xref: /illumos-gate/usr/src/cmd/ypcmd/stdhosts.c (revision d362b749)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
527092493Srs  * Common Development and Distribution License (the "License").
627092493Srs  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
217c478bd9Sstevel@tonic-gate /*
22*d362b749Svk  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23a506a34cSth  * Use is subject to license terms.
247c478bd9Sstevel@tonic-gate  */
257c478bd9Sstevel@tonic-gate 
267c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"	/* SMI4.1 1.7  */
277c478bd9Sstevel@tonic-gate 
287c478bd9Sstevel@tonic-gate #include <stdio.h>
297c478bd9Sstevel@tonic-gate #include <ndbm.h>
307c478bd9Sstevel@tonic-gate #include <netdb.h>
317c478bd9Sstevel@tonic-gate #include <sys/types.h>
327c478bd9Sstevel@tonic-gate #include <sys/socket.h>
337c478bd9Sstevel@tonic-gate #include <netinet/in.h>
347c478bd9Sstevel@tonic-gate #include <arpa/inet.h>
357c478bd9Sstevel@tonic-gate #include <string.h>
367c478bd9Sstevel@tonic-gate #include <ctype.h>
377c478bd9Sstevel@tonic-gate #include <errno.h>
387c478bd9Sstevel@tonic-gate 
397c478bd9Sstevel@tonic-gate /*
4027092493Srs  * Filter to convert both IPv4 and IPv6 addresses from /etc/hosts file.
417c478bd9Sstevel@tonic-gate  */
427c478bd9Sstevel@tonic-gate 
437c478bd9Sstevel@tonic-gate /*
447c478bd9Sstevel@tonic-gate  * Size of buffer for input lines. Add two bytes on input for newline
457c478bd9Sstevel@tonic-gate  * and terminating NULL. Note that the practical limit for data
467c478bd9Sstevel@tonic-gate  * storage in ndbm is (PBLKSIZ - 3 * sizeof (short)). Though this
477c478bd9Sstevel@tonic-gate  * differs from spec 1170 the common industry implementation does
487c478bd9Sstevel@tonic-gate  * conform to this slightly lower limit.
497c478bd9Sstevel@tonic-gate  */
507c478bd9Sstevel@tonic-gate 
517c478bd9Sstevel@tonic-gate #define	OUTPUTSIZ (PBLKSIZ - 3 * sizeof (short))
527c478bd9Sstevel@tonic-gate #define	INPUTSIZ (OUTPUTSIZ + 2)
537c478bd9Sstevel@tonic-gate 
547c478bd9Sstevel@tonic-gate static int ipv4 = -1;
557c478bd9Sstevel@tonic-gate static char *cmd;
56*d362b749Svk int warning = 0;
577c478bd9Sstevel@tonic-gate 
587c478bd9Sstevel@tonic-gate static void verify_and_output(const char *key, char *value, int lineno);
597c478bd9Sstevel@tonic-gate 
607c478bd9Sstevel@tonic-gate void
usage()617c478bd9Sstevel@tonic-gate usage()
627c478bd9Sstevel@tonic-gate {
637c478bd9Sstevel@tonic-gate 	fprintf(stderr, "stdhosts [-w] [-n] [in-file]\n");
647c478bd9Sstevel@tonic-gate 	fprintf(stderr, "\t-w\tprint malformed warning messages.\n");
657c478bd9Sstevel@tonic-gate 	exit(1);
667c478bd9Sstevel@tonic-gate }
677c478bd9Sstevel@tonic-gate 
68a506a34cSth int
main(argc,argv)697c478bd9Sstevel@tonic-gate main(argc, argv)
707c478bd9Sstevel@tonic-gate 	char **argv;
717c478bd9Sstevel@tonic-gate {
727c478bd9Sstevel@tonic-gate 	char line[INPUTSIZ];
737c478bd9Sstevel@tonic-gate 	char adr[INPUTSIZ];
747c478bd9Sstevel@tonic-gate 	char nadr[INET6_ADDRSTRLEN]; /* Contains normalised address */
