#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <limits.h>
#include <errno.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <termios.h>

#include "hyper.h"
#include "util.h"
#include "../config.h"

void hyper_set_be32(uint8_t *buf, uint32_t val)
{
	buf[0] = val >> 24;
	buf[1] = val >> 16;
	buf[2] = val >> 8;
	buf[3] = val;
}

uint32_t hyper_get_be32(uint8_t *buf)
{
	return buf[0] << 24 | buf[1] << 16 | buf[2] << 8 | buf[3];
}

void hyper_set_be64(uint8_t *buf, uint64_t val)
{
	hyper_set_be32(buf, val >> 32);
	hyper_set_be32(buf + 4, val);
}

uint64_t hyper_get_be64(uint8_t *buf)
{
	uint64_t v;

	v = (uint64_t) hyper_get_be32(buf) << 32;
	v |= hyper_get_be32(buf + 4);
	return v;
}

int hyper_send_data(int fd, uint8_t *data, uint32_t len)
{
	int length = 0, size;

	while (length < len) {
		size = write(fd, data + length, len - length);

		if (size <= 0) {
			if (errno == EINTR)
				continue;
			/* EAGAIN means unblock and the peer of virtio-ports is disappear */
			if (errno == EAGAIN)
				return 0;

			perror("send hyper data failed");
			return -1;
		}
#if WITH_VBOX
		tcdrain(fd);
#endif
		length += size;
	}

	return 0;
}

int hyper_send_msg(int fd, uint32_t type, uint32_t len,
		 uint8_t *message)
{
	uint8_t buf[8];

	fprintf(stdout, "hyper send type %d, len %d\n", type, len);

	hyper_set_be32(buf, type);
	hyper_set_be32(buf + 4, len + 8);

	if (hyper_send_data(fd, buf, 8) < 0)
		return -1;

	if (message && hyper_send_data(fd, message, len) < 0)
		return -1;

	return 0;
}

int hyper_send_type(int fd, uint32_t type)
{
	return hyper_send_msg(fd, type, 0, NULL);
}

int hyper_get_type(int fd, uint32_t *type)
{
	int len = 0, size;
	uint8_t buf[8];

	while (len < 8) {
		size = read(fd, buf + len, 8 - len);

		if (size <= 0) {
			if (errno == EINTR)
				continue;
			perror("wait for ack failed");
			return -1;
		}
		len += size;
	}

	*type = hyper_get_be32(buf);
	return 0;
}

int hyper_send_msg_block(int fd, uint32_t type, uint32_t len, uint8_t *data)
{
	int ret, flags;

	flags = hyper_setfd_block(fd);
	if (flags < 0) {
		fprintf(stderr, "%s fail to set fd block\n", __func__);
		return -1;
	}

	ret = hyper_send_msg(fd, type, len, data);

	if (fcntl(fd, F_SETFL, flags) < 0) {
		perror("restore fd flag failed");
		return -1;
	}

	return ret;
}

static int get_addr_ipv4(uint8_t *ap, const char *cp)
{
	int i;

	for (i = 0; i < 4; i++) {
		unsigned long n;
		char *endp;

		n = strtoul(cp, &endp, 0);
		if (n > 255)
			return -1;      /* bogus network value */

		if (endp == cp) /* no digits */
			return -1;
		ap[i] = n;

		if (*endp == '\0')
			break;

		if (i == 3 || *endp != '.')
			return -1;      /* extra characters */

		cp = endp + 1;
	}

	return 1;
}

static int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)
{
	int len = RTA_LENGTH(alen);
	struct rtattr *rta;

	if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen)
		return -1;
	rta = (struct rtattr *)(((char *)n) + NLMSG_ALIGN(n->nlmsg_len));
	rta->rta_type = type;
	rta->rta_len = len;
	memcpy(RTA_DATA(rta), data, alen);
	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
	return 0;
}

static int hyper_get_ifindex(char *nic)
{
	int fd, ifindex = -1;
	char path[512], buf[4];

	fprintf(stdout, "net device %s\n", nic);
	sprintf(path, "/sys/class/net/%s/ifindex", nic);
	fprintf(stdout, "net device sys path is %s\n", path);

