/*
 * Generic converter template for a selected ASN.1 type.
 * Copyright (c) 2005-2017 Lev Walkin <vlm@lionet.info>.
 * All rights reserved.
 * 
 * To compile with your own ASN.1 type, redefine the PDU as shown:
 * 
 * cc -DPDU=MyCustomType -o myDecoder.o -c converter-example.c
 */
#ifdef    HAVE_CONFIG_H
#include <config.h>
#endif
#define __EXTENSIONS__
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>    /* for atoi(3) */
#include <getopt.h>    /* for getopt(3) */
#include <string.h>    /* for strerror(3) */
#include <sysexits.h>    /* for EX_* exit codes */
#include <errno.h>    /* for errno */
#include <unistd.h>    /* for isatty(3) */
#include "asn_application.h"
#include <asn_internal.h>    /* for ASN__DEFAULT_STACK_MAX */
#include <MessageFrame.h>

#define MAX_BUF_LEN 65000


/* Convert "Type" defined by -DPDU into "asn_DEF_Type" */
#ifdef PDU
#define    ASN_DEF_PDU(t)    asn_DEF_ ## t
#define    DEF_PDU_Type(t)    ASN_DEF_PDU(t)
#define    PDU_Type    DEF_PDU_Type(PDU)
extern asn_TYPE_descriptor_t PDU_Type;    /* ASN.1 type to be decoded */
#define PDU_Type_Ptr (&PDU_Type)
#else   /* !PDU */
#define PDU_Type_Ptr    NULL
#endif  /* PDU */

#ifdef ASN_PDU_COLLECTION /* Generated by asn1c -pdu=... */
extern asn_TYPE_descriptor_t *asn_pdu_collection[];
#endif

#ifndef NO_ASN_PDU
#if !defined(PDU) && !defined(ASN_PDU_COLLECTION)
#error Define -DPDU to compile this example converter.
#error `asn1c -pdu=...` adds necessary flags automatically.
#endif
#endif

/*
 * Open file and parse its contens.
 */
static void *data_decode_from_file(enum asn_transfer_syntax,
		asn_TYPE_descriptor_t *asnTypeOfPDU,
		FILE *file, const char *name,
		ssize_t suggested_bufsize, int first_pdu);
static int write_out(const void *buffer, size_t size, void *key);
static FILE *argument_to_file(char *av[], int idx);
static char *argument_to_name(char *av[], int idx);

int opt_debug;   /* -d (or -dd) */
static int opt_check;   /* -c (constraints checking) */
static int opt_stack;   /* -s (maximum stack size) */
static int opt_nopad;   /* -per-nopad (PER input is not padded between msgs) */
static int opt_onepdu;  /* -1 (decode single PDU) */

#ifdef    JUNKTEST        /* Enable -J <probability> */
#define JUNKOPT "J:"
static double opt_jprob;    /* Junk bit probability */
static int    junk_failures;
static void   junk_bytes_with_probability(uint8_t *, size_t, double prob);

#define RANDOPT "R:"
static ssize_t random_max_size = 0; /* Size of the random data */

#if !defined(__FreeBSD__) && !(defined(__APPLE__) && defined(__MACH__))
static void
srandomdev(void) {
	FILE *f = fopen("/dev/urandom", "rb");
	unsigned seed;
	if(f) {
		if(fread(&seed, 1, sizeof(seed), f) != sizeof(seed)) {
			seed = time(NULL);
		}
		fclose(f);
	} else {
		seed = time(NULL);
	}
	srandom(seed);
}
#endif

#else   /* !JUNKTEST */
#define    JUNKOPT
#define    RANDOPT
#endif  /* JUNKTEST */

/* Debug output function */
static void CC_PRINTFLIKE(1, 2)
DEBUG(const char *fmt, ...) {
	va_list ap;
	if(!opt_debug) return;
	fprintf(stderr, "AD: ");
	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	va_end(ap);
	fprintf(stderr, "\n");
}

static const char *
ats_simple_name(enum asn_transfer_syntax syntax) {
	switch(syntax) {
	case ATS_INVALID:
		return "/dev/null";
	case ATS_NONSTANDARD_PLAINTEXT:
		return "plaintext";
	case ATS_BER:
		return "BER";
	case ATS_DER:
		return "DER";
	case ATS_CER:
		return "CER";
	case ATS_BASIC_OER:
	case ATS_CANONICAL_OER:
		return "OER";
	case ATS_BASIC_XER:
	case ATS_CANONICAL_XER:
		return "XER";
	case ATS_UNALIGNED_BASIC_PER:
	case ATS_UNALIGNED_CANONICAL_PER:
		return "PER";
	default:
		return "<?>";
	}
}

