Date: Sat, 27 Sep 1997 01:01:48 -0700 (PDT) From: Don Lewis <Don.Lewis@tsc.tdk.com> To: freebsd-hackers@freebsd.org Subject: F_SETOWN implementation redesign Message-ID: <199709270801.BAA00388@salsa.gv.tsc.tdk.com>
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After hearing about the OpenBSD security fix for F_SETOWN, I went digging
through the FreeBSD mail list archives and stumbled across a lot of
complaints about the current F_SETOWN implementation dating back to the
early part of 1996 (as well as mention of the security flaw). This inspired
me to revamp the F_SETOWN implementation to address some of these issues.
Security:
I added credential checking which should work in a similar manner
as the OpenBSD change.
I added a restriction that only allows F_SETOWN to specify a
process or process group in the same session as the caller.
This change is somewhat debatable, but I can't think of a good
use for allowing a process in another session to be specified
and there is some potential for misuse as well as traps for
the careless.
When a process exits or a process group loses all it's members,
any references to it specified by F_SETOWN are revoked even though
the device or socket has not been closed (it may be held open by
another process). The old implementation would start sending
signals to a new process once the process IDs wrapped around.
Funtionality:
The old implementation used TIOCSPGRP when used on a tty device.
This meant that you could only do async I/O on your controlling
tty, which meant that you were limited to doing async I/O on
at most one tty device. My new implementation separates the
F_SETOWN functionality from TIOCSPGRP on tty devices, so you
can do async I/O on multiple devices and still have a separate
control tty. The only restriction is that these tty devices
can't be the control ttys for another session.
The new implementation always returns an error if you specify
a non-existent process or process group.
Performance:
The old implemenation needed to search for the process group
or process whenever it wanted to deliver a signal. The new
implementation keeps a pointer, which should reduce the overhead
for heavy users of async I/O.
The attached patch is relative to my somewhat hacked copy of 2.1-stable,
so it might not apply quite cleanly to a fresh copy. It'll require even
more changes to make it work with 2.2 or later (for instance the
appropriate changes will need to be made to kern_pipe.c). I've only done
limited testing so far, but I thought this would be an appropriate time
to share my work.
One thing to consider is whether it is appropriate to remove the
TIOCSPGRP/TIOCGPGRP code from the non-tty drivers. I left it in in
case anyone is using these ioctl commands instead of F_SETOWN or
F_GETOWN on non-ttys. Removing this code would reduce the bloat
somewhat.
--- Truck
Index: lib/libc/sys/fcntl.2
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/lib/libc/sys/fcntl.2,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 fcntl.2
--- fcntl.2 1997/05/09 09:31:04 1.1.1.1
+++ fcntl.2 1997/09/27 01:35:13
@@ -477,29 +477,23 @@
.Dv F_SETLKW ,
and satisfying the lock or unlock request would result in the
number of locked regions in the system exceeding a system-imposed limit.
+.It Bq Er ENOTTY
+.Fa Cmd
+is
+.Dv F_GETOWN
+or
+.Dv F_SETOWN ,
+.Fa fd
+refers to a descriptor open on a terminal device (as opposed to a
+descriptor open on a socket), and the device is the controlling
+terminal for a session other than the session of the calling process.
.It Bq Er ESRCH
.Fa Cmd
is
.Dv F_SETOWN
and
-the process ID given as argument is not in use.
+the process ID or process group ID given as argument is not in use.
.El
-.Pp
-In addition, if
-.Fa fd
-refers to a descriptor open on a terminal device (as opposed to a
-descriptor open on a socket), a
-.Fa cmd
-of
-.Dv F_SETOWN
-can fail for the same reasons as in
-.Xr tcsetpgrp 3 ,
-and a
-.Fa cmd
-of
-.Dv F_GETOWN
-for the reasons as stated in
-.Xr tcgetpgrp 3 .
