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diff --git a/src/lib/libc/net/inet6_option_space.3 b/src/lib/libc/net/inet6_option_space.3 index 4b156636f7..e69de29bb2 100644 --- a/src/lib/libc/net/inet6_option_space.3 +++ b/src/lib/libc/net/inet6_option_space.3 | |||
@@ -1,442 +0,0 @@ | |||
1 | .\" $OpenBSD: inet6_option_space.3,v 1.24 2014/01/21 03:15:45 schwarze Exp $ | ||
2 | .\" $KAME: inet6_option_space.3,v 1.11 2005/01/05 03:00:44 itojun Exp $ | ||
3 | .\" | ||
4 | .\" Copyright (C) 2004 WIDE Project. | ||
5 | .\" All rights reserved. | ||
6 | .\" | ||
7 | .\" Redistribution and use in source and binary forms, with or without | ||
8 | .\" modification, are permitted provided that the following conditions | ||
9 | .\" are met: | ||
10 | .\" 1. Redistributions of source code must retain the above copyright | ||
11 | .\" notice, this list of conditions and the following disclaimer. | ||
12 | .\" 2. Redistributions in binary form must reproduce the above copyright | ||
13 | .\" notice, this list of conditions and the following disclaimer in the | ||
14 | .\" documentation and/or other materials provided with the distribution. | ||
15 | .\" 3. Neither the name of the project nor the names of its contributors | ||
16 | .\" may be used to endorse or promote products derived from this software | ||
17 | .\" without specific prior written permission. | ||
18 | .\" | ||
19 | .\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND | ||
20 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
21 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
22 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE | ||
23 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
24 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
25 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
26 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
27 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
28 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
29 | .\" SUCH DAMAGE. | ||
30 | .\" | ||
31 | .Dd $Mdocdate: January 21 2014 $ | ||
32 | .Dt INET6_OPTION_SPACE 3 | ||
33 | .Os | ||
34 | .\" | ||
35 | .Sh NAME | ||
36 | .Nm inet6_option_space , | ||
37 | .Nm inet6_option_init , | ||
38 | .Nm inet6_option_append , | ||
39 | .Nm inet6_option_alloc , | ||
40 | .Nm inet6_option_next , | ||
41 | .Nm inet6_option_find | ||
42 | .Nd IPv6 Hop-by-Hop and Destination Option Manipulation | ||
43 | .\" | ||
44 | .Sh SYNOPSIS | ||
45 | .In sys/types.h | ||
46 | .In netinet/in.h | ||
47 | .Ft "int" | ||
48 | .Fn inet6_option_space "int nbytes" | ||
49 | .Ft "int" | ||
50 | .Fn inet6_option_init "void *bp" "struct cmsghdr **cmsgp" "int type" | ||
51 | .Ft "int" | ||
52 | .Fn inet6_option_append "struct cmsghdr *cmsg" "const u_int8_t *typep" "int multx" "int plusy" | ||
53 | .Ft "u_int8_t *" | ||
54 | .Fn inet6_option_alloc "struct cmsghdr *cmsg" "int datalen" "int multx" "int plusy" | ||
55 | .Ft "int" | ||
56 | .Fn inet6_option_next "const struct cmsghdr *cmsg" "u_int8_t **tptrp" | ||
57 | .Ft "int" | ||
58 | .Fn inet6_option_find "const struct cmsghdr *cmsg" "u_int8_t **tptrp" "int type" | ||
59 | .\" | ||
60 | .Sh DESCRIPTION | ||
61 | .\" | ||
62 | Note: | ||
63 | RFC 2292 has been superseded by RFC 3542. | ||
64 | The use of functions described in this page is deprecated. | ||
65 | See | ||
66 | .Xr inet6_opt_init 3 . | ||
67 | .Pp | ||
68 | Manipulating and parsing IPv6's Hop-by-Hop and Destination options is | ||
69 | complicated by the need to properly align and pad data as well as the | ||
70 | need to manipulate ancillary information that is not part of the data | ||
71 | stream. | ||
72 | RFC 2292 defines a set of functions, which are implemented as | ||
73 | part of the Kame libraries, to help developers create, change, | ||
74 | and parse Hop-by-Hop and Destination options. | ||
75 | All of the prototypes | ||
