source: mainline/uspace/srv/loader/main.c@ 3abfe9a8

/*
 * 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 loader
 * @brief Loads and runs programs from VFS.
 * @{
 */
/**
 * @file
 * @brief Loads and runs programs from VFS.
 *
 * The program loader is a special init binary. Its image is used
 * to create a new task upon a @c task_spawn syscall. The syscall
 * returns the id of a phone connected to the newly created task.
 *
 * The caller uses this phone to send the pathname and various other
 * information to the loader. This is normally done by the C library
 * and completely hidden from applications.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <bool.h>
#include <fcntl.h>
#include <sys/types.h>
#include <ipc/services.h>
#include <ipc/loader.h>
#include <ipc/ns.h>
#include <macros.h>
#include <loader/pcb.h>
#include <errno.h>
#include <async.h>
#include <str.h>
#include <as.h>

#include <elf.h>
#include <elf_load.h>

#define DPRINTF(...)

/** Pathname of the file that will be loaded */
static char *pathname = NULL;

/** The Program control block */
static pcb_t pcb;

/** Current working directory */
static char *cwd = NULL;

/** Number of arguments */
static int argc = 0;
/** Argument vector */
static char **argv = NULL;
/** Buffer holding all arguments */
static char *arg_buf = NULL;

/** Number of preset files */
static int filc = 0;
/** Preset files vector */
static fdi_node_t **filv = NULL;
/** Buffer holding all preset files */
static fdi_node_t *fil_buf = NULL;

static elf_info_t prog_info;
static elf_info_t interp_info;

static bool is_dyn_linked;

/** Used to limit number of connections to one. */
static bool connected = false;

static void ldr_get_taskid(ipc_callid_t rid, ipc_call_t *request)
{
        ipc_callid_t callid;
        task_id_t task_id;
        size_t len;
        
        task_id = task_get_id();
        
        if (!async_data_read_receive(&callid, &len)) {
                async_answer_0(callid, EINVAL);
                async_answer_0(rid, EINVAL);
                return;
        }
        
        if (len > sizeof(task_id))
                len = sizeof(task_id);
        
        async_data_read_finalize(callid, &task_id, len);
        async_answer_0(rid, EOK);
}

/** Receive a call setting the current working directory.
 *
 * @param rid
 * @param request
 */
static void ldr_set_cwd(ipc_callid_t rid, ipc_call_t *request)
{
        char *buf;
        int rc = async_data_write_accept((void **) &buf, true, 0, 0, 0, NULL);
        
        if (rc == EOK) {
                if (cwd != NULL)
                        free(cwd);
                
                cwd = buf;
        }
        
        async_answer_0(rid, rc);
}

/** Receive a call setting pathname of the program to execute.
 *
 * @param rid
 * @param request
 */
static void ldr_set_pathname(ipc_callid_t rid, ipc_call_t *request)
{
        char *buf;
        int rc = async_data_write_accept((void **) &buf, true, 0, 0, 0, NULL);
        
        if (rc == EOK) {
                if (pathname != NULL)
                        free(pathname);
                
                pathname = buf;
        }
        
        async_answer_0(rid, rc);
}

/** Receive a call setting arguments of the program to execute.
 *
 * @param rid
 * @param request
 */
static void ldr_set_args(ipc_callid_t rid, ipc_call_t *request)
{
        char *buf;
        size_t buf_size;
        int rc = async_data_write_accept((void **) &buf, true, 0, 0, 0, &buf_size);
        
        if (rc == EOK) {
                /*
                 * Count number of arguments
                 */
                char *cur = buf;
                int count = 0;
                
                while (cur < buf + buf_size) {
                        size_t arg_size = str_size(cur);
                        cur += arg_size + 1;
                        count++;
                }
                
                /*
                 * Allocate new argv
                 */
                char **_argv = (char **) malloc((count + 1) * sizeof(char *));
                if (_argv == NULL) {
                        free(buf);
                        async_answer_0(rid, ENOMEM);
                        return;
                }
                
                /*
                 * Fill the new argv with argument pointers
                 */
                cur = buf;
                count = 0;
                while (cur < buf + buf_size) {
                        _argv[count] = cur;
                        
                        size_t arg_size = str_size(cur);
                        cur += arg_size + 1;
                        count++;
                }
                _argv[count] = NULL;
                
                /*
                 * Copy temporary data to global variables
                 */
                if (arg_buf != NULL)
                        free(arg_buf);
                
                if (argv != NULL)
                        free(argv);
                
                argc = count;
                arg_buf = buf;
                argv = _argv;
        }
        
        async_answer_0(rid, rc);
}

/** Receive a call setting preset files of the program to execute.
 *
 * @param rid
 * @param request
 */
static void ldr_set_files(ipc_callid_t rid, ipc_call_t *request)
{
        fdi_node_t *buf;
        size_t buf_size;
        int rc = async_data_write_accept((void **) &buf, false, 0, 0,
            sizeof(fdi_node_t), &buf_size);
        
        if (rc == EOK) {
                int count = buf_size / sizeof(fdi_node_t);
                
