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 50 NFSDLOCKMUTEX; 51 52 extern SVCPOOL *nfscbd_pool; 53 54 static int nfs_cbproc(struct nfsrv_descript *, u_int32_t); 55 56 extern u_long sb_max_adj; 57 extern int nfs_numnfscbd; 58 extern int nfscl_debuglevel; 59 60 /* 61 * NFS client system calls for handling callbacks. 62 */ 63 64 /* 65 * Handles server to client callbacks. 66 */ 67 static void 68 nfscb_program(struct svc_req *rqst, SVCXPRT *xprt) 69 { 70 struct nfsrv_descript nd; 71 int cacherep, credflavor; 72 #ifdef KERN_TLS 73 u_int maxlen; 74 #endif 75 76 memset(&nd, 0, sizeof(nd)); 77 if (rqst->rq_proc != NFSPROC_NULL && 78 rqst->rq_proc != NFSV4PROC_CBCOMPOUND) { 79 svcerr_noproc(rqst); 80 svc_freereq(rqst); 81 return; 82 } 83 nd.nd_procnum = rqst->rq_proc; 84 nd.nd_flag = (ND_NFSCB | ND_NFSV4); 85 86 /* 87 * Note: we want rq_addr, not svc_getrpccaller for nd_nam2 - 88 * NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP 89 * mounts. 90 */ 91 nd.nd_mrep = rqst->rq_args; 92 rqst->rq_args = NULL; 93 newnfs_realign(&nd.nd_mrep, M_WAITOK); 94 nd.nd_md = nd.nd_mrep; 95 nd.nd_dpos = mtod(nd.nd_md, caddr_t); 96 nd.nd_nam = svc_getrpccaller(rqst); 97 nd.nd_nam2 = rqst->rq_addr; 98 nd.nd_mreq = NULL; 99 nd.nd_cred = NULL; 100 101 NFSCL_DEBUG(1, "cbproc=%d\n",nd.nd_procnum); 102 if (nd.nd_procnum != NFSPROC_NULL) { 103 if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) { 104 svcerr_weakauth(rqst); 105 svc_freereq(rqst); 106 m_freem(nd.nd_mrep); 107 return; 108 } 109 110 /* For now, I don't care what credential flavor was used. */ 111 #ifdef notyet 112 #ifdef MAC 113 mac_cred_associate_nfsd(nd.nd_cred); 114 #endif 115 #endif 116 #ifdef KERN_TLS 117 if ((xprt->xp_tls & RPCTLS_FLAGS_HANDSHAKE) != 0 && 118 rpctls_getinfo(&maxlen, false, false)) { 119 nd.nd_flag |= ND_EXTPG; 120 nd.nd_maxextsiz = maxlen; 121 } 122 #endif 123 cacherep = nfs_cbproc(&nd, rqst->rq_xid); 124 } else { 125 NFSMGET(nd.nd_mreq); 126 nd.nd_mreq->m_len = 0; 127 cacherep = RC_REPLY; 128 } 129 if (nd.nd_mrep != NULL) 130 m_freem(nd.nd_mrep); 131 132 if (nd.nd_cred != NULL) 133 crfree(nd.nd_cred); 134 135 if (cacherep == RC_DROPIT) { 136 if (nd.nd_mreq != NULL) 137 m_freem(nd.nd_mreq); 138 svc_freereq(rqst); 139 return; 140 } 141 142 if (nd.nd_mreq == NULL) { 143 svcerr_decode(rqst); 144 svc_freereq(rqst); 145 return; 146 } 147 148 if (nd.nd_repstat & NFSERR_AUTHERR) { 149 svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR); 150 if (nd.nd_mreq != NULL) 151 m_freem(nd.nd_mreq); 152 } else if (!svc_sendreply_mbuf(rqst, nd.nd_mreq)) 153 svcerr_systemerr(rqst); 154 else 155 NFSCL_DEBUG(1, "cbrep sent\n"); 156 svc_freereq(rqst); 157 } 158 159 /* 160 * Check the cache and, optionally, do the RPC. 161 * Return the appropriate cache response. 162 */ 163 static int 164 nfs_cbproc(struct nfsrv_descript *nd, u_int32_t xid) 165 { 166 struct thread *td = curthread; 167 int cacherep; 168 169 if (nd->nd_nam2 == NULL) 170 nd->nd_flag |= ND_STREAMSOCK; 171 172 nfscl_docb(nd, td); 173 if (nd->nd_repstat == NFSERR_DONTREPLY) 174 cacherep = RC_DROPIT; 175 else 176 cacherep = RC_REPLY; 177 return (cacherep); 178 } 179 180 /* 181 * Adds a socket to the list for servicing by nfscbds. 