xref: /freebsd/bin/cat/cat.c (revision 6e8062c855d19d1cbbd65b6843449f22791c3a0a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kevin Fall.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. 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 
35 #if 0
36 #ifndef lint
37 static char const copyright[] =
38 "@(#) Copyright (c) 1989, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 #endif
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)cat.c	8.2 (Berkeley) 4/27/95";
46 #endif
47 #endif /* not lint */
48 #include <sys/cdefs.h>
49 __FBSDID("$FreeBSD$");
50 
51 #include <sys/capsicum.h>
52 #include <sys/param.h>
53 #include <sys/stat.h>
54 #ifndef NO_UDOM_SUPPORT
55 #include <sys/socket.h>
56 #include <sys/un.h>
57 #include <netdb.h>
58 #endif
59 
60 #include <capsicum_helpers.h>
61 #include <ctype.h>
62 #include <err.h>
63 #include <errno.h>
64 #include <fcntl.h>
65 #include <locale.h>
66 #include <stdio.h>
67 #include <stdlib.h>
68 #include <string.h>
69 #include <unistd.h>
70 #include <wchar.h>
71 #include <wctype.h>
72 
73 #include <libcasper.h>
74 #include <casper/cap_fileargs.h>
75 #include <casper/cap_net.h>
76 
77 static int bflag, eflag, lflag, nflag, sflag, tflag, vflag;
78 static int rval;
79 static const char *filename;
80 static fileargs_t *fa;
81 
82 static void usage(void) __dead2;
83 static void scanfiles(char *argv[], int cooked);
84 #ifndef BOOTSTRAP_CAT
85 static void cook_cat(FILE *);
86 #endif
87 static void raw_cat(int);
88 
89 #ifndef NO_UDOM_SUPPORT
90 static cap_channel_t *capnet;
91 
92 static int udom_open(const char *path, int flags);
93 #endif
94 
95 /*
96  * Memory strategy threshold, in pages: if physmem is larger than this,
97  * use a large buffer.
98  */
99 #define	PHYSPAGES_THRESHOLD (32 * 1024)
100 
101 /* Maximum buffer size in bytes - do not allow it to grow larger than this. */
102 #define	BUFSIZE_MAX (2 * 1024 * 1024)
103 
104 /*
105  * Small (default) buffer size in bytes. It's inefficient for this to be
106  * smaller than MAXPHYS.
107  */
108 #define	BUFSIZE_SMALL (MAXPHYS)
109 
110 
111 /*
112  * For the bootstrapped cat binary (needed for locked appending to METALOG), we
113  * disable all flags except -l and -u to avoid non-portable function calls.
114  * In the future we may instead want to write a small portable bootstrap tool
115  * that locks the output file before writing to it. However, for now
116  * bootstrapping cat without multibyte support is the simpler solution.
