Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Kernel Connection Multiplexor |
| 3 | * |
| 4 | * Copyright (c) 2016 Tom Herbert <tom@herbertland.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 |
| 8 | * as published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 11 | #include <linux/bpf.h> |
| 12 | #include <linux/errno.h> |
| 13 | #include <linux/errqueue.h> |
| 14 | #include <linux/file.h> |
| 15 | #include <linux/in.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/net.h> |
| 19 | #include <linux/netdevice.h> |
| 20 | #include <linux/poll.h> |
| 21 | #include <linux/rculist.h> |
| 22 | #include <linux/skbuff.h> |
| 23 | #include <linux/socket.h> |
| 24 | #include <linux/uaccess.h> |
| 25 | #include <linux/workqueue.h> |
WANG Cong | c0338af | 2016-08-28 21:28:26 -0700 | [diff] [blame] | 26 | #include <linux/syscalls.h> |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 27 | #include <net/kcm.h> |
| 28 | #include <net/netns/generic.h> |
| 29 | #include <net/sock.h> |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 30 | #include <uapi/linux/kcm.h> |
| 31 | |
| 32 | unsigned int kcm_net_id; |
| 33 | |
| 34 | static struct kmem_cache *kcm_psockp __read_mostly; |
| 35 | static struct kmem_cache *kcm_muxp __read_mostly; |
| 36 | static struct workqueue_struct *kcm_wq; |
| 37 | |
| 38 | static inline struct kcm_sock *kcm_sk(const struct sock *sk) |
| 39 | { |
| 40 | return (struct kcm_sock *)sk; |
| 41 | } |
| 42 | |
| 43 | static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb) |
| 44 | { |
| 45 | return (struct kcm_tx_msg *)skb->cb; |
| 46 | } |
| 47 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 48 | static void report_csk_error(struct sock *csk, int err) |
| 49 | { |
| 50 | csk->sk_err = EPIPE; |
| 51 | csk->sk_error_report(csk); |
| 52 | } |
| 53 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 54 | static void kcm_abort_tx_psock(struct kcm_psock *psock, int err, |
| 55 | bool wakeup_kcm) |
| 56 | { |
| 57 | struct sock *csk = psock->sk; |
| 58 | struct kcm_mux *mux = psock->mux; |
| 59 | |
| 60 | /* Unrecoverable error in transmit */ |
| 61 | |
| 62 | spin_lock_bh(&mux->lock); |
| 63 | |
| 64 | if (psock->tx_stopped) { |
| 65 | spin_unlock_bh(&mux->lock); |
| 66 | return; |
| 67 | } |
| 68 | |
| 69 | psock->tx_stopped = 1; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 70 | KCM_STATS_INCR(psock->stats.tx_aborts); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 71 | |
| 72 | if (!psock->tx_kcm) { |
| 73 | /* Take off psocks_avail list */ |
| 74 | list_del(&psock->psock_avail_list); |
| 75 | } else if (wakeup_kcm) { |
| 76 | /* In this case psock is being aborted while outside of |
| 77 | * write_msgs and psock is reserved. Schedule tx_work |
| 78 | * to handle the failure there. Need to commit tx_stopped |
| 79 | * before queuing work. |
| 80 | */ |
| 81 | smp_mb(); |
| 82 | |
| 83 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); |
| 84 | } |
| 85 | |
| 86 | spin_unlock_bh(&mux->lock); |
| 87 | |
| 88 | /* Report error on lower socket */ |
| 89 | report_csk_error(csk, err); |
| 90 | } |
| 91 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 92 | /* RX mux lock held. */ |
| 93 | static void kcm_update_rx_mux_stats(struct kcm_mux *mux, |
| 94 | struct kcm_psock *psock) |
| 95 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 96 | STRP_STATS_ADD(mux->stats.rx_bytes, |
| 97 | psock->strp.stats.rx_bytes - |
| 98 | psock->saved_rx_bytes); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 99 | mux->stats.rx_msgs += |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 100 | psock->strp.stats.rx_msgs - psock->saved_rx_msgs; |
| 101 | psock->saved_rx_msgs = psock->strp.stats.rx_msgs; |
| 102 | psock->saved_rx_bytes = psock->strp.stats.rx_bytes; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 103 | } |
| 104 | |
| 105 | static void kcm_update_tx_mux_stats(struct kcm_mux *mux, |
| 106 | struct kcm_psock *psock) |
| 107 | { |
| 108 | KCM_STATS_ADD(mux->stats.tx_bytes, |
| 109 | psock->stats.tx_bytes - psock->saved_tx_bytes); |
| 110 | mux->stats.tx_msgs += |
| 111 | psock->stats.tx_msgs - psock->saved_tx_msgs; |
| 112 | psock->saved_tx_msgs = psock->stats.tx_msgs; |
| 113 | psock->saved_tx_bytes = psock->stats.tx_bytes; |
| 114 | } |
| 115 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 116 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); |
| 117 | |
| 118 | /* KCM is ready to receive messages on its queue-- either the KCM is new or |
| 119 | * has become unblocked after being blocked on full socket buffer. Queue any |
| 120 | * pending ready messages on a psock. RX mux lock held. |
| 121 | */ |
| 122 | static void kcm_rcv_ready(struct kcm_sock *kcm) |
| 123 | { |
| 124 | struct kcm_mux *mux = kcm->mux; |
| 125 | struct kcm_psock *psock; |
| 126 | struct sk_buff *skb; |
| 127 | |
| 128 | if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled)) |
| 129 | return; |
| 130 | |
| 131 | while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) { |
| 132 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
| 133 | /* Assuming buffer limit has been reached */ |
| 134 | skb_queue_head(&mux->rx_hold_queue, skb); |
| 135 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); |
| 136 | return; |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | while (!list_empty(&mux->psocks_ready)) { |
| 141 | psock = list_first_entry(&mux->psocks_ready, struct kcm_psock, |
| 142 | psock_ready_list); |
| 143 | |
| 144 | if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) { |
| 145 | /* Assuming buffer limit has been reached */ |
| 146 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); |
| 147 | return; |
| 148 | } |
| 149 | |
| 150 | /* Consumed the ready message on the psock. Schedule rx_work to |
| 151 | * get more messages. |
| 152 | */ |
| 153 | list_del(&psock->psock_ready_list); |
| 154 | psock->ready_rx_msg = NULL; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 155 | /* Commit clearing of ready_rx_msg for queuing work */ |
| 156 | smp_mb(); |
| 157 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 158 | strp_unpause(&psock->strp); |
| 159 | strp_check_rcv(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 160 | } |
| 161 | |
| 162 | /* Buffer limit is okay now, add to ready list */ |
| 163 | list_add_tail(&kcm->wait_rx_list, |
| 164 | &kcm->mux->kcm_rx_waiters); |
| 165 | kcm->rx_wait = true; |
| 166 | } |
| 167 | |
| 168 | static void kcm_rfree(struct sk_buff *skb) |
| 169 | { |
| 170 | struct sock *sk = skb->sk; |
| 171 | struct kcm_sock *kcm = kcm_sk(sk); |
| 172 | struct kcm_mux *mux = kcm->mux; |
| 173 | unsigned int len = skb->truesize; |
| 174 | |
| 175 | sk_mem_uncharge(sk, len); |
| 176 | atomic_sub(len, &sk->sk_rmem_alloc); |
| 177 | |
| 178 | /* For reading rx_wait and rx_psock without holding lock */ |
| 179 | smp_mb__after_atomic(); |
| 180 | |
| 181 | if (!kcm->rx_wait && !kcm->rx_psock && |
| 182 | sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) { |
| 183 | spin_lock_bh(&mux->rx_lock); |
| 184 | kcm_rcv_ready(kcm); |
| 185 | spin_unlock_bh(&mux->rx_lock); |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) |
| 190 | { |
| 191 | struct sk_buff_head *list = &sk->sk_receive_queue; |
| 192 | |
| 193 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
| 194 | return -ENOMEM; |
| 195 | |
| 196 | if (!sk_rmem_schedule(sk, skb, skb->truesize)) |
| 197 | return -ENOBUFS; |
| 198 | |
| 199 | skb->dev = NULL; |
| 200 | |
| 201 | skb_orphan(skb); |
| 202 | skb->sk = sk; |
| 203 | skb->destructor = kcm_rfree; |
| 204 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); |
| 205 | sk_mem_charge(sk, skb->truesize); |
| 206 | |
| 207 | skb_queue_tail(list, skb); |
| 208 | |
| 209 | if (!sock_flag(sk, SOCK_DEAD)) |
| 210 | sk->sk_data_ready(sk); |
| 211 | |
| 212 | return 0; |
| 213 | } |
| 214 | |
| 215 | /* Requeue received messages for a kcm socket to other kcm sockets. This is |
| 216 | * called with a kcm socket is receive disabled. |
| 217 | * RX mux lock held. |
| 218 | */ |
| 219 | static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head) |
| 220 | { |
| 221 | struct sk_buff *skb; |
| 222 | struct kcm_sock *kcm; |
| 223 | |
| 224 | while ((skb = __skb_dequeue(head))) { |
| 225 | /* Reset destructor to avoid calling kcm_rcv_ready */ |
| 226 | skb->destructor = sock_rfree; |
| 227 | skb_orphan(skb); |
| 228 | try_again: |
| 229 | if (list_empty(&mux->kcm_rx_waiters)) { |
| 230 | skb_queue_tail(&mux->rx_hold_queue, skb); |
| 231 | continue; |
| 232 | } |
| 233 | |
| 234 | kcm = list_first_entry(&mux->kcm_rx_waiters, |
| 235 | struct kcm_sock, wait_rx_list); |
| 236 | |
| 237 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
| 238 | /* Should mean socket buffer full */ |
| 239 | list_del(&kcm->wait_rx_list); |
| 240 | kcm->rx_wait = false; |
| 241 | |
| 242 | /* Commit rx_wait to read in kcm_free */ |
| 243 | smp_wmb(); |
| 244 | |
| 245 | goto try_again; |
| 246 | } |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | /* Lower sock lock held */ |
