--- embedaddon/rsync/xattrs.c	2016/11/01 09:54:32	1.1.1.3
+++ embedaddon/rsync/xattrs.c	2021/03/17 00:32:36	1.1.1.4
@@ -3,7 +3,7 @@
  * Written by Jay Fenlason, vaguely based on the ACLs patch.
  *
  * Copyright (C) 2004 Red Hat, Inc.
- * Copyright (C) 2006-2015 Wayne Davison
+ * 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
@@ -33,18 +33,25 @@ extern int am_generator;
 extern int read_only;
 extern int list_only;
 extern int preserve_xattrs;
+extern int preserve_hfs_compression;
 extern int preserve_links;
 extern int preserve_devices;
 extern int preserve_specials;
+extern int checksum_type;
 extern int checksum_seed;
+extern int flist_csum_len;
+extern int saw_xattr_filter;
 
 #define RSYNC_XAL_INITIAL 5
 #define RSYNC_XAL_LIST_INITIAL 100
 
+#define GXD_NO_MISSING_ERROR (1<<0)
+#define GXD_OMIT_COMPRESSED (1<<1)
+#define GXD_FILE_IS_COMPRESSED (1<<2)
+
 #define MAX_FULL_DATUM 32
 
-#define HAS_PREFIX(str, prfx) (*(str) == *(prfx) \
-			    && strncmp(str, prfx, sizeof (prfx) - 1) == 0)
+#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)
 
@@ -58,7 +65,7 @@ extern int checksum_seed;
 #define SPRE_LEN ((int)sizeof SYSTEM_PREFIX - 1)
 
 #ifdef HAVE_LINUX_XATTRS
-#define MIGHT_NEED_RPRE (am_root < 0)
+#define MIGHT_NEED_RPRE (am_root <= 0)
 #define RSYNC_PREFIX USER_PREFIX "rsync."
 #else
 #define MIGHT_NEED_RPRE am_root
@@ -72,18 +79,50 @@ extern int checksum_seed;
 #define XACC_ACL_ATTR RSYNC_PREFIX "%" XACC_ACL_SUFFIX
 #define XDEF_ACL_SUFFIX "dacl"
 #define XDEF_ACL_ATTR RSYNC_PREFIX "%" XDEF_ACL_SUFFIX
+#define MD4_SUFFIX "md4"
+#define MD4_ATTR RSYNC_PREFIX "%" MD4_SUFFIX
+#define MD5_SUFFIX "md5"
+#define MD5_ATTR RSYNC_PREFIX "%" MD5_SUFFIX
 
+#define APPLE_PREFIX "com.apple."
+#define APLPRE_LEN ((int)sizeof APPLE_PREFIX - 1)
+#define DECMPFS_SUFFIX "decmpfs"
+#define RESOURCEFORK_SUFFIX "ResourceFork"
+
+#define UNREAD_DATA ((char *)1)
+
+#if MAX_DIGEST_LEN < SIZEOF_TIME_T
+#error MAX_DIGEST_LEN is too small to hold an mtime
+#endif
+
 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 item_list empty_xattr = EMPTY_ITEM_LIST;
+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;
 
@@ -128,8 +167,6 @@ static ssize_t get_xattr_names(const char *fname)
 	if (!namebuf) {
 		namebuf_len = 1024;
 		namebuf = new_array(char, namebuf_len);
-		if (!namebuf)
-			out_of_memory("get_xattr_names");
 	}
 
 	while (1) {
@@ -144,7 +181,7 @@ static ssize_t get_xattr_names(const char *fname)
 			arg = namebuf_len;
 		  got_error:
 			rsyserr(FERROR_XFER, errno,
-				"get_xattr_names: llistxattr(\"%s\",%s) failed",
+				"get_xattr_names: llistxattr(%s,%s) failed",
 				full_fname(fname), big_num(arg));
 			return -1;
 		}
@@ -157,8 +194,6 @@ static ssize_t get_xattr_names(const char *fname)
 			free(namebuf);
 		namebuf_len = list_len + 1024;
 		namebuf = new_array(char, namebuf_len);
-		if (!namebuf)
-			out_of_memory("get_xattr_names");
 	}
 
