Stub for setpgid

This implements a near noop setpgid, unless the use is one equivalent
to setsid, in which case it will behave as such.

Also activates setpgrp, which is implemented in terms of setpgid.

Change-Id: I84411cb1957351aa1d3985623cd9e69bdf6f8d4c

include/unistd.h

@@ -133,9 +133,7 @@ ssize_t	 read(int, void *, size_t);
 #endif
 int	 rmdir(const char *);
 int	 setgid(gid_t);
-#if !defined(__minix)
 int	 setpgid(pid_t, pid_t);
-#endif /* !defined(__minix) */
 pid_t	 setsid(void);
 int	 setuid(uid_t);
 unsigned int	 sleep(unsigned int);
@@ -270,9 +268,9 @@ int	 lockf(int, int, off_t);
 ssize_t	 readlink(const char * __restrict, char * __restrict, size_t);
 #endif
 void	*sbrk(intptr_t);
-#if !defined(__minix)
 /* XXX prototype wrong! */
 int	 setpgrp(pid_t, pid_t);			/* obsoleted by setpgid() */
+#if !defined(__minix)
 int	 setregid(gid_t, gid_t);
 int	 setreuid(uid_t, uid_t);
 #endif /* !defined(__minix) */

lib/libc/compat-43/Makefile.inc

@@ -10,7 +10,7 @@
 .PATH: ${ARCHDIR}/compat-43 ${.CURDIR}/compat-43
 
 SRCS+=	creat.c getdtablesize.c \
-	killpg.c \
+	killpg.c setpgrp.c \
 
 .if !defined(AUDIT)
 SRCS+=	getwd.c

lib/libc/sys-minix/Makefile.inc

@@ -22,7 +22,7 @@ SRCS+= 	accept.c access.c adjtime.c bind.c brk.c sbrk.c m_closefrom.c getsid.c \
 	sync.c syscall.c sysuname.c truncate.c umask.c unlink.c write.c \
 	utimensat.c utimes.c futimes.c lutimes.c futimens.c \
 	_exit.c _ucontext.c environ.c __getcwd.c vfork.c sizeup.c init.c \
-	getrusage.c setrlimit.c
+	getrusage.c setrlimit.c setpgid.c
 
 # Minix specific syscalls / utils.
 SRCS+= cprofile.c sprofile.c stack_utils.c _mcontext.c

lib/libc/sys-minix/setpgid.c

@@ -0,0 +1,44 @@
+#include <sys/cdefs.h>
+#include <lib.h>
+#include "namespace.h"
+
+#include <string.h>
+
+#include <unistd.h>
+
+/*
+ * "Smart" stub for now. This requires job control to be properly implemented.
+ */
+int setpgid(pid_t pid, pid_t pgid)
+{
+	pid_t _pid, _pgid, sid, cpid;
+
+	_pid = pid;
+	_pgid = pgid;
+
+	/* Who are we? */
+	cpid = getpid();
+
+	/* if zero, means current process. */
+	if (_pid == 0) {
+		_pid = cpid;
+	}
+
+	/* if zero, means given pid. */
+	if (_pgid == 0) {
+		_pgid = _pid;
+	}
+
+	/* right now we only support the equivalent of setsid(), which is
+	 * setpgid(0,0) */
+	if ((_pid != cpid) || (_pgid != cpid)) {
+	    errno = EINVAL;
+	    return -1;
+	}
+
+	if (setsid() == cpid) {
+		return 0;
+	} else {
+		return -1;
+	}
+}