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freebsd-skq/sys/nfsclient/nfs_socket.c

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/*
* 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. 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.
*
* @(#)nfs_socket.c 8.5 (Berkeley) 3/30/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Socket operations for use by nfs
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/vnode.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfsclient/nfs.h>
#include <nfs/xdr_subs.h>
#include <nfsclient/nfsm_subs.h>
#include <nfsclient/nfsmount.h>
#include <nfsclient/nfsnode.h>
#define TRUE 1
#define FALSE 0
/*
* Estimate rto for an nfs rpc sent via. an unreliable datagram.
* Use the mean and mean deviation of rtt for the appropriate type of rpc
* for the frequent rpcs and a default for the others.
* The justification for doing "other" this way is that these rpcs
* happen so infrequently that timer est. would probably be stale.
* Also, since many of these rpcs are
* non-idempotent, a conservative timeout is desired.
* getattr, lookup - A+2D
* read, write - A+4D
* other - nm_timeo
*/
#define NFS_RTO(n, t) \
((t) == 0 ? (n)->nm_timeo : \
((t) < 3 ? \
(((((n)->nm_srtt[t-1] + 3) >> 2) + (n)->nm_sdrtt[t-1] + 1) >> 1) : \
((((n)->nm_srtt[t-1] + 7) >> 3) + (n)->nm_sdrtt[t-1] + 1)))
#define NFS_SRTT(r) (r)->r_nmp->nm_srtt[proct[(r)->r_procnum] - 1]
#define NFS_SDRTT(r) (r)->r_nmp->nm_sdrtt[proct[(r)->r_procnum] - 1]
/*
* Defines which timer to use for the procnum.
* 0 - default
* 1 - getattr
* 2 - lookup
* 3 - read
* 4 - write
*/
static int proct[NFS_NPROCS] = {
0, 1, 0, 2, 1, 3, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0,
};
static int nfs_realign_test;
static int nfs_realign_count;
static int nfs_bufpackets = 4;
SYSCTL_DECL(_vfs_nfs);
SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_test, CTLFLAG_RW, &nfs_realign_test, 0, "");
SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_count, CTLFLAG_RW, &nfs_realign_count, 0, "");
SYSCTL_INT(_vfs_nfs, OID_AUTO, bufpackets, CTLFLAG_RW, &nfs_bufpackets, 0, "");
/*
* There is a congestion window for outstanding rpcs maintained per mount
* point. The cwnd size is adjusted in roughly the way that:
* Van Jacobson, Congestion avoidance and Control, In "Proceedings of
* SIGCOMM '88". ACM, August 1988.
* describes for TCP. The cwnd size is chopped in half on a retransmit timeout
* and incremented by 1/cwnd when each rpc reply is received and a full cwnd
* of rpcs is in progress.
* (The sent count and cwnd are scaled for integer arith.)
* Variants of "slow start" were tried and were found to be too much of a
* performance hit (ave. rtt 3 times larger),
* I suspect due to the large rtt that nfs rpcs have.
*/
#define NFS_CWNDSCALE 256
#define NFS_MAXCWND (NFS_CWNDSCALE * 32)
#define NFS_NBACKOFF 8
static int nfs_backoff[NFS_NBACKOFF] = { 2, 4, 8, 16, 32, 64, 128, 256, };
struct callout_handle nfs_timer_handle;
static int nfs_msg(struct thread *, char *, char *);
static int nfs_rcvlock(struct nfsreq *);
static void nfs_rcvunlock(struct nfsreq *);
static void nfs_realign(struct mbuf **pm, int hsiz);
static int nfs_receive(struct nfsreq *rep, struct sockaddr **aname,
struct mbuf **mp);
static int nfs_reply(struct nfsreq *);
static void nfs_softterm(struct nfsreq *rep);
static int nfs_reconnect(struct nfsreq *rep);
/*
* Initialize sockets and congestion for a new NFS connection.
* We do not free the sockaddr if error.
*/
int
nfs_connect(struct nfsmount *nmp, struct nfsreq *rep)
{
struct socket *so;
int s, error, rcvreserve, sndreserve;
int pktscale;
struct sockaddr *saddr;
struct sockaddr_in *sin;
struct thread *td = &thread0; /* only used for socreate and sobind */
nmp->nm_so = (struct socket *)0;
saddr = nmp->nm_nam;
error = socreate(saddr->sa_family, &nmp->nm_so, nmp->nm_sotype,
nmp->nm_soproto, nmp->nm_cred, td);
if (error)
goto bad;
so = nmp->nm_so;
nmp->nm_soflags = so->so_proto->pr_flags;
/*
* Some servers require that the client port be a reserved port number.
