1.\" $NetBSD: sysctl.3,v 1.70 2000/10/26 07:24:00 jdolecek 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 udp6 sendspace integer yes 902.It udp6 recvspace integer yes 903.El 904.Pp 905The variables are as follows: 906.Bl -tag -width "123456" 907.It Li ip6.forwarding 908Returns 1 when IPv6 forwarding is enabled for the node, 909meaning that the node is acting as a router. 910Returns 0 when IPv6 forwarding is disabled for the node, 911meaning that the node is acting as a host. 912IPv6 specification defines node behavior for 913.Dq router 914case and 915.Dq host 916case quite differently, and changing this variable during operation 917may cause serious trouble. 918It is recommended to configure the variable at bootstrap time, 919and bootstrap time only. 920.It Li ip6.redirect 921Returns 1 when ICMPv6 redirects may be sent by the node. 922This option is ignored unless the node is routing IP packets, 923and should normally be enabled on all systems. 924.It Li ip6.hlim 925The default hop limit value for an IPv6 unicast packet sourced by the node. 926This value applies to all the transport protocols on top of IPv6. 927There are APIs to override the value, as documented in 928.Xr ip6 4 . 929.It Li ip6.maxfragpackets 930The maximum number of fragmented packets the node will accept. 9310 means that the node will not accept any fragmented packets. 932-1 means that the node will accept as many fragmented packets as it receives. 933The flag is provided basically for avoiding possible DoS attacks. 934.It Li ip6.accept_rtadv 935If set to non-zero, the node will accept ICMPv6 router advertisement packets 936and autoconfigures address prefixes and default routers. 937The node must be a host 938.Pq not a router 939for the option to be meaningful. 940.It Li ip6.keepfaith 941If set to non-zero, it enables 942.Dq FAITH 943TCP relay IPv6-to-IPv4 translator code in the kernel. 944Refer 945.Xr faith 4 946and 947.Xr faithd 8 948for detail. 949.It Li ip6.log_interval 950The variable controls amount of logs generated by IPv6 packet 951forwarding engine, by seting interval between log output 952.Pq in seconds . 953.It Li ip6.hdrnestlimit 954The number of IPv6 extension headers permitted on incoming IPv6 packets. 955If set to 0, the node will accept as many extension headers as possible. 956.It Li ip6.dad_count 957The variable cofigures number of IPv6 DAD 958.Pq duplicated address detection 959probe packets. 960The packets will be generated when IPv6 interface addresses are configured. 961.It Li ip6.auto_flowlabel 962On connected transport protocol packets, 963fill IPv6 flowlabel field to help intermediate routers to identify packet flows. 964.It Li ip6.defmcasthlim 965The default hop limit value for an IPv6 multicast packet sourced by the node. 966This value applies to all the transport protocols on top of IPv6. 967There are APIs to override the value, as documented in 968.Xr ip6 4 . 969.It Li ip6.gif_hlim 970The maximum hop limit value for an IPv6 packet generated by 971.Xr gif 4 972tunnel interface. 973.It Li ip6.kame_version 974The string identifies the version of KAME IPv6 stack implemented in the kernel. 975.It Li ip6.use_deprecated 976The variable controls use of deprecated address, specified in RFC2462 5.5.4. 977.It Li ip6.rr_prune 978The variable specifies interval between IPv6 router renumbering prefix 979babysitting, in seconds. 980.It Li ip6.bindv6only 981The variable specifies initial value for 982.Dv IPV6_BINDV6ONLY 983socket option for 984.Dv AF_INET6 985socket. 