added 3 bmv2 examples: copy_to_cpu, meter, TLV_parsing

examples/TLV_parsing/p4src/TLV_parsing.p4

@@ -0,0 +1,227 @@
+header_type ethernet_t {
+    fields {
+        dstAddr : 48;
+        srcAddr : 48;
+        etherType : 16;
+    }
+}
+
+header_type ipv4_base_t {
+    fields {
+        version : 4; 
+        ihl : 4;
+        diffserv : 8;
+        totalLen : 16;
+        identification : 16;
+        flags : 3;
+        fragOffset : 13;
+        ttl : 8;
+        protocol : 8;
+        hdrChecksum : 16;
+        srcAddr : 32;
+        dstAddr : 32;
+    }
+}
+
+// End of Option List
+#define IPV4_OPTION_EOL_VALUE 0x00
+header_type ipv4_option_EOL_t {
+    fields {
+        value : 8;
+    }
+}
+
+// No operation
+#define IPV4_OPTION_NOP_VALUE 0x01
+header_type ipv4_option_NOP_t {
+    fields {
+        value : 8;
+    }
+}
+
+#define IPV4_OPTION_SECURITY_VALUE 0x82
+header_type ipv4_option_security_t {
+    fields {
+        value : 8;
+        len : 8;
+        security : 72;
+    }
+}
+
+#define IPV4_OPTION_TIMESTAMP_VALUE 0x44
+header_type ipv4_option_timestamp_t {
+    fields {
+        value : 8;
+        len : 8;
+        data : *;
+    }
+    length : len;
+    max_length : 40;
+}
+
+header_type intrinsic_metadata_t {
+    fields {
+        mcast_grp : 4;
+        egress_rid : 4;
+        mcast_hash : 16;
+        lf_field_list: 32;
+    }
+}
+
+header_type my_metadata_t {
+    fields {
+        parse_ipv4_counter : 8;
+    }
+}
+
+header ethernet_t ethernet;
+header ipv4_base_t ipv4_base;
+header ipv4_option_EOL_t ipv4_option_EOL[3];
+header ipv4_option_NOP_t ipv4_option_NOP[3];
+header ipv4_option_security_t ipv4_option_security;
+header ipv4_option_timestamp_t ipv4_option_timestamp;
+metadata intrinsic_metadata_t intrinsic_metadata;
+metadata my_metadata_t my_metadata;
+
+@pragma header_ordering ethernet ipv4_base ipv4_option_security ipv4_option_NOP ipv4_option_timestamp ipv4_option_EOL
+parser start {
+    return parse_ethernet;
+}
+
+#define ETHERTYPE_IPV4 0x0800
+parser parse_ethernet {
+    extract(ethernet);
+    return select(ethernet.etherType) {
+        ETHERTYPE_IPV4 : parse_ipv4;
+        default: ingress;   
+    }
+}
+
+parser parse_ipv4 {
+    extract(ipv4_base);
+    set_metadata(my_metadata.parse_ipv4_counter, ipv4_base.ihl * 4 - 20);
+    return select(ipv4_base.ihl) {
+        0x05 : ingress;
+        default : parse_ipv4_options;
+    }
+}
+
+parser parse_ipv4_options {
+    // match on byte counter and option value
+    return select(my_metadata.parse_ipv4_counter, current(0, 8)) {
+        0x0000 mask 0xff00 : ingress;
+        0x0000 mask 0x00ff : parse_ipv4_option_EOL;
+        0x0001 mask 0x00ff : parse_ipv4_option_NOP;
+        0x0082 mask 0x00ff : parse_ipv4_option_security;
+        0x0044 mask 0x00ff : parse_ipv4_option_timestamp;
+    }
+}
+
+parser parse_ipv4_option_EOL {
+    extract(ipv4_option_EOL[next]);
+    set_metadata(my_metadata.parse_ipv4_counter,
+                 my_metadata.parse_ipv4_counter - 1);
+    return parse_ipv4_options;
+}
+
+parser parse_ipv4_option_NOP {
+    extract(ipv4_option_NOP[next]);
+    set_metadata(my_metadata.parse_ipv4_counter,
+                 my_metadata.parse_ipv4_counter - 1);
+    return parse_ipv4_options;
+}
+
+parser parse_ipv4_option_security {
+    extract(ipv4_option_security);
+    // security option must have length 11 bytes
+    set_metadata(my_metadata.parse_ipv4_counter,
+                 my_metadata.parse_ipv4_counter - 11);
+    return parse_ipv4_options;
+}
+
+parser parse_ipv4_option_timestamp {
+    extract(ipv4_option_timestamp);
+    set_metadata(my_metadata.parse_ipv4_counter,
+                 my_metadata.parse_ipv4_counter - ipv4_option_timestamp.len);
+    return parse_ipv4_options;
+}
+
+field_list ipv4_checksum_list {
+        ipv4_base.version;
+        ipv4_base.ihl;
+        ipv4_base.diffserv;
+        ipv4_base.totalLen;
+        ipv4_base.identification;
+        ipv4_base.flags;
+        ipv4_base.fragOffset;
+        ipv4_base.ttl;
+        ipv4_base.protocol;
+        ipv4_base.srcAddr;
+        ipv4_base.dstAddr;
+        ipv4_option_security;
+        ipv4_option_NOP[0];
+        ipv4_option_timestamp;        
+}
+
+field_list_calculation ipv4_checksum {
+    input {
+        ipv4_checksum_list;
+    }
+    algorithm : csum16;
+    output_width : 16;
+}
+
+calculated_field ipv4_base.hdrChecksum  {
+    update ipv4_checksum;
+}
+
+action _drop() {
+    drop();
+}
+
+action _nop() {
+}
+
+control ingress {
+
+}
+
+action format_options_security() {
+    pop(ipv4_option_NOP, 3);
+    pop(ipv4_option_EOL, 3);
+    push(ipv4_option_EOL, 1);
+    modify_field(ipv4_base.ihl, 8);
+}
+
+action format_options_timestamp() {
+    pop(ipv4_option_NOP, 3);
+    pop(ipv4_option_EOL, 3);
+    // timestamp option is word-aligned so no need for NOP or EOL
+    modify_field(ipv4_base.ihl, 5 + (ipv4_option_timestamp.len >> 3));
+}
+
+action format_options_both() {
+    pop(ipv4_option_NOP, 3);
+    pop(ipv4_option_EOL, 3);
+    push(ipv4_option_NOP, 1);
+    modify_field(ipv4_option_NOP[0].value, IPV4_OPTION_NOP_VALUE);
+    modify_field(ipv4_base.ihl, 8 + (ipv4_option_timestamp.len >> 2));
+}
+
+table format_options {
+    reads {
+        ipv4_option_security : valid;
+        ipv4_option_timestamp : valid;
+    }
+    actions {
+        format_options_security;
+        format_options_timestamp;
+        format_options_both;
+        _nop;
+    }
+    size : 4;
+}
+
+control egress {
+    apply(format_options);
+}