Adding upstream version 2.6.12.upstream/2.6.12upstream

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

1 files changed, 740 insertions, 0 deletions

diff --git a/src/compression.c b/src/compression.c
new file mode 100644
index 0000000..3ce2a60
--- /dev/null
+++ b/src/compression.c
@@ -0,0 +1,740 @@
+/*
+ * HTTP compression.
+ *
+ * Copyright 2012 Exceliance, David Du Colombier <dducolombier@exceliance.fr>
+ *                            William Lallemand <wlallemand@exceliance.fr>
+ *
+ * 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 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <stdio.h>
+
+#if defined(USE_ZLIB)
+/* Note: the crappy zlib and openssl libs both define the "free_func" type.
+ * That's a very clever idea to use such a generic name in general purpose
+ * libraries, really... The zlib one is easier to redefine than openssl's,
+ * so let's only fix this one.
+ */
+#define free_func zlib_free_func
+#include <zlib.h>
+#undef free_func
+#endif /* USE_ZLIB */
+
+#include <haproxy/api.h>
+#include <haproxy/cfgparse.h>
+#include <haproxy/compression-t.h>
+#include <haproxy/compression.h>
+#include <haproxy/dynbuf.h>
+#include <haproxy/freq_ctr.h>
+#include <haproxy/global.h>
+#include <haproxy/pool.h>
+#include <haproxy/stream.h>
+#include <haproxy/thread.h>
+#include <haproxy/tools.h>
+
+
+#if defined(USE_ZLIB)
+__decl_spinlock(comp_pool_lock);
+#endif
+
+#ifdef USE_ZLIB
+
+static void *alloc_zlib(void *opaque, unsigned int items, unsigned int size);
+static void free_zlib(void *opaque, void *ptr);
+
+/* zlib allocation  */
+static struct pool_head *zlib_pool_deflate_state __read_mostly = NULL;
+static struct pool_head *zlib_pool_window __read_mostly = NULL;
+static struct pool_head *zlib_pool_prev __read_mostly = NULL;
+static struct pool_head *zlib_pool_head __read_mostly = NULL;
+static struct pool_head *zlib_pool_pending_buf __read_mostly = NULL;
+
+long zlib_used_memory = 0;
+
+static int global_tune_zlibmemlevel = 8;            /* zlib memlevel */
+static int global_tune_zlibwindowsize = MAX_WBITS;  /* zlib window size */
+
+#endif
+
+unsigned int compress_min_idle = 0;
+
+static int identity_init(struct comp_ctx **comp_ctx, int level);
+static int identity_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out);
+static int identity_flush(struct comp_ctx *comp_ctx, struct buffer *out);
+static int identity_finish(struct comp_ctx *comp_ctx, struct buffer *out);
+static int identity_end(struct comp_ctx **comp_ctx);
+
+#if defined(USE_SLZ)
+
+static int rfc1950_init(struct comp_ctx **comp_ctx, int level);
+static int rfc1951_init(struct comp_ctx **comp_ctx, int level);
+static int rfc1952_init(struct comp_ctx **comp_ctx, int level);
+static int rfc195x_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out);
+static int rfc195x_flush(struct comp_ctx *comp_ctx, struct buffer *out);
+static int rfc195x_finish(struct comp_ctx *comp_ctx, struct buffer *out);
+static int rfc195x_end(struct comp_ctx **comp_ctx);
+
+#elif defined(USE_ZLIB)
+
+static int gzip_init(struct comp_ctx **comp_ctx, int level);
+static int raw_def_init(struct comp_ctx **comp_ctx, int level);
+static int deflate_init(struct comp_ctx **comp_ctx, int level);
+static int deflate_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out);
