Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 5 Sep 2025 13:33:22 +0000 (UTC)
From:      "Bjoern A. Zeeb" <bz@FreeBSD.org>
To:        Jamie Gritton <jamie@FreeBSD.org>
Cc:        src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org,  dev-commits-src-main@FreeBSD.org
Subject:   Re: git: 851dc7f859c2 - main - jail: add jail descriptors
Message-ID:  <7nnn754n-7r54-79rp-438n-12nsp9non865@SerrOFQ.bet>
In-Reply-To: <202509042031.584KVpxY000408@gitrepo.freebsd.org>
References:  <202509042031.584KVpxY000408@gitrepo.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 4 Sep 2025, Jamie Gritton wrote:

> The branch main has been updated by jamie:
>
> URL: https://cgit.FreeBSD.org/src/commit/?id=851dc7f859c23cab09a348bca03ab655534fb7e0
>
> commit 851dc7f859c23cab09a348bca03ab655534fb7e0
> Author:     Jamie Gritton <jamie@FreeBSD.org>
> AuthorDate: 2025-09-04 20:27:47 +0000
> Commit:     Jamie Gritton <jamie@FreeBSD.org>
> CommitDate: 2025-09-04 20:27:47 +0000
>
>    jail: add jail descriptors
>
>    Similar to process descriptors, jail desriptors are allow jail
>    administration using the file descriptor interface instead of JIDs.
>    They come from and can be used by jail_set(2) and jail_get(2),
>    and there are two new system calls, jail_attach_jd(2) and
>    jail_remove_jd(2).
>
>    Reviewed by:    bz, brooks

Just for the records, I looked at this more than a year ago but I have
not done any (final) review.

Still happy that this landed.

>    Relnotes:       yes
>    Differential Revision:  https://reviews.freebsd.org/D43696
> ---
> lib/libjail/jail.c                             |  64 +++-
> lib/libsys/Symbol.sys.map                      |   2 +
> lib/libsys/_libsys.h                           |   4 +
> lib/libsys/jail.2                              | 267 ++++++++++++++++-
> lib/libsys/syscalls.map                        |   4 +
> sys/compat/freebsd32/freebsd32_syscall.h       |   4 +-
> sys/compat/freebsd32/freebsd32_syscalls.c      |   2 +
> sys/compat/freebsd32/freebsd32_sysent.c        |   2 +
> sys/compat/freebsd32/freebsd32_systrace_args.c |  44 +++
> sys/conf/files                                 |   1 +
> sys/kern/init_sysent.c                         |   2 +
> sys/kern/kern_descrip.c                        |   2 +
> sys/kern/kern_jail.c                           | 396 +++++++++++++++++++++++--
> sys/kern/kern_jaildesc.c                       | 337 +++++++++++++++++++++
> sys/kern/syscalls.c                            |   2 +
> sys/kern/syscalls.master                       |  10 +
> sys/kern/systrace_args.c                       |  44 +++
> sys/sys/file.h                                 |   1 +
> sys/sys/jail.h                                 |  15 +-
> sys/sys/jaildesc.h                             |  85 ++++++
> sys/sys/syscall.h                              |   4 +-
> sys/sys/syscall.mk                             |   4 +-
> sys/sys/sysproto.h                             |  10 +
> sys/sys/user.h                                 |   4 +
> 24 files changed, 1256 insertions(+), 54 deletions(-)
>
> diff --git a/lib/libjail/jail.c b/lib/libjail/jail.c
> index 30282e67866c..931391055919 100644
> --- a/lib/libjail/jail.c
> +++ b/lib/libjail/jail.c
> @@ -75,8 +75,9 @@ int
> jail_setv(int flags, ...)
> {
> 	va_list ap, tap;
> -	struct jailparam *jp;
> -	const char *name, *value;
> +	struct jailparam *jp, *jp_desc;
> +	const char *name;
> +	char *value, *desc_value;
> 	int njp, jid;
>
> 	/* Create the parameter list and import the parameters. */
> @@ -86,15 +87,24 @@ jail_setv(int flags, ...)
> 		(void)va_arg(tap, char *);
> 	va_end(tap);
> 	jp = alloca(njp * sizeof(struct jailparam));
> -	for (njp = 0; (name = va_arg(ap, char *)) != NULL;) {
> +	jp_desc = NULL;
> +	desc_value = NULL;
> +	for (njp = 0; (name = va_arg(ap, char *)) != NULL; njp++) {
> 		value = va_arg(ap, char *);
> 		if (jailparam_init(jp + njp, name) < 0)
> 			goto error;
> -		if (jailparam_import(jp + njp++, value) < 0)
> +		if (jailparam_import(jp + njp, value) < 0)
> 			goto error;
> +		if (!strcmp(name, "desc")
> +		    && (flags & (JAIL_GET_DESC | JAIL_OWN_DESC))) {
> +			jp_desc = jp + njp;
> +			desc_value = value;
> +		}
> 	}
> 	va_end(ap);
> 	jid = jailparam_set(jp, njp, flags);
> +	if (jid > 0 && jp_desc != NULL)
> +		sprintf(desc_value, "%d", *(int *)jp_desc->jp_value);
> 	jailparam_free(jp, njp);
> 	return (jid);
>
> @@ -112,9 +122,10 @@ int
> jail_getv(int flags, ...)
