source: mainline/uspace/lib/libc/generic/loader.c@ 24345a5

/*
 * Copyright (c) 2008 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */ 

#include <ipc/ipc.h>
#include <ipc/loader.h>
#include <libc.h>
#include <task.h>
#include <string.h>
#include <stdlib.h>
#include <async.h>
#include <errno.h>
#include <vfs/vfs.h>
#include <loader/loader.h>

/** Connect to a new program loader.
 *
 * Spawns a new program loader task and returns the connection structure.
 * @param name  Symbolic name to set on the newly created task.
 * @return      Pointer to the loader connection structure (should be
 *              de-allocated using free() after use).
 */
loader_t *loader_spawn(char *name)
{
        int phone_id, rc;
        loader_t *ldr;

        /*
         * Ask kernel to spawn a new loader task.
         */
        rc = __SYSCALL3(SYS_PROGRAM_SPAWN_LOADER, (sysarg_t) &phone_id,
                (sysarg_t) name, strlen(name));
        if (rc != 0)
                return NULL;

        /*
         * Say hello so that the loader knows the incoming connection's
         * phone hash.
         */
        rc = async_req_0_0(phone_id, LOADER_HELLO);
        if (rc != EOK)
                return NULL;

        ldr = malloc(sizeof(loader_t));
        if (ldr == NULL)
                return NULL;

        ldr->phone_id = phone_id;
        return ldr;
}

/** Get ID of the new task.
 *
 * Retrieves the ID of the new task from the loader.
 *
 * @param ldr           Loader connection structure.
 * @param task_id       Points to a variable where the ID should be stored.
 * @return              Zero on success or negative error code.
 */
int loader_get_task_id(loader_t *ldr, task_id_t *task_id)
{
        ipc_call_t answer;
        aid_t req;
        int rc;
        ipcarg_t retval;

        /* Get task ID. */
        req = async_send_0(ldr->phone_id, LOADER_GET_TASKID, &answer);
        rc = ipc_data_read_start(ldr->phone_id, task_id, sizeof(task_id_t));
        if (rc != EOK) {
                async_wait_for(req, NULL);
                return rc;
        }

        async_wait_for(req, &retval);
        return (int)retval;
}

/** Set pathname of the program to load.
 *
 * Sets the name of the program file to load. The name can be relative
 * to the current working directory (it will be absolutized before
 * sending to the loader).
 *
 * @param ldr           Loader connection structure.
 * @param path          Pathname of the program file.
 * @return              Zero on success or negative error code.
 */
int loader_set_pathname(loader_t *ldr, const char *path)
{
        ipc_call_t answer;
        aid_t req;
        int rc;
        ipcarg_t retval;

        char *pa;
        size_t pa_len;

        pa = absolutize(path, &pa_len);
        if (!pa)
                return 0;

        /* Send program pathname */
        req = async_send_0(ldr->phone_id, LOADER_SET_PATHNAME, &answer);
        rc = ipc_data_write_start(ldr->phone_id, (void *)pa, pa_len);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                return rc;
        }

        free(pa);

        async_wait_for(req, &retval);
        return (int)retval;
}


/** Set command-line arguments for the program.
 *
 * Sets the vector of command-line arguments to be passed to the loaded
 * program. By convention, the very first argument is typically the same as
 * the command used to execute the program.
 *
 * @param ldr           Loader connection structure.
 * @param argv          NULL-terminated array of pointers to arguments.
 * @return              Zero on success or negative error code.
 */
int loader_set_args(loader_t *ldr, char *const argv[])
{
        aid_t req;
        ipc_call_t answer;
        ipcarg_t rc;

        char *const *ap;
        char *dp;
        char *arg_buf;
        size_t buffer_size;

        /* 
         * Serialize the arguments into a single array. First
         * compute size of the buffer needed.
         */
        ap = argv;
        buffer_size = 0;
        while (*ap != NULL) {
                buffer_size += strlen(*ap) + 1;
                ++ap;
        }

        arg_buf = malloc(buffer_size);
        if (arg_buf == NULL) return ENOMEM;

        /* Now fill the buffer with null-terminated argument strings */
        ap = argv;
        dp = arg_buf;
        while (*ap != NULL) {
                strcpy(dp, *ap);
                dp += strlen(*ap) + 1;

                ++ap;
        }

        /* Send serialized arguments to the loader */

        req = async_send_0(ldr->phone_id, LOADER_SET_ARGS, &answer);
        rc = ipc_data_write_start(ldr->phone_id, (void *)arg_buf, buffer_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                return rc;
        }

        async_wait_for(req, &rc);
        if (rc != EOK) return rc;

        /* Free temporary buffer */
        free(arg_buf);

        return EOK;
}

/** Instruct loader to load the program.
 *
 * If this function succeeds, the program has been successfully loaded
 * and is ready to be executed.
 *
 * @param ldr           Loader connection structure.
 * @return              Zero on success or negative error code.
 */
int loader_load_program(loader_t *ldr)
{
        int rc;

        rc = async_req_0_0(ldr->phone_id, LOADER_LOAD);
        if (rc != EOK)
                return rc;

        return EOK;
}

/** Instruct loader to execute the program.
 *
 * Note that this function blocks until the loader actually replies
 * so you cannot expect this function to return if you are debugging
 * the task and its thread is stopped.
 *
 * After using this function, no further operations must be performed
 * on the loader structure. It should be de-allocated using free().
 *
 * @param ldr           Loader connection structure.
 * @return              Zero on success or negative error code.
 */
int loader_run(loader_t *ldr)
{
        int rc;

        rc = async_req_0_0(ldr->phone_id, LOADER_RUN);
        if (rc != EOK)
                return rc;

        return EOK;
}

/** Cancel the loader session.
 *
 * Tells the loader not to load any program and terminate.
 * After using this function, no further operations must be performed
 * on the loader structure. It should be de-allocated using free().
 *
 * @param ldr           Loader connection structure.
 * @return              Zero on success or negative error code.
 */
void loader_abort(loader_t *ldr)
{
        ipc_hangup(ldr->phone_id);
        ldr->phone_id = 0;
}

/** @}
 */