Make -DNOSUID (or -DPPP_NOSUID) possible to build ppp without SUID

capabilities.

usr.sbin/ppp/Makefile

@@ -3,15 +3,19 @@
 PROG=	ppp
 SRCS=	acf.c arp.c async.c auth.c bundle.c cbcp.c ccp.c chap.c chat.c \
 	command.c datalink.c deflate.c defs.c exec.c filter.c fsm.c hdlc.c \
-	id.c iface.c ip.c ipcp.c iplist.c lcp.c link.c log.c lqr.c main.c \
+	iface.c ip.c ipcp.c iplist.c lcp.c link.c log.c lqr.c main.c \
 	mbuf.c mp.c pap.c physical.c pred.c probe.c prompt.c proto.c route.c \
 	server.c sig.c slcompress.c sync.c systems.c tcp.c throughput.c \
 	timer.c tty.c tun.c udp.c vjcomp.c
 CFLAGS+=-Wall
 LDADD+= -lcrypt -lmd -lutil -lz
 DPADD+=	${LIBCRYPT} ${LIBMD} ${LIBUTIL} ${LIBZ}
+.if defined(NOSUID) || defined(PPP_NOSUID)
+BINMODE=554
+.else
 BINMODE=4554
 BINOWN=	root
+.endif
 BINGRP=	network
 MAN8=	ppp.8
 
@@ -37,6 +41,14 @@ DPADD+= ${LIBALIAS}
 .endif
 .endif
 
+.if defined(NOSUID) || defined(PPP_NOSUID)
+CFLAGS+=-DNOSUID
+.else
+.if !defined(RELEASE_CRUNCH)
+SRCS+=	id.c
+.endif
+.endif
+
 .if exists(${.CURDIR}/../../secure) && !defined(NOCRYPT) && !defined(NOSECURE) && !defined(NO_OPENSSL) && !defined(RELEASE_CRUNCH)
 DISTRIBUTION=crypto
 CFLAGS+=-DHAVE_DES
@@ -72,9 +84,9 @@ DPADD+= ${LIBNETGRAPH}
 .if defined(RELEASE_CRUNCH)
 # We must create these objects because crunchgen will link them,
 # and we don't want any unused symbols to spoil the final link.
-CFLAGS+=-DNONAT -DNORADIUS -DNOI4B
-OBJS+=	chap_ms.o nat_cmd.o radius.o
-chap_ms.o nat_cmd.o radius.o:
+CFLAGS+=-DNONAT -DNORADIUS -DNOI4B -DNOSUID
+OBJS+=	chap_ms.o id.o nat_cmd.o radius.o
+chap_ms.o id.o nat_cmd.o radius.o:
 	>null_${.PREFIX}.c
 	cc -c -o ${.TARGET} null_${.PREFIX}.c
 .endif

usr.sbin/ppp/bundle.c

@@ -51,6 +51,9 @@
 #include <sys/uio.h>
 #include <sys/wait.h>
 #if defined(__FreeBSD__) && !defined(NOKLDLOAD)
+#ifdef NOSUID
+#include <sys/linker.h>
+#endif
 #include <sys/module.h>
 #endif
 #include <termios.h>
@@ -1852,7 +1855,9 @@ bundle_setsid(struct bundle *bundle, int holdsession)
         waitpid(pid, &status, 0);
         /* Tweak our process arguments.... */
         SetTitle("session owner");
+#ifndef NOSUID
         setuid(ID0realuid());
+#endif
         /*
          * Hang around for a HUP.  This should happen as soon as the
          * ppp that we passed our ctty descriptor to closes it.

usr.sbin/ppp/chap.c

@@ -254,7 +254,9 @@ chap_StartChild(struct chap *chap, char *prog, const char *name)
       }
       for (fd = getdtablesize(); fd > STDERR_FILENO; fd--)
         fcntl(fd, F_SETFD, 1);
+#ifndef NOSUID
       setuid(ID0realuid());
+#endif
       command_Expand(nargv, argc, (char const *const *)argv,
                      chap->auth.physical->dl->bundle, 0, pid);
       execvp(nargv[0], nargv);

usr.sbin/ppp/chat.c

@@ -733,7 +733,9 @@ ExecStr(struct physical *physical, char *command, char *out, int olen)
       open(_PATH_DEVNULL, O_RDWR);	/* Leave it closed if it fails... */
     for (i = getdtablesize(); i > 3; i--)
       fcntl(i, F_SETFD, 1);
+#ifndef NOSUID
     setuid(ID0realuid());
+#endif
     execvp(argv[0], argv);
     fprintf(stderr, "execvp: %s: %s\n", argv[0], strerror(errno));
     _exit(127);

usr.sbin/ppp/command.c

@@ -519,7 +519,9 @@ ShellCommand(struct cmdargs const *arg, int bg)
     for (i = getdtablesize(); i > STDERR_FILENO; i--)
       fcntl(i, F_SETFD, 1);
 
+#ifndef NOSUID
     setuid(ID0realuid());
+#endif
     if (arg->argc > arg->argn) {
       /* substitute pseudo args */
       char *argv[MAXARGS];

usr.sbin/ppp/exec.c

@@ -137,7 +137,9 @@ exec_Create(struct physical *p)
           close(pidpipe[0]);
           close(fids[0]);
           timer_TermService();
+#ifndef NOSUID
           setuid(ID0realuid());
+#endif
 
           child_status = 0;
           switch ((pid = vfork())) {

usr.sbin/ppp/id.h

@@ -26,6 +26,7 @@
  * $FreeBSD$
  */
 
+#ifndef NOSUID
 struct utmp;
 struct sockaddr_un;
 
@@ -51,3 +52,40 @@ extern int ID0kldload(const char *);
 #ifndef NONETGRAPH
 extern int ID0NgMkSockNode(const char *, int *, int *);
 #endif
+#else	/* NOSUID */
+#define ID0init()
+#define ID0realuid() (0)
+#define ID0ioctl ioctl
+#define ID0unlink unlink
+#define ID0socket socket
+#define ID0fopen fopen
+#define ID0open open
+#define ID0write write
+#define ID0uu_lock uu_lock
+#define ID0uu_lock_txfr uu_lock_txfr
+#define ID0uu_unlock uu_unlock
+#define ID0login(u)			\
+  do {					\
+    if (logout((u)->ut_line))		\
+      logwtmp((u)->ut_line, "", "");	\
+    login(u);				\
+  } while (0)
+#define ID0logout(dev, no)				\
+  do {							\
+    struct utmp ut;					\
+    strncpy(ut.ut_line, dev, sizeof ut.ut_line - 1);	\
+    ut.ut_line[sizeof ut.ut_line - 1] = '\0';		\
+    if (no || logout(ut.ut_line))			\
+      logwtmp(ut.ut_line, "", ""); 			\
+  } while (0)
+#define ID0bind_un(s, n) bind(s, (const struct sockaddr *)(n), sizeof *(n))
+#define ID0connect_un(s, n) \
+	connect(s, (const struct sockaddr *)(n), sizeof *(n))
+#define ID0kill kill
+#if defined(__FreeBSD__) && !defined(NOKLDLOAD)
+#define ID0kldload kldload
+#endif
+#ifndef NONETGRAPH
+#define ID0NgMkSockNode NgMkSockNode
+#endif
+#endif

usr.sbin/ppp/physical.c

@@ -29,6 +29,9 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <paths.h>
+#ifdef NOSUID
+#include <signal.h>
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>