1003 lines
24 KiB
C
1003 lines
24 KiB
C
/*
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* lib/msg.c Netlink Messages Interface
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation version 2.1
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* of the License.
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*
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* Copyright (c) 2003-2006 Thomas Graf <tgraf@suug.ch>
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*/
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/**
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* @ingroup nl
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* @defgroup msg Messages
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* Netlink Message Construction/Parsing Interface
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*
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* The following information is partly extracted from RFC3549
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* (ftp://ftp.rfc-editor.org/in-notes/rfc3549.txt)
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*
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* @par Message Format
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* Netlink messages consist of a byte stream with one or multiple
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* Netlink headers and an associated payload. If the payload is too big
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* to fit into a single message it, can be split over multiple Netlink
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* messages, collectively called a multipart message. For multipart
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* messages, the first and all following headers have the \c NLM_F_MULTI
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* Netlink header flag set, except for the last header which has the
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* Netlink header type \c NLMSG_DONE.
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*
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* @par
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* The Netlink message header (\link nlmsghdr struct nlmsghdr\endlink) is shown below.
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* @code
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Length |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Type | Flags |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Sequence Number |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Process ID (PID) |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* @endcode
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*
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* @par
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* The netlink message header and payload must be aligned properly:
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* @code
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* <------- NLMSG_ALIGN(hlen) ------> <---- NLMSG_ALIGN(len) --->
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* +----------------------------+- - -+- - - - - - - - - - -+- - -+
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* | Header | Pad | Payload | Pad |
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* | struct nlmsghdr | | | |
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* +----------------------------+- - -+- - - - - - - - - - -+- - -+
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* @endcode
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* @par
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* Message Format:
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* @code
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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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* @endcode
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* @par
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* The payload may consist of arbitary data but may have strict
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* alignment and formatting rules depening on the specific netlink
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* families.
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* @par
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* @code
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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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* @endcode
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* @par The ACK Netlink Message
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* This message is actually used to denote both an ACK and a NACK.
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* Typically, the direction is from FEC to CPC (in response to an ACK
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* request message). However, the CPC should be able to send ACKs back
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* to FEC when requested.
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* @code
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Netlink message header |
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* | type = NLMSG_ERROR |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Error code |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | OLD Netlink message header |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* @endcode
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*
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* @par Example
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* @code
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* // Various methods exist to create/allocate a new netlink
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* // message.
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* //
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* // nlmsg_alloc() will allocate an empty netlink message with
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* // a maximum payload size which defaults to the page size of
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* // the system. This default size can be modified using the
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* // function nlmsg_set_default_size().
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* struct nl_msg *msg = nlmsg_alloc();
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*
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* // Very often, the message type and message flags are known
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* // at allocation time while the other fields are auto generated:
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* struct nl_msg *msg = nlmsg_alloc_simple(MY_TYPE, MY_FLAGS);
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*
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* // Alternatively an existing netlink message header can be used
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* // to inherit the header values:
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* struct nlmsghdr hdr = {
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* .nlmsg_type = MY_TYPE,
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* .nlmsg_flags = MY_FLAGS,
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* };
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* struct nl_msg *msg = nlmsg_inherit(&hdr);
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*
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* // Last but not least, netlink messages received from netlink sockets
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* // can be converted into nl_msg objects using nlmsg_convert(). This
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* // will create a message with a maximum payload size which equals the
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* // length of the existing netlink message, therefore no more data can
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* // be appened without calling nlmsg_expand() first.
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* struct nl_msg *msg = nlmsg_convert(nlh_from_nl_sock);
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*
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* // Payload may be added to the message via nlmsg_append(). The fourth
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* // parameter specifies the number of alignment bytes the data should
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* // be padding with at the end. Common values are 0 to disable it or
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* // NLMSG_ALIGNTO to ensure proper netlink message padding.
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* nlmsg_append(msg, &mydata, sizeof(mydata), 0);
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*
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* // Sometimes it may be necessary to reserve room for data but defer
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* // the actual copying to a later point, nlmsg_reserve() can be used
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* // for this purpose:
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* void *data = nlmsg_reserve(msg, sizeof(mydata), NLMSG_ALIGNTO);
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*
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* // Attributes may be added using the attributes interface.
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*
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* // After successful use of the message, the memory must be freed
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* // using nlmsg_free()
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* nlmsg_free(msg);
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* @endcode
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*
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* @par 4) Parsing messages
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* @code
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* int n;
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* unsigned char *buf;
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* struct nlmsghdr *hdr;
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*
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* n = nl_recv(handle, NULL, &buf);
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*
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* hdr = (struct nlmsghdr *) buf;
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* while (nlmsg_ok(hdr, n)) {
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* // Process message here...
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* hdr = nlmsg_next(hdr, &n);
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* }
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* @endcode
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* @{
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*/
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#include <netlink-local.h>
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#include <netlink/netlink.h>
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#include <netlink/utils.h>
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#include <netlink/cache.h>
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#include <netlink/attr.h>
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#include <linux/socket.h>
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static size_t default_msg_size;
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static void __init init_msg_size(void)
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{
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default_msg_size = getpagesize();
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}
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/**
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* @name Size Calculations
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* @{
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*/
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/**
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* length of netlink message not including padding
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* @arg payload length of message payload
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*/
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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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* length of netlink message including padding
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* @arg payload length of message payload
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*/
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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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* length of padding at the message's tail
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* @arg payload length of message payload
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*/
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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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/**
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* @name Payload Access
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* @{
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*/
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/**
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* head of message payload
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* @arg nlh netlink messsage header
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*/
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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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void *nlmsg_tail(const struct nlmsghdr *nlh)
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{
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return (unsigned char *) nlh + NLMSG_ALIGN(nlh->nlmsg_len);
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}
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/**
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* length of message payload
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* @arg nlh netlink message header
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*/
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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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/**
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* @name Attribute Access
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* @{
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*/
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/**
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* head of attributes data
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* @arg nlh netlink message header
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* @arg hdrlen length of family specific header
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*/
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struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, 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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* length of attributes data
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* @arg nlh netlink message header
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* @arg hdrlen length of family specific header
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*/
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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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/**
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* @name Message Parsing
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* @{
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*/
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int nlmsg_valid_hdr(const struct nlmsghdr *nlh, int hdrlen)
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{
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if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
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return 0;
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return 1;
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}
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/**
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* check if the netlink message fits into the remaining bytes
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* @arg nlh netlink message header
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* @arg remaining number of bytes remaining in message stream
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*/
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int nlmsg_ok(const struct nlmsghdr *nlh, int remaining)
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{
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return (remaining >= 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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* next netlink message in message stream
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* @arg nlh netlink message header
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* @arg 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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struct nlmsghdr *nlmsg_next(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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* parse attributes of a netlink message
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* @arg nlh netlink message header
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* @arg hdrlen length of family specific header
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* @arg tb destination array with maxtype+1 elements
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* @arg maxtype maximum attribute type to be expected
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* @arg policy validation policy
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*
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* See nla_parse()
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*/
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int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[],
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int maxtype, struct nla_policy *policy)
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{
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if (!nlmsg_valid_hdr(nlh, hdrlen))
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return nl_errno(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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* @arg nlh netlink message header
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* @arg hdrlen length of familiy specific header
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* @arg 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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struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh, 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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* @arg nlh netlinket message header
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* @arg hdrlen length of familiy specific header
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* @arg maxtype maximum attribute type to be expected
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* @arg policy validation policy
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*/
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int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,
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struct nla_policy *policy)
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{
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if (!nlmsg_valid_hdr(nlh, hdrlen))
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return nl_errno(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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/**
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* @name Message Building/Access
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* @{
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*/
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static struct nl_msg *__nlmsg_alloc(size_t len)
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{
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struct nl_msg *nm;
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nm = calloc(1, sizeof(*nm));
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if (!nm)
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goto errout;
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nm->nm_nlh = calloc(1, len);
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if (!nm->nm_nlh)
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goto errout;
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nm->nm_protocol = -1;
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nm->nm_size = len;
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nm->nm_nlh->nlmsg_len = nlmsg_total_size(0);
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NL_DBG(2, "msg %p: Allocated new message, maxlen=%zu\n", nm, len);
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return nm;
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errout:
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free(nm);
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nl_errno(ENOMEM);
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return NULL;
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}
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/**
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* Allocate a new netlink message with the default maximum payload size.
