xref: /illumos-gate/usr/src/uts/common/inet/ip/inet_ntop.c (revision b1e2e3fb17324e9ddf43db264a0c64da7756d9e6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  * Copyright 2017 Nexenta Systems, Inc.
27  */
28 
29 #include <sys/types.h>
30 #include <sys/cmn_err.h>
31 #include <sys/systm.h>
32 #include <sys/socket.h>
33 #include <sys/sunddi.h>
34 #include <netinet/in.h>
35 #include <inet/led.h>
36 
37 /*
38  * v6 formats supported
39  * General format xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx
40  * The short hand notation :: is used for COMPAT addr
41  * Other forms : fe80::xxxx:xxxx:xxxx:xxxx
42  */
43 static void
44 convert2ascii(char *buf, const in6_addr_t *addr)
45 {
46 	int		hexdigits;
47 	int		head_zero = 0;
48 	int		tail_zero = 0;
49 	/* tempbuf must be big enough to hold ffff:\0 */
50 	char		tempbuf[6];
51 	char		*ptr;
52 	uint16_t	*addr_component;
53 	size_t		len;
54 	boolean_t	first = B_FALSE;
55 	boolean_t	med_zero = B_FALSE;
56 	boolean_t	end_zero = B_FALSE;
57 
58 	addr_component = (uint16_t *)addr;
59 	ptr = buf;
60 
61 	/* First count if trailing zeroes higher in number */
62 	for (hexdigits = 0; hexdigits < 8; hexdigits++) {
63 		if (*addr_component == 0) {
64 			if (hexdigits < 4)
65 				head_zero++;
66 			else
67 				tail_zero++;
68 		}
69 		addr_component++;
70 	}
71 	addr_component = (uint16_t *)addr;
72 	if (tail_zero > head_zero && (head_zero + tail_zero) != 7)
73 		end_zero = B_TRUE;
74 
75 	for (hexdigits = 0; hexdigits < 8; hexdigits++) {
76 
77 		/* if entry is a 0 */
78 
79 		if (*addr_component == 0) {
80 			if (!first && *(addr_component + 1) == 0) {
81 				if (end_zero && (hexdigits < 4)) {
82 					*ptr++ = '0';
83 					*ptr++ = ':';
84 				} else {
85 					/*
86 					 * address starts with 0s ..
87 					 * stick in leading ':' of pair
88 					 */
89 					if (hexdigits == 0)
90 						*ptr++ = ':';
91 					/* add another */
92 					*ptr++ = ':';
93 					first = B_TRUE;
94 					med_zero = B_TRUE;
95 				}
96 			} else if (first && med_zero) {
97 				if (hexdigits == 7)
98 					*ptr++ = ':';
99 				addr_component++;
100 				continue;
101 			} else {
102 				*ptr++ = '0';
103 				*ptr++ = ':';
104 			}
105 			addr_component++;
106 			continue;
107 		}
108 		if (med_zero)
109 			med_zero = B_FALSE;
110 
111 		tempbuf[0] = '\0';
112 		(void) sprintf(tempbuf, "%x:", ntohs(*addr_component) & 0xffff);
113 		len = strlen(tempbuf);
114 		bcopy(tempbuf, ptr, len);
115 		ptr = ptr + len;
116 		addr_component++;
117 	}
118 	*--ptr = '\0';
119 }
120 
121 /*
122  * search for char c, terminate on trailing white space
123  */
124 static char *
125 strchr_w(const char *sp, int c)
126 {
127 	/* skip leading white space */
128 	while (*sp && (*sp == ' ' || *sp == '\t')) {
129 		sp++;
130 	}
131 
132 	do {
133 		if (*sp == (char)c)
134 			return ((char *)sp);
135 		if (*sp == ' ' || *sp == '\t')
136 			return (NULL);
137 	} while (*sp++);
138 	return (NULL);
139 }
140 
141 static int
142 str2inet_addr(char *cp, ipaddr_t *addrp)
143 {
144 	char *end;
145 	long byte;
146 	int i;
147 	ipaddr_t addr = 0;
148 
149 	for (i = 0; i < 4; i++) {
150 		if (ddi_strtol(cp, &end, 10, &byte) != 0 || byte < 0 ||
151 		    byte > 255) {
152 			return (0);
153 		}
154 		addr = (addr << 8) | (uint8_t)byte;
155 		if (i < 3) {
156 			if (*end != '.') {
157 				return (0);
158 			} else {
159 				cp = end + 1;
160 			}
161 		} else {
162 			cp = end;
163 		}
164 	}
165 	*addrp = addr;
166 	return (1);
167 }
168 
169 /*
170  * inet_ntop: Convert an IPv4 or IPv6 address in binary form into
171  * printable form, and return a pointer to that string.  Caller should
172  * provide a buffer of correct length to store string into.