> {
> 	va_list ap, tap;
> -	struct jailparam *jp, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
> +	struct jailparam *jp, *jp_desc, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
> 	char *valarg, *value;
> -	const char *name, *key_value, *lastjid_value, *jid_value, *name_value;
> +	const char *name, *key_value, *desc_value, *lastjid_value, *jid_value;
> +	const char *name_value;
> 	int njp, i, jid;
>
> 	/* Create the parameter list and find the key. */
> @@ -126,15 +137,19 @@ jail_getv(int flags, ...)
>
> 	jp = alloca(njp * sizeof(struct jailparam));
> 	va_copy(tap, ap);
> -	jp_lastjid = jp_jid = jp_name = NULL;
> -	lastjid_value = jid_value = name_value = NULL;
> +	jp_desc = jp_lastjid = jp_jid = jp_name = NULL;
> +	desc_value = lastjid_value = jid_value = name_value = NULL;
> 	for (njp = 0; (name = va_arg(tap, char *)) != NULL; njp++) {
> 		value = va_arg(tap, char *);
> 		if (jailparam_init(jp + njp, name) < 0) {
> 			va_end(tap);
> 			goto error;
> 		}
> -		if (!strcmp(jp[njp].jp_name, "lastjid")) {
> +		if (!strcmp(jp[njp].jp_name, "desc")
> +		    && (flags & (JAIL_USE_DESC | JAIL_AT_DESC))) {
> +			jp_desc = jp + njp;
> +			desc_value = value;
> +		} else if (!strcmp(jp[njp].jp_name, "lastjid")) {
> 			jp_lastjid = jp + njp;
> 			lastjid_value = value;
> 		} else if (!strcmp(jp[njp].jp_name, "jid")) {
> @@ -147,7 +162,10 @@ jail_getv(int flags, ...)
> 	}
> 	va_end(tap);
> 	/* Import the key parameter. */
> -	if (jp_lastjid != NULL) {
> +	if (jp_desc != NULL && (flags & JAIL_USE_DESC)) {
> +		jp_key = jp_desc;
> +		key_value = desc_value;
> +	} else if (jp_lastjid != NULL) {
> 		jp_key = jp_lastjid;
> 		key_value = lastjid_value;
> 	} else if (jp_jid != NULL && strtol(jid_value, NULL, 10) != 0) {
> @@ -163,6 +181,9 @@ jail_getv(int flags, ...)
> 	}
> 	if (jailparam_import(jp_key, key_value) < 0)
> 		goto error;
> +	if (jp_desc != NULL && jp_desc != jp_key
> +	    && jailparam_import(jp_desc, desc_value) < 0)
> +		goto error;
> 	/* Get the jail and export the parameters. */
> 	jid = jailparam_get(jp, njp, flags);
> 	if (jid < 0)
> @@ -571,7 +592,7 @@ int
> jailparam_get(struct jailparam *jp, unsigned njp, int flags)
> {
> 	struct iovec *jiov;
> -	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
> +	struct jailparam *jp_desc, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
> 	int i, ai, ki, jid, arrays, sanity;
> 	unsigned j;
>
> @@ -580,10 +601,13 @@ jailparam_get(struct jailparam *jp, unsigned njp, int flags)
> 	 * Find the key and any array parameters.
> 	 */
> 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
> -	jp_lastjid = jp_jid = jp_name = NULL;
> +	jp_desc = jp_lastjid = jp_jid = jp_name = NULL;
> 	arrays = 0;
> 	for (ai = j = 0; j < njp; j++) {
> -		if (!strcmp(jp[j].jp_name, "lastjid"))
> +		if (!strcmp(jp[j].jp_name, "desc")
> +		    && (flags & (JAIL_USE_DESC | JAIL_AT_DESC)))
> +			jp_desc = jp + j;
> +		else if (!strcmp(jp[j].jp_name, "lastjid"))
> 			jp_lastjid = jp + j;
> 		else if (!strcmp(jp[j].jp_name, "jid"))
> 			jp_jid = jp + j;
> @@ -599,7 +623,9 @@ jailparam_get(struct jailparam *jp, unsigned njp, int flags)
> 			ai++;
> 		}
> 	}
> -	jp_key = jp_lastjid ? jp_lastjid :
> +	jp_key = jp_desc && jp_desc->jp_valuelen == sizeof(int) &&
> +	    jp_desc->jp_value && (flags & JAIL_USE_DESC) ? jp_desc :
> +	    jp_lastjid ? jp_lastjid :
> 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
> 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
> 	if (jp_key == NULL || jp_key->jp_value == NULL) {
> @@ -622,6 +648,14 @@ jailparam_get(struct jailparam *jp, unsigned njp, int flags)
> 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
> 	ki++;
> 	jail_errmsg[0] = 0;
> +	if (jp_desc != NULL && jp_desc != jp_key) {
> +		jiov[ki].iov_base = jp_desc->jp_name;
> +		jiov[ki].iov_len = strlen(jp_desc->jp_name) + 1;
> +		ki++;
> +		jiov[ki].iov_base = jp_desc->jp_value;
> +		jiov[ki].iov_len = jp_desc->jp_valuelen;
> +		ki++;
> +	}
> 	if (arrays && jail_get(jiov, ki, flags) < 0) {
