expr: basic support for printing nft_data_reg in XML format

nft_data_reg now is printed in XML according to what it contains

<data> nodes have been also renamed.

Arturo Borrero Gonzalez says:

====================
cmp is using <cmpdata> <cmpdata> has <data_reg></data_reg> which
can also be redundant.

But all around the XML printing (including sets, an incoming patch)
i've been nesting the data_reg into another XML node, so you could
easily see (also the XML parser) the difference between (for example.
in set) nft_set_elem->key and nft_set_elem->data.

As I needed to nest in nft_set_elem I decided to follow a constant
line and do nest all data_reg.
====================

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

5 files changed, 193 insertions, 43 deletions

diff --git a/src/expr/bitwise.c b/src/expr/bitwise.c
index ac89cba..052144e 100644
--- a/src/expr/bitwise.c
+++ b/src/expr/bitwise.c
@@ -199,29 +199,26 @@ static int
 nft_rule_expr_bitwise_snprintf_xml(char *buf, size_t size,
 				   struct nft_expr_bitwise *bitwise)
 {
-	int len = size, offset = 0, ret, i;
+	int len = size, offset = 0, ret;
 
 	ret = snprintf(buf, len, "\t\t<sreg>%u</sreg> "
 					"<dreg>%u</dreg> ",
-			bitwise->sreg, bitwise->dreg);
+		       bitwise->sreg, bitwise->dreg);
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	ret = snprintf(buf+offset, len, "<mask>");
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
-	for (i=0; i<bitwise->mask.len/sizeof(uint32_t); i++) {
-		ret = snprintf(buf+offset, len, "%.8x ",
-				bitwise->mask.val[i]);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
+	ret = nft_data_reg_snprintf(buf+offset, len, &bitwise->mask,
+				    NFT_RULE_O_XML, 0, DATA_VALUE);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	ret = snprintf(buf+offset, len, "</mask> <xor>");
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
-	for (i=0; i<bitwise->xor.len/sizeof(uint32_t); i++) {
-		ret = snprintf(buf+offset, len, "%.8x ", bitwise->xor.val[i]);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
+	ret = nft_data_reg_snprintf(buf+offset, len, &bitwise->xor,
+				    NFT_RULE_O_XML, 0, DATA_VALUE);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	ret = snprintf(buf+offset, len, "</xor> ");
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
@@ -231,29 +228,27 @@ nft_rule_expr_bitwise_snprintf_xml(char *buf, size_t size,
 
 static int
 nft_rule_expr_bitwise_snprintf_default(char *buf, size_t size,
-					struct nft_expr_bitwise *bitwise)
+				       struct nft_expr_bitwise *bitwise)
 {
-	int len = size, offset = 0, ret, i;
+	int len = size, offset = 0, ret;
 
 	ret = snprintf(buf, len, "sreg=%u dreg=%u ",
-			bitwise->sreg, bitwise->dreg);
+		       bitwise->sreg, bitwise->dreg);
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	ret = snprintf(buf+offset, len, " mask=");
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
-	for (i=0; i<bitwise->mask.len/sizeof(uint32_t); i++) {
-		ret = snprintf(buf+offset, len, "%.8x ", bitwise->mask.val[i]);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
+	ret = nft_data_reg_snprintf(buf+offset, len, &bitwise->mask,
+				    NFT_RULE_O_DEFAULT, 0, DATA_VALUE);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	ret = snprintf(buf+offset, len, " xor=");
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
-	for (i=0; i<bitwise->xor.len/sizeof(uint32_t); i++) {
-		ret = snprintf(buf+offset, len, "%.8x ", bitwise->xor.val[i]);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
+	ret = nft_data_reg_snprintf(buf+offset, len, &bitwise->xor,
+				    NFT_RULE_O_DEFAULT, 0, DATA_VALUE);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	return offset;
 }
diff --git a/src/expr/cmp.c b/src/expr/cmp.c
index 429f024..6b5a3a2 100644
--- a/src/expr/cmp.c
+++ b/src/expr/cmp.c
@@ -169,18 +169,17 @@ static char *expr_cmp_str[] = {
 static int
 nft_rule_expr_cmp_snprintf_xml(char *buf, size_t size, struct nft_expr_cmp *cmp)
 {
-	int len = size, offset = 0, ret, i;
+	int len = size, offset = 0, ret;
 