*/
if (saddr->sa_family == AF_INET && (nmp->nm_flag & NFSMNT_RESVPORT)) {
struct sockopt sopt;
int ip;
struct sockaddr_in ssin;
bzero(&sopt, sizeof sopt);
ip = IP_PORTRANGE_LOW;
sopt.sopt_dir = SOPT_SET;
sopt.sopt_level = IPPROTO_IP;
sopt.sopt_name = IP_PORTRANGE;
sopt.sopt_val = (void *)&ip;
sopt.sopt_valsize = sizeof(ip);
sopt.sopt_td = NULL;
error = sosetopt(so, &sopt);
if (error)
goto bad;
bzero(&ssin, sizeof ssin);
sin = &ssin;
sin->sin_len = sizeof (struct sockaddr_in);
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = INADDR_ANY;
sin->sin_port = htons(0);
error = sobind(so, (struct sockaddr *)sin, td);
if (error)
goto bad;
bzero(&sopt, sizeof sopt);
ip = IP_PORTRANGE_DEFAULT;
sopt.sopt_dir = SOPT_SET;
sopt.sopt_level = IPPROTO_IP;
sopt.sopt_name = IP_PORTRANGE;
sopt.sopt_val = (void *)&ip;
sopt.sopt_valsize = sizeof(ip);
sopt.sopt_td = NULL;
error = sosetopt(so, &sopt);
if (error)
goto bad;
}
/*
* Protocols that do not require connections may be optionally left
* unconnected for servers that reply from a port other than NFS_PORT.
*/
if (nmp->nm_flag & NFSMNT_NOCONN) {
if (nmp->nm_soflags & PR_CONNREQUIRED) {
error = ENOTCONN;
goto bad;
}
} else {
error = soconnect(so, nmp->nm_nam, td);
if (error)
goto bad;
/*
* Wait for the connection to complete. Cribbed from the
* connect system call but with the wait timing out so
* that interruptible mounts don't hang here for a long time.
*/
s = splnet();
while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
(void) tsleep((caddr_t)&so->so_timeo, PSOCK,
"nfscon", 2 * hz);
if ((so->so_state & SS_ISCONNECTING) &&
so->so_error == 0 && rep &&
(error = nfs_sigintr(nmp, rep,
(rep->r_td ? rep->r_td->td_proc : NULL))) != 0){
so->so_state &= ~SS_ISCONNECTING;
splx(s);
goto bad;
}
}
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
splx(s);
goto bad;
}
splx(s);
}
so->so_rcv.sb_timeo = 5 * hz;
so->so_snd.sb_timeo = 5 * hz;
/*
* Get buffer reservation size from sysctl, but impose reasonable
* limits.
*/
pktscale = nfs_bufpackets;
if (pktscale < 2)
pktscale = 2;
if (pktscale > 64)
pktscale = 64;
if (nmp->nm_sotype == SOCK_DGRAM) {
sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR) * pktscale;
rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
NFS_MAXPKTHDR) * pktscale;
} else if (nmp->nm_sotype == SOCK_SEQPACKET) {
sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR) * pktscale;
rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
NFS_MAXPKTHDR) * pktscale;
} else {
if (nmp->nm_sotype != SOCK_STREAM)
panic("nfscon sotype");
if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
struct sockopt sopt;
int val;
bzero(&sopt, sizeof sopt);
sopt.sopt_level = SOL_SOCKET;
sopt.sopt_name = SO_KEEPALIVE;
sopt.sopt_val = &val;
sopt.sopt_valsize = sizeof val;
val = 1;
sosetopt(so, &sopt);
}
if (so->so_proto->pr_protocol == IPPROTO_TCP) {
struct sockopt sopt;
int val;
bzero(&sopt, sizeof sopt);
sopt.sopt_level = IPPROTO_TCP;
sopt.sopt_name = TCP_NODELAY;
sopt.sopt_val = &val;
sopt.sopt_valsize = sizeof val;
val = 1;
sosetopt(so, &sopt);
}
sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR +
sizeof (u_int32_t)) * pktscale;
rcvreserve = (nmp->nm_rsize + NFS_MAXPKTHDR +
sizeof (u_int32_t)) * pktscale;
}
error = soreserve(so, sndreserve, rcvreserve);
if (error)
goto bad;
so->so_rcv.sb_flags |= SB_NOINTR;
so->so_snd.sb_flags |= SB_NOINTR;
/* Initialize other non-zero congestion variables */
nmp->nm_srtt[0] = nmp->nm_srtt[1] = nmp->nm_srtt[2] =
nmp->nm_srtt[3] = (NFS_TIMEO << 3);
nmp->nm_sdrtt[0] = nmp->nm_sdrtt[1] = nmp->nm_sdrtt[2] =
nmp->nm_sdrtt[3] = 0;
nmp->nm_cwnd = NFS_MAXCWND / 2; /* Initial send window */
nmp->nm_sent = 0;
nmp->nm_timeouts = 0;
return (0);
bad:
nfs_disconnect(nmp);
return (error);
}
/*
* Reconnect routine:
* Called when a connection is broken on a reliable protocol.
