Pileus Git - ~andy/linux/blob - arch/um/drivers/harddog_user.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <unistd.h>
   8 #include <errno.h>
   9 #include "user.h"
  10 #include "mconsole.h"
  11 #include "os.h"
  12 #include "mode.h"
  13
  14 struct dog_data {
  15         int stdin;
  16         int stdout;
  17         int close_me[2];
  18 };
  19
  20 static void pre_exec(void *d)
  21 {
  22         struct dog_data *data = d;
  23
  24         dup2(data->stdin, 0);
  25         dup2(data->stdout, 1);
  26         dup2(data->stdout, 2);
  27         os_close_file(data->stdin);
  28         os_close_file(data->stdout);
  29         os_close_file(data->close_me[0]);
  30         os_close_file(data->close_me[1]);
  31 }
  32
  33 int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
  34 {
  35         struct dog_data data;
  36         int in_fds[2], out_fds[2], pid, n, err;
  37         char pid_buf[sizeof("nnnnn\0")], c;
  38         char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
  39         char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
  40                                   NULL };
  41         char **args = NULL;
  42
  43         err = os_pipe(in_fds, 1, 0);
  44         if(err < 0){
  45                 printk("harddog_open - os_pipe failed, err = %d\n", -err);
  46                 goto out;
  47         }
  48
  49         err = os_pipe(out_fds, 1, 0);
  50         if(err < 0){
  51                 printk("harddog_open - os_pipe failed, err = %d\n", -err);
  52                 goto out_close_in;
  53         }
  54
  55         data.stdin = out_fds[0];
  56         data.stdout = in_fds[1];
  57         data.close_me[0] = out_fds[1];
  58         data.close_me[1] = in_fds[0];
  59
  60         if(sock != NULL){
  61                 mconsole_args[2] = sock;
  62                 args = mconsole_args;
  63         }
  64         else {
  65                 /* XXX The os_getpid() is not SMP correct */
  66                 sprintf(pid_buf, "%d", os_getpid());
  67                 args = pid_args;
  68         }
  69
  70         pid = run_helper(pre_exec, &data, args);
  71
  72         os_close_file(out_fds[0]);
  73         os_close_file(in_fds[1]);
  74
  75         if(pid < 0){
  76                 err = -pid;
  77                 printk("harddog_open - run_helper failed, errno = %d\n", -err);
  78                 goto out_close_out;
  79         }
  80
  81         n = os_read_file(in_fds[0], &c, sizeof(c));
  82         if(n == 0){
  83                 printk("harddog_open - EOF on watchdog pipe\n");
  84                 helper_wait(pid);
  85                 err = -EIO;
  86                 goto out_close_out;
  87         }
  88         else if(n < 0){
  89                 printk("harddog_open - read of watchdog pipe failed, "
  90                        "err = %d\n", -n);
  91                 helper_wait(pid);
  92                 err = n;
  93                 goto out_close_out;
  94         }
  95         *in_fd_ret = in_fds[0];
  96         *out_fd_ret = out_fds[1];
  97         return 0;
  98
  99  out_close_in:
 100         os_close_file(in_fds[0]);
 101         os_close_file(in_fds[1]);
 102  out_close_out:
 103         os_close_file(out_fds[0]);
 104         os_close_file(out_fds[1]);
 105  out:
 106         return err;
 107 }
 108
 109 void stop_watchdog(int in_fd, int out_fd)
 110 {
 111         os_close_file(in_fd);
 112         os_close_file(out_fd);
 113 }
 114
 115 int ping_watchdog(int fd)
 116 {
 117         int n;
 118         char c = '\n';
 119
 120         n = os_write_file(fd, &c, sizeof(c));
 121         if(n != sizeof(c)){
 122                 printk("ping_watchdog - write failed, err = %d\n", -n);
 123                 if(n < 0)
 124                         return n;
 125                 return -EIO;
 126         }
 127         return 1;
 128
 129 }