From 2f172ede7115d0a2730a3b689131042ba559e272 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Wed, 19 Jun 2019 15:04:17 +0200 Subject: Split generic tar code off to static library Signed-off-by: David Oberhollenzer --- tar/Makemodule.am | 8 +- tar/read_header.c | 415 ----------------------------------------------------- tar/skip.c | 48 ------- tar/tar.h | 65 --------- tar/write_header.c | 248 -------------------------------- 5 files changed, 4 insertions(+), 780 deletions(-) delete mode 100644 tar/read_header.c delete mode 100644 tar/skip.c delete mode 100644 tar/tar.h delete mode 100644 tar/write_header.c (limited to 'tar') diff --git a/tar/Makemodule.am b/tar/Makemodule.am index 6c9edc7..a10dc01 100644 --- a/tar/Makemodule.am +++ b/tar/Makemodule.am @@ -1,9 +1,9 @@ -sqfs2tar_SOURCES = tar/sqfs2tar.c tar/tar.h tar/write_header.c -sqfs2tar_LDADD = libsquashfs.a libfstree.a libcompress.a libutil.a +sqfs2tar_SOURCES = tar/sqfs2tar.c +sqfs2tar_LDADD = libsquashfs.a libtar.a libfstree.a libcompress.a libutil.a sqfs2tar_LDADD += $(XZ_LIBS) $(ZLIB_LIBS) $(LZO_LIBS) $(LZ4_LIBS) $(ZSTD_LIBS) -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_SOURCES = tar/tar2sqfs.c +tar2sqfs_LDADD = libsquashfs.a libtar.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 deleted file mode 100644 index bdb2d20..0000000 --- a/tar/read_header.c +++ /dev/null @@ -1,415 +0,0 @@ -/* SPDX-License-Identifier: GPL-3.0-or-later */ -#include "util.h" -#include "tar.h" - -#include -#include -#include -#include -#include - -enum { - PAX_SIZE = 0x001, - PAX_UID = 0x002, - PAX_GID = 0x004, - PAX_DEV_MAJ = 0x008, - PAX_DEV_MIN = 0x010, - PAX_NAME = 0x020, - PAX_SLINK_TARGET = 0x040, - PAX_ATIME = 0x080, - PAX_MTIME = 0x100, - PAX_CTIME = 0x200, -}; - -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(©, hdr, sizeof(*hdr)); - memset(copy.chksum, ' ', sizeof(copy.chksum)); - - for (i = 0; i < sizeof(copy); ++i) - chksum += ((unsigned char *)©)[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; - uint64_t field; - 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, &field); - out->sb.st_uid = field; - *set_by_pax |= PAX_UID; - } else if (!strncmp(line, "gid=", 4)) { - pax_read_decimal(line + 4, &field); - out->sb.st_gid = field; - *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, &field); - out->sb.st_size = field; - *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; - } else if (!strncmp(line, "atime=", 6)) { - pax_read_decimal(line + 6, &field); - out->sb.st_atime = field; - *set_by_pax |= PAX_ATIME; - } else if (!strncmp(line, "mtime=", 6)) { - pax_read_decimal(line + 6, &field); - out->sb.st_mtime = field; - *set_by_pax |= PAX_MTIME; - } else if (!strncmp(line, "ctime=", 6)) { - pax_read_decimal(line + 6, &field); - out->sb.st_ctime = field; - *set_by_pax |= PAX_CTIME; - } - } - - 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) -{ - uint64_t field; - 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), &field)) - return -1; - out->sb.st_size = field; - } - - if (!(set_by_pax & PAX_UID)) { - if (read_number(hdr->uid, sizeof(hdr->uid), &field)) - return -1; - out->sb.st_uid = field; - } - - if (!(set_by_pax & PAX_GID)) { - if (read_number(hdr->gid, sizeof(hdr->gid), &field)) - return -1; - out->sb.st_gid = field; - } - - if (!(set_by_pax & PAX_DEV_MAJ)) { - if (read_number(hdr->devmajor, sizeof(hdr->devmajor), &field)) - return -1; - - out->sb.st_rdev = makedev(field, minor(out->sb.st_rdev)); - } - - if (!(set_by_pax & PAX_DEV_MIN)) { - if (read_number(hdr->devminor, sizeof(hdr->devminor), &field)) - return -1; - - out->sb.st_rdev = makedev(major(out->sb.st_rdev), field); - } - - if (!(set_by_pax & PAX_MTIME)) { - if (read_number(hdr->mtime, sizeof(hdr->mtime), &field)) - return -1; - out->sb.st_mtime = field; - } - - if (!(set_by_pax & PAX_ATIME)) - out->sb.st_atime = out->sb.st_mtime; - - if (!