Please welcome casperd daemon. It (and its services) will be responsible for

giving access to functionality that is not available in capability mode
sandbox. The functionality can be precisely restricted.

Start with the following services:
- system.dns - provides API compatible to:
	- gethostbyname(3),
	- gethostbyname2(3),
	- gethostbyaddr(3),
	- getaddrinfo(3),
	- getnameinfo(3),
- system.grp - provides getgrent(3)-compatible API,
- system.pwd - provides getpwent(3)-compatible API,
- system.random - allows to obtain entropy from /dev/random,
- system.sysctl - provides sysctlbyname(3-compatible API.

Sponsored by:	The FreeBSD Foundation

17 files changed, 2463 insertions, 0 deletions

diff --git a/lib/libcapsicum/Makefile b/lib/libcapsicum/Makefile
new file mode 100644
index 0000000..54d8dfb
--- /dev/null
+++ b/lib/libcapsicum/Makefile
@@ -0,0 +1,46 @@
+# $FreeBSD$
+
+LIB=	capsicum
+
+SHLIB_MAJOR=	0
+
+SRCS=	libcapsicum.c
+SRCS+=	libcapsicum_dns.c
+SRCS+=	libcapsicum_grp.c
+SRCS+=	libcapsicum_pwd.c
+SRCS+=	libcapsicum_random.c
+SRCS+=	libcapsicum_service.c
+SRCS+=	libcapsicum_sysctl.c
+
+INCS=	libcapsicum.h
+INCS+=	libcapsicum_dns.h
+INCS+=	libcapsicum_grp.h
+INCS+=	libcapsicum_pwd.h
+INCS+=	libcapsicum_random.h
+INCS+=	libcapsicum_service.h
+INCS+=	libcapsicum_sysctl.h
+
+DPADD=	${LIBNV}
+LDADD=	-lnv
+
+CFLAGS+=-I${.CURDIR}
+CFLAGS+=-I${.CURDIR}/../libnv
+
+WARNS?=	6
+
+MAN+=	libcapsicum.3
+
+MLINKS+=libcapsicum.3 cap_init.3
+MLINKS+=libcapsicum.3 cap_wrap.3
+MLINKS+=libcapsicum.3 cap_unwrap.3
+MLINKS+=libcapsicum.3 cap_sock.3
+MLINKS+=libcapsicum.3 cap_clone.3
+MLINKS+=libcapsicum.3 cap_close.3
+MLINKS+=libcapsicum.3 cap_limit_get.3
+MLINKS+=libcapsicum.3 cap_limit_set.3
+MLINKS+=libcapsicum.3 cap_send_nvlist.3
+MLINKS+=libcapsicum.3 cap_recv_nvlist.3
+MLINKS+=libcapsicum.3 cap_xfer_nvlist.3
+MLINKS+=libcapsicum.3 cap_service_open.3
+
+.include <bsd.lib.mk>
diff --git a/lib/libcapsicum/libcapsicum.3 b/lib/libcapsicum/libcapsicum.3
new file mode 100644
index 0000000..6204a0e
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum.3
@@ -0,0 +1,288 @@
+.\" Copyright (c) 2013 The FreeBSD Foundation
+.\" All rights reserved.
+.\"
+.\" This documentation was written by Pawel Jakub Dawidek under sponsorship
+.\" from the FreeBSD Foundation.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd October 26, 2013
+.Dt LIBCAPSICUM 3
+.Os
+.Sh NAME
+.Nm cap_init ,
+.Nm cap_wrap ,
+.Nm cap_unwrap ,
+.Nm cap_sock ,
+.Nm cap_clone ,
+.Nm cap_close ,
+.Nm cap_limit_get ,
+.Nm cap_limit_set ,
+.Nm cap_send_nvlist ,
+.Nm cap_recv_nvlist ,
+.Nm cap_xfer_nvlist ,
+.Nm cap_service_open
+.Nd "library for handling application capabilities"
+.Sh LIBRARY
+.Lb libcapsicum
+.Sh SYNOPSIS
+.In libcapsicum.h
+.In nv.h
+.Ft "cap_channel_t *"
+.Fn cap_init "void"
+.Ft "cap_channel_t *"
+.Fn cap_wrap "int sock"
+.Ft "int"
+.Fn cap_unwrap "cap_channel_t *chan"
+.Ft "int"
+.Fn cap_sock "const cap_channel_t *chan"
+.Ft "cap_channel_t *"
+.Fn cap_clone "const cap_channel_t *chan"
+.Ft "void"
+.Fn cap_close "cap_channel_t *chan"
+.Ft "int"
+.Fn cap_limit_get "const cap_channel_t *chan" "nvlist_t **limitsp"
+.Ft "int"
+.Fn cap_limit_set "const cap_channel_t *chan" "nvlist_t *limits"
+.Ft "int"
+.Fn cap_send_nvlist "const cap_channel_t *chan" "const nvlist_t *nvl"
+.Ft "nvlist_t *"
+.Fn cap_recv_nvlist "const cap_channel_t *chan"
+.Ft "nvlist_t *"
+.Fn cap_xfer_nvlist "const cap_channel_t *chan" "nvlist_t *nvl"
+.In libcapsicum_service.h
+.Ft "cap_channel_t *"
+.Fn cap_service_open "const cap_channel_t *chan" "const char *name"
+.Sh DESCRIPTION
+The
+.Nm libcapsicum
+library allows to manage application capabilities through the
+.Xr casperd 8
+daemon.
+.Pp
+The application capability (represented by the
+.Vt cap_channel_t
+type) is a communication channel between the caller and the
+.Xr casperd 8
+daemon or an instance of one of its services.
+A capability to the
+.Xr casperd 8
+daemon obtained with the
+.Fn cap_init
+function allows to create capabilities to casper's services via the
+.Fn cap_service_open
+function.
+.Pp
+The
+.Fn cap_init
+function opens capability to the
+.Xr casperd 8
+daemon.
+.Pp
+The
+.Fn cap_wrap
+function creates
+.Vt cap_channel_t
+based on the given socket.
+The function is used when capability is inherited through
+.Xr execve 2
+or send over
+.Xr unix 4
+domain socket as a regular file descriptor and has to be represented as
+.Vt cap_channel_t
+again.
+.Pp
+The
+.Fn cap_unwrap
+function is the opposite of the
+.Fn cap_wrap
+function.
+It frees the
+.Vt cap_channel_t
+structure and returns
+.Xr unix 4
+domain socket associated with it.
+.Pp
+The
+.Fn cap_clone
+function clones the given capability.
+.Pp
+The
+.Fn cap_close
+function closes the given capability.
+.Pp
+The
+.Fn cap_sock
+function returns
+.Xr unix 4
+domain socket descriptor associated with the given capability for use with
+system calls like
+.Xr kevent 2 ,
+.Xr poll 2
+and
+.Xr select 2 .
+.Pp
+The
+.Fn cap_limit_get
+function stores current limits of the given capability in the
+.Fa limitsp
+argument.
+If the function return
+.Va 0
+and
+.Dv NULL
+is stored in
+.Fa limitsp
+it means there are no limits set.
+.Pp
+The
+.Fn cap_limit_set
+function sets limits for the given capability.
+The limits are provided as nvlist.
+The exact format depends on the service the capability represents.
+.Pp
+The
+.Fn cap_send_nvlist
+function sends the given nvlist over the given capability.
+This is low level interface to communicate with casper services.
+Most services should provide higher level API.
+.Pp
+The
+.Fn cap_recv_nvlist
+function receives the given nvlist over the given capability.
+.Pp
+The
+.Fn cap_xfer_nvlist
+function sends the given nvlist, destroys it and receives new nvlist in
+response over the given capability.
+It does not matter if the function succeeds or fails, the nvlist given
+for sending will always be destroyed once the function returns.
+.Pp
+The
+.Fn cap_service_open
+function opens casper service of the given name through casper capability
+obtained via the
+.Fn cap_init
+function.
+The function returns capability that provides access to opened service.
