cmd/ctrun/ctrun.c

	ctrun.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/wait.h>
#include <sys/ctfs.h>
#include <sys/contract.h>
#include <sys/contract/process.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <limits.h>
#include <libuutil.h>
#include <libcontract.h>
#include <libcontract_priv.h>

#include <locale.h>
#include <langinfo.h>

static int opt_verbose;
static int opt_Verbose;

#define OPT_NORMAL  0x1
#define OPT_FATAL   0x2

typedef struct optvect {
    const char  *opt_name;
    uint_t      opt_value;
    uint_t      opt_flags;
} optvect_t;

static optvect_t option_params[] = {
    { "noorphan", CT_PR_NOORPHAN },
    { "pgrponly", CT_PR_PGRPONLY },
    { "regent", CT_PR_REGENT },
    { "inherit", CT_PR_INHERIT },
    { NULL }
};

static optvect_t option_events[] = {
    { "core", CT_PR_EV_CORE, OPT_NORMAL | OPT_FATAL },
    { "signal", CT_PR_EV_SIGNAL, OPT_NORMAL | OPT_FATAL },
    { "hwerr", CT_PR_EV_HWERR, OPT_NORMAL | OPT_FATAL },
    { "empty", CT_PR_EV_EMPTY, OPT_NORMAL },
    { "fork", CT_PR_EV_FORK, OPT_NORMAL },
    { "exit", CT_PR_EV_EXIT, OPT_NORMAL },
    { NULL }
};

typedef enum lifetime {
    LT_NONE,
    LT_CHILD,
    LT_CONTRACT
} lifetime_t;

/*
 * Exit code to use when the child exited abnormally (i.e. exited with
 * a status we are unable to emulate).
 */
#define EXIT_BADCHILD   123

#define USAGESTR    \
    "Usage: %s [-i eventlist] [-f eventlist] [-l lifetime] \n" \
    "\t[-o optionlist] [-r count [-t]] [-v] command\n"

/*
 * usage
 *
 * Educate the user.
 */
static void
usage(void)
{
    (void) fprintf(stderr, gettext(USAGESTR), uu_getpname());
    exit(UU_EXIT_USAGE);
}

/*
 * bit2str
 *
 * Convert a bit into its string representation.
 */
static const char *
bit2str(optvect_t *options, uint_t bit)
{
    for (; options->opt_name; options++)
        if (options->opt_value == bit)
            return (options->opt_name);
    return (NULL);
}

/*
 * str2bit
 *
 * Convert a string into its bit representation.  If match is set, only
 * look at those options with the match bit set in its opt_flags
 * field.
 */
static uint_t
str2bit(optvect_t *options, int match, const char *str, int len)
{
    for (; options->opt_name; options++) {
        if (match && (options->opt_flags & match) == 0)
            continue;
        if (strncmp(str, options->opt_name, len) == 0)
            return (options->opt_value);
    }
    return (0);
}

/*
 * opt2bits
 *
 * Given a set of textual options separated by commas or spaces,
 * convert them to a set of bits.  Errors are fatal, except for empty
 * options (which are ignored) and duplicate options (which are
 * idempotent).
 */
static void
opt2bits(optvect_t *options, int match, const char *str, uint_t *bits, char c)
{
    const char *ptr, *next = str;
    uint_t result = 0;
    uint_t bit;
    int none = 0;

    while (*str) {
        int len;

        ptr = strpbrk(str, ", ");
        if (ptr != NULL) {
            len = ptr - str;
            next = ptr + 1;
        } else {
            len = strlen(str);
            next = str + len;
        }
        if (len == 0) {
            uu_warn(gettext("empty option\n"));
            bit = 0;
        } else {
            bit = str2bit(options, match, str, len);
            if (bit == 0 && strncmp(str, "none", len) == 0) {
                none = 1;
                if (result)
                    goto noneerr;
            } else if (bit == 0) {
                uu_warn(gettext("unrecognized option '%.*s'\n"),
                    len, str);
                uu_warn(gettext("error parsing '-%c' option\n"),
                    c);
                usage();
            } else if (none) {
                goto noneerr;
            }
            if (result & bit)
                uu_warn(gettext("option '%.*s' "
                    "specified twice\n"), len, str);
        }
        result |= bit;
        str = next;
    }

