1/*-
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Rick Macklem at The University of Guelph.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD$");
36
37#include "opt_kgssapi.h"
38
39#include <fs/nfs/nfsport.h>
40
41#include <rpc/rpc.h>
42#include <rpc/rpcsec_gss.h>
43#include <rpc/replay.h>
44
45
46NFSDLOCKMUTEX;
47
48SVCPOOL		*nfscbd_pool;
49
50static int nfs_cbproc(struct nfsrv_descript *, u_int32_t);
51
52extern u_long sb_max_adj;
53extern int nfs_numnfscbd;
54
55/*
56 * NFS client system calls for handling callbacks.
57 */
58
59/*
60 * Handles server to client callbacks.
61 */
62static void
63nfscb_program(struct svc_req *rqst, SVCXPRT *xprt)
64{
65	struct nfsrv_descript nd;
66	int cacherep, credflavor;
67
68	memset(&nd, 0, sizeof(nd));
69	if (rqst->rq_proc != NFSPROC_NULL &&
70	    rqst->rq_proc != NFSV4PROC_CBCOMPOUND) {
71		svcerr_noproc(rqst);
72		svc_freereq(rqst);
73		return;
74	}
75	nd.nd_procnum = rqst->rq_proc;
76	nd.nd_flag = (ND_NFSCB | ND_NFSV4);
77
78	/*
79	 * Note: we want rq_addr, not svc_getrpccaller for nd_nam2 -
80	 * NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP
81	 * mounts.
82	 */
83	nd.nd_mrep = rqst->rq_args;
84	rqst->rq_args = NULL;
85	newnfs_realign(&nd.nd_mrep, M_WAITOK);
86	nd.nd_md = nd.nd_mrep;
87	nd.nd_dpos = mtod(nd.nd_md, caddr_t);
88	nd.nd_nam = svc_getrpccaller(rqst);
89	nd.nd_nam2 = rqst->rq_addr;
90	nd.nd_mreq = NULL;
91	nd.nd_cred = NULL;
92
93	if (nd.nd_procnum != NFSPROC_NULL) {
94		if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) {
95			svcerr_weakauth(rqst);
96			svc_freereq(rqst);
97			m_freem(nd.nd_mrep);
98			return;
99		}
100
101		/* For now, I don't care what credential flavor was used. */
102#ifdef notyet
103#ifdef MAC
104		mac_cred_associate_nfsd(nd.nd_cred);
105#endif
106#endif
107		cacherep = nfs_cbproc(&nd, rqst->rq_xid);
108	} else {
109		NFSMGET(nd.nd_mreq);
110		nd.nd_mreq->m_len = 0;
111		cacherep = RC_REPLY;
112	}
113	if (nd.nd_mrep != NULL)
114		m_freem(nd.nd_mrep);
115
116	if (nd.nd_cred != NULL)
117		crfree(nd.nd_cred);
118
119	if (cacherep == RC_DROPIT) {
120		if (nd.nd_mreq != NULL)
121			m_freem(nd.nd_mreq);
122		svc_freereq(rqst);
123		return;
124	}
125
126	if (nd.nd_mreq == NULL) {
127		svcerr_decode(rqst);
128		svc_freereq(rqst);
129		return;
130	}
131
132	if (nd.nd_repstat & NFSERR_AUTHERR) {
133		svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR);
134		if (nd.nd_mreq != NULL)
135			m_freem(nd.nd_mreq);
136	} else if (!svc_sendreply_mbuf(rqst, nd.nd_mreq)) {
137		svcerr_systemerr(rqst);
138	}
139	svc_freereq(rqst);
140}
141
142/*
143 * Check the cache and, optionally, do the RPC.
144 * Return the appropriate cache response.
145 */
146static int
147nfs_cbproc(struct nfsrv_descript *nd, u_int32_t xid)
148{
149	struct thread *td = curthread;
150	int cacherep;
151
152	if (nd->nd_nam2 == NULL)
153		nd->nd_flag |= ND_STREAMSOCK;
154
155	nfscl_docb(nd, td);
156	if (nd->nd_repstat == NFSERR_DONTREPLY)
157		cacherep = RC_DROPIT;
158	else
159		cacherep = RC_REPLY;
160	return (cacherep);
161}
162
163/*
164 * Adds a socket to the list for servicing by nfscbds.