+.Sh RETURN VALUES
+The
+.Fn cap_clone ,
+.Fn cap_init ,
+.Fn cap_recv_nvlist ,
+.Fn cap_service_open ,
+.Fn cap_wrap
+and
+.Fn cap_xfer_nvlist
+functions return
+.Dv NULL
+and set the
+.Va errno
+variable on failure.
+.Pp
+The
+.Fn cap_limit_get ,
+.Fn cap_limit_set
+and
+.Fn cap_send_nvlist
+functions return
+.Dv -1
+and set the
+.Va errno
+variable on failure.
+.Pp
+The
+.Fn cap_close ,
+.Fn cap_sock
+and
+.Fn cap_unwrap
+functions always succeed.
+.Sh EXAMPLES
+The following example first opens capability to the
+.Xr casperd 8
+daemon, then using this capability creates new capability to the
+.Nm system.dns
+casper service and uses the latter capability to resolve IP address.
+.Bd -literal
+cap_channel_t *capcas, *capdns;
+nvlist_t *limits;
+const char *ipstr = "127.0.0.1";
+struct in_addr ip;
+struct hostent *hp;
+
+/* Open capability to the Casper daemon. */
+capcas = cap_init();
+if (capcas == NULL)
+	err(1, "Unable to contact Casper daemon");
+
+/* Enter capability mode sandbox. */
+if (cap_enter() < 0 && errno != ENOSYS)
+	err(1, "Unable to enter capability mode");
+
+/* Use Casper capability to create capability to the system.dns service. */
+capdns = cap_service_open(capcas, "system.dns");
+if (capdns == NULL)
+	err(1, "Unable to open system.dns service");
+
+/* Close Casper capability, we don't need it anymore. */
+cap_close(capcas);
+
+/* Limit system.dns to reverse DNS lookups and IPv4 addresses. */
+limits = nvlist_create(0);
+nvlist_add_string(limits, "type", "ADDR");
+nvlist_add_number(limits, "family", (uint64_t)AF_INET);
+if (cap_limit_set(capdns, limits) < 0)
+	err("Unable to limit access to the system.dns service");
+
+/* Convert IP address in C-string to in_addr. */
+if (!inet_aton(ipstr, &ip))
+	errx(1, "Unable to parse IP address %s.", ipstr);
+
+/* Find hostname for the given IP address. */
+hp = cap_gethostbyaddr(capdns, (const void *)&ip, sizeof(ip), AF_INET);
+if (hp == NULL)
+	errx(1, "No name associated with %s.", ipstr);
+
+printf("Name associated with %s is %s.\\n", ipstr, hp->h_name);
+.Ed
+.Sh SEE ALSO
+.Xr cap_enter 2 ,
+.Xr execve 2 ,
+.Xr kevent 2 ,
+.Xr poll 2 ,
+.Xr select 2 ,
+.Xr cap_gethostbyaddr 3 ,
+.Xr err 3 ,
+.Xr gethostbyaddr 3 ,
+.Xr inet_aton 3 ,
+.Xr nv 3 ,
+.Xr capsicum 4 ,
+.Xr unix 4 ,
+.Xr casperd 8
+.Sh AUTHORS
+The
+.Nm libcapsicum
+library was implemented by
+.An Pawel Jakub Dawidek Aq pawel@dawidek.net
+under sponsorship from the FreeBSD Foundation.
diff --git a/lib/libcapsicum/libcapsicum.c b/lib/libcapsicum/libcapsicum.c
new file mode 100644
index 0000000..79ca871
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum.c
@@ -0,0 +1,266 @@
+/*-
+ * Copyright (c) 2012-2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "libcapsicum.h"
+#include "libcapsicum_impl.h"
+#include "nv.h"
+
+/*
+ * Structure describing communication channel between two separated processes.
+ */
+#define	CAP_CHANNEL_MAGIC	0xcac8a31
+struct cap_channel {
+	/*
+	 * Magic value helps to ensure that a pointer to the right structure is
+	 * passed to our functions.
+	 */
+	int	cch_magic;
+	/* Socket descriptor for IPC. */
+	int	cch_sock;
+};
+
+bool
+fd_is_valid(int fd)
+{
+
+	return (fcntl(fd, F_GETFL) != -1 || errno != EBADF);
+}
+
+cap_channel_t *
+cap_init(void)
+{
+	cap_channel_t *chan;
+	struct sockaddr_un sun;
+	int serrno, sock;
+
+	bzero(&sun, sizeof(sun));
+	sun.sun_family = AF_UNIX;
+	strlcpy(sun.sun_path, CASPER_SOCKPATH, sizeof(sun.sun_path));
+	sun.sun_len = SUN_LEN(&sun);
+
+	sock = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (sock == -1)
+		return (NULL);
+	if (connect(sock, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
+		serrno = errno;
+		close(sock);
+		errno = serrno;
+		return (NULL);
+	}
+	chan = cap_wrap(sock);
+	if (chan == NULL) {
+		serrno = errno;
+		close(sock);
+		errno = serrno;
+		return (NULL);
+	}
+	return (chan);
+}
+
+cap_channel_t *
+cap_wrap(int sock)
+{
+	cap_channel_t *chan;
+
+	if (!fd_is_valid(sock))
+		return (NULL);
+
+	chan = malloc(sizeof(*chan));
+	if (chan != NULL) {
+		chan->cch_sock = sock;
+		chan->cch_magic = CAP_CHANNEL_MAGIC;
+	}
+
+	return (chan);
+}
+
+int
+cap_unwrap(cap_channel_t *chan)
+{
+	int sock;
+
+	assert(chan != NULL);
+	assert(chan->cch_magic == CAP_CHANNEL_MAGIC);
+
+	sock = chan->cch_sock;
+	chan->cch_magic = 0;
+	free(chan);
+
+	return (sock);
+}
+
+cap_channel_t *
+cap_clone(const cap_channel_t *chan)
+{
+	cap_channel_t *newchan;
+	nvlist_t *nvl;
+	int newsock;
+
+	assert(chan != NULL);
+	assert(chan->cch_magic == CAP_CHANNEL_MAGIC);
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "clone");
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (NULL);
+	if (nvlist_get_number(nvl, "error") != 0) {
+		errno = (int)nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (NULL);
+	}
+	newsock = nvlist_take_descriptor(nvl, "sock");
+	nvlist_destroy(nvl);
+	newchan = cap_wrap(newsock);
+	if (newchan == NULL) {
+		int serrno;
+
+		serrno = errno;
+		close(newsock);
+		errno = serrno;
+	}
+
+	return (newchan);
+}
+
+void
+cap_close(cap_channel_t *chan)
+{
+
+	assert(chan != NULL);
+	assert(chan->cch_magic == CAP_CHANNEL_MAGIC);
+
+	chan->cch_magic = 0;
+	close(chan->cch_sock);
+	free(chan);
+}
+
+int
+cap_sock(const cap_channel_t *chan)
+{
+
+	assert(chan != NULL);
+	assert(chan->cch_magic == CAP_CHANNEL_MAGIC);
+
+	return (chan->cch_sock);
+}
+
+int
+cap_limit_set(const cap_channel_t *chan, nvlist_t *limits)
+{
+	nvlist_t *nvlmsg;
+	int error;
+
+	nvlmsg = nvlist_create(0);
+	nvlist_add_string(nvlmsg, "cmd", "limit_set");
+	nvlist_add_nvlist(nvlmsg, "limits", limits);
+	nvlmsg = cap_xfer_nvlist(chan, nvlmsg);
+	if (nvlmsg == NULL) {
+		nvlist_destroy(limits);
+		return (-1);
+	}
+	error = (int)nvlist_get_number(nvlmsg, "error");
+	nvlist_destroy(nvlmsg);
+	nvlist_destroy(limits);
+	if (error != 0) {
+		errno = error;
+		return (-1);
+	}
+	return (0);
+}
+
+int
+cap_limit_get(const cap_channel_t *chan, nvlist_t **limitsp)
+{
+	nvlist_t *nvlmsg;
+	int error;
+
+	nvlmsg = nvlist_create(0);
+	nvlist_add_string(nvlmsg, "cmd", "limit_get");
+	nvlmsg = cap_xfer_nvlist(chan, nvlmsg);
+	if (nvlmsg == NULL)
+		return (-1);
+	error = (int)nvlist_get_number(nvlmsg, "error");
+	if (error != 0) {
+		nvlist_destroy(nvlmsg);
+		errno = error;
+		return (-1);
+	}
+	if (nvlist_exists_null(nvlmsg, "limits"))
+		*limitsp = NULL;
+	else
+		*limitsp = nvlist_take_nvlist(nvlmsg, "limits");
+	nvlist_destroy(nvlmsg);
+	return (0);
+}
+
+int
+cap_send_nvlist(const cap_channel_t *chan, const nvlist_t *nvl)
+{
+
+	assert(chan != NULL);
+	assert(chan->cch_magic == CAP_CHANNEL_MAGIC);
+
+	return (nvlist_send(chan->cch_sock, nvl));
+}
+
+nvlist_t *
+cap_recv_nvlist(const cap_channel_t *chan)
+{
+
+	assert(chan != NULL);
+	assert(chan->cch_magic == CAP_CHANNEL_MAGIC);
+
+	return (nvlist_recv(chan->cch_sock));
+}
+
+nvlist_t *
+cap_xfer_nvlist(const cap_channel_t *chan, nvlist_t *nvl)
+{
+
+	assert(chan != NULL);
+	assert(chan->cch_magic == CAP_CHANNEL_MAGIC);
+
+	return (nvlist_xfer(chan->cch_sock, nvl));
+}
diff --git a/lib/libcapsicum/libcapsicum.h b/lib/libcapsicum/libcapsicum.h
new file mode 100644
index 0000000..4f8c597
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum.h
@@ -0,0 +1,115 @@
+/*-
+ * Copyright (c) 2012-2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_H_
+#define	_LIBCAPSICUM_H_
+
+#ifndef	_NVLIST_T_DECLARED
+#define	_NVLIST_T_DECLARED
+struct nvlist;
+
+typedef struct nvlist nvlist_t;
+#endif
+
+#ifndef	_CAP_CHANNEL_T_DECLARED
+#define	_CAP_CHANNEL_T_DECLARED
+struct cap_channel;
+
+typedef struct cap_channel cap_channel_t;
+#endif
+
+/*
+ * The function opens unrestricted communication channel to Casper.
