1// SPDX-License-Identifier: GPL-2.0
2/*
3 * sys_ipc() is the old de-multiplexer for the SysV IPC calls.
4 *
5 * This is really horribly ugly, and new architectures should just wire up
6 * the individual syscalls instead.
7 */
8#include <linux/unistd.h>
9#include <linux/syscalls.h>
10#include <linux/security.h>
11#include <linux/ipc_namespace.h>
12#include "util.h"
13
14#ifdef __ARCH_WANT_SYS_IPC
15#include <linux/errno.h>
16#include <linux/ipc.h>
17#include <linux/shm.h>
18#include <linux/uaccess.h>
19
20int ksys_ipc(unsigned int call, int first, unsigned long second,
21	unsigned long third, void __user * ptr, long fifth)
22{
23	int version, ret;
24
25	version = call >> 16; /* hack for backward compatibility */
26	call &= 0xffff;
27
28	switch (call) {
29	case SEMOP:
30		return ksys_semtimedop(first, (struct sembuf __user *)ptr,
31				       second, NULL);
32	case SEMTIMEDOP:
33		if (IS_ENABLED(CONFIG_64BIT))
34			return ksys_semtimedop(first, ptr, second,
35			        (const struct __kernel_timespec __user *)fifth);
36		else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
37			return compat_ksys_semtimedop(first, ptr, second,
38			        (const struct old_timespec32 __user *)fifth);
39		else
40			return -ENOSYS;
41
42	case SEMGET:
43		return ksys_semget(first, second, third);
44	case SEMCTL: {
45		unsigned long arg;
46		if (!ptr)
47			return -EINVAL;
48		if (get_user(arg, (unsigned long __user *) ptr))
49			return -EFAULT;
50		return ksys_old_semctl(first, second, third, arg);
51	}
52
53	case MSGSND:
54		return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
55				  second, third);
56	case MSGRCV:
57		switch (version) {
58		case 0: {
59			struct ipc_kludge tmp;
60			if (!ptr)
61				return -EINVAL;
62
63			if (copy_from_user(&tmp,
64					   (struct ipc_kludge __user *) ptr,
65					   sizeof(tmp)))
66				return -EFAULT;
67			return ksys_msgrcv(first, tmp.msgp, second,
68					   tmp.msgtyp, third);
69		}
70		default:
71			return ksys_msgrcv(first,
72					   (struct msgbuf __user *) ptr,
73					   second, fifth, third);
74		}
75	case MSGGET:
76		return ksys_msgget((key_t) first, second);
77	case MSGCTL:
78		return ksys_old_msgctl(first, second,
79				   (struct msqid_ds __user *)ptr);
80
81	case SHMAT:
82		switch (version) {
83		default: {
84			unsigned long raddr;
85			ret = do_shmat(first, (char __user *)ptr,
86				       second, &raddr, SHMLBA);
87			if (ret)
88				return ret;
89			return put_user(raddr, (unsigned long __user *) third);
90		}
91		case 1:
92			/*
93			 * This was the entry point for kernel-originating calls
94			 * from iBCS2 in 2.2 days.
95			 */
96			return -EINVAL;
97		}
98	case SHMDT:
99		return ksys_shmdt((char __user *)ptr);
100	case SHMGET:
101		return ksys_shmget(first, second, third);
102	case SHMCTL:
103		return ksys_old_shmctl(first, second,
104				   (struct shmid_ds __user *) ptr);
105	default:
106		return -ENOSYS;
107	}
108}
109
110SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
111		unsigned long, third, void __user *, ptr, long, fifth)
112{
113	return ksys_ipc(call, first, second, third, ptr, fifth);
114}
115#endif
116
117#ifdef CONFIG_COMPAT
118#include <linux/compat.h>
119
120#ifndef COMPAT_SHMLBA
121#define COMPAT_SHMLBA	SHMLBA
122#endif
123
124struct compat_ipc_kludge {
125	compat_uptr_t msgp;
126	compat_long_t msgtyp;
127};
128
129#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
130int compat_ksys_ipc(u32 call, int first, int second,
131	u32 third, compat_uptr_t ptr, u32 fifth)
132{
133	int version;
134	u32 pad;
135
136	version = call >> 16; /* hack for backward compatibility */
137	call &= 0xffff;
138
139	switch (call) {
140	case SEMOP:
141		/* struct sembuf is the same on 32 and 64bit :)) */
142		return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
143	case SEMTIMEDOP:
144		if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
145			return -ENOSYS;
146		return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
147						compat_ptr(fifth));
148	case SEMGET:
149		return ksys_semget(first, second, third);
150	case SEMCTL:
151		if (!ptr)
152			return -EINVAL;
153		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
154			return -EFAULT;
155		return compat_ksys_old_semctl(first, second, third, pad);
156
157	case MSGSND:
158		return compat_ksys_msgsnd(first, ptr, second, third);
159
160	case MSGRCV: {
161		void __user *uptr = compat_ptr(ptr);
162
163		if (first < 0 || second < 0)
164			return -EINVAL;
165
166		if (!version) {
167			struct compat_ipc_kludge ipck;
168			if (!uptr)
169				return -EINVAL;
170			if (copy_from_user(&ipck, uptr, sizeof(ipck)))
171				return -EFAULT;
172			return compat_ksys_msgrcv(first, ipck.msgp, second,
173						 ipck.msgtyp, third);
174		}
175		return compat_ksys_msgrcv(first, ptr, second, fifth, third);
176	}
177	case MSGGET:
178		return ksys_msgget(first, second);
179	case MSGCTL:
180		return compat_ksys_old_msgctl(first, second, compat_ptr(ptr));
181
182	case SHMAT: {
183		int err;
184		unsigned long raddr;
185
186		if (version == 1)
187			return -EINVAL;
188		err = do_shmat(first, compat_ptr(ptr), second, &raddr,
189			       COMPAT_SHMLBA);
190		if (err < 0)
191			return err;
192		return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
193	}
194	case SHMDT:
195		return ksys_shmdt(compat_ptr(ptr));
196	case SHMGET:
197		return ksys_shmget(first, (unsigned int)second, third);
198	case SHMCTL:
199		return compat_ksys_old_shmctl(first, second, compat_ptr(ptr));
200	}
201
202	return -ENOSYS;
203}
204
205COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
206	u32, third, compat_uptr_t, ptr, u32, fifth)
207{
208	return compat_ksys_ipc(call, first, second, third, ptr, fifth);
209}
210#endif
211#endif
212