libexplain  1.4.D001
libexplain/buffer/errno/setresgid.c
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00001 /*
00002  * libexplain - Explain errno values returned by libc functions
00003  * Copyright (C) 2012, 2013 Peter Miller
00004  *
00005  * This program is free software; you can redistribute it and/or modify it
00006  * under the terms of the GNU Lesser General Public License as published by
00007  * the Free Software Foundation; either version 3 of the License, or (at
00008  * your option) any later version.
00009  *
00010  * This program is distributed in the hope that it will be useful, but
00011  * WITHOUT ANY WARRANTY; without even the implied warranty of
00012  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
00013  * General Public License for more details.
00014  *
00015  * You should have received a copy of the GNU Lesser General Public License
00016  * along with this program. If not, see <http://www.gnu.org/licenses/>.
00017  */
00018 
00019 #include <libexplain/ac/errno.h>
00020 
00021 #include <libexplain/buffer/dac.h>
00022 #include <libexplain/buffer/eagain.h>
00023 #include <libexplain/buffer/eperm.h>
00024 #include <libexplain/buffer/errno/generic.h>
00025 #include <libexplain/buffer/errno/setresgid.h>
00026 #include <libexplain/buffer/gid.h>
00027 #include <libexplain/explanation.h>
00028 
00029 
00030 static void
00031 explain_buffer_eperm_setresgid(explain_string_buffer_t *sb, const char *caption,
00032     const char *rgid_str, const char *egid_str, const char *sgid_str)
00033 {
00034     explain_string_buffer_printf_gettext
00035     (
00036         sb,
00037         i18n
00038         (
00039             /*
00040              * xgettext: This error message is used to explain an EPERM error
00041              * reported by the setresgid system call, in the case where gid does
00042              * not match the real group ID or saved group ID of the calling
00043              * process, and the process is not privileged (Linux: does not have
00044              * the CAP_SETGID capability)
00045              */
00046             "the %1$s argument does not match the real group ID (%2$s) or the "
00047             "effective group ID (%3$s) or the saved group ID (%4$s) of the "
00048             "calling process"
00049         ),
00050         caption,
00051         rgid_str,
00052         egid_str,
00053         sgid_str
00054     );
00055     explain_buffer_dac_setgid(sb);
00056 }
00057 
00058 
00059 static void
00060 explain_buffer_errno_setresgid_system_call(explain_string_buffer_t *sb,
00061     int errnum, gid_t rgid, gid_t egid, gid_t sgid)
00062 {
00063     (void)errnum;
00064     explain_string_buffer_puts(sb, "setresgid(rgid = ");
00065     explain_buffer_gid(sb, rgid);
00066     explain_string_buffer_puts(sb, ", egid = ");
00067     explain_buffer_gid(sb, egid);
00068     explain_string_buffer_puts(sb, ", sgid = ");
00069     explain_buffer_gid(sb, sgid);
00070     explain_string_buffer_putc(sb, ')');
00071 }
00072 
00073 
00074 void
00075 explain_buffer_errno_setresgid_explanation(explain_string_buffer_t *sb,
00076     int errnum, const char *syscall_name, gid_t rgid, gid_t egid, gid_t sgid)
00077 {
00078     gid_t           crgid = -1;
00079     char            rgid_str[100];
00080     gid_t           cegid = -1;
00081     char            egid_str[100];
00082     gid_t           csgid = -1;
00083     char            sgid_str[100];
00084     const gid_t     minus1 = -1;
00085 
00086     /*
00087      * http://www.opengroup.org/onlinepubs/009695399/functions/setresgid.html
00088      */
00089     switch (errnum)
00090     {
00091     case EPERM:
00092         /* build the strings we will need to report the error */
00093         {
00094             explain_string_buffer_t rgid_sb;
00095             explain_string_buffer_t egid_sb;
00096             explain_string_buffer_t sgid_sb;
00097 
00098             explain_string_buffer_init(&rgid_sb, rgid_str, sizeof(rgid_str));
00099             explain_buffer_gid(&rgid_sb, crgid);
00100             explain_string_buffer_init(&egid_sb, egid_str, sizeof(egid_str));
00101             explain_buffer_gid(&egid_sb, cegid);
00102             explain_string_buffer_init(&sgid_sb, sgid_str, sizeof(sgid_str));
00103             explain_buffer_gid(&sgid_sb, csgid);
00104         }
00105 
00106         if (rgid != minus1 && rgid != crgid && rgid != cegid && rgid != csgid)
00107         {
00108             explain_buffer_eperm_setresgid(sb, "rgid", rgid_str, egid_str,
00109                 sgid_str);
00110             break;
00111         }
00112         if (egid != minus1 && egid != crgid && egid != cegid && egid != csgid)
00113         {
00114             explain_buffer_eperm_setresgid(sb, "egid", rgid_str, egid_str,
00115                 sgid_str);
00116             break;
00117         }
00118         if (sgid != minus1 && sgid != crgid && sgid != cegid && sgid != csgid)
00119         {
00120             explain_buffer_eperm_setresgid(sb, "sgid", rgid_str, egid_str,
00121                 sgid_str);
00122             break;
00123         }
00124         /* Fall through... */
00125 
00126     default:
00127         explain_buffer_errno_generic(sb, errnum, syscall_name);
00128         break;
00129     }
00130 }
00131 
00132 
00133 void
00134 explain_buffer_errno_setresgid(explain_string_buffer_t *sb, int errnum, gid_t
00135     rgid, gid_t egid, gid_t sgid)
00136 {
00137     explain_explanation_t exp;
00138 
00139     explain_explanation_init(&exp, errnum);
00140     explain_buffer_errno_setresgid_system_call(&exp.system_call_sb, errnum,
00141         rgid, egid, sgid);
00142     explain_buffer_errno_setresgid_explanation(&exp.explanation_sb, errnum,
00143         "setresgid", rgid, egid, sgid);
00144     explain_explanation_assemble(&exp, sb);
00145 }
00146 
00147 
00148 /* vim: set ts=8 sw=4 et : */