summaryrefslogtreecommitdiff
path: root/src/misc/ioctl.c
blob: 492828119aeaa8583ed7dd72ab67f89507e8aa9c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
#include <sys/ioctl.h>
#include <stdarg.h>
#include <errno.h>
#include <time.h>
#include <sys/time.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include "syscall.h"

#define alignof(t) offsetof(struct { char c; t x; }, x)

#define W 1
#define R 2
#define WR 3

struct ioctl_compat_map {
	int new_req, old_req;
	unsigned char old_size, dir, force_align, noffs;
	unsigned char offsets[8];
};

#define NINTH(a,b,c,d,e,f,g,h,i,...) i
#define COUNT(...) NINTH(__VA_ARGS__,8,7,6,5,4,3,2,1,0)
#define OFFS(...) COUNT(__VA_ARGS__), { __VA_ARGS__ }

/* yields a type for a struct with original size n, with a misaligned
 * timeval/timespec expanded from 32- to 64-bit. for use with ioctl
 * number producing macros; only size of result is meaningful. */
#define new_misaligned(n) struct { int i; time_t t; char c[(n)-4]; }

struct v4l2_event {
	uint32_t a;
	uint64_t b[8];
	uint32_t c[2], ts[2], d[9];
};

static const struct ioctl_compat_map compat_map[] = {
	{ SIOCGSTAMP, SIOCGSTAMP_OLD, 8, R, 0, OFFS(0, 4) },
	{ SIOCGSTAMPNS, SIOCGSTAMPNS_OLD, 8, R, 0, OFFS(0, 4) },

	/* SNDRV_TIMER_IOCTL_STATUS */
	{ _IOR('T', 0x14, char[96]), _IOR('T', 0x14, 88), 88, R, 0, OFFS(0,4) },

	/* SNDRV_PCM_IOCTL_STATUS[_EXT] */
	{ _IOR('A', 0x20, char[128]), _IOR('A', 0x20, char[108]), 108, R, 1, OFFS(4,8,12,16,52,56,60,64) },
	{ _IOWR('A', 0x24, char[128]), _IOWR('A', 0x24, char[108]), 108, WR, 1, OFFS(4,8,12,16,52,56,60,64) },

	/* SNDRV_RAWMIDI_IOCTL_STATUS */
	{ _IOWR('W', 0x20, char[48]), _IOWR('W', 0x20, char[36]), 36, WR, 1, OFFS(4,8) },

	/* SNDRV_PCM_IOCTL_SYNC_PTR - with 3 subtables */
	{ _IOWR('A', 0x23, char[136]), _IOWR('A', 0x23, char[132]), 0, WR, 1, 0 },
	{ 0, 0, 4, WR, 1, 0 }, /* snd_pcm_sync_ptr (flags only) */
	{ 0, 0, 32, WR, 1, OFFS(8,12,16,24,28) }, /* snd_pcm_mmap_status */
	{ 0, 0, 8, WR, 1, OFFS(0,4) }, /* snd_pcm_mmap_control */

	/* VIDIOC_QUERYBUF, VIDIOC_QBUF, VIDIOC_DQBUF, VIDIOC_PREPARE_BUF */
	{ _IOWR('V',  9, new_misaligned(68)), _IOWR('V',  9, char[68]), 68, WR, 1, OFFS(20, 24) },
	{ _IOWR('V', 15, new_misaligned(68)), _IOWR('V', 15, char[68]), 68, WR, 1, OFFS(20, 24) },
	{ _IOWR('V', 17, new_misaligned(68)), _IOWR('V', 17, char[68]), 68, WR, 1, OFFS(20, 24) },
	{ _IOWR('V', 93, new_misaligned(68)), _IOWR('V', 93, char[68]), 68, WR, 1, OFFS(20, 24) },

	/* VIDIOC_DQEVENT */
	{ _IOR('V', 89, new_misaligned(120)), _IOR('V', 89, struct v4l2_event), sizeof(struct v4l2_event),
	  R, 0, OFFS(offsetof(struct v4l2_event, ts[0]), offsetof(struct v4l2_event, ts[1])) },

	/* VIDIOC_OMAP3ISP_STAT_REQ */
	{ _IOWR('V', 192+6, char[32]), _IOWR('V', 192+6, char[24]), 22, WR, 0, OFFS(0,4) },

	/* PPPIOCGIDLE */
	{ _IOR('t', 63, char[16]), _IOR('t', 63, char[8]), 8, R, 0, OFFS(0,4) },

	/* PPGETTIME, PPSETTIME */
	{ _IOR('p', 0x95, char[16]), _IOR('p', 0x95, char[8]), 8, R, 0, OFFS(0,4) },
	{ _IOW('p', 0x96, char[16]), _IOW('p', 0x96, char[8]), 8, W, 0, OFFS(0,4) },

	/* LPSETTIMEOUT */
	{ _IOW(0x6, 0xf, char[16]), 0x060f, 8, W, 0, OFFS(0,4) },
};

static void convert_ioctl_struct(const struct ioctl_compat_map *map, char *old, char *new, int dir)
{
	int new_offset = 0;
	int old_offset = 0;
	int old_size = map->old_size;
	if (!(dir & map->dir)) return;
	if (!map->old_size) {
		/* offsets hard-coded for SNDRV_PCM_IOCTL_SYNC_PTR;
		 * if another exception appears this needs changing. */
		convert_ioctl_struct(map+1, old, new, dir);
		convert_ioctl_struct(map+2, old+4, new+8, dir);
		convert_ioctl_struct(map+3, old+68, new+72, dir);
		return;
	}
	for (int i=0; i < map->noffs; i++) {
		int ts_offset = map->offsets[i];
		int len = ts_offset-old_offset;
		if (dir==W) memcpy(old+old_offset, new+new_offset, len);
		else memcpy(new+new_offset, old+old_offset, len);
		new_offset += len;
		old_offset += len;
		long long new_ts;
		long old_ts;
		int align = map->force_align ? sizeof(time_t) : alignof(time_t);
		new_offset += (align-1) & -new_offset;
		if (dir==W) {
			memcpy(&new_ts, new+new_offset, sizeof new_ts);
			old_ts = new_ts;
			memcpy(old+old_offset, &old_ts, sizeof old_ts);
		} else {
			memcpy(&old_ts, old+old_offset, sizeof old_ts);
			new_ts = old_ts;
			memcpy(new+new_offset, &new_ts, sizeof new_ts);
		}
		new_offset += sizeof new_ts;
		old_offset += sizeof old_ts;
	}
	if (dir==W) memcpy(old+old_offset, new+new_offset, old_size-old_offset);
	else memcpy(new+new_offset, old+old_offset, old_size-old_offset);
}

int ioctl(int fd, int req, ...)
{
	void *arg;
	va_list ap;
	va_start(ap, req);
	arg = va_arg(ap, void *);
	va_end(ap);
	int r = __syscall(SYS_ioctl, fd, req, arg);
	if (SIOCGSTAMP != SIOCGSTAMP_OLD && req && r==-ENOTTY) {
		for (int i=0; i<sizeof compat_map/sizeof *compat_map; i++) {
			if (compat_map[i].new_req != req) continue;
			union {
				long long align;
				char buf[256];
			} u;
			convert_ioctl_struct(&compat_map[i], u.buf, arg, W);
			r = __syscall(SYS_ioctl, fd, compat_map[i].old_req, u.buf);
			if (r<0) break;
			convert_ioctl_struct(&compat_map[i], u.buf, arg, R);
			break;
		}
	}
	return __syscall_ret(r);
}