| 1 | /* $NetBSD: uipc_mbuf.c,v 1.169 2016/10/04 14:13:21 christos Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, |
| 9 | * NASA Ames Research Center. |
| 10 | * |
| 11 | * Redistribution and use in source and binary forms, with or without |
| 12 | * modification, are permitted provided that the following conditions |
| 13 | * are met: |
| 14 | * 1. Redistributions of source code must retain the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer. |
| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer in the |
| 18 | * documentation and/or other materials provided with the distribution. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 22 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 23 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 24 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 26 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 27 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 28 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 29 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 30 | * POSSIBILITY OF SUCH DAMAGE. |
| 31 | */ |
| 32 | |
| 33 | /* |
| 34 | * Copyright (c) 1982, 1986, 1988, 1991, 1993 |
| 35 | * The Regents of the University of California. All rights reserved. |
| 36 | * |
| 37 | * Redistribution and use in source and binary forms, with or without |
| 38 | * modification, are permitted provided that the following conditions |
| 39 | * are met: |
| 40 | * 1. Redistributions of source code must retain the above copyright |
| 41 | * notice, this list of conditions and the following disclaimer. |
| 42 | * 2. Redistributions in binary form must reproduce the above copyright |
| 43 | * notice, this list of conditions and the following disclaimer in the |
| 44 | * documentation and/or other materials provided with the distribution. |
| 45 | * 3. Neither the name of the University nor the names of its contributors |
| 46 | * may be used to endorse or promote products derived from this software |
| 47 | * without specific prior written permission. |
| 48 | * |
| 49 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 50 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 51 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 52 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 53 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 54 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 55 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 56 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 57 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 58 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 59 | * SUCH DAMAGE. |
| 60 | * |
| 61 | * @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95 |
| 62 | */ |
| 63 | |
| 64 | #include <sys/cdefs.h> |
| 65 | __KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.169 2016/10/04 14:13:21 christos Exp $" ); |
| 66 | |
| 67 | #ifdef _KERNEL_OPT |
| 68 | #include "opt_mbuftrace.h" |
| 69 | #include "opt_nmbclusters.h" |
| 70 | #include "opt_ddb.h" |
| 71 | #endif |
| 72 | |
| 73 | #include <sys/param.h> |
| 74 | #include <sys/systm.h> |
| 75 | #include <sys/atomic.h> |
| 76 | #include <sys/cpu.h> |
| 77 | #include <sys/proc.h> |
| 78 | #include <sys/mbuf.h> |
| 79 | #include <sys/kernel.h> |
| 80 | #include <sys/syslog.h> |
| 81 | #include <sys/domain.h> |
| 82 | #include <sys/protosw.h> |
| 83 | #include <sys/percpu.h> |
| 84 | #include <sys/pool.h> |
| 85 | #include <sys/socket.h> |
| 86 | #include <sys/sysctl.h> |
| 87 | |
| 88 | #include <net/if.h> |
| 89 | |
| 90 | pool_cache_t mb_cache; /* mbuf cache */ |
| 91 | pool_cache_t mcl_cache; /* mbuf cluster cache */ |
| 92 | |
| 93 | struct mbstat mbstat; |
| 94 | int max_linkhdr; |
| 95 | int max_protohdr; |
| 96 | int max_hdr; |
| 97 | int max_datalen; |
| 98 | |
| 99 | static int mb_ctor(void *, void *, int); |
| 100 | |
| 101 | static void sysctl_kern_mbuf_setup(void); |
| 102 | |
| 103 | static struct sysctllog *mbuf_sysctllog; |
| 104 | |
| 105 | static struct mbuf *m_copym0(struct mbuf *, int, int, int, int); |
| 106 | static struct mbuf *m_split0(struct mbuf *, int, int, int); |
| 107 | static int m_copyback0(struct mbuf **, int, int, const void *, int, int); |
| 108 | |
| 109 | /* flags for m_copyback0 */ |
| 110 | #define M_COPYBACK0_COPYBACK 0x0001 /* copyback from cp */ |
| 111 | #define M_COPYBACK0_PRESERVE 0x0002 /* preserve original data */ |
| 112 | #define M_COPYBACK0_COW 0x0004 /* do copy-on-write */ |
| 113 | #define M_COPYBACK0_EXTEND 0x0008 /* extend chain */ |
| 114 | |
| 115 | static const char mclpool_warnmsg[] = |
| 116 | "WARNING: mclpool limit reached; increase kern.mbuf.nmbclusters" ; |
| 117 | |
| 118 | MALLOC_DEFINE(M_MBUF, "mbuf" , "mbuf" ); |
| 119 | |
| 120 | static percpu_t *mbstat_percpu; |
| 121 | |
| 122 | #ifdef MBUFTRACE |
| 123 | struct mownerhead mowners = LIST_HEAD_INITIALIZER(mowners); |
| 124 | struct mowner unknown_mowners[] = { |
| 125 | MOWNER_INIT("unknown" , "free" ), |
| 126 | MOWNER_INIT("unknown" , "data" ), |
| 127 | MOWNER_INIT("unknown" , "header" ), |
| 128 | MOWNER_INIT("unknown" , "soname" ), |
| 129 | MOWNER_INIT("unknown" , "soopts" ), |
| 130 | MOWNER_INIT("unknown" , "ftable" ), |
| 131 | MOWNER_INIT("unknown" , "control" ), |
| 132 | MOWNER_INIT("unknown" , "oobdata" ), |
| 133 | }; |
| 134 | struct mowner revoked_mowner = MOWNER_INIT("revoked" , "" ); |
| 135 | #endif |
| 136 | |
| 137 | #define MEXT_ISEMBEDDED(m) ((m)->m_ext_ref == (m)) |
| 138 | |
| 139 | #define MCLADDREFERENCE(o, n) \ |
| 140 | do { \ |
| 141 | KASSERT(((o)->m_flags & M_EXT) != 0); \ |
| 142 | KASSERT(((n)->m_flags & M_EXT) == 0); \ |
| 143 | KASSERT((o)->m_ext.ext_refcnt >= 1); \ |
| 144 | (n)->m_flags |= ((o)->m_flags & M_EXTCOPYFLAGS); \ |
| 145 | atomic_inc_uint(&(o)->m_ext.ext_refcnt); \ |
| 146 | (n)->m_ext_ref = (o)->m_ext_ref; \ |
| 147 | mowner_ref((n), (n)->m_flags); \ |
| 148 | MCLREFDEBUGN((n), __FILE__, __LINE__); \ |
| 149 | } while (/* CONSTCOND */ 0) |
| 150 | |
| 151 | static int |
| 152 | nmbclusters_limit(void) |
| 153 | { |
| 154 | #if defined(PMAP_MAP_POOLPAGE) |
| 155 | /* direct mapping, doesn't use space in kmem_arena */ |
| 156 | vsize_t max_size = physmem / 4; |
| 157 | #else |
| 158 | vsize_t max_size = MIN(physmem / 4, nkmempages / 4); |
| 159 | #endif |
| 160 | |
| 161 | max_size = max_size * PAGE_SIZE / MCLBYTES; |
| 162 | #ifdef NMBCLUSTERS_MAX |
| 163 | max_size = MIN(max_size, NMBCLUSTERS_MAX); |
| 164 | #endif |
| 165 | |
| 166 | #ifdef NMBCLUSTERS |
| 167 | return MIN(max_size, NMBCLUSTERS); |
| 168 | #else |
| 169 | return max_size; |
| 170 | #endif |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * Initialize the mbuf allocator. |
| 175 | */ |
| 176 | void |
| 177 | mbinit(void) |
| 178 | { |
| 179 | |
| 180 | CTASSERT(sizeof(struct _m_ext) <= MHLEN); |
| 181 | CTASSERT(sizeof(struct mbuf) == MSIZE); |
| 182 | |
| 183 | sysctl_kern_mbuf_setup(); |
| 184 | |
| 185 | mb_cache = pool_cache_init(msize, 0, 0, 0, "mbpl" , |
| 186 | NULL, IPL_VM, mb_ctor, NULL, NULL); |
| 187 | KASSERT(mb_cache != NULL); |
| 188 | |
| 189 | mcl_cache = pool_cache_init(mclbytes, 0, 0, 0, "mclpl" , NULL, |
| 190 | IPL_VM, NULL, NULL, NULL); |
| 191 | KASSERT(mcl_cache != NULL); |
| 192 | |
| 193 | pool_cache_set_drain_hook(mb_cache, m_reclaim, NULL); |
| 194 | pool_cache_set_drain_hook(mcl_cache, m_reclaim, NULL); |
| 195 | |
| 196 | /* |
| 197 | * Set an arbitrary default limit on the number of mbuf clusters. |
| 198 | */ |
| 199 | #ifdef NMBCLUSTERS |
| 200 | nmbclusters = nmbclusters_limit(); |
| 201 | #else |
| 202 | nmbclusters = MAX(1024, |
| 203 | (vsize_t)physmem * PAGE_SIZE / MCLBYTES / 16); |
