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WIP/RFC possible use of va_list in gencode.c #1520

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121 changes: 78 additions & 43 deletions gencode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -640,6 +640,9 @@ static struct block *gen_set(compiler_state_t *, bpf_u_int32, struct slist *);
static struct block *gen_unset(compiler_state_t *, bpf_u_int32, struct slist *);
static struct block *gen_ncmp(compiler_state_t *, enum e_offrel, u_int,
u_int, bpf_u_int32, int, int, bpf_u_int32);
static struct block *gen_vncmp(compiler_state_t *, const enum e_offrel,
const u_int, const u_int, const bpf_u_int32, const int, const unsigned,
uint8_t, va_list);
static struct slist *gen_load_absoffsetrel(compiler_state_t *, bpf_abs_offset *,
u_int, u_int);
static struct slist *gen_load_a(compiler_state_t *, enum e_offrel, u_int,
Expand Down Expand Up @@ -713,7 +716,7 @@ 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 *, const uint8_t);
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 struct block *gen_atm_vpi(compiler_state_t *, const uint8_t);
static struct block *gen_atm_vci(compiler_state_t *, const uint16_t);
Expand Down Expand Up @@ -1391,11 +1394,34 @@ gen_not(struct block *b)
b->sense = !b->sense;
}

static struct block *
gen_ncmp_any(compiler_state_t *cstate, const enum e_offrel offrel,
const u_int offset, const u_int size, const bpf_u_int32 mask,
const int jtype, const unsigned reverse, const uint8_t nval, ...)
{
va_list ap;
va_start(ap, nval);
struct block *b = gen_vncmp(cstate, offrel, offset, size, mask, jtype, reverse, nval, ap);
va_end(ap);
return b;
}

static struct block *
gen_cmp_any(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
u_int size, const uint8_t nval, ...)
{
va_list ap;
va_start(ap, nval);
struct block *b = gen_vncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JEQ, 0, nval, ap);
va_end(ap);
return b;
}

static struct block *
gen_cmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
u_int size, bpf_u_int32 v)
{
return gen_ncmp(cstate, offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v);
return gen_cmp_any(cstate, offrel, offset, size, 1, v);
}

static struct block *
Expand Down Expand Up @@ -1530,6 +1556,7 @@ gen_ncmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
u_int size, bpf_u_int32 mask, int jtype, int reverse,
bpf_u_int32 v)
{
// return gen_ncmp_va(cstate, offrel, offset, size, mask, jtype, reverse, 1, v);
struct slist *s, *s2;
struct block *b;

Expand All @@ -1547,6 +1574,40 @@ gen_ncmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
return b;
}

// Test whether any of the specified values satisfies the condition.
static struct block *
gen_vncmp(compiler_state_t *cstate, const enum e_offrel offrel,
const u_int offset, const u_int size, const bpf_u_int32 mask,
const int jtype, const unsigned reverse, uint8_t nval, va_list ap)
{
struct slist *s = gen_load_a(cstate, offrel, offset, size);

if (mask != UINT32_MAX) {
struct slist *s2 = new_stmt(cstate, BPF_ALU|BPF_AND|BPF_K);
s2->s.k = mask;
sappend(s, s2);
}

if (! nval)
bpf_error(cstate, "Internal error in %s", __func__);

struct block *b = NULL;
while (nval--) {
bpf_u_int32 v = va_arg(ap, bpf_u_int32);
if (! b) {
b = gen_jmp(cstate, jtype, v, s);
} else {
struct block *tmp = gen_jmp(cstate, jtype, v, NULL);
gen_or(b, tmp);
b = tmp;
}
}

if (reverse)
gen_not(b);
return b;
}

static int
init_linktype(compiler_state_t *cstate, pcap_t *p)
{
Expand Down Expand Up @@ -3725,12 +3786,8 @@ gen_linktype(compiler_state_t *cstate, bpf_u_int32 ll_proto)
* Also check for Van Jacobson-compressed IP.
* XXX - do this for other forms of PPP?
*/
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_IP);
b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJC);
gen_or(b0, b1);
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H, PPP_VJNC);
gen_or(b1, b0);
return b0;
return gen_cmp_any(cstate, OR_LINKTYPE, 0, BPF_H, 3,
PPP_IP, PPP_VJC, PPP_VJNC);

default:
return gen_cmp(cstate, OR_LINKTYPE, 0, BPF_H,
Expand Down Expand Up @@ -3847,20 +3904,12 @@ gen_linktype(compiler_state_t *cstate, bpf_u_int32 ll_proto)
ARCTYPE_INET6));

case ETHERTYPE_IP:
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
ARCTYPE_IP);
b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
ARCTYPE_IP_OLD);
gen_or(b0, b1);
return (b1);
return gen_cmp_any(cstate, OR_LINKTYPE, 0, BPF_B,
2, ARCTYPE_IP, ARCTYPE_IP_OLD);

