freebsd-skq/sys/kern/kern_proc.c
Robert Watson 91421ba234 o Move per-process jail pointer (p->pr_prison) to inside of the subject
credential structure, ucred (cr->cr_prison).
o Allow jail inheritence to be a function of credential inheritence.
o Abstract prison structure reference counting behind pr_hold() and
  pr_free(), invoked by the similarly named credential reference
  management functions, removing this code from per-ABI fork/exit code.
o Modify various jail() functions to use struct ucred arguments instead
  of struct proc arguments.
o Introduce jailed() function to determine if a credential is jailed,
  rather than directly checking pointers all over the place.
o Convert PRISON_CHECK() macro to prison_check() function.
o Move jail() function prototypes to jail.h.
o Emulate the P_JAILED flag in fill_kinfo_proc() and no longer set the
  flag in the process flags field itself.
o Eliminate that "const" qualifier from suser/p_can/etc to reflect
  mutex use.

Notes:

o Some further cleanup of the linux/jail code is still required.
o It's now possible to consider resolving some of the process vs
  credential based permission checking confusion in the socket code.
o Mutex protection of struct prison is still not present, and is
  required to protect the reference count plus some fields in the
  structure.

Reviewed by:	freebsd-arch
Obtained from:	TrustedBSD Project
2001-02-21 06:39:57 +00:00

701 lines
18 KiB
C

/*
* Copyright (c) 1982, 1986, 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)kern_proc.c 8.7 (Berkeley) 2/14/95
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/tty.h>
#include <sys/signalvar.h>
#include <vm/vm.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <sys/user.h>
#include <vm/vm_zone.h>
#include <sys/jail.h>
static MALLOC_DEFINE(M_PGRP, "pgrp", "process group header");
MALLOC_DEFINE(M_SESSION, "session", "session header");
static MALLOC_DEFINE(M_PROC, "proc", "Proc structures");
MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures");
int ps_showallprocs = 1;
SYSCTL_INT(_kern, OID_AUTO, ps_showallprocs, CTLFLAG_RW,
&ps_showallprocs, 0, "");
static void pgdelete __P((struct pgrp *));
static void orphanpg __P((struct pgrp *pg));
/*
* Other process lists
*/
struct pidhashhead *pidhashtbl;
u_long pidhash;
struct pgrphashhead *pgrphashtbl;
u_long pgrphash;
struct proclist allproc;
struct proclist zombproc;
struct lock allproc_lock;
struct lock proctree_lock;
vm_zone_t proc_zone;
vm_zone_t ithread_zone;
/*
* Initialize global process hashing structures.
*/
void
procinit()
{
lockinit(&allproc_lock, PZERO, "allproc", 0, 0);
lockinit(&proctree_lock, PZERO, "proctree", 0, 0);
LIST_INIT(&allproc);
LIST_INIT(&zombproc);
pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
uihashinit();
/*
* This should really be a compile time warning, but I do
* not know of any way to do that...
*/
if (sizeof(struct kinfo_proc) != KINFO_PROC_SIZE)
printf("WARNING: size of kinfo_proc (%ld) should be %d!!!\n",
(long)sizeof(struct kinfo_proc), KINFO_PROC_SIZE);
}
/*
* Is p an inferior of the current process?
