android_kernel_xiaomi_sm8350/arch/um/drivers/slip_user.c
Jeff Dike b53f35a809 uml: network driver MTU cleanups
A bunch of MTU-related cleanups in the network code.

First, there is the addition of the notion of a maximally-sized packet, which
is the MTU plus headers.  This is used to size the skb that will receive a
packet.  This allows ether_adjust_skb to go away, as it was used to resize the
skb after it was allocated.

Since the skb passed into the low-level read routine is no longer resized, and
possibly reallocated, there, they (and the write routines) don't need to get
an sk_buff **.  They just need the sk_buff * now.  The callers of
ether_adjust_skb still need to do the skb_put, so that's now inlined.

The MAX_PACKET definitions in most of the drivers are gone.

The set_mtu methods were all the same and did nothing, so they can be
removed.

The ethertap driver had a typo which doubled the size of the packet rather
than adding two bytes to it.  It also wasn't defining its setup_size, causing
a zero-byte kmalloc and crash when the invalid pointer returned from kmalloc
was dereferenced.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00

263 lines
5.2 KiB
C

/*
* Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/termios.h>
#include <sys/wait.h>
#include "kern_constants.h"
#include "net_user.h"
#include "os.h"
#include "slip.h"
#include "um_malloc.h"
#include "user.h"
static int slip_user_init(void *data, void *dev)
{
struct slip_data *pri = data;
pri->dev = dev;
return 0;
}
static int set_up_tty(int fd)
{
int i;
struct termios tios;
if (tcgetattr(fd, &tios) < 0) {
printk(UM_KERN_ERR "could not get initial terminal "
"attributes\n");
return -1;
}
tios.c_cflag = CS8 | CREAD | HUPCL | CLOCAL;
tios.c_iflag = IGNBRK | IGNPAR;
tios.c_oflag = 0;
tios.c_lflag = 0;
for (i = 0; i < NCCS; i++)
tios.c_cc[i] = 0;
tios.c_cc[VMIN] = 1;
tios.c_cc[VTIME] = 0;
cfsetospeed(&tios, B38400);
cfsetispeed(&tios, B38400);
if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
printk(UM_KERN_ERR "failed to set terminal attributes\n");
return -1;
}
return 0;
}
struct slip_pre_exec_data {
int stdin;
int stdout;
int close_me;
};
static void slip_pre_exec(void *arg)
{
struct slip_pre_exec_data *data = arg;
if (data->stdin >= 0)
dup2(data->stdin, 0);
dup2(data->stdout, 1);
if (data->close_me >= 0)
close(data->close_me);
}
static int slip_tramp(char **argv, int fd)
{
struct slip_pre_exec_data pe_data;
char *output;
int status, pid, fds[2], err, output_len;
err = os_pipe(fds, 1, 0);
if (err < 0) {
printk(UM_KERN_ERR "slip_tramp : pipe failed, err = %d\n",
-err);
goto out;
}
err = 0;
pe_data.stdin = fd;
pe_data.stdout = fds[1];
pe_data.close_me = fds[0];
err = run_helper(slip_pre_exec, &pe_data, argv);
if (err < 0)
goto out_close;
pid = err;
output_len = UM_KERN_PAGE_SIZE;
output = kmalloc(output_len, UM_GFP_KERNEL);
if (output == NULL) {
printk(UM_KERN_ERR "slip_tramp : failed to allocate output "
"buffer\n");
os_kill_process(pid, 1);
err = -ENOMEM;
goto out_free;
}
close(fds[1]);
read_output(fds[0], output, output_len);
printk("%s", output);
CATCH_EINTR(err = waitpid(pid, &status, 0));
if (err < 0)
err = errno;
else if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
printk(UM_KERN_ERR "'%s' didn't exit with status 0\n", argv[0]);
err = -EINVAL;
}
else err = 0;
close(fds[0]);
out_free:
kfree(output);
return err;
out_close:
close(fds[0]);
close(fds[1]);
out:
return err;
}
static int slip_open(void *data)
{
struct slip_data *pri = data;
char version_buf[sizeof("nnnnn\0")];
char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
NULL };
int sfd, mfd, err;
err = get_pty();
if (err < 0) {
printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d\n",
-err);
goto out;
}
mfd = err;
err = open(ptsname(mfd), O_RDWR, 0);
if (err < 0) {
printk(UM_KERN_ERR "Couldn't open tty for slip line, "
"err = %d\n", -err);
goto out_close;
}
sfd = err;
if (set_up_tty(sfd))
goto out_close2;
pri->slave = sfd;
pri->slip.pos = 0;
pri->slip.esc = 0;
if (pri->gate_addr != NULL) {
sprintf(version_buf, "%d", UML_NET_VERSION);
strcpy(gate_buf, pri->gate_addr);
err = slip_tramp(argv, sfd);
if (err < 0) {
printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
-err);
goto out_close2;
}
err = os_get_ifname(pri->slave, pri->name);
if (err < 0) {
printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
-err);
goto out_close2;
}
iter_addresses(pri->dev, open_addr, pri->name);
}
else {
err = os_set_slip(sfd);
if (err < 0) {
printk(UM_KERN_ERR "Failed to set slip discipline "
"encapsulation - err = %d\n", -err);
goto out_close2;
}
}
return mfd;
out_close2:
close(sfd);
out_close:
close(mfd);
out:
return err;
}
static void slip_close(int fd, void *data)
{
struct slip_data *pri = data;
char version_buf[sizeof("nnnnn\0")];
char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
NULL };
int err;
if (pri->gate_addr != NULL)
iter_addresses(pri->dev, close_addr, pri->name);
sprintf(version_buf, "%d", UML_NET_VERSION);
err = slip_tramp(argv, pri->slave);
if (err != 0)
printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
close(fd);
close(pri->slave);
pri->slave = -1;
}
int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
{
return slip_proto_read(fd, buf, len, &pri->slip);
}
int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
{
return slip_proto_write(fd, buf, len, &pri->slip);
}
static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
void *data)
{
struct slip_data *pri = data;
if (pri->slave < 0)
return;
open_addr(addr, netmask, pri->name);
}
static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
void *data)
{
struct slip_data *pri = data;
if (pri->slave < 0)
return;
close_addr(addr, netmask, pri->name);
}
const struct net_user_info slip_user_info = {
.init = slip_user_init,
.open = slip_open,
.close = slip_close,
.remove = NULL,
.add_address = slip_add_addr,
.delete_address = slip_del_addr,
.mtu = BUF_SIZE,
.max_packet = BUF_SIZE,
};