1 /*
2  * DECnet       An implementation of the DECnet protocol suite for the LINUX
3  *              operating system.  DECnet is implemented using the  BSD Socket
4  *              interface as the means of communication with the user level.
5  *
6  *              DECnet sysctl support functions
7  *
8  * Author:      Steve Whitehouse <SteveW@ACM.org>
9  *
10  *
11  * Changes:
12  * Steve Whitehouse - C99 changes and default device handling
13  * Steve Whitehouse - Memory buffer settings, like the tcp ones
14  *
15  */
16 #include <linux/mm.h>
17 #include <linux/sysctl.h>
18 #include <linux/fs.h>
19 #include <linux/netdevice.h>
20 #include <linux/string.h>
21 #include <net/neighbour.h>
22 #include <net/dst.h>
23 #include <net/flow.h>
24 
25 #include <asm/uaccess.h>
26 
27 #include <net/dn.h>
28 #include <net/dn_dev.h>
29 #include <net/dn_route.h>
30 
31 
32 int decnet_debug_level;
33 int decnet_time_wait = 30;
34 int decnet_dn_count = 1;
35 int decnet_di_count = 3;
36 int decnet_dr_count = 3;
37 int decnet_log_martians = 1;
38 int decnet_no_fc_max_cwnd = NSP_MIN_WINDOW;
39 
40 /* Reasonable defaults, I hope, based on tcp's defaults */
41 long sysctl_decnet_mem[3] = { 768 << 3, 1024 << 3, 1536 << 3 };
42 int sysctl_decnet_wmem[3] = { 4 * 1024, 16 * 1024, 128 * 1024 };
43 int sysctl_decnet_rmem[3] = { 4 * 1024, 87380, 87380 * 2 };
44 
45 #ifdef CONFIG_SYSCTL
46 extern int decnet_dst_gc_interval;
47 static int min_decnet_time_wait[] = { 5 };
48 static int max_decnet_time_wait[] = { 600 };
49 static int min_state_count[] = { 1 };
50 static int max_state_count[] = { NSP_MAXRXTSHIFT };
51 static int min_decnet_dst_gc_interval[] = { 1 };
52 static int max_decnet_dst_gc_interval[] = { 60 };
53 static int min_decnet_no_fc_max_cwnd[] = { NSP_MIN_WINDOW };
54 static int max_decnet_no_fc_max_cwnd[] = { NSP_MAX_WINDOW };
55 static char node_name[7] = "???";
56 
57 static struct ctl_table_header *dn_table_header = NULL;
58 
59 /*
60  * ctype.h :-)
61  */
62 #define ISNUM(x) (((x) >= '0') && ((x) <= '9'))
63 #define ISLOWER(x) (((x) >= 'a') && ((x) <= 'z'))
64 #define ISUPPER(x) (((x) >= 'A') && ((x) <= 'Z'))
65 #define ISALPHA(x) (ISLOWER(x) || ISUPPER(x))
66 #define INVALID_END_CHAR(x) (ISNUM(x) || ISALPHA(x))
67 
strip_it(char * str)68 static void strip_it(char *str)
69 {
70 	for(;;) {
71 		switch (*str) {
72 		case ' ':
73 		case '\n':
74 		case '\r':
75 		case ':':
76 			*str = 0;
77 			/* Fallthrough */
78 		case 0:
79 			return;
80 		}
81 		str++;
82 	}
83 }
84 
85 /*
86  * Simple routine to parse an ascii DECnet address
87  * into a network order address.
88  */
parse_addr(__le16 * addr,char * str)89 static int parse_addr(__le16 *addr, char *str)
90 {
91 	__u16 area, node;
92 
93 	while(*str && !ISNUM(*str)) str++;
94 
95 	if (*str == 0)
96 		return -1;
97 
98 	area = (*str++ - '0');
99 	if (ISNUM(*str)) {
100 		area *= 10;
101 		area += (*str++ - '0');
102 	}
103 
104 	if (*str++ != '.')
