diff mbox

[2/3,v5,nft] Simplify parser rule_spec tree

Message ID 20160817110010.28943-2-carlosfg@riseup.net
State Changes Requested
Delegated to: Pablo Neira
Headers show

Commit Message

Carlos Falgueras García Aug. 17, 2016, 11 a.m. UTC 
This patch separates the rule identification from the rule localization, so
the logic moves from the evaluator to the parser. This allows to revert the
patch "evaluate: improve rule managment checks"
(4176c7d30c2ff1b3f52468fc9c08b8df83f979a8) and saves a lot of code.

An specific error message is shown when user commits a syntax error, as
before this patch:

	$ nft add rule t c handle 3 ...
	<cmdline>:1:14-19: Error: Expected `position' or nothing
	add rule t c handle 3 ...
	             ^^^^^^

	$ nft delete rule t c position 3 ...
	<cmdline>:1:17-24: Error: syntax error, unexpected position, expecting handle
	delete rule t c position 3 ...
	                ^^^^^^^^

Also new boolean field is added to the structure 'parser_state' in order to
avoid print the error twice.

Signed-off-by: Carlos Falgueras García <carlosfg@riseup.net>
---
 include/parser.h   |  2 ++
 src/evaluate.c     | 68 +-----------------------------------------------------
 src/parser_bison.y | 61 ++++++++++++++++++++++++++++--------------------
 3 files changed, 39 insertions(+), 92 deletions(-)

Comments

Pablo Neira Ayuso Aug. 17, 2016, 3:04 p.m. UTC | #1 
On Wed, Aug 17, 2016 at 01:00:09PM +0200, Carlos Falgueras García wrote:
> diff --git a/include/parser.h b/include/parser.h
> index 92beab2..41e5340 100644
> --- a/include/parser.h
> +++ b/include/parser.h
> @@ -27,6 +27,8 @@ struct parser_state {
>  
>  	struct list_head		cmds;
>  	struct eval_ctx			ectx;
> +
> +	bool				err_recovering;

There must be a better way to handle this.

The error records are placed in a list, so it should be possible to
cancel the last error record.

Anyway, to keep this simple at this stage, please submit a patch
without this err_recovering and we fall back on the default error
reporting, OK?

Carlos, look:

1st) Finish the tests for the libnftnl cmp.
2nd) Come back to this patchset for nft (only after 1st is done).

OK? One thing at time :)
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diff mbox

Patch

diff --git a/include/parser.h b/include/parser.h
index 92beab2..41e5340 100644
--- a/include/parser.h
+++ b/include/parser.h
@@ -27,6 +27,8 @@  struct parser_state {
 
 	struct list_head		cmds;
 	struct eval_ctx			ectx;
+
+	bool				err_recovering;
 };
 
 extern void parser_init(struct parser_state *state, struct list_head *msgs);
diff --git a/src/evaluate.c b/src/evaluate.c
index 87f5a6d..2f94ac6 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -44,12 +44,6 @@  static const char *byteorder_names[] = {
 	__stmt_binary_error(ctx, &(s1)->location, NULL, fmt, ## args)
 #define cmd_error(ctx, fmt, args...) \
 	__stmt_binary_error(ctx, &(ctx->cmd)->location, NULL, fmt, ## args)
-#define handle_error(ctx, fmt, args...) \
-	__stmt_binary_error(ctx, &ctx->cmd->handle.handle.location, NULL, fmt, ## args)
-#define position_error(ctx, fmt, args...) \
-	__stmt_binary_error(ctx, &ctx->cmd->handle.position.location, NULL, fmt, ## args)
-#define handle_position_error(ctx, fmt, args...) \
-	__stmt_binary_error(ctx, &ctx->cmd->handle.handle.location, &ctx->cmd->handle.position.location, fmt, ## args)
 
 static int __fmtstring(3, 4) set_error(struct eval_ctx *ctx,
 				       const struct set *set,
@@ -2481,68 +2475,11 @@  static int set_evaluate(struct eval_ctx *ctx, struct set *set)
 	return 0;
 }
 
