1.\" $NetBSD: sysctl.3,v 1.93 2002/05/19 08:12:55 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 \*[Lt]sys/param.h\*[Gt] 46.Fd #include \*[Lt]sys/sysctl.h\*[Gt] 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 Aq 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\_KERN sys/sysctl.h High kernel limits 125.It CTL\_VM uvm/uvm_param.h Virtual memory 126.It CTL\_VFS sys/mount.h Filesystem 127.It CTL\_NET sys/socket.h Networking 128.It CTL\_DEBUG sys/sysctl.h Debugging 129.It CTL\_HW sys/sysctl.h Generic CPU, I/O 130.It CTL\_MACHDEP sys/sysctl.h Machine dependent 131.It CTL\_USER sys/sysctl.h User-level 132.It CTL\_DDB sys/sysctl.h In-kernel debugger 133.It CTL\_PROC sys/sysctl.h Per-process 134.It CTL\_VENDOR ? Vendor specific 135.El 136.Pp 137For example, the following retrieves the maximum number of processes allowed 138in the system: 139.Bd -literal -offset indent -compact 140int mib[2], maxproc; 141size_t len; 142.sp 143mib[0] = CTL_KERN; 144mib[1] = KERN_MAXPROC; 145len = sizeof(maxproc); 146sysctl(mib, 2, \*[Am]maxproc, \*[Am]len, NULL, 0); 147.Ed 148.sp 149To retrieve the standard search path for the system utilities: 150.Bd -literal -offset indent -compact 151int mib[2]; 152size_t len; 153char *p; 154.sp 155mib[0] = CTL_USER; 156mib[1] = USER_CS_PATH; 157sysctl(mib, 2, NULL, \*[Am]len, NULL, 0); 158p = malloc(len); 159sysctl(mib, 2, p, \*[Am]len, NULL, 0); 160.Ed 161.Sh CTL_DEBUG 162The debugging variables vary from system to system. 163A debugging variable may be added or deleted without need to recompile 164.Nm 165to know about it. 166Each time it runs, 167.Nm 168gets the list of debugging variables from the kernel and 169displays their current values. 170The system defines twenty 171.Ns ( Va struct ctldebug ) 172variables named 173.Dv debug0 174through 175.Dv debug19 . 176They are declared as separate variables so that they can be 177individually initialized at the location of their associated variable. 178The loader prevents multiple use of the same variable by issuing errors 179if a variable is initialized in more than one place. 180For example, to export the variable 181.Dv dospecialcheck 182as a debugging variable, the following declaration would be used: 183.Bd -literal -offset indent -compact 184int dospecialcheck = 1; 185struct ctldebug debug5 = { "dospecialcheck", \*[Am]dospecialcheck }; 186.Ed 187.Sh CTL_VFS 188A distinguished second level name, VFS_GENERIC, 189is used to get general information about all filesystems. 190One of its third level identifiers is VFS_MAXTYPENUM 191that gives the highest valid filesystem type number. 192Its other third level identifier is VFS_CONF that 193returns configuration information about the filesystem 194type given as a fourth level identifier. 195The remaining second level identifiers are the 196filesystem type number returned by a 197.Xr statfs 2 198call or from VFS_CONF. 199The third level identifiers available for each filesystem 200are given in the header file that defines the mount 201argument structure for that filesystem. 202.Sh CTL_HW 203The string and integer information available for the CTL_HW level 204is detailed below. 205The changeable column shows whether a process with appropriate 206privilege may change the value. 207.Bl -column "Second level nameXXXXXX" "struct disk_sysctlXXX" -offset indent 208.It Sy Pa Second level name Type Changeable 209.It HW\_MACHINE string no 210.It HW\_MODEL string no 211.It HW\_NCPU integer no 212.It HW\_BYTEORDER integer no 213.It HW\_PHYSMEM integer no 214.It HW\_USERMEM integer no 215.It HW\_PAGESIZE integer no 216.\".It HW\_DISKNAMES struct no 217.\".It HW\_DISKSTATS struct no 218.It HW\_MACHINE\_ARCH string no 219.It HW\_ALIGNBYTES integer no 220.It HW\_DISKNAMES string no 221.It HW\_DISKSTATS struct disk_sysctl no 222.El 223.Pp 224.Bl -tag -width "123456" 225.It Li HW_MACHINE 226The machine class. 227.It Li HW_MODEL 228The machine model 229.It Li HW_NCPU 230The number of cpus. 231.ne 1i 232.It Li HW_BYTEORDER 233The byteorder (4,321, or 1,234). 234.It Li HW_PHYSMEM 235The bytes of physical memory. 236.It Li HW_USERMEM 237The bytes of non-kernel memory. 238.It Li HW_PAGESIZE 239The software page size. 240.It Li HW_DISKNAMES 241The list of (space separated) disk device names on the system. 242.It Li HW_DISKSTATS 243Return statistical information on the disk devices on the system. 244An array of 245.Va struct disk_sysctl 246structures is returned, 247whose size depends on the current number of such objects in the system. 248The third level name is the size of the 249.Va struct disk_sysctl . 250.It Li HW_MACHINE_ARCH 251The machine cpu class. 252.It Li HW_ALIGNBYTES 253Alignment constraint for all possible data types. 254This shows the value 255.Dv ALIGNBYTES 256in 257.Pa /usr/include/machine/param.h , 258at the kernel compilation time. 259.El 260.Sh CTL_KERN 261The string and integer information available for the CTL_KERN level 262is detailed below. 263The changeable column shows whether a process with appropriate 264privilege may change the value. 265The types of data currently available are process information, 266system vnodes, the open file entries, routing table entries, 267virtual memory statistics, load average history, and clock rate 268information. 269.Bl -column "KERNXCHOWNXRESTRICTEDXXX" "struct clockrateXXX" -offset indent 270.It Sy Pa Second level name Type Changeable 271.It KERN\_ARGMAX integer no 272.It KERN\_AUTONICETIME integer yes 273.It KERN\_AUTONICEVAL integer yes 274.It KERN\_BOOTTIME struct timeval no 275.It KERN\_CCPU integer no 276.It KERN\_CLOCKRATE struct clockinfo no 277.It KERN\_CP\_TIME long[\|] no 278.It KERN\_DEFCORENAME string yes 279.It KERN\_DOMAINNAME string yes 280.It KERN\_FILE struct file no 281.It KERN\_FSCALE integer no 282.It KERN\_FSYNC integer no 283.It KERN\_HOSTID integer yes 284.It KERN\_HOSTNAME string yes 285.It KERN\_IOV\_MAX integer no 286.It KERN\_JOB\_CONTROL integer no 287.It KERN\_LOGIN\_NAME\_MAX integer no 288.It KERN\_LOGSIGEXIT integer yes 289.It KERN\_MAPPED\_FILES integer no 290.It KERN\_MAXFILES integer yes 291.It KERN\_MAXPARTITIONS integer no 292.It KERN\_MAXPROC integer yes 293.It KERN\_MAXPTYS integer yes 294.It KERN\_MAXVNODES integer yes 295.It KERN\_MBUF node not applicable 296.It KERN\_MEMLOCK integer no 297.It KERN\_MEMLOCK\_RANGE integer no 298.It KERN\_MEMORY\_PROTECTION integer no 299.It KERN\_MONOTONIC\_CLOCK integer no 300.It KERN\_MSGBUF char[\|] no 301.It KERN\_MSGBUFSIZE integer no 302.It KERN\_NGROUPS integer no 303.It KERN\_NTPTIME struct ntptimeval no 304.It KERN\_OSRELEASE string no 305.It KERN\_OSREV integer no 306.It KERN\_OSTYPE string no 307.It KERN\_POSIX1 integer no 308.It KERN\_PROC struct kinfo_proc no 309.It KERN\_PROC2 struct kinfo_proc2 no 310.It KERN\_PROC\_ARGS string no 311.It KERN\_PROF node not applicable 312.It KERN\_RAWPARTITION integer no 313.It KERN\_ROOT\_DEVICE string no 314.It KERN\_RTC\_OFFSET integer no 315.It KERN\_SAVED\_IDS integer no 316.It KERN\_SECURELVL integer raise only 317.It KERN\_SYNCHRONIZED\_IO integer no 318.It KERN\_SYSVIPC\_INFO node not applicable 319.It KERN\_SYSVMSG integer no 320.It KERN\_SYSVSEM integer no 321.It KERN\_SYSVSHM integer no 322.It KERN\_TKSTAT node not applicable 323.It KERN\_VERSION string no 324.It KERN\_VNODE struct vnode no 325.El 326.ne 1i 327.Pp 328.Bl -tag -width "123456" 329.It Li KERN_ARGMAX 330The maximum bytes of argument to 331.Xr execve 2 . 