* - clean up the old socket
* - nfs_connect() again
* - set R_MUSTRESEND for all outstanding requests on mount point
* If this fails the mount point is DEAD!
* nb: Must be called with the nfs_sndlock() set on the mount point.
*/
static int
nfs_reconnect(struct nfsreq *rep)
{
struct nfsreq *rp;
struct nfsmount *nmp = rep->r_nmp;
int error;
nfs_disconnect(nmp);
while ((error = nfs_connect(nmp, rep)) != 0) {
if (error == EINTR || error == ERESTART)
return (EINTR);
(void) tsleep((caddr_t)&lbolt, PSOCK, "nfscon", 0);
}
/*
* Loop through outstanding request list and fix up all requests
* on old socket.
*/
TAILQ_FOREACH(rp, &nfs_reqq, r_chain) {
if (rp->r_nmp == nmp)
rp->r_flags |= R_MUSTRESEND;
}
return (0);
}
/*
* NFS disconnect. Clean up and unlink.
*/
void
nfs_disconnect(struct nfsmount *nmp)
{
struct socket *so;
if (nmp->nm_so) {
so = nmp->nm_so;
nmp->nm_so = (struct socket *)0;
soshutdown(so, 2);
soclose(so);
}
}
void
nfs_safedisconnect(struct nfsmount *nmp)
{
struct nfsreq dummyreq;
bzero(&dummyreq, sizeof(dummyreq));
dummyreq.r_nmp = nmp;
nfs_rcvlock(&dummyreq);
nfs_disconnect(nmp);
nfs_rcvunlock(&dummyreq);
}
/*
* This is the nfs send routine. For connection based socket types, it
* must be called with an nfs_sndlock() on the socket.
* - return EINTR if the RPC is terminated, 0 otherwise
* - set R_MUSTRESEND if the send fails for any reason
* - do any cleanup required by recoverable socket errors (?)
*/
int
nfs_send(struct socket *so, struct sockaddr *nam, struct mbuf *top,
struct nfsreq *rep)
{
struct sockaddr *sendnam;
int error, soflags, flags;
KASSERT(rep, ("nfs_send: called with rep == NULL"));
if (rep->r_flags & R_SOFTTERM) {
m_freem(top);
return (EINTR);
}
if ((so = rep->r_nmp->nm_so) == NULL) {
rep->r_flags |= R_MUSTRESEND;
m_freem(top);
return (0);
}
rep->r_flags &= ~R_MUSTRESEND;
soflags = rep->r_nmp->nm_soflags;
if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
sendnam = (struct sockaddr *)0;
else
sendnam = nam;
if (so->so_type == SOCK_SEQPACKET)
flags = MSG_EOR;
else
flags = 0;
error = so->so_proto->pr_usrreqs->pru_sosend(so, sendnam, 0, top, 0,
flags, curthread /*XXX*/);
if (error == ENOBUFS && so->so_type == SOCK_DGRAM) {
error = 0;
rep->r_flags |= R_MUSTRESEND;
}
if (error) {
log(LOG_INFO, "nfs send error %d for server %s\n", error,
rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
/*
* Deal with errors for the client side.
*/
if (rep->r_flags & R_SOFTTERM)
error = EINTR;
else
rep->r_flags |= R_MUSTRESEND;
/*
* Handle any recoverable (soft) socket errors here. (?)
