/*
 * Copyright (c) 1997 - 2006 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "gen_locl.h"
#include "lex.h"

RCSID("$Id$");

static void
decode_primitive (const char *typename, const char *name, const char *forwstr)
{
#if 0
    fprintf (codefile,
             "e = decode_%s(p, len, %s, &l);\n"
             "%s;\n",
             typename,
             name,
             forwstr);
#else
    fprintf (codefile,
             "e = der_get_%s(p, len, %s, &l);\n"
             "if(e) %s;\np += l; len -= l; ret += l;\n",
             typename,
             name,
             forwstr);
#endif
}

static void
find_tag (const Type *t,
          Der_class *cl, Der_type *ty, unsigned *tag)
{
    switch (t->type) {
    case TBitString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_BitString;
        break;
    case TBoolean:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_Boolean;
        break;
    case TChoice:
        errx(1, "Cannot have recursive CHOICE");
    case TEnumerated:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_Enumerated;
        break;
    case TGeneralString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_GeneralString;
        break;
    case TTeletexString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_TeletexString;
        break;
    case TGeneralizedTime:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_GeneralizedTime;
        break;
    case TIA5String:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_IA5String;
        break;
    case TInteger:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_Integer;
        break;
    case TNull:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_Null;
        break;
    case TOID:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_OID;
        break;
    case TOctetString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_OctetString;
        break;
    case TPrintableString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_PrintableString;
        break;
    case TSequence:
    case TSequenceOf:
        *cl  = ASN1_C_UNIV;
        *ty  = CONS;
        *tag = UT_Sequence;
        break;
    case TSet:
    case TSetOf:
        *cl  = ASN1_C_UNIV;
        *ty  = CONS;
        *tag = UT_Set;
        break;
    case TTag:
        *cl  = t->tag.tagclass;
        *ty  = is_primitive_type(t->subtype->type) ? PRIM : CONS;
        *tag = t->tag.tagvalue;
        break;
    case TType:
        if ((t->symbol->stype == Stype && t->symbol->type == NULL)
            || t->symbol->stype == SUndefined) {
            lex_error_message("%s is imported or still undefined, "
                              " can't generate tag checking data in CHOICE "
                              "without this information",
                              t->symbol->name);
            exit(1);
        }
        find_tag(t->symbol->type, cl, ty, tag);
        return;
    case TUTCTime:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_UTCTime;
        break;
    case TUTF8String:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_UTF8String;
        break;
    case TBMPString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_BMPString;
        break;
    case TUniversalString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_UniversalString;
        break;
    case TVisibleString:
        *cl  = ASN1_C_UNIV;
        *ty  = PRIM;
        *tag = UT_VisibleString;
        break;
    default:
        abort();
    }
}

static void
range_check(const char *name,
            const char *length,
            const char *forwstr,
            struct range *r)
{
    if (r->min == r->max + 2 || r->min < r->max)
        fprintf (codefile,
                 "if ((%s)->%s > %" PRId64 ") {\n"
                 "e = ASN1_MAX_CONSTRAINT; %s;\n"
                 "}\n",
                 name, length, r->max, forwstr);
    if (r->min - 1 == r->max || r->min < r->max)
        fprintf (codefile,
                 "if ((%s)->%s < %" PRId64 ") {\n"
                 "e = ASN1_MIN_CONSTRAINT; %s;\n"
                 "}\n",
                 name, length, r->min, forwstr);
    if (r->max == r->min)
        fprintf (codefile,
                 "if ((%s)->%s != %" PRId64 ") {\n"
                 "e = ASN1_EXACT_CONSTRAINT; %s;\n"
                 "}\n",
                 name, length, r->min, forwstr);
}

