1 /*
2 * Generic address resultion entity
3 *
4 * Authors:
5 * net_random Alan Cox
6 * net_ratelimit Andi Kleen
7 * in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
8 *
9 * Created by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
17 #include <linux/module.h>
18 #include <linux/jiffies.h>
19 #include <linux/kernel.h>
20 #include <linux/ctype.h>
21 #include <linux/inet.h>
22 #include <linux/mm.h>
23 #include <linux/net.h>
24 #include <linux/string.h>
25 #include <linux/types.h>
26 #include <linux/percpu.h>
27 #include <linux/init.h>
28 #include <linux/ratelimit.h>
29 #include <linux/socket.h>
30
31 #include <net/sock.h>
32 #include <net/net_ratelimit.h>
33 #include <net/ipv6.h>
34
35 #include <asm/byteorder.h>
36 #include <linux/uaccess.h>
37
38 DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
39 /*
40 * All net warning printk()s should be guarded by this function.
41 */
net_ratelimit(void)42 int net_ratelimit(void)
43 {
44 return __ratelimit(&net_ratelimit_state);
45 }
46 EXPORT_SYMBOL(net_ratelimit);
47
48 /*
49 * Convert an ASCII string to binary IP.
50 * This is outside of net/ipv4/ because various code that uses IP addresses
51 * is otherwise not dependent on the TCP/IP stack.
52 */
53
in_aton(const char * str)54 __be32 in_aton(const char *str)
55 {
56 unsigned int l;
57 unsigned int val;
58 int i;
59
60 l = 0;
61 for (i = 0; i < 4; i++) {
62 l <<= 8;
63 if (*str != '\0') {
64 val = 0;
65 while (*str != '\0' && *str != '.' && *str != '\n') {
66 val *= 10;
67 val += *str - '0';
68 str++;
69 }
70 l |= val;
71 if (*str != '\0')
72 str++;
73 }
74 }
75 return htonl(l);
76 }
77 EXPORT_SYMBOL(in_aton);
78
79 #define IN6PTON_XDIGIT 0x00010000
80 #define IN6PTON_DIGIT 0x00020000
81 #define IN6PTON_COLON_MASK 0x00700000
82 #define IN6PTON_COLON_1 0x00100000 /* single : requested */
83 #define IN6PTON_COLON_2 0x00200000 /* second : requested */
84 #define IN6PTON_COLON_1_2 0x00400000 /* :: requested */
85 #define IN6PTON_DOT 0x00800000 /* . */
86 #define IN6PTON_DELIM 0x10000000
87 #define IN6PTON_NULL 0x20000000 /* first/tail */
88 #define IN6PTON_UNKNOWN 0x40000000
89
xdigit2bin(char c,int delim)90 static inline int xdigit2bin(char c, int delim)
91 {
92 int val;
93
94 if (c == delim || c == '\0')
95 return IN6PTON_DELIM;
96 if (c == ':')
97 return IN6PTON_COLON_MASK;
98 if (c == '.')
99 return IN6PTON_DOT;
100
101 val = hex_to_bin(c);
102 if (val >= 0)
103 return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0);
104
105 if (delim == -1)
106 return IN6PTON_DELIM;
107 return IN6PTON_UNKNOWN;
108 }
109
110 /**
111 * in4_pton - convert an IPv4 address from literal to binary representation
112 * @src: the start of the IPv4 address string
113 * @srclen: the length of the string, -1 means strlen(src)
114 * @dst: the binary (u8[4] array) representation of the IPv4 address
115 * @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter
116 * @end: A pointer to the end of the parsed string will be placed here
117 *
118 * Return one on success, return zero when any error occurs
119 * and @end will point to the end of the parsed string.
120 *
121 */
in4_pton(const char * src,int srclen,u8 * dst,int delim,const char ** end)122 int in4_pton(const char *src, int srclen,
123 u8 *dst,
124 int delim, const char **end)
125 {
126 const char *s;
127 u8 *d;
128 u8 dbuf[4];
129 int ret = 0;
130 int i;
131 int w = 0;
132
133 if (srclen < 0)
134 srclen = strlen(src);
135 s = src;
136 d = dbuf;
137 i = 0;
138 while (1) {
139 int c;
140 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
141 if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
142 goto out;
143 }
144 if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
145 if (w == 0)
146 goto out;
147 *d++ = w & 0xff;
148 w = 0;
149 i++;
150 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
151 if (i != 4)
152 goto out;
153 break;
154 }
155 goto cont;
156 }
157 w = (w * 10) + c;
158 if ((w & 0xffff) > 255) {
159 goto out;
160 }
161 cont:
162 if (i >= 4)
163 goto out;
164 s++;
165 srclen--;
166 }
167 ret = 1;
168 memcpy(dst, dbuf, sizeof(dbuf));
169 out:
170 if (end)
171 *end = s;
172 return ret;
173 }
174 EXPORT_SYMBOL(in4_pton);
175
176 /**
177 * in6_pton - convert an IPv6 address from literal to binary representation
178 * @src: the start of the IPv6 address string
179 * @srclen: the length of the string, -1 means strlen(src)
180 * @dst: the binary (u8[16] array) representation of the IPv6 address
181 * @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter
182 * @end: A pointer to the end of the parsed string will be placed here
183 *
184 * Return one on success, return zero when any error occurs
185 * and @end will point to the end of the parsed string.