*/
if (error != EINTR && error != ERESTART &&
error != EWOULDBLOCK && error != EPIPE)
error = 0;
}
return (error);
}
/*
* 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 sockaddr **aname, struct mbuf **mp)
{
struct socket *so;
struct uio auio;
struct iovec aio;
struct mbuf *m;
struct mbuf *control;
u_int32_t len;
struct sockaddr **getnam;
int error, sotype, rcvflg;
struct thread *td = curthread; /* XXX */
/*
* Set up arguments for soreceive()
*/
*mp = (struct mbuf *)0;
*aname = (struct sockaddr *)0;
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);
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);
return (EINTR);
}
so = rep->r_nmp->nm_so;
if (!so) {
error = nfs_reconnect(rep);
if (error) {
nfs_sndunlock(rep);
return (error);
}
goto tryagain;
}
while (rep->r_flags & R_MUSTRESEND) {
m = m_copym(rep->r_mreq, 0, M_COPYALL, M_TRYWAIT);
nfsstats.rpcretries++;
error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
if (error) {
if (error == EINTR || error == ERESTART ||
(error = nfs_reconnect(rep)) != 0) {
nfs_sndunlock(rep);
return (error);
}
goto tryagain;
}
}
nfs_sndunlock(rep);
if (sotype == SOCK_STREAM) {
aio.iov_base = (caddr_t) &len;
aio.iov_len = sizeof(u_int32_t);
auio.uio_iov = &aio;
auio.uio_iovcnt = 1;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_READ;
auio.uio_offset = 0;
auio.uio_resid = sizeof(u_int32_t);
auio.uio_td = td;
do {
rcvflg = MSG_WAITALL;
error = so->so_proto->pr_usrreqs->pru_soreceive
(so, (struct sockaddr **)0, &auio,
(struct mbuf **)0, (struct mbuf **)0,
&rcvflg);
if (error == EWOULDBLOCK && rep) {
if (rep->r_flags & R_SOFTTERM)
return (EINTR);
}
} 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 (%d/%d) from nfs server %s\n",
(int)(sizeof(u_int32_t) - auio.uio_resid),
(int)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_proto->pr_usrreqs->pru_soreceive
(so, (struct sockaddr **)0,
&auio, mp, (struct mbuf **)0, &rcvflg);
} while (error == EWOULDBLOCK || error == EINTR ||
error == ERESTART);
if (!error && auio.uio_resid > 0) {
if (len != auio.uio_resid)
log(LOG_INFO,
"short receive (%d/%d) from nfs server %s\n",
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 */
auio.uio_td = td;
do {
rcvflg = 0;
error = so->so_proto->pr_usrreqs->pru_soreceive
(so, (struct sockaddr **)0,
&auio, mp, &control, &rcvflg);
if (control)
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 = (struct mbuf *)0;
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);
if (!error)
error = nfs_reconnect(rep);
if (!error)
goto tryagain;
else
nfs_sndunlock(rep);
}
} else {
if ((so = rep->r_nmp->nm_so) == NULL)
return (EACCES);
if (so->so_state & SS_ISCONNECTED)
getnam = (struct sockaddr **)0;
else
getnam = aname;
auio.uio_resid = len = 1000000;
auio.uio_td = td;
do {
rcvflg = 0;
error = so->so_proto->pr_usrreqs->pru_soreceive
(so, getnam, &auio, mp,
(struct mbuf **)0, &rcvflg);
if (error == EWOULDBLOCK &&
(rep->r_flags & R_SOFTTERM))
return (EINTR);
} while (error == EWOULDBLOCK);
len -= auio.uio_resid;
}
if (error) {
m_freem(*mp);
*mp = (struct mbuf *)0;
}
/*
* Search for any mbufs that are not a multiple of 4 bytes long
* or with m_data not longword aligned.
* These could cause pointer alignment problems, so copy them to
* well aligned mbufs.
*/
nfs_realign(mp, 5 * NFSX_UNSIGNED);
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 nfsreq *rep;
struct nfsmount *nmp = myrep->r_nmp;
int32_t t1;
struct mbuf *mrep, *md;
struct sockaddr *nam;
u_int32_t rxid, *tl;
caddr_t dpos;
int error;
/*
* 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.
* If nfs_rcvlock() returns EALREADY, that means that
* the reply has already been recieved by another
* process and we can return immediately. In this
* case, the lock is not taken to avoid races with
* other processes.
*/
error = nfs_rcvlock(myrep);
if (error == EALREADY)
return (0);
if (error)
return (error);
/*
* Get the next Rpc reply off the socket
*/
error = nfs_receive(myrep, &nam, &mrep);
nfs_rcvunlock(myrep);
if (error) {
/*
* Ignore routing errors on connectionless protocols??
