ATM: Simplify protocol and message type handling.

In gen_atmfield_code_internal() the A_PROTOTYPE and A_MSGTYPE cases have
more arguments constant than it may seem.  Factor the former out to a
new function with lower arity, gen_atm_prototype(), and call it directly
as necessary.  Factor the latter out to gen_msg_abbrev() and there take
the message type value directly.  Remove 8 named constants and the
related entourage.

diff --git a/gencode.c b/gencode.c
index 9402a51fad2d5ab666a1cfa9a1836e845d674741..8d38bb2152153c1a55107938045b36d4bd9d9814 100644 (file)
--- a/gencode.c
+++ b/gencode.c
@@ -727,7 +727,8 @@ static struct block *gen_encap_ll_check(compiler_state_t *cstate);
 static struct block *gen_atmfield_code_internal(compiler_state_t *, int,
     bpf_u_int32, int, int);
 static struct block *gen_atmtype_llc(compiler_state_t *);
-static struct block *gen_msg_abbrev(compiler_state_t *, int type);
+static struct block *gen_msg_abbrev(compiler_state_t *, const uint8_t);
+static struct block *gen_atm_prototype(compiler_state_t *, const uint8_t);
 
 static void
 initchunks(compiler_state_t *cstate)
@@ -975,16 +976,8 @@ atmkw(const unsigned id)
                [A_OAM] = "oam",
                [A_OAMF4] = "oamf4",
                [A_LANE] = "lane",
-               // no keyword for A_SETUP
-               // no keyword for A_CALLPROCEED
-               // no keyword for A_CONNECT
-               // no keyword for A_CONNECTACK
-               // no keyword for A_RELEASE
-               // no keyword for A_RELEASE_DONE
                [A_VPI] = "vpi",
                [A_VCI] = "vci",
-               // no keyword for A_PROTOTYPE
-               // no keyword for A_MSGTYPE
                [A_CONNECTMSG] = "connectmsg",
                [A_METACONNECT] = "metaconnect",
        };
@@ -3656,7 +3649,7 @@ gen_linktype(compiler_state_t *cstate, bpf_u_int32 ll_proto)
                 *
                 * Check for LLC encapsulation and then check the protocol.
                 */
-               b0 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
+               b0 = gen_atm_prototype(cstate, PT_LLC);
                b1 = gen_llc_linktype(cstate, ll_proto);
                gen_and(b0, b1);
                return b1;
@@ -9726,14 +9719,6 @@ gen_atmfield_code_internal(compiler_state_t *cstate, int atmfield,
 {
        struct block *b0;
 
-       /*
-        * This check is a no-op for A_MSGTYPE so long as the only incoming
-        * code path is from gen_atmmulti_abbrev(), which makes the same
-        * check first; also for A_PROTOTYPE so long as the only incoming code
-        * paths are from gen_atmtype_abbrev(), which makes the same check
-        * first, or from gen_llc_internal() or gen_linktype(), which restrict
-        * it to DLT_SUNATM.
-        */
        assert_atm(cstate, atmkw(atmfield));
 
        switch (atmfield) {
@@ -9750,16 +9735,6 @@ gen_atmfield_code_internal(compiler_state_t *cstate, int atmfield,
                    0xffffffffU, jtype, reverse, jvalue);
                break;
 
-       case A_PROTOTYPE:
-               b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B,
-                   0x0fU, jtype, reverse, jvalue);
-               break;
-
-       case A_MSGTYPE:
-               b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_payload + MSG_TYPE_POS, BPF_B,
-                   0xffffffffU, jtype, reverse, jvalue);
-               break;
-
        default:
                abort();
        }
@@ -9788,12 +9763,18 @@ gen_atmtype_sc(compiler_state_t *cstate)
        return b1;
 }
 
+static struct block *
+gen_atm_prototype(compiler_state_t *cstate, const uint8_t v)
+{
+       return gen_mcmp(cstate, OR_LINKHDR, cstate->off_proto, BPF_B, v, 0x0fU);
+}
+
 static struct block *
 gen_atmtype_llc(compiler_state_t *cstate)
 {
        struct block *b0;
 
-       b0 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
+       b0 = gen_atm_prototype(cstate, PT_LLC);
        cstate->linktype = cstate->prevlinktype;
        return b0;
 }
@@ -9869,7 +9850,7 @@ gen_atmtype_abbrev(compiler_state_t *cstate, int type)
 
        case A_LANE:
                /* Get all LANE packets */
-               b1 = gen_atmfield_code_internal(cstate, A_PROTOTYPE, PT_LANE, BPF_JEQ, 0);
+               b1 = gen_atm_prototype(cstate, PT_LANE);
 
