X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Freparse.c;h=4df2a4b428831fd02cee77329a5ba198ba0a2514;hb=028300650d936240c6d3a4da4fb30da62dd44692;hp=2bc421d2a57b424f3e8bea4d82295523132d0355;hpb=cd31971d325d4757dbd72064939ab9d43acd5e96;p=wimlib diff --git a/src/reparse.c b/src/reparse.c index 2bc421d2..4df2a4b4 100644 --- a/src/reparse.c +++ b/src/reparse.c @@ -28,124 +28,19 @@ #include "wimlib/assert.h" #include "wimlib/compiler.h" #include "wimlib/endianness.h" -#include "wimlib/dentry.h" #include "wimlib/encoding.h" #include "wimlib/error.h" +#include "wimlib/inode.h" #include "wimlib/lookup_table.h" #include "wimlib/reparse.h" #include "wimlib/resource.h" -#ifdef __WIN32__ -# include "wimlib/win32.h" /* for win32_get_file_and_vol_ids() */ -#endif - #ifdef HAVE_ALLOCA_H # include #endif #include #include -/* On-disk format of a symbolic link (WIM_IO_REPARSE_TAG_SYMLINK) or junction - * point (WIM_IO_REPARSE_TAG_MOUNT_POINT) reparse data buffer. */ -struct reparse_buffer_disk { - le32 rptag; - le16 rpdatalen; - le16 rpreserved; - le16 substitute_name_offset; - le16 substitute_name_nbytes; - le16 print_name_offset; - le16 print_name_nbytes; - union { - struct { - le32 rpflags; - u8 data[REPARSE_POINT_MAX_SIZE - 20]; - } _packed_attribute symlink; - struct { - u8 data[REPARSE_POINT_MAX_SIZE - 16]; - } _packed_attribute junction; - }; -} _packed_attribute; - -static const utf16lechar volume_junction_prefix[11] = { - cpu_to_le16('\\'), - cpu_to_le16('?'), - cpu_to_le16('?'), - cpu_to_le16('\\'), - cpu_to_le16('V'), - cpu_to_le16('o'), - cpu_to_le16('l'), - cpu_to_le16('u'), - cpu_to_le16('m'), - cpu_to_le16('e'), - cpu_to_le16('{'), -}; - -/* Parse the "substitute name" (link target) from a symbolic link or junction - * reparse point. - * - * Return value is: - * - * Non-negative integer: - * The name is an absolute symbolic link in one of several formats, - * and the return value is the number of UTF-16LE characters that need to - * be advanced to reach a simple "absolute" path starting with a backslash - * (i.e. skip over \??\ and/or drive letter) - * Negative integer: - * SUBST_NAME_IS_VOLUME_JUNCTION: - * The name is a volume junction. - * SUBST_NAME_IS_RELATIVE_LINK: - * The name is a relative symbolic link. - * SUBST_NAME_IS_UNKNOWN: - * The name does not appear to be a valid symbolic link, junction, - * or mount point. - */ -int -parse_substitute_name(const utf16lechar *substitute_name, - u16 substitute_name_nbytes, u32 rptag) -{ - u16 substitute_name_nchars = substitute_name_nbytes / 2; - - if (substitute_name_nchars >= 7 && - substitute_name[0] == cpu_to_le16('\\') && - substitute_name[1] == cpu_to_le16('?') && - substitute_name[2] == cpu_to_le16('?') && - substitute_name[3] == cpu_to_le16('\\') && - substitute_name[4] != cpu_to_le16('\0') && - substitute_name[5] == cpu_to_le16(':') && - substitute_name[6] == cpu_to_le16('\\')) - { - /* "Full" symlink or junction (\??\x:\ prefixed path) */ - return 6; - } else if (rptag == WIM_IO_REPARSE_TAG_MOUNT_POINT && - substitute_name_nchars >= 12 && - memcmp(substitute_name, volume_junction_prefix, - sizeof(volume_junction_prefix)) == 0 && - substitute_name[substitute_name_nchars - 1] == cpu_to_le16('\\')) - { - /* Volume junction. Can't really do anything with it. */ - return SUBST_NAME_IS_VOLUME_JUNCTION; - } else if (rptag == WIM_IO_REPARSE_TAG_SYMLINK && - substitute_name_nchars >= 3 && - substitute_name[0] != cpu_to_le16('\0') && - substitute_name[1] == cpu_to_le16(':') && - substitute_name[2] == cpu_to_le16('\\')) - { - /* "Absolute" symlink, with drive letter */ - return 2; - } else if (rptag == WIM_IO_REPARSE_TAG_SYMLINK && - substitute_name_nchars >= 1) - { - if (substitute_name[0] == cpu_to_le16('\\')) - /* "Absolute" symlink, without drive letter */ - return 0; - else - /* "Relative" symlink, without drive letter */ - return SUBST_NAME_IS_RELATIVE_LINK; - } else { - return SUBST_NAME_IS_UNKNOWN; - } -} - /* * Read the data from a symbolic link, junction, or mount point reparse point * buffer into a `struct reparse_data'. @@ -171,10 +66,10 @@ parse_reparse_data(const u8 * restrict rpbuf, u16 rpbuflen, rpdata->rptag == WIM_IO_REPARSE_TAG_MOUNT_POINT); rpdata->rpdatalen = le16_to_cpu(rpbuf_disk->rpdatalen); rpdata->rpreserved = le16_to_cpu(rpbuf_disk->rpreserved); - substitute_name_offset = le16_to_cpu(rpbuf_disk->substitute_name_offset); - rpdata->substitute_name_nbytes = le16_to_cpu(rpbuf_disk->substitute_name_nbytes); - print_name_offset = le16_to_cpu(rpbuf_disk->print_name_offset); - rpdata->print_name_nbytes = le16_to_cpu(rpbuf_disk->print_name_nbytes); + substitute_name_offset = le16_to_cpu(rpbuf_disk->symlink.substitute_name_offset); + rpdata->substitute_name_nbytes = le16_to_cpu(rpbuf_disk->symlink.substitute_name_nbytes); + print_name_offset = le16_to_cpu(rpbuf_disk->symlink.print_name_offset); + rpdata->print_name_nbytes = le16_to_cpu(rpbuf_disk->symlink.print_name_nbytes); if ((substitute_name_offset & 1) | (print_name_offset & 1) | (rpdata->substitute_name_nbytes & 1) | (rpdata->print_name_nbytes & 1)) @@ -224,10 +119,10 @@ make_reparse_buffer(const struct reparse_data * restrict rpdata, rpbuf_disk->rptag = cpu_to_le32(rpdata->rptag); rpbuf_disk->rpreserved = cpu_to_le16(rpdata->rpreserved); - rpbuf_disk->substitute_name_offset = cpu_to_le16(0); - rpbuf_disk->substitute_name_nbytes = cpu_to_le16(rpdata->substitute_name_nbytes); - rpbuf_disk->print_name_offset = cpu_to_le16(rpdata->substitute_name_nbytes + 2); - rpbuf_disk->print_name_nbytes = cpu_to_le16(rpdata->print_name_nbytes); + rpbuf_disk->symlink.substitute_name_offset = cpu_to_le16(0); + rpbuf_disk->symlink.substitute_name_nbytes = cpu_to_le16(rpdata->substitute_name_nbytes); + rpbuf_disk->symlink.print_name_offset = cpu_to_le16(rpdata->substitute_name_nbytes + 2); + rpbuf_disk->symlink.print_name_nbytes = cpu_to_le16(rpdata->print_name_nbytes); if (rpdata->rptag == WIM_IO_REPARSE_TAG_SYMLINK) { rpbuf_disk->symlink.rpflags = cpu_to_le32(rpdata->rpflags); @@ -321,7 +216,93 @@ wim_inode_get_reparse_data(const struct wim_inode * restrict inode, } /* UNIX version of getting and setting the data in reparse points */ -#if !defined(__WIN32__) +#ifndef __WIN32__ + +static const utf16lechar volume_junction_prefix[11] = { + cpu_to_le16('\\'), + cpu_to_le16('?'), + cpu_to_le16('?'), + cpu_to_le16('\\'), + cpu_to_le16('V'), + cpu_to_le16('o'), + cpu_to_le16('l'), + cpu_to_le16('u'), + cpu_to_le16('m'), + cpu_to_le16('e'), + cpu_to_le16('{'), +}; + +enum { + SUBST_NAME_IS_RELATIVE_LINK = -1, + SUBST_NAME_IS_VOLUME_JUNCTION = -2, + SUBST_NAME_IS_UNKNOWN = -3, +}; + +/* Parse the "substitute name" (link target) from a symbolic link or junction + * reparse point. + * + * Return value is: + * + * Non-negative integer: + * The name is an absolute symbolic link in one of several formats, + * and the return value is the number of UTF-16LE characters that need to + * be advanced to reach a simple "absolute" path starting with a backslash + * (i.e. skip over \??\ and/or drive letter) + * Negative integer: + * SUBST_NAME_IS_VOLUME_JUNCTION: + * The name is a volume junction. + * SUBST_NAME_IS_RELATIVE_LINK: + * The name is a relative symbolic link. + * SUBST_NAME_IS_UNKNOWN: + * The name does not appear to be a valid symbolic link, junction, + * or mount point. + */ +static int +parse_substitute_name(const utf16lechar *substitute_name, + u16 substitute_name_nbytes, u32 rptag) +{ + u16 substitute_name_nchars = substitute_name_nbytes / 2; + + if (substitute_name_nchars >= 7 && + substitute_name[0] == cpu_to_le16('\\') && + substitute_name[1] == cpu_to_le16('?') && + substitute_name[2] == cpu_to_le16('?') && + substitute_name[3] == cpu_to_le16('\\') && + substitute_name[4] != cpu_to_le16('\0') && + substitute_name[5] == cpu_to_le16(':') && + substitute_name[6] == cpu_to_le16('\\')) + { + /* "Full" symlink or junction (\??