aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-06-13 17:16:06 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-06-15 17:43:42 +0200
commite1a47443ad2ee424b2be9c2d4f2761dfe85ded1a (patch)
tree1c8aec5af456820f2fa236355ffa2d5ffc31f04e
parent46b30ac7559ca26f5446b05d852eaaefe432a290 (diff)
Add utility to turn a POSIX/PAX tar archive into a squashfs image
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
-rw-r--r--.gitignore1
-rw-r--r--tar/Makemodule.am6
-rw-r--r--tar/read_header.c379
-rw-r--r--tar/skip.c48
-rw-r--r--tar/tar.h22
-rw-r--r--tar/tar2sqfs.c267
6 files changed, 722 insertions, 1 deletions
diff --git a/.gitignore b/.gitignore
index 532b328..a0fc326 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,4 @@ config.h
gensquashfs
rdsquashfs
sqfs2tar
+tar2sqfs
diff --git a/tar/Makemodule.am b/tar/Makemodule.am
index d192380..6c9edc7 100644
--- a/tar/Makemodule.am
+++ b/tar/Makemodule.am
@@ -2,4 +2,8 @@ sqfs2tar_SOURCES = tar/sqfs2tar.c tar/tar.h tar/write_header.c
sqfs2tar_LDADD = libsquashfs.a libfstree.a libcompress.a libutil.a
sqfs2tar_LDADD += $(XZ_LIBS) $(ZLIB_LIBS) $(LZO_LIBS) $(LZ4_LIBS) $(ZSTD_LIBS)
-bin_PROGRAMS += sqfs2tar
+tar2sqfs_SOURCES = tar/tar2sqfs.c tar/skip.c tar/read_header.c tar/tar.h
+tar2sqfs_LDADD = libsquashfs.a libfstree.a libcompress.a libutil.a
+tar2sqfs_LDADD += $(XZ_LIBS) $(ZLIB_LIBS) $(LZO_LIBS) $(LZ4_LIBS) $(ZSTD_LIBS)
+
+bin_PROGRAMS += sqfs2tar tar2sqfs
diff --git a/tar/read_header.c b/tar/read_header.c
new file mode 100644
index 0000000..099a9ce
--- /dev/null
+++ b/tar/read_header.c
@@ -0,0 +1,379 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "util.h"
+#include "tar.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdio.h>
+
+enum {
+ PAX_SIZE = 0x01,
+ PAX_UID = 0x02,
+ PAX_GID = 0x04,
+ PAX_DEV_MAJ = 0x08,
+ PAX_DEV_MIN = 0x10,
+ PAX_NAME = 0x20,
+ PAX_SLINK_TARGET = 0x40,
+};
+
+static int read_octal(const char *str, int digits, uint64_t *out)
+{
+ uint64_t result = 0;
+
+ while (digits > 0 && *str >= '0' && *str <= '7') {
+ if (result > 0x1FFFFFFFFFFFFFFFUL) {
+ fputs("numeric overflow parsing tar header\n", stderr);
+ return -1;
+ }
+
+ result = (result << 3) | (*(str++) - '0');
+ --digits;
+ }
+
+ *out = result;
+ return 0;
+}
+
+static int read_binary(const char *str, int digits, uint64_t *out)
+{
+ uint64_t x, result = 0;
+
+ while (digits > 0) {
+ if (result > 0x00FFFFFFFFFFFFFFUL) {
+ fputs("numeric overflow parsing tar header\n", stderr);
+ return -1;
+ }
+
+ x = *((const unsigned char *)str++);
+ result = (result << 8) | x;
+ --digits;
+ }
+
+ *out = result;
+ return 0;
+}
+
+static int read_number(const char *str, int digits, uint64_t *out)
+{
+ if (*((unsigned char *)str) & 0x80) {
+ if (read_binary(str, digits, out))
+ return -1;
