/*
 * Copyright 2016-2017, Intel Corporation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 *     * Neither the name of the copyright holder nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * rpmem_common.c -- common definitions for librpmem and rpmemd
 */

#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/tcp.h>

#include "rpmem_common.h"
#include "rpmem_proto.h"
#include "rpmem_common_log.h"
#include "os.h"

unsigned Rpmem_max_nlanes = UINT_MAX;

/*
 * If set, indicates libfabric does not support fork() and consecutive calls to
 * rpmem_create/rpmem_open must fail.
 */
int Rpmem_fork_unsafe;

/*
 * rpmem_xwrite -- send entire buffer or fail
 *
 * Returns 1 if send returned 0.
 */
int
rpmem_xwrite(int fd, const void *buf, size_t len, int flags)
{
	size_t wr = 0;
	const uint8_t *cbuf = buf;
	while (wr < len) {
		ssize_t sret;
		if (!flags)
			sret = write(fd, &cbuf[wr], len - wr);
		else
			sret = send(fd, &cbuf[wr], len - wr, flags);

		if (sret == 0)
			return 1;

		if (sret < 0)
			return (int)sret;

		wr += (size_t)sret;
	}

	return 0;
}

/*
 * rpmem_xread -- read entire buffer or fail
 *
 * Returns 1 if recv returned 0.
 */
int
rpmem_xread(int fd, void *buf, size_t len, int flags)
{
	size_t rd = 0;
	uint8_t *cbuf = buf;
	while (rd < len) {
		ssize_t sret;

		if (!flags)
			sret = read(fd, &cbuf[rd], len - rd);
		else
			sret = recv(fd, &cbuf[rd], len - rd, flags);

		if (sret == 0) {
			RPMEMC_DBG(ERR, "recv/read returned 0");
			return 1;
		}

		if (sret < 0)
			return (int)sret;

		rd += (size_t)sret;
	}

	return 0;
}

static const char *pm2str[MAX_RPMEM_PM] = {
	[RPMEM_PM_APM] = "Appliance Persistency Method",
	[RPMEM_PM_GPSPM] = "General Purpose Server Persistency Method",
};

/*
 * rpmem_persist_method_to_str -- convert enum rpmem_persist_method to string
 */
const char *
rpmem_persist_method_to_str(enum rpmem_persist_method pm)
{
	if (pm >= MAX_RPMEM_PM)
		return NULL;

	return pm2str[pm];
}

static const char *provider2str[MAX_RPMEM_PROV] = {
	[RPMEM_PROV_LIBFABRIC_VERBS] = "verbs",
	[RPMEM_PROV_LIBFABRIC_SOCKETS] = "sockets",
};

/*
 * rpmem_provider_from_str -- convert string to enum rpmem_provider
 *
 * Returns RPMEM_PROV_UNKNOWN if provider is not known.
 */
enum rpmem_provider
rpmem_provider_from_str(const char *str)
{
	for (enum rpmem_provider p = 0; p < MAX_RPMEM_PROV; p++) {
		if (provider2str[p] && strcmp(str, provider2str[p]) == 0)
			return p;
	}

	return RPMEM_PROV_UNKNOWN;
}

/*
 * rpmem_provider_to_str -- convert enum rpmem_provider to string
 */
const char *
rpmem_provider_to_str(enum rpmem_provider provider)
{
	if (provider >= MAX_RPMEM_PROV)
		return NULL;

	return provider2str[provider];
}

/*
 * rpmem_get_ip_str -- converts socket address to string
 */
const char *
rpmem_get_ip_str(const struct sockaddr *addr)
{
	static char str[INET6_ADDRSTRLEN + NI_MAXSERV + 1];
	char ip[INET6_ADDRSTRLEN];
	struct sockaddr_in *in4;
	struct sockaddr_in6 *in6;

