/*
 * net helpers
 *
 * Copyright (C) 2010 Mike Christie
 * Copyright (C) 2010 Red Hat, Inc. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 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
 * General Public License for more details.
 */
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <net/if.h>
#include <unistd.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/route.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/sockios.h>
#include <linux/if_vlan.h>
#include <net/if_arp.h>
#include <linux/if_ether.h>

#include "sysdeps.h"
#include "ethtool-copy.h"
#include "iscsi_net_util.h"
#include "log.h"

struct iscsi_net_driver {
	const char *net_drv_name;
	const char *iscsi_transport;
};

static struct iscsi_net_driver net_drivers[] = {
	{"cxgb3", "cxgb3i" },
	{"cxgb4", "cxgb4i" },
	{"bnx2", "bnx2i" },
	{"bnx2x", "bnx2i"},
	{NULL, NULL}
};

/**
 * net_get_transport_name_from_netdev - get name of transport to use for iface
 * @netdev: netdev iface name
 * @transport: buffer to hold transport name
 *
 * transport buffer should be ISCSI_TRANSPORT_NAME_MAXLEN bytes
 */
int net_get_transport_name_from_netdev(char *netdev, char *transport)
{
	struct ethtool_drvinfo drvinfo;
	struct ifreq ifr;
	int err, fd, i;

	memset(&ifr, 0, sizeof(ifr));
	strcpy(ifr.ifr_name, netdev);

	fd = socket(AF_INET, SOCK_DGRAM, 0);
	if (fd < 0) {
		log_error("Could not open socket for ioctl.");
		return errno;
	}

	drvinfo.cmd = ETHTOOL_GDRVINFO;
	ifr.ifr_data = (caddr_t)&drvinfo;
	err = ioctl(fd, SIOCETHTOOL, &ifr);
	if (err < 0) {
		log_error("Could not get driver %s.", netdev);
		err = errno;
		goto close_sock;
	}

	/*
	* iSCSI hardware offload for bnx2{,x} is only supported if the
	* iscsiuio executable is available.
	*/
	if (!strcmp(drvinfo.driver, "bnx2x") ||
	    !strcmp(drvinfo.driver, "bnx2")) {
		struct stat buf;

		if (stat(ISCSIUIO_PATH, &buf)) {
			log_debug(1, "ISCSI offload not supported "
			             "(%s not found).", ISCSIUIO_PATH);
			err = ENODEV;
			goto close_sock;
			}
	}

	for (i = 0; net_drivers[i].net_drv_name != NULL; i++) {
		struct iscsi_net_driver *net_driver = &net_drivers[i];

		if (!strcmp(net_driver->net_drv_name, drvinfo.driver)) {
			strcpy(transport, net_driver->iscsi_transport);
			err = 0;
			goto close_sock;
		}
	}
	err = ENODEV;

close_sock:
	close(fd);
	return err;
}

/**
 * net_get_netdev_from_hwaddress - given a hwaddress return the ethX
 * @hwaddress: hw address no larger than ISCSI_HWADDRESS_BUF_SIZE
 * @netdev: buffer of IFNAMSIZ size that will hold the ethX
 *
 * Does not support interfaces like a bond or alias because
 * multiple interfaces will have the same hwaddress.
 */
int net_get_netdev_from_hwaddress(char *hwaddress, char *netdev)
{
	struct if_nameindex *ifni;
	struct ifreq if_hwaddr;
	int found = 0, sockfd, i = 0;
	unsigned char *hwaddr;
	char tmp_hwaddress[ISCSI_HWADDRESS_BUF_SIZE];

	ifni = if_nameindex();
	if (ifni == NULL) {
		log_error("Could not match hwaddress %s to netdev. "
			  "getifaddrs failed %d", hwaddress, errno);
		return errno;
	}

	/* Open a basic socket. */
	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (sockfd < 0) {
		log_error("Could not open socket for ioctl.");
		goto free_ifni;
	}

	for (i = 0; ifni[i].if_index && ifni[i].if_name; i++) {
		struct if_nameindex *n = &ifni[i];

		strlcpy(if_hwaddr.ifr_name, n->if_name, IFNAMSIZ);
		if (ioctl(sockfd, SIOCGIFHWADDR, &if_hwaddr) < 0) {
			log_error("Could not match %s to netdevice.",
				  hwaddress);
			continue;
		}