static int
decode_type (const char *name, const Type *t, int optional,
             const char *forwstr, const char *tmpstr, const char *dertype,
             unsigned int depth)
{
    switch (t->type) {
    case TType: {
        if (optional)
            fprintf(codefile,
                    "%s = calloc(1, sizeof(*%s));\n"
                    "if (%s == NULL) %s;\n",
                    name, name, name, forwstr);
        fprintf (codefile,
                 "e = decode_%s(p, len, %s, &l);\n",
                 t->symbol->gen_name, name);
        if (optional) {
            fprintf (codefile,
                     "if(e) {\n"
                     "free(%s);\n"
                     "%s = NULL;\n"
                     "} else {\n"
                     "p += l; len -= l; ret += l;\n"
                     "}\n",
                     name, name);
        } else {
            fprintf (codefile,
                     "if(e) %s;\n",
                     forwstr);
            fprintf (codefile,
                     "p += l; len -= l; ret += l;\n");
        }
        break;
    }
    case TInteger:
        if(t->members) {
            fprintf(codefile,
                    "{\n"
                    "int enumint;\n");
            decode_primitive ("integer", "&enumint", forwstr);
            fprintf(codefile,
                    "*%s = enumint;\n"
                    "}\n",
                    name);
        } else if (t->range == NULL) {
            decode_primitive ("heim_integer", name, forwstr);
        } else if (t->range->min < INT_MIN && t->range->max <= INT64_MAX) {
            decode_primitive ("integer64", name, forwstr);
        } else if (t->range->min >= 0 && t->range->max > UINT_MAX) {
            decode_primitive ("unsigned64", name, forwstr);
        } else if (t->range->min >= INT_MIN && t->range->max <= INT_MAX) {
            decode_primitive ("integer", name, forwstr);
        } else if (t->range->min >= 0 && t->range->max <= UINT_MAX) {
            decode_primitive ("unsigned", name, forwstr);
        } else
            errx(1, "%s: unsupported range %" PRId64 " -> %" PRId64,
                 name, t->range->min, t->range->max);
        break;
    case TBoolean:
      decode_primitive ("boolean", name, forwstr);
      break;
    case TEnumerated:
        decode_primitive ("enumerated", name, forwstr);
        break;
    case TOctetString:
        if (dertype) {
            fprintf(codefile,
                    "if (%s == CONS) {\n",
                    dertype);
            decode_primitive("octet_string_ber", name, forwstr);
            fprintf(codefile,
                    "} else {\n");
        }
        decode_primitive ("octet_string", name, forwstr);
        if (dertype)
            fprintf(codefile, "}\n");
        if (t->range)
            range_check(name, "length", forwstr, t->range);
        break;
    case TBitString: {
        Member *m;
        int pos = 0;

        if (ASN1_TAILQ_EMPTY(t->members)) {
            decode_primitive ("bit_string", name, forwstr);
            break;
        }
        fprintf(codefile,
                "if (len < 1) return ASN1_OVERRUN;\n"
                "p++; len--; ret++;\n");
        fprintf(codefile,
                "do {\n"
                "if (len < 1) break;\n");
        ASN1_TAILQ_FOREACH(m, t->members, members) {
            while (m->val / 8 > pos / 8) {
                fprintf (codefile,
                         "p++; len--; ret++;\n"
                         "if (len < 1) break;\n");
                pos += 8;
            }
            fprintf (codefile,
                     "(%s)->%s = (*p >> %d) & 1;\n",
                     name, m->gen_name, 7 - m->val % 8);
        }
        fprintf(codefile,
                "} while(0);\n");
        fprintf (codefile,
                 "p += len; ret += len;\n");
        break;
    }
    case TSequence: {
        Member *m;

        if (t->members == NULL)
            break;

        ASN1_TAILQ_FOREACH(m, t->members, members) {
            char *s = NULL;

            if (m->ellipsis)
                continue;

            if (asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&",
                          name, m->gen_name) < 0 || s == NULL)
                errx(1, "malloc");
            decode_type (s, m->type, m->optional, forwstr, m->gen_name, NULL,
                depth + 1);
            free (s);
        }

        break;
    }
    case TSet: {
        Member *m;
        unsigned int memno;

        if(t->members == NULL)
            break;

        fprintf(codefile, "{\n");
        fprintf(codefile, "unsigned int members = 0;\n");
        fprintf(codefile, "while(len > 0) {\n");
        fprintf(codefile,
                "Der_class class;\n"
                "Der_type type;\n"
                "int tag;\n"
                "e = der_get_tag (p, len, &class, &type, &tag, NULL);\n"
                "if(e) %s;\n", forwstr);
        fprintf(codefile, "switch (MAKE_TAG(class, type, tag)) {\n");
        memno = 0;
        ASN1_TAILQ_FOREACH(m, t->members, members) {
            char *s;

            assert(m->type->type == TTag);

