arch/um/drivers/slip_user.c

   1 /*
   2  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL.
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <errno.h>
  10 #include <fcntl.h>
  11 #include <string.h>
  12 #include <sys/termios.h>
  13 #include <sys/wait.h>
  14 #include "kern_constants.h"
  15 #include "net_user.h"
  16 #include "os.h"
  17 #include "slip.h"
  18 #include "um_malloc.h"
  19 #include "user.h"
  20
  21 static int slip_user_init(void *data, void *dev)
  22 {
  23         struct slip_data *pri = data;
  24
  25         pri->dev = dev;
  26         return 0;
  27 }
  28
  29 static int set_up_tty(int fd)
  30 {
  31         int i;
  32         struct termios tios;
  33
  34         if (tcgetattr(fd, &tios) < 0) {
  35                 printk(UM_KERN_ERR "could not get initial terminal "
  36                        "attributes\n");
  37                 return -1;
  38         }
  39
  40         tios.c_cflag = CS8 | CREAD | HUPCL | CLOCAL;
  41         tios.c_iflag = IGNBRK | IGNPAR;
  42         tios.c_oflag = 0;
  43         tios.c_lflag = 0;
  44         for (i = 0; i < NCCS; i++)
  45                 tios.c_cc[i] = 0;
  46         tios.c_cc[VMIN] = 1;
  47         tios.c_cc[VTIME] = 0;
  48
  49         cfsetospeed(&tios, B38400);
  50         cfsetispeed(&tios, B38400);
  51
  52         if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
  53                 printk(UM_KERN_ERR "failed to set terminal attributes\n");
  54                 return -1;
  55         }
  56         return 0;
  57 }
  58
  59 struct slip_pre_exec_data {
  60         int stdin;
  61         int stdout;
  62         int close_me;
  63 };
  64
  65 static void slip_pre_exec(void *arg)
  66 {
  67         struct slip_pre_exec_data *data = arg;
  68
  69         if (data->stdin >= 0)
  70                 dup2(data->stdin, 0);
  71         dup2(data->stdout, 1);
  72         if (data->close_me >= 0)
  73                 close(data->close_me);
  74 }
  75
  76 static int slip_tramp(char **argv, int fd)
  77 {
  78         struct slip_pre_exec_data pe_data;
  79         char *output;
  80         int pid, fds[2], err, output_len;
  81
  82         err = os_pipe(fds, 1, 0);
  83         if (err < 0) {
  84                 printk(UM_KERN_ERR "slip_tramp : pipe failed, err = %d\n",
  85                        -err);
  86                 goto out;
  87         }
  88
  89         err = 0;
  90         pe_data.stdin = fd;
  91         pe_data.stdout = fds[1];
  92         pe_data.close_me = fds[0];
  93         err = run_helper(slip_pre_exec, &pe_data, argv);
  94         if (err < 0)
  95                 goto out_close;
  96         pid = err;
  97
  98         output_len = UM_KERN_PAGE_SIZE;
  99         output = kmalloc(output_len, UM_GFP_KERNEL);
 100         if (output == NULL) {
 101                 printk(UM_KERN_ERR "slip_tramp : failed to allocate output "
 102                        "buffer\n");
 103                 os_kill_process(pid, 1);
 104                 err = -ENOMEM;
 105                 goto out_free;
 106         }
 107
 108         close(fds[1]);
 109         read_output(fds[0], output, output_len);
 110         printk("%s", output);
 111
 112         err = helper_wait(pid, 0, argv[0]);
 113         close(fds[0]);
 114
 115 out_free:
 116         kfree(output);
 117         return err;
 118
 119 out_close:
 120         close(fds[0]);
 121         close(fds[1]);
 122 out:
 123         return err;
 124 }
 125
 126 static int slip_open(void *data)
 127 {
 128         struct slip_data *pri = data;
 129         char version_buf[sizeof("nnnnn\0")];
 130         char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
 131         char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
 132                          NULL };
 133         int sfd, mfd, err;
 134
 135         err = get_pty();
 136         if (err < 0) {
 137                 printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d\n",
 138                        -err);
 139                 goto out;
 140         }
 141         mfd = err;
 142
 143         err = open(ptsname(mfd), O_RDWR, 0);
 144         if (err < 0) {
 145                 printk(UM_KERN_ERR "Couldn't open tty for slip line, "
 146                        "err = %d\n", -err);
 147                 goto out_close;
 148         }
 149         sfd = err;
 150
 151         if (set_up_tty(sfd))
 152                 goto out_close2;
 153
 154         pri->slave = sfd;
 155         pri->slip.pos = 0;
 156         pri->slip.esc = 0;
 157         if (pri->gate_addr != NULL) {
 158                 sprintf(version_buf, "%d", UML_NET_VERSION);
 159                 strcpy(gate_buf, pri->gate_addr);
 160
 161                 err = slip_tramp(argv, sfd);
 162
 163                 if (err < 0) {
 164                         printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
 165                                -err);
 166                         goto out_close2;
 167                 }
 168                 err = os_get_ifname(pri->slave, pri->name);
 169                 if (err < 0) {
 170                         printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
 171                                -err);
 172                         goto out_close2;
 173                 }
 174                 iter_addresses(pri->dev, open_addr, pri->name);
 175         }
 176         else {
 177                 err = os_set_slip(sfd);
 178                 if (err < 0) {
 179                         printk(UM_KERN_ERR "Failed to set slip discipline "
 180                                "encapsulation - err = %d\n", -err);
 181                         goto out_close2;
 182                 }
 183         }
 184         return mfd;
 185 out_close2:
 186         close(sfd);
 187 out_close:
 188         close(mfd);
 189 out:
 190         return err;
 191 }
 192
 193 static void slip_close(int fd, void *data)
 194 {
 195         struct slip_data *pri = data;
 196         char version_buf[sizeof("nnnnn\0")];
 197         char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
 198                          NULL };
 199         int err;
 200
 201         if (pri->gate_addr != NULL)
 202                 iter_addresses(pri->dev, close_addr, pri->name);
 203
 204         sprintf(version_buf, "%d", UML_NET_VERSION);
 205
 206         err = slip_tramp(argv, pri->slave);
 207
 208         if (err != 0)
 209                 printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
 210         close(fd);
 211         close(pri->slave);
 212         pri->slave = -1;
 213 }
 214
 215 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
 216 {
 217         return slip_proto_read(fd, buf, len, &pri->slip);
 218 }
 219
 220 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
 221 {
 222         return slip_proto_write(fd, buf, len, &pri->slip);
 223 }
 224
 225 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
 226                           void *data)
 227 {
 228         struct slip_data *pri = data;
 229
 230         if (pri->slave < 0)
 231                 return;
 232         open_addr(addr, netmask, pri->name);
 233 }
 234
 235 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
 236                             void *data)
 237 {
 238         struct slip_data *pri = data;
 239
 240         if (pri->slave < 0)
 241                 return;
 242         close_addr(addr, netmask, pri->name);
 243 }
 244
 245 const struct net_user_info slip_user_info = {
 246         .init           = slip_user_init,
 247         .open           = slip_open,
 248         .close          = slip_close,
 249         .remove         = NULL,
 250         .add_address    = slip_add_addr,
 251         .delete_address = slip_del_addr,
 252         .mtu            = BUF_SIZE,
 253         .max_packet     = BUF_SIZE,
 254 };