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-rw-r--r--hostmux/mux.c401
1 files changed, 401 insertions, 0 deletions
diff --git a/hostmux/mux.c b/hostmux/mux.c
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--- /dev/null
+++ b/hostmux/mux.c
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+/* Root hostmux node
+
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ Written by Miles Bader <miles@gnu.ai.mit.edu>
+ 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 <stddef.h>
+#include <string.h>
+#include <dirent.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+
+#include "hostmux.h"
+
+error_t create_host_node (struct hostmux *mux, struct hostmux_name *name,
+ struct node **node);
+
+/* Returned directory entries are aligned to blocks this many bytes long.
+ Must be a power of two. */
+#define DIRENT_ALIGN 4
+#define DIRENT_NAME_OFFS offsetof (struct dirent, d_name)
+
+/* Length is structure before the name + the name + '\0', all
+ padded to a four-byte alignment. */
+#define DIRENT_LEN(name_len) \
+ ((DIRENT_NAME_OFFS + (name_len) + 1 + (DIRENT_ALIGN - 1)) \
+ & ~(DIRENT_ALIGN - 1))
+
+static error_t lookup_host (struct hostmux *mux, const char *host,
+ struct node **node); /* fwd decl */
+
+/* [root] Directory operations. */
+
+/* Lookup NAME in DIR for USER; set *NODE to the found name upon return. If
+ the name was not found, then return ENOENT. On any error, clear *NODE.
+ (*NODE, if found, should be locked, this call should unlock DIR no matter
+ what.) */
+error_t
+netfs_attempt_lookup (struct iouser *user, struct node *dir,
+ char *name, struct node **node)
+{
+ error_t err;
+
+ if (dir->nn->name)
+ err = ENOTDIR;
+ else
+ err = lookup_host (dir->nn->mux, name, node);
+
+ touch (dir, TOUCH_ATIME);
+
+ mutex_unlock (&dir->lock);
+
+ if (! err)
+ mutex_lock (&(*node)->lock);
+
+ return err;
+}
+
+/* Implement the netfs_get_directs callback as described in
+ <hurd/netfs.h>. */
+error_t
+netfs_get_dirents (struct iouser *cred, struct node *dir,
+ int first_entry, int num_entries, char **data,
+ mach_msg_type_number_t *data_len,
+ vm_size_t max_data_len, int *data_entries)
+{
+ error_t err;
+ int count;
+ size_t size = 0; /* Total size of our return block. */
+ struct hostmux_name *first_name, *nm;
+
+ if (dir->nn->name)
+ return ENOTDIR;
+
+ rwlock_reader_lock (&dir->nn->mux->names_lock);
+
+ /* Find the first entry. */
+ for (first_name = dir->nn->mux->names;
+ first_name && first_entry > 0;
+ first_name = first_name->next)
+ if (first_name->node)
+ first_entry--;
+
+ /* See how much space we need for the result. */
+ for (nm = first_name, count = 0;
+ nm && (num_entries == -1 || count < num_entries);
+ nm = nm->next)
+ if (nm->node)
+ {
+ size_t new_size = size + DIRENT_LEN (strlen (nm->name));
+ if (new_size > max_data_len)
+ break;
+ size = new_size;
+ count++;
+ }
+
+ /* Allocate it. */
+ err = vm_allocate (mach_task_self (), (vm_address_t *) data, size, 1);
+ if (! err)
+ /* Copy out the result. */
