summaryrefslogtreecommitdiff
path: root/isofs/lookup.c
diff options
context:
space:
mode:
Diffstat (limited to 'isofs/lookup.c')
-rw-r--r--isofs/lookup.c448
1 files changed, 448 insertions, 0 deletions
diff --git a/isofs/lookup.c b/isofs/lookup.c
new file mode 100644
index 00000000..faed5d28
--- /dev/null
+++ b/isofs/lookup.c
@@ -0,0 +1,448 @@
+/*
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ Written by Thomas Bushnell, n/BSG.
+
+ This file is part of the GNU Hurd.
+
+ The GNU Hurd is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2, or (at
+ your option) any later version.
+
+ The GNU Hurd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
+
+#include <string.h>
+#include <dirent.h>
+#include "isofs.h"
+
+/* Forward */
+static error_t
+dirscanblock (void *, char *, size_t, struct dirrect **, struct rrip_lookup *);
+
+static int
+isonamematch (char *dirname, size_t dnamelen, char *username, size_t unamelen)
+{
+ /* Special representations for `.' and `..' */
+ if (dnamelen == 1 && dirname[0] == '\0')
+ return unamelen == 1 && username[0] == '.';
+
+ if (dnamelen == 1 && dirname[0] == '\1')
+ return unamelen == 2 && username[0] == '.' && username[1] == '.';
+
+ if (unamelen > dnamelen)
+ return 0;
+
+ if (!strncasecmp (dirname, username, unamelen))
+ {
+ /* A prefix has matched. Check if it's acceptable. */
+ if (dnamelen == unamelen)
+ return 1;
+
+ /* User has ommitted the version number */
+ if (dirname[unamelen] == ';')
+ return 1;
+
+ /* User has ommitted an empty extension */
+ if (dirname[unamelen] == '.'
+ && (dirname[unamelen+1] == '\0' || dirname[unamelen+1] == ';'))
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Implement the diskfs_lookup callback from the diskfs library. See
+ <hurd/diskfs.h> for the interface specification. */
+error_t
+diskfs_lookup_hard (struct node *dp, char *name, enum lookup_type type,
+ struct node **npp, struct dirstat *ds, struct protid *cred)
+{
+ error_t err = 0;
+ struct dirrect *record;
+ int namelen;
+ int spec_dotdot;
+ void *buf;
+ void *blockaddr;
+ struct rrip_lookup rr;
+
+ if ((type == REMOVE) || (type == RENAME))
+ assert (npp);
+
+ if (npp)
+ *npp = 0;
+
+ spec_dotdot = type & SPEC_DOTDOT;
+ type &= ~SPEC_DOTDOT;
+
+ namelen = strlen (name);
+
+ /* This error is constant, but the errors for CREATE and REMOVE depend
+ on whether NAME exists. */
+ if (type == RENAME)
+ return EROFS;
+
+ buf = disk_image + (dp->dn->file_start << store->log2_block_size);
+
+ for (blockaddr = buf;
+ blockaddr < buf + dp->dn_stat.st_size;
+ blockaddr += logical_sector_size)
+ {
+ err = dirscanblock (blockaddr, name, namelen, &record, &rr);
+
+ if (!err)
+ break;
+
+ if (err != ENOENT)
+ return err;
+ }
+
+ if ((!err && type == REMOVE)
+ || (err == ENOENT && type == CREATE))
+ err = EROFS;
+
+ if (err)
+ return err;
+
+ /* Load the inode */
+ if (namelen == 2 && name[0] == '.' && name[1] == '.')
+ {
+ if (dp == diskfs_root_node)
+ err = EAGAIN;
+ else if (spec_dotdot)
+ {
+ /* renames and removes can't get this far. */
+ assert (type == LOOKUP);
+ diskfs_nput (dp);
+ err = load_inode (npp, record, &rr);
+ }
+ else
+ {
+ /* We don't have to do the normal rigamarole, because
+ we are permanently read-only, so things are necessarily
+ quiescent. Just be careful to honor the locking order. */
+ mutex_unlock (&dp->lock);
+ err = load_inode (npp, record, &rr);
+ mutex_lock (&dp->lock);
+ }
+ }
+ else if (namelen == 1 && name[0] == '.')
