arch/um/drivers/slip_kern.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4  */
   5
   6 #include <linux/if_arp.h>
   7 #include <linux/init.h>
   8 #include <linux/netdevice.h>
   9 #include <net_kern.h>
  10 #include "slip.h"
  11
  12 struct slip_init {
  13         char *gate_addr;
  14 };
  15
  16 static void slip_init(struct net_device *dev, void *data)
  17 {
  18         struct uml_net_private *private;
  19         struct slip_data *spri;
  20         struct slip_init *init = data;
  21
  22         private = netdev_priv(dev);
  23         spri = (struct slip_data *) private->user;
  24
  25         memset(spri->name, 0, sizeof(spri->name));
  26         spri->addr = NULL;
  27         spri->gate_addr = init->gate_addr;
  28         spri->slave = -1;
  29         spri->dev = dev;
  30
  31         slip_proto_init(&spri->slip);
  32
  33         dev->hard_header_len = 0;
  34         dev->header_ops = NULL;
  35         dev->addr_len = 0;
  36         dev->type = ARPHRD_SLIP;
  37         dev->tx_queue_len = 256;
  38         dev->flags = IFF_NOARP;
  39         printk("SLIP backend - SLIP IP = %s\n", spri->gate_addr);
  40 }
  41
  42 static unsigned short slip_protocol(struct sk_buff *skbuff)
  43 {
  44         return htons(ETH_P_IP);
  45 }
  46
  47 static int slip_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
  48 {
  49         return slip_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
  50                               (struct slip_data *) &lp->user);
  51 }
  52
  53 static int slip_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
  54 {
  55         return slip_user_write(fd, skb->data, skb->len,
  56                                (struct slip_data *) &lp->user);
  57 }
  58
  59 static const struct net_kern_info slip_kern_info = {
  60         .init                   = slip_init,
  61         .protocol               = slip_protocol,
  62         .read                   = slip_read,
  63         .write                  = slip_write,
  64 };
  65
  66 static int slip_setup(char *str, char **mac_out, void *data)
  67 {
  68         struct slip_init *init = data;
  69
  70         *init = ((struct slip_init) { .gate_addr = NULL });
  71
  72         if (str[0] != '\0')
  73                 init->gate_addr = str;
  74         return 1;
  75 }
  76
  77 static struct transport slip_transport = {
  78         .list           = LIST_HEAD_INIT(slip_transport.list),
  79         .name           = "slip",
  80         .setup          = slip_setup,
  81         .user           = &slip_user_info,
  82         .kern           = &slip_kern_info,
  83         .private_size   = sizeof(struct slip_data),
  84         .setup_size     = sizeof(struct slip_init),
  85 };
  86
  87 static int register_slip(void)
  88 {
  89         register_transport(&slip_transport);
  90         return 0;
  91 }
  92
  93 late_initcall(register_slip);