+ *out &= 0x7FFFFFFFFFFFFFFF;
+ return 0;
+ }
+
+ return read_octal(str, digits, out);
+}
+
+static bool is_zero_block(const tar_header_t *hdr)
+{
+ const unsigned char *ptr = (const unsigned char *)hdr;
+
+ return ptr[0] == '\0' && memcmp(ptr, ptr + 1, sizeof(*hdr) - 1) == 0;
+}
+
+static bool is_checksum_valid(const tar_header_t *hdr)
+{
+ unsigned int chksum = 0;
+ tar_header_t copy;
+ uint64_t ref;
+ size_t i;
+
+ if (read_octal(hdr->chksum, sizeof(hdr->chksum), &ref))
+ return false;
+
+ memcpy(&copy, hdr, sizeof(*hdr));
+ memset(copy.chksum, ' ', sizeof(copy.chksum));
+
+ for (i = 0; i < sizeof(copy); ++i)
+ chksum += ((unsigned char *)&copy)[i];
+
+ return chksum == ref;
+}
+
+static bool is_magic_valid(const tar_header_t *hdr)
+{
+ if (memcmp(hdr->magic, TAR_MAGIC, sizeof(hdr->magic)) != 0)
+ return false;
+
+ if (memcmp(hdr->version, TAR_VERSION, sizeof(hdr->version)) != 0)
+ return false;
+
+ return true;
+}
+
+static int pax_read_decimal(const char *str, uint64_t *out)
+{
+ uint64_t result = 0;
+
+ while (*str >= '0' && *str <= '9') {
+ if (result > 0xFFFFFFFFFFFFFFFFUL / 10) {
+ fputs("numeric overflow parsing pax header\n", stderr);
+ return -1;
+ }
+
+ result = (result * 10) + (*(str++) - '0');
+ }
+
+ *out = result;
+ return 0;
+}
+
+static int read_pax_header(int fd, uint64_t entsize, unsigned int *set_by_pax,
+ tar_header_decoded_t *out)
+{
+ char *buffer, *line;
+ ssize_t ret;
+ uint64_t i;
+
+ buffer = malloc(entsize + 1);
+ if (buffer == NULL)
+ goto fail_errno;
+
+ ret = read_retry(fd, buffer, entsize);
+ if (ret < 0)
+ goto fail_errno;
+ if ((size_t)ret < entsize)
+ goto fail_eof;
+
+ if (skip_padding(fd, entsize))
+ goto fail;
+
+ buffer[entsize] = '\0';
+
+ for (i = 0; i < entsize; ++i) {
+ while (i < entsize && isspace(buffer[i]))
+ ++i;
+ while (i < entsize && isdigit(buffer[i]))
+ ++i;
+ while (i < entsize && isspace(buffer[i]))
+ ++i;
+ if (i >= entsize)
+ break;
+
+ line = buffer + i;
+
+ while (i < entsize && buffer[i] != '\n')
+ ++i;
+
+ buffer[i] = '\0';
+
+ if (!strncmp(line, "uid=", 4)) {
+ pax_read_decimal(line + 4, &out->uid);
+ *set_by_pax |= PAX_UID;
+ } else if (!strncmp(line, "gid=", 4)) {
+ pax_read_decimal(line + 4, &out->gid);
+ *set_by_pax |= PAX_GID;
+ } else if (!strncmp(line, "path=", 5)) {
+ free(out->name);
+ out->name = strdup(line + 5);
+ if (out->name == NULL)
+ goto fail_errno;
+ *set_by_pax |= PAX_NAME;
+ } else if (!strncmp(line, "size=", 5)) {
+ pax_read_decimal(line + 5, &out->size);
+ *set_by_pax |= PAX_SIZE;
+ } else if (!strncmp(line, "linkpath=", 9)) {
+ free(out->link_target);
+ out->link_target = strdup(line + 9);
+ if (out->link_target == NULL)
+ goto fail_errno;
+ *set_by_pax |= PAX_SLINK_TARGET;
+ }
+ }
+
+ free(buffer);
+ return 0;