#define CODEC_OFFSET(fname)  ((ptrdiff_t)&(((asn_TYPE_operation_t *)0)->fname))
typedef struct {
	const char *name;
	enum asn_transfer_syntax syntax;
	ptrdiff_t codec_offset;
	const char *full_name;
} syntax_selector;

static syntax_selector input_encodings[] = {
		{"ber", ATS_BER, CODEC_OFFSET(ber_decoder),
				"Input is in BER (Basic Encoding Rules) or DER"},
				{"oer", ATS_BASIC_OER, CODEC_OFFSET(oer_decoder),
						"Input is in OER (Octet Encoding Rules)"},
						{"per", ATS_UNALIGNED_BASIC_PER, CODEC_OFFSET(uper_decoder),
								"Input is in Unaligned PER (Packed Encoding Rules)"},
								{"xer", ATS_BASIC_XER, CODEC_OFFSET(xer_decoder),
										"Input is in XER (XML Encoding Rules)"},
										{0, ATS_INVALID, 0, 0}};

static syntax_selector output_encodings[] = {
		{"der", ATS_DER, CODEC_OFFSET(der_encoder),
				"Output as DER (Distinguished Encoding Rules)"},
				{"oer", ATS_CANONICAL_OER, CODEC_OFFSET(oer_encoder),
						"Output as Canonical OER (Octet Encoding Rules)"},
						{"per", ATS_UNALIGNED_CANONICAL_PER, CODEC_OFFSET(uper_encoder),
								"Output as Unaligned PER (Packed Encoding Rules)"},
								{"xer", ATS_BASIC_XER, CODEC_OFFSET(xer_encoder),
										"Output as XER (XML Encoding Rules)"},
										{"text", ATS_NONSTANDARD_PLAINTEXT, CODEC_OFFSET(print_struct),
												"Output as plain semi-structured text"},
												{"null", ATS_INVALID, CODEC_OFFSET(print_struct),
														"Verify (decode) input, but do not output"},
														{0, ATS_INVALID, 0, 0}};

static int
has_codec_defined(const asn_TYPE_descriptor_t *td,
		const syntax_selector *element) {
	return *(const void *const *)(const void *)((const char *)td->op
			+ element->codec_offset) != 0;
}

/*
 * Select ASN.1 Transfer Enocoding Syntax by command line name.
 */
static const syntax_selector *
ats_by_name(const char *name, const asn_TYPE_descriptor_t *td,
		const syntax_selector *first_element) {
	const syntax_selector *element;
	for(element = first_element; element->name; element++) {
		if(strcmp(element->name, name) == 0) {
			if(td && td->op && has_codec_defined(td, element)) {
				return element;
			}
		}
	}
	return NULL;
}

int main(int ac, char *av[]) 
{

	unsigned char map_encdata[] = {0x00,0x12,0x1E,0x73,0x00,0x03,0x20,0xA4,0x66,0x90,0x89,0x18,0x74,0xA0,0x91,0x97,0x66,0xCD,0xE1,0x51,0x32,0xE1,0xE4,0x82,0x76,0x1E,0xD9,0x72,0xEE,0x00,0x64,0x00,0xC0};
	MessageFrame_t *saeMap_decoded = NULL;
	asn_dec_rval_t rv;
	rv = uper_decode(NULL, &asn_DEF_MessageFrame, (void **)&saeMap_decoded, map_encdata, MAX_BUF_LEN, 0, 0);

	if(rv.code == RC_FAIL) {
		printf("DBG: Error in DER Decode\n");
		free(saeMap_decoded);
		return -1;
	}
	else if (rv.code == RC_WMORE)
	{
		printf("DBG: MAP_MSG  UPER DECODE SUCCESSFUL but require More data\n");
		free(saeMap_decoded);
		return 1;
	}
	else /*RC_OK */
	{
		printf("DBG: MAP UPER DECODE SUCCESSFUL with %ld Bytes Consumed\n", rv.consumed);

		/*Populate the test BSM data to SAE BSM Structure*/
		/*memset(&bsm_msg_to_decode, 0, sizeof(bsm_msg_to_decode));*/

		printf("\n  MAP_msg_Id = %u \n",              saeMap_decoded->messageId);
		printf("\n  MAP_msg_MinuteOfTheYear = %u \n", *saeMap_decoded->value.choice.MapData.timeStamp);
		printf("\n  MAP_msg_MsgCnt = %u \n",          saeMap_decoded->value.choice.MapData.msgIssueRevision);
		printf("\n  MAP_msg_Layer_type = %u \n",      *saeMap_decoded->value.choice.MapData.layerType);
		printf("\n  MAP_msg_Layer_ID = %u \n",        *saeMap_decoded->value.choice.MapData.layerID);

		//printf("\n dp_processMethod = %u \n",        map->dp_processMethod);

		//printf("\n dp_geoidUsed = %u \n",        map->dp_geoidUsed);

		printf("\n  rl_id = %u \n",        saeMap_decoded->value.choice.MapData.restrictionList->list.array[0]->id);

		printf("\n  rl_users_basicType = %u \n",        saeMap_decoded->value.choice.MapData.restrictionList->list.array[0]->users.list.array[0]->choice.basicType);

		free(saeMap_decoded);
		return 0;

	}



#if 0
	FILE *binary_out;
	asn_TYPE_descriptor_t *pduType = PDU_Type_Ptr;
	asn_TYPE_descriptor_t *anyPduType = PDU_Type_Ptr;
	ssize_t suggested_bufsize = 8192;  /* close or equal to stdio buffer */
	int number_of_iterations = 1;
	int num;
	int ch;
	const syntax_selector *sel;
	enum asn_transfer_syntax isyntax = ATS_INVALID;
	enum asn_transfer_syntax osyntax = ATS_BASIC_XER;

	if(!anyPduType)
	{
#ifdef  ASN_PDU_COLLECTION
		anyPduType = asn_pdu_collection[0];
		if(!anyPduType)
		{
			fprintf(stderr,
					"Empty PDU collection, no reference PDU to choose from.\n");
			exit(EX_SOFTWARE);
		}
#else
		fprintf(stderr, "Either asn1c -pdu=... or cc -DPDU should be used.\n");
		exit(EX_SOFTWARE);
#endif
	}