76 | for the option functions are defined in the | ||
77 | .In netinet/in.h | ||
78 | header file. | ||
79 | .\" | ||
80 | .Ss inet6_option_space | ||
81 | In order to determine the amount of space necessary to hold any option | ||
82 | the | ||
83 | .Fn inet6_option_space | ||
84 | function is called. | ||
85 | It returns the number of bytes required to hold | ||
86 | an option when it is stored as ancillary data, including the | ||
87 | .Li cmsghdr | ||
88 | structure at the beginning, and any necessary padding at the end. | ||
89 | The | ||
90 | .Fa nbytes | ||
91 | argument indicates the size of the structure defining the option, | ||
92 | and must include any pad bytes at the beginning (the value | ||
93 | .Li y | ||
94 | in the alignment term | ||
95 | .Dq Li "xn + y" ) , | ||
96 | the type byte, the length byte, and the option data. | ||
97 | .Pp | ||
98 | Note: If multiple options are stored in a single ancillary data | ||
99 | object, which is the recommended technique, the | ||
100 | .Fn inet6_option_space | ||
101 | function overestimates the amount of space required by the size of | ||
102 | .Li N-1 | ||
103 | .Li cmsghdr | ||
104 | structures, where | ||
105 | .Li N | ||
106 | is the number of options to be stored in the object. | ||
107 | Usually this has | ||
108 | no impact because it is assumed that most Hop-by-Hop and Destination | ||
109 | option headers carry only one option as indicated in appendix B of RFC 2460. | ||
110 | .\" | ||
111 | .Ss inet6_option_init | ||
112 | The | ||
113 | .Fn inet6_option_init | ||
114 | function is called to initialize any ancillary data object that will contain | ||
115 | a Hop-by-Hop or Destination option. | ||
116 | It returns | ||
117 | .Li 0 | ||
118 | on success and | ||
119 | .Li \-1 | ||
120 | when an error occurs. | ||
121 | .Pp | ||
122 | The | ||
123 | .Fa bp | ||
124 | argument points to a previously allocated area of memory which must be | ||
125 | large enough to contain all the arguments that the application intends | ||
126 | to add later via the | ||
127 | .Fn inet6_option_append | ||
128 | and | ||
129 | .Fn inet6_option_alloc | ||
130 | routines. | ||
131 | .Pp | ||
132 | The | ||
133 | .Fa cmsgp | ||
134 | argument is a pointer to a pointer to a | ||
135 | .Li cmsghdr | ||
136 | structure. | ||
137 | The | ||
138 | .Fa *cmsgp | ||
139 | argument | ||
140 | points to a | ||
141 | .Li cmsghdr | ||
142 | structure which is constructed by this function and stored in the | ||
143 | area of memory pointed to by | ||
144 | .Fa bp . | ||
145 | .Pp | ||
146 | The | ||
147 | .Fa type | ||
148 | is either | ||
149 | .Dv IPV6_HOPOPTS | ||
150 | or | ||
151 | .Dv IPV6_DSTOPTS | ||
152 | and is stored in the | ||
153 | .Li cmsg_type | ||
154 | member of the | ||
155 | .Li cmsghdr | ||
156 | structure mentioned above. | ||
157 | .\" | ||
158 | .Ss inet6_option_append | ||
159 | This function appends a Hop-by-Hop option or a Destination option into | ||
160 | an ancillary data object previously initialized by a call to | ||
161 | .Fn inet6_option_init . | ||
162 | The | ||
163 | .Fn inet6_option_append | ||
164 | function returns | ||
165 | .Li 0 | ||
166 | if it succeeds or | ||
167 | .Li \-1 | ||
168 | when an error occurs. | ||
169 | .Pp | ||
170 | The | ||
171 | .Fa cmsg | ||
172 | argument is a pointer to the | ||
173 | .Li cmsghdr | ||
174 | structure that was initialized by a call to | ||
175 | .Fn inet6_option_init . | ||
176 | .Pp | ||
177 | The | ||
178 | .Fa typep | ||
179 | argument is a pointer to the 8-bit option type. | ||
180 | All options are | ||
181 | encoded as type-length-value tuples and it is assumed that | ||
182 | the | ||
183 | .Fa typep | ||
184 | field is immediately followed by the 8-bit option data length field, | ||
185 | which is then followed by the option data. | ||
186 | .Pp | ||
187 | The option types of | ||
188 | .Li 0 | ||
189 | and | ||