+fail_errno:
+ perror("reading pax header");
+ goto fail;
+fail_eof:
+ fputs("reading pax header: unexpected end of file\n", stderr);
+ goto fail;
+fail:
+ free(buffer);
+ return -1;
+}
+
+static int decode_header(const tar_header_t *hdr, unsigned int set_by_pax,
+ tar_header_decoded_t *out)
+{
+ size_t count;
+
+ if (!(set_by_pax & PAX_NAME)) {
+ if (hdr->prefix[0] == '\0') {
+ count = strlen(hdr->name) + 1;
+ count += strlen(hdr->prefix) + 1;
+
+ out->name = malloc(count);
+
+ if (out->name != NULL) {
+ sprintf(out->name, "%s/%s",
+ hdr->prefix, hdr->name);
+ }
+ } else {
+ out->name = strdup(hdr->name);
+ }
+
+ if (out->name == NULL) {
+ perror("decoding filename");
+ return -1;
+ }
+ }
+
+ if (!(set_by_pax & PAX_SIZE)) {
+ if (read_number(hdr->size, sizeof(hdr->size), &out->size))
+ return -1;
+ }
+
+ if (!(set_by_pax & PAX_UID)) {
+ if (read_number(hdr->uid, sizeof(hdr->uid), &out->uid))
+ return -1;
+ }
+
+ if (!(set_by_pax & PAX_GID)) {
+ if (read_number(hdr->gid, sizeof(hdr->gid), &out->gid))
+ return -1;
+ }
+
+ if (!(set_by_pax & PAX_DEV_MAJ)) {
+ if (read_number(hdr->devmajor, sizeof(hdr->devmajor),
+ &out->dev_maj)) {
+ return -1;
+ }
+ }
+
+ if (!(set_by_pax & PAX_DEV_MIN)) {
+ if (read_number(hdr->devminor, sizeof(hdr->devminor),
+ &out->dev_min)) {
+ return -1;
+ }
+ }
+
+ if (read_octal(hdr->mode, sizeof(hdr->mode), &out->mode))
+ return -1;
+
+ out->mode &= 07777;
+
+ if (hdr->typeflag == TAR_TYPE_LINK ||
+ hdr->typeflag == TAR_TYPE_SLINK) {
+ if (!(set_by_pax & PAX_SLINK_TARGET)) {
+ out->link_target = strdup(hdr->linkname);
+ if (out->link_target == NULL) {
+ perror("decoding symlink target");
+ return -1;
+ }
+ }
+ }
+
+ out->unknown_record = false;
+
+ switch (hdr->typeflag) {
+ case '\0':
+ case TAR_TYPE_FILE:
+ out->mode |= S_IFREG;
+ break;
+ case TAR_TYPE_LINK:
+ /* XXX: hard links are not support yet */
+ out->mode = S_IFLNK | 0777;
+ break;
+ case TAR_TYPE_SLINK:
+ out->mode = S_IFLNK | 0777;
+ break;
+ case TAR_TYPE_CHARDEV:
+ out->mode |= S_IFCHR;
+ break;
+ case TAR_TYPE_BLOCKDEV:
+ out->mode |= S_IFBLK;
+ break;
+ case TAR_TYPE_DIR:
+ out->mode |= S_IFDIR;
+ break;
+ case TAR_TYPE_FIFO:
+ out->mode |= S_IFIFO;
+ break;
+ default:
+ out->unknown_record = true;
+ break;
+ }
+
+ return 0;
+}
+
+int read_header(int fd, tar_header_decoded_t *out)
+{
+ unsigned int set_by_pax = 0;
+ bool prev_was_zero = false;
+ uint64_t pax_size;
+ tar_header_t hdr;
+ int ret;
+
+ memset(out, 0, sizeof(*out));
+
+ for (;;) {
+ ret = read_retry(fd, &hdr, sizeof(hdr));
+ if (ret == 0)
+ goto out_eof;
+ if (ret < 0)
+ goto fail_errno;
+ if (ret < (int)sizeof(hdr))
+ goto fail_eof;
+
+ if (is_zero_block(&hdr)) {
+ if (prev_was_zero)
+ goto out_eof;
+ prev_was_zero = true;
+ continue;
+ }
+
+ prev_was_zero = false;