+ {
+ *npp = dp;
+ diskfs_nref (dp);
+ }
+ else
+ err = load_inode (npp, record, &rr);
+
+ release_rrip (&rr);
+ return err;
+}
+
+
+/* Scan one logical sector of directory contents (at address BLKADDR)
+ for NAME of length NAMELEN. Return its address in *RECORD. */
+static error_t
+dirscanblock (void *blkaddr, char *name, size_t namelen,
+ struct dirrect **record, struct rrip_lookup *rr)
+{
+ struct dirrect *entry;
+ void *currentoff;
+ size_t reclen;
+ size_t entry_namelen;
+ int matchrr;
+ int matchnormal;
+
+ for (currentoff = blkaddr;
+ currentoff < blkaddr + logical_sector_size;
+ currentoff += reclen)
+ {
+ entry = (struct dirrect *) currentoff;
+
+ reclen = entry->len;
+
+ /* Validate reclen */
+ if (reclen == 0
+ || reclen < sizeof (struct dirrect)
+ || currentoff + reclen > blkaddr + logical_sector_size)
+ break;
+
+ entry_namelen = entry->namelen;
+
+ /* More validation */
+ if (reclen < sizeof (struct dirrect) + entry_namelen)
+ break;
+
+ /* Check to see if the name maches the directory entry. */
+ if (isonamematch (entry->name, entry_namelen, name, namelen))
+ matchnormal = 1;
+ else
+ matchnormal = 0;
+
+ /* Now scan for RRIP fields */
+ matchrr = rrip_match_lookup (entry, name, namelen, rr);
+
+ /* Ignore RE entries */
+ if (rr->valid & VALID_RE)
+ {
+ release_rrip (rr);
+ continue;
+ }
+
+ /* See if the name matches */
+ if (((rr->valid & VALID_NM) && matchrr)
+ || (!(rr->valid & VALID_NM) && matchnormal))
+ {
+ /* We've got it. Return success */
+ *record = entry;
+ return 0;
+ }
+
+ release_rrip (rr);
+ }
+
+ /* Wasn't there. */
+ *record = 0;
+ return ENOENT;
+}
+
+error_t
+diskfs_get_directs (struct node *dp,
+ int entry,
+ int nentries,
+ char **data,
+ u_int *datacnt,
+ vm_size_t bufsiz,
+ int *amt)
+{
+ volatile vm_size_t allocsize;
+ struct dirrect *ep;
+ struct dirent *userp;
+ int i;
+ void *dirbuf, *bufp;
+ char *datap;
+ volatile int ouralloc = 0;
+ error_t err;
+
+ /* Allocate some space to hold the returned data. */
+ allocsize = bufsiz ? round_page (bufsiz) : vm_page_size * 4;
+ if (allocsize > *datacnt)
+ {
+ vm_allocate (mach_task_self (), (vm_address_t *) data, allocsize, 1);
+ ouralloc = 1;
+ }
+
+ err = diskfs_catch_exception ();
+ if (err)
+ {
+ if (ouralloc)
+ vm_deallocate (mach_task_self (), (vm_address_t)*data, allocsize);
+ return err;
+ }
+
+ /* Skip to ENTRY */
+ dirbuf = disk_image + (dp->dn->file_start << store->log2_block_size);
+ bufp = dirbuf;
+ for (i = 0; i < entry; i ++)
+ {
+ struct rrip_lookup rr;
+
+ ep = (struct dirrect *) bufp;
+ rrip_lookup (ep, &rr, 0);
+
+ /* Ignore and skip RE entries */
+ if (rr.valid & VALID_RE)
+ {
+ bufp = bufp + ep->len;
+ release_rrip (&rr);
+ continue;
+ }
+
+ if (bufp - dirbuf >= dp->dn_stat.st_size)
+ {
+ /* Not that many entries in the directory; return nothing. */
+ if (allocsize > *datacnt)
+ vm_deallocate (mach_task_self (), (vm_address_t) data, allocsize);
+ *datacnt = 0;
+ *amt = 0;
+ return 0;
+ }
+ bufp = bufp + ep->len;
+
+ /* If BUFP points at a null, then we have hit the last
+ record in this logical sector. In that case, skip up to
+ the next logical sector. */
+ if (*(char *)bufp == '\0')
+ bufp = (void *) (((long) bufp & ~(logical_sector_size - 1))
+ + logical_sector_size);
+ }
+
+ /* Now copy entries one at a time */
+ i = 0;
+ datap = *data;
+ while (((nentries == -1) || (i < nentries))
