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 status, 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         CATCH_EINTR(err = waitpid(pid, &status, 0));
 113         if (err < 0)
 114                 err = errno;
 115         else if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
 116                 printk(UM_KERN_ERR "'%s' didn't exit with status 0\n", argv[0]);
 117                 err = -EINVAL;
 118         }
 119         else err = 0;
 120
 121         close(fds[0]);
 122
 123 out_free:
 124         kfree(output);
 125         return err;
 126
 127 out_close:
 128         close(fds[0]);
 129         close(fds[1]);
 130 out:
 131         return err;
 132 }
 133
 134 static int slip_open(void *data)
 135 {
 136         struct slip_data *pri = data;
 137         char version_buf[sizeof("nnnnn\0")];
 138         char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
 139         char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
 140                          NULL };
 141         int sfd, mfd, err;
 142
 143         err = get_pty();
 144         if (err < 0) {
 145                 printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d\n",
 146                        -err);
 147                 goto out;
 148         }
 149         mfd = err;
 150
 151         err = open(ptsname(mfd), O_RDWR, 0);
 152         if (err < 0) {
 153                 printk(UM_KERN_ERR "Couldn't open tty for slip line, "
 154                        "err = %d\n", -err);
 155                 goto out_close;
 156         }
 157         sfd = err;
 158
 159         if (set_up_tty(sfd))
 160                 goto out_close2;
 161
 162         pri->slave = sfd;
 163         pri->slip.pos = 0;
 164         pri->slip.esc = 0;
 165         if (pri->gate_addr != NULL) {
 166                 sprintf(version_buf, "%d", UML_NET_VERSION);
 167                 strcpy(gate_buf, pri->gate_addr);
 168
 169                 err = slip_tramp(argv, sfd);
 170
 171                 if (err < 0) {
 172                         printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
 173                                -err);
 174                         goto out_close2;
 175                 }
 176                 err = os_get_ifname(pri->slave, pri->name);
 177                 if (err < 0) {
 178                         printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
 179                                -err);
 180                         goto out_close2;
 181                 }
 182                 iter_addresses(pri->dev, open_addr, pri->name);
 183         }
 184         else {
 185                 err = os_set_slip(sfd);
 186                 if (err < 0) {
 187                         printk(UM_KERN_ERR "Failed to set slip discipline "
 188                                "encapsulation - err = %d\n", -err);
 189                         goto out_close2;
 190                 }
 191         }
 192         return mfd;
 193 out_close2:
 194         close(sfd);
 195 out_close:
 196         close(mfd);
 197 out:
 198         return err;
 199 }
 200
 201 static void slip_close(int fd, void *data)
 202 {
 203         struct slip_data *pri = data;
 204         char version_buf[sizeof("nnnnn\0")];
 205         char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
 206                          NULL };
 207         int err;
 208
 209         if (pri->gate_addr != NULL)
 210                 iter_addresses(pri->dev, close_addr, pri->name);
 211
 212         sprintf(version_buf, "%d", UML_NET_VERSION);
 213
 214         err = slip_tramp(argv, pri->slave);
 215
 216         if (err != 0)
 217                 printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
 218         close(fd);
 219         close(pri->slave);
 220         pri->slave = -1;
 221 }
 222
 223 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
 224 {
 225         return slip_proto_read(fd, buf, len, &pri->slip);
 226 }
 227
 228 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
 229 {
 230         return slip_proto_write(fd, buf, len, &pri->slip);
 231 }
 232
 233 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
 234                           void *data)
 235 {
 236         struct slip_data *pri = data;
 237
 238         if (pri->slave < 0)
 239                 return;
 240         open_addr(addr, netmask, pri->name);
 241 }
 242
 243 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
 244                             void *data)
 245 {
 246         struct slip_data *pri = data;
 247
 248         if (pri->slave < 0)
 249                 return;
 250         close_addr(addr, netmask, pri->name);
 251 }
 252
 253 const struct net_user_info slip_user_info = {
 254         .init           = slip_user_init,
 255         .open           = slip_open,
 256         .close          = slip_close,
 257         .remove         = NULL,
 258         .add_address    = slip_add_addr,
 259         .delete_address = slip_del_addr,
 260         .mtu            = BUF_SIZE,
 261         .max_packet     = BUF_SIZE,
 262 };