*/
if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
nmp->nm_so->so_error = 0;
if (myrep->r_flags & R_GETONEREP)
return (0);
continue;
}
return (error);
}
if (nam)
FREE(nam, M_SONAME);
/*
* Get the xid and check that it is an rpc reply
*/
md = mrep;
dpos = mtod(md, caddr_t);
tl = nfsm_dissect(u_int32_t *, 2 * NFSX_UNSIGNED);
rxid = *tl++;
if (*tl != rpc_reply) {
nfsstats.rpcinvalid++;
m_freem(mrep);
nfsmout:
if (myrep->r_flags & R_GETONEREP)
return (0);
continue;
}
/*
* Loop through the request list to match up the reply
* Iff no match, just drop the datagram
*/
TAILQ_FOREACH(rep, &nfs_reqq, r_chain) {
if (rep->r_mrep == NULL && rxid == rep->r_xid) {
/* Found it.. */
rep->r_mrep = mrep;
rep->r_md = md;
rep->r_dpos = dpos;
/*
* 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;
}
if (rep->r_flags & R_SENT) {
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;
}
}
/*
* 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);
}
if (myrep->r_flags & R_GETONEREP)
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
*/
/* XXX overloaded before */
#define NQ_TRYLATERDEL 15 /* Initial try later delay (sec) */
int
nfs_request(struct vnode *vp, struct mbuf *mrest, int procnum,
struct thread *td, struct ucred *cred, struct mbuf **mrp,
struct mbuf **mdp, caddr_t *dposp)
{
struct mbuf *mrep, *m2;
struct nfsreq *rep;
u_int32_t *tl;
int i;
struct nfsmount *nmp;
struct mbuf *m, *md, *mheadend;
time_t waituntil;
caddr_t dpos;
int s, error = 0, mrest_len, auth_len, auth_type;
int trylater_delay = NQ_TRYLATERDEL, trylater_cnt = 0;
u_int32_t xid;
/* Reject requests while attempting to unmount. */
if (vp->v_mount->mnt_kern_flag & MNTK_UNMOUNT) {
m_freem(mrest);
return (ESTALE);
}
nmp = VFSTONFS(vp->v_mount);
MALLOC(rep, struct nfsreq *, sizeof(struct nfsreq), M_NFSREQ, M_WAITOK);
rep->r_nmp = nmp;
rep->r_vp = vp;
rep->r_td = td;
rep->r_procnum = procnum;
i = 0;
m = mrest;
while (m) {
i += m->m_len;
m = m->m_next;
}
mrest_len = i;
/*
* Get the RPC header with authorization.
*/
auth_type = RPCAUTH_UNIX;
if (cred->cr_ngroups < 1)
panic("nfsreq nogrps");
auth_len = ((((cred->cr_ngroups - 1) > nmp->nm_numgrps) ?
nmp->nm_numgrps : (cred->cr_ngroups - 1)) << 2) +
5 * NFSX_UNSIGNED;
m = nfsm_rpchead(cred, nmp->nm_flag, procnum, auth_type, auth_len,
mrest, mrest_len, &mheadend, &xid);
/*
* For stream protocols, insert a Sun RPC Record Mark.
*/
if (nmp->nm_sotype == SOCK_STREAM) {
M_PREPEND(m, NFSX_UNSIGNED, M_TRYWAIT);
*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 (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 = splsoftclock();
TAILQ_INSERT_TAIL(&nfs_reqq, rep, r_chain);
/*
* 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(rep);
if (!error) {
m2 = m_copym(m, 0, M_COPYALL, M_TRYWAIT);
error = nfs_send(nmp->nm_so, nmp->nm_nam, m2, rep);
if (nmp->nm_soflags & PR_CONNREQUIRED)
nfs_sndunlock(rep);
}
if (!error && (rep->r_flags & R_MUSTRESEND) == 0) {
nmp->nm_sent += NFS_CWNDSCALE;
rep->r_flags |= R_SENT;
}
} else {
splx(s);
rep->r_rtt = -1;
}
/*
* Wait for the reply from our send or the timer's.
*/
if (!error || error == EPIPE)
error = nfs_reply(rep);
/*
* RPC done, unlink the request.
*/
s = splsoftclock();
TAILQ_REMOVE(&nfs_reqq, rep, r_chain);
splx(s);
/*
* Decrement the outstanding request count.
*/
if (rep->r_flags & R_SENT) {
rep->r_flags &= ~R_SENT; /* paranoia */
nmp->nm_sent -= NFS_CWNDSCALE;
}
/*
* If there was a successful reply and a tprintf msg.