+ */
+cap_channel_t *cap_init(void);
+
+/*
+ * The function creates cap_channel_t based on the given socket.
+ */
+cap_channel_t *cap_wrap(int sock);
+
+/*
+ * The function returns communication socket and frees cap_channel_t.
+ */
+int	cap_unwrap(cap_channel_t *chan);
+
+/*
+ * The function clones the given capability.
+ */
+cap_channel_t *cap_clone(const cap_channel_t *chan);
+
+/*
+ * The function closes the given capability.
+ */
+void	cap_close(cap_channel_t *chan);
+
+/*
+ * The function returns socket descriptor associated with the given
+ * cap_channel_t for use with select(2)/kqueue(2)/etc.
+ */
+int	cap_sock(const cap_channel_t *chan);
+
+/*
+ * The function limits the given capability.
+ * It always destroys 'limits' on return.
+ */
+int	cap_limit_set(const cap_channel_t *chan, nvlist_t *limits);
+
+/*
+ * The function returns current limits of the given capability.
+ */
+int	cap_limit_get(const cap_channel_t *chan, nvlist_t **limitsp);
+
+#ifdef TODO
+/*
+ * The function registers a service within provided Casper's capability.
+ * It will run with the same privileges the process has at the time of
+ * calling this function.
+ */
+int	cap_service_register(cap_channel_t *chan, const char *name,
+	    cap_func_t *func);
+#endif
+
+/*
+ * Function sends nvlist over the given capability.
+ */
+int	cap_send_nvlist(const cap_channel_t *chan, const nvlist_t *nvl);
+/*
+ * Function receives nvlist over the given capability.
+ */
+nvlist_t *cap_recv_nvlist(const cap_channel_t *chan);
+/*
+ * Function sends the given nvlist, destroys it and receives new nvlist in
+ * response over the given capability.
+ */
+nvlist_t *cap_xfer_nvlist(const cap_channel_t *chan, nvlist_t *nvl);
+
+#endif	/* !_LIBCAPSICUM_H_ */
diff --git a/lib/libcapsicum/libcapsicum_dns.c b/lib/libcapsicum/libcapsicum_dns.c
new file mode 100644
index 0000000..170e0d0
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_dns.c
@@ -0,0 +1,346 @@
+/*-
+ * Copyright (c) 2012-2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <netdb.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <nv.h>
+
+#include "libcapsicum.h"
+#include "libcapsicum_dns.h"
+
+static struct hostent hent;
+
+static void
+hostent_free(struct hostent *hp)
+{
+	unsigned int ii;
+
+	free(hp->h_name);
+	hp->h_name = NULL;
+	if (hp->h_aliases != NULL) {
+		for (ii = 0; hp->h_aliases[ii] != NULL; ii++)
+			free(hp->h_aliases[ii]);
+		free(hp->h_aliases);
+		hp->h_aliases = NULL;
+	}
+	if (hp->h_addr_list != NULL) {
+		for (ii = 0; hp->h_addr_list[ii] != NULL; ii++)
+			free(hp->h_addr_list[ii]);
+		free(hp->h_addr_list);
+		hp->h_addr_list = NULL;
+	}
+}
+
+static struct hostent *
+hostent_unpack(const nvlist_t *nvl, struct hostent *hp)
+{
+	unsigned int ii, nitems;
+
+	hostent_free(hp);
+
+	hp->h_name = strdup(nvlist_get_string(nvl, "name"));
+	if (hp->h_name == NULL)
+		goto fail;
+	hp->h_addrtype = (int)nvlist_get_number(nvl, "addrtype");
+	hp->h_length = (int)nvlist_get_number(nvl, "length");
+
+	nitems = (unsigned int)nvlist_get_number(nvl, "naliases");
+	hp->h_aliases = calloc(sizeof(hp->h_aliases[0]), nitems + 1);
+	if (hp->h_aliases == NULL)
+		goto fail;
+	for (ii = 0; ii < nitems; ii++) {
+		hp->h_aliases[ii] =
+		    strdup(nvlist_getf_string(nvl, "alias%u", ii));
+		if (hp->h_aliases[ii] == NULL)
+			goto fail;
+	}
+	hp->h_aliases[ii] = NULL;
+
+	nitems = (unsigned int)nvlist_get_number(nvl, "naddrs");
+	hp->h_addr_list = calloc(sizeof(hp->h_addr_list[0]), nitems + 1);
+	if (hp->h_addr_list == NULL)
+		goto fail;
+	for (ii = 0; ii < nitems; ii++) {
+		hp->h_addr_list[ii] = malloc(hp->h_length);
+		if (hp->h_addr_list[ii] == NULL)
+			goto fail;
+		bcopy(nvlist_getf_binary(nvl, NULL, "addr%u", ii),
+		    hp->h_addr_list[ii], hp->h_length);
+	}
+	hp->h_addr_list[ii] = NULL;
+
+	return (hp);
+fail:
+	hostent_free(hp);
+	h_errno = NO_RECOVERY;
+	return (NULL);
+}
+
+struct hostent *
+cap_gethostbyname(cap_channel_t *chan, const char *name)
+{
+
+	return (cap_gethostbyname2(chan, name, AF_INET));
+}
+
+struct hostent *
+cap_gethostbyname2(cap_channel_t *chan, const char *name, int type)
+{
+	struct hostent *hp;
+	nvlist_t *nvl;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "gethostbyname");
+	nvlist_add_number(nvl, "family", (uint64_t)type);
+	nvlist_add_string(nvl, "name", name);
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL) {
+		h_errno = NO_RECOVERY;
+		return (NULL);
+	}
+	if (nvlist_get_number(nvl, "error") != 0) {
+		h_errno = (int)nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (NULL);
+	}
+
+	hp = hostent_unpack(nvl, &hent);
+	nvlist_destroy(nvl);
+	return (hp);
+}
+
+struct hostent *
+cap_gethostbyaddr(cap_channel_t *chan, const void *addr, socklen_t len,
+    int type)
+{
+	struct hostent *hp;
+	nvlist_t *nvl;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "gethostbyaddr");
+	nvlist_add_binary(nvl, "addr", addr, (size_t)len);
+	nvlist_add_number(nvl, "family", (uint64_t)type);
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL) {
+		h_errno = NO_RECOVERY;
+		return (NULL);
+	}
+	if (nvlist_get_number(nvl, "error") != 0) {
+		h_errno = (int)nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (NULL);
+	}
+	hp = hostent_unpack(nvl, &hent);
+	nvlist_destroy(nvl);
+	return (hp);
+}
+
+static struct addrinfo *
+addrinfo_unpack(const nvlist_t *nvl)
+{
+	struct addrinfo *ai;
+	const void *addr;
+	size_t addrlen;
+	const char *canonname;
+
+	addr = nvlist_get_binary(nvl, "ai_addr", &addrlen);
+	ai = malloc(sizeof(*ai) + addrlen);
+	if (ai == NULL)
+		return (NULL);
+	ai->ai_flags = (int)nvlist_get_number(nvl, "ai_flags");
+	ai->ai_family = (int)nvlist_get_number(nvl, "ai_family");
+	ai->ai_socktype = (int)nvlist_get_number(nvl, "ai_socktype");
+	ai->ai_protocol = (int)nvlist_get_number(nvl, "ai_protocol");
+	ai->ai_addrlen = (socklen_t)addrlen;
+	canonname = nvlist_get_string(nvl, "ai_canonname");
+	if (canonname != NULL) {
+		ai->ai_canonname = strdup(canonname);
+		if (ai->ai_canonname == NULL) {
+			free(ai);
+			return (NULL);
+		}
+	} else {
+		ai->ai_canonname = NULL;
+	}
+	ai->ai_addr = (void *)(ai + 1);
+	bcopy(addr, ai->ai_addr, addrlen);
