util-linux/ipcrm.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * ipcrm.c - utility to allow removal of IPC objects and data structures.
   4  *
   5  * 01 Sept 2004 - Rodney Radford <rradford@mindspring.com>
   6  * Adapted for busybox from util-linux-2.12a.
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9  */
  10
  11 //usage:#define ipcrm_trivial_usage
  12 //usage:       "[-MQS key] [-mqs id]"
  13 //usage:#define ipcrm_full_usage "\n\n"
  14 //usage:       "Upper-case options MQS remove an object by shmkey value.\n"
  15 //usage:       "Lower-case options remove an object by shmid value.\n"
  16 //usage:     "\n        -mM     Remove memory segment after last detach"
  17 //usage:     "\n        -qQ     Remove message queue"
  18 //usage:     "\n        -sS     Remove semaphore"
  19
  20 #include "libbb.h"
  21
  22 /* X/OPEN tells us to use <sys/{types,ipc,sem}.h> for semctl() */
  23 /* X/OPEN tells us to use <sys/{types,ipc,msg}.h> for msgctl() */
  24 #include <sys/ipc.h>
  25 #include <sys/shm.h>
  26 #include <sys/msg.h>
  27 #include <sys/sem.h>
  28
  29 #if defined(__GNU_LIBRARY__) && !defined(_SEM_SEMUN_UNDEFINED)
  30 /* union semun is defined by including <sys/sem.h> */
  31 #else
  32 /* according to X/OPEN we have to define it ourselves */
  33 union semun {
  34         int val;
  35         struct semid_ds *buf;
  36         unsigned short *array;
  37         struct seminfo *__buf;
  38 };
  39 #endif
  40
  41 #define IPCRM_LEGACY 1
  42
  43
  44 #if IPCRM_LEGACY
  45
  46 typedef enum type_id {
  47         SHM,
  48         SEM,
  49         MSG
  50 } type_id;
  51
  52 static int remove_ids(type_id type, char **argv)
  53 {
  54         unsigned long id;
  55         int nb_errors = 0;
  56         union semun arg;
  57
  58         arg.val = 0;
  59
  60         while (argv[0]) {
  61                 id = bb_strtoul(argv[0], NULL, 10);
  62                 if (errno || id > INT_MAX) {
  63                         bb_error_msg("invalid id: %s", argv[0]);
  64                         nb_errors++;
  65                 } else {
  66                         int ret = 0;
  67                         if (type == SEM)
  68                                 ret = semctl(id, 0, IPC_RMID, arg);
  69                         else if (type == MSG)
  70                                 ret = msgctl(id, IPC_RMID, NULL);
  71                         else if (type ==  SHM)
  72                                 ret = shmctl(id, IPC_RMID, NULL);
  73
  74                         if (ret) {
  75                                 bb_perror_msg("can't remove id %s", argv[0]);
  76                                 nb_errors++;
  77                         }
  78                 }
  79                 argv++;
  80         }
  81
  82         return nb_errors;
  83 }
  84 #endif /* IPCRM_LEGACY */
  85
  86
  87 int ipcrm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  88 int ipcrm_main(int argc, char **argv)
  89 {
  90         int c;
  91         int error = 0;
  92
  93         /* if the command is executed without parameters, do nothing */
  94         if (argc == 1)
  95                 return 0;
  96 #if IPCRM_LEGACY
  97         /* check to see if the command is being invoked in the old way if so
  98            then run the old code. Valid commands are msg, shm, sem. */
  99         {
 100                 type_id what = 0; /* silence gcc */
 101                 char w;
 102
 103                 w = argv[1][0];
 104                 if ( ((w == 'm' && argv[1][1] == 's' && argv[1][2] == 'g')
 105                        || (argv[1][0] == 's'
 106                            && ((w = argv[1][1]) == 'h' || w == 'e')
 107                            && argv[1][2] == 'm')
 108                      ) && argv[1][3] == '\0'
 109                 ) {
 110                         if (argc < 3)
 111                                 bb_show_usage();
 112
 113                         if (w == 'h')
 114                                 what = SHM;
 115                         else if (w == 'm')
 116                                 what = MSG;
 117                         else if (w == 'e')
 118                                 what = SEM;
 119
 120                         if (remove_ids(what, &argv[2]))
 121                                 fflush_stdout_and_exit(EXIT_FAILURE);
 122                         printf("resource(s) deleted\n");
