diff options
Diffstat (limited to 'fs/nfsd/export.c')
| -rw-r--r-- | fs/nfsd/export.c | 1329 |
1 files changed, 1329 insertions, 0 deletions
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c new file mode 100644 index 000000000..21e404e7c --- /dev/null +++ b/fs/nfsd/export.c @@ -0,0 +1,1329 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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, <okir@monad.swb.de> + */ + +#include <linux/slab.h> +#include <linux/namei.h> +#include <linux/module.h> +#include <linux/exportfs.h> +#include <linux/sunrpc/svc_xprt.h> + +#include "nfsd.h" +#include "nfsfh.h" +#include "netns.h" +#include "pnfs.h" +#include "filecache.h" +#include "trace.h" + +#define NFSDDBG_FACILITY NFSDDBG_EXPORT + +/* + * We have two caches. + * One maps client+vfsmnt+dentry to export options - the export map + * The other maps client+filehandle-fragment to export options. - the expkey map + * + * The export options are actually stored in the first map, and the + * second map contains a reference to the entry in the first map. + */ + +#define EXPKEY_HASHBITS 8 +#define EXPKEY_HASHMAX (1 << EXPKEY_HASHBITS) +#define EXPKEY_HASHMASK (EXPKEY_HASHMAX -1) + +static void expkey_put(struct kref *ref) +{ + struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref); + + if (test_bit(CACHE_VALID, &key->h.flags) && + !test_bit(CACHE_NEGATIVE, &key->h.flags)) + path_put(&key->ek_path); + auth_domain_put(key->ek_client); + kfree_rcu(key, ek_rcu); +} + +static int expkey_upcall(struct cache_detail *cd, struct cache_head *h) +{ + return sunrpc_cache_pipe_upcall(cd, h); +} + +static void expkey_request(struct cache_detail *cd, + struct cache_head *h, + char **bpp, int *blen) +{ + /* client fsidtype \xfsid */ + struct svc_expkey *ek = container_of(h, struct svc_expkey, h); + char type[5]; + + qword_add(bpp, blen, ek->ek_client->name); + snprintf(type, 5, "%d", ek->ek_fsidtype); + qword_add(bpp, blen, type); + qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype)); + (*bpp)[-1] = '\n'; +} + +static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new, + struct svc_expkey *old); +static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *); + +static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen) +{ + /* client fsidtype fsid expiry [path] */ + char *buf; + int len; + struct auth_domain *dom = NULL; + int err; + int fsidtype; + char *ep; + struct svc_expkey key; + struct svc_expkey *ek = NULL; + + if (mesg[mlen - 1] != '\n') + return -EINVAL; + mesg[mlen-1] = 0; + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + err = -ENOMEM; + if (!buf) + goto out; + + err = -EINVAL; + if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0) + goto out; + + err = -ENOENT; + dom = auth_domain_find(buf); + if (!dom) + goto out; + dprintk("found domain %s\n", buf); + + err = -EINVAL; + if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0) + goto out; + fsidtype = simple_strtoul(buf, &ep, 10); + if (*ep) + goto out; + dprintk("found fsidtype %d\n", fsidtype); + if (key_len(fsidtype)==0) /* invalid type */ + goto out; + if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0) + goto out; + dprintk("found fsid length %d\n", len); + if (len != key_len(fsidtype)) + goto out; + + /* OK, we seem to have a valid key */ + key.h.flags = 0; + key.h.expiry_time = get_expiry(&mesg); + if (key.h.expiry_time == 0) + goto out; + + key.ek_client = dom; + key.ek_fsidtype = fsidtype; + memcpy(key.ek_fsid, buf, len); + + ek = svc_expkey_lookup(cd, &key); + err = -ENOMEM; + if (!ek) + goto out; + + /* now we want a pathname, or empty meaning NEGATIVE */ + err = -EINVAL; + len = qword_get(&mesg, buf, PAGE_SIZE); + if (len < 0) + goto out; + dprintk("Path seems to be <%s>\n", buf); + err = 0; + if (len == 0) { + set_bit(CACHE_NEGATIVE, &key.h.flags); + ek = svc_expkey_update(cd, &key, ek); + if (ek) + trace_nfsd_expkey_update(ek, NULL); + else + err = -ENOMEM; + } else { + err = kern_path(buf, 0, &key.ek_path); + if (err) + goto out; + + dprintk("Found the path %s\n", buf); + + ek = svc_expkey_update(cd, &key, ek); + if (ek) + trace_nfsd_expkey_update(ek, buf); + else + err = -ENOMEM; + path_put(&key.ek_path); + } + cache_flush(); + out: + if (ek) + cache_put(&ek->h, cd); + if (dom) + auth_domain_put(dom); + kfree(buf); + return err; +} + +static int expkey_show(struct seq_file *m, + struct cache_detail *cd, + struct cache_head *h) +{ + struct svc_expkey *ek ; + int i; + + if (h ==NULL) { + seq_puts(m, "#domain fsidtype fsid [path]\n"); + return 0; + } + ek = container_of(h, struct svc_expkey, h); + seq_printf(m, "%s %d 0x", ek->ek_client->name, + ek->ek_fsidtype); + for (i=0; i < key_len(ek->ek_fsidtype)/4; i++) + seq_printf(m, "%08x", ek->ek_fsid[i]); + if (test_bit(CACHE_VALID, &h->flags) && + !test_bit(CACHE_NEGATIVE, &h->flags)) { + seq_printf(m, " "); + seq_path(m, &ek->ek_path, "\\ \t\n"); + } + seq_printf(m, "\n"); + return 0; +} + +static inline int expkey_match (struct cache_head *a, struct cache_head *b) +{ + struct svc_expkey *orig = container_of(a, struct svc_expkey, h); + struct svc_expkey *new = container_of(b, struct svc_expkey, h); + + if (orig->ek_fsidtype != new->ek_fsidtype || + orig->ek_client != new->ek_client || + memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0) + return 0; + return 1; +} + +static inline void expkey_init(struct cache_head *cnew, + struct cache_head *citem) +{ + struct svc_expkey *new = container_of(cnew, struct svc_expkey, h); + struct svc_expkey *item = container_of(citem, struct svc_expkey, h); + + kref_get(&item->ek_client->ref); + new->ek_client = item->ek_client; + new->ek_fsidtype = item->ek_fsidtype; + + memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid)); +} + +static inline void expkey_update(struct cache_head *cnew, + struct cache_head *citem) +{ + struct svc_expkey *new = container_of(cnew, struct svc_expkey, h); + struct svc_expkey *item = container_of(citem, struct svc_expkey, h); + + new->ek_path = item->ek_path; + path_get(&item->ek_path); +} + +static struct cache_head *expkey_alloc(void) +{ + struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL); + if (i) + return &i->h; + else + return NULL; +} + +static void expkey_flush(void) +{ + /* + * Take the nfsd_mutex here to ensure that the file cache is not + * destroyed while we're in the middle of flushing. + */ + mutex_lock(&nfsd_mutex); + nfsd_file_cache_purge(current->nsproxy->net_ns); + mutex_unlock(&nfsd_mutex); +} + +static const struct cache_detail svc_expkey_cache_template = { + .owner = THIS_MODULE, + .hash_size = EXPKEY_HASHMAX, + .name = "nfsd.fh", + .cache_put = expkey_put, + .cache_upcall = expkey_upcall, + .cache_request = expkey_request, + .cache_parse = expkey_parse, + .cache_show = expkey_show, + .match = expkey_match, + .init = expkey_init, + .update = expkey_update, + .alloc = expkey_alloc, + .flush = expkey_flush, +}; + +static int +svc_expkey_hash(struct svc_expkey *item) +{ + int hash = item->ek_fsidtype; + char * cp = (char*)item->ek_fsid; + int len = key_len(item->ek_fsidtype); + + hash ^= hash_mem(cp, len, EXPKEY_HASHBITS); + hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS); + hash &= EXPKEY_HASHMASK; + return hash; +} + +static struct svc_expkey * +svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item) +{ + struct cache_head *ch; + int hash = svc_expkey_hash(item); + + ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash); + if (ch) + return container_of(ch, struct svc_expkey, h); + else + return NULL; +} + +static struct svc_expkey * +svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new, + struct svc_expkey *old) +{ + struct cache_head *ch; + int hash = svc_expkey_hash(new); + + ch = sunrpc_cache_update(cd, &new->h, &old->h, hash); + if (ch) + return container_of(ch, struct svc_expkey, h); + else + return NULL; +} + + +#define EXPORT_HASHBITS 8 +#define EXPORT_HASHMAX (1<< EXPORT_HASHBITS) + +static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc) +{ + struct nfsd4_fs_location *locations = fsloc->locations; + int i; + + if (!locations) + return; + + for (i = 0; i < fsloc->locations_count; i++) { + kfree(locations[i].path); + kfree(locations[i].hosts); + } + + kfree(locations); + fsloc->locations = NULL; +} + +static void svc_export_put(struct kref *ref) +{ + struct svc_export *exp = container_of(ref, struct