conntrackd: add support to synchronize helper name

For both conntrack and expectations.

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

3 files changed, 55 insertions, 2 deletions

diff --git a/include/network.h b/include/network.h
index f3b1f8e..225ef0e 100644
--- a/include/network.h
+++ b/include/network.h
@@ -239,6 +239,7 @@ enum nta_attr {
 	NTA_ICMP_ID,		/* uint16_t */
 	NTA_TCP_WSCALE_ORIG,	/* uint8_t */
 	NTA_TCP_WSCALE_REPL,	/* uint8_t */
+	NTA_HELPER_NAME,	/* string (variable length) */
 	NTA_MAX
 };
 
@@ -274,6 +275,7 @@ enum nta_exp_attr {
 	NTA_EXP_NAT_PORT,		/* struct nfct_attr_grp_port */
 	NTA_EXP_NAT_L4PROTO,		/* uint8_t */
 	NTA_EXP_NAT_DIR,		/* uint32_t */
+	NTA_EXP_HELPER_NAME,		/* string (variable length) */
 	NTA_EXP_MAX
 };
 
diff --git a/src/build.c b/src/build.c
index c07f429..a2901b1 100644
--- a/src/build.c
+++ b/src/build.c
@@ -65,6 +65,13 @@ ct_build_u32(const struct nf_conntrack *ct, int a, struct nethdr *n, int b)
 	addattr(n, b, &data, sizeof(uint32_t));
 }
 
+static inline void
+ct_build_str(const struct nf_conntrack *ct, int a, struct nethdr *n, int b)
+{
+	const char *data = nfct_get_attr(ct, a);
+	addattr(n, b, data, strlen(data)+1);
+}
+
 static inline void 
 ct_build_group(const struct nf_conntrack *ct, int a, struct nethdr *n, 
 	      int b, int size)
@@ -223,6 +230,9 @@ void ct2msg(const struct nf_conntrack *ct, struct nethdr *n)
 	/* NAT sequence adjustment */
 	if (nfct_attr_is_set_array(ct, nat_type, 6))
 		ct_build_natseqadj(ct, n);
+
+	if (nfct_attr_is_set(ct, ATTR_HELPER_NAME))
+		ct_build_str(ct, ATTR_HELPER_NAME, n, NTA_HELPER_NAME);
 }
 
 static void
@@ -270,6 +280,13 @@ exp_build_u32(const struct nf_expect *exp, int a, struct nethdr *n, int b)
 	addattr(n, b, &data, sizeof(uint32_t));
 }
 
+static inline void
+exp_build_str(const struct nf_expect *exp, int a, struct nethdr *n, int b)
+{
+	const char *data = nfexp_get_attr(exp, a);
+	addattr(n, b, data, strlen(data)+1);
+}
+
 void exp2msg(const struct nf_expect *exp, struct nethdr *n)
 {
 	const struct nf_conntrack *ct = nfexp_get_attr(exp, ATTR_EXP_MASTER);
@@ -339,4 +356,5 @@ void exp2msg(const struct nf_expect *exp, struct nethdr *n)
 
 		exp_build_u32(exp, ATTR_EXP_NAT_DIR, n, NTA_EXP_NAT_DIR);
 	}
+	exp_build_str(exp, ATTR_EXP_HELPER_NAME, n, NTA_EXP_HELPER_NAME);
 }
diff --git a/src/parse.c b/src/parse.c
index 2430001..ceb9e26 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -28,6 +28,7 @@
 static void ct_parse_u8(struct nf_conntrack *ct, int attr, void *data);
 static void ct_parse_u16(struct nf_conntrack *ct, int attr, void *data);
 static void ct_parse_u32(struct nf_conntrack *ct, int attr, void *data);
+static void ct_parse_str(struct nf_conntrack *ct, int attr, void *data);
 static void ct_parse_group(struct nf_conntrack *ct, int attr, void *data);
 static void ct_parse_nat_seq_adj(struct nf_conntrack *ct, int attr, void *data);
 