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*
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* Allocates a new netlink message without any further payload. The
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* maximum payload size defaults to PAGESIZE or as otherwise specified
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* with nlmsg_set_default_size().
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*
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* @return Newly allocated netlink message or NULL.
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*/
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struct nl_msg *nlmsg_alloc(void)
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{
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return __nlmsg_alloc(default_msg_size);
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}
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/**
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* Allocate a new netlink message with maximum payload size specified.
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*/
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struct nl_msg *nlmsg_alloc_size(size_t max)
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{
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return __nlmsg_alloc(max);
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}
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/**
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* Allocate a new netlink message and inherit netlink message header
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* @arg hdr Netlink message header template
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*
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* Allocates a new netlink message and inherits the original message
|
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* header. If \a hdr is not NULL it will be used as a template for
|
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* the netlink message header, otherwise the header is left blank.
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*
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* @return Newly allocated netlink message or NULL
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*/
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struct nl_msg *nlmsg_inherit(struct nlmsghdr *hdr)
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{
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struct nl_msg *nm;
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|
|
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nm = nlmsg_alloc();
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if (nm && hdr) {
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struct nlmsghdr *new = nm->nm_nlh;
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new->nlmsg_type = hdr->nlmsg_type;
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new->nlmsg_flags = hdr->nlmsg_flags;
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new->nlmsg_seq = hdr->nlmsg_seq;
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new->nlmsg_pid = hdr->nlmsg_pid;
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}
|
|
|
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return nm;
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}
|
|
|
|
/**
|
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* Allocate a new netlink message
|
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* @arg nlmsgtype Netlink message type
|
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* @arg flags Message flags.
|
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*
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* @return Newly allocated netlink message or NULL.
|
|
*/
|
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struct nl_msg *nlmsg_alloc_simple(int nlmsgtype, int flags)
|
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{
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struct nl_msg *msg;
|
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struct nlmsghdr nlh = {
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.nlmsg_type = nlmsgtype,
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.nlmsg_flags = flags,
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};
|
|
|
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msg = nlmsg_inherit(&nlh);
|
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if (msg)
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NL_DBG(2, "msg %p: Allocated new simple message\n", msg);
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|
|
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return msg;
|
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}
|
|
|
|
/**
|
|
* Set the default maximum message payload size for allocated messages
|
|
* @arg max Size of payload in bytes.
|
|
*/
|
|
void nlmsg_set_default_size(size_t max)
|
|
{
|
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if (max < nlmsg_total_size(0))
|
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max = nlmsg_total_size(0);
|
|
|
|
default_msg_size = max;
|
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}
|
|
|
|
/**
|
|
* Convert a netlink message received from a netlink socket to a nl_msg
|
|
* @arg hdr Netlink message received from netlink socket.
|
|
*
|
|
* Allocates a new netlink message and copies all of the data pointed to
|
|
* by \a hdr into the new message object.
|
|
*
|
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* @return Newly allocated netlink message or NULL.
