| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ |
| |
| #include <linux/skmsg.h> |
| #include <linux/skbuff.h> |
| #include <linux/scatterlist.h> |
| |
| #include <net/sock.h> |
| #include <net/tcp.h> |
| #include <net/tls.h> |
| |
| static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce) |
| { |
| if (msg->sg.end > msg->sg.start && |
| elem_first_coalesce < msg->sg.end) |
| return true; |
| |
| if (msg->sg.end < msg->sg.start && |
| (elem_first_coalesce > msg->sg.start || |
| elem_first_coalesce < msg->sg.end)) |
| return true; |
| |
| return false; |
| } |
| |
| int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, |
| int elem_first_coalesce) |
| { |
| struct page_frag *pfrag = sk_page_frag(sk); |
| int ret = 0; |
| |
| len -= msg->sg.size; |
| while (len > 0) { |
| struct scatterlist *sge; |
| u32 orig_offset; |
| int use, i; |
| |
| if (!sk_page_frag_refill(sk, pfrag)) |
| return -ENOMEM; |
| |
| orig_offset = pfrag->offset; |
| use = min_t(int, len, pfrag->size - orig_offset); |
| if (!sk_wmem_schedule(sk, use)) |
| return -ENOMEM; |
| |
| i = msg->sg.end; |
| sk_msg_iter_var_prev(i); |
| sge = &msg->sg.data[i]; |
| |
| if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) && |
| sg_page(sge) == pfrag->page && |
| sge->offset + sge->length == orig_offset) { |
| sge->length += use; |
| } else { |
| if (sk_msg_full(msg)) { |
| ret = -ENOSPC; |
| break; |
| } |
| |
| sge = &msg->sg.data[msg->sg.end]; |
| sg_unmark_end(sge); |
| sg_set_page(sge, pfrag->page, use, orig_offset); |
| get_page(pfrag->page); |
| sk_msg_iter_next(msg, end); |
| } |
| |
| sk_mem_charge(sk, use); |
| msg->sg.size += use; |
| pfrag->offset += use; |
| len -= use; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_alloc); |
| |
| int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src, |
| u32 off, u32 len) |
| { |
| int i = src->sg.start; |
| struct scatterlist *sge = sk_msg_elem(src, i); |
| struct scatterlist *sgd = NULL; |
| u32 sge_len, sge_off; |
| |
| while (off) { |
| if (sge->length > off) |
| break; |
| off -= sge->length; |
| sk_msg_iter_var_next(i); |
| if (i == src->sg.end && off) |
| return -ENOSPC; |
| sge = sk_msg_elem(src, i); |
| } |
| |
| while (len) { |
| sge_len = sge->length - off; |
| if (sge_len > len) |
| sge_len = len; |
| |
| if (dst->sg.end) |
| sgd = sk_msg_elem(dst, dst->sg.end - 1); |
| |
| if (sgd && |
| (sg_page(sge) == sg_page(sgd)) && |
| (sg_virt(sge) + off == sg_virt(sgd) + sgd->length)) { |
| sgd->length += sge_len; |
| dst->sg.size += sge_len; |
| } else if (!sk_msg_full(dst)) { |
| sge_off = sge->offset + off; |
| sk_msg_page_add(dst, sg_page(sge), sge_len, sge_off); |
| } else { |
| return -ENOSPC; |
| } |
| |
| off = 0; |
| len -= sge_len; |
| sk_mem_charge(sk, sge_len); |
| sk_msg_iter_var_next(i); |
| if (i == src->sg.end && len) |
| return -ENOSPC; |
| sge = sk_msg_elem(src, i); |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_clone); |
| |
| void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes) |
| { |
| int i = msg->sg.start; |
| |
| do { |
| struct scatterlist *sge = sk_msg_elem(msg, i); |
| |
| if (bytes < sge->length) { |
| sge->length -= bytes; |
| sge->offset += bytes; |
| sk_mem_uncharge(sk, bytes); |
| break; |
| } |
| |
| sk_mem_uncharge(sk, sge->length); |
| bytes -= sge->length; |
| sge->length = 0; |
| sge->offset = 0; |
| sk_msg_iter_var_next(i); |
| } while (bytes && i != msg->sg.end); |
| msg->sg.start = i; |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_return_zero); |
| |
| void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes) |
| { |
| int i = msg->sg.start; |
| |
| do { |
| struct scatterlist *sge = &msg->sg.data[i]; |
| int uncharge = (bytes < sge->length) ? bytes : sge->length; |
| |
| sk_mem_uncharge(sk, uncharge); |
| bytes -= uncharge; |
| sk_msg_iter_var_next(i); |
