/* $NetBSD: nfs_clntsocket.c,v 1.7 2024/07/05 04:31:54 rin Exp $ */
/*
* Copyright (c) 1989, 1991, 1993, 1995
* 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. 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_socket.c 8.5 (Berkeley) 3/30/95
*/
/*
* Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
* done by soreceive(), but for SOCK_STREAM we must deal with the Record
* Mark and consolidate the data into a new mbuf list.
* nb: Sometimes TCP passes the data up to soreceive() in long lists of
* small mbufs.
* For SOCK_STREAM we must be very careful to read an entire record once
* we have read any of it, even if the system call has been interrupted.
*/
static int
nfs_receive(struct nfsreq *rep, struct mbuf **aname, struct mbuf **mp,
struct lwp *l)
{
struct socket *so;
struct uio auio;
struct iovec aio;
struct mbuf *m;
struct mbuf *control;
u_int32_t len;
struct mbuf **getnam;
int error, sotype, rcvflg;
/*
* Set up arguments for soreceive()
*/
*mp = NULL;
*aname = NULL;
sotype = rep->r_nmp->nm_sotype;
/*
* For reliable protocols, lock against other senders/receivers
* in case a reconnect is necessary.
* For SOCK_STREAM, first get the Record Mark to find out how much
* more there is to get.
* We must lock the socket against other receivers
* until we have an entire rpc request/reply.
*/
if (sotype != SOCK_DGRAM) {
error = nfs_sndlock(rep->r_nmp, rep);
if (error)
return (error);
tryagain:
/*
* Check for fatal errors and resending request.
*/
/*
* Ugh: If a reconnect attempt just happened, nm_so
* would have changed. NULL indicates a failed
* attempt that has essentially shut down this
* mount point.
*/
if (rep->r_mrep || (rep->r_flags & R_SOFTTERM)) {
nfs_sndunlock(rep->r_nmp);
return (EINTR);
}
so = rep->r_nmp->nm_so;
if (!so) {
error = nfs_reconnect(rep);
if (error) {
nfs_sndunlock(rep->r_nmp);
return (error);
}
goto tryagain;
}
while (rep->r_flags & R_MUSTRESEND) {
m = m_copym(rep->r_mreq, 0, M_COPYALL, M_WAIT);
nfsstats.rpcretries++;
rep->r_rtt = 0;
rep->r_flags &= ~R_TIMING;
error = nfs_send(so, rep->r_nmp->nm_nam, m, rep, l);
if (error) {
if (error == EINTR || error == ERESTART ||
(error = nfs_reconnect(rep)) != 0) {
nfs_sndunlock(rep->r_nmp);
return (error);
}
goto tryagain;
}
}
nfs_sndunlock(rep->r_nmp);
if (sotype == SOCK_STREAM) {
aio.iov_base = (void *) &len;
aio.iov_len = sizeof(u_int32_t);
auio.uio_iov = &aio;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_READ;
auio.uio_offset = 0;
auio.uio_resid = sizeof(u_int32_t);
UIO_SETUP_SYSSPACE(&auio);
do {
rcvflg = MSG_WAITALL;
error = (*so->so_receive)(so, NULL, &auio,
NULL, NULL, &rcvflg);
if (error == EWOULDBLOCK && rep) {
if (rep->r_flags & R_SOFTTERM)
return (EINTR);
/*
* if it seems that the server died after it
* received our request, set EPIPE so that
* we'll reconnect and retransmit requests.
*/
if (rep->r_rexmit >= rep->r_nmp->nm_retry) {
nfsstats.rpctimeouts++;
error = EPIPE;
}
}
} while (error == EWOULDBLOCK);
if (!error && auio.uio_resid > 0) {
/*
* Don't log a 0 byte receive; it means
* that the socket has been closed, and
* can happen during normal operation
* (forcible unmount or Solaris server).
*/
if (auio.uio_resid != sizeof (u_int32_t))
log(LOG_INFO,
"short receive (%lu/%lu) from nfs server %s\n",
(u_long)sizeof(u_int32_t) - auio.uio_resid,
(u_long)sizeof(u_int32_t),
rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
error = EPIPE;
}
if (error)
goto errout;
len = ntohl(len) & ~0x80000000;
/*
* This is SERIOUS! We are out of sync with the sender
* and forcing a disconnect/reconnect is all I can do.
