[nft PATCH v2] expression: print sets and maps in pretty format

[nft PATCH v2] expression: print sets and maps in pretty format

[Arturo Borrero Gonzalez]

Print elements per line instead of all in a single line.
The elements which can be 'short' are printed 5 per line,
and others, like IPv4 addresses are printed 2 per line.

Example:

% nft list ruleset -nnn
table ip t {
	set s {
		type inet_service
		elements = { 1, 2, 3, 4, 10,
			     432, 433, 434, 435, 436,
			     437, 438, 439, 440, 441,
			     442, 443, 444, 445, 446,
			     447, 448, 449, 450, 12345 }
	}

	map m {
		type inet_service . iface_index : verdict
		elements = { 123 . "lo" : accept,
			     1234 . "lo" : accept,
			     12345 . "lo" : accept,
			     12346 . "lo" : accept,
			     12347 . "lo" : accept }
	}

	set s3 {
		type ipv4_addr
		elements = { 1.1.1.1, 2.2.2.2,
			     3.3.3.3 }
	}
}

NOTE: some testcases require updates because the output change.

Signed-off-by: Arturo Borrero Gonzalez <arturo@debian.org>
---
v2: align column using spaces rather than tabs.
    Cleanup unused variables and declarations.

 src/expression.c |   58 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/netlink.c    |    2 ++
 2 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/src/expression.c b/src/expression.c
index 45f3ed8..5defa63 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -742,10 +742,66 @@ struct expr *list_expr_alloc(const struct location *loc)
 	return compound_expr_alloc(loc, &list_expr_ops);
 }
 
+static const char *calculate_delim(const struct expr *expr, int *count)
+{
+	const char *newline = ",\n\t\t\t     ";
+	const char *singleline = ", ";
+
+	if (expr->set_flags & NFT_SET_ANONYMOUS)
+		return singleline;
+
+	if (!expr->dtype)
+		return newline;
+
+	switch (expr->dtype->type) {
+	case TYPE_NFPROTO:
+	case TYPE_INTEGER:
+	case TYPE_ARPOP:
+	case TYPE_INET_PROTOCOL:
+	case TYPE_INET_SERVICE:
+	case TYPE_TCP_FLAG:
+	case TYPE_DCCP_PKTTYPE:
+	case TYPE_MARK:
+	case TYPE_IFINDEX:
+	case TYPE_CLASSID:
+	case TYPE_UID:
+	case TYPE_GID:
+	case TYPE_CT_DIR:
+		if (*count < 5)
+			return singleline;
+		*count = 0;
+		break;
+	case TYPE_IPADDR:
+	case TYPE_CT_STATE:
+	case TYPE_CT_STATUS:
+	case TYPE_PKTTYPE:
+		if (*count < 2)
+			return singleline;
+		*count = 0;
+		break;
+
+	default:
+		break;
+	}
+
+	return newline;
+}
+
 static void set_expr_print(const struct expr *expr)
 {
+	const struct expr *i;
+	const char *d = "";
+	int count = 0;
+
 	printf("{ ");
-	compound_expr_print(expr, ", ");
+
+	list_for_each_entry(i, &expr->expressions, list) {
+		printf("%s", d);
+		expr_print(i);
+		count++;
+		d = calculate_delim(expr, &count);
+	}
+
 	printf(" }");
 }
 
diff --git a/src/netlink.c b/src/netlink.c
index 6fbb67d..59e8918 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -1730,6 +1730,8 @@ int netlink_get_setelems(struct netlink_ctx *ctx, const struct handle *h,
 	ctx->set = set;
 	set->init = set_expr_alloc(loc);
 	nftnl_set_elem_foreach(nls, list_setelem_cb, ctx);
+	set->init->set_flags = set->flags;
+	set->init->dtype = set->keytype;
 
 	if (!(set->flags & NFT_SET_INTERVAL))
 		list_expr_sort(&ctx->set->init->expressions);

Re: [nft PATCH v2] expression: print sets and maps in pretty format

[Pablo Neira Ayuso]

On Wed, Apr 26, 2017 at 11:05:55AM +0200, Arturo Borrero Gonzalez wrote:
> Print elements per line instead of all in a single line.
> The elements which can be 'short' are printed 5 per line,
> and others, like IPv4 addresses are printed 2 per line.
> 
> Example:
> 
> % nft list ruleset -nnn
> table ip t {
> 	set s {
> 		type inet_service
> 		elements = { 1, 2, 3, 4, 10,
> 			     432, 433, 434, 435, 436,
> 			     437, 438, 439, 440, 441,
> 			     442, 443, 444, 445, 446,
> 			     447, 448, 449, 450, 12345 }
> 	}
> 
> 	map m {
> 		type inet_service . iface_index : verdict
> 		elements = { 123 . "lo" : accept,
> 			     1234 . "lo" : accept,
> 			     12345 . "lo" : accept,
> 			     12346 . "lo" : accept,
> 			     12347 . "lo" : accept }
> 	}
> 
> 	set s3 {
> 		type ipv4_addr
> 		elements = { 1.1.1.1, 2.2.2.2,
> 			     3.3.3.3 }
> 	}
> }
> 
> NOTE: some testcases require updates because the output change.

I think this is a good starting point.

We can probably make a simple calculation based on the maximum length
of the string datatype, ie. strlen("255.255.255.255"), then use the
number of columns available and make a good guess on how much we can
fit in. It would still be something approximate.

Anyway, this can be refined later on.

Would you send me a v3 including the test updates? I ran them very
often here and I don't want to see them broken :).

Thanks!