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:     "\nOptions:"
  17 //usage:     "\n        -mM     Remove memory segment after last detach"
  18 //usage:     "\n        -qQ     Remove message queue"
  19 //usage:     "\n        -sS     Remove semaphore"
  20
  21 #include "libbb.h"
  22
  23 /* X/OPEN tells us to use <sys/{types,ipc,sem}.h> for semctl() */
  24 /* X/OPEN tells us to use <sys/{types,ipc,msg}.h> for msgctl() */
  25 #include <sys/ipc.h>
  26 #include <sys/shm.h>
  27 #include <sys/msg.h>
  28 #include <sys/sem.h>
  29
  30 #if defined(__GNU_LIBRARY__) && !defined(_SEM_SEMUN_UNDEFINED)
  31 /* union semun is defined by including <sys/sem.h> */
  32 #else
  33 /* according to X/OPEN we have to define it ourselves */
  34 union semun {
  35         int val;
  36         struct semid_ds *buf;
  37         unsigned short *array;
  38         struct seminfo *__buf;
  39 };
  40 #endif
  41
  42 #define IPCRM_LEGACY 1
  43
  44
  45 #if IPCRM_LEGACY
  46
  47 typedef enum type_id {
  48         SHM,
  49         SEM,
  50         MSG
  51 } type_id;
  52
  53 static int remove_ids(type_id type, char **argv)
  54 {
  55         unsigned long id;
  56         int nb_errors = 0;
  57         union semun arg;
  58
  59         arg.val = 0;
  60
  61         while (argv[0]) {
  62                 id = bb_strtoul(argv[0], NULL, 10);
  63                 if (errno || id > INT_MAX) {
  64                         bb_error_msg("invalid id: %s", argv[0]);
  65                         nb_errors++;
  66                 } else {
  67                         int ret = 0;
  68                         if (type == SEM)
  69                                 ret = semctl(id, 0, IPC_RMID, arg);
  70                         else if (type == MSG)
  71                                 ret = msgctl(id, IPC_RMID, NULL);
  72                         else if (type ==  SHM)
  73                                 ret = shmctl(id, IPC_RMID, NULL);
  74
  75                         if (ret) {
  76                                 bb_perror_msg("can't remove id %s", argv[0]);
  77                                 nb_errors++;
  78                         }
  79                 }
  80                 argv++;
  81         }
  82
  83         return nb_errors;
  84 }
  85 #endif /* IPCRM_LEGACY */
  86
  87
  88 int ipcrm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  89 int ipcrm_main(int argc, char **argv)
  90 {
  91         int c;
  92         int error = 0;
  93
  94         /* if the command is executed without parameters, do nothing */
  95         if (argc == 1)
  96                 return 0;
  97 #if IPCRM_LEGACY
  98         /* check to see if the command is being invoked in the old way if so
  99            then run the old code. Valid commands are msg, shm, sem. */
 100         {
 101                 type_id what = 0; /* silence gcc */
 102                 char w;
 103
 104                 w = argv[1][0];
 105                 if ( ((w == 'm' && argv[1][1] == 's' && argv[1][2] == 'g')
 106                        || (argv[1][0] == 's'
 107                            && ((w = argv[1][1]) == 'h' || w == 'e')
 108                            && argv[1][2] == 'm')
 109                      ) && argv[1][3] == '\0'
 110                 ) {
 111                         if (argc < 3)
 112                                 bb_show_usage();
 113
 114                         if (w == 'h')
 115                                 what = SHM;
 116                         else if (w == 'm')
 117                                 what = MSG;
 118                         else if (w == 'e')
 119                                 what = SEM;
 120
 121                         if (remove_ids(what, &argv[2]))
 122                                 fflush_stdout_and_exit(EXIT_FAILURE);
 123                         printf("resource(s) deleted\n");
 124                         return 0;
 125                 }
 126         }
 127 #endif /* IPCRM_LEGACY */
 128
 129         /* process new syntax to conform with SYSV ipcrm */
 130         while ((c = getopt(argc, argv, "q:m:s:Q:M:S:h?")) != -1) {
 131                 int result;
 132                 int id = 0;
 133                 int iskey = isupper(c);
 134
 135                 /* needed to delete semaphores */
 136                 union semun arg;
 137
 138                 arg.val = 0;
 139
 140                 if ((c == '?') || (c == 'h')) {
 141                         bb_show_usage();
 142                 }
 143
 144                 /* we don't need case information any more */
 145                 c = tolower(c);
 146
 147                 /* make sure the option is in range: allowed are q, m, s */
 148                 if (c != 'q' && c != 'm' && c != 's') {
 149                         bb_show_usage();
 150                 }
 151
 152                 if (iskey) {
 153                         /* keys are in hex or decimal */
 154                         key_t key = xstrtoul(optarg, 0);
 155
 156                         if (key == IPC_PRIVATE) {
 157                                 error++;
 158                                 bb_error_msg("illegal key (%s)", optarg);
 159                                 continue;
 160                         }
 161
 162                         /* convert key to id */
 163                         id = ((c == 'q') ? msgget(key, 0) :
 164                                   (c == 'm') ? shmget(key, 0, 0) : semget(key, 0, 0));
 165
 166                         if (id < 0) {
 167                                 const char *errmsg;
 168
 169                                 error++;
 170                                 switch (errno) {
 171                                 case EACCES:
 172                                         errmsg = "permission denied for";
 173                                         break;
 174                                 case EIDRM:
 175                                         errmsg = "already removed";
 176                                         break;
 177                                 case ENOENT:
 178                                         errmsg = "invalid";
 179                                         break;
 180                                 default:
 181                                         errmsg = "unknown error in";
 182                                         break;
 183                                 }
 184                                 bb_error_msg("%s %s (%s)", errmsg, "key", optarg);
 185                                 continue;
 186                         }
 187                 } else {
 188                         /* ids are in decimal */
 189                         id = xatoul(optarg);
 190                 }
 191
 192                 result = ((c == 'q') ? msgctl(id, IPC_RMID, NULL) :
 193                                   (c == 'm') ? shmctl(id, IPC_RMID, NULL) :
 194                                   semctl(id, 0, IPC_RMID, arg));
 195
 196                 if (result) {
 197                         const char *errmsg;
 198                         const char *const what = iskey ? "key" : "id";
 199
 200                         error++;
 201                         switch (errno) {
 202                         case EACCES:
 203                         case EPERM:
 204                                 errmsg = "permission denied for";
 205                                 break;
 206                         case EINVAL:
 207                                 errmsg = "invalid";
 208                                 break;
 209                         case EIDRM:
 210                                 errmsg = "already removed";
 211                                 break;
 212                         default:
 213                                 errmsg = "unknown error in";
 214                                 break;
 215                         }
 216                         bb_error_msg("%s %s (%s)", errmsg, what, optarg);
 217                         continue;
 218                 }
 219         }
 220
 221         /* print usage if we still have some arguments left over */
 222         if (optind != argc) {
 223                 bb_show_usage();
 224         }
 225
 226         /* exit value reflects the number of errors encountered */
 227         return error;
 228 }