Commit 16a47117 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Chuck Lever
Browse files

NFSD: add listener-{set,get} netlink command 



Introduce write_ports netlink command. For listener-set, userspace is
expected to provide a NFS listeners list it wants enabled. All other
sockets will be closed.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Co-developed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent cf619507

Documentation/netlink/specs/nfsd.yaml

+34 −0
Original line number Diff line number Diff line
@@ -98,6 +98,23 @@ attribute-sets: 
        type: nest

        nested-attributes: version

        multi-attr: true

  -

    name: sock

    attributes:

      -

        name: addr

        type: binary

      -

        name: transport-name

        type: string

  -

    name: server-sock

    attributes:

      -

        name: addr

        type: nest

        nested-attributes: sock

        multi-attr: true



operations:

  list:
@@ -163,3 +180,20 @@ operations: 
        reply:

          attributes:

            - version

    -

      name: listener-set

      doc: set nfs running sockets

      attribute-set: server-sock

      flags: [ admin-perm ]

      do:

        request:

          attributes:

            - addr

    -

      name: listener-get

      doc: get nfs running listeners

      attribute-set: server-sock

      do:

        reply:

          attributes:

            - addr

fs/nfsd/netlink.c

+22 −0
Original line number Diff line number Diff line
@@ -11,6 +11,11 @@ 
#include <uapi/linux/nfsd_netlink.h>



/* Common nested types */

const struct nla_policy nfsd_sock_nl_policy[NFSD_A_SOCK_TRANSPORT_NAME + 1] = {

	[NFSD_A_SOCK_ADDR] = { .type = NLA_BINARY, },

	[NFSD_A_SOCK_TRANSPORT_NAME] = { .type = NLA_NUL_STRING, },

};



const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1] = {

	[NFSD_A_VERSION_MAJOR] = { .type = NLA_U32, },

	[NFSD_A_VERSION_MINOR] = { .type = NLA_U32, },
@@ -30,6 +35,11 @@ static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_PROTO_VE 
	[NFSD_A_SERVER_PROTO_VERSION] = NLA_POLICY_NESTED(nfsd_version_nl_policy),

};



/* NFSD_CMD_LISTENER_SET - do */

static const struct nla_policy nfsd_listener_set_nl_policy[NFSD_A_SERVER_SOCK_ADDR + 1] = {

	[NFSD_A_SERVER_SOCK_ADDR] = NLA_POLICY_NESTED(nfsd_sock_nl_policy),

};



/* Ops table for nfsd */

static const struct genl_split_ops nfsd_nl_ops[] = {

	{
@@ -63,6 +73,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = { 
		.doit	= nfsd_nl_version_get_doit,

		.flags	= GENL_CMD_CAP_DO,

	},

	{

		.cmd		= NFSD_CMD_LISTENER_SET,

		.doit		= nfsd_nl_listener_set_doit,

		.policy		= nfsd_listener_set_nl_policy,

		.maxattr	= NFSD_A_SERVER_SOCK_ADDR,

		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,

	},

	{

		.cmd	= NFSD_CMD_LISTENER_GET,

		.doit	= nfsd_nl_listener_get_doit,

		.flags	= GENL_CMD_CAP_DO,

	},

};



struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h

+3 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <uapi/linux/nfsd_netlink.h>



/* Common nested types */

extern const struct nla_policy nfsd_sock_nl_policy[NFSD_A_SOCK_TRANSPORT_NAME + 1];

extern const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1];



int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb);
@@ -23,6 +24,8 @@ int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info); 
int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info);

int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);

int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info);

int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info);

int nfsd_nl_listener_get_doit(struct sk_buff *skb, struct genl_info *info);



extern struct genl_family nfsd_nl_family;

fs/nfsd/nfsctl.c

+220 −0
Original line number Diff line number Diff line
@@ -1946,6 +1946,226 @@ int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info) 
	return err;

}



/**

 * nfsd_nl_listener_set_doit - set the nfs running sockets

 * @skb: reply buffer

 * @info: netlink metadata and command arguments

 *

 * Return 0 on success or a negative errno.