| 204 | nmbclusters = MIN(nmbclusters, nmbclusters_limit()); |
| 205 | #endif |
| 206 | |
| 207 | /* |
| 208 | * Set the hard limit on the mclpool to the number of |
| 209 | * mbuf clusters the kernel is to support. Log the limit |
| 210 | * reached message max once a minute. |
| 211 | */ |
| 212 | pool_cache_sethardlimit(mcl_cache, nmbclusters, mclpool_warnmsg, 60); |
| 213 | |
| 214 | mbstat_percpu = percpu_alloc(sizeof(struct mbstat_cpu)); |
| 215 | |
| 216 | /* |
| 217 | * Set a low water mark for both mbufs and clusters. This should |
| 218 | * help ensure that they can be allocated in a memory starvation |
| 219 | * situation. This is important for e.g. diskless systems which |
| 220 | * must allocate mbufs in order for the pagedaemon to clean pages. |
| 221 | */ |
| 222 | pool_cache_setlowat(mb_cache, mblowat); |
| 223 | pool_cache_setlowat(mcl_cache, mcllowat); |
| 224 | |
| 225 | #ifdef MBUFTRACE |
| 226 | { |
| 227 | /* |
| 228 | * Attach the unknown mowners. |
| 229 | */ |
| 230 | int i; |
| 231 | MOWNER_ATTACH(&revoked_mowner); |
| 232 | for (i = sizeof(unknown_mowners)/sizeof(unknown_mowners[0]); |
| 233 | i-- > 0; ) |
| 234 | MOWNER_ATTACH(&unknown_mowners[i]); |
| 235 | } |
| 236 | #endif |
| 237 | } |
| 238 | |
| 239 | /* |
| 240 | * sysctl helper routine for the kern.mbuf subtree. |
| 241 | * nmbclusters, mblowat and mcllowat need range |
| 242 | * checking and pool tweaking after being reset. |
| 243 | */ |
| 244 | static int |
| 245 | sysctl_kern_mbuf(SYSCTLFN_ARGS) |
| 246 | { |
| 247 | int error, newval; |
| 248 | struct sysctlnode node; |
| 249 | |
| 250 | node = *rnode; |
| 251 | node.sysctl_data = &newval; |
| 252 | switch (rnode->sysctl_num) { |
| 253 | case MBUF_NMBCLUSTERS: |
| 254 | case MBUF_MBLOWAT: |
| 255 | case MBUF_MCLLOWAT: |
| 256 | newval = *(int*)rnode->sysctl_data; |
| 257 | break; |
| 258 | default: |
| 259 | return (EOPNOTSUPP); |
| 260 | } |
| 261 | |
| 262 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 263 | if (error || newp == NULL) |
| 264 | return (error); |
| 265 | if (newval < 0) |
| 266 | return (EINVAL); |
| 267 | |
| 268 | switch (node.sysctl_num) { |
| 269 | case MBUF_NMBCLUSTERS: |
| 270 | if (newval < nmbclusters) |
| 271 | return (EINVAL); |
| 272 | if (newval > nmbclusters_limit()) |
| 273 | return (EINVAL); |
| 274 | nmbclusters = newval; |
| 275 | pool_cache_sethardlimit(mcl_cache, nmbclusters, |
| 276 | mclpool_warnmsg, 60); |
| 277 | break; |
| 278 | case MBUF_MBLOWAT: |
| 279 | mblowat = newval; |
| 280 | pool_cache_setlowat(mb_cache, mblowat); |
| 281 | break; |
| 282 | case MBUF_MCLLOWAT: |
| 283 | mcllowat = newval; |
| 284 | pool_cache_setlowat(mcl_cache, mcllowat); |
| 285 | break; |
| 286 | } |
| 287 | |
| 288 | return (0); |
| 289 | } |
| 290 | |
| 291 | #ifdef MBUFTRACE |
| 292 | static void |
| 293 | mowner_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) |
| 294 | { |
| 295 | struct mowner_counter *mc = v1; |
| 296 | struct mowner_user *mo_user = v2; |
| 297 | int i; |
| 298 | |
| 299 | for (i = 0; i < MOWNER_COUNTER_NCOUNTERS; i++) { |
| 300 | mo_user->mo_counter[i] += mc->mc_counter[i]; |
| 301 | } |
| 302 | } |
| 303 | |
| 304 | static void |
| 305 | mowner_convert_to_user(struct mowner *mo, struct mowner_user *mo_user) |
| 306 | { |
| 307 | |
| 308 | memset(mo_user, 0, sizeof(*mo_user)); |
| 309 | CTASSERT(sizeof(mo_user->mo_name) == sizeof(mo->mo_name)); |
| 310 | CTASSERT(sizeof(mo_user->mo_descr) == sizeof(mo->mo_descr)); |
| 311 | memcpy(mo_user->mo_name, mo->mo_name, sizeof(mo->mo_name)); |
| 312 | memcpy(mo_user->mo_descr, mo->mo_descr, sizeof(mo->mo_descr)); |
| 313 | percpu_foreach(mo->mo_counters, mowner_conver_to_user_cb, mo_user); |
| 314 | } |
| 315 | |
| 316 | static int |
| 317 | sysctl_kern_mbuf_mowners(SYSCTLFN_ARGS) |
| 318 | { |
| 319 | struct mowner *mo; |
| 320 | size_t len = 0; |
| 321 | int error = 0; |
| 322 | |
| 323 | if (namelen != 0) |
| 324 | return (EINVAL); |
| 325 | if (newp != NULL) |
| 326 | return (EPERM); |
| 327 | |
| 328 | LIST_FOREACH(mo, &mowners, mo_link) { |
| 329 | struct mowner_user mo_user; |
| 330 | |
| 331 | mowner_convert_to_user(mo, &mo_user); |
| 332 | |
| 333 | if (oldp != NULL) { |
| 334 | if (*oldlenp - len < sizeof(mo_user)) { |
| 335 | error = ENOMEM; |
| 336 | break; |
| 337 | } |
| 338 | error = copyout(&mo_user, (char *)oldp + len, |
| 339 | sizeof(mo_user)); |
| 340 | if (error) |
| 341 | break; |
| 342 | } |
| 343 | len += sizeof(mo_user); |
| 344 | } |
| 345 | |
| 346 | if (error == 0) |
| 347 | *oldlenp = len; |
| 348 | |
| 349 | return (error); |
| 350 | } |
| 351 | #endif /* MBUFTRACE */ |
| 352 | |
| 353 | static void |
| 354 | mbstat_conver_to_user_cb(void *v1, void *v2, struct cpu_info *ci) |
| 355 | { |
| 356 | struct mbstat_cpu *mbsc = v1; |
| 357 | struct mbstat *mbs = v2; |
| 358 | int i; |
| 359 | |
| 360 | for (i = 0; i < __arraycount(mbs->m_mtypes); i++) { |
| 361 | mbs->m_mtypes[i] += mbsc->m_mtypes[i]; |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | static void |
| 366 | mbstat_convert_to_user(struct mbstat *mbs) |
| 367 | { |
| 368 | |
| 369 | memset(mbs, 0, sizeof(*mbs)); |
| 370 | mbs->m_drain = mbstat.m_drain; |
| 371 | percpu_foreach(mbstat_percpu, mbstat_conver_to_user_cb, mbs); |
| 372 | } |
| 373 | |
| 374 | static int |
| 375 | sysctl_kern_mbuf_stats(SYSCTLFN_ARGS) |
| 376 | { |
| 377 | struct sysctlnode node; |
| 378 | struct mbstat mbs; |
| 379 | |
| 380 | mbstat_convert_to_user(&mbs); |
| 381 | node = *rnode; |
| 382 | node.sysctl_data = &mbs; |
| 383 | node.sysctl_size = sizeof(mbs); |
| 384 | return sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 385 | } |
| 386 | |
| 387 | static void |
| 388 | sysctl_kern_mbuf_setup(void) |
| 389 | { |
| 390 | |
| 391 | KASSERT(mbuf_sysctllog == NULL); |
| 392 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 393 | CTLFLAG_PERMANENT, |
| 394 | CTLTYPE_NODE, "mbuf" , |
| 395 | SYSCTL_DESCR("mbuf control variables" ), |
| 396 | NULL, 0, NULL, 0, |
| 397 | CTL_KERN, KERN_MBUF, CTL_EOL); |
| 398 | |
| 399 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 400 | CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, |
| 401 | CTLTYPE_INT, "msize" , |
| 402 | SYSCTL_DESCR("mbuf base size" ), |
| 403 | NULL, msize, NULL, 0, |
| 404 | CTL_KERN, KERN_MBUF, MBUF_MSIZE, CTL_EOL); |
| 405 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 406 | CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, |
| 407 | CTLTYPE_INT, "mclbytes" , |
| 408 | SYSCTL_DESCR("mbuf cluster size" ), |
| 409 | NULL, mclbytes, NULL, 0, |
| 410 | CTL_KERN, KERN_MBUF, MBUF_MCLBYTES, CTL_EOL); |
| 411 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 412 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 413 | CTLTYPE_INT, "nmbclusters" , |
| 414 | SYSCTL_DESCR("Limit on the number of mbuf clusters" ), |
| 415 | sysctl_kern_mbuf, 0, &nmbclusters, 0, |
| 416 | CTL_KERN, KERN_MBUF, MBUF_NMBCLUSTERS, CTL_EOL); |
| 417 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 418 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 419 | CTLTYPE_INT, "mblowat" , |
| 420 | SYSCTL_DESCR("mbuf low water mark" ), |
| 421 | sysctl_kern_mbuf, 0, &mblowat, 0, |
| 422 | CTL_KERN, KERN_MBUF, MBUF_MBLOWAT, CTL_EOL); |
| 423 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 424 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 425 | CTLTYPE_INT, "mcllowat" , |
| 426 | SYSCTL_DESCR("mbuf cluster low water mark" ), |
| 427 | sysctl_kern_mbuf, 0, &mcllowat, 0, |
| 428 | CTL_KERN, KERN_MBUF, MBUF_MCLLOWAT, CTL_EOL); |
| 429 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 430 | CTLFLAG_PERMANENT, |
| 431 | CTLTYPE_STRUCT, "stats" , |
