1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 /* 31 * University Copyright- Copyright (c) 1982, 1986, 1988 32 * The Regents of the University of California 33 * All Rights Reserved 34 * 35 * University Acknowledgment- Portions of this document are derived from 36 * software developed by the University of California, Berkeley, and its 37 * contributors. 38 */ 39 40 #pragma ident "%Z%%M% %I% %E% SMI" 41 42 /* 43 * All routines necessary to deal the "ethers" database. The sources 44 * contain mappings between 48 bit ethernet addresses and corresponding 45 * hosts names. The addresses have an ascii representation of the form 46 * "x:x:x:x:x:x" where x is a hex number between 0x00 and 0xff; the 47 * bytes are always in network order. 48 */ 49 50 #include <stdio.h> 51 #include <ctype.h> 52 #include <string.h> 53 #include <stdlib.h> 54 #include <sys/types.h> 55 #include <thread.h> 56 #include <pthread.h> 57 #include <sys/socket.h> 58 #include <net/if.h> 59 #include <netinet/in.h> 60 #include <netinet/if_ether.h> 61 #include <nss_dbdefs.h> 62 63 int str2ether(const char *, int, void *, char *, int); 64 65 static DEFINE_NSS_DB_ROOT(db_root); 66 67 void 68 _nss_initf_ethers(nss_db_params_t *p) 69 { 70 p->name = NSS_DBNAM_ETHERS; 71 p->default_config = NSS_DEFCONF_ETHERS; 72 } 73 74 /* 75 * Given a host's name, this routine finds the corresponding 48 bit 76 * ethernet address based on the "ethers" policy in /etc/nsswitch.conf. 77 * Returns zero if successful, non-zero otherwise. 78 */ 79 int 80 ether_hostton( 81 const char *host, /* function input */ 82 struct ether_addr *e /* function output */ 83 ) 84 { 85 nss_XbyY_args_t arg; 86 nss_status_t res; 87 88 /* 89 * let the backend do the allocation to store stuff for parsing. 90 */ 91 NSS_XbyY_INIT(&arg, e, NULL, 0, str2ether); 92 arg.key.name = host; 93 res = nss_search(&db_root, _nss_initf_ethers, 94 NSS_DBOP_ETHERS_HOSTTON, &arg); 95 (void) NSS_XbyY_FINI(&arg); 96 return (arg.status = res); 97 } 98 99 /* 100 * Given a 48 bit ethernet address, it finds the corresponding hostname 101 * ethernet address based on the "ethers" policy in /etc/nsswitch.conf. 102 * Returns zero if successful, non-zero otherwise. 103 */ 104 int 105 ether_ntohost( 106 char *host, /* function output */ 107 const struct ether_addr *e /* function input */ 108 ) 109 { 110 nss_XbyY_args_t arg; 111 nss_status_t res; 112 113 /* 114 * let the backend do the allocation to store stuff for parsing. 115 */ 116 NSS_XbyY_INIT(&arg, NULL, host, 0, str2ether); 117 arg.key.ether = (void *)e; 118 res = nss_search(&db_root, _nss_initf_ethers, 119 NSS_DBOP_ETHERS_NTOHOST, &arg); 120 /* memcpy(host, ether_res.host, strlen(ether_res.host)); */ 121 (void) NSS_XbyY_FINI(&arg); 122 return (arg.status = res); 123 } 124 125 /* 126 * Parses a line from "ethers" database into its components. The line has 127 * the form 8:0:20:1:17:c8 krypton 128 * where the first part is a 48 bit ethernet address and the second is 129 * the corresponding hosts name. 130 * Returns zero if successful, non-zero otherwise. 131 */ 132 int 133 ether_line( 134 const char *s, /* the string to be parsed */ 135 struct ether_addr *e, /* ethernet address struct to be filled in */ 136 char *hostname /* hosts name to be set */ 137 ) 138 { 139 int i; 140 uint_t t[6]; 141 142 i = sscanf(s, " %x:%x:%x:%x:%x:%x %s", 143 &t[0], &t[1], &t[2], &t[3], &t[4], &t[5], hostname); 144 if (i != 7) { 145 return (7 - i); 146 } 147 for (i = 0; i < 6; i++) 148 e->ether_addr_octet[i] = (uchar_t)t[i]; 149 return (0); 150 } 151 152 /* 153 * Parses a line from "ethers" database into its components. 154 * Useful for the vile purposes of the backends that 155 * expect a str2ether() format. 156 * 157 * This function, after parsing the instr line, will 158 * place the resulting struct ether_addr in b->buf.result only if 159 * b->buf.result is initialized (not NULL). I.e. it always happens 160 * for "files" backend (that needs to parse input line and 161 * then do a match for the ether key) and happens for "nis" 162 * backend only if the call was ether_hostton. 