* tprintf a response.
*/
if (!error && (rep->r_flags & R_TPRINTFMSG))
nfs_msg(rep->r_td, nmp->nm_mountp->mnt_stat.f_mntfromname,
"is alive again");
mrep = rep->r_mrep;
md = rep->r_md;
dpos = rep->r_dpos;
if (error) {
m_freem(rep->r_mreq);
free((caddr_t)rep, M_NFSREQ);
return (error);
}
/*
* break down the rpc header and check if ok
*/
tl = nfsm_dissect(u_int32_t *, 3 * NFSX_UNSIGNED);
if (*tl++ == rpc_msgdenied) {
if (*tl == rpc_mismatch)
error = EOPNOTSUPP;
else
error = EACCES;
m_freem(mrep);
m_freem(rep->r_mreq);
free((caddr_t)rep, M_NFSREQ);
return (error);
}
/*
* Just throw away any verifyer (ie: kerberos etc).
*/
i = fxdr_unsigned(int, *tl++); /* verf type */
i = fxdr_unsigned(int32_t, *tl); /* len */
if (i > 0)
nfsm_adv(nfsm_rndup(i));
tl = nfsm_dissect(u_int32_t *, NFSX_UNSIGNED);
/* 0 == ok */
if (*tl == 0) {
tl = nfsm_dissect(u_int32_t *, NFSX_UNSIGNED);
if (*tl != 0) {
error = fxdr_unsigned(int, *tl);
if ((nmp->nm_flag & NFSMNT_NFSV3) &&
error == NFSERR_TRYLATER) {
m_freem(mrep);
error = 0;
waituntil = time_second + trylater_delay;
while (time_second < waituntil)
(void) tsleep((caddr_t)&lbolt,
PSOCK, "nqnfstry", 0);
trylater_delay *= nfs_backoff[trylater_cnt];
if (trylater_cnt < NFS_NBACKOFF - 1)
trylater_cnt++;
goto tryagain;
}
/*
* If the File Handle was stale, invalidate the
* lookup cache, just in case.
*/
if (error == ESTALE)
cache_purge(vp);
if (nmp->nm_flag & NFSMNT_NFSV3) {
*mrp = mrep;
*mdp = md;
*dposp = dpos;
error |= NFSERR_RETERR;
} else
m_freem(mrep);
m_freem(rep->r_mreq);
free((caddr_t)rep, M_NFSREQ);
return (error);
}
*mrp = mrep;
*mdp = md;
*dposp = dpos;
m_freem(rep->r_mreq);
FREE((caddr_t)rep, M_NFSREQ);
return (0);
}
m_freem(mrep);
error = EPROTONOSUPPORT;
nfsmout:
m_freem(rep->r_mreq);
free((caddr_t)rep, M_NFSREQ);
return (error);
}
/*
* Nfs timer routine
* Scan the nfsreq list and retranmit any requests that have timed out
* To avoid retransmission attempts on STREAM sockets (in the future) make
* sure to set the r_retry field to 0 (implies nm_retry == 0).
*/
void
nfs_timer(void *arg)
{
struct nfsreq *rep;
struct mbuf *m;
struct socket *so;
struct nfsmount *nmp;
int timeo;
int s, error;
struct thread *td;
td = &thread0; /* XXX for credentials, may break if sleep */
s = splnet();
TAILQ_FOREACH(rep, &nfs_reqq, r_chain) {
nmp = rep->r_nmp;
if (rep->r_mrep || (rep->r_flags & R_SOFTTERM))
continue;
if (nfs_sigintr(nmp, rep,
(rep->r_td ? rep->r_td->td_proc : NULL))) {
nfs_softterm(rep);
continue;
}
if (rep->r_rtt >= 0) {
rep->r_rtt++;
if (nmp->nm_flag & NFSMNT_DUMBTIMR)
timeo = nmp->nm_timeo;
else
timeo = NFS_RTO(nmp, proct[rep->r_procnum]);
if (nmp->nm_timeouts > 0)
timeo *= nfs_backoff[nmp->nm_timeouts - 1];
if (rep->r_rtt <= timeo)
continue;
if (nmp->nm_timeouts < NFS_NBACKOFF)
nmp->nm_timeouts++;
}
/*
* Check for server not responding
*/
if ((rep->r_flags & R_TPRINTFMSG) == 0 &&
rep->r_rexmit > nmp->nm_deadthresh) {
char buf[40];
sprintf(buf, "not responding %d > %d",
rep->r_rexmit, nmp->nm_deadthresh);
nfs_msg(rep->r_td,
nmp->nm_mountp->mnt_stat.f_mntfromname,
buf /* "not responding" */);
rep->r_flags |= R_TPRINTFMSG;
}
if (rep->r_rexmit >= rep->r_retry) { /* too many */
nfsstats.rpctimeouts++;
nfs_softterm(rep);
continue;
}
if (nmp->nm_sotype != SOCK_DGRAM) {
if (++rep->r_rexmit > NFS_MAXREXMIT)
rep->r_rexmit = NFS_MAXREXMIT;
continue;
}
if ((so = nmp->nm_so) == NULL)
continue;
/*
* If there is enough space and the window allows..
