SYSCTL(3)                 NetBSD Programmer's Manual                 SYSCTL(3)

NAME
     sysctl - get or set system information

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/param.h>
     #include <sys/sysctl.h>

     int
     sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
             size_t newlen);

DESCRIPTION
     The sysctl function retrieves system information and allows processes
     with appropriate privileges to set system information.  The information
     available from sysctl consists of integers, strings, and tables.  Infor-
     mation may be retrieved and set from the command interface using the
     sysctl(8) utility.

     Unless explicitly noted below, sysctl returns a consistent snapshot of
     the data requested.  Consistency is obtained by locking the destination
     buffer into memory so that the data may be copied out without blocking.
     Calls to sysctl are serialized to avoid deadlock.

     The state is described using a ``Management Information Base'' (MIB)
     style name, listed in name, which is a namelen length array of integers.

     The information is copied into the buffer specified by oldp.  The size of
     the buffer is given by the location specified by oldlenp before the call,
     and that location gives the amount of data copied after a successful
     call.  If the amount of data available is greater than the size of the
     buffer supplied, the call supplies as much data as fits in the buffer
     provided and returns with the error code ENOMEM.  If the old value is not
     desired, oldp and oldlenp should be set to NULL.

     The size of the available data can be determined by calling sysctl with a
     NULL parameter for oldp.  The size of the available data will be returned
     in the location pointed to by oldlenp.  For some operations, the amount
     of space may change often.  For these operations, the system attempts to
     round up so that the returned size is large enough for a call to return
     the data shortly thereafter.

     To set a new value, newp is set to point to a buffer of length newlen
     from which the requested value is to be taken.  If a new value is not to
     be set, newp should be set to NULL and newlen set to 0.

     The top level names are defined with a CTL_ prefix in <sys/sysctl.h>, and
     are as follows.  The next and subsequent levels down are found in the in-
     clude files listed here, and described in separate sections below.

           Name              Next level names          Description
           CTL_KERN          sys/sysctl.h              High kernel limits
           CTL_VM            uvm/uvm_param.h           Virtual memory
           CTL_VFS           sys/mount.h               Filesystem
           CTL_NET           sys/socket.h              Networking
           CTL_DEBUG         sys/sysctl.h              Debugging
           CTL_HW            sys/sysctl.h              Generic CPU, I/O
           CTL_MACHDEP       sys/sysctl.h              Machine dependent
           CTL_USER          sys/sysctl.h              User-level
           CTL_DDB           sys/sysctl.h              In-kernel debugger
           CTL_PROC          sys/sysctl.h              Per-process
           CTL_VENDOR        ?                         Vendor specific

     For example, the following retrieves the maximum number of processes al-
     lowed in the system:
           int mib[2], maxproc;
           size_t len;

           mib[0] = CTL_KERN;
           mib[1] = KERN_MAXPROC;
           len = sizeof(maxproc);
           sysctl(mib, 2, &maxproc, &len, NULL, 0);

     To retrieve the standard search path for the system utilities:
           int mib[2];
           size_t len;
           char *p;

           mib[0] = CTL_USER;
           mib[1] = USER_CS_PATH;
           sysctl(mib, 2, NULL, &len, NULL, 0);
           p = malloc(len);
           sysctl(mib, 2, p, &len, NULL, 0);

CTL_DEBUG
     The debugging variables vary from system to system.  A debugging variable
     may be added or deleted without need to recompile sysctl to know about
     it.  Each time it runs, sysctl gets the list of debugging variables from
     the kernel and displays their current values.  The system defines twenty
     (struct ctldebug) variables named debug0 through debug19.  They are de-
     clared as separate variables so that they can be individually initialized
     at the location of their associated variable.  The loader prevents multi-
     ple use of the same variable by issuing errors if a variable is initial-
     ized in more than one place.  For example, to export the variable
     dospecialcheck as a debugging variable, the following declaration would
     be used:
           int dospecialcheck = 1;
           struct ctldebug debug5 = { "dospecialcheck", &dospecialcheck };

CTL_VFS
     A distinguished second level name, VFS_GENERIC, is used to get general
     information about all filesystems.  One of its third level identifiers is
     VFS_MAXTYPENUM that gives the highest valid filesystem type number.  Its
     other third level identifier is VFS_CONF that returns configuration in-
     formation about the filesystem type given as a fourth level identifier.
     The remaining second level identifiers are the filesystem type number re-
     turned by a statfs(2) call or from VFS_CONF.  The third level identifiers
     available for each filesystem are given in the header file that defines
     the mount argument structure for that filesystem.

CTL_HW
     The string and integer information available for the CTL_HW level is de-
     tailed below.  The changeable column shows whether a process with appro-
     priate privilege may change the value.

           Second level name          Type                     Changeable
           HW_MACHINE                 string                   no
           HW_MODEL                   string                   no
           HW_NCPU                    integer                  no
           HW_BYTEORDER               integer                  no
           HW_PHYSMEM                 integer                  no
           HW_USERMEM                 integer                  no
           HW_PAGESIZE                integer                  no
           HW_MACHINE_ARCH            string                   no
           HW_ALIGNBYTES              integer                  no
           HW_DISKNAMES               string                   no
           HW_DISKSTATS               struct disk_sysctl       no

     HW_MACHINE
             The machine class.

     HW_MODEL
             The machine model

     HW_NCPU
             The number of cpus.

     HW_BYTEORDER
             The byteorder (4,321, or 1,234).

     HW_PHYSMEM
             The bytes of physical memory.

     HW_USERMEM
             The bytes of non-kernel memory.

     HW_PAGESIZE
             The software page size.

     HW_DISKNAMES
             The list of (space separated) disk device names on the system.

     HW_DISKSTATS
             Return statistical information on the disk devices on the system.
             An array of struct disk_sysctl structures is returned, whose size
             depends on the current number of such objects in the system.  The
             third level name is the size of the struct disk_sysctl.

     HW_MACHINE_ARCH
             The machine cpu class.

     HW_ALIGNBYTES
             Alignment constraint for all possible data types.  This shows the
             value ALIGNBYTES in /usr/include/machine/param.h, at the kernel
             compilation time.

CTL_KERN
     The string and integer information available for the CTL_KERN level is
     detailed below.  The changeable column shows whether a process with ap-
     propriate privilege may change the value.  The types of data currently
     available are process information, system vnodes, the open file entries,
     routing table entries, virtual memory statistics, load average history,
     and clock rate information.

