[PATCH] comment: Add translation to nft

[PATCH] comment: Add translation to nft

[Shivani Bhardwaj]

Add translation for match comment to nftables.

Example:

$ sudo iptables-translate -A INPUT -s 192.168.0.0 -m comment --comment "A privatized IP block"
nft add rule ip filter INPUT ip saddr 192.168.0.0 counter comment \"A privatized IP block\"

Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
---
 extensions/libxt_comment.c | 13 +++++++++++++
 iptables/nft-ipv4.c        | 17 +++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/extensions/libxt_comment.c b/extensions/libxt_comment.c
index 6ed2ff9..e80336c 100644
--- a/extensions/libxt_comment.c
+++ b/extensions/libxt_comment.c
@@ -48,6 +48,18 @@ comment_save(const void *ip, const struct xt_entry_match *match)
 	xtables_save_string(commentinfo->comment);
 }
 
+static int
+comment_xlate(const struct xt_entry_match *match,
+	      struct xt_buf *buf, int numeric)
+{
+	struct xt_comment_info *commentinfo = (void *)match->data;
+
+	commentinfo->comment[XT_MAX_COMMENT_LEN-1] = '\0';
+	xt_buf_add(buf, "comment \\\"%s\\\" ", commentinfo->comment);
+
+	return 1;
+}
+
 static struct xtables_match comment_match = {
 	.family		= NFPROTO_UNSPEC,
 	.name		= "comment",
@@ -59,6 +71,7 @@ static struct xtables_match comment_match = {
 	.save 		= comment_save,
 	.x6_parse	= xtables_option_parse,
 	.x6_options	= comment_opts,
+	.xlate		= comment_xlate,
 };
 
 void _init(void)
diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c
index ede8f17..612b4f6 100644
--- a/iptables/nft-ipv4.c
+++ b/iptables/nft-ipv4.c
@@ -433,6 +433,7 @@ static int nft_ipv4_xlate(const void *data, struct xt_buf *buf)
 {
 	const struct iptables_command_state *cs = data;
 	int ret;
+	bool comm = false;
 
 	if (cs->fw.ip.iniface[0] != '\0') {
 		xt_buf_add(buf, "iifname %s%s ",
@@ -477,12 +478,24 @@ static int nft_ipv4_xlate(const void *data, struct xt_buf *buf)
 			   inet_ntoa(cs->fw.ip.dst));
 	}
 
+	/*
+	 * Add counter for match comment as prefix
+	 */
+	if (strcmp(cs->matches->match->name, "comment") == 0) {
+		comm = true;
+		xt_buf_add(buf, "counter ");
+	}
+
 	ret = xlate_matches(cs, buf);
 	if (!ret)
 		return ret;
 
-	/* Always add counters per rule, as in iptables */
-	xt_buf_add(buf, "counter ");
+	/*
+	 * Always add counters per rule, as in iptables
+	 * except for the match comment
+	 */
+	if (!comm)
+		xt_buf_add(buf, "counter ");
 
 	ret = xlate_action(cs, !!(cs->fw.ip.flags & IPT_F_GOTO), buf);
 
-- 
1.9.1

Re: [PATCH] comment: Add translation to nft

[Pablo Neira Ayuso]

On Mon, Feb 01, 2016 at 11:31:52AM +0530, Shivani Bhardwaj wrote:
> Add translation for match comment to nftables.
> 
> Example:
> 
> $ sudo iptables-translate -A INPUT -s 192.168.0.0 -m comment --comment "A privatized IP block"
> nft add rule ip filter INPUT ip saddr 192.168.0.0 counter comment \"A privatized IP block\"

Could you rework this patch on top of these:

http://patchwork.ozlabs.org/patch/576671/
http://patchwork.ozlabs.org/patch/576673/
http://patchwork.ozlabs.org/patch/576672/

I have only compile-tested them.

[PATCH] comment: Add translation to nft

[Shivani Bhardwaj]

Add translation for match comment to nftables.

