// SPDX-License-Identifier: GPL-2.0
/*
 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 *  Generic netlink support functions to configure an SMC-R PNET table
 *
 *  Copyright IBM Corp. 2016
 *
 *  Author(s):  Thomas Richter <tmricht@linux.vnet.ibm.com>
 */

#include <linux/module.h>
#include <linux/list.h>
#include <linux/ctype.h>
#include <linux/mutex.h>
#include <net/netlink.h>
#include <net/genetlink.h>

#include <uapi/linux/if.h>
#include <uapi/linux/smc.h>

#include <rdma/ib_verbs.h>

#include <net/netns/generic.h>
#include "smc_netns.h"

#include "smc_pnet.h"
#include "smc_ib.h"
#include "smc_ism.h"
#include "smc_core.h"

static struct net_device *__pnet_find_base_ndev(struct net_device *ndev);
static struct net_device *pnet_find_base_ndev(struct net_device *ndev);

static const struct nla_policy smc_pnet_policy[SMC_PNETID_MAX + 1] = {
        [SMC_PNETID_NAME] = {
                .type = NLA_NUL_STRING,
                .len = SMC_MAX_PNETID_LEN
        },
        [SMC_PNETID_ETHNAME] = {
                .type = NLA_NUL_STRING,
                .len = IFNAMSIZ - 1
        },
        [SMC_PNETID_IBNAME] = {
                .type = NLA_NUL_STRING,
                .len = IB_DEVICE_NAME_MAX - 1
        },
        [SMC_PNETID_IBPORT] = { .type = NLA_U8 }
};

static struct genl_family smc_pnet_nl_family;

enum smc_pnet_nametype {
        SMC_PNET_ETH    = 1,
        SMC_PNET_IB     = 2,
};

/* pnet entry stored in pnet table */
struct smc_pnetentry {
        struct list_head list;
        char pnet_name[SMC_MAX_PNETID_LEN + 1];
        enum smc_pnet_nametype type;
        union {
                struct {
                        char eth_name[IFNAMSIZ + 1];
                        struct net_device *ndev;
                        netdevice_tracker dev_tracker;
                };
                struct {
                        char ib_name[IB_DEVICE_NAME_MAX + 1];
                        u8 ib_port;
                };
        };
};

/* Check if the pnetid is set */
bool smc_pnet_is_pnetid_set(u8 *pnetid)
{
        if (pnetid[0] == 0 || pnetid[0] == _S)
                return false;
        return true;
}

/* Check if two given pnetids match */
static bool smc_pnet_match(u8 *pnetid1, u8 *pnetid2)
{
        int i;

        for (i = 0; i < SMC_MAX_PNETID_LEN; i++) {
                if ((pnetid1[i] == 0 || pnetid1[i] == _S) &&
                    (pnetid2[i] == 0 || pnetid2[i] == _S))
                        break;
                if (pnetid1[i] != pnetid2[i])
                        return false;
        }
        return true;
}

/* Remove a pnetid from the pnet table.
 */
static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
{
        struct smc_pnetentry *pnetelem, *tmp_pe;
        struct smc_pnettable *pnettable;
        struct smc_ib_device *ibdev;
        struct smcd_dev *smcd;
        struct smc_net *sn;
        int rc = -ENOENT;
        int ibport;

        /* get pnettable for namespace */
        sn = net_generic(net, smc_net_id);
        pnettable = &sn->pnettable;

        /* remove table entry */
        mutex_lock(&pnettable->lock);
        list_for_each_entry_safe(pnetelem, tmp_pe, &pnettable->pnetlist,
                                 list) {
                if (!pnet_name ||
                    smc_pnet_match(pnetelem->pnet_name, pnet_name)) {
                        list_del(&pnetelem->list);
                        if (pnetelem->type == SMC_PNET_ETH && pnetelem->ndev) {
                                netdev_put(pnetelem->ndev,
                                           &pnetelem->dev_tracker);
                                pr_warn_ratelimited("smc: net device %s "
                                                    "erased user defined "
                                                    "pnetid %.16s\n",
                                                    pnetelem->eth_name,
                                                    pnetelem->pnet_name);
                        }
                        kfree(pnetelem);
                        rc = 0;
                }
        }
        mutex_unlock(&pnettable->lock);

        /* if this is not the initial namespace, stop here */
        if (net != &init_net)
                return rc;

        /* remove ib devices */
        mutex_lock(&smc_ib_devices.mutex);
        list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
                for (ibport = 0; ibport < SMC_MAX_PORTS; ibport++) {
                        if (ibdev->pnetid_by_user[ibport] &&
                            (!pnet_name ||
                             smc_pnet_match(pnet_name,
                                            ibdev->pnetid[ibport]))) {
                                pr_warn_ratelimited("smc: ib device %s ibport "
                                                    "%d erased user defined "
                                                    "pnetid %.16s\n",
                                                    ibdev->ibdev->name,
                                                    ibport + 1,
                                                    ibdev->pnetid[ibport]);
                                memset(ibdev->pnetid[ibport], 0,
                                       SMC_MAX_PNETID_LEN);
                                ibdev->pnetid_by_user[ibport] = false;
                                rc = 0;
                        }
                }
        }
        mutex_unlock(&smc_ib_devices.mutex);
        /* remove smcd devices */
        mutex_lock(&smcd_dev_list.mutex);
        list_for_each_entry(smcd, &smcd_dev_list.list, list) {
                if (smcd->pnetid_by_user &&
                    (!pnet_name ||
                     smc_pnet_match(pnet_name, smcd->pnetid))) {
                        pr_warn_ratelimited("smc: smcd device %s "
                                            "erased user defined pnetid "
                                            "%.16s\n",
                                            dev_name(&smcd->dibs->dev),
                                            smcd->pnetid);
                        memset(smcd->pnetid, 0, SMC_MAX_PNETID_LEN);
                        smcd->pnetid_by_user = false;
                        rc = 0;
                }
        }
        mutex_unlock(&smcd_dev_list.mutex);
        return rc;
}

