1.\" $NetBSD: sysctl.3,v 1.62 2000/07/10 09:34:39 itojun Exp $ 2.\" 3.\" Copyright (c) 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)sysctl.3 8.4 (Berkeley) 5/9/95 35.\" 36.Dd June 24, 1999 37.Dt SYSCTL 3 38.Os 39.Sh NAME 40.Nm sysctl 41.Nd get or set system information 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include <sys/param.h> 46.Fd #include <sys/sysctl.h> 47.Ft int 48.Fn sysctl "int *name" "u_int namelen" "void *oldp" "size_t *oldlenp" "void *newp" "size_t newlen" 49.Sh DESCRIPTION 50The 51.Nm 52function retrieves system information and allows processes with 53appropriate privileges to set system information. 54The information available from 55.Nm 56consists of integers, strings, and tables. 57Information may be retrieved and set from the command interface 58using the 59.Xr sysctl 8 60utility. 61.Pp 62Unless explicitly noted below, 63.Nm 64returns a consistent snapshot of the data requested. 65Consistency is obtained by locking the destination 66buffer into memory so that the data may be copied out without blocking. 67Calls to 68.Nm 69are serialized to avoid deadlock. 70.Pp 71The state is described using a ``Management Information Base'' (MIB) 72style name, listed in 73.Fa name , 74which is a 75.Fa namelen 76length array of integers. 77.Pp 78The information is copied into the buffer specified by 79.Fa oldp . 80The size of the buffer is given by the location specified by 81.Fa oldlenp 82before the call, 83and that location gives the amount of data copied after a successful call. 84If the amount of data available is greater 85than the size of the buffer supplied, 86the call supplies as much data as fits in the buffer provided 87and returns with the error code ENOMEM. 88If the old value is not desired, 89.Fa oldp 90and 91.Fa oldlenp 92should be set to NULL. 93.Pp 94The size of the available data can be determined by calling 95.Nm 96with a NULL parameter for 97.Fa oldp . 98The size of the available data will be returned in the location pointed to by 99.Fa oldlenp . 100For some operations, the amount of space may change often. 101For these operations, 102the system attempts to round up so that the returned size is 103large enough for a call to return the data shortly thereafter. 104.Pp 105To set a new value, 106.Fa newp 107is set to point to a buffer of length 108.Fa newlen 109from which the requested value is to be taken. 110If a new value is not to be set, 111.Fa newp 112should be set to NULL and 113.Fa newlen 114set to 0. 115.Pp 116The top level names are defined with a CTL_ prefix in 117.Pa <sys/sysctl.h> , 118and are as follows. 119The next and subsequent levels down are found in the include files 120listed here, and described in separate sections below. 121.Pp 122.Bl -column CTLXMACHDEPXXX "Next level namesXXXXXX" -offset indent 123.It Sy Pa Name Next level names Description 124.It CTL\_DEBUG sys/sysctl.h Debugging 125.It CTL\_VFS sys/mount.h Filesystem 126.It CTL\_HW sys/sysctl.h Generic CPU, I/O 127.It CTL\_KERN sys/sysctl.h High kernel limits 128.It CTL\_MACHDEP sys/sysctl.h Machine dependent 129.It CTL\_NET sys/socket.h Networking 130.It CTL\_PROC sys/sysctl.h Per-process 131.It CTL\_USER sys/sysctl.h User-level 132.It CTL\_VM uvm/uvm_param.h Virtual memory 133.El 134.Pp 135For example, the following retrieves the maximum number of processes allowed 136in the system: 137.Bd -literal -offset indent -compact 138int mib[2], maxproc; 139size_t len; 140.sp 141mib[0] = CTL_KERN; 142mib[1] = KERN_MAXPROC; 143len = sizeof(maxproc); 144sysctl(mib, 2, &maxproc, &len, NULL, 0); 145.Ed 146.sp 147To retrieve the standard search path for the system utilities: 148.Bd -literal -offset indent -compact 149int mib[2]; 150size_t len; 151char *p; 152.sp 153mib[0] = CTL_USER; 154mib[1] = USER_CS_PATH; 155sysctl(mib, 2, NULL, &len, NULL, 0); 156p = malloc(len); 157sysctl(mib, 2, p, &len, NULL, 0); 158.Ed 159.Sh CTL_DEBUG 160The debugging variables vary from system to system. 161A debugging variable may be added or deleted without need to recompile 162.Nm 163to know about it. 164Each time it runs, 165.Nm 166gets the list of debugging variables from the kernel and 167displays their current values. 168The system defines twenty 169.Ns ( Va struct ctldebug ) 170variables named 171.Dv debug0 172through 173.Dv debug19 . 174They are declared as separate variables so that they can be 175individually initialized at the location of their associated variable. 176The loader prevents multiple use of the same variable by issuing errors 177if a variable is initialized in more than one place. 178For example, to export the variable 179.Dv dospecialcheck 180as a debugging variable, the following declaration would be used: 181.Bd -literal -offset indent -compact 182int dospecialcheck = 1; 183struct ctldebug debug5 = { "dospecialcheck", &dospecialcheck }; 184.Ed 185.Sh CTL_VFS 186A distinguished second level name, VFS_GENERIC, 187is used to get general information about all filesystems. 188One of its third level identifiers is VFS_MAXTYPENUM 189that gives the highest valid filesystem type number. 190Its other third level identifier is VFS_CONF that 191returns configuration information about the filesystem 192type given as a fourth level identifier. 193The remaining second level identifiers are the 194filesystem type number returned by a 195.Xr statfs 2 196call or from VFS_CONF. 197The third level identifiers available for each filesystem 198are given in the header file that defines the mount 199argument structure for that filesystem. 200.Sh CTL_HW 201The string and integer information available for the CTL_HW level 202is detailed below. 203The changeable column shows whether a process with appropriate 204privilege may change the value. 205.Bl -column "Second level nameXXXXXX" integerXXX -offset indent 206.It Sy Pa Second level name Type Changeable 207.It HW\_MACHINE string no 208.It HW\_MODEL string no 209.It HW\_NCPU integer no 210.It HW\_BYTEORDER integer no 211.It HW\_PHYSMEM integer no 212.It HW\_USERMEM integer no 213.It HW\_PAGESIZE integer no 214.