#define MSNFS /* HACK HACK */ /* * linux/fs/nfsd/export.c * * NFS exporting and validation. * * We maintain a list of clients, each of which has a list of * exports. To export an fs to a given client, you first have * to create the client entry with NFSCTL_ADDCLIENT, which * creates a client control block and adds it to the hash * table. Then, you call NFSCTL_EXPORT for each fs. * * * Copyright (C) 1995, 1996 Olaf Kirch, */ #include #include #include #include #include #include #include #include #include #define NFSDDBG_FACILITY NFSDDBG_EXPORT #define NFSD_PARANOIA 1 typedef struct svc_client svc_client; typedef struct svc_export svc_export; static svc_export * exp_find(svc_client *clp, kdev_t dev); static svc_export * exp_parent(svc_client *clp, kdev_t dev, struct dentry *dentry); static svc_export * exp_child(svc_client *clp, kdev_t dev, struct dentry *dentry); static void exp_unexport_all(svc_client *clp); static void exp_do_unexport(svc_export *unexp); static svc_client * exp_getclientbyname(char *name); static void exp_freeclient(svc_client *clp); static void exp_unhashclient(svc_client *clp); static int exp_verify_string(char *cp, int max); #define CLIENT_HASHBITS 6 #define CLIENT_HASHMAX (1 << CLIENT_HASHBITS) #define CLIENT_HASHMASK (CLIENT_HASHMAX - 1) #define CLIENT_HASH(a) \ ((((a)>>24) ^ ((a)>>16) ^ ((a)>>8) ^(a)) & CLIENT_HASHMASK) /* XXX: is this adequate for 32bit kdev_t ? */ #define EXPORT_HASH(dev) ((dev) & (NFSCLNT_EXPMAX - 1)) struct svc_clnthash { struct svc_clnthash * h_next; struct in_addr h_addr; struct svc_client * h_client; }; static struct svc_clnthash * clnt_hash[CLIENT_HASHMAX]; static svc_client * clients; static int initialized; static int hash_lock; static int want_lock; static int hash_count; static DECLARE_WAIT_QUEUE_HEAD( hash_wait ); /* * Find a client's export for a device. */ static inline svc_export * exp_find(svc_client *clp, kdev_t dev) { svc_export * exp; exp = clp->cl_export[EXPORT_HASH(dev)]; while (exp && exp->ex_dev != dev) exp = exp->ex_next; return exp; } /* * Find the client's export entry matching xdev/xino. */ svc_export * exp_get(svc_client *clp, kdev_t dev, ino_t ino) { svc_export * exp; if (!clp) return NULL; exp = clp->cl_export[EXPORT_HASH(dev)]; if (exp) do { if (exp->ex_ino == ino && exp->ex_dev == dev) goto out; } while (NULL != (exp = exp->ex_next)); exp = NULL; out: return exp; } /* * Find the export entry for a given dentry. */ static svc_export * exp_parent(svc_client *clp, kdev_t dev, struct dentry *dentry) { svc_export *exp; if (clp == NULL) return NULL; for (exp = clp->cl_export[EXPORT_HASH(dev)]; exp; exp = exp->ex_next) if (is_subdir(dentry, exp->ex_dentry)) break; return exp; } /* * Find the child export entry for a given fs. This function is used * only by the export syscall to keep the export tree consistent. * */ static svc_export * exp_child(svc_client *clp, kdev_t dev, struct dentry *dentry) { svc_export *exp; if (clp == NULL) return NULL; for (exp = clp->cl_export[EXPORT_HASH(dev)]; exp; exp = exp->ex_next) { struct dentry *ndentry = exp->ex_dentry; if (ndentry && is_subdir(ndentry->d_parent, dentry)) break; } return exp; } /* * Export a file system. */ int exp_export(struct nfsctl_export *nxp) { svc_client *clp; svc_export *exp, *parent; svc_export **head; struct nameidata nd; struct inode *inode = NULL; int i, err; kdev_t dev; ino_t ino; /* Consistency check */ err = -EINVAL; if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) || !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX)) goto out; dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n", nxp->ex_client, nxp->ex_path, nxp->ex_dev, (long) nxp->ex_ino, nxp->ex_flags); dev = to_kdev_t(nxp->ex_dev); ino = nxp->ex_ino; /* Try to lock the export table for update */ if ((err = exp_writelock()) < 0) goto out; /* Look up client info */ err = -EINVAL; if (!