ouroboros/include, branch 0.18.2

lib, ipcpd, irmd: Wrap pthread unlocks for cleanup

2021-06-23T06:36:48+00:00

This add an ouroboros/pthread.h header that wraps the pthread_..._unlock() functions for cleanup using pthread_cleanup_push() as this casting is not safe (and there were definitely bad casts in the code). The close() function is now also wrapped for cleanup in ouroboros/sockets.h. This allows enabling more compiler checks. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Remove raptor IPCP

2021-03-28T10:46:05+00:00

This removes the raptor IPCP. The code hasn't been updated for a while, and wouldn't compile. Raptor served its purpose as a PoC for Ouroboros-over-Ethernet-Layer-1, but giving the extreme niche hardware needed to run it, it's not worth maintaining this anymore. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

ipcpd: Single UDP port for the ipcpd-udp

2021-01-03T10:59:59+00:00

The UDP layer will now use a single (configurable) UDP port, default 3435. This makes it easer to allocate flows as a client from behind a NAT firewall without having to configure port forwarding rules. So basically, from now on Ouroboros traffic is transported over a bidirectional : UDP tunnel. The reason for not using/allowing different client/server ports is that it would require reading from different sockets using select() or something similar, but since we need the EID anyway (mgmt packets arrive on the same server UDP port), there's not a lot of benefit in doing it. Now the operation is similar to the ipcpd-eth, with the port somewhat functioning as a "layer name", where in UDP, the Ethertype functions as a "layer name". Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update email addresses

2021-01-03T10:57:05+00:00

The ugent email addresses are shut down, updated to Ouroboros mail addresses. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2021

2021-01-03T10:56:28+00:00

Happy New Year, Ouroboros! Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

ipcpd: Add congestion avoidance policies

2020-12-02T18:21:29+00:00

This adds congestion avoidance policies to the unicast IPCP. The default policy is a multi-bit explicit congestion avoidance algorithm based on data-center TCP congestion avoidance (DCTCP) to relay information about the maximum queue depth that packets experienced to the receiver. There's also a "nop" policy to disable congestion avoidance for testing and benchmarking purposes. The (initial) API for congestion avoidance policies is: void * (* ctx_create)(void); void (* ctx_destroy)(void * ctx); These calls create / and or destroy a context for congestion control for a specific flow. Thread-safety of the context is the responsability of the flow allocator (operations on the ctx should be performed under a lock). ca_wnd_t (* ctx_update_snd)(void * ctx, size_t len); This is the sender call to update the context, and should be called for every packet that is sent on the flow. The len parameter in this API is the packet length, which allows calculating the bandwidth. It returns an opaque union type that is used for the call to check/wait if the congestion window is open or closed (and allowing to release locks before waiting). bool (* ctx_update_rcv)(void * ctx, size_t len, uint8_t ecn, uint16_t * ece); This is the call to update the flow congestion context on the receiver side. It should be called for every received packet. It gets the ecn value from the packet and its length, and returns the ECE (explicit congestion experienced) value to be sent to the sender in case of congestion. The boolean returned signals whether or not a congestion update needs to be sent. void (* ctx_update_ece)(void * ctx, uint16_t ece); This is the call for the sending side top update the context when it receives an ECE update from the receiver. void (* wnd_wait)(ca_wnd_t wnd); This is a (blocking) call that waits for the congestion window to clear. It should be stateless (to avoid waiting under locks). This may change later on if passing the context is needed for different algorithms. uint8_t (* calc_ecn)(int fd, size_t len); This is the call that intermediate IPCPs(routers) should use to update the ECN field on passing packets. The multi-bit ECN policy bases the value for the ECN field on the depth of the rbuff queue packets will be sent on. I created another call to grab the queue depth as fccntl is write-locking the application. We can further optimize this to avoid most locking on the rbuff. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Send and receive window updates

2020-10-11T12:23:44+00:00

This adds sending and receiving window updates for flow control. I used the 8 pad bits as part of the window update field, so it's 24 bits, allowing for ~16 million packets in flight. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Complete retransmission logic

2020-09-25T09:52:51+00:00

This completes the retransmission (automated repeat-request, ARQ) logic, sending (delayed) ACK messages when needed. On deallocation, flows will ACK try to retransmit any remaining unacknowledged messages (unless the FRCTFLINGER flag is turned off; this is on by default). Applications can safely shut down as soon as everything is ACK'd (i.e. the current Delta-t run is done). The activity timeout is now passed to the IPCP for it to sleep before completing deallocation (and releasing the flow_id). That should be moved to the IRMd in due time. The timerwheel is revised to be multi-level to reduce memory consumption. The resolution bumps by a factor of 1 << RXMQ_BUMP (16) and each level has RXMQ_SLOTS (1 << 8) slots. The lowest level has a resolution of (1 << RXMQ_RES) (20) ns, which is roughly a millisecond. Currently, 3 levels are defined, so the largest delay we can schedule at each level is: Level 0: 256ms Level 1: 4s Level 2: about a minute. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Return number of written bytes on flow_write

2020-03-15T13:30:58+00:00

This is more in line with the write() system call and prepares for partial writes. Partial writes are disabled by default (and not yet implemented). Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Change return type of fevent to ssize_t

2020-03-15T13:26:49+00:00

The return type was still an int, but since it returns the number of events, it should be an ssize_t. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders