BSD的TCP/IP协议栈

/* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)vnode.h 8.17 (Berkeley) 5/20/95 */ #include <sys/lock.h> #include <sys/queue.h> /* * The vnode is the focus of all file activity in UNIX. There is a * unique vnode allocated for each active file, each current directory, * each mounted-on file, text file, and the root. */ /* * Vnode types. VNON means no type. */ enum vtype { VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO, VBAD }; /* * Vnode tag types. * These are for the benefit of external programs only (e.g., pstat) * and should NEVER be inspected by the kernel. */ enum vtagtype { VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_PC, VT_LFS, VT_LOFS, VT_FDESC, VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS, VT_UNION }; /* * Each underlying filesystem allocates its own private area and hangs * it from v_data. If non-null, this area is freed in getnewvnode(). */ LIST_HEAD(buflists, buf); /* * Reading or writing any of these items requires holding the appropriate lock. * v_freelist is locked by the global vnode_free_list simple lock. * v_mntvnodes is locked by the global mntvnodes simple lock. * v_flag, v_usecount, v_holdcount and v_writecount are * locked by the v_interlock simple lock. */ struct vnode { u_long v_flag; /* vnode flags (see below) */ short v_usecount; /* reference count of users */ short v_writecount; /* reference count of writers */ long v_holdcnt; /* page & buffer references */ daddr_t v_lastr; /* last read (read-ahead) */ u_long v_id; /* capability identifier */ struct mount *v_mount; /* ptr to vfs we are in */ int (**v_op)(); /* vnode operations vector */ TAILQ_ENTRY(vnode) v_freelist; /* vnode freelist */ LIST_ENTRY(vnode) v_mntvnodes; /* vnodes for mount point */ struct buflists v_cleanblkhd; /* clean blocklist head */ struct buflists v_dirtyblkhd; /* dirty blocklist head */ long v_numoutput; /* num of writes in progress */ enum vtype v_type; /* vnode type */ union { struct mount *vu_mountedhere;/* ptr to mounted vfs (VDIR) */ struct socket *vu_socket; /* unix ipc (VSOCK) */ caddr_t vu_vmdata; /* private data for vm (VREG) */ struct specinfo *vu_specinfo; /* device (VCHR, VBLK) */ struct fifoinfo *vu_fifoinfo; /* fifo (VFIFO) */ } v_un; struct nqlease *v_lease; /* Soft reference to lease */ daddr_t v_lastw; /* last write (write cluster) */ daddr_t v_cstart; /* start block of cluster */ daddr_t v_lasta; /* last allocation */ int v_clen; /* length of current cluster */ int v_ralen; /* Read-ahead length */ daddr_t v_maxra; /* last readahead block */ struct simplelock v_interlock; /* lock on usecount and flag */ struct lock *v_vnlock; /* used for non-locking fs's */ long v_spare[5]; /* round to 128 bytes */ enum vtagtype v_tag; /* type of underlying data */ void *v_data; /* private data for fs */ }; #define v_mountedhere v_un.vu_mountedhere #define v_socket v_un.vu_socket #define v_vmdata v_un.vu_vmdata #define v_specinfo v_un.vu_specinfo #define v_fifoinfo v_un.vu_fifoinfo /* * Vnode flags. */ #define VROOT 0x0001 /* root of its file system */ #define VTEXT 0x0002 /* vnode is a pure text prototype */ #define VSYSTEM 0x0004 /* vnode being used by kernel */ #define VISTTY 0x0008 /* vnode represents a tty */ #define VXLOCK 0x0100 /* vnode is locked to change underlying type */ #define VXWANT 0x0200 /* process is waiting for vnode */ #define VBWAIT 0x0400 /* waiting for output to complete */ #define VALIASED 0x0800 /* vnode has an alias */ #define VDIROP 0x1000 /* LFS: vnode is involved in a directory op */ /* * Vnode attributes. A field value of VNOVAL represents a field whose value * is unavailable (getattr) or which is not to be changed (setattr). */ struct vattr { enum vtype va_type; /* vnode type (for create) */ u_short va_mode; /* files access mode and type */ short va_nlink; /* number of references to file */ uid_t va_uid; /* owner user id */ gid_t va_gid; /* owner group id */ long va_fsid; /* file system id (dev for now) */ long va_fileid; /* file id */ u_quad_t va_size; /* file size in bytes */ long va_blocksize; /* blocksize preferred for i/o */ struct timespec va_atime; /* time of last access */ struct timespec va_mtime; /* time of last modification */ struct timespec va_ctime; /* time file changed */ u_long va_gen; /* generation number of file */ u_long va_flags; /* flags defined for file */ dev_t va_rdev; /* device the special file represents */ u_quad_t va_bytes; /* bytes of disk space held by file */ u_quad_t va_filerev; /* file modification number */ u_int va_vaflags; /* operations flags, see below */ long va_spare; /* remain quad aligned */ }; /* * Flags for va_vaflags. */ #define VA_UTIMES_NULL 0x01 /* utimes argument was NULL */ #define VA_EXCLUSIVE 0x02 /* exclusive create request */ /* * Flags for ioflag. */ #define IO_UNIT 0x01 /* do I/O as atomic unit */ #define IO_APPEND 0x02 /* append write to end */ #define IO_SYNC 0x04 /* do I/O synchronously */ #define IO_NODELOCKED 0x08 /* underlying node already locked */ #define IO_NDELAY 0x10 /* FNDELAY flag set in file table */ /* * Modes. Some values same as Ixxx entries from inode.h for now. */ #define VSUID 04000 /* set user id on execution */ #define VSGID 02000 /* set group id on execution */ #define VSVTX 01000 /* save swapped text even after use */ #define VREAD 00400 /* read, write, execute permissions */ #define VWRITE 00200 #define VEXEC 00100 /* * Token indicating no attribute value yet assigned. */ #define VNOVAL (-1) #ifdef KERNEL /* * Convert between vnode types and inode formats (since POSIX.1 * defines mode word of stat structure in terms of inode formats). */ extern enum vtype iftovt_tab[]; extern int vttoif_tab[]; #define IFTOVT(mode) (iftovt_tab[((mode) & S_IFMT) >> 12]) #define VTTOIF(indx) (vttoif_tab[(int)(indx)]) #define MAKEIMODE(indx, mode) (int)(VTTOIF(indx) | (mode)) /* * Flags to various vnode functions. */ #define SKIPSYSTEM 0x0001 /* vflush: skip vnodes marked VSYSTEM */ #define FORCECLOSE 0x0002 /* vflush: force file closeure */ #define WRITECLOSE 0x0004 /* vflush: only cl