// SPDX-License-Identifier: GPL-2.0-only
#include "bpftool_helpers.h"
#include <unistd.h>
#include <string.h>
#include <stdbool.h>

#define BPFTOOL_PATH_MAX_LEN		64
#define BPFTOOL_FULL_CMD_MAX_LEN	512

#define BPFTOOL_DEFAULT_PATH		"tools/sbin/bpftool"

static int detect_bpftool_path(char *buffer)
{
	char tmp[BPFTOOL_PATH_MAX_LEN];

	/* Check default bpftool location (will work if we are running the
	 * default flavor of test_progs)
	 */
	snprintf(tmp, BPFTOOL_PATH_MAX_LEN, "./%s", BPFTOOL_DEFAULT_PATH);
	if (access(tmp, X_OK) == 0) {
		strncpy(buffer, tmp, BPFTOOL_PATH_MAX_LEN);
		return 0;
	}

	/* Check alternate bpftool location (will work if we are running a
	 * specific flavor of test_progs, e.g. cpuv4 or no_alu32)
	 */
	snprintf(tmp, BPFTOOL_PATH_MAX_LEN, "../%s", BPFTOOL_DEFAULT_PATH);
	if (access(tmp, X_OK) == 0) {
		strncpy(buffer, tmp, BPFTOOL_PATH_MAX_LEN);
		return 0;
	}

	/* Failed to find bpftool binary */
	return 1;
}

static int run_command(char *args, char *output_buf, size_t output_max_len)
{
	static char bpftool_path[BPFTOOL_PATH_MAX_LEN] = {0};
	bool suppress_output = !(output_buf && output_max_len);
	char command[BPFTOOL_FULL_CMD_MAX_LEN];
	FILE *f;
	int ret;

	/* Detect and cache bpftool binary location */
	if (bpftool_path[0] == 0 && detect_bpftool_path(bpftool_path))
		return 1;

	ret = snprintf(command, BPFTOOL_FULL_CMD_MAX_LEN, "%s %s%s",
		       bpftool_path, args,
		       suppress_output ? " > /dev/null 2>&1" : "");

	f = popen(command, "r");
	if (!f)
		return 1;

	if (!suppress_output)
		fread(output_buf, 1, output_max_len, f);
	ret = pclose(f);

	return ret;
}

int run_bpftool_command(char *args)
{
	return run_command(args, NULL, 0);
}

int get_bpftool_command_output(char *args, char *output_buf, size_t output_max_len)
{
	return run_command(args, output_buf, output_max_len);
}