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_util.h"
  22 #include "user.h"
  23 #include "os.h"
  24
  25 #define MAX_PACKET ETH_MAX_PACKET
  26
  27 void tuntap_user_init(void *data, void *dev)
  28 {
  29         struct tuntap_data *pri = data;
  30
  31         pri->dev = dev;
  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) return;
  41         open_addr(addr, netmask, pri->dev_name);
  42 }
  43
  44 static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
  45                             void *data)
  46 {
  47         struct tuntap_data *pri = data;
  48
  49         if((pri->fd == -1) || pri->fixed_config) return;
  50         close_addr(addr, netmask, pri->dev_name);
  51 }
  52
  53 struct tuntap_pre_exec_data {
  54         int stdout;
  55         int close_me;
  56 };
  57
  58 static void tuntap_pre_exec(void *arg)
  59 {
  60         struct tuntap_pre_exec_data *data = arg;
  61
  62         dup2(data->stdout, 1);
  63         os_close_file(data->close_me);
  64 }
  65
  66 static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
  67                              char *buffer, int buffer_len, int *used_out)
  68 {
  69         struct tuntap_pre_exec_data data;
  70         char version_buf[sizeof("nnnnn\0")];
  71         char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
  72                          NULL };
  73         char buf[CMSG_SPACE(sizeof(*fd_out))];
  74         struct msghdr msg;
  75         struct cmsghdr *cmsg;
  76         struct iovec iov;
  77         int pid, n, err;
  78
  79         sprintf(version_buf, "%d", UML_NET_VERSION);
  80
  81         data.stdout = remote;
  82         data.close_me = me;
  83
  84         pid = run_helper(tuntap_pre_exec, &data, argv, NULL);
  85
  86         if(pid < 0) return(-pid);
  87
  88         os_close_file(remote);
  89
  90         msg.msg_name = NULL;
  91         msg.msg_namelen = 0;
  92         if(buffer != NULL){
  93                 iov = ((struct iovec) { buffer, buffer_len });
  94                 msg.msg_iov = &iov;
  95                 msg.msg_iovlen = 1;
  96         }
  97         else {
  98                 msg.msg_iov = NULL;
  99                 msg.msg_iovlen = 0;
 100         }
 101         msg.msg_control = buf;
 102         msg.msg_controllen = sizeof(buf);
 103         msg.msg_flags = 0;
 104         n = recvmsg(me, &msg, 0);
 105         *used_out = n;
 106         if(n < 0){
 107                 err = -errno;
 108                 printk("tuntap_open_tramp : recvmsg failed - errno = %d\n",
 109                        errno);
 110                 return err;
 111         }
 112         CATCH_EINTR(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         os_set_exec_close(*fd_out, 1);
 126         return(0);
 127 }
 128
 129 static int tuntap_open(void *data)
 130 {
 131         struct ifreq ifr;
 132         struct tuntap_data *pri = data;
 133         char *output, *buffer;
 134         int err, fds[2], len, used;
 135
 136         err = tap_open_common(pri->dev, pri->gate_addr);
 137         if(err < 0)
 138                 return(err);
 139
 140         if(pri->fixed_config){
 141                 pri->fd = os_open_file("/dev/net/tun",
 142                                        of_cloexec(of_rdwr(OPENFLAGS())), 0);
 143                 if(pri->fd < 0){
 144                         printk("Failed to open /dev/net/tun, err = %d\n",
 145                                -pri->fd);
 146                         return(pri->fd);
 147                 }
 148                 memset(&ifr, 0, sizeof(ifr));
 149                 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
 150                 strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
 151                 if(ioctl(pri->fd, TUNSETIFF, (void *) &ifr) < 0){
 152                         err = -errno;
 153                         printk("TUNSETIFF failed, errno = %d\n", errno);
 154                         os_close_file(pri->fd);
 155                         return err;
 156                 }
 157         }
 158         else {
 159                 err = os_pipe(fds, 0, 0);
 160                 if(err < 0){
 161                         printk("tuntap_open : os_pipe failed - err = %d\n",
 162                                -err);
 163                         return(err);
 164                 }
 165
 166                 buffer = get_output_buffer(&len);
 167                 if(buffer != NULL) len--;
 168                 used = 0;
 169
 170                 err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
 171                                         fds[1], buffer, len, &used);
 172
 173                 output = buffer;
 174                 if(err < 0) {
 175                         printk("%s", output);
 176                         free_output_buffer(buffer);
 177                         printk("tuntap_open_tramp failed - err = %d\n", -err);
 178                         return(err);
 179                 }
 180
 181                 pri->dev_name = uml_strdup(buffer);
 182                 output += IFNAMSIZ;
 183                 printk("%s", output);
 184                 free_output_buffer(buffer);
 185
 186                 os_close_file(fds[0]);
 187                 iter_addresses(pri->dev, open_addr, pri->dev_name);
 188         }
 189
 190         return(pri->fd);
 191 }
 192
 193 static void tuntap_close(int fd, void *data)
 194 {
 195         struct tuntap_data *pri = data;
 196
 197         if(!pri->fixed_config)
 198                 iter_addresses(pri->dev, close_addr, pri->dev_name);
 199         os_close_file(fd);
 200         pri->fd = -1;
 201 }
 202
 203 static int tuntap_set_mtu(int mtu, void *data)
 204 {
 205         return(mtu);
 206 }
 207
 208 const struct net_user_info tuntap_user_info = {
 209         .init           = tuntap_user_init,
 210         .open           = tuntap_open,
 211         .close          = tuntap_close,
 212         .remove         = NULL,
 213         .set_mtu        = tuntap_set_mtu,
 214         .add_address    = tuntap_add_addr,
 215         .delete_address = tuntap_del_addr,
 216         .max_packet     = MAX_PACKET
 217 };
 218
 219 /*
 220  * Overrides for Emacs so that we follow Linus's tabbing style.
 221  * Emacs will notice this stuff at the end of the file and automatically
 222  * adjust the settings for this buffer only.  This must remain at the end
 223  * of the file.
 224  * ---------------------------------------------------------------------------
 225  * Local variables:
 226  * c-file-style: "linux"
 227  * End:
 228  */