Initial import of libarchive.

What it is:
   A library for reading and writing various streaming archive
   formats, especially tar and cpio.  Being a library, it should
   be easy to incorporate into pkg_* tools, sysinstall, and any
   other place that needs to read or write such archives.

Features:
  * Full automatic detection of both compression and archive format.
  * Extensible internal architecture to make it easy to add new formats.
  * Support for "pax interchange format," a new POSIX-standard tar format
    that eliminates essentially all of the restrictions of historic formats.
  * BSD license

Thanks to: jkh for pushing me to start this work, gordon for
  encouraging me to commit it, bde for answering endless style
  questions, and many others for feedback and encouragement.

Status: Pretty good overall, though there are still a few rough edges and
  the library could always use more testing.  Feedback eagerly solicited.

1 files changed, 505 insertions, 0 deletions

diff --git a/lib/libarchive/archive_read.c b/lib/libarchive/archive_read.c
new file mode 100644
index 0000000..1c24d2d
--- /dev/null
+++ b/lib/libarchive/archive_read.c
@@ -0,0 +1,505 @@
+/*-
+ * Copyright (c) 2003-2004 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.
+ */
+
+/*
+ * This file contains the "essential" portions of the read API, that
+ * is, stuff that will probably always be used by any client that
+ * actually needs to read an archive.  Optional pieces have been, as
+ * far as possible, separated out into separate files to avoid
+ * needlessly bloating statically-linked clients.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#ifdef DMALLOC
+#include <dmalloc.h>
+#endif
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "archive.h"
+#include "archive_entry.h"
+#include "archive_private.h"
+
+static int	choose_decompressor(struct archive *, const void*, size_t);
+static int	choose_format(struct archive *);
+
+/*
+ * Allocate, initialize and return a struct archive object.
+ */
+struct archive *
+archive_read_new(void)
+{
+	struct archive	*a;
+	char		*nulls;
+
+	a = malloc(sizeof(*a));
+	memset(a, 0, sizeof(*a));
+
+	a->user_uid = geteuid();
+	a->magic = ARCHIVE_READ_MAGIC;
+	a->bytes_per_block = ARCHIVE_DEFAULT_BYTES_PER_BLOCK;
+
+	a->null_length = 1024;
+	nulls = malloc(a->null_length);
+	memset(nulls, 0, a->null_length);
+	a->nulls = nulls;
+
+	a->state = ARCHIVE_STATE_NEW;
+	a->entry = archive_entry_new();
+
+	/* We always support uncompressed archives. */
+	archive_read_support_compression_none((struct archive*)a);
+
+	return (a);
+}
+
+/*
+ * Set the block size.
+ */
+/*
+int
+archive_read_set_bytes_per_block(struct archive *a, int bytes_per_block)
+{
+	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
+	if (bytes_per_block < 1)
+		bytes_per_block = 1;
+	a->bytes_per_block = bytes_per_block;
+	return (0);
+}
+*/
+
+/*
+ * Open the archive
+ */
+int
+archive_read_open(struct archive *a, void *client_data,
+    archive_open_callback *opener, archive_read_callback *reader,
+    archive_close_callback *closer)
+{
+	const void *buffer;
+	size_t bytes_read;
+	int high_bidder;
+	int e;
+
+	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
+
+	if (reader == NULL)
+		errx(1,
+		    "Fatal: No reader function provided to archive_read_open");
+
+	a->client_reader = reader;
+	a->client_opener = opener;
+	a->client_closer = closer;
+	a->client_data = client_data;
+
+	a->state = ARCHIVE_STATE_HEADER;
+
+	/* Open data source. */
+	if (a->client_opener != NULL) {
+		e =(a->client_opener)(a, a->client_data);
+		if (e != 0)
+			return (e);
+	}
+
+	/* Read first block now for format detection. */
+	bytes_read = (a->client_reader)(a, a->client_data, &buffer);
+
+	/* Select a decompression routine. */
+	high_bidder = choose_decompressor(a, buffer, bytes_read);
+	if (high_bidder < 0)
+		return (ARCHIVE_FATAL);
+
+	/* Initialize decompression routine with the first block of data. */
+	e = (a->decompressors[high_bidder].init)(a, buffer, bytes_read);
+	return (e);
+}
+
+/*
+ * Allow each registered decompression routine to bid on whether it
+ * wants to handle this stream.  Return index of winning bidder.