\".It HW\_DISKNAMES struct no 215.\".It HW\_DISKSTATS struct no 216.It HW\_MACHINE\_ARCH string no 217.It HW\_ALIGNBYTES integer no 218.El 219.Pp 220.Bl -tag -width "123456" 221.It Li HW_MACHINE 222The machine class. 223.It Li HW_MODEL 224The machine model 225.It Li HW_NCPU 226The number of cpus. 227.ne 1i 228.It Li HW_BYTEORDER 229The byteorder (4,321, or 1,234). 230.It Li HW_PHYSMEM 231The bytes of physical memory. 232.It Li HW_USERMEM 233The bytes of non-kernel memory. 234.It Li HW_PAGESIZE 235The software page size. 236.\".It Fa HW_DISKNAMES 237.\".It Fa HW_DISKSTATS 238.It Li HW_MACHINE_ARCH 239The machine cpu class. 240.It Li HW_ALIGNBYTES 241Alignment constraint for all possible data types. 242This shows the value 243.Dv ALIGNBYTES 244in 245.Pa /usr/include/machine/param.h , 246at the kernel compilation time. 247.El 248.Sh CTL_KERN 249The string and integer information available for the CTL_KERN level 250is detailed below. 251The changeable column shows whether a process with appropriate 252privilege may change the value. 253The types of data currently available are process information, 254system vnodes, the open file entries, routing table entries, 255virtual memory statistics, load average history, and clock rate 256information. 257.Bl -column "KERNXCHOWNXRESTRICTEDXXX" "struct clockrateXXX" -offset indent 258.It Sy Pa Second level name Type Changeable 259.It KERN\_ARGMAX integer no 260.It KERN\_AUTONICETIME integer yes 261.It KERN\_AUTONICEVAL integer yes 262.It KERN\_BOOTTIME struct timeval no 263.It KERN\_CCPU integer no 264.It KERN\_CLOCKRATE struct clockinfo no 265.It KERN\_CP\_TIME long[\|] no 266.It KERN\_DEFCORENAME string yes 267.It KERN\_DOMAINNAME string yes 268.It KERN\_FILE struct file no 269.It KERN\_FSCALE integer no 270.It KERN\_FSYNC integer no 271.It KERN\_HOSTID integer yes 272.It KERN\_HOSTNAME string yes 273.It KERN\_IOV\_MAX integer no 274.It KERN\_JOB\_CONTROL integer no 275.It KERN\_LOGIN\_NAME\_MAX integer no 276.It KERN\_LOGSIGEXIT integer yes 277.It KERN\_MAPPED\_FILES integer no 278.It KERN\_MAXFILES integer yes 279.It KERN\_MAXPARTITIONS integer no 280.It KERN\_MAXPROC integer yes 281.It KERN\_MAXVNODES integer yes 282.It KERN\_MBUF node not applicable 283.It KERN\_MEMLOCK integer no 284.It KERN\_MEMLOCK\_RANGE integer no 285.It KERN\_MEMORY\_PROTECTION integer no 286.It KERN\_MSGBUF char[\|] no 287.It KERN\_MSGBUFSIZE integer no 288.It KERN\_NGROUPS integer no 289.It KERN\_NTPTIME struct ntptimeval no 290.It KERN\_OSRELEASE string no 291.It KERN\_OSREV integer no 292.It KERN\_OSTYPE string no 293.It KERN\_POSIX1 integer no 294.It KERN\_PROC struct kinfo_proc no 295.It KERN\_PROC2 struct kinfo_proc2 no 296.It KERN\_PROC\_ARGS string no 297.It KERN\_PROF node not applicable 298.It KERN\_RAWPARTITION integer no 299.It KERN\_ROOT\_DEVICE string no 300.It KERN\_RTC\_OFFSET integer yes 301.It KERN\_SAVED\_IDS integer no 302.It KERN\_SECURELVL integer raise only 303.It KERN\_SYNCHRONIZED\_IO integer no 304.It KERN\_SYSVIPC\_INFO node not applicable 305.It KERN\_SYSVMSG integer no 306.It KERN\_SYSVSEM integer no 307.It KERN\_SYSVSHM integer no 308.It KERN\_VERSION string no 309.It KERN\_VNODE struct vnode no 310.El 311.ne 1i 312.Pp 313.Bl -tag -width "123456" 314.It Li KERN_ARGMAX 315The maximum bytes of argument to 316.Xr execve 2 . 317.It Li KERN_AUTONICETIME 318The number of seconds of cpu-time a non-root process may accumulate before 319having its priority lowered from the default to the value of KERN_AUTONICEVAL. 320If set to 0, automatic lowering of priority is not performed, and if set to -1 321all non-root processes are immediately lowered. 322.It Li KERN_AUTONICEVAL 323The priority assigned for automatically niced processes. 324.It Li KERN_BOOTTIME 325A 326.Va struct timeval 327structure is returned. 328This structure contains the time that the system was booted. 329.It Li KERN_CCPU 330The scheduler exponential decay value. 331.It Li KERN_CLOCKRATE 332A 333.Va struct clockinfo 334structure is returned. 335This structure contains the clock, statistics clock and profiling clock 336frequencies, the number of micro-seconds per hz tick, and the clock 337skew rate. 338.It Li KERN_CP_TIME 339Return an array if CPUSTATES longs is returned. This array contains the 340number of clock ticks spent in different CPU states. 341.It Li KERN_DEFCORENAME 342Default template for the name of core dump files (see also PROC_PID_CORENAME 343in the per-process variables CTL_PROC, and 344.Xr core 5 345for format of this template). The default value is 346.Nm %n.core 347and can be changed with the kernel configuration option 348.Cd options DEFCORENAME 349(see 350.Xr options 4 351). 352.It Li KERN_DOMAINNAME 353Get or set the YP domain name. 354.It Li KERN_FILE 355Return the entire file table. 356The returned data consists of a single 357.Va struct filehead 358followed by an array of 359.Va struct file , 360whose size depends on the current number of such objects in the system. 361.It Li KERN_FSCALE 362The kernel fixed-point scale factor. 363.It Li KERN_FSYNC 364Return 1 if the POSIX 1003.1b File Synchronization Option is available 365on this system, 366otherwise 0. 367.It Li KERN_HOSTID 368Get or set the host id. 369.It Li KERN_HOSTNAME 370Get or set the hostname. 371.It Li KERN_IOV_MAX 372Return the maximum number of 373.Va iovec 374structures that a process has available for use with 375.Xr preadv 2 , 376.Xr pwritev 2 , 377.Xr readv 2 , 378.Xr recvmsg 2 , 379.Xr sendmsg 2 380and 381.Xr writev 2 . 382.It Li KERN_JOB_CONTROL 383Return 1 if job control is available on this system, otherwise 0. 384.It Li KERN_LOGIN_NAME_MAX 385The size of the storage required for a login name, in bytes, 386including the terminating NUL. 387.It Li KERN_LOGSIGEXIT 388If this flag is non-zero, the kernel will 389.Xr log 9 390all process exits due to signals which create a 391.Xr core 5 392file, and whether the coredump was created. 393.It Li KERN_MAPPED_FILES 394Returns 1 if the POSIX 1003.1b Memory Mapped Files Option is available 395on this system, 396otherwise 0. 