| 432 | SYSCTL_DESCR("mbuf allocation statistics" ), |
| 433 | sysctl_kern_mbuf_stats, 0, NULL, 0, |
| 434 | CTL_KERN, KERN_MBUF, MBUF_STATS, CTL_EOL); |
| 435 | #ifdef MBUFTRACE |
| 436 | sysctl_createv(&mbuf_sysctllog, 0, NULL, NULL, |
| 437 | CTLFLAG_PERMANENT, |
| 438 | CTLTYPE_STRUCT, "mowners" , |
| 439 | SYSCTL_DESCR("Information about mbuf owners" ), |
| 440 | sysctl_kern_mbuf_mowners, 0, NULL, 0, |
| 441 | CTL_KERN, KERN_MBUF, MBUF_MOWNERS, CTL_EOL); |
| 442 | #endif /* MBUFTRACE */ |
| 443 | } |
| 444 | |
| 445 | static int |
| 446 | mb_ctor(void *arg, void *object, int flags) |
| 447 | { |
| 448 | struct mbuf *m = object; |
| 449 | |
| 450 | #ifdef POOL_VTOPHYS |
| 451 | m->m_paddr = POOL_VTOPHYS(m); |
| 452 | #else |
| 453 | m->m_paddr = M_PADDR_INVALID; |
| 454 | #endif |
| 455 | return (0); |
| 456 | } |
| 457 | |
| 458 | /* |
| 459 | * Add mbuf to the end of a chain |
| 460 | */ |
| 461 | struct mbuf * |
| 462 | m_add(struct mbuf *c, struct mbuf *m) { |
| 463 | struct mbuf *n; |
| 464 | |
| 465 | if (c == NULL) |
| 466 | return m; |
| 467 | |
| 468 | for (n = c; n->m_next != NULL; n = n->m_next) |
| 469 | continue; |
| 470 | n->m_next = m; |
| 471 | return c; |
| 472 | } |
| 473 | |
| 474 | /* |
| 475 | * Set the m_data pointer of a newly-allocated mbuf |
| 476 | * to place an object of the specified size at the |
| 477 | * end of the mbuf, longword aligned. |
| 478 | */ |
| 479 | void |
| 480 | m_align(struct mbuf *m, int len) |
| 481 | { |
| 482 | int adjust; |
| 483 | |
| 484 | KASSERT(len != M_COPYALL); |
| 485 | |
| 486 | if (m->m_flags & M_EXT) |
| 487 | adjust = m->m_ext.ext_size - len; |
| 488 | else if (m->m_flags & M_PKTHDR) |
| 489 | adjust = MHLEN - len; |
| 490 | else |
| 491 | adjust = MLEN - len; |
| 492 | m->m_data += adjust &~ (sizeof(long)-1); |
| 493 | } |
| 494 | |
| 495 | /* |
| 496 | * Append the specified data to the indicated mbuf chain, |
| 497 | * Extend the mbuf chain if the new data does not fit in |
| 498 | * existing space. |
| 499 | * |
| 500 | * Return 1 if able to complete the job; otherwise 0. |
| 501 | */ |
| 502 | int |
| 503 | m_append(struct mbuf *m0, int len, const void *cpv) |
| 504 | { |
| 505 | struct mbuf *m, *n; |
| 506 | int remainder, space; |
| 507 | const char *cp = cpv; |
| 508 | |
| 509 | KASSERT(len != M_COPYALL); |
| 510 | for (m = m0; m->m_next != NULL; m = m->m_next) |
| 511 | continue; |
| 512 | remainder = len; |
| 513 | space = M_TRAILINGSPACE(m); |
| 514 | if (space > 0) { |
| 515 | /* |
| 516 | * Copy into available space. |
| 517 | */ |
| 518 | if (space > remainder) |
| 519 | space = remainder; |
| 520 | memmove(mtod(m, char *) + m->m_len, cp, space); |
| 521 | m->m_len += space; |
| 522 | cp = cp + space, remainder -= space; |
| 523 | } |
| 524 | while (remainder > 0) { |
| 525 | /* |
| 526 | * Allocate a new mbuf; could check space |
| 527 | * and allocate a cluster instead. |
| 528 | */ |
| 529 | n = m_get(M_DONTWAIT, m->m_type); |
| 530 | if (n == NULL) |
| 531 | break; |
| 532 | n->m_len = min(MLEN, remainder); |
| 533 | memmove(mtod(n, void *), cp, n->m_len); |
| 534 | cp += n->m_len, remainder -= n->m_len; |
| 535 | m->m_next = n; |
| 536 | m = n; |
| 537 | } |
| 538 | if (m0->m_flags & M_PKTHDR) |
| 539 | m0->m_pkthdr.len += len - remainder; |
| 540 | return (remainder == 0); |
| 541 | } |
| 542 | |
| 543 | void |
| 544 | m_reclaim(void *arg, int flags) |
| 545 | { |
| 546 | struct domain *dp; |
| 547 | const struct protosw *pr; |
| 548 | struct ifnet *ifp; |
| 549 | int s; |
| 550 | |
| 551 | KERNEL_LOCK(1, NULL); |
| 552 | s = splvm(); |
| 553 | DOMAIN_FOREACH(dp) { |
| 554 | for (pr = dp->dom_protosw; |
| 555 | pr < dp->dom_protoswNPROTOSW; pr++) |
| 556 | if (pr->pr_drain) |
| 557 | (*pr->pr_drain)(); |
| 558 | } |
| 559 | /* XXX we cannot use psref in H/W interrupt */ |
| 560 | if (!cpu_intr_p()) { |
| 561 | int bound = curlwp_bind(); |
| 562 | IFNET_READER_FOREACH(ifp) { |
| 563 | struct psref psref; |
| 564 | |
| 565 | psref_acquire(&psref, &ifp->if_psref, |
| 566 | ifnet_psref_class); |
| 567 | |
| 568 | if (ifp->if_drain) |
| 569 | (*ifp->if_drain)(ifp); |
| 570 | |
| 571 | psref_release(&psref, &ifp->if_psref, |
| 572 | ifnet_psref_class); |
| 573 | } |
| 574 | curlwp_bindx(bound); |
| 575 | } |
| 576 | splx(s); |
| 577 | mbstat.m_drain++; |
| 578 | KERNEL_UNLOCK_ONE(NULL); |
| 579 | } |
| 580 | |
| 581 | /* |
| 582 | * Space allocation routines. |
| 583 | * These are also available as macros |
| 584 | * for critical paths. |
| 585 | */ |
| 586 | struct mbuf * |
| 587 | m_get(int nowait, int type) |
| 588 | { |
| 589 | struct mbuf *m; |
| 590 | |
| 591 | KASSERT(type != MT_FREE); |
| 592 | |
| 593 | m = pool_cache_get(mb_cache, |
| 594 | nowait == M_WAIT ? PR_WAITOK|PR_LIMITFAIL : 0); |
| 595 | if (m == NULL) |
| 596 | return NULL; |
| 597 | |
| 598 | mbstat_type_add(type, 1); |
| 599 | |
| 600 | m_hdr_init(m, type, NULL, m->m_dat, 0); |
| 601 | |
| 602 | return m; |
| 603 | } |
| 604 | |
| 605 | struct mbuf * |
| 606 | m_gethdr(int nowait, int type) |
| 607 | { |
| 608 | struct mbuf *m; |
| 609 | |
| 610 | m = m_get(nowait, type); |
| 611 | if (m == NULL) |
| 612 | return NULL; |
| 613 | |
| 614 | m_pkthdr_init(m); |
| 615 | |
| 616 | return m; |
| 617 | } |
| 618 | |
| 619 | struct mbuf * |
| 620 | m_getclr(int nowait, int type) |
| 621 | { |
| 622 | struct mbuf *m; |
| 623 | |
| 624 | m = m_get(nowait, type); |
| 625 | if (m == 0) |
| 626 | return (NULL); |
| 627 | memset(mtod(m, void *), 0, MLEN); |
| 628 | return (m); |
| 629 | } |
| 630 | |
| 631 | void |
| 632 | m_clget(struct mbuf *m, int nowait) |
| 633 | { |
| 634 | |
| 635 | MCLGET(m, nowait); |
| 636 | } |
| 637 | |
| 638 | #ifdef MBUFTRACE |
| 639 | /* |
| 640 | * Walk a chain of mbufs, claiming ownership of each mbuf in the chain. |
| 641 | */ |
| 642 | void |
| 643 | m_claimm(struct mbuf *m, struct mowner *mo) |
| 644 | { |
| 645 | |
| 646 | for (; m != NULL; m = m->m_next) |
| 647 | MCLAIM(m, mo); |
| 648 | } |
| 649 | #endif |
| 650 | |
| 651 | /* |
| 652 | * Mbuffer utility routines. |
| 653 | */ |
| 654 | |
| 655 | /* |
| 656 | * Lesser-used path for M_PREPEND: |
| 657 | * allocate new mbuf to prepend to chain, |
| 658 | * copy junk along. |
| 659 | */ |
| 660 | struct mbuf * |
| 661 | m_prepend(struct mbuf *m, int len, int how) |
| 662 | { |
| 663 | struct mbuf *mn; |
| 664 | |
| 665 | KASSERT(len != M_COPYALL); |
| 666 | mn = m_get(how, m->m_type); |
| 667 | if (mn == NULL) { |
| 668 | m_freem(m); |
| 669 | return (NULL); |
| 670 | } |
| 671 | if (m->m_flags & M_PKTHDR) { |
| 672 | M_MOVE_PKTHDR(mn, m); |
| 673 | } else { |
| 674 | MCLAIM(mn, m->m_owner); |
| 675 | } |
| 676 | mn->m_next = m; |
| 677 | m = mn; |
| 678 | if (len < MHLEN) |
| 679 | MH_ALIGN(m, len); |
| 680 | m->m_len = len; |
| 681 | return (m); |
| 682 | } |
| 683 | |
| 684 | /* |
| 685 | * Make a copy of an mbuf chain starting "off0" bytes from the beginning, |
| 686 | * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. |
| 687 | * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. |
| 688 | */ |
| 689 | int MCFail; |
| 690 | |
| 691 | struct mbuf * |
| 692 | m_copym(struct mbuf *m, int off0, int len, int wait) |
| 693 | { |
| 694 | |
| 695 | return m_copym0(m, off0, len, wait, 0); /* shallow copy on M_EXT */ |
| 696 | } |
| 697 | |
| 698 | struct mbuf * |
| 699 | m_dup(struct mbuf *m, int off0, int len, int wait) |
| 700 | { |
| 701 | |
| 702 | return m_copym0(m, off0, len, wait, 1); /* deep copy */ |
| 703 | } |
| 704 | |
| 705 | static inline int |
| 706 | m_copylen(int len, int copylen) { |
| 707 | return len == M_COPYALL ? copylen : min(len, copylen); |
| 708 | } |
| 709 | |
| 710 | static struct mbuf * |
