/*
 * Copyright (c) 2010 Nicira Networks.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <config.h>

#include "netdev-vport.h"

#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <sys/ioctl.h>

#include "list.h"
#include "netdev-provider.h"
#include "openvswitch/datapath-protocol.h"
#include "openvswitch/tunnel.h"
#include "packets.h"
#include "shash.h"
#include "socket-util.h"
#include "vlog.h"

VLOG_DEFINE_THIS_MODULE(netdev_vport)

struct netdev_vport_notifier {
    struct netdev_notifier notifier;
    struct list list_node;
    struct shash_node *shash_node;
};

struct netdev_dev_vport {
    struct netdev_dev netdev_dev;
};

struct netdev_vport {
    struct netdev netdev;
};

struct vport_info {
    const char *devname;
    const char *type;
    void *config;
};

struct vport_class {
    const struct netdev_class netdev_class;
    int (*parse_config)(struct vport_info *port, const struct shash *args);
};

static struct shash netdev_vport_notifiers =
                                    SHASH_INITIALIZER(&netdev_vport_notifiers);

static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);

static int netdev_vport_do_ioctl(int cmd, void *arg);
static int netdev_vport_create(const struct netdev_class *, const char *,
                               const struct shash *, struct netdev_dev **);
static void netdev_vport_poll_notify(const struct netdev *);

static bool
is_vport_class(const struct netdev_class *class)
{
    return class->create == netdev_vport_create;
}

static const struct vport_class *
vport_class_cast(const struct netdev_class *class)
{
    assert(is_vport_class(class));
    return CONTAINER_OF(class, struct vport_class, netdev_class);
}

static struct netdev_dev_vport *
netdev_dev_vport_cast(const struct netdev_dev *netdev_dev)
{
    assert(is_vport_class(netdev_dev_get_class(netdev_dev)));
    return CONTAINER_OF(netdev_dev, struct netdev_dev_vport, netdev_dev);
}

static struct netdev_vport *
netdev_vport_cast(const struct netdev *netdev)
{
    struct netdev_dev *netdev_dev = netdev_get_dev(netdev);
    assert(is_vport_class(netdev_dev_get_class(netdev_dev)));
    return CONTAINER_OF(netdev, struct netdev_vport, netdev);
}

static int
netdev_vport_parse_config(const struct netdev_class *netdev_class,
                          const char *name, const struct shash *args,
                          void **configp)
{
    const struct vport_class *c = vport_class_cast(netdev_class);
    if (c->parse_config) {
        struct vport_info info;
        int error;

        info.devname = name;
        info.type = netdev_class->type;
        error = (c->parse_config)(&info, args);
        *configp = info.config;
        return error;
    } else {
        if (!shash_is_empty(args)) {
            VLOG_WARN("%s: arguments for %s vports should be empty",
                      name, netdev_class->type);
        }
        *configp = NULL;
        return 0;
    }
}

static int
netdev_vport_create(const struct netdev_class *class, const char *name,
                    const struct shash *args OVS_UNUSED,
                    struct netdev_dev **netdev_devp)
{
    int err;
    struct odp_vport_add ova;
    struct netdev_dev_vport *netdev_dev;

    ovs_strlcpy(ova.port_type, class->type, sizeof ova.port_type);
    ovs_strlcpy(ova.devname, name, sizeof ova.devname);
    err = netdev_vport_parse_config(class, name, args, &ova.config);
    if (err) {
        goto exit;
    }

    err = netdev_vport_do_ioctl(ODP_VPORT_ADD, &ova);

    if (err == EBUSY) {
        VLOG_WARN("%s: destroying existing device", name);

        err = netdev_vport_do_ioctl(ODP_VPORT_DEL, ova.devname);
        if (err) {
            goto exit;
        }

        err = netdev_vport_do_ioctl(ODP_VPORT_ADD, &ova);
    }
    if (err) {
        goto exit;
    }

    netdev_dev = xmalloc(sizeof *netdev_dev);
    netdev_dev_init(&netdev_dev->netdev_dev, name, class);

