MXS-2900 Move testcore library files to a dedicated directory

The library is now named "maxtest". The related include-files are, for
now, usable without designating the full include path. This may be changed
later, but would require modifying every test.

maxscale-system-test/maxtest/src/get_my_ip.cpp

@@ -0,0 +1,60 @@
+/*
+ * Find local ip used as source ip in ip packets.
+ * Use getsockname and a udp connection
+ */
+
+#include <stdio.h>      // printf
+#include <string.h>     // memset
+#include <errno.h>      // errno
+#include <sys/socket.h> // socket
+#include <netinet/in.h> // sockaddr_in
+#include <arpa/inet.h>  // getsockname
+#include <unistd.h>     // close
+
+#include "get_my_ip.h"
+
+int get_my_ip(char* remote_ip, char* my_ip)
+{
+
+    int dns_port = 53;
+
+    struct sockaddr_in serv;
+
+    int sock = socket (AF_INET, SOCK_DGRAM, 0);
+
+    // Socket could not be created
+    if (sock < 0)
+    {
+        return 1;
+    }
+
+    memset(&serv, 0, sizeof(serv));
+    serv.sin_family = AF_INET;
+    serv.sin_addr.s_addr = inet_addr(remote_ip);
+    serv.sin_port = htons(dns_port);
+
+
+    connect(sock, (const struct sockaddr*) &serv, sizeof(serv));
+
+    struct sockaddr_in name;
+    socklen_t namelen = sizeof(name);
+    getsockname(sock, (struct sockaddr*) &name, &namelen);
+
+    char buffer[100];
+    const char* p = inet_ntop(AF_INET, &name.sin_addr, buffer, 100);
+
+    if (p != NULL)
+    {
+        // printf("Local ip is : %s \n" , buffer);
+        strcpy(my_ip, buffer);
+        close(sock);
+        return 0;
+    }
+    else
+    {
+        // Some error
+        printf ("Error number : %d . Error message : %s \n", errno, strerror(errno));
+        close(sock);
+        return 2;
+    }
+}