| 711 | m_copym0(struct mbuf *m, int off0, int len, int wait, int deep) |
| 712 | { |
| 713 | struct mbuf *n, **np; |
| 714 | int off = off0; |
| 715 | struct mbuf *top; |
| 716 | int copyhdr = 0; |
| 717 | |
| 718 | if (off < 0 || (len != M_COPYALL && len < 0)) |
| 719 | panic("m_copym: off %d, len %d" , off, len); |
| 720 | if (off == 0 && m->m_flags & M_PKTHDR) |
| 721 | copyhdr = 1; |
| 722 | while (off > 0) { |
| 723 | if (m == 0) |
| 724 | panic("m_copym: m == 0, off %d" , off); |
| 725 | if (off < m->m_len) |
| 726 | break; |
| 727 | off -= m->m_len; |
| 728 | m = m->m_next; |
| 729 | } |
| 730 | np = ⊤ |
| 731 | top = 0; |
| 732 | while (len == M_COPYALL || len > 0) { |
| 733 | if (m == 0) { |
| 734 | if (len != M_COPYALL) |
| 735 | panic("m_copym: m == 0, len %d [!COPYALL]" , |
| 736 | len); |
| 737 | break; |
| 738 | } |
| 739 | n = m_get(wait, m->m_type); |
| 740 | *np = n; |
| 741 | if (n == 0) |
| 742 | goto nospace; |
| 743 | MCLAIM(n, m->m_owner); |
| 744 | if (copyhdr) { |
| 745 | M_COPY_PKTHDR(n, m); |
| 746 | if (len == M_COPYALL) |
| 747 | n->m_pkthdr.len -= off0; |
| 748 | else |
| 749 | n->m_pkthdr.len = len; |
| 750 | copyhdr = 0; |
| 751 | } |
| 752 | n->m_len = m_copylen(len, m->m_len - off); |
| 753 | if (m->m_flags & M_EXT) { |
| 754 | if (!deep) { |
| 755 | n->m_data = m->m_data + off; |
| 756 | MCLADDREFERENCE(m, n); |
| 757 | } else { |
| 758 | /* |
| 759 | * we are unsure about the way m was allocated. |
| 760 | * copy into multiple MCLBYTES cluster mbufs. |
| 761 | * |
| 762 | * recompute m_len, it is no longer valid if MCLGET() |
| 763 | * fails to allocate a cluster. Then we try to split |
| 764 | * the source into normal sized mbufs. |
| 765 | */ |
| 766 | MCLGET(n, wait); |
| 767 | n->m_len = 0; |
| 768 | n->m_len = M_TRAILINGSPACE(n); |
| 769 | n->m_len = m_copylen(len, n->m_len); |
| 770 | n->m_len = min(n->m_len, m->m_len - off); |
| 771 | memcpy(mtod(n, void *), mtod(m, char *) + off, |
| 772 | (unsigned)n->m_len); |
| 773 | } |
| 774 | } else |
| 775 | memcpy(mtod(n, void *), mtod(m, char *) + off, |
| 776 | (unsigned)n->m_len); |
| 777 | if (len != M_COPYALL) |
| 778 | len -= n->m_len; |
| 779 | off += n->m_len; |
| 780 | #ifdef DIAGNOSTIC |
| 781 | if (off > m->m_len) |
| 782 | panic("m_copym0 overrun %d %d" , off, m->m_len); |
| 783 | #endif |
| 784 | if (off == m->m_len) { |
| 785 | m = m->m_next; |
| 786 | off = 0; |
| 787 | } |
| 788 | np = &n->m_next; |
| 789 | } |
| 790 | if (top == 0) |
| 791 | MCFail++; |
| 792 | return (top); |
| 793 | nospace: |
| 794 | m_freem(top); |
| 795 | MCFail++; |
| 796 | return (NULL); |
| 797 | } |
| 798 | |
| 799 | /* |
| 800 | * Copy an entire packet, including header (which must be present). |
| 801 | * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. |
| 802 | */ |
| 803 | struct mbuf * |
| 804 | m_copypacket(struct mbuf *m, int how) |
| 805 | { |
| 806 | struct mbuf *top, *n, *o; |
| 807 | |
| 808 | n = m_get(how, m->m_type); |
| 809 | top = n; |
| 810 | if (!n) |
| 811 | goto nospace; |
| 812 | |
| 813 | MCLAIM(n, m->m_owner); |
| 814 | M_COPY_PKTHDR(n, m); |
| 815 | n->m_len = m->m_len; |
| 816 | if (m->m_flags & M_EXT) { |
| 817 | n->m_data = m->m_data; |
| 818 | MCLADDREFERENCE(m, n); |
| 819 | } else { |
| 820 | memcpy(mtod(n, char *), mtod(m, char *), n->m_len); |
| 821 | } |
| 822 | |
| 823 | m = m->m_next; |
| 824 | while (m) { |
| 825 | o = m_get(how, m->m_type); |
| 826 | if (!o) |
| 827 | goto nospace; |
| 828 | |
| 829 | MCLAIM(o, m->m_owner); |
| 830 | n->m_next = o; |
| 831 | n = n->m_next; |
| 832 | |
| 833 | n->m_len = m->m_len; |
| 834 | if (m->m_flags & M_EXT) { |
| 835 | n->m_data = m->m_data; |
| 836 | MCLADDREFERENCE(m, n); |
| 837 | } else { |
| 838 | memcpy(mtod(n, char *), mtod(m, char *), n->m_len); |
| 839 | } |
| 840 | |
| 841 | m = m->m_next; |
| 842 | } |
| 843 | return top; |
| 844 | nospace: |
| 845 | m_freem(top); |
| 846 | MCFail++; |
| 847 | return NULL; |
| 848 | } |
| 849 | |
| 850 | /* |
| 851 | * Copy data from an mbuf chain starting "off" bytes from the beginning, |
| 852 | * continuing for "len" bytes, into the indicated buffer. |
| 853 | */ |
| 854 | void |
| 855 | m_copydata(struct mbuf *m, int off, int len, void *vp) |
| 856 | { |
| 857 | unsigned count; |
| 858 | void * cp = vp; |
| 859 | struct mbuf *m0 = m; |
| 860 | int len0 = len; |
| 861 | int off0 = off; |
| 862 | void *vp0 = vp; |
| 863 | |
| 864 | KASSERT(len != M_COPYALL); |
| 865 | if (off < 0 || len < 0) |
| 866 | panic("m_copydata: off %d, len %d" , off, len); |
| 867 | while (off > 0) { |
| 868 | if (m == NULL) |
| 869 | panic("m_copydata(%p,%d,%d,%p): m=NULL, off=%d (%d)" , |
| 870 | m0, len0, off0, vp0, off, off0 - off); |
| 871 | if (off < m->m_len) |
| 872 | break; |
| 873 | off -= m->m_len; |
| 874 | m = m->m_next; |
| 875 | } |
| 876 | while (len > 0) { |
| 877 | if (m == NULL) |
| 878 | panic("m_copydata(%p,%d,%d,%p): " |
| 879 | "m=NULL, off=%d (%d), len=%d (%d)" , |
| 880 | m0, len0, off0, vp0, |
| 881 | off, off0 - off, len, len0 - len); |
| 882 | count = min(m->m_len - off, len); |
| 883 | memcpy(cp, mtod(m, char *) + off, count); |
| 884 | len -= count; |
| 885 | cp = (char *)cp + count; |
| 886 | off = 0; |
| 887 | m = m->m_next; |
| 888 | } |
| 889 | } |
| 890 | |
| 891 | /* |
| 892 | * Concatenate mbuf chain n to m. |
| 893 | * n might be copied into m (when n->m_len is small), therefore data portion of |
| 894 | * n could be copied into an mbuf of different mbuf type. |
| 895 | * Any m_pkthdr is not updated. |
| 896 | */ |
| 897 | void |
| 898 | m_cat(struct mbuf *m, struct mbuf *n) |
| 899 | { |
| 900 | |
| 901 | while (m->m_next) |
| 902 | m = m->m_next; |
| 903 | while (n) { |
| 904 | if (M_READONLY(m) || n->m_len > M_TRAILINGSPACE(m)) { |
| 905 | /* just join the two chains */ |
| 906 | m->m_next = n; |
| 907 | return; |
| 908 | } |
| 909 | /* splat the data from one into the other */ |
| 910 | memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), |
| 911 | (u_int)n->m_len); |
| 912 | m->m_len += n->m_len; |
| 913 | n = m_free(n); |
| 914 | } |
| 915 | } |
| 916 | |
| 917 | void |
| 918 | m_adj(struct mbuf *mp, int req_len) |
| 919 | { |
| 920 | int len = req_len; |
| 921 | struct mbuf *m; |
| 922 | int count; |
| 923 | |
| 924 | if ((m = mp) == NULL) |
| 925 | return; |
| 926 | if (len >= 0) { |
| 927 | /* |
| 928 | * Trim from head. |
| 929 | */ |
| 930 | while (m != NULL && len > 0) { |
| 931 | if (m->m_len <= len) { |
| 932 | len -= m->m_len; |
| 933 | m->m_len = 0; |
| 934 | m = m->m_next; |
| 935 | } else { |
| 936 | m->m_len -= len; |
| 937 | m->m_data += len; |
| 938 | len = 0; |
| 939 | } |
| 940 | } |
| 941 | m = mp; |
| 942 | if (mp->m_flags & M_PKTHDR) |
| 943 | m->m_pkthdr.len -= (req_len - len); |
| 944 | } else { |
| 945 | /* |
| 946 | * Trim from tail. Scan the mbuf chain, |
| 947 | * calculating its length and finding the last mbuf. |
| 948 | * If the adjustment only affects this mbuf, then just |
| 949 | * adjust and return. Otherwise, rescan and truncate |
| 950 | * after the remaining size. |
| 951 | */ |
| 952 | len = -len; |
| 953 | count = 0; |
| 954 | for (;;) { |
| 955 | count += m->m_len; |
| 956 | if (m->m_next == (struct mbuf *)0) |
| 957 | break; |
| 958 | m = m->m_next; |
| 959 | } |
| 960 | if (m->m_len >= len) { |
| 961 | m->m_len -= len; |
| 962 | if (mp->m_flags & M_PKTHDR) |
| 963 | mp->m_pkthdr.len -= len; |
| 964 | return; |
| 965 | } |
| 966 | count -= len; |
| 967 | if (count < 0) |
| 968 | count = 0; |
| 969 | /* |
| 970 | * Correct length for chain is "count". |
| 971 | * Find the mbuf with last data, adjust its length, |
| 972 | * and toss data from remaining mbufs on chain. |
