recovery: bu: Implement backup/restore

Change-Id: I9e684868ce15aaaed3a40338dadc20b003b50ade

1 files changed, 300 insertions, 0 deletions

diff --git a/backup.cpp b/backup.cpp
new file mode 100644
index 0000000..ad23b17
--- /dev/null
+++ b/backup.cpp
@@ -0,0 +1,300 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <sys/vfs.h>
+#include <time.h>
+
+#include "cutils/properties.h"
+
+#include "roots.h"
+
+#include "bu.h"
+
+#include "voldclient.h"
+
+using namespace android;
+
+static int append_sod(const char* opt_hash)
+{
+    const char* key;
+    char value[PROPERTY_VALUE_MAX];
+    int len;
+    char buf[PROP_LINE_LEN];
+    char sodbuf[PROP_LINE_LEN*10];
+    char* p = sodbuf;
+
+    key = "hash.name";
+    strcpy(value, opt_hash);
+    p += sprintf(p, "%s=%s\n", key, value);
+
+    key = "ro.product.device";
+    property_get(key, value, "");
+    p += sprintf(p, "%s=%s\n", key, value);
+
+    for (int i = 0; i < MAX_PART; ++i) {
+        partspec* part = part_get(i);
+        if (!part)
+            break;
+        if (!volume_is_mountable(part->vol) ||
+                volume_is_readonly(part->vol) ||
+                volume_is_verity(part->vol)) {
+            int fd = open(part->vol->blk_device, O_RDONLY);
+            part->size = part->used = lseek(fd, 0, SEEK_END);
+            close(fd);
+        }
+        else {
+            if (ensure_path_mounted(part->path) == 0) {
+                struct statfs stfs;
+                memset(&stfs, 0, sizeof(stfs));
+                if (statfs(part->path, &stfs) == 0) {
+                    part->size = (stfs.f_blocks) * stfs.f_bsize;
+                    part->used = (stfs.f_blocks - stfs.f_bfree) * stfs.f_bsize;
+                }
+                else {
+                    logmsg("Failed to statfs %s: %s\n", part->path, strerror(errno));
+                }
+                ensure_path_unmounted(part->path);
+            }
+            else {
+                int fd = open(part->vol->blk_device, O_RDONLY);
+                part->size = part->used = lseek(fd, 0, SEEK_END);
+                close(fd);
+            }
+        }
+        p += sprintf(p, "fs.%s.size=%llu\n", part->name, part->size);
+        p += sprintf(p, "fs.%s.used=%llu\n", part->name, part->used);
+    }
+
+    int rc = tar_append_file_contents(tar, "SOD", 0600,
+            getuid(), getgid(), sodbuf, p-sodbuf);
+    return rc;
+}
+
+static int append_eod(const char* opt_hash)
+{
+    char buf[PROP_LINE_LEN];
+    char eodbuf[PROP_LINE_LEN*10];
+    char* p = eodbuf;
+    int n;
+
+    p += sprintf(p, "hash.datalen=%u\n", hash_datalen);
+
+    unsigned char digest[HASH_MAX_LENGTH];
+    char hexdigest[HASH_MAX_STRING_LENGTH];
+
+    if (!strcasecmp(opt_hash, "sha1")) {
+        SHA1_Final(digest, &sha_ctx);
+        for (n = 0; n < SHA_DIGEST_LENGTH; ++n) {
+            sprintf(hexdigest+2*n, "%02x", digest[n]);
+        }
+        p += sprintf(p, "hash.value=%s\n", hexdigest);
+    }
+    else { // default to md5
+        MD5_Final(digest, &md5_ctx);
+        for (n = 0; n < MD5_DIGEST_LENGTH; ++n) {
+            sprintf(hexdigest+2*n, "%02x", digest[n]);
+        }
+        p += sprintf(p, "hash.value=%s\n", hexdigest);
+    }
+
+    int rc = tar_append_file_contents(tar, "EOD", 0600,
+            getuid(), getgid(), eodbuf, p-eodbuf);
+    return rc;
+}
+
+static int do_backup_tree(const String8& path)
+{
+    int rc = 0;
+    bool path_is_data = !strcmp(path.string(), "/data");
+    DIR *dp;
+
+    dp = opendir(path.string());
+    struct dirent *de;
+    while ((de = readdir(dp)) != NULL) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
+            continue;
+        }
+        if (path_is_data && !strcmp(de->d_name, "media") && vdc->isEmulatedStorage()) {
+            logmsg("do_backup_tree: skipping datamedia\n");
+            continue;
+        }
+        struct stat st;
+        String8 filepath(path);
+        filepath += "/";
+        filepath += de->d_name;
+
+        memset(&st, 0, sizeof(st));
+        rc = lstat(filepath.string(), &st);
+        if (rc != 0) {
+            logmsg("do_backup_tree: path=%s, lstat failed, rc=%d\n", path.string(), rc);
+            break;
+        }
+
+        if (!(S_ISREG(st.st_mode) || S_ISDIR(st.st_mode) || S_ISLNK(st.st_mode))) {
+            logmsg("do_backup_tree: path=%s, ignoring special file\n", path.string());
+            continue;
+        }
+
+        if (S_ISDIR(st.st_mode)) {