| 251 | static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock, |
| 252 | struct sk_buff *head) |
| 253 | { |
| 254 | struct kcm_mux *mux = psock->mux; |
| 255 | struct kcm_sock *kcm; |
| 256 | |
| 257 | WARN_ON(psock->ready_rx_msg); |
| 258 | |
| 259 | if (psock->rx_kcm) |
| 260 | return psock->rx_kcm; |
| 261 | |
| 262 | spin_lock_bh(&mux->rx_lock); |
| 263 | |
| 264 | if (psock->rx_kcm) { |
| 265 | spin_unlock_bh(&mux->rx_lock); |
| 266 | return psock->rx_kcm; |
| 267 | } |
| 268 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 269 | kcm_update_rx_mux_stats(mux, psock); |
| 270 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 271 | if (list_empty(&mux->kcm_rx_waiters)) { |
| 272 | psock->ready_rx_msg = head; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 273 | strp_pause(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 274 | list_add_tail(&psock->psock_ready_list, |
| 275 | &mux->psocks_ready); |
| 276 | spin_unlock_bh(&mux->rx_lock); |
| 277 | return NULL; |
| 278 | } |
| 279 | |
| 280 | kcm = list_first_entry(&mux->kcm_rx_waiters, |
| 281 | struct kcm_sock, wait_rx_list); |
| 282 | list_del(&kcm->wait_rx_list); |
| 283 | kcm->rx_wait = false; |
| 284 | |
| 285 | psock->rx_kcm = kcm; |
| 286 | kcm->rx_psock = psock; |
| 287 | |
| 288 | spin_unlock_bh(&mux->rx_lock); |
| 289 | |
| 290 | return kcm; |
| 291 | } |
| 292 | |
| 293 | static void kcm_done(struct kcm_sock *kcm); |
| 294 | |
| 295 | static void kcm_done_work(struct work_struct *w) |
| 296 | { |
| 297 | kcm_done(container_of(w, struct kcm_sock, done_work)); |
| 298 | } |
| 299 | |
| 300 | /* Lower sock held */ |
| 301 | static void unreserve_rx_kcm(struct kcm_psock *psock, |
| 302 | bool rcv_ready) |
| 303 | { |
| 304 | struct kcm_sock *kcm = psock->rx_kcm; |
| 305 | struct kcm_mux *mux = psock->mux; |
| 306 | |
| 307 | if (!kcm) |
| 308 | return; |
| 309 | |
| 310 | spin_lock_bh(&mux->rx_lock); |
| 311 | |
| 312 | psock->rx_kcm = NULL; |
| 313 | kcm->rx_psock = NULL; |
| 314 | |
| 315 | /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with |
| 316 | * kcm_rfree |
| 317 | */ |
| 318 | smp_mb(); |
| 319 | |
| 320 | if (unlikely(kcm->done)) { |
| 321 | spin_unlock_bh(&mux->rx_lock); |
| 322 | |
| 323 | /* Need to run kcm_done in a task since we need to qcquire |
| 324 | * callback locks which may already be held here. |
| 325 | */ |
| 326 | INIT_WORK(&kcm->done_work, kcm_done_work); |
| 327 | schedule_work(&kcm->done_work); |
| 328 | return; |
| 329 | } |
| 330 | |
| 331 | if (unlikely(kcm->rx_disabled)) { |
| 332 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); |
| 333 | } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) { |
| 334 | /* Check for degenerative race with rx_wait that all |
| 335 | * data was dequeued (accounted for in kcm_rfree). |
| 336 | */ |
| 337 | kcm_rcv_ready(kcm); |
| 338 | } |
| 339 | spin_unlock_bh(&mux->rx_lock); |
| 340 | } |
| 341 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 342 | /* Lower sock lock held */ |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 343 | static void psock_data_ready(struct sock *sk) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 344 | { |
| 345 | struct kcm_psock *psock; |
| 346 | |
| 347 | read_lock_bh(&sk->sk_callback_lock); |
| 348 | |
| 349 | psock = (struct kcm_psock *)sk->sk_user_data; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 350 | if (likely(psock)) |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 351 | strp_data_ready(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 352 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 353 | read_unlock_bh(&sk->sk_callback_lock); |
| 354 | } |
| 355 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 356 | /* Called with lower sock held */ |
| 357 | static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 358 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 359 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
| 360 | struct kcm_sock *kcm; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 361 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 362 | try_queue: |
| 363 | kcm = reserve_rx_kcm(psock, skb); |
| 364 | if (!kcm) { |
| 365 | /* Unable to reserve a KCM, message is held in psock and strp |
| 366 | * is paused. |
| 367 | */ |
| 368 | return; |
| 369 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 370 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 371 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
| 372 | /* Should mean socket buffer full */ |
| 373 | unreserve_rx_kcm(psock, false); |
| 374 | goto try_queue; |
| 375 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 376 | } |
| 377 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 378 | static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 379 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 380 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
| 381 | struct bpf_prog *prog = psock->bpf_prog; |
| 382 | |
| 383 | return (*prog->bpf_func)(skb, prog->insnsi); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 384 | } |
| 385 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 386 | static int kcm_read_sock_done(struct strparser *strp, int err) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 387 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 388 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
| 389 | |
| 390 | unreserve_rx_kcm(psock, true); |
| 391 | |
| 392 | return err; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 393 | } |
| 394 | |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 395 | static void psock_state_change(struct sock *sk) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 396 | { |
| 397 | /* TCP only does a POLLIN for a half close. Do a POLLHUP here |
| 398 | * since application will normally not poll with POLLIN |
| 399 | * on the TCP sockets. |
| 400 | */ |
| 401 | |
| 402 | report_csk_error(sk, EPIPE); |
| 403 | } |
| 404 | |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 405 | static void psock_write_space(struct sock *sk) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 406 | { |
| 407 | struct kcm_psock *psock; |
| 408 | struct kcm_mux *mux; |
| 409 | struct kcm_sock *kcm; |
| 410 | |
| 411 | read_lock_bh(&sk->sk_callback_lock); |
| 412 | |
| 413 | psock = (struct kcm_psock *)sk->sk_user_data; |
| 414 | if (unlikely(!psock)) |
| 415 | goto out; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 416 | mux = psock->mux; |
| 417 | |
| 418 | spin_lock_bh(&mux->lock); |
| 419 | |
| 420 | /* Check if the socket is reserved so someone is waiting for sending. */ |
| 421 | kcm = psock->tx_kcm; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 422 | if (kcm && !unlikely(kcm->tx_stopped)) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 423 | queue_work(kcm_wq, &kcm->tx_work); |
| 424 | |
| 425 | spin_unlock_bh(&mux->lock); |
| 426 | out: |
| 427 | read_unlock_bh(&sk->sk_callback_lock); |
| 428 | } |
| 429 | |
| 430 | static void unreserve_psock(struct kcm_sock *kcm); |
| 431 | |
| 432 | /* kcm sock is locked. */ |
| 433 | static struct kcm_psock *reserve_psock(struct kcm_sock *kcm) |
| 434 | { |
| 435 | struct kcm_mux *mux = kcm->mux; |
| 436 | struct kcm_psock *psock; |
| 437 | |
| 438 | psock = kcm->tx_psock; |
| 439 | |
| 440 | smp_rmb(); /* Must read tx_psock before tx_wait */ |
| 441 | |
| 442 | if (psock) { |
| 443 | WARN_ON(kcm->tx_wait); |
| 444 | if (unlikely(psock->tx_stopped)) |
| 445 | unreserve_psock(kcm); |
| 446 | else |
| 447 | return kcm->tx_psock; |
| 448 | } |
| 449 | |
| 450 | spin_lock_bh(&mux->lock); |
| 451 | |
| 452 | /* Check again under lock to see if psock was reserved for this |
| 453 | * psock via psock_unreserve. |
| 454 | */ |
| 455 | psock = kcm->tx_psock; |
| 456 | if (unlikely(psock)) { |
| 457 | WARN_ON(kcm->tx_wait); |
| 458 | spin_unlock_bh(&mux->lock); |
| 459 | return kcm->tx_psock; |
| 460 | } |
| 461 | |
| 462 | if (!list_empty(&mux->psocks_avail)) { |
| 463 | psock = list_first_entry(&mux->psocks_avail, |
| 464 | struct kcm_psock, |
| 465 | psock_avail_list); |
| 466 | list_del(&psock->psock_avail_list); |
| 467 | if (kcm->tx_wait) { |
| 468 | list_del(&kcm->wait_psock_list); |
| 469 | kcm->tx_wait = false; |
| 470 | } |
| 471 | kcm->tx_psock = psock; |
| 472 | psock->tx_kcm = kcm; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 473 | KCM_STATS_INCR(psock->stats.reserved); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 474 | } else if (!kcm->tx_wait) { |
| 475 | list_add_tail(&kcm->wait_psock_list, |
| 476 | &mux->kcm_tx_waiters); |
| 477 | kcm->tx_wait = true; |
| 478 | } |
| 479 | |
| 480 | spin_unlock_bh(&mux->lock); |
| 481 | |
| 482 | return psock; |
| 483 | } |
| 484 | |
| 485 | /* mux lock held */ |
| 486 | static void psock_now_avail(struct kcm_psock *psock) |
| 487 | { |
| 488 | struct kcm_mux *mux = psock->mux; |
| 489 | struct kcm_sock *kcm; |
| 490 | |
| 491 | if (list_empty(&mux->kcm_tx_waiters)) { |
| 492 | list_add_tail(&psock->psock_avail_list, |
