1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Generic address resultion entity |
4 | * |
5 | * Authors: |
6 | * net_random Alan Cox |
7 | * net_ratelimit Andi Kleen |
8 | * in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project |
9 | * |
10 | * Created by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
11 | */ |
12 | |
13 | #include <linux/module.h> |
14 | #include <linux/jiffies.h> |
15 | #include <linux/kernel.h> |
16 | #include <linux/ctype.h> |
17 | #include <linux/inet.h> |
18 | #include <linux/mm.h> |
19 | #include <linux/net.h> |
20 | #include <linux/string.h> |
21 | #include <linux/types.h> |
22 | #include <linux/percpu.h> |
23 | #include <linux/init.h> |
24 | #include <linux/ratelimit.h> |
25 | #include <linux/socket.h> |
26 | |
27 | #include <net/sock.h> |
28 | #include <net/net_ratelimit.h> |
29 | #include <net/ipv6.h> |
30 | |
31 | #include <asm/byteorder.h> |
32 | #include <linux/uaccess.h> |
33 | |
34 | DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10); |
35 | /* |
36 | * All net warning printk()s should be guarded by this function. |
37 | */ |
38 | int net_ratelimit(void) |
39 | { |
40 | return __ratelimit(&net_ratelimit_state); |
41 | } |
42 | EXPORT_SYMBOL(net_ratelimit); |
43 | |
44 | /* |
45 | * Convert an ASCII string to binary IP. |
46 | * This is outside of net/ipv4/ because various code that uses IP addresses |
47 | * is otherwise not dependent on the TCP/IP stack. |
48 | */ |
49 | |
50 | __be32 in_aton(const char *str) |
51 | { |
52 | unsigned int l; |
53 | unsigned int val; |
54 | int i; |
55 | |
56 | l = 0; |
57 | for (i = 0; i < 4; i++) { |
58 | l <<= 8; |
59 | if (*str != '\0') { |
60 | val = 0; |
61 | while (*str != '\0' && *str != '.' && *str != '\n') { |
62 | val *= 10; |
63 | val += *str - '0'; |
64 | str++; |
65 | } |
66 | l |= val; |
67 | if (*str != '\0') |
68 | str++; |
69 | } |
70 | } |
71 | return htonl(l); |
72 | } |
73 | EXPORT_SYMBOL(in_aton); |
74 | |
75 | #define IN6PTON_XDIGIT 0x00010000 |
76 | #define IN6PTON_DIGIT 0x00020000 |
77 | #define IN6PTON_COLON_MASK 0x00700000 |
78 | #define IN6PTON_COLON_1 0x00100000 /* single : requested */ |
79 | #define IN6PTON_COLON_2 0x00200000 /* second : requested */ |
80 | #define IN6PTON_COLON_1_2 0x00400000 /* :: requested */ |
81 | #define IN6PTON_DOT 0x00800000 /* . */ |
82 | #define IN6PTON_DELIM 0x10000000 |
83 | #define IN6PTON_NULL 0x20000000 /* first/tail */ |
84 | #define IN6PTON_UNKNOWN 0x40000000 |
85 | |
86 | static inline int xdigit2bin(char c, int delim) |
87 | { |
88 | int val; |
89 | |
90 | if (c == delim || c == '\0') |
91 | return IN6PTON_DELIM; |
92 | if (c == ':') |
93 | return IN6PTON_COLON_MASK; |
94 | if (c == '.') |
95 | return IN6PTON_DOT; |
96 | |
97 | val = hex_to_bin(ch: c); |
98 | if (val >= 0) |
99 | return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0); |
100 | |
101 | if (delim == -1) |
102 | return IN6PTON_DELIM; |
103 | return IN6PTON_UNKNOWN; |
104 | } |
105 | |
106 | /** |
107 | * in4_pton - convert an IPv4 address from literal to binary representation |
108 | * @src: the start of the IPv4 address string |
109 | * @srclen: the length of the string, -1 means strlen(src) |
110 | * @dst: the binary (u8[4] array) representation of the IPv4 address |
111 | * @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter |
112 | * @end: A pointer to the end of the parsed string will be placed here |
113 | * |
114 | * Return one on success, return zero when any error occurs |
115 | * and @end will point to the end of the parsed string. |
116 | * |
117 | */ |
118 | int in4_pton(const char *src, int srclen, |
119 | u8 *dst, |
120 | int delim, const char **end) |
121 | { |
122 | const char *s; |
123 | u8 *d; |
124 | u8 dbuf[4]; |
125 | int ret = 0; |