+static int deflate_flush(struct comp_ctx *comp_ctx, struct buffer *out);
+static int deflate_finish(struct comp_ctx *comp_ctx, struct buffer *out);
+static int deflate_end(struct comp_ctx **comp_ctx);
+
+#endif /* USE_ZLIB */
+
+
+const struct comp_algo comp_algos[] =
+{
+	{ "identity",     8, "identity", 8, identity_init, identity_add_data, identity_flush, identity_finish, identity_end },
+#if defined(USE_SLZ)
+	{ "deflate",      7, "deflate",  7, rfc1950_init,  rfc195x_add_data,  rfc195x_flush,  rfc195x_finish,  rfc195x_end },
+	{ "raw-deflate", 11, "deflate",  7, rfc1951_init,  rfc195x_add_data,  rfc195x_flush,  rfc195x_finish,  rfc195x_end },
+	{ "gzip",         4, "gzip",     4, rfc1952_init,  rfc195x_add_data,  rfc195x_flush,  rfc195x_finish,  rfc195x_end },
+#elif defined(USE_ZLIB)
+	{ "deflate",      7, "deflate",  7, deflate_init,  deflate_add_data,  deflate_flush,  deflate_finish,  deflate_end },
+	{ "raw-deflate", 11, "deflate",  7, raw_def_init,  deflate_add_data,  deflate_flush,  deflate_finish,  deflate_end },
+	{ "gzip",         4, "gzip",     4, gzip_init,     deflate_add_data,  deflate_flush,  deflate_finish,  deflate_end },
+#endif /* USE_ZLIB */
+	{ NULL,       0, NULL,          0, NULL ,         NULL,              NULL,           NULL,           NULL }
+};
+
+/*
+ * Add a content-type in the configuration
+ * Returns 0 in case of success, 1 in case of allocation failure.
+ */
+int comp_append_type(struct comp *comp, const char *type)
+{
+	struct comp_type *comp_type;
+
+	comp_type = calloc(1, sizeof(*comp_type));
+	if (!comp_type)
+		return 1;
+	comp_type->name_len = strlen(type);
+	comp_type->name = strdup(type);
+	comp_type->next = comp->types;
+	comp->types = comp_type;
+	return 0;
+}
+
+/*
+ * Add an algorithm in the configuration
+ * Returns 0 in case of success, -1 if the <algo> is unmanaged, 1 in case of
+ * allocation failure.
+ */
+int comp_append_algo(struct comp *comp, const char *algo)
+{
+	struct comp_algo *comp_algo;
+	int i;
+
+	for (i = 0; comp_algos[i].cfg_name; i++) {
+		if (strcmp(algo, comp_algos[i].cfg_name) == 0) {
+			comp_algo = calloc(1, sizeof(*comp_algo));
+			if (!comp_algo)
+				return 1;
+			memmove(comp_algo, &comp_algos[i], sizeof(struct comp_algo));
+			comp_algo->next = comp->algos;
+			comp->algos = comp_algo;
+			return 0;
+		}
+	}
+	return -1;
+}
+
+#if defined(USE_ZLIB) || defined(USE_SLZ)
+DECLARE_STATIC_POOL(pool_comp_ctx, "comp_ctx", sizeof(struct comp_ctx));
+
+/*
+ * Alloc the comp_ctx
+ */
+static inline int init_comp_ctx(struct comp_ctx **comp_ctx)
+{
+#ifdef USE_ZLIB
+	z_stream *strm;
+
+	if (global.maxzlibmem > 0 && (global.maxzlibmem - zlib_used_memory) < sizeof(struct comp_ctx))
+		return -1;
+#endif
+
+	*comp_ctx = pool_alloc(pool_comp_ctx);
+	if (*comp_ctx == NULL)
+		return -1;
+#if defined(USE_SLZ)
+	(*comp_ctx)->direct_ptr = NULL;
+	(*comp_ctx)->direct_len = 0;
+	(*comp_ctx)->queued = BUF_NULL;
+#elif defined(USE_ZLIB)
+	_HA_ATOMIC_ADD(&zlib_used_memory, sizeof(struct comp_ctx));
+	__ha_barrier_atomic_store();
+
+	strm = &(*comp_ctx)->strm;
+	strm->zalloc = alloc_zlib;
+	strm->zfree = free_zlib;
+	strm->opaque = *comp_ctx;
+#endif
+	return 0;
+}
+
+/*
+ * Dealloc the comp_ctx
+ */
+static inline int deinit_comp_ctx(struct comp_ctx **comp_ctx)
+{
+	if (!*comp_ctx)
+		return 0;
+
+	pool_free(pool_comp_ctx, *comp_ctx);
+	*comp_ctx = NULL;