| 493 | &mux->psocks_avail); |
| 494 | } else { |
| 495 | kcm = list_first_entry(&mux->kcm_tx_waiters, |
| 496 | struct kcm_sock, |
| 497 | wait_psock_list); |
| 498 | list_del(&kcm->wait_psock_list); |
| 499 | kcm->tx_wait = false; |
| 500 | psock->tx_kcm = kcm; |
| 501 | |
| 502 | /* Commit before changing tx_psock since that is read in |
| 503 | * reserve_psock before queuing work. |
| 504 | */ |
| 505 | smp_mb(); |
| 506 | |
| 507 | kcm->tx_psock = psock; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 508 | KCM_STATS_INCR(psock->stats.reserved); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 509 | queue_work(kcm_wq, &kcm->tx_work); |
| 510 | } |
| 511 | } |
| 512 | |
| 513 | /* kcm sock is locked. */ |
| 514 | static void unreserve_psock(struct kcm_sock *kcm) |
| 515 | { |
| 516 | struct kcm_psock *psock; |
| 517 | struct kcm_mux *mux = kcm->mux; |
| 518 | |
| 519 | spin_lock_bh(&mux->lock); |
| 520 | |
| 521 | psock = kcm->tx_psock; |
| 522 | |
| 523 | if (WARN_ON(!psock)) { |
| 524 | spin_unlock_bh(&mux->lock); |
| 525 | return; |
| 526 | } |
| 527 | |
| 528 | smp_rmb(); /* Read tx_psock before tx_wait */ |
| 529 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 530 | kcm_update_tx_mux_stats(mux, psock); |
| 531 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 532 | WARN_ON(kcm->tx_wait); |
| 533 | |
| 534 | kcm->tx_psock = NULL; |
| 535 | psock->tx_kcm = NULL; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 536 | KCM_STATS_INCR(psock->stats.unreserved); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 537 | |
| 538 | if (unlikely(psock->tx_stopped)) { |
| 539 | if (psock->done) { |
| 540 | /* Deferred free */ |
| 541 | list_del(&psock->psock_list); |
| 542 | mux->psocks_cnt--; |
| 543 | sock_put(psock->sk); |
| 544 | fput(psock->sk->sk_socket->file); |
| 545 | kmem_cache_free(kcm_psockp, psock); |
| 546 | } |
| 547 | |
| 548 | /* Don't put back on available list */ |
| 549 | |
| 550 | spin_unlock_bh(&mux->lock); |
| 551 | |
| 552 | return; |
| 553 | } |
| 554 | |
| 555 | psock_now_avail(psock); |
| 556 | |
| 557 | spin_unlock_bh(&mux->lock); |
| 558 | } |
| 559 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 560 | static void kcm_report_tx_retry(struct kcm_sock *kcm) |
| 561 | { |
| 562 | struct kcm_mux *mux = kcm->mux; |
| 563 | |
| 564 | spin_lock_bh(&mux->lock); |
| 565 | KCM_STATS_INCR(mux->stats.tx_retries); |
| 566 | spin_unlock_bh(&mux->lock); |
| 567 | } |
| 568 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 569 | /* Write any messages ready on the kcm socket. Called with kcm sock lock |
| 570 | * held. Return bytes actually sent or error. |
| 571 | */ |
| 572 | static int kcm_write_msgs(struct kcm_sock *kcm) |
| 573 | { |
| 574 | struct sock *sk = &kcm->sk; |
| 575 | struct kcm_psock *psock; |
| 576 | struct sk_buff *skb, *head; |
| 577 | struct kcm_tx_msg *txm; |
| 578 | unsigned short fragidx, frag_offset; |
| 579 | unsigned int sent, total_sent = 0; |
| 580 | int ret = 0; |
| 581 | |
| 582 | kcm->tx_wait_more = false; |
| 583 | psock = kcm->tx_psock; |
| 584 | if (unlikely(psock && psock->tx_stopped)) { |
| 585 | /* A reserved psock was aborted asynchronously. Unreserve |
| 586 | * it and we'll retry the message. |
| 587 | */ |
| 588 | unreserve_psock(kcm); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 589 | kcm_report_tx_retry(kcm); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 590 | if (skb_queue_empty(&sk->sk_write_queue)) |
| 591 | return 0; |
| 592 | |
| 593 | kcm_tx_msg(skb_peek(&sk->sk_write_queue))->sent = 0; |
| 594 | |
| 595 | } else if (skb_queue_empty(&sk->sk_write_queue)) { |
| 596 | return 0; |
| 597 | } |
| 598 | |
| 599 | head = skb_peek(&sk->sk_write_queue); |
| 600 | txm = kcm_tx_msg(head); |
| 601 | |
| 602 | if (txm->sent) { |
| 603 | /* Send of first skbuff in queue already in progress */ |
| 604 | if (WARN_ON(!psock)) { |
| 605 | ret = -EINVAL; |
| 606 | goto out; |
| 607 | } |
| 608 | sent = txm->sent; |
| 609 | frag_offset = txm->frag_offset; |
| 610 | fragidx = txm->fragidx; |
| 611 | skb = txm->frag_skb; |
| 612 | |
| 613 | goto do_frag; |
| 614 | } |
| 615 | |
| 616 | try_again: |
| 617 | psock = reserve_psock(kcm); |
| 618 | if (!psock) |
| 619 | goto out; |
| 620 | |
| 621 | do { |
| 622 | skb = head; |
| 623 | txm = kcm_tx_msg(head); |
| 624 | sent = 0; |
| 625 | |
| 626 | do_frag_list: |
| 627 | if (WARN_ON(!skb_shinfo(skb)->nr_frags)) { |
| 628 | ret = -EINVAL; |
| 629 | goto out; |
| 630 | } |
| 631 | |
| 632 | for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; |
| 633 | fragidx++) { |
| 634 | skb_frag_t *frag; |
| 635 | |
| 636 | frag_offset = 0; |
| 637 | do_frag: |
| 638 | frag = &skb_shinfo(skb)->frags[fragidx]; |
| 639 | if (WARN_ON(!frag->size)) { |
| 640 | ret = -EINVAL; |
| 641 | goto out; |
| 642 | } |
| 643 | |
| 644 | ret = kernel_sendpage(psock->sk->sk_socket, |
| 645 | frag->page.p, |
| 646 | frag->page_offset + frag_offset, |
| 647 | frag->size - frag_offset, |
| 648 | MSG_DONTWAIT); |
| 649 | if (ret <= 0) { |
| 650 | if (ret == -EAGAIN) { |
| 651 | /* Save state to try again when there's |
| 652 | * write space on the socket |
| 653 | */ |
| 654 | txm->sent = sent; |
| 655 | txm->frag_offset = frag_offset; |
| 656 | txm->fragidx = fragidx; |
| 657 | txm->frag_skb = skb; |
| 658 | |
| 659 | ret = 0; |
| 660 | goto out; |
| 661 | } |
| 662 | |
| 663 | /* Hard failure in sending message, abort this |
| 664 | * psock since it has lost framing |
| 665 | * synchonization and retry sending the |
| 666 | * message from the beginning. |
| 667 | */ |
| 668 | kcm_abort_tx_psock(psock, ret ? -ret : EPIPE, |
| 669 | true); |
| 670 | unreserve_psock(kcm); |
| 671 | |
| 672 | txm->sent = 0; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 673 | kcm_report_tx_retry(kcm); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 674 | ret = 0; |
| 675 | |
| 676 | goto try_again; |
| 677 | } |
| 678 | |
| 679 | sent += ret; |
| 680 | frag_offset += ret; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 681 | KCM_STATS_ADD(psock->stats.tx_bytes, ret); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 682 | if (frag_offset < frag->size) { |
| 683 | /* Not finished with this frag */ |
| 684 | goto do_frag; |
| 685 | } |
| 686 | } |
| 687 | |
| 688 | if (skb == head) { |
| 689 | if (skb_has_frag_list(skb)) { |
| 690 | skb = skb_shinfo(skb)->frag_list; |
| 691 | goto do_frag_list; |
| 692 | } |
| 693 | } else if (skb->next) { |
| 694 | skb = skb->next; |
| 695 | goto do_frag_list; |
| 696 | } |
| 697 | |
| 698 | /* Successfully sent the whole packet, account for it. */ |
| 699 | skb_dequeue(&sk->sk_write_queue); |
| 700 | kfree_skb(head); |
| 701 | sk->sk_wmem_queued -= sent; |
| 702 | total_sent += sent; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 703 | KCM_STATS_INCR(psock->stats.tx_msgs); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 704 | } while ((head = skb_peek(&sk->sk_write_queue))); |
| 705 | out: |
| 706 | if (!head) { |
| 707 | /* Done with all queued messages. */ |
| 708 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); |
| 709 | unreserve_psock(kcm); |
| 710 | } |
| 711 | |
| 712 | /* Check if write space is available */ |
| 713 | sk->sk_write_space(sk); |
| 714 | |
| 715 | return total_sent ? : ret; |
| 716 | } |
| 717 | |
| 718 | static void kcm_tx_work(struct work_struct *w) |
| 719 | { |
| 720 | struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work); |
| 721 | struct sock *sk = &kcm->sk; |
| 722 | int err; |
| 723 | |
| 724 | lock_sock(sk); |
| 725 | |
| 726 | /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx |
| 727 | * aborts |
| 728 | */ |
| 729 | err = kcm_write_msgs(kcm); |
| 730 | if (err < 0) { |
| 731 | /* Hard failure in write, report error on KCM socket */ |
| 732 | pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err); |
| 733 | report_csk_error(&kcm->sk, -err); |
| 734 | goto out; |
| 735 | } |
| 736 | |
| 737 | /* Primarily for SOCK_SEQPACKET sockets */ |
| 738 | if (likely(sk->sk_socket) && |
| 739 | test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { |
| 740 | clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 741 | sk->sk_write_space(sk); |
| 742 | } |
| 743 | |
| 744 | out: |
| 745 | release_sock(sk); |
| 746 | } |
| 747 | |
| 748 | static void kcm_push(struct kcm_sock *kcm) |
| 749 | { |
| 750 | if (kcm->tx_wait_more) |
| 751 | kcm_write_msgs(kcm); |
| 752 | } |
| 753 | |
Tom Herbert | f29698fc | 2016-03-07 14:11:09 -0800 | [diff] [blame] | 754 | static ssize_t kcm_sendpage(struct socket *sock, struct page *page, |
| 755 | int offset, size_t size, int flags) |
| 756 | |
| 757 | { |
| 758 | struct sock *sk = sock->sk; |
| 759 | struct kcm_sock *kcm = kcm_sk(sk); |
| 760 | struct sk_buff *skb = NULL, *head = NULL; |
| 761 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); |
| 762 | bool eor; |
| 763 | int err = 0; |
| 764 | int i; |
| 765 | |
| 766 | if (flags & MSG_SENDPAGE_NOTLAST) |
| 767 | flags |= MSG_MORE; |
| 768 | |
| 769 | /* No MSG_EOR from splice, only look at MSG_MORE */ |
