mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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4b6cc7284d
The documentation for how the length of attributes
is checked is wrong ("Exact length" isn't true, the
policy checks are for "minimum length") and a bit
misleading. Make it more complete and explain what
really happens.
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1107 lines
32 KiB
C
1107 lines
32 KiB
C
#ifndef __NET_NETLINK_H
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#define __NET_NETLINK_H
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#include <linux/types.h>
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#include <linux/netlink.h>
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#include <linux/jiffies.h>
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/* ========================================================================
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* Netlink Messages and Attributes Interface (As Seen On TV)
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* ------------------------------------------------------------------------
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* Messages Interface
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* ------------------------------------------------------------------------
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*
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* Message Format:
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* <--- nlmsg_total_size(payload) --->
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* <-- nlmsg_msg_size(payload) ->
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* +----------+- - -+-------------+- - -+-------- - -
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* | nlmsghdr | Pad | Payload | Pad | nlmsghdr
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* +----------+- - -+-------------+- - -+-------- - -
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* nlmsg_data(nlh)---^ ^
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* nlmsg_next(nlh)-----------------------+
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*
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* Payload Format:
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* <---------------------- nlmsg_len(nlh) --------------------->
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* <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) ->
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* +----------------------+- - -+--------------------------------+
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* | Family Header | Pad | Attributes |
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* +----------------------+- - -+--------------------------------+
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* nlmsg_attrdata(nlh, hdrlen)---^
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*
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* Data Structures:
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* struct nlmsghdr netlink message header
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*
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* Message Construction:
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* nlmsg_new() create a new netlink message
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* nlmsg_put() add a netlink message to an skb
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* nlmsg_put_answer() callback based nlmsg_put()
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* nlmsg_end() finalize netlink message
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* nlmsg_get_pos() return current position in message
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* nlmsg_trim() trim part of message
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* nlmsg_cancel() cancel message construction
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* nlmsg_free() free a netlink message
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*
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* Message Sending:
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* nlmsg_multicast() multicast message to several groups
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* nlmsg_unicast() unicast a message to a single socket
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* nlmsg_notify() send notification message
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*
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* Message Length Calculations:
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* nlmsg_msg_size(payload) length of message w/o padding
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* nlmsg_total_size(payload) length of message w/ padding
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* nlmsg_padlen(payload) length of padding at tail
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*
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* Message Payload Access:
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* nlmsg_data(nlh) head of message payload
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* nlmsg_len(nlh) length of message payload
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* nlmsg_attrdata(nlh, hdrlen) head of attributes data
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* nlmsg_attrlen(nlh, hdrlen) length of attributes data
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*
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* Message Parsing:
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* nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes?
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* nlmsg_next(nlh, remaining) get next netlink message
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* nlmsg_parse() parse attributes of a message
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* nlmsg_find_attr() find an attribute in a message
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* nlmsg_for_each_msg() loop over all messages
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* nlmsg_validate() validate netlink message incl. attrs
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* nlmsg_for_each_attr() loop over all attributes
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*
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* Misc:
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* nlmsg_report() report back to application?
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*
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* ------------------------------------------------------------------------
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* Attributes Interface
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* ------------------------------------------------------------------------
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*
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* Attribute Format:
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* <------- nla_total_size(payload) ------->
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* <---- nla_attr_size(payload) ----->
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* +----------+- - -+- - - - - - - - - +- - -+-------- - -
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* | Header | Pad | Payload | Pad | Header
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* +----------+- - -+- - - - - - - - - +- - -+-------- - -
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* <- nla_len(nla) -> ^
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* nla_data(nla)----^ |
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* nla_next(nla)-----------------------------'
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*
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* Data Structures:
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* struct nlattr netlink attribute header
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*
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* Attribute Construction:
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* nla_reserve(skb, type, len) reserve room for an attribute
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* nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr
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* nla_put(skb, type, len, data) add attribute to skb
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* nla_put_nohdr(skb, len, data) add attribute w/o hdr
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* nla_append(skb, len, data) append data to skb
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*
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* Attribute Construction for Basic Types:
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* nla_put_u8(skb, type, value) add u8 attribute to skb
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* nla_put_u16(skb, type, value) add u16 attribute to skb
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* nla_put_u32(skb, type, value) add u32 attribute to skb
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* nla_put_u64(skb, type, value) add u64 attribute to skb
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* nla_put_string(skb, type, str) add string attribute to skb
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* nla_put_flag(skb, type) add flag attribute to skb
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* nla_put_msecs(skb, type, jiffies) add msecs attribute to skb
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*
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* Exceptions Based Attribute Construction:
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* NLA_PUT(skb, type, len, data) add attribute to skb
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* NLA_PUT_U8(skb, type, value) add u8 attribute to skb
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* NLA_PUT_U16(skb, type, value) add u16 attribute to skb
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* NLA_PUT_U32(skb, type, value) add u32 attribute to skb
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* NLA_PUT_U64(skb, type, value) add u64 attribute to skb
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* NLA_PUT_STRING(skb, type, str) add string attribute to skb
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* NLA_PUT_FLAG(skb, type) add flag attribute to skb
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* NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb
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*
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* The meaning of these functions is equal to their lower case
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* variants but they jump to the label nla_put_failure in case
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* of a failure.
