Adding upstream version 2.9.5.upstream/2.9.5

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

1 files changed, 3014 insertions, 0 deletions

diff --git a/src/cache.c b/src/cache.c
new file mode 100644
index 0000000..9f12f10
--- /dev/null
+++ b/src/cache.c
@@ -0,0 +1,3014 @@
+/*
+ * Cache management
+ *
+ * Copyright 2017 HAProxy Technologies
+ * William Lallemand <wlallemand@haproxy.com>
+ *
+ * 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 <import/eb32tree.h>
+#include <import/sha1.h>
+
+#include <haproxy/action-t.h>
+#include <haproxy/api.h>
+#include <haproxy/applet.h>
+#include <haproxy/cfgparse.h>
+#include <haproxy/channel.h>
+#include <haproxy/cli.h>
+#include <haproxy/errors.h>
+#include <haproxy/filters.h>
+#include <haproxy/hash.h>
+#include <haproxy/http.h>
+#include <haproxy/http_ana.h>
+#include <haproxy/http_htx.h>
+#include <haproxy/http_rules.h>
+#include <haproxy/htx.h>
+#include <haproxy/net_helper.h>
+#include <haproxy/proxy.h>
+#include <haproxy/sample.h>
+#include <haproxy/sc_strm.h>
+#include <haproxy/shctx.h>
+#include <haproxy/stconn.h>
+#include <haproxy/stream.h>
+#include <haproxy/tools.h>
+#include <haproxy/xxhash.h>
+
+#define CACHE_FLT_F_IMPLICIT_DECL  0x00000001 /* The cache filtre was implicitly declared (ie without
+					       * the filter keyword) */
+#define CACHE_FLT_INIT             0x00000002 /* Whether the cache name was freed. */
+
+static uint64_t cache_hash_seed = 0;
+
+const char *cache_store_flt_id = "cache store filter";
+
+extern struct applet http_cache_applet;
+
+struct flt_ops cache_ops;
+
+struct cache_tree {
+	struct eb_root entries;  /* head of cache entries based on keys */
+	__decl_thread(HA_RWLOCK_T lock);
+
+	struct list cleanup_list;
+	__decl_thread(HA_SPINLOCK_T cleanup_lock);
+} ALIGNED(64);
+
+struct cache {
+	struct cache_tree trees[CACHE_TREE_NUM];
+	struct list list;        /* cache linked list */
+	unsigned int maxage;     /* max-age */
+	unsigned int maxblocks;
+	unsigned int maxobjsz;   /* max-object-size (in bytes) */
+	unsigned int max_secondary_entries;  /* maximum number of secondary entries with the same primary hash */
+	uint8_t vary_processing_enabled;     /* boolean : manage Vary header (disabled by default) */
+	char id[33];             /* cache name */
+};
+
+/* the appctx context of a cache applet, stored in appctx->svcctx */
+struct cache_appctx {
+	struct cache_tree *cache_tree;
+	struct cache_entry *entry;       /* Entry to be sent from cache. */
+	unsigned int sent;               /* The number of bytes already sent for this cache entry. */
+	unsigned int offset;             /* start offset of remaining data relative to beginning of the next block */
+	unsigned int rem_data;           /* Remaining bytes for the last data block (HTX only, 0 means process next block) */
+	unsigned int send_notmodified:1; /* In case of conditional request, we might want to send a "304 Not Modified" response instead of the stored data. */
+	unsigned int unused:31;
+	struct shared_block *next;       /* The next block of data to be sent for this cache entry. */
+};
+
+/* cache config for filters */
+struct cache_flt_conf {
+	union {
+		struct cache *cache; /* cache used by the filter */
+		char *name;          /* cache name used during conf parsing */
+	} c;
+	unsigned int flags;   /* CACHE_FLT_F_* */
+};
+
+/* CLI context used during "show cache" */
+struct show_cache_ctx {
+	struct cache *cache;
+	struct cache_tree *cache_tree;
+	uint next_key;
+};
+
+
+/*
+ * Vary-related structures and functions
+ */
+enum vary_header_bit {
+	VARY_ACCEPT_ENCODING = (1 << 0),
+	VARY_REFERER =         (1 << 1),
+	VARY_ORIGIN =          (1 << 2),
+	VARY_LAST  /* should always be last */
+};
+
+/*
+ * Encoding list extracted from
+ * https://www.iana.org/assignments/http-parameters/http-parameters.xhtml
+ * and RFC7231#5.3.4.
+ */
+enum vary_encoding {
+	VARY_ENCODING_GZIP =		(1 << 0),
+	VARY_ENCODING_DEFLATE =		(1 << 1),
+	VARY_ENCODING_BR =		(1 << 2),
+	VARY_ENCODING_COMPRESS =	(1 << 3),
+	VARY_ENCODING_AES128GCM =	(1 << 4),
+	VARY_ENCODING_EXI =		(1 << 5),
+	VARY_ENCODING_PACK200_GZIP =	(1 << 6),
+	VARY_ENCODING_ZSTD =		(1 << 7),
+	VARY_ENCODING_IDENTITY =	(1 << 8),
+	VARY_ENCODING_STAR =		(1 << 9),
+	VARY_ENCODING_OTHER =		(1 << 10)
+};
+
+struct vary_hashing_information {
+	struct ist hdr_name;                 /* Header name */
+	enum vary_header_bit value;          /* Bit representing the header in a vary signature */
+	unsigned int hash_length;            /* Size of the sub hash for this header's value */
+	int(*norm_fn)(struct htx*,struct ist hdr_name,char* buf,unsigned int* buf_len);  /* Normalization function */
+	int(*cmp_fn)(const void *ref, const void *new, unsigned int len); /* Comparison function, should return 0 if the hashes are alike */
+};
+
+static int http_request_prebuild_full_secondary_key(struct stream *s);
+static int http_request_build_secondary_key(struct stream *s, int vary_signature);
+static int http_request_reduce_secondary_key(unsigned int vary_signature,
+					     char prebuilt_key[HTTP_CACHE_SEC_KEY_LEN]);
+
+static int parse_encoding_value(struct ist value, unsigned int *encoding_value,
+				unsigned int *has_null_weight);
+
+static int accept_encoding_normalizer(struct htx *htx, struct ist hdr_name,
+				      char *buf, unsigned int *buf_len);
+static int default_normalizer(struct htx *htx, struct ist hdr_name,
+			      char *buf, unsigned int *buf_len);
+
+static int accept_encoding_bitmap_cmp(const void *ref, const void *new, unsigned int len);
+
+/* Warning : do not forget to update HTTP_CACHE_SEC_KEY_LEN when new items are
+ * added to this array. */
+const struct vary_hashing_information vary_information[] = {
+	{ IST("accept-encoding"), VARY_ACCEPT_ENCODING, sizeof(uint32_t), &accept_encoding_normalizer, &accept_encoding_bitmap_cmp },
+	{ IST("referer"), VARY_REFERER, sizeof(uint64_t), &default_normalizer, NULL },
+	{ IST("origin"), VARY_ORIGIN, sizeof(uint64_t), &default_normalizer, NULL },
+};
+
+
+static inline void cache_rdlock(struct cache_tree *cache)
+{
+	HA_RWLOCK_RDLOCK(CACHE_LOCK, &cache->lock);
+}
+
+static inline  void cache_rdunlock(struct cache_tree *cache)
+{
+	HA_RWLOCK_RDUNLOCK(CACHE_LOCK, &cache->lock);
+}
+
+static inline void cache_wrlock(struct cache_tree *cache)
+{
+	HA_RWLOCK_WRLOCK(CACHE_LOCK, &cache->lock);
+}
+
+static inline void cache_wrunlock(struct cache_tree *cache)
+{
+	HA_RWLOCK_WRUNLOCK(CACHE_LOCK, &cache->lock);
+}
+
+/*
+ * cache ctx for filters
+ */
+struct cache_st {
+	struct shared_block *first_block;
+	struct list detached_head;
+};
+
+#define DEFAULT_MAX_SECONDARY_ENTRY 10
+
+struct cache_entry {
+	unsigned int complete;    /* An entry won't be valid until complete is not null. */
+	unsigned int latest_validation;     /* latest validation date */
+	unsigned int expire;      /* expiration date (wall clock time) */
+	unsigned int age;         /* Origin server "Age" header value */
+
+	int refcount;
+
+	struct eb32_node eb;     /* ebtree node used to hold the cache object */
+	char hash[20];
+
+	struct list cleanup_list;/* List used between the cache_free_blocks and cache_reserve_finish calls */
+
+	char secondary_key[HTTP_CACHE_SEC_KEY_LEN];  /* Optional secondary key. */
+	unsigned int secondary_key_signature;  /* Bitfield of the HTTP headers that should be used
+					        * to build secondary keys for this cache entry. */
+	unsigned int secondary_entries_count;  /* Should only be filled in the last entry of a list of dup entries */
+	unsigned int last_clear_ts;          /* Timestamp of the last call to clear_expired_duplicates. */
+
+	unsigned int etag_length; /* Length of the ETag value (if one was found in the response). */
+	unsigned int etag_offset; /* Offset of the ETag value in the data buffer. */
+
+	time_t last_modified; /* Origin server "Last-Modified" header value converted in
+			       * seconds since epoch. If no "Last-Modified"
+			       * header is found, use "Date" header value,
+			       * otherwise use reception time. This field will
+			       * be used in case of an "If-Modified-Since"-based
+			       * conditional request. */
+
+	unsigned char data[0];
+};
+
+#define CACHE_BLOCKSIZE 1024
+#define CACHE_ENTRY_MAX_AGE 2147483648U
+
+static struct list caches = LIST_HEAD_INIT(caches);
+static struct list caches_config = LIST_HEAD_INIT(caches_config); /* cache config to init */
+static struct cache *tmp_cache_config = NULL;
+
+DECLARE_STATIC_POOL(pool_head_cache_st, "cache_st", sizeof(struct cache_st));
+
+static struct eb32_node *insert_entry(struct cache *cache, struct cache_tree *tree, struct cache_entry *new_entry);
+static void delete_entry(struct cache_entry *del_entry);
+static void release_entry_locked(struct cache_tree *cache, struct cache_entry *entry);
+static void release_entry_unlocked(struct cache_tree *cache, struct cache_entry *entry);
+
+/*
+ * Find a cache_entry in the <cache>'s tree that has the hash <hash>.
+ * If <delete_expired> is 0 then the entry is left untouched if it is found but
+ * is already expired, and NULL is returned. Otherwise, the expired entry is
+ * removed from the tree and NULL is returned.
+ * Returns a valid (not expired) cache_tree pointer.
+ * The returned entry is not retained, it should be explicitly retained only
+ * when necessary.
+ *
+ * This function must be called under a cache lock, either read if
+ * delete_expired==0, write otherwise.
+ */
+struct cache_entry *get_entry(struct cache_tree *cache_tree, char *hash, int delete_expired)
+{
+	struct eb32_node *node;
+	struct cache_entry *entry;
+
+	node = eb32_lookup(&cache_tree->entries, read_u32(hash));
+	if (!node)
+		return NULL;
+
+	entry = eb32_entry(node, struct cache_entry, eb);
+
+	/* if that's not the right node */
+	if (memcmp(entry->hash, hash, sizeof(entry->hash)))
+		return NULL;
+
+	if (entry->expire > date.tv_sec) {
+		return entry;
+	} else if (delete_expired) {
+		release_entry_locked(cache_tree, entry);
+	}
+	return NULL;
+}
+
+/*
+ * Increment a cache_entry's reference counter.
+ */
+static void retain_entry(struct cache_entry *entry)
+{
+	if (entry)
+		HA_ATOMIC_INC(&entry->refcount);
+}
+
+/*
+ * Decrement a cache_entry's reference counter and remove it from the <cache>'s
+ * tree if the reference counter becomes 0.
+ * If <needs_locking> is 0 then the cache lock was already taken by the caller,
+ * otherwise it must be taken in write mode before actually deleting the entry.
+ */
+static void release_entry(struct cache_tree *cache, struct cache_entry *entry, int needs_locking)
+{
+	if (!entry)
+		return;
+
+	if (HA_ATOMIC_SUB_FETCH(&entry->refcount, 1) <= 0) {
+		if (needs_locking) {
+			cache_wrlock(cache);
+			/* The value might have changed between the last time we
+			 * checked it and now, we need to recheck it just in
+			 * case.
+			 */
+			if (HA_ATOMIC_LOAD(&entry->refcount) > 0) {
+				cache_wrunlock(cache);
+				return;
+			}
+		}
+		delete_entry(entry);
+		if (needs_locking) {
+			cache_wrunlock(cache);
+		}
+	}
+}
+
+/*
+ * Decrement a cache_entry's reference counter and remove it from the <cache>'s
+ * tree if the reference counter becomes 0.
+ * This function must be called under the cache lock in write mode.
+ */
+static inline void release_entry_locked(struct cache_tree *cache, struct cache_entry *entry)
+{
+	release_entry(cache, entry, 0);
+}
+
+/*
+ * Decrement a cache_entry's reference counter and remove it from the <cache>'s
+ * tree if the reference counter becomes 0.
+ * This function must not be called under the cache lock or the shctx lock. The
+ * cache lock might be taken in write mode (if the entry gets deleted).
+ */
+static inline void release_entry_unlocked(struct cache_tree *cache, struct cache_entry *entry)
+{
+	release_entry(cache, entry, 1);
+}
+
+
+/*
+ * Compare a newly built secondary key to the one found in a cache_entry.
+ * Every sub-part of the key is compared to the reference through the dedicated
+ * comparison function of the sub-part (that might do more than a simple
+ * memcmp).
+ * Returns 0 if the keys are alike.
