xref: /linux/net/smc/smc.h (revision b615b9c36cae0468491547206406a909a9a37f26)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  Definitions for the SMC module (socket related)
6  *
7  *  Copyright IBM Corp. 2016
8  *
9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
10  */
11 #ifndef __SMC_H
12 #define __SMC_H
13 
14 #include <linux/socket.h>
15 #include <linux/types.h>
16 #include <linux/compiler.h> /* __aligned */
17 #include <net/genetlink.h>
18 #include <net/sock.h>
19 
20 #include "smc_ib.h"
21 
22 #define SMC_V1		1		/* SMC version V1 */
23 #define SMC_V2		2		/* SMC version V2 */
24 
25 #define SMC_RELEASE_0 0
26 #define SMC_RELEASE_1 1
27 #define SMC_RELEASE	SMC_RELEASE_1 /* the latest release version */
28 
29 #define SMCPROTO_SMC		0	/* SMC protocol, IPv4 */
30 #define SMCPROTO_SMC6		1	/* SMC protocol, IPv6 */
31 
32 #define SMC_AUTOCORKING_DEFAULT_SIZE	0x10000	/* 64K by default */
33 
34 extern struct proto smc_proto;
35 extern struct proto smc_proto6;
36 
37 extern struct smc_hashinfo smc_v4_hashinfo;
38 extern struct smc_hashinfo smc_v6_hashinfo;
39 
40 int smc_hash_sk(struct sock *sk);
41 void smc_unhash_sk(struct sock *sk);
42 void smc_release_cb(struct sock *sk);
43 
44 int smc_release(struct socket *sock);
45 int smc_bind(struct socket *sock, struct sockaddr *uaddr,
46 	     int addr_len);
47 int smc_connect(struct socket *sock, struct sockaddr *addr,
48 		int alen, int flags);
49 int smc_accept(struct socket *sock, struct socket *new_sock,
50 	       struct proto_accept_arg *arg);
51 int smc_getname(struct socket *sock, struct sockaddr *addr,
52 		int peer);
53 __poll_t smc_poll(struct file *file, struct socket *sock,
54 		  poll_table *wait);
55 int smc_ioctl(struct socket *sock, unsigned int cmd,
56 	      unsigned long arg);
57 int smc_listen(struct socket *sock, int backlog);
58 int smc_shutdown(struct socket *sock, int how);
59 int smc_setsockopt(struct socket *sock, int level, int optname,
60 		   sockptr_t optval, unsigned int optlen);
61 int smc_getsockopt(struct socket *sock, int level, int optname,
62 		   char __user *optval, int __user *optlen);
63 int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len);
64 int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
65 		int flags);
66 ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
67 			struct pipe_inode_info *pipe, size_t len,
68 			unsigned int flags);
69 
70 /* smc sock initialization */
71 void smc_sk_init(struct net *net, struct sock *sk, int protocol);
72 /* clcsock initialization */
73 int smc_create_clcsk(struct net *net, struct sock *sk, int family);
74 
75 #ifdef ATOMIC64_INIT
76 #define KERNEL_HAS_ATOMIC64
77 #endif
78 
79 enum smc_state {		/* possible states of an SMC socket */
80 	SMC_ACTIVE	= 1,
81 	SMC_INIT	= 2,
82 	SMC_CLOSED	= 7,
83 	SMC_LISTEN	= 10,
84 	/* normal close */
85 	SMC_PEERCLOSEWAIT1	= 20,
86 	SMC_PEERCLOSEWAIT2	= 21,
87 	SMC_APPFINCLOSEWAIT	= 24,
88 	SMC_APPCLOSEWAIT1	= 22,
89 	SMC_APPCLOSEWAIT2	= 23,
90 	SMC_PEERFINCLOSEWAIT	= 25,
91 	/* abnormal close */
92 	SMC_PEERABORTWAIT	= 26,
93 	SMC_PROCESSABORT	= 27,
94 };
95 
96 enum smc_supplemental_features {
97 	SMC_SPF_EMULATED_ISM_DEV	= 0,
98 };
99 
100 #define SMC_FEATURE_MASK \
101 	(BIT(SMC_SPF_EMULATED_ISM_DEV))
102 
103 struct smc_link_group;
104 
105 struct smc_wr_rx_hdr {	/* common prefix part of LLC and CDC to demultiplex */
106 	union {
107 		u8 type;
108 #if defined(__BIG_ENDIAN_BITFIELD)
109 		struct {
110 			u8 llc_version:4,
111 			   llc_type:4;
112 		};
113 #elif defined(__LITTLE_ENDIAN_BITFIELD)
114 		struct {
115 			u8 llc_type:4,
116 			   llc_version:4;
117 		};
118 #endif
119 	};
120 } __aligned(1);
121 
122 struct smc_cdc_conn_state_flags {
123 #if defined(__BIG_ENDIAN_BITFIELD)
