OpenBSD-4.6/libexec/mail.local/mail.local.c
/* $OpenBSD: mail.local.c,v 1.31 2008/05/26 09:22:03 sobrado Exp $ */
/*-
* Copyright (c) 1996-1998 Theo de Raadt <deraadt@theos.com>
* Copyright (c) 1996-1998 David Mazieres <dm@lcs.mit.edu>
* Copyright (c) 1990 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
char copyright[] =
"@(#) Copyright (c) 1990 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)mail.local.c 5.6 (Berkeley) 6/19/91";
#else
static char rcsid[] = "$OpenBSD: mail.local.c,v 1.31 2008/05/26 09:22:03 sobrado Exp $";
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <syslog.h>
#include <fcntl.h>
#include <netdb.h>
#include <pwd.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pathnames.h"
#include "mail.local.h"
int
main(int argc, char *argv[])
{
struct passwd *pw;
int ch, fd, eval, lockfile=1, holdme=0;
uid_t uid;
char *from;
openlog("mail.local", LOG_PERROR, LOG_MAIL);
from = NULL;
while ((ch = getopt(argc, argv, "lLdf:r:H")) != -1)
switch (ch) {
case 'd': /* backward compatible */
break;
case 'f':
case 'r': /* backward compatible */
if (from)
merr(FATAL, "multiple -f options");
from = optarg;
break;
case 'l':
lockfile=1;
break;
case 'L':
lockfile=0;
break;
case 'H':
holdme=1;
break;
default:
usage();
}
argc -= optind;
argv += optind;
/* Support -H flag for backwards compat */
if (holdme) {
execl(_PATH_LOCKSPOOL, "lockspool", (char *)NULL);
merr(FATAL, "execl: lockspool: %s", strerror(errno));
} else {
if (!*argv)
usage();
if (geteuid() != 0)
merr(FATAL, "may only be run by the superuser");
}
/*
* If from not specified, use the name from getlogin() if the
* uid matches, otherwise, use the name from the password file
* corresponding to the uid.
*/
uid = getuid();
if (!from && (!(from = getlogin()) ||
!(pw = getpwnam(from)) || pw->pw_uid != uid))
from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
fd = storemail(from);
for (eval = 0; *argv; ++argv)
eval |= deliver(fd, *argv, lockfile);
exit(eval);
}
int
storemail(char *from)
{
FILE *fp = NULL;
time_t tval;
int fd, eline;
size_t len;
char *line, *tbuf;
if ((tbuf = strdup(_PATH_LOCTMP)) == NULL)
merr(FATAL, "unable to allocate memory");
if ((fd = mkstemp(tbuf)) == -1 || !(fp = fdopen(fd, "w+")))
merr(FATAL, "unable to open temporary file");
(void)unlink(tbuf);
free(tbuf);
(void)time(&tval);
(void)fprintf(fp, "From %s %s", from, ctime(&tval));
for (eline = 1, tbuf = NULL; (line = fgetln(stdin, &len));) {
/* We have to NUL-terminate the line since fgetln does not */
if (line[len - 1] == '\n')
line[len - 1] = '\0';
else {
/* No trailing newline, so alloc space and copy */
if ((tbuf = malloc(len + 1)) == NULL)
merr(FATAL, "unable to allocate memory");
memcpy(tbuf, line, len);
tbuf[len] = '\0';
line = tbuf;
}
if (line[0] == '\0')
eline = 1;
else {
if (eline && line[0] == 'F' && len > 5 &&
!memcmp(line, "From ", 5))
(void)putc('>', fp);
eline = 0;
}
(void)fprintf(fp, "%s\n", line);
if (ferror(fp))
break;
}
if (tbuf)
free(tbuf);
/* Output a newline; note, empty messages are allowed. */
(void)putc('\n', fp);
(void)fflush(fp);
if (ferror(fp))
merr(FATAL, "temporary file write error");
return(fd);
}
int
deliver(int fd, char *name, int lockfile)
{
struct stat sb, fsb;
struct passwd *pw;
int mbfd=-1, rval=1, lfd=-1;
char biffmsg[100], buf[8*1024], path[MAXPATHLEN];
off_t curoff;
size_t off;
ssize_t nr, nw;
/*
* Disallow delivery to unknown names -- special mailboxes can be
* handled in the sendmail aliases file.
*/
if (!(pw = getpwnam(name))) {
merr(NOTFATAL, "unknown name: %s", name);
return(1);
}
(void)snprintf(path, sizeof path, "%s/%s", _PATH_MAILDIR, name);
if (lockfile) {
lfd = getlock(name, pw);
if (lfd == -1)
return (1);
}
/* after this point, always exit via bad to remove lockfile */
retry:
if (lstat(path, &sb)) {
if (errno != ENOENT) {
merr(NOTFATAL, "%s: %s", path, strerror(errno));
goto bad;
}
if ((mbfd = open(path, O_APPEND|O_CREAT|O_EXCL|O_WRONLY|O_EXLOCK,
S_IRUSR|S_IWUSR)) < 0) {
if (errno == EEXIST) {
/* file appeared since lstat */
goto retry;
} else {
merr(NOTFATAL, "%s: %s", path, strerror(errno));
goto bad;
}
}
/*
* Set the owner and group. Historically, binmail repeated
* this at each mail delivery. We no longer do this, assuming
* that if the ownership or permissions were changed there
* was a reason for doing so.
*/
if (fchown(mbfd, pw->pw_uid, pw->pw_gid) < 0) {
merr(NOTFATAL, "chown %u:%u: %s",
pw->pw_uid, pw->pw_gid, name);
goto bad;
}
} else {
if (sb.st_nlink != 1 || !S_ISREG(sb.st_mode)) {
merr(NOTFATAL, "%s: linked or special file", path);
goto bad;
}
if ((mbfd = open(path, O_APPEND|O_WRONLY|O_EXLOCK,
S_IRUSR|S_IWUSR)) < 0) {
merr(NOTFATAL, "%s: %s", path, strerror(errno));
goto bad;
}
if (fstat(mbfd, &fsb)) {
/* relating error to path may be bad style */
merr(NOTFATAL, "%s: %s", path, strerror(errno));
goto bad;
}
if (sb.st_dev != fsb.st_dev || sb.st_ino != fsb.st_ino) {
merr(NOTFATAL, "%s: changed after open", path);
goto bad;
}
/* paranoia? */
if (fsb.st_nlink != 1 || !S_ISREG(fsb.st_mode)) {
merr(NOTFATAL, "%s: linked or special file", path);
goto bad;
}
}
curoff = lseek(mbfd, 0, SEEK_END);
(void)snprintf(biffmsg, sizeof biffmsg, "%s@%qd\n", name, curoff);
if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
merr(NOTFATAL, "temporary file: %s", strerror(errno));
goto bad;
}
while ((nr = read(fd, buf, sizeof(buf))) > 0)
for (off = 0; off < nr; off += nw)
if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
merr(NOTFATAL, "%s: %s", path, strerror(errno));
(void)ftruncate(mbfd, curoff);
goto bad;
}
if (nr == 0) {
rval = 0;
} else {
(void)ftruncate(mbfd, curoff);
merr(FATAL, "temporary file: %s", strerror(errno));
}
bad:
if (lfd != -1) {
rellock();
close(lfd);
}
if (mbfd != -1) {
(void)fsync(mbfd); /* Don't wait for update. */
(void)close(mbfd); /* Implicit unlock. */
}
if (!rval)
notifybiff(biffmsg);
return(rval);
}
void
notifybiff(char *msg)
{
static struct sockaddr_in addr;
static int f = -1;
struct hostent *hp;
struct servent *sp;
size_t len;
if (!addr.sin_family) {
/* Be silent if biff service not available. */
if (!(sp = getservbyname("biff", "udp")))
return;
if (!(hp = gethostbyname("localhost"))) {
merr(NOTFATAL, "localhost: %s", strerror(errno));
return;
}
addr.sin_len = sizeof(struct sockaddr_in);
addr.sin_family = hp->h_addrtype;
addr.sin_port = sp->s_port;
bcopy(hp->h_addr, &addr.sin_addr, (size_t)hp->h_length);
}
if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
merr(NOTFATAL, "socket: %s", strerror(errno));
return;
}
len = strlen(msg) + 1;
if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
!= len)
merr(NOTFATAL, "sendto biff: %s", strerror(errno));
}
void
usage(void)
{
merr(FATAL, "usage: mail.local [-Ll] [-f from] user ...");
}