757c478bd9Sstevel@tonic-gate 	const char *nadrp;	/* Pointer to the normalised address */
767c478bd9Sstevel@tonic-gate 	char *trailer;
777c478bd9Sstevel@tonic-gate 	char *commentp;		/* Pointer to comment character '#' */
787c478bd9Sstevel@tonic-gate 	int c;
797c478bd9Sstevel@tonic-gate 	FILE *fp;
807c478bd9Sstevel@tonic-gate 	int lineno = 0;		/* Input line counter */
817c478bd9Sstevel@tonic-gate 	struct in_addr in;	/* Used for normalising the IPv4 address */
827c478bd9Sstevel@tonic-gate 	struct in6_addr in6;	/* Used for normalising the IPv6 address */
837c478bd9Sstevel@tonic-gate 	char *fgetsp;		/* Holds return value for fgets() calls */
847c478bd9Sstevel@tonic-gate 	int endoffile = 0;	/* Set when end of file reached */
857c478bd9Sstevel@tonic-gate 
867c478bd9Sstevel@tonic-gate 	if (cmd = strrchr(argv[0], '/'))
877c478bd9Sstevel@tonic-gate 		++cmd;
887c478bd9Sstevel@tonic-gate 	else
897c478bd9Sstevel@tonic-gate 		cmd = argv[0];
907c478bd9Sstevel@tonic-gate 
917c478bd9Sstevel@tonic-gate 	while ((c = getopt(argc, argv, "v:wn")) != -1) {
927c478bd9Sstevel@tonic-gate 		switch (c) {
937c478bd9Sstevel@tonic-gate 		case 'w':	/* Send warning messages to stderr */
94*d362b749Svk 			warning = 1;
957c478bd9Sstevel@tonic-gate 			break;
967c478bd9Sstevel@tonic-gate 		case 'n':
977c478bd9Sstevel@tonic-gate 			ipv4 = 0;
987c478bd9Sstevel@tonic-gate 			break;
997c478bd9Sstevel@tonic-gate 		default:
1007c478bd9Sstevel@tonic-gate 			usage();
1017c478bd9Sstevel@tonic-gate 			exit(1);
1027c478bd9Sstevel@tonic-gate 		}
1037c478bd9Sstevel@tonic-gate 	}
1047c478bd9Sstevel@tonic-gate 
1057c478bd9Sstevel@tonic-gate 	if (optind < argc) {
1067c478bd9Sstevel@tonic-gate 		fp = fopen(argv[optind], "r");
1077c478bd9Sstevel@tonic-gate 		if (fp == NULL) {
1087c478bd9Sstevel@tonic-gate 			fprintf(stderr, "%s: can't open %s\n",
1097c478bd9Sstevel@tonic-gate 			    cmd, argv[optind]);
1107c478bd9Sstevel@tonic-gate 			exit(1);
1117c478bd9Sstevel@tonic-gate 		}
1127c478bd9Sstevel@tonic-gate 	} else
1137c478bd9Sstevel@tonic-gate 		fp = stdin;
1147c478bd9Sstevel@tonic-gate 
1157c478bd9Sstevel@tonic-gate 	while (!endoffile &&
1167c478bd9Sstevel@tonic-gate 	    (fgetsp = fgets(line, sizeof (line), fp)) != NULL) {
1177c478bd9Sstevel@tonic-gate 		lineno++;
1187c478bd9Sstevel@tonic-gate 
1197c478bd9Sstevel@tonic-gate 		/* Check for comments */
1207c478bd9Sstevel@tonic-gate 		if ((commentp = strchr(line, '#')) != NULL) {
1217c478bd9Sstevel@tonic-gate 			if ((line[strlen(line) - 1] != '\n') &&
1227c478bd9Sstevel@tonic-gate 			    (strlen(line) >= (sizeof (line) - 1))) {
1237c478bd9Sstevel@tonic-gate 				/*
1247c478bd9Sstevel@tonic-gate 				 * Discard the remainder of the line
1257c478bd9Sstevel@tonic-gate 				 * until the newline or EOF, then
1267c478bd9Sstevel@tonic-gate 				 * continue to parse the line. Use
1277c478bd9Sstevel@tonic-gate 				 * adr[] rather then line[] to
1287c478bd9Sstevel@tonic-gate 				 * preserve the contents of line[].