 123                         return 0;
 124                 }
 125         }
 126 #endif /* IPCRM_LEGACY */
 127
 128         /* process new syntax to conform with SYSV ipcrm */
 129         while ((c = getopt(argc, argv, "q:m:s:Q:M:S:h?")) != -1) {
 130                 int result;
 131                 int id = 0;
 132                 int iskey = isupper(c);
 133
 134                 /* needed to delete semaphores */
 135                 union semun arg;
 136
 137                 arg.val = 0;
 138
 139                 if ((c == '?') || (c == 'h')) {
 140                         bb_show_usage();
 141                 }
 142
 143                 /* we don't need case information any more */
 144                 c = tolower(c);
 145
 146                 /* make sure the option is in range: allowed are q, m, s */
 147                 if (c != 'q' && c != 'm' && c != 's') {
 148                         bb_show_usage();
 149                 }
 150
 151                 if (iskey) {
 152                         /* keys are in hex or decimal */
 153                         key_t key = xstrtoul(optarg, 0);
 154
 155                         if (key == IPC_PRIVATE) {
 156                                 error++;
 157                                 bb_error_msg("illegal key (%s)", optarg);
 158                                 continue;
 159                         }
 160
 161                         /* convert key to id */
 162                         id = ((c == 'q') ? msgget(key, 0) :
 163                                 (c == 'm') ? shmget(key, 0, 0) : semget(key, 0, 0));
 164
 165                         if (id < 0) {
 166                                 const char *errmsg;
 167
 168                                 error++;
 169                                 switch (errno) {
 170                                 case EACCES:
 171                                         errmsg = "permission denied for";
 172                                         break;
 173                                 case EIDRM:
 174                                         errmsg = "already removed";
 175                                         break;
 176                                 case ENOENT:
 177                                         errmsg = "invalid";
 178                                         break;
 179                                 default:
 180                                         errmsg = "unknown error in";
 181                                         break;
 182                                 }
 183                                 bb_error_msg("%s %s (%s)", errmsg, "key", optarg);
 184                                 continue;
 185                         }
 186                 } else {
 187                         /* ids are in decimal */
 188                         id = xatoul(optarg);
 189                 }
 190
 191                 result = ((c == 'q') ? msgctl(id, IPC_RMID, NULL) :
 192                                 (c == 'm') ? shmctl(id, IPC_RMID, NULL) :
 193                                 semctl(id, 0, IPC_RMID, arg));
 194
 195                 if (result) {
 196                         const char *errmsg;
 197                         const char *const what = iskey ? "key" : "id";
 198
 199                         error++;
 200                         switch (errno) {
 201                         case EACCES:
 202                         case EPERM:
 203                                 errmsg = "permission denied for";
 204                                 break;
 205                         case EINVAL:
 206                                 errmsg = "invalid";
 207                                 break;
 208                         case EIDRM:
 209                                 errmsg = "already removed";
 210                                 break;
 211                         default:
 212                                 errmsg = "unknown error in";
 213                                 break;
 214                         }
 215                         bb_error_msg("%s %s (%s)", errmsg, what, optarg);
 216                         continue;
 217                 }
 218         }
 219
 220         /* print usage if we still have some arguments left over */
 221         if (optind != argc) {
 222                 bb_show_usage();
 223         }
 224
 225         /* exit value reflects the number of errors encountered */
 226         return error;
 227 }