*/
int
inferior(p)
register struct proc *p;
{
int rval = 1;
PROCTREE_LOCK(PT_SHARED);
for (; p != curproc; p = p->p_pptr)
if (p->p_pid == 0) {
rval = 0;
break;
}
PROCTREE_LOCK(PT_RELEASE);
return (rval);
}
/*
* Locate a process by number
*/
struct proc *
pfind(pid)
register pid_t pid;
{
register struct proc *p;
ALLPROC_LOCK(AP_SHARED);
LIST_FOREACH(p, PIDHASH(pid), p_hash)
if (p->p_pid == pid)
break;
ALLPROC_LOCK(AP_RELEASE);
return (p);
}
/*
* Locate a process group by number
*/
struct pgrp *
pgfind(pgid)
register pid_t pgid;
{
register struct pgrp *pgrp;
LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
if (pgrp->pg_id == pgid)
return (pgrp);
return (NULL);
}
/*
* Move p to a new or existing process group (and session)
*/
int
enterpgrp(p, pgid, mksess)
register struct proc *p;
pid_t pgid;
int mksess;
{
register struct pgrp *pgrp = pgfind(pgid);
KASSERT(pgrp == NULL || !mksess,
("enterpgrp: setsid into non-empty pgrp"));
KASSERT(!SESS_LEADER(p),
("enterpgrp: session leader attempted setpgrp"));
if (pgrp == NULL) {
pid_t savepid = p->p_pid;
struct proc *np;
/*
* new process group
*/
KASSERT(p->p_pid == pgid,
("enterpgrp: new pgrp and pid != pgid"));
MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
M_WAITOK);
if ((np = pfind(savepid)) == NULL || np != p)
return (ESRCH);
if (mksess) {
register struct session *sess;
/*
* new session
*/
MALLOC(sess, struct session *, sizeof(struct session),
M_SESSION, M_WAITOK);
sess->s_leader = p;
sess->s_sid = p->p_pid;
sess->s_count = 1;
sess->s_ttyvp = NULL;
sess->s_ttyp = NULL;
bcopy(p->p_session->s_login, sess->s_login,
sizeof(sess->s_login));
p->p_flag &= ~P_CONTROLT;
pgrp->pg_session = sess;
KASSERT(p == curproc,
("enterpgrp: mksession and p != curproc"));
} else {
pgrp->pg_session = p->p_session;
pgrp->pg_session->s_count++;
}
pgrp->pg_id = pgid;
LIST_INIT(&pgrp->pg_members);
LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
pgrp->pg_jobc = 0;
SLIST_INIT(&pgrp->pg_sigiolst);
} else if (pgrp == p->p_pgrp)
return (0);
/*
* Adjust eligibility of affected pgrps to participate in job control.
* Increment eligibility counts before decrementing, otherwise we
* could reach 0 spuriously during the first call.
*/
fixjobc(p, pgrp, 1);
fixjobc(p, p->p_pgrp, 0);
LIST_REMOVE(p, p_pglist);
if (LIST_EMPTY(&p->p_pgrp->pg_members))
pgdelete(p->p_pgrp);
p->p_pgrp = pgrp;
LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
return (0);
}
/*
* remove process from process group
*/
int
leavepgrp(p)
register struct proc *p;
{
LIST_REMOVE(p, p_pglist);
if (LIST_EMPTY(&p->p_pgrp->pg_members))
pgdelete(p->p_pgrp);
p->p_pgrp = 0;
return (0);
}
/*
* delete a process group
*/
static void
pgdelete(pgrp)
register struct pgrp *pgrp;
{
/*
* Reset any sigio structures pointing to us as a result of
* F_SETOWN with our pgid.
*/
funsetownlst(&pgrp->pg_sigiolst);
if (pgrp->pg_session->s_ttyp != NULL &&
pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
pgrp->pg_session->s_ttyp->t_pgrp = NULL;
LIST_REMOVE(pgrp, pg_hash);
if (--pgrp->pg_session->s_count == 0)
FREE(pgrp->pg_session, M_SESSION);
FREE(pgrp, M_PGRP);
}
/*
* Adjust pgrp jobc counters when specified process changes process group.
* We count the number of processes in each process group that "qualify"
* the group for terminal job control (those with a parent in a different
* process group of the same session). If that count reaches zero, the
* process group becomes orphaned. Check both the specified process'
* process group and that of its children.
* entering == 0 => p is leaving specified group.
* entering == 1 => p is entering specified group.
*/
void
fixjobc(p, pgrp, entering)
register struct proc *p;
register struct pgrp *pgrp;
int entering;
{
register struct pgrp *hispgrp;
register struct session *mysession = pgrp->pg_session;
/*
* Check p's parent to see whether p qualifies its own process
* group; if so, adjust count for p's process group.