	/* Figure out if a specialty decoder needs to be default */
#ifndef ASN_DISABLE_OER_SUPPORT
	isyntax = ATS_BASIC_OER;
#endif
#ifndef ASN_DISABLE_PER_SUPPORT
	isyntax = ATS_UNALIGNED_BASIC_PER;
#endif

	/*
	 * Pocess the command-line argments.
	 */
	while((ch = getopt(ac, av, "i:o:1b:cdn:p:hs:" JUNKOPT RANDOPT)) != -1)
		switch(ch)
		{
		case 'i':
			sel = ats_by_name(optarg, anyPduType, input_encodings);
			if(sel) 
			{
				isyntax = sel->syntax;
			} 
			else 
			{
				fprintf(stderr, "-i<format>: '%s': improper format selector\n",
						optarg);
				exit(EX_UNAVAILABLE);
			}
			fprintf(stderr,"I'm in i\n");
			break;
		case 'o':
			sel = ats_by_name(optarg, anyPduType, output_encodings);
			if(sel) 
			{
				osyntax = sel->syntax;
			} 
			else 
			{
				fprintf(stderr, "-o<format>: '%s': improper format selector\n",
						optarg);
				exit(EX_UNAVAILABLE);
			}
			fprintf(stderr,"I'm in o\n");
			break;
		case '1':
			opt_onepdu = 1;
			fprintf(stderr,"I'm in 1\n");
			break;
		case 'b':
			suggested_bufsize = atoi(optarg);
			if(suggested_bufsize < 1 || suggested_bufsize > 16 * 1024 * 1024)
			{
				fprintf(stderr,"-b %s: Improper buffer size (1..16M)\n",optarg);
				exit(EX_UNAVAILABLE);
			}
			fprintf(stderr,"I'm in b\n");
			break;
		case 'c':
			opt_check = 1;
			fprintf(stderr,"I'm in c\n");
			break;
		case 'd':
			opt_debug++;    /* Double -dd means ASN.1 debug */
			fprintf(stderr,"I'm in d\n");
			break;
		case 'n':
			fprintf(stderr,"I'm in n\n");
			number_of_iterations = atoi(optarg);
			if(number_of_iterations < 1) 
			{
				fprintf(stderr,
						"-n %s: Improper iterations count\n", optarg);
				exit(EX_UNAVAILABLE);
			}
			break;
		case 'p':
			fprintf(stderr,"I'm in p\n");
			if(strcmp(optarg, "er-nopad") == 0) {
				opt_nopad = 1;
				break;
			}
#ifdef    ASN_PDU_COLLECTION
			if(strcmp(optarg, "list") == 0) {
				asn_TYPE_descriptor_t **pdu = asn_pdu_collection;
				fprintf(stderr, "Available PDU types:\n");
				for(; *pdu; pdu++) printf("%s\n", (*pdu)->name);
				exit(0);
			} else if(optarg[0] >= 'A' && optarg[0] <= 'Z') {
				asn_TYPE_descriptor_t **pdu = asn_pdu_collection;
				while(*pdu && strcmp((*pdu)->name, optarg)) pdu++;
				if(*pdu) { pduType = *pdu; break; }
				fprintf(stderr, "-p %s: Unrecognized PDU. Try '-p list'.\n",
						optarg);
				exit(EX_USAGE);
			}
#else   /* Without -pdu=auto there's just a single type */
			if(strcmp(optarg, "list") == 0) {
				fprintf(stderr, "Available PDU types:\n");
				if(pduType) {
					printf("%s\n", pduType->name);
				}
				exit(0);
			} else if(optarg[0] >= 'A' && optarg[0] <= 'Z') {
				if(pduType && strcmp(optarg, pduType->name) == 0) {
					break;
				}
				fprintf(stderr, "-p %s: Unrecognized PDU. Try '-p list'.\n",
						optarg);
				exit(EX_USAGE);
			}
#endif    /* ASN_PDU_COLLECTION */
			fprintf(stderr, "-p %s: Unrecognized option\n", optarg);
			exit(EX_UNAVAILABLE);
		case 's':
			fprintf(stderr,"I'm in s\n");
			opt_stack = atoi(optarg);
			if(opt_stack < 0) {
				fprintf(stderr,
						"-s %s: Non-negative value expected\n",
						optarg);
				exit(EX_UNAVAILABLE);
			}
			break;
#ifdef    JUNKTEST
		case 'J':
			fprintf(stderr,"I'm in J\n");
			opt_jprob = strtod(optarg, 0);
			if(opt_jprob <= 0.0 || opt_jprob > 1.0) {
				fprintf(stderr,
						"-J %s: Probability range 0..1 expected \n",
						optarg);
				exit(EX_UNAVAILABLE);
			}
			break;
		case 'R':
			fprintf(stderr,"I'm in R\n");
			isyntax = ATS_RANDOM;
			random_max_size = atoi(optarg);
			if(random_max_size < 0) {
				fprintf(stderr,
						"-R %s: Non-negative value expected\n",
						optarg);
				exit(EX_UNAVAILABLE);
			}
			srandomdev();
			break;
#endif    /* JUNKTEST */
		case 'h':
			fprintf(stderr,"I'm in h\n");
		default:
			fprintf(stderr,"I'm in default\n");
#ifdef    ASN_CONVERTER_TITLE
#define    _AXS(x)    #x
#define    _ASX(x)    _AXS(x)
			fprintf(stderr, "%s\n", _ASX(ASN_CONVERTER_TITLE));
#endif
			fprintf(stderr, "Usage: %s [options] <datafile> ...\n", av[0]);
			fprintf(stderr, "Where options are:\n");
			for(sel = input_encodings; sel->name; sel++) {
				if(ats_by_name(sel->name, anyPduType, sel)) {
					fprintf(stderr, "  -i%s        %s%s\n", sel->name,
							sel->full_name,
							(sel->syntax == isyntax) ? " (DEFAULT)" : "");
				}
			}
			for(sel = output_encodings; sel->name; sel++) {
				if(ats_by_name(sel->name, anyPduType, sel)) {
					fprintf(stderr, "  -o%s%s       %s%s\n", sel->name,
							strlen(sel->name) > 3 ? "" : " ",
									sel->full_name,
									(sel->syntax == osyntax) ? " (DEFAULT)" : "");
				}
			}
			if(anyPduType->op->uper_decoder) {
				fprintf(stderr,
						"  -per-nopad   Assume PER PDUs are not padded (-iper)\n");
			}
#ifdef    ASN_PDU_COLLECTION
			fprintf(stderr,
					"  -p <PDU>     Specify PDU type to decode\n"
					"  -p list      List available PDUs\n");
#endif    /* ASN_PDU_COLLECTION */
			fprintf(stderr,
					"  -1           Decode only the first PDU in file\n"
					"  -b <size>    Set the i/o buffer size (default is %ld)\n"
					"  -c           Check ASN.1 constraints after decoding\n"
					"  -d           Enable debugging (-dd is even better)\n"
					"  -n <num>     Process files <num> times\n"
					"  -s <size>    Set the stack usage limit (default is %d)\n"
#ifdef    JUNKTEST
					"  -J <prob>    Set random junk test bit garbaging probability\n"
					"  -R <size>    Generate a random value of roughly the given size,\n"
					"               instead of parsing the value from file.\n"
#endif
					, (long)suggested_bufsize, ASN__DEFAULT_STACK_MAX);
			exit(EX_USAGE);
		}

