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mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
freebsd/sys/nfs/nfs_common.c
2013-03-15 10:21:18 +00:00

408 lines
9.6 KiB
C

/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)nfs_subs.c 8.8 (Berkeley) 5/22/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* These functions support the macros and help fiddle mbuf chains for
* the nfs op functions. They do things like create the rpc header and
* copy data between mbuf chains and uio lists.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sysent.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <nfs/nfsproto.h>
#include <nfsserver/nfs.h>
#include <nfs/xdr_subs.h>
#include <nfs/nfs_common.h>
#include <netinet/in.h>
enum vtype nv3tov_type[8]= {
VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO
};
nfstype nfsv3_type[9] = {
NFNON, NFREG, NFDIR, NFBLK, NFCHR, NFLNK, NFSOCK, NFFIFO, NFNON
};
static void *nfsm_dissect_xx_sub(int s, struct mbuf **md, caddr_t *dpos,
int how);
SYSCTL_NODE(_vfs, OID_AUTO, nfs_common, CTLFLAG_RD, 0, "NFS common support");
static int nfs_realign_test;
SYSCTL_INT(_vfs_nfs_common, OID_AUTO, realign_test, CTLFLAG_RD,
&nfs_realign_test, 0, "Number of realign tests done");
static int nfs_realign_count;
SYSCTL_INT(_vfs_nfs_common, OID_AUTO, realign_count, CTLFLAG_RD,
&nfs_realign_count, 0, "Number of mbuf realignments done");
/*
* copies mbuf chain to the uio scatter/gather list
*/
int
nfsm_mbuftouio(struct mbuf **mrep, struct uio *uiop, int siz, caddr_t *dpos)
{
char *mbufcp, *uiocp;
int xfer, left, len;
struct mbuf *mp;
long uiosiz, rem;
int error = 0;
mp = *mrep;
mbufcp = *dpos;
len = mtod(mp, caddr_t)+mp->m_len-mbufcp;
rem = nfsm_rndup(siz)-siz;
while (siz > 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 > siz)
left = siz;
uiosiz = left;
while (left > 0) {
while (len == 0) {
mp = mp->m_next;
if (mp == NULL)
return (EBADRPC);
mbufcp = mtod(mp, caddr_t);
len = mp->m_len;
}
xfer = (left > len) ? len : left;
#ifdef notdef
/* Not Yet.. */
if (uiop->uio_iov->iov_op != NULL)
(*(uiop->uio_iov->iov_op))
(mbufcp, uiocp, xfer);
else
#endif
if (uiop->uio_segflg == UIO_SYSSPACE)
bcopy(mbufcp, uiocp, xfer);
else
copyout(mbufcp, uiocp, xfer);
left -= xfer;
len -= xfer;
mbufcp += xfer;
uiocp += xfer;
uiop->uio_offset += xfer;
uiop->uio_resid -= xfer;
}
if (uiop->uio_iov->iov_len <= siz) {
uiop->uio_iovcnt--;
uiop->uio_iov++;
} else {
uiop->uio_iov->iov_base =
(char *)uiop->uio_iov->iov_base + uiosiz;
uiop->uio_iov->iov_len -= uiosiz;
}
siz -= uiosiz;
}
*dpos = mbufcp;
*mrep = mp;
if (rem > 0) {
if (len < rem)
error = nfs_adv(mrep, dpos, rem, len);
else
*dpos += rem;
}
return (error);
}
/*
* Help break down an mbuf chain by setting the first siz bytes contiguous
* pointed to by returned val.
* This is used by the macros nfsm_dissect for tough
* cases. (The macros use the vars. dpos and dpos2)
*/
void *
nfsm_disct(struct mbuf **mdp, caddr_t *dposp, int siz, int left, int how)
{
struct mbuf *mp, *mp2;
int siz2, xfer;
caddr_t ptr, npos = NULL;
void *ret;
mp = *mdp;
while (left == 0) {
*mdp = mp = mp->m_next;
if (mp == NULL)
return (NULL);
left = mp->m_len;
*dposp = mtod(mp, caddr_t);
}
if (left >= siz) {
ret = *dposp;
*dposp += siz;
} else if (mp->m_next == NULL) {
return (NULL);
} else if (siz > MHLEN) {
panic("nfs S too big");
} else {
mp2 = m_get(how, MT_DATA);
if (mp2 == NULL)
return (NULL);
mp2->m_len = siz;
mp2->m_next = mp->m_next;
mp->m_next = mp2;
mp->m_len -= left;
mp = mp2;
ptr = mtod(mp, caddr_t);
ret = ptr;
bcopy(*dposp, ptr, left); /* Copy what was left */
siz2 = siz-left;
ptr += left;
mp2 = mp->m_next;
npos = mtod(mp2, caddr_t);
/* Loop around copying up the siz2 bytes */
while (siz2 > 0) {
if (mp2 == NULL)
return (NULL);
xfer = (siz2 > mp2->m_len) ? mp2->m_len : siz2;
if (xfer > 0) {
bcopy(mtod(mp2, caddr_t), ptr, xfer);
mp2->m_data += xfer;
mp2->m_len -= xfer;
ptr += xfer;
siz2 -= xfer;
}
if (siz2 > 0) {
mp2 = mp2->m_next;
if (mp2 != NULL)
npos = mtod(mp2, caddr_t);
}
}
*mdp = mp2;
*dposp = mtod(mp2, caddr_t);
if (!nfsm_aligned(*dposp, u_int32_t)) {
bcopy(*dposp, npos, mp2->m_len);
mp2->m_data = npos;
*dposp = npos;
}
}
return (ret);
}
/*
* Advance the position in the mbuf chain.
