| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Tom Herbert | 7528 | 91.18% | 12 | 20.34% |
| David Howells | 360 | 4.36% | 5 | 8.47% |
| Al Viro | 92 | 1.11% | 2 | 3.39% |
| Américo Wang | 69 | 0.84% | 7 | 11.86% |
| Eric Dumazet | 58 | 0.70% | 4 | 6.78% |
| Mina Almasry | 23 | 0.28% | 2 | 3.39% |
| Eric Biggers | 19 | 0.23% | 1 | 1.69% |
| Jiri Slaby | 18 | 0.22% | 1 | 1.69% |
| Kuniyuki Iwashima | 13 | 0.16% | 1 | 1.69% |
| Gavrilov Ilia | 10 | 0.12% | 1 | 1.69% |
| Shigeru Yoshida | 7 | 0.08% | 2 | 3.39% |
| Linus Torvalds | 6 | 0.07% | 2 | 3.39% |
| Peilin Ye | 5 | 0.06% | 1 | 1.69% |
| Jakub Kiciński | 5 | 0.06% | 1 | 1.69% |
| Chas Williams | 5 | 0.06% | 1 | 1.69% |
| Sowmini Varadhan | 5 | 0.06% | 1 | 1.69% |
| Christoph Hellwig | 4 | 0.05% | 1 | 1.69% |
| Linus Torvalds (pre-git) | 3 | 0.04% | 1 | 1.69% |
| Satoru Moriya | 3 | 0.04% | 1 | 1.69% |
| Ingo Molnar | 3 | 0.04% | 1 | 1.69% |
| Daniel Borkmann | 3 | 0.04% | 1 | 1.69% |
| Matthew Wilcox | 2 | 0.02% | 1 | 1.69% |
| Sami Tolvanen | 2 | 0.02% | 1 | 1.69% |
| Zheng Yongjun | 2 | 0.02% | 1 | 1.69% |
| Kunwu Chan | 2 | 0.02% | 1 | 1.69% |
| Jonathan Lemon | 2 | 0.02% | 1 | 1.69% |
| Thomas Gleixner | 2 | 0.02% | 1 | 1.69% |
| Bhaskar Chowdhury | 2 | 0.02% | 1 | 1.69% |
| Kirill V Tkhai | 1 | 0.01% | 1 | 1.69% |
| David S. Miller | 1 | 0.01% | 1 | 1.69% |
| Lin Zhang | 1 | 0.01% | 1 | 1.69% |
| Total | 8256 | 59 |
// SPDX-License-Identifier: GPL-2.0-only /* * Kernel Connection Multiplexor * * Copyright (c) 2016 Tom Herbert <tom@herbertland.com> */ #include <linux/bpf.h> #include <linux/errno.h> #include <linux/errqueue.h> #include <linux/file.h> #include <linux/filter.h> #include <linux/in.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/net.h> #include <linux/netdevice.h> #include <linux/poll.h> #include <linux/rculist.h> #include <linux/skbuff.h> #include <linux/socket.h> #include <linux/uaccess.h> #include <linux/workqueue.h> #include <linux/syscalls.h> #include <linux/sched/signal.h> #include <net/kcm.h> #include <net/netns/generic.h> #include <net/sock.h> #include <uapi/linux/kcm.h> #include <trace/events/sock.h> unsigned int kcm_net_id; static struct kmem_cache *kcm_psockp __read_mostly; static struct kmem_cache *kcm_muxp __read_mostly; static struct workqueue_struct *kcm_wq; static inline struct kcm_sock *kcm_sk(const struct sock *sk) { return (struct kcm_sock *)sk; } static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb) { return (struct kcm_tx_msg *)skb->cb; } static void report_csk_error(struct sock *csk, int err) { csk->sk_err = EPIPE; sk_error_report(csk); } static void kcm_abort_tx_psock(struct kcm_psock *psock, int err, bool wakeup_kcm) { struct sock *csk = psock->sk; struct kcm_mux *mux = psock->mux; /* Unrecoverable error in transmit */ spin_lock_bh(&mux->lock); if (psock->tx_stopped) { spin_unlock_bh(&mux->lock); return; } psock->tx_stopped = 1; KCM_STATS_INCR(psock->stats.tx_aborts); if (!psock->tx_kcm) { /* Take off psocks_avail list */ list_del(&psock->psock_avail_list); } else if (wakeup_kcm) { /* In this case psock is being aborted while outside of * write_msgs and psock is reserved. Schedule tx_work * to handle the failure there. Need to commit tx_stopped * before queuing work. */ smp_mb(); queue_work(kcm_wq, &psock->tx_kcm->tx_work); } spin_unlock_bh(&mux->lock); /* Report error on lower socket */ report_csk_error(csk, err); } /* RX mux lock held. */ static void kcm_update_rx_mux_stats(struct kcm_mux *mux, struct kcm_psock *psock) { STRP_STATS_ADD(mux->stats.rx_bytes, psock->strp.stats.bytes - psock->saved_rx_bytes); mux->stats.rx_msgs += psock->strp.stats.msgs - psock->saved_rx_msgs; psock->saved_rx_msgs = psock->strp.stats.msgs; psock->saved_rx_bytes = psock->strp.stats.bytes; } static void kcm_update_tx_mux_stats(struct kcm_mux *mux, struct kcm_psock *psock) { KCM_STATS_ADD(mux->stats.tx_bytes, psock->stats.tx_bytes - psock->saved_tx_bytes); mux->stats.tx_msgs += psock->stats.tx_msgs - psock->saved_tx_msgs; psock->saved_tx_msgs = psock->stats.tx_msgs; psock->saved_tx_bytes = psock->stats.tx_bytes; } static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); /* KCM is ready to receive messages on its queue-- either the KCM is new or * has become unblocked after being blocked on full socket buffer. Queue any * pending ready messages on a psock. RX mux lock held. */ static void kcm_rcv_ready(struct kcm_sock *kcm) { struct kcm_mux *mux = kcm->mux; struct kcm_psock *psock; struct sk_buff *skb; if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled)) return; while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) { if (kcm_queue_rcv_skb(&kcm->sk, skb)) { /* Assuming buffer limit has been reached */ skb_queue_head(&mux->rx_hold_queue, skb); WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); return; } } while (!list_empty(&mux->psocks_ready)) { psock = list_first_entry(&mux->psocks_ready, struct kcm_psock, psock_ready_list); if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) { /* Assuming buffer limit has been reached */ WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); return; } /* Consumed the ready message on the psock. Schedule rx_work to * get more messages. */ list_del(&psock->psock_ready_list); psock->ready_rx_msg = NULL; /* Commit clearing of ready_rx_msg for queuing work */ smp_mb(); strp_unpause(&psock->strp); strp_check_rcv(&psock->strp); } /* Buffer limit is okay now, add to ready list */ list_add_tail(&kcm->wait_rx_list, &kcm->mux->kcm_rx_waiters); /* paired with lockless reads in kcm_rfree() */ WRITE_ONCE(kcm->rx_wait, true); } static void kcm_rfree(struct sk_buff *skb) { struct sock *sk = skb->sk; struct kcm_sock *kcm = kcm_sk(sk); struct kcm_mux *mux = kcm->mux; unsigned int len = skb->truesize; sk_mem_uncharge(sk, len); atomic_sub(len, &sk->sk_rmem_alloc); /* For reading rx_wait and rx_psock without holding lock */ smp_mb__after_atomic(); if (!READ_ONCE(kcm->rx_wait) && !READ_ONCE(kcm->rx_psock) && sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) { spin_lock_bh(&mux->rx_lock); kcm_rcv_ready(kcm); spin_unlock_bh(&mux->rx_lock); } } static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) { struct sk_buff_head *list = &sk->sk_receive_queue; if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) return -ENOMEM; if (!sk_rmem_schedule(sk, skb, skb->truesize)) return -ENOBUFS; skb->dev = NULL; skb_orphan(skb); skb->sk = sk; skb->destructor = kcm_rfree; atomic_add(skb->truesize, &sk->sk_rmem_alloc); sk_mem_charge(sk, skb->truesize); skb_queue_tail(list, skb); if (!sock_flag(sk, SOCK_DEAD)) sk->sk_data_ready(sk); return 0; } /* Requeue received messages for a kcm socket to other kcm sockets. This is * called with a kcm socket is receive disabled. * RX mux lock held. */ static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head) { struct sk_buff *skb; struct kcm_sock *kcm; while ((skb = skb_dequeue(head))) { /* Reset destructor to avoid calling kcm_rcv_ready */ skb->destructor = sock_rfree; skb_orphan(skb); try_again: if (list_empty(&mux->kcm_rx_waiters)) { skb_queue_tail(&mux->rx_hold_queue, skb); continue; } kcm = list_first_entry(&mux->kcm_rx_waiters, struct kcm_sock, wait_rx_list); if (kcm_queue_rcv_skb(&kcm->sk, skb)) { /* Should mean socket buffer full */ list_del(&kcm->wait_rx_list); /* paired with lockless reads in kcm_rfree() */ WRITE_ONCE(kcm->rx_wait, false); /* Commit rx_wait to read in kcm_free */ smp_wmb(); goto try_again; } } } /* Lower sock lock held */ static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock, struct sk_buff *head) { struct kcm_mux *mux = psock->mux; struct kcm_sock *kcm; WARN_ON(psock->ready_rx_msg); if (psock->rx_kcm) return psock->rx_kcm; spin_lock_bh(&mux->rx_lock); if (psock->rx_kcm) { spin_unlock_bh(&mux->rx_lock); return psock->rx_kcm; } kcm_update_rx_mux_stats(mux, psock); if (list_empty(&mux->kcm_rx_waiters)) { psock->ready_rx_msg = head; strp_pause(&psock->strp); list_add_tail(&psock->psock_ready_list, &mux->psocks_ready); spin_unlock_bh(&mux->rx_lock); return NULL; } kcm = list_first_entry(&mux->kcm_rx_waiters, struct kcm_sock, wait_rx_list); list_del(&kcm->wait_rx_list); /* paired with lockless reads in kcm_rfree() */ WRITE_ONCE(kcm->rx_wait, false); psock->rx_kcm = kcm; /* paired with lockless reads in kcm_rfree() */ WRITE_ONCE(kcm->rx_psock, psock); spin_unlock_bh(&mux->rx_lock); return kcm; } static void kcm_done(struct kcm_sock *kcm); static void kcm_done_work(struct work_struct *w) { kcm_done(container_of(w, struct kcm_sock, done_work)); } /* Lower sock held */ static void unreserve_rx_kcm(struct kcm_psock *psock, bool rcv_ready) { struct kcm_sock *kcm = psock->rx_kcm; struct kcm_mux *mux = psock->mux; if (!kcm) return; spin_lock_bh(&mux->rx_lock); psock->rx_kcm = NULL; /* paired with lockless reads in kcm_rfree() */ WRITE_ONCE(kcm->rx_psock, NULL); /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with * kcm_rfree */ smp_mb(); if (unlikely(kcm->done)) { spin_unlock_bh(&mux->rx_lock); /* Need to run kcm_done in a task since we need to qcquire * callback locks which may already be held here. */ INIT_WORK(&kcm->done_work, kcm_done_work); schedule_work(&kcm->done_work); return; } if (unlikely(kcm->rx_disabled)) { requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) { /* Check for degenerative race with rx_wait that all * data was dequeued (accounted for in kcm_rfree). */ kcm_rcv_ready(kcm); } spin_unlock_bh(&mux->rx_lock); } /* Lower sock lock held */ static void psock_data_ready(struct sock *sk) { struct kcm_psock *psock; trace_sk_data_ready(sk); read_lock_bh(&sk->sk_callback_lock); psock = (struct kcm_psock *)sk->sk_user_data; if (likely(psock)) strp_data_ready(&psock->strp); read_unlock_bh(&sk->sk_callback_lock); } /* Called with lower sock held */ static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb) { struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); struct kcm_sock *kcm; try_queue: kcm = reserve_rx_kcm(psock, skb); if (!kcm) { /* Unable to reserve a KCM, message is held in psock and strp * is paused. */ return; } if (kcm_queue_rcv_skb(&kcm->sk, skb)) { /* Should mean socket buffer full */ unreserve_rx_kcm(psock, false); goto try_queue; } } static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb) { struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); struct bpf_prog *prog = psock->bpf_prog; int res; res = bpf_prog_run_pin_on_cpu(prog, skb); return res; } static int kcm_read_sock_done(struct strparser *strp, int err) { struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); unreserve_rx_kcm(psock, true); return err; } static void psock_state_change(struct sock *sk) { /* TCP only does a EPOLLIN for a half close. Do a EPOLLHUP here * since application will normally not poll with EPOLLIN * on the TCP sockets. */ report_csk_error(sk, EPIPE); } static void psock_write_space(struct sock *sk) { struct kcm_psock *psock; struct kcm_mux *mux; struct kcm_sock *kcm; read_lock_bh(&sk->sk_callback_lock); psock = (struct kcm_psock *)sk->sk_user_data; if (unlikely(!psock)) goto out; mux = psock->mux; spin_lock_bh(&mux->lock); /* Check if the socket is reserved so someone is waiting for sending. */ kcm = psock->tx_kcm; if (kcm && !unlikely(kcm->tx_stopped)) queue_work(kcm_wq, &kcm->tx_work); spin_unlock_bh(&mux->lock); out: read_unlock_bh(&sk->sk_callback_lock); } static void unreserve_psock(struct kcm_sock *kcm); /* kcm sock is locked. */ static struct kcm_psock *reserve_psock(struct kcm_sock *kcm) { struct kcm_mux *mux = kcm->mux; struct kcm_psock *psock; psock = kcm->tx_psock; smp_rmb(); /* Must read tx_psock before tx_wait */ if (psock) { WARN_ON(kcm->tx_wait); if (unlikely(psock->tx_stopped)) unreserve_psock(kcm); else return kcm->tx_psock; } spin_lock_bh(&mux->lock); /* Check again under lock to see if psock was reserved for this * psock via psock_unreserve. */ psock = kcm->tx_psock; if (unlikely(psock)) { WARN_ON(kcm->tx_wait); spin_unlock_bh(&mux->lock); return kcm->tx_psock; } if (!list_empty(&mux->psocks_avail)) { psock = list_first_entry(&mux->psocks_avail, struct kcm_psock, psock_avail_list); list_del(&psock->psock_avail_list); if (kcm->tx_wait) { list_del(&kcm->wait_psock_list); kcm->tx_wait = false; } kcm->tx_psock = psock; psock->tx_kcm = kcm; KCM_STATS_INCR(psock->stats.reserved); } else if (!kcm->tx_wait) { list_add_tail(&kcm->wait_psock_list, &mux->kcm_tx_waiters); kcm->tx_wait = true; } spin_unlock_bh(&mux->lock); return psock; } /* mux lock held */ static void psock_now_avail(struct kcm_psock *psock) { struct kcm_mux *mux = psock->mux; struct kcm_sock *kcm; if (list_empty(&mux->kcm_tx_waiters)) { list_add_tail(&psock->psock_avail_list, &mux->psocks_avail); } else { kcm = list_first_entry(&mux->kcm_tx_waiters, struct kcm_sock, wait_psock_list); list_del(&kcm->wait_psock_list); kcm->tx_wait = false; psock->tx_kcm = kcm; /* Commit before changing tx_psock since that is read in * reserve_psock before queuing work. */ smp_mb(); kcm->tx_psock = psock; KCM_STATS_INCR(psock->stats.reserved); queue_work(kcm_wq, &kcm->tx_work); } } /* kcm sock is locked. */ static void unreserve_psock(struct kcm_sock *kcm) { struct kcm_psock *psock; struct kcm_mux *mux = kcm->mux; spin_lock_bh(&mux->lock); psock = kcm->tx_psock; if (WARN_ON(!psock)) { spin_unlock_bh(&mux->lock); return; } smp_rmb(); /* Read tx_psock before tx_wait */ kcm_update_tx_mux_stats(mux, psock); WARN_ON(kcm->tx_wait); kcm->tx_psock = NULL; psock->tx_kcm = NULL; KCM_STATS_INCR(psock->stats.unreserved); if (unlikely(psock->tx_stopped)) { if (psock->done) { /* Deferred free */ list_del(&psock->psock_list); mux->psocks_cnt--; sock_put(psock->sk); fput(psock->sk->sk_socket->file); kmem_cache_free(kcm_psockp, psock); } /* Don't put back on available list */ spin_unlock_bh(&mux->lock); return; } psock_now_avail(psock); spin_unlock_bh(&mux->lock); } static void kcm_report_tx_retry(struct kcm_sock *kcm) { struct kcm_mux *mux = kcm->mux; spin_lock_bh(&mux->lock); KCM_STATS_INCR(mux->stats.tx_retries); spin_unlock_bh(&mux->lock); } /* Write any messages ready on the kcm socket. Called with kcm sock lock * held. Return bytes actually sent or error. */ static int kcm_write_msgs(struct kcm_sock *kcm) { unsigned int total_sent = 0; struct sock *sk = &kcm->sk; struct kcm_psock *psock; struct sk_buff *head; int ret = 0; kcm->tx_wait_more = false; psock = kcm->tx_psock; if (unlikely(psock && psock->tx_stopped)) { /* A reserved psock was aborted asynchronously. Unreserve * it and we'll retry the message. */ unreserve_psock(kcm); kcm_report_tx_retry(kcm); if (skb_queue_empty(&sk->sk_write_queue)) return 0; kcm_tx_msg(skb_peek(&sk->sk_write_queue))->started_tx = false; } retry: while ((head = skb_peek(&sk->sk_write_queue))) { struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_SPLICE_PAGES, }; struct kcm_tx_msg *txm = kcm_tx_msg(head); struct sk_buff *skb; unsigned int msize; int i; if (!txm->started_tx) { psock = reserve_psock(kcm); if (!psock) goto out; skb = head; txm->frag_offset = 0; txm->sent = 0; txm->started_tx = true; } else { if (WARN_ON(!psock)) { ret = -EINVAL; goto out; } skb = txm->frag_skb; } if (WARN_ON(!skb_shinfo(skb)->nr_frags) || WARN_ON_ONCE(!skb_frag_page(&skb_shinfo(skb)->frags[0]))) { ret = -EINVAL; goto out; } msize = 0; for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) msize += skb_frag_size(&skb_shinfo(skb)->frags[i]); iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, (const struct bio_vec *)skb_shinfo(skb)->frags, skb_shinfo(skb)->nr_frags, msize); iov_iter_advance(&msg.msg_iter, txm->frag_offset); do { ret = sock_sendmsg(psock->sk->sk_socket, &msg); if (ret <= 0) { if (ret == -EAGAIN) { /* Save state to try again when there's * write space on the socket */ txm->frag_skb = skb; ret = 0; goto out; } /* Hard failure in sending message, abort this * psock since it has lost framing * synchronization and retry sending the * message from the beginning. */ kcm_abort_tx_psock(psock, ret ? -ret : EPIPE, true); unreserve_psock(kcm); psock = NULL; txm->started_tx = false; kcm_report_tx_retry(kcm); ret = 0; goto retry; } txm->sent += ret; txm->frag_offset += ret; KCM_STATS_ADD(psock->stats.tx_bytes, ret); } while (msg.msg_iter.count > 0); if (skb == head) { if (skb_has_frag_list(skb)) { txm->frag_skb = skb_shinfo(skb)->frag_list; txm->frag_offset = 0; continue; } } else if (skb->next) { txm->frag_skb = skb->next; txm->frag_offset = 0; continue; } /* Successfully sent the whole packet, account for it. */ sk->sk_wmem_queued -= txm->sent; total_sent += txm->sent; skb_dequeue(&sk->sk_write_queue); kfree_skb(head); KCM_STATS_INCR(psock->stats.tx_msgs); } out: if (!head) { /* Done with all queued messages. */ WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); if (psock) unreserve_psock(kcm); } /* Check if write space is available */ sk->sk_write_space(sk); return total_sent ? : ret; } static void kcm_tx_work(struct work_struct *w) { struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work); struct sock *sk = &kcm->sk; int err; lock_sock(sk); /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx * aborts */ err = kcm_write_msgs(kcm); if (err < 0) { /* Hard failure in write, report error on KCM socket */ pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err); report_csk_error(&kcm->sk, -err); goto out; } /* Primarily for SOCK_SEQPACKET sockets */ if (likely(sk->sk_socket) && test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags); sk->sk_write_space(sk); } out: release_sock(sk); } static void kcm_push(struct kcm_sock *kcm) { if (kcm->tx_wait_more) kcm_write_msgs(kcm); } static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; struct kcm_sock *kcm = kcm_sk(sk); struct sk_buff *skb = NULL, *head = NULL; size_t copy, copied = 0; long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); int eor = (sock->type == SOCK_DGRAM) ? !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR); int err = -EPIPE; lock_sock(sk); /* Per tcp_sendmsg this should be in poll */ sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); if (sk->sk_err) goto out_error; if (kcm->seq_skb) { /* Previously opened message */ head = kcm->seq_skb; skb = kcm_tx_msg(head)->last_skb; goto start; } /* Call the sk_stream functions to manage the sndbuf mem. */ if (!sk_stream_memory_free(sk)) { kcm_push(kcm); set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); err = sk_stream_wait_memory(sk, &timeo); if (err) goto out_error; } if (msg_data_left(msg)) { /* New message, alloc head skb */ head = alloc_skb(0, sk->sk_allocation); while (!head) { kcm_push(kcm); err = sk_stream_wait_memory(sk, &timeo); if (err) goto out_error; head = alloc_skb(0, sk->sk_allocation); } skb = head; /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling * csum_and_copy_from_iter from skb_do_copy_data_nocache. */ skb->ip_summed = CHECKSUM_UNNECESSARY; } start: while (msg_data_left(msg)) { bool merge = true; int i = skb_shinfo(skb)->nr_frags; struct page_frag *pfrag = sk_page_frag(sk); if (!sk_page_frag_refill(sk, pfrag)) goto wait_for_memory; if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { if (i == MAX_SKB_FRAGS) { struct sk_buff *tskb; tskb = alloc_skb(0, sk->sk_allocation); if (!tskb) goto wait_for_memory; if (head == skb) skb_shinfo(head)->frag_list = tskb; else skb->next = tskb; skb = tskb; skb->ip_summed = CHECKSUM_UNNECESSARY; continue; } merge = false; } if (msg->msg_flags & MSG_SPLICE_PAGES) { copy = msg_data_left(msg); if (!sk_wmem_schedule(sk, copy)) goto wait_for_memory; err = skb_splice_from_iter(skb, &msg->msg_iter, copy, sk->sk_allocation); if (err < 0) { if (err == -EMSGSIZE) goto wait_for_memory; goto out_error; } copy = err; skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; sk_wmem_queued_add(sk, copy); sk_mem_charge(sk, copy); if (head != skb) head->truesize += copy; } else { copy = min_t(int, msg_data_left(msg), pfrag->size - pfrag->offset); if (!sk_wmem_schedule(sk, copy)) goto wait_for_memory; err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, pfrag->page, pfrag->offset, copy); if (err) goto out_error; /* Update the skb. */ if (merge) { skb_frag_size_add( &skb_shinfo(skb)->frags[i - 1], copy); } else { skb_fill_page_desc(skb, i, pfrag->page, pfrag->offset, copy); get_page(pfrag->page); } pfrag->offset += copy; } copied += copy; if (head != skb) { head->len += copy; head->data_len += copy; } continue; wait_for_memory: kcm_push(kcm); err = sk_stream_wait_memory(sk, &timeo); if (err) goto out_error; } if (eor) { bool not_busy = skb_queue_empty(&sk->sk_write_queue); if (head) { /* Message complete, queue it on send buffer */ __skb_queue_tail(&sk->sk_write_queue, head); kcm->seq_skb = NULL; KCM_STATS_INCR(kcm->stats.tx_msgs); } if (msg->msg_flags & MSG_BATCH) { kcm->tx_wait_more = true; } else if (kcm->tx_wait_more || not_busy) { err = kcm_write_msgs(kcm); if (err < 0) { /* We got a hard error in write_msgs but have * already queued this message. Report an error * in the socket, but don't affect return value * from sendmsg */ pr_warn("KCM: Hard failure on kcm_write_msgs\n"); report_csk_error(&kcm->sk, -err); } } } else { /* Message not complete, save state */ partial_message: if (head) { kcm->seq_skb = head; kcm_tx_msg(head)->last_skb = skb; } } KCM_STATS_ADD(kcm->stats.tx_bytes, copied); release_sock(sk); return copied; out_error: kcm_push(kcm); if (sock->type == SOCK_SEQPACKET) { /* Wrote some bytes before encountering an * error, return partial success. */ if (copied) goto partial_message; if (head != kcm->seq_skb) kfree_skb(head); } else { kfree_skb(head); kcm->seq_skb = NULL; } err = sk_stream_error(sk, msg->msg_flags, err); /* make sure we wake any epoll edge trigger waiter */ if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) sk->sk_write_space(sk); release_sock(sk); return err; } static void kcm_splice_eof(struct socket *sock) { struct sock *sk = sock->sk; struct kcm_sock *kcm = kcm_sk(sk); if (skb_queue_empty_lockless(&sk->sk_write_queue)) return; lock_sock(sk); kcm_write_msgs(kcm); release_sock(sk); } static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) { struct sock *sk = sock->sk; struct kcm_sock *kcm = kcm_sk(sk); int err = 0; struct strp_msg *stm; int copied = 0; struct sk_buff *skb; skb = skb_recv_datagram(sk, flags, &err); if (!skb) goto out; /* Okay, have a message on the receive queue */ stm = strp_msg(skb); if (len > stm->full_len) len = stm->full_len; err = skb_copy_datagram_msg(skb, stm->offset, msg, len); if (err < 0) goto out; copied = len; if (likely(!(flags & MSG_PEEK))) { KCM_STATS_ADD(kcm->stats.rx_bytes, copied); if (copied < stm->full_len) { if (sock->type == SOCK_DGRAM) { /* Truncated message */ msg->msg_flags |= MSG_TRUNC; goto msg_finished; } stm->offset += copied; stm->full_len -= copied; } else { msg_finished: /* Finished with message */ msg->msg_flags |= MSG_EOR; KCM_STATS_INCR(kcm->stats.rx_msgs); } } out: skb_free_datagram(sk, skb); return copied ? : err; } static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { struct sock *sk = sock->sk; struct kcm_sock *kcm = kcm_sk(sk); struct strp_msg *stm; int err = 0; ssize_t copied; struct sk_buff *skb; /* Only support splice for SOCKSEQPACKET */ skb = skb_recv_datagram(sk, flags, &err); if (!skb) goto err_out; /* Okay, have a message on the receive queue */ stm = strp_msg(skb); if (len > stm->full_len) len = stm->full_len; copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags); if (copied < 0) { err = copied; goto err_out; } KCM_STATS_ADD(kcm->stats.rx_bytes, copied); stm->offset += copied; stm->full_len -= copied; /* We have no way to return MSG_EOR. If all the bytes have been * read we still leave the message in the receive socket buffer. * A subsequent recvmsg needs to be done to return MSG_EOR and * finish reading the message. */ skb_free_datagram(sk, skb); return copied; err_out: skb_free_datagram(sk, skb); return err; } /* kcm sock lock held */ static void kcm_recv_disable(struct kcm_sock *kcm) { struct kcm_mux *mux = kcm->mux; if (kcm->rx_disabled) return; spin_lock_bh(&mux->rx_lock); kcm->rx_disabled = 1; /* If a psock is reserved we'll do cleanup in unreserve */ if (!kcm->rx_psock) { if (kcm->rx_wait) { list_del(&kcm->wait_rx_list); /* paired with lockless reads in kcm_rfree() */ WRITE_ONCE(kcm->rx_wait, false); } requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); } spin_unlock_bh(&mux->rx_lock); } /* kcm sock lock held */ static void kcm_recv_enable(struct kcm_sock *kcm) { struct kcm_mux *mux = kcm->mux; if (!kcm->rx_disabled) return; spin_lock_bh(&mux->rx_lock); kcm->rx_disabled = 0; kcm_rcv_ready(kcm); spin_unlock_bh(&mux->rx_lock); } static int kcm_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, unsigned int optlen) { struct kcm_sock *kcm = kcm_sk(sock->sk); int val, valbool; int err = 0; if (level != SOL_KCM) return -ENOPROTOOPT; if (optlen < sizeof(int)) return -EINVAL; if (copy_from_sockptr(&val, optval, sizeof(int))) return -EFAULT; valbool = val ? 1 : 0; switch (optname) { case KCM_RECV_DISABLE: lock_sock(&kcm->sk); if (valbool) kcm_recv_disable(kcm); else kcm_recv_enable(kcm); release_sock(&kcm->sk); break; default: err = -ENOPROTOOPT; } return err; } static int kcm_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { struct kcm_sock *kcm = kcm_sk(sock->sk); int val, len; if (level != SOL_KCM) return -ENOPROTOOPT; if (get_user(len, optlen)) return -EFAULT; if (len < 0) return -EINVAL; len = min_t(unsigned int, len, sizeof(int)); switch (optname) { case KCM_RECV_DISABLE: val = kcm->rx_disabled; break; default: return -ENOPROTOOPT; } if (put_user(len, optlen)) return -EFAULT; if (copy_to_user(optval, &val, len)) return -EFAULT; return 0; } static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux) { struct kcm_sock *tkcm; struct list_head *head; int index = 0; /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so * we set sk_state, otherwise epoll_wait always returns right away with * EPOLLHUP */ kcm->sk.sk_state = TCP_ESTABLISHED; /* Add