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| author | Johannes Berg <johannes.berg@intel.com> | 2020-10-08 12:45:17 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-10-09 20:22:32 -0700 |
| commit | 44f3625bc61653ea3bde9960298faf2f5518fda5 (patch) | |
| tree | e36d5d8e5795a8992618cc2f756c5bc38d977434 /include/linux/netlink.h | |
| parent | d2681e93b0ab7afe01d07f8c96f14afaccdcea4c (diff) | |
| download | lwn-44f3625bc61653ea3bde9960298faf2f5518fda5.tar.gz lwn-44f3625bc61653ea3bde9960298faf2f5518fda5.zip | |
netlink: export policy in extended ACK
Add a new attribute NLMSGERR_ATTR_POLICY to the extended ACK
to advertise the policy, e.g. if an attribute was out of range,
you'll know the range that's permissible.
Add new NL_SET_ERR_MSG_ATTR_POL() and NL_SET_ERR_MSG_ATTR_POL()
macros to set this, since realistically it's only useful to do
this when the bad attribute (offset) is also returned.
Use it in lib/nlattr.c which practically does all the policy
validation.
v2:
- add and use netlink_policy_dump_attr_size_estimate()
v3:
- remove redundant break
v4:
- really remove redundant break ... sorry
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/netlink.h')
| -rw-r--r-- | include/linux/netlink.h | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/include/linux/netlink.h b/include/linux/netlink.h index e3e49f0e5c13..666cd0390699 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -68,12 +68,14 @@ netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg) * @_msg: message string to report - don't access directly, use * %NL_SET_ERR_MSG * @bad_attr: attribute with error + * @policy: policy for a bad attribute * @cookie: cookie data to return to userspace (for success) * @cookie_len: actual cookie data length */ struct netlink_ext_ack { const char *_msg; const struct nlattr *bad_attr; + const struct nla_policy *policy; u8 cookie[NETLINK_MAX_COOKIE_LEN]; u8 cookie_len; }; @@ -95,21 +97,29 @@ struct netlink_ext_ack { #define NL_SET_ERR_MSG_MOD(extack, msg) \ NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg) -#define NL_SET_BAD_ATTR(extack, attr) do { \ - if ((extack)) \ +#define NL_SET_BAD_ATTR_POLICY(extack, attr, pol) do { \ + if ((extack)) { \ (extack)->bad_attr = (attr); \ + (extack)->policy = (pol); \ + } \ } while (0) -#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do { \ - static const char __msg[] = msg; \ - struct netlink_ext_ack *__extack = (extack); \ - \ - if (__extack) { \ - __extack->_msg = __msg; \ - __extack->bad_attr = (attr); \ - } \ +#define NL_SET_BAD_ATTR(extack, attr) NL_SET_BAD_ATTR_POLICY(extack, attr, NULL) + +#define NL_SET_ERR_MSG_ATTR_POL(extack, attr, pol, msg) do { \ + static const char __msg[] = msg; \ + struct netlink_ext_ack *__extack = (extack); \ + \ + if (__extack) { \ + __extack->_msg = __msg; \ + __extack->bad_attr = (attr); \ + __extack->policy = (pol); \ + } \ } while (0) +#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) \ + NL_SET_ERR_MSG_ATTR_POL(extack, attr, NULL, msg) + static inline void nl_set_extack_cookie_u64(struct netlink_ext_ack *extack, u64 cookie) { |