Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 2 | /* |
| 3 | * Kernel Connection Multiplexor |
| 4 | * |
| 5 | * Copyright (c) 2016 Tom Herbert <[email protected]> |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 6 | */ |
| 7 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 8 | #include <linux/bpf.h> |
| 9 | #include <linux/errno.h> |
| 10 | #include <linux/errqueue.h> |
| 11 | #include <linux/file.h> |
| 12 | #include <linux/in.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/net.h> |
| 16 | #include <linux/netdevice.h> |
| 17 | #include <linux/poll.h> |
| 18 | #include <linux/rculist.h> |
| 19 | #include <linux/skbuff.h> |
| 20 | #include <linux/socket.h> |
| 21 | #include <linux/uaccess.h> |
| 22 | #include <linux/workqueue.h> |
WANG Cong | c0338af | 2016-08-28 21:28:26 -0700 | [diff] [blame] | 23 | #include <linux/syscalls.h> |
Ingo Molnar | 174cd4b | 2017-02-02 19:15:33 +0100 | [diff] [blame] | 24 | #include <linux/sched/signal.h> |
| 25 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 26 | #include <net/kcm.h> |
| 27 | #include <net/netns/generic.h> |
| 28 | #include <net/sock.h> |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 29 | #include <uapi/linux/kcm.h> |
| 30 | |
| 31 | unsigned int kcm_net_id; |
| 32 | |
| 33 | static struct kmem_cache *kcm_psockp __read_mostly; |
| 34 | static struct kmem_cache *kcm_muxp __read_mostly; |
| 35 | static struct workqueue_struct *kcm_wq; |
| 36 | |
| 37 | static inline struct kcm_sock *kcm_sk(const struct sock *sk) |
| 38 | { |
| 39 | return (struct kcm_sock *)sk; |
| 40 | } |
| 41 | |
| 42 | static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb) |
| 43 | { |
| 44 | return (struct kcm_tx_msg *)skb->cb; |
| 45 | } |
| 46 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 47 | static void report_csk_error(struct sock *csk, int err) |
| 48 | { |
| 49 | csk->sk_err = EPIPE; |
| 50 | csk->sk_error_report(csk); |
| 51 | } |
| 52 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 53 | static void kcm_abort_tx_psock(struct kcm_psock *psock, int err, |
| 54 | bool wakeup_kcm) |
| 55 | { |
| 56 | struct sock *csk = psock->sk; |
| 57 | struct kcm_mux *mux = psock->mux; |
| 58 | |
| 59 | /* Unrecoverable error in transmit */ |
| 60 | |
| 61 | spin_lock_bh(&mux->lock); |
| 62 | |
| 63 | if (psock->tx_stopped) { |
| 64 | spin_unlock_bh(&mux->lock); |
| 65 | return; |
| 66 | } |
| 67 | |
| 68 | psock->tx_stopped = 1; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 69 | KCM_STATS_INCR(psock->stats.tx_aborts); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 70 | |
| 71 | if (!psock->tx_kcm) { |
| 72 | /* Take off psocks_avail list */ |
| 73 | list_del(&psock->psock_avail_list); |
| 74 | } else if (wakeup_kcm) { |
| 75 | /* In this case psock is being aborted while outside of |
| 76 | * write_msgs and psock is reserved. Schedule tx_work |
| 77 | * to handle the failure there. Need to commit tx_stopped |
| 78 | * before queuing work. |
| 79 | */ |
| 80 | smp_mb(); |
| 81 | |
| 82 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); |
| 83 | } |
| 84 | |
| 85 | spin_unlock_bh(&mux->lock); |
| 86 | |
| 87 | /* Report error on lower socket */ |
| 88 | report_csk_error(csk, err); |
| 89 | } |
| 90 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 91 | /* RX mux lock held. */ |
| 92 | static void kcm_update_rx_mux_stats(struct kcm_mux *mux, |
| 93 | struct kcm_psock *psock) |
| 94 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 95 | STRP_STATS_ADD(mux->stats.rx_bytes, |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 96 | psock->strp.stats.bytes - |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 97 | psock->saved_rx_bytes); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 98 | mux->stats.rx_msgs += |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 99 | psock->strp.stats.msgs - psock->saved_rx_msgs; |
| 100 | psock->saved_rx_msgs = psock->strp.stats.msgs; |
| 101 | psock->saved_rx_bytes = psock->strp.stats.bytes; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 102 | } |
| 103 | |
| 104 | static void kcm_update_tx_mux_stats(struct kcm_mux *mux, |
| 105 | struct kcm_psock *psock) |
| 106 | { |
| 107 | KCM_STATS_ADD(mux->stats.tx_bytes, |
| 108 | psock->stats.tx_bytes - psock->saved_tx_bytes); |
| 109 | mux->stats.tx_msgs += |
| 110 | psock->stats.tx_msgs - psock->saved_tx_msgs; |
| 111 | psock->saved_tx_msgs = psock->stats.tx_msgs; |
| 112 | psock->saved_tx_bytes = psock->stats.tx_bytes; |
| 113 | } |
| 114 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 115 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); |
| 116 | |
| 117 | /* KCM is ready to receive messages on its queue-- either the KCM is new or |
| 118 | * has become unblocked after being blocked on full socket buffer. Queue any |
| 119 | * pending ready messages on a psock. RX mux lock held. |
| 120 | */ |
| 121 | static void kcm_rcv_ready(struct kcm_sock *kcm) |
| 122 | { |
| 123 | struct kcm_mux *mux = kcm->mux; |
| 124 | struct kcm_psock *psock; |
| 125 | struct sk_buff *skb; |
| 126 | |
| 127 | if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled)) |
| 128 | return; |
| 129 | |
| 130 | while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) { |
| 131 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
| 132 | /* Assuming buffer limit has been reached */ |
| 133 | skb_queue_head(&mux->rx_hold_queue, skb); |
| 134 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); |
| 135 | return; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | while (!list_empty(&mux->psocks_ready)) { |
| 140 | psock = list_first_entry(&mux->psocks_ready, struct kcm_psock, |
| 141 | psock_ready_list); |
| 142 | |
| 143 | if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) { |
| 144 | /* Assuming buffer limit has been reached */ |
| 145 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); |
| 146 | return; |
| 147 | } |
| 148 | |
| 149 | /* Consumed the ready message on the psock. Schedule rx_work to |
| 150 | * get more messages. |
| 151 | */ |
| 152 | list_del(&psock->psock_ready_list); |
| 153 | psock->ready_rx_msg = NULL; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 154 | /* Commit clearing of ready_rx_msg for queuing work */ |
| 155 | smp_mb(); |
| 156 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 157 | strp_unpause(&psock->strp); |
| 158 | strp_check_rcv(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 159 | } |
| 160 | |
| 161 | /* Buffer limit is okay now, add to ready list */ |
| 162 | list_add_tail(&kcm->wait_rx_list, |
| 163 | &kcm->mux->kcm_rx_waiters); |
| 164 | kcm->rx_wait = true; |
| 165 | } |
| 166 | |
| 167 | static void kcm_rfree(struct sk_buff *skb) |
| 168 | { |
| 169 | struct sock *sk = skb->sk; |
| 170 | struct kcm_sock *kcm = kcm_sk(sk); |
| 171 | struct kcm_mux *mux = kcm->mux; |
| 172 | unsigned int len = skb->truesize; |
| 173 | |
| 174 | sk_mem_uncharge(sk, len); |
| 175 | atomic_sub(len, &sk->sk_rmem_alloc); |
| 176 | |
| 177 | /* For reading rx_wait and rx_psock without holding lock */ |
| 178 | smp_mb__after_atomic(); |
| 179 | |
| 180 | if (!kcm->rx_wait && !kcm->rx_psock && |
| 181 | sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) { |
| 182 | spin_lock_bh(&mux->rx_lock); |
| 183 | kcm_rcv_ready(kcm); |
| 184 | spin_unlock_bh(&mux->rx_lock); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) |
| 189 | { |
| 190 | struct sk_buff_head *list = &sk->sk_receive_queue; |
| 191 | |
| 192 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
| 193 | return -ENOMEM; |
| 194 | |
| 195 | if (!sk_rmem_schedule(sk, skb, skb->truesize)) |
| 196 | return -ENOBUFS; |
| 197 | |
| 198 | skb->dev = NULL; |
| 199 | |
| 200 | skb_orphan(skb); |
| 201 | skb->sk = sk; |
| 202 | skb->destructor = kcm_rfree; |
| 203 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); |
| 204 | sk_mem_charge(sk, skb->truesize); |
| 205 | |
| 206 | skb_queue_tail(list, skb); |
| 207 | |
| 208 | if (!sock_flag(sk, SOCK_DEAD)) |
| 209 | sk->sk_data_ready(sk); |
| 210 | |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | /* Requeue received messages for a kcm socket to other kcm sockets. This is |
| 215 | * called with a kcm socket is receive disabled. |
| 216 | * RX mux lock held. |
| 217 | */ |
| 218 | static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head) |
| 219 | { |
| 220 | struct sk_buff *skb; |
| 221 | struct kcm_sock *kcm; |
| 222 | |
| 223 | while ((skb = __skb_dequeue(head))) { |
| 224 | /* Reset destructor to avoid calling kcm_rcv_ready */ |
| 225 | skb->destructor = sock_rfree; |
| 226 | skb_orphan(skb); |
| 227 | try_again: |
| 228 | if (list_empty(&mux->kcm_rx_waiters)) { |
| 229 | skb_queue_tail(&mux->rx_hold_queue, skb); |
| 230 | continue; |
| 231 | } |
| 232 | |
| 233 | kcm = list_first_entry(&mux->kcm_rx_waiters, |
| 234 | struct kcm_sock, wait_rx_list); |
| 235 | |
| 236 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
| 237 | /* Should mean socket buffer full */ |
| 238 | list_del(&kcm->wait_rx_list); |
| 239 | kcm->rx_wait = false; |
| 240 | |
| 241 | /* Commit rx_wait to read in kcm_free */ |
| 242 | smp_wmb(); |
| 243 | |
| 244 | goto try_again; |
| 245 | } |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | /* Lower sock lock held */ |
| 250 | static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock, |
| 251 | struct sk_buff *head) |
| 252 | { |
| 253 | struct kcm_mux *mux = psock->mux; |
| 254 | struct kcm_sock *kcm; |
| 255 | |
| 256 | WARN_ON(psock->ready_rx_msg); |
| 257 | |
| 258 | if (psock->rx_kcm) |
| 259 | return psock->rx_kcm; |
| 260 | |
| 261 | spin_lock_bh(&mux->rx_lock); |
| 262 | |
| 263 | if (psock->rx_kcm) { |
| 264 | spin_unlock_bh(&mux->rx_lock); |
| 265 | return psock->rx_kcm; |
| 266 | } |
| 267 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 268 | kcm_update_rx_mux_stats(mux, psock); |
| 269 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 270 | if (list_empty(&mux->kcm_rx_waiters)) { |
| 271 | psock->ready_rx_msg = head; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 272 | strp_pause(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 273 | list_add_tail(&psock->psock_ready_list, |
| 274 | &mux->psocks_ready); |
| 275 | spin_unlock_bh(&mux->rx_lock); |
| 276 | return NULL; |
| 277 | } |
| 278 | |
| 279 | kcm = list_first_entry(&mux->kcm_rx_waiters, |
| 280 | struct kcm_sock, wait_rx_list); |
| 281 | list_del(&kcm->wait_rx_list); |
| 282 | kcm->rx_wait = false; |
| 283 | |
| 284 | psock->rx_kcm = kcm; |
| 285 | kcm->rx_psock = psock; |
| 286 | |
| 287 | spin_unlock_bh(&mux->rx_lock); |
| 288 | |
| 289 | return kcm; |
| 290 | } |
| 291 | |
| 292 | static void kcm_done(struct kcm_sock *kcm); |
| 293 | |
| 294 | static void kcm_done_work(struct work_struct *w) |
| 295 | { |
| 296 | kcm_done(container_of(w, struct kcm_sock, done_work)); |
| 297 | } |
| 298 | |
| 299 | /* Lower sock held */ |
| 300 | static void unreserve_rx_kcm(struct kcm_psock *psock, |
| 301 | bool rcv_ready) |
| 302 | { |
| 303 | struct kcm_sock *kcm = psock->rx_kcm; |
| 304 | struct kcm_mux *mux = psock->mux; |
| 305 | |
| 306 | if (!kcm) |
| 307 | return; |
| 308 | |
| 309 | spin_lock_bh(&mux->rx_lock); |
| 310 | |
| 311 | psock->rx_kcm = NULL; |
| 312 | kcm->rx_psock = NULL; |
| 313 | |
| 314 | /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with |
| 315 | * kcm_rfree |
| 316 | */ |
| 317 | smp_mb(); |
| 318 | |
| 319 | if (unlikely(kcm->done)) { |
| 320 | spin_unlock_bh(&mux->rx_lock); |
| 321 | |
| 322 | /* Need to run kcm_done in a task since we need to qcquire |
| 323 | * callback locks which may already be held here. |
| 324 | */ |
| 325 | INIT_WORK(&kcm->done_work, kcm_done_work); |
| 326 | schedule_work(&kcm->done_work); |
| 327 | return; |
| 328 | } |
| 329 | |
| 330 | if (unlikely(kcm->rx_disabled)) { |
| 331 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); |
| 332 | } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) { |
| 333 | /* Check for degenerative race with rx_wait that all |
| 334 | * data was dequeued (accounted for in kcm_rfree). |
| 335 | */ |
| 336 | kcm_rcv_ready(kcm); |
| 337 | } |
| 338 | spin_unlock_bh(&mux->rx_lock); |
| 339 | } |
| 340 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 341 | /* Lower sock lock held */ |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 342 | static void psock_data_ready(struct sock *sk) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 343 | { |
| 344 | struct kcm_psock *psock; |
| 345 | |
| 346 | read_lock_bh(&sk->sk_callback_lock); |
| 347 | |
| 348 | psock = (struct kcm_psock *)sk->sk_user_data; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 349 | if (likely(psock)) |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 350 | strp_data_ready(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 351 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 352 | read_unlock_bh(&sk->sk_callback_lock); |
| 353 | } |
| 354 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 355 | /* Called with lower sock held */ |
| 356 | static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 357 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 358 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
| 359 | struct kcm_sock *kcm; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 360 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 361 | try_queue: |
| 362 | kcm = reserve_rx_kcm(psock, skb); |
| 363 | if (!kcm) { |
| 364 | /* Unable to reserve a KCM, message is held in psock and strp |
| 365 | * is paused. |
| 366 | */ |
| 367 | return; |
| 368 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 369 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 370 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
| 371 | /* Should mean socket buffer full */ |
| 372 | unreserve_rx_kcm(psock, false); |
| 373 | goto try_queue; |
| 374 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 375 | } |
| 376 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 377 | 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] | 378 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 379 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
| 380 | struct bpf_prog *prog = psock->bpf_prog; |
Eric Dumazet | 0355d6c | 2019-09-24 12:29:34 -0700 | [diff] [blame] | 381 | int res; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 382 | |
Eric Dumazet | 0355d6c | 2019-09-24 12:29:34 -0700 | [diff] [blame] | 383 | preempt_disable(); |
| 384 | res = BPF_PROG_RUN(prog, skb); |
| 385 | preempt_enable(); |
| 386 | return res; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 387 | } |
| 388 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 389 | static int kcm_read_sock_done(struct strparser *strp, int err) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 390 | { |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 391 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
| 392 | |
| 393 | unreserve_rx_kcm(psock, true); |
| 394 | |
| 395 | return err; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 396 | } |
| 397 | |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 398 | static void psock_state_change(struct sock *sk) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 399 | { |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame] | 400 | /* TCP only does a EPOLLIN for a half close. Do a EPOLLHUP here |
| 401 | * since application will normally not poll with EPOLLIN |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 402 | * on the TCP sockets. |
| 403 | */ |
| 404 | |
| 405 | report_csk_error(sk, EPIPE); |
| 406 | } |
| 407 | |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 408 | static void psock_write_space(struct sock *sk) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 409 | { |
| 410 | struct kcm_psock *psock; |
| 411 | struct kcm_mux *mux; |
| 412 | struct kcm_sock *kcm; |
| 413 | |
| 414 | read_lock_bh(&sk->sk_callback_lock); |
| 415 | |
| 416 | psock = (struct kcm_psock *)sk->sk_user_data; |
| 417 | if (unlikely(!psock)) |
| 418 | goto out; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 419 | mux = psock->mux; |
| 420 | |
| 421 | spin_lock_bh(&mux->lock); |
| 422 | |
| 423 | /* Check if the socket is reserved so someone is waiting for sending. */ |
| 424 | kcm = psock->tx_kcm; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 425 | if (kcm && !unlikely(kcm->tx_stopped)) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 426 | queue_work(kcm_wq, &kcm->tx_work); |
| 427 | |
| 428 | spin_unlock_bh(&mux->lock); |
| 429 | out: |
| 430 | read_unlock_bh(&sk->sk_callback_lock); |
| 431 | } |
| 432 | |
| 433 | static void unreserve_psock(struct kcm_sock *kcm); |
| 434 | |
| 435 | /* kcm sock is locked. */ |
| 436 | static struct kcm_psock *reserve_psock(struct kcm_sock *kcm) |
| 437 | { |
| 438 | struct kcm_mux *mux = kcm->mux; |
| 439 | struct kcm_psock *psock; |
| 440 | |
| 441 | psock = kcm->tx_psock; |
| 442 | |
| 443 | smp_rmb(); /* Must read tx_psock before tx_wait */ |
| 444 | |
| 445 | if (psock) { |
| 446 | WARN_ON(kcm->tx_wait); |
| 447 | if (unlikely(psock->tx_stopped)) |
| 448 | unreserve_psock(kcm); |
| 449 | else |
| 450 | return kcm->tx_psock; |
| 451 | } |
| 452 | |
| 453 | spin_lock_bh(&mux->lock); |
| 454 | |
| 455 | /* Check again under lock to see if psock was reserved for this |
| 456 | * psock via psock_unreserve. |
| 457 | */ |
| 458 | psock = kcm->tx_psock; |
| 459 | if (unlikely(psock)) { |
| 460 | WARN_ON(kcm->tx_wait); |
| 461 | spin_unlock_bh(&mux->lock); |
| 462 | return kcm->tx_psock; |
| 463 | } |
| 464 | |
| 465 | if (!list_empty(&mux->psocks_avail)) { |
| 466 | psock = list_first_entry(&mux->psocks_avail, |
| 467 | struct kcm_psock, |
| 468 | psock_avail_list); |
| 469 | list_del(&psock->psock_avail_list); |
| 470 | if (kcm->tx_wait) { |
| 471 | list_del(&kcm->wait_psock_list); |
| 472 | kcm->tx_wait = false; |
| 473 | } |
| 474 | kcm->tx_psock = psock; |
| 475 | psock->tx_kcm = kcm; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 476 | KCM_STATS_INCR(psock->stats.reserved); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 477 | } else if (!kcm->tx_wait) { |
| 478 | list_add_tail(&kcm->wait_psock_list, |
| 479 | &mux->kcm_tx_waiters); |
| 480 | kcm->tx_wait = true; |
| 481 | } |
| 482 | |
| 483 | spin_unlock_bh(&mux->lock); |
| 484 | |
| 485 | return psock; |
| 486 | } |
| 487 | |
| 488 | /* mux lock held */ |
| 489 | static void psock_now_avail(struct kcm_psock *psock) |
| 490 | { |
| 491 | struct kcm_mux *mux = psock->mux; |
| 492 | struct kcm_sock *kcm; |
| 493 | |
| 494 | if (list_empty(&mux->kcm_tx_waiters)) { |
| 495 | list_add_tail(&psock->psock_avail_list, |
| 496 | &mux->psocks_avail); |
| 497 | } else { |
| 498 | kcm = list_first_entry(&mux->kcm_tx_waiters, |
| 499 | struct kcm_sock, |
| 500 | wait_psock_list); |
| 501 | list_del(&kcm->wait_psock_list); |
| 502 | kcm->tx_wait = false; |
| 503 | psock->tx_kcm = kcm; |
| 504 | |
| 505 | /* Commit before changing tx_psock since that is read in |
| 506 | * reserve_psock before queuing work. |
| 507 | */ |
| 508 | smp_mb(); |
| 509 | |
| 510 | kcm->tx_psock = psock; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 511 | KCM_STATS_INCR(psock->stats.reserved); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 512 | queue_work(kcm_wq, &kcm->tx_work); |
| 513 | } |
| 514 | } |
| 515 | |
| 516 | /* kcm sock is locked. */ |
| 517 | static void unreserve_psock(struct kcm_sock *kcm) |
| 518 | { |
| 519 | struct kcm_psock *psock; |
| 520 | struct kcm_mux *mux = kcm->mux; |
| 521 | |
| 522 | spin_lock_bh(&mux->lock); |
| 523 | |
| 524 | psock = kcm->tx_psock; |
| 525 | |
| 526 | if (WARN_ON(!psock)) { |
| 527 | spin_unlock_bh(&mux->lock); |
| 528 | return; |
| 529 | } |
| 530 | |
| 531 | smp_rmb(); /* Read tx_psock before tx_wait */ |
| 532 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 533 | kcm_update_tx_mux_stats(mux, psock); |
| 534 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 535 | WARN_ON(kcm->tx_wait); |
| 536 | |
| 537 | kcm->tx_psock = NULL; |
| 538 | psock->tx_kcm = NULL; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 539 | KCM_STATS_INCR(psock->stats.unreserved); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 540 | |
| 541 | if (unlikely(psock->tx_stopped)) { |
| 542 | if (psock->done) { |
| 543 | /* Deferred free */ |
| 544 | list_del(&psock->psock_list); |
| 545 | mux->psocks_cnt--; |
| 546 | sock_put(psock->sk); |
| 547 | fput(psock->sk->sk_socket->file); |
| 548 | kmem_cache_free(kcm_psockp, psock); |
| 549 | } |
| 550 | |
| 551 | /* Don't put back on available list */ |
| 552 | |
| 553 | spin_unlock_bh(&mux->lock); |
| 554 | |
| 555 | return; |
| 556 | } |
| 557 | |
| 558 | psock_now_avail(psock); |
| 559 | |
| 560 | spin_unlock_bh(&mux->lock); |
| 561 | } |
| 562 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 563 | static void kcm_report_tx_retry(struct kcm_sock *kcm) |
| 564 | { |
| 565 | struct kcm_mux *mux = kcm->mux; |
| 566 | |
| 567 | spin_lock_bh(&mux->lock); |
| 568 | KCM_STATS_INCR(mux->stats.tx_retries); |
| 569 | spin_unlock_bh(&mux->lock); |
| 570 | } |
| 571 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 572 | /* Write any messages ready on the kcm socket. Called with kcm sock lock |
| 573 | * held. Return bytes actually sent or error. |
| 574 | */ |
| 575 | static int kcm_write_msgs(struct kcm_sock *kcm) |
| 576 | { |
| 577 | struct sock *sk = &kcm->sk; |
| 578 | struct kcm_psock *psock; |
| 579 | struct sk_buff *skb, *head; |
| 580 | struct kcm_tx_msg *txm; |
| 581 | unsigned short fragidx, frag_offset; |
| 582 | unsigned int sent, total_sent = 0; |
| 583 | int ret = 0; |
| 584 | |
| 585 | kcm->tx_wait_more = false; |
| 586 | psock = kcm->tx_psock; |
| 587 | if (unlikely(psock && psock->tx_stopped)) { |
| 588 | /* A reserved psock was aborted asynchronously. Unreserve |
| 589 | * it and we'll retry the message. |
| 590 | */ |
| 591 | unreserve_psock(kcm); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 592 | kcm_report_tx_retry(kcm); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 593 | if (skb_queue_empty(&sk->sk_write_queue)) |
| 594 | return 0; |
| 595 | |
| 596 | kcm_tx_msg(skb_peek(&sk->sk_write_queue))->sent = 0; |
| 597 | |
| 598 | } else if (skb_queue_empty(&sk->sk_write_queue)) { |
| 599 | return 0; |
| 600 | } |
| 601 | |
| 602 | head = skb_peek(&sk->sk_write_queue); |
| 603 | txm = kcm_tx_msg(head); |
| 604 | |
| 605 | if (txm->sent) { |
| 606 | /* Send of first skbuff in queue already in progress */ |
| 607 | if (WARN_ON(!psock)) { |
| 608 | ret = -EINVAL; |
| 609 | goto out; |
| 610 | } |
| 611 | sent = txm->sent; |
| 612 | frag_offset = txm->frag_offset; |
| 613 | fragidx = txm->fragidx; |
| 614 | skb = txm->frag_skb; |
| 615 | |
| 616 | goto do_frag; |
| 617 | } |
| 618 | |
| 619 | try_again: |
| 620 | psock = reserve_psock(kcm); |
| 621 | if (!psock) |
| 622 | goto out; |
| 623 | |
| 624 | do { |
| 625 | skb = head; |
| 626 | txm = kcm_tx_msg(head); |
| 627 | sent = 0; |
| 628 | |
| 629 | do_frag_list: |
| 630 | if (WARN_ON(!skb_shinfo(skb)->nr_frags)) { |
| 631 | ret = -EINVAL; |
| 632 | goto out; |
| 633 | } |
| 634 | |
| 635 | for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; |
| 636 | fragidx++) { |
| 637 | skb_frag_t *frag; |
| 638 | |
| 639 | frag_offset = 0; |
| 640 | do_frag: |
| 641 | frag = &skb_shinfo(skb)->frags[fragidx]; |
Matthew Wilcox (Oracle) | d8e18a5 | 2019-07-22 20:08:26 -0700 | [diff] [blame] | 642 | if (WARN_ON(!skb_frag_size(frag))) { |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 643 | ret = -EINVAL; |
| 644 | goto out; |
| 645 | } |
| 646 | |
| 647 | ret = kernel_sendpage(psock->sk->sk_socket, |
Matthew Wilcox (Oracle) | d8e18a5 | 2019-07-22 20:08:26 -0700 | [diff] [blame] | 648 | skb_frag_page(frag), |
Jonathan Lemon | b54c9d5 | 2019-07-30 07:40:33 -0700 | [diff] [blame] | 649 | skb_frag_off(frag) + frag_offset, |
Matthew Wilcox (Oracle) | d8e18a5 | 2019-07-22 20:08:26 -0700 | [diff] [blame] | 650 | skb_frag_size(frag) - frag_offset, |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 651 | MSG_DONTWAIT); |
| 652 | if (ret <= 0) { |
| 653 | if (ret == -EAGAIN) { |
| 654 | /* Save state to try again when there's |
| 655 | * write space on the socket |
| 656 | */ |
| 657 | txm->sent = sent; |
| 658 | txm->frag_offset = frag_offset; |
| 659 | txm->fragidx = fragidx; |
| 660 | txm->frag_skb = skb; |
| 661 | |
| 662 | ret = 0; |
| 663 | goto out; |
| 664 | } |
| 665 | |
| 666 | /* Hard failure in sending message, abort this |
| 667 | * psock since it has lost framing |
| 668 | * synchonization and retry sending the |
| 669 | * message from the beginning. |
| 670 | */ |
| 671 | kcm_abort_tx_psock(psock, ret ? -ret : EPIPE, |
| 672 | true); |
| 673 | unreserve_psock(kcm); |
| 674 | |
| 675 | txm->sent = 0; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 676 | kcm_report_tx_retry(kcm); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 677 | ret = 0; |
| 678 | |
| 679 | goto try_again; |
| 680 | } |
| 681 | |
| 682 | sent += ret; |
| 683 | frag_offset += ret; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 684 | KCM_STATS_ADD(psock->stats.tx_bytes, ret); |
Matthew Wilcox (Oracle) | d8e18a5 | 2019-07-22 20:08:26 -0700 | [diff] [blame] | 685 | if (frag_offset < skb_frag_size(frag)) { |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 686 | /* Not finished with this frag */ |
| 687 | goto do_frag; |
| 688 | } |
| 689 | } |
| 690 | |
| 691 | if (skb == head) { |
| 692 | if (skb_has_frag_list(skb)) { |
| 693 | skb = skb_shinfo(skb)->frag_list; |
| 694 | goto do_frag_list; |
| 695 | } |
| 696 | } else if (skb->next) { |
| 697 | skb = skb->next; |
| 698 | goto do_frag_list; |
| 699 | } |
| 700 | |
| 701 | /* Successfully sent the whole packet, account for it. */ |
| 702 | skb_dequeue(&sk->sk_write_queue); |
| 703 | kfree_skb(head); |
| 704 | sk->sk_wmem_queued -= sent; |
| 705 | total_sent += sent; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 706 | KCM_STATS_INCR(psock->stats.tx_msgs); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 707 | } while ((head = skb_peek(&sk->sk_write_queue))); |
| 708 | out: |
| 709 | if (!head) { |
| 710 | /* Done with all queued messages. */ |
| 711 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); |
| 712 | unreserve_psock(kcm); |
| 713 | } |
| 714 | |
| 715 | /* Check if write space is available */ |
| 716 | sk->sk_write_space(sk); |
| 717 | |
| 718 | return total_sent ? : ret; |
| 719 | } |
| 720 | |
| 721 | static void kcm_tx_work(struct work_struct *w) |
| 722 | { |
| 723 | struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work); |
| 724 | struct sock *sk = &kcm->sk; |
| 725 | int err; |
| 726 | |
| 727 | lock_sock(sk); |
| 728 | |
| 729 | /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx |
| 730 | * aborts |
| 731 | */ |
| 732 | err = kcm_write_msgs(kcm); |
| 733 | if (err < 0) { |
| 734 | /* Hard failure in write, report error on KCM socket */ |
| 735 | pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err); |
| 736 | report_csk_error(&kcm->sk, -err); |
| 737 | goto out; |
| 738 | } |
| 739 | |
| 740 | /* Primarily for SOCK_SEQPACKET sockets */ |
| 741 | if (likely(sk->sk_socket) && |
| 742 | test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { |
| 743 | clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 744 | sk->sk_write_space(sk); |
| 745 | } |
| 746 | |
| 747 | out: |
| 748 | release_sock(sk); |
| 749 | } |
| 750 | |
| 751 | static void kcm_push(struct kcm_sock *kcm) |
| 752 | { |
| 753 | if (kcm->tx_wait_more) |
| 754 | kcm_write_msgs(kcm); |
| 755 | } |
| 756 | |
Tom Herbert | f29698fc | 2016-03-07 14:11:09 -0800 | [diff] [blame] | 757 | static ssize_t kcm_sendpage(struct socket *sock, struct page *page, |
| 758 | int offset, size_t size, int flags) |
| 759 | |
| 760 | { |
| 761 | struct sock *sk = sock->sk; |
| 762 | struct kcm_sock *kcm = kcm_sk(sk); |
| 763 | struct sk_buff *skb = NULL, *head = NULL; |
| 764 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); |
| 765 | bool eor; |
| 766 | int err = 0; |
| 767 | int i; |
| 768 | |
| 769 | if (flags & MSG_SENDPAGE_NOTLAST) |
| 770 | flags |= MSG_MORE; |
| 771 | |
| 772 | /* No MSG_EOR from splice, only look at MSG_MORE */ |
| 773 | eor = !(flags & MSG_MORE); |
| 774 | |
| 775 | lock_sock(sk); |
| 776 | |
| 777 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
| 778 | |
| 779 | err = -EPIPE; |
| 780 | if (sk->sk_err) |
| 781 | goto out_error; |
| 782 | |
| 783 | if (kcm->seq_skb) { |
| 784 | /* Previously opened message */ |
| 785 | head = kcm->seq_skb; |
| 786 | skb = kcm_tx_msg(head)->last_skb; |
| 787 | i = skb_shinfo(skb)->nr_frags; |
| 788 | |
| 789 | if (skb_can_coalesce(skb, i, page, offset)) { |
| 790 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); |
| 791 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
| 792 | goto coalesced; |
| 793 | } |
| 794 | |
| 795 | if (i >= MAX_SKB_FRAGS) { |
| 796 | struct sk_buff *tskb; |
| 797 | |
| 798 | tskb = alloc_skb(0, sk->sk_allocation); |
| 799 | while (!tskb) { |
| 800 | kcm_push(kcm); |
| 801 | err = sk_stream_wait_memory(sk, &timeo); |
| 802 | if (err) |
| 803 | goto out_error; |
| 804 | } |
| 805 | |
| 806 | if (head == skb) |
| 807 | skb_shinfo(head)->frag_list = tskb; |
| 808 | else |
| 809 | skb->next = tskb; |
| 810 | |
| 811 | skb = tskb; |
| 812 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 813 | i = 0; |
| 814 | } |
| 815 | } else { |
| 816 | /* Call the sk_stream functions to manage the sndbuf mem. */ |
| 817 | if (!sk_stream_memory_free(sk)) { |
| 818 | kcm_push(kcm); |
| 819 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 820 | err = sk_stream_wait_memory(sk, &timeo); |
| 821 | if (err) |
| 822 | goto out_error; |
| 823 | } |
| 824 | |
| 825 | head = alloc_skb(0, sk->sk_allocation); |
| 826 | while (!head) { |
| 827 | kcm_push(kcm); |
| 828 | err = sk_stream_wait_memory(sk, &timeo); |
| 829 | if (err) |
| 830 | goto out_error; |
| 831 | } |
| 832 | |
| 833 | skb = head; |
| 834 | i = 0; |
| 835 | } |
| 836 | |
| 837 | get_page(page); |
| 838 | skb_fill_page_desc(skb, i, page, offset, size); |
| 839 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
| 840 | |
| 841 | coalesced: |
| 842 | skb->len += size; |
| 843 | skb->data_len += size; |
| 844 | skb->truesize += size; |
| 845 | sk->sk_wmem_queued += size; |
| 846 | sk_mem_charge(sk, size); |
| 847 | |
| 848 | if (head != skb) { |
| 849 | head->len += size; |
| 850 | head->data_len += size; |
| 851 | head->truesize += size; |
| 852 | } |
| 853 | |
| 854 | if (eor) { |
| 855 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); |
| 856 | |
| 857 | /* Message complete, queue it on send buffer */ |
| 858 | __skb_queue_tail(&sk->sk_write_queue, head); |
| 859 | kcm->seq_skb = NULL; |
| 860 | KCM_STATS_INCR(kcm->stats.tx_msgs); |
| 861 | |
| 862 | if (flags & MSG_BATCH) { |
| 863 | kcm->tx_wait_more = true; |
| 864 | } else if (kcm->tx_wait_more || not_busy) { |
| 865 | err = kcm_write_msgs(kcm); |
| 866 | if (err < 0) { |
| 867 | /* We got a hard error in write_msgs but have |
| 868 | * already queued this message. Report an error |
| 869 | * in the socket, but don't affect return value |
| 870 | * from sendmsg |
| 871 | */ |
| 872 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); |
| 873 | report_csk_error(&kcm->sk, -err); |
| 874 | } |
| 875 | } |
| 876 | } else { |
| 877 | /* Message not complete, save state */ |
| 878 | kcm->seq_skb = head; |
| 879 | kcm_tx_msg(head)->last_skb = skb; |
| 880 | } |
| 881 | |
| 882 | KCM_STATS_ADD(kcm->stats.tx_bytes, size); |
| 883 | |
| 884 | release_sock(sk); |
| 885 | return size; |
| 886 | |
| 887 | out_error: |
| 888 | kcm_push(kcm); |
| 889 | |
| 890 | err = sk_stream_error(sk, flags, err); |
| 891 | |
| 892 | /* make sure we wake any epoll edge trigger waiter */ |
| 893 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) |
| 894 | sk->sk_write_space(sk); |
| 895 | |
| 896 | release_sock(sk); |
| 897 | return err; |
| 898 | } |
| 899 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 900 | static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
| 901 | { |
| 902 | struct sock *sk = sock->sk; |
| 903 | struct kcm_sock *kcm = kcm_sk(sk); |
| 904 | struct sk_buff *skb = NULL, *head = NULL; |
| 905 | size_t copy, copied = 0; |
| 906 | long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
| 907 | int eor = (sock->type == SOCK_DGRAM) ? |
| 908 | !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR); |
| 909 | int err = -EPIPE; |
| 910 | |
| 911 | lock_sock(sk); |
| 912 | |
| 913 | /* Per tcp_sendmsg this should be in poll */ |
| 914 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
| 915 | |
| 916 | if (sk->sk_err) |
| 917 | goto out_error; |
| 918 | |
| 919 | if (kcm->seq_skb) { |
| 920 | /* Previously opened message */ |
| 921 | head = kcm->seq_skb; |
| 922 | skb = kcm_tx_msg(head)->last_skb; |
| 923 | goto start; |
| 924 | } |
| 925 | |
| 926 | /* Call the sk_stream functions to manage the sndbuf mem. */ |
| 927 | if (!sk_stream_memory_free(sk)) { |
| 928 | kcm_push(kcm); |
| 929 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 930 | err = sk_stream_wait_memory(sk, &timeo); |
| 931 | if (err) |
| 932 | goto out_error; |
| 933 | } |
| 934 | |
WANG Cong | 98e3862c | 2017-02-07 12:59:47 -0800 | [diff] [blame] | 935 | if (msg_data_left(msg)) { |
| 936 | /* New message, alloc head skb */ |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 937 | head = alloc_skb(0, sk->sk_allocation); |
WANG Cong | 98e3862c | 2017-02-07 12:59:47 -0800 | [diff] [blame] | 938 | while (!head) { |
| 939 | kcm_push(kcm); |
| 940 | err = sk_stream_wait_memory(sk, &timeo); |
| 941 | if (err) |
| 942 | goto out_error; |
| 943 | |
| 944 | head = alloc_skb(0, sk->sk_allocation); |
| 945 | } |
| 946 | |
| 947 | skb = head; |
| 948 | |
| 949 | /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling |
| 950 | * csum_and_copy_from_iter from skb_do_copy_data_nocache. |
| 951 | */ |
| 952 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 953 | } |
| 954 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 955 | start: |
| 956 | while (msg_data_left(msg)) { |
| 957 | bool merge = true; |
| 958 | int i = skb_shinfo(skb)->nr_frags; |
| 959 | struct page_frag *pfrag = sk_page_frag(sk); |
| 960 | |
| 961 | if (!sk_page_frag_refill(sk, pfrag)) |
| 962 | goto wait_for_memory; |
| 963 | |
| 964 | if (!skb_can_coalesce(skb, i, pfrag->page, |
| 965 | pfrag->offset)) { |
| 966 | if (i == MAX_SKB_FRAGS) { |
| 967 | struct sk_buff *tskb; |
| 968 | |
| 969 | tskb = alloc_skb(0, sk->sk_allocation); |
| 970 | if (!tskb) |
| 971 | goto wait_for_memory; |
| 972 | |
| 973 | if (head == skb) |
| 974 | skb_shinfo(head)->frag_list = tskb; |
| 975 | else |
| 976 | skb->next = tskb; |
| 977 | |
| 978 | skb = tskb; |
| 979 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 980 | continue; |
| 981 | } |
| 982 | merge = false; |
| 983 | } |
| 984 | |
| 985 | copy = min_t(int, msg_data_left(msg), |
| 986 | pfrag->size - pfrag->offset); |
| 987 | |
| 988 | if (!sk_wmem_schedule(sk, copy)) |
| 989 | goto wait_for_memory; |
| 990 | |
| 991 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, |
| 992 | pfrag->page, |
| 993 | pfrag->offset, |
| 994 | copy); |
| 995 | if (err) |
| 996 | goto out_error; |
| 997 | |
| 998 | /* Update the skb. */ |
| 999 | if (merge) { |
| 1000 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
| 1001 | } else { |
| 1002 | skb_fill_page_desc(skb, i, pfrag->page, |
| 1003 | pfrag->offset, copy); |
| 1004 | get_page(pfrag->page); |
| 1005 | } |
| 1006 | |
| 1007 | pfrag->offset += copy; |
| 1008 | copied += copy; |
| 1009 | if (head != skb) { |
| 1010 | head->len += copy; |
| 1011 | head->data_len += copy; |
| 1012 | } |
| 1013 | |
| 1014 | continue; |
| 1015 | |
| 1016 | wait_for_memory: |
| 1017 | kcm_push(kcm); |
| 1018 | err = sk_stream_wait_memory(sk, &timeo); |
| 1019 | if (err) |
| 1020 | goto out_error; |
| 1021 | } |
| 1022 | |
| 1023 | if (eor) { |
| 1024 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); |
| 1025 | |
WANG Cong | 98e3862c | 2017-02-07 12:59:47 -0800 | [diff] [blame] | 1026 | if (head) { |
| 1027 | /* Message complete, queue it on send buffer */ |
| 1028 | __skb_queue_tail(&sk->sk_write_queue, head); |
| 1029 | kcm->seq_skb = NULL; |
| 1030 | KCM_STATS_INCR(kcm->stats.tx_msgs); |
| 1031 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1032 | |
| 1033 | if (msg->msg_flags & MSG_BATCH) { |
| 1034 | kcm->tx_wait_more = true; |
| 1035 | } else if (kcm->tx_wait_more || not_busy) { |
| 1036 | err = kcm_write_msgs(kcm); |
| 1037 | if (err < 0) { |
| 1038 | /* We got a hard error in write_msgs but have |
| 1039 | * already queued this message. Report an error |
| 1040 | * in the socket, but don't affect return value |
| 1041 | * from sendmsg |
| 1042 | */ |
| 1043 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); |
| 1044 | report_csk_error(&kcm->sk, -err); |
| 1045 | } |
| 1046 | } |
| 1047 | } else { |
| 1048 | /* Message not complete, save state */ |
| 1049 | partial_message: |
WANG Cong | cd27b96 | 2017-02-13 11:13:16 -0800 | [diff] [blame] | 1050 | if (head) { |
| 1051 | kcm->seq_skb = head; |
| 1052 | kcm_tx_msg(head)->last_skb = skb; |
| 1053 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1054 | } |
| 1055 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1056 | KCM_STATS_ADD(kcm->stats.tx_bytes, copied); |
| 1057 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1058 | release_sock(sk); |
| 1059 | return copied; |
| 1060 | |
| 1061 | out_error: |
| 1062 | kcm_push(kcm); |
| 1063 | |
| 1064 | if (copied && sock->type == SOCK_SEQPACKET) { |
| 1065 | /* Wrote some bytes before encountering an |
| 1066 | * error, return partial success. |
| 1067 | */ |
| 1068 | goto partial_message; |
| 1069 | } |
| 1070 | |
| 1071 | if (head != kcm->seq_skb) |
| 1072 | kfree_skb(head); |
| 1073 | |
| 1074 | err = sk_stream_error(sk, msg->msg_flags, err); |
| 1075 | |
| 1076 | /* make sure we wake any epoll edge trigger waiter */ |
| 1077 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) |
| 1078 | sk->sk_write_space(sk); |
| 1079 | |
| 1080 | release_sock(sk); |
| 1081 | return err; |
| 1082 | } |
| 1083 | |
| 1084 | static struct sk_buff *kcm_wait_data(struct sock *sk, int flags, |
| 1085 | long timeo, int *err) |
| 1086 | { |
| 1087 | struct sk_buff *skb; |
| 1088 | |
| 1089 | while (!(skb = skb_peek(&sk->sk_receive_queue))) { |
| 1090 | if (sk->sk_err) { |
| 1091 | *err = sock_error(sk); |
| 1092 | return NULL; |
| 1093 | } |
| 1094 | |
| 1095 | if (sock_flag(sk, SOCK_DONE)) |
| 1096 | return NULL; |
| 1097 | |
| 1098 | if ((flags & MSG_DONTWAIT) || !timeo) { |
| 1099 | *err = -EAGAIN; |
| 1100 | return NULL; |
| 1101 | } |
| 1102 | |
| 1103 | sk_wait_data(sk, &timeo, NULL); |
| 1104 | |
| 1105 | /* Handle signals */ |
