1.\" $NetBSD: sysctl.3,v 1.71 2000/12/21 01:10:52 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\_MAXPTYS integer yes 282.It KERN\_MAXVNODES integer yes 283.It KERN\_MBUF node not applicable 284.It KERN\_MEMLOCK integer no 285.It KERN\_MEMLOCK\_RANGE integer no 286.It KERN\_MEMORY\_PROTECTION integer no 287.It KERN\_MSGBUF char[\|] no 288.It KERN\_MSGBUFSIZE integer no 289.It KERN\_NGROUPS integer no 290.It KERN\_NTPTIME struct ntptimeval no 291.It KERN\_OSRELEASE string no 292.It KERN\_OSREV integer no 293.It KERN\_OSTYPE string no 294.It KERN\_POSIX1 integer no 295.It KERN\_PROC struct kinfo_proc no 296.It KERN\_PROC2 struct kinfo_proc2 no 297.It KERN\_PROC\_ARGS string no 298.It KERN\_PROF node not applicable 299.It KERN\_RAWPARTITION integer no 300.It KERN\_ROOT\_DEVICE string no 301.It KERN\_RTC\_OFFSET integer yes 302.It KERN\_SAVED\_IDS integer no 303.It KERN\_SECURELVL integer raise only 304.It KERN\_SYNCHRONIZED\_IO integer no 305.It KERN\_SYSVIPC\_INFO node not applicable 306.It KERN\_SYSVMSG integer no 307.It KERN\_SYSVSEM integer no 308.It KERN\_SYSVSHM integer no 309.It KERN\_VERSION string no 310.It KERN\_VNODE struct vnode no 311.El 312.ne 1i 313.Pp 314.Bl -tag -width "123456" 315.It Li KERN_ARGMAX 316The maximum bytes of argument to 317.Xr execve 2 . 318.It Li KERN_AUTONICETIME 319The number of seconds of cpu-time a non-root process may accumulate before 320having its priority lowered from the default to the value of KERN_AUTONICEVAL. 321If set to 0, automatic lowering of priority is not performed, and if set to -1 322all non-root processes are immediately lowered. 323.It Li KERN_AUTONICEVAL 324The priority assigned for automatically niced processes. 325.It Li KERN_BOOTTIME 326A 327.Va struct timeval 328structure is returned. 329This structure contains the time that the system was booted. 330.It Li KERN_CCPU 331The scheduler exponential decay value. 332.It Li KERN_CLOCKRATE 333A 334.Va struct clockinfo 335structure is returned. 336This structure contains the clock, statistics clock and profiling clock 337frequencies, the number of micro-seconds per hz tick, and the clock 338skew rate. 339.It Li KERN_CP_TIME 340Return an array if CPUSTATES longs is returned. This array contains the 341number of clock ticks spent in different CPU states. 342.It Li KERN_DEFCORENAME 343Default template for the name of core dump files (see also PROC_PID_CORENAME 344in the per-process variables CTL_PROC, and 345.Xr core 5 346for format of this template). The default value is 347.Nm %n.core 348and can be changed with the kernel configuration option 349.Cd options DEFCORENAME 350(see 351.Xr options 4 352). 353.It Li KERN_DOMAINNAME 354Get or set the YP domain name. 355.It Li KERN_FILE 356Return the entire file table. 357The returned data consists of a single 358.Va struct filehead 359followed by an array of 360.Va struct file , 361whose size depends on the current number of such objects in the system. 362.It Li KERN_FSCALE 363The kernel fixed-point scale factor. 364.It Li KERN_FSYNC 365Return 1 if the POSIX 1003.1b File Synchronization Option is available 366on this system, 367otherwise 0. 368.It Li KERN_HOSTID 369Get or set the host id. 370.It Li KERN_HOSTNAME 371Get or set the hostname. 372.It Li KERN_IOV_MAX 373Return the maximum number of 374.Va iovec 375structures that a process has available for use with 376.Xr preadv 2 , 377.Xr pwritev 2 , 378.Xr readv 2 , 379.Xr recvmsg 2 , 380.Xr sendmsg 2 381and 382.Xr writev 2 . 383.It Li KERN_JOB_CONTROL 384Return 1 if job control is available on this system, otherwise 0. 385.It Li KERN_LOGIN_NAME_MAX 386The size of the storage required for a login name, in bytes, 387including the terminating NUL. 388.It Li KERN_LOGSIGEXIT 389If this flag is non-zero, the kernel will 390.Xr log 9 391all process exits due to signals which create a 392.Xr core 5 393file, and whether the coredump was created. 394.It Li KERN_MAPPED_FILES 395Returns 1 if the POSIX 1003.1b Memory Mapped Files Option is available 396on this system, 397otherwise 0. 398.It Li KERN_MAXFILES 399The maximum number of open files that may be open in the system. 400.It Li KERN_MAXPARTITIONS 401The maximum number of partitions allowed per disk. 402.It Li KERN_MAXPROC 403The maximum number of simultaneous processes the system will allow. 404.It Li KERN_MAXPTYS 405The maximum number of pseudo terminals. This value can be both 406raised and lowered, though it cannot 407be set lower than number of currently used ptys. See also 408.Xr pty 4 . 409.It Li KERN_MAXVNODES 410The maximum number of vnodes available on the system. This can only 411be raised. 412.It Li KERN_MBUF 413Return information about the mbuf control variables. 414the third level names for the mbuf variables are detailed below. 415The changeable column shows whether a process with appropriate 416privilege may change the value. 417.Bl -column "MBUFXNMBCLUSTERSXXX" "struct integerXXX" -offset indent 418.It MBUF\_MSIZE integer yes 419.It MBUF\_MCLBYTES integer yes 420.It MBUF\_NMBCLUSTERS integer yes 421.It MBUF\_MBLOWAT integer yes 422.It MBUF\_MCLLOWAT integer yes 423.El 424.Pp 425The variables are as follows: 426.Bl -tag -width "123456" 427.It Li MBUF_MSIZE 428The mbuf base size. 429.It Li MBUF_MCLBYTES 430The mbuf cluster size. 431.It Li MBUF_NMBCLUSTERS 432The limit on the number of mbuf clusters. 