117  */
118 #ifdef BOOTSTRAP_CAT
119 #define SUPPORTED_FLAGS "lu"
120 #else
121 #define SUPPORTED_FLAGS "belnstuv"
122 #endif
123 
124 #ifndef NO_UDOM_SUPPORT
125 static void
126 init_casper_net(cap_channel_t *casper)
127 {
128 	cap_net_limit_t *limit;
129 	int familylimit;
130 
131 	capnet = cap_service_open(casper, "system.net");
132 	if (capnet == NULL)
133 		err(EXIT_FAILURE, "unable to create network service");
134 
135 	limit = cap_net_limit_init(capnet, CAPNET_NAME2ADDR |
136 	    CAPNET_CONNECTDNS);
137 	if (limit == NULL)
138 		err(EXIT_FAILURE, "unable to create limits");
139 
140 	familylimit = AF_LOCAL;
141 	cap_net_limit_name2addr_family(limit, &familylimit, 1);
142 
143 	if (cap_net_limit(limit) < 0)
144 		err(EXIT_FAILURE, "unable to apply limits");
145 }
146 #endif
147 
148 static void
149 init_casper(int argc, char *argv[])
150 {
151 	cap_channel_t *casper;
152 	cap_rights_t rights;
153 
154 	casper = cap_init();
155 	if (casper == NULL)
156 		err(EXIT_FAILURE, "unable to create Casper");
157 
158 	fa = fileargs_cinit(casper, argc, argv, O_RDONLY, 0,
159 	    cap_rights_init(&rights, CAP_READ | CAP_FSTAT | CAP_FCNTL),
160 	    FA_OPEN | FA_REALPATH);
161 	if (fa == NULL)
162 		err(EXIT_FAILURE, "unable to create fileargs");
163 
164 #ifndef NO_UDOM_SUPPORT
165 	init_casper_net(casper);
166 #endif
167 
168 	cap_close(casper);
169 }
170 
171 int
172 main(int argc, char *argv[])
173 {
174 	int ch;
175 	struct flock stdout_lock;
176 
177 	setlocale(LC_CTYPE, "");
178 
179 	while ((ch = getopt(argc, argv, SUPPORTED_FLAGS)) != -1)
180 		switch (ch) {
181 		case 'b':
182 			bflag = nflag = 1;	/* -b implies -n */
183 			break;
184 		case 'e':
185 			eflag = vflag = 1;	/* -e implies -v */
186 			break;
187 		case 'l':
188 			lflag = 1;
189 			break;
190 		case 'n':
191 			nflag = 1;
192 			break;
193 		case 's':
194 			sflag = 1;
195 			break;
196 		case 't':
197 			tflag = vflag = 1;	/* -t implies -v */
198 			break;
199 		case 'u':
200 			setbuf(stdout, NULL);
201 			break;
202 		case 'v':
203 			vflag = 1;
204 			break;
205 		default:
206 			usage();
207 		}
208 	argv += optind;
209 	argc -= optind;
210 
211 	if (lflag) {
212 		stdout_lock.l_len = 0;
213 		stdout_lock.l_start = 0;
214 		stdout_lock.l_type = F_WRLCK;
215 		stdout_lock.l_whence = SEEK_SET;
216 		if (fcntl(STDOUT_FILENO, F_SETLKW, &stdout_lock) == -1)
217 			err(EXIT_FAILURE, "stdout");
218 	}
219 
220 	init_casper(argc, argv);
221 
222 	caph_cache_catpages();
223 
224 	if (caph_enter_casper() < 0)
225 		err(EXIT_FAILURE, "capsicum");
226 
227 	if (bflag || eflag || nflag || sflag || tflag || vflag)
228 		scanfiles(argv, 1);
229 	else
230 		scanfiles(argv, 0);
231 	if (fclose(stdout))
232 		err(1, "stdout");
233 	exit(rval);
234 	/* NOTREACHED */
235 }
236 
237 static void
238 usage(void)
239 {
240 
241 	fprintf(stderr, "usage: cat [-" SUPPORTED_FLAGS "] [file ...]\n");
242 	exit(1);
243 	/* NOTREACHED */
244 }
245 
246 static void
247 scanfiles(char *argv[], int cooked __unused)
248 {
249 	int fd, i;
250 	char *path;
251 #ifndef BOOTSTRAP_CAT
252 	FILE *fp;
253 #endif
254 
