------------------> + * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> + * +----------------------+- - -+--------------------------------+ + * | Family Header | Pad | Attributes | + * +----------------------+- - -+--------------------------------+ + * nlmsg_attrdata(nlh, hdrlen)---^ + * + * Data Structures: + * struct nlmsghdr netlink message header + * + * Message Construction: + * nlmsg_new() create a new netlink message + * nlmsg_put() add a netlink message to an skb + * nlmsg_put_answer() callback based nlmsg_put() + * nlmsg_end() finalize netlink message + * nlmsg_get_pos() return current position in message + * nlmsg_trim() trim part of message + * nlmsg_cancel() cancel message construction + * nlmsg_free() free a netlink message + * + * Message Sending: + * nlmsg_multicast() multicast message to several groups + * nlmsg_unicast() unicast a message to a single socket + * nlmsg_notify() send notification message + * + * Message Length Calculations: + * nlmsg_msg_size(payload) length of message w/o padding + * nlmsg_total_size(payload) length of message w/ padding + * nlmsg_padlen(payload) length of padding at tail + * + * Message Payload Access: + * nlmsg_data(nlh) head of message payload + * nlmsg_len(nlh) length of message payload + * nlmsg_attrdata(nlh, hdrlen) head of attributes data + * nlmsg_attrlen(nlh, hdrlen) length of attributes data + * + * Message Parsing: + * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? + * nlmsg_next(nlh, remaining) get next netlink message + * nlmsg_parse() parse attributes of a message + * nlmsg_find_attr() find an attribute in a message + * nlmsg_for_each_msg() loop over all messages + * nlmsg_validate() validate netlink message incl. attrs + * nlmsg_for_each_attr() loop over all attributes + * + * Misc: + * nlmsg_report() report back to application? + * + * ------------------------------------------------------------------------ + * Attributes Interface + * ------------------------------------------------------------------------ + * + * Attribute Format: + * <------- nla_total_size(payload) -------> + * <---- nla_attr_size(payload) -----> + * +----------+- - -+- - - - - - - - - +- - -+-------- - - + * | Header | Pad | Payload | Pad | Header + * +----------+- - -+- - - - - - - - - +- - -+-------- - - + * <- nla_len(nla) -> ^ + * nla_data(nla)----^ | + * nla_next(nla)-----------------------------' + * + * Data Structures: + * struct nlattr netlink attribute header + * + * Attribute Construction: + * nla_reserve(skb, type, len) reserve room for an attribute + * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr + * nla_put(skb, type, len, data) add attribute to skb + * nla_put_nohdr(skb, len, data) add attribute w/o hdr + * nla_append(skb, len, data) append data to skb + * + * Attribute Construction for Basic Types: + * nla_put_u8(skb, type, value) add u8 attribute to skb + * nla_put_u16(skb, type, value) add u16 attribute to skb + * nla_put_u32(skb, type, value) add u32 attribute to skb + * nla_put_u64_64bit(skb, type, + * value, padattr) add u64 attribute to skb + * nla_put_s8(skb, type, value) add s8 attribute to skb + * nla_put_s16(skb, type, value) add s16 attribute to skb + * nla_put_s32(skb, type, value) add s32 attribute to skb + * nla_put_s64(skb, type, value, + * padattr) add s64 attribute to skb + * nla_put_string(skb, type, str) add string attribute to skb + * nla_put_flag(skb, type) add flag attribute to skb + * nla_put_msecs(skb, type, jiffies, + * padattr) add msecs attribute to skb + * nla_put_in_addr(skb, type, addr) add IPv4 address attribute to skb + * nla_put_in6_addr(skb, type, addr) add IPv6 address attribute to skb + * + * Nested Attributes Construction: + * nla_nest_start(skb, type) start a nested attribute + * nla_nest_end(skb, nla) finalize a nested attribute + * nla_nest_cancel(skb, nla) cancel nested attribute construction + * + * Attribute Length Calculations: + * nla_attr_size(payload) length of attribute w/o padding + * nla_total_size(payload) length of attribute w/ padding + * nla_padlen(payload) length of padding + * + * Attribute Payload Access: + * nla_data(nla) head of attribute payload + * nla_len(nla) length of attribute payload + * + * Attribute Payload Access for Basic Types: + * nla_get_u8(nla) get payload for a u8 attribute + * nla_get_u16(nla) get payload for a u16 attribute + * nla_get_u32(nla) get payload for a u32 attribute + * nla_get_u64(nla) get payload for a u64 attribute + * nla_get_s8(nla) get