1 files changed, 1622 insertions, 0 deletions

diff --git a/updater/install.cpp b/updater/install.cpp
new file mode 100644
index 000000000..422a1bb1e
--- /dev/null
+++ b/updater/install.cpp
@@ -0,0 +1,1622 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <time.h>
+#include <selinux/selinux.h>
+#include <ftw.h>
+#include <sys/capability.h>
+#include <sys/xattr.h>
+#include <linux/xattr.h>
+#include <inttypes.h>
+
+#include "bootloader.h"
+#include "applypatch/applypatch.h"
+#include "cutils/android_reboot.h"
+#include "cutils/misc.h"
+#include "cutils/properties.h"
+#include "edify/expr.h"
+#include "mincrypt/sha.h"
+#include "minzip/DirUtil.h"
+#include "mtdutils/mounts.h"
+#include "mtdutils/mtdutils.h"
+#include "updater.h"
+#include "install.h"
+#include "tune2fs.h"
+
+#ifdef USE_EXT4
+#include "make_ext4fs.h"
+#include "wipe.h"
+#endif
+
+void uiPrint(State* state, char* buffer) {
+    char* line = strtok(buffer, "\n");
+    UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
+    while (line) {
+        fprintf(ui->cmd_pipe, "ui_print %s\n", line);
+        line = strtok(NULL, "\n");
+    }
+    fprintf(ui->cmd_pipe, "ui_print\n");
+
+    // The recovery will only print the contents to screen for pipe command
+    // ui_print. We need to dump the contents to stderr (which has been
+    // redirected to the log file) directly.
+    fprintf(stderr, "%s", buffer);
+}
+
+__attribute__((__format__(printf, 2, 3))) __nonnull((2))
+void uiPrintf(State* state, const char* format, ...) {
+    char error_msg[1024];
+    va_list ap;
+    va_start(ap, format);
+    vsnprintf(error_msg, sizeof(error_msg), format, ap);
+    va_end(ap);
+    uiPrint(state, error_msg);
+}
+
+// Take a sha-1 digest and return it as a newly-allocated hex string.
+char* PrintSha1(const uint8_t* digest) {
+    char* buffer = reinterpret_cast<char*>(malloc(SHA_DIGEST_SIZE*2 + 1));
+    const char* alphabet = "0123456789abcdef";
+    size_t i;
+    for (i = 0; i < SHA_DIGEST_SIZE; ++i) {
+        buffer[i*2] = alphabet[(digest[i] >> 4) & 0xf];
+        buffer[i*2+1] = alphabet[digest[i] & 0xf];
+    }
+    buffer[i*2] = '\0';
+    return buffer;
+}
+
+// mount(fs_type, partition_type, location, mount_point)
+//
+//    fs_type="yaffs2" partition_type="MTD"     location=partition
+//    fs_type="ext4"   partition_type="EMMC"    location=device
+Value* MountFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char* result = NULL;
+    if (argc != 4 && argc != 5) {
+        return ErrorAbort(state, "%s() expects 4-5 args, got %d", name, argc);
+    }
+    char* fs_type;
+    char* partition_type;
+    char* location;
+    char* mount_point;
+    char* mount_options;
+    bool has_mount_options;
+    if (argc == 5) {
+        has_mount_options = true;
+        if (ReadArgs(state, argv, 5, &fs_type, &partition_type,
+                 &location, &mount_point, &mount_options) < 0) {
+            return NULL;
+        }
+    } else {
+        has_mount_options = false;
+        if (ReadArgs(state, argv, 4, &fs_type, &partition_type,
+                 &location, &mount_point) < 0) {
+            return NULL;
+        }
+    }
+
+    if (strlen(fs_type) == 0) {
+        ErrorAbort(state, "fs_type argument to %s() can't be empty", name);
+        goto done;
+    }
+    if (strlen(partition_type) == 0) {
+        ErrorAbort(state, "partition_type argument to %s() can't be empty",
+                   name);
+        goto done;
+    }
+    if (strlen(location) == 0) {
+        ErrorAbort(state, "location argument to %s() can't be empty", name);
+        goto done;
+    }
+    if (strlen(mount_point) == 0) {
+        ErrorAbort(state, "mount_point argument to %s() can't be empty", name);
+        goto done;
+    }
+
+    {
+        char *secontext = NULL;
+
+        if (sehandle) {
+            selabel_lookup(sehandle, &secontext, mount_point, 0755);
+            setfscreatecon(secontext);
+        }
+
+        mkdir(mount_point, 0755);
+
+        if (secontext) {
+            freecon(secontext);
+            setfscreatecon(NULL);
+        }
+    }
+
+    if (strcmp(partition_type, "MTD") == 0) {
+        mtd_scan_partitions();
+        const MtdPartition* mtd;
+        mtd = mtd_find_partition_by_name(location);
+        if (mtd == NULL) {
+            uiPrintf(state, "%s: no mtd partition named \"%s\"",
+                    name, location);
+            result = strdup("");
+            goto done;
+        }
+        if (mtd_mount_partition(mtd, mount_point, fs_type, 0 /* rw */) != 0) {
+            uiPrintf(state, "mtd mount of %s failed: %s\n",
+                    location, strerror(errno));
+            result = strdup("");
+            goto done;
+        }
+        result = mount_point;
+    } else {
+        if (mount(location, mount_point, fs_type,
+                  MS_NOATIME | MS_NODEV | MS_NODIRATIME,
+                  has_mount_options ? mount_options : "") < 0) {
+            uiPrintf(state, "%s: failed to mount %s at %s: %s\n",
+                    name, location, mount_point, strerror(errno));
+            result = strdup("");
+        } else {
+            result = mount_point;
+        }
+    }
+
+done:
+    free(fs_type);
+    free(partition_type);
+    free(location);
+    if (result != mount_point) free(mount_point);
+    if (has_mount_options) free(mount_options);
+    return StringValue(result);
+}
+
+
+// is_mounted(mount_point)
+Value* IsMountedFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char* result = NULL;
+    if (argc != 1) {
+        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+    }
+    char* mount_point;
+    if (ReadArgs(state, argv, 1, &mount_point) < 0) {
+        return NULL;
+    }
+    if (strlen(mount_point) == 0) {
+        ErrorAbort(state, "mount_point argument to unmount() can't be empty");
+        goto done;
+    }
+
+    scan_mounted_volumes();
+    {
+        const MountedVolume* vol = find_mounted_volume_by_mount_point(mount_point);
+        if (vol == NULL) {
+            result = strdup("");
+        } else {
+            result = mount_point;
+        }
+    }
+
+done:
+    if (result != mount_point) free(mount_point);
+    return StringValue(result);
+}
+
+
+Value* UnmountFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char* result = NULL;
+    if (argc != 1) {
+        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+    }
+    char* mount_point;
+    if (ReadArgs(state, argv, 1, &mount_point) < 0) {
+        return NULL;
+    }
+    if (strlen(mount_point) == 0) {
+        ErrorAbort(state, "mount_point argument to unmount() can't be empty");
+        goto done;
+    }
+
+    scan_mounted_volumes();
+    {
+        const MountedVolume* vol = find_mounted_volume_by_mount_point(mount_point);
+        if (vol == NULL) {
+            uiPrintf(state, "unmount of %s failed; no such volume\n", mount_point);
+            result = strdup("");
+        } else {
+            int ret = unmount_mounted_volume(vol);
+            if (ret != 0) {
+                uiPrintf(state, "unmount of %s failed (%d): %s\n",
+                         mount_point, ret, strerror(errno));
+            }
+            result = mount_point;
+        }
+    }
+
+done:
+    if (result != mount_point) free(mount_point);
+    return StringValue(result);
+}
+
+static int exec_cmd(const char* path, char* const argv[]) {
+    int status;
+    pid_t child;
+    if ((child = vfork()) == 0) {
+        execv(path, argv);
+        _exit(-1);
+    }
+    waitpid(child, &status, 0);
+    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+        printf("%s failed with status %d\n", path, WEXITSTATUS(status));
+    }
+    return WEXITSTATUS(status);
+}
+
+
+// format(fs_type, partition_type, location, fs_size, mount_point)
+//
+//    fs_type="yaffs2" partition_type="MTD"     location=partition fs_size=<bytes> mount_point=<location>
+//    fs_type="ext4"   partition_type="EMMC"    location=device    fs_size=<bytes> mount_point=<location>
+//    fs_type="f2fs"   partition_type="EMMC"    location=device    fs_size=<bytes> mount_point=<location>
+//    if fs_size == 0, then make fs uses the entire partition.