    *bits = result;
    return;

noneerr:
    uu_warn(gettext("option is incompatible with others: '%s'\n"), "none");
    usage();
}

/*
 * close_on_exec
 *
 * Given a fd, marks it close-on-exec.
 */
static int
close_on_exec(int fd)
{
    int flags = fcntl(fd, F_GETFD, 0);
    if ((flags != -1) && (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) != -1))
        return (0);
    return (-1);
}

/*
 * v_printf
 *
 * Output routine for messages printed only when -v is specified.
 */
/* PRINTFLIKE1 */
static void
v_printf(const char *format, ...)
{
    va_list va;

    if (opt_verbose) {
        (void) printf("%s(%ld): ", uu_getpname(), getpid());
        va_start(va, format);
        (void) vprintf(format, va);
        va_end(va);
    }
}

/*
 * get_event
 *
 * Reads and acknowledges an event.  Returns the event type.
 */
static uint_t
get_event(int fd, int ctfd, ctid_t ctid)
{
    ct_evthdl_t ev;
    uint_t result;
    ctevid_t evid;

    for (;;) {
        int efd;

        /*
         * Normally we only need to look at critical messages.
         * If we are displaying contract events, however, we
         * have to read them all.
         */
        errno = opt_verbose ? ct_event_read(fd, &ev) :
            ct_event_read_critical(fd, &ev);
        if (errno != 0)
            uu_die(gettext("failed to listen to contract events"));

        /*
         * If requested, display the event.
         */
        if (opt_verbose) {
            v_printf(gettext("event from contract %ld: "),
                ct_event_get_ctid(ev));
            contract_event_dump(stdout, ev, opt_Verbose);
            if ((ct_event_get_flags(ev) & CTE_INFO) != 0) {
                ct_event_free(ev);
                continue;
            }
        }

        /*
         * We're done if this event is one of ours.
         */
        evid = ct_event_get_evid(ev);
        if (ct_event_get_ctid(ev) == ctid)
            break;

        /*
         * ACK events from other contracts.
         * This shouldn't happen, but it could.
         */
        efd = contract_open(ct_event_get_ctid(ev), "process", "ctl",
            O_WRONLY);
        if (efd != -1) {
            (void) ct_ctl_ack(efd, evid);
            (void) close(efd);
        }
        ct_event_free(ev);
    }

    /*
     * Note that if we want to use ctrun as a simple restarter, we
     * need persistently keep track of fatal events so we can
     * properly handle the death of the contract.  Rather than keep
     * a file or somesuch lying around, it might make more sense to
     * leave the significant fatal event sitting in the queue so
     * that a restarted instance of ctrun can pick it up.  For now
     * we'll just ACK all events.
     */
    (void) ct_ctl_ack(ctfd, evid);

    result = ct_event_get_type(ev);
    ct_event_free(ev);

    return (result);
}

/*
 * abandon
 *
 * Given an fd for a contract's ctl file, abandon the contract and
 * close the file.
 */
static void
abandon(int ctfd)
{
    if (ct_ctl_abandon(ctfd) == -1)
        uu_die(gettext("failed to abandon contract %d"), ctfd);

    (void) close(ctfd);
}

static int chldstat;
static int chldexited;

/*
 * sigchld
 *
 * Our SIGCHLD handler.  Sets chldstat and chldexited so the
 * interrupted code knows what happened.
 */
/*ARGSUSED*/
static void
sigchld(int sig, struct siginfo *si, void *ucp)
{
    int err = errno;

    if (si->si_code == CLD_EXITED)
        chldstat = si->si_status;
    else
        chldstat = EXIT_BADCHILD;
    chldexited = 1;
    while (waitpid(si->si_pid, NULL, 0) == -1 && errno == EINTR)
        ;
    errno = err;
}

