linux/scripts/asn1_compiler.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/* Simplified ASN.1 notation parser
*
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <linux/asn1_ber_bytecode.h>
enum token_type {
DIRECTIVE_ABSENT,
DIRECTIVE_ALL,
DIRECTIVE_ANY,
DIRECTIVE_APPLICATION,
DIRECTIVE_AUTOMATIC,
DIRECTIVE_BEGIN,
DIRECTIVE_BIT,
DIRECTIVE_BMPString,
DIRECTIVE_BOOLEAN,
DIRECTIVE_BY,
DIRECTIVE_CHARACTER,
DIRECTIVE_CHOICE,
DIRECTIVE_CLASS,
DIRECTIVE_COMPONENT,
DIRECTIVE_COMPONENTS,
DIRECTIVE_CONSTRAINED,
DIRECTIVE_CONTAINING,
DIRECTIVE_DEFAULT,
DIRECTIVE_DEFINED,
DIRECTIVE_DEFINITIONS,
DIRECTIVE_EMBEDDED,
DIRECTIVE_ENCODED,
DIRECTIVE_ENCODING_CONTROL,
DIRECTIVE_END,
DIRECTIVE_ENUMERATED,
DIRECTIVE_EXCEPT,
DIRECTIVE_EXPLICIT,
DIRECTIVE_EXPORTS,
DIRECTIVE_EXTENSIBILITY,
DIRECTIVE_EXTERNAL,
DIRECTIVE_FALSE,
DIRECTIVE_FROM,
DIRECTIVE_GeneralString,
DIRECTIVE_GeneralizedTime,
DIRECTIVE_GraphicString,
DIRECTIVE_IA5String,
DIRECTIVE_IDENTIFIER,
DIRECTIVE_IMPLICIT,
DIRECTIVE_IMPLIED,
DIRECTIVE_IMPORTS,
DIRECTIVE_INCLUDES,
DIRECTIVE_INSTANCE,
DIRECTIVE_INSTRUCTIONS,
DIRECTIVE_INTEGER,
DIRECTIVE_INTERSECTION,
DIRECTIVE_ISO646String,
DIRECTIVE_MAX,
DIRECTIVE_MIN,
DIRECTIVE_MINUS_INFINITY,
DIRECTIVE_NULL,
DIRECTIVE_NumericString,
DIRECTIVE_OBJECT,
DIRECTIVE_OCTET,
DIRECTIVE_OF,
DIRECTIVE_OPTIONAL,
DIRECTIVE_ObjectDescriptor,
DIRECTIVE_PATTERN,
DIRECTIVE_PDV,
DIRECTIVE_PLUS_INFINITY,
DIRECTIVE_PRESENT,
DIRECTIVE_PRIVATE,
DIRECTIVE_PrintableString,
DIRECTIVE_REAL,
DIRECTIVE_RELATIVE_OID,
DIRECTIVE_SEQUENCE,
DIRECTIVE_SET,
DIRECTIVE_SIZE,
DIRECTIVE_STRING,
DIRECTIVE_SYNTAX,
DIRECTIVE_T61String,
DIRECTIVE_TAGS,
DIRECTIVE_TRUE,
DIRECTIVE_TeletexString,
DIRECTIVE_UNION,
DIRECTIVE_UNIQUE,
DIRECTIVE_UNIVERSAL,
DIRECTIVE_UTCTime,
DIRECTIVE_UTF8String,
DIRECTIVE_UniversalString,
DIRECTIVE_VideotexString,
DIRECTIVE_VisibleString,
DIRECTIVE_WITH,
NR__DIRECTIVES,
TOKEN_ASSIGNMENT = NR__DIRECTIVES,
TOKEN_OPEN_CURLY,
TOKEN_CLOSE_CURLY,
TOKEN_OPEN_SQUARE,
TOKEN_CLOSE_SQUARE,
TOKEN_OPEN_ACTION,
TOKEN_CLOSE_ACTION,
TOKEN_COMMA,
TOKEN_NUMBER,
TOKEN_TYPE_NAME,
TOKEN_ELEMENT_NAME,
NR__TOKENS
};
static const unsigned char token_to_tag[NR__TOKENS] = {
/* EOC goes first */
[DIRECTIVE_BOOLEAN] = ASN1_BOOL,
[DIRECTIVE_INTEGER] = ASN1_INT,
[DIRECTIVE_BIT] = ASN1_BTS,
[DIRECTIVE_OCTET] = ASN1_OTS,
[DIRECTIVE_NULL] = ASN1_NULL,
[DIRECTIVE_OBJECT] = ASN1_OID,
[DIRECTIVE_ObjectDescriptor] = ASN1_ODE,
[DIRECTIVE_EXTERNAL] = ASN1_EXT,
[DIRECTIVE_REAL] = ASN1_REAL,
[DIRECTIVE_ENUMERATED] = ASN1_ENUM,
[DIRECTIVE_EMBEDDED] = 0,
[DIRECTIVE_UTF8String] = ASN1_UTF8STR,
[DIRECTIVE_RELATIVE_OID] = ASN1_RELOID,
/* 14 */
/* 15 */
[DIRECTIVE_SEQUENCE] = ASN1_SEQ,
[DIRECTIVE_SET] = ASN1_SET,
[DIRECTIVE_NumericString] = ASN1_NUMSTR,
[DIRECTIVE_PrintableString] = ASN1_PRNSTR,
[DIRECTIVE_T61String] = ASN1_TEXSTR,
[DIRECTIVE_TeletexString] = ASN1_TEXSTR,
[DIRECTIVE_VideotexString] = ASN1_VIDSTR,
[DIRECTIVE_IA5String] = ASN1_IA5STR,
[DIRECTIVE_UTCTime] = ASN1_UNITIM,
[DIRECTIVE_GeneralizedTime] = ASN1_GENTIM,
[DIRECTIVE_GraphicString] = ASN1_GRASTR,
[DIRECTIVE_VisibleString] = ASN1_VISSTR,
[DIRECTIVE_GeneralString] = ASN1_GENSTR,
[DIRECTIVE_UniversalString] = ASN1_UNITIM,
[DIRECTIVE_CHARACTER] = ASN1_CHRSTR,
[DIRECTIVE_BMPString] = ASN1_BMPSTR,
};
static const char asn1_classes[4][5] = {
[ASN1_UNIV] = "UNIV",
[ASN1_APPL] = "APPL",
[ASN1_CONT] = "CONT",
[ASN1_PRIV] = "PRIV"
};
static const char asn1_methods[2][5] = {
[ASN1_UNIV] = "PRIM",
[ASN1_APPL] = "CONS"
};
static const char *const asn1_universal_tags[32] = {
"EOC",
"BOOL",
"INT",
"BTS",
"OTS",
"NULL",
"OID",
"ODE",
"EXT",
"REAL",
"ENUM",
"EPDV",
"UTF8STR",
"RELOID",
NULL, /* 14 */
NULL, /* 15 */
"SEQ",
"SET",
"NUMSTR",
"PRNSTR",
"TEXSTR",
"VIDSTR",
"IA5STR",
"UNITIM",
"GENTIM",
"GRASTR",
"VISSTR",
"GENSTR",
"UNISTR",
