From 3bd3af273ccfa550ed50ad19d4bcd04a29b88f5b Mon Sep 17 00:00:00 2001

From: Phil Sutter <phil@nwl.cc>

Date: Thu, 29 Apr 2021 15:28:59 +0200

Subject: [PATCH] extensions: SECMARK: Implement revision 1

The changed data structure for communication with kernel allows to

exclude the field 'secid' which is populated on kernel side. Thus

this fixes the formerly always failing extension comparison breaking

rule check and rule delete by content.

Signed-off-by: Phil Sutter <phil@nwl.cc>

(cherry picked from commit 616800af0da86d151cb695f1376d5ec6ede6fa72)

---

 extensions/libxt_SECMARK.c           | 90 +++++++++++++++++++++-------

 extensions/libxt_SECMARK.t           |  4 ++

 include/linux/netfilter/xt_SECMARK.h |  6 ++

 3 files changed, 80 insertions(+), 20 deletions(-)

 create mode 100644 extensions/libxt_SECMARK.t

diff --git a/extensions/libxt_SECMARK.c b/extensions/libxt_SECMARK.c

index 6ba8606355daa..24249bd618ffe 100644

--- a/extensions/libxt_SECMARK.c

+++ b/extensions/libxt_SECMARK.c

@@ -29,6 +29,13 @@ static const struct xt_option_entry SECMARK_opts[] = {

 	XTOPT_TABLEEND,

 };

+static const struct xt_option_entry SECMARK_opts_v1[] = {

+	{.name = "selctx", .id = O_SELCTX, .type = XTTYPE_STRING,

+	 .flags = XTOPT_MAND | XTOPT_PUT,

+	 XTOPT_POINTER(struct xt_secmark_target_info_v1, secctx)},

+	XTOPT_TABLEEND,

+};

+

 static void SECMARK_parse(struct xt_option_call *cb)

 {

 	struct xt_secmark_target_info *info = cb->data;

@@ -37,15 +44,23 @@ static void SECMARK_parse(struct xt_option_call *cb)

 	info->mode = SECMARK_MODE_SEL;

 }

-static void print_secmark(const struct xt_secmark_target_info *info)

+static void SECMARK_parse_v1(struct xt_option_call *cb)

+{

+	struct xt_secmark_target_info_v1 *info = cb->data;

+

+	xtables_option_parse(cb);

+	info->mode = SECMARK_MODE_SEL;

+}

+

+static void print_secmark(__u8 mode, const char *secctx)

 {

-	switch (info->mode) {

+	switch (mode) {

 	case SECMARK_MODE_SEL:

-		printf("selctx %s", info->secctx);

+		printf("selctx %s", secctx);

 		break;

-	

+

 	default:

-		xtables_error(OTHER_PROBLEM, PFX "invalid mode %hhu\n", info->mode);

+		xtables_error(OTHER_PROBLEM, PFX "invalid mode %hhu\n", mode);

 	}

 }

@@ -56,7 +71,17 @@ static void SECMARK_print(const void *ip, const struct xt_entry_target *target,

 		(struct xt_secmark_target_info*)(target)->data;

 	printf(" SECMARK ");

-	print_secmark(info);

+	print_secmark(info->mode, info->secctx);

+}

+

+static void SECMARK_print_v1(const void *ip,

+			     const struct xt_entry_target *target, int numeric)

+{

+	const struct xt_secmark_target_info_v1 *info =

+		(struct xt_secmark_target_info_v1 *)(target)->data;

+

+	printf(" SECMARK ");

+	print_secmark(info->mode, info->secctx);

 }

 static void SECMARK_save(const void *ip, const struct xt_entry_target *target)

@@ -65,24 +90,49 @@ static void SECMARK_save(const void *ip, const struct xt_entry_target *target)

 		(struct xt_secmark_target_info*)target->data;

 	printf(" --");

-	print_secmark(info);

+	print_secmark(info->mode, info->secctx);

 }

-static struct xtables_target secmark_target = {

-	.family		= NFPROTO_UNSPEC,

-	.name		= "SECMARK",

-	.version	= XTABLES_VERSION,

-	.revision	= 0,

-	.size		= XT_ALIGN(sizeof(struct xt_secmark_target_info)),

-	.userspacesize	= XT_ALIGN(sizeof(struct xt_secmark_target_info)),

-	.help		= SECMARK_help,

-	.print		= SECMARK_print,

-	.save		= SECMARK_save,

-	.x6_parse	= SECMARK_parse,

-	.x6_options	= SECMARK_opts,

+static void SECMARK_save_v1(const void *ip,

+			    const struct xt_entry_target *target)

+{

+	const struct xt_secmark_target_info_v1 *info =

+		(struct xt_secmark_target_info_v1 *)target->data;

+

+	printf(" --");

+	print_secmark(info->mode, info->secctx);

+}

+

+static struct xtables_target secmark_tg_reg[] = {

+	{

+		.family		= NFPROTO_UNSPEC,

+		.name		= "SECMARK",

+		.version	= XTABLES_VERSION,

+		.revision	= 0,

+		.size		= XT_ALIGN(sizeof(struct xt_secmark_target_info)),

+		.userspacesize	= XT_ALIGN(sizeof(struct xt_secmark_target_info)),

+		.help		= SECMARK_help,

+		.print		= SECMARK_print,

+		.save		= SECMARK_save,

+		.x6_parse	= SECMARK_parse,

+		.x6_options	= SECMARK_opts,

+	},

+	{

+		.family		= NFPROTO_UNSPEC,

+		.name		= "SECMARK",

+		.version	= XTABLES_VERSION,

+		.revision	= 1,

+		.size		= XT_ALIGN(sizeof(struct xt_secmark_target_info_v1)),

+		.userspacesize	= XT_ALIGN(offsetof(struct xt_secmark_target_info_v1, secid)),

+		.help		= SECMARK_help,

+		.print		= SECMARK_print_v1,

+		.save		= SECMARK_save_v1,

+		.x6_parse	= SECMARK_parse_v1,

+		.x6_options	= SECMARK_opts_v1,

+	}

 };

 void _init(void)

 {

-	xtables_register_target(&secmark_target);

+	xtables_register_targets(secmark_tg_reg, ARRAY_SIZE(secmark_tg_reg));

 }

diff --git a/extensions/libxt_SECMARK.t b/extensions/libxt_SECMARK.t

new file mode 100644

index 0000000000000..39d4c09348bf4

--- /dev/null

+++ b/extensions/libxt_SECMARK.t

@@ -0,0 +1,4 @@

+:INPUT,FORWARD,OUTPUT

+*security

+-j SECMARK --selctx system_u:object_r:firewalld_exec_t:s0;=;OK

+-j SECMARK;;FAIL

diff --git a/include/linux/netfilter/xt_SECMARK.h b/include/linux/netfilter/xt_SECMARK.h

index 989092bd6274b..31760a286a854 100644

--- a/include/linux/netfilter/xt_SECMARK.h

+++ b/include/linux/netfilter/xt_SECMARK.h

@@ -19,4 +19,10 @@ struct xt_secmark_target_info {

 	char secctx[SECMARK_SECCTX_MAX];

 };

+struct xt_secmark_target_info_v1 {

+	__u8 mode;

+	char secctx[SECMARK_SECCTX_MAX];

+	__u32 secid;

+};

+

 #endif /*_XT_SECMARK_H_target */

-- 

2.31.1