payload for a s8 attribute + * nla_get_s16(nla) get payload for a s16 attribute + * nla_get_s32(nla) get payload for a s32 attribute + * nla_get_s64(nla) get payload for a s64 attribute + * nla_get_flag(nla) return 1 if flag is true + * nla_get_msecs(nla) get payload for a msecs attribute + * + * Attribute Misc: + * nla_memcpy(dest, nla, count) copy attribute into memory + * nla_memcmp(nla, data, size) compare attribute with memory area + * nla_strlcpy(dst, nla, size) copy attribute to a sized string + * nla_strcmp(nla, str) compare attribute with string + * + * Attribute Parsing: + * nla_ok(nla, remaining) does nla fit into remaining bytes? + * nla_next(nla, remaining) get next netlink attribute + * nla_validate() validate a stream of attributes + * nla_validate_nested() validate a stream of nested attributes + * nla_find() find attribute in stream of attributes + * nla_find_nested() find attribute in nested attributes + * nla_parse() parse and validate stream of attrs + * nla_parse_nested() parse nested attributes + * nla_for_each_attr() loop over all attributes + * nla_for_each_nested() loop over the nested attributes + *========================================================================= + */ + + /** + * Standard attribute types to specify validation policy + */ +enum { + NLA_UNSPEC, + NLA_U8, + NLA_U16, + NLA_U32, + NLA_U64, + NLA_STRING, + NLA_FLAG, + NLA_MSECS, + NLA_NESTED, + NLA_NESTED_COMPAT, + NLA_NUL_STRING, + NLA_BINARY, + NLA_S8, + NLA_S16, + NLA_S32, + NLA_S64, + NLA_BITFIELD32, + __NLA_TYPE_MAX, +}; + +#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) + +/** + * struct nla_policy - attribute validation policy + * @type: Type of attribute or NLA_UNSPEC + * @len: Type specific length of payload + * + * Policies are defined as arrays of this struct, the array must be + * accessible by attribute type up to the highest identifier to be expected. + * + * Meaning of `len' field: + * NLA_STRING Maximum length of string + * 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_U8, NLA_U16, + * NLA_U32, NLA_U64, + * NLA_S8, NLA_S16, + * NLA_S32, NLA_S64, + * 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 + * All other Minimum length of attribute payload + * + * Example: + * 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_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags }, + * }; + */ +struct nla_policy { + u16 type; + u16 len; + void *validation_data; +}; + +/** + * struct nl_info - netlink source information + * @nlh: Netlink message header of original request + * @portid: Netlink PORTID of requesting application + */ +struct nl_info { + struct nlmsghdr *nlh; + struct net *nl_net; + u32 portid; + bool skip_notify; +}; + +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_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); +char *nla_strdup(const struct nlattr *nla, gfp_t flags); +int nla_memcpy(void *dest, const struct nlattr *src, int count); +int nla_memcmp(const struct nlattr *nla, const void *data, size_t size); +int nla_strcmp(const struct nlattr *nla, const char *str); +struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); +struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype, + int attrlen, int padattr); +void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen); +struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); +struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype, + int attrlen, int padattr); +void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen); +void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, + const void *data); +void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr); +void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); +int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); +int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen, + const void *data, int padattr); +int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data); +int nla_append(struct sk_buff *skb, int attrlen, const void *data); + +/************************************************************************** + * Netlink Messages + **************************************************************************/ + +/** + * nlmsg_msg_size - length of netlink message not including padding + * @payload: length of message payload + */ +static inline int nlmsg_msg_size(int payload) +{ + return NLMSG_HDRLEN + payload; +} + +/** + * nlmsg_total_size - length of netlink message including padding + * @payload: length