"CHRSTR",
"BMPSTR",
NULL /* 31 */
};
static const char *filename;
static const char *grammar_name;
static const char *outputname;
static const char *headername;
static const char *const directives[NR__DIRECTIVES] = {
#define _(X) [DIRECTIVE_##X] = #X
_(ABSENT),
_(ALL),
_(ANY),
_(APPLICATION),
_(AUTOMATIC),
_(BEGIN),
_(BIT),
_(BMPString),
_(BOOLEAN),
_(BY),
_(CHARACTER),
_(CHOICE),
_(CLASS),
_(COMPONENT),
_(COMPONENTS),
_(CONSTRAINED),
_(CONTAINING),
_(DEFAULT),
_(DEFINED),
_(DEFINITIONS),
_(EMBEDDED),
_(ENCODED),
[DIRECTIVE_ENCODING_CONTROL] = "ENCODING-CONTROL",
_(END),
_(ENUMERATED),
_(EXCEPT),
_(EXPLICIT),
_(EXPORTS),
_(EXTENSIBILITY),
_(EXTERNAL),
_(FALSE),
_(FROM),
_(GeneralString),
_(GeneralizedTime),
_(GraphicString),
_(IA5String),
_(IDENTIFIER),
_(IMPLICIT),
_(IMPLIED),
_(IMPORTS),
_(INCLUDES),
_(INSTANCE),
_(INSTRUCTIONS),
_(INTEGER),
_(INTERSECTION),
_(ISO646String),
_(MAX),
_(MIN),
[DIRECTIVE_MINUS_INFINITY] = "MINUS-INFINITY",
[DIRECTIVE_NULL] = "NULL",
_(NumericString),
_(OBJECT),
_(OCTET),
_(OF),
_(OPTIONAL),
_(ObjectDescriptor),
_(PATTERN),
_(PDV),
[DIRECTIVE_PLUS_INFINITY] = "PLUS-INFINITY",
_(PRESENT),
_(PRIVATE),
_(PrintableString),
_(REAL),
[DIRECTIVE_RELATIVE_OID] = "RELATIVE-OID",
_(SEQUENCE),
_(SET),
_(SIZE),
_(STRING),
_(SYNTAX),
_(T61String),
_(TAGS),
_(TRUE),
_(TeletexString),
_(UNION),
_(UNIQUE),
_(UNIVERSAL),
_(UTCTime),
_(UTF8String),
_(UniversalString),
_(VideotexString),
_(VisibleString),
_(WITH)
};
struct action {
struct action *next;
char *name;
unsigned char index;
};
static struct action *action_list;
static unsigned nr_actions;
struct token {
unsigned short line;
enum token_type token_type : 8;
unsigned char size;
struct action *action;
char *content;
struct type *type;
};
static struct token *token_list;
static unsigned nr_tokens;
static bool verbose_opt;
static bool debug_opt;
#define verbose(fmt, ...) do { if (verbose_opt) printf(fmt, ## __VA_ARGS__); } while (0)
#define debug(fmt, ...) do { if (debug_opt) printf(fmt, ## __VA_ARGS__); } while (0)
static int directive_compare(const void *_key, const void *_pdir)
{
const struct token *token = _key;
const char *const *pdir = _pdir, *dir = *pdir;
size_t dlen, clen;
int val;
dlen = strlen(dir);
clen = (dlen < token->size) ? dlen : token->size;
//debug("cmp(%s,%s) = ", token->content, dir);
val = memcmp(token->content, dir, clen);
if (val != 0) {
//debug("%d [cmp]\n", val);
return val;
}
if (dlen == token->size) {
//debug("0\n");
return 0;
}
//debug("%d\n", (int)dlen - (int)token->size);
return dlen - token->size; /* shorter -> negative */
}
/*
* Tokenise an ASN.1 grammar
*/
static void tokenise(char *buffer, char *end)
{
struct token *tokens;
char *line, *nl, *start, *p, *q;
unsigned tix, lineno;
/* Assume we're going to have half as many tokens as we have
* characters
*/
token_list = tokens = calloc((end - buffer) / 2, sizeof(struct token));
if (!tokens) {
perror(NULL);
exit(1);
}
tix = 0;
lineno = 0;
while (buffer < end) {
/* First of all, break out a line */
lineno++;
line = buffer;
nl = memchr(line, '\n', end - buffer);
if (!nl) {
buffer = nl = end;
} else {
buffer = nl + 1;
*nl = '\0';
}
/* Remove "--" comments */
p = line;
next_comment:
while ((p = memchr(p, '-', nl - p))) {
if (p[1] == '-') {
/* Found a comment; see if there's a terminator */
q = p + 2;
while ((q = memchr(q, '-', nl - q))) {
if (q[1] == '-') {
/* There is - excise the comment */
q += 2;
memmove(p, q, nl - q);
goto next_comment;
}
q++;
}
*p = '\0';
nl = p;
break;
} else {
p++;
}
}
p = line;
while (p < nl) {
/* Skip white space */
while (p < nl && isspace(*p))
*(p++) = 0;
if (p >= nl)
break;
tokens[tix].line = lineno;
start = p;
/* Handle string tokens */
if (isalpha(*p)) {
const char **dir;
/* Can be a directive, type name or element
* name. Find the end of the name.