* Resend it
* Set r_rtt to -1 in case we fail to send it now.
*/
rep->r_rtt = -1;
if (sbspace(&so->so_snd) >= rep->r_mreq->m_pkthdr.len &&
((nmp->nm_flag & NFSMNT_DUMBTIMR) ||
(rep->r_flags & R_SENT) ||
nmp->nm_sent < nmp->nm_cwnd) &&
(m = m_copym(rep->r_mreq, 0, M_COPYALL, M_DONTWAIT))){
if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
error = (*so->so_proto->pr_usrreqs->pru_send)
(so, 0, m, (struct sockaddr *)0,
(struct mbuf *)0, td);
else
error = (*so->so_proto->pr_usrreqs->pru_send)
(so, 0, m, nmp->nm_nam, (struct mbuf *)0,
td);
if (error) {
if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
so->so_error = 0;
} else {
/*
* Iff first send, start timing
* else turn timing off, backoff timer
* and divide congestion window by 2.
*/
if (rep->r_flags & R_SENT) {
rep->r_flags &= ~R_TIMING;
if (++rep->r_rexmit > NFS_MAXREXMIT)
rep->r_rexmit = NFS_MAXREXMIT;
nmp->nm_cwnd >>= 1;
if (nmp->nm_cwnd < NFS_CWNDSCALE)
nmp->nm_cwnd = NFS_CWNDSCALE;
nfsstats.rpcretries++;
} else {
rep->r_flags |= R_SENT;
nmp->nm_sent += NFS_CWNDSCALE;
}
rep->r_rtt = 0;
}
}
}
splx(s);
nfs_timer_handle = timeout(nfs_timer, (void *)0, nfs_ticks);
}
/*
* Mark all of an nfs mount's outstanding requests with R_SOFTTERM and
* wait for all requests to complete. This is used by forced unmounts
* to terminate any outstanding RPCs.
*/
int
nfs_nmcancelreqs(nmp)
struct nfsmount *nmp;
{
struct nfsreq *req;
int i, s;
s = splnet();
TAILQ_FOREACH(req, &nfs_reqq, r_chain) {
if (nmp != req->r_nmp || req->r_mrep != NULL ||
(req->r_flags & R_SOFTTERM))
continue;
nfs_softterm(req);
}
splx(s);
for (i = 0; i < 30; i++) {
s = splnet();
TAILQ_FOREACH(req, &nfs_reqq, r_chain) {
if (nmp == req->r_nmp)
break;
}
splx(s);
if (req == NULL)
return (0);
tsleep(&lbolt, PSOCK, "nfscancel", 0);
}
return (EBUSY);
}
/*
* Flag a request as being about to terminate (due to NFSMNT_INT/NFSMNT_SOFT).
* The nm_send count is decremented now to avoid deadlocks when the process in
* soreceive() hasn't yet managed to send its own request.
*/
static void
nfs_softterm(struct nfsreq *rep)
{
rep->r_flags |= R_SOFTTERM;
if (rep->r_flags & R_SENT) {
rep->r_nmp->nm_sent -= NFS_CWNDSCALE;
rep->r_flags &= ~R_SENT;
}
}
/*
* Test for a termination condition pending on the process.
* This is used for NFSMNT_INT mounts.
*/
int
nfs_sigintr(struct nfsmount *nmp, struct nfsreq *rep, struct proc *p)
{
sigset_t tmpset;
if (rep && (rep->r_flags & R_SOFTTERM))
return (EINTR);
/* Terminate all requests while attempting to unmount. */
if (nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNT)
return (EINTR);
if (!(nmp->nm_flag & NFSMNT_INT))
return (0);
if (p == NULL)
return (0);
tmpset = p->p_siglist;
SIGSETNAND(tmpset, p->p_sigmask);
SIGSETNAND(tmpset, p->p_sigignore);
if (SIGNOTEMPTY(p->p_siglist) && NFSINT_SIGMASK(tmpset))
return (EINTR);
return (0);
}
/*
* 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.