.Sh SEE ALSO
.Xr close 2 ,
.Xr execve 2 ,
@@ -507,8 +501,6 @@
.Xr getdtablesize 2 ,
.Xr open 2 ,
.Xr sigvec 2 ,
-.Xr tcgetpgrp 3 ,
-.Xr tcsetpgrp 3
.Sh HISTORY
The
.Nm
Index: sys/kern/kern_descrip.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/kern_descrip.c,v
retrieving revision 1.2
diff -u -r1.2 kern_descrip.c
--- kern_descrip.c 1997/05/13 11:55:43 1.2
+++ kern_descrip.c 1997/09/26 23:24:36
@@ -226,30 +226,13 @@
return (error);
case F_GETOWN:
- if (fp->f_type == DTYPE_SOCKET) {
- *retval = ((struct socket *)fp->f_data)->so_pgid;
- return (0);
- }
error = (*fp->f_ops->fo_ioctl)
- (fp, (int)TIOCGPGRP, (caddr_t)retval, p);
- *retval = -*retval;
+ (fp, (int)FIOGETOWN, (caddr_t)retval, p);
return (error);
case F_SETOWN:
- if (fp->f_type == DTYPE_SOCKET) {
- ((struct socket *)fp->f_data)->so_pgid = uap->arg;
- return (0);
- }
- if (uap->arg <= 0) {
- uap->arg = -uap->arg;
- } else {
- struct proc *p1 = pfind(uap->arg);
- if (p1 == 0)
- return (ESRCH);
- uap->arg = p1->p_pgrp->pg_id;
- }
return ((*fp->f_ops->fo_ioctl)
- (fp, (int)TIOCSPGRP, (caddr_t)&uap->arg, p));
+ (fp, (int)FIOSETOWN, (caddr_t)&uap->arg, p));
case F_SETLKW:
flg |= F_WAIT;
@@ -325,6 +308,94 @@
fdp->fd_lastfile = new;
*retval = new;
return (0);
+}
+
+/*
+ * If sigio is on the list associated with a process or process group,
+ * remove it.
+ */
+void
+funsetown(sigio)
+ register struct sigio *sigio;
+{
+ if (sigio->sio_pgid == 0)
+ return;
+
+ if (sigio->sio_pgid < 0) {
+ SLIST_REMOVE(&(sigio->sio_pgrp->pg_sigiolst), sigio, sigio,
+ sio_pgsigio);
+ sigio->sio_pgrp = NULL;
+ } else if (sigio->sio_pgid > 0) {
+ SLIST_REMOVE(&(sigio->sio_proc->p_sigiolst), sigio, sigio,
+ sio_pgsigio);
+ sigio->sio_proc = NULL;
+ }
+ sigio->sio_pgid = 0;
+ crfree(sigio->sio_ucred);
+ sigio->sio_ucred = NULL;
+}
+
+/*
+ * Common code for FIOSETOWN ioctl called by F_SETOWN
+ *
+ * After permission checking, add sigio structure to the sigio list for
+ * the process or process group.
+ */
+int
+fsetown(pgid, sigio, funset)
+ register pid_t pgid;
+ register struct sigio *sigio;
+ void (*funset) __P((struct sigio *));
+{
+ if (pgid == 0) {
+ funsetown(sigio);
+ return (0);
+ } else if (pgid > 0) {
+ register struct proc *proc = pfind(pgid);
+
+ if (proc == NULL)
+ return (ESRCH);
+ else if (proc->p_session != curproc->p_session)
+ return (EPERM);
+
+ funsetown(sigio);
+
+ SLIST_INSERT_HEAD(&(proc->p_sigiolst), sigio, sio_pgsigio);
+ sigio->sio_proc = proc;
+ } else /* if (pgid < 0) */ {
+ register struct pgrp *pgrp = pgfind(-pgid);
+
+ if (pgrp == NULL)
+ return (ESRCH);
+ else if (pgrp->pg_session != curproc->p_session)
+ return (EPERM);
+
+ funsetown(sigio);
+
+ SLIST_INSERT_HEAD(&(pgrp->pg_sigiolst), sigio, sio_pgsigio);
+ sigio->sio_pgrp = pgrp;
+ }
+
+ sigio->sio_pgid = pgid;
+
+ crhold(curproc->p_ucred);
+ sigio->sio_ucred = curproc->p_ucred;
+ sigio->sio_ruid = curproc->p_cred->p_ruid; /* wish this was in ucred */
+
+ sigio->sio_unsetown = funset;
+
+ return (0);
+}
+
+/*
+ * Common code for FIOGETOWN ioctl called by F_GETOWN
+ */
+pid_t
+fgetown(sigio)
+ register struct sigio *sigio;
+{
+ /* we could also return sigio->sio_{proc->p_pid,pgrp->pg_id} */
+ return (sigio->sio_pgid);
}
/*
Index: sys/kern/kern_exit.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/kern_exit.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 kern_exit.c
--- kern_exit.c 1997/05/09 09:34:33 1.1.1.1
+++ kern_exit.c 1997/09/26 23:25:32
@@ -131,6 +131,14 @@
untimeout(realitexpire, (caddr_t)p);
/*
+ * Reset any sigio structures pointing to us as a result of
+ * F_SETOWN with our pid
+ */
+ while (p->p_sigiolst.slh_first != NULL)
+ (*p->p_sigiolst.slh_first->sio_unsetown)
+ (p->p_sigiolst.slh_first);
+
+ /*
* Close open files and release open-file table.
