xref: /linux-6.15/include/linux/sunrpc/svc_xprt.h (revision 564f7dfd)
1 /*
2  * linux/include/linux/sunrpc/svc_xprt.h
3  *
4  * RPC server transport I/O
5  */
6 
7 #ifndef SUNRPC_SVC_XPRT_H
8 #define SUNRPC_SVC_XPRT_H
9 
10 #include <linux/sunrpc/svc.h>
11 
12 struct module;
13 
14 struct svc_xprt_ops {
15 	struct svc_xprt	*(*xpo_create)(struct svc_serv *,
16 				       struct net *net,
17 				       struct sockaddr *, int,
18 				       int);
19 	struct svc_xprt	*(*xpo_accept)(struct svc_xprt *);
20 	int		(*xpo_has_wspace)(struct svc_xprt *);
21 	int		(*xpo_recvfrom)(struct svc_rqst *);
22 	void		(*xpo_prep_reply_hdr)(struct svc_rqst *);
23 	int		(*xpo_sendto)(struct svc_rqst *);
24 	void		(*xpo_release_rqst)(struct svc_rqst *);
25 	void		(*xpo_detach)(struct svc_xprt *);
26 	void		(*xpo_free)(struct svc_xprt *);
27 	int		(*xpo_secure_port)(struct svc_rqst *);
28 	void		(*xpo_kill_temp_xprt)(struct svc_xprt *);
29 };
30 
31 struct svc_xprt_class {
32 	const char		*xcl_name;
33 	struct module		*xcl_owner;
34 	struct svc_xprt_ops	*xcl_ops;
35 	struct list_head	xcl_list;
36 	u32			xcl_max_payload;
37 	int			xcl_ident;
38 };
39 
40 /*
41  * This is embedded in an object that wants a callback before deleting
42  * an xprt; intended for use by NFSv4.1, which needs to know when a
43  * client's tcp connection (and hence possibly a backchannel) goes away.
44  */
45 struct svc_xpt_user {
46 	struct list_head list;
47 	void (*callback)(struct svc_xpt_user *);
48 };
49 
50 struct svc_xprt {
51 	struct svc_xprt_class	*xpt_class;
52 	struct svc_xprt_ops	*xpt_ops;
53 	struct kref		xpt_ref;
54 	struct list_head	xpt_list;
55 	struct list_head	xpt_ready;
56 	unsigned long		xpt_flags;
57 #define	XPT_BUSY	0		/* enqueued/receiving */
58 #define	XPT_CONN	1		/* conn pending */
59 #define	XPT_CLOSE	2		/* dead or dying */
60 #define	XPT_DATA	3		/* data pending */
61 #define	XPT_TEMP	4		/* connected transport */
62 #define	XPT_DEAD	6		/* transport closed */
63 #define	XPT_CHNGBUF	7		/* need to change snd/rcv buf sizes */
64 #define	XPT_DEFERRED	8		/* deferred request pending */
65 #define	XPT_OLD		9		/* used for xprt aging mark+sweep */
66 #define XPT_LISTENER	10		/* listening endpoint */
67 #define XPT_CACHE_AUTH	11		/* cache auth info */
68 #define XPT_LOCAL	12		/* connection from loopback interface */
69 #define XPT_KILL_TEMP   13		/* call xpo_kill_temp_xprt before closing */
70 #define XPT_CONG_CTRL	14		/* has congestion control */
71 
72 	struct svc_serv		*xpt_server;	/* service for transport */
73 	atomic_t    	    	xpt_reserved;	/* space on outq that is rsvd */
74 	atomic_t		xpt_nr_rqsts;	/* Number of requests */
75 	struct mutex		xpt_mutex;	/* to serialize sending data */
76 	spinlock_t		xpt_lock;	/* protects sk_deferred
77 						 * and xpt_auth_cache */
78 	void			*xpt_auth_cache;/* auth cache */
79 	struct list_head	xpt_deferred;	/* deferred requests that need
80 						 * to be revisted */
81 	struct sockaddr_storage	xpt_local;	/* local address */
82 	size_t			xpt_locallen;	/* length of address */
83 	struct sockaddr_storage	xpt_remote;	/* remote peer's address */
84 	size_t			xpt_remotelen;	/* length of address */
85 	struct rpc_wait_queue	xpt_bc_pending;	/* backchannel wait queue */
86 	struct list_head	xpt_users;	/* callbacks on free */
87 
88 	struct net		*xpt_net;
89 	struct rpc_xprt		*xpt_bc_xprt;	/* NFSv4.1 backchannel */
90 	struct rpc_xprt_switch	*xpt_bc_xps;	/* NFSv4.1 backchannel */
91 };
92 
93 static inline void unregister_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u)
94 {
95 	spin_lock(&xpt->xpt_lock);
96 	list_del_init(&u->list);
97 	spin_unlock(&xpt->xpt_lock);
98 }
99 
100 static inline int register_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u)
101 {
102 	spin_lock(&xpt->xpt_lock);
103 	if (test_bit(XPT_CLOSE, &xpt->xpt_flags)) {
104 		/*
105 		 * The connection is about to be deleted soon (or,
106 		 * worse, may already be deleted--in which case we've
107 		 * already notified the xpt_users).
