SELinux-related 6.0 fixes

* Run restorecon on /data/.layout_version
* Fix firmware image mounting, remove obsolete fw_mounter
* Add mechanism to append things to rc files

Android.mk

@@ -19,6 +19,7 @@ LOCAL_SRC_FILES:= \
     multirom_ui_portrait.c \
     multirom_ui_themes.c \
     pong.c \
+    rcadditions.c \
     rom_quirks.c \
 
 # With these, GCC optimizes aggressively enough so full-screen alpha blending
@@ -60,9 +61,6 @@ include $(BUILD_EXECUTABLE)
 # Trampoline
 include $(multirom_local_path)/trampoline/Android.mk
 
-# fw_mounter
-include $(multirom_local_path)/fw_mounter/Android.mk
-
 # ZIP installer
 include $(multirom_local_path)/install_zip/Android.mk
 

fw_mounter/Android.mk

@@ -1,17 +0,0 @@
-LOCAL_PATH:= $(call my-dir)
-include $(CLEAR_VARS)
-
-LOCAL_C_INCLUDES += $(multirom_local_path)
-LOCAL_SRC_FILES:= \
-    fw_mounter.c \
-
-LOCAL_MODULE := fw_mounter
-LOCAL_MODULE_TAGS := eng
-
-LOCAL_FORCE_STATIC_EXECUTABLE := true
-LOCAL_MODULE_PATH := $(TARGET_ROOT_OUT)
-LOCAL_UNSTRIPPED_PATH := $(TARGET_ROOT_OUT_UNSTRIPPED)
-
-LOCAL_STATIC_LIBRARIES := libcutils libc libmultirom_static
-
-include $(BUILD_EXECUTABLE)

fw_mounter/fw_mounter.c

@@ -1,47 +0,0 @@
-/*
- * This file is part of MultiROM.
- *
- * MultiROM 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.
- *
- * MultiROM 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 MultiROM.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <unistd.h>
-#include <stdlib.h>
-#include <stdio.h>
-
-#include "../lib/log.h"
-#include "../lib/util.h"
-#include "../lib/fstab.h"
-#include "fw_mounter_defines.h"
-
-int main(int argc, char *argv[])
-{
-    mrom_set_log_tag("fw_mounter");
-
-    struct fstab *f = fstab_load(FW_MOUNTER_FSTAB, 0);
-    if(!f)
-    {
-        ERROR("Failed to load %s\n", FW_MOUNTER_FSTAB);
-        return -1;
-    }
-
-    struct fstab_part *fw_part = fstab_find_first_by_path(f, "/firmware");
-    if(!fw_part)
-    {
-        ERROR("Unable to find partition /firmware in %s!\n", FW_MOUNTER_FSTAB);
-        return -1;
-    }
-
-    ERROR("Mounting %s to %s\n", fw_part->device, fw_part->path);
-    return mount_image(fw_part->device, fw_part->path, fw_part->type, fw_part->mountflags, fw_part->options);
-}

install_zip/Android.mk

@@ -24,7 +24,7 @@ ifneq ($(MR_DEVICE_VARIANTS),)
 	MR_DEVICES += $(MR_DEVICE_VARIANTS)
 endif
 
-$(MULTIROM_ZIP_TARGET): multirom trampoline fw_mounter signapk bbootimg mrom_kexec_static mrom_adbd $(multirom_extra_dep)
+$(MULTIROM_ZIP_TARGET): multirom trampoline signapk bbootimg mrom_kexec_static mrom_adbd $(multirom_extra_dep)
 	@echo
 	@echo
 	@echo "A crowdfunding campaign for MultiROM took place in 2013. These people got perk 'The Tenth':"

multirom.c

@@ -51,7 +51,6 @@
 #include "hooks.h"
 #include "rom_quirks.h"
 #include "kexec.h"
-#include "fw_mounter/fw_mounter_defines.h"
 