332.It Li KERN_AUTONICETIME 333The number of seconds of cpu-time a non-root process may accumulate before 334having its priority lowered from the default to the value of KERN_AUTONICEVAL. 335If set to 0, automatic lowering of priority is not performed, and if set to -1 336all non-root processes are immediately lowered. 337.It Li KERN_AUTONICEVAL 338The priority assigned for automatically niced processes. 339.It Li KERN_BOOTTIME 340A 341.Va struct timeval 342structure is returned. 343This structure contains the time that the system was booted. 344.It Li KERN_CCPU 345The scheduler exponential decay value. 346.It Li KERN_CLOCKRATE 347A 348.Va struct clockinfo 349structure is returned. 350This structure contains the clock, statistics clock and profiling clock 351frequencies, the number of micro-seconds per hz tick, and the clock 352skew rate. 353.It Li KERN_CP_TIME 354Return an array if CPUSTATES longs is returned. This array contains the 355number of clock ticks spent in different CPU states. 356.It Li KERN_DEFCORENAME 357Default template for the name of core dump files (see also PROC_PID_CORENAME 358in the per-process variables CTL_PROC, and 359.Xr core 5 360for format of this template). The default value is 361.Nm %n.core 362and can be changed with the kernel configuration option 363.Cd options DEFCORENAME 364(see 365.Xr options 4 366). 367.It Li KERN_DOMAINNAME 368Get or set the YP domain name. 369.It Li KERN_FILE 370Return the entire file table. 371The returned data consists of a single 372.Va struct filehead 373followed by an array of 374.Va struct file , 375whose size depends on the current number of such objects in the system. 376.It Li KERN_FSCALE 377The kernel fixed-point scale factor. 378.It Li KERN_FSYNC 379Return 1 if the POSIX 1003.1b File Synchronization Option is available 380on this system, 381otherwise 0. 382.It Li KERN_HOSTID 383Get or set the host id. 384.It Li KERN_HOSTNAME 385Get or set the hostname. 386.It Li KERN_IOV_MAX 387Return the maximum number of 388.Va iovec 389structures that a process has available for use with 390.Xr preadv 2 , 391.Xr pwritev 2 , 392.Xr readv 2 , 393.Xr recvmsg 2 , 394.Xr sendmsg 2 395and 396.Xr writev 2 . 397.It Li KERN_JOB_CONTROL 398Return 1 if job control is available on this system, otherwise 0. 399.It Li KERN_LOGIN_NAME_MAX 400The size of the storage required for a login name, in bytes, 401including the terminating NUL. 402.It Li KERN_LOGSIGEXIT 403If this flag is non-zero, the kernel will 404.Xr log 9 405all process exits due to signals which create a 406.Xr core 5 407file, and whether the coredump was created. 408.It Li KERN_MAPPED_FILES 409Returns 1 if the POSIX 1003.1b Memory Mapped Files Option is available 410on this system, 411otherwise 0. 412.It Li KERN_MAXFILES 413The maximum number of open files that may be open in the system. 414.It Li KERN_MAXPARTITIONS 415The maximum number of partitions allowed per disk. 416.It Li KERN_MAXPROC 417The maximum number of simultaneous processes the system will allow. 418.It Li KERN_MAXPTYS 419The maximum number of pseudo terminals. This value can be both 420raised and lowered, though it cannot 421be set lower than number of currently used ptys. See also 422.Xr pty 4 . 423.It Li KERN_MAXVNODES 424The maximum number of vnodes available on the system. This can only 425be raised. 426.It Li KERN_MBUF 427Return information about the mbuf control variables. 428the third level names for the mbuf variables are detailed below. 429The changeable column shows whether a process with appropriate 430privilege may change the value. 431.Bl -column "MBUFXNMBCLUSTERSXXX" "struct integerXXX" -offset indent 432.It Sy Pa Third level name Type Changeable 433.It MBUF\_MSIZE integer yes 434.It MBUF\_MCLBYTES integer yes 435.It MBUF\_NMBCLUSTERS integer yes 436.It MBUF\_MBLOWAT integer yes 437.It MBUF\_MCLLOWAT integer yes 438.El 439.Pp 440The variables are as follows: 441.Bl -tag -width "123456" 442.It Li MBUF_MSIZE 443The mbuf base size. 444.It Li MBUF_MCLBYTES 445The mbuf cluster size. 446.It Li MBUF_NMBCLUSTERS 447The limit on the number of mbuf clusters. 448The variable can only be increased, and only increased on machines with 449direct-mapped pool pages 450.It Li MBUF_MBLOWAT 451The mbuf low water mark. 452.It Li MBUF_MCLLOWAT 453The mbuf cluster low water mark. 454.El 455.It Li KERN_MEMLOCK 456Returns 1 if the POSIX 1003.1b Process Memory Locking Option is available 457on this system, 458otherwise 0. 459.It Li KERN_MEMLOCK_RANGE 460Returns 1 if the POSIX 1003.1b Range Memory Locking Option is available 461on this system, 462otherwise 0. 463.It Li KERN_MEMORY_PROTECTION 464Returns 1 if the POSIX 1003.1b Memory Protection Option is available 465on this system, 466otherwise 0. 467.It Li KERN_MONOTONIC_CLOCK 468Returns the standard version the implementation of the POSIX 1003.1b 469Monotonic Clock Option conforms to, 470otherwise 0. 471.It Li KERN_MSGBUF 472The kernel message buffer, rotated so that the head of the circular kernel 473message buffer is returned at the start of the buffer specified by 474.Fa oldp . 475The returned data may contain NUL bytes. 476.It Li KERN_MSGBUFSIZE 477The maximum number of characters that the kernel message buffer can hold. 478.It Li KERN_NGROUPS 479The maximum number of supplemental groups. 480.It Li KERN_NO_TRUNC 481Return 1 if file names longer than KERN_NAME_MAX are truncated. 482.It Li KERN_NTPTIME 483A 484.Va struct ntptimeval 485structure is returned. 486This structure contains data used by the 487.Xr ntpd 8 488program. 489.It Li KERN_OSRELEASE 490The system release string. 491.It Li KERN_OSREV 492The system revision string. 493.It Li KERN_OSTYPE 494The system type string. 495.It Li KERN_PATH_MAX 496The maximum number of bytes in a pathname. 497.It Li KERN_POSIX1 498The version of ISO/IEC 9945 (POSIX 1003.1) with which the system 499attempts to comply. 500.It Li KERN_PROC 501Return the entire process table, or a subset of it. 502An array of 503.Va struct kinfo_proc 504structures is returned, 505whose size depends on the current number of such objects in the system. 506The third and fourth level names are as follows: 507.Bl -column "Third level nameXXXXXX" "Fourth level is:XXXXXX" -offset indent 508.It Pa Third level name Fourth level is: 509.It KERN\_PROC\_ALL None 510.It KERN\_PROC\_PID A process ID 511.It KERN\_PROC\_PGRP A process group 512.It KERN\_PROC\_SESSION A session ID 513.It KERN\_PROC\_TTY A tty device 514.It KERN\_PROC\_UID A user ID 515.It KERN\_PROC\_RUID A real user ID 516.It KERN\_PROC\_GID A group ID 517.It KERN\_PROC\_RGID A real group ID 518.El 519.It Li KERN_PROC2 520As for KERN_PROC, but an array of 521.Va struct kinfo_proc2 522structures are returned. The fifth level name is the size of the 523.Va struct kinfo_proc2 524and the sixth level name is the number of structures to return. 