Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
new file mode 100644
index 0000000..e387051
--- /dev/null
+++ b/net/ipv4/tcp_bpf.c
@@ -0,0 +1,696 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
+
+#include <linux/skmsg.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+
+#include <net/inet_common.h>
+#include <net/tls.h>
+
+static bool tcp_bpf_stream_read(const 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;
+}
+
+static int tcp_bpf_wait_data(struct sock *sk, struct sk_psock *psock,
+ int flags, long timeo, int *err)
+{
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ int ret = 0;
+
+ if (!timeo)
+ return ret;
+
+ add_wait_queue(sk_sleep(sk), &wait);
+ sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+ ret = sk_wait_event(sk, &timeo,
+ !list_empty(&psock->ingress_msg) ||
+ !skb_queue_empty(&sk->sk_receive_queue), &wait);
+ sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+ remove_wait_queue(sk_sleep(sk), &wait);
+ return ret;
+}
+
+int __tcp_bpf_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;
+ int i, ret, copied = 0;
+ struct sk_msg *msg_rx;
+
+ msg_rx = list_first_entry_or_null(&psock->ingress_msg,
+ struct sk_msg, list);
+
+ 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;
+ ret = copy_page_to_iter(page, sge->offset, copy, iter);
+ if (ret != copy) {
+ msg_rx->sg.start = i;
+ return -EFAULT;
+ }
+
+ copied += copy;
+ if (likely(!peek)) {
+ sge->offset += copy;
+ sge->length -= copy;
+ 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 {
+ sk_msg_iter_var_next(i);
+ }
+
+ if (copied == len)
+ break;
+ } while (i != msg_rx->sg.end);
+
+ if (unlikely(peek)) {
+ msg_rx = list_next_entry(msg_rx, list);
+ continue;
+ }
+
+ msg_rx->sg.start = i;
+ if (!sge->length && msg_rx->sg.start == msg_rx->sg.end) {
+ list_del(&msg_rx->list);
+ if (msg_rx->skb)
+ consume_skb(msg_rx->skb);
+ kfree(msg_rx);
+ }
+ msg_rx = list_first_entry_or_null(&psock->ingress_msg,
+ struct sk_msg, list);
+ }
+
+ return copied;
+}
+EXPORT_SYMBOL_GPL(__tcp_bpf_recvmsg);
+
+int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+ int nonblock, int flags, int *addr_len)
+{
+ struct sk_psock *psock;
+ int copied, ret;
+
+ if (unlikely(flags & MSG_ERRQUEUE))
+ return inet_recv_error(sk, msg, len, addr_len);
+ if (!skb_queue_empty(&sk->sk_receive_queue))
+ return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+
+ psock = sk_psock_get(sk);
+ if (unlikely(!psock))
+ return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+ lock_sock(sk);
+msg_bytes_ready:
+ copied = __tcp_bpf_recvmsg(sk, psock, msg, len, flags);
+ if (!copied) {
+ int data, err = 0;
+ long timeo;
+
+ timeo = sock_rcvtimeo(sk, nonblock);
+ data = tcp_bpf_wait_data(sk, psock, flags, timeo, &err);
+ if (data) {
+ if (skb_queue_empty(&sk->sk_receive_queue))
+ goto msg_bytes_ready;
+ release_sock(sk);
+ sk_psock_put(sk, psock);
+ return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+ }
+ if (err) {
+ ret = err;
+ goto out;
+ }
+ copied = -EAGAIN;
+ }
+ ret = copied;
+out:
+ release_sock(sk);
+ sk_psock_put(sk, psock);
+ return ret;
+}
+
+static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
+ struct sk_msg *msg, u32 apply_bytes, int flags)
+{
+ bool apply = apply_bytes;
+ struct scatterlist *sge;
+ u32 size, copied = 0;
+ struct sk_msg *tmp;
+ int i, ret = 0;
+
+ tmp = kzalloc(sizeof(*tmp), __GFP_NOWARN | GFP_KERNEL);
+ if (unlikely(!tmp))
+ return -ENOMEM;
+
+ lock_sock(sk);
+ tmp->sg.start = msg->sg.start;
+ i = msg->sg.start;
+ do {
+ sge = sk_msg_elem(msg, i);
+ size = (apply && apply_bytes < sge->length) ?
