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NetBSD/sys/nfs/nfs_subs.c

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/*
* Copyright (c) 1989 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* from: @(#)nfs_subs.c 7.41 (Berkeley) 5/15/91
* $Id: nfs_subs.c,v 1.6 1993/07/13 10:40:07 cgd Exp $
*/
/*
* 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 "param.h"
#include "proc.h"
#include "filedesc.h"
#include "systm.h"
#include "kernel.h"
#include "mount.h"
#include "file.h"
#include "vnode.h"
#include "namei.h"
#include "mbuf.h"
#include "../ufs/quota.h"
#include "../ufs/inode.h"
#include "rpcv2.h"
#include "nfsv2.h"
#include "nfsnode.h"
#include "nfs.h"
#include "nfsiom.h"
#include "xdr_subs.h"
#include "nfsm_subs.h"
#include "nfscompress.h"
#define TRUE 1
#define FALSE 0
/*
* Data items converted to xdr at startup, since they are constant
* This is kinda hokey, but may save a little time doing byte swaps
*/
u_long nfs_procids[NFS_NPROCS];
u_long nfs_xdrneg1;
u_long rpc_call, rpc_vers, rpc_reply, rpc_msgdenied,
rpc_mismatch, rpc_auth_unix, rpc_msgaccepted;
u_long nfs_vers, nfs_prog, nfs_true, nfs_false;
/* And other global data */
static u_long *rpc_uidp = (u_long *)0;
static u_long nfs_xid = 1;
static char *rpc_unixauth;
extern long hostid;
extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON];
extern struct nfsreq nfsreqh;
/* Function ret types */
static char *nfs_unixauth();
/*
* Maximum number of groups passed through to NFS server.
* According to RFC1057 it should be 16.
* For release 3.X systems, the maximum value is 8.
* For some other servers, the maximum value is 10.
*/
int numgrps = 8;
/*
* Create the header for an rpc request packet
* The function nfs_unixauth() creates a unix style authorization string
* and returns a ptr to it.
* The hsiz is the size of the rest of the nfs request header.
* (just used to decide if a cluster is a good idea)
* nb: Note that the prog, vers and procid args are already in xdr byte order
*/
struct mbuf *nfsm_reqh(prog, vers, procid, cred, hsiz, bpos, mb, retxid)
u_long prog;
u_long vers;
u_long procid;
struct ucred *cred;
int hsiz;
caddr_t **bpos;
struct mbuf **mb;
u_long *retxid;
{
register struct mbuf *mreq, *m;
register u_long *tl;
struct mbuf *m1;
char *ap;
int asiz, siz;
static char authnull[4*NFSX_UNSIGNED];
NFSMGETHDR(mreq);
if (cred != NOCRED) {
asiz = ((((cred->cr_ngroups - 1) > numgrps) ? numgrps :
(cred->cr_ngroups - 1)) << 2);
#ifdef FILLINHOST
asiz += nfsm_rndup(hostnamelen)+(9*NFSX_UNSIGNED);
#else
asiz += 9*NFSX_UNSIGNED;
#endif
} else
asiz = 4 * NFSX_UNSIGNED;
/* If we need a lot, alloc a cluster ?? */
if ((asiz+hsiz+RPC_SIZ) > MHLEN)
MCLGET(mreq, M_WAIT);
mreq->m_len = NFSMSIZ(mreq);
siz = mreq->m_len;
m1 = mreq;
/*
* Alloc enough mbufs
* We do it now to avoid all sleeps after the call to nfs_unixauth()
*/
while ((asiz+RPC_SIZ) > siz) {
MGET(m, M_WAIT, MT_DATA);
m1->m_next = m;
m->m_len = MLEN;
siz += MLEN;
m1 = m;
}
tl = mtod(mreq, u_long *);
*tl++ = *retxid = txdr_unsigned(++nfs_xid);
*tl++ = rpc_call;
*tl++ = rpc_vers;
*tl++ = prog;
*tl++ = vers;
*tl++ = procid;
/* Now we can call nfs_unixauth() and copy it in */
if (cred != NOCRED)
ap = nfs_unixauth(cred);
else
ap = authnull;
m = mreq;
siz = m->m_len-RPC_SIZ;
if (asiz <= siz) {
bcopy(ap, (caddr_t)tl, asiz);
m->m_len = asiz+RPC_SIZ;
} else {
bcopy(ap, (caddr_t)tl, siz);
ap += siz;
asiz -= siz;
while (asiz > 0) {
siz = (asiz > MLEN) ? MLEN : asiz;
m = m->m_next;
bcopy(ap, mtod(m, caddr_t), siz);
m->m_len = siz;
asiz -= siz;
ap += siz;
}
}
/* Finally, return values */
*mb = m;
*bpos = mtod(m, caddr_t)+m->m_len;
return (mreq);
}
/*
* copies mbuf chain to the uio scatter/gather list
*/
nfsm_mbuftouio(mrep, uiop, siz, dpos)
struct mbuf **mrep;
register struct uio *uiop;
int siz;
caddr_t *dpos;
{
register char *mbufcp, *uiocp;
register int xfer, left, len;
register 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 += 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);
}
/*
* copies a uio scatter/gather list to an mbuf chain...
