// SPDX-License-Identifier: BSD-3-Clause /* * linux/net/sunrpc/auth_gss/auth_gss.c * * RPCSEC_GSS client authentication. * * Copyright (c) 2000 The Regents of the University of Michigan. * All rights reserved. * * Dug Song * Andy Adamson */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "auth_gss_internal.h" #include "../netns.h" #include static const struct rpc_authops authgss_ops; static const struct rpc_credops gss_credops; static const struct rpc_credops gss_nullops; #define GSS_RETRY_EXPIRED 5 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED; #define GSS_KEY_EXPIRE_TIMEO 240 static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO; #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) # define RPCDBG_FACILITY RPCDBG_AUTH #endif #define GSS_CRED_SLACK (RPC_MAX_AUTH_SIZE * 2) /* length of a krb5 verifier (48), plus data added before arguments when * using integrity (two 4-byte integers): */ #define GSS_VERF_SLACK 100 static DEFINE_HASHTABLE(gss_auth_hash_table, 4); static DEFINE_SPINLOCK(gss_auth_hash_lock); struct gss_pipe { struct rpc_pipe_dir_object pdo; struct rpc_pipe *pipe; struct rpc_clnt *clnt; const char *name; struct kref kref; }; struct gss_auth { struct kref kref; struct hlist_node hash; struct rpc_auth rpc_auth; struct gss_api_mech *mech; enum rpc_gss_svc service; struct rpc_clnt *client; struct net *net; /* * There are two upcall pipes; dentry[1], named "gssd", is used * for the new text-based upcall; dentry[0] is named after the * mechanism (for example, "krb5") and exists for * backwards-compatibility with older gssd's. */ struct gss_pipe *gss_pipe[2]; const char *target_name; }; /* pipe_version >= 0 if and only if someone has a pipe open. */ static DEFINE_SPINLOCK(pipe_version_lock); static struct rpc_wait_queue pipe_version_rpc_waitqueue; static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue); static void gss_put_auth(struct gss_auth *gss_auth); static void gss_free_ctx(struct gss_cl_ctx *); static const struct rpc_pipe_ops gss_upcall_ops_v0; static const struct rpc_pipe_ops gss_upcall_ops_v1; static inline struct gss_cl_ctx * gss_get_ctx(struct gss_cl_ctx *ctx) { refcount_inc(&ctx->count); return ctx; } static inline void gss_put_ctx(struct gss_cl_ctx *ctx) { if (refcount_dec_and_test(&ctx->count)) gss_free_ctx(ctx); } /* gss_cred_set_ctx: * called by gss_upcall_callback and gss_create_upcall in order * to set the gss context. The actual exchange of an old context * and a new one is protected by the pipe->lock. */ static void gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx) { struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)) return; gss_get_ctx(ctx); rcu_assign_pointer(gss_cred->gc_ctx, ctx); set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); smp_mb__before_atomic(); clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags); } static struct gss_cl_ctx * gss_cred_get_ctx(struct rpc_cred *cred) { struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_cl_ctx *ctx = NULL; rcu_read_lock(); ctx = rcu_dereference(gss_cred->gc_ctx); if (ctx) gss_get_ctx(ctx); rcu_read_unlock(); return ctx; } static struct gss_cl_ctx * gss_alloc_context(void) { struct gss_cl_ctx *ctx; ctx = kzalloc(sizeof(*ctx), GFP_NOFS); if (ctx != NULL) { ctx->gc_proc = RPC_GSS_PROC_DATA; ctx->gc_seq = 1; /* NetApp 6.4R1 doesn't accept seq. no. 0 */ spin_lock_init(&ctx->gc_seq_lock); refcount_set(&ctx->count,1); } return ctx; } #define GSSD_MIN_TIMEOUT (60 * 60) static const void * gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm) { const void *q; unsigned int seclen; unsigned int timeout; unsigned long now = jiffies; u32 window_size; int ret; /* First unsigned int gives the remaining lifetime in seconds of the * credential - e.g. the remaining TGT lifetime for Kerberos or * the -t value passed to GSSD. */ p = simple_get_bytes(p, end, &timeout, sizeof(timeout)); if (IS_ERR(p)) goto err; if (timeout == 0) timeout = GSSD_MIN_TIMEOUT; ctx->gc_expiry = now + ((unsigned long)timeout * HZ); /* Sequence number window. Determines the maximum number of * simultaneous requests */ p = simple_get_bytes(p, end, &window_size, sizeof(window_size)); if (IS_ERR(p)) goto err; ctx->gc_win = window_size; /* gssd signals an error by passing ctx->gc_win = 0: */ if (ctx->gc_win == 0) { /* * in which case, p points to an error code. Anything other * than -EKEYEXPIRED gets converted to -EACCES. */ p = simple_get_bytes(p, end, &ret, sizeof(ret)); if (!IS_ERR(p)) p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) : ERR_PTR(-EACCES); goto err; } /* copy the opaque wire context */ p = simple_get_netobj(p, end, &ctx->gc_wire_ctx); if (IS_ERR(p)) goto err; /* import the opaque security context */ p = simple_get_bytes(p, end, &seclen, sizeof(seclen)); if (IS_ERR(p)) goto err; q = (const void *)((const char *)p + seclen); if (unlikely(q > end || q < p)) { p = ERR_PTR(-EFAULT); goto err; } ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS); if (ret < 0) { trace_rpcgss_import_ctx(ret); p = ERR_PTR(ret); goto err; } /* is there any trailing data? */ if (q == end) { p = q; goto done; } /* pull in acceptor name (if there is one) */ p = simple_get_netobj(q, end, &ctx->gc_acceptor); if (IS_ERR(p)) goto err; done: trace_rpcgss_context(ctx->gc_expiry, now, timeout, ctx->gc_acceptor.len, ctx->gc_acceptor.data); err: return p; } /* XXX: Need some documentation about why UPCALL_BUF_LEN is so small. * Is user space expecting no more than UPCALL_BUF_LEN bytes? * Note that there are now _two_ NI_MAXHOST sized data items * being passed in this string. */ #define UPCALL_BUF_LEN 256 struct gss_upcall_msg { refcount_t count; kuid_t uid; const char *service_name; struct rpc_pipe_msg msg; struct list_head list; struct gss_auth *auth; struct rpc_pipe *pipe; struct rpc_wait_queue rpc_waitqueue; wait_queue_head_t waitqueue; struct gss_cl_ctx *ctx; char databuf[UPCALL_BUF_LEN]; }; static int get_pipe_version(struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); int ret; spin_lock(&pipe_version_lock); if (sn->pipe_version >= 0) { atomic_inc(&sn->pipe_users); ret = sn->pipe_version; } else ret = -EAGAIN; spin_unlock(&pipe_version_lock); return ret; } static void put_pipe_version(struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) { sn->pipe_version = -1; spin_unlock(&pipe_version_lock); } } static void gss_release_msg(struct gss_upcall_msg *gss_msg) { struct net *net = gss_msg->auth->net; if (!refcount_dec_and_test(&gss_msg->count)) return; put_pipe_version(net); BUG_ON(!list_empty(&gss_msg->list)); if (gss_msg->ctx != NULL) gss_put_ctx(gss_msg->ctx); rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue); gss_put_auth(gss_msg->auth); kfree_const(gss_msg->service_name); kfree(gss_msg); } static struct gss_upcall_msg * __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth) { struct gss_upcall_msg *pos; list_for_each_entry(pos, &pipe->in_downcall, list) { if (!uid_eq(pos->uid, uid)) continue; if (auth && pos->auth->service != auth->service) continue; refcount_inc(&pos->count); return pos; } return NULL; } /* Try to add an upcall to the pipefs queue. * If an upcall owned by our uid already exists, then we return a reference * to that upcall instead of adding the new upcall. */ static inline struct gss_upcall_msg * gss_add_msg(struct gss_upcall_msg *gss_msg) { struct rpc_pipe *pipe = gss_msg->pipe; struct gss_upcall_msg *old; spin_lock(&pipe->lock); old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth); if (old == NULL) { refcount_inc(&gss_msg->count); list_add(&gss_msg->list, &pipe->in_downcall); } else gss_msg = old; spin_unlock(&pipe->lock); return gss_msg; } static void __gss_unhash_msg(struct gss_upcall_msg *gss_msg) { list_del_init(&gss_msg->list); rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); wake_up_all(&gss_msg->waitqueue); refcount_dec(&gss_msg->count); } static void gss_unhash_msg(struct gss_upcall_msg *gss_msg) { struct rpc_pipe *pipe = gss_msg->pipe; if (list_empty(&gss_msg->list)) return; spin_lock(&pipe->lock); if (!list_empty(&gss_msg->list)) __gss_unhash_msg(gss_msg); spin_unlock(&pipe->lock); } static void gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg) { switch (gss_msg->msg.errno) { case 0: if (gss_msg->ctx == NULL) break; clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags); gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx); break; case -EKEYEXPIRED: set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags); } gss_cred->gc_upcall_timestamp = jiffies; gss_cred->gc_upcall = NULL; rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); } static void gss_upcall_callback(struct rpc_task *task) { struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred, struct gss_cred, gc_base); struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall; struct rpc_pipe *pipe = gss_msg->pipe; spin_lock(&pipe->lock); gss_handle_downcall_result(gss_cred, gss_msg); spin_unlock(&pipe->lock); task->tk_status = gss_msg->msg.errno; gss_release_msg(gss_msg); } static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg, const struct cred *cred) { struct user_namespace *userns = cred->user_ns; uid_t uid = from_kuid_munged(userns, gss_msg->uid); memcpy(gss_msg->databuf, &uid, sizeof(uid)); gss_msg->msg.data = gss_msg->databuf; gss_msg->msg.len = sizeof(uid); BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf)); } static ssize_t gss_v0_upcall(struct file *file, struct rpc_pipe_msg *msg, char __user *buf, size_t buflen) { struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg); if (msg->copied == 0) gss_encode_v0_msg(gss_msg, file->f_cred); return rpc_pipe_generic_upcall(file, msg, buf, buflen); } static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg, const char *service_name, const char *target_name, const struct cred *cred) { struct user_namespace *userns = cred->user_ns; struct gss_api_mech *mech = gss_msg->auth->mech; char *p = gss_msg->databuf; size_t buflen = sizeof(gss_msg->databuf); int len; len = scnprintf(p, buflen, "mech=%s uid=%d", mech->gm_name, from_kuid_munged(userns, gss_msg->uid)); buflen -= len; p += len; gss_msg->msg.len = len; /* * target= is a full service principal that names the remote * identity that we are authenticating to. */ if (target_name) { len = scnprintf(p, buflen, " target=%s", target_name); buflen -= len; p += len; gss_msg->msg.len += len; } /* * gssd uses service= and srchost= to select a matching key from * the system's keytab to use as the source principal. * * service= is the service name part of the source principal, * or "*" (meaning choose any). * * srchost= is the hostname part of the source principal. When * not provided, gssd uses the local hostname. */ if (service_name) { char *c = strchr(service_name, '@'); if (!c) len = scnprintf(p, buflen, " service=%s", service_name); else len = scnprintf(p, buflen, " service=%.*s srchost=%s", (int)(c - service_name), service_name, c + 1); buflen -= len; p += len; gss_msg->msg.len += len; } if (mech->gm_upcall_enctypes) { len = scnprintf(p, buflen, " enctypes=%s", mech->gm_upcall_enctypes); buflen -= len; p += len; gss_msg->msg.len += len; } trace_rpcgss_upcall_msg(gss_msg->databuf); len = scnprintf(p, buflen, "\n"); if (len == 0) goto out_overflow; gss_msg->msg.len += len; gss_msg->msg.data = gss_msg->databuf; return 0; out_overflow: WARN_ON_ONCE(1); return -ENOMEM; } static ssize_t gss_v1_upcall(struct file *file, struct rpc_pipe_msg *msg, char __user *buf, size_t buflen) { struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg); int err; if (msg->copied == 0) { err = gss_encode_v1_msg(gss_msg, gss_msg->service_name, gss_msg->auth->target_name, file->f_cred); if (err) return err; } return rpc_pipe_generic_upcall(file, msg, buf, buflen); } static struct gss_upcall_msg * gss_alloc_msg(struct gss_auth *gss_auth, kuid_t uid, const char *service_name) { struct gss_upcall_msg *gss_msg; int vers; int err = -ENOMEM; gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS); if (gss_msg == NULL) goto err; vers = get_pipe_version(gss_auth->net); err = vers; if (err < 0) goto err_free_msg; gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe; INIT_LIST_HEAD(&gss_msg->list); rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq"); init_waitqueue_head(&gss_msg->waitqueue); refcount_set(&gss_msg->count, 1); gss_msg->uid = uid; gss_msg->auth = gss_auth; kref_get(&gss_auth->kref); if (service_name) { gss_msg->service_name = kstrdup_const(service_name, GFP_NOFS); if (!gss_msg->service_name) { err = -ENOMEM; goto err_put_pipe_version; } } return gss_msg; err_put_pipe_version: put_pipe_version(gss_auth->net); err_free_msg: kfree(gss_msg); err: return ERR_PTR(err); } static struct gss_upcall_msg * gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred) { struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_upcall_msg *gss_new, *gss_msg; kuid_t uid = cred->cr_cred->fsuid; gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal); if (IS_ERR(gss_new)) return gss_new; gss_msg = gss_add_msg(gss_new); if (gss_msg == gss_new) { int