           Second level name           Type                   Changeable
           KERN_ARGMAX                 integer                no
           KERN_AUTONICETIME           integer                yes
           KERN_AUTONICEVAL            integer                yes
           KERN_BOOTTIME               struct timeval         no
           KERN_CCPU                   integer                no
           KERN_CLOCKRATE              struct clockinfo       no
           KERN_CP_TIME                long[]                 no
           KERN_DEFCORENAME            string                 yes
           KERN_DOMAINNAME             string                 yes
           KERN_FILE                   struct file            no
           KERN_FSCALE                 integer                no
           KERN_FSYNC                  integer                no
           KERN_HOSTID                 integer                yes
           KERN_HOSTNAME               string                 yes
           KERN_IOV_MAX                integer                no
           KERN_JOB_CONTROL            integer                no
           KERN_LOGIN_NAME_MAX         integer                no
           KERN_LOGSIGEXIT             integer                yes
           KERN_MAPPED_FILES           integer                no
           KERN_MAXFILES               integer                yes
           KERN_MAXPARTITIONS          integer                no
           KERN_MAXPROC                integer                yes
           KERN_MAXPTYS                integer                yes
           KERN_MAXVNODES              integer                yes
           KERN_MBUF                   node                   not applicable
           KERN_MEMLOCK                integer                no
           KERN_MEMLOCK_RANGE          integer                no
           KERN_MEMORY_PROTECTION      integer                no
           KERN_MONOTONIC_CLOCK        integer                no
           KERN_MSGBUF                 char[]                 no
           KERN_MSGBUFSIZE             integer                no
           KERN_NGROUPS                integer                no
           KERN_NTPTIME                struct ntptimeval      no
           KERN_OSRELEASE              string                 no
           KERN_OSREV                  integer                no
           KERN_OSTYPE                 string                 no
           KERN_POSIX1                 integer                no
           KERN_PROC                   struct kinfo_proc      no
           KERN_PROC2                  struct kinfo_proc2     no
           KERN_PROC_ARGS              string                 no
           KERN_PROF                   node                   not applicable
           KERN_RAWPARTITION           integer                no
           KERN_ROOT_DEVICE            string                 no
           KERN_RTC_OFFSET             integer                no
           KERN_SAVED_IDS              integer                no
           KERN_SECURELVL              integer                raise only
           KERN_SYNCHRONIZED_IO        integer                no
           KERN_SYSVIPC_INFO           node                   not applicable
           KERN_SYSVMSG                integer                no
           KERN_SYSVSEM                integer                no
           KERN_SYSVSHM                integer                no
           KERN_TKSTAT                 node                   not applicable
           KERN_VERSION                string                 no
           KERN_VNODE                  struct vnode           no

     KERN_ARGMAX
             The maximum bytes of argument to execve(2).

     KERN_AUTONICETIME
             The number of seconds of cpu-time a non-root process may accumu-
             late before having its priority lowered from the default to the
             value of KERN_AUTONICEVAL.  If set to 0, automatic lowering of
             priority is not performed, and if set to -1 all non-root process-
             es are immediately lowered.

     KERN_AUTONICEVAL
             The priority assigned for automatically niced processes.

     KERN_BOOTTIME
             A struct timeval structure is returned.  This structure contains
             the time that the system was booted.

     KERN_CCPU
             The scheduler exponential decay value.

     KERN_CLOCKRATE
             A struct clockinfo structure is returned.  This structure con-
             tains the clock, statistics clock and profiling clock frequen-
             cies, the number of micro-seconds per hz tick, and the clock skew
             rate.

     KERN_CP_TIME
             Return an array if CPUSTATES longs is returned.  This array con-
             tains the number of clock ticks spent in different CPU states.

     KERN_DEFCORENAME
             Default template for the name of core dump files (see also
             PROC_PID_CORENAME in the per-process variables CTL_PROC, and
             core(5) for format of this template).  The default value is
             %n.core and can be changed with the kernel configuration option
             options DEFCORENAME (see options(4) ).

     KERN_DOMAINNAME
             Get or set the YP domain name.

     KERN_FILE
             Return the entire file table.  The returned data consists of a
             single struct filehead followed by an array of struct file, whose
             size depends on the current number of such objects in the system.

     KERN_FSCALE
             The kernel fixed-point scale factor.

     KERN_FSYNC
             Return 1 if the POSIX 1003.1b File Synchronization Option is
             available on this system, otherwise 0.

     KERN_HOSTID
             Get or set the host id.

     KERN_HOSTNAME
             Get or set the hostname.

     KERN_IOV_MAX
             Return the maximum number of iovec structures that a process has
             available for use with preadv(2), pwritev(2), readv(2),
             recvmsg(2), sendmsg(2) and writev(2).

     KERN_JOB_CONTROL
             Return 1 if job control is available on this system, otherwise 0.

     KERN_LOGIN_NAME_MAX
             The size of the storage required for a login name, in bytes, in-
             cluding the terminating NUL.

     KERN_LOGSIGEXIT
             If this flag is non-zero, the kernel will log(9) all process ex-
             its due to signals which create a core(5) file, and whether the
             coredump was created.

     KERN_MAPPED_FILES
             Returns 1 if the POSIX 1003.1b Memory Mapped Files Option is
             available on this system, otherwise 0.

     KERN_MAXFILES
             The maximum number of open files that may be open in the system.

     KERN_MAXPARTITIONS
             The maximum number of partitions allowed per disk.

     KERN_MAXPROC
             The maximum number of simultaneous processes the system will al-
             low.

     KERN_MAXPTYS
             The maximum number of pseudo terminals. This value can be both
             raised and lowered, though it cannot be set lower than number of
             currently used ptys.  See also pty(4).

     KERN_MAXVNODES
             The maximum number of vnodes available on the system. This can
             only be raised.

     KERN_MBUF
             Return information about the mbuf control variables.  the third
             level names for the mbuf variables are detailed below.  The
             changeable column shows whether a process with appropriate privi-
             lege may change the value.

                   Third level name       Type                 Changeable
                   MBUF_MSIZE             integer              yes
                   MBUF_MCLBYTES          integer              yes
                   MBUF_NMBCLUSTERS       integer              yes
                   MBUF_MBLOWAT           integer              yes
                   MBUF_MCLLOWAT          integer              yes

             The variables are as follows:

             MBUF_MSIZE
                     The mbuf base size.

             MBUF_MCLBYTES
                     The mbuf cluster size.

             MBUF_NMBCLUSTERS
                     The limit on the number of mbuf clusters.  The variable
                     can only be increased, and only increased on machines
                     with direct-mapped pool pages

             MBUF_MBLOWAT
                     The mbuf low water mark.

             MBUF_MCLLOWAT
                     The mbuf cluster low water mark.

     KERN_MEMLOCK
             Returns 1 if the POSIX 1003.1b Process Memory Locking Option is
             available on this system, otherwise 0.

     KERN_MEMLOCK_RANGE
             Returns 1 if the POSIX 1003.1b Range Memory Locking Option is
             available on this system, otherwise 0.

     KERN_MEMORY_PROTECTION
             Returns 1 if the POSIX 1003.1b Memory Protection Option is avail-
             able on this system, otherwise 0.

     KERN_MONOTONIC_CLOCK
             Returns the standard version the implementation of the POSIX
             1003.1b Monotonic Clock Option conforms to, otherwise 0.

     KERN_MSGBUF
             The kernel message buffer, rotated so that the head of the circu-
             lar kernel message buffer is returned at the start of the buffer
             specified by oldp.  The returned data may contain NUL bytes.