	ac -= optind;
	av += optind;

	if(!pduType) {
#ifdef  NO_ASN_PDU
		fprintf(stderr, "No -DPDU defined during compilation.\n");
		exit(0);
#else
		fprintf(stderr, "Use '-p <Type>' or '-p list' to select ASN.1 type.\n");
		exit(EX_USAGE);
#endif  /* NO_ASN_PDU */
	}

	if(ac < 1 && isyntax != ATS_RANDOM) {
		fprintf(stderr, "%s: No input files specified. "
				"Try '-h' for more information\n",
				av[-optind]);
		exit(EX_USAGE);
	}

	if(isatty(1)) {
		const int is_text_output = osyntax == ATS_NONSTANDARD_PLAINTEXT
				|| osyntax == ATS_BASIC_XER
				|| osyntax == ATS_CANONICAL_XER;
		if(is_text_output) {
			binary_out = stdout;
		} else {
			fprintf(stderr, "(Suppressing binary output to a terminal.)\n");
			binary_out = fopen("/dev/null", "wb");
			if(!binary_out) {
				fprintf(stderr, "Can't open /dev/null: %s\n", strerror(errno));
				exit(EX_OSERR);
			}
		}
	} else {
		binary_out = stdout;
	}
	setvbuf(stdout, 0, _IOLBF, 0);

	for(num = 0; num < number_of_iterations; num++) {
		int ac_i;
		/*
		 * Process all files in turn.
		 */
		for(ac_i = (isyntax == ATS_RANDOM) ? -1 : 0; ac_i < ac; ac_i++) {
			asn_enc_rval_t erv;
			void *structure;    /* Decoded structure */
			FILE *file;
			char *name;
			int first_pdu;

			if(ac_i == -1) {
				file = NULL;
				name = "<random value generator>";
				opt_onepdu = 1;
			} else {
				file = argument_to_file(av, ac_i);
				name = argument_to_name(av, ac_i);
			}

			for(first_pdu = 1; (first_pdu || !opt_onepdu); first_pdu = 0) {
				/*
				 * Decode the encoded structure from file.
				 */
#ifdef  JUNKTEST
				if(isyntax == ATS_RANDOM) {
					structure = NULL;
					if(asn_random_fill(pduType, &structure, random_max_size) != 0) {
						fprintf(stderr, "Cannot generate a random value.\n");
						assert(structure == NULL);
						errno = EINVAL;
					}
				} else {
#endif
					structure = data_decode_from_file(isyntax, pduType, file, name,
							suggested_bufsize, first_pdu);
#ifdef  JUNKTEST
				}
#endif
				if(!structure) {
					if(errno) {
						/* Error message is already printed */
						exit(EX_DATAERR);
					} else {
						/* EOF */
						break;
					}
				}

