ouroboros/src/lib, branch 0.18.0

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

lib: Fix flow_accept without openssl

2020-12-12T10:37:56+00:00

DH key creation was returning -ECRYPT if opennssl is not installed, instead of success (0). Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Fix return value in function returning void

2020-12-12T10:37:50+00:00

This causes builds to fail on systems where OpenSSL is not available. 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: Reduce timerwheel CPU consumption

2020-11-25T14:35:27+00:00

The timerwheel is checked during IPC calls (fevent, flow_read), causing huge load on CPU consumption in IPCPs, since they have a lot of fevent() threads for QoS. The timerwheel will need further optimization), but for now I reduced the default tick time to 5 ms and added a boolean to check that the wheel is actually used. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Don't default to lockless rbuff

2020-11-22T11:04:03+00:00

I mistakenly set the default to the (buggy) lockless rbuff implementation instead of the pthread one in commit 3aec660e. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

Revert "lib: Unmount stale RIB directories"

2020-11-11T11:14:19+00:00

This reverts commit 978266fe4beba21292daad2d341fe5ff22e08aba. We were incorrectly unmounting the directory under normal conditions. Signed-off-by: Sander Vrijders Signed-off-by: Dimitri Staessens

lib: Add Rendez-Vous mechanism for flow control

2020-10-11T12:47:52+00:00

This adds the rendez-vous mechanism to handle the case where the sending window is closed and window updates get lost. If the sending window is closed, the sender side will send an RDVS every DELT_RDV time (100ms), and give up after MAX_RDV time (1 second). Upon reception of a RDVS packet, a window update is sent immediately. We can make this much more configurable later on (build options for defaults, fccntl for runtime tuning). Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders