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 = uml_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_close;
 106         }
 107
 108         close(fds[1]);
 109         read_output(fds[0], output, output_len);
 110         printk("%s", output);
 111
 112         err = helper_wait(pid);
 113         close(fds[0]);
 114
 115         kfree(output);
 116         return err;
 117
 118 out_close:
 119         close(fds[0]);
 120         close(fds[1]);
 121 out:
 122         return err;
 123 }
 124
 125 static int slip_open(void *data)
 126 {
 127         struct slip_data *pri = data;
 128         char version_buf[sizeof("nnnnn\0")];
 129         char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
 130         char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
 131                          NULL };
 132         int sfd, mfd, err;
 133
 134         err = get_pty();
 135         if (err < 0) {
 136                 printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d\n",
 137                        -err);
 138                 goto out;
 139         }
 140         mfd = err;
 141
 142         err = open(ptsname(mfd), O_RDWR, 0);
 143         if (err < 0) {
 144                 printk(UM_KERN_ERR "Couldn't open tty for slip line, "
 145                        "err = %d\n", -err);
 146                 goto out_close;
 147         }
 148         sfd = err;
 149
 150         if (set_up_tty(sfd))
 151                 goto out_close2;
 152
 153         pri->slave = sfd;
 154         pri->slip.pos = 0;
 155         pri->slip.esc = 0;
 156         if (pri->gate_addr != NULL) {
 157                 sprintf(version_buf, "%d", UML_NET_VERSION);
 158                 strcpy(gate_buf, pri->gate_addr);
 159
 160                 err = slip_tramp(argv, sfd);
 161
 162                 if (err < 0) {
 163                         printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
 164                                -err);
 165                         goto out_close2;
 166                 }
 167                 err = os_get_ifname(pri->slave, pri->name);
 168                 if (err < 0) {
 169                         printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
 170                                -err);
 171                         goto out_close2;
 172                 }
 173                 iter_addresses(pri->dev, open_addr, pri->name);
 174         }
 175         else {
 176                 err = os_set_slip(sfd);
 177                 if (err < 0) {
 178                         printk(UM_KERN_ERR "Failed to set slip discipline "
 179                                "encapsulation - err = %d\n", -err);
 180                         goto out_close2;
 181                 }
 182         }
 183         return mfd;
 184 out_close2:
 185         close(sfd);
 186 out_close:
 187         close(mfd);
 188 out:
 189         return err;
 190 }
 191
 192 static void slip_close(int fd, void *data)
 193 {
 194         struct slip_data *pri = data;
 195         char version_buf[sizeof("nnnnn\0")];
 196         char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
 197                          NULL };
 198         int err;
 199
 200         if (pri->gate_addr != NULL)
 201                 iter_addresses(pri->dev, close_addr, pri->name);
 202
 203         sprintf(version_buf, "%d", UML_NET_VERSION);
 204
 205         err = slip_tramp(argv, pri->slave);
 206
 207         if (err != 0)
 208                 printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
 209         close(fd);
 210         close(pri->slave);
 211         pri->slave = -1;
 212 }
 213
 214 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
 215 {
 216         return slip_proto_read(fd, buf, len, &pri->slip);
 217 }
 218
 219 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
 220 {
 221         return slip_proto_write(fd, buf, len, &pri->slip);
 222 }
 223
 224 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
 225                           void *data)
 226 {
 227         struct slip_data *pri = data;
 228
 229         if (pri->slave < 0)
 230                 return;
 231         open_addr(addr, netmask, pri->name);
 232 }
 233
 234 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
 235                             void *data)
 236 {
 237         struct slip_data *pri = data;
 238
 239         if (pri->slave < 0)
 240                 return;
 241         close_addr(addr, netmask, pri->name);
 242 }
 243
 244 const struct net_user_info slip_user_info = {
 245         .init           = slip_user_init,
 246         .open           = slip_open,
 247         .close          = slip_close,
 248         .remove         = NULL,
 249         .add_address    = slip_add_addr,
 250         .delete_address = slip_del_addr,
 251         .mtu            = BUF_SIZE,
 252         .max_packet     = BUF_SIZE,
 253 };