[libnftnl PATCH v4 0/3] Do not print unset value in xml file

[libnftnl PATCH v4 0/3] Do not print unset value in xml file

[Ana Rey]

Hi,

In this version, I add a new patch:
"expr: log: Rename variables in nft_rule_expr_log_json_parse functions"

It removes these changes out of "Use nft_rule_expr_set_* in the xml parsing code"
patch.

Also, I fix some errors with nft_rule_expr_set_* functions in
"Use nft_rule_expr_set_* in the xml parsing code" patch.

[Change in v3:]
In this version, I rename some variables, I fix writing errors in the patch
description and I fix wrong indentation.

[Change in v2:]

Hi,
After some advises of Arturo Borrero, I send a previous patch to
'Code refactoring to use nft_rule_expr_set_* functions' patch and v2 of
"Do not print unset values in xml" patch.


Ana Rey (3):
  expr: log: Rename variables in nft_rule_expr_log_json_parse functions
  expr: log: Use nft_rule_expr_set_* in the xml parsing code
  expr: log: Do not print unset values in xml

 src/expr/log.c | 95 +++++++++++++++++++++++++++++++++-------------------------
 1 file changed, 54 insertions(+), 41 deletions(-)

-- 
2.0.0.rc2

[libnftnl PATCH v4 1/3] expr: log: Rename variables in nft_rule_expr_log_json_parse functions

[Ana Rey]

Renames some variables for code readability reasons.

Signed-off-by: Ana Rey <anarey@gmail.com>
---
 src/expr/log.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/expr/log.c b/src/expr/log.c
index a61a8d3..eaba1d6 100644
--- a/src/expr/log.c
+++ b/src/expr/log.c
@@ -166,7 +166,8 @@ static int nft_rule_expr_log_json_parse(struct nft_rule_expr *e, json_t *root,
 #ifdef JSON_PARSING
 	const char *prefix;
 	uint32_t snaplen;
-	uint16_t uval16;
+	uint16_t group;
+	uint16_t qthreshold;
 
 	prefix = nft_jansson_parse_str(root, "prefix", err);
 	if (prefix == NULL)
@@ -174,11 +175,11 @@ static int nft_rule_expr_log_json_parse(struct nft_rule_expr *e, json_t *root,
 
 	nft_rule_expr_set_str(e, NFT_EXPR_LOG_PREFIX, prefix);
 
-	if (nft_jansson_parse_val(root, "group", NFT_TYPE_U16, &uval16,
+	if (nft_jansson_parse_val(root, "group", NFT_TYPE_U16, &group,
 				  err) < 0)
 		return -1;
 
-	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_GROUP, uval16);
+	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_GROUP, group);
 
 	if (nft_jansson_parse_val(root, "snaplen", NFT_TYPE_U32, &snaplen,
 				  err) < 0)
@@ -187,10 +188,10 @@ static int nft_rule_expr_log_json_parse(struct nft_rule_expr *e, json_t *root,
 	nft_rule_expr_set_u32(e, NFT_EXPR_LOG_SNAPLEN, snaplen);
 
 	if (nft_jansson_parse_val(root, "qthreshold", NFT_TYPE_U16,
-				  &uval16, err) < 0)
+				  &qthreshold, err) < 0)
 		return -1;
 
-	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_QTHRESHOLD, uval16);
+	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_QTHRESHOLD, qthreshold);
 
 	return 0;
 #else
-- 
2.0.0.rc2

[libnftnl PATCH v4 2/3] expr: log: Use nft_rule_expr_set_* in the xml parsing code

[Ana Rey]

Code refactoring to use nft_rule_expr_set_* in parse functions.

