1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/ 5 * Authors: Doug Rabson <dfr@rabson.org> 6 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org> 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 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/mbuf.h> 37 38 #include <rpc/types.h> 39 #include <rpc/xdr.h> 40 41 static void xdrmbuf_destroy(XDR *); 42 static bool_t xdrmbuf_getlong(XDR *, long *); 43 static bool_t xdrmbuf_putlong(XDR *, const long *); 44 static bool_t xdrmbuf_getbytes(XDR *, char *, u_int); 45 static bool_t xdrmbuf_putbytes(XDR *, const char *, u_int); 46 /* XXX: w/64-bit pointers, u_int not enough! */ 47 static u_int xdrmbuf_getpos(XDR *); 48 static bool_t xdrmbuf_setpos(XDR *, u_int); 49 static int32_t *xdrmbuf_inline(XDR *, u_int); 50 51 static const struct xdr_ops xdrmbuf_ops = { 52 xdrmbuf_getlong, 53 xdrmbuf_putlong, 54 xdrmbuf_getbytes, 55 xdrmbuf_putbytes, 56 xdrmbuf_getpos, 57 xdrmbuf_setpos, 58 xdrmbuf_inline, 59 xdrmbuf_destroy 60 }; 61 62 /* 63 * The procedure xdrmbuf_create initializes a stream descriptor for a 64 * mbuf. 65 */ 66 void 67 xdrmbuf_create(XDR *xdrs, struct mbuf *m, enum xdr_op op) 68 { 69 70 KASSERT(m != NULL, ("xdrmbuf_create with NULL mbuf chain")); 71 xdrs->x_op = op; 72 xdrs->x_ops = &xdrmbuf_ops; 73 xdrs->x_base = (char *) m; 74 if (op == XDR_ENCODE) { 75 m = m_last(m); 76 xdrs->x_private = m; 77 xdrs->x_handy = m->m_len; 78 } else { 79 xdrs->x_private = m; 80 xdrs->x_handy = 0; 81 } 82 } 83 84 void 85 xdrmbuf_append(XDR *xdrs, struct mbuf *madd) 86 { 87 struct mbuf *m; 88 89 KASSERT(xdrs->x_ops == &xdrmbuf_ops && xdrs->x_op == XDR_ENCODE, 90 ("xdrmbuf_append: invalid XDR stream")); 91 92 if (m_length(madd, NULL) == 0) { 93 m_freem(madd); 94 return; 95 } 96 97 m = (struct mbuf *) xdrs->x_private; 98 m->m_next = madd; 99 100 m = m_last(madd); 101 xdrs->x_private = m; 102 xdrs->x_handy = m->m_len; 103 } 104 105 struct mbuf * 106 xdrmbuf_getall(XDR *xdrs) 107 { 108 struct mbuf *m0, *m; 109 110 KASSERT(xdrs->x_ops == &xdrmbuf_ops && xdrs->x_op == XDR_DECODE, 111 ("xdrmbuf_append: invalid XDR stream")); 112 113 m0 = (struct mbuf *) xdrs->x_base; 114 m = (struct mbuf *) xdrs->x_private; 115 if (m0 != m) { 116 while (m0->m_next != m) 117 m0 = m0->m_next; 118 m0->m_next = NULL; 119 xdrs->x_private = NULL; 120 } else { 121 xdrs->x_base = NULL; 122 xdrs->x_private = NULL; 123 } 124 125 if (m) 126 m_adj(m, xdrs->x_handy); 127 else 128 m = m_get(M_WAITOK, MT_DATA); 129 return (m); 130 } 131 132 static void 133 xdrmbuf_destroy(XDR *xdrs) 134 { 135 136 if (xdrs->x_op == XDR_DECODE && xdrs->x_base) { 137 m_freem((struct mbuf *) xdrs->x_base); 138 xdrs->x_base = NULL; 139 xdrs->x_private = NULL; 140 } 141 } 142 143 static bool_t 144 xdrmbuf_getlong(XDR *xdrs, long *lp) 145 { 146 int32_t *p; 147 int32_t t; 148 149 p = xdrmbuf_inline(xdrs, sizeof(int32_t)); 150 if (p) { 151 t = *p; 152 } else { 153 xdrmbuf_getbytes(xdrs, (char *) &t, sizeof(int32_t)); 154 } 155 156 *lp = ntohl(t); 157 return (TRUE); 158 } 159 160 static bool_t 161 xdrmbuf_putlong(xdrs, lp) 162 XDR *xdrs; 163 const