				/* Check ASN.1 constraints */
				if(opt_check) {
					char errbuf[128];
					size_t errlen = sizeof(errbuf);
					if(asn_check_constraints(pduType, structure, errbuf, &errlen)) {
						fprintf(stderr,
								"%s: ASN.1 constraint "
								"check failed: %s\n",
								name, errbuf);
						exit(EX_DATAERR);
					}
				}

				if(osyntax == ATS_INVALID) {
#ifdef JUNKTEST
					if(opt_jprob == 0.0) {
						fprintf(stderr, "%s: decoded successfully\n", name);
					}
#else
					fprintf(stderr, "%s: decoded successfully\n", name);
#endif
				} else {
					erv = asn_encode(NULL, osyntax, pduType, structure, write_out,
							binary_out);

					if(erv.encoded == -1) {
						fprintf(stderr, "%s: Cannot convert %s into %s\n", name,
								pduType->name, ats_simple_name(osyntax));
						DEBUG("Conversion failed for %s:\n", pduType->name);
						asn_fprint(stderr, pduType, structure);
						exit(EX_UNAVAILABLE);
					}
					DEBUG("Encoded in %" ASN_PRI_SSIZE " bytes of %s", erv.encoded,
							ats_simple_name(osyntax));
				}

				ASN_STRUCT_FREE(*pduType, structure);
			}

			if(file && file != stdin) {
				fclose(file);
			}
		}
	}

#ifdef    JUNKTEST
	if(opt_jprob > 0.0) {
		fprintf(stderr, "Junked %f OK (%d/%d)\n",
				opt_jprob, junk_failures, number_of_iterations);
	}
#endif    /* JUNKTEST */
#endif
	return 0;
}

static struct dynamic_buffer {
	uint8_t *data;        /* Pointer to the data bytes */
	size_t offset;        /* Offset from the start */
	size_t length;        /* Length of meaningful contents */
	size_t unbits;        /* Unused bits in the last byte */
	size_t allocated;    /* Allocated memory for data */
	int    nreallocs;    /* Number of data reallocations */
	off_t  bytes_shifted;    /* Number of bytes ever shifted */
} DynamicBuffer;

static void
buffer_dump() {
	uint8_t *p = DynamicBuffer.data + DynamicBuffer.offset;
	uint8_t *e = p + DynamicBuffer.length - (DynamicBuffer.unbits ? 1 : 0);
	if(!opt_debug) return;
	DEBUG("Buffer: { d=%p, o=%" ASN_PRI_SIZE ", l=%" ASN_PRI_SIZE
			", u=%" ASN_PRI_SIZE ", a=%" ASN_PRI_SIZE ", s=%" ASN_PRI_SIZE " }",
			(const void *)DynamicBuffer.data,
			DynamicBuffer.offset,
			DynamicBuffer.length,
			DynamicBuffer.unbits,
			DynamicBuffer.allocated,
			(size_t)DynamicBuffer.bytes_shifted);
	for(; p < e; p++) {
		fprintf(stderr, " %c%c%c%c%c%c%c%c",
				((*p >> 7) & 1) ? '1' : '0',
						((*p >> 6) & 1) ? '1' : '0',
								((*p >> 5) & 1) ? '1' : '0',
										((*p >> 4) & 1) ? '1' : '0',
												((*p >> 3) & 1) ? '1' : '0',
														((*p >> 2) & 1) ? '1' : '0',
																((*p >> 1) & 1) ? '1' : '0',
																		((*p >> 0) & 1) ? '1' : '0');
	}
	if(DynamicBuffer.unbits) {
		unsigned int shift;
		fprintf(stderr, " ");
		for(shift = 7; shift >= DynamicBuffer.unbits; shift--)
			fprintf(stderr, "%c", ((*p >> shift) & 1) ? '1' : '0');
		fprintf(stderr, " %" ASN_PRI_SSIZE ":%" ASN_PRI_SSIZE "\n",
				(ssize_t)DynamicBuffer.length - 1,
				(ssize_t)8 - DynamicBuffer.unbits);
	} else {
		fprintf(stderr, " %ld\n", (long)DynamicBuffer.length);
	}
}

/*
 * Move the buffer content left N bits, possibly joining it with
 * preceeding content.
 */
static void
buffer_shift_left(size_t offset, int bits) {
	uint8_t *ptr = DynamicBuffer.data + DynamicBuffer.offset + offset;
	uint8_t *end = DynamicBuffer.data + DynamicBuffer.offset
			+ DynamicBuffer.length - 1;

	if(!bits) return;

	DEBUG("Shifting left %d bits off %ld (o=%ld, u=%ld, l=%ld)",
			bits, (long)offset,
			(long)DynamicBuffer.offset,
			(long)DynamicBuffer.unbits,
			(long)DynamicBuffer.length);

	if(offset) {
		int right;
		right = ptr[0] >> (8 - bits);

