1/*
2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <stdio.h>
7#include <unistd.h>
8#include <errno.h>
9#include <os.h>
10
11struct dog_data {
12	int stdin_fd;
13	int stdout_fd;
14	int close_me[2];
15};
16
17static void pre_exec(void *d)
18{
19	struct dog_data *data = d;
20
21	dup2(data->stdin_fd, 0);
22	dup2(data->stdout_fd, 1);
23	dup2(data->stdout_fd, 2);
24	close(data->stdin_fd);
25	close(data->stdout_fd);
26	close(data->close_me[0]);
27	close(data->close_me[1]);
28}
29
30int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
31{
32	struct dog_data data;
33	int in_fds[2], out_fds[2], pid, n, err;
34	char pid_buf[sizeof("nnnnnnn\0")], c;
35	char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
36	char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
37				  NULL };
38	char **args = NULL;
39
40	err = os_pipe(in_fds, 1, 0);
41	if (err < 0) {
42		printk("harddog_open - os_pipe failed, err = %d\n", -err);
43		goto out;
44	}
45
46	err = os_pipe(out_fds, 1, 0);
47	if (err < 0) {
48		printk("harddog_open - os_pipe failed, err = %d\n", -err);
49		goto out_close_in;
50	}
51
52	data.stdin_fd = out_fds[0];
53	data.stdout_fd = in_fds[1];
54	data.close_me[0] = out_fds[1];
55	data.close_me[1] = in_fds[0];
56
57	if (sock != NULL) {
58		mconsole_args[2] = sock;
59		args = mconsole_args;
60	}
61	else {
62		/* XXX The os_getpid() is not SMP correct */
63		sprintf(pid_buf, "%d", os_getpid());
64		args = pid_args;
65	}
66
67	pid = run_helper(pre_exec, &data, args);
68
69	close(out_fds[0]);
70	close(in_fds[1]);
71
72	if (pid < 0) {
73		err = -pid;
74		printk("harddog_open - run_helper failed, errno = %d\n", -err);
75		goto out_close_out;
76	}
77
78	n = read(in_fds[0], &c, sizeof(c));
79	if (n == 0) {
80		printk("harddog_open - EOF on watchdog pipe\n");
81		helper_wait(pid);
82		err = -EIO;
83		goto out_close_out;
84	}
85	else if (n < 0) {
86		printk("harddog_open - read of watchdog pipe failed, "
87		       "err = %d\n", errno);
88		helper_wait(pid);
89		err = n;
90		goto out_close_out;
91	}
92	*in_fd_ret = in_fds[0];
93	*out_fd_ret = out_fds[1];
94	return 0;
95
96 out_close_in:
97	close(in_fds[0]);
98	close(in_fds[1]);
99 out_close_out:
100	close(out_fds[0]);
101	close(out_fds[1]);
102 out:
103	return err;
104}
105
106void stop_watchdog(int in_fd, int out_fd)
107{
108	close(in_fd);
109	close(out_fd);
110}
111
112int ping_watchdog(int fd)
113{
114	int n;
115	char c = '\n';
116
117	n = write(fd, &c, sizeof(c));
118	if (n != sizeof(c)) {
119		printk("ping_watchdog - write failed, ret = %d, err = %d\n",
120		       n, errno);
121		if (n < 0)
122			return n;
123		return -EIO;
124	}
125	return 1;
126
127}
128