*/
if (len > NFS_MAXPACKET) {
log(LOG_ERR, "%s (%d) from nfs server %s\n",
"impossible packet length",
len,
rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
error = EFBIG;
goto errout;
}
auio.uio_resid = len;
do {
rcvflg = MSG_WAITALL;
error = (*so->so_receive)(so, NULL,
&auio, mp, NULL, &rcvflg);
} while (error == EWOULDBLOCK || error == EINTR ||
error == ERESTART);
if (!error && auio.uio_resid > 0) {
if (len != auio.uio_resid)
log(LOG_INFO,
"short receive (%lu/%d) from nfs server %s\n",
(u_long)len - auio.uio_resid, len,
rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
error = EPIPE;
}
} else {
/*
* NB: Since uio_resid is big, MSG_WAITALL is ignored
* and soreceive() will return when it has either a
* control msg or a data msg.
* We have no use for control msg., but must grab them
* and then throw them away so we know what is going
* on.
*/
auio.uio_resid = len = 100000000; /* Anything Big */
/* not need to setup uio_vmspace */
do {
rcvflg = 0;
error = (*so->so_receive)(so, NULL,
&auio, mp, &control, &rcvflg);
m_freem(control);
if (error == EWOULDBLOCK && rep) {
if (rep->r_flags & R_SOFTTERM)
return (EINTR);
}
} while (error == EWOULDBLOCK ||
(!error && *mp == NULL && control));
if ((rcvflg & MSG_EOR) == 0)
printf("Egad!!\n");
if (!error && *mp == NULL)
error = EPIPE;
len -= auio.uio_resid;
}
errout:
if (error && error != EINTR && error != ERESTART) {
m_freem(*mp);
*mp = NULL;
if (error != EPIPE)
log(LOG_INFO,
"receive error %d from nfs server %s\n",
error,
rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
error = nfs_sndlock(rep->r_nmp, rep);
if (!error)
error = nfs_reconnect(rep);
if (!error)
goto tryagain;
else
nfs_sndunlock(rep->r_nmp);
}
} else {
if ((so = rep->r_nmp->nm_so) == NULL)
return (EACCES);
if (so->so_state & SS_ISCONNECTED)
getnam = NULL;
else
getnam = aname;
auio.uio_resid = len = 1000000;
/* not need to setup uio_vmspace */
do {
rcvflg = 0;
error = (*so->so_receive)(so, getnam, &auio, mp,
NULL, &rcvflg);
if (error == EWOULDBLOCK) {
int intr = nfs_sigintr(rep->r_nmp, rep, l);
if (intr)
error = intr;
}
} while (error == EWOULDBLOCK);
len -= auio.uio_resid;
if (!error && *mp == NULL)
error = EPIPE;
}
if (error) {
m_freem(*mp);
*mp = NULL;
}
return (error);
}
/*
* Implement receipt of reply on a socket.
* We must search through the list of received datagrams matching them
* with outstanding requests using the xid, until ours is found.
*/
/* ARGSUSED */
static int
nfs_reply(struct nfsreq *myrep, struct lwp *lwp)
{
struct nfsreq *rep;
struct nfsmount *nmp = myrep->r_nmp;
int32_t t1;
struct mbuf *mrep, *nam, *md;
u_int32_t rxid, *tl;
char *dpos, *cp2;
int error, s;
/*
* Loop around until we get our own reply
*/
for (;;) {
/*
* Lock against other receivers so that I don't get stuck in
* sbwait() after someone else has received my reply for me.
* Also necessary for connection based protocols to avoid
* race conditions during a reconnect.
*/
error = nfs_rcvlock(nmp, myrep);
if (error == EALREADY)
return (0);
if (error)
return (error);
/*
* Get the next Rpc reply off the socket
*/
/*
* Get the xid and check that it is an rpc reply
*/
md = mrep;
dpos = mtod(md, void *);
nfsm_dissect(tl, u_int32_t *, 2*NFSX_UNSIGNED);
rxid = *tl++;
if (*tl != rpc_reply) {
nfsstats.rpcinvalid++;
m_freem(mrep);
nfsmout:
nfs_rcvunlock(nmp);
continue;
}
/*
* Loop through the request list to match up the reply
* Iff no match, just drop the datagram
*/
s = splsoftnet();
mutex_enter(&nfs_reqq_lock);
TAILQ_FOREACH(rep, &nfs_reqq, r_chain) {
if (rep->r_mrep != NULL || rxid != rep->r_xid)
continue;
/* Found it.. */
rep->r_mrep = mrep;
rep->r_md = md;
rep->r_dpos = dpos;
if (nfsrtton) {
struct rttl *rt;
int proct = nfs_proct[rep->r_procnum];
rt = &nfsrtt.rttl[nfsrtt.pos];
rt->proc = rep->r_procnum;
rt->rto = NFS_RTO(nmp, proct);
rt->sent = nmp->nm_sent;
rt->cwnd = nmp->nm_cwnd;
rt->srtt = nmp->nm_srtt[proct - 1];
rt->sdrtt = nmp->nm_sdrtt[proct - 1];
rt->fsid = nmp->nm_mountp->mnt_stat.f_fsidx;
getmicrotime(&rt->tstamp);
if (rep->r_flags & R_TIMING)
rt->rtt = rep->r_rtt;
else
rt->rtt = 1000000;
nfsrtt.pos = (nfsrtt.pos + 1) % NFSRTTLOGSIZ;
}
/*
* Update congestion window.
* Do the additive increase of
* one rpc/rtt.
*/
if (nmp->nm_cwnd <= nmp->nm_sent) {
nmp->nm_cwnd +=
(NFS_CWNDSCALE * NFS_CWNDSCALE +
(nmp->nm_cwnd >> 1)) / nmp->nm_cwnd;
if (nmp->nm_cwnd > NFS_MAXCWND)
nmp->nm_cwnd = NFS_MAXCWND;
}
rep->r_flags &= ~R_SENT;
nmp->nm_sent -= NFS_CWNDSCALE;
/*
* Update rtt using a gain of 0.125 on the mean
* and a gain of 0.25 on the deviation.
*/
if (rep->r_flags & R_TIMING) {
/*
* Since the timer resolution of
* NFS_HZ is so course, it can often
* result in r_rtt == 0. Since
* r_rtt == N means that the actual
* rtt is between N+dt and N+2-dt ticks,
* add 1.
*/
t1 = rep->r_rtt + 1;
t1 -= (NFS_SRTT(rep) >> 3);
NFS_SRTT(rep) += t1;
if (t1 < 0)
t1 = -t1;
t1 -= (NFS_SDRTT(rep) >> 2);
NFS_SDRTT(rep) += t1;
}
nmp->nm_timeouts = 0;
break;
}
mutex_exit(&nfs_reqq_lock);
splx(s);
nfs_rcvunlock(nmp);
/*
* If not matched to a request, drop it.
* If it's mine, get out.
*/
if (rep == 0) {
nfsstats.rpcunexpected++;
m_freem(mrep);
} else if (rep == myrep) {
if (rep->r_mrep == NULL)
panic("nfsreply nil");
return (0);
}
}
}
/*
* nfs_request - goes something like this
* - fill in request struct
* - links it into list
* - calls nfs_send() for first transmit
* - calls nfs_receive() to get reply
* - break down rpc header and return with nfs reply pointed to
* by mrep or error
* nb: always frees up mreq mbuf list
*/
int
nfs_request(struct nfsnode *np, struct mbuf *mrest, int procnum, struct lwp *lwp, kauth_cred_t cred, struct mbuf **mrp, struct mbuf **mdp, char **dposp, int *rexmitp)
{
struct mbuf *m, *mrep;
struct nfsreq *rep;
u_int32_t *tl;
int i;
struct nfsmount *nmp = VFSTONFS(np->n_vnode->v_mount);
struct mbuf *md, *mheadend;
char nickv[RPCX_NICKVERF];
time_t waituntil;
char *dpos, *cp2;
int t1, s, error = 0, mrest_len, auth_len, auth_type;
int trylater_delay = NFS_TRYLATERDEL, failed_auth = 0;
int verf_len, verf_type;
u_int32_t xid;
char *auth_str, *verf_str;
NFSKERBKEY_T key; /* save session key */
kauth_cred_t acred;
struct mbuf *mrest_backup = NULL;
kauth_cred_t origcred = NULL; /* XXX: gcc */
bool retry_cred = true;
bool use_opencred = (np->n_flag & NUSEOPENCRED) != 0;
if (rexmitp != NULL)
*rexmitp = 0;
acred = kauth_cred_alloc();
tryagain_cred:
KASSERT(cred != NULL);
rep = kmem_alloc(sizeof(*rep), KM_SLEEP);
rep->r_nmp = nmp;
KASSERT(lwp == NULL || lwp == curlwp);
rep->r_lwp = lwp;
rep->r_procnum = procnum;
i = 0;
m = mrest;
while (m) {
i += m->m_len;
m = m->m_next;
}
mrest_len = i;
/*
* on the most unix filesystems, permission checks are
* done when the file is open(2)'ed.