     KERN_MSGBUFSIZE
             The maximum number of characters that the kernel message buffer
             can hold.

     KERN_NGROUPS
             The maximum number of supplemental groups.

     KERN_NO_TRUNC
             Return 1 if file names longer than KERN_NAME_MAX are truncated.

     KERN_NTPTIME
             A struct ntptimeval structure is returned.  This structure con-
             tains data used by the ntpd(8) program.

     KERN_OSRELEASE
             The system release string.

     KERN_OSREV
             The system revision string.

     KERN_OSTYPE
             The system type string.

     KERN_PATH_MAX
             The maximum number of bytes in a pathname.

     KERN_POSIX1
             The version of ISO/IEC 9945 (POSIX 1003.1) with which the system
             attempts to comply.

     KERN_PROC
             Return the entire process table, or a subset of it.  An array of
             struct kinfo_proc structures is returned, whose size depends on
             the current number of such objects in the system.  The third and
             fourth level names are as follows:

                   Third level name          Fourth level is:
                   KERN_PROC_ALL             None
                   KERN_PROC_PID             A process ID
                   KERN_PROC_PGRP            A process group
                   KERN_PROC_SESSION         A session ID
                   KERN_PROC_TTY             A tty device
                   KERN_PROC_UID             A user ID
                   KERN_PROC_RUID            A real user ID
                   KERN_PROC_GID             A group ID
                   KERN_PROC_RGID            A real group ID

     KERN_PROC2
             As for KERN_PROC, but an array of struct kinfo_proc2 structures
             are returned.  The fifth level name is the size of the struct
             kinfo_proc2 and the sixth level name is the number of structures
             to return.

     KERN_PROC_ARGS
             Return the argv or environment strings (or the number thereof) of
             a process.  Multiple strings are returned separated by NUL char-
             acters.  The third level name is the process ID.  The fourth lev-
             el name is as follows:

                   KERN_PROC_ARGV            The argv strings
                   KERN_PROC_NARGV           The number of argv strings
                   KERN_PROC_ENV             The environ strings
                   KERN_PROC_NENV            The number of environ strings

     KERN_PROF
             Return profiling information about the kernel.  If the kernel is
             not compiled for profiling, attempts to retrieve any of the
             KERN_PROF values will fail with EOPNOTSUPP.  The third level
             names for the string and integer profiling information is de-
             tailed below.  The changeable column shows whether a process with
             appropriate privilege may change the value.

                   Third level name      Type                   Changeable
                   GPROF_STATE           integer                yes
                   GPROF_COUNT           u_short[]              yes
                   GPROF_FROMS           u_short[]              yes
                   GPROF_TOS             struct tostruct        yes
                   GPROF_GMONPARAM       struct gmonparam       no

             The variables are as follows:

             GPROF_STATE
                     Returns GMON_PROF_ON or GMON_PROF_OFF to show that pro-
                     filing is running or stopped.

             GPROF_COUNT
                     Array of statistical program counter counts.

             GPROF_FROMS
                     Array indexed by program counter of call-from points.

             GPROF_TOS
                     Array of struct tostruct describing destination of calls
                     and their counts.

             GPROF_GMONPARAM
                     Structure giving the sizes of the above arrays.

     KERN_RAWPARTITION
             The raw partition of a disk (a == 0).

     KERN_ROOT_DEVICE
             The name of the root device.

     KERN_RTC_OFFSET
             Return the offset of real time clock from UTC in minutes.

     KERN_SAVED_IDS
             Returns 1 if saved set-group and saved set-user ID is available.

     KERN_SECURELVL
             The system security level.  This level may be raised by processes
             with appropriate privilege.  It may only be lowered by process 1.

     KERN_SYNCHRONIZED_IO
             Returns 1 if the POSIX 1003.1b Synchronized I/O Option is avail-
             able on this system, otherwise 0.

     KERN_SYSVIPC_INFO
             Return System V style IPC configuration and run-time information.
             The third level name selects the System V style IPC facility.

                   Third level name            Type
                   KERN_SYSVIPC_MSG_INFO       struct msg_sysctl_info
                   KERN_SYSVIPC_SEM_INFO       struct sem_sysctl_info
                   KERN_SYSVIPC_SHM_INFO       struct shm_sysctl_info

             KERN_SYSVIPC_MSG_INFO
                     Return information on the System V style message facili-
                     ty.  The msg_sysctl_info structure is defined in
                     <sys/msg.h>.

             KERN_SYSVIPC_SEM_INFO
                     Return information on the System V style semaphore facil-
                     ity.  The sem_sysctl_info structure is defined in
                     <sys/sem.h>.

             KERN_SYSVIPC_SHM_INFO
                     Return information on the System V style shared memory
                     facility.  The shm_sysctl_info structure is defined in
                     <sys/shm.h>.

     KERN_SYSVMSG
             Returns 1 if System V style message queue functionality is avail-
             able on this system, otherwise 0.

     KERN_SYSVSEM
             Returns 1 if System V style semaphore functionality is available
             on this system, otherwise 0.

     KERN_SYSVSHM
             Returns 1 if System V style share memory functionality is avail-
             able on this system, otherwise 0.

     KERN_TKSTAT
             Return information about the number of characters sent and re-
             ceived on ttys.  The third level names for the tty statistic
             variables are detailed below.  The changeable column shows
             whether a process with appropriate privilege may change the val-
             ue.

                   Third level name        Type                 Changeable
                   KERN_TKSTAT_NIN         quad                 no
                   KERN_TKSTAT_NOUT        quad                 no
                   KERN_TKSTAT_CANCC       quad                 no
                   KERN_TKSTAT_RAWCC       quad                 no

             The variables are as follows:

             KERN_TKSTAT_NIN
                     The total number of input characters.

             KERN_TKSTAT_NOUT
                     The total number of output characters.

             KERN_TKSTAT_CANCC
                     The number of canonical input characters.

             KERN_TKSTAT_RAWCC
                     The number of raw input characters.

     KERN_VERSION
             The system version string.

     KERN_VNODE
             Return the entire vnode table.  Note, the vnode table is not nec-
             essarily a consistent snapshot of the system.  The returned data
             consists of an array whose size depends on the current number of
             such objects in the system.  Each element of the array contains
             the kernel address of a vnode struct vnode * followed by the vn-
             ode itself struct vnode.

CTL_MACHDEP
     The set of variables defined is architecture dependent.  Most architec-
     tures define at least the following variables.

           Second level name    Type          Changeable
           CPU_CONSDEV          dev_t         no

CTL_NET
     The string and integer information available for the CTL_NET level is de-
     tailed below.  The changeable column shows whether a process with appro-
     priate privilege may change the value.

