tcpopts: clean up parser -> tcpopt.c plumbing

tcpopt template mapping is asymmetric:
one mapping is to match dumped netlink exthdr expression to the original
tcp option template.

This struct is indexed by the raw, on-write kind/type number.

The other mapping maps parsed options to the tcp option template.
Remove the latter.  The parser is changed to translate the textual
option name, e.g. "maxseg" to the on-wire number.

This avoids the second mapping, it will also allow to more easily
support raw option matching in a followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>

1 files changed, 35 insertions, 57 deletions

diff --git a/src/tcpopt.c b/src/tcpopt.c
index 6dbaa9e6..8d5bdec5 100644
--- a/src/tcpopt.c
+++ b/src/tcpopt.c
@@ -20,7 +20,7 @@ static const struct proto_hdr_template tcpopt_unknown_template =
 			   __offset, __len)
 static const struct exthdr_desc tcpopt_eol = {
 	.name		= "eol",
-	.type		= TCPOPT_EOL,
+	.type		= TCPOPT_KIND_EOL,
 	.templates	= {
 		[TCPOPTHDR_FIELD_KIND]		= PHT("kind",  0,    8),
 	},
@@ -28,7 +28,7 @@ static const struct exthdr_desc tcpopt_eol = {
 
 static const struct exthdr_desc tcpopt_nop = {
 	.name		= "noop",
-	.type		= TCPOPT_NOP,
+	.type		= TCPOPT_KIND_NOP,
 	.templates	= {
 		[TCPOPTHDR_FIELD_KIND]		= PHT("kind",   0,   8),
 	},
@@ -36,7 +36,7 @@ static const struct exthdr_desc tcpopt_nop = {
 
 static const struct exthdr_desc tcptopt_maxseg = {
 	.name		= "maxseg",
-	.type		= TCPOPT_MAXSEG,
+	.type		= TCPOPT_KIND_MAXSEG,
 	.templates	= {
 		[TCPOPTHDR_FIELD_KIND]		= PHT("kind",   0,  8),
 		[TCPOPTHDR_FIELD_LENGTH]	= PHT("length", 8,  8),
@@ -46,7 +46,7 @@ static const struct exthdr_desc tcptopt_maxseg = {
 
 static const struct exthdr_desc tcpopt_window = {
 	.name		= "window",
-	.type		= TCPOPT_WINDOW,
+	.type		= TCPOPT_KIND_WINDOW,
 	.templates	= {
 		[TCPOPTHDR_FIELD_KIND]		= PHT("kind",   0,  8),
 		[TCPOPTHDR_FIELD_LENGTH]	= PHT("length", 8,  8),
@@ -56,7 +56,7 @@ static const struct exthdr_desc tcpopt_window = {
 
 static const struct exthdr_desc tcpopt_sack_permitted = {
 	.name		= "sack-perm",
-	.type		= TCPOPT_SACK_PERMITTED,
+	.type		= TCPOPT_KIND_SACK_PERMITTED,
 	.templates	= {
 		[TCPOPTHDR_FIELD_KIND]		= PHT("kind",   0, 8),
 		[TCPOPTHDR_FIELD_LENGTH]	= PHT("length", 8, 8),
@@ -65,7 +65,7 @@ static const struct exthdr_desc tcpopt_sack_permitted = {
 
 static const struct exthdr_desc tcpopt_sack = {
 	.name		= "sack",
-	.type		= TCPOPT_SACK,
+	.type		= TCPOPT_KIND_SACK,
 	.templates	= {
 		[TCPOPTHDR_FIELD_KIND]		= PHT("kind",   0,   8),
 		[TCPOPTHDR_FIELD_LENGTH]		= PHT("length", 8,   8),
@@ -76,7 +76,7 @@ static const struct exthdr_desc tcpopt_sack = {
 
 static const struct exthdr_desc tcpopt_timestamp = {
 	.name		= "timestamp",
-	.type		= TCPOPT_TIMESTAMP,
+	.type		= TCPOPT_KIND_TIMESTAMP,
 	.templates	= {
 		[TCPOPTHDR_FIELD_KIND]		= PHT("kind",   0,  8),
 		[TCPOPTHDR_FIELD_LENGTH]	= PHT("length", 8,  8),
@@ -86,19 +86,14 @@ static const struct exthdr_desc tcpopt_timestamp = {
 };
 #undef PHT
 