*/
nfsm_uiotombuf(uiop, mq, siz, bpos)
register struct uio *uiop;
struct mbuf **mq;
int siz;
caddr_t *bpos;
{
register char *uiocp;
register struct mbuf *mp, *mp2;
register int xfer, left, len;
int uiosiz, clflg, rem;
char *cp;
if (siz > MLEN) /* or should it >= MCLBYTES ?? */
clflg = 1;
else
clflg = 0;
rem = nfsm_rndup(siz)-siz;
mp2 = *mq;
while (siz > 0) {
if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
return (EINVAL);
left = uiop->uio_iov->iov_len;
uiocp = uiop->uio_iov->iov_base;
if (left > siz)
left = siz;
uiosiz = left;
while (left > 0) {
MGET(mp, M_WAIT, MT_DATA);
if (clflg)
MCLGET(mp, M_WAIT);
mp->m_len = NFSMSIZ(mp);
mp2->m_next = mp;
mp2 = mp;
xfer = (left > mp->m_len) ? mp->m_len : left;
#ifdef notdef
/* Not Yet.. */
if (uiop->uio_iov->iov_op != NULL)
(*(uiop->uio_iov->iov_op))
(uiocp, mtod(mp, caddr_t), xfer);
else
#endif
if (uiop->uio_segflg == UIO_SYSSPACE)
bcopy(uiocp, mtod(mp, caddr_t), xfer);
else
copyin(uiocp, mtod(mp, caddr_t), xfer);
len = mp->m_len;
mp->m_len = xfer;
left -= 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 += uiosiz;
uiop->uio_iov->iov_len -= uiosiz;
}
siz -= uiosiz;
}
if (rem > 0) {
if (rem > (len-mp->m_len)) {
MGET(mp, M_WAIT, MT_DATA);
mp->m_len = 0;
mp2->m_next = mp;
}
cp = mtod(mp, caddr_t)+mp->m_len;
for (left = 0; left < rem; left++)
*cp++ = '\0';
mp->m_len += rem;
*bpos = cp;
} else
*bpos = mtod(mp, caddr_t)+mp->m_len;
*mq = mp;
return (0);
}
/*
* Help break down an mbuf chain by setting the first siz bytes contiguous
* pointed to by returned val.