+ apply_bytes : sge->length;
+ if (!sk_wmem_schedule(sk, size)) {
+ if (!copied)
+ ret = -ENOMEM;
+ break;
+ }
+
+ sk_mem_charge(sk, size);
+ sk_msg_xfer(tmp, msg, i, size);
+ copied += size;
+ if (sge->length)
+ get_page(sk_msg_page(tmp, i));
+ sk_msg_iter_var_next(i);
+ tmp->sg.end = i;
+ if (apply) {
+ apply_bytes -= size;
+ if (!apply_bytes)
+ break;
+ }
+ } while (i != msg->sg.end);
+
+ if (!ret) {
+ msg->sg.start = i;
+ msg->sg.size -= apply_bytes;
+ sk_psock_queue_msg(psock, tmp);
+ sk_psock_data_ready(sk, psock);
+ } else {
+ sk_msg_free(sk, tmp);
+ kfree(tmp);
+ }
+
+ release_sock(sk);
+ return ret;
+}
+
+static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
+ int flags, bool uncharge)
+{
+ bool apply = apply_bytes;
+ struct scatterlist *sge;
+ struct page *page;
+ int size, ret = 0;
+ u32 off;
+
+ while (1) {
+ bool has_tx_ulp;
+
+ sge = sk_msg_elem(msg, msg->sg.start);
+ size = (apply && apply_bytes < sge->length) ?
+ apply_bytes : sge->length;
+ off = sge->offset;
+ page = sg_page(sge);
+
+ tcp_rate_check_app_limited(sk);
+retry:
+ has_tx_ulp = tls_sw_has_ctx_tx(sk);
+ if (has_tx_ulp) {
+ flags |= MSG_SENDPAGE_NOPOLICY;
+ ret = kernel_sendpage_locked(sk,
+ page, off, size, flags);
+ } else {
+ ret = do_tcp_sendpages(sk, page, off, size, flags);
+ }
+
+ if (ret <= 0)
+ return ret;
+ if (apply)
+ apply_bytes -= ret;
+ msg->sg.size -= ret;
+ sge->offset += ret;
+ sge->length -= ret;
+ if (uncharge)
+ sk_mem_uncharge(sk, ret);
+ if (ret != size) {
+ size -= ret;
+ off += ret;
+ goto retry;
+ }
+ if (!sge->length) {
+ put_page(page);
+ sk_msg_iter_next(msg, start);
+ sg_init_table(sge, 1);
+ if (msg->sg.start == msg->sg.end)
+ break;
+ }
+ if (apply && !apply_bytes)
+ break;
+ }
+
+ return 0;
+}
+
+static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg,
+ u32 apply_bytes, int flags, bool uncharge)
+{
+ int ret;
+
+ lock_sock(sk);
+ ret = tcp_bpf_push(sk, msg, apply_bytes, flags, uncharge);
+ release_sock(sk);
+ return ret;
+}
+
+int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg,
+ u32 bytes, int flags)
+{
+ bool ingress = sk_msg_to_ingress(msg);
+ struct sk_psock *psock = sk_psock_get(sk);
+ int ret;
+
+ if (unlikely(!psock)) {
+ sk_msg_free(sk, msg);
+ return 0;
+ }
+ ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) :
+ tcp_bpf_push_locked(sk, msg, bytes, flags, false);
+ sk_psock_put(sk, psock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir);
+
+static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
+ struct sk_msg *msg, int *copied, int flags)
+{
+ bool cork = false, enospc = sk_msg_full(msg);
+ struct sock *sk_redir;
+ u32 tosend, delta = 0;
+ int ret;
+
+more_data:
+ if (psock->eval == __SK_NONE) {
+ /* Track delta in msg size to add/subtract it on SK_DROP from
+ * returned to user copied size. This ensures user doesn't
+ * get a positive return code with msg_cut_data and SK_DROP
+ * verdict.