+ */
+static int secondary_key_cmp(const char *ref_key, const char *new_key)
+{
+	int retval = 0;
+	size_t idx = 0;
+	unsigned int offset = 0;
+	const struct vary_hashing_information *info;
+
+	for (idx = 0; idx < sizeof(vary_information)/sizeof(*vary_information) && !retval; ++idx) {
+		info = &vary_information[idx];
+
+		if (info->cmp_fn)
+			retval = info->cmp_fn(&ref_key[offset], &new_key[offset], info->hash_length);
+		else
+			retval = memcmp(&ref_key[offset], &new_key[offset], info->hash_length);
+
+		offset += info->hash_length;
+	}
+
+	return retval;
+}
+
+/*
+ * There can be multiple entries with the same primary key in the ebtree so in
+ * order to get the proper one out of the list, we use a secondary_key.
+ * This function simply iterates over all the entries with the same primary_key
+ * until it finds the right one.
+ * If <delete_expired> is 0 then the entry is left untouched if it is found but
+ * is already expired, and NULL is returned. Otherwise, the expired entry is
+ * removed from the tree and NULL is returned.
+ * Returns the cache_entry in case of success, NULL otherwise.
+ *
+ * This function must be called under a cache lock, either read if
+ * delete_expired==0, write otherwise.
+ */
+struct cache_entry *get_secondary_entry(struct cache_tree *cache, struct cache_entry *entry,
+                                        const char *secondary_key, int delete_expired)
+{
+	struct eb32_node *node = &entry->eb;
+
+	if (!entry->secondary_key_signature)
+		return NULL;
+
+	while (entry && secondary_key_cmp(entry->secondary_key, secondary_key) != 0) {
+		node = eb32_next_dup(node);
+
+		/* Make the best use of this iteration and clear expired entries
+		 * when we find them. Calling delete_entry would be too costly
+		 * so we simply call eb32_delete. The secondary_entry count will
+		 * be updated when we try to insert a new entry to this list. */
+		if (entry->expire <= date.tv_sec && delete_expired) {
+			release_entry_locked(cache, entry);
+		}
+
+		entry = node ? eb32_entry(node, struct cache_entry, eb) : NULL;
+	}
+
+	/* Expired entry */
+	if (entry && entry->expire <= date.tv_sec) {
+		if (delete_expired) {
+			release_entry_locked(cache, entry);
+		}
+		entry = NULL;
+	}
+
+	return entry;
+}
+
+static inline struct cache_tree *get_cache_tree_from_hash(struct cache *cache, unsigned int hash)
+{
+	if (!cache)
+		return NULL;
+
+	return &cache->trees[hash % CACHE_TREE_NUM];
+}
+
+
+/*
+ * Remove all expired entries from a list of duplicates.
+ * Return the number of alive entries in the list and sets dup_tail to the
+ * current last item of the list.
+ *
+ * This function must be called under a cache write lock.
+ */
+static unsigned int clear_expired_duplicates(struct cache_tree *cache, struct eb32_node **dup_tail)
+{
+	unsigned int entry_count = 0;
+	struct cache_entry *entry = NULL;
+	struct eb32_node *prev = *dup_tail;
+	struct eb32_node *tail = NULL;
+
+	while (prev) {
+		entry = container_of(prev, struct cache_entry, eb);
+		prev = eb32_prev_dup(prev);
+		if (entry->expire <= date.tv_sec) {
+			release_entry_locked(cache, entry);
+		}
+		else {
+			if (!tail)
+				tail = &entry->eb;
+			++entry_count;
+		}
+	}
+
+	*dup_tail = tail;
+
+	return entry_count;
+}
+
+
+/*
+ * This function inserts a cache_entry in the cache's ebtree. In case of
+ * duplicate entries (vary), it then checks that the number of entries did not
+ * reach the max number of secondary entries. If this entry should not have been
+ * created, remove it.
+ * In the regular case (unique entries), this function does not do more than a
+ * simple insert. In case of secondary entries, it will at most cost an
+ * insertion+max_sec_entries time checks and entry deletion.
+ * Returns the newly inserted node in case of success, NULL otherwise.
+ *
+ * This function must be called under a cache write lock.
+ */
+static struct eb32_node *insert_entry(struct cache *cache, struct cache_tree *tree, struct cache_entry *new_entry)
+{
+	struct eb32_node *prev = NULL;
+	struct cache_entry *entry = NULL;
+	unsigned int entry_count = 0;
+	unsigned int last_clear_ts = date.tv_sec;
+
+	struct eb32_node *node = eb32_insert(&tree->entries, &new_entry->eb);
+
+	new_entry->refcount = 1;
+
+	/* We should not have multiple entries with the same primary key unless
+	 * the entry has a non null vary signature. */
+	if (!new_entry->secondary_key_signature)
+		return node;
+
+	prev = eb32_prev_dup(node);
+	if (prev != NULL) {
+		/* The last entry of a duplicate list should contain the current
+		 * number of entries in the list. */
+		entry = container_of(prev, struct cache_entry, eb);
+		entry_count = entry->secondary_entries_count;
+		last_clear_ts = entry->last_clear_ts;
+
+		if (entry_count >= cache->max_secondary_entries) {
+			/* Some entries of the duplicate list might be expired so
+			 * we will iterate over all the items in order to free some
+			 * space. In order to avoid going over the same list too
+			 * often, we first check the timestamp of the last check
+			 * performed. */
+			if (last_clear_ts == date.tv_sec) {
+				/* Too many entries for this primary key, clear the
+				 * one that was inserted. */
+				release_entry_locked(tree, entry);
+				return NULL;
+			}
+
+			entry_count = clear_expired_duplicates(tree, &prev);
+			if (entry_count >= cache->max_secondary_entries) {
+				/* Still too many entries for this primary key, delete
+				 * the newly inserted one. */
+				entry = container_of(prev, struct cache_entry, eb);
+				entry->last_clear_ts = date.tv_sec;
+				release_entry_locked(tree, entry);
+				return NULL;
+			}
+		}
+	}
+
+	new_entry->secondary_entries_count = entry_count + 1;
+	new_entry->last_clear_ts = last_clear_ts;
+
+	return node;
+}
+
+
+/*
+ * This function removes an entry from the ebtree. If the entry was a duplicate
+ * (in case of Vary), it updates the secondary entry counter in another
+ * duplicate entry (the last entry of the dup list).
+ *
+ * This function must be called under a cache write lock.
+ */
+static void delete_entry(struct cache_entry *del_entry)
+{
+	struct eb32_node *prev = NULL, *next = NULL;
+	struct cache_entry *entry = NULL;
+	struct eb32_node *last = NULL;
+
+	/* The entry might have been removed from the cache before. In such a
+	 * case calling eb32_next_dup would crash. */
+	if (del_entry->secondary_key_signature && del_entry->eb.key != 0) {
+		next = &del_entry->eb;
+
+		/* Look for last entry of the duplicates list. */
+		while ((next = eb32_next_dup(next))) {
+			last = next;
+		}
+
+		if (last) {
+			entry = container_of(last, struct cache_entry, eb);
+			--entry->secondary_entries_count;
+		}
+		else {
+			/* The current entry is the last one, look for the
+			 * previous one to update its counter. */
+			prev = eb32_prev_dup(&del_entry->eb);
+			if (prev) {
+				entry = container_of(prev, struct cache_entry, eb);
+				entry->secondary_entries_count = del_entry->secondary_entries_count - 1;
+			}
+		}
+	}
+	eb32_delete(&del_entry->eb);
+	del_entry->eb.key = 0;
+}
+
+
+static inline struct shared_context *shctx_ptr(struct cache *cache)
+{
+	return (struct shared_context *)((unsigned char *)cache -  offsetof(struct shared_context, data));
+}
+
+static inline struct shared_block *block_ptr(struct cache_entry *entry)
+{
+	return (struct shared_block *)((unsigned char *)entry - offsetof(struct shared_block, data));
+}
+
+
+
+static int
+cache_store_init(struct proxy *px, struct flt_conf *fconf)
+{
+	fconf->flags |= FLT_CFG_FL_HTX;
+	return 0;
+}
+
+static void
+cache_store_deinit(struct proxy *px, struct flt_conf *fconf)
+{
+	struct cache_flt_conf *cconf = fconf->conf;
+
+	if (!(cconf->flags & CACHE_FLT_INIT))
+		free(cconf->c.name);
+	free(cconf);
+}
+
+static int
+cache_store_check(struct proxy *px, struct flt_conf *fconf)
+{
+	struct cache_flt_conf *cconf = fconf->conf;
+	struct flt_conf *f;
+	struct cache *cache;
+	int comp = 0;
+
+	/* Find the cache corresponding to the name in the filter config.  The
+	*  cache will not be referenced now in the filter config because it is
+	*  not fully allocated. This step will be performed during the cache
+	*  post_check.
+	*/
+	list_for_each_entry(cache, &caches_config, list) {
+		if (strcmp(cache->id, cconf->c.name) == 0)
+			goto found;
+	}
+
+	ha_alert("config: %s '%s': unable to find the cache '%s' referenced by the filter 'cache'.\n",
+		 proxy_type_str(px), px->id, (char *)cconf->c.name);
+	return 1;
+
+  found:
+	/* Here <cache> points on the cache the filter must use and <cconf>
+	 * points on the cache filter configuration. */
+
+	/* Check all filters for proxy <px> to know if the compression is
+	 * enabled and if it is after the cache. When the compression is before
+	 * the cache, an error is returned. Also check if the cache filter must
+	 * be explicitly declaired or not. */
+	list_for_each_entry(f, &px->filter_configs, list) {
+		if (f == fconf) {
+			/* The compression filter must be evaluated after the cache. */
+			if (comp) {
+				ha_alert("config: %s '%s': unable to enable the compression filter before "
+					 "the cache '%s'.\n", proxy_type_str(px), px->id, cache->id);
+				return 1;
+			}
+		}
+		else if (f->id == http_comp_flt_id)
+			comp = 1;
+		else if (f->id == fcgi_flt_id)
+			continue;
+		else if ((f->id != fconf->id) && (cconf->flags & CACHE_FLT_F_IMPLICIT_DECL)) {
+			/* Implicit declaration is only allowed with the
+			 * compression and fcgi. For other filters, an implicit
+			 * declaration is required. */
+			ha_alert("config: %s '%s': require an explicit filter declaration "
+				 "to use the cache '%s'.\n", proxy_type_str(px), px->id, cache->id);
+			return 1;
+		}
+
+	}
+	return 0;
+}
+
+static int
+cache_store_strm_init(struct stream *s, struct filter *filter)
+{
+	struct cache_st *st;
+
+	st = pool_alloc(pool_head_cache_st);
+	if (st == NULL)
+		return -1;
+
+	st->first_block = NULL;
+	filter->ctx     = st;
+
+	/* Register post-analyzer on AN_RES_WAIT_HTTP */
+	filter->post_analyzers |= AN_RES_WAIT_HTTP;
+	return 1;
+}
+
+static void
+cache_store_strm_deinit(struct stream *s, struct filter *filter)
+{
+	struct cache_st *st = filter->ctx;
+	struct cache_flt_conf *cconf = FLT_CONF(filter);
+	struct cache *cache = cconf->c.cache;
+	struct shared_context *shctx = shctx_ptr(cache);
+
+	/* Everything should be released in the http_end filter, but we need to do it
+	 * there too, in case of errors */
+	if (st && st->first_block) {
+		struct cache_entry *object = (struct cache_entry *)st->first_block->data;
+		if (!object->complete) {
+			/* The stream was closed but the 'complete' flag was not
+			 * set which means that cache_store_http_end was not
+			 * called. The stream must have been closed before we
+			 * could store the full answer in the cache.
+			 */
+			release_entry_unlocked(&cache->trees[object->eb.key % CACHE_TREE_NUM], object);
+		}
+		shctx_wrlock(shctx);
+		shctx_row_reattach(shctx, st->first_block);
+		shctx_wrunlock(shctx);
+	}
+	if (st) {
+		pool_free(pool_head_cache_st, st);
+		filter->ctx = NULL;
+	}
+}
+
+static int
+cache_store_post_analyze(struct stream *s, struct filter *filter, struct channel *chn,
+			 unsigned an_bit)
+{
+	struct http_txn *txn = s->txn;
+	struct http_msg *msg = &txn->rsp;
+	struct cache_st *st = filter->ctx;
+
+	if (an_bit != AN_RES_WAIT_HTTP)
+		goto end;
+
+	/* Here we need to check if any compression filter precedes the cache
+	 * filter. This is only possible when the compression is configured in
+	 * the frontend while the cache filter is configured on the
+	 * backend. This case cannot be detected during HAProxy startup. So in
+	 * such cases, the cache is disabled.