397.It Li KERN_MAXFILES 398The maximum number of open files that may be open in the system. 399.It Li KERN_MAXPARTITIONS 400The maximum number of partitions allowed per disk. 401.It Li KERN_MAXPROC 402The maximum number of simultaneous processes the system will allow. 403.It Li KERN_MAXVNODES 404The maximum number of vnodes available on the system. 405.It Li KERN_MBUF 406Return information about the mbuf control variables. 407the third level names for the mbuf variables are detailed below. 408The changeable column shows whether a process with appropriate 409privilege may change the value. 410.Bl -column "MBUFXNMBCLUSTERSXXX" "struct integerXXX" -offset indent 411.It MBUF\_MSIZE integer yes 412.It MBUF\_MCLBYTES integer yes 413.It MBUF\_NMBCLUSTERS integer yes 414.It MBUF\_MBLOWAT integer yes 415.It MBUF\_MCLLOWAT integer yes 416.El 417.Pp 418The variables are as follows: 419.Bl -tag -width "123456" 420.It Li MBUF_MSIZE 421The mbuf base size. 422.It Li MBUF_MCLBYTES 423The mbuf cluster size. 424.It Li MBUF_NMBCLUSTERS 425The limit on the number of mbuf clusters. 426The variable can only be increased, and only increased on machines with 427direct-mapped pool pages 428.It Li MBUF_MBLOWAT 429The mbuf low water mark. 430.It Li MBUF_MCLLOWAT 431The mbuf cluster low water mark. 432.El 433.It Li KERN_MEMLOCK 434Returns 1 if the POSIX 1003.1b Process Memory Locking Option is available 435on this system, 436otherwise 0. 437.It Li KERN_MEMLOCK_RANGE 438Returns 1 if the POSIX 1003.1b Range Memory Locking Option is available 439on this system, 440otherwise 0. 441.It Li KERN_MEMORY_PROTECTION 442Returns 1 if the POSIX 1003.1b Memory Protection Option is available 443on this system, 444otherwise 0. 445.It Li KERN_MSGBUF 446The kernel message buffer, rotated so that the head of the circular kernel 447message buffer is returned at the start of the buffer specified by 448.Fa oldp . 449The returned data may contain NUL bytes. 450.It Li KERN_MSGBUFSIZE 451The maximum number of characters that the kernel message buffer can hold. 452.It Li KERN_NGROUPS 453The maximum number of supplemental groups. 454.It Li KERN_NO_TRUNC 455Return 1 if file names longer than KERN_NAME_MAX are truncated. 456.It Li KERN_NTPTIME 457A 458.Va struct ntptimeval 459structure is returned. 460This structure contains data used by the 461.Xr ntpd 8 462program. 463.It Li KERN_OSRELEASE 464The system release string. 465.It Li KERN_OSREV 466The system revision string. 467.It Li KERN_OSTYPE 468The system type string. 469.It Li KERN_PATH_MAX 470The maximum number of bytes in a pathname. 471.It Li KERN_POSIX1 472The version of ISO/IEC 9945 (POSIX 1003.1) with which the system 473attempts to comply. 474.It Li KERN_PROC 475Return the entire process table, or a subset of it. 476An array of 477.Va struct kinfo_proc 478structures is returned, 479whose size depends on the current number of such objects in the system. 480The third and fourth level names are as follows: 481.Bl -column "Third level nameXXXXXX" "Fourth level is:XXXXXX" -offset indent 482.It Pa Third level name Fourth level is: 483.It KERN\_PROC\_ALL None 484.It KERN\_PROC\_PID A process ID 485.It KERN\_PROC\_PGRP A process group 486.It KERN\_PROC\_SESSION A session ID 487.It KERN\_PROC\_TTY A tty device 488.It KERN\_PROC\_UID A user ID 489.It KERN\_PROC\_RUID A real user ID 490.It KERN\_PROC\_GID A group ID 491.It KERN\_PROC\_RGID A real group ID 492.El 493.It Li KERN_PROC2 494As for KERN_PROC, but an array of 495.Va struct kinfo_proc2 496structures are returned. The fifth level name is the size of the 497.Va struct kinfo_proc2 498and the sixth level name is the number of structures to return. 499.It Li KERN_PROC_ARGS 500Return the argv or environment strings (or the number thereof) 501of a process. Multiple strings are returned separated by NUL 502characters. The third level name is the process ID. The fourth 503level name is as follows: 504.Bl -column "Third level nameXXXXXX" -offset indent 505.It KERN\_PROC\_ARGV The argv strings 506.It KERN\_PROC\_NARGV The number of argv strings 507.It KERN\_PROC\_ENV The environ strings 508.It KERN\_PROC\_NENV The number of environ strings 509.El 510.It Li KERN_PROF 511Return profiling information about the kernel. 512If the kernel is not compiled for profiling, 513attempts to retrieve any of the KERN_PROF values will 514fail with EOPNOTSUPP. 515The third level names for the string and integer profiling information 516is detailed below. 517The changeable column shows whether a process with appropriate 518privilege may change the value. 519.Bl -column "GPROFXGMONPARAMXXX" "struct gmonparamXXX" -offset indent 520.It Sy Pa Third level name Type Changeable 521.It GPROF\_STATE integer yes 522.It GPROF\_COUNT u_short[\|] yes 523.It GPROF\_FROMS u_short[\|] yes 524.It GPROF\_TOS struct tostruct yes 525.It GPROF\_GMONPARAM struct gmonparam no 526.El 527.Pp 528The variables are as follows: 529.Bl -tag -width "123456" 530.It Li GPROF_STATE 531Returns GMON_PROF_ON or GMON_PROF_OFF to show that profiling 532is running or stopped. 533.It Li GPROF_COUNT 534Array of statistical program counter counts. 535.It Li GPROF_FROMS 536Array indexed by program counter of call-from points. 537.It Li GPROF_TOS 538Array of 539.Va struct tostruct 540describing destination of calls and their counts. 541.It Li GPROF_GMONPARAM 542Structure giving the sizes of the above arrays. 543.El 544.It Li KERN_RAWPARTITION 545The raw partition of a disk (a == 0). 546.It Li KERN_ROOT_DEVICE 547The name of the root device. 548.It Li KERN_RTC_OFFSET 549Return the offset of real time clock from UTC in minutes. 550.It Li KERN_SAVED_IDS 551Returns 1 if saved set-group and saved set-user ID is available. 552.It Li KERN_SECURELVL 553The system security level. 554This level may be raised by processes with appropriate privilege. 555It may only be lowered by process 1. 556.It Li KERN_SYNCHRONIZED_IO 557Returns 1 if the POSIX 1003.1b Synchronized I/O Option is available 558on this system, 559otherwise 0. 