255 	i = 0;
256 	fd = -1;
257 	while ((path = argv[i]) != NULL || i == 0) {
258 		if (path == NULL || strcmp(path, "-") == 0) {
259 			filename = "stdin";
260 			fd = STDIN_FILENO;
261 		} else {
262 			filename = path;
263 			fd = fileargs_open(fa, path);
264 #ifndef NO_UDOM_SUPPORT
265 			if (fd < 0 && errno == EOPNOTSUPP)
266 				fd = udom_open(path, O_RDONLY);
267 #endif
268 		}
269 		if (fd < 0) {
270 			warn("%s", path);
271 			rval = 1;
272 #ifndef BOOTSTRAP_CAT
273 		} else if (cooked) {
274 			if (fd == STDIN_FILENO)
275 				cook_cat(stdin);
276 			else {
277 				fp = fdopen(fd, "r");
278 				cook_cat(fp);
279 				fclose(fp);
280 			}
281 #endif
282 		} else {
283 			raw_cat(fd);
284 			if (fd != STDIN_FILENO)
285 				close(fd);
286 		}
287 		if (path == NULL)
288 			break;
289 		++i;
290 	}
291 }
292 
293 #ifndef BOOTSTRAP_CAT
294 static void
295 cook_cat(FILE *fp)
296 {
297 	int ch, gobble, line, prev;
298 	wint_t wch;
299 
300 	/* Reset EOF condition on stdin. */
301 	if (fp == stdin && feof(stdin))
302 		clearerr(stdin);
303 
304 	line = gobble = 0;
305 	for (prev = '\n'; (ch = getc(fp)) != EOF; prev = ch) {
306 		if (prev == '\n') {
307 			if (sflag) {
308 				if (ch == '\n') {
309 					if (gobble)
310 						continue;
311 					gobble = 1;
312 				} else
313 					gobble = 0;
314 			}
315 			if (nflag) {
316 				if (!bflag || ch != '\n') {
317 					(void)fprintf(stdout, "%6d\t", ++line);
318 					if (ferror(stdout))
319 						break;
320 				} else if (eflag) {
321 					(void)fprintf(stdout, "%6s\t", "");
322 					if (ferror(stdout))
323 						break;
324 				}
325 			}
326 		}
327 		if (ch == '\n') {
328 			if (eflag && putchar('$') == EOF)
329 				break;
330 		} else if (ch == '\t') {
331 			if (tflag) {
332 				if (putchar('^') == EOF || putchar('I') == EOF)
333 					break;
334 				continue;
335 			}
336 		} else if (vflag) {
337 			(void)ungetc(ch, fp);
338 			/*
339 			 * Our getwc(3) doesn't change file position
340 			 * on error.
341 			 */
342 			if ((wch = getwc(fp)) == WEOF) {
343 				if (ferror(fp) && errno == EILSEQ) {
344 					clearerr(fp);
345 					/* Resync attempt. */
346 					memset(&fp->_mbstate, 0, sizeof(mbstate_t));
347 					if ((ch = getc(fp)) == EOF)
348 						break;
349 					wch = ch;
350 					goto ilseq;
351 				} else
352 					break;
353 			}
354 			if (!iswascii(wch) && !iswprint(wch)) {
355 ilseq:
356 				if (putchar('M') == EOF || putchar('-') == EOF)
357 					break;
358 				wch = toascii(wch);
359 			}
360 			if (iswcntrl(wch)) {
361 				ch = toascii(wch);
362 				ch = (ch == '\177') ? '?' : (ch | 0100);
363 				if (putchar('^') == EOF || putchar(ch) == EOF)
364 					break;
365 				continue;
366 			}
367 			if (putwchar(wch) == WEOF)
368 				break;
369 			ch = -1;
370 			continue;
371 		}
372 		if (putchar(ch) == EOF)
373 			break;
374 	}
375 	if (ferror(fp)) {
376 		warn("%s", filename);
377 		rval = 1;
378 		clearerr(fp);
379 	}
380 	if (ferror(stdout))
381 		err(1, "stdout");
382 }
383 #endif /* BOOTSTRAP_CAT */
384 
385 static void
386 raw_cat(int rfd)
387 {
388 	long pagesize;
389 	int off, wfd;
390 	ssize_t nr, nw;
