- introduce new call numbers, names, and field aliases; - initialize request messages to zero for all ABI calls; - format callnr.h in the same way as com.h; - redo call tables in both servers; - remove param.h namespace pollution in the servers; - make brk(2) go to VM directly, rather than through PM; - remove obsolete BRK, UTIME, and WAIT calls; - clean up path copying routine in VFS; - move remaining system calls from libminlib to libc; - correct some errno-related mistakes in libc routines. Change-Id: I2d8ec5d061cd7e0b30c51ffd77aa72ebf84e2565
876 lines
25 KiB
C
876 lines
25 KiB
C
/* lookup() is the main routine that controls the path name lookup. It
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* handles mountpoints and symbolic links. The actual lookup requests
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* are sent through the req_lookup wrapper function.
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*/
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#include "fs.h"
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#include <string.h>
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/const.h>
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#include <minix/endpoint.h>
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#include <stddef.h>
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#include <unistd.h>
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#include <assert.h>
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#include <minix/vfsif.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <sys/un.h>
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#include <sys/dirent.h>
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#include "vmnt.h"
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#include "vnode.h"
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#include "path.h"
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/* Set to following define to 1 if you really want to use the POSIX definition
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* (IEEE Std 1003.1, 2004) of pathname resolution. POSIX requires pathnames
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* with a traling slash (and that do not entirely consist of slash characters)
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* to be treated as if a single dot is appended. This means that for example
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* mkdir("dir/", ...) and rmdir("dir/") will fail because the call tries to
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* create or remove the directory '.'. Historically, Unix systems just ignore
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* trailing slashes.
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*/
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#define DO_POSIX_PATHNAME_RES 0
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static int lookup(struct vnode *dirp, struct lookup *resolve,
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node_details_t *node, struct fproc *rfp);
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static int check_perms(endpoint_t ep, cp_grant_id_t io_gr, size_t
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pathlen);
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/*===========================================================================*
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* advance *
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*===========================================================================*/
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struct vnode *advance(dirp, resolve, rfp)
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struct vnode *dirp;
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struct lookup *resolve;
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struct fproc *rfp;
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{
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/* Resolve a path name starting at dirp to a vnode. */
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int r;
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int do_downgrade = 1;
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struct vnode *new_vp, *vp;
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struct vmnt *vmp;
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struct node_details res = {0,0,0,0,0,0,0};
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tll_access_t initial_locktype;
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assert(dirp);
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assert(resolve->l_vnode_lock != TLL_NONE);
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assert(resolve->l_vmnt_lock != TLL_NONE);
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if (resolve->l_vnode_lock == VNODE_READ)
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initial_locktype = VNODE_OPCL;
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else
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initial_locktype = resolve->l_vnode_lock;
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/* Get a free vnode and lock it */
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if ((new_vp = get_free_vnode()) == NULL) return(NULL);
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lock_vnode(new_vp, initial_locktype);
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/* Lookup vnode belonging to the file. */
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if ((r = lookup(dirp, resolve, &res, rfp)) != OK) {
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err_code = r;
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unlock_vnode(new_vp);
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return(NULL);
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}
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/* Check whether we already have a vnode for that file */
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if ((vp = find_vnode(res.fs_e, res.inode_nr)) != NULL) {
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unlock_vnode(new_vp); /* Don't need this anymore */
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do_downgrade = (lock_vnode(vp, initial_locktype) != EBUSY);
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/* Unfortunately, by the time we get the lock, another thread might've
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* rid of the vnode (e.g., find_vnode found the vnode while a
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* req_putnode was being processed). */
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if (vp->v_ref_count == 0) { /* vnode vanished! */
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/* As the lookup before increased the usage counters in the FS,
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* we can simply set the usage counters to 1 and proceed as
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* normal, because the putnode resulted in a use count of 1 in
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* the FS. Other data is still valid, because the vnode was
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* marked as pending lock, so get_free_vnode hasn't
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* reinitialized the vnode yet. */
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vp->v_fs_count = 1;
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if (vp->v_mapfs_e != NONE) vp->v_mapfs_count = 1;
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} else {
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vp->v_fs_count++; /* We got a reference from the FS */
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}
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} else {
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/* Vnode not found, fill in the free vnode's fields */
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new_vp->v_fs_e = res.fs_e;
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new_vp->v_inode_nr = res.inode_nr;
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new_vp->v_mode = res.fmode;
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new_vp->v_size = res.fsize;
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new_vp->v_uid = res.uid;
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new_vp->v_gid = res.gid;
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new_vp->v_sdev = res.dev;
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if( (vmp = find_vmnt(new_vp->v_fs_e)) == NULL)
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panic("advance: vmnt not found");
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new_vp->v_vmnt = vmp;
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new_vp->v_dev = vmp->m_dev;
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new_vp->v_fs_count = 1;
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vp = new_vp;
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}
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dup_vnode(vp);
