trafgen: parser: Add syntax to generate Ethernet header fields

Add function 'eth()' to support generating Ethernet header fields from the
trafgen configuration language.

Supported fields:

    da|daddr    destination address, default: 00:00:00:00:00:00
    sa|saddr    source address, default: device MAC
    prot|proto  protocol number, default: 0x0000

Example usage:

    { eth(prot=0x0800, da=11:22:33:44:55:66), fill(0xff, 60) }
    { eth(prot=0x0800) }
    { eth() }

It is important that proto_init is called before fields will be filled
to initialize the specified proto with header fields.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
[tk: document supported keywords in commit message]
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

2 files changed, 71 insertions, 1 deletions

diff --git a/trafgen_lexer.l b/trafgen_lexer.l
index 6c27b0c..d209116 100644
--- a/trafgen_lexer.l
+++ b/trafgen_lexer.l
@@ -19,6 +19,7 @@
 #include "trafgen_parser.tab.h"
 #include "xmalloc.h"
 #include "built_in.h"
+#include "str.h"
 
 extern void yyerror(const char *);
 
@@ -75,6 +76,9 @@ number_bin	([0]?[b][0-1]+)
 number_dec	(([0])|([1-9][0-9]*))
 number_ascii	([a-zA-Z])
 
+mac_hex		([a-fA-F0-9]+)
+mac		({mac_hex}:{mac_hex}:{mac_hex}:{mac_hex}:{mac_hex}:{mac_hex})
+
 %%
 
 "cpu"		{ return K_CPU; }
@@ -99,6 +103,12 @@ number_ascii	([a-zA-Z])
 "const32"|"c32"	{ return K_CONST32; }
 "const64"|"c64"	{ return K_CONST64; }
 
+"daddr"|"da"	{ return K_DADDR; }
+"saddr"|"sa"	{ return K_SADDR; }
+"prot"[o]?	{ return K_PROT; }
+
+"eth"		{ return K_ETH; }
+
 [ ]*"-"[ ]*	{ return '-'; }
 [ ]*"+"[ ]*	{ return '+'; }
 [ ]*"*"[ ]*	{ return '*'; }
@@ -117,6 +127,7 @@ number_ascii	([a-zA-Z])
 "]"		{ return ']'; }
 ","		{ return ','; }
 ":"		{ return ':'; }
+"="		{ return '='; }
 
 "\n"		{ yylineno++; }
 
@@ -146,6 +157,10 @@ number_ascii	([a-zA-Z])
 {number_ascii}	{ yylval.number = (uint8_t) (*yytext);
 		  return number; }
 
+{mac}	        { if (str2mac(yytext, yylval.bytes, 256))
+			panic("Failed to parse MAC address %s\n", yytext);
+		  return mac; }
+
 "'\\x"[a-fA-F0-9]{2}"'" { yylval.number = strtol(yytext + 3, NULL, 16);
 		  return number; }
 
diff --git a/trafgen_parser.y b/trafgen_parser.y
index 4725f7c..df1b1a6 100644
--- a/trafgen_parser.y
+++ b/trafgen_parser.y
@@ -21,6 +21,8 @@
 #include "xmalloc.h"
 #include "trafgen_parser.tab.h"
 #include "trafgen_conf.h"
+#include "trafgen_proto.h"
+#include "trafgen_l2.h"
 #include "built_in.h"
 #include "die.h"
 #include "str.h"
@@ -59,6 +61,8 @@ extern size_t dlen;
 
 static int our_cpu, min_cpu = -1, max_cpu = -1;
 
+static struct proto_hdr *hdr;
+
 static inline int test_ignore(void)
 {
 	if (min_cpu < 0 && max_cpu < 0)
@@ -324,22 +328,33 @@ static void set_dynamic_incdec(uint8_t start, uint8_t stop, uint8_t stepping,
 	__setup_new_counter(&pktd->cnt[packetdc_last], start, stop, stepping, type);
 }
 
+static void proto_add(enum proto_id pid)
+{
+	proto_header_init(pid);
+	hdr = proto_current_header();
+}
+
 %}
 
 %union {
 	long long int number;
+	uint8_t bytes[256];
 	char *str;
 }
 
 %token K_COMMENT K_FILL K_RND K_SEQINC K_SEQDEC K_DRND K_DINC K_DDEC K_WHITE
 %token K_CPU K_CSUMIP K_CSUMUDP K_CSUMTCP K_CSUMUDP6 K_CSUMTCP6 K_CONST8 K_CONST16 K_CONST32 K_CONST64
 
+%token K_DADDR K_SADDR K_PROT
+%token K_ETH
+
 %token ',' '{' '}' '(' ')' '[' ']' ':' '-' '+' '*' '/' '%' '&' '|' '<' '>' '^'
 
-%token number string
+%token number string mac
 
 %type <number> number expression
 %type <str> string
+%type <bytes> mac
 
 %left '-' '+' '*' '/' '%' '&' '|' '<' '>' '^'
 
@@ -372,9 +387,16 @@ noenforce_white
 	| delimiter_nowhite { }
 	;
 
+skip_white
+	: { }
+	| K_WHITE { }
+	;
 packet
 	: '{' noenforce_white payload noenforce_white '}' {
 			min_cpu = max_cpu = -1;
+
+			proto_packet_finish();
+
 			realloc_packet();
 		}
 	| K_CPU '(' number cpu_delim number ')' ':' noenforce_white '{' noenforce_white payload noenforce_white '}' {
@@ -388,10 +410,15 @@ packet
 				max_cpu = tmp;
 			}
 
+			proto_packet_finish();
+
 			realloc_packet();
 		}
 	| K_CPU '(' number ')' ':' noenforce_white '{' noenforce_white payload noenforce_white '}' {
 			min_cpu = max_cpu = $3;
+
+			proto_packet_finish();
+
 			realloc_packet();
 		}
 	;
@@ -422,6 +449,7 @@ elem
 	| ddec { }
 	| csum { }
 	| const { }
+	| proto { proto_header_finish(hdr); }
 	| inline_comment { }
 	;
 
@@ -536,6 +564,33 @@ ddec
 		{ set_dynamic_incdec($3, $5, $7, TYPE_DEC); }
 	;
 
+proto
+	: eth_proto { }
+	;
+
+eth_proto
+	: eth '(' eth_param_list ')' { }
+	;
+
+eth
+	: K_ETH	{ proto_add(PROTO_ETH); }
+	;
+
+eth_param_list
+	: { }
+	| eth_field { }
+	| eth_field delimiter eth_param_list { }
+	;
+
+eth_field
+	: K_DADDR  skip_white '=' skip_white mac
+		{ proto_field_set_bytes(hdr, ETH_DST_ADDR, $5); }
+	| K_SADDR  skip_white '=' skip_white mac
+		{ proto_field_set_bytes(hdr, ETH_SRC_ADDR, $5); }
+	| K_PROT skip_white '=' skip_white number
+		{ proto_field_set_be16(hdr, ETH_PROTO_ID, $5); }
+	;
+
 %%
 
 static void finalize_packet(void)