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Implemented fragmenting IP packets - not yet tested, though. 

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19053 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Axel Dörfler 2006-10-13 06:00:19 +00:00
parent bdfed6c06f
commit 5450af8220
1 changed files with 82 additions and 5 deletions
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87
src/add-ons/kernel/network/protocols/ipv4/ipv4.cpp
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@ -557,6 +557,84 @@ reassemble_fragments(const ipv4_header &header, net_buffer **_buffer)
}
/*!
Fragments the incoming buffer and send all fragments via the specified
\a route.
*/
static status_t
send_fragments(ipv4_protocol *protocol, struct net_route *route,
net_buffer *buffer, uint32 mtu)
{
dprintf("ipv4 needs to fragment (size %lu, MTU %lu), but that's not yet tested...\n",
buffer->size, mtu);
// adapt MTU to be a multiple of 8 (fragment offsets can only be specified this way)
mtu &= ~7;
dprintf(" adjusted MTU to %ld\n", mtu);
NetBufferHeader<ipv4_header> bufferHeader(buffer);
if (bufferHeader.Status() < B_OK)
return bufferHeader.Status();
ipv4_header &header = bufferHeader.Data();
bufferHeader.Detach();
uint16 headerLength = header.HeaderLength();
uint32 bytesLeft = buffer->size - headerLength;
uint32 fragmentOffset = 0;
status_t status = B_OK;
net_buffer *headerBuffer = sBufferModule->split(buffer, headerLength);
if (headerBuffer == NULL)
return B_NO_MEMORY;
while (bytesLeft > 0) {
uint32 fragmentLength = max_c(bytesLeft, mtu);
bytesLeft -= fragmentLength;
bool lastFragment = bytesLeft == 0;
header.total_length = htons(fragmentLength);
header.fragment_offset = htons((lastFragment ? 0 : IP_MORE_FRAGMENTS)
| (fragmentOffset >> 3));
header.checksum = sBufferModule->checksum(buffer, 0, sizeof(ipv4_header), true);
// TODO: compute the checksum only for those parts that changed?
dprintf(" send fragment of %ld bytes (%ld bytes left)\n", fragmentLength, bytesLeft);
net_buffer *fragmentBuffer;
if (!lastFragment) {
fragmentBuffer = sBufferModule->split(buffer, fragmentLength);
fragmentOffset += fragmentLength;
} else
fragmentBuffer = buffer;
if (fragmentBuffer == NULL) {
status = B_NO_MEMORY;
break;
}
// copy header to fragment
status = sBufferModule->prepend(fragmentBuffer, &header, headerLength);
// send fragment
if (status == B_OK)
status = sDatalinkModule->send_data(route, fragmentBuffer);
if (lastFragment) {
// we don't own the last buffer, so we don't have to free it
break;
}
if (status < B_OK) {
sBufferModule->free(fragmentBuffer);
break;
}
}
sBufferModule->free(headerBuffer);
return status;
}
static void
raw_receive_data(net_buffer *buffer)
{
@ -809,16 +887,15 @@ ipv4_send_routed_data(net_protocol *_protocol, struct net_route *route,
sBufferModule->checksum(buffer, 0, sizeof(ipv4_header), true),
sBufferModule->checksum(buffer, 0, buffer->size, true)));
TRACE(("destination-IP: buffer=%p addr=%p %08lx\n", buffer, &buffer->destination,
ntohl(((sockaddr_in *)&buffer->destination)->sin_addr.s_addr)));
uint32 mtu = route->mtu ? route->mtu : interface->mtu;
if (buffer->size > mtu) {
// we need to fragment the packet
dprintf("ipv4 needs to fragment (size %lu, MTU %lu), but that's not yet implemented...\n", buffer->size, mtu);
return B_ERROR;
return send_fragments(protocol, route, buffer, mtu);
}
TRACE(("destination-IP: buffer=%p addr=%p %08lx\n", buffer, &buffer->destination,
ntohl(((sockaddr_in *)&buffer->destination)->sin_addr.s_addr)));
return sDatalinkModule->send_data(route, buffer);
}