+	ai->ai_next = NULL;
+
+	return (ai);
+}
+
+int
+cap_getaddrinfo(cap_channel_t *chan, const char *hostname, const char *servname,
+    const struct addrinfo *hints, struct addrinfo **res)
+{
+	struct addrinfo *firstai, *prevai, *curai;
+	unsigned int ii;
+	const nvlist_t *nvlai;
+	nvlist_t *nvl;
+	int error;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "getaddrinfo");
+	nvlist_add_string(nvl, "hostname", hostname);
+	nvlist_add_string(nvl, "servname", servname);
+	if (hints != NULL) {
+		nvlist_add_number(nvl, "hints.ai_flags",
+		    (uint64_t)hints->ai_flags);
+		nvlist_add_number(nvl, "hints.ai_family",
+		    (uint64_t)hints->ai_family);
+		nvlist_add_number(nvl, "hints.ai_socktype",
+		    (uint64_t)hints->ai_socktype);
+		nvlist_add_number(nvl, "hints.ai_protocol",
+		    (uint64_t)hints->ai_protocol);
+	}
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (EAI_MEMORY);
+	if (nvlist_get_number(nvl, "error") != 0) {
+		error = (int)nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (error);
+	}
+
+	nvlai = NULL;
+	firstai = prevai = curai = NULL;
+	for (ii = 0; ; ii++) {
+		if (!nvlist_existsf_nvlist(nvl, "res%u", ii))
+			break;
+		nvlai = nvlist_getf_nvlist(nvl, "res%u", ii);
+		curai = addrinfo_unpack(nvlai);
+		if (curai == NULL)
+			break;
+		if (prevai != NULL)
+			prevai->ai_next = curai;
+		else if (firstai == NULL)
+			firstai = curai;
+	}
+	nvlist_destroy(nvl);
+	if (curai == NULL && nvlai != NULL) {
+		if (firstai == NULL)
+			freeaddrinfo(firstai);
+		return (EAI_MEMORY);
+	}
+
+	*res = firstai;
+	return (0);
+}
+
+int
+cap_getnameinfo(cap_channel_t *chan, const struct sockaddr *sa, socklen_t salen,
+    char *host, size_t hostlen, char *serv, size_t servlen, int flags)
+{
+	nvlist_t *nvl;
+	int error;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "getnameinfo");
+	nvlist_add_number(nvl, "hostlen", (uint64_t)hostlen);
+	nvlist_add_number(nvl, "servlen", (uint64_t)servlen);
+	nvlist_add_binary(nvl, "sa", sa, (size_t)salen);
+	nvlist_add_number(nvl, "flags", (uint64_t)flags);
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (EAI_MEMORY);
+	if (nvlist_get_number(nvl, "error") != 0) {
+		error = (int)nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (error);
+	}
+
+	if (host != NULL)
+		strlcpy(host, nvlist_get_string(nvl, "host"), hostlen + 1);
+	if (serv != NULL)
+		strlcpy(serv, nvlist_get_string(nvl, "serv"), servlen + 1);
+	nvlist_destroy(nvl);
+	return (0);
+}
+
+static void
+limit_remove(nvlist_t *limits, const char *prefix)
+{
+	const char *name;
+	size_t prefixlen;
+	void *cookie;
+
+	prefixlen = strlen(prefix);
+again:
+	cookie = NULL;
+	while ((name = nvlist_next(limits, NULL, &cookie)) != NULL) {
+		if (strncmp(name, prefix, prefixlen) == 0) {
+			nvlist_free(limits, name);
+			goto again;
+		}
+	}
+}
+
+int
+cap_dns_type_limit(cap_channel_t *chan, const char * const *types,
+    size_t ntypes)
+{
+	nvlist_t *limits;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL)
+		limits = nvlist_create(0);
+	else
+		limit_remove(limits, "type");
+	for (i = 0; i < ntypes; i++)
+		nvlist_addf_string(limits, types[i], "type%u", i);
+	return (cap_limit_set(chan, limits));
+}
+
+int
+cap_dns_family_limit(cap_channel_t *chan, const int *families,
+    size_t nfamilies)
+{
+	nvlist_t *limits;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL)
+		limits = nvlist_create(0);
+	else
+		limit_remove(limits, "family");
+	for (i = 0; i < nfamilies; i++) {
+		nvlist_addf_number(limits, (uint64_t)families[i],
+		    "family%u", i);
+	}
+	return (cap_limit_set(chan, limits));
+}
diff --git a/lib/libcapsicum/libcapsicum_dns.h b/lib/libcapsicum/libcapsicum_dns.h
new file mode 100644
index 0000000..0223510
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_dns.h
@@ -0,0 +1,57 @@
+/*-
+ * Copyright (c) 2012 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_DNS_H_
+#define	_LIBCAPSICUM_DNS_H_
+
+#include <sys/socket.h>	/* socklen_t */
+
+struct addrinfo;
+struct hostent;
+
+struct hostent *cap_gethostbyname(cap_channel_t *chan, const char *name);
+struct hostent *cap_gethostbyname2(cap_channel_t *chan, const char *name,
+    int type);
+struct hostent *cap_gethostbyaddr(cap_channel_t *chan, const void *addr,
+    socklen_t len, int type);
+
+int cap_getaddrinfo(cap_channel_t *chan, const char *hostname,
+    const char *servname, const struct addrinfo *hints, struct addrinfo **res);
+int cap_getnameinfo(cap_channel_t *chan, const struct sockaddr *sa,
+    socklen_t salen, char *host, size_t hostlen, char *serv, size_t servlen,
+    int flags);
+
+int cap_dns_type_limit(cap_channel_t *chan, const char * const *types,
+    size_t ntypes);
+int cap_dns_family_limit(cap_channel_t *chan, const int *families,
+    size_t nfamilies);
+
+#endif	/* !_LIBCAPSICUM_DNS_H_ */
diff --git a/lib/libcapsicum/libcapsicum_grp.c b/lib/libcapsicum/libcapsicum_grp.c
new file mode 100644
index 0000000..c679ce9
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_grp.c
@@ -0,0 +1,426 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <grp.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <dnv.h>
+#include <nv.h>
+
+#include "libcapsicum.h"
+#include "libcapsicum_grp.h"
+
+static struct group ggrp;
+static char *gbuffer;
+static size_t gbufsize;
+
+static int
+group_resize(void)
+{
+	char *buf;
+
+	if (gbufsize == 0)
+		gbufsize = 1024;
+	else
+		gbufsize *= 2;
+
+	buf = gbuffer;
+	gbuffer = realloc(buf, gbufsize);
+	if (gbuffer == NULL) {
+		free(buf);
+		gbufsize = 0;
+		return (ENOMEM);
+	}
+	memset(gbuffer, 0, gbufsize);
+
+	return (0);
+}
+
+static int
+group_unpack_string(const nvlist_t *nvl, const char *fieldname, char **fieldp,
+    char **bufferp, size_t *bufsizep)
+{
+	const char *str;
+	size_t len;
+
+	str = nvlist_get_string(nvl, fieldname);
+	len = strlcpy(*bufferp, str, *bufsizep);
+	if (len >= *bufsizep)
+		return (ERANGE);
+	*fieldp = *bufferp;
+	*bufferp += len + 1;
+	*bufsizep -= len + 1;
+
+	return (0);
+}
+
+static int
+group_unpack_members(const nvlist_t *nvl, char ***fieldp, char **bufferp,
+    size_t *bufsizep)
+{
+	const char *mem;
+	char **outstrs, *str;