+
+#ifdef USE_ZLIB
+	_HA_ATOMIC_SUB(&zlib_used_memory, sizeof(struct comp_ctx));
+	__ha_barrier_atomic_store();
+#endif
+	return 0;
+}
+#endif
+
+
+/****************************
+ **** Identity algorithm ****
+ ****************************/
+
+/*
+ * Init the identity algorithm
+ */
+static int identity_init(struct comp_ctx **comp_ctx, int level)
+{
+	return 0;
+}
+
+/*
+ * Process data
+ *   Return size of consumed data or -1 on error
+ */
+static int identity_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out)
+{
+	char *out_data = b_tail(out);
+	int out_len = b_room(out);
+
+	if (out_len < in_len)
+		return -1;
+
+	memcpy(out_data, in_data, in_len);
+
+	b_add(out, in_len);
+
+	return in_len;
+}
+
+static int identity_flush(struct comp_ctx *comp_ctx, struct buffer *out)
+{
+	return 0;
+}
+
+static int identity_finish(struct comp_ctx *comp_ctx, struct buffer *out)
+{
+	return 0;
+}
+
+/*
+ * Deinit the algorithm
+ */
+static int identity_end(struct comp_ctx **comp_ctx)
+{
+	return 0;
+}
+
+
+#ifdef USE_SLZ
+
+/* SLZ's gzip format (RFC1952). Returns < 0 on error. */
+static int rfc1952_init(struct comp_ctx **comp_ctx, int level)
+{
+	if (init_comp_ctx(comp_ctx) < 0)
+		return -1;
+
+	(*comp_ctx)->cur_lvl = !!level;
+	return slz_rfc1952_init(&(*comp_ctx)->strm, !!level);
+}
+
+/* SLZ's raw deflate format (RFC1951). Returns < 0 on error. */
+static int rfc1951_init(struct comp_ctx **comp_ctx, int level)
+{
+	if (init_comp_ctx(comp_ctx) < 0)
+		return -1;
+
+	(*comp_ctx)->cur_lvl = !!level;
+	return slz_rfc1951_init(&(*comp_ctx)->strm, !!level);
+}
+
+/* SLZ's zlib format (RFC1950). Returns < 0 on error. */
+static int rfc1950_init(struct comp_ctx **comp_ctx, int level)
+{
+	if (init_comp_ctx(comp_ctx) < 0)
+		return -1;
+
+	(*comp_ctx)->cur_lvl = !!level;
+	return slz_rfc1950_init(&(*comp_ctx)->strm, !!level);
+}
+
+/* Return the size of consumed data or -1. The output buffer is unused at this
+ * point, we only keep a reference to the input data or a copy of them if the
+ * reference is already used.
+ */
+static int rfc195x_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out)
+{
+	static THREAD_LOCAL struct buffer tmpbuf = BUF_NULL;
+
+	if (in_len <= 0)
+		return 0;
+
+	if (comp_ctx->direct_ptr && b_is_null(&comp_ctx->queued)) {
+		/* data already being pointed to, we're in front of fragmented
+		 * data and need a buffer now. We reuse the same buffer, as it's
+		 * not used out of the scope of a series of add_data()*, end().
+		 */
+		if (b_alloc(&tmpbuf) == NULL)
+			return -1; /* no memory */
+		b_reset(&tmpbuf);
+		memcpy(b_tail(&tmpbuf), comp_ctx->direct_ptr, comp_ctx->direct_len);
+		b_add(&tmpbuf, comp_ctx->direct_len);
+		comp_ctx->direct_ptr = NULL;
+		comp_ctx->direct_len = 0;
+		comp_ctx->queued = tmpbuf;
+		/* fall through buffer copy */
+	}
+
+	if (!b_is_null(&comp_ctx->queued)) {
+		/* data already pending */
+		memcpy(b_tail(&comp_ctx->queued), in_data, in_len);
+		b_add(&comp_ctx->queued, in_len);
+		return in_len;
+	}
+
+	comp_ctx->direct_ptr = in_data;
+	comp_ctx->direct_len = in_len;
+	return in_len;
+}
+
+/* Compresses the data accumulated using add_data(), and optionally sends the
+ * format-specific trailer if <finish> is non-null. <out> is expected to have a
+ * large enough free non-wrapping space as verified by http_comp_buffer_init().
