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Introduce API for sequential reads/writes (build/dissect) of mbuf chains.

Browse Source 
Reviewed by:	Ian Dowse <iedowse@maths.tcd.ie>,
		Bosko Milekic <bmilekic@technokratis.com>,
		Julian Elischer <julian@elischer.org> and arch@/net@
Obtained from:	smbfs
This commit is contained in:
Boris Popov 2001-02-24 15:44:30 +00:00
parent 33338e7370
commit d8589bd5cb
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=72980
8 changed files with 721 additions and 1 deletions
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3
sys/conf/NOTES
View File

@ -413,6 +413,9 @@ options NETATALKDEBUG #Appletalk debugging
#options NS #Xerox NS protocols
#options NSIP #XNS over IP
# mchain library. It can be either loaded as KLD or compiled into kernel
options LIBMCHAIN
# netgraph(4). Enable the base netgraph code with the NETGRAPH option.
# Individual node types can be enabled with the corresponding option
# listed below; however, this is not strictly necessary as netgraph

1
sys/conf/files
View File

@ -697,6 +697,7 @@ kern/subr_diskslice.c standard
kern/subr_eventhandler.c standard
kern/subr_kobj.c standard
kern/subr_log.c standard
kern/subr_mchain.c optional libmchain
kern/subr_module.c standard
kern/subr_prf.c standard
kern/subr_prof.c standard

1
sys/conf/options
View File

@ -262,6 +262,7 @@ IPSTEALTH
IPX opt_ipx.h
IPXIP opt_ipx.h
IPTUNNEL opt_ipx.h
LIBMCHAIN
NCP opt_ncp.h
NETATALK opt_atalk.h
PPP_BSDCOMP opt_ppp.h

3
sys/i386/conf/NOTES
View File

@ -413,6 +413,9 @@ options NETATALKDEBUG #Appletalk debugging
#options NS #Xerox NS protocols
#options NSIP #XNS over IP
# mchain library. It can be either loaded as KLD or compiled into kernel
options LIBMCHAIN
# netgraph(4). Enable the base netgraph code with the NETGRAPH option.
# Individual node types can be enabled with the corresponding option
# listed below; however, this is not strictly necessary as netgraph

