Files
codezero/conts/posix/libposix/read.c
2010-03-25 01:12:40 +02:00

142 lines
2.9 KiB
C

/*
* l4/posix glue for read() / sys_readdir()
*
* Copyright (C) 2007 Bahadir Balban
*/
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <l4lib/ipcdefs.h>
#include <l4lib/os/posix/readdir.h>
#include <l4/macros.h>
#include INC_GLUE(memory.h)
#include INC_GLUE(message.h)
#include <libposix.h>
/*
* TODO:
*
* Do this as follows:
*
* A short ipc l4_send() to indicate request
* An extended l4_receive_extended() to get back extended buffer.
*
* Or do it just like read()
*/
static inline int l4_readdir(int fd, void *buf, size_t count)
{
int cnt, err;
write_mr(L4SYS_ARG0, fd);
write_mr(L4SYS_ARG1, count);
/* Call pager with readdir() request. Check ipc error. */
if ((err = l4_send(pagerid, L4_IPC_TAG_READDIR)) < 0) {
print_err("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);
return err;
}
/* Call pager with readdir() request. Check ipc error. */
if ((err = l4_receive_extended(pagerid,
L4_IPC_EXTENDED_MAX_SIZE,
buf)) < 0) {
print_err("%s: L4 Extended IPC error: %d.\n", __FUNCTION__, err);
return err;
}
/* Check if syscall itself was successful */
if ((cnt = l4_get_retval()) < 0) {
print_err("%s: READDIR Error: %d.\n", __FUNCTION__, (int)cnt);
return cnt;
}
return cnt;
}
#if 0
static inline int l4_readdir(int fd, void *buf, size_t count)
{
int cnt;
write_mr(L4SYS_ARG0, fd);
write_mr(L4SYS_ARG1, (unsigned long)buf);
write_mr(L4SYS_ARG2, count);
/* Call pager with readdir() request. Check ipc error. */
if ((cnt = l4_sendrecv(pagerid, pagerid, L4_IPC_TAG_READDIR)) < 0) {
print_err("%s: L4 IPC Error: %d.\n", __FUNCTION__, cnt);
return cnt;
}
/* Check if syscall itself was successful */
if ((cnt = l4_get_retval()) < 0) {
print_err("%s: READDIR Error: %d.\n", __FUNCTION__, (int)cnt);
return cnt;
}
return cnt;
}
#endif
static inline int l4_read(int fd, void *buf, size_t count)
{
int cnt;
write_mr(L4SYS_ARG0, fd);
write_mr(L4SYS_ARG1, (unsigned long)buf);
write_mr(L4SYS_ARG2, count);
/* Call pager with read() request. Check ipc error. */
if ((cnt = l4_sendrecv(pagerid, pagerid, L4_IPC_TAG_READ)) < 0) {
print_err("%s: L4 IPC Error: %d.\n", __FUNCTION__, cnt);
return cnt;
}
/* Check if syscall itself was successful */
if ((cnt = l4_get_retval()) < 0) {
print_err("%s: READ Error: %d.\n", __FUNCTION__, (int)cnt);
return cnt;
}
return cnt;
}
ssize_t read(int fd, void *buf, size_t count)
{
int ret;
if (!count)
return 0;
ret = l4_read(fd, buf, count);
/* If error, return positive error code */
if (ret < 0) {
errno = -ret;
return -1;
}
/* else return value */
return ret;
}
ssize_t os_readdir(int fd, void *buf, size_t count)
{
int ret;
if (!count)
return 0;
ret = l4_readdir(fd, buf, count);
/* If error, return positive error code */
if (ret < 0) {
errno = -ret;
return -1;
}
/* else return value */
return ret;
}