of message payload + */ +static inline int nlmsg_total_size(int payload) +{ + return NLMSG_ALIGN(nlmsg_msg_size(payload)); +} + +/** + * nlmsg_padlen - length of padding at the message's tail + * @payload: length of message payload + */ +static inline int nlmsg_padlen(int payload) +{ + return nlmsg_total_size(payload) - nlmsg_msg_size(payload); +} + +/** + * nlmsg_data - head of message payload + * @nlh: netlink message header + */ +static inline void *nlmsg_data(const struct nlmsghdr *nlh) +{ + return (unsigned char *) nlh + NLMSG_HDRLEN; +} + +/** + * nlmsg_len - length of message payload + * @nlh: netlink message header + */ +static inline int nlmsg_len(const struct nlmsghdr *nlh) +{ + return nlh->nlmsg_len - NLMSG_HDRLEN; +} + +/** + * nlmsg_attrdata - head of attributes data + * @nlh: netlink message header + * @hdrlen: length of family specific header + */ +static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, + int hdrlen) +{ + unsigned char *data = nlmsg_data(nlh); + return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); +} + +/** + * nlmsg_attrlen - length of attributes data + * @nlh: netlink message header + * @hdrlen: length of family specific header + */ +static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) +{ + return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); +} + +/** + * nlmsg_ok - check if the netlink message fits into the remaining bytes + * @nlh: netlink message header + * @remaining: number of bytes remaining in message stream + */ +static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) +{ + return (remaining >= (int) sizeof(struct nlmsghdr) && + nlh->nlmsg_len >= sizeof(struct nlmsghdr) && + nlh->nlmsg_len <= remaining); +} + +/** + * nlmsg_next - next netlink message in message stream + * @nlh: netlink message header + * @remaining: number of bytes remaining in message stream + * + * Returns the next netlink message in the message stream and + * decrements remaining by the size of the current message. + */ +static inline struct nlmsghdr * +nlmsg_next(const struct nlmsghdr *nlh, int *remaining) +{ + int totlen = NLMSG_ALIGN(nlh->nlmsg_len); + + *remaining -= totlen; + + return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); +} + +/** + * 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 + * @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)) + return -EINVAL; + + return nla_parse(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 + * @hdrlen: length of familiy specific header + * @attrtype: type of attribute to look for + * + * Returns the first attribute which matches the specified type. + */ +static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh, + int hdrlen, int attrtype) +{ + return nla_find(nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), attrtype); +} + +/** + * nlmsg_validate - 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) +{ + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) + return -EINVAL; + + return nla_validate(nlmsg_attrdata(nlh, hdrlen), + nlmsg_attrlen(nlh, hdrlen), maxtype, policy, + extack); +} + +/** + * nlmsg_report - need to report back to application? + * @nlh: netlink message header + * + * Returns 1 if a report back to the application is requested. + */ +static inline int nlmsg_report(const struct nlmsghdr *nlh) +{ + return !!(nlh->nlmsg_flags & NLM_F_ECHO); +} + +/** + * nlmsg_for_each_attr - iterate over a stream of attributes + * @pos: loop counter, set to current attribute + * @nlh: netlink message header + * @hdrlen: length of familiy specific header + * @rem: initialized to len, holds bytes currently remaining in stream + */ +#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ + nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ + nlmsg_attrlen(nlh, hdrlen), rem) + +/** + * nlmsg_put - Add a new netlink message to an skb + * @skb: socket buffer to store message in + * @portid: netlink PORTID of requesting application + * @seq: sequence number of message + * @type: message type + * @payload: length of message payload + * @flags: message flags + * + * Returns NULL if the tailroom of the skb is insufficient to store + * the message header and payload. + */ +static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, + int type, int payload, int flags) +{ + if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) + return NULL; + + return __nlmsg_put(skb, portid, seq, type, payload, flags); +} + +/** + * nlmsg_put_answer - Add a new callback based netlink