*/
q = p + 1;
while (q < nl && (isalnum(*q) || *q == '-' || *q == '_'))
q++;
tokens[tix].size = q - p;
p = q;
tokens[tix].content = malloc(tokens[tix].size + 1);
if (!tokens[tix].content) {
perror(NULL);
exit(1);
}
memcpy(tokens[tix].content, start, tokens[tix].size);
tokens[tix].content[tokens[tix].size] = 0;
/* If it begins with a lowercase letter then
* it's an element name
*/
if (islower(tokens[tix].content[0])) {
tokens[tix++].token_type = TOKEN_ELEMENT_NAME;
continue;
}
/* Otherwise we need to search the directive
* table
*/
dir = bsearch(&tokens[tix], directives,
sizeof(directives) / sizeof(directives[1]),
sizeof(directives[1]),
directive_compare);
if (dir) {
tokens[tix++].token_type = dir - directives;
continue;
}
tokens[tix++].token_type = TOKEN_TYPE_NAME;
continue;
}
/* Handle numbers */
if (isdigit(*p)) {
/* Find the end of the number */
q = p + 1;
while (q < nl && (isdigit(*q)))
q++;
tokens[tix].size = q - p;
p = q;
tokens[tix].content = malloc(tokens[tix].size + 1);
if (!tokens[tix].content) {
perror(NULL);
exit(1);
}
memcpy(tokens[tix].content, start, tokens[tix].size);
tokens[tix].content[tokens[tix].size] = 0;
tokens[tix++].token_type = TOKEN_NUMBER;
continue;
}
if (nl - p >= 3) {
if (memcmp(p, "::=", 3) == 0) {
p += 3;
tokens[tix].size = 3;
tokens[tix].content = "::=";
tokens[tix++].token_type = TOKEN_ASSIGNMENT;
continue;
}
}
if (nl - p >= 2) {
if (memcmp(p, "({", 2) == 0) {
p += 2;
tokens[tix].size = 2;
tokens[tix].content = "({";
tokens[tix++].token_type = TOKEN_OPEN_ACTION;
continue;
}
if (memcmp(p, "})", 2) == 0) {
p += 2;
tokens[tix].size = 2;
tokens[tix].content = "})";
tokens[tix++].token_type = TOKEN_CLOSE_ACTION;
continue;
}
}
if (nl - p >= 1) {
tokens[tix].size = 1;
switch (*p) {
case '{':
p += 1;
tokens[tix].content = "{";
tokens[tix++].token_type = TOKEN_OPEN_CURLY;
continue;
case '}':
p += 1;
tokens[tix].content = "}";
tokens[tix++].token_type = TOKEN_CLOSE_CURLY;
continue;
case '[':
p += 1;
tokens[tix].content = "[";
tokens[tix++].token_type = TOKEN_OPEN_SQUARE;
continue;
case ']':
p += 1;
tokens[tix].content = "]";
tokens[tix++].token_type = TOKEN_CLOSE_SQUARE;
continue;
case ',':
p += 1;
tokens[tix].content = ",";
tokens[tix++].token_type = TOKEN_COMMA;
continue;
default:
break;
}
}
fprintf(stderr, "%s:%u: Unknown character in grammar: '%c'\n",
filename, lineno, *p);
exit(1);
}
}
nr_tokens = tix;
verbose("Extracted %u tokens\n", nr_tokens);
#if 0
{
int n;
for (n = 0; n < nr_tokens; n++)
debug("Token %3u: '%s'\n", n, token_list[n].content);
}
#endif
}
static void build_type_list(void);
static void parse(void);
static void dump_elements(void);
static void render(FILE *out, FILE *hdr);
/*
*
*/
int main(int argc, char **argv)
{
struct stat st;
ssize_t readlen;
FILE *out, *hdr;
char *buffer, *p;
char *kbuild_verbose;
int fd;
kbuild_verbose = getenv("KBUILD_VERBOSE");
if (kbuild_verbose)
verbose_opt = atoi(kbuild_verbose);
while (argc > 4) {
if (strcmp(argv[1], "-v") == 0)
verbose_opt = true;
else if (strcmp(argv[1], "-d") == 0)
debug_opt = true;
else
break;
memmove(&argv[1], &argv[2], (argc - 2) * sizeof(char *));
argc--;
}
if (argc != 4) {
fprintf(stderr, "Format: %s [-v] [-d] <grammar-file> <c-file> <hdr-file>\n",
argv[0]);
exit(2);
}
filename = argv[1];
outputname = argv[2];
headername = argv[3];
fd = open(filename, O_RDONLY);
if (fd < 0) {
perror(filename);
exit(1);
}
if (fstat(fd, &st) < 0) {
perror(filename);
exit(1);
}
if (!(buffer = malloc(st.st_size + 1))) {
perror(NULL);
exit(1);
}
if ((readlen = read(fd, buffer, st.st_size)) < 0) {
perror(filename);
exit(1);
}
if (close(fd) < 0) {
perror(filename);
exit(1);
}
if (readlen != st.st_size) {
fprintf(stderr, "%s: Short read\n", filename);
exit(1);
}
p = strrchr(argv[1], '/');
p = p ? p + 1 : argv[1];
grammar_name = strdup(p);
if (!p) {
perror(NULL);
exit(1);
}
p = strchr(grammar_name, '.');
if (p)
*p = '\0';
buffer[readlen] = 0;
tokenise(buffer, buffer + readlen);
build_type_list();
parse();
dump_elements();
out = fopen(outputname, "w");
if (!out) {
perror(outputname);
exit(1);
}
hdr = fopen(headername, "w");
if (!hdr) {
perror(headername);
exit(1);
}
render(out, hdr);
if (fclose(out) < 0) {
perror(outputname);
exit(1);
}
if (fclose(hdr) < 0) {
perror(headername);
exit(1);
}
return 0;
}
enum compound {
NOT_COMPOUND,
SET,
SET_OF,
SEQUENCE,
SEQUENCE_OF,
CHOICE,
ANY,
TYPE_REF,
TAG_OVERRIDE
};
struct element {
struct type *type_def;