res; refcount_inc(&gss_msg->count); res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg); if (res) { gss_unhash_msg(gss_new); refcount_dec(&gss_msg->count); gss_release_msg(gss_new); gss_msg = ERR_PTR(res); } } else gss_release_msg(gss_new); return gss_msg; } static void warn_gssd(void) { dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n"); } static inline int gss_refresh_upcall(struct rpc_task *task) { struct rpc_cred *cred = task->tk_rqstp->rq_cred; struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth); struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_upcall_msg *gss_msg; struct rpc_pipe *pipe; int err = 0; gss_msg = gss_setup_upcall(gss_auth, cred); if (PTR_ERR(gss_msg) == -EAGAIN) { /* XXX: warning on the first, under the assumption we * shouldn't normally hit this case on a refresh. */ warn_gssd(); rpc_sleep_on_timeout(&pipe_version_rpc_waitqueue, task, NULL, jiffies + (15 * HZ)); err = -EAGAIN; goto out; } if (IS_ERR(gss_msg)) { err = PTR_ERR(gss_msg); goto out; } pipe = gss_msg->pipe; spin_lock(&pipe->lock); if (gss_cred->gc_upcall != NULL) rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL); else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) { gss_cred->gc_upcall = gss_msg; /* gss_upcall_callback will release the reference to gss_upcall_msg */ refcount_inc(&gss_msg->count); rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback); } else { gss_handle_downcall_result(gss_cred, gss_msg); err = gss_msg->msg.errno; } spin_unlock(&pipe->lock); gss_release_msg(gss_msg); out: trace_rpcgss_upcall_result(from_kuid(&init_user_ns, cred->cr_cred->fsuid), err); return err; } static inline int gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred) { struct net *net = gss_auth->net; struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); struct rpc_pipe *pipe; struct rpc_cred *cred = &gss_cred->gc_base; struct gss_upcall_msg *gss_msg; DEFINE_WAIT(wait); int err; retry: err = 0; /* if gssd is down, just skip upcalling altogether */ if (!gssd_running(net)) { warn_gssd(); err = -EACCES; goto out; } gss_msg = gss_setup_upcall(gss_auth, cred); if (PTR_ERR(gss_msg) == -EAGAIN) { err = wait_event_interruptible_timeout(pipe_version_waitqueue, sn->pipe_version >= 0, 15 * HZ); if (sn->pipe_version < 0) { warn_gssd(); err = -EACCES; } if (err < 0) goto out; goto retry; } if (IS_ERR(gss_msg)) { err = PTR_ERR(gss_msg); goto out; } pipe = gss_msg->pipe; for (;;) { prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE); spin_lock(&pipe->lock); if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) { break; } spin_unlock(&pipe->lock); if (fatal_signal_pending(current)) { err = -ERESTARTSYS; goto out_intr; } schedule(); } if (gss_msg->ctx) gss_cred_set_ctx(cred, gss_msg->ctx); else err = gss_msg->msg.errno; spin_unlock(&pipe->lock); out_intr: finish_wait(&gss_msg->waitqueue, &wait); gss_release_msg(gss_msg); out: trace_rpcgss_upcall_result(from_kuid(&init_user_ns, cred->cr_cred->fsuid), err); return err; } #define MSG_BUF_MAXSIZE 1024 static ssize_t gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) { const void *p, *end; void *buf; struct gss_upcall_msg *gss_msg; struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe; struct gss_cl_ctx *ctx; uid_t id; kuid_t uid; ssize_t err = -EFBIG; if (mlen > MSG_BUF_MAXSIZE) goto out; err = -ENOMEM; buf = kmalloc(mlen, GFP_NOFS); if (!buf) goto out; err = -EFAULT; if (copy_from_user(buf, src, mlen)) goto err; end = (const void *)((char *)buf + mlen); p = simple_get_bytes(buf, end, &id, sizeof(id)); if (IS_ERR(p)) { err = PTR_ERR(p); goto err; } uid = make_kuid(current_user_ns(), id); if (!uid_valid(uid)) { err = -EINVAL; goto err; } err = -ENOMEM; ctx = gss_alloc_context(); if (ctx == NULL) goto err; err = -ENOENT; /* Find a matching upcall */ spin_lock(&pipe->lock); gss_msg = __gss_find_upcall(pipe, uid, NULL); if (gss_msg == NULL) { spin_unlock(&pipe->lock); goto err_put_ctx; } list_del_init(&gss_msg->list); spin_unlock(&pipe->lock); p = gss_fill_context(p, end, ctx, gss_msg->auth->mech); if (IS_ERR(p)) { err = PTR_ERR(p); switch (err) { case -EACCES: case -EKEYEXPIRED: gss_msg->msg.errno = err; err = mlen; break; case -EFAULT: case -ENOMEM: case -EINVAL: case -ENOSYS: gss_msg->msg.errno = -EAGAIN; break; default: printk(KERN_CRIT "%s: bad return from " "gss_fill_context: %zd\n", __func__, err); gss_msg->msg.errno = -EIO; } goto err_release_msg; } gss_msg->ctx = gss_get_ctx(ctx); err = mlen; err_release_msg: spin_lock(&pipe->lock); __gss_unhash_msg(gss_msg); spin_unlock(&pipe->lock); gss_release_msg(gss_msg); err_put_ctx: gss_put_ctx(ctx); err: kfree(buf); out: return err; } static int gss_pipe_open(struct inode *inode, int new_version) { struct net *net = inode->i_sb->s_fs_info; struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); int ret = 0; spin_lock(&pipe_version_lock); if (sn->pipe_version < 0) { /* First open of any gss pipe determines the version: */ sn->pipe_version = new_version; rpc_wake_up(&pipe_version_rpc_waitqueue); wake_up(&pipe_version_waitqueue); } else if (sn->pipe_version != new_version) { /* Trying to open a pipe of a different version */ ret = -EBUSY; goto out; } atomic_inc(&sn->pipe_users); out: spin_unlock(&pipe_version_lock); return ret; } static int gss_pipe_open_v0(struct inode *inode) { return gss_pipe_open(inode, 0); } static int gss_pipe_open_v1(struct inode *inode) { return gss_pipe_open(inode, 1); } static void gss_pipe_release(struct inode *inode) { struct net *net = inode->i_sb->s_fs_info; struct rpc_pipe *pipe = RPC_I(inode)->pipe; struct gss_upcall_msg *gss_msg; restart: spin_lock(&pipe->lock); list_for_each_entry(gss_msg, &pipe->in_downcall, list) { if (!list_empty(&gss_msg->msg.list)) continue; gss_msg->msg.errno = -EPIPE; refcount_inc(&gss_msg->count); __gss_unhash_msg(gss_msg); spin_unlock(&pipe->lock); gss_release_msg(gss_msg); goto restart; } spin_unlock(&pipe->lock); put_pipe_version(net); } static void gss_pipe_destroy_msg(struct rpc_pipe_msg *msg) { struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg); if (msg->errno < 0) { refcount_inc(&gss_msg->count); gss_unhash_msg(gss_msg); if (msg->errno == -ETIMEDOUT) warn_gssd(); gss_release_msg(gss_msg); } gss_release_msg(gss_msg); } static void gss_pipe_dentry_destroy(struct dentry *dir, struct rpc_pipe_dir_object *pdo) { struct gss_pipe *gss_pipe = pdo->pdo_data; struct rpc_pipe *pipe = gss_pipe->pipe; if (pipe->dentry != NULL) { rpc_unlink(pipe->dentry); pipe->dentry = NULL; } } static int gss_pipe_dentry_create(struct dentry *dir, struct