diff options
Diffstat (limited to 'net/sunrpc/auth_unix.c')
| -rw-r--r-- | net/sunrpc/auth_unix.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c new file mode 100644 index 000000000..1e091d3fa --- /dev/null +++ b/net/sunrpc/auth_unix.c @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/net/sunrpc/auth_unix.c + * + * UNIX-style authentication; no AUTH_SHORT support + * + * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> + */ + +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/sched.h> +#include <linux/module.h> +#include <linux/mempool.h> +#include <linux/sunrpc/clnt.h> +#include <linux/sunrpc/auth.h> +#include <linux/user_namespace.h> + + +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) +# define RPCDBG_FACILITY RPCDBG_AUTH +#endif + +static struct rpc_auth unix_auth; +static const struct rpc_credops unix_credops; +static mempool_t *unix_pool; + +static struct rpc_auth * +unx_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt) +{ + refcount_inc(&unix_auth.au_count); + return &unix_auth; +} + +static void +unx_destroy(struct rpc_auth *auth) +{ +} + +/* + * Lookup AUTH_UNIX creds for current process + */ +static struct rpc_cred *unx_lookup_cred(struct rpc_auth *auth, + struct auth_cred *acred, int flags) +{ + struct rpc_cred *ret; + + ret = kmalloc(sizeof(*ret), rpc_task_gfp_mask()); + if (!ret) { + if (!(flags & RPCAUTH_LOOKUP_ASYNC)) + return ERR_PTR(-ENOMEM); + ret = mempool_alloc(unix_pool, GFP_NOWAIT); + if (!ret) + return ERR_PTR(-ENOMEM); + } + rpcauth_init_cred(ret, acred, auth, &unix_credops); + ret->cr_flags = 1UL << RPCAUTH_CRED_UPTODATE; + return ret; +} + +static void +unx_free_cred_callback(struct rcu_head *head) +{ + struct rpc_cred *rpc_cred = container_of(head, struct rpc_cred, cr_rcu); + + put_cred(rpc_cred->cr_cred); + mempool_free(rpc_cred, unix_pool); +} + +static void +unx_destroy_cred(struct rpc_cred *cred) +{ + call_rcu(&cred->cr_rcu, unx_free_cred_callback); +} + +/* + * Match credentials against current the auth_cred. + */ +static int +unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags) +{ + unsigned int groups = 0; + unsigned int i; + + if (cred->cr_cred == acred->cred) + return 1; + + if (!uid_eq(cred->cr_cred->fsuid, acred->cred->fsuid) || !gid_eq(cred->cr_cred->fsgid, acred->cred->fsgid)) + return 0; + + if (acred->cred->group_info != NULL) + groups = acred->cred->group_info->ngroups; + if (groups > UNX_NGROUPS) + groups = UNX_NGROUPS; + if (cred->cr_cred->group_info == NULL) + return groups == 0; + if (groups != cred->cr_cred->group_info->ngroups) + return 0; + + for (i = 0; i < groups ; i++) + if (!gid_eq(cred->cr_cred->group_info->gid[i], acred->cred->group_info->gid[i])) + return 0; + return 1; +} + +/* + * Marshal credentials. + * Maybe we should keep a cached credential for performance reasons. + */ +static int +unx_marshal(struct rpc_task *task, struct xdr_stream *xdr) +{ + struct rpc_clnt *clnt = task->tk_client; + struct rpc_cred *cred = task->tk_rqstp->rq_cred; + __be32 *p, *cred_len, *gidarr_len; + int i; + struct group_info *gi = cred->cr_cred->group_info; + struct user_namespace *userns = clnt->cl_cred ? + clnt->cl_cred->user_ns : &init_user_ns; + + /* Credential */ + + p = xdr_reserve_space(xdr, 3 * sizeof(*p)); + if (!p) + goto marshal_failed; + *p++ = rpc_auth_unix; + cred_len = p++; + *p++ = xdr_zero; /* stamp */ + if (xdr_stream_encode_opaque(xdr, clnt->cl_nodename, + clnt->cl_nodelen) < 0) + goto marshal_failed; + p = xdr_reserve_space(xdr, 3 * sizeof(*p)); + if (!p) + goto marshal_failed; + *p++ = cpu_to_be32(from_kuid_munged(userns, cred->cr_cred->fsuid)); + *p++ = cpu_to_be32(from_kgid_munged(userns, cred->cr_cred->fsgid)); + + gidarr_len = p++; + if (gi) + for (i = 0; i < UNX_NGROUPS && i < gi->ngroups; i++) + *p++ = cpu_to_be32(from_kgid_munged(userns, gi->gid[i])); + *gidarr_len = cpu_to_be32(p - gidarr_len - 1); + *cred_len = cpu_to_be32((p - cred_len - 1) << 2); + p = xdr_reserve_space(xdr, (p - gidarr_len - 1) << 2); + if (!p) + goto marshal_failed; + + /* Verifier */ + + p = xdr_reserve_space(xdr, 2 * sizeof(*p)); + if (!p) + goto marshal_failed; + *p++ = rpc_auth_null; + *p = xdr_zero; + + return 0; + +marshal_failed: + return -EMSGSIZE; +} + +/* + * Refresh credentials. This is a no-op for AUTH_UNIX + */ +static int +unx_refresh(struct rpc_task *task) +{ + set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags); + return 0; +} + +static int +unx_validate(struct rpc_task *task, struct xdr_stream *xdr) +{ + struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth; + __be32 *p; + u32 size; + + p = xdr_inline_decode(xdr, 2 * sizeof(*p)); + if (!p) + return -EIO; + switch (*p++) { + case rpc_auth_null: + case rpc_auth_unix: + case rpc_auth_short: + break; + default: + return -EIO; + } + size = be32_to_cpup(p); + if (size > RPC_MAX_AUTH_SIZE) + return -EIO; + p = xdr_inline_decode(xdr, size); + if (!p) + return -EIO; + + auth->au_verfsize = XDR_QUADLEN(size) + 2; + auth->au_rslack = XDR_QUADLEN(size) + 2; + auth->au_ralign = XDR_QUADLEN(size) + 2; + return 0; +} + +int __init rpc_init_authunix(void) +{ + unix_pool = mempool_create_kmalloc_pool(16, sizeof(struct rpc_cred)); + return unix_pool ? 0 : -ENOMEM; +} + +void rpc_destroy_authunix(void) +{ + mempool_destroy(unix_pool); +} + +const struct rpc_authops authunix_ops = { + .owner = THIS_MODULE, + .au_flavor = RPC_AUTH_UNIX, + .au_name = "UNIX", + .create = unx_create, + .destroy = unx_destroy, + .lookup_cred = unx_lookup_cred, +}; + +static +struct rpc_auth unix_auth = { + .au_cslack = UNX_CALLSLACK, + .au_rslack = NUL_REPLYSLACK, + .au_verfsize = NUL_REPLYSLACK, + .au_ops = &authunix_ops, + .au_flavor = RPC_AUTH_UNIX, + .au_count = REFCOUNT_INIT(1), +}; + +static +const struct rpc_credops unix_credops = { + .cr_name = "AUTH_UNIX", + .crdestroy = unx_destroy_cred, + .crmatch = unx_match, + .crmarshal = unx_marshal, + .crwrap_req = rpcauth_wrap_req_encode, + .crrefresh = unx_refresh, + .crvalidate = unx_validate, + .crunwrap_resp = rpcauth_unwrap_resp_decode, +}; |