xref: /freebsd/sys/fs/nfsclient/nfs_clkrpc.c (revision 1c05a6ea6b849ff95e539c31adea887c644a6a01)
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  * 3. 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 
46 NFSDLOCKMUTEX;
47 
48 extern SVCPOOL	*nfscbd_pool;
49 
50 static int nfs_cbproc(struct nfsrv_descript *, u_int32_t);
51 
52 extern u_long sb_max_adj;
53 extern int nfs_numnfscbd;
54 extern int nfscl_debuglevel;
55 
56 /*
57  * NFS client system calls for handling callbacks.
58  */
59 
60 /*
61  * Handles server to client callbacks.
62  */
63 static void
64 nfscb_program(struct svc_req *rqst, SVCXPRT *xprt)
65 {
66 	struct nfsrv_descript nd;
67 	int cacherep, credflavor;
68 
69 	memset(&nd, 0, sizeof(nd));
70 	if (rqst->rq_proc != NFSPROC_NULL &&
71 	    rqst->rq_proc != NFSV4PROC_CBCOMPOUND) {
72 		svcerr_noproc(rqst);
73 		svc_freereq(rqst);
74 		return;
75 	}
76 	nd.nd_procnum = rqst->rq_proc;
77 	nd.nd_flag = (ND_NFSCB | ND_NFSV4);
78 
79 	/*
80 	 * Note: we want rq_addr, not svc_getrpccaller for nd_nam2 -
81 	 * NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP
82 	 * mounts.
83 	 */
84 	nd.nd_mrep = rqst->rq_args;
85 	rqst->rq_args = NULL;
86 	newnfs_realign(&nd.nd_mrep, M_WAITOK);
87 	nd.nd_md = nd.nd_mrep;
88 	nd.nd_dpos = mtod(nd.nd_md, caddr_t);
89 	nd.nd_nam = svc_getrpccaller(rqst);
90 	nd.nd_nam2 = rqst->rq_addr;
91 	nd.nd_mreq = NULL;
92 	nd.nd_cred = NULL;
93 
94 	NFSCL_DEBUG(1, "cbproc=%d\n",nd.nd_procnum);
95 	if (nd.nd_procnum != NFSPROC_NULL) {
96 		if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) {
97 			svcerr_weakauth(rqst);
98 			svc_freereq(rqst);
99 			m_freem(nd.nd_mrep);
100 			return;
101 		}
102 
103 		/* For now, I don't care what credential flavor was used. */
104 #ifdef notyet
105 #ifdef MAC
106 		mac_cred_associate_nfsd(nd.nd_cred);
107 #endif
108 #endif
109 		cacherep = nfs_cbproc(&nd, rqst->rq_xid);
110 	} else {
111 		NFSMGET(nd.nd_mreq);
112 		nd.nd_mreq->m_len = 0;
113 		cacherep = RC_REPLY;
114 	}
115 	if (nd.nd_mrep != NULL)
116 		m_freem(nd.nd_mrep);
117 
118 	if (nd.nd_cred != NULL)
119 		crfree(nd.nd_cred);
120 
121 	if (cacherep == RC_DROPIT) {
122 		if (nd.nd_mreq != NULL)
123 			m_freem(nd.nd_mreq);
124 		svc_freereq(rqst);
125 		return;
126 	}
127 
128 	if (nd.nd_mreq == NULL) {
129 		svcerr_decode(rqst);
130 		svc_freereq(rqst);
131 		return;
132 	}
133 
134 	if (nd.nd_repstat & NFSERR_AUTHERR) {
135 		svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR);
136 		if (nd.nd_mreq != NULL)
137 			m_freem(nd.nd_mreq);
138 	} else if (!svc_sendreply_mbuf(rqst, nd.nd_mreq))
139 		svcerr_systemerr(rqst);
140 	else
141 		NFSCL_DEBUG(1, "cbrep sent\n");
142 	svc_freereq(rqst);
143 }
144 
145 /*
146  * Check the cache and, optionally, do the RPC.
147  * Return the appropriate cache response.
148  */
149 static int
150 nfs_cbproc(struct nfsrv_descript *nd, u_int32_t xid)
151 {
152 	struct thread *td = curthread;
153 	int cacherep;
154 
155 	if (nd->nd_nam2 == NULL)
156 		nd->nd_flag |= ND_STREAMSOCK;
157 
158 	nfscl_docb(nd, td);
159 	if (nd->nd_repstat == NFSERR_DONTREPLY)
160 		cacherep = RC_DROPIT;
161 	else
162 		cacherep = RC_REPLY;
163 	return (cacherep);
164 }
165 
166 /*
167  * Adds a socket to the list for servicing by nfscbds.
