333 lines · c
1/*2 * Copyright (c) 2017 Mellanox Technologies Inc. All rights reserved.3 * Copyright (c) 2010 Voltaire Inc. All rights reserved.4 *5 * This software is available to you under a choice of one of two6 * licenses. You may choose to be licensed under the terms of the GNU7 * General Public License (GPL) Version 2, available from the file8 * COPYING in the main directory of this source tree, or the9 * OpenIB.org BSD license below:10 *11 * Redistribution and use in source and binary forms, with or12 * without modification, are permitted provided that the following13 * conditions are met:14 *15 * - Redistributions of source code must retain the above16 * copyright notice, this list of conditions and the following17 * disclaimer.18 *19 * - Redistributions in binary form must reproduce the above20 * copyright notice, this list of conditions and the following21 * disclaimer in the documentation and/or other materials22 * provided with the distribution.23 *24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE31 * SOFTWARE.32 */33 34#define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__35 36#include <linux/export.h>37#include <net/netlink.h>38#include <net/net_namespace.h>39#include <net/netns/generic.h>40#include <net/sock.h>41#include <rdma/rdma_netlink.h>42#include <linux/module.h>43#include "core_priv.h"44 45static struct {46 const struct rdma_nl_cbs *cb_table;47 /* Synchronizes between ongoing netlink commands and netlink client48 * unregistration.49 */50 struct rw_semaphore sem;51} rdma_nl_types[RDMA_NL_NUM_CLIENTS];52 53bool rdma_nl_chk_listeners(unsigned int group)54{55 struct rdma_dev_net *rnet = rdma_net_to_dev_net(&init_net);56 57 return netlink_has_listeners(rnet->nl_sock, group);58}59EXPORT_SYMBOL(rdma_nl_chk_listeners);60 61static bool is_nl_msg_valid(unsigned int type, unsigned int op)62{63 static const unsigned int max_num_ops[RDMA_NL_NUM_CLIENTS] = {64 [RDMA_NL_IWCM] = RDMA_NL_IWPM_NUM_OPS,65 [RDMA_NL_LS] = RDMA_NL_LS_NUM_OPS,66 [RDMA_NL_NLDEV] = RDMA_NLDEV_NUM_OPS,67 };68 69 /*70 * This BUILD_BUG_ON is intended to catch addition of new71 * RDMA netlink protocol without updating the array above.72 */73 BUILD_BUG_ON(RDMA_NL_NUM_CLIENTS != 6);74 75 if (type >= RDMA_NL_NUM_CLIENTS)76 return false;77 78 return op < max_num_ops[type];79}80 81static const struct rdma_nl_cbs *82get_cb_table(const struct sk_buff *skb, unsigned int type, unsigned int op)83{84 const struct rdma_nl_cbs *cb_table;85 86 /*87 * Currently only NLDEV client is supporting netlink commands in88 * non init_net net namespace.89 */90 if (sock_net(skb->sk) != &init_net && type != RDMA_NL_NLDEV)91 return NULL;92 93 cb_table = READ_ONCE(rdma_nl_types[type].cb_table);94 if (!cb_table) {95 /*96 * Didn't get valid reference of the table, attempt module97 * load once.98 */99 up_read(&rdma_nl_types[type].sem);100 101 request_module("rdma-netlink-subsys-%u", type);102 103 down_read(&rdma_nl_types[type].sem);104 cb_table = READ_ONCE(rdma_nl_types[type].cb_table);105 }106 if (!cb_table || (!cb_table[op].dump && !cb_table[op].doit))107 return NULL;108 return cb_table;109}110 111void rdma_nl_register(unsigned int index,112 const struct rdma_nl_cbs cb_table[])113{114 if (WARN_ON(!is_nl_msg_valid(index, 0)) ||115 WARN_ON(READ_ONCE(rdma_nl_types[index].cb_table)))116 return;117 118 /* Pairs with the READ_ONCE in is_nl_valid() */119 smp_store_release(&rdma_nl_types[index].cb_table, cb_table);120}121EXPORT_SYMBOL(rdma_nl_register);122 123void rdma_nl_unregister(unsigned int index)124{125 down_write(&rdma_nl_types[index].sem);126 rdma_nl_types[index].cb_table = NULL;127 up_write(&rdma_nl_types[index].sem);128}129EXPORT_SYMBOL(rdma_nl_unregister);130 131void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,132 int len, int client, int op, int flags)133{134 *nlh = nlmsg_put(skb, 0, seq, RDMA_NL_GET_TYPE(client, op), len, flags);135 if (!