433The variable can only be increased, and only increased on machines with 434direct-mapped pool pages 435.It Li MBUF_MBLOWAT 436The mbuf low water mark. 437.It Li MBUF_MCLLOWAT 438The mbuf cluster low water mark. 439.El 440.It Li KERN_MEMLOCK 441Returns 1 if the POSIX 1003.1b Process Memory Locking Option is available 442on this system, 443otherwise 0. 444.It Li KERN_MEMLOCK_RANGE 445Returns 1 if the POSIX 1003.1b Range Memory Locking Option is available 446on this system, 447otherwise 0. 448.It Li KERN_MEMORY_PROTECTION 449Returns 1 if the POSIX 1003.1b Memory Protection Option is available 450on this system, 451otherwise 0. 452.It Li KERN_MSGBUF 453The kernel message buffer, rotated so that the head of the circular kernel 454message buffer is returned at the start of the buffer specified by 455.Fa oldp . 456The returned data may contain NUL bytes. 457.It Li KERN_MSGBUFSIZE 458The maximum number of characters that the kernel message buffer can hold. 459.It Li KERN_NGROUPS 460The maximum number of supplemental groups. 461.It Li KERN_NO_TRUNC 462Return 1 if file names longer than KERN_NAME_MAX are truncated. 463.It Li KERN_NTPTIME 464A 465.Va struct ntptimeval 466structure is returned. 467This structure contains data used by the 468.Xr ntpd 8 469program. 470.It Li KERN_OSRELEASE 471The system release string. 472.It Li KERN_OSREV 473The system revision string. 474.It Li KERN_OSTYPE 475The system type string. 476.It Li KERN_PATH_MAX 477The maximum number of bytes in a pathname. 478.It Li KERN_POSIX1 479The version of ISO/IEC 9945 (POSIX 1003.1) with which the system 480attempts to comply. 481.It Li KERN_PROC 482Return the entire process table, or a subset of it. 483An array of 484.Va struct kinfo_proc 485structures is returned, 486whose size depends on the current number of such objects in the system. 487The third and fourth level names are as follows: 488.Bl -column "Third level nameXXXXXX" "Fourth level is:XXXXXX" -offset indent 489.It Pa Third level name Fourth level is: 490.It KERN\_PROC\_ALL None 491.It KERN\_PROC\_PID A process ID 492.It KERN\_PROC\_PGRP A process group 493.It KERN\_PROC\_SESSION A session ID 494.It KERN\_PROC\_TTY A tty device 495.It KERN\_PROC\_UID A user ID 496.It KERN\_PROC\_RUID A real user ID 497.It KERN\_PROC\_GID A group ID 498.It KERN\_PROC\_RGID A real group ID 499.El 500.It Li KERN_PROC2 501As for KERN_PROC, but an array of 502.Va struct kinfo_proc2 503structures are returned. The fifth level name is the size of the 504.Va struct kinfo_proc2 505and the sixth level name is the number of structures to return. 506.It Li KERN_PROC_ARGS 507Return the argv or environment strings (or the number thereof) 508of a process. Multiple strings are returned separated by NUL 509characters. The third level name is the process ID. The fourth 510level name is as follows: 511.Bl -column "Third level nameXXXXXX" -offset indent 512.It KERN\_PROC\_ARGV The argv strings 513.It KERN\_PROC\_NARGV The number of argv strings 514.It KERN\_PROC\_ENV The environ strings 515.It KERN\_PROC\_NENV The number of environ strings 516.El 517.It Li KERN_PROF 518Return profiling information about the kernel. 519If the kernel is not compiled for profiling, 520attempts to retrieve any of the KERN_PROF values will 521fail with EOPNOTSUPP. 522The third level names for the string and integer profiling information 523is detailed below. 524The changeable column shows whether a process with appropriate 525privilege may change the value. 526.Bl -column "GPROFXGMONPARAMXXX" "struct gmonparamXXX" -offset indent 527.It Sy Pa Third level name Type Changeable 528.It GPROF\_STATE integer yes 529.It GPROF\_COUNT u_short[\|] yes 530.It GPROF\_FROMS u_short[\|] yes 531.It GPROF\_TOS struct tostruct yes 532.It GPROF\_GMONPARAM struct gmonparam no 533.El 534.Pp 535The variables are as follows: 536.Bl -tag -width "123456" 537.It Li GPROF_STATE 538Returns GMON_PROF_ON or GMON_PROF_OFF to show that profiling 539is running or stopped. 540.It Li GPROF_COUNT 541Array of statistical program counter counts. 542.It Li GPROF_FROMS 543Array indexed by program counter of call-from points. 544.It Li GPROF_TOS 545Array of 546.Va struct tostruct 547describing destination of calls and their counts. 548.It Li GPROF_GMONPARAM 549Structure giving the sizes of the above arrays. 550.El 551.It Li KERN_RAWPARTITION 552The raw partition of a disk (a == 0). 553.It Li KERN_ROOT_DEVICE 554The name of the root device. 555.It Li KERN_RTC_OFFSET 556Return the offset of real time clock from UTC in minutes. 557.It Li KERN_SAVED_IDS 558Returns 1 if saved set-group and saved set-user ID is available. 559.It Li KERN_SECURELVL 560The system security level. 561This level may be raised by processes with appropriate privilege. 562It may only be lowered by process 1. 563.It Li KERN_SYNCHRONIZED_IO 564Returns 1 if the POSIX 1003.1b Synchronized I/O Option is available 565on this system, 566otherwise 0. 567.It Li KERN_SYSVIPC_INFO 568Return System V style IPC configuration and run-time information. 569The third level name selects the System V style IPC facility. 