| 770 | eor = !(flags & MSG_MORE); |
| 771 | |
| 772 | lock_sock(sk); |
| 773 | |
| 774 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
| 775 | |
| 776 | err = -EPIPE; |
| 777 | if (sk->sk_err) |
| 778 | goto out_error; |
| 779 | |
| 780 | if (kcm->seq_skb) { |
| 781 | /* Previously opened message */ |
| 782 | head = kcm->seq_skb; |
| 783 | skb = kcm_tx_msg(head)->last_skb; |
| 784 | i = skb_shinfo(skb)->nr_frags; |
| 785 | |
| 786 | if (skb_can_coalesce(skb, i, page, offset)) { |
| 787 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); |
| 788 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
| 789 | goto coalesced; |
| 790 | } |
| 791 | |
| 792 | if (i >= MAX_SKB_FRAGS) { |
| 793 | struct sk_buff *tskb; |
| 794 | |
| 795 | tskb = alloc_skb(0, sk->sk_allocation); |
| 796 | while (!tskb) { |
| 797 | kcm_push(kcm); |
| 798 | err = sk_stream_wait_memory(sk, &timeo); |
| 799 | if (err) |
| 800 | goto out_error; |
| 801 | } |
| 802 | |
| 803 | if (head == skb) |
| 804 | skb_shinfo(head)->frag_list = tskb; |
| 805 | else |
| 806 | skb->next = tskb; |
| 807 | |
| 808 | skb = tskb; |
| 809 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 810 | i = 0; |
| 811 | } |
| 812 | } else { |
| 813 | /* Call the sk_stream functions to manage the sndbuf mem. */ |
| 814 | if (!sk_stream_memory_free(sk)) { |
| 815 | kcm_push(kcm); |
| 816 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 817 | err = sk_stream_wait_memory(sk, &timeo); |
| 818 | if (err) |
| 819 | goto out_error; |
| 820 | } |
| 821 | |
| 822 | head = alloc_skb(0, sk->sk_allocation); |
| 823 | while (!head) { |
| 824 | kcm_push(kcm); |
| 825 | err = sk_stream_wait_memory(sk, &timeo); |
| 826 | if (err) |
| 827 | goto out_error; |
| 828 | } |
| 829 | |
| 830 | skb = head; |
| 831 | i = 0; |
| 832 | } |
| 833 | |
| 834 | get_page(page); |
| 835 | skb_fill_page_desc(skb, i, page, offset, size); |
| 836 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
| 837 | |
| 838 | coalesced: |
| 839 | skb->len += size; |
| 840 | skb->data_len += size; |
| 841 | skb->truesize += size; |
| 842 | sk->sk_wmem_queued += size; |
| 843 | sk_mem_charge(sk, size); |
| 844 | |
| 845 | if (head != skb) { |
| 846 | head->len += size; |
| 847 | head->data_len += size; |
| 848 | head->truesize += size; |
| 849 | } |
| 850 | |
| 851 | if (eor) { |
| 852 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); |
| 853 | |
| 854 | /* Message complete, queue it on send buffer */ |
| 855 | __skb_queue_tail(&sk->sk_write_queue, head); |
| 856 | kcm->seq_skb = NULL; |
| 857 | KCM_STATS_INCR(kcm->stats.tx_msgs); |
| 858 | |
| 859 | if (flags & MSG_BATCH) { |
| 860 | kcm->tx_wait_more = true; |
| 861 | } else if (kcm->tx_wait_more || not_busy) { |
| 862 | err = kcm_write_msgs(kcm); |
| 863 | if (err < 0) { |
| 864 | /* We got a hard error in write_msgs but have |
| 865 | * already queued this message. Report an error |
| 866 | * in the socket, but don't affect return value |
| 867 | * from sendmsg |
| 868 | */ |
| 869 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); |
| 870 | report_csk_error(&kcm->sk, -err); |
| 871 | } |
| 872 | } |
| 873 | } else { |
| 874 | /* Message not complete, save state */ |
| 875 | kcm->seq_skb = head; |
| 876 | kcm_tx_msg(head)->last_skb = skb; |
| 877 | } |
| 878 | |
| 879 | KCM_STATS_ADD(kcm->stats.tx_bytes, size); |
| 880 | |
| 881 | release_sock(sk); |
| 882 | return size; |
| 883 | |
| 884 | out_error: |
| 885 | kcm_push(kcm); |
| 886 | |
| 887 | err = sk_stream_error(sk, flags, err); |
| 888 | |
| 889 | /* make sure we wake any epoll edge trigger waiter */ |
| 890 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) |
| 891 | sk->sk_write_space(sk); |
| 892 | |
| 893 | release_sock(sk); |
| 894 | return err; |
| 895 | } |
| 896 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 897 | static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
| 898 | { |
| 899 | struct sock *sk = sock->sk; |
| 900 | struct kcm_sock *kcm = kcm_sk(sk); |
| 901 | struct sk_buff *skb = NULL, *head = NULL; |
| 902 | size_t copy, copied = 0; |
| 903 | long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
| 904 | int eor = (sock->type == SOCK_DGRAM) ? |
| 905 | !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR); |
| 906 | int err = -EPIPE; |
| 907 | |
| 908 | lock_sock(sk); |
| 909 | |
| 910 | /* Per tcp_sendmsg this should be in poll */ |
| 911 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
| 912 | |
| 913 | if (sk->sk_err) |
| 914 | goto out_error; |
| 915 | |
| 916 | if (kcm->seq_skb) { |
| 917 | /* Previously opened message */ |
| 918 | head = kcm->seq_skb; |
| 919 | skb = kcm_tx_msg(head)->last_skb; |
| 920 | goto start; |
| 921 | } |
| 922 | |
| 923 | /* Call the sk_stream functions to manage the sndbuf mem. */ |
| 924 | if (!sk_stream_memory_free(sk)) { |
| 925 | kcm_push(kcm); |
| 926 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 927 | err = sk_stream_wait_memory(sk, &timeo); |
| 928 | if (err) |
| 929 | goto out_error; |
| 930 | } |
| 931 | |
WANG Cong | 1409935 | 2017-02-07 12:59:47 -0800 | [diff] [blame] | 932 | if (msg_data_left(msg)) { |
| 933 | /* New message, alloc head skb */ |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 934 | head = alloc_skb(0, sk->sk_allocation); |
WANG Cong | 1409935 | 2017-02-07 12:59:47 -0800 | [diff] [blame] | 935 | while (!head) { |
| 936 | kcm_push(kcm); |
| 937 | err = sk_stream_wait_memory(sk, &timeo); |
| 938 | if (err) |
| 939 | goto out_error; |
| 940 | |
| 941 | head = alloc_skb(0, sk->sk_allocation); |
| 942 | } |
| 943 | |
| 944 | skb = head; |
| 945 | |
| 946 | /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling |
| 947 | * csum_and_copy_from_iter from skb_do_copy_data_nocache. |
| 948 | */ |
| 949 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 950 | } |
| 951 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 952 | start: |
| 953 | while (msg_data_left(msg)) { |
| 954 | bool merge = true; |
| 955 | int i = skb_shinfo(skb)->nr_frags; |
| 956 | struct page_frag *pfrag = sk_page_frag(sk); |
| 957 | |
| 958 | if (!sk_page_frag_refill(sk, pfrag)) |
| 959 | goto wait_for_memory; |
| 960 | |
| 961 | if (!skb_can_coalesce(skb, i, pfrag->page, |
| 962 | pfrag->offset)) { |
| 963 | if (i == MAX_SKB_FRAGS) { |
| 964 | struct sk_buff *tskb; |
| 965 | |
| 966 | tskb = alloc_skb(0, sk->sk_allocation); |
| 967 | if (!tskb) |
| 968 | goto wait_for_memory; |
| 969 | |
| 970 | if (head == skb) |
| 971 | skb_shinfo(head)->frag_list = tskb; |
| 972 | else |
| 973 | skb->next = tskb; |
| 974 | |
| 975 | skb = tskb; |
| 976 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 977 | continue; |
| 978 | } |
| 979 | merge = false; |
| 980 | } |
| 981 | |
| 982 | copy = min_t(int, msg_data_left(msg), |
| 983 | pfrag->size - pfrag->offset); |
| 984 | |
| 985 | if (!sk_wmem_schedule(sk, copy)) |
| 986 | goto wait_for_memory; |
| 987 | |
| 988 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, |
| 989 | pfrag->page, |
| 990 | pfrag->offset, |
| 991 | copy); |
| 992 | if (err) |
| 993 | goto out_error; |
| 994 | |
| 995 | /* Update the skb. */ |
| 996 | if (merge) { |
| 997 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
| 998 | } else { |
| 999 | skb_fill_page_desc(skb, i, pfrag->page, |
| 1000 | pfrag->offset, copy); |
| 1001 | get_page(pfrag->page); |
| 1002 | } |
| 1003 | |
| 1004 | pfrag->offset += copy; |
| 1005 | copied += copy; |
| 1006 | if (head != skb) { |
| 1007 | head->len += copy; |
| 1008 | head->data_len += copy; |
| 1009 | } |
| 1010 | |
| 1011 | continue; |
| 1012 | |
| 1013 | wait_for_memory: |
| 1014 | kcm_push(kcm); |
| 1015 | err = sk_stream_wait_memory(sk, &timeo); |
| 1016 | if (err) |
| 1017 | goto out_error; |
| 1018 | } |
| 1019 | |
| 1020 | if (eor) { |
| 1021 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); |
| 1022 | |
WANG Cong | 1409935 | 2017-02-07 12:59:47 -0800 | [diff] [blame] | 1023 | if (head) { |
| 1024 | /* Message complete, queue it on send buffer */ |
| 1025 | __skb_queue_tail(&sk->sk_write_queue, head); |
| 1026 | kcm->seq_skb = NULL; |
| 1027 | KCM_STATS_INCR(kcm->stats.tx_msgs); |
| 1028 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1029 | |
| 1030 | if (msg->msg_flags & MSG_BATCH) { |
| 1031 | kcm->tx_wait_more = true; |
| 1032 | } else if (kcm->tx_wait_more || not_busy) { |
| 1033 | err = kcm_write_msgs(kcm); |
| 1034 | if (err < 0) { |
| 1035 | /* We got a hard error in write_msgs but have |
| 1036 | * already queued this message. Report an error |
| 1037 | * in the socket, but don't affect return value |
| 1038 | * from sendmsg |
| 1039 | */ |
| 1040 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); |
| 1041 | report_csk_error(&kcm->sk, -err); |
| 1042 | } |
| 1043 | } |
| 1044 | } else { |
| 1045 | /* Message not complete, save state */ |
| 1046 | partial_message: |
WANG Cong | 90aa799 | 2017-02-13 11:13:16 -0800 | [diff] [blame] | 1047 | if (head) { |
| 1048 | kcm->seq_skb = head; |
| 1049 | kcm_tx_msg(head)->last_skb = skb; |
