xref: /openbmc/linux/include/linux/sunrpc/svc_xprt.h (revision c1b2093d)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * linux/include/linux/sunrpc/svc_xprt.h
4  *
5  * RPC server transport I/O
6  */
7 
8 #ifndef SUNRPC_SVC_XPRT_H
9 #define SUNRPC_SVC_XPRT_H
10 
11 #include <linux/sunrpc/svc.h>
12 
13 struct module;
14 
15 struct svc_xprt_ops {
16 	struct svc_xprt	*(*xpo_create)(struct svc_serv *,
17 				       struct net *net,
18 				       struct sockaddr *, int,
19 				       int);
20 	struct svc_xprt	*(*xpo_accept)(struct svc_xprt *);
21 	int		(*xpo_has_wspace)(struct svc_xprt *);
22 	int		(*xpo_recvfrom)(struct svc_rqst *);
23 	int		(*xpo_sendto)(struct svc_rqst *);
24 	int		(*xpo_result_payload)(struct svc_rqst *, unsigned int,
25 					      unsigned int);
26 	void		(*xpo_release_rqst)(struct svc_rqst *);
27 	void		(*xpo_detach)(struct svc_xprt *);
28 	void		(*xpo_free)(struct svc_xprt *);
29 	void		(*xpo_kill_temp_xprt)(struct svc_xprt *);
30 	void		(*xpo_handshake)(struct svc_xprt *xprt);
31 };
32 
33 struct svc_xprt_class {
34 	const char		*xcl_name;
35 	struct module		*xcl_owner;
36 	const struct svc_xprt_ops *xcl_ops;
37 	struct list_head	xcl_list;
38 	u32			xcl_max_payload;
39 	int			xcl_ident;
40 };
41 
42 /*
43  * This is embedded in an object that wants a callback before deleting
44  * an xprt; intended for use by NFSv4.1, which needs to know when a
45  * client's tcp connection (and hence possibly a backchannel) goes away.
46  */
47 struct svc_xpt_user {
48 	struct list_head list;
49 	void (*callback)(struct svc_xpt_user *);
50 };
51 
52 struct svc_xprt {
53 	struct svc_xprt_class	*xpt_class;
54 	const struct svc_xprt_ops *xpt_ops;
55 	struct kref		xpt_ref;
56 	struct list_head	xpt_list;
57 	struct list_head	xpt_ready;
58 	unsigned long		xpt_flags;
59 #define	XPT_BUSY	0		/* enqueued/receiving */
60 #define	XPT_CONN	1		/* conn pending */
61 #define	XPT_CLOSE	2		/* dead or dying */
62 #define	XPT_DATA	3		/* data pending */
63 #define	XPT_TEMP	4		/* connected transport */
64 #define	XPT_DEAD	6		/* transport closed */
65 #define	XPT_CHNGBUF	7		/* need to change snd/rcv buf sizes */
66 #define	XPT_DEFERRED	8		/* deferred request pending */
67 #define	XPT_OLD		9		/* used for xprt aging mark+sweep */
68 #define XPT_LISTENER	10		/* listening endpoint */
69 #define XPT_CACHE_AUTH	11		/* cache auth info */
70 #define XPT_LOCAL	12		/* connection from loopback interface */
71 #define XPT_KILL_TEMP   13		/* call xpo_kill_temp_xprt before closing */
72 #define XPT_CONG_CTRL	14		/* has congestion control */
73 #define XPT_HANDSHAKE	15		/* xprt requests a handshake */
74 #define XPT_TLS_SESSION	16		/* transport-layer security established */
75 #define XPT_PEER_AUTH	17		/* peer has been authenticated */
76 
77 	struct svc_serv		*xpt_server;	/* service for transport */
78 	atomic_t    	    	xpt_reserved;	/* space on outq that is rsvd */
79 	atomic_t		xpt_nr_rqsts;	/* Number of requests */
80 	struct mutex		xpt_mutex;	/* to serialize sending data */
81 	spinlock_t		xpt_lock;	/* protects sk_deferred
82 						 * and xpt_auth_cache */
83 	void			*xpt_auth_cache;/* auth cache */
84 	struct list_head	xpt_deferred;	/* deferred requests that need
85 						 * to be revisted */
86 	struct sockaddr_storage	xpt_local;	/* local address */
87 	size_t			xpt_locallen;	/* length of address */
88 	struct sockaddr_storage	xpt_remote;	/* remote peer's address */
89 	size_t			xpt_remotelen;	/* length of address */
90 	char			xpt_remotebuf[INET6_ADDRSTRLEN + 10];
91 	struct list_head	xpt_users;	/* callbacks on free */
92 
93 	struct net		*xpt_net;
94 	netns_tracker		ns_tracker;
95 	const struct cred	*xpt_cred;
96 	struct rpc_xprt		*xpt_bc_xprt;	/* NFSv4.1 backchannel */
97 	struct rpc_xprt_switch	*xpt_bc_xps;	/* NFSv4.1 backchannel */
98 };
99 
100 static inline void unregister_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u)
101 {
102 	spin_lock(&xpt->xpt_lock);
103 	list_del_init(&u->list);
104 	spin_unlock(&xpt->xpt_lock);
105 }
106 
107 static inline int register_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u)
108 {
109 	spin_lock(&xpt->xpt_lock);
110 	if (test_bit(XPT_CLOSE, &xpt->xpt_flags)) {
111 		/*
112 		 * The connection is about to be deleted soon (or,
113 		 * worse, may already be deleted--in which case we've
114 		 * already notified the xpt_users).
