Add support for listening sockets for outgoing data.

adsbus.c

@@ -4,6 +4,7 @@
 #include <getopt.h>
 #include <sys/epoll.h>
 #include <string.h>
+#include <signal.h>
 
 #include "common.h"
 #include "backend.h"
@@ -35,6 +36,7 @@ static void print_usage(char *argv[]) {
 			"\t--backend=HOST/PORT\n"
 			"\t--dump=FORMAT\n"
 			"\t--incoming=[HOST/]PORT\n"
+			"\t--listen=FORMAT=[HOST/]PORT\n"
 			, argv[0]);
 }
 
@@ -43,24 +45,25 @@ static bool parse_opts(int argc, char *argv[], int epoll_fd) {
 		{"backend",  required_argument, 0, 'b'},
 		{"dump",     required_argument, 0, 'd'},
 		{"incoming", required_argument, 0, 'i'},
+		{"listen",   required_argument, 0, 'l'},
 		{"help",     no_argument,       0, 'h'},
 	};
 
 	int opt;
-	char *delim;
+	char *delim1, *delim2;
 	while ((opt = getopt_long_only(argc, argv, "", long_options, NULL)) != -1) {
 		switch (opt) {
 			case 'b':
 				// It would be really nice if libc had a standard way to split host:port.
-				delim = strrchr(optarg, '/');
-				if (delim == NULL) {
+				delim1 = strrchr(optarg, '/');
+				if (delim1 == NULL) {
 					print_usage(argv);
 					return false;
 				}
-				*delim = '\0';
-				delim++;
+				*delim1 = '\0';
+				delim1++;
 
-				backend_new(optarg, delim, epoll_fd);
+				backend_new(optarg, delim1, epoll_fd);
 				break;
 
 		  case 'd':
@@ -74,13 +77,37 @@ static bool parse_opts(int argc, char *argv[], int epoll_fd) {
 				return false;
 
 			case 'i':
-				delim = strrchr(optarg, '/');
-				if (delim == NULL) {
-					incoming_new(NULL, optarg, epoll_fd, backend_new_fd);
+				delim1 = strrchr(optarg, '/');
+				if (delim1 == NULL) {
+					incoming_new(NULL, optarg, epoll_fd, backend_new_fd, NULL);
 				} else {
-					*delim = '\0';
-					delim++;
-					incoming_new(optarg, delim, epoll_fd, backend_new_fd);
+					*delim1 = '\0';
+					delim1++;
+					incoming_new(optarg, delim1, epoll_fd, backend_new_fd, NULL);
+				}
+				break;
+
+			case 'l':
+				delim1 = strchr(optarg, '=');
+				if (delim1 == NULL) {
+					print_usage(argv);
+					return false;
+				}
+				*delim1 = '\0';
+				delim1++;
+				struct serializer *serializer = client_get_serializer(optarg);
+				if (!serializer) {
+					fprintf(stderr, "Unknown format: %s\n", optarg);
+					return false;
+				}
+
+				delim2 = strrchr(delim1, '/');
+				if (delim2 == NULL) {
+					incoming_new(NULL, delim1, epoll_fd, client_new_fd, serializer);
+				} else {
+					*delim2 = '\0';
+					delim2++;
+					incoming_new(delim1, delim2, epoll_fd, client_new_fd, serializer);
 				}
 				break;
 
@@ -117,6 +144,8 @@ static int loop(int epoll_fd) {
 }
 
 int main(int argc, char *argv[]) {
+	signal(SIGPIPE, SIG_IGN);
+
 	server_init();
 	hex_init();
 	airspy_adsb_init();

backend.c

@@ -63,7 +63,7 @@ void backend_new(char *node, char *service, int epoll_fd) {
 	backend_connect(backend, epoll_fd);
 }
 
-void backend_new_fd(int fd, int epoll_fd) {
+void backend_new_fd(int fd, int epoll_fd, void *unused) {
 	struct backend *backend = backend_create();
 	backend->peer.fd = fd;
 	backend->peer.event_handler = backend_read;

backend.h

@@ -22,4 +22,4 @@ struct backend {
 };
 
 void backend_new(char *, char *, int);
-void backend_new_fd(int, int);
+void backend_new_fd(int, int, void *);

client.c

@@ -77,6 +77,11 @@ void client_add(int fd, struct serializer *serializer) {
 	fprintf(stderr, "C %s (%s): New client\n", client->id, serializer->name);
 }
 
+void client_new_fd(int fd, int epoll_fd, void *passthrough) {
+	struct serializer *serializer = (struct serializer *) passthrough;
+	client_add(fd, serializer);
+}
+
 void client_write(struct packet *packet) {
 	for (int i = 0; i < NUM_SERIALIZERS; i++) {
 		struct serializer *serializer = &serializers[i];

client.h

@@ -5,4 +5,5 @@
 
 struct serializer *client_get_serializer(char *);
 void client_add(int, struct serializer *);
+void client_new_fd(int, int, void *);
 void client_write(struct packet *);

incoming.c

@@ -18,6 +18,7 @@ struct incoming {
 	char *node;
 	char *service;
 	incoming_connection_handler handler;
+	void *passthrough;
 };
 
 
@@ -44,16 +45,17 @@ static void incoming_handler(struct peer *peer, int epoll_fd) {
 			local_hbuf, local_sbuf,
 			peer_hbuf, peer_sbuf);
 
-	incoming->handler(fd, epoll_fd);
+	incoming->handler(fd, epoll_fd, incoming->passthrough);
 }
 
-void incoming_new(char *node, char *service, int epoll_fd, incoming_connection_handler handler) {
+void incoming_new(char *node, char *service, int epoll_fd, incoming_connection_handler handler, void *passthrough) {
 	struct incoming *incoming = malloc(sizeof(*incoming));
 	incoming->peer.event_handler = incoming_handler;
 	uuid_gen(incoming->id);
 	incoming->node = node;
 	incoming->service = service;
 	incoming->handler = handler;
+	incoming->passthrough = passthrough;
 
 	fprintf(stderr, "I %s: Resolving %s/%s...\n", incoming->id, incoming->node, incoming->service);
 

incoming.h

@@ -1,4 +1,4 @@
 #pragma once
 
-typedef void (*incoming_connection_handler)(int fd, int epoll_fd);
-void incoming_new(char *, char *, int, incoming_connection_handler);
+typedef void (*incoming_connection_handler)(int fd, int epoll_fd, void *);
+void incoming_new(char *, char *, int, incoming_connection_handler, void *);