svc_export, h.ref); + path_put(&exp->ex_path); + auth_domain_put(exp->ex_client); + nfsd4_fslocs_free(&exp->ex_fslocs); + kfree(exp->ex_uuid); + kfree_rcu(exp, ex_rcu); +} + +static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h) +{ + return sunrpc_cache_pipe_upcall(cd, h); +} + +static void svc_export_request(struct cache_detail *cd, + struct cache_head *h, + char **bpp, int *blen) +{ + /* client path */ + struct svc_export *exp = container_of(h, struct svc_export, h); + char *pth; + + qword_add(bpp, blen, exp->ex_client->name); + pth = d_path(&exp->ex_path, *bpp, *blen); + if (IS_ERR(pth)) { + /* is this correct? */ + (*bpp)[0] = '\n'; + return; + } + qword_add(bpp, blen, pth); + (*bpp)[-1] = '\n'; +} + +static struct svc_export *svc_export_update(struct svc_export *new, + struct svc_export *old); +static struct svc_export *svc_export_lookup(struct svc_export *); + +static int check_export(struct inode *inode, int *flags, unsigned char *uuid) +{ + + /* + * We currently export only dirs, regular files, and (for v4 + * pseudoroot) symlinks. + */ + if (!S_ISDIR(inode->i_mode) && + !S_ISLNK(inode->i_mode) && + !S_ISREG(inode->i_mode)) + return -ENOTDIR; + + /* + * Mountd should never pass down a writeable V4ROOT export, but, + * just to make sure: + */ + if (*flags & NFSEXP_V4ROOT) + *flags |= NFSEXP_READONLY; + + /* There are two requirements on a filesystem to be exportable. + * 1: We must be able to identify the filesystem from a number. + * either a device number (so FS_REQUIRES_DEV needed) + * or an FSID number (so NFSEXP_FSID or ->uuid is needed). + * 2: We must be able to find an inode from a filehandle. + * This means that s_export_op must be set. + */ + if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) && + !(*flags & NFSEXP_FSID) && + uuid == NULL) { + dprintk("exp_export: export of non-dev fs without fsid\n"); + return -EINVAL; + } + + if (!inode->i_sb->s_export_op || + !inode->i_sb->s_export_op->fh_to_dentry) { + dprintk("exp_export: export of invalid fs type.\n"); + return -EINVAL; + } + + return 0; + +} + +#ifdef CONFIG_NFSD_V4 + +static int +fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc) +{ + int len; + int migrated, i, err; + + /* more than one fsloc */ + if (fsloc->locations) + return -EINVAL; + + /* listsize */ + err = get_uint(mesg, &fsloc->locations_count); + if (err) + return err; + if (fsloc->locations_count > MAX_FS_LOCATIONS) + return -EINVAL; + if (fsloc->locations_count == 0) + return 0; + + fsloc->locations = kcalloc(fsloc->locations_count, + sizeof(struct nfsd4_fs_location), + GFP_KERNEL); + if (!fsloc->locations) + return -ENOMEM; + for (i=0; i < fsloc->locations_count; i++) { + /* colon separated host list */ + err = -EINVAL; + len = qword_get(mesg, buf, PAGE_SIZE); + if (len <= 0) + goto out_free_all; + err = -ENOMEM; + fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL); + if (!fsloc->locations[i].hosts) + goto out_free_all; + err = -EINVAL; + /* slash separated path component list */ + len = qword_get(mesg, buf, PAGE_SIZE); + if (len <= 0) + goto out_free_all; + err = -ENOMEM; + fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL); + if (!fsloc->locations[i].path) + goto out_free_all; + } + /* migrated */ + err = get_int(mesg, &migrated); + if (err) + goto out_free_all; + err = -EINVAL; + if (migrated < 0 || migrated > 1) + goto out_free_all; + fsloc->migrated = migrated; + return 0; +out_free_all: + nfsd4_fslocs_free(fsloc); + return err; +} + +static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp) +{ + struct exp_flavor_info *f; + u32 listsize; + int err; + + /* more than one secinfo */ + if (exp->ex_nflavors) + return -EINVAL; + + err = get_uint(mesg, &listsize); + if (err) + return err; + if (listsize > MAX_SECINFO_LIST) + return -EINVAL; + + for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) { + err = get_uint(mesg, &f->pseudoflavor); + if (err) + return err; + /* + * XXX: It would be nice to also check whether this + * pseudoflavor is supported, so we can discover the + * problem at export time instead of when a client fails + * to authenticate. + */ + err = get_uint(mesg, &f->flags); + if (err) + return