/*
 * This libprint module (one public function plus many internal subfunctions)
 * implements printing/formatting of GPF TST interface packets, which can be
 * traces, sysprims, protocol stack primitives or unrecognized packet format.
 */

#include <sys/types.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>

static int
basic_checks(rxpkt, rxpkt_len)
	u_char *rxpkt;
	unsigned rxpkt_len;
{
	int i, c;

	if (rxpkt_len < 17)
		return(0);
	/* check version bits in the header byte */
	if ((rxpkt[1] & 0xC0) != 0x80)
		return(0);
	/* check the length */
	c = rxpkt[2] | rxpkt[3] << 8;
	if (c + 4 != rxpkt_len)
		return(0);
	/* ensure that the "from" and "to" are printable ASCII */
	for (i = 8; i < 16; i++) {
		c = rxpkt[i];
		if (c < ' ' || c > '~')
			return(0);
	}
	/* basic checks pass */
	return(1);
}

static int
psprim_extra_checks(rxpkt, rxpkt_len)
	u_char *rxpkt;
	unsigned rxpkt_len;
{
	int i, c;

	if (rxpkt_len < 24)
		return(0);
	/* "original rcvr" field needs to be printable ASCII */
	for (i = 16; i < 20; i++) {
		c = rxpkt[i];
		if (c < ' ' || c > '~')
			return(0);
	}
	/* checks pass */
	return(1);
}

static void
print_malformed(rxpkt, rxpkt_len, extra_prefix, outfunc_head, outfunc_cont)
	u_char *rxpkt;
	unsigned rxpkt_len;
	char *extra_prefix;
	void (*outfunc_head)(), (*outfunc_cont)();
{
	char headline[80];

	sprintf(headline, "%sGPF unrecognized packet format", extra_prefix);
	outfunc_head(headline);
	packet_hex_dump(rxpkt, rxpkt_len, outfunc_cont);
}

static void
print_malloc_fail(rxpkt, rxpkt_len, extra_prefix, outfunc_head, outfunc_cont)
	u_char *rxpkt;
	unsigned rxpkt_len;
	char *extra_prefix;
	void (*outfunc_head)(), (*outfunc_cont)();
{
	char headline[80];

	sprintf(headline, "%sGPF packet, failed malloc in formatting",
		extra_prefix);
	outfunc_head(headline);
	packet_hex_dump(rxpkt, rxpkt_len, outfunc_cont);
}

static int
entity_name_well_formed(p)
	char *p;
{
	int i, len;

	if (!isupper(p[0]))
		return(0);
	for (i = 0; i < 4; i++)
		if (!isalnum(p[i]))
			break;
	len = i;
	for (; i < 4; i++)
		if (p[i] != ' ')
			return(0);
	return(len);
}

static void
print_entity_name(raw, outp)
	char *raw, **outp;
{
	int len;

	len = entity_name_well_formed(raw);
	if (len) {
		sprintf(*outp, "%.*s", len, raw);
		*outp += len;
	} else {
		sprintf(*outp, "\"%.4s\"", raw);
		*outp += 6;
	}
}

static void
print_common_hdr(rxpkt, outp, typestr, extra_prefix)
	u_char *rxpkt;
	char **outp, *typestr, *extra_prefix;
{
	sprintf(*outp, "%sGPF %s id=%02X ts=%02X%02X%02X%02X ", extra_prefix,
		typestr, rxpkt[1], rxpkt[7], rxpkt[6], rxpkt[5], rxpkt[4]);
	*outp = index(*outp, '\0');
	print_entity_name(rxpkt + 8, outp);
	*(*outp)++ = '-';
	*(*outp)++ = '>';
	print_entity_name(rxpkt + 12, outp);
	*(*outp)++ = ' ';
}

static void
format_text(rxpkt, rxpkt_len, start_off, outp)
	u_char *rxpkt;
	unsigned rxpkt_len, start_off;
	char *outp;
{
	*outp++ = '\"';
	safe_print_trace(rxpkt + start_off, rxpkt_len - start_off, outp);
	outp = index(outp, '\0');
	*outp++ = '\"';
	*outp = '\0';
}

static void
format_compressed_trace(rxpkt, rxpkt_len, start_off, outp)
	u_char *rxpkt;
	unsigned rxpkt_len, start_off;
	char *outp;
{
	int i;