                /*
                 * Arrange that all subsequent tests assume LANE
@@ -10088,44 +10069,14 @@ gen_mtp3field_code(compiler_state_t *cstate, int mtp3field,
 }
 
 static struct block *
-gen_msg_abbrev(compiler_state_t *cstate, int type)
+gen_msg_abbrev(compiler_state_t *cstate, const uint8_t type)
 {
-       struct block *b1;
-
        /*
         * Q.2931 signalling protocol messages for handling virtual circuits
         * establishment and teardown
         */
-       switch (type) {
-
-       case A_SETUP:
-               b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, SETUP, BPF_JEQ, 0);
-               break;
-
-       case A_CALLPROCEED:
-               b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0);
-               break;
-
-       case A_CONNECT:
-               b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CONNECT, BPF_JEQ, 0);
-               break;
-
-       case A_CONNECTACK:
-               b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0);
-               break;
-
-       case A_RELEASE:
-               b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, RELEASE, BPF_JEQ, 0);
-               break;
-
-       case A_RELEASE_DONE:
-               b1 = gen_atmfield_code_internal(cstate, A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0);
-               break;
-
-       default:
-               abort();
-       }
-       return b1;
+       return gen_cmp(cstate, OR_LINKHDR, cstate->off_payload + MSG_TYPE_POS,
+           BPF_B, type);
 }
 
 struct block *
@@ -10167,30 +10118,30 @@ gen_atmmulti_abbrev(compiler_state_t *cstate, int type)
                 * Get Q.2931 signalling messages for switched
                 * virtual connection
                 */
-               b0 = gen_msg_abbrev(cstate, A_SETUP);
-               b1 = gen_msg_abbrev(cstate, A_CALLPROCEED);
+               b0 = gen_msg_abbrev(cstate, SETUP);
+               b1 = gen_msg_abbrev(cstate, CALL_PROCEED);
                gen_or(b0, b1);
-               b0 = gen_msg_abbrev(cstate, A_CONNECT);
+               b0 = gen_msg_abbrev(cstate, CONNECT);
                gen_or(b0, b1);
-               b0 = gen_msg_abbrev(cstate, A_CONNECTACK);
+               b0 = gen_msg_abbrev(cstate, CONNECT_ACK);
                gen_or(b0, b1);
-               b0 = gen_msg_abbrev(cstate, A_RELEASE);
+               b0 = gen_msg_abbrev(cstate, RELEASE);
                gen_or(b0, b1);
-               b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE);
+               b0 = gen_msg_abbrev(cstate, RELEASE_DONE);
                gen_or(b0, b1);
                b0 = gen_atmtype_sc(cstate);
                gen_and(b0, b1);
                break;
 
        case A_METACONNECT:
-               b0 = gen_msg_abbrev(cstate, A_SETUP);
-               b1 = gen_msg_abbrev(cstate, A_CALLPROCEED);
+               b0 = gen_msg_abbrev(cstate, SETUP);
+               b1 = gen_msg_abbrev(cstate, CALL_PROCEED);
                gen_or(b0, b1);
-               b0 = gen_msg_abbrev(cstate, A_CONNECT);
+               b0 = gen_msg_abbrev(cstate, CONNECT);
                gen_or(b0, b1);
-               b0 = gen_msg_abbrev(cstate, A_RELEASE);
+               b0 = gen_msg_abbrev(cstate, RELEASE);
                gen_or(b0, b1);
-               b0 = gen_msg_abbrev(cstate, A_RELEASE_DONE);
+               b0 = gen_msg_abbrev(cstate, RELEASE_DONE);
                gen_or(b0, b1);
                b0 = gen_atmtype_metac(cstate);
                gen_and(b0, b1);

diff --git a/gencode.h b/gencode.h
index 7e7d499e4412b10d9dde6c7c803e5a744b5887e0..398a69ac2de51220bba8cedc4e9bcffe517141f4 100644 (file)
--- a/gencode.h
+++ b/gencode.h
@@ -161,19 +161,9 @@
 #define A_OAMF4                29      /* OAM F4 cells: Segment + End-to-end */
 #define A_LANE         30      /* LANE traffic */
 
-/* Based on Q.2931 signalling protocol */
-#define A_SETUP                41      /* Setup message */
-#define A_CALLPROCEED  42      /* Call proceeding message */
-#define A_CONNECT      43      /* Connect message */
-#define A_CONNECTACK   44      /* Connect Ack message */
-#define A_RELEASE      45      /* Release message */
-#define A_RELEASE_DONE 46      /* Release message */
-
 /* ATM field types */
 #define A_VPI          51
 #define A_VCI          52
-#define A_PROTOTYPE    53
-#define A_MSGTYPE      54
 
 #define A_CONNECTMSG   70      /* returns Q.2931 signalling messages for
                                   establishing and destroying switched