include/linux/sunrpc/svc_xprt.h

   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_ctxt)(struct svc_xprt *xprt, void *ctxt);
  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 lwq_node         xpt_ready;
  58         unsigned long           xpt_flags;
  59
  60         struct svc_serv         *xpt_server;    /* service for transport */
  61         atomic_t                xpt_reserved;   /* space on outq that is rsvd */
  62         atomic_t                xpt_nr_rqsts;   /* Number of requests */
  63         struct mutex            xpt_mutex;      /* to serialize sending data */
  64         spinlock_t              xpt_lock;       /* protects sk_deferred
  65                                                  * and xpt_auth_cache */
  66         void                    *xpt_auth_cache;/* auth cache */
  67         struct list_head        xpt_deferred;   /* deferred requests that need
  68                                                  * to be revisted */
  69         struct sockaddr_storage xpt_local;      /* local address */
  70         size_t                  xpt_locallen;   /* length of address */
  71         struct sockaddr_storage xpt_remote;     /* remote peer's address */
  72         size_t                  xpt_remotelen;  /* length of address */
  73         char                    xpt_remotebuf[INET6_ADDRSTRLEN + 10];
  74         struct list_head        xpt_users;      /* callbacks on free */
  75
  76         struct net              *xpt_net;
  77         netns_tracker           ns_tracker;
  78         const struct cred       *xpt_cred;
  79         struct rpc_xprt         *xpt_bc_xprt;   /* NFSv4.1 backchannel */
  80         struct rpc_xprt_switch  *xpt_bc_xps;    /* NFSv4.1 backchannel */
  81 };
  82
  83 /* flag bits for xpt_flags */
  84 enum {
  85         XPT_BUSY,               /* enqueued/receiving */
  86         XPT_CONN,               /* conn pending */
  87         XPT_CLOSE,              /* dead or dying */
  88         XPT_DATA,               /* data pending */
  89         XPT_TEMP,               /* connected transport */
  90         XPT_DEAD,               /* transport closed */
  91         XPT_CHNGBUF,            /* need to change snd/rcv buf sizes */
  92         XPT_DEFERRED,           /* deferred request pending */
  93         XPT_OLD,                /* used for xprt aging mark+sweep */
  94         XPT_LISTENER,           /* listening endpoint */
  95         XPT_CACHE_AUTH,         /* cache auth info */
  96         XPT_LOCAL,              /* connection from loopback interface */
  97         XPT_KILL_TEMP,          /* call xpo_kill_temp_xprt before closing */
  98         XPT_CONG_CTRL,          /* has congestion control */
  99         XPT_HANDSHAKE,          /* xprt requests a handshake */
 100         XPT_TLS_SESSION,        /* transport-layer security established */
 101         XPT_PEER_AUTH,          /* peer has been authenticated */
 102         XPT_PEER_VALID,         /* peer has presented a filehandle that
 103                                  * it has access to.  It is NOT counted
 104                                  * in ->sv_tmpcnt.
 105                                  */
 106 };
 107
 108 /*
 109  * Maximum number of "tmp" connections - those without XPT_PEER_VALID -
 110  * permitted on any service.
 111  */
 112 #define XPT_MAX_TMP_CONN        64
 113
 114 static inline void svc_xprt_set_valid(struct svc_xprt *xpt)
 115 {
 116         if (test_bit(XPT_TEMP, &xpt->xpt_flags) &&
 117             !test_and_set_bit(XPT_PEER_VALID, &xpt->xpt_flags)) {
 118                 struct svc_serv *serv = xpt->xpt_server;
 119
 120                 spin_lock(&serv->sv_lock);
 121                 serv->sv_tmpcnt -= 1;
 122                 spin_unlock(&serv->sv_lock);
 123         }
 124 }
 125
 126 static inline void unregister_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u)
 127 {
 128         spin_lock(&xpt->xpt_lock);
 129         list_del_init(&u->list);
 130         spin_unlock(&xpt->xpt_lock);
 131 }
 132
 133 static inline int register_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u)
 134 {
 135         spin_lock(&xpt->xpt_lock);
 136         if (test_bit(XPT_CLOSE, &xpt->xpt_flags)) {
 137                 /*
 138                  * The connection is about to be deleted soon (or,
 139                  * worse, may already be deleted--in which case we've
 140                  * already notified the xpt_users).