 	return list_len;
@@ -167,8 +202,7 @@ static ssize_t get_xattr_names(const char *fname)
 /* 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)
+static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr, int flags)
 {
 	size_t datum_len = sys_lgetxattr(fname, name, NULL, 0);
 	size_t extra_len = *len_ptr;
@@ -177,33 +211,41 @@ static char *get_xattr_data(const char *fname, const c
 	*len_ptr = datum_len;
 
 	if (datum_len == (size_t)-1) {
-		if (errno == ENOTSUP || no_missing_error)
+		if (errno == ENOTSUP || flags & GXD_NO_MISSING_ERROR)
 			return NULL;
 		rsyserr(FERROR_XFER, errno,
-			"get_xattr_data: lgetxattr(\"%s\",\"%s\",0) failed",
+			"get_xattr_data: lgetxattr(%s,\"%s\",0) failed",
 			full_fname(fname), name);
 		return NULL;
 	}
 
+	if (flags & GXD_OMIT_COMPRESSED && datum_len > MAX_FULL_DATUM
+	 && HAS_PREFIX(name, APPLE_PREFIX)
+	 && (strcmp(name+APLPRE_LEN, DECMPFS_SUFFIX) == 0
+	  || (flags & GXD_FILE_IS_COMPRESSED && strcmp(name+APLPRE_LEN, RESOURCEFORK_SUFFIX) == 0))) {
+		/* If we are omitting compress-file-related data, we don't want to
+		 * actually read this data. */
+		return UNREAD_DATA;
+	}
+
 	if (!datum_len && !extra_len)
 		extra_len = 1; /* request non-zero amount of memory */
-	if (datum_len + extra_len < datum_len)
+	if (SIZE_MAX - datum_len < extra_len)
 		overflow_exit("get_xattr_data");
-	if (!(ptr = new_array(char, datum_len + extra_len)))
-		out_of_memory("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);
+					"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);
+					"get_xattr_data: lgetxattr(%s,\"%s\",%ld) returned %ld\n",
+					full_fname(fname), name,
+					(long)datum_len, (long)len);
 			}
 			free(ptr);
 			return NULL;
@@ -213,8 +255,32 @@ static char *get_xattr_data(const char *fname, const c
 	return ptr;
 }
 
-static int rsync_xal_get(const char *fname, item_list *xalp)
+static void checksum_xattr_data(char *sum, const char *datum, size_t datum_len, stat_x *sxp)
 {
+	if (datum == UNREAD_DATA) {
+		/* For abbreviated compressed data, we store the file's mtime as the checksum. */
+		SIVAL(sum, 0, sxp->st.st_mtime);
+#if SIZEOF_TIME_T > 4
+		SIVAL(sum, 4, sxp->st.st_mtime >> 32);
+#if MAX_DIGEST_LEN > 8
+		memset(sum + 8, 0, MAX_DIGEST_LEN - 8);
+#endif
+#else
+#if MAX_DIGEST_LEN > 4
+		memset(sum + 4, 0, MAX_DIGEST_LEN - 4);
+#endif
+#endif
+	} else {
+		sum_init(-1, checksum_seed);
+		sum_update(datum, datum_len);
+		sum_end(sum);
+	}
+}
+
+$$$ERROR$$$ the old patch needs reworking since rsync_xal_get() has totally changed!
+
+static int rsync_xal_get(const char *fname, stat_x *sxp)
+{
 	ssize_t list_len, name_len;
 	size_t datum_len, name_offset;
 	char *name, *ptr;
@@ -222,7 +288,8 @@ static int rsync_xal_get(const char *fname, item_list 
 	int user_only = am_sender ? 0 : !am_root;
 #endif
 	rsync_xa *rxa;
-	int count;
+	int count, flags;
+	item_list *xalp = sxp->xattr;
 
