1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/malloc.h> 34 #include <sys/mbuf.h> 35 36 #include <rpc/types.h> 37 #include <rpc/xdr.h> 38 39 static void xdrmbuf_destroy(XDR *); 40 static bool_t xdrmbuf_getlong(XDR *, long *); 41 static bool_t xdrmbuf_putlong(XDR *, const long *); 42 static bool_t xdrmbuf_getbytes(XDR *, char *, u_int); 43 static bool_t xdrmbuf_putbytes(XDR *, const char *, u_int); 44 /* XXX: w/64-bit pointers, u_int not enough! */ 45 static u_int xdrmbuf_getpos(XDR *); 46 static bool_t xdrmbuf_setpos(XDR *, u_int); 47 static int32_t *xdrmbuf_inline(XDR *, u_int); 48 49 static const struct xdr_ops xdrmbuf_ops = { 50 xdrmbuf_getlong, 51 xdrmbuf_putlong, 52 xdrmbuf_getbytes, 53 xdrmbuf_putbytes, 54 xdrmbuf_getpos, 55 xdrmbuf_setpos, 56 xdrmbuf_inline, 57 xdrmbuf_destroy 58 }; 59 60 /* 61 * The procedure xdrmbuf_create initializes a stream descriptor for a 62 * mbuf. 63 */ 64 void 65 xdrmbuf_create(XDR *xdrs, struct mbuf *m, enum xdr_op op) 66 { 67 68 KASSERT(m != NULL, ("xdrmbuf_create with NULL mbuf chain")); 69 xdrs->x_op = op; 70 xdrs->x_ops = &xdrmbuf_ops; 71 xdrs->x_base = (char *) m; 72 if (op == XDR_ENCODE) { 73 m = m_last(m); 74 xdrs->x_private = m; 75 xdrs->x_handy = m->m_len; 76 } else { 77 xdrs->x_private = m; 78 xdrs->x_handy = 0; 79 } 80 } 81 82 void 83 xdrmbuf_append(XDR *xdrs, struct mbuf *madd) 84 { 85 struct mbuf *m; 86 87 KASSERT(xdrs->x_ops == &xdrmbuf_ops && xdrs->x_op == XDR_ENCODE, 88 ("xdrmbuf_append: invalid XDR stream")); 89 90 if (m_length(madd, NULL) == 0) { 91 m_freem(madd); 92 return; 93 } 94 95 m = (struct mbuf *) xdrs->x_private; 96 m->m_next = madd; 97 98 m = m_last(madd); 99 xdrs->x_private = m; 100 xdrs->x_handy = m->m_len; 101 } 102 103 struct mbuf * 104 xdrmbuf_getall(XDR *xdrs) 105 { 106 struct mbuf *m0, *m; 107 108 KASSERT(xdrs->x_ops == &xdrmbuf_ops && xdrs->x_op == XDR_DECODE, 109 ("xdrmbuf_append: invalid XDR stream")); 110 111 m0 = (struct mbuf *) xdrs->x_base; 112 m = (struct mbuf *) xdrs->x_private; 113 if (m0 != m) { 114 while (m0->m_next != m) 115 m0 = m0->m_next; 116 m0->m_next = NULL; 117 xdrs->x_private = NULL; 118 } else { 119 xdrs->x_base = NULL; 120 xdrs->x_private = NULL; 121 } 122 123 if (m) 124 m_adj(m, xdrs->x_handy); 125 else 126 m = m_get(M_WAITOK, MT_DATA); 127 return (m); 128 } 129 130 static void 131 xdrmbuf_destroy(XDR *xdrs) 132 { 133 134 if (xdrs->x_op == XDR_DECODE && xdrs->x_base) { 135 m_freem((struct mbuf *) xdrs->x_base); 136 xdrs->x_base = NULL; 137 xdrs->x_private = NULL; 138 } 139 } 140 141 static bool_t 142 xdrmbuf_getlong(XDR *xdrs, long *lp) 143 { 144 int32_t *p; 145 int32_t t; 146 147 p = xdrmbuf_inline(xdrs, sizeof(int32_t)); 148 if (p) { 149 t = *p; 150 } else { 151 xdrmbuf_getbytes(xdrs, (char *) &t, sizeof(int32_t)); 152 } 153 154 *lp = ntohl(t); 155 return (TRUE); 156 } 157 158 static bool_t 159 xdrmbuf_putlong(XDR *xdrs, const long *lp) 160 { 161 int32_t *p; 162 int32_t t = htonl(*lp); 163 164 p = xdrmbuf_inline(xdrs, sizeof(int32_t)); 