trafgen: proto: Reference to packet from struct proto_hdr

Using of current_packet() is not possible for dynamically updated fields
so we need to keep the packet index in proto_hdr struct to reference the
correct packet.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

4 files changed, 23 insertions, 6 deletions

diff --git a/trafgen_conf.h b/trafgen_conf.h
index 50b437b..efce29c 100644
--- a/trafgen_conf.h
+++ b/trafgen_conf.h
@@ -63,5 +63,7 @@ extern void cleanup_packets(void);
 extern void set_fill(uint8_t val, size_t len);
 
 extern struct packet *current_packet(void);
+extern uint32_t current_packet_id(void);
+extern struct packet *packet_get(uint32_t id);
 
 #endif /* TRAFGEN_CONF */
diff --git a/trafgen_parser.y b/trafgen_parser.y
index 0fe8674..a286e6b 100644
--- a/trafgen_parser.y
+++ b/trafgen_parser.y
@@ -153,6 +153,16 @@ struct packet *current_packet(void)
 	return &packets[packet_last];
 }
 
+uint32_t current_packet_id(void)
+{
+	return packet_last;
+}
+
+struct packet *packet_get(uint32_t id)
+{
+	return &packets[id];
+}
+
 static void set_byte(uint8_t val)
 {
 	struct packet *pkt = &packets[packet_last];
diff --git a/trafgen_proto.c b/trafgen_proto.c
index cb0c6ae..e5b1ad3 100644
--- a/trafgen_proto.c
+++ b/trafgen_proto.c
@@ -49,7 +49,7 @@ struct proto_hdr *proto_lower_header(struct proto_hdr *hdr)
 
 uint8_t *proto_header_ptr(struct proto_hdr *hdr)
 {
-	return &current_packet()->payload[hdr->pkt_offset];
+	return &packet_get(hdr->pkt_id)->payload[hdr->pkt_offset];
 }
 
 static struct proto_hdr *proto_header_by_id(enum proto_id id)
@@ -81,7 +81,7 @@ static void proto_fields_realloc(struct proto_hdr *hdr, size_t count)
 void proto_header_fields_add(struct proto_hdr *hdr,
 			     const struct proto_field *fields, size_t count)
 {
-	struct packet *pkt = current_packet();
+	struct packet *pkt = packet_get(hdr->pkt_id);
 	struct proto_field *f;
 	int i;
 
@@ -99,6 +99,7 @@ void proto_header_fields_add(struct proto_hdr *hdr,
 		f->shift = fields[i].shift;
 		f->mask = fields[i].mask;
 		f->pkt_offset = hdr->pkt_offset + fields[i].offset;
+		f->hdr = hdr;
 
 		if (f->pkt_offset + f->len > pkt->len) {
 			hdr->len += f->len;
@@ -135,6 +136,8 @@ struct proto_hdr *proto_header_init(enum proto_id pid)
 	new_hdr = xmalloc(sizeof(*new_hdr));
 	memcpy(new_hdr, hdr, sizeof(*new_hdr));
 
+	new_hdr->pkt_id = current_packet_id();
+
 	if (new_hdr->header_init)
 		new_hdr->header_init(new_hdr);
 
@@ -187,7 +190,7 @@ static void __proto_field_set_bytes(struct proto_hdr *hdr, uint32_t fid,
 	if (is_default && field->is_set)
 		return;
 
-	payload = &current_packet()->payload[field->pkt_offset];
+	payload = &packet_get(hdr->pkt_id)->payload[field->pkt_offset];
 
 	if (field->len == 1) {
 		p8 = payload;
@@ -232,9 +235,7 @@ void proto_field_set_bytes(struct proto_hdr *hdr, uint32_t fid, uint8_t *bytes)
 
 static uint8_t *__proto_field_get_bytes(struct proto_field *field)
 {
-	struct packet *pkt = current_packet();
-
-	return &pkt->payload[field->pkt_offset];
+	return &packet_get(field->hdr->pkt_id)->payload[field->pkt_offset];
 }
 
 void proto_field_set_u8(struct proto_hdr *hdr, uint32_t fid, uint8_t val)
diff --git a/trafgen_proto.h b/trafgen_proto.h
index 72cd9f7..d2fde62 100644
--- a/trafgen_proto.h
+++ b/trafgen_proto.h
@@ -30,6 +30,8 @@ enum proto_layer {
 	PROTO_L4,
 };
 
+struct proto_hdr;
+
 struct proto_field {
 	uint32_t id;
 	size_t len;
@@ -40,6 +42,7 @@ struct proto_field {
 
 	bool is_set;
 	uint16_t pkt_offset;
+	struct proto_hdr *hdr;
 };
 
 struct proto_hdr {
@@ -49,6 +52,7 @@ struct proto_hdr {
 	struct proto_hdr *next;
 	struct proto_ctx *ctx;
 	uint16_t pkt_offset;
+	uint32_t pkt_id;
 	struct proto_field *fields;
 	size_t fields_count;
 	size_t len;