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