|
|
*/
|
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struct nl_msg *nlmsg_convert(struct nlmsghdr *hdr)
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{
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struct nl_msg *nm;
|
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|
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nm = __nlmsg_alloc(NLMSG_ALIGN(hdr->nlmsg_len));
|
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if (!nm)
|
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goto errout;
|
|
|
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memcpy(nm->nm_nlh, hdr, hdr->nlmsg_len);
|
|
|
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return nm;
|
|
errout:
|
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nlmsg_free(nm);
|
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return NULL;
|
|
}
|
|
|
|
/**
|
|
* Reserve room for additional data in a netlink message
|
|
* @arg n netlink message
|
|
* @arg len length of additional data to reserve room for
|
|
* @arg pad number of bytes to align data to
|
|
*
|
|
* Reserves room for additional data at the tail of the an
|
|
* existing netlink message. Eventual padding required will
|
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* be zeroed out.
|
|
*
|
|
* @return Pointer to start of additional data tailroom or NULL.
|
|
*/
|
|
void *nlmsg_reserve(struct nl_msg *n, size_t len, int pad)
|
|
{
|
|
void *buf = n->nm_nlh;
|
|
size_t nlmsg_len = n->nm_nlh->nlmsg_len;
|
|
size_t tlen;
|
|
|
|
tlen = pad ? ((len + (pad - 1)) & ~(pad - 1)) : len;
|
|
|
|
if ((tlen + nlmsg_len) > n->nm_size) {
|
|
nl_errno(ENOBUFS);
|
|
return NULL;
|
|
}
|
|
|
|
buf += nlmsg_len;
|
|
n->nm_nlh->nlmsg_len += tlen;
|
|
|
|
if (tlen > len)
|
|
memset(buf + len, 0, tlen - len);
|
|
|
|
NL_DBG(2, "msg %p: Reserved %zu bytes, pad=%d, nlmsg_len=%d\n",
|
|
n, len, pad, n->nm_nlh->nlmsg_len);
|
|
|
|
return buf;
|
|
}
|
|
|
|
/**
|
|
* Append data to tail of a netlink message
|
|
* @arg n netlink message
|
|
* @arg data data to add
|
|
* @arg len length of data
|
|
* @arg pad Number of bytes to align data to.
|
|
*
|
|
* Extends the netlink message as needed and appends the data of given
|
|
* length to the message.
|
|
*
|
|
* @return 0 on success or a negative error code
|
|
*/
|
|
int nlmsg_append(struct nl_msg *n, void *data, size_t len, int pad)
|
|
{
|
|
void *tmp;
|
|
|
|
tmp = nlmsg_reserve(n, len, pad);
|
|
if (tmp == NULL)
|
|
return nl_errno(ENOMEM);
|
|
|
|
memcpy(tmp, data, len);
|
|
NL_DBG(2, "msg %p: Appended %zu bytes with padding %d\n", n, len, pad);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Expand maximum payload size of a netlink message
|
|
* @arg n Netlink message.
|
|
* @arg newlen New maximum payload size.
|
|
*
|
|
* Reallocates the payload section of a netlink message and increases
|
|
* the maximum payload size of the message.
|
|
*
|
|
* @note Any pointers pointing to old payload block will be stale and
|
|
* need to be refetched. Therfore, do not expand while constructing
|
|
* nested attributes or while reserved data blocks are held.
|
|
*
|
|
* @return 0 on success or a negative error code.
|
|
*/
|
|
int nlmsg_expand(struct nl_msg *n, size_t newlen)
|
|
{
|
|
void *tmp;
|
|
|
|
if (newlen <= n->nm_size)
|
|
return nl_errno(EINVAL);
|
|
|
|
tmp = realloc(n->nm_nlh, newlen);
|
|
if (tmp == NULL)
|
|
return nl_errno(ENOMEM);
|
|
|
|
n->nm_nlh = tmp;
|
|
n->nm_size = newlen;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Add a netlink message header to a netlink message
|
|
* @arg n netlink message
|
|
* @arg pid netlink process id or NL_AUTO_PID
|
|
* @arg seq sequence number of message or NL_AUTO_SEQ
|
|
* @arg type message type
|
|
* @arg payload length of message payload
|
|
* @arg flags message flags
|
|
*
|
|
* Adds or overwrites the netlink message header in an existing message
|
|
* object. If \a payload is greater-than zero additional room will be
|
|
* reserved, f.e. for family specific headers. It can be accesed via
|
|
* nlmsg_data().