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		perror("can not open file");
		return -1;
	}

	memset(buf, 0, sizeof(buf));
	if (read(fd, buf, sizeof(buf)) <= 0) {
		perror("can read open file");
		goto out;
	}

	ifindex = atoi(buf);
	fprintf(stdout, "get ifindex %d\n", ifindex);
out:
	close(fd);
	return ifindex;
}

static int netlink_open(struct rtnl_handle *rth)
{
	memset(rth, 0, sizeof(*rth));

	rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
	if (rth->fd < 0) {
		perror("cannot open netlink socket");
		return -1;
	}

	rth->local.nl_family = AF_NETLINK;
	rth->local.nl_groups = 0;

	if (bind(rth->fd, (struct sockaddr *)&rth->local, sizeof(rth->local)) < 0) {
		perror("cannot bind netlink socket");
		goto out;
	}

	rth->seq = 0;
	return 0;
out:
	close(rth->fd);
	return -1;
}

static void netlink_close(struct rtnl_handle *rth)
{
	if (rth->fd > 0)
		close(rth->fd);
	rth->fd = -1;
}

static int rtnl_talk(struct rtnl_handle *rtnl,
		     struct nlmsghdr *n, pid_t peer,
		     unsigned groups, struct nlmsghdr *answer)
{
	int status;
	struct sockaddr_nl nladdr;
	struct iovec iov = { (void *)n, n->nlmsg_len };
	struct msghdr msg = { (void *)&nladdr, sizeof(nladdr), &iov, 1, NULL, 0, 0 };

	memset(&nladdr, 0, sizeof(nladdr));
	nladdr.nl_family = AF_NETLINK;
	nladdr.nl_pid = peer;
	nladdr.nl_groups = groups;
	n->nlmsg_seq = ++rtnl->seq;
	if (answer == NULL)
		n->nlmsg_flags |= NLM_F_ACK;

	status = sendmsg(rtnl->fd, &msg, 0);
	if (status < 0)
		return -1;

	return 0;
}

static int hyper_up_nic(struct rtnl_handle *rth, int ifindex)
{
	struct {
		struct nlmsghdr n;
		struct ifinfomsg i;
		char buf[1024];
	} req;

	memset(&req, 0, sizeof(req));
	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
	req.n.nlmsg_flags = NLM_F_REQUEST;
	req.n.nlmsg_type = RTM_NEWLINK;
	req.i.ifi_family = AF_UNSPEC;
	req.i.ifi_change |= IFF_UP;
	req.i.ifi_flags |= IFF_UP;
	req.i.ifi_index = ifindex;

	if (rtnl_talk(rth, &req.n, 0, 0, NULL) < 0)
		return -1;

	return 0;
}

static int hyper_remove_nic(char *device)
{
	char path[256], real[128];
	int fd;
	ssize_t size;

	sprintf(path, "/sys/class/net/%s", device);

	size = readlink(path, real, 128);
	if (size < 0 || size > 127) {
		perror("fail to read link directory");
		return -1;
	}

	real[size] = '\0';
	sprintf(path, "/sys/%s/../../../remove", real + 5);

	fprintf(stdout, "get net sys path %s\n", path);

	fd = open(path, O_WRONLY);
	if (fd < 0) {
		perror("open file failed");
		return -1;
	}

	if (write(fd, "1\n", 2) < 0) {
		perror("write 1 to file failed");
		close(fd);
		return 1;
	}

	close(fd);
	return 0;
}

static int hyper_down_nic(struct rtnl_handle *rth, int ifindex)
{
	struct {
		struct nlmsghdr n;
		struct ifinfomsg i;
		char buf[1024];
	} req;

	memset(&req, 0, sizeof(req));
	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
	req.n.nlmsg_flags = NLM_F_REQUEST;
	req.n.nlmsg_type = RTM_NEWLINK;
	req.i.ifi_family = AF_UNSPEC;
	req.i.ifi_change |= IFF_UP;
	req.i.ifi_flags &= ~IFF_UP;
	req.i.ifi_index = ifindex;

	if (rtnl_talk(rth, &req.n, 0, 0, NULL) < 0)
		return -1;

	return 0;
}

static int mask2bits(uint32_t netmask)
{
	unsigned bits = 0;
	uint32_t mask = ntohl(netmask);
	uint32_t host = ~mask;

	/* a valid netmask must be 2^n - 1 */
	if ((host & (host + 1)) != 0)
		return -1;

	for (; mask; mask <<= 1)
		++bits;

	return bits;
}

static int get_netmask(unsigned *val, const char *addr)
{
	char *ptr;
	unsigned long res;
	uint32_t data;
	int b;

	res = strtoul(addr, &ptr, 0);

	if (!ptr || ptr == addr || *ptr)
		goto get_addr;

	if (res == ULONG_MAX && errno == ERANGE)
		goto get_addr;

	if (res > UINT_MAX)
		goto get_addr;