message to an skb + * @skb: socket buffer to store message in + * @cb: netlink callback + * @type: message type + * @payload: length of message payload + * @flags: message flags + * + * Returns NULL if the tailroom of the skb is insufficient to store + * the message header and payload. + */ +static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, + struct netlink_callback *cb, + int type, int payload, + int flags) +{ + return nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, + type, payload, flags); +} + +/** + * nlmsg_new - Allocate a new netlink message + * @payload: size of the message payload + * @flags: the type of memory to allocate. + * + * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known + * and a good default is needed. + */ +static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) +{ + return alloc_skb(nlmsg_total_size(payload), flags); +} + +/** + * nlmsg_end - Finalize a netlink message + * @skb: socket buffer the message is stored in + * @nlh: netlink message header + * + * Corrects the netlink message header to include the appeneded + * attributes. Only necessary if attributes have been added to + * the message. + */ +static inline void nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) +{ + nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh; +} + +/** + * nlmsg_get_pos - return current position in netlink message + * @skb: socket buffer the message is stored in + * + * Returns a pointer to the current tail of the message. + */ +static inline void *nlmsg_get_pos(struct sk_buff *skb) +{ + return skb_tail_pointer(skb); +} + +/** + * nlmsg_trim - Trim message to a mark + * @skb: socket buffer the message is stored in + * @mark: mark to trim to + * + * Trims the message to the provided mark. + */ +static inline void nlmsg_trim(struct sk_buff *skb, const void *mark) +{ + if (mark) { + WARN_ON((unsigned char *) mark < skb->data); + skb_trim(skb, (unsigned char *) mark - skb->data); + } +} + +/** + * nlmsg_cancel - Cancel construction of a netlink message + * @skb: socket buffer the message is stored in + * @nlh: netlink message header + * + * Removes the complete netlink message including all + * attributes from the socket buffer again. + */ +static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) +{ + nlmsg_trim(skb, nlh); +} + +/** + * nlmsg_free - free a netlink message + * @skb: socket buffer of netlink message + */ +static inline void nlmsg_free(struct sk_buff *skb) +{ + kfree_skb(skb); +} + +/** + * nlmsg_multicast - multicast a netlink message + * @sk: netlink socket to spread messages to + * @skb: netlink message as socket buffer + * @portid: own netlink portid to avoid sending to yourself + * @group: multicast group id + * @flags: allocation flags + */ +static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, + u32 portid, unsigned int group, gfp_t flags) +{ + int err; + + NETLINK_CB(skb).dst_group = group; + + err = netlink_broadcast(sk, skb, portid, group, flags); + if (err > 0) + err = 0; + + return err; +} + +/** + * nlmsg_unicast - unicast a netlink message + * @sk: netlink socket to spread message to + * @skb: netlink message as socket buffer + * @portid: netlink portid of the destination socket + */ +static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 portid) +{ + int err; + + err = netlink_unicast(sk, skb, portid, MSG_DONTWAIT); + if (err > 0) + err = 0; + + return err; +} + +/** + * nlmsg_for_each_msg - iterate over a stream of messages + * @pos: loop counter, set to current message + * @head: head of message stream + * @len: length of message stream + * @rem: initialized to len, holds bytes currently remaining in stream + */ +#define nlmsg_for_each_msg(pos, head, len, rem) \ + for (pos = head, rem = len; \ + nlmsg_ok(pos, rem); \ + pos = nlmsg_next(pos, &(rem))) + +/** + * nl_dump_check_consistent - check if sequence is consistent and advertise if not + * @cb: netlink callback structure that stores the sequence number + * @nlh: netlink message header to write the flag to + * + * This function checks if the sequence (generation) number changed during dump + * and if it did, advertises it in the netlink message header. + * + * The correct way to use it is to set cb->seq to the generation counter when + * all locks for dumping have been acquired, and then call this function for + * each message that is generated. + * + * Note that due to initialisation concerns, 0 is an invalid sequence number + * and must not be used by