115 		 */
116 		spin_unlock(&xpt->xpt_lock);
117 		return -ENOTCONN;
118 	}
119 	list_add(&u->list, &xpt->xpt_users);
120 	spin_unlock(&xpt->xpt_lock);
121 	return 0;
122 }
123 
124 static inline bool svc_xprt_is_dead(const struct svc_xprt *xprt)
125 {
126 	return (test_bit(XPT_DEAD, &xprt->xpt_flags) != 0) ||
127 		(test_bit(XPT_CLOSE, &xprt->xpt_flags) != 0);
128 }
129 
130 int	svc_reg_xprt_class(struct svc_xprt_class *);
131 void	svc_unreg_xprt_class(struct svc_xprt_class *);
132 void	svc_xprt_init(struct net *, struct svc_xprt_class *, struct svc_xprt *,
133 		      struct svc_serv *);
134 int	svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
135 			struct net *net, const int family,
136 			const unsigned short port, int flags,
137 			const struct cred *cred);
138 void	svc_xprt_destroy_all(struct svc_serv *serv, struct net *net);
139 void	svc_xprt_received(struct svc_xprt *xprt);
140 void	svc_xprt_enqueue(struct svc_xprt *xprt);
141 void	svc_xprt_put(struct svc_xprt *xprt);
142 void	svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt);
143 void	svc_xprt_close(struct svc_xprt *xprt);
144 int	svc_port_is_privileged(struct sockaddr *sin);
145 int	svc_print_xprts(char *buf, int maxlen);
146 struct	svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
147 			struct net *net, const sa_family_t af,
148 			const unsigned short port);
149 int	svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen);
150 void	svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *xprt);
151 void	svc_age_temp_xprts_now(struct svc_serv *, struct sockaddr *);
152 void	svc_xprt_deferred_close(struct svc_xprt *xprt);
153 
154 static inline void svc_xprt_get(struct svc_xprt *xprt)
155 {
156 	kref_get(&xprt->xpt_ref);
157 }
158 static inline void svc_xprt_set_local(struct svc_xprt *xprt,
159 				      const struct sockaddr *sa,
160 				      const size_t salen)
161 {
162 	memcpy(&xprt->xpt_local, sa, salen);
163 	xprt->xpt_locallen = salen;
164 }
165 static inline void svc_xprt_set_remote(struct svc_xprt *xprt,
166 				       const struct sockaddr *sa,
167 				       const size_t salen)
168 {
169 	memcpy(&xprt->xpt_remote, sa, salen);
170 	xprt->xpt_remotelen = salen;
171 	snprintf(xprt->xpt_remotebuf, sizeof(xprt->xpt_remotebuf) - 1,
172 		 "%pISpc", sa);
173 }
174 
175 static inline unsigned short svc_addr_port(const struct sockaddr *sa)
176 {
177 	const struct sockaddr_in *sin = (const struct sockaddr_in *)sa;
178 	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sa;
179 
180 	switch (sa->sa_family) {
181 	case AF_INET:
182 		return ntohs(sin->sin_port);
183 	case AF_INET6:
184 		return ntohs(sin6->sin6_port);
185 	}
186 
187 	return 0;
188 }
189 
190 static inline size_t svc_addr_len(const struct sockaddr *sa)
191 {
192 	switch (sa->sa_family) {
193 	case AF_INET:
194 		return sizeof(struct sockaddr_in);
195 	case AF_INET6:
196 		return sizeof(struct sockaddr_in6);
197 	}
198 	BUG();
199 }
200 
201 static inline unsigned short svc_xprt_local_port(const struct svc_xprt *xprt)
202 {
203 	return svc_addr_port((const struct sockaddr *)&xprt->xpt_local);
204 }
205 
206 static inline unsigned short svc_xprt_remote_port(const struct svc_xprt *xprt)
207 {
208 	return svc_addr_port((const struct sockaddr *)&xprt->xpt_remote);
209 }
210 
211 static inline char *__svc_print_addr(const struct sockaddr *addr,
212 				     char *buf, const size_t len)
213 {
214 	const struct sockaddr_in *sin = (const struct sockaddr_in *)addr;
215 	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)addr;
216 
217 	switch (addr->sa_family) {
218 	case AF_INET:
219 		snprintf(buf, len, "%pI4, port=%u", &sin->sin_addr,
220 			ntohs(sin->sin_port));
221 		break;
222 
223 	case AF_INET6:
224 		snprintf(buf, len, "%pI6, port=%u",
225 			 &sin6->sin6_addr,
226 			ntohs(sin6->sin6_port));
227 		break;
228 
229 	default:
230 		snprintf(buf, len, "unknown address type: %d", addr->sa_family);
231 		break;
232 	}
233 
234 	return buf;
235 }
236 #endif /* SUNRPC_SVC_XPRT_H */
237