1 files changed, 184 insertions, 0 deletions
diff --git a/include/haproxy/hpack-tbl.h b/include/haproxy/hpack-tbl.h
new file mode 100644
index 0000000..02cf7db
--- /dev/null
+++ b/include/haproxy/hpack-tbl.h
@@ -0,0 +1,184 @@
+/*
+ * HPACK header table management (RFC7541) - prototypes
+ *
+ * Copyright (C) 2014-2020 Willy Tarreau <willy@haproxy.org>
+ * Copyright (C) 2017 HAProxy Technologies
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef _HAPROXY_HPACK_TBL_H
+#define _HAPROXY_HPACK_TBL_H
+
+#include <import/ist.h>
+#include <haproxy/api.h>
+#include <haproxy/hpack-tbl-t.h>
+#include <haproxy/http-hdr-t.h>
+
+/* when built outside of haproxy, HPACK_STANDALONE must be defined, and
+ * pool_head_hpack_tbl->size must be set to the DHT size.
+ */
+#ifndef HPACK_STANDALONE
+#include <haproxy/pool.h>
+#define hpack_alloc(pool)      pool_alloc(pool)
+#define hpack_free(pool, ptr)  pool_free(pool, ptr)
+#else
+#include <stdlib.h>
+#include <haproxy/pool-t.h>
+#define hpack_alloc(pool)      malloc(pool->size)
+#define hpack_free(pool, ptr)  free(ptr)
+#endif
+
+extern const struct http_hdr hpack_sht[HPACK_SHT_SIZE];
+extern struct pool_head *pool_head_hpack_tbl;
+
+int __hpack_dht_make_room(struct hpack_dht *dht, unsigned int needed);
+int hpack_dht_insert(struct hpack_dht *dht, struct ist name, struct ist value);
+
+#ifdef DEBUG_HPACK
+void hpack_dht_dump(FILE *out, const struct hpack_dht *dht);
+void hpack_dht_check_consistency(const struct hpack_dht *dht);
+#endif
+
+/* return a pointer to the entry designated by index <idx> (starting at 1) or
+ * NULL if this index is not there.
+ */
+static inline const struct hpack_dte *hpack_get_dte(const struct hpack_dht *dht, uint16_t idx)
+{
+	idx--;
+
+	if (idx >= dht->used)
+		return NULL;
+
+	if (idx <= dht->head)
+		idx = dht->head - idx;
+	else
+		idx = dht->head - idx + dht->wrap;
+
+	return &dht->dte[idx];
+}
+
+/* returns non-zero if <idx> is valid for table <dht> */
+static inline int hpack_valid_idx(const struct hpack_dht *dht, uint32_t idx)
+{
+	return idx < dht->used + HPACK_SHT_SIZE;
+}
+
+/* return a pointer to the header name for entry <dte>. */
+static inline struct ist hpack_get_name(const struct hpack_dht *dht, const struct hpack_dte *dte)
+{
+	struct ist ret = {
+		.ptr = (void *)dht + dte->addr,
+		.len = dte->nlen,
+	};
+	return ret;
+}
+
+/* return a pointer to the header value for entry <dte>. */
+static inline struct ist hpack_get_value(const struct hpack_dht *dht, const struct hpack_dte *dte)
+{
+	struct ist ret = {
+		.ptr = (void *)dht + dte->addr + dte->nlen,
+		.len = dte->vlen,
+	};
+	return ret;
+}
+
+/* takes an idx, returns the associated name */
+static inline struct ist hpack_idx_to_name(const struct hpack_dht *dht, uint32_t idx)
+{
+	const struct hpack_dte *dte;
+
+	if (idx < HPACK_SHT_SIZE)
+		return hpack_sht[idx].n;
+
+	dte = hpack_get_dte(dht, idx - HPACK_SHT_SIZE + 1);
+	if (!dte)
+		return ist("### ERR ###"); // error
+
+	return hpack_get_name(dht, dte);
+}
+
+/* takes an idx, returns the associated value */
+static inline struct ist hpack_idx_to_value(const struct hpack_dht *dht, uint32_t idx)
+{
+	const struct hpack_dte *dte;
+
+	if (idx < HPACK_SHT_SIZE)
+		return hpack_sht[idx].v;
+
+	dte = hpack_get_dte(dht, idx - HPACK_SHT_SIZE + 1);
+	if (!dte)
+		return ist("### ERR ###"); // error
+
+	return hpack_get_value(dht, dte);
+}
+
+/* returns the slot number of the oldest entry (tail). Must not be used on an
+ * empty table.
+ */
+static inline unsigned int hpack_dht_get_tail(const struct hpack_dht *dht)
+{
+	return ((dht->head + 1U < dht->used) ? dht->wrap : 0) + dht->head + 1U - dht->used;
+}
+
+/* Purges table dht until a header field of <needed> bytes fits according to
+ * the protocol (adding 32 bytes overhead). Returns non-zero on success, zero
+ * on failure (ie: table empty but still not sufficient).
+ */
+static inline int hpack_dht_make_room(struct hpack_dht *dht, unsigned int needed)
+{
+	if (dht->used * 32 + dht->total + needed + 32 <= dht->size)
+		return 1;
+	else if (!dht->used)
+		return 0;
+
+	return __hpack_dht_make_room(dht, needed);
+}
+
+/* allocate a dynamic headers table of <size> bytes and return it initialized */
+static inline void hpack_dht_init(struct hpack_dht *dht, uint32_t size)
+{
+	dht->size = size;
+	dht->total = 0;
+	dht->used = 0;
+}
+
+/* allocate a dynamic headers table from the pool and return it initialized */
+static inline struct hpack_dht *hpack_dht_alloc()
+{
+	struct hpack_dht *dht;
+
+	if (unlikely(!pool_head_hpack_tbl))
+		return NULL;
+
+	dht = hpack_alloc(pool_head_hpack_tbl);
+	if (dht)
+		hpack_dht_init(dht, pool_head_hpack_tbl->size);
+	return dht;
+}
+
+/* free a dynamic headers table */
+static inline void hpack_dht_free(struct hpack_dht *dht)
+{
+	hpack_free(pool_head_hpack_tbl, dht);
+}
+
+#endif /* _HAPROXY_HPACK_TBL_H */