arch/um/drivers/slirp_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 <linux/string.h>
  10 #include <net_kern.h>
  11 #include <net_user.h>
  12 #include "slirp.h"
  13
  14 struct slirp_init {
  15         struct arg_list_dummy_wrapper argw;  /* XXX should be simpler... */
  16 };
  17
  18 void slirp_init(struct net_device *dev, void *data)
  19 {
  20         struct uml_net_private *private;
  21         struct slirp_data *spri;
  22         struct slirp_init *init = data;
  23         int i;
  24
  25         private = netdev_priv(dev);
  26         spri = (struct slirp_data *) private->user;
  27
  28         spri->argw = init->argw;
  29         spri->pid = -1;
  30         spri->slave = -1;
  31         spri->dev = dev;
  32
  33         slip_proto_init(&spri->slip);
  34
  35         dev->hard_header_len = 0;
  36         dev->header_ops = NULL;
  37         dev->addr_len = 0;
  38         dev->type = ARPHRD_SLIP;
  39         dev->tx_queue_len = 256;
  40         dev->flags = IFF_NOARP;
  41         printk("SLIRP backend - command line:");
  42         for (i = 0; spri->argw.argv[i] != NULL; i++)
  43                 printk(" '%s'",spri->argw.argv[i]);
  44         printk("\n");
  45 }
  46
  47 static unsigned short slirp_protocol(struct sk_buff *skbuff)
  48 {
  49         return htons(ETH_P_IP);
  50 }
  51
  52 static int slirp_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
  53 {
  54         return slirp_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
  55                                (struct slirp_data *) &lp->user);
  56 }
  57
  58 static int slirp_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
  59 {
  60         return slirp_user_write(fd, skb->data, skb->len,
  61                                 (struct slirp_data *) &lp->user);
  62 }
  63
  64 const struct net_kern_info slirp_kern_info = {
  65         .init                   = slirp_init,
  66         .protocol               = slirp_protocol,
  67         .read                   = slirp_read,
  68         .write                  = slirp_write,
  69 };
  70
  71 static int slirp_setup(char *str, char **mac_out, void *data)
  72 {
  73         struct slirp_init *init = data;
  74         int i=0;
  75
  76         *init = ((struct slirp_init) { .argw = { { "slirp", NULL  } } });
  77
  78         str = split_if_spec(str, mac_out, NULL);
  79
  80         if (str == NULL) /* no command line given after MAC addr */
  81                 return 1;
  82
  83         do {
  84                 if (i >= SLIRP_MAX_ARGS - 1) {
  85                         printk(KERN_WARNING "slirp_setup: truncating slirp "
  86                                "arguments\n");
  87                         break;
  88                 }
  89                 init->argw.argv[i++] = str;
  90                 while(*str && *str!=',') {
  91                         if (*str == '_')
  92                                 *str=' ';
  93                         str++;
  94                 }
  95                 if (*str != ',')
  96                         break;
  97                 *str++ = '\0';
  98         } while (1);
  99
 100         init->argw.argv[i] = NULL;
 101         return 1;
 102 }
 103
 104 static struct transport slirp_transport = {
 105         .list           = LIST_HEAD_INIT(slirp_transport.list),
 106         .name           = "slirp",
 107         .setup          = slirp_setup,
 108         .user           = &slirp_user_info,
 109         .kern           = &slirp_kern_info,
 110         .private_size   = sizeof(struct slirp_data),
 111         .setup_size     = sizeof(struct slirp_init),
 112 };
 113
 114 static int register_slirp(void)
 115 {
 116         register_transport(&slirp_transport);
 117         return 0;
 118 }
 119
 120 late_initcall(register_slirp);