570.Bl -column "KERN_SYSVIPC_MSG_INFOXXX" "struct shm_sysctl_infoXXX" -offset indent 571.It Sy Pa Third level name Type 572.It KERN\_SYSVIPC\_MSG\_INFO struct msg_sysctl_info 573.It KERN\_SYSVIPC\_SEM\_INFO struct sem_sysctl_info 574.It KERN\_SYSVIPC\_SHM\_INFO struct shm_sysctl_info 575.El 576.Pp 577.Bl -tag -width "123456" 578.It Li KERN_SYSVIPC_MSG_INFO 579Return information on the System V style message facility. The 580.Sy msg_sysctl_info 581structure is defined in 582.Aq Pa sys/msg.h . 583.It Li KERN_SYSVIPC_SEM_INFO 584Return information on the System V style semaphore facility. The 585.Sy sem_sysctl_info 586structure is defined in 587.Aq Pa sys/sem.h . 588.It Li KERN_SYSVIPC_SHM_INFO 589Return information on the System V style shared memory facility. The 590.Sy shm_sysctl_info 591structure is defined in 592.Aq Pa sys/shm.h . 593.El 594.It Li KERN_SYSVMSG 595Returns 1 if System V style message queue functionality is available 596on this system, 597otherwise 0. 598.It Li KERN_SYSVSEM 599Returns 1 if System V style semaphore functionality is available 600on this system, 601otherwise 0. 602.It Li KERN_SYSVSHM 603Returns 1 if System V style share memory functionality is available 604on this system, 605otherwise 0. 606.It Li KERN_VERSION 607The system version string. 608.It Li KERN_VNODE 609Return the entire vnode table. 610Note, the vnode table is not necessarily a consistent snapshot of 611the system. 612The returned data consists of an array whose size depends on the 613current number of such objects in the system. 614Each element of the array contains the kernel address of a vnode 615.Va struct vnode * 616followed by the vnode itself 617.Va struct vnode . 618.El 619.Sh CTL_MACHDEP 620The set of variables defined is architecture dependent. 621Most architectures define at least the following variables. 622.Bl -column "CONSOLE_DEVICEXXX" "integerXXX" -offset indent 623.It Sy Pa Second level name Type Changeable 624.It Li CPU_CONSDEV dev_t no 625.El 626.Sh CTL_NET 627The string and integer information available for the CTL_NET level 628is detailed below. 629The changeable column shows whether a process with appropriate 630privilege may change the value. 631.Bl -column "Second level nameXXXXXX" "routing messagesXXX" -offset indent 632.It Sy Pa Second level name Type Changeable 633.It PF\_ROUTE routing messages no 634.It PF\_INET IPv4 values yes 635.It PF\_INET6 IPv6 values yes 636.El 637.Pp 638.Bl -tag -width "123456" 639.It Li PF_ROUTE 640Return the entire routing table or a subset of it. 641The data is returned as a sequence of routing messages (see 642.Xr route 4 643for the header file, format and meaning). 644The length of each message is contained in the message header. 645.Pp 646The third level name is a protocol number, which is currently always 0. 647The fourth level name is an address family, which may be set to 0 to 648select all address families. 649The fifth and sixth level names are as follows: 650.Bl -column "Fifth level nameXXXXXX" "Sixth level is:XXX" -offset indent 651.It Pa Fifth level name Sixth level is: 652.It NET\_RT\_FLAGS rtflags 653.It NET\_RT\_DUMP None 654.It NET\_RT\_IFLIST None 655.El 656.It Li PF_INET 657Get or set various global information about the IPv4 658.Pq Internet Protocol version 4 . 659The third level name is the protocol. 660The fourth level name is the variable name. 661The currently defined protocols and names are: 662.Bl -column "Protocol name" "Variable nameXX" "integer" "yes" -offset indent 663.It Pa Protocol name Variable name Type Changeable 664.It ip forwarding integer yes 665.It ip redirect integer yes 666.It ip ttl integer yes 667.It ip forwsrcrt integer yes 668.It ip directed-broadcast integer yes 669.It ip allowsrcrt integer yes 670.It ip subnetsarelocal integer yes 671.It ip mtudisc integer yes 672.It ip anonportmin integer yes 673.It ip anonportmax integer yes 674.It ip mtudisctimeout integer yes 675.It ip gifttl integer yes 676.It ip lowportmin integer yes 677.It ip lowportmax integer yes 678.It icmp maskrepl integer yes 679.It icmp errppslimit integer yes 680.It tcp rfc1323 integer yes 681.It tcp sendspace integer yes 682.It tcp recvspace integer yes 683.It tcp mssdflt integer yes 684.It tcp syn_cache_limit integer yes 685.It tcp syn_bucket_limit integer yes 686.It tcp syn_cache_interval integer yes 687.It tcp init_win integer yes 688.It tcp mss_ifmtu integer yes 689.It tcp sack integer yes 690.It tcp win_scale integer yes 691.It tcp timestamps integer yes 692.It tcp compat_42 integer yes 693.It tcp cwm integer yes 694.It tcp cwm_burstsize integer yes 695.It tcp ack_on_push integer yes 696.It tcp keepidle integer yes 697.It tcp keepintvl integer yes 698.It tcp keepcnt integer yes 699.It tcp slowhz integer no 700.It tcp newreno integer yes 701.It tcp log_refused integer yes 702.It tcp rstppslimit integer yes 703.It udp checksum integer yes 704.It udp sendspace integer yes 705.It udp recvspace integer yes 706.El 707.Pp 708The variables are as follows: 709.Bl -tag -width "123456" 710.It Li ip.forwarding 711Returns 1 when IP forwarding is enabled for the host, 712meaning that the host is acting as a router. 713.It Li ip.redirect 714Returns 1 when ICMP redirects may be sent by the host. 715This option is ignored unless the host is routing IP packets, 716and should normally be enabled on all systems. 717.It Li ip.ttl 718The maximum time-to-live (hop count) value for an IP packet sourced by 719the system. 720This value applies to normal transport protocols, not to ICMP. 721.It Li ip.forwsrcrt 722Returns 1 when forwarding of source-routed packets is enabled for 723the host. This value may only be changed if the kernel security 724level is less than 1. 725.It Li ip.directed-broadcast 726Returns 1 if directed broadcast behavior is enabled for the host. 727.It Li ip.allowsrcrt 728Returns 1 if the host accepts source routed packets. 729.It Li ip.subnetsarelocal 730Returns 1 if subnets are to be considered local addresses. 731.It Li ip.mtudisc 732Returns 1 if Path MTU Discovery is enabled. 733.It Li ip.anonportmin 734The lowest port number to use for TCP and UDP ephemeral port allocation. 735This cannot be set to less than 1024 or greater than 65535. 736.It Li ip.anonportmax 737The highest port number to use for TCP and UDP ephemeral port allocation. 738This cannot be set to less than 1024 or greater than 65535, and must 739be greater than 740.Li ip.anonportmin . 741.It Li ip.mtudisctimeout 742Returns the number of seconds in which a route added by the Path MTU 743Discovery engine will time out. When the route times out, the Path 744MTU Discovery engine will attempt to probe a larger path MTU. 745.It Li ip.gifttl 746The maximum time-to-live (hop count) value for an IPv4 packet generated by 747.Xr gif 4 748tunnel interface. 749.It Li ip.lowportmin 750The lowest port number to use for TCP and UDP reserved port allocation. 751This cannot be set to less than 0 or greater than 1024, and must 752be smaller than 753.Li ip.lowportmax . 754.It Li ip.lowportmax 755The highest port number to use for TCP and UDP reserved port allocation. 756This cannot be set to less than 0 or greater than 1024, and must 757be greater than 758.Li ip.lowportmin . 759.It Li icmp.maskrepl 760Returns 1 if ICMP network mask requests are to be answered. 761.It Li icmp.errppslimit 762The variable specifies the maximum number of outgoing ICMP error messages, 763per second. 764ICMP error messages that exceeded the value are subject to rate limitation 765and will not go out from the node. 766Negative value disables rate limitation. 767.It Li tcp.rfc1323 768Returns 1 if RFC1323 extensions to TCP are enabled. 769.It Li tcp.sendspace 770Returns the default TCP send buffer size. 771.It Li tcp.recvspace 772Returns the default TCP receive buffer size. 773.It Li tcp.mssdflt 774Returns the default maximum segment size both advertsized to the peer 775and to use when the peer does not advertize a maximum segment size to 776us during connection setup. Do not change this value unless you really 777know what you are doing. 778.It Li tcp.syn_cache_limit 779Returns the maximum number of entries allowed in the TCP compressed state 780engine. 781.It Li tcp.syn_bucket_limit 782Returns the maximum number of entries allowed per hash bucket in the TCP 783compressed state engine. 784.It Li tcp.syn_cache_interval 785Returns the TCP compressed state engine's timer interval. 786.It Li tcp.init_win 787Returns a value indicating the TCP initial congestion window. If this 788value is 0, an auto-tuning algorithm designed to use an initial window 789of approximately 4K bytes is in use. Otherwise, this value indicates 790a fixed number of packets. 791.It Li tcp.mss_ifmtu 792Returns 1 if TCP calculates the outgoing maximum segment size based on 793the MTU of the appropriate interface. Otherwise, it is calculated based on 794the greater of the MTU of the interface, and the largest (non-loopback) 795interface MTU on the system. 796.It Li tcp.sack 797TCP Selective ACKnowledgement (RFC 2018) is not implemented in 798.Nx 799at this time. 800Changing this value will have no effect. 801.It Li tcp.win_scale 802If rfc1323 is enabled, a value of 1 indicates RFC1323 window scale options, 803for increasing the TCP window size, are enabled. 804.It Li tcp.timestamps 805If rfc1323 is enabled, a value of 1 indicates RFC1323 time stamp options, 806used for measuring TCP round trip times, are enabled. 807.It Li tcp.compat_42 808Returns 1 if work-arounds for bugs in the 4.2BSD TCP implementation are 809enabled. Use of this option is not recommended, although it may be 810required in order to communicate with extremely old TCP implementations. 811.It Li tcp.cwm 812Returns 1 if use of the Hughes/Touch/Heidemann Congestion Window Monitoring 813algorithm is enabled. This algorithm prevents line-rate bursts of packets 814that could otherwise occur when data begins flowing on an idle TCP 815connection. These line-rate bursts can contribute to network and router 816congestion. This can be particularly useful on World Wide Web servers 817which support HTTP/1.1, which has lingering connections. 818.It Li tcp.cwm_burstsize 819Returns the Congestion Window Monitoring allowed burst size, in terms 820of packet count. 821.It Li tcp.ack_on_push 822Returns 1 if TCP is to immediately transmit an ACK upon reception of 823a packet with PUSH set. This can avoid losing a round trip time in some 824rare situations, but has the caveat of potentially defeating TCP's delayed 825ACK algorithm. Use of this option is generally not recommended, but 826the variable exists in case your configuration really needs it. 827.It Li tcp.keepidle 828Time a connection must be idle before keepalives are sent (if keepalives 829are enabled for the connection). See also tcp.slowhz. 