include/linux/sunrpc/svcauth.h

   1 /*
   2  * linux/include/linux/sunrpc/svcauth.h
   3  *
   4  * RPC server-side authentication stuff.
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #ifndef _LINUX_SUNRPC_SVCAUTH_H_
  10 #define _LINUX_SUNRPC_SVCAUTH_H_
  11
  12 #ifdef __KERNEL__
  13
  14 #include <linux/string.h>
  15 #include <linux/sunrpc/msg_prot.h>
  16 #include <linux/sunrpc/cache.h>
  17 #include <linux/hash.h>
  18
  19 #define SVC_CRED_NGROUPS        32
  20 struct svc_cred {
  21         uid_t                   cr_uid;
  22         gid_t                   cr_gid;
  23         struct group_info       *cr_group_info;
  24 };
  25
  26 struct svc_rqst;                /* forward decl */
  27
  28 /* Authentication is done in the context of a domain.
  29  *
  30  * Currently, the nfs server uses the auth_domain to stand
  31  * for the "client" listed in /etc/exports.
  32  *
  33  * More generally, a domain might represent a group of clients using
  34  * a common mechanism for authentication and having a common mapping
  35  * between local identity (uid) and network identity.  All clients
  36  * in a domain have similar general access rights.  Each domain can
  37  * contain multiple principals which will have different specific right
  38  * based on normal Discretionary Access Control.
  39  *
  40  * A domain is created by an authentication flavour module based on name
  41  * only.  Userspace then fills in detail on demand.
  42  *
  43  * In the case of auth_unix and auth_null, the auth_domain is also
  44  * associated with entries in another cache representing the mapping
  45  * of ip addresses to the given client.
  46  */
  47 struct auth_domain {
  48         struct kref             ref;
  49         struct hlist_node       hash;
  50         char                    *name;
  51         struct auth_ops         *flavour;
  52 };
  53
  54 /*
  55  * Each authentication flavour registers an auth_ops
  56  * structure.
  57  * name is simply the name.
  58  * flavour gives the auth flavour. It determines where the flavour is registered
  59  * accept() is given a request and should verify it.
  60  *   It should inspect the authenticator and verifier, and possibly the data.
  61  *    If there is a problem with the authentication *authp should be set.
  62  *    The return value of accept() can indicate:
  63  *      OK - authorised. client and credential are set in rqstp.
  64  *           reqbuf points to arguments
  65  *           resbuf points to good place for results.  verfier
  66  *             is (probably) already in place.  Certainly space is
  67  *             reserved for it.
  68  *      DROP - simply drop the request. It may have been deferred
  69  *      GARBAGE - rpc garbage_args error
  70  *      SYSERR - rpc system_err error
  71  *      DENIED - authp holds reason for denial.
  72  *      COMPLETE - the reply is encoded already and ready to be sent; no
  73  *              further processing is necessary.  (This is used for processing
  74  *              null procedure calls which are used to set up encryption
  75  *              contexts.)
  76  *
  77  *   accept is passed the proc number so that it can accept NULL rpc requests
  78  *   even if it cannot authenticate the client (as is sometimes appropriate).
  79  *
  80  * release() is given a request after the procedure has been run.
  81  *  It should sign/encrypt the results if needed
  82  * It should return:
  83  *    OK - the resbuf is ready to be sent
  84  *    DROP - the reply should be quitely dropped
  85  *    DENIED - authp holds a reason for MSG_DENIED
  86  *    SYSERR - rpc system_err
  87  *
  88  * domain_release()
  89  *   This call releases a domain.
  90  * set_client()
  91  *   Givens a pending request (struct svc_rqst), finds and assigns
  92  *   an appropriate 'auth_domain' as the client.
  93  */
  94 struct auth_ops {
  95         char *  name;
  96         struct module *owner;
  97         int     flavour;
  98         int     (*accept)(struct svc_rqst *rq, __be32 *authp);
  99         int     (*release)(struct svc_rqst *rq);
 100         void    (*domain_release)(struct auth_domain *);
 101         int     (*set_client)(struct svc_rqst *rq);
 102 };
 103
 104 #define SVC_GARBAGE     1
 105 #define SVC_SYSERR      2
 106 #define SVC_VALID       3
 107 #define SVC_NEGATIVE    4
 108 #define SVC_OK          5
 109 #define SVC_DROP        6
 110 #define SVC_DENIED      7
 111 #define SVC_PENDING     8
 112 #define SVC_COMPLETE    9
 113
 114
 115 extern int      svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
 116 extern int      svc_authorise(struct svc_rqst *rqstp);
 117 extern int      svc_set_client(struct svc_rqst *rqstp);
 118 extern int      svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
 119 extern void     svc_auth_unregister(rpc_authflavor_t flavor);
 120
 121 extern struct auth_domain *unix_domain_find(char *name);
 122 extern void auth_domain_put(struct auth_domain *item);
 123 extern int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom);
 124 extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
 125 extern struct auth_domain *auth_domain_find(char *name);
 126 extern struct auth_domain *auth_unix_lookup(struct in_addr addr);
 127 extern int auth_unix_forget_old(struct auth_domain *dom);
 128 extern void svcauth_unix_purge(void);
 129 extern void svcauth_unix_info_release(void *);
 130 extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
 131
 132 static inline unsigned long hash_str(char *name, int bits)
 133 {
 134         unsigned long hash = 0;
 135         unsigned long l = 0;
 136         int len = 0;
 137         unsigned char c;
 138         do {
 139                 if (unlikely(!(c = *name++))) {
 140                         c = (char)len; len = -1;
 141                 }
 142                 l = (l << 8) | c;
 143                 len++;
 144                 if ((len & (BITS_PER_LONG/8-1))==0)
 145                         hash = hash_long(hash^l, BITS_PER_LONG);
 146         } while (len);
 147         return hash >> (BITS_PER_LONG - bits);
 148 }
 149
 150 static inline unsigned long hash_mem(char *buf, int length, int bits)
 151 {
 152         unsigned long hash = 0;
 153         unsigned long l = 0;
 154         int len = 0;
 155         unsigned char c;
 156         do {
 157                 if (len == length) {
 158                         c = (char)len; len = -1;
 159                 } else
 160                         c = *buf++;
 161                 l = (l << 8) | c;
 162                 len++;
 163                 if ((len & (BITS_PER_LONG/8-1))==0)
 164                         hash = hash_long(hash^l, BITS_PER_LONG);
 165         } while (len);
 166         return hash >> (BITS_PER_LONG - bits);
 167 }
 168
 169 #endif /* __KERNEL__ */
 170
 171 #endif /* _LINUX_SUNRPC_SVCAUTH_H_ */