/*
 * dowait
 *
 * Waits for the specified child to exit.  Returns the exit code ctrun
 * should return.
 */
static int
dowait(int pid)
{
    pid_t wpid;
    int wstatus;

    do
        wpid = waitpid(pid, &wstatus, 0);
    while (wpid == -1 && errno == EINTR);

    if (wpid == -1)
        uu_die(gettext("wait failed"));

    if (WIFEXITED(wstatus))
        return (WEXITSTATUS(wstatus));
    else
        return (EXIT_BADCHILD);
}

int
main(int argc, char **argv)
{
    int fd, efd;
    pid_t   pid;
    ctid_t  ctid = 0;
    int ctfd;
    int pipefds[2];
    struct sigaction osact;

    int s;
    ctid_t  opt_adopt = 0;
    int opt_transfer = 0;
    int opt_count = -1;
    uint_t  opt_info = CT_PR_EV_CORE;
    uint_t  opt_crit = 0;
    uint_t  eff_fatal, opt_fatal = CT_PR_EV_HWERR;
    uint_t  eff_param, opt_param = 0;
    lifetime_t opt_life = LT_CONTRACT;

    (void) setlocale(LC_ALL, "");
    (void) textdomain(TEXT_DOMAIN);
    uu_alt_exit(UU_PROFILE_LAUNCHER);

    (void) uu_setpname(argv[0]);

    while ((s = getopt(argc, argv, "a:l:o:i:c:f:r:tvV")) != EOF) {
        switch (s) {
        case 'a':
            if (uu_strtoint(optarg, &opt_adopt, sizeof (opt_adopt),
                0, 0, INT32_MAX) == -1) {
                uu_warn(gettext("invalid contract ID '%s'\n"),
                    optarg);
                usage();
            }
            break;
        case 'v':
            opt_verbose = 1;
            break;
        case 'V':
            opt_Verbose = 1;
            opt_verbose = 1;
            break;
        case 't':
            opt_transfer = 1;
            break;
        case 'r':
            if (uu_strtoint(optarg, &opt_count, sizeof (opt_adopt),
                0, 0, INT32_MAX) == -1) {
                uu_warn(gettext("invalid count '%s'\n"),
                    optarg);
                usage();
            }
            break;
        case 'l':
            if (strcmp(optarg, "none") == 0) {
                opt_life = LT_NONE;
            } else if (strcmp(optarg, "child") == 0) {
                opt_life = LT_CHILD;
            } else if (strcmp(optarg, "contract") == 0) {
                opt_life = LT_CONTRACT;
            } else {
                uu_warn(gettext("invalid lifetime '%s'\n"),
                    optarg);
                usage();
            }

            break;
        case 'o':
            opt2bits(option_params, 0, optarg, &opt_param,
                optopt);
            break;
        case 'i':
            opt2bits(option_events, OPT_NORMAL, optarg, &opt_info,
                optopt);
            break;
        case 'c':
            opt2bits(option_events, OPT_NORMAL, optarg, &opt_crit,
                optopt);
            break;
        case 'f':
            opt2bits(option_events, OPT_FATAL, optarg, &opt_fatal,
                optopt);
            break;
        default:
            usage();
        }
    }
    argc -= optind;
    argv += optind;