            fprintf(codefile, "case MAKE_TAG(%s, %s, %s):\n",
                    classname(m->type->tag.tagclass),
                    is_primitive_type(m->type->subtype->type) ? "PRIM" : "CONS",
                    valuename(m->type->tag.tagclass, m->type->tag.tagvalue));

            if (asprintf (&s, "%s(%s)->%s", m->optional ? "" : "&", name, m->gen_name) < 0 || s == NULL)
                errx(1, "malloc");
            if(m->optional)
                fprintf(codefile,
                        "%s = calloc(1, sizeof(*%s));\n"
                        "if (%s == NULL) { e = ENOMEM; %s; }\n",
                        s, s, s, forwstr);
            decode_type (s, m->type, 0, forwstr, m->gen_name, NULL, depth + 1);
            free (s);

            fprintf(codefile, "members |= (1 << %d);\n", memno);
            memno++;
            fprintf(codefile, "break;\n");
        }
        fprintf(codefile,
                "default:\n"
                "return ASN1_MISPLACED_FIELD;\n"
                "break;\n");
        fprintf(codefile, "}\n");
        fprintf(codefile, "}\n");
        memno = 0;
        ASN1_TAILQ_FOREACH(m, t->members, members) {
            char *s;

            if (asprintf (&s, "%s->%s", name, m->gen_name) < 0 || s == NULL)
                errx(1, "malloc");
            fprintf(codefile, "if((members & (1 << %d)) == 0)\n", memno);
            if(m->optional)
                fprintf(codefile, "%s = NULL;\n", s);
            else if(m->defval)
                gen_assign_defval(s, m->defval);
            else
                fprintf(codefile, "return ASN1_MISSING_FIELD;\n");
            free(s);
            memno++;
        }
        fprintf(codefile, "}\n");
        break;
    }
    case TSetOf:
    case TSequenceOf: {
        char *n = NULL;
        char *sname = NULL;

        fprintf (codefile,
                 "{\n"
                 "size_t %s_origlen = len;\n"
                 "size_t %s_oldret = ret;\n"
                 "size_t %s_olen = 0;\n"
                 "void *%s_tmp;\n"
                 "ret = 0;\n"
                 "(%s)->len = 0;\n"
                 "(%s)->val = NULL;\n",
                 tmpstr,
                 tmpstr,
                 tmpstr,
                 tmpstr,
                 name,
                 name);

        fprintf (codefile,
                 "while(ret < %s_origlen) {\n"
                 "size_t %s_nlen = %s_olen + sizeof(*((%s)->val));\n"
                 "if (%s_olen > %s_nlen) { e = ASN1_OVERFLOW; %s; }\n"
                 "%s_olen = %s_nlen;\n"
                 "%s_tmp = realloc((%s)->val, %s_olen);\n"
                 "if (%s_tmp == NULL) { e = ENOMEM; %s; }\n"
                 "(%s)->val = %s_tmp;\n",
                 tmpstr,
                 tmpstr, tmpstr, name,
                 tmpstr, tmpstr, forwstr,
                 tmpstr, tmpstr,
                 tmpstr, name, tmpstr,
                 tmpstr, forwstr,
                 name, tmpstr);

        if (asprintf (&n, "&(%s)->val[(%s)->len]", name, name) < 0 || n == NULL)
            errx(1, "malloc");
        if (asprintf (&sname, "%s_s_of", tmpstr) < 0 || sname == NULL)
            errx(1, "malloc");
        decode_type (n, t->subtype, 0, forwstr, sname, NULL, depth + 1);
        fprintf (codefile,
                 "(%s)->len++;\n"
                 "len = %s_origlen - ret;\n"
                 "}\n"
                 "ret += %s_oldret;\n"
                 "}\n",
                 name,
                 tmpstr, tmpstr);
        if (t->range)
            range_check(name, "len", forwstr, t->range);
        free (n);
        free (sname);
        break;
    }
    case TGeneralizedTime:
        decode_primitive ("generalized_time", name, forwstr);
        break;
    case TGeneralString:
        decode_primitive ("general_string", name, forwstr);
        break;
    case TTeletexString:
        decode_primitive ("general_string", name, forwstr);
        break;
    case TTag:{
        char *tname = NULL, *typestring = NULL;
        char *ide = NULL;

        if (asprintf(&typestring, "%s_type", tmpstr) < 0 || typestring == NULL)
            errx(1, "malloc");

        fprintf(codefile,
                "{\n"
                "size_t %s_datalen, %s_oldlen;\n"
                "Der_type %s;\n",
                tmpstr, tmpstr, typestring);
        if(support_ber)
            fprintf(codefile,
                    "int is_indefinite%u;\n", depth);

        fprintf(codefile, "e = der_match_tag_and_length(p, len, %s, &%s, %s, "
                "&%s_datalen, &l);\n",
                classname(t->tag.tagclass),
                typestring,
                valuename(t->tag.tagclass, t->tag.tagvalue),
                tmpstr);

