varnish-cache/bin/varnishd/http1/cache_http1_line.c
0
/*-
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 * Copyright (c) 2006 Verdens Gang AS
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 * Copyright (c) 2006-2011 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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 * Write data to fd
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 * We try to use writev() if possible in order to minimize number of
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 * syscalls made and packets sent.  It also just might allow the worker
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 * thread to complete the request without holding stuff locked.
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 *
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 * XXX: chunked header (generated in Flush) and Tail (EndChunk)
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 *      are not accounted by means of the size_t returned. Obvious ideas:
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 *      - add size_t return value to Flush and EndChunk
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 *      - base accounting on (struct v1l).cnt
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 */
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#include "config.h"
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#include <sys/uio.h>
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#include "cache/cache_varnishd.h"
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#include "cache/cache_filter.h"
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#include <stdio.h>
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#include "cache_http1.h"
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#include "vtim.h"
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52
/*--------------------------------------------------------------------*/
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54
struct v1l {
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        unsigned                magic;
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#define V1L_MAGIC               0x2f2142e5
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        int                     *wfd;
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        stream_close_t          werr;   /* valid after V1L_Flush() */
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        struct iovec            *iov;
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        int                     siov;
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        int                     niov;
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        size_t                  liov;
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        size_t                  cliov;
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        int                     ciov;   /* Chunked header marker */
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        vtim_real               deadline;
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        struct vsl_log          *vsl;
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        uint64_t                cnt;    /* Flushed byte count */
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        struct ws               *ws;
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        uintptr_t               ws_snap;
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        void                    **vdp_priv;
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};
72
73
/*--------------------------------------------------------------------
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 * for niov == 0, reserve the ws for max number of iovs
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 * otherwise, up to niov
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 */
77
78
struct v1l *
79 25612
V1L_Open(struct ws *ws, int *fd, struct vsl_log *vsl,
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    vtim_real deadline, unsigned niov)
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{
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        struct v1l *v1l;
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        unsigned u;
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        uintptr_t ws_snap;
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        size_t sz;
86
87 25612
        if (WS_Overflowed(ws))
88 0
                return (NULL);
89
90 25612
        if (niov != 0)
91 15112
                assert(niov >= 3);
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93 25612
        ws_snap = WS_Snapshot(ws);
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95 25612
        v1l = WS_Alloc(ws, sizeof *v1l);
96 25612
        if (v1l == NULL)
97 5
                return (NULL);
98 25607
        INIT_OBJ(v1l, V1L_MAGIC);
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100 25607
        v1l->ws = ws;
101 25607
        v1l->ws_snap = ws_snap;
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103 25607
        u = WS_ReserveLumps(ws, sizeof(struct iovec));
104 25607
        if (u < 3) {
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                /* Must have at least 3 in case of chunked encoding */
106 0
                WS_Release(ws, 0);
107 0
                WS_MarkOverflow(ws);
108 0
                return (NULL);
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        }
110 25607
        if (u > IOV_MAX)
111 160
                u = IOV_MAX;
112 25607
        if (niov != 0 && u > niov)
113 14733
                u = niov;
114 25607
        v1l->iov = WS_Reservation(ws);
115 25607
        v1l->siov = (int)u;
116 25607
        v1l->ciov = (int)u;
117 25607
        v1l->wfd = fd;
118 25607
        v1l->deadline = deadline;
119 25607
        v1l->vsl = vsl;
120 25607
        v1l->werr = SC_NULL;
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122 25607
        sz = u * sizeof(struct iovec);
123 25607
