diff options
Diffstat (limited to 'trans/fakeroot.c')
| -rw-r--r-- | trans/fakeroot.c | 925 |
1 files changed, 925 insertions, 0 deletions
diff --git a/trans/fakeroot.c b/trans/fakeroot.c new file mode 100644 index 00000000..c1102343 --- /dev/null +++ b/trans/fakeroot.c @@ -0,0 +1,925 @@ +/* fakeroot -- a translator for faking actions that aren't really permitted + Copyright (C) 2002, 2003, 2008 Free Software Foundation, Inc. + + This program 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. + + This program 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 02111-1307 USA */ + +#include <hurd/netfs.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <argp.h> +#include <error.h> +#include <string.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <cthreads.h> +#include <hurd/ihash.h> +#include <hurd/paths.h> + +#include <version.h> + +const char *argp_program_version = STANDARD_HURD_VERSION (fakeroot); + +char *netfs_server_name = "fakeroot"; +char *netfs_server_version = HURD_VERSION; +int netfs_maxsymlinks = 16; /* arbitrary */ + +static auth_t fakeroot_auth_port; + +struct netnode +{ + hurd_ihash_locp_t idport_locp;/* easy removal pointer in idport ihash */ + mach_port_t idport; /* port from io_identity */ + int openmodes; /* O_READ | O_WRITE | O_EXEC */ + file_t file; /* port on real file */ + + unsigned int faked; +}; + +#define FAKE_UID (1 << 0) +#define FAKE_GID (1 << 1) +#define FAKE_AUTHOR (1 << 2) +#define FAKE_MODE (1 << 3) +#define FAKE_REFERENCE (1 << 4) /* got node_norefs with st_nlink > 0 */ + +struct mutex idport_ihash_lock = MUTEX_INITIALIZER; +struct hurd_ihash idport_ihash + = HURD_IHASH_INITIALIZER (offsetof (struct netnode, idport_locp)); + + +/* Make a new virtual node. Always consumes the ports. */ +static error_t +new_node (file_t file, mach_port_t idport, int locked, int openmodes, + struct node **np) +{ + error_t err; + struct netnode *nn = calloc (1, sizeof *nn); + if (nn == 0) + { + mach_port_deallocate (mach_task_self (), file); + if (idport != MACH_PORT_NULL) + mach_port_deallocate (mach_task_self (), idport); + if (locked) + mutex_unlock (&idport_ihash_lock); + return ENOMEM; + } + nn->file = file; + nn->openmodes = openmodes; + if (idport != MACH_PORT_NULL) + nn->idport = idport; + else + { + ino_t fileno; + mach_port_t fsidport; + assert (!locked); + err = io_identity (file, &nn->idport, &fsidport, &fileno); + if (err) + { + mach_port_deallocate (mach_task_self (), file); + free (nn); + return err; + } + } + *np = netfs_make_node (nn); + if (*np == 0) + { + if (locked) + mutex_unlock (&idport_ihash_lock); + err = ENOMEM; + } + else + { + if (!locked) + mutex_lock (&idport_ihash_lock); + err = hurd_ihash_add (&idport_ihash, nn->idport, *np); + if (!err) + netfs_nref (*np); /* Return a reference to the caller. */ + mutex_unlock (&idport_ihash_lock); + } + if (err) + { + mach_port_deallocate (mach_task_self (), nn->idport); + mach_port_deallocate (mach_task_self (), file); + free (nn); + } + return err; +} + +/* Node NP has no more references; free all its associated storage. */ +void +netfs_node_norefs (struct node *np) +{ + if (np->nn->faked != 0 + && netfs_validate_stat (np, 0) == 0 && np->nn_stat.st_nlink > 0) + { + /* The real node still exists and we have faked some attributes. + We must keep our node alive in core to retain those values. + XXX + For now, we will leak the node if it gets deleted later. + That will keep the