*/
int
nfs_sndlock(struct nfsreq *rep)
{
int *statep = &rep->r_nmp->nm_state;
struct thread *td;
int slpflag = 0, slptimeo = 0;
if (rep) {
td = rep->r_td;
if (rep->r_nmp->nm_flag & NFSMNT_INT)
slpflag = PCATCH;
} else
td = (struct thread *)0;
while (*statep & NFSSTA_SNDLOCK) {
if (nfs_sigintr(rep->r_nmp, rep, td ? td->td_proc : NULL))
return (EINTR);
*statep |= NFSSTA_WANTSND;
(void) tsleep((caddr_t)statep, slpflag | (PZERO - 1),
"nfsndlck", slptimeo);
if (slpflag == PCATCH) {
slpflag = 0;
slptimeo = 2 * hz;
}
}
*statep |= NFSSTA_SNDLOCK;
return (0);
}
/*
* Unlock the stream socket for others.
*/
void
nfs_sndunlock(struct nfsreq *rep)
{
int *statep = &rep->r_nmp->nm_state;
if ((*statep & NFSSTA_SNDLOCK) == 0)
panic("nfs sndunlock");
*statep &= ~NFSSTA_SNDLOCK;
if (*statep & NFSSTA_WANTSND) {
*statep &= ~NFSSTA_WANTSND;
wakeup((caddr_t)statep);
}
}
static int
nfs_rcvlock(struct nfsreq *rep)
{
int *statep = &rep->r_nmp->nm_state;
int slpflag, slptimeo = 0;
if (rep->r_nmp->nm_flag & NFSMNT_INT)
slpflag = PCATCH;
else
slpflag = 0;
while (*statep & NFSSTA_RCVLOCK) {
if (nfs_sigintr(rep->r_nmp, rep,
(rep->r_td ? rep->r_td->td_proc : NULL)))
return (EINTR);
*statep |= NFSSTA_WANTRCV;
(void) tsleep((caddr_t)statep, slpflag | (PZERO - 1), "nfsrcvlk",
slptimeo);
/*
* If our reply was recieved while we were sleeping,
* then just return without taking the lock to avoid a
* situation where a single iod could 'capture' the
* recieve lock.
*/
if (rep->r_mrep != NULL)
return (EALREADY);
if (slpflag == PCATCH) {
slpflag = 0;
slptimeo = 2 * hz;
}
}
/* Always fail if our request has been cancelled. */
if (rep != NULL && (rep->r_flags & R_SOFTTERM))
return (EINTR);
*statep |= NFSSTA_RCVLOCK;
return (0);
}
/*
* Unlock the stream socket for others.
*/
static void
nfs_rcvunlock(struct nfsreq *rep)
{
int *statep = &rep->r_nmp->nm_state;
if ((*statep & NFSSTA_RCVLOCK) == 0)
panic("nfs rcvunlock");
*statep &= ~NFSSTA_RCVLOCK;
if (*statep & NFSSTA_WANTRCV) {
*statep &= ~NFSSTA_WANTRCV;
wakeup((caddr_t)statep);
}
}
/*
* nfs_realign:
*
* 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.realign_count and realign_test to check this.
*/
static void
nfs_realign(struct mbuf **pm, int hsiz)
{
struct mbuf *m;
struct mbuf *n = NULL;
int off = 0;
++nfs_realign_test;
while ((m = *pm) != NULL) {
if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3)) {
MGET(n, M_TRYWAIT, MT_DATA);
if (m->m_len >= MINCLSIZE) {
MCLGET(n, M_TRYWAIT);
}
n->m_len = 0;
break;
}
pm = &m->m_next;
}
/*
* If n is non-NULL, loop on m copying data, then replace the
* portion of the chain that had to be realigned.
*/
if (n != NULL) {
++nfs_realign_count;
while (m) {
m_copyback(n, off, m->m_len, mtod(m, caddr_t));
off += m->m_len;
m = m->m_next;
}
m_freem(*pm);
*pm = n;
}
}
static int
nfs_msg(struct thread *td, char *server, char *msg)
{
tprintf(td ? td->td_proc : NULL, LOG_INFO,
"nfs server %s: %s\n", server, msg);
return (0);
}
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