Build init as C++.

This is just the minimal change to keep it building.

Change-Id: I245c5b8413a1db114576c81462eb5737f5ffcef2
diff --git a/init/property_service.cpp b/init/property_service.cpp
new file mode 100644
index 0000000..4f0a46c
--- /dev/null
+++ b/init/property_service.cpp
@@ -0,0 +1,560 @@
+/*
+ * 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 <sys/poll.h>
+
+#include <cutils/misc.h>
+#include <cutils/sockets.h>
+#include <cutils/multiuser.h>
+
+#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
+#include <sys/_system_properties.h>
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/select.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <sys/mman.h>
+#include <private/android_filesystem_config.h>
+
+#include <selinux/selinux.h>
+#include <selinux/label.h>
+
+#include "property_service.h"
+#include "init.h"
+#include "util.h"
+#include "log.h"
+
+#define PERSISTENT_PROPERTY_DIR  "/data/property"
+
+static int persistent_properties_loaded = 0;
+static int property_area_inited = 0;
+
+static int property_set_fd = -1;
+
+typedef struct {
+    size_t size;
+    int fd;
+} workspace;
+
+static int init_workspace(workspace *w, size_t size)
+{
+    int fd = open(PROP_FILENAME, O_RDONLY | O_NOFOLLOW);
+    if (fd < 0)
+        return -1;
+
+    w->size = size;
+    w->fd = fd;
+    return 0;
+}
+
+static workspace pa_workspace;
+
+static int init_property_area(void)
+{
+    if (property_area_inited)
+        return -1;
+
+    if(__system_property_area_init())
+        return -1;
+
+    if(init_workspace(&pa_workspace, 0))
+        return -1;
+
+    fcntl(pa_workspace.fd, F_SETFD, FD_CLOEXEC);
+
+    property_area_inited = 1;
+    return 0;
+}
+
+static int check_mac_perms(const char *name, char *sctx)
+{
+    if (is_selinux_enabled() <= 0)
+        return 1;
+
+    char *tctx = NULL;
+    int result = 0;
+
+    if (!sctx)
+        goto err;
+
+    if (!sehandle_prop)
+        goto err;
+
+    if (selabel_lookup(sehandle_prop, &tctx, name, 1) != 0)
+        goto err;
+
+    if (selinux_check_access(sctx, tctx, "property_service", "set", (void*) name) == 0)
+        result = 1;
+
+    freecon(tctx);
+ err:
+    return result;
+}
+
+static int check_control_mac_perms(const char *name, char *sctx)
+{
+    /*
+     *  Create a name prefix out of ctl.<service name>
+     *  The new prefix allows the use of the existing
+     *  property service backend labeling while avoiding
+     *  mislabels based on true property prefixes.
+     */
+    char ctl_name[PROP_VALUE_MAX+4];
+    int ret = snprintf(ctl_name, sizeof(ctl_name), "ctl.%s", name);
+
+    if (ret < 0 || (size_t) ret >= sizeof(ctl_name))
+        return 0;
+
+    return check_mac_perms(ctl_name, sctx);
+}
+
+/*
+ * Checks permissions for setting system properties.
+ * Returns 1 if uid allowed, 0 otherwise.
+ */
+static int check_perms(const char *name, char *sctx)
+{
+    if(!strncmp(name, "ro.", 3))
+        name +=3;
+
+    return check_mac_perms(name, sctx);
+}
+
+int __property_get(const char *name, char *value)
+{
+    return __system_property_get(name, value);
+}
+
+static void write_persistent_property(const char *name, const char *value)
+{
+    char tempPath[PATH_MAX];
+    char path[PATH_MAX];
+    int fd;
+
+    snprintf(tempPath, sizeof(tempPath), "%s/.temp.XXXXXX", PERSISTENT_PROPERTY_DIR);
+    fd = mkstemp(tempPath);
+    if (fd < 0) {
+        ERROR("Unable to write persistent property to temp file %s errno: %d\n", tempPath, errno);
+        return;
+    }
+    write(fd, value, strlen(value));
+    fsync(fd);
+    close(fd);
+
+    snprintf(path, sizeof(path), "%s/%s", PERSISTENT_PROPERTY_DIR, name);
+    if (rename(tempPath, path)) {
+        unlink(tempPath);
+        ERROR("Unable to rename persistent property file %s to %s\n", tempPath, path);
+    }
+}
+
+static bool is_legal_property_name(const char* name, size_t namelen)
+{
+    size_t i;
+    if (namelen >= PROP_NAME_MAX) return false;
+    if (namelen < 1) return false;
+    if (name[0] == '.') return false;
+    if (name[namelen - 1] == '.') return false;
+
+    /* Only allow alphanumeric, plus '.', '-', or '_' */
+    /* Don't allow ".." to appear in a property name */
+    for (i = 0; i < namelen; i++) {
+        if (name[i] == '.') {
+            // i=0 is guaranteed to never have a dot. See above.