* This may block!
*/
Index: sys/kern/kern_proc.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/kern_proc.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 kern_proc.c
--- kern_proc.c 1997/05/09 09:34:34 1.1.1.1
+++ kern_proc.c 1997/09/27 06:31:39
@@ -49,6 +49,7 @@
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/signalvar.h>
+#include <sys/filedesc.h>
struct prochd qs[NQS]; /* as good a place as any... */
struct prochd rtqs[NQS]; /* Space for REALTIME queues too */
@@ -246,6 +247,7 @@
pgrphash[n] = pgrp;
pgrp->pg_jobc = 0;
pgrp->pg_mem = NULL;
+ SLIST_INIT(&(pgrp->pg_sigiolst));
} else if (pgrp == p->p_pgrp)
return (0);
@@ -317,6 +319,14 @@
register struct pgrp *pgrp;
{
register struct pgrp **pgp = &pgrphash[PIDHASH(pgrp->pg_id)];
+
+ /*
+ * Reset any sigio structures pointing to us as a result of
+ * F_SETOWN with our pgid
+ */
+ while (pgrp->pg_sigiolst.slh_first != NULL)
+ (*pgrp->pg_sigiolst.slh_first->sio_unsetown)
+ (pgrp->pg_sigiolst.slh_first);
if (pgrp->pg_session->s_ttyp != NULL &&
pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
Index: sys/kern/kern_sig.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/kern_sig.c,v
retrieving revision 1.2
diff -u -r1.2 kern_sig.c
--- kern_sig.c 1997/05/13 11:58:02 1.2
+++ kern_sig.c 1997/09/26 13:02:08
@@ -93,6 +93,16 @@
((signum) == SIGCONT && (q)->p_session == (p)->p_session))
#endif
+/*
+ * Can real uid ruid with ucred uc send a signal to process q?
+ */
+#define CANSIGIO(ruid, uc, q) \
+ ((uc)->cr_uid == 0 || \
+ ruid == (q)->p_cred->p_ruid || \
+ (uc)->cr_uid == (q)->p_cred->p_ruid || \
+ ruid == (q)->p_ucred->cr_uid || \
+ (uc)->cr_uid == (q)->p_ucred->cr_uid)
+
struct sigaction_args {
int signum;
struct sigaction *nsa;
@@ -1241,4 +1251,27 @@
psignal(p, SIGSYS);
return (EINVAL);
+}
+
+/*
+ * Send a signal to a SIGIO or SIGURG to a process or process group using
+ * stored credentials rather than those of the current process
+ */
+void
+sigio_p_or_pg(sigio, signum, checkctty)
+ register struct sigio *sigio;
+ int signum, checkctty;
+{
+ if (sigio->sio_pgid > 0) {
+ if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
+ sigio->sio_proc))
+ psignal(sigio->sio_proc, signum);
+ } else if (sigio->sio_pgid < 0) {
+ register struct proc *p;
+
+ for (p = sigio->sio_pgrp->pg_mem; p != NULL; p = p->p_pgrpnxt)
+ if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
+ (checkctty == 0 || (p->p_flag & P_CONTROLT)))
+ psignal(p, signum);
+ }
}
Index: sys/kern/subr_log.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/subr_log.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 subr_log.c
--- subr_log.c 1997/05/09 09:34:34 1.1.1.1
+++ subr_log.c 1997/09/26 22:45:58
@@ -46,6 +46,7 @@
#include <sys/msgbuf.h>
#include <sys/file.h>
#include <sys/signalvar.h>
+#include <sys/filedesc.h> /* get fsetown, funsetown, fgetown */
#define LOG_RDPRI (PZERO + 1)
@@ -55,7 +56,8 @@
struct logsoftc {
int sc_state; /* see above for possibilities */
struct selinfo sc_selp; /* process waiting on select call */
- int sc_pgid; /* process/group for async I/O */
+ struct sigio sc_sigio; /* credentials and pointer to proc
+ * or group for SIGIO */
} logsoftc;
int log_open; /* also used in log() */