Signed-off-by: Ana Rey <anarey@gmail.com>
Suggested-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
---
 src/expr/log.c | 49 ++++++++++++++++++++++++-------------------------
 1 file changed, 24 insertions(+), 25 deletions(-)

diff --git a/src/expr/log.c b/src/expr/log.c
index eaba1d6..392bb14 100644
--- a/src/expr/log.c
+++ b/src/expr/log.c
@@ -133,6 +133,10 @@ nft_rule_expr_log_parse(struct nft_rule_expr *e, struct nlattr *attr)
 {
 	struct nft_expr_log *log = nft_expr_data(e);
 	struct nlattr *tb[NFTA_LOG_MAX+1] = {};
+	const char *prefix;
+	uint32_t snaplen;
+	uint16_t group;
+	uint16_t qthreshold;
 
 	if (mnl_attr_parse_nested(attr, nft_rule_expr_log_cb, tb) < 0)
 		return -1;
@@ -141,20 +145,20 @@ nft_rule_expr_log_parse(struct nft_rule_expr *e, struct nlattr *attr)
 		if (log->prefix)
 			xfree(log->prefix);
 
-		log->prefix = strdup(mnl_attr_get_str(tb[NFTA_LOG_PREFIX]));
-		e->flags |= (1 << NFT_EXPR_LOG_PREFIX);
+		prefix = strdup(mnl_attr_get_str(tb[NFTA_LOG_PREFIX]));
+		nft_rule_expr_set_str(e, NFT_EXPR_LOG_PREFIX, prefix);
 	}
 	if (tb[NFTA_LOG_GROUP]) {
-		log->group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP]));
-		e->flags |= (1 << NFT_EXPR_LOG_GROUP);
+		group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP]));
+		nft_rule_expr_set_u16(e, NFT_EXPR_LOG_GROUP, group);
 	}
 	if (tb[NFTA_LOG_SNAPLEN]) {
-		log->snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN]));
-		e->flags |= (1 << NFT_EXPR_LOG_SNAPLEN);
+		snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN]));
+		nft_rule_expr_set_u32(e, NFT_EXPR_LOG_SNAPLEN, snaplen);
 	}
 	if (tb[NFTA_LOG_QTHRESHOLD]) {
-		log->qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD]));
-		e->flags |= (1 << NFT_EXPR_LOG_QTHRESHOLD);
+		qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD]));
+		nft_rule_expr_set_u16(e, NFT_EXPR_LOG_QTHRESHOLD, qthreshold);
 	}
 
 	return 0;
@@ -205,37 +209,32 @@ static int nft_rule_expr_log_xml_parse(struct nft_rule_expr *e,
 				       struct nft_parse_err *err)
 {
 #ifdef XML_PARSING
-	struct nft_expr_log *log = nft_expr_data(e);
 	const char *prefix;
+	uint32_t snaplen;
+	uint16_t group;
+	uint16_t qthreshold;
 
 	prefix = nft_mxml_str_parse(tree, "prefix", MXML_DESCEND_FIRST,
 				    NFT_XML_MAND, err);
 	if (prefix == NULL)
 		return -1;
-
-	log->prefix = strdup(prefix);
-	e->flags |= (1 << NFT_EXPR_LOG_PREFIX);
+	nft_rule_expr_set_str(e, NFT_EXPR_LOG_PREFIX, prefix);
 
 	if (nft_mxml_num_parse(tree, "group", MXML_DESCEND_FIRST, BASE_DEC,
-			       &log->group, NFT_TYPE_U16, NFT_XML_MAND,
-			       err) != 0)
+			       &group, NFT_TYPE_U16, NFT_XML_MAND, err) < 0)
 		return -1;
-
-	e->flags |= (1 << NFT_EXPR_LOG_GROUP);
+	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_GROUP, group);
 
 	if (nft_mxml_num_parse(tree, "snaplen", MXML_DESCEND_FIRST, BASE_DEC,
-			       &log->snaplen, NFT_TYPE_U32, NFT_XML_MAND,
-			       err) != 0)
+			       &snaplen, NFT_TYPE_U32, NFT_XML_MAND, err) < 0)
 		return -1;
+	nft_rule_expr_set_u32(e, NFT_EXPR_LOG_SNAPLEN, snaplen);
 
-	e->flags |= (1 << NFT_EXPR_LOG_SNAPLEN);
-
-	if (nft_mxml_num_parse(tree, "qthreshold", MXML_DESCEND_FIRST,
-			       BASE_DEC, &log->qthreshold,
-			       NFT_TYPE_U16, NFT_XML_MAND, err) != 0)
+	if (nft_mxml_num_parse(tree, "qthreshold", MXML_DESCEND_FIRST, BASE_DEC,
+			       &qthreshold, NFT_TYPE_U16, NFT_XML_MAND,
+			       err) < 0)
 		return -1;
-
-	e->flags |= (1 << NFT_EXPR_LOG_QTHRESHOLD);
+	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_QTHRESHOLD, qthreshold);
 
 	return 0;
 #else
-- 
2.0.0.rc2

[libnftnl PATCH v4 3/3] expr: log: Do not print unset values in xml

[Ana Rey]

It changes the parse and the snprint functions to omit unset values.

If we used this rule:
nft add rule ip test output log

We got this xml file:
<rule><family>ip</family>
<table>test</table>
<chain>output</chain>
<handle>88</handle>
<expr type="log">
        <prefix>(null)</prefix>
        <group>0</group>
        <snaplen>0</snaplen>
        <qthreshold>0</qthreshold>
</expr>
</rule>

And It was imposible import this file.

Now, That rule creates this xml file without null values:

<rule><family>ip</family>
<table>test</table>
<chain>output</chain>
<handle>88</handle>
<expr type="log">
</expr>
</rule>

and It's possible import this xml file.

Signed-off-by: Ana Rey <anarey@gmail.com>
---
 src/expr/log.c | 49 +++++++++++++++++++++++++++++++------------------
 1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/src/expr/log.c b/src/expr/log.c
index 392bb14..fda353b 100644
--- a/src/expr/log.c
+++ b/src/expr/log.c
@@ -216,25 +216,21 @@ static int nft_rule_expr_log_xml_parse(struct nft_rule_expr *e,
 
 	prefix = nft_mxml_str_parse(tree, "prefix", MXML_DESCEND_FIRST,
 				    NFT_XML_MAND, err);
-	if (prefix == NULL)
-		return -1;
-	nft_rule_expr_set_str(e, NFT_EXPR_LOG_PREFIX, prefix);
+	if (prefix != NULL)
+		nft_rule_expr_set_str(e, NFT_EXPR_LOG_PREFIX, prefix);
 
 	if (nft_mxml_num_parse(tree, "group", MXML_DESCEND_FIRST, BASE_DEC,
-			       &group, NFT_TYPE_U16, NFT_XML_MAND, err) < 0)
-		return -1;
-	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_GROUP, group);
+			       &group, NFT_TYPE_U16, NFT_XML_MAND, err) == 0)
+		nft_rule_expr_set_u16(e, NFT_EXPR_LOG_GROUP, group);
 
 	if (nft_mxml_num_parse(tree, "snaplen", MXML_DESCEND_FIRST, BASE_DEC,
-			       &snaplen, NFT_TYPE_U32, NFT_XML_MAND, err) < 0)
-		return -1;
-	nft_rule_expr_set_u32(e, NFT_EXPR_LOG_SNAPLEN, snaplen);
+			       &snaplen, NFT_TYPE_U32, NFT_XML_MAND, err) == 0)
+		nft_rule_expr_set_u32(e, NFT_EXPR_LOG_SNAPLEN, snaplen);
 
 	if (nft_mxml_num_parse(tree, "qthreshold", MXML_DESCEND_FIRST, BASE_DEC,
 			       &qthreshold, NFT_TYPE_U16, NFT_XML_MAND,
-			       err) < 0)
-		return -1;
-	nft_rule_expr_set_u16(e, NFT_EXPR_LOG_QTHRESHOLD, qthreshold);
+			       err) == 0)
+		nft_rule_expr_set_u16(e, NFT_EXPR_LOG_QTHRESHOLD, qthreshold);
 
 	return 0;
 #else
@@ -256,14 +252,31 @@ static int nft_rule_expr_log_snprintf_default(char *buf, size_t len,
 static int nft_rule_expr_log_snprintf_xml(char *buf, size_t size,
 					  struct nft_rule_expr *e)
 {
+	int ret, len = size, offset = 0;
 	struct nft_expr_log *log = nft_expr_data(e);
 