		/* check for ARPHRD_ETHER (ethernet) */
		if (if_hwaddr.ifr_hwaddr.sa_family != 1)
			continue;
		hwaddr = (unsigned char *)if_hwaddr.ifr_hwaddr.sa_data;

		memset(tmp_hwaddress, 0, ISCSI_HWADDRESS_BUF_SIZE);
		/* TODO should look and covert so we do not need tmp buf */
		sprintf(tmp_hwaddress, "%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x",
			hwaddr[0], hwaddr[1], hwaddr[2], hwaddr[3],
			hwaddr[4], hwaddr[5]);
		log_debug(4, "Found hardware address %s", tmp_hwaddress);
		if (!strcasecmp(tmp_hwaddress, hwaddress)) {
			log_debug(4, "Matches %s to %s", hwaddress,
				  n->if_name);
			memset(netdev, 0, IFNAMSIZ); 
			strlcpy(netdev, n->if_name, IFNAMSIZ);
			found = 1;
			break;
		}
	}

	close(sockfd);
free_ifni:
	if_freenameindex(ifni);
	if (!found)
		return ENODEV;
	return 0;
}

static char *find_vlan_dev(char *netdev, int vlan_id) {
	struct ifreq if_hwaddr;
	struct ifreq vlan_hwaddr;
	struct vlan_ioctl_args vlanrq = { .cmd = GET_VLAN_VID_CMD, };
	struct if_nameindex *ifni;
	char *vlan = NULL;
	int sockfd, i, rc;

	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (sockfd < 0) {
		log_error("Could not open socket for ioctl.");
		return NULL;
	}

	strlcpy(if_hwaddr.ifr_name, netdev, IFNAMSIZ);
	ioctl(sockfd, SIOCGIFHWADDR, &if_hwaddr);

	if (if_hwaddr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
		close(sockfd);
		return NULL;
	}

	ifni = if_nameindex();
	for (i = 0; ifni[i].if_index && ifni[i].if_name; i++) {
		strlcpy(vlan_hwaddr.ifr_name, ifni[i].if_name, IFNAMSIZ);
		ioctl(sockfd, SIOCGIFHWADDR, &vlan_hwaddr);

		if (vlan_hwaddr.ifr_hwaddr.sa_family != ARPHRD_ETHER)
			continue;

		if (!memcmp(if_hwaddr.ifr_hwaddr.sa_data, vlan_hwaddr.ifr_hwaddr.sa_data, ETH_ALEN)) {
			strlcpy(vlanrq.device1, ifni[i].if_name, IFNAMSIZ);
			rc = ioctl(sockfd, SIOCGIFVLAN, &vlanrq);
			if ((rc == 0) && (vlanrq.u.VID == vlan_id)) {
				vlan = strdup(vlanrq.device1);
				break;
			}
		}
	}
	if_freenameindex(ifni);

	close(sockfd);
	return vlan;
}

/**
 * net_setup_netdev - bring up NIC
 * @netdev: network device name
 * @local: ip address for netdev
 * @mask: net mask
 * @gateway: gateway
 * @remote_ip: target portal ip
 * @needs_bringup: bool indicating if the netdev needs to be started
 *
 * Bring up required NIC and use routing
 * to force iSCSI traffic through correct NIC.
 */
int net_setup_netdev(char *netdev, char *local_ip, char *mask, char *gateway,
		     char *vlan, char *remote_ip, int needs_bringup)
{
	struct sockaddr_in sk_ipaddr = { .sin_family = AF_INET };
	struct sockaddr_in sk_netmask = { .sin_family = AF_INET };
	struct sockaddr_in sk_hostmask = { .sin_family = AF_INET };
	struct sockaddr_in sk_gateway = { .sin_family = AF_INET };
	struct sockaddr_in sk_tgt_ipaddr = { .sin_family = AF_INET };
	struct rtentry rt;
	struct ifreq ifr;
	char *physdev = NULL;
	int sock;
	int ret;
	int vlan_id;

	if (!strlen(netdev)) {
		log_error("No netdev name in fw entry.");
		return EINVAL;
	}		

	vlan_id = atoi(vlan);

	if (vlan_id != 0) {
		physdev = netdev;
		netdev = find_vlan_dev(physdev, vlan_id);
	}

	if (vlan_id && !netdev) {
		/* TODO: create vlan if not found */
		log_error("No matching vlan found for fw entry.");
		return EINVAL;
	}

	/* Create socket for making networking changes */
	if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
		log_error("Could not open socket to manage network "
			  "(err %d - %s)", errno, strerror(errno));
		ret = errno;
		goto done;
	}

	/* Bring up NIC with correct address  - unless it
	 * has already been handled (2 targets in IBFT may share one NIC)
	 */
	if (!inet_aton(local_ip, &sk_ipaddr.sin_addr)) {
		log_error("Invalid or missing ipaddr in fw entry");
		ret = EINVAL;
		goto done;
	}

	if (!inet_aton(mask, &sk_netmask.sin_addr)) {
		log_error("Invalid or missing netmask in fw entry");
		ret = EINVAL;
		goto done;
	}

	inet_aton("255.255.255.255", &sk_hostmask.sin_addr);

	if (!inet_aton(remote_ip, &sk_tgt_ipaddr.sin_addr)) {
		log_error("Invalid or missing target ipaddr in fw entry");
		ret = EINVAL;
		goto done;
	}

