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 "formats-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         assert_se(getrlimit(resource, &highest) == 0);
  46
  47         fixed.rlim_cur = MIN(rlim->rlim_cur, highest.rlim_max);
  48         fixed.rlim_max = MIN(rlim->rlim_max, highest.rlim_max);
  49
  50         if (setrlimit(resource, &fixed) < 0)
  51                 return -errno;
  52
  53         return 0;
  54 }
  55
  56 static int rlimit_parse_u64(const char *val, rlim_t *ret) {
  57         uint64_t u;
  58         int r;
  59
  60         assert(val);
  61         assert(ret);
  62
  63         if (streq(val, "infinity")) {
  64                 *ret = RLIM_INFINITY;
  65                 return 0;
  66         }
  67
  68         /* setrlimit(2) suggests rlim_t is always 64bit on Linux. */
  69         assert_cc(sizeof(rlim_t) == sizeof(uint64_t));
  70
  71         r = safe_atou64(val, &u);
  72         if (r < 0)
  73                 return r;
  74         if (u >= (uint64_t) RLIM_INFINITY)
  75                 return -ERANGE;
  76
  77         *ret = (rlim_t) u;
  78         return 0;
  79 }
  80
  81 static int rlimit_parse_size(const char *val, rlim_t *ret) {
  82         uint64_t u;
  83         int r;
  84
  85         assert(val);
  86         assert(ret);
  87
  88         if (streq(val, "infinity")) {
  89                 *ret = RLIM_INFINITY;
  90                 return 0;
  91         }
  92
  93         r = parse_size(val, 1024, &u);
  94         if (r < 0)
  95                 return r;
  96         if (u >= (uint64_t) RLIM_INFINITY)
  97                 return -ERANGE;
  98
  99         *ret = (rlim_t) u;
 100         return 0;
 101 }
 102
 103 static int rlimit_parse_sec(const char *val, rlim_t *ret) {
 104         uint64_t u;
 105         usec_t t;
 106         int r;
 107
 108         assert(val);
 109         assert(ret);
 110
 111         if (streq(val, "infinity")) {
 112                 *ret = RLIM_INFINITY;
 113                 return 0;
 114         }
 115
 116         r = parse_sec(val, &t);
 117         if (r < 0)
 118                 return r;
 119         if (t == USEC_INFINITY) {
 120                 *ret = RLIM_INFINITY;
 121                 return 0;
 122         }
 123
 124         u = (uint64_t) DIV_ROUND_UP(t, USEC_PER_SEC);
 125         if (u >= (uint64_t) RLIM_INFINITY)
 126                 return -ERANGE;
 127
 128         *ret = (rlim_t) u;
 129         return 0;
 130 }
 131
 132 static int rlimit_parse_usec(const char *val, rlim_t *ret) {
 133         usec_t t;
 134         int r;
 135
 136         assert(val);
 137         assert(ret);
 138
 139         if (streq(val, "infinity")) {
 140                 *ret = RLIM_INFINITY;
 141                 return 0;
 142         }
 143
 144         r = parse_time(val, &t, 1);
 145         if (r < 0)
 146                 return r;
 147         if (t == USEC_INFINITY) {
 148                 *ret = RLIM_INFINITY;
 149                 return 0;
 150         }
 151
 152         *ret = (rlim_t) t;
 153         return 0;
 154 }
 155
 156 static int rlimit_parse_nice(const char *val, rlim_t *ret) {
 157         uint64_t rl;
 158         int r;
 159
 160         /* So, Linux is weird. The range for RLIMIT_NICE is 40..1, mapping to the nice levels -20..19. However, the
 161          * RLIMIT_NICE limit defaults to 0 by the kernel, i.e. a value that maps to nice level 20, which of course is
 162          * bogus and does not exist. In order to permit parsing the RLIMIT_NICE of 0 here we hence implement a slight
 163          * asymmetry: when parsing as positive nice level we permit 0..19. When parsing as negative nice level, we
 164          * permit -20..0. But when parsing as raw resource limit value then we also allow the special value 0.