+
+ if (!is_magic_valid(&hdr))
+ goto fail_magic;
+
+ if (!is_checksum_valid(&hdr))
+ goto fail_chksum;
+
+ if (hdr.typeflag == TAR_TYPE_PAX) {
+ clear_header(out);
+ if (read_number(hdr.size, sizeof(hdr.size), &pax_size))
+ return -1;
+ set_by_pax = 0;
+ if (read_pax_header(fd, pax_size, &set_by_pax, out))
+ return -1;
+ continue;
+ }
+ break;
+ }
+
+ if (decode_header(&hdr, set_by_pax, out))
+ goto fail;
+
+ return 0;
+out_eof:
+ clear_header(out);
+ return 1;
+fail_errno:
+ perror("reading tar header");
+ goto fail;
+fail_eof:
+ fputs("reading tar header: unexpected end of file\n", stderr);
+ goto fail;
+fail_magic:
+ fputs("input is not a ustar tar archive!\n", stderr);
+ goto fail;
+fail_chksum:
+ fputs("invalid tar header checksum!\n", stderr);
+ goto fail;
+fail:
+ clear_header(out);
+ return -1;
+}
+
+void clear_header(tar_header_decoded_t *hdr)
+{
+ free(hdr->name);
+ free(hdr->link_target);
+ memset(hdr, 0, sizeof(*hdr));
+}
diff --git a/tar/skip.c b/tar/skip.c
new file mode 100644
index 0000000..69208b2
--- /dev/null
+++ b/tar/skip.c
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "util.h"
+#include "tar.h"
+
+#include <stdio.h>
+
+static int skip_bytes(int fd, uint64_t size)
+{
+ unsigned char buffer[1024];
+ ssize_t ret;
+ size_t diff;
+
+ while (size != 0) {
+ diff = sizeof(buffer);
+ if (diff > size)
+ diff = size;
+
+ ret = read_retry(fd, buffer, diff);
+
+ if (ret < 0) {
+ perror("reading tar record data");
+ return -1;
+ }
+
+ if ((size_t)ret < diff) {
+ fputs("unexpected end of file\n", stderr);
+ return -1;
+ }
+
+ size -= diff;
+ }
+
+ return 0;
+}
+
+int skip_padding(int fd, uint64_t size)
+{
+ size_t tail = size % 512;
+
+ return tail ? skip_bytes(fd, 512 - tail) : 0;
+}
+
+int skip_entry(int fd, uint64_t size)
+{
+ size_t tail = size % 512;
+
+ return skip_bytes(fd, tail ? (size + 512 - tail) : size);
+}
diff --git a/tar/tar.h b/tar/tar.h
index 62c612a..11af6ee 100644
--- a/tar/tar.h
+++ b/tar/tar.h
@@ -24,6 +24,18 @@ typedef struct {
char padding[12];
} tar_header_t;
+typedef struct {
+ uint64_t size;
+ uint64_t mode;
+ uint64_t uid;
+ uint64_t gid;
+ uint64_t dev_maj;
+ uint64_t dev_min;
+ char *name;
+ char *link_target;
+ bool unknown_record;
+} tar_header_decoded_t;
+
#define TAR_TYPE_FILE '0'
#define TAR_TYPE_LINK '1'
#define TAR_TYPE_SLINK '2'
@@ -44,4 +56,14 @@ typedef struct {
int write_tar_header(int fd, const fstree_t *fs, const tree_node_t *n,
const char *name);
+/* calcuate and skip the zero padding */
+int skip_padding(int fd, uint64_t size);
+
+/* round up to block size and skip the entire entry */
+int skip_entry(int fd, uint64_t size);
+
+int read_header(int fd, tar_header_decoded_t *out);
+
+void clear_header(tar_header_decoded_t *hdr);
+