 	/* This puts the name list into the "namebuf" buffer. */
 	if ((list_len = get_xattr_names(fname)) < 0)
@@ -232,40 +299,48 @@ static int rsync_xal_get(const char *fname, item_list 
 		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
-		/* We always ignore the system namespace, and non-root
-		 * ignores everything but the user namespace. */
-		if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
-			      : HAS_PREFIX(name, SYSTEM_PREFIX))
+		/* 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 (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)))
+			   || strcmp(name+RPRE_LEN+1, XDEF_ACL_SUFFIX) == 0
+			   || strcmp(name+RPRE_LEN+1, MD4_SUFFIX) == 0
+			   || strcmp(name+RPRE_LEN+1, MD5_SUFFIX) == 0)))
 				continue;
 		}
 
 		datum_len = name_len; /* Pass extra size to get_xattr_data() */
-		if (!(ptr = get_xattr_data(fname, name, &datum_len, 0)))
+		flags = GXD_OMIT_COMPRESSED;
+		if (preserve_hfs_compression && sxp->st.st_flags & UF_COMPRESSED)
+			flags |= GXD_FILE_IS_COMPRESSED;
+		if (!(ptr = get_xattr_data(fname, name, &datum_len, flags)))
 			return -1;
 
 		if (datum_len > MAX_FULL_DATUM) {
 			/* For large datums, we store a flag and a checksum. */
+			char *datum = ptr;
 			name_offset = 1 + MAX_DIGEST_LEN;
-			sum_init(checksum_seed);
+			sum_init(-1, checksum_seed);
 			sum_update(ptr, datum_len);
 			free(ptr);
 
-			if (!(ptr = new_array(char, name_offset + name_len)))
-				out_of_memory("rsync_xal_get");
+			ptr = new_array(char, name_offset + name_len);
 			*ptr = XSTATE_ABBREV;
-			sum_end(ptr + 1);
+			checksum_xattr_data(ptr+1, datum, datum_len, sxp);
+			if (datum != UNREAD_DATA)
+				free(datum);
 		} else
 			name_offset = datum_len;
 
@@ -311,7 +386,7 @@ int get_xattr(const char *fname, stat_x *sxp)
 	} else if (IS_MISSING_FILE(sxp->st))
 		return 0;
 
-	if (rsync_xal_get(fname, sxp->xattr) < 0) {
+	if (rsync_xal_get(fname, sxp) < 0) {
 		free_xattr(sxp);
 		return -1;
 	}
@@ -335,21 +410,25 @@ int copy_xattrs(const char *source, const char *dest)
 		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
-		/* We always ignore the system namespace, and non-root
-		 * ignores everything but the user namespace. */
-		if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
-			      : HAS_PREFIX(name, SYSTEM_PREFIX))
+		/* 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 (ptr == UNREAD_DATA)
+			continue; /* XXX Is this right? */
 		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",
+				"copy_xattrs: lsetxattr(%s,\"%s\") failed",
 				full_fname(dest), name);
 			errno = save_errno;
 			return -1;
@@ -360,17 +439,58 @@ int copy_xattrs(const char *source, const char *dest)
 	return 0;
 }
 
-static int find_matching_xattr(item_list *xalp)
+static int64 xattr_lookup_hash(const item_list *xalp)
 {
-	size_t i, j;
-	item_list *lst = rsync_xal_l.items;
+	const rsync_xa *rxas = xalp->items;
+	size_t i;
+	int64 key = hashlittle(&xalp->count, sizeof xalp->count);
 
