rework sysconf table to treat zero entries as invalid
[musl] / src / conf / sysconf.c
1 #include <unistd.h>
2 #include <limits.h>
3 #include <errno.h>
4 #include <sys/resource.h>
5 #include <signal.h>
6 #include <sys/sysinfo.h>
7 #include "syscall.h"
8 #include "libc.h"
9
10 #define JT(x) (-256|(x))
11 #define VER JT(1)
12 #define JT_ARG_MAX JT(2)
13 #define JT_MQ_PRIO_MAX JT(3)
14 #define JT_PAGE_SIZE JT(4)
15 #define JT_SEM_VALUE_MAX JT(5)
16 #define JT_NPROCESSORS_CONF JT(6)
17 #define JT_NPROCESSORS_ONLN JT(7)
18 #define JT_PHYS_PAGES JT(8)
19 #define JT_AVPHYS_PAGES JT(9)
20 #define JT_ZERO JT(10)
21
22 #define RLIM(x) (-32768|(RLIMIT_ ## x))
23
24 long sysconf(int name)
25 {
26         static const short values[] = {
27                 [_SC_ARG_MAX] = JT_ARG_MAX,
28                 [_SC_CHILD_MAX] = RLIM(NPROC),
29                 [_SC_CLK_TCK] = 100,
30                 [_SC_NGROUPS_MAX] = 32,
31                 [_SC_OPEN_MAX] = RLIM(NOFILE),
32                 [_SC_STREAM_MAX] = -1,
33                 [_SC_TZNAME_MAX] = TZNAME_MAX,
34                 [_SC_JOB_CONTROL] = 1,
35                 [_SC_SAVED_IDS] = 1,
36                 [_SC_REALTIME_SIGNALS] = 1,
37                 [_SC_PRIORITY_SCHEDULING] = -1,
38                 [_SC_TIMERS] = VER,
39                 [_SC_ASYNCHRONOUS_IO] = VER,
40                 [_SC_PRIORITIZED_IO] = -1,
41                 [_SC_SYNCHRONIZED_IO] = -1,
42                 [_SC_FSYNC] = VER,
43                 [_SC_MAPPED_FILES] = VER,
44                 [_SC_MEMLOCK] = VER,
45                 [_SC_MEMLOCK_RANGE] = VER,
46                 [_SC_MEMORY_PROTECTION] = VER,
47                 [_SC_MESSAGE_PASSING] = VER,
48                 [_SC_SEMAPHORES] = VER,
49                 [_SC_SHARED_MEMORY_OBJECTS] = VER,
50                 [_SC_AIO_LISTIO_MAX] = -1,
51                 [_SC_AIO_MAX] = -1,
52                 [_SC_AIO_PRIO_DELTA_MAX] = JT_ZERO, /* ?? */
53                 [_SC_DELAYTIMER_MAX] = _POSIX_DELAYTIMER_MAX,
54                 [_SC_MQ_OPEN_MAX] = -1,
55                 [_SC_MQ_PRIO_MAX] = JT_MQ_PRIO_MAX,
56                 [_SC_VERSION] = VER,
57                 [_SC_PAGE_SIZE] = JT_PAGE_SIZE,
58                 [_SC_RTSIG_MAX] = _NSIG - 1 - 31 - 3,
59                 [_SC_SEM_NSEMS_MAX] = SEM_NSEMS_MAX,
60                 [_SC_SEM_VALUE_MAX] = JT_SEM_VALUE_MAX,
61                 [_SC_SIGQUEUE_MAX] = -1,
62                 [_SC_TIMER_MAX] = -1,
63                 [_SC_BC_BASE_MAX] = _POSIX2_BC_BASE_MAX,
64                 [_SC_BC_DIM_MAX] = _POSIX2_BC_DIM_MAX,
65                 [_SC_BC_SCALE_MAX] = _POSIX2_BC_SCALE_MAX,
66                 [_SC_BC_STRING_MAX] = _POSIX2_BC_STRING_MAX,
67                 [_SC_COLL_WEIGHTS_MAX] = COLL_WEIGHTS_MAX,
68                 [_SC_EQUIV_CLASS_MAX] = -1, /* ?? */
69                 [_SC_EXPR_NEST_MAX] = -1,
70                 [_SC_LINE_MAX] = -1,
71                 [_SC_RE_DUP_MAX] = RE_DUP_MAX,
72                 [_SC_CHARCLASS_NAME_MAX] = -1, /* ?? */
73                 [_SC_2_VERSION] = VER,
74                 [_SC_2_C_BIND] = VER,
