diff options
| -rw-r--r-- | backends/rtpmidi.c | 228 | ||||
| -rw-r--r-- | backends/rtpmidi.h | 9 |
2 files changed, 220 insertions, 17 deletions
diff --git a/backends/rtpmidi.c b/backends/rtpmidi.c index 97364cf..9e0a4d4 100644 --- a/backends/rtpmidi.c +++ b/backends/rtpmidi.c @@ -10,6 +10,8 @@ #include "libmmbackend.h" #include "rtpmidi.h" +//#include "../tests/hexdump.c" + //TODO learn peer ssrcs //TODO default mode? //TODO internal loop mode @@ -113,6 +115,10 @@ static int dns_decode_name(uint8_t* buffer, size_t len, size_t start, dns_name* //check whether we have space in the output if(output_offset + DNS_LABEL_LENGTH(current_label) > out->alloc){ out->name = realloc(out->name, (output_offset + DNS_LABEL_LENGTH(current_label) + 2) * sizeof(uint8_t)); + if(!out->name){ + LOG("Failed to allocate memory"); + return 1; + } out->alloc = output_offset + DNS_LABEL_LENGTH(current_label); } @@ -130,6 +136,43 @@ static int dns_decode_name(uint8_t* buffer, size_t len, size_t start, dns_name* return 0; } +static int dns_encode_name(char* name, dns_name* out){ + char* save = NULL, *token = NULL; + out->length = 0; + + for(token = strtok_r(name, ".", &save); token; token = strtok_r(NULL, ".", &save)){ + //make space for this label, its length and a trailing root label + if(out->alloc < out->length + strlen(token) + 1 + 1){ + out->name = realloc(out->name, (out->length + strlen(token) + 2) * sizeof(char)); + if(!out->name){ + LOG("Failed to allocate memory"); + return 1; + } + out->alloc = out->length + strlen(token) + 2; + } + //FIXME check label length before adding + out->name[out->length] = strlen(token); + memcpy(out->name + out->length + 1, token, strlen(token)); + out->length += strlen(token) + 1; + } + + //last-effort allocate a root buffer + if(!out->alloc){ + out->name = calloc(1, sizeof(char)); + if(!out->name){ + LOG("Failed to allocate memory"); + return 1; + } + out->alloc = 1; + } + + //add root label + out->name[out->length] = 0; + out->length++; + + return 0; +} + static uint32_t rtpmidi_interval(){ return max(0, RTPMIDI_SERVICE_INTERVAL - (mm_timestamp() - cfg.last_service)); } @@ -160,7 +203,7 @@ static int rtpmidi_configure(char* option, char* value){ return 1; } -static int rtpmidi_bind_instance(rtpmidi_instance_data* data, char* host, char* port){ +static int rtpmidi_bind_instance(instance* inst, rtpmidi_instance_data* data, char* host, char* port){ struct sockaddr_storage sock_addr = { 0 }; @@ -173,19 +216,26 @@ static int rtpmidi_bind_instance(rtpmidi_instance_data* data, char* host, char* return 1; } + if(getsockname(data->fd, (struct sockaddr*) &sock_addr, &sock_len)){ + LOGPF("Failed to fetch data port information: %s", strerror(errno)); + return 1; + } + //bind control port if(data->mode == apple){ - if(getsockname(data->fd, (struct sockaddr*) &sock_addr, &sock_len)){ - LOGPF("Failed to fetch data port information: %s", strerror(errno)); - return 1; - } - - snprintf(control_port, sizeof(control_port), "%d", be16toh(((struct sockaddr_in*)&sock_addr)->sin_port) - 1); + data->control_port = be16toh(((struct sockaddr_in*) &sock_addr)->sin_port) - 1; + snprintf(control_port, sizeof(control_port), "%d", data->control_port); data->control_fd = mmbackend_socket(host, control_port, SOCK_DGRAM, 1, 0); if(data->control_fd < 0){ - LOGPF("Failed to bind control port %s", control_port); + LOGPF("Failed to bind control port %s for instance %s", control_port, inst->name); return 1; } + + LOGPF("Apple mode instance %s listening on port %d", inst->name, data->control_port); + } + else{ + data->control_port = be16toh(((struct sockaddr_in*)&sock_addr)->sin_port); + LOGPF("Direct mode instance %s listening on port %d", inst->name, data->control_port); } return 0; @@ -334,7 +384,7 @@ static int rtpmidi_configure_instance(instance* inst, char* option, char* value) return 1; } - return rtpmidi_bind_instance(data, host, port); + return