* ie. once a file is successfully open'ed,
* following i/o operations never fail with EACCES.
* we try to follow the semantics as far as possible.
*
* note that we expect that the nfs server always grant
* accesses by the file's owner.
*/
origcred = cred;
switch (procnum) {
case NFSPROC_READ:
case NFSPROC_WRITE:
case NFSPROC_COMMIT:
uid = np->n_vattr->va_uid;
gid = np->n_vattr->va_gid;
if (kauth_cred_geteuid(cred) == uid &&
kauth_cred_getegid(cred) == gid) {
retry_cred = false;
break;
}
if (use_opencred)
break;
kauth_cred_setuid(acred, uid);
kauth_cred_seteuid(acred, uid);
kauth_cred_setsvuid(acred, uid);
kauth_cred_setgid(acred, gid);
kauth_cred_setegid(acred, gid);
kauth_cred_setsvgid(acred, gid);
cred = acred;
break;
default:
retry_cred = false;
break;
}
/*
* backup mbuf chain if we can need it later to retry.
*
* XXX maybe we can keep a direct reference to
* mrest without doing m_copym, but it's ...ugly.
*/
if (retry_cred)
mrest_backup = m_copym(mrest, 0, M_COPYALL, M_WAIT);
auth_type = RPCAUTH_UNIX;
/* XXX elad - ngroups */
auth_len = (((kauth_cred_ngroups(cred) > nmp->nm_numgrps) ?
nmp->nm_numgrps : kauth_cred_ngroups(cred)) << 2) +
5 * NFSX_UNSIGNED;
}
m = nfsm_rpchead(cred, nmp->nm_flag, procnum, auth_type, auth_len,
auth_str, verf_len, verf_str, mrest, mrest_len, &mheadend, &xid);
if (auth_str)
free(auth_str, M_TEMP);
/*
* For stream protocols, insert a Sun RPC Record Mark.
*/
if (nmp->nm_sotype == SOCK_STREAM) {
M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
*mtod(m, u_int32_t *) = htonl(0x80000000 |
(m->m_pkthdr.len - NFSX_UNSIGNED));
}
rep->r_mreq = m;
rep->r_xid = xid;
tryagain:
if (nmp->nm_flag & NFSMNT_SOFT)
rep->r_retry = nmp->nm_retry;
else
rep->r_retry = NFS_MAXREXMIT + 1; /* past clip limit */
rep->r_rtt = rep->r_rexmit = 0;
if (nfs_proct[procnum] > 0)
rep->r_flags = R_TIMING;
else
rep->r_flags = 0;
rep->r_mrep = NULL;
/*
* Do the client side RPC.
*/
nfsstats.rpcrequests++;
/*
* Chain request into list of outstanding requests. Be sure
* to put it LAST so timer finds oldest requests first.
*/
s = splsoftnet();
mutex_enter(&nfs_reqq_lock);
TAILQ_INSERT_TAIL(&nfs_reqq, rep, r_chain);
mutex_exit(&nfs_reqq_lock);
nfs_timer_start();
/*
* If backing off another request or avoiding congestion, don't
* send this one now but let timer do it. If not timing a request,
* do it now.