+//    if fs_size > 0, that is the size to use
+//    if fs_size < 0, then reserve that many bytes at the end of the partition (not for "f2fs")
+Value* FormatFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char* result = NULL;
+    if (argc != 5) {
+        return ErrorAbort(state, "%s() expects 5 args, got %d", name, argc);
+    }
+    char* fs_type;
+    char* partition_type;
+    char* location;
+    char* fs_size;
+    char* mount_point;
+
+    if (ReadArgs(state, argv, 5, &fs_type, &partition_type, &location, &fs_size, &mount_point) < 0) {
+        return NULL;
+    }
+
+    if (strlen(fs_type) == 0) {
+        ErrorAbort(state, "fs_type argument to %s() can't be empty", name);
+        goto done;
+    }
+    if (strlen(partition_type) == 0) {
+        ErrorAbort(state, "partition_type argument to %s() can't be empty",
+                   name);
+        goto done;
+    }
+    if (strlen(location) == 0) {
+        ErrorAbort(state, "location argument to %s() can't be empty", name);
+        goto done;
+    }
+
+    if (strlen(mount_point) == 0) {
+        ErrorAbort(state, "mount_point argument to %s() can't be empty", name);
+        goto done;
+    }
+
+    if (strcmp(partition_type, "MTD") == 0) {
+        mtd_scan_partitions();
+        const MtdPartition* mtd = mtd_find_partition_by_name(location);
+        if (mtd == NULL) {
+            printf("%s: no mtd partition named \"%s\"",
+                    name, location);
+            result = strdup("");
+            goto done;
+        }
+        MtdWriteContext* ctx = mtd_write_partition(mtd);
+        if (ctx == NULL) {
+            printf("%s: can't write \"%s\"", name, location);
+            result = strdup("");
+            goto done;
+        }
+        if (mtd_erase_blocks(ctx, -1) == -1) {
+            mtd_write_close(ctx);
+            printf("%s: failed to erase \"%s\"", name, location);
+            result = strdup("");
+            goto done;
+        }
+        if (mtd_write_close(ctx) != 0) {
+            printf("%s: failed to close \"%s\"", name, location);
+            result = strdup("");
+            goto done;
+        }
+        result = location;
+#ifdef USE_EXT4
+    } else if (strcmp(fs_type, "ext4") == 0) {
+        int status = make_ext4fs(location, atoll(fs_size), mount_point, sehandle);
+        if (status != 0) {
+            printf("%s: make_ext4fs failed (%d) on %s",
+                    name, status, location);
+            result = strdup("");
+            goto done;
+        }
+        result = location;
+    } else if (strcmp(fs_type, "f2fs") == 0) {
+        char *num_sectors;
+        if (asprintf(&num_sectors, "%lld", atoll(fs_size) / 512) <= 0) {
+            printf("format_volume: failed to create %s command for %s\n", fs_type, location);
+            result = strdup("");
+            goto done;
+        }
+        const char *f2fs_path = "/sbin/mkfs.f2fs";
+        const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", location, num_sectors, NULL};
+        int status = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
+        free(num_sectors);
+        if (status != 0) {
+            printf("%s: mkfs.f2fs failed (%d) on %s",
+                    name, status, location);
+            result = strdup("");
+            goto done;
+        }
+        result = location;
+#endif
+    } else {
+        printf("%s: unsupported fs_type \"%s\" partition_type \"%s\"",
+                name, fs_type, partition_type);
+    }
+
+done:
+    free(fs_type);
+    free(partition_type);
+    if (result != location) free(location);
+    return StringValue(result);
+}
+
+Value* RenameFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char* result = NULL;
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+
+    char* src_name;
+    char* dst_name;
+
+    if (ReadArgs(state, argv, 2, &src_name, &dst_name) < 0) {
+        return NULL;
+    }
+    if (strlen(src_name) == 0) {
+        ErrorAbort(state, "src_name argument to %s() can't be empty", name);
+        goto done;
+    }
+    if (strlen(dst_name) == 0) {
+        ErrorAbort(state, "dst_name argument to %s() can't be empty", name);
+        goto done;
+    }
+    if (make_parents(dst_name) != 0) {
+        ErrorAbort(state, "Creating parent of %s failed, error %s",
+          dst_name, strerror(errno));
+    } else if (access(dst_name, F_OK) == 0 && access(src_name, F_OK) != 0) {
+        // File was already moved
+        result = dst_name;
+    } else if (rename(src_name, dst_name) != 0) {
+        ErrorAbort(state, "Rename of %s to %s failed, error %s",
+          src_name, dst_name, strerror(errno));
+    } else {
+        result = dst_name;
+    }
+
+done:
+    free(src_name);
+    if (result != dst_name) free(dst_name);
+    return StringValue(result);
+}
+
+Value* DeleteFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char** paths = reinterpret_cast<char**>(malloc(argc * sizeof(char*)));
+    for (int i = 0; i < argc; ++i) {
+        paths[i] = Evaluate(state, argv[i]);
+        if (paths[i] == NULL) {
+            int j;
+            for (j = 0; j < i; ++i) {
+                free(paths[j]);
+            }
+            free(paths);
+            return NULL;
+        }
+    }
+
+    bool recursive = (strcmp(name, "delete_recursive") == 0);
+
+    int success = 0;
+    for (int i = 0; i < argc; ++i) {
+        if ((recursive ? dirUnlinkHierarchy(paths[i]) : unlink(paths[i])) == 0)
+            ++success;
+        free(paths[i]);
+    }
+    free(paths);
+
+    char buffer[10];
+    sprintf(buffer, "%d", success);
+    return StringValue(strdup(buffer));
+}
+
+
+Value* ShowProgressFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+    char* frac_str;
+    char* sec_str;
+    if (ReadArgs(state, argv, 2, &frac_str, &sec_str) < 0) {
+        return NULL;
+    }
+
+    double frac = strtod(frac_str, NULL);
+    int sec = strtol(sec_str, NULL, 10);
+
+    UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
+    fprintf(ui->cmd_pipe, "progress %f %d\n", frac, sec);
+
+    free(sec_str);
+    return StringValue(frac_str);
+}
+
+Value* SetProgressFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 1) {
+        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+    }
+    char* frac_str;
+    if (ReadArgs(state, argv, 1, &frac_str) < 0) {
+        return NULL;
+    }
+
+    double frac = strtod(frac_str, NULL);
+
+    UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
+    fprintf(ui->cmd_pipe, "set_progress %f\n", frac);
+
+    return StringValue(frac_str);
+}
+
+// package_extract_dir(package_path, destination_path)
+Value* PackageExtractDirFn(const char* name, State* state,
+                          int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+    char* zip_path;
+    char* dest_path;
+    if (ReadArgs(state, argv, 2, &zip_path, &dest_path) < 0) return NULL;
+
+    ZipArchive* za = ((UpdaterInfo*)(state->cookie))->package_zip;
+
+    // To create a consistent system image, never use the clock for timestamps.
