varnish-cache/bin/varnishd/cache/cache_ws_common.c
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/*-
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 * Copyright (c) 2006 Verdens Gang AS
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 * Copyright (c) 2006-2021 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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 * Author: Dridi Boukelmoune <dridi.boukelmoune@gmail.com>
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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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 */
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#include "config.h"
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#include <stdio.h>
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#include "cache_varnishd.h"
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void
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WS_Id(const struct ws *ws, char *id)
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{
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        WS_Assert(ws);
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        AN(id);
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        memcpy(id, ws->id, WS_ID_SIZE);
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        id[0] |= 0x20;                  // cheesy tolower()
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}
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void
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WS_MarkOverflow(struct ws *ws)
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{
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        CHECK_OBJ_NOTNULL(ws, WS_MAGIC);
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        ws->id[0] &= ~0x20;             // cheesy toupper()
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}
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static void
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ws_ClearOverflow(struct ws *ws)
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{
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        CHECK_OBJ_NOTNULL(ws, WS_MAGIC);
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        ws->id[0] |= 0x20;              // cheesy tolower()
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}
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int
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WS_Overflowed(const struct ws *ws)
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{
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        CHECK_OBJ_NOTNULL(ws, WS_MAGIC);
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        AN(ws->id[0]);
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        if (ws->id[0] & 0x20)           // cheesy islower()
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                return (0);
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        return (1);
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}
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/*
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 * Reset the WS to a cookie or its start and clears any overflow
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 *
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 * for varnishd internal use only
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 */
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void
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WS_Rollback(struct ws *ws, uintptr_t pp)
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{
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        WS_Assert(ws);
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        if (pp == 0)
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                pp = (uintptr_t)ws->s;
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        ws_ClearOverflow(ws);
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        WS_Reset(ws, pp);
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}
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/*--------------------------------------------------------------------*/
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const char *
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WS_Printf(struct ws *ws, const char *fmt, ...)
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{
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        unsigned u, v;
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        va_list ap;
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        char *p;
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        u = WS_ReserveAll(ws);
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        p = ws->f;
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        va_start(ap, fmt);
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        v = vsnprintf(p, u, fmt, ap);
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        va_end(ap);
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        if (v >= u) {
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                WS_Release(ws, 0);
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                WS_MarkOverflow(ws);
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                p = NULL;
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        } else {
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                WS_Release(ws, v + 1);
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        }
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        return (p);
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}
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/*---------------------------------------------------------------------
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 * Build a VSB on a workspace.
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 * Usage pattern:
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 *
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 *      struct vsb vsb[1];
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 *      char *p;
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 *
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 *      WS_VSB_new(vsb, ctx->ws);
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 *      VSB_printf(vsb, "blablabla");
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 *      p = WS_VSB_finish(vsb, ctx->ws, NULL);
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 *      if (p == NULL)
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 *              return (FAILURE);
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 */
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void
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WS_VSB_new(struct vsb *vsb, struct ws *ws)
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{
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        unsigned u;
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        static char bogus[2];   // Smallest possible vsb
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        AN(vsb);
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        WS_Assert(ws);
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        u = WS_ReserveAll(ws);
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        if (WS_Overflowed(ws) || u < 2)
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                AN(VSB_init(vsb, bogus, sizeof bogus));
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        else
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                AN(VSB_init(vsb, WS_Reservation(ws), u));
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}
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char *
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WS_VSB_finish(struct vsb *vsb, struct ws *ws, size_t *szp)
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{
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        char *p;
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        AN(vsb);
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        WS_Assert(ws);
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        if (!VSB_finish(vsb)) {
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                p = VSB_data(vsb);
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                if (p == ws->f) {
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                        WS_Release(ws, VSB_len(vsb) + 1);
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                        if (szp != NULL)
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                                *szp = VSB_len(vsb);
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                        VSB_fini(vsb);
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                        return (p);
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                }
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        }
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        WS_MarkOverflow(ws);
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        VSB_fini(vsb);
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        WS_Release(ws, 0);
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        if (szp)
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                *szp = 0;
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        return (NULL);
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}