ich777/linux_media
1
0
Fork 0
mirror of https://github.com/tbsdtv/linux_media.git synced 2025-07-23 20:51:03 +02:00
Code Issues Packages Projects Releases Wiki Activity

netlink: export policy in extended ACK

Browse Source 
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>
This commit is contained in:
Johannes Berg
2020-10-08 12:45:17 +02:00
committed by Jakub Kicinski
parent d2681e93b0
commit 44f3625bc6
6 changed files with 111 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
include/linux/netlink.h
View File

@@ -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); \
} 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); \
(extack)->policy = (pol); \
} \
} while (0)
#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)
{