FreeBSD-5.3/usr.sbin/lpr/lpr/lpr.c
/*
* Copyright (c) 1983, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 const char copyright[] =
"@(#) Copyright (c) 1983, 1989, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#if 0
#ifndef lint
static char sccsid[] = "@(#)lpr.c 8.4 (Berkeley) 4/28/95";
#endif /* not lint */
#endif
#include "lp.cdefs.h" /* A cross-platform version of <sys/cdefs.h> */
__FBSDID("$FreeBSD: src/usr.sbin/lpr/lpr/lpr.c,v 1.44 2003/07/15 08:40:31 gad Exp $");
/*
* lpr -- off line print
*
* Allows multiple printers and printers on remote machines by
* using information from a printer data base.
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <netinet/in.h> /* N_BADMAG uses ntohl() */
#include <dirent.h>
#include <fcntl.h>
#include <a.out.h>
#include <err.h>
#include <locale.h>
#include <signal.h>
#include <syslog.h>
#include <pwd.h>
#include <grp.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include "lp.h"
#include "lp.local.h"
#include "pathnames.h"
static char *cfname; /* daemon control files, linked from tf's */
static char *class = local_host; /* class title on header page */
static char *dfname; /* data files */
static char *fonts[4]; /* troff font names */
static char format = 'f'; /* format char for printing files */
static int hdr = 1; /* print header or not (default is yes) */
static int iflag; /* indentation wanted */
static int inchar; /* location to increment char in file names */
static int indent; /* amount to indent */
static const char *jobname; /* job name on header page */
static int mailflg; /* send mail */
static int nact; /* number of jobs to act on */
static int ncopies = 1; /* # of copies to make */
static char *lpr_username; /* person sending the print job(s) */
static int qflag; /* q job, but don't exec daemon */
static int rflag; /* remove files upon completion */
static int sflag; /* symbolic link flag */
static int tfd; /* control file descriptor */
static char *tfname; /* tmp copy of cf before linking */
static char *title; /* pr'ing title */
static char *locale; /* pr'ing locale */
static int userid; /* user id */
static char *Uflag; /* user name specified with -U flag */
static char *width; /* width for versatec printing */
static char *Zflag; /* extra filter options for LPRng servers */
static struct stat statb;
static void card(int _c, const char *_p2);
static int checkwriteperm(const char *_file, const char *_directory);
static void chkprinter(const char *_ptrname, struct printer *_pp);
static void cleanup(int _signo);
static void copy(const struct printer *_pp, int _f, const char _n[]);
static char *itoa(int _i);
static const char *linked(const char *_file);
int main(int _argc, char *_argv[]);
static char *lmktemp(const struct printer *_pp, const char *_id,
int _num, int len);
static void mktemps(const struct printer *_pp);
static int nfile(char *_n);
static int test(const char *_file);
static void usage(void);
uid_t uid, euid;
int
main(int argc, char *argv[])
{
struct passwd *pw;
struct group *gptr;
const char *arg, *cp, *printer;
char *p;
char buf[BUFSIZ];
int c, i, f, errs;
int ret, didlink;
struct stat stb;
struct stat statb1, statb2;
struct printer myprinter, *pp = &myprinter;
printer = NULL;
euid = geteuid();
uid = getuid();
seteuid(uid);
if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
signal(SIGHUP, cleanup);
if (signal(SIGINT, SIG_IGN) != SIG_IGN)
signal(SIGINT, cleanup);
if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
signal(SIGQUIT, cleanup);
if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
signal(SIGTERM, cleanup);
progname = argv[0];
gethostname(local_host, sizeof(local_host));
openlog("lpd", 0, LOG_LPR);
errs = 0;
while ((c = getopt(argc, argv,
":#:1:2:3:4:C:J:L:P:T:U:Z:cdfghi:lnmprstvw:"))
!= -1)
switch (c) {
case '#': /* n copies */
i = strtol(optarg, &p, 10);
if (*p)
errx(1, "Bad argument to -#, number expected");
if (i > 0)
ncopies = i;
break;
case '1': /* troff fonts */
case '2':
case '3':
case '4':
fonts[optopt - '1'] = optarg;
break;
case 'C': /* classification spec */