+ */
+ delta = msg->sg.size;
+ psock->eval = sk_psock_msg_verdict(sk, psock, msg);
+ if (msg->sg.size < delta)
+ delta -= msg->sg.size;
+ else
+ delta = 0;
+ }
+
+ if (msg->cork_bytes &&
+ msg->cork_bytes > msg->sg.size && !enospc) {
+ psock->cork_bytes = msg->cork_bytes - msg->sg.size;
+ if (!psock->cork) {
+ psock->cork = kzalloc(sizeof(*psock->cork),
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (!psock->cork)
+ return -ENOMEM;
+ }
+ memcpy(psock->cork, msg, sizeof(*msg));
+ return 0;
+ }
+
+ tosend = msg->sg.size;
+ if (psock->apply_bytes && psock->apply_bytes < tosend)
+ tosend = psock->apply_bytes;
+
+ switch (psock->eval) {
+ case __SK_PASS:
+ ret = tcp_bpf_push(sk, msg, tosend, flags, true);
+ if (unlikely(ret)) {
+ *copied -= sk_msg_free(sk, msg);
+ break;
+ }
+ sk_msg_apply_bytes(psock, tosend);
+ break;
+ case __SK_REDIRECT:
+ sk_redir = psock->sk_redir;
+ sk_msg_apply_bytes(psock, tosend);
+ if (psock->cork) {
+ cork = true;
+ psock->cork = NULL;
+ }
+ sk_msg_return(sk, msg, tosend);
+ release_sock(sk);
+ ret = tcp_bpf_sendmsg_redir(sk_redir, msg, tosend, flags);
+ lock_sock(sk);
+ if (unlikely(ret < 0)) {
+ int free = sk_msg_free_nocharge(sk, msg);
+
+ if (!cork)
+ *copied -= free;
+ }
+ if (cork) {
+ sk_msg_free(sk, msg);
+ kfree(msg);
+ msg = NULL;
+ ret = 0;
+ }
+ break;
+ case __SK_DROP:
+ default:
+ sk_msg_free_partial(sk, msg, tosend);
+ sk_msg_apply_bytes(psock, tosend);
+ *copied -= (tosend + delta);
+ return -EACCES;
+ }
+
+ if (likely(!ret)) {
+ if (!psock->apply_bytes) {
+ psock->eval = __SK_NONE;
+ if (psock->sk_redir) {
+ sock_put(psock->sk_redir);
+ psock->sk_redir = NULL;
+ }
+ }
+ if (msg &&
+ msg->sg.data[msg->sg.start].page_link &&
+ msg->sg.data[msg->sg.start].length)
+ goto more_data;
+ }
+ return ret;
+}
+
+static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
+{
+ struct sk_msg tmp, *msg_tx = NULL;
+ int copied = 0, err = 0;
+ struct sk_psock *psock;
+ long timeo;
+ int flags;
+
+ /* Don't let internal do_tcp_sendpages() flags through */
+ flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED);
+ flags |= MSG_NO_SHARED_FRAGS;
+
+ psock = sk_psock_get(sk);
+ if (unlikely(!psock))
+ return tcp_sendmsg(sk, msg, size);
+
+ lock_sock(sk);
+ timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+ while (msg_data_left(msg)) {
+ bool enospc = false;
+ u32 copy, osize;
+
+ if (sk->sk_err) {
+ err = -sk->sk_err;
+ goto out_err;
+ }
+
+ copy = msg_data_left(msg);
+ if (!sk_stream_memory_free(sk))
+ goto wait_for_sndbuf;
+ if (psock->cork) {
+ msg_tx = psock->cork;
+ } else {
+ msg_tx = &tmp;
+ sk_msg_init(msg_tx);
+ }
+
+ osize = msg_tx->sg.size;
+ err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1);
+ if (err) {
+ if (err != -ENOSPC)
+ goto wait_for_memory;
+ enospc = true;
+ copy = msg_tx->sg.size - osize;
+ }
+
+ err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx,
+ copy);
+ if (err < 0) {
+ sk_msg_trim(sk, msg_tx, osize);
+ goto out_err;
+ }
+
+ copied += copy;
+ if (psock->cork_bytes) {