| } while (i != msg->sg.end); |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_return); |
| |
| static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i, |
| bool charge) |
| { |
| struct scatterlist *sge = sk_msg_elem(msg, i); |
| u32 len = sge->length; |
| |
| /* When the skb owns the memory we free it from consume_skb path. */ |
| if (!msg->skb) { |
| if (charge) |
| sk_mem_uncharge(sk, len); |
| put_page(sg_page(sge)); |
| } |
| memset(sge, 0, sizeof(*sge)); |
| return len; |
| } |
| |
| static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i, |
| bool charge) |
| { |
| struct scatterlist *sge = sk_msg_elem(msg, i); |
| int freed = 0; |
| |
| while (msg->sg.size) { |
| msg->sg.size -= sge->length; |
| freed += sk_msg_free_elem(sk, msg, i, charge); |
| sk_msg_iter_var_next(i); |
| sk_msg_check_to_free(msg, i, msg->sg.size); |
| sge = sk_msg_elem(msg, i); |
| } |
| consume_skb(msg->skb); |
| sk_msg_init(msg); |
| return freed; |
| } |
| |
| int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg) |
| { |
| return __sk_msg_free(sk, msg, msg->sg.start, false); |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_free_nocharge); |
| |
| int sk_msg_free(struct sock *sk, struct sk_msg *msg) |
| { |
| return __sk_msg_free(sk, msg, msg->sg.start, true); |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_free); |
| |
| static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, |
| u32 bytes, bool charge) |
| { |
| struct scatterlist *sge; |
| u32 i = msg->sg.start; |
| |
| while (bytes) { |
| sge = sk_msg_elem(msg, i); |
| if (!sge->length) |
| break; |
| if (bytes < sge->length) { |
| if (charge) |
| sk_mem_uncharge(sk, bytes); |
| sge->length -= bytes; |
| sge->offset += bytes; |
| msg->sg.size -= bytes; |
| break; |
| } |
| |
| msg->sg.size -= sge->length; |
| bytes -= sge->length; |
| sk_msg_free_elem(sk, msg, i, charge); |
| sk_msg_iter_var_next(i); |
| sk_msg_check_to_free(msg, i, bytes); |
| } |
| msg->sg.start = i; |
| } |
| |
| void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes) |
| { |
| __sk_msg_free_partial(sk, msg, bytes, true); |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_free_partial); |
| |
| void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg, |
| u32 bytes) |
| { |
| __sk_msg_free_partial(sk, msg, bytes, false); |
| } |
| |
| void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len) |
| { |
| int trim = msg->sg.size - len; |
| u32 i = msg->sg.end; |
| |
| if (trim <= 0) { |
| WARN_ON(trim < 0); |
| return; |
| } |
| |
| sk_msg_iter_var_prev(i); |
| msg->sg.size = len; |
| while (msg->sg.data[i].length && |
| trim >= msg->sg.data[i].length) { |
| trim -= msg->sg.data[i].length; |
| sk_msg_free_elem(sk, msg, i, true); |
| sk_msg_iter_var_prev(i); |
| if (!trim) |
| goto out; |
| } |
| |
| msg->sg.data[i].length -= trim; |
| sk_mem_uncharge(sk, trim); |
| /* Adjust copybreak if it falls into the trimmed part of last buf */ |
| if (msg->sg.curr == i && msg->sg.copybreak > msg->sg.data[i].length) |
| msg->sg.copybreak = msg->sg.data[i].length; |
| out: |
| sk_msg_iter_var_next(i); |
| msg->sg.end = i; |
| |
| /* If we trim data a full sg elem before curr pointer update |
| * copybreak and current so that any future copy operations |
| * start at new copy location. |
| * However trimed data that has not yet been used in a copy op |
| * does not require an update. |
| */ |
| if (!msg->sg.size) { |
| msg->sg.curr = msg->sg.start; |
| msg->sg.copybreak = 0; |
| } else if (sk_msg_iter_dist(msg->sg.start, msg->sg.curr) >= |
| sk_msg_iter_dist(msg->sg.start, msg->sg.end)) { |
| sk_msg_iter_var_prev(i); |
| msg->sg.curr = i; |
| msg->sg.copybreak = msg->sg.data[i].length; |
| } |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_trim); |
| |
| int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from, |
| struct sk_msg *msg, u32 bytes) |
| { |
| int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg); |
| const int to_max_pages = MAX_MSG_FRAGS; |
| struct page *pages[MAX_MSG_FRAGS]; |
| ssize_t orig, copied, use, offset; |
| |
| orig = msg->sg.size; |
| while (bytes > 0) { |
| i = 0; |
| maxpages = to_max_pages - num_elems; |
| if (maxpages == 0) { |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| copied = iov_iter_get_pages(from, pages, bytes, maxpages, |
| &offset); |
| if (copied <= 0) { |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| iov_iter_advance(from, copied); |
| bytes -= copied; |
| msg->sg.size += copied; |
| |
| while (copied) { |
| use = min_t(int, copied, PAGE_SIZE - offset); |
| sg_set_page(&msg->sg.data[msg->sg.end], |
| pages[i], use, offset); |
| sg_unmark_end(&msg->sg.data[msg->sg.end]); |
| sk_mem_charge(sk, use); |
| |
| offset = 0; |
| copied -= use; |
| sk_msg_iter_next(msg, end); |
| num_elems++; |
| i++; |
| } |
| /* When zerocopy is mixed with sk_msg_*copy* operations we |
| * may have a copybreak set in this case clear and prefer |
| * zerocopy remainder when possible. |
| */ |
| msg->sg.copybreak = 0; |
| msg->sg.curr = msg->sg.end; |
| } |
| out: |
| /* Revert iov_iter updates, msg will need to use 'trim' later if it |
| * also needs to be cleared. |
| */ |
| if (ret) |
| iov_iter_revert(from, msg->sg.size - orig); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter); |
| |
| int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from, |
| struct sk_msg *msg, u32 bytes) |
| { |
| int ret = -ENOSPC, i = msg->sg.curr; |
| struct scatterlist *sge; |
| u32 copy, buf_size; |
| void *to; |
| |
| do { |
| sge = sk_msg_elem(msg, i); |
| /* This is possible if a trim operation shrunk the buffer */ |
| if (msg->sg.copybreak >= sge->length) { |
| msg->sg.copybreak = 0; |
| sk_msg_iter_var_next(i); |
| if (i == msg->sg.end) |
| break; |
| sge = sk_msg_elem(msg, i); |
| } |
| |
| buf_size = sge->length - msg->sg.copybreak; |
| copy = (buf_size > bytes) ? bytes : buf_size; |
| to = sg_virt(sge) + msg->sg.copybreak; |
| msg->sg.copybreak += copy; |
| if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) |
| ret = copy_from_iter_nocache(to, copy, from); |
| else |
| ret = copy_from_iter(to, copy, from); |
| if (ret != copy) { |
| ret = -EFAULT; |
| goto out; |
| } |
| bytes -= copy; |
| if (!bytes) |
| break; |
| msg->sg.copybreak = 0; |
| sk_msg_iter_var_next(i); |
| } while (i != msg->sg.end); |
| out: |
| msg->sg.curr = i; |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter); |
| |
| /* Receive sk_msg from psock->ingress_msg to @msg. */ |
| int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, |
| int len, int flags) |
| { |
| struct iov_iter *iter = &msg->msg_iter; |
| int peek = flags & MSG_PEEK; |
| struct sk_msg *msg_rx; |
| int i, copied = 0; |
| |
| msg_rx = sk_psock_peek_msg(psock); |
| while (copied != len) { |
| struct scatterlist *sge; |
| |
| if (unlikely(!msg_rx)) |
| break; |
| |
| i = msg_rx->sg.start; |
| do { |
| struct page *page; |
| int copy; |
| |
| sge = sk_msg_elem(msg_rx, i); |
| copy = sge->length; |
| page = sg_page(sge); |
| if (copied + copy > len) |
| copy = len - copied; |
| copy = copy_page_to_iter(page, sge->offset, copy, iter); |
| if (!copy) |
| return copied ? copied : -EFAULT; |
| |
| copied += copy; |
| if (likely(!peek)) { |
| sge->offset += copy; |
| sge->length -= copy; |
| if (!msg_rx->skb) |
| sk_mem_uncharge(sk, copy); |
| msg_rx->sg.size -= copy; |
| |
| if (!sge->length) { |
| sk_msg_iter_var_next(i); |
| if (!msg_rx->skb) |
| put_page(page); |
| } |
| } else { |
| /* Lets not optimize peek case if copy_page_to_iter |
| * didn't copy the entire length lets just break. |
| */ |
| if (copy != sge->length) |
| return copied; |
| sk_msg_iter_var_next(i); |
| } |
| |
| if (copied == len) |
| break; |
| } while (i != msg_rx->sg.end); |
| |
| if (unlikely(peek)) { |
| msg_rx = sk_psock_next_msg(psock, msg_rx); |