| 1050 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1051 | } |
| 1052 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1053 | KCM_STATS_ADD(kcm->stats.tx_bytes, copied); |
| 1054 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1055 | release_sock(sk); |
| 1056 | return copied; |
| 1057 | |
| 1058 | out_error: |
| 1059 | kcm_push(kcm); |
| 1060 | |
| 1061 | if (copied && sock->type == SOCK_SEQPACKET) { |
| 1062 | /* Wrote some bytes before encountering an |
| 1063 | * error, return partial success. |
| 1064 | */ |
| 1065 | goto partial_message; |
| 1066 | } |
| 1067 | |
| 1068 | if (head != kcm->seq_skb) |
| 1069 | kfree_skb(head); |
| 1070 | |
| 1071 | err = sk_stream_error(sk, msg->msg_flags, err); |
| 1072 | |
| 1073 | /* make sure we wake any epoll edge trigger waiter */ |
| 1074 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) |
| 1075 | sk->sk_write_space(sk); |
| 1076 | |
| 1077 | release_sock(sk); |
| 1078 | return err; |
| 1079 | } |
| 1080 | |
| 1081 | static struct sk_buff *kcm_wait_data(struct sock *sk, int flags, |
| 1082 | long timeo, int *err) |
| 1083 | { |
| 1084 | struct sk_buff *skb; |
| 1085 | |
| 1086 | while (!(skb = skb_peek(&sk->sk_receive_queue))) { |
| 1087 | if (sk->sk_err) { |
| 1088 | *err = sock_error(sk); |
| 1089 | return NULL; |
| 1090 | } |
| 1091 | |
| 1092 | if (sock_flag(sk, SOCK_DONE)) |
| 1093 | return NULL; |
| 1094 | |
| 1095 | if ((flags & MSG_DONTWAIT) || !timeo) { |
| 1096 | *err = -EAGAIN; |
| 1097 | return NULL; |
| 1098 | } |
| 1099 | |
| 1100 | sk_wait_data(sk, &timeo, NULL); |
| 1101 | |
| 1102 | /* Handle signals */ |
| 1103 | if (signal_pending(current)) { |
| 1104 | *err = sock_intr_errno(timeo); |
| 1105 | return NULL; |
| 1106 | } |
| 1107 | } |
| 1108 | |
| 1109 | return skb; |
| 1110 | } |
| 1111 | |
| 1112 | static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, |
| 1113 | size_t len, int flags) |
| 1114 | { |
| 1115 | struct sock *sk = sock->sk; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1116 | struct kcm_sock *kcm = kcm_sk(sk); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1117 | int err = 0; |
| 1118 | long timeo; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1119 | struct strp_rx_msg *rxm; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1120 | int copied = 0; |
| 1121 | struct sk_buff *skb; |
| 1122 | |
| 1123 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
| 1124 | |
| 1125 | lock_sock(sk); |
| 1126 | |
| 1127 | skb = kcm_wait_data(sk, flags, timeo, &err); |
| 1128 | if (!skb) |
| 1129 | goto out; |
| 1130 | |
| 1131 | /* Okay, have a message on the receive queue */ |
| 1132 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1133 | rxm = strp_rx_msg(skb); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1134 | |
| 1135 | if (len > rxm->full_len) |
| 1136 | len = rxm->full_len; |
| 1137 | |
| 1138 | err = skb_copy_datagram_msg(skb, rxm->offset, msg, len); |
| 1139 | if (err < 0) |
| 1140 | goto out; |
| 1141 | |
| 1142 | copied = len; |
| 1143 | if (likely(!(flags & MSG_PEEK))) { |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1144 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1145 | if (copied < rxm->full_len) { |
| 1146 | if (sock->type == SOCK_DGRAM) { |
| 1147 | /* Truncated message */ |
| 1148 | msg->msg_flags |= MSG_TRUNC; |
| 1149 | goto msg_finished; |
| 1150 | } |
| 1151 | rxm->offset += copied; |
| 1152 | rxm->full_len -= copied; |
| 1153 | } else { |
| 1154 | msg_finished: |
| 1155 | /* Finished with message */ |
| 1156 | msg->msg_flags |= MSG_EOR; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1157 | KCM_STATS_INCR(kcm->stats.rx_msgs); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1158 | skb_unlink(skb, &sk->sk_receive_queue); |
| 1159 | kfree_skb(skb); |
| 1160 | } |
| 1161 | } |
| 1162 | |
| 1163 | out: |
| 1164 | release_sock(sk); |
| 1165 | |
| 1166 | return copied ? : err; |
| 1167 | } |
| 1168 | |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1169 | static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, |
| 1170 | struct pipe_inode_info *pipe, size_t len, |
| 1171 | unsigned int flags) |
| 1172 | { |
| 1173 | struct sock *sk = sock->sk; |
| 1174 | struct kcm_sock *kcm = kcm_sk(sk); |
| 1175 | long timeo; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1176 | struct strp_rx_msg *rxm; |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1177 | int err = 0; |
WANG Cong | f1971a2 | 2016-05-17 14:05:49 -0700 | [diff] [blame] | 1178 | ssize_t copied; |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1179 | struct sk_buff *skb; |
| 1180 | |
| 1181 | /* Only support splice for SOCKSEQPACKET */ |
| 1182 | |
| 1183 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
| 1184 | |
| 1185 | lock_sock(sk); |
| 1186 | |
| 1187 | skb = kcm_wait_data(sk, flags, timeo, &err); |
| 1188 | if (!skb) |
| 1189 | goto err_out; |
| 1190 | |
| 1191 | /* Okay, have a message on the receive queue */ |
| 1192 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1193 | rxm = strp_rx_msg(skb); |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1194 | |
| 1195 | if (len > rxm->full_len) |
| 1196 | len = rxm->full_len; |
| 1197 | |
Al Viro | 2586926 | 2016-09-17 21:02:10 -0400 | [diff] [blame] | 1198 | copied = skb_splice_bits(skb, sk, rxm->offset, pipe, len, flags); |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1199 | if (copied < 0) { |
| 1200 | err = copied; |
| 1201 | goto err_out; |
| 1202 | } |
| 1203 | |
| 1204 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
| 1205 | |
| 1206 | rxm->offset += copied; |
| 1207 | rxm->full_len -= copied; |
| 1208 | |
| 1209 | /* We have no way to return MSG_EOR. If all the bytes have been |
| 1210 | * read we still leave the message in the receive socket buffer. |
| 1211 | * A subsequent recvmsg needs to be done to return MSG_EOR and |
| 1212 | * finish reading the message. |
| 1213 | */ |
| 1214 | |
| 1215 | release_sock(sk); |
| 1216 | |
| 1217 | return copied; |
| 1218 | |
| 1219 | err_out: |
| 1220 | release_sock(sk); |
| 1221 | |
| 1222 | return err; |
| 1223 | } |
| 1224 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1225 | /* kcm sock lock held */ |
| 1226 | static void kcm_recv_disable(struct kcm_sock *kcm) |
| 1227 | { |
| 1228 | struct kcm_mux *mux = kcm->mux; |
| 1229 | |
| 1230 | if (kcm->rx_disabled) |
| 1231 | return; |
| 1232 | |
| 1233 | spin_lock_bh(&mux->rx_lock); |
| 1234 | |
| 1235 | kcm->rx_disabled = 1; |
| 1236 | |
| 1237 | /* If a psock is reserved we'll do cleanup in unreserve */ |
| 1238 | if (!kcm->rx_psock) { |
| 1239 | if (kcm->rx_wait) { |
| 1240 | list_del(&kcm->wait_rx_list); |
| 1241 | kcm->rx_wait = false; |
| 1242 | } |
| 1243 | |
| 1244 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); |
| 1245 | } |
| 1246 | |
| 1247 | spin_unlock_bh(&mux->rx_lock); |
| 1248 | } |
| 1249 | |
| 1250 | /* kcm sock lock held */ |
| 1251 | static void kcm_recv_enable(struct kcm_sock *kcm) |
| 1252 | { |
| 1253 | struct kcm_mux *mux = kcm->mux; |
| 1254 | |
| 1255 | if (!kcm->rx_disabled) |
| 1256 | return; |
| 1257 | |
| 1258 | spin_lock_bh(&mux->rx_lock); |
| 1259 | |
| 1260 | kcm->rx_disabled = 0; |
| 1261 | kcm_rcv_ready(kcm); |
| 1262 | |
| 1263 | spin_unlock_bh(&mux->rx_lock); |
| 1264 | } |
| 1265 | |
| 1266 | static int kcm_setsockopt(struct socket *sock, int level, int optname, |
| 1267 | char __user *optval, unsigned int optlen) |
| 1268 | { |
| 1269 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1270 | int val, valbool; |
| 1271 | int err = 0; |
| 1272 | |
| 1273 | if (level != SOL_KCM) |
| 1274 | return -ENOPROTOOPT; |
| 1275 | |
| 1276 | if (optlen < sizeof(int)) |
| 1277 | return -EINVAL; |
| 1278 | |
| 1279 | if (get_user(val, (int __user *)optval)) |
| 1280 | return -EINVAL; |
| 1281 | |
| 1282 | valbool = val ? 1 : 0; |
| 1283 | |
| 1284 | switch (optname) { |
| 1285 | case KCM_RECV_DISABLE: |
| 1286 | lock_sock(&kcm->sk); |
| 1287 | if (valbool) |
| 1288 | kcm_recv_disable(kcm); |
| 1289 | else |
| 1290 | kcm_recv_enable(kcm); |
| 1291 | release_sock(&kcm->sk); |
| 1292 | break; |
| 1293 | default: |
| 1294 | err = -ENOPROTOOPT; |
| 1295 | } |
| 1296 | |
| 1297 | return err; |
| 1298 | } |
| 1299 | |
| 1300 | static int kcm_getsockopt(struct socket *sock, int level, int optname, |
| 1301 | char __user *optval, int __user *optlen) |
| 1302 | { |
| 1303 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1304 | int val, len; |
| 1305 | |
| 1306 | if (level != SOL_KCM) |
| 1307 | return -ENOPROTOOPT; |
| 1308 | |
| 1309 | if (get_user(len, optlen)) |
| 1310 | return -EFAULT; |
| 1311 | |
| 1312 | len = min_t(unsigned int, len, sizeof(int)); |
| 1313 | if (len < 0) |
| 1314 | return -EINVAL; |
| 1315 | |
| 1316 | switch (optname) { |
| 1317 | case KCM_RECV_DISABLE: |
| 1318 | val = kcm->rx_disabled; |
| 1319 | break; |
| 1320 | default: |
| 1321 | return -ENOPROTOOPT; |
| 1322 | } |
| 1323 | |
| 1324 | if (put_user(len, optlen)) |
| 1325 | return -EFAULT; |
| 1326 | if (copy_to_user(optval, &val, len)) |
