Generally use NULL instead of explicitly casting 0 to some pointer type.
[dragonfly.git] / usr.sbin / lpr / lpc / lpc.c
1 /*
2  * Copyright (c) 1983, 1993
3  *      The Regents of the University of California.  All rights reserved.
4  *
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *      This product includes software developed by the University of
17  *      California, Berkeley and its contributors.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * @(#) Copyright (c) 1983, 1993 The Regents of the University of California.  All rights reserved.
35  * @(#)lpc.c    8.3 (Berkeley) 4/28/95
36  * $FreeBSD: src/usr.sbin/lpr/lpc/lpc.c,v 1.13.2.11 2002/07/26 03:12:07 gad Exp $
37  * $DragonFly: src/usr.sbin/lpr/lpc/lpc.c,v 1.7 2006/01/14 22:58:18 corecode Exp $
38  */
39
40 #include <sys/param.h>
41
42 #include <ctype.h>
43 #include <dirent.h>
44 #include <err.h>
45 #include <grp.h>
46 #include <setjmp.h>
47 #include <signal.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <syslog.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <histedit.h>
54
55 #include "lp.h"
56 #include "lpc.h"
57 #include "extern.h"
58
59 #ifndef LPR_OPER
60 #define LPR_OPER        "operator"      /* group name of lpr operators */
61 #endif
62
63 /*
64  * lpc -- line printer control program
65  */
66
67 #define MAX_CMDLINE     200
68 #define MAX_MARGV       20
69 static int      fromatty;
70
71 static char     cmdline[MAX_CMDLINE];
72 static int      margc;
73 static char     *margv[MAX_MARGV];
74 uid_t           uid, euid;
75
76 int                      main(int _argc, char **_argv);
77 static void              cmdscanner(void);
78 static struct cmd       *getcmd(const char *_name);
79 static void              intr(int _signo);
80 static void              makeargv(void);
81 static int               ingroup(const char *_grname);
82
83 int
84 main(int argc, char **argv)
85 {
86         struct cmd *c;
87
88         euid = geteuid();
89         uid = getuid();
90         seteuid(uid);
91         progname = argv[0];
92         openlog("lpd", 0, LOG_LPR);
93
94         if (--argc > 0) {
95                 c = getcmd(*++argv);
96                 if (c == (struct cmd *)-1) {
97                         printf("?Ambiguous command\n");
98                         exit(1);
99                 }
100                 if (c == 0) {
101                         printf("?Invalid command\n");
102                         exit(1);
103                 }
104                 if ((c->c_opts & LPC_PRIVCMD) && getuid() &&
105                     ingroup(LPR_OPER) == 0) {
106                         printf("?Privileged command\n");
107                         exit(1);
108                 }
109                 if (c->c_generic != 0)
110                         generic(c->c_generic, c->c_opts, c->c_handler,
111                             argc, argv);
112                 else
113                         (*c->c_handler)(argc, argv);
114                 exit(0);
115         }
116         fromatty = isatty(fileno(stdin));
117         if (!fromatty)
118                 signal(SIGINT, intr);
119         for (;;) {
120                 cmdscanner();
121         }
122 }
123
124 static void
125 intr(int signo __unused)
126 {
127         /* (the '__unused' is just to avoid a compile-time warning) */
128         exit(0);
129 }
130
131 static const char *
132 lpc_prompt(void)
133 {
134         return ("lpc> ");
135 }
136
137 /*
138  * Command parser.
