1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/net/sunrpc/sysctl.c
4 *
5 * Sysctl interface to sunrpc module.
6 *
7 * I would prefer to register the sunrpc table below sys/net, but that's
8 * impossible at the moment.
9 */
10
11#include <linux/types.h>
12#include <linux/linkage.h>
13#include <linux/ctype.h>
14#include <linux/fs.h>
15#include <linux/sysctl.h>
16#include <linux/module.h>
17
18#include <linux/uaccess.h>
19#include <linux/sunrpc/types.h>
20#include <linux/sunrpc/sched.h>
21#include <linux/sunrpc/stats.h>
22#include <linux/sunrpc/svc_xprt.h>
23
24#include "netns.h"
25
26/*
27 * Declare the debug flags here
28 */
29unsigned int rpc_debug;
30EXPORT_SYMBOL_GPL(rpc_debug);
31
32unsigned int nfs_debug;
33EXPORT_SYMBOL_GPL(nfs_debug);
34
35unsigned int nfsd_debug;
36EXPORT_SYMBOL_GPL(nfsd_debug);
37
38unsigned int nlm_debug;
39EXPORT_SYMBOL_GPL(nlm_debug);
40
41#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
42
43static int proc_do_xprt(const struct ctl_table *table, int write,
44 void *buffer, size_t *lenp, loff_t *ppos)
45{
46 char tmpbuf[256];
47 ssize_t len;
48
49 if (write || *ppos) {
50 *lenp = 0;
51 return 0;
52 }
53 len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
54 len = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
55
56 if (len < 0) {
57 *lenp = 0;
58 return -EINVAL;
59 }
60 *lenp = len;
61 return 0;
62}
63
64static int
65proc_dodebug(const struct ctl_table *table, int write, void *buffer, size_t *lenp,
66 loff_t *ppos)
67{
68 char tmpbuf[20], *s = NULL;
69 char *p;
70 unsigned int value;
71 size_t left, len;
72
73 if ((*ppos && !write) || !*lenp) {
74 *lenp = 0;
75 return 0;
76 }
77
78 left = *lenp;
79
80 if (write) {
81 p = buffer;
82 while (left && isspace(*p)) {
83 left--;
84 p++;
85 }
86 if (!left)
87 goto done;
88
89 if (left > sizeof(tmpbuf) - 1)
90 return -EINVAL;
91 memcpy(tmpbuf, p, left);
92 tmpbuf[left] = '\0';
93
94 value = simple_strtol(tmpbuf, &s, 0);
95 if (s) {
96 left -= (s - tmpbuf);
97 if (left && !isspace(*s))
98 return -EINVAL;
99 while (left && isspace(*s)) {
100 left--;
101 s++;
102 }
103 } else
104 left = 0;
105 *(unsigned int *) table->data = value;
106 /* Display the RPC tasks on writing to rpc_debug */
107 if (strcmp(table->procname, "rpc_debug") == 0)
108 rpc_show_tasks(&init_net);
109 } else {
110 len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
111 if (len > left)
112 len = left;
113 memcpy(buffer, tmpbuf, len);
114 if ((left -= len) > 0) {
115 *((char *)buffer + len) = '\n';
116 left--;
117 }
118 }
119
120done:
121 *lenp -= left;
122 *ppos += *lenp;
123 return 0;
124}
125
126static struct ctl_table_header *sunrpc_table_header;
127
128static struct ctl_table debug_table[] = {
129 {
130 .procname = "rpc_debug",
131 .data = &rpc_debug,
132 .maxlen = sizeof(int),
133 .mode = 0644,
134 .proc_handler = proc_dodebug
135 },
136 {
137 .procname = "nfs_debug",
138 .data = &nfs_debug,
139 .maxlen = sizeof(int),
140 .mode = 0644,
141 .proc_handler = proc_dodebug
142 },
143 {
144 .procname = "nfsd_debug",
145 .data = &nfsd_debug,
146 .maxlen = sizeof(int),
147 .mode = 0644,
148 .proc_handler = proc_dodebug
149 },
150 {
151 .procname = "nlm_debug",
152 .data = &nlm_debug,
153 .maxlen = sizeof(int),
154 .mode = 0644,
155 .proc_handler = proc_dodebug
156 },
157 {
158 .procname = "transports",
159 .maxlen = 256,
160 .mode = 0444,
161 .proc_handler = proc_do_xprt,
162 },
163};
164
165void
166rpc_register_sysctl(void)
167{
168 if (!sunrpc_table_header)
169 sunrpc_table_header = register_sysctl("sunrpc", debug_table);
170}
171
172void
173rpc_unregister_sysctl(void)
174{
175 if (sunrpc_table_header) {
176 unregister_sysctl_table(sunrpc_table_header);
177 sunrpc_table_header = NULL;
178 }
179}
180#endif
181