| | varnish-cache/bin/varnishd/cache/cache_vary.c |
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/*- |
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* Copyright (c) 2006-2015 Varnish Software AS |
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* All rights reserved. |
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* |
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* Author: Poul-Henning Kamp <phk@phk.freebsd.dk> |
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* |
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* SPDX-License-Identifier: BSD-2-Clause |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* |
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* Do Vary processing. |
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* |
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* When we insert an object into the cache which has a Vary: header, |
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* we encode a vary matching string containing the headers mentioned |
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* and their value. |
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* |
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* When we match an object in the cache, we check the present request |
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* against the vary matching string. |
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* |
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* The only kind of header-munging we do is leading & trailing space |
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* removal. All the potential "q=foo" gymnastics is not worth the |
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* effort. |
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* |
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* The vary matching string has the following format: |
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* |
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* Sequence of: { |
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* <msb> \ Length of header contents. |
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* <lsb> / |
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* <length of header + 1> \ |
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* <header> \ Same format as argument to http_GetHdr() |
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* ':' / |
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* '\0' / |
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* <header> > Only present if length != 0xffff |
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* } |
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* 0xff, \ Length field |
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* 0xff, / |
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* '\0' > Terminator |
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*/ |
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#include "config.h" |
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|
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#include <stdlib.h> |
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#include "cache_varnishd.h" |
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#include "vct.h" |
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#include "vend.h" |
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static unsigned VRY_Validate(const uint8_t *vary); |
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|
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/********************************************************************** |
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* Create a Vary matching string from a Vary header |
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* |
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* Return value: |
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* <0: Parse error |
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* 0: No Vary header on object |
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* >0: Length of Vary matching string in *psb |
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*/ |
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|
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int |
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VRY_Create(struct busyobj *bo, struct vsb **psb) |
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{ |
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const char *v, *p, *q, *h, *e; |
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struct vsb *sb, *sbh; |
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unsigned l; |
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56239 |
int error = 0; |
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|
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56239 |
CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC); |
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56239 |
CHECK_OBJ_NOTNULL(bo->bereq, HTTP_MAGIC); |
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56239 |
CHECK_OBJ_NOTNULL(bo->beresp, HTTP_MAGIC); |
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56239 |
AN(psb); |
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56239 |
AZ(*psb); |
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|
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/* No Vary: header, no worries */ |
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if (!http_GetHdr(bo->beresp, H_Vary, &v)) |
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return (0); |
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|
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/* For vary matching string */ |
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sb = VSB_new_auto(); |
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AN(sb); |
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|
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/* For header matching strings */ |
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sbh = VSB_new_auto(); |
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AN(sbh); |
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|
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for (p = v; *p; p++) { |
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|
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/* Find next header-name */ |
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if (vct_issp(*p)) |
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continue; |
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for (q = p; *q && !vct_issp(*q) && *q != ','; q++) |
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continue; |
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|
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if (q - p > INT8_MAX) { |
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VSLb(bo->vsl, SLT_Error, |
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"Vary header name length exceeded"); |
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error = 1; |
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break; |
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} |
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|
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/* Build a header-matching string out of it */ |
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VSB_clear(sbh); |
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AZ(VSB_printf(sbh, "%c%.*s:%c", |
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(char)(1 + (q - p)), (int)(q - p), p, 0)); |
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AZ(VSB_finish(sbh)); |
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|
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if (http_GetHdr(bo->bereq, VSB_data(sbh), &h)) { |
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AZ(vct_issp(*h)); |
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/* Trim trailing space */ |
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e = strchr(h, '\0'); |
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while (e > h && vct_issp(e[-1])) |
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e--; |
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/* Encode two byte length and contents */ |