err; + /* Only some flags are allowed to differ between flavors: */ + if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags)) + return -EINVAL; + } + exp->ex_nflavors = listsize; + return 0; +} + +#else /* CONFIG_NFSD_V4 */ +static inline int +fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;} +static inline int +secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; } +#endif + +static inline int +nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid) +{ + int len; + + /* more than one uuid */ + if (*puuid) + return -EINVAL; + + /* expect a 16 byte uuid encoded as \xXXXX... */ + len = qword_get(mesg, buf, PAGE_SIZE); + if (len != EX_UUID_LEN) + return -EINVAL; + + *puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL); + if (*puuid == NULL) + return -ENOMEM; + + return 0; +} + +static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) +{ + /* client path expiry [flags anonuid anongid fsid] */ + char *buf; + int len; + int err; + struct auth_domain *dom = NULL; + struct svc_export exp = {}, *expp; + int an_int; + + if (mesg[mlen-1] != '\n') + return -EINVAL; + mesg[mlen-1] = 0; + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + /* client */ + err = -EINVAL; + len = qword_get(&mesg, buf, PAGE_SIZE); + if (len <= 0) + goto out; + + err = -ENOENT; + dom = auth_domain_find(buf); + if (!dom) + goto out; + + /* path */ + err = -EINVAL; + if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0) + goto out1; + + err = kern_path(buf, 0, &exp.ex_path); + if (err) + goto out1; + + exp.ex_client = dom; + exp.cd = cd; + exp.ex_devid_map = NULL; + + /* expiry */ + err = -EINVAL; + exp.h.expiry_time = get_expiry(&mesg); + if (exp.h.expiry_time == 0) + goto out3; + + /* flags */ + err = get_int(&mesg, &an_int); + if (err == -ENOENT) { + err = 0; + set_bit(CACHE_NEGATIVE, &exp.h.flags); + } else { + if (err || an_int < 0) + goto out3; + exp.ex_flags= an_int; + + /* anon uid */ + err = get_int(&mesg, &an_int); + if (err) + goto out3; + exp.ex_anon_uid= make_kuid(current_user_ns(), an_int); + + /* anon gid */ + err = get_int(&mesg, &an_int); + if (err) + goto out3; + exp.ex_anon_gid= make_kgid(current_user_ns(), an_int); + + /* fsid */ + err = get_int(&mesg, &an_int); + if (err) + goto out3; + exp.ex_fsid = an_int; + + while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) { + if (strcmp(buf, "fsloc") == 0) + err = fsloc_parse(&mesg, buf, &exp.ex_fslocs); + else if (strcmp(buf, "uuid") == 0) + err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid); + else if (strcmp(buf, "secinfo") == 0) + err = secinfo_parse(&mesg, buf, &exp); + else + /* quietly ignore unknown words and anything + * following. Newer user-space can try to set + * new values, then see what the result was. + */ + break; + if (err) + goto out4; + } + + err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags, + exp.ex_uuid); + if (err) + goto out4; + /* + * No point caching this if it would immediately expire. + * Also, this protects exportfs's dummy export from the + * anon_uid/anon_gid checks: + */ + if (exp.h.expiry_time < seconds_since_boot()) + goto out4; + /* + * For some reason exportfs has been passing down an + * invalid (-1) uid & gid on the "dummy" export which it + * uses to test export support. To make sure exportfs + * sees errors from check_export we therefore need to + * delay these checks till after check_export: + */ + err = -EINVAL; + if (!uid_valid(exp.ex_anon_uid)) + goto out4; + if (!gid_valid(exp.ex_anon_gid)) + goto out4; + err = 0; + + nfsd4_setup_layout_type(&exp); + } + + expp = svc_export_lookup(&exp); + if (!expp) { + err = -ENOMEM; + goto out4; + } + expp = svc_export_update(&exp, expp); + if (expp) { + trace_nfsd_export_update(expp); + cache_flush(); + exp_put(expp); + } else + err = -ENOMEM; +out4: + nfsd4_fslocs_free(&exp.ex_fslocs); + kfree(exp.ex_uuid); +out3: + path_put(&exp.ex_path); +out1: + auth_domain_put(dom); +out: + kfree(buf); + return err; +} + +static void exp_flags(struct seq_file *m, int flag, int fsid, + kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs); +static void show_secinfo(struct seq_file *m, struct svc_export *exp); + +static int svc_export_show(struct