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31 * @(#)unpcb.h 8.1 (Berkeley) 6/2/93
38 typedef uint64_t unp_gen_t;
40 #if defined(_KERNEL) || defined(_WANT_UNPCB)
41 #include <sys/queue.h>
42 #include <sys/ucred.h>
45 * Protocol control block for an active
46 * instance of a UNIX internal protocol.
48 * A socket may be associated with a vnode in the
49 * filesystem. If so, the unp_vnode pointer holds
50 * a reference count to this vnode, which should be irele'd
51 * when the socket goes away.
53 * A socket may be connected to another socket, in which
54 * case the control block of the socket to which it is connected
55 * is given by unp_conn.
57 * A socket may be referenced by a number of sockets (e.g. several
58 * sockets may be connected to a datagram socket.) These sockets
59 * are in a linked list starting with unp_refs, linked through
60 * unp_nextref and null-terminated. Note that a socket may be referenced
61 * by a number of other sockets and may also reference a socket (not
62 * necessarily one which is referencing it). This generates
63 * the need for unp_refs and unp_nextref to be separate fields.
65 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt
66 * so that changes in the sockbuf may be computed to modify
67 * back pressure on the sender accordingly.
69 LIST_HEAD(unp_head, unpcb);
72 LIST_ENTRY(unpcb) unp_link; /* glue on list of all PCBs */
73 struct socket *unp_socket; /* pointer back to socket */
74 struct file *unp_file; /* back-pointer to file for gc. */
75 struct vnode *unp_vnode; /* if associated with file */
76 ino_t unp_ino; /* fake inode number */
77 struct unpcb *unp_conn; /* control block of connected socket */
78 struct unp_head unp_refs; /* referencing socket linked list */
79 LIST_ENTRY(unpcb) unp_reflink; /* link in unp_refs list */
80 struct sockaddr_un *unp_addr; /* bound address of socket */
81 unp_gen_t unp_gencnt; /* generation count of this instance */
82 short unp_flags; /* flags */
83 short unp_gcflag; /* Garbage collector flags. */
84 struct xucred unp_peercred; /* peer credentials, if applicable */
86 u_int unp_msgcount; /* references from message queue */
87 struct mtx unp_mtx; /* mutex */
93 * UNP_HAVEPC - indicates that the unp_peercred member is filled in
94 * and is really the credentials of the connected peer. This is used
95 * to determine whether the contents should be sent to the user or
98 #define UNP_HAVEPC 0x001
99 #define UNP_WANTCRED 0x004 /* credentials wanted */
100 #define UNP_CONNWAIT 0x008 /* connect blocks until accepted */
103 * These flags are used to handle non-atomicity in connect() and bind()
104 * operations on a socket: in particular, to avoid races between multiple
105 * threads or processes operating simultaneously on the same socket.
107 #define UNP_CONNECTING 0x010 /* Currently connecting. */
108 #define UNP_BINDING 0x020 /* Currently binding. */
109 #define UNP_NASCENT 0x040 /* Newborn child socket. */
112 * Flags in unp_gcflag.
114 #define UNPGC_REF 0x1 /* unpcb has external ref. */
115 #define UNPGC_DEAD 0x2 /* unpcb might be dead. */
116 #define UNPGC_SCANNED 0x4 /* Has been scanned. */
117 #define UNPGC_IGNORE_RIGHTS 0x8 /* Attached rights are freed */
119 #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb))
121 #endif /* _KERNEL || _WANT_UNPCB */
124 * UNPCB structure exported to user-land via sysctl(3).
126 * Fields prefixed with "xu_" are unique to the export structure, and fields
127 * with "unp_" or other prefixes match corresponding fields of 'struct unpcb'.
130 * (s) - used by userland utilities in src
131 * (p) - used by utilities in ports
132 * (3) - is known to be used by third party software not in ports
133 * (n) - no known usage
135 * Evil hack: declare only if sys/socketvar.h have been included.
137 #ifdef _SYS_SOCKETVAR_H_
139 size_t xu_len; /* length of this structure */
140 void *xu_unpp; /* to help netstat, fstat */
141 void *unp_vnode; /* (s) */
142 void *unp_conn; /* (s) */
143 void *xu_firstref; /* (s) */
144 void *xu_nextref; /* (s) */
145 unp_gen_t unp_gencnt; /* (s) */
146 int64_t xu_spare64[8];
147 int32_t xu_spare32[8];
149 struct sockaddr_un xu_addr; /* our bound address */
153 struct sockaddr_un xu_caddr; /* their bound address */
156 struct xsocket xu_socket;
165 #endif /* _SYS_SOCKETVAR_H_ */
167 #endif /* _SYS_UNPCB_H_ */