[PATCHv3] extensions: libipt_icmp: Add translation to nft
diff mbox

Message ID 20160307212141.GA10594@sonyv
State Changes Requested
Delegated to: Pablo Neira
Headers show

Commit Message

Laura Garcia Liebana March 7, 2016, 9:21 p.m. UTC
Add translation for icmp to nftables. Not supported types in nftables
are: any, network-unreachable, host-unreachable, protocol-unreachable,
port-unreachable, fragmentation-needed, source-route-failed,
network-unknown, host-unknown, network-prohibited, host-prohibited,
TOS-network-unreachable, TOS-host-unreachable, communication-prohibited,
host-precedence-violation, precedence-cutoff, network-redirect,
host-redirect, TOS-network-redirect, TOS-host-redirect,
router-advertisement, router-solicitation, ttl-zero-during-transit,
ttl-zero-during-reassembly, ip-header-bad and required-option-missing.

Examples:

$ sudo iptables-translate -t filter -A INPUT -m icmp --icmp-type echo-reply -j LOG
nft add rule ip filter INPUT icmp type echo-reply counter log level warn

$ sudo iptables-translate -t filter -A INPUT -m icmp --icmp-type 3 -j LOG
nft add rule ip filter INPUT icmp type destination-unreachable counter log level warn

$ sudo iptables-translate -t filter -A INPUT -m icmp ! --icmp-type 3 -j LOG
nft add rule ip filter INPUT icmp type != destination-unreachable counter log level warn

Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
---
v2:
	- Detection of not supported types in nftables, as Shivani suggested.
v3:
	- Fix array iteration protection.

 extensions/libipt_icmp.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

Comments

Pablo Neira Ayuso March 8, 2016, 10:53 a.m. UTC | #1
On Mon, Mar 07, 2016 at 10:21:44PM +0100, Laura Garcia Liebana wrote:
> Add translation for icmp to nftables. Not supported types in nftables

These are actually icmp codes that we don't support yet, right?

> are: any, network-unreachable, host-unreachable, protocol-unreachable,
> port-unreachable, fragmentation-needed, source-route-failed,
> network-unknown, host-unknown, network-prohibited, host-prohibited,
> TOS-network-unreachable, TOS-host-unreachable, communication-prohibited,
> host-precedence-violation, precedence-cutoff, network-redirect,
> host-redirect, TOS-network-redirect, TOS-host-redirect,
> router-advertisement, router-solicitation, ttl-zero-during-transit,
> ttl-zero-during-reassembly, ip-header-bad and required-option-missing.
> 
> Examples:
> 
> $ sudo iptables-translate -t filter -A INPUT -m icmp --icmp-type echo-reply -j LOG
> nft add rule ip filter INPUT icmp type echo-reply counter log level warn
> 
> $ sudo iptables-translate -t filter -A INPUT -m icmp --icmp-type 3 -j LOG
> nft add rule ip filter INPUT icmp type destination-unreachable counter log level warn
> 
> $ sudo iptables-translate -t filter -A INPUT -m icmp ! --icmp-type 3 -j LOG
> nft add rule ip filter INPUT icmp type != destination-unreachable counter log level warn
> 
> Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
> ---
> v2:
> 	- Detection of not supported types in nftables, as Shivani suggested.
> v3:
> 	- Fix array iteration protection.
> 
>  extensions/libipt_icmp.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/extensions/libipt_icmp.c b/extensions/libipt_icmp.c
> index 666e7da..2c8be87 100644
> --- a/extensions/libipt_icmp.c
> +++ b/extensions/libipt_icmp.c
> @@ -218,7 +218,7 @@ static void print_icmptype(uint8_t type,
>  }
>  
>  static void icmp_print(const void *ip, const struct xt_entry_match *match,
> -                       int numeric)
> +		       int numeric)

I think this change doesn't below this patch.