(set_by_pax & PAX_CTIME)) - out->sb.st_ctime = out->sb.st_mtime; - - if (read_octal(hdr->mode, sizeof(hdr->mode), &field)) - return -1; - - out->sb.st_mode = field & 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->sb.st_mode |= S_IFREG; - break; - case TAR_TYPE_LINK: - /* XXX: hard links are not support yet */ - out->sb.st_mode = S_IFLNK | 0777; - break; - case TAR_TYPE_SLINK: - out->sb.st_mode = S_IFLNK | 0777; - break; - case TAR_TYPE_CHARDEV: - out->sb.st_mode |= S_IFCHR; - break; - case TAR_TYPE_BLOCKDEV: - out->sb.st_mode |= S_IFBLK; - break; - case TAR_TYPE_DIR: - out->sb.st_mode |= S_IFDIR; - break; - case TAR_TYPE_FIFO: - out->sb.st_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 deleted file mode 100644 index 69208b2..0000000 --- a/tar/skip.c +++ /dev/null @@ -1,48 +0,0 @@ -/* SPDX-License-Identifier: GPL-3.0-or-later */ -#include "util.h" -#include "tar.h" - -#include - -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 deleted file mode 100644 index 7862235..0000000 --- a/tar/tar.h +++ /dev/null @@ -1,65 +0,0 @@ -/* SPDX-License-Identifier: GPL-3.0-or-later */ -#ifndef TAR_H -#define TAR_H - -#include -#include - -typedef struct { - char name[100]; - char mode[8]; - char uid[8]; - char gid[8]; - char size[12]; - char mtime[12]; - char chksum[8]; - char typeflag; - char linkname[100]; - char magic[6]; - char version[2]; - char uname[32]; - char gname[32]; - char devmajor[8]; - char devminor[8]; - char prefix[155]; - char padding[12]; -} tar_header_t; - -typedef struct { - struct stat sb; - 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' -#define TAR_TYPE_CHARDEV '3' -#define TAR_TYPE_BLOCKDEV '4' -#define TAR_TYPE_DIR '5' -#define TAR_TYPE_FIFO '6' - -#define TAR_TYPE_PAX 'x' - -#define TAR_MAGIC "ustar" -#define TAR_VERSION "00" - -/* - Returns < 0 on failure, > 0 if cannot encode, 0 on success. - Prints error/warning messages to stderr. -*/ -int write_tar_header(int fd, const struct stat *sb, const char *name, - const char *slink_target); - -/* 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/write_header.c b/tar/write_header.c deleted file mode 100644 index 80db327..0000000 --- a/tar/write_header.c +++ /dev/null @@ -1,248 +0,0 @@ -/* SPDX-License-Identifier: GPL-3.0-or-later */ -#include "util.h" -#include "tar.h" - -#include -#include -#include - -static unsigned long pax_hdr_counter = 0; -static char buffer[4096]; - -static void write_octal(char *dst, unsigned int value, int digits) -{ - char temp[64]; - - sprintf(temp, "%0*o ", digits, value); - memcpy(dst, temp, strlen(temp)); -} - -static int name_to_tar_header(tar_header_t *hdr, const char *path) -{ - size_t len = strlen(path); - const char *ptr; - - if ((len + 1) <= sizeof(hdr->name)) { - memcpy(hdr->name, path, len); - return 0; - } - - for (ptr = path; ; ++ptr) { - ptr = strchr(ptr, '/'); - if (ptr == NULL) - return -1; - - len = ptr - path; - if (len >= sizeof(hdr->prefix)) - continue; - if (strlen(ptr + 1) >= sizeof(hdr->name)) - continue; - break; - } - - memcpy(hdr->prefix, path, ptr - path); - memcpy(hdr->name, ptr + 1, strlen(ptr + 1)); - return 0; -} - -static void init_header(tar_header_t *hdr, const struct stat *sb, - const char *name, const char *slink_target) -{ - memset(hdr, 0, sizeof(*hdr)); - - name_to_tar_header(hdr, name); - memcpy(hdr->magic, TAR_MAGIC, sizeof(hdr->magic)); - memcpy(hdr->version, TAR_VERSION, sizeof(hdr->version)); - write_octal(hdr->mode, sb->st_mode & ~S_IFMT, 6); - write_octal(hdr->uid, sb->st_uid, 6); - write_octal(hdr->gid, sb->st_gid, 6); - write_octal(hdr->mtime, sb->st_mtime, 11); - write_octal(hdr->size, 0, 11); - write_octal(hdr->devmajor, 0, 6); - write_octal(hdr->devminor, 0, 6); - - switch (sb->st_mode & S_IFMT) { - case S_IFREG: - write_octal(hdr->size, sb->st_size & 077777777777L, 11); - break; - case S_IFLNK: - if (sb->st_size < (off_t)sizeof(hdr->linkname)) - strcpy(hdr->linkname, slink_target); - break; - case S_IFCHR: - case S_IFBLK: - write_octal(hdr->devmajor, major(sb->st_rdev), 6); - write_octal(hdr->devminor, minor(sb->st_rdev), 