trafgen: proto: Add ICMPv6 header generation

Support for generating simple ICMPv6 headers using the 'icmp6()/icmpv6()'
trafgen generation function.

Fields supported:

  mtype  Message type (default: 0)
         Supported keywords: echorequest, echoreply
  code   Code (default: 0)
  csum   Message checksum (calculated by default)

Examples:

  { eth(), ipv6(daddr=::1), icmpv6(echorequest), 42, 42, 0, 0  }'

If not explicitely specified, the lower header is initialized as Ethernet.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

7 files changed, 125 insertions, 0 deletions

diff --git a/trafgen.8 b/trafgen.8
index c81fecb..3075daa 100644
--- a/trafgen.8
+++ b/trafgen.8
@@ -498,6 +498,31 @@ By default, if the lower level header is Ethernet, its EtherType field is set to
 By default, if the lower level header is Ethernet, its EtherType field is set to
 0x86DD (IPv6).
 
+.I ICMPv6
+:
+.B icmp6|icmpv6(mtype=<number>, echorequest, echoreply, code=<number>,
+.B csum=<number>)
+.sp
+.in +4
+.B mtype
+- Message type (default: 0)
+.sp
+.B code
+- Code (default: 0)
+.sp
+.B echorequest
+- ICMPv6 echo (ping) request
+.sp
+.B echoreply
+- ICMPv6 echo (ping) reply
+.sp
+.B csum
+- Message checksum (calculated by default)
+.in -4
+.sp
+By default, if the lower level header is IPv6, its Next Header field is set to
+58 (ICMPv6).
+
 .I UDP
 :
 .B udp(sp=<number>, dp=<number>, len=<number>, csum=<number>)
diff --git a/trafgen_l3.c b/trafgen_l3.c
index 94c0755..cbdbe6c 100644
--- a/trafgen_l3.c
+++ b/trafgen_l3.c
@@ -126,6 +126,9 @@ static void ipv6_set_next_proto(struct proto_hdr *hdr, enum proto_id pid)
 	uint8_t ip_proto;
 
 	switch(pid) {
+	case PROTO_ICMP6:
+		ip_proto = IPPROTO_ICMPV6;
+		break;
 	case PROTO_UDP:
 		ip_proto = IPPROTO_UDP;
 		break;
diff --git a/trafgen_l4.c b/trafgen_l4.c
index a5981c4..886e2b2 100644
--- a/trafgen_l4.c
+++ b/trafgen_l4.c
@@ -138,8 +138,57 @@ static struct proto_hdr tcp_hdr = {
 	.packet_finish  = tcp_packet_finish,
 };
 
+static struct proto_field icmpv6_fields[] = {
+	{ .id = ICMPV6_TYPE, .len = 1, .offset = 0 },
+	{ .id = ICMPV6_CODE, .len = 1, .offset = 1 },
+	{ .id = ICMPV6_CSUM, .len = 2, .offset = 2 }
+};
+
+static void icmpv6_header_init(struct proto_hdr *hdr)
+{
+	proto_lower_default_add(hdr, PROTO_IP6);
+
+	proto_header_fields_add(hdr, icmpv6_fields, array_size(icmpv6_fields));
+}
+
+static void icmpv6_packet_finish(struct proto_hdr *hdr)
+{
+	struct proto_hdr *lower = proto_lower_header(hdr);
+	struct packet *pkt = current_packet();
+	uint16_t total_len;
+	uint16_t csum;
+
+	if (proto_field_is_set(hdr, ICMPV6_CSUM))
+		return;
+
+	if (!lower)
+		return;
+
+	total_len = pkt->len - hdr->pkt_offset;
+
+	switch (lower->id) {
+	case PROTO_IP6:
+		csum = p6_csum((void *) proto_header_ptr(lower), proto_header_ptr(hdr),
+				total_len, IPPROTO_ICMPV6);
+		break;
+	default:
+		csum = 0;
+		break;
+	}
+
+	proto_field_set_be16(hdr, ICMPV6_CSUM, bswap_16(csum));
+}
+
+static struct proto_hdr icmpv6_hdr = {
+	.id		= PROTO_ICMP6,
+	.layer		= PROTO_L4,
+	.header_init	= icmpv6_header_init,
+	.packet_finish  = icmpv6_packet_finish,
+};
+
 void protos_l4_init(void)
 {
 	proto_header_register(&udp_hdr);
 	proto_header_register(&tcp_hdr);
+	proto_header_register(&icmpv6_hdr);
 }
diff --git a/trafgen_l4.h b/trafgen_l4.h
index da73ebc..e94ff23 100644
--- a/trafgen_l4.h
+++ b/trafgen_l4.h
@@ -27,6 +27,12 @@ enum tcp_field {
 	TCP_URG_PTR,
 };
 
+enum icmpv6_field {
+	ICMPV6_TYPE,
+	ICMPV6_CODE,
+	ICMPV6_CSUM,
+};
+
 extern void protos_l4_init(void);
 
 #endif /* TRAFGEN_L4_H */
diff --git a/trafgen_lexer.l b/trafgen_lexer.l
index a093ac1..eb438a8 100644
--- a/trafgen_lexer.l
+++ b/trafgen_lexer.l
@@ -161,6 +161,12 @@ ip6_addr	(({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:
 "nh"|"nexthdr"	{ return K_NEXT_HDR; }
 "hl"|"hoplimit"	{ return K_HOP_LIMIT; }
 
