Date: Wed, 19 Dec 2001 00:54:07 +0000 From: Dima Dorfman <dima@trit.org> To: Robert Watson <rwatson@freebsd.org>, "Brian F. Feldman" <green@freebsd.org> Cc: arch@freebsd.org Subject: xucred versioning and filling (was: MFC'ing xucred definition) Message-ID: <20011219005412.54A833E2F@bazooka.trit.org>
next in thread | raw e-mail | index | archive | help
Does anybody have any comments on this? I'd like to commit it
soon-ish, but don't plan to MFC it before 4.5 (since it's a new
interface, and I'd rather not set it in stone (-stable) yet).
Thanks.
I wrote:
> Robert Watson <rwatson@freebsd.org> wrote:
> > On Fri, 14 Dec 2001, Dima Dorfman wrote:
> > > rwatson wrote:
> > > > Actually, the one thing I'd like to see before we move forward
> > > > is a standard routine that accepts a ucred, and a *xucred, and
> > > > fills out the xucred using the ucred (preferably, in
> > > > kern_prot.c). Right now, xucred is filled out in various
> > > > places manually (netinet, socket code, et al). As we begin to
> > > > broaden the scope of xucred (for example, I'd like to push in
> > > > the ruid and rgid), it will make things a lot easier, and also
> > > > prevent more code from knowing much about the innards of
> > > > ucred. That way, also, the version number can be kept in one
> > > > place.
> > >
> > > I had patches to add this routine (and vice versa, xucred->ucred)
> > > before you added the extra fields to ucred, at which point I dropped it
> > > since it didn't make much sense: Which fields do you copy? Effective,
> > > real, or saved {u,g}ids? It would again make sense if xucred had the
> > > same set of fields as ucred, however.
> >
> > It's always been euid in ucred previously, so I assumed that for version 0
> > of xucred, only euid and egid (plus additional groups) would be exported.
> > Future versions of xucred (probably version 1, only in -CURRENT) would
> > also be able to export ruid, svuid, rgid, and svgid.
>
> Very well. The attached patch adds two routines, cru2x() and crx2u()
> which convert from a ucred to xucred and vice versa, respectively.
> cru2x() sets the version number, and crx2u() checks it. If the check
> fails, it returns EINVAL. I'm not sure if there's a better way to do
> this error passing, since it seems that none of the other cr*()
> routines return an error code.
>
> The userland parts remain unchanged from my previous patches.
>
> Index: lib/libc/gen/getpeereid.3
> ===================================================================
> RCS file: /ref/cvsf/src/lib/libc/gen/getpeereid.3,v
> retrieving revision 1.3
> diff -u -r1.3 getpeereid.3
> --- lib/libc/gen/getpeereid.3 2001/12/02 23:50:40 1.3
> +++ lib/libc/gen/getpeereid.3 2001/12/14 01:20:17
> @@ -118,7 +118,8 @@
> The argument
> .Fa s
> does not refer to a socket of type
> -.Dv SOCK_STREAM .
> +.Dv SOCK_STREAM ,
> +or the kernel returned invalid data.
> .El
> .Sh SEE ALSO
> .Xr connect 2 ,
> Index: lib/libc/gen/getpeereid.c
> ===================================================================
> RCS file: /ref/cvsf/src/lib/libc/gen/getpeereid.c,v
> retrieving revision 1.1
> diff -u -r1.1 getpeereid.c
> --- lib/libc/gen/getpeereid.c 2001/08/17 22:09:15 1.1
> +++ lib/libc/gen/getpeereid.c 2001/12/14 01:20:17
> @@ -34,6 +34,7 @@
> #include <sys/ucred.h>
> #include <sys/un.h>
>
> +#include <errno.h>
> #include <unistd.h>
>
> int
> @@ -47,6 +48,8 @@
> error = getsockopt(s, LOCAL_PEERCRED, 1, &xuc, &xuclen);
> if (error != 0)
> return (error);
> + if (xuc.cr_version != XUCRED_VERSION)
> + return (EINVAL);
> *euid = xuc.cr_uid;
> *egid = xuc.cr_gid;
> return (0);
> Index: sbin/mountd/mountd.c
> ===================================================================
> RCS file: /ref/cvsf/src/sbin/mountd/mountd.c,v
> retrieving revision 1.59
> diff -u -r1.59 mountd.c
> --- sbin/mountd/mountd.c 2001/09/20 02:15:17 1.59
> +++ sbin/mountd/mountd.c 2001/12/14 01:20:17
> @@ -211,7 +211,7 @@
> struct grouplist *grphead;
> char exname[MAXPATHLEN];
> struct xucred def_anon = {
> - 0,
> + XUCRED_VERSION,
> (uid_t)-2,
> 1,
> { (gid_t)-2 },
> @@ -2050,6 +2050,7 @@
> struct group *gr;
> int ngroups, groups[NGROUPS + 1];
>
> + cr->cr_version = XUCRED_VERSION;
> /*
> * Set up the unprivileged user.
