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xattrs.c
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/*
* Extended Attribute support for rsync.
* Written by Jay Fenlason, vaguely based on the ACLs patch.
*
* Copyright (C) 2004 Red Hat, Inc.
* Copyright (C) 2006-2020 Wayne Davison
*
* 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 3 of the License, 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, visit the http://fsf.org website.
*/
#include "rsync.h"
#include "ifuncs.h"
#include "inums.h"
#include "lib/sysxattrs.h"
#ifdef SUPPORT_XATTRS
extern int dry_run;
extern int am_root;
extern int am_sender;
extern int am_generator;
extern int read_only;
extern int list_only;
extern int preserve_xattrs;
extern int preserve_links;
extern int preserve_devices;
extern int preserve_specials;
extern int checksum_seed;
extern int saw_xattr_filter;
#define RSYNC_XAL_INITIAL 5
#define RSYNC_XAL_LIST_INITIAL 100
#define MAX_FULL_DATUM 32
#define HAS_PREFIX(str, prfx) (*(str) == *(prfx) && strncmp(str, prfx, sizeof (prfx) - 1) == 0)
#define XATTR_ABBREV(x) ((size_t)((x).name - (x).datum) < (x).datum_len)
#define XSTATE_ABBREV 1
#define XSTATE_DONE 2
#define XSTATE_TODO 3
#define USER_PREFIX "user."
#define UPRE_LEN ((int)sizeof USER_PREFIX - 1)
#define SYSTEM_PREFIX "system."
#define SPRE_LEN ((int)sizeof SYSTEM_PREFIX - 1)
#ifdef HAVE_LINUX_XATTRS
#define MIGHT_NEED_RPRE (am_root <= 0)
#define RSYNC_PREFIX USER_PREFIX "rsync."
#else
#define MIGHT_NEED_RPRE am_root
#define RSYNC_PREFIX "rsync."
#endif
#define RPRE_LEN ((int)sizeof RSYNC_PREFIX - 1)
#define XSTAT_SUFFIX "stat"
#define XSTAT_ATTR RSYNC_PREFIX "%" XSTAT_SUFFIX
#define XACC_ACL_SUFFIX "aacl"
#define XACC_ACL_ATTR RSYNC_PREFIX "%" XACC_ACL_SUFFIX
#define XDEF_ACL_SUFFIX "dacl"
#define XDEF_ACL_ATTR RSYNC_PREFIX "%" XDEF_ACL_SUFFIX
typedef struct {
char *datum, *name;
size_t datum_len, name_len;
int num;
} rsync_xa;
struct _rsync_xa_list;
typedef struct _rsync_xa_list_ref {
struct _rsync_xa_list_ref *next;
int ndx;
} rsync_xa_list_ref;
typedef struct _rsync_xa_list {
int ndx;
int64 key;
item_list xa_items;
} rsync_xa_list;
static size_t namebuf_len = 0;
static char *namebuf = NULL;
static const rsync_xa_list empty_xa_list = {
.xa_items = EMPTY_ITEM_LIST,
};
static const item_list empty_xattr = EMPTY_ITEM_LIST;
static item_list rsync_xal_l = EMPTY_ITEM_LIST;
static struct hashtable *rsync_xal_h = NULL;
static size_t prior_xattr_count = (size_t)-1;
/* ------------------------------------------------------------------------- */
static void rsync_xal_free(item_list *xalp)
{
size_t i;
rsync_xa *rxas = xalp->items;
if (!xalp->malloced)
return;
for (i = 0; i < xalp->count; i++) {
free(rxas[i].datum);
/*free(rxas[i].name);*/
}
free(xalp->items);
}
void free_xattr(stat_x *sxp)
{
if (!sxp->xattr)
return;
rsync_xal_free(sxp->xattr);
free(sxp->xattr);
sxp->xattr = NULL;
}
static int rsync_xal_compare_names(const void *x1, const void *x2)
{
const rsync_xa *xa1 = x1;
const rsync_xa *xa2 = x2;
return strcmp(xa1->name, xa2->name);
}
static ssize_t get_xattr_names(const char *fname)
{
ssize_t list_len;
int64 arg;
if (!namebuf) {
namebuf_len = 1024;
namebuf = new_array(char, namebuf_len);
}
while (1) {
/* The length returned includes all the '\0' terminators. */
list_len = sys_llistxattr(fname, namebuf, namebuf_len);
