1 /*- 2 * Copyright (c) 2009-2012 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This material is based upon work partially supported by The 6 * NetBSD Foundation under a contract with Mindaugas Rasiukevicius. 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * NPF network buffer management interface. 32 * 33 * Network buffer in NetBSD is mbuf. Internal mbuf structures are 34 * abstracted within this source. 35 */ 36 37 #ifdef _KERNEL 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: npf_mbuf.c,v 1.23 2019/09/26 18:44:45 christos Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/mbuf.h> 43 #include <netinet/in_offload.h> 44 #endif 45 46 #include "npf_impl.h" 47 48 #ifdef _KERNEL 49 #ifdef INET6 50 #include <netinet6/in6.h> 51 #include <netinet6/in6_offload.h> 52 #endif 53 #endif 54 55 #if defined(_NPF_STANDALONE) 56 #define m_length(m) (nbuf)->nb_mops->getchainlen(m) 57 #define m_buflen(m) (nbuf)->nb_mops->getlen(m) 58 #define m_next_ptr(m) (nbuf)->nb_mops->getnext(m) 59 #define m_ensure_contig(m,t) (nbuf)->nb_mops->ensure_contig((m), (t)) 60 #define m_makewritable(m,o,l,f) (nbuf)->nb_mops->ensure_writable((m), (o+l)) 61 #define mtod(m,t) ((t)((nbuf)->nb_mops->getdata(m))) 62 #define m_flags_p(m,f) true 63 #else 64 #define m_next_ptr(m) (m)->m_next 65 #define m_buflen(m) ((size_t)(m)->m_len) 66 #define m_flags_p(m,f) (((m)->m_flags & (f)) != 0) 67 #endif 68 69 #define NBUF_ENSURE_ALIGN (MAX(COHERENCY_UNIT, 64)) 70 #define NBUF_ENSURE_MASK (NBUF_ENSURE_ALIGN - 1) 71 #define NBUF_ENSURE_ROUNDUP(x) (((x) + NBUF_ENSURE_ALIGN) & ~NBUF_ENSURE_MASK) 72 73 void 74 nbuf_init(npf_t *npf, nbuf_t *nbuf, struct mbuf *m, const ifnet_t *ifp) 75 { 76 u_int ifid = npf_ifmap_getid(npf, ifp); 77 78 KASSERT(m_flags_p(m, M_PKTHDR)); 79 nbuf->nb_mops = npf->mbufops; 80 81 nbuf->nb_mbuf0 = m; 82 nbuf->nb_ifp = ifp; 83 nbuf->nb_ifid = ifid; 84 nbuf_reset(nbuf); 85 } 86 87 void 88 nbuf_reset(nbuf_t *nbuf) 89 { 90 struct mbuf *m = nbuf->nb_mbuf0; 91 92 nbuf->nb_mbuf = m; 93 nbuf->nb_nptr = mtod(m, void *); 94 } 95 96 void * 97 nbuf_dataptr(nbuf_t *nbuf) 98 { 99 KASSERT(nbuf->nb_nptr); 100 return nbuf->nb_nptr; 101 } 102 103 size_t 104 nbuf_offset(const nbuf_t *nbuf) 105 { 106 const struct mbuf *m = nbuf->nb_mbuf; 107 const u_int off = (uintptr_t)nbuf->nb_nptr - mtod(m, uintptr_t); 108 const int poff = m_length(nbuf->nb_mbuf0) - m_length(m) + off; 109 110 return poff; 111 } 112 113 struct mbuf * 114 nbuf_head_mbuf(nbuf_t *nbuf) 115 { 116 return nbuf->nb_mbuf0; 117 } 118 119 bool 120 nbuf_flag_p(const nbuf_t *nbuf, int flag) 121 { 122 return (nbuf->nb_flags & flag) != 0; 123 } 124 125 void 126 nbuf_unset_flag(nbuf_t *nbuf, int flag) 127 { 128 nbuf->nb_flags &= ~flag; 129 } 130 131 /* 132 * nbuf_advance: advance in nbuf or chain by specified amount of bytes and, 133 * if requested, ensure that the area *after* advance is contiguous. 