		DEBUG("oleft: %c%c%c%c%c%c%c%c",
				((ptr[-1] >> 7) & 1) ? '1' : '0',
						((ptr[-1] >> 6) & 1) ? '1' : '0',
								((ptr[-1] >> 5) & 1) ? '1' : '0',
										((ptr[-1] >> 4) & 1) ? '1' : '0',
												((ptr[-1] >> 3) & 1) ? '1' : '0',
														((ptr[-1] >> 2) & 1) ? '1' : '0',
																((ptr[-1] >> 1) & 1) ? '1' : '0',
																		((ptr[-1] >> 0) & 1) ? '1' : '0');

		DEBUG("oriht: %c%c%c%c%c%c%c%c",
				((ptr[0] >> 7) & 1) ? '1' : '0',
						((ptr[0] >> 6) & 1) ? '1' : '0',
								((ptr[0] >> 5) & 1) ? '1' : '0',
										((ptr[0] >> 4) & 1) ? '1' : '0',
												((ptr[0] >> 3) & 1) ? '1' : '0',
														((ptr[0] >> 2) & 1) ? '1' : '0',
																((ptr[0] >> 1) & 1) ? '1' : '0',
																		((ptr[0] >> 0) & 1) ? '1' : '0');

		DEBUG("mriht: %c%c%c%c%c%c%c%c",
				((right >> 7) & 1) ? '1' : '0',
						((right >> 6) & 1) ? '1' : '0',
								((right >> 5) & 1) ? '1' : '0',
										((right >> 4) & 1) ? '1' : '0',
												((right >> 3) & 1) ? '1' : '0',
														((right >> 2) & 1) ? '1' : '0',
																((right >> 1) & 1) ? '1' : '0',
																		((right >> 0) & 1) ? '1' : '0');

		ptr[-1] = (ptr[-1] & (0xff << bits)) | right;

		DEBUG("after: %c%c%c%c%c%c%c%c",
				((ptr[-1] >> 7) & 1) ? '1' : '0',
						((ptr[-1] >> 6) & 1) ? '1' : '0',
								((ptr[-1] >> 5) & 1) ? '1' : '0',
										((ptr[-1] >> 4) & 1) ? '1' : '0',
												((ptr[-1] >> 3) & 1) ? '1' : '0',
														((ptr[-1] >> 2) & 1) ? '1' : '0',
																((ptr[-1] >> 1) & 1) ? '1' : '0',
																		((ptr[-1] >> 0) & 1) ? '1' : '0');
	}

	buffer_dump();

	for(; ptr < end; ptr++) {
		int right = ptr[1] >> (8 - bits);
		*ptr = (*ptr << bits) | right;
	}
	*ptr <<= bits;

	DEBUG("Unbits [%" ASN_PRI_SIZE "=>", DynamicBuffer.unbits);
	if(DynamicBuffer.unbits == 0) {
		DynamicBuffer.unbits += bits;
	} else {
		DynamicBuffer.unbits += bits;
		if(DynamicBuffer.unbits > 7) {
			DynamicBuffer.unbits -= 8;
			DynamicBuffer.length--;
			DynamicBuffer.bytes_shifted++;
		}
	}
	DEBUG("Unbits =>%" ASN_PRI_SIZE "]", DynamicBuffer.unbits);

	buffer_dump();

	DEBUG("Shifted. Now (o=%" ASN_PRI_SIZE ", u=%" ASN_PRI_SIZE
			" l=%" ASN_PRI_SIZE ")",
			DynamicBuffer.offset,
			DynamicBuffer.unbits,
			DynamicBuffer.length);
}

/*
 * Ensure that the buffer contains at least this amount of free space.
 */
static void add_bytes_to_buffer(const void *data2add, size_t bytes) {

	if(bytes == 0) return;

	DEBUG("=> add_bytes(%" ASN_PRI_SIZE ") { o=%" ASN_PRI_SIZE
			" l=%" ASN_PRI_SIZE " u=%" ASN_PRI_SIZE ", s=%" ASN_PRI_SIZE " }",
			bytes,
			DynamicBuffer.offset,
			DynamicBuffer.length,
			DynamicBuffer.unbits,
			DynamicBuffer.allocated);

	if(DynamicBuffer.allocated
			>= (DynamicBuffer.offset + DynamicBuffer.length + bytes)) {
		DEBUG("\tNo buffer reallocation is necessary");
	} else if(bytes <= DynamicBuffer.offset) {
		DEBUG("\tContents shifted by %ld", DynamicBuffer.offset);

		/* Shift the buffer contents */
		memmove(DynamicBuffer.data,
				DynamicBuffer.data + DynamicBuffer.offset,
				DynamicBuffer.length);
		DynamicBuffer.bytes_shifted += DynamicBuffer.offset;
		DynamicBuffer.offset = 0;
	} else {
		size_t newsize = (DynamicBuffer.allocated << 2) + bytes;
		void *p = MALLOC(newsize);
		if(!p) {
			perror("malloc()");
			exit(EX_OSERR);
		}
		memcpy(p,
				DynamicBuffer.data + DynamicBuffer.offset,
				DynamicBuffer.length);
		FREEMEM(DynamicBuffer.data);
		DynamicBuffer.data = (uint8_t *)p;
		DynamicBuffer.offset = 0;
		DynamicBuffer.allocated = newsize;
		DynamicBuffer.nreallocs++;
		DEBUG("\tBuffer reallocated to %ld (%d time)",
				newsize, DynamicBuffer.nreallocs);
	}

	memcpy(DynamicBuffer.data
			+ DynamicBuffer.offset + DynamicBuffer.length,
			data2add, bytes);
	DynamicBuffer.length += bytes;
	if(DynamicBuffer.unbits) {
		int bits = DynamicBuffer.unbits;
		DynamicBuffer.unbits = 0;
		buffer_shift_left(DynamicBuffer.length - bytes, bits);
	}

