* sysdeps/i386/tls.h (THREAD_GSCOPE_RESET_FLAG): Use explicit
[glibc.git] / inet / inet6_option.c
blobb34eb22b7dc98629c50b9f3ed90e7c403d29a669
1 /* Copyright (C) 2003, 2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <assert.h>
21 #include <string.h>
22 #include <netinet/in.h>
23 #include <netinet/ip6.h>
24 #include <sys/param.h>
27 static void
28 internal_function
29 add_pad (struct cmsghdr *cmsg, int len)
31 unsigned char *p = CMSG_DATA (cmsg) + cmsg->cmsg_len - CMSG_LEN (0);
33 if (len == 1)
34 /* Special handling for 1, a one-byte solution. */
35 *p++ = IP6OPT_PAD1;
36 else if (len != 0)
38 /* Multibyte padding. */
39 *p++ = IP6OPT_PADN;
40 *p++ = len - 2; /* Discount the two header bytes. */
41 /* The rest is filled with zero. */
42 memset (p, '\0', len - 2);
43 p += len - 2;
46 /* Account for the bytes. */
47 cmsg->cmsg_len += len;
51 static int
52 get_opt_end (const uint8_t **result, const uint8_t *startp,
53 const uint8_t *endp)
55 if (startp >= endp)
56 /* Out of bounds. */
57 return -1;
59 if (*startp == IP6OPT_PAD1)
61 /* Just this one byte. */
62 *result = startp + 1;
63 return 0;
66 /* Now we know there must be at least two bytes. */
67 if (startp + 2 > endp
68 /* Now we can get the length byte. */
69 || startp + startp[1] + 2 > endp)
70 return -1;
72 *result = startp + startp[1] + 2;
74 return 0;
78 static uint8_t *option_alloc (struct cmsghdr *cmsg, int datalen, int multx,
79 int plusy);
82 /* RFC 2292, 6.3.1
84 This function returns the number of bytes required to hold an option
85 when it is stored as ancillary data, including the cmsghdr structure
86 at the beginning, and any padding at the end (to make its size a
87 multiple of 8 bytes). The argument is the size of the structure
88 defining the option, which must include any pad bytes at the
89 beginning (the value y in the alignment term "xn + y"), the type
90 byte, the length byte, and the option data. */
91 int
92 inet6_option_space (nbytes)
93 int nbytes;
95 /* Add room for the extension header. */
96 nbytes += sizeof (struct ip6_ext);
98 return CMSG_SPACE (roundup (nbytes, 8));
100 link_warning (inet6_option_space,
101 "inet6_option_space is obsolete, use the RFC 3542 interfaces")
104 /* RFC 2292, 6.3.2
106 This function is called once per ancillary data object that will
107 contain either Hop-by-Hop or Destination options. It returns 0 on
108 success or -1 on an error. */
110 inet6_option_init (bp, cmsgp, type)
111 void *bp;
112 struct cmsghdr **cmsgp;
113 int type;
115 /* Only Hop-by-Hop or Destination options allowed. */
116 if (type != IPV6_HOPOPTS && type != IPV6_DSTOPTS)
117 return -1;
119 /* BP is a pointer to the previously allocated space. */
120 struct cmsghdr *newp = (struct cmsghdr *) bp;
122 /* Initialize the message header.
124 Length: No data yet, only the cmsghdr struct. */
125 newp->cmsg_len = CMSG_LEN (0);
126 /* Originating protocol: obviously IPv6. */
127 newp->cmsg_level = IPPROTO_IPV6;
128 /* Message type. */
129 newp->cmsg_type = type;
131 /* Pass up the result. */
132 *cmsgp = newp;
134 return 0;
136 link_warning (inet6_option_init,
137 "inet6_option_init is obsolete, use the RFC 3542 interfaces")
140 /* RFC 2292, 6.3.3
142 This function appends a Hop-by-Hop option or a Destination option
143 into an ancillary data object that has been initialized by
144 inet6_option_init(). This function returns 0 if it succeeds or -1 on
145 an error. */
147 inet6_option_append (cmsg, typep, multx, plusy)
148 struct cmsghdr *cmsg;
149 const uint8_t *typep;
150 int multx;
151 int plusy;
153 /* typep is a pointer to the 8-bit option type. It is assumed that this
154 field is immediately followed by the 8-bit option data length field,
155 which is then followed immediately by the option data.
