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/param.h> 31 #include <sys/systm.h> 32 #include <sys/malloc.h> 33 #include <sys/mbuf.h> 34 35 #include <rpc/types.h> 36 #include <rpc/xdr.h> 37 38 static void xdrmbuf_destroy(XDR *); 39 static bool_t xdrmbuf_getlong(XDR *, long *); 40 static bool_t xdrmbuf_putlong(XDR *, const long *); 41 static bool_t xdrmbuf_getbytes(XDR *, char *, u_int); 42 static bool_t xdrmbuf_putbytes(XDR *, const char *, u_int); 43 /* XXX: w/64-bit pointers, u_int not enough! */ 44 static u_int xdrmbuf_getpos(XDR *); 45 static bool_t xdrmbuf_setpos(XDR *, u_int); 46 static int32_t *xdrmbuf_inline(XDR *, u_int); 47 48 static const struct xdr_ops xdrmbuf_ops = { 49 xdrmbuf_getlong, 50 xdrmbuf_putlong, 51 xdrmbuf_getbytes, 52 xdrmbuf_putbytes, 53 xdrmbuf_getpos, 54 xdrmbuf_setpos, 55 xdrmbuf_inline, 56 xdrmbuf_destroy 57 }; 58 59 /* 60 * The procedure xdrmbuf_create initializes a stream descriptor for a 61 * mbuf. 62 */ 63 void 64 xdrmbuf_create(XDR *xdrs, struct mbuf *m, enum xdr_op op) 65 { 66 67 KASSERT(m != NULL, ("xdrmbuf_create with NULL mbuf chain")); 68 xdrs->x_op = op; 69 xdrs->x_ops = &xdrmbuf_ops; 70 xdrs->x_base = (char *) m; 71 if (op == XDR_ENCODE) { 72 m = m_last(m); 73 xdrs->x_private = m; 74 xdrs->x_handy = m->m_len; 75 } else { 76 xdrs->x_private = m; 77 xdrs->x_handy = 0; 78 } 79 } 80 81 void 82 xdrmbuf_append(XDR *xdrs, struct mbuf *madd) 83 { 84 struct mbuf *m; 85 86 KASSERT(xdrs->x_ops == &xdrmbuf_ops && xdrs->x_op == XDR_ENCODE, 87 ("xdrmbuf_append: invalid XDR stream")); 88 89 if (m_length(madd, NULL) == 0) { 90 m_freem(madd); 91 return; 92 } 93 94 m = (struct mbuf *) xdrs->x_private; 95 m->m_next = madd; 96 97 m = m_last(madd); 98 xdrs->x_private = m; 99 xdrs->x_handy = m->m_len; 100 } 101 102 struct mbuf * 103 xdrmbuf_getall(XDR *xdrs) 104 { 105 struct mbuf *m0, *m; 106 107 KASSERT(xdrs->x_ops == &xdrmbuf_ops && xdrs->x_op == XDR_DECODE, 108 ("xdrmbuf_append: invalid XDR stream")); 109 110 m0 = (struct mbuf *) xdrs->x_base; 111 m = (struct mbuf *) xdrs->x_private; 112 if (m0 != m) { 113 while (m0->m_next != m) 114 m0 = m0->m_next; 115 m0->m_next = NULL; 116 xdrs->x_private = NULL; 117 } else { 118 xdrs->x_base = NULL; 119 xdrs->x_private = NULL; 120 } 121 122 if (m) 123 m_adj(m, xdrs->x_handy); 124 else 125 m = m_get(M_WAITOK, MT_DATA); 126 return (m); 127 } 128 129 static void 130 xdrmbuf_destroy(XDR *xdrs) 131 { 132 133 if (xdrs->x_op == XDR_DECODE && xdrs->x_base) { 134 m_freem((struct mbuf *) xdrs->x_base); 135 xdrs->x_base = NULL; 136 xdrs->x_private = NULL; 137 } 138 } 139 140 static bool_t 141 xdrmbuf_getlong(XDR *xdrs, long *lp) 142 { 143 int32_t *p; 144 int32_t t; 145 146 p = xdrmbuf_inline(xdrs, sizeof(int32_t)); 147 if (p) { 148 t = *p; 149 } else { 150 xdrmbuf_getbytes(xdrs, (char *) &t, sizeof(int32_t)); 151 } 152 153 *lp = ntohl(t); 154 return (TRUE); 155 } 156 157 static bool_t 158 xdrmbuf_putlong(XDR *xdrs, const long *lp) 159 { 160 int32_t *p; 161 int32_t t = htonl(*lp); 162 163 p = xdrmbuf_inline(xdrs, sizeof(int32_t)); 164 if (p) { 165 *p = t; 166 return (TRUE); 167 } else { 168 return (xdrmbuf_putbytes(xdrs, (char *) &t, sizeof(int32_t))); 169 } 170 } 171 172 static bool_t 173 xdrmbuf_getbytes(XDR *xdrs, char *addr, u_int len) 174 { 175 struct mbuf *m = (struct mbuf *) xdrs->x_private; 176 size_t sz; 177 178 while (len > 0) { 179 /* 180 * Make sure we haven't hit the end. 181 */ 182 if (!m) { 183 return (FALSE); 184 } 185 186 /* 187 * See how much we can get from this mbuf. 188 */ 189 sz = m->m_len - xdrs->x_handy; 190 if (sz > len) 191 sz = len; 192 bcopy(mtod(m, const char *) + xdrs->x_handy, addr, sz); 193 194 addr += sz; 195 xdrs->x_handy += sz; 196 len -= sz; 197 198 if (xdrs->x_handy == m->m_len) { 199 m = m->m_next; 200 xdrs->x_private = (void *) m; 201 xdrs->x_handy = 0; 202 } 203 } 204 205 return (TRUE); 206 } 207 208 static bool_t 209 xdrmbuf_putbytes(XDR *xdrs, const char *addr, u_int len) 210 { 211 struct mbuf *m = (struct mbuf *) xdrs->x_private; 212 struct mbuf *n; 213 size_t sz; 214 215 while (len > 0) { 216 sz = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 217 if (sz > len) 218 sz = len; 219 bcopy(addr, mtod(m, char *) + xdrs->x_handy, sz); 220 addr += sz; 221 xdrs->x_handy += sz; 222 if (xdrs->x_handy > m->m_len) 223 m->m_len = xdrs->x_handy; 224 len -= sz; 225 226 if (xdrs->x_handy == m->m_len && M_TRAILINGSPACE(m) == 0) { 227 if (!m->m_next) { 228 if (m->m_flags & M_EXT) 229 n = m_getcl(M_WAITOK, m->m_type, 0); 230 else 231 n = m_get(M_WAITOK, m->m_type); 232 m->m_next = n; 233 } 234 m = m->m_next; 235 xdrs->x_private = (void *) m; 236 xdrs->x_handy = 0; 237 } 238 } 239 240 return (TRUE); 241 } 242 243 static u_int 244 xdrmbuf_getpos(XDR *xdrs) 245 { 246 struct mbuf *m0 = (struct mbuf *) xdrs->x_base; 247 struct mbuf *m = (struct mbuf *) xdrs->x_private; 248 u_int pos = 0; 249 250 while (m0 && m0 != m) { 251 pos += m0->m_len; 252 m0 = m0->m_next; 253 } 254 KASSERT(m0, ("Corrupted mbuf chain")); 255 256 return (pos + xdrs->x_handy); 257 } 258 259 static bool_t 260 xdrmbuf_setpos(XDR *xdrs, u_int pos) 261 { 262 struct mbuf *m = (struct mbuf *) xdrs->x_base; 263 264 while (m && pos > m->m_len) { 265 pos -= m->m_len; 266 m = m->m_next; 267 } 268 KASSERT(m, ("Corrupted mbuf chain")); 269 270 xdrs->x_private = (void *) m; 271 xdrs->x_handy = pos; 272 273 return (TRUE); 274 } 275 276 static int32_t * 277 xdrmbuf_inline(XDR *xdrs, u_int len) 278 { 279 struct mbuf *m = (struct mbuf *) xdrs->x_private; 280 size_t available; 281 char *p; 282 283 if (!m) 284 return (0); 285 if (xdrs->x_op == XDR_ENCODE) { 286 available = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 287 } else { 288 available = m->m_len - xdrs->x_handy; 289 } 290 291 if (available >= len) { 292 p = mtod(m, char *) + xdrs->x_handy; 293 if (((uintptr_t) p) & (sizeof(int32_t) - 1)) 294 return (0); 295 xdrs->x_handy += len; 296 if (xdrs->x_handy > m->m_len) 297 m->m_len = xdrs->x_handy; 298 return ((int32_t *) p); 299 } 300 301 return (0); 302 } 303