        /* XXX hardcode for now */
        if (support_ber && t->subtype->type == TOctetString) {
            ide = typestring;
        } else {
            fprintf(codefile,
                    "if (e == 0 && %s != %s) { e = ASN1_BAD_ID; }\n",
                    typestring,
                    is_primitive_type(t->subtype->type) ? "PRIM" : "CONS");
        }

        if(optional) {
            fprintf(codefile,
                    "if(e) {\n"
                    "%s = NULL;\n"
                    "} else {\n"
                     "%s = calloc(1, sizeof(*%s));\n"
                     "if (%s == NULL) { e = ENOMEM; %s; }\n",
                     name, name, name, name, forwstr);
        } else {
            fprintf(codefile, "if(e) %s;\n", forwstr);
        }
        fprintf (codefile,
                 "p += l; len -= l; ret += l;\n"
                 "%s_oldlen = len;\n",
                 tmpstr);
        if(support_ber)
            fprintf (codefile,
                     "if((is_indefinite%u = _heim_fix_dce(%s_datalen, &len)) < 0)\n"
                     "{ e = ASN1_BAD_FORMAT; %s; }\n"
                     "if (is_indefinite%u) { if (len < 2) { e = ASN1_OVERRUN; %s; } len -= 2; }",
                     depth, tmpstr, forwstr, depth, forwstr);
        else
            fprintf(codefile,
                    "if (%s_datalen > len) { e = ASN1_OVERRUN; %s; }\n"
                    "len = %s_datalen;\n", tmpstr, forwstr, tmpstr);
        if (asprintf (&tname, "%s_Tag", tmpstr) < 0 || tname == NULL)
            errx(1, "malloc");
        decode_type (name, t->subtype, 0, forwstr, tname, ide, depth + 1);
        if(support_ber)
            fprintf(codefile,
                    "if(is_indefinite%u){\n"
                    "len += 2;\n"
                    "e = der_match_tag_and_length(p, len, "
                    "(Der_class)0, &%s, UT_EndOfContent, "
                    "&%s_datalen, &l);\n"
                    "if(e) %s;\n"
                    "p += l; len -= l; ret += l;\n"
                    "if (%s != (Der_type)0) { e = ASN1_BAD_ID; %s; }\n"
                    "} else \n",
                    depth,
                    typestring,
                    tmpstr,
                    forwstr,
                    typestring, forwstr);
        fprintf(codefile,
                "len = %s_oldlen - %s_datalen;\n",
                tmpstr, tmpstr);
        if(optional)
            fprintf(codefile,
                    "}\n");
        fprintf(codefile,
                "}\n");
        free(tname);
        free(typestring);
        break;
    }
    case TChoice: {
        Member *m, *have_ellipsis = NULL;
        const char *els = "";

        if (t->members == NULL)
            break;

        ASN1_TAILQ_FOREACH(m, t->members, members) {
            const Type *tt = m->type;
            char *s = NULL;
            Der_class cl;
            Der_type  ty;
            unsigned  tag;

            if (m->ellipsis) {
                have_ellipsis = m;
                continue;
            }

            find_tag(tt, &cl, &ty, &tag);