> 		if (!jail_errmsg[0])
> 			snprintf(jail_errmsg, sizeof(jail_errmsg),
> @@ -649,7 +683,7 @@ jailparam_get(struct jailparam *jp, unsigned njp, int flags)
> 			jiov[ai].iov_base = jp[j].jp_value;
> 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
> 			ai++;
> -		} else if (jp + j != jp_key) {
> +		} else if (jp + j != jp_key && jp + j != jp_desc) {
> 			jiov[i].iov_base = jp[j].jp_name;
> 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
> 			i++;
> diff --git a/lib/libsys/Symbol.sys.map b/lib/libsys/Symbol.sys.map
> index 1a297f9df581..e3fd8ac10621 100644
> --- a/lib/libsys/Symbol.sys.map
> +++ b/lib/libsys/Symbol.sys.map
> @@ -382,6 +382,8 @@ FBSD_1.8 {
> 	getrlimitusage;
> 	inotify_add_watch_at;
> 	inotify_rm_watch;
> +	jail_attach_jd;
> +	jail_remove_jd;
> 	kcmp;
> 	setcred;
> 	setgroups;
> diff --git a/lib/libsys/_libsys.h b/lib/libsys/_libsys.h
> index 34eebc1aa67a..6bd768708a78 100644
> --- a/lib/libsys/_libsys.h
> +++ b/lib/libsys/_libsys.h
> @@ -468,6 +468,8 @@ typedef int (__sys_inotify_add_watch_at_t)(int, int, const char *, uint32_t);
> typedef int (__sys_inotify_rm_watch_t)(int, int);
> typedef int (__sys_getgroups_t)(int, gid_t *);
> typedef int (__sys_setgroups_t)(int, const gid_t *);
> +typedef int (__sys_jail_attach_jd_t)(int);
> +typedef int (__sys_jail_remove_jd_t)(int);
>
> _Noreturn void __sys__exit(int rval);
> int __sys_fork(void);
> @@ -872,6 +874,8 @@ int __sys_inotify_add_watch_at(int fd, int dfd, const char * path, uint32_t mask
> int __sys_inotify_rm_watch(int fd, int wd);
> int __sys_getgroups(int gidsetsize, gid_t * gidset);
> int __sys_setgroups(int gidsetsize, const gid_t * gidset);
> +int __sys_jail_attach_jd(int fd);
> +int __sys_jail_remove_jd(int fd);
> __END_DECLS
>
> #endif /* __LIBSYS_H_ */
> diff --git a/lib/libsys/jail.2 b/lib/libsys/jail.2
> index 8f8b9925c712..a0f47cc61cb3 100644
> --- a/lib/libsys/jail.2
> +++ b/lib/libsys/jail.2
> @@ -23,7 +23,7 @@
> .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> .\" SUCH DAMAGE.
> .\"
> -.Dd November 29, 2023
> +.Dd September 4, 2025
> .Dt JAIL 2
> .Os
> .Sh NAME
> @@ -31,7 +31,9 @@
> .Nm jail_get ,
> .Nm jail_set ,
> .Nm jail_remove ,
> -.Nm jail_attach
> +.Nm jail_attach ,
> +.Nm jail_remove_jd ,
> +.Nm jail_attach_jd
> .Nd create and manage system jails
> .Sh LIBRARY
> .Lb libc
> @@ -44,6 +46,10 @@
> .Fn jail_attach "int jid"
> .Ft int
> .Fn jail_remove "int jid"
> +.Ft int
> +.Fn jail_attach_jd "int fd"
> +.Ft int
> +.Fn jail_remove_jd "int fd"
> .In sys/uio.h
> .Ft int
> .Fn jail_get "struct iovec *iov" "u_int niov" "int flags"
> @@ -188,6 +194,29 @@ system call.
> This is deprecated in
> .Fn jail_set
> and has no effect.
> +.It Dv JAIL_USE_DESC
> +Identify the jail by a descriptor in the
> +.Va desc
> +parameter.
> +.It Dv JAIL_AT_DESC
> +Operate in the context of the jail described by the
> +.Va desc
> +parameter, instead of the current jail.
> +Only one of
> +.Dv JAIL_USE_DESC
> +or
> +.Dv JAIL_AT_DESC
> +may be specified.
> +.It Dv JAIL_GET_DESC
> +Return a new jail descriptor for the jail in the
> +.Va desc
> +parameter.
> +.It Dv JAIL_OWN_DESC
> +Return an
> +.Dq owning
> +jail descriptor in the
> +.Va desc
> +parameter.
> .El
> .Pp
> The
> @@ -221,6 +250,9 @@ arguments consists of one or more following flags:
> .Bl -tag -width indent
> .It Dv JAIL_DYING
> Allow getting a jail that is in the process of being removed.
> +.It Dv JAIL_USE_DESC , Dv JAIL_AT_DESC , Dv JAIL_GET_DESC , Dv JAIL_OWN_DESC
> +These have the same meaning as they do in
> +.Fn jail_set .
> .El
> .Pp
> The
> @@ -238,6 +270,101 @@ system call removes the jail identified by
> .Fa jid .
> It will kill all processes belonging to the jail, and remove any children
> of that jail.
> +.Pp
> +The
> +.Fn jail_attach_fd
> +and
> +.Fn jail_remove_fd
> +system calls work the same as
> +.Fn jail_attach
> +and
> +.Fn jail_remove ,
> +except that they operate on the jail identified by jail descriptor
> +.Fa fd .