830.It Li tcp.keepintvl 831Time after a keepalive probe is sent until, in the absence of any response, 832another probe is sent. See also tcp.slowhz. 833.It Li tcp.keepcnt 834Number of keepalive probes sent before declaring a connection dead. If 835set to zero, there is no limit; keepalives will be sent until some kind of 836response is received from the peer. 837.It Li tcp.slowhz 838The units for tcp.keepidle and tcp.keepintvl; those variables are in ticks 839of a clock that ticks tcp.slowhz times per second. (That is, their values 840must be divided by the tcp.slowhz value to get times in seconds.) 841.It Li tcp.newreno 842Returns 1 if the use of J. Hoe's NewReno congestion control algorithm is 843enabled. This algorithm improves the start-up behavior of TCP connections. 844.It Li tcp.log_refused 845Returns 1 if refused TCP connections to the host will be logged. 846.It Li tcp.rstppslimit 847The variable specifies the maximum number of outgoing TCP RST packets, 848per second. 849TCP RST packet that exceeded the value are subject to rate limitation 850and will not go out from the node. 851Negative value disables rate limitation. 852.It Li udp.checksum 853Returns 1 when UDP checksums are being computed and checked. 854Disabling UDP checksums is strongly discouraged. 855.It Li udp.sendspace 856Returns the default UDP send buffer size. 857.It Li udp.recvspace 858Returns the default UDP receive buffer size. 859.El 860.Pp 861For variables net.*.ipsec, please refer to 862.Xr ipsec 4 . 863.It Li PF_INET6 864Get or set various global information about the IPv6 865.Pq Internet Protocol version 6 . 866The third level name is the protocol. 867The fourth level name is the variable name. 868The currently defined protocols and names are: 869.Bl -column "Protocol name" "Variable nameXX" "integer" "yes" -offset indent 870.It Pa Protocol name Variable name Type Changeable 871.It ip6 forwarding integer yes 872.It ip6 redirect integer yes 873.It ip6 hlim integer yes 874.It ip6 maxfragpackets integer yes 875.It ip6 accept_rtadv integer yes 876.It ip6 keepfaith integer yes 877.It ip6 log_interval integer yes 878.It ip6 hdrnestlimit integer yes 879.It ip6 dad_count integer yes 880.It ip6 auto_flowlabel integer yes 881.It ip6 defmcasthlim integer yes 882.It ip6 gif_hlim integer yes 883.It ip6 kame_version string no 884.It ip6 use_deprecated integer yes 885.It ip6 rr_prune integer yes 886.It ip6 bindv6only integer yes 887.It ip6 anonportmin integer yes 888.It ip6 anonportmax integer yes 889.It ip6 lowportmin integer yes 890.It ip6 lowportmax integer yes 891.It icmp6 rediraccept integer yes 892.It icmp6 redirtimeout integer yes 893.It icmp6 nd6_prune integer yes 894.It icmp6 nd6_delay integer yes 895.It icmp6 nd6_umaxtries integer yes 896.It icmp6 nd6_mmaxtries integer yes 897.It icmp6 nd6_useloopback integer yes 898.It icmp6 nodeinfo integer yes 899.It icmp6 errppslimit integer yes 900.It icmp6 nd6_maxnudhint integer yes 901.It icmp6 mtudisc_hiwat integer yes 902.It icmp6 mtudisc_lowat integer yes 903.It udp6 sendspace integer yes 904.It udp6 recvspace integer yes 905.El 906.Pp 907The variables are as follows: 908.Bl -tag -width "123456" 909.It Li ip6.forwarding 910Returns 1 when IPv6 forwarding is enabled for the node, 911meaning that the node is acting as a router. 912Returns 0 when IPv6 forwarding is disabled for the node, 913meaning that the node is acting as a host. 914IPv6 specification defines node behavior for 915.Dq router 916case and 917.Dq host 918case quite differently, and changing this variable during operation 919may cause serious trouble. 920It is recommended to configure the variable at bootstrap time, 921and bootstrap time only. 922.It Li ip6.redirect 923Returns 1 when ICMPv6 redirects may be sent by the node. 924This option is ignored unless the node is routing IP packets, 925and should normally be enabled on all systems. 926.It Li ip6.hlim 927The default hop limit value for an IPv6 unicast packet sourced by the node. 928This value applies to all the transport protocols on top of IPv6. 929There are APIs to override the value, as documented in 930.Xr ip6 4 . 931.It Li ip6.maxfragpackets 932The maximum number of fragmented packets the node will accept. 9330 means that the node will not accept any fragmented packets. 934-1 means that the node will accept as many fragmented packets as it receives. 935The flag is provided basically for avoiding possible DoS attacks. 936.It Li ip6.accept_rtadv 937If set to non-zero, the node will accept ICMPv6 router advertisement packets 938and autoconfigures address prefixes and default routers. 939The node must be a host 940.Pq not a router 941for the option to be meaningful. 942.It Li ip6.keepfaith 943If set to non-zero, it enables 944.Dq FAITH 945TCP relay IPv6-to-IPv4 translator code in the kernel. 946Refer 947.Xr faith 4 948and 949.Xr faithd 8 950for detail. 951.It Li ip6.log_interval 952The variable controls amount of logs generated by IPv6 packet 953forwarding engine, by seting interval between log output 954.Pq in seconds . 955.It Li ip6.hdrnestlimit 956The number of IPv6 extension headers permitted on incoming IPv6 packets. 957If set to 0, the node will accept as many extension headers as possible. 958.It Li ip6.dad_count 959The variable cofigures number of IPv6 DAD 960.Pq duplicated address detection 961probe packets. 