struct token *name;
struct token *type;
struct action *action;
struct element *children;
struct element *next;
struct element *render_next;
struct element *list_next;
uint8_t n_elements;
enum compound compound : 8;
enum asn1_class class : 8;
enum asn1_method method : 8;
uint8_t tag;
unsigned entry_index;
unsigned flags;
#define ELEMENT_IMPLICIT 0x0001
#define ELEMENT_EXPLICIT 0x0002
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>
2015-08-05 11:54:45 +00:00
#define ELEMENT_TAG_SPECIFIED 0x0004
#define ELEMENT_RENDERED 0x0008
#define ELEMENT_SKIPPABLE 0x0010
#define ELEMENT_CONDITIONAL 0x0020
};
struct type {
struct token *name;
struct token *def;
struct element *element;
unsigned ref_count;
unsigned flags;
#define TYPE_STOP_MARKER 0x0001
#define TYPE_BEGIN 0x0002
};
static struct type *type_list;
static struct type **type_index;
static unsigned nr_types;
static int type_index_compare(const void *_a, const void *_b)
{
const struct type *const *a = _a, *const *b = _b;
if ((*a)->name->size != (*b)->name->size)
return (*a)->name->size - (*b)->name->size;
else
return memcmp((*a)->name->content, (*b)->name->content,
(*a)->name->size);
}
static int type_finder(const void *_key, const void *_ti)
{
const struct token *token = _key;
const struct type *const *ti = _ti;
const struct type *type = *ti;
if (token->size != type->name->size)
return token->size - type->name->size;
else
return memcmp(token->content, type->name->content,
token->size);
}
/*
* Build up a list of types and a sorted index to that list.
*/
static void build_type_list(void)
{
struct type *types;
unsigned nr, t, n;
nr = 0;
for (n = 0; n < nr_tokens - 1; n++)
if (token_list[n + 0].token_type == TOKEN_TYPE_NAME &&
token_list[n + 1].token_type == TOKEN_ASSIGNMENT)
nr++;
if (nr == 0) {
fprintf(stderr, "%s: No defined types\n", filename);
exit(1);
}
nr_types = nr;
types = type_list = calloc(nr + 1, sizeof(type_list[0]));
if (!type_list) {
perror(NULL);
exit(1);
}
type_index = calloc(nr, sizeof(type_index[0]));
if (!type_index) {
perror(NULL);
exit(1);
}
t = 0;
types[t].flags |= TYPE_BEGIN;
for (n = 0; n < nr_tokens - 1; n++) {
if (token_list[n + 0].token_type == TOKEN_TYPE_NAME &&
token_list[n + 1].token_type == TOKEN_ASSIGNMENT) {
types[t].name = &token_list[n];
type_index[t] = &types[t];
t++;
}
}
types[t].name = &token_list[n + 1];
types[t].flags |= TYPE_STOP_MARKER;
qsort(type_index, nr, sizeof(type_index[0]), type_index_compare);
verbose("Extracted %u types\n", nr_types);
#if 0
for (n = 0; n < nr_types; n++) {
struct type *type = type_index[n];
debug("- %*.*s\n", type->name->content);
}
#endif
}
static struct element *parse_type(struct token **_cursor, struct token *stop,
struct token *name);
/*
* Parse the token stream
*/
static void parse(void)
{
struct token *cursor;
struct type *type;
/* Parse one type definition statement at a time */
type = type_list;
do {
cursor = type->name;
if (cursor[0].token_type != TOKEN_TYPE_NAME ||
cursor[1].token_type != TOKEN_ASSIGNMENT)
abort();
cursor += 2;
type->element = parse_type(&cursor, type[1].name, NULL);
type->element->type_def = type;
if (cursor != type[1].name) {
fprintf(stderr, "%s:%d: Parse error at token '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
}
} while (type++, !(type->flags & TYPE_STOP_MARKER));
verbose("Extracted %u actions\n", nr_actions);
}
static struct element *element_list;
static struct element *alloc_elem(struct token *type)
{
struct element *e = calloc(1, sizeof(*e));
if (!e) {
perror(NULL);
exit(1);
}
e->list_next = element_list;
element_list = e;
return e;
}
static struct element *parse_compound(struct token **_cursor, struct token *end,
int alternates);
/*
* Parse one type definition statement
*/
static struct element *parse_type(struct token **_cursor, struct token *end,
struct token *name)
{
struct element *top, *element;
struct action *action, **ppaction;
struct token *cursor = *_cursor;
struct type **ref;
char *p;
int labelled = 0, implicit = 0;
top = element = alloc_elem(cursor);
element->class = ASN1_UNIV;
element->method = ASN1_PRIM;
element->tag = token_to_tag[cursor->token_type];
element->name = name;
/* Extract the tag value if one given */
if (cursor->token_type == TOKEN_OPEN_SQUARE) {
cursor++;
if (cursor >= end)
goto overrun_error;
switch (cursor->token_type) {
case DIRECTIVE_UNIVERSAL:
element->class = ASN1_UNIV;
cursor++;
break;
case DIRECTIVE_APPLICATION:
