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- /*
- * Copyright (c) 2017 Mellanox Technologies Inc. All rights reserved.
- * Copyright (c) 2010 Voltaire Inc. All rights reserved.
- *
- * This software is available to you under a choice of one of two
- * licenses. You may choose to be licensed under the terms of the GNU
- * General Public License (GPL) Version 2, available from the file
- * COPYING in the main directory of this source tree, or the
- * OpenIB.org BSD license below:
- *
- * Redistribution and use in source and binary forms, with or
- * without modification, are permitted provided that the following
- * conditions are met:
- *
- * - Redistributions of source code must retain the above
- * copyright notice, this list of conditions and the following
- * disclaimer.
- *
- * - Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following
- * disclaimer in the documentation and/or other materials
- * provided with the distribution.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
- * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
- #define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__
- #include <linux/export.h>
- #include <net/netlink.h>
- #include <net/net_namespace.h>
- #include <net/netns/generic.h>
- #include <net/sock.h>
- #include <rdma/rdma_netlink.h>
- #include <linux/module.h>
- #include "core_priv.h"
- static struct {
- const struct rdma_nl_cbs *cb_table;
- /* Synchronizes between ongoing netlink commands and netlink client
- * unregistration.
- */
- struct rw_semaphore sem;
- } rdma_nl_types[RDMA_NL_NUM_CLIENTS];
- bool rdma_nl_chk_listeners(unsigned int group)
- {
- struct rdma_dev_net *rnet = rdma_net_to_dev_net(&init_net);
- return netlink_has_listeners(rnet->nl_sock, group);
- }
- EXPORT_SYMBOL(rdma_nl_chk_listeners);
- static bool is_nl_msg_valid(unsigned int type, unsigned int op)
- {
- static const unsigned int max_num_ops[RDMA_NL_NUM_CLIENTS] = {
- [RDMA_NL_IWCM] = RDMA_NL_IWPM_NUM_OPS,
- [RDMA_NL_LS] = RDMA_NL_LS_NUM_OPS,
- [RDMA_NL_NLDEV] = RDMA_NLDEV_NUM_OPS,
- };
- /*
- * This BUILD_BUG_ON is intended to catch addition of new
- * RDMA netlink protocol without updating the array above.
- */
- BUILD_BUG_ON(RDMA_NL_NUM_CLIENTS != 6);
- if (type >= RDMA_NL_NUM_CLIENTS)
- return false;
- return (op < max_num_ops[type]) ? true : false;
- }
- static const struct rdma_nl_cbs *
- get_cb_table(const struct sk_buff *skb, unsigned int type, unsigned int op)
- {
- const struct rdma_nl_cbs *cb_table;
- /*
- * Currently only NLDEV client is supporting netlink commands in
- * non init_net net namespace.
- */
- if (sock_net(skb->sk) != &init_net && type != RDMA_NL_NLDEV)
- return NULL;
- cb_table = READ_ONCE(rdma_nl_types[type].cb_table);
- if (!cb_table) {
- /*
- * Didn't get valid reference of the table, attempt module
- * load once.
- */
- up_read(&rdma_nl_types[type].sem);
- request_module("rdma-netlink-subsys-%d", type);
- down_read(&rdma_nl_types[type].sem);
- cb_table = READ_ONCE(rdma_nl_types[type].cb_table);
- }
- if (!cb_table || (!cb_table[op].dump && !cb_table[op].doit))
- return NULL;
- return cb_table;
- }
- void rdma_nl_register(unsigned int index,
- const struct rdma_nl_cbs cb_table[])
- {
- if (WARN_ON(!is_nl_msg_valid(index, 0)) ||
- WARN_ON(READ_ONCE(rdma_nl_types[index].cb_table)))
- return;
- /* Pairs with the READ_ONCE in is_nl_valid() */
- smp_store_release(&rdma_nl_types[index].cb_table, cb_table);
- }
- EXPORT_SYMBOL(rdma_nl_register);
- void rdma_nl_unregister(unsigned int index)
- {
- down_write(&rdma_nl_types[index].sem);
- rdma_nl_types[index].cb_table = NULL;
- up_write(&rdma_nl_types[index].sem);
- }
- EXPORT_SYMBOL(rdma_nl_unregister);
- void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,
- int len, int client, int op, int flags)
- {
- *nlh = nlmsg_put(skb, 0, seq, RDMA_NL_GET_TYPE(client, op), len, flags);
- if (!*nlh)
- return NULL;
- return nlmsg_data(*nlh);
- }
- EXPORT_SYMBOL(ibnl_put_msg);
- int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
- int len, void *data, int type)
- {
- if (nla_put(skb, type, len, data)) {
- nlmsg_cancel(skb, nlh);
- return -EMSGSIZE;
- }
- return 0;
- }
- EXPORT_SYMBOL(ibnl_put_attr);
- static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
- struct netlink_ext_ack *extack)
- {
- int type = nlh->nlmsg_type;
- unsigned int index = RDMA_NL_GET_CLIENT(type);
- unsigned int op = RDMA_NL_GET_OP(type);
- const struct rdma_nl_cbs *cb_table;
- int err = -EINVAL;
- if (!is_nl_msg_valid(index, op))
- return -EINVAL;
- down_read(&rdma_nl_types[index].sem);
- cb_table = get_cb_table(skb, index, op);
- if (!cb_table)
- goto done;
- if ((cb_table[op].flags & RDMA_NL_ADMIN_PERM) &&
- !netlink_capable(skb, CAP_NET_ADMIN)) {
- err = -EPERM;
- goto done;
- }
- /*
- * LS responses overload the 0x100 (NLM_F_ROOT) flag. Don't
- * mistakenly call the .dump() function.
