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