	*val = res;
	return 0;

get_addr:
	if (get_addr_ipv4((uint8_t *)&data, addr) <= 0)
		return -1;

	b = mask2bits(data);
	if (b < 0)
		return -1;

	*val = b;
	return 0;
}

static int hyper_setup_route(struct rtnl_handle *rth,
			   struct hyper_route *rt)
{
	uint32_t data;
	struct {
		struct nlmsghdr n;
		struct rtmsg r;
		char buf[1024];
	} req;

	if (!rt->dst) {
		fprintf(stderr, "route dest is null\n");
		return -1;
	}

	memset(&req, 0, sizeof(req));
	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
	req.n.nlmsg_flags = NLM_F_CREATE | NLM_F_EXCL | NLM_F_REQUEST;
	req.n.nlmsg_type = RTM_NEWROUTE;

	req.r.rtm_family = AF_INET;
	req.r.rtm_table = RT_TABLE_MAIN;
	req.r.rtm_scope = RT_SCOPE_UNIVERSE;
	req.r.rtm_type = RTN_UNICAST;
	req.r.rtm_protocol = RTPROT_BOOT;
	req.r.rtm_dst_len = 0;

	if (rt->gw) {
		if (get_addr_ipv4((uint8_t *)&data, rt->gw) <= 0) {
			fprintf(stderr, "get gw failed\n");
			return -1;
		}

		if (addattr_l(&req.n, sizeof(req), RTA_GATEWAY, &data, 4)) {
			fprintf(stderr, "setup gateway attr failed\n");
			return -1;
		}
	}

	if (rt->device) {
		rt->ifindex = hyper_get_ifindex(rt->device);
		if (addattr_l(&req.n, sizeof(req), RTA_OIF, &rt->ifindex, 4)) {
			fprintf(stderr, "setup oif attr failed\n");
			return -1;
		}
	}

	if (strcmp(rt->dst, "default") && strcmp(rt->dst, "any") && strcmp(rt->dst, "all")) {
		unsigned mask;
		char *slash = strchr(rt->dst, '/');

		req.r.rtm_dst_len = 32;

		if (slash)
			*slash = 0;

		if (get_addr_ipv4((uint8_t *)&data, rt->dst) <= 0) {
			fprintf(stderr, "get dst failed\n");
			return -1;
		}

		if (addattr_l(&req.n, sizeof(req), RTA_DST, &data, 4)) {
			fprintf(stderr, "setup gateway attr failed\n");
			return -1;
		}

		if (slash) {
			if (get_netmask(&mask, slash + 1) < 0) {
				fprintf(stderr, "get netmask failed\n");
				return -1;
			}
			req.r.rtm_dst_len = mask;
			*slash = '/';
		}
	}

	if (rtnl_talk(rth, &req.n, 0, 0, NULL) < 0) {
		fprintf(stderr, "rtnl talk failed\n");
		return -1;
	}

	return 0;
}

static int hyper_cleanup_route(struct rtnl_handle *rth, struct hyper_route *rt)
{
	uint32_t data;
	struct {
		struct nlmsghdr n;
		struct rtmsg r;
		char buf[1024];
	} req;

	if (!rt->dst) {
		fprintf(stderr, "route dest is null\n");
		return -1;
	}

	memset(&req, 0, sizeof(req));
	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
	req.n.nlmsg_flags = NLM_F_REQUEST;
	req.n.nlmsg_type = RTM_DELROUTE;

	req.r.rtm_family = AF_INET;
	req.r.rtm_table = RT_TABLE_MAIN;
	req.r.rtm_scope = RT_SCOPE_UNIVERSE;
	req.r.rtm_type = RTN_UNICAST;
	req.r.rtm_protocol = RTPROT_BOOT;
	req.r.rtm_dst_len = 0;

	if (rt->gw) {
		if (get_addr_ipv4((uint8_t *)&data, rt->gw) <= 0) {
			fprintf(stderr, "get gw failed\n");
			return -1;
		}

		if (addattr_l(&req.n, sizeof(req), RTA_GATEWAY, &data, 4)) {
			fprintf(stderr, "setup gateway attr failed\n");
			return -1;
		}
	}

	if (rt->device) {
		if (addattr_l(&req.n, sizeof(req), RTA_OIF, &rt->ifindex, 4)) {
			fprintf(stderr, "setup oif attr failed\n");
			return -1;
		}
	}