| 1106 | if (signal_pending(current)) { |
| 1107 | *err = sock_intr_errno(timeo); |
| 1108 | return NULL; |
| 1109 | } |
| 1110 | } |
| 1111 | |
| 1112 | return skb; |
| 1113 | } |
| 1114 | |
| 1115 | static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, |
| 1116 | size_t len, int flags) |
| 1117 | { |
| 1118 | struct sock *sk = sock->sk; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1119 | struct kcm_sock *kcm = kcm_sk(sk); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1120 | int err = 0; |
| 1121 | long timeo; |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1122 | struct strp_msg *stm; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1123 | int copied = 0; |
| 1124 | struct sk_buff *skb; |
| 1125 | |
| 1126 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
| 1127 | |
| 1128 | lock_sock(sk); |
| 1129 | |
| 1130 | skb = kcm_wait_data(sk, flags, timeo, &err); |
| 1131 | if (!skb) |
| 1132 | goto out; |
| 1133 | |
| 1134 | /* Okay, have a message on the receive queue */ |
| 1135 | |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1136 | stm = strp_msg(skb); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1137 | |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1138 | if (len > stm->full_len) |
| 1139 | len = stm->full_len; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1140 | |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1141 | err = skb_copy_datagram_msg(skb, stm->offset, msg, len); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1142 | if (err < 0) |
| 1143 | goto out; |
| 1144 | |
| 1145 | copied = len; |
| 1146 | if (likely(!(flags & MSG_PEEK))) { |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1147 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1148 | if (copied < stm->full_len) { |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1149 | if (sock->type == SOCK_DGRAM) { |
| 1150 | /* Truncated message */ |
| 1151 | msg->msg_flags |= MSG_TRUNC; |
| 1152 | goto msg_finished; |
| 1153 | } |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1154 | stm->offset += copied; |
| 1155 | stm->full_len -= copied; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1156 | } else { |
| 1157 | msg_finished: |
| 1158 | /* Finished with message */ |
| 1159 | msg->msg_flags |= MSG_EOR; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1160 | KCM_STATS_INCR(kcm->stats.rx_msgs); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1161 | skb_unlink(skb, &sk->sk_receive_queue); |
| 1162 | kfree_skb(skb); |
| 1163 | } |
| 1164 | } |
| 1165 | |
| 1166 | out: |
| 1167 | release_sock(sk); |
| 1168 | |
| 1169 | return copied ? : err; |
| 1170 | } |
| 1171 | |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1172 | static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, |
| 1173 | struct pipe_inode_info *pipe, size_t len, |
| 1174 | unsigned int flags) |
| 1175 | { |
| 1176 | struct sock *sk = sock->sk; |
| 1177 | struct kcm_sock *kcm = kcm_sk(sk); |
| 1178 | long timeo; |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1179 | struct strp_msg *stm; |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1180 | int err = 0; |
WANG Cong | f1971a2 | 2016-05-17 14:05:49 -0700 | [diff] [blame] | 1181 | ssize_t copied; |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1182 | struct sk_buff *skb; |
| 1183 | |
| 1184 | /* Only support splice for SOCKSEQPACKET */ |
| 1185 | |
| 1186 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
| 1187 | |
| 1188 | lock_sock(sk); |
| 1189 | |
| 1190 | skb = kcm_wait_data(sk, flags, timeo, &err); |
| 1191 | if (!skb) |
| 1192 | goto err_out; |
| 1193 | |
| 1194 | /* Okay, have a message on the receive queue */ |
| 1195 | |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1196 | stm = strp_msg(skb); |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1197 | |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1198 | if (len > stm->full_len) |
| 1199 | len = stm->full_len; |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1200 | |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1201 | copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags); |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1202 | if (copied < 0) { |
| 1203 | err = copied; |
| 1204 | goto err_out; |
| 1205 | } |
| 1206 | |
| 1207 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
| 1208 | |
Tom Herbert | bbb0302 | 2017-07-28 16:22:43 -0700 | [diff] [blame] | 1209 | stm->offset += copied; |
| 1210 | stm->full_len -= copied; |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1211 | |
| 1212 | /* We have no way to return MSG_EOR. If all the bytes have been |
| 1213 | * read we still leave the message in the receive socket buffer. |
| 1214 | * A subsequent recvmsg needs to be done to return MSG_EOR and |
| 1215 | * finish reading the message. |
| 1216 | */ |
| 1217 | |
| 1218 | release_sock(sk); |
| 1219 | |
| 1220 | return copied; |
| 1221 | |
| 1222 | err_out: |
| 1223 | release_sock(sk); |
| 1224 | |
| 1225 | return err; |
| 1226 | } |
| 1227 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1228 | /* kcm sock lock held */ |
| 1229 | static void kcm_recv_disable(struct kcm_sock *kcm) |
| 1230 | { |
| 1231 | struct kcm_mux *mux = kcm->mux; |
| 1232 | |
| 1233 | if (kcm->rx_disabled) |
| 1234 | return; |
| 1235 | |
| 1236 | spin_lock_bh(&mux->rx_lock); |
| 1237 | |
| 1238 | kcm->rx_disabled = 1; |
| 1239 | |
| 1240 | /* If a psock is reserved we'll do cleanup in unreserve */ |
| 1241 | if (!kcm->rx_psock) { |
| 1242 | if (kcm->rx_wait) { |
| 1243 | list_del(&kcm->wait_rx_list); |
| 1244 | kcm->rx_wait = false; |
| 1245 | } |
| 1246 | |
| 1247 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); |
| 1248 | } |
| 1249 | |
| 1250 | spin_unlock_bh(&mux->rx_lock); |
| 1251 | } |
| 1252 | |
| 1253 | /* kcm sock lock held */ |
| 1254 | static void kcm_recv_enable(struct kcm_sock *kcm) |
| 1255 | { |
| 1256 | struct kcm_mux *mux = kcm->mux; |
| 1257 | |
| 1258 | if (!kcm->rx_disabled) |
| 1259 | return; |
| 1260 | |
| 1261 | spin_lock_bh(&mux->rx_lock); |
| 1262 | |
| 1263 | kcm->rx_disabled = 0; |
| 1264 | kcm_rcv_ready(kcm); |
| 1265 | |
| 1266 | spin_unlock_bh(&mux->rx_lock); |
| 1267 | } |
| 1268 | |
| 1269 | static int kcm_setsockopt(struct socket *sock, int level, int optname, |
| 1270 | char __user *optval, unsigned int optlen) |
| 1271 | { |
| 1272 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1273 | int val, valbool; |
| 1274 | int err = 0; |
| 1275 | |
| 1276 | if (level != SOL_KCM) |
| 1277 | return -ENOPROTOOPT; |
| 1278 | |
| 1279 | if (optlen < sizeof(int)) |
| 1280 | return -EINVAL; |
| 1281 | |
| 1282 | if (get_user(val, (int __user *)optval)) |
| 1283 | return -EINVAL; |
| 1284 | |
| 1285 | valbool = val ? 1 : 0; |
| 1286 | |
| 1287 | switch (optname) { |
| 1288 | case KCM_RECV_DISABLE: |
| 1289 | lock_sock(&kcm->sk); |
| 1290 | if (valbool) |
| 1291 | kcm_recv_disable(kcm); |
| 1292 | else |
| 1293 | kcm_recv_enable(kcm); |
| 1294 | release_sock(&kcm->sk); |
| 1295 | break; |
| 1296 | default: |
| 1297 | err = -ENOPROTOOPT; |
| 1298 | } |
| 1299 | |
| 1300 | return err; |
| 1301 | } |
| 1302 | |
| 1303 | static int kcm_getsockopt(struct socket *sock, int level, int optname, |
| 1304 | char __user *optval, int __user *optlen) |
| 1305 | { |
| 1306 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1307 | int val, len; |
| 1308 | |
| 1309 | if (level != SOL_KCM) |
| 1310 | return -ENOPROTOOPT; |
| 1311 | |
| 1312 | if (get_user(len, optlen)) |
| 1313 | return -EFAULT; |
| 1314 | |
| 1315 | len = min_t(unsigned int, len, sizeof(int)); |
| 1316 | if (len < 0) |
| 1317 | return -EINVAL; |
| 1318 | |
| 1319 | switch (optname) { |
| 1320 | case KCM_RECV_DISABLE: |
| 1321 | val = kcm->rx_disabled; |
| 1322 | break; |
| 1323 | default: |
| 1324 | return -ENOPROTOOPT; |
| 1325 | } |
| 1326 | |
| 1327 | if (put_user(len, optlen)) |
| 1328 | return -EFAULT; |
| 1329 | if (copy_to_user(optval, &val, len)) |
| 1330 | return -EFAULT; |
| 1331 | return 0; |
| 1332 | } |
| 1333 | |
| 1334 | static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux) |
| 1335 | { |
| 1336 | struct kcm_sock *tkcm; |
| 1337 | struct list_head *head; |
| 1338 | int index = 0; |
| 1339 | |
Linus Torvalds | a11e1d4 | 2018-06-28 09:43:44 -0700 | [diff] [blame] | 1340 | /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so |
| 1341 | * we set sk_state, otherwise epoll_wait always returns right away with |
| 1342 | * EPOLLHUP |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1343 | */ |
| 1344 | kcm->sk.sk_state = TCP_ESTABLISHED; |
| 1345 | |
| 1346 | /* Add to mux's kcm sockets list */ |
| 1347 | kcm->mux = mux; |
| 1348 | spin_lock_bh(&mux->lock); |
| 1349 | |
| 1350 | head = &mux->kcm_socks; |
| 1351 | list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) { |
| 1352 | if (tkcm->index != index) |
| 1353 | break; |
| 1354 | head = &tkcm->kcm_sock_list; |
| 1355 | index++; |
| 1356 | } |
| 1357 | |
| 1358 | list_add(&kcm->kcm_sock_list, head); |
| 1359 | kcm->index = index; |
| 1360 | |
| 1361 | mux->kcm_socks_cnt++; |
| 1362 | spin_unlock_bh(&mux->lock); |
| 1363 | |
| 1364 | INIT_WORK(&kcm->tx_work, kcm_tx_work); |
| 1365 | |
| 1366 | spin_lock_bh(&mux->rx_lock); |
| 1367 | kcm_rcv_ready(kcm); |
| 1368 | spin_unlock_bh(&mux->rx_lock); |
| 1369 | } |
| 1370 | |
| 1371 | static int kcm_attach(struct socket *sock, struct socket *csock, |
| 1372 | struct bpf_prog *prog) |
| 1373 | { |
| 1374 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1375 | struct kcm_mux *mux = kcm->mux; |
| 1376 | struct sock *csk; |
| 1377 | struct kcm_psock *psock = NULL, *tpsock; |
| 1378 | struct list_head *head; |
| 1379 | int index = 0; |