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if (do_downgrade) {
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/* Only downgrade a lock if we managed to lock it in the first place */
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*(resolve->l_vnode) = vp;
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if (initial_locktype != resolve->l_vnode_lock)
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tll_downgrade(&vp->v_lock);
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#if LOCK_DEBUG
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if (resolve->l_vnode_lock == VNODE_READ)
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fp->fp_vp_rdlocks++;
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#endif
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}
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return(vp);
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}
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/*===========================================================================*
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* eat_path *
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*===========================================================================*/
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struct vnode *eat_path(resolve, rfp)
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struct lookup *resolve;
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struct fproc *rfp;
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{
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/* Resolve path to a vnode. advance does the actual work. */
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struct vnode *start_dir;
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start_dir = (resolve->l_path[0] == '/' ? rfp->fp_rd : rfp->fp_wd);
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return advance(start_dir, resolve, rfp);
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}
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/*===========================================================================*
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* last_dir *
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*===========================================================================*/
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struct vnode *last_dir(resolve, rfp)
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struct lookup *resolve;
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struct fproc *rfp;
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{
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/* Parse a path, as far as the last directory, fetch the vnode
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* for the last directory into the vnode table, and return a pointer to the
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* vnode. In addition, return the final component of the path in 'string'. If
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* the last directory can't be opened, return NULL and the reason for
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* failure in 'err_code'. We can't parse component by component as that would
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* be too expensive. Alternatively, we cut off the last component of the path,
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* and parse the path up to the penultimate component.
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*/
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size_t len;
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char *cp;
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char dir_entry[NAME_MAX+1];
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struct vnode *start_dir, *res_vp, *sym_vp, *sym_vp_l, *loop_start;
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struct vmnt *sym_vmp = NULL;
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int r, symloop = 0, ret_on_symlink = 0;
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struct lookup symlink;
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*resolve->l_vnode = NULL;
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*resolve->l_vmp = NULL;
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loop_start = NULL;
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sym_vp = NULL;
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ret_on_symlink = !!(resolve->l_flags & PATH_RET_SYMLINK);
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do {
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/* Is the path absolute or relative? Initialize 'start_dir'
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* accordingly. Use loop_start in case we're looping.
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*/
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if (loop_start != NULL)
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start_dir = loop_start;
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else
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start_dir = (resolve->l_path[0] == '/' ? rfp->fp_rd:rfp->fp_wd);
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len = strlen(resolve->l_path);
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/* If path is empty, return ENOENT. */
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if (len == 0) {
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err_code = ENOENT;
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res_vp = NULL;
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break;
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}
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#if !DO_POSIX_PATHNAME_RES
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/* Remove trailing slashes */
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while (len > 1 && resolve->l_path[len-1] == '/') {
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len--;
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resolve->l_path[len]= '\0';
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}
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#endif
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cp = strrchr(resolve->l_path, '/');
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if (cp == NULL) {
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/* Just an entry in the current working directory. Prepend
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* "./" in front of the path and resolve it.
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*/
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if (strlcpy(dir_entry, resolve->l_path, NAME_MAX+1) >= NAME_MAX + 1) {
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err_code = ENAMETOOLONG;
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res_vp = NULL;
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break;
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}
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dir_entry[NAME_MAX] = '\0';
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resolve->l_path[0] = '.';
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resolve->l_path[1] = '\0';
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} else if (cp[1] == '\0') {
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/* Path ends in a slash. The directory entry is '.' */
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strlcpy(dir_entry, ".", NAME_MAX+1);
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} else {
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/* A path name for the directory and a directory entry */
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if (strlcpy(dir_entry, cp+1, NAME_MAX+1) >= NAME_MAX + 1) {
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err_code = ENAMETOOLONG;
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res_vp = NULL;
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break;
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}
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cp[1] = '\0';
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dir_entry[NAME_MAX] = '\0';
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}
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/* Remove trailing slashes */
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while (cp > resolve->l_path && cp[0] == '/') {
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cp[0]= '\0';
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cp--;
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}
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/* Resolve up to and including the last directory of the path. Turn off
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* PATH_RET_SYMLINK, because we do want to follow the symlink in this
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* case. That is, the flag is meant for the actual filename of the path,
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* not the last directory.
