freebsd-dev/sys/nfsserver/nfs_srvkrpc.c
Doug Rabson 36b83ac1b0 Use the remote address for access control, not the local address. This fixes
the nfsd problems that some people have with the new code.

Add support for the vfs.nfsrv.nfs_privport sysctl which denies access unless
the client is using a port number less than 1024. Not really sure if this is
particularly useful since it doesn't add any real security.
2008-11-13 14:36:52 +00:00

614 lines
15 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_syscalls.c 8.5 (Berkeley) 3/30/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet6.h"
#include "opt_kgssapi.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/namei.h>
#include <sys/fcntl.h>
#include <sys/lockf.h>
#include <sys/eventhandler.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#ifdef INET6
#include <net/if.h>
#include <netinet6/in6_var.h>
#endif
#include <rpc/rpc.h>
#include <rpc/rpcsec_gss.h>
#include <rpc/replay.h>
#include <nfs/xdr_subs.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfsserver/nfs.h>
#include <nfsserver/nfsm_subs.h>
#include <nfsserver/nfsrvcache.h>
#include <nfsserver/nfs_fha.h>
#ifndef NFS_LEGACYRPC
static MALLOC_DEFINE(M_NFSSVC, "nfss_srvsock", "Nfs server structure");
MALLOC_DEFINE(M_NFSRVDESC, "nfss_srvdesc", "NFS server socket descriptor");
MALLOC_DEFINE(M_NFSD, "nfss_daemon", "Nfs server daemon structure");
#define TRUE 1
#define FALSE 0
SYSCTL_DECL(_vfs_nfsrv);
SVCPOOL *nfsrv_pool;
int nfsd_waiting = 0;
int nfsrv_numnfsd = 0;
static int nfs_realign_test;
static int nfs_realign_count;
struct callout nfsrv_callout;
static eventhandler_tag nfsrv_nmbclusters_tag;
static int nfs_privport = 0;
SYSCTL_INT(_vfs_nfsrv, NFS_NFSPRIVPORT, nfs_privport, CTLFLAG_RW,
&nfs_privport, 0,
"Only allow clients using a privileged port");
SYSCTL_INT(_vfs_nfsrv, OID_AUTO, gatherdelay, CTLFLAG_RW,
&nfsrvw_procrastinate, 0,
"Delay value for write gathering");
SYSCTL_INT(_vfs_nfsrv, OID_AUTO, gatherdelay_v3, CTLFLAG_RW,
&nfsrvw_procrastinate_v3, 0,
"Delay in seconds for NFSv3 write gathering");
SYSCTL_INT(_vfs_nfsrv, OID_AUTO, realign_test, CTLFLAG_RW,
&nfs_realign_test, 0, "");
SYSCTL_INT(_vfs_nfsrv, OID_AUTO, realign_count, CTLFLAG_RW,
&nfs_realign_count, 0, "");
static int nfssvc_addsock(struct file *, struct thread *);
static int nfssvc_nfsd(struct thread *, struct nfsd_nfsd_args *);
extern u_long sb_max_adj;
int32_t (*nfsrv3_procs[NFS_NPROCS])(struct nfsrv_descript *nd,
struct nfssvc_sock *slp, struct mbuf **mreqp) = {
nfsrv_null,
nfsrv_getattr,
nfsrv_setattr,
nfsrv_lookup,
nfsrv3_access,
nfsrv_readlink,
nfsrv_read,
nfsrv_write,
nfsrv_create,
nfsrv_mkdir,
nfsrv_symlink,
nfsrv_mknod,
nfsrv_remove,
nfsrv_rmdir,
nfsrv_rename,
nfsrv_link,
nfsrv_readdir,
nfsrv_readdirplus,
nfsrv_statfs,
nfsrv_fsinfo,
nfsrv_pathconf,
nfsrv_commit,
nfsrv_noop
};
/*
* NFS server system calls
*/
/*
* Nfs server psuedo system call for the nfsd's
* Based on the flag value it either:
* - adds a socket to the selection list
* - remains in the kernel as an nfsd
* - remains in the kernel as an nfsiod
* For INET6 we suppose that nfsd provides only IN6P_IPV6_V6ONLY sockets