Eric Biggers | 3fd8712 | 2017-08-24 14:38:51 -0700 | [diff] [blame] | 1380 | static const struct strp_callbacks cb = { |
| 1381 | .rcv_msg = kcm_rcv_strparser, |
| 1382 | .parse_msg = kcm_parse_func_strparser, |
| 1383 | .read_sock_done = kcm_read_sock_done, |
| 1384 | }; |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1385 | int err = 0; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1386 | |
| 1387 | csk = csock->sk; |
| 1388 | if (!csk) |
| 1389 | return -EINVAL; |
| 1390 | |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1391 | lock_sock(csk); |
| 1392 | |
Tom Herbert | 581e722 | 2018-01-24 12:35:40 -0800 | [diff] [blame] | 1393 | /* Only allow TCP sockets to be attached for now */ |
| 1394 | if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1395 | csk->sk_protocol != IPPROTO_TCP) { |
| 1396 | err = -EOPNOTSUPP; |
| 1397 | goto out; |
| 1398 | } |
Tom Herbert | 581e722 | 2018-01-24 12:35:40 -0800 | [diff] [blame] | 1399 | |
| 1400 | /* Don't allow listeners or closed sockets */ |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1401 | if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) { |
| 1402 | err = -EOPNOTSUPP; |
| 1403 | goto out; |
| 1404 | } |
Eric Dumazet | 351050e | 2017-08-30 09:29:31 -0700 | [diff] [blame] | 1405 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1406 | psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1407 | if (!psock) { |
| 1408 | err = -ENOMEM; |
| 1409 | goto out; |
| 1410 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1411 | |
| 1412 | psock->mux = mux; |
| 1413 | psock->sk = csk; |
| 1414 | psock->bpf_prog = prog; |
Tom Herbert | 29152a3 | 2016-03-07 14:11:11 -0800 | [diff] [blame] | 1415 | |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 1416 | err = strp_init(&psock->strp, csk, &cb); |
| 1417 | if (err) { |
| 1418 | kmem_cache_free(kcm_psockp, psock); |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1419 | goto out; |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 1420 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1421 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1422 | write_lock_bh(&csk->sk_callback_lock); |
Tom Herbert | e557124 | 2018-01-24 12:35:41 -0800 | [diff] [blame] | 1423 | |
| 1424 | /* Check if sk_user_data is aready by KCM or someone else. |
| 1425 | * Must be done under lock to prevent race conditions. |
| 1426 | */ |
| 1427 | if (csk->sk_user_data) { |
| 1428 | write_unlock_bh(&csk->sk_callback_lock); |
Tom Herbert | dff8baa | 2018-02-14 09:22:42 -0800 | [diff] [blame] | 1429 | strp_stop(&psock->strp); |
Tom Herbert | e557124 | 2018-01-24 12:35:41 -0800 | [diff] [blame] | 1430 | strp_done(&psock->strp); |
| 1431 | kmem_cache_free(kcm_psockp, psock); |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1432 | err = -EALREADY; |
| 1433 | goto out; |
Tom Herbert | e557124 | 2018-01-24 12:35:41 -0800 | [diff] [blame] | 1434 | } |
| 1435 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1436 | psock->save_data_ready = csk->sk_data_ready; |
| 1437 | psock->save_write_space = csk->sk_write_space; |
| 1438 | psock->save_state_change = csk->sk_state_change; |
| 1439 | csk->sk_user_data = psock; |
Tom Herbert | 96a5908 | 2016-08-28 14:43:19 -0700 | [diff] [blame] | 1440 | csk->sk_data_ready = psock_data_ready; |
| 1441 | csk->sk_write_space = psock_write_space; |
| 1442 | csk->sk_state_change = psock_state_change; |
Tom Herbert | e557124 | 2018-01-24 12:35:41 -0800 | [diff] [blame] | 1443 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1444 | write_unlock_bh(&csk->sk_callback_lock); |
| 1445 | |
Tom Herbert | e557124 | 2018-01-24 12:35:41 -0800 | [diff] [blame] | 1446 | sock_hold(csk); |
| 1447 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1448 | /* Finished initialization, now add the psock to the MUX. */ |
| 1449 | spin_lock_bh(&mux->lock); |
| 1450 | head = &mux->psocks; |
| 1451 | list_for_each_entry(tpsock, &mux->psocks, psock_list) { |
| 1452 | if (tpsock->index != index) |
| 1453 | break; |
| 1454 | head = &tpsock->psock_list; |
| 1455 | index++; |
| 1456 | } |
| 1457 | |
| 1458 | list_add(&psock->psock_list, head); |
| 1459 | psock->index = index; |
| 1460 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1461 | KCM_STATS_INCR(mux->stats.psock_attach); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1462 | mux->psocks_cnt++; |
| 1463 | psock_now_avail(psock); |
| 1464 | spin_unlock_bh(&mux->lock); |
| 1465 | |
| 1466 | /* Schedule RX work in case there are already bytes queued */ |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1467 | strp_check_rcv(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1468 | |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1469 | out: |
| 1470 | release_sock(csk); |
| 1471 | |
| 1472 | return err; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1473 | } |
| 1474 | |
| 1475 | static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info) |
| 1476 | { |
| 1477 | struct socket *csock; |
| 1478 | struct bpf_prog *prog; |
| 1479 | int err; |
| 1480 | |
| 1481 | csock = sockfd_lookup(info->fd, &err); |
| 1482 | if (!csock) |
| 1483 | return -ENOENT; |
| 1484 | |
Daniel Borkmann | 113214b | 2016-06-30 17:24:44 +0200 | [diff] [blame] | 1485 | 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] | 1486 | if (IS_ERR(prog)) { |
| 1487 | err = PTR_ERR(prog); |
| 1488 | goto out; |
| 1489 | } |
| 1490 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1491 | err = kcm_attach(sock, csock, prog); |
| 1492 | if (err) { |
| 1493 | bpf_prog_put(prog); |
| 1494 | goto out; |
| 1495 | } |
| 1496 | |
| 1497 | /* Keep reference on file also */ |
| 1498 | |
| 1499 | return 0; |
| 1500 | out: |
| 1501 | fput(csock->file); |
| 1502 | return err; |
| 1503 | } |
| 1504 | |
| 1505 | static void kcm_unattach(struct kcm_psock *psock) |
| 1506 | { |
| 1507 | struct sock *csk = psock->sk; |
| 1508 | struct kcm_mux *mux = psock->mux; |
| 1509 | |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1510 | lock_sock(csk); |
| 1511 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1512 | /* Stop getting callbacks from TCP socket. After this there should |
| 1513 | * be no way to reserve a kcm for this psock. |
| 1514 | */ |
| 1515 | write_lock_bh(&csk->sk_callback_lock); |
| 1516 | csk->sk_user_data = NULL; |
| 1517 | csk->sk_data_ready = psock->save_data_ready; |
| 1518 | csk->sk_write_space = psock->save_write_space; |
| 1519 | csk->sk_state_change = psock->save_state_change; |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1520 | strp_stop(&psock->strp); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1521 | |
| 1522 | if (WARN_ON(psock->rx_kcm)) { |
| 1523 | write_unlock_bh(&csk->sk_callback_lock); |
Tom Herbert | 2cc683e | 2018-03-13 12:01:43 -0700 | [diff] [blame] | 1524 | release_sock(csk); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1525 | return; |
| 1526 | } |
| 1527 | |
| 1528 | spin_lock_bh(&mux->rx_lock); |
| 1529 | |
| 1530 | /* Stop receiver activities. After this point psock should not be |
| 1531 | * able to get onto ready list either through callbacks or work. |
| 1532 | */ |
| 1533 | if (psock->ready_rx_msg) { |
| 1534 | list_del(&psock->psock_ready_list); |
| 1535 | kfree_skb(psock->ready_rx_msg); |
| 1536 | psock->ready_rx_msg = NULL; |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1537 | KCM_STATS_INCR(mux->stats.rx_ready_drops); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1538 | } |
| 1539 | |
| 1540 | spin_unlock_bh(&mux->rx_lock); |
| 1541 | |
| 1542 | write_unlock_bh(&csk->sk_callback_lock); |
| 1543 | |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1544 | /* Call strp_done without sock lock */ |
| 1545 | release_sock(csk); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1546 | strp_done(&psock->strp); |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1547 | lock_sock(csk); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1548 | |
| 1549 | bpf_prog_put(psock->bpf_prog); |
| 1550 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1551 | spin_lock_bh(&mux->lock); |
| 1552 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1553 | aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1554 | save_strp_stats(&psock->strp, &mux->aggregate_strp_stats); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1555 | |
| 1556 | KCM_STATS_INCR(mux->stats.psock_unattach); |
| 1557 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1558 | if (psock->tx_kcm) { |
| 1559 | /* psock was reserved. Just mark it finished and we will clean |
| 1560 | * up in the kcm paths, we need kcm lock which can not be |
| 1561 | * acquired here. |
| 1562 | */ |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1563 | KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1564 | spin_unlock_bh(&mux->lock); |
| 1565 | |
| 1566 | /* We are unattaching a socket that is reserved. Abort the |
| 1567 | * socket since we may be out of sync in sending on it. We need |
| 1568 | * to do this without the mux lock. |
| 1569 | */ |
| 1570 | kcm_abort_tx_psock(psock, EPIPE, false); |
| 1571 | |
| 1572 | spin_lock_bh(&mux->lock); |
| 1573 | if (!psock->tx_kcm) { |
| 1574 | /* psock now unreserved in window mux was unlocked */ |
| 1575 | goto no_reserved; |
| 1576 | } |
| 1577 | psock->done = 1; |
| 1578 | |
| 1579 | /* Commit done before queuing work to process it */ |
| 1580 | smp_mb(); |
| 1581 | |
| 1582 | /* Queue tx work to make sure psock->done is handled */ |
| 1583 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); |
| 1584 | spin_unlock_bh(&mux->lock); |
| 1585 | } else { |
| 1586 | no_reserved: |
| 1587 | if (!psock->tx_stopped) |
| 1588 | list_del(&psock->psock_avail_list); |
| 1589 | list_del(&psock->psock_list); |
| 1590 | mux->psocks_cnt--; |