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*
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* Nested Attributes Construction:
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* nla_nest_start(skb, type) start a nested attribute
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* nla_nest_end(skb, nla) finalize a nested attribute
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* nla_nest_cancel(skb, nla) cancel nested attribute construction
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*
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* Attribute Length Calculations:
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* nla_attr_size(payload) length of attribute w/o padding
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* nla_total_size(payload) length of attribute w/ padding
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* nla_padlen(payload) length of padding
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*
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* Attribute Payload Access:
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* nla_data(nla) head of attribute payload
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* nla_len(nla) length of attribute payload
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*
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* Attribute Payload Access for Basic Types:
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* nla_get_u8(nla) get payload for a u8 attribute
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* nla_get_u16(nla) get payload for a u16 attribute
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* nla_get_u32(nla) get payload for a u32 attribute
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* nla_get_u64(nla) get payload for a u64 attribute
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* nla_get_flag(nla) return 1 if flag is true
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* nla_get_msecs(nla) get payload for a msecs attribute
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*
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* Attribute Misc:
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* nla_memcpy(dest, nla, count) copy attribute into memory
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* nla_memcmp(nla, data, size) compare attribute with memory area
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* nla_strlcpy(dst, nla, size) copy attribute to a sized string
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* nla_strcmp(nla, str) compare attribute with string
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*
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* Attribute Parsing:
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* nla_ok(nla, remaining) does nla fit into remaining bytes?
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* nla_next(nla, remaining) get next netlink attribute
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* nla_validate() validate a stream of attributes
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* nla_validate_nested() validate a stream of nested attributes
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* nla_find() find attribute in stream of attributes
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* nla_find_nested() find attribute in nested attributes
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* nla_parse() parse and validate stream of attrs
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* nla_parse_nested() parse nested attribuets
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* nla_for_each_attr() loop over all attributes
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* nla_for_each_nested() loop over the nested attributes
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*=========================================================================
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*/
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/**
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* Standard attribute types to specify validation policy
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*/
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enum {
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NLA_UNSPEC,
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NLA_U8,
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NLA_U16,
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NLA_U32,
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NLA_U64,
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NLA_STRING,
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NLA_FLAG,
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NLA_MSECS,
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NLA_NESTED,
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NLA_NESTED_COMPAT,
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NLA_NUL_STRING,
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NLA_BINARY,
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__NLA_TYPE_MAX,
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};
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#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
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/**
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* struct nla_policy - attribute validation policy
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* @type: Type of attribute or NLA_UNSPEC
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* @len: Type specific length of payload
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*
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* Policies are defined as arrays of this struct, the array must be
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* accessible by attribute type up to the highest identifier to be expected.
