Support pre-KitKat properties for update-binary
Google changed the in-memory format for storing properties in 4.4.
Zips containing an older update-binary expect the old format, otherwise
assertions on properties in the update script fail.
This is just enough of the old property service to copy the properties
to the legacy format before running the updater.
Change-Id: I404680384bdc5e952609e295029ab0a0faf743a5
diff --git a/legacy_property_service.c b/legacy_property_service.c
new file mode 100644
index 0000000..0dc95ad
--- /dev/null
+++ b/legacy_property_service.c
@@ -0,0 +1,211 @@
+/*
+ * Copyright (C) 2007 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 <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <dirent.h>
+#include <limits.h>
+#include <errno.h>
+
+#include <cutils/properties.h>
+
+#include "legacy_properties.h"
+
+#include <sys/mman.h>
+#include <sys/atomics.h>
+#include "legacy_property_service.h"
+
+
+static int persistent_properties_loaded = 0;
+static int property_area_inited = 0;
+
+static int property_set_fd = -1;
+
+
+typedef struct {
+ void *data;
+ size_t size;
+ int fd;
+} workspace;
+
+static int init_workspace(workspace *w, size_t size)
+{
+ void *data;
+ int fd;
+
+ /* dev is a tmpfs that we can use to carve a shared workspace
+ * out of, so let's do that...
+ */
+ fd = open("/dev/__legacy_properties__", O_RDWR | O_CREAT, 0600);
+ if (fd < 0)
+ return -1;
+
+ if (ftruncate(fd, size) < 0)
+ goto out;
+
+ data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if(data == MAP_FAILED)
+ goto out;
+
+ close(fd);
+
+ fd = open("/dev/__legacy_properties__", O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ unlink("/dev/__legacy_properties__");
+
+ w->data = data;
+ w->size = size;
+ w->fd = fd;
+ return 0;
+
+out:
+ close(fd);
+ return -1;
+}
+
+/* (8 header words + 247 toc words) = 1020 bytes */
+/* 1024 bytes header and toc + 247 prop_infos @ 128 bytes = 32640 bytes */
+
+#define PA_COUNT_MAX 247
+#define PA_INFO_START 1024
+#define PA_SIZE 32768
+
+static workspace pa_workspace;
+static prop_info *pa_info_array;
+
+prop_area *__legacy_property_area__;
+
+static int init_property_area(void)
+{
+ prop_area *pa;
+
+ if(pa_info_array)
+ return -1;
+
+ if(init_workspace(&pa_workspace, PA_SIZE))
+ return -1;
+
+ fcntl(pa_workspace.fd, F_SETFD, FD_CLOEXEC);
+
+ pa_info_array = (void*) (((char*) pa_workspace.data) + PA_INFO_START);
+
+ pa = pa_workspace.data;
+ memset(pa, 0, PA_SIZE);
+ pa->magic = PROP_AREA_MAGIC;
+ pa->version = PROP_AREA_VERSION;
+
+ /* plug into the lib property services */
+ __legacy_property_area__ = pa;
+ property_area_inited = 1;
+ return 0;
+}
+
+static void update_prop_info(prop_info *pi, const char *value, unsigned len)
+{
+ pi->serial = pi->serial | 1;
+ memcpy(pi->value, value, len + 1);
+ pi->serial = (len << 24) | ((pi->serial + 1) & 0xffffff);
+ __futex_wake(&pi->serial, INT32_MAX);
+}
+
+static const prop_info *__legacy_property_find(const char *name)
+{
+ prop_area *pa = __legacy_property_area__;
+ unsigned count = pa->count;
+ unsigned *toc = pa->toc;
+ unsigned len = strlen(name);
+ prop_info *pi;
+
+ while(count--) {
+ unsigned entry = *toc++;
+ if(TOC_NAME_LEN(entry) != len) continue;
+
+ pi = TOC_TO_INFO(pa, entry);
+ if(memcmp(name, pi->name, len)) continue;
+
+ return pi;
+ }
+
+ return 0;
+}
+
+static int legacy_property_set(const char *name, const char *value)
+{
+ prop_area *pa;
+ prop_info *pi;
+
+ int namelen = strlen(name);
+ int valuelen = strlen(value);
+
+ if(namelen >= PROP_NAME_MAX) return -1;
+ if(valuelen >= PROP_VALUE_MAX) return -1;
+ if(namelen < 1) return -1;
+
+ pi = (prop_info*) __legacy_property_find(name);
+
+
+ if(pi != 0) {
+ /* ro.* properties may NEVER be modified once set */
+ if(!strncmp(name, "ro.", 3)) return -1;
+
+ pa = __legacy_property_area__;
+ update_prop_info(pi, value, valuelen);
+ pa->serial++;
+ __futex_wake(&pa->serial, INT32_MAX);
+ } else {
+ pa = __legacy_property_area__;
+ if(pa->count == PA_COUNT_MAX) return -1;
+
+ pi = pa_info_array + pa->count;
+ pi->serial = (valuelen << 24);
+ memcpy(pi->name, name, namelen + 1);
+ memcpy(pi->value, value, valuelen + 1);
+
+ pa->toc[pa->count] =
+ (namelen << 24) | (((unsigned) pi) - ((unsigned) pa));
+
+ pa->count++;
+ pa->serial++;
+ __futex_wake(&pa->serial, INT32_MAX);
+ }
+
+ return 0;
+}
+
+void legacy_get_property_workspace(int *fd, int *sz)
+{
+ *fd = pa_workspace.fd;
+ *sz = pa_workspace.size;
+}
+
+static void copy_property_to_legacy(const char *key, const char *value, void *cookie)
+{
+ legacy_property_set(key, value);
+}
+
+void legacy_properties_init()
+{
+ init_property_area();
+ property_list(copy_property_to_legacy, 0);
+}
+