| 1591 | spin_unlock_bh(&mux->lock); |
| 1592 | |
| 1593 | sock_put(csk); |
| 1594 | fput(csk->sk_socket->file); |
| 1595 | kmem_cache_free(kcm_psockp, psock); |
| 1596 | } |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1597 | |
| 1598 | release_sock(csk); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1599 | } |
| 1600 | |
| 1601 | static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) |
| 1602 | { |
| 1603 | struct kcm_sock *kcm = kcm_sk(sock->sk); |
| 1604 | struct kcm_mux *mux = kcm->mux; |
| 1605 | struct kcm_psock *psock; |
| 1606 | struct socket *csock; |
| 1607 | struct sock *csk; |
| 1608 | int err; |
| 1609 | |
| 1610 | csock = sockfd_lookup(info->fd, &err); |
| 1611 | if (!csock) |
| 1612 | return -ENOENT; |
| 1613 | |
| 1614 | csk = csock->sk; |
| 1615 | if (!csk) { |
| 1616 | err = -EINVAL; |
| 1617 | goto out; |
| 1618 | } |
| 1619 | |
| 1620 | err = -ENOENT; |
| 1621 | |
| 1622 | spin_lock_bh(&mux->lock); |
| 1623 | |
| 1624 | list_for_each_entry(psock, &mux->psocks, psock_list) { |
| 1625 | if (psock->sk != csk) |
| 1626 | continue; |
| 1627 | |
| 1628 | /* Found the matching psock */ |
| 1629 | |
| 1630 | if (psock->unattaching || WARN_ON(psock->done)) { |
| 1631 | err = -EALREADY; |
| 1632 | break; |
| 1633 | } |
| 1634 | |
| 1635 | psock->unattaching = 1; |
| 1636 | |
| 1637 | spin_unlock_bh(&mux->lock); |
| 1638 | |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1639 | /* Lower socket lock should already be held */ |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1640 | kcm_unattach(psock); |
| 1641 | |
| 1642 | err = 0; |
| 1643 | goto out; |
| 1644 | } |
| 1645 | |
| 1646 | spin_unlock_bh(&mux->lock); |
| 1647 | |
| 1648 | out: |
| 1649 | fput(csock->file); |
| 1650 | return err; |
| 1651 | } |
| 1652 | |
| 1653 | static struct proto kcm_proto = { |
| 1654 | .name = "KCM", |
| 1655 | .owner = THIS_MODULE, |
| 1656 | .obj_size = sizeof(struct kcm_sock), |
| 1657 | }; |
| 1658 | |
| 1659 | /* Clone a kcm socket. */ |
Al Viro | a5739435b | 2017-12-05 23:27:57 +0000 | [diff] [blame] | 1660 | static struct file *kcm_clone(struct socket *osock) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1661 | { |
| 1662 | struct socket *newsock; |
| 1663 | struct sock *newsk; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1664 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1665 | newsock = sock_alloc(); |
| 1666 | if (!newsock) |
Al Viro | a5739435b | 2017-12-05 23:27:57 +0000 | [diff] [blame] | 1667 | return ERR_PTR(-ENFILE); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1668 | |
| 1669 | newsock->type = osock->type; |
| 1670 | newsock->ops = osock->ops; |
| 1671 | |
| 1672 | __module_get(newsock->ops->owner); |
| 1673 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1674 | newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, |
Kirill Tkhai | eb7f54b | 2018-06-01 14:30:38 +0300 | [diff] [blame] | 1675 | &kcm_proto, false); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1676 | if (!newsk) { |
Al Viro | a5739435b | 2017-12-05 23:27:57 +0000 | [diff] [blame] | 1677 | sock_release(newsock); |
| 1678 | return ERR_PTR(-ENOMEM); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1679 | } |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1680 | sock_init_data(newsock, newsk); |
| 1681 | init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); |
| 1682 | |
Al Viro | 8e1611e | 2017-12-05 23:29:09 +0000 | [diff] [blame] | 1683 | return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1684 | } |
| 1685 | |
| 1686 | static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
| 1687 | { |
| 1688 | int err; |
| 1689 | |
| 1690 | switch (cmd) { |
| 1691 | case SIOCKCMATTACH: { |
| 1692 | struct kcm_attach info; |
| 1693 | |
| 1694 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) |
WANG Cong | a80db69 | 2017-03-23 11:03:31 -0700 | [diff] [blame] | 1695 | return -EFAULT; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1696 | |
| 1697 | err = kcm_attach_ioctl(sock, &info); |
| 1698 | |
| 1699 | break; |
| 1700 | } |
| 1701 | case SIOCKCMUNATTACH: { |
| 1702 | struct kcm_unattach info; |
| 1703 | |
| 1704 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) |
WANG Cong | a80db69 | 2017-03-23 11:03:31 -0700 | [diff] [blame] | 1705 | return -EFAULT; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1706 | |
| 1707 | err = kcm_unattach_ioctl(sock, &info); |
| 1708 | |
| 1709 | break; |
| 1710 | } |
| 1711 | case SIOCKCMCLONE: { |
| 1712 | struct kcm_clone info; |
Al Viro | a5739435b | 2017-12-05 23:27:57 +0000 | [diff] [blame] | 1713 | struct file *file; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1714 | |
Al Viro | a5739435b | 2017-12-05 23:27:57 +0000 | [diff] [blame] | 1715 | info.fd = get_unused_fd_flags(0); |
| 1716 | if (unlikely(info.fd < 0)) |
| 1717 | return info.fd; |
| 1718 | |
| 1719 | file = kcm_clone(sock); |
| 1720 | if (IS_ERR(file)) { |
| 1721 | put_unused_fd(info.fd); |
| 1722 | return PTR_ERR(file); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1723 | } |
Al Viro | a5739435b | 2017-12-05 23:27:57 +0000 | [diff] [blame] | 1724 | if (copy_to_user((void __user *)arg, &info, |
| 1725 | sizeof(info))) { |
| 1726 | put_unused_fd(info.fd); |
| 1727 | fput(file); |
| 1728 | return -EFAULT; |
| 1729 | } |
| 1730 | fd_install(info.fd, file); |
| 1731 | err = 0; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1732 | break; |
| 1733 | } |
| 1734 | default: |
| 1735 | err = -ENOIOCTLCMD; |
| 1736 | break; |
| 1737 | } |
| 1738 | |
| 1739 | return err; |
| 1740 | } |
| 1741 | |
| 1742 | static void free_mux(struct rcu_head *rcu) |
| 1743 | { |
| 1744 | struct kcm_mux *mux = container_of(rcu, |
| 1745 | struct kcm_mux, rcu); |
| 1746 | |
| 1747 | kmem_cache_free(kcm_muxp, mux); |
| 1748 | } |
| 1749 | |
| 1750 | static void release_mux(struct kcm_mux *mux) |
| 1751 | { |
| 1752 | struct kcm_net *knet = mux->knet; |
| 1753 | struct kcm_psock *psock, *tmp_psock; |
| 1754 | |
| 1755 | /* Release psocks */ |
| 1756 | list_for_each_entry_safe(psock, tmp_psock, |
| 1757 | &mux->psocks, psock_list) { |
Tom Herbert | 1616b38 | 2016-08-23 11:55:31 -0700 | [diff] [blame] | 1758 | if (!WARN_ON(psock->unattaching)) |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1759 | kcm_unattach(psock); |
| 1760 | } |
| 1761 | |
| 1762 | if (WARN_ON(mux->psocks_cnt)) |
| 1763 | return; |
| 1764 | |
| 1765 | __skb_queue_purge(&mux->rx_hold_queue); |
| 1766 | |
| 1767 | mutex_lock(&knet->mutex); |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 1768 | aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats); |
| 1769 | aggregate_psock_stats(&mux->aggregate_psock_stats, |
| 1770 | &knet->aggregate_psock_stats); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1771 | aggregate_strp_stats(&mux->aggregate_strp_stats, |
| 1772 | &knet->aggregate_strp_stats); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1773 | list_del_rcu(&mux->kcm_mux_list); |
| 1774 | knet->count--; |
| 1775 | mutex_unlock(&knet->mutex); |
| 1776 | |
| 1777 | call_rcu(&mux->rcu, free_mux); |
| 1778 | } |
| 1779 | |
| 1780 | static void kcm_done(struct kcm_sock *kcm) |
| 1781 | { |
| 1782 | struct kcm_mux *mux = kcm->mux; |
| 1783 | struct sock *sk = &kcm->sk; |
| 1784 | int socks_cnt; |
| 1785 | |
| 1786 | spin_lock_bh(&mux->rx_lock); |
| 1787 | if (kcm->rx_psock) { |
| 1788 | /* Cleanup in unreserve_rx_kcm */ |
| 1789 | WARN_ON(kcm->done); |
| 1790 | kcm->rx_disabled = 1; |
| 1791 | kcm->done = 1; |
| 1792 | spin_unlock_bh(&mux->rx_lock); |
| 1793 | return; |
| 1794 | } |
| 1795 | |
| 1796 | if (kcm->rx_wait) { |
| 1797 | list_del(&kcm->wait_rx_list); |
| 1798 | kcm->rx_wait = false; |
| 1799 | } |
| 1800 | /* Move any pending receive messages to other kcm sockets */ |
| 1801 | requeue_rx_msgs(mux, &sk->sk_receive_queue); |
| 1802 | |
| 1803 | spin_unlock_bh(&mux->rx_lock); |
| 1804 | |
| 1805 | if (WARN_ON(sk_rmem_alloc_get(sk))) |
| 1806 | return; |
| 1807 | |
| 1808 | /* Detach from MUX */ |
| 1809 | spin_lock_bh(&mux->lock); |
| 1810 | |
| 1811 | list_del(&kcm->kcm_sock_list); |
| 1812 | mux->kcm_socks_cnt--; |
| 1813 | socks_cnt = mux->kcm_socks_cnt; |
| 1814 | |
| 1815 | spin_unlock_bh(&mux->lock); |
| 1816 | |
| 1817 | if (!socks_cnt) { |
| 1818 | /* We are done with the mux now. */ |
| 1819 | release_mux(mux); |
| 1820 | } |
| 1821 | |
| 1822 | WARN_ON(kcm->rx_wait); |
| 1823 | |
| 1824 | sock_put(&kcm->sk); |
| 1825 | } |
| 1826 | |
| 1827 | /* Called by kcm_release to close a KCM socket. |
| 1828 | * If this is the last KCM socket on the MUX, destroy the MUX. |
| 1829 | */ |
| 1830 | static int kcm_release(struct socket *sock) |
| 1831 | { |
| 1832 | struct sock *sk = sock->sk; |
| 1833 | struct kcm_sock *kcm; |
| 1834 | struct kcm_mux *mux; |
| 1835 | struct kcm_psock *psock; |
| 1836 | |
| 1837 | if (!sk) |
| 1838 | return 0; |
| 1839 | |
| 1840 | kcm = kcm_sk(sk); |
| 1841 | mux = kcm->mux; |
| 1842 | |
| 1843 | sock_orphan(sk); |
| 1844 | kfree_skb(kcm->seq_skb); |
| 1845 | |
| 1846 | lock_sock(sk); |
| 1847 | /* Purge queue under lock to avoid race condition with tx_work trying |
| 1848 | * to act when queue is nonempty. If tx_work runs after this point |
| 1849 | * it will just return. |
| 1850 | */ |
| 1851 | __skb_queue_purge(&sk->sk_write_queue); |
Tom Herbert | 9b73896 | 2016-08-15 14:51:02 -0700 | [diff] [blame] | 1852 | |
| 1853 | /* Set tx_stopped. This is checked when psock is bound to a kcm and we |
| 1854 | * get a writespace callback. This prevents further work being queued |
| 1855 | * from the callback (unbinding the psock occurs after canceling work. |
| 1856 | */ |
| 1857 | kcm->tx_stopped = 1; |
| 1858 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1859 | release_sock(sk); |