190 | .Li 1 | ||
191 | are reserved for the | ||
192 | .Li Pad1 | ||
193 | and | ||
194 | .Li PadN | ||
195 | options respectively. | ||
196 | All other values from | ||
197 | .Li 2 | ||
198 | through | ||
199 | .Li 255 | ||
200 | are available for applications to use. | ||
201 | .Pp | ||
202 | The option data length, since it is stored in 8 bites, must have a | ||
203 | value between | ||
204 | .Li 0 | ||
205 | and | ||
206 | .Li 255 , | ||
207 | inclusive. | ||
208 | .Pp | ||
209 | The | ||
210 | .Fa multx | ||
211 | argument | ||
212 | is the value | ||
213 | .Li x | ||
214 | in the alignment term | ||
215 | .Dq Li xn + y | ||
216 | and indicates the byte alignment necessary for the data. | ||
217 | Alignments may be specified as | ||
218 | .Li 1 , | ||
219 | .Li 2 , | ||
220 | .Li 4 , | ||
221 | or | ||
222 | .Li 8 | ||
223 | bytes, which is no alignment, 16-bit, 32-bit and 64-bit alignments | ||
224 | respectively. | ||
225 | .Pp | ||
226 | The | ||
227 | .Fa plusy | ||
228 | argument | ||
229 | is the value | ||
230 | .Li y | ||
231 | in the alignment term | ||
232 | .Dq Li xn + y | ||
233 | and must have a value between | ||
234 | .Li 0 | ||
235 | and | ||
236 | .Li 7 , | ||
237 | inclusive, indicating the amount of padding that is necessary for an | ||
238 | option. | ||
239 | .\" | ||
240 | .Ss inet6_option_alloc | ||
241 | The | ||
242 | .Fn inet6_option_alloc | ||
243 | function appends a Hop-by-Hop option or a Destination option into an | ||
244 | ancillary data object that has previously been initialized by a call to | ||
245 | .Fn inet6_option_init . | ||
246 | A successful call to the | ||
247 | .Fn inet6_option_alloc | ||
248 | function returns a pointer to the 8-bit option type field, | ||
249 | which is at the beginning of the allocated region. | ||
250 | .Fn inet6_option_alloc | ||
251 | returns | ||
252 | .Dv NULL | ||
253 | when an error has occurred. | ||
254 | .Pp | ||
255 | The difference between the | ||
256 | .Fn inet6_option_alloc | ||
257 | and | ||
258 | .Fn inet6_option_append | ||
259 | functions is that the latter copies the contents of a previously built | ||
260 | option into the ancillary data object while the former returns a | ||
261 | pointer to the place in the data object where the option's TLV must | ||
262 | then be built by the application. | ||
263 | .Pp | ||
264 | The | ||
265 | .Fa cmsg | ||
266 | argument is a pointer to a | ||
267 | .Li cmsghdr | ||
268 | structure that was initialized by | ||
269 | .Fn inet6_option_init . | ||
270 | .Pp | ||
271 | The | ||
272 | .Fa datalen | ||
273 | argument is the value of the option data length byte for this option. | ||
274 | This value is required as an argument to allow the function to | ||
275 | determine if padding must be appended at the end of the option. | ||
276 | (The | ||
277 | .Fn inet6_option_append | ||
278 | function does not need a data length argument | ||
279 | since the option data length must already be stored by the caller.) | ||
280 | .Pp | ||
281 | The | ||
282 | .Fa multx | ||
283 | and | ||
284 | .Fa plusy | ||
285 | arguments | ||
286 | are identical to the arguments of the same name described in the | ||
287 | .Fn inet6_option_init | ||
288 | function above. | ||
289 | .\" | ||
290 | .Ss inet6_option_next | ||
291 | The | ||
292 | .Fn inet6_option_next | ||
293 | function is used to process Hop-by-Hop and Destination options that | ||
294 | are present in an ancillary data object. | ||
295 | When an option remains to | ||
296 | be processed, the return value of the | ||
297 | .Fn inet6_option_next | ||
298 | function is | ||
299 | .Li 0 | ||
300 | and the | ||
301 | .Fa *tptrp | ||
302 | argument points to the 8-bit option type field, which is followed by | ||
303 | the 8-bit option data length, and then the option data. | ||
304 | When no more | ||
305 | options remain to be processed, the return value is | ||