525.It Li KERN_PROC_ARGS 526Return the argv or environment strings (or the number thereof) 527of a process. Multiple strings are returned separated by NUL 528characters. The third level name is the process ID. The fourth 529level name is as follows: 530.Bl -column "Third level nameXXXXXX" -offset indent 531.It KERN\_PROC\_ARGV The argv strings 532.It KERN\_PROC\_NARGV The number of argv strings 533.It KERN\_PROC\_ENV The environ strings 534.It KERN\_PROC\_NENV The number of environ strings 535.El 536.It Li KERN_PROF 537Return profiling information about the kernel. 538If the kernel is not compiled for profiling, 539attempts to retrieve any of the KERN_PROF values will 540fail with EOPNOTSUPP. 541The third level names for the string and integer profiling information 542is detailed below. 543The changeable column shows whether a process with appropriate 544privilege may change the value. 545.Bl -column "GPROFXGMONPARAMXXX" "struct gmonparamXXX" -offset indent 546.It Sy Pa Third level name Type Changeable 547.It GPROF\_STATE integer yes 548.It GPROF\_COUNT u_short[\|] yes 549.It GPROF\_FROMS u_short[\|] yes 550.It GPROF\_TOS struct tostruct yes 551.It GPROF\_GMONPARAM struct gmonparam no 552.El 553.Pp 554The variables are as follows: 555.Bl -tag -width "123456" 556.It Li GPROF_STATE 557Returns GMON_PROF_ON or GMON_PROF_OFF to show that profiling 558is running or stopped. 559.It Li GPROF_COUNT 560Array of statistical program counter counts. 561.It Li GPROF_FROMS 562Array indexed by program counter of call-from points. 563.It Li GPROF_TOS 564Array of 565.Va struct tostruct 566describing destination of calls and their counts. 567.It Li GPROF_GMONPARAM 568Structure giving the sizes of the above arrays. 569.El 570.It Li KERN_RAWPARTITION 571The raw partition of a disk (a == 0). 572.It Li KERN_ROOT_DEVICE 573The name of the root device. 574.It Li KERN_RTC_OFFSET 575Return the offset of real time clock from UTC in minutes. 576.It Li KERN_SAVED_IDS 577Returns 1 if saved set-group and saved set-user ID is available. 578.It Li KERN_SECURELVL 579The system security level. 580This level may be raised by processes with appropriate privilege. 581It may only be lowered by process 1. 582.It Li KERN_SYNCHRONIZED_IO 583Returns 1 if the POSIX 1003.1b Synchronized I/O Option is available 584on this system, 585otherwise 0. 586.It Li KERN_SYSVIPC_INFO 587Return System V style IPC configuration and run-time information. 588The third level name selects the System V style IPC facility. 589.Bl -column "KERN_SYSVIPC_MSG_INFOXXX" "struct shm_sysctl_infoXXX" -offset indent 590.It Sy Pa Third level name Type 591.It KERN\_SYSVIPC\_MSG\_INFO struct msg_sysctl_info 592.It KERN\_SYSVIPC\_SEM\_INFO struct sem_sysctl_info 593.It KERN\_SYSVIPC\_SHM\_INFO struct shm_sysctl_info 594.El 595.Pp 596.Bl -tag -width "123456" 597.It Li KERN_SYSVIPC_MSG_INFO 598Return information on the System V style message facility. The 599.Sy msg_sysctl_info 600structure is defined in 601.Aq Pa sys/msg.h . 602.It Li KERN_SYSVIPC_SEM_INFO 603Return information on the System V style semaphore facility. The 604.Sy sem_sysctl_info 605structure is defined in 606.Aq Pa sys/sem.h . 607.It Li KERN_SYSVIPC_SHM_INFO 608Return information on the System V style shared memory facility. The 609.Sy shm_sysctl_info 610structure is defined in 611.Aq Pa sys/shm.h . 612.El 613.It Li KERN_SYSVMSG 614Returns 1 if System V style message queue functionality is available 615on this system, 616otherwise 0. 617.It Li KERN_SYSVSEM 618Returns 1 if System V style semaphore functionality is available 619on this system, 620otherwise 0. 621.It Li KERN_SYSVSHM 622Returns 1 if System V style share memory functionality is available 623on this system, 624otherwise 0. 625.It Li KERN_TKSTAT 626Return information about the number of characters sent and received 627on ttys. The third level names for the tty statistic variables 628are detailed below. The changeable column shows whether a process 629with appropriate privilege may change the value. 630.Bl -column "KERNXTKSTATXRAWCCXXX" "struct integerXXX" -offset indent 631.It Sy Pa Third level name Type Changeable 632.It KERN\_TKSTAT\_NIN quad no 633.It KERN\_TKSTAT\_NOUT quad no 634.It KERN\_TKSTAT\_CANCC quad no 635.It KERN\_TKSTAT\_RAWCC quad no 636.El 637.Pp 638The variables are as follows: 639.Bl -tag -width "123456" 640.It Li KERN_TKSTAT_NIN 641The total number of input characters. 642.It Li KERN_TKSTAT_NOUT 643The total number of output characters. 644.It Li KERN_TKSTAT_CANCC 645The number of canonical input characters. 646.It Li KERN_TKSTAT_RAWCC 647The number of raw input characters. 648.El 649.It Li KERN_VERSION 650The system version string. 651.It Li KERN_VNODE 652Return the entire vnode table. 653Note, the vnode table is not necessarily a consistent snapshot of 654the system. 655The returned data consists of an array whose size depends on the 656current number of such objects in the system. 657Each element of the array contains the kernel address of a vnode 658.Va struct vnode * 659followed by the vnode itself 660.Va struct vnode . 661.El 662.Sh CTL_MACHDEP 663The set of variables defined is architecture dependent. 664Most architectures define at least the following variables. 665.Bl -column "CONSOLE_DEVICEXXX" "integerXXX" -offset indent 666.It Sy Pa Second level name Type Changeable 667.It Li CPU_CONSDEV dev_t no 668.El 669.Sh CTL_NET 670The string and integer information available for the CTL_NET level 671is detailed below. 672The changeable column shows whether a process with appropriate 673privilege may change the value. 674.Bl -column "Second level nameXXXXXX" "routing messagesXXX" -offset indent 675.It Sy Pa Second level name Type Changeable 676.It PF\_ROUTE routing messages no 677.It PF\_INET IPv4 values yes 678.It PF\_INET6 IPv6 values yes 679.It PF\_KEY IPsec key management values yes 680.El 681.Pp 682.Bl -tag -width "123456" 683.It Li PF_ROUTE 684Return the entire routing table or a subset of it. 685The data is returned as a sequence of routing messages (see 686.Xr route 4 687for the header file, format and meaning). 688The length of each message is contained in the message header. 689.Pp 690The third level name is a protocol number, which is currently always 0. 691The fourth level name is an address family, which may be set to 0 to 692select all address families. 693The fifth and sixth level names are as follows: 694.Bl -column "Fifth level nameXXXXXX" "Sixth level is:XXX" -offset indent 695.It Pa Fifth level name Sixth level is: 696.It NET\_RT\_FLAGS rtflags 697.It NET\_RT\_DUMP None 698.It NET\_RT\_IFLIST None 699.El 700.It Li PF_INET 701Get or set various global information about the IPv4 702.Pq Internet Protocol version 4 . 703The third level name is the protocol. 