Colony » Colony Scout

/*

 * Copyright (c) 2005-2007, Kohsuke Ohtani

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the author nor the names of any co-contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

/*

 * pid.c - service for process id.

 */

#include <sys/prex.h>

#include <ipc/proc.h>

#include <ipc/ipc.h>

#include <sys/list.h>

#include <unistd.h>

#include <errno.h>

#include <stdlib.h>

#include <string.h>

#include "proc.h"

/*

 * getpid - get the process ID.

 */

pid_t

sys_getpid(void)

{

        ASSERT(curproc);

        return curproc->p_pid;

}

/*

 * getppid - get the parent process ID.

 */

pid_t

sys_getppid(void)

{

        ASSERT(curproc);

        return curproc->p_parent->p_pid;

}

/*

 * getpgid - get the process group ID for a process.

 *

 * If the specified pid is equal to 0, it returns the process

 * group ID of the calling process.

 */

int

sys_getpgid(pid_t pid, pid_t *retval)

{

        struct proc *p;

        ASSERT(curproc);

        if (pid == 0)

                p = curproc;

        else {

                if ((p = p_find(pid)) == NULL)

                        return ESRCH;

        }

        *retval = p->p_pgrp->pg_pgid;

        return 0;

}

/*

 * getsid - get the process group ID of a session leader.

 */

int

sys_getsid(pid_t pid, pid_t *retval)

{

        pid_t sid;

        struct proc *p, *leader;

        ASSERT(curproc);

        if (pid == 0)

                p = curproc;

        else {

                if ((p = p_find(pid)) == NULL)

                        return ESRCH;

        }

        leader = p->p_pgrp->pg_session->s_leader;

        sid = leader->p_pid;

        DPRINTF(("proc: getsid sid=%d\n", sid));

        *retval = sid;

        return 0;

}

/*

 * Move process to a new or existing process group.

 */

int

enterpgrp(struct proc *p, pid_t pgid)

{

        struct pgrp *pgrp;

        DPRINTF(("proc: enter pgrp pid=%d pgid=%d\n", p->p_pid, pgid));

        if ((pgrp = pg_find(pgid)) == NULL) {

                /*

                 * Create a new process group.

                 */

                DPRINTF(("proc: create new pgrp\n"));

                if ((pgrp = malloc(sizeof(struct pgrp))) == NULL)

                        return ENOMEM;

                memset(pgrp, 0, sizeof(*pgrp));

                list_init(&pgrp->pg_members);

                pgrp->pg_pgid = pgid;

                pg_add(pgrp);

        }

        /*

         * Remove from the old process group.

         * And, join an existing process group.

         */

        list_remove(&p->p_pgrp_link);

        list_insert(&pgrp->pg_members, &p->p_pgrp_link);

        pgrp->pg_session = curproc->p_pgrp->pg_session;

        p->p_pgrp = pgrp;

        return 0;

}

/*

 * Remove process from process group.

 */

int

leavepgrp(struct proc *p)

{

        struct pgrp *pgrp = p->p_pgrp;

        list_remove(&p->p_pgrp_link);

        if (list_empty(&pgrp->pg_members)) {

                /* XXX: do some work for session */

                pg_remove(pgrp);

                free(pgrp);

        }

        p->p_pgrp = 0;

        return (0);

}

/*

 * setpgid - set process group ID for job control.

 *

 * If the specified pid is equal to 0, the process ID of

 * the calling process is used. Also, if pgid is 0, the process

 * ID of the indicated process is used.

 */

int

sys_setpgid(pid_t pid, pid_t pgid)

{

        struct proc *p;

        DPRINTF(("proc: setpgid pid=%d pgid=%d\n", pid, pgid));

        if (pid == 0)

                p = curproc;

        else {

                if ((p = p_find(pid)) == NULL)

                        return ESRCH;

        }

        if (pgid < 0)

                return EINVAL;

        if (pgid == 0)

                pgid = p->p_pid;

        if (p->p_pgrp->pg_pgid == pgid)        /* already leader */

                return 0;

        return (enterpgrp(p, pgid));

}

/*

 * setsid - create session and set process group ID.

 */

int

sys_setsid(pid_t *retval)

{

        struct proc *p;

        struct pgrp *pgrp;

        struct session *sess;

        int error;

        DPRINTF(("proc: setsid sid=%d\n", curproc->p_pid));

        p = curproc;

        if (p->p_pid == p->p_pgrp->pg_pgid)        /* already leader */

                return EPERM;

        if ((sess = malloc(sizeof(struct session))) == NULL)

                return ENOMEM;

        memset(sess, 0, sizeof(*sess));

        /*

         * Create a new process group.

         */

        if ((error = enterpgrp(p, p->p_pid)) != 0) {

                free(sess);

                return error;

        }

        pgrp = p->p_pgrp;

        /*

         * Create a new session.

         */

        sess->s_refcnt = 1;

        sess->s_leader = p;

        sess->s_ttyhold = 0;

        pgrp->pg_session = sess;

        *retval = p->p_pid;

        return 0;

}