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 * 4. 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 * @(#)nfs_subs.c 8.8 (Berkeley) 5/22/95 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD$"); 37 38/* 39 * These functions support the macros and help fiddle mbuf chains for 40 * the nfs op functions. They do things like create the rpc header and 41 * copy data between mbuf chains and uio lists. 42 */ 43 44#include <sys/param.h> 45#include <sys/systm.h> 46#include <sys/kernel.h> 47#include <sys/bio.h> 48#include <sys/buf.h> 49#include <sys/proc.h> 50#include <sys/mount.h> 51#include <sys/vnode.h> 52#include <sys/namei.h> 53#include <sys/mbuf.h> 54#include <sys/socket.h> 55#include <sys/stat.h> 56#include <sys/malloc.h> 57#include <sys/module.h> 58#include <sys/sysent.h> 59#include <sys/syscall.h> 60#include <sys/sysctl.h> 61 62#include <vm/vm.h> 63#include <vm/vm_object.h> 64#include <vm/vm_extern.h> 65 66#include <nfs/nfsproto.h> 67#include <nfsserver/nfs.h> 68#include <nfs/xdr_subs.h> 69#include <nfs/nfs_common.h> 70 71#include <netinet/in.h> 72 73enum vtype nv3tov_type[8]= { 74 VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO 75}; 76nfstype nfsv3_type[9] = { 77 NFNON, NFREG, NFDIR, NFBLK, NFCHR, NFLNK, NFSOCK, NFFIFO, NFNON 78}; 79 80static void *nfsm_dissect_xx_sub(int s, struct mbuf **md, caddr_t *dpos, 81 int how); 82 83SYSCTL_NODE(_vfs, OID_AUTO, nfs_common, CTLFLAG_RD, 0, "NFS common support"); 84 85static int nfs_realign_test; 86SYSCTL_INT(_vfs_nfs_common, OID_AUTO, realign_test, CTLFLAG_RD, 87 &nfs_realign_test, 0, "Number of realign tests done"); 88 89static int nfs_realign_count; 90SYSCTL_INT(_vfs_nfs_common, OID_AUTO, realign_count, CTLFLAG_RD, 91 &nfs_realign_count, 0, "Number of mbuf realignments done"); 92 93/* 94 * copies mbuf chain to the uio scatter/gather list 95 */ 96int 97nfsm_mbuftouio(struct mbuf **mrep, struct uio *uiop, int siz, caddr_t *dpos) 98{ 99 char *mbufcp, *uiocp; 100 int xfer, left, len; 101 struct mbuf *mp; 102 long uiosiz, rem; 103 int error = 0; 104 105 mp = *mrep; 106 mbufcp = *dpos; 107 len = mtod(mp, caddr_t)+mp->m_len-mbufcp; 108 rem = nfsm_rndup(siz)-siz; 109 while (siz > 0) { 110 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL) 111 return (EFBIG); 112 left = uiop->uio_iov->iov_len; 113 uiocp = uiop->uio_iov->iov_base; 114 if (left > siz) 115 left = siz; 116 uiosiz = left; 117 while (left > 0) { 118 while (len == 0) { 119 mp = mp->m_next; 120 if (mp == NULL) 121 return (EBADRPC); 122 mbufcp = mtod(mp, caddr_t); 123 len = mp->m_len; 124 } 125 xfer = (left > len) ? len : left; 126#ifdef notdef 127 /* Not Yet.. */ 128 if (uiop->uio_iov->iov_op != NULL) 129 (*(uiop->uio_iov->iov_op)) 130 (mbufcp, uiocp, xfer); 131 else 132#endif 133 if (uiop->uio_segflg == UIO_SYSSPACE) 134 bcopy(mbufcp, uiocp, xfer); 135 else 136 copyout(mbufcp, uiocp, xfer); 137 left -= xfer; 138 len -= xfer; 139 mbufcp += xfer; 140 uiocp += xfer; 141 uiop->uio_offset += xfer; 142 uiop->uio_resid -= xfer; 143 } 144 if (uiop->uio_iov->iov_len <= siz) { 145 uiop->uio_iovcnt--; 146 uiop->uio_iov++; 147 } else { 148 uiop->uio_iov->iov_base = 149 (char *)uiop->uio_iov->iov_base + uiosiz; 150 uiop->uio_iov->iov_len -= uiosiz; 151 } 152 siz -= uiosiz; 153 } 154 *dpos = mbufcp; 155 *mrep = mp; 156 if (rem > 0) { 157 if (len < rem) 158 error = nfs_adv(mrep, dpos, rem, len); 159 else 160 *dpos += rem; 161 } 162 return (error); 163} 164 165/* 166 * Help break down an mbuf chain by setting the first siz bytes contiguous 167 * pointed to by returned val. 168 * This is used by the macros nfsm_dissect for tough 169 * cases. (The macros use the vars. dpos and dpos2) 170 */ 171void * 172nfsm_disct(struct mbuf **mdp, caddr_t *dposp, int siz, int left, int how) 173{ 174 struct mbuf *mp, *mp2; 175 int siz2, xfer; 176 caddr_t ptr, npos = NULL; 177 void *ret; 178 179 mp = *mdp; 180 while (left == 0) { 181 *mdp = mp = mp->m_next; 182 if (mp == NULL) 183 return (NULL); 184 left = mp->m_len; 185 *dposp = mtod(mp, caddr_t); 186 } 187 if (left >= siz) { 188 ret = *dposp; 189 *dposp += siz; 190 } else if (mp->m_next == NULL) { 191 return (NULL); 192 } else if (siz > MHLEN) { 193 panic("nfs S too big"); 194 } else { 195 mp2 = m_get(how, MT_DATA); 196 if (mp2 == NULL) 197 return (NULL); 198 mp2->m_len = siz; 199 mp2->m_next = mp->m_next; 200 mp->m_next = mp2; 201 mp->m_len -= left; 202 mp = mp2; 203 ptr = mtod(mp, caddr_t); 204 ret = ptr; 205 bcopy(*dposp, ptr, left); /* Copy what was left */ 206 siz2 = siz-left; 207 ptr += left; 208 mp2 = mp->m_next; 209 npos = mtod(mp2, caddr_t); 210 /* Loop around copying up the siz2 bytes */ 211 while (siz2 > 0) { 212 if (mp2 == NULL) 213 return (NULL); 214 xfer = (siz2 > mp2->m_len) ? mp2->m_len : siz2; 215 if (xfer > 0) { 216 bcopy(mtod(mp2, caddr_t), ptr, xfer); 217 mp2->m_data += xfer; 218 mp2->m_len -= xfer; 219 ptr += xfer; 220 siz2 -= xfer; 221 } 222 if (siz2 > 0) { 223 mp2 = mp2->m_next; 224 if (mp2 != NULL) 225 npos = mtod(mp2, caddr_t); 226 } 227 } 228 *mdp = mp2; 229 *dposp = mtod(mp2, caddr_t); 230 if (!nfsm_aligned(*dposp, u_int32_t)) { 231 bcopy(*dposp, npos, mp2->m_len); 232 mp2->m_data = npos; 233 *dposp = npos; 234 } 235 } 236 return (ret); 237} 238 239/* 240 * Advance the position in the mbuf chain. 241 */ 242int 243nfs_adv(struct mbuf **mdp, caddr_t *dposp, int offs, int left) 244{ 245 struct mbuf *m; 246 int s; 247 248 m = *mdp; 249 s = left; 250 while (s < offs) { 251 offs -= s; 252 m = m->m_next; 253 if (m == NULL) 254 return (EBADRPC); 255 s = m->m_len; 256 } 257 *mdp = m; 258 *dposp = mtod(m, caddr_t)+offs; 259 return (0); 260} 261 262void * 263nfsm_build_xx(int s, struct mbuf **mb, caddr_t *bpos) 264{ 265 struct mbuf *mb2; 266 void *ret; 267 268 if (s > M_TRAILINGSPACE(*mb)) { 269 mb2 = m_get(M_WAITOK, MT_DATA); 270 if (s > MLEN) 271 panic("build > MLEN"); 272 (*mb)->m_next = mb2; 273 *mb = mb2; 274 (*mb)->m_len = 0; 275 *bpos = mtod(*mb, caddr_t); 276 } 277 ret = *bpos; 278 (*mb)->m_len += s; 279 *bpos += s; 280 return (ret); 281} 282 283void * 284nfsm_dissect_xx(int s, struct mbuf **md, caddr_t *dpos) 285{ 286 287 return (nfsm_dissect_xx_sub(s, md, dpos, M_WAITOK)); 288} 289 290void * 291nfsm_dissect_xx_nonblock(int s, struct mbuf **md, caddr_t *dpos) 292{ 293 294 return (nfsm_dissect_xx_sub(s, md, dpos, M_NOWAIT)); 295} 296 297static void * 298nfsm_dissect_xx_sub(int s, struct mbuf **md, caddr_t *dpos, int how) 299{ 300 int t1; 301 char *cp2; 302 void *ret; 303 304 t1 = mtod(*md, caddr_t) + (*md)->m_len - *dpos; 305 if (t1 >= s) { 306 ret = *dpos; 307 *dpos += s; 308 return (ret); 309 } 310 cp2 = nfsm_disct(md, dpos, s, t1, how); 311 return (cp2); 312} 313 314int 315nfsm_strsiz_xx(int *s, int m, struct mbuf **mb, caddr_t *bpos) 316{ 317 u_int32_t *tl; 318 319 tl = nfsm_dissect_xx(NFSX_UNSIGNED, mb, bpos); 320 if (tl == NULL) 321 return (EBADRPC); 322 *s = fxdr_unsigned(int32_t, *tl); 323 if (*s > m) 324 return (EBADRPC); 325 return (0); 326} 327 328int 329nfsm_adv_xx(int s, struct mbuf **md, caddr_t *dpos) 330{ 331 int t1; 332 333 t1 = mtod(*md, caddr_t) + (*md)->m_len - *dpos; 334 if (t1 >= s) { 335 *dpos += s; 336 return (0); 337 } 338 t1 = nfs_adv(md, dpos, s, t1); 339 if (t1) 340 return (t1); 341 return (0); 342} 343 344/* 345 * Check for badly aligned mbuf data and realign by copying the unaligned 346 * portion of the data into a new mbuf chain and freeing the portions of the 347 * old chain that were replaced. 348 * 349 * We cannot simply realign the data within the existing mbuf chain because 350 * the underlying buffers may contain other rpc commands and we cannot afford 351 * to overwrite them. 352 * 353 * We would prefer to avoid this situation entirely. The situation does not 354 * occur with NFS/UDP and is supposed to only occassionally occur with TCP. 355 * Use vfs.nfs_common.realign_count and realign_test to check this. 356 */ 357int 358nfs_realign(struct mbuf **pm, int how) 359{ 360 struct mbuf *m, *n; 361 int off; 362 363 ++nfs_realign_test; 364 while ((m = *pm) != NULL) { 365 if (!nfsm_aligned(m->m_len, u_int32_t) || 366 !nfsm_aligned(mtod(m, intptr_t), u_int32_t)) { 367 /* 368 * NB: we can't depend on m_pkthdr.len to help us 369 * decide what to do here. May not be worth doing 370 * the m_length calculation as m_copyback will 371 * expand the mbuf chain below as needed. 372 */ 373 if (m_length(m, NULL) >= MINCLSIZE) { 374 /* NB: m_copyback handles space > MCLBYTES */ 375 n = m_getcl(how, MT_DATA, 0); 376 } else 377 n = m_get(how, MT_DATA); 378 if (n == NULL) 379 return (ENOMEM); 380 /* 381 * Align the remainder of the mbuf chain. 382 */ 383 n->m_len = 0; 384 off = 0; 385 while (m != NULL) { 386 m_copyback(n, off, m->m_len, mtod(m, caddr_t)); 387 off += m->m_len; 388 m = m->m_next; 389 } 390 m_freem(*pm); 391 *pm = n; 392 ++nfs_realign_count; 393 break; 394 } 395 pm = &m->m_next; 396 } 397 return (0); 398} 399 400static moduledata_t nfs_common_mod = { 401 "nfs_common", 402 NULL, 403 NULL 404}; 405 406DECLARE_MODULE(nfs_common, nfs_common_mod, SI_SUB_VFS, SI_ORDER_ANY); 407MODULE_VERSION(nfs_common, 1); 408