long *lp; 164 { 165 int32_t *p; 166 int32_t t = htonl(*lp); 167 168 p = xdrmbuf_inline(xdrs, sizeof(int32_t)); 169 if (p) { 170 *p = t; 171 return (TRUE); 172 } else { 173 return (xdrmbuf_putbytes(xdrs, (char *) &t, sizeof(int32_t))); 174 } 175 } 176 177 static bool_t 178 xdrmbuf_getbytes(XDR *xdrs, char *addr, u_int len) 179 { 180 struct mbuf *m = (struct mbuf *) xdrs->x_private; 181 size_t sz; 182 183 while (len > 0) { 184 /* 185 * Make sure we haven't hit the end. 186 */ 187 if (!m) { 188 return (FALSE); 189 } 190 191 /* 192 * See how much we can get from this mbuf. 193 */ 194 sz = m->m_len - xdrs->x_handy; 195 if (sz > len) 196 sz = len; 197 bcopy(mtod(m, const char *) + xdrs->x_handy, addr, sz); 198 199 addr += sz; 200 xdrs->x_handy += sz; 201 len -= sz; 202 203 if (xdrs->x_handy == m->m_len) { 204 m = m->m_next; 205 xdrs->x_private = (void *) m; 206 xdrs->x_handy = 0; 207 } 208 } 209 210 return (TRUE); 211 } 212 213 static bool_t 214 xdrmbuf_putbytes(XDR *xdrs, const char *addr, u_int len) 215 { 216 struct mbuf *m = (struct mbuf *) xdrs->x_private; 217 struct mbuf *n; 218 size_t sz; 219 220 while (len > 0) { 221 sz = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 222 if (sz > len) 223 sz = len; 224 bcopy(addr, mtod(m, char *) + xdrs->x_handy, sz); 225 addr += sz; 226 xdrs->x_handy += sz; 227 if (xdrs->x_handy > m->m_len) 228 m->m_len = xdrs->x_handy; 229 len -= sz; 230 231 if (xdrs->x_handy == m->m_len && M_TRAILINGSPACE(m) == 0) { 232 if (!m->m_next) { 233 if (m->m_flags & M_EXT) 234 n = m_getcl(M_WAITOK, m->m_type, 0); 235 else 236 n = m_get(M_WAITOK, m->m_type); 237 m->m_next = n; 238 } 239 m = m->m_next; 240 xdrs->x_private = (void *) m; 241 xdrs->x_handy = 0; 242 } 243 } 244 245 return (TRUE); 246 } 247 248 static u_int 249 xdrmbuf_getpos(XDR *xdrs) 250 { 251 struct mbuf *m0 = (struct mbuf *) xdrs->x_base; 252 struct mbuf *m = (struct mbuf *) xdrs->x_private; 253 u_int pos = 0; 254 255 while (m0 && m0 != m) { 256 pos += m0->m_len; 257 m0 = m0->m_next; 258 } 259 KASSERT(m0, ("Corrupted mbuf chain")); 260 261 return (pos + xdrs->x_handy); 262 } 263 264 static bool_t 265 xdrmbuf_setpos(XDR *xdrs, u_int pos) 266 { 267 struct mbuf *m = (struct mbuf *) xdrs->x_base; 268 269 while (m && pos > m->m_len) { 270 pos -= m->m_len; 271 m = m->m_next; 272 } 273 KASSERT(m, ("Corrupted mbuf chain")); 274 275 xdrs->x_private = (void *) m; 276 xdrs->x_handy = pos; 277 278 return (TRUE); 279 } 280 281 static int32_t * 282 xdrmbuf_inline(XDR *xdrs, u_int len) 283 { 284 struct mbuf *m = (struct mbuf *) xdrs->x_private; 285 size_t available; 286 char *p; 287 288 if (!m) 289 return (0); 290 if (xdrs->x_op == XDR_ENCODE) { 291 available = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 292 } else { 293 available = m->m_len - xdrs->x_handy; 294 } 295 296 if (available >= len) { 297 p = mtod(m, char *) + xdrs->x_handy; 298 if (((uintptr_t) p) & (sizeof(int32_t) - 1)) 299 return (0); 300 xdrs->x_handy += len; 301 if (xdrs->x_handy > m->m_len) 302 m->m_len = xdrs->x_handy; 303 return ((int32_t *) p); 304 } 305 306 return (0); 307 } 308