* and that mountd provides
* - sockaddr with no IPv4-mapped addresses
* - mask for both INET and INET6 families if there is IPv4-mapped overlap
*/
#ifndef _SYS_SYSPROTO_H_
struct nfssvc_args {
int flag;
caddr_t argp;
};
#endif
int
nfssvc(struct thread *td, struct nfssvc_args *uap)
{
struct file *fp;
struct nfsd_addsock_args addsockarg;
struct nfsd_nfsd_args nfsdarg;
int error;
KASSERT(!mtx_owned(&Giant), ("nfssvc(): called with Giant"));
error = priv_check(td, PRIV_NFS_DAEMON);
if (error)
return (error);
if (uap->flag & NFSSVC_ADDSOCK) {
error = copyin(uap->argp, (caddr_t)&addsockarg,
sizeof(addsockarg));
if (error)
return (error);
if ((error = fget(td, addsockarg.sock, &fp)) != 0)
return (error);
if (fp->f_type != DTYPE_SOCKET) {
fdrop(fp, td);
return (error); /* XXXRW: Should be EINVAL? */
}
error = nfssvc_addsock(fp, td);
fdrop(fp, td);
} else if (uap->flag & NFSSVC_OLDNFSD) {
error = nfssvc_nfsd(td, NULL);
} else if (uap->flag & NFSSVC_NFSD) {
if (!uap->argp)
return (EINVAL);
error = copyin(uap->argp, (caddr_t)&nfsdarg,
sizeof(nfsdarg));
if (error)
return (error);
error = nfssvc_nfsd(td, &nfsdarg);
} else {
error = ENXIO;
}
if (error == EINTR || error == ERESTART)
error = 0;
return (error);
}
/*
* Generate the rpc reply header
* siz arg. is used to decide if adding a cluster is worthwhile
*/
struct mbuf *
nfs_rephead(int siz, struct nfsrv_descript *nd, int err,
struct mbuf **mbp, caddr_t *bposp)
{
u_int32_t *tl;
struct mbuf *mreq;
caddr_t bpos;
struct mbuf *mb;
if (err == EBADRPC)
return (NULL);
nd->nd_repstat = err;
if (err && (nd->nd_flag & ND_NFSV3) == 0) /* XXX recheck */
siz = 0;
MGET(mreq, M_WAIT, MT_DATA);
/*
* If this is a big reply, use a cluster
*/
mreq->m_len = 0;
if (siz >= MINCLSIZE) {
MCLGET(mreq, M_WAIT);
}
mb = mreq;
bpos = mtod(mb, caddr_t);
if (err != NFSERR_RETVOID) {
tl = nfsm_build(u_int32_t *, NFSX_UNSIGNED);
if (err)
*tl = txdr_unsigned(nfsrv_errmap(nd, err));
else
*tl = 0;
}
*mbp = mb;
*bposp = bpos;
if (err != 0 && err != NFSERR_RETVOID)
nfsrvstats.srvrpc_errs++;
return (mreq);
}
/*
* 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) /* XXX COMMON */
{
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_WAIT, MT_DATA);
if (m->m_len >= MINCLSIZE) {
MCLGET(n, M_WAIT);
}
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 void
nfssvc_program(struct svc_req *rqst, SVCXPRT *xprt)
{
rpcproc_t procnum;
int32_t (*proc)(struct nfsrv_descript *nd, struct nfssvc_sock *slp,
struct mbuf **mreqp);
int flag;
struct nfsrv_descript nd;
struct mbuf *mreq, *mrep;
int error;
if (rqst->rq_vers == NFS_VER2) {
if (rqst->rq_proc > NFSV2PROC_STATFS) {
svcerr_noproc(rqst);
svc_freereq(rqst);
return;
}
procnum = nfsrv_nfsv3_procid[rqst->rq_proc];
flag = 0;
} else {
if (rqst->rq_proc >= NFS_NPROCS) {
svcerr_noproc(rqst);
svc_freereq(rqst);
return;
}
procnum = rqst->rq_proc;
flag = ND_NFSV3;
}
proc = nfsrv3_procs[procnum];
mreq = mrep = NULL;
mreq = rqst->rq_args;
rqst->rq_args = NULL;
nfs_realign(&mreq);
/*
* Note: we want rq_addr, not svc_getrpccaller for nd_nam2 -
* NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP
* mounts.