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l = e - h; |
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if (l > 0xffff - 1) { |
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VSLb(bo->vsl, SLT_Error, |
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"Vary header maximum length exceeded"); |
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error = 1; |
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break; |
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} |
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} else { |
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e = h; |
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l = 0xffff; |
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} |
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AZ(VSB_printf(sb, "%c%c", (int)(l >> 8), (int)(l & 0xff))); |
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/* Append to vary matching string */ |
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AZ(VSB_bcat(sb, VSB_data(sbh), VSB_len(sbh))); |
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if (e != h) |
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AZ(VSB_bcat(sb, h, e - h)); |
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|
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while (vct_issp(*q)) |
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q++; |
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if (*q == '\0') |
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break; |
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if (*q != ',') { |
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VSLb(bo->vsl, SLT_Error, "Malformed Vary header"); |
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error = 1; |
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break; |
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} |
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p = q; |
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} |
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if (error) { |
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VSB_destroy(&sbh); |
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VSB_destroy(&sb); |
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return (-1); |
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} |
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/* Terminate vary matching string */ |
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VSB_printf(sb, "%c%c%c", 0xff, 0xff, 0); |
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VSB_destroy(&sbh); |
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AZ(VSB_finish(sb)); |
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*psb = sb; |
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return (VSB_len(sb)); |
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} |
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/* |
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* Find length of a vary entry |
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*/ |
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static unsigned |
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VRY_Len(const uint8_t *p) |
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{ |
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unsigned l = vbe16dec(p); |
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return (2 + p[2] + 2 + (l == 0xffff ? 0 : l)); |
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} |
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/* |
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* Compare two vary entries |
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*/ |
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static int |
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121269 |
vry_cmp(const uint8_t *v1, const uint8_t *v2) |
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{ |
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unsigned retval = 0; |
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|
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if (!memcmp(v1, v2, VRY_Len(v1))) { |
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/* Same same */ |
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retval = 0; |
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} else if (memcmp(v1 + 2, v2 + 2, v1[2] + 2)) { |
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/* Different header */ |
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retval = 1; |
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} else if (cache_param->http_gzip_support && |
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http_hdr_eq(H_Accept_Encoding, (const char*) v1 + 2)) { |
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/* |
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* If we do gzip processing, we do not vary on Accept-Encoding, |
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* because we want everybody to get the gzipped object, and |
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* varnish will gunzip as necessary. We implement the skip at |
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* check time, rather than create time, so that object in |
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* persistent storage can be used with either setting of |
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* http_gzip_support. |
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*/ |
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retval = 0; |
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} else { |
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/* Same header, different content */ |
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retval = 2; |
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} |
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return (retval); |
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} |
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/********************************************************************** |
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* Prepare predictive vary string |
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*/ |
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|
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void |
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VRY_Prep(struct req *req) |
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{ |
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if (req->hash_objhead == NULL) { |
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/* Not a waiting list return */ |
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AZ(req->vary_b); |
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AZ(req->vary_e); |
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(void)WS_ReserveAll(req->ws); |
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} else { |
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AN(WS_Reservation(req->ws)); |
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} |
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req->vary_b = WS_Reservation(req->ws); |
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req->vary_e = req->vary_b + WS_ReservationSize(req->ws); |
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if (req->vary_b + 2 < req->vary_e) |
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req->vary_b[2] = '\0'; |
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} |
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|
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void |
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VRY_Clear(struct req *req) |
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{ |
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|
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CHECK_OBJ_NOTNULL(req, REQ_MAGIC); |
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if (req->vary_b != NULL) |
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free(req->vary_b); |
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req->vary_b = NULL; |
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AZ(req->vary_e); |
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} |
