src/basic/rlimit-util.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <sys/resource.h>
  22
  23 #include "alloc-util.h"
  24 #include "extract-word.h"
  25 #include "format-util.h"
  26 #include "macro.h"
  27 #include "missing.h"
  28 #include "rlimit-util.h"
  29 #include "string-table.h"
  30 #include "time-util.h"
  31
  32 int setrlimit_closest(int resource, const struct rlimit *rlim) {
  33         struct rlimit highest, fixed;
  34
  35         assert(rlim);
  36
  37         if (setrlimit(resource, rlim) >= 0)
  38                 return 0;
  39
  40         if (errno != EPERM)
  41                 return -errno;
  42
  43         /* So we failed to set the desired setrlimit, then let's try
  44          * to get as close as we can */
  45         if (getrlimit(resource, &highest) < 0)
  46                 return -errno;
  47
  48         fixed.rlim_cur = MIN(rlim->rlim_cur, highest.rlim_max);
  49         fixed.rlim_max = MIN(rlim->rlim_max, highest.rlim_max);
  50
  51         if (setrlimit(resource, &fixed) < 0)
  52                 return -errno;
  53
  54         return 0;
  55 }
  56
  57 static int rlimit_parse_u64(const char *val, rlim_t *ret) {
  58         uint64_t u;
  59         int r;
  60
  61         assert(val);
  62         assert(ret);
  63
  64         if (streq(val, "infinity")) {
  65                 *ret = RLIM_INFINITY;
  66                 return 0;
  67         }
  68
  69         /* setrlimit(2) suggests rlim_t is always 64bit on Linux. */
  70         assert_cc(sizeof(rlim_t) == sizeof(uint64_t));
  71
  72         r = safe_atou64(val, &u);
  73         if (r < 0)
  74                 return r;
  75         if (u >= (uint64_t) RLIM_INFINITY)
  76                 return -ERANGE;
  77
  78         *ret = (rlim_t) u;
  79         return 0;
  80 }
  81
  82 static int rlimit_parse_size(const char *val, rlim_t *ret) {
  83         uint64_t u;
  84         int r;
  85
  86         assert(val);
  87         assert(ret);
  88
  89         if (streq(val, "infinity")) {
  90                 *ret = RLIM_INFINITY;
  91                 return 0;
  92         }
  93
  94         r = parse_size(val, 1024, &u);
  95         if (r < 0)
  96                 return r;
  97         if (u >= (uint64_t) RLIM_INFINITY)
  98                 return -ERANGE;
  99
 100         *ret = (rlim_t) u;
 101         return 0;
 102 }
 103
 104 static int rlimit_parse_sec(const char *val, rlim_t *ret) {
 105         uint64_t u;
 106         usec_t t;
 107         int r;
 108
 109         assert(val);
 110         assert(ret);
 111
 112         if (streq(val, "infinity")) {
 113                 *ret = RLIM_INFINITY;
 114                 return 0;
 115         }
 116
 117         r = parse_sec(val, &t);
 118         if (r < 0)
 119                 return r;
 120         if (t == USEC_INFINITY) {
 121                 *ret = RLIM_INFINITY;
 122                 return 0;
 123         }
 124
 125         u = (uint64_t) DIV_ROUND_UP(t, USEC_PER_SEC);
 126         if (u >= (uint64_t) RLIM_INFINITY)
 127                 return -ERANGE;
 128
 129         *ret = (rlim_t) u;
 130         return 0;
 131 }
 132
 133 static int rlimit_parse_usec(const char *val, rlim_t *ret) {
 134         usec_t t;
 135         int r;
 136
 137         assert(val);
 138         assert(ret);
 139
 140         if (streq(val, "infinity")) {
 141                 *ret = RLIM_INFINITY;
 142                 return 0;
 143         }
 144
 145         r = parse_time(val, &t, 1);
 146         if (r < 0)
 147                 return r;
 148         if (t == USEC_INFINITY) {
 149                 *ret = RLIM_INFINITY;
 150                 return 0;
 151         }
 152
 153         *ret = (rlim_t) t;
 154         return 0;
 155 }
 156
 157 static int rlimit_parse_nice(const char *val, rlim_t *ret) {
 158         uint64_t rl;
 159         int r;
 160
 161         /* So, Linux is weird. The range for RLIMIT_NICE is 40..1, mapping to the nice levels -20..19. However, the
 162          * RLIMIT_NICE limit defaults to 0 by the kernel, i.e. a value that maps to nice level 20, which of course is
 163          * bogus and does not exist. In order to permit parsing the RLIMIT_NICE of 0 here we hence implement a slight
 164          * asymmetry: when parsing as positive nice level we permit 0..19. When parsing as negative nice level, we
 165          * permit -20..0. But when parsing as raw resource limit value then we also allow the special value 0.
