/*
 *  Copyright (C) 2024 Free Software Foundation
 *
 * This program is free software ; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation ; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY ; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the program ; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <syscalls.h>
#include <testlib.h>

#include <mach/exception.h>
#include <mach/mig_errors.h>
#include <mach/vm_param.h>

#include <mach.user.h>
#include <mach_port.user.h>
#include <exc.server.h>


static struct {
  mach_port_t exception_port;
  mach_port_t thread;
  mach_port_t task;
  integer_t exception;
  integer_t code;
  integer_t subcode;
} last_exc;
kern_return_t catch_exception_raise(mach_port_t exception_port,
                                    mach_port_t thread, mach_port_t task,
                                    integer_t exception, integer_t code,
                                    long_integer_t subcode)
{
  printf("received catch_exception_raise(%u %u %u %d %d %d)\n",
         exception_port, thread, task, exception, code, subcode);
  last_exc.exception_port = exception_port;
  last_exc.thread = thread;
  last_exc.task = task;
  last_exc.exception = exception;
  last_exc.code = code;
  last_exc.subcode = subcode;
  return KERN_SUCCESS;
}

static char simple_request_data[PAGE_SIZE];
static char simple_reply_data[PAGE_SIZE];
int simple_msg_server(boolean_t (*demuxer) (mach_msg_header_t *request,
                                             mach_msg_header_t *reply),
                      mach_port_t rcv_port_name,
                      int num_msgs)
{
  int midx = 0, mok = 0;
  int ret;
  mig_reply_header_t *request = (mig_reply_header_t*)simple_request_data;
  mig_reply_header_t *reply = (mig_reply_header_t*)simple_reply_data;
  while ((midx - num_msgs) < 0)
    {
      ret = mach_msg(&request->Head, MACH_RCV_MSG, 0, PAGE_SIZE,
                     rcv_port_name, 0, MACH_PORT_NULL);
      switch (ret)
        {
        case MACH_MSG_SUCCESS:
          if ((*demuxer)(&request->Head, &reply->Head))
            mok++;  // TODO send reply
          else
            FAILURE("demuxer didn't handle the message");
          break;
        default:
          ASSERT_RET(ret, "receiving in msg_server");
          break;
        }
      midx++;
    }
  if (mok != midx)
    FAILURE("wrong number of message received");
  return mok != midx;
}


void test_syscall_bad_arg_on_stack(void *arg)
{
  /* mach_msg() has 7 arguments, so the last one should be always
     passed on the stack on x86. Here we make ESP/RSP point to the
     wrong place to test the access check */
#ifdef __x86_64__
  asm volatile("movq	$0x123,%rsp;"			\
               "movq	$-25,%rax;"                     \
               "syscall;"                               \
               );
#else
  asm volatile("mov	$0x123,%esp;"			\
               "mov	$-25,%eax;"                     \
               "lcall	$0x7,$0x0;"                     \
               );
#endif
  FAILURE("we shouldn't be here!");
}

void test_bad_syscall_num(void *arg)
{
#ifdef __x86_64__
  asm volatile("movq	$0x123456,%rax;"                \
               "syscall;"                               \
               );
#else
  asm volatile("mov	$0x123456,%eax;"                \
               "lcall	$0x7,$0x0;"                     \
               );
#endif
  FAILURE("we shouldn't be here!");
}


int main(int argc, char *argv[], int envc, char *envp[])
{
  int err;
  mach_port_t excp;

  err = mach_port_allocate(mach_task_self (), MACH_PORT_RIGHT_RECEIVE, &excp);
  ASSERT_RET(err, "creating exception port");

  err = mach_port_insert_right(mach_task_self(), excp, excp,
                               MACH_MSG_TYPE_MAKE_SEND);
  ASSERT_RET(err, "inserting send right into exception port");

  err = task_set_special_port(mach_task_self(), TASK_EXCEPTION_PORT, excp);
  ASSERT_RET(err, "setting task exception port");

  /* FIXME: receiving an exception with small size causes GP on 64 bit userspace */
  /* mig_reply_header_t msg; */
  /* err = mach_msg(&msg.Head,	/\* The header *\/ */
  /*                MACH_RCV_MSG, */
  /*                0, */
  /*                sizeof (msg),	/\* Max receive Size *\/ */
  /*                excp, */
  /*                1000, */
  /*                MACH_PORT_NULL); */

  // FIXME: maybe MIG should provide this prototype?
  boolean_t exc_server
    (mach_msg_header_t *InHeadP, mach_msg_header_t *OutHeadP);

  memset(&last_exc, 0, sizeof(last_exc));
  test_thread_start(mach_task_self(), test_bad_syscall_num, NULL);
  ASSERT_RET(simple_msg_server(exc_server, excp, 1), "error in exc server");
  ASSERT((last_exc.exception == EXC_BAD_INSTRUCTION) && (last_exc.code == EXC_I386_INVOP),
         "bad exception for test_bad_syscall_num()");

  memset(&last_exc, 0, sizeof(last_exc));
  test_thread_start(mach_task_self(), test_syscall_bad_arg_on_stack, NULL);
  ASSERT_RET(simple_msg_server(exc_server, excp, 1), "error in exc server");
  ASSERT((last_exc.exception == EXC_BAD_ACCESS) && (last_exc.code == KERN_INVALID_ADDRESS),
         "bad exception for test_syscall_bad_arg_on_stack()");

  return 0;
}