HTTP/2 Parser implementation (#309):

1. Changes in HPACK decoder to copy only Huffman-decoded and dynamically indexed headers;
2. Appropriate changes in HPACK-decoder/parser unit-tests.

tempesta_fw/hpack.h

@@ -105,19 +105,6 @@ typedef struct {
 	TFW_HPACK_ETBL_COMMON;
 } TfwHPackETblIter;
 
-/**
- * HPack strings representation.
- *
- * @ptr		- pointer to the actual string data;
- * @len		- length of the string;
- * @count	- number of users of the string instance.
- */
-typedef struct {
-	char			*ptr;
-	unsigned long		len;
-	int			count;
-} TfwHPackStr;
-
 typedef enum {
 	TFW_H2_TRANS_ADD	= 0,
 	TFW_H2_TRANS_EXPAND,
@@ -153,23 +140,28 @@ typedef enum {
 /**
  * Representation of the entry in HPack decoder index.
  *
+ * @hdr		- pointer to the header data descriptor;
  * @name_len	- length of the header's name part;
  * @name_num	- chunks count of the header's name part;
  * @tag		- tag of the indexed header;
- * @hdr		- descriptor of the header data.
+ * @last	- flag bit indicating that corresponding header is the last on the page.
  */
 typedef struct {
+	TfwStr			*hdr;
 	unsigned long		name_len;
-	unsigned int		name_num;
+	unsigned long		name_num;
 	unsigned int		tag;
-	TfwStr			hdr[0];
+	unsigned char		last : 1;
 } TfwHPackEntry;
 
 /**
  * HPack decoder dynamic index table.
  *
  * @entries	- dynamic table of entries;
- * @pool	- memory pool for dynamic table;
+ * @pool	- memory pool for constantly sized entries (i.e. the entry
+ *		  descriptors);
+ * @h_pool	- memory pool for entries of variable size (headers themselves
+ *		- and @TfwStr descriptors for them);
  * @n		- actual number of entries in the table;
  * @curr	- circular buffer index of recent entry;
  * @length	- current length of the dynamic table (in entries);
@@ -180,6 +172,7 @@ typedef struct {
 typedef struct {
 	TfwHPackEntry		*entries;
 	TfwPool			*pool;
+	TfwPool			*h_pool;
 	unsigned int		n;
 	unsigned int		curr;
 	unsigned int		length;

tempesta_fw/http_frame.c

@@ -922,9 +922,6 @@ tfw_h2_apply_settings_entry(TfwH2Ctx *ctx, unsigned short id,
 		return T_OK;
 	}
 
-	/*
-	 * TODO #309: apply settings entry.
-	 */
 	return T_OK;
 }
 

tempesta_fw/http_msg.c

@@ -251,6 +251,35 @@ __http_msg_hdr_val(TfwStr *hdr, unsigned id, TfwStr *val, bool client)
 }
 EXPORT_SYMBOL(__http_msg_hdr_val);
 
+void
+__h2_msg_hdr_name(TfwStr *hdr, TfwStr *out_name)
+{
+	TfwStr *c, *end;
+
+	if (unlikely(TFW_STR_EMPTY(hdr))) {
+		TFW_STR_INIT(out_val);
+		return;
+	}
+
+	BUG_ON(TFW_STR_DUP(hdr));
+	BUG_ON(TFW_STR_EMPTY(hdr));
+
+	*out_name = *hdr;
+
+	if (unlikely(TFW_STR_PLAIN(hdr))) {
+		WARN_ON_ONCE(hdr->flags & TFW_STR_HDR_VALUE)
+		return;
+	}
+
+	TFW_STR_FOR_EACH_CHUNK(c, hdr, end) {
+		if (c->flags & TFW_STR_HDR_VALUE) {
+			out_name->len -= c->len;
+			out_name->nchunks--;
+		}
+	}
+}
+EXPORT_SYMBOL(__h2_msg_hdr_name);
+
 void
 __h2_msg_hdr_val(TfwStr *hdr, TfwStr *out_val)
 {
@@ -277,6 +306,7 @@ __h2_msg_hdr_val(TfwStr *hdr, TfwStr *out_val)
 	/* Empty header value part. */
 	TFW_STR_INIT(out_val);
 }
+EXPORT_SYMBOL(__h2_msg_hdr_val);
 
 /**
  * Slow check of generic (raw) header for singularity.
@@ -504,7 +534,15 @@ tfw_http_msg_hdr_close(TfwHttpMsg *hm)
 	 * Both the headers, the new one and existing one, can already be
 	 * compound.
 	 */
-	id = __hdr_lookup(hm, &parser->hdr);
+	if (TFW_MSG_H2(hm)) {
+		TfwStr h_name;
+
+		__h2_msg_hdr_name(&parser->hdr, &h_name);
+		id = __h2_hdr_lookup(hm, &h_name);
+	}
+	else {
+		id = __hdr_lookup(hm, &parser->hdr);
+	}
 
 	/* Allocate some more room if not enough to store the header. */
 	if (unlikely(id == ht->size)) {

tempesta_fw/http_msg.h

@@ -50,6 +50,7 @@ __tfw_http_msg_set_str_data(TfwStr *str, void *data, struct sk_buff *skb)
 	__tfw_http_msg_set_str_data(str, data,				\
 				    ss_skb_peek_tail(&hm->msg.skb_head))
 
+void __h2_msg_hdr_name(TfwStr *hdr, TfwStr *out_name);
 void __h2_msg_hdr_val(TfwStr *hdr, TfwStr *out_val);
 void __http_msg_hdr_val(TfwStr *hdr, unsigned id, TfwStr *val, bool client);
 

tempesta_fw/msg.h

@@ -69,9 +69,6 @@ typedef struct {
  * @hb_len	- length of the message HTTP/2 headers block;
  * @hdrs_len	- accumulated length of message's decoded and parsed headers;
  * @hdrs_cnt	- count of all headers from message headers block;
- * @start_pos	- pointer to the beginning of decoded headers' buffer; used
- *		  as start point during exporting buffer pages to message's
- *		  target skb;
  * @__off	- offset for iterator reinitializing before next processing
  *		  stage;
  * @hdr		- descriptor of currently decoded header in target buffer;
@@ -90,7 +87,6 @@ typedef struct {
 	unsigned long	hb_len;
 	unsigned long	hdrs_len;
 	unsigned int	hdrs_cnt;
-	char		*start_pos;
 	char		__off[0];
 	TfwStr		hdr;
 	char		*pos;

tempesta_fw/pool.c

@@ -212,25 +212,36 @@ tfw_pool_free(TfwPool *p, void *ptr, size_t n)
 EXPORT_SYMBOL(tfw_pool_free);
 
 /**
- * Delete all chunks between the last (i.e. current in use) and the first one
+ * Delete all chunks between the first (i.e. current in use) and the last one
  * (which is the holder of @TfwPool itself). This is a garbage collection
  * procedure, which is applicable only for cases when pool is used for one
- * dynamically resizable (via @__tfw_pool_realloc()) instance.
+ * dynamically resizable (via @__tfw_pool_realloc()) instance. Also, this
+ * function can be used when caller definitely know, that all data behind the
+ * @ptr can be evicted (including the page which contains the @ptr).
  */
 void
-tfw_pool_clean(TfwPool *p)
+tfw_pool_clean(TfwPool *pool, void *ptr)
 {
 	TfwPoolChunk *c, *next;
 
-	if (!p)
+	if (!pool)
 		return;
 
-	for (c = p->curr->next; c; c = next) {
+	for (c = pool->curr->next; c; c = next) {
 		if (!(next = c->next))
 			break;
+		if (ptr) {
+			if ((char *)ptr < (char *)TFW_POOL_CHUNK_BASE(c)
+			    || (char *)ptr >= (char *)TFW_POOL_CHUNK_BASE(c)
+			    + c->off)
+			{
+				continue;
+			}
+			ptr = NULL;
+		}
 		tfw_pool_free_pages(TFW_POOL_CHUNK_BASE(c), c->order);
 	}
-	p->curr->next = c;
+	pool->curr->next = c;
 }
 EXPORT_SYMBOL(tfw_pool_clean);