-#define TCPOPT_OBSOLETE ((struct exthdr_desc *)NULL)
-#define TCPOPT_ECHO 6
-#define TCPOPT_ECHO_REPLY 7
-static const struct exthdr_desc *tcpopt_protocols[] = {
-	[TCPOPT_EOL]		= &tcpopt_eol,
-	[TCPOPT_NOP]		= &tcpopt_nop,
-	[TCPOPT_MAXSEG]		= &tcptopt_maxseg,
-	[TCPOPT_WINDOW]		= &tcpopt_window,
-	[TCPOPT_SACK_PERMITTED]	= &tcpopt_sack_permitted,
-	[TCPOPT_SACK]		= &tcpopt_sack,
-	[TCPOPT_ECHO]		= TCPOPT_OBSOLETE,
-	[TCPOPT_ECHO_REPLY]	= TCPOPT_OBSOLETE,
-	[TCPOPT_TIMESTAMP]	= &tcpopt_timestamp,
+const struct exthdr_desc *tcpopt_protocols[] = {
+	[TCPOPT_KIND_EOL]		= &tcpopt_eol,
+	[TCPOPT_KIND_NOP]		= &tcpopt_nop,
+	[TCPOPT_KIND_MAXSEG]		= &tcptopt_maxseg,
+	[TCPOPT_KIND_WINDOW]		= &tcpopt_window,
+	[TCPOPT_KIND_SACK_PERMITTED]	= &tcpopt_sack_permitted,
+	[TCPOPT_KIND_SACK]		= &tcpopt_sack,
+	[TCPOPT_KIND_TIMESTAMP]		= &tcpopt_timestamp,
 };
 
 static unsigned int calc_offset(const struct exthdr_desc *desc,
@@ -136,51 +131,34 @@ static unsigned int calc_offset_reverse(const struct exthdr_desc *desc,
 	}
 }
 
-const struct exthdr_desc *tcpopthdr_protocols[__TCPOPTHDR_MAX] = {
-	[TCPOPTHDR_EOL]			= &tcpopt_eol,
-	[TCPOPTHDR_NOOP]		= &tcpopt_nop,
-	[TCPOPTHDR_MAXSEG]		= &tcptopt_maxseg,
-	[TCPOPTHDR_WINDOW]		= &tcpopt_window,
-	[TCPOPTHDR_SACK_PERMITTED]	= &tcpopt_sack_permitted,
-	[TCPOPTHDR_SACK0]		= &tcpopt_sack,
-	[TCPOPTHDR_SACK1]		= &tcpopt_sack,
-	[TCPOPTHDR_SACK2]		= &tcpopt_sack,
-	[TCPOPTHDR_SACK3]		= &tcpopt_sack,
-	[TCPOPTHDR_ECHO]		= TCPOPT_OBSOLETE,
-	[TCPOPTHDR_ECHO_REPLY]		= TCPOPT_OBSOLETE,
-	[TCPOPTHDR_TIMESTAMP]		= &tcpopt_timestamp,
-};
-
-static uint8_t tcpopt_optnum[] = {
-	[TCPOPTHDR_SACK0]	= 0,
-	[TCPOPTHDR_SACK1]	= 1,
-	[TCPOPTHDR_SACK2]	= 2,
-	[TCPOPTHDR_SACK3]	= 3,
-};
-
-static uint8_t tcpopt_find_optnum(uint8_t optnum)
-{
-	if (optnum > TCPOPTHDR_SACK3)
-		return 0;
-
-	return tcpopt_optnum[optnum];
-}
-
-struct expr *tcpopt_expr_alloc(const struct location *loc, uint8_t type,
-			       uint8_t field)
+struct expr *tcpopt_expr_alloc(const struct location *loc,
+			       unsigned int kind,
+			       unsigned int field)
 {
 	const struct proto_hdr_template *tmpl;
 	const struct exthdr_desc *desc;
+	uint8_t optnum = 0;
 	struct expr *expr;
-	uint8_t optnum;
 
-	desc = tcpopthdr_protocols[type];
+	switch (kind) {
+	case TCPOPT_KIND_SACK1:
+		kind = TCPOPT_KIND_SACK;
+		optnum = 1;
+		break;
+	case TCPOPT_KIND_SACK2:
+		kind = TCPOPT_KIND_SACK;
+		optnum = 2;
+		break;
+	case TCPOPT_KIND_SACK3:
+		kind = TCPOPT_KIND_SACK;
+		optnum = 3;
+	}
+
+	desc = tcpopt_protocols[kind];
 	tmpl = &desc->templates[field];
 	if (!tmpl)
 		return NULL;
 
-	optnum = tcpopt_find_optnum(type);
-
 	expr = expr_alloc(loc, EXPR_EXTHDR, tmpl->dtype,
 			  BYTEORDER_BIG_ENDIAN, tmpl->len);
 	expr->exthdr.desc   = desc;
@@ -206,7 +184,7 @@ void tcpopt_init_raw(struct expr *expr, uint8_t type, unsigned int offset,
 	assert(type < array_size(tcpopt_protocols));
 	expr->exthdr.desc = tcpopt_protocols[type];
 	expr->exthdr.flags = flags;
-	assert(expr->exthdr.desc != TCPOPT_OBSOLETE);
+	assert(expr->exthdr.desc != NULL);
 
 	for (i = 0; i < array_size(expr->exthdr.desc->templates); ++i) {
 		tmpl = &expr->exthdr.desc->templates[i];