/**
* "Generate contents for the given BlockInfoVec on the given Link." [DTN2]
*
* @return "the total length of the formatted blocks for this bundle." [DTN2]
*/
public static int generate_blocks(Bundle bundle, BlockInfoVec blocks, final Link link) {
// "now assert there's at least 2 blocks (primary + payload) and
// that the primary is first" [DTN2]
assert (blocks.size() >= 2);
assert (blocks.front().type() == bundle_block_type_t.PRIMARY_BLOCK);
// "now we make a pass through the list and call generate on
// each block processor" [DTN2]
for (int i = 0; i < blocks.size(); i++) {
boolean last = i == blocks.size() - 1;
BlockInfo iter = blocks.get(i);
iter.owner().generate(bundle, blocks, iter, link, last);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"generated block (owner %s type %s) "
+ "data_offset %d data_length %d , contents_length %d",
iter.owner().block_type(),
iter.type(),
iter.data_offset(),
iter.data_length(),
iter.contents().position()));
if (last) {
assert ((iter.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) != 0);
} else {
assert ((iter.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) == 0);
}
}
// "Now that all the EID references are added to the dictionary,
// generate the primary block." [DTN2]
PrimaryBlockProcessor pbp =
(PrimaryBlockProcessor) find_processor(BundleProtocol.bundle_block_type_t.PRIMARY_BLOCK);
assert (blocks.front().owner() == pbp);
pbp.generate_primary(bundle, blocks, blocks.front());
// "make a final pass through, calling finalize() and extracting
// the block length" [DTN2]
int total_len = 0;
for (int i = blocks.size() - 1; i >= 0; i--) {
BlockInfo iter = blocks.get(i);
iter.owner().finalize(bundle, blocks, iter, link);
total_len += iter.full_length();
}
return total_len;
}
/**
* "Temporary helper function to find the offset of the first byte of the payload in a
* BlockInfoVec." [DTN2]
*/
public static int payload_offset(final BlockInfoVec blocks) {
int ret = 0;
Iterator<BlockInfo> itr = blocks.iterator();
while (itr.hasNext()) {
BlockInfo block = itr.next();
if (block.type() == BundleProtocol.bundle_block_type_t.PAYLOAD_BLOCK) {
ret += block.data_offset();
return ret;
}
ret += block.full_length();
}
return ret;
}
/**
* "Loop through the bundle's received block list to validate each entry." [DTN2]
*
* @return "true if the bundle is valid, false if it should be deleted." [DTN2]
*/
public static boolean validate(
Bundle bundle,
status_report_reason_t[] reception_reason,
status_report_reason_t[] deletion_reason) {
int primary_blocks = 0, payload_blocks = 0;
BlockInfoVec recv_blocks = bundle.recv_blocks();
// "a bundle must include at least two blocks (primary and payload)"
// [DTN2]
if (recv_blocks.size() < 2) {
BPF.getInstance().getBPFLogger().error(TAG, "bundle fails to contain at least two blocks");
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
}
// "the first block of a bundle must be a primary block" [DTN2]
if (recv_blocks.front().type() != BundleProtocol.bundle_block_type_t.PRIMARY_BLOCK) {
BPF.getInstance().getBPFLogger().error(TAG, "bundle fails to contain a primary block");
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
}
// "validate each individual block" [DTN2]
int last_block_index = recv_blocks.size() - 1;
for (int i = 0; i < recv_blocks.size(); i++) {
BlockInfo current_block = recv_blocks.get(i);
// "a block may not have enough data for the preamble" [DTN2]
if (current_block.data_offset() == 0) {
// "either the block is not the last one and something went
// badly wrong, or it is the last block present" [DTN2]
if (i != last_block_index) {
BPF.getInstance().getBPFLogger().error(TAG, "bundle block too short for the preamble");
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
}
// "this is the last block, so drop it" [DTN2]
BPF.getInstance().getBPFLogger().debug(TAG, "forgetting preamble-starved last block");
recv_blocks.remove(current_block);
if (recv_blocks.size() < 2) {
BPF.getInstance()
.getBPFLogger()
.error(TAG, "bundle fails to contain at least two blocks");
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
}
// "continue with the tests; results may have changed now that
// a different block is last" [DTN2]
return false;
} else {
if (current_block.type() == BundleProtocol.bundle_block_type_t.PRIMARY_BLOCK) {
primary_blocks++;
}
if (current_block.type() == BundleProtocol.bundle_block_type_t.PAYLOAD_BLOCK) {
payload_blocks++;
}
}
if (!current_block
.owner()
.validate(bundle, recv_blocks, current_block, reception_reason, deletion_reason)) {
return false;
}
// "a bundle's last block must be flagged as such,
// and all other blocks should not be flagged" [DTN2]
if (i == last_block_index) {
if (!current_block.last_block()) {
if (!bundle.fragmented_incoming()) {
BPF.getInstance().getBPFLogger().error(TAG, "bundle's last block not flagged");
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
} else {
BPF.getInstance()
.getBPFLogger()
.debug(TAG, "bundle's last block not flagged, but " + "it is a reactive fragment");
}
}
} else {
if (current_block.last_block()) {
BPF.getInstance().getBPFLogger().error(TAG, "bundle block incorrectly flagged as last");
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
}
}
}
// "a bundle must contain one, and only one, primary block" [DTN2]
if (primary_blocks != 1) {
BPF.getInstance()
.getBPFLogger()
.error(TAG, String.format("bundle contains %d primary blocks", primary_blocks));
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
}
// "a bundle must not contain more than one payload block" [DTN2]
if (payload_blocks > 1) {
BPF.getInstance()
.getBPFLogger()
.error(TAG, String.format("bundle contains %d payload blocks", payload_blocks));
deletion_reason[0] = BundleProtocol.status_report_reason_t.REASON_BLOCK_UNINTELLIGIBLE;
return false;
}
return true;
}
/**
* "Parse the supplied chunk of arriving data and append it to the rcvd_blocks_ list in the given
* bundle, finding the appropriate BlockProcessor element and calling its receive() handler.