+	 */
+	if (st && (msg->flags & HTTP_MSGF_COMPRESSING)) {
+		pool_free(pool_head_cache_st, st);
+		filter->ctx = NULL;
+	}
+
+  end:
+	return 1;
+}
+
+static int
+cache_store_http_headers(struct stream *s, struct filter *filter, struct http_msg *msg)
+{
+	struct cache_st *st = filter->ctx;
+
+	if (!(msg->chn->flags & CF_ISRESP) || !st)
+		return 1;
+
+	if (st->first_block)
+		register_data_filter(s, msg->chn, filter);
+	return 1;
+}
+
+static inline void disable_cache_entry(struct cache_st *st,
+                                       struct filter *filter, struct shared_context *shctx)
+{
+	struct cache_entry *object;
+	struct cache *cache = (struct cache*)shctx->data;
+
+	object = (struct cache_entry *)st->first_block->data;
+	filter->ctx = NULL; /* disable cache  */
+	release_entry_unlocked(&cache->trees[object->eb.key % CACHE_TREE_NUM], object);
+	shctx_wrlock(shctx);
+	shctx_row_reattach(shctx, st->first_block);
+	shctx_wrunlock(shctx);
+	pool_free(pool_head_cache_st, st);
+}
+
+static int
+cache_store_http_payload(struct stream *s, struct filter *filter, struct http_msg *msg,
+			 unsigned int offset, unsigned int len)
+{
+	struct cache_flt_conf *cconf = FLT_CONF(filter);
+	struct shared_context *shctx = shctx_ptr(cconf->c.cache);
+	struct cache_st *st = filter->ctx;
+	struct htx *htx = htxbuf(&msg->chn->buf);
+	struct htx_blk *blk;
+	struct shared_block *fb;
+	struct htx_ret htxret;
+	unsigned int orig_len, to_forward;
+	int ret;
+
+	if (!len)
+		return len;
+
+	if (!st->first_block) {
+		unregister_data_filter(s, msg->chn, filter);
+		return len;
+	}
+
+	chunk_reset(&trash);
+	orig_len = len;
+	to_forward = 0;
+
+	htxret = htx_find_offset(htx, offset);
+	blk = htxret.blk;
+	offset = htxret.ret;
+	for (; blk && len; blk = htx_get_next_blk(htx, blk)) {
+		enum htx_blk_type type = htx_get_blk_type(blk);
+		uint32_t info, sz = htx_get_blksz(blk);
+		struct ist v;
+
+		switch (type) {
+			case HTX_BLK_UNUSED:
+				break;
+
+			case HTX_BLK_DATA:
+				v = htx_get_blk_value(htx, blk);
+				v = istadv(v, offset);
+				v = isttrim(v, len);
+
+				info = (type << 28) + v.len;
+				chunk_memcat(&trash, (char *)&info, sizeof(info));
+				chunk_istcat(&trash, v);
+				to_forward += v.len;
+				len -= v.len;
+				break;
+
+			default:
+				/* Here offset must always be 0 because only
+				 * DATA blocks can be partially transferred. */
+				if (offset)
+					goto no_cache;
+				if (sz > len)
+					goto end;
+
+				chunk_memcat(&trash, (char *)&blk->info, sizeof(blk->info));
+				chunk_memcat(&trash, htx_get_blk_ptr(htx, blk), sz);
+				to_forward += sz;
+				len -= sz;
+				break;
+		}
+
+		offset = 0;
+	}
+
+  end:
+
+	fb = shctx_row_reserve_hot(shctx, st->first_block, trash.data);
+	if (!fb) {
+		goto no_cache;
+	}
+
+	ret = shctx_row_data_append(shctx, st->first_block,
+				    (unsigned char *)b_head(&trash), b_data(&trash));
+	if (ret < 0)
+		goto no_cache;
+
+	return to_forward;
+
+  no_cache:
+	disable_cache_entry(st, filter, shctx);
+	unregister_data_filter(s, msg->chn, filter);
+	return orig_len;
+}
+
+static int
+cache_store_http_end(struct stream *s, struct filter *filter,
+                     struct http_msg *msg)
+{
+	struct cache_st *st = filter->ctx;
+	struct cache_flt_conf *cconf = FLT_CONF(filter);
+	struct cache *cache = cconf->c.cache;
+	struct shared_context *shctx = shctx_ptr(cache);
+	struct cache_entry *object;
+
+	if (!(msg->chn->flags & CF_ISRESP))
+		return 1;
+
+	if (st && st->first_block) {
+
+		object = (struct cache_entry *)st->first_block->data;
+
+		shctx_wrlock(shctx);
+		/* The whole payload was cached, the entry can now be used. */
+		object->complete = 1;
+		/* remove from the hotlist */
+		shctx_row_reattach(shctx, st->first_block);
+		shctx_wrunlock(shctx);
+
+	}
+	if (st) {
+		pool_free(pool_head_cache_st, st);
+		filter->ctx = NULL;
+	}
+
+	return 1;
+}
+
+ /*
+  * This intends to be used when checking HTTP headers for some
+  * word=value directive. Return a pointer to the first character of value, if
+  * the word was not found or if there wasn't any value assigned to it return NULL
+  */
+char *directive_value(const char *sample, int slen, const char *word, int wlen)
+{
+	int st = 0;
+
+	if (slen < wlen)
+		return 0;
+
+	while (wlen) {
+		char c = *sample ^ *word;
+		if (c && c != ('A' ^ 'a'))
+			return NULL;
+		sample++;
+		word++;
+		slen--;
+		wlen--;
+	}
+
+	while (slen) {
+		if (st == 0) {
+			if (*sample != '=')
+				return NULL;
+			sample++;
+			slen--;
+			st = 1;
+			continue;
+		} else {
+			return (char *)sample;
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * Return the maxage in seconds of an HTTP response.
+ * The returned value will always take the cache's configuration into account
+ * (cache->maxage) but the actual max age of the response will be set in the
+ * true_maxage parameter. It will be used to determine if a response is already
+ * stale or not.
+ * Compute the maxage using either:
+ *  - the assigned max-age of the cache
+ *  - the s-maxage directive
+ *  - the max-age directive
+ *  - (Expires - Data) headers
+ *  - the default-max-age of the cache
+ *
+ */
+int http_calc_maxage(struct stream *s, struct cache *cache, int *true_maxage)
+{
+	struct htx *htx = htxbuf(&s->res.buf);
+	struct http_hdr_ctx ctx = { .blk = NULL };
+	long smaxage = -1;
+	long maxage = -1;
+	int expires = -1;
+	struct tm tm = {};
+	time_t expires_val = 0;
+	char *endptr = NULL;
+	int offset = 0;
+
+	/* The Cache-Control max-age and s-maxage directives should be followed by
+	 * a positive numerical value (see RFC 7234#5.2.1.1). According to the
+	 * specs, a sender "should not" generate a quoted-string value but we will
+	 * still accept this format since it isn't strictly forbidden. */
+	while (http_find_header(htx, ist("cache-control"), &ctx, 0)) {
+		char *value;
+
+		value = directive_value(ctx.value.ptr, ctx.value.len, "s-maxage", 8);
+		if (value) {
+			struct buffer *chk = get_trash_chunk();
+
+			chunk_memcat(chk, value, ctx.value.len - 8 + 1);
+			chunk_memcat(chk, "", 1);
+			offset = (*chk->area == '"') ? 1 : 0;
+			smaxage = strtol(chk->area + offset, &endptr, 10);
+			if (unlikely(smaxage < 0 || endptr == chk->area + offset))
+				return -1;
+		}
+
+		value = directive_value(ctx.value.ptr, ctx.value.len, "max-age", 7);
+		if (value) {
+			struct buffer *chk = get_trash_chunk();
+
+			chunk_memcat(chk, value, ctx.value.len - 7 + 1);
+			chunk_memcat(chk, "", 1);
+			offset = (*chk->area == '"') ? 1 : 0;
+			maxage = strtol(chk->area + offset, &endptr, 10);
+			if (unlikely(maxage < 0 || endptr == chk->area + offset))
+				return -1;
+		}
+	}
+
+	/* Look for Expires header if no s-maxage or max-age Cache-Control data
+	 * was found. */
+	if (maxage == -1 && smaxage == -1) {
+		ctx.blk = NULL;
+		if (http_find_header(htx, ist("expires"), &ctx, 1)) {
+			if (parse_http_date(istptr(ctx.value), istlen(ctx.value), &tm)) {
+				expires_val = my_timegm(&tm);
+				/* A request having an expiring date earlier
+				 * than the current date should be considered as
+				 * stale. */
+				expires = (expires_val >= date.tv_sec) ?
+					(expires_val - date.tv_sec) : 0;
+			}
+			else {
+				/* Following RFC 7234#5.3, an invalid date
+				 * format must be treated as a date in the past
+				 * so the cache entry must be seen as already
+				 * expired. */
+				expires = 0;
+			}
+		}
+	}
+
+
+	if (smaxage > 0) {
+		if (true_maxage)
+			*true_maxage = smaxage;
+		return MIN(smaxage, cache->maxage);
+	}
+
+	if (maxage > 0) {
+		if (true_maxage)
+			*true_maxage = maxage;
+		return MIN(maxage, cache->maxage);
+	}
+
+	if (expires >= 0) {
+		if (true_maxage)
+			*true_maxage = expires;
+		return MIN(expires, cache->maxage);
+	}
+
+	return cache->maxage;
+
+}
+
+
+static void cache_free_blocks(struct shared_block *first, void *data)
+{
+	struct cache_entry *object = (struct cache_entry *)first->data;
+	struct cache *cache = (struct cache *)data;
+	struct cache_tree *cache_tree;
+
+	if (object->eb.key) {
+		object->complete = 0;
+		cache_tree = &cache->trees[object->eb.key % CACHE_TREE_NUM];
+		retain_entry(object);
+		HA_SPIN_LOCK(CACHE_LOCK, &cache_tree->cleanup_lock);
+		LIST_INSERT(&cache_tree->cleanup_list, &object->cleanup_list);
+		HA_SPIN_UNLOCK(CACHE_LOCK, &cache_tree->cleanup_lock);
+	}
+}
+
+static void cache_reserve_finish(struct shared_context *shctx)
+{
+	struct cache_entry *object, *back;
+	struct cache *cache = (struct cache *)shctx->data;
+	struct cache_tree *cache_tree;
+	int cache_tree_idx = 0;
+
+	for (; cache_tree_idx < CACHE_TREE_NUM; ++cache_tree_idx) {
+		cache_tree = &cache->trees[cache_tree_idx];
+
+		cache_wrlock(cache_tree);
+		HA_SPIN_LOCK(CACHE_LOCK, &cache_tree->cleanup_lock);
+
+		list_for_each_entry_safe(object, back, &cache_tree->cleanup_list, cleanup_list) {
+			LIST_DELETE(&object->cleanup_list);
+			/*
+			 * At this point we locked the cache tree in write mode
+			 * so no new thread could retain the current entry
+			 * because the only two places where it can happen is in
+			 * the cache_use case which is under cache_rdlock and
+			 * the reserve_hot case which would require the
+			 * corresponding block to still be in the avail list,
+			 * which is impossible (we reserved it for a thread and
+			 * took it out of the avail list already). The only two
+			 * references are then the default one (upon cache_entry
+			 * creation) and the one in this cleanup list.
+			 */
+			BUG_ON(object->refcount > 2);
+			delete_entry(object);
+		}
+
+		HA_SPIN_UNLOCK(CACHE_LOCK, &cache_tree->cleanup_lock);
+		cache_wrunlock(cache_tree);
+	}
+}
+
+
+/* As per RFC 7234#4.3.2, in case of "If-Modified-Since" conditional request, the
+ * date value should be compared to a date determined by in a previous response (for
+ * the same entity). This date could either be the "Last-Modified" value, or the "Date"
+ * value of the response's reception time (by decreasing order of priority). */
+static time_t get_last_modified_time(struct htx *htx)
+{
+	time_t last_modified = 0;
+	struct http_hdr_ctx ctx = { .blk = NULL };
+	struct tm tm = {};
+
+	if (http_find_header(htx, ist("last-modified"), &ctx, 1)) {
+		if (parse_http_date(istptr(ctx.value), istlen(ctx.value), &tm)) {
+			last_modified = my_timegm(&tm);
+		}
+	}
+
+	if (!last_modified) {
+		ctx.blk = NULL;
+		if (http_find_header(htx, ist("date"), &ctx, 1)) {
+			if (parse_http_date(istptr(ctx.value), istlen(ctx.value), &tm)) {
+				last_modified = my_timegm(&tm);
+			}
+		}
+	}
+
+	/* Fallback on the current time if no "Last-Modified" or "Date" header
+	 * was found. */
+	if (!last_modified)
+		last_modified = date.tv_sec;
+
+	return last_modified;
+}
+
+/*
+ * Checks the vary header's value. The headers on which vary should be applied
+ * must be explicitly supported in the vary_information array (see cache.c). If
+ * any other header is mentioned, we won't store the response.
+ * Returns 1 if Vary-based storage can work, 0 otherwise.
+ */
+static int http_check_vary_header(struct htx *htx, unsigned int *vary_signature)
+{
+	unsigned int vary_idx;
+	unsigned int vary_info_count;
+	const struct vary_hashing_information *vary_info;
+	struct http_hdr_ctx ctx = { .blk = NULL };
+
+	int retval = 1;
+
+	*vary_signature = 0;
+
+	vary_info_count = sizeof(vary_information)/sizeof(*vary_information);
+	while (retval && http_find_header(htx, ist("Vary"), &ctx, 0)) {
+		for (vary_idx = 0; vary_idx < vary_info_count; ++vary_idx) {
+			vary_info = &vary_information[vary_idx];
+			if (isteqi(ctx.value, vary_info->hdr_name)) {
+				*vary_signature |= vary_info->value;
+				break;
+			}
+		}
+		retval = (vary_idx < vary_info_count);
+	}
+
+	return retval;
+}
+
+
+/*
+ * Look for the accept-encoding part of the secondary_key and replace the
+ * encoding bitmap part of the hash with the actual encoding of the response,
+ * extracted from the content-encoding header value.
+ * Responses that have an unknown encoding will not be cached if they also
+ * "vary" on the accept-encoding value.
+ * Returns 0 if we found a known encoding in the response, -1 otherwise.