    /*
     * Basic argument sanity checks.
     */
    if ((opt_life == LT_NONE) && (opt_param & CT_PR_NOORPHAN)) {
        uu_warn(gettext("cannot use option '%s' with lifetime '%s'\n"),
            bit2str(option_params, CT_PR_NOORPHAN), "none");
        usage();
    }

    if ((opt_life != LT_CONTRACT) && (opt_count >= 0)) {
        uu_warn(gettext("cannot restart with lifetime '%s'\n"),
            opt_life == LT_NONE ? "none" : "child");
        usage();
    }

    if ((opt_param & CT_PR_PGRPONLY) && (opt_count >= 0)) {
        uu_warn(gettext("cannot restart with option '%s'\n"),
            bit2str(option_params, CT_PR_PGRPONLY));
        usage();
    }

    if (opt_transfer && (opt_count == -1)) {
        uu_warn(gettext("cannot transfer when not restarting\n"));
        usage();
    }

    if (argc <= 0)
        usage();

    /*
     * Create a process contract template and our process's process
     * contract bundle endpoint.  Mark them close-on-exec so we
     * don't have to worry about closing them in our child.
     */
    fd = open64(CTFS_ROOT "/process/template", O_RDWR);
    if (fd == -1)
        uu_die(gettext("template open failed"));

    efd = open64(CTFS_ROOT "/process/pbundle", O_RDONLY);
    if (efd == -1)
        uu_die(gettext("process bundle open failed"));

    if (close_on_exec(fd) || close_on_exec(efd))
        uu_die(gettext("could not set FD_CLOEXEC"));

    /*
     * Set the process contract's terms based on our arguments.
     */
    if (errno = ct_pr_tmpl_set_param(fd, opt_param))
        uu_die(gettext("set param failed"));

    if (errno = ct_tmpl_set_informative(fd, opt_info))
        uu_die(gettext("set notify failed"));

    if (errno = ct_pr_tmpl_set_fatal(fd, opt_fatal))
        uu_die(gettext("set fatal failed"));

    if (opt_param & CT_PR_PGRPONLY)
        opt_crit = CT_PR_EV_EMPTY;
    else
        opt_crit |= opt_fatal | CT_PR_EV_EMPTY;
    if (errno = ct_tmpl_set_critical(fd, opt_crit))
        uu_die(gettext("set critical failed"));

    /*
     * Activate the template.
     */
    if (errno = ct_tmpl_activate(fd))
        uu_die(gettext("template activate failed"));

restart:
    if (opt_adopt) {
        /*
         * Adopt a specific contract.
         */
        ct_stathdl_t st;
        int stfd;

        if ((ctfd = contract_open(opt_adopt, "process", "ctl",
            O_WRONLY)) == -1)
            uu_die(gettext("could not open contract %ld"),
                opt_adopt);

        /*
         * Read the contract's terms so that we interpret its
         * events properly.
         */
        if (((stfd = contract_open(opt_adopt, "process", "status",
            O_RDONLY)) == -1) ||
            (errno = ct_status_read(stfd, CTD_FIXED, &st)) ||
            (errno = ct_pr_status_get_fatal(st, &eff_fatal)) ||
            (errno = ct_pr_status_get_param(st, &eff_param)))
            uu_die(gettext("could not stat contract %ld"),
                opt_adopt);
        ct_status_free(st);
        (void) close(stfd);

        if (errno = ct_ctl_adopt(ctfd))
            uu_die(gettext("could not adopt contract %ld"),
                opt_adopt);

        ctid = opt_adopt;
        opt_adopt = 0;
        v_printf(gettext("adopted contract id %ld\n"), ctid);
    } else {
        /*
         * Create a new process.
         */
        if (opt_life == LT_CONTRACT) {
            struct sigaction sact;

            /*
             * Since we are going to be waiting for and
             * reacting to contract events, install a
             * signal handler so we capture the exit status
             * of our child.
             */
            chldstat = UU_EXIT_OK;
            chldexited = 0;
            sact.sa_sigaction = sigchld;
            sact.sa_flags = SA_SIGINFO | SA_RESTART |
                SA_NOCLDSTOP;
            (void) sigemptyset(&sact.sa_mask);
            if (sigaction(SIGCHLD, &sact, &osact) == -1)
                uu_die(gettext("failed to install "
                    "sigchld handler"));
        } else if (opt_life == LT_NONE) {
            /*
             * Though we aren't waiting for our child to
             * exit, as a well-behaved command launcher we
             * must wait for it to exec.  On success the
             * pipe will simply close, and on failure the
             * proper exit status will be sent.
             */
            if (pipe(pipefds) == -1 ||
                close_on_exec(pipefds[0]) == -1 ||
                close_on_exec(pipefds[1]) == -1)
                uu_die(gettext("failed to create pipe"));
        }

