HttpHdrContRange.cc
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1/*
2 * Copyright (C) 1996-2022 The Squid Software Foundation and contributors
3 *
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.
7 */
8
9/* DEBUG: section 68 HTTP Content-Range Header */
10
11#include "squid.h"
12#include "base/Packable.h"
13#include "debug/Stream.h"
14#include "enums.h"
15#include "HttpHdrContRange.h"
16#include "HttpHeaderTools.h"
17
18/*
19 * Currently only byte ranges are supported
20 *
21 * Content-Range = "Content-Range" ":" content-range-spec
22 * content-range-spec = byte-content-range-spec
23 * byte-content-range-spec = bytes-unit SP
24 * ( byte-range-resp-spec | "*") "/"
25 * ( entity-length | "*" )
26 * byte-range-resp-spec = first-byte-pos "-" last-byte-pos
27 * entity-length = 1*DIGIT
28 */
29
30/* local constants */
31#define range_spec_unknown (-1)
32
33/* local routines */
34#define known_spec(s) ((s) != range_spec_unknown)
35#define size_min(a,b) ((a) <= (b) ? (a) : (b))
36#define size_diff(a,b) ((a) >= (b) ? ((a)-(b)) : 0)
37
38/* globals */
39
40/* parses range-resp-spec and inits spec, returns true on success */
41static int
42httpHdrRangeRespSpecParseInit(HttpHdrRangeSpec * spec, const char *field, int flen)
43{
44 const char *p;
45 assert(spec);
46 spec->offset = spec->length = range_spec_unknown;
47
48 if (flen < 2)
49 return 0;
50
51 /* is spec given ? */
52 if (*field == '*')
53 return 1;
54
55 /* check format, must be %d-%d */
56 if (!((p = strchr(field, '-')) && (p - field < flen))) {
57 debugs(68, 2, "invalid (no '-') resp-range-spec near: '" << field << "'");
58 return 0;
59 }
60
61 /* parse offset */
62 if (!httpHeaderParseOffset(field, &spec->offset))
63 return 0;
64
65 /* Additional check for BUG2155 - there MUST BE first-byte-pos and it MUST be positive*/
66 if (spec->offset < 0) {
67 debugs(68, 2, "invalid (no first-byte-pos or it is negative) resp-range-spec near: '" << field << "'");
68 return 0;
69 }
70
71 ++p;
72
73 /* do we have last-pos ? */
74 if (p - field >= flen) {
75 debugs(68, 2, "invalid (no last-byte-pos) resp-range-spec near: '" << field << "'");
76 return 0;
77 }
78
79 int64_t last_pos;
80
81 if (!httpHeaderParseOffset(p, &last_pos))
82 return 0;
83
84 if (last_pos < spec->offset) {
85 debugs(68, 2, "invalid (negative last-byte-pos) resp-range-spec near: '" << field << "'");
86 return 0;
87 }
88
89 spec->length = size_diff(last_pos + 1, spec->offset);
90
91 /* we managed to parse, check if the result makes sence */
92 if (spec->length <= 0) {
93 debugs(68, 2, "invalid range (" << spec->offset << " += " <<
94 (long int) spec->length << ") in resp-range-spec near: '" << field << "'");
95 return 0;
96 }
97
98 return 1;
99}
100
101static void
103{
104 /* Ensure typecast is safe */
105 assert (spec->length >= 0);
106
107 if (!known_spec(spec->offset) || !known_spec(spec->length))
108 p->append("*", 1);
109 else
110 p->appendf("bytes %" PRId64 "-%" PRId64, spec->offset, spec->offset + spec->length - 1);
111}
112
113/*
114 * Content Range
115 */
116
119{
123 return r;
124}
125
128{
130
131 if (!httpHdrContRangeParseInit(r, str)) {
132 delete r;
133 return nullptr;
134 }
135
136 return r;
137}
138
139/* returns true if ranges are valid; inits HttpHdrContRange */
140int
142{
