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git.ipfire.org Git - thirdparty/squid.git/blob - src/HttpHdrRange.cc
2 * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
4 * Squid software is distributed under GPLv2+ license and includes
5 * contributions from numerous individuals and organizations.
6 * Please see the COPYING and CONTRIBUTORS files for details.
9 /* DEBUG: section 64 HTTP Range Header */
12 #include "client_side_request.h"
13 #include "http/Stream.h"
14 #include "HttpHeaderRange.h"
15 #include "HttpHeaderTools.h"
16 #include "HttpReply.h"
21 * Currently only byte ranges are supported
23 * Essentially, there are three types of byte ranges:
25 * 1) first-byte-pos "-" last-byte-pos // range
26 * 2) first-byte-pos "-" // trailer
27 * 3) "-" suffix-length // suffix (last length bytes)
30 * When Range field is parsed, we have no clue about the content
31 * length of the document. Thus, we simply code an "absent" part
32 * using HttpHdrRangeSpec::UnknownPosition constant.
34 * Note: when response length becomes known, we convert any range
35 * spec into type one above. (Canonization process).
39 #define known_spec(s) ((s) > HttpHdrRangeSpec::UnknownPosition)
42 size_t HttpHdrRange::ParsedCount
= 0;
43 int64_t const HttpHdrRangeSpec::UnknownPosition
= -1;
49 HttpHdrRangeSpec::HttpHdrRangeSpec() : offset(UnknownPosition
), length(UnknownPosition
) {}
51 /* parses range-spec and returns new object on success */
53 HttpHdrRangeSpec::Create(const char *field
, int flen
)
55 HttpHdrRangeSpec spec
;
57 if (!spec
.parseInit(field
, flen
))
60 return new HttpHdrRangeSpec(spec
);
64 HttpHdrRangeSpec::parseInit(const char *field
, int flen
)
71 /* is it a suffix-byte-range-spec ? */
73 if (!httpHeaderParseOffset(field
+ 1, &length
) || !known_spec(length
))
76 /* must have a '-' somewhere in _this_ field */
77 if (!((p
= strchr(field
, '-')) && (p
- field
< flen
))) {
78 debugs(64, 2, "invalid (missing '-') range-spec near: '" << field
<< "'");
81 if (!httpHeaderParseOffset(field
, &offset
) || !known_spec(offset
))
86 /* do we have last-pos ? */
87 if (p
- field
< flen
) {
90 if (!httpHeaderParseOffset(p
, &last_pos
) || !known_spec(last_pos
))
93 // RFC 2616 s14.35.1 MUST: last-byte-pos >= first-byte-pos
94 if (last_pos
< offset
) {
95 debugs(64, 2, "invalid (last-byte-pos < first-byte-pos) range-spec near: " << field
);
99 HttpHdrRangeSpec::HttpRange
aSpec (offset
, last_pos
+ 1);
101 length
= aSpec
.size();
109 HttpHdrRangeSpec::packInto(Packable
* p
) const
111 if (!known_spec(offset
)) /* suffix */
112 p
->appendf("-%" PRId64
, length
);
113 else if (!known_spec(length
)) /* trailer */
114 p
->appendf("%" PRId64
"-", offset
);
116 p
->appendf("%" PRId64
"-%" PRId64
, offset
, offset
+ length
- 1);
120 HttpHdrRangeSpec::outputInfo( char const *note
) const
122 debugs(64, 5, "HttpHdrRangeSpec::canonize: " << note
<< ": [" <<
123 offset
<< ", " << offset
+ length
<<
124 ") len: " << length
);
127 /* fills "absent" positions in range specification based on response body size
128 * returns true if the range is still valid
129 * range is valid if its intersection with [0,length-1] is not empty
132 HttpHdrRangeSpec::canonize(int64_t clen
)
135 HttpRange
object(0, clen
);
137 if (!known_spec(offset
)) { /* suffix */
138 assert(known_spec(length
));
139 offset
= object
.intersection(HttpRange (clen
- length
, clen
)).start
;
140 } else if (!known_spec(length
)) { /* trailer */
141 assert(known_spec(offset
));
142 HttpRange newRange
= object
.intersection(HttpRange (offset
, clen
));
143 length
= newRange
.size();
145 /* we have a "range" now, adjust length if needed */
146 assert(known_spec(length
));
148 assert(known_spec(offset
));
150 HttpRange newRange
= object
.intersection (HttpRange (offset
, offset
+ length
));
152 length
= newRange