|
|
*
|
|
* @return A pointer to the netlink message header or NULL.
|
|
*/
|
|
struct nlmsghdr *nlmsg_put(struct nl_msg *n, uint32_t pid, uint32_t seq,
|
|
int type, int payload, int flags)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
|
|
if (n->nm_nlh->nlmsg_len < NLMSG_HDRLEN)
|
|
BUG();
|
|
|
|
nlh = (struct nlmsghdr *) n->nm_nlh;
|
|
nlh->nlmsg_type = type;
|
|
nlh->nlmsg_flags = flags;
|
|
nlh->nlmsg_pid = pid;
|
|
nlh->nlmsg_seq = seq;
|
|
|
|
NL_DBG(2, "msg %p: Added netlink header type=%d, flags=%d, pid=%d, "
|
|
"seq=%d\n", n, type, flags, pid, seq);
|
|
|
|
if (payload > 0 &&
|
|
nlmsg_reserve(n, payload, NLMSG_ALIGNTO) == NULL)
|
|
return NULL;
|
|
|
|
return nlh;
|
|
}
|
|
|
|
/**
|
|
* Return actual netlink message
|
|
* @arg n netlink message
|
|
*
|
|
* Returns the actual netlink message casted to the type of the netlink
|
|
* message header.
|
|
*
|
|
* @return A pointer to the netlink message.
|
|
*/
|
|
struct nlmsghdr *nlmsg_hdr(struct nl_msg *n)
|
|
{
|
|
return n->nm_nlh;
|
|
}
|
|
|
|
/**
|
|
* Free a netlink message
|
|
* @arg n netlink message
|
|
*
|
|
* Destroys a netlink message and frees up all used memory.
|
|
*
|
|
* @pre The message must be unused.
|
|
*/
|
|
void nlmsg_free(struct nl_msg *n)
|
|
{
|
|
if (!n)
|
|
return;
|
|
|
|
free(n->nm_nlh);
|
|
free(n);
|
|
NL_DBG(2, "msg %p: Freed\n", n);
|
|
}
|
|
|
|
/** @} */
|
|
|
|
/**
|
|
* @name Attributes
|
|
* @{
|
|
*/
|
|
|
|
void nlmsg_set_proto(struct nl_msg *msg, int protocol)
|
|
{
|
|
msg->nm_protocol = protocol;
|
|
}
|
|
|
|
int nlmsg_get_proto(struct nl_msg *msg)
|
|
{
|
|
return msg->nm_protocol;
|
|
}
|
|
|
|
size_t nlmsg_get_max_size(struct nl_msg *msg)
|
|
{
|
|
return msg->nm_size;
|
|
}
|
|
|
|
void nlmsg_set_src(struct nl_msg *msg, struct sockaddr_nl *addr)
|
|
{
|
|
memcpy(&msg->nm_src, addr, sizeof(*addr));
|
|
}
|
|
|
|
struct sockaddr_nl *nlmsg_get_src(struct nl_msg *msg)
|
|
{
|
|
return &msg->nm_src;
|
|
}
|
|
|
|
void nlmsg_set_dst(struct nl_msg *msg, struct sockaddr_nl *addr)
|
|
{
|
|
memcpy(&msg->nm_dst, addr, sizeof(*addr));
|
|
}
|
|
|
|
struct sockaddr_nl *nlmsg_get_dst(struct nl_msg *msg)
|
|
{
|
|
return &msg->nm_dst;
|
|
}
|
|
|
|
void nlmsg_set_creds(struct nl_msg *msg, struct ucred *creds)
|
|
{
|
|
memcpy(&msg->nm_creds, creds, sizeof(*creds));
|
|