if (list_len >= 0) {
if ((size_t)list_len <= namebuf_len)
break;
} else if (errno == ENOTSUP)
return 0;
else if (errno != ERANGE) {
arg = namebuf_len;
got_error:
rsyserr(FERROR_XFER, errno,
"get_xattr_names: llistxattr(%s,%s) failed",
full_fname(fname), big_num(arg));
return -1;
}
list_len = sys_llistxattr(fname, NULL, 0);
if (list_len < 0) {
arg = 0;
goto got_error;
}
if (namebuf_len)
free(namebuf);
namebuf_len = list_len + 1024;
namebuf = new_array(char, namebuf_len);
}
return list_len;
}
/* On entry, the *len_ptr parameter contains the size of the extra space we
* should allocate when we create a buffer for the data. On exit, it contains
* the length of the datum. */
static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr, int no_missing_error)
{
size_t datum_len = sys_lgetxattr(fname, name, NULL, 0);
size_t extra_len = *len_ptr;
char *ptr;
*len_ptr = datum_len;
if (datum_len == (size_t)-1) {
if (errno == ENOTSUP || no_missing_error)
return NULL;
rsyserr(FERROR_XFER, errno,
"get_xattr_data: lgetxattr(%s,\"%s\",0) failed",
full_fname(fname), name);
return NULL;
}
if (!datum_len && !extra_len)
extra_len = 1; /* request non-zero amount of memory */
if (SIZE_MAX - datum_len < extra_len)
overflow_exit("get_xattr_data");
ptr = new_array(char, datum_len + extra_len);
if (datum_len) {
size_t len = sys_lgetxattr(fname, name, ptr, datum_len);
if (len != datum_len) {
if (len == (size_t)-1) {
rsyserr(FERROR_XFER, errno,
"get_xattr_data: lgetxattr(%s,\"%s\",%ld) failed",
full_fname(fname), name, (long)datum_len);
} else {
rprintf(FERROR_XFER,
"get_xattr_data: lgetxattr(%s,\"%s\",%ld) returned %ld\n",
full_fname(fname), name,
(long)datum_len, (long)len);
}
free(ptr);
return NULL;
}
}
return ptr;
}
static int rsync_xal_get(const char *fname, item_list *xalp)
{
ssize_t list_len, name_len;
size_t datum_len, name_offset;
char *name, *ptr;
#ifdef HAVE_LINUX_XATTRS
int user_only = am_sender ? 0 : !am_root;
#endif
rsync_xa *rxa;
int count;
/* This puts the name list into the "namebuf" buffer. */
if ((list_len = get_xattr_names(fname)) < 0)
return -1;
for (name = namebuf; list_len > 0; name += name_len) {
name_len = strlen(name) + 1;
list_len -= name_len;
if (saw_xattr_filter) {
if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
continue;
}
#ifdef HAVE_LINUX_XATTRS
/* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
continue;
#endif
/* No rsync.%FOO attributes are copied w/o 2 -X options. */
if (name_len > RPRE_LEN && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
if ((am_sender && preserve_xattrs < 2)
|| (am_root < 0
&& (strcmp(name+RPRE_LEN+1, XSTAT_SUFFIX) == 0
|| strcmp(name+RPRE_LEN+1, XACC_ACL_SUFFIX) == 0
|| strcmp(name+RPRE_LEN+1, XDEF_ACL_SUFFIX) == 0)))
continue;
}
datum_len = name_len; /* Pass extra size to get_xattr_data() */
if (!(ptr = get_xattr_data(fname, name, &datum_len, 0)))
return -1;
if (datum_len > MAX_FULL_DATUM) {
/* For large datums, we store a flag and a checksum. */
name_offset = 1 + MAX_DIGEST_LEN;
sum_init(-1, checksum_seed);
sum_update(ptr, datum_len);
free(ptr);
ptr = new_array(char, name_offset + name_len);
*ptr = XSTATE_ABBREV;
sum_end(ptr + 1);
} else
name_offset = datum_len;
rxa = EXPAND_ITEM_LIST(xalp, rsync_xa, RSYNC_XAL_INITIAL);
rxa->name = ptr + name_offset;
memcpy(rxa->name, name, name_len);