-static int rule_evaluate_cmd(struct eval_ctx *ctx)
-{
-	struct handle *handle = &ctx->cmd->handle;
-
-	/* allowed:
-	 * - insert [position] (no handle)
-	 * - add [position] (no handle)
-	 * - replace <handle> (no position)
-	 * - delete <handle> (no position)
-	 */
-
-	switch (ctx->cmd->op) {
-	case CMD_INSERT:
-		if (handle->handle.id && handle->position.id)
-			return handle_position_error(ctx, "use only `position'"
-						     " instead");
-
-		if (handle->handle.id)
-			return handle_error(ctx, "use `position' instead");
-		break;
-	case CMD_ADD:
-		if (handle->handle.id && handle->position.id)
-			return handle_position_error(ctx, "use only `position'"
-						     " instead");
-
-		if (handle->handle.id)
-			return handle_error(ctx, "use `position' instead");
-
-		break;
-	case CMD_REPLACE:
-		if (handle->handle.id && handle->position.id)
-			return handle_position_error(ctx, "use only `handle' "
-						     "instead");
-		if (handle->position.id)
-			return position_error(ctx, "use `handle' instead");
-		if (!handle->handle.id)
-			return cmd_error(ctx, "missing `handle'");
-		break;
-	case CMD_DELETE:
-		if (handle->handle.id && handle->position.id)
-			return handle_position_error(ctx, "use only `handle' "
-						     "instead");
-		if (handle->position.id)
-			return position_error(ctx, "use `handle' instead");
-		if (!handle->handle.id)
-			return cmd_error(ctx, "missing `handle'");
-		break;
-	default:
-		BUG("unkown command type %u\n", ctx->cmd->op);
-	}
-
-	return 0;
-}
-
 static int rule_evaluate(struct eval_ctx *ctx, struct rule *rule)
 {
 	struct stmt *stmt, *tstmt = NULL;
 	struct error_record *erec;
 
-	if (rule_evaluate_cmd(ctx) < 0)
-		return -1;
-
 	proto_ctx_init(&ctx->pctx, rule->handle.family);
 	memset(&ctx->ectx, 0, sizeof(ctx->ectx));
 
@@ -2723,11 +2660,8 @@  static int cmd_evaluate_delete(struct eval_ctx *ctx, struct cmd *cmd)
 			return ret;
 
 		return setelem_evaluate(ctx, &cmd->expr);
-	case CMD_OBJ_RULE:
-		if (rule_evaluate_cmd(ctx) < 0)
-			return -1;
-		/* fall through */
 	case CMD_OBJ_SET:
+	case CMD_OBJ_RULE:
 	case CMD_OBJ_CHAIN:
 	case CMD_OBJ_TABLE:
 		return 0;
diff --git a/src/parser_bison.y b/src/parser_bison.y
index e16b8a3..93c283f 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -42,12 +42,14 @@  void parser_init(struct parser_state *state, struct list_head *msgs)
 	state->msgs = msgs;
 	state->scopes[0] = scope_init(&state->top_scope, NULL);
 	state->ectx.msgs = msgs;
+	state->err_recovering = false;
 }
 
 static void yyerror(struct location *loc, void *scanner,
 		    struct parser_state *state, const char *s)
 {
-	erec_queue(error(loc, "%s", s), state->msgs);
+	if (!state->err_recovering)
+		erec_queue(error(loc, "%s", s), state->msgs);
 }
 
 static struct scope *current_scope(const struct parser_state *state)
@@ -425,15 +427,12 @@  static void location_update(struct location *loc, struct location *rhs, int n)
 %type <cmd>			base_cmd add_cmd replace_cmd create_cmd insert_cmd delete_cmd list_cmd flush_cmd rename_cmd export_cmd monitor_cmd describe_cmd
 %destructor { cmd_free($$); }	base_cmd add_cmd replace_cmd create_cmd insert_cmd delete_cmd list_cmd flush_cmd rename_cmd export_cmd monitor_cmd describe_cmd
 
