Revert "Revert "New protocol for property_service""
This reverts commit 70c4ecf2b562ec643c270d65e0585fe8506d064c.
Bug: http://b/33926793
Bug: http://b/34670529
Test: run bionic-unit-tests --gtest_filter=prop*
Change-Id: I75b28146805ff37fbdcf0543ccb515ee5895eb2a
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 72fcb5b..b2f6411 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -27,6 +27,7 @@
#include <sys/poll.h>
#include <memory>
+#include <vector>
#include <cutils/misc.h>
#include <cutils/sockets.h>
@@ -48,6 +49,7 @@
#include <fs_mgr.h>
#include <android-base/file.h>
+#include <android-base/strings.h>
#include "bootimg.h"
#include "property_service.h"
@@ -70,30 +72,30 @@
}
}
-static int check_mac_perms(const char *name, char *sctx, struct ucred *cr)
-{
- char *tctx = NULL;
- int result = 0;
+static bool check_mac_perms(const std::string& name, char* sctx, struct ucred* cr) {
+
+ if (!sctx) {
+ return false;
+ }
+
+ if (!sehandle_prop) {
+ return false;
+ }
+
+ char* tctx = nullptr;
+ if (selabel_lookup(sehandle_prop, &tctx, name.c_str(), 1) != 0) {
+ return false;
+ }
+
property_audit_data audit_data;
- if (!sctx)
- goto err;
-
- if (!sehandle_prop)
- goto err;
-
- if (selabel_lookup(sehandle_prop, &tctx, name, 1) != 0)
- goto err;
-
- audit_data.name = name;
+ audit_data.name = name.c_str();
audit_data.cr = cr;
- if (selinux_check_access(sctx, tctx, "property_service", "set", reinterpret_cast<void*>(&audit_data)) == 0)
- result = 1;
+ bool has_access = (selinux_check_access(sctx, tctx, "property_service", "set", &audit_data) == 0);
freecon(tctx);
- err:
- return result;
+ return has_access;
}
static int check_control_mac_perms(const char *name, char *sctx, struct ucred *cr)
@@ -142,11 +144,9 @@
}
}
-bool is_legal_property_name(const std::string &name)
-{
+bool is_legal_property_name(const std::string& name) {
size_t namelen = name.size();
- if (namelen >= PROP_NAME_MAX) return false;
if (namelen < 1) return false;
if (name[0] == '.') return false;
if (name[namelen - 1] == '.') return false;
@@ -169,58 +169,217 @@
return true;
}
-int property_set(const char* name, const char* value) {
- size_t valuelen = strlen(value);
+uint32_t property_set(const std::string& name, const std::string& value) {
+ size_t valuelen = value.size();
if (!is_legal_property_name(name)) {
LOG(ERROR) << "property_set(\"" << name << "\", \"" << value << "\") failed: bad name";
- return -1;
+ return PROP_ERROR_INVALID_NAME;
}
+
if (valuelen >= PROP_VALUE_MAX) {
LOG(ERROR) << "property_set(\"" << name << "\", \"" << value << "\") failed: "
<< "value too long";
- return -1;
+ return PROP_ERROR_INVALID_VALUE;
}
- if (strcmp("selinux.restorecon_recursive", name) == 0 && valuelen > 0) {
- if (restorecon(value, SELINUX_ANDROID_RESTORECON_RECURSE) != 0) {
+ if (name == "selinux.restorecon_recursive" && valuelen > 0) {
+ if (restorecon(value.c_str(), SELINUX_ANDROID_RESTORECON_RECURSE) != 0) {
LOG(ERROR) << "Failed to restorecon_recursive " << value;
}
}
- prop_info* pi = (prop_info*) __system_property_find(name);
+ prop_info* pi = (prop_info*) __system_property_find(name.c_str());
if (pi != nullptr) {
// ro.* properties are actually "write-once".
