diff options
Diffstat (limited to 'archival/libunarchive/get_header_tar.c')
| -rw-r--r-- | archival/libunarchive/get_header_tar.c | 461 |
1 files changed, 0 insertions, 461 deletions
diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c deleted file mode 100644 index cf6487207..000000000 --- a/archival/libunarchive/get_header_tar.c +++ /dev/null @@ -1,461 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* Licensed under GPLv2 or later, see file LICENSE in this source tree. - * - * FIXME: - * In privileged mode if uname and gname map to a uid and gid then use the - * mapped value instead of the uid/gid values in tar header - * - * References: - * GNU tar and star man pages, - * Opengroup's ustar interchange format, - * http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html - */ - -#include "libbb.h" -#include "unarchive.h" - -typedef uint32_t aliased_uint32_t FIX_ALIASING; -typedef off_t aliased_off_t FIX_ALIASING; - - -/* NB: _DESTROYS_ str[len] character! */ -static unsigned long long getOctal(char *str, int len) -{ - unsigned long long v; - char *end; - /* NB: leading spaces are allowed. Using strtoull to handle that. - * The downside is that we accept e.g. "-123" too :( - */ - str[len] = '\0'; - v = strtoull(str, &end, 8); - /* std: "Each numeric field is terminated by one or more - * <space> or NUL characters". We must support ' '! */ - if (*end != '\0' && *end != ' ') { - int8_t first = str[0]; - if (!(first & 0x80)) - bb_error_msg_and_die("corrupted octal value in tar header"); - /* - * GNU tar uses "base-256 encoding" for very large numbers. - * Encoding is binary, with highest bit always set as a marker - * and sign in next-highest bit: - * 80 00 .. 00 - zero - * bf ff .. ff - largest positive number - * ff ff .. ff - minus 1 - * c0 00 .. 00 - smallest negative number - * - * Example of tar file with 8914993153 (0x213600001) byte file. - * Field starts at offset 7c: - * 00070 30 30 30 00 30 30 30 30 30 30 30 00 80 00 00 00 |000.0000000.....| - * 00080 00 00 00 02 13 60 00 01 31 31 31 32 30 33 33 36 |.....`..11120336| - * - * NB: tarballs with NEGATIVE unix times encoded that way were seen! - */ - v = first; - /* Sign-extend using 6th bit: */ - v <<= sizeof(unsigned long long)*8 - 7; - v = (long long)v >> (sizeof(unsigned long long)*8 - 7); - while (--len != 0) - v = (v << 8) + (unsigned char) *str++; - } - return v; -} -#define GET_OCTAL(a) getOctal((a), sizeof(a)) - -#if ENABLE_FEATURE_TAR_SELINUX -/* Scan a PAX header for SELinux contexts, via "RHT.security.selinux" keyword. - * This is what Red Hat's patched version of tar uses. - */ -# define SELINUX_CONTEXT_KEYWORD "RHT.security.selinux" -static char *get_selinux_sctx_from_pax_hdr(archive_handle_t *archive_handle, unsigned sz) -{ - char *buf, *p; - char *result; - - p = buf = xmalloc(sz + 1); - /* prevent bb_strtou from running off the buffer */ - buf[sz] = '\0'; - xread(archive_handle->src_fd, buf, sz); - archive_handle->offset += sz; - - result = NULL; - while (sz != 0) { - char *end, *value; - unsigned len; - - /* Every record has this format: "LEN NAME=VALUE\n" */ - len = bb_strtou(p, &end, 10); - /* expect errno to be EINVAL, because the character - * following the digits should be a space - */ - p += len; - sz -= len; - if ((int)sz < 0 - || len == 0 - || errno != EINVAL - || *end != ' ' - ) { - bb_error_msg("malformed extended header, skipped"); - // More verbose version: - //bb_error_msg("malformed extended header at %"OFF_FMT"d, skipped", - // archive_handle->offset - (sz + len)); - break; - } - /* overwrite the terminating newline with NUL - * (we do not bother to check that it *was* a newline) - */ - p[-1] = '\0'; - /* Is it selinux security context? */ - value = end + 