126 | int i; |
127 | int w = 0; |
128 | |
129 | if (srclen < 0) |
130 | srclen = strlen(src); |
131 | s = src; |
132 | d = dbuf; |
133 | i = 0; |
134 | while (1) { |
135 | int c; |
136 | c = xdigit2bin(c: srclen > 0 ? *s : '\0', delim); |
137 | if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) { |
138 | goto out; |
139 | } |
140 | if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) { |
141 | if (w == 0) |
142 | goto out; |
143 | *d++ = w & 0xff; |
144 | w = 0; |
145 | i++; |
146 | if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) { |
147 | if (i != 4) |
148 | goto out; |
149 | break; |
150 | } |
151 | goto cont; |
152 | } |
153 | w = (w * 10) + c; |
154 | if ((w & 0xffff) > 255) { |
155 | goto out; |
156 | } |
157 | cont: |
158 | if (i >= 4) |
159 | goto out; |
160 | s++; |
161 | srclen--; |
162 | } |
163 | ret = 1; |
164 | memcpy(dst, dbuf, sizeof(dbuf)); |
165 | out: |
166 | if (end) |
167 | *end = s; |
168 | return ret; |
169 | } |
170 | EXPORT_SYMBOL(in4_pton); |
171 | |
172 | /** |
173 | * in6_pton - convert an IPv6 address from literal to binary representation |
174 | * @src: the start of the IPv6 address string |
175 | * @srclen: the length of the string, -1 means strlen(src) |
176 | * @dst: the binary (u8[16] array) representation of the IPv6 address |
177 | * @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter |
178 | * @end: A pointer to the end of the parsed string will be placed here |
179 | * |
180 | * Return one on success, return zero when any error occurs |
181 | * and @end will point to the end of the parsed string. |
182 | * |
183 | */ |
184 | int in6_pton(const char *src, int srclen, |
185 | u8 *dst, |
186 | int delim, const char **end) |
187 | { |
188 | const char *s, *tok = NULL; |
189 | u8 *d, *dc = NULL; |
190 | u8 dbuf[16]; |
191 | int ret = 0; |
192 | int i; |
193 | int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL; |
194 | int w = 0; |
195 | |
196 | memset(dbuf, 0, sizeof(dbuf)); |
197 | |
198 | s = src; |
199 | d = dbuf; |
200 | if (srclen < 0) |
201 | srclen = strlen(src); |
202 | |
203 | while (1) { |
204 | int c; |
205 | |
206 | c = xdigit2bin(c: srclen > 0 ? *s : '\0', delim); |
207 | if (!(c & state)) |
208 | goto out; |
209 | if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) { |
210 | /* process one 16-bit word */ |
211 | if (!(state & IN6PTON_NULL)) { |
212 | *d++ = (w >> 8) & 0xff; |
213 | *d++ = w & 0xff; |
214 | } |
215 | w = 0; |
216 | if (c & IN6PTON_DELIM) { |
217 | /* We've processed last word */ |
218 | break; |
219 | } |
220 | /* |
221 | * COLON_1 => XDIGIT |
222 | * COLON_2 => XDIGIT|DELIM |
223 | * COLON_1_2 => COLON_2 |
224 | */ |
225 | switch (state & IN6PTON_COLON_MASK) { |
226 | case IN6PTON_COLON_2: |
227 | dc = d; |
228 | state = IN6PTON_XDIGIT | IN6PTON_DELIM; |
229 | if (dc - dbuf >= sizeof(dbuf)) |
230 | state |= IN6PTON_NULL; |
231 | break; |
232 | case IN6PTON_COLON_1|IN6PTON_COLON_1_2: |
233 | state = IN6PTON_XDIGIT | IN6PTON_COLON_2; |
234 | break; |
235 | case IN6PTON_COLON_1: |
236 | state = IN6PTON_XDIGIT; |
237 | break; |
238 | case IN6PTON_COLON_1_2: |
239 | state = IN6PTON_COLON_2; |
240 | break; |
241 | default: |
242 | state = 0; |
243 | } |
244 | tok = s + 1; |
245 | goto cont; |
246 | } |
247 | |
248 | if (c & IN6PTON_DOT) { |
249 | ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s); |
250 | if (ret > 0) { |
251 | d += 4; |
252 | break; |
253 | } |
254 | goto out; |
255 | } |
256 | |
257 | w = (w << 4) | (0xff & c); |
258 | state = IN6PTON_COLON_1 | IN6PTON_DELIM; |
259 | if (!(w & 0xf000)) { |
260 | state |= IN6PTON_XDIGIT; |
261 | } |
262 | if (!dc && d + 2 < dbuf + sizeof(dbuf)) { |
263 | state |= IN6PTON_COLON_1_2; |
264 | state &= ~IN6PTON_DELIM; |
265 | } |
266 | if (d + 2 >= dbuf + sizeof(dbuf)) { |
