Adding upstream version 3.2.7.upstream/3.2.7

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1113 insertions, 0 deletions

diff --git a/token.c b/token.c
new file mode 100644
index 0000000..c108b3a
--- /dev/null
+++ b/token.c
@@ -0,0 +1,1113 @@
+/*
+ * Routines used by the file-transfer code.
+ *
+ * Copyright (C) 1996 Andrew Tridgell
+ * Copyright (C) 1996 Paul Mackerras
+ * Copyright (C) 2003-2022 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 "itypes.h"
+#include <zlib.h>
+#ifdef SUPPORT_ZSTD
+#include <zstd.h>
+#endif
+#ifdef SUPPORT_LZ4
+#include <lz4.h>
+#endif
+
+extern int do_compression;
+extern int protocol_version;
+extern int module_id;
+extern int do_compression_level;
+extern char *skip_compress;
+
+#ifndef Z_INSERT_ONLY
+#define Z_INSERT_ONLY Z_SYNC_FLUSH
+#endif
+
+static int skip_compression_level; /* The least possible compressing for handling skip-compress files. */
+static int per_file_default_level; /* The default level that each new file gets prior to checking its suffix. */
+
+struct suffix_tree {
+	struct suffix_tree *sibling;
+	struct suffix_tree *child;
+	char letter, word_end;
+};
+
+static char *match_list;
+static struct suffix_tree *suftree;
+
+void init_compression_level(void)
+{
+	int min_level, max_level, def_level, off_level;
+
+	switch (do_compression) {
+	case CPRES_NONE:
+		return;
+	case CPRES_ZLIB:
+	case CPRES_ZLIBX:
+		min_level = 1;
+		max_level = Z_BEST_COMPRESSION;
+		def_level = 6; /* Z_DEFAULT_COMPRESSION is -1, so set it to the real default */
+		off_level = skip_compression_level = Z_NO_COMPRESSION;
+		if (do_compression_level == Z_DEFAULT_COMPRESSION)
+			do_compression_level = def_level;
+		break;
+#ifdef SUPPORT_ZSTD
+	case CPRES_ZSTD:
+		min_level = skip_compression_level = ZSTD_minCLevel();
+		max_level = ZSTD_maxCLevel();
+		def_level = ZSTD_CLEVEL_DEFAULT;
+		off_level = CLVL_NOT_SPECIFIED;
+		if (do_compression_level == 0)
+			do_compression_level = def_level;
+		break;
+#endif
+#ifdef SUPPORT_LZ4
+	case CPRES_LZ4:
+		min_level = skip_compression_level = 0;
+		max_level = 0;
+		def_level = 0;
+		off_level = CLVL_NOT_SPECIFIED;
+		break;
+#endif
+	default: /* paranoia to prevent missing case values */
+		NOISY_DEATH("Unknown do_compression value");
+	}
+
+	if (do_compression_level == CLVL_NOT_SPECIFIED)
+		do_compression_level = def_level;
+	else if (do_compression_level == off_level) {
+		do_compression = CPRES_NONE;
+		return;
+	}
+
+	/* We don't bother with any errors or warnings -- just make sure that the values are valid. */
+	if (do_compression_level < min_level)
+		do_compression_level = min_level;
+	else if (do_compression_level > max_level)
+		do_compression_level = max_level;
+}
+
+static void add_suffix(struct suffix_tree **prior, char ltr, const char *str)
+{
+	struct suffix_tree *node, *newnode;
+
+	if (ltr == '[') {
+		const char *after = strchr(str, ']');
+		/* Treat "[foo" and "[]" as having a literal '['. */
+		if (after && after++ != str+1) {
+			while ((ltr = *str++) != ']')
+				add_suffix(prior, ltr, after);
+			return;
+		}
+	}
+
+	for (node = *prior; node; prior = &node->sibling, node = node->sibling) {
+		if (node->letter == ltr) {
+			if (*str)
+				add_suffix(&node->child, *str, str+1);
+			else
+				node->word_end = 1;
+			return;
+		}
+		if (node->letter > ltr)
+			break;
+	}
+	newnode = new(struct suffix_tree);
+	newnode->sibling = node;
+	newnode->child = NULL;
+	newnode->letter = ltr;
+	*prior = newnode;
+	if (*str) {
+		add_suffix(&newnode->child, *str, str+1);
+		newnode->word_end = 0;
+	} else
+		newnode->word_end = 1;
+}
+
+static void add_nocompress_suffixes(const char *str)
+{
+	char *buf, *t;
+	const char *f = str;
+
+	buf = new_array(char, strlen(f) + 1);
+
+	while (*f) {
+		if (*f == '/') {
+			f++;
+			continue;
+		}
+
+		t = buf;
+		do {
+			if (isUpper(f))
+				*t++ = toLower(f);
+			else
+				*t++ = *f;
+		} while (*++f != '/' && *f);
+		*t++ = '\0';
+
+		add_suffix(&suftree, *buf, buf+1);
+	}
+
+	free(buf);
+}
+
+static void init_set_compression(void)
+{
+	const char *f;
+	char *t, *start;
+
+	if (skip_compress)
+		add_nocompress_suffixes(skip_compress);
+
+	/* A non-daemon transfer skips the default suffix list if the
+	 * user specified --skip-compress. */
+	if (skip_compress && module_id < 0)
+		f = "";
+	else
+		f = lp_dont_compress(module_id);
+
+	match_list = t = new_array(char, strlen(f) + 2);
+
+	per_file_default_level = do_compression_level;
+
+	while (*f) {
+		if (*f == ' ') {
+			f++;
+			continue;
+		}
+
+		start = t;
+		do {
+			if (isUpper(f))
+				*t++ = toLower(f);
+			else
+				*t++ = *f;
+		} while (*++f != ' ' && *f);
+		*t++ = '\0';
+
+		if (t - start == 1+1 && *start == '*') {
+			/* Optimize a match-string of "*". */
+			*match_list = '\0';
+			suftree = NULL;
+			per_file_default_level = skip_compression_level;
+			break;
+		}
+
+		/* Move *.foo items into the stuffix tree. */
+		if (*start == '*' && start[1] == '.' && start[2]
+		 && !strpbrk(start+2, ".?*")) {
+			add_suffix(&suftree, start[2], start+3);
+			t = start;
+		}
+	}
+	*t++ = '\0';
+}
+
+/* determine the compression level based on a wildcard filename list */
+void set_compression(const char *fname)
+{
+#if 0 /* No compression algorithms currently allow mid-stream changing of the level. */
+	const struct suffix_tree *node;
+	const char *s;
+	char ltr;
+#endif
+
+	if (!do_compression)
+		return;
+
+	if (!match_list)
+		init_set_compression();
+
+#if 0
+	compression_level = per_file_default_level;
+
+	if (!*match_list && !suftree)
+		return;
+
+	if ((s = strrchr(fname, '/')) != NULL)
+		fname = s + 1;
+
+	for (s = match_list; *s; s += strlen(s) + 1) {
+		if (iwildmatch(s, fname)) {
+			compression_level = skip_compression_level;
+			return;
+		}
+	}
+
+	if (!(node = suftree) || !(s = strrchr(fname, '.'))
+	 || s == fname || !(ltr = *++s))
+		return;
+
+	while (1) {
+		if (isUpper(&ltr))
+			ltr = toLower(&ltr);
+		while (node->letter != ltr) {
+			if (node->letter > ltr)
+				return;
+			if (!(node = node->sibling))
+				return;
+		}
+		if ((ltr = *++s) == '\0') {
+			if (node->word_end)
+				compression_level = skip_compression_level;
+			return;
+		}
+		if (!(node = node->child))
+			return;
+	}
+#else
+	(void)fname;
+#endif
+}
+
+/* non-compressing recv token */
+static int32 simple_recv_token(int f, char **data)
+{
+	static int32 residue;
+	static char *buf;
+	int32 n;
+
+	if (!buf)
+		buf = new_array(char, CHUNK_SIZE);
+
+	if (residue == 0) {
+		int32 i = read_int(f);
+		if (i <= 0)
+			return i;
+		residue = i;
+	}
+
+	*data = buf;
+	n = MIN(CHUNK_SIZE,residue);
+	residue -= n;
+	read_buf(f,buf,n);
+	return n;
+}
+
+/* non-compressing send token */
+static void simple_send_token(int f, int32 token, struct map_struct *buf, OFF_T offset, int32 n)
+{
+	if (n > 0) {
+		int32 len = 0;
+		while (len < n) {
+			int32 n1 = MIN(CHUNK_SIZE, n-len);
+			write_int(f, n1);
+			write_buf(f, map_ptr(buf, offset+len, n1), n1);
+			len += n1;
+		}
+	}
+	/* a -2 token means to send data only and no token */
+	if (token != -2)
+		write_int(f, -(token+1));
+}
+
+/* Flag bytes in compressed stream are encoded as follows: */
+#define END_FLAG	0	/* that's all folks */
+#define TOKEN_LONG	0x20	/* followed by 32-bit token number */
+#define TOKENRUN_LONG	0x21	/* ditto with 16-bit run count */
+#define DEFLATED_DATA	0x40	/* + 6-bit high len, then low len byte */
+#define TOKEN_REL	0x80	/* + 6-bit relative token number */
+#define TOKENRUN_REL	0xc0	/* ditto with 16-bit run count */
+
+#define MAX_DATA_COUNT	16383	/* fit 14 bit count into 2 bytes with flags */
+
+/* zlib.h says that if we want to be able to compress something in a single
+ * call, avail_out must be at least 0.1% larger than avail_in plus 12 bytes.
