1// Copyright 2018 Tobias Klauser. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package sysconf
6
7import "golang.org/x/sys/unix"
8
9const (
10	_HOST_NAME_MAX  = _MAXHOSTNAMELEN - 1
11	_LOGIN_NAME_MAX = _MAXLOGNAME
12	_SYMLOOP_MAX    = _MAXSYMLINKS
13)
14
15// sysconf implements sysconf(3) as in the FreeBSD 12 libc.
16func sysconf(name int) (int64, error) {
17	switch name {
18	case SC_AIO_LISTIO_MAX:
19		return sysctl32("p1003_1b.aio_listio_max"), nil
20	case SC_AIO_MAX:
21		return sysctl32("p1003_1b.aio_max"), nil
22	case SC_AIO_PRIO_DELTA_MAX:
23		return sysctl32("p1003_1b.aio_prio_delta_max"), nil
24	case SC_ARG_MAX:
25		return sysctl32("kern.argmax"), nil
26	case SC_ATEXIT_MAX:
27		return _ATEXIT_SIZE, nil
28	case SC_CHILD_MAX:
29		var rlim unix.Rlimit
30		if err := unix.Getrlimit(unix.RLIMIT_NPROC, &rlim); err == nil {
31			if rlim.Cur != unix.RLIM_INFINITY {
32				return rlim.Cur, nil
33			}
34		}
35		return -1, nil
36	case SC_CLK_TCK:
37		return _CLK_TCK, nil
38	case SC_DELAYTIMER_MAX:
39		return sysctl32("p1003_1b.delaytimer_max"), nil
40	case SC_GETGR_R_SIZE_MAX, SC_GETPW_R_SIZE_MAX:
41		return -1, nil
42	case SC_IOV_MAX:
43		return sysctl32("kern.iov_max"), nil
44	case SC_MQ_OPEN_MAX:
45		return yesno(sysctl32("p1003_1b.mq_open_max")), nil
46	case SC_MQ_PRIO_MAX:
47		return _MQ_PRIO_MAX, nil
48	case SC_NGROUPS_MAX:
49		return sysctl32("kern.ngroups"), nil
50	case SC_OPEN_MAX:
51		var rlim unix.Rlimit
52		if err := unix.Getrlimit(unix.RLIMIT_NOFILE, &rlim); err == nil {
53			if rlim.Cur != unix.RLIM_INFINITY {
54				return rlim.Cur, nil
55			}
56		}
57		return -1, nil
58	case SC_RTSIG_MAX:
59		return sysctl32("p1003_1b.rtsig_max"), nil
60	case SC_SEM_NSEMS_MAX:
61		return -1, nil
62	case SC_SEM_VALUE_MAX:
63		return _SEM_VALUE_MAX, nil
64	case SC_SIGQUEUE_MAX:
65		return sysctl32("p1003_1b.sigqueue_max"), nil
66	case SC_STREAM_MAX:
67		var rlim unix.Rlimit
68		if err := unix.Getrlimit(unix.RLIMIT_NOFILE, &rlim); err != nil {
69			return -1, nil
70		}
71		if rlim.Cur == unix.RLIM_INFINITY {
72			return -1, nil
73		}
74		if rlim.Cur > _LONG_MAX {
75			return -1, unix.EOVERFLOW
76		}
77		if rlim.Cur > _SHRT_MAX {
78			return _SHRT_MAX, nil
79		}
80		return rlim.Cur, nil
81	case SC_THREAD_DESTRUCTOR_ITERATIONS:
82		return _PTHREAD_DESTRUCTOR_ITERATIONS, nil
83	case SC_THREAD_KEYS_MAX:
84		return _PTHREAD_KEYS_MAX, nil
85	case SC_THREAD_PRIO_INHERIT:
86		return _POSIX_THREAD_PRIO_INHERIT, nil
87	case SC_THREAD_PRIO_PROTECT:
88		return _POSIX_THREAD_PRIO_PROTECT, nil
89	case SC_THREAD_STACK_MIN:
90		return _PTHREAD_STACK_MIN, nil
91	case SC_THREAD_THREADS_MAX:
92		return -1, nil
93	case SC_TIMER_MAX:
94		return yesno(sysctl32("p1003_1b.timer_max")), nil
95	case SC_TTY_NAME_MAX:
96		return pathconf(_PATH_DEV, _PC_NAME_MAX), nil
97	case SC_TZNAME_MAX:
98		return pathconf(_PATH_ZONEINFO, _PC_NAME_MAX), nil
99
100	case SC_IPV6:
101		if _POSIX_IPV6 == 0 {
102			fd, err := unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, 0)
103			if err == nil && fd >= 0 {
104				unix.Close(fd)
105				return int64(200112), nil
106			}
107			return 0, nil
108		}
109		return _POSIX_IPV6, nil
110	case SC_MESSAGE_PASSING:
111		if _POSIX_MESSAGE_PASSING == 0 {
112			return yesno(sysctl32("p1003_1b.message_passing")), nil
113		}
114		return _POSIX_MESSAGE_PASSING, nil
115	case SC_PRIORITIZED_IO:
116		if _POSIX_PRIORITIZED_IO == 0 {