underlying file alive with st_nlink=0 + until this fakeroot filesystem dies. One easy solution + would be to scan nodes with references=1 for st_nlink=0 + at some convenient time, periodically or in syncfs. */ + if ((np->nn->faked & FAKE_REFERENCE) == 0) + { + np->nn->faked |= FAKE_REFERENCE; + ++np->references; + } + mutex_unlock (&np->lock); + return; + } + + spin_unlock (&netfs_node_refcnt_lock); /* Avoid deadlock. */ + mutex_lock (&idport_ihash_lock); + spin_lock (&netfs_node_refcnt_lock); + /* Previous holder of this lock might have just got a reference. */ + if (np->references > 0) + { + mutex_unlock (&idport_ihash_lock); + return; + } + hurd_ihash_locp_remove (&idport_ihash, np->nn->idport_locp); + mutex_unlock (&idport_ihash_lock); + mach_port_deallocate (mach_task_self (), np->nn->file); + mach_port_deallocate (mach_task_self (), np->nn->idport); + free (np->nn); + free (np); +} + +/* Given an existing node, make sure it has NEWMODES in its openmodes. + If not null, FILE is a port with those openmodes. */ +static error_t +check_openmodes (struct netnode *nn, int newmodes, file_t file) +{ + error_t err = 0; + + if (newmodes &~ nn->openmodes) + { + /* The user wants openmodes we haven't tried before. */ + + if (file != MACH_PORT_NULL && (nn->openmodes & ~newmodes)) + { + /* Intersecting sets. + We need yet another new peropen on this node. */ + mach_port_deallocate (mach_task_self (), file); + file = MACH_PORT_NULL; + } + if (file == MACH_PORT_NULL); + { + enum retry_type bad_retry; + char bad_retryname[1024]; /* XXX */ + err = dir_lookup (nn->file, "", nn->openmodes | newmodes, 0, + &bad_retry, bad_retryname, &file); + if (!err && (bad_retry != FS_RETRY_NORMAL + || bad_retryname[0] != '\0')) + { + mach_port_deallocate (mach_task_self (), file); + err = EGRATUITOUS; + } + } + if (! err) + { + /* The new port has more openmodes than + the old one. We can just use it now. */ + mach_port_deallocate (mach_task_self (), nn->file); + nn->file = file; + nn->openmodes = newmodes; + } + } + else if (file != MACH_PORT_NULL) + mach_port_deallocate (mach_task_self (), file); + + return err; +} + +/* This is called by netfs_S_fsys_getroot. */ +error_t +netfs_check_open_permissions (struct iouser *user, struct node *np, + int flags, int newnode) +{ + return check_openmodes (np->nn, flags & (O_RDWR|O_EXEC), MACH_PORT_NULL); +} + +error_t +netfs_S_dir_lookup (struct protid *diruser, + char *filename, + int flags, + mode_t mode, + retry_type *do_retry, + char *retry_name, + mach_port_t *retry_port, + mach_msg_type_name_t *retry_port_type) +{ + struct node *dnp, *np; + error_t err; + struct protid *newpi; + struct iouser *user; + mach_port_t file; + mach_port_t idport, fsidport; + ino_t fileno; + + if (!diruser) + return EOPNOTSUPP; + + dnp = diruser->po->np; + err = dir_lookup (dnp->nn->file, filename, + flags & (O_NOLINK|O_RDWR|O_EXEC|O_CREAT|O_EXCL|O_NONBLOCK), + mode, do_retry, retry_name, &file); + if (err) + return err; + + switch (*do_retry) + { + case FS_RETRY_REAUTH: + { + mach_port_t ref = mach_reply_port (); + err = io_reauthenticate (file, ref, MACH_MSG_TYPE_MAKE_SEND); + if (! err) + { + mach_port_deallocate (mach_task_self (), file); + err = auth_user_authenticate (fakeroot_auth_port, ref, + MACH_MSG_TYPE_MAKE_SEND, + retry_port); + } + mach_port_destroy (mach_task_self (), ref); + if (err) + return err; + } + *do_retry = FS_RETRY_NORMAL; + /*FALLTHROUGH*/ + + case