> */
> Index: sys/kern/kern_prot.c
> ===================================================================
> RCS file: /ref/cvsf/src/sys/kern/kern_prot.c,v
> retrieving revision 1.131
> diff -u -r1.131 kern_prot.c
> --- sys/kern/kern_prot.c 2001/12/06 21:58:47 1.131
> +++ sys/kern/kern_prot.c 2001/12/14 03:30:55
> @@ -1670,6 +1670,41 @@
> }
>
> /*
> + * Fill in a struct xucred based on a struct ucred.
> + */
> +void
> +cru2x(cr, xcr)
> + struct ucred *cr;
> + struct xucred *xcr;
> +{
> +
> + bzero(xcr, sizeof(*xcr));
> + xcr->cr_version = XUCRED_VERSION;
> + xcr->cr_uid = cr->cr_uid;
> + xcr->cr_ngroups = cr->cr_ngroups;
> + bcopy(cr->cr_groups, xcr->cr_groups, sizeof(cr->cr_groups));
> +}
> +
> +/*
> + * Copy information out of a struct xucred into a struct ucred. This
> + * routine does *not* initialize (zero) the output structure (cr)
> + * because that's the job of crget() or crdup().
> + */
> +int
> +crx2u(xcr, cr)
> + struct xucred *xcr;
> + struct ucred *cr;
> +{
> +
> + if (xcr->cr_version != XUCRED_VERSION)
> + return (EINVAL);
> + cr->cr_uid = xcr->cr_uid;
> + cr->cr_ngroups = xcr->cr_ngroups;
> + bcopy(xcr->cr_groups, cr->cr_groups, sizeof(xcr->cr_groups));
> + return (0);
> +}
> +
> +/*
> * Get login name, if available.
> */
> #ifndef _SYS_SYSPROTO_H_
> Index: sys/kern/uipc_usrreq.c
> ===================================================================
> RCS file: /ref/cvsf/src/sys/kern/uipc_usrreq.c,v
> retrieving revision 1.78
> diff -u -r1.78 uipc_usrreq.c
> --- sys/kern/uipc_usrreq.c 2001/12/13 22:09:37 1.78
> +++ sys/kern/uipc_usrreq.c 2001/12/14 03:33:12
> @@ -710,11 +710,7 @@
> * from its process structure at the time of connect()
> * (which is now).
> */
- memset(&unp3->unp_peercred, '\0', sizeof(unp3->unp_peercred));
> - unp3->unp_peercred.cr_uid = td->td_proc->p_ucred->cr_uid;
> - unp3->unp_peercred.cr_ngroups = td->td_proc->p_ucred->cr_ngroup
> s;
> - memcpy(unp3->unp_peercred.cr_groups, td->td_proc->p_ucred->cr_g
> roups,
> - sizeof(unp3->unp_peercred.cr_groups));
> + cru2x(td->td_proc->p_ucred, &unp3->unp_peercred);
> unp3->unp_flags |= UNP_HAVEPC;
> /*
> * The receiver's (server's) credentials are copied
> @@ -1396,11 +1392,7 @@
> struct proc *p;
> {
>
> - bzero(&unp->unp_peercred, sizeof(unp->unp_peercred));
> - unp->unp_peercred.cr_uid = p->p_ucred->cr_uid;
> - unp->unp_peercred.cr_ngroups = p->p_ucred->cr_ngroups;
> - bcopy(p->p_ucred->cr_groups, unp->unp_peercred.cr_groups,
> - sizeof(unp->unp_peercred.cr_groups));
> + cru2x(p->p_ucred, &unp->unp_peercred);
> unp->unp_flags |= UNP_HAVEPCCACHED;
> return (0);
> }
> Index: sys/kern/vfs_export.c
> ===================================================================
> RCS file: /ref/cvsf/src/sys/kern/vfs_export.c,v
> retrieving revision 1.312
> diff -u -r1.312 vfs_export.c
> --- sys/kern/vfs_export.c 2001/09/10 11:28:05 1.312
> +++ sys/kern/vfs_export.c 2001/12/14 03:40:24
> @@ -98,11 +98,9 @@
> return (EPERM);
> np = &nep->ne_defexported;
> np->netc_exflags = argp->ex_flags;
> - bzero(&np->netc_anon, sizeof(np->netc_anon));
> - np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