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*/
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resolve->l_flags &= ~PATH_RET_SYMLINK;
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if ((res_vp = advance(start_dir, resolve, rfp)) == NULL) {
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break;
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}
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/* If the directory entry is not a symlink we're done now. If it is a
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* symlink, then we're not at the last directory, yet. */
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/* Copy the directory entry back to user_fullpath */
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strlcpy(resolve->l_path, dir_entry, NAME_MAX + 1);
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/* Look up the directory entry, but do not follow the symlink when it
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* is one. Note: depending on the previous advance, we might not be
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* able to lock the resulting vnode. For example, when we look up "./."
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* and request a VNODE_WRITE lock on the result, then the previous
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* advance has "./" locked. The next advance to "." will try to lock
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* the same vnode with a VNODE_READ lock, and fail. When that happens,
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* sym_vp_l will be NULL and we must not unlock the vnode. If we would
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* unlock, we actually unlock the vnode locked by the previous advance.
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*/
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lookup_init(&symlink, resolve->l_path,
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resolve->l_flags|PATH_RET_SYMLINK, &sym_vmp, &sym_vp_l);
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symlink.l_vmnt_lock = VMNT_READ;
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symlink.l_vnode_lock = VNODE_READ;
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sym_vp = advance(res_vp, &symlink, rfp);
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if (sym_vp == NULL) break;
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if (S_ISLNK(sym_vp->v_mode)) {
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/* Last component is a symlink, but if we've been asked to not
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* resolve it, return now.
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*/
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if (ret_on_symlink) {
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break;
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}
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r = req_rdlink(sym_vp->v_fs_e, sym_vp->v_inode_nr, NONE,
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(vir_bytes) resolve->l_path, PATH_MAX - 1, 1);
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if (r < 0) {
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/* Failed to read link */
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err_code = r;
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unlock_vnode(res_vp);
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unlock_vmnt(*resolve->l_vmp);
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put_vnode(res_vp);
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*resolve->l_vmp = NULL;
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*resolve->l_vnode = NULL;
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res_vp = NULL;
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break;
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}
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resolve->l_path[r] = '\0';
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if (strrchr(resolve->l_path, '/') != NULL) {
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if (sym_vp_l != NULL)
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unlock_vnode(sym_vp);
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unlock_vmnt(*resolve->l_vmp);
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if (sym_vmp != NULL)
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unlock_vmnt(sym_vmp);
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*resolve->l_vmp = NULL;
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put_vnode(sym_vp);
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sym_vp = NULL;
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symloop++;
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/* Relative symlinks are relative to res_vp, not cwd */
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if (resolve->l_path[0] != '/') {
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loop_start = res_vp;
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} else {
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/* Absolute symlink, forget about res_vp */
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unlock_vnode(res_vp);
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put_vnode(res_vp);
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}
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continue;
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}
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} else {
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symloop = 0; /* Not a symlink, so restart counting */
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/* If we're crossing a mount point, return root node of mount
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* point on which the file resides. That's the 'real' last
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* dir that holds the file we're looking for.
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*/
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if (sym_vp->v_fs_e != res_vp->v_fs_e) {
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assert(sym_vmp != NULL);
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/* Unlock final file, it might have wrong lock types */
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if (sym_vp_l != NULL)
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unlock_vnode(sym_vp);
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unlock_vmnt(sym_vmp);
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put_vnode(sym_vp);
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sym_vp = NULL;
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/* Also unlock and release erroneous result */
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unlock_vnode(*resolve->l_vnode);
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unlock_vmnt(*resolve->l_vmp);
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put_vnode(res_vp);
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/* Relock vmnt and vnode with correct lock types */
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lock_vmnt(sym_vmp, resolve->l_vmnt_lock);
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lock_vnode(sym_vmp->m_root_node, resolve->l_vnode_lock);
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res_vp = sym_vmp->m_root_node;
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dup_vnode(res_vp);
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*resolve->l_vnode = res_vp;
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*resolve->l_vmp = sym_vmp;
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/* We've effectively resolved the final component, so
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* change it to current directory to prevent future
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* 'advances' of returning erroneous results.
