| /* |
| * Generic RPC credential |
| * |
| * Copyright (C) 2008, Trond Myklebust <Trond.Myklebust@netapp.com> |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/sunrpc/auth.h> |
| #include <linux/sunrpc/clnt.h> |
| #include <linux/sunrpc/debug.h> |
| #include <linux/sunrpc/sched.h> |
| |
| #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
| # define RPCDBG_FACILITY RPCDBG_AUTH |
| #endif |
| |
| #define RPC_MACHINE_CRED_USERID GLOBAL_ROOT_UID |
| #define RPC_MACHINE_CRED_GROUPID GLOBAL_ROOT_GID |
| |
| struct generic_cred { |
| struct rpc_cred gc_base; |
| struct auth_cred acred; |
| }; |
| |
| static struct rpc_auth generic_auth; |
| static const struct rpc_credops generic_credops; |
| |
| /* |
| * Public call interface |
| */ |
| struct rpc_cred *rpc_lookup_cred(void) |
| { |
| return rpcauth_lookupcred(&generic_auth, 0); |
| } |
| EXPORT_SYMBOL_GPL(rpc_lookup_cred); |
| |
| struct rpc_cred * |
| rpc_lookup_generic_cred(struct auth_cred *acred, int flags, gfp_t gfp) |
| { |
| return rpcauth_lookup_credcache(&generic_auth, acred, flags, gfp); |
| } |
| EXPORT_SYMBOL_GPL(rpc_lookup_generic_cred); |
| |
| struct rpc_cred *rpc_lookup_cred_nonblock(void) |
| { |
| return rpcauth_lookupcred(&generic_auth, RPCAUTH_LOOKUP_RCU); |
| } |
| EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock); |
| |
| /* |
| * Public call interface for looking up machine creds. |
| */ |
| struct rpc_cred *rpc_lookup_machine_cred(const char *service_name) |
| { |
| struct auth_cred acred = { |
| .uid = RPC_MACHINE_CRED_USERID, |
| .gid = RPC_MACHINE_CRED_GROUPID, |
| .principal = service_name, |
| .machine_cred = 1, |
| }; |
| |
| dprintk("RPC: looking up machine cred for service %s\n", |
| service_name); |
| return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0); |
| } |
| EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred); |
| |
| static struct rpc_cred *generic_bind_cred(struct rpc_task *task, |
| struct rpc_cred *cred, int lookupflags) |
| { |
| struct rpc_auth *auth = task->tk_client->cl_auth; |
| struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred; |
| |
| return auth->au_ops->lookup_cred(auth, acred, lookupflags); |
| } |
| |
| static int |
| generic_hash_cred(struct auth_cred *acred, unsigned int hashbits) |
| { |
| return hash_64(from_kgid(&init_user_ns, acred->gid) | |
| ((u64)from_kuid(&init_user_ns, acred->uid) << |
| (sizeof(gid_t) * 8)), hashbits); |
| } |
| |
| /* |
| * Lookup generic creds for current process |
| */ |
| static struct rpc_cred * |
| generic_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) |
| { |
| return rpcauth_lookup_credcache(&generic_auth, acred, flags, GFP_KERNEL); |
| } |
| |
| static struct rpc_cred * |
| generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp) |
| { |
| struct generic_cred *gcred; |
| |
| gcred = kmalloc(sizeof(*gcred), gfp); |
| if (gcred == NULL) |
| return ERR_PTR(-ENOMEM); |
| |
| rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops); |
| gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE; |
| |
| gcred->acred.uid = acred->uid; |
| gcred->acred.gid = acred->gid; |
| gcred->acred.group_info = acred->group_info; |
| gcred->acred.ac_flags = 0; |
| if (gcred->acred.group_info != NULL) |
| get_group_info(gcred->acred.group_info); |
| gcred->acred.machine_cred = acred->machine_cred; |
| gcred->acred.principal = acred->principal; |
| |
| dprintk("RPC: allocated %s cred %p for uid %d gid %d\n", |
| gcred->acred.machine_cred ? "machine" : "generic", |
| gcred, |
| from_kuid(&init_user_ns, acred->uid), |
| from_kgid(&init_user_ns, acred->gid)); |
| return &gcred->gc_base; |
| } |
| |
| static void |
| generic_free_cred(struct rpc_cred *cred) |
| { |
| struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base); |
| |
| dprintk("RPC: generic_free_cred %p\n", gcred); |
| if (gcred->acred.group_info != NULL) |
| put_group_info(gcred->acred.group_info); |
| kfree(gcred); |
| } |
| |
| static void |
| generic_free_cred_callback(struct rcu_head *head) |
| { |
| struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu); |
| generic_free_cred(cred); |
| } |
| |
| static void |
| generic_destroy_cred(struct rpc_cred *cred) |
| { |
| call_rcu(&cred->cr_rcu, generic_free_cred_callback); |
| } |
| |
| static int |
| machine_cred_match(struct auth_cred *acred, struct generic_cred *gcred, int flags) |
