/* 
 * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM.
 */

#include <metalsvm/stdarg.h>
#include <metalsvm/stdio.h>
#include <metalsvm/syscall.h>
#include <metalsvm/tasks.h>
#include <metalsvm/errno.h>
#include <metalsvm/spinlock.h>
#include <metalsvm/time.h>

#include <lwip/sockets.h>

static int sys_write(int fildes, const char *buf, size_t len)
{
	int i;

	if (BUILTIN_EXPECT(!buf, 0))
		return -1;

	for (i = 0; i<len; i++, buf++) {
		kputchar(*buf);
	}
        
	return len;
}

static int sys_sbrk(int incr)
{
	task_t* task = per_core(current_task);
	vma_t* tmp = NULL;
	int ret;

	spinlock_lock(&task->vma_lock);

	tmp = task->vma_list;
        while(tmp && !((task->end_heap >= tmp->start) && (task->end_heap <= tmp->end)))
		tmp = tmp->next;

	ret = (int) task->end_heap;
	task->end_heap += incr;
	if (task->end_heap < task->start_heap)
		task->end_heap = task->start_heap;
	
	// resize virtual memory area
	if (tmp && (tmp->end <= task->end_heap))
		tmp->end = task->end_heap;

	spinlock_unlock(&task->vma_lock);

	return ret;
}

int syscall_handler(uint32_t sys_nr, ...)
{
	int ret = -EINVAL;
	va_list vl;

	check_workqueues();

	va_start(vl, sys_nr);

	switch(sys_nr) 
	{
	case __NR_exit:
		sys_exit(va_arg(vl, uint32_t));
		ret = 0;
		break;
	case __NR_write: {
			int fildes = va_arg(vl, int);
			const char* buf = va_arg(vl, const char*);
			size_t len = va_arg(vl, size_t);
		
			ret = sys_write(fildes, buf, len);
			break;
		}
	case __NR_open:
		ret = 1;
		break;
	case __NR_close:
		ret = 0;
		break;
	case __NR_sbrk: {
			int incr = va_arg(vl, int);

			ret = sys_sbrk(incr);
			break;
		}
	case __NR_getpid:
		ret = per_core(current_task)->id;
		break;
	case __NR_fork:
		ret = sys_fork();
		break;
	case __NR_wait: {
			int32_t* status = va_arg(vl, int32_t*);
	
			ret = wait(status);
			break;
		}
	case __NR_execve: {
			const char* name = va_arg(vl, const char*);
			char** argv = va_arg(vl, char**);
			char** env = va_arg(vl, char**);

			ret = sys_execve(name, argv, env);
			break;
		}
	case __NR_times: {
			struct tms* buffer = va_arg(vl, struct tms*);
			clock_t* clock = va_arg(vl, clock_t*);

			ret = sys_times(buffer, clock);
			break;
		}
	case __NR_socket: {
			int domain= va_arg(vl,int);
			int type = va_arg(vl,int);
			int protocol = va_arg(vl,int);
			ret = socket(domain,type,protocol);
			break;
		}
	case __NR_bind: {
			int s = va_arg(vl,int);
			const struct sockaddr *name = va_arg(vl,struct sockaddr *);
			socklen_t namelen = va_arg(vl,socklen_t);
			ret = bind(s,name,namelen);
			break;
		}
	case __NR_listen: {	
			int s = va_arg(vl,int);
			int backlog = va_arg(vl,int);
			ret = listen(s,backlog);
			break;
		}
	case __NR_accept: {
			int s = va_arg(vl,int);
			struct sockaddr *addr = va_arg(vl,struct sockaddr *);
			socklen_t *addrlen = va_arg(vl,socklen_t*);
			ret = accept(s,addr,addrlen);
			break;
		}
	case __NR_connect: {
			int s = va_arg(vl,int);
			const struct sockaddr *name  =va_arg(vl, struct sockaddr *);
			socklen_t namelen = va_arg(vl,socklen_t);
			ret = connect(s,name,namelen);
			break;
		}
	case __NR_send: {
			int s = va_arg(vl,int);
			const void *data = va_arg(vl,void*);
			size_t size = va_arg(vl,size_t);
			int flags  = va_arg(vl,int);
			ret = send(s,data,size,flags);
			break;
		}
	case __NR_recv: {
			int s = va_arg(vl,int);
			const void *data = va_arg(vl,void*);
			size_t size = va_arg(vl,size_t);
			int flags  = va_arg(vl,int);
			ret = recv(s,data,size,flags);
			break;
		}
	case __NR_closesocket: {
			int s = va_arg(vl,int);
			ret = closesocket(s);
			break;
		}
	default:
		kputs("invalid system call\n");
		ret = -ENOSYS;
		break;
	};

	va_end(vl);

	return ret;
}