1297c478bd9Sstevel@tonic-gate 				 */
1307c478bd9Sstevel@tonic-gate 				while ((fgetsp = fgets(adr, sizeof (adr),
1317c478bd9Sstevel@tonic-gate 				    fp)) != NULL) {
1327c478bd9Sstevel@tonic-gate 					if (adr[strlen(adr) - 1] == '\n')
1337c478bd9Sstevel@tonic-gate 						break;
1347c478bd9Sstevel@tonic-gate 				}
1357c478bd9Sstevel@tonic-gate 				if (fgetsp == NULL)
1367c478bd9Sstevel@tonic-gate 					endoffile = 1;
1377c478bd9Sstevel@tonic-gate 			}
1387c478bd9Sstevel@tonic-gate 			/* Terminate line[] at the comment character */
1397c478bd9Sstevel@tonic-gate 			*commentp = '\0';
1407c478bd9Sstevel@tonic-gate 		} else if ((line[strlen(line) - 1] != '\n') &&
1417c478bd9Sstevel@tonic-gate 		    (strlen(line) >= (sizeof (line) - 1))) {
1427c478bd9Sstevel@tonic-gate 			/*
1437c478bd9Sstevel@tonic-gate 			 * Catch long lines but not if this is a short
1447c478bd9Sstevel@tonic-gate 			 * line with no '\n' at the end of the input.
1457c478bd9Sstevel@tonic-gate 			 */
146*d362b749Svk 			if (warning)
1477c478bd9Sstevel@tonic-gate 				fprintf(stderr,
1487c478bd9Sstevel@tonic-gate 				    "%s: Warning: more than %d "
1497c478bd9Sstevel@tonic-gate 				    "bytes on line %d, ignored\n",
1507c478bd9Sstevel@tonic-gate 				    cmd, sizeof (line) - 2, lineno);
1517c478bd9Sstevel@tonic-gate 			/*
1527c478bd9Sstevel@tonic-gate 			 * Discard the remaining lines until the
1537c478bd9Sstevel@tonic-gate 			 * newline or EOF.
1547c478bd9Sstevel@tonic-gate 			 */
1557c478bd9Sstevel@tonic-gate 			while ((fgetsp = fgets(line, sizeof (line),
1567c478bd9Sstevel@tonic-gate 			    fp)) != NULL)
1577c478bd9Sstevel@tonic-gate 				if (line[strlen(line) - 1] == '\n')
1587c478bd9Sstevel@tonic-gate 					break;
1597c478bd9Sstevel@tonic-gate 			if (fgetsp == NULL)
1607c478bd9Sstevel@tonic-gate 				endoffile = 1;
1617c478bd9Sstevel@tonic-gate 			continue;
1627c478bd9Sstevel@tonic-gate 		}
1637c478bd9Sstevel@tonic-gate 
1647c478bd9Sstevel@tonic-gate 		if (sscanf(line, "%s", adr) != 1) { /* Blank line, ignore */
1657c478bd9Sstevel@tonic-gate 			continue;
1667c478bd9Sstevel@tonic-gate 		}
1677c478bd9Sstevel@tonic-gate 
1687c478bd9Sstevel@tonic-gate 		if ((trailer = strpbrk(line, " \t")) == NULL) {
169*d362b749Svk 			if (warning)
1707c478bd9Sstevel@tonic-gate 				fprintf(stderr,
1717c478bd9Sstevel@tonic-gate 				    "%s: Warning: no host names on line %d, "
1727c478bd9Sstevel@tonic-gate 				    "ignored\n", cmd, lineno);
1737c478bd9Sstevel@tonic-gate 			continue;
1747c478bd9Sstevel@tonic-gate 		}
1757c478bd9Sstevel@tonic-gate 
1767c478bd9Sstevel@tonic-gate 		/*
1777c478bd9Sstevel@tonic-gate 		 * check for valid addresses
1787c478bd9Sstevel@tonic-gate 		 *
1797c478bd9Sstevel@tonic-gate 		 * Attempt an ipv4 conversion, this accepts all valid
1807c478bd9Sstevel@tonic-gate 		 * ipv4 addresses including:
1817c478bd9Sstevel@tonic-gate 		 *	d
1827c478bd9Sstevel@tonic-gate 		 *	d.d
1837c478bd9Sstevel@tonic-gate 		 *	d.d.d
1847c478bd9Sstevel@tonic-gate 		 * Unfortunately inet_pton() doesn't recognise these.
