diff options
Diffstat (limited to 'squashfs-tools/xattr.c')
| -rw-r--r-- | squashfs-tools/xattr.c | 1322 |
1 files changed, 1322 insertions, 0 deletions
diff --git a/squashfs-tools/xattr.c b/squashfs-tools/xattr.c new file mode 100644 index 0000000..f9f4cc3 --- /dev/null +++ b/squashfs-tools/xattr.c @@ -0,0 +1,1322 @@ +/* + * Create a squashfs filesystem. This is a highly compressed read only + * filesystem. + * + * Copyright (c) 2008, 2009, 2010, 2012, 2014, 2019, 2021, 2022 + * Phillip Lougher <phillip@squashfs.org.uk> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2, + * or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * xattr.c + */ + +#include "endian_compat.h" + +#define TRUE 1 +#define FALSE 0 + +#include <unistd.h> +#include <stdio.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <errno.h> +#include <dirent.h> +#include <string.h> +#include <stdlib.h> +#include <sys/xattr.h> +#include <regex.h> + +#include "squashfs_fs.h" +#include "squashfs_swap.h" +#include "mksquashfs.h" +#include "xattr.h" +#include "mksquashfs_error.h" +#include "progressbar.h" +#include "pseudo.h" +#include "tar.h" +#include "action.h" +#include "merge_sort.h" + +#ifdef XATTR_NOFOLLOW /* Apple's xattrs */ + #define llistxattr(path_, buf_, sz_) \ + listxattr(path_, buf_, sz_, XATTR_NOFOLLOW) + #define lgetxattr(path_, name_, val_, sz_) \ + getxattr(path_, name_, val_, sz_, 0, XATTR_NOFOLLOW) +#endif + +/* compressed xattr table */ +static char *xattr_table = NULL; +static unsigned int xattr_size = 0; + +/* cached uncompressed xattr data */ +static char *data_cache = NULL; +static int cache_bytes = 0, cache_size = 0; + +/* cached uncompressed xattr id table */ +static struct squashfs_xattr_id *xattr_id_table = NULL; +static int xattr_ids = 0; + +/* saved compressed xattr table */ +unsigned int sxattr_bytes = 0, stotal_xattr_bytes = 0; + +/* saved cached uncompressed xattr data */ +static char *sdata_cache = NULL; +static int scache_bytes = 0; + +/* saved cached uncompressed xattr id table */ +static int sxattr_ids = 0; + +/* xattr hash table for value duplicate detection */ +static struct xattr_list *dupl_value[65536]; + +/* xattr hash table for id duplicate detection */ +static struct dupl_id *dupl_id[65536]; + +/* xattr-add option names and values */ +static struct xattr_add *xattr_add_list = NULL; +static int xattr_add_count = 0; + +/* file system globals from mksquashfs.c */ +extern int no_xattrs, noX; +extern long long bytes; +extern int fd; +extern unsigned int xattr_bytes, total_xattr_bytes; +extern regex_t *xattr_exclude_preg; +extern regex_t *xattr_include_preg; + +/* helper functions from mksquashfs.c */ +extern unsigned short get_checksum(char *, int, unsigned short); +extern void write_destination(int, long long, long long, void *); +extern long long generic_write_table(long long, void *, int, void *, int); +extern int mangle(char *, char *, int, int, int, int); +extern char *pathname(struct dir_ent *); + +/* helper functions and definitions from read_xattrs.c */ +extern unsigned int read_xattrs_from_disk(int, struct squashfs_super_block *, int, long long *); +extern struct xattr_list *get_xattr(int, unsigned int *, int *); +extern struct prefix prefix_table[]; + + +static int xattr_get_type(char *name) +{ + int i; + + for(i = 0; prefix_table[i].type != -1; i++) { + struct prefix *p = &prefix_table[i]; + if(strncmp(name, p->prefix, strlen(p->prefix)) == 0) + break; + } + + return prefix_table[i].type; +} + + +static void xattr_copy_prefix(struct xattr_list *xattr, int t, char *name) +{ + xattr->full_name = strdup(name); + xattr->name = xattr->full_name + strlen(prefix_table[t].prefix); + xattr->size = strlen(xattr->name); +} + + +int xattr_get_prefix(struct xattr_list *xattr, char *name) +{ + int type = xattr_get_type(name); + + if(type != -1) + xattr_copy_prefix(xattr, type, name); + + return type; +} + + +static int read_xattrs_from_system(struct