From: Mu-Woong Lee <muwoong.lee@samsung.com>
Date: Tue, 1 Aug 2017 11:44:54 +0000 (+0900)
Subject: Add defence code to handle socket read failure
X-Git-Tag: accepted/tizen/unified/20170904.144519^2~7
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=97a36ac553b22894aabc0c308b9e35cdb793011e;p=platform%2Fcore%2Fcontext%2Fcontext-service.git

Add defence code to handle socket read failure

Change-Id: Ic8e1f638d900c7d29804a93bcc1c09a80fde7f45
Signed-off-by: Mu-Woong Lee <muwoong.lee@samsung.com>
---

diff --git a/src/agent/AgentSocket.cpp b/src/agent/AgentSocket.cpp
index e8d45b9..f9d6fb5 100644
--- a/src/agent/AgentSocket.cpp
+++ b/src/agent/AgentSocket.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <errno.h>
 #include <fcntl.h>
 #include <sys/socket.h>
 #include <sys/un.h>
@@ -152,27 +153,43 @@ bool AgentSocket::__readCommand(int msgsock)
 {
 	uint16_t id = 0;
 	uint8_t length = 0;
-	int rval = 0;
-	char buf[CTX_AGENT_COMMAND_LIMIT] = {0};
-
-	rval = read(msgsock, &id, sizeof(id));
-	IF_FAIL_RETURN_TAG(rval == sizeof(id), false, _E, "read() failed");
+	char command[CTX_AGENT_COMMAND_LIMIT] = {0};
+
+	auto safeRead = [&msgsock](char* buf, size_t count)->bool {
+		do {
+			int rc = read(msgsock, buf, count);
+			if (rc < 0) {
+				if (errno == EAGAIN) {
+					continue;
+				} else {
+					_E("Socket read error: %d", errno);
+					return false;
+				}
+			}
+			count -= rc;
+			buf += rc;
+		} while (count > 0);
+		return true;
+	};
+
+	bool success;
+
+	success = safeRead(reinterpret_cast<char*>(&id), sizeof(id));
+	IF_FAIL_RETURN(success, false);
 
 	if (id == TERM_MSG_ID) {
 		_D("Stop listening...");
 		return false;
 	}
 
-	rval = read(msgsock, &length, sizeof(length));
-	IF_FAIL_RETURN_TAG(rval == sizeof(length), false, _E, "read() failed");
-
-	rval = read(msgsock, buf, length);
-	IF_FAIL_RETURN_TAG(rval == static_cast<int>(length), false, _E, "read() failed");
-
+	success = safeRead(reinterpret_cast<char*>(&length), sizeof(length));
+	IF_FAIL_RETURN(success, false);
+	IF_FAIL_RETURN_TAG(length > 0 && length <= CTX_AGENT_COMMAND_LIMIT, false, _E, "Invalid command");
 
-	buf[length] = '\0';
+	success = safeRead(command, length);
+	IF_FAIL_RETURN(success, false);
 
-	CommandInfo* info = new CommandInfo(&__pluginLoader, id, length, buf);
+	CommandInfo* info = new CommandInfo(&__pluginLoader, id, length, command);
 	g_idle_add(__send_command, info);
 
 	return true;