src/HttpHdrContRange.cc

   1
   2 /*
   3  * $Id: HttpHdrContRange.cc,v 1.10 1998/12/05 00:54:09 wessels Exp $
   4  *
   5  * DEBUG: section 68    HTTP Content-Range Header
   6  * AUTHOR: Alex Rousskov
   7  *
   8  * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
   9  * ----------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from the
  12  *  Internet community.  Development is led by Duane Wessels of the
  13  *  National Laboratory for Applied Network Research and funded by the
  14  *  National Science Foundation.  Squid is Copyrighted (C) 1998 by
  15  *  Duane Wessels and the University of California San Diego.  Please
  16  *  see the COPYRIGHT file for full details.  Squid incorporates
  17  *  software developed and/or copyrighted by other sources.  Please see
  18  *  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.h"
  37
  38 /*
  39  *    Currently only byte ranges are supported
  40  *
  41  *    Content-Range = "Content-Range" ":" content-range-spec
  42  *    content-range-spec      = byte-content-range-spec
  43  *    byte-content-range-spec = bytes-unit SP
  44  *                              ( byte-range-resp-spec | "*") "/"
  45  *                              ( entity-length | "*" )
  46  *    byte-range-resp-spec = first-byte-pos "-" last-byte-pos
  47  *    entity-length        = 1*DIGIT
  48  */
  49
  50
  51 /* local constants */
  52 #define range_spec_unknown ((size_t)-1)
  53
  54 /* local routines */
  55 #define known_spec(s) ((s) != range_spec_unknown)
  56 #define size_min(a,b) ((a) <= (b) ? (a) : (b))
  57 #define size_diff(a,b) ((a) >= (b) ? ((a)-(b)) : 0)
  58
  59 /* globals */
  60
  61 /* parses range-resp-spec and inits spec, returns true on success */
  62 static int
  63 httpHdrRangeRespSpecParseInit(HttpHdrRangeSpec * spec, const char *field, int flen)
  64 {
  65     const char *p;
  66     assert(spec);
  67     spec->offset = spec->length = range_spec_unknown;
  68     if (flen < 2)
  69         return 0;
  70     /* is spec given ? */
  71     if (*field == '*')
  72         return 1;
  73     /* check format, must be %d-%d */
  74     if (!((p = strchr(field, '-')) && (p - field < flen))) {
  75         debug(68, 2) ("invalid (no '-') resp-range-spec near: '%s'\n", field);
  76         return 0;
  77     }
  78     /* parse offset */
  79     if (!httpHeaderParseSize(field, &spec->offset))
  80         return 0;
  81     p++;
  82     /* do we have last-pos ? */
  83     if (p - field < flen) {
  84         size_t last_pos;
  85         if (!httpHeaderParseSize(p, &last_pos))
  86             return 0;
  87         spec->length = size_diff(last_pos + 1, spec->offset);
  88     }
  89     /* we managed to parse, check if the result makes sence */
  90     if (known_spec(spec->length) && !spec->length) {
  91         debug(68, 2) ("invalid range (%d += %d) in resp-range-spec near: '%s'\n",
  92             spec->offset, spec->length, field);
  93         return 0;
  94     }
  95     return 1;
  96 }
  97
  98 static void
  99 httpHdrRangeRespSpecPackInto(const HttpHdrRangeSpec * spec, Packer * p)
 100 {
 101     if (!known_spec(spec->offset) || !known_spec(spec->length))
 102         packerPrintf(p, "*");
 103     else
 104         packerPrintf(p, "bytes %d-%d",
 105             spec->offset, spec->offset + spec->length - 1);
 106 }
 107
 108 /*
 109  * Content Range
 110  */
 111
 112 HttpHdrContRange *
 113 httpHdrContRangeCreate()
 114 {
 115     HttpHdrContRange *r = memAllocate(MEM_HTTP_HDR_CONTENT_RANGE);
 116     r->spec.offset = r->spec.length = range_spec_unknown;
 117     r->elength = range_spec_unknown;
 118     return r;
 119 }
 120
 121 HttpHdrContRange *
 122 httpHdrContRangeParseCreate(const char *str)
 123 {
 124     HttpHdrContRange *r = httpHdrContRangeCreate();
 125     if (!httpHdrContRangeParseInit(r, str)) {
 126         httpHdrContRangeDestroy(r);
 127         r = NULL;
 128     }
 129     return r;
 130 }
 131
 132 /* returns true if ranges are valid; inits HttpHdrContRange */
 133 int
 134 httpHdrContRangeParseInit(HttpHdrContRange * range, const char *str)
 135 {
 136     const char *p;
 137     assert(range && str);
 138     debug(68, 8) ("parsing content-range field: '%s'\n", str);
 139     /* check range type */
 140     if (strncasecmp(str, "bytes ", 6))
 141         return 0;
 142     str += 6;
 143     /* split */
 144     if (!(p = strchr(str, '/')))
 145         return 0;
 146     if (*str == '*')
 147         range->spec.offset = range->spec.length = range_spec_unknown;
 148     else if (!httpHdrRangeRespSpecParseInit(&range->spec, str, p - str))
 149         return 0;
 150     p++;
 151     if (*p == '*')
 152         range->elength = range_spec_unknown;
 153     else if (!httpHeaderParseSize(p, &range->elength))
 154         return 0;
 155     debug(68, 8) ("parsed content-range field: %d-%d / %d\n",
 156         range->spec.offset, range->spec.offset + range->spec.length - 1,
 157         range->elength);
 158     return 1;
 159 }
 160
 161 void
 162 httpHdrContRangeDestroy(HttpHdrContRange * range)
 163 {
 164     assert(range);
 165     memFree(range, MEM_HTTP_HDR_CONTENT_RANGE);
 166 }
 167
 168 HttpHdrContRange *
 169 httpHdrContRangeDup(const HttpHdrContRange * range)
 170 {
 171     HttpHdrContRange *dup;
 172     assert(range);
 173     dup = httpHdrContRangeCreate();
 174     *dup = *range;
 175     return dup;
 176 }
 177
 178 void
 179 httpHdrContRangePackInto(const HttpHdrContRange * range, Packer * p)
 180 {
 181     assert(range && p);
 182     httpHdrRangeRespSpecPackInto(&range->spec, p);
 183     if (!known_spec(range->elength))
 184         packerPrintf(p, "/*");
 185     else
 186         packerPrintf(p, "/%d", range->elength);
 187 }
 188
 189 void
 190 httpHdrContRangeSet(HttpHdrContRange * cr, HttpHdrRangeSpec spec, size_t ent_len)
 191 {
 192     assert(cr && ent_len >= 0);
 193     cr->spec = spec;
 194     cr->elength = ent_len;
 195 }