element->class = ASN1_APPL;
cursor++;
break;
case TOKEN_NUMBER:
element->class = ASN1_CONT;
break;
case DIRECTIVE_PRIVATE:
element->class = ASN1_PRIV;
cursor++;
break;
default:
fprintf(stderr, "%s:%d: Unrecognised tag class token '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
}
if (cursor >= end)
goto overrun_error;
if (cursor->token_type != TOKEN_NUMBER) {
fprintf(stderr, "%s:%d: Missing tag number '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
}
element->tag &= ~0x1f;
element->tag |= strtoul(cursor->content, &p, 10);
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>
2015-08-05 11:54:45 +00:00
element->flags |= ELEMENT_TAG_SPECIFIED;
if (p - cursor->content != cursor->size)
abort();
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type != TOKEN_CLOSE_SQUARE) {
fprintf(stderr, "%s:%d: Missing closing square bracket '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
}
cursor++;
if (cursor >= end)
goto overrun_error;
labelled = 1;
}
/* Handle implicit and explicit markers */
if (cursor->token_type == DIRECTIVE_IMPLICIT) {
element->flags |= ELEMENT_IMPLICIT;
implicit = 1;
cursor++;
if (cursor >= end)
goto overrun_error;
} else if (cursor->token_type == DIRECTIVE_EXPLICIT) {
element->flags |= ELEMENT_EXPLICIT;
cursor++;
if (cursor >= end)
goto overrun_error;
}
if (labelled) {
if (!implicit)
element->method |= ASN1_CONS;
element->compound = implicit ? TAG_OVERRIDE : SEQUENCE;
element->children = alloc_elem(cursor);
element = element->children;
element->class = ASN1_UNIV;
element->method = ASN1_PRIM;
element->tag = token_to_tag[cursor->token_type];
element->name = name;
}
/* Extract the type we're expecting here */
element->type = cursor;
switch (cursor->token_type) {
case DIRECTIVE_ANY:
element->compound = ANY;
cursor++;
break;
case DIRECTIVE_NULL:
case DIRECTIVE_BOOLEAN:
case DIRECTIVE_ENUMERATED:
case DIRECTIVE_INTEGER:
element->compound = NOT_COMPOUND;
cursor++;
break;
case DIRECTIVE_EXTERNAL:
element->method = ASN1_CONS;
case DIRECTIVE_BMPString:
case DIRECTIVE_GeneralString:
case DIRECTIVE_GraphicString:
case DIRECTIVE_IA5String:
case DIRECTIVE_ISO646String:
case DIRECTIVE_NumericString:
case DIRECTIVE_PrintableString:
case DIRECTIVE_T61String:
case DIRECTIVE_TeletexString:
case DIRECTIVE_UniversalString:
case DIRECTIVE_UTF8String:
case DIRECTIVE_VideotexString:
case DIRECTIVE_VisibleString:
case DIRECTIVE_ObjectDescriptor:
case DIRECTIVE_GeneralizedTime:
case DIRECTIVE_UTCTime:
element->compound = NOT_COMPOUND;
cursor++;
break;
case DIRECTIVE_BIT:
case DIRECTIVE_OCTET:
element->compound = NOT_COMPOUND;
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type != DIRECTIVE_STRING)
goto parse_error;
cursor++;
break;
case DIRECTIVE_OBJECT:
element->compound = NOT_COMPOUND;
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type != DIRECTIVE_IDENTIFIER)
goto parse_error;
cursor++;
break;
case TOKEN_TYPE_NAME:
element->compound = TYPE_REF;
ref = bsearch(cursor, type_index, nr_types, sizeof(type_index[0]),
type_finder);
if (!ref) {
fprintf(stderr, "%s:%d: Type '%s' undefined\n",
filename, cursor->line, cursor->content);
exit(1);
}
cursor->type = *ref;
(*ref)->ref_count++;
cursor++;
break;
case DIRECTIVE_CHOICE:
element->compound = CHOICE;
cursor++;
element->children = parse_compound(&cursor, end, 1);
break;
case DIRECTIVE_SEQUENCE:
element->compound = SEQUENCE;
element->method = ASN1_CONS;
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type == DIRECTIVE_OF) {
element->compound = SEQUENCE_OF;
cursor++;
if (cursor >= end)
goto overrun_error;
element->children = parse_type(&cursor, end, NULL);
} else {
element->children = parse_compound(&cursor, end, 0);
}
break;
case DIRECTIVE_SET:
element->compound = SET;
element->method = ASN1_CONS;
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type == DIRECTIVE_OF) {
element->compound = SET_OF;
cursor++;
if (cursor >= end)
goto parse_error;
element->children = parse_type(&cursor, end, NULL);
} else {
element->children = parse_compound(&cursor, end, 1);
}
break;
default:
fprintf(stderr, "%s:%d: Token '%s' does not introduce a type\n",
filename, cursor->line, cursor->content);
exit(1);
}
/* Handle elements that are optional */
if (cursor < end && (cursor->token_type == DIRECTIVE_OPTIONAL ||
cursor->token_type == DIRECTIVE_DEFAULT)
) {
cursor++;
top->flags |= ELEMENT_SKIPPABLE;
}
if (cursor < end && cursor->token_type == TOKEN_OPEN_ACTION) {