986Please refer to 987.Xr ip6 4 988for detail. 989.It Li ip6.anonportmin 990The lowest port number to use for TCP and UDP ephemeral port allocation. 991This cannot be set to less than 1024 or greater than 65535. 992.It Li ip6.anonportmax 993The highest port number to use for TCP and UDP ephemeral port allocation. 994This cannot be set to less than 1024 or greater than 65535, and must 995be greater than 996.Li ip6.anonportmin . 997.It Li ip6.lowportmin 998The lowest port number to use for TCP and UDP reserved port allocation. 999This cannot be set to less than 0 or greater than 1024, and must 1000be smaller than 1001.Li ip6.lowportmax . 1002.It Li ip6.lowportmax 1003The highest port number to use for TCP and UDP reserved port allocation. 1004This cannot be set to less than 0 or greater than 1024, and must 1005be greater than 1006.Li ip6.lowportmin . 1007.It Li icmp6.rediraccept 1008If set to non-zero, the host will accept ICMPv6 redirect packets. 1009Note that IPv6 routers will never accept ICMPv6 redirect packets, 1010and the variable is meaningful on IPv6 hosts 1011.Pq non-router 1012only. 1013.It Li icmp6.redirtimeout 1014The variable specifies lifetime of routing entries generated by incoming 1015ICMPv6 redirect. 1016.It Li icmp6.nd6_prune 1017The variable specifies interval between IPv6 neighbor cache babysitting, 1018in seconds. 1019.It Li icmp6.nd6_delay 1020The variable specifies 1021.Dv DELAY_FIRST_PROBE_TIME 1022timing constant in IPv6 neighbor discovery specification 1023.Pq RFC2461 , 1024in seconds. 1025.It Li icmp6.nd6_umaxtries 1026The variable specifies 1027.Dv MAX_UNICAST_SOLICIT 1028constant in IPv6 neighbor discovery specification 1029.Pq RFC2461 . 1030.It Li icmp6.nd6_mmaxtries 1031The variable specifies 1032.Dv MAX_MULTICAST_SOLICIT 1033constant in IPv6 neighbor discovery specification 1034.Pq RFC2461 . 1035.It Li icmp6.nd6_useloopback 1036If set to non-zero, kernel IPv6 stack will use loopback interface for 1037local traffic. 1038.It Li icmp6.nodeinfo 1039The variable enables, or disables, kernel support for 1040ICMPv6 node information query/reply. 1041.It Li icmp6.errppslimit 1042The variable specifies the maximum number of outgoing ICMPv6 error messages, 1043per second. 1044ICMPv6 error messages that exceeded the value are subject to rate limitation 1045and will not go out from the node. 1046Negative value disables rate limitation. 1047.It Li icmp6.nd6_maxnudhint 1048IPv6 neighbor discovery permits upper layer protocols to supply reachability 1049hints, to avoid unnecessary neighbor discovery exchanges. 1050The variable defines the number of consecutive hints the neighbor discovery 1051layer will take. 1052For example, by setting the variable to 3, neighbor discovery layer 1053will take 3 consecutive hints in maximum. 1054After receiving 3 hints, neighbor discovery layer will perform 1055normal neighbor discovery process. 1056.El 1057.Pp 1058We reuse net.*.tcp for 1059.Tn TCP 1060over 1061.Tn IPv6 , 1062and therefore we do not have variables net.*.tcp6. 1063Variables net.inet6.udp6 have identical meaning to net.inet.udp. 1064Please refer to 1065.Li PF_INET 1066section above. 1067For variables net.*.ipsec6, please refer to 1068.Xr ipsec 4 . 1069.El 1070.Sh CTL_PROC 1071The string and integer information available for the CTL_PROC 1072is detailed below. 1073The changeable column shows whether a process with appropriate 1074privilege may change the value. 