+ */
+static int set_secondary_key_encoding(struct htx *htx, char *secondary_key)
+{
+	unsigned int resp_encoding_bitmap = 0;
+	const struct vary_hashing_information *info = vary_information;
+	unsigned int offset = 0;
+	unsigned int count = 0;
+	unsigned int hash_info_count = sizeof(vary_information)/sizeof(*vary_information);
+	unsigned int encoding_value;
+	struct http_hdr_ctx ctx = { .blk = NULL };
+
+	/* Look for the accept-encoding part of the secondary_key. */
+	while (count < hash_info_count && info->value != VARY_ACCEPT_ENCODING) {
+		offset += info->hash_length;
+		++info;
+		++count;
+	}
+
+	if (count == hash_info_count)
+		return -1;
+
+	while (http_find_header(htx, ist("content-encoding"), &ctx, 0)) {
+		if (parse_encoding_value(ctx.value, &encoding_value, NULL))
+			return -1; /* Do not store responses with an unknown encoding */
+		resp_encoding_bitmap |= encoding_value;
+	}
+
+	if (!resp_encoding_bitmap)
+		resp_encoding_bitmap |= VARY_ENCODING_IDENTITY;
+
+	/* Rewrite the bitmap part of the hash with the new bitmap that only
+	 * corresponds the the response's encoding. */
+	write_u32(secondary_key + offset, resp_encoding_bitmap);
+
+	return 0;
+}
+
+
+/*
+ * This function will store the headers of the response in a buffer and then
+ * register a filter to store the data
+ */
+enum act_return http_action_store_cache(struct act_rule *rule, struct proxy *px,
+					struct session *sess, struct stream *s, int flags)
+{
+	int effective_maxage = 0;
+	int true_maxage = 0;
+	struct http_txn *txn = s->txn;
+	struct http_msg *msg = &txn->rsp;
+	struct filter *filter;
+	struct shared_block *first = NULL;
+	struct cache_flt_conf *cconf = rule->arg.act.p[0];
+	struct cache *cache = cconf->c.cache;
+	struct shared_context *shctx = shctx_ptr(cache);
+	struct cache_st *cache_ctx = NULL;
+	struct cache_entry *object, *old;
+	unsigned int key = read_u32(txn->cache_hash);
+	struct htx *htx;
+	struct http_hdr_ctx ctx;
+	size_t hdrs_len = 0;
+	int32_t pos;
+	unsigned int vary_signature = 0;
+	struct cache_tree *cache_tree = NULL;
+
+	/* Don't cache if the response came from a cache */
+	if ((obj_type(s->target) == OBJ_TYPE_APPLET) &&
+	    s->target == &http_cache_applet.obj_type) {
+		goto out;
+	}
+
+	/* cache only HTTP/1.1 */
+	if (!(txn->req.flags & HTTP_MSGF_VER_11))
+		goto out;
+
+	cache_tree = get_cache_tree_from_hash(cache, read_u32(txn->cache_hash));
+
+	/* cache only GET method */
+	if (txn->meth != HTTP_METH_GET) {
+		/* In case of successful unsafe method on a stored resource, the
+		 * cached entry must be invalidated (see RFC7234#4.4).
+		 * A "non-error response" is one with a 2xx (Successful) or 3xx
+		 * (Redirection) status code. */
+		if (txn->status >= 200 && txn->status < 400) {
+			switch (txn->meth) {
+			case HTTP_METH_OPTIONS:
+			case HTTP_METH_GET:
+			case HTTP_METH_HEAD:
+			case HTTP_METH_TRACE:
+				break;
+
+			default: /* Any unsafe method */
+				/* Discard any corresponding entry in case of successful
+				 * unsafe request (such as PUT, POST or DELETE). */
+				cache_wrlock(cache_tree);
+
+				old = get_entry(cache_tree, txn->cache_hash, 1);
+				if (old)
+					release_entry_locked(cache_tree, old);
+				cache_wrunlock(cache_tree);
+			}
+		}
+		goto out;
+	}
+
+	/* cache key was not computed */
+	if (!key)
+		goto out;
+
+	/* cache only 200 status code */
+	if (txn->status != 200)
+		goto out;
+
+	/* Find the corresponding filter instance for the current stream */
+	list_for_each_entry(filter, &s->strm_flt.filters, list) {
+		if (FLT_ID(filter) == cache_store_flt_id  && FLT_CONF(filter) == cconf) {
+			/* No filter ctx, don't cache anything */
+			if (!filter->ctx)
+				goto out;
+			cache_ctx = filter->ctx;
+			break;
+		}
+	}
+
+	/* from there, cache_ctx is always defined */
+	htx = htxbuf(&s->res.buf);
+
+	/* Do not cache too big objects. */
+	if ((msg->flags & HTTP_MSGF_CNT_LEN) && shctx->max_obj_size > 0 &&
+	    htx->data + htx->extra > shctx->max_obj_size)
+		goto out;
+
+	/* Only a subset of headers are supported in our Vary implementation. If
+	 * any other header is present in the Vary header value, we won't be
+	 * able to use the cache. Likewise, if Vary header support is disabled,
+	 * avoid caching responses that contain such a header. */
+	ctx.blk = NULL;
+	if (cache->vary_processing_enabled) {
+		if (!http_check_vary_header(htx, &vary_signature))
+			goto out;
+		if (vary_signature) {
+			/* If something went wrong during the secondary key
+			 * building, do not store the response. */
+			if (!(txn->flags & TX_CACHE_HAS_SEC_KEY))
+				goto out;
+			http_request_reduce_secondary_key(vary_signature, txn->cache_secondary_hash);
+		}
+	}
+	else if (http_find_header(htx, ist("Vary"), &ctx, 0)) {
+		goto out;
+	}
+
+	http_check_response_for_cacheability(s, &s->res);
+
+	if (!(txn->flags & TX_CACHEABLE) || !(txn->flags & TX_CACHE_COOK))
+		goto out;
+
+	cache_wrlock(cache_tree);
+	old = get_entry(cache_tree, txn->cache_hash, 1);
+	if (old) {
+		if (vary_signature)
+			old = get_secondary_entry(cache_tree, old,
+			                          txn->cache_secondary_hash, 1);
+		if (old) {
+			if (!old->complete) {
+				/* An entry with the same primary key is already being
+				 * created, we should not try to store the current
+				 * response because it will waste space in the cache. */
+				cache_wrunlock(cache_tree);
+				goto out;
+			}
+			release_entry_locked(cache_tree, old);
+		}
+	}
+	cache_wrunlock(cache_tree);
+
+	first = shctx_row_reserve_hot(shctx, NULL, sizeof(struct cache_entry));
+	if (!first) {
+		goto out;
+	}
+
+	/* the received memory is not initialized, we need at least to mark
+	 * the object as not indexed yet.
+	 */
+	object = (struct cache_entry *)first->data;
+	memset(object, 0, sizeof(*object));
+	object->eb.key = key;
+	object->secondary_key_signature = vary_signature;
+	/* We need to temporarily set a valid expiring time until the actual one
+	 * is set by the end of this function (in case of concurrent accesses to
+	 * the same resource). This way the second access will find an existing
+	 * but not yet usable entry in the tree and will avoid storing its data. */
+	object->expire = date.tv_sec + 2;
+
+	memcpy(object->hash, txn->cache_hash, sizeof(object->hash));
+	if (vary_signature)
+		memcpy(object->secondary_key, txn->cache_secondary_hash, HTTP_CACHE_SEC_KEY_LEN);
+
+	cache_wrlock(cache_tree);
+	/* Insert the entry in the tree even if the payload is not cached yet. */
+	if (insert_entry(cache, cache_tree, object) != &object->eb) {
+		object->eb.key = 0;
+		cache_wrunlock(cache_tree);
+		goto out;
+	}
+	cache_wrunlock(cache_tree);
+
+	/* reserve space for the cache_entry structure */
+	first->len = sizeof(struct cache_entry);
+	first->last_append = NULL;
+
+	/* Determine the entry's maximum age (taking into account the cache's
+	 * configuration) as well as the response's explicit max age (extracted
+	 * from cache-control directives or the expires header). */
+	effective_maxage = http_calc_maxage(s, cache, &true_maxage);
+
+	ctx.blk = NULL;
+	if (http_find_header(htx, ist("Age"), &ctx, 0)) {
+		long long hdr_age;
+		if (!strl2llrc(ctx.value.ptr, ctx.value.len, &hdr_age) && hdr_age > 0) {
+			if (unlikely(hdr_age > CACHE_ENTRY_MAX_AGE))
+				hdr_age = CACHE_ENTRY_MAX_AGE;
+			/* A response with an Age value greater than its
+			 * announced max age is stale and should not be stored. */
+			object->age = hdr_age;
+			if (unlikely(object->age > true_maxage))
+				goto out;
+		}
+		else
+			goto out;
+		http_remove_header(htx, &ctx);
+	}
+
+	/* Build a last-modified time that will be stored in the cache_entry and
+	 * compared to a future If-Modified-Since client header. */
+	object->last_modified = get_last_modified_time(htx);
+
+	chunk_reset(&trash);
+	for (pos = htx_get_first(htx); pos != -1; pos = htx_get_next(htx, pos)) {
+		struct htx_blk *blk = htx_get_blk(htx, pos);
+		enum htx_blk_type type = htx_get_blk_type(blk);
+		uint32_t sz = htx_get_blksz(blk);
+
+		hdrs_len += sizeof(*blk) + sz;
+		chunk_memcat(&trash, (char *)&blk->info, sizeof(blk->info));
+		chunk_memcat(&trash, htx_get_blk_ptr(htx, blk), sz);
+
+		/* Look for optional ETag header.
+		 * We need to store the offset of the ETag value in order for
+		 * future conditional requests to be able to perform ETag
+		 * comparisons. */
+		if (type == HTX_BLK_HDR) {
+			struct ist header_name = htx_get_blk_name(htx, blk);
+			if (isteq(header_name, ist("etag"))) {
+				object->etag_length = sz - istlen(header_name);
+				object->etag_offset = sizeof(struct cache_entry) + b_data(&trash) - sz + istlen(header_name);
+			}
+		}
+		if (type == HTX_BLK_EOH)
+			break;
+	}
+
+	/* Do not cache objects if the headers are too big. */
+	if (hdrs_len > htx->size - global.tune.maxrewrite)
+		goto out;
+
+	/* If the response has a secondary_key, fill its key part related to
+	 * encodings with the actual encoding of the response. This way any
+	 * subsequent request having the same primary key will have its accepted
+	 * encodings tested upon the cached response's one.
+	 * We will not cache a response that has an unknown encoding (not
+	 * explicitly supported in parse_encoding_value function). */
+	if (cache->vary_processing_enabled && vary_signature)
+		if (set_secondary_key_encoding(htx, object->secondary_key))
+		    goto out;
+
+	if (!shctx_row_reserve_hot(shctx, first, trash.data)) {
+		goto out;
+	}
+
+	/* cache the headers in a http action because it allows to chose what
+	 * to cache, for example you might want to cache a response before
+	 * modifying some HTTP headers, or on the contrary after modifying
+	 * those headers.