1857c478bd9Sstevel@tonic-gate 		 */
1867c478bd9Sstevel@tonic-gate 
1877c478bd9Sstevel@tonic-gate 		in.s_addr = inet_addr(adr);
1887c478bd9Sstevel@tonic-gate 		if (-1 != (int)in.s_addr) {
1897c478bd9Sstevel@tonic-gate 			/*
1907c478bd9Sstevel@tonic-gate 			 * It's safe not to check return of NULL as
1917c478bd9Sstevel@tonic-gate 			 * nadrp is checked for validity later.
1927c478bd9Sstevel@tonic-gate 			 */
1937c478bd9Sstevel@tonic-gate 			nadrp = inet_ntop(AF_INET, &in, nadr, sizeof (nadr));
1947c478bd9Sstevel@tonic-gate 		} else {
1957c478bd9Sstevel@tonic-gate 			nadrp = NULL; /* Not a valid IPv4 address */
1967c478bd9Sstevel@tonic-gate 		}
1977c478bd9Sstevel@tonic-gate 
19827092493Srs 		if (nadrp == NULL) {
19927092493Srs 			if (inet_pton(AF_INET6, adr, &in6) == 1) {
20027092493Srs 				nadrp = inet_ntop(AF_INET6, &in6,
20127092493Srs 				    nadr, sizeof (nadr));
20227092493Srs 			}
20327092493Srs 			if (nadrp == NULL) { /* Invalid IPv6 too */
204*d362b749Svk 				if (warning)
2057c478bd9Sstevel@tonic-gate 					fprintf(stderr,
20627092493Srs 					    "%s: Warning: malformed"
20727092493Srs 					    " address on"
2087c478bd9Sstevel@tonic-gate 					    " line %d, ignored\n",
2097c478bd9Sstevel@tonic-gate 					    cmd, lineno);
2107c478bd9Sstevel@tonic-gate 				continue;
21127092493Srs 			} else if (ipv4) {
21227092493Srs 				continue; /* Ignore valid IPv6  */
2137c478bd9Sstevel@tonic-gate 			}
2147c478bd9Sstevel@tonic-gate 		}
2157c478bd9Sstevel@tonic-gate 
2167c478bd9Sstevel@tonic-gate 		verify_and_output(nadrp, trailer, lineno);
2177c478bd9Sstevel@tonic-gate 
2187c478bd9Sstevel@tonic-gate 	}	/* while */
219a506a34cSth 	return (0);
2207c478bd9Sstevel@tonic-gate 	/* NOTREACHED */
2217c478bd9Sstevel@tonic-gate }
2227c478bd9Sstevel@tonic-gate 
2237c478bd9Sstevel@tonic-gate /*
2247c478bd9Sstevel@tonic-gate  * verify_and_output
2257c478bd9Sstevel@tonic-gate  *
2267c478bd9Sstevel@tonic-gate  * Builds and verifies the output key and value string
2277c478bd9Sstevel@tonic-gate  *
2287c478bd9Sstevel@tonic-gate  * It makes sure these rules are followed:
2297c478bd9Sstevel@tonic-gate  *	key + separator + value <= OUTPUTSIZ (for ndbm)
2307c478bd9Sstevel@tonic-gate  *	names <= MAXALIASES + 1, ie one canonical name + MAXALIASES aliases