code that uses this functionality. + */ +static inline void +nl_dump_check_consistent(struct netlink_callback *cb, + struct nlmsghdr *nlh) +{ + if (cb->prev_seq && cb->seq != cb->prev_seq) + nlh->nlmsg_flags |= NLM_F_DUMP_INTR; + cb->prev_seq = cb->seq; +} + +/************************************************************************** + * Netlink Attributes + **************************************************************************/ + +/** + * nla_attr_size - length of attribute not including padding + * @payload: length of payload + */ +static inline int nla_attr_size(int payload) +{ + return NLA_HDRLEN + payload; +} + +/** + * nla_total_size - total length of attribute including padding + * @payload: length of payload + */ +static inline int nla_total_size(int payload) +{ + return NLA_ALIGN(nla_attr_size(payload)); +} + +/** + * nla_padlen - length of padding at the tail of attribute + * @payload: length of payload + */ +static inline int nla_padlen(int payload) +{ + return nla_total_size(payload) - nla_attr_size(payload); +} + +/** + * nla_type - attribute type + * @nla: netlink attribute + */ +static inline int nla_type(const struct nlattr *nla) +{ + return nla->nla_type & NLA_TYPE_MASK; +} + +/** + * nla_data - head of payload + * @nla: netlink attribute + */ +static inline void *nla_data(const struct nlattr *nla) +{ + return (char *) nla + NLA_HDRLEN; +} + +/** + * nla_len - length of payload + * @nla: netlink attribute + */ +static inline int nla_len(const struct nlattr *nla) +{ + return nla->nla_len - NLA_HDRLEN; +} + +/** + * nla_ok - check if the netlink attribute fits into the remaining bytes + * @nla: netlink attribute + * @remaining: number of bytes remaining in attribute stream + */ +static inline int nla_ok(const struct nlattr *nla, int remaining) +{ + return remaining >= (int) sizeof(*nla) && + nla->nla_len >= sizeof(*nla) && + nla->nla_len <= remaining; +} + +/** + * nla_next - next netlink attribute in attribute stream + * @nla: netlink attribute + * @remaining: number of bytes remaining in attribute stream + * + * Returns the next netlink attribute in the attribute stream and + * decrements remaining by the size of the current attribute. + */ +static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) +{ + unsigned int totlen = NLA_ALIGN(nla->nla_len); + + *remaining -= totlen; + return (struct nlattr *) ((char *) nla + totlen); +} + +/** + * nla_find_nested - find attribute in a set of nested attributes + * @nla: attribute containing the nested attributes + * @attrtype: type of attribute to look for + * + * Returns the first attribute which matches the specified type. + */ +static inline struct nlattr * +nla_find_nested(const struct nlattr *nla, int attrtype) +{ + return nla_find(nla_data(nla), nla_len(nla), attrtype); +} + +/** + * nla_parse_nested - 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() + */ +static inline int nla_parse_nested(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, + extack); +} + +/** + * nla_put_u8 - Add a u8 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) +{ + /* temporary variables to work around GCC PR81715 with asan-stack=1 */ + u8 tmp = value; + + return nla_put(skb, attrtype, sizeof(u8), &tmp); +} + +/** + * nla_put_u16 - Add a u16 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) +{ + u16 tmp = value; + + return nla_put(skb, attrtype, sizeof(u16), &tmp); +} + +/** + * nla_put_be16 - Add a __be16 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_be16(struct sk_buff *skb, int attrtype, __be16 value) +{ + __be16 tmp = value; + + return nla_put(skb, attrtype, sizeof(__be16), &tmp); +} + +/** + * nla_put_net16 - Add 16-bit network byte order netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_net16(struct sk_buff *skb, int attrtype, __be16 value) +{ + __be16 tmp = value; + + return nla_put_be16(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); +} + +/** + * nla_put_le16 - Add a __le16 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_le16(struct sk_buff *skb, int attrtype, __le16 value) +{ + __le16 tmp = value; + + return nla_put(skb, attrtype, sizeof(__le16), &tmp); +} + +/** + * nla_put_u32 - Add a u32 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) +{ + u32 tmp = value; + + return nla_put(skb, attrtype, sizeof(u32), &tmp); +} + +/** + * nla_put_be32 - Add a __be32 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_be32(struct sk_buff *skb, int attrtype, __be32 value) +{ + __be32 tmp = value; + + return