- */
- if (index == RDMA_NL_LS) {
- if (cb_table[op].doit)
- err = cb_table[op].doit(skb, nlh, extack);
- goto done;
- }
- /* FIXME: Convert IWCM to properly handle doit callbacks */
- if ((nlh->nlmsg_flags & NLM_F_DUMP) || index == RDMA_NL_IWCM) {
- struct netlink_dump_control c = {
- .dump = cb_table[op].dump,
- };
- if (c.dump)
- err = netlink_dump_start(skb->sk, skb, nlh, &c);
- goto done;
- }
- if (cb_table[op].doit)
- err = cb_table[op].doit(skb, nlh, extack);
- done:
- up_read(&rdma_nl_types[index].sem);
- return err;
- }
- /*
- * This function is similar to netlink_rcv_skb with one exception:
- * It calls to the callback for the netlink messages without NLM_F_REQUEST
- * flag. These messages are intended for RDMA_NL_LS consumer, so it is allowed
- * for that consumer only.
- */
- static int rdma_nl_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
- struct nlmsghdr *,
- struct netlink_ext_ack *))
- {
- struct netlink_ext_ack extack = {};
- struct nlmsghdr *nlh;
- int err;
- while (skb->len >= nlmsg_total_size(0)) {
- int msglen;
- nlh = nlmsg_hdr(skb);
- err = 0;
- if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
- return 0;
- /*
- * Generally speaking, the only requests are handled
- * by the kernel, but RDMA_NL_LS is different, because it
- * runs backward netlink scheme. Kernel initiates messages
- * and waits for reply with data to keep pathrecord cache
- * in sync.
- */
- if (!(nlh->nlmsg_flags & NLM_F_REQUEST) &&
- (RDMA_NL_GET_CLIENT(nlh->nlmsg_type) != RDMA_NL_LS))
- goto ack;
- /* Skip control messages */
- if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
- goto ack;
- err = cb(skb, nlh, &extack);
- if (err == -EINTR)
- goto skip;
- ack:
- if (nlh->nlmsg_flags & NLM_F_ACK || err)
- netlink_ack(skb, nlh, err, &extack);
- skip:
- msglen = NLMSG_ALIGN(nlh->nlmsg_len);
- if (msglen > skb->len)
- msglen = skb->len;
- skb_pull(skb, msglen);
- }
- return 0;
- }
- static void rdma_nl_rcv(struct sk_buff *skb)
- {
- rdma_nl_rcv_skb(skb, &rdma_nl_rcv_msg);
- }
- int rdma_nl_unicast(struct net *net, struct sk_buff *skb, u32 pid)
- {
- struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);
- int err;
- err = netlink_unicast(rnet->nl_sock, skb, pid, MSG_DONTWAIT);
- return (err < 0) ? err : 0;
- }
- EXPORT_SYMBOL(rdma_nl_unicast);
- int rdma_nl_unicast_wait(struct net *net, struct sk_buff *skb, __u32 pid)
- {
- struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);
- int err;
- err = netlink_unicast(rnet->nl_sock, skb, pid, 0);
- return (err < 0) ? err : 0;
- }
- EXPORT_SYMBOL(rdma_nl_unicast_wait);
- int rdma_nl_multicast(struct net *net, struct sk_buff *skb,
- unsigned int group, gfp_t flags)
- {
- struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);
- return nlmsg_multicast(rnet->nl_sock, skb, 0, group, flags);
- }
- EXPORT_SYMBOL(rdma_nl_multicast);
- void rdma_nl_init(void)
- {
- int idx;
- for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++)
- init_rwsem(&rdma_nl_types[idx].sem);
- }
- void rdma_nl_exit(void)
- {
- int idx;
- for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++)
- WARN(rdma_nl_types[idx].cb_table,
- "Netlink client %d wasn't released prior to unloading %s\n",
- idx, KBUILD_MODNAME);
- }
- int rdma_nl_net_init(struct rdma_dev_net *rnet)
- {
- struct net *net = read_pnet(&rnet->net);
- struct netlink_kernel_cfg cfg = {
- .input = rdma_nl_rcv,
- };
- struct sock *nls;
- nls = netlink_kernel_create(net, NETLINK_RDMA, &cfg);
- if (!nls)
- return -ENOMEM;
- nls->sk_sndtimeo = 10 * HZ;
- rnet->nl_sock = nls;
- return 0;
- }
- void rdma_nl_net_exit(struct rdma_dev_net *rnet)
- {
- netlink_kernel_release(rnet->nl_sock);
- }
- MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_RDMA);
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