rxa->datum = ptr;
rxa->name_len = name_len;
rxa->datum_len = datum_len;
}
count = xalp->count;
rxa = xalp->items;
if (count > 1)
qsort(rxa, count, sizeof (rsync_xa), rsync_xal_compare_names);
for (rxa += count-1; count; count--, rxa--)
rxa->num = count;
return 0;
}
/* Read the xattr(s) for this filename. */
int get_xattr(const char *fname, stat_x *sxp)
{
sxp->xattr = new(item_list);
*sxp->xattr = empty_xattr;
if (S_ISREG(sxp->st.st_mode) || S_ISDIR(sxp->st.st_mode)) {
/* Everyone supports this. */
} else if (S_ISLNK(sxp->st.st_mode)) {
#ifndef NO_SYMLINK_XATTRS
if (!preserve_links)
#endif
return 0;
} else if (IS_SPECIAL(sxp->st.st_mode)) {
#ifndef NO_SPECIAL_XATTRS
if (!preserve_specials)
#endif
return 0;
} else if (IS_DEVICE(sxp->st.st_mode)) {
#ifndef NO_DEVICE_XATTRS
if (!preserve_devices)
#endif
return 0;
} else if (IS_MISSING_FILE(sxp->st))
return 0;
if (rsync_xal_get(fname, sxp->xattr) < 0) {
free_xattr(sxp);
return -1;
}
return 0;
}
int copy_xattrs(const char *source, const char *dest)
{
ssize_t list_len, name_len;
size_t datum_len;
char *name, *ptr;
#ifdef HAVE_LINUX_XATTRS
int user_only = am_sender ? 0 : am_root <= 0;
#endif
/* This puts the name list into the "namebuf" buffer. */
if ((list_len = get_xattr_names(source)) < 0)
return -1;
for (name = namebuf; list_len > 0; name += name_len) {
name_len = strlen(name) + 1;
list_len -= name_len;
if (saw_xattr_filter) {
if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
continue;
}
#ifdef HAVE_LINUX_XATTRS
/* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
continue;
#endif
datum_len = 0;
if (!(ptr = get_xattr_data(source, name, &datum_len, 0)))
return -1;
if (sys_lsetxattr(dest, name, ptr, datum_len) < 0) {
int save_errno = errno ? errno : EINVAL;
rsyserr(FERROR_XFER, errno,
"copy_xattrs: lsetxattr(%s,\"%s\") failed",
full_fname(dest), name);
errno = save_errno;
return -1;
}
free(ptr);
}
return 0;
}
static int64 xattr_lookup_hash(const item_list *xalp)
{
const rsync_xa *rxas = xalp->items;
size_t i;
int64 key = hashlittle(&xalp->count, sizeof xalp->count);
for (i = 0; i < xalp->count; i++) {
key += hashlittle(rxas[i].name, rxas[i].name_len);
if (rxas[i].datum_len > MAX_FULL_DATUM)
key += hashlittle(rxas[i].datum, MAX_DIGEST_LEN);
else
key += hashlittle(rxas[i].datum, rxas[i].datum_len);
}
if (key == 0) {
/* This is very unlikely, but we should never
* return 0 as hashtable_find() doesn't like it. */
return 1;
}
return key;
}
static int find_matching_xattr(const item_list *xalp)
{
const struct ht_int64_node *node;
const rsync_xa_list_ref *ref;
int64 key;
if (rsync_xal_h == NULL)
return -1;
key = xattr_lookup_hash(xalp);
node = hashtable_find(rsync_xal_h, key, NULL);
if (node == NULL)
return -1;
if (node->data == NULL)
return -1;
for (ref = node->data; ref != NULL; ref = ref->next) {
const rsync_xa_list *ptr = rsync_xal_l.items;
const rsync_xa *rxas1;
const rsync_xa *rxas2 = xalp->items;
size_t j;
ptr += ref->ndx;
rxas1 = ptr->xa_items.items;
/* Wrong number of elements? */
if (ptr->xa_items.count != xalp->count)
continue;
/* any elements different? */
for (j = 0; j < xalp->count; j++) {
if (rxas1[j].name_len != rxas2[j].name_len
|| rxas1[j].datum_len != rxas2[j].datum_len
|| strcmp(rxas1[j].name, rxas2[j].name))
break;
if (rxas1[j].datum_len > MAX_FULL_DATUM) {
if (memcmp(rxas1[j].datum + 1,
