1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
8 #include <linux/filter.h>
9 #include <linux/scatterlist.h>
10 #include <linux/skbuff.h>
14 #include <net/strparser.h>
16 #define MAX_MSG_FRAGS MAX_SKB_FRAGS
17 #define NR_MSG_FRAG_IDS (MAX_MSG_FRAGS + 1)
33 /* The extra two elements:
34 * 1) used for chaining the front and sections when the list becomes
35 * partitioned (e.g. end < start). The crypto APIs require the
37 * 2) to chain tailer SG entries after the message.
39 struct scatterlist data[MAX_MSG_FRAGS + 2];
41 static_assert(BITS_PER_LONG >= NR_MSG_FRAG_IDS);
43 /* UAPI in filter.c depends on struct sk_msg_sg being first element. */
52 struct sock *sk_redir;
54 struct list_head list;
57 struct sk_psock_progs {
58 struct bpf_prog *msg_parser;
59 struct bpf_prog *stream_parser;
60 struct bpf_prog *stream_verdict;
61 struct bpf_prog *skb_verdict;
64 enum sk_psock_state_bits {
68 struct sk_psock_link {
69 struct list_head list;
74 struct sk_psock_work_state {
82 struct sock *sk_redir;
87 struct sk_psock_progs progs;
88 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
89 struct strparser strp;
91 struct sk_buff_head ingress_skb;
92 struct list_head ingress_msg;
93 spinlock_t ingress_lock;
95 struct list_head link;
98 void (*saved_unhash)(struct sock *sk);
99 void (*saved_close)(struct sock *sk, long timeout);
100 void (*saved_write_space)(struct sock *sk);
101 void (*saved_data_ready)(struct sock *sk);
102 int (*psock_update_sk_prot)(struct sock *sk, bool restore);
103 struct proto *sk_proto;
104 struct mutex work_mutex;
105 struct sk_psock_work_state work_state;
106 struct work_struct work;
107 struct rcu_work rwork;
110 int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
111 int elem_first_coalesce);
112 int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
114 void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len);
115 int sk_msg_free(struct sock *sk, struct sk_msg *msg);
116 int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg);
117 void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes);
118 void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
121 void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes);
122 void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes);
124 int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
125 struct sk_msg *msg, u32 bytes);
126 int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
127 struct sk_msg *msg, u32 bytes);
128 int sk_msg_wait_data(struct sock *sk, struct sk_psock *psock, int flags,
129 long timeo, int *err);
130 int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
133 static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes)
135 WARN_ON(i == msg->sg.end && bytes);
138 static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes)
140 if (psock->apply_bytes) {
141 if (psock->apply_bytes < bytes)
142 psock->apply_bytes = 0;
144 psock->apply_bytes -= bytes;
148 static inline u32 sk_msg_iter_dist(u32 start, u32 end)
150 return end >= start ? end - start : end + (NR_MSG_FRAG_IDS - start);
153 #define sk_msg_iter_var_prev(var) \
156 var = NR_MSG_FRAG_IDS - 1; \
161 #define sk_msg_iter_var_next(var) \
164 if (var == NR_MSG_FRAG_IDS) \
168 #define sk_msg_iter_prev(msg, which) \
169 sk_msg_iter_var_prev(msg->sg.which)
171 #define sk_msg_iter_next(msg, which) \
172 sk_msg_iter_var_next(msg->sg.which)
174 static inline void sk_msg_clear_meta(struct sk_msg *msg)
176 memset(&msg->sg, 0, offsetofend(struct sk_msg_sg, copy));
179 static inline void sk_msg_init(struct sk_msg *msg)
181 BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != NR_MSG_FRAG_IDS);
182 memset(msg, 0, sizeof(*msg));
