From 949d1c2a5553b54fe6bc2b8c7aca10a892e595d7 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Sun, 5 May 2019 01:03:16 +0200 Subject: rdsquashfs: reorder unpack flags, add flag to produce listing The listing command has been used successfully to do the following: - generate a prestine file system using gensquashfs - repeate multiple times: - generate a listing from the file system - unpack only the regular files from the file system - generate a new file system from the listing - run `diff` on the old and new filesystem and admire that they are identical - replace the old file system with the new one, since they are identical Signed-off-by: David Oberhollenzer --- unpack/Makemodule.am | 2 +- unpack/describe.c | 73 +++++++++++++++++++++++++++++++++++++++++++++ unpack/rdsquashfs.c | 79 ++++++++++++++++++++++++++++--------------------- unpack/rdsquashfs.h | 2 ++ unpack/restore_fstree.c | 31 +++++++++++-------- 5 files changed, 139 insertions(+), 48 deletions(-) create mode 100644 unpack/describe.c (limited to 'unpack') diff --git a/unpack/Makemodule.am b/unpack/Makemodule.am index 6a0eab0..d47cb5e 100644 --- a/unpack/Makemodule.am +++ b/unpack/Makemodule.am @@ -1,7 +1,7 @@ rdsquashfs_SOURCES = unpack/rdsquashfs.c unpack/tree_node_from_inode.c rdsquashfs_SOURCES += unpack/rdsquashfs.h unpack/read_fstree.c rdsquashfs_SOURCES += unpack/list_files.c unpack/extract_file.c -rdsquashfs_SOURCES += unpack/restore_fstree.c +rdsquashfs_SOURCES += unpack/restore_fstree.c unpack/describe.c rdsquashfs_LDADD = libsquashfs.a libfstree.a libcompress.a libutil.a if WITH_XZ diff --git a/unpack/describe.c b/unpack/describe.c new file mode 100644 index 0000000..94e7d22 --- /dev/null +++ b/unpack/describe.c @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "rdsquashfs.h" + +#include + +static void print_name(tree_node_t *n) +{ + if (n->parent != NULL) { + print_name(n->parent); + fputc('/', stdout); + } + + fputs(n->name, stdout); +} + +static void print_perm(tree_node_t *n) +{ + printf(" 0%o %d %d", n->mode & (~S_IFMT), n->uid, n->gid); +} + +static void print_simple(const char *type, tree_node_t *n, const char *extra) +{ + printf("%s ", type); + print_name(n); + print_perm(n); + if (extra != NULL) + printf(" %s", extra); + fputc('\n', stdout); +} + +void describe_tree(tree_node_t *root, const char *unpack_root) +{ + tree_node_t *n; + + switch (root->mode & S_IFMT) { + case S_IFSOCK: + print_simple("sock", root, NULL); + break; + case S_IFLNK: + print_simple("slink", root, root->data.slink_target); + break; + case S_IFIFO: + print_simple("pipe", root, NULL); + break; + case S_IFREG: + if (unpack_root != NULL) { + fputs("file ", stdout); + print_name(root); + print_perm(root); + printf(" %s", unpack_root); + print_name(root); + fputc('\n', stdout); + } else { + print_simple("file", root, NULL); + } + break; + case S_IFCHR: + case S_IFBLK: { + char buffer[32]; + sprintf(buffer, "%c %d %d", S_ISCHR(root->mode) ? 'c' : 'b', + major(root->data.devno), minor(root->data.devno)); + print_simple("nod", root, buffer); + break; + } + case S_IFDIR: + if (root->name[0] != '\0') + print_simple("dir", root, NULL); + + for (n = root->data.dir->children; n != NULL; n = n->next) + describe_tree(n, unpack_root); + break; + } +} diff --git a/unpack/rdsquashfs.c b/unpack/rdsquashfs.c index f09847d..a24434c 100644 --- a/unpack/rdsquashfs.c +++ b/unpack/rdsquashfs.c @@ -6,18 +6,20 @@ enum { OP_LS, OP_CAT, OP_UNPACK, + OP_DESCRIBE, }; static struct option long_opts[] = { { "list", required_argument, NULL, 'l' }, { "cat", required_argument, NULL, 'c' }, - { "unpack-root", required_argument, NULL, 'u' }, - { "unpack-path", required_argument, NULL, 'p' }, + { "unpack-root", required_argument, NULL, 'p' }, + { "unpack-path", required_argument, NULL, 'u' }, { "no-dev", no_argument, NULL, 'D' }, { "no-sock", no_argument, NULL, 'S' }, { "no-fifo", no_argument, NULL, 'F' }, { "no-slink", no_argument, NULL, 'L' }, { "no-empty-dir", no_argument, NULL, 'E' }, + { "describe", no_argument, NULL, 'd' }, { "chmod", no_argument, NULL, 'C' }, { "chown", no_argument, NULL, 'O' }, { "quiet", no_argument, NULL, 'q' }, @@ -25,7 +27,7 @@ static struct option long_opts[] = { { "version", no_argument, NULL, 'V' }, }; -static const char *short_opts = "l:c:u:p:DSFLCOEqhV"; +static const char *short_opts = "l:c:u:p:DSFLCOEdqhV"; static const char *help_string = "Usage: %s [OPTIONS] \n" @@ -33,27 +35,34 @@ static const char *help_string = "View or extract the contents of a squashfs image.\n" "\n" "Possible options:\n" -" --list, -l Produce a directory listing for a given path in the\n" -" squashfs image.