Implement system data migration support.

This adds three new features:

- <original-package android:name="com.foo" /> manifest tag.
  This allows an .apk to specify another package it originally came from,
  propagating all state and data from the old to new package.

- <adopt-permissions android:name="com.foo" /> manifest tag.
  In some more complicated cases, a new .apk may be a combination
  of multiple older .apks that each declared their own permissions.
  This allows you to propagate the permissions from these other
  .apks into the new one.

- A new system/etc/updatecmds directory.
  You can place files here which describe data files to move from
  one package to another.  (See below for details.)

Also in this change: we now clean up the data directories of
.apks that disappear from the system image, and some improvements
to logging and reporting error messages.

A typical file in the updatecmds directory looks like this:

-------
com.google.android.gsf:com.google.android.providers.talk
    databases/talk.db
com.google.android.gsf:com.google.android.googleapps
    databases/gls.db
-------

This says that for com.google.android.sfs, there are two packages to
move files from:

From com.google.android.providers.talk, the file databases/talk.db.
From com.google.android.googleapps, the file databases/gls.db

As part of moving the file, its owner will be changed from the old
package to whoever is the owner of the new package's data directory.

If those two files had existed, after booting you would now have the
files:

/data/data/com.google.android.gsf/databases/talk.db
/data/data/com.google.android.gsf/databases/gls.db

Note that all three of these facilities assume that the older .apk
is completely removed from the newer system.  The WILL NOT work
correctly if the older .apk still remains.

1 files changed, 224 insertions, 0 deletions

diff --git a/cmds/installd/commands.c b/cmds/installd/commands.c
index 79bda74..1e8555b 100644
--- a/cmds/installd/commands.c
+++ b/cmds/installd/commands.c
@@ -78,6 +78,30 @@ int uninstall(const char *pkgname, int encrypted_fs_flag)
     return delete_dir_contents(pkgdir, 1, 0);
 }
 
