epg/descriptor.c

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <time.h>
#include <strings.h>

#include "lint.h"

struct descriptor *
read_descriptor_header(struct epg *epg)
{
	static struct descriptor d;

	if (epg->binsize - epg->offset < 2)
		return NULL;

	memcpy(&d, epg->bin + epg->offset, 2);

	epg->offset += 2;

	return &d;
}

static char *
string_to_end(struct epg *epg, struct descriptor *d, int sofar,
    unsigned int *len)
{
	int rest = d->len - sofar;
	char *str;

	*len = rest;

	if (rest <= 0)
		return NULL;;

	str = (char *)malloc(rest + 1);
	memcpy(str, epg->bin + epg->offset, rest);
	str[rest] = '\0';
	epg->offset += rest;

	return str;
}

void
read_descriptor(struct epg *epg, struct descriptor *d)
{
	switch (d->tag)
	{
	    case DS_SHORT_EVENT: 
		memcpy(d->content.d77.lang, epg->bin + epg->offset, 3);
		epg->offset += 3;

		d->content.d77.namelen = epg->bin[epg->offset++];
		d->content.d77.name = read_string_len(epg->bin + epg->offset,
		    d->content.d77.namelen);
		epg->offset += d->content.d77.namelen;

		d->content.d77.textlen = epg->bin[epg->offset++];
		d->content.d77.text = read_string_len(epg->bin + epg->offset,
		    d->content.d77.textlen);
		epg->offset += d->content.d77.textlen;

		break;

	    case DS_COMPONENT:
		memcpy(&d->content.d80, epg->bin + epg->offset, 6);
		epg->offset += 6;

		d->content.d80.text = string_to_end(epg, d, 6,
		    &d->content.d80.textlen);
		break;

	    case DS_USER_DEFINED:
		d->content.d137.textlen = epg->bin[epg->offset++];
		d->content.d137.text = read_string_len(epg->bin + epg->offset,
		    d->content.d137.textlen);
		epg->offset += d->content.d137.textlen;

		memcpy(d->content.d137.lang, epg->bin + epg->offset, 3);
		epg->offset += 3;
		d->content.d137.warning = string_to_end(epg, d,
		    4 + d->content.d137.textlen,
		    &d->content.d137.warninglen);
		break;

	    case DS_CONTENT_IDENTIFIER:
		memcpy(&d->content.d118, epg->bin + epg->offset, 1);
		epg->offset++;
		d->content.d118.cridlen = d->content.d118.ref = 0;
		switch (d->content.d118.location)
		{
		    case 0:
			d->content.d118.cridlen = epg->bin[epg->offset++];
			d->content.d118.crid = read_string_len(
			    epg->bin + epg->offset, d->content.d118.cridlen);
			epg->offset += d->content.d118.cridlen;
			break;
			
		    case 1:
			d->content.d118.ref =
			    _swap16((uint16_t)epg->bin[epg->offset]);
			/* Not safe to use post increment in macro */
			epg->offset++;
			break;
		    default:
			printf("Unknown CRID location - %d\n",
			    d->content.d118.location);
		}
		break;

	    default:
		printf("Default descriptor: %d\n", d->tag);
	    case DS_LINKAGE:
	    case DS_CONTENT:	
	    case DS_PRIVATE_DATA_SPECIFIER:
	    case DS_FTA_CONTENT_MGMT:
		d->content.unknown.text = string_to_end(epg, d, 0,
		    &d->content.unknown.textlen);
		break;
	}
}

inline void
skip_descriptor(struct epg *epg, struct descriptor *d)
{
	epg->offset += d->len;
}

void
free_descriptor(struct descriptor *d)
{
	switch (d->tag)
	{
	    case DS_SHORT_EVENT:
		if (d->content.d77.name)
			free(d->content.d77.name);
		if (d->content.d77.text)
			free(d->content.d77.text);
		break;
	    case DS_COMPONENT:
		if (d->content.d80.text)
			free(d->content.d80.text);
		break;
	    case DS_USER_DEFINED:
		if (d->content.d137.text)
			free(d->content.d137.text);
		if (d->content.d137.warning)
			free(d->content.d137.warning);
		break;
	    case DS_CONTENT_IDENTIFIER:
		if (d->content.d118.crid)
			free(d->content.d118.crid);
		break;
	    default:
		if (d->content.unknown.text)
			free(d->content.unknown.text);
		break;
	}
}

char *
descriptor_name(struct descriptor *d)
{
	switch (d->tag)
	{
	    case DS_LINKAGE:			return "linkage";
	    case DS_SHORT_EVENT:		return "short event";
	    case DS_COMPONENT:			return "component";
	    case DS_CONTENT:			return "content";
	    case DS_PRIVATE_DATA_SPECIFIER:	return "private data spec.";
	    case DS_CONTENT_IDENTIFIER:		return "content id";
	    case DS_FTA_CONTENT_MGMT:		return "content mgmt";
	    case DS_USER_DEFINED:		return "user defined";
	    default:				return "Unknown";
	}
	return "Unknown";
}

void
dump_descriptor(struct descriptor *d, int content)
{
	printf("Descriptor header:\n");
	printf("    %30s: %#x [%d] (%s)\n", "descriptor", d->tag, d->tag,
	    descriptor_name(d));
	DUMPINT(d, len);

	if (!content)
		return;

	switch (d->tag)
	{
	    case DS_SHORT_EVENT:
		DUMPNSTR(d, content.d77.lang, 3);
		DUMPINT(d, content.d77.namelen);
		//DUMPNSTR(d, content.d77.name, d->content.d77.namelen);
		DUMPHEX(d, content.d77.name, d->content.d77.namelen);
		DUMPINT(d, content.d77.textlen);
		//DUMPNSTR(d, content.d77.text, d->content.d77.textlen);
		DUMPHEX(d, content.d77.text, d->content.d77.textlen);
		break;

	    case DS_COMPONENT:
		DUMPINT(d, content.d80.stream_content);
		DUMPINT(d, content.d80.reserved);
		DUMPINT(d, content.d80.type);
		DUMPINT(d, content.d80.tag);
		DUMPNSTR(d, content.d80.lang, 3);
		if (d->content.d80.textlen)
			DUMPHEX(d, content.d80.text, d->content.d80.textlen);
		break;

	    case DS_USER_DEFINED:
		DUMPINT(d, content.d137.textlen);
		DUMPNSTR(d, content.d137.lang, 3);
		DUMPHEX(d, content.d137.text, d->content.d137.textlen);
		DUMPHEX(d, content.d137.warning, d->content.d137.warninglen);
		break;

	    case DS_CONTENT_IDENTIFIER:
		DUMPINT(d, content.d118.location);
		DUMPINT(d, content.d118.type);
		DUMPINT(d, content.d118.cridlen);
		if (d->content.d118.cridlen)
			DUMPHEX(d, content.d118.crid, d->content.d118.cridlen);
		DUMPINT(d, content.d118.ref);
		break;

	    default:
		if (d->content.unknown.textlen)
			DUMPHEX(d, content.unknown.text,
			    d->content.unknown.textlen);
		break;
	}
}