> +.Ss Jail Descriptors
> +In addition to the jail ID,
> +jails can be referred to using a jail descriptor,
> +a type of file descriptor tied to a particular jail.
> +Jail descriptors are created by calling
> +.Fn jail_set
> +or
> +.Fn jail_get
> +with the special parameter
> +.Va desc ,
> +and either the
> +.Dv JAIL_GET_DESC
> +or
> +.Dv JAIL_OWN_DESC
> +flags set.
> +The difference between the two flags is that descriptors created with
> +.Dv JAIL_OWN_DESC
> +.Po
> +called
> +.Dq owning
> +descriptors
> +.Pc
> +will automatically remove the jail when the descriptor is closed.
> +.Pp
> +Jail descriptors can be passed back to
> +.Fn jail_set
> +or
> +.Fm jail_get
> +with the
> +.Va desc
> +parameter,
> +and either the
> +.Dv JAIL_USE_DESC
> +or
> +.Dv JAIL_AT_DESC
> +flags set.
> +With
> +.Dv JAIL_USE_DESC ,
> +the descriptor identifies the jail to operate on,
> +instead of the
> +.Va jid
> +or
> +.Va name
> +parameter.
> +With
> +.Dv JAIL_AT_DESC ,
> +the descriptor is used in place of the current jail,
> +allowing accessing or creating jails that are children of the
> +descriptor jail.
> +.Pp
> +The system calls
> +.Fn jail_attach_jd
> +and
> +.Fn jail_aremove_jd
> +work the same as
> +.Fn jail_attach
> +and
> +.Fn jail_remove ,
> +except that they operate on the jail referred to by the passed descriptor.
> +.Pp
> +Jail operations via descriptors can be done by processes that do not
> +normally have permission to see or affect the jail,
> +as long as they are allowed by the file permissions of the jail
> +descriptor itself.
> +These permissions can be changed by the descriptor owner via
> +.Xr fchmod 2
> +and
> +.Xr fchown 2 .
> +.Fn jail_get
> +requires read permission,
> +.Fn jail_set
> +and
> +.Fn jail_remove
> +require write permission,
> +and
> +.Fn jail_attach
> +requires execute permission.
> +Also, use of a descriptor with the
> +.Dv JAIL_AT_DESC
> +flag requires execute permission.
> +An owning descriptor is identified by the
> +.Em sticky bit ,
> +which may also be changed via
> +.Xr fchmod 2 .
> .Sh RETURN VALUES
> If successful,
> .Fn jail ,
> @@ -249,7 +376,7 @@ They return \-1 on failure, and set
> .Va errno
> to indicate the error.
> .Pp
> -.Rv -std jail_attach jail_remove
> +.Rv -std jail_attach jail_remove jail_attach_jd jail_remove_jd
> .Sh ERRORS
> The
> .Fn jail
> @@ -275,12 +402,44 @@ The
> system call
> will fail if:
> .Bl -tag -width Er
> +.It Bq Er EBADF
> +The
> +.Va desc
> +parameter does not refer to a valid jail descriptor,
> +and either the
> +.Dv JAIL_USE_DESC
> +or
> +.Dv JAIL_AT_DESC
> +flag was set.
> +.It Bq Er EACCES
> +Write permission is denied on the jail descriptor in the
> +.Va desc
> +parameter,
> +and the
> +.Dv JAIL_USE_DESC
> +flag was set.
> +.It Bq Er EACCES
> +Execute permission is denied on the jail descriptor in the
> +.Va desc
> +parameter,
> +and either the
> +.Dv JAIL_AT_DESC
> +or
> +.Dv JAIL_ATTACH
> +flag was set.
> .It Bq Er EPERM
> This process is not allowed to create a jail, either because it is not
> the super-user, or because it would exceed the jail's
> .Va children.max
> limit.
> .It Bq Er EPERM
> +The jail descriptor in the
> +.Va desc
> +parameter was created by a user other than the super-user,
> +and the
> +.Dv JAIL_USE_DESC
> +flag was set.
> +.It Bq Er EPERM
> A jail parameter was set to a less restrictive value then the current
> environment.
> .It Bq Er EFAULT
> @@ -298,8 +457,12 @@ flag is not set.
> .It Bq Er ENOENT
> The jail referred to by a
> .Va jid
> -is not accessible by the process, because the process is in a different
> -jail.
> +parameter is not accessible by the process, because the process is in a
> +different jail.
> +.It Bq Er ENOENT
> +The jail referred to by a
> +.Va desc
> +parameter has been removed.
> .It Bq Er EEXIST
> The jail referred to by a
> .Va jid
> @@ -326,6 +489,24 @@ flags is not set.
> A supplied string parameter is longer than allowed.
> .It Bq Er EAGAIN
> There are no jail IDs left.
> +.It Bq Er EMFILE
> +A jail descriptor could not be created for the
> +.Va desc
> +parameter with either the
> +.Dv JAIL_GET_DESC
> +or
> +.Dv JAIL_OWN_DESC
> +flag set,
> +because the process has already reached its limit for open file descriptors.
> +.It Bq Er ENFILE
> +A jail descriptor could not be created for the
> +.Va desc
> +parameter with either the
> +.Dv JAIL_GET_DESC
> +or
> +.Dv JAIL_OWN_DESC
> +flag set,
> +because the system file table is full.
