1/*
2 * linux/net/sunrpc/sysctl.c
3 *
4 * Sysctl interface to sunrpc module.
5 *
6 * I would prefer to register the sunrpc table below sys/net, but that's
7 * impossible at the moment.
8 */
9
10#include <linux/types.h>
11#include <linux/linkage.h>
12#include <linux/ctype.h>
13#include <linux/fs.h>
14#include <linux/sysctl.h>
15#include <linux/module.h>
16
17#include <asm/uaccess.h>
18#include <linux/sunrpc/types.h>
19#include <linux/sunrpc/sched.h>
20#include <linux/sunrpc/stats.h>
21#include <linux/sunrpc/svc_xprt.h>
22
23#include "netns.h"
24
25/*
26 * Declare the debug flags here
27 */
28unsigned int	rpc_debug;
29EXPORT_SYMBOL_GPL(rpc_debug);
30
31unsigned int	nfs_debug;
32EXPORT_SYMBOL_GPL(nfs_debug);
33
34unsigned int	nfsd_debug;
35EXPORT_SYMBOL_GPL(nfsd_debug);
36
37unsigned int	nlm_debug;
38EXPORT_SYMBOL_GPL(nlm_debug);
39
40#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
41
42static struct ctl_table_header *sunrpc_table_header;
43static struct ctl_table sunrpc_table[];
44
45void
46rpc_register_sysctl(void)
47{
48	if (!sunrpc_table_header)
49		sunrpc_table_header = register_sysctl_table(sunrpc_table);
50}
51
52void
53rpc_unregister_sysctl(void)
54{
55	if (sunrpc_table_header) {
56		unregister_sysctl_table(sunrpc_table_header);
57		sunrpc_table_header = NULL;
58	}
59}
60
61static int proc_do_xprt(struct ctl_table *table, int write,
62			void __user *buffer, size_t *lenp, loff_t *ppos)
63{
64	char tmpbuf[256];
65	size_t len;
66
67	if ((*ppos && !write) || !*lenp) {
68		*lenp = 0;
69		return 0;
70	}
71	len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
72	return simple_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
73}
74
75static int
76proc_dodebug(struct ctl_table *table, int write,
77				void __user *buffer, size_t *lenp, loff_t *ppos)
78{
79	char		tmpbuf[20], c, *s;
80	char __user *p;
81	unsigned int	value;
82	size_t		left, len;
83
84	if ((*ppos && !write) || !*lenp) {
85		*lenp = 0;
86		return 0;
87	}
88
89	left = *lenp;
90
91	if (write) {
92		if (!access_ok(VERIFY_READ, buffer, left))
93			return -EFAULT;
94		p = buffer;
95		while (left && __get_user(c, p) >= 0 && isspace(c))
96			left--, p++;
97		if (!left)
98			goto done;
99
100		if (left > sizeof(tmpbuf) - 1)
101			return -EINVAL;
102		if (copy_from_user(tmpbuf, p, left))
103			return -EFAULT;
104		tmpbuf[left] = '\0';
105
106		for (s = tmpbuf, value = 0; '0' <= *s && *s <= '9'; s++, left--)
107			value = 10 * value + (*s - '0');
108		if (*s && !isspace(*s))
109			return -EINVAL;
110		while (left && isspace(*s))
111			left--, s++;
112		*(unsigned int *) table->data = value;
113		/* Display the RPC tasks on writing to rpc_debug */
114		if (strcmp(table->procname, "rpc_debug") == 0)
115			rpc_show_tasks(&init_net);
116	} else {
117		if (!access_ok(VERIFY_WRITE, buffer, left))
118			return -EFAULT;
119		len = sprintf(tmpbuf, "%d", *(unsigned int *) table->data);
120		if (len > left)
121			len = left;
122		if (__copy_to_user(buffer, tmpbuf, len))
123			return -EFAULT;
124		if ((left -= len) > 0) {
125			if (put_user('\n', (char __user *)buffer + len))
126				return -EFAULT;
127			left--;
128		}
129	}
130
131done:
132	*lenp -= left;
133	*ppos += *lenp;
134	return 0;
135}
136
137
138static struct ctl_table debug_table[] = {
139	{
140		.procname	= "rpc_debug",
141		.data		= &rpc_debug,
142		.maxlen		= sizeof(int),
143		.mode		= 0644,
144		.proc_handler	= proc_dodebug
145	},
146	{
147		.procname	= "nfs_debug",
148		.data		= &nfs_debug,
149		.maxlen		= sizeof(int),
150		.mode		= 0644,
151		.proc_handler	= proc_dodebug
152	},
153	{
154		.procname	= "nfsd_debug",
155		.data		= &nfsd_debug,
156		.maxlen		= sizeof(int),
157		.mode		= 0644,
158		.proc_handler	= proc_dodebug
159	},
160	{
161		.procname	= "nlm_debug",
162		.data		= &nlm_debug,
163		.maxlen		= sizeof(int),
164		.mode		= 0644,
165		.proc_handler	= proc_dodebug
166	},
167	{
168		.procname	= "transports",
169		.maxlen		= 256,
170		.mode		= 0444,
171		.proc_handler	= proc_do_xprt,
172	},
173	{ }
174};
175
176static struct ctl_table sunrpc_table[] = {
177	{
178		.procname	= "sunrpc",
179		.mode		= 0555,
180		.child		= debug_table
181	},
182	{ }
183};
184
185#endif
186