(clp = exp_getclientbyname(nxp->ex_client))) goto out_unlock; /* * If there's already an export for this file, assume this * is just a flag update. */ if ((exp = exp_get(clp, dev, ino)) != NULL) { exp->ex_flags = nxp->ex_flags; exp->ex_anon_uid = nxp->ex_anon_uid; exp->ex_anon_gid = nxp->ex_anon_gid; err = 0; goto out_unlock; } /* Look up the dentry */ err = 0; if (path_init(nxp->ex_path, LOOKUP_POSITIVE, &nd)) err = path_walk(nxp->ex_path, &nd); if (err) goto out_unlock; inode = nd.dentry->d_inode; err = -EINVAL; if (inode->i_dev != dev || inode->i_ino != nxp->ex_ino) { printk(KERN_DEBUG "exp_export: i_dev = %x, dev = %x\n", inode->i_dev, dev); /* I'm just being paranoid... */ goto finish; } /* We currently export only dirs and regular files. * This is what umountd does. */ err = -ENOTDIR; if (!S_ISDIR(inode->i_mode) && !S_ISREG(inode->i_mode)) goto finish; err = -EINVAL; if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) || (inode->i_sb->s_op->read_inode == NULL && inode->i_sb->s_op->fh_to_dentry == NULL)) { dprintk("exp_export: export of invalid fs type.\n"); goto finish; } if ((parent = exp_child(clp, dev, nd.dentry)) != NULL) { dprintk("exp_export: export not valid (Rule 3).\n"); goto finish; } /* Is this is a sub-export, must be a proper subset of FS */ if ((parent = exp_parent(clp, dev, nd.dentry)) != NULL) { dprintk("exp_export: sub-export not valid (Rule 2).\n"); goto finish; } err = -ENOMEM; if (!(exp = kmalloc(sizeof(*exp), GFP_USER))) goto finish; dprintk("nfsd: created export entry %p for client %p\n", exp, clp); strcpy(exp->ex_path, nxp->ex_path); exp->ex_client = clp; exp->ex_parent = parent; exp->ex_dentry = nd.dentry; exp->ex_mnt = nd.mnt; exp->ex_flags = nxp->ex_flags; exp->ex_dev = dev; exp->ex_ino = ino; exp->ex_anon_uid = nxp->ex_anon_uid; exp->ex_anon_gid = nxp->ex_anon_gid; /* Update parent pointers of all exports */ if (parent) { for (i = 0; i < NFSCLNT_EXPMAX; i++) { svc_export *temp = clp->cl_export[i]; while (temp) { if (temp->ex_parent == parent) temp->ex_parent = exp; temp = temp->ex_next; } } } head = clp->cl_export + EXPORT_HASH(dev); exp->ex_next = *head; *head = exp; err = 0; /* Unlock hashtable */ out_unlock: exp_unlock(); out: return err; /* Release the dentry */ finish: path_release(&nd); goto out_unlock; } /* * Unexport a file system. The export entry has already * been removed from the client's list of exported fs's. */ static void exp_do_unexport(svc_export *unexp) { svc_export *exp; svc_client *clp; struct dentry *dentry; struct vfsmount *mnt; struct inode *inode; int i; /* Update parent pointers. */ clp = unexp->ex_client; for (i = 0; i < NFSCLNT_EXPMAX; i++) { for (exp = clp->cl_export[i]; exp; exp = exp->ex_next) if (exp->ex_parent == unexp) exp->ex_parent = unexp->ex_parent; } dentry = unexp->ex_dentry; mnt = unexp->ex_mnt; inode = dentry->d_inode; if (unexp->ex_dev != inode->i_dev || unexp->ex_ino != inode->i_ino) printk(KERN_WARNING "nfsd: bad dentry in unexport!\n"); dput(dentry); mntput(mnt); kfree(unexp); } /* * Revoke all exports for a given client. * This may look very awkward, but we have to do it this way in order * to avoid race conditions (aka mind the parent pointer). */ static void exp_unexport_all(svc_client *clp) { svc_export *exp; int i; dprintk("unexporting all fs's for clnt %p\n", clp); for (i = 0; i < NFSCLNT_EXPMAX; i++) { exp = clp->cl_export[i]; clp->cl_export[i] = NULL; while (exp) { svc_export *next = exp->ex_next; exp_do_unexport(exp); exp = next; } } } /* * unexport syscall. */ int exp_unexport(struct nfsctl_export *nxp) { svc_client *clp; svc_export **expp, *exp = NULL; int err; /* Consistency check */ if (!exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX)) return -EINVAL; if ((err = exp_writelock()) < 0) goto out; err = -EINVAL; clp = exp_getclientbyname(nxp->ex_client); if (clp) { expp = clp->cl_export + EXPORT_HASH(nxp->ex_dev); while ((exp = *expp) != NULL) { if (exp->ex_dev == nxp->ex_dev) { if (exp->ex_ino == nxp->ex_ino) { *expp = exp->ex_next; exp_do_unexport(exp); err = 0; break; } } expp = &(exp->ex_next); } } exp_unlock(); out: return err; } /* * Obtain the root fh on behalf of a client. * This could be done in user space, but I feel that it adds some safety * since its harder to fool a kernel module than a user space program. */ int exp_rootfh(struct svc_client *clp, kdev_t dev, ino_t ino, char *path, struct knfsd_fh *f, int maxsize) { struct svc_export *exp; struct nameidata nd; struct inode *inode; struct svc_fh fh; int err; err = -EPERM; if (path) { if (path_init(path, LOOKUP_POSITIVE, &nd) && path_walk(path, &nd)) { printk("nfsd: exp_rootfh path not found %s", path); return err; } dev = nd.dentry->d_inode->i_dev; ino = nd.dentry->d_inode->i_ino; dprintk("nfsd: exp_rootfh(%s [%p] %s:%x/%ld)\n", path, nd.dentry, clp->cl_ident, dev, (long) ino); exp = exp_parent(clp, dev, nd.dentry); } else { dprintk("nfsd: exp_rootfh(%s:%x/%ld)\n", clp->cl_ident, dev, (long) ino); if ((exp = exp_get(clp, dev, ino))) { nd.mnt = mntget(exp->ex_mnt); nd.dentry = dget(exp->ex_dentry); } } if (!exp) { dprintk("nfsd: exp_rootfh export not found.\n"); goto out; } inode = nd.dentry->d_inode; if (!inode) { printk("exp_rootfh: Aieee, NULL d_inode\n"); goto out; } if (inode->i_dev != dev || inode->i_ino != ino) { printk("exp_rootfh: Aieee, ino/dev mismatch\n"); printk("exp_rootfh: arg[dev(%x):ino(%ld)]" " inode[dev(%x):ino(%ld)]\n", dev, (long) ino, inode->i_dev, (long) inode->i_ino); } /* * fh must be initialized before calling fh_compose */ fh_init(&fh, maxsize); if (fh_compose(&fh, exp, dget(nd.dentry), NULL)) err = -EINVAL; else err = 0; memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh)); fh_put(&fh); out: if (path) path_release(&nd); return err; } /* * Hashtable locking. Write locks are placed only by user processes * wanting to modify export information. */ void exp_readlock(void) { while (hash_lock || want_lock) sleep_on(&hash_wait); hash_count++; } int exp_writelock(void) { /* fast track */ if (!hash_count && !hash_lock) { lock_it: hash_lock = 1; return 0; } current->sigpending = 0; want_lock++; while (hash_count || hash_lock) { interruptible_sleep_on(&hash_wait); if (signal_pending(current)) break; } want_lock--; /* restore the task's signals */ spin_lock_irq(¤t->sigmask_lock); recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); if (!hash_count && !hash_lock) goto lock_it; return -EINTR; } void exp_unlock(void) { if (!hash_count && !hash_lock) printk(KERN_WARNING "exp_unlock: not locked!\n"); if (hash_count) hash_count--; else hash_lock = 0; wake_up(&hash_wait); } /* * Find a valid client given an inet address. We always move the most * recently used client to the front of the hash chain to speed up * future lookups. * Locking against other processes is the responsibility of the caller. */ struct svc_client * exp_getclient(struct sockaddr_in *sin) { struct svc_clnthash **hp, **head, *tmp; unsigned long addr = sin->sin_addr.s_addr; if (!initialized) return NULL; head = &clnt_hash[CLIENT_HASH(addr)]; for (hp = head; (tmp = *hp) != NULL; hp = &(tmp->h_next)) { if (tmp->h_addr.s_addr == addr) { /* Move client to the front */ if (head != hp) { *hp = tmp->h_next; tmp->h_next = *head; *head = tmp; } return tmp->h_client; } } return NULL; } /* * Find a client given its identifier. */ static svc_client * exp_getclientbyname(char *ident) { svc_client * clp; for (clp = clients; clp; clp = clp->cl_next) { if (!strcmp(clp->cl_ident, ident)) return clp; } return NULL; } struct flags { int flag; char *name[2]; } expflags[] = { { NFSEXP_READONLY, {"ro", "rw"}}, { NFSEXP_INSECURE_PORT, {"insecure", ""}}, { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}}, { NFSEXP_ALLSQUASH, {"all_squash", ""}}, { NFSEXP_ASYNC, {"async", "sync"}}, { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}}, { NFSEXP_UIDMAP, {"uidmap", ""}}, { NFSEXP_KERBEROS, { "kerberos", ""}}, { NFSEXP_SUNSECURE, { "sunsecure", ""}}, { NFSEXP_CROSSMNT, {"nohide", ""}}, { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}}, { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}}, #ifdef MSNFS { NFSEXP_MSNFS, {"msnfs", ""}}, #endif { 0, {"", ""}} }; static int exp_flags(char *buffer, int flag) { int len = 0, first = 0; struct flags *flg = expflags; for (;flg->flag;flg++) { int state = (flg->flag & flag)?0:1; if (!flg->flag) break; if (*flg->name[state]) { len += sprintf(buffer + len, "%s%s", first++?",":"", flg->name[state]); } } return len; } /* mangling borrowed from fs/super.c */ /* Use octal escapes, like mount does, for embedded spaces etc. */ static unsigned char need_escaping[] = { ' ', '\t', '\n', '\\' }; static int mangle(const unsigned char *s, char *buf, int len) { char *sp; int n; sp = buf; while(*s && sp-buf < len-3) { for (n = 0; n < sizeof(need_escaping); n++) { if (*s == need_escaping[n]) { *sp++ = '\\'; *sp++ = '0' + ((*s & 0300) >> 6); *sp++ = '0' + ((*s & 070) >> 3); *sp++ = '0' + (*s & 07); goto next; } } *sp++ = *s; next: s++; } return sp - buf; /* no trailing NUL */ } #define FREEROOM ((int)PAGE_SIZE-200-len) #define MANGLE(s) len += mangle((s), buffer+len, FREEROOM); int exp_procfs_exports(char *buffer, char **start, off_t offset, int length, int *eof, void *data) { struct svc_clnthash **hp, **head, *tmp; struct svc_client *clp; svc_export *exp; off_t pos = 0; off_t begin = 0; int len = 0; int i,j; len += sprintf(buffer, "# Version 1.1\n"); len += sprintf(buffer+len, "# Path Client(Flags) # IPs\n"); for (clp = clients; clp; clp = clp->cl_next) { for (i = 0; i < NFSCLNT_EXPMAX; i++) { exp = clp->cl_export[i]; while (exp) { int first = 0; MANGLE(exp->ex_path); buffer[len++]='\t'; MANGLE(clp->cl_ident); buffer[len++]='('; len += exp_flags(buffer+len, exp->ex_flags); len += sprintf(buffer+len, ") # "); for (j = 0; j < clp->cl_naddr; j++) { struct in_addr addr = clp->cl_addr[j]; head = &clnt_hash[CLIENT_HASH(addr.s_addr)]; for (hp = head; (tmp = *hp) != NULL; hp = &(tmp->h_next)) { if (tmp->h_addr.s_addr == addr.s_addr) { if (first++) len += sprintf(buffer+len, "%s", " "); if (tmp->h_client != clp) len += sprintf(buffer+len, "("); len += sprintf(buffer+len, "%d.%d.%d.%d", htonl(addr.s_addr) >> 24 & 0xff, htonl(addr.s_addr) >> 16 & 0xff, htonl(addr.s_addr) >> 8 & 0xff, htonl(addr.s_addr) >> 0 & 0xff); if (tmp->h_client != clp) len += sprintf(buffer+len, ")"); break; } } } exp = exp->ex_next; buffer[len++]='\n'; pos=begin+len; if(pos offset + length) goto done; } } } *eof = 1; done: *start = buffer + (offset - begin); len -= (offset - begin); if ( len > length ) len = length; return len; } /* * Add or modify a client. * Change requests may involve the list of host addresses. The list of * exports and possibly existing uid maps are left untouched. */ int exp_addclient(struct nfsctl_client *ncp) { struct svc_clnthash * ch[NFSCLNT_ADDRMAX]; svc_client * clp; int i, err, change = 0, ilen; /* First, consistency check. */ err = -EINVAL; if (!(ilen = exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))) goto out; if (ncp->cl_naddr > NFSCLNT_ADDRMAX) goto out; /* Lock the hashtable */ if ((err = exp_writelock()) < 0) goto out; /* First check if this is a change request for a client. */ for (clp = clients; clp; clp = clp->cl_next) if (!strcmp(clp->cl_ident, ncp->cl_ident)) break; err = -ENOMEM; if (clp) { change = 1; } else { if (!