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type != TOKEN_ELEMENT_NAME) {
fprintf(stderr, "%s:%d: Token '%s' is not an action function name\n",
filename, cursor->line, cursor->content);
exit(1);
}
action = malloc(sizeof(struct action));
if (!action) {
perror(NULL);
exit(1);
}
action->index = 0;
action->name = cursor->content;
for (ppaction = &action_list;
*ppaction;
ppaction = &(*ppaction)->next
) {
int cmp = strcmp(action->name, (*ppaction)->name);
if (cmp == 0) {
free(action);
action = *ppaction;
goto found;
}
if (cmp < 0) {
action->next = *ppaction;
*ppaction = action;
nr_actions++;
goto found;
}
}
action->next = NULL;
*ppaction = action;
nr_actions++;
found:
element->action = action;
cursor->action = action;
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type != TOKEN_CLOSE_ACTION) {
fprintf(stderr, "%s:%d: Missing close action, got '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
}
cursor++;
}
*_cursor = cursor;
return top;
parse_error:
fprintf(stderr, "%s:%d: Unexpected token '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
overrun_error:
fprintf(stderr, "%s: Unexpectedly hit EOF\n", filename);
exit(1);
}
/*
* Parse a compound type list
*/
static struct element *parse_compound(struct token **_cursor, struct token *end,
int alternates)
{
struct element *children, **child_p = &children, *element;
struct token *cursor = *_cursor, *name;
if (cursor->token_type != TOKEN_OPEN_CURLY) {
fprintf(stderr, "%s:%d: Expected compound to start with brace not '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
}
cursor++;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type == TOKEN_OPEN_CURLY) {
fprintf(stderr, "%s:%d: Empty compound\n",
filename, cursor->line);
exit(1);
}
for (;;) {
name = NULL;
if (cursor->token_type == TOKEN_ELEMENT_NAME) {
name = cursor;
cursor++;
if (cursor >= end)
goto overrun_error;
}
element = parse_type(&cursor, end, name);
if (alternates)
element->flags |= ELEMENT_SKIPPABLE | ELEMENT_CONDITIONAL;
*child_p = element;
child_p = &element->next;
if (cursor >= end)
goto overrun_error;
if (cursor->token_type != TOKEN_COMMA)
break;
cursor++;
if (cursor >= end)
goto overrun_error;
}
children->flags &= ~ELEMENT_CONDITIONAL;
if (cursor->token_type != TOKEN_CLOSE_CURLY) {
fprintf(stderr, "%s:%d: Expected compound closure, got '%s'\n",
filename, cursor->line, cursor->content);
exit(1);
}
cursor++;
*_cursor = cursor;
return children;
overrun_error:
fprintf(stderr, "%s: Unexpectedly hit EOF\n", filename);
exit(1);
}
static void dump_element(const struct element *e, int level)
{
const struct element *c;
const struct type *t = e->type_def;
const char *name = e->name ? e->name->content : ".";
const char *tname = t && t->name ? t->name->content : ".";
char tag[32];
if (e->class == 0 && e->method == 0 && e->tag == 0)
strcpy(tag, "<...>");
else if (e->class == ASN1_UNIV)
sprintf(tag, "%s %s %s",
asn1_classes[e->class],
asn1_methods[e->method],
asn1_universal_tags[e->tag]);
else
sprintf(tag, "%s %s %u",
asn1_classes[e->class],
asn1_methods[e->method],
e->tag);
printf("%c%c%c%c%c %c %*s[*] \e[33m%s\e[m %s %s \e[35m%s\e[m\n",
e->flags & ELEMENT_IMPLICIT ? 'I' : '-',
e->flags & ELEMENT_EXPLICIT ? 'E' : '-',
e->flags & ELEMENT_TAG_SPECIFIED ? 'T' : '-',
e->flags & ELEMENT_SKIPPABLE ? 'S' : '-',
e->flags & ELEMENT_CONDITIONAL ? 'C' : '-',
"-tTqQcaro"[e->compound],
level, "",
tag,
tname,
name,
e->action ? e->action->name : "");
if (e->compound == TYPE_REF)
dump_element(e->type->type->element, level + 3);
else
for (c = e->children; c; c = c->next)
dump_element(c, level + 3);
}
static void dump_elements(void)
{
if (debug_opt)
dump_element(type_list[0].element, 0);
}
static void render_element(FILE *out, struct element *e, struct element *tag);
static void render_out_of_line_list(FILE *out);
static int nr_entries;
static int render_depth = 1;
static struct element *render_list, **render_list_p = &render_list;
__attribute__((format(printf, 2, 3)))
static void render_opcode(FILE *out, const char *fmt, ...)
{
va_list va;
if (out) {
fprintf(out, "\t[%4d] =%*s", nr_entries, render_depth, "");
va_start(va, fmt);
vfprintf(out, fmt, va);
va_end(va);
}
nr_entries++;
}
__attribute__((format(printf, 2, 3)))
static void render_more(FILE *out, const char *fmt, ...)
{
va_list va;
if (out) {
va_start(va, fmt);
vfprintf(out, fmt, va);
va_end(va);
}
}
/*
* Render the grammar into a state machine definition.