139  */
140 static void
141 cmdscanner(void)
142 {
143         struct cmd *c;
144         static EditLine *el;
145         static History *hist;
146         static HistEvent he;
147         size_t len;
148         int num;
149         const char *bp;
150
151         num = 0;
152         bp = NULL;
153         el = NULL;
154         hist = NULL;
155         for (;;) {
156                 if (fromatty) {
157                         if (!el) {
158                                 el = el_init("lpc", stdin, stdout, stderr);
159                                 hist = history_init();
160                                 history(hist, &he, H_SETSIZE, 100);
161                                 el_set(el, EL_HIST, history, hist);
162                                 el_set(el, EL_EDITOR, "emacs");
163                                 el_set(el, EL_PROMPT, lpc_prompt);
164                                 el_set(el, EL_SIGNAL, 1);
165                                 el_source(el, NULL);
166                                 /*
167                                  * EditLine init may call 'cgetset()' to set a
168                                  * capability-db meant for termcap (eg: to set
169                                  * terminal type 'xterm').  Reset that now, or
170                                  * that same db-information will be used for
171                                  * printcap (giving us an "xterm" printer, with
172                                  * all kinds of invalid capabilities...).
173                                  */
174                                 cgetset(NULL);
175                         }
176                         if ((bp = el_gets(el, &num)) == NULL || num == 0)
177                                 quit(0, NULL);
178
179                         len = (num > MAX_CMDLINE -1) ? MAX_CMDLINE -1 : num;
180                         memcpy(cmdline, bp, len);
181                         cmdline[len] = 0; 
182                         history(hist, &he, H_ENTER, bp);
183
184                 } else {
185                         if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
186                                 quit(0, NULL);
187                         if (cmdline[0] == 0 || cmdline[0] == '\n')
188                                 break;
189                 }
190
191                 makeargv();
192                 if (margc == 0)
193                         continue;
194                 if (el != NULL && el_parse(el, margc, (const char **)margv) != -1)
195                         continue;
196
197                 c = getcmd(margv[0]);
198                 if (c == (struct cmd *)-1) {
199                         printf("?Ambiguous command\n");
200                         continue;
201                 }
202                 if (c == 0) {
203                         printf("?Invalid command\n");
204                         continue;
205                 }
206                 if ((c->c_opts & LPC_PRIVCMD) && getuid() &&
207                     ingroup(LPR_OPER) == 0) {
208                         printf("?Privileged command\n");
209                         continue;
210                 }
211
212                 /*
213                  * Two different commands might have the same generic rtn
214                  * (eg: "clean" and "tclean"), and just use different
215                  * handler routines for distinct command-setup.  The handler
216                  * routine might also be set on a generic routine for
217                  * initial parameter processing.
218                  */
219                 if (c->c_generic != 0)
220                         generic(c->c_generic, c->c_opts, c->c_handler,
221                             margc, margv);
222                 else
223                         (*c->c_handler)(margc, margv);
224         }
225 }
226
227 static struct cmd *
228 getcmd(const char *name)
229 {
230         const char *p, *q;
231         struct cmd *c, *found;
232         int nmatches, longest;
233
234         longest = 0;
235         nmatches = 0;
236         found = 0;
237         for (c = cmdtab; (p = c->c_name); c++) {
238                 for (q = name; *q == *p++; q++)
239                         if (*q == 0)            /* exact match? */
240                                 return(c);
241                 if (!*q) {                      /* the name was a prefix */
242                         if (q - name > longest) {
243                                 longest = q - name;
244                                 nmatches = 1;
245                                 found = c;
246                         } else if (q - name == longest)
247                                 nmatches++;
248                 }
249         }
250         if (nmatches > 1)
251                 return((struct cmd *)-1);
252         return(found);
253 }
254
255 /*
256  * Slice a string up into argc/argv.
257  */
258 static void
259 makeargv(void)
260 {
261         char *cp;
262         char **argp = margv;
263         int n = 0;
264
265         margc = 0;
266         for (cp = cmdline; *cp && (size_t)(cp - cmdline) < sizeof(cmdline) &&
267             n < MAX_MARGV -1; n++) {
268                 while (isspace(*cp))
269                         cp++;
270                 if (*cp == '\0')
271                         break;
272                 *argp++ = cp;
273                 margc += 1;
274                 while (*cp != '\0' && !isspace(*cp))
275                         cp++;
276                 if (*cp == '\0')
277                         break;
278                 *cp++ = '\0';
279         }
280         *argp++ = 0;
281 }
282
283 #define HELPINDENT (sizeof ("directory"))
284
285 /*
286  * Help command.