	if (strcmp(rt->dst, "default") && strcmp(rt->dst, "any") && strcmp(rt->dst, "all")) {
		unsigned mask;
		char *slash = strchr(rt->dst, '/');

		req.r.rtm_dst_len = 32;

		if (slash)
			*slash = 0;

		if (get_addr_ipv4((uint8_t *)&data, rt->dst) <= 0) {
			fprintf(stderr, "get dst failed\n");
			return -1;
		}

		if (addattr_l(&req.n, sizeof(req), RTA_DST, &data, 4)) {
			fprintf(stderr, "setup gateway attr failed\n");
			return -1;
		}

		if (slash) {
			if (get_netmask(&mask, slash + 1) < 0) {
				fprintf(stderr, "get netmask failed\n");
				return -1;
			}
			req.r.rtm_dst_len = mask;
			*slash = '/';
		}
	}

	if (rtnl_talk(rth, &req.n, 0, 0, NULL) < 0) {
		fprintf(stderr, "rtnl talk failed\n");
		return -1;
	}

	return 0;
}

static int hyper_setup_interface(struct rtnl_handle *rth,
			       struct hyper_interface *iface)
{
	uint8_t data[4];
	unsigned mask;
	struct {
		struct nlmsghdr n;
		struct ifaddrmsg ifa;
		char buf[256];
	} req;

	if (!(iface->device && iface->ipaddr && iface->mask)) {
		fprintf(stderr, "interface information incorrect\n");
		return -1;
	}

	memset(&req, 0, sizeof(req));
	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
	req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
	req.n.nlmsg_type = RTM_NEWADDR;
	req.ifa.ifa_family = AF_INET;

	iface->ifindex = hyper_get_ifindex(iface->device);
	req.ifa.ifa_index = iface->ifindex;
	req.ifa.ifa_scope = 0;

	if (get_addr_ipv4((uint8_t *)&data, iface->ipaddr) <= 0) {
		fprintf(stderr, "get addr failed\n");
		return -1;
	}

	if (addattr_l(&req.n, sizeof(req), IFA_LOCAL, &data, 4)) {
		fprintf(stderr, "setup attr failed\n");
		return -1;
	}

	if (get_netmask(&mask, iface->mask) < 0) {
		fprintf(stderr, "get netamsk failed\n");
		return -1;
	}

	req.ifa.ifa_prefixlen = mask;
	fprintf(stdout, "interface get netamsk %d %s\n", req.ifa.ifa_prefixlen, iface->mask);
	if (rtnl_talk(rth, &req.n, 0, 0, NULL) < 0) {
		perror("rtnl_talk failed");
		return -1;
	}

	if (hyper_up_nic(rth, iface->ifindex) < 0) {
		fprintf(stderr, "up device %d failed\n", iface->ifindex);
		return -1;
	}

	return 0;
}

static int hyper_cleanup_interface(struct rtnl_handle *rth,
				 struct hyper_interface *iface)
{
	uint8_t data[4];
	unsigned mask;
	struct {
		struct nlmsghdr n;
		struct ifaddrmsg ifa;
		char buf[256];
	} req;

	if (!(iface->device && iface->ipaddr && iface->mask)) {
		fprintf(stderr, "interface information incorrect\n");
		return -1;
	}

	memset(&req, 0, sizeof(req));
	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
	req.n.nlmsg_flags = NLM_F_REQUEST;
	req.n.nlmsg_type = RTM_DELADDR;
	req.ifa.ifa_family = AF_INET;

	req.ifa.ifa_index = iface->ifindex;
	req.ifa.ifa_scope = 0;

	if (get_addr_ipv4((uint8_t *)&data, iface->ipaddr) <= 0) {
		fprintf(stderr, "get addr failed\n");
		return -1;
	}

	if (addattr_l(&req.n, sizeof(req), IFA_LOCAL, &data, 4)) {
		fprintf(stderr, "setup attr failed\n");
		return -1;
	}

	if (get_netmask(&mask, iface->mask) < 0) {
		fprintf(stderr, "get netamsk failed\n");
		return -1;
	}

	req.ifa.ifa_prefixlen = mask;
	fprintf(stdout, "interface get netamsk %d %s\n", req.ifa.ifa_prefixlen, iface->mask);
	if (rtnl_talk(rth, &req.n, 0, 0, NULL) < 0) {
		perror("rtnl_talk failed");
		return -1;
	}