- if (!strncmp(name, "ro.", 3)) {
+ if (android::base::StartsWith(name, "ro.")) {
LOG(ERROR) << "property_set(\"" << name << "\", \"" << value << "\") failed: "
<< "property already set";
- return -1;
+ return PROP_ERROR_READ_ONLY_PROPERTY;
}
- __system_property_update(pi, value, valuelen);
+ __system_property_update(pi, value.c_str(), valuelen);
} else {
- int rc = __system_property_add(name, strlen(name), value, valuelen);
+ int rc = __system_property_add(name.c_str(), name.size(), value.c_str(), valuelen);
if (rc < 0) {
LOG(ERROR) << "property_set(\"" << name << "\", \"" << value << "\") failed: "
<< "__system_property_add failed";
- return rc;
+ return PROP_ERROR_SET_FAILED;
}
}
// Don't write properties to disk until after we have read all default
// properties to prevent them from being overwritten by default values.
- if (persistent_properties_loaded && strncmp("persist.", name, strlen("persist.")) == 0) {
- write_persistent_property(name, value);
+ if (persistent_properties_loaded && android::base::StartsWith(name, "persist.")) {
+ write_persistent_property(name.c_str(), value.c_str());
}
- property_changed(name, value);
- return 0;
+ property_changed(name.c_str(), value.c_str());
+ return PROP_SUCCESS;
}
-static void handle_property_set_fd()
-{
- prop_msg msg;
- int r;
- char * source_ctx = NULL;
+class SocketConnection {
+ public:
+ SocketConnection(int socket, const struct ucred& cred)
+ : socket_(socket), cred_(cred) {}
+
+ ~SocketConnection() {
+ close(socket_);
+ }
+
+ bool RecvUint32(uint32_t* value, uint32_t* timeout_ms) {
+ return RecvFully(value, sizeof(*value), timeout_ms);
+ }
+
+ bool RecvChars(char* chars, size_t size, uint32_t* timeout_ms) {
+ return RecvFully(chars, size, timeout_ms);
+ }
+
+ bool RecvString(std::string* value, uint32_t* timeout_ms) {
+ uint32_t len = 0;
+ if (!RecvUint32(&len, timeout_ms)) {
+ return false;
+ }
+
+ if (len == 0) {
+ *value = "";
+ return true;
+ }
+
+ std::vector<char> chars(len);
+ if (!RecvChars(&chars[0], len, timeout_ms)) {
+ return false;
+ }
+
+ *value = std::string(&chars[0], len);
+ return true;
+ }
+
+ bool SendUint32(uint32_t value) {
+ int result = TEMP_FAILURE_RETRY(send(socket_, &value, sizeof(value), 0));
+ return result == sizeof(value);
+ }
+
+ int socket() {
+ return socket_;
+ }
+
+ const struct ucred& cred() {
+ return cred_;
+ }
+
+ private:
+ bool PollIn(uint32_t* timeout_ms) {
+ struct pollfd ufds[1];
+ ufds[0].fd = socket_;
+ ufds[0].events = POLLIN;
+ ufds[0].revents = 0;
+ while (*timeout_ms > 0) {
+ Timer timer;
+ int nr = poll(ufds, 1, *timeout_ms);
+ uint64_t millis = timer.duration_ns()/1000000;
+ *timeout_ms = (millis > *timeout_ms) ? 0 : *timeout_ms - millis;
+
+ if (nr > 0) {
+ return true;
+ }
+
+ if (nr == 0) {
+ // Timeout
+ break;
+ }
+
+ if (nr < 0 && errno != EINTR) {
+ PLOG(ERROR) << "sys_prop: error waiting for uid " << cred_.uid << " to send property message";
+ return false;
+ } else { // errno == EINTR
+ // Timer rounds milliseconds down in case of EINTR we want it to be rounded up
+ // to avoid slowing init down by causing EINTR with under millisecond timeout.
