freebsd-dev/sys/nfsserver/nfs_srvkrpc.c
Pawel Jakub Dawidek 2609222ab4 Merge Capsicum overhaul:
- Capability is no longer separate descriptor type. Now every descriptor
  has set of its own capability rights.

- The cap_new(2) system call is left, but it is no longer documented and
  should not be used in new code.

- The new syscall cap_rights_limit(2) should be used instead of
  cap_new(2), which limits capability rights of the given descriptor
  without creating a new one.

- The cap_getrights(2) syscall is renamed to cap_rights_get(2).

- If CAP_IOCTL capability right is present we can further reduce allowed
  ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
  ioctls can be retrived with cap_ioctls_get(2) syscall.

- If CAP_FCNTL capability right is present we can further reduce fcntls
  that can be used with the new cap_fcntls_limit(2) syscall and retrive
  them with cap_fcntls_get(2).

- To support ioctl and fcntl white-listing the filedesc structure was
  heavly modified.

- The audit subsystem, kdump and procstat tools were updated to
  recognize new syscalls.

- Capability rights were revised and eventhough I tried hard to provide
  backward API and ABI compatibility there are some incompatible changes
  that are described in detail below:

	CAP_CREATE old behaviour:
	- Allow for openat(2)+O_CREAT.
	- Allow for linkat(2).
	- Allow for symlinkat(2).
	CAP_CREATE new behaviour:
	- Allow for openat(2)+O_CREAT.

	Added CAP_LINKAT:
	- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
	- Allow to be target for renameat(2).

	Added CAP_SYMLINKAT:
	- Allow for symlinkat(2).

	Removed CAP_DELETE. Old behaviour:
	- Allow for unlinkat(2) when removing non-directory object.
	- Allow to be source for renameat(2).

	Removed CAP_RMDIR. Old behaviour:
	- Allow for unlinkat(2) when removing directory.

	Added CAP_RENAMEAT:
	- Required for source directory for the renameat(2) syscall.

	Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
	- Allow for unlinkat(2) on any object.
	- Required if target of renameat(2) exists and will be removed by this
	  call.

	Removed CAP_MAPEXEC.

	CAP_MMAP old behaviour:
	- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
	  PROT_WRITE.
	CAP_MMAP new behaviour:
	- Allow for mmap(2)+PROT_NONE.

	Added CAP_MMAP_R:
	- Allow for mmap(PROT_READ).
	Added CAP_MMAP_W:
	- Allow for mmap(PROT_WRITE).
	Added CAP_MMAP_X:
	- Allow for mmap(PROT_EXEC).
	Added CAP_MMAP_RW:
	- Allow for mmap(PROT_READ | PROT_WRITE).
	Added CAP_MMAP_RX:
	- Allow for mmap(PROT_READ | PROT_EXEC).
	Added CAP_MMAP_WX:
	- Allow for mmap(PROT_WRITE | PROT_EXEC).
	Added CAP_MMAP_RWX:
	- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).

	Renamed CAP_MKDIR to CAP_MKDIRAT.
	Renamed CAP_MKFIFO to CAP_MKFIFOAT.
	Renamed CAP_MKNODE to CAP_MKNODEAT.

	CAP_READ old behaviour:
	- Allow pread(2).
	- Disallow read(2), readv(2) (if there is no CAP_SEEK).
	CAP_READ new behaviour:
	- Allow read(2), readv(2).
	- Disallow pread(2) (CAP_SEEK was also required).

	CAP_WRITE old behaviour:
	- Allow pwrite(2).
	- Disallow write(2), writev(2) (if there is no CAP_SEEK).
	CAP_WRITE new behaviour:
	- Allow write(2), writev(2).
	- Disallow pwrite(2) (CAP_SEEK was also required).