105 		return -1;
106 
107 	if (!ISNUM(*str))
108 		return -1;
109 
110 	node = *str++ - '0';
111 	if (ISNUM(*str)) {
112 		node *= 10;
113 		node += (*str++ - '0');
114 	}
115 	if (ISNUM(*str)) {
116 		node *= 10;
117 		node += (*str++ - '0');
118 	}
119 	if (ISNUM(*str)) {
120 		node *= 10;
121 		node += (*str++ - '0');
122 	}
123 
124 	if ((node > 1023) || (area > 63))
125 		return -1;
126 
127 	if (INVALID_END_CHAR(*str))
128 		return -1;
129 
130 	*addr = cpu_to_le16((area << 10) | node);
131 
132 	return 0;
133 }
134 
dn_node_address_handler(ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)135 static int dn_node_address_handler(ctl_table *table, int write,
136 				void __user *buffer,
137 				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 
151 		if (copy_from_user(addr, buffer, len))
152 			return -EFAULT;
153 
154 		addr[len] = 0;
155 		strip_it(addr);
156 
157 		if (parse_addr(&dnaddr, addr))
158 			return -EINVAL;
159 
160 		dn_dev_devices_off();
161 
162 		decnet_address = dnaddr;
163 
164 		dn_dev_devices_on();
165 
166 		*ppos += len;
167 
168 		return 0;
169 	}
170 
171 	dn_addr2asc(le16_to_cpu(decnet_address), addr);
172 	len = strlen(addr);
173 	addr[len++] = '\n';
174 
175 	if (len > *lenp) len = *lenp;
176 
177 	if (copy_to_user(buffer, addr, len))
178 		return -EFAULT;
179 
180 	*lenp = len;
181 	*ppos += len;
182 
183 	return 0;
184 }
185 
dn_def_dev_handler(ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)186 static int dn_def_dev_handler(ctl_table *table, int write,
187 				void __user *buffer,
188 				size_t *lenp, loff_t *ppos)
189 {
190 	size_t len;
191 	struct net_device *dev;
192 	char devname[17];
193 
194 	if (!*lenp || (*ppos && !write)) {
195 		*lenp = 0;
196 		return 0;
197 	}
198 
199 	if (write) {
200 		if (*lenp > 16)
201 			return -E2BIG;
202 
203 		if (copy_from_user(devname, buffer, *lenp))
204 			return -EFAULT;
205 
206 		devname[*lenp] = 0;
207 		strip_it(devname);
208 
209 		dev = dev_get_by_name(&init_net, devname);
210 		if (dev == NULL)
211 			return -ENODEV;
212 
213 		if (dev->dn_ptr == NULL) {
214 			dev_put(dev);
215 			return -ENODEV;
216 		}
217 
218 		if (dn_dev_set_default(dev, 1)) {
219 			dev_put(dev);
220 			return -ENODEV;
221 		}
222 		*ppos += *lenp;
223 
224 		return 0;
225 	}
226 
227 	dev = dn_dev_get_default();
228 	if (dev == NULL) {
229 		*lenp = 0;
230 		return 0;
231 	}
232 
233 	strcpy(devname, dev->name);
234 	dev_put(dev);
235 	len = strlen(devname);
236 	devname[len++] = '\n';
237 
238 	if (len > *lenp) len = *lenp;
239 
240 	if (copy_to_user(buffer, devname, len))
241 		return -EFAULT;
242 
243 	*lenp = len;
244 	*ppos += len;
245 
246 	return 0;
247 }
248 
249 static ctl_table dn_table[] = {
250 	{
251 		.procname = "node_address",
252 		.maxlen = 7,
253 		.mode = 0644,
254 		.proc_handler = dn_node_address_handler,
255 	},
256 	{
257 		.procname = "node_name",
258 		.data = node_name,
259 		.maxlen = 7,
260 		.mode = 0644,
261 		.proc_handler = proc_dostring,
262 	},
263 	{
264 		.procname = "default_device",
265 		.maxlen = 16,
266 		.mode = 0644,
267 		.proc_handler = dn_def_dev_handler,
268 	},
269 	{
270 		.procname = "time_wait",
271 		.data = &decnet_time_wait,
272 		.maxlen = sizeof(int),
273 		.mode = 0644,
274 		.proc_handler = proc_dointvec_minmax,
275 		.extra1 = &min_decnet_time_wait,
276 		.extra2 = &max_decnet_time_wait
277 	},
278 	{
279 		.procname = "dn_count",
280 		.data = &decnet_dn_count,
281 		.maxlen = sizeof(int),
282 		.mode = 0644,
283 		.proc_handler = proc_dointvec_minmax,
284 		.extra1 = &min_state_count,
285 		.extra2 = &max_state_count
286 	},
287 	{
288 		.procname = "di_count",
289 		.data = &decnet_di_count,
290 		.maxlen = sizeof(int),
291 		.mode = 0644,
292 		.proc_handler = proc_dointvec_minmax,
293 		.extra1 = &min_state_count,
294 		.extra2 = &max_state_count
295 	},
296 	{
297 		.procname = "dr_count",
298 		.data = &decnet_dr_count,
299 		.maxlen = sizeof(int),
300 		.mode = 0644,
301 		.proc_handler = proc_dointvec_minmax,
302 		.extra1 = &min_state_count,
303 		.extra2 = &max_state_count
304 	},
305 	{
306 		.procname = "dst_gc_interval",
307 		.data = &decnet_dst_gc_interval,
308 		.maxlen = sizeof(int),
309 		.mode = 0644,
310 		.proc_handler = proc_dointvec_minmax,
311 		.extra1 = &min_decnet_dst_gc_interval,
312 		.extra2 = &max_decnet_dst_gc_interval
313 	},
314 	{
315 		.procname = "no_fc_max_cwnd",
316 		.data = &decnet_no_fc_max_cwnd,
317 		.maxlen = sizeof(int),
318 		.mode = 0644,
319 		.proc_handler = proc_dointvec_minmax,
320 		.extra1 = &min_decnet_no_fc_max_cwnd,
321 		.extra2 = &max_decnet_no_fc_max_cwnd
322 	},
323        {
324 		.procname = "decnet_mem",
325 		.data = &sysctl_decnet_mem,
326 		.maxlen = sizeof(sysctl_decnet_mem),
327 		.mode = 0644,
328 		.proc_handler = proc_doulongvec_minmax
329 	},
330 	{
331 		.procname = "decnet_rmem",
332 		.data = &sysctl_decnet_rmem,
333 		.maxlen = sizeof(sysctl_decnet_rmem),
334 		.mode = 0644,
335 		.proc_handler = proc_dointvec,
336 	},
337 	{
338 		.procname = "decnet_wmem",
339 		.data = &sysctl_decnet_wmem,
340 		.maxlen = sizeof(sysctl_decnet_wmem),
341 		.mode = 0644,
342 		.proc_handler = proc_dointvec,
343 	},
344 	{
345 		.procname = "debug",
346 		.data = &decnet_debug_level,
347 		.maxlen = sizeof(int),
348 		.mode = 0644,
349 		.proc_handler = proc_dointvec,
350 	},
351 	{ }
352 };
353 
354 static struct ctl_path dn_path[] = {
355 	{ .procname = "net", },
356 	{ .procname = "decnet", },
357 	{ }
358 };
359 
dn_register_sysctl(void)360 void dn_register_sysctl(void)
361 {
362 	dn_table_header = register_sysctl_paths(dn_path, dn_table);
363 }
364 
dn_unregister_sysctl(void)365 void dn_unregister_sysctl(void)
366 {
367 	unregister_sysctl_table(dn_table_header);
368 }
369 
370 #else  /* CONFIG_SYSCTL */
dn_unregister_sysctl(void)371 void dn_unregister_sysctl(void)
372 {
373 }
dn_register_sysctl(void)374 void dn_register_sysctl(void)
375 {
376 }
377 
378 #endif
379