124 	u8	peer_done_writing : 1;	/* Sending done indicator */
125 	u8	peer_conn_closed : 1;	/* Peer connection closed indicator */
126 	u8	peer_conn_abort : 1;	/* Abnormal close indicator */
127 	u8	reserved : 5;
128 #elif defined(__LITTLE_ENDIAN_BITFIELD)
129 	u8	reserved : 5;
130 	u8	peer_conn_abort : 1;
131 	u8	peer_conn_closed : 1;
132 	u8	peer_done_writing : 1;
133 #endif
134 };
135 
136 struct smc_cdc_producer_flags {
137 #if defined(__BIG_ENDIAN_BITFIELD)
138 	u8	write_blocked : 1;	/* Writing Blocked, no rx buf space */
139 	u8	urg_data_pending : 1;	/* Urgent Data Pending */
140 	u8	urg_data_present : 1;	/* Urgent Data Present */
141 	u8	cons_curs_upd_req : 1;	/* cursor update requested */
142 	u8	failover_validation : 1;/* message replay due to failover */
143 	u8	reserved : 3;
144 #elif defined(__LITTLE_ENDIAN_BITFIELD)
145 	u8	reserved : 3;
146 	u8	failover_validation : 1;
147 	u8	cons_curs_upd_req : 1;
148 	u8	urg_data_present : 1;
149 	u8	urg_data_pending : 1;
150 	u8	write_blocked : 1;
151 #endif
152 };
153 
154 /* in host byte order */
155 union smc_host_cursor {	/* SMC cursor - an offset in an RMBE */
156 	struct {
157 		u16	reserved;
158 		u16	wrap;		/* window wrap sequence number */
159 		u32	count;		/* cursor (= offset) part */
160 	};
161 #ifdef KERNEL_HAS_ATOMIC64
162 	atomic64_t		acurs;	/* for atomic processing */
163 #else
164 	u64			acurs;	/* for atomic processing */
165 #endif
166 } __aligned(8);
167 
168 /* in host byte order, except for flag bitfields in network byte order */
169 struct smc_host_cdc_msg {		/* Connection Data Control message */
170 	struct smc_wr_rx_hdr		common; /* .type = 0xFE */
171 	u8				len;	/* length = 44 */
172 	u16				seqno;	/* connection seq # */
173 	u32				token;	/* alert_token */
174 	union smc_host_cursor		prod;		/* producer cursor */
175 	union smc_host_cursor		cons;		/* consumer cursor,
176 							 * piggy backed "ack"
177 							 */
178 	struct smc_cdc_producer_flags	prod_flags;	/* conn. tx/rx status */
179 	struct smc_cdc_conn_state_flags	conn_state_flags; /* peer conn. status*/
180 	u8				reserved[18];
181 } __aligned(8);
182 
183 enum smc_urg_state {
184 	SMC_URG_VALID	= 1,			/* data present */
185 	SMC_URG_NOTYET	= 2,			/* data pending */
186 	SMC_URG_READ	= 3,			/* data was already read */
187 };
188 
189 struct smc_mark_woken {
190 	bool woken;
191 	void *key;
192 	wait_queue_entry_t wait_entry;
193 };
194 
195 struct smc_connection {
196 	struct rb_node		alert_node;
197 	struct smc_link_group	*lgr;		/* link group of connection */
198 	struct smc_link		*lnk;		/* assigned SMC-R link */
199 	u32			alert_token_local; /* unique conn. id */
200 	u8			peer_rmbe_idx;	/* from tcp handshake */
201 	int			peer_rmbe_size;	/* size of peer rx buffer */
202 	atomic_t		peer_rmbe_space;/* remaining free bytes in peer
203 						 * rmbe
204 						 */
205 	int			rtoken_idx;	/* idx to peer RMB rkey/addr */
206 
207 	struct smc_buf_desc	*sndbuf_desc;	/* send buffer descriptor */
208 	struct smc_buf_desc	*rmb_desc;	/* RMBE descriptor */
209 	int                     rmbe_size_comp; /* compressed notation */
210 	int			rmbe_update_limit;
211 						/* lower limit for consumer
212 						 * cursor update
213 						 */
214 
215 	struct smc_host_cdc_msg	local_tx_ctrl;	/* host byte order staging
216 						 * buffer for CDC msg send
217 						 * .prod cf. TCP snd_nxt
218 						 * .cons cf. TCP sends ack
219 						 */
220 	union smc_host_cursor	local_tx_ctrl_fin;
221 						/* prod crsr - confirmed by peer
222 						 */
223 	union smc_host_cursor	tx_curs_prep;	/* tx - prepared data
224 						 * snd_max..wmem_alloc
225 						 */
226 	union smc_host_cursor	tx_curs_sent;	/* tx - sent data
227 						 * snd_nxt ?
