From 9d5e303a998e4618d492c9d0befb09e3cd3d746b Mon Sep 17 00:00:00 2001 From: Vadim Kochan Date: Thu, 1 Jun 2017 13:12:28 +0300 Subject: trafgen: l7: Add DNS header generation API Add trafgen_l7.c module with DNS proto header generation with support of filling DNS query/answer/authority/additional sections as sub headers. Introcuded new concept as 'sub header' which is needed to easy handle DNS sections which might be added on-demand, and to simplify using sub-header as regular header with a fields, offset, etc. There is a parent header which contains array of pointers of sub-headers, and the array is ordered as they are located in the parent header. The sub-headers mostly encapsulated by the parent header which 'knows' the semantic of them. The new proto_hdr->push_sub_header(...) callback was added to tell the parent header to push the sub-header's fields, sub-header also may have proto_ops which must be filled by the parent. This sub-header concept might be used in the future if it will be needed to support DHCP, WLAN headers. There are 4 kinds of DNS sub-headers - query, answer, authority, additional. 'id' of each sub-header is used to only differentiate these types of sections. These sections have strict order inside DNS header, and there was added the proto_hdr_move_sub_header(...) to sort them in required order. Actually there are only 2 proto_hdr's which describes 4 DNS sections - query & rrecord, because rrecord covers another 3 - answer, auhority, additional which have the same layout. Signed-off-by: Vadim Kochan Signed-off-by: Tobias Klauser --- trafgen_proto.h | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'trafgen_proto.h') diff --git a/trafgen_proto.h b/trafgen_proto.h index 94eb4e7..f3d07ba 100644 --- a/trafgen_proto.h +++ b/trafgen_proto.h @@ -19,6 +19,7 @@ enum proto_id { PROTO_ICMP6, PROTO_UDP, PROTO_TCP, + PROTO_DNS, __PROTO_MAX, }; @@ -27,6 +28,7 @@ enum proto_layer { PROTO_L2, PROTO_L3, PROTO_L4, + PROTO_L7, }; struct proto_field; @@ -38,6 +40,7 @@ struct proto_ops { void (*header_init)(struct proto_hdr *hdr); void (*header_finish)(struct proto_hdr *hdr); + void (*push_sub_header)(struct proto_hdr *hdr, struct proto_hdr *sub_hdr); void (*field_changed)(struct proto_field *field); void (*packet_finish)(struct proto_hdr *hdr); void (*packet_update)(struct proto_hdr *hdr); @@ -46,12 +49,16 @@ struct proto_ops { struct proto_hdr { const struct proto_ops *ops; + struct proto_hdr *parent; + struct proto_hdr **sub_headers; + uint32_t sub_headers_count; uint16_t pkt_offset; uint32_t pkt_id; uint32_t index; struct proto_field *fields; size_t fields_count; bool is_csum_valid; + uint32_t id; size_t len; }; @@ -95,6 +102,10 @@ extern void proto_header_finish(struct proto_hdr *hdr); extern void proto_packet_finish(void); extern void proto_packet_update(uint32_t idx); +extern struct proto_hdr *proto_hdr_push_sub_header(struct proto_hdr *hdr, int id); +extern void proto_hdr_move_sub_header(struct proto_hdr *hdr, struct proto_hdr *from, + struct proto_hdr *to); + extern struct proto_hdr *proto_lower_default_add(struct proto_hdr *hdr, enum proto_id pid); @@ -142,6 +153,9 @@ extern void proto_hdr_field_set_default_dev_ipv4(struct proto_hdr *hdr, uint32_t extern void proto_hdr_field_set_dev_ipv6(struct proto_hdr *hdr, uint32_t fid); extern void proto_hdr_field_set_default_dev_ipv6(struct proto_hdr *hdr, uint32_t fid); +extern void proto_hdr_field_set_string(struct proto_hdr *hdr, uint32_t fid, const char *str); +extern void proto_hdr_field_set_default_string(struct proto_hdr *hdr, uint32_t fid, const char *str); + extern void proto_field_dyn_apply(struct proto_field *field); extern struct proto_field *proto_hdr_field_by_id(struct proto_hdr *hdr, uint32_t fid); @@ -155,8 +169,9 @@ extern void proto_field_set_u32(struct proto_field *field, uint32_t val); extern uint32_t proto_field_get_u32(struct proto_field *field); extern void proto_field_set_be16(struct proto_field *field, uint16_t val); extern void proto_field_set_be32(struct proto_field *field, uint32_t val); -extern void proto_field_set_bytes(struct proto_field *field, const uint8_t *bytes, - size_t len); +extern void proto_field_set_bytes(struct proto_field *field, const uint8_t *bytes, size_t len); +extern void proto_field_set_string(struct proto_field *field, const char *str); +extern void proto_field_set_default_string(struct proto_field *field, const char *str); extern void proto_field_func_add(struct proto_field *field, struct proto_field_func *func); -- cgit v1.2.3-54-g00ecf