@@ -72,7 +74,8 @@
if (log_open)
return (EBUSY);
log_open = 1;
- logsoftc.sc_pgid = p->p_pid; /* signal process only */
+ /* signal process only */
+ fsetown(p->p_pid, &logsoftc.sc_sigio, funsetown);
return (0);
}
@@ -86,6 +89,7 @@
log_open = 0;
logsoftc.sc_state = 0;
+ funsetown(&logsoftc.sc_sigio);
return (0);
}
@@ -166,12 +170,8 @@
if (!log_open)
return;
selwakeup(&logsoftc.sc_selp);
- if (logsoftc.sc_state & LOG_ASYNC) {
- if (logsoftc.sc_pgid < 0)
- gsignal(-logsoftc.sc_pgid, SIGIO);
- else if ((p = pfind(logsoftc.sc_pgid)))
- psignal(p, SIGIO);
- }
+ if (logsoftc.sc_state & LOG_ASYNC)
+ sigio_p_or_pg(&(logsoftc.sc_sigio), SIGIO, 0);
if (logsoftc.sc_state & LOG_RDWAIT) {
wakeup((caddr_t)msgbufp);
logsoftc.sc_state &= ~LOG_RDWAIT;
@@ -188,7 +188,7 @@
struct proc *p;
{
long l;
- int s;
+ int s, error;
switch (com) {
@@ -212,12 +212,25 @@
logsoftc.sc_state &= ~LOG_ASYNC;
break;
+ case FIOSETOWN:
+ error = fsetown(*(int *)data, &(logsoftc.sc_sigio), funsetown);
+ if (error)
+ return (error);
+ break;
+
+ case FIOGETOWN:
+ *(int *)data = fgetown(&(logsoftc.sc_sigio));
+ break;
+
case TIOCSPGRP:
- logsoftc.sc_pgid = *(int *)data;
+ error = fsetown(-(*(int *)data), &(logsoftc.sc_sigio),
+ funsetown);
+ if (error)
+ return (error);
break;
case TIOCGPGRP:
- *(int *)data = logsoftc.sc_pgid;
+ *(int *)data = -fgetown(&(logsoftc.sc_sigio));
break;
default:
Index: sys/kern/sys_generic.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/sys_generic.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 sys_generic.c
--- sys_generic.c 1997/05/09 09:34:34 1.1.1.1
+++ sys_generic.c 1997/09/26 10:54:41
@@ -472,36 +472,8 @@
break;
case FIOSETOWN:
- tmp = *(int *)data;
- if (fp->f_type == DTYPE_SOCKET) {
- ((struct socket *)fp->f_data)->so_pgid = tmp;
- error = 0;
- break;
- }
- if (tmp <= 0) {
- tmp = -tmp;
- } else {
- struct proc *p1 = pfind(tmp);
- if (p1 == 0) {
- error = ESRCH;
- break;
- }
- tmp = p1->p_pgrp->pg_id;
- }
- error = (*fp->f_ops->fo_ioctl)
- (fp, (int)TIOCSPGRP, (caddr_t)&tmp, p);
- break;
-
case FIOGETOWN:
- if (fp->f_type == DTYPE_SOCKET) {
- error = 0;
- *(int *)data = ((struct socket *)fp->f_data)->so_pgid;
- break;
- }
- error = (*fp->f_ops->fo_ioctl)(fp, (int)TIOCGPGRP, data, p);
- *(int *)data = -*(int *)data;
- break;
-
+ /* fall through */
default:
error = (*fp->f_ops->fo_ioctl)(fp, com, data, p);
/*
Index: sys/kern/sys_socket.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/sys_socket.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 sys_socket.c
--- sys_socket.c 1997/05/09 09:34:35 1.1.1.1
+++ sys_socket.c 1997/09/26 23:14:42
@@ -76,6 +76,19 @@
uio, (struct mbuf *)0, (struct mbuf *)0, 0));
}
+/*
+ * Callback to undo FIOSETOWN on process or process group death
+ */
+void
+soo_unsetown(sigio)
+ struct sigio *sigio;
+{
+ register int s = splnet();
+
+ funsetown(sigio);
+ splx(s);
+}
+
int
soo_ioctl(fp, cmd, data, p)
struct file *fp;
@@ -84,6 +97,7 @@
struct proc *p;
{
register struct socket *so = (struct socket *)fp->f_data;
+ register int s, error;
switch (cmd) {
@@ -110,12 +124,28 @@
*(int *)data = so->so_rcv.sb_cc;
return (0);
- case SIOCSPGRP:
- so->so_pgid = *(int *)data;
+ case FIOSETOWN:
+ s = splnet();