+ * We'll add in 0.1%+16, just to be safe (and we'll avoid floating point,
+ * to ensure that this is a compile-time value). */
+#define AVAIL_OUT_SIZE(avail_in_size) ((avail_in_size)*1001/1000+16)
+
+/* For coding runs of tokens */
+static int32 last_token = -1;
+static int32 run_start;
+static int32 last_run_end;
+
+/* Deflation state */
+static z_stream tx_strm;
+
+/* Output buffer */
+static char *obuf;
+
+/* We want obuf to be able to hold both MAX_DATA_COUNT+2 bytes as well as
+ * AVAIL_OUT_SIZE(CHUNK_SIZE) bytes, so make sure that it's large enough. */
+#if MAX_DATA_COUNT+2 > AVAIL_OUT_SIZE(CHUNK_SIZE)
+#define OBUF_SIZE	(MAX_DATA_COUNT+2)
+#else
+#define OBUF_SIZE	AVAIL_OUT_SIZE(CHUNK_SIZE)
+#endif
+
+/* Send a deflated token */
+static void
+send_deflated_token(int f, int32 token, struct map_struct *buf, OFF_T offset, int32 nb, int32 toklen)
+{
+	static int init_done, flush_pending;
+	int32 n, r;
+
+	if (last_token == -1) {
+		/* initialization */
+		if (!init_done) {
+			tx_strm.next_in = NULL;
+			tx_strm.zalloc = NULL;
+			tx_strm.zfree = NULL;
+			if (deflateInit2(&tx_strm, per_file_default_level,
+					 Z_DEFLATED, -15, 8,
+					 Z_DEFAULT_STRATEGY) != Z_OK) {
+				rprintf(FERROR, "compression init failed\n");
+				exit_cleanup(RERR_PROTOCOL);
+			}
+			obuf = new_array(char, OBUF_SIZE);
+			init_done = 1;
+		} else
+			deflateReset(&tx_strm);
+		last_run_end = 0;
+		run_start = token;
+		flush_pending = 0;
+	} else if (last_token == -2) {
+		run_start = token;
+	} else if (nb != 0 || token != last_token + 1 || token >= run_start + 65536) {
+		/* output previous run */
+		r = run_start - last_run_end;
+		n = last_token - run_start;
+		if (r >= 0 && r <= 63) {
+			write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
+		} else {
+			write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
+			write_int(f, run_start);
+		}
+		if (n != 0) {
+			write_byte(f, n);
+			write_byte(f, n >> 8);
+		}
+		last_run_end = last_token;
+		run_start = token;
+	}
+
+	last_token = token;
+
+	if (nb != 0 || flush_pending) {
+		/* deflate the data starting at offset */
+		int flush = Z_NO_FLUSH;
+		tx_strm.avail_in = 0;
+		tx_strm.avail_out = 0;
+		do {
+			if (tx_strm.avail_in == 0 && nb != 0) {
+				/* give it some more input */
+				n = MIN(nb, CHUNK_SIZE);
+				tx_strm.next_in = (Bytef *)
+					map_ptr(buf, offset, n);
+				tx_strm.avail_in = n;
+				nb -= n;
+				offset += n;
+			}
+			if (tx_strm.avail_out == 0) {
+				tx_strm.next_out = (Bytef *)(obuf + 2);
+				tx_strm.avail_out = MAX_DATA_COUNT;
+				if (flush != Z_NO_FLUSH) {
+					/*
+					 * We left the last 4 bytes in the
+					 * buffer, in case they are the
+					 * last 4.  Move them to the front.