287  */
288 void
289 help(int argc, char **argv)
290 {
291         struct cmd *c;
292
293         if (argc == 1) {
294                 int i, j, w;
295                 int columns, width = 0, lines;
296
297                 printf("Commands may be abbreviated.  Commands are:\n\n");
298                 for (c = cmdtab; c->c_name; c++) {
299                         int len = strlen(c->c_name);
300
301                         if (len > width)
302                                 width = len;
303                 }
304                 width = (width + 8) &~ 7;
305                 columns = 80 / width;
306                 if (columns == 0)
307                         columns = 1;
308                 lines = (NCMDS + columns - 1) / columns;
309                 for (i = 0; i < lines; i++) {
310                         for (j = 0; j < columns; j++) {
311                                 c = cmdtab + j * lines + i;
312                                 if (c->c_name)
313                                         printf("%s", c->c_name);
314                                 if (c + lines >= &cmdtab[NCMDS]) {
315                                         printf("\n");
316                                         break;
317                                 }
318                                 w = strlen(c->c_name);
319                                 while (w < width) {
320                                         w = (w + 8) &~ 7;
321                                         putchar('\t');
322                                 }
323                         }
324                 }
325                 return;
326         }
327         while (--argc > 0) {
328                 char *arg;
329
330                 arg = *++argv;
331                 c = getcmd(arg);
332                 if (c == (struct cmd *)-1)
333                         printf("?Ambiguous help command %s\n", arg);
334                 else if (c == NULL)
335                         printf("?Invalid help command %s\n", arg);
336                 else
337                         printf("%-*s\t%s\n", (int) HELPINDENT,
338                                 c->c_name, c->c_help);
339         }
340 }
341
342 /*
343  * return non-zero if the user is a member of the given group
344  */
345 static int
346 ingroup(const char *grname)
347 {
348         static struct group *gptr=NULL;
349         static int ngroups = 0;
350         static gid_t groups[NGROUPS];
351         gid_t gid;
352         int i;
353
354         if (gptr == NULL) {
355                 if ((gptr = getgrnam(grname)) == NULL) {
356                         warnx("warning: unknown group '%s'", grname);
357                         return(0);
358                 }
359                 ngroups = getgroups(NGROUPS, groups);
360                 if (ngroups < 0)
361                         err(1, "getgroups");
362         }
363         gid = gptr->gr_gid;
364         for (i = 0; i < ngroups; i++)
365                 if (gid == groups[i])
366                         return(1);
367         return(0);
368 }
369
370 /*
371  * Routine to get the information for a single printer (which will be
372  * called by the routines which implement individual commands).
373  * Note: This is for commands operating on a *single* printer.
374  */
375 struct printer *
376 setup_myprinter(char *pwanted, struct printer *pp, int sump_opts)
377 {
378         int cdres, cmdstatus;
379
380         init_printer(pp);
381         cmdstatus = getprintcap(pwanted, pp);
382         switch (cmdstatus) {
383         default:
384                 fatal(pp, "%s", pcaperr(cmdstatus));
385                 /* NOTREACHED */
386         case PCAPERR_NOTFOUND:
387                 printf("unknown printer %s\n", pwanted);
388                 return (NULL);
389         case PCAPERR_TCOPEN:
390                 printf("warning: %s: unresolved tc= reference(s)", pwanted);
391                 break;
392         case PCAPERR_SUCCESS:
393                 break;
394         }
395         if ((sump_opts & SUMP_NOHEADER) == 0)
396                 printf("%s:\n", pp->printer);
397
398         if (sump_opts & SUMP_CHDIR_SD) {
399                 seteuid(euid);
400                 cdres = chdir(pp->spool_dir);
401                 seteuid(uid);
402                 if (cdres < 0) {
403                         printf("\tcannot chdir to %s\n", pp->spool_dir);
404                         free_printer(pp);
405                         return (NULL);
406                 }
407         }
408
409         return (pp);
410 }