ioctl.c raw
1 #include <sys/ioctl.h>
2 #include <stdarg.h>
3 #include <errno.h>
4 #include <time.h>
5 #include <sys/time.h>
6 #include <stddef.h>
7 #include <stdint.h>
8 #include <string.h>
9 #include <endian.h>
10 #include "syscall.h"
11
12 #define alignof(t) offsetof(struct { char c; t x; }, x)
13
14 #define W 1
15 #define R 2
16 #define WR 3
17
18 struct ioctl_compat_map {
19 int new_req, old_req;
20 unsigned char old_size, dir, force_align, noffs;
21 unsigned char offsets[8];
22 };
23
24 #define NINTH(a,b,c,d,e,f,g,h,i,...) i
25 #define COUNT(...) NINTH(__VA_ARGS__,8,7,6,5,4,3,2,1,0)
26 #define OFFS(...) COUNT(__VA_ARGS__), { __VA_ARGS__ }
27
28 /* yields a type for a struct with original size n, with a misaligned
29 * timeval/timespec expanded from 32- to 64-bit. for use with ioctl
30 * number producing macros; only size of result is meaningful. */
31 #define new_misaligned(n) struct { int i; time_t t; char c[(n)-4]; }
32
33 struct v4l2_event {
34 uint32_t a;
35 uint64_t b[8];
36 uint32_t c[2], ts[2], d[9];
37 };
38
39 static const struct ioctl_compat_map compat_map[] = {
40 { SIOCGSTAMP, SIOCGSTAMP_OLD, 8, R, 0, OFFS(0, 4) },
41 { SIOCGSTAMPNS, SIOCGSTAMPNS_OLD, 8, R, 0, OFFS(0, 4) },
42
43 /* SNDRV_TIMER_IOCTL_STATUS */
44 { _IOR('T', 0x14, char[96]), _IOR('T', 0x14, 88), 88, R, 0, OFFS(0,4) },
45
46 /* SNDRV_PCM_IOCTL_STATUS[_EXT] */
47 { _IOR('A', 0x20, char[128]), _IOR('A', 0x20, char[108]), 108, R, 1, OFFS(4,8,12,16,52,56,60,64) },
48 { _IOWR('A', 0x24, char[128]), _IOWR('A', 0x24, char[108]), 108, WR, 1, OFFS(4,8,12,16,52,56,60,64) },
49
50 /* SNDRV_RAWMIDI_IOCTL_STATUS */
51 { _IOWR('W', 0x20, char[48]), _IOWR('W', 0x20, char[36]), 36, WR, 1, OFFS(4,8) },
52
53 /* SNDRV_PCM_IOCTL_SYNC_PTR - with 3 subtables */
54 { _IOWR('A', 0x23, char[136]), _IOWR('A', 0x23, char[132]), 0, WR, 1, 0 },
55 { 0, 0, 4, WR, 1, 0 }, /* snd_pcm_sync_ptr (flags only) */
56 { 0, 0, 32, WR, 1, OFFS(8,12,16,24,28) }, /* snd_pcm_mmap_status */
57 { 0, 0, 4, WR, 1, 0 }, /* snd_pcm_mmap_control (each member) */
58
59 /* VIDIOC_QUERYBUF, VIDIOC_QBUF, VIDIOC_DQBUF, VIDIOC_PREPARE_BUF */
60 { _IOWR('V', 9, new_misaligned(68)), _IOWR('V', 9, char[68]), 68, WR, 1, OFFS(20, 24) },
61 { _IOWR('V', 15, new_misaligned(68)), _IOWR('V', 15, char[68]), 68, WR, 1, OFFS(20, 24) },
62 { _IOWR('V', 17, new_misaligned(68)), _IOWR('V', 17, char[68]), 68, WR, 1, OFFS(20, 24) },
63 { _IOWR('V', 93, new_misaligned(68)), _IOWR('V', 93, char[68]), 68, WR, 1, OFFS(20, 24) },
64
65 /* VIDIOC_DQEVENT */
66 { _IOR('V', 89, new_misaligned(120)), _IOR('V', 89, struct v4l2_event), sizeof(struct v4l2_event),
67 R, 0, OFFS(offsetof(struct v4l2_event, ts[0]), offsetof(struct v4l2_event, ts[1])) },
68
69 /* VIDIOC_OMAP3ISP_STAT_REQ */
70 { _IOWR('V', 192+6, char[32]), _IOWR('V', 192+6, char[24]), 22, WR, 0, OFFS(0,4) },