+ {
+ char *p = *data;
+
+ *data_len = size;
+ *data_entries = count;
+
+ /* See how much space we need for the result. */
+ for (nm = first_name, count = 0;
+ nm && (num_entries == -1 || count < num_entries);
+ nm = nm->next)
+ if (nm->node)
+ {
+ struct dirent hdr;
+ size_t name_len = strlen (nm->name);
+ size_t sz = DIRENT_LEN (name_len);
+
+ if (sz > size)
+ break;
+ else
+ size -= sz;
+
+ hdr.d_fileno = nm->fileno;
+ hdr.d_reclen = sz;
+ hdr.d_type =
+ (strcmp (nm->canon, nm->name) == 0 ? DT_REG : DT_LNK);
+ hdr.d_namlen = name_len;
+
+ memcpy (p, &hdr, DIRENT_NAME_OFFS);
+ strcpy (p + DIRENT_NAME_OFFS, nm->name);
+ p += sz;
+
+ count++;
+ }
+
+ }
+
+ rwlock_reader_unlock (&dir->nn->mux->names_lock);
+
+ touch (dir, TOUCH_ATIME);
+
+ return err;
+}
+
+/* Host lookup. */
+
+/* Free storage allocated consumed by the host mux name NM, but not the node
+ it points to. */
+static void
+free_name (struct hostmux_name *nm)
+{
+ free ((char *)nm->name);
+ if (nm->name != nm->canon)
+ free ((char *)nm->canon);
+ free (nm);
+}
+
+/* See if there's an existing entry for the name HOST, and if so, return its
+ node in NODE with an additional references. True is returned iff the
+ lookup succeeds. If PURGE is true, then any nodes with a null node are
+ removed. */
+static int
+lookup_cached (struct hostmux *mux, const char *host, int purge,
+ struct node **node)
+{
+ struct hostmux_name *nm = mux->names, **prevl = &mux->names;
+
+ while (nm)
+ {
+ struct hostmux_name *next = nm->next;
+
+ if (strcasecmp (host, nm->name) == 0)
+ {
+ spin_lock (&netfs_node_refcnt_lock);
+ if (nm->node)
+ nm->node->references++;
+ spin_unlock (&netfs_node_refcnt_lock);
+
+ if (nm->node)
+ {
+ *node = nm->node;
+ return 1;
+ }
+ }
+
+ if (purge && !nm->node)
+ {
+ *prevl = nm->next;
+ free_name (nm);
+ }
+ else
+ prevl = &nm->next;
+
+ nm = next;
+ }
+
+ return 0;
+}
+
+/* See if there's an existing entry for the name HOST, and if so, return its
+ node in NODE, with an additional reference, otherwise, create a new node
+ for the host HE as referred to by HOST, and return that instead, with a
+ single reference. The type of node created is either a translator node,
+ if HOST refers to the official name of the host, or a symlink node to the
+ official name, if it doesn't. */
+static error_t
+lookup_hostent (struct hostmux *mux, const char *host, struct hostent *he,
+ struct node **node)
+{
+ error_t err;
+ struct hostmux_name *nm = malloc (sizeof (struct hostmux_name));
+
+ if (! nm)
+ return ENOMEM;
+
+ nm->name = strdup (host);
+ if (strcmp (host, he->h_name) == 0)
+ nm->canon = nm->name;
+ else
+ nm->canon = strdup (he->h_name);
+
+ err = create_host_node (mux, nm, node);
+ if (err)
+ {
+ free_name (nm);
+ return err;
+ }
+
+ rwlock_writer_lock (&mux->names_lock);
+ if (lookup_cached (mux, host, 1, node))
+ /* An entry for HOST has already been created between the time we last
+ looked and now (which is possible because we didn't lock MUX).