182 */ 183 int 184 nfscbd_addsock(struct file *fp) 185 { 186 int siz; 187 struct socket *so; 188 int error; 189 SVCXPRT *xprt; 190 191 so = fp->f_data; 192 193 siz = sb_max_adj; 194 error = soreserve(so, siz, siz); 195 if (error) 196 return (error); 197 198 /* 199 * Steal the socket from userland so that it doesn't close 200 * unexpectedly. 201 */ 202 if (so->so_type == SOCK_DGRAM) 203 xprt = svc_dg_create(nfscbd_pool, so, 0, 0); 204 else 205 xprt = svc_vc_create(nfscbd_pool, so, 0, 0); 206 if (xprt) { 207 fp->f_ops = &badfileops; 208 fp->f_data = NULL; 209 svc_reg(xprt, NFS_CALLBCKPROG, NFSV4_CBVERS, nfscb_program, 210 NULL); 211 SVC_RELEASE(xprt); 212 } 213 214 return (0); 215 } 216 217 /* 218 * Called by nfssvc() for nfscbds. Just loops around servicing rpc requests 219 * until it is killed by a signal. 220 * 221 * For now, only support callbacks via RPCSEC_GSS if there is a KerberosV 222 * keytab entry with a host based entry in it on the client. (I'm not even 223 * sure that getting Acceptor credentials for a user principal with a 224 * credentials cache is possible, but even if it is, major changes to the 225 * kgssapi would be required.) 226 * I don't believe that this is a serious limitation since, as of 2009, most 227 * NFSv4 servers supporting callbacks are using AUTH_SYS for callbacks even 228 * when the client is using RPCSEC_GSS. (This BSD server uses AUTH_SYS 229 * for callbacks unless nfsrv_gsscallbackson is set non-zero.) 230 */ 231 int 232 nfscbd_nfsd(struct thread *td, struct nfsd_nfscbd_args *args) 233 { 234 char principal[128]; 235 int error; 236 237 if (args != NULL) { 238 error = copyinstr(args->principal, principal, 239 sizeof(principal), NULL); 240 if (error) 241 return (error); 242 } else { 243 principal[0] = '\0'; 244 } 245 246 /* 247 * Only the first nfsd actually does any work. The RPC code 248 * adds threads to it as needed. Any extra processes offered 249 * by nfsd just exit. If nfsd is new enough, it will call us 250 * once with a structure that specifies how many threads to 251 * use. 252 */ 253 NFSD_LOCK(); 254 if (nfs_numnfscbd == 0) { 255 nfs_numnfscbd++; 256 257 NFSD_UNLOCK(); 258 259 if (principal[0] != '\0') 260 rpc_gss_set_svc_name_call(principal, "kerberosv5", 261 GSS_C_INDEFINITE, NFS_CALLBCKPROG, NFSV4_CBVERS); 262 263 nfscbd_pool->sp_minthreads = 4; 264 nfscbd_pool->sp_maxthreads = 4; 265 266 svc_run(nfscbd_pool); 267 268 rpc_gss_clear_svc_name_call(NFS_CALLBCKPROG, NFSV4_CBVERS); 269 270 NFSD_LOCK(); 271 nfs_numnfscbd--; 272 nfsrvd_cbinit(1); 273 } 274 NFSD_UNLOCK(); 275 276 return (0); 277 } 278 279 /* 280 * Initialize the data structures for the server. 281 * Handshake with any new nfsds starting up to avoid any chance of 282 * corruption. 283 */ 284 void 285 nfsrvd_cbinit(int terminating) 286 { 287 288 NFSD_LOCK_ASSERT(); 289 290 if (terminating) { 291 /* Wait for any xprt registrations to complete. */ 292 while (nfs_numnfscbd > 0) 293 msleep(&nfs_numnfscbd, NFSDLOCKMUTEXPTR, PZERO, 294 "nfscbdt", 0); 295 if (nfscbd_pool != NULL) { 296 NFSD_UNLOCK(); 297 svcpool_close(nfscbd_pool); 298 NFSD_LOCK(); 299 } 300 } 301 302 if (nfscbd_pool == NULL) { 303 NFSD_UNLOCK(); 304 nfscbd_pool = svcpool_create("nfscbd", NULL); 305 nfscbd_pool->sp_rcache = NULL; 306 nfscbd_pool->sp_assign = NULL; 307 nfscbd_pool->sp_done = NULL; 308 NFSD_LOCK(); 309 } 310 } 311 312