diff options
Diffstat (limited to 'net/sunrpc/auth_gss/auth_gss.c')
| -rw-r--r-- | net/sunrpc/auth_gss/auth_gss.c | 1372 |
1 files changed, 1372 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c new file mode 100644 index 0000000..853a414 --- /dev/null +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -0,0 +1,1372 @@ +/* + * 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 <dugsong@monkey.org> + * Andy Adamson <andros@umich.edu> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/pagemap.h> +#include <linux/sunrpc/clnt.h> +#include <linux/sunrpc/auth.h> +#include <linux/sunrpc/auth_gss.h> +#include <linux/sunrpc/svcauth_gss.h> +#include <linux/sunrpc/gss_err.h> +#include <linux/workqueue.h> +#include <linux/sunrpc/rpc_pipe_fs.h> +#include <linux/sunrpc/gss_api.h> +#include <asm/uaccess.h> + +static const struct rpc_authops authgss_ops; + +static const struct rpc_credops gss_credops; +static const struct rpc_credops gss_nullops; + +#ifdef RPC_DEBUG +# define RPCDBG_FACILITY RPCDBG_AUTH +#endif + +#define GSS_CRED_SLACK 1024 +/* length of a krb5 verifier (48), plus data added before arguments when + * using integrity (two 4-byte integers): */ +#define GSS_VERF_SLACK 100 + +struct gss_auth { + struct kref kref; + struct rpc_auth rpc_auth; + struct gss_api_mech *mech; + enum rpc_gss_svc service; + struct rpc_clnt *client; + struct dentry *dentry; +}; + +static void gss_free_ctx(struct gss_cl_ctx *); +static struct rpc_pipe_ops gss_upcall_ops; + +static inline struct gss_cl_ctx * +gss_get_ctx(struct gss_cl_ctx *ctx) +{ + atomic_inc(&ctx->count); + return ctx; +} + +static inline void +gss_put_ctx(struct gss_cl_ctx *ctx) +{ + if (atomic_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 inode->i_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_clear_bit(); + clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags); +} + +static const void * +simple_get_bytes(const void *p, const void *end, void *res, size_t len) +{ + const void *q = (const void *)((const char *)p + len); + if (unlikely(q > end || q < p)) + return ERR_PTR(-EFAULT); + memcpy(res, p, len); + return q; +} + +static inline const void * +simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest) +{ + const void *q; + unsigned int len; + + p = simple_get_bytes(p, end, &len, sizeof(len)); + if (IS_ERR(p)) + return p; + q = (const void *)((const char *)p + len); + if (unlikely(q > end || q < p)) + return ERR_PTR(-EFAULT); + dest->data = kmemdup(p, len, GFP_NOFS); + if (unlikely(dest->data == NULL)) + return ERR_PTR(-ENOMEM); + dest->len = len; + return q; +} + +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(); + if (gss_cred->gc_ctx) + ctx = gss_get_ctx(gss_cred->gc_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); + atomic_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; + u32 window_size; + int ret; + + /* First unsigned int gives the lifetime (in seconds) of the cred */ + 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 = jiffies + (unsigned long)timeout * HZ * 3 / 4; + /* 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 which we ignore */ + p = 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); + if (ret < 0) { + p = ERR_PTR(ret); + goto err; + } + return q; +err: + dprintk("RPC: gss_fill_context returning %ld\n", -PTR_ERR(p)); + return p; +} + + +struct gss_upcall_msg { + atomic_t count; + uid_t uid; + struct rpc_pipe_msg msg; + struct list_head list; + struct gss_auth *auth; + struct rpc_wait_queue rpc_waitqueue; + wait_queue_head_t waitqueue; + struct gss_cl_ctx *ctx; +}; + +static void +gss_release_msg(struct gss_upcall_msg *gss_msg) +{ + if (!atomic_dec_and_test(&gss_msg->count)) + return; + 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); + kfree(gss_msg); +} + +static struct gss_upcall_msg * +__gss_find_upcall(struct rpc_inode *rpci, uid_t uid) +{ + struct gss_upcall_msg *pos; + list_for_each_entry(pos, &rpci->in_downcall, list) { + if (pos->uid != uid) + continue; + atomic_inc(&pos->count); + dprintk("RPC: gss_find_upcall found msg %p\n", pos); + return pos; + } + dprintk("RPC: gss_find_upcall found nothing\n"); + 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_auth *gss_auth, struct gss_upcall_msg *gss_msg) +{ + struct inode *inode = gss_auth->dentry->d_inode; + struct rpc_inode *rpci = RPC_I(inode); + struct gss_upcall_msg *old; + + spin_lock(&inode->i_lock); + old = __gss_find_upcall(rpci, gss_msg->uid); + if (old == NULL) { + atomic_inc(&gss_msg->count); + list_add(&gss_msg->list, &rpci->in_downcall); + } else + gss_msg = old; + spin_unlock(&inode->i_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); + atomic_dec(&gss_msg->count); +} + +static void +gss_unhash_msg(struct gss_upcall_msg *gss_msg) +{ + struct gss_auth *gss_auth = gss_msg->auth; + struct inode *inode = gss_auth->dentry->d_inode; + + if (list_empty(&gss_msg->list)) + return; + spin_lock(&inode->i_lock); + if (!list_empty(&gss_msg->list)) + __gss_unhash_msg(gss_msg); + spin_unlock(&inode->i_lock); +} + +static void +gss_upcall_callback(struct rpc_task *task) +{ + struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred, + struct gss_cred, gc_base); + struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall; + struct inode *inode = gss_msg->auth->dentry->d_inode; + + spin_lock(&inode->i_lock); + if (gss_msg->ctx) + gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx); + else + task->tk_status = gss_msg->msg.errno; + gss_cred->gc_upcall = NULL; + rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); + spin_unlock(&inode->i_lock); + gss_release_msg(gss_msg); +} + +static inline struct gss_upcall_msg * +gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid) +{ + struct gss_upcall_msg *gss_msg; + + gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS); + if (gss_msg != NULL) { + INIT_LIST_HEAD(&gss_msg->list); + rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq"); + init_waitqueue_head(&gss_msg->waitqueue); + atomic_set(&gss_msg->count, 1); + gss_msg->msg.data = &gss_msg->uid; + gss_msg->msg.len = sizeof(gss_msg->uid); + gss_msg->uid = uid; + gss_msg->auth = gss_auth; + } + return gss_msg; +} + +static struct gss_upcall_msg * +gss_setup_upcall(struct rpc_clnt *clnt, 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; + uid_t uid = cred->cr_uid; + + /* Special case: rpc.gssd assumes that uid == 0 implies machine creds */ + if (gss_cred->gc_machine_cred != 0) + uid = 0; + + gss_new = gss_alloc_msg(gss_auth, uid); + if (gss_new == NULL) + return ERR_PTR(-ENOMEM); + gss_msg = gss_add_msg(gss_auth, gss_new); + if (gss_msg == gss_new) { + int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg); + if (res) { + gss_unhash_msg(gss_new); + gss_msg = ERR_PTR(res); + } + } else + gss_release_msg(gss_new); + return gss_msg; +} + +static inline int +gss_refresh_upcall(struct rpc_task *task) +{ + struct rpc_cred *cred = task->tk_msg.rpc_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 inode *inode = gss_auth->dentry->d_inode; + int err = 0; + + dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid, + cred->cr_uid); + gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred); + if (IS_ERR(gss_msg)) { + err = PTR_ERR(gss_msg); + goto out; + } + spin_lock(&inode->i_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_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx); + gss_cred->gc_upcall = NULL; + rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno); + } else if (gss_msg->msg.errno >= 0) { + task->tk_timeout = 0; + gss_cred->gc_upcall = gss_msg; + /* gss_upcall_callback will release the reference to gss_upcall_msg */ + atomic_inc(&gss_msg->count); + rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback); + } else + err = gss_msg->msg.errno; + spin_unlock(&inode->i_lock); + gss_release_msg(gss_msg); +out: + dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n", + task->tk_pid, cred->cr_uid, err); + return err; +} + +static inline