340 lines
8.3 KiB
C
340 lines
8.3 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2000 Paycounter, Inc.
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* Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org>
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* All rights reserved.
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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 THE 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#define ACCEPT_FILTER_MOD
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/mbuf.h>
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#include <sys/module.h>
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#include <sys/signalvar.h>
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#include <sys/sysctl.h>
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#include <sys/socketvar.h>
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/* check for GET/HEAD */
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static int sohashttpget(struct socket *so, void *arg, int waitflag);
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/* check for HTTP/1.0 or HTTP/1.1 */
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static int soparsehttpvers(struct socket *so, void *arg, int waitflag);
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/* check for end of HTTP/1.x request */
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static int soishttpconnected(struct socket *so, void *arg, int waitflag);
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/* strcmp on an mbuf chain */
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static int mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, char *cmp);
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/* strncmp on an mbuf chain */
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static int mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset,
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int max, char *cmp);
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/* socketbuffer is full */
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static int sbfull(struct sockbuf *sb);
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ACCEPT_FILTER_DEFINE(accf_http, "httpready", sohashttpget, NULL, NULL, 1);
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static int parse_http_version = 1;
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static SYSCTL_NODE(_net_inet_accf, OID_AUTO, http,
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CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
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"HTTP accept filter");
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SYSCTL_INT(_net_inet_accf_http, OID_AUTO, parsehttpversion, CTLFLAG_RW,
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&parse_http_version, 1,
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"Parse http version so that non 1.x requests work");
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#ifdef ACCF_HTTP_DEBUG
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#define DPRINT(fmt, args...) \
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do { \
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printf("%s:%d: " fmt "\n", __func__, __LINE__, ##args); \
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} while (0)
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#else
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#define DPRINT(fmt, args...)
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#endif
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static int
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sbfull(struct sockbuf *sb)
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{
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DPRINT("sbfull, cc(%ld) >= hiwat(%ld): %d, "
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"mbcnt(%ld) >= mbmax(%ld): %d",
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sb->sb_cc, sb->sb_hiwat, sb->sb_cc >= sb->sb_hiwat,
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sb->sb_mbcnt, sb->sb_mbmax, sb->sb_mbcnt >= sb->sb_mbmax);
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return (sbused(sb) >= sb->sb_hiwat || sb->sb_mbcnt >= sb->sb_mbmax);
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}
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/*
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* start at mbuf m, (must provide npkt if exists)
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* starting at offset in m compare characters in mbuf chain for 'cmp'
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*/
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static int
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mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, char *cmp)
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{
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struct mbuf *n;
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for (; m != NULL; m = n) {
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n = npkt;
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if (npkt)
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npkt = npkt->m_nextpkt;
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for (; m; m = m->m_next) {
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for (; offset < m->m_len; offset++, cmp++) {
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if (*cmp == '\0')
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return (1);
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else if (*cmp != *(mtod(m, char *) + offset))
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return (0);
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}
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if (*cmp == '\0')
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return (1);
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offset = 0;
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}
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}
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return (0);
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}
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/*
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* start at mbuf m, (must provide npkt if exists)
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* starting at offset in m compare characters in mbuf chain for 'cmp'
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* stop at 'max' characters
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*/
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static int
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mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, int max, char *cmp)
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{
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struct mbuf *n;
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for (; m != NULL; m = n) {
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n = npkt;
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if (npkt)
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npkt = npkt->m_nextpkt;
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for (; m; m = m->m_next) {
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for (; offset < m->m_len; offset++, cmp++, max--) {
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if (max == 0 || *cmp == '\0')
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return (1);
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else if (*cmp != *(mtod(m, char *) + offset))
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return (0);
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}
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if (max == 0 || *cmp == '\0')
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return (1);
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offset = 0;
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}
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}
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return (0);
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}
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#define STRSETUP(sptr, slen, str) \
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do { \
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sptr = str; \
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slen = sizeof(str) - 1; \
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} while(0)
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static int
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sohashttpget(struct socket *so, void *arg, int waitflag)
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{
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if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 &&
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!sbfull(&so->so_rcv)) {
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struct mbuf *m;
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char *cmp;
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int cmplen, cc;
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m = so->so_rcv.sb_mb;
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cc = sbavail(&so->so_rcv) - 1;
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if (cc < 1)
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return (SU_OK);
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switch (*mtod(m, char *)) {
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case 'G':
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STRSETUP(cmp, cmplen, "ET ");
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break;
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case 'H':
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STRSETUP(cmp, cmplen, "EAD ");
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break;
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default:
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goto fallout;
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}
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if (cc < cmplen) {
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if (mbufstrncmp(m, m->m_nextpkt, 1, cc, cmp) == 1) {
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DPRINT("short cc (%d) but mbufstrncmp ok", cc);
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return (SU_OK);
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} else {