117			return yesno(sysctl32("p1003_1b.prioritized_io")), nil
118		}
119		return _POSIX_PRIORITIZED_IO, nil
120	case SC_PRIORITY_SCHEDULING:
121		if _POSIX_PRIORITY_SCHEDULING == 0 {
122			return yesno(sysctl32("p1003_1b.priority_scheduling")), nil
123		}
124		return _POSIX_PRIORITY_SCHEDULING, nil
125	case SC_REALTIME_SIGNALS:
126		if _POSIX_REALTIME_SIGNALS == 0 {
127			return yesno(sysctl32("p1003_1b.realtime_signals")), nil
128		}
129		return _POSIX_REALTIME_SIGNALS, nil
130	case SC_SAVED_IDS:
131		return yesno(sysctl32("kern.saved_ids")), nil
132	case SC_SEMAPHORES:
133		if _POSIX_SEMAPHORES == 0 {
134			return yesno(sysctl32("p1003_1b.semaphores")), nil
135		}
136		return _POSIX_SEMAPHORES, nil
137	case SC_SPAWN:
138		return _POSIX_SPAWN, nil
139	case SC_SPIN_LOCKS:
140		return _POSIX_SPIN_LOCKS, nil
141	case SC_SPORADIC_SERVER:
142		return _POSIX_SPORADIC_SERVER, nil
143	case SC_SYNCHRONIZED_IO:
144		if _POSIX_SYNCHRONIZED_IO == 0 {
145			return yesno(sysctl32("p1003_1b.synchronized_io")), nil
146		}
147		return _POSIX_SYNCHRONIZED_IO, nil
148	case SC_THREAD_ATTR_STACKADDR:
149		return _POSIX_THREAD_ATTR_STACKADDR, nil
150	case SC_THREAD_ATTR_STACKSIZE:
151		return _POSIX_THREAD_ATTR_STACKSIZE, nil
152	case SC_THREAD_CPUTIME:
153		return _POSIX_THREAD_CPUTIME, nil
154	case SC_THREAD_PRIORITY_SCHEDULING:
155		return _POSIX_THREAD_PRIORITY_SCHEDULING, nil
156	case SC_THREAD_PROCESS_SHARED:
157		return _POSIX_THREAD_PROCESS_SHARED, nil
158	case SC_THREAD_SAFE_FUNCTIONS:
159		return _POSIX_THREAD_SAFE_FUNCTIONS, nil
160	case SC_TIMERS:
161		if _POSIX_TIMERS == 0 {
162			return yesno(sysctl32("p1003_1b.timers")), nil
163		}
164		return _POSIX_TIMERS, nil
165	case SC_TRACE:
166		return _POSIX_TRACE, nil
167	case SC_TYPED_MEMORY_OBJECTS:
168		return _POSIX_TYPED_MEMORY_OBJECTS, nil
169	case SC_VERSION:
170		// TODO(tk): FreeBSD libc uses sysctl(CTL_KERN, KERN_POSIX1)
171		return _POSIX_VERSION, nil
172
173		/* TODO(tk): these need GOARCH-dependent integer size checks
174		case SC_V6_ILP32_OFF32:
175			return _V6_ILP32_OFF32, nil
176		case SC_V6_ILP32_OFFBIG:
177			return _V6_ILP32_OFFBIG, nil
178		case SC_V6_LP64_OFF64:
179			return _V6_LP64_OFF64, nil
180		case SC_V6_LPBIG_OFFBIG:
181			return _V6_LPBIG_OFFBIG, nil
182		*/
183
184	case SC_2_CHAR_TERM:
185		return _POSIX2_CHAR_TERM, nil
186	case SC_2_PBS,
187		SC_2_PBS_ACCOUNTING,
188		SC_2_PBS_CHECKPOINT,
189		SC_2_PBS_LOCATE,
190		SC_2_PBS_MESSAGE,
191		SC_2_PBS_TRACK:
192		return _POSIX2_PBS, nil
193	case SC_2_UPE:
194		return _POSIX2_UPE, nil
195
196	case SC_XOPEN_CRYPT:
197		return _XOPEN_CRYPT, nil
198	case SC_XOPEN_ENH_I18N:
199		return _XOPEN_ENH_I18N, nil
200	case SC_XOPEN_REALTIME:
201		return _XOPEN_REALTIME, nil
202	case SC_XOPEN_REALTIME_THREADS:
203		return _XOPEN_REALTIME_THREADS, nil
204	case SC_XOPEN_SHM:
205		return _XOPEN_SHM, nil
206	case SC_XOPEN_STREAMS:
207		return -1, nil
208	case SC_XOPEN_UNIX:
209		return _XOPEN_UNIX, nil
210
211	case SC_PHYS_PAGES:
212		if val, err := unix.SysctlUint64("hw.availpages"); err == nil {
213			return int64(val), nil
214		}
215		return -1, nil
216	case SC_NPROCESSORS_CONF:
217		fallthrough
218	case SC_NPROCESSORS_ONLN:
219		if val, err := unix.SysctlUint32("hw.ncpu"); err == nil {
220			return int64(val), nil
221		}
222		return -1, nil
223	}
224
225	return sysconfGeneric(name)
226}
227