134 * 135 * => Returns new pointer to data in nbuf or NULL if offset is invalid. 136 * => Current nbuf and the offset is stored in the nbuf metadata. 137 */ 138 void * 139 nbuf_advance(nbuf_t *nbuf, size_t len, size_t ensure) 140 { 141 struct mbuf *m = nbuf->nb_mbuf; 142 u_int off, wmark; 143 uint8_t *d; 144 145 /* Offset with amount to advance. */ 146 off = (uintptr_t)nbuf->nb_nptr - mtod(m, uintptr_t) + len; 147 wmark = m_buflen(m); 148 149 /* Find the mbuf according to offset. */ 150 while (__predict_false(wmark <= off)) { 151 m = m_next_ptr(m); 152 if (__predict_false(m == NULL)) { 153 /* 154 * If end of the chain, then the offset is 155 * higher than packet length. 156 */ 157 return NULL; 158 } 159 wmark += m_buflen(m); 160 } 161 KASSERT(off < m_length(nbuf->nb_mbuf0)); 162 163 /* Offset in mbuf data. */ 164 d = mtod(m, uint8_t *); 165 KASSERT(off >= (wmark - m_buflen(m))); 166 d += (off - (wmark - m_buflen(m))); 167 168 nbuf->nb_mbuf = m; 169 nbuf->nb_nptr = d; 170 171 if (ensure) { 172 /* Ensure contiguousness (may change nbuf chain). */ 173 d = nbuf_ensure_contig(nbuf, ensure); 174 } 175 return d; 176 } 177 178 /* 179 * nbuf_ensure_contig: check whether the specified length from the current 180 * point in the nbuf is contiguous. If not, rearrange the chain to be so. 181 * 182 * => Returns pointer to the data at the current offset in the buffer. 183 * => Returns NULL on failure and nbuf becomes invalid. 184 */ 185 void * 186 nbuf_ensure_contig(nbuf_t *nbuf, size_t len) 187 { 188 const struct mbuf * const n = nbuf->nb_mbuf; 189 const size_t off = (uintptr_t)nbuf->nb_nptr - mtod(n, uintptr_t); 190 191 KASSERT(off <= m_buflen(n)); 192 193 if (__predict_false(m_buflen(n) < (off + len))) { 194 struct mbuf *m = nbuf->nb_mbuf0; 195 const size_t foff = nbuf_offset(nbuf); 196 const size_t plen = m_length(m); 197 const size_t mlen = m_buflen(m); 198 size_t target; 199 bool success; 200 201 //npf_stats_inc(npf, NPF_STAT_NBUF_NONCONTIG); 202 203 /* Attempt to round-up to NBUF_ENSURE_ALIGN bytes. */ 204 if ((target = NBUF_ENSURE_ROUNDUP(foff + len)) > plen) { 205 target = foff + len; 206 } 207 208 /* Rearrange the chain to be contiguous. */ 209 KASSERT(m_flags_p(m, M_PKTHDR)); 210 success = m_ensure_contig(&m, target); 211 KASSERT(m != NULL); 212 213 /* If no change in the chain: return what we have. */ 214 if (m == nbuf->nb_mbuf0 && m_buflen(m) == mlen) { 215 return success ? nbuf->nb_nptr : NULL; 216 } 217 218 /* 219 * The mbuf chain was re-arranged. Update the pointers 220 * accordingly and indicate that the references to the data 221 * might need a reset. 