+            if (name[i-1] == '.') return false;
+            continue;
+        }
+        if (name[i] == '_' || name[i] == '-') continue;
+        if (name[i] >= 'a' && name[i] <= 'z') continue;
+        if (name[i] >= 'A' && name[i] <= 'Z') continue;
+        if (name[i] >= '0' && name[i] <= '9') continue;
+        return false;
+    }
+
+    return true;
+}
+
+int property_set(const char *name, const char *value)
+{
+    prop_info *pi;
+    int ret;
+
+    size_t namelen = strlen(name);
+    size_t valuelen = strlen(value);
+
+    if (!is_legal_property_name(name, namelen)) return -1;
+    if (valuelen >= PROP_VALUE_MAX) return -1;
+
+    pi = (prop_info*) __system_property_find(name);
+
+    if(pi != 0) {
+        /* ro.* properties may NEVER be modified once set */
+        if(!strncmp(name, "ro.", 3)) return -1;
+
+        __system_property_update(pi, value, valuelen);
+    } else {
+        ret = __system_property_add(name, namelen, value, valuelen);
+        if (ret < 0) {
+            ERROR("Failed to set '%s'='%s'\n", name, value);
+            return ret;
+        }
+    }
+    /* If name starts with "net." treat as a DNS property. */
+    if (strncmp("net.", name, strlen("net.")) == 0)  {
+        if (strcmp("net.change", name) == 0) {
+            return 0;
+        }
+       /*
+        * The 'net.change' property is a special property used track when any
+        * 'net.*' property name is updated. It is _ONLY_ updated here. Its value
+        * contains the last updated 'net.*' property.
+        */
+        property_set("net.change", name);
+    } else if (persistent_properties_loaded &&
+            strncmp("persist.", name, strlen("persist.")) == 0) {
+        /*
+         * Don't write properties to disk until after we have read all default properties
+         * to prevent them from being overwritten by default values.
+         */
+        write_persistent_property(name, value);
+    } else if (strcmp("selinux.reload_policy", name) == 0 &&
+               strcmp("1", value) == 0) {
+        selinux_reload_policy();
+    }
+    property_changed(name, value);
+    return 0;
+}
+
+void handle_property_set_fd()
+{
+    prop_msg msg;
+    int s;
+    int r;
+    struct ucred cr;
+    struct sockaddr_un addr;
+    socklen_t addr_size = sizeof(addr);
+    socklen_t cr_size = sizeof(cr);
+    char * source_ctx = NULL;
+    struct pollfd ufds[1];
+    const int timeout_ms = 2 * 1000;  /* Default 2 sec timeout for caller to send property. */
+    int nr;
+
+    if ((s = accept(property_set_fd, (struct sockaddr *) &addr, &addr_size)) < 0) {
+        return;
+    }
+
+    /* Check socket options here */
+    if (getsockopt(s, SOL_SOCKET, SO_PEERCRED, &cr, &cr_size) < 0) {
+        close(s);
+        ERROR("Unable to receive socket options\n");
+        return;
+    }
+
+    ufds[0].fd = s;
+    ufds[0].events = POLLIN;
+    ufds[0].revents = 0;
+    nr = TEMP_FAILURE_RETRY(poll(ufds, 1, timeout_ms));
+    if (nr == 0) {
+        ERROR("sys_prop: timeout waiting for uid=%d to send property message.\n", cr.uid);
+        close(s);
+        return;
+    } else if (nr < 0) {
+        ERROR("sys_prop: error waiting for uid=%d to send property message. err=%d %s\n", cr.uid, errno, strerror(errno));
+        close(s);
+        return;
+    }
+
+    r = TEMP_FAILURE_RETRY(recv(s, &msg, sizeof(msg), MSG_DONTWAIT));
+    if(r != sizeof(prop_msg)) {
+        ERROR("sys_prop: mis-match msg size received: %d expected: %zu errno: %d\n",
+              r, sizeof(prop_msg), errno);
+        close(s);
+        return;
+    }
+
+    switch(msg.cmd) {
+    case PROP_MSG_SETPROP:
+        msg.name[PROP_NAME_MAX-1] = 0;
+        msg.value[PROP_VALUE_MAX-1] = 0;
+
+        if (!is_legal_property_name(msg.name, strlen(msg.name))) {
+            ERROR("sys_prop: illegal property name. Got: \"%s\"\n", msg.name);
+            close(s);
+            return;
+        }
+
+        getpeercon(s, &source_ctx);
+
+        if(memcmp(msg.name,"ctl.",4) == 0) {
+            // Keep the old close-socket-early behavior when handling
+            // ctl.* properties.