Example:

$ sudo iptables-translate -A INPUT -s 192.168.0.0 -m comment --comment "A privatized IP block"
nft add rule ip filter INPUT ip saddr 192.168.0.0 counter comment \"A privatized IP block\"

Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
---
 extensions/libxt_comment.c | 14 ++++++++++++++
 iptables/nft-ipv4.c        | 17 +++++++++++++++--
 iptables/nft-ipv6.c        | 17 +++++++++++++++--
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/extensions/libxt_comment.c b/extensions/libxt_comment.c
index 6ed2ff9..0461924 100644
--- a/extensions/libxt_comment.c
+++ b/extensions/libxt_comment.c
@@ -48,6 +48,19 @@ comment_save(const void *ip, const struct xt_entry_match *match)
 	xtables_save_string(commentinfo->comment);
 }
 
+static int
+comment_xlate(const struct xt_entry_match *match,
+	      struct xt_xlate *xl, int numeric)
+{
+	struct xt_comment_info *commentinfo = (void *)match->data;
+
+	commentinfo->comment[XT_MAX_COMMENT_LEN-1] = '\0';
+	xt_xlate_add_comment(xl, commentinfo->comment);
+	xt_xlate_add(xl, "comment \\\"%s\\\" ", commentinfo->comment);
+
+	return 1;
+}
+
 static struct xtables_match comment_match = {
 	.family		= NFPROTO_UNSPEC,
 	.name		= "comment",
@@ -59,6 +72,7 @@ static struct xtables_match comment_match = {
 	.save 		= comment_save,
 	.x6_parse	= xtables_option_parse,
 	.x6_options	= comment_opts,
+	.xlate		= comment_xlate,
 };
 
 void _init(void)
diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c
index 5e2857d..f816a8a 100644
--- a/iptables/nft-ipv4.c
+++ b/iptables/nft-ipv4.c
@@ -433,6 +433,7 @@ static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl)
 {
 	const struct iptables_command_state *cs = data;
 	int ret;
+	bool comm = false;
 
 	if (cs->fw.ip.iniface[0] != '\0') {
 		xt_xlate_add(xl, "iifname %s%s ",
@@ -477,12 +478,24 @@ static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl)
 			   inet_ntoa(cs->fw.ip.dst));
 	}
 
+	/*
+	 * Add counter for match comment as prefix
+	 */
+	if (strcmp(cs->matches->match->name, "comment") == 0) {
+		comm = true;
+		xt_xlate_add(xl, "counter ");
+	}
+
 	ret = xlate_matches(cs, xl);
 	if (!ret)
 		return ret;
 
-	/* Always add counters per rule, as in iptables */
-	xt_xlate_add(xl, "counter ");
+	/*
+	 * Always add counters per rule, as in iptables
+	 * except for match comment
+	 */
+	if (!comm)
+		xt_xlate_add(xl, "counter ");
 
 	ret = xlate_action(cs, !!(cs->fw.ip.flags & IPT_F_GOTO), xl);
 
diff --git a/iptables/nft-ipv6.c b/iptables/nft-ipv6.c
index 0ee7957..edc572c 100644
--- a/iptables/nft-ipv6.c
+++ b/iptables/nft-ipv6.c
@@ -393,6 +393,7 @@ static int nft_ipv6_xlate(const void *data, struct xt_xlate *xl)
 {
 	const struct iptables_command_state *cs = data;
 	int ret;
+	bool comm = false;
 
 	if (cs->fw6.ipv6.iniface[0] != '\0') {
 		xt_xlate_add(xl, "iifname %s%s ",
@@ -428,12 +429,24 @@ static int nft_ipv6_xlate(const void *data, struct xt_xlate *xl)
 	xlate_ipv6_addr("ip6 daddr", &cs->fw6.ipv6.dst,
 			cs->fw6.ipv6.invflags & IP6T_INV_DSTIP, xl);
 
+	/*
+	 * Add counter as prefix for match comment
+	 */
+	if (strcmp(cs->matches->match->name, "comment") == 0) {
+		comm = true;
+		xt_xlate_add(xl, "counter ");
+	}
+
 	ret = xlate_matches(cs, xl);
 	if (!ret)
 		return ret;
 
-	/* Always add counters per rule, as in iptables */
-	xt_xlate_add(xl, "counter ");
+	/*
+	 * Always add counters per rule, as in iptables
+	 * except for match comment
+	 */
+	if (!comm)
+		xt_xlate_add(xl, "counter ");
 
 	ret = xlate_action(cs, !!(cs->fw6.ipv6.flags & IP6T_F_GOTO), xl);
 
-- 
1.9.1

Re: [PATCH] comment: Add translation to nft

[Pablo Neira Ayuso]

On Tue, Feb 16, 2016 at 01:40:28AM +0530, Shivani Bhardwaj wrote:
> Add translation for match comment to nftables.
> 
> Example:
> 
> $ sudo iptables-translate -A INPUT -s 192.168.0.0 -m comment --comment "A privatized IP block"
> nft add rule ip filter INPUT ip saddr 192.168.0.0 counter comment \"A privatized IP block\"
> 
> Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
> ---
>  extensions/libxt_comment.c | 14 ++++++++++++++
>  iptables/nft-ipv4.c        | 17 +++++++++++++++--
>  iptables/nft-ipv6.c        | 17 +++++++++++++++--
>  3 files changed, 44 insertions(+), 4 deletions(-)
> 
> diff --git a/extensions/libxt_comment.c b/extensions/libxt_comment.c
> index 6ed2ff9..0461924 100644
> --- a/extensions/libxt_comment.c
> +++ b/extensions/libxt_comment.c
> @@ -48,6 +48,19 @@ comment_save(const void *ip, const struct xt_entry_match *match)
>  	xtables_save_string(commentinfo->comment);
>  }
>  
> +static int
> +comment_xlate(const struct xt_entry_match *match,
> +	      struct xt_xlate *xl, int numeric)
> +{
> +	struct xt_comment_info *commentinfo = (void *)match->data;
> +
> +	commentinfo->comment[XT_MAX_COMMENT_LEN-1] = '\0';
> +	xt_xlate_add_comment(xl, commentinfo->comment);
> +	xt_xlate_add(xl, "comment \\\"%s\\\" ", commentinfo->comment);

You don't need this line above.

The idea after xt_xlate_add_comment() is that, from the core, you
print the comment in the right position.

See below.

> +
> +	return 1;
> +}
> +
>  static struct xtables_match comment_match = {
>  	.family		= NFPROTO_UNSPEC,
>  	.name		= "comment",
> @@ -59,6 +72,7 @@ static struct xtables_match comment_match = {
>  	.save 		= comment_save,
>  	.x6_parse	= xtables_option_parse,
>  	.x6_options	= comment_opts,
> +	.xlate		= comment_xlate,
>  };
>  
>  void _init(void)
> diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c
> index 5e2857d..f816a8a 100644
> --- a/iptables/nft-ipv4.c
> +++ b/iptables/nft-ipv4.c
> @@ -433,6 +433,7 @@ static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl)
>  {
>  	const struct iptables_command_state *cs = data;
>  	int ret;
> +	bool comm = false;
>  
>  	if (cs->fw.ip.iniface[0] != '\0') {
>  		xt_xlate_add(xl, "iifname %s%s ",
> @@ -477,12 +478,24 @@ static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl)
>  			   inet_ntoa(cs->fw.ip.dst));
>  	}
>  
> +	/*
> +	 * Add counter for match comment as prefix
> +	 */
> +	if (strcmp(cs->matches->match->name, "comment") == 0) {
> +		comm = true;
> +		xt_xlate_add(xl, "counter ");
> +	}

After my update you don't need to check if the match is comment
anymore, instead you can check if xl->comment is set, if so you print
the counter in first place to make sure it comes before the comment.

Please, send a v2. Thanks.

[PATCH] comment: Add translation to nft

[Shivani Bhardwaj]

Add translation for match comment to nftables.
This patch also adds the relevant infrastructure for carrying out
the translation.

Example:

$ sudo iptables-translate -A INPUT -s 192.168.0.0 -m comment --comment "A privatized IP block"
nft add rule ip filter INPUT ip saddr 192.168.0.0 counter comment \"A privatized IP block\"

Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
---
 extensions/libxt_comment.c | 13 +++++++++++++
 include/xtables.h          |  1 +
 iptables/nft-ipv4.c        |  6 ++++++
 iptables/nft-ipv6.c        |  6 ++++++
 libxtables/xtables.c       |  5 +++++
 5 files changed, 31 insertions(+)

diff --git a/extensions/libxt_comment.c b/extensions/libxt_comment.c
index 6ed2ff9..464ca09 100644
--- a/extensions/libxt_comment.c
+++ b/extensions/libxt_comment.c
@@ -48,6 +48,18 @@ comment_save(const void *ip, const struct xt_entry_match *match)
 	xtables_save_string(commentinfo->comment);
 }
 