FS_RETRY_NORMAL: + case FS_RETRY_MAGICAL: + default: + if (file == MACH_PORT_NULL) + { + *retry_port = MACH_PORT_NULL; + *retry_port_type = MACH_MSG_TYPE_COPY_SEND; + return 0; + } + break; + } + + /* We have a new port to an underlying node. + Find or make our corresponding virtual node. */ + + np = 0; + err = io_identity (file, &idport, &fsidport, &fileno); + if (err) + mach_port_deallocate (mach_task_self (), file); + else + { + mach_port_deallocate (mach_task_self (), fsidport); + if (fsidport == netfs_fsys_identity) + { + /* Talking to ourselves! We just looked up one of our + own nodes. Find the node and return it. */ + struct protid *cred + = ports_lookup_port (netfs_port_bucket, file, + netfs_protid_class); + mach_port_deallocate (mach_task_self (), idport); + mach_port_deallocate (mach_task_self (), file); + if (cred == 0) + return EGRATUITOUS; + np = cred->po->np; + netfs_nref (np); + ports_port_deref (cred); + } + else + { + mutex_lock (&idport_ihash_lock); + np = hurd_ihash_find (&idport_ihash, idport); + if (np != 0) + { + /* We already know about this node. */ + mach_port_deallocate (mach_task_self (), idport); + mutex_lock (&np->lock); + err = check_openmodes (np->nn, (flags & (O_RDWR|O_EXEC)), file); + if (!err) + netfs_nref (np); + mutex_unlock (&np->lock); + mutex_unlock (&idport_ihash_lock); + } + else + err = new_node (file, idport, 1, flags, &np); + } + } + if (err) + return err; + + if (retry_name[0] == '\0' && *do_retry == FS_RETRY_NORMAL) + flags &= ~(O_CREAT|O_EXCL|O_NOLINK|O_NOTRANS|O_NONBLOCK); + else + flags = 0; + + err = iohelp_dup_iouser (&user, diruser->user); + if (!err) + { + newpi = netfs_make_protid (netfs_make_peropen (np, flags, diruser->po), + user); + if (! newpi) + { + iohelp_free_iouser (user); + err = errno; + } + else + { + *retry_port = ports_get_right (newpi); + *retry_port_type = MACH_MSG_TYPE_MAKE_SEND; + ports_port_deref (newpi); + } + } + + netfs_nrele (np); + return err; +} + +/* These callbacks are used only by the standard netfs_S_dir_lookup, + which we do not use. But the shared library requires us to define them. */ +error_t +netfs_attempt_lookup (struct iouser *user, struct node *dir, + char *name, struct node **np) +{ + assert (! "should not be here"); + return EIEIO; +} + +error_t +netfs_attempt_create_file (struct iouser *user, struct node *dir, + char *name, mode_t mode, struct node **np) +{ + assert (! "should not be here"); + return EIEIO; +} + +/* Make sure that NP->nn_stat is filled with the most current information. + CRED identifies the user responsible for the operation. NP is locked. */ +error_t +netfs_validate_stat (struct node *np, struct iouser *cred) +{ + struct stat st; + error_t err = io_stat (np->nn->file, &st); + if (err) + return err; + + if (np->nn->faked & FAKE_UID) + st.st_uid = np->nn_stat.st_uid; + if (np->nn->faked & FAKE_GID) + st.st_gid = np->nn_stat.st_gid; + if (np->nn->faked & FAKE_AUTHOR) + st.st_author = np->nn_stat.st_author; + if (np->nn->faked & FAKE_MODE) + st.st_mode = np->nn_stat.st_mode; + + np->nn_stat = st; + np->nn_translated = S_ISLNK (st.st_mode) ? S_IFLNK : 0; + + return 0; +} + +error_t +netfs_attempt_chown (struct iouser *cred, struct node *np, + uid_t uid, uid_t gid) +{ + if (uid != -1) + { + np->nn->faked |= FAKE_UID; + np->nn_stat.st_uid = uid; + } + if (gid != -1) + { + np->nn->faked |= FAKE_GID; + np->nn_stat.st_gid = gid; + } + return 0; +} + +error_t +netfs_attempt_chauthor (struct iouser *cred, struct node *np, uid_t author) +{ + np->nn->faked |= FAKE_AUTHOR; + np->nn_stat.st_author = author; + return 0; +} + +/* Return the mode that the real underlying file should have if the + fake mode is being set to MODE. We always give ourselves read and + write permission so that we can open the file as root would be able + to. We give ourselves execute permission iff any execute bit is + set in the fake mode. */ +static inline mode_t +real_from_fake_mode (mode_t mode) +{ + return mode | S_IREAD | S_IWRITE | (((mode << 3) | (mode << 6)) & S_IEXEC); +} + +/* This should attempt a chmod call for the user specified by CRED on + locked node NODE, to change the mode to MODE. Unlike the normal Unix + and Hurd meaning of chmod, this function is also used to attempt to + change files into other types. If such a transition is attempted which + is impossible, then return EOPNOTSUPP. */ +error_t +netfs_attempt_chmod (struct iouser *cred, struct node *np, mode_t mode) +{ + if ((mode & S_IFMT) == 0) + mode |= np->nn_stat.st_mode & S_IFMT; + if ((mode & S_IFMT) != (np->nn_stat.st_mode & S_IFMT)) + return EOPNOTSUPP; + if (((mode | (mode << 3) | (mode << 6)) + ^ (np->nn_stat.st_mode | (np->nn_stat.st_mode << 3) + | (np->nn_stat.st_mode << 6))) + & S_IEXEC) + { + /* We are changing the executable bit, so this is not all fake. We + don't bother with error checking since the fake mode change should + always succeed--worst case a later open will get EACCES. */ + (void) file_chmod (np->nn->file, real_from_fake_mode (mode)); + } + np->nn->faked |= FAKE_MODE; + np->nn_stat.st_mode = mode; + return 0; +} + +/* The user must define this function. Attempt to turn locked node NP + (user CRED) into a symlink with target NAME. */ +error_t +netfs_attempt_mksymlink (struct iouser *cred, struct node *np, char *name) +{ + int namelen = strlen (name) + 1; + char trans[sizeof _HURD_SYMLINK + namelen]; + memcpy (trans, _HURD_SYMLINK, sizeof _HURD_SYMLINK); + memcpy (&trans[sizeof _HURD_SYMLINK], name, namelen); + return file_set_translator (np->nn->file, + FS_TRANS_EXCL|FS_TRANS_SET, + FS_TRANS_EXCL|FS_TRANS_SET, 0, + trans, sizeof trans, + MACH_PORT_NULL, MACH_MSG_TYPE_COPY_SEND); +} + +error_t +netfs_attempt_mkdev (struct iouser *cred, struct node *np, + mode_t type, dev_t indexes) +{ + char *trans = 0; + int translen = asprintf (&trans, "%s%c%d%c%d", + S_ISCHR (type) ? _HURD_CHRDEV : _HURD_BLKDEV, + '\0', major (indexes), '\0', minor (indexes)); + if (trans == 0) + return ENOMEM; + else + { + error_t err = file_set_translator (np->nn->file, + FS_TRANS_EXCL|FS_TRANS_SET, + FS_TRANS_EXCL|FS_TRANS_SET, 0, + trans, translen + 1, + MACH_PORT_NULL, + MACH_MSG_TYPE_COPY_SEND); + free (trans); + return err; + } +} + +error_t +netfs_attempt_chflags (struct iouser *cred, struct node *np, int flags) +{ + return file_chflags (np->nn->file, flags); +} + +error_t +netfs_attempt_utimes (struct iouser *cred, struct node *np, + struct timespec *atime, struct timespec *mtime) +{ + union tv + { + struct timeval tv; + time_value_t tvt; + }; + union tv a, m; + if (atime) + { + TIMESPEC_TO_TIMEVAL (&a.tv, atime); + } + else + a.tv.tv_sec = a.tv.tv_usec = -1; + if (mtime) + { + TIMESPEC_TO_TIMEVAL (&m.tv, mtime); + } + else + m.tv.tv_sec = m.tv.tv_usec = -1; + + return file_utimes (np->nn->file, a.tvt, m.tvt); +} + +error_t +netfs_attempt_set_size (struct iouser *cred, struct node *np, off_t size) +{ + return file_set_size (np->nn->file, size); +} + +error_t +netfs_attempt_statfs (struct iouser *cred, struct node *np, struct statfs *st) +{ + return file_statfs (np->nn->file, st); +} + +error_t +netfs_attempt_sync (struct iouser *cred, struct node *np, int wait) +{ + return file_sync (np->nn->file, wait, 0); +} + +error_t +netfs_attempt_syncfs (struct iouser *cred, int wait) +{ + return 0; +} + +error_t +netfs_attempt_mkdir (struct iouser *user, struct node *dir, + char *name, mode_t mode) +{ + return dir_mkdir (dir->nn->file, name, mode | S_IRWXU); +} + + +/* XXX + Removing a node should mark the netnode so that it is GC'd when + it has no hard refs. + */ + +error_t +netfs_attempt_unlink (struct iouser *user, struct node *dir, char *name) +{ + return dir_unlink (dir->nn->file, name); +} + +error_t +netfs_attempt_rename (struct iouser *user, struct node *fromdir, + char *fromname, struct node *todir, + char *toname, int excl) +{ + return dir_rename (fromdir->nn->file, fromname, + todir->nn->file, toname, excl); +} + +error_t +netfs_attempt_rmdir (struct iouser *user, + struct node *dir, char *name) +{ + return dir_rmdir (dir->nn->file, name); +} + +error_t +netfs_attempt_link (struct iouser *user, struct node *dir, + struct node *file, char *name, int excl) +{ + return dir_link (dir->nn->file, file->nn->file, name, excl); +} + +error_t +netfs_attempt_mkfile (struct iouser *user, struct node *dir, + mode_t mode, struct node **np) +{ + file_t newfile; + error_t err = dir_mkfile (dir->nn->file, O_RDWR|O_EXEC, + real_from_fake_mode (mode), &newfile); + mutex_unlock (&dir->lock); + if (err == 0) + err = new_node (newfile, MACH_PORT_NULL, 0, O_RDWR|O_EXEC, np); + return err; +} + +error_t +netfs_attempt_readlink (struct iouser *user, struct node *np, char *buf) +{ + char transbuf[sizeof _HURD_SYMLINK + np->nn_stat.st_size + 1]; + char *trans = transbuf; + size_t translen = sizeof transbuf; + error_t err = file_get_translator (np->nn->file, &trans, &translen); + if (err == 0) + { + if (translen < sizeof _HURD_SYMLINK + || memcmp (trans, _HURD_SYMLINK, sizeof _HURD_SYMLINK) != 0) + err = EINVAL; + else + { + assert (translen <= sizeof _HURD_SYMLINK + np->nn_stat.st_size + 1); + memcpy (buf, &trans[sizeof _HURD_SYMLINK], + translen - sizeof _HURD_SYMLINK); + } + if (trans != transbuf) + munmap (trans, translen); + } + return err; +} + +error_t +netfs_attempt_read (struct iouser *cred, struct node *np, + off_t offset, size_t *len, void *data) +{ + char *buf = data; + error_t err = io_read (np->nn->file, &buf, len, offset, *len); + if (err == 0 && buf != data) + { + memcpy (data, buf, *len); + munmap (buf, *len); + } + return err; +} + +error_t +netfs_attempt_write (struct iouser *cred, struct node *np, + off_t offset, size_t *len, void *data) +{ + return io_write (np->nn->file, data, *len, offset, len); +} + +error_t +netfs_report_access (struct iouser *cred, struct node *np, int *types) +{ + *types = O_RDWR|O_EXEC; + return 0; +} + +error_t +netfs_get_dirents (struct iouser *cred, struct node *dir, + int entry, int nentries, char **data, + mach_msg_type_number_t *datacnt, + vm_size_t bufsize, int *amt) +{ + return dir_readdir (dir->nn->file, data, datacnt, + entry, nentries, bufsize, amt); +} + +error_t +netfs_file_get_storage_info (struct iouser *cred, + struct node *np, + mach_port_t **ports, + mach_msg_type_name_t *ports_type, + mach_msg_type_number_t *num_ports, + int **ints, + mach_msg_type_number_t *num_ints, + off_t **offsets, + mach_msg_type_number_t *num_offsets, + char **data, + mach_msg_type_number_t *data_len) +{ + *ports_type = MACH_MSG_TYPE_MOVE_SEND; + return file_get_storage_info (np->nn->file, + ports, num_ports, + ints, num_ints, + offsets, num_offsets, + data, data_len); +} + +kern_return_t +netfs_S_file_exec (struct protid *user, + task_t task, + int flags, + char *argv, + size_t argvlen, + char *envp, + size_t envplen, + mach_port_t *fds, + size_t fdslen, + mach_port_t *portarray, + size_t portarraylen, + int *intarray, + size_t intarraylen, + mach_port_t *deallocnames, + size_t deallocnameslen, + mach_port_t *destroynames, + size_t destroynameslen) +{ + error_t err; + file_t file; + + if (!user) + return EOPNOTSUPP; + + mutex_lock (&user->po->np->lock); + err = check_openmodes (user->po->np->nn, O_EXEC, MACH_PORT_NULL); + file = user->po->np->nn->file; + if (!err) + err = mach_port_mod_refs (mach_task_self (), + file, MACH_PORT_RIGHT_SEND, 1); + mutex_unlock (&user->po->np->lock); + + if (!err) + { + /* We cannot use MACH_MSG_TYPE_MOVE_SEND because we might need to + retry an interrupted call that would have consumed the rights. */ + err = file_exec (user->po->np->nn->file, task, flags, argv, argvlen, + envp, envplen, fds, MACH_MSG_TYPE_COPY_SEND, fdslen, + portarray, MACH_MSG_TYPE_COPY_SEND, portarraylen, + intarray, intarraylen, deallocnames, deallocnameslen, + destroynames, destroynameslen); + mach_port_deallocate (mach_task_self (), file); + } + + if (err == 0) + { + size_t i; + mach_port_deallocate (mach_task_self (), task); + for (i = 0; i < fdslen; ++i) + mach_port_deallocate (mach_task_self (), fds[i]); + for (i = 0; i < portarraylen; ++i) + mach_port_deallocate (mach_task_self (), portarray[i]); + } + return err; +} + +error_t +netfs_S_io_map (struct protid *user, + mach_port_t *rdobj, mach_msg_type_name_t *rdobjtype, + mach_port_t *wrobj, mach_msg_type_name_t *wrobjtype) +{ + error_t err; + + if (!user) + return EOPNOTSUPP; + *rdobjtype = *wrobjtype = MACH_MSG_TYPE_MOVE_SEND; + + mutex_lock (&user->po->np->lock); + err = io_map (user->po->np->nn->file, rdobj, wrobj); + mutex_unlock (&user->po->np->lock); + return err; +} + +error_t +netfs_S_io_map_cntl (struct protid *user, + mach_port_t *obj, + mach_msg_type_name_t *objtype) +{ + error_t err; + + if (!user) + return EOPNOTSUPP; + *objtype = MACH_MSG_TYPE_MOVE_SEND; + + mutex_lock (&user->po->np->lock); + err = io_map_cntl (user->po->np->nn->file, obj); + mutex_unlock (&user->po->np->lock); + return err; +} + +#define NETFS_S_SIMPLE(name) \ +error_t \ +netfs_S_##name (struct protid *user) \ +{ \ + error_t err; \ + \ + if (!user) \ + return EOPNOTSUPP; \ + \ + mutex_lock (&user->po->np->lock); \ + err = name (user->po->np->nn->file); \ + mutex_unlock (&user->po->np->lock); \ + return err; \ +} + +NETFS_S_SIMPLE (io_get_conch) +NETFS_S_SIMPLE (io_release_conch) +NETFS_S_SIMPLE (io_eofnotify) +NETFS_S_SIMPLE (io_readnotify) +NETFS_S_SIMPLE (io_readsleep) +NETFS_S_SIMPLE (io_sigio) + +error_t +netfs_S_io_prenotify (struct protid *user, + vm_offset_t start, vm_offset_t stop) +{ + error_t err; + + if (!user) + return EOPNOTSUPP; + + mutex_lock (&user->po->np->lock); + err = io_prenotify (user->po->np->nn->file, start, stop); + mutex_unlock (&user->po->np->lock); + return err; +} + +error_t +netfs_S_io_postnotify (struct protid *user, + vm_offset_t