306 | .Li \-1 | ||
307 | and | ||
308 | .Fa *tptrp | ||
309 | is | ||
310 | .Dv NULL . | ||
311 | When an error occurs, the return value is | ||
312 | .Li \-1 , | ||
313 | but the | ||
314 | .Fa *tptrp | ||
315 | argument is not | ||
316 | .Dv NULL . | ||
317 | This set of return values allows a program to easily loop through all | ||
318 | the options in an ancillary data object, checking for the error and | ||
319 | end of stream conditions along the way. | ||
320 | .Pp | ||
321 | When a valid option is returned, the | ||
322 | .Fa cmsg | ||
323 | argument points to a | ||
324 | .Li cmsghdr | ||
325 | where the | ||
326 | .Li cmsg_level | ||
327 | element equals | ||
328 | .Dv IPPROTO_IPV6 | ||
329 | and the | ||
330 | .Li cmsg_type | ||
331 | element is either | ||
332 | .Dv IPV6_HOPOPTS | ||
333 | or | ||
334 | .Dv IPV6_DSTOPTS . | ||
335 | .Pp | ||
336 | The | ||
337 | .Fa tptrp | ||
338 | argument is a pointer to a pointer to an 8-bit byte and | ||
339 | .Fa *tptrp | ||
340 | is used by the function to remember its place in the ancillary data | ||
341 | object each time the function is called. | ||
342 | When the | ||
343 | .Fn inet6_option_next | ||
344 | function is called for the first time on a given ancillary data object, | ||
345 | .Fa *tptrp | ||
346 | must be set to | ||
347 | .Dv NULL . | ||
348 | .Pp | ||
349 | Each time the function returns success, | ||
350 | the | ||
351 | .Fa *tptrp | ||
352 | argument points to the 8-bit option type field for the next option to | ||
353 | be processed. | ||
354 | .\" | ||
355 | .Ss inet6_option_find | ||
356 | The | ||
357 | .Fn inet6_option_find | ||
358 | function allows an application to search for a particular option type | ||
359 | in an ancillary data object. | ||
360 | The | ||
361 | .Fa cmsg | ||
362 | argument is a pointer to a | ||
363 | .Li cmsghdr | ||
364 | structure in which the | ||
365 | .Li cmsg_level | ||
366 | element equals | ||
367 | .Dv IPPROTO_IPV6 | ||
368 | and the | ||
369 | .Li cmsg_type | ||
370 | element is either | ||
371 | .Dv IPV6_HOPOPTS | ||
372 | or | ||
373 | .Dv IPV6_DSTOPTS . | ||
374 | .Pp | ||
375 | The | ||
376 | .Fa tptrp | ||
377 | argument is handled exactly as in the | ||
378 | .Fn inet6_option_next | ||
379 | function described above. | ||
380 | .Pp | ||
381 | The | ||
382 | .Fn inet6_option_find | ||
383 | function starts searching for an option of the specified type | ||
384 | beginning after the value of | ||
385 | .Fa *tptrp . | ||
386 | .\" | ||
387 | .Sh EXAMPLES | ||
388 | RFC 2292 gives comprehensive examples in chapter 6. | ||
389 | .\" | ||
390 | .Sh DIAGNOSTICS | ||
391 | The | ||
392 | .Fn inet6_option_init | ||
393 | and | ||
394 | .Fn inet6_option_append | ||
395 | functions return | ||
396 | .Li 0 | ||
397 | on success or | ||
398 | .Li \-1 | ||
399 | on an error. | ||
400 | .Pp | ||
401 | The | ||
402 | .Fn inet6_option_alloc | ||
403 | function returns | ||
404 | .Dv NULL | ||
405 | on an error. | ||
406 | .Pp | ||
407 | When | ||
408 | .Fn inet6_option_next | ||
409 | or | ||
410 | .Fn inet6_option_find | ||
411 | detect an error they return | ||
412 | .Li \-1 , | ||
413 | setting | ||
414 | .Fa *tptrp | ||
415 | to a non | ||
416 | .Dv NULL | ||
417 | value. | ||
418 | .\" | ||
419 | .Sh SEE ALSO | ||
420 | .Xr inet6 4 , | ||
421 | .Xr ip6 4 | ||
422 | .\" | ||
423 | .Sh STANDARDS | ||
424 | .Rs | ||
425 | .%A W. Stevens | ||
426 | .%A M. Thomas | ||
427 | .%D February 1998 | ||
428 | .%R RFC 2292 | ||
429 | .%T Advanced Sockets API for IPv6 | ||
430 | .Re | ||
431 | .Pp | ||
432 | .Rs | ||
433 | .%A S. Deering | ||
434 | .%A R. Hinden | ||
435 | .%D December 1998 | ||
436 | .%R RFC 2460 | ||
437 | .%T Internet Protocol, Version 6 (IPv6) Specification | ||
438 | .Re | ||
439 | .\" | ||
440 | .Sh HISTORY | ||
441 | This implementation first appeared in the KAME advanced networking kit. | ||
442 | .\" | ||