228 						 */
229 	union smc_host_cursor	tx_curs_fin;	/* tx - confirmed by peer
230 						 * snd-wnd-begin ?
231 						 */
232 	atomic_t		sndbuf_space;	/* remaining space in sndbuf */
233 	u16			tx_cdc_seq;	/* sequence # for CDC send */
234 	u16			tx_cdc_seq_fin;	/* sequence # - tx completed */
235 	spinlock_t		send_lock;	/* protect wr_sends */
236 	atomic_t		cdc_pend_tx_wr; /* number of pending tx CDC wqe
237 						 * - inc when post wqe,
238 						 * - dec on polled tx cqe
239 						 */
240 	wait_queue_head_t	cdc_pend_tx_wq; /* wakeup on no cdc_pend_tx_wr*/
241 	struct delayed_work	tx_work;	/* retry of smc_cdc_msg_send */
242 	u32			tx_off;		/* base offset in peer rmb */
243 
244 	struct smc_host_cdc_msg	local_rx_ctrl;	/* filled during event_handl.
245 						 * .prod cf. TCP rcv_nxt
246 						 * .cons cf. TCP snd_una
247 						 */
248 	union smc_host_cursor	rx_curs_confirmed; /* confirmed to peer
249 						    * source of snd_una ?
250 						    */
251 	union smc_host_cursor	urg_curs;	/* points at urgent byte */
252 	enum smc_urg_state	urg_state;
253 	bool			urg_tx_pend;	/* urgent data staged */
254 	bool			urg_rx_skip_pend;
255 						/* indicate urgent oob data
256 						 * read, but previous regular
257 						 * data still pending
258 						 */
259 	char			urg_rx_byte;	/* urgent byte */
260 	bool			tx_in_release_sock;
261 						/* flush pending tx data in
262 						 * sock release_cb()
263 						 */
264 	atomic_t		bytes_to_rcv;	/* arrived data,
265 						 * not yet received
266 						 */
267 	atomic_t		splice_pending;	/* number of spliced bytes
268 						 * pending processing
269 						 */
270 #ifndef KERNEL_HAS_ATOMIC64
271 	spinlock_t		acurs_lock;	/* protect cursors */
272 #endif
273 	struct work_struct	close_work;	/* peer sent some closing */
274 	struct work_struct	abort_work;	/* abort the connection */
275 	struct tasklet_struct	rx_tsklet;	/* Receiver tasklet for SMC-D */
276 	u8			rx_off;		/* receive offset:
277 						 * 0 for SMC-R, 32 for SMC-D
278 						 */
279 	u64			peer_token;	/* SMC-D token of peer */
280 	u8			killed : 1;	/* abnormal termination */
281 	u8			freed : 1;	/* normal termiation */
282 	u8			out_of_sync : 1; /* out of sync with peer */
283 };
284 
285 struct smc_sock {				/* smc sock container */
286 	struct sock		sk;
287 #if IS_ENABLED(CONFIG_IPV6)
288 	struct ipv6_pinfo	*pinet6;
289 #endif
290 	struct socket		*clcsock;	/* internal tcp socket */
291 	void			(*clcsk_state_change)(struct sock *sk);
292 						/* original stat_change fct. */
293 	void			(*clcsk_data_ready)(struct sock *sk);
294 						/* original data_ready fct. */
295 	void			(*clcsk_write_space)(struct sock *sk);
296 						/* original write_space fct. */
297 	void			(*clcsk_error_report)(struct sock *sk);
298 						/* original error_report fct. */
299 	struct smc_connection	conn;		/* smc connection */
300 	struct smc_sock		*listen_smc;	/* listen parent */
301 	struct work_struct	connect_work;	/* handle non-blocking connect*/
302 	struct work_struct	tcp_listen_work;/* handle tcp socket accepts */
303 	struct work_struct	smc_listen_work;/* prepare new accept socket */
304 	struct list_head	accept_q;	/* sockets to be accepted */
305 	spinlock_t		accept_q_lock;	/* protects accept_q */
306 	bool			limit_smc_hs;	/* put constraint on handshake */
307 	bool			use_fallback;	/* fallback to tcp */
308 	int			fallback_rsn;	/* reason for fallback */
309 	u32			peer_diagnosis; /* decline reason from peer */
310 	atomic_t                queued_smc_hs;  /* queued smc handshakes */
311 	struct inet_connection_sock_af_ops		af_ops;