> .El
> .Pp
> The
> @@ -333,6 +514,29 @@ The
> system call
> will fail if:
> .Bl -tag -width Er
> +.It Bq Er EBADF
> +The
> +.Va desc
> +parameter does not refer to a valid jail descriptor,
> +and either the
> +.Dv JAIL_USE_DESC
> +or
> +.Dv JAIL_AT_DESC
> +flag was set.
> +.It Bq Er EACCES
> +Read permission is denied on the jail descriptor in the
> +.Va desc
> +parameter,
> +and the
> +.Dv JAIL_USE_DESC
> +flag was set.
> +.It Bq Er EACCES
> +Execute permission is denied on the jail descriptor in the
> +.Va desc
> +parameter,
> +and the
> +.Dv JAIL_AT_DESC
> +flag was set.
> .It Bq Er EFAULT
> .Fa Iov ,
> or one of the addresses contained within it,
> @@ -352,10 +556,33 @@ jail.
> The
> .Va lastjid
> parameter is greater than the highest current jail ID.
> +.It Bq Er ENOENT
> +The jail referred to by a
> +.Va desc
> +parameter has been removed
> +.Pq even if the Dv JAIL_CREATE flag has been set .
> .It Bq Er EINVAL
> A supplied parameter is the wrong size.
> .It Bq Er EINVAL
> A supplied parameter name does not match any known parameters.
> +.It Bq Er EMFILE
> +A jail descriptor could not be created for the
> +.Va desc
> +parameter with either the
> +.Dv JAIL_GET_DESC
> +or
> +.Dv JAIL_OWN_DESC
> +flag set,
> +because the process has already reached its limit for open file descriptors.
> +.It Bq Er ENFILE
> +A jail descriptor could not be created for the
> +.Va desc
> +parameter with either the
> +.Dv JAIL_GET_DESC
> +or
> +.Dv JAIL_OWN_DESC
> +flag set,
> +because the system file table is full.
> .El
> .Pp
> The
> @@ -373,11 +600,39 @@ The jail specified by
> does not exist.
> .El
> .Pp
> +The
> +.Fn jail_attach_jd
> +and
> +.Fn jail_remove_jd
> +system calls
> +will fail if:
> +.Bl -tag -width Er
> +.It Bq Er EBADF
> +The
> +.Fa fd
> +argument is not a valid jail descriptor.
> +.It Bq Er EACCES
> +Permission is denied on the jail descriptor
> +.Po
> +execute permission for
> +.Fn jail_attach_fd ,
> +or write permission for
> +.Fn jail_remove_fd
> +.Pc .
> +.It Bq Er EPERM
> +The jail descriptor was created by a user other than the super-user.
> +.It Bq Er EINVAL
> +The jail specified by
> +.Fa jid
> +has been removed.
> +.El
> +.Pp
> Further
> .Fn jail ,
> .Fn jail_set ,
> +.Fn jail_attach ,
> and
> -.Fn jail_attach
> +.Fn jail_attach_jd
> call
> .Xr chroot 2
> internally, so they can fail for all the same reasons.
> diff --git a/lib/libsys/syscalls.map b/lib/libsys/syscalls.map
> index 4cf80a2ffc69..b5400b9849b3 100644
> --- a/lib/libsys/syscalls.map
> +++ b/lib/libsys/syscalls.map
> @@ -813,4 +813,8 @@ FBSDprivate_1.0 {
> 	__sys_getgroups;
> 	_setgroups;
> 	__sys_setgroups;
> +	_jail_attach_jd;
> +	__sys_jail_attach_jd;
> +	_jail_remove_jd;
> +	__sys_jail_remove_jd;
> };
> diff --git a/sys/compat/freebsd32/freebsd32_syscall.h b/sys/compat/freebsd32/freebsd32_syscall.h
> index 90cd21a80923..54063150eef9 100644
> --- a/sys/compat/freebsd32/freebsd32_syscall.h
> +++ b/sys/compat/freebsd32/freebsd32_syscall.h
> @@ -515,4 +515,6 @@
> #define	FREEBSD32_SYS_inotify_rm_watch	594
> #define	FREEBSD32_SYS_getgroups	595
> #define	FREEBSD32_SYS_setgroups	596
> -#define	FREEBSD32_SYS_MAXSYSCALL	597
> +#define	FREEBSD32_SYS_jail_attach_jd	597
> +#define	FREEBSD32_SYS_jail_remove_jd	598
> +#define	FREEBSD32_SYS_MAXSYSCALL	599
> diff --git a/sys/compat/freebsd32/freebsd32_syscalls.c b/sys/compat/freebsd32/freebsd32_syscalls.c
> index f0f8d26554b5..f7cc4c284e4d 100644
> --- a/sys/compat/freebsd32/freebsd32_syscalls.c
> +++ b/sys/compat/freebsd32/freebsd32_syscalls.c
> @@ -602,4 +602,6 @@ const char *freebsd32_syscallnames[] = {
> 	"inotify_rm_watch",			/* 594 = inotify_rm_watch */
> 	"getgroups",			/* 595 = getgroups */
> 	"setgroups",			/* 596 = setgroups */
> +	"jail_attach_jd",			/* 597 = jail_attach_jd */
> +	"jail_remove_jd",			/* 598 = jail_remove_jd */
> };
> diff --git a/sys/compat/freebsd32/freebsd32_sysent.c b/sys/compat/freebsd32/freebsd32_sysent.c
> index 12f1a346c3e9..18f809ef04e3 100644
> --- a/sys/compat/freebsd32/freebsd32_sysent.c
> +++ b/sys/compat/freebsd32/freebsd32_sysent.c
> @@ -664,4 +664,6 @@ struct sysent freebsd32_sysent[] = {