+ if (*timeout_ms > 0) {
+ --(*timeout_ms);
+ }
+ }
+ }
+
+ LOG(ERROR) << "sys_prop: timeout waiting for uid " << cred_.uid << " to send property message.";
+ return false;
+ }
+
+ bool RecvFully(void* data_ptr, size_t size, uint32_t* timeout_ms) {
+ size_t bytes_left = size;
+ char* data = static_cast<char*>(data_ptr);
+ while (*timeout_ms > 0 && bytes_left > 0) {
+ if (!PollIn(timeout_ms)) {
+ return false;
+ }
+
+ int result = TEMP_FAILURE_RETRY(recv(socket_, data, bytes_left, MSG_DONTWAIT));
+ if (result <= 0) {
+ return false;
+ }
+
+ bytes_left -= result;
+ data += result;
+ }
+
+ return bytes_left == 0;
+ }
+
+ int socket_;
+ struct ucred cred_;
+
+ DISALLOW_IMPLICIT_CONSTRUCTORS(SocketConnection);
+};
+
+static void handle_property_set(SocketConnection& socket,
+ const std::string& name,
+ const std::string& value,
+ bool legacy_protocol) {
+ const char* cmd_name = legacy_protocol ? "PROP_MSG_SETPROP" : "PROP_MSG_SETPROP2";
+ if (!is_legal_property_name(name)) {
+ LOG(ERROR) << "sys_prop(" << cmd_name << "): illegal property name \"" << name << "\"";
+ socket.SendUint32(PROP_ERROR_INVALID_NAME);
+ return;
+ }
+
+ struct ucred cr = socket.cred();
+ char* source_ctx = nullptr;
+ getpeercon(socket.socket(), &source_ctx);
+
+ if (android::base::StartsWith(name, "ctl.")) {
+ if (check_control_mac_perms(value.c_str(), source_ctx, &cr)) {
+ handle_control_message(name.c_str() + 4, value.c_str());
+ if (!legacy_protocol) {
+ socket.SendUint32(PROP_SUCCESS);
+ }
+ } else {
+ LOG(ERROR) << "sys_prop(" << cmd_name << "): Unable to " << (name.c_str() + 4)
+ << " service ctl [" << value << "]"
+ << " uid:" << cr.uid
+ << " gid:" << cr.gid
+ << " pid:" << cr.pid;
+ if (!legacy_protocol) {
+ socket.SendUint32(PROP_ERROR_HANDLE_CONTROL_MESSAGE);
+ }
+ }
+ } else {
+ if (check_mac_perms(name, source_ctx, &cr)) {
+ uint32_t result = property_set(name, value);
+ if (!legacy_protocol) {
+ socket.SendUint32(result);
+ }
+ } else {
+ LOG(ERROR) << "sys_prop(" << cmd_name << "): permission denied uid:" << cr.uid << " name:" << name;
+ if (!legacy_protocol) {
+ socket.SendUint32(PROP_ERROR_PERMISSION_DENIED);
+ }
+ }
+ }
+
+ freecon(source_ctx);
+}
+
+static void handle_property_set_fd() {
+ static constexpr uint32_t kDefaultSocketTimeout = 2000; /* ms */
int s = accept(property_set_fd, nullptr, nullptr);
if (s == -1) {
@@ -236,72 +395,50 @@
return;
}
- static constexpr int timeout_ms = 2 * 1000; /* Default 2 sec timeout for caller to send property. */
- struct pollfd ufds[1];
- ufds[0].fd = s;
- ufds[0].events = POLLIN;
- ufds[0].revents = 0;
- int nr = TEMP_FAILURE_RETRY(poll(ufds, 1, timeout_ms));
- if (nr == 0) {
- LOG(ERROR) << "sys_prop: timeout waiting for uid " << cr.uid << " to send property message.";
- close(s);
- return;
- } else if (nr < 0) {
- PLOG(ERROR) << "sys_prop: error waiting for uid " << cr.uid << " to send property message";
- close(s);
+ SocketConnection socket(s, cr);
+ uint32_t timeout_ms = kDefaultSocketTimeout;
+
+ uint32_t cmd = 0;
+
+ if (!socket.RecvUint32(&cmd, &timeout_ms)) {
+ PLOG(ERROR) << "sys_prop: error while reading command from the socket";
