OpenBSD-4.6/usr.bin/vacation/vacation.c
/* $OpenBSD: vacation.c,v 1.30 2007/09/11 15:47:17 gilles Exp $ */
/* $NetBSD: vacation.c,v 1.7 1995/04/29 05:58:27 cgd Exp $ */
/*
* Copyright (c) 1983, 1987, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1983, 1987, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)vacation.c 8.2 (Berkeley) 1/26/94";
#endif
static char rcsid[] = "$OpenBSD: vacation.c,v 1.30 2007/09/11 15:47:17 gilles Exp $";
#endif /* not lint */
/*
** Vacation
** Copyright (c) 1983 Eric P. Allman
** Berkeley, California
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pwd.h>
#include <db.h>
#include <time.h>
#include <syslog.h>
#include <tzfile.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <paths.h>
/*
* VACATION -- return a message to the sender when on vacation.
*
* This program is invoked as a message receiver. It returns a
* message specified by the user to whomever sent the mail, taking
* care not to return a message too often to prevent "I am on
* vacation" loops.
*/
#define MAXLINE 1024 /* max line from mail header */
#define VDB ".vacation.db" /* dbm's database */
#define VMSG ".vacation.msg" /* vacation message */
typedef struct alias {
struct alias *next;
char *name;
} ALIAS;
ALIAS *names;
DB *db;
char from[MAXLINE];
char subj[MAXLINE];
int junkmail(void);
int nsearch(char *, char *);
void readheaders(void);
int recent(void);
void sendmessage(char *);
void setinterval(time_t);
void setreply(void);
void usage(void);
int
main(int argc, char *argv[])
{
int ch, iflag, flags;
struct passwd *pw;
time_t interval;
struct stat sb;
ALIAS *cur;
opterr = iflag = 0;
interval = -1;
while ((ch = getopt(argc, argv, "a:Iir:")) != -1)
switch ((char)ch) {
case 'a': /* alias */
if (!(cur = (ALIAS *)malloc((u_int)sizeof(ALIAS))))
break;
cur->name = optarg;
cur->next = names;
names = cur;
break;
case 'I': /* backward compatible */
case 'i': /* init the database */
iflag = 1;
break;
case 'r':
if (isdigit(*optarg)) {
interval = atol(optarg) * SECSPERDAY;
if (interval < 0)
usage();
} else
interval = (time_t)LONG_MAX; /* XXX */
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc != 1) {
if (!iflag)
usage();
if (!(pw = getpwuid(getuid()))) {
syslog(LOG_ERR,
"no such user uid %u.", getuid());
exit(1);
}
} else if (!(pw = getpwnam(*argv))) {
syslog(LOG_ERR, "no such user %s.", *argv);
exit(1);
}
if (chdir(pw->pw_dir)) {
syslog(LOG_NOTICE,
"no such directory %s.", pw->pw_dir);
exit(1);
}
/*
* dbopen(3) can not deal with a zero-length file w/o O_TRUNC.
*/
if (iflag == 1 || (stat(VDB, &sb) == 0 && sb.st_size == (off_t)0))
flags = O_CREAT|O_RDWR|O_TRUNC;
else
flags = O_CREAT|O_RDWR;
db = dbopen(VDB, flags, S_IRUSR|S_IWUSR, DB_HASH, NULL);
if (!db) {
syslog(LOG_NOTICE, "%s: %m", VDB);
exit(1);
}
if (interval != -1)
setinterval(interval);
if (iflag) {
(void)(db->close)(db);
exit(0);
}
if (!(cur = malloc((u_int)sizeof(ALIAS))))
exit(1);
cur->name = pw->pw_name;
cur->next = names;
names = cur;
readheaders();
if (!recent()) {
setreply();
(void)(db->close)(db);
sendmessage(pw->pw_name);
} else
(void)(db->close)(db);
exit(0);
/* NOTREACHED */
}
/*
* readheaders --
* read mail headers
*/
void
readheaders(void)
{
char buf[MAXLINE], *p;
int tome, cont;
ALIAS *cur;
cont = tome = 0;
while (fgets(buf, sizeof(buf), stdin) && *buf != '\n')
switch (*buf) {
case 'A': /* "Auto-Submitted:" */
case 'a':
cont = 0;
if (strncasecmp(buf, "Auto-Submitted:", 15))
break;
for (p = buf + 15; isspace(*p); ++p)
;
/*
* RFC 3834 section 2:
* Automatic responses SHOULD NOT be issued in response
* to any message which contains an Auto-Submitted
* header where the field has any value other than "no".
*/
if ((p[0] == 'n' || p[0] == 'N') &&
(p[1] == 'o' || p[1] == 'O')) {
for (p += 2; isspace(*p); ++p)
;
if (*p == '\0')
break; /* Auto-Submitted: no */
}
exit(0);
case 'F': /* "From " */
case 'f':
cont = 0;
if (!strncasecmp(buf, "From ", 5)) {
for (p = buf + 5; *p && *p != ' '; ++p)
;
*p = '\0';
(void)strlcpy(from, buf + 5, sizeof(from));
from[strcspn(from, "\n")] = '\0';
if (junkmail())
exit(0);
}
break;
case 'L': /* "List-Id:" */
case 'l':
cont = 0;
/*
* If present (with any value), message is coming from a
* mailing list, cf. RFC2919.
*/
if (strncasecmp(buf, "List-Id:", 8) == 0)
exit(0);
break;
case 'R': /* "Return-Path:" */
case 'r':
cont = 0;
if (strncasecmp(buf, "Return-Path:",
sizeof("Return-Path:")-1) ||
(buf[12] != ' ' && buf[12] != '\t'))
break;
for (p = buf + 12; isspace(*p); ++p)
;
if (strlcpy(from, p, sizeof(from)) >= sizeof(from)) {
syslog(LOG_NOTICE,
"Return-Path %s exceeds limits", p);
exit(1);
}
from[strcspn(from, "\n")] = '\0';
if (junkmail())
exit(0);
break;
case 'P': /* "Precedence:" */
case 'p':
cont = 0;
if (strncasecmp(buf, "Precedence:", 11))
break;
for (p = buf + 11; isspace(*p); ++p)
;
if (!strncasecmp(p, "junk", 4) ||
!strncasecmp(p, "bulk", 4) ||
!strncasecmp(p, "list", 4))
exit(0);
break;
case 'S': /* Subject: */
case 's':
cont = 0;
if (strncasecmp(buf, "Subject:",
sizeof("Subject:")-1) ||
(buf[8] != ' ' && buf[8] != '\t'))
break;
for (p = buf + 8; isspace(*p); ++p)
;
if (strlcpy(subj, p, sizeof(subj)) >= sizeof(subj)) {
syslog(LOG_NOTICE,
"Subject %s exceeds limits", p);
exit(1);
}
subj[strcspn(subj, "\n")] = '\0';
break;
case 'C': /* "Cc:" */
case 'c':
if (strncasecmp(buf, "Cc:", 3))
break;
cont = 1;
goto findme;
case 'T': /* "To:" */
case 't':
if (strncasecmp(buf, "To:", 3))
break;
cont = 1;
goto findme;
default:
if (!isspace(*buf) || !cont || tome) {
cont = 0;
break;
}
findme: for (cur = names; !tome && cur; cur = cur->next)
tome += nsearch(cur->name, buf);
}
if (!tome)
exit(0);
if (!*from) {
syslog(LOG_NOTICE, "no initial \"From\" or \"Return-Path\"line.");
exit(1);
}
}
/*
* nsearch --
* do a nice, slow, search of a string for a substring.
*/
int
nsearch(char *name, char *str)
{
int len;
for (len = strlen(name); *str; ++str)
if (!strncasecmp(name, str, len))
return(1);
return(0);
}
/*
* junkmail --
* read the header and return if automagic/junk/bulk/list mail
*/
int
junkmail(void)
{
static struct ignore {
char *name;
int len;
} ignore[] = {
{ "-request", 8 },
{ "postmaster", 10 },
{ "uucp", 4 },
{ "mailer-daemon", 13 },
{ "mailer", 6 },
{ "-relay", 6 },
{ NULL, 0 }
};
struct ignore *cur;
int len;
char *p;
/*
* This is mildly amusing, and I'm not positive it's right; trying
* to find the "real" name of the sender, assuming that addresses
* will be some variant of:
*
* From site!site!SENDER%site.domain%site.domain@site.domain
*/
if (!(p = strchr(from, '%'))) {
if (!(p = strchr(from, '@'))) {
if ((p = strrchr(from, '!')))
++p;
else
p = from;
for (; *p; ++p)
;
}
}
len = p - from;
for (cur = ignore; cur->name; ++cur)
if (len >= cur->len &&
!strncasecmp(cur->name, p - cur->len, cur->len))
return(1);
return(0);
}
#define VIT "__VACATION__INTERVAL__TIMER__"
/*
* recent --
* find out if user has gotten a vacation message recently.
* use bcopy for machines with alignment restrictions
*/
int
recent(void)
{
time_t then, next;
DBT key, data;
/* get interval time */
key.data = VIT;
key.size = sizeof(VIT);
if ((db->get)(db, &key, &data, 0))
next = SECSPERDAY * DAYSPERWEEK;
else
bcopy(data.data, &next, sizeof(next));
/* get record for this address */
key.data = from;
key.size = strlen(from);
if (!(db->get)(db, &key, &data, 0)) {
bcopy(data.data, &then, sizeof(then));
if (next == (time_t)LONG_MAX || /* XXX */
then + next > time(NULL))
return(1);
}
return(0);
}
/*
* setinterval --
* store the reply interval
*/
void
setinterval(time_t interval)
{
DBT key, data;
key.data = VIT;
key.size = sizeof(VIT);
data.data = &interval;
data.size = sizeof(interval);
(void)(db->put)(db, &key, &data, 0);
}
/*
* setreply --
* store that this user knows about the vacation.
*/
void
setreply(void)
{
DBT key, data;
time_t now;
key.data = from;
key.size = strlen(from);
(void)time(&now);
data.data = &now;
data.size = sizeof(now);
(void)(db->put)(db, &key, &data, 0);
}
/*
* sendmessage --
* exec sendmail to send the vacation file to sender
*/
void
sendmessage(char *myname)
{
char buf[MAXLINE];
FILE *mfp, *sfp;
int pvect[2], i;
mfp = fopen(VMSG, "r");
if (mfp == NULL) {
syslog(LOG_NOTICE, "no ~%s/%s file.", myname, VMSG);
exit(1);
}
if (pipe(pvect) < 0) {
syslog(LOG_ERR, "pipe: %m");
exit(1);
}
i = vfork();
if (i < 0) {
syslog(LOG_ERR, "fork: %m");
exit(1);
}
if (i == 0) {
dup2(pvect[0], 0);
close(pvect[0]);
close(pvect[1]);
close(fileno(mfp));
execl(_PATH_SENDMAIL, "sendmail", "-f", myname, "--",
from, (char *)NULL);
syslog(LOG_ERR, "can't exec %s: %m", _PATH_SENDMAIL);
_exit(1);
}
close(pvect[0]);
sfp = fdopen(pvect[1], "w");
if (sfp == NULL) {
/* XXX could not fdopen; likely out of memory */
fclose(mfp);
close(pvect[1]);
return;
}
fprintf(sfp, "To: %s\n", from);
fputs("Auto-Submitted: auto-replied\n", sfp);
while (fgets(buf, sizeof buf, mfp)) {
char *s = strstr(buf, "$SUBJECT");
if (s) {
*s = 0;
fputs(buf, sfp);
fputs(subj, sfp);
fputs(s+8, sfp);
} else {
fputs(buf, sfp);
}
}
fclose(mfp);
fclose(sfp);
}
void
usage(void)
{
syslog(LOG_NOTICE, "uid %u: usage: vacation [-i] [-a alias] login",
getuid());
exit(1);
}