freebsd-dev/sys/kern/kern_proc.c
Poul-Henning Kamp a8704f8999 Add a sysctl to control if argv is disclosed to the world:
kern.ps_argsopen
It defaults to 1 which means that all users can see all argvs in ps(1).

Reviewed by:	Warner
1999-11-26 08:27:16 +00:00

688 lines
16 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>
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");
static void pgdelete __P((struct pgrp *));
/*
* Structure associated with user cacheing.
*/
struct uidinfo {
LIST_ENTRY(uidinfo) ui_hash;
uid_t ui_uid;
long ui_proccnt;
rlim_t ui_sbsize;
};
#define UIHASH(uid) (&uihashtbl[(uid) & uihash])
static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
static u_long uihash; /* size of hash table - 1 */
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;
vm_zone_t proc_zone;
/*
* Initialize global process hashing structures.
*/
void
procinit()
{
LIST_INIT(&allproc);
LIST_INIT(&zombproc);
pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
uihashtbl = hashinit(maxproc / 16, M_PROC, &uihash);
proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
}
/*
* Change the count associated with number of processes
* a given user is using.
*/
int
chgproccnt(uid, diff)
uid_t uid;
int diff;
{
register struct uidinfo *uip;
register struct uihashhead *uipp;
uipp = UIHASH(uid);
LIST_FOREACH(uip, uipp, ui_hash)
if (uip->ui_uid == uid)
break;
if (uip) {
uip->ui_proccnt += diff;
if (uip->ui_proccnt < 0)
panic("chgproccnt: procs < 0");
if (uip->ui_proccnt > 0 || uip->ui_sbsize > 0)
return (uip->ui_proccnt);
LIST_REMOVE(uip, ui_hash);
FREE(uip, M_PROC);
return (0);
}
if (diff <= 0) {
if (diff == 0)
return(0);
panic("chgproccnt: lost user");
}
MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
LIST_INSERT_HEAD(uipp, uip, ui_hash);
uip->ui_uid = uid;
uip->ui_proccnt = diff;
uip->ui_sbsize = 0;
return (diff);
}
/*
* Change the total socket buffer size a user has used.
*/
rlim_t
chgsbsize(uid, diff)
uid_t uid;
rlim_t diff;
{
register struct uidinfo *uip;
register struct uihashhead *uipp;
uipp = UIHASH(uid);
LIST_FOREACH(uip, uipp, ui_hash)
if (uip->ui_uid == uid)
break;
if (diff <= 0) {
if (diff == 0)
return (uip ? uip->ui_sbsize : 0);
KASSERT(uip != NULL, ("uidinfo (%d) gone", uid));
}
if (uip) {
uip->ui_sbsize += diff;
if (uip->ui_sbsize == 0 && uip->ui_proccnt == 0) {
LIST_REMOVE(uip, ui_hash);
FREE(uip, M_PROC);
return (0);
}
return (uip->ui_sbsize);
}
MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
LIST_INSERT_HEAD(uipp, uip, ui_hash);
uip->ui_uid = uid;
uip->ui_proccnt = 0;
uip->ui_sbsize = diff;
return (diff);
}
/*
* Is p an inferior of the current process?
*/
int
inferior(p)
register struct proc *p;
{
for (; p != curproc; p = p->p_pptr)
if (p->p_pid == 0)
return (0);
return (1);
}
/*
* Locate a process by number
*/
struct proc *
pfind(pid)
register pid_t pid;
{
register struct proc *p;
LIST_FOREACH(p, PIDHASH(pid), p_hash)
if (p->p_pid == pid)
return (p);
return (NULL);
}
/*
* 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.
*/
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);
}
}
/*
* 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 eproc structure for the specified process.
*/
void
fill_eproc(p, ep)
register struct proc *p;
register struct eproc *ep;
{
register struct tty *tp;
bzero(ep, sizeof(*ep));
ep->e_paddr = p;
if (p->p_cred) {
ep->e_pcred = *p->p_cred;
if (p->p_ucred)
ep->e_ucred = *p->p_ucred;
}
if (p->p_procsig) {
ep->e_procsig = *p->p_procsig;
}
if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
register struct vmspace *vm = p->p_vmspace;
ep->e_vm = *vm;
ep->e_vm.vm_rssize = vmspace_resident_count(vm); /*XXX*/
}
if ((p->p_flag & P_INMEM) && p->p_stats)
ep->e_stats = *p->p_stats;
if (p->p_pptr)
ep->e_ppid = p->p_pptr->p_pid;
if (p->p_pgrp) {
ep->e_pgid = p->p_pgrp->pg_id;
ep->e_jobc = p->p_pgrp->pg_jobc;
ep->e_sess = p->p_pgrp->pg_session;
if (ep->e_sess) {
bcopy(ep->e_sess->s_login, ep->e_login, sizeof(ep->e_login));
if (ep->e_sess->s_ttyvp)
ep->e_flag = EPROC_CTTY;
if (p->p_session && SESS_LEADER(p))
ep->e_flag |= EPROC_SLEADER;
}
}
if ((p->p_flag & P_CONTROLT) &&
(ep->e_sess != NULL) &&
((tp = ep->e_sess->s_ttyp) != NULL)) {
ep->e_tdev = dev2udev(tp->t_dev);
ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
ep->e_tsess = tp->t_session;
} else
ep->e_tdev = NOUDEV;
if (p->p_wmesg) {
strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
ep->e_wmesg[WMESGLEN] = 0;
}
}
static struct proc *
zpfind(pid_t pid)
{
struct proc *p;
LIST_FOREACH(p, &zombproc, p_list)
if (p->p_pid == pid)
return (p);
return (NULL);
}
static int
sysctl_out_proc(struct proc *p, struct sysctl_req *req, int doingzomb)
{
struct eproc eproc;
int error;
pid_t pid = p->p_pid;
fill_eproc(p, &eproc);
error = SYSCTL_OUT(req,(caddr_t)p, sizeof(struct proc));
if (error)
return (error);
error = SYSCTL_OUT(req,(caddr_t)&eproc, sizeof(eproc));
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 (!PRISON_CHECK(curproc, p))
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);
}
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)) {
/*
* 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 (!PRISON_CHECK(curproc, p))
continue;
error = sysctl_out_proc(p, req, doingzomb);
if (error)
return (error);
}
}
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_trespass(curproc, p))
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,
sysctl_kern_proc_args, "Return process argument");