                /*
                 * Allocate new filv
                 */
                fdi_node_t **_filv = (fdi_node_t **) calloc(count + 1, sizeof(fdi_node_t *));
                if (_filv == NULL) {
                        free(buf);
                        async_answer_0(rid, ENOMEM);
                        return;
                }
                
                /*
                 * Fill the new filv with argument pointers
                 */
                int i;
                for (i = 0; i < count; i++)
                        _filv[i] = &buf[i];
                
                _filv[count] = NULL;
                
                /*
                 * Copy temporary data to global variables
                 */
                if (fil_buf != NULL)
                        free(fil_buf);
                
                if (filv != NULL)
                        free(filv);
                
                filc = count;
                fil_buf = buf;
                filv = _filv;
        }
        
        async_answer_0(rid, EOK);
}

/** Load the previously selected program.
 *
 * @param rid
 * @param request
 * @return 0 on success, !0 on error.
 */
static int ldr_load(ipc_callid_t rid, ipc_call_t *request)
{
        int rc;
        
        rc = elf_load_file(pathname, 0, &prog_info);
        if (rc != EE_OK) {
                DPRINTF("Failed to load executable '%s'.\n", pathname);
                async_answer_0(rid, EINVAL);
                return 1;
        }
        
        elf_create_pcb(&prog_info, &pcb);
        
        pcb.cwd = cwd;
        
        pcb.argc = argc;
        pcb.argv = argv;
        
        pcb.filc = filc;
        pcb.filv = filv;
        
        if (prog_info.interp == NULL) {
                /* Statically linked program */
                is_dyn_linked = false;
                async_answer_0(rid, EOK);
                return 0;
        }
        
        rc = elf_load_file(prog_info.interp, 0, &interp_info);
        if (rc != EE_OK) {
                DPRINTF("Failed to load interpreter '%s.'\n",
                    prog_info.interp);
                async_answer_0(rid, EINVAL);
                return 1;
        }
        
        is_dyn_linked = true;
        async_answer_0(rid, EOK);
        
        return 0;
}


/** Run the previously loaded program.
 *
 * @param rid
 * @param request
 * @return 0 on success, !0 on error.
 */
static void ldr_run(ipc_callid_t rid, ipc_call_t *request)
{
        const char *cp;
        
        /* Set the task name. */
        cp = str_rchr(pathname, '/');
        cp = (cp == NULL) ? pathname : (cp + 1);
        task_set_name(cp);
        
        if (is_dyn_linked == true) {
                /* Dynamically linked program */
                DPRINTF("Run ELF interpreter.\n");
                DPRINTF("Entry point: %p\n", interp_info.entry);
                
                async_answer_0(rid, EOK);
                elf_run(&interp_info, &pcb);
        } else {
                /* Statically linked program */
                async_answer_0(rid, EOK);
                elf_run(&prog_info, &pcb);
        }
        
        /* Not reached */
}

/** Handle loader connection.
 *
 * Receive and carry out commands (of which the last one should be
 * to execute the loaded program).
 */
static void ldr_connection(ipc_callid_t iid, ipc_call_t *icall)
{
        ipc_callid_t callid;
        ipc_call_t call;
        int retval;
        
        /* Already have a connection? */
        if (connected) {
                async_answer_0(iid, ELIMIT);
                return;
        }
        
        connected = true;
        
        /* Accept the connection */
        async_answer_0(iid, EOK);
        
        /* Ignore parameters, the connection is already open */
        (void) iid;
        (void) icall;
        
        while (1) {
                callid = async_get_call(&call);
                
                switch (IPC_GET_IMETHOD(call)) {
                case IPC_M_PHONE_HUNGUP:
                        exit(0);
                case LOADER_GET_TASKID:
                        ldr_get_taskid(callid, &call);
                        continue;
                case LOADER_SET_CWD:
                        ldr_set_cwd(callid, &call);
                        continue;
                case LOADER_SET_PATHNAME:
                        ldr_set_pathname(callid, &call);
                        continue;
                case LOADER_SET_ARGS:
                        ldr_set_args(callid, &call);
                        continue;
                case LOADER_SET_FILES:
                        ldr_set_files(callid, &call);
                        continue;
                case LOADER_LOAD:
                        ldr_load(callid, &call);
                        continue;
                case LOADER_RUN:
                        ldr_run(callid, &call);
                        /* Not reached */
                default:
                        retval = EINVAL;
                        break;
                }
                
                if (IPC_GET_IMETHOD(call) != IPC_M_PHONE_HUNGUP)
                        async_answer_0(callid, retval);
        }
}

/** Program loader main function.
 */
int main(int argc, char *argv[])
{
        /* Set a handler of incomming connections. */
        async_set_client_connection(ldr_connection);
        
        /* Introduce this task to the NS (give it our task ID). */
        task_id_t id = task_get_id();
        int rc = async_req_2_0(PHONE_NS, NS_ID_INTRO, LOWER32(id), UPPER32(id));
        if (rc != EOK)
                return -1;
        
        /* Register at naming service. */
        if (service_register(SERVICE_LOAD) != EOK)
                return -2;
        
        async_manager();
        
        /* Never reached */
        return 0;
}

/** @}
 */