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 * buffer,size_t * lenp,loff_t * ppos)136 static int dn_node_address_handler(struct ctl_table *table, int write,
137 void *buffer, size_t *lenp, loff_t *ppos)
138 {
139 char addr[DN_ASCBUF_LEN];
140 size_t len;
141 __le16 dnaddr;
142
143 if (!*lenp || (*ppos && !write)) {
144 *lenp = 0;
145 return 0;
146 }
147
148 if (write) {
149 len = (*lenp < DN_ASCBUF_LEN) ? *lenp : (DN_ASCBUF_LEN-1);
150 memcpy(addr, buffer, len);
151 addr[len] = 0;
152 strip_it(addr);
153
154 if (parse_addr(&dnaddr, addr))
155 return -EINVAL;
156
157 dn_dev_devices_off();
158
159 decnet_address = dnaddr;
160
161 dn_dev_devices_on();
162
163 *ppos += len;
164
165 return 0;
166 }
167
168 dn_addr2asc(le16_to_cpu(decnet_address), addr);
169 len = strlen(addr);
170 addr[len++] = '\n';
171
172 if (len > *lenp)
173 len = *lenp;
174 memcpy(buffer, addr, len);
175 *lenp = len;
176 *ppos += len;
177
178 return 0;
179 }
180
dn_def_dev_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)181 static int dn_def_dev_handler(struct ctl_table *table, int write,
182 void *buffer, size_t *lenp, loff_t *ppos)
183 {
184 size_t len;
185 struct net_device *dev;
186 char devname[17];
187
188 if (!*lenp || (*ppos && !write)) {
189 *lenp = 0;
190 return 0;
191 }
192
193 if (write) {
194 if (*lenp > 16)
195 return -E2BIG;
196
197 memcpy(devname, buffer, *lenp);
198 devname[*lenp] = 0;
199 strip_it(devname);
200
201 dev = dev_get_by_name(&init_net, devname);
202 if (dev == NULL)
203 return -ENODEV;
204
205 if (dev->dn_ptr == NULL) {
206 dev_put(dev);
207 return -ENODEV;
208 }
209
210 if (dn_dev_set_default(dev, 1)) {
211 dev_put(dev);
212 return -ENODEV;
213 }
214 *ppos += *lenp;
215
216 return 0;
217 }
218
219 dev = dn_dev_get_default();
220 if (dev == NULL) {
221 *lenp = 0;
222 return 0;
223 }
224
225 strcpy(devname, dev->name);
226 dev_put(dev);
227 len = strlen(devname);
228 devname[len++] = '\n';
229
230 if (len > *lenp) len = *lenp;
231
232 memcpy(buffer, devname, len);
233 *lenp = len;
234 *ppos += len;
235
236 return 0;
237 }
238
239 static struct ctl_table dn_table[] = {
240 {
241 .procname = "node_address",
242 .maxlen = 7,
243 .mode = 0644,
244 .proc_handler = dn_node_address_handler,
245 },
246 {
247 .procname = "node_name",
248 .data = node_name,
249 .maxlen = 7,
250 .mode = 0644,
251 .proc_handler = proc_dostring,
252 },
253 {
254 .procname = "default_device",
255 .maxlen = 16,
256 .mode = 0644,
257 .proc_handler = dn_def_dev_handler,
258 },
259 {
260 .procname = "time_wait",
261 .data = &decnet_time_wait,
262 .maxlen = sizeof(int),
263 .mode = 0644,
264 .proc_handler = proc_dointvec_minmax,
265 .extra1 = &min_decnet_time_wait,
266 .extra2 = &max_decnet_time_wait
267 },
268 {
269 .procname = "dn_count",
270 .data = &decnet_dn_count,
271 .maxlen = sizeof(int),
272 .mode = 0644,
273 .proc_handler = proc_dointvec_minmax,
274 .extra1 = &min_state_count,
275 .extra2 = &max_state_count
276 },
277 {
278 .procname = "di_count",
279 .data = &decnet_di_count,
280 .maxlen = sizeof(int),
281 .mode = 0644,
282 .proc_handler = proc_dointvec_minmax,
283 .extra1 = &min_state_count,
284 .extra2 = &max_state_count
285 },
286 {
287 .procname = "dr_count",
288 .data = &decnet_dr_count,
289 .maxlen = sizeof(int),
290 .mode = 0644,
291 .proc_handler = proc_dointvec_minmax,
292 .extra1 = &min_state_count,
293 .extra2 = &max_state_count
294 },
295 {
296 .procname = "dst_gc_interval",
297 .data = &decnet_dst_gc_interval,
298 .maxlen = sizeof(int),
299 .mode = 0644,
300 .proc_handler = proc_dointvec_minmax,
301 .extra1 = &min_decnet_dst_gc_interval,
302 .extra2 = &max_decnet_dst_gc_interval
303 },
304 {
305 .procname = "no_fc_max_cwnd",
306 .data = &decnet_no_fc_max_cwnd,
307 .maxlen = sizeof(int),
308 .mode = 0644,
309 .proc_handler = proc_dointvec_minmax,
310 .extra1 = &min_decnet_no_fc_max_cwnd,
311 .extra2 = &max_decnet_no_fc_max_cwnd
312 },
313 {
314 .procname = "decnet_mem",
315 .data = &sysctl_decnet_mem,
316 .maxlen = sizeof(sysctl_decnet_mem),
317 .mode = 0644,
318 .proc_handler = proc_doulongvec_minmax
319 },
320 {
321 .procname = "decnet_rmem",
322 .data = &sysctl_decnet_rmem,
323 .maxlen = sizeof(sysctl_decnet_rmem),
324 .mode = 0644,
325 .proc_handler = proc_dointvec,
326 },
327 {
328 .procname = "decnet_wmem",
329 .data = &sysctl_decnet_wmem,
330 .maxlen = sizeof(sysctl_decnet_wmem),
331 .mode = 0644,
332 .proc_handler = proc_dointvec,
333 },
334 {
335 .procname = "debug",
336 .data = &decnet_debug_level,
337 .maxlen = sizeof(int),
338 .mode = 0644,
339 .proc_handler = proc_dointvec,
340 },
341 { }
342 };
343
dn_register_sysctl(void)344 void dn_register_sysctl(void)
345 {
346 dn_table_header = register_net_sysctl(&init_net, "net/decnet", dn_table);
347 }
348
dn_unregister_sysctl(void)349 void dn_unregister_sysctl(void)
350 {
351 unregister_net_sysctl_table(dn_table_header);
352 }
353
354 #else /* CONFIG_SYSCTL */
dn_unregister_sysctl(void)355 void dn_unregister_sysctl(void)
356 {
357 }
dn_register_sysctl(void)358 void dn_register_sysctl(void)
359 {
360 }
361
362 #endif
363