#endif /* TAR_H */
diff --git a/tar/tar2sqfs.c b/tar/tar2sqfs.c
new file mode 100644
index 0000000..f00f281
--- /dev/null
+++ b/tar/tar2sqfs.c
@@ -0,0 +1,267 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "data_writer.h"
+#include "highlevel.h"
+#include "squashfs.h"
+#include "compress.h"
+#include "id_table.h"
+#include "fstree.h"
+#include "util.h"
+#include "tar.h"
+
+#include <sys/sysmacros.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+
+static struct option long_opts[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, 'V' },
+};
+
+static const char *short_opts = "hV";
+
+static const char *usagestr =
+"Usage: tar2sqfs [OPTIONS...] <sqfsfile>\n"
+"\n"
+"Read an uncompressed tar archive from stdin and turn it into a squashfs\n"
+"filesystem image.\n"
+"\n"
+"Possible options:\n"
+"\n"
+" --help, -h Print help text and exit.\n"
+" --version, -V Print version information and exit.\n"
+"\n"
+"Examples:\n"
+"\n"
+"\ttar2sqfs rootfs.sqfs < rootfs.tar\n"
+"\tzcat rootfs.tar.gz | tar2sqfs rootfs.sqfs\n"
+"\txzcat rootfs.tar.xz | tar2sqfs rootfs.sqfs\n"
+"\n";
+
+static const char *filename;
+static int block_size = SQFS_DEFAULT_BLOCK_SIZE;
+static uint32_t def_mtime = 0;
+static uint16_t def_mode = 0755;
+static uint32_t def_uid = 0;
+static uint32_t def_gid = 0;
+static size_t devblksize = SQFS_DEVBLK_SIZE;
+
+static void process_args(int argc, char **argv)
+{
+ int i;
+
+ for (;;) {
+ i = getopt_long(argc, argv, short_opts, long_opts, NULL);
+ if (i == -1)
+ break;
+
+ switch (i) {
+ case 'h':
+ fputs(usagestr, stdout);
+ exit(EXIT_SUCCESS);
+ case 'V':
+ print_version();
+ exit(EXIT_SUCCESS);
+ default:
+ goto fail_arg;
+ }
+ }
+
+ if (optind >= argc) {
+ fputs("Missing argument: squashfs image\n", stderr);
+ goto fail_arg;
+ }
+
+ filename = argv[optind++];
+
+ if (optind < argc) {
+ fputs("Unknown extra arguments\n", stderr);
+ goto fail_arg;
+ }
+ return;
+fail_arg:
+ fputs("Try `tar2sqfs --help' for more information.\n", stderr);
+ exit(EXIT_FAILURE);
+}
+
+static int create_node_and_repack_data(tar_header_decoded_t *hdr, fstree_t *fs,
+ data_writer_t *data)
+{
+ tree_node_t *node;
+ size_t extra = 0;
+
+ if (S_ISLNK(hdr->mode))
+ extra = strlen(hdr->link_target) + 1;
+
+ if (S_ISREG(hdr->mode)) {
+ node = fstree_add_file(fs, hdr->name, hdr->mode,
+ hdr->uid, hdr->gid, hdr->size, NULL);
+ if (node == NULL)
+ goto fail_errno;
+
+ if (write_data_from_fd(data, node->data.file,
+ STDIN_FILENO)) {
+ return -1;
+ }
+
+ if (skip_padding(STDIN_FILENO, node->data.file->size))
+ return -1;
+ } else {
+ node = fstree_add(fs, hdr->name, hdr->mode,
+ hdr->uid, hdr->gid, extra);
+ if (node == NULL)
+ goto fail_errno;
+
+ if (S_ISLNK(hdr->mode)) {
+ strcpy(node->data.slink_target,
+ hdr->link_target);
