From 70529a199574c15a40f46b14256633b02ba10ca2 Mon Sep 17 00:00:00 2001 From: Richard Guy Briggs Date: Fri, 3 Feb 2023 16:35:15 -0500 Subject: fanotify: define struct members to hold response decision context This patch adds a flag, FAN_INFO and an extensible buffer to provide additional information about response decisions. The buffer contains one or more headers defining the information type and the length of the following information. The patch defines one additional information type, FAN_RESPONSE_INFO_AUDIT_RULE, to audit a rule number. This will allow for the creation of other information types in the future if other users of the API identify different needs. The kernel can be tested if it supports a given info type by supplying the complete info extension but setting fd to FAN_NOFD. It will return the expected size but not issue an audit record. Suggested-by: Steve Grubb Link: https://lore.kernel.org/r/2745105.e9J7NaK4W3@x2 Suggested-by: Jan Kara Link: https://lore.kernel.org/r/20201001101219.GE17860@quack2.suse.cz Tested-by: Steve Grubb Acked-by: Steve Grubb Signed-off-by: Richard Guy Briggs Signed-off-by: Jan Kara Message-Id: <10177cfcae5480926b7176321a28d9da6835b667.1675373475.git.rgb@redhat.com> --- include/uapi/linux/fanotify.h | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index 436258214bb0..cd14c94e9a1e 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -188,15 +188,43 @@ struct fanotify_event_info_error { __u32 error_count; }; +/* + * User space may need to record additional information about its decision. + * The extra information type records what kind of information is included. + * The default is none. We also define an extra information buffer whose + * size is determined by the extra information type. + * + * If the information type is Audit Rule, then the information following + * is the rule number that triggered the user space decision that + * requires auditing. + */ + +#define FAN_RESPONSE_INFO_NONE 0 +#define FAN_RESPONSE_INFO_AUDIT_RULE 1 + struct fanotify_response { __s32 fd; __u32 response; }; +struct fanotify_response_info_header { + __u8 type; + __u8 pad; + __u16 len; +}; + +struct fanotify_response_info_audit_rule { + struct fanotify_response_info_header hdr; + __u32 rule_number; + __u32 subj_trust; + __u32 obj_trust; +}; + /* Legit userspace responses to a _PERM event */ #define FAN_ALLOW 0x01 #define FAN_DENY 0x02 -#define FAN_AUDIT 0x10 /* Bit mask to create audit record for result */ +#define FAN_AUDIT 0x10 /* Bitmask to create audit record for result */ +#define FAN_INFO 0x20 /* Bitmask to indicate additional information */ /* No fd set in event */ #define FAN_NOFD -1 -- cgit v1.2.3