linux_dsm_epyc7002/arch/um/drivers/slirp_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

137 lines
2.4 KiB
C

/*
* Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL.
*/
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/wait.h>
#include "kern_constants.h"
#include "net_user.h"
#include "os.h"
#include "slirp.h"
#include "user.h"
static int slirp_user_init(void *data, void *dev)
{
struct slirp_data *pri = data;
pri->dev = dev;
return 0;
}
struct slirp_pre_exec_data {
int stdin;
int stdout;
};
static void slirp_pre_exec(void *arg)
{
struct slirp_pre_exec_data *data = arg;
if (data->stdin != -1)
dup2(data->stdin, 0);
if (data->stdout != -1)
dup2(data->stdout, 1);
}
static int slirp_tramp(char **argv, int fd)
{
struct slirp_pre_exec_data pe_data;
int pid;
pe_data.stdin = fd;
pe_data.stdout = fd;
pid = run_helper(slirp_pre_exec, &pe_data, argv);
return pid;
}
static int slirp_open(void *data)
{
struct slirp_data *pri = data;
int fds[2], pid, err;
err = os_pipe(fds, 1, 1);
if (err)
return err;
err = slirp_tramp(pri->argw.argv, fds[1]);
if (err < 0) {
printk(UM_KERN_ERR "slirp_tramp failed - errno = %d\n", -err);
goto out;
}
pid = err;
pri->slave = fds[1];
pri->slip.pos = 0;
pri->slip.esc = 0;
pri->pid = err;
return fds[0];
out:
close(fds[0]);
close(fds[1]);
return err;
}
static void slirp_close(int fd, void *data)
{
struct slirp_data *pri = data;
int status,err;
close(fd);
close(pri->slave);
pri->slave = -1;
if (pri->pid<1) {
printk(UM_KERN_ERR "slirp_close: no child process to shut "
"down\n");
return;
}
#if 0
if (kill(pri->pid, SIGHUP)<0) {
printk(UM_KERN_ERR "slirp_close: sending hangup to %d failed "
"(%d)\n", pri->pid, errno);
}
#endif
CATCH_EINTR(err = waitpid(pri->pid, &status, WNOHANG));
if (err < 0) {
printk(UM_KERN_ERR "slirp_close: waitpid returned %d\n", errno);
return;
}
if (err == 0) {
printk(UM_KERN_ERR "slirp_close: process %d has not exited\n",
pri->pid);
return;
}
pri->pid = -1;
}
int slirp_user_read(int fd, void *buf, int len, struct slirp_data *pri)
{
return slip_proto_read(fd, buf, len, &pri->slip);
}
int slirp_user_write(int fd, void *buf, int len, struct slirp_data *pri)
{
return slip_proto_write(fd, buf, len, &pri->slip);
}
const struct net_user_info slirp_user_info = {
.init = slirp_user_init,
.open = slirp_open,
.close = slirp_close,
.remove = NULL,
.add_address = NULL,
.delete_address = NULL,
.mtu = BUF_SIZE,
.max_packet = BUF_SIZE,
};