/*
* 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.
*/
/*
* Process server:
*
* A process server is responsible to handle process ID, group ID,
* signal and fork()/exec() state. Since Prex microkernel does not
* have the concept about process or process group, the process
* server will map each Prex task to POSIX process.
*
* Prex does not support uid (user ID) and gid (group ID) because
* it runs only in a single user mode. The value of uid and gid is
* always returned as 1 for all process. These are handled by the
* library stubs, and it is out of scope in this server.
*
* Important Notice:
* This server is made as a single thread program to reduce many locks
* and to keep the code clean. So, we should not block in the kernel
* for any service. If some service must wait an event, it should wait
* within the library stub in the client application.
*/
#include <prex/prex.h>
#include <server/proc.h>
#include <server/stdmsg.h>
#include <server/object.h>
#include <sys/list.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include "proc.h"
/* forward declarations */
static int proc_version(struct msg *msg);
static int proc_debug(struct msg *msg);
static int proc_shutdown(struct msg *msg);
static int proc_exec(struct msg *msg);
static int proc_pstat(struct msg *msg);
static int proc_register(struct msg *msg);
static int proc_setinit(struct msg *msg);
/*
* Message mapping
*/
struct msg_map {
int code;
int (*func)(struct msg *);
};
static const struct msg_map procmsg_map[] = {
{STD_VERSION, proc_version},
{STD_DEBUG, proc_debug},
{STD_SHUTDOWN, proc_shutdown},
{PS_GETPID, proc_getpid},
{PS_GETPPID, proc_getppid},
{PS_GETPGID, proc_getpgid},
{PS_SETPGID, proc_setpgid},
{PS_FORK, proc_fork},
{PS_EXIT, proc_exit},
{PS_STOP, proc_stop},
{PS_WAITPID, proc_waitpid},
{PS_KILL, proc_kill},
{PS_EXEC, proc_exec},
{PS_PSTAT, proc_pstat},
{PS_REGISTER, proc_register},
{PS_SETINIT, proc_setinit},
{0, 0},
};
static struct proc proc0; /* process data of this server (pid=0) */
static struct pgrp pgrp0; /* process group for process server */
struct proc initproc; /* process slot for init process (pid=1) */
struct proc *curproc; /* current (caller) process */
struct list allproc; /* list of all processes */
static void
newproc(struct proc *p, pid_t pid, task_t task)
{
p->parent = &proc0;
p->pgrp = &pgrp0;
p->stat = SRUN;
p->exit_code = 0;
p->wait_vfork = 0;
p->pid = pid;
p->task = task;
list_init(&p->children);
list_insert(&allproc, &p->link);
proc_add(p);
list_insert(&proc0.children, &p->sibling);
list_insert(&pgrp0.members, &p->pgrp_link);
}
/*
* exec() - Update pid to track the mapping with task id.
*
* The almost all work is done by a exec server for exec() emulation.
* So, there is not so many jobs here...
*/
static int
proc_exec(struct msg *msg)
{
task_t org_task, new_task;
struct proc *p, *parent;
dprintf("proc_exec: proc=%x\n", curproc);
org_task = msg->data[0];
new_task = msg->data[1];
if ((p = task_to_proc(org_task)) == NULL)
return EINVAL;
proc_remove(p);
p->task = new_task;
proc_add(p);
p->stack_base = (void *)msg->data[2];
parent = p->parent;
if (parent != NULL && parent->wait_vfork)
vfork_end(parent);
return 0;
}
/*
* Get process status.
*/
static int
proc_pstat(struct msg *msg)
{
task_t task;
struct proc *p;
dprintf("proc_pstat: task=%x\n", msg->data[0]);
task = msg->data[0];
if ((p = task_to_proc(task)) == NULL)
return EINVAL;
msg->data[0] = (int)p->pid;
msg->data[2] = (int)p->stat;
if (p->parent == NULL)
msg->data[1] = (int)0;
else
msg->data[1] = (int)p->parent->pid;
return 0;
}
/*
* Set init process (pid=1).
*/
static int
proc_setinit(struct msg *msg)
{
struct proc *p;
p = &initproc;
if (p->stat == SRUN)
return EPERM;
newproc(p, 1, msg->hdr.task);
return 0;
}
/*
* Register boot task.
*/
static int
proc_register(struct msg *msg)
{
struct proc *p;
pid_t pid;
if ((p = malloc(sizeof(struct proc))) == NULL)
return ENOMEM;
if ((pid = pid_assign()) == 0)
return EAGAIN; /* Too many processes */
newproc(p, pid, msg->hdr.task);
return 0;
}
static int
proc_version(struct msg *msg)
{
return 0;
}
static int
proc_shutdown(struct msg *msg)
{
return 0;
}
static int
proc_debug(struct msg *msg)
{
#ifdef DEBUG_PROC
struct proc *p;
list_t n;
char stat[][5] = { "RUN ", "ZOMB", "STOP" };
printf("<Process Server>\n");
printf("Dump process\n");
printf(" pid ppid stat task\n");
printf(" ------ ------ ---- --------\n");
for (n = list_first(&allproc); n != &allproc;
n = list_next(n)) {
p = list_entry(n, struct proc, link);
printf(" %6d %6d %s %08x\n",
p->pid, p->parent->pid, stat[p->stat], p->task);
}
printf("\n");
#endif
return 0;
}
static void
init(void)
{
struct proc *p;
tty_init();
table_init();
/*
* Setup a process for ourselves.
* pid=0 is always reserved by process server.
*/
p = &proc0;
p->parent = 0;
p->pgrp = &pgrp0;
p->stat = SRUN;
p->exit_code = 0;
p->wait_vfork = 0;
p->pid = 0;
p->task = task_self();
list_init(&p->children);
list_init(&allproc);
list_init(&pgrp0.members);
proc_add(p);
pgrp_add(&pgrp0);
list_insert(&pgrp0.members, &p->pgrp_link);
}
/*
* Main routine for process service.
*/
int
main(int argc, char *argv[])
{
static struct msg msg;
const struct msg_map *map;
object_t obj;
int err;
sys_log("Starting Process Server\n");
/*
* Boost current priority.
*/
thread_setprio(thread_self(), PRIO_PROC);
/*
* Initialize everything.
*/
init();
/*
* Create an object to expose our service.
*/
if ((err = object_create(OBJNAME_PROC, &obj)) != 0)
sys_panic("proc: fail to create object");
/*
* Message loop
*/
for (;;) {
/*
* Wait for an incoming request.
*/
err = msg_receive(obj, &msg, sizeof(msg));
if (err)
continue;
err = EINVAL;
map = &procmsg_map[0];
while (map->code != 0) {
if (map->code == msg.hdr.code) {
/* Get current process */
curproc = task_to_proc(msg.hdr.task);
/* Update the capability of caller task. */
if (curproc && task_getcap(msg.hdr.task,
&curproc->cap))
break;
err = map->func(&msg);
break;
}
map++;
}
/*
* Reply to the client.
*/
msg.hdr.status = err;
msg_reply(obj, &msg, sizeof(msg));
#ifdef DEBUG_PROC
if (err)
dprintf("msg code=%x error=%d\n", map->code, err);
#endif
}
return 0;
}