| 1327 | return -EFAULT; |
| 1328 | return 0; |
| 1329 | } |
| 1330 | |
| 1331 | static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux) |
| 1332 | { |
| 1333 | struct kcm_sock *tkcm; |
| 1334 | struct list_head *head; |
| 1335 | int index = 0; |
| 1336 | |
| 1337 | /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so |
| 1338 | * we set sk_state, otherwise epoll_wait always returns right away with |
| 1339 | * POLLHUP |
| 1340 | */ |
| 1341 | kcm->sk.sk_state = TCP_ESTABLISHED; |
| 1342 | |
| 1343 | /* Add to mux's kcm sockets list */ |
| 1344 | kcm->mux = mux; |
| 1345 | spin_lock_bh(&mux->lock); |
| 1346 | |
| 1347 | head = &mux->kcm_socks; |
| 1348 | list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) { |
| 1349 | if (tkcm->index != index) |
| 1350 | break; |
| 1351 | head = &tkcm->kcm_sock_list; |
| 1352 | index++; |
| 1353 | } |
| 1354 | |
| 1355 | list_add(&kcm->kcm_sock_list, head); |
| 1356 | kcm->index = index; |
| 1357 | |
| 1358 | mux->kcm_socks_cnt++; |
| 1359 | spin_unlock_bh(&mux->lock); |
| 1360 | |
| 1361 | INIT_WORK(&kcm->tx_work, kcm_tx_work); |
| 1362 | |
| 1363 | spin_lock_bh(&mux->rx_lock); |
| 1364 | kcm_rcv_ready(kcm); |
| 1365 | spin_unlock_bh(&mux->rx_lock); |
| 1366 | } |
| 1367 | |
| 1368 | static int kcm_attach(struct socket *sock, struct socket *csock, |
| 1369 | struct bpf_prog *prog) |
| 1370 | { |
| 1371 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1372 | struct kcm_mux *mux = kcm->mux; |
| 1373 | struct sock *csk; |
| 1374 | struct kcm_psock *psock = NULL, *tpsock; |
| 1375 | struct list_head *head; |
| 1376 | int index = 0; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1377 | struct strp_callbacks cb; |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 1378 | int err; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1379 | |
| 1380 | csk = csock->sk; |
| 1381 | if (!csk) |
| 1382 | return -EINVAL; |
| 1383 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1384 | psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); |
| 1385 | if (!psock) |
| 1386 | return -ENOMEM; |
| 1387 | |
| 1388 | psock->mux = mux; |
| 1389 | psock->sk = csk; |
| 1390 | psock->bpf_prog = prog; |
Tom Herbert | 29152a3 | 2016-03-07 14:11:11 -0800 | [diff] [blame] | 1391 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1392 | cb.rcv_msg = kcm_rcv_strparser; |
| 1393 | cb.abort_parser = NULL; |
| 1394 | cb.parse_msg = kcm_parse_func_strparser; |
| 1395 | cb.read_sock_done = kcm_read_sock_done; |
Tom Herbert | 29152a3 | 2016-03-07 14:11:11 -0800 | [diff] [blame] | 1396 | |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 1397 | err = strp_init(&psock->strp, csk, &cb); |
| 1398 | if (err) { |
| 1399 | kmem_cache_free(kcm_psockp, psock); |
| 1400 | return err; |
| 1401 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1402 | |
| 1403 | sock_hold(csk); |
| 1404 | |
| 1405 | write_lock_bh(&csk->sk_callback_lock); |
| 1406 | psock->save_data_ready = csk->sk_data_ready; |
| 1407 | psock->save_write_space = csk->sk_write_space; |
| 1408 | psock->save_state_change = csk->sk_state_change; |
| 1409 | csk->sk_user_data = psock; |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 1410 | csk->sk_data_ready = psock_data_ready; |
| 1411 | csk->sk_write_space = psock_write_space; |
| 1412 | csk->sk_state_change = psock_state_change; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1413 | write_unlock_bh(&csk->sk_callback_lock); |
| 1414 | |
| 1415 | /* Finished initialization, now add the psock to the MUX. */ |
| 1416 | spin_lock_bh(&mux->lock); |
| 1417 | head = &mux->psocks; |
| 1418 | list_for_each_entry(tpsock, &mux->psocks, psock_list) { |
| 1419 | if (tpsock->index != index) |
| 1420 | break; |
| 1421 | head = &tpsock->psock_list; |
| 1422 | index++; |
| 1423 | } |
| 1424 | |
| 1425 | list_add(&psock->psock_list, head); |
| 1426 | psock->index = index; |
| 1427 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1428 | KCM_STATS_INCR(mux->stats.psock_attach); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1429 | mux->psocks_cnt++; |
| 1430 | psock_now_avail(psock); |
| 1431 | spin_unlock_bh(&mux->lock); |
| 1432 | |
| 1433 | /* Schedule RX work in case there are already bytes queued */ |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1434 | strp_check_rcv(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1435 | |
| 1436 | return 0; |
| 1437 | } |
| 1438 | |
| 1439 | static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info) |
| 1440 | { |
| 1441 | struct socket *csock; |
| 1442 | struct bpf_prog *prog; |
| 1443 | int err; |
| 1444 | |
| 1445 | csock = sockfd_lookup(info->fd, &err); |
| 1446 | if (!csock) |
| 1447 | return -ENOENT; |
| 1448 | |
Daniel Borkmann | 113214b | 2016-06-30 17:24:44 +0200 | [diff] [blame] | 1449 | prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1450 | if (IS_ERR(prog)) { |
| 1451 | err = PTR_ERR(prog); |
| 1452 | goto out; |
| 1453 | } |
| 1454 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1455 | err = kcm_attach(sock, csock, prog); |
| 1456 | if (err) { |
| 1457 | bpf_prog_put(prog); |
| 1458 | goto out; |
| 1459 | } |
| 1460 | |
| 1461 | /* Keep reference on file also */ |
| 1462 | |
| 1463 | return 0; |
| 1464 | out: |
| 1465 | fput(csock->file); |
| 1466 | return err; |
| 1467 | } |
| 1468 | |
| 1469 | static void kcm_unattach(struct kcm_psock *psock) |
| 1470 | { |
| 1471 | struct sock *csk = psock->sk; |
| 1472 | struct kcm_mux *mux = psock->mux; |
| 1473 | |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1474 | lock_sock(csk); |
| 1475 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1476 | /* Stop getting callbacks from TCP socket. After this there should |
| 1477 | * be no way to reserve a kcm for this psock. |
| 1478 | */ |
| 1479 | write_lock_bh(&csk->sk_callback_lock); |
| 1480 | csk->sk_user_data = NULL; |
| 1481 | csk->sk_data_ready = psock->save_data_ready; |
| 1482 | csk->sk_write_space = psock->save_write_space; |
| 1483 | csk->sk_state_change = psock->save_state_change; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1484 | strp_stop(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1485 | |
| 1486 | if (WARN_ON(psock->rx_kcm)) { |
| 1487 | write_unlock_bh(&csk->sk_callback_lock); |
| 1488 | return; |
| 1489 | } |
| 1490 | |
| 1491 | spin_lock_bh(&mux->rx_lock); |
| 1492 | |
| 1493 | /* Stop receiver activities. After this point psock should not be |
| 1494 | * able to get onto ready list either through callbacks or work. |
| 1495 | */ |
| 1496 | if (psock->ready_rx_msg) { |
| 1497 | list_del(&psock->psock_ready_list); |
| 1498 | kfree_skb(psock->ready_rx_msg); |
| 1499 | psock->ready_rx_msg = NULL; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1500 | KCM_STATS_INCR(mux->stats.rx_ready_drops); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1501 | } |
| 1502 | |
| 1503 | spin_unlock_bh(&mux->rx_lock); |
| 1504 | |
| 1505 | write_unlock_bh(&csk->sk_callback_lock); |
| 1506 | |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1507 | /* Call strp_done without sock lock */ |
| 1508 | release_sock(csk); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1509 | strp_done(&psock->strp); |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1510 | lock_sock(csk); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1511 | |
| 1512 | bpf_prog_put(psock->bpf_prog); |
| 1513 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1514 | spin_lock_bh(&mux->lock); |
| 1515 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1516 | aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1517 | save_strp_stats(&psock->strp, &mux->aggregate_strp_stats); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1518 | |
| 1519 | KCM_STATS_INCR(mux->stats.psock_unattach); |
| 1520 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1521 | if (psock->tx_kcm) { |
| 1522 | /* psock was reserved. Just mark it finished and we will clean |
| 1523 | * up in the kcm paths, we need kcm lock which can not be |
| 1524 | * acquired here. |
| 1525 | */ |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1526 | KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1527 | spin_unlock_bh(&mux->lock); |
| 1528 | |
| 1529 | /* We are unattaching a socket that is reserved. Abort the |
| 1530 | * socket since we may be out of sync in sending on it. We need |
| 1531 | * to do this without the mux lock. |
| 1532 | */ |
| 1533 | kcm_abort_tx_psock(psock, EPIPE, false); |
| 1534 | |
| 1535 | spin_lock_bh(&mux->lock); |
| 1536 | if (!psock->tx_kcm) { |
| 1537 | /* psock now unreserved in window mux was unlocked */ |
| 1538 | goto no_reserved; |
| 1539 | } |
| 1540 | psock->done = 1; |
| 1541 | |
| 1542 | /* Commit done before queuing work to process it */ |
| 1543 | smp_mb(); |
| 1544 | |
| 1545 | /* Queue tx work to make sure psock->done is handled */ |
| 1546 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); |
| 1547 | spin_unlock_bh(&mux->lock); |
| 1548 | } else { |
| 1549 | no_reserved: |
| 1550 | if (!psock->tx_stopped) |
| 1551 | list_del(&psock->psock_avail_list); |