.size();
159 /* merges recipient with donor if possible; returns true on success
160 * both specs must be canonized prior to merger, of course */
162 HttpHdrRangeSpec::mergeWith(const HttpHdrRangeSpec
* donor
)
165 #if MERGING_BREAKS_NOTHING
166 /* Note: this code works, but some clients may not like its effects */
167 int64_t rhs
= offset
+ length
; /* no -1 ! */
168 const int64_t donor_rhs
= donor
->offset
+ donor
->length
; /* no -1 ! */
169 assert(known_spec(offset
));
170 assert(known_spec(donor
->offset
));
172 assert(donor
->length
> 0);
173 /* do we have a left hand side overlap? */
175 if (donor
->offset
< offset
&& offset
<= donor_rhs
) {
176 offset
= donor
->offset
; /* decrease left offset */
180 /* do we have a right hand side overlap? */
181 if (donor
->offset
<= rhs
&& rhs
< donor_rhs
) {
182 rhs
= donor_rhs
; /* increase right offset */
186 /* adjust length if offsets have been changed */
188 assert(rhs
> offset
);
189 length
= rhs
- offset
;
191 /* does recipient contain donor? */
193 offset
<= donor
->offset
&& donor
->offset
< rhs
;
204 HttpHdrRange::HttpHdrRange() : clen(HttpHdrRangeSpec::UnknownPosition
)
208 HttpHdrRange::ParseCreate(const String
* range_spec
)
210 HttpHdrRange
*r
= new HttpHdrRange
;
212 if (!r
->parseInit(range_spec
)) {
220 /* returns true if ranges are valid; inits HttpHdrRange */
222 HttpHdrRange::parseInit(const String
* range_spec
)
225 const char *pos
= NULL
;
229 debugs(64, 8, "parsing range field: '" << *range_spec
<< "'");
230 /* check range type */
232 if (range_spec
->caseCmp("bytes=", 6))
235 /* skip "bytes="; hack! */
236 pos
= range_spec
->termedBuf() + 6;
238 /* iterate through comma separated list */
239 while (strListGetItem(range_spec
, ',', &item
, &ilen
, &pos
)) {
240 HttpHdrRangeSpec
*spec
= HttpHdrRangeSpec::Create(item
, ilen
);
242 * RFC 2616 section 14.35.1: MUST ignore Range with
243 * at least one syntactically invalid byte-range-specs.
246 while (!specs
.empty()) {
250 debugs(64, 2, "ignoring invalid range field: '" << *range_spec
<< "'");
254 specs
.push_back(spec
);
257 debugs(64, 8, "got range specs: " << specs
.size());
258 return !specs
.empty();
261 HttpHdrRange::~HttpHdrRange()
263 while (!specs
.empty()) {
269 HttpHdrRange::HttpHdrRange(HttpHdrRange
const &old
) :
271 clen(HttpHdrRangeSpec::UnknownPosition
)
273 specs
.reserve(old
.specs
.size());
275 for (const_iterator i
= old
.begin(); i
!= old
.end(); ++i
)
276 specs
.push_back(new HttpHdrRangeSpec ( **i
));
278 assert(old
.specs
.size() == specs
.size());
281 HttpHdrRange::iterator
282 HttpHdrRange::begin()
284 return specs
.begin();
287 HttpHdrRange::iterator
293 HttpHdrRange::const_iterator
294 HttpHdrRange::begin() const
296 return specs
.begin();
299 HttpHdrRange::const_iterator
300 HttpHdrRange::end() const
306 HttpHdrRange::packInto(Packable
* packer
) const
308 const_iterator pos
= begin();
310 while (pos
!= end()) {
312 packer
->append(",", 1);
314 (*pos
)->packInto(packer
);
321 HttpHdrRange::merge (std::vector
<HttpHdrRangeSpec
*> &basis
)
323 /* reset old array */
326 * take one spec from "goods" and merge it with specs from
327 * "specs" (if any) until there is no overlap */
328 iterator i
= basis
.begin();
330 while (i
!= basis
.end()) {
331 if (specs
.size() && (*i
)->mergeWith(specs
.back())) {
332 /* merged with current so get rid of the prev one */
335 continue; /* re-iterate */
338 specs
.push_back (*i
);
342 debugs(64, 3, "HttpHdrRange::merge: had " << basis
.size() <<
343 " specs, merged " << basis
.size() - specs
.size() << " specs");
347 HttpHdrRange::getCanonizedSpecs(std::vector
<HttpHdrRangeSpec
*> ©
)
349 /* canonize each entry and destroy bad ones if any */
351 for (iterator
pos (begin()); pos
!= end(); ++pos
) {
352 if ((*pos
)->canonize(clen
))
353 copy
.push_back (*pos
);