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*/
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strlcpy(dir_entry, ".", NAME_MAX+1);
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}
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}
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break;
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} while (symloop < SYMLOOP_MAX);
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if (symloop >= SYMLOOP_MAX) {
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err_code = ELOOP;
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res_vp = NULL;
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}
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if (sym_vp != NULL) {
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if (sym_vp_l != NULL) {
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unlock_vnode(sym_vp);
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}
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if (sym_vmp != NULL) {
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unlock_vmnt(sym_vmp);
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}
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put_vnode(sym_vp);
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}
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if (loop_start != NULL) {
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unlock_vnode(loop_start);
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put_vnode(loop_start);
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}
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/* Copy the directory entry back to user_fullpath */
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strlcpy(resolve->l_path, dir_entry, NAME_MAX + 1);
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/* Turn PATH_RET_SYMLINK flag back on if it was on */
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if (ret_on_symlink) resolve->l_flags |= PATH_RET_SYMLINK;
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return(res_vp);
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}
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/*===========================================================================*
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* lookup *
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*===========================================================================*/
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static int lookup(start_node, resolve, result_node, rfp)
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struct vnode *start_node;
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struct lookup *resolve;
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node_details_t *result_node;
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struct fproc *rfp;
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{
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/* Resolve a path name relative to start_node. */
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int r, symloop;
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endpoint_t fs_e;
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size_t path_off, path_left_len;
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ino_t dir_ino, root_ino;
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uid_t uid;
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gid_t gid;
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struct vnode *dir_vp;
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struct vmnt *vmp, *vmpres;
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struct lookup_res res;
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tll_access_t mnt_lock_type;
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assert(resolve->l_vmp);
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assert(resolve->l_vnode);
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*(resolve->l_vmp) = vmpres = NULL; /* No vmnt found nor locked yet */
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/* Empty (start) path? */
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if (resolve->l_path[0] == '\0') {
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result_node->inode_nr = 0;
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return(ENOENT);
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}
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if (!rfp->fp_rd || !rfp->fp_wd) {
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printf("VFS: lookup %d: no rd/wd\n", rfp->fp_endpoint);
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return(ENOENT);
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}
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fs_e = start_node->v_fs_e;
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dir_ino = start_node->v_inode_nr;
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vmpres = find_vmnt(fs_e);
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if (vmpres == NULL) return(EIO); /* mountpoint vanished? */
