aboutsummaryrefslogtreecommitdiff
path: root/scripts
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2015-08-05 12:54:45 +0100
committerDavid Howells <dhowells@redhat.com>2015-08-05 12:54:45 +0100
commit8d9b21dcfe6814c92c9f445a7c742b7bab4f86b8 (patch)
treef8d75cab8ef32c8268b44025ce8cf512d9b420b8 /scripts
parent52721d9d3334c1cb1f76219a161084094ec634dc (diff)
downloadlinux-stericsson-8d9b21dcfe6814c92c9f445a7c742b7bab4f86b8.tar.gz
ASN.1: Fix handling of CHOICE in ASN.1 compiler
Fix the handling of CHOICE types in the ASN.1 compiler to make SEQUENCE and SET elements in a CHOICE be correctly rendered as skippable and conditional as appropriate. For example, in the following ASN.1: Foo ::= SEQUENCE { w1 INTEGER, w2 Bar, w3 OBJECT IDENTIFIER } Bar ::= CHOICE { x1 Seq1, x2 [0] IMPLICIT OCTET STRING, x3 Seq2, x4 SET OF INTEGER } Seq1 ::= SEQUENCE { y1 INTEGER, y2 INTEGER, y3 INTEGER } Seq2 ::= SEQUENCE { z1 BOOLEAN, z2 BOOLEAN, z3 BOOLEAN } the output in foo.c generated by: ./scripts/asn1_compiler foo.asn1 foo.c foo.h included: // Bar // Seq1 [ 4] = ASN1_OP_MATCH, [ 5] = _tag(UNIV, CONS, SEQ), ... [ 13] = ASN1_OP_COND_MATCH_OR_SKIP, // x2 [ 14] = _tagn(CONT, PRIM, 0), // Seq2 [ 15] = ASN1_OP_MATCH, [ 16] = _tag(UNIV, CONS, SEQ), ... [ 24] = ASN1_OP_COND_MATCH_JUMP_OR_SKIP, // x4 [ 25] = _tag(UNIV, CONS, SET), ... [ 27] = ASN1_OP_COND_FAIL, as a result of the CHOICE - but this is wrong on lines 4 and 15 because both of these should be skippable (one and only one of the four can be picked) and the one on line 15 should also be conditional so that it is ignored if anything before it matches. After the patch, it looks like: // Bar // Seq1 [ 4] = ASN1_OP_MATCH_JUMP_OR_SKIP, // x1 [ 5] = _tag(UNIV, CONS, SEQ), ... [ 7] = ASN1_OP_COND_MATCH_OR_SKIP, // x2 [ 8] = _tagn(CONT, PRIM, 0), // Seq2 [ 9] = ASN1_OP_COND_MATCH_JUMP_OR_SKIP, // x3 [ 10] = _tag(UNIV, CONS, SEQ), ... [ 12] = ASN1_OP_COND_MATCH_JUMP_OR_SKIP, // x4 [ 13] = _tag(UNIV, CONS, SET), ... [ 15] = ASN1_OP_COND_FAIL, where all four options are skippable and the second, third and fourth are all conditional, as is the backstop at the end. This hasn't been a problem so far because in the ASN.1 specs we have are either using primitives or are using SET OF and SEQUENCE OF which are handled correctly. Whilst we're at it, also make sure that element labels get included in comments in the output for elements that have complex types. This cannot be tested with the code as it stands, but rather affects future code. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-By: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'scripts')
-rw-r--r--scripts/asn1_compiler.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/scripts/asn1_compiler.c b/scripts/asn1_compiler.c
index 7750e9c31483..e87359cd23c0 100644
--- a/scripts/asn1_compiler.c
+++ b/scripts/asn1_compiler.c
@@ -666,7 +666,7 @@ struct element {
unsigned flags;
#define ELEMENT_IMPLICIT 0x0001
#define ELEMENT_EXPLICIT 0x0002
-#define ELEMENT_MARKED 0x0004
+#define ELEMENT_TAG_SPECIFIED 0x0004
#define ELEMENT_RENDERED 0x0008
#define ELEMENT_SKIPPABLE 0x0010
#define ELEMENT_CONDITIONAL 0x0020
@@ -879,6 +879,7 @@ static struct element *parse_type(struct token **_cursor, struct token *end,
element->tag &= ~0x1f;
element->tag |= strtoul(cursor->value, &p, 10);
+ element->flags |= ELEMENT_TAG_SPECIFIED;
if (p - cursor->value != cursor->size)
abort();
cursor++;
@@ -1376,7 +1377,7 @@ static void render_out_of_line_list(FILE *out)
*/
static void render_element(FILE *out, struct element *e, struct element *tag)
{
- struct element *ec;
+ struct element *ec, *x;
const char *cond, *act;
int entry, skippable = 0, outofline = 0;
@@ -1435,15 +1436,17 @@ static void render_element(FILE *out, struct element *e, struct element *tag)
break;
}
- if (e->name)
+ x = tag ?: e;
+ if (x->name)
render_more(out, "\t\t// %*.*s",
- (int)e->name->size, (int)e->name->size,
- e->name->value);
+ (int)x->name->size, (int)x->name->size,
+ x->name->value);
render_more(out, "\n");
/* Render the tag */
- if (!tag)
+ if (!tag || !(tag->flags & ELEMENT_TAG_SPECIFIED))
tag = e;
+
if (tag->class == ASN1_UNIV &&
tag->tag != 14 &&
tag->tag != 15 &&
@@ -1539,7 +1542,7 @@ dont_render_tag:
case CHOICE:
for (ec = e->children; ec; ec = ec->next)
- render_element(out, ec, NULL);
+ render_element(out, ec, ec);
if (!skippable)
render_opcode(out, "ASN1_OP_COND_FAIL,\n");
if (e->action)