\x:\ prefixed path) */ + return 6; + } else if (rptag == WIM_IO_REPARSE_TAG_MOUNT_POINT && + substitute_name_nchars >= 12 && + memcmp(substitute_name, volume_junction_prefix, + sizeof(volume_junction_prefix)) == 0 && + substitute_name[substitute_name_nchars - 1] == cpu_to_le16('\\')) + { + /* Volume junction. Can't really do anything with it. */ + return SUBST_NAME_IS_VOLUME_JUNCTION; + } else if (rptag == WIM_IO_REPARSE_TAG_SYMLINK && + substitute_name_nchars >= 3 && + substitute_name[0] != cpu_to_le16('\0') && + substitute_name[1] == cpu_to_le16(':') && + substitute_name[2] == cpu_to_le16('\\')) + { + /* "Absolute" symlink, with drive letter */ + return 2; + } else if (rptag == WIM_IO_REPARSE_TAG_SYMLINK && + substitute_name_nchars >= 1) + { + if (substitute_name[0] == cpu_to_le16('\\')) + /* "Absolute" symlink, without drive letter */ + return 0; + else + /* "Relative" symlink, without drive letter */ + return SUBST_NAME_IS_RELATIVE_LINK; + } else { + return SUBST_NAME_IS_UNKNOWN; + } +} /* * Get the UNIX-style symlink target from the WIM inode for a reparse point. @@ -371,7 +352,7 @@ wim_inode_readlink(const struct wim_inode * restrict inode, return -EIO; if (parse_reparse_data((const u8*)&rpbuf_disk, rpbuflen, &rpdata)) - return -EIO; + return -EINVAL; ret = utf16le_to_tstr(rpdata.substitute_name, rpdata.substitute_name_nbytes, @@ -523,95 +504,4 @@ wim_inode_set_symlink(struct wim_inode *inode, return ret; } -#include - -static int -unix_get_ino_and_dev(const char *path, u64 *ino_ret, u64 *dev_ret) -{ - struct stat stbuf; - if (stat(path, &stbuf)) { - if (errno != ENOENT) - WARNING_WITH_ERRNO("Failed to stat \"%s\"", path); - /* Treat as a link pointing outside the capture root (it - * most likely is). */ - return WIMLIB_ERR_STAT; - } else { - *ino_ret = stbuf.st_ino; - *dev_ret = stbuf.st_dev; - return 0; - } -} - -#endif /* !defined(__WIN32__) */ - -/* is_rp_path_separator() - characters treated as path separators in absolute - * symbolic link targets */ - -#ifdef __WIN32__ -# define is_rp_path_separator(c) ((c) == L'\\' || (c) == L'/') -# define os_get_ino_and_dev win32_get_file_and_vol_ids -#else -# define is_rp_path_separator(c) ((c) == '/') -# define os_get_ino_and_dev unix_get_ino_and_dev -#endif - -/* Fix up absolute symbolic link targets--- mostly shared between UNIX and - * Windows */ -tchar * -capture_fixup_absolute_symlink(tchar *dest, - u64 capture_root_ino, u64 capture_root_dev) -{ - tchar *p = dest; - -#ifdef __WIN32__ - /* Skip drive letter */ - if (!is_rp_path_separator(*dest)) - p += 2; -#endif - - DEBUG("Fixing symlink or junction \"%"TS"\"", dest); - for (;;) { - tchar save; - int ret; - u64 ino; - u64 dev; - - while (is_rp_path_separator(*p)) - p++; - - save = *p; - *p = T('\0'); - ret = os_get_ino_and_dev(dest, &ino, &dev); - *p = save; - - if (ret) /* stat() failed before we got to the capture root--- - assume the link points outside it. */ - return NULL; - - if (ino == capture_root_ino && dev == capture_root_dev) { - /* Link points inside capture root. Return abbreviated - * path. */ - if (*p == T('\0')) - *(p - 1) = OS_PREFERRED_PATH_SEPARATOR; - while (p - 1 >= dest && is_rp_path_separator(*(p - 1))) - p--; - #ifdef __WIN32__ - if (!is_rp_path_separator(dest[0])) { - *--p = dest[1]; - *--p = dest[0]; - } - #endif - wimlib_assert(p >= dest); - return p; - } - - if (*p == T('\0')) { - /* Link points outside capture root. */ - return NULL; - } - - do { - p++; - } while (!is_rp_path_separator(*p) && *p != T('\0')); - } -} +#endif /* !__WIN32__ */