arch/um/drivers/chan_user.c

   1 /*
   2  * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <unistd.h>
   7 #include <stdlib.h>
   8 #include <errno.h>
   9 #include <termios.h>
  10 #include <string.h>
  11 #include <signal.h>
  12 #include <sys/stat.h>
  13 #include <sys/ioctl.h>
  14 #include <sys/socket.h>
  15 #include "kern_util.h"
  16 #include "user_util.h"
  17 #include "chan_user.h"
  18 #include "user.h"
  19 #include "helper.h"
  20 #include "os.h"
  21 #include "choose-mode.h"
  22 #include "mode.h"
  23
  24 int generic_console_write(int fd, const char *buf, int n, void *unused)
  25 {
  26         struct termios save, new;
  27         int err;
  28
  29         if(isatty(fd)){
  30                 tcgetattr(fd, &save);
  31                 new = save;
  32                 new.c_oflag |= OPOST;
  33                 tcsetattr(fd, TCSAFLUSH, &new);
  34         }
  35         err = generic_write(fd, buf, n, NULL);
  36         if(isatty(fd)) tcsetattr(fd, TCSAFLUSH, &save);
  37         return(err);
  38 }
  39
  40 static void winch_handler(int sig)
  41 {
  42 }
  43
  44 struct winch_data {
  45         int pty_fd;
  46         int pipe_fd;
  47         int close_me;
  48 };
  49
  50 static int winch_thread(void *arg)
  51 {
  52         struct winch_data *data = arg;
  53         sigset_t sigs;
  54         int pty_fd, pipe_fd;
  55         int count, err;
  56         char c = 1;
  57
  58         os_close_file(data->close_me);
  59         pty_fd = data->pty_fd;
  60         pipe_fd = data->pipe_fd;
  61         count = os_write_file(pipe_fd, &c, sizeof(c));
  62         if(count != sizeof(c))
  63                 printk("winch_thread : failed to write synchronization "
  64                        "byte, err = %d\n", -count);
  65
  66         signal(SIGWINCH, winch_handler);
  67         sigfillset(&sigs);
  68         sigdelset(&sigs, SIGWINCH);
  69         if(sigprocmask(SIG_SETMASK, &sigs, NULL) < 0){
  70                 printk("winch_thread : sigprocmask failed, errno = %d\n",
  71                        errno);
  72                 exit(1);
  73         }
  74
  75         if(setsid() < 0){
  76                 printk("winch_thread : setsid failed, errno = %d\n", errno);
  77                 exit(1);
  78         }
  79
  80         err = os_new_tty_pgrp(pty_fd, os_getpid());
  81         if(err < 0){
  82                 printk("winch_thread : new_tty_pgrp failed, err = %d\n", -err);
  83                 exit(1);
  84         }
  85
  86         count = os_read_file(pipe_fd, &c, sizeof(c));
  87         if(count != sizeof(c))
  88                 printk("winch_thread : failed to read synchronization byte, "
  89                        "err = %d\n", -count);
  90
  91         while(1){
  92                 pause();
  93
  94                 count = os_write_file(pipe_fd, &c, sizeof(c));
  95                 if(count != sizeof(c))
  96                         printk("winch_thread : write failed, err = %d\n",
  97                                -count);
  98         }
  99 }
 100
 101 static int winch_tramp(int fd, void *device_data, int *fd_out)
 102 {
 103         struct winch_data data;
 104         unsigned long stack;
 105         int fds[2], pid, n, err;
 106         char c;
 107
 108         err = os_pipe(fds, 1, 1);
 109         if(err < 0){
 110                 printk("winch_tramp : os_pipe failed, err = %d\n", -err);
 111                 return(err);
 112         }
 113
 114         data = ((struct winch_data) { .pty_fd           = fd,
 115                                       .pipe_fd          = fds[1],
 116                                       .close_me         = fds[0] } );
 117         pid = run_helper_thread(winch_thread, &data, 0, &stack, 0);
 118         if(pid < 0){
 119                 printk("fork of winch_thread failed - errno = %d\n", errno);
 120                 return(pid);
 121         }
 122
 123         os_close_file(fds[1]);
 124         *fd_out = fds[0];
 125         n = os_read_file(fds[0], &c, sizeof(c));
 126         if(n != sizeof(c)){
 127                 printk("winch_tramp : failed to read synchronization byte\n");
 128                 printk("read failed, err = %d\n", -n);
 129                 printk("fd %d will not support SIGWINCH\n", fd);
 130                 *fd_out = -1;
 131         }
 132         return(pid);
 133 }
 134
 135 void register_winch(int fd, void *device_data)
 136 {
 137         int pid, thread, thread_fd;
 138         int count;
 139         char c = 1;
 140
 141         if(!isatty(fd))
 142                 return;
 143
 144         pid = tcgetpgrp(fd);
 145         if(!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd,
 146                              device_data) && (pid == -1)){
 147                 thread = winch_tramp(fd, device_data, &thread_fd);
 148                 if(fd != -1){
 149                         register_winch_irq(thread_fd, fd, thread, device_data);
 150
 151                         count = os_write_file(thread_fd, &c, sizeof(c));
 152                         if(count != sizeof(c))
 153                                 printk("register_winch : failed to write "
 154                                        "synchronization byte, err = %d\n",
 155                                         -count);
 156                 }
 157         }
 158 }
 159
 160 /*
 161  * Overrides for Emacs so that we follow Linus's tabbing style.
 162  * Emacs will notice this stuff at the end of the file and automatically
 163  * adjust the settings for this buffer only.  This must remain at the end
 164  * of the file.
 165  * ---------------------------------------------------------------------------
 166  * Local variables:
 167  * c-file-style: "linux"
 168  * End:
 169  */