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 two 6 * licenses. You may choose to be licensed under the terms of the GNU 7 * General Public License (GPL) Version 2, available from the file 8 * COPYING in the main directory of this source tree, or the 9 * OpenIB.org BSD license below: 10 * 11 * Redistribution and use in source and binary forms, with or 12 * without modification, are permitted provided that the following 13 * conditions are met: 14 * 15 * - Redistributions of source code must retain the above 16 * copyright notice, this list of conditions and the following 17 * disclaimer. 18 * 19 * - Redistributions in binary form must reproduce the above 20 * copyright notice, this list of conditions and the following 21 * disclaimer in the documentation and/or other materials 22 * 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 OF 26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 31 * 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 45 static struct { 46 const struct rdma_nl_cbs *cb_table; 47 /* Synchronizes between ongoing netlink commands and netlink client 48 * unregistration. 49 */ 50 struct rw_semaphore sem; 51 } rdma_nl_types[RDMA_NL_NUM_CLIENTS]; 52 53 bool 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 } 59 EXPORT_SYMBOL(rdma_nl_chk_listeners); 60 61 static 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 new 71 * 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 81 static const struct rdma_nl_cbs * 82 get_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 in 88 * 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 module 97 * 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 } 110 111 void 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 } 121 EXPORT_SYMBOL(rdma_nl_register); 122 123 void 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 } 129 EXPORT_SYMBOL(rdma_nl_unregister); 130 131 void *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 } 139 EXPORT_SYMBOL(ibnl_put_msg); 140 141 int 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 } 150 EXPORT_SYMBOL(ibnl_put_attr); 151 152 static 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't 177 * 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); 196 done: 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_REQUEST 204 * flag. These messages are intended for RDMA_NL_LS consumer, so it is allowed 205 * for that consumer only. 206 */ 207 static 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 handled 226 * by the kernel, but RDMA_NL_LS is different, because it 227 * runs backward netlink scheme. Kernel initiates messages 228 * and waits for reply with data to keep pathrecord cache 229 * 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; 242 243 ack: 244 if (nlh->nlmsg_flags & NLM_F_ACK || err) 245 netlink_ack(skb, nlh, err, &extack); 246 247 skip: 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 } 256 257 static void rdma_nl_rcv(struct sk_buff *skb) 258 { 259 rdma_nl_rcv_skb(skb, &rdma_nl_rcv_msg); 260 } 261 262 int 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 } 270 EXPORT_SYMBOL(rdma_nl_unicast); 271 272 int 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 } 280 EXPORT_SYMBOL(rdma_nl_unicast_wait); 281 282 int 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 } 289 EXPORT_SYMBOL(rdma_nl_multicast); 290 291 void 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 } 298 299 void 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 } 308 309 int 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 }; 315 struct sock *nls; 316 317 nls = netlink_kernel_create(net, NETLINK_RDMA, &cfg); 318 if (!nls) 319 return -ENOMEM; 320 321 nls->sk_sndtimeo = 10 * HZ; 322 rnet->nl_sock = nls; 323 return 0; 324 } 325 326 void rdma_nl_net_exit(struct rdma_dev_net *rnet) 327 { 328 netlink_kernel_release(rnet->nl_sock); 329 } 330 331 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_RDMA); 332