	switch (addr->sa_family) {
	case AF_INET:
		in4 = (struct sockaddr_in *)addr;
		if (!inet_ntop(AF_INET, &in4->sin_addr, ip, sizeof(ip)))
			return NULL;
		if (snprintf(str, sizeof(str), "%s:%u",
				ip, ntohs(in4->sin_port)) < 0)
			return NULL;
		break;
	case AF_INET6:
		in6 = (struct sockaddr_in6 *)addr;
		if (!inet_ntop(AF_INET6, &in6->sin6_addr, ip, sizeof(ip)))
			return NULL;
		if (snprintf(str, sizeof(str), "%s:%u",
				ip, ntohs(in6->sin6_port)) < 0)
			return NULL;
		break;
	default:
		return NULL;
	}

	return str;
}

/*
 * rpmem_target_parse -- parse target info
 */
struct rpmem_target_info *
rpmem_target_parse(const char *target)
{
	struct rpmem_target_info *info = calloc(1, sizeof(*info));
	if (!info)
		return NULL;

	char *str = strdup(target);
	if (!str)
		goto err_strdup;

	char *tmp = strchr(str, '@');
	if (tmp) {
		*tmp = '\0';
		info->flags |= RPMEM_HAS_USER;
		strncpy(info->user, str, sizeof(info->user) - 1);
		tmp++;
	} else {
		tmp = str;
	}

	if (*tmp == '[') {
		tmp++;
		/* IPv6 */
		char *end = strchr(tmp, ']');
		if (!end) {
			errno = EINVAL;
			goto err_ipv6;
		}

		*end = '\0';
		strncpy(info->node, tmp, sizeof(info->node) - 1);
		tmp = end + 1;

		end = strchr(tmp, ':');
		if (end) {
			*end = '\0';
			end++;
			info->flags |= RPMEM_HAS_SERVICE;
			strncpy(info->service, end, sizeof(info->service) - 1);
		}
	} else {
		char *first = strchr(tmp, ':');
		char *last = strrchr(tmp, ':');
		if (first == last) {
			/* IPv4 - one colon */
			if (first) {
				*first = '\0';
				first++;
				info->flags |= RPMEM_HAS_SERVICE;
				strncpy(info->service, first,
						sizeof(info->service) - 1);
			}
		}

		strncpy(info->node, tmp, sizeof(info->node) - 1);
	}

	if (*info->node == '\0') {
		errno = EINVAL;
		goto err_node;
	}

	free(str);

	/* make sure that user, node and service are NULL-terminated */
	info->user[sizeof(info->user) - 1] = '\0';
	info->node[sizeof(info->node) - 1] = '\0';
	info->service[sizeof(info->service) - 1] = '\0';

	return info;
err_node:
err_ipv6:
	free(str);
err_strdup:
	free(info);
	return NULL;
}

/*
 * rpmem_target_free -- free target info
 */
void
rpmem_target_free(struct rpmem_target_info *info)
{
	free(info);
}

/*
 * rpmem_get_ssh_conn_addr -- returns an address which the ssh connection is
 * established on
 *
 * This function utilizes the SSH_CONNECTION environment variable to retrieve
 * the server IP address. See ssh(1) for details.
 */
char *
rpmem_get_ssh_conn_addr(void)
{
	char *ssh_conn = os_getenv("SSH_CONNECTION");
	if (!ssh_conn) {
		RPMEMC_LOG(ERR, "SSH_CONNECTION variable is not set");
		return NULL;
	}

	char *sp = strchr(ssh_conn, ' ');
	if (!sp)
		goto err_fmt;

	char *addr = strchr(sp + 1, ' ');
	if (!addr)
		goto err_fmt;

	addr++;

	sp = strchr(addr, ' ');
	if (!sp)
		goto err_fmt;

	*sp = '\0';

	return addr;
err_fmt:
	RPMEMC_LOG(ERR, "invalid format of SSH_CONNECTION variable");
	return NULL;
}