-	for (i = 0; i < rsync_xal_l.count; i++) {
-		rsync_xa *rxas1 = lst[i].items;
-		rsync_xa *rxas2 = xalp->items;
+	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 (lst[i].count != xalp->count)
+		if (ptr->xa_items.count != xalp->count)
 			continue;
 		/* any elements different? */
 		for (j = 0; j < xalp->count; j++) {
@@ -391,23 +511,55 @@ static int find_matching_xattr(item_list *xalp)
 		}
 		/* no differences found.  This is The One! */
 		if (j == xalp->count)
-			return i;
+			return ref->ndx;
 	}
 
 	return -1;
+#endif
 }
 
 /* Store *xalp on the end of rsync_xal_l */
-static void rsync_xal_store(item_list *xalp)
+static int rsync_xal_store(item_list *xalp)
 {
-	item_list *new_lst = EXPAND_ITEM_LIST(&rsync_xal_l, item_list, RSYNC_XAL_LIST_INITIAL);
+	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_lst = empty_xattr;
-	(void)EXPAND_ITEM_LIST(new_lst, rsync_xa, xalp->count);
-	memcpy(new_lst->items, xalp->items, xalp->count * sizeof (rsync_xa));
-	new_lst->count = xalp->count;
+	*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. */
@@ -454,8 +606,7 @@ int send_xattr(int f, stat_x *sxp)
 			else
 				write_bigbuf(f, rxa->datum, rxa->datum_len);
 		}
-		ndx = rsync_xal_l.count; /* pre-incremented count */
-		rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
+		ndx = rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
 	}
 
 	return ndx;
@@ -466,7 +617,8 @@ int send_xattr(int f, stat_x *sxp)
  * 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)
 {
-	item_list *lst = rsync_xal_l.items;
+	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;
@@ -479,9 +631,10 @@ int xattr_diff(struct file_struct *file, stat_x *sxp, 
 		rec_cnt = 0;
 	}
 
-	if (F_XATTR(file) >= 0)
-		lst += F_XATTR(file);
-	else
+	if (F_XATTR(file) >= 0) {
+		glst += F_XATTR(file);
+		lst = &glst->xa_items;
+	} else
 		lst = &empty_xattr;
 
 	snd_rxa = lst->items;
@@ -540,11 +693,14 @@ int xattr_diff(struct file_struct *file, stat_x *sxp, 
  * XSTATE_ABBREV states into XSTATE_DONE. */
 void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
 {
-	item_list *lst = rsync_xal_l.items;
+	const rsync_xa_list *glst = rsync_xal_l.items;
+	const item_list *lst;
 	int cnt, prior_req = 0;
 	rsync_xa *rxa;
 
-	lst += F_XATTR(file);
+	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;
@@ -574,11 +730,13 @@ void send_xattr_request(const char *fname, struct file
 
 			/* 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);
+				if (errno != ENOTSUP && errno != ENOATTR)
+					rprintf(FERROR_XFER, "failed to re-read xattr %s for %s\n", rxa->name, fname);
 				write_varint(f_out, 0);
 				continue;
 			}
 
+			assert(ptr != UNREAD_DATA);
 			write_varint(f_out, len); /* length might have changed! */
 			write_bigbuf(f_out, ptr, len);
 			free(ptr);
@@ -595,7 +753,8 @@ void send_xattr_request(const char *fname, struct file
  * stores it in place of its checksum. */
 int recv_xattr_request(struct file_struct *file, int f_in)
 {
-	item_list *lst = rsync_xal_l.items;
+	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;
@@ -604,17 +763,40 @@ int recv_xattr_request(struct file_struct *file, int f
 		rprintf(FERROR, "recv_xattr_request: internal data error!\n");
 		exit_cleanup(RERR_PROTOCOL);
 	}
-	lst += F_XATTR(file);
+	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;
-		/* Note that the sender-related num values may not be in order on the receiver! */
-		while (cnt && (am_sender ? rxa->num < num : rxa->num != num)) {
-			rxa++;
-			cnt--;
+		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",
@@ -635,11 +817,9 @@ int recv_xattr_request(struct file_struct *file, int f
 		old_datum = rxa->datum;
 		rxa->datum_len = read_varint(f_in);
 