*/
memset(&nd, 0, sizeof(nd));
nd.nd_md = nd.nd_mrep = mreq;
nd.nd_dpos = mtod(mreq, caddr_t);
nd.nd_nam = svc_getrpccaller(rqst);
nd.nd_nam2 = rqst->rq_addr;
nd.nd_procnum = procnum;
nd.nd_cr = NULL;
nd.nd_flag = flag;
if (nfs_privport) {
/* Check if source port is privileged */
u_short port;
struct sockaddr *nam = nd.nd_nam;
struct sockaddr_in *sin;
sin = (struct sockaddr_in *)nam;
/*
* INET/INET6 - same code:
* sin_port and sin6_port are at same offset
*/
port = ntohs(sin->sin_port);
if (port >= IPPORT_RESERVED &&
nd.nd_procnum != NFSPROC_NULL) {
#ifdef INET6
char b6[INET6_ADDRSTRLEN];
#if defined(KLD_MODULE)
/* Do not use ip6_sprintf: the nfs module should work without INET6. */
#define ip6_sprintf(buf, a) \
(sprintf((buf), "%x:%x:%x:%x:%x:%x:%x:%x", \
(a)->s6_addr16[0], (a)->s6_addr16[1], \
(a)->s6_addr16[2], (a)->s6_addr16[3], \
(a)->s6_addr16[4], (a)->s6_addr16[5], \
(a)->s6_addr16[6], (a)->s6_addr16[7]), \
(buf))
#endif
#endif
printf("NFS request from unprivileged port (%s:%d)\n",
#ifdef INET6
sin->sin_family == AF_INET6 ?
ip6_sprintf(b6, &satosin6(sin)->sin6_addr) :
#if defined(KLD_MODULE)
#undef ip6_sprintf
#endif
#endif
inet_ntoa(sin->sin_addr), port);
svcerr_weakauth(rqst);
svc_freereq(rqst);
return;
}
}
if (proc != nfsrv_null) {
if (!svc_getcred(rqst, &nd.nd_cr, &nd.nd_credflavor)) {
svcerr_weakauth(rqst);
svc_freereq(rqst);
return;
}
#ifdef MAC
mac_cred_associate_nfsd(nd.nd_cr);
#endif
}
nfsrvstats.srvrpccnt[nd.nd_procnum]++;
error = proc(&nd, NULL, &mrep);
if (nd.nd_cr)
crfree(nd.nd_cr);
if (mrep == NULL) {
svcerr_decode(rqst);
svc_freereq(rqst);
return;
}
if (error && error != NFSERR_RETVOID) {
svcerr_systemerr(rqst);
svc_freereq(rqst);
return;
}
if (nd.nd_repstat & NFSERR_AUTHERR) {
svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR);
m_freem(mrep);
} else {
if (!svc_sendreply_mbuf(rqst, mrep))
svcerr_systemerr(rqst);
}
svc_freereq(rqst);
}
/*
* Adds a socket to the list for servicing by nfsds.
*/
static int
nfssvc_addsock(struct file *fp, struct thread *td)
{
int siz;
struct socket *so;
int error;
SVCXPRT *xprt;
so = fp->f_data;
siz = sb_max_adj;
error = soreserve(so, siz, siz);
if (error) {
return (error);
}
/*
* Steal the socket from userland so that it doesn't close
* unexpectedly.
*/
if (so->so_type == SOCK_DGRAM)
xprt = svc_dg_create(nfsrv_pool, so, 0, 0);
else
xprt = svc_vc_create(nfsrv_pool, so, 0, 0);
if (xprt) {
fp->f_ops = &badfileops;
fp->f_data = NULL;
svc_reg(xprt, NFS_PROG, NFS_VER2, nfssvc_program, NULL);
svc_reg(xprt, NFS_PROG, NFS_VER3, nfssvc_program, NULL);
}
return (0);
}
/*
* Called by nfssvc() for nfsds. Just loops around servicing rpc requests
* until it is killed by a signal.
