/* (C) 2012 by Harald Welte <laforge@gnumonks.org>
 *
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */


#include <string.h>
#include <errno.h>

#include <osmocom/core/talloc.h>
#include <osmocom/core/utils.h>
#include "auc.h"

/*
# imsi,algo,ki,0,0,0,0
# imsi,algo,k,opc,amf,sqn,opc_is_op
2620301,1,000102030405060708090a0b0c0d0e0f,0,0,0,0
2620301,1,000102030405060708090a0b0c0d0e0f,0f0e0d0c0b0a09080706050403020100,0001,32,0
*/

static struct auc_rec *
auc_rec_from_csv(void *ctx, const char *line_orig, long offset_nextline)
{
	char *line = talloc_strdup(ctx, line_orig);
	char *tok;
	struct auc_rec *rec;

	if (!line)
		return NULL;

	rec = talloc_zero(ctx, struct auc_rec);
	if (!rec) {
		talloc_free(line);
		return NULL;
	}

	/* IMSI */
	tok = strtok(line, ",");
	if (!tok)
		goto ret_free;
	strncpy(rec->imsi, tok, OSMO_MIN(strlen(tok), sizeof(rec->imsi)));
	rec->imsi[sizeof(rec->imsi)-1] = '\0';

	/* ALGO */
	tok = strtok(NULL, ",");
	if (!tok)
		goto ret_free;
	rec->auth.algo = atoi(tok);
	if (rec->auth.algo > _OSMO_AUTH_ALG_NUM)
		goto ret_free;

	/* K / Ki */
	tok = strtok(NULL, ",");
	if (!tok)
		goto ret_free;

	switch (rec->auth.algo) {
	case OSMO_AUTH_ALG_NONE:

		break;
	case OSMO_AUTH_ALG_COMP128v1:
	case OSMO_AUTH_ALG_COMP128v2:
	case OSMO_AUTH_ALG_COMP128v3:
		osmo_hexparse(tok, rec->auth.u.gsm.ki,
				sizeof(rec->auth.u.gsm.ki));
		break;
	case OSMO_AUTH_ALG_XOR:
	case OSMO_AUTH_ALG_MILENAGE:
		osmo_hexparse(tok, rec->auth.u.umts.k,
				sizeof(rec->auth.u.umts.k));
		/* OPC */
		tok = strtok(NULL, ",");
		if (!tok)
			goto ret_free;
		osmo_hexparse(tok, rec->auth.u.umts.opc,
				sizeof(rec->auth.u.umts.opc));
		/* AMF */
		tok = strtok(NULL, ",");
		if (!tok)
			goto ret_free;
		osmo_hexparse(tok, rec->auth.u.umts.amf,
				sizeof(rec->auth.u.umts.amf));
		/* SQN */
		tok = strtok(NULL, ",");
		if (!tok)
			goto ret_free;
		rec->auth.u.umts.sqn = strtoull(tok, NULL, 10);
		if (strlen(tok) != 8)
			printf("SQN must be 8 digits wide in order to support updates\n");
		else {
			/* save file offfset for SQN so we can update it */
			rec->offset_sqn = offset_nextline - (strlen(line_orig) - (tok - line));
		}

		/* IS_OP */
		tok = strtok(NULL, ",");
		if (!tok)
			goto ret_free;
		if (tok[0] == '1')
			rec->auth.u.umts.opc_is_op = 1;
		break;
	}

	talloc_free(line);

	return rec;

ret_free:
	talloc_free(rec);
	talloc_free(line);
	return NULL;
}

static char *auc_rec_to_csv(void *ctx, const struct auc_rec *rec)
{
	char *line = talloc_zero_size(ctx, 256);
	char *cur = line;
	int i;

	if (!line)
		return NULL;

	i = sprintf("%s,%u,", rec->imsi, rec->auth.algo);
	if (i < 0)
		goto ret_free;
	cur += i;

	switch (rec->auth.algo) {
	case OSMO_AUTH_ALG_NONE:
		break;
	case OSMO_AUTH_ALG_COMP128v1:
	case OSMO_AUTH_ALG_COMP128v2:
	case OSMO_AUTH_ALG_COMP128v3:
		i = sprintf(cur, "%s,0,0,0,0",
			    osmo_hexdump_nospc(rec->auth.u.gsm.ki,
					       sizeof(rec->auth.u.gsm.ki)));
		if (i < 0)
			goto ret_free;
		cur += i;
		break;
	case OSMO_AUTH_ALG_XOR:
	case OSMO_AUTH_ALG_MILENAGE:
		i = sprintf(cur, "%s,",
			    osmo_hexdump_nospc(rec->auth.u.umts.k,
				    	       sizeof(rec->auth.u.umts.k)));
		if (i < 0)
			goto ret_free;
		cur += i;

		i = sprintf(cur, "%s,",
			    osmo_hexdump_nospc(rec->auth.u.umts.opc,
				    	       sizeof(rec->auth.u.umts.opc)));
		if (i < 0)
			goto ret_free;
		cur += i;

		i = sprintf(cur, "%s,",
			    osmo_hexdump_nospc(rec->auth.u.umts.amf,
				    	       sizeof(rec->auth.u.umts.amf)));
		if (i < 0)
			goto ret_free;
		cur += i;

		i = sprintf(cur, "%llu,%u", rec->auth.u.umts.sqn,
			    rec->auth.u.umts.opc_is_op);
		if (i < 0)
			goto ret_free;
		cur += i;
		break;
	}

	return line;

ret_free:
	talloc_free(line);
	return NULL;
}

int auc_storage_read(void *ctx, const char *fname)
{
	FILE *file = fopen(fname, "r");
	char *line = talloc_zero_size(ctx, 256);
	int rc, num = 0;

	while ((line = fgets(line, 256, file))) {
		struct auc_rec *rec;
		long offset_nextline;

		if (line[0] == '#')
			continue;

		offset_nextline = ftell(file);

		rec = auc_rec_from_csv(ctx, line, offset_nextline);
		if (!rec)
			continue;

		rc = auc_add_rec(rec);
		if (rc == 0)
			num++;
	}

	return num;
}

static int auc_rec_dump(void *priv, void *ctx,
			const struct auc_rec *rec)
{
	FILE *file = priv;
	char *line;
	int rc;

	line = auc_rec_to_csv(ctx, rec);
	if (!line)
		return -EIO;

	rc = fputs(line, file);

	talloc_free(line);

	return rc;
}