*nlh)136 return NULL;137 return nlmsg_data(*nlh);138}139EXPORT_SYMBOL(ibnl_put_msg);140 141int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,142 int len, void *data, int type)143{144 if (nla_put(skb, type, len, data)) {145 nlmsg_cancel(skb, nlh);146 return -EMSGSIZE;147 }148 return 0;149}150EXPORT_SYMBOL(ibnl_put_attr);151 152static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,153 struct netlink_ext_ack *extack)154{155 int type = nlh->nlmsg_type;156 unsigned int index = RDMA_NL_GET_CLIENT(type);157 unsigned int op = RDMA_NL_GET_OP(type);158 const struct rdma_nl_cbs *cb_table;159 int err = -EINVAL;160 161 if (!is_nl_msg_valid(index, op))162 return -EINVAL;163 164 down_read(&rdma_nl_types[index].sem);165 cb_table = get_cb_table(skb, index, op);166 if (!cb_table)167 goto done;168 169 if ((cb_table[op].flags & RDMA_NL_ADMIN_PERM) &&170 !netlink_capable(skb, CAP_NET_ADMIN)) {171 err = -EPERM;172 goto done;173 }174 175 /*176 * LS responses overload the 0x100 (NLM_F_ROOT) flag. Don't177 * mistakenly call the .dump() function.178 */179 if (index == RDMA_NL_LS) {180 if (cb_table[op].doit)181 err = cb_table[op].doit(skb, nlh, extack);182 goto done;183 }184 /* FIXME: Convert IWCM to properly handle doit callbacks */185 if ((nlh->nlmsg_flags & NLM_F_DUMP) || index == RDMA_NL_IWCM) {186 struct netlink_dump_control c = {187 .dump = cb_table[op].dump,188 };189 if (c.dump)190 err = netlink_dump_start(skb->sk, skb, nlh, &c);191 goto done;192 }193 194 if (cb_table[op].doit)195 err = cb_table[op].doit(skb, nlh, extack);196done:197 up_read(&rdma_nl_types[index].sem);198 return err;199}200 201/*202 * This function is similar to netlink_rcv_skb with one exception:203 * It calls to the callback for the netlink messages without NLM_F_REQUEST204 * flag. These messages are intended for RDMA_NL_LS consumer, so it is allowed205 * for that consumer only.206 */207static int rdma_nl_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,208 struct nlmsghdr *,209 struct netlink_ext_ack *))210{211 struct netlink_ext_ack extack = {};212 struct nlmsghdr *nlh;213 int err;214 215 while (skb->len >= nlmsg_total_size(0)) {216 int msglen;217 218 nlh = nlmsg_hdr(skb);219 err = 0;220 221 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)222 return 0;223 224 /*225 * Generally speaking, the only requests are handled226 * by the kernel, but RDMA_NL_LS is different, because it227 * runs backward netlink scheme. Kernel initiates messages228 * and waits for reply with data to keep pathrecord cache229 * in sync.230 */231 if (!(nlh->nlmsg_flags & NLM_F_REQUEST) &&232 (RDMA_NL_GET_CLIENT(nlh->nlmsg_type) != RDMA_NL_LS))233 goto ack;234 235 /* Skip control messages */236 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)237 goto ack;238 239 err = cb(skb, nlh, &extack);240 if (err == -EINTR)241 goto skip;242 243ack:244 if (nlh->nlmsg_flags & NLM_F_ACK || err)245 netlink_ack(skb, nlh, err, &extack);246 247skip:248 msglen = NLMSG_ALIGN(nlh->nlmsg_len);249 if (msglen > skb->len)250 msglen = skb->len;251 skb_pull(skb, msglen);252 }253 254 return 0;255}256 257static void rdma_nl_rcv(struct sk_buff *skb)258{259 rdma_nl_rcv_skb(skb, &rdma_nl_rcv_msg);260}261 262int rdma_nl_unicast(struct net *net, struct sk_buff *skb, u32 pid)263{264 struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);265 int err;266 267 err = netlink_unicast(rnet->nl_sock, skb, pid, MSG_DONTWAIT);268 return (err < 0) ? err : 0;269}270EXPORT_SYMBOL(rdma_nl_unicast);271 272int rdma_nl_unicast_wait(struct net *net, struct sk_buff *skb, __u32 pid)273{274 struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);275 int err;276 277 err = netlink_unicast(rnet->nl_sock, skb, pid, 0);278 return (err < 0) ? err : 0;279}280EXPORT_SYMBOL(rdma_nl_unicast_wait);281 282int rdma_nl_multicast(struct net *net, struct sk_buff *skb,283 unsigned int group, gfp_t flags)284{285 struct rdma_dev_net *rnet = rdma_net_to_dev_net(net);286 287 return nlmsg_multicast(rnet->nl_sock, skb, 0, group, flags);288}289EXPORT_SYMBOL(rdma_nl_multicast);290 291void rdma_nl_init(void)292{293 int idx;294 295 for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++)296 init_rwsem(&rdma_nl_types[idx].sem);297}298 299void rdma_nl_exit(void)300{301 int idx;302 303 for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++)304 WARN(rdma_nl_types[idx].cb_table,305 "Netlink client %d wasn't released prior to unloading %s\n",306 idx, KBUILD_MODNAME);307}308 309int rdma_nl_net_init(struct rdma_dev_net *rnet)310{311 struct net *net = read_pnet(&rnet->net);312 struct netlink_kernel_cfg cfg = {313 .input = rdma_nl_rcv,314 .flags = NL_CFG_F_NONROOT_RECV,315 };316 struct sock *nls;317 318 nls = netlink_kernel_create(net, NETLINK_RDMA, &cfg);319 if (!nls)320 return -ENOMEM;321 322 nls->sk_sndtimeo = 10 * HZ;323 rnet->nl_sock = nls;324 return 0;325}326 327void rdma_nl_net_exit(struct rdma_dev_net *rnet)328{329 netlink_kernel_release(rnet->nl_sock);330}331 332MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_RDMA);333