+					 */
+					memcpy(tx_strm.next_out, obuf+MAX_DATA_COUNT-2, 4);
+					tx_strm.next_out += 4;
+					tx_strm.avail_out -= 4;
+				}
+			}
+			if (nb == 0 && token != -2)
+				flush = Z_SYNC_FLUSH;
+			r = deflate(&tx_strm, flush);
+			if (r != Z_OK) {
+				rprintf(FERROR, "deflate returned %d\n", r);
+				exit_cleanup(RERR_STREAMIO);
+			}
+			if (nb == 0 || tx_strm.avail_out == 0) {
+				n = MAX_DATA_COUNT - tx_strm.avail_out;
+				if (flush != Z_NO_FLUSH) {
+					/*
+					 * We have to trim off the last 4
+					 * bytes of output when flushing
+					 * (they are just 0, 0, ff, ff).
+					 */
+					n -= 4;
+				}
+				if (n > 0) {
+					obuf[0] = DEFLATED_DATA + (n >> 8);
+					obuf[1] = n;
+					write_buf(f, obuf, n+2);
+				}
+			}
+		} while (nb != 0 || tx_strm.avail_out == 0);
+		flush_pending = token == -2;
+	}
+
+	if (token == -1) {
+		/* end of file - clean up */
+		write_byte(f, END_FLAG);
+	} else if (token != -2 && do_compression == CPRES_ZLIB) {
+		/* Add the data in the current block to the compressor's
+		 * history and hash table. */
+		do {
+			/* Break up long sections in the same way that
+			 * see_deflate_token() does. */
+			int32 n1 = toklen > 0xffff ? 0xffff : toklen;
+			toklen -= n1;
+			tx_strm.next_in = (Bytef *)map_ptr(buf, offset, n1);
+			tx_strm.avail_in = n1;
+			if (protocol_version >= 31) /* Newer protocols avoid a data-duplicating bug */
+				offset += n1;
+			tx_strm.next_out = (Bytef *) obuf;
+			tx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
+			r = deflate(&tx_strm, Z_INSERT_ONLY);
+			if (r != Z_OK || tx_strm.avail_in != 0) {
+				rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
+					r, tx_strm.avail_in);
+				exit_cleanup(RERR_STREAMIO);
+			}
+		} while (toklen > 0);
+	}
+}
+
+/* tells us what the receiver is in the middle of doing */
+static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
+
+/* for inflating stuff */
+static z_stream rx_strm;
+static char *cbuf;
+static char *dbuf;
+
+/* for decoding runs of tokens */
+static int32 rx_token;
+static int32 rx_run;
+
+/* Receive a deflated token and inflate it */
+static int32 recv_deflated_token(int f, char **data)
+{
+	static int init_done;
+	static int32 saved_flag;
+	int32 n, flag;
+	int r;
+
+	for (;;) {
+		switch (recv_state) {
+		case r_init:
+			if (!init_done) {
+				rx_strm.next_out = NULL;
+				rx_strm.zalloc = NULL;
+				rx_strm.zfree = NULL;
+				if (inflateInit2(&rx_strm, -15) != Z_OK) {
+					rprintf(FERROR, "inflate init failed\n");
+					exit_cleanup(RERR_PROTOCOL);
+				}
+				cbuf = new_array(char, MAX_DATA_COUNT);
+				dbuf = new_array(char, AVAIL_OUT_SIZE(CHUNK_SIZE));
+				init_done = 1;
+			} else {
+				inflateReset(&rx_strm);
+			}
+			recv_state = r_idle;
+			rx_token = 0;
+			break;
+
+		case r_idle:
+		case r_inflated:
+			if (saved_flag) {
+				flag = saved_flag & 0xff;
+				saved_flag = 0;
+			} else
+				flag = read_byte(f);
+			if ((flag & 0xC0) == DEFLATED_DATA) {
+				n = ((flag & 0x3f) << 8) + read_byte(f);
+				read_buf(f, cbuf, n);
+				rx_strm.next_in = (Bytef *)cbuf;
+				rx_strm.avail_in = n;
+				recv_state = r_inflating;
+				break;
+			}
+			if (recv_state == r_inflated) {
+				/* check previous inflated stuff ended correctly */
+				rx_strm.avail_in = 0;
+				rx_strm.next_out = (Bytef *)dbuf;
+				rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
+				r = inflate(&rx_strm, Z_SYNC_FLUSH);
+				n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
+				/*
+				 * Z_BUF_ERROR just means no progress was
+				 * made, i.e. the decompressor didn't have
+				 * any pending output for us.
