1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * DECnet An implementation of the DECnet protocol suite for the LINUX
4 * operating system. DECnet is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * DECnet sysctl support functions
8 *
9 * Author: Steve Whitehouse <SteveW@ACM.org>
10 *
11 *
12 * Changes:
13 * Steve Whitehouse - C99 changes and default device handling
14 * Steve Whitehouse - Memory buffer settings, like the tcp ones
15 *
16 */
17 #include <linux/mm.h>
18 #include <linux/sysctl.h>
19 #include <linux/fs.h>
20 #include <linux/netdevice.h>
21 #include <linux/string.h>
22 #include <net/neighbour.h>
23 #include <net/dst.h>
24 #include <net/flow.h>
25
26 #include <linux/uaccess.h>
27
28 #include <net/dn.h>
29 #include <net/dn_dev.h>
30 #include <net/dn_route.h>
31
32
33 int decnet_debug_level;
34 int decnet_time_wait = 30;
35 int decnet_dn_count = 1;
36 int decnet_di_count = 3;
37 int decnet_dr_count = 3;
38 int decnet_log_martians = 1;
39 int decnet_no_fc_max_cwnd = NSP_MIN_WINDOW;
40
41 /* Reasonable defaults, I hope, based on tcp's defaults */
42 long sysctl_decnet_mem[3] = { 768 << 3, 1024 << 3, 1536 << 3 };
43 int sysctl_decnet_wmem[3] = { 4 * 1024, 16 * 1024, 128 * 1024 };
44 int sysctl_decnet_rmem[3] = { 4 * 1024, 87380, 87380 * 2 };
45
46 #ifdef CONFIG_SYSCTL
47 extern int decnet_dst_gc_interval;
48 static int min_decnet_time_wait[] = { 5 };
49 static int max_decnet_time_wait[] = { 600 };
50 static int min_state_count[] = { 1 };
51 static int max_state_count[] = { NSP_MAXRXTSHIFT };
52 static int min_decnet_dst_gc_interval[] = { 1 };
53 static int max_decnet_dst_gc_interval[] = { 60 };
54 static int min_decnet_no_fc_max_cwnd[] = { NSP_MIN_WINDOW };
55 static int max_decnet_no_fc_max_cwnd[] = { NSP_MAX_WINDOW };
56 static char node_name[7] = "???";
57
58 static struct ctl_table_header *dn_table_header = NULL;
59
60 /*
61 * ctype.h :-)
62 */
63 #define ISNUM(x) (((x) >= '0') && ((x) <= '9'))
64 #define ISLOWER(x) (((x) >= 'a') && ((x) <= 'z'))
65 #define ISUPPER(x) (((x) >= 'A') && ((x) <= 'Z'))
66 #define ISALPHA(x) (ISLOWER(x) || ISUPPER(x))
67 #define INVALID_END_CHAR(x) (ISNUM(x) || ISALPHA(x))
68
strip_it(char * str)69 static void strip_it(char *str)
70 {
71 for(;;) {
72 switch (*str) {
73 case ' ':
74 case '\n':
75 case '\r':
76 case ':':
77 *str = 0;
78 /* Fallthrough */
79 case 0:
80 return;
81 }
82 str++;
83 }
84 }
85
86 /*
87 * Simple routine to parse an ascii DECnet address
88 * into a network order address.
89 */
parse_addr(__le16 * addr,char * str)90 static int parse_addr(__le16 *addr, char *str)
91 {
92 __u16 area, node;
93
94 while(*str && !ISNUM(*str)) str++;
95
96 if (*str == 0)
97 return -1;
98
99 area = (*str++ - '0');
100 if (ISNUM(*str)) {
101 area *= 10;
102 area += (*str++ - '0');
103 }
104
105 if (*str++ != '.')
106 return -1;
107
108 if (!ISNUM(*str))
109 return -1;
110
111 node = *str++ - '0';
112 if (ISNUM(*str)) {
113 node *= 10;
114 node += (*str++ - '0');
115 }
116 if (ISNUM(*str)) {
117 node *= 10;
118 node += (*str++ - '0');
119 }
120 if (ISNUM(*str)) {
121 node *= 10;
122 node += (*str++ - '0');
123 }
124
125 if ((node > 1023) || (area > 63))
126 return -1;
127
128 if (INVALID_END_CHAR(*str))
129 return -1;
130
131 *addr = cpu_to_le16((area << 10) | node);
132
133 return 0;
134 }
135
dn_node_address_handler(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)136 static int dn_node_address_handler(struct ctl_table *table, int write,
137 void __user *buffer,
138 size_t *lenp, loff_t *ppos)
139 {
140 char addr[DN_ASCBUF_LEN];
141 size_t len;
142 __le16 dnaddr;
143
144 if (!*lenp || (*ppos && !write)) {
145 *lenp = 0;
146 return 0;
147 }
148
149 if (write) {
150 len = (*lenp < DN_ASCBUF_LEN) ? *lenp : (DN_ASCBUF_LEN-1);
151
152 if (copy_from_user(addr, buffer, len))
153 return -EFAULT;
154
155 addr[len] = 0;
156 strip_it(addr);
157
158 if (parse_addr(&dnaddr, addr))
159 return -EINVAL;
160
161 dn_dev_devices_off();
162
163 decnet_address = dnaddr;
164
165 dn_dev_devices_on();
166
167 *ppos += len;
168
169 return 0;
170 }
171
172 dn_addr2asc(le16_to_cpu(decnet_address), addr);
173 len = strlen(addr);
174 addr[len++] = '\n';
175
176 if (len > *lenp) len = *lenp;
177
178 if (copy_to_user(buffer, addr, len))
179 return -EFAULT;
180