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DPRINT("short cc (%d) mbufstrncmp failed", cc);
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goto fallout;
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}
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}
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if (mbufstrcmp(m, m->m_nextpkt, 1, cmp) == 1) {
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DPRINT("mbufstrcmp ok");
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if (parse_http_version == 0)
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return (soishttpconnected(so, arg, waitflag));
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else
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return (soparsehttpvers(so, arg, waitflag));
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}
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DPRINT("mbufstrcmp bad");
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}
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fallout:
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DPRINT("fallout");
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return (SU_ISCONNECTED);
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}
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static int
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soparsehttpvers(struct socket *so, void *arg, int waitflag)
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{
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struct mbuf *m, *n;
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int i, cc, spaces, inspaces;
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if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv))
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goto fallout;
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m = so->so_rcv.sb_mb;
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cc = sbavail(&so->so_rcv);
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inspaces = spaces = 0;
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for (m = so->so_rcv.sb_mb; m; m = n) {
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n = m->m_nextpkt;
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for (; m; m = m->m_next) {
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for (i = 0; i < m->m_len; i++, cc--) {
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switch (*(mtod(m, char *) + i)) {
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case ' ':
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/* tabs? '\t' */
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if (!inspaces) {
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spaces++;
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inspaces = 1;
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}
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break;
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case '\r':
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case '\n':
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DPRINT("newline");
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goto fallout;
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default:
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if (spaces != 2) {
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inspaces = 0;
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break;
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}
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/*
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* if we don't have enough characters
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* left (cc < sizeof("HTTP/1.0") - 1)
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* then see if the remaining ones
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* are a request we can parse.
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*/
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if (cc < sizeof("HTTP/1.0") - 1) {
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if (mbufstrncmp(m, n, i, cc,
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"HTTP/1.") == 1) {
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DPRINT("ok");
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goto readmore;
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} else {
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DPRINT("bad");
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goto fallout;
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}
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} else if (
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mbufstrcmp(m, n, i, "HTTP/1.0") ||
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mbufstrcmp(m, n, i, "HTTP/1.1")) {
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DPRINT("ok");
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return (soishttpconnected(so,
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arg, waitflag));
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} else {
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DPRINT("bad");
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goto fallout;
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}
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}
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}
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}
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}
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readmore:
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DPRINT("readmore");
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/*
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* if we hit here we haven't hit something
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* we don't understand or a newline, so try again
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*/
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soupcall_set(so, SO_RCV, soparsehttpvers, arg);
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return (SU_OK);
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fallout:
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DPRINT("fallout");
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return (SU_ISCONNECTED);
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}
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#define NCHRS 3
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static int
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soishttpconnected(struct socket *so, void *arg, int waitflag)
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{
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char a, b, c;
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struct mbuf *m, *n;
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int ccleft, copied;
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DPRINT("start");
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if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv))
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goto gotit;
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/*
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* Walk the socketbuffer and copy the last NCHRS (3) into a, b, and c
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* copied - how much we've copied so far
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* ccleft - how many bytes remaining in the socketbuffer
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* just loop over the mbufs subtracting from 'ccleft' until we only
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* have NCHRS left
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*/
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copied = 0;
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ccleft = sbavail(&so->so_rcv);
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if (ccleft < NCHRS)
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goto readmore;
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a = b = c = '\0';
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for (m = so->so_rcv.sb_mb; m; m = n) {
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n = m->m_nextpkt;
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for (; m; m = m->m_next) {
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ccleft -= m->m_len;
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if (ccleft <= NCHRS) {
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char *src;
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int tocopy;
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tocopy = (NCHRS - ccleft) - copied;
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src = mtod(m, char *) + (m->m_len - tocopy);
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while (tocopy--) {
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switch (copied++) {
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case 0:
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a = *src++;
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break;
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case 1:
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b = *src++;
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break;
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case 2:
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c = *src++;
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break;
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}
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}
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}
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}
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}
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if (c == '\n' && (b == '\n' || (b == '\r' && a == '\n'))) {
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/* we have all request headers */
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goto gotit;
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}
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readmore:
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soupcall_set(so, SO_RCV, soishttpconnected, arg);
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return (SU_OK);
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gotit:
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return (SU_ISCONNECTED);
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}
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