/* Add the reference to a given network device to the pnet table.
 */
static int smc_pnet_add_by_ndev(struct net_device *ndev)
{
        struct smc_pnetentry *pnetelem, *tmp_pe;
        struct smc_pnettable *pnettable;
        struct net *net = dev_net(ndev);
        struct smc_net *sn;
        int rc = -ENOENT;

        /* get pnettable for namespace */
        sn = net_generic(net, smc_net_id);
        pnettable = &sn->pnettable;

        mutex_lock(&pnettable->lock);
        list_for_each_entry_safe(pnetelem, tmp_pe, &pnettable->pnetlist, list) {
                if (pnetelem->type == SMC_PNET_ETH && !pnetelem->ndev &&
                    !strncmp(pnetelem->eth_name, ndev->name, IFNAMSIZ)) {
                        netdev_hold(ndev, &pnetelem->dev_tracker, GFP_ATOMIC);
                        pnetelem->ndev = ndev;
                        rc = 0;
                        pr_warn_ratelimited("smc: adding net device %s with "
                                            "user defined pnetid %.16s\n",
                                            pnetelem->eth_name,
                                            pnetelem->pnet_name);
                        break;
                }
        }
        mutex_unlock(&pnettable->lock);
        return rc;
}

/* Remove the reference to a given network device from the pnet table.
 */
static int smc_pnet_remove_by_ndev(struct net_device *ndev)
{
        struct smc_pnetentry *pnetelem, *tmp_pe;
        struct smc_pnettable *pnettable;
        struct net *net = dev_net(ndev);
        struct smc_net *sn;
        int rc = -ENOENT;

        /* get pnettable for namespace */
        sn = net_generic(net, smc_net_id);
        pnettable = &sn->pnettable;

        mutex_lock(&pnettable->lock);
        list_for_each_entry_safe(pnetelem, tmp_pe, &pnettable->pnetlist, list) {
                if (pnetelem->type == SMC_PNET_ETH && pnetelem->ndev == ndev) {
                        netdev_put(pnetelem->ndev, &pnetelem->dev_tracker);
                        pnetelem->ndev = NULL;
                        rc = 0;
                        pr_warn_ratelimited("smc: removing net device %s with "
                                            "user defined pnetid %.16s\n",
                                            pnetelem->eth_name,
                                            pnetelem->pnet_name);
                        break;
                }
        }
        mutex_unlock(&pnettable->lock);
        return rc;
}

/* Apply pnetid to ib device when no pnetid is set.
 */
static bool smc_pnet_apply_ib(struct smc_ib_device *ib_dev, u8 ib_port,
                              char *pnet_name)
{
        bool applied = false;

        mutex_lock(&smc_ib_devices.mutex);
        if (!smc_pnet_is_pnetid_set(ib_dev->pnetid[ib_port - 1])) {
                memcpy(ib_dev->pnetid[ib_port - 1], pnet_name,
                       SMC_MAX_PNETID_LEN);
                ib_dev->pnetid_by_user[ib_port - 1] = true;
                applied = true;
        }
        mutex_unlock(&smc_ib_devices.mutex);
        return applied;
}

/* Apply pnetid to smcd device when no pnetid is set.
 */
static bool smc_pnet_apply_smcd(struct smcd_dev *smcd_dev, char *pnet_name)
{
        bool applied = false;

        mutex_lock(&smcd_dev_list.mutex);
        if (!smc_pnet_is_pnetid_set(smcd_dev->pnetid)) {
                memcpy(smcd_dev->pnetid, pnet_name, SMC_MAX_PNETID_LEN);
                smcd_dev->pnetid_by_user = true;
                applied = true;
        }
        mutex_unlock(&smcd_dev_list.mutex);
        return applied;
}

/* The limit for pnetid is 16 characters.
 * Valid characters should be (single-byte character set) a-z, A-Z, 0-9.
 * Lower case letters are converted to upper case.
 * Interior blanks should not be used.
 */
static bool smc_pnetid_valid(const char *pnet_name, char *pnetid)
{
        char *bf = skip_spaces(pnet_name);
        size_t len = strlen(bf);
        char *end = bf + len;

        if (!len)
                return false;
        while (--end >= bf && isspace(*end))
                ;
        if (end - bf >= SMC_MAX_PNETID_LEN)
                return false;
        while (bf <= end) {
                if (!isalnum(*bf))
                        return false;
                *pnetid++ = islower(*bf) ? toupper(*bf) : *bf;
                bf++;
        }
        *pnetid = '\0';
        return true;
}