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|
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/********************************************************************** |
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* Finish predictive vary processing |
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*/ |
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|
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void |
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98736 |
VRY_Finish(struct req *req, enum vry_finish_flag flg) |
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{ |
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uint8_t *p = NULL; |
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size_t l; |
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|
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98736 |
if (req->vary_b + 2 >= req->vary_e) { |
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req->vary_b = NULL; |
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req->vary_e = NULL; |
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WS_Release(req->ws, 0); |
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WS_MarkOverflow(req->ws); |
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return; |
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} |
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|
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l = VRY_Validate(req->vary_b); |
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if (flg == KEEP && l > 3) { |
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p = malloc(l); |
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if (p != NULL) |
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memcpy(p, req->vary_b, l); |
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} |
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WS_Release(req->ws, 0); |
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req->vary_e = NULL; |
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req->vary_b = p; |
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98736 |
} |
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|
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/********************************************************************** |
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* Match vary strings, and build a new cached string if possible. |
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* |
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* Return zero if there is certainly no match. |
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* Return non-zero if there could be a match or if we couldn't tell. |
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*/ |
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|
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int |
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110824 |
VRY_Match(const struct req *req, const uint8_t *vary) |
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{ |
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110824 |
uint8_t *vsp = req->vary_b; |
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const char *h, *e; |
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unsigned lh, ln; |
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110824 |
int i, oflo = 0; |
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|
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110824 |
AN(vsp); |
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110824 |
AN(vary); |
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while (vary[2]) { |
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111144 |
if (vsp + 2 >= req->vary_e) { |
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/* |
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* Too little workspace to find out |
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*/ |
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oflo = 1; |
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break; |
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} |
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111144 |
i = vry_cmp(vary, vsp); |
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111144 |
if (i == 1) { |
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/* |
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* Different header, build a new entry, |
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* then compare again with that new entry. |
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*/ |
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|
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10165 |
ln = 2 + vary[2] + 2; |
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10165 |
i = http_GetHdr(req->http, (const char*)(vary+2), &h); |
314 |
10165 |
if (i) { |
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/* Trim trailing space */ |
316 |
5805 |
e = strchr(h, '\0'); |
317 |
5805 |
while (e > h && vct_issp(e[-1])) |
318 |
0 |
e--; |
319 |
5805 |
lh = e - h; |
320 |
5805 |
assert(lh < 0xffff); |
321 |
5805 |
ln += lh; |
322 |
5805 |
} else { |
323 |
4360 |
e = h = NULL; |
324 |
4360 |
lh = 0xffff; |
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} |
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|
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10165 |
if (vsp + ln + 3 >= req->vary_e) { |
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/* |
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* Not enough space to build new entry |
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* and put terminator behind it. |
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*/ |
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oflo = 1; |
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break; |
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} |
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|
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vbe16enc(vsp, (uint16_t)lh); |
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10125 |
memcpy(vsp + 2, vary + 2, vary[2] + 2); |
338 |
10125 |
if (h != NULL) |
339 |
5765 |
memcpy(vsp + 2 + vsp[2] + 2, h, lh); |
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10125 |
vsp[ln++] = 0xff; |
341 |
10125 |
vsp[ln++] = 0xff; |
342 |
10125 |
vsp[ln++] = 0; |
343 |
10125 |
assert(VRY_Validate(vsp) == ln); |
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|
345 |
10125 |
i = vry_cmp(vary, vsp); |
346 |
10125 |
assert(i == 0 || i == 2); |
347 |
10125 |
} |
348 |
111104 |
if (i == 0) { |
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/* Same header, same contents */ |
350 |
6359 |
vsp += VRY_Len(vsp); |
351 |
6359 |
vary += VRY_Len(vary); |
352 |
111104 |
} else if (i == 2) { |
353 |
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/* Same header, different contents, cannot match */ |
354 |
104745 |
return (0); |
355 |
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} |
356 |
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} |
357 |
6079 |
if (oflo) { |
358 |
40 |
vsp = req->vary_b; |
359 |
40 |
if (vsp + 2 < req->vary_e) { |
360 |
40 |
vsp[0] = 0xff; |
361 |
40 |
vsp[1] = 0xff; |
362 |
40 |
vsp[2] = 0; |
363 |
40 |
} |
364 |
40 |
return (0); |
365 |
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} else { |
366 |
6039 |
return (1); |
367 |
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} |
368 |
110824 |
} |
369 |
|
|
370 |
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/* |
371 |
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* Check the validity of a Vary string and return its total length |
372 |
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*/ |
373 |
|
|
374 |
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static unsigned |
375 |
108821 |
VRY_Validate(const uint8_t *vary) |
376 |
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{ |
377 |
108821 |
unsigned l, retval = 0; |
378 |
|
|
379 |
128986 |
while (vary[2] != 0) { |
380 |
20165 |
assert(strlen((const char*)vary + 3) == vary[2]); |
381 |
20165 |
l = VRY_Len(vary); |
382 |
20165 |
retval += l; |
383 |
20165 |
vary += l; |
384 |
|
} |
385 |
108821 |
return (retval + 3); |
386 |
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} |