+ socket.SendUint32(PROP_ERROR_READ_CMD);
return;
}
- r = TEMP_FAILURE_RETRY(recv(s, &msg, sizeof(msg), MSG_DONTWAIT));
- if(r != sizeof(prop_msg)) {
- PLOG(ERROR) << "sys_prop: mis-match msg size received: " << r << " expected: " << sizeof(prop_msg);
- close(s);
- return;
- }
+ switch(cmd) {
+ case PROP_MSG_SETPROP: {
+ char prop_name[PROP_NAME_MAX];
+ char prop_value[PROP_VALUE_MAX];
- 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)) {
- LOG(ERROR) << "sys_prop: illegal property name \"" << msg.name << "\"";
- close(s);
- return;
+ if (!socket.RecvChars(prop_name, PROP_NAME_MAX, &timeout_ms) ||
+ !socket.RecvChars(prop_value, PROP_VALUE_MAX, &timeout_ms)) {
+ PLOG(ERROR) << "sys_prop(PROP_MSG_SETPROP): error while reading name/value from the socket";
+ return;
}
- getpeercon(s, &source_ctx);
+ prop_name[PROP_NAME_MAX-1] = 0;
+ prop_value[PROP_VALUE_MAX-1] = 0;
- 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, &cr)) {
- handle_control_message((char*) msg.name + 4, (char*) msg.value);
- } else {
- LOG(ERROR) << "sys_prop: Unable to " << (msg.name + 4)
- << " service ctl [" << msg.value << "]"
- << " uid:" << cr.uid
- << " gid:" << cr.gid
- << " pid:" << cr.pid;
- }
- } else {
- if (check_mac_perms(msg.name, source_ctx, &cr)) {
- property_set((char*) msg.name, (char*) msg.value);
- } else {
- LOG(ERROR) << "sys_prop: permission denied uid:" << cr.uid << " name:" << 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);
+ handle_property_set(socket, prop_value, prop_value, true);
break;
+ }
+ case PROP_MSG_SETPROP2: {
+ std::string name;
+ std::string value;
+ if (!socket.RecvString(&name, &timeout_ms) ||
+ !socket.RecvString(&value, &timeout_ms)) {
+ PLOG(ERROR) << "sys_prop(PROP_MSG_SETPROP2): error while reading name/value from the socket";
+ socket.SendUint32(PROP_ERROR_READ_DATA);
+ return;
+ }
+
+ handle_property_set(socket, name, value, false);
+ break;
+ }
default:
- close(s);
+ socket.SendUint32(PROP_ERROR_INVALID_CMD);
break;
}
}
@@ -510,6 +647,8 @@
}
void start_property_service() {
+ property_set("ro.property_service.version", "2");
+
property_set_fd = create_socket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
0666, 0, 0, NULL);
if (property_set_fd == -1) {
diff --git a/init/property_service.h b/init/property_service.h
index e3a2acb..5d59473 100644
--- a/init/property_service.h
+++ b/init/property_service.h
@@ -27,14 +27,14 @@
const char* name;
};
-extern void property_init(void);
-extern void property_load_boot_defaults(void);
-extern void load_persist_props(void);
-extern void load_system_props(void);
-extern void start_property_service(void);
+void property_init(void);
+void property_load_boot_defaults(void);
+void load_persist_props(void);
+void load_system_props(void);
+void start_property_service(void);
std::string property_get(const char* name);
-extern int property_set(const char *name, const char *value);
-extern bool is_legal_property_name(const std::string &name);
+uint32_t property_set(const std::string& name, const std::string& value);
+bool is_legal_property_name(const std::string& name);
#endif /* _INIT_PROPERTY_H */