/* Find an infiniband device by a given name. The device might not exist. */
static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
{
        struct smc_ib_device *ibdev;

        mutex_lock(&smc_ib_devices.mutex);
        list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
                if (!strncmp(ibdev->ibdev->name, ib_name,
                             sizeof(ibdev->ibdev->name)) ||
                    (ibdev->ibdev->dev.parent &&
                     !strncmp(dev_name(ibdev->ibdev->dev.parent), ib_name,
                             IB_DEVICE_NAME_MAX - 1))) {
                        goto out;
                }
        }
        ibdev = NULL;
out:
        mutex_unlock(&smc_ib_devices.mutex);
        return ibdev;
}

/* Find an smcd device by a given name. The device might not exist. */
static struct smcd_dev *smc_pnet_find_smcd(char *smcd_name)
{
        struct smcd_dev *smcd_dev;

        mutex_lock(&smcd_dev_list.mutex);
        list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
                if (!strncmp(dev_name(&smcd_dev->dibs->dev), smcd_name,
                             IB_DEVICE_NAME_MAX - 1) ||
                    (smcd_dev->dibs->dev.parent &&
                     !strncmp(dev_name(smcd_dev->dibs->dev.parent), smcd_name,
                              IB_DEVICE_NAME_MAX - 1)))
                        goto out;
        }
        smcd_dev = NULL;
out:
        mutex_unlock(&smcd_dev_list.mutex);
        return smcd_dev;
}

static int smc_pnet_add_eth(struct smc_pnettable *pnettable, struct net *net,
                            char *eth_name, char *pnet_name)
{
        struct smc_pnetentry *tmp_pe, *new_pe;
        struct net_device *ndev, *base_ndev;
        u8 ndev_pnetid[SMC_MAX_PNETID_LEN];
        bool new_netdev;
        int rc;

        /* check if (base) netdev already has a pnetid. If there is one, we do
         * not want to add a pnet table entry
         */
        rc = -EEXIST;
        ndev = dev_get_by_name(net, eth_name);  /* dev_hold() */
        if (ndev) {
                base_ndev = pnet_find_base_ndev(ndev);
                if (!smc_pnetid_by_dev_port(base_ndev->dev.parent,
                                            base_ndev->dev_port, ndev_pnetid))
                        goto out_put;
        }

        /* add a new netdev entry to the pnet table if there isn't one */
        rc = -ENOMEM;
        new_pe = kzalloc_obj(*new_pe);
        if (!new_pe)
                goto out_put;
        new_pe->type = SMC_PNET_ETH;
        memcpy(new_pe->pnet_name, pnet_name, SMC_MAX_PNETID_LEN);
        strscpy(new_pe->eth_name, eth_name);
        rc = -EEXIST;
        new_netdev = true;
        mutex_lock(&pnettable->lock);
        list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) {
                if (tmp_pe->type == SMC_PNET_ETH &&
                    !strncmp(tmp_pe->eth_name, eth_name, IFNAMSIZ)) {
                        new_netdev = false;
                        break;
                }
        }
        if (new_netdev) {
                if (ndev) {
                        new_pe->ndev = ndev;
                        netdev_tracker_alloc(ndev, &new_pe->dev_tracker,
                                             GFP_ATOMIC);
                }
                list_add_tail(&new_pe->list, &pnettable->pnetlist);
                mutex_unlock(&pnettable->lock);
        } else {
                mutex_unlock(&pnettable->lock);
                kfree(new_pe);
                goto out_put;
        }
        if (ndev)
                pr_warn_ratelimited("smc: net device %s "
                                    "applied user defined pnetid %.16s\n",
                                    new_pe->eth_name, new_pe->pnet_name);
        return 0;

out_put:
        dev_put(ndev);
        return rc;
}

static int smc_pnet_add_ib(struct smc_pnettable *pnettable, char *ib_name,
                           u8 ib_port, char *pnet_name)
{
        struct smc_pnetentry *tmp_pe, *new_pe;
        struct smc_ib_device *ib_dev;
        bool smcddev_applied = true;
        bool ibdev_applied = true;
        struct smcd_dev *smcd;
        bool new_ibdev;

        /* try to apply the pnetid to active devices */
        ib_dev = smc_pnet_find_ib(ib_name);
        if (ib_dev) {
                ibdev_applied = smc_pnet_apply_ib(ib_dev, ib_port, pnet_name);
                if (ibdev_applied)
                        pr_warn_ratelimited("smc: ib device %s ibport %d "
                                            "applied user defined pnetid "
                                            "%.16s\n", ib_dev->ibdev->name,
                                            ib_port,
                                            ib_dev->pnetid[ib_port - 1]);
        }
        smcd = smc_pnet_find_smcd(ib_name);
        if (smcd) {
                smcddev_applied = smc_pnet_apply_smcd(smcd, pnet_name);
                if (smcddev_applied) {
                        pr_warn_ratelimited("smc: smcd device %s applied user defined pnetid %.16s\n",
                                            dev_name(&smcd->dibs->dev),
                                            smcd->pnetid);
                }
        }
        /* Apply fails when a device has a hardware-defined pnetid set, do not
         * add a pnet table entry in that case.
         */
        if (!ibdev_applied || !smcddev_applied)
                return -EEXIST;