nla_put(skb, attrtype, sizeof(__be32), &tmp); +} + +/** + * nla_put_net32 - Add 32-bit network byte order netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_net32(struct sk_buff *skb, int attrtype, __be32 value) +{ + __be32 tmp = value; + + return nla_put_be32(skb, attrtype | NLA_F_NET_BYTEORDER, tmp); +} + +/** + * nla_put_le32 - Add a __le32 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_le32(struct sk_buff *skb, int attrtype, __le32 value) +{ + __le32 tmp = value; + + return nla_put(skb, attrtype, sizeof(__le32), &tmp); +} + +/** + * nla_put_u64_64bit - Add a u64 netlink attribute to a skb and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + * @padattr: attribute type for the padding + */ +static inline int nla_put_u64_64bit(struct sk_buff *skb, int attrtype, + u64 value, int padattr) +{ + u64 tmp = value; + + return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); +} + +/** + * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + * @padattr: attribute type for the padding + */ +static inline int nla_put_be64(struct sk_buff *skb, int attrtype, __be64 value, + int padattr) +{ + __be64 tmp = value; + + return nla_put_64bit(skb, attrtype, sizeof(__be64), &tmp, padattr); +} + +/** + * nla_put_net64 - Add 64-bit network byte order nlattr to a skb and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + * @padattr: attribute type for the padding + */ +static inline int nla_put_net64(struct sk_buff *skb, int attrtype, __be64 value, + int padattr) +{ + __be64 tmp = value; + + return nla_put_be64(skb, attrtype | NLA_F_NET_BYTEORDER, tmp, + padattr); +} + +/** + * nla_put_le64 - Add a __le64 netlink attribute to a socket buffer and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + * @padattr: attribute type for the padding + */ +static inline int nla_put_le64(struct sk_buff *skb, int attrtype, __le64 value, + int padattr) +{ + __le64 tmp = value; + + return nla_put_64bit(skb, attrtype, sizeof(__le64), &tmp, padattr); +} + +/** + * nla_put_s8 - Add a s8 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_s8(struct sk_buff *skb, int attrtype, s8 value) +{ + s8 tmp = value; + + return nla_put(skb, attrtype, sizeof(s8), &tmp); +} + +/** + * nla_put_s16 - Add a s16 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_s16(struct sk_buff *skb, int attrtype, s16 value) +{ + s16 tmp = value; + + return nla_put(skb, attrtype, sizeof(s16), &tmp); +} + +/** + * nla_put_s32 - Add a s32 netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + */ +static inline int nla_put_s32(struct sk_buff *skb, int attrtype, s32 value) +{ + s32 tmp = value; + + return nla_put(skb, attrtype, sizeof(s32), &tmp); +} + +/** + * nla_put_s64 - Add a s64 netlink attribute to a socket buffer and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @value: numeric value + * @padattr: attribute type for the padding + */ +static inline int nla_put_s64(struct sk_buff *skb, int attrtype, s64 value, + int padattr) +{ + s64 tmp = value; + + return nla_put_64bit(skb, attrtype, sizeof(s64), &tmp, padattr); +} + +/** + * nla_put_string - Add a string netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @str: NUL terminated string + */ +static inline int nla_put_string(struct sk_buff *skb, int attrtype, + const char *str) +{ + return nla_put(skb, attrtype, strlen(str) + 1, str); +} + +/** + * nla_put_flag - Add a flag netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + */ +static inline int nla_put_flag(struct sk_buff *skb, int attrtype) +{ + return nla_put(skb, attrtype, 0, NULL); +} + +/** + * nla_put_msecs - Add a msecs netlink attribute to a skb and align it + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @njiffies: number of jiffies to convert to msecs + * @padattr: attribute type for the padding + */ +static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, + unsigned long njiffies, int padattr) +{ + u64 tmp = jiffies_to_msecs(njiffies); + + return nla_put_64bit(skb, attrtype, sizeof(u64), &tmp, padattr); +} + +/** + * nla_put_in_addr - Add an IPv4 address netlink attribute to a socket + * buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @addr: IPv4 address + */ +static inline int nla_put_in_addr(struct sk_buff *skb, int attrtype, + __be32 addr) +{ + __be32 tmp = addr; + + return nla_put_be32(skb, attrtype, tmp); +} + +/** + * nla_put_in6_addr - Add an IPv6 address netlink attribute to a socket + * buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @addr: IPv6 address + */ +static