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

   1 /*
   2  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
   3  * James Leu (jleu@mindspring.net).
   4  * Copyright (C) 2001 by various other people who didn't put their name here.
   5  * Licensed under the GPL.
   6  */
   7
   8 #include <stdio.h>
   9 #include <unistd.h>
  10 #include <stddef.h>
  11 #include <stdlib.h>
  12 #include <sys/errno.h>
  13 #include <sys/socket.h>
  14 #include <sys/wait.h>
  15 #include <sys/un.h>
  16 #include <net/if.h>
  17 #include "user.h"
  18 #include "kern_util.h"
  19 #include "net_user.h"
  20 #include "etap.h"
  21 #include "os.h"
  22 #include "um_malloc.h"
  23 #include "kern_constants.h"
  24
  25 #define MAX_PACKET ETH_MAX_PACKET
  26
  27 static int etap_user_init(void *data, void *dev)
  28 {
  29         struct ethertap_data *pri = data;
  30
  31         pri->dev = dev;
  32         return 0;
  33 }
  34
  35 struct addr_change {
  36         enum { ADD_ADDR, DEL_ADDR } what;
  37         unsigned char addr[4];
  38         unsigned char netmask[4];
  39 };
  40
  41 static void etap_change(int op, unsigned char *addr, unsigned char *netmask,
  42                         int fd)
  43 {
  44         struct addr_change change;
  45         char *output;
  46         int n;
  47
  48         change.what = op;
  49         memcpy(change.addr, addr, sizeof(change.addr));
  50         memcpy(change.netmask, netmask, sizeof(change.netmask));
  51         CATCH_EINTR(n = write(fd, &change, sizeof(change)));
  52         if(n != sizeof(change)){
  53                 printk("etap_change - request failed, err = %d\n", errno);
  54                 return;
  55         }
  56
  57         output = um_kmalloc(UM_KERN_PAGE_SIZE);
  58         if(output == NULL)
  59                 printk("etap_change : Failed to allocate output buffer\n");
  60         read_output(fd, output, UM_KERN_PAGE_SIZE);
  61         if(output != NULL){
  62                 printk("%s", output);
  63                 kfree(output);
  64         }
  65 }
  66
  67 static void etap_open_addr(unsigned char *addr, unsigned char *netmask,
  68                            void *arg)
  69 {
  70         etap_change(ADD_ADDR, addr, netmask, *((int *) arg));
  71 }
  72
  73 static void etap_close_addr(unsigned char *addr, unsigned char *netmask,
  74                             void *arg)
  75 {
  76         etap_change(DEL_ADDR, addr, netmask, *((int *) arg));
  77 }
  78
  79 struct etap_pre_exec_data {
  80         int control_remote;
  81         int control_me;
  82         int data_me;
  83 };
  84
  85 static void etap_pre_exec(void *arg)
  86 {
  87         struct etap_pre_exec_data *data = arg;
  88
  89         dup2(data->control_remote, 1);
  90         os_close_file(data->data_me);
  91         os_close_file(data->control_me);
  92 }
  93
  94 static int etap_tramp(char *dev, char *gate, int control_me,
  95                       int control_remote, int data_me, int data_remote)
  96 {
  97         struct etap_pre_exec_data pe_data;
  98         int pid, status, err, n;
  99         char version_buf[sizeof("nnnnn\0")];
 100         char data_fd_buf[sizeof("nnnnnn\0")];
 101         char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
 102         char *setup_args[] = { "uml_net", version_buf, "ethertap", dev,
 103                                data_fd_buf, gate_buf, NULL };
 104         char *nosetup_args[] = { "uml_net", version_buf, "ethertap",
 105                                  dev, data_fd_buf, NULL };
 106         char **args, c;
 107
 108         sprintf(data_fd_buf, "%d", data_remote);
 109         sprintf(version_buf, "%d", UML_NET_VERSION);
 110         if(gate != NULL){
 111                 strcpy(gate_buf, gate);
 112                 args = setup_args;
 113         }
 114         else args = nosetup_args;
 115
 116         err = 0;
 117         pe_data.control_remote = control_remote;
 118         pe_data.control_me = control_me;
 119         pe_data.data_me = data_me;
 120         pid = run_helper(etap_pre_exec, &pe_data, args, NULL);
 121
