1
0
Fork 0
mirror of https://gitlab.com/sortix/sortix.git synced 2023-02-13 20:55:38 -05:00

Add chroot(1).

This commit is contained in:
Jonas 'Sortie' Termansen 2013-05-30 00:58:56 +02:00
parent d2aab888d1
commit 94cd049473
3 changed files with 118 additions and 0 deletions

1
utils/.gitignore vendored
View file

@ -1,6 +1,7 @@
*.o
calc
cat
chroot
chvideomode
clear
colormake

View file

@ -17,6 +17,7 @@ CXXFLAGS:=$(CXXFLAGS) -Wall -Wextra -fno-exceptions -fno-rtti
BINARIES:=\
calc \
cat \
chroot \
chvideomode \
clear \
colormake \

116
utils/chroot.cpp Normal file
View file

@ -0,0 +1,116 @@
/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2013.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.
chroot.cpp
Runs a process with another root directory.
*******************************************************************************/
#include <errno.h>
#include <error.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if !defined(VERSIONSTR)
#define VERSIONSTR "unknown version"
#endif
void CompactArguments(int* argc, char*** argv)
{
for ( int i = 0; i < *argc; i++ )
while ( i < *argc && !(*argv)[i] )
{
for ( int n = i; n < *argc; n++ )
(*argv)[n] = (*argv)[n+1];
(*argc)--;
}
}
void Usage(FILE* fp, const char* argv0)
{
fprintf(fp, "Usage: %s [OPTION]... ROOT [CMD] [ARGUMENT...]\n", argv0);
}
void Help(FILE* fp, const char* argv0)
{
Usage(fp, argv0);
}
void Version(FILE* fp, const char* argv0)
{
fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR);
fprintf(fp, "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n");
fprintf(fp, "This is free software: you are free to change and redistribute it.\n");
fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n");
}
int main(int argc, char* argv[])
{
const char* argv0 = argv[0];
for ( int i = 1; i < argc; i++ )
{
const char* arg = argv[i];
if ( arg[0] != '-' )
continue;
argv[i] = NULL;
if ( !strcmp(arg, "--") )
break;
if ( arg[1] != '-' )
{
while ( char c = *++arg ) switch ( c )
{
default:
fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c);
Usage(stderr, argv0);
exit(1);
}
}
else if ( !strcmp(arg, "--help") ) { Help(stdout, argv0); exit(0); }
else if ( !strcmp(arg, "--usage") ) { Usage(stdout, argv0); exit(0); }
else if ( !strcmp(arg, "--version") ) { Version(stdout, argv0); exit(0); }
else
{
fprintf(stderr, "%s: unknown option: %s\n", argv0, arg);
Usage(stderr, argv0);
exit(1);
}
}
CompactArguments(&argc, &argv);
if ( argc < 2 )
{
error(0, 0, "missing operand, expected new root directory");
Usage(stdout, argv0);
exit(0);
}
if ( chroot(argv[1]) != 0 )
error(1, errno, "`%s'", argv[1]);
if ( chdir("/.") != 0 )
error(1, errno, "chdir: `%s/.'", argv[1]);
char* default_argv[] = { (char*) "sh", (char*) NULL };
char** exec_argv = 3 <= argc ? argv + 2 : default_argv;
execvp(exec_argv[0], exec_argv);
error(127, errno, "`%s'", exec_argv[0]);
}