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/* Is the process' root directory on the same partition?,
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* if so, set the chroot directory too. */
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if (rfp->fp_rd->v_dev == rfp->fp_wd->v_dev)
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root_ino = rfp->fp_rd->v_inode_nr;
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else
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root_ino = 0;
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/* Set user and group ids according to the system call */
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uid = (job_call_nr == VFS_ACCESS ? rfp->fp_realuid : rfp->fp_effuid);
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gid = (job_call_nr == VFS_ACCESS ? rfp->fp_realgid : rfp->fp_effgid);
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symloop = 0; /* Number of symlinks seen so far */
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/* Lock vmnt */
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if (resolve->l_vmnt_lock == VMNT_READ)
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mnt_lock_type = VMNT_WRITE;
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else
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mnt_lock_type = resolve->l_vmnt_lock;
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if ((r = lock_vmnt(vmpres, mnt_lock_type)) != OK) {
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if (r == EBUSY) /* vmnt already locked */
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vmpres = NULL;
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else
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return(r);
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}
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*(resolve->l_vmp) = vmpres;
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/* Issue the request */
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r = req_lookup(fs_e, dir_ino, root_ino, uid, gid, resolve, &res, rfp);
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if (r != OK && r != EENTERMOUNT && r != ELEAVEMOUNT && r != ESYMLINK) {
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if (vmpres) unlock_vmnt(vmpres);
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*(resolve->l_vmp) = NULL;
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return(r); /* i.e., an error occured */
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}
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/* While the response is related to mount control set the
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* new requests respectively */
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while (r == EENTERMOUNT || r == ELEAVEMOUNT || r == ESYMLINK) {
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/* Update user_fullpath to reflect what's left to be parsed. */
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path_off = res.char_processed;
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path_left_len = strlen(&resolve->l_path[path_off]);
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memmove(resolve->l_path, &resolve->l_path[path_off], path_left_len);
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resolve->l_path[path_left_len] = '\0'; /* terminate string */
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/* Update the current value of the symloop counter */
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symloop += res.symloop;
|
|
if (symloop > SYMLOOP_MAX) {
|
|
if (vmpres) unlock_vmnt(vmpres);
|
|
*(resolve->l_vmp) = NULL;
|
|
return(ELOOP);
|
|
}
|
|
|
|
/* Symlink encountered with absolute path */
|
|
if (r == ESYMLINK) {
|
|
dir_vp = rfp->fp_rd;
|
|
vmp = NULL;
|
|
} else if (r == EENTERMOUNT) {
|
|
/* Entering a new partition */
|
|
dir_vp = NULL;
|
|
/* Start node is now the mounted partition's root node */
|
|
for (vmp = &vmnt[0]; vmp != &vmnt[NR_MNTS]; ++vmp) {
|
|
if (vmp->m_dev != NO_DEV && vmp->m_mounted_on) {
|
|
if (vmp->m_mounted_on->v_inode_nr == res.inode_nr &&
|
|
vmp->m_mounted_on->v_fs_e == res.fs_e) {
|
|
dir_vp = vmp->m_root_node;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (dir_vp == NULL) {
|
|
printf("VFS: path lookup error; root node not found\n");
|
|
if (vmpres) unlock_vmnt(vmpres);
|
|
*(resolve->l_vmp) = NULL;
|
|
return(EIO);
|
|
}
|
|
} else {
|
|
/* Climbing up mount */
|
|
/* Find the vmnt that represents the partition on
|
|
* which we "climb up". */
|
|
if ((vmp = find_vmnt(res.fs_e)) == NULL) {
|
|
panic("VFS lookup: can't find parent vmnt");
|
|
}
|
|
|
|
/* Make sure that the child FS does not feed a bogus path
|
|
* to the parent FS. That is, when we climb up the tree, we
|
|
* must've encountered ".." in the path, and that is exactly
|
|
* what we're going to feed to the parent */
|
|
if(strncmp(resolve->l_path, "..", 2) != 0 ||
|
|
(resolve->l_path[2] != '\0' && resolve->l_path[2] != '/')) {
|
|
printf("VFS: bogus path: %s\n", resolve->l_path);