* If Updateflg == True we can overwrite the first part of the mbuf data
* This is used by the macros nfsm_disect and nfsm_disecton for tough
* cases. (The macros use the vars. dpos and dpos2)
*/
nfsm_disct(mdp, dposp, siz, left, updateflg, cp2)
struct mbuf **mdp;
caddr_t *dposp;
int siz;
int left;
int updateflg;
caddr_t *cp2;
{
register struct mbuf *mp, *mp2;
register int siz2, xfer;
register caddr_t tl;
mp = *mdp;
while (left == 0) {
*mdp = mp = mp->m_next;
if (mp == NULL)
return (EBADRPC);
left = mp->m_len;
*dposp = mtod(mp, caddr_t);
}
if (left >= siz) {
*cp2 = *dposp;
*dposp += siz;
} else if (mp->m_next == NULL) {
return (EBADRPC);
} else if (siz > MHLEN) {
panic("nfs S too big");
} else {
/* Iff update, you can overwrite, else must alloc new mbuf */
if (updateflg) {
NFSMINOFF(mp);
} else {
MGET(mp2, M_WAIT, MT_DATA);
mp2->m_next = mp->m_next;
mp->m_next = mp2;
mp->m_len -= left;
mp = mp2;
}
*cp2 = tl = mtod(mp, caddr_t);
bcopy(*dposp, tl, left); /* Copy what was left */
siz2 = siz-left;
tl += left;
mp2 = mp->m_next;
/* Loop around copying up the siz2 bytes */
while (siz2 > 0) {
if (mp2 == NULL)
return (EBADRPC);
xfer = (siz2 > mp2->m_len) ? mp2->m_len : siz2;
if (xfer > 0) {
bcopy(mtod(mp2, caddr_t), tl, xfer);
NFSMADV(mp2, xfer);
mp2->m_len -= xfer;
tl += xfer;
siz2 -= xfer;
}
if (siz2 > 0)
mp2 = mp2->m_next;
}
mp->m_len = siz;
*mdp = mp2;
*dposp = mtod(mp2, caddr_t);
}
return (0);
}
/*
* Advance the position in the mbuf chain.
*/
nfs_adv(mdp, dposp, offs, left)
struct mbuf **mdp;
caddr_t *dposp;
int offs;
int left;
{
register struct mbuf *m;
register 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);
}
/*
* Copy a string into mbufs for the hard cases...
*/
nfsm_strtmbuf(mb, bpos, cp, siz)
struct mbuf **mb;
char **bpos;
char *cp;
long siz;
{
register struct mbuf *m1, *m2;
long left, xfer, len, tlen;
u_long *tl;
int putsize;
putsize = 1;
m2 = *mb;
left = NFSMSIZ(m2)-m2->m_len;
if (left > 0) {
tl = ((u_long *)(*bpos));
*tl++ = txdr_unsigned(siz);
putsize = 0;
left -= NFSX_UNSIGNED;
m2->m_len += NFSX_UNSIGNED;
if (left > 0) {
bcopy(cp, (caddr_t) tl, left);
siz -= left;
cp += left;
m2->m_len += left;
left = 0;
}
}
/* Loop arround adding mbufs */
while (siz > 0) {
MGET(m1, M_WAIT, MT_DATA);
if (siz > MLEN)
MCLGET(m1, M_WAIT);
m1->m_len = NFSMSIZ(m1);
m2->m_next = m1;
m2 = m1;
tl = mtod(m1, u_long *);
tlen = 0;
if (putsize) {
*tl++ = txdr_unsigned(siz);
m1->m_len -= NFSX_UNSIGNED;
tlen = NFSX_UNSIGNED;
putsize = 0;
}
if (siz < m1->m_len) {
len = nfsm_rndup(siz);
xfer = siz;
if (xfer < len)
*(tl+(xfer>>2)) = 0;
} else {
xfer = len = m1->m_len;
}
bcopy(cp, (caddr_t) tl, xfer);
m1->m_len = len+tlen;
siz -= xfer;
cp += xfer;
}
*mb = m1;
*bpos = mtod(m1, caddr_t)+m1->m_len;
return (0);
}
/*
* Called once to initialize data structures...