+ * The number of bytes emitted is reported.
+ */
+static int rfc195x_flush_or_finish(struct comp_ctx *comp_ctx, struct buffer *out, int finish)
+{
+	struct slz_stream *strm = &comp_ctx->strm;
+	const char *in_ptr;
+	int in_len;
+	int out_len;
+
+	in_ptr = comp_ctx->direct_ptr;
+	in_len = comp_ctx->direct_len;
+
+	if (!b_is_null(&comp_ctx->queued)) {
+		in_ptr = b_head(&comp_ctx->queued);
+		in_len = b_data(&comp_ctx->queued);
+	}
+
+	out_len = b_data(out);
+
+	if (in_ptr)
+		b_add(out, slz_encode(strm, b_tail(out), in_ptr, in_len, !finish));
+
+	if (finish)
+		b_add(out, slz_finish(strm, b_tail(out)));
+
+	out_len = b_data(out) - out_len;
+
+	/* very important, we must wipe the data we've just flushed */
+	comp_ctx->direct_len = 0;
+	comp_ctx->direct_ptr = NULL;
+	comp_ctx->queued     = BUF_NULL;
+
+	/* Verify compression rate limiting and CPU usage */
+	if ((global.comp_rate_lim > 0 && (read_freq_ctr(&global.comp_bps_out) > global.comp_rate_lim)) ||    /* rate */
+	   (th_ctx->idle_pct < compress_min_idle)) {                                                         /* idle */
+		if (comp_ctx->cur_lvl > 0)
+			strm->level = --comp_ctx->cur_lvl;
+	}
+	else if (comp_ctx->cur_lvl < global.tune.comp_maxlevel && comp_ctx->cur_lvl < 1) {
+		strm->level = ++comp_ctx->cur_lvl;
+	}
+
+	/* and that's all */
+	return out_len;
+}
+
+static int rfc195x_flush(struct comp_ctx *comp_ctx, struct buffer *out)
+{
+	return rfc195x_flush_or_finish(comp_ctx, out, 0);
+}
+
+static int rfc195x_finish(struct comp_ctx *comp_ctx, struct buffer *out)
+{
+	return rfc195x_flush_or_finish(comp_ctx, out, 1);
+}
+
+/* we just need to free the comp_ctx here, nothing was allocated */
+static int rfc195x_end(struct comp_ctx **comp_ctx)
+{
+	deinit_comp_ctx(comp_ctx);
+	return 0;
+}
+
+#elif defined(USE_ZLIB)  /* ! USE_SLZ */
+
+/*
+ * This is a tricky allocation function using the zlib.
+ * This is based on the allocation order in deflateInit2.