75                 [_SC_2_C_DEV] = -1,
76                 [_SC_2_FORT_DEV] = -1,
77                 [_SC_2_FORT_RUN] = -1,
78                 [_SC_2_SW_DEV] = -1,
79                 [_SC_2_LOCALEDEF] = -1,
80                 [_SC_PII] = -1, /* ????????? */
81                 [_SC_PII_XTI] = -1,
82                 [_SC_PII_SOCKET] = -1,
83                 [_SC_PII_INTERNET] = -1,
84                 [_SC_PII_OSI] = -1,
85                 [_SC_POLL] = 1,
86                 [_SC_SELECT] = 1,
87                 [_SC_IOV_MAX] = IOV_MAX,
88                 [_SC_PII_INTERNET_STREAM] = -1,
89                 [_SC_PII_INTERNET_DGRAM] = -1,
90                 [_SC_PII_OSI_COTS] = -1,
91                 [_SC_PII_OSI_CLTS] = -1,
92                 [_SC_PII_OSI_M] = -1,
93                 [_SC_T_IOV_MAX] = -1,
94                 [_SC_THREADS] = VER,
95                 [_SC_THREAD_SAFE_FUNCTIONS] = VER,
96                 [_SC_GETGR_R_SIZE_MAX] = -1,
97                 [_SC_GETPW_R_SIZE_MAX] = -1,
98                 [_SC_LOGIN_NAME_MAX] = 256,
99                 [_SC_TTY_NAME_MAX] = TTY_NAME_MAX,
100                 [_SC_THREAD_DESTRUCTOR_ITERATIONS] = PTHREAD_DESTRUCTOR_ITERATIONS,
101                 [_SC_THREAD_KEYS_MAX] = PTHREAD_KEYS_MAX,
102                 [_SC_THREAD_STACK_MIN] = PTHREAD_STACK_MIN,
103                 [_SC_THREAD_THREADS_MAX] = -1,
104                 [_SC_THREAD_ATTR_STACKADDR] = VER,
105                 [_SC_THREAD_ATTR_STACKSIZE] = VER,
106                 [_SC_THREAD_PRIORITY_SCHEDULING] = VER,
107                 [_SC_THREAD_PRIO_INHERIT] = -1,
108                 [_SC_THREAD_PRIO_PROTECT] = -1,
109                 [_SC_THREAD_PROCESS_SHARED] = VER,
110                 [_SC_NPROCESSORS_CONF] = JT_NPROCESSORS_CONF,
111                 [_SC_NPROCESSORS_ONLN] = JT_NPROCESSORS_ONLN,
112                 [_SC_PHYS_PAGES] = JT_PHYS_PAGES,
113                 [_SC_AVPHYS_PAGES] = JT_AVPHYS_PAGES,
114                 [_SC_ATEXIT_MAX] = -1,
115                 [_SC_PASS_MAX] = -1,
116                 [_SC_XOPEN_VERSION] = _XOPEN_VERSION,
117                 [_SC_XOPEN_XCU_VERSION] = _XOPEN_VERSION,
118                 [_SC_XOPEN_UNIX] = 1,
119                 [_SC_XOPEN_CRYPT] = -1,
120                 [_SC_XOPEN_ENH_I18N] = 1,
121                 [_SC_XOPEN_SHM] = 1,
122                 [_SC_2_CHAR_TERM] = -1,
123                 [_SC_2_C_VERSION] = -1,
124                 [_SC_2_UPE] = -1,
125                 [_SC_XOPEN_XPG2] = -1,
126                 [_SC_XOPEN_XPG3] = -1,
127                 [_SC_XOPEN_XPG4] = -1,
128                 [_SC_CHAR_BIT] = -1,
129                 [_SC_CHAR_MAX] = -1,
130                 [_SC_CHAR_MIN] = -1,
131                 [_SC_INT_MAX] = -1,
132                 [_SC_INT_MIN] = -1,
133                 [_SC_LONG_BIT] = -1,
134                 [_SC_WORD_BIT] = -1,
135                 [_SC_MB_LEN_MAX] = -1,
136                 [_SC_NZERO] = NZERO,
137                 [_SC_SSIZE_MAX] = -1,
138                 [_SC_SCHAR_MAX] = -1,
139                 [_SC_SCHAR_MIN] = -1,