| 973 | */ |
| 974 | m = mp; |
| 975 | if (m->m_flags & M_PKTHDR) |
| 976 | m->m_pkthdr.len = count; |
| 977 | for (; m; m = m->m_next) { |
| 978 | if (m->m_len >= count) { |
| 979 | m->m_len = count; |
| 980 | break; |
| 981 | } |
| 982 | count -= m->m_len; |
| 983 | } |
| 984 | if (m) |
| 985 | while (m->m_next) |
| 986 | (m = m->m_next)->m_len = 0; |
| 987 | } |
| 988 | } |
| 989 | |
| 990 | /* |
| 991 | * m_ensure_contig: rearrange an mbuf chain that given length of bytes |
| 992 | * would be contiguous and in the data area of an mbuf (therefore, mtod() |
| 993 | * would work for a structure of given length). |
| 994 | * |
| 995 | * => On success, returns true and the resulting mbuf chain; false otherwise. |
| 996 | * => The mbuf chain may change, but is always preserved valid. |
| 997 | */ |
| 998 | bool |
| 999 | m_ensure_contig(struct mbuf **m0, int len) |
| 1000 | { |
| 1001 | struct mbuf *n = *m0, *m; |
| 1002 | size_t count, space; |
| 1003 | |
| 1004 | KASSERT(len != M_COPYALL); |
| 1005 | /* |
| 1006 | * If first mbuf has no cluster, and has room for len bytes |
| 1007 | * without shifting current data, pullup into it, |
| 1008 | * otherwise allocate a new mbuf to prepend to the chain. |
| 1009 | */ |
| 1010 | if ((n->m_flags & M_EXT) == 0 && |
| 1011 | n->m_data + len < &n->m_dat[MLEN] && n->m_next) { |
| 1012 | if (n->m_len >= len) { |
| 1013 | return true; |
| 1014 | } |
| 1015 | m = n; |
| 1016 | n = n->m_next; |
| 1017 | len -= m->m_len; |
| 1018 | } else { |
| 1019 | if (len > MHLEN) { |
| 1020 | return false; |
| 1021 | } |
| 1022 | m = m_get(M_DONTWAIT, n->m_type); |
| 1023 | if (m == NULL) { |
| 1024 | return false; |
| 1025 | } |
| 1026 | MCLAIM(m, n->m_owner); |
| 1027 | if (n->m_flags & M_PKTHDR) { |
| 1028 | M_MOVE_PKTHDR(m, n); |
| 1029 | } |
| 1030 | } |
| 1031 | space = &m->m_dat[MLEN] - (m->m_data + m->m_len); |
| 1032 | do { |
| 1033 | count = MIN(MIN(MAX(len, max_protohdr), space), n->m_len); |
| 1034 | memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), |
| 1035 | (unsigned)count); |
| 1036 | len -= count; |
| 1037 | m->m_len += count; |
| 1038 | n->m_len -= count; |
| 1039 | space -= count; |
| 1040 | if (n->m_len) |
| 1041 | n->m_data += count; |
| 1042 | else |
| 1043 | n = m_free(n); |
| 1044 | } while (len > 0 && n); |
| 1045 | |
| 1046 | m->m_next = n; |
| 1047 | *m0 = m; |
| 1048 | |
| 1049 | return len <= 0; |
| 1050 | } |
| 1051 | |
| 1052 | /* |
| 1053 | * m_pullup: same as m_ensure_contig(), but destroys mbuf chain on error. |
| 1054 | */ |
| 1055 | int MPFail; |
| 1056 | |
| 1057 | struct mbuf * |
| 1058 | m_pullup(struct mbuf *n, int len) |
| 1059 | { |
| 1060 | struct mbuf *m = n; |
| 1061 | |
| 1062 | KASSERT(len != M_COPYALL); |
| 1063 | if (!m_ensure_contig(&m, len)) { |
| 1064 | KASSERT(m != NULL); |
| 1065 | m_freem(m); |
| 1066 | MPFail++; |
| 1067 | m = NULL; |
| 1068 | } |
| 1069 | return m; |
| 1070 | } |
| 1071 | |
| 1072 | /* |
| 1073 | * Like m_pullup(), except a new mbuf is always allocated, and we allow |
| 1074 | * the amount of empty space before the data in the new mbuf to be specified |
| 1075 | * (in the event that the caller expects to prepend later). |
| 1076 | */ |
| 1077 | int MSFail; |
| 1078 | |
| 1079 | struct mbuf * |
| 1080 | m_copyup(struct mbuf *n, int len, int dstoff) |
| 1081 | { |
| 1082 | struct mbuf *m; |
| 1083 | int count, space; |
| 1084 | |
| 1085 | KASSERT(len != M_COPYALL); |
| 1086 | if (len > (MHLEN - dstoff)) |
| 1087 | goto bad; |
| 1088 | m = m_get(M_DONTWAIT, n->m_type); |
| 1089 | if (m == NULL) |
| 1090 | goto bad; |
| 1091 | MCLAIM(m, n->m_owner); |
| 1092 | if (n->m_flags & M_PKTHDR) { |
| 1093 | M_MOVE_PKTHDR(m, n); |
| 1094 | } |
| 1095 | m->m_data += dstoff; |
| 1096 | space = &m->m_dat[MLEN] - (m->m_data + m->m_len); |
| 1097 | do { |
| 1098 | count = min(min(max(len, max_protohdr), space), n->m_len); |
| 1099 | memcpy(mtod(m, char *) + m->m_len, mtod(n, void *), |
| 1100 | (unsigned)count); |
| 1101 | len -= count; |
| 1102 | m->m_len += count; |
| 1103 | n->m_len -= count; |
| 1104 | space -= count; |
| 1105 | if (n->m_len) |
| 1106 | n->m_data += count; |
| 1107 | else |
| 1108 | n = m_free(n); |
| 1109 | } while (len > 0 && n); |
| 1110 | if (len > 0) { |
| 1111 | (void) m_free(m); |
| 1112 | goto bad; |
| 1113 | } |
| 1114 | m->m_next = n; |
| 1115 | return (m); |
| 1116 | bad: |
| 1117 | m_freem(n); |
| 1118 | MSFail++; |
| 1119 | return (NULL); |
| 1120 | } |
| 1121 | |
| 1122 | /* |
| 1123 | * Partition an mbuf chain in two pieces, returning the tail -- |
| 1124 | * all but the first len0 bytes. In case of failure, it returns NULL and |
| 1125 | * attempts to restore the chain to its original state. |
| 1126 | */ |
| 1127 | struct mbuf * |
| 1128 | m_split(struct mbuf *m0, int len0, int wait) |
| 1129 | { |
| 1130 | |
| 1131 | return m_split0(m0, len0, wait, 1); |
| 1132 | } |
| 1133 | |
| 1134 | static struct mbuf * |
| 1135 | m_split0(struct mbuf *m0, int len0, int wait, int copyhdr) |
| 1136 | { |
| 1137 | struct mbuf *m, *n; |
| 1138 | unsigned len = len0, remain, len_save; |
| 1139 | |
| 1140 | KASSERT(len0 != M_COPYALL); |
| 1141 | for (m = m0; m && len > m->m_len; m = m->m_next) |
| 1142 | len -= m->m_len; |
| 1143 | if (m == 0) |
| 1144 | return (NULL); |
| 1145 | remain = m->m_len - len; |
| 1146 | if (copyhdr && (m0->m_flags & M_PKTHDR)) { |
| 1147 | n = m_gethdr(wait, m0->m_type); |
| 1148 | if (n == NULL) |
| 1149 | return NULL; |
| 1150 | MCLAIM(n, m0->m_owner); |
| 1151 | m_copy_rcvif(n, m0); |
| 1152 | n->m_pkthdr.len = m0->m_pkthdr.len - len0; |
| 1153 | len_save = m0->m_pkthdr.len; |
| 1154 | m0->m_pkthdr.len = len0; |
| 1155 | if (m->m_flags & M_EXT) |
| 1156 | goto extpacket; |
| 1157 | if (remain > MHLEN) { |
| 1158 | /* m can't be the lead packet */ |
| 1159 | MH_ALIGN(n, 0); |
| 1160 | n->m_len = 0; |
| 1161 | n->m_next = m_split(m, len, wait); |
| 1162 | if (n->m_next == 0) { |
| 1163 | (void) m_free(n); |
| 1164 | m0->m_pkthdr.len = len_save; |
| 1165 | return (NULL); |
| 1166 | } else |
| 1167 | return (n); |
| 1168 | } else |
| 1169 | MH_ALIGN(n, remain); |
| 1170 | } else if (remain == 0) { |
| 1171 | n = m->m_next; |
| 1172 | m->m_next = 0; |
| 1173 | return (n); |
| 1174 | } else { |
| 1175 | n = m_get(wait, m->m_type); |
| 1176 | if (n == 0) |
| 1177 | return (NULL); |
| 1178 | MCLAIM(n, m->m_owner); |
| 1179 | M_ALIGN(n, remain); |
| 1180 | } |
| 1181 | extpacket: |
| 1182 | if (m->m_flags & M_EXT) { |
| 1183 | n->m_data = m->m_data + len; |
| 1184 | MCLADDREFERENCE(m, n); |
| 1185 | } else { |
| 1186 | memcpy(mtod(n, void *), mtod(m, char *) + len, remain); |
| 1187 | } |
| 1188 | n->m_len = remain; |
| 1189 | m->m_len = len; |
| 1190 | n->m_next = m->m_next; |
| 1191 | m->m_next = 0; |
| 1192 | return (n); |
| 1193 | } |
| 1194 | /* |
| 1195 | * Routine to copy from device local memory into mbufs. |
| 1196 | */ |
| 1197 | struct mbuf * |
| 1198 | m_devget(char *buf, int totlen, int off0, struct ifnet *ifp, |
| 1199 | void (*copy)(const void *from, void *to, size_t len)) |
| 1200 | { |
| 1201 | struct mbuf *m; |
| 1202 | struct mbuf *top = 0, **mp = ⊤ |
| 1203 | int off = off0, len; |
| 1204 | char *cp; |
| 1205 | char *epkt; |
| 1206 | |
| 1207 | cp = buf; |
| 1208 | epkt = cp + totlen; |
| 1209 | if (off) { |
| 1210 | /* |
| 1211 | * If 'off' is non-zero, packet is trailer-encapsulated, |
| 1212 | * so we have to skip the type and length fields. |
| 1213 | */ |
| 1214 | cp += off + 2 * sizeof(uint16_t); |
| 1215 | totlen -= 2 * sizeof(uint16_t); |
| 1216 | } |
| 1217 | m = m_gethdr(M_DONTWAIT, MT_DATA); |
| 1218 | if (m == NULL) |
| 1219 | return NULL; |
| 1220 | m_set_rcvif(m, ifp); |