*/
if (nmp->nm_so && (nmp->nm_sotype != SOCK_DGRAM ||
(nmp->nm_flag & NFSMNT_DUMBTIMR) || nmp->nm_sent < nmp->nm_cwnd)) {
splx(s);
if (nmp->nm_soflags & PR_CONNREQUIRED)
error = nfs_sndlock(nmp, rep);
if (!error) {
m = m_copym(rep->r_mreq, 0, M_COPYALL, M_WAIT);
error = nfs_send(nmp->nm_so, nmp->nm_nam, m, rep, lwp);
if (nmp->nm_soflags & PR_CONNREQUIRED)
nfs_sndunlock(nmp);
}
s = splsoftnet();
if (!error && (rep->r_flags & R_MUSTRESEND) == 0) {
if ((rep->r_flags & R_SENT) == 0) {
nmp->nm_sent += NFS_CWNDSCALE;
rep->r_flags |= R_SENT;
}
}
splx(s);
} else {
splx(s);
rep->r_rtt = -1;
}
/*
* Wait for the reply from our send or the timer's.
*/
if (!error || error == EPIPE || error == EWOULDBLOCK)
error = nfs_reply(rep, lwp);
/*
* RPC done, unlink the request.
*/
s = splsoftnet();
mutex_enter(&nfs_reqq_lock);
TAILQ_REMOVE(&nfs_reqq, rep, r_chain);
mutex_exit(&nfs_reqq_lock);
/*
* If there was a successful reply and a tprintf msg.
* tprintf a response.
*/
if (!error && (rep->r_flags & R_TPRINTFMSG))
nfs_msg(rep->r_lwp, nmp->nm_mountp->mnt_stat.f_mntfromname,
"is alive again");
mrep = rep->r_mrep;
md = rep->r_md;
dpos = rep->r_dpos;
if (error)
goto nfsmout;
/*
* break down the rpc header and check if ok
*/
nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
if (*tl++ == rpc_msgdenied) {
if (*tl == rpc_mismatch)
error = EOPNOTSUPP;
else if ((nmp->nm_flag & NFSMNT_KERB) && *tl++ == rpc_autherr) {
if (!failed_auth) {
failed_auth++;
mheadend->m_next = NULL;
m_freem(mrep);
m_freem(rep->r_mreq);
goto kerbauth;
} else
error = EAUTH;
} else
error = EACCES;
m_freem(mrep);
goto nfsmout;
}
/*
* Grab any Kerberos verifier, otherwise just throw it away.
*/
verf_type = fxdr_unsigned(int, *tl++);
i = fxdr_unsigned(int32_t, *tl);
if ((nmp->nm_flag & NFSMNT_KERB) && verf_type == RPCAUTH_KERB4) {
error = nfs_savenickauth(nmp, cred, i, key, &md, &dpos, mrep);
if (error)
goto nfsmout;
} else if (i > 0)
nfsm_adv(nfsm_rndup(i));
nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
/* 0 == ok */
if (*tl == 0) {
nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
if (*tl != 0) {
error = fxdr_unsigned(int, *tl);
switch (error) {
case NFSERR_PERM:
error = EPERM;
break;
/*
* Lock a socket against others.
* Necessary for STREAM sockets to ensure you get an entire rpc request/reply
* and also to avoid race conditions between the processes with nfs requests
* in progress when a reconnect is necessary.
*/
static int
nfs_sndlock(struct nfsmount *nmp, struct nfsreq *rep)
{
struct lwp *l;
int timeo = 0;
bool catch_p = false;
int error = 0;
if (nmp->nm_flag & NFSMNT_SOFT)
timeo = nmp->nm_retry * nmp->nm_timeo;
if (nmp->nm_iflag & NFSMNT_DISMNTFORCE)
timeo = hz;
if (rep) {
l = rep->r_lwp;
if (rep->r_nmp->nm_flag & NFSMNT_INT)
catch_p = true;
} else
l = NULL;
mutex_enter(&nmp->nm_lock);
while ((nmp->nm_iflag & NFSMNT_SNDLOCK) != 0) {
if (rep && nfs_sigintr(rep->r_nmp, rep, l)) {
error = EINTR;
goto quit;
}
if (catch_p) {
error = cv_timedwait_sig(&nmp->nm_sndcv,
&nmp->nm_lock, timeo);
} else {
error = cv_timedwait(&nmp->nm_sndcv,
&nmp->nm_lock, timeo);
}