*/
PROCTREE_LOCK(PT_SHARED);
if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
hispgrp->pg_session == mysession) {
if (entering)
pgrp->pg_jobc++;
else if (--pgrp->pg_jobc == 0)
orphanpg(pgrp);
}
/*
* Check this process' children to see whether they qualify
* their process groups; if so, adjust counts for children's
* process groups.
*/
LIST_FOREACH(p, &p->p_children, p_sibling)
if ((hispgrp = p->p_pgrp) != pgrp &&
hispgrp->pg_session == mysession &&
p->p_stat != SZOMB) {
if (entering)
hispgrp->pg_jobc++;
else if (--hispgrp->pg_jobc == 0)
orphanpg(hispgrp);
}
PROCTREE_LOCK(PT_RELEASE);
}
/*
* A process group has become orphaned;
* if there are any stopped processes in the group,
* hang-up all process in that group.
*/
static void
orphanpg(pg)
struct pgrp *pg;
{
register struct proc *p;
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
if (p->p_stat == SSTOP) {
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
psignal(p, SIGHUP);
psignal(p, SIGCONT);
}
return;
}
}
}
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
DB_SHOW_COMMAND(pgrpdump, pgrpdump)
{
register struct pgrp *pgrp;
register struct proc *p;
register int i;
for (i = 0; i <= pgrphash; i++) {
if (!LIST_EMPTY(&pgrphashtbl[i])) {
printf("\tindx %d\n", i);
LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
printf(
"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
(void *)pgrp, (long)pgrp->pg_id,
(void *)pgrp->pg_session,
pgrp->pg_session->s_count,
(void *)LIST_FIRST(&pgrp->pg_members));
LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
printf("\t\tpid %ld addr %p pgrp %p\n",
(long)p->p_pid, (void *)p,
(void *)p->p_pgrp);
}
}
}
}
}
#endif /* DDB */
/*
* Fill in an kinfo_proc structure for the specified process.
*/
void
fill_kinfo_proc(p, kp)
struct proc *p;
struct kinfo_proc *kp;
{
struct tty *tp;
struct session *sp;
bzero(kp, sizeof(*kp));
kp->ki_structsize = sizeof(*kp);
kp->ki_paddr = p;
PROC_LOCK(p);
kp->ki_addr = p->p_addr;
kp->ki_args = p->p_args;
kp->ki_tracep = p->p_tracep;
kp->ki_textvp = p->p_textvp;
kp->ki_fd = p->p_fd;
kp->ki_vmspace = p->p_vmspace;
if (p->p_cred) {
kp->ki_uid = p->p_cred->pc_ucred->cr_uid;
kp->ki_ruid = p->p_cred->p_ruid;
kp->ki_svuid = p->p_cred->p_svuid;
kp->ki_ngroups = p->p_cred->pc_ucred->cr_ngroups;
bcopy(p->p_cred->pc_ucred->cr_groups, kp->ki_groups,
NGROUPS * sizeof(gid_t));
kp->ki_rgid = p->p_cred->p_rgid;
kp->ki_svgid = p->p_cred->p_svgid;
}
if (p->p_procsig) {
kp->ki_sigignore = p->p_procsig->ps_sigignore;
kp->ki_sigcatch = p->p_procsig->ps_sigcatch;
}
mtx_lock_spin(&sched_lock);
if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
struct vmspace *vm = p->p_vmspace;
kp->ki_size = vm->vm_map.size;
kp->ki_rssize = vmspace_resident_count(vm); /*XXX*/
kp->ki_swrss = vm->vm_swrss;
kp->ki_tsize = vm->vm_tsize;
kp->ki_dsize = vm->vm_dsize;
kp->ki_ssize = vm->vm_ssize;
}
if ((p->p_sflag & PS_INMEM) && p->p_stats) {
kp->ki_start = p->p_stats->p_start;
kp->ki_rusage = p->p_stats->p_ru;
kp->ki_childtime.tv_sec = p->p_stats->p_cru.ru_utime.tv_sec +
p->p_stats->p_cru.ru_stime.tv_sec;
kp->ki_childtime.tv_usec = p->p_stats->p_cru.ru_utime.tv_usec +
p->p_stats->p_cru.ru_stime.tv_usec;
}
if (p->p_wmesg) {
strncpy(kp->ki_wmesg, p->p_wmesg, WMESGLEN);
