arch/um/os-Linux/drivers/tuntap_user.c

   1 /*
   2  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <stddef.h>
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10 #include <errno.h>
  11 #include <fcntl.h>
  12 #include <sys/wait.h>
  13 #include <sys/socket.h>
  14 #include <sys/un.h>
  15 #include <sys/uio.h>
  16 #include <sys/ioctl.h>
  17 #include <net/if.h>
  18 #include <linux/if_tun.h>
  19 #include "net_user.h"
  20 #include "tuntap.h"
  21 #include "kern_util.h"
  22 #include "user.h"
  23 #include "helper.h"
  24 #include "os.h"
  25
  26 #define MAX_PACKET ETH_MAX_PACKET
  27
  28 void tuntap_user_init(void *data, void *dev)
  29 {
  30         struct tuntap_data *pri = data;
  31
  32         pri->dev = dev;
  33 }
  34
  35 static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
  36                             void *data)
  37 {
  38         struct tuntap_data *pri = data;
  39
  40         tap_check_ips(pri->gate_addr, addr);
  41         if((pri->fd == -1) || pri->fixed_config) return;
  42         open_addr(addr, netmask, pri->dev_name);
  43 }
  44
  45 static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
  46                             void *data)
  47 {
  48         struct tuntap_data *pri = data;
  49
  50         if((pri->fd == -1) || pri->fixed_config) return;
  51         close_addr(addr, netmask, pri->dev_name);
  52 }
  53
  54 struct tuntap_pre_exec_data {
  55         int stdout;
  56         int close_me;
  57 };
  58
  59 static void tuntap_pre_exec(void *arg)
  60 {
  61         struct tuntap_pre_exec_data *data = arg;
  62
  63         dup2(data->stdout, 1);
  64         close(data->close_me);
  65 }
  66
  67 static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
  68                              char *buffer, int buffer_len, int *used_out)
  69 {
  70         struct tuntap_pre_exec_data data;
  71         char version_buf[sizeof("nnnnn\0")];
  72         char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
  73                          NULL };
  74         char buf[CMSG_SPACE(sizeof(*fd_out))];
  75         struct msghdr msg;
  76         struct cmsghdr *cmsg;
  77         struct iovec iov;
  78         int pid, n;
  79
  80         sprintf(version_buf, "%d", UML_NET_VERSION);
  81
  82         data.stdout = remote;
  83         data.close_me = me;
  84
  85         pid = run_helper(tuntap_pre_exec, &data, argv, NULL);
  86
  87         if(pid < 0) return(-pid);
  88
  89         close(remote);
  90
  91         msg.msg_name = NULL;
  92         msg.msg_namelen = 0;
  93         if(buffer != NULL){
  94                 iov = ((struct iovec) { buffer, buffer_len });
  95                 msg.msg_iov = &iov;
  96                 msg.msg_iovlen = 1;
  97         }
  98         else {
  99                 msg.msg_iov = NULL;
 100                 msg.msg_iovlen = 0;
 101         }
 102         msg.msg_control = buf;
 103         msg.msg_controllen = sizeof(buf);
 104         msg.msg_flags = 0;
 105         n = recvmsg(me, &msg, 0);
 106         *used_out = n;
 107         if(n < 0){
 108                 printk("tuntap_open_tramp : recvmsg failed - errno = %d\n",
 109                        errno);
 110                 return(errno);
 111         }
 112         waitpid(pid, NULL, 0);
 113
 114         cmsg = CMSG_FIRSTHDR(&msg);
 115         if(cmsg == NULL){
 116                 printk("tuntap_open_tramp : didn't receive a message\n");
 117                 return(EINVAL);
 118         }
 119         if((cmsg->cmsg_level != SOL_SOCKET) ||
 120            (cmsg->cmsg_type != SCM_RIGHTS)){
 121                 printk("tuntap_open_tramp : didn't receive a descriptor\n");
 122                 return(EINVAL);
 123         }
 124         *fd_out = ((int *) CMSG_DATA(cmsg))[0];
 125         return(0);
 126 }
 127
 128 static int tuntap_open(void *data)
 129 {
 130         struct ifreq ifr;
 131         struct tuntap_data *pri = data;
 132         char *output, *buffer;
 133         int err, fds[2], len, used;
 134
 135         err = tap_open_common(pri->dev, pri->gate_addr);
 136         if(err) return(err);
 137
 138         if(pri->fixed_config){
 139                 if((pri->fd = open("/dev/net/tun", O_RDWR)) < 0){
 140                         printk("Failed to open /dev/net/tun, errno = %d\n",
 141                                errno);
 142                         return(-errno);
 143                 }
 144                 memset(&ifr, 0, sizeof(ifr));
 145                 ifr.ifr_flags = IFF_TAP;
 146                 strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
 147                 if(ioctl(pri->fd, TUNSETIFF, (void *) &ifr) < 0){
 148                         printk("TUNSETIFF failed, errno = %d", errno);
 149                         close(pri->fd);
 150                         return(-errno);
 151                 }
 152         }
 153         else {
 154                 err = os_pipe(fds, 0, 0);
 155                 if(err){
 156                         printk("tuntap_open : os_pipe failed - errno = %d\n",
 157                                -err);
 158                         return(err);
 159                 }
 160
 161                 buffer = get_output_buffer(&len);
 162                 if(buffer != NULL) len--;
 163                 used = 0;
 164
 165                 err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
 166                                         fds[1], buffer, len, &used);
 167
 168                 output = buffer;
 169                 if(err == 0){
 170                         pri->dev_name = uml_strdup(buffer);
 171                         output += IFNAMSIZ;
 172                         printk(output);
 173                         free_output_buffer(buffer);
 174                 }
 175                 else {
 176                         printk(output);
 177                         free_output_buffer(buffer);
 178                         printk("tuntap_open_tramp failed - errno = %d\n", err);
 179                         return(-err);
 180                 }
 181                 close(fds[0]);
 182                 iter_addresses(pri->dev, open_addr, pri->dev_name);
 183         }
 184
 185         return(pri->fd);
 186 }
 187
 188 static void tuntap_close(int fd, void *data)
 189 {
 190         struct tuntap_data *pri = data;
 191
 192         if(!pri->fixed_config)
 193                 iter_addresses(pri->dev, close_addr, pri->dev_name);
 194         close(fd);
 195         pri->fd = -1;
 196 }
 197
 198 static int tuntap_set_mtu(int mtu, void *data)
 199 {
 200         return(mtu);
 201 }
 202
 203 struct net_user_info tuntap_user_info = {
 204         .init           = tuntap_user_init,
 205         .open           = tuntap_open,
 206         .close          = tuntap_close,
 207         .remove         = NULL,
 208         .set_mtu        = tuntap_set_mtu,
 209         .add_address    = tuntap_add_addr,
 210         .delete_address = tuntap_del_addr,
 211         .max_packet     = MAX_PACKET
 212 };
 213
 214 /*
 215  * Overrides for Emacs so that we follow Linus's tabbing style.
 216  * Emacs will notice this stuff at the end of the file and automatically
 217  * adjust the settings for this buffer only.  This must remain at the end
 218  * of the file.
 219  * ---------------------------------------------------------------------------
 220  * Local variables:
 221  * c-file-style: "linux"
 222  * End:
 223  */