 #define REALDATA "/realdata"
 #define BUSYBOX_BIN "busybox"
@@ -253,7 +252,7 @@ void multirom_emergency_reboot(void)
     char *tail;
     char *last_end;
     int cur_y;
-    uid_t media_rw_id;
+    unsigned int media_rw_id;
 
     if(multirom_init_fb(0) < 0)
     {
@@ -306,7 +305,7 @@ void multirom_emergency_reboot(void)
     free(klog);
 
     media_rw_id = decode_uid("media_rw");
-    if(media_rw_id != -1)
+    if(media_rw_id != -1U)
         chown("../multirom_log.txt", (uid_t)media_rw_id, (gid_t)media_rw_id);
     chmod("../multirom_log.txt", 0666);
 
@@ -990,13 +989,16 @@ int multirom_prepare_for_boot(struct multirom_status *s, struct multirom_rom *to
             {
                 exit &= ~(EXIT_UMOUNT);
 
-                if(multirom_prep_android_mounts(to_boot) == -1)
+                if(multirom_prep_android_mounts(s, to_boot) == -1)
                     return -1;
 
-                if(multirom_create_media_link() == -1)
+                if(multirom_create_media_link(s) == -1)
                     return -1;
 
                 rom_quirks_on_initrd_finalized();
+
+                rcadditions_write_to_files(&s->rc);
+                rcadditions_free(&s->rc);
             }
 
             if(to_boot->partition)
@@ -1064,66 +1066,39 @@ char *multirom_find_fstab_in_rc(const char *rcfile)
 // works. There is a chance Google will disable all services which don't have
 // context set in sepolicy. That will be a problem.
 
-static int multirom_inject_fw_mounter(char *rc_with_mount_all, struct fstab_part *fw_part)
+// UPDATE: fw_mounter gets shut down by SELinux on 6.0, inject .rc files and file_contexts instead.
+
+static int multirom_inject_fw_mounter(struct multirom_status *s, struct fstab_part *fw_part)
 {
-    static const char *trigger_line = "    start mrom_fw_mounter\n";
-    static const char *service_block =
-        "\nservice mrom_fw_mounter "FW_MOUNTER_PATH"\n"
-        "    disabled\n"
-        "    oneshot\n"
-        "    user root\n"
-        "    group root\n";
+    char buf[512];
 
-    char *rc_file, *p;
-    size_t rc_len, alloc_size;
-    char line[512];
-    FILE *f = fopen(rc_with_mount_all, "r+e");
-    if(!f)
+    rcadditions_append_contexts(&s->rc,
+        "/realdata/media/0/multirom/roms/[^/]+/firmware.img u:object_r:asec_image_file:s0\n"
+        "/realdata/media/multirom/roms/[^/]+/firmware.img u:object_r:asec_image_file:s0\n");
+
+    snprintf(buf, sizeof(buf), "    restorecon %s\n", fw_part->device);
+    rcadditions_append_trigger(&s->rc, "fs", buf);
+
+    snprintf(buf, sizeof(buf), "    mount %s loop@%s %s ", fw_part->type, fw_part->device, fw_part->path);
+    rcadditions_append_trigger(&s->rc, "fs", buf);
+
+    if(fw_part->options_raw)
     {
-        ERROR("Failed to open file \"%s\" to inject fw_mounter!\n", rc_with_mount_all);
-        fstab_destroy_part(fw_part);
-        return -1;
+        char *c, *opts = strdup(fw_part->options_raw);
+        for(c = opts; *c; ++c)
+            if(*c == ',')
+                *c = ' ';
+        rcadditions_append_trigger(&s->rc, "fs", opts);
+        free(opts);
     }
 
-    fseek(f, 0, SEEK_END);
-    rc_len = ftell(f);
-    fseek(f, 0, SEEK_SET);
-
-    alloc_size = rc_len + 1 + strlen(trigger_line);
-    rc_file = malloc(alloc_size);
-    rc_file[0] = 0;
-
-    while(fgets(line, sizeof(line), f))
-    {
-        for(p = line; isspace(*p); ++p);
-
-        if(*p && *p != '#' && line[strlen(line)-1] == '\n' && strncmp(p, "mount_all", 9) == 0)
-            strcat(rc_file, trigger_line);
-        strcat(rc_file, line);
-    }
-
-    fseek(f, 0, SEEK_SET);
-    fputs(rc_file, f);
-    fputs(service_block, f);
-
-    free(rc_file);
-    fclose(f);
-
-    // copy fw_mounter to /sbin
-    snprintf(line, sizeof(line), "%s/%s", mrom_dir(), FW_MOUNTER_BIN);
-    copy_file(line, FW_MOUNTER_PATH);
-    chmod(FW_MOUNTER_PATH, 0755);
-
-    // prepare fstab for it
-    struct fstab *fw_fstab = fstab_create_empty(2);
-    fstab_add_part_struct(fw_fstab, fw_part);
-    fstab_save(fw_fstab, FW_MOUNTER_FSTAB);
-    fstab_destroy(fw_fstab);
+    rcadditions_append_trigger(&s->rc, "fs", "\n");
 