183 sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS);
186 static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
189 dst->sg.data[which] = src->sg.data[which];
190 dst->sg.data[which].length = size;
191 dst->sg.size += size;
192 src->sg.size -= size;
193 src->sg.data[which].length -= size;
194 src->sg.data[which].offset += size;
197 static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src)
199 memcpy(dst, src, sizeof(*src));
203 static inline bool sk_msg_full(const struct sk_msg *msg)
205 return sk_msg_iter_dist(msg->sg.start, msg->sg.end) == MAX_MSG_FRAGS;
208 static inline u32 sk_msg_elem_used(const struct sk_msg *msg)
210 return sk_msg_iter_dist(msg->sg.start, msg->sg.end);
213 static inline struct scatterlist *sk_msg_elem(struct sk_msg *msg, int which)
215 return &msg->sg.data[which];
218 static inline struct scatterlist sk_msg_elem_cpy(struct sk_msg *msg, int which)
220 return msg->sg.data[which];
223 static inline struct page *sk_msg_page(struct sk_msg *msg, int which)
225 return sg_page(sk_msg_elem(msg, which));
228 static inline bool sk_msg_to_ingress(const struct sk_msg *msg)
230 return msg->flags & BPF_F_INGRESS;
233 static inline void sk_msg_compute_data_pointers(struct sk_msg *msg)
235 struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start);
237 if (test_bit(msg->sg.start, &msg->sg.copy)) {
239 msg->data_end = NULL;
241 msg->data = sg_virt(sge);
242 msg->data_end = msg->data + sge->length;
246 static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
249 struct scatterlist *sge;
252 sge = sk_msg_elem(msg, msg->sg.end);
253 sg_set_page(sge, page, len, offset);
256 __set_bit(msg->sg.end, &msg->sg.copy);
258 sk_msg_iter_next(msg, end);
261 static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state)
265 __set_bit(i, &msg->sg.copy);
267 __clear_bit(i, &msg->sg.copy);
268 sk_msg_iter_var_next(i);
269 if (i == msg->sg.end)
274 static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start)
276 sk_msg_sg_copy(msg, start, true);
279 static inline void sk_msg_sg_copy_clear(struct sk_msg *msg, u32 start)
281 sk_msg_sg_copy(msg, start, false);
284 static inline struct sk_psock *sk_psock(const struct sock *sk)
286 return rcu_dereference_sk_user_data(sk);
289 static inline void sk_psock_queue_msg(struct sk_psock *psock,
292 spin_lock_bh(&psock->ingress_lock);
293 list_add_tail(&msg->list, &psock->ingress_msg);
294 spin_unlock_bh(&psock->ingress_lock);
297 static inline struct sk_msg *sk_psock_dequeue_msg(struct sk_psock *psock)
301 spin_lock_bh(&psock->ingress_lock);
302 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
304 list_del(&msg->list);
305 spin_unlock_bh(&psock->ingress_lock);
309 static inline struct sk_msg *sk_psock_peek_msg(struct sk_psock *psock)
313 spin_lock_bh(&psock->ingress_lock);
314 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
315 spin_unlock_bh(&psock->ingress_lock);
319 static inline struct sk_msg *sk_psock_next_msg(struct sk_psock *psock,
324 spin_lock_bh(&psock->ingress_lock);
325 if (list_is_last(&msg->list, &psock->ingress_msg))
328 ret = list_next_entry(msg, list);
329 spin_unlock_bh(&psock->ingress_lock);
333 static inline bool sk_psock_queue_empty(const struct sk_psock *psock)
335 return psock ? list_empty(&psock->ingress_msg) : true;
338 static inline void kfree_sk_msg(struct sk_msg *msg)
341 consume_skb(msg->skb);
345 static inline void sk_psock_report_error(struct sk_psock *psock, int err)
347 struct sock *sk = psock->sk;
350 sk->sk_error_report(sk);
353 struct sk_psock *sk_psock_init(struct sock *sk, int node);
354 void sk_psock_stop(struct sk_psock *psock, bool wait);
356 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