+	 */
+	/* does not need to be locked because it's in the "hot" list,
+	 * copy the headers */
+	if (shctx_row_data_append(shctx, first, (unsigned char *)trash.area, trash.data) < 0)
+		goto out;
+
+	/* register the buffer in the filter ctx for filling it with data*/
+	if (cache_ctx) {
+		cache_ctx->first_block = first;
+		LIST_INIT(&cache_ctx->detached_head);
+		/* store latest value and expiration time */
+		object->latest_validation = date.tv_sec;
+		object->expire = date.tv_sec + effective_maxage;
+		return ACT_RET_CONT;
+	}
+
+out:
+	/* if does not cache */
+	if (first) {
+		first->len = 0;
+		if (object->eb.key) {
+			release_entry_unlocked(cache_tree, object);
+		}
+		shctx_wrlock(shctx);
+		shctx_row_reattach(shctx, first);
+		shctx_wrunlock(shctx);
+	}
+
+	return ACT_RET_CONT;
+}
+
+#define 	HTX_CACHE_INIT   0  /* Initial state. */
+#define 	HTX_CACHE_HEADER 1  /* Cache entry headers forwarding */
+#define 	HTX_CACHE_DATA   2  /* Cache entry data forwarding */
+#define 	HTX_CACHE_EOM    3  /* Cache entry completely forwarded. Finish the HTX message */
+#define 	HTX_CACHE_END    4  /* Cache entry treatment terminated */
+
+static void http_cache_applet_release(struct appctx *appctx)
+{
+	struct cache_appctx *ctx = appctx->svcctx;
+	struct cache_flt_conf *cconf = appctx->rule->arg.act.p[0];
+	struct cache_entry *cache_ptr = ctx->entry;
+	struct cache *cache = cconf->c.cache;
+	struct shared_context *shctx = shctx_ptr(cache);
+	struct shared_block *first = block_ptr(cache_ptr);
+
+	release_entry(ctx->cache_tree, cache_ptr, 1);
+
+	shctx_wrlock(shctx);
+	shctx_row_reattach(shctx, first);
+	shctx_wrunlock(shctx);
+}
+
+
+static unsigned int htx_cache_dump_blk(struct appctx *appctx, struct htx *htx, enum htx_blk_type type,
+				       uint32_t info, struct shared_block *shblk, unsigned int offset)
+{
+	struct cache_appctx *ctx = appctx->svcctx;
+	struct cache_flt_conf *cconf = appctx->rule->arg.act.p[0];
+	struct shared_context *shctx = shctx_ptr(cconf->c.cache);
+	struct htx_blk *blk;
+	char *ptr;
+	unsigned int max, total;
+	uint32_t blksz;
+
+	max = htx_get_max_blksz(htx,
+				channel_htx_recv_max(sc_ic(appctx_sc(appctx)), htx));
+	if (!max)
+		return 0;
+	blksz = ((type == HTX_BLK_HDR || type == HTX_BLK_TLR)
+		 ? (info & 0xff) + ((info >> 8) & 0xfffff)
+		 : info & 0xfffffff);
+	if (blksz > max)
+		return 0;
+
+	blk = htx_add_blk(htx, type, blksz);
+	if (!blk)
+		return 0;
+
+	blk->info = info;
+	total = 4;
+	ptr = htx_get_blk_ptr(htx, blk);
+	while (blksz) {
+		max = MIN(blksz, shctx->block_size - offset);
+		memcpy(ptr, (const char *)shblk->data + offset, max);
+		offset += max;
+		blksz  -= max;
+		total  += max;
+		ptr    += max;
+		if (blksz || offset == shctx->block_size) {
+			shblk = LIST_NEXT(&shblk->list, typeof(shblk), list);
+			offset = 0;
+		}
+	}
+	ctx->offset = offset;
+	ctx->next   = shblk;
+	ctx->sent  += total;
+	return total;
+}
+
+static unsigned int htx_cache_dump_data_blk(struct appctx *appctx, struct htx *htx,
+					    uint32_t info, struct shared_block *shblk, unsigned int offset)
+{
+	struct cache_appctx *ctx = appctx->svcctx;
+	struct cache_flt_conf *cconf = appctx->rule->arg.act.p[0];
+	struct shared_context *shctx = shctx_ptr(cconf->c.cache);
+	unsigned int max, total, rem_data;
+	uint32_t blksz;
+
+	max = htx_get_max_blksz(htx,
+				channel_htx_recv_max(sc_ic(appctx_sc(appctx)), htx));
+	if (!max)
+		return 0;
+
+	rem_data = 0;
+	if (ctx->rem_data) {
+		blksz = ctx->rem_data;
+		total = 0;
+	}
+	else {
+		blksz = (info & 0xfffffff);
+		total = 4;
+	}
+	if (blksz > max) {
+		rem_data = blksz - max;
+		blksz = max;
+	}
+
+	while (blksz) {
+		size_t sz;
+
+		max = MIN(blksz, shctx->block_size - offset);
+		sz  = htx_add_data(htx, ist2(shblk->data + offset, max));
+		offset += sz;
+		blksz  -= sz;
+		total  += sz;
+		if (sz < max)
+			break;
+		if (blksz || offset == shctx->block_size) {
+			shblk = LIST_NEXT(&shblk->list, typeof(shblk), list);
+			offset = 0;
+		}
+	}
+
+	ctx->offset   = offset;
+	ctx->next     = shblk;
+	ctx->sent    += total;
+	ctx->rem_data = rem_data + blksz;
+	return total;
+}
+
+static size_t htx_cache_dump_msg(struct appctx *appctx, struct htx *htx, unsigned int len,
+				 enum htx_blk_type mark)
+{
+	struct cache_appctx *ctx = appctx->svcctx;
+	struct cache_flt_conf *cconf = appctx->rule->arg.act.p[0];
+	struct shared_context *shctx = shctx_ptr(cconf->c.cache);
+	struct shared_block   *shblk;
+	unsigned int offset, sz;
+	unsigned int ret, total = 0;
+
+	while (len) {
+		enum htx_blk_type type;
+		uint32_t info;
+
+		shblk  = ctx->next;
+		offset = ctx->offset;
+		if (ctx->rem_data) {
+			type = HTX_BLK_DATA;
+			info = 0;
+			goto add_data_blk;
+		}
+
+		/* Get info of the next HTX block. May be split on 2 shblk */
+		sz = MIN(4, shctx->block_size - offset);
+		memcpy((char *)&info, (const char *)shblk->data + offset, sz);
+		offset += sz;
+		if (sz < 4) {
+			shblk = LIST_NEXT(&shblk->list, typeof(shblk), list);
+			memcpy(((char *)&info)+sz, (const char *)shblk->data, 4 - sz);
+			offset = (4 - sz);
+		}
+
+		/* Get payload of the next HTX block and insert it. */
+		type = (info >> 28);
+		if (type != HTX_BLK_DATA)
+			ret = htx_cache_dump_blk(appctx, htx, type, info, shblk, offset);
+		else {
+		  add_data_blk:
+			ret = htx_cache_dump_data_blk(appctx, htx, info, shblk, offset);
+		}
+
+		if (!ret)
+			break;
+		total += ret;
+		len   -= ret;
+
+		if (ctx->rem_data || type == mark)
+			break;
+	}
+
+	return total;
+}
+
+static int htx_cache_add_age_hdr(struct appctx *appctx, struct htx *htx)
+{
+	struct cache_appctx *ctx = appctx->svcctx;
+	struct cache_entry *cache_ptr = ctx->entry;
+	unsigned int age;
+	char *end;
+
+	chunk_reset(&trash);
+	age = MAX(0, (int)(date.tv_sec - cache_ptr->latest_validation)) + cache_ptr->age;
+	if (unlikely(age > CACHE_ENTRY_MAX_AGE))
+		age = CACHE_ENTRY_MAX_AGE;
+	end = ultoa_o(age, b_head(&trash), b_size(&trash));
+	b_set_data(&trash, end - b_head(&trash));
+	if (!http_add_header(htx, ist("Age"), ist2(b_head(&trash), b_data(&trash))))
+		return 0;
+	return 1;
+}
+
+static void http_cache_io_handler(struct appctx *appctx)
+{
+	struct cache_appctx *ctx = appctx->svcctx;
+	struct cache_entry *cache_ptr = ctx->entry;
+	struct shared_block *first = block_ptr(cache_ptr);
+	struct stconn *sc = appctx_sc(appctx);
+	struct channel *req = sc_oc(sc);
+	struct channel *res = sc_ic(sc);
+	struct htx *req_htx, *res_htx;
+	struct buffer *errmsg;
+	unsigned int len;
+	size_t ret, total = 0;
+
+	res_htx = htx_from_buf(&res->buf);
+	total = res_htx->data;
+
+	if (unlikely(se_fl_test(appctx->sedesc, (SE_FL_EOS|SE_FL_ERROR|SE_FL_SHR|SE_FL_SHW))))
+		goto out;
+
+	/* Check if the input buffer is available. */
+	if (!b_size(&res->buf)) {
+		sc_need_room(sc, 0);
+		goto out;
+	}
+
+	if (appctx->st0 == HTX_CACHE_INIT) {
+		ctx->next = block_ptr(cache_ptr);
+		ctx->offset = sizeof(*cache_ptr);
+		ctx->sent = 0;
+		ctx->rem_data = 0;
+		appctx->st0 = HTX_CACHE_HEADER;
+	}
+
+	if (appctx->st0 == HTX_CACHE_HEADER) {
+		/* Headers must be dump at once. Otherwise it is an error */
+		len = first->len - sizeof(*cache_ptr) - ctx->sent;
+		ret = htx_cache_dump_msg(appctx, res_htx, len, HTX_BLK_EOH);
+		if (!ret || (htx_get_tail_type(res_htx) != HTX_BLK_EOH) ||
+		    !htx_cache_add_age_hdr(appctx, res_htx))
+			goto error;
+
+		/* In case of a conditional request, we might want to send a
+		 * "304 Not Modified" response instead of the stored data. */
+		if (ctx->send_notmodified) {
+			if (!http_replace_res_status(res_htx, ist("304"), ist("Not Modified"))) {
+				/* If replacing the status code fails we need to send the full response. */
+				ctx->send_notmodified = 0;
+			}
+		}
+
+		/* Skip response body for HEAD requests or in case of "304 Not
+		 * Modified" response. */
+		if (__sc_strm(sc)->txn->meth == HTTP_METH_HEAD || ctx->send_notmodified)
+			appctx->st0 = HTX_CACHE_EOM;
+		else
+			appctx->st0 = HTX_CACHE_DATA;
+	}
+
+	if (appctx->st0 == HTX_CACHE_DATA) {
+		len = first->len - sizeof(*cache_ptr) - ctx->sent;
+		if (len) {
+			ret = htx_cache_dump_msg(appctx, res_htx, len, HTX_BLK_UNUSED);
+			if (ret < len) {
+				sc_need_room(sc, channel_htx_recv_max(res, res_htx) + 1);
+				goto out;
+			}
+		}
+		appctx->st0 = HTX_CACHE_EOM;
+	}
+
+	if (appctx->st0 == HTX_CACHE_EOM) {
+		 /* no more data are expected. */
+		res_htx->flags |= HTX_FL_EOM;
+		se_fl_set(appctx->sedesc, SE_FL_EOI);
+
+		appctx->st0 = HTX_CACHE_END;
+	}
+
+  end:
+	if (appctx->st0 == HTX_CACHE_END)
+		se_fl_set(appctx->sedesc, SE_FL_EOS);
+
+  out:
+	total = res_htx->data - total;
+	if (total)
+		channel_add_input(res, total);
+	htx_to_buf(res_htx, &res->buf);
+
+	/* eat the whole request */
+	if (co_data(req)) {
+		req_htx = htx_from_buf(&req->buf);
+		co_htx_skip(req, req_htx, co_data(req));
+		htx_to_buf(req_htx, &req->buf);
+	}
+	return;
+
+  error:
+	/* Sent and HTTP error 500 */
+	b_reset(&res->buf);
+	errmsg = &http_err_chunks[HTTP_ERR_500];
+	res->buf.data = b_data(errmsg);
+	memcpy(res->buf.area, b_head(errmsg), b_data(errmsg));
+	res_htx = htx_from_buf(&res->buf);
+
+	total = 0;
+	se_fl_set(appctx->sedesc, SE_FL_ERROR);
+	appctx->st0 = HTX_CACHE_END;
+	goto end;
+}
+
+
+static int parse_cache_rule(struct proxy *proxy, const char *name, struct act_rule *rule, char **err)
+{
+	struct flt_conf *fconf;
+	struct cache_flt_conf *cconf = NULL;
+
+	if (!*name || strcmp(name, "if") == 0 || strcmp(name, "unless") == 0) {
+		memprintf(err, "expects a cache name");
+		goto err;
+	}
+
+	/* check if a cache filter was already registered with this cache
+	 * name, if that's the case, must use it. */
+	list_for_each_entry(fconf, &proxy->filter_configs, list) {
+		if (fconf->id == cache_store_flt_id) {
+			cconf = fconf->conf;
+			if (cconf && strcmp((char *)cconf->c.name, name) == 0) {
+				rule->arg.act.p[0] = cconf;
+				return 1;
+			}
+		}
+	}
+
+	/* Create the filter cache config  */
+	cconf = calloc(1, sizeof(*cconf));
+	if (!cconf) {
+		memprintf(err, "out of memory\n");
+		goto err;
+	}
+	cconf->flags = CACHE_FLT_F_IMPLICIT_DECL;
+	cconf->c.name = strdup(name);
+	if (!cconf->c.name) {
+		memprintf(err, "out of memory\n");
+		goto err;
+	}
+
+	/* register a filter to fill the cache buffer */
+	fconf = calloc(1, sizeof(*fconf));
+	if (!fconf) {
+		memprintf(err, "out of memory\n");
+		goto err;
+	}
+	fconf->id = cache_store_flt_id;
+	fconf->conf = cconf;
+	fconf->ops  = &cache_ops;
+	LIST_APPEND(&proxy->filter_configs, &fconf->list);
+
+	rule->arg.act.p[0] = cconf;
+	return 1;
+
+  err:
+	free(cconf);
+	return 0;
+}
+
+enum act_parse_ret parse_cache_store(const char **args, int *orig_arg, struct proxy *proxy,
+                                          struct act_rule *rule, char **err)
+{
+	rule->action       = ACT_CUSTOM;
+	rule->action_ptr   = http_action_store_cache;
+
+	if (!parse_cache_rule(proxy, args[*orig_arg], rule, err))
+		return ACT_RET_PRS_ERR;
+
+	(*orig_arg)++;
+	return ACT_RET_PRS_OK;
+}
+
+/* This produces a sha1 hash of the concatenation of the HTTP method,
+ * the first occurrence of the Host header followed by the path component
+ * if it begins with a slash ('/'). */
+int sha1_hosturi(struct stream *s)
+{
+	struct http_txn *txn = s->txn;
+	struct htx *htx = htxbuf(&s->req.buf);
+	struct htx_sl *sl;
+	struct http_hdr_ctx ctx;
+	struct ist uri;
+	blk_SHA_CTX sha1_ctx;
+	struct buffer *trash;
+
+	trash = get_trash_chunk();
+	ctx.blk = NULL;
+
+	sl = http_get_stline(htx);
+	uri = htx_sl_req_uri(sl); // whole uri
+	if (!uri.len)
+		return 0;
+
+	/* In HTTP/1, most URIs are seen in origin form ('/path/to/resource'),
+	 * unless haproxy is deployed in front of an outbound cache. In HTTP/2,
+	 * URIs are almost always sent in absolute form with their scheme. In
+	 * this case, the scheme is almost always "https". In order to support
+	 * sharing of cache objects between H1 and H2, we'll hash the absolute
+	 * URI whenever known, or prepend "https://" + the Host header for
+	 * relative URIs. The difference will only appear on absolute HTTP/1
+	 * requests sent to an origin server, which practically is never met in
+	 * the real world so we don't care about the ability to share the same
+	 * key here.URIs are normalized from the absolute URI to an origin form as
+	 * well.
+	 */
+	if (!(sl->flags & HTX_SL_F_HAS_AUTHORITY)) {
+		chunk_istcat(trash, ist("https://"));
+		if (!http_find_header(htx, ist("Host"), &ctx, 0))
+			return 0;
+		chunk_istcat(trash, ctx.value);
+	}
+
+	chunk_istcat(trash, uri);
+
+	/* hash everything */
+	blk_SHA1_Init(&sha1_ctx);
+	blk_SHA1_Update(&sha1_ctx, trash->area, trash->data);
+	blk_SHA1_Final((unsigned char *)txn->cache_hash, &sha1_ctx);
+
+	return 1;
+}
+
+/* Looks for "If-None-Match" headers in the request and compares their value
+ * with the one that might have been stored in the cache_entry. If any of them
+ * matches, a "304 Not Modified" response should be sent instead of the cached
+ * data.