+ */
+static int
+choose_decompressor(struct archive *a, const void *buffer, size_t bytes_read)
+{
+	int decompression_slots, i, bid, best_bid, best_bid_slot;
+
+	decompression_slots = sizeof(a->decompressors) /
+	    sizeof(a->decompressors[0]);
+
+	best_bid = -1;
+	best_bid_slot = -1;
+
+	for (i = 0; i < decompression_slots; i++) {
+		if (a->decompressors[i].bid) {
+			bid = (a->decompressors[i].bid)(buffer, bytes_read);
+			if ((bid > best_bid) || (best_bid_slot < 0)) {
+				best_bid = bid;
+				best_bid_slot = i;
+			}
+		}
+	}
+
+	/*
+	 * There were no bidders; this is a serious programmer error
+	 * and demands a quick and definitive abort.
+	 */
+	if (best_bid_slot < 0)
+		errx(1, "Fatal: No decompressors were registered; you "
+		    "must call at least one "
+		    "archive_read_support_compression_XXX function in order "
+		    "to successfully read an archive.");
+
+	/*
+	 * There were bidders, but no non-zero bids; this means we  can't
+	 * support this stream.
+	 */
+	if (best_bid < 1) {
+		archive_set_error(a, EFTYPE, "Unrecognized archive format");
+		/* EFTYPE == "Inappropriate file type or format" */
+		return (ARCHIVE_FATAL);
+	}
+
+	return (best_bid_slot);
+}
+
+/*
+ * Read header of next entry.
+ */
+int
+archive_read_next_header(struct archive *a, struct archive_entry **entryp)
+{
+	struct archive_entry *entry;
+	int slot, ret;
+
+	archive_check_magic(a, ARCHIVE_READ_MAGIC,
+	    ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA);
+
+	*entryp = NULL;
+	entry = a->entry;
+	archive_entry_clear(entry);
+
+	/*
+	 * If client didn't consume entire data, skip any remainder
+	 * (This is especially important for GNU incremental directories.)
+	 */
+	if (a->state == ARCHIVE_STATE_DATA) {
+		ret = archive_read_data_skip(a);
+		if (ret == ARCHIVE_EOF) {
+			archive_set_error(a, EIO, "Premature end-of-file.");
+			a->state = ARCHIVE_STATE_FATAL;
+			return (ARCHIVE_FATAL);
+		}
+	}
+
+	/* Record start-of-header. */
+	a->header_position = a->file_position;
+
+	slot = choose_format(a);
+	if (slot < 0) {
+		a->state = ARCHIVE_STATE_FATAL;
+		return (ARCHIVE_FATAL);
+	}
+	a->format = &(a->formats[slot]);
+	a->pformat_data = &(a->format->format_data);
+	ret = (a->format->read_header)(a, entry);
+
+	/*
+	 * EOF and FATAL are persistent at this layer.  By
+	 * modifying the state, we gaurantee that future calls to
+	 * read a header or read data will fail.
+	 */
+	switch (ret) {
+	case ARCHIVE_EOF:
+		a->state = ARCHIVE_STATE_EOF;
+		break;
+	case ARCHIVE_OK:
+		a->state = ARCHIVE_STATE_DATA;
+		break;
+	case ARCHIVE_WARN:
+		a->state = ARCHIVE_STATE_DATA;
+		break;
+	case ARCHIVE_RETRY:
+		break;
+	case ARCHIVE_FATAL:
+		a->state = ARCHIVE_STATE_FATAL;
+		break;
+	}
+
+	*entryp = entry;
+	return (ret);
+}
+
+/*
+ * Allow each registered format to bid on whether it wants to handle
+ * the next entry.  Return index of winning bidder.