+				 */
+				if (r != Z_OK && r != Z_BUF_ERROR) {
+					rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
+						r, n);
+					exit_cleanup(RERR_STREAMIO);
+				}
+				if (n != 0 && r != Z_BUF_ERROR) {
+					/* have to return some more data and
+					   save the flag for later. */
+					saved_flag = flag + 0x10000;
+					*data = dbuf;
+					return n;
+				}
+				/*
+				 * At this point the decompressor should
+				 * be expecting to see the 0, 0, ff, ff bytes.
+				 */
+				if (!inflateSyncPoint(&rx_strm)) {
+					rprintf(FERROR, "decompressor lost sync!\n");
+					exit_cleanup(RERR_STREAMIO);
+				}
+				rx_strm.avail_in = 4;
+				rx_strm.next_in = (Bytef *)cbuf;
+				cbuf[0] = cbuf[1] = 0;
+				cbuf[2] = cbuf[3] = (char)0xff;
+				inflate(&rx_strm, Z_SYNC_FLUSH);
+				recv_state = r_idle;
+			}
+			if (flag == END_FLAG) {
+				/* that's all folks */
+				recv_state = r_init;
+				return 0;
+			}
+
+			/* here we have a token of some kind */
+			if (flag & TOKEN_REL) {
+				rx_token += flag & 0x3f;
+				flag >>= 6;
+			} else
+				rx_token = read_int(f);
+			if (flag & 1) {
+				rx_run = read_byte(f);
+				rx_run += read_byte(f) << 8;
+				recv_state = r_running;
+			}
+			return -1 - rx_token;
+
+		case r_inflating:
+			rx_strm.next_out = (Bytef *)dbuf;
+			rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
+			r = inflate(&rx_strm, Z_NO_FLUSH);
+			n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
+			if (r != Z_OK) {
+				rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
+				exit_cleanup(RERR_STREAMIO);
+			}
+			if (rx_strm.avail_in == 0)
+				recv_state = r_inflated;
+			if (n != 0) {
+				*data = dbuf;
+				return n;
+			}
+			break;
+
+		case r_running:
+			++rx_token;
+			if (--rx_run == 0)
+				recv_state = r_idle;
+			return -1 - rx_token;
+		}
+	}
+}
+
+/*
+ * put the data corresponding to a token that we've just returned
+ * from recv_deflated_token into the decompressor's history buffer.
+ */
+static void see_deflate_token(char *buf, int32 len)
+{
+	int r;
+	int32 blklen;
+	unsigned char hdr[5];
+
+	rx_strm.avail_in = 0;
+	blklen = 0;
+	hdr[0] = 0;
+	do {
+		if (rx_strm.avail_in == 0 && len != 0) {
+			if (blklen == 0) {
+				/* Give it a fake stored-block header. */
+				rx_strm.next_in = (Bytef *)hdr;
+				rx_strm.avail_in = 5;
+				blklen = len;
+				if (blklen > 0xffff)
+					blklen = 0xffff;
+				hdr[1] = blklen;
+				hdr[2] = blklen >> 8;
+				hdr[3] = ~hdr[1];
+				hdr[4] = ~hdr[2];
+			} else {
+				rx_strm.next_in = (Bytef *)buf;
+				rx_strm.avail_in = blklen;
+				if (protocol_version >= 31) /* Newer protocols avoid a data-duplicating bug */
+					buf += blklen;
+				len -= blklen;
+				blklen = 0;
+			}
+		}
+		rx_strm.next_out = (Bytef *)dbuf;
+		rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
+		r = inflate(&rx_strm, Z_SYNC_FLUSH);
+		if (r != Z_OK && r != Z_BUF_ERROR) {
+			rprintf(FERROR, "inflate (token) returned %d\n", r);
+			exit_cleanup(RERR_STREAMIO);
+		}
+	} while (len || rx_strm.avail_out == 0);
+}
+
+#ifdef SUPPORT_ZSTD
+
+static ZSTD_inBuffer zstd_in_buff;
+static ZSTD_outBuffer zstd_out_buff;
+static ZSTD_CCtx *zstd_cctx;
+
+static void send_zstd_token(int f, int32 token, struct map_struct *buf, OFF_T offset, int32 nb)
+{
+	static int comp_init_done, flush_pending;
+	ZSTD_EndDirective flush = ZSTD_e_continue;
+	int32 n, r;
+
+	/* initialization */