rxas2[j].datum + 1,
MAX_DIGEST_LEN) != 0)
break;
} else {
if (memcmp(rxas1[j].datum, rxas2[j].datum,
rxas2[j].datum_len))
break;
}
}
/* no differences found. This is The One! */
if (j == xalp->count)
return ref->ndx;
}
return -1;
}
/* Store *xalp on the end of rsync_xal_l */
static int rsync_xal_store(item_list *xalp)
{
struct ht_int64_node *node;
int ndx = rsync_xal_l.count; /* pre-incremented count */
rsync_xa_list *new_list = EXPAND_ITEM_LIST(&rsync_xal_l, rsync_xa_list, RSYNC_XAL_LIST_INITIAL);
rsync_xa_list_ref *new_ref;
/* Since the following call starts a new list, we know it will hold the
* entire initial-count, not just enough space for one new item. */
*new_list = empty_xa_list;
(void)EXPAND_ITEM_LIST(&new_list->xa_items, rsync_xa, xalp->count);
memcpy(new_list->xa_items.items, xalp->items, xalp->count * sizeof (rsync_xa));
new_list->xa_items.count = xalp->count;
xalp->count = 0;
new_list->ndx = ndx;
new_list->key = xattr_lookup_hash(&new_list->xa_items);
if (rsync_xal_h == NULL)
rsync_xal_h = hashtable_create(512, HT_KEY64);
if (rsync_xal_h == NULL)
out_of_memory("rsync_xal_h hashtable_create()");
new_ref = new0(rsync_xa_list_ref);
new_ref->ndx = ndx;
node = hashtable_find(rsync_xal_h, new_list->key, new_ref);
if (node->data != (void*)new_ref) {
rsync_xa_list_ref *ref = node->data;
while (ref != NULL) {
if (ref->next != NULL) {
ref = ref->next;
continue;
}
ref->next = new_ref;
break;
}
}
return ndx;
}
/* Send the make_xattr()-generated xattr list for this flist entry. */
int send_xattr(int f, stat_x *sxp)
{
int ndx = find_matching_xattr(sxp->xattr);
/* Send 0 (-1 + 1) to indicate that literal xattr data follows. */
write_varint(f, ndx + 1);
if (ndx < 0) {
rsync_xa *rxa;
int count = sxp->xattr->count;
write_varint(f, count);
for (rxa = sxp->xattr->items; count--; rxa++) {
size_t name_len = rxa->name_len;
const char *name = rxa->name;
/* Strip the rsync prefix from disguised namespaces. */
if (name_len > RPRE_LEN
#ifdef HAVE_LINUX_XATTRS
&& am_root < 0
#endif
&& name[RPRE_LEN] != '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
name += RPRE_LEN;
name_len -= RPRE_LEN;
}
#ifndef HAVE_LINUX_XATTRS
else {
/* Put everything else in the user namespace. */
name_len += UPRE_LEN;
}
#endif
write_varint(f, name_len);
write_varint(f, rxa->datum_len);
#ifndef HAVE_LINUX_XATTRS
if (name_len > rxa->name_len) {
write_buf(f, USER_PREFIX, UPRE_LEN);
name_len -= UPRE_LEN;
}
#endif
write_buf(f, name, name_len);
if (rxa->datum_len > MAX_FULL_DATUM)
write_buf(f, rxa->datum + 1, MAX_DIGEST_LEN);
else
write_bigbuf(f, rxa->datum, rxa->datum_len);
}
ndx = rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
}
return ndx;
}
/* Return a flag indicating if we need to change a file's xattrs. If
* "find_all" is specified, also mark any abbreviated xattrs that we
* need so that send_xattr_request() can tell the sender about them. */
int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
{
const rsync_xa_list *glst = rsync_xal_l.items;
const item_list *lst;
rsync_xa *snd_rxa, *rec_rxa;
int snd_cnt, rec_cnt;
int cmp, same, xattrs_equal = 1;
if (sxp && XATTR_READY(*sxp)) {
rec_rxa = sxp->xattr->items;
rec_cnt = sxp->xattr->count;
} else {
rec_rxa = NULL;
rec_cnt = 0;
}
if (F_XATTR(file) >= 0) {
glst += F_XATTR(file);
lst = &glst->xa_items;
} else
