user/sven/linux.git/include/linux/netlink.h, branch v5.4.90

netlink: use 48 byte ctx instead of 6 signed longs for callback

2019-07-02T02:12:10Z

People are inclined to stuff random things into cb->args[n] because it looks like an array of integers. Sometimes people even put u64s in there with comments noting that a certain member takes up two slots. The horror! Really this should mirror the usage of skb->cb, which are just 48 opaque bytes suitable for casting a struct. Then people can create their usual casting macros for accessing strongly typed members of a struct. As a plus, this also gives us the same amount of space on 32bit and 64bit. Signed-off-by: Jason A. Donenfeld Reviewed-by: Johannes Berg Signed-off-by: David S. Miller

net: netlink: add helper to retrieve NETLINK_F_STRICT_CHK

2019-01-19T18:09:58Z

Dumps can read state of the NETLINK_F_STRICT_CHK flag from a field in the callback structure. For non-dump GET requests we need a way to access the state of that flag from a socket. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

linux/netlink.h: drop unnecessary extern prefix

2018-12-21T00:43:54Z

Don't need extern prefix before function prototypes. Checkpatch has complained about this for a couple of years. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

netlink: add nl_set_extack_cookie_u64()

2018-11-09T10:20:07Z

Add a helper function nl_set_extack_cookie_u64() to use a u64 as the netlink extended ACK cookie, to avoid having to open-code it in any users of the cookie. A u64 should be sufficient for most subsystems though we allow for up to 20 bytes right now. This also matches the cookies in nl80211 where I intend to use this. Signed-off-by: Johannes Berg Acked-by: David S. Miller Signed-off-by: Johannes Berg

netlink: Add answer_flags to netlink_callback

2018-10-16T07:13:12Z

With dump filtering we need a way to ensure the NLM_F_DUMP_FILTERED flag is set on a message back to the user if the data returned is influenced by some input attributes. Normally this can be done as messages are added to the skb, but if the filter results in no data being returned, the user could be confused as to why. This patch adds answer_flags to the netlink_callback allowing dump handlers to set the NLM_F_DUMP_FILTERED at a minimum in the NLMSG_DONE message ensuring the flag gets back to the user. The netlink_callback space is initialized to 0 via a memset in __netlink_dump_start, so init of the new answer_flags is covered. Signed-off-by: David Ahern Signed-off-by: David S. Miller

netlink: Add new socket option to enable strict checking on dumps

2018-10-08T17:39:04Z

Add a new socket option, NETLINK_DUMP_STRICT_CHK, that userspace can use via setsockopt to request strict checking of headers and attributes on dump requests. To get dump features such as kernel side filtering based on data in the header or attributes appended to the dump request, userspace must call setsockopt() for NETLINK_DUMP_STRICT_CHK and a non-zero value. Since the netlink sock and its flags are private to the af_netlink code, the strict checking flag is passed to dump handlers via a flag in the netlink_callback struct. For old userspace on new kernel there is no impact as all of the data checks in later patches are wrapped in a check on the new strict flag. For new userspace on old kernel, the setsockopt will fail and even if new userspace sets data in the headers and appended attributes the kernel will silently ignore it. Moving forward when the setsockopt succeeds, the new userspace on old kernel means the dump request can pass an attribute the kernel does not understand. The dump will then fail as the older kernel does not understand it. New userspace on new kernel setting the socket option gets the benefit of the improved data dump. Kernel side the NETLINK_DUMP_STRICT_CHK uapi is converted to a generic NETLINK_F_STRICT_CHK flag which can potentially be leveraged for tighter checking on the NEW, DEL, and SET commands. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller

netlink: Pass extack to dump handlers

2018-10-08T17:39:03Z

Declare extack in netlink_dump and pass to dump handlers via netlink_callback. Add any extack message after the dump_done_errno allowing error messages to be returned. This will be useful when strict checking is done on dump requests, returning why the dump fails EINVAL. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller

netlink: do not store start function in netlink_cb

2018-07-24T17:04:49Z

->start() is called once when dump is being initialized, there is no need to store it in netlink_cb. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

netlink: extack: avoid parenthesized string constant warning

2018-01-15T20:15:23Z

NL_SET_ERR_MSG() and NL_SET_ERR_MSG_ATTR() lead to the following warning in newer versions of gcc: warning: array initialized from parenthesized string constant Just remove the parentheses, they're not needed in this context since anyway since there can be no operator precendence issues or similar. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

netlink: remove unused NETLINK SKB flags

2017-11-14T12:51:14Z

These flags are unused, remove them to be less confusing. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller