summaryrefslogtreecommitdiff
path: root/net/core/utils.c
blob: 2a597ac7808e2c9b3e68b9ca03ffe0dd4a0d9853 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
/*
 *	Generic address resultion entity
 *
 *	Authors:
 *	net_random Alan Cox
 *	net_ratelimit Andi Kleen
 *	in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
 *
 *	Created by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/inet.h>
#include <linux/mm.h>
#include <linux/net.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/ratelimit.h>
#include <linux/socket.h>

#include <net/sock.h>
#include <net/net_ratelimit.h>
#include <net/ipv6.h>

#include <asm/byteorder.h>
#include <linux/uaccess.h>

DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
/*
 * All net warning printk()s should be guarded by this function.
 */
int net_ratelimit(void)
{
	return __ratelimit(&net_ratelimit_state);
}
EXPORT_SYMBOL(net_ratelimit);

/*
 * Convert an ASCII string to binary IP.
 * This is outside of net/ipv4/ because various code that uses IP addresses
 * is otherwise not dependent on the TCP/IP stack.
 */

__be32 in_aton(const char *str)
{
	unsigned int l;
	unsigned int val;
	int i;

	l = 0;
	for (i = 0; i < 4; i++)	{
		l <<= 8;
		if (*str != '\0') {
			val = 0;
			while (*str != '\0' && *str != '.' && *str != '\n') {
				val *= 10;
				val += *str - '0';
				str++;
			}
			l |= val;
			if (*str != '\0')
				str++;
		}
	}
	return htonl(l);
}
EXPORT_SYMBOL(in_aton);

#define IN6PTON_XDIGIT		0x00010000
#define IN6PTON_DIGIT		0x00020000
#define IN6PTON_COLON_MASK	0x00700000
#define IN6PTON_COLON_1		0x00100000	/* single : requested */
#define IN6PTON_COLON_2		0x00200000	/* second : requested */
#define IN6PTON_COLON_1_2	0x00400000	/* :: requested */
#define IN6PTON_DOT		0x00800000	/* . */
#define IN6PTON_DELIM		0x10000000
#define IN6PTON_NULL		0x20000000	/* first/tail */
#define IN6PTON_UNKNOWN		0x40000000

static inline int xdigit2bin(char c, int delim)
{
	int val;

	if (c == delim || c == '\0')
		return IN6PTON_DELIM;
	if (c == ':')
		return IN6PTON_COLON_MASK;
	if (c == '.')
		return IN6PTON_DOT;

	val = hex_to_bin(c);
	if (val >= 0)
		return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0);

	if (delim == -1)
		return IN6PTON_DELIM;
	return IN6PTON_UNKNOWN;
}

/**
 * in4_pton - convert an IPv4 address from literal to binary representation
 * @src: the start of the IPv4 address string
 * @srclen: the length of the string, -1 means strlen(src)
 * @dst: the binary (u8[4] array) representation of the IPv4 address
 * @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter
 * @end: A pointer to the end of the parsed string will be placed here
 *
 * Return one on success, return zero when any error occurs
 * and @end will point to the end of the parsed string.
 *
 */
int in4_pton(const char *src, int srclen,
	     u8 *dst,
	     int delim, const char **end)
{
	const char *s;
	u8 *d;
	u8 dbuf[4];
	int ret = 0;
	int i;
	int w = 0;

	if (srclen < 0)
		srclen = strlen(src);
	s = src;
	d = dbuf;
	i = 0;
	while (1) {
		int c;
		c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
		if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
			goto out;
		}
		if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
			if (w == 0)
				goto out;
			*d++ = w & 0xff;
			w = 0;
			i++;
			if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
				if (i != 4)
					goto out;
				break;
			}
			goto cont;
		}
		w = (w * 10) + c;
		if ((w & 0xffff) > 255) {
			goto out;
		}
cont:
		if (i >= 4)
			goto out;
		s++;
		srclen--;
	}
	ret = 1;
	memcpy(dst, dbuf, sizeof(dbuf));
out:
	if (end)
		*end = s;
	return ret;
}
EXPORT_SYMBOL(in4_pton);

