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