*/
nfs_init()
{
register int i;
rpc_vers = txdr_unsigned(RPC_VER2);
rpc_call = txdr_unsigned(RPC_CALL);
rpc_reply = txdr_unsigned(RPC_REPLY);
rpc_msgdenied = txdr_unsigned(RPC_MSGDENIED);
rpc_msgaccepted = txdr_unsigned(RPC_MSGACCEPTED);
rpc_mismatch = txdr_unsigned(RPC_MISMATCH);
rpc_auth_unix = txdr_unsigned(RPCAUTH_UNIX);
nfs_vers = txdr_unsigned(NFS_VER2);
nfs_prog = txdr_unsigned(NFS_PROG);
nfs_true = txdr_unsigned(TRUE);
nfs_false = txdr_unsigned(FALSE);
/* Loop thru nfs procids */
for (i = 0; i < NFS_NPROCS; i++)
nfs_procids[i] = txdr_unsigned(i);
/* Ensure async daemons disabled */
nfs_xdrneg1 = txdr_unsigned(-1);
#ifdef NFSCLIENT
for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
nfs_iodwant[i] = (struct proc *)0;
nfs_nhinit(); /* Init the nfsnode table */
#endif /* NFSCLIENT */
#ifdef NFSSERVER
nfsrv_initcache(); /* Init the server request cache */
#endif /*NFSSERVER */
/*
* Initialize reply list and start timer
*/
nfsreqh.r_prev = nfsreqh.r_next = &nfsreqh;
nfs_timer();
}
/*
* Fill in the rest of the rpc_unixauth and return it
*/
static char *nfs_unixauth(cr)
register struct ucred *cr;
{
register u_long *tl;
register int i;
int ngr;
/* Maybe someday there should be a cache of AUTH_SHORT's */
if ((tl = rpc_uidp) == NULL) {
#ifdef FILLINHOST
i = nfsm_rndup(hostnamelen)+(25*NFSX_UNSIGNED);
#else
i = 25*NFSX_UNSIGNED;
#endif
MALLOC(tl, u_long *, i, M_TEMP, M_WAITOK);
bzero((caddr_t)tl, i);
rpc_unixauth = (caddr_t)tl;
*tl++ = txdr_unsigned(RPCAUTH_UNIX);
tl++; /* Fill in size later */
*tl++ = hostid;
#ifdef FILLINHOST
*tl++ = txdr_unsigned(hostnamelen);
i = nfsm_rndup(hostnamelen);
bcopy(hostname, (caddr_t)tl, hostnamelen);
tl += (i>>2);
#else
*tl++ = 0;
#endif
rpc_uidp = tl;
}
*tl++ = txdr_unsigned(cr->cr_uid);
*tl++ = txdr_unsigned(cr->cr_groups[0]);
ngr = ((cr->cr_ngroups - 1) > numgrps) ? numgrps : (cr->cr_ngroups - 1);
*tl++ = txdr_unsigned(ngr);
for (i = 1; i <= ngr; i++)
*tl++ = txdr_unsigned(cr->cr_groups[i]);
/* And add the AUTH_NULL */
*tl++ = 0;
*tl = 0;
i = (((caddr_t)tl)-rpc_unixauth)-12;
tl = (u_long *)(rpc_unixauth+4);
*tl = txdr_unsigned(i);
return (rpc_unixauth);
}
/*
* Set up nameidata for a namei() call and do it
*/
nfs_namei(ndp, fhp, len, mdp, dposp, p)
register struct nameidata *ndp;
fhandle_t *fhp;
int len;
struct mbuf **mdp;
caddr_t *dposp;
struct proc *p;
{
register int i, rem;
register struct mbuf *md;
register char *fromcp, *tocp;
struct vnode *dp;
int flag;
int error;
flag = ndp->ni_nameiop & OPMASK;
MALLOC(ndp->ni_pnbuf, char *, len + 1, M_NAMEI, M_WAITOK);
/*
* Copy the name from the mbuf list to ndp->ni_pnbuf
* and set the various ndp fields appropriately.
*/
fromcp = *dposp;
tocp = ndp->ni_pnbuf;
md = *mdp;
rem = mtod(md, caddr_t) + md->m_len - fromcp;
ndp->ni_hash = 0;
for (i = 0; i < len; i++) {
while (rem == 0) {
md = md->m_next;
if (md == NULL) {
error = EBADRPC;
goto out;
}
fromcp = mtod(md, caddr_t);
rem = md->m_len;
}
if (*fromcp == '\0' || *fromcp == '/') {
error = EINVAL;
goto out;
}
if (*fromcp & 0200)
if ((*fromcp&0377) == ('/'|0200) || flag != DELETE) {
error = EINVAL;
goto out;
}
ndp->ni_hash += (unsigned char)*fromcp;
*tocp++ = *fromcp++;
rem--;
}
*tocp = '\0';
*mdp = md;
*dposp = fromcp;
len = nfsm_rndup(len)-len;
if (len > 0) {
if (rem >= len)
*dposp += len;
else if (error = nfs_adv(mdp, dposp, len, rem))
goto out;
}
ndp->ni_pathlen = tocp - ndp->ni_pnbuf;
ndp->ni_ptr = ndp->ni_pnbuf;
/*
* Extract and set starting directory.