704The fourth level name is the variable name. 705The currently defined protocols and names are: 706.Bl -column "Protocol name" "Variable nameXX" "integer" "yes" -offset indent 707.It Pa Protocol name Variable name Type Changeable 708.It ip forwarding integer yes 709.It ip redirect integer yes 710.It ip ttl integer yes 711.It ip forwsrcrt integer yes 712.It ip directed-broadcast integer yes 713.It ip allowsrcrt integer yes 714.It ip subnetsarelocal integer yes 715.It ip mtudisc integer yes 716.It ip anonportmin integer yes 717.It ip anonportmax integer yes 718.It ip mtudisctimeout integer yes 719.It ip gifttl integer yes 720.It ip grettl integer yes 721.It ip lowportmin integer yes 722.It ip lowportmax integer yes 723.It ip maxfragpacket integer yes 724.It icmp maskrepl integer yes 725.It icmp errppslimit integer yes 726.It icmp rediraccept integer yes 727.It icmp redirtimeout integer yes 728.It tcp rfc1323 integer yes 729.It tcp sendspace integer yes 730.It tcp recvspace integer yes 731.It tcp mssdflt integer yes 732.It tcp syn_cache_limit integer yes 733.It tcp syn_bucket_limit integer yes 734.It tcp syn_cache_interval integer yes 735.It tcp init_win integer yes 736.It tcp mss_ifmtu integer yes 737.It tcp sack integer yes 738.It tcp win_scale integer yes 739.It tcp timestamps integer yes 740.It tcp compat_42 integer yes 741.It tcp cwm integer yes 742.It tcp cwm_burstsize integer yes 743.It tcp ack_on_push integer yes 744.It tcp keepidle integer yes 745.It tcp keepintvl integer yes 746.It tcp keepcnt integer yes 747.It tcp slowhz integer no 748.It tcp newreno integer yes 749.It tcp log_refused integer yes 750.It tcp rstppslimit integer yes 751.It udp checksum integer yes 752.It udp sendspace integer yes 753.It udp recvspace integer yes 754.El 755.Pp 756The variables are as follows: 757.Bl -tag -width "123456" 758.It Li ip.forwarding 759Returns 1 when IP forwarding is enabled for the host, 760meaning that the host is acting as a router. 761.It Li ip.redirect 762Returns 1 when ICMP redirects may be sent by the host. 763This option is ignored unless the host is routing IP packets, 764and should normally be enabled on all systems. 765.It Li ip.ttl 766The maximum time-to-live (hop count) value for an IP packet sourced by 767the system. 768This value applies to normal transport protocols, not to ICMP. 769.It Li ip.forwsrcrt 770Returns 1 when forwarding of source-routed packets is enabled for 771the host. This value may only be changed if the kernel security 772level is less than 1. 773.It Li ip.directed-broadcast 774Returns 1 if directed broadcast behavior is enabled for the host. 775.It Li ip.allowsrcrt 776Returns 1 if the host accepts source routed packets. 777.It Li ip.subnetsarelocal 778Returns 1 if subnets are to be considered local addresses. 779.It Li ip.mtudisc 780Returns 1 if Path MTU Discovery is enabled. 781.It Li ip.anonportmin 782The lowest port number to use for TCP and UDP ephemeral port allocation. 783This cannot be set to less than 1024 or greater than 65535. 784.It Li ip.anonportmax 785The highest port number to use for TCP and UDP ephemeral port allocation. 786This cannot be set to less than 1024 or greater than 65535, and must 787be greater than 788.Li ip.anonportmin . 789.It Li ip.mtudisctimeout 790Returns the number of seconds in which a route added by the Path MTU 791Discovery engine will time out. When the route times out, the Path 792MTU Discovery engine will attempt to probe a larger path MTU. 793.It Li ip.gifttl 794The maximum time-to-live (hop count) value for an IPv4 packet generated by 795.Xr gif 4 796tunnel interface. 797.It Li ip.grettl 798The maximum time-to-live (hop count) value for an IPv4 packet generated by 799.Xr gre 4 800tunnel interface. 801.It Li ip.lowportmin 802The lowest port number to use for TCP and UDP reserved port allocation. 803This cannot be set to less than 0 or greater than 1024, and must 804be smaller than 805.Li ip.lowportmax . 806.It Li ip.lowportmax 807The highest port number to use for TCP and UDP reserved port allocation. 808This cannot be set to less than 0 or greater than 1024, and must 809be greater than 810.Li ip.lowportmin . 811.It Li ip.maxfragpackets 812The maximum number of fragmented packets the node will accept. 8130 means that the node will not accept any fragmented packets. 814-1 means that the node will accept as many fragmented packets as it receives. 815The flag is provided basically for avoiding possible DoS attacks. 816.It Li icmp.maskrepl 817Returns 1 if ICMP network mask requests are to be answered. 818.It Li icmp.errppslimit 819The variable specifies the maximum number of outgoing ICMP error messages, 820per second. 821ICMP error messages that exceeded the value are subject to rate limitation 822and will not go out from the node. 823Negative value disables rate limitation. 824.It Li icmp.rediraccept 825If set to non-zero, the host will accept ICMP redirect packets. 826Note that routers will never accept ICMP redirect packets, 827and the variable is meaningful on IP hosts only. 828.It Li icmp.redirtimeout 829The variable specifies lifetime of routing entries generated by incoming 830ICMP redirect. This defaults to zero; if the system is not running 831a routing daemon like 832.Xr routed 8 833than this value can be set to remove the routes added by redirect. 834A reasonable value to use would be 600 seconds. 835.It Li tcp.rfc1323 836Returns 1 if RFC1323 extensions to TCP are enabled. 837.It Li tcp.sendspace 838Returns the default TCP send buffer size. 839.It Li tcp.recvspace 840Returns the default TCP receive buffer size. 841.It Li tcp.mssdflt 842Returns the default maximum segment size both advertsized to the peer 843and to use when the peer does not advertize a maximum segment size to 844us during connection setup. Do not change this value unless you really 845know what you are doing. 846.It Li tcp.syn_cache_limit 847Returns the maximum number of entries allowed in the TCP compressed state 848engine. 849.It Li tcp.syn_bucket_limit 850Returns the maximum number of entries allowed per hash bucket in the TCP 851compressed state engine. 852.It Li tcp.syn_cache_interval 853Returns the TCP compressed state engine's timer interval. 854.It Li tcp.init_win 855Returns a value indicating the TCP initial congestion window. If this 856value is 0, an auto-tuning algorithm designed to use an initial window 857of approximately 4K bytes is in use. Otherwise, this value indicates 858a fixed number of packets. 859.It Li tcp.mss_ifmtu 860Returns 1 if TCP calculates the outgoing maximum segment size based on 861the MTU of the appropriate interface. Otherwise, it is calculated based on 862the greater of the MTU of the interface, and the largest (non-loopback) 863interface MTU on the system. 864.It Li tcp.sack 865TCP Selective ACKnowledgement (RFC 2018) is not implemented in 866.Nx 867at this time. 868Changing this value will have no effect. 