186 *
187 */
in6_pton(const char * src,int srclen,u8 * dst,int delim,const char ** end)188 int in6_pton(const char *src, int srclen,
189 u8 *dst,
190 int delim, const char **end)
191 {
192 const char *s, *tok = NULL;
193 u8 *d, *dc = NULL;
194 u8 dbuf[16];
195 int ret = 0;
196 int i;
197 int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
198 int w = 0;
199
200 memset(dbuf, 0, sizeof(dbuf));
201
202 s = src;
203 d = dbuf;
204 if (srclen < 0)
205 srclen = strlen(src);
206
207 while (1) {
208 int c;
209
210 c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
211 if (!(c & state))
212 goto out;
213 if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
214 /* process one 16-bit word */
215 if (!(state & IN6PTON_NULL)) {
216 *d++ = (w >> 8) & 0xff;
217 *d++ = w & 0xff;
218 }
219 w = 0;
220 if (c & IN6PTON_DELIM) {
221 /* We've processed last word */
222 break;
223 }
224 /*
225 * COLON_1 => XDIGIT
226 * COLON_2 => XDIGIT|DELIM
227 * COLON_1_2 => COLON_2
228 */
229 switch (state & IN6PTON_COLON_MASK) {
230 case IN6PTON_COLON_2:
231 dc = d;
232 state = IN6PTON_XDIGIT | IN6PTON_DELIM;
233 if (dc - dbuf >= sizeof(dbuf))
234 state |= IN6PTON_NULL;
235 break;
236 case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
237 state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
238 break;
239 case IN6PTON_COLON_1:
240 state = IN6PTON_XDIGIT;
241 break;
242 case IN6PTON_COLON_1_2:
243 state = IN6PTON_COLON_2;
244 break;
245 default:
246 state = 0;
247 }
248 tok = s + 1;
249 goto cont;
250 }
251
252 if (c & IN6PTON_DOT) {
253 ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
254 if (ret > 0) {
255 d += 4;
256 break;
257 }
258 goto out;
259 }
260
261 w = (w << 4) | (0xff & c);
262 state = IN6PTON_COLON_1 | IN6PTON_DELIM;
263 if (!(w & 0xf000)) {
264 state |= IN6PTON_XDIGIT;
265 }
266 if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
267 state |= IN6PTON_COLON_1_2;
268 state &= ~IN6PTON_DELIM;
269 }
270 if (d + 2 >= dbuf + sizeof(dbuf)) {
271 state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
272 }
273 cont:
274 if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
275 d + 4 == dbuf + sizeof(dbuf)) {
276 state |= IN6PTON_DOT;
277 }
278 if (d >= dbuf + sizeof(dbuf)) {
279 state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
280 }
281 s++;
282 srclen--;
283 }
284
285 i = 15; d--;
286
287 if (dc) {
288 while (d >= dc)
289 dst[i--] = *d--;
290 while (i >= dc - dbuf)
291 dst[i--] = 0;
292 while (i >= 0)
293 dst[i--] = *d--;
294 } else
295 memcpy(dst, dbuf, sizeof(dbuf));
296
297 ret = 1;
298 out:
299 if (end)
300 *end = s;
301 return ret;
302 }
303 EXPORT_SYMBOL(in6_pton);
304
inet4_pton(const char * src,u16 port_num,struct sockaddr_storage * addr)305 static int inet4_pton(const char *src, u16 port_num,
306 struct sockaddr_storage *addr)
307 {
308 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
309 int srclen = strlen(src);
310
311 if (srclen > INET_ADDRSTRLEN)
312 return -EINVAL;
313
314 if (in4_pton(src, srclen, (u8 *)&addr4->sin_addr.s_addr,
315 '\n', NULL) == 0)
316 return -EINVAL;
317
318 addr4->sin_family = AF_INET;
319 addr4->sin_port = htons(port_num);
320
321 return 0;
322 }
323
inet6_pton(struct net * net,const char * src,u16 port_num,struct sockaddr_storage * addr)324 static int inet6_pton(struct net *net, const char *src, u16 port_num,
325 struct sockaddr_storage *addr)
326 {
327 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
328 const char *scope_delim;
329 int srclen = strlen(src);
330
331 if (srclen > INET6_ADDRSTRLEN)
332 return -EINVAL;
333
334 if (in6_pton(src, srclen, (u8 *)&addr6->sin6_addr.s6_addr,
335 '%', &scope_delim) == 0)
336 return -EINVAL;
337
338 if (ipv6_addr_type(&addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL &&
339 src + srclen != scope_delim && *scope_delim == '%') {
340 struct net_device *dev;
341 char scope_id[16];
342 size_t scope_len = min_t(size_t, sizeof(scope_id) - 1,
343 src + srclen - scope_delim - 1);
344
345 memcpy(scope_id, scope_delim + 1, scope_len);
346 scope_id[scope_len] = '\0';
347
348 dev = dev_get_by_name(net, scope_id);
349 if (dev) {
350 addr6->sin6_scope_id = dev->ifindex;
351 dev_put(dev);
352 } else if (kstrtouint(scope_id, 0, &addr6->sin6_scope_id)) {
353 return -EINVAL;
354 }
355 }
356
357 addr6->sin6_family = AF_INET6;
358 addr6->sin6_port = htons(port_num);
359
360 return 0;
361 }
362
363 /**
364 * inet_pton_with_scope - convert an IPv4/IPv6 and port to socket address
365 * @net: net namespace (used for scope handling)
366 * @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either
367 * @src: the start of the address string
368 * @port: the start of the port string (or NULL for none)
369 * @addr: output socket address
370 *
371 * Return zero on success, return errno when any error occurs.
