diff --git a/adsbus/.gitignore b/adsbus/.gitignore
index 55c3eac..14d0f0c 100644
--- a/adsbus/.gitignore
+++ b/adsbus/.gitignore
@@ -33,3 +33,6 @@
 
 # Binaries
 adsbus
+
+# Generated
+build.h
diff --git a/adsbus/Makefile b/adsbus/Makefile
index fe6dabd..d5549a0 100644
--- a/adsbus/Makefile
+++ b/adsbus/Makefile
@@ -10,20 +10,26 @@ VALGRIND ?= valgrind
 VALGRIND_FLAGS ?= --error-exitcode=1 --trace-children=yes --track-fds=yes --show-leak-kinds=all --leak-check=full
 ADSBUS_TEST_FLAGS ?= --stdin --stdout=airspy_adsb --stdout=beast --stdout=json --stdout=proto --stdout=raw --stdout=stats
 
-OBJ_TRANSPORT = exec.o file.o incoming.o outgoing.o
+OBJ_TRANSPORT = exec.o file.o incoming.o outgoing.o stdinout.o
 OBJ_FLOW = flow.o receive.o send.o send_receive.o
 OBJ_PROTOCOL = airspy_adsb.o beast.o json.o proto.o raw.o stats.o
-OBJ_UTIL = asyncaddrinfo.o buf.o hex.o list.o opts.o packet.o peer.o rand.o resolve.o server.o socket.o uuid.o wakeup.o
+OBJ_UTIL = asyncaddrinfo.o buf.o hex.o list.o log.o opts.o packet.o peer.o rand.o resolve.o server.o socket.o uuid.o wakeup.o
 OBJ_PROTO = adsb.pb-c.o
 
 all: adsbus
 
 clean:
-	rm -rf *.o adsbus testout findings
+	rm -rf *.o adsbus testout findings build.h
 
-%.o: %.c *.h
+%.o: %.c *.h build.h
 	$(COMP) -c $(CFLAGS) $< -o $@
 
+build.h:
+	echo "#define GIT_LAST_CHANGE \"$$(git log --format=%H -n 1)\"" > $@
+	echo "#define GIT_LOCAL_CLEAN $$(git diff --exit-code > /dev/null && echo true || echo false)" >> $@
+	echo "#define HOSTNAME \"$$(hostname --fqdn)\"" >> $@
+	echo "#define USERNAME \"$$(whoami)\"" >> $@
+
 adsb.pb-c.c: ../proto/adsb.proto
 	protoc-c --c_out=./ --proto_path=$(dir $<) $<
 
diff --git a/adsbus/adsbus.c b/adsbus/adsbus.c
index 5621eb3..c1bdded 100644
--- a/adsbus/adsbus.c
+++ b/adsbus/adsbus.c
@@ -1,9 +1,6 @@
 #include <assert.h>
 #include <fcntl.h>
-#include <getopt.h>
-#include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ -14,6 +11,7 @@
 #include "hex.h"
 #include "incoming.h"
 #include "json.h"
+#include "log.h"
 #include "opts.h"
 #include "outgoing.h"
 #include "peer.h"
@@ -25,164 +23,43 @@
 #include "send_receive.h"
 #include "server.h"
 #include "stats.h"
+#include "stdinout.h"
 #include "wakeup.h"
 
-static void print_usage(const char *name) {
-	fprintf(stderr,
-			"\n"
-			"Usage: %s [OPTION]...\n"
-			"\n"
-			"Options:\n"
-			"\t--help\n"
-			"\t--connect-receive=HOST/PORT\n"
-			"\t--connect-send=FORMAT=HOST/PORT\n"
-			"\t--connect-send-receive=FORMAT=HOST/PORT\n"
-			"\t--listen-receive=[HOST/]PORT\n"
-			"\t--listen-send=FORMAT=[HOST/]PORT\n"
-			"\t--listen-send-receive=FORMAT=[HOST/]PORT\n"
-			"\t--file-read=PATH\n"
-			"\t--file-write=FORMAT=PATH\n"
-			"\t--file-write-read=FORMAT=PATH\n"
-			"\t--file-append=FORMAT=PATH\n"
-			"\t--file-append-read=FORMAT=PATH\n"
-			"\t--exec-receive=COMMAND\n"
-			"\t--exec-send=FORMAT=COMMAND\n"
-			"\t--exec-send-receive=FORMAT=COMMAND\n"
-			"\t--stdin\n"
-			"\t--stdout=FORMAT\n"
-			, name);
-	receive_print_usage();
-	send_print_usage();
-}
-
-static bool parse_opts(int argc, char *argv[]) {
-	static struct option long_options[] = {
-		{"connect-receive",      required_argument, 0, 'c'},
-		{"connect-send",         required_argument, 0, 's'},
-		{"connect-send-receive", required_argument, 0, 't'},
-		{"listen-receive",       required_argument, 0, 'l'},
-		{"listen-send",          required_argument, 0, 'm'},
-		{"listen-send-receive",  required_argument, 0, 'n'},
-		{"file-read",            required_argument, 0, 'r'},
-		{"file-write",           required_argument, 0, 'w'},
-		{"file-write-read",      required_argument, 0, 'x'},
-		{"file-append",          required_argument, 0, 'a'},
-		{"file-append-read",     required_argument, 0, 'b'},
-		{"exec-receive",         required_argument, 0, 'e'},
-		{"exec-send",            required_argument, 0, 'f'},
-		{"exec-send-receive",    required_argument, 0, 'g'},
-		{"stdin",                no_argument,       0, 'i'},
-		{"stdout",               required_argument, 0, 'o'},
-		{"help",                 no_argument,       0, 'h'},
-		{0,                      0,                 0, 0  },
-	};
-
-	int opt;
-	while ((opt = getopt_long_only(argc, argv, "", long_options, NULL)) != -1) {
-		bool (*handler)(char *) = NULL;
-		switch (opt) {
-			case 'c':
-				handler = opts_add_connect_receive;
-				break;
-
-			case 's':
-				handler = opts_add_connect_send;
-				break;
-
-			case 't':
-				handler = opts_add_connect_send_receive;
-				break;
-
-			case 'l':
-				handler = opts_add_listen_receive;
-				break;
-
-			case 'm':
-				handler = opts_add_listen_send;
-				break;
-
-			case 'n':
-				handler = opts_add_listen_send_receive;
-				break;
-
-			case 'r':
-				handler = opts_add_file_read;
-				break;
-
-			case 'w':
-				handler = opts_add_file_write;
-				break;
-
-			case 'x':
-				handler = opts_add_file_write_read;
-				break;
-
-			case 'a':
-				handler = opts_add_file_append;
-				break;
-
-			case 'b':
-				handler = opts_add_file_append_read;
-				break;
-
-			case 'e':
-				handler = opts_add_exec_receive;
-				break;
-
-			case 'f':
-				handler = opts_add_exec_send;
-				break;
-
-			case 'g':
-				handler = opts_add_exec_send_receive;
-				break;
-
-		  case 'i':
-				handler = opts_add_stdin;
-				break;
-
-		  case 'o':
-				handler = opts_add_stdout;
-				break;
-
-			case 'h':
-			default:
-				print_usage(argv[0]);
-				return false;
-		}
-
-		if (handler) {
-			if (!handler(optarg)) {
-				fprintf(stderr, "Invalid flag value: %s\n", optarg);
-				print_usage(argv[0]);
-				return false;
-			}
-		}
-	}
-
-	if (optind != argc) {
-		fprintf(stderr, "Not a flag: %s\n", argv[optind]);
-		print_usage(argv[0]);
-		return false;
-	}
-
-	return true;
-}
-
 static void reopen(int fd, char *path, int flags) {
 	// Presumes that all fds < fd are open
 	assert(!close(fd));
-	assert(open(path, flags | O_CLOEXEC) == fd);
+	assert(open(path, flags | O_CLOEXEC | O_NOCTTY) == fd);
+}
+
+static void adsbus_opts_add() {
+	// This order controls the order in --help, but nothing else.
+	server_opts_add();
+	log_opts_add();
+	outgoing_opts_add();
+	incoming_opts_add();
+	exec_opts_add();
+	file_opts_add();
+	stdinout_opts_add();
 }
 