| if (!msg_rx) |
| break; |
| continue; |
| } |
| |
| msg_rx->sg.start = i; |
| if (!sge->length && msg_rx->sg.start == msg_rx->sg.end) { |
| msg_rx = sk_psock_dequeue_msg(psock); |
| kfree_sk_msg(msg_rx); |
| } |
| msg_rx = sk_psock_peek_msg(psock); |
| } |
| |
| return copied; |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_recvmsg); |
| |
| bool sk_msg_is_readable(struct sock *sk) |
| { |
| struct sk_psock *psock; |
| bool empty = true; |
| |
| rcu_read_lock(); |
| psock = sk_psock(sk); |
| if (likely(psock)) |
| empty = list_empty(&psock->ingress_msg); |
| rcu_read_unlock(); |
| return !empty; |
| } |
| EXPORT_SYMBOL_GPL(sk_msg_is_readable); |
| |
| static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk, |
| struct sk_buff *skb) |
| { |
| struct sk_msg *msg; |
| |
| if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) |
| return NULL; |
| |
| if (!sk_rmem_schedule(sk, skb, skb->truesize)) |
| return NULL; |
| |
| msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_KERNEL); |
| if (unlikely(!msg)) |
| return NULL; |
| |
| sk_msg_init(msg); |
| return msg; |
| } |
| |
| static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb, |
| struct sk_psock *psock, |
| struct sock *sk, |
| struct sk_msg *msg) |
| { |
| int num_sge, copied; |
| |
| /* skb linearize may fail with ENOMEM, but lets simply try again |
| * later if this happens. Under memory pressure we don't want to |
| * drop the skb. We need to linearize the skb so that the mapping |
| * in skb_to_sgvec can not error. |
| */ |
| if (skb_linearize(skb)) |
| return -EAGAIN; |
| num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len); |
| if (unlikely(num_sge < 0)) |
| return num_sge; |
| |
| copied = skb->len; |
| msg->sg.start = 0; |
| msg->sg.size = copied; |
| msg->sg.end = num_sge; |
| msg->skb = skb; |
| |
| sk_psock_queue_msg(psock, msg); |
| sk_psock_data_ready(sk, psock); |
| return copied; |
| } |
| |
| static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb); |
| |
| static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) |
| { |
| struct sock *sk = psock->sk; |
| struct sk_msg *msg; |
| int err; |
| |
| /* If we are receiving on the same sock skb->sk is already assigned, |
| * skip memory accounting and owner transition seeing it already set |
| * correctly. |
| */ |
| if (unlikely(skb->sk == sk)) |
| return sk_psock_skb_ingress_self(psock, skb); |
| msg = sk_psock_create_ingress_msg(sk, skb); |
| if (!msg) |
| return -EAGAIN; |
| |
| /* This will transition ownership of the data from the socket where |
| * the BPF program was run initiating the redirect to the socket |
| * we will eventually receive this data on. The data will be released |
| * from skb_consume found in __tcp_bpf_recvmsg() after its been copied |
| * into user buffers. |
| */ |
| skb_set_owner_r(skb, sk); |
| err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg); |
| if (err < 0) |
| kfree(msg); |
| return err; |
| } |
| |
| /* Puts an skb on the ingress queue of the socket already assigned to the |
| * skb. In this case we do not need to check memory limits or skb_set_owner_r |
| * because the skb is already accounted for here. |
| */ |
| static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb) |
| { |
| struct sk_msg *msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC); |
| struct sock *sk = psock->sk; |
| int err; |
| |
| if (unlikely(!msg)) |
| return -EAGAIN; |
| sk_msg_init(msg); |
| skb_set_owner_r(skb, sk); |
| err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg); |
| if (err < 0) |
| kfree(msg); |
| return err; |
| } |
| |
| static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb, |
| u32 off, u32 len, bool ingress) |
| { |
| if (!ingress) { |
| if (!sock_writeable(psock->sk)) |
| return -EAGAIN; |
| return skb_send_sock(psock->sk, skb, off, len); |
| } |
| return sk_psock_skb_ingress(psock, skb); |