rpc_pipe_dir_object *pdo) { struct gss_pipe *p = pdo->pdo_data; struct dentry *dentry; dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe); if (IS_ERR(dentry)) return PTR_ERR(dentry); p->pipe->dentry = dentry; return 0; } static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = { .create = gss_pipe_dentry_create, .destroy = gss_pipe_dentry_destroy, }; static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt, const char *name, const struct rpc_pipe_ops *upcall_ops) { struct gss_pipe *p; int err = -ENOMEM; p = kmalloc(sizeof(*p), GFP_KERNEL); if (p == NULL) goto err; p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN); if (IS_ERR(p->pipe)) { err = PTR_ERR(p->pipe); goto err_free_gss_pipe; } p->name = name; p->clnt = clnt; kref_init(&p->kref); rpc_init_pipe_dir_object(&p->pdo, &gss_pipe_dir_object_ops, p); return p; err_free_gss_pipe: kfree(p); err: return ERR_PTR(err); } struct gss_alloc_pdo { struct rpc_clnt *clnt; const char *name; const struct rpc_pipe_ops *upcall_ops; }; static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data) { struct gss_pipe *gss_pipe; struct gss_alloc_pdo *args = data; if (pdo->pdo_ops != &gss_pipe_dir_object_ops) return 0; gss_pipe = container_of(pdo, struct gss_pipe, pdo); if (strcmp(gss_pipe->name, args->name) != 0) return 0; if (!kref_get_unless_zero(&gss_pipe->kref)) return 0; return 1; } static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data) { struct gss_pipe *gss_pipe; struct gss_alloc_pdo *args = data; gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops); if (!IS_ERR(gss_pipe)) return &gss_pipe->pdo; return NULL; } static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt, const char *name, const struct rpc_pipe_ops *upcall_ops) { struct net *net = rpc_net_ns(clnt); struct rpc_pipe_dir_object *pdo; struct gss_alloc_pdo args = { .clnt = clnt, .name = name, .upcall_ops = upcall_ops, }; pdo = rpc_find_or_alloc_pipe_dir_object(net, &clnt->cl_pipedir_objects, gss_pipe_match_pdo, gss_pipe_alloc_pdo, &args); if (pdo != NULL) return container_of(pdo, struct gss_pipe, pdo); return ERR_PTR(-ENOMEM); } static void __gss_pipe_free(struct gss_pipe *p) { struct rpc_clnt *clnt = p->clnt; struct net *net = rpc_net_ns(clnt); rpc_remove_pipe_dir_object(net, &clnt->cl_pipedir_objects, &p->pdo); rpc_destroy_pipe_data(p->pipe); kfree(p); } static void __gss_pipe_release(struct kref *kref) { struct gss_pipe *p = container_of(kref, struct gss_pipe, kref); __gss_pipe_free(p); } static void gss_pipe_free(struct gss_pipe *p) { if (p != NULL) kref_put(&p->kref, __gss_pipe_release); } /* * NOTE: we have the opportunity to use different * parameters based on the input flavor (which must be a pseudoflavor) */ static struct gss_auth * gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt) { rpc_authflavor_t flavor = args->pseudoflavor; struct gss_auth *gss_auth; struct gss_pipe *gss_pipe; struct rpc_auth * auth; int err = -ENOMEM; /* XXX? */ if (!try_module_get(THIS_MODULE)) return ERR_PTR(err); if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL))) goto out_dec; INIT_HLIST_NODE(&gss_auth->hash); gss_auth->target_name = NULL; if (args->target_name) { gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL); if (gss_auth->target_name == NULL) goto err_free; } gss_auth->client = clnt; gss_auth->net = get_net(rpc_net_ns(clnt)); err = -EINVAL; gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor); if (!gss_auth->mech) goto err_put_net; gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor); if (gss_auth->service == 0) goto err_put_mech; if (!gssd_running(gss_auth->net)) goto err_put_mech; auth = &gss_auth->rpc_auth; auth->au_cslack = GSS_CRED_SLACK >> 2; auth->au_rslack = GSS_KRB5_MAX_SLACK_NEEDED >> 2; auth->au_verfsize = GSS_VERF_SLACK >> 2; auth->au_ralign = GSS_VERF_SLACK >> 2; auth->au_flags = 0; auth->au_ops = &authgss_ops; auth->au_flavor = flavor; if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor)) auth->au_flags |= RPCAUTH_AUTH_DATATOUCH; refcount_set(&auth->au_count, 1); kref_init(&gss_auth->kref); err = rpcauth_init_credcache(auth); if (err) goto err_put_mech; /* * Note: if we created the old pipe first, then someone who * examined the directory at the right moment might conclude * that we supported only the old pipe. So we instead create * the new pipe first. */ gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1); if (IS_ERR(gss_pipe)) { err = PTR_ERR(gss_pipe); goto err_destroy_credcache; } gss_auth->gss_pipe[1] = gss_pipe; gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name, &gss_upcall_ops_v0); if (IS_ERR(gss_pipe)) { err = PTR_ERR(gss_pipe); goto err_destroy_pipe_1; } gss_auth->gss_pipe[0] = gss_pipe; return gss_auth; err_destroy_pipe_1: gss_pipe_free(gss_auth->gss_pipe[1]); err_destroy_credcache: rpcauth_destroy_credcache(auth); err_put_mech: gss_mech_put(gss_auth->mech); err_put_net: put_net(gss_auth->net); err_free: kfree(gss_auth->target_name); kfree(gss_auth); out_dec: module_put(THIS_MODULE); trace_rpcgss_createauth(flavor, err); return ERR_PTR(err); } static void gss_free(struct gss_auth *gss_auth) { gss_pipe_free(gss_auth->gss_pipe[0]); gss_pipe_free(gss_auth->gss_pipe[1]); gss_mech_put(gss_auth->mech); put_net(gss_auth->net); kfree(gss_auth->target_name); kfree(gss_auth); module_put(THIS_MODULE); } static void gss_free_callback(struct kref *kref) { struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref); gss_free(gss_auth); } static void gss_put_auth(struct gss_auth *gss_auth) { kref_put(&gss_auth->kref, gss_free_callback); } static void gss_destroy(struct rpc_auth *auth) { struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); if (hash_hashed(&gss_auth->hash)) { spin_lock(&gss_auth_hash_lock); hash_del(&gss_auth->hash); spin_unlock(&gss_auth_hash_lock); } gss_pipe_free(gss_auth->gss_pipe[0]); gss_auth->gss_pipe[0] = NULL; gss_pipe_free(gss_auth->gss_pipe[1]); gss_auth->gss_pipe[1] = NULL; rpcauth_destroy_credcache(auth); gss_put_auth(gss_auth); } /* * Auths may be shared between rpc clients that were cloned from a * common client with the same xprt, if they also share the flavor and * target_name. * * The auth is looked up from the oldest parent sharing the same * cl_xprt, and the auth itself references only that common parent * (which is guaranteed to last as long as any of its descendants). */ static struct gss_auth * gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt, struct gss_auth *new) { struct gss_auth *gss_auth; unsigned long hashval = (unsigned