freebsd-skq/usr.sbin/lpr/lpc/lpc.c
eadler 4bc19b04c5 Check the return error of set[ug]id. While this can never fail in the
current version of FreeBSD, this isn't guarenteed by the API.  Custom
security modules, or future implementations of the setuid and setgid
may fail.

PR:		bin/172289
PR:		bin/172290
PR:		bin/172291
Submittud by:	Erik Cederstrand <erik@cederstrand.dk>
Discussed by:	freebsd-security
Approved by:	cperciva
MFC after:	1 week
2012-10-22 03:31:22 +00:00

420 lines
9.5 KiB
C

/*
* Copyright (c) 1983, 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.
* 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, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#if 0
#ifndef lint
static char sccsid[] = "@(#)lpc.c 8.3 (Berkeley) 4/28/95";
#endif /* not lint */
#endif
#include "lp.cdefs.h" /* A cross-platform version of <sys/cdefs.h> */
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <grp.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <string.h>
#include <unistd.h>
#include <histedit.h>
#include "lp.h"
#include "lpc.h"
#include "extern.h"
#ifndef LPR_OPER
#define LPR_OPER "operator" /* group name of lpr operators */
#endif
/*
* lpc -- line printer control program
*/
#define MAX_CMDLINE 200
#define MAX_MARGV 20
static int fromatty;
static char cmdline[MAX_CMDLINE];
static int margc;
static char *margv[MAX_MARGV];
uid_t uid, euid;
int main(int _argc, char *_argv[]);
static void cmdscanner(void);
static struct cmd *getcmd(const char *_name);
static void intr(int _signo);
static void makeargv(void);
static int ingroup(const char *_grname);
int
main(int argc, char *argv[])
{
register struct cmd *c;
euid = geteuid();
uid = getuid();
PRIV_END
progname = argv[0];
openlog("lpd", 0, LOG_LPR);
if (--argc > 0) {
c = getcmd(*++argv);
if (c == (struct cmd *)-1) {
printf("?Ambiguous command\n");
exit(1);
}
if (c == 0) {
printf("?Invalid command\n");
exit(1);
}
if ((c->c_opts & LPC_PRIVCMD) && getuid() &&
ingroup(LPR_OPER) == 0) {
printf("?Privileged command\n");
exit(1);
}
if (c->c_generic != 0)
generic(c->c_generic, c->c_opts, c->c_handler,
argc, argv);
else
(*c->c_handler)(argc, argv);
exit(0);
}
fromatty = isatty(fileno(stdin));
if (!fromatty)
signal(SIGINT, intr);
for (;;) {
cmdscanner();
}
}
static void
intr(int signo __unused)
{
/* (the '__unused' is just to avoid a compile-time warning) */
exit(0);
}
static const char *
lpc_prompt(void)
{
return ("lpc> ");
}
/*
* Command parser.
*/
static void
cmdscanner(void)
{
register struct cmd *c;
static EditLine *el;
static History *hist;
HistEvent he;
size_t len;
int num;
const char *bp;
num = 0;
bp = NULL;
el = NULL;
hist = NULL;
for (;;) {
if (fromatty) {
if (!el) {
el = el_init("lpc", stdin, stdout, stderr);
hist = history_init();
history(hist, &he, H_SETSIZE, 100);
el_set(el, EL_HIST, history, hist);
el_set(el, EL_EDITOR, "emacs");
el_set(el, EL_PROMPT, lpc_prompt);
el_set(el, EL_SIGNAL, 1);
el_source(el, NULL);
/*
* EditLine init may call 'cgetset()' to set a
* capability-db meant for termcap (eg: to set
* terminal type 'xterm'). Reset that now, or
* that same db-information will be used for
* printcap (giving us an "xterm" printer, with
* all kinds of invalid capabilities...).
*/
cgetset(NULL);
}
if ((bp = el_gets(el, &num)) == NULL || num == 0)
quit(0, NULL);
len = (num > MAX_CMDLINE - 1) ? MAX_CMDLINE - 1 : num;
memcpy(cmdline, bp, len);
cmdline[len] = 0;
history(hist, &he, H_ENTER, bp);
} else {
if (fgets(cmdline, MAX_CMDLINE, stdin) == NULL)
quit(0, NULL);
if (cmdline[0] == 0 || cmdline[0] == '\n')
break;
}
makeargv();
if (margc == 0)
continue;
if (el != NULL && el_parse(el, margc, margv) != -1)
continue;
c = getcmd(margv[0]);
if (c == (struct cmd *)-1) {
printf("?Ambiguous command\n");
continue;
}
if (c == 0) {
printf("?Invalid command\n");
continue;
}
if ((c->c_opts & LPC_PRIVCMD) && getuid() &&
ingroup(LPR_OPER) == 0) {
printf("?Privileged command\n");
continue;
}
/*