    *netdev_devp = &netdev_dev->netdev_dev;

exit:
    free(ova.config);
    return err;
}

static void
netdev_vport_destroy(struct netdev_dev *netdev_dev_)
{
    struct netdev_dev_vport *netdev_dev = netdev_dev_vport_cast(netdev_dev_);

    free(netdev_dev);
}

static int
netdev_vport_open(struct netdev_dev *netdev_dev_, int ethertype OVS_UNUSED,
                struct netdev **netdevp)
{
    struct netdev_vport *netdev;

    netdev = xmalloc(sizeof *netdev);
    netdev_init(&netdev->netdev, netdev_dev_);

    *netdevp = &netdev->netdev;
    return 0;
}

static void
netdev_vport_close(struct netdev *netdev_)
{
    struct netdev_vport *netdev = netdev_vport_cast(netdev_);
    free(netdev);
}

static int
netdev_vport_reconfigure(struct netdev_dev *netdev_dev,
                         const struct shash *args)
{
    const char *name = netdev_dev_get_name(netdev_dev);
    struct odp_vport_mod ovm;
    int err;

    ovs_strlcpy(ovm.devname, name, sizeof ovm.devname);
    err = netdev_vport_parse_config(netdev_dev_get_class(netdev_dev), name,
                                    args, &ovm.config);
    if (err) {
        return err;
    }

    err = netdev_vport_do_ioctl(ODP_VPORT_MOD, &ovm);
    free(ovm.config);
    return err;
}

static int
netdev_vport_set_etheraddr(struct netdev *netdev,
                           const uint8_t mac[ETH_ADDR_LEN])
{
    struct odp_vport_ether vport_ether;
    int err;

    ovs_strlcpy(vport_ether.devname, netdev_get_name(netdev),
                sizeof vport_ether.devname);

    memcpy(vport_ether.ether_addr, mac, ETH_ADDR_LEN);

    err = netdev_vport_do_ioctl(ODP_VPORT_ETHER_SET, &vport_ether);
    if (err) {
        return err;
    }

    netdev_vport_poll_notify(netdev);
    return 0;
}

static int
netdev_vport_get_etheraddr(const struct netdev *netdev,
                           uint8_t mac[ETH_ADDR_LEN])
{
    struct odp_vport_ether vport_ether;
    int err;

    ovs_strlcpy(vport_ether.devname, netdev_get_name(netdev),
                sizeof vport_ether.devname);

    err = netdev_vport_do_ioctl(ODP_VPORT_ETHER_GET, &vport_ether);
    if (err) {
        return err;
    }

    memcpy(mac, vport_ether.ether_addr, ETH_ADDR_LEN);
    return 0;
}

static int
netdev_vport_get_mtu(const struct netdev *netdev, int *mtup)
{
    struct odp_vport_mtu vport_mtu;
    int err;

    ovs_strlcpy(vport_mtu.devname, netdev_get_name(netdev),
                sizeof vport_mtu.devname);

    err = netdev_vport_do_ioctl(ODP_VPORT_MTU_GET, &vport_mtu);
    if (err) {
        return err;
    }

    *mtup = vport_mtu.mtu;
    return 0;
}

static int
netdev_vport_get_carrier(const struct netdev *netdev OVS_UNUSED, bool *carrier)
{
    *carrier = true;
    return 0;
}

int
netdev_vport_get_stats(const struct netdev *netdev, struct netdev_stats *stats)
{
    const char *name = netdev_get_name(netdev);
    struct odp_vport_stats_req ovsr;
    int err;

    ovs_strlcpy(ovsr.devname, name, sizeof ovsr.devname);
    err = netdev_vport_do_ioctl(ODP_VPORT_STATS_GET, &ovsr);
    if (err) {
        return err;
    }

    stats->rx_packets = ovsr.stats.rx_packets;
    stats->tx_packets = ovsr.stats.tx_packets;
    stats->rx_bytes = ovsr.stats.rx_bytes;
    stats->tx_bytes = ovsr.stats.tx_bytes;
    stats->rx_errors = ovsr.stats.rx_errors;
    stats->tx_errors = ovsr.stats.tx_errors;
    stats->rx_dropped = ovsr.stats.rx_dropped;
    stats->tx_dropped = ovsr.stats.tx_dropped;
    stats->multicast = UINT64_MAX;
    stats->collisions = ovsr.stats.collisions;
    stats->rx_length_errors = UINT64_MAX;
    stats->rx_over_errors = ovsr.stats.rx_over_err;
    stats->rx_crc_errors = ovsr.stats.rx_crc_err;
    stats->rx_frame_errors = ovsr.stats.rx_frame_err;
    stats->rx_fifo_errors = UINT64_MAX;
    stats->rx_missed_errors = UINT64_MAX;
    stats->tx_aborted_errors = UINT64_MAX;
    stats->tx_carrier_errors = UINT64_MAX;
    stats->tx_fifo_errors = UINT64_MAX;
    stats->tx_heartbeat_errors = UINT64_MAX;
    stats->tx_window_errors = UINT64_MAX;