msg->nm_flags |= NL_MSG_CRED_PRESENT;
|
|
}
|
|
|
|
struct ucred *nlmsg_get_creds(struct nl_msg *msg)
|
|
{
|
|
if (msg->nm_flags & NL_MSG_CRED_PRESENT)
|
|
return &msg->nm_creds;
|
|
return NULL;
|
|
}
|
|
|
|
/** @} */
|
|
|
|
/**
|
|
* @name Netlink Message Type Translations
|
|
* @{
|
|
*/
|
|
|
|
static struct trans_tbl nl_msgtypes[] = {
|
|
__ADD(NLMSG_NOOP,NOOP)
|
|
__ADD(NLMSG_ERROR,ERROR)
|
|
__ADD(NLMSG_DONE,DONE)
|
|
__ADD(NLMSG_OVERRUN,OVERRUN)
|
|
};
|
|
|
|
char *nl_nlmsgtype2str(int type, char *buf, size_t size)
|
|
{
|
|
return __type2str(type, buf, size, nl_msgtypes,
|
|
ARRAY_SIZE(nl_msgtypes));
|
|
}
|
|
|
|
int nl_str2nlmsgtype(const char *name)
|
|
{
|
|
return __str2type(name, nl_msgtypes, ARRAY_SIZE(nl_msgtypes));
|
|
}
|
|
|
|
/** @} */
|
|
|
|
/**
|
|
* @name Netlink Message Flags Translations
|
|
* @{
|
|
*/
|
|
|
|
char *nl_nlmsg_flags2str(int flags, char *buf, size_t len)
|
|
{
|
|
memset(buf, 0, len);
|
|
|
|
#define PRINT_FLAG(f) \
|
|
if (flags & NLM_F_##f) { \
|
|
flags &= ~NLM_F_##f; \
|
|
strncat(buf, #f, len - strlen(buf) - 1); \
|
|
if (flags) \
|
|
strncat(buf, ",", len - strlen(buf) - 1); \
|
|
}
|
|
|
|
PRINT_FLAG(REQUEST);
|
|
PRINT_FLAG(MULTI);
|
|
PRINT_FLAG(ACK);
|
|
PRINT_FLAG(ECHO);
|
|
PRINT_FLAG(ROOT);
|
|
PRINT_FLAG(MATCH);
|
|
PRINT_FLAG(ATOMIC);
|
|
PRINT_FLAG(REPLACE);
|
|
PRINT_FLAG(EXCL);
|
|
PRINT_FLAG(CREATE);
|
|
PRINT_FLAG(APPEND);
|
|
|
|
if (flags) {
|
|
char s[32];
|
|
snprintf(s, sizeof(s), "0x%x", flags);
|
|
strncat(buf, s, len - strlen(buf) - 1);
|
|
}
|
|
#undef PRINT_FLAG
|
|
|
|
return buf;
|
|
}
|
|
|
|
/** @} */
|
|
|
|
/**
|
|
* @name Direct Parsing
|
|
* @{
|
|
*/
|
|
|
|
/** @cond SKIP */
|
|
struct dp_xdata {
|
|
void (*cb)(struct nl_object *, void *);
|
|
void *arg;
|
|
};
|
|
/** @endcond */
|
|
|
|
static int parse_cb(struct nl_object *obj, struct nl_parser_param *p)
|
|
{
|
|
struct dp_xdata *x = p->pp_arg;
|
|
|
|
x->cb(obj, x->arg);
|
|
return 0;
|
|
}
|
|
|
|
int nl_msg_parse(struct nl_msg *msg, void (*cb)(struct nl_object *, void *),
|
|
void *arg)
|
|
{
|
|
struct nl_cache_ops *ops;
|
|
struct nl_parser_param p = {
|
|
.pp_cb = parse_cb
|
|
};
|
|
struct dp_xdata x = {
|
|
.cb = cb,
|
|
.arg = arg,
|
|
};
|
|
|
|
ops = nl_cache_ops_associate(nlmsg_get_proto(msg),
|
|
nlmsg_hdr(msg)->nlmsg_type);
|
|
if (ops == NULL)
|
|