+	if (!comp_init_done) {
+		zstd_cctx = ZSTD_createCCtx();
+		if (!zstd_cctx) {
+			rprintf(FERROR, "compression init failed\n");
+			exit_cleanup(RERR_PROTOCOL);
+		}
+
+		obuf = new_array(char, OBUF_SIZE);
+
+		ZSTD_CCtx_setParameter(zstd_cctx, ZSTD_c_compressionLevel, do_compression_level);
+		zstd_out_buff.dst = obuf + 2;
+
+		comp_init_done = 1;
+	}
+
+	if (last_token == -1) {
+		last_run_end = 0;
+		run_start = token;
+		flush_pending = 0;
+	} else if (last_token == -2) {
+		run_start = token;
+	} else if (nb != 0 || token != last_token + 1 || token >= run_start + 65536) {
+		/* output previous run */
+		r = run_start - last_run_end;
+		n = last_token - run_start;
+
+		if (r >= 0 && r <= 63) {
+			write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
+		} else {
+			write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
+			write_int(f, run_start);
+		}
+		if (n != 0) {
+			write_byte(f, n);
+			write_byte(f, n >> 8);
+		}
+		last_run_end = last_token;
+		run_start = token;
+	}
+
+	last_token = token;
+
+	if (nb || flush_pending) {
+
+		zstd_in_buff.src = map_ptr(buf, offset, nb);
+		zstd_in_buff.size = nb;
+		zstd_in_buff.pos = 0;
+
+		do {
+			if (zstd_out_buff.size == 0) {
+				zstd_out_buff.size = MAX_DATA_COUNT;
+				zstd_out_buff.pos = 0;
+			}
+
+			/* File ended, flush */
+			if (token != -2)
+				flush = ZSTD_e_flush;
+
+			r = ZSTD_compressStream2(zstd_cctx, &zstd_out_buff, &zstd_in_buff, flush);
+			if (ZSTD_isError(r)) {
+				rprintf(FERROR, "ZSTD_compressStream returned %d\n", r);
+				exit_cleanup(RERR_STREAMIO);
+			}
+
+			/*
+			 * Nothing is sent if the buffer isn't full so avoid smaller
+			 * transfers. If a file is finished then we flush the internal
+			 * state and send a smaller buffer so that the remote side can
+			 * finish the file.
+			 */
+			if (zstd_out_buff.pos == zstd_out_buff.size || flush == ZSTD_e_flush) {
+				n = zstd_out_buff.pos;
+
+				obuf[0] = DEFLATED_DATA + (n >> 8);
+				obuf[1] = n;
+				write_buf(f, obuf, n+2);
+
+				zstd_out_buff.size = 0;
+			}
+			/*
+			 * Loop while the input buffer isn't full consumed or the
+			 * internal state isn't fully flushed.
+			 */
+		} while (zstd_in_buff.pos < zstd_in_buff.size || r > 0);
+		flush_pending = token == -2;
+	}
+
+	if (token == -1) {
+		/* end of file - clean up */
+		write_byte(f, END_FLAG);
+	}
+}
+
+static ZSTD_DCtx *zstd_dctx;
+
+static int32 recv_zstd_token(int f, char **data)
+{
+	static int decomp_init_done;
+	static int out_buffer_size;
+	int32 n, flag;
+	int r;
+
+	if (!decomp_init_done) {
+		zstd_dctx = ZSTD_createDCtx();
+		if (!zstd_dctx) {
+			rprintf(FERROR, "ZSTD_createDStream failed\n");
+			exit_cleanup(RERR_PROTOCOL);
+		}
+
+		/* Output buffer fits two decompressed blocks */
+		out_buffer_size = ZSTD_DStreamOutSize() * 2;
+		cbuf = new_array(char, MAX_DATA_COUNT);
+		dbuf = new_array(char, out_buffer_size);
+
+		zstd_in_buff.src = cbuf;
+		zstd_out_buff.dst = dbuf;
+
+		decomp_init_done = 1;
+	}
+
+	for (;;) {
+		switch (recv_state) {
+		case r_init:
+			recv_state = r_idle;
+			rx_token = 0;
+			break;
+
+		case r_idle:
+			flag = read_byte(f);
+			if ((flag & 0xC0) == DEFLATED_DATA) {
+				n = ((flag & 0x3f) << 8) + read_byte(f);
+				read_buf(f, cbuf, n);
+
+				zstd_in_buff.size = n;
+				zstd_in_buff.pos = 0;
+
+				recv_state = r_inflating;
+				break;
+			}
+
+			if (flag == END_FLAG) {