* Two different commands might have the same generic rtn
* (eg: "clean" and "tclean"), and just use different
* handler routines for distinct command-setup. The handler
* routine might also be set on a generic routine for
* initial parameter processing.
*/
if (c->c_generic != 0)
generic(c->c_generic, c->c_opts, c->c_handler,
margc, margv);
else
(*c->c_handler)(margc, margv);
}
}
static struct cmd *
getcmd(const char *name)
{
register const char *p, *q;
register struct cmd *c, *found;
register int nmatches, longest;
longest = 0;
nmatches = 0;
found = 0;
for (c = cmdtab; (p = c->c_name); c++) {
for (q = name; *q == *p++; q++)
if (*q == 0) /* exact match? */
return(c);
if (!*q) { /* the name was a prefix */
if (q - name > longest) {
longest = q - name;
nmatches = 1;
found = c;
} else if (q - name == longest)
nmatches++;
}
}
if (nmatches > 1)
return((struct cmd *)-1);
return(found);
}
/*
* Slice a string up into argc/argv.
*/
static void
makeargv(void)
{
register char *cp;
register char **argp = margv;
register int n = 0;
margc = 0;
for (cp = cmdline; *cp && (size_t)(cp - cmdline) < sizeof(cmdline) &&
n < MAX_MARGV - 1; n++) {
while (isspace(*cp))
cp++;
if (*cp == '\0')
break;
*argp++ = cp;
margc += 1;
while (*cp != '\0' && !isspace(*cp))
cp++;
if (*cp == '\0')
break;
*cp++ = '\0';
}
*argp++ = 0;
}
#define HELPINDENT (sizeof ("directory"))
/*
* Help command.
*/
void
help(int argc, char *argv[])
{
register struct cmd *c;
if (argc == 1) {
register int i, j, w;
int columns, width = 0, lines;
printf("Commands may be abbreviated. Commands are:\n\n");
for (c = cmdtab; c->c_name; c++) {
int len = strlen(c->c_name);
if (len > width)
width = len;
}
width = (width + 8) &~ 7;
columns = 80 / width;
if (columns == 0)
columns = 1;
lines = (NCMDS + columns - 1) / columns;
for (i = 0; i < lines; i++) {
for (j = 0; j < columns; j++) {
c = cmdtab + j * lines + i;
if (c->c_name)
printf("%s", c->c_name);
if (c + lines >= &cmdtab[NCMDS]) {
printf("\n");
break;
}
w = strlen(c->c_name);
while (w < width) {
w = (w + 8) &~ 7;
putchar('\t');
}
}
}
return;
}
while (--argc > 0) {
register char *arg;
arg = *++argv;
c = getcmd(arg);
if (c == (struct cmd *)-1)
printf("?Ambiguous help command %s\n", arg);
else if (c == (struct cmd *)0)
printf("?Invalid help command %s\n", arg);
else
printf("%-*s\t%s\n", (int) HELPINDENT,
c->c_name, c->c_help);
}
}
/*
* return non-zero if the user is a member of the given group
*/
static int
ingroup(const char *grname)
{
static struct group *gptr=NULL;
static int ngroups = 0;
static long ngroups_max;
static gid_t *groups;
register gid_t gid;
register int i;
if (gptr == NULL) {
if ((gptr = getgrnam(grname)) == NULL) {
warnx("warning: unknown group '%s'", grname);
return(0);
}
ngroups_max = sysconf(_SC_NGROUPS_MAX);
if ((groups = malloc(sizeof(gid_t) * ngroups_max)) == NULL)
err(1, "malloc");
ngroups = getgroups(ngroups_max, groups);
if (ngroups < 0)
err(1, "getgroups");
}
gid = gptr->gr_gid;
for (i = 0; i < ngroups; i++)
if (gid == groups[i])
return(1);
return(0);
}
/*
* Routine to get the information for a single printer (which will be
* called by the routines which implement individual commands).
* Note: This is for commands operating on a *single* printer.
*/
struct printer *
setup_myprinter(char *pwanted, struct printer *pp, int sump_opts)
{
int cdres, cmdstatus;
init_printer(pp);
cmdstatus = getprintcap(pwanted, pp);
switch (cmdstatus) {
default:
fatal(pp, "%s", pcaperr(cmdstatus));
/* NOTREACHED */
case PCAPERR_NOTFOUND:
printf("unknown printer %s\n", pwanted);
return (NULL);
case PCAPERR_TCOPEN:
printf("warning: %s: unresolved tc= reference(s)", pwanted);
break;
case PCAPERR_SUCCESS:
break;
}
if ((sump_opts & SUMP_NOHEADER) == 0)
printf("%s:\n", pp->printer);
if (sump_opts & SUMP_CHDIR_SD) {
PRIV_START
cdres = chdir(pp->spool_dir);
PRIV_END
if (cdres < 0) {
printf("\tcannot chdir to %s\n", pp->spool_dir);
free_printer(pp);
return (NULL);
}
}
return (pp);
}