1075These values are per-process, and as such may change from one process 1076to another. When a process is created, the default values are inherited from 1077its parent. When a set-user-ID or set-group-ID binary is executed, the 1078value of PROC_PID_CORENAME is reset to the system default value. 1079The second level name is either the magic value PROC_CURPROC, which 1080points to the current process, or the PID of the target process. 1081.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" "yes" -offset indent 1082.It Sy Pa Third level name Type Changeable 1083.It PROC\_PID\_CORENAME string yes 1084.It PROC\_PID\_LIMIT node not applicable 1085.El 1086.Bl -tag -width "123456" 1087.Pp 1088.It Li PROC_PID_CORENAME 1089The template used for the core dump file name (see 1090.Xr core 5 1091for details). The base name must either be 1092.Nm core 1093or end with the suffix ``.core'' (the super-user may set arbitrary names). By 1094default it points to KERN_DEFCORENAME. 1095.It Li PROC_PID_LIMIT 1096Return resources limits, as defined for the 1097.Xr getrlimit 2 1098and 1099.Xr setrlimit 2 1100system calls. 1101The fourth level name is one of: 1102.Bl -tag -width PROC_PID_LIMIT_MEMLOCKAA 1103.It Li PROC_PID_LIMIT_CPU 1104The maximum amount of cpu time (in seconds) to be used by each process. 1105.It Li PROC_PID_LIMIT_FSIZE 1106The largest size (in bytes) file that may be created. 1107.It Li PROC_PID_LIMIT_DATA 1108The maximum size (in bytes) of the data segment for a process; 1109this defines how far a program may extend its break with the 1110.Xr sbrk 2 1111system call. 1112.It Li PROC_PID_LIMIT_STACK 1113The maximum size (in bytes) of the stack segment for a process; 1114this defines how far a program's stack segment may be extended. 1115Stack extension is performed automatically by the system. 1116.It Li PROC_PID_LIMIT_CORE 1117The largest size (in bytes) 1118.Pa core 1119file that may be created. 1120.It Li PROC_PID_LIMIT_RSS 1121The maximum size (in bytes) to which a process's resident set size may 1122grow. 1123This imposes a limit on the amount of physical memory to be given to 1124a process; if memory is tight, the system will prefer to take memory 1125from processes that are exceeding their declared resident set size. 1126.It Li PROC_PID_LIMIT_MEMLOCK 1127The maximum size (in bytes) which a process may lock into memory 1128using the 1129.Xr mlock 2 1130function. 1131.It Li PROC_PID_LIMIT_NPROC 1132The maximum number of simultaneous processes for this user id. 1133.It Li PROC_PID_LIMIT_NOFILE 1134The maximum number of open files for this process. 1135.El 1136.Pp 1137The fifth level name is one of PROC_PID_LIMIT_TYPE_SOFT or 1138PROC_PID_LIMIT_TYPE_HARD, to select respectively the soft or hard limit. 1139Both are of type integer. 1140.El 1141.Pp 1142 1143.Sh CTL_USER 1144The string and integer information available for the CTL_USER level 1145is detailed below. 1146The changeable column shows whether a process with appropriate 1147privilege may change the value. 1148.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" -offset indent 1149.It Sy Pa Second level name Type Changeable 1150.It USER\_BC\_BASE\_MAX integer no 1151.It USER\_BC\_DIM\_MAX integer no 1152.It USER\_BC\_SCALE\_MAX integer no 1153.It USER\_BC\_STRING\_MAX integer no 1154.It USER\_COLL\_WEIGHTS\_MAX integer no 1155.It USER\_CS\_PATH string no 1156.It USER\_EXPR\_NEST\_MAX integer no 1157.It USER\_LINE\_MAX integer no 1158.It USER\_POSIX2\_CHAR\_TERM integer no 1159.It USER\_POSIX2\_C\_BIND integer no 1160.It USER\_POSIX2\_C\_DEV integer no 1161.It USER\_POSIX2\_FORT\_DEV integer no 1162.It USER\_POSIX2\_FORT\_RUN integer no 1163.It USER\_POSIX2\_LOCALEDEF integer no 1164.It USER\_POSIX2\_SW\_DEV integer no 1165.It USER\_POSIX2\_UPE integer no 1166.It USER\_POSIX2\_VERSION integer no 1167.It USER\_RE\_DUP\_MAX integer no 1168.It USER\_STREAM\_MAX integer no 1169.It USER\_TZNAME\_MAX integer no 1170.El 1171.Bl -tag -width "123456" 1172.Pp 1173.It Li USER_BC_BASE_MAX 1174The maximum ibase/obase values in the 1175.Xr bc 1 1176utility. 