to mux's kcm sockets list */ kcm->mux = mux; spin_lock_bh(&mux->lock); head = &mux->kcm_socks; list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) { if (tkcm->index != index) break; head = &tkcm->kcm_sock_list; index++; } list_add(&kcm->kcm_sock_list, head); kcm->index = index; mux->kcm_socks_cnt++; spin_unlock_bh(&mux->lock); INIT_WORK(&kcm->tx_work, kcm_tx_work); spin_lock_bh(&mux->rx_lock); kcm_rcv_ready(kcm); spin_unlock_bh(&mux->rx_lock); } static int kcm_attach(struct socket *sock, struct socket *csock, struct bpf_prog *prog) { struct kcm_sock *kcm = kcm_sk(sock->sk); struct kcm_mux *mux = kcm->mux; struct sock *csk; struct kcm_psock *psock = NULL, *tpsock; struct list_head *head; int index = 0; static const struct strp_callbacks cb = { .rcv_msg = kcm_rcv_strparser, .parse_msg = kcm_parse_func_strparser, .read_sock_done = kcm_read_sock_done, }; int err = 0; csk = csock->sk; if (!csk) return -EINVAL; lock_sock(csk); /* Only allow TCP sockets to be attached for now */ if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || csk->sk_protocol != IPPROTO_TCP) { err = -EOPNOTSUPP; goto out; } /* Don't allow listeners or closed sockets */ if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) { err = -EOPNOTSUPP; goto out; } psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); if (!psock) { err = -ENOMEM; goto out; } psock->mux = mux; psock->sk = csk; psock->bpf_prog = prog; write_lock_bh(&csk->sk_callback_lock); /* Check if sk_user_data is already by KCM or someone else. * Must be done under lock to prevent race conditions. */ if (csk->sk_user_data) { write_unlock_bh(&csk->sk_callback_lock); kmem_cache_free(kcm_psockp, psock); err = -EALREADY; goto out; } err = strp_init(&psock->strp, csk, &cb); if (err) { write_unlock_bh(&csk->sk_callback_lock); kmem_cache_free(kcm_psockp, psock); goto out; } psock->save_data_ready = csk->sk_data_ready; psock->save_write_space = csk->sk_write_space; psock->save_state_change = csk->sk_state_change; csk->sk_user_data = psock; csk->sk_data_ready = psock_data_ready; csk->sk_write_space = psock_write_space; csk->sk_state_change = psock_state_change; write_unlock_bh(&csk->sk_callback_lock); sock_hold(csk); /* Finished initialization, now add the psock to the MUX. */ spin_lock_bh(&mux->lock); head = &mux->psocks; list_for_each_entry(tpsock, &mux->psocks, psock_list) { if (tpsock->index != index) break; head = &tpsock->psock_list; index++; } list_add(&psock->psock_list, head); psock->index = index; KCM_STATS_INCR(mux->stats.psock_attach); mux->psocks_cnt++; psock_now_avail(psock); spin_unlock_bh(&mux->lock); /* Schedule RX work in case there are already bytes queued */ strp_check_rcv(&psock->strp); out: release_sock(csk); return err; } static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info) { struct socket *csock; struct bpf_prog *prog; int err; csock = sockfd_lookup(info->fd, &err); if (!csock) return -ENOENT; prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER); if (IS_ERR(prog)) { err = PTR_ERR(prog); goto out; } err = kcm_attach(sock, csock, prog); if (err) { bpf_prog_put(prog); goto out; } /* Keep reference on file also */ return 0; out: sockfd_put(csock); return err; } static void kcm_unattach(struct kcm_psock *psock) { struct sock *csk = psock->sk; struct kcm_mux *mux = psock->mux; lock_sock(csk); /* Stop getting callbacks from TCP socket. After this there should * be no way to reserve a kcm for this psock. */ write_lock_bh(&csk->sk_callback_lock); csk->sk_user_data = NULL; csk->sk_data_ready = psock->save_data_ready; csk->sk_write_space = psock->save_write_space; csk->sk_state_change = psock->save_state_change; strp_stop(&psock->strp); if (WARN_ON(psock->rx_kcm)) { write_unlock_bh(&csk->sk_callback_lock); release_sock(csk); return; } spin_lock_bh(&mux->rx_lock); /* Stop receiver activities. After this point psock should not be * able to get onto ready list either through callbacks or work. */ if (psock->ready_rx_msg) { list_del(&psock->psock_ready_list); kfree_skb(psock->ready_rx_msg); psock->ready_rx_msg = NULL; KCM_STATS_INCR(mux->stats.rx_ready_drops); } spin_unlock_bh(&mux->rx_lock); write_unlock_bh(&csk->sk_callback_lock); /* Call strp_done without sock lock */ release_sock(csk); strp_done(&psock->strp); lock_sock(csk); bpf_prog_put(psock->bpf_prog); spin_lock_bh(&mux->lock); aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats); save_strp_stats(&psock->strp, &mux->aggregate_strp_stats); KCM_STATS_INCR(mux->stats.psock_unattach); if (psock->tx_kcm) { /* psock was reserved. Just mark it finished and we will clean * up in the kcm paths, we need kcm lock which can not be * acquired here. */ KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); spin_unlock_bh(&mux->lock); /* We are unattaching a socket that is reserved. Abort the * socket since we may be out of sync in sending on it. We need * to do this without the mux lock. */ kcm_abort_tx_psock(psock, EPIPE, false); spin_lock_bh(&mux->lock); if (!psock->tx_kcm) { /* psock now unreserved in window mux was unlocked */ goto no_reserved; } psock->done = 1; /* Commit done before queuing work to process it */ smp_mb(); /* Queue tx work to make sure psock->done is