/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


/*
 * mkmap - program to convert the mail.aliases map into an
 * inverse map of <user@host> back to <preferred-alias>
 */

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <ndbm.h>
#include <stdio.h>
#include <ctype.h>
#include <netdb.h>
#include <sys/systeminfo.h>

#include "ypdefs.h"
USE_YP_PREFIX
USE_YP_MASTER_NAME
USE_YP_LAST_MODIFIED

#define	MKAL_INCLUDE ":include:"

void CopyName(char *dst, char *src, int len);
int HostCheck(char *h, char *a);
void DoName(char *cp);
void UpperCase(char *cp);
void AddYPEntries(void);

int Verbose = 0;	/* to get the gory details */
int UucpOK = 0;		/* pass all UUCP names right through */
int DomainOK = 0;	/* pass all Domain names (with dots) */
int ErrorCheck = 0;	/* check carefully for errors */
int NoOutput = 0;	/* no output, just do the check */
int Simple = 0;		/* Do not do the user name preference step */
int NameMode = 0;	/* Try to capitalize as names */

DBM *Indbm = NULL, *Scandbm = NULL, *Outdbm = NULL;

int
IsMailingList(char *s)
{
	/*
	 * returns true if the given string is a mailing list
	 */
	char *p;

	if (strchr(s, ','))
		return (1);
	if (strchr(s, '|'))
		return (1);
	p = strchr(s, ':');
	if (p && strncmp(p, MKAL_INCLUDE, sizeof (MKAL_INCLUDE)))
		return (1);
	return (0);
}

int
IsQualified(char *s, char *p, char *h)
{
	/*
	 * returns true if the given string is qualified with a host name
	 */
	register char *middle;

	middle = strchr(s, '@');
	if (middle) {
		for (middle = s; *middle != '@'; *p++ = *middle++)
			continue;
		*p = '\0';
		CopyName(h, middle+1, strlen(middle + 1));
		return (1);
	}
	middle = strrchr(s, '!');
	if (middle) {
		strcpy(p, middle+1);
		*middle = '\0';
		CopyName(h, s, strlen(s));
		*middle = '!';
		return (1);
	}
	return (0);
}

int
IsMaint(char *s)
{
	/*
	 * returns true if the given string is one of the maintenence
	 * strings used in sendmail or NIS.
	 */
	if (*s == '@')
		return (1);
	if (strncmp(s, yp_prefix, yp_prefix_sz) == 0)
		return (1);
	return (0);
}

void
CopyName(char *dst, char *src, int len)
{
	/*
	 * copy a string, but ignore white space
	 */
	while (*src && len--) {
		if (isspace(*src))
			src++;
		else
			*dst++ = *src++;
	}
	*dst = '\0';
}

int
Compare(char *s1, char *s2)
{
	/*
	 * compare strings, but ignore white space
	 */
	while (*s1 != '\0' && isspace(*s1))
		s1++;
	while (*s2 != '\0' && isspace(*s2))
		s2++;
	return (strcmp(s1, s2));
}

void
ProcessMap(void)
{
	datum key, value, part, partvalue;
	char address[PBLKSIZ];	/* qualified version */
	char user[PBLKSIZ];		/* unqualified version */
	char userpart[PBLKSIZ];	/* unqualified part of qualified addr. */
	char hostpart[PBLKSIZ];	/* rest of qualified addr. */

	for (key = dbm_firstkey(Scandbm); key.dptr != NULL;
						key = dbm_nextkey(Scandbm)) {
		value = dbm_fetch(Indbm, key);
		CopyName(address, value.dptr, value.dsize);
		CopyName(user, key.dptr, key.dsize);
		if (address == NULL) continue;
		if (IsMailingList(address)) continue;
		if (!IsQualified(address, userpart, hostpart)) continue;
		if (IsMaint(user)) continue;
		if (ErrorCheck && HostCheck(hostpart, address)) {
			printf("Invalid host %s in %s:%s\n",
				hostpart, user, address);
			continue;
		}
		part.dptr = userpart;
		part.dsize = strlen(userpart) + 1;
		if (Simple)
			partvalue.dptr = NULL;
		else
			partvalue = dbm_fetch(Indbm, part);
		value.dptr = address;
		value.dsize = strlen(address) + 1;
		if (partvalue.dptr != NULL &&
			Compare(partvalue.dptr, user) == 0) {

			if (NameMode)
				DoName(userpart);
			if (!NoOutput)
				dbm_store(Outdbm, value, part, DBM_REPLACE);
			if (Verbose) printf("%s --> %s --> %s\n",
						userpart, user, address);
		} else {
			if (NameMode)
				DoName(user);
			key.dptr = user;
			key.dsize = strlen(user) + 1;
			if (!NoOutput)
				dbm_store(Outdbm, value, key, DBM_REPLACE);
			if (Verbose)
				printf("%s --> %s\n", user, address);
		}
	}
}


/*
 * Returns true if this is an invalid host
 */
int
HostCheck(char *h, char *a)
{
	struct hostent *hp;

	if (DomainOK && strchr(a, '.'))
		return (0);

	if (UucpOK && strchr(a, '!'))
		return (0);

	hp = gethostbyname(h);
	return (hp == NULL);
}

/*
 * Apply some Heurisitcs to upper case-ify the name
 * If it has a dot in it.
 */
void
DoName(char *cp)
{
	if (strchr(cp, '.') == NULL)
		return;

	while (*cp) {
		UpperCase(cp);
		while (*cp && *cp != '-' && *cp != '.')
			cp++;
		if (*cp)
			cp++;	/* skip past punctuation */
	}
}

/*
 * upper cases one name - stops at a .
 */
void
UpperCase(char *cp)
{
	int ch = cp[0];

	if (isupper(ch))
		ch = tolower(ch);

	if (ch == 'f' && cp[1] == 'f')
		return; /* handle ff */

	if (ch == 'm' && cp[1] == 'c' && islower(cp[2]))
		cp[2] = toupper(cp[2]);
	if (islower(ch))
		cp[0] = toupper(ch);
}

void
AddYPEntries(void)
{
	datum key, value;
	char last_modified[PBLKSIZ];
	char host_name[PBLKSIZ];
	time_t now;

	/*
	 * Add the special NIS entries.
	 */
	key.dptr = yp_last_modified;
	key.dsize = yp_last_modified_sz;
	time(&now);
	sprintf(last_modified, "%10.10d", now);
	value.dptr = last_modified;
	value.dsize = strlen(value.dptr);
	dbm_store(Outdbm, key, value, DBM_REPLACE);

	key.dptr = yp_master_name;
	key.dsize = yp_master_name_sz;
	sysinfo(SI_HOSTNAME, host_name, sizeof (host_name));
	value.dptr = host_name;
	value.dsize = strlen(value.dptr);
	dbm_store(Outdbm, key, value, DBM_REPLACE);
}

int
main(int argc, char *argv[])
{
	while (argc > 1 && argv[1][0] == '-') {
	switch (argv[1][1]) {
		case 'v':
			Verbose = 1;
			break;

		case 'u':
			UucpOK = 1;
			break;

		case 'd':
			DomainOK = 1;
			break;

		case 'e':
			ErrorCheck = 1;
			break;

		case 's':
			Simple = 1;
			break;

		case 'n':
			NameMode = 1;
			break;

		default:
			printf("Unknown option %c\n", argv[1][1]);
			break;
		}
		argc--; argv++;
	}
	if (argc < 2) {
printf("Usage: mkalias [-e] [-v] [-u] [-d] [-s] [-n] <input> <output>\n");
		exit(1);
	}
	Indbm = dbm_open(argv[1], O_RDONLY, 0);
	if (Indbm == NULL) {
		printf("Unable to open input database %s\n", argv[1]);
		exit(1);
	}
	Scandbm = dbm_open(argv[1], O_RDONLY, 0);
	if (Scandbm == NULL) {
		printf("Unable to open input database %s\n", argv[1]);
		exit(1);
	}
	if (argv[2] == NULL)
		NoOutput = 1;
	else {
		Outdbm = dbm_open(argv[2], O_RDWR|O_CREAT|O_TRUNC, 0644);
		if (Outdbm == NULL) {
			printf("Unable to open output database %s\n", argv[2]);
			exit(1);
		}
	}
	ProcessMap();
	dbm_close(Indbm);
	dbm_close(Scandbm);
	if (!NoOutput) {
		AddYPEntries();
		dbm_close(Outdbm);
	}
	return (0);
}