| } |
| |
| static void sk_psock_skb_state(struct sk_psock *psock, |
| struct sk_psock_work_state *state, |
| struct sk_buff *skb, |
| int len, int off) |
| { |
| spin_lock_bh(&psock->ingress_lock); |
| if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { |
| state->skb = skb; |
| state->len = len; |
| state->off = off; |
| } else { |
| sock_drop(psock->sk, skb); |
| } |
| spin_unlock_bh(&psock->ingress_lock); |
| } |
| |
| static void sk_psock_backlog(struct work_struct *work) |
| { |
| struct sk_psock *psock = container_of(work, struct sk_psock, work); |
| struct sk_psock_work_state *state = &psock->work_state; |
| struct sk_buff *skb = NULL; |
| bool ingress; |
| u32 len, off; |
| int ret; |
| |
| mutex_lock(&psock->work_mutex); |
| if (unlikely(state->skb)) { |
| spin_lock_bh(&psock->ingress_lock); |
| skb = state->skb; |
| len = state->len; |
| off = state->off; |
| state->skb = NULL; |
| spin_unlock_bh(&psock->ingress_lock); |
| } |
| if (skb) |
| goto start; |
| |
| while ((skb = skb_dequeue(&psock->ingress_skb))) { |
| len = skb->len; |
| off = 0; |
| start: |
| ingress = skb_bpf_ingress(skb); |
| skb_bpf_redirect_clear(skb); |
| do { |
| ret = -EIO; |
| if (!sock_flag(psock->sk, SOCK_DEAD)) |
| ret = sk_psock_handle_skb(psock, skb, off, |
| len, ingress); |
| if (ret <= 0) { |
| if (ret == -EAGAIN) { |
| sk_psock_skb_state(psock, state, skb, |
| len, off); |
| goto end; |
| } |
| /* Hard errors break pipe and stop xmit. */ |
| sk_psock_report_error(psock, ret ? -ret : EPIPE); |
| sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED); |
| sock_drop(psock->sk, skb); |
| goto end; |
| } |
| off += ret; |
| len -= ret; |
| } while (len); |
| |
| if (!ingress) |
| kfree_skb(skb); |
| } |
| end: |
| mutex_unlock(&psock->work_mutex); |
| } |
| |
| struct sk_psock *sk_psock_init(struct sock *sk, int node) |
| { |
| struct sk_psock *psock; |
| struct proto *prot; |
| |
| write_lock_bh(&sk->sk_callback_lock); |
| |
| if (sk->sk_user_data) { |
| psock = ERR_PTR(-EBUSY); |
| goto out; |
| } |
| |
| psock = kzalloc_node(sizeof(*psock), GFP_ATOMIC | __GFP_NOWARN, node); |
| if (!psock) { |
| psock = ERR_PTR(-ENOMEM); |
| goto out; |
| } |
| |
| prot = READ_ONCE(sk->sk_prot); |
| psock->sk = sk; |
| psock->eval = __SK_NONE; |
| psock->sk_proto = prot; |
| psock->saved_unhash = prot->unhash; |
| psock->saved_close = prot->close; |
| psock->saved_write_space = sk->sk_write_space; |
| |
| INIT_LIST_HEAD(&psock->link); |
| spin_lock_init(&psock->link_lock); |
| |
| INIT_WORK(&psock->work, sk_psock_backlog); |
| mutex_init(&psock->work_mutex); |
| INIT_LIST_HEAD(&psock->ingress_msg); |
| spin_lock_init(&psock->ingress_lock); |
| skb_queue_head_init(&psock->ingress_skb); |
| |
| sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED); |
| refcount_set(&psock->refcnt, 1); |
| |
| rcu_assign_sk_user_data_nocopy(sk, psock); |
| sock_hold(sk); |
| |
| out: |
| write_unlock_bh(&sk->sk_callback_lock); |
| return psock; |
| } |
| EXPORT_SYMBOL_GPL(sk_psock_init); |
| |
| struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock) |
| { |
| struct sk_psock_link *link; |
| |
| spin_lock_bh(&psock->link_lock); |
| link = list_first_entry_or_null(&psock->link, struct sk_psock_link, |
| list); |
| if (link) |
| list_del(&link->list); |
| spin_unlock_bh(&psock->link_lock); |
| return link; |
| } |
| |
| static void __sk_psock_purge_ingress_msg(struct sk_psock *psock) |
| { |
| struct sk_msg *msg, *tmp; |
| |
| list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) { |
| list_del(&msg->list); |
| sk_msg_free(psock->sk, msg); |
| kfree(msg); |
| } |
| } |
| |
| static void __sk_psock_zap_ingress(struct sk_psock *psock) |
| { |
| struct sk_buff *skb; |
| |
| while ((skb = skb_dequeue(&psock->ingress_skb)) != NULL) { |
| skb_bpf_redirect_clear(skb); |
| sock_drop(psock->sk, skb); |
| } |
| kfree_skb(psock->work_state.skb); |