357 int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock);
358 void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock);
359 void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock);
361 static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
366 static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
370 static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
375 void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock);
376 void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock);
378 int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
381 static inline struct sk_psock_link *sk_psock_init_link(void)
383 return kzalloc(sizeof(struct sk_psock_link),
384 GFP_ATOMIC | __GFP_NOWARN);
387 static inline void sk_psock_free_link(struct sk_psock_link *link)
392 struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock);
394 static inline void sk_psock_cork_free(struct sk_psock *psock)
397 sk_msg_free(psock->sk, psock->cork);
403 static inline void sk_psock_restore_proto(struct sock *sk,
404 struct sk_psock *psock)
406 if (psock->psock_update_sk_prot)
407 psock->psock_update_sk_prot(sk, true);
410 static inline void sk_psock_set_state(struct sk_psock *psock,
411 enum sk_psock_state_bits bit)
413 set_bit(bit, &psock->state);
416 static inline void sk_psock_clear_state(struct sk_psock *psock,
417 enum sk_psock_state_bits bit)
419 clear_bit(bit, &psock->state);
422 static inline bool sk_psock_test_state(const struct sk_psock *psock,
423 enum sk_psock_state_bits bit)
425 return test_bit(bit, &psock->state);
428 static inline struct sk_psock *sk_psock_get(struct sock *sk)
430 struct sk_psock *psock;
433 psock = sk_psock(sk);
434 if (psock && !refcount_inc_not_zero(&psock->refcnt))
440 void sk_psock_drop(struct sock *sk, struct sk_psock *psock);
442 static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock)
444 if (refcount_dec_and_test(&psock->refcnt))
445 sk_psock_drop(sk, psock);
448 static inline void sk_psock_data_ready(struct sock *sk, struct sk_psock *psock)
450 if (psock->saved_data_ready)
451 psock->saved_data_ready(sk);
453 sk->sk_data_ready(sk);
456 static inline void psock_set_prog(struct bpf_prog **pprog,
457 struct bpf_prog *prog)
459 prog = xchg(pprog, prog);
464 static inline int psock_replace_prog(struct bpf_prog **pprog,
465 struct bpf_prog *prog,
466 struct bpf_prog *old)
468 if (cmpxchg(pprog, old, prog) != old)
477 static inline void psock_progs_drop(struct sk_psock_progs *progs)
479 psock_set_prog(&progs->msg_parser, NULL);
480 psock_set_prog(&progs->stream_parser, NULL);
481 psock_set_prog(&progs->stream_verdict, NULL);
482 psock_set_prog(&progs->skb_verdict, NULL);
485 int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb);
487 static inline bool sk_psock_strp_enabled(struct sk_psock *psock)
491 return !!psock->saved_data_ready;
494 #if IS_ENABLED(CONFIG_NET_SOCK_MSG)
496 /* We only have one bit so far. */
497 #define BPF_F_PTR_MASK ~(BPF_F_INGRESS)
499 static inline bool skb_bpf_ingress(const struct sk_buff *skb)
501 unsigned long sk_redir = skb->_sk_redir;
503 return sk_redir & BPF_F_INGRESS;
506 static inline void skb_bpf_set_ingress(struct sk_buff *skb)
508 skb->_sk_redir |= BPF_F_INGRESS;
511 static inline void skb_bpf_set_redir(struct sk_buff *skb, struct sock *sk_redir,
514 skb->_sk_redir = (unsigned long)sk_redir;
516 skb->_sk_redir |= BPF_F_INGRESS;
519 static inline struct sock *skb_bpf_redirect_fetch(const struct sk_buff *skb)
521 unsigned long sk_redir = skb->_sk_redir;
523 return (struct sock *)(sk_redir & BPF_F_PTR_MASK);
526 static inline void skb_bpf_redirect_clear(struct sk_buff *skb)
530 #endif /* CONFIG_NET_SOCK_MSG */
531 #endif /* _LINUX_SKMSG_H */