diff options
Diffstat (limited to 'kernel/net/sunrpc/auth_unix.c')
| -rw-r--r-- | kernel/net/sunrpc/auth_unix.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/kernel/net/sunrpc/auth_unix.c b/kernel/net/sunrpc/auth_unix.c new file mode 100644 index 000000000..4feda2d0a --- /dev/null +++ b/kernel/net/sunrpc/auth_unix.c @@ -0,0 +1,247 @@ +/* + * 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/sunrpc/clnt.h> +#include <linux/sunrpc/auth.h> +#include <linux/user_namespace.h> + +#define NFS_NGROUPS 16 + +struct unx_cred { + struct rpc_cred uc_base; + kgid_t uc_gid; + kgid_t uc_gids[NFS_NGROUPS]; +}; +#define uc_uid uc_base.cr_uid + +#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2)) + +#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 struct rpc_auth * +unx_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt) +{ + dprintk("RPC: creating UNIX authenticator for client %p\n", + clnt); + atomic_inc(&unix_auth.au_count); + return &unix_auth; +} + +static void +unx_destroy(struct rpc_auth *auth) +{ + dprintk("RPC: destroying UNIX authenticator %p\n", auth); + rpcauth_clear_credcache(auth->au_credcache); +} + +/* + * Lookup AUTH_UNIX creds for current process + */ +static struct rpc_cred * +unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) +{ + return rpcauth_lookup_credcache(auth, acred, flags); +} + +static struct rpc_cred * +unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) +{ + struct unx_cred *cred; + unsigned int groups = 0; + unsigned int i; + + dprintk("RPC: allocating UNIX cred for uid %d gid %d\n", + from_kuid(&init_user_ns, acred->uid), + from_kgid(&init_user_ns, acred->gid)); + + if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS))) + return ERR_PTR(-ENOMEM); + + rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops); + cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE; + + if (acred->group_info != NULL) + groups = acred->group_info->ngroups; + if (groups > NFS_NGROUPS) + groups = NFS_NGROUPS; + + cred->uc_gid = acred->gid; + for (i = 0; i < groups; i++) + cred->uc_gids[i] = GROUP_AT(acred->group_info, i); + if (i < NFS_NGROUPS) + cred->uc_gids[i] = INVALID_GID; + + return &cred->uc_base; +} + +static void +unx_free_cred(struct unx_cred *unx_cred) +{ + dprintk("RPC: unx_free_cred %p\n", unx_cred); + kfree(unx_cred); +} + +static void +unx_free_cred_callback(struct rcu_head *head) +{ + struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu); + unx_free_cred(unx_cred); +} + +static void +unx_destroy_cred(struct rpc_cred *cred) +{ + call_rcu(&cred->cr_rcu, unx_free_cred_callback); +} + +/* + * Match credentials against current process creds. + * The root_override argument takes care of cases where the caller may + * request root creds (e.g. for NFS swapping). + */ +static int +unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags) +{ + struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base); + unsigned int groups = 0; + unsigned int i; + + + if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid)) + return 0; + + if (acred->group_info != NULL) + groups = acred->group_info->ngroups; + if (groups > NFS_NGROUPS) + groups = NFS_NGROUPS; + for (i = 0; i < groups ; i++) + if (!gid_eq(cred->uc_gids[i], GROUP_AT(acred->group_info, i))) + return 0; + if (groups < NFS_NGROUPS && gid_valid(cred->uc_gids[groups])) + return 0; + return 1; +} + +/* + * Marshal credentials. + * Maybe we should keep a cached credential for performance reasons. + */ +static __be32 * +unx_marshal(struct rpc_task *task, __be32 *p) +{ + struct rpc_clnt *clnt = task->tk_client; + struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base); + __be32 *base, *hold; + int i; + + *p++ = htonl(RPC_AUTH_UNIX); + base = p++; + *p++ = htonl(jiffies/HZ); + + /* + * Copy the UTS nodename captured when the client was created. + */ + p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); + + *p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid)); + *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid)); + hold = p++; + for (i = 0; i < 16 && gid_valid(cred->uc_gids[i]); i++) + *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i])); + *hold = htonl(p - hold - 1); /* gid array length */ + *base = htonl((p - base - 1) << 2); /* cred length */ + + *p++ = htonl(RPC_AUTH_NULL); + *p++ = htonl(0); + + return p; +} + +/* + * 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 __be32 * +unx_validate(struct rpc_task *task, __be32 *p) +{ + rpc_authflavor_t flavor; + u32 size; + + flavor = ntohl(*p++); + if (flavor != RPC_AUTH_NULL && + flavor != RPC_AUTH_UNIX && + flavor != RPC_AUTH_SHORT) { + printk("RPC: bad verf flavor: %u\n", flavor); + return ERR_PTR(-EIO); + } + + size = ntohl(*p++); + if (size > RPC_MAX_AUTH_SIZE) { + printk("RPC: giant verf size: %u\n", size); + return ERR_PTR(-EIO); + } + task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2; + p += (size >> 2); + + return p; +} + +int __init rpc_init_authunix(void) +{ + return rpcauth_init_credcache(&unix_auth); +} + +void rpc_destroy_authunix(void) +{ + rpcauth_destroy_credcache(&unix_auth); +} + +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, + .crcreate = unx_create_cred, +}; + +static +struct rpc_auth unix_auth = { + .au_cslack = UNX_WRITESLACK, + .au_rslack = 2, /* assume AUTH_NULL verf */ + .au_ops = &authunix_ops, + .au_flavor = RPC_AUTH_UNIX, + .au_count = ATOMIC_INIT(0), +}; + +static +const struct rpc_credops unix_credops = { + .cr_name = "AUTH_UNIX", + .crdestroy = unx_destroy_cred, + .crbind = rpcauth_generic_bind_cred, + .crmatch = unx_match, + .crmarshal = unx_marshal, + .crrefresh = unx_refresh, + .crvalidate = unx_validate, +}; |