> 	{ .sy_narg = AS(inotify_rm_watch_args), .sy_call = (sy_call_t *)sys_inotify_rm_watch, .sy_auevent = AUE_INOTIFY, .sy_flags = SYF_CAPENABLED, .sy_thrcnt = SY_THR_STATIC },	/* 594 = inotify_rm_watch */
> 	{ .sy_narg = AS(getgroups_args), .sy_call = (sy_call_t *)sys_getgroups, .sy_auevent = AUE_GETGROUPS, .sy_flags = SYF_CAPENABLED, .sy_thrcnt = SY_THR_STATIC },	/* 595 = getgroups */
> 	{ .sy_narg = AS(setgroups_args), .sy_call = (sy_call_t *)sys_setgroups, .sy_auevent = AUE_SETGROUPS, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 596 = setgroups */
> +	{ .sy_narg = AS(jail_attach_jd_args), .sy_call = (sy_call_t *)sys_jail_attach_jd, .sy_auevent = AUE_JAIL_ATTACH, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 597 = jail_attach_jd */
> +	{ .sy_narg = AS(jail_remove_jd_args), .sy_call = (sy_call_t *)sys_jail_remove_jd, .sy_auevent = AUE_JAIL_REMOVE, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 598 = jail_remove_jd */
> };
> diff --git a/sys/compat/freebsd32/freebsd32_systrace_args.c b/sys/compat/freebsd32/freebsd32_systrace_args.c
> index e471c5148021..29a5497e9efa 100644
> --- a/sys/compat/freebsd32/freebsd32_systrace_args.c
> +++ b/sys/compat/freebsd32/freebsd32_systrace_args.c
> @@ -3413,6 +3413,20 @@ systrace_args(int sysnum, void *params, uint64_t *uarg, int *n_args)
> 		*n_args = 2;
> 		break;
> 	}
> +	/* jail_attach_jd */
> +	case 597: {
> +		struct jail_attach_jd_args *p = params;
> +		iarg[a++] = p->fd; /* int */
> +		*n_args = 1;
> +		break;
> +	}
> +	/* jail_remove_jd */
> +	case 598: {
> +		struct jail_remove_jd_args *p = params;
> +		iarg[a++] = p->fd; /* int */
> +		*n_args = 1;
> +		break;
> +	}
> 	default:
> 		*n_args = 0;
> 		break;
> @@ -9222,6 +9236,26 @@ systrace_entry_setargdesc(int sysnum, int ndx, char *desc, size_t descsz)
> 			break;
> 		};
> 		break;
> +	/* jail_attach_jd */
> +	case 597:
> +		switch (ndx) {
> +		case 0:
> +			p = "int";
> +			break;
> +		default:
> +			break;
> +		};
> +		break;
> +	/* jail_remove_jd */
> +	case 598:
> +		switch (ndx) {
> +		case 0:
> +			p = "int";
> +			break;
> +		default:
> +			break;
> +		};
> +		break;
> 	default:
> 		break;
> 	};
> @@ -11130,6 +11164,16 @@ systrace_return_setargdesc(int sysnum, int ndx, char *desc, size_t descsz)
> 		if (ndx == 0 || ndx == 1)
> 			p = "int";
> 		break;
> +	/* jail_attach_jd */
> +	case 597:
> +		if (ndx == 0 || ndx == 1)
> +			p = "int";
> +		break;
> +	/* jail_remove_jd */
> +	case 598:
> +		if (ndx == 0 || ndx == 1)
> +			p = "int";
> +		break;
> 	default:
> 		break;
> 	};
> diff --git a/sys/conf/files b/sys/conf/files
> index d89813c70355..9661bafea8f9 100644
> --- a/sys/conf/files
> +++ b/sys/conf/files
> @@ -3808,6 +3808,7 @@ kern/kern_hhook.c		standard
> kern/kern_idle.c		standard
> kern/kern_intr.c		standard
> kern/kern_jail.c		standard
> +kern/kern_jaildesc.c		standard
> kern/kern_jailmeta.c		standard
> kern/kern_kcov.c		optional kcov			\
> 	compile-with "${NOSAN_C} ${MSAN_CFLAGS}"
> diff --git a/sys/kern/init_sysent.c b/sys/kern/init_sysent.c
> index fcd232cde21e..e42e7dcf8b44 100644
> --- a/sys/kern/init_sysent.c
> +++ b/sys/kern/init_sysent.c
> @@ -663,4 +663,6 @@ struct sysent sysent[] = {
> 	{ .sy_narg = AS(inotify_rm_watch_args), .sy_call = (sy_call_t *)sys_inotify_rm_watch, .sy_auevent = AUE_INOTIFY, .sy_flags = SYF_CAPENABLED, .sy_thrcnt = SY_THR_STATIC },	/* 594 = inotify_rm_watch */
> 	{ .sy_narg = AS(getgroups_args), .sy_call = (sy_call_t *)sys_getgroups, .sy_auevent = AUE_GETGROUPS, .sy_flags = SYF_CAPENABLED, .sy_thrcnt = SY_THR_STATIC },	/* 595 = getgroups */
> 	{ .sy_narg = AS(setgroups_args), .sy_call = (sy_call_t *)sys_setgroups, .sy_auevent = AUE_SETGROUPS, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 596 = setgroups */
> +	{ .sy_narg = AS(jail_attach_jd_args), .sy_call = (sy_call_t *)sys_jail_attach_jd, .sy_auevent = AUE_JAIL_ATTACH, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 597 = jail_attach_jd */
> +	{ .sy_narg = AS(jail_remove_jd_args), .sy_call = (sy_call_t *)sys_jail_remove_jd, .sy_auevent = AUE_JAIL_REMOVE, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 598 = jail_remove_jd */