-%type <handle>			table_spec chain_spec chain_identifier ruleid_spec ruleset_spec
-%destructor { handle_free(&$$); } table_spec chain_spec chain_identifier ruleid_spec ruleset_spec
+%type <handle>			table_spec chain_spec chain_identifier ruleid_spec handle_spec position_spec rule_position ruleset_spec
+%destructor { handle_free(&$$); } table_spec chain_spec chain_identifier ruleid_spec handle_spec position_spec rule_position ruleset_spec
 %type <handle>			set_spec set_identifier
 %destructor { handle_free(&$$); } set_spec set_identifier
 %type <val>			family_spec family_spec_explicit chain_policy prio_spec
 
-%type <handle_spec>		handle_spec
-%type <position_spec>		position_spec
-
 %type <string>			dev_spec
 %destructor { xfree($$); }	dev_spec
 
@@ -720,11 +719,11 @@  add_cmd			:	TABLE		table_spec
 				close_scope(state);
 				$$ = cmd_alloc(CMD_ADD, CMD_OBJ_CHAIN, &$2, &@$, $5);
 			}
-			|	RULE		ruleid_spec	rule
+			|	RULE		rule_position	rule
 			{
 				$$ = cmd_alloc(CMD_ADD, CMD_OBJ_RULE, &$2, &@$, $3);
 			}
-			|	/* empty */	ruleid_spec	rule
+			|	/* empty */	rule_position	rule
 			{
 				$$ = cmd_alloc(CMD_ADD, CMD_OBJ_RULE, &$1, &@$, $2);
 			}
@@ -779,7 +778,7 @@  create_cmd		:	TABLE		table_spec
 			}
 			;
 
-insert_cmd		:	RULE		ruleid_spec	rule
+insert_cmd		:	RULE		rule_position	rule
 			{
 				$$ = cmd_alloc(CMD_INSERT, CMD_OBJ_RULE, &$2, &@$, $3);
 			}
@@ -1252,38 +1251,50 @@  set_identifier		:	identifier
 			}
 			;
 
-handle_spec		:	/* empty */
+handle_spec		:	HANDLE		NUM
 			{
-				memset(&$$, 0, sizeof($$));
+				$$.handle.location	= @$;
+				$$.handle.id		= $2;
 			}
-			|	HANDLE		NUM
+			;
+
+position_spec		:	POSITION	NUM
 			{
-				memset(&$$, 0, sizeof($$));
-				$$.location	= @$;
-				$$.id		= $2;
+				$$.position.location	= @$;
+				$$.position.id		= $2;
 			}
 			;
 
-position_spec		:	/* empty */
+rule_position		:	chain_spec
 			{
-				memset(&$$, 0, sizeof($$));
+				$$ = $1;
 			}
-			|	POSITION	NUM
+			|	chain_spec position_spec
 			{
-				memset(&$$, 0, sizeof($$));
-				$$.location	= @$;
-				$$.id		= $2;
+				$$ = $1;
+				handle_merge(&$$, &$2);
+			}
+			|	chain_spec HANDLE err_recovering error
+			{
+				erec_queue(error(&@2, "Expected `position' or nothing"),
+					   state->msgs);
+				state->err_recovering = false;
+				$$ = $1;
 			}
 			;
 
-ruleid_spec		:	chain_spec	handle_spec	position_spec
+ruleid_spec		:	chain_spec handle_spec
 			{
-				$$		= $1;
-				$$.handle	= $2;
-				$$.position	= $3;
+				$$ = $1;
+				handle_merge(&$$, &$2);
 			}
 			;
 
+err_recovering	:	/* empty */
+			{
+				state->err_recovering = true;
+			};
+
 comment_spec		:	COMMENT		string
 			{
 				if (strlen($2) > UDATA_COMMENT_MAXLEN) {