173  * Note: this routine is kernel version of inet_ntop.  It has similar
174  * format as inet_ntop() defined in RFC 2553, but it does not do
175  * error handling operations exactly as RFC 2553 defines.
176  */
177 static char *
178 __inet_ntop(int af, const void *addr, char *buf, int addrlen, int compat)
179 {
180 	static char	*badaf = "<badfamily>";
181 	in6_addr_t	*v6addr;
182 	uchar_t		*v4addr;
183 	char		*caddr;
184 
185 	VERIFY(addr != NULL);
186 	VERIFY(OK_32PTR(addr));
187 	VERIFY(buf != NULL);
188 
189 	buf[0] = '\0';
190 
191 #define	UC(b)	(((int)b) & 0xff)
192 	switch (af) {
193 	case AF_INET:
194 		ASSERT(addrlen >= INET_ADDRSTRLEN);
195 		v4addr = (uchar_t *)addr;
196 		(void) sprintf(buf,
197 		    (compat) ? "%03d.%03d.%03d.%03d" : "%d.%d.%d.%d",
198 		    UC(v4addr[0]), UC(v4addr[1]), UC(v4addr[2]), UC(v4addr[3]));
199 		return (buf);
200 	case AF_INET6:
201 		ASSERT(addrlen >= INET6_ADDRSTRLEN);
202 		v6addr = (in6_addr_t *)addr;
203 		if (IN6_IS_ADDR_V4MAPPED(v6addr)) {
204 			caddr = (char *)addr;
205 			(void) sprintf(buf, "::ffff:%d.%d.%d.%d",
206 			    UC(caddr[12]), UC(caddr[13]),
207 			    UC(caddr[14]), UC(caddr[15]));
208 		} else if (IN6_IS_ADDR_V4COMPAT(v6addr)) {
209 			caddr = (char *)addr;
210 			(void) sprintf(buf, "::%d.%d.%d.%d",
211 			    UC(caddr[12]), UC(caddr[13]), UC(caddr[14]),
212 			    UC(caddr[15]));
213 		} else if (IN6_IS_ADDR_UNSPECIFIED(v6addr)) {
214 			(void) sprintf(buf, "::");
215 		} else {
216 			convert2ascii(buf, v6addr);
217 		}
218 		return (buf);
219 
220 	default:
221 		return (badaf);
222 	}
223 #undef UC
224 }
225 
226 /*
227  * Provide fixed inet_ntop() implementation.
228  */
229 char *
230 _inet_ntop(int af, const void *addr, char *buf, int addrlen)
231 {
232 	return (__inet_ntop(af, addr, buf, addrlen, 0));
233 }
234 
235 /*
236  * Provide old inet_ntop() implementation by default for binary
237  * compatibility.
238  */
239 char *
240 inet_ntop(int af, const void *addr, char *buf, int addrlen)
241 {
242 	static char	local_buf[INET6_ADDRSTRLEN];
243 	static char	*badaddr = "<badaddr>";
244 
245 	if (addr == NULL || !(OK_32PTR(addr)))
246 		return (badaddr);
247 
248 	if (buf == NULL) {
249 		buf = local_buf;
250 		addrlen = sizeof (local_buf);
251 	}
252 
253 	return (__inet_ntop(af, addr, buf, addrlen, 1));
254 }
255 
256 /*
257  * inet_pton: This function takes string format IPv4 or IPv6 address and
258  * converts it to binary form. The format of this function corresponds to
259  * inet_pton() in the socket library.
