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29 * @(#)unpcb.h 8.1 (Berkeley) 6/2/93
36 #include <sys/queue.h>
37 #include <sys/ucred.h>
40 * Protocol control block for an active
41 * instance of a UNIX internal protocol.
43 * A socket may be associated with a vnode in the
44 * filesystem. If so, the unp_vnode pointer holds
45 * a reference count to this vnode, which should be irele'd
46 * when the socket goes away.
48 * A socket may be connected to another socket, in which
49 * case the control block of the socket to which it is connected
50 * is given by unp_conn.
52 * A socket may be referenced by a number of sockets (e.g. several
53 * sockets may be connected to a datagram socket.) These sockets
54 * are in a linked list starting with unp_refs, linked through
55 * unp_nextref and null-terminated. Note that a socket may be referenced
56 * by a number of other sockets and may also reference a socket (not
57 * necessarily one which is referencing it). This generates
58 * the need for unp_refs and unp_nextref to be separate fields.
60 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt
61 * so that changes in the sockbuf may be computed to modify
62 * back pressure on the sender accordingly.
64 typedef u_quad_t unp_gen_t;
65 LIST_HEAD(unp_head, unpcb);
68 LIST_ENTRY(unpcb) unp_link; /* glue on list of all PCBs */
69 struct socket *unp_socket; /* pointer back to socket */
70 struct file *unp_file; /* back-pointer to file for gc. */
71 struct vnode *unp_vnode; /* if associated with file */
72 ino_t unp_ino; /* fake inode number */
73 struct unpcb *unp_conn; /* control block of connected socket */
74 struct unp_head unp_refs; /* referencing socket linked list */
75 LIST_ENTRY(unpcb) unp_reflink; /* link in unp_refs list */
76 struct sockaddr_un *unp_addr; /* bound address of socket */
79 unp_gen_t unp_gencnt; /* generation count of this instance */
80 short unp_flags; /* flags */
81 short unp_gcflag; /* Garbage collector flags. */
82 struct xucred unp_peercred; /* peer credentials, if applicable */
84 u_int unp_msgcount; /* references from message queue */
85 struct mtx unp_mtx; /* mutex */
91 * UNP_HAVEPC - indicates that the unp_peercred member is filled in
92 * and is really the credentials of the connected peer. This is used
93 * to determine whether the contents should be sent to the user or
96 * UNP_HAVEPCCACHED - indicates that the unp_peercred member is filled
97 * in, but does *not* contain the credentials of the connected peer
98 * (there may not even be a peer). This is set in unp_listen() when
99 * it fills in unp_peercred for later consumption by unp_connect().
101 #define UNP_HAVEPC 0x001
102 #define UNP_HAVEPCCACHED 0x002
103 #define UNP_WANTCRED 0x004 /* credentials wanted */
104 #define UNP_CONNWAIT 0x008 /* connect blocks until accepted */
107 * These flags are used to handle non-atomicity in connect() and bind()
108 * operations on a socket: in particular, to avoid races between multiple
109 * threads or processes operating simultaneously on the same socket.
111 #define UNP_CONNECTING 0x010 /* Currently connecting. */
112 #define UNP_BINDING 0x020 /* Currently binding. */
113 #define UNP_NASCENT 0x040 /* Newborn child socket. */
116 * Flags in unp_gcflag.
118 #define UNPGC_REF 0x1 /* unpcb has external ref. */
119 #define UNPGC_DEAD 0x2 /* unpcb might be dead. */
120 #define UNPGC_SCANNED 0x4 /* Has been scanned. */
121 #define UNPGC_IGNORE_RIGHTS 0x8 /* Attached rights are freed */
123 #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb))
125 /* Hack alert -- this structure depends on <sys/socketvar.h>. */
126 #ifdef _SYS_SOCKETVAR_H_
128 size_t xu_len; /* length of this structure */
129 struct unpcb *xu_unpp; /* to help netstat, fstat */
130 struct unpcb xu_unp; /* our information */
132 struct sockaddr_un xuu_addr; /* our bound address */
135 #define xu_addr xu_au.xuu_addr
137 struct sockaddr_un xuu_caddr; /* their bound address */
140 #define xu_caddr xu_cau.xuu_caddr
141 struct xsocket xu_socket;
142 u_quad_t xu_alignment_hack;
151 #endif /* _SYS_SOCKETVAR_H_ */
153 #endif /* _SYS_UNPCB_H_ */