libexplain  1.4.D001
libexplain/iocontrol/vidiocsync.c
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00001 /*
00002  * libexplain - a library of system-call-specific strerror replacements
00003  * Copyright (C) 2011, 2013 Peter Miller
00004  * Written by Peter Miller <pmiller@opensource.org.au>
00005  *
00006  * This program is free software; you can redistribute it and/or modify it
00007  * under the terms of the GNU Lesser General Public License as published by
00008  * the Free Software Foundation; either version 3 of the License, or (at your
00009  * option) any later version.
00010  *
00011  * This program is distributed in the hope that it will be useful, but WITHOUT
00012  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
00013  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
00014  * License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public License
00017  * along with this program. If not, see <http://www.gnu.org/licenses/>.
00018  */
00019 
00020 #include <libexplain/ac/errno.h>
00021 #include <libexplain/ac/linux/videodev.h>
00022 #include <libexplain/ac/string.h>
00023 #include <libexplain/ac/sys/ioctl.h>
00024 
00025 #include <libexplain/buffer/einval.h>
00026 #include <libexplain/buffer/is_the_null_pointer.h>
00027 #include <libexplain/iocontrol/generic.h>
00028 #include <libexplain/iocontrol/vidiocsync.h>
00029 #include <libexplain/is_efault.h>
00030 
00031 #ifdef VIDIOCSYNC
00032 
00033 
00034 static void
00035 print_explanation(const explain_iocontrol_t *p, explain_string_buffer_t *sb,
00036     int errnum, int fildes, int request, const void *data)
00037 {
00038     switch (errnum)
00039     {
00040     case EINVAL:
00041         if (!data)
00042         {
00043             explain_buffer_is_the_null_pointer(sb, "data");
00044             return;
00045         }
00046 
00047         /*
00048          * framenum is probably out of range
00049          */
00050         {
00051             const int       *arg;
00052 
00053             arg = data;
00054             if (!explain_is_efault_pointer(arg, sizeof(*arg)))
00055             {
00056                 struct video_mbuf qry;
00057 
00058                 memset(&qry, 0, sizeof(qry));
00059                 if
00060                 (
00061                     ioctl(fildes, VIDIOCGMBUF, &qry) >= 0
00062                 &&
00063                     qry.frames > 0
00064                 &&
00065                     (*arg < 0 || *arg >= qry.frames)
00066                 )
00067                 {
00068                     explain_buffer_einval_out_of_range
00069                     (
00070                         sb,
00071                         "data",
00072                         0,
00073                         qry.frames - 1
00074                     );
00075                     return;
00076                 }
00077             }
00078         }
00079 
00080         explain_buffer_einval_vague(sb, "data");
00081         break;
00082 
00083     default:
00084         explain_iocontrol_generic_print_explanation
00085         (
00086             p,
00087             sb,
00088             errnum,
00089             fildes,
00090             request,
00091             data
00092         );
00093         break;
00094     }
00095 }
00096 
00097 
00098 const explain_iocontrol_t explain_iocontrol_vidiocsync =
00099 {
00100     "VIDIOCSYNC", /* name */
00101     VIDIOCSYNC, /* value */
00102     0, /* disambiguate */
00103     0, /* print_name */
00104     explain_iocontrol_generic_print_data_int_star, /* print_data */
00105     print_explanation,
00106     0, /* print_data_returned */
00107     sizeof(int), /* data_size */
00108     "int *", /* data type */
00109     0, /* flags */
00110     __FILE__,
00111     __LINE__,
00112 };
00113 
00114 #else /* ndef VIDIOCSYNC */
00115 
00116 const explain_iocontrol_t explain_iocontrol_vidiocsync =
00117 {
00118     0, /* name */
00119     0, /* value */
00120     0, /* disambiguate */
00121     0, /* print_name */
00122     0, /* print_data */
00123     0, /* print_explanation */
00124     0, /* print_data_returned */
00125     0, /* data_size */
00126     0, /* data_type */
00127     0, /* flags */
00128     __FILE__,
00129     __LINE__,
00130 };
00131 
00132 #endif /* VIDIOCSYNC */
00133 
00134 /* vim: set ts=8 sw=4 et : */