+	size_t nmem, datasize, strsize;
+	unsigned int ii;
+
+	if (!nvlist_exists_number(nvl, "gr_nmem")) {
+		datasize = _ALIGNBYTES + sizeof(char *);
+		if (datasize >= *bufsizep)
+			return (ERANGE);
+		outstrs = (char **)_ALIGN(*bufferp);
+		outstrs[0] = NULL;
+		*fieldp = outstrs;
+		*bufferp += datasize;
+		*bufsizep -= datasize;
+		return (0);
+	}
+
+	nmem = (size_t)nvlist_get_number(nvl, "gr_nmem");
+	datasize = _ALIGNBYTES + sizeof(char *) * (nmem + 1);
+	for (ii = 0; ii < nmem; ii++) {
+		mem = dnvlist_getf_string(nvl, NULL, "gr_mem[%u]", ii);
+		if (mem == NULL)
+			return (EINVAL);
+		datasize += strlen(mem) + 1;
+	}
+
+	if (datasize >= *bufsizep)
+		return (ERANGE);
+
+	outstrs = (char **)_ALIGN(*bufferp);
+	str = (char *)outstrs + sizeof(char *) * (nmem + 1);
+	for (ii = 0; ii < nmem; ii++) {
+		mem = nvlist_getf_string(nvl, "gr_mem[%u]", ii);
+		strsize = strlen(mem) + 1;
+		memcpy(str, mem, strsize);
+		outstrs[ii] = str;
+		str += strsize;
+	}
+	assert(ii == nmem);
+	outstrs[ii] = NULL;
+
+	*fieldp = outstrs;
+	*bufferp += datasize;
+	*bufsizep -= datasize;
+
+	return (0);
+}
+
+static int
+group_unpack(const nvlist_t *nvl, struct group *grp, char *buffer,
+    size_t bufsize)
+{
+	int error;
+
+	if (!nvlist_exists_string(nvl, "gr_name"))
+		return (EINVAL);
+
+	memset(grp, 0, sizeof(*grp));
+
+	error = group_unpack_string(nvl, "gr_name", &grp->gr_name, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	error = group_unpack_string(nvl, "gr_passwd", &grp->gr_passwd, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	grp->gr_gid = (gid_t)nvlist_get_number(nvl, "gr_gid");
+	error = group_unpack_members(nvl, &grp->gr_mem, &buffer, &bufsize);
+	if (error != 0)
+		return (error);
+
+	return (0);
+}
+
+static int
+cap_getgrcommon_r(cap_channel_t *chan, const char *cmd, const char *name,
+    gid_t gid, struct group *grp, char *buffer, size_t bufsize,
+    struct group **result)
+{
+	nvlist_t *nvl;
+	bool getgr_r;
+	int error;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", cmd);
+	if (strcmp(cmd, "getgrent") == 0 || strcmp(cmd, "getgrent_r") == 0) {
+		/* Add nothing. */
+	} else if (strcmp(cmd, "getgrnam") == 0 ||
+	    strcmp(cmd, "getgrnam_r") == 0) {
+		nvlist_add_string(nvl, "name", name);
+	} else if (strcmp(cmd, "getgrgid") == 0 ||
+	    strcmp(cmd, "getgrgid_r") == 0) {
+		nvlist_add_number(nvl, "gid", (uint64_t)gid);
+	} else {
+		abort();
+	}
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL) {
+		assert(errno != 0);
+		*result = NULL;
+		return (errno);
+	}
+	error = (int)nvlist_get_number(nvl, "error");
+	if (error != 0) {
+		nvlist_destroy(nvl);
+		*result = NULL;
+		return (error);
+	}
+
+	if (!nvlist_exists_string(nvl, "gr_name")) {
+		/* Not found. */
+		nvlist_destroy(nvl);
+		*result = NULL;
+		return (0);
+	}
+
+	getgr_r = (strcmp(cmd, "getgrent_r") == 0 ||
+	    strcmp(cmd, "getgrnam_r") == 0 || strcmp(cmd, "getgrgid_r") == 0);
+
+	for (;;) {
+		error = group_unpack(nvl, grp, buffer, bufsize);
+		if (getgr_r || error != ERANGE)
+			break;
+		assert(buffer == gbuffer);
+		assert(bufsize == gbufsize);
+		error = group_resize();
+		if (error != 0)
+			break;
+		/* Update pointers after resize. */
+		buffer = gbuffer;
+		bufsize = gbufsize;
+	}
+
+	nvlist_destroy(nvl);
+
+	if (error == 0)
+		*result = grp;
+	else
+		*result = NULL;
+
+	return (error);
+}
+
+static struct group *
+cap_getgrcommon(cap_channel_t *chan, const char *cmd, const char *name,
+    gid_t gid)
+{
+	struct group *result;
+	int error, serrno;
+
+	serrno = errno;
+
+	error = cap_getgrcommon_r(chan, cmd, name, gid, &ggrp, gbuffer,
+	    gbufsize, &result);
+	if (error != 0) {
+		errno = error;
+		return (NULL);
+	}
+
+	errno = serrno;
+
+	return (result);
+}
+
+struct group *
+cap_getgrent(cap_channel_t *chan)
+{
+
+	return (cap_getgrcommon(chan, "getgrent", NULL, 0));
+}
+
+struct group *
+cap_getgrnam(cap_channel_t *chan, const char *name)
+{
+
+	return (cap_getgrcommon(chan, "getgrnam", name, 0));
+}
+
+struct group *
+cap_getgrgid(cap_channel_t *chan, gid_t gid)
+{
+
+	return (cap_getgrcommon(chan, "getgrgid", NULL, gid));
+}
+
+int
+cap_getgrent_r(cap_channel_t *chan, struct group *grp, char *buffer,
+    size_t bufsize, struct group **result)
+{
+
+	return (cap_getgrcommon_r(chan, "getgrent_r", NULL, 0, grp, buffer,
+	    bufsize, result));
+}
+
+int
+cap_getgrnam_r(cap_channel_t *chan, const char *name, struct group *grp,
+    char *buffer, size_t bufsize, struct group **result)
+{
+
+	return (cap_getgrcommon_r(chan, "getgrnam_r", name, 0, grp, buffer,
+	    bufsize, result));
+}
+
+int
+cap_getgrgid_r(cap_channel_t *chan, gid_t gid, struct group *grp, char *buffer,
+    size_t bufsize, struct group **result)
+{
+
+	return (cap_getgrcommon_r(chan, "getgrgid_r", NULL, gid, grp, buffer,
+	    bufsize, result));
+}
+
+int
+cap_setgroupent(cap_channel_t *chan, int stayopen)
+{
+	nvlist_t *nvl;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "setgroupent");
+	nvlist_add_bool(nvl, "stayopen", stayopen != 0);
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (0);
+	if (nvlist_get_number(nvl, "error") != 0) {
+		errno = nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (0);
+	}
+	nvlist_destroy(nvl);
+
+	return (1);
+}
+
+int
+cap_setgrent(cap_channel_t *chan)
+{
+	nvlist_t *nvl;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "setgrent");
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (0);
+	if (nvlist_get_number(nvl, "error") != 0) {
+		errno = nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (0);
+	}
+	nvlist_destroy(nvl);
+
+	return (1);
+}
+
+void
+cap_endgrent(cap_channel_t *chan)
+{
+	nvlist_t *nvl;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "endgrent");
+	/* Ignore any errors, we have no way to report them. */
+	nvlist_destroy(cap_xfer_nvlist(chan, nvl));
+}
+
+int
+cap_grp_limit_cmds(cap_channel_t *chan, const char * const *cmds, size_t ncmds)
+{
+	nvlist_t *limits, *nvl;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL) {
+		limits = nvlist_create(0);
+	} else {
+		if (nvlist_exists_nvlist(limits, "cmds"))
+			nvlist_free_nvlist(limits, "cmds");
+	}
+	nvl = nvlist_create(0);