lst = &empty_xattr;
snd_rxa = lst->items;
snd_cnt = lst->count;
/* If the count of the sender's xattrs is different from our
* (receiver's) xattrs, the lists are not the same. */
if (snd_cnt != rec_cnt) {
if (!find_all)
return 1;
xattrs_equal = 0;
}
while (snd_cnt) {
cmp = rec_cnt ? strcmp(snd_rxa->name, rec_rxa->name) : -1;
if (cmp > 0)
same = 0;
else if (snd_rxa->datum_len > MAX_FULL_DATUM) {
same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
&& memcmp(snd_rxa->datum + 1, rec_rxa->datum + 1,
MAX_DIGEST_LEN) == 0;
/* Flag unrequested items that we need. */
if (!same && find_all && snd_rxa->datum[0] == XSTATE_ABBREV)
snd_rxa->datum[0] = XSTATE_TODO;
} else {
same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
&& memcmp(snd_rxa->datum, rec_rxa->datum,
snd_rxa->datum_len) == 0;
}
if (!same) {
if (!find_all)
return 1;
xattrs_equal = 0;
}
if (cmp <= 0) {
snd_rxa++;
snd_cnt--;
}
if (cmp >= 0) {
rec_rxa++;
rec_cnt--;
}
}
if (rec_cnt)
xattrs_equal = 0;
return !xattrs_equal;
}
/* When called by the generator (with a NULL fname), this tells the sender
* all the abbreviated xattr values we need. When called by the sender
* (with a non-NULL fname), we send all the extra xattr data it needs.
* The generator may also call with f_out < 0 to just change all the
* XSTATE_ABBREV states into XSTATE_DONE. */
void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
{
const rsync_xa_list *glst = rsync_xal_l.items;
const item_list *lst;
int cnt, prior_req = 0;
rsync_xa *rxa;
glst += F_XATTR(file);
lst = &glst->xa_items;
for (rxa = lst->items, cnt = lst->count; cnt--; rxa++) {
if (rxa->datum_len <= MAX_FULL_DATUM)
continue;
switch (rxa->datum[0]) {
case XSTATE_ABBREV:
/* Items left abbreviated matched the sender's checksum, so
* the receiver will cache the local data for future use. */
if (am_generator)
rxa->datum[0] = XSTATE_DONE;
continue;
case XSTATE_TODO:
assert(f_out >= 0);
break;
default:
continue;
}
/* Flag that we handled this abbreviated item. */
rxa->datum[0] = XSTATE_DONE;
write_varint(f_out, rxa->num - prior_req);
prior_req = rxa->num;
if (fname) {
size_t len = 0;
char *ptr;
/* Re-read the long datum. */
if (!(ptr = get_xattr_data(fname, rxa->name, &len, 0))) {
rprintf(FERROR_XFER, "failed to re-read xattr %s for %s\n", rxa->name, fname);
write_varint(f_out, 0);
continue;
}
write_varint(f_out, len); /* length might have changed! */
write_bigbuf(f_out, ptr, len);
free(ptr);
}
}
if (f_out >= 0)
write_byte(f_out, 0); /* end the list */
}
/* When called by the sender, read the request from the generator and mark
* any needed xattrs with a flag that lets us know they need to be sent to
* the receiver. When called by the receiver, reads the sent data and
* stores it in place of its checksum. */
int recv_xattr_request(struct file_struct *file, int f_in)
{
const rsync_xa_list *glst = rsync_xal_l.items;
const item_list *lst;
char *old_datum, *name;
rsync_xa *rxa;
int rel_pos, cnt, num, got_xattr_data = 0;
if (F_XATTR(file) < 0) {
rprintf(FERROR, "recv_xattr_request: internal data error!\n");
exit_cleanup(RERR_PROTOCOL);
}
glst += F_XATTR(file);
lst = &glst->xa_items;
cnt = lst->count;
rxa = lst->items;
num = 0;
while ((rel_pos = read_varint(f_in)) != 0) {
num += rel_pos;
if (am_sender) {
/* The sender-related num values are only in order on the sender.
