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-rw-r--r--trans/magic.c367
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diff --git a/trans/magic.c b/trans/magic.c
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+/* A translator for returning FS_RETRY_MAGIC strings.
+
+ Copyright (C) 1999 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <hurd.h>
+#include <hurd/ports.h>
+#include <hurd/trivfs.h>
+#include <hurd/fsys.h>
+#include <version.h>
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <error.h>
+#include <string.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <argp.h>
+#include <argz.h>
+#include <assert.h>
+
+const char *argp_program_version = STANDARD_HURD_VERSION (magic);
+static char args_doc[] = "MAGIC";
+static char doc[] = "A translator that returns the magic retry result MAGIC";
+static const struct argp_option options[] =
+{
+ {"directory", 'd', 0, 0, "Provide virtual (empty) directory node"},
+ {0}
+};
+
+/* The magic string we return for lookups. */
+static char *magic;
+
+static int directory; /* --directory flag */
+
+/* Pre-fab contents of dummy directory for dir_readdir.
+ Set up only under --directory. */
+static void *dirbuf;
+static size_t dirbufsize;
+
+/* Trivfs hooks */
+
+int trivfs_fstype = FSTYPE_DEV;
+int trivfs_fsid = 0;
+
+int trivfs_support_read = 0;
+int trivfs_support_write = 0;
+int trivfs_support_exec = 0;
+
+int trivfs_allow_open = O_READ;
+
+void
+trivfs_modify_stat (struct trivfs_protid *cred, struct stat *st)
+{
+ st->st_size = dirbufsize;
+ st->st_blocks = getpagesize () / S_BLKSIZE;
+
+ st->st_mode = ((st->st_mode & ~S_IFMT & ~ALLPERMS)
+ | S_IFDIR | S_IXUSR|S_IXGRP|S_IXOTH
+ | (st->st_mode & (S_IRUSR|S_IRGRP|S_IROTH)));
+}
+
+error_t
+trivfs_goaway (struct trivfs_control *fsys, int flags)
+{
+ exit (0);
+}
+
+
+/* This hook is used when running without --directory;
+ it circumvents basically all the trivfs machinery. */
+
+static error_t
+magic_getroot (struct trivfs_control *cntl,
+ mach_port_t reply_port,
+ mach_msg_type_name_t reply_port_type,
+ mach_port_t dotdot,
+ uid_t *uids, u_int nuids, uid_t *gids, u_int ngids,
+ int flags,
+ retry_type *do_retry, char *retry_name,
+ mach_port_t *node, mach_msg_type_name_t *node_type)
+{
+ strcpy (retry_name, magic);
+ *do_retry = FS_RETRY_MAGICAL;
+ *node = MACH_PORT_NULL;
+ *node_type = MACH_MSG_TYPE_COPY_SEND;
+ return 0;
+}
+
+/* This hook is used when running with --directory, when
+ we do use all the normal trivfs machinery. We just use
+ the normal trivfs open, but then stash the DOTDOT port
+ in the trivfs_peropen. */
+
+static error_t
+magic_open (struct trivfs_control *cntl,
+ struct iouser *user,
+ mach_port_t dotdot,
+ int flags,
+ mach_port_t realnode,
+ struct trivfs_protid **cred)
+{
+ error_t err = trivfs_open (cntl, user, flags, realnode, cred);
+ if (!err)
+ {
+ (*cred)->po->hook = (void *) dotdot;
+ err = mach_port_mod_refs (mach_task_self (), dotdot,
+ MACH_PORT_RIGHT_SEND, +1);
+ assert_perror (err);
+ err = mach_port_deallocate (mach_task_self (), dotdot);
+ assert_perror (err);
+ }
+ return err;
+}
+
+
+/* Do a directory lookup. */
+
+error_t
+trivfs_S_dir_lookup (struct trivfs_protid *cred,
+ mach_port_t reply, mach_msg_type_name_t reply_type,
+ char *name,
+ int flags,
+ mode_t mode,
+ retry_type *retry_type,
+ char *retry_name,
+ mach_port_t *retrypt,
+ mach_msg_type_name_t *retrypt_type)
+{
+ int perms;
+ error_t err;
+ struct trivfs_protid *newcred;
+ mach_port_t dotdot;
+ struct iouser *user;
+
+ if (!cred)
+ return EOPNOTSUPP;
+
+ if (name[0] != '\0')
+ {
+ if (!directory)
+ return ENOTDIR;
+ else
+ {
+ /* We have a real lookup in the dummy directory.
+ Handle `.' and `..' specially, and anything else
+ gets redirected to the magical retry. */
+
+ while (*name == '/')
+ ++name;
+ while (!strncmp (name, "./", 2))
+ {
+ name += 2;
+ while (*name == '/')
+ ++name;
+ }
+
+ if (!strcmp (name, "..") || !strncmp (name, "../", 3))
+ {
+ name += 2;
+ while (*name == '/')
+ ++name;
+ strcpy (retry_name, name);
+ *retry_type = FS_RETRY_REAUTH;
+ *retrypt = (mach_port_t) cred->po->hook;
+ *retrypt_type = MACH_MSG_TYPE_COPY_SEND;
+ return 0;
+ }
+ else if (name[0] != '\0' && strcmp (name, "."))
+ {
+ char *p = stpcpy (retry_name, magic);
+ *p++ = '/';
+ strcpy (p, name);
+ *retry_type = FS_RETRY_MAGICAL;
+ *retrypt = MACH_PORT_NULL;
+ *retrypt_type = MACH_MSG_TYPE_COPY_SEND;
+ return 0;
+ }
+ }
+ }
+
+ /* This is a null-pathname "reopen" call; do the right thing. */
+
+ /* Burn off flags we don't actually implement */
+ flags &= O_HURD;
+ flags &= ~(O_CREAT|O_EXCL|O_NOLINK|O_NOTRANS);
+
+ /* Validate permissions */
+ if (! trivfs_check_access_hook)
+ file_check_access (cred->realnode, &perms);
+ else
+ (*trivfs_check_access_hook) (cred->po->cntl, cred->user,
+ cred->realnode, &perms);
+ if ((flags & (O_READ|O_WRITE|O_EXEC) & perms)
+ != (flags & (O_READ|O_WRITE|O_EXEC)))
+ return EACCES;
+
+ /* Execute the open */
+
+ dotdot = (mach_port_t) cred->po->hook;
+ user = iohelp_dup_iouser (cred->user);
+ err = magic_open (cred->po->cntl, user, dotdot, flags,
+ cred->realnode, &newcred);
+ if (err)
+ {
+ iohelp_free_iouser (user);
+ return err;
+ }
+ err = mach_port_mod_refs (mach_task_self (), dotdot,
+ MACH_PORT_RIGHT_SEND, +1);
+ assert_perror (err);
+ err = mach_port_mod_refs (mach_task_self (), cred->realnode,
+ MACH_PORT_RIGHT_SEND, +1);
+ assert_perror (err);
+
+ *retry_type = FS_RETRY_NORMAL;
+ *retry_name = '\0';
+ *retrypt = ports_get_right (newcred);
+ *retrypt_type = MACH_MSG_TYPE_MAKE_SEND;
+ ports_port_deref (newcred);
+ return 0;
+}
+
+error_t
+trivfs_S_dir_readdir (struct trivfs_protid *cred,
+ mach_port_t reply, mach_msg_type_name_t reply_type,
+ char **data,
+ u_int *datalen,
+ boolean_t *data_dealloc,
+ int entry,
+ int nentries,
+ vm_size_t bufsiz,
+ int *amount)
+{
+ if (!cred)
+ return EOPNOTSUPP;
+
+ if (entry > 0)
+ {
+ void *p;
+ int i;
+ i = 0;
+ for (p = dirbuf; p < dirbuf + dirbufsize;
+ p += ((struct dirent *) p)->d_reclen)
+ if (++i == entry)
+ break;
+ *data = p;
+ *datalen = dirbuf + dirbufsize - p;
+ *amount = 2 - entry;
+ }
+ else
+ {
+ *data = dirbuf;
+ *datalen = dirbufsize;
+ *amount = 2;
+ }
+
+ *data_dealloc = 0;
+ return 0;
+}
+
+
+
+static error_t
+parse_opt (int opt, char *arg, struct argp_state *state)
+{
+ switch (opt)
+ {
+ case 'd':
+ directory = 1;
+ return 0;
+
+ case ARGP_KEY_NO_ARGS:
+ argp_usage (state);
+ return EINVAL;
+
+ case ARGP_KEY_ARGS:
+ if (state->next != state->argc - 1)
+ {
+ argp_usage (state);
+ return EINVAL;
+ }
+ else
+ {
+ magic = state->argv[state->next];
+ return 0;
+ }
+ break;
+ }
+
+ return ARGP_ERR_UNKNOWN;
+}
+
+error_t
+trivfs_append_args (struct trivfs_control *fsys,
+ char **argz, size_t *argz_len)
+{
+ return ((directory ? argz_add (argz, argz_len, "--directory") : 0)
+ ?: argz_add (argz, argz_len, magic));
+}
+
+int
+main (int argc, char **argv)
+{
+ error_t err;
+ mach_port_t bootstrap;
+ struct trivfs_control *fsys;
+ struct argp argp = { options, parse_opt, args_doc, doc };
+
+ argp_parse (&argp, argc, argv, 0, 0, 0);
+
+ task_get_bootstrap_port (mach_task_self (), &bootstrap);
+ if (bootstrap == MACH_PORT_NULL)
+ error (1, 0, "Must be started as a translator");
+
+ /* Reply to our parent */
+ err = trivfs_startup (bootstrap, 0, 0, 0, 0, 0, &fsys);
+ mach_port_deallocate (mach_task_self (), bootstrap);
+ if (err)
+ error (3, err, "Contacting parent");
+
+ if (directory)
+ {
+ inline struct dirent *add (struct dirent *d, const char *name)
+ {
+ d->d_fileno = 2; /* random */
+ d->d_type = DT_DIR;
+ d->d_namlen = strlen (name);
+ strcpy (d->d_name, name);
+ d->d_name[d->d_namlen] = '\0';
+ d->d_reclen = &d->d_name[d->d_namlen + 1] - (char *) d;
+ d->d_reclen = ((d->d_reclen + __alignof (struct dirent) - 1)
+ & ~(__alignof (struct dirent) - 1));
+ return (struct dirent *) ((char *) d + d->d_reclen);
+ }
+ struct dirent *d;
+ dirbuf = mmap (0, getpagesize (), PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
+ d = add (dirbuf, ".");
+ d = add (d, "..");
+ dirbufsize = (char *) d - (char *) dirbuf;
+
+ trivfs_open_hook = &magic_open;
+ }
+ else
+ trivfs_getroot_hook = &magic_getroot;
+
+ /* Launch. */
+ ports_manage_port_operations_one_thread (fsys->pi.bucket, trivfs_demuxer,
+ 2 * 60 * 1000);
+
+ return 0;
+}
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