1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
4 #include <linux/skmsg.h>
5 #include <linux/filter.h>
7 #include <linux/init.h>
8 #include <linux/wait.h>
10 #include <net/inet_common.h>
13 static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
14 struct sk_msg *msg, u32 apply_bytes, int flags)
16 bool apply = apply_bytes;
17 struct scatterlist *sge;
22 tmp = kzalloc(sizeof(*tmp), __GFP_NOWARN | GFP_KERNEL);
27 tmp->sg.start = msg->sg.start;
30 sge = sk_msg_elem(msg, i);
31 size = (apply && apply_bytes < sge->length) ?
32 apply_bytes : sge->length;
33 if (!sk_wmem_schedule(sk, size)) {
39 sk_mem_charge(sk, size);
40 sk_msg_xfer(tmp, msg, i, size);
43 get_page(sk_msg_page(tmp, i));
44 sk_msg_iter_var_next(i);
51 } while (i != msg->sg.end);
55 sk_psock_queue_msg(psock, tmp);
56 sk_psock_data_ready(sk, psock);
66 static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
67 int flags, bool uncharge)
69 bool apply = apply_bytes;
70 struct scatterlist *sge;
78 sge = sk_msg_elem(msg, msg->sg.start);
79 size = (apply && apply_bytes < sge->length) ?
80 apply_bytes : sge->length;
84 tcp_rate_check_app_limited(sk);
86 has_tx_ulp = tls_sw_has_ctx_tx(sk);
88 flags |= MSG_SENDPAGE_NOPOLICY;
89 ret = kernel_sendpage_locked(sk,
90 page, off, size, flags);
92 ret = do_tcp_sendpages(sk, page, off, size, flags);
103 sk_mem_uncharge(sk, ret);
111 sk_msg_iter_next(msg, start);
112 sg_init_table(sge, 1);
113 if (msg->sg.start == msg->sg.end)
116 if (apply && !apply_bytes)
123 static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg,
124 u32 apply_bytes, int flags, bool uncharge)
129 ret = tcp_bpf_push(sk, msg, apply_bytes, flags, uncharge);
134 int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg,
135 u32 bytes, int flags)
137 bool ingress = sk_msg_to_ingress(msg);
138 struct sk_psock *psock = sk_psock_get(sk);
141 if (unlikely(!psock)) {
142 sk_msg_free(sk, msg);
145 ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) :
146 tcp_bpf_push_locked(sk, msg, bytes, flags, false);
147 sk_psock_put(sk, psock);
150 EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir);
152 #ifdef CONFIG_BPF_SYSCALL
153 static bool tcp_bpf_stream_read(const struct sock *sk)
155 struct sk_psock *psock;
159 psock = sk_psock(sk);
161 empty = list_empty(&psock->ingress_msg);
166 static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
167 int nonblock, int flags, int *addr_len)
169 struct sk_psock *psock;
172 if (unlikely(flags & MSG_ERRQUEUE))
173 return inet_recv_error(sk, msg, len, addr_len);
175 psock = sk_psock_get(sk);
176 if (unlikely(!psock))
177 return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
178 if (!skb_queue_empty(&sk->sk_receive_queue) &&
179 sk_psock_queue_empty(psock)) {
180 sk_psock_put(sk, psock);
181 return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
185 copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
190 timeo = sock_rcvtimeo(sk, nonblock);
191 data = sk_msg_wait_data(sk, psock, flags, timeo, &err);
193 if (!sk_psock_queue_empty(psock))
194 goto msg_bytes_ready;
196 sk_psock_put(sk, psock);
197 return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
208 sk_psock_put(sk, psock);
212 static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
213 struct sk_msg *msg, int *copied, int flags)
215 bool cork = false, enospc = sk_msg_full(msg);
216 struct sock *sk_redir;
217 u32 tosend, delta = 0;
221 if (psock->eval == __SK_NONE) {
222 /* Track delta in msg size to add/subtract it on SK_DROP from