kp->ki_wmesg[WMESGLEN] = 0;
}
if (p->p_stat == SMTX) {
kp->ki_kiflag |= KI_MTXBLOCK;
strncpy(kp->ki_mtxname, p->p_mtxname, MTXNAMELEN);
kp->ki_mtxname[MTXNAMELEN] = 0;
}
kp->ki_stat = p->p_stat;
kp->ki_sflag = p->p_sflag;
kp->ki_pctcpu = p->p_pctcpu;
kp->ki_estcpu = p->p_estcpu;
kp->ki_slptime = p->p_slptime;
kp->ki_swtime = p->p_swtime;
kp->ki_wchan = p->p_wchan;
kp->ki_traceflag = p->p_traceflag;
kp->ki_pri = p->p_pri;
kp->ki_nice = p->p_nice;
kp->ki_runtime = p->p_runtime;
kp->ki_pid = p->p_pid;
kp->ki_rqindex = p->p_rqindex;
kp->ki_oncpu = p->p_oncpu;
kp->ki_lastcpu = p->p_lastcpu;
mtx_unlock_spin(&sched_lock);
sp = NULL;
if (p->p_pgrp) {
kp->ki_pgid = p->p_pgrp->pg_id;
kp->ki_jobc = p->p_pgrp->pg_jobc;
sp = p->p_pgrp->pg_session;
if (sp != NULL) {
kp->ki_sid = sp->s_sid;
bcopy(sp->s_login, kp->ki_login, sizeof(kp->ki_login));
if (sp->s_ttyvp)
kp->ki_kiflag = KI_CTTY;
if (SESS_LEADER(p))
kp->ki_kiflag |= KI_SLEADER;
}
}
if ((p->p_flag & P_CONTROLT) && sp && ((tp = sp->s_ttyp) != NULL)) {
kp->ki_tdev = dev2udev(tp->t_dev);
kp->ki_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
if (tp->t_session)
kp->ki_tsid = tp->t_session->s_sid;
} else
kp->ki_tdev = NOUDEV;
if (p->p_comm[0] != 0) {
strncpy(kp->ki_comm, p->p_comm, MAXCOMLEN);
kp->ki_comm[MAXCOMLEN] = 0;
}
kp->ki_siglist = p->p_siglist;
kp->ki_sigmask = p->p_sigmask;
kp->ki_xstat = p->p_xstat;
kp->ki_acflag = p->p_acflag;
kp->ki_flag = p->p_flag;
/* If jailed(p->p_ucred), emulate the old P_JAILED flag. */
if (jailed(p->p_ucred))
kp->ki_flag |= P_JAILED;
kp->ki_lock = p->p_lock;
PROC_UNLOCK(p);
PROCTREE_LOCK(PT_SHARED);
if (p->p_pptr)
kp->ki_ppid = p->p_pptr->p_pid;
PROCTREE_LOCK(PT_RELEASE);
}
/*
* Locate a zombie process by number
*/
struct proc *
zpfind(pid_t pid)
{
struct proc *p;
ALLPROC_LOCK(AP_SHARED);
LIST_FOREACH(p, &zombproc, p_list)
if (p->p_pid == pid)
break;
ALLPROC_LOCK(AP_RELEASE);
return (p);
}
static int
sysctl_out_proc(struct proc *p, struct sysctl_req *req, int doingzomb)
{
struct kinfo_proc kinfo_proc;
int error;
pid_t pid = p->p_pid;
fill_kinfo_proc(p, &kinfo_proc);
error = SYSCTL_OUT(req, (caddr_t)&kinfo_proc, sizeof(kinfo_proc));
if (error)
return (error);
if (!doingzomb && pid && (pfind(pid) != p))
return EAGAIN;
if (doingzomb && zpfind(pid) != p)
return EAGAIN;
return (0);
}
static int
sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
{
int *name = (int*) arg1;
u_int namelen = arg2;
struct proc *p;
int doingzomb;
int error = 0;
if (oidp->oid_number == KERN_PROC_PID) {
if (namelen != 1)
return (EINVAL);
p = pfind((pid_t)name[0]);
if (!p)
return (0);
if (p_can(curproc, p, P_CAN_SEE, NULL))
return (0);
error = sysctl_out_proc(p, req, 0);
return (error);
}
if (oidp->oid_number == KERN_PROC_ALL && !namelen)
;
else if (oidp->oid_number != KERN_PROC_ALL && namelen == 1)
;
else
return (EINVAL);
if (!req->oldptr) {
/* overestimate by 5 procs */
error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
if (error)
return (error);
}
ALLPROC_LOCK(AP_SHARED);
for (doingzomb=0 ; doingzomb < 2 ; doingzomb++) {
if (!doingzomb)
p = LIST_FIRST(&allproc);
else
p = LIST_FIRST(&zombproc);
for (; p != 0; p = LIST_NEXT(p, p_list)) {
/*
* Show a user only appropriate processes.