560.It Li KERN_SYSVIPC_INFO 561Return System V style IPC configuration and run-time information. 562The third level name selects the System V style IPC facility. 563.Bl -column "KERN_SYSVIPC_MSG_INFOXXX" "struct shm_sysctl_infoXXX" -offset indent 564.It Sy Pa Third level name Type 565.It KERN\_SYSVIPC\_MSG\_INFO struct msg_sysctl_info 566.It KERN\_SYSVIPC\_SEM\_INFO struct sem_sysctl_info 567.It KERN\_SYSVIPC\_SHM\_INFO struct shm_sysctl_info 568.El 569.Pp 570.Bl -tag -width "123456" 571.It Li KERN_SYSVIPC_MSG_INFO 572Return information on the System V style message facility. The 573.Sy msg_sysctl_info 574structure is defined in 575.Aq Pa sys/msg.h . 576.It Li KERN_SYSVIPC_SEM_INFO 577Return information on the System V style semaphore facility. The 578.Sy sem_sysctl_info 579structure is defined in 580.Aq Pa sys/sem.h . 581.It Li KERN_SYSVIPC_SHM_INFO 582Return information on the System V style shared memory facility. The 583.Sy shm_sysctl_info 584structure is defined in 585.Aq Pa sys/shm.h . 586.El 587.It Li KERN_SYSVMSG 588Returns 1 if System V style message queue functionality is available 589on this system, 590otherwise 0. 591.It Li KERN_SYSVSEM 592Returns 1 if System V style semaphore functionality is available 593on this system, 594otherwise 0. 595.It Li KERN_SYSVSHM 596Returns 1 if System V style share memory functionality is available 597on this system, 598otherwise 0. 599.It Li KERN_VERSION 600The system version string. 601.It Li KERN_VNODE 602Return the entire vnode table. 603Note, the vnode table is not necessarily a consistent snapshot of 604the system. 605The returned data consists of an array whose size depends on the 606current number of such objects in the system. 607Each element of the array contains the kernel address of a vnode 608.Va struct vnode * 609followed by the vnode itself 610.Va struct vnode . 611.El 612.Sh CTL_MACHDEP 613The set of variables defined is architecture dependent. 614Most architectures define at least the following variables. 615.Bl -column "CONSOLE_DEVICEXXX" "integerXXX" -offset indent 616.It Sy Pa Second level name Type Changeable 617.It Li CPU_CONSDEV dev_t no 618.El 619.Sh CTL_NET 620The string and integer information available for the CTL_NET level 621is detailed below. 622The changeable column shows whether a process with appropriate 623privilege may change the value. 624.Bl -column "Second level nameXXXXXX" "routing messagesXXX" -offset indent 625.It Sy Pa Second level name Type Changeable 626.It PF\_ROUTE routing messages no 627.It PF\_INET IPv4 values yes 628.It PF\_INET6 IPv6 values yes 629.El 630.Pp 631.Bl -tag -width "123456" 632.It Li PF_ROUTE 633Return the entire routing table or a subset of it. 634The data is returned as a sequence of routing messages (see 635.Xr route 4 636for the header file, format and meaning). 637The length of each message is contained in the message header. 638.Pp 639The third level name is a protocol number, which is currently always 0. 640The fourth level name is an address family, which may be set to 0 to 641select all address families. 642The fifth and sixth level names are as follows: 643.Bl -column "Fifth level nameXXXXXX" "Sixth level is:XXX" -offset indent 644.It Pa Fifth level name Sixth level is: 645.It NET\_RT\_FLAGS rtflags 646.It NET\_RT\_DUMP None 647.It NET\_RT\_IFLIST None 648.El 649.It Li PF_INET 650Get or set various global information about the IPv4 651.Pq Internet Protocol version 4 . 652The third level name is the protocol. 653The fourth level name is the variable name. 654The currently defined protocols and names are: 655.Bl -column "Protocol name" "Variable nameXX" "integer" "yes" -offset indent 656.It Pa Protocol name Variable name Type Changeable 657.It ip forwarding integer yes 658.It ip redirect integer yes 659.It ip ttl integer yes 660.It ip forwsrcrt integer yes 661.It ip directed-broadcast integer yes 662.It ip allowsrcrt integer yes 663.It ip subnetsarelocal integer yes 664.It ip mtudisc integer yes 665.It ip anonportmin integer yes 666.It ip anonportmax integer yes 667.It ip mtudisctimeout integer yes 668.It ip gifttl integer yes 669.It icmp errratelimit integer yes 670.It icmp maskrepl integer yes 671.It icmp errppslimit integer yes 672.It tcp rfc1323 integer yes 673.It tcp sendspace integer yes 674.It tcp recvspace integer yes 675.It tcp mssdflt integer yes 676.It tcp syn_cache_limit integer yes 677.It tcp syn_bucket_limit integer yes 678.It tcp syn_cache_interval integer yes 679.It tcp init_win integer yes 680.It tcp mss_ifmtu integer yes 681.It tcp sack integer yes 682.It tcp win_scale integer yes 683.It tcp timestamps integer yes 684.It tcp compat_42 integer yes 685.It tcp cwm integer yes 686.It tcp cwm_burstsize integer yes 687.It tcp ack_on_push integer yes 688.It tcp keepidle integer yes 689.It tcp keepintvl integer yes 690.It tcp keepcnt integer yes 691.It tcp slowhz integer no 692.It tcp newreno integer yes 693.It tcp log_refused integer yes 694.It tcp rstratelimit integer yes 695.It udp checksum integer yes 696.It udp sendspace integer yes 697.It udp recvspace integer yes 698.El 699.Pp 700The variables are as follows: 701.Bl -tag -width "123456" 702.It Li ip.forwarding 703Returns 1 when IP forwarding is enabled for the host, 704meaning that the host is acting as a router. 705.It Li ip.redirect 706Returns 1 when ICMP redirects may be sent by the host. 707This option is ignored unless the host is routing IP packets, 708and should normally be enabled on all systems. 709.It Li ip.ttl 710The maximum time-to-live (hop count) value for an IP packet sourced by 711the system. 712This value applies to normal transport protocols, not to ICMP. 713.It Li ip.forwsrcrt 714Returns 1 when forwarding of source-routed packets is enabled for 715the host. This value may only be changed if the kernel security 716level is less than 1. 717.It Li ip.directed-broadcast 718Returns 1 if directed broadcast behavior is enabled for the host. 719.It Li ip.allowsrcrt 720Returns 1 if the host accepts source routed packets. 721.It Li ip.subnetsarelocal 722Returns 1 if subnets are to be considered local addresses. 