return nl_error(ENOENT, "Unknown message type %d",
|
|
nlmsg_hdr(msg)->nlmsg_type);
|
|
p.pp_arg = &x;
|
|
|
|
return nl_cache_parse(ops, NULL, nlmsg_hdr(msg), &p);
|
|
}
|
|
|
|
/** @} */
|
|
|
|
/**
|
|
* @name Dumping
|
|
* @{
|
|
*/
|
|
|
|
static void prefix_line(FILE *ofd, int prefix)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < prefix; i++)
|
|
fprintf(ofd, " ");
|
|
}
|
|
|
|
static inline void dump_hex(FILE *ofd, char *start, int len, int prefix)
|
|
{
|
|
int i, a, c, limit;
|
|
char ascii[21] = {0};
|
|
|
|
limit = 18 - (prefix * 2);
|
|
prefix_line(ofd, prefix);
|
|
fprintf(ofd, " ");
|
|
|
|
for (i = 0, a = 0, c = 0; i < len; i++) {
|
|
int v = *(uint8_t *) (start + i);
|
|
|
|
fprintf(ofd, "%02x ", v);
|
|
ascii[a++] = isprint(v) ? v : '.';
|
|
|
|
if (c == limit-1) {
|
|
fprintf(ofd, "%s\n", ascii);
|
|
if (i < (len - 1)) {
|
|
prefix_line(ofd, prefix);
|
|
fprintf(ofd, " ");
|
|
}
|
|
a = c = 0;
|
|
memset(ascii, 0, sizeof(ascii));
|
|
} else
|
|
c++;
|
|
}
|
|
|
|
if (c != 0) {
|
|
for (i = 0; i < (limit - c); i++)
|
|
fprintf(ofd, " ");
|
|
fprintf(ofd, "%s\n", ascii);
|
|
}
|
|
}
|
|
|
|
static void print_hdr(FILE *ofd, struct nl_msg *msg)
|
|
{
|
|
struct nlmsghdr *nlh = nlmsg_hdr(msg);
|
|
struct nl_cache_ops *ops;
|
|
struct nl_msgtype *mt;
|
|
char buf[128];
|
|
|
|
fprintf(ofd, " .nlmsg_len = %d\n", nlh->nlmsg_len);
|
|
|
|
ops = nl_cache_ops_associate(nlmsg_get_proto(msg), nlh->nlmsg_type);
|
|
if (ops) {
|
|
mt = nl_msgtype_lookup(ops, nlh->nlmsg_type);
|
|
if (!mt)
|
|
BUG();
|
|
|
|
snprintf(buf, sizeof(buf), "%s::%s", ops->co_name, mt->mt_name);
|
|
} else
|
|
nl_nlmsgtype2str(nlh->nlmsg_type, buf, sizeof(buf));
|
|
|
|
fprintf(ofd, " .nlmsg_type = %d <%s>\n", nlh->nlmsg_type, buf);
|
|
fprintf(ofd, " .nlmsg_flags = %d <%s>\n", nlh->nlmsg_flags,
|
|
nl_nlmsg_flags2str(nlh->nlmsg_flags, buf, sizeof(buf)));
|
|
fprintf(ofd, " .nlmsg_seq = %d\n", nlh->nlmsg_seq);
|
|
fprintf(ofd, " .nlmsg_pid = %d\n", nlh->nlmsg_pid);
|
|
|
|
}
|
|
|
|
static void dump_attrs(FILE *ofd, struct nlattr *attrs, int attrlen,
|
|
int prefix)
|
|
{
|
|
int rem;
|
|
struct nlattr *nla;
|
|
|
|
nla_for_each_attr(nla, attrs, attrlen, rem) {
|
|
int padlen, alen = nla_len(nla);
|
|
|
|
prefix_line(ofd, prefix);
|
|
fprintf(ofd, " [ATTR %02d%s] %d octets\n", nla_type(nla),
|
|