549
sys/kern/subr_mchain.c Normal file
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@ -0,0 +1,549 @@
/*
* Copyright (c) 2000, 2001 Boris Popov
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Boris Popov.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/uio.h>
#include <sys/mchain.h>
MODULE_VERSION(libmchain, 1);
#define MBERROR(format, args...) printf("%s(%d): "format, __FUNCTION__ , \
__LINE__ ,## args)
#define MBPANIC(format, args...) printf("%s(%d): "format, __FUNCTION__ , \
__LINE__ ,## args)
/*
* Various helper functions
*/
int
m_fixhdr(struct mbuf *m0)
{
struct mbuf *m = m0;
int len = 0;
while (m) {
len += m->m_len;
m = m->m_next;
}
m0->m_pkthdr.len = len;
return len;
}
int
mb_init(struct mbchain *mbp)
{
struct mbuf *m;
m = m_gethdr(M_TRYWAIT, MT_DATA);
if (m == NULL)
return ENOBUFS;
m->m_pkthdr.rcvif = NULL;
m->m_len = 0;
mb_initm(mbp, m);
return 0;
}
void
mb_initm(struct mbchain *mbp, struct mbuf *m)
{
bzero(mbp, sizeof(*mbp));
mbp->mb_top = mbp->mb_cur = m;
mbp->mb_mleft = M_TRAILINGSPACE(m);
}
void
mb_done(struct mbchain *mbp)
{
if (mbp->mb_top) {
m_freem(mbp->mb_top);
mbp->mb_top = NULL;
}
}
struct mbuf *
mb_detach(struct mbchain *mbp)
{
struct mbuf *m;
m = mbp->mb_top;
mbp->mb_top = NULL;
return m;
}
int
mb_fixhdr(struct mbchain *mbp)
{
return mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top);
}
/*
* Check if object of size 'size' fit to the current position and
* allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
* Return pointer to the object placeholder or NULL if any error occured.
* Note: size should be <= MLEN
*/
caddr_t
mb_reserve(struct mbchain *mbp, int size)
{
struct mbuf *m, *mn;
caddr_t bpos;
if (size > MLEN)
panic("mb_reserve: size = %d\n", size);
m = mbp->mb_cur;
if (mbp->mb_mleft < size) {
mn = m_get(M_TRYWAIT, MT_DATA);
if (mn == NULL)
return NULL;
mbp->mb_cur = m->m_next = mn;
m = mn;
m->m_len = 0;
mbp->mb_mleft = M_TRAILINGSPACE(m);
}
mbp->mb_mleft -= size;
mbp->mb_count += size;
bpos = mtod(m, caddr_t) + m->m_len;
m->m_len += size;
return bpos;
}
int
mb_put_uint8(struct mbchain *mbp, u_int8_t x)
{
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint16be(struct mbchain *mbp, u_int16_t x)
{
x = htobes(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint16le(struct mbchain *mbp, u_int16_t x)
{
x = htoles(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint32be(struct mbchain *mbp, u_int32_t x)
{
x = htobel(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint32le(struct mbchain *mbp, u_int32_t x)
{
x = htolel(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_int64be(struct mbchain *mbp, int64_t x)
{
x = htobeq(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_int64le(struct mbchain *mbp, int64_t x)
{
x = htoleq(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
{
struct mbuf *m;
caddr_t dst;
c_caddr_t src;
int cplen, error, mleft, count;
m = mbp->mb_cur;
mleft = mbp->mb_mleft;
while (size > 0) {
if (mleft == 0) {
if (m->m_next == NULL) {
m = m_getm(m, size, M_TRYWAIT, MT_DATA);
if (m == NULL)
return ENOBUFS;
}
m = m->m_next;
mleft = M_TRAILINGSPACE(m);
continue;
}
cplen = mleft > size ? size : mleft;
dst = mtod(m, caddr_t) + m->m_len;
switch (type) {
case MB_MCUSTOM:
error = mbp->mb_copy(mbp, source, dst, cplen);
if (error)
return error;
break;
case MB_MINLINE:
for (src = source, count = cplen; count; count--)
*dst++ = *src++;
break;
case MB_MSYSTEM:
bcopy(source, dst, cplen);
break;
case MB_MUSER:
error = copyin(source, dst, cplen);
if (error)
return error;
break;
case MB_MZERO:
bzero(dst, cplen);
break;
}
size -= cplen;
source += cplen;
m->m_len += cplen;
mleft -= cplen;
mbp->mb_count += cplen;
}
mbp->mb_cur = m;
mbp->mb_mleft = mleft;
return 0;
}
int
mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
{
mbp->mb_cur->m_next = m;
while (m) {
mbp->mb_count += m->m_len;
if (m->m_next == NULL)
break;
m = m->m_next;
}
mbp->mb_mleft = M_TRAILINGSPACE(m);
mbp->mb_cur = m;
return 0;
}
/*
* copies a uio scatter/gather list to an mbuf chain.
* NOTE: can ony handle iovcnt == 1
*/
int
mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
{
long left;
int mtype, error;
#ifdef DIAGNOSTIC
if (uiop->uio_iovcnt != 1)
MBPANIC("iovcnt != 1");
#endif
mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
while (size > 0) {
left = uiop->uio_iov->iov_len;
