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 __FBSDID("$FreeBSD$"); 38 39 #include "opt_kgssapi.h" 40 #include "opt_kern_tls.h" 41 42 #include <fs/nfs/nfsport.h> 43 44 #include <rpc/rpc.h> 45 #include <rpc/replay.h> 46 #include <rpc/rpcsec_gss.h> 47 #include <rpc/rpcsec_tls.h> 48 49 NFSDLOCKMUTEX; 50 51 extern SVCPOOL *nfscbd_pool; 52 53 static int nfs_cbproc(struct nfsrv_descript *, u_int32_t); 54 55 extern u_long sb_max_adj; 56 extern int nfs_numnfscbd; 57 extern int nfscl_debuglevel; 58 59 /* 60 * NFS client system calls for handling callbacks. 61 */ 62 63 /* 64 * Handles server to client callbacks. 65 */ 66 static void 67 nfscb_program(struct svc_req *rqst, SVCXPRT *xprt) 68 { 69 struct nfsrv_descript nd; 70 int cacherep, credflavor; 71 #ifdef KERN_TLS 72 u_int maxlen; 73 #endif 74 75 memset(&nd, 0, sizeof(nd)); 76 if (rqst->rq_proc != NFSPROC_NULL && 77 rqst->rq_proc != NFSV4PROC_CBCOMPOUND) { 78 svcerr_noproc(rqst); 79 svc_freereq(rqst); 80 return; 81 } 82 nd.nd_procnum = rqst->rq_proc; 83 nd.nd_flag = (ND_NFSCB | ND_NFSV4); 84 85 /* 86 * Note: we want rq_addr, not svc_getrpccaller for nd_nam2 - 87 * NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP 88 * mounts. 89 */ 90 nd.nd_mrep = rqst->rq_args; 91 rqst->rq_args = NULL; 92 newnfs_realign(&nd.nd_mrep, M_WAITOK); 93 nd.nd_md = nd.nd_mrep; 94 nd.nd_dpos = mtod(nd.nd_md, caddr_t); 95 nd.nd_nam = svc_getrpccaller(rqst); 96 nd.nd_nam2 = rqst->rq_addr; 97 nd.nd_mreq = NULL; 98 nd.nd_cred = NULL; 99 100 NFSCL_DEBUG(1, "cbproc=%d\n",nd.nd_procnum); 101 if (nd.nd_procnum != NFSPROC_NULL) { 102 if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) { 103 svcerr_weakauth(rqst); 104 svc_freereq(rqst); 105 m_freem(nd.nd_mrep); 106 return; 107 } 108 109 /* For now, I don't care what credential flavor was used. */ 110 #ifdef notyet 111 #ifdef MAC 112 mac_cred_associate_nfsd(nd.nd_cred); 113 #endif 114 #endif 115 #ifdef KERN_TLS 116 if ((xprt->xp_tls & RPCTLS_FLAGS_HANDSHAKE) != 0 && 117 rpctls_getinfo(&maxlen, false, false)) { 118 nd.nd_flag |= ND_EXTPG; 119 nd.nd_maxextsiz = maxlen; 120 } 121 #endif 122 cacherep = nfs_cbproc(&nd, rqst->rq_xid); 123 } else { 124 NFSMGET(nd.nd_mreq); 125 nd.nd_mreq->m_len = 0; 126 cacherep = RC_REPLY; 127 } 128 if (nd.nd_mrep != NULL) 129 m_freem(nd.nd_mrep); 130 131 if (nd.nd_cred != NULL) 132 crfree(nd.nd_cred); 133 134 if (cacherep == RC_DROPIT) { 135 if (nd.nd_mreq != NULL) 136 m_freem(nd.nd_mreq); 137 svc_freereq(rqst); 138 return; 139 } 140 141 if (nd.nd_mreq == NULL) { 142 svcerr_decode(rqst); 143 svc_freereq(rqst); 144 return; 145 } 146 147 if (nd.nd_repstat & NFSERR_AUTHERR) { 148 svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR); 149 if (nd.nd_mreq != NULL) 150 m_freem(nd.nd_mreq); 151 } else if (!svc_sendreply_mbuf(rqst, nd.nd_mreq)) 152 svcerr_systemerr(rqst); 153 else 154 NFSCL_DEBUG(1, "cbrep sent\n"); 155 svc_freereq(rqst); 156 } 157 158 /* 159 * Check the cache and, optionally, do the RPC. 160 * Return the appropriate cache response. 161 */ 162 static int 163 nfs_cbproc(struct nfsrv_descript *nd, u_int32_t xid) 164 { 165 struct thread *td = curthread; 166 int cacherep; 167 168 if (nd->nd_nam2 == NULL) 169 nd->nd_flag |= ND_STREAMSOCK; 170 171 nfscl_docb(nd, td); 172 if (nd->nd_repstat == NFSERR_DONTREPLY) 173 cacherep = RC_DROPIT; 174 else 175 cacherep = RC_REPLY; 176 return (cacherep); 177 } 178 179 /* 180 * Adds a socket to the list for servicing by nfscbds. 