+ } else if (S_ISBLK(hdr->mode) || S_ISCHR(hdr->mode)) {
+ node->data.devno = makedev(hdr->dev_maj, hdr->dev_min);
+ }
+ }
+
+ return 0;
+fail_errno:
+ perror(hdr->name);
+ return -1;
+}
+
+static int process_tar_ball(fstree_t *fs, data_writer_t *data)
+{
+ tar_header_decoded_t hdr;
+ int ret;
+
+ for (;;) {
+ ret = read_header(STDIN_FILENO, &hdr);
+ if (ret > 0)
+ break;
+ if (ret < 0)
+ return -1;
+
+ if (hdr.unknown_record) {
+ fprintf(stderr, "skipping '%s' (unknown entry type)\n",
+ hdr.name);
+ if (skip_entry(STDIN_FILENO, hdr.size))
+ goto fail;
+ continue;
+ }
+
+ if (canonicalize_name(hdr.name)) {
+ fprintf(stderr, "skipping '%s' (invalid name)\n",
+ hdr.name);
+ if (skip_entry(STDIN_FILENO, hdr.size))
+ goto fail;
+ continue;
+ }
+
+ if (create_node_and_repack_data(&hdr, fs, data))
+ goto fail;
+
+ clear_header(&hdr);
+ }
+
+ return 0;
+fail:
+ clear_header(&hdr);
+ return -1;
+}
+
+int main(int argc, char **argv)
+{
+ int outfd, status = EXIT_SUCCESS;
+ E_SQFS_COMPRESSOR comp_id;
+ data_writer_t *data;
+ sqfs_super_t super;
+ compressor_t *cmp;
+ id_table_t idtbl;
+ fstree_t fs;
+ int ret;
+
+ process_args(argc, argv);
+
+ outfd = open(filename, O_CREAT | O_EXCL | O_RDWR, 0644);
+ if (outfd < 0) {
+ perror(filename);
+ return EXIT_FAILURE;
+ }
+
+ if (fstree_init(&fs, block_size, def_mtime, def_mode,
+ def_uid, def_gid)) {
+ goto out_fd;
+ }
+
+ comp_id = compressor_get_default();
+
+ cmp = compressor_create(comp_id, true, block_size, NULL);
+ if (cmp == NULL) {
+ fputs("Error creating compressor\n", stderr);
+ goto out_fs;
+ }
+
+ if (sqfs_super_init(&super, block_size, def_mtime, comp_id))
+ goto out_cmp;
+
+ if (sqfs_super_write(&super, outfd))
+ goto out_cmp;
+
+ ret = cmp->write_options(cmp, outfd);
+ if (ret < 0)
+ goto out_cmp;
+
+ if (ret > 0) {
+ super.flags |= SQFS_FLAG_COMPRESSOR_OPTIONS;
+ super.bytes_used += ret;
+ }
+
+ data = data_writer_create(&super, cmp, outfd);
+ if (data == NULL)
+ goto out_cmp;
+
+ if (id_table_init(&idtbl))
+ goto out_data;
+
+ if (process_tar_ball(&fs, data))
+ goto out;
+
+ if (data_writer_flush_fragments(data))
+ goto out;
+
+ fstree_sort(&fs);
+ if (fstree_gen_inode_table(&fs))
+ goto out;
+
+ super.inode_count = fs.inode_tbl_size - 2;
+
+ if (sqfs_serialize_fstree(outfd, &super, &fs, cmp, &idtbl))
+ goto out;
+
+ if (data_writer_write_fragment_table(data))
+ goto out;
+
+ if (id_table_write(&idtbl, outfd, &super, cmp))
+ goto out;
+
+ if (sqfs_super_write(&super, outfd))
+ goto out;
+
+ if (padd_file(outfd, super.bytes_used, devblksize))
+ goto out;
+
+ status = EXIT_SUCCESS;
+out:
+ id_table_cleanup(&idtbl);
+out_data:
+ data_writer_destroy(data);
+out_cmp:
+ cmp->destroy(cmp);
+out_fs:
+ fstree_cleanup(&fs);
+out_fd:
+ close(outfd);
+ return status;
+}