+	for (i = 0; i < ncmds; i++)
+		nvlist_add_null(nvl, cmds[i]);
+	nvlist_move_nvlist(limits, "cmds", nvl);
+	return (cap_limit_set(chan, limits));
+}
+
+int
+cap_grp_limit_fields(cap_channel_t *chan, const char * const *fields,
+    size_t nfields)
+{
+	nvlist_t *limits, *nvl;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL) {
+		limits = nvlist_create(0);
+	} else {
+		if (nvlist_exists_nvlist(limits, "fields"))
+			nvlist_free_nvlist(limits, "fields");
+	}
+	nvl = nvlist_create(0);
+	for (i = 0; i < nfields; i++)
+		nvlist_add_null(nvl, fields[i]);
+	nvlist_move_nvlist(limits, "fields", nvl);
+	return (cap_limit_set(chan, limits));
+}
+
+int
+cap_grp_limit_groups(cap_channel_t *chan, const char * const *names,
+    size_t nnames, gid_t *gids, size_t ngids)
+{
+	nvlist_t *limits, *groups;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL) {
+		limits = nvlist_create(0);
+	} else {
+		if (nvlist_exists_nvlist(limits, "groups"))
+			nvlist_free_nvlist(limits, "groups");
+	}
+	groups = nvlist_create(0);
+	for (i = 0; i < ngids; i++)
+		nvlist_addf_number(groups, (uint64_t)gids[i], "gid%u", i);
+	for (i = 0; i < nnames; i++)
+		nvlist_addf_string(groups, names[i], "name%u", i);
+	nvlist_move_nvlist(limits, "groups", groups);
+	return (cap_limit_set(chan, limits));
+}
diff --git a/lib/libcapsicum/libcapsicum_grp.h b/lib/libcapsicum/libcapsicum_grp.h
new file mode 100644
index 0000000..e0b44f0
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_grp.h
@@ -0,0 +1,57 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_GRP_H_
+#define	_LIBCAPSICUM_GRP_H_
+
+struct group *cap_getgrent(cap_channel_t *chan);
+struct group *cap_getgrnam(cap_channel_t *chan, const char *name);
+struct group *cap_getgrgid(cap_channel_t *chan, gid_t gid);
+
+int cap_getgrent_r(cap_channel_t *chan, struct group *grp, char *buffer,
+    size_t bufsize, struct group **result);
+int cap_getgrnam_r(cap_channel_t *chan, const char *name, struct group *grp,
+    char *buffer, size_t bufsize, struct group **result);
+int cap_getgrgid_r(cap_channel_t *chan, gid_t gid, struct group *grp,
+    char *buffer, size_t bufsize, struct group **result);
+
+int cap_setgroupent(cap_channel_t *chan, int stayopen);
+int cap_setgrent(cap_channel_t *chan);
+void cap_endgrent(cap_channel_t *chan);
+
+int cap_grp_limit_cmds(cap_channel_t *chan, const char * const *cmds,
+    size_t ncmds);
+int cap_grp_limit_fields(cap_channel_t *chan, const char * const *fields,
+    size_t nfields);
+int cap_grp_limit_groups(cap_channel_t *chan, const char * const *names,
+    size_t nnames, gid_t *gids, size_t ngids);
+
+#endif	/* !_LIBCAPSICUM_GRP_H_ */
diff --git a/lib/libcapsicum/libcapsicum_impl.h b/lib/libcapsicum/libcapsicum_impl.h
new file mode 100644
index 0000000..ce6f49f
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_impl.h
@@ -0,0 +1,39 @@
+/*-
+ * Copyright (c) 2012-2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_IMPL_H_
+#define	_LIBCAPSICUM_IMPL_H_
+
+#define	CASPER_SOCKPATH	"/var/run/casper"
+
+bool	fd_is_valid(int fd);
+
+#endif	/* !_LIBCAPSICUM_IMPL_H_ */
diff --git a/lib/libcapsicum/libcapsicum_pwd.c b/lib/libcapsicum/libcapsicum_pwd.c
new file mode 100644
index 0000000..792fb66
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_pwd.c
@@ -0,0 +1,384 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <nv.h>
+
+#include "libcapsicum.h"
+#include "libcapsicum_pwd.h"
+
+static struct passwd gpwd;
+static char *gbuffer;
+static size_t gbufsize;
+
+static int
+passwd_resize(void)
+{
+	char *buf;
+
+	if (gbufsize == 0)
+		gbufsize = 1024;
+	else
+		gbufsize *= 2;
+
+	buf = gbuffer;
+	gbuffer = realloc(buf, gbufsize);
+	if (gbuffer == NULL) {
+		free(buf);
+		gbufsize = 0;
+		return (ENOMEM);
+	}
+	memset(gbuffer, 0, gbufsize);
+
+	return (0);
+}
+
+static int
+passwd_unpack_string(const nvlist_t *nvl, const char *fieldname, char **fieldp,
+    char **bufferp, size_t *bufsizep)
+{
+	const char *str;
+	size_t len;
+
+	str = nvlist_get_string(nvl, fieldname);
+	len = strlcpy(*bufferp, str, *bufsizep);
+	if (len >= *bufsizep)
+		return (ERANGE);
+	*fieldp = *bufferp;
+	*bufferp += len + 1;
+	*bufsizep -= len + 1;
+
+	return (0);
+}
+
+static int
+passwd_unpack(const nvlist_t *nvl, struct passwd *pwd, char *buffer,
+    size_t bufsize)
+{
+	int error;
+
+	if (!nvlist_exists_string(nvl, "pw_name"))
+		return (EINVAL);
+
+	memset(pwd, 0, sizeof(*pwd));
+
+	error = passwd_unpack_string(nvl, "pw_name", &pwd->pw_name, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	pwd->pw_uid = (uid_t)nvlist_get_number(nvl, "pw_uid");
+	pwd->pw_gid = (gid_t)nvlist_get_number(nvl, "pw_gid");
+	pwd->pw_change = (time_t)nvlist_get_number(nvl, "pw_change");
+	error = passwd_unpack_string(nvl, "pw_passwd", &pwd->pw_passwd, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	error = passwd_unpack_string(nvl, "pw_class", &pwd->pw_class, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	error = passwd_unpack_string(nvl, "pw_gecos", &pwd->pw_gecos, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	error = passwd_unpack_string(nvl, "pw_dir", &pwd->pw_dir, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	error = passwd_unpack_string(nvl, "pw_shell", &pwd->pw_shell, &buffer,
+	    &bufsize);
+	if (error != 0)
+		return (error);
+	pwd->pw_expire = (time_t)nvlist_get_number(nvl, "pw_expire");
+	pwd->pw_fields = (int)nvlist_get_number(nvl, "pw_fields");
+
+	return (0);
+}
+
+static int
+cap_getpwcommon_r(cap_channel_t *chan, const char *cmd, const char *login,
+    uid_t uid, struct passwd *pwd, char *buffer, size_t bufsize,
+    struct passwd **result)
+{
+	nvlist_t *nvl;
+	bool getpw_r;
+	int error;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", cmd);
+	if (strcmp(cmd, "getpwent") == 0 || strcmp(cmd, "getpwent_r") == 0) {
+		/* Add nothing. */
+	} else if (strcmp(cmd, "getpwnam") == 0 ||
+	    strcmp(cmd, "getpwnam_r") == 0) {
+		nvlist_add_string(nvl, "name", login);
+	} else if (strcmp(cmd, "getpwuid") == 0 ||
+	    strcmp(cmd, "getpwuid_r") == 0) {
+		nvlist_add_number(nvl, "uid", (uint64_t)uid);
+	} else {
+		abort();
+	}