-		if (rxa->name_len + rxa->datum_len < rxa->name_len)
+		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);
-		if (!rxa->datum)
-			out_of_memory("recv_xattr_request");
 		name = rxa->datum + rxa->datum_len;
 		memcpy(name, rxa->name, rxa->name_len);
 		rxa->name = name;
@@ -688,24 +868,32 @@ void receive_xattr(int f, struct file_struct *file)
 		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 ((dget_len + extra_len < dget_len)
-		 || (dget_len + extra_len + name_len < dget_len))
+		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);
-		if (!ptr)
-			out_of_memory("receive_xattr");
 		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) {
+			if (!am_root && !saw_xattr_filter) {
 				free(ptr);
 				continue;
 			}
@@ -736,6 +924,7 @@ void receive_xattr(int f, struct file_struct *file)
 			free(ptr);
 			continue;
 		}
+
 		rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, 1);
 		rxa->name = name;
 		rxa->datum = ptr;
@@ -747,8 +936,7 @@ void receive_xattr(int f, struct file_struct *file)
 	if (need_sort && count > 1)
 		qsort(temp_xattr.items, count, sizeof (rsync_xa), rsync_xal_compare_names);
 
-	ndx = rsync_xal_l.count; /* pre-incremented count */
-	rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
+	ndx = rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
 
 	F_XATTR(file) = ndx;
 }
@@ -774,12 +962,46 @@ void cache_tmp_xattr(struct file_struct *file, stat_x 
 void uncache_tmp_xattrs(void)
 {
 	if (prior_xattr_count != (size_t)-1) {
-		item_list *xattr_item = rsync_xal_l.items;
-		item_list *xattr_start = xattr_item + prior_xattr_count;
-		xattr_item += rsync_xal_l.count;
+		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 (xattr_item-- > xattr_start)
-			rsync_xal_free(xattr_item);
+		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;
 	}
 }
@@ -795,7 +1017,7 @@ static int rsync_xal_set(const char *fname, item_list 
 	int user_only = am_root <= 0;
 #endif
 	size_t name_len;
-	int ret = 0;
+	int flags, ret = 0;
 
 	/* This puts the current name list into the "namebuf" buffer. */
 	if ((list_len = get_xattr_names(fname)) < 0)
@@ -805,9 +1027,13 @@ static int rsync_xal_set(const char *fname, item_list 
 		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) {
+			flags = GXD_OMIT_COMPRESSED | GXD_NO_MISSING_ERROR;
+			if (preserve_hfs_compression && sxp->st.st_flags & UF_COMPRESSED)
+				flags |= GXD_FILE_IS_COMPRESSED;
+			if ((ptr = get_xattr_data(fnamecmp, name, &len, flags)) == NULL) {
 			  still_abbrev:
 				if (am_generator)
 					continue;
@@ -816,15 +1042,17 @@ static int rsync_xal_set(const char *fname, item_list 
 				ret = -1;
 				continue;
 			}
+			if (ptr == UNREAD_DATA)
+				continue; /* XXX Is this right? */
 			if (len != rxas[i].datum_len) {
 				free(ptr);
 				goto still_abbrev;
 			}
 
-			sum_init(checksum_seed);
+			sum_init(-1, checksum_seed);
 			sum_update(ptr, len);
-			sum_end(sum);
-			if (memcmp(sum, rxas[i].datum + 1, MAX_DIGEST_LEN) != 0) {
+			sum_len = sum_end(sum);
+			if (memcmp(sum, rxas[i].datum + 1, sum_len) != 0) {
 				free(ptr);
 				goto still_abbrev;
 			}
@@ -833,7 +1061,7 @@ static int rsync_xal_set(const char *fname, item_list 
 				; /* 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",
+					"rsync_xal_set: lsetxattr(%s,\"%s\") failed",
 					full_fname(fname), name);
 				ret = -1;
 			} else /* make sure caller sets mtime */
@@ -854,7 +1082,7 @@ static int rsync_xal_set(const char *fname, item_list 
 
