The Annoyance Filter.pdf - Fourmilab

164 POP3 PROXY SERVER CLASS DEFINITION ANNOYANCE-FILTER §194
194. POP3 proxy server class definition.
We begin by defining the POP3Proxy class, which implements a general purpose POP3 proxy
capability.
#define POP_MAX_MESSAGE 512
#define POP_BUFFER ((POP_MAX_MESSAGE) + 2)
〈 Class definitions 10 〉 +≡
#ifdef POP3_PROXY_SERVER
〈 Declare signal handler function for broken pipes 216 〉
typedef void(∗POP3ProxyFilterFunction )(const string command , const string
argument , char ∗replyBuffer , int ∗replyLength , string &reply );
class POP3Proxy {
protected:
unsigned short popProxyPort ; /∗ Port on which POP proxy server listens ∗/
string serverName ; /∗ Domain name or IP address of POP server ∗/
unsigned short serverPort ; /∗ Port on which POP server listens ∗/
bool opened ; /∗ Have we established connection ? ∗/
private:
set〈string〉 multiLine , cMultiLine ; /∗ POP3 multi-line command lists ∗/
int listenSocket ; /∗ Socket on which we listen for connections ∗/
POP3ProxyFilterFunction filterFunction ; /∗ Filter function for replies from server ∗/
public:
POP3Proxy(unsigned short proxyPort = 9110, string serverN = "", unsigned short
serverP = 110, POP3ProxyFilterFunction filterF = Λ):
popProxyPort (proxyPort ), serverName (serverN ), serverPort (serverP ), opened (false ),
listenSocket (−1), filterFunction (filterF )
{
〈 Define multi-line and conditional multi-line commands 195 〉;
}
∼POP3Proxy( )
{
if (listenSocket ≠ −1) {
close (listenSocket );
signal (SIGPIPE, SIG_DFL);
}
}
void setPopProxyPort (unsigned short p)
{
〈 Check for POP3 connection already opened 196 〉;
popProxyPort = p;
}
void setServerName (string &s)
{
〈 Check for POP3 connection already opened 196 〉;
serverName = s;
}
void setServerPort (unsigned short p)
{
〈 Check for POP3 connection already opened 196 〉;
serverPort = p;
}