1177.It Li USER_BC_DIM_MAX 1178The maximum array size in the 1179.Xr bc 1 1180utility. 1181.It Li USER_BC_SCALE_MAX 1182The maximum scale value in the 1183.Xr bc 1 1184utility. 1185.It Li USER_BC_STRING_MAX 1186The maximum string length in the 1187.Xr bc 1 1188utility. 1189.It Li USER_COLL_WEIGHTS_MAX 1190The maximum number of weights that can be assigned to any entry of 1191the LC_COLLATE order keyword in the locale definition file. 1192.It Li USER_CS_PATH 1193Return a value for the 1194.Ev PATH 1195environment variable that finds all the standard utilities. 1196.It Li USER_EXPR_NEST_MAX 1197The maximum number of expressions that can be nested within 1198parenthesis by the 1199.Xr expr 1 1200utility. 1201.It Li USER_LINE_MAX 1202The maximum length in bytes of a text-processing utility's input 1203line. 1204.It Li USER_POSIX2_CHAR_TERM 1205Return 1 if the system supports at least one terminal type capable of 1206all operations described in POSIX 1003.2, otherwise 0. 1207.It Li USER_POSIX2_C_BIND 1208Return 1 if the system's C-language development facilities support the 1209C-Language Bindings Option, otherwise 0. 1210.It Li USER_POSIX2_C_DEV 1211Return 1 if the system supports the C-Language Development Utilities Option, 1212otherwise 0. 1213.It Li USER_POSIX2_FORT_DEV 1214Return 1 if the system supports the FORTRAN Development Utilities Option, 1215otherwise 0. 1216.It Li USER_POSIX2_FORT_RUN 1217Return 1 if the system supports the FORTRAN Runtime Utilities Option, 1218otherwise 0. 1219.It Li USER_POSIX2_LOCALEDEF 1220Return 1 if the system supports the creation of locales, otherwise 0. 1221.It Li USER_POSIX2_SW_DEV 1222Return 1 if the system supports the Software Development Utilities Option, 1223otherwise 0. 1224.It Li USER_POSIX2_UPE 1225Return 1 if the system supports the User Portability Utilities Option, 1226otherwise 0. 1227.It Li USER_POSIX2_VERSION 1228The version of POSIX 1003.2 with which the system attempts to comply. 1229.It Li USER_RE_DUP_MAX 1230The maximum number of repeated occurrences of a regular expression 1231permitted when using interval notation. 1232.ne 1i 1233.It Li USER_STREAM_MAX 1234The minimum maximum number of streams that a process may have open 1235at any one time. 1236.It Li USER_TZNAME_MAX 1237The minimum maximum number of types supported for the name of a 1238timezone. 1239.El 1240.Sh CTL_VM 1241The string and integer information available for the CTL_VM level 1242is detailed below. 1243The changeable column shows whether a process with appropriate 1244privilege may change the value. 1245.Bl -column "Second level nameXXXXXX" "struct loadavgXXX" -offset indent 1246.It Sy Pa Second level name Type Changeable 1247.It VM\_LOADAVG struct loadavg no 1248.It VM\_METER struct vmtotal no 1249.El 1250.Pp 1251.Bl -tag -width "123456" 1252.It Li VM_LOADAVG 1253Return the load average history. 1254The returned data consists of a 1255.Va struct loadavg . 1256.It Li VM_METER 1257Return the system wide virtual memory statistics. 1258The returned data consists of a 1259.Va struct vmtotal . 1260.El 1261.Sh CTL_DDB 1262The integer information available for the CTL_DDB level is detailed below. 