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*
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* Meaning of `len' field:
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* NLA_STRING Maximum length of string
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* NLA_NUL_STRING Maximum length of string (excluding NUL)
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* NLA_FLAG Unused
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* NLA_BINARY Maximum length of attribute payload
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* NLA_NESTED Don't use `len' field -- length verification is
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* done by checking len of nested header (or empty)
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* NLA_NESTED_COMPAT Minimum length of structure payload
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* NLA_U8, NLA_U16,
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* NLA_U32, NLA_U64,
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* NLA_MSECS Leaving the length field zero will verify the
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* given type fits, using it verifies minimum length
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* just like "All other"
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* All other Minimum length of attribute payload
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*
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* Example:
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* static const struct nla_policy my_policy[ATTR_MAX+1] = {
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* [ATTR_FOO] = { .type = NLA_U16 },
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* [ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
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* [ATTR_BAZ] = { .len = sizeof(struct mystruct) },
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* };
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*/
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struct nla_policy {
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u16 type;
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u16 len;
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};
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/**
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* struct nl_info - netlink source information
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* @nlh: Netlink message header of original request
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* @pid: Netlink PID of requesting application
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*/
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struct nl_info {
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struct nlmsghdr *nlh;
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struct net *nl_net;
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u32 pid;
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};
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extern int netlink_rcv_skb(struct sk_buff *skb,
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int (*cb)(struct sk_buff *,
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struct nlmsghdr *));
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extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb,
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u32 pid, unsigned int group, int report,
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gfp_t flags);
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extern int nla_validate(const struct nlattr *head,
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int len, int maxtype,
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const struct nla_policy *policy);
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extern int nla_parse(struct nlattr **tb, int maxtype,
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const struct nlattr *head, int len,
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const struct nla_policy *policy);
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extern int nla_policy_len(const struct nla_policy *, int);
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extern struct nlattr * nla_find(const struct nlattr *head,
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int len, int attrtype);
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extern size_t nla_strlcpy(char *dst, const struct nlattr *nla,
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size_t dstsize);
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extern int nla_memcpy(void *dest, const struct nlattr *src, int count);
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extern int nla_memcmp(const struct nlattr *nla, const void *data,
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size_t size);
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extern int nla_strcmp(const struct nlattr *nla, const char *str);
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extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype,
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int attrlen);
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extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
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extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype,
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int attrlen);
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extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
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extern void __nla_put(struct sk_buff *skb, int attrtype,
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int attrlen, const void *data);
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extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen,
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const void *data);
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extern int nla_put(struct sk_buff *skb, int attrtype,
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int attrlen, const void *data);
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extern int nla_put_nohdr(struct sk_buff *skb, int attrlen,
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const void *data);
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extern int nla_append(struct sk_buff *skb, int attrlen,
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const void *data);
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/**************************************************************************
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* Netlink Messages
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**************************************************************************/
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/**
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* nlmsg_msg_size - length of netlink message not including padding
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* @payload: length of message payload
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*/
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static inline int nlmsg_msg_size(int payload)
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{
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return NLMSG_HDRLEN + payload;
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}
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/**
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* nlmsg_total_size - length of netlink message including padding
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* @payload: length of message payload
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*/
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static inline int nlmsg_total_size(int payload)
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{
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return NLMSG_ALIGN(nlmsg_msg_size(payload));
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}
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/**
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* nlmsg_padlen - length of padding at the message's tail
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* @payload: length of message payload
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*/
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static inline int nlmsg_padlen(int payload)
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{
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return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
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}
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/**
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* nlmsg_data - head of message payload
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* @nlh: netlink message header
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*/
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static inline void *nlmsg_data(const struct nlmsghdr *nlh)
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{
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return (unsigned char *) nlh + NLMSG_HDRLEN;
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}
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/**
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* nlmsg_len - length of message payload
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* @nlh: netlink message header
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*/
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static inline int nlmsg_len(const struct nlmsghdr *nlh)
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{
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return nlh->nlmsg_len - NLMSG_HDRLEN;
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}
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/**
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* nlmsg_attrdata - head of attributes data
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* @nlh: netlink message header
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* @hdrlen: length of family specific header
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*/
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static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh,
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int hdrlen)
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{
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unsigned char *data = nlmsg_data(nlh);
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return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
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}
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/**
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* nlmsg_attrlen - length of attributes data
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* @nlh: netlink message header
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* @hdrlen: length of family specific header
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*/
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static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
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{
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return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
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}
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/**
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* nlmsg_ok - check if the netlink message fits into the remaining bytes
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* @nlh: netlink message header
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* @remaining: number of bytes remaining in message stream
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*/
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static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
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{
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return (remaining >= (int) sizeof(struct nlmsghdr) &&
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nlh->nlmsg_len >= sizeof(struct nlmsghdr) &&
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nlh->nlmsg_len <= remaining);
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}
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/**
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* nlmsg_next - next netlink message in message stream
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* @nlh: netlink message header
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* @remaining: number of bytes remaining in message stream
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*
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* Returns the next netlink message in the message stream and
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* decrements remaining by the size of the current message.