+static int
+comment_xlate(const struct xt_entry_match *match,
+	      struct xt_xlate *xl, int numeric)
+{
+	struct xt_comment_info *commentinfo = (void *)match->data;
+
+	commentinfo->comment[XT_MAX_COMMENT_LEN-1] = '\0';
+        xt_xlate_add_comment(xl, commentinfo->comment);
+
+	return 1;
+}
+
 static struct xtables_match comment_match = {
 	.family		= NFPROTO_UNSPEC,
 	.name		= "comment",
@@ -59,6 +71,7 @@ static struct xtables_match comment_match = {
 	.save 		= comment_save,
 	.x6_parse	= xtables_option_parse,
 	.x6_options	= comment_opts,
+	.xlate		= comment_xlate,
 };
 
 void _init(void)
diff --git a/include/xtables.h b/include/xtables.h
index 6fd3bdf..e219c9f 100644
--- a/include/xtables.h
+++ b/include/xtables.h
@@ -574,6 +574,7 @@ struct xt_xlate *xt_xlate_alloc(int size);
 void xt_xlate_free(struct xt_xlate *xl);
 void xt_xlate_add(struct xt_xlate *xl, const char *fmt, ...);
 void xt_xlate_add_comment(struct xt_xlate *xl, const char *comment);
+const char *xt_xlate_get_comment(struct xt_xlate *xl);
 const char *xt_xlate_get(struct xt_xlate *xl);
 
 #ifdef XTABLES_INTERNAL
diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c
index 5e2857d..3c41755 100644
--- a/iptables/nft-ipv4.c
+++ b/iptables/nft-ipv4.c
@@ -433,6 +433,7 @@ static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl)
 {
 	const struct iptables_command_state *cs = data;
 	int ret;
+	const char *comment;
 
 	if (cs->fw.ip.iniface[0] != '\0') {
 		xt_xlate_add(xl, "iifname %s%s ",
@@ -484,6 +485,11 @@ static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl)
 	/* Always add counters per rule, as in iptables */
 	xt_xlate_add(xl, "counter ");
 
+	comment = xt_xlate_get_comment(xl);
+
+	if (strcmp(comment, ""))
+		xt_xlate_add(xl, "comment \\\"%s\\\" ", comment);
+
 	ret = xlate_action(cs, !!(cs->fw.ip.flags & IPT_F_GOTO), xl);
 
 	return ret;
diff --git a/iptables/nft-ipv6.c b/iptables/nft-ipv6.c
index bbf289b..8912f1d 100644
--- a/iptables/nft-ipv6.c
+++ b/iptables/nft-ipv6.c
@@ -393,6 +393,7 @@ static int nft_ipv6_xlate(const void *data, struct xt_xlate *xl)
 {
 	const struct iptables_command_state *cs = data;
 	int ret;
+	const char *comment;
 
 	if (cs->fw6.ipv6.iniface[0] != '\0') {
 		xt_xlate_add(xl, "iifname %s%s ",
@@ -435,6 +436,11 @@ static int nft_ipv6_xlate(const void *data, struct xt_xlate *xl)
 	/* Always add counters per rule, as in iptables */
 	xt_xlate_add(xl, "counter ");
 
+	comment = xt_xlate_get_comment(xl);
+
+	if (strcmp(comment, ""))
+		xt_xlate_add(xl, "comment \\\"%s\\\" ", comment);
+
 	ret = xlate_action(cs, !!(cs->fw6.ipv6.flags & IP6T_F_GOTO), xl);
 
 	return ret;
diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index c4b86f5..decd7be 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -2045,6 +2045,11 @@ void xt_xlate_add_comment(struct xt_xlate *xl, const char *comment)
 	xl->comment[NFT_USERDATA_MAXLEN - 1] = '\0';
 }
 
+const char *xt_xlate_get_comment(struct xt_xlate *xl)
+{
+	return xl->comment;
+}
+
 const char *xt_xlate_get(struct xt_xlate *xl)
 {
 	return xl->buf.data;
-- 
1.9.1

Re: [PATCH] comment: Add translation to nft

[Pablo Neira Ayuso]

On Wed, Feb 24, 2016 at 01:19:34AM +0530, Shivani Bhardwaj wrote:
> Add translation for match comment to nftables.
> This patch also adds the relevant infrastructure for carrying out
> the translation.
> 
> Example:
> 
> $ sudo iptables-translate -A INPUT -s 192.168.0.0 -m comment --comment "A privatized IP block"
> nft add rule ip filter INPUT ip saddr 192.168.0.0 counter comment \"A privatized IP block\"

Applied with some changes, see final commit pushed upstream for updates.

Thanks.