267 | state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2); |
268 | } |
269 | cont: |
270 | if ((dc && d + 4 < dbuf + sizeof(dbuf)) || |
271 | d + 4 == dbuf + sizeof(dbuf)) { |
272 | state |= IN6PTON_DOT; |
273 | } |
274 | if (d >= dbuf + sizeof(dbuf)) { |
275 | state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK); |
276 | } |
277 | s++; |
278 | srclen--; |
279 | } |
280 | |
281 | i = 15; d--; |
282 | |
283 | if (dc) { |
284 | while (d >= dc) |
285 | dst[i--] = *d--; |
286 | while (i >= dc - dbuf) |
287 | dst[i--] = 0; |
288 | while (i >= 0) |
289 | dst[i--] = *d--; |
290 | } else |
291 | memcpy(dst, dbuf, sizeof(dbuf)); |
292 | |
293 | ret = 1; |
294 | out: |
295 | if (end) |
296 | *end = s; |
297 | return ret; |
298 | } |
299 | EXPORT_SYMBOL(in6_pton); |
300 | |
301 | static int inet4_pton(const char *src, u16 port_num, |
302 | struct sockaddr_storage *addr) |
303 | { |
304 | struct sockaddr_in *addr4 = (struct sockaddr_in *)addr; |
305 | size_t srclen = strlen(src); |
306 | |
307 | if (srclen > INET_ADDRSTRLEN) |
308 | return -EINVAL; |
309 | |
310 | if (in4_pton(src, srclen, (u8 *)&addr4->sin_addr.s_addr, |
311 | '\n', NULL) == 0) |
312 | return -EINVAL; |
313 | |
314 | addr4->sin_family = AF_INET; |
315 | addr4->sin_port = htons(port_num); |
316 | |
317 | return 0; |
318 | } |
319 | |
320 | static int inet6_pton(struct net *net, const char *src, u16 port_num, |
321 | struct sockaddr_storage *addr) |
322 | { |
323 | struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr; |
324 | const char *scope_delim; |
325 | size_t srclen = strlen(src); |
326 | |
327 | if (srclen > INET6_ADDRSTRLEN) |
328 | return -EINVAL; |
329 | |
330 | if (in6_pton(src, srclen, (u8 *)&addr6->sin6_addr.s6_addr, |
331 | '%', &scope_delim) == 0) |
332 | return -EINVAL; |
333 | |
334 | if (ipv6_addr_type(addr: &addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL && |
335 | src + srclen != scope_delim && *scope_delim == '%') { |
336 | struct net_device *dev; |
337 | char scope_id[16]; |
338 | size_t scope_len = min_t(size_t, sizeof(scope_id) - 1, |
339 | src + srclen - scope_delim - 1); |
340 | |
341 | memcpy(scope_id, scope_delim + 1, scope_len); |
342 | scope_id[scope_len] = '\0'; |
343 | |
344 | dev = dev_get_by_name(net, name: scope_id); |
345 | if (dev) { |
346 | addr6->sin6_scope_id = dev->ifindex; |
347 | dev_put(dev); |
348 | } else if (kstrtouint(s: scope_id, base: 0, res: &addr6->sin6_scope_id)) { |
349 | return -EINVAL; |
350 | } |
351 | } |
352 | |
353 | addr6->sin6_family = AF_INET6; |
354 | addr6->sin6_port = htons(port_num); |
355 | |
356 | return 0; |
357 | } |
358 | |
359 | /** |
360 | * inet_pton_with_scope - convert an IPv4/IPv6 and port to socket address |
361 | * @net: net namespace (used for scope handling) |
362 | * @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either |
363 | * @src: the start of the address string |
364 | * @port: the start of the port string (or NULL for none) |
365 | * @addr: output socket address |
366 | * |
367 | * Return zero on success, return errno when any error occurs. |
368 | */ |
369 | int inet_pton_with_scope(struct net *net, __kernel_sa_family_t af, |
370 | const char *src, const char *port, struct sockaddr_storage *addr) |
371 | { |
372 | u16 port_num; |
373 | int ret = -EINVAL; |
374 | |
375 | if (port) { |
376 | if (kstrtou16(s: port, base: 0, res: &port_num)) |
377 | return -EINVAL; |
378 | } else { |
379 | port_num = 0; |
380 | } |
381 | |
382 | switch (af) { |
383 | case AF_INET: |
384 | ret = inet4_pton(src, port_num, addr); |
385 | break; |
386 | case AF_INET6: |
387 | ret = inet6_pton(net, src, port_num, addr); |
388 | break; |
389 | case AF_UNSPEC: |
390 | ret = inet4_pton(src, port_num, addr); |
391 | if (ret) |