| /* We null the skb here to ensure that calls to sk_psock_backlog |
| * do not pick up the free'd skb. |
| */ |
| psock->work_state.skb = NULL; |
| __sk_psock_purge_ingress_msg(psock); |
| } |
| |
| static void sk_psock_link_destroy(struct sk_psock *psock) |
| { |
| struct sk_psock_link *link, *tmp; |
| |
| list_for_each_entry_safe(link, tmp, &psock->link, list) { |
| list_del(&link->list); |
| sk_psock_free_link(link); |
| } |
| } |
| |
| void sk_psock_stop(struct sk_psock *psock, bool wait) |
| { |
| spin_lock_bh(&psock->ingress_lock); |
| sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED); |
| sk_psock_cork_free(psock); |
| __sk_psock_zap_ingress(psock); |
| spin_unlock_bh(&psock->ingress_lock); |
| |
| if (wait) |
| cancel_work_sync(&psock->work); |
| } |
| |
| static void sk_psock_done_strp(struct sk_psock *psock); |
| |
| static void sk_psock_destroy(struct work_struct *work) |
| { |
| struct sk_psock *psock = container_of(to_rcu_work(work), |
| struct sk_psock, rwork); |
| /* No sk_callback_lock since already detached. */ |
| |
| sk_psock_done_strp(psock); |
| |
| cancel_work_sync(&psock->work); |
| mutex_destroy(&psock->work_mutex); |
| |
| psock_progs_drop(&psock->progs); |
| |
| sk_psock_link_destroy(psock); |
| sk_psock_cork_free(psock); |
| |
| if (psock->sk_redir) |
| sock_put(psock->sk_redir); |
| sock_put(psock->sk); |
| kfree(psock); |
| } |
| |
| void sk_psock_drop(struct sock *sk, struct sk_psock *psock) |
| { |
| write_lock_bh(&sk->sk_callback_lock); |
| sk_psock_restore_proto(sk, psock); |
| rcu_assign_sk_user_data(sk, NULL); |
| if (psock->progs.stream_parser) |
| sk_psock_stop_strp(sk, psock); |
| else if (psock->progs.stream_verdict || psock->progs.skb_verdict) |
| sk_psock_stop_verdict(sk, psock); |
| write_unlock_bh(&sk->sk_callback_lock); |
| |
| sk_psock_stop(psock, false); |
| |
| INIT_RCU_WORK(&psock->rwork, sk_psock_destroy); |
| queue_rcu_work(system_wq, &psock->rwork); |
| } |
| EXPORT_SYMBOL_GPL(sk_psock_drop); |
| |
| static int sk_psock_map_verd(int verdict, bool redir) |
| { |
| switch (verdict) { |
| case SK_PASS: |
| return redir ? __SK_REDIRECT : __SK_PASS; |
| case SK_DROP: |
| default: |
| break; |
| } |
| |
| return __SK_DROP; |
| } |
| |
| int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock, |
| struct sk_msg *msg) |
| { |
| struct bpf_prog *prog; |
| int ret; |
| |
| rcu_read_lock(); |
| prog = READ_ONCE(psock->progs.msg_parser); |
| if (unlikely(!prog)) { |
| ret = __SK_PASS; |
| goto out; |
| } |
| |
| sk_msg_compute_data_pointers(msg); |
| msg->sk = sk; |
| ret = bpf_prog_run_pin_on_cpu(prog, msg); |
| ret = sk_psock_map_verd(ret, msg->sk_redir); |
| psock->apply_bytes = msg->apply_bytes; |
| if (ret == __SK_REDIRECT) { |
| if (psock->sk_redir) |
| sock_put(psock->sk_redir); |
| psock->sk_redir = msg->sk_redir; |
| if (!psock->sk_redir) { |
| ret = __SK_DROP; |
| goto out; |
| } |
| sock_hold(psock->sk_redir); |
| } |
| out: |
| rcu_read_unlock(); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(sk_psock_msg_verdict); |
| |
| static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb) |
| { |
| struct sk_psock *psock_other; |
| struct sock *sk_other; |
| |
| sk_other = skb_bpf_redirect_fetch(skb); |
| /* This error is a buggy BPF program, it returned a redirect |
| * return code, but then didn't set a redirect interface. |
| */ |
| if (unlikely(!sk_other)) { |
| sock_drop(from->sk, skb); |
| return -EIO; |
| } |
| psock_other = sk_psock(sk_other); |
| /* This error indicates the socket is being torn down or had another |
| * error that caused the pipe to break. We can't send a packet on |
| * a socket that is in this state so we drop the skb. |
| */ |
| if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) { |
| skb_bpf_redirect_clear(skb); |
| sock_drop(from->sk, skb); |
| return -EIO; |
| } |
| spin_lock_bh(&psock_other->ingress_lock); |