| 1221 | m->m_pkthdr.len = totlen; |
| 1222 | m->m_len = MHLEN; |
| 1223 | |
| 1224 | while (totlen > 0) { |
| 1225 | if (top) { |
| 1226 | m = m_get(M_DONTWAIT, MT_DATA); |
| 1227 | if (m == 0) { |
| 1228 | m_freem(top); |
| 1229 | return (NULL); |
| 1230 | } |
| 1231 | m->m_len = MLEN; |
| 1232 | } |
| 1233 | len = min(totlen, epkt - cp); |
| 1234 | if (len >= MINCLSIZE) { |
| 1235 | MCLGET(m, M_DONTWAIT); |
| 1236 | if ((m->m_flags & M_EXT) == 0) { |
| 1237 | m_free(m); |
| 1238 | m_freem(top); |
| 1239 | return (NULL); |
| 1240 | } |
| 1241 | m->m_len = len = min(len, MCLBYTES); |
| 1242 | } else { |
| 1243 | /* |
| 1244 | * Place initial small packet/header at end of mbuf. |
| 1245 | */ |
| 1246 | if (len < m->m_len) { |
| 1247 | if (top == 0 && len + max_linkhdr <= m->m_len) |
| 1248 | m->m_data += max_linkhdr; |
| 1249 | m->m_len = len; |
| 1250 | } else |
| 1251 | len = m->m_len; |
| 1252 | } |
| 1253 | if (copy) |
| 1254 | copy(cp, mtod(m, void *), (size_t)len); |
| 1255 | else |
| 1256 | memcpy(mtod(m, void *), cp, (size_t)len); |
| 1257 | cp += len; |
| 1258 | *mp = m; |
| 1259 | mp = &m->m_next; |
| 1260 | totlen -= len; |
| 1261 | if (cp == epkt) |
| 1262 | cp = buf; |
| 1263 | } |
| 1264 | return (top); |
| 1265 | } |
| 1266 | |
| 1267 | /* |
| 1268 | * Copy data from a buffer back into the indicated mbuf chain, |
| 1269 | * starting "off" bytes from the beginning, extending the mbuf |
| 1270 | * chain if necessary. |
| 1271 | */ |
| 1272 | void |
| 1273 | m_copyback(struct mbuf *m0, int off, int len, const void *cp) |
| 1274 | { |
| 1275 | #if defined(DEBUG) |
| 1276 | struct mbuf *origm = m0; |
| 1277 | int error; |
| 1278 | #endif /* defined(DEBUG) */ |
| 1279 | |
| 1280 | if (m0 == NULL) |
| 1281 | return; |
| 1282 | |
| 1283 | #if defined(DEBUG) |
| 1284 | error = |
| 1285 | #endif /* defined(DEBUG) */ |
| 1286 | m_copyback0(&m0, off, len, cp, |
| 1287 | M_COPYBACK0_COPYBACK|M_COPYBACK0_EXTEND, M_DONTWAIT); |
| 1288 | |
| 1289 | #if defined(DEBUG) |
| 1290 | if (error != 0 || (m0 != NULL && origm != m0)) |
| 1291 | panic("m_copyback" ); |
| 1292 | #endif /* defined(DEBUG) */ |
| 1293 | } |
| 1294 | |
| 1295 | struct mbuf * |
| 1296 | m_copyback_cow(struct mbuf *m0, int off, int len, const void *cp, int how) |
| 1297 | { |
| 1298 | int error; |
| 1299 | |
| 1300 | /* don't support chain expansion */ |
| 1301 | KASSERT(len != M_COPYALL); |
| 1302 | KDASSERT(off + len <= m_length(m0)); |
| 1303 | |
| 1304 | error = m_copyback0(&m0, off, len, cp, |
| 1305 | M_COPYBACK0_COPYBACK|M_COPYBACK0_COW, how); |
| 1306 | if (error) { |
| 1307 | /* |
| 1308 | * no way to recover from partial success. |
| 1309 | * just free the chain. |
| 1310 | */ |
| 1311 | m_freem(m0); |
| 1312 | return NULL; |
| 1313 | } |
| 1314 | return m0; |
| 1315 | } |
| 1316 | |
| 1317 | /* |
| 1318 | * m_makewritable: ensure the specified range writable. |
| 1319 | */ |
| 1320 | int |
| 1321 | m_makewritable(struct mbuf **mp, int off, int len, int how) |
| 1322 | { |
| 1323 | int error; |
| 1324 | #if defined(DEBUG) |
| 1325 | int origlen = m_length(*mp); |
| 1326 | #endif /* defined(DEBUG) */ |
| 1327 | |
| 1328 | error = m_copyback0(mp, off, len, NULL, |
| 1329 | M_COPYBACK0_PRESERVE|M_COPYBACK0_COW, how); |
| 1330 | |
| 1331 | #if defined(DEBUG) |
| 1332 | int reslen = 0; |
| 1333 | for (struct mbuf *n = *mp; n; n = n->m_next) |
| 1334 | reslen += n->m_len; |
| 1335 | if (origlen != reslen) |
| 1336 | panic("m_makewritable: length changed" ); |
| 1337 | if (((*mp)->m_flags & M_PKTHDR) != 0 && reslen != (*mp)->m_pkthdr.len) |
| 1338 | panic("m_makewritable: inconsist" ); |
| 1339 | #endif /* defined(DEBUG) */ |
| 1340 | |
| 1341 | return error; |
| 1342 | } |
| 1343 | |
| 1344 | /* |
| 1345 | * Copy the mbuf chain to a new mbuf chain that is as short as possible. |
| 1346 | * Return the new mbuf chain on success, NULL on failure. On success, |
| 1347 | * free the old mbuf chain. |
| 1348 | */ |
| 1349 | struct mbuf * |
| 1350 | m_defrag(struct mbuf *mold, int flags) |
| 1351 | { |
| 1352 | struct mbuf *m0, *mn, *n; |
| 1353 | size_t sz = mold->m_pkthdr.len; |
| 1354 | |
| 1355 | #ifdef DIAGNOSTIC |
| 1356 | if ((mold->m_flags & M_PKTHDR) == 0) |
| 1357 | panic("m_defrag: not a mbuf chain header" ); |
| 1358 | #endif |
| 1359 | |
| 1360 | m0 = m_gethdr(flags, MT_DATA); |
| 1361 | if (m0 == NULL) |
| 1362 | return NULL; |
| 1363 | M_COPY_PKTHDR(m0, mold); |
| 1364 | mn = m0; |
| 1365 | |
| 1366 | do { |
| 1367 | if (sz > MHLEN) { |
| 1368 | MCLGET(mn, M_DONTWAIT); |
| 1369 | if ((mn->m_flags & M_EXT) == 0) { |
| 1370 | m_freem(m0); |
| 1371 | return NULL; |
| 1372 | } |
| 1373 | } |
| 1374 | |
| 1375 | mn->m_len = MIN(sz, MCLBYTES); |
| 1376 | |
| 1377 | m_copydata(mold, mold->m_pkthdr.len - sz, mn->m_len, |
| 1378 | mtod(mn, void *)); |
| 1379 | |
| 1380 | sz -= mn->m_len; |
| 1381 | |
| 1382 | if (sz > 0) { |
| 1383 | /* need more mbufs */ |
| 1384 | n = m_get(M_NOWAIT, MT_DATA); |
| 1385 | if (n == NULL) { |
| 1386 | m_freem(m0); |
| 1387 | return NULL; |
| 1388 | } |
| 1389 | |
| 1390 | mn->m_next = n; |
| 1391 | mn = n; |
| 1392 | } |
| 1393 | } while (sz > 0); |
| 1394 | |
| 1395 | m_freem(mold); |
| 1396 | |
| 1397 | return m0; |
| 1398 | } |
| 1399 | |
| 1400 | int |
| 1401 | m_copyback0(struct mbuf **mp0, int off, int len, const void *vp, int flags, |
| 1402 | int how) |
| 1403 | { |
| 1404 | int mlen; |
| 1405 | struct mbuf *m, *n; |
| 1406 | struct mbuf **mp; |
| 1407 | int totlen = 0; |
| 1408 | const char *cp = vp; |
| 1409 | |
| 1410 | KASSERT(mp0 != NULL); |
| 1411 | KASSERT(*mp0 != NULL); |
| 1412 | KASSERT((flags & M_COPYBACK0_PRESERVE) == 0 || cp == NULL); |
| 1413 | KASSERT((flags & M_COPYBACK0_COPYBACK) == 0 || cp != NULL); |
| 1414 | |
| 1415 | if (len == M_COPYALL) |
| 1416 | len = m_length(*mp0) - off; |
| 1417 | |
| 1418 | /* |
| 1419 | * we don't bother to update "totlen" in the case of M_COPYBACK0_COW, |
| 1420 | * assuming that M_COPYBACK0_EXTEND and M_COPYBACK0_COW are exclusive. |
| 1421 | */ |
| 1422 | |
| 1423 | KASSERT((~flags & (M_COPYBACK0_EXTEND|M_COPYBACK0_COW)) != 0); |
| 1424 | |
| 1425 | mp = mp0; |
| 1426 | m = *mp; |
| 1427 | while (off > (mlen = m->m_len)) { |
| 1428 | off -= mlen; |
| 1429 | totlen += mlen; |
| 1430 | if (m->m_next == NULL) { |
| 1431 | int tspace; |
| 1432 | extend: |
| 1433 | if ((flags & M_COPYBACK0_EXTEND) == 0) |
| 1434 | goto out; |
| 1435 | |
| 1436 | /* |
| 1437 | * try to make some space at the end of "m". |
| 1438 | */ |
| 1439 | |
| 1440 | mlen = m->m_len; |
| 1441 | if (off + len >= MINCLSIZE && |
| 1442 | (m->m_flags & M_EXT) == 0 && m->m_len == 0) { |
| 1443 | MCLGET(m, how); |
| 1444 | } |
| 1445 | tspace = M_TRAILINGSPACE(m); |
| 1446 | if (tspace > 0) { |
| 1447 | tspace = min(tspace, off + len); |
| 1448 | KASSERT(tspace > 0); |
| 1449 | memset(mtod(m, char *) + m->m_len, 0, |
| 1450 | min(off, tspace)); |
| 1451 | m->m_len += tspace; |
| 1452 | off += mlen; |
| 1453 | totlen -= mlen; |
| 1454 | continue; |
| 1455 | } |
| 1456 | |
| 1457 | /* |
| 1458 | * need to allocate an mbuf. |
| 1459 | */ |
| 1460 | |
| 1461 | if (off + len >= MINCLSIZE) { |
| 1462 | n = m_getcl(how, m->m_type, 0); |
| 1463 | } else { |
| 1464 | n = m_get(how, m->m_type); |
| 1465 | } |
| 1466 | if (n == NULL) { |
| 1467 | goto out; |
| 1468 | } |
| 1469 | n->m_len = min(M_TRAILINGSPACE(n), off + len); |
| 1470 | memset(mtod(n, char *), 0, min(n->m_len, off)); |
| 1471 | m->m_next = n; |
| 1472 | } |
| 1473 | mp = &m->m_next; |
| 1474 | m = m->m_next; |
| 1475 | } |
| 1476 | while (len > 0) { |
| 1477 | mlen = m->m_len - off; |
| 1478 | if (mlen != 0 && M_READONLY(m)) { |
| 1479 | char *datap; |