+ * Although unlikely in a GET/HEAD request, the "If-None-Match: *" syntax is
+ * valid and should receive a "304 Not Modified" response (RFC 7234#4.3.2).
+ *
+ * If no "If-None-Match" header was found, look for an "If-Modified-Since"
+ * header and compare its value (date) to the one stored in the cache_entry.
+ * If the request's date is later than the cached one, we also send a
+ * "304 Not Modified" response (see RFCs 7232#3.3 and 7234#4.3.2).
+ *
+ * Returns 1 if "304 Not Modified" should be sent, 0 otherwise.
+ */
+static int should_send_notmodified_response(struct cache *cache, struct htx *htx,
+                                            struct cache_entry *entry)
+{
+	int retval = 0;
+
+	struct http_hdr_ctx ctx = { .blk = NULL };
+	struct ist cache_entry_etag = IST_NULL;
+	struct buffer *etag_buffer = NULL;
+	int if_none_match_found = 0;
+
+	struct tm tm = {};
+	time_t if_modified_since = 0;
+
+	/* If we find a "If-None-Match" header in the request, rebuild the
+	 * cache_entry's ETag in order to perform comparisons.
+	 * There could be multiple "if-none-match" header lines. */
+	while (http_find_header(htx, ist("if-none-match"), &ctx, 0)) {
+		if_none_match_found = 1;
+
+		/* A '*' matches everything. */
+		if (isteq(ctx.value, ist("*")) != 0) {
+			retval = 1;
+			break;
+		}
+
+		/* No need to rebuild an etag if none was stored in the cache. */
+		if (entry->etag_length == 0)
+			break;
+
+		/* Rebuild the stored ETag. */
+		if (etag_buffer == NULL) {
+			etag_buffer = get_trash_chunk();
+
+			if (shctx_row_data_get(shctx_ptr(cache), block_ptr(entry),
+					       (unsigned char*)b_orig(etag_buffer),
+					       entry->etag_offset, entry->etag_length) == 0) {
+				cache_entry_etag = ist2(b_orig(etag_buffer), entry->etag_length);
+			} else {
+				/* We could not rebuild the ETag in one go, we
+				 * won't send a "304 Not Modified" response. */
+				break;
+			}
+		}
+
+		if (http_compare_etags(cache_entry_etag, ctx.value) == 1) {
+			retval = 1;
+			break;
+		}
+	}
+
+	/* If the request did not contain an "If-None-Match" header, we look for
+	 * an "If-Modified-Since" header (see RFC 7232#3.3). */
+	if (retval == 0 && if_none_match_found == 0) {
+		ctx.blk = NULL;
+		if (http_find_header(htx, ist("if-modified-since"), &ctx, 1)) {
+			if (parse_http_date(istptr(ctx.value), istlen(ctx.value), &tm)) {
+				if_modified_since = my_timegm(&tm);
+
+				/* We send a "304 Not Modified" response if the
+				 * entry's last modified date is earlier than
+				 * the one found in the "If-Modified-Since"
+				 * header. */
+				retval = (entry->last_modified <= if_modified_since);
+			}
+		}
+	}
+
+	return retval;
+}
+
+enum act_return http_action_req_cache_use(struct act_rule *rule, struct proxy *px,
+                                         struct session *sess, struct stream *s, int flags)
+{
+
+	struct http_txn *txn = s->txn;
+	struct cache_entry *res, *sec_entry = NULL;
+	struct cache_flt_conf *cconf = rule->arg.act.p[0];
+	struct cache *cache = cconf->c.cache;
+	struct shared_context *shctx = shctx_ptr(cache);
+	struct shared_block *entry_block;
+
+	struct cache_tree *cache_tree = NULL;
+
+	/* Ignore cache for HTTP/1.0 requests and for requests other than GET
+	 * and HEAD */
+	if (!(txn->req.flags & HTTP_MSGF_VER_11) ||
+	    (txn->meth != HTTP_METH_GET && txn->meth != HTTP_METH_HEAD))
+		txn->flags |= TX_CACHE_IGNORE;
+
+	http_check_request_for_cacheability(s, &s->req);
+
+	/* The request's hash has to be calculated for all requests, even POSTs
+	 * or PUTs for instance because RFC7234 specifies that a successful
+	 * "unsafe" method on a stored resource must invalidate it
+	 * (see RFC7234#4.4). */
+	if (!sha1_hosturi(s))
+		return ACT_RET_CONT;
+
+	if (s->txn->flags & TX_CACHE_IGNORE)
+		return ACT_RET_CONT;
+
+	if (px == strm_fe(s))
+		_HA_ATOMIC_INC(&px->fe_counters.p.http.cache_lookups);
+	else
+		_HA_ATOMIC_INC(&px->be_counters.p.http.cache_lookups);
+
+	cache_tree = get_cache_tree_from_hash(cache, read_u32(s->txn->cache_hash));
+
+	if (!cache_tree)
+		return ACT_RET_CONT;
+
+	cache_rdlock(cache_tree);
+	res = get_entry(cache_tree, s->txn->cache_hash, 0);
+	/* We must not use an entry that is not complete but the check will be
+	 * performed after we look for a potential secondary entry (in case of
+	 * Vary). */
+	if (res) {
+		struct appctx *appctx;
+		int detached = 0;
+
+		retain_entry(res);
+
+		entry_block = block_ptr(res);
+		shctx_wrlock(shctx);
+		if (res->complete) {
+			shctx_row_detach(shctx, entry_block);
+			detached = 1;
+		} else {
+			release_entry(cache_tree, res, 0);
+			res = NULL;
+		}
+		shctx_wrunlock(shctx);
+		cache_rdunlock(cache_tree);
+
+		/* In case of Vary, we could have multiple entries with the same
+		 * primary hash. We need to calculate the secondary hash in order
+		 * to find the actual entry we want (if it exists). */
+		if (res && res->secondary_key_signature) {
+			if (!http_request_build_secondary_key(s, res->secondary_key_signature)) {
+				cache_rdlock(cache_tree);
+				sec_entry = get_secondary_entry(cache_tree, res,
+				                                s->txn->cache_secondary_hash, 0);
+				if (sec_entry && sec_entry != res) {
+					/* The wrong row was added to the hot list. */
+					release_entry(cache_tree, res, 0);
+					retain_entry(sec_entry);
+					shctx_wrlock(shctx);
+					if (detached)
+						shctx_row_reattach(shctx, entry_block);
+					entry_block = block_ptr(sec_entry);
+					shctx_row_detach(shctx, entry_block);
+					shctx_wrunlock(shctx);
+				}
+				res = sec_entry;
+				cache_rdunlock(cache_tree);
+			}
+			else {
+				release_entry(cache_tree, res, 1);
+
+				res = NULL;
+				shctx_wrlock(shctx);
+				shctx_row_reattach(shctx, entry_block);
+				shctx_wrunlock(shctx);
+			}
+		}
+
+		/* We either looked for a valid secondary entry and could not
+		 * find one, or the entry we want to use is not complete. We
+		 * can't use the cache's entry and must forward the request to
+		 * the server. */
+		if (!res) {
+			return ACT_RET_CONT;
+		} else if (!res->complete) {
+			release_entry(cache_tree, res, 1);
+			return ACT_RET_CONT;
+		}
+
+		s->target = &http_cache_applet.obj_type;
+		if ((appctx = sc_applet_create(s->scb, objt_applet(s->target)))) {
+			struct cache_appctx *ctx = applet_reserve_svcctx(appctx, sizeof(*ctx));
+
+			appctx->st0 = HTX_CACHE_INIT;
+			appctx->rule = rule;
+			ctx->cache_tree = cache_tree;
+			ctx->entry = res;
+			ctx->next = NULL;
+			ctx->sent = 0;
+			ctx->send_notmodified =
+                                should_send_notmodified_response(cache, htxbuf(&s->req.buf), res);
+
+			if (px == strm_fe(s))
+				_HA_ATOMIC_INC(&px->fe_counters.p.http.cache_hits);
+			else
+				_HA_ATOMIC_INC(&px->be_counters.p.http.cache_hits);
+			return ACT_RET_CONT;
+		} else {
+			s->target = NULL;
+			release_entry(cache_tree, res, 1);
+			shctx_wrlock(shctx);
+			shctx_row_reattach(shctx, entry_block);
+			shctx_wrunlock(shctx);
+			return ACT_RET_CONT;
+		}
+	}
+	cache_rdunlock(cache_tree);
+
+	/* Shared context does not need to be locked while we calculate the
+	 * secondary hash. */
+	if (!res && cache->vary_processing_enabled) {
+		/* Build a complete secondary hash until the server response
+		 * tells us which fields should be kept (if any). */
+		http_request_prebuild_full_secondary_key(s);
+	}
+	return ACT_RET_CONT;
+}
+
+
+enum act_parse_ret parse_cache_use(const char **args, int *orig_arg, struct proxy *proxy,
+                                          struct act_rule *rule, char **err)
+{
+	rule->action       = ACT_CUSTOM;
+	rule->action_ptr   = http_action_req_cache_use;
+
+	if (!parse_cache_rule(proxy, args[*orig_arg], rule, err))
+		return ACT_RET_PRS_ERR;
+
+	(*orig_arg)++;
+	return ACT_RET_PRS_OK;
+}
+
+int cfg_parse_cache(const char *file, int linenum, char **args, int kwm)
+{
+	int err_code = 0;
+
+	if (strcmp(args[0], "cache") == 0) { /* new cache section */
+
+		if (!*args[1]) {
+			ha_alert("parsing [%s:%d] : '%s' expects a <name> argument\n",
+				 file, linenum, args[0]);
+			err_code |= ERR_ALERT | ERR_ABORT;
+			goto out;
+		}
+
+		if (alertif_too_many_args(1, file, linenum, args, &err_code)) {
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		if (tmp_cache_config == NULL) {
+			struct cache *cache_config;
+
+			tmp_cache_config = calloc(1, sizeof(*tmp_cache_config));
+			if (!tmp_cache_config) {
+				ha_alert("parsing [%s:%d]: out of memory.\n", file, linenum);
+				err_code |= ERR_ALERT | ERR_ABORT;
+				goto out;
+			}
+
+			strlcpy2(tmp_cache_config->id, args[1], 33);
+			if (strlen(args[1]) > 32) {
+				ha_warning("parsing [%s:%d]: cache name is limited to 32 characters, truncate to '%s'.\n",
+					   file, linenum, tmp_cache_config->id);
+				err_code |= ERR_WARN;
+			}
+
+			list_for_each_entry(cache_config, &caches_config, list) {
+				if (strcmp(tmp_cache_config->id, cache_config->id) == 0) {
+					ha_alert("parsing [%s:%d]: Duplicate cache name '%s'.\n",
+					         file, linenum, tmp_cache_config->id);
+					err_code |= ERR_ALERT | ERR_ABORT;
+					goto out;
+				}
+			}
+
+			tmp_cache_config->maxage = 60;
+			tmp_cache_config->maxblocks = 0;
+			tmp_cache_config->maxobjsz = 0;
+			tmp_cache_config->max_secondary_entries = DEFAULT_MAX_SECONDARY_ENTRY;
+		}
+	} else if (strcmp(args[0], "total-max-size") == 0) {
+		unsigned long int maxsize;
+		char *err;
+
+		if (alertif_too_many_args(1, file, linenum, args, &err_code)) {
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		maxsize = strtoul(args[1], &err, 10);
+		if (err == args[1] || *err != '\0') {
+			ha_warning("parsing [%s:%d]: total-max-size wrong value '%s'\n",
+			           file, linenum, args[1]);
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		if (maxsize > (UINT_MAX >> 20)) {
+			ha_warning("parsing [%s:%d]: \"total-max-size\" (%s) must not be greater than %u\n",
+			           file, linenum, args[1], UINT_MAX >> 20);
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		/* size in megabytes */
+		maxsize *= 1024 * 1024 / CACHE_BLOCKSIZE;
+		tmp_cache_config->maxblocks = maxsize;
+	} else if (strcmp(args[0], "max-age") == 0) {
+		if (alertif_too_many_args(1, file, linenum, args, &err_code)) {
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		if (!*args[1]) {
+			ha_warning("parsing [%s:%d]: '%s' expects an age parameter in seconds.\n",
+			        file, linenum, args[0]);
+			err_code |= ERR_WARN;
+		}
+
+		tmp_cache_config->maxage = atoi(args[1]);
+	} else if (strcmp(args[0], "max-object-size") == 0) {
+		unsigned int maxobjsz;
+		char *err;
+
+		if (alertif_too_many_args(1, file, linenum, args, &err_code)) {
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		if (!*args[1]) {
+			ha_warning("parsing [%s:%d]: '%s' expects a maximum file size parameter in bytes.\n",
+			        file, linenum, args[0]);
+			err_code |= ERR_WARN;
+		}
+
+		maxobjsz = strtoul(args[1], &err, 10);
+		if (err == args[1] || *err != '\0') {
+			ha_warning("parsing [%s:%d]: max-object-size wrong value '%s'\n",
+			           file, linenum, args[1]);
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+		tmp_cache_config->maxobjsz = maxobjsz;
+	} else if (strcmp(args[0], "process-vary") == 0) {
+		if (alertif_too_many_args(1, file, linenum, args, &err_code)) {
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		if (!*args[1]) {
+			ha_warning("parsing [%s:%d]: '%s' expects \"on\" or \"off\" (enable or disable vary processing).\n",
+				   file, linenum, args[0]);
+			err_code |= ERR_WARN;
+		}
+		if (strcmp(args[1], "on") == 0)
+			tmp_cache_config->vary_processing_enabled = 1;
+		else if (strcmp(args[1], "off") == 0)
+			tmp_cache_config->vary_processing_enabled = 0;
+		else {
+			ha_warning("parsing [%s:%d]: '%s' expects \"on\" or \"off\" (enable or disable vary processing).\n",
+				   file, linenum, args[0]);
+			err_code |= ERR_WARN;
+		}
+	} else if (strcmp(args[0], "max-secondary-entries") == 0) {
+		unsigned int max_sec_entries;
+		char *err;
+
+		if (alertif_too_many_args(1, file, linenum, args, &err_code)) {
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+
+		if (!*args[1]) {
+			ha_warning("parsing [%s:%d]: '%s' expects a strictly positive number.\n",
+				   file, linenum, args[0]);
+			err_code |= ERR_WARN;
+		}
+
+		max_sec_entries = strtoul(args[1], &err, 10);
+		if (err == args[1] || *err != '\0' || max_sec_entries == 0) {
+			ha_warning("parsing [%s:%d]: max-secondary-entries wrong value '%s'\n",
+			           file, linenum, args[1]);
+			err_code |= ERR_ABORT;
+			goto out;
+		}
+		tmp_cache_config->max_secondary_entries = max_sec_entries;
+	}
+	else if (*args[0] != 0) {
+		ha_alert("parsing [%s:%d] : unknown keyword '%s' in 'cache' section\n", file, linenum, args[0]);
+		err_code |= ERR_ALERT | ERR_FATAL;
+		goto out;
+	}
+out:
+	return err_code;
+}
+
+/* once the cache section is parsed */
+
+int cfg_post_parse_section_cache()
+{
+	int err_code = 0;
+
+	if (tmp_cache_config) {
+
+		if (tmp_cache_config->maxblocks <= 0) {
+			ha_alert("Size not specified for cache '%s'\n", tmp_cache_config->id);
+			err_code |= ERR_FATAL | ERR_ALERT;
+			goto out;
+		}
+
+		if (!tmp_cache_config->maxobjsz) {
+			/* Default max. file size is a 256th of the cache size. */
+			tmp_cache_config->maxobjsz =
+				(tmp_cache_config->maxblocks * CACHE_BLOCKSIZE) >> 8;
+		}
+		else if (tmp_cache_config->maxobjsz > tmp_cache_config->maxblocks * CACHE_BLOCKSIZE / 2) {
+			ha_alert("\"max-object-size\" is limited to an half of \"total-max-size\" => %u\n", tmp_cache_config->maxblocks * CACHE_BLOCKSIZE / 2);
+			err_code |= ERR_FATAL | ERR_ALERT;
+			goto out;
+		}
+
+		/* add to the list of cache to init and reinit tmp_cache_config
+		 * for next cache section, if any.