140                 [_SC_SHRT_MAX] = -1,
141                 [_SC_SHRT_MIN] = -1,
142                 [_SC_UCHAR_MAX] = -1,
143                 [_SC_UINT_MAX] = -1,
144                 [_SC_ULONG_MAX] = -1,
145                 [_SC_USHRT_MAX] = -1,
146                 [_SC_NL_ARGMAX] = -1,
147                 [_SC_NL_LANGMAX] = -1,
148                 [_SC_NL_MSGMAX] = -1,
149                 [_SC_NL_NMAX] = -1,
150                 [_SC_NL_SETMAX] = -1,
151                 [_SC_NL_TEXTMAX] = -1,
152                 [_SC_XBS5_ILP32_OFF32] = -1,
153                 [_SC_XBS5_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : JT_ZERO,
154                 [_SC_XBS5_LP64_OFF64] = sizeof(long)==8 ? 1 : JT_ZERO,
155                 [_SC_XBS5_LPBIG_OFFBIG] = -1,
156                 [_SC_XOPEN_LEGACY] = -1,
157                 [_SC_XOPEN_REALTIME] = -1,
158                 [_SC_XOPEN_REALTIME_THREADS] = -1,
159                 [_SC_ADVISORY_INFO] = VER,
160                 [_SC_BARRIERS] = VER,
161                 [_SC_BASE] = -1,
162                 [_SC_C_LANG_SUPPORT] = -1,
163                 [_SC_C_LANG_SUPPORT_R] = -1,
164                 [_SC_CLOCK_SELECTION] = VER,
165                 [_SC_CPUTIME] = VER,
166                 [_SC_THREAD_CPUTIME] = VER,
167                 [_SC_DEVICE_IO] = -1,
168                 [_SC_DEVICE_SPECIFIC] = -1,
169                 [_SC_DEVICE_SPECIFIC_R] = -1,
170                 [_SC_FD_MGMT] = -1,
171                 [_SC_FIFO] = -1,
172                 [_SC_PIPE] = -1,
173                 [_SC_FILE_ATTRIBUTES] = -1,
174                 [_SC_FILE_LOCKING] = -1,
175                 [_SC_FILE_SYSTEM] = -1,
176                 [_SC_MONOTONIC_CLOCK] = VER,
177                 [_SC_MULTI_PROCESS] = -1,
178                 [_SC_SINGLE_PROCESS] = -1,
179                 [_SC_NETWORKING] = -1,
180                 [_SC_READER_WRITER_LOCKS] = VER,
181                 [_SC_SPIN_LOCKS] = VER,
182                 [_SC_REGEXP] = 1,
183                 [_SC_REGEX_VERSION] = -1,
184                 [_SC_SHELL] = 1,
185                 [_SC_SIGNALS] = -1,
186                 [_SC_SPAWN] = VER,
187                 [_SC_SPORADIC_SERVER] = -1,
188                 [_SC_THREAD_SPORADIC_SERVER] = -1,
189                 [_SC_SYSTEM_DATABASE] = -1,
190                 [_SC_SYSTEM_DATABASE_R] = -1,
191                 [_SC_TIMEOUTS] = VER,
192                 [_SC_TYPED_MEMORY_OBJECTS] = -1,
193                 [_SC_USER_GROUPS] = -1,
194                 [_SC_USER_GROUPS_R] = -1,
195                 [_SC_2_PBS] = -1,
196                 [_SC_2_PBS_ACCOUNTING] = -1,
197                 [_SC_2_PBS_LOCATE] = -1,
198                 [_SC_2_PBS_MESSAGE] = -1,
199                 [_SC_2_PBS_TRACK] = -1,
200                 [_SC_SYMLOOP_MAX] = SYMLOOP_MAX,
201                 [_SC_STREAMS] = JT_ZERO,
202                 [_SC_2_PBS_CHECKPOINT] = -1,
203                 [_SC_V6_ILP32_OFF32] = -1,
204                 [_SC_V6_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : JT_ZERO,
205                 [_SC_V6_LP64_OFF64] = sizeof(long)==8 ? 1 : JT_ZERO,