 166          *
 167          * Yeah, Linux is quality engineering sometimes... */
 168
 169         if (val[0] == '+') {
 170
 171                 /* Prefixed with "+": Parse as positive user-friendly nice value */
 172                 r = safe_atou64(val + 1, &rl);
 173                 if (r < 0)
 174                         return r;
 175
 176                 if (rl >= PRIO_MAX)
 177                         return -ERANGE;
 178
 179                 rl = 20 - rl;
 180
 181         } else if (val[0] == '-') {
 182
 183                 /* Prefixed with "-": Parse as negative user-friendly nice value */
 184                 r = safe_atou64(val + 1, &rl);
 185                 if (r < 0)
 186                         return r;
 187
 188                 if (rl > (uint64_t) (-PRIO_MIN))
 189                         return -ERANGE;
 190
 191                 rl = 20 + rl;
 192         } else {
 193
 194                 /* Not prefixed: parse as raw resource limit value */
 195                 r = safe_atou64(val, &rl);
 196                 if (r < 0)
 197                         return r;
 198
 199                 if (rl > (uint64_t) (20 - PRIO_MIN))
 200                         return -ERANGE;
 201         }
 202
 203         *ret = (rlim_t) rl;
 204         return 0;
 205 }
 206
 207 static int (*const rlimit_parse_table[_RLIMIT_MAX])(const char *val, rlim_t *ret) = {
 208         [RLIMIT_CPU] = rlimit_parse_sec,
 209         [RLIMIT_FSIZE] = rlimit_parse_size,
 210         [RLIMIT_DATA] = rlimit_parse_size,
 211         [RLIMIT_STACK] = rlimit_parse_size,
 212         [RLIMIT_CORE] = rlimit_parse_size,
 213         [RLIMIT_RSS] = rlimit_parse_size,
 214         [RLIMIT_NOFILE] = rlimit_parse_u64,
 215         [RLIMIT_AS] = rlimit_parse_size,
 216         [RLIMIT_NPROC] = rlimit_parse_u64,
 217         [RLIMIT_MEMLOCK] = rlimit_parse_size,
 218         [RLIMIT_LOCKS] = rlimit_parse_u64,
 219         [RLIMIT_SIGPENDING] = rlimit_parse_u64,
 220         [RLIMIT_MSGQUEUE] = rlimit_parse_size,
 221         [RLIMIT_NICE] = rlimit_parse_nice,
 222         [RLIMIT_RTPRIO] = rlimit_parse_u64,
 223         [RLIMIT_RTTIME] = rlimit_parse_usec,
 224 };
 225
 226 int rlimit_parse_one(int resource, const char *val, rlim_t *ret) {
 227         assert(val);
 228         assert(ret);
 229
 230         if (resource < 0)
 231                 return -EINVAL;
 232         if (resource >= _RLIMIT_MAX)
 233                 return -EINVAL;
 234
 235         return rlimit_parse_table[resource](val, ret);
 236 }
 237
 238 int rlimit_parse(int resource, const char *val, struct rlimit *ret) {
 239         _cleanup_free_ char *hard = NULL, *soft = NULL;
 240         rlim_t hl, sl;
 241         int r;
 242
 243         assert(val);
 244         assert(ret);
 245
 246         r = extract_first_word(&val, &soft, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
 247         if (r < 0)
 248                 return r;
 249         if (r == 0)
 250                 return -EINVAL;
 251
 252         r = rlimit_parse_one(resource, soft, &sl);
 253         if (r < 0)
 254                 return r;
 255
 256         r = extract_first_word(&val, &hard, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
 257         if (r < 0)
 258                 return r;
 259         if (!isempty(val))
 260                 return -EINVAL;
 261         if (r == 0)
 262                 hl = sl;
 263         else {
 264                 r = rlimit_parse_one(resource, hard, &hl);
 265                 if (r < 0)
 266                         return r;
 267                 if (sl > hl)
 268                         return -EILSEQ;
 269         }
 270
 271         *ret = (struct rlimit) {
 272                 .rlim_cur = sl,
 273                 .rlim_max = hl,
 274         };
 275
 276         return 0;
 277 }
 278
 279 int rlimit_format(const struct rlimit *rl, char **ret) {
 280         char *s = NULL;
 281
 282         assert(rl);
 283         assert(ret);
 284
 285         if (rl->rlim_cur >= RLIM_INFINITY && rl->rlim_max >= RLIM_INFINITY)
 286                 s = strdup("infinity");
 287         else if (rl->rlim_cur >= RLIM_INFINITY)
 288                 (void) asprintf(&s, "infinity:" RLIM_FMT, rl->rlim_max);
 289         else if (rl->rlim_max >= RLIM_INFINITY)
 290                 (void) asprintf(&s, RLIM_FMT ":infinity", rl->rlim_cur);
 291         else if (rl->rlim_cur == rl->rlim_max)
 292                 (void) asprintf(&s, RLIM_FMT, rl->rlim_cur);
 293         else
 294                 (void) asprintf(&s, RLIM_FMT ":" RLIM_FMT, rl->rlim_cur, rl->rlim_max);
 295
 296         if (!s)
 297                 return -ENOMEM;
 298
 299         *ret = s;
 300         return 0;
 301 }
 302
 303 static const char* const rlimit_table[_RLIMIT_MAX] = {
 304         [RLIMIT_CPU] = "LimitCPU",
 305         [RLIMIT_FSIZE] = "LimitFSIZE",
 306         [RLIMIT_DATA] = "LimitDATA",
 307         [RLIMIT_STACK] = "LimitSTACK",
 308         [RLIMIT_CORE] = "LimitCORE",
 309         [RLIMIT_RSS] = "LimitRSS",
 310         [RLIMIT_NOFILE] = "LimitNOFILE",
 311         [RLIMIT_AS] = "LimitAS",
 312         [RLIMIT_NPROC] = "LimitNPROC",
 313         [RLIMIT_MEMLOCK] = "LimitMEMLOCK",
 314         [RLIMIT_LOCKS] = "LimitLOCKS",
 315         [RLIMIT_SIGPENDING] = "LimitSIGPENDING",
 316         [RLIMIT_MSGQUEUE] = "LimitMSGQUEUE",
 317         [RLIMIT_NICE] = "LimitNICE",
 318         [RLIMIT_RTPRIO] = "LimitRTPRIO",
 319         [RLIMIT_RTTIME] = "LimitRTTIME"
 320 };
 321
 322 DEFINE_STRING_TABLE_LOOKUP(rlimit, int);