seq_file *m, + struct cache_detail *cd, + struct cache_head *h) +{ + struct svc_export *exp ; + + if (h ==NULL) { + seq_puts(m, "#path domain(flags)\n"); + return 0; + } + exp = container_of(h, struct svc_export, h); + seq_path(m, &exp->ex_path, " \t\n\\"); + seq_putc(m, '\t'); + seq_escape(m, exp->ex_client->name, " \t\n\\"); + seq_putc(m, '('); + if (test_bit(CACHE_VALID, &h->flags) && + !test_bit(CACHE_NEGATIVE, &h->flags)) { + exp_flags(m, exp->ex_flags, exp->ex_fsid, + exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs); + if (exp->ex_uuid) { + int i; + seq_puts(m, ",uuid="); + for (i = 0; i < EX_UUID_LEN; i++) { + if ((i&3) == 0 && i) + seq_putc(m, ':'); + seq_printf(m, "%02x", exp->ex_uuid[i]); + } + } + show_secinfo(m, exp); + } + seq_puts(m, ")\n"); + return 0; +} +static int svc_export_match(struct cache_head *a, struct cache_head *b) +{ + struct svc_export *orig = container_of(a, struct svc_export, h); + struct svc_export *new = container_of(b, struct svc_export, h); + return orig->ex_client == new->ex_client && + path_equal(&orig->ex_path, &new->ex_path); +} + +static void svc_export_init(struct cache_head *cnew, struct cache_head *citem) +{ + struct svc_export *new = container_of(cnew, struct svc_export, h); + struct svc_export *item = container_of(citem, struct svc_export, h); + + kref_get(&item->ex_client->ref); + new->ex_client = item->ex_client; + new->ex_path = item->ex_path; + path_get(&item->ex_path); + new->ex_fslocs.locations = NULL; + new->ex_fslocs.locations_count = 0; + new->ex_fslocs.migrated = 0; + new->ex_layout_types = 0; + new->ex_uuid = NULL; + new->cd = item->cd; +} + +static void export_update(struct cache_head *cnew, struct cache_head *citem) +{ + struct svc_export *new = container_of(cnew, struct svc_export, h); + struct svc_export *item = container_of(citem, struct svc_export, h); + int i; + + new->ex_flags = item->ex_flags; + new->ex_anon_uid = item->ex_anon_uid; + new->ex_anon_gid = item->ex_anon_gid; + new->ex_fsid = item->ex_fsid; + new->ex_devid_map = item->ex_devid_map; + item->ex_devid_map = NULL; + new->ex_uuid = item->ex_uuid; + item->ex_uuid = NULL; + new->ex_fslocs.locations = item->ex_fslocs.locations; + item->ex_fslocs.locations = NULL; + new->ex_fslocs.locations_count = item->ex_fslocs.locations_count; + item->ex_fslocs.locations_count = 0; + new->ex_fslocs.migrated = item->ex_fslocs.migrated; + item->ex_fslocs.migrated = 0; + new->ex_layout_types = item->ex_layout_types; + new->ex_nflavors = item->ex_nflavors; + for (i = 0; i < MAX_SECINFO_LIST; i++) { + new->ex_flavors[i] = item->ex_flavors[i]; + } +} + +static struct cache_head *svc_export_alloc(void) +{ + struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL); + if (i) + return &i->h; + else + return NULL; +} + +static const struct cache_detail svc_export_cache_template = { + .owner = THIS_MODULE, + .hash_size = EXPORT_HASHMAX, + .name = "nfsd.export", + .cache_put = svc_export_put, + .cache_upcall = svc_export_upcall, + .cache_request = svc_export_request, + .cache_parse = svc_export_parse, + .cache_show = svc_export_show, + .match = svc_export_match, + .init = svc_export_init, + .update = export_update, + .alloc = svc_export_alloc, +}; + +static int +svc_export_hash(struct svc_export *exp) +{ + int hash; + + hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS); + hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS); + hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS); + return hash; +} + +static struct svc_export * +svc_export_lookup(struct svc_export *exp) +{ + struct cache_head *ch; + int hash = svc_export_hash(exp); + + ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash); + if (ch) + return container_of(ch, struct svc_export, h); + else + return NULL; +} + +static struct svc_export * +svc_export_update(struct svc_export *new, struct svc_export *old) +{ + struct cache_head *ch; + int hash = svc_export_hash(old); + + ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash); + if (ch) + return container_of(ch, struct svc_export, h); + else + return NULL; +} + + +static struct svc_expkey * +exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type, + u32 *fsidv, struct cache_req *reqp) +{ + struct svc_expkey key, *ek; + int err; + + if (!clp) + return ERR_PTR(-ENOENT); + + key.ek_client = clp; + key.ek_fsidtype = fsid_type; + memcpy(key.ek_fsid, fsidv, key_len(fsid_type)); + + ek = svc_expkey_lookup(cd, &key); + if (ek == NULL) + return ERR_PTR(-ENOMEM); + err = cache_check(cd, &ek->h, reqp); + if (err) { + trace_nfsd_exp_find_key(&key, err); + return ERR_PTR(err); + } + return ek; +} + +static struct svc_export * +exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp, + const struct path *path, struct cache_req *reqp) +{ + struct svc_export *exp, key; + int err; + + if (!clp) + return ERR_PTR(-ENOENT); + + key.ex_client = clp; + key.ex_path = *path; + key.cd = cd; + + exp = svc_export_lookup(&key); + if (exp == NULL) + return ERR_PTR(-ENOMEM); + err = cache_check(cd, &exp->h, reqp); + if (err) { + trace_nfsd_exp_get_by_name(&key, err); + return ERR_PTR(err); + } + return exp; +} + +/* + * Find the export entry for a given dentry. + */ +static struct svc_export * +exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path) +{ + struct dentry *saved = dget(path->dentry); + struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL); + + while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) { + struct dentry *parent = dget_parent(path->dentry); + dput(path->dentry); + path->dentry = parent; + exp = exp_get_by_name(cd, clp, path, NULL); + } + dput(path->dentry); + path->dentry = saved; + return exp; +} + + + +/* + * 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 net *net, struct auth_domain *clp, char *name, + struct knfsd_fh *f, int maxsize) +{ + struct svc_export *exp; + struct path path; + struct inode *inode; + struct svc_fh fh; + int err; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct cache_detail *cd = nn->svc_export_cache; + + err = -EPERM; + /* NB: we probably ought to check that it's NUL-terminated */ + if (kern_path(name, 0, &path)) { + printk("nfsd: exp_rootfh path not found %s", name); + return err; + } + inode = d_inode(path.dentry); + + dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n", + name, path.dentry, clp->name, + inode->i_sb->s_id, inode->i_ino); + exp = exp_parent(cd, clp, &path); + if (IS_ERR(exp)) { + err = PTR_ERR(exp); + goto out; + } + + /* + * fh must be initialized before calling fh_compose + */ + fh_init(&fh, maxsize); + if (fh_compose(&fh, exp, path.dentry, NULL)) + err = -EINVAL; + else + err = 0; + memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh)); + fh_put(&fh); + exp_put(exp); +out: + path_put(&path); + return err; +} + +static struct svc_export *exp_find(struct cache_detail *cd, + struct auth_domain *clp, int fsid_type, + u32 *fsidv, struct cache_req *reqp) +{ + struct svc_export *exp; + struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id); + struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp); + if (IS_ERR(ek)) + return ERR_CAST(ek); + + exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp); + cache_put(&ek->h, nn->svc_expkey_cache); + + if (IS_ERR(exp)) + return ERR_CAST(exp); + return exp; +} + +__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp) +{ + struct exp_flavor_info *f; + struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors; + + /* legacy gss-only clients are always OK: */ + if (exp->ex_client == rqstp->rq_gssclient) + return 0; + /* ip-address based client; check sec= export option: */ + for (f = exp->ex_flavors; f < end; f++) { + if (f->pseudoflavor == rqstp->rq_cred.cr_flavor) + return 0; + } + /* defaults in absence of sec= options: */ + if (exp->ex_nflavors == 0) { + if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL || + rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX) + return 0; + } + + /* If the compound op contains a spo_must_allowed op, + * it will be sent with integrity/protection which + * will have to be expressly allowed on mounts that + * don't support it + */ + + if (nfsd4_spo_must_allow(rqstp)) + return 0; + + return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec; +} + +/* + * Uses rq_client and rq_gssclient to find an export; uses rq_client (an + * auth_unix client) if it's available