	/* Don't down&remove lo device */
	if (strcmp(iface->device, "lo") == 0) {
		return 0;
	}

	if (hyper_down_nic(rth, iface->ifindex) < 0) {
		fprintf(stderr, "up device %d failed\n", iface->ifindex);
		return -1;
	}

	if (hyper_remove_nic(iface->device) < 0) {
		fprintf(stderr, "remove device %s failed\n", iface->device);
		return -1;
	}

	return 0;
}

int hyper_rescan(void)
{
	int fd = open("/sys/bus/pci/rescan", O_WRONLY);

	if (fd < 0) {
		perror("can not open rescan file");
		return -1;
	}

	if (write(fd, "1\n", 2) < 0) {
		perror("can not open rescan file");
		close(fd);
		return -1;
	}
	fprintf(stdout, "finish rescan\n");
	close(fd);
	return 0;
}

int hyper_setup_network(struct hyper_pod *pod)
{
	int i, ret = 0;
	struct hyper_interface *iface;
	struct hyper_route *rt;
	struct rtnl_handle rth;

	if (hyper_rescan() < 0)
		return -1;

	if (netlink_open(&rth) < 0)
		return -1;

	for (i = 0; i < pod->i_num; i++) {
		iface = &pod->iface[i];

		ret = hyper_setup_interface(&rth, iface);
		if (ret < 0) {
			fprintf(stderr, "link up device %s failed\n", iface->device);
			goto out;
		}
	}

	ret = hyper_up_nic(&rth, 1);
	if (ret < 0) {
		fprintf(stderr, "link up lo device failed\n");
		goto out;
	}

	for (i = 0; i < pod->r_num; i++) {
		rt = &pod->rt[i];

		ret = hyper_setup_route(&rth, rt);
		if (ret < 0) {
			fprintf(stderr, "setup route failed\n");
			goto out;
		}
	}

out:
	netlink_close(&rth);
	return ret;
}

void hyper_cleanup_network(struct hyper_pod *pod)
{
	int i;
	struct rtnl_handle rth;
	struct hyper_interface *iface;
	struct hyper_route *rt;

	if (netlink_open(&rth) < 0) {
		fprintf(stdout, "open netlink failed\n");
		return;
	}

	for (i = 0; i < pod->r_num; i++) {
		rt = &pod->rt[i];

		if (hyper_cleanup_route(&rth, rt) < 0)
			fprintf(stderr, "cleanup route failed\n");

		free(rt->dst);
		free(rt->gw);
		free(rt->device);
	}

	free(pod->rt);
	pod->rt = NULL;
	pod->r_num = 0;

	for (i = 0; i < pod->i_num; i++) {
		iface = &pod->iface[i];

		if (hyper_cleanup_interface(&rth, iface) < 0)
			fprintf(stderr, "link down device %s failed\n", iface->device);

		free(iface->device);
		free(iface->ipaddr);
		free(iface->mask);
	}

	free(pod->iface);
	pod->iface = NULL;
	pod->i_num = 0;
	netlink_close(&rth);
}

int hyper_setup_dns(struct hyper_pod *pod)
{
	int i, fd, ret = -1;
	char buf[28];

	if (pod->dns == NULL)
		return 0;

	fd = open("/tmp/hyper/resolv.conf", O_CREAT| O_TRUNC| O_WRONLY, 0644);

	if (fd < 0) {
		perror("create /tmp/resolv.conf failed");
		return -1;
	}

	for (i = 0; i < pod->d_num; i++) {
		int size = snprintf(buf, sizeof(buf), "nameserver %s\n", pod->dns[i]);
		int len = 0, l;

		if (size < 0) {
			fprintf(stderr, "sprintf resolv.conf entry failed\n");
			goto out;
		}

		while (len < size) {
			l = write(fd, buf + len, size - len);
			if (l < 0) {
				perror("fail to write resolv.conf");
				goto out;
			}
			len += l;
		}
	}

	ret = 0;
out:
	close(fd);
	return ret;
}

void hyper_cleanup_dns(struct hyper_pod *pod)
{
	int fd, i;

	for (i = 0; i < pod->d_num; i++) {
		free(pod->dns[i]);
	}

	free(pod->dns);
	pod->dns = NULL;
	pod->d_num = 0;

	fd = open("/tmp/hyper/resolv.conf", O_WRONLY| O_TRUNC);
	if (fd < 0) {
		perror("open /tmp/hyper/resolv.conf failed");
		return;
	}

	close(fd);
}