Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-10-16

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Convert BPF sockmap and kTLS to both use a new sk_msg API and enable
   sk_msg BPF integration for the latter, from Daniel and John.

2) Enable BPF syscall side to indicate for maps that they do not support
   a map lookup operation as opposed to just missing key, from Prashant.

3) Add bpftool map create command which after map creation pins the
   map into bpf fs for further processing, from Jakub.

4) Add bpftool support for attaching programs to maps allowing sock_map
   and sock_hash to be used from bpftool, from John.

5) Improve syscall BPF map update/delete path for map-in-map types to
   wait a RCU grace period for pending references to complete, from Daniel.

6) Couple of follow-up fixes for the BPF socket lookup to get it
   enabled also when IPv6 is compiled as a module, from Joe.

7) Fix a generic-XDP bug to handle the case when the Ethernet header
   was mangled and thus update skb's protocol and data, from Jesper.

8) Add a missing BTF header length check between header copies from
   user space, from Wenwen.

9) Minor fixups in libbpf to use __u32 instead u32 types and include
   proper perf_event.h uapi header instead of perf internal one, from Yonghong.

10) Allow to pass user-defined flags through EXTRA_CFLAGS and EXTRA_LDFLAGS
    to bpftool's build, from Jiri.

11) BPF kselftest tweaks to add LWTUNNEL to config fragment and to install
    with_addr.sh script from flow dissector selftest, from Anders.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 655 insertions, 0 deletions

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
new file mode 100644
index 000000000000..80debb0daf37
--- /dev/null
+++ b/net/ipv4/tcp_bpf.c
@@ -0,0 +1,655 @@
+// 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>
+
+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;
+
+	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)
+{
+	struct iov_iter *iter = &msg->msg_iter;
+	int i, ret, copied = 0;
+
+	while (copied != len) {
+		struct scatterlist *sge;
+		struct sk_msg *msg_rx;
+
+		msg_rx = list_first_entry_or_null(&psock->ingress_msg,
+						  struct sk_msg, list);
+		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;
+			sge->offset += copy;
+			sge->length -= copy;
+			sk_mem_uncharge(sk, copy);
+			if (!sge->length) {
+				i++;
+				if (i == MAX_SKB_FRAGS)
+					i = 0;
+				if (!msg_rx->skb)
+					put_page(page);
+			}
+
+			if (copied == len)
+				break;
+		} while (i != msg_rx->sg.end);
+
+		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);
+		}
+	}
+
+	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);
+	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;
+		}
+	}
+	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->sk_data_ready(sk);
+	} 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) {
+		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:
+		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 = msg->sg.start == msg->sg.end;
+	struct sock *sk_redir;
+	u32 tosend;
+	int ret;
+
+more_data:
+	if (psock->eval == __SK_NONE)
+		psock->eval = sk_psock_msg_verdict(sk, psock, msg);
+
+	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;
+		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 flags = msg->msg_flags | MSG_NO_SHARED_FRAGS;
+	int copied = 0, err = 0;
+	struct sk_psock *psock;
+	long timeo;
+
+	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;
+
+	sk_psock_cork_free(psock);
+	__sk_psock_purge_ingress_msg(psock);
+	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;
+}