xref: /illumos-gate/usr/src/uts/common/syscall/pgrpsys.c (revision 88f8b78a88cbdc6d8c1af5c3e54bc49d25095c98)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
23 /*	  All Rights Reserved	*/
24 
25 
26 #ident	"%Z%%M%	%I%	%E% SMI"	/* from SVr4.0 1.78 */
27 
28 #include <sys/param.h>
29 #include <sys/types.h>
30 #include <sys/sysmacros.h>
31 #include <sys/systm.h>
32 #include <sys/errno.h>
33 #include <sys/file.h>
34 #include <sys/proc.h>
35 #include <sys/session.h>
36 #include <sys/debug.h>
37 
38 /* ARGSUSED */
39 int
40 setpgrp(int flag, int pid, int pgid)
41 {
42 	register proc_t *p =  ttoproc(curthread);
43 	register int	retval = 0;
44 
45 	switch (flag) {
46 
47 	case 1: /* setpgrp() */
48 		mutex_enter(&pidlock);
49 		if (p->p_sessp->s_sidp != p->p_pidp && !pgmembers(p->p_pid)) {
50 			mutex_exit(&pidlock);
51 			sess_create();
52 		} else
53 			mutex_exit(&pidlock);
54 		return (p->p_sessp->s_sid);
55 
56 	case 3: /* setsid() */
57 		mutex_enter(&pidlock);
58 		if (p->p_pgidp == p->p_pidp || pgmembers(p->p_pid)) {
59 			mutex_exit(&pidlock);
60 			return (set_errno(EPERM));
61 		}
62 		mutex_exit(&pidlock);
63 		sess_create();
64 		return (p->p_sessp->s_sid);
65 
66 	case 5: /* setpgid() */
67 	{
68 		mutex_enter(&pidlock);
69 		if (pid == 0)
70 			pid = p->p_pid;
71 		else if (pid < 0 || pid >= maxpid) {
72 			mutex_exit(&pidlock);
73 			return (set_errno(EINVAL));
74 		} else if (pid != p->p_pid) {
75 			for (p = p->p_child; /* empty */; p = p->p_sibling) {
76 				if (p == NULL) {
77 					mutex_exit(&pidlock);
78 					return (set_errno(ESRCH));
79 				}
80 				if (p->p_pid == pid)
81 					break;
82 			}
83 			if (p->p_flag & SEXECED) {
84 				mutex_exit(&pidlock);
85 				return (set_errno(EACCES));
86 			}
87 			if (p->p_sessp != ttoproc(curthread)->p_sessp) {
88 				mutex_exit(&pidlock);
89 				return (set_errno(EPERM));
90 			}
91 		}
92 
93 		if (p->p_sessp->s_sid == pid) {
94 			mutex_exit(&pidlock);
95 			return (set_errno(EPERM));
96 		}
97 
98 		if (pgid == 0)
99 			pgid = p->p_pid;
100 		else if (pgid < 0 || pgid >= maxpid) {
101 			mutex_exit(&pidlock);
102 			return (set_errno(EINVAL));
103 		}
104 
105 		if (p->p_pgrp == pgid) {
106 			mutex_exit(&pidlock);
107 			break;
108 		} else if (p->p_pid == pgid) {
109 			/*
110 			 * We need to protect p_pgidp with p_lock because
111 			 * /proc looks at it while holding only p_lock.
112 			 */
113 			mutex_enter(&p->p_lock);
114 			pgexit(p);
115 			pgjoin(p, p->p_pidp);
116 			mutex_exit(&p->p_lock);
117 		} else {
118 			register proc_t *q;
119 
120 			if ((q = pgfind(pgid)) == NULL ||
121 			    q->p_sessp != p->p_sessp) {
122 				mutex_exit(&pidlock);
123 				return (set_errno(EPERM));
124 			}
125 			/*
126 			 * See comment above about p_lock and /proc
127 			 */
128 			mutex_enter(&p->p_lock);
129 			pgexit(p);
130 			pgjoin(p, q->p_pgidp);
131 			mutex_exit(&p->p_lock);
132 		}
133 		mutex_exit(&pidlock);
134 		break;
135 	}
136 
137 	case 0: /* getpgrp() */
138 		mutex_enter(&pidlock);
139 		retval = p->p_pgrp;
140 		mutex_exit(&pidlock);
141 		break;
142 
143 	case 2: /* getsid() */
144 	case 4: /* getpgid() */
145 		if (pid < 0 || pid >= maxpid) {
146 			return (set_errno(EINVAL));
147 		}
148 		mutex_enter(&pidlock);
149 		if (pid != 0 && p->p_pid != pid &&
150 		    ((p = prfind(pid)) == NULL || p->p_stat == SIDL)) {
151 			mutex_exit(&pidlock);
152 			return (set_errno(ESRCH));
153 		}
154 		if (flag == 2)
155 			retval = p->p_sessp->s_sid;
156 		else
157 			retval = p->p_pgrp;
158 		mutex_exit(&pidlock);
159 		break;
160 
161 	}
162 	return (retval);
163 }
164