+	/* ICMPv6 */
+"mtype"		{ return K_MTYPE; }
+"code"		{ return K_CODE; }
+"echorequest"	{ return K_ECHO_REQUEST; }
+"echoreply"	{ return K_ECHO_REPLY; }
+
 	/* UDP */
 "sp"|"sport"	{ return K_SPORT; }
 "dp"|"dport"	{ return K_DPORT; }
@@ -186,6 +192,7 @@ ip6_addr	(({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:
 "arp"		{ return K_ARP; }
 "ip4"|"ipv4"	{ return K_IP4; }
 "ip6"|"ipv6"	{ return K_IP6; }
+"icmp6"|"icmpv6"	{ return K_ICMP6; }
 "udp"		{ return K_UDP; }
 "tcp"		{ return K_TCP; }
 
diff --git a/trafgen_parser.y b/trafgen_parser.y
index d6c9e70..bf57f47 100644
--- a/trafgen_parser.y
+++ b/trafgen_parser.y
@@ -20,6 +20,7 @@
 #include <net/if_arp.h>
 #include <netinet/in.h>
 #include <linux/if_ether.h>
+#include <linux/icmpv6.h>
 
 #include "xmalloc.h"
 #include "trafgen_parser.tab.h"
@@ -355,6 +356,7 @@ static void proto_add(enum proto_id pid)
 %token K_OPER K_SHA K_SPA K_THA K_TPA K_REQUEST K_REPLY K_PTYPE K_HTYPE
 %token K_PROT K_TTL K_DSCP K_ECN K_TOS K_LEN K_ID K_FLAGS K_FRAG K_IHL K_VER K_CSUM K_DF K_MF
 %token K_FLOW K_NEXT_HDR K_HOP_LIMIT
+%token K_MTYPE K_CODE K_ECHO_REQUEST K_ECHO_REPLY
 %token K_SPORT K_DPORT
 %token K_SEQ K_ACK_SEQ K_DOFF K_CWR K_ECE K_URG K_ACK K_PSH K_RST K_SYN K_FIN K_WINDOW K_URG_PTR
 %token K_TPID K_TCI K_PCP K_DEI K_1Q K_1AD
@@ -364,6 +366,7 @@ static void proto_add(enum proto_id pid)
 %token K_VLAN K_MPLS
 %token K_ARP
 %token K_IP4 K_IP6
+%token K_ICMP6
 %token K_UDP K_TCP
 
 %token ',' '{' '}' '(' ')' '[' ']' ':' '-' '+' '*' '/' '%' '&' '|' '<' '>' '^'
@@ -591,6 +594,7 @@ proto
 	| arp_proto { }
 	| ip4_proto { }
 	| ip6_proto { }
+	| icmpv6_proto { }
 	| udp_proto { }
 	| tcp_proto { }
 	;
@@ -812,6 +816,36 @@ ip6
 	: K_IP6	{ proto_add(PROTO_IP6); }
 	;
 
+icmpv6_proto
+	: icmp6 '(' icmp6_param_list ')' { }
+
+icmp6_param_list
+	: { }
+	| icmp6_field { }
+	| icmp6_field delimiter icmp6_param_list { }
+	;
+
+icmp6_field
+	: K_MTYPE skip_white '=' skip_white number
+		{ proto_field_set_u8(hdr, ICMPV6_TYPE, $5); }
+	| K_MTYPE skip_white '=' K_ECHO_REQUEST
+		{ proto_field_set_u8(hdr, ICMPV6_TYPE, ICMPV6_ECHO_REQUEST); }
+	| K_ECHO_REQUEST
+		{ proto_field_set_u8(hdr, ICMPV6_TYPE, ICMPV6_ECHO_REQUEST); }
+	| K_MTYPE skip_white '=' K_ECHO_REPLY
+		{ proto_field_set_u8(hdr, ICMPV6_TYPE, ICMPV6_ECHO_REPLY); }
+	| K_ECHO_REPLY
+		{ proto_field_set_u8(hdr, ICMPV6_TYPE, ICMPV6_ECHO_REPLY); }
+	| K_CODE skip_white '=' skip_white number
+		{ proto_field_set_u8(hdr, ICMPV6_CODE, $5); }
+	| K_CSUM skip_white '=' skip_white number
+		{ proto_field_set_be16(hdr, ICMPV6_CSUM, $5); }
+	;
+
+icmp6
+	: K_ICMP6 { proto_add(PROTO_ICMP6); }
+	;
+
 udp_proto
 	: udp '(' udp_param_list ')' { }
 	;
diff --git a/trafgen_proto.h b/trafgen_proto.h
index cdcffdc..5528704 100644
--- a/trafgen_proto.h
+++ b/trafgen_proto.h
@@ -17,6 +17,7 @@ enum proto_id {
 	PROTO_MPLS,
 	PROTO_IP4,
 	PROTO_IP6,
+	PROTO_ICMP6,
 	PROTO_UDP,
 	PROTO_TCP,
 };