	/* Only set IP/NM if this is a new interface */
	if (needs_bringup) {

		if (physdev) {
			/* Bring up interface */
			memset(&ifr, 0, sizeof(ifr));
			strlcpy(ifr.ifr_name, physdev, IFNAMSIZ);
			ifr.ifr_flags = IFF_UP | IFF_RUNNING;
			if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
				log_error("Could not bring up netdev %s (err %d - %s)",
					  physdev, errno, strerror(errno));
				ret = errno;
				goto done;
			}
		}

		/* Bring up interface */
		memset(&ifr, 0, sizeof(ifr));
		strlcpy(ifr.ifr_name, netdev, IFNAMSIZ);
		ifr.ifr_flags = IFF_UP | IFF_RUNNING;
		if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
			log_error("Could not bring up netdev %s (err %d - %s)",
				  netdev, errno, strerror(errno));
			ret = errno;
			goto done;
		}
		/* Set IP address */
		memset(&ifr, 0, sizeof(ifr));
		strlcpy(ifr.ifr_name, netdev, IFNAMSIZ);
		memcpy(&ifr.ifr_addr, &sk_ipaddr, sizeof(struct sockaddr));
		if (ioctl(sock, SIOCSIFADDR, &ifr) < 0) {
			log_error("Could not set ip for %s (err %d - %s)",
				  netdev, errno, strerror(errno));
			ret = errno;
			goto done;
		}

		/* Set netmask */
		memset(&ifr, 0, sizeof(ifr));
		strlcpy(ifr.ifr_name, netdev, IFNAMSIZ);
		memcpy(&ifr.ifr_addr, &sk_netmask, sizeof(struct sockaddr));
		if (ioctl(sock, SIOCSIFNETMASK, &ifr) < 0) {
			log_error("Could not set ip for %s (err %d - %s)",
				  netdev, errno, strerror(errno));
			ret = errno;
			goto done;
		}
	}

	/* Set static route to target via this interface */
	memset((char *) &rt, 0, sizeof(rt));
	memcpy(&rt.rt_dst, &sk_tgt_ipaddr, sizeof(sk_tgt_ipaddr));
	memcpy(&rt.rt_genmask, &sk_hostmask, sizeof(sk_hostmask));
	rt.rt_flags = RTF_UP | RTF_HOST;
	rt.rt_dev = netdev;

	if ((sk_tgt_ipaddr.sin_addr.s_addr & sk_netmask.sin_addr.s_addr) == 
		(sk_ipaddr.sin_addr.s_addr & sk_netmask.sin_addr.s_addr)) {
		/* Same subnet */
		if (ioctl(sock, SIOCADDRT, &rt) < 0) {
			if (errno != EEXIST) {
				log_error("Could not set ip for %s "
					  "(err %d - %s)", netdev,
					   errno, strerror(errno));
				ret = errno;
				goto done;
			}
		}
	} else {
		/* Different subnet.  Use gateway */
		rt.rt_flags |= RTF_GATEWAY;
		if (!inet_aton(gateway, &sk_gateway.sin_addr)) {
			log_error("Invalid or missing gateway for %s "
				  "(err %d - %s)",
				  netdev, errno, strerror(errno));
			ret = errno;
			goto done;
		}
		memcpy(&rt.rt_gateway, &sk_gateway, sizeof(sk_gateway));
		if (ioctl(sock, SIOCADDRT, &rt) < 0) {
			if (errno != EEXIST) {
				log_error("Could not set gateway for %s "
					  "(err %d - %s)", netdev,
					  errno, strerror(errno));
				ret = errno;
				goto done;
			}
		}
	}
	ret = 0;

done:
	if (sock >= 0)
		close(sock);
	if (vlan_id)
		free(netdev);
	return ret;
}

/**
 * net_ifup_netdev - bring up network interface
 * @netdev: netdevice to bring up.
 */
int net_ifup_netdev(char *netdev)
{
	struct ifreq ifr;
	int sock;
	int ret = 0;

	if (!strlen(netdev)) {
		log_error("No netdev name in fw entry.");
		return EINVAL;
	}		

	/* Create socket for making networking changes */
	if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
		log_error("Could not open socket to manage network "
			  "(err %d - %s)", errno, strerror(errno));
		return errno;
	}

	memset(&ifr, 0, sizeof(ifr));
	strlcpy(ifr.ifr_name, netdev, IFNAMSIZ);
	if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
		log_error("Could not bring up netdev %s (err %d - %s)",
			  netdev, errno, strerror(errno));
		ret = errno;
		goto done;
	}

	if (ifr.ifr_flags & IFF_UP) {
		log_debug(3, "%s up", netdev);
		goto done;
	}

	log_debug(3, "bringing %s up", netdev);

	/* Bring up interface */
	memset(&ifr, 0, sizeof(ifr));
	strlcpy(ifr.ifr_name, netdev, IFNAMSIZ);
	ifr.ifr_flags = IFF_UP;
	if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
		log_error("Could not bring up netdev %s (err %d - %s)",
			  netdev, errno, strerror(errno));
		ret = errno;
		goto done;
	}
done:
	close(sock);
	return ret;
}