// 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;
  		};
  		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_dev;

  	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 */

  	write_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) {

  				dev_put(pnetelem->ndev);

  				pr_warn_ratelimited("smc: net device %s "
  						    "erased user defined "
  						    "pnetid %.16s
  ",
  						    pnetelem->eth_name,
  						    pnetelem->pnet_name);
  			}

  			kfree(pnetelem);
  			rc = 0;

  		}
  	}

  	write_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
  ",
  						    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_dev, &smcd_dev_list.list, list) {
  		if (smcd_dev->pnetid_by_user &&
  		    (!pnet_name ||
  		     smc_pnet_match(pnet_name, smcd_dev->pnetid))) {

  			pr_warn_ratelimited("smc: smcd device %s "
  					    "erased user defined pnetid "
  					    "%.16s
  ", dev_name(&smcd_dev->dev),
  					    smcd_dev->pnetid);

  			memset(smcd_dev->pnetid, 0, SMC_MAX_PNETID_LEN);
  			smcd_dev->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;
  
  	write_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)) {
  			dev_hold(ndev);
  			pnetelem->ndev = ndev;

  			rc = 0;

  			pr_warn_ratelimited("smc: adding net device %s with "
  					    "user defined pnetid %.16s
  ",
  					    pnetelem->eth_name,
  					    pnetelem->pnet_name);

  			break;
  		}
  	}

  	write_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;

  	write_lock(&pnettable->lock);
  	list_for_each_entry_safe(pnetelem, tmp_pe, &pnettable->pnetlist, list) {
  		if (pnetelem->type == SMC_PNET_ETH && pnetelem->ndev == ndev) {
  			dev_put(pnetelem->ndev);
  			pnetelem->ndev = NULL;
  			rc = 0;

  			pr_warn_ratelimited("smc: removing net device %s with "
  					    "user defined pnetid %.16s
  ",
  					    pnetelem->eth_name,
  					    pnetelem->pnet_name);

  			break;

  		}

  	}

  	write_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)) ||
  		    !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->dev), 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(sizeof(*new_pe), GFP_KERNEL);
  	if (!new_pe)
  		goto out_put;
  	new_pe->type = SMC_PNET_ETH;
  	memcpy(new_pe->pnet_name, pnet_name, SMC_MAX_PNETID_LEN);
  	strncpy(new_pe->eth_name, eth_name, IFNAMSIZ);
  	new_pe->ndev = ndev;
  
  	rc = -EEXIST;
  	new_netdev = true;
  	write_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) {
  		list_add_tail(&new_pe->list, &pnettable->pnetlist);
  		write_unlock(&pnettable->lock);
  	} else {
  		write_unlock(&pnettable->lock);
  		kfree(new_pe);
  		goto out_put;
  	}

  	if (ndev)
  		pr_warn_ratelimited("smc: net device %s "
  				    "applied user defined pnetid %.16s
  ",
  				    new_pe->eth_name, new_pe->pnet_name);

  	return 0;
  
  out_put:
  	if (ndev)
  		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_dev;
  	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
  ", ib_dev->ibdev->name,
  					    ib_port,
  					    ib_dev->pnetid[ib_port - 1]);
  	}

  	smcd_dev = smc_pnet_find_smcd(ib_name);

  	if (smcd_dev) {

  		smcddev_applied = smc_pnet_apply_smcd(smcd_dev, pnet_name);

  		if (smcddev_applied)
  			pr_warn_ratelimited("smc: smcd device %s "
  					    "applied user defined pnetid "
  					    "%.16s
  ", dev_name(&smcd_dev->dev),
  					    smcd_dev->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(sizeof(*new_pe), GFP_KERNEL);
  	if (!new_pe)
  		return -ENOMEM;
  	new_pe->type = SMC_PNET_IB;
  	memcpy(new_pe->pnet_name, pnet_name, SMC_MAX_PNETID_LEN);
  	strncpy(new_pe->ib_name, ib_name, IB_DEVICE_NAME_MAX);
  	new_pe->ib_port = ib_port;
  
  	new_ibdev = true;
  	write_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);
  		write_unlock(&pnettable->lock);
  	} else {
  		write_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 */

  	read_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;
  		}
  	}

  	read_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)
  };

  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(sizeof(*pe), GFP_KERNEL);
  	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, pe->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;
  
  	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);

  		return NOTIFY_OK;

  	case NETDEV_REGISTER:
  		smc_pnet_add_by_ndev(event_dev);
  		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);
  	rwlock_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;
  
  	read_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;
  		}
  	}

  	read_unlock(&pnettable->lock);

  	return rc;
  }

  /* 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 smc_ib_device *ibdev;
  	int i;
  
  	ini->ib_dev = NULL;

  	mutex_lock(&smc_ib_devices.mutex);

  	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {

  		if (ibdev == known_dev)
  			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) &&
  			    !smc_ib_determine_gid(ibdev, i, ini->vlan_id,
  						  ini->ib_gid, NULL)) {
  				ini->ib_dev = ibdev;
  				ini->ib_port = i;
  				goto out;
  			}
  		}
  	}
  out:

  	mutex_unlock(&smc_ib_devices.mutex);

  }

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

  /* 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 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;
  
  		for (i = 1; i <= SMC_MAX_PORTS; i++) {
  			if (!rdma_is_port_valid(ibdev->ibdev, i))
  				continue;
  			if (!ibdev->ibdev->ops.get_netdev)
  				continue;
  			ndev = ibdev->ibdev->ops.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) &&

  			    !smc_ib_determine_gid(ibdev, i, ini->vlan_id,
  						  ini->ib_gid, NULL)) {
  				ini->ib_dev = ibdev;
  				ini->ib_port = i;

  				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];

  
  	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)) {

  		smc_pnet_find_rdma_dev(ndev, ini);

  		return; /* pnetid could not be determined */

  	}

  	_smc_pnet_find_roce_by_pnetid(ndev_pnetid, ini, NULL);

  }

  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] ||
  		     !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 dst_entry *dst = sk_dst_get(sk);

  	ini->ib_dev = NULL;
  	ini->ib_port = 0;

  	if (!dst)
  		goto out;
  	if (!dst->dev)
  		goto out_rel;

  	smc_pnet_find_roce_by_pnetid(dst->dev, ini);

  out_rel:
  	dst_release(dst);

  out:
  	return;

  }

  void smc_pnet_find_ism_resource(struct sock *sk, struct smc_init_info *ini)

  {
  	struct dst_entry *dst = sk_dst_get(sk);

  	ini->ism_dev[0] = NULL;

  	if (!dst)
  		goto out;
  	if (!dst->dev)
  		goto out_rel;

  	smc_pnet_find_ism_by_pnetid(dst->dev, ini);

  
  out_rel:
  	dst_release(dst);
  out:
  	return;
  }

  
  /* 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;
  
  	read_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;
  		}
  	}
  	read_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)
  {
  	const char *ib_name = dev_name(&smcddev->dev);
  	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;
  
  	read_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)) {
  			smc_pnet_apply_smcd(smcddev, tmp_pe->pnet_name);
  			rc = 0;
  			break;
  		}
  	}
  	read_unlock(&pnettable->lock);
  
  	return rc;
  }