int +gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred) +{ + struct inode *inode = gss_auth->dentry->d_inode; + struct rpc_cred *cred = &gss_cred->gc_base; + struct gss_upcall_msg *gss_msg; + DEFINE_WAIT(wait); + int err = 0; + + dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid); + gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred); + if (IS_ERR(gss_msg)) { + err = PTR_ERR(gss_msg); + goto out; + } + for (;;) { + prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE); + spin_lock(&inode->i_lock); + if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) { + break; + } + spin_unlock(&inode->i_lock); + if (signalled()) { + 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(&inode->i_lock); +out_intr: + finish_wait(&gss_msg->waitqueue, &wait); + gss_release_msg(gss_msg); +out: + dprintk("RPC: gss_create_upcall for uid %u result %d\n", + cred->cr_uid, err); + return err; +} + +static ssize_t +gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg, + char __user *dst, size_t buflen) +{ + char *data = (char *)msg->data + msg->copied; + size_t mlen = min(msg->len, buflen); + unsigned long left; + + left = copy_to_user(dst, data, mlen); + if (left == mlen) { + msg->errno = -EFAULT; + return -EFAULT; + } + + mlen -= left; + msg->copied += mlen; + msg->errno = 0; + return mlen; +} + +#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 inode *inode = filp->f_path.dentry->d_inode; + struct gss_cl_ctx *ctx; + uid_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, &uid, sizeof(uid)); + if (IS_ERR(p)) { + err = PTR_ERR(p); + goto err; + } + + err = -ENOMEM; + ctx = gss_alloc_context(); + if (ctx == NULL) + goto err; + + err = -ENOENT; + /* Find a matching upcall */ + spin_lock(&inode->i_lock); + gss_msg = __gss_find_upcall(RPC_I(inode), uid); + if (gss_msg == NULL) { + spin_unlock(&inode->i_lock); + goto err_put_ctx; + } + list_del_init(&gss_msg->list); + spin_unlock(&inode->i_lock); + + p = gss_fill_context(p, end, ctx, gss_msg->auth->mech); + if (IS_ERR(p)) { + err = PTR_ERR(p); + gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES; + goto err_release_msg; + } + gss_msg->ctx = gss_get_ctx(ctx); + err = mlen; + +err_release_msg: + spin_lock(&inode->i_lock); + __gss_unhash_msg(gss_msg); + spin_unlock(&inode->i_lock); + gss_release_msg(gss_msg); +err_put_ctx: + gss_put_ctx(ctx); +err: + kfree(buf); +out: + dprintk("RPC: gss_pipe_downcall returning %Zd\n", err); + return err; +} + +static void +gss_pipe_release(struct inode *inode) +{ + struct rpc_inode *rpci = RPC_I(inode); + struct gss_upcall_msg *gss_msg; + + spin_lock(&inode->i_lock); + while (!list_empty(&rpci->in_downcall)) { + + gss_msg = list_entry(rpci->in_downcall.next, + struct gss_upcall_msg, list); + gss_msg->msg.errno = -EPIPE; + atomic_inc(&gss_msg->count); + __gss_unhash_msg(gss_msg); + spin_unlock(&inode->i_lock); + gss_release_msg(gss_msg); + spin_lock(&inode->i_lock); + } + spin_unlock(&inode->i_lock); +} + +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); + static unsigned long ratelimit; + + if (msg->errno < 0) { + dprintk("RPC: gss_pipe_destroy_msg releasing msg %p\n", + gss_msg); + atomic_inc(&gss_msg->count); + gss_unhash_msg(gss_msg); + if (msg->errno == -ETIMEDOUT) { + unsigned long now = jiffies; + if (time_after(now, ratelimit)) { + printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n" + "Please check user daemon is running!