link_proto.c revision 1.3
1 /* $NetBSD: link_proto.c,v 1.3 2007/08/30 02:17:35 dyoung Exp $ */ 2 3 /*- 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)uipc_proto.c 8.2 (Berkeley) 2/14/95 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: link_proto.c,v 1.3 2007/08/30 02:17:35 dyoung Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/socket.h> 39 #include <sys/protosw.h> 40 #include <sys/domain.h> 41 #include <sys/mbuf.h> 42 #include <sys/un.h> 43 #include <sys/socketvar.h> 44 45 #include <net/if.h> 46 #include <net/if_dl.h> 47 #include <net/raw_cb.h> 48 49 static int sockaddr_dl_cmp(const struct sockaddr *, const struct sockaddr *); 50 51 /* 52 * Definitions of protocols supported in the link-layer domain. 53 */ 54 55 DOMAIN_DEFINE(linkdomain); /* forward define and add to link set */ 56 57 struct domain linkdomain = { 58 .dom_family = AF_LINK, 59 .dom_name = "link", 60 .dom_externalize = NULL, 61 .dom_dispose = NULL, 62 .dom_protosw = NULL, 63 .dom_protoswNPROTOSW = NULL, 64 .dom_sockaddr_cmp = sockaddr_dl_cmp 65 }; 66 67 /* Compare the field at byte offsets [fieldstart, fieldend) in 68 * two memory regions, [l, l + llen) and [r, r + llen). 69 */ 70 static inline int 71 submemcmp(const void *l, const void *r, 72 const uint_fast8_t llen, const uint_fast8_t rlen, 73 const uint_fast8_t fieldstart, const uint_fast8_t fieldend) 74 { 75 uint_fast8_t cmpend, minlen; 76 const uint8_t *lb = l, *rb = r; 77 int rc; 78 79 minlen = MIN(llen, rlen); 80 81 /* The field is missing from one region. The shorter region is the 82 * lesser region. 83 */ 84 if (fieldstart >= minlen) 85 return llen - rlen; 86 87 /* Two empty, present fields are always equal. */ 88 if (fieldstart > fieldend) 89 return 0; 90 91 cmpend = MIN(fieldend, minlen); 92 93 rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart); 94 95 if (rc != 0) 96 return rc; 97 /* If one or both fields are truncated, then the shorter is the lesser 98 * field. 99 */ 100 if (minlen < fieldend) 101 return llen - rlen; 102 /* Fields are full-length and equal. The fields are equal. */ 103 return 0; 104 } 105 106 uint8_t 107 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen) 108 { 109 return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]); 110 } 111 112 struct sockaddr * 113 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type, 114 const void *name, uint8_t namelen, const void *addr, uint8_t addrlen, 115 int flags) 116 { 117 struct sockaddr *sa; 118 socklen_t len; 119 120 len = sockaddr_dl_measure(namelen, addrlen); 121 sa = sockaddr_alloc(AF_LINK, len, flags); 122 123 if (sa == NULL) 124 return NULL; 125 126 if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen, 127 addr, addrlen) == NULL) { 128 sockaddr_free(sa); 129 return NULL; 130 } 131 132 return sa; 133 } 134 135 struct sockaddr_dl * 136 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex, 137 uint8_t type, const void *name, uint8_t namelen, const void *addr, 138 uint8_t addrlen) 139 { 140 socklen_t len; 141 142 sdl->sdl_family = AF_LINK; 143 sdl->sdl_slen = 0; 144 len = sockaddr_dl_measure(namelen, addrlen); 145 if (len > socklen) { 146 sdl->sdl_len = socklen; 147 #ifdef DIAGNOSTIC 148 printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len, 149 socklen); 150 #endif 151 return NULL; 152 } 153 sdl->sdl_len = len; 154 sdl->sdl_index = ifindex; 155 sdl->sdl_type = type; 156 memset(&sdl->sdl_data[0], 0, namelen + addrlen); 157 if (name != NULL) { 158 memcpy(&sdl->sdl_data[0], name, namelen); 159 sdl->sdl_nlen = namelen; 160 } else 161 sdl->sdl_nlen = 0; 162 if (addr != NULL) { 163 memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen); 164 sdl->sdl_alen = addrlen; 165 } else 166 sdl->sdl_alen = 0; 167 return sdl; 168 } 169 170 static int 171 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2) 172 { 173 int rc; 174 const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index); 175 const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen); 176 uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]); 177 const struct sockaddr_dl *sdl1, *sdl2; 178 179 sdl1 = satocsdl(sa1); 180 sdl2 = satocsdl(sa2); 181 182 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 183 indexofs, nlenofs); 184 185 if (rc != 0) 186 return rc; 187 188 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 189 dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen)); 190 191 if (rc != 0) 192 return rc; 193 194 if (sdl1->sdl_nlen != sdl2->sdl_nlen) 195 return sdl1->sdl_nlen - sdl2->sdl_nlen; 196 197 dataofs += sdl1->sdl_nlen; 198 199 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 200 dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen)); 201 202 if (rc != 0) 203 return rc; 204 205 if (sdl1->sdl_alen != sdl2->sdl_alen) 206 return sdl1->sdl_alen - sdl2->sdl_alen; 207 208 dataofs += sdl1->sdl_alen; 209 210 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 211 dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen)); 212 213 if (sdl1->sdl_slen != sdl2->sdl_slen) 214 return sdl1->sdl_slen - sdl2->sdl_slen; 215 216 return sdl1->sdl_len - sdl2->sdl_len; 217 } 218 219 struct sockaddr_dl * 220 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen, 221 const void *addr, uint8_t addrlen) 222 { 223 socklen_t len; 224 225 len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen); 226 if (len > socklen) { 227 #ifdef DIAGNOSTIC 228 printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len, 229 socklen); 230 #endif 231 return NULL; 232 } 233 memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen); 234 sdl->sdl_alen = addrlen; 235 sdl->sdl_len = len; 236 return sdl; 237 } 238
Indexes created Sat Sep 27 14:09:57 GMT 2025