hdr++;
class = optarg;
break;
case 'J': /* job name */
hdr++;
jobname = optarg;
break;
case 'P': /* specifiy printer name */
printer = optarg;
break;
case 'L': /* pr's locale */
locale = optarg;
break;
case 'T': /* pr's title line */
title = optarg;
break;
case 'U': /* user name */
hdr++;
Uflag = optarg;
break;
case 'Z':
Zflag = optarg;
break;
case 'c': /* print cifplot output */
case 'd': /* print tex output (dvi files) */
case 'g': /* print graph(1G) output */
case 'l': /* literal output */
case 'n': /* print ditroff output */
case 't': /* print troff output (cat files) */
case 'p': /* print using ``pr'' */
case 'v': /* print vplot output */
format = optopt;
break;
case 'f': /* print fortran output */
format = 'r';
break;
case 'h': /* nulifiy header page */
hdr = 0;
break;
case 'i': /* indent output */
iflag++;
indent = strtol(optarg, &p, 10);
if (*p)
errx(1, "Bad argument to -i, number expected");
break;
case 'm': /* send mail when done */
mailflg++;
break;
case 'q': /* just queue job */
qflag++;
break;
case 'r': /* remove file when done */
rflag++;
break;
case 's': /* try to link files */
sflag++;
break;
case 'w': /* versatec page width */
width = optarg;
break;
case ':': /* catch "missing argument" error */
if (optopt == 'i') {
iflag++; /* -i without args is valid */
indent = 8;
} else
errs++;
break;
default:
errs++;
}
argc -= optind;
argv += optind;
if (errs)
usage();
if (printer == NULL && (printer = getenv("PRINTER")) == NULL)
printer = DEFLP;
chkprinter(printer, pp);
if (pp->no_copies && ncopies > 1)
errx(1, "multiple copies are not allowed");
if (pp->max_copies > 0 && ncopies > pp->max_copies)
errx(1, "only %ld copies are allowed", pp->max_copies);
/*
* Get the identity of the person doing the lpr using the same
* algorithm as lprm. Actually, not quite -- lprm will override
* the login name with "root" if the user is running as root;
* the daemon actually checks for the string "root" in its
* permission checking. Sigh.
*/
userid = getuid();
if (Uflag) {
if (userid != 0 && userid != pp->daemon_user)
errx(1, "only privileged users may use the `-U' flag");
lpr_username = Uflag; /* -U person doing 'lpr' */
} else {
lpr_username = getlogin(); /* person doing 'lpr' */
if (userid != pp->daemon_user || lpr_username == 0) {
if ((pw = getpwuid(userid)) == NULL)
errx(1, "Who are you?");
lpr_username = pw->pw_name;
}
}
/*
* Check for restricted group access.
*/
if (pp->restrict_grp != NULL && userid != pp->daemon_user) {
if ((gptr = getgrnam(pp->restrict_grp)) == NULL)
errx(1, "Restricted group specified incorrectly");
if (gptr->gr_gid != getgid()) {
while (*gptr->gr_mem != NULL) {
if ((strcmp(lpr_username, *gptr->gr_mem)) == 0)
break;
gptr->gr_mem++;
}
if (*gptr->gr_mem == NULL)
errx(1, "Not a member of the restricted group");
}
}
/*
* Check to make sure queuing is enabled if userid is not root.
*/
lock_file_name(pp, buf, sizeof buf);
if (userid && stat(buf, &stb) == 0 && (stb.st_mode & LFM_QUEUE_DIS))
errx(1, "Printer queue is disabled");
/*
* Initialize the control file.
*/
mktemps(pp);
tfd = nfile(tfname);
seteuid(euid);
(void) fchown(tfd, pp->daemon_user, -1);
/* owned by daemon for protection */
seteuid(uid);
card('H', local_host);
card('P', lpr_username);
card('C', class);
if (hdr && !pp->no_header) {
if (jobname == NULL) {
if (argc == 0)
jobname = "stdin";
else
jobname = ((arg = strrchr(argv[0], '/'))
? arg + 1 : argv[0]);
}
card('J', jobname);
card('L', lpr_username);
}
if (format != 'p' && Zflag != 0)
card('Z', Zflag);
if (iflag)
card('I', itoa(indent));
if (mailflg)
card('M', lpr_username);
if (format == 't' || format == 'n' || format == 'd')
for (i = 0; i < 4; i++)
if (fonts[i] != NULL)
card('1'+i, fonts[i]);
if (width != NULL)
card('W', width);
/*
* XXX
* Our use of `Z' here is incompatible with LPRng's
* use. We assume that the only use of our existing
* `Z' card is as shown for `p' format (pr) files.
*/
if (format == 'p') {
char *s;
if (locale)
card('Z', locale);
else if ((s = setlocale(LC_TIME, "")) != NULL)
card('Z', s);
}
/*
* Read the files and spool them.