+ */
+static int
+choose_format(struct archive *a)
+{
+	int slots;
+	int i;
+	int bid, best_bid;
+	int best_bid_slot;
+
+	slots = sizeof(a->formats) / sizeof(a->formats[0]);
+	best_bid = -1;
+	best_bid_slot = -1;
+
+	/* Set up a->format and a->pformat_data for convenience of bidders. */
+	a->format = &(a->formats[0]);
+	for (i = 0; i < slots; i++, a->format++) {
+		if (a->format->bid) {
+			a->pformat_data = &(a->format->format_data);
+			bid = (a->format->bid)(a);
+			if (bid == ARCHIVE_FATAL)
+				return (ARCHIVE_FATAL);
+			if ((bid > best_bid) || (best_bid_slot < 0)) {
+				best_bid = bid;
+				best_bid_slot = i;
+			}
+		}
+	}
+
+	/*
+	 * There were no bidders; this is a serious programmer error
+	 * and demands a quick and definitive abort.
+	 */
+	if (best_bid_slot < 0)
+		errx(1, "Fatal: No formats were registered; you must "
+		    "invoke at least one archive_read_support_format_XXX "
+		    "function in order to successfully read an archive.");
+
+	/*
+	 * There were bidders, but no non-zero bids; this means we
+	 * can't support this stream.
+	 */
+	if (best_bid < 1) {
+		archive_set_error(a, EFTYPE, "Unrecognized archive format");
+		return (ARCHIVE_FATAL);
+	}
+
+	return (best_bid_slot);
+}
+
+/*
+ * Return the file offset (within the uncompressed data stream) where
+ * the last header started.
+ */
+int64_t
+archive_read_header_position(struct archive *a)
+{
+	return (a->header_position);
+}
+
+/*
+ * Read data from an archive entry.
+ */
+ssize_t
+archive_read_data(struct archive *a, void *buff, size_t s)
+{
+	const void *data;
+	ssize_t bytes_read;
+
+	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA);
+	if (s > a->entry_bytes_remaining)
+		s = a->entry_bytes_remaining;
+	if (s > 0) {
+		bytes_read = (a->compression_read_ahead)(a, &data, 1);
+		if (bytes_read < 0) {
+			a->state = ARCHIVE_STATE_FATAL;
+			return (bytes_read);
+		}
+		if ((size_t)bytes_read > s)
+			bytes_read = s;
+	} else
+		bytes_read = 0;
+
+	if (bytes_read > 0) {
+		memcpy(buff, data, bytes_read);
+		(a->compression_read_consume)(a, bytes_read);
+	}
+
+	a->entry_bytes_remaining -= bytes_read;
+	return (bytes_read);
+}
+
+/*
+ * Skip over all remaining data in this entry.
+ */
+int
+archive_read_data_skip(struct archive *a)
+{
+	const void *buff;
+	ssize_t bytes_read, to_skip;
+
+	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA);
+
+	to_skip = a->entry_bytes_remaining + a->entry_padding;
+	a->entry_bytes_remaining = 0;
+
+	for (; to_skip > 0; to_skip -= bytes_read) {
+		/* TODO: Optimize skip in compression layer. */
+		bytes_read = (a->compression_read_ahead)(a, &buff, to_skip);
+		if (bytes_read < 0) {
+			a->entry_padding = to_skip;
+			return (ARCHIVE_FATAL);
+		}
+		if (bytes_read == 0) {
+			archive_set_error(a, 0,
+			    "Premature end of archive entry");
+			return (ARCHIVE_FATAL);
+		}
+		if (bytes_read > to_skip)
+			bytes_read = to_skip;
+		(a->compression_read_consume)(a, bytes_read);
+	}
+	a->entry_padding = 0;
+	a->state = ARCHIVE_STATE_HEADER;
+	return (ARCHIVE_OK);
+}
+
+/*
+ * Cleanup and free the archive object.