           Second level name          Type                   Changeable
           PF_ROUTE                   routing messages       no
           PF_INET                    IPv4 values            yes
           PF_INET6                   IPv6 values            yes
           PF_KEY                     IPsec key management valuesyes

     PF_ROUTE
             Return the entire routing table or a subset of it.  The data is
             returned as a sequence of routing messages (see route(4) for the
             header file, format and meaning).  The length of each message is
             contained in the message header.

             The third level name is a protocol number, which is currently al-
             ways 0.  The fourth level name is an address family, which may be
             set to 0 to select all address families.  The fifth and sixth
             level names are as follows:

                   Fifth level name          Sixth level is:
                   NET_RT_FLAGS              rtflags
                   NET_RT_DUMP               None
                   NET_RT_IFLIST             None

     PF_INET
             Get or set various global information about the IPv4 (Internet
             Protocol version 4).  The third level name is the protocol.  The
             fourth level name is the variable name.  The currently defined
             protocols and names are:

                   Protocol name    Variable name      Type       Changeable
                   ip               forwarding         integer    yes
                   ip               redirect           integer    yes
                   ip               ttl                integer    yes
                   ip               forwsrcrt          integer    yes
                   ip               directed-broadcast integer    yes
                   ip               allowsrcrt         integer    yes
                   ip               subnetsarelocal    integer    yes
                   ip               mtudisc            integer    yes
                   ip               anonportmin        integer    yes
                   ip               anonportmax        integer    yes
                   ip               mtudisctimeout     integer    yes
                   ip               gifttl             integer    yes
                   ip               grettl             integer    yes
                   ip               lowportmin         integer    yes
                   ip               lowportmax         integer    yes
                   ip               maxfragpacket      integer    yes
                   icmp             maskrepl           integer    yes
                   icmp             errppslimit        integer    yes
                   icmp             rediraccept        integer    yes
                   icmp             redirtimeout       integer    yes
                   tcp              rfc1323            integer    yes
                   tcp              sendspace          integer    yes
                   tcp              recvspace          integer    yes
                   tcp              mssdflt            integer    yes
                   tcp              syn_cache_limit    integer    yes
                   tcp              syn_bucket_limit   integer    yes
                   tcp              syn_cache_interval integer    yes
                   tcp              init_win           integer    yes
                   tcp              mss_ifmtu          integer    yes
                   tcp              sack               integer    yes
                   tcp              win_scale          integer    yes
                   tcp              timestamps         integer    yes
                   tcp              compat_42          integer    yes
                   tcp              cwm                integer    yes
                   tcp              cwm_burstsize      integer    yes
                   tcp              ack_on_push        integer    yes
                   tcp              keepidle           integer    yes
                   tcp              keepintvl          integer    yes
                   tcp              keepcnt            integer    yes
                   tcp              slowhz             integer    no
                   tcp              newreno            integer    yes
                   tcp              log_refused        integer    yes
                   tcp              rstppslimit        integer    yes
                   udp              checksum           integer    yes
                   udp              sendspace          integer    yes
                   udp              recvspace          integer    yes

             The variables are as follows:

             ip.forwarding
                     Returns 1 when IP forwarding is enabled for the host,
                     meaning that the host is acting as a router.

             ip.redirect
                     Returns 1 when ICMP redirects may be sent by the host.
                     This option is ignored unless the host is routing IP
                     packets, and should normally be enabled on all systems.

             ip.ttl  The maximum time-to-live (hop count) value for an IP
                     packet sourced by the system.  This value applies to nor-
                     mal transport protocols, not to ICMP.

             ip.forwsrcrt
                     Returns 1 when forwarding of source-routed packets is en-
                     abled for the host.  This value may only be changed if
                     the kernel security level is less than 1.

             ip.directed-broadcast
                     Returns 1 if directed broadcast behavior is enabled for
                     the host.

             ip.allowsrcrt
                     Returns 1 if the host accepts source routed packets.

             ip.subnetsarelocal
                     Returns 1 if subnets are to be considered local address-
                     es.

             ip.mtudisc
                     Returns 1 if Path MTU Discovery is enabled.

             ip.anonportmin
                     The lowest port number to use for TCP and UDP ephemeral
                     port allocation.  This cannot be set to less than 1024 or
                     greater than 65535.

             ip.anonportmax
                     The highest port number to use for TCP and UDP ephemeral
                     port allocation.  This cannot be set to less than 1024 or
                     greater than 65535, and must be greater than
                     ip.anonportmin.

             ip.mtudisctimeout
                     Returns the number of seconds in which a route added by
                     the Path MTU Discovery engine will time out.  When the
                     route times out, the Path MTU Discovery engine will at-
                     tempt to probe a larger path MTU.

             ip.gifttl
                     The maximum time-to-live (hop count) value for an IPv4
                     packet generated by gif(4) tunnel interface.

             ip.grettl
                     The maximum time-to-live (hop count) value for an IPv4
                     packet generated by gre(4) tunnel interface.

             ip.lowportmin
                     The lowest port number to use for TCP and UDP reserved
                     port allocation.  This cannot be set to less than 0 or
                     greater than 1024, and must be smaller than
                     ip.lowportmax.

             ip.lowportmax
                     The highest port number to use for TCP and UDP reserved
                     port allocation.  This cannot be set to less than 0 or
                     greater than 1024, and must be greater than
                     ip.lowportmin.

             ip.maxfragpackets
                     The maximum number of fragmented packets the node will
                     accept.  0 means that the node will not accept any frag-
                     mented packets.  -1 means that the node will accept as
                     many fragmented packets as it receives.  The flag is pro-
                     vided basically for avoiding possible DoS attacks.

             icmp.maskrepl
                     Returns 1 if ICMP network mask requests are to be an-
                     swered.

             icmp.errppslimit
                     The variable specifies the maximum number of outgoing
                     ICMP error messages, per second.  ICMP error messages
                     that exceeded the value are subject to rate limitation
                     and will not go out from the node.  Negative value dis-
                     ables rate limitation.

             icmp.rediraccept
                     If set to non-zero, the host will accept ICMP redirect
                     packets.  Note that routers will never accept ICMP redi-
                     rect packets, and the variable is meaningful on IP hosts
                     only.

             icmp.redirtimeout
                     The variable specifies lifetime of routing entries gener-
                     ated by incoming ICMP redirect.  This defaults to 600
                     seconds.

             tcp.rfc1323
                     Returns 1 if RFC1323 extensions to TCP are enabled.

             tcp.sendspace
                     Returns the default TCP send buffer size.

             tcp.recvspace
                     Returns the default TCP receive buffer size.

             tcp.mssdflt
                     Returns the default maximum segment size both advertsized
                     to the peer and to use when the peer does not advertize a
                     maximum segment size to us during connection setup.  Do
                     not change this value unless you really know what you are
                     doing.

             tcp.syn_cache_limit
                     Returns the maximum number of entries allowed in the TCP
                     compressed state engine.

             tcp.syn_bucket_limit
                     Returns the maximum number of entries allowed per hash
                     bucket in the TCP compressed state engine.

             tcp.syn_cache_interval
                     Returns the TCP compressed state engine's timer interval.