\n"); + ratelimit = now + 15*HZ; + } + } + gss_release_msg(gss_msg); + } +} + +/* + * NOTE: we have the opportunity to use different + * parameters based on the input flavor (which must be a pseudoflavor) + */ +static struct rpc_auth * +gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) +{ + struct gss_auth *gss_auth; + struct rpc_auth * auth; + int err = -ENOMEM; /* XXX? */ + + dprintk("RPC: creating GSS authenticator for client %p\n", clnt); + + if (!try_module_get(THIS_MODULE)) + return ERR_PTR(err); + if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL))) + goto out_dec; + gss_auth->client = clnt; + err = -EINVAL; + gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor); + if (!gss_auth->mech) { + printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n", + __func__, flavor); + goto err_free; + } + gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor); + if (gss_auth->service == 0) + goto err_put_mech; + auth = &gss_auth->rpc_auth; + auth->au_cslack = GSS_CRED_SLACK >> 2; + auth->au_rslack = GSS_VERF_SLACK >> 2; + auth->au_ops = &authgss_ops; + auth->au_flavor = flavor; + atomic_set(&auth->au_count, 1); + kref_init(&gss_auth->kref); + + gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name, + clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN); + if (IS_ERR(gss_auth->dentry)) { + err = PTR_ERR(gss_auth->dentry); + goto err_put_mech; + } + + err = rpcauth_init_credcache(auth); + if (err) + goto err_unlink_pipe; + + return auth; +err_unlink_pipe: + rpc_unlink(gss_auth->dentry); +err_put_mech: + gss_mech_put(gss_auth->mech); +err_free: + kfree(gss_auth); +out_dec: + module_put(THIS_MODULE); + return ERR_PTR(err); +} + +static void +gss_free(struct gss_auth *gss_auth) +{ + rpc_unlink(gss_auth->dentry); + gss_auth->dentry = NULL; + gss_mech_put(gss_auth->mech); + + 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_destroy(struct rpc_auth *auth) +{ + struct gss_auth *gss_auth; + + dprintk("RPC: destroying GSS authenticator %p flavor %d\n", + auth, auth->au_flavor); + + rpcauth_destroy_credcache(auth); + + gss_auth = container_of(auth, struct gss_auth, rpc_auth); + kref_put(&gss_auth->kref, gss_free_callback); +} + +/* + * gss_destroying_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 int +gss_destroying_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 rpc_task *task; + + if (gss_cred->gc_ctx == NULL || + test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0) + return 0; + + gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY; + cred->cr_ops = &gss_nullops; + + /* Take a reference to ensure the cred will be destroyed either + * by the RPC call or by the put_rpccred() below */ + get_rpccred(cred); + + task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT); + if (!IS_ERR(task)) + rpc_put_task(task); + + put_rpccred(cred); + return 1; +} + +/* 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) +{ + dprintk("RPC: gss_free_ctx\n"); + + kfree(ctx->gc_wire_ctx.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) +{ + struct gss_ctx *gc_gss_ctx; + + gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx); + rcu_assign_pointer(ctx->gc_gss_ctx, NULL); + call_rcu(&ctx->gc_rcu, gss_free_ctx_callback); + if (gc_gss_ctx) + gss_delete_sec_context(&gc_gss_ctx); +} + +static void +gss_free_cred(struct gss_cred *gss_cred) +{ + dprintk("RPC: gss_free_cred %p\n", 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_cred(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 = gss_cred->gc_ctx; + + if (gss_destroying_context(cred)) + return; + rcu_assign_pointer(gss_cred->gc_ctx, NULL); + call_rcu(&cred->cr_rcu, gss_free_cred_callback); + if (ctx) + gss_put_ctx(ctx); + kref_put(&gss_auth->kref, gss_free_callback); +} + +/* + * 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); +} + +static struct rpc_cred * +gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) +{ + struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth); + struct gss_cred *cred = NULL; + int err = -ENOMEM; + + dprintk("RPC: gss_create_cred for uid %d, flavor %d\n", + acred->uid, auth->au_flavor); + + if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS))) + 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_machine_cred = acred->machine_cred; + kref_get(&gss_auth->kref); + return &cred->gc_base; + +out_err: + dprintk("RPC: gss_create_cred failed with error %d\n", 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 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); + + if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags)) + goto