*/
int
nfs_adv(struct mbuf **mdp, caddr_t *dposp, int offs, int left)
{
struct mbuf *m;
int s;
m = *mdp;
s = left;
while (s < offs) {
offs -= s;
m = m->m_next;
if (m == NULL)
return (EBADRPC);
s = m->m_len;
}
*mdp = m;
*dposp = mtod(m, caddr_t)+offs;
return (0);
}
void *
nfsm_build_xx(int s, struct mbuf **mb, caddr_t *bpos)
{
struct mbuf *mb2;
void *ret;
if (s > M_TRAILINGSPACE(*mb)) {
mb2 = m_get(M_WAITOK, MT_DATA);
if (s > MLEN)
panic("build > MLEN");
(*mb)->m_next = mb2;
*mb = mb2;
(*mb)->m_len = 0;
*bpos = mtod(*mb, caddr_t);
}
ret = *bpos;
(*mb)->m_len += s;
*bpos += s;
return (ret);
}
void *
nfsm_dissect_xx(int s, struct mbuf **md, caddr_t *dpos)
{
return (nfsm_dissect_xx_sub(s, md, dpos, M_WAITOK));
}
void *
nfsm_dissect_xx_nonblock(int s, struct mbuf **md, caddr_t *dpos)
{
return (nfsm_dissect_xx_sub(s, md, dpos, M_NOWAIT));
}
static void *
nfsm_dissect_xx_sub(int s, struct mbuf **md, caddr_t *dpos, int how)
{
int t1;
char *cp2;
void *ret;
t1 = mtod(*md, caddr_t) + (*md)->m_len - *dpos;
if (t1 >= s) {
ret = *dpos;
*dpos += s;
return (ret);
}
cp2 = nfsm_disct(md, dpos, s, t1, how);
return (cp2);
}
int
nfsm_strsiz_xx(int *s, int m, struct mbuf **mb, caddr_t *bpos)
{
u_int32_t *tl;
tl = nfsm_dissect_xx(NFSX_UNSIGNED, mb, bpos);
if (tl == NULL)
return (EBADRPC);
*s = fxdr_unsigned(int32_t, *tl);
if (*s > m)
return (EBADRPC);
return (0);
}
int
nfsm_adv_xx(int s, struct mbuf **md, caddr_t *dpos)
{
int t1;
t1 = mtod(*md, caddr_t) + (*md)->m_len - *dpos;
if (t1 >= s) {
*dpos += s;
return (0);
}
t1 = nfs_adv(md, dpos, s, t1);
if (t1)
return (t1);
return (0);
}
/*
* Check for badly aligned mbuf data and realign by copying the unaligned
* portion of the data into a new mbuf chain and freeing the portions of the
* old chain that were replaced.
*
* We cannot simply realign the data within the existing mbuf chain because
* the underlying buffers may contain other rpc commands and we cannot afford
* to overwrite them.
*
* We would prefer to avoid this situation entirely. The situation does not
* occur with NFS/UDP and is supposed to only occassionally occur with TCP.
* Use vfs.nfs_common.realign_count and realign_test to check this.
*/
int
nfs_realign(struct mbuf **pm, int how)
{
struct mbuf *m, *n;
int off;
++nfs_realign_test;
while ((m = *pm) != NULL) {
if (!nfsm_aligned(m->m_len, u_int32_t) ||
!nfsm_aligned(mtod(m, intptr_t), u_int32_t)) {
/*
* NB: we can't depend on m_pkthdr.len to help us
* decide what to do here. May not be worth doing
* the m_length calculation as m_copyback will
* expand the mbuf chain below as needed.
*/
if (m_length(m, NULL) >= MINCLSIZE) {
/* NB: m_copyback handles space > MCLBYTES */
n = m_getcl(how, MT_DATA, 0);
} else
n = m_get(how, MT_DATA);
if (n == NULL)
return (ENOMEM);
/*
* Align the remainder of the mbuf chain.
*/
n->m_len = 0;
off = 0;
while (m != NULL) {
m_copyback(n, off, m->m_len, mtod(m, caddr_t));
off += m->m_len;
m = m->m_next;
}
m_freem(*pm);
*pm = n;
++nfs_realign_count;
break;
}
pm = &m->m_next;
}
return (0);
}
static moduledata_t nfs_common_mod = {
"nfs_common",
NULL,
NULL
};
DECLARE_MODULE(nfs_common, nfs_common_mod, SI_SUB_VFS, SI_ORDER_ANY);
MODULE_VERSION(nfs_common, 1);