165 if (p) { 166 *p = t; 167 return (TRUE); 168 } else { 169 return (xdrmbuf_putbytes(xdrs, (char *) &t, sizeof(int32_t))); 170 } 171 } 172 173 static bool_t 174 xdrmbuf_getbytes(XDR *xdrs, char *addr, u_int len) 175 { 176 struct mbuf *m = (struct mbuf *) xdrs->x_private; 177 size_t sz; 178 179 while (len > 0) { 180 /* 181 * Make sure we haven't hit the end. 182 */ 183 if (!m) { 184 return (FALSE); 185 } 186 187 /* 188 * See how much we can get from this mbuf. 189 */ 190 sz = m->m_len - xdrs->x_handy; 191 if (sz > len) 192 sz = len; 193 bcopy(mtod(m, const char *) + xdrs->x_handy, addr, sz); 194 195 addr += sz; 196 xdrs->x_handy += sz; 197 len -= sz; 198 199 if (xdrs->x_handy == m->m_len) { 200 m = m->m_next; 201 xdrs->x_private = (void *) m; 202 xdrs->x_handy = 0; 203 } 204 } 205 206 return (TRUE); 207 } 208 209 static bool_t 210 xdrmbuf_putbytes(XDR *xdrs, const char *addr, u_int len) 211 { 212 struct mbuf *m = (struct mbuf *) xdrs->x_private; 213 struct mbuf *n; 214 size_t sz; 215 216 while (len > 0) { 217 sz = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 218 if (sz > len) 219 sz = len; 220 bcopy(addr, mtod(m, char *) + xdrs->x_handy, sz); 221 addr += sz; 222 xdrs->x_handy += sz; 223 if (xdrs->x_handy > m->m_len) 224 m->m_len = xdrs->x_handy; 225 len -= sz; 226 227 if (xdrs->x_handy == m->m_len && M_TRAILINGSPACE(m) == 0) { 228 if (!m->m_next) { 229 if (m->m_flags & M_EXT) 230 n = m_getcl(M_WAITOK, m->m_type, 0); 231 else 232 n = m_get(M_WAITOK, m->m_type); 233 m->m_next = n; 234 } 235 m = m->m_next; 236 xdrs->x_private = (void *) m; 237 xdrs->x_handy = 0; 238 } 239 } 240 241 return (TRUE); 242 } 243 244 static u_int 245 xdrmbuf_getpos(XDR *xdrs) 246 { 247 struct mbuf *m0 = (struct mbuf *) xdrs->x_base; 248 struct mbuf *m = (struct mbuf *) xdrs->x_private; 249 u_int pos = 0; 250 251 while (m0 && m0 != m) { 252 pos += m0->m_len; 253 m0 = m0->m_next; 254 } 255 KASSERT(m0, ("Corrupted mbuf chain")); 256 257 return (pos + xdrs->x_handy); 258 } 259 260 static bool_t 261 xdrmbuf_setpos(XDR *xdrs, u_int pos) 262 { 263 struct mbuf *m = (struct mbuf *) xdrs->x_base; 264 265 while (m && pos > m->m_len) { 266 pos -= m->m_len; 267 m = m->m_next; 268 } 269 KASSERT(m, ("Corrupted mbuf chain")); 270 271 xdrs->x_private = (void *) m; 272 xdrs->x_handy = pos; 273 274 return (TRUE); 275 } 276 277 static int32_t * 278 xdrmbuf_inline(XDR *xdrs, u_int len) 279 { 280 struct mbuf *m = (struct mbuf *) xdrs->x_private; 281 size_t available; 282 char *p; 283 284 if (!m) 285 return (0); 286 if (xdrs->x_op == XDR_ENCODE) { 287 available = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 288 } else { 289 available = m->m_len - xdrs->x_handy; 290 } 291 292 if (available >= len) { 293 p = mtod(m, char *) + xdrs->x_handy; 294 if (((uintptr_t) p) & (sizeof(int32_t) - 1)) 295 return (0); 296 xdrs->x_handy += len; 297 if (xdrs->x_handy > m->m_len) 298 m->m_len = xdrs->x_handy; 299 return ((int32_t *) p); 300 } 301 302 return (0); 303 } 304