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*/
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static inline struct nlmsghdr *
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nlmsg_next(const struct nlmsghdr *nlh, int *remaining)
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{
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int totlen = NLMSG_ALIGN(nlh->nlmsg_len);
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*remaining -= totlen;
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return (struct nlmsghdr *) ((unsigned char *) nlh + totlen);
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}
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/**
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* nlmsg_parse - parse attributes of a netlink message
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* @nlh: netlink message header
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* @hdrlen: length of family specific header
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* @tb: destination array with maxtype+1 elements
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* @maxtype: maximum attribute type to be expected
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* @policy: validation policy
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*
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* See nla_parse()
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*/
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static inline int nlmsg_parse(const struct nlmsghdr *nlh, int hdrlen,
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struct nlattr *tb[], int maxtype,
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const struct nla_policy *policy)
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{
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if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
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return -EINVAL;
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return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen),
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nlmsg_attrlen(nlh, hdrlen), policy);
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}
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/**
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* nlmsg_find_attr - find a specific attribute in a netlink message
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* @nlh: netlink message header
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* @hdrlen: length of familiy specific header
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* @attrtype: type of attribute to look for
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*
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* Returns the first attribute which matches the specified type.
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*/
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static inline struct nlattr *nlmsg_find_attr(const struct nlmsghdr *nlh,
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int hdrlen, int attrtype)
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{
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return nla_find(nlmsg_attrdata(nlh, hdrlen),
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nlmsg_attrlen(nlh, hdrlen), attrtype);
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}
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/**
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* nlmsg_validate - validate a netlink message including attributes
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* @nlh: netlinket message header
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* @hdrlen: length of familiy specific header
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* @maxtype: maximum attribute type to be expected
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* @policy: validation policy
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*/
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static inline int nlmsg_validate(const struct nlmsghdr *nlh,
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int hdrlen, int maxtype,
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const struct nla_policy *policy)
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{
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if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
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return -EINVAL;
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return nla_validate(nlmsg_attrdata(nlh, hdrlen),
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nlmsg_attrlen(nlh, hdrlen), maxtype, policy);
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}
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/**
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* nlmsg_report - need to report back to application?
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* @nlh: netlink message header
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*
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* Returns 1 if a report back to the application is requested.
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*/
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static inline int nlmsg_report(const struct nlmsghdr *nlh)
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{
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return !!(nlh->nlmsg_flags & NLM_F_ECHO);
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}
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/**
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* nlmsg_for_each_attr - iterate over a stream of attributes
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* @pos: loop counter, set to current attribute
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* @nlh: netlink message header
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* @hdrlen: length of familiy specific header
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* @rem: initialized to len, holds bytes currently remaining in stream
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*/
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#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
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nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
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nlmsg_attrlen(nlh, hdrlen), rem)
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#if 0
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/* FIXME: Enable once all users have been converted */
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/**
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* __nlmsg_put - Add a new netlink message to an skb
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* @skb: socket buffer to store message in
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* @pid: netlink process id
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* @seq: sequence number of message
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* @type: message type
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* @payload: length of message payload
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* @flags: message flags
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*
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* The caller is responsible to ensure that the skb provides enough
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|
* tailroom for both the netlink header and payload.
|
|
*/
|
|
static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid,
|
|
u32 seq, int type, int payload,
|
|
int flags)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
|
|
nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload));
|
|
nlh->nlmsg_type = type;
|
|
nlh->nlmsg_len = nlmsg_msg_size(payload);
|
|
nlh->nlmsg_flags = flags;
|
|
nlh->nlmsg_pid = pid;
|
|
nlh->nlmsg_seq = seq;
|
|
|
|
memset((unsigned char *) nlmsg_data(nlh) + payload, 0,
|
|
nlmsg_padlen(payload));
|
|
|
|
return nlh;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* nlmsg_put - Add a new netlink message to an skb
|
|
* @skb: socket buffer to store message in
|
|
* @pid: netlink process id
|
|
* @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 pid, u32 seq,
|
|
int type, int payload, int flags)
|
|
{
|
|
if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload)))
|
|
return NULL;
|
|
|
|
return __nlmsg_put(skb, pid, 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).pid, 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.
|
|
*
|
|
* Returns the total data length of the skb.