 		if (sys_lsetxattr(fname, name, rxas[i].datum, rxas[i].datum_len) < 0) {
 			rsyserr(FERROR_XFER, errno,
-				"rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
+				"rsync_xal_set: lsetxattr(%s,\"%s\") failed",
 				full_fname(fname), name);
 			ret = -1;
 		} else /* make sure caller sets mtime */
@@ -866,15 +1094,16 @@ static int rsync_xal_set(const char *fname, item_list 
 		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
-		/* We always ignore the system namespace, and non-root
-		 * ignores everything but the user namespace. */
-		if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
-			      : HAS_PREFIX(name, SYSTEM_PREFIX))
+		/* 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
-		if (am_root < 0 && name_len > RPRE_LEN
-		 && name[RPRE_LEN] == '%' && strcmp(name, XSTAT_ATTR) == 0)
+		if (am_root < 0 && name_len > RPRE_LEN && name[RPRE_LEN] == '%' && strcmp(name, XSTAT_ATTR) == 0)
 			continue;
 
 		for (i = 0; i < xalp->count; i++) {
@@ -884,7 +1113,7 @@ static int rsync_xal_set(const char *fname, item_list 
 		if (i == xalp->count) {
 			if (sys_lremovexattr(fname, name) < 0) {
 				rsyserr(FERROR_XFER, errno,
-					"rsync_xal_set: lremovexattr(\"%s\",\"%s\") failed",
+					"rsync_xal_set: lremovexattr(%s,\"%s\") failed",
 					full_fname(fname), name);
 				ret = -1;
 			} else /* make sure caller sets mtime */
@@ -892,15 +1121,19 @@ static int rsync_xal_set(const char *fname, item_list 
 		}
 	}
 
+#ifdef HAVE_OSX_XATTRS
+	rsync_xal_free(xalp); /* Free this because we aren't using find_matching_xattr(). */
+#endif
+
 	return ret;
 }
 
 /* Set extended attributes on indicated filename. */
-int set_xattr(const char *fname, const struct file_struct *file,
-	      const char *fnamecmp, stat_x *sxp)
+int set_xattr(const char *fname, const struct file_struct *file, const char *fnamecmp, stat_x *sxp)
 {
+	rsync_xa_list *glst = rsync_xal_l.items;
+	item_list *lst;
 	int ndx;
-	item_list *lst = rsync_xal_l.items;
 
 	if (dry_run)
 		return 1; /* FIXME: --dry-run needs to compute this value */
@@ -930,7 +1163,9 @@ int set_xattr(const char *fname, const struct file_str
 #endif
 
 	ndx = F_XATTR(file);
-	return rsync_xal_set(fname, lst + ndx, fnamecmp, sxp);
+	glst += ndx;
+	lst = &glst->xa_items;
+	return rsync_xal_set(fname, lst, fnamecmp, sxp);
 }
 
 #ifdef SUPPORT_ACLS
@@ -938,7 +1173,7 @@ char *get_xattr_acl(const char *fname, int is_access_a
 {
 	const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
 	*len_p = 0; /* no extra data alloc needed from get_xattr_data() */
-	return get_xattr_data(fname, name, len_p, 1);
+	return get_xattr_data(fname, name, len_p, GXD_NO_MISSING_ERROR);
 }
 
 int set_xattr_acl(const char *fname, int is_access_acl, const char *buf, size_t buf_len)
@@ -946,7 +1181,7 @@ int set_xattr_acl(const char *fname, int is_access_acl
 	const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
 	if (sys_lsetxattr(fname, name, buf, buf_len) < 0) {
 		rsyserr(FERROR_XFER, errno,
-			"set_xattr_acl: lsetxattr(\"%s\",\"%s\") failed",
+			"set_xattr_acl: lsetxattr(%s,\"%s\") failed",
 			full_fname(fname), name);
 		return -1;
 	}
@@ -959,6 +1194,38 @@ int del_def_xattr_acl(const char *fname)
 }
 #endif
 