+ *
+ * Be careful: client might just call read_new and then read_finish.
+ * Don't assume we actually read anything or performed any non-trivial
+ * initialization.
+ */
+void
+archive_read_finish(struct archive *a)
+{
+	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_ANY);
+	a->state = ARCHIVE_STATE_CLOSED;
+
+	/* Call cleanup functions registered by optional components. */
+	if (a->cleanup_archive_extract != NULL)
+		(a->cleanup_archive_extract)(a);
+
+	/* TODO: Finish the format processing. */
+
+	/* Close the input machinery. */
+	if (a->compression_finish != NULL)
+		(a->compression_finish)(a);
+
+	/*-
+	 * Release allocated strings.
+	 *
+	 * TODO: Add a "cleanup" column to the "formats" array and
+	 * use that to cleanup format-specific data.  E.g.,
+	 *
+	 * for (i=0; i< slots; i++) {
+	 *   if (a->formats[i].cleanup)
+	 *     (a->formats[i].cleanup)(a);
+	 * }
+	 */
+	/* Casting a pointer to int allows us to remove 'const.' */
+	free((void *)(uintptr_t)(const void *)a->nulls);
+	if (a->entry_name.s != NULL)
+		free(a->entry_name.s);
+	if (a->entry_linkname.s != NULL)
+		free(a->entry_linkname.s);
+	if (a->entry_uname.s != NULL)
+		free(a->entry_uname.s);
+	if (a->entry_gname.s != NULL)
+		free(a->entry_gname.s);
+	if (a->pax_header.s != NULL)
+		free(a->pax_header.s);
+	if (a->gnu_name.s != NULL)
+		free(a->gnu_name.s);
+	if (a->gnu_linkname.s != NULL)
+		free(a->gnu_linkname.s);
+	if (a->extract_mkdirpath.s != NULL)
+		free(a->extract_mkdirpath.s);
+	if (a->entry)
+		archive_entry_free(a->entry);
+	free(a);
+}
+
+/*
+ * Used internally by read format handlers to register their bid and
+ * initialization functions.
+ */
+int
+__archive_read_register_format(struct archive *a,
+    void *format_data,
+    int (*bid)(struct archive *),
+    int (*read_header)(struct archive *, struct archive_entry *),
+    int (*cleanup)(struct archive *))
+{
+	int i, number_slots;
+
+	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
+
+	number_slots = sizeof(a->formats) / sizeof(a->formats[0]);
+
+	for (i = 0; i < number_slots; i++) {
+		if (a->formats[i].bid == bid)
+			return (0); /* We've already installed */
+		if (a->formats[i].bid == NULL) {
+			a->formats[i].bid = bid;
+			a->formats[i].read_header = read_header;
+			a->formats[i].cleanup = cleanup;
+			a->formats[i].format_data = format_data;
+			return (ARCHIVE_OK);
+		}
+	}
+
+	errx(1, "Fatal: Not enough slots for format registration");
+}
+
+/*
+ * Used internally by decompression routines to register their bid and
+ * initialization functions.
+ */
+int
+__archive_read_register_compression(struct archive *a,
+    int (*bid)(const void *, size_t),
+    int (*init)(struct archive *, const void *, size_t))
+{
+	int i, number_slots;
+
+	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
+
+	number_slots = sizeof(a->decompressors) / sizeof(a->decompressors[0]);
+
+	for (i = 0; i < number_slots; i++) {
+		if (a->decompressors[i].bid == bid)
+			return (ARCHIVE_OK); /* We've already installed */
+		if (a->decompressors[i].bid == NULL) {
+			a->decompressors[i].bid = bid;
+			a->decompressors[i].init = init;
+			return (ARCHIVE_OK);
+		}
+	}
+
+	errx(1, "Fatal: Not enough slots for compression registration");
+}