read.c

/*-
 * Copyright (c) 2007 Kai Wang
 * Copyright (c) 2007 Tim Kientzle
 * 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
 *    in this position and unchanged.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
 */

#include <sys/queue.h>
#include <sys/stat.h>

#include <archive.h>
#include <archive_entry.h>
#include <assert.h>
#include <errno.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "ar.h"

ELFTC_VCSID("$Id: read.c 3629 2018-09-30 19:26:28Z jkoshy $");

/*
 * Handle read modes: 'x', 't' and 'p'.
 *
 * Returns EXIT_SUCCESS if all operations completed successfully or returns
 * EXIT_FAILURE otherwise.
 */
int
ar_read_archive(struct bsdar *bsdar, int mode)
{
	FILE			 *out;
	struct archive		 *a;
	struct archive_entry	 *entry;
	struct stat		  sb;
	struct tm		 *tp;
	const char		 *bname;
	const char		 *name;
	mode_t			  md;
	size_t			  size;
	time_t			  mtime;
	uid_t			  uid;
	gid_t			  gid;
	char			**av;
	char			  buf[25];
	int			  found;
	int			  exitcode, i, flags, r;

	assert(mode == 'p' || mode == 't' || mode == 'x');

	if ((a = archive_read_new()) == NULL)
		bsdar_errc(bsdar, 0, "archive_read_new failed");
	archive_read_support_format_ar(a);
	AC(archive_read_open_filename(a, bsdar->filename, DEF_BLKSZ));

	exitcode = EXIT_SUCCESS;
	out = bsdar->output;

	for (;;) {
		r = archive_read_next_header(a, &entry);
		if (r == ARCHIVE_WARN || r == ARCHIVE_RETRY ||
		    r == ARCHIVE_FATAL)
			bsdar_warnc(bsdar, 0, "%s", archive_error_string(a));
		if (r == ARCHIVE_EOF || r == ARCHIVE_FATAL)
			break;
		if (r == ARCHIVE_RETRY) {
			bsdar_warnc(bsdar, 0, "Retrying...");
			continue;
		}

		if (archive_format(a) == ARCHIVE_FORMAT_AR_BSD)
			bsdar->options |= AR_BSD;
		else
			bsdar->options &= ~AR_BSD;

		if ((name = archive_entry_pathname(entry)) == NULL)
			break;

		/* Skip pseudo members. */
		if (bsdar_is_pseudomember(bsdar, name))
			continue;

		/* The ar(5) format only supports 'leaf' file names. */
		if (strchr(name, '/')) {
			bsdar_warnc(bsdar, 0, "ignoring entry: %s",
			    name);
			continue;
		}

		/*
		 * If we had been given a list of file names to process, check
		 * that the current entry is present in this list.
		 */
		if (bsdar->argc > 0) {
			found = 0;
			for(i = 0; i < bsdar->argc; i++) {
				av = &bsdar->argv[i];
				if (*av == NULL)
					continue;
				/*
				 * Per POSIX, only the basename of a file
				 * argument should be compared.
				 */
				if ((bname = basename(*av)) == NULL)
					bsdar_errc(bsdar, errno,
					    "basename failed");
				if (strcmp(bname, name) != 0)
					continue;

				*av = NULL;
				found = 1;
				break;
			}
			if (!found)
				continue;
		}

		if (mode == 't') {
			if (bsdar->options & AR_V) {
				md = archive_entry_mode(entry);
				uid = archive_entry_uid(entry);
				gid = archive_entry_gid(entry);
				size = archive_entry_size(entry);
				mtime = archive_entry_mtime(entry);
				(void)fprintf(out, "%s %6d/%-6d %8ju ",
				    bsdar_strmode(md) + 1, uid, gid,
				    (uintmax_t)size);
				tp = localtime(&mtime);
				(void)strftime(buf, sizeof(buf),
				    "%b %e %H:%M %Y", tp);
				(void)fprintf(out, "%s %s", buf, name);
			} else
				(void)fprintf(out, "%s", name);
			r = archive_read_data_skip(a);
			if (r == ARCHIVE_WARN || r == ARCHIVE_RETRY ||
			    r == ARCHIVE_FATAL) {
				(void)fprintf(out, "\n");
				bsdar_warnc(bsdar, 0, "%s",
				    archive_error_string(a));
			}

			if (r == ARCHIVE_FATAL)
				break;

			(void)fprintf(out, "\n");
		} else {
			/* mode == 'x' || mode = 'p' */
			if (mode == 'p') {
				if (bsdar->options & AR_V) {
					(void)fprintf(out, "\n<%s>\n\n",
					    name);
					fflush(out);
				}
				r = archive_read_data_into_fd(a, fileno(out));
			} else {
				/* mode == 'x' */
				if (stat(name, &sb) != 0) {
					if (errno != ENOENT) {
						bsdar_warnc(bsdar, errno,
						    "stat %s failed",
						    bsdar->filename);
						continue;
					}
				} else {
					/* stat success, file exist */
					if (bsdar->options & AR_CC)
						continue;
					if (bsdar->options & AR_U &&
					    archive_entry_mtime(entry) <=
					    sb.st_mtime)
						continue;
				}

				if (bsdar->options & AR_V)
					(void)fprintf(out, "x - %s\n", name);
				/* Basic path security flags. */
				flags = ARCHIVE_EXTRACT_SECURE_SYMLINKS |
	 			    ARCHIVE_EXTRACT_SECURE_NODOTDOT;
				if (bsdar->options & AR_O)
					flags |= ARCHIVE_EXTRACT_TIME;

				r = archive_read_extract(a, entry, flags);
			}

			if (r) {
				bsdar_warnc(bsdar, 0, "%s",
				    archive_error_string(a));
				exitcode = EXIT_FAILURE;
			}
		}
	}

	if (r == ARCHIVE_FATAL)
		exitcode = EXIT_FAILURE;

	AC(archive_read_close(a));
	ACV(archive_read_free(a));

	return (exitcode);
}