| if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) { |
| spin_unlock_bh(&psock_other->ingress_lock); |
| skb_bpf_redirect_clear(skb); |
| sock_drop(from->sk, skb); |
| return -EIO; |
| } |
| |
| skb_queue_tail(&psock_other->ingress_skb, skb); |
| schedule_work(&psock_other->work); |
| spin_unlock_bh(&psock_other->ingress_lock); |
| return 0; |
| } |
| |
| static void sk_psock_tls_verdict_apply(struct sk_buff *skb, |
| struct sk_psock *from, int verdict) |
| { |
| switch (verdict) { |
| case __SK_REDIRECT: |
| sk_psock_skb_redirect(from, skb); |
| break; |
| case __SK_PASS: |
| case __SK_DROP: |
| default: |
| break; |
| } |
| } |
| |
| int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb) |
| { |
| struct bpf_prog *prog; |
| int ret = __SK_PASS; |
| |
| rcu_read_lock(); |
| prog = READ_ONCE(psock->progs.stream_verdict); |
| if (likely(prog)) { |
| skb->sk = psock->sk; |
| skb_dst_drop(skb); |
| skb_bpf_redirect_clear(skb); |
| ret = bpf_prog_run_pin_on_cpu(prog, skb); |
| ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb)); |
| skb->sk = NULL; |
| } |
| sk_psock_tls_verdict_apply(skb, psock, ret); |
| rcu_read_unlock(); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(sk_psock_tls_strp_read); |
| |
| static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb, |
| int verdict) |
| { |
| struct sock *sk_other; |
| int err = 0; |
| |
| switch (verdict) { |
| case __SK_PASS: |
| err = -EIO; |
| sk_other = psock->sk; |
| if (sock_flag(sk_other, SOCK_DEAD) || |
| !sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { |
| goto out_free; |
| } |
| |
| skb_bpf_set_ingress(skb); |
| |
| /* If the queue is empty then we can submit directly |
| * into the msg queue. If its not empty we have to |
| * queue work otherwise we may get OOO data. Otherwise, |
| * if sk_psock_skb_ingress errors will be handled by |
| * retrying later from workqueue. |
| */ |
| if (skb_queue_empty(&psock->ingress_skb)) { |
| err = sk_psock_skb_ingress_self(psock, skb); |
| } |
| if (err < 0) { |
| spin_lock_bh(&psock->ingress_lock); |
| if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { |
| skb_queue_tail(&psock->ingress_skb, skb); |
| schedule_work(&psock->work); |
| err = 0; |
| } |
| spin_unlock_bh(&psock->ingress_lock); |
| if (err < 0) { |
| skb_bpf_redirect_clear(skb); |
| goto out_free; |
| } |
| } |
| break; |
| case __SK_REDIRECT: |
| err = sk_psock_skb_redirect(psock, skb); |
| break; |
| case __SK_DROP: |
| default: |
| out_free: |
| sock_drop(psock->sk, skb); |
| } |
| |
| return err; |
| } |
| |
| static void sk_psock_write_space(struct sock *sk) |
| { |
| struct sk_psock *psock; |
| void (*write_space)(struct sock *sk) = NULL; |
| |
| rcu_read_lock(); |
| psock = sk_psock(sk); |
| if (likely(psock)) { |
| if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) |
| schedule_work(&psock->work); |
| write_space = psock->saved_write_space; |
| } |
| rcu_read_unlock(); |
| if (write_space) |
| write_space(sk); |
| } |
| |
| #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) |
| static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb) |
| { |
| struct sk_psock *psock; |
| struct bpf_prog *prog; |
| int ret = __SK_DROP; |
| struct sock *sk; |
| |
| rcu_read_lock(); |
| sk = strp->sk; |
| psock = sk_psock(sk); |
| if (unlikely(!psock)) { |
| sock_drop(sk, skb); |
| goto out; |
| } |
| prog = READ_ONCE(psock->progs.stream_verdict); |
| if (likely(prog)) { |
| skb->sk = sk; |
| skb_dst_drop(skb); |
| skb_bpf_redirect_clear(skb); |
| ret = bpf_prog_run_pin_on_cpu(prog, skb); |
| ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb)); |
| skb->sk = NULL; |
| } |
| sk_psock_verdict_apply(psock, skb, ret); |
| out: |
| rcu_read_unlock(); |
| } |
| |
| static int sk_psock_strp_read_done(struct strparser *strp, int err) |
| { |
| return err; |
| } |
| |
| static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb) |