 int main(int argc, char *argv[]) {
+	adsbus_opts_add();
+
+	opts_init(argc, argv);
+
 	hex_init();
 	rand_init();
-	resolve_init();
+
+	log_init();
 	server_init();
+
+	resolve_init();
 	wakeup_init();
 	peer_init();
 
+	log_init_peer();
+
 	receive_init();
 	send_init();
 
@@ -191,9 +68,11 @@ int main(int argc, char *argv[]) {
 	proto_init();
 	stats_init();
 
-	if (!parse_opts(argc, argv)) {
-		peer_shutdown(0);
-	}
+	outgoing_init();
+	incoming_init();
+	exec_init();
+	file_init();
+	stdinout_init();
 
 	reopen(STDIN_FILENO, "/dev/null", O_RDONLY);
 	reopen(STDOUT_FILENO, "/dev/full", O_WRONLY);
@@ -216,11 +95,14 @@ int main(int argc, char *argv[]) {
 	rand_cleanup();
 	wakeup_cleanup();
 
+	log_cleanup_peer();
+
 	peer_cleanup();
 
+	log_cleanup();
+
 	assert(!close(STDIN_FILENO));
 	assert(!close(STDOUT_FILENO));
-	assert(!close(STDERR_FILENO));
 
 	return EXIT_SUCCESS;
 }
diff --git a/adsbus/airspy_adsb.c b/adsbus/airspy_adsb.c
index eeac285..876bbc1 100644
--- a/adsbus/airspy_adsb.c
+++ b/adsbus/airspy_adsb.c
@@ -1,12 +1,9 @@
 #include <assert.h>
-#include <stdio.h>
-#include <string.h>
 
 #include "buf.h"
 #include "hex.h"
 #include "packet.h"
 #include "receive.h"
-#include "uuid.h"
 
 #include "airspy_adsb.h"
 
diff --git a/adsbus/asyncaddrinfo.c b/adsbus/asyncaddrinfo.c
index c2578c4..6e2411a 100644
--- a/adsbus/asyncaddrinfo.c
+++ b/adsbus/asyncaddrinfo.c
@@ -2,10 +2,12 @@
 #include <fcntl.h>
 #include <netdb.h>
 #include <pthread.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 #include "asyncaddrinfo.h"
@@ -27,6 +29,11 @@ static int asyncaddrinfo_write_fd;
 
 static void *asyncaddrinfo_main(void *arg) {
 	int fd = (int) (intptr_t) arg;
+
+	sigset_t sigmask;
+	assert(!sigfillset(&sigmask));
+	assert(!pthread_sigmask(SIG_BLOCK, &sigmask, NULL));
+
 	struct asyncaddrinfo_resolution *res;
 	ssize_t len;
 	while ((len = recv(fd, &res, sizeof(res), 0)) == sizeof(res)) {
diff --git a/adsbus/beast.c b/adsbus/beast.c
index b808210..31c2846 100644
--- a/adsbus/beast.c
+++ b/adsbus/beast.c
@@ -1,7 +1,5 @@
 #include <assert.h>
-#include <stdio.h>
 #include <string.h>
-#include <stdint.h>
 