    return 0;
}

int
netdev_vport_set_stats(struct netdev *netdev, const struct netdev_stats *stats)
{
    struct odp_vport_stats_req ovsr;
    int err;

    ovs_strlcpy(ovsr.devname, netdev_get_name(netdev), sizeof ovsr.devname);

    ovsr.stats.rx_packets = stats->rx_packets;
    ovsr.stats.tx_packets = stats->tx_packets;
    ovsr.stats.rx_bytes = stats->rx_bytes;
    ovsr.stats.tx_bytes = stats->tx_bytes;
    ovsr.stats.rx_errors = stats->rx_errors;
    ovsr.stats.tx_errors = stats->tx_errors;
    ovsr.stats.rx_dropped = stats->rx_dropped;
    ovsr.stats.tx_dropped = stats->tx_dropped;
    ovsr.stats.collisions = stats->collisions;
    ovsr.stats.rx_over_err = stats->rx_over_errors;
    ovsr.stats.rx_crc_err = stats->rx_crc_errors;
    ovsr.stats.rx_frame_err = stats->rx_frame_errors;

    err = netdev_vport_do_ioctl(ODP_VPORT_STATS_SET, &ovsr);

    /* If the vport layer doesn't know about the device, that doesn't mean it
     * doesn't exist (after all were able to open it when netdev_open() was
     * called), it just means that it isn't attached and we'll be getting
     * stats a different way. */
    if (err == ENODEV) {
        err = EOPNOTSUPP;
    }

    return err;
}

static int
netdev_vport_update_flags(struct netdev *netdev OVS_UNUSED,
                        enum netdev_flags off, enum netdev_flags on OVS_UNUSED,
                        enum netdev_flags *old_flagsp)
{
    if (off & (NETDEV_UP | NETDEV_PROMISC)) {
        return EOPNOTSUPP;
    }

    *old_flagsp = NETDEV_UP | NETDEV_PROMISC;
    return 0;
}

static char *
make_poll_name(const struct netdev *netdev)
{
    return xasprintf("%s:%s", netdev_get_type(netdev), netdev_get_name(netdev));
}

static int
netdev_vport_poll_add(struct netdev *netdev,
                      void (*cb)(struct netdev_notifier *), void *aux,
                      struct netdev_notifier **notifierp)
{
    char *poll_name = make_poll_name(netdev);
    struct netdev_vport_notifier *notifier;
    struct list *list;
    struct shash_node *shash_node;

    shash_node = shash_find_data(&netdev_vport_notifiers, poll_name);
    if (!shash_node) {
        list = xmalloc(sizeof *list);
        list_init(list);
        shash_node = shash_add(&netdev_vport_notifiers,
			       netdev_get_name(netdev), list);
    } else {
        list = shash_node->data;
    }

    notifier = xmalloc(sizeof *notifier);
    netdev_notifier_init(&notifier->notifier, netdev, cb, aux);
    list_push_back(list, &notifier->list_node);
    notifier->shash_node = shash_node;