1; - if (strncmp(value, SELINUX_CONTEXT_KEYWORD"=", sizeof(SELINUX_CONTEXT_KEYWORD"=") - 1) == 0) { - value += sizeof(SELINUX_CONTEXT_KEYWORD"=") - 1; - result = xstrdup(value); - break; - } - } - - free(buf); - return result; -} -#endif - -char FAST_FUNC get_header_tar(archive_handle_t *archive_handle) -{ - file_header_t *file_header = archive_handle->file_header; - struct tar_header_t tar; - char *cp; - int i, sum_u, sum; -#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY - int sum_s; -#endif - int parse_names; - - /* Our "private data" */ -#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS -# define p_longname (archive_handle->tar__longname) -# define p_linkname (archive_handle->tar__linkname) -#else -# define p_longname 0 -# define p_linkname 0 -#endif - -#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS || ENABLE_FEATURE_TAR_SELINUX - again: -#endif - /* Align header */ - data_align(archive_handle, 512); - - again_after_align: - -#if ENABLE_DESKTOP || ENABLE_FEATURE_TAR_AUTODETECT - /* to prevent misdetection of bz2 sig */ - *(aliased_uint32_t*)&tar = 0; - i = full_read(archive_handle->src_fd, &tar, 512); - /* If GNU tar sees EOF in above read, it says: - * "tar: A lone zero block at N", where N = kilobyte - * where EOF was met (not EOF block, actual EOF!), - * and exits with EXIT_SUCCESS. - * We will mimic exit(EXIT_SUCCESS), although we will not mimic - * the message and we don't check whether we indeed - * saw zero block directly before this. */ - if (i == 0) { - xfunc_error_retval = 0; - short_read: - bb_error_msg_and_die("short read"); - } - if (i != 512) { - IF_FEATURE_TAR_AUTODETECT(goto autodetect;) - goto short_read; - } - -#else - i = 512; - xread(archive_handle->src_fd, &tar, i); -#endif - archive_handle->offset += i; - - /* If there is no filename its an empty header */ - if (tar.name[0] == 0 && tar.prefix[0] == 0) { - if (archive_handle->tar__end) { - /* Second consecutive empty header - end of archive. - * Read until the end to empty the pipe from gz or bz2 - */ - while (full_read(archive_handle->src_fd, &tar, 512) == 512) - continue; - return EXIT_FAILURE; - } - archive_handle->tar__end = 1; - return EXIT_SUCCESS; - } - archive_handle->tar__end = 0; - - /* Check header has valid magic, "ustar" is for the proper tar, - * five NULs are for the old tar format */ - if (strncmp(tar.magic, "ustar", 5) != 0 - && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY - || memcmp(tar.magic, "\0\0\0\0", 5) != 0) - ) { -#if ENABLE_FEATURE_TAR_AUTODETECT - char FAST_FUNC (*get_header_ptr)(archive_handle_t *); - uint16_t magic2; - - autodetect: - magic2 = *(uint16_t*)tar.name; - /* tar gz/bz autodetect: check for gz/bz2 magic. - * If we see the magic, and it is the very first block, - * we can switch to get_header_tar_gz/bz2/lzma(). - * Needs seekable fd. I wish recv(MSG_PEEK) works - * on any fd... */ -# if ENABLE_FEATURE_SEAMLESS_GZ - if (magic2 == GZIP_MAGIC) { - get_header_ptr = get_header_tar_gz; - } else -# endif -# if ENABLE_FEATURE_SEAMLESS_BZ2 - if (magic2 == BZIP2_MAGIC - && tar.name[2] == 'h' && isdigit(tar.name[3]) - ) { /* bzip2 */ - get_header_ptr = get_header_tar_bz2; - } else -# endif -# if ENABLE_FEATURE_SEAMLESS_XZ - //TODO: if (magic2 == XZ_MAGIC1)... - //else -# endif - goto err; - /* Two different causes for lseek() != 0: - * unseekable fd (would like to support that too, but...), - * or not first block (false positive, it's not .gz/.bz2!) */ - if (lseek(archive_handle->src_fd, -i, SEEK_CUR) != 0) - goto err; - while (get_header_ptr(archive_handle) == EXIT_SUCCESS) - continue; - return EXIT_FAILURE; - err: -#endif /* FEATURE_TAR_AUTODETECT */ - bb_error_msg_and_die("invalid tar magic"); - } - - /* Do checksum on