and has secinfo information; + * otherwise, will try to use rq_gssclient. + * + * Called from functions that handle requests; functions that do work on + * behalf of mountd are passed a single client name to use, and should + * use exp_get_by_name() or exp_find(). + */ +struct svc_export * +rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path) +{ + struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT); + struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); + struct cache_detail *cd = nn->svc_export_cache; + + if (rqstp->rq_client == NULL) + goto gss; + + /* First try the auth_unix client: */ + exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle); + if (PTR_ERR(exp) == -ENOENT) + goto gss; + if (IS_ERR(exp)) + return exp; + /* If it has secinfo, assume there are no gss/... clients */ + if (exp->ex_nflavors > 0) + return exp; +gss: + /* Otherwise, try falling back on gss client */ + if (rqstp->rq_gssclient == NULL) + return exp; + gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle); + if (PTR_ERR(gssexp) == -ENOENT) + return exp; + if (!IS_ERR(exp)) + exp_put(exp); + return gssexp; +} + +struct svc_export * +rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv) +{ + struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT); + struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); + struct cache_detail *cd = nn->svc_export_cache; + + if (rqstp->rq_client == NULL) + goto gss; + + /* First try the auth_unix client: */ + exp = exp_find(cd, rqstp->rq_client, fsid_type, + fsidv, &rqstp->rq_chandle); + if (PTR_ERR(exp) == -ENOENT) + goto gss; + if (IS_ERR(exp)) + return exp; + /* If it has secinfo, assume there are no gss/... clients */ + if (exp->ex_nflavors > 0) + return exp; +gss: + /* Otherwise, try falling back on gss client */ + if (rqstp->rq_gssclient == NULL) + return exp; + gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv, + &rqstp->rq_chandle); + if (PTR_ERR(gssexp) == -ENOENT) + return exp; + if (!IS_ERR(exp)) + exp_put(exp); + return gssexp; +} + +struct svc_export * +rqst_exp_parent(struct svc_rqst *rqstp, struct path *path) +{ + struct dentry *saved = dget(path->dentry); + struct svc_export *exp = rqst_exp_get_by_name(rqstp, path); + + while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) { + struct dentry *parent = dget_parent(path->dentry); + dput(path->dentry); + path->dentry = parent; + exp = rqst_exp_get_by_name(rqstp, path); + } + dput(path->dentry); + path->dentry = saved; + return exp; +} + +struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp) +{ + u32 fsidv[2]; + + mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL); + + return rqst_exp_find(rqstp, FSID_NUM, fsidv); +} + +/* + * Called when we need the filehandle for the root of the pseudofs, + * for a given NFSv4 client. The root is defined to be the + * export point with fsid==0 + */ +__be32 +exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp) +{ + struct svc_export *exp; + __be32 rv; + + exp = rqst_find_fsidzero_export(rqstp); + if (IS_ERR(exp)) + return nfserrno(PTR_ERR(exp)); + rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL); + exp_put(exp); + return rv; +} + +static 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_NOREADDIRPLUS, {"nordirplus", ""}}, + { NFSEXP_NOHIDE, {"nohide", ""}}, + { NFSEXP_CROSSMOUNT, {"crossmnt", ""}}, + { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}}, + { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}}, + { NFSEXP_V4ROOT, {"v4root", ""}}, + { NFSEXP_PNFS, {"pnfs", ""}}, + { NFSEXP_SECURITY_LABEL, {"security_label", ""}}, + { 0, {"", ""}} +}; + +static void show_expflags(struct seq_file *m, int flags, int mask) +{ + struct flags *flg; + int state, first = 0; + + for (flg = expflags; flg->flag; flg++) { + if (flg->flag & ~mask) + continue; + state = (flg->flag & flags) ? 0 : 1; + if (*flg->name[state]) + seq_printf(m, "%s%s", first++?",":"", flg->name[state]); + } +} + +static void show_secinfo_flags(struct seq_file *m, int flags) +{ + seq_printf(m, ","); + show_expflags(m, flags, NFSEXP_SECINFO_FLAGS); +} + +static bool secinfo_flags_equal(int f, int g) +{ + f &= NFSEXP_SECINFO_FLAGS; + g &= NFSEXP_SECINFO_FLAGS; + return f == g; +} + +static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end) +{ + int flags; + + flags = (*fp)->flags; + seq_printf(m, ",sec=%d", (*fp)->pseudoflavor); + (*fp)++; + while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) { + seq_printf(m, ":%d", (*fp)->pseudoflavor); + (*fp)++; + } + return flags; +} + +static void show_secinfo(struct seq_file *m, struct svc_export *exp) +{ + struct exp_flavor_info *f; + struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors; + int flags; + + if (exp->ex_nflavors == 0) + return; + f = exp->ex_flavors; + flags = show_secinfo_run(m, &f, end); + if (!secinfo_flags_equal(flags, exp->ex_flags)) + show_secinfo_flags(m, flags); + while (f != end) { + flags = show_secinfo_run(m, &f, end); + show_secinfo_flags(m, flags); + } +} + +static void exp_flags(struct seq_file *m, int flag, int fsid, + kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc) +{ + struct user_namespace *userns = m->file->f_cred->user_ns; + + show_expflags(m, flag, NFSEXP_ALLFLAGS); + if (flag & NFSEXP_FSID) + seq_printf(m, ",fsid=%d", fsid); + if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) && + !uid_eq(anonu, make_kuid(userns, 0x10000-2))) + seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu)); + if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) && + !gid_eq(anong, make_kgid(userns, 0x10000-2))) + seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong)); + if (fsloc && fsloc->locations_count > 0) { + char *loctype = (fsloc->migrated) ? "refer" : "replicas"; + int i; + + seq_printf(m, ",%s=", loctype); + seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\"); + seq_putc(m, '@'); + seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\"); + for (i = 1; i < fsloc->locations_count; i++) { + seq_putc(m, ';'); + seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\"); + seq_putc(m, '@'); + seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\"); + } + } +} + +static int e_show(struct seq_file *m, void *p) +{ + struct cache_head *cp = p; + struct svc_export *exp = container_of(cp, struct svc_export, h); + struct cache_detail *cd = m->private; + + if (p == SEQ_START_TOKEN) { + seq_puts(m, "# Version 1.1\n"); + seq_puts(m, "# Path Client(Flags) # IPs\n"); + return 0; + } + + exp_get(exp); + if (cache_check(cd, &exp->h, NULL)) + return 0; + exp_put(exp); + return svc_export_show(m, cd, cp); +} + +const struct seq_operations nfs_exports_op = { + .start = cache_seq_start_rcu, + .next = cache_seq_next_rcu, + .stop = cache_seq_stop_rcu, + .show = e_show, +}; + +/* + * Initialize the exports module. + */ +int +nfsd_export_init(struct net *net) +{ + int rv; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum); + + nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net); + if (IS_ERR(nn->svc_export_cache)) + return PTR_ERR(nn->svc_export_cache); + rv = cache_register_net(nn->svc_export_cache, net); + if (rv) + goto destroy_export_cache; + + nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net); + if (IS_ERR(nn->svc_expkey_cache)) { + rv = PTR_ERR(nn->svc_expkey_cache); + goto unregister_export_cache; + } + rv = cache_register_net(nn->svc_expkey_cache, net); + if (rv) + goto destroy_expkey_cache; + return 0; + +destroy_expkey_cache: + cache_destroy_net(nn->svc_expkey_cache, net); +unregister_export_cache: + cache_unregister_net(nn->svc_export_cache, net); +destroy_export_cache: + cache_destroy_net(nn->svc_export_cache, net); + return rv; +} + +/* + * Flush exports table - called when last nfsd thread is killed + */ +void +nfsd_export_flush(struct net *net) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + cache_purge(nn->svc_expkey_cache); + cache_purge(nn->svc_export_cache); +} + +/* + * Shutdown the exports module. + */ +void +nfsd_export_shutdown(struct net *net) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum); + + cache_unregister_net(nn->svc_expkey_cache, net); + cache_unregister_net(nn->svc_export_cache, net); + cache_destroy_net(nn->svc_expkey_cache, net); + cache_destroy_net(nn->svc_export_cache, net); + svcauth_unix_purge(net); + + dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum); +} |