962The packets will be generated when IPv6 interface addresses are configured. 963.It Li ip6.auto_flowlabel 964On connected transport protocol packets, 965fill IPv6 flowlabel field to help intermediate routers to identify packet flows. 966.It Li ip6.defmcasthlim 967The default hop limit value for an IPv6 multicast packet sourced by the node. 968This value applies to all the transport protocols on top of IPv6. 969There are APIs to override the value, as documented in 970.Xr ip6 4 . 971.It Li ip6.gif_hlim 972The maximum hop limit value for an IPv6 packet generated by 973.Xr gif 4 974tunnel interface. 975.It Li ip6.kame_version 976The string identifies the version of KAME IPv6 stack implemented in the kernel. 977.It Li ip6.use_deprecated 978The variable controls use of deprecated address, specified in RFC2462 5.5.4. 979.It Li ip6.rr_prune 980The variable specifies interval between IPv6 router renumbering prefix 981babysitting, in seconds. 982.It Li ip6.bindv6only 983The variable specifies initial value for 984.Dv IPV6_BINDV6ONLY 985socket option for 986.Dv AF_INET6 987socket. 988Please refer to 989.Xr ip6 4 990for detail. 991.It Li ip6.anonportmin 992The lowest port number to use for TCP and UDP ephemeral port allocation. 993This cannot be set to less than 1024 or greater than 65535. 994.It Li ip6.anonportmax 995The highest port number to use for TCP and UDP ephemeral port allocation. 996This cannot be set to less than 1024 or greater than 65535, and must 997be greater than 998.Li ip6.anonportmin . 999.It Li ip6.lowportmin 1000The lowest port number to use for TCP and UDP reserved port allocation. 1001This cannot be set to less than 0 or greater than 1024, and must 1002be smaller than 1003.Li ip6.lowportmax . 1004.It Li ip6.lowportmax 1005The highest port number to use for TCP and UDP reserved port allocation. 1006This cannot be set to less than 0 or greater than 1024, and must 1007be greater than 1008.Li ip6.lowportmin . 1009.It Li icmp6.rediraccept 1010If set to non-zero, the host will accept ICMPv6 redirect packets. 1011Note that IPv6 routers will never accept ICMPv6 redirect packets, 1012and the variable is meaningful on IPv6 hosts 1013.Pq non-router 1014only. 1015.It Li icmp6.redirtimeout 1016The variable specifies lifetime of routing entries generated by incoming 1017ICMPv6 redirect. 1018.It Li icmp6.nd6_prune 1019The variable specifies interval between IPv6 neighbor cache babysitting, 1020in seconds. 1021.It Li icmp6.nd6_delay 1022The variable specifies 1023.Dv DELAY_FIRST_PROBE_TIME 1024timing constant in IPv6 neighbor discovery specification 1025.Pq RFC2461 , 1026in seconds. 1027.It Li icmp6.nd6_umaxtries 1028The variable specifies 1029.Dv MAX_UNICAST_SOLICIT 1030constant in IPv6 neighbor discovery specification 1031.Pq RFC2461 . 1032.It Li icmp6.nd6_mmaxtries 1033The variable specifies 1034.Dv MAX_MULTICAST_SOLICIT 1035constant in IPv6 neighbor discovery specification 1036.Pq RFC2461 . 1037.It Li icmp6.nd6_useloopback 1038If set to non-zero, kernel IPv6 stack will use loopback interface for 1039local traffic. 1040.It Li icmp6.nodeinfo 1041The variable enables, or disables, kernel support for 1042ICMPv6 node information query/reply. 1043.It Li icmp6.errppslimit 1044The variable specifies the maximum number of outgoing ICMPv6 error messages, 1045per second. 1046ICMPv6 error messages that exceeded the value are subject to rate limitation 1047and will not go out from the node. 1048Negative value disables rate limitation. 1049.It Li icmp6.nd6_maxnudhint 1050IPv6 neighbor discovery permits upper layer protocols to supply reachability 1051hints, to avoid unnecessary neighbor discovery exchanges. 1052The variable defines the number of consecutive hints the neighbor discovery 1053layer will take. 1054For example, by setting the variable to 3, neighbor discovery layer 1055will take 3 consecutive hints in maximum. 1056After receiving 3 hints, neighbor discovery layer will perform 1057normal neighbor discovery process. 1058.It Li icmp6.mtudisc_hiwat 1059.It Li icmp6.mtudisc_lowat 1060The variables define the maximum number of routing table entries, 1061created due to path MTU discovery 1062.Pq prevents denial-of-service attacks with ICMPv6 too big messages . 1063When IPv6 path MTU discovery happens, we keep path MTU information into 1064the routing table. 1065If the number of routing table entries exceed the value, 1066the kernel will not attempt to keep the path MTU information. 1067.Li icmp6.mtudisc_hiwat 1068is used when we have verified ICMPv6 too big messages. 1069.Li icmp6.mtudisc_lowat 1070is used when we have unverified ICMPv6 too big messages. 1071Verification is performed by using address/port pairs kept in connected pcbs. 1072.El 1073.Pp 1074We reuse net.*.tcp for 1075.Tn TCP 1076over 1077.Tn IPv6 , 1078and therefore we do not have variables net.*.tcp6. 1079Variables net.inet6.udp6 have identical meaning to net.inet.udp. 1080Please refer to 1081.Li PF_INET 1082section above. 1083For variables net.*.ipsec6, please refer to 1084.Xr ipsec 4 . 1085.El 1086.Sh CTL_PROC 1087The string and integer information available for the CTL_PROC 1088is detailed below. 1089The changeable column shows whether a process with appropriate 1090privilege may change the value. 