6); - break; - } - - sprintf(hdr->uname, "%u", sb->st_uid); - sprintf(hdr->gname, "%u", sb->st_gid); -} - -static void update_checksum(tar_header_t *hdr) -{ - unsigned int chksum = 0; - size_t i; - - memset(hdr->chksum, ' ', sizeof(hdr->chksum)); - - for (i = 0; i < sizeof(*hdr); ++i) - chksum += ((unsigned char *)hdr)[i]; - - write_octal(hdr->chksum, chksum, 6); - hdr->chksum[6] = '\0'; - hdr->chksum[7] = ' '; -} - -static bool need_pax_header(const struct stat *sb, const char *name) -{ - tar_header_t tmp; - - if (sb->st_uid > 0777777 || sb->st_gid > 0777777) - return true; - - if (S_ISREG(sb->st_mode) && sb->st_size > 077777777777L) - return true; - - if (S_ISLNK(sb->st_mode) && sb->st_size >= (off_t)sizeof(tmp.linkname)) - return true; - - if (name_to_tar_header(&tmp, name)) - return true; - - return false; -} - -static char *write_pax_entry(char *dst, const char *key, const char *value) -{ - size_t i, len, prefix = 0, oldprefix; - - do { - len = prefix + 1 + strlen(key) + 1 + strlen(value) + 1; - - oldprefix = prefix; - prefix = 1; - - for (i = len; i >= 10; i /= 10) - ++prefix; - } while (oldprefix != prefix); - - sprintf(dst, "%zu %s=%s\n", len, key, value); - - return dst + len; -} - -static int write_pax_header(int fd, const struct stat *sb, const char *name, - const char *slink_target) -{ - char temp[64], *ptr; - struct stat fakesb; - tar_header_t hdr; - ssize_t ret; - size_t len; - - memset(buffer, 0, sizeof(buffer)); - memset(&fakesb, 0, sizeof(fakesb)); - fakesb.st_mode = S_IFREG | 0644; - - sprintf(temp, "pax%lu", pax_hdr_counter); - init_header(&hdr, &fakesb, temp, NULL); - hdr.typeflag = TAR_TYPE_PAX; - - sprintf(temp, "%u", sb->st_uid); - ptr = buffer; - ptr = write_pax_entry(ptr, "uid", temp); - ptr = write_pax_entry(ptr, "uname", temp); - - sprintf(temp, "%lu", sb->st_mtime); - ptr = write_pax_entry(ptr, "mtime", temp); - - sprintf(temp, "%u", sb->st_gid); - ptr = write_pax_entry(ptr, "gid", temp); - ptr = write_pax_entry(ptr, "gname", temp); - - ptr = write_pax_entry(ptr, "path", name); - - if (S_ISLNK(sb->st_mode)) { - ptr = write_pax_entry(ptr, "linkpath", slink_target); - } else if (S_ISREG(sb->st_mode)) { - sprintf(temp, "%lu", sb->st_size); - ptr = write_pax_entry(ptr, "size", temp); - } - - len = strlen(buffer); - write_octal(hdr.size, len, 11); - update_checksum(&hdr); - - ret = write_retry(fd, &hdr, sizeof(hdr)); - if (ret < 0) - goto fail_wr; - if ((size_t)ret < sizeof(hdr)) - goto fail_trunc; - - ret = write_retry(fd, buffer, len); - if (ret < 0) - goto fail_wr; - if ((size_t)ret < len) - goto fail_trunc; - - return padd_file(fd, len, 512); -fail_wr: - perror("writing pax header"); - return -1; -fail_trunc: - fputs("writing pax header: truncated write\n", stderr); - return -1; -} - -int write_tar_header(int fd, const struct stat *sb, const char *name, - const char *slink_target) -{ - const char *reason; - tar_header_t hdr; - ssize_t ret; - - if (need_pax_header(sb, name)) { - if (write_pax_header(fd, sb, name, slink_target)) - return -1; - - sprintf(buffer, "pax%lu_data", pax_hdr_counter++); - name = buffer; - } - - init_header(&hdr, sb, name, slink_target); - - switch (sb->st_mode & S_IFMT) { - case S_IFCHR: hdr.typeflag = TAR_TYPE_CHARDEV; break; - case S_IFBLK: hdr.typeflag = TAR_TYPE_BLOCKDEV; break; - case S_IFLNK: hdr.typeflag = TAR_TYPE_SLINK; break; - case S_IFREG: hdr.typeflag = TAR_TYPE_FILE; break; - case S_IFDIR: hdr.typeflag = TAR_TYPE_DIR; break; - case S_IFIFO: hdr.typeflag = TAR_TYPE_FIFO; break; - case S_IFSOCK: - reason = "cannot pack socket"; - goto out_skip; - default: - reason = "unknown type"; - goto out_skip; - } - - update_checksum(&hdr); - - ret = write_retry(fd, &hdr, sizeof(hdr)); - - if (ret < 0) { - perror("writing header record"); - } else if ((size_t)ret < sizeof(hdr)) { - fputs("writing header record: truncated write\n", stderr); - ret = -1; - } else { - ret = 0; - } - - return ret; -out_skip: - fprintf(stderr, "WARNING: skipping '%s' (%s)\n", name, reason); - return 1; -} -- cgit v1.2.3