res/res_limit.c

   1 /*
   2  * Asterisk -- A telephony toolkit for Linux.
   3  *
   4  * Resource limits
   5  *
   6  * Copyright (c) 2006 Tilghman Lesher.  All rights reserved.
   7  *
   8  * Tilghman Lesher <res_limit_200607@the-tilghman.com>
   9  *
  10  * This code is released by the author with no restrictions on usage.
  11  *
  12  */
  13
  14 #include "asterisk.h"
  15
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19 #define _XOPEN_SOURCE 600
  20 #include <string.h>
  21 #include <ctype.h>
  22 #include <sys/time.h>
  23 #include <sys/resource.h>
  24 #include <errno.h>
  25 #include "asterisk/module.h"
  26 #include "asterisk/cli.h"
  27
  28 /* Find proper rlimit for virtual memory */
  29 #ifdef RLIMIT_AS
  30 #define VMEM_DEF RLIMIT_AS
  31 #else
  32 #ifdef RLIMIT_VMEM
  33 #define VMEM_DEF RLIMIT_VMEM
  34 #endif
  35 #endif
  36
  37 static struct limits {
  38         int resource;
  39         char limit[3];
  40         char desc[40];
  41 } limits[] = {
  42         { RLIMIT_CPU, "-t", "cpu time" },
  43         { RLIMIT_FSIZE, "-f", "file size" },
  44         { RLIMIT_DATA, "-d", "program data segment" },
  45         { RLIMIT_STACK, "-s", "program stack size" },
  46         { RLIMIT_CORE, "-c", "core file size" },
  47 #ifdef RLIMIT_RSS
  48         { RLIMIT_RSS, "-m", "resident memory" },
  49         { RLIMIT_NPROC, "-u", "number of processes" },
  50         { RLIMIT_MEMLOCK, "-l", "amount of memory locked into RAM" },
  51 #endif
  52         { RLIMIT_NOFILE, "-n", "number of file descriptors" },
  53 #ifdef VMEM_DEF
  54         { VMEM_DEF, "-v", "virtual memory" },
  55 #endif
  56 };
  57
  58 static int str2limit(const char *string)
  59 {
  60         size_t i;
  61         for (i = 0; i < sizeof(limits) / sizeof(limits[0]); i++) {
  62                 if (!strcasecmp(string, limits[i].limit))
  63                         return limits[i].resource;
  64         }
  65         return -1;
  66 }
  67
  68 static const char *str2desc(const char *string)
  69 {
  70         size_t i;
  71         for (i = 0; i < sizeof(limits) / sizeof(limits[0]); i++) {
  72                 if (!strcmp(string, limits[i].limit))
  73                         return limits[i].desc;
  74         }
  75         return "<unknown>";
  76 }
  77
  78 static int my_ulimit(int fd, int argc, char **argv)
  79 {
  80         int resource;
  81         struct rlimit rlimit = { 0, 0 };
  82         if (argc > 3)
  83                 return RESULT_SHOWUSAGE;
  84
  85         if (argc == 1) {
  86                 char arg2[3];
  87                 char *newargv[2] = { "ulimit", arg2 };
  88                 for (resource = 0; resource < sizeof(limits) / sizeof(limits[0]); resource++) {
  89                         ast_copy_string(arg2, limits[resource].limit, sizeof(arg2));
  90                         my_ulimit(fd, 2, newargv);
  91                 }
  92                 return RESULT_SUCCESS;
  93         } else {
  94                 resource = str2limit(argv[1]);
  95                 if (resource == -1) {
  96                         ast_cli(fd, "Unknown resource\n");
  97                         return RESULT_FAILURE;
  98                 }
  99
 100                 if (argc == 3) {
 101                         int x;
 102                         if (resource != RLIMIT_NOFILE && resource != RLIMIT_CORE && resource != RLIMIT_NPROC && resource != RLIMIT_FSIZE) {
 103                                 ast_cli(fd, "Resource not permitted to be set\n");
 104                                 return RESULT_FAILURE;
 105                         }
 106
 107                         sscanf(argv[2], "%d", &x);
 108                         rlimit.rlim_max = rlimit.rlim_cur = x;
 109                         setrlimit(resource, &rlimit);
 110                         return RESULT_SUCCESS;
 111                 } else {
 112                         if (!getrlimit(resource, &rlimit)) {
 113                                 char printlimit[32];
 114                                 const char *desc;
 115                                 if (rlimit.rlim_max == RLIM_INFINITY)
 116                                         ast_copy_string(printlimit, "effectively unlimited", sizeof(printlimit));
 117                                 else
 118                                         snprintf(printlimit, sizeof(printlimit), "limited to %d", (int)rlimit.rlim_cur);
 119                                 desc = str2desc(argv[1]);
 120                                 ast_cli(fd, "%c%s (%s) is %s.\n", toupper(desc[0]), desc + 1, argv[1], printlimit);
 121                         } else
 122                                 ast_cli(fd, "Could not retrieve resource limits for %s: %s\n", str2desc(argv[1]), strerror(errno));
 123                         return RESULT_SUCCESS;
 124                 }
 125         }
 126 }
 127
 128 static char *complete_ulimit(const char *line, const char *word, int pos, int state)
 129 {
 130         int which = 0, i;
 131         int wordlen = strlen(word);
 132
 133         if (pos > 2)
 134                 return NULL;
 135         for (i = 0; i < sizeof(limits) / sizeof(limits[0]); i++) {
 136                 if (!strncasecmp(limits[i].limit, word, wordlen)) {
 137                         if (++which > state)
 138                                 return ast_strdup(limits[i].limit);
 139                 }
 140         }
 141         return NULL;
 142 }
 143
 144 static const char ulimit_usage[] =
 145 "Usage: ulimit {-d|-l|-f|-m|-s|-t|-u|-v|-c|-n} [<num>]\n"
 146 "       Shows or sets the corresponding resource limit.\n"
 147 "         -d  Process data segment [readonly]\n"
 148 "         -l  Memory lock size [readonly]\n"
 149 "         -f  File size\n"
 150 "         -m  Process resident memory [readonly]\n"
 151 "         -s  Process stack size [readonly]\n"
 152 "         -t  CPU usage [readonly]\n"
 153 "         -u  Child processes\n"
 154 #ifdef VMEM_DEF
 155 "         -v  Process virtual memory [readonly]\n"
 156 #endif
 157 "         -c  Core dump file size\n"
 158 "         -n  Number of file descriptors\n";
 159
 160 static struct ast_cli_entry cli_ulimit = {
 161         { "ulimit", NULL }, my_ulimit,
 162         "Set or show process resource limits", ulimit_usage, complete_ulimit };
 163
 164 static int unload_module(void)
 165 {
 166         return ast_cli_unregister(&cli_ulimit);
 167 }
 168
 169 static int load_module(void)
 170 {
 171         return ast_cli_register(&cli_ulimit)? AST_MODULE_LOAD_FAILURE: AST_MODULE_LOAD_SUCCESS;
 172 }
 173
 174 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Resource limits");
 175