arch/um/drivers/xterm.c

   1 /*
   2  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stddef.h>
   7 #include <stdlib.h>
   8 #include <stdio.h>
   9 #include <unistd.h>
  10 #include <errno.h>
  11 #include <string.h>
  12 #include <termios.h>
  13 #include "chan_user.h"
  14 #include "kern_constants.h"
  15 #include "os.h"
  16 #include "um_malloc.h"
  17 #include "user.h"
  18 #include "xterm.h"
  19
  20 struct xterm_chan {
  21         int pid;
  22         int helper_pid;
  23         char *title;
  24         int device;
  25         int raw;
  26         struct termios tt;
  27 };
  28
  29 static void *xterm_init(char *str, int device, const struct chan_opts *opts)
  30 {
  31         struct xterm_chan *data;
  32
  33         data = kmalloc(sizeof(*data), UM_GFP_KERNEL);
  34         if (data == NULL)
  35                 return NULL;
  36         *data = ((struct xterm_chan) { .pid             = -1,
  37                                        .helper_pid      = -1,
  38                                        .device          = device,
  39                                        .title           = opts->xterm_title,
  40                                        .raw             = opts->raw } );
  41         return data;
  42 }
  43
  44 /* Only changed by xterm_setup, which is a setup */
  45 static char *terminal_emulator = "xterm";
  46 static char *title_switch = "-T";
  47 static char *exec_switch = "-e";
  48
  49 static int __init xterm_setup(char *line, int *add)
  50 {
  51         *add = 0;
  52         terminal_emulator = line;
  53
  54         line = strchr(line, ',');
  55         if (line == NULL)
  56                 return 0;
  57
  58         *line++ = '\0';
  59         if (*line)
  60                 title_switch = line;
  61
  62         line = strchr(line, ',');
  63         if (line == NULL)
  64                 return 0;
  65
  66         *line++ = '\0';
  67         if (*line)
  68                 exec_switch = line;
  69
  70         return 0;
  71 }
  72
  73 __uml_setup("xterm=", xterm_setup,
  74 "xterm=<terminal emulator>,<title switch>,<exec switch>\n"
  75 "    Specifies an alternate terminal emulator to use for the debugger,\n"
  76 "    consoles, and serial lines when they are attached to the xterm channel.\n"
  77 "    The values are the terminal emulator binary, the switch it uses to set\n"
  78 "    its title, and the switch it uses to execute a subprocess,\n"
  79 "    respectively.  The title switch must have the form '<switch> title',\n"
  80 "    not '<switch>=title'.  Similarly, the exec switch must have the form\n"
  81 "    '<switch> command arg1 arg2 ...'.\n"
  82 "    The default values are 'xterm=xterm,-T,-e'.  Values for gnome-terminal\n"
  83 "    are 'xterm=gnome-terminal,-t,-x'.\n\n"
  84 );
  85
  86 static int xterm_open(int input, int output, int primary, void *d,
  87                       char **dev_out)
  88 {
  89         struct xterm_chan *data = d;
  90         int pid, fd, new, err;
  91         char title[256], file[] = "/tmp/xterm-pipeXXXXXX";
  92         char *argv[] = { terminal_emulator, title_switch, title, exec_switch,
  93                          "/usr/lib/uml/port-helper", "-uml-socket",
  94                          file, NULL };
  95
  96         if (access(argv[4], X_OK) < 0)
  97                 argv[4] = "port-helper";
  98
  99         /* Check that DISPLAY is set, this doesn't guarantee the xterm
 100          * will work but w/o it we can be pretty sure it won't. */
 101         if (getenv("DISPLAY") == NULL) {
 102                 printk(UM_KERN_ERR "xterm_open: $DISPLAY not set.\n");
 103                 return -ENODEV;
 104         }
 105
 106         /*
 107          * This business of getting a descriptor to a temp file,
 108          * deleting the file and closing the descriptor is just to get
 109          * a known-unused name for the Unix socket that we really
 110          * want.
 111          */
 112         fd = mkstemp(file);
 113         if (fd < 0) {
 114                 err = -errno;
 115                 printk(UM_KERN_ERR "xterm_open : mkstemp failed, errno = %d\n",
 116                        errno);
 117                 return err;
 118         }
 119
 120         if (unlink(file)) {
 121                 err = -errno;
 122                 printk(UM_KERN_ERR "xterm_open : unlink failed, errno = %d\n",
 123                        errno);
 124                 return err;
 125         }
 126         close(fd);
 127
 128         fd = os_create_unix_socket(file, sizeof(file), 1);
 129         if (fd < 0) {
 130                 printk(UM_KERN_ERR "xterm_open : create_unix_socket failed, "
 131                        "errno = %d\n", -fd);
 132                 return fd;
 133         }
 134
 135         sprintf(title, data->title, data->device);
 136         pid = run_helper(NULL, NULL, argv);
 137         if (pid < 0) {
 138                 err = pid;
 139                 printk(UM_KERN_ERR "xterm_open : run_helper failed, "
 140                        "errno = %d\n", -err);
 141                 goto out_close1;
 142         }
 143
 144         err = os_set_fd_block(fd, 0);
 145         if (err < 0) {
 146                 printk(UM_KERN_ERR "xterm_open : failed to set descriptor "
 147                        "non-blocking, err = %d\n", -err);
 148                 goto out_kill;
 149         }
 150
 151         new = xterm_fd(fd, &data->helper_pid);
 152         if (new < 0) {
 153                 err = new;
 154                 printk(UM_KERN_ERR "xterm_open : os_rcv_fd failed, err = %d\n",
 155                        -err);
 156                 goto out_kill;
 157         }
 158
 159         err = os_set_fd_block(new, 0);
 160         if (err) {
 161                 printk(UM_KERN_ERR "xterm_open : failed to set xterm "
 162                        "descriptor non-blocking, err = %d\n", -err);
 163                 goto out_close2;
 164         }
 165
 166         CATCH_EINTR(err = tcgetattr(new, &data->tt));
 167         if (err) {
 168                 new = err;
 169                 goto out_close2;
 170         }
 171
 172         if (data->raw) {
 173                 err = raw(new);
 174                 if (err) {
 175                         new = err;
 176                         goto out_close2;
 177                 }
 178         }
 179
 180         unlink(file);
 181         data->pid = pid;
 182         *dev_out = NULL;
 183
 184         return new;
 185
 186  out_close2:
 187         close(new);
 188  out_kill:
 189         os_kill_process(pid, 1);
 190  out_close1:
 191         close(fd);
 192
 193         return err;
 194 }
 195
 196 static void xterm_close(int fd, void *d)
 197 {
 198         struct xterm_chan *data = d;
 199
 200         if (data->pid != -1)
 201                 os_kill_process(data->pid, 1);
 202         data->pid = -1;
 203
 204         if (data->helper_pid != -1)
 205                 os_kill_process(data->helper_pid, 0);
 206         data->helper_pid = -1;
 207
 208         os_close_file(fd);
 209 }
 210
 211 const struct chan_ops xterm_ops = {
 212         .type           = "xterm",
 213         .init           = xterm_init,
 214         .open           = xterm_open,
 215         .close          = xterm_close,
 216         .read           = generic_read,
 217         .write          = generic_write,
 218         .console_write  = generic_console_write,
 219         .window_size    = generic_window_size,
 220         .free           = generic_free,
 221         .winch          = 1,
 222 };