108 		 */
109 		spin_unlock(&xpt->xpt_lock);
110 		return -ENOTCONN;
111 	}
112 	list_add(&u->list, &xpt->xpt_users);
113 	spin_unlock(&xpt->xpt_lock);
114 	return 0;
115 }
116 
117 int	svc_reg_xprt_class(struct svc_xprt_class *);
118 void	svc_unreg_xprt_class(struct svc_xprt_class *);
119 void	svc_xprt_init(struct net *, struct svc_xprt_class *, struct svc_xprt *,
120 		      struct svc_serv *);
121 int	svc_create_xprt(struct svc_serv *, const char *, struct net *,
122 			const int, const unsigned short, int);
123 void	svc_xprt_do_enqueue(struct svc_xprt *xprt);
124 void	svc_xprt_enqueue(struct svc_xprt *xprt);
125 void	svc_xprt_put(struct svc_xprt *xprt);
126 void	svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt);
127 void	svc_close_xprt(struct svc_xprt *xprt);
128 int	svc_port_is_privileged(struct sockaddr *sin);
129 int	svc_print_xprts(char *buf, int maxlen);
130 struct	svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
131 			struct net *net, const sa_family_t af,
132 			const unsigned short port);
133 int	svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen);
134 void	svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *xprt);
135 void	svc_age_temp_xprts_now(struct svc_serv *, struct sockaddr *);
136 
137 static inline void svc_xprt_get(struct svc_xprt *xprt)
138 {
139 	kref_get(&xprt->xpt_ref);
140 }
141 static inline void svc_xprt_set_local(struct svc_xprt *xprt,
142 				      const struct sockaddr *sa,
143 				      const size_t salen)
144 {
145 	memcpy(&xprt->xpt_local, sa, salen);
146 	xprt->xpt_locallen = salen;
147 }
148 static inline void svc_xprt_set_remote(struct svc_xprt *xprt,
149 				       const struct sockaddr *sa,
150 				       const size_t salen)
151 {
152 	memcpy(&xprt->xpt_remote, sa, salen);
153 	xprt->xpt_remotelen = salen;
154 }
155 static inline unsigned short svc_addr_port(const struct sockaddr *sa)
156 {
157 	const struct sockaddr_in *sin = (const struct sockaddr_in *)sa;
158 	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sa;
159 
160 	switch (sa->sa_family) {
161 	case AF_INET:
162 		return ntohs(sin->sin_port);
163 	case AF_INET6:
164 		return ntohs(sin6->sin6_port);
165 	}
166 
167 	return 0;
168 }
169 
170 static inline size_t svc_addr_len(const struct sockaddr *sa)
171 {
172 	switch (sa->sa_family) {
173 	case AF_INET:
174 		return sizeof(struct sockaddr_in);
175 	case AF_INET6:
176 		return sizeof(struct sockaddr_in6);
177 	}
178 	BUG();
179 }
180 
181 static inline unsigned short svc_xprt_local_port(const struct svc_xprt *xprt)
182 {
183 	return svc_addr_port((const struct sockaddr *)&xprt->xpt_local);
184 }
185 
186 static inline unsigned short svc_xprt_remote_port(const struct svc_xprt *xprt)
187 {
188 	return svc_addr_port((const struct sockaddr *)&xprt->xpt_remote);
189 }
190 
191 static inline char *__svc_print_addr(const struct sockaddr *addr,
192 				     char *buf, const size_t len)
193 {
194 	const struct sockaddr_in *sin = (const struct sockaddr_in *)addr;
195 	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)addr;
196 
197 	switch (addr->sa_family) {
198 	case AF_INET:
199 		snprintf(buf, len, "%pI4, port=%u", &sin->sin_addr,
200 			ntohs(sin->sin_port));
201 		break;
202 
203 	case AF_INET6:
204 		snprintf(buf, len, "%pI6, port=%u",
205 			 &sin6->sin6_addr,
206 			ntohs(sin6->sin6_port));
207 		break;
208 
209 	default:
210 		snprintf(buf, len, "unknown address type: %d", addr->sa_family);
211 		break;
212 	}
213 
214 	return buf;
215 }
216 #endif /* SUNRPC_SVC_XPRT_H */
217