X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fio%2Fsg_socket_udp.cxx;h=6e43eb96098381dc6b6b4c52c6f7991c4d8369b0;hb=598b64fa9569c16878c904e344e2e2775e210c42;hp=97f0d8e00875cc1d5b60fca12d32596b1935758a;hpb=dcb95d131bc6aef1abe25d1f415e309f06e52436;p=simgear.git

diff --git a/simgear/io/sg_socket_udp.cxx b/simgear/io/sg_socket_udp.cxx
index 97f0d8e0..6e43eb96 100644
--- a/simgear/io/sg_socket_udp.cxx
+++ b/simgear/io/sg_socket_udp.cxx
@@ -26,14 +26,15 @@
 
 #include <simgear/compiler.h>
 
-#if defined( sgi )
-#include <strings.h>
-#endif
-
 #include <simgear/debug/logstream.hxx>
 
 #include "sg_socket_udp.hxx"
 
+#include <cstring>
+#include <cstdlib> // for atoi
+#include <algorithm>
+
+using std::string;
 
 SGSocketUDP::SGSocketUDP( const string& host, const string& port ) :
     hostname(host),
@@ -103,9 +104,14 @@ int SGSocketUDP::read( char *buf, int length ) {
 	return 0;
     }
 
+    if (length <= 0) {
+        return 0;
+    }
     int result;
+    // prevent buffer overflow
+    int maxsize = std::min(length - 1, SG_IO_MAX_MSG_SIZE);
 
-    if ( (result = sock.recv(buf, SG_IO_MAX_MSG_SIZE, 0)) >= 0 ) {
+    if ( (result = sock.recv(buf, maxsize, 0)) >= 0 ) {
 	buf[result] = '\0';
 	// printf("msg received = %s\n", buf);
     }
@@ -120,10 +126,16 @@ int SGSocketUDP::readline( char *buf, int length ) {
 	return 0;
     }
 
+    if (length <= 0) {
+        return 0;
+    }
     // cout << "sock = " << sock << endl;
 
     char *buf_ptr = save_buf + save_len;
-    int result = sock.recv(buf_ptr, SG_IO_MAX_MSG_SIZE, 0);
+    // prevent buffer overflow (size of save_buf is 2 * SG_IO_MAX_MSG_SIZE)
+    int maxsize = save_len < SG_IO_MAX_MSG_SIZE ?
+    SG_IO_MAX_MSG_SIZE : 2 * SG_IO_MAX_MSG_SIZE - save_len;
+    int result = sock.recv(buf_ptr, maxsize, 0);
     // printf("msg received = %s\n", buf);
     save_len += result;
 
@@ -142,6 +154,8 @@ int SGSocketUDP::readline( char *buf, int length ) {
     // we found an end of line
 
     // copy to external buffer
+    // prevent buffer overflow
+    result = std::min(result,length - 1);
     strncpy( buf, save_buf, result );
     buf[result] = '\0';
     // cout << "sg_socket line = " << buf << endl;
@@ -162,11 +176,8 @@ int SGSocketUDP::write( const char *buf, const int length ) {
 	return 0;
     }
 
-    bool error_condition = false;
-
     if ( sock.send( buf, length, 0 ) < 0 ) {
 	SG_LOG( SG_IO, SG_WARN, "Error writing to socket: " << port );
-	error_condition = true;
 	return 0;
     }