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