            fprintf(codefile,
                    "%sif (der_match_tag(p, len, %s, %s, %s, NULL) == 0) {\n",
                    els,
                    classname(cl),
                    ty ? "CONS" : "PRIM",
                    valuename(cl, tag));
            fprintf(codefile,
                    "(%s)->element = %s;\n",
                    name, m->label);
            if (asprintf (&s, "%s(%s)->u.%s", m->optional ? "" : "&",
                          name, m->gen_name) < 0 || s == NULL)
                errx(1, "malloc");
            decode_type (s, m->type, m->optional, forwstr, m->gen_name, NULL,
                depth + 1);
            free(s);
            fprintf(codefile,
                    "}\n");
            els = "else ";
        }
        if (have_ellipsis) {
            fprintf(codefile,
                    "else {\n"
                    "(%s)->element = %s;\n"
                    "(%s)->u.%s.data = calloc(1, len);\n"
                    "if ((%s)->u.%s.data == NULL) {\n"
                    "e = ENOMEM; %s;\n"
                    "}\n"
                    "(%s)->u.%s.length = len;\n"
                    "memcpy((%s)->u.%s.data, p, len);\n"
                    "p += len;\n"
                    "ret += len;\n"
                    "len = 0;\n"
                    "}\n",
                    name, have_ellipsis->label,
                    name, have_ellipsis->gen_name,
                    name, have_ellipsis->gen_name,
                    forwstr,
                    name, have_ellipsis->gen_name,
                    name, have_ellipsis->gen_name);
        } else {
            fprintf(codefile,
                    "else {\n"
                    "e = ASN1_PARSE_ERROR;\n"
                    "%s;\n"
                    "}\n",
                    forwstr);
        }
        break;
    }
    case TUTCTime:
        decode_primitive ("utctime", name, forwstr);
        break;
    case TUTF8String:
        decode_primitive ("utf8string", name, forwstr);
        break;
    case TPrintableString:
        decode_primitive ("printable_string", name, forwstr);
        break;
    case TIA5String:
        decode_primitive ("ia5_string", name, forwstr);
        break;
    case TBMPString:
        decode_primitive ("bmp_string", name, forwstr);
        break;
    case TUniversalString:
        decode_primitive ("universal_string", name, forwstr);
        break;
    case TVisibleString:
        decode_primitive ("visible_string", name, forwstr);
        break;
    case TNull:
        fprintf (codefile, "/* NULL */\n");
        break;
    case TOID:
        decode_primitive ("oid", name, forwstr);
        break;
    default :
        abort ();
    }
    return 0;
}

void
generate_type_decode (const Symbol *s)
{
    int preserve = preserve_type(s->name) ? TRUE : FALSE;

    fprintf (codefile, "int ASN1CALL\n"
             "decode_%s(const unsigned char *p HEIMDAL_UNUSED_ATTRIBUTE,"
             " size_t len HEIMDAL_UNUSED_ATTRIBUTE, %s *data, size_t *size)\n"
             "{\n",
             s->gen_name, s->gen_name);

    switch (s->type->type) {
    case TInteger:
    case TBoolean:
    case TOctetString:
    case TOID:
    case TGeneralizedTime:
    case TGeneralString:
    case TTeletexString:
    case TUTF8String:
    case TPrintableString:
    case TIA5String:
    case TBMPString:
    case TUniversalString:
    case TVisibleString:
    case TUTCTime:
    case TNull:
    case TEnumerated:
    case TBitString:
    case TSequence:
    case TSequenceOf:
    case TSet:
    case TSetOf:
    case TTag:
    case TType:
    case TChoice:
        fprintf (codefile,
                 "size_t ret = 0;\n"
                 "size_t l HEIMDAL_UNUSED_ATTRIBUTE;\n"
                 "int e HEIMDAL_UNUSED_ATTRIBUTE;\n");
        if (preserve)
            fprintf (codefile, "const unsigned char *begin = p;\n");

        fprintf (codefile, "\n");
        fprintf (codefile, "memset(data, 0, sizeof(*data));\n"); /* hack to avoid `unused variable' */

        decode_type ("data", s->type, 0, "goto fail", "Top", NULL, 1);
        if (preserve)
            fprintf (codefile,
                     "data->_save.data = calloc(1, ret);\n"
                     "if (data->_save.data == NULL) { \n"
                     "e = ENOMEM; goto fail; \n"
                     "}\n"
                     "data->_save.length = ret;\n"
                     "memcpy(data->_save.data, begin, ret);\n");
        fprintf (codefile,
                 "if(size) *size = ret;\n"
                 "return 0;\n");
        fprintf (codefile,
                 "fail:\n"
                 "free_%s(data);\n"
                 "return e;\n",
                 s->gen_name);
        break;
    default:
        abort ();
    }
    fprintf (codefile, "}\n\n");
}