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 //config:config IPCRM
  11 //config:       bool "ipcrm (2.9 kb)"
  12 //config:       default y
  13 //config:       help
  14 //config:       The ipcrm utility allows the removal of System V interprocess
  15 //config:       communication (IPC) objects and the associated data structures
  16 //config:       from the system.
  17
  18 //applet:IF_IPCRM(APPLET_NOEXEC(ipcrm, ipcrm, BB_DIR_USR_BIN, BB_SUID_DROP, ipcrm))
  19
  20 //kbuild:lib-$(CONFIG_IPCRM) += ipcrm.o
  21
  22 #include "libbb.h"
  23
  24 /* X/OPEN tells us to use <sys/{types,ipc,sem}.h> for semctl() */
  25 /* X/OPEN tells us to use <sys/{types,ipc,msg}.h> for msgctl() */
  26 #include <sys/ipc.h>
  27 #include <sys/shm.h>
  28 #include <sys/msg.h>
  29 #include <sys/sem.h>
  30
  31 #if defined(__GNU_LIBRARY__) && !defined(_SEM_SEMUN_UNDEFINED)
  32 /* union semun is defined by including <sys/sem.h> */
  33 #else
  34 /* according to X/OPEN we have to define it ourselves */
  35 union semun {
  36         int val;
  37         struct semid_ds *buf;
  38         unsigned short *array;
  39         struct seminfo *__buf;
  40 };
  41 #endif
  42
  43 #define IPCRM_LEGACY 1
  44
  45
  46 #if IPCRM_LEGACY
  47
  48 typedef enum type_id {
  49         SHM,
  50         SEM,
  51         MSG
  52 } type_id;
  53
  54 static int remove_ids(type_id type, char **argv)
  55 {
  56         unsigned long id;
  57         int nb_errors = 0;
  58         union semun arg;
  59
  60         arg.val = 0;
  61
  62         while (argv[0]) {
  63                 id = bb_strtoul(argv[0], NULL, 10);
  64                 if (errno || id > INT_MAX) {
  65                         bb_error_msg("invalid id: %s", argv[0]);
  66                         nb_errors++;
  67                 } else {
  68                         int ret = 0;
  69                         if (type == SEM)
  70                                 ret = semctl(id, 0, IPC_RMID, arg);
  71                         else if (type == MSG)
  72                                 ret = msgctl(id, IPC_RMID, NULL);
  73                         else if (type ==  SHM)
  74                                 ret = shmctl(id, IPC_RMID, NULL);
  75
  76                         if (ret) {
  77                                 bb_perror_msg("can't remove id %s", argv[0]);
  78                                 nb_errors++;
  79                         }
  80                 }
  81                 argv++;
  82         }
  83
  84         return nb_errors;
  85 }
  86 #endif /* IPCRM_LEGACY */
  87
  88 //usage:#define ipcrm_trivial_usage
  89 //usage:       "[-MQS key] [-mqs id]"
  90 //usage:#define ipcrm_full_usage "\n\n"
  91 //usage:       "Upper-case options MQS remove an object by shmkey value.\n"
  92 //usage:       "Lower-case options remove an object by shmid value.\n"
  93 //usage:     "\n        -mM     Remove memory segment after last detach"
  94 //usage:     "\n        -qQ     Remove message queue"
  95 //usage:     "\n        -sS     Remove semaphore"
  96
  97 int ipcrm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  98 int ipcrm_main(int argc, char **argv)
  99 {
 100         int c;
 101         int error = 0;
 102
 103         /* if the command is executed without parameters, do nothing */
 104         if (argc == 1)
 105                 return 0;
 106 #if IPCRM_LEGACY
 107         /* check to see if the command is being invoked in the old way if so
 108            then run the old code. Valid commands are msg, shm, sem. */
 109         {
 110                 type_id what = 0; /* silence gcc */
 111                 char w;
 112
 113                 w = argv[1][0];
 114                 if ( ((w == 'm' && argv[1][1] == 's' && argv[1][2] == 'g')
 115                        || (argv[1][0] == 's'
 116                            && ((w = argv[1][1]) == 'h' || w == 'e')
 117                            && argv[1][2] == 'm')
 118                      ) && argv[1][3] == '\0'
 119                 ) {
 120                         if (argc < 3)
 121                                 bb_show_usage();
 122
 123                         if (w == 'h')
 124                                 what = SHM;
 125                         else if (w == 'm')
 126                                 what = MSG;
 127                         else if (w == 'e')
 128                                 what = SEM;
 129