>  {
>  	const struct ipt_icmp *icmp = (struct ipt_icmp *)match->data;
>  
> @@ -249,6 +249,52 @@ static void icmp_save(const void *ip, const struct xt_entry_match *match)
>  	}
>  }
>  
> +static unsigned int type_xlate_print(struct xt_xlate *xl, unsigned int icmptype,
> +			     unsigned int code_min, unsigned int code_max)
                       ^^^^^^

This should be aligned with the line above:

static unsigned int type_xlate_print(struct xt_xlate *xl, unsigned int icmptype,
                                     unsigned int code_min,
                                     unsigned int code_max)

> +{
> +	unsigned int i;
> +
> +	if (code_min == code_max)
> +		return 0;
> +
> +	switch (icmptype) {
> +	case 0xFF:

You can skip the 0xff case by adding nothing.

> +	case 9:
> +	case 10:

You can send me a two-liner for this for nft, so we don't need this I
think.

> +		return 0;
> +	default:
> +		for (i = 0; i < ARRAY_SIZE(icmp_codes); ++i)
> +			if (icmp_codes[i].type == icmptype &&
> +			    icmp_codes[i].code_min == code_min &&
> +			    icmp_codes[i].code_max == code_max)
> +				break;
> +
> +		if (i != ARRAY_SIZE(icmp_codes))
> +			xt_xlate_add(xl, icmp_codes[i].name);
> +		else
> +			return 0;
> +	}
> +
> +	return 1;
> +}
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Piyush Pangtey March 9, 2016, 7:05 a.m. UTC | #2
Hello Pablo,

I would require some guidance regarding the libxt_multiport translation in nft.

If the translation is over ip4 family :
$ iptables-translate -A INPUT -p tcp -m multiport --ports 3:4  -j ACCEPT
nft add rule ip filter INPUT ip protocol tcp dport { 3-4 } tcp sport { 3-4 } counter accept
		             ^^^^^^^^^^^
			     this causes problem.
Similarly for ipv6 :
$ ip6tables-translate -A input -p tcp -m multiport --dports 1024:2048,2049:3333 -j ACCEPT
nft add rule ip6 filter input meta l4proto tcp dport { 1024-2048,2049-3333 } counter accept
			      ^^^^^^^^^^^^
			      this is causing problem.

both the strings "ip protocol" and "meta l4proto" is not introduced by libxt_multiport.
And in the absence of both , the command works.

For example , 
$ nft add rule ip filter INPUT tcp dport { 3-4 } tcp sport { 3-4 } counter accept

$ nft add rule ip6 filter input tcp dport { 1024-2048,2049-3333 } counter accept

Any comment regarding this behaviour ?
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Arturo Borrero March 9, 2016, 10:06 a.m. UTC | #3
On 9 March 2016 at 08:05, FaTe <gokuvsvegita@gmail.com> wrote:
> Hello Pablo,
>
> I would require some guidance regarding the libxt_multiport translation in nft.
>
> If the translation is over ip4 family :
> $ iptables-translate -A INPUT -p tcp -m multiport --ports 3:4  -j ACCEPT
> nft add rule ip filter INPUT ip protocol tcp dport { 3-4 } tcp sport { 3-4 } counter accept
>                              ^^^^^^^^^^^
>                              this causes problem.
> Similarly for ipv6 :
> $ ip6tables-translate -A input -p tcp -m multiport --dports 1024:2048,2049:3333 -j ACCEPT
> nft add rule ip6 filter input meta l4proto tcp dport { 1024-2048,2049-3333 } counter accept
>                               ^^^^^^^^^^^^
>                               this is causing problem.
>
> both the strings "ip protocol" and "meta l4proto" is not introduced by libxt_multiport.
> And in the absence of both , the command works.
>
> For example ,
> $ nft add rule ip filter INPUT tcp dport { 3-4 } tcp sport { 3-4 } counter accept
>
> $ nft add rule ip6 filter input tcp dport { 1024-2048,2049-3333 } counter accept
>
> Any comment regarding this behaviour ?