| 1860 | |
| 1861 | spin_lock_bh(&mux->lock); |
| 1862 | if (kcm->tx_wait) { |
| 1863 | /* Take of tx_wait list, after this point there should be no way |
| 1864 | * that a psock will be assigned to this kcm. |
| 1865 | */ |
| 1866 | list_del(&kcm->wait_psock_list); |
| 1867 | kcm->tx_wait = false; |
| 1868 | } |
| 1869 | spin_unlock_bh(&mux->lock); |
| 1870 | |
| 1871 | /* Cancel work. After this point there should be no outside references |
| 1872 | * to the kcm socket. |
| 1873 | */ |
| 1874 | cancel_work_sync(&kcm->tx_work); |
| 1875 | |
| 1876 | lock_sock(sk); |
| 1877 | psock = kcm->tx_psock; |
| 1878 | if (psock) { |
| 1879 | /* A psock was reserved, so we need to kill it since it |
| 1880 | * may already have some bytes queued from a message. We |
| 1881 | * need to do this after removing kcm from tx_wait list. |
| 1882 | */ |
| 1883 | kcm_abort_tx_psock(psock, EPIPE, false); |
| 1884 | unreserve_psock(kcm); |
| 1885 | } |
| 1886 | release_sock(sk); |
| 1887 | |
| 1888 | WARN_ON(kcm->tx_wait); |
| 1889 | WARN_ON(kcm->tx_psock); |
| 1890 | |
| 1891 | sock->sk = NULL; |
| 1892 | |
| 1893 | kcm_done(kcm); |
| 1894 | |
| 1895 | return 0; |
| 1896 | } |
| 1897 | |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1898 | static const struct proto_ops kcm_dgram_ops = { |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1899 | .family = PF_KCM, |
| 1900 | .owner = THIS_MODULE, |
| 1901 | .release = kcm_release, |
| 1902 | .bind = sock_no_bind, |
| 1903 | .connect = sock_no_connect, |
| 1904 | .socketpair = sock_no_socketpair, |
| 1905 | .accept = sock_no_accept, |
| 1906 | .getname = sock_no_getname, |
Linus Torvalds | a11e1d4 | 2018-06-28 09:43:44 -0700 | [diff] [blame] | 1907 | .poll = datagram_poll, |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1908 | .ioctl = kcm_ioctl, |
| 1909 | .listen = sock_no_listen, |
| 1910 | .shutdown = sock_no_shutdown, |
| 1911 | .setsockopt = kcm_setsockopt, |
| 1912 | .getsockopt = kcm_getsockopt, |
| 1913 | .sendmsg = kcm_sendmsg, |
| 1914 | .recvmsg = kcm_recvmsg, |
| 1915 | .mmap = sock_no_mmap, |
Tom Herbert | f29698fc | 2016-03-07 14:11:09 -0800 | [diff] [blame] | 1916 | .sendpage = kcm_sendpage, |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1917 | }; |
| 1918 | |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1919 | static const struct proto_ops kcm_seqpacket_ops = { |
| 1920 | .family = PF_KCM, |
| 1921 | .owner = THIS_MODULE, |
| 1922 | .release = kcm_release, |
| 1923 | .bind = sock_no_bind, |
| 1924 | .connect = sock_no_connect, |
| 1925 | .socketpair = sock_no_socketpair, |
| 1926 | .accept = sock_no_accept, |
| 1927 | .getname = sock_no_getname, |
Linus Torvalds | a11e1d4 | 2018-06-28 09:43:44 -0700 | [diff] [blame] | 1928 | .poll = datagram_poll, |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1929 | .ioctl = kcm_ioctl, |
| 1930 | .listen = sock_no_listen, |
| 1931 | .shutdown = sock_no_shutdown, |
| 1932 | .setsockopt = kcm_setsockopt, |
| 1933 | .getsockopt = kcm_getsockopt, |
| 1934 | .sendmsg = kcm_sendmsg, |
| 1935 | .recvmsg = kcm_recvmsg, |
| 1936 | .mmap = sock_no_mmap, |
Tom Herbert | f29698fc | 2016-03-07 14:11:09 -0800 | [diff] [blame] | 1937 | .sendpage = kcm_sendpage, |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1938 | .splice_read = kcm_splice_read, |
| 1939 | }; |
| 1940 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1941 | /* Create proto operation for kcm sockets */ |
| 1942 | static int kcm_create(struct net *net, struct socket *sock, |
| 1943 | int protocol, int kern) |
| 1944 | { |
| 1945 | struct kcm_net *knet = net_generic(net, kcm_net_id); |
| 1946 | struct sock *sk; |
| 1947 | struct kcm_mux *mux; |
| 1948 | |
| 1949 | switch (sock->type) { |
| 1950 | case SOCK_DGRAM: |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1951 | sock->ops = &kcm_dgram_ops; |
| 1952 | break; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1953 | case SOCK_SEQPACKET: |
Tom Herbert | 9168735 | 2016-03-07 14:11:08 -0800 | [diff] [blame] | 1954 | sock->ops = &kcm_seqpacket_ops; |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 1955 | break; |
| 1956 | default: |
| 1957 | return -ESOCKTNOSUPPORT; |
| 1958 | } |
| 1959 | |
| 1960 | if (protocol != KCMPROTO_CONNECTED) |
| 1961 | return -EPROTONOSUPPORT; |
| 1962 | |
| 1963 | sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern); |
| 1964 | if (!sk) |
| 1965 | return -ENOMEM; |
| 1966 | |
| 1967 | /* Allocate a kcm mux, shared between KCM sockets */ |
| 1968 | mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL); |
| 1969 | if (!mux) { |
| 1970 | sk_free(sk); |
| 1971 | return -ENOMEM; |
| 1972 | } |
| 1973 | |
| 1974 | spin_lock_init(&mux->lock); |
| 1975 | spin_lock_init(&mux->rx_lock); |
| 1976 | INIT_LIST_HEAD(&mux->kcm_socks); |
| 1977 | INIT_LIST_HEAD(&mux->kcm_rx_waiters); |
| 1978 | INIT_LIST_HEAD(&mux->kcm_tx_waiters); |
| 1979 | |
| 1980 | INIT_LIST_HEAD(&mux->psocks); |
| 1981 | INIT_LIST_HEAD(&mux->psocks_ready); |
| 1982 | INIT_LIST_HEAD(&mux->psocks_avail); |
| 1983 | |
| 1984 | mux->knet = knet; |
| 1985 | |
| 1986 | /* Add new MUX to list */ |
| 1987 | mutex_lock(&knet->mutex); |
| 1988 | list_add_rcu(&mux->kcm_mux_list, &knet->mux_list); |
| 1989 | knet->count++; |
| 1990 | mutex_unlock(&knet->mutex); |
| 1991 | |
| 1992 | skb_queue_head_init(&mux->rx_hold_queue); |
| 1993 | |
| 1994 | /* Init KCM socket */ |
| 1995 | sock_init_data(sock, sk); |
| 1996 | init_kcm_sock(kcm_sk(sk), mux); |
| 1997 | |
| 1998 | return 0; |
| 1999 | } |
| 2000 | |
linzhang | 173e783 | 2017-05-15 10:26:47 +0800 | [diff] [blame] | 2001 | static const struct net_proto_family kcm_family_ops = { |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2002 | .family = PF_KCM, |
| 2003 | .create = kcm_create, |
| 2004 | .owner = THIS_MODULE, |
| 2005 | }; |
| 2006 | |
| 2007 | static __net_init int kcm_init_net(struct net *net) |
| 2008 | { |
| 2009 | struct kcm_net *knet = net_generic(net, kcm_net_id); |
| 2010 | |
| 2011 | INIT_LIST_HEAD_RCU(&knet->mux_list); |
| 2012 | mutex_init(&knet->mutex); |
| 2013 | |
| 2014 | return 0; |
| 2015 | } |
| 2016 | |
| 2017 | static __net_exit void kcm_exit_net(struct net *net) |
| 2018 | { |
| 2019 | struct kcm_net *knet = net_generic(net, kcm_net_id); |
| 2020 | |
| 2021 | /* All KCM sockets should be closed at this point, which should mean |
| 2022 | * that all multiplexors and psocks have been destroyed. |
| 2023 | */ |
| 2024 | WARN_ON(!list_empty(&knet->mux_list)); |
| 2025 | } |
| 2026 | |
| 2027 | static struct pernet_operations kcm_net_ops = { |
| 2028 | .init = kcm_init_net, |
| 2029 | .exit = kcm_exit_net, |
| 2030 | .id = &kcm_net_id, |
| 2031 | .size = sizeof(struct kcm_net), |
| 2032 | }; |
| 2033 | |
| 2034 | static int __init kcm_init(void) |
| 2035 | { |
| 2036 | int err = -ENOMEM; |
| 2037 | |
| 2038 | kcm_muxp = kmem_cache_create("kcm_mux_cache", |
| 2039 | sizeof(struct kcm_mux), 0, |
YueHaibing | c211524 | 2019-02-22 14:15:30 +0800 | [diff] [blame] | 2040 | SLAB_HWCACHE_ALIGN, NULL); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2041 | if (!kcm_muxp) |
| 2042 | goto fail; |
| 2043 | |
| 2044 | kcm_psockp = kmem_cache_create("kcm_psock_cache", |
| 2045 | sizeof(struct kcm_psock), 0, |
YueHaibing | c211524 | 2019-02-22 14:15:30 +0800 | [diff] [blame] | 2046 | SLAB_HWCACHE_ALIGN, NULL); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2047 | if (!kcm_psockp) |
| 2048 | goto fail; |
| 2049 | |
| 2050 | kcm_wq = create_singlethread_workqueue("kkcmd"); |
| 2051 | if (!kcm_wq) |
| 2052 | goto fail; |
| 2053 | |
| 2054 | err = proto_register(&kcm_proto, 1); |
| 2055 | if (err) |
| 2056 | goto fail; |
| 2057 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2058 | err = register_pernet_device(&kcm_net_ops); |
| 2059 | if (err) |
| 2060 | goto net_ops_fail; |
| 2061 | |
Jiri Slaby | 3c446e6 | 2019-03-29 12:19:46 +0100 | [diff] [blame] | 2062 | err = sock_register(&kcm_family_ops); |
| 2063 | if (err) |
| 2064 | goto sock_register_fail; |
| 2065 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 2066 | err = kcm_proc_init(); |
| 2067 | if (err) |
| 2068 | goto proc_init_fail; |
| 2069 | |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2070 | return 0; |
| 2071 | |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 2072 | proc_init_fail: |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2073 | sock_unregister(PF_KCM); |
| 2074 | |
| 2075 | sock_register_fail: |
Jiri Slaby | 3c446e6 | 2019-03-29 12:19:46 +0100 | [diff] [blame] | 2076 | unregister_pernet_device(&kcm_net_ops); |
| 2077 | |
| 2078 | net_ops_fail: |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2079 | proto_unregister(&kcm_proto); |
| 2080 | |
| 2081 | fail: |
| 2082 | kmem_cache_destroy(kcm_muxp); |
| 2083 | kmem_cache_destroy(kcm_psockp); |
| 2084 | |
| 2085 | if (kcm_wq) |
| 2086 | destroy_workqueue(kcm_wq); |
| 2087 | |
| 2088 | return err; |
| 2089 | } |
| 2090 | |
| 2091 | static void __exit kcm_exit(void) |
| 2092 | { |
Tom Herbert | cd6e111 | 2016-03-07 14:11:07 -0800 | [diff] [blame] | 2093 | kcm_proc_exit(); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2094 | sock_unregister(PF_KCM); |
Jiri Slaby | 3c446e6 | 2019-03-29 12:19:46 +0100 | [diff] [blame] | 2095 | unregister_pernet_device(&kcm_net_ops); |
Tom Herbert | ab7ac4e | 2016-03-07 14:11:06 -0800 | [diff] [blame] | 2096 | proto_unregister(&kcm_proto); |
| 2097 | destroy_workqueue(kcm_wq); |
| 2098 | |
| 2099 | kmem_cache_destroy(kcm_muxp); |
| 2100 | kmem_cache_destroy(kcm_psockp); |
| 2101 | } |
| 2102 | |
| 2103 | module_init(kcm_init); |
| 2104 | module_exit(kcm_exit); |
| 2105 | |
| 2106 | MODULE_LICENSE("GPL"); |
| 2107 | MODULE_ALIAS_NETPROTO(PF_KCM); |