*
* <p>When called repeatedly for arriving chunks of data, this properly fills in the entire
* bundle, including the in_blocks_ record of the arriving blocks and the payload (which is stored
* externally)." [DTN2]
*
* @return "the length of data consumed or -1 on protocol error, plus sets last to true if the
* bundle is complete." [DTN2]
*/
public static int consume(Bundle bundle, IByteBuffer data, int len, boolean[] last) {
int old_position = data.position();
int origlen = len;
last[0] = false;
BlockInfoVec recv_blocks = bundle.recv_blocks();
// "special case for first time we get called, since we need to
// create a BlockInfo struct for the primary block without knowing
// the typecode or the length" [DTN2]
if (recv_blocks.isEmpty()) {
BPF.getInstance()
.getBPFLogger()
.debug(TAG, "consume: got first block... " + "creating primary block info");
recv_blocks.append_block(find_processor(bundle_block_type_t.PRIMARY_BLOCK), null);
}
// "loop as long as there is data left to process" [DTN2]
while (len != 0) {
BPF.getInstance()
.getBPFLogger()
.debug(TAG, String.format("consume: %d bytes left to process", len));
BlockInfo info = recv_blocks.back();
// "if the last received block is complete, create a new one
// and push it onto the vector. at this stage we consume all
// blocks, even if there's no BlockProcessor that understands
// how to parse it" [DTN2]
if (info.complete()) {
data.mark();
byte bundle_block_type_byte = data.get();
bundle_block_type_t type = bundle_block_type_t.get(bundle_block_type_byte);
data.reset();
info = recv_blocks.append_block(find_processor(type), null);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"consume: previous block complete, " + "created new BlockInfo type %s",
info.owner().block_type()));
}
// "now we know that the block isn't complete, so we tell it to
// consume a chunk of data" [DTN2]
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"consume: block processor %s type %s incomplete, "
+ "calling consume (%d bytes already buffered)",
info.owner().block_type(), info.type(), info.contents().position()));
int cc = info.owner().consume(bundle, info, data, len);
if (cc < 0) {
BPF.getInstance()
.getBPFLogger()
.error(TAG, String.format("consume: protocol error handling block %s", info.type()));
return -1;
}
// "decrement the amount that was just handled from the overall
// total. verify that the block was either completed or
// consumed all the data that was passed in." [DTN2]
len -= cc;
data.position(data.position() + cc);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"consume: consumed %d bytes of block type %s (%s)",
cc, info.type(), info.complete() ? "complete" : "not complete"));
if (info.complete()) {
// check if we're done with the bundle
if ((info.flags() & block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode()) > 0) {
last[0] = true;
break;
}
} else {
assert (len == 0);
}
}
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"bundle id %d consume completed, %d/%d bytes consumed %s",
bundle.bundleid(), origlen - len, origlen, last[0] ? "(completed bundle)" : ""));
data.position(old_position);
return origlen - len;
}
/**
* "Copies out a chunk of formatted bundle data at a specified offset from the provided
* BlockInfoVec." [DTN2]
*
* @return "the length of the chunk produced (up to the supplied length) and sets last to true if
* the bundle is complete." [DTN2]
*/
public static int produce(
final Bundle bundle,
final BlockInfoVec blocks,
IByteBuffer data,
int offset,
int len,
boolean[] last) {
int old_position = data.position();
int origlen = len;
last[0] = false;
if (len == 0) return 0;
assert (!blocks.isEmpty());
Iterator<BlockInfo> iter = blocks.iterator();
BlockInfo current_block = iter.next();
// "advance past any blocks that are skipped by the given offset."[DTN2]
while (offset >= current_block.full_length()) {
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce skipping block type %s "
+ "since offset %d >= block length %d",
current_block.type().toString(), offset, current_block.full_length()));
offset -= current_block.full_length();
current_block = iter.next();
}
// "the offset value now should be within the current block" [DTN2]
while (true) {
// The first time remainder will be minus from leftover offset above
// but later on it will be the full content of the block
int remainder = current_block.full_length() - offset;
int tocopy = Math.min(len, remainder);
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce copying %d/%d bytes from "
+ "block type %s at offset %d",
tocopy, remainder, current_block.type().toString(), offset));
current_block.owner().produce(bundle, current_block, data, offset, tocopy);
len -= tocopy;
// move the position of IByteBuffer
data.position(data.position() + tocopy);
// "if we've copied out the full amount the user asked for,
// we're done. note that we need to check the corner case
// where we completed the block exactly to properly set the
// last bit" [DTN2]
if (len == 0) {
if ((tocopy == remainder)
&& ((current_block.flags()
& BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode())
> 0)) {
last[0] = true;
}
break;
}
// "we completed the current block, so we're done if this
// is the last block, even if there's space in the user buffer"
// [DTN2]
assert (tocopy == remainder);
if ((current_block.flags() & BundleProtocol.block_flag_t.BLOCK_FLAG_LAST_BLOCK.getCode())
> 0) {
last[0] = true;
break;
}
// advance to next block
current_block = iter.next();
offset = 0;
}
BPF.getInstance()
.getBPFLogger()
.debug(
TAG,
String.format(
"BundleProtocol::produce complete: "
+ "produced %d bytes, bundle id %d, status is %s",
origlen - len, bundle.bundleid(), last[0] ? "complete" : "not complete"));
data.position(old_position);
return origlen - len;
}