dir_ent *dir_ent, char *filename, + struct xattr_list **xattrs) +{ + ssize_t size, vsize; + char *xattr_names, *p; + int i = 0; + struct xattr_list *xattr_list = NULL; + struct xattr_data *xattr_exc_list; + struct xattr_data *xattr_inc_list; + + while(1) { + size = llistxattr(filename, NULL, 0); + if(size <= 0) { + if(size < 0 && errno != ENOTSUP) { + ERROR_START("llistxattr for %s failed in " + "read_attrs, because %s", filename, + strerror(errno)); + ERROR_EXIT(". Ignoring\n"); + } + return 0; + } + + xattr_names = malloc(size); + if(xattr_names == NULL) + MEM_ERROR(); + + size = llistxattr(filename, xattr_names, size); + if(size < 0) { + free(xattr_names); + if(errno == ERANGE) + /* xattr list grew? Try again */ + continue; + else { + ERROR_START("llistxattr for %s failed in " + "read_attrs, because %s", filename, + strerror(errno)); + ERROR_EXIT(". Ignoring\n"); + return 0; + } + } + + break; + } + + xattr_exc_list = eval_xattr_exc_actions(root_dir, dir_ent); + xattr_inc_list = eval_xattr_inc_actions(root_dir, dir_ent); + + for(p = xattr_names; p < xattr_names + size;) { + struct xattr_list *x; + int res; + + res = match_xattr_exc_actions(xattr_exc_list, p); + if(res) { + p += strlen(p) + 1; + continue; + } + + if(xattr_exclude_preg) { + res = regexec(xattr_exclude_preg, p, (size_t) 0, NULL, 0); + if(res == 0) { + p += strlen(p) + 1; + continue; + } + } + + res = match_xattr_inc_actions(xattr_inc_list, p); + if(res) { + p += strlen(p) + 1; + continue; + } + + if(xattr_include_preg) { + res = regexec(xattr_include_preg, p, (size_t) 0, NULL, 0); + if(res) { + p += strlen(p) + 1; + continue; + } + } + + x = realloc(xattr_list, (i + 1) * sizeof(struct xattr_list)); + if(x == NULL) + MEM_ERROR(); + xattr_list = x; + + xattr_list[i].type = xattr_get_prefix(&xattr_list[i], p); + + if(xattr_list[i].type == -1) { + ERROR("Unrecognised xattr prefix %s\n", p); + p += strlen(p) + 1; + continue; + } + + p += strlen(p) + 1; + + while(1) { + vsize = lgetxattr(filename, xattr_list[i].full_name, + NULL, 0); + if(vsize < 0) { + ERROR_START("lgetxattr failed for %s in " + "read_attrs, because %s", filename, + strerror(errno)); + ERROR_EXIT(". Ignoring\n"); + free(xattr_list[i].full_name); + goto failed; + } + + xattr_list[i].value = malloc(vsize); + if(xattr_list[i].value == NULL) + MEM_ERROR(); + + vsize = lgetxattr(filename, xattr_list[i].full_name, + xattr_list[i].value, vsize); + if(vsize < 0) { + free(xattr_list[i].value); + if(errno == ERANGE) + /* xattr grew? Try again */ + continue; + else { + ERROR_START("lgetxattr failed for %s " + "in read_attrs, because %s", + filename, strerror(errno)); + ERROR_EXIT(". Ignoring\n"); + free(xattr_list[i].full_name); + goto failed; + } + } + + break; + } + + xattr_list[i].vsize = vsize; + + TRACE("read_xattrs_from_system: filename %s, xattr name %s," + " vsize %d\n", filename, xattr_list[i].full_name, + xattr_list[i].vsize); + i++; + } + + free(xattr_names); + + if(i > 0) + *xattrs = xattr_list; + else + free(xattr_list); + return i; + +failed: + while(--i >= 0) { + free(xattr_list[i].full_name); + free(xattr_list[i].value); + } + free(xattr_list); + free(xattr_names); + return 0; +} + + +static int get_xattr_size(struct xattr_list *xattr) +{ + int size = sizeof(struct squashfs_xattr_entry) + + sizeof(struct squashfs_xattr_val) + xattr->size; + + if(xattr->type & XATTR_VALUE_OOL) + size += XATTR_VALUE_OOL_SIZE; + else + size += xattr->vsize; + + return size; +} + + +static void *get_xattr_space(unsigned int req_size, long long *disk) +{ + int data_space; + unsigned short c_byte; + + /* + * Move and compress cached uncompressed data into xattr table. + */ + while(cache_bytes >= SQUASHFS_METADATA_SIZE) { + if((xattr_size - xattr_bytes) < + ((SQUASHFS_METADATA_SIZE << 1)) + 2) { + xattr_table = realloc(xattr_table, xattr_size + + (SQUASHFS_METADATA_SIZE << 1) + 2); + if(xattr_table == NULL) + MEM_ERROR(); + xattr_size += (SQUASHFS_METADATA_SIZE << 1) + 2; + } + + c_byte = mangle(xattr_table + xattr_bytes + BLOCK_OFFSET, + data_cache, SQUASHFS_METADATA_SIZE, + SQUASHFS_METADATA_SIZE, noX, 0); + TRACE("Xattr block @ 0x%x, size %d\n", xattr_bytes, c_byte); + SQUASHFS_SWAP_SHORTS(&c_byte, xattr_table + xattr_bytes, 1); + xattr_bytes += SQUASHFS_COMPRESSED_SIZE(c_byte) + BLOCK_OFFSET; + memmove(data_cache, data_cache + SQUASHFS_METADATA_SIZE, + cache_bytes - SQUASHFS_METADATA_SIZE); + cache_bytes -= SQUASHFS_METADATA_SIZE; + } + + /* + * Ensure there's enough space in the uncompressed data cache + */ + data_space = cache_size - cache_bytes; + if(data_space < req_size) { + int realloc_size = req_size - data_space; + data_cache = realloc(data_cache, cache_size + + realloc_size); + if(data_cache == NULL) + MEM_ERROR(); + cache_size += realloc_size; + } + + if(disk) + *disk = ((long long) xattr_bytes << 16) | cache_bytes; + cache_bytes += req_size; + return data_cache + cache_bytes - req_size; +} + + +static struct dupl_id *check_id_dupl(struct xattr_list *xattr_list, int xattrs) +{ + struct dupl_id *entry; + int i; + unsigned short checksum = 0; + + /* compute checksum over all xattrs */ + for(i = 0; i < xattrs; i++) { + struct xattr_list *xattr = &xattr_list[i]; + + checksum = get_checksum(xattr->full_name, + strlen(xattr->full_name), checksum); + checksum = get_checksum(xattr->value, + xattr->vsize, checksum); + } + + for(entry = dupl_id[checksum]; entry; entry = entry->next) { + if (entry->xattrs != xattrs) + continue; + + for(i = 0; i < xattrs; i++) { + struct xattr_list *xattr = &xattr_list[i]; + struct xattr_list *dup_xattr = &entry->xattr_list[i]; + + if(strcmp(xattr->full_name, dup_xattr->full_name)) + break; + + if(xattr->vsize != dup_xattr->vsize) + break; + + if(memcmp(xattr->value, dup_xattr->value, xattr->vsize)) + break; + } + + if(i == xattrs) + break; + } + + if(entry == NULL) { + /* no duplicate exists */ + entry = malloc(sizeof(*entry)); + if(entry == NULL) + MEM_ERROR(); + entry->xattrs = xattrs; + entry->xattr_list = xattr_list; + entry->xattr_id = SQUASHFS_INVALID_XATTR; + entry->next = dupl_id[checksum]; + dupl_id[checksum] = entry; + } + + return entry; +} + + +static void check_value_dupl(struct xattr_list *xattr) +{ + struct xattr_list *entry; + + if(xattr->vsize < XATTR_VALUE_OOL_SIZE) + return; + + /* Check if this is a duplicate of an existing value */ + xattr->vchecksum = get_checksum(xattr->value, xattr->vsize, 0); + for(entry = dupl_value[xattr->vchecksum]; entry; entry = entry->vnext) { + if(entry->vsize != xattr->vsize) + continue; + + if(memcmp(entry->value, xattr->value, xattr->vsize) == 0) + break; + } + + if(entry == NULL) { + /* + * No duplicate exists, add to hash table, and mark as + * requiring writing + */ + xattr->vnext = dupl_value[xattr->vchecksum]; + dupl_value[xattr->vchecksum] = xattr; + xattr->ool_value = SQUASHFS_INVALID_BLK; + } else { + /* + * Duplicate exists, make type XATTR_VALUE_OOL, and + * remember where the duplicate is + */ + xattr->type |= XATTR_VALUE_OOL; + xattr->ool_value = entry->ool_value; + /* on appending don't free duplicate values because the + * duplicate value already points to the non-duplicate value */ + if(xattr->value != entry->value) { + free(xattr->value); + xattr->value = entry->value; + } + } +} + + +static int get_xattr_id(int xattrs, struct xattr_list *xattr_list, + long long xattr_disk, struct dupl_id *xattr_dupl) +{ + int i, size = 0; + struct squashfs_xattr_id *xattr_id; + + xattr_id_table = realloc(xattr_id_table, (xattr_ids + 1) * + sizeof(struct squashfs_xattr_id)); + if(xattr_id_table == NULL) + MEM_ERROR(); + + /* get total uncompressed size of xattr data, needed for stat */ + for(i = 0; i < xattrs; i++) + size += strlen(xattr_list[i].full_name) + 1 + + xattr_list[i].vsize; + + xattr_id = &xattr_id_table[xattr_ids]; + xattr_id->xattr = xattr_disk; + xattr_id->count = xattrs; + xattr_id->size = size; + + /* + * keep track of total uncompressed xattr data, needed for mksquashfs + * file system summary + */ + total_xattr_bytes += size; + + xattr_dupl->xattr_id = xattr_ids ++; + return xattr_dupl->xattr_id; +} + + +long long write_xattrs() +{ + unsigned short c_byte; + int i, avail_bytes; + char *datap = data_cache; + long long start_bytes = bytes; + struct squashfs_xattr_table header = {}; + + if(xattr_ids == 0) + return SQUASHFS_INVALID_BLK; + + /* + * Move and compress cached uncompressed data into xattr table. + */ + while(cache_bytes) { + if((xattr_size - xattr_bytes) < + ((SQUASHFS_METADATA_SIZE << 1)) + 2) { + xattr_table = realloc(xattr_table, xattr_size + + (SQUASHFS_METADATA_SIZE << 1) + 2); + if(xattr_table == NULL) + MEM_ERROR(); + xattr_size += (SQUASHFS_METADATA_SIZE << 1) + 2; + } + + avail_bytes = cache_bytes > SQUASHFS_METADATA_SIZE ? + SQUASHFS_METADATA_SIZE : cache_bytes; + c_byte = mangle(xattr_table + xattr_bytes + BLOCK_OFFSET, datap, + avail_bytes, SQUASHFS_METADATA_SIZE, noX, 0); + TRACE("Xattr block @ 0x%x, size %d\n", xattr_bytes, c_byte); + SQUASHFS_SWAP_SHORTS(&c_byte, xattr_table + xattr_bytes, 1); + xattr_bytes += SQUASHFS_COMPRESSED_SIZE(c_byte) + BLOCK_OFFSET; + datap += avail_bytes; + cache_bytes -= avail_bytes; + } + + /* + * Write compressed xattr table to file system + */ + write_destination(fd, bytes, xattr_bytes, xattr_table); + bytes += xattr_bytes; + + /* + * Swap if necessary the xattr id table + */ + for(i = 0; i < xattr_ids; i++) + SQUASHFS_INSWAP_XATTR_ID(&xattr_id_table[i]); + + header.xattr_ids = xattr_ids; + header.xattr_table_start = start_bytes; + SQUASHFS_INSWAP_XATTR_TABLE(&header); + + return generic_write_table(xattr_ids * sizeof(struct squashfs_xattr_id), + xattr_id_table, sizeof(header), &header, noX); +} + + +void free_xattr_list(int xattrs, struct xattr_list *xattr_list) +{ + int i; + + for(i = 0; i < xattrs; i++) { + free(xattr_list[i].full_name); + free(xattr_list[i].value); + } + + free(xattr_list); +} + + +int generate_xattrs(int xattrs, struct xattr_list *xattr_list) +{ + int total_size, i; + int xattr_value_max; + void *xp; + long long xattr_disk; + struct dupl_id *xattr_dupl; + + /* + * check if the file xattrs are a complete duplicate of a pre-existing + * id + */ + xattr_dupl = check_id_dupl(xattr_list, xattrs); + if(xattr_dupl->xattr_id != SQUASHFS_INVALID_XATTR) { + free_xattr_list(xattrs, xattr_list); + return xattr_dupl->xattr_id; + } + + /* + * Scan the xattr_list deciding which type to assign to each + * xattr. The choice is fairly straightforward, and depends on the + * size of each xattr name/value and the overall size of the + * resultant xattr list stored in the xattr metadata table. + * + * Choices are whether to store data inline or out of line. + * + * The overall goal is to optimise xattr scanning and lookup, and + * to enable the file system layout to scale from a couple of + * small xattr name/values to a large number of large xattr + * names/values without affecting performance. While hopefully + * enabling the common case of a couple of small xattr name/values + * to be stored efficiently + * + * Code repeatedly scans, doing the following + * move xattr data out of line if it exceeds + * xattr_value_max. Where xattr_value_max is + * initially XATTR_INLINE_MAX. If the final uncompressed + * xattr list is larger than XATTR_TARGET_MAX then more + * aggressively move xattr data out of line by repeatedly + * setting inline threshold to 1/2, then 1/4, 1/8 of + * XATTR_INLINE_MAX until target achieved or there's + * nothing left to move out of line + */ + xattr_value_max = XATTR_INLINE_MAX; + while(1) { + for(total_size = 0, i = 0; i < xattrs; i++) { + struct xattr_list *xattr = &xattr_list[i]; + xattr->type &= XATTR_PREFIX_MASK; /* all inline */ + if (xattr->vsize > xattr_value_max) + xattr->type |= XATTR_VALUE_OOL; + + total_size += get_xattr_size(xattr); + } + + /* + * If