869.It Li tcp.win_scale 870If rfc1323 is enabled, a value of 1 indicates RFC1323 window scale options, 871for increasing the TCP window size, are enabled. 872.It Li tcp.timestamps 873If rfc1323 is enabled, a value of 1 indicates RFC1323 time stamp options, 874used for measuring TCP round trip times, are enabled. 875.It Li tcp.compat_42 876Returns 1 if work-arounds for bugs in the 4.2BSD TCP implementation are 877enabled. Use of this option is not recommended, although it may be 878required in order to communicate with extremely old TCP implementations. 879.It Li tcp.cwm 880Returns 1 if use of the Hughes/Touch/Heidemann Congestion Window Monitoring 881algorithm is enabled. This algorithm prevents line-rate bursts of packets 882that could otherwise occur when data begins flowing on an idle TCP 883connection. These line-rate bursts can contribute to network and router 884congestion. This can be particularly useful on World Wide Web servers 885which support HTTP/1.1, which has lingering connections. 886.It Li tcp.cwm_burstsize 887Returns the Congestion Window Monitoring allowed burst size, in terms 888of packet count. 889.It Li tcp.ack_on_push 890Returns 1 if TCP is to immediately transmit an ACK upon reception of 891a packet with PUSH set. This can avoid losing a round trip time in some 892rare situations, but has the caveat of potentially defeating TCP's delayed 893ACK algorithm. Use of this option is generally not recommended, but 894the variable exists in case your configuration really needs it. 895.It Li tcp.keepidle 896Time a connection must be idle before keepalives are sent (if keepalives 897are enabled for the connection). See also tcp.slowhz. 898.It Li tcp.keepintvl 899Time after a keepalive probe is sent until, in the absence of any response, 900another probe is sent. See also tcp.slowhz. 901.It Li tcp.keepcnt 902Number of keepalive probes sent before declaring a connection dead. If 903set to zero, there is no limit; keepalives will be sent until some kind of 904response is received from the peer. 905.It Li tcp.slowhz 906The units for tcp.keepidle and tcp.keepintvl; those variables are in ticks 907of a clock that ticks tcp.slowhz times per second. (That is, their values 908must be divided by the tcp.slowhz value to get times in seconds.) 909.It Li tcp.newreno 910Returns 1 if the use of J. Hoe's NewReno congestion control algorithm is 911enabled. This algorithm improves the start-up behavior of TCP connections. 912.It Li tcp.log_refused 913Returns 1 if refused TCP connections to the host will be logged. 914.It Li tcp.rstppslimit 915The variable specifies the maximum number of outgoing TCP RST packets, 916per second. 917TCP RST packet that exceeded the value are subject to rate limitation 918and will not go out from the node. 919Negative value disables rate limitation. 920.It Li udp.checksum 921Returns 1 when UDP checksums are being computed and checked. 922Disabling UDP checksums is strongly discouraged. 923.It Li udp.sendspace 924Returns the default UDP send buffer size. 925.It Li udp.recvspace 926Returns the default UDP receive buffer size. 927.El 928.Pp 929For variables net.*.ipsec, please refer to 930.Xr ipsec 4 . 931.It Li PF_INET6 932Get or set various global information about the IPv6 933.Pq Internet Protocol version 6 . 934The third level name is the protocol. 935The fourth level name is the variable name. 936The currently defined protocols and names are: 937.Bl -column "Protocol name" "Variable nameXX" "integer" "yes" -offset indent 938.It Pa Protocol name Variable name Type Changeable 939.It ip6 forwarding integer yes 940.It ip6 redirect integer yes 941.It ip6 hlim integer yes 942.It ip6 maxfragpackets integer yes 943.It ip6 accept_rtadv integer yes 944.It ip6 keepfaith integer yes 945.It ip6 log_interval integer yes 946.It ip6 hdrnestlimit integer yes 947.It ip6 dad_count integer yes 948.It ip6 auto_flowlabel integer yes 949.It ip6 defmcasthlim integer yes 950.It ip6 gif_hlim integer yes 951.It ip6 kame_version string no 952.It ip6 use_deprecated integer yes 953.It ip6 rr_prune integer yes 954.It ip6 v6only integer yes 955.It ip6 anonportmin integer yes 956.It ip6 anonportmax integer yes 957.It ip6 lowportmin integer yes 958.It ip6 lowportmax integer yes 959.It icmp6 rediraccept integer yes 960.It icmp6 redirtimeout integer yes 961.It icmp6 nd6_prune integer yes 962.It icmp6 nd6_delay integer yes 963.It icmp6 nd6_umaxtries integer yes 964.It icmp6 nd6_mmaxtries integer yes 965.It icmp6 nd6_useloopback integer yes 966.It icmp6 nodeinfo integer yes 967.It icmp6 errppslimit integer yes 968.It icmp6 nd6_maxnudhint integer yes 969.It icmp6 mtudisc_hiwat integer yes 970.It icmp6 mtudisc_lowat integer yes 971.It icmp6 nd6_debug integer yes 972.It udp6 sendspace integer yes 973.It udp6 recvspace integer yes 974.El 975.Pp 976The variables are as follows: 977.Bl -tag -width "123456" 978.It Li ip6.forwarding 979Returns 1 when IPv6 forwarding is enabled for the node, 980meaning that the node is acting as a router. 981Returns 0 when IPv6 forwarding is disabled for the node, 982meaning that the node is acting as a host. 983IPv6 specification defines node behavior for 984.Dq router 985case and 986.Dq host 987case quite differently, and changing this variable during operation 988may cause serious trouble. 989It is recommended to configure the variable at bootstrap time, 990and bootstrap time only. 991.It Li ip6.redirect 992Returns 1 when ICMPv6 redirects may be sent by the node. 993This option is ignored unless the node is routing IP packets, 994and should normally be enabled on all systems. 995.It Li ip6.hlim 996The default hop limit value for an IPv6 unicast packet sourced by the node. 997This value applies to all the transport protocols on top of IPv6. 998There are APIs to override the value, as documented in 999.Xr ip6 4 . 1000.It Li ip6.maxfragpackets 1001The maximum number of fragmented packets the node will accept. 10020 means that the node will not accept any fragmented packets. 1003-1 means that the node will accept as many fragmented packets as it receives. 1004The flag is provided basically for avoiding possible DoS attacks. 1005.It Li ip6.accept_rtadv 1006If set to non-zero, the node will accept ICMPv6 router advertisement packets 1007and autoconfigures address prefixes and default routers. 1008The node must be a host 1009.Pq not a router 1010for the option to be meaningful. 1011.It Li ip6.keepfaith 1012If set to non-zero, it enables 1013.Dq FAITH 1014TCP relay IPv6-to-IPv4 translator code in the kernel. 1015Refer 1016.Xr faith 4 1017and 1018.Xr faithd 8 1019for detail. 1020.It Li ip6.log_interval 1021The variable controls amount of logs generated by IPv6 packet 1022forwarding engine, by seting interval between log output 1023.Pq in seconds . 1024.It Li ip6.hdrnestlimit 1025The number of IPv6 extension headers permitted on incoming IPv6 packets. 1026If set to 0, the node will accept as many extension headers as possible. 1027.It Li ip6.dad_count 1028The variable cofigures number of IPv6 DAD 1029.Pq duplicated address detection 1030probe packets. 