+int renamepkg(const char *oldpkgname, const char *newpkgname, int encrypted_fs_flag)
+{
+    char oldpkgdir[PKG_PATH_MAX];
+    char newpkgdir[PKG_PATH_MAX];
+
+    if (encrypted_fs_flag == USE_UNENCRYPTED_FS) {
+        if (create_pkg_path(oldpkgdir, PKG_DIR_PREFIX, oldpkgname, PKG_DIR_POSTFIX))
+            return -1;
+        if (create_pkg_path(newpkgdir, PKG_DIR_PREFIX, newpkgname, PKG_DIR_POSTFIX))
+            return -1;
+    } else {
+        if (create_pkg_path(oldpkgdir, PKG_SEC_DIR_PREFIX, oldpkgname, PKG_DIR_POSTFIX))
+            return -1;
+        if (create_pkg_path(newpkgdir, PKG_SEC_DIR_PREFIX, newpkgname, PKG_DIR_POSTFIX))
+            return -1;
+    }
+
+    if (rename(oldpkgdir, newpkgdir) < 0) {
+        LOGE("cannot rename dir '%s' to '%s': %s\n", oldpkgdir, newpkgdir, strerror(errno));
+        return -errno;
+    }
+    return 0;
+}
+
 int delete_user_data(const char *pkgname, int encrypted_fs_flag)
 {
     char pkgdir[PKG_PATH_MAX];
@@ -636,3 +660,203 @@ fail:
     }
     return -1;
 }
+
+int create_move_path(char path[PKG_PATH_MAX],
+    const char* prefix,
+    const char* pkgname,
+    const char* leaf)
+{
+    if ((strlen(prefix) + strlen(pkgname) + strlen(leaf) + 1) >= PKG_PATH_MAX) {
+        return -1;
+    }
+    
+    sprintf(path, "%s%s/%s", prefix, pkgname, leaf);
+    return 0;
+}
+
+void mkinnerdirs(char* path, int basepos, mode_t mode, int uid, int gid)
+{
+    while (path[basepos] != 0) {
+        if (path[basepos] == '/') {
+            path[basepos] = 0;
+            LOGI("Making directory: %s\n", path);
+            if (mkdir(path, mode) == 0) {
+                chown(path, uid, gid);
+            }
+            path[basepos] = '/';
+            basepos++;
+        }
+        basepos++;
+    }
+}
+
+int movefiles()
+{
+    DIR *d;
+    int dfd, subfd;
+    struct dirent *de;
+    struct stat s;
+    char buf[PKG_PATH_MAX+1];
+    int bufp, bufe, bufi, readlen;
+
+    char srcpkg[PKG_NAME_MAX];
+    char dstpkg[PKG_NAME_MAX];
+    char srcpath[PKG_PATH_MAX];
+    char dstpath[PKG_PATH_MAX];
+    int dstuid, dstgid;
+    int hasspace;
+
+    d = opendir(UPDATE_COMMANDS_DIR_PREFIX);
+    if (d == NULL) {
+        goto done;
+    }
+    dfd = dirfd(d);
+
+        /* Iterate through all files in the directory, executing the
+         * file movements requested there-in.
+         */
+    while ((de = readdir(d))) {
+        const char *name = de->d_name;
+
+        if (de->d_type == DT_DIR) {
+            continue;
+        } else {
+            subfd = openat(dfd, name, O_RDONLY);
+            if (subfd < 0) {
+                LOGW("Unable to open update commands at %s%s\n",
+                        UPDATE_COMMANDS_DIR_PREFIX, name);
+                continue;
+            }
+            
+            bufp = 0;
+            bufe = 0;
+            buf[PKG_PATH_MAX] = 0;
+            srcpkg[0] = dstpkg[0] = 0;
+            while (1) {
+                bufi = bufp;
+                while (bufi < bufe && buf[bufi] != '\n') {
+                    bufi++;
+                }
+                if (bufi < bufe) {
+                    buf[bufi] = 0;
+                    LOGV("Processing line: %s\n", buf+bufp);
+                    hasspace = 0;
+                    while (bufp < bufi && isspace(buf[bufp])) {
+                        hasspace = 1;
+                        bufp++;
+                    }
+                    if (buf[bufp] == '#' || bufp == bufi) {
+                        // skip comments and empty lines.
+                    } else if (hasspace) {
+                        if (dstpkg[0] == 0) {
+                            LOGW("Path before package line in %s%s: %s\n",
+                                    UPDATE_COMMANDS_DIR_PREFIX, name, buf+bufp);
+                        } else if (srcpkg[0] == 0) {
+                            // Skip -- source package no longer exists.
+                        } else {
+                            LOGV("Move file: %s (from %s to %s)\n", buf+bufp, srcpkg, dstpkg);
+                            if (!create_move_path(srcpath, PKG_DIR_PREFIX, srcpkg, buf+bufp) &&
+                                    !create_move_path(dstpath, PKG_DIR_PREFIX, dstpkg, buf+bufp)) {
+                                LOGI("Renaming %s to %s (uid %d)\n", srcpath, dstpath, dstuid);
+                                mkinnerdirs(dstpath, strlen(dstpath)-(bufi-bufp),
+                                    S_IRWXU|S_IRWXG|S_IXOTH, dstuid, dstgid);
+                                if (rename(srcpath, dstpath) >= 0) {
+                                    if (chown(dstpath, dstuid, dstgid) < 0) {
+                                        LOGE("cannot chown %s: %s\n", dstpath, strerror(errno));
+                                        unlink(dstpath);
+                                    }
+                                } else {
+                                    LOGW("Unable to rename %s to %s: %s\n",
+                                        srcpath, dstpath, strerror(errno));
+                                }
+                            }
+                        }
+                    } else {
+                        char* div = strchr(buf+bufp, ':');
+                        if (div == NULL) {
+                            LOGW("Bad package spec in %s%s; no ':' sep: %s\n",
+                                    UPDATE_COMMANDS_DIR_PREFIX, name, buf+bufp);
+                        } else {
+                            *div = 0;
+                            div++;
+                            if (strlen(buf+bufp) < PKG_NAME_MAX) {
+                                strcpy(dstpkg, buf+bufp);
+                            } else {
+                                srcpkg[0] = dstpkg[0] = 0;
+                                LOGW("Package name too long in %s%s: %s\n",
+                                        UPDATE_COMMANDS_DIR_PREFIX, name, buf+bufp);
+                            }
+                            if (strlen(div) < PKG_NAME_MAX) {
+                                strcpy(srcpkg, div);
+                            } else {
+                                srcpkg[0] = dstpkg[0] = 0;
+                                LOGW("Package name too long in %s%s: %s\n",
+                                        UPDATE_COMMANDS_DIR_PREFIX, name, div);
+                            }
+                            if (srcpkg[0] != 0) {
+                                if (!create_pkg_path(srcpath, PKG_DIR_PREFIX, srcpkg,
+                                        PKG_DIR_POSTFIX)) {
+                                    if (lstat(srcpath, &s) < 0) {
+                                        // Package no longer exists -- skip.
+                                        srcpkg[0] = 0;
+                                    }
+                                } else {
+                                    srcpkg[0] = 0;
+                                    LOGW("Can't create path %s in %s%s\n",
+                                            div, UPDATE_COMMANDS_DIR_PREFIX, name);
+                                }
+                                if (srcpkg[0] != 0) {
+                                    if (!create_pkg_path(dstpath, PKG_DIR_PREFIX, dstpkg,
+                                            PKG_DIR_POSTFIX)) {
+                                        if (lstat(dstpath, &s) == 0) {
+                                            dstuid = s.st_uid;
+                                            dstgid = s.st_gid;
+                                        } else {
+                                            srcpkg[0] = 0;
+                                            LOGW("Can't stat path %s in %s%s: %s\n",
+                                                    dstpath, UPDATE_COMMANDS_DIR_PREFIX,
+                                                    name, strerror(errno));
+                                        }
+                                    } else {
+                                        srcpkg[0] = 0;
+                                        LOGW("Can't create path %s in %s%s\n",
+                                                div, UPDATE_COMMANDS_DIR_PREFIX, name);
+                                    }
+                                }
+                                LOGV("Transfering from %s to %s: uid=%d\n",
+                                    srcpkg, dstpkg, dstuid);
+                            }
+                        }
+                    }
+                    bufp = bufi+1;
+                } else {
+                    if (bufp == 0) {
+                        if (bufp < bufe) {
+                            LOGW("Line too long in %s%s, skipping: %s\n",
+                                    UPDATE_COMMANDS_DIR_PREFIX, name, buf);
+                        }
+                    } else if (bufp < bufe) {
+                        memcpy(buf, buf+bufp, bufe-bufp);
+                        bufe -= bufp;
+                        bufp = 0;
+                    }
+                    readlen = read(subfd, buf+bufe, PKG_PATH_MAX-bufe);
+                    if (readlen < 0) {
+                        LOGW("Failure reading update commands in %s%s: %s\n",
+                                UPDATE_COMMANDS_DIR_PREFIX, name, strerror(errno));
+                        break;
+                    } else if (readlen == 0) {
+                        break;
+                    }
+                    bufe += readlen;
+                    buf[bufe] = 0;
+                    LOGV("Read buf: %s\n", buf);
+                }
+            }
+            close(subfd);
+        }
+    }
+    closedir(d);
+done:
+    return 0;
+}