the total size of the uncompressed xattr list is <= + * XATTR_TARGET_MAX we're done + */ + if(total_size <= XATTR_TARGET_MAX) + break; + + if(xattr_value_max == XATTR_VALUE_OOL_SIZE) + break; + + /* + * Inline target not yet at minimum and so reduce it, and + * try again + */ + xattr_value_max /= 2; + if(xattr_value_max < XATTR_VALUE_OOL_SIZE) + xattr_value_max = XATTR_VALUE_OOL_SIZE; + } + + /* + * Check xattr values for duplicates + */ + for(i = 0; i < xattrs; i++) { + check_value_dupl(&xattr_list[i]); + } + + /* + * Add each out of line value to the file system xattr table + * if it doesn't already exist as a duplicate + */ + for(i = 0; i < xattrs; i++) { + struct xattr_list *xattr = &xattr_list[i]; + + if((xattr->type & XATTR_VALUE_OOL) && + (xattr->ool_value == SQUASHFS_INVALID_BLK)) { + struct squashfs_xattr_val val; + int size = sizeof(val) + xattr->vsize; + xp = get_xattr_space(size, &xattr->ool_value); + val.vsize = xattr->vsize; + SQUASHFS_SWAP_XATTR_VAL(&val, xp); + memcpy(xp + sizeof(val), xattr->value, xattr->vsize); + } + } + + /* + * Create xattr list and add to file system xattr table + */ + get_xattr_space(0, &xattr_disk); + for(i = 0; i < xattrs; i++) { + struct xattr_list *xattr = &xattr_list[i]; + struct squashfs_xattr_entry entry; + struct squashfs_xattr_val val; + + xp = get_xattr_space(sizeof(entry) + xattr->size, NULL); + entry.type = xattr->type; + entry.size = xattr->size; + SQUASHFS_SWAP_XATTR_ENTRY(&entry, xp); + memcpy(xp + sizeof(entry), xattr->name, xattr->size); + + if(xattr->type & XATTR_VALUE_OOL) { + int size = sizeof(val) + XATTR_VALUE_OOL_SIZE; + xp = get_xattr_space(size, NULL); + val.vsize = XATTR_VALUE_OOL_SIZE; + SQUASHFS_SWAP_XATTR_VAL(&val, xp); + SQUASHFS_SWAP_LONG_LONGS(&xattr->ool_value, xp + + sizeof(val), 1); + } else { + int size = sizeof(val) + xattr->vsize; + xp = get_xattr_space(size, &xattr->ool_value); + val.vsize = xattr->vsize; + SQUASHFS_SWAP_XATTR_VAL(&val, xp); + memcpy(xp + sizeof(val), xattr->value, xattr->vsize); + } + } + + /* + * Add to xattr id lookup table + */ + return get_xattr_id(xattrs, xattr_list, xattr_disk, xattr_dupl); +} + + +/* + * Instantiate two implementations of merge sort with different types and names + */ +SORT(sort_list, xattr_add, name, next); +SORT(sort_xattr_list, xattr_list, full_name, vnext); + + +int read_xattrs(void *d, int type) +{ + struct dir_ent *dir_ent = d; + struct inode_info *inode = dir_ent->inode; + char *filename = pathname(dir_ent); + struct xattr_list *xattr_list = NULL, *head; + int count, i = 0, j; + struct xattr_add *l1 = xattr_add_list, *l2 = NULL, *l3 = NULL; + struct xattr_add *action_add_list; + + if(no_xattrs || inode->root_entry) + return SQUASHFS_INVALID_XATTR; + + if(IS_TARFILE(inode)) + i = read_xattrs_from_tarfile(inode, &xattr_list); + else if(!inode->dummy_root_dir && !IS_PSEUDO(inode)) + i = read_xattrs_from_system(dir_ent, filename, &xattr_list); + + action_add_list = eval_xattr_add_actions(root_dir, dir_ent, &count); + + /* + * At this point we may have up to 3 lists of xattrs: + * + * 1. a list of xattrs created by the global xattrs-add command line + * 2. a list of xattrs created by one or more pseudo xattr definitions + * on this file. + * 3. a list of xattrs created by one or more xattr add actions on this + * file. + * + * The global xattrs are sorted, but, the pseudo xattr list and action + * xattr list are not. + * + * So sort the pseudo and action lists, and merge the three sorted lists + * together whilst adding them to the xattr_list + */ + + if(inode->xattr) { + sort_list(&(inode->xattr->xattr), inode->xattr->count); + l2 = inode->xattr->xattr; + } + + if(action_add_list) { + sort_list(&action_add_list, count); + l3 = action_add_list; + } + + while(l1 || l2 || l3) { + struct xattr_list *x; + struct xattr_add *entry; + + if(l1 && l2 && l3) { + if(strcmp(l1->name, l2->name) <= 0) { + if(strcmp(l1->name, l3->name) <= 