+            close(s);
+            if (check_control_mac_perms(msg.value, source_ctx)) {
+                handle_control_message((char*) msg.name + 4, (char*) msg.value);
+            } else {
+                ERROR("sys_prop: Unable to %s service ctl [%s] uid:%d gid:%d pid:%d\n",
+                        msg.name + 4, msg.value, cr.uid, cr.gid, cr.pid);
+            }
+        } else {
+            if (check_perms(msg.name, source_ctx)) {
+                property_set((char*) msg.name, (char*) msg.value);
+            } else {
+                ERROR("sys_prop: permission denied uid:%d  name:%s\n",
+                      cr.uid, msg.name);
+            }
+
+            // Note: bionic's property client code assumes that the
+            // property server will not close the socket until *AFTER*
+            // the property is written to memory.
+            close(s);
+        }
+        freecon(source_ctx);
+        break;
+
+    default:
+        close(s);
+        break;
+    }
+}
+
+void get_property_workspace(int *fd, int *sz)
+{
+    *fd = pa_workspace.fd;
+    *sz = pa_workspace.size;
+}
+
+static void load_properties_from_file(const char *, const char *);
+
+/*
+ * Filter is used to decide which properties to load: NULL loads all keys,
+ * "ro.foo.*" is a prefix match, and "ro.foo.bar" is an exact match.
+ */
+static void load_properties(char *data, const char *filter)
+{
+    char *key, *value, *eol, *sol, *tmp, *fn;
+    size_t flen = 0;
+
+    if (filter) {
+        flen = strlen(filter);
+    }
+
+    sol = data;
+    while ((eol = strchr(sol, '\n'))) {
+        key = sol;
+        *eol++ = 0;
+        sol = eol;
+
+        while (isspace(*key)) key++;
+        if (*key == '#') continue;
+
+        tmp = eol - 2;
+        while ((tmp > key) && isspace(*tmp)) *tmp-- = 0;
+
+        if (!strncmp(key, "import ", 7) && flen == 0) {
+            fn = key + 7;
+            while (isspace(*fn)) fn++;
+
+            key = strchr(fn, ' ');
+            if (key) {
+                *key++ = 0;
+                while (isspace(*key)) key++;
+            }
+
+            load_properties_from_file(fn, key);
+
+        } else {
+            value = strchr(key, '=');
+            if (!value) continue;
+            *value++ = 0;
+
+            tmp = value - 2;
+            while ((tmp > key) && isspace(*tmp)) *tmp-- = 0;
+
+            while (isspace(*value)) value++;
+
+            if (flen > 0) {
+                if (filter[flen - 1] == '*') {
+                    if (strncmp(key, filter, flen - 1)) continue;
+                } else {
+                    if (strcmp(key, filter)) continue;
+                }
+            }
+
+            property_set(key, value);
+        }
+    }
+}
+
+/*
+ * Filter is used to decide which properties to load: NULL loads all keys,
+ * "ro.foo.*" is a prefix match, and "ro.foo.bar" is an exact match.
+ */
+static void load_properties_from_file(const char *fn, const char *filter)
+{
+    char *data;
+    unsigned sz;
+
+    data = read_file(fn, &sz);
+
+    if(data != 0) {
+        load_properties(data, filter);
+        free(data);
+    }
+}
+
+static void load_persistent_properties()
+{
+    DIR* dir = opendir(PERSISTENT_PROPERTY_DIR);
+    int dir_fd;
+    struct dirent*  entry;
+    char value[PROP_VALUE_MAX];
+    int fd, length;
+    struct stat sb;
+
+    if (dir) {
+        dir_fd = dirfd(dir);
+        while ((entry = readdir(dir)) != NULL) {
+            if (strncmp("persist.", entry->d_name, strlen("persist.")))
