src: consolidate XML/JSON exportation

Add new buffer class to consolidate the existing code to export objects
in XML/JSON and use it. We save ~700 LOC with this change.

The rule and set objects are not yet consolidated. It seems this would
require some specific glue code per representation type since lists are
arranged differently.

This also consolidates the tag names, so we make sure the same are used
from XML and JSON by placing them in include/buffer.h.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 23 insertions, 79 deletions

diff --git a/src/expr/nat.c b/src/expr/nat.c
index 60623a6..c9e05af 100644
--- a/src/expr/nat.c
+++ b/src/expr/nat.c
@@ -1,4 +1,5 @@
 /*
+ * (C) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org>
  * (C) 2012 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
@@ -23,6 +24,7 @@
 #include <libnftnl/expr.h>
 #include <libnftnl/rule.h>
 #include "expr_ops.h"
+#include <buffer.h>
 
 struct nft_expr_nat {
 	enum nft_registers sreg_addr_min;
@@ -196,7 +198,7 @@ nft_rule_expr_nat_build(struct nlmsghdr *nlh, struct nft_rule_expr *e)
 		mnl_attr_put_u32(nlh, NFTA_NAT_FLAGS, htonl(nat->flags));
 }
 
-static inline const char *nft_nat2str(uint16_t nat)
+static inline const char *nat2str(uint16_t nat)
 {
 	switch (nat) {
 	case NFT_NAT_SNAT:
@@ -329,85 +331,28 @@ static int nft_rule_expr_nat_xml_parse(struct nft_rule_expr *e, mxml_node_t *tre
 #endif
 }
 
-static int
-nft_rule_expr_nat_snprintf_json(char *buf, size_t size,
-				struct nft_rule_expr *e)
+static int nft_rule_expr_nat_export(char *buf, size_t size,
+				    struct nft_rule_expr *e, int type)
 {
 	struct nft_expr_nat *nat = nft_expr_data(e);
-	int len = size, offset = 0, ret = 0;
-
-	ret = snprintf(buf, len, "\"nat_type\":\"%s\",",
-		       nft_nat2str(nat->type));
-	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-
-	ret = snprintf(buf+offset, len, "\"family\":\"%s\",",
-		       nft_family2str(nat->family));
-	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-
-	if (e->flags & (1 << NFT_EXPR_NAT_REG_ADDR_MIN)) {
-		ret = snprintf(buf+offset, len, "\"sreg_addr_min\":%u,"
-						"\"sreg_addr_max\":%u,",
-			       nat->sreg_addr_min, nat->sreg_addr_max);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
-
-	if (e->flags & (1 << NFT_EXPR_NAT_REG_PROTO_MIN)) {
-		ret = snprintf(buf+offset, len, "\"sreg_proto_min\":%u,"
-						"\"sreg_proto_max\":%u,",
-		       nat->sreg_proto_min, nat->sreg_proto_max);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
-
-	if (e->flags & (1 << NFT_EXPR_NAT_FLAGS)) {
-		ret = snprintf(buf+offset, len, "\"flags\":%u,", nat->flags);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
-
-	/* Remove the last comma separator */
-	if (offset > 0)
-		offset--;
-
-	return offset;
-}
+	NFT_BUF_INIT(b, buf, size);
 
+	if (e->flags & (1 << NFT_EXPR_NAT_TYPE))
+		nft_buf_str(&b, type, nat2str(nat->type), NAT_TYPE);
+	if (e->flags & (1 << NFT_EXPR_NAT_FAMILY))
+		nft_buf_str(&b, type, nft_family2str(nat->family), FAMILY);
+	if (e->flags & (1 << NFT_EXPR_NAT_REG_ADDR_MIN))
+		nft_buf_u32(&b, type, nat->sreg_addr_min, SREG_ADDR_MIN);
+	if (e->flags & (1 << NFT_EXPR_NAT_REG_ADDR_MAX))
+		nft_buf_u32(&b, type, nat->sreg_addr_max, SREG_ADDR_MAX);
+	if (e->flags & (1 << NFT_EXPR_NAT_REG_PROTO_MIN))
+		nft_buf_u32(&b, type, nat->sreg_proto_min, SREG_PROTO_MIN);
+	if (e->flags & (1 << NFT_EXPR_NAT_REG_PROTO_MAX))
+		nft_buf_u32(&b, type, nat->sreg_proto_max, SREG_PROTO_MAX);
+	if (e->flags & (1 << NFT_EXPR_NAT_FLAGS))
+		nft_buf_u32(&b, type, nat->flags, FLAGS);
 
-static int
-nft_rule_expr_nat_snprintf_xml(char *buf, size_t size,
-				struct nft_rule_expr *e)
-{
-	struct nft_expr_nat *nat = nft_expr_data(e);
-	int len = size, offset = 0, ret = 0;
-
-	ret = snprintf(buf, len, "<type>%s</type>", nft_nat2str(nat->type));
-	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-
-	ret = snprintf(buf+offset, len, "<family>%s</family>",
-		       nft_family2str(nat->family));
-	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-
-	if (e->flags & (1 << NFT_EXPR_NAT_REG_ADDR_MIN)) {
-		ret = snprintf(buf+offset, len,
-				"<sreg_addr_min>%u</sreg_addr_min>"
-				"<sreg_addr_max>%u</sreg_addr_max>",
-			       nat->sreg_addr_min, nat->sreg_addr_max);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
-
-	if (e->flags & (1 << NFT_EXPR_NAT_REG_PROTO_MIN)) {
-		ret = snprintf(buf+offset, len,
-				"<sreg_proto_min>%u</sreg_proto_min>"
-				"<sreg_proto_max>%u</sreg_proto_max>",
-		       nat->sreg_proto_min, nat->sreg_proto_max);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
-
-	if (e->flags & (1 << NFT_EXPR_NAT_FLAGS)) {
-		ret = snprintf(buf+offset, len, "<flags>%u</flags>",
-			       nat->flags);
-		SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
-	}
-
-	return offset;
+	return nft_buf_done(&b);
 }
 
 static int
@@ -417,7 +362,7 @@ nft_rule_expr_nat_snprintf_default(char *buf, size_t size,
 	struct nft_expr_nat *nat = nft_expr_data(e);
 	int len = size, offset = 0, ret = 0;
 
-	ret = snprintf(buf, len, "%s ", nft_nat2str(nat->type));
+	ret = snprintf(buf, len, "%s ", nat2str(nat->type));
 	SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
 
 	ret = snprintf(buf+offset, len, "%s ", nft_family2str(nat->family));
@@ -453,9 +398,8 @@ nft_rule_expr_nat_snprintf(char *buf, size_t size, uint32_t type,
 	case NFT_OUTPUT_DEFAULT:
 		return nft_rule_expr_nat_snprintf_default(buf, size, e);
 	case NFT_OUTPUT_XML:
-		return nft_rule_expr_nat_snprintf_xml(buf, size, e);
 	case NFT_OUTPUT_JSON:
-		return nft_rule_expr_nat_snprintf_json(buf, size, e);
+		return nft_rule_expr_nat_export(buf, size, e, type);
 	default:
 		break;
 	}