0) { + entry= l1; + l1 = l1->next; + } else { + entry = l3; + l3 = l3->next; + } + } else { + if(strcmp(l2->name, l3->name) <= 0) { + entry = l2; + l2 = l2->next; + } else { + entry = l3; + l3 = l3->next; + } + } + } else if(l1 && l2) { + if(strcmp(l1->name, l2->name) <= 0) { + entry = l1; + l1 = l1->next; + } else { + entry = l2; + l2 = l2->next; + } + } else if(l1 && l3) { + if(strcmp(l1->name, l3->name) <= 0) { + entry = l1; + l1 = l1->next; + } else { + entry = l3; + l3 = l3->next; + } + } else if(l2 && l3) { + if(strcmp(l2->name, l3->name) <= 0) { + entry = l2; + l2 = l2->next; + } else { + entry = l3; + l3 = l3->next; + } + } else if(l1) { + entry = l1; + l1 = l1->next; + } else if(l2) { + entry = l2; + l2 = l2->next; + } else { + entry = l3; + l3 = l3->next; + } + + /* + * User extended attributes are only allowed for files and + * directories. See man 7 xattr for explanation. + */ + if((entry->type == SQUASHFS_XATTR_USER) && + (type != SQUASHFS_FILE_TYPE && + type != SQUASHFS_DIR_TYPE)) + continue; + + x = realloc(xattr_list, (i + 1) * sizeof(struct xattr_list)); + if(x == NULL) + MEM_ERROR(); + xattr_list = x; + + xattr_list[i].type = entry->type; + xattr_copy_prefix(&xattr_list[i], entry->type, entry->name); + + xattr_list[i].value = malloc(entry->vsize); + if(xattr_list[i].value == NULL) + MEM_ERROR(); + + memcpy(xattr_list[i].value, entry->value, entry->vsize); + xattr_list[i].vsize = entry->vsize; + + TRACE("read_xattrs: filename %s, xattr name %s," + " vsize %d\n", filename, xattr_list[i].full_name, + xattr_list[i].vsize); + i++; + } + + if(i == 0) + return SQUASHFS_INVALID_XATTR; + else if(i == 1) + goto skip_dup_check; + + /* + * Sort and check xattr list for duplicates + */ + for(j = 1; j < i; j++) + xattr_list[j - 1].vnext = &xattr_list[j]; + + xattr_list[i - 1].vnext = NULL; + head = xattr_list; + + sort_xattr_list(&head, i); + + for(j = 0; j < i - 1; head=head->vnext, j++) + if(strcmp(head->full_name, head->vnext->full_name) == 0) + BAD_ERROR("Duplicate xattr name %s in file %s\n", + head->full_name, filename); + +skip_dup_check: + return generate_xattrs(i, xattr_list); +} + + +/* + * Add the existing xattr ids and xattr metadata in the file system being + * appended to, to the in-memory xattr cache. This allows duplicate checking to + * take place against the xattrs already in the file system being appended to, + * and ensures the pre-existing xattrs are written out along with any new xattrs + */ +int get_xattrs(int fd, struct squashfs_super_block *sBlk) +{ + int res, i, id; + unsigned int count, ids; + + TRACE("get_xattrs\n"); + + if(sBlk->xattr_id_table_start == SQUASHFS_INVALID_BLK) + return SQUASHFS_INVALID_BLK; + + ids = read_xattrs_from_disk(fd, sBlk, FALSE, NULL); + if(ids == 0) + EXIT_MKSQUASHFS(); + + /* + * for each xattr id read and construct its list of xattr + * name:value pairs, and add them to the in-memory xattr cache + */ + for(i = 0; i < ids; i++) { + struct xattr_list *xattr_list = get_xattr(i, &count, &res); + if(xattr_list == NULL && res == FALSE) + EXIT_MKSQUASHFS(); + + if(res) { + free_xattr(xattr_list, count); + return FALSE; + } + id = generate_xattrs(count, xattr_list); + + /* + * Sanity check, the new xattr id should be the same as the + * xattr id in the original file system + */ + if(id != i) { + ERROR("BUG, different xattr_id in get_xattrs\n"); + return FALSE; + } + } + + return TRUE; +} + + +/* + * Save current state of xattrs, needed for restoring state in the event of an + * abort in appending + */ +void save_xattrs() +{ + /* save the current state of the compressed xattr data */ + sxattr_bytes = xattr_bytes; + stotal_xattr_bytes = total_xattr_bytes; + + /* + * save the current state of the cached uncompressed xattr data. + * Note we have to save the contents of the data cache because future + * operations will delete the current contents + */ + sdata_cache = malloc(cache_bytes); + if(sdata_cache == NULL) + MEM_ERROR(); + + memcpy(sdata_cache, data_cache, cache_bytes); + scache_bytes = cache_bytes; + + /* save the current state of the xattr id table */ + sxattr_ids = xattr_ids; +} + + +/* + * Restore xattrs in the event of an abort in appending + */ +void restore_xattrs() +{ + /* restore the state of the compressed xattr data */ + xattr_bytes = sxattr_bytes; + total_xattr_bytes = stotal_xattr_bytes; + + /* restore the state of the uncomoressed xattr data */ + memcpy(data_cache, sdata_cache, scache_bytes); + cache_bytes = scache_bytes; + + /* restore the state of the xattr id table */ + xattr_ids = sxattr_ids; +} + + +regex_t *xattr_regex(char *pattern, char *option) +{ + int error; + regex_t *preg = malloc(sizeof(regex_t)); + + if(preg == NULL) + MEM_ERROR(); + + error = regcomp(preg, pattern, REG_EXTENDED|REG_NOSUB); + + if(error) { + char str[1024]; /* overflow safe */ + + regerror(error, preg, str, 1024); + BAD_ERROR("invalid regex %s in xattrs-%s option, because %s\n", + pattern, option, str); + } + + return preg; +} + + +char *base64_decode(char *source, int size, int *bytes) +{ + char *dest; + unsigned char *dest_ptr, *source_ptr = (unsigned char *) source; + int bit_pos = 0; + int output = 0; + int count; + + if(size % 4 == 0) { + /* Check for and ignore any end padding */ + if(source_ptr[size - 2] == '=' && source_ptr[size - 1] == '=') + size -= 2; + else if(source_ptr[size - 1] == '=') + size --; + } + + /* Calculate number of bytes the base64 encoding represents */ + count = size * 3 / 4; + + dest = malloc(count); + + for(dest_ptr = (unsigned char *) dest; size; size --, source_ptr ++) { + int value = *source_ptr; + + if(value >= 'A' && value <= 'Z') + value -= 'A'; + else if(value >= 'a' && value <= 'z') + value -= 'a' - 26; + else if(value >= '0' && value <= '9') + value -= '0' - 52; + else if(value == '+') + value = 62; + else if(value == '/') + value = 63; + else + goto failed; + + if(bit_pos == 24) { + dest_ptr[0] = output >> 16; + dest_ptr[1] = (output >> 8) & 0xff; + dest_ptr[2] = output & 0xff; + bit_pos = 0; + output = 0; + dest_ptr += 3; + } + + output = (output << 6) | value; + bit_pos += 6; + } + + output = output << (24 - bit_pos); + + if(bit_pos == 6) + goto failed; + + if(bit_pos >= 12) + dest_ptr[0] = output >> 16; + + if(bit_pos >= 18) + dest_ptr[1] = (output >> 8) & 0xff; + + if(bit_pos == 24) + dest_ptr[2] = output & 0xff; + + *bytes = (dest_ptr - (unsigned char *) dest) + (bit_pos / 8); + return dest; + +failed: + free(dest); + return NULL; +} + + +char *hex_decode(char *source, int size, int *bytes) +{ + char *dest; + unsigned char *dest_ptr, *source_ptr = (unsigned char *) source; + int first = 0; + + if(size % 2 != 0) + return NULL; + + dest = malloc(size >> 2); + if(dest == NULL) + MEM_ERROR(); + + for(dest_ptr = (unsigned char *) dest ; size; size --) { + int digit = *source_ptr ++; + + if(digit >= 'A' && digit <= 'F') + digit -= 'A' - 10; + else if(digit >= 'a' && digit <= 'f') + digit -= 'a' - 10; + else if(digit >= '0' && digit <= '9') + digit -= '0'; + else + goto failed; + + if(size % 2 == 0) + first = digit; + else + *dest_ptr ++ = (first << 4) | digit; + } + + *bytes = dest_ptr - (unsigned char *) dest; + + return dest; + +failed: + free(dest); + return NULL; +} + + +int decode_octal(unsigned char *ptr) +{ + int i, output = 0; + + for(i = 0; i < 3; i++) { + int val = *ptr ++; + + if(val < '0' || val > '7') + return -1; + + output = (output << 3) | (val - '0'); + } + + return output < 256 ? output : -1; +} + + +char *text_decode(char *source, int *bytes) +{ + unsigned char *dest, *dest_ptr, *ptr = (unsigned char *) source; + int size = 0; + + for(; *ptr; size ++, ptr ++) { + if(*ptr == '\\') { + if(ptr[1] != '\0' && ptr[2] != '\0' && ptr[3] != '\0') + ptr += 3; + else + return NULL; + } + } + + dest = malloc(size); + if(dest == NULL) + MEM_ERROR(); + + *bytes = size; + + for(ptr = (unsigned char *) source, dest_ptr = dest; size; size --) { + if(*ptr == '\\') { + int res = decode_octal(++ ptr); + + if(res == -1) + goto failed; + + *dest_ptr ++ = res; + ptr += 3; + } else + *dest_ptr ++ = *ptr ++; + } + + return (char *) dest; + +failed: + free(dest); + return NULL; +} + + +struct xattr_add *xattr_parse(char *str, char *pre, char *option) +{ + struct xattr_add *entry; + char *value; + int prefix, size; + + /* + * Look for the "=" separating the xattr name from the value + */ + for(value = str; *value != '=' && *value != '\0'; value ++); + if(*value == '\0') { + ERROR("%sinvalid argument \"%s\" in %s option, because no " + "`=` found\n", pre, str, option); + goto failed; + } + + if(value == str) { + ERROR("%sinvalid argument \"%s\" in %s option, because xattr " + "name is empty\n", pre, str, option); + goto failed; + } + + if(*(value + 1) == '\0') { + ERROR("%sinvalid argument \"%s\" in %s option, because xattr " + "value is empty\n", pre, str, option); + goto failed; + } + + entry = malloc(sizeof(struct xattr_add)); + if(entry == NULL) + MEM_ERROR(); + + entry->name = strndup(str, value++ - str); + entry->type = xattr_get_type(entry->name); + + if(entry->type == -1) { + ERROR("%s%s: unrecognised xattr prefix in %s\n", pre, option, + entry->name); + goto failed2; + } + + /* + * Evaluate the format prefix (if any) + */ + if(*(value + 1) == '\0') + /* + * By definition an xattr value of 1 byte hasn't a prefix, + * and should be treated as binary + */ + prefix = 0; + else + prefix = (*value << 8) + *(value + 1); + + switch(prefix) { + case PREFIX_BASE64_0S: + case PREFIX_BASE64_0s: + value += 2; + if(*value == 0) { + ERROR("%sinvalid argument %s in %s option, because " + "xattr value is empty after format prefix 0S " + "or 0s\n", pre, str, option); + goto failed2; + } + + entry->value = base64_decode(value, strlen(value), &size); + entry->vsize = size; + + if(entry->value == NULL) { + ERROR("%sinvalid argument %s in %s option, because " + "invalid base64 value\n", pre, str, option); + goto failed2; + } + break; + + case PREFIX_HEX_0X: + case PREFIX_HEX_0x: + value += 2; + if(*value == 0) { + ERROR("%sinvalid argument %s in %s option, because " + "xattr value is empty after format prefix 0X " + "or 0x\n", pre, str, option); + goto failed2; + } + + entry->value = hex_decode(value, strlen(value), &size); + entry->vsize = size; + + if(entry->value == NULL) { + ERROR("%sinvalid argument %s in %s option, because " + "invalid hexidecimal value\n", pre, str, option); + goto failed2; + } + break; + + case PREFIX_TEXT_0T: + case PREFIX_TEXT_0t: + value += 2; + if(*value == 0) { + ERROR("%sinvalid argument %s in %s option, because " + "xattr value is empty after format prefix 0T " + "or 0t\n", pre, str, option); + goto failed2; + } + + entry->value = text_decode(value, &size); + entry->vsize = size; + + if(entry->value == NULL) { + ERROR("%sinvalid argument %s in %s option, because " + "invalid text value\n", pre, str, option); + goto failed2; + } + break; + + case PREFIX_BINARY_0B: + case PREFIX_BINARY_0b: + value += 2; + if(*value == 0) { + ERROR("%sinvalid argument %s in %s option, because " + "xattr value is empty after format prefix 0B " + "or 0b\n", pre, str, option); + goto failed2; + } + + /* fall through */ + default: + entry->vsize = strlen(value); + entry->value = malloc(entry->vsize); + + if(entry->value == NULL) + MEM_ERROR(); + + memcpy(entry->value, value, entry->vsize); + } + + return entry; + +failed2: + free(entry->name); + free(entry); +failed: + return NULL; +} + + +void xattrs_add(char *str) +{ + struct xattr_add *entry; + + entry = xattr_parse(str, "FATAL ERROR: ", "xattrs-add"); + + if(entry) { + entry->next = xattr_add_list; + xattr_add_list = entry; + + xattr_add_count ++; + } else + exit(1); +} + + +int add_xattrs(void) { + return xattr_add_count; +} + + +void sort_xattr_add_list(void) +{ + sort_list(&xattr_add_list, xattr_add_count); +} |