        assert(sz < UINT_MAX);
124 25607
        WS_Release(ws, (unsigned)sz);
125 25607
        return (v1l);
126 25612
}
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void
129 160
V1L_NoRollback(struct v1l *v1l)
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{
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132 160
        CHECK_OBJ_NOTNULL(v1l, V1L_MAGIC);
133 160
        v1l->ws_snap = 0;
134 160
}
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stream_close_t
137 25608
V1L_Close(struct v1l **v1lp, uint64_t *cnt)
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{
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        struct v1l *v1l;
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        struct ws *ws;
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        uintptr_t ws_snap;
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        stream_close_t sc;
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144 25608
        AN(cnt);
145 25608
        TAKE_OBJ_NOTNULL(v1l, v1lp, V1L_MAGIC);
146 25608
        if (v1l->vdp_priv != NULL) {
147 20104
                assert(*v1l->vdp_priv == v1l);
148 20104
                *v1l->vdp_priv = NULL;
149 20104
        }
150 25608
        sc = V1L_Flush(v1l);
151 25608
        *cnt = v1l->cnt;
152 25608
        ws = v1l->ws;
153 25608
        ws_snap = v1l->ws_snap;
154 25608
        ZERO_OBJ(v1l, sizeof *v1l);
155 25608
        if (ws_snap != 0)
156 25449
                WS_Rollback(ws, ws_snap);
157 25608
        return (sc);
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}
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static void
161 55
v1l_prune(struct v1l *v1l, ssize_t abytes)
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{
163 55
        size_t used = 0;
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        size_t sz, bytes, used_here;
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        int j;
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167 55
        assert(abytes > 0);
168 55
        bytes = (size_t)abytes;
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170 305
        for (j = 0; j < v1l->niov; j++) {
171 305
                if (used + v1l->iov[j].iov_len > bytes) {
172
                        /* Cutoff is in this iov */
173 55
                        used_here = bytes - used;
174 55
                        v1l->iov[j].iov_len -= used_here;
175 55
                        v1l->iov[j].iov_base =
176 55
                            (char*)v1l->iov[j].iov_base + used_here;
177 55
                        sz = (unsigned)v1l->niov - (unsigned)j;
178 55
                        sz *= sizeof(struct iovec);
179 55
                        memmove(v1l->iov, &v1l->iov[j], sz);
180 55
                        v1l->niov -= j;
181 55
                        assert(v1l->liov >= bytes);
182 55
                        v1l->liov -= bytes;
183 55
                        return;
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                }
185 250
                used += v1l->iov[j].iov_len;
186 250
        }
187 0
        AZ(v1l->liov);
188 55
}
189
190
stream_close_t
191 51383
V1L_Flush(struct v1l *v1l)
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{
193
        ssize_t i;
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        size_t sz;
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        int err;
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        char cbuf[32];
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198 51383
        CHECK_OBJ_NOTNULL(v1l, V1L_MAGIC);
199 51383
        CHECK_OBJ_NOTNULL(v1l->werr, STREAM_CLOSE_MAGIC);
200 51383
        AN(v1l->wfd);
201
202 51383
        assert(v1l->niov <= v1l->siov);
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204 51383
        if (*v1l->wfd >= 0 && v1l->liov > 0 && v1l->werr == SC_NULL) {
205 34637
                if (v1l->ciov < v1l->siov && v1l->cliov > 0) {
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                        /* Add chunk head & tail */
207 5339
                        bprintf(cbuf, "00%zx\r\n", v1l->cliov);
208 5339
                        sz = strlen(cbuf);
209 5339
                        v1l->iov[v1l->ciov].iov_base = cbuf;
210 5339
                        v1l->iov[v1l->ciov].iov_len = sz;
211 5339
                        v1l->liov += sz;
212
213
                        /* This is OK, because siov was --'ed */
214 5339
                        v1l->iov[v1l->niov].iov_base = cbuf + sz - 2;
215 5339
                        v1l->iov[v1l->niov++].iov_len = 2;
216 5339
                        v1l->liov += 2;
217 34637
                } else if (v1l->ciov < v1l->siov) {
218 314
                        v1l->iov[v1l->ciov].iov_base = cbuf;
219 314
                        v1l->iov[v1l->ciov].iov_len = 0;
220 314
                }
221
222 34637
                i = 0;
223 34637
                err = 0;
224 34637
                do {
225 34829
                        if (VTIM_real() > v1l->deadline) {
226 40
                                VSLb(v1l->vsl, SLT_Debug,
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                                    "Hit total send timeout, "
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                                    "wrote = %zd/%zd; not retrying",
229 20
                                    i, v1l->liov);
230 20
                                i = -1;
231 20
                                break;
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                        }
233
234 34809
                        i = writev(*v1l->wfd, v1l->iov, v1l->niov);
235 34809
                        if (i > 0) {
236 34634
                                v1l->cnt += (size_t)i;
237 34634
                                if ((size_t)i == v1l->liov)
238 34579
                                        break;
239 55
                        }
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                        /* we hit a timeout, and some data may have been sent:
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                         * Remove sent data from start of I/O vector, then retry
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                         *
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                         * XXX: Add a "minimum sent data per timeout counter to
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                         * prevent slowloris attacks
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                         */
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248 230
                        err = errno;
249
250 230
                        if (err == EWOULDBLOCK) {
251 270
                                VSLb(v1l->vsl, SLT_Debug,
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                                    "Hit idle send timeout, "
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                                    "wrote = %zd/%zd; retrying",
254 135
                                    i, v1l->liov);
255 135
                        }
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257 230
                        if (i > 0)
258 55
                                v1l_prune(v1l, i);
259 230
                } while (i > 0 || err == EWOULDBLOCK);
260
261 34637
                if (i <= 0) {
262 120
                        VSLb(v1l->vsl, SLT_Debug,
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                            "Write error, retval = %zd, len = %zd, errno = %s",
264 60
                            i, v1l->liov, VAS_errtxt(err));
265 60
                        assert(v1l->werr == SC_NULL);
266 60
                        if (err == EPIPE)
267 39
                                v1l->werr = SC_REM_CLOSE;
268
                        else
269 21
                                v1l->werr = SC_TX_ERROR;
270 60
                        errno = err;
271 60
                }
272 34637
        }
273 51389
        v1l->liov = 0;
274 51389
        v1l->cliov = 0;
275 51389
        v1l->niov = 0;
276 51389
        if (v1l->ciov < v1l->siov)
277 10371
                v1l->ciov = v1l->niov++;
278 51377
        CHECK_OBJ_NOTNULL(v1l->werr, STREAM_CLOSE_MAGIC);
279 51377
        return (v1l->werr);
280
}
281
282
size_t
283 572836
V1L_Write(struct v1l *v1l, const void *ptr, ssize_t alen)
284
{
285 572836
        size_t len = 0;
286
287 572836
        CHECK_OBJ_NOTNULL(v1l, V1L_MAGIC);
288 572836
        AN(v1l->wfd);
289 572836
        if (alen == 0 || *v1l->wfd < 0)
290 158
                return (0);
291 572836
        if (alen > 0)
292 282176
                len = (size_t)alen;
293 290660
        else if (alen == -1)
294 290660
                len = strlen(ptr);
295
        else
296 0
                WRONG("alen");
297
298 572836
        assert(v1l->niov < v1l->siov);
299 572836
        v1l->iov[v1l->niov].iov_base = TRUST_ME(ptr);
300 572836
        v1l->iov[v1l->niov].iov_len = len;
301 572836
        v1l->liov += len;
302 572836
        v1l->niov++;
303 572836
        v1l->cliov += len;
304 572836
        if (v1l->niov >= v1l->siov) {
305 550
                (void)V1L_Flush(v1l);
306 550
                VSC_C_main->http1_iovs_flush++;
307 550
        }
308 572836
        return (len);
309 572836
}
310
311
void
312 1385
V1L_Chunked(struct v1l *v1l)
313
{
314
315 1385
        CHECK_OBJ_NOTNULL(v1l, V1L_MAGIC);
316
317 1385
        assert(v1l->ciov == v1l->siov);
318 1385
        assert(v1l->siov >= 3);
319
        /*
320
         * If there is no space for chunked header, a chunk of data and
321
         * a chunk tail, we might as well flush right away.
322
         */
323 1385
        if (v1l->niov + 3 >= v1l->siov) {
324 0
                (void)V1L_Flush(v1l);
325 0
                VSC_C_main->http1_iovs_flush++;
326 0
        }
327 1385
        v1l->siov--;
328 1385
        v1l->ciov = v1l->niov++;
329 1385
        v1l->cliov = 0;
330 1385
        assert(v1l->ciov < v1l->siov);
331 1385
        assert(v1l->niov < v1l->siov);
332 1385
}
333
334
/*
335
 * XXX: It is not worth the complexity to attempt to get the
336
 * XXX: end of chunk into the V1L_Flush(), because most of the time
337
 * XXX: if not always, that is a no-op anyway, because the calling
338
 * XXX: code already called V1L_Flush() to release local storage.
339
 */
340
341
void
342 1279
V1L_EndChunk(struct v1l *v1l)
343
{
344
345 1279
        CHECK_OBJ_NOTNULL(v1l, V1L_MAGIC);
346
347 1279
        assert(v1l->ciov < v1l->siov);
348 1279
        (void)V1L_Flush(v1l);
349 1279
        v1l->siov++;
350 1279
        v1l->ciov = v1l->siov;
351 1279
        v1l->niov = 0;
352 1279
        v1l->cliov = 0;
353 1279
        (void)V1L_Write(v1l, "0\r\n\r\n", -1);
354 1279
}
355
356
/*--------------------------------------------------------------------
357
 * VDP using V1L
358
 */
359
360
/* remember priv pointer for V1L_Close() to clear */
361
static int v_matchproto_(vdp_init_f)
362 20105
v1l_init(VRT_CTX, struct vdp_ctx *vdc, void **priv)
363
{
364
        struct v1l *v1l;
365
366 20105
        (void) ctx;
367 20105
        (void) vdc;
368 20105
        AN(priv);
369 20105
        CAST_OBJ_NOTNULL(v1l, *priv, V1L_MAGIC);
370
371 20105
        v1l->vdp_priv = priv;
372 20105
        return (0);
373
}
374
375
static int v_matchproto_(vdp_bytes_f)
376 24520
v1l_bytes(struct vdp_ctx *vdc, enum vdp_action act, void **priv,
377
    const void *ptr, ssize_t len)
378
{
379 24520
        size_t wl = 0;
380
381 24520
        CHECK_OBJ_NOTNULL(vdc, VDP_CTX_MAGIC);
382 24520
        AN(priv);
383
384 24520
        AZ(vdc->nxt);           /* always at the bottom of the pile */
385
386 24520
        if (len > 0)
387 17779
                wl = V1L_Write(*priv, ptr, len);
388 24520
        if (act > VDP_NULL && V1L_Flush(*priv) != SC_NULL)
389 59
                return (-1);
390 24461
        if ((size_t)len != wl)
391 0
                return (-1);
392 24461
        return (0);
393 24520
}
394
395
const struct vdp * const VDP_v1l = &(struct vdp){
396
        .name =         "V1B",
397
        .init =         v1l_init,
398
        .bytes =        v1l_bytes,
399
};