*/
if (argc == 0)
copy(pp, 0, " ");
else while (argc--) {
if (argv[0][0] == '-' && argv[0][1] == '\0') {
/* use stdin */
copy(pp, 0, " ");
argv++;
continue;
}
if ((f = test(arg = *argv++)) < 0)
continue; /* file unreasonable */
if (sflag && (cp = linked(arg)) != NULL) {
(void) snprintf(buf, sizeof(buf), "%d %d", statb.st_dev,
statb.st_ino);
card('S', buf);
if (format == 'p')
card('T', title ? title : arg);
for (i = 0; i < ncopies; i++)
card(format, &dfname[inchar-2]);
card('U', &dfname[inchar-2]);
if (f)
card('U', cp);
card('N', arg);
dfname[inchar]++;
nact++;
continue;
}
if (sflag)
printf("%s: %s: not linked, copying instead\n",
progname, arg);
if (f) {
/*
* The user wants the file removed after it is copied
* to the spool area, so see if the file can be moved
* instead of copy/unlink'ed. This is much faster and
* uses less spool space than copying the file. This
* can be very significant when running services like
* samba, pcnfs, CAP, et al.
*/
seteuid(euid);
didlink = 0;
/*
* There are several things to check to avoid any
* security issues. Some of these are redundant
* under BSD's, but are necessary when lpr is built
* under some other OS's (which I do do...)
*/
if (lstat(arg, &statb1) < 0)
goto nohardlink;
if (S_ISLNK(statb1.st_mode))
goto nohardlink;
if (link(arg, dfname) != 0)
goto nohardlink;
didlink = 1;
/*
* Make sure the user hasn't tried to trick us via
* any race conditions
*/
if (lstat(dfname, &statb2) < 0)
goto nohardlink;
if (statb1.st_dev != statb2.st_dev)
goto nohardlink;
if (statb1.st_ino != statb2.st_ino)
goto nohardlink;
/*
* Skip if the file already had multiple hard links,
* because changing the owner and access-bits would
* change ALL versions of the file
*/
if (statb2.st_nlink > 2)
goto nohardlink;
/*
* If we can access and remove the original file
* without special setuid-ness then this method is
* safe. Otherwise, abandon the move and fall back
* to the (usual) copy method.
*/
seteuid(uid);
ret = access(dfname, R_OK);
if (ret == 0)
ret = unlink(arg);
seteuid(euid);
if (ret != 0)
goto nohardlink;
/*
* Unlink of user file was successful. Change the
* owner and permissions, add entries to the control
* file, and skip the file copying step.
*/
chown(dfname, pp->daemon_user, getegid());
chmod(dfname, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
seteuid(uid);
if (format == 'p')
card('T', title ? title : arg);
for (i = 0; i < ncopies; i++)
card(format, &dfname[inchar-2]);
card('U', &dfname[inchar-2]);
card('N', arg);
nact++;
continue;
nohardlink:
if (didlink)
unlink(dfname);
seteuid(uid); /* restore old uid */
} /* end: if (f) */
if ((i = open(arg, O_RDONLY)) < 0) {
printf("%s: cannot open %s\n", progname, arg);
} else {
copy(pp, i, arg);
(void) close(i);
if (f && unlink(arg) < 0)
printf("%s: %s: not removed\n", progname, arg);
}
}
if (nact) {
(void) close(tfd);
tfname[inchar]--;
/*
* Touch the control file to fix position in the queue.
*/
seteuid(euid);
if ((tfd = open(tfname, O_RDWR)) >= 0) {
char touch_c;
if (read(tfd, &touch_c, 1) == 1 &&
lseek(tfd, (off_t)0, 0) == 0 &&
write(tfd, &touch_c, 1) != 1) {
printf("%s: cannot touch %s\n", progname,
tfname);
tfname[inchar]++;
cleanup(0);
}
(void) close(tfd);
}
if (link(tfname, cfname) < 0) {
printf("%s: cannot rename %s\n", progname, cfname);
tfname[inchar]++;
cleanup(0);
}
unlink(tfname);
seteuid(uid);
if (qflag) /* just q things up */
exit(0);
if (!startdaemon(pp))
printf("jobs queued, but cannot start daemon.\n");
exit(0);
}
cleanup(0);
return (1);
/* NOTREACHED */
}
/*
* Create the file n and copy from file descriptor f.
