X-Git-Url: https://git.stg.codes/stg.git/blobdiff_plain/8c6fa3fbaccc22127280bf77a48fab5a3ee0716e..46b0747592074017ff0ea4b33d4a7194235886e5:/libs/smux/asn_codecs_prim.c diff --git a/libs/smux/asn_codecs_prim.c b/libs/smux/asn_codecs_prim.c new file mode 100644 index 00000000..4e5c6393 --- /dev/null +++ b/libs/smux/asn_codecs_prim.c @@ -0,0 +1,295 @@ +/*- + * Copyright (c) 2003, 2004 Lev Walkin . All rights reserved. + * Redistribution and modifications are permitted subject to BSD license. + */ +#include +#include +#include + +/* + * Decode an always-primitive type. + */ +asn_dec_rval_t +ber_decode_primitive(asn_codec_ctx_t *opt_codec_ctx, + asn_TYPE_descriptor_t *td, + void **sptr, const void *buf_ptr, size_t size, int tag_mode) { + ASN__PRIMITIVE_TYPE_t *st = (ASN__PRIMITIVE_TYPE_t *)*sptr; + asn_dec_rval_t rval; + ber_tlv_len_t length; + + /* + * If the structure is not there, allocate it. + */ + if(st == NULL) { + st = (ASN__PRIMITIVE_TYPE_t *)CALLOC(1, sizeof(*st)); + if(st == NULL) _ASN_DECODE_FAILED; + *sptr = (void *)st; + } + + ASN_DEBUG("Decoding %s as plain primitive (tm=%d)", + td->name, tag_mode); + + /* + * Check tags and extract value length. + */ + rval = ber_check_tags(opt_codec_ctx, td, 0, buf_ptr, size, + tag_mode, 0, &length, 0); + if(rval.code != RC_OK) + return rval; + + ASN_DEBUG("%s length is %d bytes", td->name, (int)length); + + /* + * Make sure we have this length. + */ + buf_ptr = ((const char *)buf_ptr) + rval.consumed; + size -= rval.consumed; + if(length > (ber_tlv_len_t)size) { + rval.code = RC_WMORE; + rval.consumed = 0; + return rval; + } + + st->size = (int)length; + /* The following better be optimized away. */ + if(sizeof(st->size) != sizeof(length) + && (ber_tlv_len_t)st->size != length) { + st->size = 0; + _ASN_DECODE_FAILED; + } + + st->buf = (uint8_t *)MALLOC(length + 1); + if(!st->buf) { + st->size = 0; + _ASN_DECODE_FAILED; + } + + memcpy(st->buf, buf_ptr, length); + st->buf[length] = '\0'; /* Just in case */ + + rval.code = RC_OK; + rval.consumed += length; + + ASN_DEBUG("Took %ld/%ld bytes to encode %s", + (long)rval.consumed, + (long)length, td->name); + + return rval; +} + +/* + * Encode an always-primitive type using DER. + */ +asn_enc_rval_t +der_encode_primitive(asn_TYPE_descriptor_t *td, void *sptr, + int tag_mode, ber_tlv_tag_t tag, + asn_app_consume_bytes_f *cb, void *app_key) { + asn_enc_rval_t erval; + ASN__PRIMITIVE_TYPE_t *st = (ASN__PRIMITIVE_TYPE_t *)sptr; + + ASN_DEBUG("%s %s as a primitive type (tm=%d)", + cb?"Encoding":"Estimating", td->name, tag_mode); + + erval.encoded = der_write_tags(td, st->size, tag_mode, 0, tag, + cb, app_key); + ASN_DEBUG("%s wrote tags %d", td->name, (int)erval.encoded); + if(erval.encoded == -1) { + erval.failed_type = td; + erval.structure_ptr = sptr; + return erval; + } + + if(cb && st->buf) { + if(cb(st->buf, st->size, app_key) < 0) { + erval.encoded = -1; + erval.failed_type = td; + erval.structure_ptr = sptr; + return erval; + } + } else { + assert(st->buf || st->size == 0); + } + + erval.encoded += st->size; + _ASN_ENCODED_OK(erval); +} + +void +ASN__PRIMITIVE_TYPE_free(asn_TYPE_descriptor_t *td, void *sptr, + int contents_only) { + ASN__PRIMITIVE_TYPE_t *st = (ASN__PRIMITIVE_TYPE_t *)sptr; + + if(!td || !sptr) + return; + + ASN_DEBUG("Freeing %s as a primitive type", td->name); + + if(st->buf) + FREEMEM(st->buf); + + if(!contents_only) + FREEMEM(st); +} + + +/* + * Local internal type passed around as an argument. + */ +struct xdp_arg_s { + asn_TYPE_descriptor_t *type_descriptor; + void *struct_key; + xer_primitive_body_decoder_f *prim_body_decoder; + int decoded_something; + int want_more; +}; + + +static int +xer_decode__unexpected_tag(void *key, const void *chunk_buf, size_t chunk_size) { + struct xdp_arg_s *arg = (struct xdp_arg_s *)key; + enum xer_pbd_rval bret; + + if(arg->decoded_something) { + if(xer_is_whitespace(chunk_buf, chunk_size)) + return 0; /* Skip it. */ + /* + * Decoding was done once already. Prohibit doing it again. + */ + return -1; + } + + bret = arg->prim_body_decoder(arg->type_descriptor, + arg->struct_key, chunk_buf, chunk_size); + switch(bret) { + case XPBD_SYSTEM_FAILURE: + case XPBD_DECODER_LIMIT: + case XPBD_BROKEN_ENCODING: + break; + case XPBD_BODY_CONSUMED: + /* Tag decoded successfully */ + arg->decoded_something = 1; + /* Fall through */ + case XPBD_NOT_BODY_IGNORE: /* Safe to proceed further */ + return 0; + } + + return -1; +} + +static ssize_t +xer_decode__body(void *key, const void *chunk_buf, size_t chunk_size, int have_more) { + struct xdp_arg_s *arg = (struct xdp_arg_s *)key; + enum xer_pbd_rval bret; + + if(arg->decoded_something) { + if(xer_is_whitespace(chunk_buf, chunk_size)) + return chunk_size; + /* + * Decoding was done once already. Prohibit doing it again. + */ + return -1; + } + + if(!have_more) { + /* + * If we've received something like "1", we can't really + * tell whether it is really `1` or `123`, until we know + * that there is no more data coming. + * The have_more argument will be set to 1 once something + * like this is available to the caller of this callback: + * "1want_more = 1; + return -1; + } + + bret = arg->prim_body_decoder(arg->type_descriptor, + arg->struct_key, chunk_buf, chunk_size); + switch(bret) { + case XPBD_SYSTEM_FAILURE: + case XPBD_DECODER_LIMIT: + case XPBD_BROKEN_ENCODING: + break; + case XPBD_BODY_CONSUMED: + /* Tag decoded successfully */ + arg->decoded_something = 1; + /* Fall through */ + case XPBD_NOT_BODY_IGNORE: /* Safe to proceed further */ + return chunk_size; + } + + return -1; +} + + +asn_dec_rval_t +xer_decode_primitive(asn_codec_ctx_t *opt_codec_ctx, + asn_TYPE_descriptor_t *td, + void **sptr, + size_t struct_size, + const char *opt_mname, + const void *buf_ptr, size_t size, + xer_primitive_body_decoder_f *prim_body_decoder +) { + const char *xml_tag = opt_mname ? opt_mname : td->xml_tag; + asn_struct_ctx_t s_ctx; + struct xdp_arg_s s_arg; + asn_dec_rval_t rc; + + /* + * Create the structure if does not exist. + */ + if(!*sptr) { + *sptr = CALLOC(1, struct_size); + if(!*sptr) _ASN_DECODE_FAILED; + } + + memset(&s_ctx, 0, sizeof(s_ctx)); + s_arg.type_descriptor = td; + s_arg.struct_key = *sptr; + s_arg.prim_body_decoder = prim_body_decoder; + s_arg.decoded_something = 0; + s_arg.want_more = 0; + + rc = xer_decode_general(opt_codec_ctx, &s_ctx, &s_arg, + xml_tag, buf_ptr, size, + xer_decode__unexpected_tag, xer_decode__body); + switch(rc.code) { + case RC_OK: + if(!s_arg.decoded_something) { + char ch; + ASN_DEBUG("Primitive body is not recognized, " + "supplying empty one"); + /* + * Decoding opportunity has come and gone. + * Where's the result? + * Try to feed with empty body, see if it eats it. + */ + if(prim_body_decoder(s_arg.type_descriptor, + s_arg.struct_key, &ch, 0) + != XPBD_BODY_CONSUMED) { + /* + * This decoder does not like empty stuff. + */ + _ASN_DECODE_FAILED; + } + } + break; + case RC_WMORE: + /* + * Redo the whole thing later. + * We don't have a context to save intermediate parsing state. + */ + rc.consumed = 0; + break; + case RC_FAIL: + rc.consumed = 0; + if(s_arg.want_more) + rc.code = RC_WMORE; + else + _ASN_DECODE_FAILED; + break; + } + return rc; +} +