Annotation of sys/compat/common/compat_dir.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: compat_dir.c,v 1.4 2003/08/14 16:55:24 fgsch Exp $ */
! 2:
! 3: /*
! 4: * Copyright (c) 2000 Constantine Sapuntzakis
! 5: * All rights reserved.
! 6: *
! 7: * Redistribution and use in source and binary forms, with or without
! 8: * modification, are permitted provided that the following conditions
! 9: * are met:
! 10: * 1. Redistributions of source code must retain the above copyright
! 11: * notice, this list of conditions and the following disclaimer.
! 12: * 2. The name of the author may not be used to endorse or promote products
! 13: * derived from this software without specific prior written permission
! 14: *
! 15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
! 16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
! 17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
! 18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
! 19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
! 20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
! 21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
! 22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
! 23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
! 24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
! 25: *
! 26: */
! 27:
! 28: #include <sys/param.h>
! 29: #include <sys/systm.h>
! 30: #include <sys/namei.h>
! 31: #include <sys/proc.h>
! 32: #include <sys/file.h>
! 33: #include <sys/stat.h>
! 34: #include <sys/filedesc.h>
! 35: #include <sys/ioctl.h>
! 36: #include <sys/kernel.h>
! 37: #include <sys/malloc.h>
! 38: #include <sys/vnode.h>
! 39: #include <sys/dirent.h>
! 40:
! 41: #include <compat/common/compat_dir.h>
! 42:
! 43: int
! 44: readdir_with_callback(fp, off, nbytes, appendfunc, arg)
! 45: struct file *fp;
! 46: off_t *off;
! 47: u_long nbytes;
! 48: int (*appendfunc)(void *, struct dirent *, off_t);
! 49: void *arg;
! 50: {
! 51: struct dirent *bdp;
! 52: caddr_t inp, buf;
! 53: int buflen;
! 54: struct uio auio;
! 55: struct iovec aiov;
! 56: int eofflag = 0;
! 57: u_long *cookies = NULL, *cookiep;
! 58: int ncookies = 0;
! 59: int error, len, reclen;
! 60: off_t newoff = *off;
! 61: struct vnode *vp;
! 62: struct vattr va;
! 63:
! 64: if ((fp->f_flag & FREAD) == 0)
! 65: return (EBADF);
! 66:
! 67: vp = (struct vnode *)fp->f_data;
! 68:
! 69: if (vp->v_type != VDIR)
! 70: return (EINVAL);
! 71:
! 72: if ((error = VOP_GETATTR(vp, &va, fp->f_cred, curproc)) != 0)
! 73: return (error);
! 74:
! 75: buflen = min(MAXBSIZE, nbytes);
! 76: buflen = max(buflen, va.va_blocksize);
! 77: buf = malloc(buflen, M_TEMP, M_WAITOK);
! 78: error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curproc);
! 79: if (error)
! 80: goto out;
! 81:
! 82: again:
! 83: aiov.iov_base = buf;
! 84: aiov.iov_len = buflen;
! 85: auio.uio_iov = &aiov;
! 86: auio.uio_iovcnt = 1;
! 87: auio.uio_rw = UIO_READ;
! 88: auio.uio_segflg = UIO_SYSSPACE;
! 89: auio.uio_procp = curproc;
! 90: auio.uio_resid = buflen;
! 91: auio.uio_offset = newoff;
! 92:
! 93: if (cookies) {
! 94: free(cookies, M_TEMP);
! 95: cookies = NULL;
! 96: }
! 97:
! 98: error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &ncookies,
! 99: &cookies);
! 100: if (error)
! 101: goto out;
! 102:
! 103: if ((len = buflen - auio.uio_resid) <= 0)
! 104: goto eof;
! 105:
! 106: cookiep = cookies;
! 107: inp = buf;
! 108:
! 109: if (cookies) {
! 110: /*
! 111: * When using cookies, the vfs has the option of reading from
! 112: * a different offset than that supplied (UFS truncates the
! 113: * offset to a block boundary to make sure that it never reads
! 114: * partway through a directory entry, even if the directory
! 115: * has been compacted).
! 116: */
! 117: while (len > 0 && ncookies > 0 && *cookiep <= newoff) {
! 118: bdp = (struct dirent *)inp;
! 119: len -= bdp->d_reclen;
! 120: inp += bdp->d_reclen;
! 121: cookiep++;
! 122: ncookies--;
! 123: }
! 124: }
! 125:
! 126: for (; len > 0; len -= reclen, inp += reclen) {
! 127: if (cookiep && ncookies == 0)
! 128: break;
! 129:
! 130: bdp = (struct dirent *)inp;
! 131: reclen = bdp->d_reclen;
! 132:
! 133: if (len < reclen)
! 134: break;
! 135:
! 136: if (reclen & 3) {
! 137: error = EFAULT;
! 138: goto out;
! 139: }
! 140:
! 141: /* Skip holes */
! 142: if (bdp->d_fileno != 0) {
! 143: if ((error = (*appendfunc) (arg, bdp,
! 144: (cookiep) ? *cookiep : (newoff + reclen))) != 0) {
! 145: if (error == ENOMEM)
! 146: error = 0;
! 147: break;
! 148: }
! 149: }
! 150:
! 151: if (cookiep) {
! 152: newoff = *cookiep++;
! 153: ncookies--;
! 154: } else
! 155: newoff += reclen;
! 156: }
! 157:
! 158: if (len <= 0 && !eofflag)
! 159: goto again;
! 160:
! 161: eof:
! 162: out:
! 163: if (error == 0)
! 164: *off = newoff;
! 165:
! 166: if (cookies)
! 167: free(cookies, M_TEMP);
! 168:
! 169: VOP_UNLOCK(vp, 0, curproc);
! 170: free(buf, M_TEMP);
! 171: return (error);
! 172: }
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