	DEBUG("<= add_bytes(%" ASN_PRI_SIZE ") { o=%" ASN_PRI_SIZE
			" l=%" ASN_PRI_SIZE " u=%" ASN_PRI_SIZE ", s=%" ASN_PRI_SIZE " }",
			bytes,
			DynamicBuffer.offset,
			DynamicBuffer.length,
			DynamicBuffer.unbits,
			DynamicBuffer.allocated);
}

static int
is_syntax_PER(enum asn_transfer_syntax syntax) {
	return (syntax == ATS_UNALIGNED_BASIC_PER
			|| syntax == ATS_UNALIGNED_CANONICAL_PER);
}

static int
restartability_supported(enum asn_transfer_syntax syntax) {
	return !is_syntax_PER(syntax);
}

static void *
data_decode_from_file(enum asn_transfer_syntax isyntax, asn_TYPE_descriptor_t *pduType, FILE *file, const char *name, ssize_t suggested_bufsize, int on_first_pdu) {
	static uint8_t *fbuf;
	static ssize_t fbuf_size;
	static asn_codec_ctx_t s_codec_ctx;
	asn_codec_ctx_t *opt_codec_ctx = 0;
	void *structure = 0;
	asn_dec_rval_t rval;
	size_t old_offset;
	size_t new_offset;
	int tolerate_eof;
	size_t rd;

	if(!file) {
		fprintf(stderr, "%s: %s\n", name, strerror(errno));
		errno = EINVAL;
		return 0;
	}

	if(opt_stack) {
		s_codec_ctx.max_stack_size = opt_stack;
		opt_codec_ctx = &s_codec_ctx;
	}

	DEBUG("Processing %s", name);

	/* prepare the file buffer */
	if(fbuf_size != suggested_bufsize) {
		fbuf = (uint8_t *)REALLOC(fbuf, suggested_bufsize);
		if(!fbuf) {
			perror("realloc()");
			exit(EX_OSERR);
		}
		fbuf_size = suggested_bufsize;
	}

	if(on_first_pdu) {
		DynamicBuffer.offset = 0;
		DynamicBuffer.length = 0;
		DynamicBuffer.unbits = 0;
		DynamicBuffer.allocated = 0;
		DynamicBuffer.bytes_shifted = 0;
		DynamicBuffer.nreallocs = 0;
	}

	old_offset = DynamicBuffer.bytes_shifted + DynamicBuffer.offset;

	/* Pretend immediate EOF */
	rval.code = RC_WMORE;
	rval.consumed = 0;

	for(tolerate_eof = 1;    /* Allow EOF first time buffer is non-empty */
			(rd = fread(fbuf, 1, fbuf_size, file))
        				|| feof(file) == 0
        				|| (tolerate_eof && DynamicBuffer.length)
        				;) {
		int      ecbits = 0;    /* Extra consumed bits in case of PER */
		uint8_t *i_bptr;
		size_t   i_size;

		/*
		 * Copy the data over, or use the original buffer.
		 */
		if(DynamicBuffer.allocated) {
			/* Append new data into the existing dynamic buffer */
			add_bytes_to_buffer(fbuf, rd);
			i_bptr = DynamicBuffer.data + DynamicBuffer.offset;
			i_size = DynamicBuffer.length;
		} else {
			i_bptr = fbuf;
			i_size = rd;
		}

		DEBUG("Decoding %" ASN_PRI_SIZE " bytes", i_size);

#ifdef    JUNKTEST
		junk_bytes_with_probability(i_bptr, i_size, opt_jprob);
#endif

		if(is_syntax_PER(isyntax) && opt_nopad) {
#ifdef  ASN_DISABLE_PER_SUPPORT
			rval.code = RC_FAIL;
			rval.consumed = 0;
#else
			rval = uper_decode(opt_codec_ctx, pduType, (void **)&structure,
					i_bptr, i_size, 0, DynamicBuffer.unbits);
			/* uper_decode() returns bits! */
			ecbits = rval.consumed % 8; /* Bits consumed from the last byte */
			rval.consumed >>= 3;    /* Convert bits into bytes. */
#endif
			/* Non-padded PER decoder */
		} else {
			rval = asn_decode(opt_codec_ctx, isyntax, pduType,
					(void **)&structure, i_bptr, i_size);
		}
		if(rval.code == RC_WMORE && !restartability_supported(isyntax)) {
			/* PER does not support restartability */
			ASN_STRUCT_FREE(*pduType, structure);
			structure = 0;
			rval.consumed = 0;
			/* Continue accumulating data */
		}