-	return snprintf(buf, size, "<prefix>%s</prefix>"
-				   "<group>%u</group>"
-				   "<snaplen>%u</snaplen>"
-				   "<qthreshold>%u</qthreshold>",
-			log->prefix, log->group,
-			log->snaplen, log->qthreshold);
+	if (e->flags & (1 << NFT_EXPR_LOG_PREFIX)) {
+		ret = snprintf(buf+offset, len, "<prefix>%s</prefix>",
+			       log->prefix);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+	if (e->flags & (1 << NFT_EXPR_LOG_GROUP)) {
+		ret = snprintf(buf+offset, len, "<group>%u</group>",
+			       log->group);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+	if (e->flags & (1 << NFT_EXPR_LOG_SNAPLEN)) {
+		ret = snprintf(buf+offset, len, "<snaplen>%u</snaplen>",
+			       log->snaplen);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+	if (e->flags & (1 << NFT_EXPR_LOG_QTHRESHOLD)) {
+		ret = snprintf(buf+offset, len, "<qthreshold>%u</qthreshold>",
+			       log->qthreshold);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+
+	return offset;
 }
 
 static int nft_rule_expr_log_snprintf_json(char *buf, size_t len,
-- 
2.0.0.rc2

Re: [libnftnl PATCH v4 1/3] expr: log: Rename variables in nft_rule_expr_log_json_parse functions

[Pablo Neira Ayuso]

On Tue, Jun 03, 2014 at 12:41:54PM +0200, Ana Rey wrote:
> Renames some variables for code readability reasons.
> 
> Signed-off-by: Ana Rey <anarey@gmail.com>
> ---
>  src/expr/log.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/src/expr/log.c b/src/expr/log.c
> index a61a8d3..eaba1d6 100644
> --- a/src/expr/log.c
> +++ b/src/expr/log.c
> @@ -166,7 +166,8 @@ static int nft_rule_expr_log_json_parse(struct nft_rule_expr *e, json_t *root,
>  #ifdef JSON_PARSING
>  	const char *prefix;
>  	uint32_t snaplen;
> -	uint16_t uval16;
> +	uint16_t group;
> +	uint16_t qthreshold;

Applied, but I have merge the two variable definitions above.

Re: [libnftnl PATCH v4 2/3] expr: log: Use nft_rule_expr_set_* in the xml parsing code

[Pablo Neira Ayuso]

On Tue, Jun 03, 2014 at 12:41:55PM +0200, Ana Rey wrote:
> Code refactoring to use nft_rule_expr_set_* in parse functions.

Applied, but removed the netlink chunk, it should come in a separated
patch.

Re: [libnftnl PATCH v4 3/3] expr: log: Do not print unset values in xml

[Pablo Neira Ayuso]

On Tue, Jun 03, 2014 at 12:41:56PM +0200, Ana Rey wrote:
> It changes the parse and the snprint functions to omit unset values.
> 
> If we used this rule:
> nft add rule ip test output log
> 
> We got this xml file:
> <rule><family>ip</family>
> <table>test</table>
> <chain>output</chain>
> <handle>88</handle>
> <expr type="log">
>         <prefix>(null)</prefix>
>         <group>0</group>
>         <snaplen>0</snaplen>
>         <qthreshold>0</qthreshold>
> </expr>
> </rule>
> 
> And It was imposible import this file.
> 
> Now, That rule creates this xml file without null values:
> 
> <rule><family>ip</family>
> <table>test</table>
> <chain>output</chain>
> <handle>88</handle>
> <expr type="log">
> </expr>
> </rule>
> 
> and It's possible import this xml file.

Applied, thanks Ana.