163 * 164 * Also, it will place the resulting hostname into b->buf.buffer 165 * only if b->buf.buffer is initialized. I.e. it always happens 166 * for "files" backend (that needs to parse input line and 167 * then do a match for the host key) and happens for "nis" 168 * backend only if the call was ether_ntohost. 169 * 170 * Cannot use the sscanf() technique for parsing because instr 171 * is a read-only, not necessarily null-terminated, buffer. 172 * 173 * Return values: 0 = success, 1 = parse error, 2 = erange ... 174 * The structure pointer passed in is a structure in the caller's space 175 * wherein the field pointers would be set to areas in the buffer if 176 * need be. instring and buffer should be separate areas. 177 */ 178 #define DIGIT(x) (isdigit(x) ? (x) - '0' : \ 179 islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A') 180 #define lisalnum(x) (isdigit(x) || \ 181 ((x) >= 'a' && (x) <= 'z') || ((x) >= 'A' && (x) <= 'Z')) 182 /* ARGSUSED */ 183 int 184 str2ether(const char *instr, int lenstr, void *ent, char *buffer, int buflen) 185 { 186 uchar_t *ether = (uchar_t *)ent; 187 char *host = buffer; 188 const char *p, *limit, *start; 189 ptrdiff_t i; 190 191 p = instr; 192 limit = p + lenstr; 193 194 /* skip beginning whitespace, if any */ 195 while (p < limit && isspace(*p)) 196 p++; 197 198 if (ether) { /* parse ether */ 199 for (i = 0; i < 6; i++) { 200 int j = 0, n = 0; 201 202 start = p; 203 while (p < limit && lisalnum(start[j])) { 204 /* don't worry about overflow here */ 205 n = 16 * n + DIGIT(start[j]); 206 j++; 207 p++; 208 } 209 if (*p != ':' && i < 5) { 210 return (NSS_STR_PARSE_PARSE); 211 } else { 212 p++; 213 *(ether + i) = (uchar_t)n; 214 } 215 } 216 } else { /* skip ether */ 217 while (p < limit && !isspace(*p)) 218 p++; 219 } 220 if (host) { /* parse host */ 221 while (p < limit && isspace(*p)) /* skip whitespace */ 222 p++; 223 start = p; 224 while (p < limit && !isspace(*p)) /* skip hostname */ 225 p++; 226 if ((i = (p - start)) < MAXHOSTNAMELEN) { 227 (void) memcpy(host, start, i); 228 host[i] = '\0'; 229 } else 230 return (NSS_STR_PARSE_ERANGE); /* failure */ 231 } 232 return (NSS_STR_PARSE_SUCCESS); 233 } 234 235 typedef struct { 236 char ea_string[18]; 237 struct ether_addr ea_addr; 238 } eabuf_t; 239 240 static eabuf_t * 241 ea_buf(void) 242 { 243 static thread_key_t key = THR_ONCE_KEY; 244 static eabuf_t ea_main; 245 eabuf_t *eabuf; 246 247 if (thr_main()) 248 return (&ea_main); 249 250 if (thr_keycreate_once(&key, free) != 0) 251 return (NULL); 252 eabuf = pthread_getspecific(key); 253 if (eabuf == NULL) { 254 eabuf = malloc(sizeof (eabuf_t)); 255 (void) thr_setspecific(key, eabuf); 256 } 257 return (eabuf); 258 } 259 260 /* 261 * Converts a 48 bit ethernet number to its string representation. 262 */ 263 char * 264 ether_ntoa(const struct ether_addr *e) 265 { 266 eabuf_t *eabuf; 267 char *s; 268 269 if ((eabuf = ea_buf()) == NULL) 270 return (NULL); 271 s = eabuf->ea_string; 272 (void) sprintf(s, "%x:%x:%x:%x:%x:%x", 273 e->ether_addr_octet[0], e->ether_addr_octet[1], 274 e->ether_addr_octet[2], e->ether_addr_octet[3], 275 e->ether_addr_octet[4], e->ether_addr_octet[5]); 276 return (s); 277 } 278 279 /* 280 * Converts an ethernet address representation back into its 48 bits. 281 */ 282 struct ether_addr * 283 ether_aton(const char *s) 284 { 285 eabuf_t *eabuf; 286 struct ether_addr *e; 287 int i; 288 uint_t t[6]; 289 290 if ((eabuf = ea_buf()) == NULL) 291 return (NULL); 292 e = &eabuf->ea_addr; 293 i = sscanf(s, " %x:%x:%x:%x:%x:%x", 294 &t[0], &t[1], &t[2], &t[3], &t[4], &t[5]); 295 if (i != 6) 296 return (NULL); 297 for (i = 0; i < 6; i++) 298 e->ether_addr_octet[i] = (uchar_t)t[i]; 299 return (e); 300 } 301