1031The packets will be generated when IPv6 interface addresses are configured. 1032.It Li ip6.auto_flowlabel 1033On connected transport protocol packets, 1034fill IPv6 flowlabel field to help intermediate routers to identify packet flows. 1035.It Li ip6.defmcasthlim 1036The default hop limit value for an IPv6 multicast packet sourced by the node. 1037This value applies to all the transport protocols on top of IPv6. 1038There are APIs to override the value, as documented in 1039.Xr ip6 4 . 1040.It Li ip6.gif_hlim 1041The maximum hop limit value for an IPv6 packet generated by 1042.Xr gif 4 1043tunnel interface. 1044.It Li ip6.kame_version 1045The string identifies the version of KAME IPv6 stack implemented in the kernel. 1046.It Li ip6.use_deprecated 1047The variable controls use of deprecated address, specified in RFC2462 5.5.4. 1048.It Li ip6.rr_prune 1049The variable specifies interval between IPv6 router renumbering prefix 1050babysitting, in seconds. 1051.It Li ip6.v6only 1052The variable specifies initial value for 1053.Dv IPV6_V6ONLY 1054socket option for 1055.Dv AF_INET6 1056socket. 1057Please refer to 1058.Xr ip6 4 1059for detail. 1060.It Li ip6.anonportmin 1061The lowest port number to use for TCP and UDP ephemeral port allocation. 1062This cannot be set to less than 1024 or greater than 65535. 1063.It Li ip6.anonportmax 1064The highest port number to use for TCP and UDP ephemeral port allocation. 1065This cannot be set to less than 1024 or greater than 65535, and must 1066be greater than 1067.Li ip6.anonportmin . 1068.It Li ip6.lowportmin 1069The lowest port number to use for TCP and UDP reserved port allocation. 1070This cannot be set to less than 0 or greater than 1024, and must 1071be smaller than 1072.Li ip6.lowportmax . 1073.It Li ip6.lowportmax 1074The highest port number to use for TCP and UDP reserved port allocation. 1075This cannot be set to less than 0 or greater than 1024, and must 1076be greater than 1077.Li ip6.lowportmin . 1078.It Li icmp6.rediraccept 1079If set to non-zero, the host will accept ICMPv6 redirect packets. 1080Note that IPv6 routers will never accept ICMPv6 redirect packets, 1081and the variable is meaningful on IPv6 hosts 1082.Pq non-router 1083only. 1084.It Li icmp6.redirtimeout 1085The variable specifies lifetime of routing entries generated by incoming 1086ICMPv6 redirect. 1087.It Li icmp6.nd6_prune 1088The variable specifies interval between IPv6 neighbor cache babysitting, 1089in seconds. 1090.It Li icmp6.nd6_delay 1091The variable specifies 1092.Dv DELAY_FIRST_PROBE_TIME 1093timing constant in IPv6 neighbor discovery specification 1094.Pq RFC2461 , 1095in seconds. 1096.It Li icmp6.nd6_umaxtries 1097The variable specifies 1098.Dv MAX_UNICAST_SOLICIT 1099constant in IPv6 neighbor discovery specification 1100.Pq RFC2461 . 1101.It Li icmp6.nd6_mmaxtries 1102The variable specifies 1103.Dv MAX_MULTICAST_SOLICIT 1104constant in IPv6 neighbor discovery specification 1105.Pq RFC2461 . 1106.It Li icmp6.nd6_useloopback 1107If set to non-zero, kernel IPv6 stack will use loopback interface for 1108local traffic. 1109.It Li icmp6.nodeinfo 1110The variable enables responses to ICMPv6 node information queries. 1111If you set the variable to 0, reponses will not be generated for 1112ICMPv6 node information queries. 1113Since node information queries can have a security impact, it is 1114possible to fine tune which responses should be answered. 1115Two separate bits can be set. 1116.Bl -tag -width "12345" 1117.It 1 1118Respond to ICMPv6 FQDN queries, e.g. 1119.Li ping6 -w . 1120.It 2 1121Respond to ICMPv6 node addresses queries, e.g. 1122.Li ping6 -a . 1123.El 1124.It Li icmp6.errppslimit 1125The variable specifies the maximum number of outgoing ICMPv6 error messages, 1126per second. 1127ICMPv6 error messages that exceeded the value are subject to rate limitation 1128and will not go out from the node. 1129Negative value disables rate limitation. 1130.It Li icmp6.nd6_maxnudhint 1131IPv6 neighbor discovery permits upper layer protocols to supply reachability 1132hints, to avoid unnecessary neighbor discovery exchanges. 1133The variable defines the number of consecutive hints the neighbor discovery 1134layer will take. 1135For example, by setting the variable to 3, neighbor discovery layer 1136will take 3 consecutive hints in maximum. 1137After receiving 3 hints, neighbor discovery layer will perform 1138normal neighbor discovery process. 1139.It Li icmp6.mtudisc_hiwat 1140.It Li icmp6.mtudisc_lowat 1141The variables define the maximum number of routing table entries, 1142created due to path MTU discovery 1143.Pq prevents denial-of-service attacks with ICMPv6 too big messages . 1144When IPv6 path MTU discovery happens, we keep path MTU information into 1145the routing table. 1146If the number of routing table entries exceed the value, 1147the kernel will not attempt to keep the path MTU information. 1148.Li icmp6.mtudisc_hiwat 1149is used when we have verified ICMPv6 too big messages. 1150.Li icmp6.mtudisc_lowat 1151is used when we have unverified ICMPv6 too big messages. 1152Verification is performed by using address/port pairs kept in connected pcbs. 1153Negative value disables the upper limit. 1154.It Li icmp6.nd6_debug 1155If set to non-zero, kernel IPv6 neighbor discovery code will generate 1156debugging messages. 1157The debug outputs are useful to diagnose IPv6 interoperability issues. 1158The flag must be set to 0 for normal operation. 1159.El 1160.Pp 1161We reuse net.*.tcp for 1162.Tn TCP 1163over 1164.Tn IPv6 , 1165and therefore we do not have variables net.*.tcp6. 1166Variables net.inet6.udp6 have identical meaning to net.inet.udp. 1167Please refer to 1168.Li PF_INET 1169section above. 1170For variables net.*.ipsec6, please refer to 1171.Xr ipsec 4 . 1172.It Li PF_KEY 1173Get or set various global information about the IPsec key management. 1174The third level name is the variable name. 1175The currently defined variable and names are: 1176.Bl -column "blockacq_lifetime" "integer" "yes" -offset indent 1177.It Pa Variable name Type Changeable 1178.It debug integer yes 1179.It spi_try integer yes 1180.It spi_min_value integer yes 1181.It spi_max_value integer yes 1182.It random_int integer yes 1183.It larval_lifetime integer yes 1184.It blockacq_count integer yes 1185.It blockacq_lifetime integer yes 1186.It esp_keymin integer yes 1187.It esp_auth integer yes 1188.It ah_keymin integer yes 1189.El 1190The variables are as follows: 1191.Bl -tag -width "123456" 1192.It Li debug 1193Turn on debugging message from within the kernel. 1194The value is a bitmap, as defined in 1195.Pa /usr/include/netkey/key_debug.h . 1196.It Li spi_try 1197The number of times the kernel will try to obtain an unique SPI 1198when it generates it from random number generator. 1199.It Li spi_min_value 1200Minimum SPI value when generating it within the kernel. 1201.It Li spi_max_value 1202Maximum SPI value when generating it within the kernel. 