+				/* that's all folks */
+				recv_state = r_init;
+				return 0;
+			}
+			/* here we have a token of some kind */
+			if (flag & TOKEN_REL) {
+				rx_token += flag & 0x3f;
+				flag >>= 6;
+			} else
+				rx_token = read_int(f);
+			if (flag & 1) {
+				rx_run = read_byte(f);
+				rx_run += read_byte(f) << 8;
+				recv_state = r_running;
+			}
+			return -1 - rx_token;
+
+		case r_inflated: /* zstd doesn't get into this state */
+			break;
+
+		case r_inflating:
+			zstd_out_buff.size = out_buffer_size;
+			zstd_out_buff.pos = 0;
+
+			r = ZSTD_decompressStream(zstd_dctx, &zstd_out_buff, &zstd_in_buff);
+			n = zstd_out_buff.pos;
+			if (ZSTD_isError(r)) {
+				rprintf(FERROR, "ZSTD decomp returned %d (%d bytes)\n", r, n);
+				exit_cleanup(RERR_STREAMIO);
+			}
+
+			/*
+			 * If the input buffer is fully consumed and the output
+			 * buffer is not full then next step is to read more
+			 * data.
+			 */
+			if (zstd_in_buff.size == zstd_in_buff.pos && n < out_buffer_size)
+				recv_state = r_idle;
+
+			if (n != 0) {
+				*data = dbuf;
+				return n;
+			}
+			break;
+
+		case r_running:
+			++rx_token;
+			if (--rx_run == 0)
+				recv_state = r_idle;
+			return -1 - rx_token;
+		}
+	}
+}
+#endif /* SUPPORT_ZSTD */
+
+#ifdef SUPPORT_LZ4
+static void
+send_compressed_token(int f, int32 token, struct map_struct *buf, OFF_T offset, int32 nb)
+{
+	static int init_done, flush_pending;
+	int size = MAX(LZ4_compressBound(CHUNK_SIZE), MAX_DATA_COUNT+2);
+	int32 n, r;
+
+	if (last_token == -1) {
+		if (!init_done) {
+			obuf = new_array(char, size);
+			init_done = 1;
+		}
+		last_run_end = 0;
+		run_start = token;
+		flush_pending = 0;
+	} else if (last_token == -2) {
+		run_start = token;
+	} else if (nb != 0 || token != last_token + 1 || token >= run_start + 65536) {
+		/* output previous run */
+		r = run_start - last_run_end;
+		n = last_token - run_start;
+		if (r >= 0 && r <= 63) {
+			write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
+		} else {
+			write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
+			write_int(f, run_start);
+		}
+		if (n != 0) {
+			write_byte(f, n);
+			write_byte(f, n >> 8);
+		}
+		last_run_end = last_token;
+		run_start = token;
+	}
+
+	last_token = token;
+
+	if (nb != 0 || flush_pending) {
+		int available_in, available_out = 0;
+		const char *next_in;
+
+		do {
+			char *next_out = obuf + 2;
+
+			if (available_out == 0) {
+				available_in = MIN(nb, MAX_DATA_COUNT);
+				next_in = map_ptr(buf, offset, available_in);
+			} else
+				available_in /= 2;
+
+			available_out = LZ4_compress_default(next_in, next_out, available_in, size - 2);
+			if (!available_out) {
+				rprintf(FERROR, "compress returned %d\n", available_out);
+				exit_cleanup(RERR_STREAMIO);
+			}
+			if (available_out <= MAX_DATA_COUNT) {
+				obuf[0] = DEFLATED_DATA + (available_out >> 8);
+				obuf[1] = available_out;
+
+				write_buf(f, obuf, available_out + 2);
+
+				available_out = 0;
+				nb -= available_in;
+				offset += available_in;
+			}
+		} while (nb != 0);
+		flush_pending = token == -2;
+	}
+	if (token == -1) {
+		/* end of file - clean up */
+		write_byte(f, END_FLAG);
+	}
+}
+
+static int32 recv_compressed_token(int f, char **data)
+{
+	static int init_done;
+	int32 n, flag;
+	int size = MAX(LZ4_compressBound(CHUNK_SIZE), MAX_DATA_COUNT+2);
+	static const char *next_in;
+	static int avail_in;