> };
> diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
> index a27ab33b34da..057235574eb5 100644
> --- a/sys/kern/kern_descrip.c
> +++ b/sys/kern/kern_descrip.c
> @@ -5250,6 +5250,8 @@ file_type_to_name(short type)
> 		return ("eventfd");
> 	case DTYPE_TIMERFD:
> 		return ("timerfd");
> +	case DTYPE_JAILDESC:
> +		return ("jail");
> 	default:
> 		return ("unkn");
> 	}
> diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
> index 52210553016b..5a1fbe23ddeb 100644
> --- a/sys/kern/kern_jail.c
> +++ b/sys/kern/kern_jail.c
> @@ -39,6 +39,7 @@
> #include <sys/kernel.h>
> #include <sys/systm.h>
> #include <sys/errno.h>
> +#include <sys/file.h>
> #include <sys/sysproto.h>
> #include <sys/malloc.h>
> #include <sys/osd.h>
> @@ -49,6 +50,7 @@
> #include <sys/taskqueue.h>
> #include <sys/fcntl.h>
> #include <sys/jail.h>
> +#include <sys/jaildesc.h>
> #include <sys/linker.h>
> #include <sys/lock.h>
> #include <sys/mman.h>
> @@ -988,6 +990,8 @@ prison_ip_cnt(const struct prison *pr, const pr_family_t af)
> int
> kern_jail_set(struct thread *td, struct uio *optuio, int flags)
> {
> +	struct file *jfp_out;
> +	struct jaildesc *desc_in;
> 	struct nameidata nd;
> #ifdef INET
> 	struct prison_ip *ip4;
> @@ -998,6 +1002,7 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags)
> 	struct vfsopt *opt;
> 	struct vfsoptlist *opts;
> 	struct prison *pr, *deadpr, *dinspr, *inspr, *mypr, *ppr, *tpr;
> +	struct ucred *jdcred;
> 	struct vnode *root;
> 	char *domain, *errmsg, *host, *name, *namelc, *p, *path, *uuid;
> 	char *g_path, *osrelstr;
> @@ -1011,7 +1016,7 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags)
> 	int created, cuflags, descend, drflags, enforce;
> 	int error, errmsg_len, errmsg_pos;
> 	int gotchildmax, gotenforce, gothid, gotrsnum, gotslevel;
> -	int deadid, jid, jsys, len, level;
> +	int deadid, jfd_in, jfd_out, jfd_pos, jid, jsys, len, level;
> 	int childmax, osreldt, rsnum, slevel;
> #ifdef INET
> 	int ip4s;
> @@ -1027,17 +1032,26 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags)
> 	unsigned tallow;
> 	char numbuf[12];
>
> -	error = priv_check(td, PRIV_JAIL_SET);
> -	if (!error && (flags & JAIL_ATTACH))
> -		error = priv_check(td, PRIV_JAIL_ATTACH);
> -	if (error)
> -		return (error);
> 	mypr = td->td_ucred->cr_prison;
> -	if ((flags & JAIL_CREATE) && mypr->pr_childmax == 0)
> +	if (((flags & (JAIL_CREATE | JAIL_AT_DESC)) == JAIL_CREATE)
> +	    && mypr->pr_childmax == 0)
> 		return (EPERM);
> 	if (flags & ~JAIL_SET_MASK)
> 		return (EINVAL);
> +	if ((flags & (JAIL_USE_DESC | JAIL_AT_DESC))
> +	    == (JAIL_USE_DESC | JAIL_AT_DESC))
> +		return (EINVAL);
> +	prison_hold(mypr);
>
> +#ifdef INET
> +	ip4 = NULL;
> +#endif
> +#ifdef INET6
> +	ip6 = NULL;
> +#endif
> +	g_path = NULL;
> +	jfp_out = NULL;
> +	jfd_out = -1;
> 	/*
> 	 * Check all the parameters before committing to anything.  Not all
> 	 * errors can be caught early, but we may as well try.  Also, this
> @@ -1050,14 +1064,7 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags)
> 	 */
> 	error = vfs_buildopts(optuio, &opts);
> 	if (error)
> -		return (error);
> -#ifdef INET
> -	ip4 = NULL;
> -#endif
> -#ifdef INET6
> -	ip6 = NULL;
> -#endif
> -	g_path = NULL;
> +		goto done_free;
>
> 	cuflags = flags & (JAIL_CREATE | JAIL_UPDATE);
> 	if (!cuflags) {
> @@ -1066,6 +1073,72 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags)
> 		goto done_errmsg;
> 	}
>
> +	error = vfs_copyopt(opts, "desc", &jfd_in, sizeof(jfd_in));
> +	if (error == ENOENT) {
> +		if (flags & (JAIL_USE_DESC | JAIL_AT_DESC | JAIL_GET_DESC |
> +		    JAIL_OWN_DESC)) {
> +			vfs_opterror(opts, "missing desc");
> +			goto done_errmsg;
> +		}
> +		jfd_in = -1;
> +	} else if (error != 0)
> +		goto done_free;
> +	else {
> +		if (!(flags & (JAIL_USE_DESC | JAIL_AT_DESC | JAIL_GET_DESC |
> +		    JAIL_OWN_DESC))) {
> +			vfs_opterror(opts, "unexpected desc");
> +			goto done_errmsg;
> +		}
> +		if (flags & JAIL_AT_DESC) {
> +			/*
> +			 * Look up and create jails based on the
> +			 * descriptor's prison.
