36 lines
1.7 KiB
Plaintext
36 lines
1.7 KiB
Plaintext
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Netlink Protocol Format (RFC3549)
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+-----------------+-+-------------------+-+
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|Netlink Message |P| Generic Netlink |P|
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| Header |A| Message Header |A|
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|(struct nlmsghdr)|D|(struct genlmsghdr)|D|
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+-----------------+-+-------------------+-+
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+-----------------+-+-----------------+-+-----------------+-+-----------------+-+---+
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|Netlink Attribute|P|Netlink Attribute|P|Netlink Attribute|P|Netlink Attribute|P|...|
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| #0 Header |A| #0 Payload |A| #1 Header |A| #1 Payload |A| |
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| (struct nlattr) |D| (void) |D| (struct nlattr) |D| (void) |D| |
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+-----------------+-+-----------------+-+-----------------+-+-----------------+-+---+
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* Each netlink message consists of a bitstream with a netlink header.
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* After this header a second header *can* be used specific to the netlink
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family in use. This library was tested using the generic netlink
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protocol defined by struct genlmsghdr to support nl80211.
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* After the header(s) netlink attributes can be appended to the message
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which hold can hold basic types such as unsigned integers and strings.
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* All data structures in this implementation are byte-aligned (Currently 4 bytes).
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* Acknowledgements (ACKs) are sent as NLMSG_ERROR netlink message types (0x2) and
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have an error value of 0.
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KNOWN BUGS
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* NOT THREAD SAFE!!!
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* nla_parse - does not use nla_policy argument
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* nl_recvmsgs - does not support nl_cb_overwrite_recv()
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* nl_recv - sets/unsets async. flag
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* genl_ctrl_alloc_cache - netlink send/recv funcs should be used
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REFERENCES
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* nl80211.h
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* netlink_types.h
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* $LINUX_KERNEL/net/wireless/nl80211.c
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* http://www.infradead.org/~tgr/libnl/doc-3.0/index.html
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* http://www.netfilter.org/projects/libmnl/doxygen/index.html
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