svcauth.h

Go to the documentation of this file.

/*
 * linux/include/linux/sunrpc/svcauth.h
 *
 * RPC server-side authentication stuff.
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <[email protected]>
 */

#ifndef _LINUX_SUNRPC_SVCAUTH_H_
#define _LINUX_SUNRPC_SVCAUTH_H_

#ifdef __KERNEL__

#include <linux/string.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/cache.h>
#include <linux/hash.h>
#include <linux/cred.h>

struct svc_cred {
    uid_t           cr_uid;
    gid_t           cr_gid;
    struct group_info   *cr_group_info;
    u32         cr_flavor; /* pseudoflavor */
    char            *cr_principal; /* for gss */
};

static inline void free_svc_cred(struct svc_cred *cred)
{
    if (cred->cr_group_info)
        put_group_info(cred->cr_group_info);
    kfree(cred->cr_principal);
}

struct svc_rqst;        /* forward decl */
struct in6_addr;

/* Authentication is done in the context of a domain.
 *
 * Currently, the nfs server uses the auth_domain to stand
 * for the "client" listed in /etc/exports.
 *
 * More generally, a domain might represent a group of clients using
 * a common mechanism for authentication and having a common mapping
 * between local identity (uid) and network identity.  All clients
 * in a domain have similar general access rights.  Each domain can
 * contain multiple principals which will have different specific right
 * based on normal Discretionary Access Control.
 *
 * A domain is created by an authentication flavour module based on name
 * only.  Userspace then fills in detail on demand.
 *
 * In the case of auth_unix and auth_null, the auth_domain is also
 * associated with entries in another cache representing the mapping
 * of ip addresses to the given client.
 */
struct auth_domain {
    struct kref     ref;
    struct hlist_node   hash;
    char            *name;
    struct auth_ops     *flavour;
};

/*
 * Each authentication flavour registers an auth_ops
 * structure.
 * name is simply the name.
 * flavour gives the auth flavour. It determines where the flavour is registered
 * accept() is given a request and should verify it.
 *   It should inspect the authenticator and verifier, and possibly the data.
 *    If there is a problem with the authentication *authp should be set.
 *    The return value of accept() can indicate:
 *      OK - authorised. client and credential are set in rqstp.
 *           reqbuf points to arguments
 *           resbuf points to good place for results.  verfier
 *             is (probably) already in place.  Certainly space is
 *         reserved for it.
 *      DROP - simply drop the request. It may have been deferred
 *      GARBAGE - rpc garbage_args error
 *      SYSERR - rpc system_err error
 *      DENIED - authp holds reason for denial.
 *      COMPLETE - the reply is encoded already and ready to be sent; no
 *      further processing is necessary.  (This is used for processing
 *      null procedure calls which are used to set up encryption
 *      contexts.)
 *
 *   accept is passed the proc number so that it can accept NULL rpc requests
 *   even if it cannot authenticate the client (as is sometimes appropriate).
 *
 * release() is given a request after the procedure has been run.
 *  It should sign/encrypt the results if needed
 * It should return:
 *    OK - the resbuf is ready to be sent
 *    DROP - the reply should be quitely dropped
 *    DENIED - authp holds a reason for MSG_DENIED
 *    SYSERR - rpc system_err
 *
 * domain_release()
 *   This call releases a domain.
 * set_client()
 *   Givens a pending request (struct svc_rqst), finds and assigns
 *   an appropriate 'auth_domain' as the client.
 */
struct auth_ops {
    char *  name;
    struct module *owner;
    int flavour;
    int (*accept)(struct svc_rqst *rq, __be32 *authp);
    int (*release)(struct svc_rqst *rq);
    void    (*domain_release)(struct auth_domain *);
    int (*set_client)(struct svc_rqst *rq);
};

#define SVC_GARBAGE 1
#define SVC_SYSERR  2
#define SVC_VALID   3
#define SVC_NEGATIVE    4
#define SVC_OK      5
#define SVC_DROP    6
#define SVC_CLOSE   7   /* Like SVC_DROP, but request is definitely
                 * lost so if there is a tcp connection, it
                 * should be closed
                 */
#define SVC_DENIED  8
#define SVC_PENDING 9
#define SVC_COMPLETE    10

struct svc_xprt;

extern int  svc_authenticate(struct svc_rqst *rqstp, __be32 *authp);
extern int  svc_authorise(struct svc_rqst *rqstp);
extern int  svc_set_client(struct svc_rqst *rqstp);
extern int  svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops);
extern void svc_auth_unregister(rpc_authflavor_t flavor);

extern struct auth_domain *unix_domain_find(char *name);
extern void auth_domain_put(struct auth_domain *item);
extern int auth_unix_add_addr(struct net *net, struct in6_addr *addr, struct auth_domain *dom);
extern struct auth_domain *auth_domain_lookup(char *name, struct auth_domain *new);
extern struct auth_domain *auth_domain_find(char *name);
extern struct auth_domain *auth_unix_lookup(struct net *net, struct in6_addr *addr);
extern int auth_unix_forget_old(struct auth_domain *dom);
extern void svcauth_unix_purge(struct net *net);
extern void svcauth_unix_info_release(struct svc_xprt *xpt);
extern int svcauth_unix_set_client(struct svc_rqst *rqstp);

extern int unix_gid_cache_create(struct net *net);
extern void unix_gid_cache_destroy(struct net *net);

static inline unsigned long hash_str(char *name, int bits)
{
    unsigned long hash = 0;
    unsigned long l = 0;
    int len = 0;
    unsigned char c;
    do {
        if (unlikely(!(c = *name++))) {
            c = (char)len; len = -1;
        }
        l = (l << 8) | c;
        len++;
        if ((len & (BITS_PER_LONG/8-1))==0)
            hash = hash_long(hash^l, BITS_PER_LONG);
    } while (len);
    return hash >> (BITS_PER_LONG - bits);
}

static inline unsigned long hash_mem(char *buf, int length, int bits)
{
    unsigned long hash = 0;
    unsigned long l = 0;
    int len = 0;
    unsigned char c;
    do {
        if (len == length) {
            c = (char)len; len = -1;
        } else
            c = *buf++;
        l = (l << 8) | c;
        len++;
        if ((len & (BITS_PER_LONG/8-1))==0)
            hash = hash_long(hash^l, BITS_PER_LONG);
    } while (len);
    return hash >> (BITS_PER_LONG - bits);
}

#endif /* __KERNEL__ */

#endif /* _LINUX_SUNRPC_SVCAUTH_H_ */