* We use that order here to scan forward or backward as needed. */
if (rel_pos < 0) {
while (cnt < (int)lst->count && rxa->num > num) {
rxa--;
cnt++;
}
} else {
while (cnt > 1 && rxa->num < num) {
rxa++;
cnt--;
}
}
} else {
int j;
/* The receiving side has no known num order, so we just scan
* forward (w/wrap) and hope that the next value is near by. */
for (j = lst->count; j > 1 && rxa->num != num; j--) {
if (--cnt)
rxa++;
else {
cnt = lst->count;
rxa = lst->items;
}
}
}
if (!cnt || rxa->num != num) {
rprintf(FERROR, "[%s] could not find xattr #%d for %s\n",
who_am_i(), num, f_name(file, NULL));
exit_cleanup(RERR_PROTOCOL);
}
if (!XATTR_ABBREV(*rxa) || rxa->datum[0] != XSTATE_ABBREV) {
rprintf(FERROR, "[%s] internal abbrev error on %s (%s, len=%ld)!\n",
who_am_i(), f_name(file, NULL), rxa->name, (long)rxa->datum_len);
exit_cleanup(RERR_PROTOCOL);
}
if (am_sender) {
rxa->datum[0] = XSTATE_TODO;
continue;
}
old_datum = rxa->datum;
rxa->datum_len = read_varint(f_in);
if (SIZE_MAX - rxa->name_len < rxa->datum_len)
overflow_exit("recv_xattr_request");
rxa->datum = new_array(char, rxa->datum_len + rxa->name_len);
name = rxa->datum + rxa->datum_len;
memcpy(name, rxa->name, rxa->name_len);
rxa->name = name;
free(old_datum);
read_buf(f_in, rxa->datum, rxa->datum_len);
got_xattr_data = 1;
}
return got_xattr_data;
}
/* ------------------------------------------------------------------------- */
/* receive and build the rsync_xattr_lists */
void receive_xattr(int f, struct file_struct *file)
{
static item_list temp_xattr = EMPTY_ITEM_LIST;
int count, num;
#ifdef HAVE_LINUX_XATTRS
int need_sort = 0;
#else
int need_sort = 1;
#endif
int ndx = read_varint(f);
if (ndx < 0 || (size_t)ndx > rsync_xal_l.count) {
rprintf(FERROR, "receive_xattr: xa index %d out of"
" range for %s\n", ndx, f_name(file, NULL));
exit_cleanup(RERR_STREAMIO);
}
if (ndx != 0) {
F_XATTR(file) = ndx - 1;
return;
}
if ((count = read_varint(f)) != 0) {
(void)EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, count);
temp_xattr.count = 0;
}
for (num = 1; num <= count; num++) {
char *ptr, *name;
rsync_xa *rxa;
size_t name_len = read_varint(f);
size_t datum_len = read_varint(f);
size_t dget_len = datum_len > MAX_FULL_DATUM ? 1 + MAX_DIGEST_LEN : datum_len;
size_t extra_len = MIGHT_NEED_RPRE ? RPRE_LEN : 0;
if (SIZE_MAX - dget_len < extra_len || SIZE_MAX - dget_len - extra_len < name_len)
overflow_exit("receive_xattr");
ptr = new_array(char, dget_len + extra_len + name_len);
name = ptr + dget_len + extra_len;
read_buf(f, name, name_len);
if (name_len < 1 || name[name_len-1] != '\0') {
rprintf(FERROR, "Invalid xattr name received (missing trailing \\0).\n");
exit_cleanup(RERR_FILEIO);
}
if (dget_len == datum_len)
read_buf(f, ptr, dget_len);
else {
*ptr = XSTATE_ABBREV;
read_buf(f, ptr + 1, MAX_DIGEST_LEN);
}
if (saw_xattr_filter) {
if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS)) {
free(ptr);
continue;
}
}
#ifdef HAVE_LINUX_XATTRS
/* Non-root can only save the user namespace. */
if (am_root <= 0 && !HAS_PREFIX(name, USER_PREFIX)) {
if (!am_root && !saw_xattr_filter) {
free(ptr);
continue;
}
name -= RPRE_LEN;
name_len += RPRE_LEN;
memcpy(name, RSYNC_PREFIX, RPRE_LEN);
need_sort = 1;
}
#else
/* This OS only has a user namespace, so we either
* strip the user prefix, or we put a non-user
* namespace inside our rsync hierarchy. */
if (HAS_PREFIX(name, USER_PREFIX)) {
name += UPRE_LEN;
name_len -= UPRE_LEN;