181 */ 182 int 183 nfscbd_addsock(struct file *fp) 184 { 185 int siz; 186 struct socket *so; 187 int error; 188 SVCXPRT *xprt; 189 190 so = fp->f_data; 191 192 siz = sb_max_adj; 193 error = soreserve(so, siz, siz); 194 if (error) 195 return (error); 196 197 /* 198 * Steal the socket from userland so that it doesn't close 199 * unexpectedly. 200 */ 201 if (so->so_type == SOCK_DGRAM) 202 xprt = svc_dg_create(nfscbd_pool, so, 0, 0); 203 else 204 xprt = svc_vc_create(nfscbd_pool, so, 0, 0); 205 if (xprt) { 206 fp->f_ops = &badfileops; 207 fp->f_data = NULL; 208 svc_reg(xprt, NFS_CALLBCKPROG, NFSV4_CBVERS, nfscb_program, 209 NULL); 210 SVC_RELEASE(xprt); 211 } 212 213 return (0); 214 } 215 216 /* 217 * Called by nfssvc() for nfscbds. Just loops around servicing rpc requests 218 * until it is killed by a signal. 219 * 220 * For now, only support callbacks via RPCSEC_GSS if there is a KerberosV 221 * keytab entry with a host based entry in it on the client. (I'm not even 222 * sure that getting Acceptor credentials for a user principal with a 223 * credentials cache is possible, but even if it is, major changes to the 224 * kgssapi would be required.) 225 * I don't believe that this is a serious limitation since, as of 2009, most 226 * NFSv4 servers supporting callbacks are using AUTH_SYS for callbacks even 227 * when the client is using RPCSEC_GSS. (This BSD server uses AUTH_SYS 228 * for callbacks unless nfsrv_gsscallbackson is set non-zero.) 229 */ 230 int 231 nfscbd_nfsd(struct thread *td, struct nfsd_nfscbd_args *args) 232 { 233 char principal[128]; 234 int error; 235 236 if (args != NULL) { 237 error = copyinstr(args->principal, principal, 238 sizeof(principal), NULL); 239 if (error) 240 return (error); 241 } else { 242 principal[0] = '\0'; 243 } 244 245 /* 246 * Only the first nfsd actually does any work. The RPC code 247 * adds threads to it as needed. Any extra processes offered 248 * by nfsd just exit. If nfsd is new enough, it will call us 249 * once with a structure that specifies how many threads to 250 * use. 251 */ 252 NFSD_LOCK(); 253 if (nfs_numnfscbd == 0) { 254 nfs_numnfscbd++; 255 256 NFSD_UNLOCK(); 257 258 if (principal[0] != '\0') 259 rpc_gss_set_svc_name_call(principal, "kerberosv5", 260 GSS_C_INDEFINITE, NFS_CALLBCKPROG, NFSV4_CBVERS); 261 262 nfscbd_pool->sp_minthreads = 4; 263 nfscbd_pool->sp_maxthreads = 4; 264 265 svc_run(nfscbd_pool); 266 267 rpc_gss_clear_svc_name_call(NFS_CALLBCKPROG, NFSV4_CBVERS); 268 269 NFSD_LOCK(); 270 nfs_numnfscbd--; 271 nfsrvd_cbinit(1); 272 } 273 NFSD_UNLOCK(); 274 275 return (0); 276 } 277 278 /* 279 * Initialize the data structures for the server. 280 * Handshake with any new nfsds starting up to avoid any chance of 281 * corruption. 282 */ 283 void 284 nfsrvd_cbinit(int terminating) 285 { 286 287 NFSD_LOCK_ASSERT(); 288 289 if (terminating) { 290 /* Wait for any xprt registrations to complete. */ 291 while (nfs_numnfscbd > 0) 292 msleep(&nfs_numnfscbd, NFSDLOCKMUTEXPTR, PZERO, 293 "nfscbdt", 0); 294 if (nfscbd_pool != NULL) { 295 NFSD_UNLOCK(); 296 svcpool_close(nfscbd_pool); 297 NFSD_LOCK(); 298 } 299 } 300 301 if (nfscbd_pool == NULL) { 302 NFSD_UNLOCK(); 303 nfscbd_pool = svcpool_create("nfscbd", NULL); 304 nfscbd_pool->sp_rcache = NULL; 305 nfscbd_pool->sp_assign = NULL; 306 nfscbd_pool->sp_done = NULL; 307 NFSD_LOCK(); 308 } 309 } 310