| { |
| if (!gcred->acred.machine_cred || |
| gcred->acred.principal != acred->principal || |
| !uid_eq(gcred->acred.uid, acred->uid) || |
| !gid_eq(gcred->acred.gid, acred->gid)) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * Match credentials against current process creds. |
| */ |
| static int |
| generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags) |
| { |
| struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base); |
| int i; |
| |
| if (acred->machine_cred) |
| return machine_cred_match(acred, gcred, flags); |
| |
| if (!uid_eq(gcred->acred.uid, acred->uid) || |
| !gid_eq(gcred->acred.gid, acred->gid) || |
| gcred->acred.machine_cred != 0) |
| goto out_nomatch; |
| |
| /* Optimisation in the case where pointers are identical... */ |
| if (gcred->acred.group_info == acred->group_info) |
| goto out_match; |
| |
| /* Slow path... */ |
| if (gcred->acred.group_info->ngroups != acred->group_info->ngroups) |
| goto out_nomatch; |
| for (i = 0; i < gcred->acred.group_info->ngroups; i++) { |
| if (!gid_eq(gcred->acred.group_info->gid[i], |
| acred->group_info->gid[i])) |
| goto out_nomatch; |
| } |
| out_match: |
| return 1; |
| out_nomatch: |
| return 0; |
| } |
| |
| int __init rpc_init_generic_auth(void) |
| { |
| return rpcauth_init_credcache(&generic_auth); |
| } |
| |
| void rpc_destroy_generic_auth(void) |
| { |
| rpcauth_destroy_credcache(&generic_auth); |
| } |
| |
| /* |
| * Test the the current time (now) against the underlying credential key expiry |
| * minus a timeout and setup notification. |
| * |
| * The normal case: |
| * If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set |
| * the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential |
| * rpc_credops crmatch routine to notify this generic cred when it's key |
| * expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0. |
| * |
| * The error case: |
| * If the underlying cred lookup fails, return -EACCES. |
| * |
| * The 'almost' error case: |
| * If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within |
| * key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit |
| * on the acred ac_flags and return 0. |
| */ |
| static int |
| generic_key_timeout(struct rpc_auth *auth, struct rpc_cred *cred) |
| { |
| struct auth_cred *acred = &container_of(cred, struct generic_cred, |
| gc_base)->acred; |
| struct rpc_cred *tcred; |
| int ret = 0; |
| |
| |
| /* Fast track for non crkey_timeout (no key) underlying credentials */ |
| if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT) |
| return 0; |
| |
| /* Fast track for the normal case */ |
| if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags)) |
| return 0; |
| |
| /* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */ |
| tcred = auth->au_ops->lookup_cred(auth, acred, 0); |
| if (IS_ERR(tcred)) |
| return -EACCES; |
| |
| /* Test for the almost error case */ |
| ret = tcred->cr_ops->crkey_timeout(tcred); |
| if (ret != 0) { |
| set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags); |
| ret = 0; |
| } else { |
| /* In case underlying cred key has been reset */ |
| if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON, |
| &acred->ac_flags)) |
| dprintk("RPC: UID %d Credential key reset\n", |
| from_kuid(&init_user_ns, tcred->cr_uid)); |
| /* set up fasttrack for the normal case */ |
| set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags); |
| } |
| |
| put_rpccred(tcred); |
| return ret; |
| } |
| |
| static const struct rpc_authops generic_auth_ops = { |
| .owner = THIS_MODULE, |
| .au_name = "Generic", |
| .hash_cred = generic_hash_cred, |
| .lookup_cred = generic_lookup_cred, |
| .crcreate = generic_create_cred, |
| .key_timeout = generic_key_timeout, |
| }; |
| |
| static struct rpc_auth generic_auth = { |
| .au_ops = &generic_auth_ops, |
| .au_count = REFCOUNT_INIT(1), |
| }; |
| |
| static bool generic_key_to_expire(struct rpc_cred *cred) |
| { |
| struct auth_cred *acred = &container_of(cred, struct generic_cred, |
| gc_base)->acred; |
| return test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags); |
| } |
| |
| static const struct rpc_credops generic_credops = { |
| .cr_name = "Generic cred", |
| .crdestroy = generic_destroy_cred, |
| .crbind = generic_bind_cred, |
| .crmatch = generic_match, |
| .crkey_to_expire = generic_key_to_expire, |
| }; |