+		 */
+		LIST_APPEND(&caches_config, &tmp_cache_config->list);
+		tmp_cache_config = NULL;
+		return err_code;
+	}
+out:
+	ha_free(&tmp_cache_config);
+	return err_code;
+
+}
+
+int post_check_cache()
+{
+	struct proxy *px;
+	struct cache *back, *cache_config, *cache;
+	struct shared_context *shctx;
+	int ret_shctx;
+	int err_code = ERR_NONE;
+	int i;
+
+	list_for_each_entry_safe(cache_config, back, &caches_config, list) {
+
+		ret_shctx = shctx_init(&shctx, cache_config->maxblocks, CACHE_BLOCKSIZE,
+		                       cache_config->maxobjsz, sizeof(struct cache));
+
+		if (ret_shctx <= 0) {
+			if (ret_shctx == SHCTX_E_INIT_LOCK)
+				ha_alert("Unable to initialize the lock for the cache.\n");
+			else
+				ha_alert("Unable to allocate cache.\n");
+
+			err_code |= ERR_FATAL | ERR_ALERT;
+			goto out;
+		}
+		shctx->free_block = cache_free_blocks;
+		shctx->reserve_finish = cache_reserve_finish;
+		shctx->cb_data = (void*)shctx->data;
+		/* the cache structure is stored in the shctx and added to the
+		 * caches list, we can remove the entry from the caches_config
+		 * list */
+		memcpy(shctx->data, cache_config, sizeof(struct cache));
+		cache = (struct cache *)shctx->data;
+		LIST_APPEND(&caches, &cache->list);
+		LIST_DELETE(&cache_config->list);
+		free(cache_config);
+		for (i = 0; i < CACHE_TREE_NUM; ++i) {
+			cache->trees[i].entries = EB_ROOT;
+			HA_RWLOCK_INIT(&cache->trees[i].lock);
+
+			LIST_INIT(&cache->trees[i].cleanup_list);
+			HA_SPIN_INIT(&cache->trees[i].cleanup_lock);
+		}
+
+		/* Find all references for this cache in the existing filters
+		 * (over all proxies) and reference it in matching filters.
+		 */
+		for (px = proxies_list; px; px = px->next) {
+			struct flt_conf *fconf;
+			struct cache_flt_conf *cconf;
+
+			list_for_each_entry(fconf, &px->filter_configs, list) {
+				if (fconf->id != cache_store_flt_id)
+					continue;
+
+				cconf = fconf->conf;
+				if (strcmp(cache->id, cconf->c.name) == 0) {
+					free(cconf->c.name);
+					cconf->flags |= CACHE_FLT_INIT;
+					cconf->c.cache = cache;
+					break;
+				}
+			}
+		}
+	}
+
+out:
+	return err_code;
+
+}
+
+struct flt_ops cache_ops = {
+	.init   = cache_store_init,
+	.check  = cache_store_check,
+	.deinit = cache_store_deinit,
+
+	/* Handle stream init/deinit */
+	.attach = cache_store_strm_init,
+	.detach = cache_store_strm_deinit,
+
+	/* Handle channels activity */
+	.channel_post_analyze = cache_store_post_analyze,
+
+	/* Filter HTTP requests and responses */
+	.http_headers        = cache_store_http_headers,
+	.http_payload        = cache_store_http_payload,
+	.http_end            = cache_store_http_end,
+};
+
+
+#define CHECK_ENCODING(str, encoding_name, encoding_value) \
+	({ \
+		int retval = 0; \
+		if (istmatch(str, (struct ist){ .ptr = encoding_name+1, .len = sizeof(encoding_name) - 2 })) { \
+			retval = encoding_value; \
+			encoding = istadv(encoding, sizeof(encoding_name) - 2); \
+		} \
+		(retval); \
+	})
+
+/*
+ * Parse the encoding <encoding> and try to match the encoding part upon an
+ * encoding list of explicitly supported encodings (which all have a specific
+ * bit in an encoding bitmap). If a weight is included in the value, find out if
+ * it is null or not. The bit value will be set in the <encoding_value>
+ * parameter and the <has_null_weight> will be set to 1 if the weight is strictly
+ * 0, 1 otherwise.
+ * The encodings list is extracted from
+ * https://www.iana.org/assignments/http-parameters/http-parameters.xhtml.
+ * Returns 0 in case of success and -1 in case of error.
+ */
+static int parse_encoding_value(struct ist encoding, unsigned int *encoding_value,
+				unsigned int *has_null_weight)
+{
+	int retval = 0;
+
+	if (!encoding_value)
+		return -1;
+
+	if (!istlen(encoding))
+		return -1;	/* Invalid encoding */
+
+	*encoding_value = 0;
+	if (has_null_weight)
+		*has_null_weight = 0;
+
+	switch (*encoding.ptr) {
+	case 'a':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "aes128gcm", VARY_ENCODING_AES128GCM);
+		break;
+	case 'b':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "br", VARY_ENCODING_BR);
+		break;
+	case 'c':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "compress", VARY_ENCODING_COMPRESS);
+		break;
+	case 'd':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "deflate", VARY_ENCODING_DEFLATE);
+		break;
+	case 'e':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "exi", VARY_ENCODING_EXI);
+		break;
+	case 'g':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "gzip", VARY_ENCODING_GZIP);
+		break;
+	case 'i':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "identity", VARY_ENCODING_IDENTITY);
+		break;
+	case 'p':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "pack200-gzip", VARY_ENCODING_PACK200_GZIP);
+		break;
+	case 'x':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "x-gzip", VARY_ENCODING_GZIP);
+		if (!*encoding_value)
+			*encoding_value = CHECK_ENCODING(encoding, "x-compress", VARY_ENCODING_COMPRESS);
+		break;
+	case 'z':
+		encoding = istnext(encoding);
+		*encoding_value = CHECK_ENCODING(encoding, "zstd", VARY_ENCODING_ZSTD);
+		break;
+	case '*':
+		encoding = istnext(encoding);
+		*encoding_value = VARY_ENCODING_STAR;
+		break;
+	default:
+		retval = -1; /* Unmanaged encoding */
+		break;
+	}
+
+	/* Process the optional weight part of the encoding. */
+	if (*encoding_value) {
+		encoding = http_trim_leading_spht(encoding);
+		if (istlen(encoding)) {
+			if (*encoding.ptr != ';')
+				return -1;
+
+			if (has_null_weight) {
+				encoding = istnext(encoding);
+
+				encoding = http_trim_leading_spht(encoding);
+
+				*has_null_weight = isteq(encoding, ist("q=0"));
+			}
+		}
+	}
+
+	return retval;
+}
+
+#define ACCEPT_ENCODING_MAX_ENTRIES 16
+/*
+ * Build a bitmap of the accept-encoding header.
+ *
+ * The bitmap is built by matching every sub-part of the accept-encoding value
+ * with a subset of explicitly supported encodings, which all have their own bit
+ * in the bitmap. This bitmap will be used to determine if a response can be
+ * served to a client (that is if it has an encoding that is accepted by the
+ * client). Any unknown encodings will be indicated by the VARY_ENCODING_OTHER
+ * bit.
+ *
+ * Returns 0 in case of success and -1 in case of error.
+ */
+static int accept_encoding_normalizer(struct htx *htx, struct ist hdr_name,
+				      char *buf, unsigned int *buf_len)
+{
+	size_t count = 0;
+	uint32_t encoding_bitmap = 0;
+	unsigned int encoding_bmp_bl = -1;
+	struct http_hdr_ctx ctx = { .blk = NULL };
+	unsigned int encoding_value;
+	unsigned int rejected_encoding;
+
+	/* A user agent always accepts an unencoded value unless it explicitly
+	 * refuses it through an "identity;q=0" accept-encoding value. */
+	encoding_bitmap |= VARY_ENCODING_IDENTITY;
+
+	/* Iterate over all the ACCEPT_ENCODING_MAX_ENTRIES first accept-encoding
+	 * values that might span acrosse multiple accept-encoding headers. */
+	while (http_find_header(htx, hdr_name, &ctx, 0) && count < ACCEPT_ENCODING_MAX_ENTRIES) {
+		count++;
+
+		/* As per RFC7231#5.3.4, "An Accept-Encoding header field with a
+		 * combined field-value that is empty implies that the user agent
+		 * does not want any content-coding in response."
+		 *
+		 * We must (and did) count the existence of this empty header to not
+		 * hit the `count == 0` case below, but must ignore the value to not
+		 * include VARY_ENCODING_OTHER into the final bitmap.
+		 */
+		if (istlen(ctx.value) == 0)
+			continue;
+
+		/* Turn accept-encoding value to lower case */
+		ist2bin_lc(istptr(ctx.value), ctx.value);
+
+		/* Try to identify a known encoding and to manage null weights. */
+		if (!parse_encoding_value(ctx.value, &encoding_value, &rejected_encoding)) {
+			if (rejected_encoding)
+				encoding_bmp_bl &= ~encoding_value;
+			else
+				encoding_bitmap |= encoding_value;
+		}
+		else {
+			/* Unknown encoding */
+			encoding_bitmap |= VARY_ENCODING_OTHER;
+		}
+	}
+
+	/* If a "*" was found in the accepted encodings (without a null weight),
+	 * all the encoding are accepted except the ones explicitly rejected. */
+	if (encoding_bitmap & VARY_ENCODING_STAR) {
+		encoding_bitmap = ~0;
+	}
+
+	/* Clear explicitly rejected encodings from the bitmap */
+	encoding_bitmap &= encoding_bmp_bl;
+
+	/* As per RFC7231#5.3.4, "If no Accept-Encoding field is in the request,
+	 * any content-coding is considered acceptable by the user agent". */
+	if (count == 0)
+		encoding_bitmap = ~0;
+
+	/* A request with more than ACCEPT_ENCODING_MAX_ENTRIES accepted
+	 * encodings might be illegitimate so we will not use it. */
+	if (count == ACCEPT_ENCODING_MAX_ENTRIES)
+		return -1;
+
+	write_u32(buf, encoding_bitmap);
+	*buf_len = sizeof(encoding_bitmap);
+
+	/* This function fills the hash buffer correctly even if no header was
+	 * found, hence the 0 return value (success). */
+	return 0;
+}
+#undef ACCEPT_ENCODING_MAX_ENTRIES
+
+/*
+ * Normalizer used by default for the Referer and Origin header. It only
+ * calculates a hash of the whole value using xxhash algorithm.
+ * Only the first occurrence of the header will be taken into account in the
+ * hash.
+ * Returns 0 in case of success, 1 if the hash buffer should be filled with 0s
+ * and -1 in case of error.