 #include "buf.h"
 #include "packet.h"
diff --git a/adsbus/exec.c b/adsbus/exec.c
index e072c74..f5826ed 100644
--- a/adsbus/exec.c
+++ b/adsbus/exec.c
@@ -1,17 +1,20 @@
 #include <assert.h>
 #include <signal.h>
 #include <stdlib.h>
-#include <stdio.h>
 #include <string.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
-#include "buf.h"
 #include "flow.h"
-#include "list.h"
+#include "log.h"
+#include "opts.h"
 #include "peer.h"
+#include "receive.h"
+#include "send.h"
+#include "send_receive.h"
 #include "uuid.h"
 #include "wakeup.h"
 
@@ -19,6 +22,7 @@
 
 struct exec {
 	struct peer peer;
+	struct peer log_peer;
 	uint8_t id[UUID_LEN];
 	char *command;
 	struct flow *flow;
@@ -28,89 +32,164 @@ struct exec {
 };
 
 static struct list_head exec_head = LIST_HEAD_INIT(exec_head);
+static opts_group exec_opts;
+
+static char log_module = 'E';
 
 static void exec_spawn_wrapper(struct peer *);
 
+static void exec_harvest(struct exec *exec) {
+	if (exec->child > 0) {
+		int status;
+		assert(waitpid(exec->child, &status, 0) == exec->child);
+		exec->child = -1;
+		if (WIFEXITED(status)) {
+			LOG(exec->id, "Client exited with status %d", WEXITSTATUS(status));
+		} else {
+			assert(WIFSIGNALED(status));
+			LOG(exec->id, "Client exited with signal %d", WTERMSIG(status));
+		}
+	}
+	peer_close(&exec->log_peer);
+}
+
 static void exec_del(struct exec *exec) {
 	flow_ref_dec(exec->flow);
 
 	if (exec->child > 0) {
-		fprintf(stderr, "E %s: Sending SIGTERM to child process %d\n", exec->id, exec->child);
+		LOG(exec->id, "Sending SIGTERM to child process %d", exec->child);
 		// Racy with the process terminating, so don't assert on it
 		kill(exec->child, SIGTERM);
-		assert(waitpid(exec->child, NULL, 0) == exec->child);
 	}
+	exec_harvest(exec);
 	list_del(&exec->exec_list);
 	free(exec->command);
 	free(exec);
 }
 
 static void exec_close_handler(struct peer *peer) {
-	struct exec *exec = (struct exec *) peer;
-	int status;
-	assert(waitpid(exec->child, &status, WNOHANG) == exec->child);
-	exec->child = -1;
-	if (WIFEXITED(status)) {
-		fprintf(stderr, "E %s: Client exited with status %d\n", exec->id, WEXITSTATUS(status));
-	} else {
-		assert(WIFSIGNALED(status));
-		fprintf(stderr, "E %s: Client exited with signal %d\n", exec->id, WTERMSIG(status));
-	}
+	struct exec *exec = container_of(peer, struct exec, peer);
+	exec_harvest(exec);
 	uint32_t delay = wakeup_get_retry_delay_ms(1);
-	fprintf(stderr, "E %s: Will retry in %ds\n", exec->id, delay / 1000);
+	LOG(exec->id, "Will retry in %ds", delay / 1000);
 	exec->peer.event_handler = exec_spawn_wrapper;
-	wakeup_add((struct peer *) exec, delay);
+	wakeup_add(&exec->peer, delay);
 }
 