*/
if (error = nfsrv_fhtovp(fhp, FALSE, &dp, ndp->ni_cred))
goto out;
if (dp->v_type != VDIR) {
vrele(dp);
error = ENOTDIR;
goto out;
}
ndp->ni_startdir = dp;
ndp->ni_nameiop |= (NOCROSSMOUNT | REMOTE);
/*
* And call lookup() to do the real work
*/
if (error = lookup(ndp, p))
goto out;
/*
* Check for encountering a symbolic link
*/
if (ndp->ni_more) {
if ((ndp->ni_nameiop & LOCKPARENT) && ndp->ni_pathlen == 1)
vput(ndp->ni_dvp);
else
vrele(ndp->ni_dvp);
vput(ndp->ni_vp);
ndp->ni_vp = NULL;
error = EINVAL;
goto out;
}
/*
* Check for saved name request
*/
if (ndp->ni_nameiop & (SAVENAME | SAVESTART)) {
ndp->ni_nameiop |= HASBUF;
return (0);
}
out:
FREE(ndp->ni_pnbuf, M_NAMEI);
return (error);
}
/*
* A fiddled version of m_adj() that ensures null fill to a long
* boundary and only trims off the back end
*/
nfsm_adj(mp, len, nul)
struct mbuf *mp;
register int len;
int nul;
{
register struct mbuf *m;
register int count, i;
register char *cp;
/*
* Trim from tail. Scan the mbuf chain,
* calculating its length and finding the last mbuf.
* If the adjustment only affects this mbuf, then just
* adjust and return. Otherwise, rescan and truncate
* after the remaining size.
*/
count = 0;
m = mp;
for (;;) {
count += m->m_len;
if (m->m_next == (struct mbuf *)0)
break;
m = m->m_next;
}
if (m->m_len > len) {
m->m_len -= len;
if (nul > 0) {
cp = mtod(m, caddr_t)+m->m_len-nul;
for (i = 0; i < nul; i++)
*cp++ = '\0';
}
return;
}
count -= len;
if (count < 0)
count = 0;
/*
* Correct length for chain is "count".
* Find the mbuf with last data, adjust its length,
* and toss data from remaining mbufs on chain.
*/
for (m = mp; m; m = m->m_next) {
if (m->m_len >= count) {
m->m_len = count;
if (nul > 0) {
cp = mtod(m, caddr_t)+m->m_len-nul;
for (i = 0; i < nul; i++)
*cp++ = '\0';
}
break;
}
count -= m->m_len;
}
while (m = m->m_next)
m->m_len = 0;
}
/*
* nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked)
* - look up fsid in mount list (if not found ret error)
* - check that it is exported
* - get vp by calling VFS_FHTOVP() macro
* - if not lockflag unlock it with VOP_UNLOCK()
* - if cred->cr_uid == 0 set it to m_exroot
*/
nfsrv_fhtovp(fhp, lockflag, vpp, cred)
fhandle_t *fhp;
int lockflag;
struct vnode **vpp;
struct ucred *cred;
{
register struct mount *mp;
if ((mp = getvfs(&fhp->fh_fsid)) == NULL)
return (ESTALE);
if ((mp->mnt_flag & MNT_EXPORTED) == 0)
return (EACCES);
if (VFS_FHTOVP(mp, &fhp->fh_fid, vpp))
return (ESTALE);
if (cred->cr_uid == 0)
cred->cr_uid = mp->mnt_exroot;
if (!lockflag)
VOP_UNLOCK(*vpp);
return (0);
}
/*
* These two functions implement nfs rpc compression.
* The algorithm is a trivial run length encoding of '\0' bytes. The high
* order nibble of hex "e" is or'd with the number of zeroes - 2 in four
* bits. (2 - 17 zeros) Any data byte with a high order nibble of hex "e"
* is byte stuffed.
* The compressed data is padded with 0x0 bytes to an even multiple of
* 4 bytes in length to avoid any weird long pointer alignments.
* If compression/uncompression is unsuccessful, the original mbuf list
* is returned.
* The first four bytes (the XID) are left uncompressed and the fifth
* byte is set to 0x1 for request and 0x2 for reply.
* An uncompressed RPC will always have the fifth byte == 0x0.