             tcp.init_win
                     Returns a value indicating the TCP initial congestion
                     window.  If this value is 0, an auto-tuning algorithm de-
                     signed to use an initial window of approximately 4K bytes
                     is in use.  Otherwise, this value indicates a fixed num-
                     ber of packets.

             tcp.mss_ifmtu
                     Returns 1 if TCP calculates the outgoing maximum segment
                     size based on the MTU of the appropriate interface.  Oth-
                     erwise, it is calculated based on the greater of the MTU
                     of the interface, and the largest (non-loopback) inter-
                     face MTU on the system.

             tcp.sack
                     TCP Selective ACKnowledgement (RFC 2018) is not imple-
                     mented in NetBSD at this time.  Changing this value will
                     have no effect.

             tcp.win_scale
                     If rfc1323 is enabled, a value of 1 indicates RFC1323
                     window scale options, for increasing the TCP window size,
                     are enabled.

             tcp.timestamps
                     If rfc1323 is enabled, a value of 1 indicates RFC1323
                     time stamp options, used for measuring TCP round trip
                     times, are enabled.

             tcp.compat_42
                     Returns 1 if work-arounds for bugs in the 4.2BSD TCP im-
                     plementation are enabled.  Use of this option is not rec-
                     ommended, although it may be required in order to commu-
                     nicate with extremely old TCP implementations.

             tcp.cwm
                     Returns 1 if use of the Hughes/Touch/Heidemann Congestion
                     Window Monitoring algorithm is enabled.  This algorithm
                     prevents line-rate bursts of packets that could otherwise
                     occur when data begins flowing on an idle TCP connection.
                     These line-rate bursts can contribute to network and
                     router congestion.  This can be particularly useful on
                     World Wide Web servers which support HTTP/1.1, which has
                     lingering connections.

             tcp.cwm_burstsize
                     Returns the Congestion Window Monitoring allowed burst
                     size, in terms of packet count.

             tcp.ack_on_push
                     Returns 1 if TCP is to immediately transmit an ACK upon
                     reception of a packet with PUSH set.  This can avoid los-
                     ing a round trip time in some rare situations, but has
                     the caveat of potentially defeating TCP's delayed ACK al-
                     gorithm.  Use of this option is generally not recommend-
                     ed, but the variable exists in case your configuration
                     really needs it.

             tcp.keepidle
                     Time a connection must be idle before keepalives are sent
                     (if keepalives are enabled for the connection).  See also
                     tcp.slowhz.

             tcp.keepintvl
                     Time after a keepalive probe is sent until, in the ab-
                     sence of any response, another probe is sent.  See also
                     tcp.slowhz.

             tcp.keepcnt
                     Number of keepalive probes sent before declaring a con-
                     nection dead.  If set to zero, there is no limit;
                     keepalives will be sent until some kind of response is
                     received from the peer.

             tcp.slowhz
                     The units for tcp.keepidle and tcp.keepintvl; those vari-
                     ables are in ticks of a clock that ticks tcp.slowhz times
                     per second.  (That is, their values must be divided by
                     the tcp.slowhz value to get times in seconds.)

             tcp.newreno
                     Returns 1 if the use of J. Hoe's NewReno congestion con-
                     trol algorithm is enabled.  This algorithm improves the
                     start-up behavior of TCP connections.

             tcp.log_refused
                     Returns 1 if refused TCP connections to the host will be
                     logged.

             tcp.rstppslimit
                     The variable specifies the maximum number of outgoing TCP
                     RST packets, per second.  TCP RST packet that exceeded
                     the value are subject to rate limitation and will not go
                     out from the node.  Negative value disables rate limita-
                     tion.

             udp.checksum
                     Returns 1 when UDP checksums are being computed and
                     checked.  Disabling UDP checksums is strongly discour-
                     aged.

             udp.sendspace
                     Returns the default UDP send buffer size.

             udp.recvspace
                     Returns the default UDP receive buffer size.

             For variables net.*.ipsec, please refer to ipsec(4).

     PF_INET6
             Get or set various global information about the IPv6 (Internet
             Protocol version 6).  The third level name is the protocol.  The
             fourth level name is the variable name.  The currently defined
             protocols and names are:

                   Protocol name    Variable name      Type       Changeable
                   ip6              forwarding         integer    yes
                   ip6              redirect           integer    yes
                   ip6              hlim               integer    yes
                   ip6              maxfragpackets     integer    yes
                   ip6              accept_rtadv       integer    yes
                   ip6              keepfaith          integer    yes
                   ip6              log_interval       integer    yes
                   ip6              hdrnestlimit       integer    yes
                   ip6              dad_count          integer    yes
                   ip6              auto_flowlabel     integer    yes
                   ip6              defmcasthlim       integer    yes
                   ip6              gif_hlim           integer    yes
                   ip6              kame_version       string     no
                   ip6              use_deprecated     integer    yes
                   ip6              rr_prune           integer    yes
                   ip6              v6only             integer    yes
                   ip6              anonportmin        integer    yes
                   ip6              anonportmax        integer    yes
                   ip6              lowportmin         integer    yes
                   ip6              lowportmax         integer    yes
                   icmp6            rediraccept        integer    yes
                   icmp6            redirtimeout       integer    yes
                   icmp6            nd6_prune          integer    yes
                   icmp6            nd6_delay          integer    yes
                   icmp6            nd6_umaxtries      integer    yes
                   icmp6            nd6_mmaxtries      integer    yes
                   icmp6            nd6_useloopback    integer    yes
                   icmp6            nodeinfo           integer    yes
                   icmp6            errppslimit        integer    yes
                   icmp6            nd6_maxnudhint     integer    yes
                   icmp6            mtudisc_hiwat      integer    yes
                   icmp6            mtudisc_lowat      integer    yes
                   icmp6            nd6_debug          integer    yes
                   udp6             sendspace          integer    yes
                   udp6             recvspace          integer    yes

             The variables are as follows:

             ip6.forwarding
                     Returns 1 when IPv6 forwarding is enabled for the node,
                     meaning that the node is acting as a router.  Returns 0
                     when IPv6 forwarding is disabled for the node, meaning
                     that the node is acting as a host.  IPv6 specification
                     defines node behavior for ``router'' case and ``host''
                     case quite differently, and changing this variable during
                     operation may cause serious trouble.  It is recommended
                     to configure the variable at bootstrap time, and boot-
                     strap time only.

             ip6.redirect
                     Returns 1 when ICMPv6 redirects may be sent by the node.
                     This option is ignored unless the node is routing IP
                     packets, and should normally be enabled on all systems.

             ip6.hlim
                     The default hop limit value for an IPv6 unicast packet
                     sourced by the node.  This value applies to all the
                     transport protocols on top of IPv6.  There are APIs to
                     override the value, as documented in ip6(4).

             ip6.maxfragpackets
                     The maximum number of fragmented packets the node will
                     accept.  0 means that the node will not accept any frag-
                     mented packets.  -1 means that the node will accept as
                     many fragmented packets as it receives.  The flag is pro-
                     vided basically for avoiding possible DoS attacks.