rtpmidi_bind_instance(inst, data, host, port); } else if(!strcmp(option, "learn")){ if(data->mode != direct){ @@ -643,6 +693,7 @@ static int rtpmidi_handle_applemidi(instance* inst, int fd, uint8_t* frame, size } else if(command->command == apple_reject){ //just ignore this for now and retry the invitation + LOGPF("Invitation rejected on instance %s", inst->name); } else if(command->command == apple_leave){ //remove peer from list - this comes in on the control port, but we need to remove the data port... @@ -910,6 +961,144 @@ static int rtpmidi_handle_control(instance* inst){ return 0; } +int rtpmidi_mdns_announce(rtpmidi_instance_data* data){ + uint8_t frame[RTPMIDI_PACKET_BUFFER] = ""; + dns_header* hdr = (dns_header*) frame; + dns_rr* rr = NULL; + dns_rr_srv* srv = NULL; + dns_name name = { + .alloc = 0 + }; + size_t offset = 0; + struct sockaddr_in mcast = { + .sin_family = AF_INET, + .sin_port = htobe16(5353), + .sin_addr.s_addr = htobe32(((uint32_t) 0xe00000fb)) + }; + struct sockaddr_in6 mcast6 = { + .sin6_family = AF_INET6, + .sin6_port = htobe16(5353), + .sin6_addr.s6_addr = {0xff, 0x02, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0xfb} + }; + + hdr->id = 0; + hdr->flags[0] = 0x84; + hdr->flags[1] = 0; + hdr->questions = hdr->servers = 0; + hdr->answers = htobe16(4); + hdr->additional = htobe16(1); + offset = sizeof(dns_header); + + //answer 1: SRV FQDN + snprintf((char*) frame + offset, sizeof(frame) - offset, "%s.%s", data->session_name, RTPMIDI_MDNS_DOMAIN); + if(dns_encode_name((char*) frame + offset, &name)){ + LOGPF("Failed to encode name for %s", frame); + return 1; + } + + memcpy(frame + offset, name.name, name.length); + offset += name.length; + + rr = (dns_rr*) (frame + offset); + rr->rtype = htobe16(33); //SRV RR + rr->rclass = htobe16(1); //INADDR + rr->ttl = htobe32(120); + offset += sizeof(dns_rr); + + srv = (dns_rr_srv*) (frame + offset); + srv->priority = 0; + srv->weight = 0; + srv->port = htobe16(data->control_port); + offset += sizeof(dns_rr_srv); + + snprintf((char*) frame + offset, sizeof(frame) - offset, "%s.local", cfg.mdns_name); + if(dns_encode_name((char*) frame + offset, &name)){ + LOGPF("Failed to encode name for %s", frame + offset); + return 1; + } + memcpy(frame + offset, name.name, name.length); + offset += name.length; + rr->data = htobe16(sizeof(dns_rr_srv) + name.length); + + //answer 2: empty TXT (apple asks for it otherwise) + frame[offset++] = 0xC0; + frame[offset++] = sizeof(dns_header); + rr = (dns_rr*) (frame + offset); + rr->rtype = htobe16(16); //TXT RR + rr->rclass = htobe16(1); //INADDR + rr->ttl = htobe32(4500); + rr->data = htobe16(1); + offset += sizeof(dns_rr); + frame[offset++] = 0x00; //zero-length TXT + + //answer 3: dns-sd PTR _applemidi + snprintf((char*) frame + offset, sizeof(frame) - offset, "%s", RTPMIDI_DNSSD_DOMAIN); + if(dns_encode_name((char*) frame + offset, &name)){ + LOGPF("Failed to encode name for %s", frame + offset); + return 1; + } + memcpy(frame + offset, name.name, name.length); + offset += name.length; + + rr = (dns_rr*) (frame + offset); + rr->rtype = htobe16(12); //PTR RR + rr->rclass = htobe16(1); //INADDR + rr->ttl = htobe32(4500); + rr->data = htobe16(2); + offset += sizeof(dns_rr); + + //add backref for PTR + frame[offset++] = 0xC0; + frame[offset++] = sizeof(dns_header) + frame[sizeof(dns_header)] + 1; + + //answer 4: _applemidi PTR FQDN + frame[offset++] = 0xC0; + frame[offset++] = sizeof(dns_header) + frame[sizeof(dns_header)] + 1; + + rr = (dns_rr*) (frame + offset); + rr->rtype = htobe16(12); //PTR RR + rr->rclass = htobe16(1); //INADDR + rr->ttl = htobe32(4500); + rr->data = htobe16(2); + offset += sizeof(dns_rr); + + //add backref for PTR + frame[offset++] = 0xC0; + frame[offset++] = sizeof(dns_header); + + //additional 1: A host + snprintf((char*) frame + offset, sizeof(frame) - offset, "%s.local", cfg.mdns_name); + if(dns_encode_name((char*) frame + offset, &name)){ + LOGPF("Failed to encode name for %s", frame + offset); + return 1; + } + memcpy(frame + offset, name.name, name.length); + offset += name.length; + + rr = (dns_rr*) (frame + offset); + rr->rtype = htobe16(1); //A RR + rr->rclass = htobe16(1); //INADDR + rr->ttl = htobe32(120); + rr->data = htobe16(4); + offset += sizeof(dns_rr); + + //TODO get local addresses here + frame[offset++] = 0x0A; + frame[offset++] = 0x17; + frame[offset++] = 0x01; + frame[offset++] = 0x07; + + //send to ipv4 and ipv6 mcasts + sendto(cfg.mdns_fd, frame, offset, 0, (struct sockaddr*) &mcast6, sizeof(mcast6)); + sendto(cfg.mdns_fd, frame, offset, 0, (struct sockaddr*) &mcast, sizeof(mcast)); + + free(name.name); + return 0; +} + static int rtpmidi_service(){ size_t n, u, p; instance** inst = NULL; @@ -938,15 +1127,16 @@ static int rtpmidi_service(){ return 1; } - //mdns discovery - if(cfg.mdns_fd >= 0){ - //TODO send applemidi discovery packets - } for(u = 0; u < n; u++){ data = (rtpmidi_instance_data*) inst[u]->impl; if(data->mode == apple){ + //mdns discovery + if(cfg.mdns_fd >= 0){ + rtpmidi_mdns_announce(data); + } + for(p = 0; p < data->peers; p++){ if(data->peer[p].active && data->peer[p].connected){ //apple sync @@ -986,7 +1176,7 @@ static int rtpmidi_handle_mdns(){ .alloc = 0 }; ssize_t bytes = 0; - size_t u = 0, offset = sizeof(dns_header); + size_t u = 0, offset = 0; for(bytes = recv(cfg.mdns_fd, buffer, sizeof(buffer), 0); bytes > 0; bytes = recv(cfg.mdns_fd, buffer, sizeof(buffer), 0)){ if(bytes < sizeof(dns_header)){ @@ -1000,14 +1190,18 @@ static int rtpmidi_handle_mdns(){ hdr->servers = be16toh(hdr->servers); hdr->additional = be16toh(hdr->additional); + //rfc6762 18.3: opcode != 0 -> ignore + //rfc6762 18.11: response code != 0 -> ignore + //TODO Check for ._apple-midi._udp.local. + offset = sizeof(dns_header); LOGPF("ID %d, Opcode %d, %s, %d questions, %d answers, %d servers, %d additional", hdr->id, DNS_OPCODE(hdr->flags[0]), DNS_RESPONSE(hdr->flags[0]) ? "response" : "query", hdr->questions, hdr->answers, hdr->servers, hdr->additional); for(u = 0; u < hdr->questions; u++){ dns_decode_name(buffer, bytes, offset, &name); offset += name.length; offset += sizeof(dns_question); - LOGPF("Question: %s", name.name); + LOGPF("Question (%d bytes): %s", name.length, name.name); } for(u = 0; u < hdr->answers; u++){ @@ -1151,7 +1345,7 @@ static int rtpmidi_start(size_t n, instance** inst){ } //if not bound, bind to default - if(data->fd < 0 && rtpmidi_bind_instance(data, RTPMIDI_DEFAULT_HOST, NULL)){ + if(data->fd < 0 && rtpmidi_bind_instance(inst[u], data, RTPMIDI_DEFAULT_HOST, NULL)){ LOGPF("Failed to bind default sockets for instance %s", inst[u]->name); return 1; } @@ -1178,7 +1372,7 @@ static int rtpmidi_start(size_t n, instance** inst){ if(mdns_required && rtpmidi_start_mdns()){ return 1; } - else{ + else if(mdns_required){ fds++; } diff --git a/backends/rtpmidi.h b/backends/rtpmidi.h index b1fe26a..f55b543 100644 --- a/backends/rtpmidi.h +++ b/backends/rtpmidi.h @@ -22,6 +22,8 @@ static int rtpmidi_shutdown(size_t n, instance** inst); #define RTPMIDI_GET_TYPE(a) ((a) & 0x7F) #define RTPMIDI_DEFAULT_NAME "MIDIMonster" #define RTPMIDI_SERVICE_INTERVAL 1000 +#define RTPMIDI_MDNS_DOMAIN "_apple-midi._udp.local" +#define RTPMIDI_DNSSD_DOMAIN "_services._dns-sd._udp.local" #define DNS_POINTER(a) (((a) & 0xC0) == 0xC0) #define DNS_LABEL_LENGTH(a) ((a) & 0x3F) @@ -67,6 +69,7 @@ typedef struct /*_rtmidi_instance_data*/ { int fd; int control_fd; + uint16_t control_port; /*convenience member set by rtpmidi_bind_instance*/ size_t peers; rtpmidi_peer* peer; @@ -161,4 +164,10 @@ typedef struct /*_dns_rr*/ { uint32_t ttl; uint16_t data; } dns_rr; + +typedef struct /*_dns_rr_srv*/ { + uint16_t priority; + uint16_t weight; + uint16_t port; +} dns_rr_srv; #pragma pack(pop) |