NetBSD-5.0.2/sys/netinet/accf_http.c
/* $NetBSD: accf_http.c,v 1.2 2008/10/14 13:05:44 ad Exp $ */
/*-
* Copyright (c) 2000 Paycounter, Inc.
* Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: accf_http.c,v 1.2 2008/10/14 13:05:44 ad Exp $");
#define ACCEPT_FILTER_MOD
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/lkm.h>
#include <sys/signalvar.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <netinet/accept_filter.h>
/* check for GET/HEAD */
static void sohashttpget(struct socket *so, void *arg, int waitflag);
/* check for HTTP/1.0 or HTTP/1.1 */
static void soparsehttpvers(struct socket *so, void *arg, int waitflag);
/* check for end of HTTP/1.x request */
static void soishttpconnected(struct socket *so, void *arg, int waitflag);
/* strcmp on an mbuf chain */
static int mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, const char *cmp);
/* strncmp on an mbuf chain */
static int mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset,
int len, const char *cmp);
/* socketbuffer is full */
static int sbfull(struct sockbuf *sb);
static struct accept_filter accf_http_filter = {
.accf_name = "httpready",
.accf_callback = sohashttpget,
};
/*
* Names of HTTP Accept filter sysctl objects
*/
#define ACCFCTL_PARSEVER 1 /* Parse HTTP version */
static int parse_http_version = 1;
SYSCTL_SETUP(sysctl_net_inet_accf__http_setup, "sysctl net.inet.accf.http subtree setup")
{
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "net", NULL,
NULL, 0, NULL, 0,
CTL_NET, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "inet", NULL,
NULL, 0, NULL, 0,
CTL_NET, PF_INET, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "accf", NULL,
NULL, 0, NULL, 0,
CTL_NET, PF_INET, SO_ACCEPTFILTER, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "http",
SYSCTL_DESCR("HTTP accept filter"),
NULL, 0, NULL, 0,
CTL_NET, PF_INET, SO_ACCEPTFILTER, ACCF_HTTP, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT, "parsehttpversion",
SYSCTL_DESCR("Parse http version so that non "
"1.x requests work"),
NULL, 0, &parse_http_version, 0,
CTL_NET, PF_INET, SO_ACCEPTFILTER, ACCF_HTTP,
ACCFCTL_PARSEVER, CTL_EOL);
}
void accf_httpattach(int);
void accf_httpattach(int num)
{
accept_filt_generic_mod_event(NULL, LKM_E_LOAD, &accf_http_filter);
}
/*
* This code is to make HTTP ready accept filer as LKM.
* To compile as LKM we need to move this set of code into
* another file and include this file for compilation when
* making LKM
*/
#ifdef _LKM
static int accf_http_handle(struct lkm_table * lkmtp, int cmd);
int accf_http_lkmentry(struct lkm_table * lkmtp, int cmd, int ver);
MOD_MISC("accf_http");
static int accf_http_handle(struct lkm_table * lkmtp, int cmd)
{
return accept_filt_generic_mod_event(lkmtp, cmd, &accf_http_filter);
}
/*
* the module entry point.
*/
int
accf_http_lkmentry(struct lkm_table *lkmtp, int cmd, int ver)
{
DISPATCH(lkmtp, cmd, ver, accf_http_handle, accf_http_handle,
accf_http_handle)
}
#endif
#ifdef ACCF_HTTP_DEBUG
#define DPRINT(fmt, args...) \
do { \
printf("%s:%d: " fmt "\n", __func__, __LINE__, ##args); \
} while (0)
#else
#define DPRINT(fmt, args...)
#endif
static int
sbfull(struct sockbuf *sb)
{
DPRINT("sbfull, cc(%ld) >= hiwat(%ld): %d, "
"mbcnt(%ld) >= mbmax(%ld): %d",
sb->sb_cc, sb->sb_hiwat, sb->sb_cc >= sb->sb_hiwat,
sb->sb_mbcnt, sb->sb_mbmax, sb->sb_mbcnt >= sb->sb_mbmax);
return (sb->sb_cc >= sb->sb_hiwat || sb->sb_mbcnt >= sb->sb_mbmax);
}
/*
* start at mbuf m, (must provide npkt if exists)
* starting at offset in m compare characters in mbuf chain for 'cmp'
*/
static int
mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, const char *cmp)
{
struct mbuf *n;
for (; m != NULL; m = n) {
n = npkt;
if (npkt)
npkt = npkt->m_nextpkt;
for (; m; m = m->m_next) {
for (; offset < m->m_len; offset++, cmp++) {
if (*cmp == '\0')
return (1);
else if (*cmp != *(mtod(m, char *) + offset))
return (0);
}
if (*cmp == '\0')
return (1);
offset = 0;
}
}
return (0);
}
/*
* start at mbuf m, (must provide npkt if exists)
* starting at offset in m compare characters in mbuf chain for 'cmp'
* stop at 'max' characters
*/
static int
mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, int len, const char *cmp)
{
struct mbuf *n;
for (; m != NULL; m = n) {
n = npkt;
if (npkt)
npkt = npkt->m_nextpkt;
for (; m; m = m->m_next) {
for (; offset < m->m_len; offset++, cmp++, len--) {
if (len == 0 || *cmp == '\0')
return (1);
else if (*cmp != *(mtod(m, char *) + offset))
return (0);
}
if (len == 0 || *cmp == '\0')
return (1);
offset = 0;
}
}
return (0);
}
#define STRSETUP(sptr, slen, str) \
do { \
sptr = str; \
slen = sizeof(str) - 1; \
} while(0)
static void
sohashttpget(struct socket *so, void *arg, int waitflag)
{
if ((so->so_state & SS_CANTRCVMORE) == 0 && !sbfull(&so->so_rcv)) {
struct mbuf *m;
const char *cmp;
int cmplen, cc;
m = so->so_rcv.sb_mb;
cc = so->so_rcv.sb_cc - 1;
if (cc < 1)
return;
switch (*mtod(m, char *)) {
case 'G':
STRSETUP(cmp, cmplen, "ET ");
break;
case 'H':
STRSETUP(cmp, cmplen, "EAD ");
break;
default:
goto fallout;
}
if (cc < cmplen) {
if (mbufstrncmp(m, m->m_nextpkt, 1, cc, cmp) == 1) {
DPRINT("short cc (%d) but mbufstrncmp ok", cc);
return;
} else {
DPRINT("short cc (%d) mbufstrncmp failed", cc);
goto fallout;
}
}
if (mbufstrcmp(m, m->m_nextpkt, 1, cmp) == 1) {
DPRINT("mbufstrcmp ok");
if (parse_http_version == 0)
soishttpconnected(so, arg, waitflag);
else
soparsehttpvers(so, arg, waitflag);
return;
}
DPRINT("mbufstrcmp bad");
}
fallout:
DPRINT("fallout");
so->so_upcall = NULL;
so->so_rcv.sb_flags &= ~SB_UPCALL;
soisconnected(so);
return;
}
static void
soparsehttpvers(struct socket *so, void *arg, int waitflag)
{
struct mbuf *m, *n;
int i, cc, spaces, inspaces;
if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv))
goto fallout;
m = so->so_rcv.sb_mb;
cc = so->so_rcv.sb_cc;
inspaces = spaces = 0;
for (m = so->so_rcv.sb_mb; m; m = n) {
n = m->m_nextpkt;
for (; m; m = m->m_next) {
for (i = 0; i < m->m_len; i++, cc--) {
switch (*(mtod(m, char *) + i)) {
case ' ':
/* tabs? '\t' */
if (!inspaces) {
spaces++;
inspaces = 1;
}
break;
case '\r':
case '\n':
DPRINT("newline");
goto fallout;
default:
if (spaces != 2) {
inspaces = 0;
break;
}
/*
* if we don't have enough characters
* left (cc < sizeof("HTTP/1.0") - 1)
* then see if the remaining ones
* are a request we can parse.
*/
if (cc < sizeof("HTTP/1.0") - 1) {
if (mbufstrncmp(m, n, i, cc,
"HTTP/1.") == 1) {
DPRINT("ok");
goto readmore;
} else {
DPRINT("bad");
goto fallout;
}
} else if (
mbufstrcmp(m, n, i, "HTTP/1.0") ||
mbufstrcmp(m, n, i, "HTTP/1.1")) {
DPRINT("ok");
soishttpconnected(so,
arg, waitflag);
return;
} else {
DPRINT("bad");
goto fallout;
}
}
}
}
}
readmore:
DPRINT("readmore");
/*
* if we hit here we haven't hit something
* we don't understand or a newline, so try again
*/
so->so_upcall = soparsehttpvers;
so->so_rcv.sb_flags |= SB_UPCALL;
return;
fallout:
DPRINT("fallout");
so->so_upcall = NULL;
so->so_rcv.sb_flags &= ~SB_UPCALL;
soisconnected(so);
return;
}
#define NCHRS 3
static void
soishttpconnected(struct socket *so, void *arg, int waitflag)
{
char a, b, c;
struct mbuf *m, *n;
int ccleft, copied;
DPRINT("start");
if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv))
goto gotit;
/*
* Walk the socketbuffer and copy the last NCHRS (3) into a, b, and c
* copied - how much we've copied so far
* ccleft - how many bytes remaining in the socketbuffer
* just loop over the mbufs subtracting from 'ccleft' until we only
* have NCHRS left
*/
copied = 0;
ccleft = so->so_rcv.sb_cc;
if (ccleft < NCHRS)
goto readmore;
a = b = c = '\0';
for (m = so->so_rcv.sb_mb; m; m = n) {
n = m->m_nextpkt;
for (; m; m = m->m_next) {
ccleft -= m->m_len;
if (ccleft <= NCHRS) {
char *src;
int tocopy;
tocopy = (NCHRS - ccleft) - copied;
src = mtod(m, char *) + (m->m_len - tocopy);
while (tocopy--) {
switch (copied++) {
case 0:
a = *src++;
break;
case 1:
b = *src++;
break;
case 2:
c = *src++;
break;
}
}
}
}
}
if (c == '\n' && (b == '\n' || (b == '\r' && a == '\n'))) {
/* we have all request headers */
goto gotit;
}
readmore:
so->so_upcall = soishttpconnected;
so->so_rcv.sb_flags |= SB_UPCALL;
return;
gotit:
so->so_upcall = NULL;
so->so_rcv.sb_flags &= ~SB_UPCALL;
soisconnected(so);
return;
}