if (left > size)
left = size;
error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
if (error)
return error;
uiop->uio_offset += left;
uiop->uio_resid -= left;
uiop->uio_iov->iov_base += left;
uiop->uio_iov->iov_len -= left;
size -= left;
}
return 0;
}
/*
* Routines for fetching data from an mbuf chain
*/
int
md_init(struct mdchain *mdp)
{
struct mbuf *m;
m = m_gethdr(M_TRYWAIT, MT_DATA);
if (m == NULL)
return ENOBUFS;
m->m_pkthdr.rcvif = NULL;
m->m_len = 0;
md_initm(mdp, m);
return 0;
}
void
md_initm(struct mdchain *mdp, struct mbuf *m)
{
bzero(mdp, sizeof(*mdp));
mdp->md_top = mdp->md_cur = m;
mdp->md_pos = mtod(m, u_char*);
}
void
md_done(struct mdchain *mdp)
{
if (mdp->md_top) {
m_freem(mdp->md_top);
mdp->md_top = NULL;
}
}
/*
* Append a separate mbuf chain. It is caller responsibility to prevent
* multiple calls to fetch/record routines.
*/
void
md_append_record(struct mdchain *mdp, struct mbuf *top)
{
struct mbuf *m;
if (mdp->md_top == NULL) {
md_initm(mdp, top);
return;
}
m = mdp->md_top;
while (m->m_nextpkt)
m = m->m_nextpkt;
m->m_nextpkt = top;
top->m_nextpkt = NULL;
return;
}
/*
* Put next record in place of existing
*/
int
md_next_record(struct mdchain *mdp)
{
struct mbuf *m;
if (mdp->md_top == NULL)
return ENOENT;
m = mdp->md_top->m_nextpkt;
md_done(mdp);
if (m == NULL)
return ENOENT;
md_initm(mdp, m);
return 0;
}
int
md_get_uint8(struct mdchain *mdp, u_int8_t *x)
{
return md_get_mem(mdp, x, 1, MB_MINLINE);
}
int
md_get_uint16(struct mdchain *mdp, u_int16_t *x)
{
return md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE);
}
int
md_get_uint16le(struct mdchain *mdp, u_int16_t *x)
{
u_int16_t v;
int error = md_get_uint16(mdp, &v);
*x = letohs(v);
return error;
}
int
md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
u_int16_t v;
int error = md_get_uint16(mdp, &v);
*x = betohs(v);
return error;
}
int
md_get_uint32(struct mdchain *mdp, u_int32_t *x)
{
return md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE);
}
int
md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
{
u_int32_t v;
int error;
error = md_get_uint32(mdp, &v);
*x = betohl(v);
return error;
}
int
md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
{
u_int32_t v;
int error;
error = md_get_uint32(mdp, &v);
*x = letohl(v);
return error;
}
int
md_get_int64(struct mdchain *mdp, int64_t *x)
{
return md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE);
}
int
md_get_int64be(struct mdchain *mdp, int64_t *x)
{
int64_t v;
int error;
error = md_get_int64(mdp, &v);
*x = betohq(v);
return error;
}
int
md_get_int64le(struct mdchain *mdp, int64_t *x)
{
int64_t v;
int error;
error = md_get_int64(mdp, &v);
*x = letohq(v);
return error;
}
int
md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
{
struct mbuf *m = mdp->md_cur;
int error;
u_int count;
u_char *s;
while (size > 0) {
if (m == NULL) {
MBERROR("incomplete copy\n");
return EBADRPC;
}
s = mdp->md_pos;
count = mtod(m, u_char*) + m->m_len - s;
if (count == 0) {
mdp->md_cur = m = m->m_next;
if (m)
s = mdp->md_pos = mtod(m, caddr_t);
continue;
}
if (count > size)
count = size;
size -= count;
mdp->md_pos += count;
if (target == NULL)
continue;
switch (type) {
case MB_MUSER:
error = copyout(s, target, count);
if (error)
return error;
break;
case MB_MSYSTEM:
bcopy(s, target, count);
break;
case MB_MINLINE:
while (count--)
*target++ = *s++;
continue;
}
target += count;
}
return 0;
}
int
md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
{
struct mbuf *m = mdp->md_cur, *rm;
rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_TRYWAIT);
if (rm == NULL)
return EBADRPC;
md_get_mem(mdp, NULL, size, MB_MZERO);
*ret = rm;
return 0;
}
int
md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
{
char *uiocp;
long left;
int mtype, error;
mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
while (size > 0) {
if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
return EFBIG;
left = uiop->uio_iov->iov_len;
uiocp = uiop->uio_iov->iov_base;
if (left > size)
left = size;
error = md_get_mem(mdp, uiocp, left, mtype);
if (error)
return error;
uiop->uio_offset += left;
uiop->uio_resid -= left;
if (uiop->uio_iov->iov_len <= size) {
uiop->uio_iovcnt--;
uiop->uio_iov++;
} else {
uiop->uio_iov->iov_base += left;
uiop->uio_iov->iov_len -= left;
}
size -= left;
}
return 0;
}