> - np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
> - bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
> - sizeof(np->netc_anon.cr_groups));
> + error = crx2u(&argp->ex_anon, &np->netc_anon);
> + if (error != 0)
> + return (error);
> np->netc_anon.cr_ref = 1;
> mp->mnt_flag |= MNT_DEFEXPORTED;
> return (0);
> @@ -150,11 +148,9 @@
> goto out;
> }
> np->netc_exflags = argp->ex_flags;
> - bzero(&np->netc_anon, sizeof(np->netc_anon));
> - np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
> - np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
> - bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
> - sizeof(np->netc_anon.cr_groups));
> + error = crx2u(&argp->ex_anon, &np->netc_anon);
> + if (error != 0)
> + goto out;
> np->netc_anon.cr_ref = 1;
> return (0);
> out:
> Index: sys/netinet/tcp_subr.c
> ===================================================================
> RCS file: /ref/cvsf/src/sys/netinet/tcp_subr.c,v
> retrieving revision 1.118
> diff -u -r1.118 tcp_subr.c
> --- sys/netinet/tcp_subr.c 2001/11/22 04:50:43 1.118
> +++ sys/netinet/tcp_subr.c 2001/12/14 03:34:19
> @@ -919,11 +919,7 @@
> error = cr_cansee(req->td->td_proc->p_ucred, inp->inp_socket->so_cred);
> if (error)
> goto out;
> - bzero(&xuc, sizeof(xuc));
> - xuc.cr_uid = inp->inp_socket->so_cred->cr_uid;
> - xuc.cr_ngroups = inp->inp_socket->so_cred->cr_ngroups;
> - bcopy(inp->inp_socket->so_cred->cr_groups, xuc.cr_groups,
> - sizeof(xuc.cr_groups));
> + cru2x(inp->inp_socket->so_cred, &xuc);
> error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
> out:
> splx(s);
> @@ -975,11 +971,7 @@
> error = cr_cansee(req->td->td_proc->p_ucred, inp->inp_socket->so_cred);
> if (error)
> goto out;
> - bzero(&xuc, sizeof(xuc));
> - xuc.cr_uid = inp->inp_socket->so_cred->cr_uid;
> - xuc.cr_ngroups = inp->inp_socket->so_cred->cr_ngroups;
> - bcopy(inp->inp_socket->so_cred->cr_groups, xuc.cr_groups,
> - sizeof(xuc.cr_groups));
> + cru2x(inp->inp_socket->so_cred, &xuc);
> error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
> out:
> splx(s);
> Index: sys/netinet/udp_usrreq.c
> ===================================================================
> RCS file: /ref/cvsf/src/sys/netinet/udp_usrreq.c,v
> retrieving revision 1.100
> diff -u -r1.100 udp_usrreq.c
> --- sys/netinet/udp_usrreq.c 2001/11/08 02:13:17 1.100
> +++ sys/netinet/udp_usrreq.c 2001/12/14 03:34:36
> @@ -651,11 +651,7 @@
> error = cr_cansee(req->td->td_proc->p_ucred, inp->inp_socket->so_cred);
> if (error)
> goto out;
> - bzero(&xuc, sizeof(xuc));
> - xuc.cr_uid = inp->inp_socket->so_cred->cr_uid;
> - xuc.cr_ngroups = inp->inp_socket->so_cred->cr_ngroups;
> - bcopy(inp->inp_socket->so_cred->cr_groups, xuc.cr_groups,
> - sizeof(xuc.cr_groups));
> + cru2x(inp->inp_socket->so_cred, &xuc);
> error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
> out:
> splx(s);
> Index: sys/netinet6/udp6_usrreq.c
> ===================================================================
> RCS file: /ref/cvsf/src/sys/netinet6/udp6_usrreq.c,v
> retrieving revision 1.19
> diff -u -r1.19 udp6_usrreq.c
> --- sys/netinet6/udp6_usrreq.c 2001/11/08 02:13:18 1.19