*/
struct mbuf *
nfs_compress(m0)
struct mbuf *m0;
{
register u_char ch, nextch;
register int i, rlelast;
register u_char *ip, *op;
register int ileft, oleft, noteof;
register struct mbuf *m, *om;
struct mbuf **mp, *retm;
int olen, clget;
i = rlelast = 0;
noteof = 1;
m = m0;
if (m->m_len < 12)
return (m0);
if (m->m_pkthdr.len >= MINCLSIZE)
clget = 1;
else
clget = 0;
ileft = m->m_len - 9;
ip = mtod(m, u_char *);
MGETHDR(om, M_WAIT, MT_DATA);
if (clget)
MCLGET(om, M_WAIT);
retm = om;
mp = &om->m_next;
olen = om->m_len = 5;
oleft = M_TRAILINGSPACE(om);
op = mtod(om, u_char *);
*((u_long *)op) = *((u_long *)ip);
ip += 7;
op += 4;
*op++ = *ip++ + 1;
nextch = *ip++;
while (noteof) {
ch = nextch;
if (ileft == 0) {
do {
m = m->m_next;
} while (m && m->m_len == 0);
if (m) {
ileft = m->m_len;
ip = mtod(m, u_char *);
} else {
noteof = 0;
nextch = 0x1;
goto doit;
}
}
nextch = *ip++;
ileft--;
doit:
if (ch == '\0') {
if (++i == NFSC_MAX || nextch != '\0') {
if (i < 2) {
nfscput('\0');
} else {
if (rlelast == i) {
nfscput('\0');
i--;
}
if (NFSCRLE(i) == (nextch & 0xff)) {
i--;
if (i < 2) {
nfscput('\0');
} else {
nfscput(NFSCRLE(i));
}
nfscput('\0');
rlelast = 0;
} else {
nfscput(NFSCRLE(i));
rlelast = i;
}
}
i = 0;
}
} else {
if ((ch & NFSCRL) == NFSCRL) {
nfscput(ch);
}
nfscput(ch);
i = rlelast = 0;
}
}
if (olen < m0->m_pkthdr.len) {
m_freem(m0);
if (i = (olen & 0x3)) {
i = 4 - i;
while (i-- > 0) {
nfscput('\0');
}
}
retm->m_pkthdr.len = olen;
retm->m_pkthdr.rcvif = (struct ifnet *)0;
return (retm);
} else {
m_freem(retm);
return (m0);
}
}
struct mbuf *
nfs_uncompress(m0)
struct mbuf *m0;
{
register u_char cp, nextcp, *ip, *op;
register struct mbuf *m, *om;
struct mbuf *retm, **mp;
int i, j, noteof, clget, ileft, oleft, olen;
m = m0;
i = 0;
while (m && i < MINCLSIZE) {
i += m->m_len;
m = m->m_next;
}
if (i < 6)
return (m0);
if (i >= MINCLSIZE)
clget = 1;
else
clget = 0;
m = m0;
MGET(om, M_WAIT, MT_DATA);
if (clget)
MCLGET(om, M_WAIT);
olen = om->m_len = 8;
oleft = M_TRAILINGSPACE(om);
op = mtod(om, u_char *);
retm = om;
mp = &om->m_next;
if (m->m_len >= 6) {
ileft = m->m_len - 6;
ip = mtod(m, u_char *);
*((u_long *)op) = *((u_long *)ip);
bzero(op + 4, 3);
ip += 4;
op += 7;
if (*ip == '\0') {
m_freem(om);
return (m0);
}
*op++ = *ip++ - 1;
cp = *ip++;
} else {
ileft = m->m_len;
ip = mtod(m, u_char *);
nfscget(*op++);
nfscget(*op++);
nfscget(*op++);
nfscget(*op++);
bzero(op, 3);
op += 3;
nfscget(*op);
if (*op == '\0') {
m_freem(om);
return (m0);
}
(*op)--;
op++;
nfscget(cp);
}
noteof = 1;
while (noteof) {
if ((cp & NFSCRL) == NFSCRL) {
nfscget(nextcp);
if (cp == nextcp) {
nfscput(cp);
goto readit;
} else {
i = (cp & 0xf) + 2;
for (j = 0; j < i; j++) {
nfscput('\0');
}
cp = nextcp;
}
} else {
nfscput(cp);
readit:
nfscget(cp);
}
}
m_freem(m0);
if (i = (olen & 0x3))
om->m_len -= i;
return (retm);
}
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