+ Just throw away our version and return the one already in the cache. */
+ {
+ rwlock_writer_unlock (&mux->names_lock);
+ nm->node->nn->name = 0; /* Avoid touching the mux name list. */
+ netfs_nrele (nm->node); /* Free the tentative new node. */
+ free_name (nm); /* And the name it was under. */
+ }
+ else
+ /* Enter NM into MUX's list of names, and return the new node. */
+ {
+ nm->fileno = mux->next_fileno++; /* Now that we hold the lock... */
+ nm->next = mux->names;
+ mux->names = nm;
+ rwlock_writer_unlock (&mux->names_lock);
+ }
+
+ return 0;
+}
+
+/* Lookup the host HOST in MUX, and return the resulting node in NODE, with
+ an additional reference, or an error. */
+static error_t
+lookup_host (struct hostmux *mux, const char *host, struct node **node)
+{
+ int was_cached;
+ int h_err;
+ struct hostent _he, *he;
+ struct in_addr inet_addr;
+ char hostent_data[2048]; /* XXX what size should this be???? */
+
+ rwlock_reader_lock (&mux->names_lock);
+ was_cached = lookup_cached (mux, host, 0, node);
+ rwlock_reader_unlock (&mux->names_lock);
+
+ if (was_cached)
+ return 0;
+ else if (inet_aton (host, &inet_addr))
+ {
+ if (gethostbyaddr_r ((char *)&inet_addr, sizeof inet_addr, AF_INET,
+ &_he, hostent_data, sizeof hostent_data,
+ &he, &h_err) == 0)
+ return lookup_hostent (mux, host, he, node);
+ else
+ return ENOENT;
+ }
+ else if (gethostbyname_r (host, &_he, hostent_data, sizeof hostent_data,
+ &he, &h_err) == 0)
+ return lookup_hostent (mux, host, he, node);
+ else
+ return ENOENT;
+}
+
+/* This should sync the entire remote filesystem. If WAIT is set, return
+ only after sync is completely finished. */
+error_t
+netfs_attempt_syncfs (struct iouser *cred, int wait)
+{
+ return 0;
+}
+
+/* This should attempt a chmod call for the user specified by CRED on node
+ NODE, to change the owner to UID and the group to GID. */
+error_t
+netfs_attempt_chown (struct iouser *cred, struct node *node, uid_t uid, uid_t gid)
+{
+ if (node->nn->name)
+ return EOPNOTSUPP;
+ else
+ {
+ struct hostmux *mux = node->nn->mux;
+ error_t err = file_chown (mux->underlying, uid, gid);
+
+ if (! err)
+ {
+ struct hostmux_name *nm;
+
+ /* Change NODE's owner. */
+ mux->stat_template.st_uid = uid;
+ mux->stat_template.st_gid = gid;
+ node->nn_stat.st_uid = uid;
+ node->nn_stat.st_gid = gid;
+
+ /* Change the owner of each leaf node. */
+ rwlock_reader_lock (&mux->names_lock);
+ for (nm = mux->names; nm; nm = nm->next)
+ if (nm->node)
+ {
+ nm->node->nn_stat.st_uid = uid;
+ nm->node->nn_stat.st_gid = gid;
+ }
+ rwlock_reader_unlock (&mux->names_lock);
+
+ touch (node, TOUCH_CTIME);
+ }
+
+ return err;
+ }
+}
+
+/* This should attempt a chauthor call for the user specified by CRED on node
+ NODE, to change the author to AUTHOR. */
+error_t
+netfs_attempt_chauthor (struct iouser *cred, struct node *node, uid_t author)
+{
+ if (node->nn->name)
+ return EOPNOTSUPP;
+ else
+ {
+ struct hostmux *mux = node->nn->mux;
+ error_t err = file_chauthor (mux->underlying, author);
+
+ if (! err)
+ {
+ struct hostmux_name *nm;
+
+ /* Change NODE's owner. */
+ mux->stat_template.st_author = author;
+ node->nn_stat.st_author = author;
+
+ /* Change the owner of each leaf node. */
+ rwlock_reader_lock (&mux->names_lock);
+ for (nm = mux->names; nm; nm = nm->next)
+ if (nm->node)
+ nm->node->nn_stat.st_author = author;
+ rwlock_reader_unlock (&mux->names_lock);
+
+ touch (node, TOUCH_CTIME);
+ }
+
+ return err;
+ }
+}
+
+/* This should attempt a chmod call for the user specified by CRED on 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 *node, mode_t mode)
+{
+ mode &= ~S_ITRANS;
+ if (node->nn->name || ((mode & S_IFMT) != (node->nn_stat.st_mode & S_IFMT)))
+ return EOPNOTSUPP;
+ else
+ {
+ error_t err = file_chmod (node->nn->mux->underlying, mode & ~S_IFMT);
+ if (! err)
+ {
+ node->nn_stat.st_mode = mode;
+ touch (node, TOUCH_CTIME);
+ }
+ return err;
+ }
+}
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