*/
if (p_can(curproc, p, P_CAN_SEE, NULL))
continue;
/*
* Skip embryonic processes.
*/
if (p->p_stat == SIDL)
continue;
/*
* TODO - make more efficient (see notes below).
* do by session.
*/
switch (oidp->oid_number) {
case KERN_PROC_PGRP:
/* could do this by traversing pgrp */
if (p->p_pgrp == NULL ||
p->p_pgrp->pg_id != (pid_t)name[0])
continue;
break;
case KERN_PROC_TTY:
if ((p->p_flag & P_CONTROLT) == 0 ||
p->p_session == NULL ||
p->p_session->s_ttyp == NULL ||
dev2udev(p->p_session->s_ttyp->t_dev) !=
(udev_t)name[0])
continue;
break;
case KERN_PROC_UID:
if (p->p_ucred == NULL ||
p->p_ucred->cr_uid != (uid_t)name[0])
continue;
break;
case KERN_PROC_RUID:
if (p->p_ucred == NULL ||
p->p_cred->p_ruid != (uid_t)name[0])
continue;
break;
}
if (p_can(curproc, p, P_CAN_SEE, NULL))
continue;
error = sysctl_out_proc(p, req, doingzomb);
if (error) {
ALLPROC_LOCK(AP_RELEASE);
return (error);
}
}
}
ALLPROC_LOCK(AP_RELEASE);
return (0);
}
/*
* This sysctl allows a process to retrieve the argument list or process
* title for another process without groping around in the address space
* of the other process. It also allow a process to set its own "process
* title to a string of its own choice.
*/
static int
sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
{
int *name = (int*) arg1;
u_int namelen = arg2;
struct proc *p;
struct pargs *pa;
int error = 0;
if (namelen != 1)
return (EINVAL);
p = pfind((pid_t)name[0]);
if (!p)
return (0);
if ((!ps_argsopen) && p_can(curproc, p, P_CAN_SEE, NULL))
return (0);
if (req->newptr && curproc != p)
return (EPERM);
if (req->oldptr && p->p_args != NULL)
error = SYSCTL_OUT(req, p->p_args->ar_args, p->p_args->ar_length);
if (req->newptr == NULL)
return (error);
if (p->p_args && --p->p_args->ar_ref == 0)
FREE(p->p_args, M_PARGS);
p->p_args = NULL;
if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
return (error);
MALLOC(pa, struct pargs *, sizeof(struct pargs) + req->newlen,
M_PARGS, M_WAITOK);
pa->ar_ref = 1;
pa->ar_length = req->newlen;
error = SYSCTL_IN(req, pa->ar_args, req->newlen);
if (!error)
p->p_args = pa;
else
FREE(pa, M_PARGS);
return (error);
}
SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD, 0, "Process table");
SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
0, 0, sysctl_kern_proc, "S,proc", "Return entire process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
sysctl_kern_proc, "Process table");
SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW | CTLFLAG_ANYBODY,
sysctl_kern_proc_args, "Process argument list");