> +++ sys/netinet6/udp6_usrreq.c 2001/12/14 03:35:00
> @@ -484,11 +484,7 @@
> error = ENOENT;
> goto out;
> }
> - bzero(&xuc, sizeof(xuc));
> - xuc.cr_uid = inp->inp_socket->so_cred->cr_uid;
> - xuc.cr_ngroups = inp->inp_socket->so_cred->cr_ngroups;
> - bcopy(inp->inp_socket->so_cred->cr_groups, xuc.cr_groups,
> - sizeof(xuc.cr_groups));
> + cru2x(inp->inp_socket->so_cred, &xuc);
> error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
> out:
> splx(s);
> Index: sys/security/lomac/kernel_socket.c
> ===================================================================
> RCS file: /ref/cvsf/src/sys/security/lomac/kernel_socket.c,v
> retrieving revision 1.2
> diff -u -r1.2 kernel_socket.c
> --- sys/security/lomac/kernel_socket.c 2001/12/03 00:21:18 1.2
> +++ sys/security/lomac/kernel_socket.c 2001/12/14 03:35:23
> @@ -265,11 +265,7 @@
> * from its process structure at the time of connect()
> * (which is now).
> */
> - memset(&unp3->unp_peercred, '\0', sizeof(unp3->unp_peercred));
> - unp3->unp_peercred.cr_uid = td->td_proc->p_ucred->cr_uid;
> - unp3->unp_peercred.cr_ngroups = td->td_proc->p_ucred->cr_ngroup
> s;
> - memcpy(unp3->unp_peercred.cr_groups, td->td_proc->p_ucred->cr_g
> roups,
> - sizeof(unp3->unp_peercred.cr_groups));
> + cru2x(td->td_proc->p_ucred, &unp3->unp_peercred);
> unp3->unp_flags |= UNP_HAVEPC;
> /*
> * The receiver's (server's) credentials are copied
> Index: sys/sys/ucred.h
> ===================================================================
> RCS file: /ref/cvsf/src/sys/sys/ucred.h,v
> retrieving revision 1.26
> diff -u -r1.26 ucred.h
> --- sys/sys/ucred.h 2001/10/11 23:38:17 1.26
> +++ sys/sys/ucred.h 2001/12/14 03:30:26
> @@ -73,12 +73,13 @@
> * any need to change the size of this or layout of its used fields.
> */
> struct xucred {
> - u_short _cr_unused0; /* compatibility with old ucred */
> + u_short cr_version; /* structure layout version */
> uid_t cr_uid; /* effective user id */
> short cr_ngroups; /* number of groups */
> gid_t cr_groups[NGROUPS]; /* groups */
> void *_cr_unused1; /* compatibility with old ucred */
> };
> +#define XUCRED_VERSION 0
>
> #ifdef _KERNEL
>
> @@ -95,6 +96,8 @@
> struct ucred *crget __P((void));
> struct ucred *crhold __P((struct ucred *cr));
> int crshared __P((struct ucred *cr));
> +void cru2x __P((struct ucred *cr, struct xucred *xcr));
> +int crx2u __P((struct xucred *xcr, struct ucred *cr));
> int groupmember __P((gid_t gid, struct ucred *cred));
> #endif /* _KERNEL */
>
> Index: usr.sbin/inetd/builtins.c
> ===================================================================
> RCS file: /ref/cvsf/src/usr.sbin/inetd/builtins.c,v
> retrieving revision 1.36
> diff -u -r1.36 builtins.c
> --- usr.sbin/inetd/builtins.c 2001/07/17 07:12:57 1.36
> +++ usr.sbin/inetd/builtins.c 2001/12/14 01:20:18
> @@ -569,7 +569,7 @@
> getcredfail = EAFNOSUPPORT;
> break;
> }
> - if (getcredfail != 0) {
> + if (getcredfail != 0 || uc.cr_version != XUCRED_VERSION) {
> if (*idbuf == '\0')
> iderror(lport, fport, s,
> getcredfail == ENOENT ? ID_NOUSER : ID_UNKNOWN);
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20011219005412.54A833E2F>