 */

int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info)

{

	struct net *net = genl_info_net(info);

	struct svc_xprt *xprt, *tmp;

	const struct nlattr *attr;

	struct svc_serv *serv;

	LIST_HEAD(permsocks);

	struct nfsd_net *nn;

	int err, rem;



	mutex_lock(&nfsd_mutex);



	err = nfsd_create_serv(net);

	if (err) {

		mutex_unlock(&nfsd_mutex);

		return err;

	}



	nn = net_generic(net, nfsd_net_id);

	serv = nn->nfsd_serv;



	spin_lock_bh(&serv->sv_lock);



	/* Move all of the old listener sockets to a temp list */

	list_splice_init(&serv->sv_permsocks, &permsocks);



	/*

	 * Walk the list of server_socks from userland and move any that match

	 * back to sv_permsocks

	 */

	nlmsg_for_each_attr(attr, info->nlhdr, GENL_HDRLEN, rem) {

		struct nlattr *tb[NFSD_A_SOCK_MAX + 1];

		const char *xcl_name;

		struct sockaddr *sa;



		if (nla_type(attr) != NFSD_A_SERVER_SOCK_ADDR)

			continue;



		if (nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr,

				     nfsd_sock_nl_policy, info->extack) < 0)

			continue;



		if (!tb[NFSD_A_SOCK_ADDR] || !tb[NFSD_A_SOCK_TRANSPORT_NAME])

			continue;



		if (nla_len(tb[NFSD_A_SOCK_ADDR]) < sizeof(*sa))

			continue;



		xcl_name = nla_data(tb[NFSD_A_SOCK_TRANSPORT_NAME]);

		sa = nla_data(tb[NFSD_A_SOCK_ADDR]);



		/* Put back any matching sockets */

		list_for_each_entry_safe(xprt, tmp, &permsocks, xpt_list) {

			/* This shouldn't be possible */

			if (WARN_ON_ONCE(xprt->xpt_net != net)) {

				list_move(&xprt->xpt_list, &serv->sv_permsocks);

				continue;

			}



			/* If everything matches, put it back */

			if (!strcmp(xprt->xpt_class->xcl_name, xcl_name) &&

			    rpc_cmp_addr_port(sa, (struct sockaddr *)&xprt->xpt_local)) {

				list_move(&xprt->xpt_list, &serv->sv_permsocks);

				break;

			}

		}

	}



	/* For now, no removing old sockets while server is running */

	if (serv->sv_nrthreads && !list_empty(&permsocks)) {

		list_splice_init(&permsocks, &serv->sv_permsocks);

		spin_unlock_bh(&serv->sv_lock);

		err = -EBUSY;

		goto out_unlock_mtx;

	}



	/* Close the remaining sockets on the permsocks list */

	while (!list_empty(&permsocks)) {

		xprt = list_first_entry(&permsocks, struct svc_xprt, xpt_list);

		list_move(&xprt->xpt_list, &serv->sv_permsocks);



		/*

		 * Newly-created sockets are born with the BUSY bit set. Clear

		 * it if there are no threads, since nothing can pick it up

		 * in that case.

		 */

		if (!serv->sv_nrthreads)

			clear_bit(XPT_BUSY, &xprt->xpt_flags);



		set_bit(XPT_CLOSE, &xprt->xpt_flags);

		spin_unlock_bh(&serv->sv_lock);

		svc_xprt_close(xprt);

		spin_lock_bh(&serv->sv_lock);

	}



	spin_unlock_bh(&serv->sv_lock);



	/* walk list of addrs again, open any that still don't exist */

	nlmsg_for_each_attr(attr, info->nlhdr, GENL_HDRLEN, rem) {

		struct nlattr *tb[NFSD_A_SOCK_MAX + 1];

		const char *xcl_name;

		struct sockaddr *sa;

		int ret;



		if (nla_type(attr) != NFSD_A_SERVER_SOCK_ADDR)

			continue;



		if (nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr,

				     nfsd_sock_nl_policy, info->extack) < 0)

			continue;



		if (!tb[NFSD_A_SOCK_ADDR] || !tb[NFSD_A_SOCK_TRANSPORT_NAME])

			continue;



		if (nla_len(tb[NFSD_A_SOCK_ADDR]) < sizeof(*sa))

			continue;



		xcl_name = nla_data(tb[NFSD_A_SOCK_TRANSPORT_NAME]);

		sa = nla_data(tb[NFSD_A_SOCK_ADDR]);



		xprt = svc_find_listener(serv, xcl_name, net, sa);

		if (xprt) {

			svc_xprt_put(xprt);

			continue;