	Added convinient defines:

	#define	CAP_PREAD		(CAP_SEEK | CAP_READ)
	#define	CAP_PWRITE		(CAP_SEEK | CAP_WRITE)
	#define	CAP_MMAP_R		(CAP_MMAP | CAP_SEEK | CAP_READ)
	#define	CAP_MMAP_W		(CAP_MMAP | CAP_SEEK | CAP_WRITE)
	#define	CAP_MMAP_X		(CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
	#define	CAP_MMAP_RW		(CAP_MMAP_R | CAP_MMAP_W)
	#define	CAP_MMAP_RX		(CAP_MMAP_R | CAP_MMAP_X)
	#define	CAP_MMAP_WX		(CAP_MMAP_W | CAP_MMAP_X)
	#define	CAP_MMAP_RWX		(CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
	#define	CAP_RECV		CAP_READ
	#define	CAP_SEND		CAP_WRITE

	#define	CAP_SOCK_CLIENT \
		(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
		 CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
	#define	CAP_SOCK_SERVER \
		(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
		 CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
		 CAP_SETSOCKOPT | CAP_SHUTDOWN)

	Added defines for backward API compatibility:

	#define	CAP_MAPEXEC		CAP_MMAP_X
	#define	CAP_DELETE		CAP_UNLINKAT
	#define	CAP_MKDIR		CAP_MKDIRAT
	#define	CAP_RMDIR		CAP_UNLINKAT
	#define	CAP_MKFIFO		CAP_MKFIFOAT
	#define	CAP_MKNOD		CAP_MKNODAT
	#define	CAP_SOCK_ALL		(CAP_SOCK_CLIENT | CAP_SOCK_SERVER)

Sponsored by:	The FreeBSD Foundation
Reviewed by:	Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with:	rwatson, benl, jonathan
ABI compatibility discussed with:	kib
2013-03-02 00:53:12 +00:00

542 lines
13 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/capability.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/jail.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/nfsproto.h>
#include <nfsserver/nfs.h>
#include <nfsserver/nfsm_subs.h>
#include <nfsserver/nfsrvcache.h>
#include <nfsserver/nfs_fha.h>
#include <security/mac/mac_framework.h>
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;
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");
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
*/
/*
* This is now called from nfssvc() in nfs/nfs_nfssvc.c.
*/
/*
* 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
*/
int
nfssvc_nfsserver(struct thread *td, struct nfssvc_args *uap)
{
struct file *fp;
struct nfsd_addsock_args addsockarg;
struct nfsd_nfsd_args nfsdarg;
int error;
if (uap->flag & NFSSVC_ADDSOCK) {
error = copyin(uap->argp, (caddr_t)&addsockarg,
sizeof(addsockarg));
if (error)
return (error);
error = fget(td, addsockarg.sock, CAP_SOCK_SERVER, &fp);
if (error)
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;
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_WAITOK, MT_DATA);
/*
* If this is a big reply, use a cluster
*/
mreq->m_len = 0;
if (siz >= MINCLSIZE) {
MCLGET(mreq, M_WAITOK);
}
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);
}
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;
(void)nfs_realign(&mreq, M_WAITOK);
/*
* 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);
m_freem(mreq);
svcerr_weakauth(rqst);
svc_freereq(rqst);
return;
}
}
if (proc != nfsrv_null) {
if (!svc_getcred(rqst, &nd.nd_cr, &nd.nd_credflavor)) {
m_freem(mreq);
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);
SVC_RELEASE(xprt);
}
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)
{
char principal[128];
int error;
if (args) {
error = copyinstr(args->principal, principal,
sizeof(principal), NULL);
if (error)
return (error);
} else {
memcpy(principal, "nfs@", 4);
getcredhostname(td->td_ucred, principal + 4,
sizeof(principal) - 4);
}
/*
* 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();
rpc_gss_set_svc_name_call(principal, "kerberosv5",
GSS_C_INDEFINITE, NFS_PROG, NFS_VER2);
rpc_gss_set_svc_name_call(principal, "kerberosv5",
GSS_C_INDEFINITE, NFS_PROG, NFS_VER3);
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);
rpc_gss_clear_svc_name_call(NFS_PROG, NFS_VER2);
rpc_gss_clear_svc_name_call(NFS_PROG, NFS_VER3);
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();
}