handled */ queue_work(kcm_wq, &psock->tx_kcm->tx_work); spin_unlock_bh(&mux->lock); } else { no_reserved: if (!psock->tx_stopped) list_del(&psock->psock_avail_list); list_del(&psock->psock_list); mux->psocks_cnt--; spin_unlock_bh(&mux->lock); sock_put(csk); fput(csk->sk_socket->file); kmem_cache_free(kcm_psockp, psock); } release_sock(csk); } static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) { struct kcm_sock *kcm = kcm_sk(sock->sk); struct kcm_mux *mux = kcm->mux; struct kcm_psock *psock; struct socket *csock; struct sock *csk; int err; csock = sockfd_lookup(info->fd, &err); if (!csock) return -ENOENT; csk = csock->sk; if (!csk) { err = -EINVAL; goto out; } err = -ENOENT; spin_lock_bh(&mux->lock); list_for_each_entry(psock, &mux->psocks, psock_list) { if (psock->sk != csk) continue; /* Found the matching psock */ if (psock->unattaching || WARN_ON(psock->done)) { err = -EALREADY; break; } psock->unattaching = 1; spin_unlock_bh(&mux->lock); /* Lower socket lock should already be held */ kcm_unattach(psock); err = 0; goto out; } spin_unlock_bh(&mux->lock); out: sockfd_put(csock); return err; } static struct proto kcm_proto = { .name = "KCM", .owner = THIS_MODULE, .obj_size = sizeof(struct kcm_sock), }; /* Clone a kcm socket. */ static struct file *kcm_clone(struct socket *osock) { struct socket *newsock; struct sock *newsk; newsock = sock_alloc(); if (!newsock) return ERR_PTR(-ENFILE); newsock->type = osock->type; newsock->ops = osock->ops; __module_get(newsock->ops->owner); newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, &kcm_proto, false); if (!newsk) { sock_release(newsock); return ERR_PTR(-ENOMEM); } sock_init_data(newsock, newsk); init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); } static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { int err; switch (cmd) { case SIOCKCMATTACH: { struct kcm_attach info; if (copy_from_user(&info, (void __user *)arg, sizeof(info))) return -EFAULT; err = kcm_attach_ioctl(sock, &info); break; } case SIOCKCMUNATTACH: { struct kcm_unattach info; if (copy_from_user(&info, (void __user *)arg, sizeof(info))) return -EFAULT; err = kcm_unattach_ioctl(sock, &info); break; } case SIOCKCMCLONE: { struct kcm_clone info; struct file *file; info.fd = get_unused_fd_flags(0); if (unlikely(info.fd < 0)) return info.fd; file = kcm_clone(sock); if (IS_ERR(file)) { put_unused_fd(info.fd); return PTR_ERR(file); } if (copy_to_user((void __user *)arg, &info, sizeof(info))) { put_unused_fd(info.fd); fput(file); return -EFAULT; } fd_install(info.fd, file); err = 0; break; } default: err = -ENOIOCTLCMD; break; } return err; } static void free_mux(struct rcu_head *rcu) { struct kcm_mux *mux = container_of(rcu, struct kcm_mux, rcu); kmem_cache_free(kcm_muxp, mux); } static void release_mux(struct kcm_mux *mux) { struct kcm_net *knet = mux->knet; struct kcm_psock *psock, *tmp_psock; /* Release psocks */ list_for_each_entry_safe(psock, tmp_psock, &mux->psocks, psock_list) { if (!WARN_ON(psock->unattaching)) kcm_unattach(psock); } if (WARN_ON(mux->psocks_cnt)) return; __skb_queue_purge(&mux->rx_hold_queue); mutex_lock(&knet->mutex); aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats); aggregate_psock_stats(&mux->aggregate_psock_stats, &knet->aggregate_psock_stats); aggregate_strp_stats(&mux->aggregate_strp_stats, &knet->aggregate_strp_stats); list_del_rcu(&mux->kcm_mux_list); knet->count--; mutex_unlock(&knet->mutex); call_rcu(&mux->rcu, free_mux); } static void kcm_done(struct kcm_sock *kcm) { struct kcm_mux *mux = kcm->mux; struct sock *sk = &kcm->sk; int socks_cnt; spin_lock_bh(&mux->rx_lock); if (kcm->rx_psock) { /* Cleanup in unreserve_rx_kcm */ WARN_ON(kcm->done); kcm->rx_disabled = 1; kcm->done = 1; spin_unlock_bh(&mux->rx_lock); return; } if (kcm->rx_wait) { list_del(&kcm->wait_rx_list); /* paired with lockless reads in kcm_rfree() */ WRITE_ONCE(kcm->rx_wait, false); } /* Move any pending receive messages to other kcm sockets */ requeue_rx_msgs(mux, &sk->sk_receive_queue); spin_unlock_bh(&mux->rx_lock); if (WARN_ON(sk_rmem_alloc_get(sk))) return; /* Detach from MUX */ spin_lock_bh(&mux->lock); list_del(&kcm->kcm_sock_list); mux->kcm_socks_cnt--; socks_cnt = mux->kcm_socks_cnt; spin_unlock_bh(&mux->lock); if (!socks_cnt) { /* We are done with the mux now. */ release_mux(mux); } WARN_ON(kcm->rx_wait); sock_put(&kcm->sk); } /* Called by kcm_release to close a KCM socket. * If this is the last KCM socket on the MUX, destroy the MUX. */ static int kcm_release(struct socket *sock) { struct sock *sk = sock->sk; struct kcm_sock *kcm; struct kcm_mux *mux; struct kcm_psock *psock; if (!sk) return 0; kcm = kcm_sk(sk); mux = kcm->mux; lock_sock(sk); sock_orphan(sk); kfree_skb(kcm->seq_skb); /* Purge queue under lock to avoid race condition with tx_work trying * to act when queue is nonempty. If tx_work runs after this point * it will just return. */ __skb_queue_purge(&sk->sk_write_queue); /* Set tx_stopped. This is checked when psock is bound to a kcm and we * get a writespace callback. This prevents further work being queued * from the callback (unbinding the psock occurs after canceling work. */ kcm->tx_stopped = 1; release_sock(sk); spin_lock_bh(&mux->lock); if (kcm->tx_wait) { /* Take of tx_wait list, after this point there should be no way * that a psock will be assigned to this kcm. */ list_del(&kcm->wait_psock_list); kcm->tx_wait = false; } spin_unlock_bh(&mux->lock); /* Cancel work. After this point there should be no outside references * to the kcm socket. */ cancel_work_sync(&kcm->tx_work); lock_sock(sk); psock = kcm->tx_psock; if (psock) { /* A psock was reserved, so we need to kill it since it * may already have some bytes queued from a message. We * need to do this after removing kcm from tx_wait list. */ kcm_abort_tx_psock(psock, EPIPE, false); unreserve_psock(kcm); } release_sock(sk); WARN_ON(kcm->tx_wait); WARN_ON(kcm->tx_psock); sock->sk = NULL; kcm_done(kcm); return 0; } static const struct proto_ops kcm_dgram_ops = { .family = PF_KCM, .owner = THIS_MODULE, .release = kcm_release, .bind = sock_no_bind, .connect = sock_no_connect, .socketpair = sock_no_socketpair, .accept = sock_no_accept, .getname = sock_no_getname, .poll = datagram_poll, .ioctl = kcm_ioctl, .listen = sock_no_listen, .shutdown = sock_no_shutdown, .setsockopt = kcm_setsockopt, .getsockopt = kcm_getsockopt, .sendmsg = kcm_sendmsg, .recvmsg = kcm_recvmsg, .mmap = sock_no_mmap, .splice_eof = kcm_splice_eof, }; static const struct proto_ops kcm_seqpacket_ops = { .family = PF_KCM, .owner = THIS_MODULE, .release = kcm_release, .bind = sock_no_bind, .connect = sock_no_connect, .socketpair = sock_no_socketpair, .accept = sock_no_accept, .getname = sock_no_getname, .poll = datagram_poll, .ioctl = kcm_ioctl, .listen = sock_no_listen, .shutdown = sock_no_shutdown, .setsockopt = kcm_setsockopt, .getsockopt = kcm_getsockopt, .sendmsg = kcm_sendmsg, .recvmsg = kcm_recvmsg, .mmap = sock_no_mmap, .splice_eof = kcm_splice_eof, .splice_read = kcm_splice_read, }; /* Create proto operation for kcm sockets */ static int kcm_create(struct net *net, struct socket *sock, int protocol, int kern) { struct kcm_net *knet = net_generic(net, kcm_net_id); struct sock *sk; struct kcm_mux *mux; switch (sock->type) { case SOCK_DGRAM: sock->ops = &kcm_dgram_ops; break; case SOCK_SEQPACKET: sock->ops = &kcm_seqpacket_ops; break; default: return -ESOCKTNOSUPPORT; } if (protocol != KCMPROTO_CONNECTED) return -EPROTONOSUPPORT; sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern); if (!sk) return -ENOMEM; /* Allocate a kcm mux, shared between KCM sockets */ mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL); if (!mux) { sk_free(sk); return -ENOMEM; } spin_lock_init(&mux->lock); spin_lock_init(&mux->rx_lock); INIT_LIST_HEAD(&mux->kcm_socks); INIT_LIST_HEAD(&mux->kcm_rx_waiters); INIT_LIST_HEAD(&mux->kcm_tx_waiters); INIT_LIST_HEAD(&mux->psocks); INIT_LIST_HEAD(&mux->psocks_ready); INIT_LIST_HEAD(&mux->psocks_avail); mux->knet = knet; /* Add new MUX to list */ mutex_lock(&knet->mutex); list_add_rcu(&mux->kcm_mux_list, &knet->mux_list); knet->count++; mutex_unlock(&knet->mutex); skb_queue_head_init(&mux->rx_hold_queue); /* Init KCM socket */ sock_init_data(sock, sk); init_kcm_sock(kcm_sk(sk), mux); return 0; } static const struct net_proto_family kcm_family_ops = { .family = PF_KCM, .create = kcm_create, .owner = THIS_MODULE, }; static __net_init int kcm_init_net(struct net *net) { struct kcm_net *knet = net_generic(net, kcm_net_id); INIT_LIST_HEAD_RCU(&knet->mux_list); mutex_init(&knet->mutex); return 0; } static __net_exit void kcm_exit_net(struct net *net) { struct kcm_net *knet = net_generic(net, kcm_net_id); /* All KCM sockets should be closed at this point, which should mean * that all multiplexors and psocks have been destroyed. */ WARN_ON(!list_empty(&knet->mux_list)); mutex_destroy(&knet->mutex); } static struct pernet_operations kcm_net_ops = { .init = kcm_init_net, .exit = kcm_exit_net, .id = &kcm_net_id, .size = sizeof(struct kcm_net), }; static int __init kcm_init(void) { int err = -ENOMEM; kcm_muxp = KMEM_CACHE(kcm_mux, SLAB_HWCACHE_ALIGN); if (!kcm_muxp) goto fail; kcm_psockp = KMEM_CACHE(kcm_psock, SLAB_HWCACHE_ALIGN); if (!kcm_psockp) goto fail; kcm_wq = create_singlethread_workqueue("kkcmd"); if (!kcm_wq) goto fail; err = proto_register(&kcm_proto, 1); if (err) goto fail; err = register_pernet_device(&kcm_net_ops); if (err) goto net_ops_fail; err = sock_register(&kcm_family_ops); if (err) goto sock_register_fail; err = kcm_proc_init(); if (err) goto proc_init_fail; return 0; proc_init_fail: sock_unregister(PF_KCM); sock_register_fail: unregister_pernet_device(&kcm_net_ops); net_ops_fail: proto_unregister(&kcm_proto); fail: kmem_cache_destroy(kcm_muxp); kmem_cache_destroy(kcm_psockp); if (kcm_wq) destroy_workqueue(kcm_wq); return err; } static void __exit kcm_exit(void) { kcm_proc_exit(); sock_unregister(PF_KCM); unregister_pernet_device(&kcm_net_ops); proto_unregister(&kcm_proto); destroy_workqueue(kcm_wq); kmem_cache_destroy(kcm_muxp); kmem_cache_destroy(kcm_psockp); } module_init(kcm_init); module_exit(kcm_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("KCM (Kernel Connection Multiplexor) sockets"); MODULE_ALIAS_NETPROTO(PF_KCM);
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with Cregit http://github.com/cregit/cregit
Version 2.0-RC1