source: MondoRescue/branches/3.2/mindi-busybox/util-linux/ipcrm.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * ipcrm.c - utility to allow removal of IPC objects and data structures.
 *
 * 01 Sept 2004 - Rodney Radford <rradford@mindspring.com>
 * Adapted for busybox from util-linux-2.12a.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//usage:#define ipcrm_trivial_usage
//usage:       "[-MQS key] [-mqs id]"
//usage:#define ipcrm_full_usage "\n\n"
//usage:       "Upper-case options MQS remove an object by shmkey value.\n"
//usage:       "Lower-case options remove an object by shmid value.\n"
//usage:     "\n    -mM Remove memory segment after last detach"
//usage:     "\n    -qQ Remove message queue"
//usage:     "\n    -sS Remove semaphore"

#include "libbb.h"

/* X/OPEN tells us to use <sys/{types,ipc,sem}.h> for semctl() */
/* X/OPEN tells us to use <sys/{types,ipc,msg}.h> for msgctl() */
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/msg.h>
#include <sys/sem.h>

#if defined(__GNU_LIBRARY__) && !defined(_SEM_SEMUN_UNDEFINED)
/* union semun is defined by including <sys/sem.h> */
#else
/* according to X/OPEN we have to define it ourselves */
union semun {
    int val;
    struct semid_ds *buf;
    unsigned short *array;
    struct seminfo *__buf;
};
#endif

#define IPCRM_LEGACY 1


#if IPCRM_LEGACY

typedef enum type_id {
    SHM,
    SEM,
    MSG
} type_id;

static int remove_ids(type_id type, char **argv)
{
    unsigned long id;
    int nb_errors = 0;
    union semun arg;

    arg.val = 0;

    while (argv[0]) {
        id = bb_strtoul(argv[0], NULL, 10);
        if (errno || id > INT_MAX) {
            bb_error_msg("invalid id: %s", argv[0]);
            nb_errors++;
        } else {
            int ret = 0;
            if (type == SEM)
                ret = semctl(id, 0, IPC_RMID, arg);
            else if (type == MSG)
                ret = msgctl(id, IPC_RMID, NULL);
            else if (type ==  SHM)
                ret = shmctl(id, IPC_RMID, NULL);

            if (ret) {
                bb_perror_msg("can't remove id %s", argv[0]);
                nb_errors++;
            }
        }
        argv++;
    }

    return nb_errors;
}
#endif /* IPCRM_LEGACY */


int ipcrm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ipcrm_main(int argc, char **argv)
{
    int c;
    int error = 0;

    /* if the command is executed without parameters, do nothing */
    if (argc == 1)
        return 0;
#if IPCRM_LEGACY
    /* check to see if the command is being invoked in the old way if so
       then run the old code. Valid commands are msg, shm, sem. */
    {
        type_id what = 0; /* silence gcc */
        char w;

        w = argv[1][0];
        if ( ((w == 'm' && argv[1][1] == 's' && argv[1][2] == 'g')
               || (argv[1][0] == 's'
                   && ((w = argv[1][1]) == 'h' || w == 'e')
                   && argv[1][2] == 'm')
             ) && argv[1][3] == '\0'
        ) {
            if (argc < 3)
                bb_show_usage();

            if (w == 'h')
                what = SHM;
            else if (w == 'm')
                what = MSG;
            else if (w == 'e')
                what = SEM;

            if (remove_ids(what, &argv[2]))
                fflush_stdout_and_exit(EXIT_FAILURE);
            printf("resource(s) deleted\n");
            return 0;
        }
    }
#endif /* IPCRM_LEGACY */

    /* process new syntax to conform with SYSV ipcrm */
    while ((c = getopt(argc, argv, "q:m:s:Q:M:S:h?")) != -1) {
        int result;
        int id = 0;
        int iskey = isupper(c);

        /* needed to delete semaphores */
        union semun arg;

        arg.val = 0;

        if ((c == '?') || (c == 'h')) {
            bb_show_usage();
        }

        /* we don't need case information any more */
        c = tolower(c);

        /* make sure the option is in range: allowed are q, m, s */
        if (c != 'q' && c != 'm' && c != 's') {
            bb_show_usage();
        }

        if (iskey) {
            /* keys are in hex or decimal */
            key_t key = xstrtoul(optarg, 0);

            if (key == IPC_PRIVATE) {
                error++;
                bb_error_msg("illegal key (%s)", optarg);
                continue;
            }

            /* convert key to id */
            id = ((c == 'q') ? msgget(key, 0) :
                (c == 'm') ? shmget(key, 0, 0) : semget(key, 0, 0));

            if (id < 0) {
                const char *errmsg;

                error++;
                switch (errno) {
                case EACCES:
                    errmsg = "permission denied for";
                    break;
                case EIDRM:
                    errmsg = "already removed";
                    break;
                case ENOENT:
                    errmsg = "invalid";
                    break;
                default:
                    errmsg = "unknown error in";
                    break;
                }
                bb_error_msg("%s %s (%s)", errmsg, "key", optarg);
                continue;
            }
        } else {
            /* ids are in decimal */
            id = xatoul(optarg);
        }

        result = ((c == 'q') ? msgctl(id, IPC_RMID, NULL) :
                (c == 'm') ? shmctl(id, IPC_RMID, NULL) :
                semctl(id, 0, IPC_RMID, arg));

        if (result) {
            const char *errmsg;
            const char *const what = iskey ? "key" : "id";

            error++;
            switch (errno) {
            case EACCES:
            case EPERM:
                errmsg = "permission denied for";
                break;
            case EINVAL:
                errmsg = "invalid";
                break;
            case EIDRM:
                errmsg = "already removed";
                break;
            default:
                errmsg = "unknown error in";
                break;
            }
            bb_error_msg("%s %s (%s)", errmsg, what, optarg);
            continue;
        }
    }

    /* print usage if we still have some arguments left over */
    if (optind != argc) {
        bb_show_usage();
    }

    /* exit value reflects the number of errors encountered */
    return error;
}