| 1480 | int eatlen; |
| 1481 | |
| 1482 | /* |
| 1483 | * this mbuf is read-only. |
| 1484 | * allocate a new writable mbuf and try again. |
| 1485 | */ |
| 1486 | |
| 1487 | #if defined(DIAGNOSTIC) |
| 1488 | if ((flags & M_COPYBACK0_COW) == 0) |
| 1489 | panic("m_copyback0: read-only" ); |
| 1490 | #endif /* defined(DIAGNOSTIC) */ |
| 1491 | |
| 1492 | /* |
| 1493 | * if we're going to write into the middle of |
| 1494 | * a mbuf, split it first. |
| 1495 | */ |
| 1496 | if (off > 0) { |
| 1497 | n = m_split0(m, off, how, 0); |
| 1498 | if (n == NULL) |
| 1499 | goto enobufs; |
| 1500 | m->m_next = n; |
| 1501 | mp = &m->m_next; |
| 1502 | m = n; |
| 1503 | off = 0; |
| 1504 | continue; |
| 1505 | } |
| 1506 | |
| 1507 | /* |
| 1508 | * XXX TODO coalesce into the trailingspace of |
| 1509 | * the previous mbuf when possible. |
| 1510 | */ |
| 1511 | |
| 1512 | /* |
| 1513 | * allocate a new mbuf. copy packet header if needed. |
| 1514 | */ |
| 1515 | n = m_get(how, m->m_type); |
| 1516 | if (n == NULL) |
| 1517 | goto enobufs; |
| 1518 | MCLAIM(n, m->m_owner); |
| 1519 | if (off == 0 && (m->m_flags & M_PKTHDR) != 0) { |
| 1520 | M_MOVE_PKTHDR(n, m); |
| 1521 | n->m_len = MHLEN; |
| 1522 | } else { |
| 1523 | if (len >= MINCLSIZE) |
| 1524 | MCLGET(n, M_DONTWAIT); |
| 1525 | n->m_len = |
| 1526 | (n->m_flags & M_EXT) ? MCLBYTES : MLEN; |
| 1527 | } |
| 1528 | if (n->m_len > len) |
| 1529 | n->m_len = len; |
| 1530 | |
| 1531 | /* |
| 1532 | * free the region which has been overwritten. |
| 1533 | * copying data from old mbufs if requested. |
| 1534 | */ |
| 1535 | if (flags & M_COPYBACK0_PRESERVE) |
| 1536 | datap = mtod(n, char *); |
| 1537 | else |
| 1538 | datap = NULL; |
| 1539 | eatlen = n->m_len; |
| 1540 | while (m != NULL && M_READONLY(m) && |
| 1541 | n->m_type == m->m_type && eatlen > 0) { |
| 1542 | mlen = min(eatlen, m->m_len); |
| 1543 | if (datap) { |
| 1544 | m_copydata(m, 0, mlen, datap); |
| 1545 | datap += mlen; |
| 1546 | } |
| 1547 | m->m_data += mlen; |
| 1548 | m->m_len -= mlen; |
| 1549 | eatlen -= mlen; |
| 1550 | if (m->m_len == 0) |
| 1551 | *mp = m = m_free(m); |
| 1552 | } |
| 1553 | if (eatlen > 0) |
| 1554 | n->m_len -= eatlen; |
| 1555 | n->m_next = m; |
| 1556 | *mp = m = n; |
| 1557 | continue; |
| 1558 | } |
| 1559 | mlen = min(mlen, len); |
| 1560 | if (flags & M_COPYBACK0_COPYBACK) { |
| 1561 | memcpy(mtod(m, char *) + off, cp, (unsigned)mlen); |
| 1562 | cp += mlen; |
| 1563 | } |
| 1564 | len -= mlen; |
| 1565 | mlen += off; |
| 1566 | off = 0; |
| 1567 | totlen += mlen; |
| 1568 | if (len == 0) |
| 1569 | break; |
| 1570 | if (m->m_next == NULL) { |
| 1571 | goto extend; |
| 1572 | } |
| 1573 | mp = &m->m_next; |
| 1574 | m = m->m_next; |
| 1575 | } |
| 1576 | out: if (((m = *mp0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) { |
| 1577 | KASSERT((flags & M_COPYBACK0_EXTEND) != 0); |
| 1578 | m->m_pkthdr.len = totlen; |
| 1579 | } |
| 1580 | |
| 1581 | return 0; |
| 1582 | |
| 1583 | enobufs: |
| 1584 | return ENOBUFS; |
| 1585 | } |
| 1586 | |
| 1587 | void |
| 1588 | m_move_pkthdr(struct mbuf *to, struct mbuf *from) |
| 1589 | { |
| 1590 | |
| 1591 | KASSERT((to->m_flags & M_EXT) == 0); |
| 1592 | KASSERT((to->m_flags & M_PKTHDR) == 0 || m_tag_first(to) == NULL); |
| 1593 | KASSERT((from->m_flags & M_PKTHDR) != 0); |
| 1594 | |
| 1595 | to->m_pkthdr = from->m_pkthdr; |
| 1596 | to->m_flags = from->m_flags & M_COPYFLAGS; |
| 1597 | to->m_data = to->m_pktdat; |
| 1598 | |
| 1599 | from->m_flags &= ~M_PKTHDR; |
| 1600 | } |
| 1601 | |
| 1602 | /* |
| 1603 | * Apply function f to the data in an mbuf chain starting "off" bytes from the |
| 1604 | * beginning, continuing for "len" bytes. |
| 1605 | */ |
| 1606 | int |
| 1607 | m_apply(struct mbuf *m, int off, int len, |
| 1608 | int (*f)(void *, void *, unsigned int), void *arg) |
| 1609 | { |
| 1610 | unsigned int count; |
| 1611 | int rval; |
| 1612 | |
| 1613 | KASSERT(len != M_COPYALL); |
| 1614 | KASSERT(len >= 0); |
| 1615 | KASSERT(off >= 0); |
| 1616 | |
| 1617 | while (off > 0) { |
| 1618 | KASSERT(m != NULL); |
| 1619 | if (off < m->m_len) |
| 1620 | break; |
| 1621 | off -= m->m_len; |
| 1622 | m = m->m_next; |
| 1623 | } |
| 1624 | while (len > 0) { |
| 1625 | KASSERT(m != NULL); |
| 1626 | count = min(m->m_len - off, len); |
| 1627 | |
| 1628 | rval = (*f)(arg, mtod(m, char *) + off, count); |
| 1629 | if (rval) |
| 1630 | return (rval); |
| 1631 | |
| 1632 | len -= count; |
| 1633 | off = 0; |
| 1634 | m = m->m_next; |
| 1635 | } |
| 1636 | |
| 1637 | return (0); |
| 1638 | } |
| 1639 | |
| 1640 | /* |
| 1641 | * Return a pointer to mbuf/offset of location in mbuf chain. |
| 1642 | */ |
| 1643 | struct mbuf * |
| 1644 | m_getptr(struct mbuf *m, int loc, int *off) |
| 1645 | { |
| 1646 | |
| 1647 | while (loc >= 0) { |
| 1648 | /* Normal end of search */ |
| 1649 | if (m->m_len > loc) { |
| 1650 | *off = loc; |
| 1651 | return (m); |
| 1652 | } else { |
| 1653 | loc -= m->m_len; |
| 1654 | |
| 1655 | if (m->m_next == NULL) { |
| 1656 | if (loc == 0) { |
| 1657 | /* Point at the end of valid data */ |
| 1658 | *off = m->m_len; |
| 1659 | return (m); |
| 1660 | } else |
| 1661 | return (NULL); |
| 1662 | } else |
| 1663 | m = m->m_next; |
| 1664 | } |
| 1665 | } |
| 1666 | |
| 1667 | return (NULL); |
| 1668 | } |
| 1669 | |
| 1670 | /* |
| 1671 | * m_ext_free: release a reference to the mbuf external storage. |
| 1672 | * |
| 1673 | * => free the mbuf m itself as well. |
| 1674 | */ |
| 1675 | |
| 1676 | void |
| 1677 | m_ext_free(struct mbuf *m) |
| 1678 | { |
| 1679 | bool embedded = MEXT_ISEMBEDDED(m); |
| 1680 | bool dofree = true; |
| 1681 | u_int refcnt; |
| 1682 | |
| 1683 | KASSERT((m->m_flags & M_EXT) != 0); |
| 1684 | KASSERT(MEXT_ISEMBEDDED(m->m_ext_ref)); |
| 1685 | KASSERT((m->m_ext_ref->m_flags & M_EXT) != 0); |
| 1686 | KASSERT((m->m_flags & M_EXT_CLUSTER) == |
| 1687 | (m->m_ext_ref->m_flags & M_EXT_CLUSTER)); |
| 1688 | |
| 1689 | if (__predict_true(m->m_ext.ext_refcnt == 1)) { |
| 1690 | refcnt = m->m_ext.ext_refcnt = 0; |
| 1691 | } else { |
| 1692 | refcnt = atomic_dec_uint_nv(&m->m_ext.ext_refcnt); |
| 1693 | } |
| 1694 | if (refcnt > 0) { |
| 1695 | if (embedded) { |
| 1696 | /* |
| 1697 | * other mbuf's m_ext_ref still points to us. |
| 1698 | */ |
| 1699 | dofree = false; |
| 1700 | } else { |
| 1701 | m->m_ext_ref = m; |
| 1702 | } |
| 1703 | } else { |
| 1704 | /* |
| 1705 | * dropping the last reference |
| 1706 | */ |
| 1707 | if (!embedded) { |
| 1708 | m->m_ext.ext_refcnt++; /* XXX */ |
| 1709 | m_ext_free(m->m_ext_ref); |
| 1710 | m->m_ext_ref = m; |
| 1711 | } else if ((m->m_flags & M_EXT_CLUSTER) != 0) { |
| 1712 | pool_cache_put_paddr((struct pool_cache *) |
| 1713 | m->m_ext.ext_arg, |
| 1714 | m->m_ext.ext_buf, m->m_ext.ext_paddr); |
| 1715 | } else if (m->m_ext.ext_free) { |
| 1716 | (*m->m_ext.ext_free)(m, |
| 1717 | m->m_ext.ext_buf, m->m_ext.ext_size, |
| 1718 | m->m_ext.ext_arg); |
| 1719 | /* |
| 1720 | * 'm' is already freed by the ext_free callback. |
| 1721 | */ |
| 1722 | dofree = false; |
| 1723 | } else { |
| 1724 | free(m->m_ext.ext_buf, m->m_ext.ext_type); |
| 1725 | } |
| 1726 | } |
| 1727 | if (dofree) { |
| 1728 | m->m_type = MT_FREE; |
| 1729 | pool_cache_put(mb_cache, m); |
| 1730 | } |
| 1731 | } |
| 1732 | |
| 1733 | #if defined(DDB) |
| 1734 | void |
| 1735 | m_print(const struct mbuf *m, const char *modif, void (*pr)(const char *, ...)) |
| 1736 | { |
| 1737 | char ch; |
| 1738 | bool opt_c = false; |
| 1739 | char buf[512]; |
| 1740 | |
| 1741 | while ((ch = *(modif++)) != '\0') { |
| 1742 | switch (ch) { |
| 1743 | case 'c': |
| 1744 | opt_c = true; |
| 1745 | break; |