+    struct utimbuf timestamp = { 1217592000, 1217592000 };  // 8/1/2008 default
+
+    bool success = mzExtractRecursive(za, zip_path, dest_path,
+                                      &timestamp,
+                                      NULL, NULL, sehandle);
+    free(zip_path);
+    free(dest_path);
+    return StringValue(strdup(success ? "t" : ""));
+}
+
+
+// package_extract_file(package_path, destination_path)
+//   or
+// package_extract_file(package_path)
+//   to return the entire contents of the file as the result of this
+//   function (the char* returned is actually a FileContents*).
+Value* PackageExtractFileFn(const char* name, State* state,
+                           int argc, Expr* argv[]) {
+    if (argc < 1 || argc > 2) {
+        return ErrorAbort(state, "%s() expects 1 or 2 args, got %d",
+                          name, argc);
+    }
+    bool success = false;
+
+    if (argc == 2) {
+        // The two-argument version extracts to a file.
+
+        ZipArchive* za = ((UpdaterInfo*)(state->cookie))->package_zip;
+
+        char* zip_path;
+        char* dest_path;
+        if (ReadArgs(state, argv, 2, &zip_path, &dest_path) < 0) return NULL;
+
+        const ZipEntry* entry = mzFindZipEntry(za, zip_path);
+        if (entry == NULL) {
+            printf("%s: no %s in package\n", name, zip_path);
+            goto done2;
+        }
+
+        {
+            FILE* f = fopen(dest_path, "wb");
+            if (f == NULL) {
+                printf("%s: can't open %s for write: %s\n",
+                        name, dest_path, strerror(errno));
+                goto done2;
+            }
+            success = mzExtractZipEntryToFile(za, entry, fileno(f));
+            fclose(f);
+        }
+
+      done2:
+        free(zip_path);
+        free(dest_path);
+        return StringValue(strdup(success ? "t" : ""));
+    } else {
+        // The one-argument version returns the contents of the file
+        // as the result.
+
+        char* zip_path;
+        Value* v = reinterpret_cast<Value*>(malloc(sizeof(Value)));
+        v->type = VAL_BLOB;
+        v->size = -1;
+        v->data = NULL;
+
+        if (ReadArgs(state, argv, 1, &zip_path) < 0) return NULL;
+
+        ZipArchive* za = ((UpdaterInfo*)(state->cookie))->package_zip;
+        const ZipEntry* entry = mzFindZipEntry(za, zip_path);
+        if (entry == NULL) {
+            printf("%s: no %s in package\n", name, zip_path);
+            goto done1;
+        }
+
+        v->size = mzGetZipEntryUncompLen(entry);
+        v->data = reinterpret_cast<char*>(malloc(v->size));
+        if (v->data == NULL) {
+            printf("%s: failed to allocate %ld bytes for %s\n",
+                    name, (long)v->size, zip_path);
+            goto done1;
+        }
+
+        success = mzExtractZipEntryToBuffer(za, entry,
+                                            (unsigned char *)v->data);
+
+      done1:
+        free(zip_path);
+        if (!success) {
+            free(v->data);
+            v->data = NULL;
+            v->size = -1;
+        }
+        return v;
+    }
+}
+
+// Create all parent directories of name, if necessary.
+static int make_parents(char* name) {
+    char* p;
+    for (p = name + (strlen(name)-1); p > name; --p) {
+        if (*p != '/') continue;
+        *p = '\0';
+        if (make_parents(name) < 0) return -1;
+        int result = mkdir(name, 0700);
+        if (result == 0) printf("created [%s]\n", name);
+        *p = '/';
+        if (result == 0 || errno == EEXIST) {
+            // successfully created or already existed; we're done
+            return 0;
+        } else {
+            printf("failed to mkdir %s: %s\n", name, strerror(errno));
+            return -1;
+        }
+    }
+    return 0;
+}
+
+// symlink target src1 src2 ...
+//    unlinks any previously existing src1, src2, etc before creating symlinks.