-static void exec_parent(struct exec *exec, pid_t child, int fd) {
+static void exec_log_handler(struct peer *peer) {
+	// Do you believe in magic?
+	struct exec *exec = container_of(peer, struct exec, log_peer);
+
+	char linebuf[4096];
+	ssize_t ret = read(exec->log_peer.fd, linebuf, 4096);
+	if (ret <= 0) {
+		LOG(exec->id, "Log input stream closed");
+		peer_close(&exec->log_peer);
+		return;
+	}
+	size_t len = (size_t) ret;
+	char *iter = linebuf, *eol;
+	while ((eol = memchr(iter, '\n', len))) {
+		assert(eol >= iter);
+		size_t linelen = (size_t) (eol - iter);
+		LOG(exec->id, "(child output) %.*s", (int) linelen, iter);
+		iter += (linelen + 1);
+		len -= (linelen + 1);
+	}
+	if (len) {
+		LOG(exec->id, "(child output) %.*s", (int) len, iter);
+	}
+}
+
+static void exec_parent(struct exec *exec, pid_t child, int data_fd, int log_fd) {
 	exec->child = child;
-	fprintf(stderr, "E %s: Child started as process %d\n", exec->id, exec->child);
+	LOG(exec->id, "Child started as process %d", exec->child);
+
+	exec->log_peer.fd = log_fd;
+	exec->log_peer.event_handler = exec_log_handler;
+	peer_epoll_add(&exec->log_peer, EPOLLIN);
 
 	exec->peer.event_handler = exec_close_handler;
-	if (!flow_new_send_hello(fd, exec->flow, exec->passthrough, (struct peer *) exec)) {
-		exec_close_handler((struct peer *) exec);
+	if (!flow_new_send_hello(data_fd, exec->flow, exec->passthrough, &exec->peer)) {
+		exec_close_handler(&exec->peer);
 		return;
 	}
 }
 
-static void __attribute__ ((noreturn)) exec_child(const struct exec *exec, int fd) {
+static void __attribute__ ((noreturn)) exec_child(const struct exec *exec, int data_fd, int log_fd) {
 	assert(setsid() != -1);
 	// We leave stderr open from child to parent
 	// Other than that, fds should have CLOEXEC set
-	if (fd != 0) {
-		assert(dup2(fd, 0) == 0);
+	if (data_fd != STDIN_FILENO) {
+		assert(dup2(data_fd, STDIN_FILENO) == STDIN_FILENO);
 	}
-	if (fd != 1) {
-		assert(dup2(fd, 1) == 1);
+	if (data_fd != STDOUT_FILENO) {
+		assert(dup2(data_fd, STDOUT_FILENO) == STDOUT_FILENO);
 	}
-	if (fd != 0 && fd != 1) {
-		assert(!close(fd));
+	if (data_fd != STDIN_FILENO && data_fd != STDOUT_FILENO) {
+		assert(!close(data_fd));
+	}
+	if (log_fd != STDERR_FILENO) {
+		assert(dup2(log_fd, STDERR_FILENO) == STDERR_FILENO);
+		assert(!close(log_fd));
 	}
 	assert(!execl("/bin/sh", "sh", "-c", exec->command, NULL));
 	abort();
 }
 
 static void exec_spawn(struct exec *exec) {
-	fprintf(stderr, "E %s: Executing: %s\n", exec->id, exec->command);
-	int fds[2];
-	assert(!socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0, fds));
+	LOG(exec->id, "Executing: %s", exec->command);
+	int data_fds[2], log_fds[2];
+	// Leave these sockets blocking; we move in lock step with subprograms
+	assert(!socketpair(AF_UNIX, SOCK_STREAM, 0, data_fds));
+	assert(!socketpair(AF_UNIX, SOCK_STREAM, 0, log_fds));
 	
 	int res = fork();
 	assert(res >= 0);
 	if (res) {
-		assert(!close(fds[1]));
-		exec_parent(exec, res, fds[0]);
+		assert(!close(data_fds[1]));
+		assert(!close(log_fds[1]));
+		assert(!shutdown(log_fds[0], SHUT_WR));
+		exec_parent(exec, res, data_fds[0], log_fds[0]);
 	} else {
-		assert(!close(fds[0]));
-		exec_child(exec, fds[1]);
+		assert(!close(data_fds[0]));
+		assert(!close(log_fds[0]));
+		exec_child(exec, data_fds[1], log_fds[1]);
 	}
 }
 
 static void exec_spawn_wrapper(struct peer *peer) {
-	struct exec *exec = (struct exec *) peer;
+	struct exec *exec = container_of(peer, struct exec, peer);
 	exec_spawn(exec);
 }
 