| { |
| struct sk_psock *psock = container_of(strp, struct sk_psock, strp); |
| struct bpf_prog *prog; |
| int ret = skb->len; |
| |
| rcu_read_lock(); |
| prog = READ_ONCE(psock->progs.stream_parser); |
| if (likely(prog)) { |
| skb->sk = psock->sk; |
| ret = bpf_prog_run_pin_on_cpu(prog, skb); |
| skb->sk = NULL; |
| } |
| rcu_read_unlock(); |
| return ret; |
| } |
| |
| /* Called with socket lock held. */ |
| static void sk_psock_strp_data_ready(struct sock *sk) |
| { |
| struct sk_psock *psock; |
| |
| rcu_read_lock(); |
| psock = sk_psock(sk); |
| if (likely(psock)) { |
| if (tls_sw_has_ctx_rx(sk)) { |
| psock->saved_data_ready(sk); |
| } else { |
| write_lock_bh(&sk->sk_callback_lock); |
| strp_data_ready(&psock->strp); |
| write_unlock_bh(&sk->sk_callback_lock); |
| } |
| } |
| rcu_read_unlock(); |
| } |
| |
| int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock) |
| { |
| static const struct strp_callbacks cb = { |
| .rcv_msg = sk_psock_strp_read, |
| .read_sock_done = sk_psock_strp_read_done, |
| .parse_msg = sk_psock_strp_parse, |
| }; |
| |
| return strp_init(&psock->strp, sk, &cb); |
| } |
| |
| void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock) |
| { |
| if (psock->saved_data_ready) |
| return; |
| |
| psock->saved_data_ready = sk->sk_data_ready; |
| sk->sk_data_ready = sk_psock_strp_data_ready; |
| sk->sk_write_space = sk_psock_write_space; |
| } |
| |
| void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock) |
| { |
| if (!psock->saved_data_ready) |
| return; |
| |
| sk->sk_data_ready = psock->saved_data_ready; |
| psock->saved_data_ready = NULL; |
| strp_stop(&psock->strp); |
| } |
| |
| static void sk_psock_done_strp(struct sk_psock *psock) |
| { |
| /* Parser has been stopped */ |
| if (psock->progs.stream_parser) |
| strp_done(&psock->strp); |
| } |
| #else |
| static void sk_psock_done_strp(struct sk_psock *psock) |
| { |
| } |
| #endif /* CONFIG_BPF_STREAM_PARSER */ |
| |
| static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb, |
| unsigned int offset, size_t orig_len) |
| { |
| struct sock *sk = (struct sock *)desc->arg.data; |
| struct sk_psock *psock; |
| struct bpf_prog *prog; |
| int ret = __SK_DROP; |
| int len = skb->len; |
| |
| /* clone here so sk_eat_skb() in tcp_read_sock does not drop our data */ |
| skb = skb_clone(skb, GFP_ATOMIC); |
| if (!skb) { |
| desc->error = -ENOMEM; |
| return 0; |
| } |
| |
| rcu_read_lock(); |
| psock = sk_psock(sk); |
| if (unlikely(!psock)) { |
| len = 0; |
| sock_drop(sk, skb); |
| goto out; |
| } |
| prog = READ_ONCE(psock->progs.stream_verdict); |
| if (!prog) |
| prog = READ_ONCE(psock->progs.skb_verdict); |
| if (likely(prog)) { |
| skb->sk = sk; |
| skb_dst_drop(skb); |
| skb_bpf_redirect_clear(skb); |
| ret = bpf_prog_run_pin_on_cpu(prog, skb); |
| ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb)); |
| skb->sk = NULL; |
| } |
| if (sk_psock_verdict_apply(psock, skb, ret) < 0) |
| len = 0; |
| out: |
| rcu_read_unlock(); |
| return len; |
| } |
| |
| static void sk_psock_verdict_data_ready(struct sock *sk) |
| { |
| struct socket *sock = sk->sk_socket; |
| read_descriptor_t desc; |
| |
| if (unlikely(!sock || !sock->ops || !sock->ops->read_sock)) |
| return; |
| |
| desc.arg.data = sk; |
| desc.error = 0; |
| desc.count = 1; |
| |
| sock->ops->read_sock(sk, &desc, sk_psock_verdict_recv); |
| } |
| |
| void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock) |
| { |
| if (psock->saved_data_ready) |
| return; |
| |
| psock->saved_data_ready = sk->sk_data_ready; |
| sk->sk_data_ready = sk_psock_verdict_data_ready; |
| sk->sk_write_space = sk_psock_write_space; |
| } |
| |
| void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock) |
| { |
| if (!psock->saved_data_ready) |
| return; |
| |
| sk->sk_data_ready = psock->saved_data_ready; |
| psock->saved_data_ready = NULL; |
| } |