headers. - * POSIX says that checksum is done on unsigned bytes, but - * Sun and HP-UX gets it wrong... more details in - * GNU tar source. */ -#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY - sum_s = ' ' * sizeof(tar.chksum); -#endif - sum_u = ' ' * sizeof(tar.chksum); - for (i = 0; i < 148; i++) { - sum_u += ((unsigned char*)&tar)[i]; -#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY - sum_s += ((signed char*)&tar)[i]; -#endif - } - for (i = 156; i < 512; i++) { - sum_u += ((unsigned char*)&tar)[i]; -#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY - sum_s += ((signed char*)&tar)[i]; -#endif - } - /* This field does not need special treatment (getOctal) */ - { - char *endp; /* gcc likes temp var for &endp */ - sum = strtoul(tar.chksum, &endp, 8); - if ((*endp != '\0' && *endp != ' ') - || (sum_u != sum IF_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum)) - ) { - bb_error_msg_and_die("invalid tar header checksum"); - } - } - /* don't use xstrtoul, tar.chksum may have leading spaces */ - sum = strtoul(tar.chksum, NULL, 8); - if (sum_u != sum IF_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum)) { - bb_error_msg_and_die("invalid tar header checksum"); - } - - /* 0 is reserved for high perf file, treat as normal file */ - if (!tar.typeflag) tar.typeflag = '0'; - parse_names = (tar.typeflag >= '0' && tar.typeflag <= '7'); - - /* getOctal trashes subsequent field, therefore we call it - * on fields in reverse order */ - if (tar.devmajor[0]) { - char t = tar.prefix[0]; - /* we trash prefix[0] here, but we DO need it later! */ - unsigned minor = GET_OCTAL(tar.devminor); - unsigned major = GET_OCTAL(tar.devmajor); - file_header->device = makedev(major, minor); - tar.prefix[0] = t; - } - file_header->link_target = NULL; - if (!p_linkname && parse_names && tar.linkname[0]) { - file_header->link_target = xstrndup(tar.linkname, sizeof(tar.linkname)); - /* FIXME: what if we have non-link object with link_target? */ - /* Will link_target be free()ed? */ - } -#if ENABLE_FEATURE_TAR_UNAME_GNAME - file_header->tar__uname = tar.uname[0] ? xstrndup(tar.uname, sizeof(tar.uname)) : NULL; - file_header->tar__gname = tar.gname[0] ? xstrndup(tar.gname, sizeof(tar.gname)) : NULL; -#endif - file_header->mtime = GET_OCTAL(tar.mtime); - file_header->size = GET_OCTAL(tar.size); - file_header->gid = GET_OCTAL(tar.gid); - file_header->uid = GET_OCTAL(tar.uid); - /* Set bits 0-11 of the files mode */ - file_header->mode = 07777 & GET_OCTAL(tar.mode); - - file_header->name = NULL; - if (!p_longname && parse_names) { - /* we trash mode[0] here, it's ok */ - //tar.name[sizeof(tar.name)] = '\0'; - gcc 4.3.0 would complain - tar.mode[0] = '\0'; - if (tar.prefix[0]) { - /* and padding[0] */ - //tar.prefix[sizeof(tar.prefix)] = '\0'; - gcc 4.3.0 would complain - tar.padding[0] = '\0'; - file_header->name = concat_path_file(tar.prefix, tar.name); - } else - file_header->name = xstrdup(tar.name); - } - - /* Set bits 12-15 of the files mode */ - /* (typeflag was not trashed because chksum does not use getOctal) */ - switch (tar.typeflag) { - /* busybox identifies hard links as being regular files with 0 size and a link name */ - case '1': - file_header->mode |= S_IFREG; - break; - case '7': - /* case 0: */ - case '0': -#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY - if (last_char_is(file_header->name, '/')) { - goto set_dir; - } -#endif - file_header->mode |= S_IFREG; - break; - case '2': - file_header->mode |= S_IFLNK; - /* have seen tarballs with size field containing - * the size of the link target's name */ - size0: - file_header->size = 0; - break; - case '3': - file_header->mode |= S_IFCHR; - goto size0; /* paranoia */ - case '4': - file_header->mode |= S_IFBLK; - goto size0; - case '5': - IF_FEATURE_TAR_OLDGNU_COMPATIBILITY(set_dir:) - file_header->mode |= S_IFDIR; - goto size0; - case '6': - file_header->mode |= S_IFIFO; - goto size0; -#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS - case 'L': - /* free: paranoia: tar with several consecutive longnames */ - free(p_longname); - /* For paranoia reasons we allocate extra NUL char */ - p_longname = xzalloc(file_header->size + 1); - /* We read ASCIZ string, including NUL */ - xread(archive_handle->src_fd, p_longname, file_header->size); - archive_handle->offset += file_header->size; - /* return get_header_tar(archive_handle); */ - /* gcc 4.1.1 didn't optimize it into jump */ - /* so we will do it ourself, this also saves stack */ - goto again; - case 'K': - free(p_linkname); - p_linkname = xzalloc(file_header->size + 1); - xread(archive_handle->src_fd, p_linkname, file_header->size); - archive_handle->offset += file_header->size; - /* return get_header_tar(archive_handle); */ - goto again; - case 'D': /* GNU dump dir */ - case 'M': /* Continuation of multi volume archive */ - case 'N': /* Old GNU for names > 100 characters */ - case 'S': /* Sparse file */ - case 'V': /* Volume header */ -#endif -#if !ENABLE_FEATURE_TAR_SELINUX - case 'g': /* pax global header */ - case 'x': /* pax extended header */ -#else - skip_ext_hdr: -#endif - { - off_t sz; - bb_error_msg("warning: skipping header '%c'", tar.typeflag); - sz = (file_header->size + 511) & ~(off_t)511; - archive_handle->offset += sz; - sz >>= 9; /* sz /= 512 but w/o contortions for signed div */ - while (sz--) - xread(archive_handle->src_fd, &tar, 512); - /* return get_header_tar(archive_handle); */ - goto again_after_align; - } -#if ENABLE_FEATURE_TAR_SELINUX - case 'g': /* pax global header */ - case 'x': { /* pax extended header */ - char **pp; - if ((uoff_t)file_header->size > 0xfffff) /* paranoia */ - goto skip_ext_hdr; - pp = (tar.typeflag == 'g') ? &archive_handle->tar__global_sctx : &archive_handle->tar__next_file_sctx; - free(*pp); - *pp = get_selinux_sctx_from_pax_hdr(archive_handle, file_header->size); - goto again; - } -#endif - default: - bb_error_msg_and_die("unknown typeflag: 0x%x", tar.typeflag); - } - -#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS - if (p_longname) { - file_header->name = p_longname; - p_longname = NULL; - } - if (p_linkname) { - file_header->link_target = p_linkname; - p_linkname = NULL; - } -#endif - if (strncmp(file_header->name, "/../"+1, 3) == 0 - || strstr(file_header->name, "/../") - ) { - bb_error_msg_and_die("name with '..' encountered: '%s'", - file_header->name); - } - - /* Strip trailing '/' in directories */ - /* Must be done after mode is set as '/' is used to check if it's a directory */ - cp = last_char_is(file_header->name, '/'); - - if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) { - archive_handle->action_header(/*archive_handle->*/ file_header); - /* Note that we kill the '/' only after action_header() */ - /* (like GNU tar 1.15.1: verbose mode outputs "dir/dir/") */ - if (cp) - *cp = '\0'; - archive_handle->action_data(archive_handle); - if (archive_handle->accept || archive_handle->reject) - llist_add_to(&archive_handle->passed, file_header->name); - else /* Caller isn't interested in list of unpacked files */ - free(file_header->name); - } else { - data_skip(archive_handle); - free(file_header->name); - } - archive_handle->offset += file_header->size; - - free(file_header->link_target); - /* Do not free(file_header->name)! - * It might be inserted in archive_handle->passed - see above */ -#if ENABLE_FEATURE_TAR_UNAME_GNAME - free(file_header->tar__uname); - free(file_header->tar__gname); -#endif - return EXIT_SUCCESS; -} |