206                 [_SC_V6_LPBIG_OFFBIG] = -1,
207                 [_SC_HOST_NAME_MAX] = HOST_NAME_MAX,
208                 [_SC_TRACE] = -1,
209                 [_SC_TRACE_EVENT_FILTER] = -1,
210                 [_SC_TRACE_INHERIT] = -1,
211                 [_SC_TRACE_LOG] = -1,
212
213                 [_SC_IPV6] = VER,
214                 [_SC_RAW_SOCKETS] = VER,
215                 [_SC_V7_ILP32_OFF32] = -1,
216                 [_SC_V7_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : JT_ZERO,
217                 [_SC_V7_LP64_OFF64] = sizeof(long)==8 ? 1 : JT_ZERO,
218                 [_SC_V7_LPBIG_OFFBIG] = -1,
219                 [_SC_SS_REPL_MAX] = -1,
220                 [_SC_TRACE_EVENT_NAME_MAX] = -1,
221                 [_SC_TRACE_NAME_MAX] = -1,
222                 [_SC_TRACE_SYS_MAX] = -1,
223                 [_SC_TRACE_USER_EVENT_MAX] = -1,
224                 [_SC_XOPEN_STREAMS] = JT_ZERO,
225                 [_SC_THREAD_ROBUST_PRIO_INHERIT] = -1,
226                 [_SC_THREAD_ROBUST_PRIO_PROTECT] = -1,
227         };
228
229         if (name >= sizeof(values)/sizeof(values[0]) || !values[name]) {
230                 errno = EINVAL;
231                 return -1;
232         } else if (values[name] >= -1) {
233                 return values[name];
234         } else if (values[name] < -256) {
235                 struct rlimit lim;
236                 getrlimit(values[name]&16383, &lim);
237                 return lim.rlim_cur > LONG_MAX ? LONG_MAX : lim.rlim_cur;
238         }
239
240         switch ((unsigned char)values[name]) {
241         case VER & 255:
242                 return _POSIX_VERSION;
243         case JT_ARG_MAX & 255:
244                 return ARG_MAX;
245         case JT_MQ_PRIO_MAX & 255:
246                 return MQ_PRIO_MAX;
247         case JT_PAGE_SIZE & 255:
248                 return PAGE_SIZE;
249         case JT_SEM_VALUE_MAX & 255:
250                 return SEM_VALUE_MAX;
251         case JT_NPROCESSORS_CONF & 255:
252         case JT_NPROCESSORS_ONLN & 255: ;
253                 unsigned char set[128] = {1};
254                 int i, cnt;
255                 __syscall(SYS_sched_getaffinity, 0, sizeof set, set);
256                 for (i=cnt=0; i<sizeof set; i++)
257                         for (; set[i]; set[i]&=set[i]-1, cnt++);
258                 return cnt;
259         case JT_PHYS_PAGES & 255:
260         case JT_AVPHYS_PAGES & 255: ;
261                 unsigned long long mem;
262                 int __lsysinfo(struct sysinfo *);
263                 struct sysinfo si;
264                 __lsysinfo(&si);
265                 if (!si.mem_unit) si.mem_unit = 1;
266                 if (name==_SC_PHYS_PAGES) mem = si.totalram;
267                 else mem = si.freeram + si.bufferram;
268                 mem *= si.mem_unit;
269                 mem /= PAGE_SIZE;
270                 return (mem > LONG_MAX) ? LONG_MAX : mem;
271         case JT_ZERO & 255:
272                 return 0;
273         }
274         return values[name];
275 }