+int get_sum_xattr(const char *fname, STRUCT_STAT *stp, char *sum)
+{
+	const char *mdattr = checksum_type == 5 ? MD5_ATTR : MD4_ATTR;
+	char buf[256];
+	uint32 file_length, mtime;
+	int len;
+
+	len = sys_lgetxattr(fname, mdattr, buf, sizeof buf);
+	if (len < 0) {
+		if (errno == ENOTSUP || errno == ENOATTR)
+			return 0;
+		rsyserr(FERROR_XFER, errno, "failed to read xattr %s for %s",
+			mdattr, full_fname(fname));
+		return 0;
+	}
+	if (len != 4 + 4 + flist_csum_len) {
+		rprintf(FERROR, "Corrupt %s xattr attached to %s -- skipping\n",
+			mdattr, full_fname(fname));
+		return 0;
+	}
+
+	file_length = IVAL(buf, 0); /* 32-bit values -- trunctions are OK */
+	mtime = IVAL(buf, 4);
+
+	if ((uint32)stp->st_size != file_length || (uint32)stp->st_mtime != mtime)
+		return 0;
+
+	memcpy(sum, buf + 8, flist_csum_len);
+
+	return 1;
+}
+
 int get_stat_xattr(const char *fname, int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
 {
 	int mode, rdev_major, rdev_minor, uid, gid, len;
@@ -1045,7 +1312,7 @@ int set_stat_xattr(const char *fname, struct file_stru
 	mode = (fst.st_mode & _S_IFMT) | (fmode & ACCESSPERMS)
 	     | (S_ISDIR(fst.st_mode) ? 0700 : 0600);
 	if (fst.st_mode != mode)
-		do_chmod(fname, mode);
+		do_chmod(fname, mode, ST_FLAGS(fst));
 	if (!IS_DEVICE(fst.st_mode))
 		fst.st_rdev = 0; /* just in case */
 
@@ -1081,11 +1348,33 @@ int set_stat_xattr(const char *fname, struct file_stru
 	return 0;
 }
 
+#ifdef SUPPORT_HFS_COMPRESSION
+static inline void hfs_compress_tweaks(STRUCT_STAT *fst)
+{
+	if (fst->st_flags & UF_COMPRESSED) {
+		if (preserve_hfs_compression) {
+			/* We're sending the compression xattr, not the decompressed data fork.
+			 * Setting rsync's idea of the file size to 0 effectively prevents the
+			 * transfer of the data fork. */
+			fst->st_size = 0;
+		} else {
+			/* If the sender's filesystem supports compression, then we'll be able
+			 * to send the decompressed data fork and the decmpfs xattr will be
+			 * hidden (not sent). As such, we need to strip the compression flag. */
+			fst->st_flags &= ~UF_COMPRESSED;
+		}
+	}
+}
+#endif
+
 int x_stat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
 {
 	int ret = do_stat(fname, fst);
 	if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
 		xst->st_mode = 0;
+#ifdef SUPPORT_HFS_COMPRESSION
+	hfs_compress_tweaks(fst);
+#endif
 	return ret;
 }
 
@@ -1094,6 +1383,9 @@ int x_lstat(const char *fname, STRUCT_STAT *fst, STRUC
 	int ret = do_lstat(fname, fst);
 	if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
 		xst->st_mode = 0;
+#ifdef SUPPORT_HFS_COMPRESSION
+	hfs_compress_tweaks(fst);
+#endif
 	return ret;
 }
 
@@ -1102,6 +1394,9 @@ int x_fstat(int fd, STRUCT_STAT *fst, STRUCT_STAT *xst
 	int ret = do_fstat(fd, fst);
 	if ((ret < 0 || get_stat_xattr(NULL, fd, fst, xst) < 0) && xst)
 		xst->st_mode = 0;
+#ifdef SUPPORT_HFS_COMPRESSION
+	hfs_compress_tweaks(fst);
+#endif
 	return ret;
 }