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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/queue.h>
37 #include <sys/event.h>
39 #include <sys/priority.h>
42 #include <machine/_limits.h>
45 cap_rights_t fc_rights; /* per-descriptor capability rights */
46 uint32_t fc_fcntls; /* per-descriptor allowed fcntls */
47 u_long *fc_ioctls; /* per-descriptor allowed ioctls */
48 int16_t fc_nioctls; /* fc_ioctls array size */
52 struct file *fde_file; /* file structure for open file */
53 struct filecaps fde_caps; /* per-descriptor rights */
54 uint8_t fde_flags; /* per-process open file flags */
56 #define fde_rights fde_caps.fc_rights
57 #define fde_fcntls fde_caps.fc_fcntls
58 #define fde_ioctls fde_caps.fc_ioctls
59 #define fde_nioctls fde_caps.fc_nioctls
62 * This structure is used for the management of descriptors. It may be
63 * shared by multiple processes.
65 #define NDSLOTTYPE u_long
68 struct filedescent *fd_ofiles; /* open files */
69 struct vnode *fd_cdir; /* current directory */
70 struct vnode *fd_rdir; /* root directory */
71 struct vnode *fd_jdir; /* jail root directory */
72 int fd_nfiles; /* number of open files allocated */
73 NDSLOTTYPE *fd_map; /* bitmap of free fds */
74 int fd_lastfile; /* high-water mark of fd_ofiles */
75 int fd_freefile; /* approx. next free file */
76 u_short fd_cmask; /* mask for file creation */
77 u_short fd_refcnt; /* thread reference count */
78 u_short fd_holdcnt; /* hold count on structure + mutex */
79 struct sx fd_sx; /* protects members of this struct */
80 struct kqlist fd_kqlist; /* list of kqueues on this filedesc */
81 int fd_holdleaderscount; /* block fdfree() for shared close() */
82 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
86 * Structure to keep track of (process leader, struct fildedesc) tuples.
87 * Each process has a pointer to such a structure when detailed tracking
88 * is needed, e.g., when rfork(RFPROC | RFMEM) causes a file descriptor
89 * table to be shared by processes having different "p_leader" pointers
90 * and thus distinct POSIX style locks.
92 * fdl_refcount and fdl_holdcount are protected by struct filedesc mtx.
94 struct filedesc_to_leader {
95 int fdl_refcount; /* references from struct proc */
96 int fdl_holdcount; /* temporary hold during closef */
97 int fdl_wakeup; /* fdfree() waits on closef() */
98 struct proc *fdl_leader; /* owner of POSIX locks */
100 struct filedesc_to_leader *fdl_prev;
101 struct filedesc_to_leader *fdl_next;
105 * Per-process open flags.
107 #define UF_EXCLOSE 0x01 /* auto-close on exec */
111 #include <sys/systm.h> /* CTASSERT() */
113 CTASSERT(sizeof(cap_rights_t) == sizeof(uint64_t));
115 /* Flags for do_dup() */
116 #define DUP_FIXED 0x1 /* Force fixed allocation. */
117 #define DUP_FCNTL 0x2 /* fcntl()-style errors. */
118 #define DUP_CLOEXEC 0x4 /* Atomically set FD_CLOEXEC. */
120 /* Lock a file descriptor table. */
121 #define FILEDESC_LOCK_INIT(fdp) sx_init(&(fdp)->fd_sx, "filedesc structure")
122 #define FILEDESC_LOCK_DESTROY(fdp) sx_destroy(&(fdp)->fd_sx)
123 #define FILEDESC_LOCK(fdp) (&(fdp)->fd_sx)
124 #define FILEDESC_XLOCK(fdp) sx_xlock(&(fdp)->fd_sx)
125 #define FILEDESC_XUNLOCK(fdp) sx_xunlock(&(fdp)->fd_sx)
126 #define FILEDESC_SLOCK(fdp) sx_slock(&(fdp)->fd_sx)
127 #define FILEDESC_SUNLOCK(fdp) sx_sunlock(&(fdp)->fd_sx)
129 #define FILEDESC_LOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_LOCKED | \
131 #define FILEDESC_XLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_XLOCKED | \
133 #define FILEDESC_UNLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_UNLOCKED)
137 void filecaps_init(struct filecaps *fcaps);
138 void filecaps_copy(const struct filecaps *src, struct filecaps *dst);
139 void filecaps_move(struct filecaps *src, struct filecaps *dst);
140 void filecaps_free(struct filecaps *fcaps);
142 int closef(struct file *fp, struct thread *td);
143 int do_dup(struct thread *td, int flags, int old, int new,
145 int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
146 int openerror, int *indxp);
147 int falloc(struct thread *td, struct file **resultfp, int *resultfd,
149 int falloc_noinstall(struct thread *td, struct file **resultfp);
150 int finstall(struct thread *td, struct file *fp, int *resultfp, int flags,
151 struct filecaps *fcaps);
152 int fdalloc(struct thread *td, int minfd, int *result);
153 int fdavail(struct thread *td, int n);
154 int fdcheckstd(struct thread *td);
155 void fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td);
156 void fdcloseexec(struct thread *td);
157 struct filedesc *fdcopy(struct filedesc *fdp);
158 void fdunshare(struct proc *p, struct thread *td);
159 void fdescfree(struct thread *td);
160 struct filedesc *fdinit(struct filedesc *fdp);
161 struct filedesc *fdshare(struct filedesc *fdp);
162 struct filedesc_to_leader *
163 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
164 struct filedesc *fdp, struct proc *leader);
165 int getvnode(struct filedesc *fdp, int fd, cap_rights_t rights,
167 void mountcheckdirs(struct vnode *olddp, struct vnode *newdp);
168 void setugidsafety(struct thread *td);
170 /* Return a referenced file from an unlocked descriptor. */
171 int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t needrights,
172 int needfcntl, struct file **fpp, cap_rights_t *haverightsp);
174 /* Requires a FILEDESC_{S,X}LOCK held and returns without a ref. */
175 static __inline struct file *
176 fget_locked(struct filedesc *fdp, int fd)
179 FILEDESC_LOCK_ASSERT(fdp);
181 if (fd < 0 || fd >= fdp->fd_nfiles)
184 return (fdp->fd_ofiles[fd].fde_file);
189 #endif /* !_SYS_FILEDESC_H_ */