src/HttpHdrContRange.cc

   1
   2 /*
   3  * $Id$
   4  *
   5  * DEBUG: section 68    HTTP Content-Range Header
   6  * AUTHOR: Alex Rousskov
   7  *
   8  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   9  * ----------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from
  12  *  the Internet community; see the CONTRIBUTORS file for full
  13  *  details.   Many organizations have provided support for Squid's
  14  *  development; see the SPONSORS file for full details.  Squid is
  15  *  Copyrighted (C) 2001 by the Regents of the University of
  16  *  California; see the COPYRIGHT file for full details.  Squid
  17  *  incorporates software developed and/or copyrighted by other
  18  *  sources; see the CREDITS file for full details.
  19  *
  20  *  This program is free software; you can redistribute it and/or modify
  21  *  it under the terms of the GNU General Public License as published by
  22  *  the Free Software Foundation; either version 2 of the License, or
  23  *  (at your option) any later version.
  24  *
  25  *  This program is distributed in the hope that it will be useful,
  26  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  *  GNU General Public License for more details.
  29  *
  30  *  You should have received a copy of the GNU General Public License
  31  *  along with this program; if not, write to the Free Software
  32  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  33  *
  34  */
  35
  36 #include "squid-old.h"
  37 #include "HttpHdrContRange.h"
  38
  39 /*
  40  *    Currently only byte ranges are supported
  41  *
  42  *    Content-Range = "Content-Range" ":" content-range-spec
  43  *    content-range-spec      = byte-content-range-spec
  44  *    byte-content-range-spec = bytes-unit SP
  45  *                              ( byte-range-resp-spec | "*") "/"
  46  *                              ( entity-length | "*" )
  47  *    byte-range-resp-spec = first-byte-pos "-" last-byte-pos
  48  *    entity-length        = 1*DIGIT
  49  */
  50
  51
  52 /* local constants */
  53 #define range_spec_unknown (-1)
  54
  55 /* local routines */
  56 #define known_spec(s) ((s) != range_spec_unknown)
  57 #define size_min(a,b) ((a) <= (b) ? (a) : (b))
  58 #define size_diff(a,b) ((a) >= (b) ? ((a)-(b)) : 0)
  59
  60 /* globals */
  61
  62 /* parses range-resp-spec and inits spec, returns true on success */
  63 static int
  64 httpHdrRangeRespSpecParseInit(HttpHdrRangeSpec * spec, const char *field, int flen)
  65 {
  66     const char *p;
  67     assert(spec);
  68     spec->offset = spec->length = range_spec_unknown;
  69
  70     if (flen < 2)
  71         return 0;
  72
  73     /* is spec given ? */
  74     if (*field == '*')
  75         return 1;
  76
  77     /* check format, must be %d-%d */
  78     if (!((p = strchr(field, '-')) && (p - field < flen))) {
  79         debugs(68, 2, "invalid (no '-') resp-range-spec near: '" << field << "'");
  80         return 0;
  81     }
  82
  83     /* parse offset */
  84     if (!httpHeaderParseOffset(field, &spec->offset))
  85         return 0;
  86
  87     /* Additional check for BUG2155 - there MUST BE first-byte-pos and it MUST be positive*/
  88     if (spec->offset < 0) {
  89         debugs(68, 2, "invalid (no first-byte-pos or it is negative) resp-range-spec near: '" << field << "'");
  90         return 0;
  91     }
  92
  93     p++;
  94
  95     /* do we have last-pos ? */
  96     if (p - field >= flen) {
  97         debugs(68, 2, "invalid (no last-byte-pos) resp-range-spec near: '" << field << "'");
  98         return 0;
  99     }
 100
 101     int64_t last_pos;
 102
 103     if (!httpHeaderParseOffset(p, &last_pos))
 104         return 0;
 105
 106     if (last_pos < spec->offset) {
 107         debugs(68, 2, "invalid (negative last-byte-pos) resp-range-spec near: '" << field << "'");
 108         return 0;
 109     }
 110
 111     spec->length = size_diff(last_pos + 1, spec->offset);
 112
 113     /* we managed to parse, check if the result makes sence */