        /* add a new ib entry to the pnet table if there isn't one */
        new_pe = kzalloc_obj(*new_pe);
        if (!new_pe)
                return -ENOMEM;
        new_pe->type = SMC_PNET_IB;
        memcpy(new_pe->pnet_name, pnet_name, SMC_MAX_PNETID_LEN);
        strscpy(new_pe->ib_name, ib_name);
        new_pe->ib_port = ib_port;

        new_ibdev = true;
        mutex_lock(&pnettable->lock);
        list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) {
                if (tmp_pe->type == SMC_PNET_IB &&
                    !strncmp(tmp_pe->ib_name, ib_name, IB_DEVICE_NAME_MAX)) {
                        new_ibdev = false;
                        break;
                }
        }
        if (new_ibdev) {
                list_add_tail(&new_pe->list, &pnettable->pnetlist);
                mutex_unlock(&pnettable->lock);
        } else {
                mutex_unlock(&pnettable->lock);
                kfree(new_pe);
        }
        return (new_ibdev) ? 0 : -EEXIST;
}

/* Append a pnetid to the end of the pnet table if not already on this list.
 */
static int smc_pnet_enter(struct net *net, struct nlattr *tb[])
{
        char pnet_name[SMC_MAX_PNETID_LEN + 1];
        struct smc_pnettable *pnettable;
        bool new_netdev = false;
        bool new_ibdev = false;
        struct smc_net *sn;
        u8 ibport = 1;
        char *string;
        int rc;

        /* get pnettable for namespace */
        sn = net_generic(net, smc_net_id);
        pnettable = &sn->pnettable;

        rc = -EINVAL;
        if (!tb[SMC_PNETID_NAME])
                goto error;
        string = (char *)nla_data(tb[SMC_PNETID_NAME]);
        if (!smc_pnetid_valid(string, pnet_name))
                goto error;

        if (tb[SMC_PNETID_ETHNAME]) {
                string = (char *)nla_data(tb[SMC_PNETID_ETHNAME]);
                rc = smc_pnet_add_eth(pnettable, net, string, pnet_name);
                if (!rc)
                        new_netdev = true;
                else if (rc != -EEXIST)
                        goto error;
        }

        /* if this is not the initial namespace, stop here */
        if (net != &init_net)
                return new_netdev ? 0 : -EEXIST;

        rc = -EINVAL;
        if (tb[SMC_PNETID_IBNAME]) {
                string = (char *)nla_data(tb[SMC_PNETID_IBNAME]);
                string = strim(string);
                if (tb[SMC_PNETID_IBPORT]) {
                        ibport = nla_get_u8(tb[SMC_PNETID_IBPORT]);
                        if (ibport < 1 || ibport > SMC_MAX_PORTS)
                                goto error;
                }
                rc = smc_pnet_add_ib(pnettable, string, ibport, pnet_name);
                if (!rc)
                        new_ibdev = true;
                else if (rc != -EEXIST)
                        goto error;
        }
        return (new_netdev || new_ibdev) ? 0 : -EEXIST;

error:
        return rc;
}

/* Convert an smc_pnetentry to a netlink attribute sequence */
static int smc_pnet_set_nla(struct sk_buff *msg,
                            struct smc_pnetentry *pnetelem)
{
        if (nla_put_string(msg, SMC_PNETID_NAME, pnetelem->pnet_name))
                return -1;
        if (pnetelem->type == SMC_PNET_ETH) {
                if (nla_put_string(msg, SMC_PNETID_ETHNAME,
                                   pnetelem->eth_name))
                        return -1;
        } else {
                if (nla_put_string(msg, SMC_PNETID_ETHNAME, "n/a"))
                        return -1;
        }
        if (pnetelem->type == SMC_PNET_IB) {
                if (nla_put_string(msg, SMC_PNETID_IBNAME, pnetelem->ib_name) ||
                    nla_put_u8(msg, SMC_PNETID_IBPORT, pnetelem->ib_port))
                        return -1;
        } else {
                if (nla_put_string(msg, SMC_PNETID_IBNAME, "n/a") ||
                    nla_put_u8(msg, SMC_PNETID_IBPORT, 0xff))
                        return -1;
        }

        return 0;
}

static int smc_pnet_add(struct sk_buff *skb, struct genl_info *info)
{
        struct net *net = genl_info_net(info);

        return smc_pnet_enter(net, info->attrs);
}

static int smc_pnet_del(struct sk_buff *skb, struct genl_info *info)
{
        struct net *net = genl_info_net(info);

        if (!info->attrs[SMC_PNETID_NAME])
                return -EINVAL;
        return smc_pnet_remove_by_pnetid(net,
                                (char *)nla_data(info->attrs[SMC_PNETID_NAME]));
}

static int smc_pnet_dump_start(struct netlink_callback *cb)
{
        cb->args[0] = 0;
        return 0;
}

static int smc_pnet_dumpinfo(struct sk_buff *skb,
                             u32 portid, u32 seq, u32 flags,
                             struct smc_pnetentry *pnetelem)
{
        void *hdr;

        hdr = genlmsg_put(skb, portid, seq, &smc_pnet_nl_family,
                          flags, SMC_PNETID_GET);
        if (!hdr)
                return -ENOMEM;
        if (smc_pnet_set_nla(skb, pnetelem) < 0) {
                genlmsg_cancel(skb, hdr);
                return -EMSGSIZE;
        }
        genlmsg_end(skb, hdr);
        return 0;
}

static int _smc_pnet_dump(struct net *net, struct sk_buff *skb, u32 portid,
                          u32 seq, u8 *pnetid, int start_idx)
{
        struct smc_pnettable *pnettable;
        struct smc_pnetentry *pnetelem;
        struct smc_net *sn;
        int idx = 0;