358 debugs(64, 3, "found " << specs
.size() - copy
.size() << " bad specs");
361 #include "HttpHdrContRange.h"
364 * canonizes all range specs within a set preserving the order
365 * returns true if the set is valid after canonization;
366 * the set is valid if
367 * - all range specs are valid and
368 * - there is at least one range spec
371 HttpHdrRange::canonize(HttpReply
*rep
)
375 if (rep
->contentRange())
376 clen
= rep
->contentRange()->elength
;
378 clen
= rep
->content_length
;
380 return canonize (clen
);
384 HttpHdrRange::canonize (int64_t newClen
)
387 debugs(64, 3, "HttpHdrRange::canonize: started with " << specs
.size() <<
388 " specs, clen: " << clen
);
389 std::vector
<HttpHdrRangeSpec
*> goods
;
390 getCanonizedSpecs(goods
);
392 debugs(64, 3, "HttpHdrRange::canonize: finished with " << specs
.size() <<
394 return specs
.size() > 0; // TODO: should return bool
397 /* hack: returns true if range specs are too "complex" for Squid to handle */
398 /* requires that specs are "canonized" first! */
400 HttpHdrRange::isComplex() const
403 /* check that all rangers are in "strong" order */
404 const_iterator
pos (begin());
406 while (pos
!= end()) {
407 /* Ensure typecasts is safe */
408 assert ((*pos
)->offset
>= 0);
410 if ((*pos
)->offset
< offset
)
413 offset
= (*pos
)->offset
+ (*pos
)->length
;
422 * hack: returns true if range specs may be too "complex" when "canonized".
423 * see also: HttpHdrRange::isComplex.
426 HttpHdrRange::willBeComplex() const
428 /* check that all rangers are in "strong" order, */
429 /* as far as we can tell without the content length */
432 for (const_iterator
pos (begin()); pos
!= end(); ++pos
) {
433 if (!known_spec((*pos
)->offset
)) /* ignore unknowns */
436 /* Ensure typecasts is safe */
437 assert ((*pos
)->offset
>= 0);
439 if ((*pos
)->offset
< offset
)
442 offset
= (*pos
)->offset
;
444 if (known_spec((*pos
)->length
)) /* avoid unknowns */
445 offset
+= (*pos
)->length
;
452 * Returns lowest known offset in range spec(s),
453 * or HttpHdrRangeSpec::UnknownPosition
454 * this is used for size limiting
457 HttpHdrRange::firstOffset() const
459 int64_t offset
= HttpHdrRangeSpec::UnknownPosition
;
460 const_iterator pos
= begin();
462 while (pos
!= end()) {
463 if ((*pos
)->offset
< offset
|| !known_spec(offset
))
464 offset
= (*pos
)->offset
;
473 * Returns lowest offset in range spec(s), 0 if unknown.
474 * This is used for finding out where we need to start if all
475 * ranges are combined into one, for example FTP REST.
476 * Use 0 for size if unknown
479 HttpHdrRange::lowestOffset(int64_t size
) const
481 int64_t offset
= HttpHdrRangeSpec::UnknownPosition
;
482 const_iterator pos
= begin();
484 while (pos
!= end()) {
485 int64_t current
= (*pos
)->offset
;
487 if (!known_spec(current
)) {
488 if ((*pos
)->length
> size
|| !known_spec((*pos
)->length
))
489 return 0; /* Unknown. Assume start of file */
491 current
= size
- (*pos
)->length
;
494 if (current
< offset
|| !known_spec(offset
))
500 return known_spec(offset
) ? offset
: 0;
504 * \retval true Fetch only requested ranges. The first range is larger that configured limit.
505 * \retval false Full download. Not a range request, no limit, or the limit is not yet reached.
508 HttpHdrRange::offsetLimitExceeded(const int64_t limit
) const
515 /* 'none' == forced */
518 if (firstOffset() == -1)
522 if (limit
>= firstOffset())
523 /* below the limit */
529 const HttpHdrRangeSpec
*
530 HttpHdrRangeIter::currentSpec() const
539 HttpHdrRangeIter::updateSpec()
541 assert (debt_size
== 0);
545 debt(currentSpec()->length
);
550 HttpHdrRangeIter::debt() const
552 debugs(64, 3, "HttpHdrRangeIter::debt: debt is " << debt_size
);
556 void HttpHdrRangeIter::debt(int64_t newDebt
)
558 debugs(64, 3, "HttpHdrRangeIter::debt: was " << debt_size
<< " now " << newDebt
);