+Value* SymlinkFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc == 0) {
+        return ErrorAbort(state, "%s() expects 1+ args, got %d", name, argc);
+    }
+    char* target;
+    target = Evaluate(state, argv[0]);
+    if (target == NULL) return NULL;
+
+    char** srcs = ReadVarArgs(state, argc-1, argv+1);
+    if (srcs == NULL) {
+        free(target);
+        return NULL;
+    }
+
+    int bad = 0;
+    int i;
+    for (i = 0; i < argc-1; ++i) {
+        if (unlink(srcs[i]) < 0) {
+            if (errno != ENOENT) {
+                printf("%s: failed to remove %s: %s\n",
+                        name, srcs[i], strerror(errno));
+                ++bad;
+            }
+        }
+        if (make_parents(srcs[i])) {
+            printf("%s: failed to symlink %s to %s: making parents failed\n",
+                    name, srcs[i], target);
+            ++bad;
+        }
+        if (symlink(target, srcs[i]) < 0) {
+            printf("%s: failed to symlink %s to %s: %s\n",
+                    name, srcs[i], target, strerror(errno));
+            ++bad;
+        }
+        free(srcs[i]);
+    }
+    free(srcs);
+    if (bad) {
+        return ErrorAbort(state, "%s: some symlinks failed", name);
+    }
+    return StringValue(strdup(""));
+}
+
+struct perm_parsed_args {
+    bool has_uid;
+    uid_t uid;
+    bool has_gid;
+    gid_t gid;
+    bool has_mode;
+    mode_t mode;
+    bool has_fmode;
+    mode_t fmode;
+    bool has_dmode;
+    mode_t dmode;
+    bool has_selabel;
+    char* selabel;
+    bool has_capabilities;
+    uint64_t capabilities;
+};
+
+static struct perm_parsed_args ParsePermArgs(State * state, int argc, char** args) {
+    int i;
+    struct perm_parsed_args parsed;
+    int bad = 0;
+    static int max_warnings = 20;
+
+    memset(&parsed, 0, sizeof(parsed));
+
+    for (i = 1; i < argc; i += 2) {
+        if (strcmp("uid", args[i]) == 0) {
+            int64_t uid;
+            if (sscanf(args[i+1], "%" SCNd64, &uid) == 1) {
+                parsed.uid = uid;
+                parsed.has_uid = true;
+            } else {
+                uiPrintf(state, "ParsePermArgs: invalid UID \"%s\"\n", args[i + 1]);
+                bad++;
+            }
+            continue;
+        }
+        if (strcmp("gid", args[i]) == 0) {
+            int64_t gid;
+            if (sscanf(args[i+1], "%" SCNd64, &gid) == 1) {
+                parsed.gid = gid;
+                parsed.has_gid = true;
+            } else {
+                uiPrintf(state, "ParsePermArgs: invalid GID \"%s\"\n", args[i + 1]);
+                bad++;
+            }
+            continue;
+        }
+        if (strcmp("mode", args[i]) == 0) {
+            int32_t mode;
+            if (sscanf(args[i+1], "%" SCNi32, &mode) == 1) {
+                parsed.mode = mode;
+                parsed.has_mode = true;
+            } else {
+                uiPrintf(state, "ParsePermArgs: invalid mode \"%s\"\n", args[i + 1]);
+                bad++;
+            }
+            continue;
+        }
+        if (strcmp("dmode", args[i]) == 0) {
+            int32_t mode;
+            if (sscanf(args[i+1], "%" SCNi32, &mode) == 1) {
+                parsed.dmode = mode;
+                parsed.has_dmode = true;
+            } else {
+                uiPrintf(state, "ParsePermArgs: invalid dmode \"%s\"\n", args[i + 1]);
+                bad++;
+            }
+            continue;
+        }
+        if (strcmp("fmode", args[i]) == 0) {
+            int32_t mode;
+            if (sscanf(args[i+1], "%" SCNi32, &mode) == 1) {
+                parsed.fmode = mode;
+                parsed.has_fmode = true;
+            } else {
+                uiPrintf(state, "ParsePermArgs: invalid fmode \"%s\"\n", args[i + 1]);
+                bad++;
+            }
+            continue;
+        }
+        if (strcmp("capabilities", args[i]) == 0) {
+            int64_t capabilities;
+            if (sscanf(args[i+1], "%" SCNi64, &capabilities) == 1) {
+                parsed.capabilities = capabilities;
+                parsed.has_capabilities = true;
+            } else {
+                uiPrintf(state, "ParsePermArgs: invalid capabilities \"%s\"\n", args[i + 1]);
+                bad++;
+            }
+            continue;
+        }
+        if (strcmp("selabel", args[i]) == 0) {
+            if (args[i+1][0] != '\0') {
+                parsed.selabel = args[i+1];
+                parsed.has_selabel = true;
+            } else {
+                uiPrintf(state, "ParsePermArgs: invalid selabel \"%s\"\n", args[i + 1]);
+                bad++;
+            }
+            continue;
+        }
+        if (max_warnings != 0) {
+            printf("ParsedPermArgs: unknown key \"%s\", ignoring\n", args[i]);
+            max_warnings--;
+            if (max_warnings == 0) {
+                printf("ParsedPermArgs: suppressing further warnings\n");
+            }
+        }
+    }
+    return parsed;
+}
+
+static int ApplyParsedPerms(
+        State * state,
+        const char* filename,
+        const struct stat *statptr,
+        struct perm_parsed_args parsed)
+{
+    int bad = 0;
+
+    if (parsed.has_selabel) {
+        if (lsetfilecon(filename, parsed.selabel) != 0) {
+            uiPrintf(state, "ApplyParsedPerms: lsetfilecon of %s to %s failed: %s\n",
+                    filename, parsed.selabel, strerror(errno));
+            bad++;
+        }
+    }
+
+    /* ignore symlinks */
+    if (S_ISLNK(statptr->st_mode)) {
+        return bad;
+    }
+
+    if (parsed.has_uid) {
+        if (chown(filename, parsed.uid, -1) < 0) {
+            uiPrintf(state, "ApplyParsedPerms: chown of %s to %d failed: %s\n",
+                    filename, parsed.uid, strerror(errno));
+            bad++;
+        }
+    }
+
+    if (parsed.has_gid) {
+        if (chown(filename, -1, parsed.gid) < 0) {
+            uiPrintf(state, "ApplyParsedPerms: chgrp of %s to %d failed: %s\n",
+                    filename, parsed.gid, strerror(errno));
+            bad++;
+        }
+    }
+
+    if (parsed.has_mode) {
+        if (chmod(filename, parsed.mode) < 0) {
+            uiPrintf(state, "ApplyParsedPerms: chmod of %s to %d failed: %s\n",
+                    filename, parsed.mode, strerror(errno));
+            bad++;
+        }
+    }
+
+    if (parsed.has_dmode && S_ISDIR(statptr->st_mode)) {