    *notifierp = &notifier->notifier;
    free(poll_name);

    return 0;
}

static void
netdev_vport_poll_remove(struct netdev_notifier *notifier_)
{
    struct netdev_vport_notifier *notifier =
                CONTAINER_OF(notifier_, struct netdev_vport_notifier, notifier);

    struct list *list;

    list = list_remove(&notifier->list_node);
    if (list_is_empty(list)) {
        shash_delete(&netdev_vport_notifiers, notifier->shash_node);
        free(list);
    }

    free(notifier);
}

/* Helper functions. */

static int
netdev_vport_do_ioctl(int cmd, void *arg)
{
    static int ioctl_fd = -1;

    if (ioctl_fd < 0) {
        ioctl_fd = open("/dev/net/dp0", O_RDONLY | O_NONBLOCK);
        if (ioctl_fd < 0) {
            VLOG_ERR_RL(&rl, "failed to open ioctl fd: %s", strerror(errno));
            return errno;
        }
    }

    return ioctl(ioctl_fd, cmd, arg) ? errno : 0;
}

static void
netdev_vport_poll_notify(const struct netdev *netdev)
{
    char *poll_name = make_poll_name(netdev);
    struct list *list = shash_find_data(&netdev_vport_notifiers,
                                        poll_name);

    if (list) {
        struct netdev_vport_notifier *notifier;

        LIST_FOR_EACH (notifier, list_node, list) {
            struct netdev_notifier *n = &notifier->notifier;
            n->cb(n);
        }
    }

    free(poll_name);
}

/* Code specific to individual vport types. */

static int
parse_tunnel_config(struct vport_info *port, const struct shash *args)
{
    const char *name = port->devname;
    bool is_gre = !strcmp(port->type, "gre");
    struct tnl_port_config *config;
    struct shash_node *node;
    bool ipsec_ip_set = false;
    bool ipsec_mech_set = false;

    config = port->config = xzalloc(sizeof *config);
    config->flags |= TNL_F_PMTUD;
    config->flags |= TNL_F_HDR_CACHE;

    SHASH_FOR_EACH (node, args) {
        if (!strcmp(node->name, "remote_ip")) {
            struct in_addr in_addr;
            if (lookup_ip(node->data, &in_addr)) {
                VLOG_WARN("%s: bad %s 'remote_ip'", name, port->type);
            } else {
                config->daddr = in_addr.s_addr;
            }
        } else if (!strcmp(node->name, "local_ip")) {
            struct in_addr in_addr;
            if (lookup_ip(node->data, &in_addr)) {
                VLOG_WARN("%s: bad %s 'local_ip'", name, port->type);
            } else {
                config->saddr = in_addr.s_addr;
            }
        } else if (!strcmp(node->name, "key") && is_gre) {
            if (!strcmp(node->data, "flow")) {
                config->flags |= TNL_F_IN_KEY_MATCH;
                config->flags |= TNL_F_OUT_KEY_ACTION;
            } else {
                config->out_key = config->in_key = htonl(atoi(node->data));
            }
        } else if (!strcmp(node->name, "in_key") && is_gre) {
            if (!strcmp(node->data, "flow")) {
                config->flags |= TNL_F_IN_KEY_MATCH;
            } else {
                config->in_key = htonl(atoi(node->data));
            }
        } else if (!strcmp(node->name, "out_key") && is_gre) {
            if (!strcmp(node->data, "flow")) {
                config->flags |= TNL_F_OUT_KEY_ACTION;
            } else {
                config->out_key = htonl(atoi(node->data));
            }
        } else if (!strcmp(node->name, "tos")) {
            if (!strcmp(node->data, "inherit")) {
                config->flags |= TNL_F_TOS_INHERIT;
            } else {
                config->tos = atoi(node->data);
            }
        } else if (!strcmp(node->name, "ttl")) {
            if (!strcmp(node->data, "inherit")) {
                config->flags |= TNL_F_TTL_INHERIT;
            } else {
                config->ttl = atoi(node->data);
            }
        } else if (!strcmp(node->name, "csum") && is_gre) {
            if (!strcmp(node->data, "true")) {
                config->flags |= TNL_F_CSUM;
            }
        } else if (!strcmp(node->name, "pmtud")) {
            if (!strcmp(node->data, "false")) {
                config->flags &= ~TNL_F_PMTUD;
            }
        } else if (!strcmp(node->name, "header_cache")) {
            if (!strcmp(node->data, "false")) {
                config->flags &= ~TNL_F_HDR_CACHE;
            }
        } else if (!strcmp(node->name, "ipsec_local_ip")) {
            ipsec_ip_set = true;
        } else if (!strcmp(node->name, "ipsec_cert")
                   || !strcmp(node->name, "ipsec_psk")) {
            ipsec_mech_set = true;
        } else {
            VLOG_WARN("%s: unknown %s argument '%s'",
                      name, port->type, node->name);
        }
    }