+ */
+static void *alloc_zlib(void *opaque, unsigned int items, unsigned int size)
+{
+	struct comp_ctx *ctx = opaque;
+	static THREAD_LOCAL char round = 0; /* order in deflateInit2 */
+	void *buf = NULL;
+	struct pool_head *pool = NULL;
+
+	if (global.maxzlibmem > 0 && (global.maxzlibmem - zlib_used_memory) < (long)(items * size))
+		goto end;
+
+	switch (round) {
+		case 0:
+			if (zlib_pool_deflate_state == NULL) {
+				HA_SPIN_LOCK(COMP_POOL_LOCK, &comp_pool_lock);
+				if (zlib_pool_deflate_state == NULL)
+					zlib_pool_deflate_state = create_pool("zlib_state", size * items, MEM_F_SHARED);
+				HA_SPIN_UNLOCK(COMP_POOL_LOCK, &comp_pool_lock);
+			}
+			pool = zlib_pool_deflate_state;
+			ctx->zlib_deflate_state = buf = pool_alloc(pool);
+		break;
+
+		case 1:
+			if (zlib_pool_window == NULL) {
+				HA_SPIN_LOCK(COMP_POOL_LOCK, &comp_pool_lock);
+				if (zlib_pool_window == NULL)
+					zlib_pool_window = create_pool("zlib_window", size * items, MEM_F_SHARED);
+				HA_SPIN_UNLOCK(COMP_POOL_LOCK, &comp_pool_lock);
+			}
+			pool = zlib_pool_window;
+			ctx->zlib_window = buf = pool_alloc(pool);
+		break;
+
+		case 2:
+			if (zlib_pool_prev == NULL) {
+				HA_SPIN_LOCK(COMP_POOL_LOCK, &comp_pool_lock);
+				if (zlib_pool_prev == NULL)
+					zlib_pool_prev = create_pool("zlib_prev", size * items, MEM_F_SHARED);
+				HA_SPIN_UNLOCK(COMP_POOL_LOCK, &comp_pool_lock);
+			}
+			pool = zlib_pool_prev;
+			ctx->zlib_prev = buf = pool_alloc(pool);
+		break;
+
+		case 3:
+			if (zlib_pool_head == NULL) {
+				HA_SPIN_LOCK(COMP_POOL_LOCK, &comp_pool_lock);
+				if (zlib_pool_head == NULL)
+					zlib_pool_head = create_pool("zlib_head", size * items, MEM_F_SHARED);
+				HA_SPIN_UNLOCK(COMP_POOL_LOCK, &comp_pool_lock);
+			}
+			pool = zlib_pool_head;
+			ctx->zlib_head = buf = pool_alloc(pool);
+		break;
+
+		case 4:
+			if (zlib_pool_pending_buf == NULL) {
+				HA_SPIN_LOCK(COMP_POOL_LOCK, &comp_pool_lock);
+				if (zlib_pool_pending_buf == NULL)
+					zlib_pool_pending_buf = create_pool("zlib_pending_buf", size * items, MEM_F_SHARED);
+				HA_SPIN_UNLOCK(COMP_POOL_LOCK, &comp_pool_lock);
+			}
+			pool = zlib_pool_pending_buf;
+			ctx->zlib_pending_buf = buf = pool_alloc(pool);
+		break;
+	}
+	if (buf != NULL) {
+		_HA_ATOMIC_ADD(&zlib_used_memory, pool->size);
+		__ha_barrier_atomic_store();
+	}
+
+end:
+
+	/* deflateInit2() first allocates and checks the deflate_state, then if
+	 * it succeeds, it allocates all other 4 areas at ones and checks them
+	 * at the end. So we want to correctly count the rounds depending on when
+	 * zlib is supposed to abort.
+	 */
+	if (buf || round)
+		round = (round + 1) % 5;
+	return buf;
+}
+
+static void free_zlib(void *opaque, void *ptr)
+{
+	struct comp_ctx *ctx = opaque;
+	struct pool_head *pool = NULL;
+
+	if (ptr == ctx->zlib_window)
+		pool = zlib_pool_window;
+	else if (ptr == ctx->zlib_deflate_state)
+		pool = zlib_pool_deflate_state;
+	else if (ptr == ctx->zlib_prev)
+		pool = zlib_pool_prev;
+	else if (ptr == ctx->zlib_head)
+		pool = zlib_pool_head;
+	else if (ptr == ctx->zlib_pending_buf)
+		pool = zlib_pool_pending_buf;
+	else {
+		// never matched, just to silence gcc
+		ABORT_NOW();
+		return;
+	}
+
+	pool_free(pool, ptr);