|
|
if (vmpres) unlock_vmnt(vmpres);
|
|
*(resolve->l_vmp) = NULL;
|
|
return(ENOENT);
|
|
}
|
|
|
|
/* Start node is the vnode on which the partition is
|
|
* mounted */
|
|
dir_vp = vmp->m_mounted_on;
|
|
}
|
|
|
|
/* Set the starting directories inode number and FS endpoint */
|
|
fs_e = dir_vp->v_fs_e;
|
|
dir_ino = dir_vp->v_inode_nr;
|
|
|
|
/* Is the process' root directory on the same partition?,
|
|
* if so, set the chroot directory too. */
|
|
if (dir_vp->v_dev == rfp->fp_rd->v_dev)
|
|
root_ino = rfp->fp_rd->v_inode_nr;
|
|
else
|
|
root_ino = 0;
|
|
|
|
/* Unlock a previously locked vmnt if locked and lock new vmnt */
|
|
if (vmpres) unlock_vmnt(vmpres);
|
|
vmpres = find_vmnt(fs_e);
|
|
if (vmpres == NULL) return(EIO); /* mount point vanished? */
|
|
if ((r = lock_vmnt(vmpres, mnt_lock_type)) != OK) {
|
|
if (r == EBUSY)
|
|
vmpres = NULL; /* Already locked */
|
|
else
|
|
return(r);
|
|
}
|
|
*(resolve->l_vmp) = vmpres;
|
|
|
|
r = req_lookup(fs_e, dir_ino, root_ino, uid, gid, resolve, &res, rfp);
|
|
|
|
if (r != OK && r != EENTERMOUNT && r != ELEAVEMOUNT && r != ESYMLINK) {
|
|
if (vmpres) unlock_vmnt(vmpres);
|
|
*(resolve->l_vmp) = NULL;
|
|
return(r);
|
|
}
|
|
}
|
|
|
|
if (*(resolve->l_vmp) != NULL && resolve->l_vmnt_lock != mnt_lock_type) {
|
|
/* downgrade VMNT_WRITE to VMNT_READ */
|
|
downgrade_vmnt_lock(*(resolve->l_vmp));
|
|
}
|
|
|
|
/* Fill in response fields */
|
|
result_node->inode_nr = res.inode_nr;
|
|
result_node->fmode = res.fmode;
|
|
result_node->fsize = res.fsize;
|
|
result_node->dev = res.dev;
|
|
result_node->fs_e = res.fs_e;
|
|
result_node->uid = res.uid;
|
|
result_node->gid = res.gid;
|
|
|
|
return(r);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* lookup_init *
|
|
*===========================================================================*/
|
|
void lookup_init(resolve, path, flags, vmp, vp)
|
|
struct lookup *resolve;
|
|
char *path;
|
|
int flags;
|
|
struct vmnt **vmp;
|
|
struct vnode **vp;
|
|
{
|
|
assert(vmp != NULL);
|
|
assert(vp != NULL);
|
|
|
|
resolve->l_path = path;
|
|
resolve->l_flags = flags;
|
|
resolve->l_vmp = vmp;
|
|
resolve->l_vnode = vp;
|
|
resolve->l_vmnt_lock = TLL_NONE;
|
|
resolve->l_vnode_lock = TLL_NONE;
|
|
*vmp = NULL; /* Initialize lookup result to NULL */
|
|
*vp = NULL;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* get_name *
|
|
*===========================================================================*/
|
|
int get_name(dirp, entry, ename)
|
|
struct vnode *dirp;
|
|
struct vnode *entry;
|
|
char ename[NAME_MAX + 1];
|
|
{
|
|
#define DIR_ENTRIES 8
|
|
#define DIR_ENTRY_SIZE (sizeof(struct dirent) + NAME_MAX)
|
|
off_t pos, new_pos;
|
|
int r, consumed, totalbytes, name_len;
|
|
char buf[DIR_ENTRY_SIZE * DIR_ENTRIES];
|
|
struct dirent *cur;
|
|
|
|
pos = 0;
|
|
|
|
if (!S_ISDIR(dirp->v_mode)) return(EBADF);
|
|
|
|
do {
|
|
r = req_getdents(dirp->v_fs_e, dirp->v_inode_nr, pos, buf, sizeof(buf),
|
|
&new_pos, 1);
|
|
|
|
if (r == 0) {
|
|
return(ENOENT); /* end of entries -- matching inode !found */
|
|
} else if (r < 0) {
|
|
return(r); /* error */
|
|
}
|
|
|
|
consumed = 0; /* bytes consumed */
|
|
totalbytes = r; /* number of bytes to consume */
|
|
|
|
do {
|
|
cur = (struct dirent *) (buf + consumed);
|
|
name_len = cur->d_reclen - offsetof(struct dirent, d_name) - 1;
|
|
|
|
if(cur->d_name + name_len+1 > &buf[sizeof(buf)])
|
|
return(EINVAL); /* Rubbish in dir entry */
|
|
if (entry->v_inode_nr == cur->d_fileno) {
|
|
/* found the entry we were looking for */
|
|
int copylen = MIN(name_len + 1, NAME_MAX + 1);
|
|
if (strlcpy(ename, cur->d_name, copylen) >= copylen) {
|
|
return(ENAMETOOLONG);
|
|
}
|
|
ename[NAME_MAX] = '\0';
|
|
return(OK);
|
|
}
|
|
|
|
/* not a match -- move on to the next dirent */
|
|
consumed += cur->d_reclen;
|
|
} while (consumed < totalbytes);
|
|
|
|
pos = new_pos;
|
|
} while (1);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* canonical_path *
|
|
*===========================================================================*/
|
|
int canonical_path(orig_path, rfp)
|
|
char orig_path[PATH_MAX];
|
|
struct fproc *rfp;
|
|
{
|
|
/* Find canonical path of a given path */
|
|
int len = 0;
|
|
int r, symloop = 0;
|
|
struct vnode *dir_vp, *parent_dir;
|
|
struct vmnt *dir_vmp, *parent_vmp;
|
|
char component[NAME_MAX+1]; /* NAME_MAX does /not/ include '\0' */
|
|
char temp_path[PATH_MAX];
|
|
struct lookup resolve;
|
|
|
|
parent_dir = dir_vp = NULL;
|
|
parent_vmp = dir_vmp = NULL;
|
|
strlcpy(temp_path, orig_path, PATH_MAX);
|
|
temp_path[PATH_MAX - 1] = '\0';
|
|
|
|
/* First resolve path to the last directory holding the file */
|
|
do {
|
|
if (dir_vp) {
|
|
unlock_vnode(dir_vp);
|
|
unlock_vmnt(dir_vmp);
|
|
put_vnode(dir_vp);
|
|
}
|
|
|
|
lookup_init(&resolve, temp_path, PATH_NOFLAGS, &dir_vmp, &dir_vp);
|
|
resolve.l_vmnt_lock = VMNT_READ;
|
|
resolve.l_vnode_lock = VNODE_READ;
|
|
if ((dir_vp = last_dir(&resolve, rfp)) == NULL) return(err_code);
|
|
|
|
/* dir_vp points to dir and resolve path now contains only the
|
|
* filename.