168  */
169 int
170 nfscbd_addsock(struct file *fp)
171 {
172 	int siz;
173 	struct socket *so;
174 	int error;
175 	SVCXPRT *xprt;
176 
177 	so = fp->f_data;
178 
179 	siz = sb_max_adj;
180 	error = soreserve(so, siz, siz);
181 	if (error)
182 		return (error);
183 
184 	/*
185 	 * Steal the socket from userland so that it doesn't close
186 	 * unexpectedly.
187 	 */
188 	if (so->so_type == SOCK_DGRAM)
189 		xprt = svc_dg_create(nfscbd_pool, so, 0, 0);
190 	else
191 		xprt = svc_vc_create(nfscbd_pool, so, 0, 0);
192 	if (xprt) {
193 		fp->f_ops = &badfileops;
194 		fp->f_data = NULL;
195 		svc_reg(xprt, NFS_CALLBCKPROG, NFSV4_CBVERS, nfscb_program,
196 		    NULL);
197 		SVC_RELEASE(xprt);
198 	}
199 
200 	return (0);
201 }
202 
203 /*
204  * Called by nfssvc() for nfscbds. Just loops around servicing rpc requests
205  * until it is killed by a signal.
206  *
207  * For now, only support callbacks via RPCSEC_GSS if there is a KerberosV
208  * keytab entry with a host based entry in it on the client. (I'm not even
209  * sure that getting Acceptor credentials for a user principal with a
210  * credentials cache is possible, but even if it is, major changes to the
211  * kgssapi would be required.)
212  * I don't believe that this is a serious limitation since, as of 2009, most
213  * NFSv4 servers supporting callbacks are using AUTH_SYS for callbacks even
214  * when the client is using RPCSEC_GSS. (This BSD server uses AUTH_SYS
215  * for callbacks unless nfsrv_gsscallbackson is set non-zero.)
216  */
217 int
218 nfscbd_nfsd(struct thread *td, struct nfsd_nfscbd_args *args)
219 {
220 	char principal[128];
221 	int error;
222 
223 	if (args != NULL) {
224 		error = copyinstr(args->principal, principal,
225 		    sizeof(principal), NULL);
226 		if (error)
227 			return (error);
228 	} else {
229 		principal[0] = '\0';
230 	}
231 
232 	/*
233 	 * Only the first nfsd actually does any work. The RPC code
234 	 * adds threads to it as needed. Any extra processes offered
235 	 * by nfsd just exit. If nfsd is new enough, it will call us
236 	 * once with a structure that specifies how many threads to
237 	 * use.
238 	 */
239 	NFSD_LOCK();
240 	if (nfs_numnfscbd == 0) {
241 		nfs_numnfscbd++;
242 
243 		NFSD_UNLOCK();
244 
245 		if (principal[0] != '\0')
246 			rpc_gss_set_svc_name_call(principal, "kerberosv5",
247 			    GSS_C_INDEFINITE, NFS_CALLBCKPROG, NFSV4_CBVERS);
248 
249 		nfscbd_pool->sp_minthreads = 4;
250 		nfscbd_pool->sp_maxthreads = 4;
251 
252 		svc_run(nfscbd_pool);
253 
254 		rpc_gss_clear_svc_name_call(NFS_CALLBCKPROG, NFSV4_CBVERS);
255 
256 		NFSD_LOCK();
257 		nfs_numnfscbd--;
258 		nfsrvd_cbinit(1);
259 	}
260 	NFSD_UNLOCK();
261 
262 	return (0);
263 }
264 
265 /*
266  * Initialize the data structures for the server.
267  * Handshake with any new nfsds starting up to avoid any chance of
268  * corruption.
269  */
270 void
271 nfsrvd_cbinit(int terminating)
272 {
273 
274 	NFSD_LOCK_ASSERT();
275 
276 	if (terminating) {
277 		/* Wait for any xprt registrations to complete. */
278 		while (nfs_numnfscbd > 0)
279 			msleep(&nfs_numnfscbd, NFSDLOCKMUTEXPTR, PZERO,
280 			    "nfscbdt", 0);
281 		if (nfscbd_pool != NULL) {
282 			NFSD_UNLOCK();
283 			svcpool_close(nfscbd_pool);
284 			NFSD_LOCK();
285 		}
286 	}
287 
288 	if (nfscbd_pool == NULL) {
289 		NFSD_UNLOCK();
290 		nfscbd_pool = svcpool_create("nfscbd", NULL);
291 		nfscbd_pool->sp_rcache = NULL;
292 		nfscbd_pool->sp_assign = NULL;
293 		nfscbd_pool->sp_done = NULL;
294 		NFSD_LOCK();
295 	}
296 }
297 
298