*/
static void
copy(const struct printer *pp, int f, const char n[])
{
register int fd, i, nr, nc;
char buf[BUFSIZ];
if (format == 'p')
card('T', title ? title : n);
for (i = 0; i < ncopies; i++)
card(format, &dfname[inchar-2]);
card('U', &dfname[inchar-2]);
card('N', n);
fd = nfile(dfname);
nr = nc = 0;
while ((i = read(f, buf, BUFSIZ)) > 0) {
if (write(fd, buf, i) != i) {
printf("%s: %s: temp file write error\n", progname, n);
break;
}
nc += i;
if (nc >= BUFSIZ) {
nc -= BUFSIZ;
nr++;
if (pp->max_blocks > 0 && nr > pp->max_blocks) {
printf("%s: %s: copy file is too large\n",
progname, n);
break;
}
}
}
(void) close(fd);
if (nc==0 && nr==0)
printf("%s: %s: empty input file\n", progname,
f ? n : "stdin");
else
nact++;
}
/*
* Try and link the file to dfname. Return a pointer to the full
* path name if successful.
*/
static const char *
linked(const char *file)
{
register char *cp;
static char buf[MAXPATHLEN];
register int ret;
if (*file != '/') {
if (getcwd(buf, sizeof(buf)) == NULL)
return(NULL);
while (file[0] == '.') {
switch (file[1]) {
case '/':
file += 2;
continue;
case '.':
if (file[2] == '/') {
if ((cp = strrchr(buf, '/')) != NULL)
*cp = '\0';
file += 3;
continue;
}
}
break;
}
strncat(buf, "/", sizeof(buf) - strlen(buf) - 1);
strncat(buf, file, sizeof(buf) - strlen(buf) - 1);
file = buf;
}
seteuid(euid);
ret = symlink(file, dfname);
seteuid(uid);
return(ret ? NULL : file);
}
/*
* Put a line into the control file.
*/
static void
card(int c, const char *p2)
{
char buf[BUFSIZ];
register char *p1 = buf;
size_t len = 2;
*p1++ = c;
while ((c = *p2++) != '\0' && len < sizeof(buf)) {
*p1++ = (c == '\n') ? ' ' : c;
len++;
}
*p1++ = '\n';
write(tfd, buf, len);
}
/*
* Create a new file in the spool directory.
*/
static int
nfile(char *n)
{
register int f;
int oldumask = umask(0); /* should block signals */
seteuid(euid);
f = open(n, O_WRONLY | O_EXCL | O_CREAT, FILMOD);
(void) umask(oldumask);
if (f < 0) {
printf("%s: cannot create %s\n", progname, n);
cleanup(0);
}
if (fchown(f, userid, -1) < 0) {
printf("%s: cannot chown %s\n", progname, n);
cleanup(0); /* cleanup does exit */
}
seteuid(uid);
if (++n[inchar] > 'z') {
if (++n[inchar-2] == 't') {
printf("too many files - break up the job\n");
cleanup(0);
}
n[inchar] = 'A';
} else if (n[inchar] == '[')
n[inchar] = 'a';
return(f);
}
/*
* Cleanup after interrupts and errors.
*/
static void
cleanup(int signo __unused)
{
register int i;
signal(SIGHUP, SIG_IGN);
signal(SIGINT, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
signal(SIGTERM, SIG_IGN);
i = inchar;
seteuid(euid);
if (tfname)
do
unlink(tfname);
while (tfname[i]-- != 'A');
if (cfname)
do
unlink(cfname);
while (cfname[i]-- != 'A');
if (dfname)
do {
do
unlink(dfname);
while (dfname[i]-- != 'A');
dfname[i] = 'z';
} while (dfname[i-2]-- != 'd');
exit(1);
}
/*
* Test to see if this is a printable file.
* Return -1 if it is not, 0 if its printable, and 1 if
* we should remove it after printing.
*/
static int
test(const char *file)
{
struct exec execb;
size_t dlen;
int fd;
char *cp, *dirpath;
if (access(file, 4) < 0) {
printf("%s: cannot access %s\n", progname, file);
return(-1);
}
if (stat(file, &statb) < 0) {
printf("%s: cannot stat %s\n", progname, file);
return(-1);
}
if ((statb.st_mode & S_IFMT) == S_IFDIR) {
printf("%s: %s is a directory\n", progname, file);
return(-1);
}
if (statb.st_size == 0) {
printf("%s: %s is an empty file\n", progname, file);
return(-1);
}
if ((fd = open(file, O_RDONLY)) < 0) {
printf("%s: cannot open %s\n", progname, file);
return(-1);
}
/*
* XXX Shall we add a similar test for ELF?