312 	const struct inet_connection_sock_af_ops	*ori_af_ops;
313 						/* original af ops */
314 	int			sockopt_defer_accept;
315 						/* sockopt TCP_DEFER_ACCEPT
316 						 * value
317 						 */
318 	u8			wait_close_tx_prepared : 1;
319 						/* shutdown wr or close
320 						 * started, waiting for unsent
321 						 * data to be sent
322 						 */
323 	u8			connect_nonblock : 1;
324 						/* non-blocking connect in
325 						 * flight
326 						 */
327 	struct mutex            clcsock_release_lock;
328 						/* protects clcsock of a listen
329 						 * socket
330 						 * */
331 };
332 
333 #define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
334 
335 static inline void smc_init_saved_callbacks(struct smc_sock *smc)
336 {
337 	smc->clcsk_state_change	= NULL;
338 	smc->clcsk_data_ready	= NULL;
339 	smc->clcsk_write_space	= NULL;
340 	smc->clcsk_error_report	= NULL;
341 }
342 
343 static inline struct smc_sock *smc_clcsock_user_data(const struct sock *clcsk)
344 {
345 	return (struct smc_sock *)
346 	       ((uintptr_t)clcsk->sk_user_data & ~SK_USER_DATA_NOCOPY);
347 }
348 
349 /* save target_cb in saved_cb, and replace target_cb with new_cb */
350 static inline void smc_clcsock_replace_cb(void (**target_cb)(struct sock *),
351 					  void (*new_cb)(struct sock *),
352 					  void (**saved_cb)(struct sock *))
353 {
354 	/* only save once */
355 	if (!*saved_cb)
356 		*saved_cb = *target_cb;
357 	*target_cb = new_cb;
358 }
359 
360 /* restore target_cb to saved_cb, and reset saved_cb to NULL */
361 static inline void smc_clcsock_restore_cb(void (**target_cb)(struct sock *),
362 					  void (**saved_cb)(struct sock *))
363 {
364 	if (!*saved_cb)
365 		return;
366 	*target_cb = *saved_cb;
367 	*saved_cb = NULL;
368 }
369 
370 extern struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
371 extern struct workqueue_struct	*smc_close_wq;	/* wq for close work */
372 
373 #define SMC_SYSTEMID_LEN		8
374 
375 extern u8	local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
376 
377 #define ntohll(x) be64_to_cpu(x)
378 #define htonll(x) cpu_to_be64(x)
379 
380 /* convert an u32 value into network byte order, store it into a 3 byte field */
381 static inline void hton24(u8 *net, u32 host)
382 {
383 	__be32 t;
384 
385 	t = cpu_to_be32(host);
386 	memcpy(net, ((u8 *)&t) + 1, 3);
387 }
388 
389 /* convert a received 3 byte field into host byte order*/
390 static inline u32 ntoh24(u8 *net)
391 {
392 	__be32 t = 0;
393 
394 	memcpy(((u8 *)&t) + 1, net, 3);
395 	return be32_to_cpu(t);
396 }
397 
398 #ifdef CONFIG_XFRM
399 static inline bool using_ipsec(struct smc_sock *smc)
400 {
401 	return (smc->clcsock->sk->sk_policy[0] ||
402 		smc->clcsock->sk->sk_policy[1]) ? true : false;
403 }
404 #else
405 static inline bool using_ipsec(struct smc_sock *smc)
406 {
407 	return false;
408 }
409 #endif
410 
411 struct smc_gidlist;
412 
413 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
414 void smc_close_non_accepted(struct sock *sk);
415 void smc_fill_gid_list(struct smc_link_group *lgr,
416 		       struct smc_gidlist *gidlist,
417 		       struct smc_ib_device *known_dev, u8 *known_gid);
418 
419 /* smc handshake limitation interface for netlink  */
420 int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb);
421 int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
422 int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info);
423 
424 static inline void smc_sock_set_flag(struct sock *sk, enum sock_flags flag)
425 {
426 	set_bit(flag, &sk->sk_flags);
427 }
428 
429 #endif	/* __SMC_H */
430