|
|
*/
|
|
static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
|
|
|
|
return skb->len;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
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
|
|
* @pid: own netlink pid 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 pid, unsigned int group, gfp_t flags)
|
|
{
|
|
int err;
|
|
|
|
NETLINK_CB(skb).dst_group = group;
|
|
|
|
err = netlink_broadcast(sk, skb, pid, 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
|
|
* @pid: netlink pid of the destination socket
|
|
*/
|
|
static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid)
|
|
{
|
|
int err;
|
|
|
|
err = netlink_unicast(sk, skb, pid, 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)
|
|
{
|
|
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
|
|
*
|
|
* See nla_parse()
|
|
*/
|
|
static inline int nla_parse_nested(struct nlattr *tb[], int maxtype,
|
|
const struct nlattr *nla,
|
|
const struct nla_policy *policy)
|
|
{
|
|
return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
return nla_put(skb, attrtype, sizeof(u8), &value);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
return nla_put(skb, attrtype, sizeof(u16), &value);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
return nla_put(skb, attrtype, sizeof(u32), &value);
|
|
}
|
|
|
|
/**
|
|
* nla_put_64 - Add a u64 netlink attribute to a socket buffer
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrtype: attribute type
|
|
* @value: numeric value
|
|
*/
|
|
static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value)
|
|
{
|
|
return nla_put(skb, attrtype, sizeof(u64), &value);
|
|
}
|
|
|
|
/**
|
|
* 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 socket buffer
|
|
* @skb: socket buffer to add attribute to
|
|
* @attrtype: attribute type
|
|
* @jiffies: number of msecs in jiffies
|
|
*/
|
|
static inline int nla_put_msecs(struct sk_buff *skb, int attrtype,
|
|
unsigned long jiffies)
|
|
{
|
|
u64 tmp = jiffies_to_msecs(jiffies);
|
|
return nla_put(skb, attrtype, sizeof(u64), &tmp);
|
|
}
|
|
|
|
#define NLA_PUT(skb, attrtype, attrlen, data) \
|
|
do { \
|
|
if (unlikely(nla_put(skb, attrtype, attrlen, data) < 0)) \
|
|
goto nla_put_failure; \
|
|
} while(0)
|
|
|
|
#define NLA_PUT_TYPE(skb, type, attrtype, value) \
|
|
do { \
|
|
type __tmp = value; \
|
|
NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \
|
|
} while(0)
|
|
|
|
#define NLA_PUT_U8(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, u8, attrtype, value)
|
|
|
|
#define NLA_PUT_U16(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, u16, attrtype, value)
|
|
|
|
#define NLA_PUT_LE16(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, __le16, attrtype, value)
|
|
|
|
#define NLA_PUT_BE16(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, __be16, attrtype, value)
|
|
|
|
#define NLA_PUT_NET16(skb, attrtype, value) \
|
|
NLA_PUT_BE16(skb, attrtype | NLA_F_NET_BYTEORDER, value)
|
|
|
|
#define NLA_PUT_U32(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, u32, attrtype, value)
|
|
|
|
#define NLA_PUT_BE32(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, __be32, attrtype, value)
|
|
|
|
#define NLA_PUT_NET32(skb, attrtype, value) \
|
|
NLA_PUT_BE32(skb, attrtype | NLA_F_NET_BYTEORDER, value)
|
|
|
|
#define NLA_PUT_U64(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, u64, attrtype, value)
|
|
|
|
#define NLA_PUT_BE64(skb, attrtype, value) \
|
|
NLA_PUT_TYPE(skb, __be64, attrtype, value)
|
|
|
|
#define NLA_PUT_NET64(skb, attrtype, value) \
|
|
NLA_PUT_BE64(skb, attrtype | NLA_F_NET_BYTEORDER, value)
|
|
|
|
#define NLA_PUT_STRING(skb, attrtype, value) \
|
|
NLA_PUT(skb, attrtype, strlen(value) + 1, value)
|
|
|
|
#define NLA_PUT_FLAG(skb, attrtype) \
|
|
NLA_PUT(skb, attrtype, 0, NULL)
|
|
|
|
#define NLA_PUT_MSECS(skb, attrtype, jiffies) \
|
|
NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies))
|
|
|
|
/**
|
|
* 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_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_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_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
|
|
*
|
|
* 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)
|
|
{
|
|
return nla_validate(nla_data(start), nla_len(start), maxtype, policy);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
|
|
#endif
|