+        if (chmod(filename, parsed.dmode) < 0) {
+            uiPrintf(state, "ApplyParsedPerms: chmod of %s to %d failed: %s\n",
+                    filename, parsed.dmode, strerror(errno));
+            bad++;
+        }
+    }
+
+    if (parsed.has_fmode && S_ISREG(statptr->st_mode)) {
+        if (chmod(filename, parsed.fmode) < 0) {
+            uiPrintf(state, "ApplyParsedPerms: chmod of %s to %d failed: %s\n",
+                   filename, parsed.fmode, strerror(errno));
+            bad++;
+        }
+    }
+
+    if (parsed.has_capabilities && S_ISREG(statptr->st_mode)) {
+        if (parsed.capabilities == 0) {
+            if ((removexattr(filename, XATTR_NAME_CAPS) == -1) && (errno != ENODATA)) {
+                // Report failure unless it's ENODATA (attribute not set)
+                uiPrintf(state, "ApplyParsedPerms: removexattr of %s to %" PRIx64 " failed: %s\n",
+                       filename, parsed.capabilities, strerror(errno));
+                bad++;
+            }
+        } else {
+            struct vfs_cap_data cap_data;
+            memset(&cap_data, 0, sizeof(cap_data));
+            cap_data.magic_etc = VFS_CAP_REVISION | VFS_CAP_FLAGS_EFFECTIVE;
+            cap_data.data[0].permitted = (uint32_t) (parsed.capabilities & 0xffffffff);
+            cap_data.data[0].inheritable = 0;
+            cap_data.data[1].permitted = (uint32_t) (parsed.capabilities >> 32);
+            cap_data.data[1].inheritable = 0;
+            if (setxattr(filename, XATTR_NAME_CAPS, &cap_data, sizeof(cap_data), 0) < 0) {
+                uiPrintf(state, "ApplyParsedPerms: setcap of %s to %" PRIx64 " failed: %s\n",
+                        filename, parsed.capabilities, strerror(errno));
+                bad++;
+            }
+        }
+    }
+
+    return bad;
+}
+
+// nftw doesn't allow us to pass along context, so we need to use
+// global variables.  *sigh*
+static struct perm_parsed_args recursive_parsed_args;
+static State* recursive_state;
+
+static int do_SetMetadataRecursive(const char* filename, const struct stat *statptr,
+        int fileflags, struct FTW *pfwt) {
+    return ApplyParsedPerms(recursive_state, filename, statptr, recursive_parsed_args);
+}
+
+static Value* SetMetadataFn(const char* name, State* state, int argc, Expr* argv[]) {
+    int bad = 0;
+    struct stat sb;
+    Value* result = NULL;
+
+    bool recursive = (strcmp(name, "set_metadata_recursive") == 0);
+
+    if ((argc % 2) != 1) {
+        return ErrorAbort(state, "%s() expects an odd number of arguments, got %d", name, argc);
+    }
+
+    char** args = ReadVarArgs(state, argc, argv);
+    if (args == NULL) return NULL;
+
+    if (lstat(args[0], &sb) == -1) {
+        result = ErrorAbort(state, "%s: Error on lstat of \"%s\": %s", name, args[0], strerror(errno));
+        goto done;
+    }
+
+    {
+        struct perm_parsed_args parsed = ParsePermArgs(state, argc, args);
+
+        if (recursive) {
+            recursive_parsed_args = parsed;
+            recursive_state = state;
+            bad += nftw(args[0], do_SetMetadataRecursive, 30, FTW_CHDIR | FTW_DEPTH | FTW_PHYS);
+            memset(&recursive_parsed_args, 0, sizeof(recursive_parsed_args));
+            recursive_state = NULL;
+        } else {
+            bad += ApplyParsedPerms(state, args[0], &sb, parsed);
+        }
+    }
+
+done:
+    for (int i = 0; i < argc; ++i) {
+        free(args[i]);
+    }
+    free(args);
+
+    if (result != NULL) {
+        return result;
+    }
+
+    if (bad > 0) {
+        return ErrorAbort(state, "%s: some changes failed", name);
+    }
+
+    return StringValue(strdup(""));
+}
+
+Value* GetPropFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 1) {
+        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+    }
+    char* key = Evaluate(state, argv[0]);
+    if (key == NULL) return NULL;
+
+    char value[PROPERTY_VALUE_MAX];
+    property_get(key, value, "");
+    free(key);
+
+    return StringValue(strdup(value));
+}
+
+
+// file_getprop(file, key)
+//
+//   interprets 'file' as a getprop-style file (key=value pairs, one
+//   per line. # comment lines,blank lines, lines without '=' ignored),
+//   and returns the value for 'key' (or "" if it isn't defined).
+Value* FileGetPropFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char* result = NULL;
+    char* buffer = NULL;
+    char* filename;
+    char* key;
+    if (ReadArgs(state, argv, 2, &filename, &key) < 0) {
+        return NULL;
+    }
+
+    struct stat st;
+    if (stat(filename, &st) < 0) {
+        ErrorAbort(state, "%s: failed to stat \"%s\": %s", name, filename, strerror(errno));
+        goto done;
+    }
+
+#define MAX_FILE_GETPROP_SIZE    65536
+
+    if (st.st_size > MAX_FILE_GETPROP_SIZE) {
+        ErrorAbort(state, "%s too large for %s (max %d)", filename, name, MAX_FILE_GETPROP_SIZE);
+        goto done;
+    }
+
+    buffer = reinterpret_cast<char*>(malloc(st.st_size+1));
+    if (buffer == NULL) {
+        ErrorAbort(state, "%s: failed to alloc %lld bytes", name, (long long)st.st_size+1);
+        goto done;
+    }
+
+    FILE* f;
+    f = fopen(filename, "rb");
+    if (f == NULL) {
+        ErrorAbort(state, "%s: failed to open %s: %s", name, filename, strerror(errno));
+        goto done;
+    }
+
+    if (fread(buffer, 1, st.st_size, f) != st.st_size) {
+        ErrorAbort(state, "%s: failed to read %lld bytes from %s",
+                   name, (long long)st.st_size+1, filename);
+        fclose(f);
+        goto done;
+    }
+    buffer[st.st_size] = '\0';
+
+    fclose(f);
+
+    char* line;
+    line = strtok(buffer, "\n");
+    do {
+        // skip whitespace at start of line
+        while (*line && isspace(*line)) ++line;
+
+        // comment or blank line: skip to next line
+        if (*line == '\0' || *line == '#') continue;
+
+        char* equal = strchr(line, '=');
+        if (equal == NULL) {
+            continue;
+        }
+
+        // trim whitespace between key and '='
+        char* key_end = equal-1;
+        while (key_end > line && isspace(*key_end)) --key_end;
+        key_end[1] = '\0';
+
+        // not the key we're looking for
+        if (strcmp(key, line) != 0) continue;
+
+        // skip whitespace after the '=' to the start of the value
+        char* val_start = equal+1;