 114     if (spec->length <= 0) {
 115         debugs(68, 2, "invalid range (" << spec->offset << " += " <<
 116                (long int) spec->length << ") in resp-range-spec near: '" << field << "'");
 117         return 0;
 118     }
 119
 120     return 1;
 121 }
 122
 123 static void
 124 httpHdrRangeRespSpecPackInto(const HttpHdrRangeSpec * spec, Packer * p)
 125 {
 126     /* Ensure typecast is safe */
 127     assert (spec->length >= 0);
 128
 129     if (!known_spec(spec->offset) || !known_spec(spec->length))
 130         packerPrintf(p, "*");
 131     else
 132         packerPrintf(p, "bytes %" PRId64 "-%" PRId64,
 133                      spec->offset, spec->offset + spec->length - 1);
 134 }
 135
 136 /*
 137  * Content Range
 138  */
 139
 140 HttpHdrContRange *
 141 httpHdrContRangeCreate(void)
 142 {
 143     HttpHdrContRange *r = (HttpHdrContRange *)memAllocate(MEM_HTTP_HDR_CONTENT_RANGE);
 144     r->spec.offset = r->spec.length = range_spec_unknown;
 145     r->elength = range_spec_unknown;
 146     return r;
 147 }
 148
 149 HttpHdrContRange *
 150 httpHdrContRangeParseCreate(const char *str)
 151 {
 152     HttpHdrContRange *r = httpHdrContRangeCreate();
 153
 154     if (!httpHdrContRangeParseInit(r, str)) {
 155         httpHdrContRangeDestroy(r);
 156         r = NULL;
 157     }
 158
 159     return r;
 160 }
 161
 162 /* returns true if ranges are valid; inits HttpHdrContRange */
 163 int
 164 httpHdrContRangeParseInit(HttpHdrContRange * range, const char *str)
 165 {
 166     const char *p;
 167     assert(range && str);
 168     debugs(68, 8, "parsing content-range field: '" << str << "'");
 169     /* check range type */
 170
 171     if (strncasecmp(str, "bytes ", 6))
 172         return 0;
 173
 174     str += 6;
 175
 176     /* split */
 177     if (!(p = strchr(str, '/')))
 178         return 0;
 179
 180     if (*str == '*')
 181         range->spec.offset = range->spec.length = range_spec_unknown;
 182     else if (!httpHdrRangeRespSpecParseInit(&range->spec, str, p - str))
 183         return 0;
 184
 185     p++;
 186
 187     if (*p == '*')
 188         range->elength = range_spec_unknown;
 189     else if (!httpHeaderParseOffset(p, &range->elength))
 190         return 0;
 191     else if (range->elength <= 0) {
 192         /* Additional paranoidal check for BUG2155 - entity-length MUST be > 0 */
 193         debugs(68, 2, "invalid (entity-length is negative) content-range-spec near: '" << str << "'");
 194         return 0;
 195     } else if (known_spec(range->spec.length) && range->elength < (range->spec.offset + range->spec.length)) {
 196         debugs(68, 2, "invalid (range is outside entity-length) content-range-spec near: '" << str << "'");
 197         return 0;
 198     }
 199
 200     debugs(68, 8, "parsed content-range field: " <<
 201            (long int) range->spec.offset << "-" <<
 202            (long int) range->spec.offset + range->spec.length - 1 << " / " <<
 203            (long int) range->elength);
 204
 205     return 1;
 206 }
 207
 208 void
 209 httpHdrContRangeDestroy(HttpHdrContRange * range)
 210 {
 211     assert(range);
 212     memFree(range, MEM_HTTP_HDR_CONTENT_RANGE);
 213 }
 214
 215 HttpHdrContRange *
 216 httpHdrContRangeDup(const HttpHdrContRange * range)
 217 {
 218     HttpHdrContRange *dup;
 219     assert(range);
 220     dup = httpHdrContRangeCreate();
 221     *dup = *range;
 222     return dup;
 223 }
 224
 225 void
 226 httpHdrContRangePackInto(const HttpHdrContRange * range, Packer * p)
 227 {
 228     assert(range && p);
 229     httpHdrRangeRespSpecPackInto(&range->spec, p);
 230     /* Ensure typecast is safe */
 231     assert (range->elength >= 0);
 232
 233     if (!known_spec(range->elength))
 234         packerPrintf(p, "/*");
 235     else
 236         packerPrintf(p, "/%" PRId64, range->elength);
 237 }
 238
 239 void
 240 httpHdrContRangeSet(HttpHdrContRange * cr, HttpHdrRangeSpec spec, int64_t ent_len)
 241 {
 242     assert(cr && ent_len >= 0);
 243     cr->spec = spec;
 244     cr->elength = ent_len;
 245 }