 141                  */
 142                 spin_unlock(&xpt->xpt_lock);
 143                 return -ENOTCONN;
 144         }
 145         list_add(&u->list, &xpt->xpt_users);
 146         spin_unlock(&xpt->xpt_lock);
 147         return 0;
 148 }
 149
 150 static inline bool svc_xprt_is_dead(const struct svc_xprt *xprt)
 151 {
 152         return (test_bit(XPT_DEAD, &xprt->xpt_flags) != 0) ||
 153                 (test_bit(XPT_CLOSE, &xprt->xpt_flags) != 0);
 154 }
 155
 156 int     svc_reg_xprt_class(struct svc_xprt_class *);
 157 void    svc_unreg_xprt_class(struct svc_xprt_class *);
 158 void    svc_xprt_init(struct net *, struct svc_xprt_class *, struct svc_xprt *,
 159                       struct svc_serv *);
 160 int     svc_xprt_create_from_sa(struct svc_serv *serv, const char *xprt_name,
 161                                 struct net *net, struct sockaddr *sap,
 162                                 int flags, const struct cred *cred);
 163 int     svc_xprt_create(struct svc_serv *serv, const char *xprt_name,
 164                         struct net *net, const int family,
 165                         const unsigned short port, int flags,
 166                         const struct cred *cred);
 167 void    svc_xprt_destroy_all(struct svc_serv *serv, struct net *net);
 168 void    svc_xprt_received(struct svc_xprt *xprt);
 169 void    svc_xprt_enqueue(struct svc_xprt *xprt);
 170 void    svc_xprt_put(struct svc_xprt *xprt);
 171 void    svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt);
 172 void    svc_xprt_close(struct svc_xprt *xprt);
 173 int     svc_port_is_privileged(struct sockaddr *sin);
 174 int     svc_print_xprts(char *buf, int maxlen);
 175 struct svc_xprt *svc_find_listener(struct svc_serv *serv, const char *xcl_name,
 176                                    struct net *net, const struct sockaddr *sa);
 177 struct  svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
 178                         struct net *net, const sa_family_t af,
 179                         const unsigned short port);
 180 int     svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen);
 181 void    svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *xprt);
 182 void    svc_age_temp_xprts_now(struct svc_serv *, struct sockaddr *);
 183 void    svc_xprt_deferred_close(struct svc_xprt *xprt);
 184
 185 static inline void svc_xprt_get(struct svc_xprt *xprt)
 186 {
 187         kref_get(&xprt->xpt_ref);
 188 }
 189 static inline void svc_xprt_set_local(struct svc_xprt *xprt,
 190                                       const struct sockaddr *sa,
 191                                       const size_t salen)
 192 {
 193         memcpy(&xprt->xpt_local, sa, salen);
 194         xprt->xpt_locallen = salen;
 195 }
 196 static inline void svc_xprt_set_remote(struct svc_xprt *xprt,
 197                                        const struct sockaddr *sa,
 198                                        const size_t salen)
 199 {
 200         memcpy(&xprt->xpt_remote, sa, salen);
 201         xprt->xpt_remotelen = salen;
 202         snprintf(xprt->xpt_remotebuf, sizeof(xprt->xpt_remotebuf) - 1,
 203                  "%pISpc", sa);
 204 }
 205
 206 static inline unsigned short svc_addr_port(const struct sockaddr *sa)
 207 {
 208         const struct sockaddr_in *sin = (const struct sockaddr_in *)sa;
 209         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sa;
 210
 211         switch (sa->sa_family) {
 212         case AF_INET:
 213                 return ntohs(sin->sin_port);
 214         case AF_INET6:
 215                 return ntohs(sin6->sin6_port);
 216         }
 217
 218         return 0;
 219 }
 220
 221 static inline size_t svc_addr_len(const struct sockaddr *sa)
 222 {
 223         switch (sa->sa_family) {
 224         case AF_INET:
 225                 return sizeof(struct sockaddr_in);
 226         case AF_INET6:
 227                 return sizeof(struct sockaddr_in6);
 228         }
 229         BUG();
 230 }
 231
 232 static inline unsigned short svc_xprt_local_port(const struct svc_xprt *xprt)
 233 {
 234         return svc_addr_port((const struct sockaddr *)&xprt->xpt_local);
 235 }
 236
 237 static inline unsigned short svc_xprt_remote_port(const struct svc_xprt *xprt)
 238 {
 239         return svc_addr_port((const struct sockaddr *)&xprt->xpt_remote);
 240 }
 241
 242 static inline char *__svc_print_addr(const struct sockaddr *addr,
 243                                      char *buf, const size_t len)
 244 {
 245         const struct sockaddr_in *sin = (const struct sockaddr_in *)addr;
 246         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)addr;
 247
 248         switch (addr->sa_family) {
 249         case AF_INET:
 250                 snprintf(buf, len, "%pI4, port=%u", &sin->sin_addr,
 251                         ntohs(sin->sin_port));
 252                 break;
 253
 254         case AF_INET6:
 255                 snprintf(buf, len, "%pI6, port=%u",
 256                          &sin6->sin6_addr,
 257                         ntohs(sin6->sin6_port));
 258                 break;
 259
 260         default:
 261                 snprintf(buf, len, "unknown address type: %d", addr->sa_family);
 262                 break;
 263         }
 264
 265         return buf;
 266 }
 267 #endif /* SUNRPC_SVC_XPRT_H */