-	ret = snprintf(buf, len, "\t\t<sreg>%u</sreg> <op>%s</op> <data>",
-			cmp->sreg, expr_cmp_str[cmp->op]);
+	ret = snprintf(buf, len, "\t\t<sreg>%u</sreg> <op>%s</op> <cmpdata>",
+		       cmp->sreg, expr_cmp_str[cmp->op]);
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
-	for (i=0; i<cmp->data.len/sizeof(uint32_t); i++) {
-		ret = snprintf(buf+offset, len, "%.8x ", cmp->data.val[i]);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
+	ret = nft_data_reg_snprintf(buf+offset, len, &cmp->data,
+				    NFT_RULE_O_XML, 0, DATA_VALUE);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
-	ret = snprintf(buf+offset, len, "</data> ");
+	ret = snprintf(buf+offset, len, "</cmpdata> ");
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	return offset;
@@ -190,16 +189,16 @@ static int
 nft_rule_expr_cmp_snprintf_default(char *buf, size_t size,
 				   struct nft_expr_cmp *cmp)
 {
-	int len = size, offset = 0, ret, i;
+	int len = size, offset = 0, ret;
 
 	ret = snprintf(buf, len, "sreg=%u op=%s data=",
-			cmp->sreg, expr_cmp_str[cmp->op]);
+		       cmp->sreg, expr_cmp_str[cmp->op]);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	ret = nft_data_reg_snprintf(buf+offset, len, &cmp->data,
+				    NFT_RULE_O_DEFAULT, 0, DATA_VALUE);
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
-	for (i=0; i<cmp->data.len/sizeof(uint32_t); i++) {
-		ret = snprintf(buf+offset, len, "%.8x ", cmp->data.val[i]);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
 	return offset;
 }
 
diff --git a/src/expr/data_reg.c b/src/expr/data_reg.c
index 5b14695..78c7d49 100644
--- a/src/expr/data_reg.c
+++ b/src/expr/data_reg.c
@@ -18,10 +18,105 @@
 #include <linux/netfilter.h>
 #include <linux/netfilter/nf_tables.h>
 #include <libnftables/expr.h>
+#include <libnftables/rule.h>
 #include "expr_ops.h"
 #include "data_reg.h"
 #include "internal.h"
 
+static int nft_data_reg_value_snprintf_xml(char *buf, size_t size,
+					   union nft_data_reg *reg,
+					   uint32_t flags)
+{
+	int len = size, offset = 0, ret, i, j;
+	uint8_t *tmp;
+	int data_len = reg->len/sizeof(uint32_t);
+
+	ret = snprintf(buf, len, "<data_reg type=\"value\" >");
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	ret = snprintf(buf+offset, len, "<len>%d</len>", data_len);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	for (i=0; i<data_len; i++) {
+		ret = snprintf(buf+offset, len, "<data%d>0x", i);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+		tmp = (uint8_t *)&reg->val[i];
+
+		for (j=0; j<sizeof(int); j++) {
+			ret = snprintf(buf+offset, len, "%.02x", tmp[j]);
+			SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+		}
+
+		ret = snprintf(buf+offset, len, "</data%d>", i);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+
+	ret = snprintf(buf+offset, len, "</data_reg>");
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	return offset;
+}
+
+static int
+nft_data_reg_value_snprintf_default(char *buf, size_t size,
+				    union nft_data_reg *reg, uint32_t flags)
+{
+	int len = size, offset = 0, ret, i;
+
+	for (i=0; i<reg->len/sizeof(uint32_t); i++) {
+		ret = snprintf(buf+offset, len, "0x%.8x ", reg->val[i]);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+
+	return offset;
+}
+
+int nft_data_reg_snprintf(char *buf, size_t size, union nft_data_reg *reg,
+			  uint32_t output_format, uint32_t flags, int reg_type)
+{
+	switch(reg_type) {
+	case DATA_VALUE:
+		switch(output_format) {
+		case NFT_RULE_O_XML:
+			return nft_data_reg_value_snprintf_xml(buf, size,
+							       reg, flags);
+		case NFT_RULE_O_DEFAULT:
+			return nft_data_reg_value_snprintf_default(buf, size,
+								   reg, flags);
+		default:
+			break;
+		}
+	case DATA_VERDICT:
+		switch(output_format) {
+		case NFT_RULE_O_XML:
+			return snprintf(buf, size,
+					"<data_reg type=\"verdict\" >"
+						"<verdict>%d</verdict>"
+					"</data_reg>", reg->verdict);
+		case NFT_RULE_O_DEFAULT:
+			return snprintf(buf, size, "verdict=%d", reg->verdict);
+		default:
+			break;
+		}
+	case DATA_CHAIN:
+		switch(output_format) {
+		case NFT_RULE_O_XML:
+			return snprintf(buf, size,
+					"<data_reg type=\"chain\" >"
+						"<chain>%s</chain>"
+					"</data_reg>", reg->chain);
+		case NFT_RULE_O_DEFAULT:
+			return snprintf(buf, size, "chain=%s", reg->chain);
+		default:
+			break;
+		}
+	default:
+		break;
+	}
+	return -1;
+}
+
 static int nft_data_parse_cb(const struct nlattr *attr, void *data)
 {
 	const struct nlattr **tb = data;
diff --git a/src/expr/data_reg.h b/src/expr/data_reg.h
index 00eab63..1552c1e 100644
--- a/src/expr/data_reg.h
+++ b/src/expr/data_reg.h
@@ -18,6 +18,9 @@ union nft_data_reg {
 	};
 };
 
