1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Rick Macklem at The University of Guelph.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 */
35
36 #include <sys/cdefs.h>
37 #include "opt_kgssapi.h"
38 #include "opt_kern_tls.h"
39
40 #include <fs/nfs/nfsport.h>
41
42 #include <rpc/rpc.h>
43 #include <rpc/replay.h>
44 #include <rpc/rpcsec_gss.h>
45 #include <rpc/rpcsec_tls.h>
46
47 NFSDLOCKMUTEX;
48
49 extern SVCPOOL *nfscbd_pool;
50
51 static int nfs_cbproc(struct nfsrv_descript *, u_int32_t);
52
53 extern u_long sb_max_adj;
54 extern int nfs_numnfscbd;
55 extern int nfscl_debuglevel;
56
57 /*
58 * NFS client system calls for handling callbacks.
59 */
60
61 /*
62 * Handles server to client callbacks.
63 */
64 static void
nfscb_program(struct svc_req * rqst,SVCXPRT * xprt)65 nfscb_program(struct svc_req *rqst, SVCXPRT *xprt)
66 {
67 struct nfsrv_descript nd;
68 int cacherep, credflavor;
69 #ifdef KERN_TLS
70 u_int maxlen;
71 #endif
72
73 memset(&nd, 0, sizeof(nd));
74 if (rqst->rq_proc != NFSPROC_NULL &&
75 rqst->rq_proc != NFSV4PROC_CBCOMPOUND) {
76 svcerr_noproc(rqst);
77 svc_freereq(rqst);
78 return;
79 }
80 nd.nd_procnum = rqst->rq_proc;
81 nd.nd_flag = (ND_NFSCB | ND_NFSV4);
82
83 /*
84 * Note: we want rq_addr, not svc_getrpccaller for nd_nam2 -
85 * NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP
86 * mounts.
87 */
88 nd.nd_mrep = rqst->rq_args;
89 rqst->rq_args = NULL;
90 newnfs_realign(&nd.nd_mrep, M_WAITOK);
91 nd.nd_md = nd.nd_mrep;
92 nd.nd_dpos = mtod(nd.nd_md, caddr_t);
93 nd.nd_nam = svc_getrpccaller(rqst);
94 nd.nd_nam2 = rqst->rq_addr;
95 nd.nd_mreq = NULL;
96 nd.nd_cred = NULL;
97
98 NFSCL_DEBUG(1, "cbproc=%d\n",nd.nd_procnum);
99 if (nd.nd_procnum != NFSPROC_NULL) {
100 if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) {
101 svcerr_weakauth(rqst);
102 svc_freereq(rqst);
103 m_freem(nd.nd_mrep);
104 return;
105 }
106
107 /* For now, I don't care what credential flavor was used. */
108 #ifdef notyet
109 #ifdef MAC
110 mac_cred_associate_nfsd(nd.nd_cred);
111 #endif
112 #endif
113 #ifdef KERN_TLS
114 if ((xprt->xp_tls & RPCTLS_FLAGS_HANDSHAKE) != 0 &&
115 rpctls_getinfo(&maxlen, false, false)) {
116 nd.nd_flag |= ND_EXTPG;
117 nd.nd_maxextsiz = maxlen;
118 }
119 #endif
120 cacherep = nfs_cbproc(&nd, rqst->rq_xid);
121 } else {
122 NFSMGET(nd.nd_mreq);
123 nd.nd_mreq->m_len = 0;
124 cacherep = RC_REPLY;
125 }
126 if (nd.nd_mrep != NULL)
127 m_freem(nd.nd_mrep);
128
129 if (nd.nd_cred != NULL)
130 crfree(nd.nd_cred);
131
132 if (cacherep == RC_DROPIT) {
133 if (nd.nd_mreq != NULL)
134 m_freem(nd.nd_mreq);
135 svc_freereq(rqst);
136 return;
137 }
138
139 if (nd.nd_mreq == NULL) {
140 svcerr_decode(rqst);
141 svc_freereq(rqst);
142 return;
143 }
144
145 if (nd.nd_repstat & NFSERR_AUTHERR) {
146 svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR);
147 if (nd.nd_mreq != NULL)
148 m_freem(nd.nd_mreq);
149 } else if (!svc_sendreply_mbuf(rqst, nd.nd_mreq))
150 svcerr_systemerr(rqst);
151 else
152 NFSCL_DEBUG(1, "cbrep sent\n");
153 svc_freereq(rqst);
154 }
155
156 /*
157 * Check the cache and, optionally, do the RPC.
158 * Return the appropriate cache response.
159 */
160 static int
nfs_cbproc(struct nfsrv_descript * nd,u_int32_t xid)161 nfs_cbproc(struct nfsrv_descript *nd, u_int32_t xid)
162 {
163 struct thread *td = curthread;
164 int cacherep;
165
166 if (nd->nd_nam2 == NULL)
167 nd->nd_flag |= ND_STREAMSOCK;
168
169 nfscl_docb(nd, td);
170 if (nd->nd_repstat == NFSERR_DONTREPLY)
171 cacherep = RC_DROPIT;
172 else
173 cacherep = RC_REPLY;
174 return (cacherep);
175 }
176
177 /*
178 * Adds a socket to the list for servicing by nfscbds.
