X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Freparse.c;h=b097212a6738afd803a911553f112dcb2055667d;hp=4cbe69d9fbda8b7ce7ab43571240b4f2a1a94548;hb=f5d26d6005ba759762bec8c7cd45a738e577a8a7;hpb=9c5469aa171f34e1af510a8a98ec056d27979bbf diff --git a/src/reparse.c b/src/reparse.c index 4cbe69d9..b097212a 100644 --- a/src/reparse.c +++ b/src/reparse.c @@ -1,7 +1,5 @@ /* - * reparse.c - * - * Handle reparse data. + * reparse.c - Handle reparse data. */ /* @@ -23,11 +21,50 @@ * along with wimlib; if not, see http://www.gnu.org/licenses/. */ -#include "dentry.h" -#include "buffer_io.h" -#include "lookup_table.h" -#include "sha1.h" +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#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/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('\\'), @@ -117,37 +154,51 @@ parse_substitute_name(const utf16lechar *substitute_name, * description of the format of the reparse point buffers. */ int -parse_reparse_data(const u8 *rpbuf, u16 rpbuflen, struct reparse_data *rpdata) +parse_reparse_data(const u8 * restrict rpbuf, u16 rpbuflen, + struct reparse_data * restrict rpdata) { - const u8 *p = rpbuf; u16 substitute_name_offset; u16 print_name_offset; + const struct reparse_buffer_disk *rpbuf_disk = + (const struct reparse_buffer_disk*)rpbuf; + const u8 *data; memset(rpdata, 0, sizeof(*rpdata)); if (rpbuflen < 16) goto out_invalid; - p = get_u32(p, &rpdata->rptag); + rpdata->rptag = le32_to_cpu(rpbuf_disk->rptag); wimlib_assert(rpdata->rptag == WIM_IO_REPARSE_TAG_SYMLINK || rpdata->rptag == WIM_IO_REPARSE_TAG_MOUNT_POINT); - p = get_u16(p, &rpdata->rpdatalen); - p = get_u16(p, &rpdata->rpreserved); - p = get_u16(p, &substitute_name_offset); - p = get_u16(p, &rpdata->substitute_name_nbytes); - p = get_u16(p, &print_name_offset); - p = get_u16(p, &rpdata->print_name_nbytes); + 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); + + if ((substitute_name_offset & 1) | (print_name_offset & 1) | + (rpdata->substitute_name_nbytes & 1) | (rpdata->print_name_nbytes & 1)) + { + /* Names would be unaligned... */ + goto out_invalid; + } + if (rpdata->rptag == WIM_IO_REPARSE_TAG_SYMLINK) { if (rpbuflen < 20) goto out_invalid; - p = get_u32(p, &rpdata->rpflags); + rpdata->rpflags = le32_to_cpu(rpbuf_disk->symlink.rpflags); + data = rpbuf_disk->symlink.data; + } else { + data = rpbuf_disk->junction.data; } if ((size_t)substitute_name_offset + rpdata->substitute_name_nbytes + - (p - rpbuf) > rpbuflen) + (data - rpbuf) > rpbuflen) goto out_invalid; if ((size_t)print_name_offset + rpdata->print_name_nbytes + - (p - rpbuf) > rpbuflen) + (data - rpbuf) > rpbuflen) goto out_invalid; - rpdata->substitute_name = (utf16lechar*)&p[substitute_name_offset]; - rpdata->print_name = (utf16lechar*)&p[print_name_offset]; + rpdata->substitute_name = (utf16lechar*)&data[substitute_name_offset]; + rpdata->print_name = (utf16lechar*)&data[print_name_offset]; return 0; out_invalid: ERROR("Invalid reparse data"); @@ -163,34 +214,44 @@ out_invalid: * at least REPARSE_POINT_MAX_SIZE bytes long. */ int -make_reparse_buffer(const struct reparse_data *rpdata, u8 *rpbuf) +make_reparse_buffer(const struct reparse_data * restrict rpdata, + u8 * restrict rpbuf) { - u8 *p = rpbuf; - - p = put_u32(p, rpdata->rptag); - p += 2; /* We set ReparseDataLength later */ - p = put_u16(p, rpdata->rpreserved); - p = put_u16(p, 0); /* substitute name offset */ - p = put_u16(p, rpdata->substitute_name_nbytes); /* substitute name nbytes */ - p = put_u16(p, rpdata->substitute_name_nbytes + 2); /* print name offset */ - p = put_u16(p, rpdata->print_name_nbytes); /* print name nbytes */ - if (rpdata->rptag == WIM_IO_REPARSE_TAG_SYMLINK) - p = put_u32(p, rpdata->rpflags); + struct reparse_buffer_disk *rpbuf_disk = + (struct reparse_buffer_disk*)rpbuf; + u8 *data; + + 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); + + if (rpdata->rptag == WIM_IO_REPARSE_TAG_SYMLINK) { + rpbuf_disk->symlink.rpflags = cpu_to_le32(rpdata->rpflags); + data = rpbuf_disk->symlink.data; + } else { + data = rpbuf_disk->junction.data; + } + /* We null-terminate the substitute and print names, although this may * not be strictly necessary. Note that the byte counts should not * include the null terminators. */ - if (p + rpdata->substitute_name_nbytes + + if (data + rpdata->substitute_name_nbytes + rpdata->print_name_nbytes + 2 * sizeof(utf16lechar) - rpbuf > REPARSE_POINT_MAX_SIZE) { ERROR("Reparse data is too long!"); return WIMLIB_ERR_INVALID_REPARSE_DATA; } - p = put_bytes(p, rpdata->substitute_name_nbytes, rpdata->substitute_name); - p = put_u16(p, 0); - p = put_bytes(p, rpdata->print_name_nbytes, rpdata->print_name); - p = put_u16(p, 0); - put_u16(rpbuf + 4, p - rpbuf - 8); /* Set ReparseDataLength */ + data = mempcpy(data, rpdata->substitute_name, rpdata->substitute_name_nbytes); + *(utf16lechar*)data = cpu_to_le16(0); + data += 2; + data = mempcpy(data, rpdata->print_name, rpdata->print_name_nbytes); + *(utf16lechar*)data = cpu_to_le16(0); + data += 2; + rpbuf_disk->rpdatalen = cpu_to_le16(data - rpbuf - 8); return 0; } @@ -207,10 +268,14 @@ make_reparse_buffer(const struct reparse_data *rpdata, u8 *rpbuf) * buffer returned by this function. */ int -wim_inode_get_reparse_data(const struct wim_inode *inode, u8 *rpbuf) +wim_inode_get_reparse_data(const struct wim_inode * restrict inode, + u8 * restrict rpbuf, + u16 * restrict rpbuflen_ret) { struct wim_lookup_table_entry *lte; int ret; + struct reparse_buffer_disk *rpbuf_disk; + u16 rpdatalen; wimlib_assert(inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT); @@ -219,27 +284,32 @@ wim_inode_get_reparse_data(const struct wim_inode *inode, u8 *rpbuf) ERROR("Reparse point has no reparse data!"); return WIMLIB_ERR_INVALID_REPARSE_DATA; } + if (wim_resource_size(lte) > REPARSE_POINT_MAX_SIZE - 8) { ERROR("Reparse data is too long!"); return WIMLIB_ERR_INVALID_REPARSE_DATA; } + rpdatalen = wim_resource_size(lte); /* Read the data from the WIM file */ - ret = read_full_resource_into_buf(lte, rpbuf + 8, true); + ret = read_full_resource_into_buf(lte, rpbuf + 8); if (ret) return ret; /* Reconstruct the first 8 bytes of the reparse point buffer */ + rpbuf_disk = (struct reparse_buffer_disk*)rpbuf; /* ReparseTag */ - put_u32(rpbuf, inode->i_reparse_tag); + rpbuf_disk->rptag = cpu_to_le32(inode->i_reparse_tag); /* ReparseDataLength */ - put_u16(rpbuf + 4, wim_resource_size(lte)); + rpbuf_disk->rpdatalen = cpu_to_le16(rpdatalen); /* ReparseReserved * XXX this could be one of the unknown fields in the WIM dentry. */ - put_u16(rpbuf + 6, 0); + rpbuf_disk->rpreserved = cpu_to_le16(0); + + *rpbuflen_ret = rpdatalen + 8; return 0; } @@ -254,24 +324,23 @@ wim_inode_get_reparse_data(const struct wim_inode *inode, u8 *rpbuf) * argument is swapped out with the `struct wim_inode' for a reparse point, and * on failure a negated error code is returned rather than -1 with errno set. */ ssize_t -wim_inode_readlink(const struct wim_inode *inode, char *buf, size_t bufsize) +wim_inode_readlink(const struct wim_inode * restrict inode, + char * restrict buf, size_t bufsize) { int ret; - u8 rpbuf[REPARSE_POINT_MAX_SIZE]; - u16 rpdatalen; + struct reparse_buffer_disk rpbuf_disk _aligned_attribute(8); struct reparse_data rpdata; char *link_target; char *translated_target; size_t link_target_len; + u16 rpbuflen; wimlib_assert(inode_is_symlink(inode)); - if (wim_inode_get_reparse_data(inode, rpbuf)) + if (wim_inode_get_reparse_data(inode, (u8*)&rpbuf_disk, &rpbuflen)) return -EIO; - get_u16(rpbuf + 4, &rpdatalen); - - if (parse_reparse_data(rpbuf, rpdatalen + 8, &rpdata)) + if (parse_reparse_data((const u8*)&rpbuf_disk, rpbuflen, &rpdata)) return -EIO; ret = utf16le_to_tstr(rpdata.substitute_name, @@ -292,7 +361,8 @@ wim_inode_readlink(const struct wim_inode *inode, char *buf, size_t bufsize) case SUBST_NAME_IS_UNKNOWN: ERROR("Can't understand reparse point " "substitute name \"%s\"", link_target); - return -EIO; + ret = -EIO; + goto out_free_link_target; default: translated_target += ret; link_target_len -= ret; @@ -311,22 +381,18 @@ out_have_link: ret = link_target_len; } memcpy(buf, translated_target, link_target_len); +out_free_link_target: FREE(link_target); return ret; } -#ifdef HAVE_ALLOCA_H -# include -#endif - int wim_inode_set_symlink(struct wim_inode *inode, const char *target, struct wim_lookup_table *lookup_table) { - u8 rpbuf[REPARSE_POINT_MAX_SIZE]; - u16 rpdatalen; + struct reparse_buffer_disk rpbuf_disk _aligned_attribute(8); struct reparse_data rpdata; static const char abs_subst_name_prefix[12] = "\\\0?\0?\0\\\0C\0:\0"; static const char abs_print_name_prefix[4] = "C\0:\0"; @@ -415,10 +481,11 @@ wim_inode_set_symlink(struct wim_inode *inode, rpdata.rpflags = SYMBOLIC_LINK_RELATIVE; } - ret = make_reparse_buffer(&rpdata, rpbuf); + ret = make_reparse_buffer(&rpdata, (u8*)&rpbuf_disk); if (ret == 0) { - get_u16(rpbuf + 4, &rpdatalen); - ret = inode_set_unnamed_stream(inode, rpbuf + 8, rpdatalen, + ret = inode_set_unnamed_stream(inode, + (u8*)&rpbuf_disk + 8, + le16_to_cpu(rpbuf_disk.rpdatalen), lookup_table); } FREE(name_utf16le); @@ -447,7 +514,6 @@ unix_get_ino_and_dev(const char *path, u64 *ino_ret, u64 *dev_ret) #endif /* !defined(__WIN32__) */ #ifdef __WIN32__ -# include "win32.h" # define RP_PATH_SEPARATOR L'\\' # define is_rp_path_separator(c) ((c) == L'\\' || (c) == L'/') # define os_get_ino_and_dev win32_get_file_and_vol_ids