2317c478bd9Sstevel@tonic-gate  * It will also ignore everything after a '#' comment character
2327c478bd9Sstevel@tonic-gate  */
2337c478bd9Sstevel@tonic-gate static void
verify_and_output(const char * key,char * value,int lineno)2347c478bd9Sstevel@tonic-gate verify_and_output(const char *key, char *value, int lineno)
2357c478bd9Sstevel@tonic-gate {
2367c478bd9Sstevel@tonic-gate 	char *p;			/* General char pointer */
2377c478bd9Sstevel@tonic-gate 	char *endp;			/* Points to the NULL at the end */
2387c478bd9Sstevel@tonic-gate 	char *namep;			/* First character of a name */
2397c478bd9Sstevel@tonic-gate 	char tmpbuf[OUTPUTSIZ+1];	/* Buffer before writing out */
2407c478bd9Sstevel@tonic-gate 	char *tmpbufp = tmpbuf;		/* Current point in output string */
2417c478bd9Sstevel@tonic-gate 	int n = 0;			/* Length of output */
2427c478bd9Sstevel@tonic-gate 	int names = 0;			/* Number of names found */
2437c478bd9Sstevel@tonic-gate 	int namelen;			/* Length of the name */
2447c478bd9Sstevel@tonic-gate 
2457c478bd9Sstevel@tonic-gate 	if (key) {		/* Just in case key is NULL */
2467c478bd9Sstevel@tonic-gate 		n = strlen(key);
2477c478bd9Sstevel@tonic-gate 		if (n > OUTPUTSIZ) {
248*d362b749Svk 			if (warning)
2497c478bd9Sstevel@tonic-gate 				fprintf(stderr,
2507c478bd9Sstevel@tonic-gate 				    "%s: address too long on "
2517c478bd9Sstevel@tonic-gate 				    "line %d, line discarded\n",
2527c478bd9Sstevel@tonic-gate 				    cmd, lineno);
2537c478bd9Sstevel@tonic-gate 			return;
2547c478bd9Sstevel@tonic-gate 		}
2557c478bd9Sstevel@tonic-gate 		memcpy(tmpbufp, key, n+1); /* Plus the '\0' */
2567c478bd9Sstevel@tonic-gate 		tmpbufp += n;
2577c478bd9Sstevel@tonic-gate 	}
2587c478bd9Sstevel@tonic-gate 
2597c478bd9Sstevel@tonic-gate 	if (value) {		/* Just in case value is NULL */
2607c478bd9Sstevel@tonic-gate 		p = value;
2617c478bd9Sstevel@tonic-gate 		if ((endp = strchr(value, '#')) == 0)	/* Ignore # comments */
2627c478bd9Sstevel@tonic-gate 			endp = p + strlen(p);		/* Or endp = EOL */
2637c478bd9Sstevel@tonic-gate 		do {
2647c478bd9Sstevel@tonic-gate 			/*
2657c478bd9Sstevel@tonic-gate 			 * Skip white space. Type conversion is
2667c478bd9Sstevel@tonic-gate 			 * necessary to avoid unfortunate effects of
2677c478bd9Sstevel@tonic-gate 			 * 8-bit characters appearing negative.