	i = start_off + 1;
	sprintf(outp, "%d", rxpkt[i+1] << 8 | rxpkt[i]);
	outp = index(outp, '\0');
	i += 4;
	for (; i < rxpkt_len; i++) {
		sprintf(outp, " %02X", rxpkt[i]);
		outp += 3;
	}
	*outp = '\0';
}

static void
format_trace(rxpkt, rxpkt_len, extra_prefix, outfunc_head, outfunc_cont)
	u_char *rxpkt;
	unsigned rxpkt_len;
	char *extra_prefix;
	void (*outfunc_head)(), (*outfunc_cont)();
{
	char *outbuf, *outp;
	int i;

	outbuf = malloc(rxpkt_len * 4 + strlen(extra_prefix) + 1);
	if (!outbuf) {
		print_malloc_fail(rxpkt, rxpkt_len, extra_prefix, outfunc_head,
				  outfunc_cont);
		return;
	}
	outp = outbuf;
	print_common_hdr(rxpkt, &outp, "trace", extra_prefix);
	i = 16;
	if (rxpkt[i] < 0x20) {
		sprintf(outp, "tc=%02X ", rxpkt[i]);
		outp += 6;
		i++;
	}
	if (rxpkt_len - i >= 5 && rxpkt[i] == '%' &&
	    !rxpkt[i+3] && !rxpkt[i+4])
		format_compressed_trace(rxpkt, rxpkt_len, i, outp);
	else
		format_text(rxpkt, rxpkt_len, i, outp);
	outfunc_head(outbuf);
	free(outbuf);
}

static void
format_sysprim(rxpkt, rxpkt_len, extra_prefix, outfunc_head, outfunc_cont)
	u_char *rxpkt;
	unsigned rxpkt_len;
	char *extra_prefix;
	void (*outfunc_head)(), (*outfunc_cont)();
{
	char *outbuf, *outp;

	outbuf = malloc(rxpkt_len * 4 + strlen(extra_prefix) + 1);
	if (!outbuf) {
		print_malloc_fail(rxpkt, rxpkt_len, extra_prefix, outfunc_head,
				  outfunc_cont);
		return;
	}
	outp = outbuf;
	print_common_hdr(rxpkt, &outp, "sysprim", extra_prefix);
	format_text(rxpkt, rxpkt_len, 16, outp);
	outfunc_head(outbuf);
	free(outbuf);
}

static void
format_psprim(rxpkt, rxpkt_len, extra_prefix, outfunc_head, outfunc_cont)
	u_char *rxpkt;
	unsigned rxpkt_len;
	char *extra_prefix;
	void (*outfunc_head)(), (*outfunc_cont)();
{
	char headline[80];
	char *outp = headline;

	print_common_hdr(rxpkt, &outp, "PSprim", extra_prefix);
	/* original destination */
	*outp++ = '(';
	print_entity_name(rxpkt + 16, &outp);
	*outp++ = ')';
	/* opcode and data length */
	sprintf(outp, " %02X%02X%02X%02X len=%u",
		rxpkt[23], rxpkt[22], rxpkt[21], rxpkt[20], rxpkt_len - 24);
	outfunc_head(headline);
	packet_hex_dump(rxpkt + 24, rxpkt_len - 24, outfunc_cont);
}

void
format_gpf_packet(rxpkt, rxpkt_len, extra_prefix, outfunc_head, outfunc_cont)
	u_char *rxpkt;
	unsigned rxpkt_len;
	char *extra_prefix;
	void (*outfunc_head)(), (*outfunc_cont)();
{
	if (!basic_checks(rxpkt, rxpkt_len)) {
		print_malformed(rxpkt, rxpkt_len, extra_prefix, outfunc_head,
				outfunc_cont);
		return;
	}
	/* dispatch by type */
	switch (rxpkt[1] & 0x30) {
	case 0x10:
		/* PS primitive */
		if (psprim_extra_checks(rxpkt, rxpkt_len))
			format_psprim(rxpkt, rxpkt_len, extra_prefix,
					outfunc_head, outfunc_cont);
		else
			print_malformed(rxpkt, rxpkt_len, extra_prefix,
					outfunc_head, outfunc_cont);
		return;
	case 0x20:
		/* trace */
		format_trace(rxpkt, rxpkt_len, extra_prefix, outfunc_head,
				outfunc_cont);
		return;
	case 0x30:
		/* system primitive */
		format_sysprim(rxpkt, rxpkt_len, extra_prefix, outfunc_head,
				outfunc_cont);
		return;
	default:
		print_malformed(rxpkt, rxpkt_len, extra_prefix, outfunc_head,
				outfunc_cont);
	}
}