b53f35a809
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>
137 lines
2.4 KiB
C
137 lines
2.4 KiB
C
/*
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* Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL.
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*/
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include <sys/wait.h>
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#include "kern_constants.h"
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#include "net_user.h"
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#include "os.h"
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#include "slirp.h"
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#include "user.h"
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static int slirp_user_init(void *data, void *dev)
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{
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struct slirp_data *pri = data;
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pri->dev = dev;
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return 0;
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}
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struct slirp_pre_exec_data {
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int stdin;
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int stdout;
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};
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static void slirp_pre_exec(void *arg)
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{
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struct slirp_pre_exec_data *data = arg;
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if (data->stdin != -1)
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dup2(data->stdin, 0);
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if (data->stdout != -1)
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dup2(data->stdout, 1);
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}
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static int slirp_tramp(char **argv, int fd)
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{
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struct slirp_pre_exec_data pe_data;
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int pid;
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pe_data.stdin = fd;
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pe_data.stdout = fd;
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pid = run_helper(slirp_pre_exec, &pe_data, argv);
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return pid;
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}
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static int slirp_open(void *data)
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{
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struct slirp_data *pri = data;
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int fds[2], pid, err;
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err = os_pipe(fds, 1, 1);
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if (err)
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return err;
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err = slirp_tramp(pri->argw.argv, fds[1]);
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if (err < 0) {
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printk(UM_KERN_ERR "slirp_tramp failed - errno = %d\n", -err);
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goto out;
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}
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pid = err;
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pri->slave = fds[1];
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pri->slip.pos = 0;
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pri->slip.esc = 0;
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pri->pid = err;
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return fds[0];
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out:
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close(fds[0]);
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close(fds[1]);
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return err;
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}
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static void slirp_close(int fd, void *data)
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{
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struct slirp_data *pri = data;
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int status,err;
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close(fd);
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close(pri->slave);
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pri->slave = -1;
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if (pri->pid<1) {
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printk(UM_KERN_ERR "slirp_close: no child process to shut "
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"down\n");
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return;
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}
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#if 0
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if (kill(pri->pid, SIGHUP)<0) {
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printk(UM_KERN_ERR "slirp_close: sending hangup to %d failed "
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"(%d)\n", pri->pid, errno);
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}
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#endif
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CATCH_EINTR(err = waitpid(pri->pid, &status, WNOHANG));
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if (err < 0) {
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printk(UM_KERN_ERR "slirp_close: waitpid returned %d\n", errno);
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return;
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}
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if (err == 0) {
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printk(UM_KERN_ERR "slirp_close: process %d has not exited\n",
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pri->pid);
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return;
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}
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pri->pid = -1;
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}
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int slirp_user_read(int fd, void *buf, int len, struct slirp_data *pri)
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{
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return slip_proto_read(fd, buf, len, &pri->slip);
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}
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int slirp_user_write(int fd, void *buf, int len, struct slirp_data *pri)
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{
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return slip_proto_write(fd, buf, len, &pri->slip);
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}
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const struct net_user_info slirp_user_info = {
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.init = slirp_user_init,
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.open = slirp_open,
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.close = slirp_close,
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.remove = NULL,
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.add_address = NULL,
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.delete_address = NULL,
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.mtu = BUF_SIZE,
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.max_packet = BUF_SIZE,
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};
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