[PATCH 0/2] audit string fields interface + consumer

Following are two patches, the first of which provides an interface for specifying audit rules with string fields. The second patch adds a new string field AUDIT_WATCH. These patches are an update of the previous audit interface patches I have posted to this list. These patches are functionally similar to the previous posts; however, I believe you will find the organization of the code to be quite different and much improved. I have updated the interface based on the feedback I received. I also resolved the issue of differentiating between inode-based and path-based (or watch-based) filtering by creating a new field AUDIT_WATCH and adding it to the switch in audit_filter_rules(). Following is a summary of the interface. A new struct audit_rule_data and corresponding netlink message types have been added. Additionally, the SELinux nlmsg_audit_perms[] table has been updated with the new netlink message types. The new struct allows userspace to supply one or more string fields packed in a variable length buffer. The kernel expects the buffer to be neither null-delimited nor null-terminated. The length of string data for a given field is provided as its value element in the array. The kernel provides the buflen element for convenience on rule listing, to allow userspace to allocate memory for the buffer without walking the array to tabulate lengths. Buflen is ignored coming from userspace. Instead, the kernel ensures that the total of the lengths specified in the value elements do not exceed the length of the message payload minus sizeof(struct audit_rule_data). Several routines have been added to auditfilter.c to translate between the kernel's rule representation and the two userspace rule representations using structs audit_rule and audit_rule_data.