+    fstab_destroy_part(fw_part);
     return 0;
 }
 
-int multirom_prep_android_mounts(struct multirom_rom *rom)
+int multirom_prep_android_mounts(struct multirom_status *s, struct multirom_rom *rom)
 {
     char in[128];
     char out[128];
@@ -1219,14 +1194,11 @@ int multirom_prep_android_mounts(struct multirom_rom *rom)
 
     if(has_fw && fw_part)
     {
-        // Can't mount the image here because it might clash with /firmware mounted
-        // for encryption
-        INFO("Mounting ROM's FW image instead of FW partition, using fw_mounter\n");
+        INFO("Mounting ROM's FW image instead of FW partition\n");
         snprintf(from, sizeof(from), "%s/firmware.img", rom->base_path);
         fw_part->device = realloc(fw_part->device, strlen(from)+1);
         strcpy(fw_part->device, from);
-        multirom_inject_fw_mounter(rc_with_mount_all, fw_part);
-        fw_part = NULL;
+        multirom_inject_fw_mounter(s, fw_part);
     }
 
 #if MR_DEVICE_HOOKS >= 1
@@ -1328,7 +1300,7 @@ exit:
     return res;
 }
 
-int multirom_create_media_link(void)
+int multirom_create_media_link(struct multirom_status *s)
 {
     int media_new = 0;
     int api_level = multirom_get_api_level("/system/build.prop");
@@ -1399,6 +1371,10 @@ int multirom_create_media_link(void)
             fclose(f);
             chmod(LAYOUT_VERSION, 0600);
         }
+
+        // We need to set SELinux context for this file in case it was created by multirom,
+        // but can't do it here because selinux was not initialized
+        rcadditions_append_trigger(&s->rc, "post-fs-data", "    restorecon " LAYOUT_VERSION "\n");
     }
 
     return 0;

multirom.h

@@ -24,6 +24,7 @@
 #include "lib/fstab.h"
 #include "lib/containers.h"
 #include "kexec.h"
+#include "rcadditions.h"
 
 enum
 {
@@ -114,6 +115,7 @@ struct multirom_status
     struct usb_partition **partitions;
     char *curr_rom_part;
     struct fstab *fstab;
+    struct rcadditions rc;
 };
 
 int multirom(const char *rom_to_boot);
@@ -134,8 +136,8 @@ int multirom_prepare_for_boot(struct multirom_status *s, struct multirom_rom *to
 void multirom_free_status(struct multirom_status *s);
 void multirom_free_rom(void *rom);
 int multirom_init_fb(int rotation);
-int multirom_prep_android_mounts(struct multirom_rom *rom);
-int multirom_create_media_link(void);
+int multirom_prep_android_mounts(struct multirom_status *s, struct multirom_rom *rom);
+int multirom_create_media_link(struct multirom_status *s);
 int multirom_process_android_fstab(char *fstab_name, int has_fw, struct fstab_part **fw_part);
 int multirom_get_api_level(const char *path);
 int multirom_get_rom_type(struct multirom_rom *rom);

