1 /*- 2 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/ 3 * Authors: Doug Rabson <dfr@rabson.org> 4 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 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 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 MGET(m, 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(xdrs, lp) 159 XDR *xdrs; 160 const long *lp; 161 { 162 int32_t *p; 163 int32_t t = htonl(*lp); 164 165 p = xdrmbuf_inline(xdrs, sizeof(int32_t)); 166 if (p) { 167 *p = t; 168 return (TRUE); 169 } else { 170 return (xdrmbuf_putbytes(xdrs, (char *) &t, sizeof(int32_t))); 171 } 172 } 173 174 static bool_t 175 xdrmbuf_getbytes(XDR *xdrs, char *addr, u_int len) 176 { 177 struct mbuf *m = (struct mbuf *) xdrs->x_private; 178 size_t sz; 179 180 while (len > 0) { 181 /* 182 * Make sure we haven't hit the end. 183 */ 184 if (!m) { 185 return (FALSE); 186 } 187 188 /* 189 * See how much we can get from this mbuf. 190 */ 191 sz = m->m_len - xdrs->x_handy; 192 if (sz > len) 193 sz = len; 194 bcopy(mtod(m, const char *) + xdrs->x_handy, addr, sz); 195 196 addr += sz; 197 xdrs->x_handy += sz; 198 len -= sz; 199 200 if (xdrs->x_handy == m->m_len) { 201 m = m->m_next; 202 xdrs->x_private = (void *) m; 203 xdrs->x_handy = 0; 204 } 205 } 206 207 return (TRUE); 208 } 209 210 static bool_t 211 xdrmbuf_putbytes(XDR *xdrs, const char *addr, u_int len) 212 { 213 struct mbuf *m = (struct mbuf *) xdrs->x_private; 214 struct mbuf *n; 215 size_t sz; 216 217 while (len > 0) { 218 sz = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 219 if (sz > len) 220 sz = len; 221 bcopy(addr, mtod(m, char *) + xdrs->x_handy, sz); 222 addr += sz; 223 xdrs->x_handy += sz; 224 if (xdrs->x_handy > m->m_len) 225 m->m_len = xdrs->x_handy; 226 len -= sz; 227 228 if (xdrs->x_handy == m->m_len && M_TRAILINGSPACE(m) == 0) { 229 if (!m->m_next) { 230 MGET(n, M_TRYWAIT, m->m_type); 231 if (m->m_flags & M_EXT) 232 MCLGET(n, M_TRYWAIT); 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 (xdrs->x_op == XDR_ENCODE) { 285 available = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy); 286 } else { 287 available = m->m_len - xdrs->x_handy; 288 } 289 290 if (available >= len) { 291 p = mtod(m, char *) + xdrs->x_handy; 292 if (((uintptr_t) p) & (sizeof(int32_t) - 1)) 293 return (0); 294 xdrs->x_handy += len; 295 if (xdrs->x_handy > m->m_len) 296 m->m_len = xdrs->x_handy; 297 return ((int32_t *) p); 298 } 299 300 return (0); 301 } 302