+	_HA_ATOMIC_SUB(&zlib_used_memory, pool->size);
+	__ha_barrier_atomic_store();
+}
+
+/**************************
+****  gzip algorithm   ****
+***************************/
+static int gzip_init(struct comp_ctx **comp_ctx, int level)
+{
+	z_stream *strm;
+
+	if (init_comp_ctx(comp_ctx) < 0)
+		return -1;
+
+	strm = &(*comp_ctx)->strm;
+
+	if (deflateInit2(strm, level, Z_DEFLATED, global_tune_zlibwindowsize + 16, global_tune_zlibmemlevel, Z_DEFAULT_STRATEGY) != Z_OK) {
+		deinit_comp_ctx(comp_ctx);
+		return -1;
+	}
+
+	(*comp_ctx)->cur_lvl = level;
+
+	return 0;
+}
+
+/* Raw deflate algorithm */
+static int raw_def_init(struct comp_ctx **comp_ctx, int level)
+{
+	z_stream *strm;
+
+	if (init_comp_ctx(comp_ctx) < 0)
+		return -1;
+
+	strm = &(*comp_ctx)->strm;
+
+	if (deflateInit2(strm, level, Z_DEFLATED, -global_tune_zlibwindowsize, global_tune_zlibmemlevel, Z_DEFAULT_STRATEGY) != Z_OK) {
+		deinit_comp_ctx(comp_ctx);
+		return -1;
+	}
+
+	(*comp_ctx)->cur_lvl = level;
+	return 0;
+}
+
+/**************************
+**** Deflate algorithm ****
+***************************/
+
+static int deflate_init(struct comp_ctx **comp_ctx, int level)
+{
+	z_stream *strm;
+
+	if (init_comp_ctx(comp_ctx) < 0)
+		return -1;
+
+	strm = &(*comp_ctx)->strm;
+
+	if (deflateInit2(strm, level, Z_DEFLATED, global_tune_zlibwindowsize, global_tune_zlibmemlevel, Z_DEFAULT_STRATEGY) != Z_OK) {
+		deinit_comp_ctx(comp_ctx);
+		return -1;
+	}
+
+	(*comp_ctx)->cur_lvl = level;
+
+	return 0;
+}
+
+/* Return the size of consumed data or -1 */
+static int deflate_add_data(struct comp_ctx *comp_ctx, const char *in_data, int in_len, struct buffer *out)
+{
+	int ret;
+	z_stream *strm = &comp_ctx->strm;
+	char *out_data = b_tail(out);
+	int out_len = b_room(out);
+
+	if (in_len <= 0)
+		return 0;
+
+
+	if (out_len <= 0)
+		return -1;
+
+	strm->next_in = (unsigned char *)in_data;
+	strm->avail_in = in_len;
+	strm->next_out = (unsigned char *)out_data;
+	strm->avail_out = out_len;
+
+	ret = deflate(strm, Z_NO_FLUSH);
+	if (ret != Z_OK)
+		return -1;
+
+	/* deflate update the available data out */
+	b_add(out, out_len - strm->avail_out);
+
+	return in_len - strm->avail_in;
+}
+
+static int deflate_flush_or_finish(struct comp_ctx *comp_ctx, struct buffer *out, int flag)
+{
+	int ret;
+	int out_len = 0;
+	z_stream *strm = &comp_ctx->strm;
+
+	strm->next_in = NULL;
+	strm->avail_in = 0;
+	strm->next_out = (unsigned char *)b_tail(out);
+	strm->avail_out = b_room(out);
+
+	ret = deflate(strm, flag);
+	if (ret != Z_OK && ret != Z_STREAM_END)
+		return -1;
+
+	out_len = b_room(out) - strm->avail_out;
+	b_add(out, out_len);
+
+	/* compression limit */
+	if ((global.comp_rate_lim > 0 && (read_freq_ctr(&global.comp_bps_out) > global.comp_rate_lim)) ||    /* rate */
+	   (th_ctx->idle_pct < compress_min_idle)) {                                                         /* idle */
+		/* decrease level */
+		if (comp_ctx->cur_lvl > 0) {
+			comp_ctx->cur_lvl--;
+			deflateParams(&comp_ctx->strm, comp_ctx->cur_lvl, Z_DEFAULT_STRATEGY);
+		}
+
+	} else if (comp_ctx->cur_lvl < global.tune.comp_maxlevel) {
+		/* increase level */
+		comp_ctx->cur_lvl++ ;
+		deflateParams(&comp_ctx->strm, comp_ctx->cur_lvl, Z_DEFAULT_STRATEGY);
+	}
+
+	return out_len;