/**
 * in6_pton - convert an IPv6 address from literal to binary representation
 * @src: the start of the IPv6 address string
 * @srclen: the length of the string, -1 means strlen(src)
 * @dst: the binary (u8[16] array) representation of the IPv6 address
 * @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter
 * @end: A pointer to the end of the parsed string will be placed here
 *
 * Return one on success, return zero when any error occurs
 * and @end will point to the end of the parsed string.
 *
 */
int in6_pton(const char *src, int srclen,
	     u8 *dst,
	     int delim, const char **end)
{
	const char *s, *tok = NULL;
	u8 *d, *dc = NULL;
	u8 dbuf[16];
	int ret = 0;
	int i;
	int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
	int w = 0;

	memset(dbuf, 0, sizeof(dbuf));

	s = src;
	d = dbuf;
	if (srclen < 0)
		srclen = strlen(src);

	while (1) {
		int c;

		c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
		if (!(c & state))
			goto out;
		if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
			/* process one 16-bit word */
			if (!(state & IN6PTON_NULL)) {
				*d++ = (w >> 8) & 0xff;
				*d++ = w & 0xff;
			}
			w = 0;
			if (c & IN6PTON_DELIM) {
				/* We've processed last word */
				break;
			}
			/*
			 * COLON_1 => XDIGIT
			 * COLON_2 => XDIGIT|DELIM
			 * COLON_1_2 => COLON_2
			 */
			switch (state & IN6PTON_COLON_MASK) {
			case IN6PTON_COLON_2:
				dc = d;
				state = IN6PTON_XDIGIT | IN6PTON_DELIM;
				if (dc - dbuf >= sizeof(dbuf))
					state |= IN6PTON_NULL;
				break;
			case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
				state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
				break;
			case IN6PTON_COLON_1:
				state = IN6PTON_XDIGIT;
				break;
			case IN6PTON_COLON_1_2:
				state = IN6PTON_COLON_2;
				break;
			default:
				state = 0;
			}
			tok = s + 1;
			goto cont;
		}

		if (c & IN6PTON_DOT) {
			ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
			if (ret > 0) {
				d += 4;
				break;
			}
			goto out;
		}

		w = (w << 4) | (0xff & c);
		state = IN6PTON_COLON_1 | IN6PTON_DELIM;
		if (!(w & 0xf000)) {
			state |= IN6PTON_XDIGIT;
		}
		if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
			state |= IN6PTON_COLON_1_2;
			state &= ~IN6PTON_DELIM;
		}
		if (d + 2 >= dbuf + sizeof(dbuf)) {
			state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
		}
cont:
		if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
		    d + 4 == dbuf + sizeof(dbuf)) {
			state |= IN6PTON_DOT;
		}
		if (d >= dbuf + sizeof(dbuf)) {
			state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
		}
		s++;
		srclen--;
	}

	i = 15; d--;

	if (dc) {
		while (d >= dc)
			dst[i--] = *d--;
		while (i >= dc - dbuf)
			dst[i--] = 0;
		while (i >= 0)
			dst[i--] = *d--;
	} else
		memcpy(dst, dbuf, sizeof(dbuf));

	ret = 1;
out:
	if (end)
		*end = s;
	return ret;
}
EXPORT_SYMBOL(in6_pton);

static int inet4_pton(const char *src, u16 port_num,
		struct sockaddr_storage *addr)
{
	struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
	int srclen = strlen(src);

	if (srclen > INET_ADDRSTRLEN)
		return -EINVAL;

	if (in4_pton(src, srclen, (u8 *)&addr4->sin_addr.s_addr,
		     '\n', NULL) == 0)
		return -EINVAL;

	addr4->sin_family = AF_INET;
	addr4->sin_port = htons(port_num);

	return 0;
}

static int inet6_pton(struct net *net, const char *src, u16 port_num,
		struct sockaddr_storage *addr)
{
	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
	const char *scope_delim;
	int srclen = strlen(src);

	if (srclen > INET6_ADDRSTRLEN)
		return -EINVAL;

	if (in6_pton(src, srclen, (u8 *)&addr6->sin6_addr.s6_addr,
		     '%', &scope_delim) == 0)
		return -EINVAL;

	if (ipv6_addr_type(&addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL &&
	    src + srclen != scope_delim && *scope_delim == '%') {
		struct net_device *dev;
		char scope_id[16];
		size_t scope_len = min_t(size_t, sizeof(scope_id) - 1,
					 src + srclen - scope_delim - 1);