391 	static size_t bsize;
392 	static char *buf = NULL;
393 	struct stat sbuf;
394 
395 	wfd = fileno(stdout);
396 	if (buf == NULL) {
397 		if (fstat(wfd, &sbuf))
398 			err(1, "stdout");
399 		if (S_ISREG(sbuf.st_mode)) {
400 			/* If there's plenty of RAM, use a large copy buffer */
401 			if (sysconf(_SC_PHYS_PAGES) > PHYSPAGES_THRESHOLD)
402 				bsize = MIN(BUFSIZE_MAX, MAXPHYS * 8);
403 			else
404 				bsize = BUFSIZE_SMALL;
405 		} else {
406 			bsize = sbuf.st_blksize;
407 			pagesize = sysconf(_SC_PAGESIZE);
408 			if (pagesize > 0)
409 				bsize = MAX(bsize, (size_t)pagesize);
410 		}
411 		if ((buf = malloc(bsize)) == NULL)
412 			err(1, "malloc() failure of IO buffer");
413 	}
414 	while ((nr = read(rfd, buf, bsize)) > 0)
415 		for (off = 0; nr; nr -= nw, off += nw)
416 			if ((nw = write(wfd, buf + off, (size_t)nr)) < 0)
417 				err(1, "stdout");
418 	if (nr < 0) {
419 		warn("%s", filename);
420 		rval = 1;
421 	}
422 }
423 
424 #ifndef NO_UDOM_SUPPORT
425 
426 static int
427 udom_open(const char *path, int flags)
428 {
429 	struct addrinfo hints, *res, *res0;
430 	char rpath[PATH_MAX];
431 	int fd = -1;
432 	int error, serrno;
433 	cap_rights_t rights;
434 
435 	/*
436 	 * Construct the unix domain socket address and attempt to connect.
437 	 */
438 	bzero(&hints, sizeof(hints));
439 	hints.ai_family = AF_LOCAL;
440 
441 	if (fileargs_realpath(fa, path, rpath) == NULL)
442 		return (-1);
443 
444 	error = cap_getaddrinfo(capnet, rpath, NULL, &hints, &res0);
445 	if (error) {
446 		warn("%s", gai_strerror(error));
447 		errno = EINVAL;
448 		return (-1);
449 	}
450 	cap_rights_init(&rights, CAP_CONNECT, CAP_READ, CAP_WRITE,
451 	    CAP_SHUTDOWN, CAP_FSTAT, CAP_FCNTL);
452 	for (res = res0; res != NULL; res = res->ai_next) {
453 		fd = socket(res->ai_family, res->ai_socktype,
454 		    res->ai_protocol);
455 		if (fd < 0) {
456 			serrno = errno;
457 			freeaddrinfo(res0);
458 			errno = serrno;
459 			return (-1);
460 		}
461 		if (caph_rights_limit(fd, &rights) < 0) {
462 			serrno = errno;
463 			close(fd);
464 			freeaddrinfo(res0);
465 			errno = serrno;
466 			return (-1);
467 		}
468 		error = cap_connect(capnet, fd, res->ai_addr, res->ai_addrlen);
469 		if (error == 0)
470 			break;
471 		else {
472 			serrno = errno;
473 			close(fd);
474 			fd = -1;
475 		}
476 	}
477 	freeaddrinfo(res0);
478 
479 	/*
480 	 * handle the open flags by shutting down appropriate directions
481 	 */
482 	if (fd >= 0) {
483 		switch(flags & O_ACCMODE) {
484 		case O_RDONLY:
485 			cap_rights_clear(&rights, CAP_WRITE);
486 			if (shutdown(fd, SHUT_WR) == -1)
487 				warn(NULL);
488 			break;
489 		case O_WRONLY:
490 			cap_rights_clear(&rights, CAP_READ);
491 			if (shutdown(fd, SHUT_RD) == -1)
492 				warn(NULL);
493 			break;
494 		default:
495 			break;
496 		}
497 
498 		cap_rights_clear(&rights, CAP_CONNECT, CAP_SHUTDOWN);
499 		if (caph_rights_limit(fd, &rights) < 0) {
500 			serrno = errno;
501 			close(fd);
502 			errno = serrno;
503 			return (-1);
504 		}
505 	} else {
506 		errno = serrno;
507 	}
508 	return (fd);
509 }
510 
511 #endif
512