   /* IPsec doesn't work when header caching is enabled.  Disable it if the
    * IPsec local IP address and authentication mechanism have been defined. */
    if (ipsec_ip_set && ipsec_mech_set) {
        VLOG_INFO("%s: header caching disabled due to use of IPsec", name);
        config->flags &= ~TNL_F_HDR_CACHE;
    }

    if (!config->daddr) {
        VLOG_WARN("%s: %s type requires valid 'remote_ip' argument",
                  name, port->type);
        return EINVAL;
    }

    return 0;
}

static int
parse_patch_config(struct vport_info *port, const struct shash *args)
{
    const char *name = port->devname;
    const char *peer;

    peer = shash_find_data(args, "peer");
    if (!peer) {
        VLOG_WARN("%s: patch type requires valid 'peer' argument", name);
        return EINVAL;
    }

    if (shash_count(args) > 1) {
        VLOG_WARN("%s: patch type takes only a 'peer' argument", name);
        return EINVAL;
    }

    if (strlen(peer) >= IFNAMSIZ) {
        VLOG_WARN("%s: patch 'peer' arg too long", name);
        return EINVAL;
    }

    if (!strcmp(name, peer)) {
        VLOG_WARN("%s: patch peer must not be self", name);
        return EINVAL;
    }

    port->config = xstrdup(peer);

    return 0;
}

#define VPORT_FUNCTIONS                                     \
    NULL,                       /* init */                  \
    NULL,                       /* run */                   \
    NULL,                       /* wait */                  \
                                                            \
    netdev_vport_create,                                    \
    netdev_vport_destroy,                                   \
    netdev_vport_reconfigure,                               \
                                                            \
    netdev_vport_open,                                      \
    netdev_vport_close,                                     \
                                                            \
    NULL,                       /* enumerate */             \
                                                            \
    NULL,                       /* recv */                  \
    NULL,                       /* recv_wait */             \
    NULL,                       /* drain */                 \
                                                            \
    NULL,                       /* send */                  \
    NULL,                       /* send_wait */             \
                                                            \
    netdev_vport_set_etheraddr,                             \
    netdev_vport_get_etheraddr,                             \
    netdev_vport_get_mtu,                                   \
    NULL,                       /* get_ifindex */           \
    netdev_vport_get_carrier,                               \
    netdev_vport_get_stats,                                 \
    netdev_vport_set_stats,                                 \
                                                            \
    NULL,                       /* get_features */          \
    NULL,                       /* set_advertisements */    \
    NULL,                       /* get_vlan_vid */          \
                                                            \
    NULL,                       /* set_policing */          \
    NULL,                       /* get_qos_types */         \
    NULL,                       /* get_qos_capabilities */  \
    NULL,                       /* get_qos */               \
    NULL,                       /* set_qos */               \
    NULL,                       /* get_queue */             \
    NULL,                       /* set_queue */             \
    NULL,                       /* delete_queue */          \
    NULL,                       /* get_queue_stats */       \
    NULL,                       /* dump_queues */           \
    NULL,                       /* dump_queue_stats */      \
                                                            \
    NULL,                       /* get_in4 */               \
    NULL,                       /* set_in4 */               \
    NULL,                       /* get_in6 */               \
    NULL,                       /* add_router */            \
    NULL,                       /* get_next_hop */          \
    NULL,                       /* arp_lookup */            \
                                                            \
    netdev_vport_update_flags,                              \
                                                            \
    netdev_vport_poll_add,                                  \
    netdev_vport_poll_remove,

static const struct vport_class vport_gre_class
        = { { "gre", VPORT_FUNCTIONS }, parse_tunnel_config };

static const struct vport_class vport_capwap_class
        = { { "capwap", VPORT_FUNCTIONS }, parse_tunnel_config };

static const struct vport_class vport_patch_class
        = { { "patch", VPORT_FUNCTIONS }, parse_patch_config };

void
netdev_vport_register(void)
{
    netdev_register_provider(&vport_gre_class.netdev_class);
    netdev_register_provider(&vport_capwap_class.netdev_class);
    netdev_register_provider(&vport_patch_class.netdev_class);
}