rcadditions.c

@@ -0,0 +1,123 @@
+/*
+ * This file is part of MultiROM.
+ *
+ * MultiROM 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.
+ *
+ * MultiROM 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 MultiROM.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+#include "lib/log.h"
+#include "rcadditions.h"
+
+static void append_string_buffer(char **buf, const char *what) {
+    size_t old_len = 0;
+    if(*buf)
+        old_len += strlen(*buf);
+
+    *buf = realloc(*buf, old_len + strlen(what) + 1);
+    (*buf)[old_len] = 0;
+    strcat(*buf, what);
+}
+
+void rcadditions_append_trigger(struct rcadditions *r, const char *trigger, const char *what) {
+    if(r->triggers == NULL)
+        r->triggers = map_create();
+
+    char **ref = (char**)map_get_ref(r->triggers, trigger);
+    if(ref == NULL)
+        map_add_not_exist(r->triggers, trigger, strdup(what));
+    else
+        append_string_buffer(ref, what);
+}
+
+void rcadditions_append_file(struct rcadditions *r, const char *what) {
+    append_string_buffer(&r->eof_append, what);
+}
+
+void rcadditions_append_contexts(struct rcadditions *r, const char *what) {
+    append_string_buffer(&r->file_contexts_append, what);
+}
+
+void rcadditions_free(struct rcadditions *r)
+{
+    free(r->eof_append);
+    r->eof_append = NULL;
+
+    free(r->file_contexts_append);
+    r->file_contexts_append = NULL;
+
+    map_destroy(r->triggers, &free);
+    r->triggers = NULL;
+}
+
+void rcadditions_write_to_files(struct rcadditions *r)
+{
+    if(r->eof_append == NULL && r->triggers == NULL)
+        return;
+
+    FILE *f = fopen("/init.multirom.rc", "we");
+    if(!f)
+    {
+        ERROR("Failed to create init.multirom.rc: %s\n", strerror(errno));
+        return;
+    }
+
+    fputs("# This file is autogenerated by MultiROM during boot\n\n", f);
+
+    if(r->triggers)
+    {
+        size_t i = 0;
+        for(; i < r->triggers->size; ++i)
+        {
+            fprintf(f, "on %s\n", r->triggers->keys[i]);
+            fputs((char*)r->triggers->values[i], f);
+            fputc('\n', f);
+        }
+    }
+
+    if(r->eof_append)
+    {
+        fputc('\n', f);
+        fputs(r->eof_append, f);
+    }
+    fclose(f);
+
+    chmod("/init.multirom.rc", 0750);
+
+    f = fopen("/init.rc", "ae");
+    if(!f)
+    {
+        ERROR("Failed to open init.rc: %s\n", strerror(errno));
+        return;
+    }
+    fputs("\n# Added by MultiROM\nimport /init.multirom.rc\n", f);
+    fclose(f);
+
+    if(r->file_contexts_append)
+    {
+        f = fopen("/file_contexts", "ae");
+        if(!f)
+        {
+            ERROR("Failed to open file_contexts: %s\n", strerror(errno));
+            return;
+        }
+        fputs("\n# Added by multirom during boot\n", f);
+        fputs(r->file_contexts_append, f);
+        fclose(f);
+    }
+}

rcadditions.h

@@ -15,11 +15,22 @@
  * along with MultiROM.  If not, see <http://www.gnu.org/licenses/>.
  */
 
- #ifndef FW_MOUNTER_DEFINES_H
- #define FW_MOUNTER_DEFINES_H
+#ifndef RCADDITIONS_H
+#define RCADDITIONS_H
 
- #define FW_MOUNTER_FSTAB "/sbin/fw_mounter.fstab"
- #define FW_MOUNTER_BIN "fw_mounter"
- #define FW_MOUNTER_PATH "/sbin/"FW_MOUNTER_BIN
+#include "lib/containers.h"
 
- #endif
+struct rcadditions
+{
+    map *triggers;
+    char *eof_append;
+    char *file_contexts_append;
+};
+
+void rcadditions_append_trigger(struct rcadditions *r, const char *trigger, const char *what);
+void rcadditions_append_file(struct rcadditions *r, const char *what);
+void rcadditions_append_contexts(struct rcadditions *r, const char *what);
+void rcadditions_free(struct rcadditions *r);
+void rcadditions_write_to_files(struct rcadditions *r);
+
+#endif

rom_quirks.c

@@ -85,7 +85,7 @@ static void inject_file_contexts(void)
 
     fclose(f);
 
-    INFO("Injecting /file_contexts");
+    INFO("Injecting /file_contexts\n");
     f = fopen("/file_contexts", "ae");
     if(!f)
     {