260  *
261  * Return values:
262  *  0 invalid IPv4 or IPv6 address
263  *  1 successful conversion
264  * -1 af is not AF_INET or AF_INET6
265  */
266 static int
267 __inet_pton(int af, char *inp, void *outp, int compat)
268 {
269 	int i;
270 	long byte;
271 	char *end;
272 
273 	switch (af) {
274 	case AF_INET:
275 		if (str2inet_addr(inp, (ipaddr_t *)outp) != 0) {
276 			if (!compat)
277 				*(uint32_t *)outp = htonl(*(uint32_t *)outp);
278 			return (1);
279 		} else {
280 			return (0);
281 		}
282 	case AF_INET6: {
283 		union v6buf_u {
284 			uint16_t v6words_u[8];
285 			in6_addr_t v6addr_u;
286 		} v6buf, *v6outp;
287 		uint16_t	*dbl_col = NULL;
288 		char lastbyte = '\0';
289 
290 		v6outp = (union v6buf_u *)outp;
291 
292 		if (strchr_w(inp, '.') != NULL) {
293 			int ret = 0;
294 
295 			/* v4 mapped or v4 compatable */
296 			if (strncmp(inp, "::ffff:", 7) == 0) {
297 				ipaddr_t ipv4_all_zeroes = 0;
298 				/* mapped - first init prefix and then fill */
299 				IN6_IPADDR_TO_V4MAPPED(ipv4_all_zeroes,
300 				    &v6outp->v6addr_u);
301 				ret = str2inet_addr(inp + 7,
302 				    &(v6outp->v6addr_u.s6_addr32[3]));
303 			} else if (strncmp(inp, "::", 2) == 0) {
304 				/* v4 compatable - prefix all zeroes */
305 				bzero(&v6outp->v6addr_u, sizeof (in6_addr_t));
306 				ret = str2inet_addr(inp + 2,
307 				    &(v6outp->v6addr_u.s6_addr32[3]));
308 			}
309 			if (ret > 0 && !compat) {
310 				v6outp->v6addr_u.s6_addr32[3] =
311 				    htonl(v6outp->v6addr_u.s6_addr32[3]);
312 			}
313 			return (ret);
314 		}
315 		for (i = 0; i < 8; i++) {
316 			int error;
317 			/*
318 			 * if ddi_strtol() fails it could be because
319 			 * the string is "::".  That is valid and
320 			 * checked for below so just set the value to
321 			 * 0 and continue.
322 			 */
323 			if ((error = ddi_strtol(inp, &end, 16, &byte)) != 0) {
324 				if (error == ERANGE)
325 					return (0);
326 				byte = 0;
327 			}
328 			if (byte < 0 || byte > 0x0ffff) {
329 				return (0);
330 			}
331 			if (compat) {
332 				v6buf.v6words_u[i] = (uint16_t)byte;
333 			} else {
334 				v6buf.v6words_u[i] = htons((uint16_t)byte);
335 			}
336 			if (*end == '\0' || i == 7) {
337 				inp = end;
338 				break;
339 			}
340 			if (inp == end) {	/* not a number must be */
341 				if (*inp == ':' &&
342 				    ((i == 0 && *(inp + 1) == ':') ||
343 				    lastbyte == ':')) {
344 					if (dbl_col) {
345 						return (0);
346 					}
347 					if (byte != 0)
348 						i++;
349 					dbl_col = &v6buf.v6words_u[i];
350 					if (i == 0)
351 						inp++;
352 				} else if (*inp == '\0' || *inp == ' ' ||
353 				    *inp == '\t') {
354 					break;
355 				} else {
356 					return (0);
357 				}
358 			} else {
359 				inp = end;
360 			}
361 			if (*inp != ':') {
362 				return (0);
363 			}
364 			inp++;
365 			if (*inp == '\0' || *inp == ' ' || *inp == '\t') {
366 				break;
367 			}
368 			lastbyte = *inp;
369 		}
370 		if (*inp != '\0' && *inp != ' ' && *inp != '\t') {
371 			return (0);
372 		}
373 		/*
374 		 * v6words now contains the bytes we could translate
375 		 * dbl_col points to the word (should be 0) where
376 		 * a double colon was found
377 		 */
378 		if (i == 7) {
379 			v6outp->v6addr_u = v6buf.v6addr_u;
380 		} else {
381 			int rem;
382 			int word;
383 			int next;
384 			if (dbl_col == NULL) {
385 				return (0);
386 			}
387 			bzero(&v6outp->v6addr_u, sizeof (in6_addr_t));
388 			rem = dbl_col - &v6buf.v6words_u[0];
389 			for (next = 0; next < rem; next++) {
390 				v6outp->v6words_u[next] = v6buf.v6words_u[next];
391 			}
392 			next++;	/* skip dbl_col 0 */
393 			rem = i - rem;
394 			word = 8 - rem;
395 			while (rem > 0) {
396 				v6outp->v6words_u[word] = v6buf.v6words_u[next];
397 				word++;
398 				rem--;
399 				next++;
400 			}
401 		}
402 		return (1);	/* Success */
403 	}
404 	}	/* switch */
405 	return (-1);	/* return -1 for default case */
406 }
407 
408 /*
409  * Provide fixed inet_pton() implementation.
410  */
411 int
412 _inet_pton(int af, char *inp, void *outp)
413 {
414 	return (__inet_pton(af, inp, outp, 0));
415 }
416 
417 /*
418  * Provide broken inet_pton() implementation by default for binary
419  * compatibility.
420  */
421 int
422 inet_pton(int af, char *inp, void *outp)
423 {
424 	return (__inet_pton(af, inp, outp, 1));
425 }
426