157 The option types IP6OPT_PAD1 and IP6OPT_PADN also must be handled. */
158 int len = typep[0] == IP6OPT_PAD1 ? 1 : typep[1] + 2;
160 /* Get the pointer to the space in the message. */
161 uint8_t *ptr = option_alloc (cmsg, len, multx, plusy);
162 if (ptr == NULL)
163 /* Some problem with the parameters. */
164 return -1;
166 /* Copy the content. */
167 memcpy (ptr, typep, len);
169 return 0;
171 link_warning (inet6_option_append,
172 "inet6_option_append is obsolete, use the RFC 3542 interfaces")
175 /* RFC 2292, 6.3.4
177 This function appends a Hop-by-Hop option or a Destination option
178 into an ancillary data object that has been initialized by
179 inet6_option_init(). This function returns a pointer to the 8-bit
180 option type field that starts the option on success, or NULL on an
181 error. */
182 static uint8_t *
183 option_alloc (struct cmsghdr *cmsg, int datalen, int multx, int plusy)
185 /* The RFC limits the value of the alignment values. */
186 if ((multx != 1 && multx != 2 && multx != 4 && multx != 8)
187 || ! (plusy >= 0 && plusy <= 7))
188 return NULL;
190 /* Current data size. */
191 int dsize = cmsg->cmsg_len - CMSG_LEN (0);
193 /* The first two bytes of the option are for the extended header. */
194 if (__builtin_expect (dsize == 0, 0))
196 cmsg->cmsg_len += sizeof (struct ip6_ext);
197 dsize = sizeof (struct ip6_ext);
200 /* First add padding. */
201 add_pad (cmsg, ((multx - (dsize & (multx - 1))) & (multx - 1)) + plusy);
203 /* Return the pointer to the start of the option space. */
204 uint8_t *result = CMSG_DATA (cmsg) + cmsg->cmsg_len - CMSG_LEN (0);
205 cmsg->cmsg_len += datalen;
207 /* The extended option header length is measured in 8-byte groups.
208 To represent the current length we might have to add padding. */
209 dsize = cmsg->cmsg_len - CMSG_LEN (0);
210 add_pad (cmsg, (8 - (dsize & (8 - 1))) & (8 - 1));
212 /* Record the new length of the option. */
213 assert (((cmsg->cmsg_len - CMSG_LEN (0)) % 8) == 0);
214 int len8b = (cmsg->cmsg_len - CMSG_LEN (0)) / 8 - 1;
215 if (len8b >= 256)
216 /* Too long. */
217 return NULL;
219 ((struct ip6_ext *) CMSG_DATA (cmsg))->ip6e_len = len8b;
221 return result;
225 uint8_t *
226 inet6_option_alloc (cmsg, datalen, multx, plusy)
227 struct cmsghdr *cmsg;
228 int datalen;
229 int multx;
230 int plusy;
232 return option_alloc (cmsg, datalen, multx, plusy);
234 link_warning (inet6_option_alloc,
235 "inet6_option_alloc is obsolete, use the RFC 3542 interfaces")
238 /* RFC 2292, 6.3.5
240 This function processes the next Hop-by-Hop option or Destination
241 option in an ancillary data object. If another option remains to be
242 processed, the return value of the function is 0 and *tptrp points to
243 the 8-bit option type field (which is followed by the 8-bit option
244 data length, followed by the option data). If no more options remain
245 to be processed, the return value is -1 and *tptrp is NULL. If an
246 error occurs, the return value is -1 and *tptrp is not NULL. */
248 inet6_option_next (cmsg, tptrp)
249 const struct cmsghdr *cmsg;
250 uint8_t **tptrp;
252 /* Make sure it is an option of the right type. */
253 if (cmsg->cmsg_level != IPPROTO_IPV6
254 || (cmsg->cmsg_type != IPV6_HOPOPTS && cmsg->cmsg_type != IPV6_DSTOPTS))
255 return -1;
257 /* Pointer to the extension header. We only compute the address, we
258 don't access anything yet. */