		}



		ret = svc_xprt_create_from_sa(serv, xcl_name, net, sa,

					      SVC_SOCK_ANONYMOUS,

					      get_current_cred());

		/* always save the latest error */

		if (ret < 0)

			err = ret;

	}



	if (!serv->sv_nrthreads && list_empty(&nn->nfsd_serv->sv_permsocks))

		nfsd_destroy_serv(net);



out_unlock_mtx:

	mutex_unlock(&nfsd_mutex);



	return err;

}



/**

 * nfsd_nl_listener_get_doit - get the nfs running listeners

 * @skb: reply buffer

 * @info: netlink metadata and command arguments

 *

 * Return 0 on success or a negative errno.

 */

int nfsd_nl_listener_get_doit(struct sk_buff *skb, struct genl_info *info)

{

	struct svc_xprt *xprt;

	struct svc_serv *serv;

	struct nfsd_net *nn;

	void *hdr;

	int err;



	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!skb)

		return -ENOMEM;



	hdr = genlmsg_iput(skb, info);

	if (!hdr) {

		err = -EMSGSIZE;

		goto err_free_msg;

	}



	mutex_lock(&nfsd_mutex);

	nn = net_generic(genl_info_net(info), nfsd_net_id);



	/* no nfs server? Just send empty socket list */

	if (!nn->nfsd_serv)

		goto out_unlock_mtx;



	serv = nn->nfsd_serv;

	spin_lock_bh(&serv->sv_lock);

	list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {

		struct nlattr *attr;



		attr = nla_nest_start(skb, NFSD_A_SERVER_SOCK_ADDR);

		if (!attr) {

			err = -EINVAL;

			goto err_serv_unlock;

		}



		if (nla_put_string(skb, NFSD_A_SOCK_TRANSPORT_NAME,

				   xprt->xpt_class->xcl_name) ||

		    nla_put(skb, NFSD_A_SOCK_ADDR,

			    sizeof(struct sockaddr_storage),

			    &xprt->xpt_local)) {

			err = -EINVAL;

			goto err_serv_unlock;

		}



		nla_nest_end(skb, attr);

	}

	spin_unlock_bh(&serv->sv_lock);

out_unlock_mtx:

	mutex_unlock(&nfsd_mutex);

	genlmsg_end(skb, hdr);



	return genlmsg_reply(skb, info);



err_serv_unlock:

	spin_unlock_bh(&serv->sv_lock);

	mutex_unlock(&nfsd_mutex);

err_free_msg:

	nlmsg_free(skb);



	return err;

}



/**

 * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace

 * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h

+17 −0
Original line number Diff line number Diff line
@@ -55,12 +55,29 @@ enum { 
	NFSD_A_SERVER_PROTO_MAX = (__NFSD_A_SERVER_PROTO_MAX - 1)

};



enum {

	NFSD_A_SOCK_ADDR = 1,

	NFSD_A_SOCK_TRANSPORT_NAME,



	__NFSD_A_SOCK_MAX,

	NFSD_A_SOCK_MAX = (__NFSD_A_SOCK_MAX - 1)

};



enum {

	NFSD_A_SERVER_SOCK_ADDR = 1,



	__NFSD_A_SERVER_SOCK_MAX,

	NFSD_A_SERVER_SOCK_MAX = (__NFSD_A_SERVER_SOCK_MAX - 1)

};



enum {

	NFSD_CMD_RPC_STATUS_GET = 1,

	NFSD_CMD_THREADS_SET,

	NFSD_CMD_THREADS_GET,

	NFSD_CMD_VERSION_SET,

	NFSD_CMD_VERSION_GET,

	NFSD_CMD_LISTENER_SET,

	NFSD_CMD_LISTENER_GET,



	__NFSD_CMD_MAX,

	NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)