They are different statements, rules should be something like:
 * meta l4proto tcp tcp dport XX
 * ip protocol tcp tcp dport XX

However, the two statements are redundants... the second implies the first.
Piyush Pangtey March 9, 2016, 2:34 p.m. UTC | #4
On Wednesday 09 March 2016 03:36 PM, Arturo Borrero Gonzalez wrote:
> On 9 March 2016 at 08:05, FaTe <gokuvsvegita@gmail.com> wrote:
>> Hello Pablo,
>>
>> I would require some guidance regarding the libxt_multiport translation in nft.
>>
>> If the translation is over ip4 family :
>> $ iptables-translate -A INPUT -p tcp -m multiport --ports 3:4  -j ACCEPT
>> nft add rule ip filter INPUT ip protocol tcp dport { 3-4 } tcp sport { 3-4 } counter accept
>>                              ^^^^^^^^^^^
>>                              this causes problem.
>> Similarly for ipv6 :
>> $ ip6tables-translate -A input -p tcp -m multiport --dports 1024:2048,2049:3333 -j ACCEPT
>> nft add rule ip6 filter input meta l4proto tcp dport { 1024-2048,2049-3333 } counter accept
>>                               ^^^^^^^^^^^^
>>                               this is causing problem.
>>
>> both the strings "ip protocol" and "meta l4proto" is not introduced by libxt_multiport.
>> And in the absence of both , the command works.
>>
>> For example ,
>> $ nft add rule ip filter INPUT tcp dport { 3-4 } tcp sport { 3-4 } counter accept
>>
>> $ nft add rule ip6 filter input tcp dport { 1024-2048,2049-3333 } counter accept
>>
>> Any comment regarding this behaviour ?
> 
> They are different statements, rules should be something like:
>  * meta l4proto tcp tcp dport XX
>  * ip protocol tcp tcp dport XX
> 
> However, the two statements are redundants... the second implies the first.

Thanks Arturo !
It works.
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Patch
diff mbox

diff --git a/extensions/libipt_icmp.c b/extensions/libipt_icmp.c
index 666e7da..2c8be87 100644
--- a/extensions/libipt_icmp.c
+++ b/extensions/libipt_icmp.c
@@ -218,7 +218,7 @@  static void print_icmptype(uint8_t type,
 }
 
 static void icmp_print(const void *ip, const struct xt_entry_match *match,
-                       int numeric)
+		       int numeric)
 {
 	const struct ipt_icmp *icmp = (struct ipt_icmp *)match->data;
 
@@ -249,6 +249,52 @@  static void icmp_save(const void *ip, const struct xt_entry_match *match)
 	}
 }
 
+static unsigned int type_xlate_print(struct xt_xlate *xl, unsigned int icmptype,
+			     unsigned int code_min, unsigned int code_max)
+{
+	unsigned int i;
+
+	if (code_min == code_max)
+		return 0;
+
+	switch (icmptype) {
+	case 0xFF:
+	case 9:
+	case 10:
+		return 0;
+	default:
+		for (i = 0; i < ARRAY_SIZE(icmp_codes); ++i)
+			if (icmp_codes[i].type == icmptype &&
+			    icmp_codes[i].code_min == code_min &&
+			    icmp_codes[i].code_max == code_max)
+				break;
+
+		if (i != ARRAY_SIZE(icmp_codes))
+			xt_xlate_add(xl, icmp_codes[i].name);
+		else
+			return 0;
+	}
+
+	return 1;
+}
+
+static int icmp_xlate(const struct xt_entry_match *match, struct xt_xlate *xl,
+		       int numeric)
+{
+	const struct ipt_icmp *info = (struct ipt_icmp *)match->data;
+
+	xt_xlate_add(xl, "icmp type%s ",
+		     (info->invflags & IPT_ICMP_INV) ? " !=" : "");
+
+	if (!type_xlate_print(xl, info->type, info->code[0], info->code[1]))
+		return 0;
+
+	xt_xlate_add(xl, " ");
+
+	return 1;
+}
+
+
 static struct xtables_match icmp_mt_reg = {
 	.name		= "icmp",
 	.version	= XTABLES_VERSION,
@@ -261,6 +307,7 @@  static struct xtables_match icmp_mt_reg = {
 	.save		= icmp_save,
 	.x6_parse	= icmp_parse,
 	.x6_options	= icmp_opts,
+	.xlate		= icmp_xlate,
 };
 
 void _init(void)