2687c478bd9Sstevel@tonic-gate 			 */
2697c478bd9Sstevel@tonic-gate 			while ((p < endp) && isspace((unsigned char)*p))
2707c478bd9Sstevel@tonic-gate 				p++;
2717c478bd9Sstevel@tonic-gate 
2727c478bd9Sstevel@tonic-gate 			if (p == endp)	/* End of the string */
2737c478bd9Sstevel@tonic-gate 				break;
2747c478bd9Sstevel@tonic-gate 
2757c478bd9Sstevel@tonic-gate 			names++;
2767c478bd9Sstevel@tonic-gate 			if (names > (MAXALIASES+1)) { /* cname + MAXALIASES */
277*d362b749Svk 				if (warning)
2787c478bd9Sstevel@tonic-gate 					fprintf(stderr,
2797c478bd9Sstevel@tonic-gate 					    "%s: Warning: too many "
2807c478bd9Sstevel@tonic-gate 					    "host names on line %d, "
2817c478bd9Sstevel@tonic-gate 					    "truncating\n",
2827c478bd9Sstevel@tonic-gate 					    cmd, lineno);
2837c478bd9Sstevel@tonic-gate 				break;
2847c478bd9Sstevel@tonic-gate 			}
2857c478bd9Sstevel@tonic-gate 
2867c478bd9Sstevel@tonic-gate 			namep = p;
2877c478bd9Sstevel@tonic-gate 			while ((p < endp) && !isspace((unsigned char)*p))
2887c478bd9Sstevel@tonic-gate 				p++;
2897c478bd9Sstevel@tonic-gate 
2907c478bd9Sstevel@tonic-gate 			namelen = p - namep;
2917c478bd9Sstevel@tonic-gate 			n += namelen + 1; /* single white space + name */
2927c478bd9Sstevel@tonic-gate 			*p = '\0';	   /* Terminate the name string */
2937c478bd9Sstevel@tonic-gate 			if (n > OUTPUTSIZ) {
294*d362b749Svk 				if (warning)
2957c478bd9Sstevel@tonic-gate 					fprintf(stderr,
2967c478bd9Sstevel@tonic-gate 					    "%s: Warning: %d byte ndbm limit "
2977c478bd9Sstevel@tonic-gate 					    "reached on line %d, truncating\n",
2987c478bd9Sstevel@tonic-gate 					    cmd, OUTPUTSIZ, lineno);
2997c478bd9Sstevel@tonic-gate 				break;
3007c478bd9Sstevel@tonic-gate 			}
3017c478bd9Sstevel@tonic-gate 
3027c478bd9Sstevel@tonic-gate 			if (names == 1) /* First space is a '\t' */
3037c478bd9Sstevel@tonic-gate 				*tmpbufp++ = '\t';
3047c478bd9Sstevel@tonic-gate 			else
3057c478bd9Sstevel@tonic-gate 				*tmpbufp++ = ' ';
3067c478bd9Sstevel@tonic-gate 
3077c478bd9Sstevel@tonic-gate 			memcpy(tmpbufp, namep, namelen+1); /* Plus the '\0' */
3087c478bd9Sstevel@tonic-gate 			tmpbufp += namelen;
3097c478bd9Sstevel@tonic-gate 
3107c478bd9Sstevel@tonic-gate 			if (p < endp)
3117c478bd9Sstevel@tonic-gate 				p++;	/* Skip the added NULL */
3127c478bd9Sstevel@tonic-gate 
3137c478bd9Sstevel@tonic-gate 		} while (p < endp);
3147c478bd9Sstevel@tonic-gate 	}
3157c478bd9Sstevel@tonic-gate 
3167c478bd9Sstevel@tonic-gate 	if (names > 0) {
3177c478bd9Sstevel@tonic-gate 		fputs(tmpbuf, stdout);
3187c478bd9Sstevel@tonic-gate 		fputc('\n', stdout);
3197c478bd9Sstevel@tonic-gate 	} else {
320*d362b749Svk 		if (warning)
3217c478bd9Sstevel@tonic-gate 			fprintf(stderr,
3227c478bd9Sstevel@tonic-gate 			    "%s: Warning: no host names on line %d, "
3237c478bd9Sstevel@tonic-gate 			    "ignored\n", cmd, lineno);
3247c478bd9Sstevel@tonic-gate 	}
3257c478bd9Sstevel@tonic-gate }
326