> +			 */
> +			prison_free(mypr);
> +			error = jaildesc_find(td, jfd_in, &desc_in, &mypr,
> +			    NULL);
> +			if (error != 0) {
> +				vfs_opterror(opts, error == ENOENT
> +				    ? "descriptor to dead jail"
> +				    : "not a jail descriptor");
> +				goto done_errmsg;
> +			}
> +			/*
> +			 * Check file permissions using the current
> +			 * credentials, and operation permissions
> +			 * using the descriptor's credentials.
> +			 */
> +			error = vaccess(VREG, desc_in->jd_mode, desc_in->jd_uid,
> +			    desc_in->jd_gid, VEXEC, td->td_ucred);
> +			JAILDESC_UNLOCK(desc_in);
> +			if (error != 0)
> +				goto done_free;
> +			if ((flags & JAIL_CREATE) && mypr->pr_childmax == 0) {
> +				error = EPERM;
> +				goto done_free;
> +			}
> +		}
> +		if (flags & (JAIL_GET_DESC | JAIL_OWN_DESC)) {
> +			/* Allocate a jail descriptor to return later. */
> +			error = jaildesc_alloc(td, &jfp_out, &jfd_out,
> +				flags & JAIL_OWN_DESC);
> +			if (error)
> +				goto done_free;
> +		}
> +	}
> +
> +	/*
> +	 * Delay the permission check if using a jail descriptor,
> +	 * until we get the descriptor's credentials.
> +	 */
> +	if (!(flags & JAIL_USE_DESC)) {
> +		error = priv_check(td, PRIV_JAIL_SET);
> +		if (error == 0 && (flags & JAIL_ATTACH))
> +			error = priv_check(td, PRIV_JAIL_ATTACH);
> +		if (error)
> +			goto done_free;
> +	}
> +
> 	error = vfs_copyopt(opts, "jid", &jid, sizeof(jid));
> 	if (error == ENOENT)
> 		jid = 0;
> @@ -1441,7 +1514,57 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags)
> 		error = EAGAIN;
> 		goto done_deref;
> 	}
> -	if (jid != 0) {
> +	if (flags & JAIL_USE_DESC) {
> +		/* Get the jail from its descriptor. */
> +		error = jaildesc_find(td, jfd_in, &desc_in, &pr, &jdcred);
> +		if (error) {
> +			vfs_opterror(opts, error == ENOENT
> +			    ? "descriptor to dead jail"
> +			    : "not a jail descriptor");
> +			goto done_deref;
> +		}
> +		drflags |= PD_DEREF;
> +		/*
> +		 * Check file permissions using the current credentials,
> +		 * and operation permissions using the descriptor's
> +		 * credentials.
> +		 */
> +		error = vaccess(VREG, desc_in->jd_mode, desc_in->jd_uid,
> +		    desc_in->jd_gid, VWRITE, td->td_ucred);
> +		if (error == 0 && (flags & JAIL_ATTACH))
> +			error = vaccess(VREG, desc_in->jd_mode, desc_in->jd_uid,
> +			    desc_in->jd_gid, VEXEC, td->td_ucred);
> +		JAILDESC_UNLOCK(desc_in);
> +		if (error == 0)
> +			error = priv_check_cred(jdcred, PRIV_JAIL_SET);
> +		if (error == 0 && (flags & JAIL_ATTACH))
> +			error = priv_check_cred(jdcred, PRIV_JAIL_ATTACH);
> +		crfree(jdcred);
> +		if (error)
> +			goto done_deref;
> +		mtx_lock(&pr->pr_mtx);
> +		drflags |= PD_LOCKED;
> +		if (cuflags == JAIL_CREATE) {
> +			error = EEXIST;
> +			vfs_opterror(opts, "jail %d already exists",
> +			    pr->pr_id);
> +			goto done_deref;
> +		}
> +		if (!prison_isalive(pr)) {
> +			/* While a jid can be resurrected, the prison
> +			 * itself cannot.
> +			 */
> +			error = ENOENT;
> +			vfs_opterror(opts, "jail %d is dying", pr->pr_id);
> *** 1065 LINES SKIPPED ***
>

-- 
Bjoern A. Zeeb                                                     r15:7



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?7nnn754n-7r54-79rp-438n-12nsp9non865>