        /* get pnettable for namespace */
        sn = net_generic(net, smc_net_id);
        pnettable = &sn->pnettable;

        /* dump pnettable entries */
        mutex_lock(&pnettable->lock);
        list_for_each_entry(pnetelem, &pnettable->pnetlist, list) {
                if (pnetid && !smc_pnet_match(pnetelem->pnet_name, pnetid))
                        continue;
                if (idx++ < start_idx)
                        continue;
                /* if this is not the initial namespace, dump only netdev */
                if (net != &init_net && pnetelem->type != SMC_PNET_ETH)
                        continue;
                if (smc_pnet_dumpinfo(skb, portid, seq, NLM_F_MULTI,
                                      pnetelem)) {
                        --idx;
                        break;
                }
        }
        mutex_unlock(&pnettable->lock);
        return idx;
}

static int smc_pnet_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
        struct net *net = sock_net(skb->sk);
        int idx;

        idx = _smc_pnet_dump(net, skb, NETLINK_CB(cb->skb).portid,
                             cb->nlh->nlmsg_seq, NULL, cb->args[0]);

        cb->args[0] = idx;
        return skb->len;
}

/* Retrieve one PNETID entry */
static int smc_pnet_get(struct sk_buff *skb, struct genl_info *info)
{
        struct net *net = genl_info_net(info);
        struct sk_buff *msg;
        void *hdr;

        if (!info->attrs[SMC_PNETID_NAME])
                return -EINVAL;

        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (!msg)
                return -ENOMEM;

        _smc_pnet_dump(net, msg, info->snd_portid, info->snd_seq,
                       nla_data(info->attrs[SMC_PNETID_NAME]), 0);

        /* finish multi part message and send it */
        hdr = nlmsg_put(msg, info->snd_portid, info->snd_seq, NLMSG_DONE, 0,
                        NLM_F_MULTI);
        if (!hdr) {
                nlmsg_free(msg);
                return -EMSGSIZE;
        }
        return genlmsg_reply(msg, info);
}

/* Remove and delete all pnetids from pnet table.
 */
static int smc_pnet_flush(struct sk_buff *skb, struct genl_info *info)
{
        struct net *net = genl_info_net(info);

        smc_pnet_remove_by_pnetid(net, NULL);
        return 0;
}

/* SMC_PNETID generic netlink operation definition */
static const struct genl_ops smc_pnet_ops[] = {
        {
                .cmd = SMC_PNETID_GET,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                /* can be retrieved by unprivileged users */
                .doit = smc_pnet_get,
                .dumpit = smc_pnet_dump,
                .start = smc_pnet_dump_start
        },
        {
                .cmd = SMC_PNETID_ADD,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .flags = GENL_ADMIN_PERM,
                .doit = smc_pnet_add
        },
        {
                .cmd = SMC_PNETID_DEL,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .flags = GENL_ADMIN_PERM,
                .doit = smc_pnet_del
        },
        {
                .cmd = SMC_PNETID_FLUSH,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .flags = GENL_ADMIN_PERM,
                .doit = smc_pnet_flush
        }
};

/* SMC_PNETID family definition */
static struct genl_family smc_pnet_nl_family __ro_after_init = {
        .hdrsize = 0,
        .name = SMCR_GENL_FAMILY_NAME,
        .version = SMCR_GENL_FAMILY_VERSION,
        .maxattr = SMC_PNETID_MAX,
        .policy = smc_pnet_policy,
        .netnsok = true,
        .module = THIS_MODULE,
        .ops = smc_pnet_ops,
        .n_ops =  ARRAY_SIZE(smc_pnet_ops),
        .resv_start_op = SMC_PNETID_FLUSH + 1,
};

bool smc_pnet_is_ndev_pnetid(struct net *net, u8 *pnetid)
{
        struct smc_net *sn = net_generic(net, smc_net_id);
        struct smc_pnetids_ndev_entry *pe;
        bool rc = false;

        read_lock(&sn->pnetids_ndev.lock);
        list_for_each_entry(pe, &sn->pnetids_ndev.list, list) {
                if (smc_pnet_match(pnetid, pe->pnetid)) {
                        rc = true;
                        goto unlock;
                }
        }

unlock:
        read_unlock(&sn->pnetids_ndev.lock);
        return rc;
}

static int smc_pnet_add_pnetid(struct net *net, u8 *pnetid)
{
        struct smc_net *sn = net_generic(net, smc_net_id);
        struct smc_pnetids_ndev_entry *pe, *pi;

        pe = kzalloc_obj(*pe);
        if (!pe)
                return -ENOMEM;

        write_lock(&sn->pnetids_ndev.lock);
        list_for_each_entry(pi, &sn->pnetids_ndev.list, list) {
                if (smc_pnet_match(pnetid, pi->pnetid)) {
                        refcount_inc(&pi->refcnt);
                        kfree(pe);
                        goto unlock;
                }
        }
        refcount_set(&pe->refcnt, 1);
        memcpy(pe->pnetid, pnetid, SMC_MAX_PNETID_LEN);
        list_add_tail(&pe->list, &sn->pnetids_ndev.list);