+ if (size > psock->cork_bytes)
+ psock->cork_bytes = 0;
+ else
+ psock->cork_bytes -= size;
+ if (psock->cork_bytes && !enospc)
+ goto out_err;
+ /* All cork bytes are accounted, rerun the prog. */
+ psock->eval = __SK_NONE;
+ psock->cork_bytes = 0;
+ }
+
+ err = tcp_bpf_send_verdict(sk, psock, msg_tx, &copied, flags);
+ if (unlikely(err < 0))
+ goto out_err;
+ continue;
+wait_for_sndbuf:
+ set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+wait_for_memory:
+ err = sk_stream_wait_memory(sk, &timeo);
+ if (err) {
+ if (msg_tx && msg_tx != psock->cork)
+ sk_msg_free(sk, msg_tx);
+ goto out_err;
+ }
+ }
+out_err:
+ if (err < 0)
+ err = sk_stream_error(sk, msg->msg_flags, err);
+ release_sock(sk);
+ sk_psock_put(sk, psock);
+ return copied ? copied : err;
+}
+
+static int tcp_bpf_sendpage(struct sock *sk, struct page *page, int offset,
+ size_t size, int flags)
+{
+ struct sk_msg tmp, *msg = NULL;
+ int err = 0, copied = 0;
+ struct sk_psock *psock;
+ bool enospc = false;
+
+ psock = sk_psock_get(sk);
+ if (unlikely(!psock))
+ return tcp_sendpage(sk, page, offset, size, flags);
+
+ lock_sock(sk);
+ if (psock->cork) {
+ msg = psock->cork;
+ } else {
+ msg = &tmp;
+ sk_msg_init(msg);
+ }
+
+ /* Catch case where ring is full and sendpage is stalled. */
+ if (unlikely(sk_msg_full(msg)))
+ goto out_err;
+
+ sk_msg_page_add(msg, page, size, offset);
+ sk_mem_charge(sk, size);
+ copied = size;
+ if (sk_msg_full(msg))
+ enospc = true;
+ if (psock->cork_bytes) {
+ if (size > psock->cork_bytes)
+ psock->cork_bytes = 0;
+ else
+ psock->cork_bytes -= size;
+ if (psock->cork_bytes && !enospc)
+ goto out_err;
+ /* All cork bytes are accounted, rerun the prog. */
+ psock->eval = __SK_NONE;
+ psock->cork_bytes = 0;
+ }
+
+ err = tcp_bpf_send_verdict(sk, psock, msg, &copied, flags);
+out_err:
+ release_sock(sk);
+ sk_psock_put(sk, psock);
+ return copied ? copied : err;
+}
+
+static void tcp_bpf_remove(struct sock *sk, struct sk_psock *psock)
+{
+ struct sk_psock_link *link;
+
+ while ((link = sk_psock_link_pop(psock))) {
+ sk_psock_unlink(sk, link);
+ sk_psock_free_link(link);
+ }
+}
+
+static void tcp_bpf_unhash(struct sock *sk)
+{
+ void (*saved_unhash)(struct sock *sk);
+ struct sk_psock *psock;
+
+ rcu_read_lock();
+ psock = sk_psock(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ if (sk->sk_prot->unhash)
+ sk->sk_prot->unhash(sk);
+ return;
+ }
+
+ saved_unhash = psock->saved_unhash;
+ tcp_bpf_remove(sk, psock);
+ rcu_read_unlock();
+ saved_unhash(sk);
+}
+
+static void tcp_bpf_close(struct sock *sk, long timeout)
+{
+ void (*saved_close)(struct sock *sk, long timeout);
+ struct sk_psock *psock;
+
+ lock_sock(sk);
+ rcu_read_lock();
+ psock = sk_psock(sk);
+ if (unlikely(!psock)) {
+ rcu_read_unlock();
+ release_sock(sk);
+ return sk->sk_prot->close(sk, timeout);
+ }
+
+ saved_close = psock->saved_close;
+ tcp_bpf_remove(sk, psock);
+ rcu_read_unlock();
+ release_sock(sk);
+ saved_close(sk, timeout);
+}
+
+enum {
+ TCP_BPF_IPV4,