out; + /* Don't match with creds that have expired. */ + if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry)) + return 0; + if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags)) + return 0; +out: + if (acred->machine_cred != gss_cred->gc_machine_cred) + return 0; + return (rc->cr_uid == acred->uid); +} + +/* +* Marshal credentials. +* Maybe we should keep a cached credential for performance reasons. +*/ +static __be32 * +gss_marshal(struct rpc_task *task, __be32 *p) +{ + struct rpc_cred *cred = task->tk_msg.rpc_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 *cred_len; + struct rpc_rqst *req = task->tk_rqstp; + u32 maj_stat = 0; + struct xdr_netobj mic; + struct kvec iov; + struct xdr_buf verf_buf; + + dprintk("RPC: %5u gss_marshal\n", task->tk_pid); + + *p++ = htonl(RPC_AUTH_GSS); + cred_len = p++; + + spin_lock(&ctx->gc_seq_lock); + req->rq_seqno = ctx->gc_seq++; + spin_unlock(&ctx->gc_seq_lock); + + *p++ = htonl((u32) RPC_GSS_VERSION); + *p++ = htonl((u32) ctx->gc_proc); + *p++ = htonl((u32) req->rq_seqno); + *p++ = htonl((u32) gss_cred->gc_service); + p = xdr_encode_netobj(p, &ctx->gc_wire_ctx); + *cred_len = htonl((p - (cred_len + 1)) << 2); + + /* 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 = xprt_skip_transport_header(task->tk_xprt, + req->rq_snd_buf.head[0].iov_base); + iov.iov_len = (u8 *)p - (u8 *)iov.iov_base; + xdr_buf_from_iov(&iov, &verf_buf); + + /* set verifier flavor*/ + *p++ = htonl(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) { + clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); + } else if (maj_stat != 0) { + printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat); + goto out_put_ctx; + } + p = xdr_encode_opaque(p, NULL, mic.len); + gss_put_ctx(ctx); + return p; +out_put_ctx: + gss_put_ctx(ctx); + return NULL; +} + +static int gss_renew_cred(struct rpc_task *task) +{ + struct rpc_cred *oldcred = task->tk_msg.rpc_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 = { + .uid = oldcred->cr_uid, + .machine_cred = gss_cred->gc_machine_cred, + }; + struct rpc_cred *new; + + new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW); + if (IS_ERR(new)) + return PTR_ERR(new); + task->tk_msg.rpc_cred = new; + put_rpccred(oldcred); + return 0; +} + +/* +* Refresh credentials. XXX - finish +*/ +static int +gss_refresh(struct rpc_task *task) +{ + struct rpc_cred *cred = task->tk_msg.rpc_cred; + int ret = 0; + + 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_msg.rpc_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 -EACCES; +} + +static __be32 * +gss_validate(struct rpc_task *task, __be32 *p) +{ + struct rpc_cred *cred = task->tk_msg.rpc_cred; + struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); + __be32 seq; + struct kvec iov; + struct xdr_buf verf_buf; + struct xdr_netobj mic; + u32 flav,len; + u32 maj_stat; + + dprintk("RPC: %5u gss_validate\n", task->tk_pid); + + flav = ntohl(*p++); + if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE) + goto out_bad; + if (flav != RPC_AUTH_GSS) + goto out_bad; + seq = htonl(task->tk_rqstp->rq_seqno); + iov.iov_base = &seq; + iov.iov_len = sizeof(seq); + 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) { + dprintk("RPC: %5u gss_validate: gss_verify_mic returned " + "error 0x%08x\n", task->tk_pid, maj_stat); + goto out_bad; + } + /* 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; + gss_put_ctx(ctx); + dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n", + task->tk_pid); + return p + XDR_QUADLEN(len); +out_bad: + gss_put_ctx(ctx); + dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid); + return NULL; +} + +static inline int +gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, + kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj) +{ + struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; + struct xdr_buf integ_buf; + __be32 *integ_len = NULL; + struct xdr_netobj mic; + u32 offset; + __be32 *q; + struct