1091These values are per-process, and as such may change from one process 1092to another. When a process is created, the default values are inherited from 1093its parent. When a set-user-ID or set-group-ID binary is executed, the 1094value of PROC_PID_CORENAME is reset to the system default value. 1095The second level name is either the magic value PROC_CURPROC, which 1096points to the current process, or the PID of the target process. 1097.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" "yes" -offset indent 1098.It Sy Pa Third level name Type Changeable 1099.It PROC\_PID\_CORENAME string yes 1100.It PROC\_PID\_LIMIT node not applicable 1101.El 1102.Bl -tag -width "123456" 1103.Pp 1104.It Li PROC_PID_CORENAME 1105The template used for the core dump file name (see 1106.Xr core 5 1107for details). The base name must either be 1108.Nm core 1109or end with the suffix ``.core'' (the super-user may set arbitrary names). By 1110default it points to KERN_DEFCORENAME. 1111.It Li PROC_PID_LIMIT 1112Return resources limits, as defined for the 1113.Xr getrlimit 2 1114and 1115.Xr setrlimit 2 1116system calls. 1117The fourth level name is one of: 1118.Bl -tag -width PROC_PID_LIMIT_MEMLOCKAA 1119.It Li PROC_PID_LIMIT_CPU 1120The maximum amount of cpu time (in seconds) to be used by each process. 1121.It Li PROC_PID_LIMIT_FSIZE 1122The largest size (in bytes) file that may be created. 1123.It Li PROC_PID_LIMIT_DATA 1124The maximum size (in bytes) of the data segment for a process; 1125this defines how far a program may extend its break with the 1126.Xr sbrk 2 1127system call. 1128.It Li PROC_PID_LIMIT_STACK 1129The maximum size (in bytes) of the stack segment for a process; 1130this defines how far a program's stack segment may be extended. 1131Stack extension is performed automatically by the system. 1132.It Li PROC_PID_LIMIT_CORE 1133The largest size (in bytes) 1134.Pa core 1135file that may be created. 1136.It Li PROC_PID_LIMIT_RSS 1137The maximum size (in bytes) to which a process's resident set size may 1138grow. 1139This imposes a limit on the amount of physical memory to be given to 1140a process; if memory is tight, the system will prefer to take memory 1141from processes that are exceeding their declared resident set size. 1142.It Li PROC_PID_LIMIT_MEMLOCK 1143The maximum size (in bytes) which a process may lock into memory 1144using the 1145.Xr mlock 2 1146function. 1147.It Li PROC_PID_LIMIT_NPROC 1148The maximum number of simultaneous processes for this user id. 1149.It Li PROC_PID_LIMIT_NOFILE 1150The maximum number of open files for this process. 1151.El 1152.Pp 1153The fifth level name is one of PROC_PID_LIMIT_TYPE_SOFT or 1154PROC_PID_LIMIT_TYPE_HARD, to select respectively the soft or hard limit. 1155Both are of type integer. 1156.El 1157.Pp 1158 1159.Sh CTL_USER 1160The string and integer information available for the CTL_USER level 1161is detailed below. 1162The changeable column shows whether a process with appropriate 1163privilege may change the value. 1164.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" -offset indent 1165.It Sy Pa Second level name Type Changeable 1166.It USER\_BC\_BASE\_MAX integer no 1167.It USER\_BC\_DIM\_MAX integer no 1168.It USER\_BC\_SCALE\_MAX integer no 1169.It USER\_BC\_STRING\_MAX integer no 1170.It USER\_COLL\_WEIGHTS\_MAX integer no 1171.It USER\_CS\_PATH string no 1172.It USER\_EXPR\_NEST\_MAX integer no 1173.It USER\_LINE\_MAX integer no 1174.It USER\_POSIX2\_CHAR\_TERM integer no 1175.It USER\_POSIX2\_C\_BIND integer no 1176.It USER\_POSIX2\_C\_DEV integer no 1177.It USER\_POSIX2\_FORT\_DEV integer no 1178.It USER\_POSIX2\_FORT\_RUN integer no 1179.It USER\_POSIX2\_LOCALEDEF integer no 1180.It USER\_POSIX2\_SW\_DEV integer no 1181.It USER\_POSIX2\_UPE integer no 1182.It USER\_POSIX2\_VERSION integer no 1183.It USER\_RE\_DUP\_MAX integer no 1184.It USER\_STREAM\_MAX integer no 1185.It USER\_TZNAME\_MAX integer no 1186.El 1187.Bl -tag -width "123456" 1188.Pp 1189.It Li USER_BC_BASE_MAX 1190The maximum ibase/obase values in the 1191.Xr bc 1 1192utility. 1193.It Li USER_BC_DIM_MAX 1194The maximum array size in the 1195.Xr bc 1 1196utility. 1197.It Li USER_BC_SCALE_MAX 1198The maximum scale value in the 1199.Xr bc 1 1200utility. 1201.It Li USER_BC_STRING_MAX 1202The maximum string length in the 1203.Xr bc 1 1204utility. 1205.It Li USER_COLL_WEIGHTS_MAX 1206The maximum number of weights that can be assigned to any entry of 1207the LC_COLLATE order keyword in the locale definition file. 1208.It Li USER_CS_PATH 1209Return a value for the 1210.Ev PATH 1211environment variable that finds all the standard utilities. 1212.It Li USER_EXPR_NEST_MAX 1213The maximum number of expressions that can be nested within 1214parenthesis by the 1215.Xr expr 1 1216utility. 1217.It Li USER_LINE_MAX 1218The maximum length in bytes of a text-processing utility's input 1219line. 1220.It Li USER_POSIX2_CHAR_TERM 1221Return 1 if the system supports at least one terminal type capable of 1222all operations described in POSIX 1003.2, otherwise 0. 1223.It Li USER_POSIX2_C_BIND 1224Return 1 if the system's C-language development facilities support the 1225C-Language Bindings Option, otherwise 0. 1226.It Li USER_POSIX2_C_DEV 1227Return 1 if the system supports the C-Language Development Utilities Option, 1228otherwise 0. 1229.It Li USER_POSIX2_FORT_DEV 1230Return 1 if the system supports the FORTRAN Development Utilities Option, 1231otherwise 0. 