+                continue;
+            if (entry->d_type != DT_REG)
+                continue;
+            /* open the file and read the property value */
+            fd = openat(dir_fd, entry->d_name, O_RDONLY | O_NOFOLLOW);
+            if (fd < 0) {
+                ERROR("Unable to open persistent property file \"%s\" errno: %d\n",
+                      entry->d_name, errno);
+                continue;
+            }
+            if (fstat(fd, &sb) < 0) {
+                ERROR("fstat on property file \"%s\" failed errno: %d\n", entry->d_name, errno);
+                close(fd);
+                continue;
+            }
+
+            // File must not be accessible to others, be owned by root/root, and
+            // not be a hard link to any other file.
+            if (((sb.st_mode & (S_IRWXG | S_IRWXO)) != 0)
+                    || (sb.st_uid != 0)
+                    || (sb.st_gid != 0)
+                    || (sb.st_nlink != 1)) {
+                ERROR("skipping insecure property file %s (uid=%u gid=%u nlink=%u mode=%o)\n",
+                      entry->d_name, (unsigned int)sb.st_uid, (unsigned int)sb.st_gid,
+                      (unsigned int)sb.st_nlink, sb.st_mode);
+                close(fd);
+                continue;
+            }
+
+            length = read(fd, value, sizeof(value) - 1);
+            if (length >= 0) {
+                value[length] = 0;
+                property_set(entry->d_name, value);
+            } else {
+                ERROR("Unable to read persistent property file %s errno: %d\n",
+                      entry->d_name, errno);
+            }
+            close(fd);
+        }
+        closedir(dir);
+    } else {
+        ERROR("Unable to open persistent property directory %s errno: %d\n", PERSISTENT_PROPERTY_DIR, errno);
+    }
+
+    persistent_properties_loaded = 1;
+}
+
+void property_init(void)
+{
+    init_property_area();
+}
+
+void property_load_boot_defaults(void)
+{
+    load_properties_from_file(PROP_PATH_RAMDISK_DEFAULT, NULL);
+}
+
+int properties_inited(void)
+{
+    return property_area_inited;
+}
+
+static void load_override_properties() {
+#ifdef ALLOW_LOCAL_PROP_OVERRIDE
+    char debuggable[PROP_VALUE_MAX];
+    int ret;
+
+    ret = property_get("ro.debuggable", debuggable);
+    if (ret && (strcmp(debuggable, "1") == 0)) {
+        load_properties_from_file(PROP_PATH_LOCAL_OVERRIDE, NULL);
+    }
+#endif /* ALLOW_LOCAL_PROP_OVERRIDE */
+}
+
+
+/* When booting an encrypted system, /data is not mounted when the
+ * property service is started, so any properties stored there are
+ * not loaded.  Vold triggers init to load these properties once it
+ * has mounted /data.
+ */
+void load_persist_props(void)
+{
+    load_override_properties();
+    /* Read persistent properties after all default values have been loaded. */
+    load_persistent_properties();
+}
+
+void load_all_props(void)
+{
+    load_properties_from_file(PROP_PATH_SYSTEM_BUILD, NULL);
+    load_properties_from_file(PROP_PATH_SYSTEM_DEFAULT, NULL);
+    load_properties_from_file(PROP_PATH_VENDOR_BUILD, NULL);
+    load_properties_from_file(PROP_PATH_BOOTIMAGE_BUILD, NULL);
+    load_properties_from_file(PROP_PATH_FACTORY, "ro.*");
+
+    load_override_properties();
+
+    /* Read persistent properties after all default values have been loaded. */
+    load_persistent_properties();
+}
+
+void start_property_service(void)
+{
+    int fd;
+
+    fd = create_socket(PROP_SERVICE_NAME, SOCK_STREAM, 0666, 0, 0, NULL);
+    if(fd < 0) return;
+    fcntl(fd, F_SETFD, FD_CLOEXEC);
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+
+    listen(fd, 8);
+    property_set_fd = fd;
+}
+
+int get_property_set_fd()
+{
+    return property_set_fd;
+}