222 */ 223 KASSERT(m_flags_p(m, M_PKTHDR)); 224 nbuf->nb_mbuf0 = m; 225 nbuf->nb_mbuf = m; 226 227 KASSERT(foff < m_buflen(m) && foff < m_length(m)); 228 nbuf->nb_nptr = mtod(m, uint8_t *) + foff; 229 nbuf->nb_flags |= NBUF_DATAREF_RESET; 230 231 if (!success) { 232 //npf_stats_inc(npf, NPF_STAT_NBUF_CONTIG_FAIL); 233 return NULL; 234 } 235 } 236 return nbuf->nb_nptr; 237 } 238 239 void * 240 nbuf_ensure_writable(nbuf_t *nbuf, size_t len) 241 { 242 struct mbuf *m = nbuf->nb_mbuf; 243 const u_int off = (uintptr_t)nbuf->nb_nptr - mtod(m, uintptr_t); 244 const int tlen = off + len; 245 bool head_buf; 246 247 KASSERT(off < m_length(nbuf->nb_mbuf0)); 248 249 if (!M_UNWRITABLE(m, tlen)) { 250 return nbuf->nb_nptr; 251 } 252 head_buf = (nbuf->nb_mbuf0 == m); 253 if (m_makewritable(&m, 0, tlen, M_NOWAIT)) { 254 memset(nbuf, 0, sizeof(nbuf_t)); 255 return NULL; 256 } 257 if (head_buf) { 258 KASSERT(m_flags_p(m, M_PKTHDR)); 259 KASSERT(off < m_length(m)); 260 nbuf->nb_mbuf0 = m; 261 } 262 nbuf->nb_mbuf = m; 263 nbuf->nb_nptr = mtod(m, uint8_t *) + off; 264 265 return nbuf->nb_nptr; 266 } 267 268 bool 269 nbuf_cksum_barrier(nbuf_t *nbuf, int di) 270 { 271 #ifdef _KERNEL 272 struct mbuf *m; 273 274 if (di != PFIL_OUT) { 275 return false; 276 } 277 m = nbuf->nb_mbuf0; 278 KASSERT(m_flags_p(m, M_PKTHDR)); 279 280 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4 | M_CSUM_UDPv4)) { 281 in_undefer_cksum_tcpudp(m); 282 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4 | M_CSUM_UDPv4); 283 return true; 284 } 285 #ifdef INET6 286 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv6 | M_CSUM_UDPv6)) { 287 in6_undefer_cksum_tcpudp(m); 288 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv6 | M_CSUM_UDPv6); 289 return true; 290 } 291 #endif 292 #else 293 (void)nbuf; (void)di; 294 #endif 295 return false; 296 } 297 298 /* 299 * nbuf_add_tag: add a tag to specified network buffer. 300 * 301 * => Returns 0 on success or errno on failure. 302 */ 303 int 304 nbuf_add_tag(nbuf_t *nbuf, uint32_t val) 305 { 306 #ifdef _KERNEL 307 struct mbuf *m = nbuf->nb_mbuf0; 308 struct m_tag *mt; 309 uint32_t *dat; 310 311 KASSERT(m_flags_p(m, M_PKTHDR)); 312 313 mt = m_tag_get(PACKET_TAG_NPF, sizeof(uint32_t), M_NOWAIT); 314 if (mt == NULL) { 315 return ENOMEM; 316 } 317 dat = (uint32_t *)(mt + 1); 318 *dat = val; 319 m_tag_prepend(m, mt); 320 return 0; 321 #else 322 (void)nbuf; (void)val; 323 return ENOTSUP; 324 #endif 325 } 326 327 /* 328 * nbuf_find_tag: find a tag in specified network buffer. 329 * 330 * => Returns 0 on success or errno on failure. 331 */ 332 int 333 nbuf_find_tag(nbuf_t *nbuf, uint32_t *val) 334 { 335 #ifdef _KERNEL 336 struct mbuf *m = nbuf->nb_mbuf0; 337 struct m_tag *mt; 338 339 KASSERT(m_flags_p(m, M_PKTHDR)); 340 341 mt = m_tag_find(m, PACKET_TAG_NPF); 342 if (mt == NULL) { 343 return EINVAL; 344 } 345 *val = *(uint32_t *)(mt + 1); 346 return 0; 347 #else 348 (void)nbuf; (void)val; 349 return ENOTSUP; 350 #endif 351 } 352