 130                         if (remove_ids(what, &argv[2]))
 131                                 fflush_stdout_and_exit(EXIT_FAILURE);
 132                         puts("resource(s) deleted");
 133                         return 0;
 134                 }
 135         }
 136 #endif /* IPCRM_LEGACY */
 137
 138         /* process new syntax to conform with SYSV ipcrm */
 139         while ((c = getopt(argc, argv, "q:m:s:Q:M:S:")) != -1) {
 140                 int result;
 141                 int id;
 142                 int iskey;
 143                 /* needed to delete semaphores */
 144                 union semun arg;
 145
 146                 if (c == '?') /* option not in the string */
 147                         bb_show_usage();
 148
 149                 id = 0;
 150                 arg.val = 0;
 151
 152                 iskey = !(c & 0x20); /* uppercase? */
 153                 if (iskey) {
 154                         /* keys are in hex or decimal */
 155                         key_t key = xstrtoul(optarg, 0);
 156
 157                         if (key == IPC_PRIVATE) {
 158                                 error++;
 159                                 bb_error_msg("illegal key (%s)", optarg);
 160                                 continue;
 161                         }
 162
 163                         c |= 0x20; /* lowercase. c is 'q', 'm' or 's' now */
 164                         /* convert key to id */
 165                         id = ((c == 'q') ? msgget(key, 0) :
 166                                 (c == 'm') ? shmget(key, 0, 0) : semget(key, 0, 0));
 167
 168                         if (id < 0) {
 169                                 const char *errmsg;
 170
 171                                 error++;
 172                                 switch (errno) {
 173                                 case EACCES:
 174                                         errmsg = "permission denied for";
 175                                         break;
 176                                 case EIDRM:
 177                                         errmsg = "already removed";
 178                                         break;
 179                                 case ENOENT:
 180                                         errmsg = "invalid";
 181                                         break;
 182                                 default:
 183                                         errmsg = "unknown error in";
 184                                         break;
 185                                 }
 186                                 bb_error_msg("%s %s (%s)", errmsg, "key", optarg);
 187                                 continue;
 188                         }
 189                 } else {
 190                         /* ids are in decimal */
 191                         id = xatoul(optarg);
 192                 }
 193
 194                 result = ((c == 'q') ? msgctl(id, IPC_RMID, NULL) :
 195                                 (c == 'm') ? shmctl(id, IPC_RMID, NULL) :
 196                                 semctl(id, 0, IPC_RMID, arg));
 197
 198                 if (result) {
 199                         const char *errmsg;
 200                         const char *const what = iskey ? "key" : "id";
 201
 202                         error++;
 203                         switch (errno) {
 204                         case EACCES:
 205                         case EPERM:
 206                                 errmsg = "permission denied for";
 207                                 break;
 208                         case EINVAL:
 209                                 errmsg = "invalid";
 210                                 break;
 211                         case EIDRM:
 212                                 errmsg = "already removed";
 213                                 break;
 214                         default:
 215                                 errmsg = "unknown error in";
 216                                 break;
 217                         }
 218                         bb_error_msg("%s %s (%s)", errmsg, what, optarg);
 219                         continue;
 220                 }
 221         }
 222
 223         /* print usage if we still have some arguments left over */
 224         if (optind != argc) {
 225                 bb_show_usage();
 226         }
 227
 228         /* exit value reflects the number of errors encountered */
 229         return error;
 230 }