Convert casperd(8) daemon to the libcasper.

After calling the cap_init(3) function Casper will fork from it's original
process, using pdfork(2). Forking from a process has a lot of advantages:
1. We have the same cwd as the original process.
2. The same uid, gid and groups.
3. The same MAC labels.
4. The same descriptor table.
5. The same routing table.
6. The same umask.
7. The same cpuset(1).
From now services are also in form of libraries.
We also removed libcapsicum at all and converts existing program using Casper
to new architecture.

Discussed with:		pjd, jonathan, ed, drysdale@google.com, emaste
Partially reviewed by:	drysdale@google.com, bdrewery
Approved by:		pjd (mentor)
Differential Revision:	https://reviews.freebsd.org/D4277

2 files changed, 20 insertions, 17 deletions

diff --git a/usr.bin/kdump/Makefile b/usr.bin/kdump/Makefile
index 40109f0..f80f668 100644
--- a/usr.bin/kdump/Makefile
+++ b/usr.bin/kdump/Makefile
@@ -11,8 +11,10 @@ CFLAGS+=	-I${.CURDIR}/../ktrace -I${.CURDIR} -I${.CURDIR}/../.. -I.
 
 LIBADD=		sysdecode
 .if ${MK_CASPER} != "no"
-LIBADD+=	capsicum
-CFLAGS+=-DHAVE_LIBCAPSICUM
+LIBADD+=	casper
+LIBADD+=	cap_grp
+LIBADD+=	cap_pwd
+CFLAGS+=-DHAVE_LIBCASPER
 .endif
 
 NO_WERROR?=	YES
diff --git a/usr.bin/kdump/kdump.c b/usr.bin/kdump/kdump.c
index 52001d2..e45a733 100644
--- a/usr.bin/kdump/kdump.c
+++ b/usr.bin/kdump/kdump.c
@@ -61,7 +61,7 @@ extern int errno;
 #include <sys/un.h>
 #include <sys/queue.h>
 #include <sys/wait.h>
-#ifdef HAVE_LIBCAPSICUM
+#ifdef HAVE_LIBCASPER
 #include <sys/nv.h>
 #endif
 #include <arpa/inet.h>
@@ -70,12 +70,6 @@ extern int errno;
 #include <err.h>
 #include <grp.h>
 #include <inttypes.h>
-#ifdef HAVE_LIBCAPSICUM
-#include <libcapsicum.h>
-#include <libcapsicum_grp.h>
-#include <libcapsicum_pwd.h>
-#include <libcapsicum_service.h>
-#endif
 #include <locale.h>
 #include <netdb.h>
 #include <nl_types.h>
@@ -91,6 +85,13 @@ extern int errno;
 #include "ktrace.h"
 #include "kdump_subr.h"
 
+#ifdef HAVE_LIBCASPER
+#include <libcasper.h>
+
+#include <casper/cap_grp.h>
+#include <casper/cap_pwd.h>
+#endif
+
 u_int abidump(struct ktr_header *);
 int fetchprocinfo(struct ktr_header *, u_int *);
 int fread_tail(void *, int, int);
@@ -151,7 +152,7 @@ struct proc_info
 
 static TAILQ_HEAD(trace_procs, proc_info) trace_procs;
 
-#ifdef HAVE_LIBCAPSICUM
+#ifdef HAVE_LIBCASPER
 static cap_channel_t *cappwd, *capgrp;
 #endif
 
@@ -180,7 +181,7 @@ localtime_init(void)
 	(void)localtime(&ltime);
 }
 
-#ifdef HAVE_LIBCAPSICUM
+#ifdef HAVE_LIBCASPER
 static int
 cappwdgrp_setup(cap_channel_t **cappwdp, cap_channel_t **capgrpp)
 {
@@ -189,8 +190,8 @@ cappwdgrp_setup(cap_channel_t **cappwdp, cap_channel_t **capgrpp)
 
 	capcas = cap_init();
 	if (capcas == NULL) {
-		warn("unable to contact casperd");
-		return (-1);
+		err(1, "unable to create casper process");
+		exit(1);
 	}
 	cappwdloc = cap_service_open(capcas, "system.pwd");
 	capgrploc = cap_service_open(capcas, "system.grp");
@@ -222,7 +223,7 @@ cappwdgrp_setup(cap_channel_t **cappwdp, cap_channel_t **capgrpp)
 	*capgrpp = capgrploc;
 	return (0);
 }
-#endif	/* HAVE_LIBCAPSICUM */
+#endif	/* HAVE_LIBCASPER */
 
 int
 main(int argc, char *argv[])
@@ -302,7 +303,7 @@ main(int argc, char *argv[])
 
 	strerror_init();
 	localtime_init();
-#ifdef HAVE_LIBCAPSICUM
+#ifdef HAVE_LIBCASPER
 	if (resolv != 0) {
 		if (cappwdgrp_setup(&cappwd, &capgrp) < 0) {
 			cappwd = NULL;
@@ -1648,7 +1649,7 @@ ktrstat(struct stat *statp)
 	if (resolv == 0) {
 		pwd = NULL;
 	} else {
-#ifdef HAVE_LIBCAPSICUM
+#ifdef HAVE_LIBCASPER
 		if (cappwd != NULL)
 			pwd = cap_getpwuid(cappwd, statp->st_uid);
 		else
@@ -1662,7 +1663,7 @@ ktrstat(struct stat *statp)
 	if (resolv == 0) {
 		grp = NULL;
 	} else {
-#ifdef HAVE_LIBCAPSICUM
+#ifdef HAVE_LIBCASPER
 		if (capgrp != NULL)
 			grp = cap_getgrgid(capgrp, statp->st_gid);
 		else