        if ((pid = fork()) == -1) {
            uu_die(gettext("fork failed"));
        } else if (pid == 0) {
            int result = execvp(argv[0], argv);
            if (opt_life == LT_NONE) {
                char a = 1;
                int err = errno;

                (void) write(pipefds[1], &a, sizeof (a));
                errno = err;
            }
            if (result == -1)
                uu_xdie(errno == ENOENT ? 127 : 126,
                    gettext("exec failed"));
            uu_die(gettext("exec returned!\n"));
        }

        /*
         * Get the newly-created contract's id and ctl fd.
         */
        if (errno = contract_latest(&ctid))
            uu_die(gettext("could not get new contract's id"));
        if ((ctfd = contract_open(ctid, "process", "ctl",
            O_WRONLY)) == -1)
            uu_die(gettext("could not open contract"));

        /*
         * Clear the transfer parameter so that the contract
         * will be freed sooner and admins won't get nervous.
         */
        if (opt_transfer) {
            (void) ct_pr_tmpl_set_transfer(fd, 0);
            (void) ct_tmpl_activate(fd);
        }

        v_printf(gettext("created contract id %ld\n"), ctid);
        eff_param = opt_param;
        eff_fatal = opt_fatal;
    }

    if (opt_life == LT_CONTRACT) {
        uint_t event, errevent = 0;

        /*
         * Wait until the contract empties out.
         */
        do {
            event = get_event(efd, ctfd, ctid);
            if (event & eff_fatal) {
                if ((eff_param & CT_PR_PGRPONLY) == 0)
                    errevent = event;
                v_printf(gettext(
                    "fatal \"%s\" event from contract %ld\n"),
                    bit2str(option_events, event), ctid);
            }
        } while ((event & CT_PR_EV_EMPTY) == 0);

        /*
         * If we encountered a fatal error event, and we
         * haven't expended our maximum loop count, restart.
         */
        if ((errevent != 0) &&
            ((opt_count == 0) || (opt_count-- > 1))) {
            v_printf(gettext("failure in contract %ld, "
                "restarting command\n"), ctid);
            if (opt_transfer) {
                /*
                 * Add the failed contract to the new
                 * contract's terms so that its
                 * inherited subcontracts can be
                 * adopted by the new process.
                 */
                if (errno = ct_pr_tmpl_set_transfer(fd, ctid))
                    uu_die(gettext("set transfer failed"));
                if (errno = ct_tmpl_activate(fd))
                    uu_die(gettext(
                        "template activate failed"));
                (void) close(ctfd);
            } else {
                abandon(ctfd);
            }
            goto restart;
        }

        /*
         * At this point we are done with the contract; we
         * don't want it to be inherited when we exit.
         */
        abandon(ctfd);

        /*
         * In case there was a race between SIGCHLD delivery
         * and contract event delivery, disable the signal
         * handler and look for the child.
         */
        (void) sigaction(SIGCHLD, &osact, NULL);
        if (chldexited == 0)
            chldstat = dowait(pid);
    } else if (opt_life == LT_NONE) {
        char a;
        int result;

        chldstat = UU_EXIT_OK;
        (void) close(pipefds[1]);
        do {
            result = read(pipefds[0], &a, sizeof (a));
            if (result == -1 && errno != EINTR)
                uu_die(gettext("read failed"));
            if (result == 1)
                chldstat = dowait(pid);
        } while (result == -1);
    } else {
        chldstat = dowait(pid);
    }

    return (chldstat);
}