adb: configure /system file permission with fs_config

adbd changes the permissions of files uploaded by copying
owner's permission to group and other. This causes kernel
load failure if any changes are made to kernel modules
followed by ``adb push'' or ``adb sync'' because file mode
644 would become 666.

The change uses fs_config to get the target mode of files.

In addition, the SELinux file label is set incorrectly
on synced files. Set the label properly.

Change-Id: I354db848f39adfbf189d7e8d3b028e8d763c772f
Signed-off-by: Liang Cheng <licheng@nvidia.com>
Bug: 12264775

2 files changed, 65 insertions, 10 deletions

diff --git a/adb/Android.mk b/adb/Android.mk
index 721b48d..155c6e5 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -130,7 +130,7 @@ LOCAL_FORCE_STATIC_EXECUTABLE := true
 LOCAL_MODULE_PATH := $(TARGET_ROOT_OUT_SBIN)
 LOCAL_UNSTRIPPED_PATH := $(TARGET_ROOT_OUT_SBIN_UNSTRIPPED)
 
-LOCAL_STATIC_LIBRARIES := liblog libcutils libc libmincrypt
+LOCAL_STATIC_LIBRARIES := liblog libcutils libc libmincrypt libselinux
 include $(BUILD_EXECUTABLE)
 
 
diff --git a/adb/file_sync_service.c b/adb/file_sync_service.c
index f24f14c..c30f9fb 100644
--- a/adb/file_sync_service.c
+++ b/adb/file_sync_service.c
@@ -22,19 +22,32 @@
 #include <sys/types.h>
 #include <dirent.h>
 #include <utime.h>
+#include <unistd.h>
 
 #include <errno.h>
-
+#include <private/android_filesystem_config.h>
+#include <selinux/android.h>
 #include "sysdeps.h"
 
 #define TRACE_TAG  TRACE_SYNC
 #include "adb.h"
 #include "file_sync_service.h"
 
+/* TODO: use fs_config to configure permissions on /data */
+static bool is_on_system(const char *name) {
+    const char *SYSTEM = "/system/";
+    return (strncmp(SYSTEM, name, strlen(SYSTEM)) == 0);
+}
+
 static int mkdirs(char *name)
 {
     int ret;
     char *x = name + 1;
+    unsigned int uid, gid;
+    unsigned int mode = 0775;
+    uint64_t cap = 0;
+    uid = getuid();
+    gid = getgid();
 
     if(name[0] != '/') return -1;
 
@@ -42,11 +55,21 @@ static int mkdirs(char *name)
         x = adb_dirstart(x);
         if(x == 0) return 0;
         *x = 0;
-        ret = adb_mkdir(name, 0775);
+        if (is_on_system(name)) {
+            fs_config(name, 1, &uid, &gid, &mode, &cap);
+        }
+        ret = adb_mkdir(name, mode);
         if((ret < 0) && (errno != EEXIST)) {
             D("mkdir(\"%s\") -> %s\n", name, strerror(errno));
             *x = '/';
             return ret;
+        } else if(ret == 0) {
+            ret = chown(name, uid, gid);
+            if (ret < 0) {
+                *x = '/';
+                return ret;
+            }
+            selinux_android_restorecon(name);
         }
         *x++ = '/';
     }
@@ -149,7 +172,8 @@ static int fail_errno(int s)
     return fail_message(s, strerror(errno));
 }
 
-static int handle_send_file(int s, char *path, mode_t mode, char *buffer)
+static int handle_send_file(int s, char *path, unsigned int uid,
+        unsigned int gid, mode_t mode, char *buffer)
 {
     syncmsg msg;
     unsigned int timestamp = 0;
@@ -157,8 +181,13 @@ static int handle_send_file(int s, char *path, mode_t mode, char *buffer)
 
     fd = adb_open_mode(path, O_WRONLY | O_CREAT | O_EXCL, mode);
     if(fd < 0 && errno == ENOENT) {
-        mkdirs(path);
-        fd = adb_open_mode(path, O_WRONLY | O_CREAT | O_EXCL, mode);
+        if(mkdirs(path) != 0) {
+            if(fail_errno(s))
+                return -1;
+            fd = -1;
+        } else {
+            fd = adb_open_mode(path, O_WRONLY | O_CREAT | O_EXCL, mode);
+        }
     }
     if(fd < 0 && errno == EEXIST) {
         fd = adb_open_mode(path, O_WRONLY, mode);
@@ -167,6 +196,16 @@ static int handle_send_file(int s, char *path, mode_t mode, char *buffer)
         if(fail_errno(s))
             return -1;
         fd = -1;
+    } else {
+        if(fchown(fd, uid, gid) != 0) {
+            fail_errno(s);
+            errno = 0;
+        }
+        /* fchown clears the setuid bit - restore it if present */
+        if(fchmod(fd, mode) != 0) {
+            fail_errno(s);
+            errno = 0;
+        }
     }
 
     for(;;) {
@@ -206,6 +245,7 @@ static int handle_send_file(int s, char *path, mode_t mode, char *buffer)
     if(fd >= 0) {
         struct utimbuf u;
         adb_close(fd);
+        selinux_android_restorecon(path);
         u.actime = timestamp;
         u.modtime = timestamp;
         utime(path, &u);
@@ -249,7 +289,10 @@ static int handle_send_link(int s, char *path, char *buffer)
 
     ret = symlink(buffer, path);
     if(ret && errno == ENOENT) {
-        mkdirs(path);
+        if(mkdirs(path) != 0) {
+            fail_errno(s);
+            return -1;
+        }
         ret = symlink(buffer, path);
     }
     if(ret) {
@@ -277,7 +320,7 @@ static int handle_send_link(int s, char *path, char *buffer)
 static int do_send(int s, char *path, char *buffer)
 {
     char *tmp;
-    mode_t mode;
+    unsigned int mode;
     int is_link, ret;
 
     tmp = strrchr(path,',');
@@ -288,7 +331,7 @@ static int do_send(int s, char *path, char *buffer)
 #ifndef HAVE_SYMLINKS
         is_link = 0;
 #else
-        is_link = S_ISLNK(mode);
+        is_link = S_ISLNK((mode_t) mode);
 #endif
         mode &= 0777;
     }
@@ -307,11 +350,23 @@ static int do_send(int s, char *path, char *buffer)
 #else
     {
 #endif
+        unsigned int uid, gid;
+        uint64_t cap = 0;
+        uid = getuid();
+        gid = getgid();
+
         /* copy user permission bits to "group" and "other" permissions */
         mode |= ((mode >> 3) & 0070);
         mode |= ((mode >> 3) & 0007);
 
-        ret = handle_send_file(s, path, mode, buffer);
+        tmp = path;
+        if(*tmp == '/') {
+            tmp++;
+        }
+        if (is_on_system(path)) {
+            fs_config(tmp, 0, &uid, &gid, &mode, &cap);
+        }
+        ret = handle_send_file(s, path, uid, gid, mode, buffer);
     }
 
     return ret;