723.It Li ip.mtudisc 724Returns 1 if Path MTU Discovery is enabled. 725.It Li ip.anonportmin 726The lowest port number to use for TCP and UDP ephemeral port allocation. 727This cannot be set to less that 1024 or greater than 65535. 728.It Li ip.anonportmax 729The highest port number to use for TCP and UDP ephemeral port allocation. 730This cannot be set to less that 1024 or greater than 65535, and must 731be greater than 732.Li ip.anonportmin . 733.It Li ip.mtudisctimeout 734Returns the number of seconds in which a route added by the Path MTU 735Discovery engine will time out. When the route times out, the Path 736MTU Discovery engine will attempt to probe a larger path MTU. 737.It Li ip.gifttl 738The maximum time-to-live (hop count) value for an IPv4 packet generated by 739.Xr gif 4 740tunnel interface. 741.It Li icmp.errratelimit 742This variable specifies the minimum interval between ICMP error messages, 743in microseconds. 744.It Li icmp.maskrepl 745Returns 1 if ICMP network mask requests are to be answered. 746.It Li icmp.errppslimit 747The variable specifies the maximum number of outgoing ICMP error messages, 748per second. 749ICMP error messages that exceeded the value are subject to rate limitation 750and will not go out from the node. 751.It Li tcp.rfc1323 752Returns 1 if RFC1323 extensions to TCP are enabled. 753.It Li tcp.sendspace 754Returns the default TCP send buffer size. 755.It Li tcp.recvspace 756Returns the default TCP receive buffer size. 757.It Li tcp.mssdflt 758Returns the default maximum segment size both advertsized to the peer 759and to use when the peer does not advertize a maximum segment size to 760us during connection setup. Do not change this value unless you really 761know what you are doing. 762.It Li tcp.syn_cache_limit 763Returns the maximum number of entries allowed in the TCP compressed state 764engine. 765.It Li tcp.syn_bucket_limit 766Returns the maximum number of entries allowed per hash bucket in the TCP 767compressed state engine. 768.It Li tcp.syn_cache_interval 769Returns the TCP compressed state engine's timer interval. 770.It Li tcp.init_win 771Returns a value indicating the TCP initial congestion window. If this 772value is 0, an auto-tuning algorithm designed to use an initial window 773of approximately 4K bytes is in use. Otherwise, this value indicates 774a fixed number of packets. 775.It Li tcp.mss_ifmtu 776Returns 1 if TCP calculates the outgoing maximum segment size based on 777the MTU of the appropriate interface. Otherwise, it is calculated based on 778the greater of the MTU of the interface, and the largest (non-loopback) 779interface MTU on the system. 780.It Li tcp.sack 781Returns a value which determines the level of Selective Acknowledgement 782supported by TCP. If 2, we will transmit and receive SACK options. 783If 1, we will transmit SACK options, but ignore any SACK options received. 784If 0, SACK is disabled. 785.It Li tcp.win_scale 786If rfc1323 is enabled, a value of 1 indicates RFC1323 window scale options, 787for increasing the TCP window size, are enabled. 788.It Li tcp.timestamps 789If rfc1323 is enabled, a value of 1 indicates RFC1323 time stamp options, 790used for measuring TCP round trip times, are enabled. 791.It Li tcp.compat_42 792Returns 1 if work-arounds for bugs in the 4.2BSD TCP implementation are 793enabled. Use of this option is not recommended, although it may be 794required in order to communicate with extremely old TCP implementations. 795.It Li tcp.cwm 796Returns 1 if use of the Hughes/Touch/Heidemann Congestion Window Monitoring 797algorithm is enabled. This algorithm prevents line-rate bursts of packets 798that could otherwise occur when data begins flowing on an idle TCP 799connection. These line-rate bursts can contribute to network and router 800congestion. This can be particularly useful on World Wide Web servers 801which support HTTP/1.1, which has lingering connections. 802.It Li tcp.cwm_burstsize 803Returns the Congestion Window Monitoring allowed burst size, in terms 804of packet count. 805.It Li tcp.ack_on_push 806Returns 1 if TCP is to immediately transmit an ACK upon reception of 807a packet with PUSH set. This can avoid losing a round trip time in some 808rare situations, but has the caveat of potentially defeating TCP's delayed 809ACK algorithm. Use of this option is generally not recommended, but 810the variable exists in case your configuration really needs it. 811.It Li tcp.keepidle 812Time a connection must be idle before keepalives are sent (if keepalives 813are enabled for the connection). See also tcp.slowhz. 814.It Li tcp.keepintvl 815Time after a keepalive probe is sent until, in the absence of any response, 816another probe is sent. See also tcp.slowhz. 817.It Li tcp.keepcnt 818Number of keepalive probes sent before declaring a connection dead. If 819set to zero, there is no limit; keepalives will be sent until some kind of 820response is received from the peer. 821.It Li tcp.slowhz 822The units for tcp.keepidle and tcp.keepintvl; those variables are in ticks 823of a clock that ticks tcp.slowhz times per second. (That is, their values 824must be divided by the tcp.slowhz value to get times in seconds.) 825.It Li tcp.newreno 826Returns 1 if the use of J. Hoe's NewReno congestion control algorithm is 827enabled. This algorithm improves the start-up behavior of TCP connections. 828.It Li tcp.log_refused 829Returns 1 if refused TCP connections to the host will be logged. 830.It Li tcp.rstratelimit 831This variable specifies minimum interval, in microseconds, between RSTs 832sent in response to an incoming TCP packet with no corresponding listen 833or connected socket. 834.It Li udp.checksum 835Returns 1 when UDP checksums are being computed and checked. 836Disabling UDP checksums is strongly discouraged. 837.It Li udp.sendspace 838Returns the default UDP send buffer size. 839.It Li udp.recvspace 840Returns the default UDP receive buffer size. 841.El 842.Pp 843For variables net.*.ipsec, please refer to 844.Xr ipsec 4 . 