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/*
* Copyright (C) 2014-2021 Firejail Authors
*
* This file is part of firejail project
*
* 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 2 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <fnmatch.h>
#define MAX_READ 4096 // maximum line length
char *restricted_user = NULL;
int restricted_shell(const char *user) {
EUID_ASSERT();
assert(user);
// open profile file:
char *fname;
if (asprintf(&fname, "%s/login.users", SYSCONFDIR) == -1)
errExit("asprintf");
FILE *fp = fopen(fname, "re");
free(fname);
if (fp == NULL)
return 0;
int lineno = 0;
char buf[MAX_READ];
while (fgets(buf, MAX_READ, fp)) {
lineno++;
// remove empty spaces at the beginning of the line
char *ptr = buf;
while (*ptr == ' ' || *ptr == '\t') {
ptr++;
}
if (*ptr == '\n' || *ptr == '#')
continue;
//
// parse line
//
// extract users
char *usr = ptr;
char *args = strchr(usr, ':');
if (args == NULL) {
fprintf(stderr, "Error: users.conf line %d\n", lineno);
exit(1);
}
*args = '\0';
args++;
ptr = strchr(args, '\n');
if (ptr)
*ptr = '\0';
// extract firejail command line arguments
char *ptr2 = args;
int found = 0;
while (*ptr2 != '\0') {
if (*ptr2 != ' ' && *ptr2 != '\t') {
found = 1;
break;
}
ptr2++;
}
// if nothing follows, continue
if (!found)
continue;
// user name globbing
if (fnmatch(usr, user, 0) == 0) {
// process program arguments
fullargv[0] = "firejail";
int i;
ptr = args;
for (i = 1; i < MAX_ARGS; i++) {
// skip blanks
while (*ptr == ' ' || *ptr == '\t')
ptr++;
fullargv[i] = ptr;
#ifdef DEBUG_RESTRICTED_SHELL
{EUID_ROOT();
FILE *fp = fopen("/firelog", "ae");
if (fp) {
fprintf(fp, "i %d ptr #%s#\n", i, fullargv[i]);
fclose(fp);
}
EUID_USER();}
#endif
if (*ptr != '\0') {
// go to the end of the word
while (*ptr != ' ' && *ptr != '\t' && *ptr != '\0')
ptr++;
*ptr ='\0';
fullargv[i] = strdup(fullargv[i]);
if (fullargv[i] == NULL)
errExit("strdup");
ptr++;
while (*ptr == ' ' || *ptr == '\t')
ptr++;
if (*ptr != '\0')
continue;
}
fullargv[i] = strdup(fullargv[i]);
fclose(fp);
return i + 1;
}
fprintf(stderr, "Error: too many program arguments in users.conf line %d\n", lineno);
exit(1);
}
}
fclose(fp);
return 0;
}
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