*/
static void render(FILE *out, FILE *hdr)
{
struct element *e;
struct action *action;
struct type *root;
int index;
fprintf(hdr, "/*\n");
fprintf(hdr, " * Automatically generated by asn1_compiler. Do not edit\n");
fprintf(hdr, " *\n");
fprintf(hdr, " * ASN.1 parser for %s\n", grammar_name);
fprintf(hdr, " */\n");
fprintf(hdr, "#include <linux/asn1_decoder.h>\n");
fprintf(hdr, "\n");
fprintf(hdr, "extern const struct asn1_decoder %s_decoder;\n", grammar_name);
if (ferror(hdr)) {
perror(headername);
exit(1);
}
fprintf(out, "/*\n");
fprintf(out, " * Automatically generated by asn1_compiler. Do not edit\n");
fprintf(out, " *\n");
fprintf(out, " * ASN.1 parser for %s\n", grammar_name);
fprintf(out, " */\n");
fprintf(out, "#include <linux/asn1_ber_bytecode.h>\n");
fprintf(out, "#include \"%s.asn1.h\"\n", grammar_name);
fprintf(out, "\n");
if (ferror(out)) {
perror(outputname);
exit(1);
}
/* Tabulate the action functions we might have to call */
fprintf(hdr, "\n");
index = 0;
for (action = action_list; action; action = action->next) {
action->index = index++;
fprintf(hdr,
"extern int %s(void *, size_t, unsigned char,"
" const void *, size_t);\n",
action->name);
}
fprintf(hdr, "\n");
fprintf(out, "enum %s_actions {\n", grammar_name);
for (action = action_list; action; action = action->next)
fprintf(out, "\tACT_%s = %u,\n",
action->name, action->index);
fprintf(out, "\tNR__%s_actions = %u\n", grammar_name, nr_actions);
fprintf(out, "};\n");
fprintf(out, "\n");
fprintf(out, "static const asn1_action_t %s_action_table[NR__%s_actions] = {\n",
grammar_name, grammar_name);
for (action = action_list; action; action = action->next)
fprintf(out, "\t[%4u] = %s,\n", action->index, action->name);
fprintf(out, "};\n");
if (ferror(out)) {
perror(outputname);
exit(1);
}
/* We do two passes - the first one calculates all the offsets */
verbose("Pass 1\n");
nr_entries = 0;
root = &type_list[0];
render_element(NULL, root->element, NULL);
render_opcode(NULL, "ASN1_OP_COMPLETE,\n");
render_out_of_line_list(NULL);
for (e = element_list; e; e = e->list_next)
e->flags &= ~ELEMENT_RENDERED;
/* And then we actually render */
verbose("Pass 2\n");
fprintf(out, "\n");
fprintf(out, "static const unsigned char %s_machine[] = {\n",
grammar_name);
nr_entries = 0;
root = &type_list[0];
render_element(out, root->element, NULL);
render_opcode(out, "ASN1_OP_COMPLETE,\n");
render_out_of_line_list(out);
fprintf(out, "};\n");
fprintf(out, "\n");
fprintf(out, "const struct asn1_decoder %s_decoder = {\n", grammar_name);
fprintf(out, "\t.machine = %s_machine,\n", grammar_name);
fprintf(out, "\t.machlen = sizeof(%s_machine),\n", grammar_name);
fprintf(out, "\t.actions = %s_action_table,\n", grammar_name);
fprintf(out, "};\n");
}
/*
* Render the out-of-line elements
*/
static void render_out_of_line_list(FILE *out)
{
struct element *e, *ce;
const char *act;
int entry;
while ((e = render_list)) {
render_list = e->render_next;
if (!render_list)
render_list_p = &render_list;
render_more(out, "\n");
e->entry_index = entry = nr_entries;
render_depth++;
for (ce = e->children; ce; ce = ce->next)
render_element(out, ce, NULL);
render_depth--;
act = e->action ? "_ACT" : "";
switch (e->compound) {
case SEQUENCE:
render_opcode(out, "ASN1_OP_END_SEQ%s,\n", act);
break;
case SEQUENCE_OF:
render_opcode(out, "ASN1_OP_END_SEQ_OF%s,\n", act);
render_opcode(out, "_jump_target(%u),\n", entry);
break;
case SET:
render_opcode(out, "ASN1_OP_END_SET%s,\n", act);
break;
case SET_OF:
render_opcode(out, "ASN1_OP_END_SET_OF%s,\n", act);
render_opcode(out, "_jump_target(%u),\n", entry);
break;
default:
break;
}
if (e->action)
render_opcode(out, "_action(ACT_%s),\n",
e->action->name);
render_opcode(out, "ASN1_OP_RETURN,\n");
}
}
/*
* Render an element.
*/
static void render_element(FILE *out, struct element *e, struct element *tag)
{
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>
2015-08-05 11:54:45 +00:00
struct element *ec, *x;
const char *cond, *act;
int entry, skippable = 0, outofline = 0;
if (e->flags & ELEMENT_SKIPPABLE ||
(tag && tag->flags & ELEMENT_SKIPPABLE))
skippable = 1;
if ((e->type_def && e->type_def->ref_count > 1) ||
skippable)
outofline = 1;
if (e->type_def && out) {
render_more(out, "\t// %s\n", e->type_def->name->content);
}
/* Render the operation */
cond = (e->flags & ELEMENT_CONDITIONAL ||
(tag && tag->flags & ELEMENT_CONDITIONAL)) ? "COND_" : "";
act = e->action ? "_ACT" : "";
switch (e->compound) {
case ANY:
render_opcode(out, "ASN1_OP_%sMATCH_ANY%s%s,",
cond, act, skippable ? "_OR_SKIP" : "");
if (e->name)
render_more(out, "\t\t// %s", e->name->content);
render_more(out, "\n");
goto dont_render_tag;
case TAG_OVERRIDE:
render_element(out, e->children, e);
return;
case SEQUENCE:
case SEQUENCE_OF:
case SET:
case SET_OF:
render_opcode(out, "ASN1_OP_%sMATCH%s%s,",
cond,
outofline ? "_JUMP" : "",
skippable ? "_OR_SKIP" : "");
break;
case CHOICE:
goto dont_render_tag;
case TYPE_REF:
if (e->class == ASN1_UNIV && e->method == ASN1_PRIM && e->tag == 0)
goto dont_render_tag;
default:
render_opcode(out, "ASN1_OP_%sMATCH%s%s,",
cond, act,
skippable ? "_OR_SKIP" : "");
break;
}
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>
2015-08-05 11:54:45 +00:00
x = tag ?: e;
if (x->name)
render_more(out, "\t\t// %s", x->name->content);