*/
static int
nfssvc_nfsd(struct thread *td, struct nfsd_nfsd_args *args)
{
#ifdef KGSSAPI
char principal[128];
int error;
#endif
#ifdef KGSSAPI
if (args) {
error = copyinstr(args->principal, principal,
sizeof(principal), NULL);
if (error)
return (error);
} else {
snprintf(principal, sizeof(principal), "nfs@%s", hostname);
}
#endif
/*
* Only the first nfsd actually does any work. The RPC code
* adds threads to it as needed. Any extra processes offered
* by nfsd just exit. If nfsd is new enough, it will call us
* once with a structure that specifies how many threads to
* use.
*/
NFSD_LOCK();
if (nfsrv_numnfsd == 0) {
nfsrv_numnfsd++;
NFSD_UNLOCK();
#ifdef KGSSAPI
rpc_gss_set_svc_name(principal, "kerberosv5",
GSS_C_INDEFINITE, NFS_PROG, NFS_VER2);
rpc_gss_set_svc_name(principal, "kerberosv5",
GSS_C_INDEFINITE, NFS_PROG, NFS_VER3);
#endif
if (args) {
nfsrv_pool->sp_minthreads = args->minthreads;
nfsrv_pool->sp_maxthreads = args->maxthreads;
} else {
nfsrv_pool->sp_minthreads = 4;
nfsrv_pool->sp_maxthreads = 4;
}
svc_run(nfsrv_pool);
#ifdef KGSSAPI
rpc_gss_clear_svc_name(NFS_PROG, NFS_VER2);
rpc_gss_clear_svc_name(NFS_PROG, NFS_VER3);
#endif
NFSD_LOCK();
nfsrv_numnfsd--;
nfsrv_init(TRUE);
}
NFSD_UNLOCK();
return (0);
}
/*
* Size the NFS server's duplicate request cache at 1/2 the
* nmbclusters, floating within a (64, 2048) range. This is to
* prevent all mbuf clusters being tied up in the NFS dupreq
* cache for small values of nmbclusters.
*/
static size_t
nfsrv_replay_size(void)
{
size_t replaysiz;
replaysiz = nmbclusters / 2;
if (replaysiz > NFSRVCACHE_MAX_SIZE)
replaysiz = NFSRVCACHE_MAX_SIZE;
if (replaysiz < NFSRVCACHE_MIN_SIZE)
replaysiz = NFSRVCACHE_MIN_SIZE;
replaysiz *= MCLBYTES;
return (replaysiz);
}
/*
* Called when nmbclusters changes - we resize the replay cache
* accordingly.
*/
static void
nfsrv_nmbclusters_change(void *tag)
{
if (nfsrv_pool)
replay_setsize(nfsrv_pool->sp_rcache, nfsrv_replay_size());
}
/*
* Initialize the data structures for the server.
* Handshake with any new nfsds starting up to avoid any chance of
* corruption.
*/
void
nfsrv_init(int terminating)
{
NFSD_LOCK_ASSERT();
if (terminating) {
NFSD_UNLOCK();
EVENTHANDLER_DEREGISTER(nmbclusters_change,
nfsrv_nmbclusters_tag);
svcpool_destroy(nfsrv_pool);
nfsrv_pool = NULL;
NFSD_LOCK();
} else
nfs_pub.np_valid = 0;
NFSD_UNLOCK();
nfsrv_pool = svcpool_create("nfsd", SYSCTL_STATIC_CHILDREN(_vfs_nfsrv));
nfsrv_pool->sp_rcache = replay_newcache(nfsrv_replay_size());
nfsrv_pool->sp_assign = fha_assign;
nfsrv_pool->sp_done = fha_nd_complete;
nfsrv_nmbclusters_tag = EVENTHANDLER_REGISTER(nmbclusters_change,
nfsrv_nmbclusters_change, NULL, EVENTHANDLER_PRI_FIRST);
NFSD_LOCK();
}
#endif /* !NFS_LEGACYRPC */