inline int nla_put_in6_addr(struct sk_buff *skb, int attrtype, + const struct in6_addr *addr) +{ + return nla_put(skb, attrtype, sizeof(*addr), addr); +} + +/** + * nla_get_u32 - return payload of u32 attribute + * @nla: u32 netlink attribute + */ +static inline u32 nla_get_u32(const struct nlattr *nla) +{ + return *(u32 *) nla_data(nla); +} + +/** + * nla_get_be32 - return payload of __be32 attribute + * @nla: __be32 netlink attribute + */ +static inline __be32 nla_get_be32(const struct nlattr *nla) +{ + return *(__be32 *) nla_data(nla); +} + +/** + * nla_get_le32 - return payload of __le32 attribute + * @nla: __le32 netlink attribute + */ +static inline __le32 nla_get_le32(const struct nlattr *nla) +{ + return *(__le32 *) nla_data(nla); +} + +/** + * nla_get_u16 - return payload of u16 attribute + * @nla: u16 netlink attribute + */ +static inline u16 nla_get_u16(const struct nlattr *nla) +{ + return *(u16 *) nla_data(nla); +} + +/** + * nla_get_be16 - return payload of __be16 attribute + * @nla: __be16 netlink attribute + */ +static inline __be16 nla_get_be16(const struct nlattr *nla) +{ + return *(__be16 *) nla_data(nla); +} + +/** + * nla_get_le16 - return payload of __le16 attribute + * @nla: __le16 netlink attribute + */ +static inline __le16 nla_get_le16(const struct nlattr *nla) +{ + return *(__le16 *) nla_data(nla); +} + +/** + * nla_get_u8 - return payload of u8 attribute + * @nla: u8 netlink attribute + */ +static inline u8 nla_get_u8(const struct nlattr *nla) +{ + return *(u8 *) nla_data(nla); +} + +/** + * nla_get_u64 - return payload of u64 attribute + * @nla: u64 netlink attribute + */ +static inline u64 nla_get_u64(const struct nlattr *nla) +{ + u64 tmp; + + nla_memcpy(&tmp, nla, sizeof(tmp)); + + return tmp; +} + +/** + * nla_get_be64 - return payload of __be64 attribute + * @nla: __be64 netlink attribute + */ +static inline __be64 nla_get_be64(const struct nlattr *nla) +{ + __be64 tmp; + + nla_memcpy(&tmp, nla, sizeof(tmp)); + + return tmp; +} + +/** + * nla_get_le64 - return payload of __le64 attribute + * @nla: __le64 netlink attribute + */ +static inline __le64 nla_get_le64(const struct nlattr *nla) +{ + return *(__le64 *) nla_data(nla); +} + +/** + * nla_get_s32 - return payload of s32 attribute + * @nla: s32 netlink attribute + */ +static inline s32 nla_get_s32(const struct nlattr *nla) +{ + return *(s32 *) nla_data(nla); +} + +/** + * nla_get_s16 - return payload of s16 attribute + * @nla: s16 netlink attribute + */ +static inline s16 nla_get_s16(const struct nlattr *nla) +{ + return *(s16 *) nla_data(nla); +} + +/** + * nla_get_s8 - return payload of s8 attribute + * @nla: s8 netlink attribute + */ +static inline s8 nla_get_s8(const struct nlattr *nla) +{ + return *(s8 *) nla_data(nla); +} + +/** + * nla_get_s64 - return payload of s64 attribute + * @nla: s64 netlink attribute + */ +static inline s64 nla_get_s64(const struct nlattr *nla) +{ + s64 tmp; + + nla_memcpy(&tmp, nla, sizeof(tmp)); + + return tmp; +} + +/** + * nla_get_flag - return payload of flag attribute + * @nla: flag netlink attribute + */ +static inline int nla_get_flag(const struct nlattr *nla) +{ + return !!nla; +} + +/** + * nla_get_msecs - return payload of msecs attribute + * @nla: msecs netlink attribute + * + * Returns the number of milliseconds in jiffies. + */ +static inline unsigned long nla_get_msecs(const struct nlattr *nla) +{ + u64 msecs = nla_get_u64(nla); + + return msecs_to_jiffies((unsigned long) msecs); +} + +/** + * nla_get_in_addr - return payload of IPv4 address attribute + * @nla: IPv4 address netlink attribute + */ +static inline __be32 nla_get_in_addr(const struct nlattr *nla) +{ + return *(__be32 *) nla_data(nla); +} + +/** + * nla_get_in6_addr - return payload of IPv6 address attribute + * @nla: IPv6 address netlink attribute + */ +static inline struct in6_addr nla_get_in6_addr(const struct nlattr *nla) +{ + struct in6_addr tmp; + + nla_memcpy(&tmp, nla, sizeof(tmp)); + return tmp; +} + +/** + * nla_get_bitfield32 - return payload of 32 bitfield attribute + * @nla: nla_bitfield32 attribute + */ +static inline struct nla_bitfield32 nla_get_bitfield32(const struct nlattr *nla) +{ + struct nla_bitfield32 tmp; + + nla_memcpy(&tmp, nla, sizeof(tmp)); + return tmp; +} + +/** + * nla_memdup - duplicate attribute memory (kmemdup) + * @src: netlink attribute to duplicate from + * @gfp: GFP mask + */ +static inline void *nla_memdup(const struct nlattr *src, gfp_t gfp) +{ + return