src/misc/ioctl.c

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