unlock:
        write_unlock(&sn->pnetids_ndev.lock);
        return 0;
}

static void smc_pnet_remove_pnetid(struct net *net, u8 *pnetid)
{
        struct smc_net *sn = net_generic(net, smc_net_id);
        struct smc_pnetids_ndev_entry *pe, *pe2;

        write_lock(&sn->pnetids_ndev.lock);
        list_for_each_entry_safe(pe, pe2, &sn->pnetids_ndev.list, list) {
                if (smc_pnet_match(pnetid, pe->pnetid)) {
                        if (refcount_dec_and_test(&pe->refcnt)) {
                                list_del(&pe->list);
                                kfree(pe);
                        }
                        break;
                }
        }
        write_unlock(&sn->pnetids_ndev.lock);
}

static void smc_pnet_add_base_pnetid(struct net *net, struct net_device *dev,
                                     u8 *ndev_pnetid)
{
        struct net_device *base_dev;

        base_dev = __pnet_find_base_ndev(dev);
        if (base_dev->flags & IFF_UP &&
            !smc_pnetid_by_dev_port(base_dev->dev.parent, base_dev->dev_port,
                                    ndev_pnetid)) {
                /* add to PNETIDs list */
                smc_pnet_add_pnetid(net, ndev_pnetid);
        }
}

/* create initial list of netdevice pnetids */
static void smc_pnet_create_pnetids_list(struct net *net)
{
        u8 ndev_pnetid[SMC_MAX_PNETID_LEN];
        struct net_device *dev;

        /* Newly created netns do not have devices.
         * Do not even acquire rtnl.
         */
        if (list_empty(&net->dev_base_head))
                return;

        /* Note: This might not be needed, because smc_pnet_netdev_event()
         * is also calling smc_pnet_add_base_pnetid() when handling
         * NETDEV_UP event.
         */
        rtnl_lock();
        for_each_netdev(net, dev)
                smc_pnet_add_base_pnetid(net, dev, ndev_pnetid);
        rtnl_unlock();
}

/* clean up list of netdevice pnetids */
static void smc_pnet_destroy_pnetids_list(struct net *net)
{
        struct smc_net *sn = net_generic(net, smc_net_id);
        struct smc_pnetids_ndev_entry *pe, *temp_pe;

        write_lock(&sn->pnetids_ndev.lock);
        list_for_each_entry_safe(pe, temp_pe, &sn->pnetids_ndev.list, list) {
                list_del(&pe->list);
                kfree(pe);
        }
        write_unlock(&sn->pnetids_ndev.lock);
}

static int smc_pnet_netdev_event(struct notifier_block *this,
                                 unsigned long event, void *ptr)
{
        struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
        struct net *net = dev_net(event_dev);
        u8 ndev_pnetid[SMC_MAX_PNETID_LEN];

        switch (event) {
        case NETDEV_REBOOT:
        case NETDEV_UNREGISTER:
                smc_pnet_remove_by_ndev(event_dev);
                smc_ib_ndev_change(event_dev, event);
                return NOTIFY_OK;
        case NETDEV_REGISTER:
                smc_pnet_add_by_ndev(event_dev);
                smc_ib_ndev_change(event_dev, event);
                return NOTIFY_OK;
        case NETDEV_UP:
                smc_pnet_add_base_pnetid(net, event_dev, ndev_pnetid);
                return NOTIFY_OK;
        case NETDEV_DOWN:
                event_dev = __pnet_find_base_ndev(event_dev);
                if (!smc_pnetid_by_dev_port(event_dev->dev.parent,
                                            event_dev->dev_port, ndev_pnetid)) {
                        /* remove from PNETIDs list */
                        smc_pnet_remove_pnetid(net, ndev_pnetid);
                }
                return NOTIFY_OK;
        default:
                return NOTIFY_DONE;
        }
}

static struct notifier_block smc_netdev_notifier = {
        .notifier_call = smc_pnet_netdev_event
};

/* init network namespace */
int smc_pnet_net_init(struct net *net)
{
        struct smc_net *sn = net_generic(net, smc_net_id);
        struct smc_pnettable *pnettable = &sn->pnettable;
        struct smc_pnetids_ndev *pnetids_ndev = &sn->pnetids_ndev;

        INIT_LIST_HEAD(&pnettable->pnetlist);
        mutex_init(&pnettable->lock);
        INIT_LIST_HEAD(&pnetids_ndev->list);
        rwlock_init(&pnetids_ndev->lock);

        smc_pnet_create_pnetids_list(net);

        return 0;
}

int __init smc_pnet_init(void)
{
        int rc;

        rc = genl_register_family(&smc_pnet_nl_family);
        if (rc)
                return rc;
        rc = register_netdevice_notifier(&smc_netdev_notifier);
        if (rc)
                genl_unregister_family(&smc_pnet_nl_family);

        return rc;
}

/* exit network namespace */
void smc_pnet_net_exit(struct net *net)
{
        /* flush pnet table */
        smc_pnet_remove_by_pnetid(net, NULL);
        smc_pnet_destroy_pnetids_list(net);
}

void smc_pnet_exit(void)
{
        unregister_netdevice_notifier(&smc_netdev_notifier);
        genl_unregister_family(&smc_pnet_nl_family);
}

static struct net_device *__pnet_find_base_ndev(struct net_device *ndev)
{
        int i, nest_lvl;