kmemdup(nla_data(src), nla_len(src), gfp); +} + +/** + * nla_nest_start - Start a new level of nested attributes + * @skb: socket buffer to add attributes to + * @attrtype: attribute type of container + * + * Returns the container attribute + */ +static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) +{ + struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb); + + if (nla_put(skb, attrtype, 0, NULL) < 0) + return NULL; + + return start; +} + +/** + * nla_nest_end - Finalize nesting of attributes + * @skb: socket buffer the attributes are stored in + * @start: container attribute + * + * Corrects the container attribute header to include the all + * appeneded attributes. + * + * Returns the total data length of the skb. + */ +static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) +{ + start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start; + return skb->len; +} + +/** + * nla_nest_cancel - Cancel nesting of attributes + * @skb: socket buffer the message is stored in + * @start: container attribute + * + * Removes the container attribute and including all nested + * attributes. Returns -EMSGSIZE + */ +static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) +{ + nlmsg_trim(skb, start); +} + +/** + * nla_validate_nested - Validate a stream of nested attributes + * @start: container attribute + * @maxtype: maximum attribute type to be expected + * @policy: validation policy + * @extack: extended ACK report struct + * + * Validates all attributes in the nested attribute stream against the + * specified policy. Attributes with a type exceeding maxtype will be + * ignored. See documenation of struct nla_policy for more details. + * + * 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) +{ + return nla_validate(nla_data(start), nla_len(start), maxtype, policy, + extack); +} + +/** + * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute + * @skb: socket buffer the message is stored in + * + * Return true if padding is needed to align the next attribute (nla_data()) to + * a 64-bit aligned area. + */ +static inline bool nla_need_padding_for_64bit(struct sk_buff *skb) +{ +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + /* The nlattr header is 4 bytes in size, that's why we test + * if the skb->data _is_ aligned. A NOP attribute, plus + * nlattr header for next attribute, will make nla_data() + * 8-byte aligned. + */ + if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8)) + return true; +#endif + return false; +} + +/** + * nla_align_64bit - 64-bit align the nla_data() of next attribute + * @skb: socket buffer the message is stored in + * @padattr: attribute type for the padding + * + * Conditionally emit a padding netlink attribute in order to make + * the next attribute we emit have a 64-bit aligned nla_data() area. + * This will only be done in architectures which do not have + * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS defined. + * + * Returns zero on success or a negative error code. + */ +static inline int nla_align_64bit(struct sk_buff *skb, int padattr) +{ + if (nla_need_padding_for_64bit(skb) && + !nla_reserve(skb, padattr, 0)) + return -EMSGSIZE; + + return 0; +} + +/** + * nla_total_size_64bit - total length of attribute including padding + * @payload: length of payload + */ +static inline int nla_total_size_64bit(int payload) +{ + return NLA_ALIGN(nla_attr_size(payload)) +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + + NLA_ALIGN(nla_attr_size(0)) +#endif + ; +} + +/** + * nla_for_each_attr - iterate over a stream of attributes + * @pos: loop counter, set to current attribute + * @head: head of attribute stream + * @len: length of attribute stream + * @rem: initialized to len, holds bytes currently remaining in stream + */ +#define nla_for_each_attr(pos, head, len, rem) \ + for (pos = head, rem = len; \ + nla_ok(pos, rem); \ + pos = nla_next(pos, &(rem))) + +/** + * nla_for_each_nested - iterate over nested attributes + * @pos: loop counter, set to current attribute + * @nla: attribute containing the nested attributes + * @rem: initialized to len, holds bytes currently remaining in stream + */ +#define nla_for_each_nested(pos, nla, rem) \ + nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) + +/** + * nla_is_last - Test if attribute is last in stream + * @nla: attribute to test + * @rem: bytes remaining in stream + */ +static inline bool nla_is_last(const struct nlattr *nla, int rem) +{ + return nla->nla_len == rem; +} + +#endif |