             ip6.accept_rtadv
                     If set to non-zero, the node will accept ICMPv6 router
                     advertisement packets and autoconfigures address prefixes
                     and default routers.  The node must be a host (not a
                     router) for the option to be meaningful.

             ip6.keepfaith
                     If set to non-zero, it enables ``FAITH'' TCP relay
                     IPv6-to-IPv4 translator code in the kernel.  Refer
                     faith(4) and faithd(8) for detail.

             ip6.log_interval
                     The variable controls amount of logs generated by IPv6
                     packet forwarding engine, by seting interval between log
                     output (in seconds).

             ip6.hdrnestlimit
                     The number of IPv6 extension headers permitted on incom-
                     ing IPv6 packets.  If set to 0, the node will accept as
                     many extension headers as possible.

             ip6.dad_count
                     The variable cofigures number of IPv6 DAD (duplicated
                     address detection) probe packets.  The packets will be
                     generated when IPv6 interface addresses are configured.

             ip6.auto_flowlabel
                     On connected transport protocol packets, fill IPv6
                     flowlabel field to help intermediate routers to identify
                     packet flows.

             ip6.defmcasthlim
                     The default hop limit value for an IPv6 multicast packet
                     sourced by the node.  This value applies to all the
                     transport protocols on top of IPv6.  There are APIs to
                     override the value, as documented in ip6(4).

             ip6.gif_hlim
                     The maximum hop limit value for an IPv6 packet generated
                     by gif(4) tunnel interface.

             ip6.kame_version
                     The string identifies the version of KAME IPv6 stack im-
                     plemented in the kernel.

             ip6.use_deprecated
                     The variable controls use of deprecated address, speci-
                     fied in RFC2462 5.5.4.

             ip6.rr_prune
                     The variable specifies interval between IPv6 router
                     renumbering prefix babysitting, in seconds.

             ip6.v6only
                     The variable specifies initial value for IPV6_V6ONLY
                     socket option for AF_INET6 socket.  Please refer to
                     ip6(4) for detail.

             ip6.anonportmin
                     The lowest port number to use for TCP and UDP ephemeral
                     port allocation.  This cannot be set to less than 1024 or
                     greater than 65535.

             ip6.anonportmax
                     The highest port number to use for TCP and UDP ephemeral
                     port allocation.  This cannot be set to less than 1024 or
                     greater than 65535, and must be greater than
                     ip6.anonportmin.

             ip6.lowportmin
                     The lowest port number to use for TCP and UDP reserved
                     port allocation.  This cannot be set to less than 0 or
                     greater than 1024, and must be smaller than
                     ip6.lowportmax.

             ip6.lowportmax
                     The highest port number to use for TCP and UDP reserved
                     port allocation.  This cannot be set to less than 0 or
                     greater than 1024, and must be greater than
                     ip6.lowportmin.

             icmp6.rediraccept
                     If set to non-zero, the host will accept ICMPv6 redirect
                     packets.  Note that IPv6 routers will never accept ICMPv6
                     redirect packets, and the variable is meaningful on IPv6
                     hosts (non-router) only.

             icmp6.redirtimeout
                     The variable specifies lifetime of routing entries gener-
                     ated by incoming ICMPv6 redirect.

             icmp6.nd6_prune
                     The variable specifies interval between IPv6 neighbor
                     cache babysitting, in seconds.

             icmp6.nd6_delay
                     The variable specifies DELAY_FIRST_PROBE_TIME timing con-
                     stant in IPv6 neighbor discovery specification (RFC2461),
                     in seconds.

             icmp6.nd6_umaxtries
                     The variable specifies MAX_UNICAST_SOLICIT constant in
                     IPv6 neighbor discovery specification (RFC2461).

             icmp6.nd6_mmaxtries
                     The variable specifies MAX_MULTICAST_SOLICIT constant in
                     IPv6 neighbor discovery specification (RFC2461).

             icmp6.nd6_useloopback
                     If set to non-zero, kernel IPv6 stack will use loopback
                     interface for local traffic.

             icmp6.nodeinfo
                     The variable enables responses to ICMPv6 node information
                     queries.  If you set the variable to 0, reponses will not
                     be generated for ICMPv6 node information queries.  Since
                     node information queries can have a security impact, it
                     is possible to fine tune which responses should be an-
                     swered.  Two separate bits can be set.

                     1      Respond to ICMPv6 FQDN queries, e.g.  ping6 -w.

                     2      Respond to ICMPv6 node addresses queries, e.g.
                            ping6 -a.

             icmp6.errppslimit
                     The variable specifies the maximum number of outgoing
                     ICMPv6 error messages, per second.  ICMPv6 error messages
                     that exceeded the value are subject to rate limitation
                     and will not go out from the node.  Negative value dis-
                     ables rate limitation.

             icmp6.nd6_maxnudhint
                     IPv6 neighbor discovery permits upper layer protocols to
                     supply reachability hints, to avoid unnecessary neighbor
                     discovery exchanges.  The variable defines the number of
                     consecutive hints the neighbor discovery layer will take.
                     For example, by setting the variable to 3, neighbor dis-
                     covery layer will take 3 consecutive hints in maximum.
                     After receiving 3 hints, neighbor discovery layer will
                     perform normal neighbor discovery process.

             icmp6.mtudisc_hiwat

             icmp6.mtudisc_lowat
                     The variables define the maximum number of routing table
                     entries, created due to path MTU discovery (prevents
                     denial-of-service attacks with ICMPv6 too big messages).
                     When IPv6 path MTU discovery happens, we keep path MTU
                     information into the routing table.  If the number of
                     routing table entries exceed the value, the kernel will
                     not attempt to keep the path MTU information.
                     icmp6.mtudisc_hiwat is used when we have verified ICMPv6
                     too big messages.  icmp6.mtudisc_lowat is used when we
                     have unverified ICMPv6 too big messages.  Verification is
                     performed by using address/port pairs kept in connected
                     pcbs.  Negative value disables the upper limit.

             icmp6.nd6_debug
                     If set to non-zero, kernel IPv6 neighbor discovery code
                     will generate debugging messages.  The debug outputs are
                     useful to diagnose IPv6 interoperability issues.  The
                     flag must be set to 0 for normal operation.

             We reuse net.*.tcp for TCP over IPv6, and therefore we do not
             have variables net.*.tcp6.  Variables net.inet6.udp6 have identi-
             cal meaning to net.inet.udp.  Please refer to PF_INET section
             above.  For variables net.*.ipsec6, please refer to ipsec(4).