|
|
*/
|
|
strlcpy(orig_path, temp_path, NAME_MAX+1); /* Store file name */
|
|
|
|
/* If we're just crossing a mount point, our name has changed to '.' */
|
|
if (!strcmp(orig_path, ".")) orig_path[0] = '\0';
|
|
|
|
/* check if the file is a symlink, if so resolve it */
|
|
r = rdlink_direct(orig_path, temp_path, rfp);
|
|
|
|
if (r <= 0)
|
|
break;
|
|
|
|
/* encountered a symlink -- loop again */
|
|
strlcpy(orig_path, temp_path, PATH_MAX);
|
|
symloop++;
|
|
} while (symloop < SYMLOOP_MAX);
|
|
|
|
if (symloop >= SYMLOOP_MAX) {
|
|
if (dir_vp) {
|
|
unlock_vnode(dir_vp);
|
|
unlock_vmnt(dir_vmp);
|
|
put_vnode(dir_vp);
|
|
}
|
|
return(ELOOP);
|
|
}
|
|
|
|
/* We've got the filename and the actual directory holding the file. From
|
|
* here we start building up the canonical path by climbing up the tree */
|
|
while (dir_vp != rfp->fp_rd) {
|
|
|
|
strlcpy(temp_path, "..", NAME_MAX+1);
|
|
|
|
/* check if we're at the root node of the file system */
|
|
if (dir_vp->v_vmnt->m_root_node == dir_vp) {
|
|
if (dir_vp->v_vmnt->m_mounted_on == NULL) {
|
|
/* Bail out, we can't go any higher */
|
|
break;
|
|
}
|
|
unlock_vnode(dir_vp);
|
|
unlock_vmnt(dir_vmp);
|
|
put_vnode(dir_vp);
|
|
dir_vp = dir_vp->v_vmnt->m_mounted_on;
|
|
dir_vmp = dir_vp->v_vmnt;
|
|
if (lock_vmnt(dir_vmp, VMNT_READ) != OK)
|
|
panic("failed to lock vmnt");
|
|
if (lock_vnode(dir_vp, VNODE_READ) != OK)
|
|
panic("failed to lock vnode");
|
|
dup_vnode(dir_vp);
|
|
}
|
|
|
|
lookup_init(&resolve, temp_path, PATH_NOFLAGS, &parent_vmp,
|
|
&parent_dir);
|
|
resolve.l_vmnt_lock = VMNT_READ;
|
|
resolve.l_vnode_lock = VNODE_READ;
|
|
|
|
if ((parent_dir = advance(dir_vp, &resolve, rfp)) == NULL) {
|
|
unlock_vnode(dir_vp);
|
|
unlock_vmnt(dir_vmp);
|
|
put_vnode(dir_vp);
|
|
return(err_code);
|
|
}
|
|
|
|
/* now we have to retrieve the name of the parent directory */
|
|
if ((r = get_name(parent_dir, dir_vp, component)) != OK) {
|
|
unlock_vnode(parent_dir);
|
|
unlock_vmnt(parent_vmp);
|
|
unlock_vnode(dir_vp);
|
|
unlock_vmnt(dir_vmp);
|
|
put_vnode(parent_dir);
|
|
put_vnode(dir_vp);
|
|
return(r);
|
|
}
|
|
|
|
len += strlen(component) + 1;
|
|
if (len >= PATH_MAX) {
|
|
/* adding the component to orig_path would exceed PATH_MAX */
|
|
unlock_vnode(parent_dir);
|
|
unlock_vmnt(parent_vmp);
|
|
unlock_vnode(dir_vp);
|
|
unlock_vmnt(dir_vmp);
|
|
put_vnode(parent_dir);
|
|
put_vnode(dir_vp);
|
|
return(ENOMEM);
|
|
}
|
|
|
|
/* Store result of component in orig_path. First make space by moving
|
|
* the contents of orig_path to the right. Move strlen + 1 bytes to
|
|
* include the terminating '\0'. Move to strlen + 1 bytes to reserve
|
|
* space for the slash.