392 | ret = inet6_pton(net, src, port_num, addr); |
393 | break; |
394 | default: |
395 | pr_err("unexpected address family %d\n" , af); |
396 | } |
397 | |
398 | return ret; |
399 | } |
400 | EXPORT_SYMBOL(inet_pton_with_scope); |
401 | |
402 | bool inet_addr_is_any(struct sockaddr *addr) |
403 | { |
404 | if (addr->sa_family == AF_INET6) { |
405 | struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr; |
406 | const struct sockaddr_in6 in6_any = |
407 | { .sin6_addr = IN6ADDR_ANY_INIT }; |
408 | |
409 | if (!memcmp(p: in6->sin6_addr.s6_addr, |
410 | q: in6_any.sin6_addr.s6_addr, size: 16)) |
411 | return true; |
412 | } else if (addr->sa_family == AF_INET) { |
413 | struct sockaddr_in *in = (struct sockaddr_in *)addr; |
414 | |
415 | if (in->sin_addr.s_addr == htonl(INADDR_ANY)) |
416 | return true; |
417 | } else { |
418 | pr_warn("unexpected address family %u\n" , addr->sa_family); |
419 | } |
420 | |
421 | return false; |
422 | } |
423 | EXPORT_SYMBOL(inet_addr_is_any); |
424 | |
425 | void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, |
426 | __be32 from, __be32 to, bool pseudohdr) |
427 | { |
428 | if (skb->ip_summed != CHECKSUM_PARTIAL) { |
429 | csum_replace4(sum, from, to); |
430 | if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr) |
431 | skb->csum = ~csum_add(csum: csum_sub(csum: ~(skb->csum), |
432 | addend: (__force __wsum)from), |
433 | addend: (__force __wsum)to); |
434 | } else if (pseudohdr) |
435 | *sum = ~csum_fold(sum: csum_add(csum: csum_sub(csum: csum_unfold(n: *sum), |
436 | addend: (__force __wsum)from), |
437 | addend: (__force __wsum)to)); |
438 | } |
439 | EXPORT_SYMBOL(inet_proto_csum_replace4); |
440 | |
441 | /** |
442 | * inet_proto_csum_replace16 - update layer 4 header checksum field |
443 | * @sum: Layer 4 header checksum field |
444 | * @skb: sk_buff for the packet |
445 | * @from: old IPv6 address |
446 | * @to: new IPv6 address |
447 | * @pseudohdr: True if layer 4 header checksum includes pseudoheader |
448 | * |
449 | * Update layer 4 header as per the update in IPv6 src/dst address. |
450 | * |
451 | * There is no need to update skb->csum in this function, because update in two |
452 | * fields a.) IPv6 src/dst address and b.) L4 header checksum cancels each other |
453 | * for skb->csum calculation. Whereas inet_proto_csum_replace4 function needs to |
454 | * update skb->csum, because update in 3 fields a.) IPv4 src/dst address, |
455 | * b.) IPv4 Header checksum and c.) L4 header checksum results in same diff as |
456 | * L4 Header checksum for skb->csum calculation. |
457 | */ |
458 | void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, |
459 | const __be32 *from, const __be32 *to, |
460 | bool pseudohdr) |
461 | { |
462 | __be32 diff[] = { |
463 | ~from[0], ~from[1], ~from[2], ~from[3], |
464 | to[0], to[1], to[2], to[3], |
465 | }; |
466 | if (skb->ip_summed != CHECKSUM_PARTIAL) { |
467 | *sum = csum_fold(sum: csum_partial(buff: diff, len: sizeof(diff), |
468 | sum: ~csum_unfold(n: *sum))); |
469 | } else if (pseudohdr) |
470 | *sum = ~csum_fold(sum: csum_partial(buff: diff, len: sizeof(diff), |
471 | sum: csum_unfold(n: *sum))); |
472 | } |
473 | EXPORT_SYMBOL(inet_proto_csum_replace16); |
474 | |
475 | void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb, |
476 | __wsum diff, bool pseudohdr) |
477 | { |
478 | if (skb->ip_summed != CHECKSUM_PARTIAL) { |
479 | csum_replace_by_diff(sum, diff); |
480 | if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr) |
481 | skb->csum = ~csum_sub(csum: diff, addend: skb->csum); |
482 | } else if (pseudohdr) { |
483 | *sum = ~csum_fold(sum: csum_add(csum: diff, addend: csum_unfold(n: *sum))); |
484 | } |
485 | } |
486 | EXPORT_SYMBOL(inet_proto_csum_replace_by_diff); |
487 | |