845.It Li PF_INET6 846Get or set various global information about the IPv6 847.Pq Internet Protocol version 6 . 848The third level name is the protocol. 849The fourth level name is the variable name. 850The currently defined protocols and names are: 851.Bl -column "Protocol name" "Variable nameXX" "integer" "yes" -offset indent 852.It Pa Protocol name Variable name Type Changeable 853.It ip6 forwarding integer yes 854.It ip6 redirect integer yes 855.It ip6 hlim integer yes 856.It ip6 maxfragpackets integer yes 857.It ip6 accept_rtadv integer yes 858.It ip6 keepfaith integer yes 859.It ip6 log_interval integer yes 860.It ip6 hdrnestlimit integer yes 861.It ip6 dad_count integer yes 862.It ip6 auto_flowlabel integer yes 863.It ip6 defmcasthlim integer yes 864.It ip6 gif_hlim integer yes 865.It ip6 kame_version string no 866.It ip6 use_deprecated integer yes 867.It ip6 rr_prune integer yes 868.It ip6 bindv6only integer yes 869.It icmp6 rediraccept integer yes 870.It icmp6 redirtimeout integer yes 871.It icmp6 errratelimit integer yes 872.It icmp6 nd6_prune integer yes 873.It icmp6 nd6_delay integer yes 874.It icmp6 nd6_umaxtries integer yes 875.It icmp6 nd6_mmaxtries integer yes 876.It icmp6 nd6_useloopback integer yes 877.It icmp6 nodeinfo integer yes 878.It icmp6 errppslimit integer yes 879.It icmp6 nd6_maxnudhint integer yes 880.It udp6 sendspace integer yes 881.It udp6 recvspace integer yes 882.El 883.Pp 884The variables are as follows: 885.Bl -tag -width "123456" 886.It Li ip6.forwarding 887Returns 1 when IPv6 forwarding is enabled for the node, 888meaning that the node is acting as a router. 889Returns 0 when IPv6 forwarding is disabled for the node, 890meaning that the node is acting as a host. 891IPv6 specification defines node behavior for 892.Dq router 893case and 894.Dq host 895case quite differently, and changing this variable during operation 896may cause serious trouble. 897It is recommended to configure the variable at bootstrap time, 898and bootstrap time only. 899.It Li ip6.redirect 900Returns 1 when ICMPv6 redirects may be sent by the node. 901This option is ignored unless the node is routing IP packets, 902and should normally be enabled on all systems. 903.It Li ip6.hlim 904The default hop limit value for an IPv6 unicast packet sourced by the node. 905This value applies to all the transport protocols on top of IPv6. 906There are APIs to override the value, as documented in 907.Xr ip6 4 . 908.It Li ip6.maxfragpackets 909The maximum number of fragmented packets the node will accept. 9100 means that the node will not accept any fragmented packets. 911-1 means that the node will accept as many fragmented packets as it receives. 912The flag is provided basically for avoiding possible DoS attacks. 913.It Li ip6.accept_rtadv 914If set to non-zero, the node will accept ICMPv6 router advertisement packets 915and autoconfigures address prefixes and default routers. 916The node must be a host 917.Pq not a router 918for the option to be meaningful. 919.It Li ip6.keepfaith 920If set to non-zero, it enables 921.Dq FAITH 922TCP relay IPv6-to-IPv4 translator code in the kernel. 923Refer 924.Xr faith 4 925and 926.Xr faithd 8 927for detail. 928.It Li ip6.log_interval 929The variable controls amount of logs generated by IPv6 packet 930forwarding engine, by seting interval between log output 931.Pq in seconds . 932.It Li ip6.hdrnestlimit 933The number of IPv6 extension headers permitted on incoming IPv6 packets. 934If set to 0, the node will accept as many extension headers as possible. 935.It Li ip6.dad_count 936The variable cofigures number of IPv6 DAD 937.Pq duplicated address detection 938probe packets. 939The packets will be generated when IPv6 interface addresses are configured. 940.It Li ip6.auto_flowlabel 941On connected transport protocol packets, 942fill IPv6 flowlabel field to help intermediate routers to identify packet flows. 943.It Li ip6.defmcasthlim 944The default hop limit value for an IPv6 multicast packet sourced by the node. 945This value applies to all the transport protocols on top of IPv6. 946There are APIs to override the value, as documented in 947.Xr ip6 4 . 948.It Li ip6.gif_hlim 949The maximum hop limit value for an IPv6 packet generated by 950.Xr gif 4 951tunnel interface. 952.It Li ip6.kame_version 953The string identifies the version of KAME IPv6 stack implemented in the kernel. 954.It Li ip6.use_deprecated 955The variable controls use of deprecated address, specified in RFC2462 5.5.4. 956.It Li ip6.rr_prune 957The variable specifies interval between IPv6 router renumbering prefix 958babysitting, in seconds. 959.It Li ip6.bindv6only 960The variable specifies initial value for 961.Dv IPV6_BINDV6ONLY 962socket option for 963.Dv AF_INET6 964socket. 965Please refer to 966.Xr ip6 4 967for detail. 968.It Li icmp6.rediraccept 969If set to non-zero, the host will accept ICMPv6 redirect packets. 970Note that IPv6 routers will never accept ICMPv6 redirect packets, 971and the variable is meaningful on IPv6 hosts 972.Pq non-router 973only. 974.It Li icmp6.redirtimeout 975The variable specifies lifetime of routing entries generated by incoming 976ICMPv6 redirect. 977.It Li icmp6.errratelimit 978The variable specifies minimum interval between ICMPv6 error messages, 979in microseconds. 980.It Li icmp6.nd6_prune 981The variable specifies interval between IPv6 neighbor cache babysitting, 982in seconds. 983.It Li icmp6.nd6_delay 984The variable specifies 985.Dv DELAY_FIRST_PROBE_TIME 986timing constant in IPv6 neighbor discovery specification 987.Pq RFC2461 , 988in seconds. 989.It Li icmp6.nd6_umaxtries 990The variable specifies 991.Dv MAX_UNICAST_SOLICIT 992constant in IPv6 neighbor discovery specification 993.Pq RFC2461 . 994.It Li icmp6.nd6_mmaxtries 995The variable specifies 996.Dv MAX_MULTICAST_SOLICIT 997constant in IPv6 neighbor discovery specification 998.Pq RFC2461 . 999.It Li icmp6.nd6_useloopback 1000If set to non-zero, kernel IPv6 stack will use loopback interface for 1001local traffic. 