+        while(*val_start && isspace(*val_start)) ++val_start;
+
+        // trim trailing whitespace
+        char* val_end = val_start + strlen(val_start)-1;
+        while (val_end > val_start && isspace(*val_end)) --val_end;
+        val_end[1] = '\0';
+
+        result = strdup(val_start);
+        break;
+
+    } while ((line = strtok(NULL, "\n")));
+
+    if (result == NULL) result = strdup("");
+
+  done:
+    free(filename);
+    free(key);
+    free(buffer);
+    return StringValue(result);
+}
+
+// write_raw_image(filename_or_blob, partition)
+Value* WriteRawImageFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char* result = NULL;
+
+    Value* partition_value;
+    Value* contents;
+    if (ReadValueArgs(state, argv, 2, &contents, &partition_value) < 0) {
+        return NULL;
+    }
+
+    char* partition = NULL;
+    if (partition_value->type != VAL_STRING) {
+        ErrorAbort(state, "partition argument to %s must be string", name);
+        goto done;
+    }
+    partition = partition_value->data;
+    if (strlen(partition) == 0) {
+        ErrorAbort(state, "partition argument to %s can't be empty", name);
+        goto done;
+    }
+    if (contents->type == VAL_STRING && strlen((char*) contents->data) == 0) {
+        ErrorAbort(state, "file argument to %s can't be empty", name);
+        goto done;
+    }
+
+    mtd_scan_partitions();
+    const MtdPartition* mtd;
+    mtd = mtd_find_partition_by_name(partition);
+    if (mtd == NULL) {
+        printf("%s: no mtd partition named \"%s\"\n", name, partition);
+        result = strdup("");
+        goto done;
+    }
+
+    MtdWriteContext* ctx;
+    ctx = mtd_write_partition(mtd);
+    if (ctx == NULL) {
+        printf("%s: can't write mtd partition \"%s\"\n",
+                name, partition);
+        result = strdup("");
+        goto done;
+    }
+
+    bool success;
+
+    if (contents->type == VAL_STRING) {
+        // we're given a filename as the contents
+        char* filename = contents->data;
+        FILE* f = fopen(filename, "rb");
+        if (f == NULL) {
+            printf("%s: can't open %s: %s\n", name, filename, strerror(errno));
+            result = strdup("");
+            goto done;
+        }
+
+        success = true;
+        char* buffer = reinterpret_cast<char*>(malloc(BUFSIZ));
+        int read;
+        while (success && (read = fread(buffer, 1, BUFSIZ, f)) > 0) {
+            int wrote = mtd_write_data(ctx, buffer, read);
+            success = success && (wrote == read);
+        }
+        free(buffer);
+        fclose(f);
+    } else {
+        // we're given a blob as the contents
+        ssize_t wrote = mtd_write_data(ctx, contents->data, contents->size);
+        success = (wrote == contents->size);
+    }
+    if (!success) {
+        printf("mtd_write_data to %s failed: %s\n",
+                partition, strerror(errno));
+    }
+
+    if (mtd_erase_blocks(ctx, -1) == -1) {
+        printf("%s: error erasing blocks of %s\n", name, partition);
+    }
+    if (mtd_write_close(ctx) != 0) {
+        printf("%s: error closing write of %s\n", name, partition);
+    }
+
+    printf("%s %s partition\n",
+           success ? "wrote" : "failed to write", partition);
+
+    result = success ? partition : strdup("");
+
+done:
+    if (result != partition) FreeValue(partition_value);
+    FreeValue(contents);
+    return StringValue(result);
+}
+
+// apply_patch_space(bytes)
+Value* ApplyPatchSpaceFn(const char* name, State* state,
+                         int argc, Expr* argv[]) {
+    char* bytes_str;
+    if (ReadArgs(state, argv, 1, &bytes_str) < 0) {
+        return NULL;
+    }
+
+    char* endptr;
+    size_t bytes = strtol(bytes_str, &endptr, 10);
+    if (bytes == 0 && endptr == bytes_str) {
+        ErrorAbort(state, "%s(): can't parse \"%s\" as byte count\n\n", name, bytes_str);
+        free(bytes_str);
+        return NULL;
+    }
+
+    return StringValue(strdup(CacheSizeCheck(bytes) ? "" : "t"));
+}
+
+// apply_patch(file, size, init_sha1, tgt_sha1, patch)
+
+Value* ApplyPatchFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc < 6 || (argc % 2) == 1) {
+        return ErrorAbort(state, "%s(): expected at least 6 args and an "
+                                 "even number, got %d",
+                          name, argc);
+    }
+
+    char* source_filename;
+    char* target_filename;
+    char* target_sha1;
+    char* target_size_str;
+    if (ReadArgs(state, argv, 4, &source_filename, &target_filename,
+                 &target_sha1, &target_size_str) < 0) {
+        return NULL;
+    }
+
+    char* endptr;
+    size_t target_size = strtol(target_size_str, &endptr, 10);
+    if (target_size == 0 && endptr == target_size_str) {
+        ErrorAbort(state, "%s(): can't parse \"%s\" as byte count",
+                   name, target_size_str);
+        free(source_filename);
+        free(target_filename);
+        free(target_sha1);
+        free(target_size_str);
+        return NULL;
+    }
+
+    int patchcount = (argc-4) / 2;
+    Value** patches = ReadValueVarArgs(state, argc-4, argv+4);
+
+    int i;
+    for (i = 0; i < patchcount; ++i) {
+        if (patches[i*2]->type != VAL_STRING) {
+            ErrorAbort(state, "%s(): sha-1 #%d is not string", name, i);
+            break;
+        }
+        if (patches[i*2+1]->type != VAL_BLOB) {
+            ErrorAbort(state, "%s(): patch #%d is not blob", name, i);
+            break;
+        }
+    }
+    if (i != patchcount) {
+        for (i = 0; i < patchcount*2; ++i) {
+            FreeValue(patches[i]);
+        }
+        free(patches);
+        return NULL;
+    }
+
+    char** patch_sha_str = reinterpret_cast<char**>(malloc(patchcount * sizeof(char*)));
+    for (i = 0; i < patchcount; ++i) {
+        patch_sha_str[i] = patches[i*2]->data;
+        patches[i*2]->data = NULL;
+        FreeValue(patches[i*2]);
+        patches[i] = patches[i*2+1];
+    }
+
+    int result = applypatch(source_filename, target_filename,
+                            target_sha1, target_size,
+                            patchcount, patch_sha_str, patches, NULL);
+
+    for (i = 0; i < patchcount; ++i) {
+        FreeValue(patches[i]);
+    }
+    free(patch_sha_str);
+    free(patches);
+
+    return StringValue(strdup(result == 0 ? "t" : ""));
+}
+
+// apply_patch_check(file, [sha1_1, ...])