+int nft_data_reg_snprintf(char *buf, size_t size, union nft_data_reg *reg,
+                        uint32_t output_format, uint32_t flags, int reg_type);
+int nft_data_reg_xml_parse(union nft_data_reg *reg, char *xml);
 int nft_parse_data(union nft_data_reg *data, struct nlattr *attr, int *type);
 
 #endif
diff --git a/src/expr/immediate.c b/src/expr/immediate.c
index 496cbfd..082db76 100644
--- a/src/expr/immediate.c
+++ b/src/expr/immediate.c
@@ -196,19 +196,77 @@ nft_rule_expr_immediate_parse(struct nft_rule_expr *e, struct nlattr *attr)
 }
 
 static int
-nft_rule_expr_immediate_snprintf(char *buf, size_t len, uint32_t type,
-				 uint32_t flags, struct nft_rule_expr *e)
+nft_rule_expr_immediate_snprintf_xml(char *buf, size_t len,
+				     struct nft_rule_expr *e, uint32_t flags)
+{
+	int size = len, offset = 0, ret;
+	struct nft_expr_immediate *imm = (struct nft_expr_immediate *)e->data;
+
+	ret = snprintf(buf, len, "\t\t<dreg>%u</dreg>"
+				"\n\t\t<immediatedata>", imm->dreg);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+
+	if (e->flags & (1 << NFT_EXPR_IMM_DATA)) {
+		ret = nft_data_reg_snprintf(buf+offset, len, &imm->data,
+					    NFT_RULE_O_XML, flags, DATA_VALUE);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	} else if (e->flags & (1 << NFT_EXPR_IMM_VERDICT)) {
+		ret = nft_data_reg_snprintf(buf+offset, len, &imm->data,
+					  NFT_RULE_O_XML, flags, DATA_VERDICT);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	} else if (e->flags & (1 << NFT_EXPR_IMM_CHAIN)) {
+		ret = nft_data_reg_snprintf(buf+offset, len, &imm->data,
+					    NFT_RULE_O_XML, flags, DATA_CHAIN);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+
+	ret = snprintf(buf+offset, len, "</immediatedata>");
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	return offset;
+}
+
+static int
+nft_rule_expr_immediate_snprintf_default(char *buf, size_t len,
+				struct nft_rule_expr *e, uint32_t flags)
 {
+	int size = len, offset = 0, ret;
 	struct nft_expr_immediate *imm = (struct nft_expr_immediate *)e->data;
 
+	ret = snprintf(buf, len, "dreg=%u", imm->dreg);
+	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	if (e->flags & (1 << NFT_EXPR_IMM_DATA)) {
+		ret = nft_data_reg_snprintf(buf+offset, len, &imm->data,
+					NFT_RULE_O_DEFAULT, flags, DATA_VALUE);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	} else if (e->flags & (1 << NFT_EXPR_IMM_VERDICT)) {
+		ret = nft_data_reg_snprintf(buf+offset, len, &imm->data,
+				NFT_RULE_O_DEFAULT, flags, DATA_VERDICT);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+	} else if (e->flags & (1 << NFT_EXPR_IMM_CHAIN)) {
+		ret = nft_data_reg_snprintf(buf+offset, len, &imm->data,
+					NFT_RULE_O_DEFAULT, flags, DATA_CHAIN);
+		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+	}
+
+	return offset;
+}
+
+static int
+nft_rule_expr_immediate_snprintf(char *buf, size_t len, uint32_t type,
+				 uint32_t flags, struct nft_rule_expr *e)
+{
 	switch(type) {
 	case NFT_RULE_O_XML:
-		return snprintf(buf, len, "\t\t<dreg>%u</dreg>"
-					  " <data>%u</data> ",
-				imm->dreg, imm->data.val[0]);
+		return nft_rule_expr_immediate_snprintf_xml(buf, len, e, flags);
 	case NFT_RULE_O_DEFAULT:
-		return snprintf(buf, len, "dreg=%u data=%u ",
-				imm->dreg, imm->data.val[0]);
+		return nft_rule_expr_immediate_snprintf_default(buf, len, e, flags);
 	default:
 		break;
 	}