| 1552 | list_del(&psock->psock_list); |
| 1553 | mux->psocks_cnt--; |
| 1554 | spin_unlock_bh(&mux->lock); |
| 1555 | |
| 1556 | sock_put(csk); |
| 1557 | fput(csk->sk_socket->file); |
| 1558 | kmem_cache_free(kcm_psockp, psock); |
| 1559 | } |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1560 | |
| 1561 | release_sock(csk); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1562 | } |
| 1563 | |
| 1564 | static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) |
| 1565 | { |
| 1566 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1567 | struct kcm_mux *mux = kcm->mux; |
| 1568 | struct kcm_psock *psock; |
| 1569 | struct socket *csock; |
| 1570 | struct sock *csk; |
| 1571 | int err; |
| 1572 | |
| 1573 | csock = sockfd_lookup(info->fd, &err); |
| 1574 | if (!csock) |
| 1575 | return -ENOENT; |
| 1576 | |
| 1577 | csk = csock->sk; |
| 1578 | if (!csk) { |
| 1579 | err = -EINVAL; |
| 1580 | goto out; |
| 1581 | } |
| 1582 | |
| 1583 | err = -ENOENT; |
| 1584 | |
| 1585 | spin_lock_bh(&mux->lock); |
| 1586 | |
| 1587 | list_for_each_entry(psock, &mux->psocks, psock_list) { |
| 1588 | if (psock->sk != csk) |
| 1589 | continue; |
| 1590 | |
| 1591 | /* Found the matching psock */ |
| 1592 | |
| 1593 | if (psock->unattaching || WARN_ON(psock->done)) { |
| 1594 | err = -EALREADY; |
| 1595 | break; |
| 1596 | } |
| 1597 | |
| 1598 | psock->unattaching = 1; |
| 1599 | |
| 1600 | spin_unlock_bh(&mux->lock); |
| 1601 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1602 | /* Lower socket lock should already be held */ |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1603 | kcm_unattach(psock); |
| 1604 | |
| 1605 | err = 0; |
| 1606 | goto out; |
| 1607 | } |
| 1608 | |
| 1609 | spin_unlock_bh(&mux->lock); |
| 1610 | |
| 1611 | out: |
| 1612 | fput(csock->file); |
| 1613 | return err; |
| 1614 | } |
| 1615 | |
| 1616 | static struct proto kcm_proto = { |
| 1617 | .name = "KCM", |
| 1618 | .owner = THIS_MODULE, |
| 1619 | .obj_size = sizeof(struct kcm_sock), |
| 1620 | }; |
| 1621 | |
| 1622 | /* Clone a kcm socket. */ |
| 1623 | static int kcm_clone(struct socket *osock, struct kcm_clone *info, |
| 1624 | struct socket **newsockp) |
| 1625 | { |
| 1626 | struct socket *newsock; |
| 1627 | struct sock *newsk; |
| 1628 | struct file *newfile; |
| 1629 | int err, newfd; |
| 1630 | |
| 1631 | err = -ENFILE; |
| 1632 | newsock = sock_alloc(); |
| 1633 | if (!newsock) |
| 1634 | goto out; |
| 1635 | |
| 1636 | newsock->type = osock->type; |
| 1637 | newsock->ops = osock->ops; |
| 1638 | |
| 1639 | __module_get(newsock->ops->owner); |
| 1640 | |
| 1641 | newfd = get_unused_fd_flags(0); |
| 1642 | if (unlikely(newfd < 0)) { |
| 1643 | err = newfd; |
| 1644 | goto out_fd_fail; |
| 1645 | } |
| 1646 | |
| 1647 | newfile = sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); |
| 1648 | if (unlikely(IS_ERR(newfile))) { |
| 1649 | err = PTR_ERR(newfile); |
| 1650 | goto out_sock_alloc_fail; |
| 1651 | } |
| 1652 | |
| 1653 | newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, |
| 1654 | &kcm_proto, true); |
| 1655 | if (!newsk) { |
| 1656 | err = -ENOMEM; |
| 1657 | goto out_sk_alloc_fail; |
| 1658 | } |
| 1659 | |
| 1660 | sock_init_data(newsock, newsk); |
| 1661 | init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); |
| 1662 | |
| 1663 | fd_install(newfd, newfile); |
| 1664 | *newsockp = newsock; |
| 1665 | info->fd = newfd; |
| 1666 | |
| 1667 | return 0; |
| 1668 | |
| 1669 | out_sk_alloc_fail: |
| 1670 | fput(newfile); |
| 1671 | out_sock_alloc_fail: |
| 1672 | put_unused_fd(newfd); |
| 1673 | out_fd_fail: |
| 1674 | sock_release(newsock); |
| 1675 | out: |
| 1676 | return err; |
| 1677 | } |
| 1678 | |
| 1679 | static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
| 1680 | { |
| 1681 | int err; |
| 1682 | |
| 1683 | switch (cmd) { |
| 1684 | case SIOCKCMATTACH: { |
| 1685 | struct kcm_attach info; |
| 1686 | |
| 1687 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) |
| 1688 | err = -EFAULT; |
| 1689 | |
| 1690 | err = kcm_attach_ioctl(sock, &info); |
| 1691 | |
| 1692 | break; |
| 1693 | } |
| 1694 | case SIOCKCMUNATTACH: { |
| 1695 | struct kcm_unattach info; |
| 1696 | |
| 1697 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) |
| 1698 | err = -EFAULT; |
| 1699 | |
| 1700 | err = kcm_unattach_ioctl(sock, &info); |
| 1701 | |
| 1702 | break; |
| 1703 | } |
| 1704 | case SIOCKCMCLONE: { |
| 1705 | struct kcm_clone info; |
| 1706 | struct socket *newsock = NULL; |
| 1707 | |
| 1708 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) |
| 1709 | err = -EFAULT; |
| 1710 | |
| 1711 | err = kcm_clone(sock, &info, &newsock); |
| 1712 | |
| 1713 | if (!err) { |
| 1714 | if (copy_to_user((void __user *)arg, &info, |
| 1715 | sizeof(info))) { |
| 1716 | err = -EFAULT; |
WANG Cong | c0338af | 2016-08-28 21:28:26 -0700 | [diff] [blame] | 1717 | sys_close(info.fd); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1718 | } |
| 1719 | } |
| 1720 | |
| 1721 | break; |
| 1722 | } |
| 1723 | default: |
| 1724 | err = -ENOIOCTLCMD; |
| 1725 | break; |
| 1726 | } |
| 1727 | |
| 1728 | return err; |
| 1729 | } |
| 1730 | |
| 1731 | static void free_mux(struct rcu_head *rcu) |
| 1732 | { |
| 1733 | struct kcm_mux *mux = container_of(rcu, |
| 1734 | struct kcm_mux, rcu); |
| 1735 | |
| 1736 | kmem_cache_free(kcm_muxp, mux); |
| 1737 | } |
| 1738 | |
| 1739 | static void release_mux(struct kcm_mux *mux) |
| 1740 | { |
| 1741 | struct kcm_net *knet = mux->knet; |
| 1742 | struct kcm_psock *psock, *tmp_psock; |
| 1743 | |
| 1744 | /* Release psocks */ |
| 1745 | list_for_each_entry_safe(psock, tmp_psock, |
| 1746 | &mux->psocks, psock_list) { |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1747 | if (!WARN_ON(psock->unattaching)) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1748 | kcm_unattach(psock); |
| 1749 | } |
| 1750 | |
| 1751 | if (WARN_ON(mux->psocks_cnt)) |
| 1752 | return; |
| 1753 | |
| 1754 | __skb_queue_purge(&mux->rx_hold_queue); |
| 1755 | |
| 1756 | mutex_lock(&knet->mutex); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1757 | aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats); |
| 1758 | aggregate_psock_stats(&mux->aggregate_psock_stats, |
| 1759 | &knet->aggregate_psock_stats); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1760 | aggregate_strp_stats(&mux->aggregate_strp_stats, |
| 1761 | &knet->aggregate_strp_stats); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1762 | list_del_rcu(&mux->kcm_mux_list); |
| 1763 | knet->count--; |
| 1764 | mutex_unlock(&knet->mutex); |
| 1765 | |
| 1766 | call_rcu(&mux->rcu, free_mux); |
| 1767 | } |
| 1768 | |
| 1769 | static void kcm_done(struct kcm_sock *kcm) |
| 1770 | { |
| 1771 | struct kcm_mux *mux = kcm->mux; |
| 1772 | struct sock *sk = &kcm->sk; |
| 1773 | int socks_cnt; |
| 1774 | |
| 1775 | spin_lock_bh(&mux->rx_lock); |
| 1776 | if (kcm->rx_psock) { |
| 1777 | /* Cleanup in unreserve_rx_kcm */ |
| 1778 | WARN_ON(kcm->done); |
| 1779 | kcm->rx_disabled = 1; |
| 1780 | kcm->done = 1; |
| 1781 | spin_unlock_bh(&mux->rx_lock); |
| 1782 | return; |
| 1783 | } |
| 1784 | |
| 1785 | if (kcm->rx_wait) { |
| 1786 | list_del(&kcm->wait_rx_list); |
| 1787 | kcm->rx_wait = false; |
| 1788 | } |
| 1789 | /* Move any pending receive messages to other kcm sockets */ |
| 1790 | requeue_rx_msgs(mux, &sk->sk_receive_queue); |
| 1791 | |
| 1792 | spin_unlock_bh(&mux->rx_lock); |
| 1793 | |
| 1794 | if (WARN_ON(sk_rmem_alloc_get(sk))) |
| 1795 | return; |
| 1796 | |
| 1797 | /* Detach from MUX */ |
| 1798 | spin_lock_bh(&mux->lock); |
| 1799 | |
| 1800 | list_del(&kcm->kcm_sock_list); |
| 1801 | mux->kcm_socks_cnt--; |
| 1802 | socks_cnt = mux->kcm_socks_cnt; |
| 1803 | |
| 1804 | spin_unlock_bh(&mux->lock); |
| 1805 | |
| 1806 | if (!socks_cnt) { |
| 1807 | /* We are done with the mux now. */ |
| 1808 | release_mux(mux); |
| 1809 | } |
| 1810 | |
| 1811 | WARN_ON(kcm->rx_wait); |
| 1812 | |
| 1813 | sock_put(&kcm->sk); |
| 1814 | } |
| 1815 | |
| 1816 | /* Called by kcm_release to close a KCM socket. |
| 1817 | * If this is the last KCM socket on the MUX, destroy the MUX. |
| 1818 | */ |
| 1819 | static int kcm_release(struct socket *sock) |
| 1820 | { |
| 1821 | struct sock *sk = sock->sk; |
| 1822 | struct kcm_sock *kcm; |
| 1823 | struct kcm_mux *mux; |
| 1824 | struct kcm_psock *psock; |
| 1825 | |
| 1826 | if (!sk) |
| 1827 | return 0; |
| 1828 | |
| 1829 | kcm = kcm_sk(sk); |
| 1830 | mux = kcm->mux; |
| 1831 | |
| 1832 | sock_orphan(sk); |
| 1833 | kfree_skb(kcm->seq_skb); |
| 1834 | |
| 1835 | lock_sock(sk); |
| 1836 | /* Purge queue under lock to avoid race condition with tx_work trying |
| 1837 | * to act when queue is nonempty. If tx_work runs after this point |
| 1838 | * it will just return. |
| 1839 | */ |
| 1840 | __skb_queue_purge(&sk->sk_write_queue); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1841 | |
| 1842 | /* Set tx_stopped. This is checked when psock is bound to a kcm and we |