1203.It Li random_int 1204Interval to stir pseudo-random number generator, in seconds. 1205Pseudo-random number generator is used only as a last resort when 1206random number source 1207.Pq Pa /dev/urandom 1208is not available. 1209It should not really be used, and if it were used, 1210kernel will warn about it. 1211.It Li larval_lifetime 1212Lifetime for LARVAL SAD entries, in seconds. 1213.It Li blockacq_count 1214Number of ACQUIRE PF_KEY messages to be blocked after an ACQUIRE message. 1215It avoids flood of ACQUIRE PF_KEY from being sent from the kernel to the 1216key management daemon. 1217.It Li blockacq_lifetime 1218Lifetime of ACQUIRE PF_KEY message. 1219.It Li esp_keymin 1220Minimum ESP key length, in bits. 1221The value is used when the kernel creates proposal payload 1222on ACQUIRE PF_KEY message. 1223.It Li esp_auth 1224Whether ESP authentication should be used or not. 1225Non-zero value indicates that ESP authentication should be used. 1226The value is used when the kernel creates proposal payload 1227on ACQUIRE PF_KEY message. 1228.It Li ah_keymin 1229Minimum AH key length, in bits, 1230The value is used when the kernel creates proposal payload 1231on ACQUIRE PF_KEY message. 1232.El 1233.El 1234.Sh CTL_PROC 1235The string and integer information available for the CTL_PROC 1236is detailed below. 1237The changeable column shows whether a process with appropriate 1238privilege may change the value. 1239These values are per-process, and as such may change from one process 1240to another. When a process is created, the default values are inherited from 1241its parent. When a set-user-ID or set-group-ID binary is executed, the 1242value of PROC_PID_CORENAME is reset to the system default value. 1243The second level name is either the magic value PROC_CURPROC, which 1244points to the current process, or the PID of the target process. 1245.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" "yes" -offset indent 1246.It Sy Pa Third level name Type Changeable 1247.It PROC\_PID\_CORENAME string yes 1248.It PROC\_PID\_LIMIT node not applicable 1249.El 1250.Bl -tag -width "123456" 1251.Pp 1252.It Li PROC_PID_CORENAME 1253The template used for the core dump file name (see 1254.Xr core 5 1255for details). The base name must either be 1256.Nm core 1257or end with the suffix ``.core'' (the super-user may set arbitrary names). By 1258default it points to KERN_DEFCORENAME. 1259.It Li PROC_PID_LIMIT 1260Return resources limits, as defined for the 1261.Xr getrlimit 2 1262and 1263.Xr setrlimit 2 1264system calls. 1265The fourth level name is one of: 1266.Bl -tag -width PROC_PID_LIMIT_MEMLOCKAA 1267.It Li PROC_PID_LIMIT_CPU 1268The maximum amount of cpu time (in seconds) to be used by each process. 1269.It Li PROC_PID_LIMIT_FSIZE 1270The largest size (in bytes) file that may be created. 1271.It Li PROC_PID_LIMIT_DATA 1272The maximum size (in bytes) of the data segment for a process; 1273this defines how far a program may extend its break with the 1274.Xr sbrk 2 1275system call. 1276.It Li PROC_PID_LIMIT_STACK 1277The maximum size (in bytes) of the stack segment for a process; 1278this defines how far a program's stack segment may be extended. 1279Stack extension is performed automatically by the system. 1280.It Li PROC_PID_LIMIT_CORE 1281The largest size (in bytes) 1282.Pa core 1283file that may be created. 1284.It Li PROC_PID_LIMIT_RSS 1285The maximum size (in bytes) to which a process's resident set size may 1286grow. 1287This imposes a limit on the amount of physical memory to be given to 1288a process; if memory is tight, the system will prefer to take memory 1289from processes that are exceeding their declared resident set size. 1290.It Li PROC_PID_LIMIT_MEMLOCK 1291The maximum size (in bytes) which a process may lock into memory 1292using the 1293.Xr mlock 2 1294function. 1295.It Li PROC_PID_LIMIT_NPROC 1296The maximum number of simultaneous processes for this user id. 1297.It Li PROC_PID_LIMIT_NOFILE 1298The maximum number of open files for this process. 1299.El 1300.Pp 1301The fifth level name is one of PROC_PID_LIMIT_TYPE_SOFT or 1302PROC_PID_LIMIT_TYPE_HARD, to select respectively the soft or hard limit. 1303Both are of type integer. 1304.El 1305.Sh CTL_USER 1306The string and integer information available for the CTL_USER level 1307is detailed below. 1308The changeable column shows whether a process with appropriate 1309privilege may change the value. 1310.Bl -column "USER_COLL_WEIGHTS_MAXXXX" "integerXXX" -offset indent 1311.It Sy Pa Second level name Type Changeable 1312.It USER\_BC\_BASE\_MAX integer no 1313.It USER\_BC\_DIM\_MAX integer no 1314.It USER\_BC\_SCALE\_MAX integer no 1315.It USER\_BC\_STRING\_MAX integer no 1316.It USER\_COLL\_WEIGHTS\_MAX integer no 1317.It USER\_CS\_PATH string no 1318.It USER\_EXPR\_NEST\_MAX integer no 1319.It USER\_LINE\_MAX integer no 1320.It USER\_POSIX2\_CHAR\_TERM integer no 1321.It USER\_POSIX2\_C\_BIND integer no 1322.It USER\_POSIX2\_C\_DEV integer no 1323.It USER\_POSIX2\_FORT\_DEV integer no 1324.It USER\_POSIX2\_FORT\_RUN integer no 1325.It USER\_POSIX2\_LOCALEDEF integer no 1326.It USER\_POSIX2\_SW\_DEV integer no 1327.It USER\_POSIX2\_UPE integer no 1328.It USER\_POSIX2\_VERSION integer no 1329.It USER\_RE\_DUP\_MAX integer no 1330.It USER\_STREAM\_MAX integer no 1331.It USER\_TZNAME\_MAX integer no 1332.El 1333.Bl -tag -width "123456" 1334.Pp 1335.It Li USER_BC_BASE_MAX 1336The maximum ibase/obase values in the 1337.Xr bc 1 1338utility. 1339.It Li USER_BC_DIM_MAX 1340The maximum array size in the 1341.Xr bc 1 1342utility. 1343.It Li USER_BC_SCALE_MAX 1344The maximum scale value in the 1345.Xr bc 1 1346utility. 1347.It Li USER_BC_STRING_MAX 1348The maximum string length in the 1349.Xr bc 1 1350utility. 1351.It Li USER_COLL_WEIGHTS_MAX 1352The maximum number of weights that can be assigned to any entry of 1353the LC_COLLATE order keyword in the locale definition file. 1354.It Li USER_CS_PATH 1355Return a value for the 1356.Ev PATH 1357environment variable that finds all the standard utilities. 1358.It Li USER_EXPR_NEST_MAX 1359The maximum number of expressions that can be nested within 1360parenthesis by the 1361.Xr expr 1 1362utility. 1363.It Li USER_LINE_MAX 1364The maximum length in bytes of a text-processing utility's input 1365line. 1366.It Li USER_POSIX2_CHAR_TERM 1367Return 1 if the system supports at least one terminal type capable of 1368all operations described in POSIX 1003.2, otherwise 0. 1369.It Li USER_POSIX2_C_BIND 1370Return 1 if the system's C-language development facilities support the 1371C-Language Bindings Option, otherwise 0. 1372.It Li USER_POSIX2_C_DEV 1373Return 1 if the system supports the C-Language Development Utilities Option, 1374otherwise 0. 1375.It Li USER_POSIX2_FORT_DEV 1376Return 1 if the system supports the FORTRAN Development Utilities Option, 1377otherwise 0. 1378.It Li USER_POSIX2_FORT_RUN 1379Return 1 if the system supports the FORTRAN Runtime Utilities Option, 1380otherwise 0. 