/* * linux/net/sunrpc/auth_unix.c * * UNIX-style authentication; no AUTH_SHORT support * * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> */ #include <linux/types.h> #include <linux/sched.h> #include <linux/module.h> #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/auth.h> #define NFS_NGROUPS 16 struct unx_cred { struct rpc_cred uc_base; gid_t uc_gid; gid_t uc_gids[NFS_NGROUPS]; }; #define uc_uid uc_base.cr_uid #define uc_count uc_base.cr_count #define uc_flags uc_base.cr_flags #define uc_expire uc_base.cr_expire #define UNX_CRED_EXPIRE (60 * HZ) #define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2)) #ifdef RPC_DEBUG # define RPCDBG_FACILITY RPCDBG_AUTH #endif static struct rpc_auth unix_auth; static struct rpc_cred_cache unix_cred_cache; static struct rpc_credops unix_credops; static struct rpc_auth * unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) { dprintk("RPC: creating UNIX authenticator for client %p\n", clnt); if (atomic_inc_return(&unix_auth.au_count) == 0) unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1); return &unix_auth; } static void unx_destroy(struct rpc_auth *auth) { dprintk("RPC: destroying UNIX authenticator %p\n", auth); rpcauth_free_credcache(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) { 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; int i; dprintk("RPC: allocating UNIX cred for uid %d gid %d\n", acred->uid, acred->gid); if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL))) return ERR_PTR(-ENOMEM); atomic_set(&cred->uc_count, 1); cred->uc_flags = RPCAUTH_CRED_UPTODATE; if (flags & RPCAUTH_LOOKUP_ROOTCREDS) { cred->uc_uid = 0; cred->uc_gid = 0; cred->uc_gids[0] = NOGROUP; } else { int groups = acred->group_info->ngroups; if (groups > NFS_NGROUPS) groups = NFS_NGROUPS; cred->uc_uid = acred->uid; 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] = NOGROUP; } cred->uc_base.cr_ops = &unix_credops; return (struct rpc_cred *) cred; } static void unx_destroy_cred(struct rpc_cred *cred) { kfree(cred); } /* * 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 = (struct unx_cred *) rcred; int i; if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS)) { int groups; if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid) return 0; groups = acred->group_info->ngroups; if (groups > NFS_NGROUPS) groups = NFS_NGROUPS; for (i = 0; i < groups ; i++) if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i)) return 0; return 1; } return (cred->uc_uid == 0 && cred->uc_gid == 0 && cred->uc_gids[0] == (gid_t) NOGROUP); } /* * 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 = (struct unx_cred *) task->tk_msg.rpc_cred; __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) cred->uc_uid); *p++ = htonl((u32) cred->uc_gid); hold = p++; for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++) *p++ = htonl((u32) 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) { task->tk_msg.rpc_cred->cr_flags |= RPCAUTH_CRED_UPTODATE; 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 NULL; } size = ntohl(*p++); if (size > RPC_MAX_AUTH_SIZE) { printk("RPC: giant verf size: %u\n", size); return NULL; } task->tk_auth->au_rslack = (size >> 2) + 2; p += (size >> 2); return p; } struct rpc_authops authunix_ops = { .owner = THIS_MODULE, .au_flavor = RPC_AUTH_UNIX, #ifdef RPC_DEBUG .au_name = "UNIX", #endif .create = unx_create, .destroy = unx_destroy, .lookup_cred = unx_lookup_cred, .crcreate = unx_create_cred, }; static struct rpc_cred_cache unix_cred_cache = { .expire = UNX_CRED_EXPIRE, }; 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), .au_credcache = &unix_cred_cache, }; static struct rpc_credops unix_credops = { .cr_name = "AUTH_UNIX", .crdestroy = unx_destroy_cred, .crmatch = unx_match, .crmarshal = unx_marshal, .crrefresh = unx_refresh, .crvalidate = unx_validate, };