@@ -35,6 +36,7 @@ struct ct_parser {
 	void 	(*parse)(struct nf_conntrack *ct, int attr, void *data);
 	int 	attr;
 	int	size;
+	int	max_size;
 };
 
 static struct ct_parser h[NTA_MAX] = {
@@ -172,6 +174,11 @@ static struct ct_parser h[NTA_MAX] = {
 		.attr	= ATTR_TCP_WSCALE_REPL,
 		.size	= NTA_SIZE(sizeof(uint8_t)),
 	},
+	[NTA_HELPER_NAME] = {
+		.parse	= ct_parse_str,
+		.attr	= ATTR_HELPER_NAME,
+		.max_size = NFCT_HELPER_NAME_MAX,
+	},
 };
 
 static void
@@ -196,6 +203,12 @@ ct_parse_u32(struct nf_conntrack *ct, int attr, void *data)
 }
 
 static void
+ct_parse_str(struct nf_conntrack *ct, int attr, void *data)
+{
+	nfct_set_attr(ct, h[attr].attr, data);
+}
+
+static void
 ct_parse_group(struct nf_conntrack *ct, int attr, void *data)
 {
 	nfct_set_attr_grp(ct, h[attr].attr, data);
@@ -236,7 +249,11 @@ int msg2ct(struct nf_conntrack *ct, struct nethdr *net, size_t remain)
 			return -1;
 		if (attr->nta_attr > NTA_MAX)
 			return -1;
-		if (attr->nta_len != h[attr->nta_attr].size)
+		if (h[attr->nta_attr].size &&
+		    attr->nta_len != h[attr->nta_attr].size)
+			return -1;
+		if (h[attr->nta_attr].max_size &&
+		    attr->nta_len > h[attr->nta_attr].max_size)
 			return -1;
 		if (h[attr->nta_attr].parse == NULL) {
 			attr = NTA_NEXT(attr, len);
@@ -252,12 +269,14 @@ int msg2ct(struct nf_conntrack *ct, struct nethdr *net, size_t remain)
 static void exp_parse_ct_group(void *ct, int attr, void *data);
 static void exp_parse_ct_u8(void *ct, int attr, void *data);
 static void exp_parse_u32(void *exp, int attr, void *data);
+static void exp_parse_str(void *exp, int attr, void *data);
 
 static struct exp_parser {
 	void 	(*parse)(void *obj, int attr, void *data);
 	int 	exp_attr;
 	int 	ct_attr;
 	int	size;
+	int	max_size;
 } exp_h[NTA_EXP_MAX] = {
 	[NTA_EXP_MASTER_IPV4] = {
 		.parse		= exp_parse_ct_group,
@@ -369,6 +388,11 @@ static struct exp_parser {
 		.exp_attr	= ATTR_EXP_NAT_DIR,
 		.size		= NTA_SIZE(sizeof(uint32_t)),
 	},
+	[NTA_EXP_HELPER_NAME] = {
+		.parse		= exp_parse_str,
+		.exp_attr	= ATTR_EXP_HELPER_NAME,
+		.max_size	= NFCT_HELPER_NAME_MAX,
+	},
 };
 
 static void exp_parse_ct_group(void *ct, int attr, void *data)
@@ -388,6 +412,11 @@ static void exp_parse_u32(void *exp, int attr, void *data)
 	nfexp_set_attr_u32(exp, exp_h[attr].exp_attr, ntohl(*value));
 }
 
+static void exp_parse_str(void *exp, int attr, void *data)
+{
+	nfexp_set_attr(exp, exp_h[attr].exp_attr, data);
+}
+
 int msg2exp(struct nf_expect *exp, struct nethdr *net, size_t remain)
 {
 	int len;
@@ -418,7 +447,11 @@ int msg2exp(struct nf_expect *exp, struct nethdr *net, size_t remain)
 			goto err;
 		if (attr->nta_attr > NTA_MAX)
 			goto err;
-		if (attr->nta_len != exp_h[attr->nta_attr].size)
+		if (exp_h[attr->nta_attr].size &&
+		    attr->nta_len != exp_h[attr->nta_attr].size)
+			goto err;
+		if (exp_h[attr->nta_attr].max_size &&
+		    attr->nta_len > exp_h[attr->nta_attr].max_size)
 			goto err;
 		if (exp_h[attr->nta_attr].parse == NULL) {
 			attr = NTA_NEXT(attr, len);