		memcpy(scope_id, scope_delim + 1, scope_len);
		scope_id[scope_len] = '\0';

		dev = dev_get_by_name(net, scope_id);
		if (dev) {
			addr6->sin6_scope_id = dev->ifindex;
			dev_put(dev);
		} else if (kstrtouint(scope_id, 0, &addr6->sin6_scope_id)) {
			return -EINVAL;
		}
	}

	addr6->sin6_family = AF_INET6;
	addr6->sin6_port = htons(port_num);

	return 0;
}

/**
 * inet_pton_with_scope - convert an IPv4/IPv6 and port to socket address
 * @net: net namespace (used for scope handling)
 * @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either
 * @src: the start of the address string
 * @port: the start of the port string (or NULL for none)
 * @addr: output socket address
 *
 * Return zero on success, return errno when any error occurs.
 */
int inet_pton_with_scope(struct net *net, __kernel_sa_family_t af,
		const char *src, const char *port, struct sockaddr_storage *addr)
{
	u16 port_num;
	int ret = -EINVAL;

	if (port) {
		if (kstrtou16(port, 0, &port_num))
			return -EINVAL;
	} else {
		port_num = 0;
	}

	switch (af) {
	case AF_INET:
		ret = inet4_pton(src, port_num, addr);
		break;
	case AF_INET6:
		ret = inet6_pton(net, src, port_num, addr);
		break;
	case AF_UNSPEC:
		ret = inet4_pton(src, port_num, addr);
		if (ret)
			ret = inet6_pton(net, src, port_num, addr);
		break;
	default:
		pr_err("unexpected address family %d\n", af);
	}

	return ret;
}
EXPORT_SYMBOL(inet_pton_with_scope);

bool inet_addr_is_any(struct sockaddr *addr)
{
	if (addr->sa_family == AF_INET6) {
		struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
		const struct sockaddr_in6 in6_any =
			{ .sin6_addr = IN6ADDR_ANY_INIT };

		if (!memcmp(in6->sin6_addr.s6_addr,
			    in6_any.sin6_addr.s6_addr, 16))
			return true;
	} else if (addr->sa_family == AF_INET) {
		struct sockaddr_in *in = (struct sockaddr_in *)addr;

		if (in->sin_addr.s_addr == htonl(INADDR_ANY))
			return true;
	} else {
		pr_warn("unexpected address family %u\n", addr->sa_family);
	}

	return false;
}
EXPORT_SYMBOL(inet_addr_is_any);

void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
			      __be32 from, __be32 to, bool pseudohdr)
{
	if (skb->ip_summed != CHECKSUM_PARTIAL) {
		csum_replace4(sum, from, to);
		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
			skb->csum = ~csum_add(csum_sub(~(skb->csum),
						       (__force __wsum)from),
					      (__force __wsum)to);
	} else if (pseudohdr)
		*sum = ~csum_fold(csum_add(csum_sub(csum_unfold(*sum),
						    (__force __wsum)from),
					   (__force __wsum)to));
}
EXPORT_SYMBOL(inet_proto_csum_replace4);

void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
			       const __be32 *from, const __be32 *to,
			       bool pseudohdr)
{
	__be32 diff[] = {
		~from[0], ~from[1], ~from[2], ~from[3],
		to[0], to[1], to[2], to[3],
	};
	if (skb->ip_summed != CHECKSUM_PARTIAL) {
		*sum = csum_fold(csum_partial(diff, sizeof(diff),
				 ~csum_unfold(*sum)));
		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
			skb->csum = ~csum_partial(diff, sizeof(diff),
						  ~skb->csum);
	} else if (pseudohdr)
		*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
				  csum_unfold(*sum)));
}
EXPORT_SYMBOL(inet_proto_csum_replace16);

void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,
				     __wsum diff, bool pseudohdr)
{
	if (skb->ip_summed != CHECKSUM_PARTIAL) {
		*sum = csum_fold(csum_add(diff, ~csum_unfold(*sum)));
		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
			skb->csum = ~csum_add(diff, ~skb->csum);
	} else if (pseudohdr) {
		*sum = ~csum_fold(csum_add(diff, csum_unfold(*sum)));
	}
}
EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);