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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 1985-1999 by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" /* SMI4.1 1.7 */ 28 29 #include <stdio.h> 30 #include <ndbm.h> 31 #include <netdb.h> 32 #include <sys/types.h> 33 #include <sys/socket.h> 34 #include <netinet/in.h> 35 #include <arpa/inet.h> 36 #include <string.h> 37 #include <ctype.h> 38 #include <errno.h> 39 40 /* 41 * Filter to convert both IPv4 and IPv6 addresses from /etc/hosts or 42 * /etc/inet/ipnodes files. 43 */ 44 45 /* 46 * Size of buffer for input lines. Add two bytes on input for newline 47 * and terminating NULL. Note that the practical limit for data 48 * storage in ndbm is (PBLKSIZ - 3 * sizeof (short)). Though this 49 * differs from spec 1170 the common industry implementation does 50 * conform to this slightly lower limit. 51 */ 52 53 #define OUTPUTSIZ (PBLKSIZ - 3 * sizeof (short)) 54 #define INPUTSIZ (OUTPUTSIZ + 2) 55 56 static int ipv4 = -1; 57 static char *cmd; 58 int warn = 0; 59 60 static void verify_and_output(const char *key, char *value, int lineno); 61 62 void 63 usage() 64 { 65 fprintf(stderr, "stdhosts [-w] [-n] [in-file]\n"); 66 fprintf(stderr, "\t-w\tprint malformed warning messages.\n"); 67 exit(1); 68 } 69 70 main(argc, argv) 71 char **argv; 72 { 73 char line[INPUTSIZ]; 74 char adr[INPUTSIZ]; 75 char nadr[INET6_ADDRSTRLEN]; /* Contains normalised address */ 76 const char *nadrp; /* Pointer to the normalised address */ 77 char *trailer; 78 char *commentp; /* Pointer to comment character '#' */ 79 int c; 80 FILE *fp; 81 int lineno = 0; /* Input line counter */ 82 struct in_addr in; /* Used for normalising the IPv4 address */ 83 struct in6_addr in6; /* Used for normalising the IPv6 address */ 84 char *fgetsp; /* Holds return value for fgets() calls */ 85 int endoffile = 0; /* Set when end of file reached */ 86 87 if (cmd = strrchr(argv[0], '/')) 88 ++cmd; 89 else 90 cmd = argv[0]; 91 92 while ((c = getopt(argc, argv, "v:wn")) != -1) { 93 switch (c) { 94 case 'w': /* Send warning messages to stderr */ 95 warn = 1; 96 break; 97 case 'n': 98 ipv4 = 0; 99 break; 100 default: 101 usage(); 102 exit(1); 103 } 104 } 105 106 if (optind < argc) { 107 fp = fopen(argv[optind], "r"); 108 if (fp == NULL) { 109 fprintf(stderr, "%s: can't open %s\n", 110 cmd, argv[optind]); 111 exit(1); 112 } 113 } else 114 fp = stdin; 115 116 while (!endoffile && 117 (fgetsp = fgets(line, sizeof (line), fp)) != NULL) { 118 lineno++; 119 120 /* Check for comments */ 121 if ((commentp = strchr(line, '#')) != NULL) { 122 if ((line[strlen(line) - 1] != '\n') && 123 (strlen(line) >= (sizeof (line) - 1))) { 124 /* 125 * Discard the remainder of the line 126 * until the newline or EOF, then 127 * continue to parse the line. Use 128 * adr[] rather then line[] to 129 * preserve the contents of line[]. 130 */ 131 while ((fgetsp = fgets(adr, sizeof (adr), 132 fp)) != NULL) { 133 if (adr[strlen(adr) - 1] == '\n') 134 break; 135 } 136 if (fgetsp == NULL) 137 endoffile = 1; 138 } 139 /* Terminate line[] at the comment character */ 140 *commentp = '\0'; 141 } else if ((line[strlen(line) - 1] != '\n') && 142 (strlen(line) >= (sizeof (line) - 1))) { 143 /* 144 * Catch long lines but not if this is a short 145 * line with no '\n' at the end of the input. 146 */ 147 if (warn) 148 fprintf(stderr, 149 "%s: Warning: more than %d " 150 "bytes on line %d, ignored\n", 151 cmd, sizeof (line) - 2, lineno); 152 /* 153 * Discard the remaining lines until the 154 * newline or EOF. 155 */ 156 while ((fgetsp = fgets(line, sizeof (line), 157 fp)) != NULL) 158 if (line[strlen(line) - 1] == '\n') 159 break; 160 if (fgetsp == NULL) 161 endoffile = 1; 162 continue; 163 } 164 165 if (sscanf(line, "%s", adr) != 1) { /* Blank line, ignore */ 166 continue; 167 } 168 169 if ((trailer = strpbrk(line, " \t")) == NULL) { 170 if (warn) 171 fprintf(stderr, 172 "%s: Warning: no host names on line %d, " 173 "ignored\n", cmd, lineno); 174 continue; 175 } 176 177 /* 178 * check for valid addresses 179 * 180 * Attempt an ipv4 conversion, this accepts all valid 181 * ipv4 addresses including: 182 * d 183 * d.d 184 * d.d.d 185 * Unfortunately inet_pton() doesn't recognise these. 