+ && (!bufsiz || datap - *data < bufsiz)
+ && ((void *) bufp - dirbuf < dp->dn_stat.st_size))
+ {
+ struct rrip_lookup rr;
+ char *name;
+ size_t namlen, reclen;
+ off_t file_start;
+
+ ep = (struct dirrect *) bufp;
+
+ /* Fetch Rock-Ridge information for this file */
+ rrip_lookup (ep, &rr, 0);
+
+ /* Ignore and skip RE entries */
+ if (rr.valid & VALID_RE)
+ {
+ bufp = bufp + ep->len;
+ release_rrip (&rr);
+ continue;
+ }
+
+ /* See if there's room to hold this one */
+ name = rr.valid & VALID_NM ? rr.name : ep->name;
+ namlen = rr.valid & VALID_NM ? strlen (name) : ep->namelen;
+
+ /* Name frobnication */
+ if (!(rr.valid & VALID_NM))
+ {
+ if (namlen == 1 && name[0] == '\0')
+ {
+ name = ".";
+ namlen = 1;
+ }
+ else if (namlen == 1 && name[0] == '\1')
+ {
+ name = "..";
+ namlen = 2;
+ }
+ /* Perhaps downcase it too? */
+ }
+
+ reclen = sizeof (struct dirent) + namlen;
+ reclen = (reclen + 3) & ~3;
+
+ /* Expand buffer if necessary */
+ if (datap - *data + reclen > allocsize)
+ {
+ vm_address_t newdata;
+
+ vm_allocate (mach_task_self (), &newdata,
+ (ouralloc
+ ? (allocsize *= 2)
+ : (allocsize = vm_page_size * 2)), 1);
+ bcopy ((void *) *data, (void *)newdata, datap - *data);
+
+ if (ouralloc)
+ vm_deallocate (mach_task_self (), (vm_address_t) *data,
+ allocsize / 2);
+
+ datap = (char *) newdata + (datap - *data);
+ *data = (char *) newdata;
+ ouralloc = 1;
+ }
+
+ userp = (struct dirent *) datap;
+
+ /* Fill in entry */
+
+ err = calculate_file_start (ep, &file_start, &rr);
+ if (err)
+ {
+ diskfs_end_catch_exception ();
+ if (ouralloc)
+ vm_deallocate (mach_task_self (), (vm_address_t) *data, allocsize);
+ return err;
+ }
+
+ userp->d_fileno = file_start;
+ userp->d_type = DT_UNKNOWN;
+ userp->d_reclen = reclen;
+ userp->d_namlen = namlen;
+ bcopy (name, userp->d_name, namlen);
+ userp->d_name[namlen] = '\0';
+
+ /* And move along */
+ release_rrip (&rr);
+ datap = datap + reclen;
+ bufp = bufp + ep->len;
+ i++;
+
+ /* If BUFP points at a null, then we have hit the last
+ record in this logical sector. In that case, skip up to
+ the next logical sector. */
+ if (*(char *)bufp == '\0')
+ bufp = (void *) (((long) bufp & ~(logical_sector_size - 1))
+ + logical_sector_size);
+ }
+
+ diskfs_end_catch_exception ();
+
+ /* If we didn't use all the pages of a buffer we allocated, free
+ the excess. */
+ if (ouralloc
+ && round_page (datap - *data) < round_page (allocsize))
+ vm_deallocate (mach_task_self (), round_page (datap),
+ round_page (allocsize) - round_page (datap - *data));
+
+ /* Return */
+ *amt = i;
+ *datacnt = datap - *data;
+ return 0;
+}
+
+/* We have no dirstats at all. */
+size_t diskfs_dirstat_size = 0;
+
+void
+diskfs_null_dirstat (struct dirstat *ds)
+{
+}
+
+error_t
+diskfs_drop_dirstat (struct node *dp, struct dirstat *ds)
+{
+ return 0;
+}
+
+/* These should never be called. */
+
+error_t
+diskfs_direnter_hard(struct node *dp,
+ char *name,
+ struct node *np,
+ struct dirstat *ds,
+ struct protid *cred)
+{
+ abort ();
+}
+
+error_t
+diskfs_dirremove_hard(struct node *dp,
+ struct dirstat *ds)
+{
+ abort ();
+}
+
+error_t
+diskfs_dirrewrite_hard(struct node *dp,
+ struct node *np,
+ struct dirstat *ds)
+{
+ abort ();
+}
+
+int
+diskfs_dirempty(struct node *dp,
+ struct protid *cred)
+{
+ abort ();
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-28 21:16:13 +0000