|
|
*/
|
|
memmove(orig_path+strlen(component)+1, orig_path, strlen(orig_path)+1);
|
|
/* Copy component into canon_path */
|
|
memmove(orig_path, component, strlen(component));
|
|
/* Put slash into place */
|
|
orig_path[strlen(component)] = '/';
|
|
|
|
/* Store parent_dir result, and continue the loop once more */
|
|
unlock_vnode(dir_vp);
|
|
unlock_vmnt(dir_vmp);
|
|
put_vnode(dir_vp);
|
|
dir_vp = parent_dir;
|
|
dir_vmp = parent_vmp;
|
|
parent_vmp = NULL;
|
|
}
|
|
|
|
unlock_vmnt(dir_vmp);
|
|
unlock_vnode(dir_vp);
|
|
put_vnode(dir_vp);
|
|
|
|
/* add the leading slash */
|
|
len = strlen(orig_path);
|
|
if (strlen(orig_path) >= PATH_MAX) return(ENAMETOOLONG);
|
|
memmove(orig_path+1, orig_path, len + 1 /* include terminating nul */);
|
|
orig_path[0] = '/';
|
|
|
|
/* remove trailing slash if there is any */
|
|
if (len > 1 && orig_path[len] == '/') orig_path[len] = '\0';
|
|
|
|
return(OK);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* check_perms *
|
|
*===========================================================================*/
|
|
static int check_perms(ep, io_gr, pathlen)
|
|
endpoint_t ep;
|
|
cp_grant_id_t io_gr;
|
|
size_t pathlen;
|
|
{
|
|
int r, slot;
|
|
struct vnode *vp;
|
|
struct vmnt *vmp;
|
|
struct fproc *rfp;
|
|
char canon_path[PATH_MAX];
|
|
struct lookup resolve;
|
|
|
|
if (isokendpt(ep, &slot) != OK) return(EINVAL);
|
|
if (pathlen < UNIX_PATH_MAX || pathlen >= PATH_MAX) return(EINVAL);
|
|
|
|
rfp = &(fproc[slot]);
|
|
r = sys_safecopyfrom(who_e, io_gr, (vir_bytes) 0, (vir_bytes) canon_path,
|
|
pathlen);
|
|
if (r != OK) return(r);
|
|
canon_path[pathlen] = '\0';
|
|
|
|
/* Turn path into canonical path to the socket file */
|
|
if ((r = canonical_path(canon_path, rfp)) != OK) return(r);
|
|
if (strlen(canon_path) >= pathlen) return(ENAMETOOLONG);
|
|
|
|
/* copy canon_path back to the caller */
|
|
r = sys_safecopyto(who_e, (cp_grant_id_t) io_gr, (vir_bytes) 0,
|
|
(vir_bytes) canon_path, pathlen);
|
|
if (r != OK) return(r);
|
|
|
|
/* Now do permissions checking */
|
|
lookup_init(&resolve, canon_path, PATH_NOFLAGS, &vmp, &vp);
|
|
resolve.l_vmnt_lock = VMNT_READ;
|
|
resolve.l_vnode_lock = VNODE_READ;
|
|
if ((vp = eat_path(&resolve, rfp)) == NULL) return(err_code);
|
|
|
|
/* check permissions */
|
|
r = forbidden(rfp, vp, (R_BIT | W_BIT));
|
|
|
|
unlock_vnode(vp);
|
|
unlock_vmnt(vmp);
|
|
|
|
put_vnode(vp);
|
|
return(r);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* do_checkperms *
|
|
*===========================================================================*/
|
|
int do_checkperms(void)
|
|
{
|
|
/* This should be replaced by an ACL check. */
|
|
if (!super_user) return EPERM;
|
|
|
|
return check_perms(job_m_in.VFS_CHECKPERMS_ENDPT,
|
|
job_m_in.VFS_CHECKPERMS_GRANT, (size_t) job_m_in.VFS_CHECKPERMS_COUNT);
|
|
}
|