1002.It Li icmp6.nodeinfo 1003The variable enables, or disables, kernel support for 1004ICMPv6 node information query/reply. 1005.It Li icmp6.errppslimit 1006The variable specifies the maximum number of outgoing ICMPv6 error messages, 1007per second. 1008ICMPv6 error messages that exceeded the value are subject to rate limitation 1009and will not go out from the node. 1010.It Li icmp6.nd6_maxnudhint 1011IPv6 neighbor discovery permits upper layer protocols to supply reachability 1012hints, to avoid unnecessary neighbor discovery exchanges. 1013The variable defines the number of consecutive hints the neighbor discovery 1014layer will take. 1015For example, by setting the variable to 3, neighbor discovery layer 1016will take 3 consecutive hints in maximum. 1017After receiving 3 hints, neighbor discovery layer will perform 1018normal neighbor discovery process. 1019.El 1020.Pp 1021We reuse net.*.tcp for 1022.Tn TCP 1023over 1024.Tn IPv6 , 1025and therefore we do not have variables net.*.tcp6. 1026Variables net.inet6.udp6 have identical meaning to net.inet.udp. 1027Please refer to 1028.Li PF_INET 1029section above. 1030For variables net.*.ipsec6, please refer to 1031.Xr ipsec 4 . 1032.El 1033.Sh CTL_PROC 1034The string and integer information available for the CTL_PROC 1035is detailed below. 1036The changeable column shows whether a process with appropriate 1037privilege may change the value. 1038These values are per-process, and as such may change from one process 1039to another. When a process is created, the default values are inherited from 1040its parent. When a set-user-ID or set-group-ID binary is executed, the 1041value of PROC_PID_CORENAME is reset to the system default value. 1042The second level name is either the magic value PROC_CURPROC, which 1043points to the current process, or the PID of the target process. 1044.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" "yes" -offset indent 1045.It Sy Pa Third level name Type Changeable 1046.It PROC\_PID\_CORENAME string yes 1047.It PROC\_PID\_LIMIT node not applicable 1048.El 1049.Bl -tag -width "123456" 1050.Pp 1051.It Li PROC_PID_CORENAME 1052The template used for the core dump file name (see 1053.Xr core 5 1054for details). The base name must either be 1055.Nm core 1056or end with the suffix ``.core'' (the super-user may set arbitrary names). By 1057default it points to KERN_DEFCORENAME. 1058.It Li PROC_PID_LIMIT 1059Return resources limits, as defined for the 1060.Xr getrlimit 2 1061and 1062.Xr setrlimit 2 1063system calls. 1064The fourth level name is one of: 1065.Bl -tag -width PROC_PID_LIMIT_MEMLOCKAA 1066.It Li PROC_PID_LIMIT_CPU 1067The maximum amount of cpu time (in seconds) to be used by each process. 1068.It Li PROC_PID_LIMIT_FSIZE 1069The largest size (in bytes) file that may be created. 1070.It Li PROC_PID_LIMIT_DATA 1071The maximum size (in bytes) of the data segment for a process; 1072this defines how far a program may extend its break with the 1073.Xr sbrk 2 1074system call. 1075.It Li PROC_PID_LIMIT_STACK 1076The maximum size (in bytes) of the stack segment for a process; 1077this defines how far a program's stack segment may be extended. 1078Stack extension is performed automatically by the system. 1079.It Li PROC_PID_LIMIT_CORE 1080The largest size (in bytes) 1081.Pa core 1082file that may be created. 1083.It Li PROC_PID_LIMIT_RSS 1084The maximum size (in bytes) to which a process's resident set size may 1085grow. 1086This imposes a limit on the amount of physical memory to be given to 1087a process; if memory is tight, the system will prefer to take memory 1088from processes that are exceeding their declared resident set size. 1089.It Li PROC_PID_LIMIT_MEMLOCK 1090The maximum size (in bytes) which a process may lock into memory 1091using the 1092.Xr mlock 2 1093function. 1094.It Li PROC_PID_LIMIT_NPROC 1095The maximum number of simultaneous processes for this user id. 1096.It Li PROC_PID_LIMIT_NOFILE 1097The maximum number of open files for this process. 1098.El 1099.Pp 1100The fifth level name is one of PROC_PID_LIMIT_TYPE_SOFT or 1101PROC_PID_LIMIT_TYPE_HARD, to select respectively the soft or hard limit. 1102Both are of type integer. 1103.El 1104.Pp 1105 1106.Sh CTL_USER 1107The string and integer information available for the CTL_USER level 1108is detailed below. 1109The changeable column shows whether a process with appropriate 1110privilege may change the value. 1111.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" -offset indent 1112.It Sy Pa Second level name Type Changeable 1113.It USER\_BC\_BASE\_MAX integer no 1114.It USER\_BC\_DIM\_MAX integer no 1115.It USER\_BC\_SCALE\_MAX integer no 1116.It USER\_BC\_STRING\_MAX integer no 1117.It USER\_COLL\_WEIGHTS\_MAX integer no 1118.It USER\_CS\_PATH string no 1119.It USER\_EXPR\_NEST\_MAX integer no 1120.It USER\_LINE\_MAX integer no 1121.It USER\_POSIX2\_CHAR\_TERM integer no 1122.It USER\_POSIX2\_C\_BIND integer no 1123.It USER\_POSIX2\_C\_DEV integer no 1124.It USER\_POSIX2\_FORT\_DEV integer no 1125.It USER\_POSIX2\_FORT\_RUN integer no 1126.It USER\_POSIX2\_LOCALEDEF integer no 1127.It USER\_POSIX2\_SW\_DEV integer no 1128.It USER\_POSIX2\_UPE integer no 1129.It USER\_POSIX2\_VERSION integer no 1130.It USER\_RE\_DUP\_MAX integer no 1131.It USER\_STREAM\_MAX integer no 1132.It USER\_TZNAME\_MAX integer no 1133.El 1134.Bl -tag -width "123456" 1135.Pp 1136.It Li USER_BC_BASE_MAX 1137The maximum ibase/obase values in the 1138.Xr bc 1 1139utility. 1140.It Li USER_BC_DIM_MAX 1141The maximum array size in the 1142.Xr bc 1 1143utility. 1144.It Li USER_BC_SCALE_MAX 1145The maximum scale value in the 1146.Xr bc 1 1147utility. 1148.It Li USER_BC_STRING_MAX 1149The maximum string length in the 1150.Xr bc 1 1151utility. 1152.It Li USER_COLL_WEIGHTS_MAX 1153The maximum number of weights that can be assigned to any entry of 1154the LC_COLLATE order keyword in the locale definition file. 1155.It Li USER_CS_PATH 1156Return a value for the 1157.Ev PATH 1158environment variable that finds all the standard utilities. 