} else if (am_root) {
name -= RPRE_LEN;
name_len += RPRE_LEN;
memcpy(name, RSYNC_PREFIX, RPRE_LEN);
} else {
free(ptr);
continue;
}
#endif
/* No rsync.%FOO attributes are copied w/o 2 -X options. */
if (preserve_xattrs < 2 && name_len > RPRE_LEN
&& name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
free(ptr);
continue;
}
rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, 1);
rxa->name = name;
rxa->datum = ptr;
rxa->name_len = name_len;
rxa->datum_len = datum_len;
rxa->num = num;
}
if (need_sort && count > 1)
qsort(temp_xattr.items, count, sizeof (rsync_xa), rsync_xal_compare_names);
ndx = rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
F_XATTR(file) = ndx;
}
/* Turn the xattr data in stat_x into cached xattr data, setting the index
* values in the file struct. */
void cache_tmp_xattr(struct file_struct *file, stat_x *sxp)
{
int ndx;
if (!sxp->xattr)
return;
if (prior_xattr_count == (size_t)-1)
prior_xattr_count = rsync_xal_l.count;
ndx = find_matching_xattr(sxp->xattr);
if (ndx < 0)
rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
F_XATTR(file) = ndx;
}
void uncache_tmp_xattrs(void)
{
if (prior_xattr_count != (size_t)-1) {
rsync_xa_list *xa_list_item = rsync_xal_l.items;
rsync_xa_list *xa_list_start = xa_list_item + prior_xattr_count;
xa_list_item += rsync_xal_l.count;
rsync_xal_l.count = prior_xattr_count;
while (xa_list_item-- > xa_list_start) {
struct ht_int64_node *node;
rsync_xa_list_ref *ref;
rsync_xal_free(&xa_list_item->xa_items);
if (rsync_xal_h == NULL)
continue;
node = hashtable_find(rsync_xal_h, xa_list_item->key, NULL);
if (node == NULL)
continue;
if (node->data == NULL)
continue;
ref = node->data;
if (xa_list_item->ndx == ref->ndx) {
/* xa_list_item is the first in the list. */
node->data = ref->next;
free(ref);
continue;
}
while (1) {
rsync_xa_list_ref *next = ref->next;
if (next == NULL)
break;
if (xa_list_item->ndx == next->ndx) {
ref->next = next->next;
free(next);
break;
}
ref = next;
}
}
prior_xattr_count = (size_t)-1;
}
}
static int rsync_xal_set(const char *fname, item_list *xalp,
const char *fnamecmp, stat_x *sxp)
{
rsync_xa *rxas = xalp->items;
ssize_t list_len;
size_t i, len;
char *name, *ptr, sum[MAX_DIGEST_LEN];
#ifdef HAVE_LINUX_XATTRS
int user_only = am_root <= 0;
#endif
size_t name_len;
int ret = 0;
/* This puts the current name list into the "namebuf" buffer. */
if ((list_len = get_xattr_names(fname)) < 0)
return -1;
for (i = 0; i < xalp->count; i++) {
name = rxas[i].name;
if (XATTR_ABBREV(rxas[i])) {
int sum_len;
/* See if the fnamecmp version is identical. */
len = name_len = rxas[i].name_len;
if ((ptr = get_xattr_data(fnamecmp, name, &len, 1)) == NULL) {
still_abbrev:
if (am_generator)
continue;
rprintf(FERROR, "Missing abbreviated xattr value, %s, for %s\n",
rxas[i].name, full_fname(fname));
ret = -1;
continue;
}
if (len != rxas[i].datum_len) {
free(ptr);
goto still_abbrev;
}
sum_init(-1, checksum_seed);
sum_update(ptr, len);
sum_len = sum_end(sum);
if (memcmp(sum, rxas[i].datum + 1, sum_len) != 0) {
free(ptr);
goto still_abbrev;
}
if (fname == fnamecmp)
; /* Value is already set when identical */
else if (sys_lsetxattr(fname, name, ptr, len) < 0) {
rsyserr(FERROR_XFER, errno,
"rsync_xal_set: lsetxattr(%s,\"%s\") failed",
full_fname(fname), name);
ret = -1;
} else /* make sure caller sets mtime */
sxp->st.st_mtime = (time_t)-1;
if (am_generator) { /* generator items stay abbreviated */
free(ptr);
continue;
}