+Value* ApplyPatchCheckFn(const char* name, State* state,
+                         int argc, Expr* argv[]) {
+    if (argc < 1) {
+        return ErrorAbort(state, "%s(): expected at least 1 arg, got %d",
+                          name, argc);
+    }
+
+    char* filename;
+    if (ReadArgs(state, argv, 1, &filename) < 0) {
+        return NULL;
+    }
+
+    int patchcount = argc-1;
+    char** sha1s = ReadVarArgs(state, argc-1, argv+1);
+
+    int result = applypatch_check(filename, patchcount, sha1s);
+
+    int i;
+    for (i = 0; i < patchcount; ++i) {
+        free(sha1s[i]);
+    }
+    free(sha1s);
+
+    return StringValue(strdup(result == 0 ? "t" : ""));
+}
+
+Value* UIPrintFn(const char* name, State* state, int argc, Expr* argv[]) {
+    char** args = ReadVarArgs(state, argc, argv);
+    if (args == NULL) {
+        return NULL;
+    }
+
+    int size = 0;
+    int i;
+    for (i = 0; i < argc; ++i) {
+        size += strlen(args[i]);
+    }
+    char* buffer = reinterpret_cast<char*>(malloc(size+1));
+    size = 0;
+    for (i = 0; i < argc; ++i) {
+        strcpy(buffer+size, args[i]);
+        size += strlen(args[i]);
+        free(args[i]);
+    }
+    free(args);
+    buffer[size] = '\0';
+    uiPrint(state, buffer);
+    return StringValue(buffer);
+}
+
+Value* WipeCacheFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 0) {
+        return ErrorAbort(state, "%s() expects no args, got %d", name, argc);
+    }
+    fprintf(((UpdaterInfo*)(state->cookie))->cmd_pipe, "wipe_cache\n");
+    return StringValue(strdup("t"));
+}
+
+Value* RunProgramFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc < 1) {
+        return ErrorAbort(state, "%s() expects at least 1 arg", name);
+    }
+    char** args = ReadVarArgs(state, argc, argv);
+    if (args == NULL) {
+        return NULL;
+    }
+
+    char** args2 = reinterpret_cast<char**>(malloc(sizeof(char*) * (argc+1)));
+    memcpy(args2, args, sizeof(char*) * argc);
+    args2[argc] = NULL;
+
+    printf("about to run program [%s] with %d args\n", args2[0], argc);
+
+    pid_t child = fork();
+    if (child == 0) {
+        execv(args2[0], args2);
+        printf("run_program: execv failed: %s\n", strerror(errno));
+        _exit(1);
+    }
+    int status;
+    waitpid(child, &status, 0);
+    if (WIFEXITED(status)) {
+        if (WEXITSTATUS(status) != 0) {
+            printf("run_program: child exited with status %d\n",
+                    WEXITSTATUS(status));
+        }
+    } else if (WIFSIGNALED(status)) {
+        printf("run_program: child terminated by signal %d\n",
+                WTERMSIG(status));
+    }
+
+    int i;
+    for (i = 0; i < argc; ++i) {
+        free(args[i]);
+    }
+    free(args);
+    free(args2);
+
+    char buffer[20];
+    sprintf(buffer, "%d", status);
+
+    return StringValue(strdup(buffer));
+}
+
+// sha1_check(data)
+//    to return the sha1 of the data (given in the format returned by
+//    read_file).
+//
+// sha1_check(data, sha1_hex, [sha1_hex, ...])
+//    returns the sha1 of the file if it matches any of the hex
+//    strings passed, or "" if it does not equal any of them.
+//
+Value* Sha1CheckFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc < 1) {
+        return ErrorAbort(state, "%s() expects at least 1 arg", name);
+    }
+
+    Value** args = ReadValueVarArgs(state, argc, argv);
+    if (args == NULL) {
+        return NULL;
+    }
+
+    if (args[0]->size < 0) {
+        return StringValue(strdup(""));
+    }
+    uint8_t digest[SHA_DIGEST_SIZE];
+    SHA_hash(args[0]->data, args[0]->size, digest);
+    FreeValue(args[0]);
+
+    if (argc == 1) {
+        return StringValue(PrintSha1(digest));
+    }
+
+    int i;
+    uint8_t* arg_digest = reinterpret_cast<uint8_t*>(malloc(SHA_DIGEST_SIZE));
+    for (i = 1; i < argc; ++i) {
+        if (args[i]->type != VAL_STRING) {
+            printf("%s(): arg %d is not a string; skipping",
+                    name, i);
+        } else if (ParseSha1(args[i]->data, arg_digest) != 0) {
+            // Warn about bad args and skip them.
+            printf("%s(): error parsing \"%s\" as sha-1; skipping",
+                   name, args[i]->data);
+        } else if (memcmp(digest, arg_digest, SHA_DIGEST_SIZE) == 0) {
+            break;
+        }
+        FreeValue(args[i]);
+    }
+    if (i >= argc) {
+        // Didn't match any of the hex strings; return false.
+        return StringValue(strdup(""));
+    }
+    // Found a match; free all the remaining arguments and return the
+    // matched one.
+    int j;
+    for (j = i+1; j < argc; ++j) {
+        FreeValue(args[j]);
+    }
+    return args[i];
+}
+
+// Read a local file and return its contents (the Value* returned
+// is actually a FileContents*).
+Value* ReadFileFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 1) {
+        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+    }
+    char* filename;
+    if (ReadArgs(state, argv, 1, &filename) < 0) return NULL;
+
+    Value* v = reinterpret_cast<Value*>(malloc(sizeof(Value)));
+    v->type = VAL_BLOB;
+
+    FileContents fc;
+    if (LoadFileContents(filename, &fc) != 0) {
+        free(filename);
+        v->size = -1;
+        v->data = NULL;
+        free(fc.data);
+        return v;
+    }
+
+    v->size = fc.size;
+    v->data = (char*)fc.data;
+
+    free(filename);
+    return v;
+}
+
+// Immediately reboot the device.  Recovery is not finished normally,
+// so if you reboot into recovery it will re-start applying the
+// current package (because nothing has cleared the copy of the
+// arguments stored in the BCB).
+//
+// The argument is the partition name passed to the android reboot
+// property.  It can be "recovery" to boot from the recovery
+// partition, or "" (empty string) to boot from the regular boot
+// partition.
+Value* RebootNowFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+
+    char* filename;
+    char* property;
+    if (ReadArgs(state, argv, 2, &filename, &property) < 0) return NULL;
+
+    char buffer[80];
+
+    // zero out the 'command' field of the bootloader message.
+    memset(buffer, 0, sizeof(((struct bootloader_message*)0)->command));
+    FILE* f = fopen(filename, "r+b");
+    fseek(f, offsetof(struct bootloader_message, command), SEEK_SET);
+    fwrite(buffer, sizeof(((struct bootloader_message*)0)->command), 1, f);
+    fclose(f);
+    free(filename);
+
+    strcpy(buffer, "reboot,");
+    if (property != NULL) {
+        strncat(buffer, property, sizeof(buffer)-10);
+    }
+
+    property_set(ANDROID_RB_PROPERTY, buffer);
+
+    sleep(5);
+    free(property);
+    ErrorAbort(state, "%s() failed to reboot", name);
+    return NULL;
+}
+
+// Store a string value somewhere that future invocations of recovery
+// can access it.  This value is called the "stage" and can be used to
+// drive packages that need to do reboots in the middle of
+// installation and keep track of where they are in the multi-stage
+// install.