| 1843 | * get a writespace callback. This prevents further work being queued |
| 1844 | * from the callback (unbinding the psock occurs after canceling work. |
| 1845 | */ |
| 1846 | kcm->tx_stopped = 1; |
| 1847 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1848 | release_sock(sk); |
| 1849 | |
| 1850 | spin_lock_bh(&mux->lock); |
| 1851 | if (kcm->tx_wait) { |
| 1852 | /* Take of tx_wait list, after this point there should be no way |
| 1853 | * that a psock will be assigned to this kcm. |
| 1854 | */ |
| 1855 | list_del(&kcm->wait_psock_list); |
| 1856 | kcm->tx_wait = false; |
| 1857 | } |
| 1858 | spin_unlock_bh(&mux->lock); |
| 1859 | |
| 1860 | /* Cancel work. After this point there should be no outside references |
| 1861 | * to the kcm socket. |
| 1862 | */ |
| 1863 | cancel_work_sync(&kcm->tx_work); |
| 1864 | |
| 1865 | lock_sock(sk); |
| 1866 | psock = kcm->tx_psock; |
| 1867 | if (psock) { |
| 1868 | /* A psock was reserved, so we need to kill it since it |
| 1869 | * may already have some bytes queued from a message. We |
| 1870 | * need to do this after removing kcm from tx_wait list. |
| 1871 | */ |
| 1872 | kcm_abort_tx_psock(psock, EPIPE, false); |
| 1873 | unreserve_psock(kcm); |
| 1874 | } |
| 1875 | release_sock(sk); |
| 1876 | |
| 1877 | WARN_ON(kcm->tx_wait); |
| 1878 | WARN_ON(kcm->tx_psock); |
| 1879 | |
| 1880 | sock->sk = NULL; |
| 1881 | |
| 1882 | kcm_done(kcm); |
| 1883 | |
| 1884 | return 0; |
| 1885 | } |
| 1886 | |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1887 | static const struct proto_ops kcm_dgram_ops = { |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1888 | .family = PF_KCM, |
| 1889 | .owner = THIS_MODULE, |
| 1890 | .release = kcm_release, |
| 1891 | .bind = sock_no_bind, |
| 1892 | .connect = sock_no_connect, |
| 1893 | .socketpair = sock_no_socketpair, |
| 1894 | .accept = sock_no_accept, |
| 1895 | .getname = sock_no_getname, |
| 1896 | .poll = datagram_poll, |
| 1897 | .ioctl = kcm_ioctl, |
| 1898 | .listen = sock_no_listen, |
| 1899 | .shutdown = sock_no_shutdown, |
| 1900 | .setsockopt = kcm_setsockopt, |
| 1901 | .getsockopt = kcm_getsockopt, |
| 1902 | .sendmsg = kcm_sendmsg, |
| 1903 | .recvmsg = kcm_recvmsg, |
| 1904 | .mmap = sock_no_mmap, |
Tom Herbert | f29698fc | 2016-03-07 14:11:09 -0800 | [diff] [blame] | 1905 | .sendpage = kcm_sendpage, |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1906 | }; |
| 1907 | |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1908 | static const struct proto_ops kcm_seqpacket_ops = { |
| 1909 | .family = PF_KCM, |
| 1910 | .owner = THIS_MODULE, |
| 1911 | .release = kcm_release, |
| 1912 | .bind = sock_no_bind, |
| 1913 | .connect = sock_no_connect, |
| 1914 | .socketpair = sock_no_socketpair, |
| 1915 | .accept = sock_no_accept, |
| 1916 | .getname = sock_no_getname, |
| 1917 | .poll = datagram_poll, |
| 1918 | .ioctl = kcm_ioctl, |
| 1919 | .listen = sock_no_listen, |
| 1920 | .shutdown = sock_no_shutdown, |
| 1921 | .setsockopt = kcm_setsockopt, |
| 1922 | .getsockopt = kcm_getsockopt, |
| 1923 | .sendmsg = kcm_sendmsg, |
| 1924 | .recvmsg = kcm_recvmsg, |
| 1925 | .mmap = sock_no_mmap, |
Tom Herbert | f29698fc | 2016-03-07 14:11:09 -0800 | [diff] [blame] | 1926 | .sendpage = kcm_sendpage, |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1927 | .splice_read = kcm_splice_read, |
| 1928 | }; |
| 1929 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1930 | /* Create proto operation for kcm sockets */ |
| 1931 | static int kcm_create(struct net *net, struct socket *sock, |
| 1932 | int protocol, int kern) |
| 1933 | { |
| 1934 | struct kcm_net *knet = net_generic(net, kcm_net_id); |
| 1935 | struct sock *sk; |
| 1936 | struct kcm_mux *mux; |
| 1937 | |
| 1938 | switch (sock->type) { |
| 1939 | case SOCK_DGRAM: |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1940 | sock->ops = &kcm_dgram_ops; |
| 1941 | break; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1942 | case SOCK_SEQPACKET: |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1943 | sock->ops = &kcm_seqpacket_ops; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1944 | break; |
| 1945 | default: |
| 1946 | return -ESOCKTNOSUPPORT; |
| 1947 | } |
| 1948 | |
| 1949 | if (protocol != KCMPROTO_CONNECTED) |
| 1950 | return -EPROTONOSUPPORT; |
| 1951 | |
| 1952 | sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern); |
| 1953 | if (!sk) |
| 1954 | return -ENOMEM; |
| 1955 | |
| 1956 | /* Allocate a kcm mux, shared between KCM sockets */ |
| 1957 | mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL); |
| 1958 | if (!mux) { |
| 1959 | sk_free(sk); |
| 1960 | return -ENOMEM; |
| 1961 | } |
| 1962 | |
| 1963 | spin_lock_init(&mux->lock); |
| 1964 | spin_lock_init(&mux->rx_lock); |
| 1965 | INIT_LIST_HEAD(&mux->kcm_socks); |
| 1966 | INIT_LIST_HEAD(&mux->kcm_rx_waiters); |
| 1967 | INIT_LIST_HEAD(&mux->kcm_tx_waiters); |
| 1968 | |
| 1969 | INIT_LIST_HEAD(&mux->psocks); |
| 1970 | INIT_LIST_HEAD(&mux->psocks_ready); |
| 1971 | INIT_LIST_HEAD(&mux->psocks_avail); |
| 1972 | |
| 1973 | mux->knet = knet; |
| 1974 | |
| 1975 | /* Add new MUX to list */ |
| 1976 | mutex_lock(&knet->mutex); |
| 1977 | list_add_rcu(&mux->kcm_mux_list, &knet->mux_list); |
| 1978 | knet->count++; |
| 1979 | mutex_unlock(&knet->mutex); |
| 1980 | |
| 1981 | skb_queue_head_init(&mux->rx_hold_queue); |
| 1982 | |
| 1983 | /* Init KCM socket */ |
| 1984 | sock_init_data(sock, sk); |
| 1985 | init_kcm_sock(kcm_sk(sk), mux); |
| 1986 | |
| 1987 | return 0; |
| 1988 | } |
| 1989 | |
| 1990 | static struct net_proto_family kcm_family_ops = { |
| 1991 | .family = PF_KCM, |
| 1992 | .create = kcm_create, |
| 1993 | .owner = THIS_MODULE, |
| 1994 | }; |
| 1995 | |
| 1996 | static __net_init int kcm_init_net(struct net *net) |
| 1997 | { |
| 1998 | struct kcm_net *knet = net_generic(net, kcm_net_id); |
| 1999 | |
| 2000 | INIT_LIST_HEAD_RCU(&knet->mux_list); |
| 2001 | mutex_init(&knet->mutex); |
| 2002 | |
| 2003 | return 0; |
| 2004 | } |
| 2005 | |
| 2006 | static __net_exit void kcm_exit_net(struct net *net) |
| 2007 | { |
| 2008 | struct kcm_net *knet = net_generic(net, kcm_net_id); |
| 2009 | |
| 2010 | /* All KCM sockets should be closed at this point, which should mean |
| 2011 | * that all multiplexors and psocks have been destroyed. |
| 2012 | */ |
| 2013 | WARN_ON(!list_empty(&knet->mux_list)); |
| 2014 | } |
| 2015 | |
| 2016 | static struct pernet_operations kcm_net_ops = { |
| 2017 | .init = kcm_init_net, |
| 2018 | .exit = kcm_exit_net, |
| 2019 | .id = &kcm_net_id, |
| 2020 | .size = sizeof(struct kcm_net), |
| 2021 | }; |
| 2022 | |
| 2023 | static int __init kcm_init(void) |
| 2024 | { |
| 2025 | int err = -ENOMEM; |
| 2026 | |
| 2027 | kcm_muxp = kmem_cache_create("kcm_mux_cache", |
| 2028 | sizeof(struct kcm_mux), 0, |
| 2029 | SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
| 2030 | if (!kcm_muxp) |
| 2031 | goto fail; |
| 2032 | |
| 2033 | kcm_psockp = kmem_cache_create("kcm_psock_cache", |
| 2034 | sizeof(struct kcm_psock), 0, |
| 2035 | SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
| 2036 | if (!kcm_psockp) |
| 2037 | goto fail; |
| 2038 | |
| 2039 | kcm_wq = create_singlethread_workqueue("kkcmd"); |
| 2040 | if (!kcm_wq) |
| 2041 | goto fail; |
| 2042 | |
| 2043 | err = proto_register(&kcm_proto, 1); |
| 2044 | if (err) |
| 2045 | goto fail; |
| 2046 | |
| 2047 | err = sock_register(&kcm_family_ops); |
| 2048 | if (err) |
| 2049 | goto sock_register_fail; |
| 2050 | |
| 2051 | err = register_pernet_device(&kcm_net_ops); |
| 2052 | if (err) |
| 2053 | goto net_ops_fail; |
| 2054 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 2055 | err = kcm_proc_init(); |
| 2056 | if (err) |
| 2057 | goto proc_init_fail; |
| 2058 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2059 | return 0; |
| 2060 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 2061 | proc_init_fail: |
| 2062 | unregister_pernet_device(&kcm_net_ops); |
| 2063 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2064 | net_ops_fail: |
| 2065 | sock_unregister(PF_KCM); |
| 2066 | |
| 2067 | sock_register_fail: |
| 2068 | proto_unregister(&kcm_proto); |
| 2069 | |
| 2070 | fail: |
| 2071 | kmem_cache_destroy(kcm_muxp); |
| 2072 | kmem_cache_destroy(kcm_psockp); |
| 2073 | |
| 2074 | if (kcm_wq) |
| 2075 | destroy_workqueue(kcm_wq); |
| 2076 | |
| 2077 | return err; |
| 2078 | } |
| 2079 | |
| 2080 | static void __exit kcm_exit(void) |
| 2081 | { |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 2082 | kcm_proc_exit(); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2083 | unregister_pernet_device(&kcm_net_ops); |
| 2084 | sock_unregister(PF_KCM); |
| 2085 | proto_unregister(&kcm_proto); |
| 2086 | destroy_workqueue(kcm_wq); |
| 2087 | |
| 2088 | kmem_cache_destroy(kcm_muxp); |
| 2089 | kmem_cache_destroy(kcm_psockp); |
| 2090 | } |
| 2091 | |
| 2092 | module_init(kcm_init); |
| 2093 | module_exit(kcm_exit); |
| 2094 | |
| 2095 | MODULE_LICENSE("GPL"); |
| 2096 | MODULE_ALIAS_NETPROTO(PF_KCM); |
| 2097 | |