+ error = fsetown(*(int *)data, &(so->so_sigio), soo_unsetown);
+ splx(s);
+ return(error);
+
+ case FIOGETOWN:
+ s = splnet();
+ *(int *)data = fgetown(&(so->so_sigio));
+ splx(s);
return (0);
+ case SIOCSPGRP:
+ s = splnet();
+ error = fsetown(-(*(int *)data), &(so->so_sigio), soo_unsetown);
+ splx(s);
+ return(error);
+
case SIOCGPGRP:
- *(int *)data = so->so_pgid;
+ s = splnet();
+ *(int *)data = -fgetown(&(so->so_sigio));
+ splx(s);
return (0);
case SIOCATMARK:
Index: sys/kern/tty.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/tty.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 tty.c
--- tty.c 1997/05/09 09:34:33 1.1.1.1
+++ tty.c 1997/09/26 23:28:11
@@ -86,6 +86,7 @@
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/malloc.h>
+#include <sys/filedesc.h> /* get fsetown, funsetown, fgetown */
#if NSNP > 0
#include <sys/snoop.h>
#endif
@@ -237,10 +238,13 @@
{
int s;
+
s = spltty();
if (constty == tp)
constty = NULL;
+ funsetown(&tp->t_sigio);
+
ttyflush(tp, FREAD | FWRITE);
clist_free_cblocks(&tp->t_canq);
clist_free_cblocks(&tp->t_outq);
@@ -690,6 +694,19 @@
}
/*
+ * Callback to undo FIOSETOWN on process or process group death
+ */
+void
+tty_unsetown(sigio)
+ struct sigio *sigio;
+{
+ register int s = spltty();
+
+ funsetown(sigio);
+ splx(s);
+}
+
+/*
* Ioctls for all tty devices. Called after line-discipline specific ioctl
* has been called to do discipline-specific functions and/or reject any
* of these ioctl commands.
@@ -758,6 +775,21 @@
*(int *)data = ttnread(tp);
splx(s);
break;
+ case FIOSETOWN:
+ if (tp->t_session != NULL && !isctty(p, tp))
+ return (ENOTTY);
+ s = spltty();
+ error = fsetown(*(int *)data, &(tp->t_sigio), tty_unsetown);
+ splx(s);
+ if (error)
+ return (error);
+ break;
+ case FIOGETOWN:
+ if (tp->t_session != NULL && !isctty(p, tp))
+ return (ENOTTY);
+ *(int *)data = fgetown(&(tp->t_sigio));
+ break;
+
case TIOCEXCL: /* set exclusive use of tty */
s = spltty();
SET(tp->t_state, TS_XCLUDE);
@@ -2077,7 +2109,7 @@
if (tp->t_rsel.si_pid != 0)
selwakeup(&tp->t_rsel);
if (ISSET(tp->t_state, TS_ASYNC))
- pgsignal(tp->t_pgrp, SIGIO, 1);
+ sigio_p_or_pg(&(tp->t_sigio), SIGIO, (tp->t_session != NULL));
wakeup(TSA_HUP_OR_INPUT(tp));
}
Index: sys/kern/uipc_socket.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/uipc_socket.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 uipc_socket.c
--- uipc_socket.c 1997/05/09 09:34:35 1.1.1.1
+++ uipc_socket.c 1997/09/26 11:43:25
@@ -166,6 +166,8 @@
int s = splnet(); /* conservative */
int error = 0;
+ funsetown(&(so->so_sigio));
+
if (so->so_options & SO_ACCEPTCONN) {
while (so->so_q0)
(void) soabort(so->so_q0);
@@ -1052,9 +1054,6 @@
{
struct proc *p;
- if (so->so_pgid < 0)
- gsignal(-so->so_pgid, SIGURG);
- else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0)
- psignal(p, SIGURG);
+ sigio_p_or_pg(&(so->so_sigio), SIGURG, 0);
selwakeup(&so->so_rcv.sb_sel);
}
Index: sys/kern/uipc_socket2.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/kern/uipc_socket2.c,v
retrieving revision 1.1.1.2
diff -u -r1.1.1.2 uipc_socket2.c
--- uipc_socket2.c 1997/05/10 08:30:30 1.1.1.2
+++ uipc_socket2.c 1997/09/26 22:50:38
@@ -177,7 +177,7 @@
