From f12fb1e2f88e29c8060dfe673b65a315a84c1b29 Mon Sep 17 00:00:00 2001 From: cbdev Date: Fri, 6 Mar 2020 00:44:26 +0100 Subject: Implement (optional) rate-limiting for sACN --- backends/sacn.c | 78 ++++++++++++++++++++++++++++++++++++++++++-------------- backends/sacn.h | 17 +++++++++--- backends/sacn.md | 4 +-- 3 files changed, 74 insertions(+), 25 deletions(-) diff --git a/backends/sacn.c b/backends/sacn.c index 5096123..6c08b5a 100644 --- a/backends/sacn.c +++ b/backends/sacn.c @@ -28,12 +28,14 @@ static struct /*_sacn_global_config*/ { size_t fds; sacn_fd* fd; uint64_t last_announce; + uint32_t next_frame; } global_cfg = { .source_name = "MIDIMonster", .cid = {'M', 'I', 'D', 'I', 'M', 'o', 'n', 's', 't', 'e', 'r'}, .fds = 0, .fd = NULL, - .last_announce = 0 + .last_announce = 0, + .next_frame = 0 }; MM_PLUGIN_API int init(){ @@ -46,6 +48,7 @@ MM_PLUGIN_API int init(){ .handle = sacn_set, .process = sacn_handle, .start = sacn_start, + .interval = sacn_interval, .shutdown = sacn_shutdown }; @@ -63,6 +66,13 @@ MM_PLUGIN_API int init(){ return 0; } +static uint32_t sacn_interval(){ + if(global_cfg.next_frame){ + return global_cfg.next_frame; + } + return SACN_KEEPALIVE_INTERVAL; +} + static int sacn_listener(char* host, char* port, uint8_t flags){ int fd = -1, yes = 1; if(global_cfg.fds >= MAX_FDS){ @@ -87,7 +97,6 @@ static int sacn_listener(char* host, char* port, uint8_t flags){ global_cfg.fd[global_cfg.fds].fd = fd; global_cfg.fd[global_cfg.fds].universes = 0; global_cfg.fd[global_cfg.fds].universe = NULL; - global_cfg.fd[global_cfg.fds].last_frame = NULL; if(flags & mcast_loop){ //set IP_MCAST_LOOP to allow local applications to receive output @@ -190,6 +199,10 @@ static int sacn_configure_instance(instance* inst, char* option, char* value){ data->unicast_input = strtoul(value, NULL, 10); return 0; } + else if(!strcmp(option, "realtime")){ + data->realtime = strtoul(value, NULL, 10); + return 0; + } LOGPF("Unknown instance configuration option %s for instance %s", option, inst->name); return 1; @@ -289,10 +302,11 @@ static int sacn_transmit(instance* inst){ LOGPF("Failed to output frame for instance %s: %s", inst->name, strerror(errno)); } - //update last transmit timestamp + //update last transmit timestamp, unmark instance for(u = 0; u < global_cfg.fd[data->fd_index].universes; u++){ - if(global_cfg.fd[data->fd_index].universe[u] == data->uni){ - global_cfg.fd[data->fd_index].last_frame[u] = mm_timestamp(); + if(global_cfg.fd[data->fd_index].universe[u].universe == data->uni){ + global_cfg.fd[data->fd_index].universe[u].last_frame = mm_timestamp(); + global_cfg.fd[data->fd_index].universe[u].mark = 0; } } return 0; @@ -300,6 +314,7 @@ static int sacn_transmit(instance* inst){ static int sacn_set(instance* inst, size_t num, channel** c, channel_value* v){ size_t u, mark = 0; + uint32_t frame_delta = 0; sacn_instance_data* data = (sacn_instance_data*) inst->impl; if(!num){ @@ -333,6 +348,25 @@ static int sacn_set(instance* inst, size_t num, channel** c, channel_value* v){ //send packet if required if(mark){ + if(!data->realtime){ + //find output instance data + for(u = 0; u < global_cfg.fd[data->fd_index].universes; u++){ + if(global_cfg.fd[data->fd_index].universe[u].universe == data->uni){ + break; + } + } + + frame_delta = mm_timestamp() - global_cfg.fd[data->fd_index].universe[u].last_frame; + + //check if ratelimiting engaged + if(frame_delta < SACN_FRAME_TIMEOUT){ + global_cfg.fd[data->fd_index].universe[u].mark = 1; + if(!global_cfg.next_frame || global_cfg.next_frame > (SACN_KEEPALIVE_INTERVAL - frame_delta)){ + global_cfg.next_frame = (SACN_KEEPALIVE_INTERVAL - frame_delta); + } + return 0; + } + } sacn_transmit(inst); } @@ -468,6 +502,7 @@ static void sacn_discovery(size_t fd){ static int sacn_handle(size_t num, managed_fd* fds){ size_t u, c; uint64_t timestamp = mm_timestamp(); + uint32_t synthesize_delta = 0; ssize_t bytes_read; char recv_buf[SACN_RECV_BUF]; instance* inst = NULL; @@ -477,7 +512,7 @@ static int sacn_handle(size_t num, managed_fd* fds){ sacn_frame_root* frame = (sacn_frame_root*) recv_buf; sacn_frame_data* data = (sacn_frame_data*) (recv_buf + sizeof(sacn_frame_root)); - if(mm_timestamp() - global_cfg.last_announce > SACN_DISCOVERY_TIMEOUT){ + if(timestamp - global_cfg.last_announce > SACN_DISCOVERY_TIMEOUT){ //send universe discovery pdu for(u = 0; u < global_cfg.fds; u++){ if(global_cfg.fd[u].universes){ @@ -487,17 +522,28 @@ static int sacn_handle(size_t num, managed_fd* fds){ global_cfg.last_announce = timestamp; } - //check for keepalive frames + //check for keepalive frames, synthesize frames if necessary for(u = 0; u < global_cfg.fds; u++){ for(c = 0; c < global_cfg.fd[u].universes; c++){ - if(timestamp - global_cfg.fd[u].last_frame[c] >= SACN_KEEPALIVE_INTERVAL){ + synthesize_delta = timestamp - global_cfg.fd[u].universe[c].last_frame; + + if((global_cfg.fd[u].universe[c].mark + && synthesize_delta >= SACN_FRAME_TIMEOUT + SACN_SYNTHESIZE_MARGIN) + || synthesize_delta >= SACN_KEEPALIVE_INTERVAL){ instance_id.fields.fd_index = u; - instance_id.fields.uni = global_cfg.fd[u].universe[c]; + instance_id.fields.uni = global_cfg.fd[u].universe[c].universe; inst = mm_instance_find(BACKEND_NAME, instance_id.label); if(inst){ sacn_transmit(inst); } } + + //update next frame request + if(global_cfg.fd[u].universe[c].mark + && (!global_cfg.next_frame || global_cfg.next_frame > SACN_FRAME_TIMEOUT + SACN_SYNTHESIZE_MARGIN - synthesize_delta)){ + global_cfg.next_frame = SACN_FRAME_TIMEOUT + SACN_SYNTHESIZE_MARGIN - synthesize_delta; + } + } } @@ -557,7 +603,6 @@ static int sacn_start(size_t n, instance** inst){ if(!global_cfg.fds){ LOG("Failed to start, no descriptors bound"); - free(inst); return 1; } @@ -590,13 +635,15 @@ static int sacn_start(size_t n, instance** inst){ if(data->xmit_prio){ //add to list of advertised universes for this fd - global_cfg.fd[data->fd_index].universe = realloc(global_cfg.fd[data->fd_index].universe, (global_cfg.fd[data->fd_index].universes + 1) * sizeof(uint16_t)); + global_cfg.fd[data->fd_index].universe = realloc(global_cfg.fd[data->fd_index].universe, (global_cfg.fd[data->fd_index].universes + 1) * sizeof(sacn_output_universe)); if(!global_cfg.fd[data->fd_index].universe){ LOG("Failed to allocate memory"); goto bail; } - global_cfg.fd[data->fd_index].universe[global_cfg.fd[data->fd_index].universes] = data->uni; + global_cfg.fd[data->fd_index].universe[global_cfg.fd[data->fd_index].universes].universe = data->uni; + global_cfg.fd[data->fd_index].universe[global_cfg.fd[data->fd_index].universes].last_frame = 0; + global_cfg.fd[data->fd_index].universe[global_cfg.fd[data->fd_index].universes].mark = 0; global_cfg.fd[data->fd_index].universes++; //generate multicast destination address if none set @@ -612,12 +659,6 @@ static int sacn_start(size_t n, instance** inst){ LOGPF("Registering %" PRIsize_t " descriptors to core", global_cfg.fds); for(u = 0; u < global_cfg.fds; u++){ - //allocate memory for storing last frame transmission timestamp - global_cfg.fd[u].last_frame = calloc(global_cfg.fd[u].universes, sizeof(uint64_t)); - if(!global_cfg.fd[u].last_frame){ - LOG("Failed to allocate memory"); - goto bail; - } if(mm_manage_fd(global_cfg.fd[u].fd, BACKEND_NAME, 1, (void*) u)){ goto bail; } @@ -638,7 +679,6 @@ static int sacn_shutdown(size_t n, instance** inst){ for(p = 0; p < global_cfg.fds; p++){ close(global_cfg.fd[p].fd); free(global_cfg.fd[p].universe); - free(global_cfg.fd[p].last_frame); } free(global_cfg.fd); LOG("Backend shut down"); diff --git a/backends/sacn.h b/backends/sacn.h index ac59441..4642e59 100644 --- a/backends/sacn.h +++ b/backends/sacn.h @@ -1,6 +1,7 @@ #include "midimonster.h" MM_PLUGIN_API int init(); +static uint32_t sacn_interval(); static int sacn_configure(char* option, char* value); static int sacn_configure_instance(instance* instance, char* option, char* value); static int sacn_instance(instance* inst); @@ -12,7 +13,11 @@ static int sacn_shutdown(size_t n, instance** inst); #define SACN_PORT "5568" #define SACN_RECV_BUF 8192 -#define SACN_KEEPALIVE_INTERVAL 2000 +//spec 6.6.2.1 +#define SACN_KEEPALIVE_INTERVAL 1000 +//spec 6.6.1 +#define SACN_FRAME_TIMEOUT 15 +#define SACN_SYNTHESIZE_MARGIN 10 #define SACN_DISCOVERY_TIMEOUT 9000 #define SACN_PDU_MAGIC "ASC-E1.17\0\0\0" @@ -35,6 +40,7 @@ typedef struct /*_sacn_universe_model*/ { typedef struct /*_sacn_instance_model*/ { uint16_t uni; + uint8_t realtime; uint8_t xmit_prio; uint8_t cid_filter[16]; uint8_t filter_enabled; @@ -54,11 +60,16 @@ typedef union /*_sacn_instance_id*/ { uint64_t label; } sacn_instance_id; +typedef struct /*_sacn_output_universe*/ { + uint16_t universe; + uint64_t last_frame; + uint8_t mark; +} sacn_output_universe; + typedef struct /*_sacn_socket*/ { int fd; size_t universes; - uint16_t* universe; - uint64_t* last_frame; + sacn_output_universe* universe; } sacn_fd; #pragma pack(push, 1) diff --git a/backends/sacn.md b/backends/sacn.md index f5f1db4..598f430 100644 --- a/backends/sacn.md +++ b/backends/sacn.md @@ -26,6 +26,7 @@ This has the side effect of mirroring the output of instances on those descripto | `destination` | `10.2.2.2` | Universe multicast | Destination address for unicast output. If unset, the multicast destination for the specified universe is used. | | `from` | `0xAA 0xBB` ... | none | 16-byte input source CID filter. Setting this option filters the input stream for this universe. | | `unicast` | `1` | `0` | Prevent this instance from joining its universe multicast group | +| `realtime` | `1` | `0` | Disable the recommended rate-limiting (approx. 44 packets per second) for this instance | Note that instances accepting multicast input also process unicast frames directed at them, while instances in `unicast` mode will not receive multicast frames. @@ -50,9 +51,6 @@ A normal channel that is part of a wide channel can not be mapped individually. The DMX start code of transmitted and received universes is fixed as `0`. -The (upper) limit on packet transmission rate mandated by section 6.6.1 of the sACN specification is disregarded. -The rate of packet transmission is influenced by the rate of incoming mapped events on the instance. - Universe synchronization is currently not supported, though this feature may be implemented in the future. To use multicast input, all networking hardware in the path must support the IGMPv2 protocol. -- cgit v1.2.3