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: stable/9/sys/nfs/nfs_common.c 247502 2013-02-28 21:57:38Z jhb $");
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
73 enum vtype nv3tov_type[8]= {
74 VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO
75 };
76 nfstype nfsv3_type[9] = {
77 NFNON, NFREG, NFDIR, NFBLK, NFCHR, NFLNK, NFSOCK, NFFIFO, NFNON
78 };
79
80 static void *nfsm_dissect_xx_sub(int s, struct mbuf **md, caddr_t *dpos,
81 int how);
82
83 SYSCTL_NODE(_vfs, OID_AUTO, nfs_common, CTLFLAG_RD, 0, "NFS common support");
84
85 static int nfs_realign_test;
86 SYSCTL_INT(_vfs_nfs_common, OID_AUTO, realign_test, CTLFLAG_RD,
87 &nfs_realign_test, 0, "Number of realign tests done");
88
89 static int nfs_realign_count;
90 SYSCTL_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 */
96 int
nfsm_mbuftouio(struct mbuf ** mrep,struct uio * uiop,int siz,caddr_t * dpos)97 nfsm_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 */
171 void *
nfsm_disct(struct mbuf ** mdp,caddr_t * dposp,int siz,int left,int how)172 nfsm_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 MGET(mp2, 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 */
242 int
nfs_adv(struct mbuf ** mdp,caddr_t * dposp,int offs,int left)243 nfs_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
262 void *
nfsm_build_xx(int s,struct mbuf ** mb,caddr_t * bpos)263 nfsm_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 MGET(mb2, M_WAIT, 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
283 void *
nfsm_dissect_xx(int s,struct mbuf ** md,caddr_t * dpos)284 nfsm_dissect_xx(int s, struct mbuf **md, caddr_t *dpos)
285 {
286
287 return (nfsm_dissect_xx_sub(s, md, dpos, M_WAIT));
288 }
289
290 void *
nfsm_dissect_xx_nonblock(int s,struct mbuf ** md,caddr_t * dpos)291 nfsm_dissect_xx_nonblock(int s, struct mbuf **md, caddr_t *dpos)
292 {
293
294 return (nfsm_dissect_xx_sub(s, md, dpos, M_DONTWAIT));
295 }
296
297 static void *
nfsm_dissect_xx_sub(int s,struct mbuf ** md,caddr_t * dpos,int how)298 nfsm_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
314 int
nfsm_strsiz_xx(int * s,int m,struct mbuf ** mb,caddr_t * bpos)315 nfsm_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
328 int
nfsm_adv_xx(int s,struct mbuf ** md,caddr_t * dpos)329 nfsm_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 */
357 int
nfs_realign(struct mbuf ** pm,int how)358 nfs_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
400 static moduledata_t nfs_common_mod = {
401 "nfs_common",
402 NULL,
403 NULL
404 };
405
406 DECLARE_MODULE(nfs_common, nfs_common_mod, SI_SUB_VFS, SI_ORDER_ANY);
407 MODULE_VERSION(nfs_common, 1);
408