so->so_state = head->so_state | SS_NOFDREF;
so->so_proto = head->so_proto;
so->so_timeo = head->so_timeo;
- so->so_pgid = head->so_pgid;
+ fsetown(fgetown(&(head->so_sigio)), &(so->so_sigio), soo_unsetown);
(void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat);
soqinsque(head, so, soqueue);
if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH,
@@ -328,10 +328,7 @@
wakeup((caddr_t)&sb->sb_cc);
}
if (so->so_state & SS_ASYNC) {
- if (so->so_pgid < 0)
- gsignal(-so->so_pgid, SIGIO);
- else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0)
- psignal(p, SIGIO);
+ sigio_p_or_pg(&(so->so_sigio), SIGIO, 0);
}
}
Index: sys/net/bpf.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/net/bpf.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 bpf.c
--- bpf.c 1997/05/09 09:34:44 1.1.1.1
+++ bpf.c 1997/09/27 00:11:57
@@ -59,6 +59,7 @@
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/ioctl.h>
+#include <sys/filedesc.h> /* get fsetown, funsetown, fgetown */
#include <sys/file.h>
#if defined(sparc) && BSD < 199103
@@ -352,6 +353,7 @@
register int s;
s = splimp();
+ funsetown(&d->bd_sigio);
if (d->bd_bif)
bpf_detachd(d);
splx(s);
@@ -510,10 +512,7 @@
wakeup((caddr_t)d);
if (d->bd_async && d->bd_sig)
- if (d->bd_pgid > 0)
- gsignal (d->bd_pgid, d->bd_sig);
- else if (p = pfind (-d->bd_pgid))
- psignal (p, d->bd_sig);
+ sigio_p_or_pg(&(d->bd_sigio), d->bd_sig, 0);
#if BSD >= 199103
selwakeup(&d->bd_sel);
@@ -589,6 +588,19 @@
}
/*
+ * Callback to undo FIOSETOWN on process or process group death
+ */
+static void
+bpfunsetown(sigio)
+ struct sigio *sigio;
+{
+ register int s = splimp();
+
+ funsetown(sigio);
+ splx(s);
+}
+
+/*
* FIONREAD Check for read packet available.
* SIOCGIFADDR Get interface address - convenient hook to driver.
* BIOCGBLEN Get buffer len [for read()].
@@ -815,18 +827,28 @@
d->bd_async = *(int *)addr;
break;
-/* N.B. ioctl (FIOSETOWN) and fcntl (F_SETOWN) both end up doing the
- equivalent of a TIOCSPGRP and hence end up here. *However* TIOCSPGRP's arg
- is a process group if it's positive and a process id if it's negative. This
- is exactly the opposite of what the other two functions want! Therefore
- there is code in ioctl and fcntl to negate the arg before calling here. */
+ case FIOSETOWN:
+ s = splimp();
+ error = fsetown(*(int *)addr, &(d->bd_sigio), bpfunsetown);
+ splx(s);
+ break;
- case TIOCSPGRP: /* Process or group to send signals to */
- d->bd_pgid = *(int *)addr;
+ case FIOGETOWN:
+ s = splimp();
+ *(int *)addr = fgetown(&(d->bd_sigio));
+ splx(s);
+ break;
+
+ case TIOCSPGRP:
+ s = splimp();
+ error = fsetown(-(*(int *)addr), &(d->bd_sigio), bpfunsetown);
+ splx(s);
break;
case TIOCGPGRP:
- *(int *)addr = d->bd_pgid;
+ s = splimp();
+ *(int *)addr = -fgetown(&(d->bd_sigio));
+ splx(s);
break;
case BIOCSRSIG: /* Set receive signal */
Index: sys/net/bpfdesc.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/net/bpfdesc.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 bpfdesc.h
--- bpfdesc.h 1997/05/09 09:34:45 1.1.1.1
+++ bpfdesc.h 1997/09/26 14:06:51
@@ -44,6 +44,7 @@
#define _NET_BPFDESC_H_
#include <sys/select.h>
+#include <sys/proc.h> /* pick up sigio */
/*
* Descriptor associated with each open bpf file.
@@ -78,7 +79,8 @@
u_char bd_immediate; /* true to return on packet arrival */
int bd_async; /* non-zero if packet reception should generate signal */
int bd_sig; /* signal to send upon packet reception */
- pid_t bd_pgid; /* process or group id for signal */
+ struct sigio bd_sigio; /* credentials and pointer to proc
+ * or group for SIGIO */
#if BSD < 199103
u_char bd_selcoll; /* true if selects collide */
int bd_timedout;
Index: sys/net/if_tun.c
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/net/if_tun.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 if_tun.c
--- if_tun.c 1997/05/09 09:34:46 1.1.1.1
+++ if_tun.c 1997/09/27 00:18:39
@@ -30,6 +30,7 @@
#include <sys/select.h>
#include <sys/file.h>
#include <sys/signalvar.h>
+#include <sys/filedesc.h>
#ifdef __FreeBSD__
#include <sys/kernel.h>
#endif
@@ -194,7 +195,7 @@
}
splx(s);
}
- tp->tun_pgrp = 0;
+ funsetown(&tp->tun_sigio);
selwakeup(&tp->tun_rsel);
TUNDEBUG ("%s%d: closed\n", ifp->if_name, ifp->if_unit);
@@ -359,11 +360,8 @@
tp->tun_flags &= ~TUN_RWAIT;
wakeup((caddr_t)tp);
}
- if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) {
- if (tp->tun_pgrp > 0)
- gsignal(tp->tun_pgrp, SIGIO);
- else if (p = pfind(-tp->tun_pgrp))
- psignal(p, SIGIO);
+ if (tp->tun_flags & TUN_ASYNC) {
+ sigio_p_or_pg(&(tp->tun_sigio), SIGIO, 0);
}
selwakeup(&tp->tun_rsel);
return 0;
@@ -423,12 +421,20 @@
*(int *)data = 0;
splx(s);
break;
+ case FIOSETOWN:
+ return (fsetown(*(int *)data, &(tp->tun_sigio), funsetown));
+
+ case FIOGETOWN:
+ *(int *)data = fgetown(&(tp->tun_sigio));
+ return (0);
+
case TIOCSPGRP:
- tp->tun_pgrp = *(int *)data;
- break;
+ return (fsetown(-(*(int *)data), &(tp->tun_sigio), funsetown));
+
case TIOCGPGRP:
- *(int *)data = tp->tun_pgrp;
- break;
+ *(int *)data = -fgetown(&(tp->tun_sigio));
+ return (0);
+
default:
return (ENOTTY);
}
Index: sys/net/if_tun.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/net/if_tun.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 if_tun.h
--- if_tun.h 1997/05/09 09:34:46 1.1.1.1
+++ if_tun.h 1997/09/26 12:25:04
@@ -33,7 +33,8 @@
#define TUN_READY (TUN_OPEN | TUN_INITED | TUN_IASET)
struct ifnet tun_if; /* the interface */
- int tun_pgrp; /* the process group - if any */
+ struct sigio tun_sigio; /* credentials and pointer to proc
+ * or group for SIGIO */
struct selinfo tun_rsel; /* read select */
struct selinfo tun_wsel; /* write select (not used) */
#if NBPFILTER > 0
Index: sys/sys/filedesc.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/sys/filedesc.h,v
retrieving revision 1.2
diff -u -r1.2 filedesc.h
--- filedesc.h 1997/05/13 12:05:40 1.2
+++ filedesc.h 1997/09/26 22:39:20
@@ -96,6 +96,9 @@
/*
* Kernel global variables and routines.
*/
+void funsetown __P((struct sigio *));
+int fsetown __P((pid_t, struct sigio *, void (*) (struct sigio *) ));
+pid_t fgetown __P((struct sigio *));
int dupfdopen __P((struct filedesc *, int, int, int, int));
int fdalloc __P((struct proc *p, int want, int *result));
int fdavail __P((struct proc *p, int n));
Index: sys/sys/proc.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/sys/proc.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 proc.h
--- proc.h 1997/05/09 09:35:08 1.1.1.1
+++ proc.h 1997/09/26 22:37:25
@@ -46,6 +46,7 @@
#include <sys/rtprio.h> /* For struct rtprio. */
#include <sys/select.h> /* For struct selinfo. */
#include <sys/time.h> /* For structs itimerval, timeval. */
+#include <sys/queue.h> /* For SLIST_HEAD, SLIST_ENTRY. */
/*
* One structure allocated per session.
@@ -58,6 +59,8 @@
char s_login[MAXLOGNAME]; /* Setlogin() name. */
};
+SLIST_HEAD(sigiolst, sigio);
+
/*
* One structure allocated per process group.