+}
+
+static int deflate_flush(struct comp_ctx *comp_ctx, struct buffer *out)
+{
+	return deflate_flush_or_finish(comp_ctx, out, Z_SYNC_FLUSH);
+}
+
+static int deflate_finish(struct comp_ctx *comp_ctx, struct buffer *out)
+{
+	return deflate_flush_or_finish(comp_ctx, out, Z_FINISH);
+}
+
+static int deflate_end(struct comp_ctx **comp_ctx)
+{
+	z_stream *strm = &(*comp_ctx)->strm;
+	int ret;
+
+	ret = deflateEnd(strm);
+
+	deinit_comp_ctx(comp_ctx);
+
+	return ret;
+}
+
+/* config parser for global "tune.zlibmemlevel" */
+static int zlib_parse_global_memlevel(char **args, int section_type, struct proxy *curpx,
+                                      const struct proxy *defpx, const char *file, int line,
+                                      char **err)
+{
+        if (too_many_args(1, args, err, NULL))
+                return -1;
+
+        if (*(args[1]) == 0) {
+                memprintf(err, "'%s' expects a numeric value between 1 and 9.", args[0]);
+                return -1;
+        }
+
+	global_tune_zlibmemlevel = atoi(args[1]);
+	if (global_tune_zlibmemlevel < 1 || global_tune_zlibmemlevel > 9) {
+                memprintf(err, "'%s' expects a numeric value between 1 and 9.", args[0]);
+                return -1;
+	}
+        return 0;
+}
+
+
+/* config parser for global "tune.zlibwindowsize" */
+static int zlib_parse_global_windowsize(char **args, int section_type, struct proxy *curpx,
+                                        const struct proxy *defpx, const char *file, int line,
+                                        char **err)
+{
+        if (too_many_args(1, args, err, NULL))
+                return -1;
+
+        if (*(args[1]) == 0) {
+                memprintf(err, "'%s' expects a numeric value between 8 and 15.", args[0]);
+                return -1;
+        }
+
+	global_tune_zlibwindowsize = atoi(args[1]);
+	if (global_tune_zlibwindowsize < 8 || global_tune_zlibwindowsize > 15) {
+                memprintf(err, "'%s' expects a numeric value between 8 and 15.", args[0]);
+                return -1;
+	}
+        return 0;
+}
+
+#endif /* USE_ZLIB */
+
+
+/* config keyword parsers */
+static struct cfg_kw_list cfg_kws = {ILH, {
+#ifdef USE_ZLIB
+	{ CFG_GLOBAL, "tune.zlib.memlevel",   zlib_parse_global_memlevel },
+	{ CFG_GLOBAL, "tune.zlib.windowsize", zlib_parse_global_windowsize },
+#endif
+	{ 0, NULL, NULL }
+}};
+
+INITCALL1(STG_REGISTER, cfg_register_keywords, &cfg_kws);
+
+static void comp_register_build_opts(void)
+{
+	char *ptr = NULL;
+	int i;
+
+#ifdef USE_ZLIB
+	memprintf(&ptr, "Built with zlib version : " ZLIB_VERSION);
+	memprintf(&ptr, "%s\nRunning on zlib version : %s", ptr, zlibVersion());
+#elif defined(USE_SLZ)
+	memprintf(&ptr, "Built with libslz for stateless compression.");
+#else
+	memprintf(&ptr, "Built without compression support (neither USE_ZLIB nor USE_SLZ are set).");
+#endif
+	memprintf(&ptr, "%s\nCompression algorithms supported :", ptr);
+
+	for (i = 0; comp_algos[i].cfg_name; i++)
+		memprintf(&ptr, "%s%s %s(\"%s\")", ptr, (i == 0 ? "" : ","), comp_algos[i].cfg_name, comp_algos[i].ua_name);
+
+	if (i == 0)
+		memprintf(&ptr, "%s none", ptr);
+
+	hap_register_build_opts(ptr, 1);
+}
+
+INITCALL0(STG_REGISTER, comp_register_build_opts);