2 * Copyright (c) 1990, 1993
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29 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93
33 #ifndef _SYS_FILEDESC_H_
34 #define _SYS_FILEDESC_H_
36 #include <sys/caprights.h>
37 #include <sys/queue.h>
38 #include <sys/event.h>
40 #include <sys/priority.h>
43 #include <machine/_limits.h>
46 cap_rights_t fc_rights; /* per-descriptor capability rights */
47 u_long *fc_ioctls; /* per-descriptor allowed ioctls */
48 int16_t fc_nioctls; /* fc_ioctls array size */
49 uint32_t fc_fcntls; /* per-descriptor allowed fcntls */
53 struct file *fde_file; /* file structure for open file */
54 struct filecaps fde_caps; /* per-descriptor rights */
55 uint8_t fde_flags; /* per-process open file flags */
57 #define fde_rights fde_caps.fc_rights
58 #define fde_fcntls fde_caps.fc_fcntls
59 #define fde_ioctls fde_caps.fc_ioctls
60 #define fde_nioctls fde_caps.fc_nioctls
63 * This structure is used for the management of descriptors. It may be
64 * shared by multiple processes.
66 #define NDSLOTTYPE u_long
69 struct filedescent *fd_ofiles; /* open files */
70 struct vnode *fd_cdir; /* current directory */
71 struct vnode *fd_rdir; /* root directory */
72 struct vnode *fd_jdir; /* jail root directory */
73 int fd_nfiles; /* number of open files allocated */
74 NDSLOTTYPE *fd_map; /* bitmap of free fds */
75 int fd_lastfile; /* high-water mark of fd_ofiles */
76 int fd_freefile; /* approx. next free file */
77 u_short fd_cmask; /* mask for file creation */
78 u_short fd_refcnt; /* thread reference count */
79 u_short fd_holdcnt; /* hold count on structure + mutex */
80 struct sx fd_sx; /* protects members of this struct */
81 struct kqlist fd_kqlist; /* list of kqueues on this filedesc */
82 int fd_holdleaderscount; /* block fdfree() for shared close() */
83 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
87 * Structure to keep track of (process leader, struct fildedesc) tuples.
88 * Each process has a pointer to such a structure when detailed tracking
89 * is needed, e.g., when rfork(RFPROC | RFMEM) causes a file descriptor
90 * table to be shared by processes having different "p_leader" pointers
91 * and thus distinct POSIX style locks.
93 * fdl_refcount and fdl_holdcount are protected by struct filedesc mtx.
95 struct filedesc_to_leader {
96 int fdl_refcount; /* references from struct proc */
97 int fdl_holdcount; /* temporary hold during closef */
98 int fdl_wakeup; /* fdfree() waits on closef() */
99 struct proc *fdl_leader; /* owner of POSIX locks */
101 struct filedesc_to_leader *fdl_prev;
102 struct filedesc_to_leader *fdl_next;
106 * Per-process open flags.
108 #define UF_EXCLOSE 0x01 /* auto-close on exec */
112 /* Flags for do_dup() */
113 #define DUP_FIXED 0x1 /* Force fixed allocation. */
114 #define DUP_FCNTL 0x2 /* fcntl()-style errors. */
115 #define DUP_CLOEXEC 0x4 /* Atomically set FD_CLOEXEC. */
117 /* Lock a file descriptor table. */
118 #define FILEDESC_LOCK_INIT(fdp) sx_init(&(fdp)->fd_sx, "filedesc structure")
119 #define FILEDESC_LOCK_DESTROY(fdp) sx_destroy(&(fdp)->fd_sx)
120 #define FILEDESC_LOCK(fdp) (&(fdp)->fd_sx)
121 #define FILEDESC_XLOCK(fdp) sx_xlock(&(fdp)->fd_sx)
122 #define FILEDESC_XUNLOCK(fdp) sx_xunlock(&(fdp)->fd_sx)
123 #define FILEDESC_SLOCK(fdp) sx_slock(&(fdp)->fd_sx)
124 #define FILEDESC_SUNLOCK(fdp) sx_sunlock(&(fdp)->fd_sx)
126 #define FILEDESC_LOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_LOCKED | \
128 #define FILEDESC_XLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_XLOCKED | \
130 #define FILEDESC_UNLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_UNLOCKED)
134 void filecaps_init(struct filecaps *fcaps);
135 void filecaps_copy(const struct filecaps *src, struct filecaps *dst);
136 void filecaps_move(struct filecaps *src, struct filecaps *dst);
137 void filecaps_free(struct filecaps *fcaps);
139 int closef(struct file *fp, struct thread *td);
140 int do_dup(struct thread *td, int flags, int old, int new,
142 int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
143 int openerror, int *indxp);
144 int falloc(struct thread *td, struct file **resultfp, int *resultfd,
146 int falloc_noinstall(struct thread *td, struct file **resultfp);
147 int finstall(struct thread *td, struct file *fp, int *resultfp, int flags,
148 struct filecaps *fcaps);
149 int fdalloc(struct thread *td, int minfd, int *result);
150 int fdallocn(struct thread *td, int minfd, int *fds, int n);
151 int fdcheckstd(struct thread *td);
152 void fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td);
153 void fdcloseexec(struct thread *td);
154 struct filedesc *fdcopy(struct filedesc *fdp);
155 void fdunshare(struct thread *td);
156 void fdescfree(struct thread *td);
157 struct filedesc *fdinit(struct filedesc *fdp);
158 struct filedesc *fdshare(struct filedesc *fdp);
159 struct filedesc_to_leader *
160 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
161 struct filedesc *fdp, struct proc *leader);
162 int getvnode(struct filedesc *fdp, int fd, cap_rights_t *rightsp,
164 void mountcheckdirs(struct vnode *olddp, struct vnode *newdp);
165 void setugidsafety(struct thread *td);
167 /* Return a referenced file from an unlocked descriptor. */
168 int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
169 int needfcntl, struct file **fpp, cap_rights_t *haverightsp);
171 /* Requires a FILEDESC_{S,X}LOCK held and returns without a ref. */
172 static __inline struct file *
173 fget_locked(struct filedesc *fdp, int fd)
176 FILEDESC_LOCK_ASSERT(fdp);
178 if (fd < 0 || fd > fdp->fd_lastfile)
181 return (fdp->fd_ofiles[fd].fde_file);
186 #endif /* !_SYS_FILEDESC_H_ */