1381.It Li USER_POSIX2_LOCALEDEF 1382Return 1 if the system supports the creation of locales, otherwise 0. 1383.It Li USER_POSIX2_SW_DEV 1384Return 1 if the system supports the Software Development Utilities Option, 1385otherwise 0. 1386.It Li USER_POSIX2_UPE 1387Return 1 if the system supports the User Portability Utilities Option, 1388otherwise 0. 1389.It Li USER_POSIX2_VERSION 1390The version of POSIX 1003.2 with which the system attempts to comply. 1391.It Li USER_RE_DUP_MAX 1392The maximum number of repeated occurrences of a regular expression 1393permitted when using interval notation. 1394.ne 1i 1395.It Li USER_STREAM_MAX 1396The minimum maximum number of streams that a process may have open 1397at any one time. 1398.It Li USER_TZNAME_MAX 1399The minimum maximum number of types supported for the name of a 1400timezone. 1401.El 1402.Sh CTL_VM 1403The string and integer information available for the CTL_VM level 1404is detailed below. 1405The changeable column shows whether a process with appropriate 1406privilege may change the value. 1407.Bl -column "Second level nameXXXXXX" "struct loadavgXXX" -offset indent 1408.It Sy Pa Second level name Type Changeable 1409.It VM\_ANONMAX int yes 1410.It VM\_ANONMIN int yes 1411.It VM\_EXECMAX int yes 1412.It VM\_EXECMIN int yes 1413.It VM\_FILEMAX int yes 1414.It VM\_FILEMIN int yes 1415.It VM\_LOADAVG struct loadavg no 1416.It VM\_MAXSLP int no 1417.It VM\_METER struct vmtotal no 1418.It VM\_NKMEMPAGES int no 1419.It VM\_USPACE int no 1420.It VM\_UVMEXP struct uvmexp no 1421.It VM\_UVMEXP2 struct uvmexp_sysctl no 1422.El 1423.Pp 1424.Bl -tag -width "123456" 1425.It Li VM_ANONMAX 1426The percentage of physical memory which will be reclaimed 1427from other types of memory usage to store anonymous application data. 1428.It Li VM_ANONMIN 1429The percentage of physical memory which will be always be available for 1430anonymous application data. 1431.It Li VM_EXECMAX 1432The percentage of physical memory which will be reclaimed 1433from other types of memory usage to store cached executable data. 1434.It Li VM_EXECMIN 1435The percentage of physical memory which will be always be available for 1436cached executable data. 1437.It Li VM_FILEMAX 1438The percentage of physical memory which will be reclaimed 1439from other types of memory usage to store cached file data. 1440.It Li VM_FILEMIN 1441The percentage of physical memory which will be always be available for 1442cached file data. 1443.It Li VM_LOADAVG 1444Return the load average history. 1445The returned data consists of a 1446.Va struct loadavg . 1447.It Li VM_MAXSLP 1448The value of the maxslp kernel global variable. 1449.It Li VM_METER 1450Return system wide virtual memory statistics. 1451The returned data consists of a 1452.Va struct vmtotal . 1453.It Li VM_USPACE 1454The number of bytes allocated for each kernel stack. 1455.It Li VM_UVMEXP 1456Return system wide virtual memory statistics. 1457The returned data consists of a 1458.Va struct uvmexp . 1459.It Li VM_UVMEXP2 1460Return system wide virtual memory statistics. 1461The returned data consists of a 1462.Va struct uvmexp_sysctl . 1463.El 1464.Sh CTL_DDB 1465The integer information available for the CTL_DDB level is detailed below. 1466The changeable column shows whether a process with appropriate 1467privilege may change the value. 1468.Bl -column "DBCTL_TABSTOPSXXX" "integerXXX" -offset indent 1469.It Sy Pa Second level name Type Changeable 1470.It DBCTL\_RADIX integer yes 1471.It DBCTL\_MAXOFF integer yes 1472.It DBCTL\_LINES integer yes 1473.It DBCTL\_TABSTOPS integer yes 1474.It DBCTL\_ONPANIC integer yes 1475.It DBCTL\_FROMCONSOLE integer yes 1476.El 1477.Pp 1478.Bl -tag -width "123456" 1479.It Li DBCTL_RADIX 1480The input and output radix. 1481.It Li DBCTL_MAXOFF 1482The maximum symbol offset. 1483.It Li DBCTL_LINES 1484Number of display lines. 1485.It Li DBCTL_TABSTOPS 1486Tab width. 1487.It Li DBCTL_ONPANIC 1488If non-zero, DDB will be entered when the kernel panics. 1489.It Li DBCTL_FROMCONSOLE 1490If not zero, DDB may be entered by sending a break on a serial 1491console or by a special key sequence on a graphics console. 1492.El 1493.Pp 1494These MIB nodes are also available as variables from within the 1495DDB. See 1496.Xr ddb 4 1497for more details. 1498.Sh CTL_VENDOR 1499The "vendor" toplevel name is reserved to be used by vendors who wish to 1500have their own private MIB tree. Intended use is to store values under 1501.Dq vendor.\*[Lt]yourname\*[Gt].* . 1502.Sh RETURN VALUES 1503If the call to 1504.Nm 1505is successful, the number of bytes copied out is returned. 1506Otherwise \-1 is returned and 1507.Va errno 1508is set appropriately. 1509.Sh FILES 1510.Bl -tag -width \*[Lt]netinet6/udp6Xvar.h\*[Gt] -compact 1511.It Pa Aq sys/sysctl.h 1512definitions for top level identifiers, second level kernel and hardware 1513identifiers, and user level identifiers 1514.It Pa Aq sys/socket.h 1515definitions for second level network identifiers 1516.It Pa Aq sys/gmon.h 1517definitions for third level profiling identifiers 1518.It Pa Aq uvm/uvm_param.h 1519definitions for second level virtual memory identifiers 1520.It Pa Aq netinet/in.h 1521definitions for third level IPv4/v6 identifiers and 1522fourth level IPv4/v6 identifiers 1523.It Pa Aq netinet/icmp_var.h 1524definitions for fourth level ICMP identifiers 1525.It Pa Aq netinet/icmp6.h 1526definitions for fourth level ICMPv6 identifiers 1527.It Pa Aq netinet/tcp_var.h 1528definitions for fourth level TCP identifiers 1529.It Pa Aq netinet/udp_var.h 1530definitions for fourth level UDP identifiers 1531.It Pa Aq netinet6/udp6_var.h 1532definitions for fourth level IPv6 UDP identifiers 1533.It Pa Aq netinet6/ipsec.h 1534definitions for fourth level IPsec identifiers 1535.It Pa Aq netkey/key_var.h 1536definitions for third level PF_KEY identifiers 1537.El 1538.Sh ERRORS 1539The following errors may be reported: 1540.Bl -tag -width Er 1541.It Bq Er EFAULT 1542The buffer 1543.Fa name , 1544.Fa oldp , 1545.Fa newp , 1546or length pointer 1547.Fa oldlenp 1548contains an invalid address. 1549.It Bq Er EINVAL 1550The 1551.Fa name 1552array is less than two or greater than CTL_MAXNAME. 1553.It Bq Er EINVAL 1554A non-null 1555.Fa newp 1556is given and its specified length in 1557.Fa newlen 1558is too large or too small. 1559.It Bq Er ENOMEM 1560The length pointed to by 1561.Fa oldlenp 1562is too short to hold the requested value. 1563.It Bq Er ENOTDIR 1564The 1565.Fa name 1566array specifies an intermediate rather than terminal name. 1567.It Bq Er EOPNOTSUPP 1568The 1569.Fa name 1570array specifies a value that is unknown. 1571.It Bq Er EPERM 1572An attempt is made to set a read-only value. 1573.It Bq Er EPERM 1574A process without appropriate privilege attempts to set a value. 1575.It Bq Er EPERM 1576An attempt to change a value protected by the current kernel security 1577level is made. 1578.El 1579.Sh SEE ALSO 1580.Xr ipsec 4 , 1581.Xr sysctl 8 1582.Sh HISTORY 1583The 1584.Nm 1585function first appeared in 1586.Bx 4.4 . 1587