     PF_KEY  Get or set various global information about the IPsec key manage-
             ment.  The third level name is the variable name.  The currently
             defined variable and names are:

                   Variable name        Type       Changeable
                   debug                integer    yes
                   spi_try              integer    yes
                   spi_min_value        integer    yes
                   spi_max_value        integer    yes
                   random_int           integer    yes
                   larval_lifetime      integer    yes
                   blockacq_count       integer    yes
                   blockacq_lifetime    integer    yes
                   esp_keymin           integer    yes
                   esp_auth             integer    yes
                   ah_keymin            integer    yes
             The variables are as follows:

             debug   Turn on debugging message from within the kernel.  The
                     value is a bitmap, as defined in
                     /usr/include/netkey/key_debug.h.

             spi_try
                     The number of times the kernel will try to obtain an
                     unique SPI when it generates it from random number gener-
                     ator.

             spi_min_value
                     Minimum SPI value when generating it within the kernel.

             spi_max_value
                     Maximum SPI value when generating it within the kernel.

             random_int
                     Interval to stir pseudo-random number generator, in sec-
                     onds.  Pseudo-random number generator is used only as a
                     last resort when random number source (/dev/urandom) is
                     not available.  It should not really be used, and if it
                     were used, kernel will warn about it.

             larval_lifetime
                     Lifetime for LARVAL SAD entries, in seconds.

             blockacq_count
                     Number of ACQUIRE PF_KEY messages to be blocked after an
                     ACQUIRE message.  It avoids flood of ACQUIRE PF_KEY from
                     being sent from the kernel to the key management daemon.

             blockacq_lifetime
                     Lifetime of ACQUIRE PF_KEY message.

             esp_keymin
                     Minimum ESP key length, in bits.  The value is used when
                     the kernel creates proposal payload on ACQUIRE PF_KEY
                     message.

             esp_auth
                     Whether ESP authentication should be used or not.  Non-
                     zero value indicates that ESP authentication should be
                     used.  The value is used when the kernel creates proposal
                     payload on ACQUIRE PF_KEY message.

             ah_keymin
                     Minimum AH key length, in bits, The value is used when
                     the kernel creates proposal payload on ACQUIRE PF_KEY
                     message.

CTL_PROC
     The string and integer information available for the CTL_PROC is detailed
     below.  The changeable column shows whether a process with appropriate
     privilege may change the value.  These values are per-process, and as
     such may change from one process to another. When a process is created,
     the default values are inherited from its parent. When a set-user-ID or
     set-group-ID binary is executed, the value of PROC_PID_CORENAME is reset
     to the system default value.  The second level name is either the magic
     value PROC_CURPROC, which points to the current process, or the PID of
     the target process.

           Third level name            Type          Changeable
           PROC_PID_CORENAME           string        yes
           PROC_PID_LIMIT              node          not applicable

     PROC_PID_CORENAME
             The template used for the core dump file name (see core(5) for
             details). The base name must either be core or end with the suf-
             fix ``.core'' (the super-user may set arbitrary names). By de-
             fault it points to KERN_DEFCORENAME.

     PROC_PID_LIMIT
             Return resources limits, as defined for the getrlimit(2) and
             setrlimit(2) system calls.  The fourth level name is one of:

             PROC_PID_LIMIT_CPU        The maximum amount of cpu time (in sec-
                                       onds) to be used by each process.

             PROC_PID_LIMIT_FSIZE      The largest size (in bytes) file that
                                       may be created.

             PROC_PID_LIMIT_DATA       The maximum size (in bytes) of the data
                                       segment for a process; this defines how
                                       far a program may extend its break with
                                       the sbrk(2) system call.

             PROC_PID_LIMIT_STACK      The maximum size (in bytes) of the
                                       stack segment for a process; this de-
                                       fines how far a program's stack segment
                                       may be extended.  Stack extension is
                                       performed automatically by the system.

             PROC_PID_LIMIT_CORE       The largest size (in bytes) core file
                                       that may be created.

             PROC_PID_LIMIT_RSS        The maximum size (in bytes) to which a
                                       process's resident set size may grow.
                                       This imposes a limit on the amount of
                                       physical memory to be given to a pro-
                                       cess; if memory is tight, the system
                                       will prefer to take memory from pro-
                                       cesses that are exceeding their de-
                                       clared resident set size.

             PROC_PID_LIMIT_MEMLOCK    The maximum size (in bytes) which a
                                       process may lock into memory using the
                                       mlock(2) function.

             PROC_PID_LIMIT_NPROC      The maximum number of simultaneous pro-
                                       cesses for this user id.

             PROC_PID_LIMIT_NOFILE     The maximum number of open files for
                                       this process.

             The fifth level name is one of PROC_PID_LIMIT_TYPE_SOFT or
             PROC_PID_LIMIT_TYPE_HARD, to select respectively the soft or hard
             limit.  Both are of type integer.

CTL_USER
     The string and integer information available for the CTL_USER level is
     detailed below.  The changeable column shows whether a process with ap-
     propriate privilege may change the value.

           Second level name           Type          Changeable
           USER_BC_BASE_MAX            integer       no
           USER_BC_DIM_MAX             integer       no
           USER_BC_SCALE_MAX           integer       no
           USER_BC_STRING_MAX          integer       no
           USER_COLL_WEIGHTS_MAX       integer       no
           USER_CS_PATH                string        no
           USER_EXPR_NEST_MAX          integer       no
           USER_LINE_MAX               integer       no
           USER_POSIX2_CHAR_TERM       integer       no
           USER_POSIX2_C_BIND          integer       no
           USER_POSIX2_C_DEV           integer       no
           USER_POSIX2_FORT_DEV        integer       no
           USER_POSIX2_FORT_RUN        integer       no
           USER_POSIX2_LOCALEDEF       integer       no
           USER_POSIX2_SW_DEV          integer       no
           USER_POSIX2_UPE             integer       no
           USER_POSIX2_VERSION         integer       no
           USER_RE_DUP_MAX             integer       no
           USER_STREAM_MAX             integer       no
           USER_TZNAME_MAX             integer       no

     USER_BC_BASE_MAX
             The maximum ibase/obase values in the bc(1) utility.

     USER_BC_DIM_MAX
             The maximum array size in the bc(1) utility.

     USER_BC_SCALE_MAX
             The maximum scale value in the bc(1) utility.

     USER_BC_STRING_MAX
             The maximum string length in the bc(1) utility.

     USER_COLL_WEIGHTS_MAX
             The maximum number of weights that can be assigned to any entry
             of the LC_COLLATE order keyword in the locale definition file.

     USER_CS_PATH
             Return a value for the PATH environment variable that finds all
             the standard utilities.

     USER_EXPR_NEST_MAX
             The maximum number of expressions that can be nested within
             parenthesis by the expr(1) utility.

     USER_LINE_MAX
             The maximum length in bytes of a text-processing utility's input
             line.

     USER_POSIX2_CHAR_TERM
             Return 1 if the system supports at least one terminal type capa-
             ble of all operations described in POSIX 1003.2, otherwise 0.

     USER_POSIX2_C_BIND
             Return 1 if the system's C-language development facilities sup-
             port the C-Language Bindings Option, otherwise 0.