long)clnt; spin_lock(&gss_auth_hash_lock); hash_for_each_possible(gss_auth_hash_table, gss_auth, hash, hashval) { if (gss_auth->client != clnt) continue; if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor) continue; if (gss_auth->target_name != args->target_name) { if (gss_auth->target_name == NULL) continue; if (args->target_name == NULL) continue; if (strcmp(gss_auth->target_name, args->target_name)) continue; } if (!refcount_inc_not_zero(&gss_auth->rpc_auth.au_count)) continue; goto out; } if (new) hash_add(gss_auth_hash_table, &new->hash, hashval); gss_auth = new; out: spin_unlock(&gss_auth_hash_lock); return gss_auth; } static struct gss_auth * gss_create_hashed(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt) { struct gss_auth *gss_auth; struct gss_auth *new; gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL); if (gss_auth != NULL) goto out; new = gss_create_new(args, clnt); if (IS_ERR(new)) return new; gss_auth = gss_auth_find_or_add_hashed(args, clnt, new); if (gss_auth != new) gss_destroy(&new->rpc_auth); out: return gss_auth; } static struct rpc_auth * gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt) { struct gss_auth *gss_auth; struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch); while (clnt != clnt->cl_parent) { struct rpc_clnt *parent = clnt->cl_parent; /* Find the original parent for this transport */ if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps) break; clnt = parent; } gss_auth = gss_create_hashed(args, clnt); if (IS_ERR(gss_auth)) return ERR_CAST(gss_auth); return &gss_auth->rpc_auth; } static struct gss_cred * gss_dup_cred(struct gss_auth *gss_auth, struct gss_cred *gss_cred) { struct gss_cred *new; /* Make a copy of the cred so that we can reference count it */ new = kzalloc(sizeof(*gss_cred), GFP_NOFS); if (new) { struct auth_cred acred = { .cred = gss_cred->gc_base.cr_cred, }; struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1); rpcauth_init_cred(&new->gc_base, &acred, &gss_auth->rpc_auth, &gss_nullops); new->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE; new->gc_service = gss_cred->gc_service; new->gc_principal = gss_cred->gc_principal; kref_get(&gss_auth->kref); rcu_assign_pointer(new->gc_ctx, ctx); gss_get_ctx(ctx); } return new; } /* * gss_send_destroy_context will cause the RPCSEC_GSS to send a NULL RPC call * to the server with the GSS control procedure field set to * RPC_GSS_PROC_DESTROY. This should normally cause the server to release * all RPCSEC_GSS state associated with that context. */ static void gss_send_destroy_context(struct rpc_cred *cred) { struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth); struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1); struct gss_cred *new; struct rpc_task *task; new = gss_dup_cred(gss_auth, gss_cred); if (new) { ctx->gc_proc = RPC_GSS_PROC_DESTROY; task = rpc_call_null(gss_auth->client, &new->gc_base, RPC_TASK_ASYNC|RPC_TASK_SOFT); if (!IS_ERR(task)) rpc_put_task(task); put_rpccred(&new->gc_base); } } /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure * to create a new cred or context, so they check that things have been * allocated before freeing them. */ static void gss_do_free_ctx(struct gss_cl_ctx *ctx) { gss_delete_sec_context(&ctx->gc_gss_ctx); kfree(ctx->gc_wire_ctx.data); kfree(ctx->gc_acceptor.data); kfree(ctx); } static void gss_free_ctx_callback(struct rcu_head *head) { struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu); gss_do_free_ctx(ctx); } static void gss_free_ctx(struct gss_cl_ctx *ctx) { call_rcu(&ctx->gc_rcu, gss_free_ctx_callback); } static void gss_free_cred(struct gss_cred *gss_cred) { kfree(gss_cred); } static void gss_free_cred_callback(struct rcu_head *head) { struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu); gss_free_cred(gss_cred); } static void gss_destroy_nullcred(struct rpc_cred *cred) { struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth); struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1); RCU_INIT_POINTER(gss_cred->gc_ctx, NULL); put_cred(cred->cr_cred); call_rcu(&cred->cr_rcu, gss_free_cred_callback); if (ctx) gss_put_ctx(ctx); gss_put_auth(gss_auth); } static void gss_destroy_cred(struct rpc_cred *cred) { if (test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) gss_send_destroy_context(cred); gss_destroy_nullcred(cred); } static int gss_hash_cred(struct auth_cred *acred, unsigned int hashbits) { return hash_64(from_kuid(&init_user_ns, acred->cred->fsuid), hashbits); } /* * Lookup RPCSEC_GSS cred for the current process */ static struct rpc_cred * gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) { return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS); } static struct rpc_cred * gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp) { struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); struct gss_cred *cred = NULL; int err = -ENOMEM; if (!(cred = kzalloc(sizeof(*cred), gfp))) goto out_err; rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops); /* * Note: in order to force a call to call_refresh(), we deliberately * fail to flag the credential as RPCAUTH_CRED_UPTODATE. */ cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW; cred->gc_service = gss_auth->service; cred->gc_principal = acred->principal; kref_get(&gss_auth->kref); return &cred->gc_base; out_err: return ERR_PTR(err); } static int gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred) { struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base); int err; do { err = gss_create_upcall(gss_auth, gss_cred); } while (err == -EAGAIN); return err; } static char * gss_stringify_acceptor(struct rpc_cred *cred) { char *string = NULL; struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_cl_ctx *ctx; unsigned int len; struct xdr_netobj *acceptor; rcu_read_lock(); ctx = rcu_dereference(gss_cred->gc_ctx); if (!ctx) goto out; len = ctx->gc_acceptor.len; rcu_read_unlock(); /* no point if there's no string */ if (!len) return NULL; realloc: string = kmalloc(len + 1, GFP_KERNEL); if (!string) return NULL; rcu_read_lock(); ctx = rcu_dereference(gss_cred->gc_ctx); /* did the ctx disappear or was it replaced by one with no acceptor? */ if (!ctx || !ctx->gc_acceptor.len) { kfree(string); string = NULL; goto out; } acceptor = &ctx->gc_acceptor; /* * Did we find a new acceptor that's longer than the original? Allocate * a longer buffer and try again. */ if (len < acceptor->len) { len = acceptor->len; rcu_read_unlock(); kfree(string); goto realloc; } memcpy(string, acceptor->data, acceptor->len); string[acceptor->len] = '\0'; out: rcu_read_unlock(); return string; } /* * Returns -EACCES if GSS context is NULL or will expire within the * timeout (miliseconds) */ static int gss_key_timeout(struct rpc_cred *rc) { struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base); struct gss_cl_ctx *ctx; unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ); int ret = 0; rcu_read_lock(); ctx = rcu_dereference(gss_cred->gc_ctx); if (!ctx || time_after(timeout, ctx->gc_expiry)) ret = -EACCES; rcu_read_unlock(); return ret; } static int gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags) { struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base); struct gss_cl_ctx *ctx; int ret; if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags)) goto out; /* Don't match with creds that have expired. */ rcu_read_lock(); ctx = rcu_dereference(gss_cred->gc_ctx); if (!ctx || time_after(jiffies, ctx->gc_expiry)) { rcu_read_unlock(); return 0; } rcu_read_unlock(); if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags)) return 0; out: if (acred->principal != NULL) { if (gss_cred->gc_principal == NULL) return 0; ret = strcmp(acred->principal, gss_cred->gc_principal) == 0; } else { if (gss_cred->gc_principal != NULL) return 0; ret = uid_eq(rc->cr_cred->fsuid, acred->cred->fsuid); } return ret; } /* * Marshal credentials. * * The expensive part is computing the verifier. We can't cache a * pre-computed version of the verifier because the seqno, which * is different every time, is included in the MIC. */ static int gss_marshal(struct rpc_task *task, struct xdr_stream *xdr) { struct rpc_rqst *req = task->tk_rqstp; struct rpc_cred *cred = req->rq_cred; struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); __be32 *p, *cred_len; u32 maj_stat = 0; struct xdr_netobj mic; struct kvec iov; struct xdr_buf verf_buf; int status; /* Credential */ p = xdr_reserve_space(xdr, 7 * sizeof(*p) + ctx->gc_wire_ctx.len); if (!p) goto marshal_failed; *p++ = rpc_auth_gss; cred_len = p++; spin_lock(&ctx->gc_seq_lock); req->rq_seqno = (ctx->gc_seq < MAXSEQ) ? ctx->gc_seq++ : MAXSEQ; spin_unlock(&ctx->gc_seq_lock); if (req->rq_seqno == MAXSEQ) goto expired; trace_rpcgss_seqno(task); *p++ = cpu_to_be32(RPC_GSS_VERSION); *p++ = cpu_to_be32(ctx->gc_proc); *p++ = cpu_to_be32(req->rq_seqno); *p++ = cpu_to_be32(gss_cred->gc_service); p = xdr_encode_netobj(p, &ctx->gc_wire_ctx); *cred_len = cpu_to_be32((p - (cred_len + 1)) << 2); /* Verifier */ /* We compute the checksum for the verifier over the xdr-encoded bytes * starting with the xid and ending at the end of the credential: */ iov.iov_base = req->rq_snd_buf.head[0].iov_base; iov.iov_len = (u8 *)p - (u8 *)iov.iov_base; xdr_buf_from_iov(&iov, &verf_buf); p = xdr_reserve_space(xdr, sizeof(*p)); if (!p) goto marshal_failed; *p++ = rpc_auth_gss; mic.data = (u8 *)(p + 1); maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic); if (maj_stat == GSS_S_CONTEXT_EXPIRED) goto expired; else if (maj_stat != 0) goto bad_mic; if (xdr_stream_encode_opaque_inline(xdr, (void **)&p, mic.len) < 0) goto marshal_failed; status = 0; out: gss_put_ctx(ctx); return status; expired: clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); status = -EKEYEXPIRED; goto out; marshal_failed: status = -EMSGSIZE; goto out; bad_mic: trace_rpcgss_get_mic(task, maj_stat); status = -EIO; goto out; } static int gss_renew_cred(struct rpc_task *task) { struct rpc_cred *oldcred = task->tk_rqstp->rq_cred; struct gss_cred *gss_cred = container_of(oldcred, struct gss_cred, gc_base); struct rpc_auth *auth = oldcred->cr_auth; struct auth_cred acred = { .cred = oldcred->cr_cred, .principal = gss_cred->gc_principal, }; struct rpc_cred *new; new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW); if (IS_ERR(new)) return PTR_ERR(new); task->tk_rqstp->rq_cred = new; put_rpccred(oldcred); return 0; } static int gss_cred_is_negative_entry(struct rpc_cred *cred) { if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) { unsigned long now = jiffies; unsigned long begin, expire; struct gss_cred *gss_cred; gss_cred = container_of(cred, struct gss_cred, gc_base); begin = gss_cred->gc_upcall_timestamp; expire = begin + gss_expired_cred_retry_delay * HZ; if (time_in_range_open(now, begin, expire)) return 1; } return 0; } /* * Refresh credentials. XXX - finish */ static int gss_refresh(struct rpc_task *task) { struct rpc_cred *cred = task->tk_rqstp->rq_cred; int ret = 0; if (gss_cred_is_negative_entry(cred)) return -EKEYEXPIRED; if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) && !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) { ret = gss_renew_cred(task); if (ret < 0) goto out; cred = task->tk_rqstp->rq_cred; } if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)) ret = gss_refresh_upcall(task); out: return ret; } /* Dummy refresh routine: used only when destroying the context */ static int gss_refresh_null(struct rpc_task *task) { return 0; } static int gss_validate(struct rpc_task *task, struct xdr_stream *xdr) { struct rpc_cred *cred = task->tk_rqstp->rq_cred; struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); __be32 *p, *seq = NULL; struct kvec iov; struct xdr_buf verf_buf; struct xdr_netobj mic; u32 len, maj_stat; int status; p = xdr_inline_decode(xdr, 2 * sizeof(*p)); if (!p) goto validate_failed; if (*p++ != rpc_auth_gss) goto validate_failed; len = be32_to_cpup(p); if (len > RPC_MAX_AUTH_SIZE) goto validate_failed; p = xdr_inline_decode(xdr, len); if (!p) goto validate_failed; seq = kmalloc(4, GFP_NOFS); if (!seq) goto validate_failed; *seq = cpu_to_be32(task->tk_rqstp->rq_seqno); iov.iov_base = seq; iov.iov_len = 4; xdr_buf_from_iov(&iov, &verf_buf); mic.data = (u8 *)p; mic.len = len; maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic); if (maj_stat == GSS_S_CONTEXT_EXPIRED) clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); if (maj_stat) goto bad_mic; /* We leave it to unwrap to calculate au_rslack. For now we just * calculate the length of the verifier: */ cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2; status = 0; out: gss_put_ctx(ctx); kfree(seq); return status; validate_failed: status = -EIO; goto out; bad_mic: trace_rpcgss_verify_mic(task, maj_stat); status = -EACCES; goto out; } static int gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, struct rpc_task *task, struct xdr_stream *xdr) { struct rpc_rqst *rqstp = task->tk_rqstp; struct xdr_buf integ_buf, *snd_buf = &rqstp->rq_snd_buf; struct xdr_netobj mic; __be32 *p, *integ_len; u32 offset, maj_stat; p = xdr_reserve_space(xdr, 2 * sizeof(*p)); if (!p) goto wrap_failed; integ_len = p++; *p = cpu_to_be32(rqstp->rq_seqno); if (rpcauth_wrap_req_encode(task, xdr)) goto wrap_failed; offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; if (xdr_buf_subsegment(snd_buf, &integ_buf, offset, snd_buf->len - offset)) goto wrap_failed; *integ_len = cpu_to_be32(integ_buf.len); p = xdr_reserve_space(xdr, 0); if (!p) goto wrap_failed; mic.data = (u8 *)(p + 1); maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic); if (maj_stat == GSS_S_CONTEXT_EXPIRED) clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); else if (maj_stat) goto bad_mic; /* Check that the trailing MIC fit in the buffer, after the fact */ if (xdr_stream_encode_opaque_inline(xdr, (void **)&p, mic.len) < 0) goto wrap_failed; return 0; wrap_failed: return -EMSGSIZE; bad_mic: trace_rpcgss_get_mic(task, maj_stat); return -EIO; } static void priv_release_snd_buf(struct rpc_rqst *rqstp) { int i; for (i=0; i < rqstp->rq_enc_pages_num; i++) __free_page(rqstp->rq_enc_pages[i]); kfree(rqstp->rq_enc_pages); rqstp->rq_release_snd_buf = NULL; } static int alloc_enc_pages(struct rpc_rqst *rqstp) { struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; int first, last, i; if (rqstp->rq_release_snd_buf) rqstp->rq_release_snd_buf(rqstp); if (snd_buf->page_len == 0) { rqstp->rq_enc_pages_num = 0; return 0; } first = snd_buf->page_base >> PAGE_SHIFT; last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT; rqstp->rq_enc_pages_num = last - first + 1 + 1; rqstp->rq_enc_pages = kmalloc_array(rqstp->rq_enc_pages_num, sizeof(struct page *), GFP_NOFS); if (!rqstp->rq_enc_pages) goto out; for (i=0; i < rqstp->rq_enc_pages_num; i++) { rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS); if (rqstp->rq_enc_pages[i] == NULL) goto out_free; } rqstp->rq_release_snd_buf = priv_release_snd_buf; return 0; out_free: rqstp->rq_enc_pages_num = i; priv_release_snd_buf(rqstp); out: return -EAGAIN; } static int gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, struct rpc_task *task, struct xdr_stream *xdr) { struct rpc_rqst *rqstp = task->tk_rqstp; struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; u32 pad, offset, maj_stat; int status; __be32 *p, *opaque_len; struct page **inpages; int first; struct kvec *iov; status = -EIO; p = xdr_reserve_space(xdr, 2 * sizeof(*p)); if (!p) goto wrap_failed; opaque_len = p++; *p = cpu_to_be32(rqstp->rq_seqno); if (rpcauth_wrap_req_encode(task, xdr)) goto wrap_failed; status = alloc_enc_pages(rqstp); if (unlikely(status)) goto wrap_failed; first = snd_buf->page_base >> PAGE_SHIFT; inpages = snd_buf->pages + first; snd_buf->pages = rqstp->rq_enc_pages; snd_buf->page_base -= first << PAGE_SHIFT; /* * Move the tail into its own page, in case gss_wrap needs * more space in the head when wrapping. * * Still... Why can't gss_wrap just slide the tail down? */ if (snd_buf->page_len || snd_buf->tail[0].iov_len) { char *tmp; tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]); memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len); snd_buf->tail[0].iov_base = tmp; } offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages); /* slack space should prevent this ever happening: */ if (unlikely(snd_buf->len > snd_buf->buflen)) goto wrap_failed; /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was * done anyway, so it's safe to put the request on the wire: */ if (maj_stat == GSS_S_CONTEXT_EXPIRED) clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); else if (maj_stat) goto bad_wrap; *opaque_len = cpu_to_be32(snd_buf->len - offset); /* guess whether the pad goes into the head or the tail: */ if (snd_buf->page_len || snd_buf->tail[0].iov_len) iov = snd_buf->tail; else iov = snd_buf->head; p = iov->iov_base + iov->iov_len; pad = 3 - ((snd_buf->len - offset - 1) & 3); memset(p, 0, pad); iov->iov_len += pad; snd_buf->len += pad; return 0; wrap_failed: return status; bad_wrap: trace_rpcgss_wrap(task, maj_stat); return -EIO; } static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr) { struct rpc_cred *cred = task->tk_rqstp->rq_cred; struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); int status; status = -EIO; if (ctx->gc_proc != RPC_GSS_PROC_DATA) { /* The spec seems a little ambiguous here, but I think that not * wrapping context destruction requests makes the most sense. */ status = rpcauth_wrap_req_encode(task, xdr); goto out; } switch (gss_cred->gc_service) { case RPC_GSS_SVC_NONE: status = rpcauth_wrap_req_encode(task, xdr); break; case RPC_GSS_SVC_INTEGRITY: status = gss_wrap_req_integ(cred, ctx, task, xdr); break; case RPC_GSS_SVC_PRIVACY: status = gss_wrap_req_priv(cred, ctx, task, xdr); break; default: status = -EIO; } out: gss_put_ctx(ctx); return status; } static int gss_unwrap_resp_auth(struct rpc_cred *cred) { struct rpc_auth *auth = cred->cr_auth; auth->au_rslack = auth->au_verfsize; auth->au_ralign = auth->au_verfsize; return 0; } /* * RFC 2203, Section 5.3.2.2 * * struct rpc_gss_integ_data { * opaque databody_integ<>; * opaque checksum<>; * }; * * struct rpc_gss_data_t { * unsigned int seq_num; * proc_req_arg_t arg; * }; */ static int gss_unwrap_resp_integ(struct rpc_task *task, struct rpc_cred *cred, struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp, struct xdr_stream *xdr) { struct xdr_buf gss_data, *rcv_buf = &rqstp->rq_rcv_buf; struct rpc_auth *auth = cred->cr_auth; u32 len, offset, seqno, maj_stat; struct xdr_netobj mic; int ret; ret = -EIO; mic.data = NULL; /* opaque databody_integ<>; */ if (xdr_stream_decode_u32(xdr, &len)) goto unwrap_failed; if (len & 3) goto unwrap_failed; offset = rcv_buf->len - xdr_stream_remaining(xdr); if (xdr_stream_decode_u32(xdr, &seqno)) goto unwrap_failed; if (seqno != rqstp->rq_seqno) goto bad_seqno; if (xdr_buf_subsegment(rcv_buf, &gss_data, offset, len)) goto unwrap_failed; /* * The xdr_stream now points to the beginning of the * upper layer payload, to be passed below to * rpcauth_unwrap_resp_decode(). The checksum, which * follows the upper layer payload in @rcv_buf, is * located and parsed without updating the xdr_stream. */ /* opaque checksum<>; */ offset += len; if (xdr_decode_word(rcv_buf, offset, &len)) goto unwrap_failed; offset += sizeof(__be32); if (offset + len > rcv_buf->len) goto unwrap_failed; mic.len = len; mic.data = kmalloc(len, GFP_NOFS); if (!mic.data) goto unwrap_failed; if (read_bytes_from_xdr_buf(rcv_buf, offset, mic.data, mic.len)) goto unwrap_failed; maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &gss_data, &mic); if (maj_stat == GSS_S_CONTEXT_EXPIRED) clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); if (maj_stat != GSS_S_COMPLETE) goto bad_mic; auth->au_rslack = auth->au_verfsize + 2 + 1 + XDR_QUADLEN(mic.len); auth->au_ralign = auth->au_verfsize + 2; ret = 0; out: kfree(mic.data); return ret; unwrap_failed: trace_rpcgss_unwrap_failed(task); goto out; bad_seqno: trace_rpcgss_bad_seqno(task, rqstp->rq_seqno, seqno); goto out; bad_mic: trace_rpcgss_verify_mic(task, maj_stat); goto out; } static int gss_unwrap_resp_priv(struct rpc_task *task, struct rpc_cred *cred, struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp, struct xdr_stream *xdr) { struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; struct kvec *head = rqstp->rq_rcv_buf.head; struct rpc_auth *auth = cred->cr_auth; u32 offset, opaque_len, maj_stat; __be32 *p; p = xdr_inline_decode(xdr, 2 * sizeof(*p)); if (unlikely(!p)) goto unwrap_failed; opaque_len = be32_to_cpup(p++); offset = (u8 *)(p) - (u8 *)head->iov_base; if (offset + opaque_len > rcv_buf->len) goto unwrap_failed; maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, offset + opaque_len, rcv_buf); if (maj_stat == GSS_S_CONTEXT_EXPIRED) clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); if (maj_stat != GSS_S_COMPLETE) goto bad_unwrap; /* gss_unwrap decrypted the sequence number */ if (be32_to_cpup(p++) != rqstp->rq_seqno) goto bad_seqno; /* gss_unwrap redacts the opaque blob from the head iovec. * rcv_buf has changed, thus the stream needs to be reset. */ xdr_init_decode(xdr, rcv_buf, p, rqstp); auth->au_rslack = auth->au_verfsize + 2 + ctx->gc_gss_ctx->slack; auth->au_ralign = auth->au_verfsize + 2 + ctx->gc_gss_ctx->align; return 0; unwrap_failed: trace_rpcgss_unwrap_failed(task); return -EIO; bad_seqno: trace_rpcgss_bad_seqno(task, rqstp->rq_seqno, be32_to_cpup(--p)); return -EIO; bad_unwrap: trace_rpcgss_unwrap(task, maj_stat); return -EIO; } static bool gss_seq_is_newer(u32 new, u32 old) { return (s32)(new - old) > 0; } static bool gss_xmit_need_reencode(struct rpc_task *task) { struct rpc_rqst *req = task->tk_rqstp; struct rpc_cred *cred = req->rq_cred; struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); u32 win, seq_xmit = 0; bool ret = true; if (!ctx) goto out; if (gss_seq_is_newer(req->rq_seqno, READ_ONCE(ctx->gc_seq))) goto out_ctx; seq_xmit = READ_ONCE(ctx->gc_seq_xmit); while (gss_seq_is_newer(req->rq_seqno, seq_xmit)) { u32 tmp = seq_xmit; seq_xmit = cmpxchg(&ctx->gc_seq_xmit, tmp, req->rq_seqno); if (seq_xmit == tmp) { ret = false; goto out_ctx; } } win = ctx->gc_win; if (win > 0) ret = !gss_seq_is_newer(req->rq_seqno, seq_xmit - win); out_ctx: gss_put_ctx(ctx); out: trace_rpcgss_need_reencode(task, seq_xmit, ret); return ret; } static int gss_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr) { struct rpc_rqst *rqstp = task->tk_rqstp; struct rpc_cred *cred = rqstp->rq_cred; struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base); struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); int status = -EIO; if (ctx->gc_proc != RPC_GSS_PROC_DATA) goto out_decode; switch (gss_cred->gc_service) { case RPC_GSS_SVC_NONE: status = gss_unwrap_resp_auth(cred); break; case RPC_GSS_SVC_INTEGRITY: status = gss_unwrap_resp_integ(task, cred, ctx, rqstp, xdr); break; case RPC_GSS_SVC_PRIVACY: status = gss_unwrap_resp_priv(task, cred, ctx, rqstp, xdr); break; } if (status) goto out; out_decode: status = rpcauth_unwrap_resp_decode(task, xdr); out: gss_put_ctx(ctx); return status; } static const struct rpc_authops authgss_ops = { .owner = THIS_MODULE, .au_flavor = RPC_AUTH_GSS, .au_name = "RPCSEC_GSS", .create = gss_create, .destroy = gss_destroy, .hash_cred = gss_hash_cred, .lookup_cred = gss_lookup_cred, .crcreate = gss_create_cred, .list_pseudoflavors = gss_mech_list_pseudoflavors, .info2flavor = gss_mech_info2flavor, .flavor2info = gss_mech_flavor2info, }; static const struct rpc_credops gss_credops = { .cr_name = "AUTH_GSS", .crdestroy = gss_destroy_cred, .cr_init = gss_cred_init, .crmatch = gss_match, .crmarshal = gss_marshal, .crrefresh = gss_refresh, .crvalidate = gss_validate, .crwrap_req = gss_wrap_req, .crunwrap_resp = gss_unwrap_resp, .crkey_timeout = gss_key_timeout, .crstringify_acceptor = gss_stringify_acceptor, .crneed_reencode = gss_xmit_need_reencode, }; static const struct rpc_credops gss_nullops = { .cr_name = "AUTH_GSS", .crdestroy = gss_destroy_nullcred, .crmatch = gss_match, .crmarshal = gss_marshal, .crrefresh = gss_refresh_null, .crvalidate = gss_validate, .crwrap_req = gss_wrap_req, .crunwrap_resp = gss_unwrap_resp, .crstringify_acceptor = gss_stringify_acceptor, }; static const struct rpc_pipe_ops gss_upcall_ops_v0 = { .upcall = gss_v0_upcall, .downcall = gss_pipe_downcall, .destroy_msg = gss_pipe_destroy_msg, .open_pipe = gss_pipe_open_v0, .release_pipe = gss_pipe_release, }; static const struct rpc_pipe_ops gss_upcall_ops_v1 = { .upcall = gss_v1_upcall, .downcall = gss_pipe_downcall, .destroy_msg = gss_pipe_destroy_msg, .open_pipe = gss_pipe_open_v1, .release_pipe = gss_pipe_release, }; static __net_init int rpcsec_gss_init_net(struct net *net) { return gss_svc_init_net(net); } static __net_exit void rpcsec_gss_exit_net(struct net *net) { gss_svc_shutdown_net(net); } static struct pernet_operations rpcsec_gss_net_ops = { .init = rpcsec_gss_init_net, .exit = rpcsec_gss_exit_net, }; /* * Initialize RPCSEC_GSS module */ static int __init init_rpcsec_gss(void) { int err = 0; err = rpcauth_register(&authgss_ops); if (err) goto out; err = gss_svc_init(); if (err) goto out_unregister; err = register_pernet_subsys(&rpcsec_gss_net_ops); if (err) goto out_svc_exit; rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version"); return 0; out_svc_exit: gss_svc_shutdown(); out_unregister: rpcauth_unregister(&authgss_ops); out: return err; } static void __exit exit_rpcsec_gss(void) { unregister_pernet_subsys(&rpcsec_gss_net_ops); gss_svc_shutdown(); rpcauth_unregister(&authgss_ops); rcu_barrier(); /* Wait for completion of call_rcu()'s */ } MODULE_ALIAS("rpc-auth-6"); MODULE_LICENSE("GPL"); module_param_named(expired_cred_retry_delay, gss_expired_cred_retry_delay, uint, 0644); MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until " "the RPC engine retries an expired credential"); module_param_named(key_expire_timeo, gss_key_expire_timeo, uint, 0644); MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a " "credential keys lifetime where the NFS layer cleans up " "prior to key expiration"); module_init(init_rpcsec_gss) module_exit(exit_rpcsec_gss)