 165          *
 166          * Yeah, Linux is quality engineering sometimes... */
 167
 168         if (val[0] == '+') {
 169
 170                 /* Prefixed with "+": Parse as positive user-friendly nice value */
 171                 r = safe_atou64(val + 1, &rl);
 172                 if (r < 0)
 173                         return r;
 174
 175                 if (rl >= PRIO_MAX)
 176                         return -ERANGE;
 177
 178                 rl = 20 - rl;
 179
 180         } else if (val[0] == '-') {
 181
 182                 /* Prefixed with "-": Parse as negative user-friendly nice value */
 183                 r = safe_atou64(val + 1, &rl);
 184                 if (r < 0)
 185                         return r;
 186
 187                 if (rl > (uint64_t) (-PRIO_MIN))
 188                         return -ERANGE;
 189
 190                 rl = 20 + rl;
 191         } else {
 192
 193                 /* Not prefixed: parse as raw resource limit value */
 194                 r = safe_atou64(val, &rl);
 195                 if (r < 0)
 196                         return r;
 197
 198                 if (rl > (uint64_t) (20 - PRIO_MIN))
 199                         return -ERANGE;
 200         }
 201
 202         *ret = (rlim_t) rl;
 203         return 0;
 204 }
 205
 206 static int (*const rlimit_parse_table[_RLIMIT_MAX])(const char *val, rlim_t *ret) = {
 207         [RLIMIT_CPU] = rlimit_parse_sec,
 208         [RLIMIT_FSIZE] = rlimit_parse_size,
 209         [RLIMIT_DATA] = rlimit_parse_size,
 210         [RLIMIT_STACK] = rlimit_parse_size,
 211         [RLIMIT_CORE] = rlimit_parse_size,
 212         [RLIMIT_RSS] = rlimit_parse_size,
 213         [RLIMIT_NOFILE] = rlimit_parse_u64,
 214         [RLIMIT_AS] = rlimit_parse_size,
 215         [RLIMIT_NPROC] = rlimit_parse_u64,
 216         [RLIMIT_MEMLOCK] = rlimit_parse_size,
 217         [RLIMIT_LOCKS] = rlimit_parse_u64,
 218         [RLIMIT_SIGPENDING] = rlimit_parse_u64,
 219         [RLIMIT_MSGQUEUE] = rlimit_parse_size,
 220         [RLIMIT_NICE] = rlimit_parse_nice,
 221         [RLIMIT_RTPRIO] = rlimit_parse_u64,
 222         [RLIMIT_RTTIME] = rlimit_parse_usec,
 223 };
 224
 225 int rlimit_parse_one(int resource, const char *val, rlim_t *ret) {
 226         assert(val);
 227         assert(ret);
 228
 229         if (resource < 0)
 230                 return -EINVAL;
 231         if (resource >= _RLIMIT_MAX)
 232                 return -EINVAL;
 233
 234         return rlimit_parse_table[resource](val, ret);
 235 }
 236
 237 int rlimit_parse(int resource, const char *val, struct rlimit *ret) {
 238         _cleanup_free_ char *hard = NULL, *soft = NULL;
 239         rlim_t hl, sl;
 240         int r;
 241
 242         assert(val);
 243         assert(ret);
 244
 245         r = extract_first_word(&val, &soft, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
 246         if (r < 0)
 247                 return r;
 248         if (r == 0)
 249                 return -EINVAL;
 250
 251         r = rlimit_parse_one(resource, soft, &sl);
 252         if (r < 0)
 253                 return r;
 254
 255         r = extract_first_word(&val, &hard, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
 256         if (r < 0)
 257                 return r;
 258         if (!isempty(val))
 259                 return -EINVAL;
 260         if (r == 0)
 261                 hl = sl;
 262         else {
 263                 r = rlimit_parse_one(resource, hard, &hl);
 264                 if (r < 0)
 265                         return r;
 266                 if (sl > hl)
 267                         return -EILSEQ;
 268         }
 269
 270         *ret = (struct rlimit) {
 271                 .rlim_cur = sl,
 272                 .rlim_max = hl,
 273         };
 274
 275         return 0;
 276 }
 277
 278 int rlimit_format(const struct rlimit *rl, char **ret) {
 279         char *s = NULL;
 280
 281         assert(rl);
 282         assert(ret);
 283
 284         if (rl->rlim_cur >= RLIM_INFINITY && rl->rlim_max >= RLIM_INFINITY)
 285                 s = strdup("infinity");
 286         else if (rl->rlim_cur >= RLIM_INFINITY)
 287                 (void) asprintf(&s, "infinity:" RLIM_FMT, rl->rlim_max);
 288         else if (rl->rlim_max >= RLIM_INFINITY)
 289                 (void) asprintf(&s, RLIM_FMT ":infinity", rl->rlim_cur);
 290         else if (rl->rlim_cur == rl->rlim_max)
 291                 (void) asprintf(&s, RLIM_FMT, rl->rlim_cur);
 292         else
 293                 (void) asprintf(&s, RLIM_FMT ":" RLIM_FMT, rl->rlim_cur, rl->rlim_max);
 294
 295         if (!s)
 296                 return -ENOMEM;
 297
 298         *ret = s;
 299         return 0;
 300 }
 301
 302 static const char* const rlimit_table[_RLIMIT_MAX] = {
 303         [RLIMIT_CPU] = "LimitCPU",
 304         [RLIMIT_FSIZE] = "LimitFSIZE",
 305         [RLIMIT_DATA] = "LimitDATA",
 306         [RLIMIT_STACK] = "LimitSTACK",
 307         [RLIMIT_CORE] = "LimitCORE",
 308         [RLIMIT_RSS] = "LimitRSS",
 309         [RLIMIT_NOFILE] = "LimitNOFILE",
 310         [RLIMIT_AS] = "LimitAS",
 311         [RLIMIT_NPROC] = "LimitNPROC",
 312         [RLIMIT_MEMLOCK] = "LimitMEMLOCK",
 313         [RLIMIT_LOCKS] = "LimitLOCKS",
 314         [RLIMIT_SIGPENDING] = "LimitSIGPENDING",
 315         [RLIMIT_MSGQUEUE] = "LimitMSGQUEUE",
 316         [RLIMIT_NICE] = "LimitNICE",
 317         [RLIMIT_RTPRIO] = "LimitRTPRIO",
 318         [RLIMIT_RTTIME] = "LimitRTTIME"
 319 };
 320
 321 DEFINE_STRING_TABLE_LOOKUP(rlimit, int);