1159.It Li USER_EXPR_NEST_MAX 1160The maximum number of expressions that can be nested within 1161parenthesis by the 1162.Xr expr 1 1163utility. 1164.It Li USER_LINE_MAX 1165The maximum length in bytes of a text-processing utility's input 1166line. 1167.It Li USER_POSIX2_CHAR_TERM 1168Return 1 if the system supports at least one terminal type capable of 1169all operations described in POSIX 1003.2, otherwise 0. 1170.It Li USER_POSIX2_C_BIND 1171Return 1 if the system's C-language development facilities support the 1172C-Language Bindings Option, otherwise 0. 1173.It Li USER_POSIX2_C_DEV 1174Return 1 if the system supports the C-Language Development Utilities Option, 1175otherwise 0. 1176.It Li USER_POSIX2_FORT_DEV 1177Return 1 if the system supports the FORTRAN Development Utilities Option, 1178otherwise 0. 1179.It Li USER_POSIX2_FORT_RUN 1180Return 1 if the system supports the FORTRAN Runtime Utilities Option, 1181otherwise 0. 1182.It Li USER_POSIX2_LOCALEDEF 1183Return 1 if the system supports the creation of locales, otherwise 0. 1184.It Li USER_POSIX2_SW_DEV 1185Return 1 if the system supports the Software Development Utilities Option, 1186otherwise 0. 1187.It Li USER_POSIX2_UPE 1188Return 1 if the system supports the User Portability Utilities Option, 1189otherwise 0. 1190.It Li USER_POSIX2_VERSION 1191The version of POSIX 1003.2 with which the system attempts to comply. 1192.It Li USER_RE_DUP_MAX 1193The maximum number of repeated occurrences of a regular expression 1194permitted when using interval notation. 1195.ne 1i 1196.It Li USER_STREAM_MAX 1197The minimum maximum number of streams that a process may have open 1198at any one time. 1199.It Li USER_TZNAME_MAX 1200The minimum maximum number of types supported for the name of a 1201timezone. 1202.El 1203.Sh CTL_VM 1204The string and integer information available for the CTL_VM level 1205is detailed below. 1206The changeable column shows whether a process with appropriate 1207privilege may change the value. 1208.Bl -column "Second level nameXXXXXX" "struct loadavgXXX" -offset indent 1209.It Sy Pa Second level name Type Changeable 1210.It VM\_LOADAVG struct loadavg no 1211.It VM\_METER struct vmtotal no 1212.El 1213.Pp 1214.Bl -tag -width "123456" 1215.It Li VM_LOADAVG 1216Return the load average history. 1217The returned data consists of a 1218.Va struct loadavg . 1219.It Li VM_METER 1220Return the system wide virtual memory statistics. 1221The returned data consists of a 1222.Va struct vmtotal . 1223.El 1224.Sh CTL_DDB 1225The integer information available for the CTL_DDB level is detailed below. 1226The changeable column shows whether a process with appropriate 1227privilege may change the value. 1228.Bl -column "DBCTL_TABSTOPSXXX" "integerXXX" -offset indent 1229.It Sy Pa Second level name Type Changeable 1230.It DBCTL\_RADIX integer yes 1231.It DBCTL\_MAXOFF integer yes 1232.It DBCTL\_LINES integer yes 1233.It DBCTL\_TABSTOPS integer yes 1234.It DBCTL\_ONPANIC integer yes 1235.It DBCTL\_FROMCONSOLE integer yes 1236.El 1237.Pp 1238.Bl -tag -width "123456" 1239.It Li DBCTL_RADIX 1240The input and output radix. 1241.It Li DBCTL_MAXOFF 1242The maximum symbol offset. 1243.It Li DBCTL_LINES 1244Number of display lines. 1245.It Li DBCTL_TABSTOPS 1246Tab width. 1247.It Li DBCTL_ONPANIC 1248If non-zero, DDB will be entered when the kernel panics. 1249.It Li DBCTL_FROMCONSOLE 1250If not zero, DDB may be entered by sending a break on a serial 1251console or by a special key sequence on a graphics console. 1252.El 1253.Pp 1254These MIB nodes are also available as variables from within the 1255DDB. See 1256.Xr ddb 4 1257for more details. 1258.Sh RETURN VALUES 1259If the call to 1260.Nm 1261is successful, the number of bytes copied out is returned. 1262Otherwise \-1 is returned and 1263.Va errno 1264is set appropriately. 1265.Sh ERRORS 1266The following errors may be reported: 1267.Bl -tag -width Er 1268.It Bq Er EFAULT 1269The buffer 1270.Fa name , 1271.Fa oldp , 1272.Fa newp , 1273or length pointer 1274.Fa oldlenp 1275contains an invalid address. 1276.It Bq Er EINVAL 1277The 1278.Fa name 1279array is less than two or greater than CTL_MAXNAME. 1280.It Bq Er EINVAL 1281A non-null 1282.Fa newp 1283is given and its specified length in 1284.Fa newlen 1285is too large or too small. 1286.It Bq Er ENOMEM 1287The length pointed to by 1288.Fa oldlenp 1289is too short to hold the requested value. 1290.It Bq Er ENOTDIR 1291The 1292.Fa name 1293array specifies an intermediate rather than terminal name. 1294.It Bq Er EOPNOTSUPP 1295The 1296.Fa name 1297array specifies a value that is unknown. 1298.It Bq Er EPERM 1299An attempt is made to set a read-only value. 1300.It Bq Er EPERM 1301A process without appropriate privilege attempts to set a value. 1302.It Bq Er EPERM 1303An attempt to change a value protected by the current kernel security 1304level is made. 1305.El 1306.Sh FILES 1307.Bl -tag -width <netinet6/udp6Xvar.h> -compact 1308.It Pa <sys/sysctl.h> 1309definitions for top level identifiers, second level kernel and hardware 1310identifiers, and user level identifiers 1311.It Pa <sys/socket.h> 1312definitions for second level network identifiers 1313.It Pa <sys/gmon.h> 1314definitions for third level profiling identifiers 1315.It Pa <uvm/uvm_param.h> 1316definitions for second level virtual memory identifiers 1317.It Pa <netinet/in.h> 1318definitions for third level IPv4/v6 identifiers and 1319fourth level IPv4/v6 identifiers 1320.It Pa <netinet/icmp_var.h> 1321definitions for fourth level ICMP identifiers 1322.It Pa <netinet/icmp6.h> 1323definitions for fourth level ICMPv6 identifiers 1324.It Pa <netinet/tcp_var.h> 1325definitions for fourth level TCP identifiers 1326.It Pa <netinet/udp_var.h> 1327definitions for fourth level UDP identifiers 1328.It Pa <netinet6/udp6_var.h> 1329definitions for fourth level IPv6 UDP identifiers 1330.It Pa <netinet6/ipsec.h> 1331definitions for fourth level IPsec identifiers 1332.El 1333.Sh SEE ALSO 1334.Xr ipsec 4 , 1335.Xr sysctl 8 1336.Sh HISTORY 1337The 1338.Nm 1339function first appeared in 1340.Bx 4.4 . 1341