nla->nla_type & NLA_F_NESTED ? " NESTED" : "",
|
|
alen);
|
|
|
|
if (nla->nla_type & NLA_F_NESTED)
|
|
dump_attrs(ofd, nla_data(nla), alen, prefix+1);
|
|
else
|
|
dump_hex(ofd, nla_data(nla), alen, prefix);
|
|
|
|
padlen = nla_padlen(alen);
|
|
if (padlen > 0) {
|
|
prefix_line(ofd, prefix);
|
|
fprintf(ofd, " [PADDING] %d octets\n",
|
|
padlen);
|
|
dump_hex(ofd, nla_data(nla) + alen,
|
|
padlen, prefix);
|
|
}
|
|
}
|
|
|
|
if (rem) {
|
|
prefix_line(ofd, prefix);
|
|
fprintf(ofd, " [LEFTOVER] %d octets\n", rem);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Dump message in human readable format to file descriptor
|
|
* @arg msg Message to print
|
|
* @arg ofd File descriptor.
|
|
*/
|
|
void nl_msg_dump(struct nl_msg *msg, FILE *ofd)
|
|
{
|
|
struct nlmsghdr *hdr = nlmsg_hdr(msg);
|
|
|
|
fprintf(ofd,
|
|
"-------------------------- BEGIN NETLINK MESSAGE "
|
|
"---------------------------\n");
|
|
|
|
fprintf(ofd, " [HEADER] %Zu octets\n", sizeof(struct nlmsghdr));
|
|
print_hdr(ofd, msg);
|
|
|
|
if (hdr->nlmsg_type == NLMSG_ERROR &&
|
|
hdr->nlmsg_len >= nlmsg_msg_size(sizeof(struct nlmsgerr))) {
|
|
struct nl_msg *errmsg;
|
|
struct nlmsgerr *err = nlmsg_data(hdr);
|
|
|
|
fprintf(ofd, " [ERRORMSG] %Zu octets\n", sizeof(*err));
|
|
fprintf(ofd, " .error = %d \"%s\"\n", err->error,
|
|
strerror(-err->error));
|
|
fprintf(ofd, " [ORIGINAL MESSAGE] %Zu octets\n", sizeof(*hdr));
|
|
|
|
errmsg = nlmsg_inherit(&err->msg);
|
|
print_hdr(ofd, errmsg);
|
|
nlmsg_free(errmsg);
|
|
} else if (nlmsg_len(hdr) > 0) {
|
|
struct nl_cache_ops *ops;
|
|
int payloadlen = nlmsg_len(hdr);
|
|
int attrlen = 0;
|
|
|
|
ops = nl_cache_ops_associate(nlmsg_get_proto(msg),
|
|
hdr->nlmsg_type);
|
|
if (ops) {
|
|
attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize);
|
|
payloadlen -= attrlen;
|
|
}
|
|
|
|
fprintf(ofd, " [PAYLOAD] %d octets\n", payloadlen);
|
|
dump_hex(ofd, nlmsg_data(hdr), payloadlen, 0);
|
|
|
|
if (attrlen) {
|
|
struct nlattr *attrs;
|
|
int attrlen;
|
|
|
|
attrs = nlmsg_attrdata(hdr, ops->co_hdrsize);
|
|
attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize);
|
|
dump_attrs(ofd, attrs, attrlen, 0);
|
|
}
|
|
}
|
|
|
|
fprintf(ofd,
|
|
"--------------------------- END NETLINK MESSAGE "
|
|
"---------------------------\n");
|
|
}
|
|
|
|
/** @} */
|
|
|
|
/** @} */
|