 122         if(pid < 0)
 123                 err = pid;
 124         os_close_file(data_remote);
 125         os_close_file(control_remote);
 126         CATCH_EINTR(n = read(control_me, &c, sizeof(c)));
 127         if(n != sizeof(c)){
 128                 err = -errno;
 129                 printk("etap_tramp : read of status failed, err = %d\n", -err);
 130                 return err;
 131         }
 132         if(c != 1){
 133                 printk("etap_tramp : uml_net failed\n");
 134                 err = -EINVAL;
 135                 CATCH_EINTR(n = waitpid(pid, &status, 0));
 136                 if(n < 0)
 137                         err = -errno;
 138                 else if(!WIFEXITED(status) || (WEXITSTATUS(status) != 1))
 139                         printk("uml_net didn't exit with status 1\n");
 140         }
 141         return err;
 142 }
 143
 144 static int etap_open(void *data)
 145 {
 146         struct ethertap_data *pri = data;
 147         char *output;
 148         int data_fds[2], control_fds[2], err, output_len;
 149
 150         err = tap_open_common(pri->dev, pri->gate_addr);
 151         if(err)
 152                 return err;
 153
 154         err = os_pipe(data_fds, 0, 0);
 155         if(err < 0){
 156                 printk("data os_pipe failed - err = %d\n", -err);
 157                 return err;
 158         }
 159
 160         err = os_pipe(control_fds, 1, 0);
 161         if(err < 0){
 162                 printk("control os_pipe failed - err = %d\n", -err);
 163                 return err;
 164         }
 165
 166         err = etap_tramp(pri->dev_name, pri->gate_addr, control_fds[0],
 167                          control_fds[1], data_fds[0], data_fds[1]);
 168         output_len = UM_KERN_PAGE_SIZE;
 169         output = um_kmalloc(output_len);
 170         read_output(control_fds[0], output, output_len);
 171
 172         if(output == NULL)
 173                 printk("etap_open : failed to allocate output buffer\n");
 174         else {
 175                 printk("%s", output);
 176                 kfree(output);
 177         }
 178
 179         if(err < 0){
 180                 printk("etap_tramp failed - err = %d\n", -err);
 181                 return err;
 182         }
 183
 184         pri->data_fd = data_fds[0];
 185         pri->control_fd = control_fds[0];
 186         iter_addresses(pri->dev, etap_open_addr, &pri->control_fd);
 187         return data_fds[0];
 188 }
 189
 190 static void etap_close(int fd, void *data)
 191 {
 192         struct ethertap_data *pri = data;
 193
 194         iter_addresses(pri->dev, etap_close_addr, &pri->control_fd);
 195         os_close_file(fd);
 196         os_shutdown_socket(pri->data_fd, 1, 1);
 197         os_close_file(pri->data_fd);
 198         pri->data_fd = -1;
 199         os_close_file(pri->control_fd);
 200         pri->control_fd = -1;
 201 }
 202
 203 static int etap_set_mtu(int mtu, void *data)
 204 {
 205         return mtu;
 206 }
 207
 208 static void etap_add_addr(unsigned char *addr, unsigned char *netmask,
 209                           void *data)
 210 {
 211         struct ethertap_data *pri = data;
 212
 213         tap_check_ips(pri->gate_addr, addr);
 214         if(pri->control_fd == -1)
 215                 return;
 216         etap_open_addr(addr, netmask, &pri->control_fd);
 217 }
 218
 219 static void etap_del_addr(unsigned char *addr, unsigned char *netmask,
 220                           void *data)
 221 {
 222         struct ethertap_data *pri = data;
 223
 224         if(pri->control_fd == -1)
 225                 return;
 226         etap_close_addr(addr, netmask, &pri->control_fd);
 227 }
 228
 229 const struct net_user_info ethertap_user_info = {
 230         .init           = etap_user_init,
 231         .open           = etap_open,
 232         .close          = etap_close,
 233         .remove         = NULL,
 234         .set_mtu        = etap_set_mtu,
 235         .add_address    = etap_add_addr,
 236         .delete_address = etap_del_addr,
 237         .max_packet     = MAX_PACKET - ETH_HEADER_ETHERTAP
 238 };