\n" -" --cat, -c If the specified path is a regular file in the,\n" -" image, dump its contents to stdout.\n" -" --unpack-root Unpack the contents of the filesystem into the\n" -" specified path.\n" -" --unpack-path If specified, unpack this sub directory from the\n" -" image instead of the filesystem root.\n" -" --no-dev, -D Do not unpack device special files.\n" -" --no-sock, -S Do not unpack socket files.\n" -" --no-fifo, -F Do not unpack named pipes.\n" -" --no-slink, -L Do not unpack symbolic links.\n" -" --no-empty-dir, -E Do not unpack directories that would end up empty.\n" -" --chmod, -C Change permission flags of unpacked files to those\n" -" store in the squashfs image.\n" -" --chown, -O Change ownership of unpacked files to the UID/GID\n" -" set in the squashfs image.\n" -" --quiet, -q Do not print out progress while unpacking.\n" "\n" -" --help, -h Print help text and exit.\n" -" --version, -V Print version information and exit.\n" +" --list, -l Produce a directory listing for a given path in\n" +" the squashfs image.\n" +" --cat, -c If the specified path is a regular file in the,\n" +" image, dump its contents to stdout.\n" +" --unpack-path, -u Unpack this sub directory from the image. To\n" +" unpack everything, simply specify /.\n" +" --describe, -d Produce a file listing from the image.\n" +"\n" +" --unpack-root, -p If used with --unpack-path, this is where the\n" +" data unpacked to. If used with --describe, this\n" +" is used as a prefix for the input path of\n" +" regular files.\n" +"\n" +" --no-dev, -D Do not unpack device special files.\n" +" --no-sock, -S Do not unpack socket files.\n" +" --no-fifo, -F Do not unpack named pipes.\n" +" --no-slink, -L Do not unpack symbolic links.\n" +" --no-empty-dir, -E Do not unpack directories that would end up\n" +" empty after applying the above rules.\n" +" --chmod, -C Change permission flags of unpacked files to\n" +" those store in the squashfs image.\n" +" --chown, -O Change ownership of unpacked files to the\n" +" UID/GID set in the squashfs image.\n" +" --quiet, -q Do not print out progress while unpacking.\n" +"\n" +" --help, -h Print help text and exit.\n" +" --version, -V Print version information and exit.\n" "\n"; extern const char *__progname; @@ -192,15 +201,18 @@ int main(int argc, char **argv) op = OP_CAT; cmdpath = get_path(cmdpath, optarg); break; + case 'd': + op = OP_DESCRIBE; + break; case 'l': op = OP_LS; cmdpath = get_path(cmdpath, optarg); break; - case 'u': - op = OP_UNPACK; + case 'p': unpack_root = optarg; break; - case 'p': + case 'u': + op = OP_UNPACK; cmdpath = get_path(cmdpath, optarg); break; case 'q': @@ -303,14 +315,10 @@ int main(int argc, char **argv) goto out_fs; break; case OP_UNPACK: - if (cmdpath == NULL) { - n = fs.root; - } else { - n = find_node(fs.root, cmdpath); - if (n == NULL) { - perror(cmdpath); - goto out_fs; - } + n = find_node(fs.root, cmdpath); + if (n == NULL) { + perror(cmdpath); + goto out_fs; } if (load_fragment_table(&info, &super)) @@ -322,6 +330,9 @@ int main(int argc, char **argv) if (restore_fstree(unpack_root, n, &info)) goto out_fs; break; + case OP_DESCRIBE: + describe_tree(fs.root, unpack_root); + break; } status = EXIT_SUCCESS; diff --git a/unpack/rdsquashfs.h b/unpack/rdsquashfs.h index a9d5bdf..f1cd131 100644 --- a/unpack/rdsquashfs.h +++ b/unpack/rdsquashfs.h @@ -55,4 +55,6 @@ int extract_file(file_info_t *fi, unsqfs_info_t *info, int outfd); int restore_fstree(const char *rootdir, tree_node_t *root, unsqfs_info_t *info); +void describe_tree(tree_node_t *root, const char *unpack_root); + #endif /* RDSQUASHFS_H */ diff --git a/unpack/restore_fstree.c b/unpack/restore_fstree.c index c1320ea..3e7f500 100644 --- a/unpack/restore_fstree.c +++ b/unpack/restore_fstree.c @@ -117,27 +117,32 @@ int restore_fstree(const char *rootdir, tree_node_t *root, unsqfs_info_t *info) if (mkdir_p(rootdir)) return -1; - dirfd = open(rootdir, O_RDONLY | O_DIRECTORY); - if (dirfd < 0) { - perror(rootdir); - return -1; + if (rootdir == NULL) { + dirfd = AT_FDCWD; + } else { + dirfd = open(rootdir, O_RDONLY | O_DIRECTORY); + if (dirfd < 0) { + perror(rootdir); + return -1; + } } if (S_ISDIR(root->mode)) { for (n = root->data.dir->children; n != NULL; n = n->next) { - if (create_node(dirfd, n, info)) { - close(dirfd); - return -1; - } + if (create_node(dirfd, n, info)) + goto fail; } return 0; } - if (create_node(dirfd, root, info)) { - close(dirfd); - return -1; - } + if (create_node(dirfd, root, info)) + goto fail; - close(dirfd); + if (dirfd != AT_FDCWD) + close(dirfd); return 0; +fail: + if (dirfd != AT_FDCWD) + close(dirfd); + return -1; } -- cgit v1.2.3