+static bool exec_add(const char *cmd, struct flow *flow, void *passthrough) {
+	exec_new(cmd, flow, passthrough);
+	return true;
+}
+
+static bool exec_receive(const char *arg) {
+	return exec_add(arg, receive_flow, NULL);
+}
+
+static bool exec_send(const char *arg) {
+	return send_add(exec_add, send_flow, arg);
+}
+
+static bool exec_send_receive(const char *arg) {
+	return send_add(exec_add, send_receive_flow, arg);
+}
+
+void exec_opts_add() {
+	opts_add("exec-receive", "COMMAND", exec_receive, exec_opts);
+	opts_add("exec-send", "FORMAT=COMMAND", exec_send, exec_opts);
+	opts_add("exec-send-receive", "FORMAT=COMMAND", exec_send_receive, exec_opts);
+}
+
+void exec_init() {
+	opts_call(exec_opts);
+}
+
 void exec_cleanup() {
 	struct exec *iter, *next;
 	list_for_each_entry_safe(iter, next, &exec_head, exec_list) {
@@ -118,7 +197,7 @@ void exec_cleanup() {
 	}
 }
 
-void exec_new(char *command, struct flow *flow, void *passthrough) {
+void exec_new(const char *command, struct flow *flow, void *passthrough) {
 	flow_ref_inc(flow);
 
 	struct exec *exec = malloc(sizeof(*exec));
diff --git a/adsbus/exec.h b/adsbus/exec.h
index 0c8c525..adb0c79 100644
--- a/adsbus/exec.h
+++ b/adsbus/exec.h
@@ -2,5 +2,7 @@
 
 struct flow;
 
+void exec_opts_add(void);
+void exec_init(void);
 void exec_cleanup(void);
-void exec_new(char *, struct flow *, void *);
+void exec_new(const char *, struct flow *, void *);
diff --git a/adsbus/file.c b/adsbus/file.c
index 2d09009..89f1782 100644
--- a/adsbus/file.c
+++ b/adsbus/file.c
@@ -2,18 +2,18 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
-#include <stdio.h>
 #include <string.h>
-#include <sys/epoll.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include "flow.h"
-#include "list.h"
+#include "log.h"
+#include "opts.h"
 #include "peer.h"
 #include "receive.h"
 #include "send.h"
+#include "send_receive.h"
 #include "uuid.h"
 #include "wakeup.h"
 
@@ -32,6 +32,9 @@ struct file {
 };
 
 static struct list_head file_head = LIST_HEAD_INIT(file_head);
+static opts_group file_opts;
+
+static char log_module = 'F';
 
 static void file_open_wrapper(struct peer *);
 
@@ -67,14 +70,14 @@ static void file_del(struct file *file) {
 
 static void file_retry(struct file *file) {
 	uint32_t delay = wakeup_get_retry_delay_ms(file->attempt++);
-	fprintf(stderr, "F %s: Will retry in %ds\n", file->id, delay / 1000);
+	LOG(file->id, "Will retry in %ds", delay / 1000);
 	file->peer.event_handler = file_open_wrapper;
-	wakeup_add((struct peer *) file, delay);
+	wakeup_add(&file->peer, delay);
 }
 
 static void file_handle_close(struct peer *peer) {
-	struct file *file = (struct file *) peer;
-	fprintf(stderr, "F %s: File closed: %s\n", file->id, file->path);
+	struct file *file = container_of(peer, struct file, peer);
+	LOG(file->id, "File closed: %s", file->path);
 
 	if (file->retry) {
 		file_retry(file);
@@ -84,10 +87,10 @@ static void file_handle_close(struct peer *peer) {
 }
 