kvec *iov; + u32 maj_stat = 0; + int status = -EIO; + + integ_len = p++; + offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; + *p++ = htonl(rqstp->rq_seqno); + + status = rpc_call_xdrproc(encode, rqstp, p, obj); + if (status) + return status; + + if (xdr_buf_subsegment(snd_buf, &integ_buf, + offset, snd_buf->len - offset)) + return status; + *integ_len = htonl(integ_buf.len); + + /* guess whether we're in 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; + mic.data = (u8 *)(p + 1); + + maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic); + status = -EIO; /* XXX? */ + if (maj_stat == GSS_S_CONTEXT_EXPIRED) + clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); + else if (maj_stat) + return status; + q = xdr_encode_opaque(p, NULL, mic.len); + + offset = (u8 *)q - (u8 *)p; + iov->iov_len += offset; + snd_buf->len += offset; + return 0; +} + +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); +} + +static int +alloc_enc_pages(struct rpc_rqst *rqstp) +{ + struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; + int first, last, i; + + if (snd_buf->page_len == 0) { + rqstp->rq_enc_pages_num = 0; + return 0; + } + + first = snd_buf->page_base >> PAGE_CACHE_SHIFT; + last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT; + rqstp->rq_enc_pages_num = last - first + 1 + 1; + rqstp->rq_enc_pages + = kmalloc(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: + for (i--; i >= 0; i--) { + __free_page(rqstp->rq_enc_pages[i]); + } +out: + return -EAGAIN; +} + +static inline int +gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, + kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj) +{ + struct xdr_buf *snd_buf = &rqstp->rq_snd_buf; + u32 offset; + u32 maj_stat; + int status; + __be32 *opaque_len; + struct page **inpages; + int first; + int pad; + struct kvec *iov; + char *tmp; + + opaque_len = p++; + offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base; + *p++ = htonl(rqstp->rq_seqno); + + status = rpc_call_xdrproc(encode, rqstp, p, obj); + if (status) + return status; + + status = alloc_enc_pages(rqstp); + if (status) + return status; + first = snd_buf->page_base >> PAGE_CACHE_SHIFT; + inpages = snd_buf->pages + first; + snd_buf->pages = rqstp->rq_enc_pages; + snd_buf->page_base -= first << PAGE_CACHE_SHIFT; + /* Give the tail its own page, in case we need extra space in the + * head when wrapping: */ + if (snd_buf->page_len || snd_buf->tail[0].iov_len) { + 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; + } + maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages); + /* RPC_SLACK_SPACE should prevent this ever happening: */ + BUG_ON(snd_buf->len > snd_buf->buflen); + status = -EIO; + /* 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) + return status; + + *opaque_len = htonl(snd_buf->len - offset); + /* guess whether we're in 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; +} + +static int +gss_wrap_req(struct rpc_task *task, + kxdrproc_t encode, void *rqstp, __be32 *p, void *obj) +{ + struct rpc_cred *cred = task->tk_msg.rpc_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; + + dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid); + 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 = rpc_call_xdrproc(encode, rqstp, p, obj); + goto out; + } + switch (gss_cred->gc_service) { + case RPC_GSS_SVC_NONE: + status = rpc_call_xdrproc(encode, rqstp, p, obj); + break; + case RPC_GSS_SVC_INTEGRITY: + status = gss_wrap_req_integ(cred, ctx, encode, + rqstp, p, obj); + break; + case RPC_GSS_SVC_PRIVACY: + status = gss_wrap_req_priv(cred, ctx, encode, + rqstp, p, obj); + break; + } +out: + gss_put_ctx(ctx); + dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status); + return status; +} + +static inline int +gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx, + struct rpc_rqst *rqstp, __be32 **p) +{ + struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; + struct xdr_buf integ_buf; + struct xdr_netobj mic; + u32 