case ETHERTYPE_ARP:
b0 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
ARCTYPE_ARP);
b1 = gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
ARCTYPE_ARP_OLD);
gen_or(b0, b1);
return (b1);
return gen_cmp_any(cstate, OR_LINKTYPE, 0, BPF_B,
2, ARCTYPE_ARP, ARCTYPE_ARP_OLD);

case ETHERTYPE_REVARP:
return (gen_cmp(cstate, OR_LINKTYPE, 0, BPF_B,
Expand Down Expand Up @@ -9801,14 +9850,18 @@ gen_mtp3field_code(compiler_state_t *cstate, int mtp3field,
}

static struct block *
gen_msg_abbrev(compiler_state_t *cstate, const uint8_t type)
gen_msg_abbrev(compiler_state_t *cstate, const uint8_t nval, ...)
{
/*
* Q.2931 signalling protocol messages for handling virtual circuits
* establishment and teardown
*/
return gen_cmp(cstate, OR_LINKHDR, cstate->off_payload + MSG_TYPE_POS,
BPF_B, type);
va_list ap;
va_start(ap, nval);
struct block *b = gen_vncmp(cstate, OR_LINKHDR, cstate->off_payload + MSG_TYPE_POS,
BPF_B, 0xffffffff, BPF_JEQ, 0, nval, ap);
va_end(ap);
return b;
}

struct block *
Expand Down Expand Up @@ -9850,31 +9903,13 @@ gen_atmmulti_abbrev(compiler_state_t *cstate, int type)
* Get Q.2931 signalling messages for switched
* virtual connection
*/
b0 = gen_msg_abbrev(cstate, SETUP);
b1 = gen_msg_abbrev(cstate, CALL_PROCEED);
gen_or(b0, b1);
b0 = gen_msg_abbrev(cstate, CONNECT);
gen_or(b0, b1);
b0 = gen_msg_abbrev(cstate, CONNECT_ACK);
gen_or(b0, b1);
b0 = gen_msg_abbrev(cstate, RELEASE);
gen_or(b0, b1);
b0 = gen_msg_abbrev(cstate, RELEASE_DONE);
gen_or(b0, b1);
b1 = gen_msg_abbrev(cstate, 6, RELEASE_DONE, RELEASE, CONNECT_ACK, CONNECT, SETUP, CALL_PROCEED);
b0 = gen_atmtype_abbrev(cstate, A_SC);
gen_and(b0, b1);
return b1;

case A_METACONNECT:
b0 = gen_msg_abbrev(cstate, SETUP);
b1 = gen_msg_abbrev(cstate, CALL_PROCEED);
gen_or(b0, b1);
b0 = gen_msg_abbrev(cstate, CONNECT);
gen_or(b0, b1);
b0 = gen_msg_abbrev(cstate, RELEASE);
gen_or(b0, b1);
b0 = gen_msg_abbrev(cstate, RELEASE_DONE);
gen_or(b0, b1);
b1 = gen_msg_abbrev(cstate, 5, RELEASE_DONE, RELEASE, CONNECT, SETUP, CALL_PROCEED);
b0 = gen_atmtype_abbrev(cstate, A_METAC);
gen_and(b0, b1);
return b1;
Expand Down
16 changes: 13 additions & 3 deletions testprogs/TESTrun
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Original file line number Diff line number Diff line change
Expand Up @@ -2444,7 +2444,7 @@ my @accept_blocks = (
name => 'atm_connectmsg',
DLT => 'SUNATM',
aliases => ['connectmsg'],
opt => '
unopt => '
(000) ldb [1]
(001) jeq #0x0 jt 2 jf 12
(002) ldh [2]
Expand All @@ -2464,7 +2464,7 @@ my @accept_blocks = (
name => 'atm_metaconnect',
DLT => 'SUNATM',
aliases => ['metaconnect'],
opt => '
unopt => '
(000) ldb [1]
(001) jeq #0x0 jt 2 jf 11
(002) ldh [2]
Expand Down Expand Up @@ -3920,7 +3920,7 @@ my @accept_blocks = (
name => 'link_proto_ip_PPP_BSDOS',
DLT => 'PPP_BSDOS',
aliases => ['link proto \ip'],
opt => '
unopt => '
(000) ldh [5]
(001) jeq #0x21 jt 4 jf 2
(002) jeq #0x2d jt 4 jf 3
Expand Down Expand Up @@ -5568,6 +5568,16 @@ my @accept_blocks = (
(004) ret #262144
(005) ret #0
',
unopt => '
(000) ldh [12]
(001) jeq #0x8100 jt 6 jf 2
(002) ldh [12]
(003) jeq #0x88a8 jt 6 jf 4
(004) ldh [12]
(005) jeq #0x9100 jt 6 jf 7
(006) ret #262144
(007) ret #0
',
}, # vlan_eth_nullary
{
name => 'vlan_eth_unary',
Expand Down