*/
if (read(fd, &execb, sizeof(execb)) == sizeof(execb) &&
!N_BADMAG(execb)) {
printf("%s: %s is an executable program", progname, file);
goto error1;
}
(void) close(fd);
if (rflag) {
/*
* aside: note that 'cp' is technically a 'const char *'
* (because it points into 'file'), even though strrchr
* returns a value of type 'char *'.
*/
if ((cp = strrchr(file, '/')) == NULL) {
if (checkwriteperm(file,".") == 0)
return(1);
} else {
if (cp == file) {
fd = checkwriteperm(file,"/");
} else {
/* strlcpy will change the '/' to '\0' */
dlen = cp - file + 1;
dirpath = malloc(dlen);
strlcpy(dirpath, file, dlen);
fd = checkwriteperm(file, dirpath);
free(dirpath);
}
if (fd == 0)
return(1);
}
printf("%s: %s: is not removable by you\n", progname, file);
}
return(0);
error1:
printf(" and is unprintable\n");
(void) close(fd);
return(-1);
}
static int
checkwriteperm(const char *file, const char *directory)
{
struct stat stats;
if (access(directory, W_OK) == 0) {
stat(directory, &stats);
if (stats.st_mode & S_ISVTX) {
stat(file, &stats);
if(stats.st_uid == userid) {
return(0);
}
} else return(0);
}
return(-1);
}
/*
* itoa - integer to string conversion
*/
static char *
itoa(int i)
{
static char b[10] = "########";
register char *p;
p = &b[8];
do
*p-- = i%10 + '0';
while (i /= 10);
return(++p);
}
/*
* Perform lookup for printer name or abbreviation --
*/
static void
chkprinter(const char *ptrname, struct printer *pp)
{
int status;
init_printer(pp);
status = getprintcap(ptrname, pp);
switch(status) {
case PCAPERR_OSERR:
case PCAPERR_TCLOOP:
errx(1, "%s: %s", ptrname, pcaperr(status));
case PCAPERR_NOTFOUND:
errx(1, "%s: unknown printer", ptrname);
case PCAPERR_TCOPEN:
warnx("%s: unresolved tc= reference(s)", ptrname);
}
}
/*
* Tell the user what we wanna get.
*/
static void
usage(void)
{
fprintf(stderr, "%s\n",
"usage: lpr [-Pprinter] [-#num] [-C class] [-J job] [-T title] [-U user]\n"
"\t[-Z daemon-options] [-i[numcols]] [-i[numcols]] [-1234 font]\n"
"\t[-L locale] [-wnum] [-cdfghlnmprstv] [name ...]");
exit(1);
}
/*
* Make the temp files.
*/
static void
mktemps(const struct printer *pp)
{
register int len, fd, n;
register char *cp;
char buf[BUFSIZ];
(void) snprintf(buf, sizeof(buf), "%s/.seq", pp->spool_dir);
seteuid(euid);
if ((fd = open(buf, O_RDWR|O_CREAT, 0661)) < 0) {
printf("%s: cannot create %s\n", progname, buf);
exit(1);
}
if (flock(fd, LOCK_EX)) {
printf("%s: cannot lock %s\n", progname, buf);
exit(1);
}
seteuid(uid);
n = 0;
if ((len = read(fd, buf, sizeof(buf))) > 0) {
for (cp = buf; len--; ) {
if (*cp < '0' || *cp > '9')
break;
n = n * 10 + (*cp++ - '0');
}
}
len = strlen(pp->spool_dir) + strlen(local_host) + 8;
tfname = lmktemp(pp, "tf", n, len);
cfname = lmktemp(pp, "cf", n, len);
dfname = lmktemp(pp, "df", n, len);
inchar = strlen(pp->spool_dir) + 3;
n = (n + 1) % 1000;
(void) lseek(fd, (off_t)0, 0);
snprintf(buf, sizeof(buf), "%03d\n", n);
(void) write(fd, buf, strlen(buf));
(void) close(fd); /* unlocks as well */
}
/*
* Make a temp file name.
*/
static char *
lmktemp(const struct printer *pp, const char *id, int num, int len)
{
register char *s;
if ((s = malloc(len)) == NULL)
errx(1, "out of memory");
(void) snprintf(s, len, "%s/%sA%03d%s", pp->spool_dir, id, num,
local_host);
return(s);
}