+	int avail_out;
+
+	for (;;) {
+		switch (recv_state) {
+		case r_init:
+			if (!init_done) {
+				cbuf = new_array(char, MAX_DATA_COUNT);
+				dbuf = new_array(char, size);
+				init_done = 1;
+			}
+			recv_state = r_idle;
+			rx_token = 0;
+			break;
+
+		case r_idle:
+			flag = read_byte(f);
+			if ((flag & 0xC0) == DEFLATED_DATA) {
+				n = ((flag & 0x3f) << 8) + read_byte(f);
+				read_buf(f, cbuf, n);
+				next_in = (char *)cbuf;
+				avail_in = n;
+				recv_state = r_inflating;
+				break;
+			}
+
+			if (flag == END_FLAG) {
+				/* that's all folks */
+				recv_state = r_init;
+				return 0;
+			}
+
+			/* here we have a token of some kind */
+			if (flag & TOKEN_REL) {
+				rx_token += flag & 0x3f;
+				flag >>= 6;
+			} else
+				rx_token = read_int(f);
+			if (flag & 1) {
+				rx_run = read_byte(f);
+				rx_run += read_byte(f) << 8;
+				recv_state = r_running;
+			}
+			return -1 - rx_token;
+
+		case r_inflating:
+			avail_out = LZ4_decompress_safe(next_in, dbuf, avail_in, size);
+			if (avail_out < 0) {
+				rprintf(FERROR, "uncompress failed: %d\n", avail_out);
+				exit_cleanup(RERR_STREAMIO);
+			}
+			recv_state = r_idle;
+			*data = dbuf;
+			return avail_out;
+
+		case r_inflated: /* lz4 doesn't get into this state */
+			break;
+
+		case r_running:
+			++rx_token;
+			if (--rx_run == 0)
+				recv_state = r_idle;
+			return -1 - rx_token;
+		}
+	}
+}
+#endif /* SUPPORT_LZ4 */
+
+/**
+ * Transmit a verbatim buffer of length @p n followed by a token.
+ * If token == -1 then we have reached EOF
+ * If n == 0 then don't send a buffer
+ */
+void send_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
+		int32 n, int32 toklen)
+{
+	switch (do_compression) {
+	case CPRES_NONE:
+		simple_send_token(f, token, buf, offset, n);
+		break;
+	case CPRES_ZLIB:
+	case CPRES_ZLIBX:
+		send_deflated_token(f, token, buf, offset, n, toklen);
+		break;
+#ifdef SUPPORT_ZSTD
+	case CPRES_ZSTD:
+		send_zstd_token(f, token, buf, offset, n);
+		break;
+#endif
+#ifdef SUPPORT_LZ4
+	case CPRES_LZ4:
+		send_compressed_token(f, token, buf, offset, n);
+		break;
+#endif
+	default:
+		NOISY_DEATH("Unknown do_compression value");
+	}
+}
+
+/*
+ * receive a token or buffer from the other end. If the return value is >0 then
+ * it is a data buffer of that length, and *data will point at the data.
+ * if the return value is -i then it represents token i-1
+ * if the return value is 0 then the end has been reached
+ */
+int32 recv_token(int f, char **data)
+{
+	switch (do_compression) {
+	case CPRES_NONE:
+		return simple_recv_token(f,data);
+	case CPRES_ZLIB:
+	case CPRES_ZLIBX:
+		return recv_deflated_token(f, data);
+#ifdef SUPPORT_ZSTD
+	case CPRES_ZSTD:
+		return recv_zstd_token(f, data);
+#endif
+#ifdef SUPPORT_LZ4
+	case CPRES_LZ4:
+		return recv_compressed_token(f, data);
+#endif
+	default:
+		NOISY_DEATH("Unknown do_compression value");
+	}
+}
+
+/*
+ * look at the data corresponding to a token, if necessary
+ */
+void see_token(char *data, int32 toklen)
+{
+	switch (do_compression) {
+	case CPRES_NONE:
+		break;
+	case CPRES_ZLIB:
+		see_deflate_token(data, toklen);
+		break;
+	case CPRES_ZLIBX:
+		break;
+#ifdef SUPPORT_ZSTD
+	case CPRES_ZSTD:
+		break;
+#endif
+#ifdef SUPPORT_LZ4
+	case CPRES_LZ4:
+		/*see_uncompressed_token(data, toklen);*/
+		break;
+#endif
+	default:
+		NOISY_DEATH("Unknown do_compression value");
+	}
+}