+ TCP_BPF_IPV6,
+ TCP_BPF_NUM_PROTS,
+};
+
+enum {
+ TCP_BPF_BASE,
+ TCP_BPF_TX,
+ TCP_BPF_NUM_CFGS,
+};
+
+static struct proto *tcpv6_prot_saved __read_mostly;
+static DEFINE_SPINLOCK(tcpv6_prot_lock);
+static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS];
+
+static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],
+ struct proto *base)
+{
+ prot[TCP_BPF_BASE] = *base;
+ prot[TCP_BPF_BASE].unhash = tcp_bpf_unhash;
+ prot[TCP_BPF_BASE].close = tcp_bpf_close;
+ prot[TCP_BPF_BASE].recvmsg = tcp_bpf_recvmsg;
+ prot[TCP_BPF_BASE].stream_memory_read = tcp_bpf_stream_read;
+
+ prot[TCP_BPF_TX] = prot[TCP_BPF_BASE];
+ prot[TCP_BPF_TX].sendmsg = tcp_bpf_sendmsg;
+ prot[TCP_BPF_TX].sendpage = tcp_bpf_sendpage;
+}
+
+static void tcp_bpf_check_v6_needs_rebuild(struct sock *sk, struct proto *ops)
+{
+ if (sk->sk_family == AF_INET6 &&
+ unlikely(ops != smp_load_acquire(&tcpv6_prot_saved))) {
+ spin_lock_bh(&tcpv6_prot_lock);
+ if (likely(ops != tcpv6_prot_saved)) {
+ tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV6], ops);
+ smp_store_release(&tcpv6_prot_saved, ops);
+ }
+ spin_unlock_bh(&tcpv6_prot_lock);
+ }
+}
+
+static int __init tcp_bpf_v4_build_proto(void)
+{
+ tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot);
+ return 0;
+}
+core_initcall(tcp_bpf_v4_build_proto);
+
+static void tcp_bpf_update_sk_prot(struct sock *sk, struct sk_psock *psock)
+{
+ int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
+ int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE;
+
+ sk_psock_update_proto(sk, psock, &tcp_bpf_prots[family][config]);
+}
+
+static void tcp_bpf_reinit_sk_prot(struct sock *sk, struct sk_psock *psock)
+{
+ int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
+ int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE;
+
+ /* Reinit occurs when program types change e.g. TCP_BPF_TX is removed
+ * or added requiring sk_prot hook updates. We keep original saved
+ * hooks in this case.
+ */
+ sk->sk_prot = &tcp_bpf_prots[family][config];
+}
+
+static int tcp_bpf_assert_proto_ops(struct proto *ops)
+{
+ /* In order to avoid retpoline, we make assumptions when we call
+ * into ops if e.g. a psock is not present. Make sure they are
+ * indeed valid assumptions.
+ */
+ return ops->recvmsg == tcp_recvmsg &&
+ ops->sendmsg == tcp_sendmsg &&
+ ops->sendpage == tcp_sendpage ? 0 : -ENOTSUPP;
+}
+
+void tcp_bpf_reinit(struct sock *sk)
+{
+ struct sk_psock *psock;
+
+ sock_owned_by_me(sk);
+
+ rcu_read_lock();
+ psock = sk_psock(sk);
+ tcp_bpf_reinit_sk_prot(sk, psock);
+ rcu_read_unlock();
+}
+
+int tcp_bpf_init(struct sock *sk)
+{
+ struct proto *ops = READ_ONCE(sk->sk_prot);
+ struct sk_psock *psock;
+
+ sock_owned_by_me(sk);
+
+ rcu_read_lock();
+ psock = sk_psock(sk);
+ if (unlikely(!psock || psock->sk_proto ||
+ tcp_bpf_assert_proto_ops(ops))) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+ tcp_bpf_check_v6_needs_rebuild(sk, ops);
+ tcp_bpf_update_sk_prot(sk, psock);
+ rcu_read_unlock();
+ return 0;
+}