179 */
180 int
nfscbd_addsock(struct file * fp)181 nfscbd_addsock(struct file *fp)
182 {
183 int siz;
184 struct socket *so;
185 int error;
186 SVCXPRT *xprt;
187
188 so = fp->f_data;
189
190 siz = sb_max_adj;
191 error = soreserve(so, siz, siz);
192 if (error)
193 return (error);
194
195 /*
196 * Steal the socket from userland so that it doesn't close
197 * unexpectedly.
198 */
199 if (so->so_type == SOCK_DGRAM)
200 xprt = svc_dg_create(nfscbd_pool, so, 0, 0);
201 else
202 xprt = svc_vc_create(nfscbd_pool, so, 0, 0);
203 if (xprt) {
204 fp->f_ops = &badfileops;
205 fp->f_data = NULL;
206 svc_reg(xprt, NFS_CALLBCKPROG, NFSV4_CBVERS, nfscb_program,
207 NULL);
208 SVC_RELEASE(xprt);
209 }
210
211 return (0);
212 }
213
214 /*
215 * Called by nfssvc() for nfscbds. Just loops around servicing rpc requests
216 * until it is killed by a signal.
217 *
218 * For now, only support callbacks via RPCSEC_GSS if there is a KerberosV
219 * keytab entry with a host based entry in it on the client. (I'm not even
220 * sure that getting Acceptor credentials for a user principal with a
221 * credentials cache is possible, but even if it is, major changes to the
222 * kgssapi would be required.)
223 * I don't believe that this is a serious limitation since, as of 2009, most
224 * NFSv4 servers supporting callbacks are using AUTH_SYS for callbacks even
225 * when the client is using RPCSEC_GSS. (This BSD server uses AUTH_SYS
226 * for callbacks unless nfsrv_gsscallbackson is set non-zero.)
227 */
228 int
nfscbd_nfsd(struct thread * td,struct nfsd_nfscbd_args * args)229 nfscbd_nfsd(struct thread *td, struct nfsd_nfscbd_args *args)
230 {
231 char principal[128];
232 int error;
233
234 if (args != NULL) {
235 error = copyinstr(args->principal, principal,
236 sizeof(principal), NULL);
237 if (error)
238 return (error);
239 } else {
240 principal[0] = '\0';
241 }
242
243 /*
244 * Only the first nfsd actually does any work. The RPC code
245 * adds threads to it as needed. Any extra processes offered
246 * by nfsd just exit. If nfsd is new enough, it will call us
247 * once with a structure that specifies how many threads to
248 * use.
249 */
250 NFSD_LOCK();
251 if (nfs_numnfscbd == 0) {
252 nfs_numnfscbd++;
253
254 NFSD_UNLOCK();
255
256 if (principal[0] != '\0')
257 rpc_gss_set_svc_name_call(principal, "kerberosv5",
258 GSS_C_INDEFINITE, NFS_CALLBCKPROG, NFSV4_CBVERS);
259
260 nfscbd_pool->sp_minthreads = 4;
261 nfscbd_pool->sp_maxthreads = 4;
262
263 svc_run(nfscbd_pool);
264
265 rpc_gss_clear_svc_name_call(NFS_CALLBCKPROG, NFSV4_CBVERS);
266
267 NFSD_LOCK();
268 nfs_numnfscbd--;
269 nfsrvd_cbinit(1);
270 }
271 NFSD_UNLOCK();
272
273 return (0);
274 }
275
276 /*
277 * Initialize the data structures for the server.
278 * Handshake with any new nfsds starting up to avoid any chance of
279 * corruption.
280 */
281 void
nfsrvd_cbinit(int terminating)282 nfsrvd_cbinit(int terminating)
283 {
284
285 NFSD_LOCK_ASSERT();
286
287 if (terminating) {
288 /* Wait for any xprt registrations to complete. */
289 while (nfs_numnfscbd > 0)
290 msleep(&nfs_numnfscbd, NFSDLOCKMUTEXPTR, PZERO,
291 "nfscbdt", 0);
292 if (nfscbd_pool != NULL) {
293 NFSD_UNLOCK();
294 svcpool_close(nfscbd_pool);
295 NFSD_LOCK();
296 }
297 }
298
299 if (nfscbd_pool == NULL) {
300 NFSD_UNLOCK();
301 nfscbd_pool = svcpool_create("nfscbd", NULL);
302 nfscbd_pool->sp_rcache = NULL;
303 nfscbd_pool->sp_assign = NULL;
304 nfscbd_pool->sp_done = NULL;
305 NFSD_LOCK();
306 }
307 }
308