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL) {
+		assert(errno != 0);
+		*result = NULL;
+		return (errno);
+	}
+	error = (int)nvlist_get_number(nvl, "error");
+	if (error != 0) {
+		nvlist_destroy(nvl);
+		*result = NULL;
+		return (error);
+	}
+
+	if (!nvlist_exists_string(nvl, "pw_name")) {
+		/* Not found. */
+		nvlist_destroy(nvl);
+		*result = NULL;
+		return (0);
+	}
+
+	getpw_r = (strcmp(cmd, "getpwent_r") == 0 ||
+	    strcmp(cmd, "getpwnam_r") == 0 || strcmp(cmd, "getpwuid_r") == 0);
+
+	for (;;) {
+		error = passwd_unpack(nvl, pwd, buffer, bufsize);
+		if (getpw_r || error != ERANGE)
+			break;
+		assert(buffer == gbuffer);
+		assert(bufsize == gbufsize);
+		error = passwd_resize();
+		if (error != 0)
+			break;
+		/* Update pointers after resize. */
+		buffer = gbuffer;
+		bufsize = gbufsize;
+	}
+
+	nvlist_destroy(nvl);
+
+	if (error == 0)
+		*result = pwd;
+	else
+		*result = NULL;
+
+	return (error);
+}
+
+static struct passwd *
+cap_getpwcommon(cap_channel_t *chan, const char *cmd, const char *login,
+    uid_t uid)
+{
+	struct passwd *result;
+	int error, serrno;
+
+	serrno = errno;
+
+	error = cap_getpwcommon_r(chan, cmd, login, uid, &gpwd, gbuffer,
+	    gbufsize, &result);
+	if (error != 0) {
+		errno = error;
+		return (NULL);
+	}
+
+	errno = serrno;
+
+	return (result);
+}
+
+struct passwd *
+cap_getpwent(cap_channel_t *chan)
+{
+
+	return (cap_getpwcommon(chan, "getpwent", NULL, 0));
+}
+
+struct passwd *
+cap_getpwnam(cap_channel_t *chan, const char *login)
+{
+
+	return (cap_getpwcommon(chan, "getpwnam", login, 0));
+}
+
+struct passwd *
+cap_getpwuid(cap_channel_t *chan, uid_t uid)
+{
+
+	return (cap_getpwcommon(chan, "getpwuid", NULL, uid));
+}
+
+int
+cap_getpwent_r(cap_channel_t *chan, struct passwd *pwd, char *buffer,
+    size_t bufsize, struct passwd **result)
+{
+
+	return (cap_getpwcommon_r(chan, "getpwent_r", NULL, 0, pwd, buffer,
+	    bufsize, result));
+}
+
+int
+cap_getpwnam_r(cap_channel_t *chan, const char *name, struct passwd *pwd,
+    char *buffer, size_t bufsize, struct passwd **result)
+{
+
+	return (cap_getpwcommon_r(chan, "getpwnam_r", name, 0, pwd, buffer,
+	    bufsize, result));
+}
+
+int
+cap_getpwuid_r(cap_channel_t *chan, uid_t uid, struct passwd *pwd, char *buffer,
+    size_t bufsize, struct passwd **result)
+{
+
+	return (cap_getpwcommon_r(chan, "getpwuid_r", NULL, uid, pwd, buffer,
+	    bufsize, result));
+}
+
+int
+cap_setpassent(cap_channel_t *chan, int stayopen)
+{
+	nvlist_t *nvl;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "setpassent");
+	nvlist_add_bool(nvl, "stayopen", stayopen != 0);
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (0);
+	if (nvlist_get_number(nvl, "error") != 0) {
+		errno = nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (0);
+	}
+	nvlist_destroy(nvl);
+
+	return (1);
+}
+
+static void
+cap_set_end_pwent(cap_channel_t *chan, const char *cmd)
+{
+	nvlist_t *nvl;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", cmd);
+	/* Ignore any errors, we have no way to report them. */
+	nvlist_destroy(cap_xfer_nvlist(chan, nvl));
+}
+
+void
+cap_setpwent(cap_channel_t *chan)
+{
+
+	cap_set_end_pwent(chan, "setpwent");
+}
+
+void
+cap_endpwent(cap_channel_t *chan)
+{
+
+	cap_set_end_pwent(chan, "endpwent");
+}
+
+int
+cap_pwd_limit_cmds(cap_channel_t *chan, const char * const *cmds, size_t ncmds)
+{
+	nvlist_t *limits, *nvl;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL) {
+		limits = nvlist_create(0);
+	} else {
+		if (nvlist_exists_nvlist(limits, "cmds"))
+			nvlist_free_nvlist(limits, "cmds");
+	}
+	nvl = nvlist_create(0);
+	for (i = 0; i < ncmds; i++)
+		nvlist_add_null(nvl, cmds[i]);
+	nvlist_move_nvlist(limits, "cmds", nvl);
+	return (cap_limit_set(chan, limits));
+}
+
+int
+cap_pwd_limit_fields(cap_channel_t *chan, const char * const *fields,
+    size_t nfields)
+{
+	nvlist_t *limits, *nvl;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL) {
+		limits = nvlist_create(0);
+	} else {
+		if (nvlist_exists_nvlist(limits, "fields"))
+			nvlist_free_nvlist(limits, "fields");
+	}
+	nvl = nvlist_create(0);
+	for (i = 0; i < nfields; i++)
+		nvlist_add_null(nvl, fields[i]);
+	nvlist_move_nvlist(limits, "fields", nvl);
+	return (cap_limit_set(chan, limits));
+}
+
+int
+cap_pwd_limit_users(cap_channel_t *chan, const char * const *names,
+    size_t nnames, uid_t *uids, size_t nuids)
+{
+	nvlist_t *limits, *users;
+	unsigned int i;
+
+	if (cap_limit_get(chan, &limits) < 0)
+		return (-1);
+	if (limits == NULL) {
+		limits = nvlist_create(0);
+	} else {
+		if (nvlist_exists_nvlist(limits, "users"))
+			nvlist_free_nvlist(limits, "users");
+	}
+	users = nvlist_create(0);
+	for (i = 0; i < nuids; i++)
+		nvlist_addf_number(users, (uint64_t)uids[i], "uid%u", i);
+	for (i = 0; i < nnames; i++)
+		nvlist_addf_string(users, names[i], "name%u", i);
+	nvlist_move_nvlist(limits, "users", users);
+	return (cap_limit_set(chan, limits));
+}
diff --git a/lib/libcapsicum/libcapsicum_pwd.h b/lib/libcapsicum/libcapsicum_pwd.h
new file mode 100644
index 0000000..960a490
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_pwd.h
@@ -0,0 +1,57 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_PWD_H_
+#define	_LIBCAPSICUM_PWD_H_
+
+struct passwd *cap_getpwent(cap_channel_t *chan);
+struct passwd *cap_getpwnam(cap_channel_t *chan, const char *login);
+struct passwd *cap_getpwuid(cap_channel_t *chan, uid_t uid);
+
+int cap_getpwent_r(cap_channel_t *chan, struct passwd *pwd, char *buffer,
+    size_t bufsize, struct passwd **result);
+int cap_getpwnam_r(cap_channel_t *chan, const char *name, struct passwd *pwd,
+    char *buffer, size_t bufsize, struct passwd **result);
+int cap_getpwuid_r(cap_channel_t *chan, uid_t uid, struct passwd *pwd,
+    char *buffer, size_t bufsize, struct passwd **result);
+
+int cap_setpassent(cap_channel_t *chan, int stayopen);
+void cap_setpwent(cap_channel_t *chan);
+void cap_endpwent(cap_channel_t *chan);
+
+int cap_pwd_limit_cmds(cap_channel_t *chan, const char * const *cmds,
+    size_t ncmds);
+int cap_pwd_limit_fields(cap_channel_t *chan, const char * const *fields,
+    size_t nfields);
+int cap_pwd_limit_users(cap_channel_t *chan, const char * const *names,
+    size_t nnames, uid_t *uids, size_t nuids);
+
+#endif	/* !_LIBCAPSICUM_PWD_H_ */
diff --git a/lib/libcapsicum/libcapsicum_random.c b/lib/libcapsicum/libcapsicum_random.c
new file mode 100644
index 0000000..eed97e2
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_random.c
@@ -0,0 +1,80 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+
+#include <nv.h>
+
+#include "libcapsicum.h"
+#include "libcapsicum_random.h"
+
+#define	MAXSIZE	(1024 * 1024)
+
+int
+cap_random_buf(cap_channel_t *chan, void *buf, size_t nbytes)
+{
+	nvlist_t *nvl;
+	const void *randbuf;
+	uint8_t *ptr;
+	size_t left, randbufsize;
+
+	left = nbytes;
+	ptr = buf;
+
+	while (left > 0) {
+		nvl = nvlist_create(0);
+		nvlist_add_string(nvl, "cmd", "generate");
+		nvlist_add_number(nvl, "size",
+		    (uint64_t)(left > MAXSIZE ? MAXSIZE : left));
+		nvl = cap_xfer_nvlist(chan, nvl);
+		if (nvl == NULL)
+			return (-1);
+		if (nvlist_get_number(nvl, "error") != 0) {
+			errno = (int)nvlist_get_number(nvl, "error");
+			nvlist_destroy(nvl);
+			return (-1);
+		}
+
+		randbuf = nvlist_get_binary(nvl, "data", &randbufsize);
+		memcpy(ptr, randbuf, randbufsize);
+
+		nvlist_destroy(nvl);
+
+		ptr += randbufsize;
+		assert(left >= randbufsize);
+		left -= randbufsize;
+	}
+
+	return (0);
+}
diff --git a/lib/libcapsicum/libcapsicum_random.h b/lib/libcapsicum/libcapsicum_random.h
new file mode 100644
index 0000000..672afa0
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_random.h
@@ -0,0 +1,37 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_RANDOM_H_
+#define	_LIBCAPSICUM_RANDOM_H_
+
+int cap_random_buf(cap_channel_t *chan, void *buf, size_t nbytes);
+
+#endif	/* !_LIBCAPSICUM_RANDOM_H_ */
diff --git a/lib/libcapsicum/libcapsicum_service.c b/lib/libcapsicum/libcapsicum_service.c
new file mode 100644
index 0000000..4127668
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_service.c
@@ -0,0 +1,96 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <nv.h>
+#include "msgio.h"
+
+#include "libcapsicum.h"
+#include "libcapsicum_impl.h"
+#include "libcapsicum_service.h"
+
+cap_channel_t *
+cap_service_open(const cap_channel_t *chan, const char *name)
+{
+	cap_channel_t *newchan;
+	nvlist_t *nvl;
+	int sock, error;
+
+	sock = -1;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "open");
+	nvlist_add_string(nvl, "service", name);
+	if (fd_is_valid(STDERR_FILENO))
+		nvlist_add_descriptor(nvl, "stderrfd", STDERR_FILENO);
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (NULL);
+	error = (int)nvlist_get_number(nvl, "error");
+	if (error != 0) {
+		nvlist_destroy(nvl);
+		errno = error;
+		return (NULL);
+	}
+	sock = nvlist_take_descriptor(nvl, "chanfd");
+	assert(sock >= 0);
+	nvlist_destroy(nvl);
+	nvl = NULL;
+	if (cred_send(sock) == -1)
+		goto fail;
+	newchan = cap_wrap(sock);
+	if (newchan == NULL)
+		goto fail;
+	return (newchan);
+fail:
+	error = errno;
+	close(sock);
+	errno = error;
+	return (NULL);
+}
+
+int
+cap_service_limit(const cap_channel_t *chan, const char * const *names,
+    size_t nnames)
+{
+	nvlist_t *limits;
+	unsigned int i;
+
+	limits = nvlist_create(0);
+	for (i = 0; i < nnames; i++)
+		nvlist_add_null(limits, names[i]);
+	return (cap_limit_set(chan, limits));
+}
diff --git a/lib/libcapsicum/libcapsicum_service.h b/lib/libcapsicum/libcapsicum_service.h
new file mode 100644
index 0000000..05c654f
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_service.h
@@ -0,0 +1,40 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_SERVICE_H_
+#define	_LIBCAPSICUM_SERVICE_H_
+
+cap_channel_t *cap_service_open(const cap_channel_t *chan, const char *name);
+
+int cap_service_limit(const cap_channel_t *chan, const char * const *names,
+    size_t nnames);
+
+#endif	/* !_LIBCAPSICUM_SERVICE_H_ */
diff --git a/lib/libcapsicum/libcapsicum_sysctl.c b/lib/libcapsicum/libcapsicum_sysctl.c
new file mode 100644
index 0000000..6ea951b
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_sysctl.c
@@ -0,0 +1,86 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <errno.h>
+#include <string.h>
+
+#include <nv.h>
+
+#include "libcapsicum.h"
+#include "libcapsicum_sysctl.h"
+
+int
+cap_sysctlbyname(cap_channel_t *chan, const char *name, void *oldp,
+    size_t *oldlenp, const void *newp, size_t newlen)
+{
+	nvlist_t *nvl;
+	const uint8_t *retoldp;
+	uint8_t operation;
+	size_t oldlen;
+
+	operation = 0;
+	if (oldp != NULL)
+		operation |= CAP_SYSCTL_READ;
+	if (newp != NULL)
+		operation |= CAP_SYSCTL_WRITE;
+
+	nvl = nvlist_create(0);
+	nvlist_add_string(nvl, "cmd", "sysctl");
+	nvlist_add_string(nvl, "name", name);
+	nvlist_add_number(nvl, "operation", (uint64_t)operation);
+	if (oldp == NULL && oldlenp != NULL)
+		nvlist_add_null(nvl, "justsize");
+	else if (oldlenp != NULL)
+		nvlist_add_number(nvl, "oldlen", (uint64_t)*oldlenp);
+	if (newp != NULL)
+		nvlist_add_binary(nvl, "newp", newp, newlen);
+	nvl = cap_xfer_nvlist(chan, nvl);
+	if (nvl == NULL)
+		return (-1);
+	if (nvlist_get_number(nvl, "error") != 0) {
+		errno = (int)nvlist_get_number(nvl, "error");
+		nvlist_destroy(nvl);
+		return (-1);
+	}
+
+	if (oldp == NULL && oldlenp != NULL) {
+		*oldlenp = (size_t)nvlist_get_number(nvl, "oldlen");
+	} else if (oldp != NULL) {
+		retoldp = nvlist_get_binary(nvl, "oldp", &oldlen);
+		memcpy(oldp, retoldp, oldlen);
+		if (oldlenp != NULL)
+			*oldlenp = oldlen;
+	}
+	nvlist_destroy(nvl);
+
+	return (0);
+}
diff --git a/lib/libcapsicum/libcapsicum_sysctl.h b/lib/libcapsicum/libcapsicum_sysctl.h
new file mode 100644
index 0000000..d0df143
--- /dev/null
+++ b/lib/libcapsicum/libcapsicum_sysctl.h
@@ -0,0 +1,43 @@
+/*-
+ * Copyright (c) 2013 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_LIBCAPSICUM_SYSCTL_H_
+#define	_LIBCAPSICUM_SYSCTL_H_
+
+#define	CAP_SYSCTL_READ		0x01
+#define	CAP_SYSCTL_WRITE	0x02
+#define	CAP_SYSCTL_RDWR		(CAP_SYSCTL_READ | CAP_SYSCTL_WRITE)
+#define	CAP_SYSCTL_RECURSIVE	0x04
+
+int cap_sysctlbyname(cap_channel_t *chan, const char *name, void *oldp,
+    size_t *oldlenp, const void *newp, size_t newlen);
+
+#endif	/* !_LIBCAPSICUM_SYSCTL_H_ */