		DEBUG("decode(%" ASN_PRI_SIZE ") consumed %" ASN_PRI_SIZE
				"+%db (%" ASN_PRI_SIZE "), code %d",
				DynamicBuffer.length, rval.consumed, ecbits, i_size, rval.code);

		if(DynamicBuffer.allocated == 0) {
			/*
			 * Flush remainder into the intermediate buffer.
			 */
			if(rval.code != RC_FAIL && rval.consumed < rd) {
				add_bytes_to_buffer(fbuf + rval.consumed,
						rd - rval.consumed);
				buffer_shift_left(0, ecbits);
				DynamicBuffer.bytes_shifted = rval.consumed;
				rval.consumed = 0;
				ecbits = 0;
			}
		}

		/*
		 * Adjust position inside the source buffer.
		 */
		if(DynamicBuffer.allocated) {
			DynamicBuffer.offset += rval.consumed;
			DynamicBuffer.length -= rval.consumed;
		} else {
			DynamicBuffer.bytes_shifted += rval.consumed;
		}

		switch(rval.code) {
		case RC_OK:
			if(ecbits) buffer_shift_left(0, ecbits);
			DEBUG("RC_OK, finishing up with %ld+%d",
					(long)rval.consumed, ecbits);
			return structure;
		case RC_WMORE:
			DEBUG("RC_WMORE, continuing read=%ld, cons=%ld "
					" with %ld..%ld-%ld..%ld",
					(long)rd,
					(long)rval.consumed,
					(long)DynamicBuffer.offset,
					(long)DynamicBuffer.length,
					(long)DynamicBuffer.unbits,
					(long)DynamicBuffer.allocated);
			if(!rd) tolerate_eof--;
			continue;
		case RC_FAIL:
			break;
		}
		break;
	}

	DEBUG("Clean up partially decoded %s", pduType->name);
	ASN_STRUCT_FREE(*pduType, structure);

	new_offset = DynamicBuffer.bytes_shifted + DynamicBuffer.offset;

	/*
	 * Print a message and return failure only if not EOF,
	 * unless this is our first PDU (empty file).
	 */
	if(on_first_pdu
			|| DynamicBuffer.length
			|| new_offset - old_offset > ((isyntax == ATS_BASIC_XER)?sizeof("\r\n")-1:0)
	) {

#ifdef    JUNKTEST
		/*
		 * Nothing's wrong with being unable to decode junk.
		 * Simulate EOF.
		 */
		if(opt_jprob != 0.0) {
			junk_failures++;
			errno = 0;
			return 0;
		}
#endif

		DEBUG("ofp %d, no=%ld, oo=%ld, dbl=%ld",
				on_first_pdu, (long)new_offset, (long)old_offset,
				(long)DynamicBuffer.length);
		fprintf(stderr, "%s: "
				"Decode failed past byte %ld: %s\n",
				name, (long)new_offset,
				(rval.code == RC_WMORE)
				? "Unexpected end of input"
						: "Input processing error");
#ifndef    ENOMSG
#define    ENOMSG EINVAL
#endif
#ifndef    EBADMSG
#define    EBADMSG EINVAL
#endif
		errno = (rval.code == RC_WMORE) ? ENOMSG : EBADMSG;
	} else {
		/* Got EOF after a few successful PDUs */
		errno = 0;
	}

	return 0;
}

/* Dump the buffer out to the specified FILE */
static int write_out(const void *buffer, size_t size, void *key) {
	FILE *fp = (FILE *)key;
	return (fwrite(buffer, 1, size, fp) == size) ? 0 : -1;
}

static int argument_is_stdin(char *av[], int idx) {
	if(strcmp(av[idx], "-")) {
		return 0; /* Certainly not <stdin> */
	} else {
		/* This might be <stdin>, unless `./program -- -` */
		if(strcmp(av[-1], "--"))
			return 1;
		else
			return 0;
	}
}

static FILE *argument_to_file(char *av[], int idx) {
	return argument_is_stdin(av, idx) ? stdin : fopen(av[idx], "rb");
}

static char *argument_to_name(char *av[], int idx) {
	return argument_is_stdin(av, idx) ? "standard input" : av[idx];
}

#ifdef    JUNKTEST
/*
 * Fill bytes with some garbage with specified probability (more or less).
 */
static void
junk_bytes_with_probability(uint8_t *buf, size_t size, double prob) {
	static int junkmode;
	uint8_t *ptr;
	uint8_t *end;
	if(opt_jprob <= 0.0) return;
	for(ptr = buf, end = ptr + size; ptr < end; ptr++) {
		int byte = *ptr;
		if(junkmode++ & 1) {
			if((((double)random() / RAND_MAX) < prob))
				byte = random() & 0xff;
		} else {
#define    BPROB(b)    ((((double)random() / RAND_MAX) < prob) ? b : 0)
			byte ^= BPROB(0x80);
			byte ^= BPROB(0x40);
			byte ^= BPROB(0x20);
			byte ^= BPROB(0x10);
			byte ^= BPROB(0x08);
			byte ^= BPROB(0x04);
			byte ^= BPROB(0x02);
			byte ^= BPROB(0x01);
		}
		if(byte != *ptr) {
			*ptr = byte;
		}
	}
}
#endif    /* JUNKTEST */