1232.It Li USER_POSIX2_FORT_RUN 1233Return 1 if the system supports the FORTRAN Runtime Utilities Option, 1234otherwise 0. 1235.It Li USER_POSIX2_LOCALEDEF 1236Return 1 if the system supports the creation of locales, otherwise 0. 1237.It Li USER_POSIX2_SW_DEV 1238Return 1 if the system supports the Software Development Utilities Option, 1239otherwise 0. 1240.It Li USER_POSIX2_UPE 1241Return 1 if the system supports the User Portability Utilities Option, 1242otherwise 0. 1243.It Li USER_POSIX2_VERSION 1244The version of POSIX 1003.2 with which the system attempts to comply. 1245.It Li USER_RE_DUP_MAX 1246The maximum number of repeated occurrences of a regular expression 1247permitted when using interval notation. 1248.ne 1i 1249.It Li USER_STREAM_MAX 1250The minimum maximum number of streams that a process may have open 1251at any one time. 1252.It Li USER_TZNAME_MAX 1253The minimum maximum number of types supported for the name of a 1254timezone. 1255.El 1256.Sh CTL_VM 1257The string and integer information available for the CTL_VM level 1258is detailed below. 1259The changeable column shows whether a process with appropriate 1260privilege may change the value. 1261.Bl -column "Second level nameXXXXXX" "struct loadavgXXX" -offset indent 1262.It Sy Pa Second level name Type Changeable 1263.It VM\_LOADAVG struct loadavg no 1264.It VM\_METER struct vmtotal no 1265.El 1266.Pp 1267.Bl -tag -width "123456" 1268.It Li VM_LOADAVG 1269Return the load average history. 1270The returned data consists of a 1271.Va struct loadavg . 1272.It Li VM_METER 1273Return the system wide virtual memory statistics. 1274The returned data consists of a 1275.Va struct vmtotal . 1276.El 1277.Sh CTL_DDB 1278The integer information available for the CTL_DDB level is detailed below. 1279The changeable column shows whether a process with appropriate 1280privilege may change the value. 1281.Bl -column "DBCTL_TABSTOPSXXX" "integerXXX" -offset indent 1282.It Sy Pa Second level name Type Changeable 1283.It DBCTL\_RADIX integer yes 1284.It DBCTL\_MAXOFF integer yes 1285.It DBCTL\_LINES integer yes 1286.It DBCTL\_TABSTOPS integer yes 1287.It DBCTL\_ONPANIC integer yes 1288.It DBCTL\_FROMCONSOLE integer yes 1289.El 1290.Pp 1291.Bl -tag -width "123456" 1292.It Li DBCTL_RADIX 1293The input and output radix. 1294.It Li DBCTL_MAXOFF 1295The maximum symbol offset. 1296.It Li DBCTL_LINES 1297Number of display lines. 1298.It Li DBCTL_TABSTOPS 1299Tab width. 1300.It Li DBCTL_ONPANIC 1301If non-zero, DDB will be entered when the kernel panics. 1302.It Li DBCTL_FROMCONSOLE 1303If not zero, DDB may be entered by sending a break on a serial 1304console or by a special key sequence on a graphics console. 1305.El 1306.Pp 1307These MIB nodes are also available as variables from within the 1308DDB. See 1309.Xr ddb 4 1310for more details. 1311.Sh RETURN VALUES 1312If the call to 1313.Nm 1314is successful, the number of bytes copied out is returned. 1315Otherwise \-1 is returned and 1316.Va errno 1317is set appropriately. 1318.Sh ERRORS 1319The following errors may be reported: 1320.Bl -tag -width Er 1321.It Bq Er EFAULT 1322The buffer 1323.Fa name , 1324.Fa oldp , 1325.Fa newp , 1326or length pointer 1327.Fa oldlenp 1328contains an invalid address. 1329.It Bq Er EINVAL 1330The 1331.Fa name 1332array is less than two or greater than CTL_MAXNAME. 1333.It Bq Er EINVAL 1334A non-null 1335.Fa newp 1336is given and its specified length in 1337.Fa newlen 1338is too large or too small. 1339.It Bq Er ENOMEM 1340The length pointed to by 1341.Fa oldlenp 1342is too short to hold the requested value. 1343.It Bq Er ENOTDIR 1344The 1345.Fa name 1346array specifies an intermediate rather than terminal name. 1347.It Bq Er EOPNOTSUPP 1348The 1349.Fa name 1350array specifies a value that is unknown. 1351.It Bq Er EPERM 1352An attempt is made to set a read-only value. 1353.It Bq Er EPERM 1354A process without appropriate privilege attempts to set a value. 1355.It Bq Er EPERM 1356An attempt to change a value protected by the current kernel security 1357level is made. 1358.El 1359.Sh FILES 1360.Bl -tag -width <netinet6/udp6Xvar.h> -compact 1361.It Pa <sys/sysctl.h> 1362definitions for top level identifiers, second level kernel and hardware 1363identifiers, and user level identifiers 1364.It Pa <sys/socket.h> 1365definitions for second level network identifiers 1366.It Pa <sys/gmon.h> 1367definitions for third level profiling identifiers 1368.It Pa <uvm/uvm_param.h> 1369definitions for second level virtual memory identifiers 1370.It Pa <netinet/in.h> 1371definitions for third level IPv4/v6 identifiers and 1372fourth level IPv4/v6 identifiers 1373.It Pa <netinet/icmp_var.h> 1374definitions for fourth level ICMP identifiers 1375.It Pa <netinet/icmp6.h> 1376definitions for fourth level ICMPv6 identifiers 1377.It Pa <netinet/tcp_var.h> 1378definitions for fourth level TCP identifiers 1379.It Pa <netinet/udp_var.h> 1380definitions for fourth level UDP identifiers 1381.It Pa <netinet6/udp6_var.h> 1382definitions for fourth level IPv6 UDP identifiers 1383.It Pa <netinet6/ipsec.h> 1384definitions for fourth level IPsec identifiers 1385.El 1386.Sh SEE ALSO 1387.Xr ipsec 4 , 1388.Xr sysctl 8 1389.Sh HISTORY 1390The 1391.Nm 1392function first appeared in 1393.Bx 4.4 . 1394