     USER_POSIX2_C_DEV
             Return 1 if the system supports the C-Language Development Utili-
             ties Option, otherwise 0.

     USER_POSIX2_FORT_DEV
             Return 1 if the system supports the FORTRAN Development Utilities
             Option, otherwise 0.

     USER_POSIX2_FORT_RUN
             Return 1 if the system supports the FORTRAN Runtime Utilities Op-
             tion, otherwise 0.

     USER_POSIX2_LOCALEDEF
             Return 1 if the system supports the creation of locales, other-
             wise 0.

     USER_POSIX2_SW_DEV
             Return 1 if the system supports the Software Development Utili-
             ties Option, otherwise 0.

     USER_POSIX2_UPE
             Return 1 if the system supports the User Portability Utilities
             Option, otherwise 0.

     USER_POSIX2_VERSION
             The version of POSIX 1003.2 with which the system attempts to
             comply.

     USER_RE_DUP_MAX
             The maximum number of repeated occurrences of a regular expres-
             sion permitted when using interval notation.

     USER_STREAM_MAX
             The minimum maximum number of streams that a process may have
             open at any one time.

     USER_TZNAME_MAX
             The minimum maximum number of types supported for the name of a
             timezone.

CTL_VM
     The string and integer information available for the CTL_VM level is de-
     tailed below.  The changeable column shows whether a process with appro-
     priate privilege may change the value.

           Second level name          Type                 Changeable
           VM_ANONMAX                 int                  yes
           VM_ANONMIN                 int                  yes
           VM_EXECMAX                 int                  yes
           VM_EXECMIN                 int                  yes
           VM_FILEMAX                 int                  yes
           VM_FILEMIN                 int                  yes
           VM_LOADAVG                 struct loadavg       no
           VM_MAXSLP                  int                  no
           VM_METER                   struct vmtotal       no
           VM_NKMEMPAGES              int                  no
           VM_USPACE                  int                  no
           VM_UVMEXP                  struct uvmexp        no
           VM_UVMEXP2                 struct uvmexp_sysctl no

     VM_ANONMAX
             The percentage of physical memory which will be reclaimed from
             other types of memory usage to store anonymous application data.

     VM_ANONMIN
             The percentage of physical memory which will be always be avail-
             able for anonymous application data.

     VM_EXECMAX
             The percentage of physical memory which will be reclaimed from
             other types of memory usage to store cached executable data.

     VM_EXECMIN
             The percentage of physical memory which will be always be avail-
             able for cached executable data.

     VM_FILEMAX
             The percentage of physical memory which will be reclaimed from
             other types of memory usage to store cached file data.

     VM_FILEMIN
             The percentage of physical memory which will be always be avail-
             able for cached file data.

     VM_LOADAVG
             Return the load average history.  The returned data consists of a
             struct loadavg.

     VM_MAXSLP
             The value of the maxslp kernel global variable.

     VM_METER
             Return system wide virtual memory statistics.  The returned data
             consists of a struct vmtotal.

     VM_USPACE
             The number of bytes allocated for each kernel stack.

     VM_UVMEXP
             Return system wide virtual memory statistics.  The returned data
             consists of a struct uvmexp.

     VM_UVMEXP2
             Return system wide virtual memory statistics.  The returned data
             consists of a struct uvmexp_sysctl.

CTL_DDB
     The integer information available for the CTL_DDB level is detailed be-
     low.  The changeable column shows whether a process with appropriate
     privilege may change the value.

           Second level name    Type          Changeable
           DBCTL_RADIX          integer       yes
           DBCTL_MAXOFF         integer       yes
           DBCTL_LINES          integer       yes
           DBCTL_TABSTOPS       integer       yes
           DBCTL_ONPANIC        integer       yes
           DBCTL_FROMCONSOLE    integer       yes

     DBCTL_RADIX
             The input and output radix.

     DBCTL_MAXOFF
             The maximum symbol offset.

     DBCTL_LINES
             Number of display lines.

     DBCTL_TABSTOPS
             Tab width.

     DBCTL_ONPANIC
             If non-zero, DDB will be entered when the kernel panics.

     DBCTL_FROMCONSOLE
             If not zero, DDB may be entered by sending a break on a serial
             console or by a special key sequence on a graphics console.

     These MIB nodes are also available as variables from within the DDB.  See
     ddb(4) for more details.

CTL_VENDOR
     The "vendor" toplevel name is reserved to be used by vendors who wish to
     have their own private MIB tree. Intended use is to store values under
     ``vendor.<yourname>.*''.

RETURN VALUES
     If the call to sysctl is successful, the number of bytes copied out is
     returned.  Otherwise -1 is returned and errno is set appropriately.

FILES
     <sys/sysctl.h>         definitions for top level identifiers, second lev-
                            el kernel and hardware identifiers, and user level
                            identifiers
     <sys/socket.h>         definitions for second level network identifiers
     <sys/gmon.h>           definitions for third level profiling identifiers
     <uvm/uvm_param.h>      definitions for second level virtual memory iden-
                            tifiers
     <netinet/in.h>         definitions for third level IPv4/v6 identifiers
                            and fourth level IPv4/v6 identifiers
     <netinet/icmp_var.h>   definitions for fourth level ICMP identifiers
     <netinet/icmp6.h>      definitions for fourth level ICMPv6 identifiers
     <netinet/tcp_var.h>    definitions for fourth level TCP identifiers
     <netinet/udp_var.h>    definitions for fourth level UDP identifiers
     <netinet6/udp6_var.h>  definitions for fourth level IPv6 UDP identifiers
     <netinet6/ipsec.h>     definitions for fourth level IPsec identifiers
     <netkey/key_var.h>     definitions for third level PF_KEY identifiers

ERRORS
     The following errors may be reported:

     [EFAULT]      The buffer name, oldp, newp, or length pointer oldlenp con-
                   tains an invalid address.

     [EINVAL]      The name array is less than two or greater than CTL_MAX-
                   NAME.

     [EINVAL]      A non-null newp is given and its specified length in newlen
                   is too large or too small.

     [ENOMEM]      The length pointed to by oldlenp is too short to hold the
                   requested value.

     [ENOTDIR]     The name array specifies an intermediate rather than termi-
                   nal name.

     [EOPNOTSUPP]  The name array specifies a value that is unknown.

     [EPERM]       An attempt is made to set a read-only value.

     [EPERM]       A process without appropriate privilege attempts to set a
                   value.

     [EPERM]       An attempt to change a value protected by the current ker-
                   nel security level is made.

SEE ALSO
     ipsec(4), sysctl(8)

HISTORY
     The sysctl function first appeared in 4.4BSD.

NetBSD 1.6                       June 24, 1999                              24

You can also request any man page by name and (optionally) by section:

Command: 
Section: 
Architecture: 
Collection: 
 

Use the DEFAULT collection to view manual pages for third-party software.


©1994 Man-cgi 1.15, Panagiotis Christias <christia@softlab.ntua.gr>
©1996-2014 Modified for NetBSD by Kimmo Suominen