render_more(out, "\n");
/* Render the tag */
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>
2015-08-05 11:54:45 +00:00
if (!tag || !(tag->flags & ELEMENT_TAG_SPECIFIED))
tag = e;
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>
2015-08-05 11:54:45 +00:00
if (tag->class == ASN1_UNIV &&
tag->tag != 14 &&
tag->tag != 15 &&
tag->tag != 31)
render_opcode(out, "_tag(%s, %s, %s),\n",
asn1_classes[tag->class],
asn1_methods[tag->method | e->method],
asn1_universal_tags[tag->tag]);
else
render_opcode(out, "_tagn(%s, %s, %2u),\n",
asn1_classes[tag->class],
asn1_methods[tag->method | e->method],
tag->tag);
tag = NULL;
dont_render_tag:
/* Deal with compound types */
switch (e->compound) {
case TYPE_REF:
render_element(out, e->type->type->element, tag);
if (e->action)
ASN.1: Fix actions on CHOICE elements with IMPLICIT tags In an ASN.1 description where there is a CHOICE construct that contains elements with IMPLICIT tags that refer to constructed types, actions to be taken on those elements should be conditional on the corresponding element actually being matched. Currently, however, such actions are performed unconditionally in the middle of processing the CHOICE. For example, look at elements 'b' and 'e' here: A ::= SEQUENCE { CHOICE { b [0] IMPLICIT B ({ do_XXXXXXXXXXXX_b }), c [1] EXPLICIT C ({ do_XXXXXXXXXXXX_c }), d [2] EXPLICIT B ({ do_XXXXXXXXXXXX_d }), e [3] IMPLICIT C ({ do_XXXXXXXXXXXX_e }), f [4] IMPLICIT INTEGER ({ do_XXXXXXXXXXXX_f }) } } ({ do_XXXXXXXXXXXX_A }) B ::= SET OF OBJECT IDENTIFIER ({ do_XXXXXXXXXXXX_oid }) C ::= SET OF INTEGER ({ do_XXXXXXXXXXXX_int }) They each have an action (do_XXXXXXXXXXXX_b and do_XXXXXXXXXXXX_e) that should only be processed if that element is matched. The problem is that there's no easy place to hang the action off in the subclause (type B for element 'b' and type C for element 'e') because subclause opcode sequences can be shared. To fix this, introduce a conditional action opcode(ASN1_OP_MAYBE_ACT) that the decoder only processes if the preceding match was successful. This can be seen in an excerpt from the output of the fixed ASN.1 compiler for the above ASN.1 description: [ 13] = ASN1_OP_COND_MATCH_JUMP_OR_SKIP, // e [ 14] = _tagn(CONT, CONS, 3), [ 15] = _jump_target(45), // --> C [ 16] = ASN1_OP_MAYBE_ACT, [ 17] = _action(ACT_do_XXXXXXXXXXXX_e), In this, if the op at [13] is matched (ie. element 'e' above) then the action at [16] will be performed. However, if the op at [13] doesn't match or is skipped because it is conditional and some previous op matched, then the action at [16] will be ignored. Note that to make this work in the decoder, the ASN1_OP_RETURN op must set the flag to indicate that a match happened. This is necessary because the _jump_target() seen above introduces a subclause (in this case an object of type 'C') which is likely to alter the flag. Setting the flag here is okay because to process a subclause, a match must have happened and caused a jump. 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>
2015-08-05 11:54:46 +00:00
render_opcode(out, "ASN1_OP_%sACT,\n",
skippable ? "MAYBE_" : "");
break;
case SEQUENCE:
if (outofline) {
/* Render out-of-line for multiple use or
* skipability */
render_opcode(out, "_jump_target(%u),", e->entry_index);
if (e->type_def && e->type_def->name)
render_more(out, "\t\t// --> %s",
e->type_def->name->content);
render_more(out, "\n");
if (!(e->flags & ELEMENT_RENDERED)) {
e->flags |= ELEMENT_RENDERED;
*render_list_p = e;
render_list_p = &e->render_next;
}
return;
} else {
/* Render inline for single use */
render_depth++;
for (ec = e->children; ec; ec = ec->next)
render_element(out, ec, NULL);
render_depth--;
render_opcode(out, "ASN1_OP_END_SEQ%s,\n", act);
}
break;
case SEQUENCE_OF:
case SET_OF:
if (outofline) {
/* Render out-of-line for multiple use or
* skipability */
render_opcode(out, "_jump_target(%u),", e->entry_index);
if (e->type_def && e->type_def->name)
render_more(out, "\t\t// --> %s",
e->type_def->name->content);
render_more(out, "\n");
if (!(e->flags & ELEMENT_RENDERED)) {
e->flags |= ELEMENT_RENDERED;
*render_list_p = e;
render_list_p = &e->render_next;
}
return;
} else {
/* Render inline for single use */
entry = nr_entries;
render_depth++;
render_element(out, e->children, NULL);
render_depth--;
if (e->compound == SEQUENCE_OF)
render_opcode(out, "ASN1_OP_END_SEQ_OF%s,\n", act);
else
render_opcode(out, "ASN1_OP_END_SET_OF%s,\n", act);
render_opcode(out, "_jump_target(%u),\n", entry);
}
break;
case SET:
/* I can't think of a nice way to do SET support without having
* a stack of bitmasks to make sure no element is repeated.
* The bitmask has also to be checked that no non-optional
* elements are left out whilst not preventing optional
* elements from being left out.
*/
fprintf(stderr, "The ASN.1 SET type is not currently supported.\n");
exit(1);
case CHOICE:
for (ec = e->children; ec; ec = ec->next)
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>
2015-08-05 11:54:45 +00:00
render_element(out, ec, ec);
if (!skippable)
render_opcode(out, "ASN1_OP_COND_FAIL,\n");
if (e->action)
render_opcode(out, "ASN1_OP_ACT,\n");
break;
default:
break;
}
if (e->action)
render_opcode(out, "_action(ACT_%s),\n", e->action->name);
}