259 const struct ip6_ext *ip6e = (const struct ip6_ext *) CMSG_DATA (cmsg);
261 /* Make sure the message is long enough. */
262 if (cmsg->cmsg_len < CMSG_LEN (sizeof (struct ip6_ext))
263 /* Now we can access the extension header. */
264 || cmsg->cmsg_len < CMSG_LEN ((ip6e->ip6e_len + 1) * 8))
265 /* Too small. */
266 return -1;
268 /* Determine the address of the byte past the message. */
269 const uint8_t *endp = CMSG_DATA (cmsg) + (ip6e->ip6e_len + 1) * 8;
271 const uint8_t *result;
272 if (*tptrp == NULL)
273 /* This is the first call, return the first option if there is one. */
274 result = (const uint8_t *) (ip6e + 1);
275 else
277 /* Make sure *TPTRP points to a beginning of a new option in
278 the message. The upper limit is checked in get_opt_end. */
279 if (*tptrp < (const uint8_t *) (ip6e + 1))
280 return -1;
282 /* Get the beginning of the next option. */
283 if (get_opt_end (&result, *tptrp, endp) != 0)
284 return -1;
287 /* We know where the next option starts. */
288 *tptrp = (uint8_t *) result;
290 /* Check the option is fully represented in the message. */
291 return get_opt_end (&result, result, endp);
293 link_warning (inet6_option_next,
294 "inet6_option_next is obsolete, use the RFC 3542 interfaces")
297 /* RFC 2292, 6.3.6
299 This function is similar to the previously described
300 inet6_option_next() function, except this function lets the caller
301 specify the option type to be searched for, instead of always
302 returning the next option in the ancillary data object. cmsg is a
303 pointer to cmsghdr structure of which cmsg_level equals IPPROTO_IPV6
304 and cmsg_type equals either IPV6_HOPOPTS or IPV6_DSTOPTS. */
306 inet6_option_find (cmsg, tptrp, type)
307 const struct cmsghdr *cmsg;
308 uint8_t **tptrp;
309 int type;
311 /* Make sure it is an option of the right type. */
312 if (cmsg->cmsg_level != IPPROTO_IPV6
313 || (cmsg->cmsg_type != IPV6_HOPOPTS && cmsg->cmsg_type != IPV6_DSTOPTS))
314 return -1;
316 /* Pointer to the extension header. We only compute the address, we
317 don't access anything yet. */
318 const struct ip6_ext *ip6e = (const struct ip6_ext *) CMSG_DATA (cmsg);
320 /* Make sure the message is long enough. */
321 if (cmsg->cmsg_len < CMSG_LEN (sizeof (struct ip6_ext))
322 /* Now we can access the extension header. */
323 || cmsg->cmsg_len < CMSG_LEN ((ip6e->ip6e_len + 1) * 8))
324 /* Too small. */
325 return -1;
327 /* Determine the address of the byte past the message. */
328 const uint8_t *endp = CMSG_DATA (cmsg) + (ip6e->ip6e_len + 1) * 8;
330 const uint8_t *next;
331 if (*tptrp == NULL)
332 /* This is the first call, return the first option if there is one. */
333 next = (const uint8_t *) (ip6e + 1);
334 else
336 /* Make sure *TPTRP points to a beginning of a new option in
337 the message. The upper limit is checked in get_opt_end. */
338 if (*tptrp < (const uint8_t *) (ip6e + 1))
339 return -1;
341 /* Get the beginning of the next option. */
342 if (get_opt_end (&next, *tptrp, endp) != 0)
343 return -1;
346 /* Now search for the appropriate typed entry. */
347 const uint8_t *result;
350 result = next;
352 /* Get the end of this entry. */
353 if (get_opt_end (&next, result, endp) != 0)
354 return -1;
356 while (*result != type);
358 /* We know where the next option starts. */
359 *tptrp = (uint8_t *) result;
361 /* Success. */
362 return 0;
364 link_warning (inet6_option_find,
365 "inet6_option_find is obsolete, use the RFC 3542 interfaces")