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freebsd/sys/rpc/svc_auth_unix.c
Brooks Davis 838d985825 Rework the credential code to support larger values of NGROUPS and
NGROUPS_MAX, eliminate ABI dependencies on them, and raise the to 1024
and 1023 respectively.  (Previously they were equal, but under a close
reading of POSIX, NGROUPS_MAX was defined to be too large by 1 since it
is the number of supplemental groups, not total number of groups.)

The bulk of the change consists of converting the struct ucred member
cr_groups from a static array to a pointer.  Do the equivalent in
kinfo_proc.

Introduce new interfaces crcopysafe() and crsetgroups() for duplicating
a process credential before modifying it and for setting group lists
respectively.  Both interfaces take care for the details of allocating
groups array. crsetgroups() takes care of truncating the group list
to the current maximum (NGROUPS) if necessary.  In the future,
crsetgroups() may be responsible for insuring invariants such as sorting
the supplemental groups to allow groupmember() to be implemented as a
binary search.

Because we can not change struct xucred without breaking application
ABIs, we leave it alone and introduce a new XU_NGROUPS value which is
always 16 and is to be used or NGRPS as appropriate for things such as
NFS which need to use no more than 16 groups.  When feasible, truncate
the group list rather than generating an error.

Minor changes:
  - Reduce the number of hand rolled versions of groupmember().
  - Do not assign to both cr_gid and cr_groups[0].
  - Modify ipfw to cache ucreds instead of part of their contents since
    they are immutable once referenced by more than one entity.

Submitted by:	Isilon Systems (initial implementation)
X-MFC after:	never
PR:		bin/113398 kern/133867
2009-06-19 17:10:35 +00:00

144 lines
3.9 KiB
C

/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char *sccsid2 = "@(#)svc_auth_unix.c 1.28 88/02/08 Copyr 1984 Sun Micro";
static char *sccsid = "@(#)svc_auth_unix.c 2.3 88/08/01 4.0 RPCSRC";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* svc_auth_unix.c
* Handles UNIX flavor authentication parameters on the service side of rpc.
* There are two svc auth implementations here: AUTH_UNIX and AUTH_SHORT.
* _svcauth_unix does full blown unix style uid,gid+gids auth,
* _svcauth_short uses a shorthand auth to index into a cache of longhand auths.
* Note: the shorthand has been gutted for efficiency.
*
* Copyright (C) 1984, Sun Microsystems, Inc.
*/
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/ucred.h>
#include <rpc/rpc.h>
#include <rpc/rpc_com.h>
#define MAX_MACHINE_NAME 255
#define NGRPS 16
/*
* Unix longhand authenticator
*/
enum auth_stat
_svcauth_unix(struct svc_req *rqst, struct rpc_msg *msg)
{
enum auth_stat stat;
XDR xdrs;
int32_t *buf;
uint32_t time;
struct xucred *xcr;
u_int auth_len;
size_t str_len, gid_len;
u_int i;
xcr = rqst->rq_clntcred;
auth_len = (u_int)msg->rm_call.cb_cred.oa_length;
xdrmem_create(&xdrs, msg->rm_call.cb_cred.oa_base, auth_len,
XDR_DECODE);
buf = XDR_INLINE(&xdrs, auth_len);
if (buf != NULL) {
time = IXDR_GET_UINT32(buf);
str_len = (size_t)IXDR_GET_UINT32(buf);
if (str_len > MAX_MACHINE_NAME) {
stat = AUTH_BADCRED;
goto done;
}
str_len = RNDUP(str_len);
buf += str_len / sizeof (int32_t);
xcr->cr_uid = IXDR_GET_UINT32(buf);
xcr->cr_groups[0] = IXDR_GET_UINT32(buf);
gid_len = (size_t)IXDR_GET_UINT32(buf);
if (gid_len > NGRPS) {
stat = AUTH_BADCRED;
goto done;
}
for (i = 0; i < gid_len; i++) {
if (i + 1 < XU_NGROUPS)
xcr->cr_groups[i + 1] = IXDR_GET_INT32(buf);
else
buf++;
}
if (gid_len + 1 > XU_NGROUPS)
xcr->cr_ngroups = XU_NGROUPS;
else
xcr->cr_ngroups = gid_len + 1;
/*
* five is the smallest unix credentials structure -
* timestamp, hostname len (0), uid, gid, and gids len (0).
*/
if ((5 + gid_len) * BYTES_PER_XDR_UNIT + str_len > auth_len) {
(void) printf("bad auth_len gid %ld str %ld auth %u\n",
(long)gid_len, (long)str_len, auth_len);
stat = AUTH_BADCRED;
goto done;
}
} else if (! xdr_authunix_parms(&xdrs, &time, xcr)) {
stat = AUTH_BADCRED;
goto done;
}
rqst->rq_verf = _null_auth;
stat = AUTH_OK;
done:
XDR_DESTROY(&xdrs);
return (stat);
}
/*
* Shorthand unix authenticator
* Looks up longhand in a cache.
*/
/*ARGSUSED*/
enum auth_stat
_svcauth_short(rqst, msg)
struct svc_req *rqst;
struct rpc_msg *msg;
{
return (AUTH_REJECTEDCRED);
}