        ASSERT_RTNL();
        nest_lvl = ndev->lower_level;
        for (i = 0; i < nest_lvl; i++) {
                struct list_head *lower = &ndev->adj_list.lower;

                if (list_empty(lower))
                        break;
                lower = lower->next;
                ndev = netdev_lower_get_next(ndev, &lower);
        }
        return ndev;
}

/* Determine one base device for stacked net devices.
 * If the lower device level contains more than one devices
 * (for instance with bonding slaves), just the first device
 * is used to reach a base device.
 */
static struct net_device *pnet_find_base_ndev(struct net_device *ndev)
{
        rtnl_lock();
        ndev = __pnet_find_base_ndev(ndev);
        rtnl_unlock();
        return ndev;
}

static int smc_pnet_find_ndev_pnetid_by_table(struct net_device *ndev,
                                              u8 *pnetid)
{
        struct smc_pnettable *pnettable;
        struct net *net = dev_net(ndev);
        struct smc_pnetentry *pnetelem;
        struct smc_net *sn;
        int rc = -ENOENT;

        /* get pnettable for namespace */
        sn = net_generic(net, smc_net_id);
        pnettable = &sn->pnettable;

        mutex_lock(&pnettable->lock);
        list_for_each_entry(pnetelem, &pnettable->pnetlist, list) {
                if (pnetelem->type == SMC_PNET_ETH && ndev == pnetelem->ndev) {
                        /* get pnetid of netdev device */
                        memcpy(pnetid, pnetelem->pnet_name, SMC_MAX_PNETID_LEN);
                        rc = 0;
                        break;
                }
        }
        mutex_unlock(&pnettable->lock);
        return rc;
}

static int smc_pnet_determine_gid(struct smc_ib_device *ibdev, int i,
                                  struct smc_init_info *ini)
{
        if (!ini->check_smcrv2 &&
            !smc_ib_determine_gid(ibdev, i, ini->vlan_id, ini->ib_gid, NULL,
                                  NULL)) {
                ini->ib_dev = ibdev;
                ini->ib_port = i;
                return 0;
        }
        if (ini->check_smcrv2 &&
            !smc_ib_determine_gid(ibdev, i, ini->vlan_id, ini->smcrv2.ib_gid_v2,
                                  NULL, &ini->smcrv2)) {
                ini->smcrv2.ib_dev_v2 = ibdev;
                ini->smcrv2.ib_port_v2 = i;
                return 0;
        }
        return -ENODEV;
}

/* find a roce device for the given pnetid */
static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
                                          struct smc_init_info *ini,
                                          struct smc_ib_device *known_dev,
                                          struct net *net)
{
        struct smc_ib_device *ibdev;
        int i;

        mutex_lock(&smc_ib_devices.mutex);
        list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
                if (ibdev == known_dev ||
                    !rdma_dev_access_netns(ibdev->ibdev, net))
                        continue;
                for (i = 1; i <= SMC_MAX_PORTS; i++) {
                        if (!rdma_is_port_valid(ibdev->ibdev, i))
                                continue;
                        if (smc_pnet_match(ibdev->pnetid[i - 1], pnet_id) &&
                            smc_ib_port_active(ibdev, i) &&
                            !test_bit(i - 1, ibdev->ports_going_away)) {
                                if (!smc_pnet_determine_gid(ibdev, i, ini))
                                        goto out;
                        }
                }
        }
out:
        mutex_unlock(&smc_ib_devices.mutex);
}

/* find alternate roce device with same pnet_id, vlan_id and net namespace */
void smc_pnet_find_alt_roce(struct smc_link_group *lgr,
                            struct smc_init_info *ini,
                            struct smc_ib_device *known_dev)
{
        struct net *net = lgr->net;

        _smc_pnet_find_roce_by_pnetid(lgr->pnet_id, ini, known_dev, net);
}

/* if handshake network device belongs to a roce device, return its
 * IB device and port
 */
static void smc_pnet_find_rdma_dev(struct net_device *netdev,
                                   struct smc_init_info *ini)
{
        struct net *net = dev_net(netdev);
        struct smc_ib_device *ibdev;

        mutex_lock(&smc_ib_devices.mutex);
        list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
                struct net_device *ndev;
                int i;

                /* check rdma net namespace */
                if (!rdma_dev_access_netns(ibdev->ibdev, net))
                        continue;

                for (i = 1; i <= SMC_MAX_PORTS; i++) {
                        if (!rdma_is_port_valid(ibdev->ibdev, i))
                                continue;
                        ndev = ib_device_get_netdev(ibdev->ibdev, i);
                        if (!ndev)
                                continue;
                        dev_put(ndev);
                        if (netdev == ndev &&
                            smc_ib_port_active(ibdev, i) &&
                            !test_bit(i - 1, ibdev->ports_going_away)) {
                                if (!smc_pnet_determine_gid(ibdev, i, ini))
                                        break;
                        }
                }
        }
        mutex_unlock(&smc_ib_devices.mutex);
}