+            rc = tar_append_file(tar, filepath.string(), filepath.string());
+            if (rc != 0) {
+                logmsg("do_backup_tree: path=%s, tar_append_file failed, rc=%d\n", path.string(), rc);
+                break;
+            }
+            rc = do_backup_tree(filepath);
+            if (rc != 0) {
+                logmsg("do_backup_tree: path=%s, recursion failed, rc=%d\n", path.string(), rc);
+                break;
+            }
+        }
+        else {
+            rc = tar_append_file(tar, filepath.string(), filepath.string());
+            if (rc != 0) {
+                logmsg("do_backup_tree: path=%s, tar_append_file failed, rc=%d\n", path.string(), rc);
+                break;
+            }
+        }
+    }
+    closedir(dp);
+    return rc;
+}
+
+static int tar_append_device_contents(TAR* t, const char* devname, const char* savename)
+{
+    struct stat st;
+    memset(&st, 0, sizeof(st));
+    if (lstat(devname, &st) != 0) {
+        logmsg("tar_append_device_contents: lstat %s failed\n", devname);
+        return -1;
+    }
+    st.st_mode = 0644 | S_IFREG;
+
+    int fd = open(devname, O_RDONLY);
+    if (fd < 0) {
+        logmsg("tar_append_device_contents: open %s failed\n", devname);
+        return -1;
+    }
+    st.st_size = lseek(fd, 0, SEEK_END);
+    close(fd);
+
+    th_set_from_stat(t, &st);
+    th_set_path(t, savename);
+    if (th_write(t) != 0) {
+        logmsg("tar_append_device_contents: th_write failed\n");
+        return -1;
+    }
+    if (tar_append_regfile(t, devname) != 0) {
+        logmsg("tar_append_device_contents: tar_append_regfile %s failed\n", devname);
+        return -1;
+    }
+    return 0;
+}
+
+int do_backup(int argc, char **argv)
+{
+    int rc = 1;
+    int n;
+    int i;
+
+    int len;
+    int written;
+
+    const char* opt_compress = "gzip";
+    const char* opt_hash = "md5";
+
+    int optidx = 0;
+    while (optidx < argc && argv[optidx][0] == '-' && argv[optidx][1] == '-') {
+        char* optname = &argv[optidx][2];
+        ++optidx;
+        char* optval = strchr(optname, '=');
+        if (optval) {
+            *optval = '\0';
+            ++optval;
+        }
+        else {
+            if (optidx >= argc) {
+                logmsg("No argument to --%s\n", optname);
+                return -1;
+            }
+            optval = argv[optidx];
+            ++optidx;
+        }
+        if (!strcmp(optname, "compress")) {
+            opt_compress = optval;
+            logmsg("do_backup: compress=%s\n", opt_compress);
+        }
+        else if (!strcmp(optname, "hash")) {
+            opt_hash = optval;
+            logmsg("do_backup: hash=%s\n", opt_hash);
+        }
+        else {
+            logmsg("do_backup: invalid option name \"%s\"\n", optname);
+            return -1;
+        }
+    }
+    for (n = optidx; n < argc; ++n) {
+        const char* partname = argv[n];
+        if (*partname == '-')
+            ++partname;
+        if (part_add(partname) != 0) {
+            logmsg("Failed to add partition %s\n", partname);
+            return -1;
+        }
+    }
+
+    rc = create_tar(adb_ofd, opt_compress, "w");
+    if (rc != 0) {
+        logmsg("do_backup: cannot open tar stream\n");
+        return rc;
+    }
+
+    append_sod(opt_hash);
+
+    hash_name = strdup(opt_hash);
+
+    for (i = 0; i < MAX_PART; ++i) {
+        partspec* curpart = part_get(i);
+        if (!curpart)
+            break;
+
+        part_set(curpart);
+        if (!volume_is_mountable(curpart->vol) ||
+                volume_is_readonly(curpart->vol) ||
+                volume_is_verity(curpart->vol)) {
+            rc = tar_append_device_contents(tar, curpart->vol->blk_device, curpart->name);
+        }
+        else {
+            if (ensure_path_mounted(curpart->path) != 0) {
+                rc = tar_append_device_contents(tar, curpart->vol->blk_device, curpart->name);
+                if (rc != 0) {
+                    logmsg("do_backup: cannot backup %s\n", curpart->path);
+                    continue;
+                }
+            }
+            String8 path(curpart->path);
+            rc = do_backup_tree(path);
+            ensure_path_unmounted(curpart->path);
+        }
+    }
+
+    free(hash_name);
+    hash_name = NULL;
+
+    append_eod(opt_hash);
+
+    tar_append_eof(tar);
+
+    if (opt_compress)
+        gzflush(gzf, Z_FINISH);
+
+    logmsg("backup complete: rc=%d\n", rc);
+
+    return rc;
+}
+