BUG/MEDIUM: htx: Fully update HTX message when the block value is cha…

…nged

Everywhere the value length of a block is changed, calling the function
htx_set_blk_value_len(), the HTX message must be updated. But at many places,
because of the recent changes in the HTX structure, this update was only
partially done. tail_addr and head_addr values were not systematically updated.

In fact, the function htx_set_blk_value_len() was designed as an internal
function to the HTX API. And we used it from outside by convenience. But it is
really painfull and error prone to let the caller update the HTX message. So
now, we use the function htx_change_blk_value_len() wherever is possible. It
changes the value length of a block and updates the HTX message accordingly.

This patch must be backported to 2.0.

src/h2.c

@@ -736,8 +736,7 @@ int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *ms
 			if (tl > fs)
 				goto fail;
 
-			htx_set_blk_value_len(blk, tl);
-			htx->data += vl+2;
+			htx_change_blk_value_len(htx, blk, tl);
 			*(char *)(htx_get_blk_ptr(htx, blk) + bs + 0) = ';';
 			*(char *)(htx_get_blk_ptr(htx, blk) + bs + 1) = ' ';
 			memcpy(htx_get_blk_ptr(htx, blk) + bs + 2, list[ck].v.ptr, vl);

src/http_htx.c

@@ -461,10 +461,7 @@ int http_remove_header(struct htx *htx, struct http_hdr_ctx *ctx)
 	}
 	/* Update the block content and its len */
 	memmove(start, start+len, v.len-len);
-	htx_set_blk_value_len(blk, v.len-len);
-
-	/* Update HTX msg */
-	htx->data -= len;
+	htx_change_blk_value_len(htx, blk, v.len-len);
 
 	/* Finally update the ctx */
 	ctx->value.ptr = start;

src/htx.c

@@ -406,15 +406,8 @@ void htx_truncate(struct htx *htx, uint32_t offset)
 			offset -= sz;
 			continue;
 		}
-		if (type == HTX_BLK_DATA) {
-			htx_set_blk_value_len(blk, offset);
-			htx->data -= (sz - offset);
-
-			if (blk->addr+sz == htx->tail_addr)
-				htx->tail_addr -= offset;
-			else if (blk->addr+sz == htx->head_addr)
-				htx->head_addr -= offset;
-		}
+		if (type == HTX_BLK_DATA)
+			htx_change_blk_value_len(htx, blk, offset);
 		offset = 0;
 	}
 	while (blk)
@@ -522,14 +515,7 @@ struct htx_blk *htx_add_data_atonce(struct htx *htx, struct ist data)
 	/* Append data and update the block itself */
 	ptr = htx_get_blk_ptr(htx, tailblk);
 	memcpy(ptr+sz, data.ptr, len);
-	htx_set_blk_value_len(tailblk, sz+len);
-
-	/* Update HTTP message */
-	htx->data += len;
-	if (tailblk->addr+sz == htx->tail_addr)
-		htx->tail_addr += len;
-	else if (tailblk->addr+sz == htx->head_addr)
-		htx->head_addr += len;
+	htx_change_blk_value_len(htx, tailblk, sz+len);
 
 	if (data.len == len) {
 		blk = tailblk;
@@ -988,14 +974,7 @@ size_t htx_add_data(struct htx *htx, const struct ist data)
 	/* Append data and update the block itself */
 	ptr = htx_get_blk_ptr(htx, tailblk);
 	memcpy(ptr + sz, data.ptr, len);
-	htx_set_blk_value_len(tailblk, sz + len);
-
-	/* Update HTTP message */
-	htx->data += len;
-	if (tailblk->addr+sz == htx->tail_addr)
-		htx->tail_addr += len;
-	else if (tailblk->addr+sz == htx->head_addr)
-		htx->head_addr += len;
+	htx_change_blk_value_len(htx, tailblk, sz+len);
 
 	BUG_ON((int32_t)htx->tail_addr < 0);
 	BUG_ON((int32_t)htx->head_addr < 0);

src/proto_htx.c

@@ -4314,10 +4314,8 @@ static void htx_manage_client_side_cookies(struct stream *s, struct channel *req
 			hdr_end = (preserve_hdr ? del_from : hdr_beg);
 		}
 		if ((hdr_end - hdr_beg) != ctx.value.len) {
-			if (hdr_beg != hdr_end) {
-				htx_set_blk_value_len(ctx.blk, hdr_end - hdr_beg);
-				htx->data -= ctx.value.len - (hdr_end - hdr_beg);
-			}
+			if (hdr_beg != hdr_end)
+				htx_change_blk_value_len(htx, ctx.blk, hdr_end - hdr_beg);
 			else
 				http_remove_header(htx, &ctx);
 		}
@@ -4495,8 +4493,7 @@ static void htx_manage_server_side_cookies(struct stream *s, struct channel *res
 				next         += stripped_before;
 				hdr_end      += stripped_before;
 
-				htx_set_blk_value_len(ctx.blk, hdr_end - hdr_beg);
-				htx->data -= ctx.value.len - (hdr_end - hdr_beg);
+				htx_change_blk_value_len(htx, ctx.blk, hdr_end - hdr_beg);
 				ctx.value.len = hdr_end - hdr_beg;
 			}