181 *lenp = len;
182 *ppos += len;
183
184 return 0;
185 }
186
dn_def_dev_handler(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)187 static int dn_def_dev_handler(struct ctl_table *table, int write,
188 void __user *buffer,
189 size_t *lenp, loff_t *ppos)
190 {
191 size_t len;
192 struct net_device *dev;
193 char devname[17];
194
195 if (!*lenp || (*ppos && !write)) {
196 *lenp = 0;
197 return 0;
198 }
199
200 if (write) {
201 if (*lenp > 16)
202 return -E2BIG;
203
204 if (copy_from_user(devname, buffer, *lenp))
205 return -EFAULT;
206
207 devname[*lenp] = 0;
208 strip_it(devname);
209
210 dev = dev_get_by_name(&init_net, devname);
211 if (dev == NULL)
212 return -ENODEV;
213
214 if (dev->dn_ptr == NULL) {
215 dev_put(dev);
216 return -ENODEV;
217 }
218
219 if (dn_dev_set_default(dev, 1)) {
220 dev_put(dev);
221 return -ENODEV;
222 }
223 *ppos += *lenp;
224
225 return 0;
226 }
227
228 dev = dn_dev_get_default();
229 if (dev == NULL) {
230 *lenp = 0;
231 return 0;
232 }
233
234 strcpy(devname, dev->name);
235 dev_put(dev);
236 len = strlen(devname);
237 devname[len++] = '\n';
238
239 if (len > *lenp) len = *lenp;
240
241 if (copy_to_user(buffer, devname, len))
242 return -EFAULT;
243
244 *lenp = len;
245 *ppos += len;
246
247 return 0;
248 }
249
250 static struct ctl_table dn_table[] = {
251 {
252 .procname = "node_address",
253 .maxlen = 7,
254 .mode = 0644,
255 .proc_handler = dn_node_address_handler,
256 },
257 {
258 .procname = "node_name",
259 .data = node_name,
260 .maxlen = 7,
261 .mode = 0644,
262 .proc_handler = proc_dostring,
263 },
264 {
265 .procname = "default_device",
266 .maxlen = 16,
267 .mode = 0644,
268 .proc_handler = dn_def_dev_handler,
269 },
270 {
271 .procname = "time_wait",
272 .data = &decnet_time_wait,
273 .maxlen = sizeof(int),
274 .mode = 0644,
275 .proc_handler = proc_dointvec_minmax,
276 .extra1 = &min_decnet_time_wait,
277 .extra2 = &max_decnet_time_wait
278 },
279 {
280 .procname = "dn_count",
281 .data = &decnet_dn_count,
282 .maxlen = sizeof(int),
283 .mode = 0644,
284 .proc_handler = proc_dointvec_minmax,
285 .extra1 = &min_state_count,
286 .extra2 = &max_state_count
287 },
288 {
289 .procname = "di_count",
290 .data = &decnet_di_count,
291 .maxlen = sizeof(int),
292 .mode = 0644,
293 .proc_handler = proc_dointvec_minmax,
294 .extra1 = &min_state_count,
295 .extra2 = &max_state_count
296 },
297 {
298 .procname = "dr_count",
299 .data = &decnet_dr_count,
300 .maxlen = sizeof(int),
301 .mode = 0644,
302 .proc_handler = proc_dointvec_minmax,
303 .extra1 = &min_state_count,
304 .extra2 = &max_state_count
305 },
306 {
307 .procname = "dst_gc_interval",
308 .data = &decnet_dst_gc_interval,
309 .maxlen = sizeof(int),
310 .mode = 0644,
311 .proc_handler = proc_dointvec_minmax,
312 .extra1 = &min_decnet_dst_gc_interval,
313 .extra2 = &max_decnet_dst_gc_interval
314 },
315 {
316 .procname = "no_fc_max_cwnd",
317 .data = &decnet_no_fc_max_cwnd,
318 .maxlen = sizeof(int),
319 .mode = 0644,
320 .proc_handler = proc_dointvec_minmax,
321 .extra1 = &min_decnet_no_fc_max_cwnd,
322 .extra2 = &max_decnet_no_fc_max_cwnd
323 },
324 {
325 .procname = "decnet_mem",
326 .data = &sysctl_decnet_mem,
327 .maxlen = sizeof(sysctl_decnet_mem),
328 .mode = 0644,
329 .proc_handler = proc_doulongvec_minmax
330 },
331 {
332 .procname = "decnet_rmem",
333 .data = &sysctl_decnet_rmem,
334 .maxlen = sizeof(sysctl_decnet_rmem),
335 .mode = 0644,
336 .proc_handler = proc_dointvec,
337 },
338 {
339 .procname = "decnet_wmem",
340 .data = &sysctl_decnet_wmem,
341 .maxlen = sizeof(sysctl_decnet_wmem),
342 .mode = 0644,
343 .proc_handler = proc_dointvec,
344 },
345 {
346 .procname = "debug",
347 .data = &decnet_debug_level,
348 .maxlen = sizeof(int),
349 .mode = 0644,
350 .proc_handler = proc_dointvec,
351 },
352 { }
353 };
354
dn_register_sysctl(void)355 void dn_register_sysctl(void)
356 {
357 dn_table_header = register_net_sysctl(&init_net, "net/decnet", dn_table);
358 }
359
dn_unregister_sysctl(void)360 void dn_unregister_sysctl(void)
361 {
362 unregister_net_sysctl_table(dn_table_header);
363 }
364
365 #else /* CONFIG_SYSCTL */
dn_unregister_sysctl(void)366 void dn_unregister_sysctl(void)
367 {
368 }
dn_register_sysctl(void)369 void dn_register_sysctl(void)
370 {
371 }
372
373 #endif
374