165 */
166int
167nfscbd_addsock(struct file *fp)
168{
169	int siz;
170	struct socket *so;
171	int error;
172	SVCXPRT *xprt;
173
174	so = fp->f_data;
175
176	siz = sb_max_adj;
177	error = soreserve(so, siz, siz);
178	if (error)
179		return (error);
180
181	/*
182	 * Steal the socket from userland so that it doesn't close
183	 * unexpectedly.
184	 */
185	if (so->so_type == SOCK_DGRAM)
186		xprt = svc_dg_create(nfscbd_pool, so, 0, 0);
187	else
188		xprt = svc_vc_create(nfscbd_pool, so, 0, 0);
189	if (xprt) {
190		fp->f_ops = &badfileops;
191		fp->f_data = NULL;
192		svc_reg(xprt, NFS_CALLBCKPROG, NFSV4_CBVERS, nfscb_program,
193		    NULL);
194		SVC_RELEASE(xprt);
195	}
196
197	return (0);
198}
199
200/*
201 * Called by nfssvc() for nfscbds. Just loops around servicing rpc requests
202 * until it is killed by a signal.
203 *
204 * For now, only support callbacks via RPCSEC_GSS if there is a KerberosV
205 * keytab entry with a host based entry in it on the client. (I'm not even
206 * sure that getting Acceptor credentials for a user principal with a
207 * credentials cache is possible, but even if it is, major changes to the
208 * kgssapi would be required.)
209 * I don't believe that this is a serious limitation since, as of 2009, most
210 * NFSv4 servers supporting callbacks are using AUTH_SYS for callbacks even
211 * when the client is using RPCSEC_GSS. (This BSD server uses AUTH_SYS
212 * for callbacks unless nfsrv_gsscallbackson is set non-zero.)
213 */
214int
215nfscbd_nfsd(struct thread *td, struct nfsd_nfscbd_args *args)
216{
217	char principal[128];
218	int error;
219
220	if (args != NULL) {
221		error = copyinstr(args->principal, principal,
222		    sizeof(principal), NULL);
223		if (error)
224			return (error);
225	} else {
226		principal[0] = '\0';
227	}
228
229	/*
230	 * Only the first nfsd actually does any work. The RPC code
231	 * adds threads to it as needed. Any extra processes offered
232	 * by nfsd just exit. If nfsd is new enough, it will call us
233	 * once with a structure that specifies how many threads to
234	 * use.
235	 */
236	NFSD_LOCK();
237	if (nfs_numnfscbd == 0) {
238		nfs_numnfscbd++;
239
240		NFSD_UNLOCK();
241
242		if (principal[0] != '\0')
243			rpc_gss_set_svc_name_call(principal, "kerberosv5",
244			    GSS_C_INDEFINITE, NFS_CALLBCKPROG, NFSV4_CBVERS);
245
246		nfscbd_pool->sp_minthreads = 4;
247		nfscbd_pool->sp_maxthreads = 4;
248
249		svc_run(nfscbd_pool);
250
251		rpc_gss_clear_svc_name_call(NFS_CALLBCKPROG, NFSV4_CBVERS);
252
253		NFSD_LOCK();
254		nfs_numnfscbd--;
255		nfsrvd_cbinit(1);
256	}
257	NFSD_UNLOCK();
258
259	return (0);
260}
261
262/*
263 * Initialize the data structures for the server.
264 * Handshake with any new nfsds starting up to avoid any chance of
265 * corruption.
266 */
267void
268nfsrvd_cbinit(int terminating)
269{
270
271	NFSD_LOCK_ASSERT();
272
273	if (nfscbd_pool == NULL) {
274		NFSD_UNLOCK();
275		nfscbd_pool = svcpool_create("nfscbd", NULL);
276		nfscbd_pool->sp_rcache = NULL;
277		nfscbd_pool->sp_assign = NULL;
278		nfscbd_pool->sp_done = NULL;
279		NFSD_LOCK();
280	}
281}
282
283