372 */
inet_pton_with_scope(struct net * net,__kernel_sa_family_t af,const char * src,const char * port,struct sockaddr_storage * addr)373 int inet_pton_with_scope(struct net *net, __kernel_sa_family_t af,
374 const char *src, const char *port, struct sockaddr_storage *addr)
375 {
376 u16 port_num;
377 int ret = -EINVAL;
378
379 if (port) {
380 if (kstrtou16(port, 0, &port_num))
381 return -EINVAL;
382 } else {
383 port_num = 0;
384 }
385
386 switch (af) {
387 case AF_INET:
388 ret = inet4_pton(src, port_num, addr);
389 break;
390 case AF_INET6:
391 ret = inet6_pton(net, src, port_num, addr);
392 break;
393 case AF_UNSPEC:
394 ret = inet4_pton(src, port_num, addr);
395 if (ret)
396 ret = inet6_pton(net, src, port_num, addr);
397 break;
398 default:
399 pr_err("unexpected address family %d\n", af);
400 }
401
402 return ret;
403 }
404 EXPORT_SYMBOL(inet_pton_with_scope);
405
inet_addr_is_any(struct sockaddr * addr)406 bool inet_addr_is_any(struct sockaddr *addr)
407 {
408 if (addr->sa_family == AF_INET6) {
409 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
410 const struct sockaddr_in6 in6_any =
411 { .sin6_addr = IN6ADDR_ANY_INIT };
412
413 if (!memcmp(in6->sin6_addr.s6_addr,
414 in6_any.sin6_addr.s6_addr, 16))
415 return true;
416 } else if (addr->sa_family == AF_INET) {
417 struct sockaddr_in *in = (struct sockaddr_in *)addr;
418
419 if (in->sin_addr.s_addr == htonl(INADDR_ANY))
420 return true;
421 } else {
422 pr_warn("unexpected address family %u\n", addr->sa_family);
423 }
424
425 return false;
426 }
427 EXPORT_SYMBOL(inet_addr_is_any);
428
inet_proto_csum_replace4(__sum16 * sum,struct sk_buff * skb,__be32 from,__be32 to,bool pseudohdr)429 void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
430 __be32 from, __be32 to, bool pseudohdr)
431 {
432 if (skb->ip_summed != CHECKSUM_PARTIAL) {
433 csum_replace4(sum, from, to);
434 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
435 skb->csum = ~csum_add(csum_sub(~(skb->csum),
436 (__force __wsum)from),
437 (__force __wsum)to);
438 } else if (pseudohdr)
439 *sum = ~csum_fold(csum_add(csum_sub(csum_unfold(*sum),
440 (__force __wsum)from),
441 (__force __wsum)to));
442 }
443 EXPORT_SYMBOL(inet_proto_csum_replace4);
444
inet_proto_csum_replace16(__sum16 * sum,struct sk_buff * skb,const __be32 * from,const __be32 * to,bool pseudohdr)445 void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
446 const __be32 *from, const __be32 *to,
447 bool pseudohdr)
448 {
449 __be32 diff[] = {
450 ~from[0], ~from[1], ~from[2], ~from[3],
451 to[0], to[1], to[2], to[3],
452 };
453 if (skb->ip_summed != CHECKSUM_PARTIAL) {
454 *sum = csum_fold(csum_partial(diff, sizeof(diff),
455 ~csum_unfold(*sum)));
456 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
457 skb->csum = ~csum_partial(diff, sizeof(diff),
458 ~skb->csum);
459 } else if (pseudohdr)
460 *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
461 csum_unfold(*sum)));
462 }
463 EXPORT_SYMBOL(inet_proto_csum_replace16);
464
inet_proto_csum_replace_by_diff(__sum16 * sum,struct sk_buff * skb,__wsum diff,bool pseudohdr)465 void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,
466 __wsum diff, bool pseudohdr)
467 {
468 if (skb->ip_summed != CHECKSUM_PARTIAL) {
469 *sum = csum_fold(csum_add(diff, ~csum_unfold(*sum)));
470 if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
471 skb->csum = ~csum_add(diff, ~skb->csum);
472 } else if (pseudohdr) {
473 *sum = ~csum_fold(csum_add(diff, csum_unfold(*sum)));
474 }
475 }
476 EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);
477