+//
+// The first argument is the block device for the misc partition
+// ("/misc" in the fstab), which is where this value is stored.  The
+// second argument is the string to store; it should not exceed 31
+// bytes.
+Value* SetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+
+    char* filename;
+    char* stagestr;
+    if (ReadArgs(state, argv, 2, &filename, &stagestr) < 0) return NULL;
+
+    // Store this value in the misc partition, immediately after the
+    // bootloader message that the main recovery uses to save its
+    // arguments in case of the device restarting midway through
+    // package installation.
+    FILE* f = fopen(filename, "r+b");
+    fseek(f, offsetof(struct bootloader_message, stage), SEEK_SET);
+    int to_write = strlen(stagestr)+1;
+    int max_size = sizeof(((struct bootloader_message*)0)->stage);
+    if (to_write > max_size) {
+        to_write = max_size;
+        stagestr[max_size-1] = 0;
+    }
+    fwrite(stagestr, to_write, 1, f);
+    fclose(f);
+
+    free(stagestr);
+    return StringValue(filename);
+}
+
+// Return the value most recently saved with SetStageFn.  The argument
+// is the block device for the misc partition.
+Value* GetStageFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 1) {
+        return ErrorAbort(state, "%s() expects 1 arg, got %d", name, argc);
+    }
+
+    char* filename;
+    if (ReadArgs(state, argv, 1, &filename) < 0) return NULL;
+
+    char buffer[sizeof(((struct bootloader_message*)0)->stage)];
+    FILE* f = fopen(filename, "rb");
+    fseek(f, offsetof(struct bootloader_message, stage), SEEK_SET);
+    fread(buffer, sizeof(buffer), 1, f);
+    fclose(f);
+    buffer[sizeof(buffer)-1] = '\0';
+
+    return StringValue(strdup(buffer));
+}
+
+Value* WipeBlockDeviceFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 2) {
+        return ErrorAbort(state, "%s() expects 2 args, got %d", name, argc);
+    }
+
+    char* filename;
+    char* len_str;
+    if (ReadArgs(state, argv, 2, &filename, &len_str) < 0) return NULL;
+
+    size_t len = strtoull(len_str, NULL, 0);
+    int fd = open(filename, O_WRONLY, 0644);
+    int success = wipe_block_device(fd, len);
+
+    free(filename);
+    free(len_str);
+
+    close(fd);
+
+    return StringValue(strdup(success ? "t" : ""));
+}
+
+Value* EnableRebootFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc != 0) {
+        return ErrorAbort(state, "%s() expects no args, got %d", name, argc);
+    }
+    UpdaterInfo* ui = (UpdaterInfo*)(state->cookie);
+    fprintf(ui->cmd_pipe, "enable_reboot\n");
+    return StringValue(strdup("t"));
+}
+
+Value* Tune2FsFn(const char* name, State* state, int argc, Expr* argv[]) {
+    if (argc == 0) {
+        return ErrorAbort(state, "%s() expects args, got %d", name, argc);
+    }
+
+    char** args = ReadVarArgs(state, argc, argv);
+    if (args == NULL) {
+        return ErrorAbort(state, "%s() could not read args", name);
+    }
+
+    char** args2 = reinterpret_cast<char**>(malloc(sizeof(char*) * (argc+1)));
+    // Tune2fs expects the program name as its args[0]
+    args2[0] = strdup(name);
+    for (int i = 0; i < argc; ++i) {
+       args2[i + 1] = args[i];
+    }
+    int result = tune2fs_main(argc + 1, args2);
+    for (int i = 0; i < argc; ++i) {
+        free(args[i]);
+    }
+    free(args);
+
+    free(args2[0]);
+    free(args2);
+    if (result != 0) {
+        return ErrorAbort(state, "%s() returned error code %d", name, result);
+    }
+    return StringValue(strdup("t"));
+}
+
+void RegisterInstallFunctions() {
+    RegisterFunction("mount", MountFn);
+    RegisterFunction("is_mounted", IsMountedFn);
+    RegisterFunction("unmount", UnmountFn);
+    RegisterFunction("format", FormatFn);
+    RegisterFunction("show_progress", ShowProgressFn);
+    RegisterFunction("set_progress", SetProgressFn);
+    RegisterFunction("delete", DeleteFn);
+    RegisterFunction("delete_recursive", DeleteFn);
+    RegisterFunction("package_extract_dir", PackageExtractDirFn);
+    RegisterFunction("package_extract_file", PackageExtractFileFn);
+    RegisterFunction("symlink", SymlinkFn);
+
+    // Usage:
+    //   set_metadata("filename", "key1", "value1", "key2", "value2", ...)
+    // Example:
+    //   set_metadata("/system/bin/netcfg", "uid", 0, "gid", 3003, "mode", 02750, "selabel", "u:object_r:system_file:s0", "capabilities", 0x0);
+    RegisterFunction("set_metadata", SetMetadataFn);
+
+    // Usage:
+    //   set_metadata_recursive("dirname", "key1", "value1", "key2", "value2", ...)
+    // Example:
+    //   set_metadata_recursive("/system", "uid", 0, "gid", 0, "fmode", 0644, "dmode", 0755, "selabel", "u:object_r:system_file:s0", "capabilities", 0x0);
+    RegisterFunction("set_metadata_recursive", SetMetadataFn);
+
+    RegisterFunction("getprop", GetPropFn);
+    RegisterFunction("file_getprop", FileGetPropFn);
+    RegisterFunction("write_raw_image", WriteRawImageFn);
+
+    RegisterFunction("apply_patch", ApplyPatchFn);
+    RegisterFunction("apply_patch_check", ApplyPatchCheckFn);
+    RegisterFunction("apply_patch_space", ApplyPatchSpaceFn);
+
+    RegisterFunction("wipe_block_device", WipeBlockDeviceFn);
+
+    RegisterFunction("read_file", ReadFileFn);
+    RegisterFunction("sha1_check", Sha1CheckFn);
+    RegisterFunction("rename", RenameFn);
+
+    RegisterFunction("wipe_cache", WipeCacheFn);
+
+    RegisterFunction("ui_print", UIPrintFn);
+
+    RegisterFunction("run_program", RunProgramFn);
+
+    RegisterFunction("reboot_now", RebootNowFn);
+    RegisterFunction("get_stage", GetStageFn);
+    RegisterFunction("set_stage", SetStageFn);
+
+    RegisterFunction("enable_reboot", EnableRebootFn);
+    RegisterFunction("tune2fs", Tune2FsFn);
+}