/* Determine the corresponding IB device port based on the hardware PNETID.
 * Searching stops at the first matching active IB device port with vlan_id
 * configured.
 * If nothing found, check pnetid table.
 * If nothing found, try to use handshake device
 */
static void smc_pnet_find_roce_by_pnetid(struct net_device *ndev,
                                         struct smc_init_info *ini)
{
        u8 ndev_pnetid[SMC_MAX_PNETID_LEN];
        struct net_device *base_ndev;
        struct net *net;

        base_ndev = pnet_find_base_ndev(ndev);
        net = dev_net(ndev);
        if (smc_pnetid_by_dev_port(base_ndev->dev.parent, base_ndev->dev_port,
                                   ndev_pnetid) &&
            smc_pnet_find_ndev_pnetid_by_table(base_ndev, ndev_pnetid) &&
            smc_pnet_find_ndev_pnetid_by_table(ndev, ndev_pnetid)) {
                smc_pnet_find_rdma_dev(base_ndev, ini);
                return; /* pnetid could not be determined */
        }
        _smc_pnet_find_roce_by_pnetid(ndev_pnetid, ini, NULL, net);
}

static void smc_pnet_find_ism_by_pnetid(struct net_device *ndev,
                                        struct smc_init_info *ini)
{
        u8 ndev_pnetid[SMC_MAX_PNETID_LEN];
        struct smcd_dev *ismdev;

        ndev = pnet_find_base_ndev(ndev);
        if (smc_pnetid_by_dev_port(ndev->dev.parent, ndev->dev_port,
                                   ndev_pnetid) &&
            smc_pnet_find_ndev_pnetid_by_table(ndev, ndev_pnetid))
                return; /* pnetid could not be determined */

        mutex_lock(&smcd_dev_list.mutex);
        list_for_each_entry(ismdev, &smcd_dev_list.list, list) {
                if (smc_pnet_match(ismdev->pnetid, ndev_pnetid) &&
                    !ismdev->going_away &&
                    (!ini->ism_peer_gid[0].gid ||
                     !smc_ism_cantalk(&ini->ism_peer_gid[0], ini->vlan_id,
                                      ismdev))) {
                        ini->ism_dev[0] = ismdev;
                        break;
                }
        }
        mutex_unlock(&smcd_dev_list.mutex);
}

/* PNET table analysis for a given sock:
 * determine ib_device and port belonging to used internal TCP socket
 * ethernet interface.
 */
void smc_pnet_find_roce_resource(struct sock *sk, struct smc_init_info *ini)
{
        struct net_device *dev;
        struct dst_entry *dst;

        rcu_read_lock();
        dst = __sk_dst_get(sk);
        dev = dst ? dst_dev_rcu(dst) : NULL;
        dev_hold(dev);
        rcu_read_unlock();

        if (dev) {
                smc_pnet_find_roce_by_pnetid(dev, ini);
                dev_put(dev);
        }
}

void smc_pnet_find_ism_resource(struct sock *sk, struct smc_init_info *ini)
{
        struct net_device *dev;
        struct dst_entry *dst;

        ini->ism_dev[0] = NULL;

        rcu_read_lock();
        dst = __sk_dst_get(sk);
        dev = dst ? dst_dev_rcu(dst) : NULL;
        dev_hold(dev);
        rcu_read_unlock();

        if (dev) {
                smc_pnet_find_ism_by_pnetid(dev, ini);
                dev_put(dev);
        }
}

/* Lookup and apply a pnet table entry to the given ib device.
 */
int smc_pnetid_by_table_ib(struct smc_ib_device *smcibdev, u8 ib_port)
{
        char *ib_name = smcibdev->ibdev->name;
        struct smc_pnettable *pnettable;
        struct smc_pnetentry *tmp_pe;
        struct smc_net *sn;
        int rc = -ENOENT;

        /* get pnettable for init namespace */
        sn = net_generic(&init_net, smc_net_id);
        pnettable = &sn->pnettable;

        mutex_lock(&pnettable->lock);
        list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) {
                if (tmp_pe->type == SMC_PNET_IB &&
                    !strncmp(tmp_pe->ib_name, ib_name, IB_DEVICE_NAME_MAX) &&
                    tmp_pe->ib_port == ib_port) {
                        smc_pnet_apply_ib(smcibdev, ib_port, tmp_pe->pnet_name);
                        rc = 0;
                        break;
                }
        }
        mutex_unlock(&pnettable->lock);

        return rc;
}

/* Lookup and apply a pnet table entry to the given smcd device.
 */
int smc_pnetid_by_table_smcd(struct smcd_dev *smcddev)
{
        struct smc_pnettable *pnettable;
        struct smc_pnetentry *tmp_pe;
        struct smc_net *sn;
        int rc = -ENOENT;

        /* get pnettable for init namespace */
        sn = net_generic(&init_net, smc_net_id);
        pnettable = &sn->pnettable;

        mutex_lock(&pnettable->lock);
        list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) {
                if (tmp_pe->type == SMC_PNET_IB &&
                    (!strncmp(tmp_pe->ib_name,
                               dev_name(&smcddev->dibs->dev),
                               sizeof(tmp_pe->ib_name)) ||
                     (smcddev->dibs->dev.parent &&
                      !strncmp(tmp_pe->ib_name,
                               dev_name(smcddev->dibs->dev.parent),
                               sizeof(tmp_pe->ib_name))))) {
                        smc_pnet_apply_smcd(smcddev, tmp_pe->pnet_name);
                        rc = 0;
                        break;
                }
        }
        mutex_unlock(&pnettable->lock);

        return rc;
}