71
72 /* PPPIOCGIDLE */
73 { _IOR('t', 63, char[16]), _IOR('t', 63, char[8]), 8, R, 0, OFFS(0,4) },
74
75 /* PPGETTIME, PPSETTIME */
76 { _IOR('p', 0x95, char[16]), _IOR('p', 0x95, char[8]), 8, R, 0, OFFS(0,4) },
77 { _IOW('p', 0x96, char[16]), _IOW('p', 0x96, char[8]), 8, W, 0, OFFS(0,4) },
78
79 /* LPSETTIMEOUT */
80 { _IOW(0x6, 0xf, char[16]), 0x060f, 8, W, 0, OFFS(0,4) },
81 };
82
83 static void convert_ioctl_struct(const struct ioctl_compat_map *map, char *old, char *new, int dir)
84 {
85 int new_offset = 0;
86 int old_offset = 0;
87 int old_size = map->old_size;
88 if (!(dir & map->dir)) return;
89 if (!map->old_size) {
90 /* offsets hard-coded for SNDRV_PCM_IOCTL_SYNC_PTR;
91 * if another exception appears this needs changing. */
92 convert_ioctl_struct(map+1, old, new, dir);
93 convert_ioctl_struct(map+2, old+4, new+8, dir);
94 /* snd_pcm_mmap_control, special-cased due to kernel
95 * type definition having been botched. */
96 int adj = BYTE_ORDER==BIG_ENDIAN ? 4 : 0;
97 convert_ioctl_struct(map+3, old+68, new+72+adj, dir);
98 convert_ioctl_struct(map+3, old+72, new+76+3*adj, dir);
99 return;
100 }
101 for (int i=0; i < map->noffs; i++) {
102 int ts_offset = map->offsets[i];
103 int len = ts_offset-old_offset;
104 if (dir==W) memcpy(old+old_offset, new+new_offset, len);
105 else memcpy(new+new_offset, old+old_offset, len);
106 new_offset += len;
107 old_offset += len;
108 long long new_ts;
109 long old_ts;
110 int align = map->force_align ? sizeof(time_t) : alignof(time_t);
111 new_offset += (align-1) & -new_offset;
112 if (dir==W) {
113 memcpy(&new_ts, new+new_offset, sizeof new_ts);
114 old_ts = new_ts;
115 memcpy(old+old_offset, &old_ts, sizeof old_ts);
116 } else {
117 memcpy(&old_ts, old+old_offset, sizeof old_ts);
118 new_ts = old_ts;
119 memcpy(new+new_offset, &new_ts, sizeof new_ts);
120 }
121 new_offset += sizeof new_ts;
122 old_offset += sizeof old_ts;
123 }
124 if (dir==W) memcpy(old+old_offset, new+new_offset, old_size-old_offset);
125 else memcpy(new+new_offset, old+old_offset, old_size-old_offset);
126 }
127
128 int ioctl(int fd, int req, ...)
129 {
130 void *arg;
131 va_list ap;
132 va_start(ap, req);
133 arg = va_arg(ap, void *);
134 va_end(ap);
135 int r = __syscall(SYS_ioctl, fd, req, arg);
136 if (SIOCGSTAMP != SIOCGSTAMP_OLD && req && r==-ENOTTY) {
137 for (int i=0; i<sizeof compat_map/sizeof *compat_map; i++) {
138 if (compat_map[i].new_req != req) continue;
139 union {
140 long long align;
141 char buf[256];
142 } u;
143 convert_ioctl_struct(&compat_map[i], u.buf, arg, W);
144 r = __syscall(SYS_ioctl, fd, compat_map[i].old_req, u.buf);
145 if (r<0) break;
146 convert_ioctl_struct(&compat_map[i], u.buf, arg, R);
147 break;
148 }
149 }
150 return __syscall_ret(r);
151 }
152