1263The changeable column shows whether a process with appropriate 1264privilege may change the value. 1265.Bl -column "DBCTL_TABSTOPSXXX" "integerXXX" -offset indent 1266.It Sy Pa Second level name Type Changeable 1267.It DBCTL\_RADIX integer yes 1268.It DBCTL\_MAXOFF integer yes 1269.It DBCTL\_LINES integer yes 1270.It DBCTL\_TABSTOPS integer yes 1271.It DBCTL\_ONPANIC integer yes 1272.It DBCTL\_FROMCONSOLE integer yes 1273.El 1274.Pp 1275.Bl -tag -width "123456" 1276.It Li DBCTL_RADIX 1277The input and output radix. 1278.It Li DBCTL_MAXOFF 1279The maximum symbol offset. 1280.It Li DBCTL_LINES 1281Number of display lines. 1282.It Li DBCTL_TABSTOPS 1283Tab width. 1284.It Li DBCTL_ONPANIC 1285If non-zero, DDB will be entered when the kernel panics. 1286.It Li DBCTL_FROMCONSOLE 1287If not zero, DDB may be entered by sending a break on a serial 1288console or by a special key sequence on a graphics console. 1289.El 1290.Pp 1291These MIB nodes are also available as variables from within the 1292DDB. See 1293.Xr ddb 4 1294for more details. 1295.Sh RETURN VALUES 1296If the call to 1297.Nm 1298is successful, the number of bytes copied out is returned. 1299Otherwise \-1 is returned and 1300.Va errno 1301is set appropriately. 1302.Sh ERRORS 1303The following errors may be reported: 1304.Bl -tag -width Er 1305.It Bq Er EFAULT 1306The buffer 1307.Fa name , 1308.Fa oldp , 1309.Fa newp , 1310or length pointer 1311.Fa oldlenp 1312contains an invalid address. 1313.It Bq Er EINVAL 1314The 1315.Fa name 1316array is less than two or greater than CTL_MAXNAME. 1317.It Bq Er EINVAL 1318A non-null 1319.Fa newp 1320is given and its specified length in 1321.Fa newlen 1322is too large or too small. 1323.It Bq Er ENOMEM 1324The length pointed to by 1325.Fa oldlenp 1326is too short to hold the requested value. 1327.It Bq Er ENOTDIR 1328The 1329.Fa name 1330array specifies an intermediate rather than terminal name. 1331.It Bq Er EOPNOTSUPP 1332The 1333.Fa name 1334array specifies a value that is unknown. 1335.It Bq Er EPERM 1336An attempt is made to set a read-only value. 1337.It Bq Er EPERM 1338A process without appropriate privilege attempts to set a value. 1339.It Bq Er EPERM 1340An attempt to change a value protected by the current kernel security 1341level is made. 1342.El 1343.Sh FILES 1344.Bl -tag -width <netinet6/udp6Xvar.h> -compact 1345.It Pa <sys/sysctl.h> 1346definitions for top level identifiers, second level kernel and hardware 1347identifiers, and user level identifiers 1348.It Pa <sys/socket.h> 1349definitions for second level network identifiers 1350.It Pa <sys/gmon.h> 1351definitions for third level profiling identifiers 1352.It Pa <uvm/uvm_param.h> 1353definitions for second level virtual memory identifiers 1354.It Pa <netinet/in.h> 1355definitions for third level IPv4/v6 identifiers and 1356fourth level IPv4/v6 identifiers 1357.It Pa <netinet/icmp_var.h> 1358definitions for fourth level ICMP identifiers 1359.It Pa <netinet/icmp6.h> 1360definitions for fourth level ICMPv6 identifiers 1361.It Pa <netinet/tcp_var.h> 1362definitions for fourth level TCP identifiers 1363.It Pa <netinet/udp_var.h> 1364definitions for fourth level UDP identifiers 1365.It Pa <netinet6/udp6_var.h> 1366definitions for fourth level IPv6 UDP identifiers 1367.It Pa <netinet6/ipsec.h> 1368definitions for fourth level IPsec identifiers 1369.El 1370.Sh SEE ALSO 1371.Xr ipsec 4 , 1372.Xr sysctl 8 1373.Sh HISTORY 1374The 1375.Nm 1376function first appeared in 1377.Bx 4.4 . 1378