+ */
+static int default_normalizer(struct htx *htx, struct ist hdr_name,
+			      char *buf, unsigned int *buf_len)
+{
+	int retval = 1;
+	struct http_hdr_ctx ctx = { .blk = NULL };
+
+	if (http_find_header(htx, hdr_name, &ctx, 1)) {
+		retval = 0;
+		write_u64(buf, XXH3(istptr(ctx.value), istlen(ctx.value), cache_hash_seed));
+		*buf_len = sizeof(uint64_t);
+	}
+
+	return retval;
+}
+
+/*
+ * Accept-Encoding bitmap comparison function.
+ * Returns 0 if the bitmaps are compatible.
+ */
+static int accept_encoding_bitmap_cmp(const void *ref, const void *new, unsigned int len)
+{
+	uint32_t ref_bitmap = read_u32(ref);
+	uint32_t new_bitmap = read_u32(new);
+
+	if (!(ref_bitmap & VARY_ENCODING_OTHER)) {
+		/* All the bits set in the reference bitmap correspond to the
+		 * stored response' encoding and should all be set in the new
+		 * encoding bitmap in order for the client to be able to manage
+		 * the response.
+		 *
+		 * If this is the case the cached response has encodings that
+		 * are accepted by the client. It can be served directly by
+		 * the cache (as far as the accept-encoding part is concerned).
+		 */
+
+		return (ref_bitmap & new_bitmap) != ref_bitmap;
+	}
+	else {
+		return 1;
+	}
+}
+
+
+/*
+ * Pre-calculate the hashes of all the supported headers (in our Vary
+ * implementation) of a given request. We have to calculate all the hashes
+ * in advance because the actual Vary signature won't be known until the first
+ * response.
+ * Only the first occurrence of every header will be taken into account in the
+ * hash.
+ * If the header is not present, the hash portion of the given header will be
+ * filled with zeros.
+ * Returns 0 in case of success.
+ */
+static int http_request_prebuild_full_secondary_key(struct stream *s)
+{
+	/* The fake signature (second parameter) will ensure that every part of the
+	 * secondary key is calculated. */
+	return http_request_build_secondary_key(s, ~0);
+}
+
+
+/*
+ * Calculate the secondary key for a request for which we already have a known
+ * vary signature. The key is made by aggregating hashes calculated for every
+ * header mentioned in the vary signature.
+ * Only the first occurrence of every header will be taken into account in the
+ * hash.
+ * If the header is not present, the hash portion of the given header will be
+ * filled with zeros.
+ * Returns 0 in case of success.
+ */
+static int http_request_build_secondary_key(struct stream *s, int vary_signature)
+{
+	struct http_txn *txn = s->txn;
+	struct htx *htx = htxbuf(&s->req.buf);
+
+	unsigned int idx;
+	const struct vary_hashing_information *info = NULL;
+	unsigned int hash_length = 0;
+	int retval = 0;
+	int offset = 0;
+
+	for (idx = 0; idx < sizeof(vary_information)/sizeof(*vary_information) && retval >= 0; ++idx) {
+		info = &vary_information[idx];
+
+		/* The normalizing functions will be in charge of getting the
+		 * header values from the htx. This way they can manage multiple
+		 * occurrences of their processed header. */
+		if ((vary_signature & info->value) && info->norm_fn != NULL &&
+		    !(retval = info->norm_fn(htx, info->hdr_name, &txn->cache_secondary_hash[offset], &hash_length))) {
+			offset += hash_length;
+		}
+		else {
+			/* Fill hash with 0s. */
+			hash_length = info->hash_length;
+			memset(&txn->cache_secondary_hash[offset], 0, hash_length);
+			offset += hash_length;
+		}
+	}
+
+	if (retval >= 0)
+		txn->flags |= TX_CACHE_HAS_SEC_KEY;
+
+	return (retval < 0);
+}
+
+/*
+ * Build the actual secondary key of a given request out of the prebuilt key and
+ * the actual vary signature (extracted from the response).
+ * Returns 0 in case of success.
+ */
+static int http_request_reduce_secondary_key(unsigned int vary_signature,
+					     char prebuilt_key[HTTP_CACHE_SEC_KEY_LEN])
+{
+	int offset = 0;
+	int global_offset = 0;
+	int vary_info_count = 0;
+	int keep = 0;
+	unsigned int vary_idx;
+	const struct vary_hashing_information *vary_info;
+
+	vary_info_count = sizeof(vary_information)/sizeof(*vary_information);
+	for (vary_idx = 0; vary_idx < vary_info_count; ++vary_idx) {
+		vary_info = &vary_information[vary_idx];
+		keep = (vary_signature & vary_info->value) ? 0xff : 0;
+
+		for (offset = 0; offset < vary_info->hash_length; ++offset,++global_offset) {
+			prebuilt_key[global_offset] &= keep;
+		}
+	}
+
+	return 0;
+}
+
+
+
+static int
+parse_cache_flt(char **args, int *cur_arg, struct proxy *px,
+		struct flt_conf *fconf, char **err, void *private)
+{
+	struct flt_conf *f, *back;
+	struct cache_flt_conf *cconf = NULL;
+	char *name = NULL;
+	int pos = *cur_arg;
+
+	/* Get the cache filter name. <pos> point on "cache" keyword */
+	if (!*args[pos + 1]) {
+		memprintf(err, "%s : expects a <name> argument", args[pos]);
+		goto error;
+	}
+	name = strdup(args[pos + 1]);
+	if (!name) {
+		memprintf(err, "%s '%s' : out of memory", args[pos], args[pos + 1]);
+		goto error;
+	}
+	pos += 2;
+
+	/* Check if an implicit filter with the same name already exists. If so,
+	 * we remove the implicit filter to use the explicit one. */
+	list_for_each_entry_safe(f, back, &px->filter_configs, list) {
+		if (f->id != cache_store_flt_id)
+			continue;
+
+		cconf = f->conf;
+		if (strcmp(name, cconf->c.name) != 0) {
+			cconf = NULL;
+			continue;
+		}
+
+		if (!(cconf->flags & CACHE_FLT_F_IMPLICIT_DECL)) {
+			cconf = NULL;
+			memprintf(err, "%s: multiple explicit declarations of the cache filter '%s'",
+				  px->id, name);
+			goto error;
+		}
+
+		/* Remove the implicit filter. <cconf> is kept for the explicit one */
+		LIST_DELETE(&f->list);
+		free(f);
+		free(name);
+		break;
+	}
+
+	/* No implicit cache filter found, create configuration for the explicit one */
+	if (!cconf) {
+		cconf = calloc(1, sizeof(*cconf));
+		if (!cconf) {
+			memprintf(err, "%s: out of memory", args[*cur_arg]);
+			goto error;
+		}
+		cconf->c.name = name;
+	}
+
+	cconf->flags = 0;
+	fconf->id   = cache_store_flt_id;
+	fconf->conf = cconf;
+	fconf->ops  = &cache_ops;
+
+	*cur_arg = pos;
+	return 0;
+
+  error:
+	free(name);
+	free(cconf);
+	return -1;
+}
+
+/* It reserves a struct show_cache_ctx for the local variables */
+static int cli_parse_show_cache(char **args, char *payload, struct appctx *appctx, void *private)
+{
+	struct show_cache_ctx *ctx = applet_reserve_svcctx(appctx, sizeof(*ctx));
+
+	if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
+		return 1;
+
+	ctx->cache = LIST_ELEM((caches).n, typeof(struct cache *), list);
+	return 0;
+}
+
+/* It uses a struct show_cache_ctx for the local variables */
+static int cli_io_handler_show_cache(struct appctx *appctx)
+{
+	struct show_cache_ctx *ctx = appctx->svcctx;
+	struct cache* cache = ctx->cache;
+	struct buffer *buf = alloc_trash_chunk();
+
+	if (buf == NULL)
+		return 1;
+
+	list_for_each_entry_from(cache, &caches, list) {
+		struct eb32_node *node = NULL;
+		unsigned int next_key;
+		struct cache_entry *entry;
+		unsigned int i;
+		struct shared_context *shctx = shctx_ptr(cache);
+		int cache_tree_index = 0;
+		struct cache_tree *cache_tree = NULL;
+
+		next_key = ctx->next_key;
+		if (!next_key) {
+			shctx_rdlock(shctx);
+			chunk_printf(buf, "%p: %s (shctx:%p, available blocks:%d)\n", cache, cache->id, shctx_ptr(cache), shctx_ptr(cache)->nbav);
+			shctx_rdunlock(shctx);
+			if (applet_putchk(appctx, buf) == -1) {
+				goto yield;
+			}
+		}
+
+		ctx->cache = cache;
+
+		if (ctx->cache_tree)
+			cache_tree_index = (ctx->cache_tree - ctx->cache->trees);
+
+		for (;cache_tree_index < CACHE_TREE_NUM; ++cache_tree_index) {
+
+			ctx->cache_tree = cache_tree = &ctx->cache->trees[cache_tree_index];
+
+			cache_rdlock(cache_tree);
+
+			while (1) {
+				node = eb32_lookup_ge(&cache_tree->entries, next_key);
+				if (!node) {
+					ctx->next_key = 0;
+					break;
+				}
+
+				entry = container_of(node, struct cache_entry, eb);
+				next_key = node->key + 1;
+
+				if (entry->expire > date.tv_sec) {
+					chunk_printf(buf, "%p hash:%u vary:0x", entry, read_u32(entry->hash));
+					for (i = 0; i < HTTP_CACHE_SEC_KEY_LEN; ++i)
+						chunk_appendf(buf, "%02x", (unsigned char)entry->secondary_key[i]);
+					chunk_appendf(buf, " size:%u (%u blocks), refcount:%u, expire:%d\n",
+						      block_ptr(entry)->len, block_ptr(entry)->block_count,
+						      block_ptr(entry)->refcount, entry->expire - (int)date.tv_sec);
+				}
+
+				ctx->next_key = next_key;
+
+				if (applet_putchk(appctx, buf) == -1) {
+					cache_rdunlock(cache_tree);
+					goto yield;
+				}
+			}
+			cache_rdunlock(cache_tree);
+		}
+	}
+
+	free_trash_chunk(buf);
+	return 1;
+
+yield:
+	free_trash_chunk(buf);
+	return 0;
+}
+
+
+/*
+ * boolean, returns true if response was built out of a cache entry.
+ */
+static int
+smp_fetch_res_cache_hit(const struct arg *args, struct sample *smp,
+                        const char *kw, void *private)
+{
+	smp->data.type = SMP_T_BOOL;
+	smp->data.u.sint = (smp->strm ? (smp->strm->target == &http_cache_applet.obj_type) : 0);
+
+	return 1;
+}
+
+/*
+ * string, returns cache name (if response came from a cache).
+ */
+static int
+smp_fetch_res_cache_name(const struct arg *args, struct sample *smp,
+                         const char *kw, void *private)
+{
+	struct appctx *appctx = NULL;
+
+	struct cache_flt_conf *cconf = NULL;
+	struct cache *cache = NULL;
+
+	if (!smp->strm || smp->strm->target != &http_cache_applet.obj_type)
+		return 0;
+
+	/* Get appctx from the stream connector. */
+	appctx = sc_appctx(smp->strm->scb);
+	if (appctx && appctx->rule) {
+		cconf = appctx->rule->arg.act.p[0];
+		if (cconf) {
+			cache = cconf->c.cache;
+
+			smp->data.type = SMP_T_STR;
+			smp->flags = SMP_F_CONST;
+			smp->data.u.str.area = cache->id;
+			smp->data.u.str.data = strlen(cache->id);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+
+/* early boot initialization */
+static void cache_init()
+{
+	cache_hash_seed = ha_random64();
+}
+
+INITCALL0(STG_PREPARE, cache_init);
+
+/* Declare the filter parser for "cache" keyword */
+static struct flt_kw_list filter_kws = { "CACHE", { }, {
+		{ "cache", parse_cache_flt, NULL },
+		{ NULL, NULL, NULL },
+	}
+};
+
+INITCALL1(STG_REGISTER, flt_register_keywords, &filter_kws);
+
+static struct cli_kw_list cli_kws = {{},{
+	{ { "show", "cache", NULL }, "show cache                              : show cache status", cli_parse_show_cache, cli_io_handler_show_cache, NULL, NULL },
+	{{},}
+}};
+
+INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);
+
+static struct action_kw_list http_res_actions = {
+	.kw = {
+		{ "cache-store", parse_cache_store },
+		{ NULL, NULL }
+	}
+};
+
+INITCALL1(STG_REGISTER, http_res_keywords_register, &http_res_actions);
+
+static struct action_kw_list http_req_actions = {
+	.kw = {
+		{ "cache-use", parse_cache_use },
+		{ NULL, NULL }
+	}
+};
+
+INITCALL1(STG_REGISTER, http_req_keywords_register, &http_req_actions);
+
+struct applet http_cache_applet = {
+	.obj_type = OBJ_TYPE_APPLET,
+	.name = "<CACHE>", /* used for logging */
+	.fct = http_cache_io_handler,
+	.release = http_cache_applet_release,
+};
+
+/* config parsers for this section */
+REGISTER_CONFIG_SECTION("cache", cfg_parse_cache, cfg_post_parse_section_cache);
+REGISTER_POST_CHECK(post_check_cache);
+
+
+/* Note: must not be declared <const> as its list will be overwritten */
+static struct sample_fetch_kw_list sample_fetch_keywords = {ILH, {
+		{ "res.cache_hit",  smp_fetch_res_cache_hit,  0, NULL, SMP_T_BOOL, SMP_USE_HRSHP, SMP_VAL_RESPONSE },
+		{ "res.cache_name", smp_fetch_res_cache_name, 0, NULL, SMP_T_STR,  SMP_USE_HRSHP, SMP_VAL_RESPONSE },
+		{ /* END */ },
+	}
+};
+
+INITCALL1(STG_REGISTER, sample_register_fetches, &sample_fetch_keywords);