nftutils: add and use wrappers for getprotoby{name,number}_r(), getservbyport_r()

We should aim to use the thread-safe variants of getprotoby{name,number}
and getservbyport(). However, they may not be available with other libc,
so it requires a configure check. As that is cumbersome, add wrappers
that do that at one place.

These wrappers are thread-safe, if libc provides the reentrant versions.
Use them.

Signed-off-by: Thomas Haller <thaller@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/src/json.c b/src/json.c
index 366c0edf..31dd1856 100644
--- a/src/json.c
+++ b/src/json.c
@@ -15,6 +15,7 @@
 #include <netlink.h>
 #include <rule.h>
 #include <rt.h>
+#include "nftutils.h"
 
 #include <netdb.h>
 #include <netinet/icmp6.h>
@@ -298,10 +299,10 @@ static json_t *chain_print_json(const struct chain *chain)
 
 static json_t *proto_name_json(uint8_t proto)
 {
-	const struct protoent *p = getprotobynumber(proto);
+	char name[NFT_PROTONAME_MAXSIZE];
 
-	if (p)
-		return json_string(p->p_name);
+	if (nft_getprotobynumber(proto, name, sizeof(name)))
+		return json_string(name);
 	return json_integer(proto);
 }
 
@@ -1094,12 +1095,11 @@ json_t *boolean_type_json(const struct expr *expr, struct output_ctx *octx)
 json_t *inet_protocol_type_json(const struct expr *expr,
 				struct output_ctx *octx)
 {
-	struct protoent *p;
-
 	if (!nft_output_numeric_proto(octx)) {
-		p = getprotobynumber(mpz_get_uint8(expr->value));
-		if (p != NULL)
-			return json_string(p->p_name);
+		char name[NFT_PROTONAME_MAXSIZE];
+
+		if (nft_getprotobynumber(mpz_get_uint8(expr->value), name, sizeof(name)))
+			return json_string(name);
 	}
 	return integer_type_json(expr, octx);
 }
@@ -1107,13 +1107,13 @@ json_t *inet_protocol_type_json(const struct expr *expr,
 json_t *inet_service_type_json(const struct expr *expr, struct output_ctx *octx)
 {
 	uint16_t port = mpz_get_be16(expr->value);
-	const struct servent *s = NULL;
+	char name[NFT_SERVNAME_MAXSIZE];
 
 	if (!nft_output_service(octx) ||
-	    (s = getservbyport(port, NULL)) == NULL)
+	    !nft_getservbyport(port, NULL, name, sizeof(name)))
 		return json_integer(ntohs(port));
 
-	return json_string(s->s_name);
+	return json_string(name);
 }
 
 json_t *mark_type_json(const struct expr *expr, struct output_ctx *octx)