143 const char *p;
144 assert(range && str);
145 debugs(68, 8, "parsing content-range field: '" << str << "'");
146 /* check range type */
147
148 if (strncasecmp(str, "bytes ", 6))
149 return 0;
150
151 str += 6;
152
153 /* split */
154 if (!(p = strchr(str, '/')))
155 return 0;
156
157 if (*str == '*')
158 range->spec.offset = range->spec.length = range_spec_unknown;
159 else if (!httpHdrRangeRespSpecParseInit(&range->spec, str, p - str))
160 return 0;
161
162 ++p;
163
164 if (*p == '*') {
165 if (!known_spec(range->spec.offset)) {
166 debugs(68, 2, "invalid (*/*) content-range-spec near: '" << str << "'");
167 return 0;
168 }
170 } else if (!httpHeaderParseOffset(p, &range->elength))
171 return 0;
172 else if (range->elength <= 0) {
173 /* Additional paranoidal check for BUG2155 - entity-length MUST be > 0 */
174 debugs(68, 2, "invalid (entity-length is negative) content-range-spec near: '" << str << "'");
175 return 0;
176 } else if (known_spec(range->spec.length) && range->elength < (range->spec.offset + range->spec.length)) {
177 debugs(68, 2, "invalid (range is outside entity-length) content-range-spec near: '" << str << "'");
178 return 0;
179 }
180
181 // reject unsatisfied-range and such; we only use well-defined ranges today
182 if (!known_spec(range->spec.offset) || !known_spec(range->spec.length)) {
183 debugs(68, 2, "unwanted content-range-spec near: '" << str << "'");
184 return 0;
185 }
186
187 debugs(68, 8, "parsed content-range field: " <<
188 (long int) range->spec.offset << "-" <<
189 (long int) range->spec.offset + range->spec.length - 1 << " / " <<
190 (long int) range->elength);
191
192 return 1;
193}
194
197{
198 HttpHdrContRange *dup;
199 assert(range);
201 *dup = *range;
202 return dup;
203}
204
205void
207{
208 assert(range && p);
210 /* Ensure typecast is safe */
211 assert (range->elength >= 0);
212
213 if (!known_spec(range->elength))
214 p->append("/*", 2);
215 else
216 p->appendf("/%" PRId64, range->elength);
217}
218
219void
221{
222 assert(cr && ent_len >= 0);
223 cr->spec = spec;
224 cr->elength = ent_len;
225}
226
#define size_diff(a, b)
HttpHdrContRange * httpHdrContRangeCreate(void)
static void httpHdrRangeRespSpecPackInto(const HttpHdrRangeSpec *spec, Packable *p)
static int httpHdrRangeRespSpecParseInit(HttpHdrRangeSpec *spec, const char *field, int flen)
HttpHdrContRange * httpHdrContRangeDup(const HttpHdrContRange *range)
#define known_spec(s)
void httpHdrContRangePackInto(const HttpHdrContRange *range, Packable *p)
#define range_spec_unknown
void httpHdrContRangeSet(HttpHdrContRange *cr, HttpHdrRangeSpec spec, int64_t ent_len)
int httpHdrContRangeParseInit(HttpHdrContRange *range, const char *str)
HttpHdrContRange * httpHdrContRangeParseCreate(const char *str)
bool httpHeaderParseOffset(const char *start, int64_t *value, char **endPtr)
#define assert(EX)
Definition: assert.h:19
HttpHdrRangeSpec spec
void appendf(const char *fmt,...) PRINTF_FORMAT_ARG2
Append operation with printf-style arguments.
Definition: Packable.h:61
virtual void append(const char *buf, int size)=0
Appends a c-string to existing packed data.
#define debugs(SECTION, LEVEL, CONTENT)
Definition: Stream.h:196
#define PRId64
Definition: types.h:110

 

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