| 1746 | } |
| 1747 | } |
| 1748 | |
| 1749 | nextchain: |
| 1750 | (*pr)("MBUF %p\n" , m); |
| 1751 | snprintb(buf, sizeof(buf), M_FLAGS_BITS, (u_int)m->m_flags); |
| 1752 | (*pr)(" data=%p, len=%d, type=%d, flags=%s\n" , |
| 1753 | m->m_data, m->m_len, m->m_type, buf); |
| 1754 | (*pr)(" owner=%p, next=%p, nextpkt=%p\n" , m->m_owner, m->m_next, |
| 1755 | m->m_nextpkt); |
| 1756 | (*pr)(" leadingspace=%u, trailingspace=%u, readonly=%u\n" , |
| 1757 | (int)M_LEADINGSPACE(m), (int)M_TRAILINGSPACE(m), |
| 1758 | (int)M_READONLY(m)); |
| 1759 | if ((m->m_flags & M_PKTHDR) != 0) { |
| 1760 | snprintb(buf, sizeof(buf), M_CSUM_BITS, m->m_pkthdr.csum_flags); |
| 1761 | (*pr)(" pktlen=%d, rcvif=%p, csum_flags=0x%s, csum_data=0x%" |
| 1762 | PRIx32 ", segsz=%u\n" , |
| 1763 | m->m_pkthdr.len, m_get_rcvif_NOMPSAFE(m), |
| 1764 | buf, m->m_pkthdr.csum_data, m->m_pkthdr.segsz); |
| 1765 | } |
| 1766 | if ((m->m_flags & M_EXT)) { |
| 1767 | (*pr)(" ext_refcnt=%u, ext_buf=%p, ext_size=%zd, " |
| 1768 | "ext_free=%p, ext_arg=%p\n" , |
| 1769 | m->m_ext.ext_refcnt, |
| 1770 | m->m_ext.ext_buf, m->m_ext.ext_size, |
| 1771 | m->m_ext.ext_free, m->m_ext.ext_arg); |
| 1772 | } |
| 1773 | if ((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0) { |
| 1774 | vaddr_t sva = (vaddr_t)m->m_ext.ext_buf; |
| 1775 | vaddr_t eva = sva + m->m_ext.ext_size; |
| 1776 | int n = (round_page(eva) - trunc_page(sva)) >> PAGE_SHIFT; |
| 1777 | int i; |
| 1778 | |
| 1779 | (*pr)(" pages:" ); |
| 1780 | for (i = 0; i < n; i ++) { |
| 1781 | (*pr)(" %p" , m->m_ext.ext_pgs[i]); |
| 1782 | } |
| 1783 | (*pr)("\n" ); |
| 1784 | } |
| 1785 | |
| 1786 | if (opt_c) { |
| 1787 | m = m->m_next; |
| 1788 | if (m != NULL) { |
| 1789 | goto nextchain; |
| 1790 | } |
| 1791 | } |
| 1792 | } |
| 1793 | #endif /* defined(DDB) */ |
| 1794 | |
| 1795 | void |
| 1796 | mbstat_type_add(int type, int diff) |
| 1797 | { |
| 1798 | struct mbstat_cpu *mb; |
| 1799 | int s; |
| 1800 | |
| 1801 | s = splvm(); |
| 1802 | mb = percpu_getref(mbstat_percpu); |
| 1803 | mb->m_mtypes[type] += diff; |
| 1804 | percpu_putref(mbstat_percpu); |
| 1805 | splx(s); |
| 1806 | } |
| 1807 | |
| 1808 | #if defined(MBUFTRACE) |
| 1809 | void |
| 1810 | mowner_attach(struct mowner *mo) |
| 1811 | { |
| 1812 | |
| 1813 | KASSERT(mo->mo_counters == NULL); |
| 1814 | mo->mo_counters = percpu_alloc(sizeof(struct mowner_counter)); |
| 1815 | |
| 1816 | /* XXX lock */ |
| 1817 | LIST_INSERT_HEAD(&mowners, mo, mo_link); |
| 1818 | } |
| 1819 | |
| 1820 | void |
| 1821 | mowner_detach(struct mowner *mo) |
| 1822 | { |
| 1823 | |
| 1824 | KASSERT(mo->mo_counters != NULL); |
| 1825 | |
| 1826 | /* XXX lock */ |
| 1827 | LIST_REMOVE(mo, mo_link); |
| 1828 | |
| 1829 | percpu_free(mo->mo_counters, sizeof(struct mowner_counter)); |
| 1830 | mo->mo_counters = NULL; |
| 1831 | } |
| 1832 | |
| 1833 | void |
| 1834 | mowner_init(struct mbuf *m, int type) |
| 1835 | { |
| 1836 | struct mowner_counter *mc; |
| 1837 | struct mowner *mo; |
| 1838 | int s; |
| 1839 | |
| 1840 | m->m_owner = mo = &unknown_mowners[type]; |
| 1841 | s = splvm(); |
| 1842 | mc = percpu_getref(mo->mo_counters); |
| 1843 | mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; |
| 1844 | percpu_putref(mo->mo_counters); |
| 1845 | splx(s); |
| 1846 | } |
| 1847 | |
| 1848 | void |
| 1849 | mowner_ref(struct mbuf *m, int flags) |
| 1850 | { |
| 1851 | struct mowner *mo = m->m_owner; |
| 1852 | struct mowner_counter *mc; |
| 1853 | int s; |
| 1854 | |
| 1855 | s = splvm(); |
| 1856 | mc = percpu_getref(mo->mo_counters); |
| 1857 | if ((flags & M_EXT) != 0) |
| 1858 | mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; |
| 1859 | if ((flags & M_CLUSTER) != 0) |
| 1860 | mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; |
| 1861 | percpu_putref(mo->mo_counters); |
| 1862 | splx(s); |
| 1863 | } |
| 1864 | |
| 1865 | void |
| 1866 | mowner_revoke(struct mbuf *m, bool all, int flags) |
| 1867 | { |
| 1868 | struct mowner *mo = m->m_owner; |
| 1869 | struct mowner_counter *mc; |
| 1870 | int s; |
| 1871 | |
| 1872 | s = splvm(); |
| 1873 | mc = percpu_getref(mo->mo_counters); |
| 1874 | if ((flags & M_EXT) != 0) |
| 1875 | mc->mc_counter[MOWNER_COUNTER_EXT_RELEASES]++; |
| 1876 | if ((flags & M_CLUSTER) != 0) |
| 1877 | mc->mc_counter[MOWNER_COUNTER_CLUSTER_RELEASES]++; |
| 1878 | if (all) |
| 1879 | mc->mc_counter[MOWNER_COUNTER_RELEASES]++; |
| 1880 | percpu_putref(mo->mo_counters); |
| 1881 | splx(s); |
| 1882 | if (all) |
| 1883 | m->m_owner = &revoked_mowner; |
| 1884 | } |
| 1885 | |
| 1886 | static void |
| 1887 | mowner_claim(struct mbuf *m, struct mowner *mo) |
| 1888 | { |
| 1889 | struct mowner_counter *mc; |
| 1890 | int flags = m->m_flags; |
| 1891 | int s; |
| 1892 | |
| 1893 | s = splvm(); |
| 1894 | mc = percpu_getref(mo->mo_counters); |
| 1895 | mc->mc_counter[MOWNER_COUNTER_CLAIMS]++; |
| 1896 | if ((flags & M_EXT) != 0) |
| 1897 | mc->mc_counter[MOWNER_COUNTER_EXT_CLAIMS]++; |
| 1898 | if ((flags & M_CLUSTER) != 0) |
| 1899 | mc->mc_counter[MOWNER_COUNTER_CLUSTER_CLAIMS]++; |
| 1900 | percpu_putref(mo->mo_counters); |
| 1901 | splx(s); |
| 1902 | m->m_owner = mo; |
| 1903 | } |
| 1904 | |
| 1905 | void |
| 1906 | m_claim(struct mbuf *m, struct mowner *mo) |
| 1907 | { |
| 1908 | |
| 1909 | if (m->m_owner == mo || mo == NULL) |
| 1910 | return; |
| 1911 | |
| 1912 | mowner_revoke(m, true, m->m_flags); |
| 1913 | mowner_claim(m, mo); |
| 1914 | } |
| 1915 | #endif /* defined(MBUFTRACE) */ |
| 1916 | |
| 1917 | /* |
| 1918 | * MFREE(struct mbuf *m, struct mbuf *n) |
| 1919 | * Free a single mbuf and associated external storage. |
| 1920 | * Place the successor, if any, in n. |
| 1921 | */ |
| 1922 | #define MFREE(f, l, m, n) \ |
| 1923 | mowner_revoke((m), 1, (m)->m_flags); \ |
| 1924 | mbstat_type_add((m)->m_type, -1); \ |
| 1925 | if ((m)->m_flags & M_PKTHDR) \ |
| 1926 | m_tag_delete_chain((m), NULL); \ |
| 1927 | (n) = (m)->m_next; \ |
| 1928 | if ((m)->m_flags & M_EXT) { \ |
| 1929 | m_ext_free((m)); \ |
| 1930 | } else { \ |
| 1931 | MBUFFREE(f, l, m); \ |
| 1932 | } \ |
| 1933 | |
| 1934 | #ifdef DEBUG |
| 1935 | #define MBUFFREE(f, l, m) \ |
| 1936 | do { \ |
| 1937 | if ((m)->m_type == MT_FREE) \ |
| 1938 | panic("mbuf was already freed at %s,%d", \ |
| 1939 | m->m_data, m->m_len); \ |
| 1940 | (m)->m_type = MT_FREE; \ |
| 1941 | (m)->m_data = __UNCONST(f); \ |
| 1942 | (m)->m_len = l; \ |
| 1943 | pool_cache_put(mb_cache, (m)); \ |
| 1944 | } while (/*CONSTCOND*/0) |
| 1945 | |
| 1946 | #else |
| 1947 | #define MBUFFREE(f, l, m) \ |
| 1948 | do { \ |
| 1949 | KASSERT((m)->m_type != MT_FREE); \ |
| 1950 | (m)->m_type = MT_FREE; \ |
| 1951 | pool_cache_put(mb_cache, (m)); \ |
| 1952 | } while (/*CONSTCOND*/0) |
| 1953 | #endif |
| 1954 | |
| 1955 | struct mbuf * |
| 1956 | m__free(const char *f, int l, struct mbuf *m) |
| 1957 | { |
| 1958 | struct mbuf *n; |
| 1959 | |
| 1960 | MFREE(f, l, m, n); |
| 1961 | return (n); |
| 1962 | } |
| 1963 | |
| 1964 | void |
| 1965 | m__freem(const char *f, int l, struct mbuf *m) |
| 1966 | { |
| 1967 | struct mbuf *n; |
| 1968 | |
| 1969 | if (m == NULL) |
| 1970 | return; |
| 1971 | do { |
| 1972 | MFREE(f, l, m, n); |
| 1973 | m = n; |
| 1974 | } while (m); |
| 1975 | } |
| 1976 | |
| 1977 | #undef m_free |
| 1978 | struct mbuf *m_free(struct mbuf *); |
| 1979 | struct mbuf * |
| 1980 | m_free(struct mbuf *m) |
| 1981 | { |
| 1982 | return m__free(__func__, __LINE__, m); |
| 1983 | } |
| 1984 | |
| 1985 | #undef m_freem |
| 1986 | void m_freem(struct mbuf *); |
| 1987 | void |
| 1988 | m_freem(struct mbuf *m) |
| 1989 | { |
| 1990 | m__freem(__func__, __LINE__, m); |
| 1991 | } |
| 1992 | |