data_offset, mic_offset; + u32 integ_len; + u32 maj_stat; + int status = -EIO; + + integ_len = ntohl(*(*p)++); + if (integ_len & 3) + return status; + data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; + mic_offset = integ_len + data_offset; + if (mic_offset > rcv_buf->len) + return status; + if (ntohl(*(*p)++) != rqstp->rq_seqno) + return status; + + if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset, + mic_offset - data_offset)) + return status; + + if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset)) + return status; + + maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic); + if (maj_stat == GSS_S_CONTEXT_EXPIRED) + clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); + if (maj_stat != GSS_S_COMPLETE) + return status; + return 0; +} + +static inline int +gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, + struct rpc_rqst *rqstp, __be32 **p) +{ + struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf; + u32 offset; + u32 opaque_len; + u32 maj_stat; + int status = -EIO; + + opaque_len = ntohl(*(*p)++); + offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base; + if (offset + opaque_len > rcv_buf->len) + return status; + /* remove padding: */ + rcv_buf->len = offset + opaque_len; + + maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf); + if (maj_stat == GSS_S_CONTEXT_EXPIRED) + clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags); + if (maj_stat != GSS_S_COMPLETE) + return status; + if (ntohl(*(*p)++) != rqstp->rq_seqno) + return status; + + return 0; +} + + +static int +gss_unwrap_resp(struct rpc_task *task, + kxdrproc_t decode, void *rqstp, __be32 *p, void *obj) +{ + struct rpc_cred *cred = task->tk_msg.rpc_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 *savedp = p; + struct kvec *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head; + int savedlen = head->iov_len; + int status = -EIO; + + if (ctx->gc_proc != RPC_GSS_PROC_DATA) + goto out_decode; + switch (gss_cred->gc_service) { + case RPC_GSS_SVC_NONE: + break; + case RPC_GSS_SVC_INTEGRITY: + status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p); + if (status) + goto out; + break; + case RPC_GSS_SVC_PRIVACY: + status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p); + if (status) + goto out; + break; + } + /* take into account extra slack for integrity and privacy cases: */ + cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp) + + (savedlen - head->iov_len); +out_decode: + status = rpc_call_xdrproc(decode, rqstp, p, obj); +out: + gss_put_ctx(ctx); + dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid, + status); + 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, + .lookup_cred = gss_lookup_cred, + .crcreate = gss_create_cred +}; + +static const struct rpc_credops gss_credops = { + .cr_name = "AUTH_GSS", + .crdestroy = gss_destroy_cred, + .cr_init = gss_cred_init, + .crbind = rpcauth_generic_bind_cred, + .crmatch = gss_match, + .crmarshal = gss_marshal, + .crrefresh = gss_refresh, + .crvalidate = gss_validate, + .crwrap_req = gss_wrap_req, + .crunwrap_resp = gss_unwrap_resp, +}; + +static const struct rpc_credops gss_nullops = { + .cr_name = "AUTH_GSS", + .crdestroy = gss_destroy_cred, + .crbind = rpcauth_generic_bind_cred, + .crmatch = gss_match, + .crmarshal = gss_marshal, + .crrefresh = gss_refresh_null, + .crvalidate = gss_validate, + .crwrap_req = gss_wrap_req, + .crunwrap_resp = gss_unwrap_resp, +}; + +static struct rpc_pipe_ops gss_upcall_ops = { + .upcall = gss_pipe_upcall, + .downcall = gss_pipe_downcall, + .destroy_msg = gss_pipe_destroy_msg, + .release_pipe = gss_pipe_release, +}; + +/* + * 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; + return 0; +out_unregister: + rpcauth_unregister(&authgss_ops); +out: + return err; +} + +static void __exit exit_rpcsec_gss(void) +{ + gss_svc_shutdown(); + rpcauth_unregister(&authgss_ops); +} + +MODULE_LICENSE("GPL"); +module_init(init_rpcsec_gss) +module_exit(exit_rpcsec_gss) |
