Author: dbkr
Date: 2008-04-30 22:28:37 +0000 (Wed, 30 Apr 2008)
New Revision: 19639
Modified:
trunk/apps/Freemail/src/freemail/OutboundContact.java
Log:
Don't re-insert mail to different slots - re-send the RTS instead. This will
allow contacts to be re-established if the inbound contact has been deleted.
Modified: trunk/apps/Freemail/src/freemail/OutboundContact.java
===================================================================
--- trunk/apps/Freemail/src/freemail/OutboundContact.java 2008-04-30
21:55:00 UTC (rev 19638)
+++ trunk/apps/Freemail/src/freemail/OutboundContact.java 2008-04-30
22:28:37 UTC (rev 19639)
@@ -73,10 +73,9 @@
private static final long CTS_WAIT_TIME = 26 * 60 * 60 * 1000;
private static final String PROPSFILE_NAME = "props";
- // how long do we wait before retransmitting the message? 26 hours
allows
- // for people starting Freemail at roughly the same time every day
- private static final long RETRANSMIT_DELAY = 26 * 60 * 60 * 1000;
+ // How long to wait for a *message ack* before sending another RTS.
+ private static final long RTS_RETRANSMIT_DELAY = 2 * 24 * 60 * 60 *
1000;
// how long do we wait before we give up all hope and just bounce the
message back?
// 5 days is fairly standard, so we'll go with that for now, except
that means things
@@ -91,6 +90,10 @@
// we read 128 bytes for our IV, so it needs to be constant.)
private static final int AES_BLOCK_LENGTH = 128 / 8;
+ // If we last fetched the mailsite longer than this number of
milliseconds
+ // ago, re-fetch it.
+ private static final long MAILSITE_CACHE_TIME = 60 * 60 * 1000;
+
public OutboundContact(FreemailAccount acc, EmailAddress a) throws
BadFreemailAddressException, IOException,
OutboundContactFatalException, ConnectionTerminatedException {
this.address = a;
@@ -274,20 +277,39 @@
return rtsksk;
}
- private String getInitialSlot() {
- String retval = this.contactfile.get("initialslot");
-
- if (retval != null) return retval;
-
- SecureRandom rnd = new SecureRandom();
- SHA256Digest sha256 = new SHA256Digest();
- byte[] buf = new byte[sha256.getDigestSize()];
-
- rnd.nextBytes(buf);
-
- this.contactfile.put("initialslot", Base32.encode(buf));
-
- return Base32.encode(buf);
+ /**
+ * Get the first slot from which all messages that are still 'in
transit' can be retrieved.
+ * That is to say, if we have message IDs 3,4 and 5 in transit, this
would return the slot
+ * for message 3. If there are no messages in transit, returns the next
slot on which a message will be inserted.
+ */
+ private String getCurrentLowestSlot() {
+ QueuedMessage[] queue = getSendQueue();
+ if (queue.length > 0) {
+ int messageWithHighestUid = 0;
+ for (int i = 0; i < queue.length; i++) {
+ if (queue[i] == null) continue;
+ if (queue[i].uid > messageWithHighestUid)
messageWithHighestUid = i;
+ }
+ return queue[messageWithHighestUid].slot;
+ } else {
+ String retval = this.contactfile.get("nextslot");
+ if (retval != null) {
+ return retval;
+ } else {
+ Logger.minor(this, "Generating first slot for
contact");
+ SecureRandom rnd = new SecureRandom();
+ SHA256Digest sha256 = new SHA256Digest();
+ byte[] buf = new byte[sha256.getDigestSize()];
+
+ rnd.nextBytes(buf);
+
+ String firstSlot = Base32.encode(buf);
+
+ this.contactfile.put("nextslot",
Base32.encode(buf));
+
+ return firstSlot;
+ }
+ }
}
private byte[] getAESParams() {
@@ -318,7 +340,7 @@
Logger.normal(this, "Initialising Outbound Contact
"+address.toString());
// try to fetch get all necessary info. will fetch mailsite /
generate new keys if necessary
- String initialslot = this.getInitialSlot();
+ String initialslot = this.getCurrentLowestSlot();
SSKKeyPair commssk = this.getCommKeyPair();
if (commssk == null) return false;
SSKKeyPair ackssk = this.getAckKeyPair();
@@ -481,6 +503,19 @@
}
private boolean fetchMailSite() throws OutboundContactFatalException,
ConnectionTerminatedException {
+ String lastFetchedStr = this.contactfile.get("lastfetched");
+ long lastFetched = 0;
+ if (lastFetchedStr != null) {
+ lastFetched = Long.parseLong(lastFetchedStr);
+ }
+ if (lastFetched > System.currentTimeMillis()) {
+ Logger.error(this, "Mailsite was apparently last
fetched in the future! System time gone backwards? Refetching.");
+ lastFetched = 0;
+ }
+ if (lastFetched > System.currentTimeMillis() -
MAILSITE_CACHE_TIME) {
+ return true;
+ }
+
HighLevelFCPClient cli = new HighLevelFCPClient();
Logger.normal(this,"Attempting to fetch
"+this.address.getMailpageKey());
@@ -503,15 +538,16 @@
mailsite_file.delete();
if (rtsksk == null || keymod_str == null || keyexp_str == null)
{
- // TODO: More failure mechanisms - this is fatal.