2
sys/modules/Makefile
View File

@ -9,7 +9,7 @@ _random= random
SUBDIR= 3dfx accf_data accf_http agp aha amr an aue \
cam ccd cd9660 coda cue dc de ed fdesc fxp if_disc if_ef \
if_ppp if_sl if_tap if_tun ip6fw ipfilter ipfw ispfw joy kue \
linux lnc md mfs mii mlx msdos ncp netgraph nfs ntfs nullfs \
libmchain linux lnc md mfs mii mlx msdos ncp netgraph nfs ntfs nullfs \
nwfs pcn portal procfs ${_random} \
rl rp sf sis sk sn sound sppp ste sym syscons sysvipc ti tl twe tx \
udbp ugen uhid ukbd ulpt umapfs umass umodem ums union urio usb \

8
sys/modules/libmchain/Makefile Normal file
View File

@ -0,0 +1,8 @@
# $FreeBSD$
.PATH: ${.CURDIR}/../../kern
KMOD= libmchain
SRCS= subr_mchain.c
.include <bsd.kmod.mk>

155
sys/sys/mchain.h Normal file
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@ -0,0 +1,155 @@
/*
* Copyright (c) 2000, 2001 Boris Popov
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Boris Popov.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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.
*
* $FreeBSD$
*/
#ifndef _SYS_MCHAIN_H_
#define _SYS_MCHAIN_H_
#include <machine/endian.h>
/*
* This macros probably belongs to the endian.h
*/
#if (BYTE_ORDER == LITTLE_ENDIAN)
#define htoles(x) ((u_int16_t)(x))
#define letohs(x) ((u_int16_t)(x))
#define htolel(x) ((u_int32_t)(x))
#define letohl(x) ((u_int32_t)(x))
#define htoleq(x) ((int64_t)(x))
#define letohq(x) ((int64_t)(x))
#define htobes(x) (htons(x))
#define betohs(x) (ntohs(x))
#define htobel(x) (htonl(x))
#define betohl(x) (ntohl(x))
static __inline int64_t
htobeq(int64_t x)
{
return (int64_t)htonl((u_int32_t)(x >> 32)) |
(int64_t)htonl((u_int32_t)(x & 0xffffffff)) << 32;
}
static __inline int64_t
betohq(int64_t x)
{
return (int64_t)ntohl((u_int32_t)(x >> 32)) |
(int64_t)ntohl((u_int32_t)(x & 0xffffffff)) << 32;
}
#else /* (BYTE_ORDER == LITTLE_ENDIAN) */
#error "Macros for Big-Endians are incomplete"
/*
#define htoles(x) ((u_int16_t)(x))
#define letohs(x) ((u_int16_t)(x))
#define htolel(x) ((u_int32_t)(x))
#define letohl(x) ((u_int32_t)(x))
*/
#endif /* (BYTE_ORDER == LITTLE_ENDIAN) */
#ifdef _KERNEL
/*
* Type of copy for mb_{put|get}_mem()
*/
#define MB_MSYSTEM 0 /* use bcopy() */
#define MB_MUSER 1 /* use copyin()/copyout() */
#define MB_MINLINE 2 /* use an inline copy loop */
#define MB_MZERO 3 /* bzero(), mb_put_mem only */
#define MB_MCUSTOM 4 /* use an user defined function */
struct mbuf;
struct mbchain;
typedef int mb_copy_t(struct mbchain *mbp, c_caddr_t src, caddr_t dst, int len);
struct mbchain {
struct mbuf * mb_top; /* head of mbufs chain */
struct mbuf * mb_cur; /* current mbuf */
int mb_mleft; /* free space in the current mbuf */
int mb_count; /* total number of bytes */
mb_copy_t * mb_copy; /* user defined copy function */
void * mb_udata; /* user data */
};
struct mdchain {
struct mbuf * md_top; /* head of mbufs chain */
struct mbuf * md_cur; /* current mbuf */
u_char * md_pos; /* offset in the current mbuf */
};
int m_fixhdr(struct mbuf *m);
int mb_init(struct mbchain *mbp);
void mb_initm(struct mbchain *mbp, struct mbuf *m);
void mb_done(struct mbchain *mbp);
struct mbuf *mb_detach(struct mbchain *mbp);
int mb_fixhdr(struct mbchain *mbp);
caddr_t mb_reserve(struct mbchain *mbp, int size);
int mb_put_uint8(struct mbchain *mbp, u_int8_t x);
int mb_put_uint16be(struct mbchain *mbp, u_int16_t x);
int mb_put_uint16le(struct mbchain *mbp, u_int16_t x);
int mb_put_uint32be(struct mbchain *mbp, u_int32_t x);
int mb_put_uint32le(struct mbchain *mbp, u_int32_t x);
int mb_put_int64be(struct mbchain *mbp, int64_t x);
int mb_put_int64le(struct mbchain *mbp, int64_t x);
int mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type);
int mb_put_mbuf(struct mbchain *mbp, struct mbuf *m);
int mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size);
int md_init(struct mdchain *mdp);
void md_initm(struct mdchain *mbp, struct mbuf *m);
void md_done(struct mdchain *mdp);
void md_append_record(struct mdchain *mdp, struct mbuf *top);
int md_next_record(struct mdchain *mdp);
int md_get_uint8(struct mdchain *mdp, u_int8_t *x);
int md_get_uint16(struct mdchain *mdp, u_int16_t *x);
int md_get_uint16le(struct mdchain *mdp, u_int16_t *x);
int md_get_uint16be(struct mdchain *mdp, u_int16_t *x);
int md_get_uint32(struct mdchain *mdp, u_int32_t *x);
int md_get_uint32be(struct mdchain *mdp, u_int32_t *x);
int md_get_uint32le(struct mdchain *mdp, u_int32_t *x);
int md_get_int64(struct mdchain *mdp, int64_t *x);
int md_get_int64be(struct mdchain *mdp, int64_t *x);
int md_get_int64le(struct mdchain *mdp, int64_t *x);
int md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type);
int md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **m);
int md_get_uio(struct mdchain *mdp, struct uio *uiop, int size);
#endif /* ifdef _KERNEL */
#endif /* !_SYS_MCHAIN_H_ */