1 files changed, 157 insertions, 0 deletions

diff --git a/src/firejail/fs_hostname.c b/src/firejail/fs_hostname.c
new file mode 100644
index 000000000..fb3fc530e
--- /dev/null
+++ b/src/firejail/fs_hostname.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2014, 2015 netblue30 (netblue30@yahoo.com)
+ *
+ * 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 <sys/mount.h>
+#include <sys/stat.h>
+#include <linux/limits.h>
+#include <glob.h>
+#include <dirent.h>
+#include <fcntl.h>
+
+void fs_hostname(const char *hostname) {
+        struct stat s;
+        fs_build_mnt_dir();
+        
+        // create a new /etc/hostname
+        if (stat("/etc/hostname", &s) == 0) {
+                if (arg_debug)
+                        printf("Creating a new /etc/hostname file\n");
+                char *fhost;
+                if (asprintf(&fhost, "%s/hostname", MNT_DIR) == -1)
+                        errExit("asprintf");
+                FILE *fp = fopen(fhost, "w");
+                if (!fp) {
+                        fprintf(stderr, "Error: cannot create %s\n", fhost);
+                        free(fhost);
+                        exit(1);
+                }
+                fprintf(fp, "%s\n", hostname);
+                fclose(fp);
+                
+                // mode and owner
+                if (chown(fhost, 0, 0) < 0)
+                        errExit("chown");
+                if (chmod(fhost, S_IRUSR | S_IWRITE | S_IRGRP | S_IROTH ) < 0)
+                        errExit("chmod");
+                
+                // bind-mount the file on top of /etc/hostname
+                if (mount(fhost, "/etc/hostname", NULL, MS_BIND|MS_REC, NULL) < 0)
+                        errExit("mount bind /etc/hostname");
+                free(fhost);
+        }
+        
+        // create a new /etc/hosts
+        if (stat("/etc/hosts", &s) == 0) {
+                if (arg_debug)
+                        printf("Creating a new /etc/hosts file\n");
+                char *fhost;
+                if (asprintf(&fhost, "%s/hosts", MNT_DIR) == -1)
+                        errExit("asprintf");
+                // copy /etc/host into our new file, and modify it on the fly
+                /* coverity[toctou] */
+                FILE *fp1 = fopen("/etc/hosts", "r");
+                if (!fp1) {
+                        fprintf(stderr, "Error: cannot open /etc/hosts\n");
+                        free(fhost);
+                        exit(1);
+                }
+                FILE *fp2 = fopen(fhost, "w");
+                if (!fp2) {
+                        fprintf(stderr, "Error: cannot create %s\n", fhost);
+                        free(fhost);
+                        exit(1);
+                }
+                
+                char buf[4096];
+                while (fgets(buf, sizeof(buf), fp1)) {
+                        // remove '\n'
+                        char *ptr = strchr(buf, '\n');
+                        if (ptr)
+                                *ptr = '\0';
+                                
+                        // copy line
+                        if (strstr(buf, "127.0.0.1"))
+                                fprintf(fp2, "%s %s\n", buf, hostname);
+                        else
+                                fprintf(fp2, "%s\n", buf);
+                }
+                fclose(fp1);
+                fclose(fp2);
+                
+                // mode and owner
+                if (chown(fhost, 0, 0) < 0)
+                        errExit("chown");
+                if (chmod(fhost, S_IRUSR | S_IWRITE | S_IRGRP | S_IROTH ) < 0)
+                        errExit("chmod");
+                
+                // bind-mount the file on top of /etc/hostname
+                if (mount(fhost, "/etc/hosts", NULL, MS_BIND|MS_REC, NULL) < 0)
+                        errExit("mount bind /etc/hosts");
+                free(fhost);
+        }
+}
+
+void fs_resolvconf(void) {
+        if (cfg.dns1 == 0)
+                return;
+                
+        struct stat s;
+        fs_build_mnt_dir();
+        
+        // create a new /etc/hostname
+        if (stat("/etc/resolv.conf", &s) == 0) {
+                if (arg_debug)
+                        printf("Creating a new /etc/resolv.conf file\n");
+                char *fname;
+                if (asprintf(&fname, "%s/resolv.conf", MNT_DIR) == -1)
+                        errExit("asprintf");
+                FILE *fp = fopen(fname, "w");
+                if (!fp) {
+                        fprintf(stderr, "Error: cannot create %s\n", fname);
+                        free(fname);
+                        exit(1);
+                }
+                
+                if (cfg.dns1)
+                        fprintf(fp, "nameserver %d.%d.%d.%d\n", PRINT_IP(cfg.dns1));
+                if (cfg.dns2)
+                        fprintf(fp, "nameserver %d.%d.%d.%d\n", PRINT_IP(cfg.dns2));
+                if (cfg.dns3)
+                        fprintf(fp, "nameserver %d.%d.%d.%d\n", PRINT_IP(cfg.dns3));
+                fclose(fp);
+                
+                // mode and owner
+                if (chown(fname, 0, 0) < 0)
+                        errExit("chown");
+                if (chmod(fname, S_IRUSR | S_IWRITE | S_IRGRP | S_IROTH ) < 0)
+                        errExit("chmod");
+                
+                // bind-mount the file on top of /etc/hostname
+                if (mount(fname, "/etc/resolv.conf", NULL, MS_BIND|MS_REC, NULL) < 0)
+                        errExit("mount bind /etc/resolv.conf");
+                free(fname);
+        }
+        else {
+                fprintf(stderr, "Error: cannot set DNS servers, /etc/resolv.conf file is missing\n");
+                exit(1);
+        }
+}
+
+