186 */ 187 188 in.s_addr = inet_addr(adr); 189 if (-1 != (int)in.s_addr) { 190 /* 191 * It's safe not to check return of NULL as 192 * nadrp is checked for validity later. 193 */ 194 nadrp = inet_ntop(AF_INET, &in, nadr, sizeof (nadr)); 195 } else { 196 nadrp = NULL; /* Not a valid IPv4 address */ 197 } 198 199 if (ipv4) { 200 if (nadrp == NULL) { 201 if (warn) 202 fprintf(stderr, 203 "%s: Warning: malformed address on" 204 " line %d, ignored\n", 205 cmd, lineno); 206 continue; 207 } 208 } else { /* v4 or v6 for ipnodes */ 209 if (nadrp == NULL) { 210 if (inet_pton(AF_INET6, adr, &in6) == 1) { 211 nadrp = inet_ntop(AF_INET6, &in6, 212 nadr, sizeof (nadr)); 213 } 214 if (nadrp == NULL) { /* Invalid IPv6 too */ 215 if (warn) 216 fprintf(stderr, 217 "%s: Warning: malformed" 218 " address on" 219 " line %d, ignored\n", 220 cmd, lineno); 221 continue; 222 } 223 } 224 } 225 226 verify_and_output(nadrp, trailer, lineno); 227 228 } /* while */ 229 exit(0); 230 /* NOTREACHED */ 231 } 232 233 /* 234 * verify_and_output 235 * 236 * Builds and verifies the output key and value string 237 * 238 * It makes sure these rules are followed: 239 * key + separator + value <= OUTPUTSIZ (for ndbm) 240 * names <= MAXALIASES + 1, ie one canonical name + MAXALIASES aliases 241 * It will also ignore everything after a '#' comment character 242 */ 243 static void 244 verify_and_output(const char *key, char *value, int lineno) 245 { 246 char *p; /* General char pointer */ 247 char *endp; /* Points to the NULL at the end */ 248 char *namep; /* First character of a name */ 249 char tmpbuf[OUTPUTSIZ+1]; /* Buffer before writing out */ 250 char *tmpbufp = tmpbuf; /* Current point in output string */ 251 int n = 0; /* Length of output */ 252 int names = 0; /* Number of names found */ 253 int namelen; /* Length of the name */ 254 255 if (key) { /* Just in case key is NULL */ 256 n = strlen(key); 257 if (n > OUTPUTSIZ) { 258 if (warn) 259 fprintf(stderr, 260 "%s: address too long on " 261 "line %d, line discarded\n", 262 cmd, lineno); 263 return; 264 } 265 memcpy(tmpbufp, key, n+1); /* Plus the '\0' */ 266 tmpbufp += n; 267 } 268 269 if (value) { /* Just in case value is NULL */ 270 p = value; 271 if ((endp = strchr(value, '#')) == 0) /* Ignore # comments */ 272 endp = p + strlen(p); /* Or endp = EOL */ 273 do { 274 /* 275 * Skip white space. Type conversion is 276 * necessary to avoid unfortunate effects of 277 * 8-bit characters appearing negative. 278 */ 279 while ((p < endp) && isspace((unsigned char)*p)) 280 p++; 281 282 if (p == endp) /* End of the string */ 283 break; 284 285 names++; 286 if (names > (MAXALIASES+1)) { /* cname + MAXALIASES */ 287 if (warn) 288 fprintf(stderr, 289 "%s: Warning: too many " 290 "host names on line %d, " 291 "truncating\n", 292 cmd, lineno); 293 break; 294 } 295 296 namep = p; 297 while ((p < endp) && !isspace((unsigned char)*p)) 298 p++; 299 300 namelen = p - namep; 301 n += namelen + 1; /* single white space + name */ 302 *p = '\0'; /* Terminate the name string */ 303 if (n > OUTPUTSIZ) { 304 if (warn) 305 fprintf(stderr, 306 "%s: Warning: %d byte ndbm limit " 307 "reached on line %d, truncating\n", 308 cmd, OUTPUTSIZ, lineno); 309 break; 310 } 311 312 if (names == 1) /* First space is a '\t' */ 313 *tmpbufp++ = '\t'; 314 else 315 *tmpbufp++ = ' '; 316 317 memcpy(tmpbufp, namep, namelen+1); /* Plus the '\0' */ 318 tmpbufp += namelen; 319 320 if (p < endp) 321 p++; /* Skip the added NULL */ 322 323 } while (p < endp); 324 } 325 326 if (names > 0) { 327 fputs(tmpbuf, stdout); 328 fputc('\n', stdout); 329 } else { 330 if (warn) 331 fprintf(stderr, 332 "%s: Warning: no host names on line %d, " 333 "ignored\n", cmd, lineno); 334 } 335 } 336