RCTL_ADD_RULE(2)          FreeBSD System Calls Manual         RCTL_ADD_RULE(2)

NAME
     rctl_add_rule, rctl_get_limits, rctl_get_racct, rctl_get_rules,
     rctl_remove_rule - manipulate and query the resource limits database

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/rctl.h>

     int
     rctl_add_rule(const char *inbufp, size_t inbuflen, char *outbufp,
         size_t outbuflen);

     int
     rctl_get_limits(const char *inbufp, size_t inbuflen, char *outbufp,
         size_t outbuflen);

     int
     rctl_get_racct(const char *inbufp, size_t inbuflen, char *outbufp,
         size_t outbuflen);

     int
     rctl_get_rules(const char *inbufp, size_t inbuflen, char *outbufp,
         size_t outbuflen);

     int
     rctl_remove_rule(const char *inbufp, size_t inbuflen, char *outbufp,
         size_t outbuflen);

DESCRIPTION
     These system calls are used to manipulate and query the resource limits
     database.  For all functions, inbuflen refers to the length of the buffer
     pointed to by inbufp and outbuflen refers to the length of the buffer
     pointed to by outbufp.

     The rctl_add_rule() function adds the rule pointed to by inbufp to the
     resource limits database.  The outbufp and outbuflen arguments are
     unused.  Rule format is as described in rctl(8), with exceptions noted in
     the RULES AND FILTERS section.

     The rctl_get_limits() function returns in outbufp a comma-separated list
     of rules that apply to the process that matches the filter specified in
     inbufp.  This includes rules with a subject of the process itself as well
     as rules with a different subject (such as user or loginclass) that apply
     to the process.

     The rctl_get_racct() function returns resource usage information for a
     given subject.  The subject is specified by passing a filter in inbufp.
     Filter syntax is as described in rctl(8), with exceptions noted in the
     RULES AND FILTERS section.  A comma-separated list of resources and the
     amount used of each by the specified subject is returned in outbufp.  The
     resource and amount is formatted as "resource=amount".

     The rctl_get_rules() function returns in outbufp a comma-separated list
     of rules from the resource limits database that match the filter passed
     in inbufp.  Filter syntax is as described in rctl(8), with exceptions
     noted in the RULES AND FILTERS section.  A filter of :: may be passed to
     return all rules.

     The rctl_remove_rule() function removes all rules matching the filter
     passed in inbufp from the resource limits database.  Filter syntax is as
     described in rctl(8), with exceptions noted in the RULES AND FILTERS
     section.  outbufp and outbuflen are unused.

RULES AND FILTERS
     This section explains how the rule and filter format described in rctl(8)
     differs from the format passed to the system calls themselves.  The rctl
     tool provides several conveniences that the system calls do not.  When
     using the system call:

           -   The subject must be fully specified.  For example, abbreviating
               `user' to `u' is not acceptable.

           -   User and group IDs must be numeric.  For example, `root' must
               be expressed as `0'.

           -   Units are not permitted on resource amounts.  For example, a
               quantity of 1024 bytes must be expressed as `1024' and not
               `1k'.

RETURN VALUES
     Upon successful completion, the value 0 is returned; otherwise the
     value -1 is returned and the global variable errno is set to indicate the
     error.

ERRORS
     The rctl system calls may fail if:

     [ENOSYS]           RACCT/RCTL support is not present in the kernel or the
                        kern.racct.enable sysctl is 0.

     [EINVAL]           The rule or filter passed in inbufp is invalid.

     [EPERM]            User has insufficient privileges to carry out the
                        requested operation.

     [E2BIG]            inbufp or outbufp are too large.

     [ESRCH]            No process matched the provided rule or filter.

     [ENAMETOOLONG]     The loginclass or jail name specified is too long.

     [ERANGE]           The rule amount is outside of the allowable range or
                        outbufp is too small.

     [EOPNOTSUPP]       The requested operation is not supported for the given
                        rule or filter.

     [EFAULT]           inbufp or outbufp refer to invalid addresses.

SEE ALSO
     rctl(8)

HISTORY
     The rctl family of system calls appeared in FreeBSD 9.0.

AUTHORS
     The rctl system calls were developed by Edward Tomasz Napierala
     <trasz@FreeBSD.org> under sponsorship from the FreeBSD Foundation.  This
     manual page was written by Eric Badger <badger@FreeBSD.org>.

FreeBSD 13.1-RELEASE-p6       September 14, 2016       FreeBSD 13.1-RELEASE-p6