+ // Not actually fatal - the other party could publish a
new, valid mailsite
Logger.normal(this,"Mailsite for "+this.address+" does
not contain all necessary information!");
- throw new OutboundContactFatalException("Mailsite for
"+this.address+" does not contain all necessary information!");
+ return false;
}
// add this to a new outbound contact file
this.contactfile.put("rtsksk", rtsksk);
this.contactfile.put("asymkey.modulus", keymod_str);
this.contactfile.put("asymkey.pubexponent", keyexp_str);
+ this.contactfile.put("lastfetched",
Long.toString(System.currentTimeMillis()));
return true;
}
@@ -519,7 +555,8 @@
private String popNextSlot() {
String slot = this.contactfile.get("nextslot");
if (slot == null) {
- slot = this.getInitialSlot();
+ Logger.error(this, "Contact has no 'nextslot' prop!
This shouldn't happen!");
+ return null;
}
SHA256Digest sha256 = new SHA256Digest();
sha256.update(Base32.decode(slot), 0,
Base32.decode(slot).length);
@@ -601,27 +638,23 @@
try {
this.sendQueued();
this.pollAcks();
- try {
- this.checkCTS();
- } catch (OutboundContactFatalException fe) {
- }
+ this.checkCTS();
+ } catch (OutboundContactFatalException fe) {
+ Logger.error(this, "Fatal exception on outbound
contact: "+fe.getMessage()+". This contact in invalid.");
+ // TODO: probably bounce all the messages and delete
the contact.
} catch (ConnectionTerminatedException cte) {
// just exit
}
}
- private void sendQueued() throws ConnectionTerminatedException {
+ private void sendQueued() throws ConnectionTerminatedException,
OutboundContactFatalException {
boolean ready;
String ctstatus = this.contactfile.get("status");
if (ctstatus == null) ctstatus = "notsent";
if (ctstatus.equals("rts-sent") ||
ctstatus.equals("cts-received")) {
ready = true;
} else {
- try {
- ready = this.init();
- } catch (OutboundContactFatalException fe) {
- ready = false;
- }
+ ready = this.init();
}
HighLevelFCPClient fcpcli = null;
@@ -690,7 +723,7 @@
}
}
- private void pollAcks() throws ConnectionTerminatedException {
+ private void pollAcks() throws ConnectionTerminatedException,
OutboundContactFatalException {
HighLevelFCPClient fcpcli = null;
QueuedMessage[] msgs = this.getSendQueue();
@@ -733,11 +766,12 @@
+"If you
believe this is likely, try resending the message.", true);
Logger.normal(this,"Giving up
on message - been trying for too long.");
msgs[i].delete();
- } else if (System.currentTimeMillis() >
msgs[i].last_send_time + RETRANSMIT_DELAY) {
- // no ack yet - retransmit on
another slot
- msgs[i].slot =
this.popNextSlot();
- // mark for re-insertion
- msgs[i].last_send_time = -1;
+ } else if (System.currentTimeMillis() >
msgs[i].last_send_time + RTS_RETRANSMIT_DELAY) {
+ Logger.normal(this, "Resending
RTS for contact");
+ init();
+ // bit of a fudge - this won't
actually be the last send time, since we won't re-send messages at all now,
+ // it will be the last time the
RTS was sent.
+ msgs[i].last_send_time =
System.currentTimeMillis();
msgs[i].saveProps();
}
}