start, vm_offset_t stop) +{ + error_t err; + + if (!user) + return EOPNOTSUPP; + + mutex_lock (&user->po->np->lock); + err = io_postnotify (user->po->np->nn->file, start, stop); + mutex_unlock (&user->po->np->lock); + return err; +} + +/* This overrides the library's definition. */ +int +netfs_demuxer (mach_msg_header_t *inp, + mach_msg_header_t *outp) +{ + int netfs_fs_server (mach_msg_header_t *, mach_msg_header_t *); + int netfs_io_server (mach_msg_header_t *, mach_msg_header_t *); + int netfs_fsys_server (mach_msg_header_t *, mach_msg_header_t *); + int netfs_ifsock_server (mach_msg_header_t *, mach_msg_header_t *); + + if (netfs_io_server (inp, outp) + || netfs_fs_server (inp, outp) + || ports_notify_server (inp, outp) + || netfs_fsys_server (inp, outp) + /* XXX we should intercept interrupt_operation and do + the ports_S_interrupt_operation work as well as + sending an interrupt_operation to the underlying file. + */ + || ports_interrupt_server (inp, outp)) + return 1; + else + { + /* We didn't recognize the message ID, so pass the message through + unchanged to the underlying file. */ + struct protid *cred = ports_lookup_port (netfs_port_bucket, + inp->msgh_local_port, + netfs_protid_class); + if (cred == 0) + /* This must be an unknown message on our fsys control port. */ + return 0; + else + { + error_t err; + assert (MACH_MSGH_BITS_LOCAL (inp->msgh_bits) + == MACH_MSG_TYPE_MOVE_SEND); + inp->msgh_bits = (inp->msgh_bits & MACH_MSGH_BITS_COMPLEX) + | MACH_MSGH_BITS (MACH_MSG_TYPE_COPY_SEND, + MACH_MSGH_BITS_REMOTE (inp->msgh_bits)); + inp->msgh_local_port = inp->msgh_remote_port; /* reply port */ + inp->msgh_remote_port = cred->po->np->nn->file; + err = mach_msg (inp, MACH_SEND_MSG, inp->msgh_size, 0, + MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, + MACH_PORT_NULL); + assert_perror (err); /* XXX should synthesize reply */ + ports_port_deref (cred); + return 1; + } + } +} + + +int +main (int argc, char **argv) +{ + error_t err; + mach_port_t bootstrap; + + struct argp argp = { NULL, NULL, NULL, "\ +A translator for faking privileged access to an underlying filesystem.\v\ +This translator appears to give transparent access to the underlying \ +directory node. However, all accesses are made using the credentials \ +of the translator regardless of the client and the translator fakes \ +success for chown and chmod operations that only root could actually do, \ +reporting the faked IDs and modes in later stat calls, and allows \ +any user to open nodes regardless of permissions as is done for root." }; + + /* Parse our command line arguments (all none of them). */ + argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, 0); + + fakeroot_auth_port = getauth (); + + task_get_bootstrap_port (mach_task_self (), &bootstrap); + netfs_init (); + + /* Get our underlying node (we presume it's a directory) and use + that to make the root node of the filesystem. */ + err = new_node (netfs_startup (bootstrap, O_READ), MACH_PORT_NULL, 0, O_READ, + &netfs_root_node); + if (err) + error (5, err, "Cannot create root node"); + + err = netfs_validate_stat (netfs_root_node, 0); + if (err) + error (6, err, "Cannot stat underlying node"); + + netfs_root_node->nn_stat.st_mode &= ~(S_IPTRANS | S_IATRANS); + netfs_root_node->nn_stat.st_mode |= S_IROOT; + netfs_root_node->nn->faked |= FAKE_MODE; + + netfs_server_loop (); /* Never returns. */ + + /*NOTREACHED*/ + return 0; +} |