223 * returned to user copied size. This ensures user doesn't
224 * get a positive return code with msg_cut_data and SK_DROP
227 delta = msg->sg.size;
228 psock->eval = sk_psock_msg_verdict(sk, psock, msg);
229 delta -= msg->sg.size;
232 if (msg->cork_bytes &&
233 msg->cork_bytes > msg->sg.size && !enospc) {
234 psock->cork_bytes = msg->cork_bytes - msg->sg.size;
236 psock->cork = kzalloc(sizeof(*psock->cork),
237 GFP_ATOMIC | __GFP_NOWARN);
241 memcpy(psock->cork, msg, sizeof(*msg));
245 tosend = msg->sg.size;
246 if (psock->apply_bytes && psock->apply_bytes < tosend)
247 tosend = psock->apply_bytes;
249 switch (psock->eval) {
251 ret = tcp_bpf_push(sk, msg, tosend, flags, true);
253 *copied -= sk_msg_free(sk, msg);
256 sk_msg_apply_bytes(psock, tosend);
259 sk_redir = psock->sk_redir;
260 sk_msg_apply_bytes(psock, tosend);
265 sk_msg_return(sk, msg, tosend);
267 ret = tcp_bpf_sendmsg_redir(sk_redir, msg, tosend, flags);
269 if (unlikely(ret < 0)) {
270 int free = sk_msg_free_nocharge(sk, msg);
276 sk_msg_free(sk, msg);
284 sk_msg_free_partial(sk, msg, tosend);
285 sk_msg_apply_bytes(psock, tosend);
286 *copied -= (tosend + delta);
291 if (!psock->apply_bytes) {
292 psock->eval = __SK_NONE;
293 if (psock->sk_redir) {
294 sock_put(psock->sk_redir);
295 psock->sk_redir = NULL;
299 msg->sg.data[msg->sg.start].page_link &&
300 msg->sg.data[msg->sg.start].length)
306 static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
308 struct sk_msg tmp, *msg_tx = NULL;
309 int copied = 0, err = 0;
310 struct sk_psock *psock;
314 /* Don't let internal do_tcp_sendpages() flags through */
315 flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED);
316 flags |= MSG_NO_SHARED_FRAGS;
318 psock = sk_psock_get(sk);
319 if (unlikely(!psock))
320 return tcp_sendmsg(sk, msg, size);
323 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
324 while (msg_data_left(msg)) {
333 copy = msg_data_left(msg);
334 if (!sk_stream_memory_free(sk))
335 goto wait_for_sndbuf;
337 msg_tx = psock->cork;
343 osize = msg_tx->sg.size;
344 err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1);
347 goto wait_for_memory;
349 copy = msg_tx->sg.size - osize;
352 err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx,
355 sk_msg_trim(sk, msg_tx, osize);
360 if (psock->cork_bytes) {
361 if (size > psock->cork_bytes)
362 psock->cork_bytes = 0;
364 psock->cork_bytes -= size;
365 if (psock->cork_bytes && !enospc)
367 /* All cork bytes are accounted, rerun the prog. */
368 psock->eval = __SK_NONE;
369 psock->cork_bytes = 0;
372 err = tcp_bpf_send_verdict(sk, psock, msg_tx, &copied, flags);
373 if (unlikely(err < 0))
377 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
379 err = sk_stream_wait_memory(sk, &timeo);
381 if (msg_tx && msg_tx != psock->cork)
382 sk_msg_free(sk, msg_tx);
388 err = sk_stream_error(sk, msg->msg_flags, err);
390 sk_psock_put(sk, psock);
391 return copied ? copied : err;
394 static int tcp_bpf_sendpage(struct sock *sk, struct page *page, int offset,
395 size_t size, int flags)
397 struct sk_msg tmp, *msg = NULL;
398 int err = 0, copied = 0;
399 struct sk_psock *psock;
402 psock = sk_psock_get(sk);
403 if (unlikely(!psock))
404 return tcp_sendpage(sk, page, offset, size, flags);
414 /* Catch case where ring is full and sendpage is stalled. */
415 if (unlikely(sk_msg_full(msg)))
418 sk_msg_page_add(msg, page, size, offset);
419 sk_mem_charge(sk, size);
421 if (sk_msg_full(msg))
423 if (psock->cork_bytes) {
424 if (size > psock->cork_bytes)
425 psock->cork_bytes = 0;
427 psock->cork_bytes -= size;
428 if (psock->cork_bytes && !enospc)
430 /* All cork bytes are accounted, rerun the prog. */
431 psock->eval = __SK_NONE;
432 psock->cork_bytes = 0;
435 err = tcp_bpf_send_verdict(sk, psock, msg, &copied, flags);
438 sk_psock_put(sk, psock);
439 return copied ? copied : err;
454 static struct proto *tcpv6_prot_saved __read_mostly;
455 static DEFINE_SPINLOCK(tcpv6_prot_lock);
456 static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS];
458 static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],
461 prot[TCP_BPF_BASE] = *base;
462 prot[TCP_BPF_BASE].unhash = sock_map_unhash;
463 prot[TCP_BPF_BASE].close = sock_map_close;
464 prot[TCP_BPF_BASE].recvmsg = tcp_bpf_recvmsg;
465 prot[TCP_BPF_BASE].stream_memory_read = tcp_bpf_stream_read;
467 prot[TCP_BPF_TX] = prot[TCP_BPF_BASE];
468 prot[TCP_BPF_TX].sendmsg = tcp_bpf_sendmsg;
469 prot[TCP_BPF_TX].sendpage = tcp_bpf_sendpage;
472 static void tcp_bpf_check_v6_needs_rebuild(struct proto *ops)
474 if (unlikely(ops != smp_load_acquire(&tcpv6_prot_saved))) {
475 spin_lock_bh(&tcpv6_prot_lock);
476 if (likely(ops != tcpv6_prot_saved)) {
477 tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV6], ops);
478 smp_store_release(&tcpv6_prot_saved, ops);
480 spin_unlock_bh(&tcpv6_prot_lock);
484 static int __init tcp_bpf_v4_build_proto(void)
486 tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot);
489 late_initcall(tcp_bpf_v4_build_proto);
491 static int tcp_bpf_assert_proto_ops(struct proto *ops)
493 /* In order to avoid retpoline, we make assumptions when we call
494 * into ops if e.g. a psock is not present. Make sure they are
495 * indeed valid assumptions.
497 return ops->recvmsg == tcp_recvmsg &&
498 ops->sendmsg == tcp_sendmsg &&
499 ops->sendpage == tcp_sendpage ? 0 : -ENOTSUPP;
502 int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
504 int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
505 int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE;
508 if (inet_csk_has_ulp(sk)) {
509 /* TLS does not have an unhash proto in SW cases,
510 * but we need to ensure we stop using the sock_map
511 * unhash routine because the associated psock is being
512 * removed. So use the original unhash handler.
514 WRITE_ONCE(sk->sk_prot->unhash, psock->saved_unhash);
515 tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space);
517 sk->sk_write_space = psock->saved_write_space;
518 /* Pairs with lockless read in sk_clone_lock() */
519 WRITE_ONCE(sk->sk_prot, psock->sk_proto);
524 if (inet_csk_has_ulp(sk))
527 if (sk->sk_family == AF_INET6) {
528 if (tcp_bpf_assert_proto_ops(psock->sk_proto))
531 tcp_bpf_check_v6_needs_rebuild(psock->sk_proto);
534 /* Pairs with lockless read in sk_clone_lock() */
535 WRITE_ONCE(sk->sk_prot, &tcp_bpf_prots[family][config]);
538 EXPORT_SYMBOL_GPL(tcp_bpf_update_proto);
540 /* If a child got cloned from a listening socket that had tcp_bpf
541 * protocol callbacks installed, we need to restore the callbacks to
542 * the default ones because the child does not inherit the psock state
543 * that tcp_bpf callbacks expect.
545 void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
547 int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
548 struct proto *prot = newsk->sk_prot;
550 if (prot == &tcp_bpf_prots[family][TCP_BPF_BASE])
551 newsk->sk_prot = sk->sk_prot_creator;
553 #endif /* CONFIG_BPF_SYSCALL */