diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/infiniband/core/netlink.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c new file mode 100644 index 000000000..1b2cc9e45 --- /dev/null +++ b/drivers/infiniband/core/netlink.c @@ -0,0 +1,331 @@ +/* + * 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-%u", 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); |