*/
@@ -65,6 +68,7 @@
struct pgrp *pg_hforw; /* Forward link in hash bucket. */
struct proc *pg_mem; /* Pointer to pgrp members. */
struct session *pg_session; /* Pointer to session. */
+ struct sigiolst pg_sigiolst; /* List of sigio sources */
pid_t pg_id; /* Pgrp id. */
int pg_jobc; /* # procs qualifying pgrp for job control */
};
@@ -136,9 +140,11 @@
struct vnode *p_textvp; /* Vnode of executable. */
+ struct sigiolst p_sigiolst; /* List of sigio sources */
+
char p_lock; /* Process lock count. */
char p_pad2[3]; /* alignment */
- long p_spare[2]; /* Pad to 256, avoid shifting eproc. XXX */
+ long p_spare[1]; /* Pad to 256, avoid shifting eproc. XXX */
/* End area that is zeroed on creation. */
#define p_endzero p_startcopy
@@ -221,6 +227,24 @@
gid_t p_svgid; /* Saved effective group id. */
int p_refcnt; /* Number of references. */
};
+
+/*
+ *
+ */
+struct sigio {
+ struct ucred *sio_ucred; /* Current credentials. */
+ uid_t sio_ruid; /* Real user id. */
+ union {
+ struct proc *siu_proc; /* Process to receive SIGIO/SIGURG */
+ struct pgrp *siu_pgrp; /* Process group to receive ... */
+ } sio_u;
+ void (*sio_unsetown) __P((struct sigio *));
+ SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */
+ pid_t sio_pgid; /* pgid for signals */
+};
+#define sio_proc sio_u.siu_proc
+#define sio_pgrp sio_u.siu_pgrp
+
#ifdef KERNEL
/*
Index: sys/sys/signalvar.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/sys/signalvar.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 signalvar.h
--- signalvar.h 1997/05/09 09:35:09 1.1.1.1
+++ signalvar.h 1997/09/26 13:24:15
@@ -162,6 +162,7 @@
void sigexit __P((struct proc *, int));
void siginit __P((struct proc *p));
void trapsignal __P((struct proc *p, int sig, unsigned code));
+void sigio_p_or_pg __P((struct sigio *, int signum, int checkctty));
/*
* Machine-dependent functions:
Index: sys/sys/socketvar.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/sys/socketvar.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 socketvar.h
--- socketvar.h 1997/05/09 09:35:09 1.1.1.1
+++ socketvar.h 1997/09/26 22:52:13
@@ -40,6 +40,7 @@
#include <sys/stat.h> /* for struct stat */
#include <sys/filedesc.h> /* for struct filedesc */
#include <sys/select.h> /* for struct selinfo */
+#include <sys/proc.h> /* for struct sigio */
/*
* Kernel structure per socket.
@@ -73,7 +74,8 @@
short so_qlimit; /* max number queued connections */
short so_timeo; /* connection timeout */
u_short so_error; /* error affecting connection */
- pid_t so_pgid; /* pgid for signals */
+ struct sigio so_sigio; /* credentials and pointer to proc
+ * or group for SIGIO/SIGURG */
u_long so_oobmark; /* chars to oob mark */
/*
* Variables for socket buffering.
@@ -211,6 +213,7 @@
int soo_select __P((struct file *fp, int which, struct proc *p));
int soo_close __P((struct file *fp, struct proc *p));
int soo_stat __P((struct socket *, struct stat *));
+void soo_unsetown __P((struct sigio *));
/*
* From uipc_socket and friends
Index: sys/sys/tty.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/sys/tty.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 tty.h
--- tty.h 1997/05/09 09:35:10 1.1.1.1
+++ tty.h 1997/09/26 13:00:15
@@ -44,6 +44,7 @@
#include <sys/termios.h>
#include <sys/select.h> /* For struct selinfo. */
+#include <sys/proc.h> /* For struct sigio */
/*
* Clists are character lists, which is a variable length linked list
@@ -79,6 +80,8 @@
int t_timeout; /* Timeout for ttywait() */
struct pgrp *t_pgrp; /* Foreground process group. */
struct session *t_session; /* Enclosing session. */
+ struct sigio t_sigio; /* credentials and pointer to proc
+ * or group for SIGIO */
struct selinfo t_rsel; /* Tty read/oob select. */
struct selinfo t_wsel; /* Tty write select. */
struct termios t_termios; /* Termios state. */
Index: sys/sys/types.h
===================================================================
RCS file: /usr/cvs/repository/FreeBSD-2.1/sys/sys/types.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 types.h
--- types.h 1997/05/09 09:35:10 1.1.1.1
+++ types.h 1997/09/26 13:41:46
@@ -157,6 +157,7 @@
*/
struct proc;
struct pgrp;
+struct sigio;
struct ucred;
struct rusage;
struct file;
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