(clp = kmalloc(sizeof(*clp), GFP_KERNEL))) goto out_unlock; memset(clp, 0, sizeof(*clp)); dprintk("created client %s (%p)\n", ncp->cl_ident, clp); strcpy(clp->cl_ident, ncp->cl_ident); clp->cl_idlen = ilen; } /* Allocate hash buckets */ for (i = 0; i < ncp->cl_naddr; i++) { ch[i] = kmalloc(sizeof(struct svc_clnthash), GFP_KERNEL); if (!ch[i]) { while (i--) kfree(ch[i]); if (!change) kfree(clp); goto out_unlock; } } /* Copy addresses. */ for (i = 0; i < ncp->cl_naddr; i++) { clp->cl_addr[i] = ncp->cl_addrlist[i]; } clp->cl_naddr = ncp->cl_naddr; /* Remove old client hash entries. */ if (change) exp_unhashclient(clp); /* Insert client into hashtable. */ for (i = 0; i < ncp->cl_naddr; i++) { struct in_addr addr = clp->cl_addr[i]; int hash; hash = CLIENT_HASH(addr.s_addr); ch[i]->h_client = clp; ch[i]->h_addr = addr; ch[i]->h_next = clnt_hash[hash]; clnt_hash[hash] = ch[i]; } if (!change) { clp->cl_next = clients; clients = clp; } err = 0; out_unlock: exp_unlock(); out: return err; } /* * Delete a client given an identifier. */ int exp_delclient(struct nfsctl_client *ncp) { svc_client **clpp, *clp; int err; err = -EINVAL; if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX)) goto out; /* Lock the hashtable */ if ((err = exp_writelock()) < 0) goto out; err = -EINVAL; for (clpp = &clients; (clp = *clpp); clpp = &(clp->cl_next)) if (!strcmp(ncp->cl_ident, clp->cl_ident)) break; if (clp) { *clpp = clp->cl_next; exp_freeclient(clp); err = 0; } exp_unlock(); out: return err; } /* * Free a client. The caller has already removed it from the client list. */ static void exp_freeclient(svc_client *clp) { exp_unhashclient(clp); /* umap_free(&(clp->cl_umap)); */ exp_unexport_all(clp); nfsd_lockd_unexport(clp); kfree (clp); } /* * Remove client from hashtable. We first collect all hashtable * entries and free them in one go. * The hash table must be writelocked by the caller. */ static void exp_unhashclient(svc_client *clp) { struct svc_clnthash **hpp, *hp, *ch[NFSCLNT_ADDRMAX]; int i, count, err; again: err = 0; for (i = 0, count = 0; i < CLIENT_HASHMAX && !err; i++) { hpp = clnt_hash + i; while ((hp = *hpp) && !err) { if (hp->h_client == clp) { *hpp = hp->h_next; ch[count++] = hp; err = (count >= NFSCLNT_ADDRMAX); } else { hpp = &(hp->h_next); } } } if (count != clp->cl_naddr) printk(KERN_WARNING "nfsd: bad address count in freeclient!\n"); if (err) goto again; for (i = 0; i < count; i++) kfree (ch[i]); } /* * Lockd is shutting down and tells us to unregister all clients */ void exp_nlmdetach(void) { struct svc_client *clp; for (clp = clients; clp; clp = clp->cl_next) nfsd_lockd_unexport(clp); } /* * Verify that string is non-empty and does not exceed max length. */ static int exp_verify_string(char *cp, int max) { int i; for (i = 0; i < max; i++) if (!cp[i]) return i; cp[i] = 0; printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp); return 0; } /* * Initialize the exports module. */ void nfsd_export_init(void) { int i; dprintk("nfsd: initializing export module.\n"); if (initialized) return; for (i = 0; i < CLIENT_HASHMAX; i++) clnt_hash[i] = NULL; clients = NULL; initialized = 1; } /* * Shutdown the exports module. */ void nfsd_export_shutdown(void) { int i; dprintk("nfsd: shutting down export module.\n"); if (!initialized) return; if (exp_writelock() < 0) { printk(KERN_WARNING "Weird: hashtable locked in exp_shutdown"); return; } for (i = 0; i < CLIENT_HASHMAX; i++) { while (clnt_hash[i]) exp_freeclient(clnt_hash[i]->h_client); } clients = NULL; /* we may be restarted before the module unloads */ exp_unlock(); dprintk("nfsd: export shutdown complete.\n"); }