 static void file_open(struct file *file) {
-	fprintf(stderr, "F %s: Opening file: %s\n", file->id, file->path);
-	int fd = open(file->path, file->flags | O_CLOEXEC, S_IRUSR | S_IWUSR);
+	LOG(file->id, "Opening file: %s", file->path);
+	int fd = open(file->path, file->flags | O_CLOEXEC | O_NOCTTY, S_IRUSR | S_IWUSR);
 	if (fd == -1) {
-		fprintf(stderr, "F %s: Error opening file: %s\n", file->id, strerror(errno));
+		LOG(file->id, "Error opening file: %s", strerror(errno));
 		file_retry(file);
 		return;
 	}
@@ -95,19 +98,19 @@ static void file_open(struct file *file) {
 	file->retry = file_should_retry(fd, file);
 	file->peer.event_handler = file_handle_close;
 	file->attempt = 0;
-	if (!flow_new_send_hello(fd, file->flow, file->passthrough, (struct peer *) file)) {
-		fprintf(stderr, "F %s: Error writing greeting\n", file->id);
+	if (!flow_new_send_hello(fd, file->flow, file->passthrough, &file->peer)) {
+		LOG(file->id, "Error writing greeting");
 		file_retry(file);
 		return;
 	}
 }
 
 static void file_open_wrapper(struct peer *peer) {
-	struct file *file = (struct file *) peer;
+	struct file *file = container_of(peer, struct file, peer);
 	file_open(file);
 }
 
-static void file_new(char *path, int flags, struct flow *flow, void *passthrough) {
+static void file_new(const char *path, int flags, struct flow *flow, void *passthrough) {
 	flow_ref_inc(flow);
 
 	struct file *file = malloc(sizeof(*file));
@@ -126,6 +129,49 @@ static void file_new(char *path, int flags, struct flow *flow, void *passthrough
 	file_open(file);
 }
 
+static bool file_write_add(const char *path, struct flow *flow, void *passthrough) {
+	file_write_new(path, flow, passthrough);
+	return true;
+}
+
+static bool file_append_add(const char *path, struct flow *flow, void *passthrough) {
+	file_append_new(path, flow, passthrough);
+	return true;
+}
+
+static bool file_read(const char *arg) {
+	file_read_new(arg, receive_flow, NULL);
+	return true;
+}
+
+static bool file_write(const char *arg) {
+	return send_add(file_write_add, send_flow, arg);
+}
+
+static bool file_write_read(const char *arg) {
+	return send_add(file_write_add, send_receive_flow, arg);
+}
+
+static bool file_append(const char *arg) {
+	return send_add(file_append_add, send_flow, arg);
+}
+
+static bool file_append_read(const char *arg) {
+	return send_add(file_append_add, send_receive_flow, arg);
+}
+
+void file_opts_add() {
+	opts_add("file-read", "PATH", file_read, file_opts);
+	opts_add("file-write", "FORMAT=PATH", file_write, file_opts);
+	opts_add("file-write-read", "FORMAT=PATH", file_write_read, file_opts);
+	opts_add("file-append", "FORMAT=PATH", file_append, file_opts);
+	opts_add("file-append-read", "FORMAT=PATH", file_append_read, file_opts);
+}
+
+void file_init() {
+	opts_call(file_opts);
+}
+
 void file_cleanup() {
 	struct file *iter, *next;
 	list_for_each_entry_safe(iter, next, &file_head, file_list) {
@@ -133,14 +179,14 @@ void file_cleanup() {
 	}
 }
 
-void file_read_new(char *path, struct flow *flow, void *passthrough) {
+void file_read_new(const char *path, struct flow *flow, void *passthrough) {
 	file_new(path, O_RDONLY, flow, passthrough);
 }
 
-void file_write_new(char *path, struct flow *flow, void *passthrough) {
+void file_write_new(const char *path, struct flow *flow, void *passthrough) {
 	file_new(path, O_WRONLY | O_CREAT | O_NOFOLLOW | O_TRUNC, flow, passthrough);
 }
 
-void file_append_new(char *path, struct flow *flow, void *passthrough) {
+void file_append_new(const char *path, struct flow *flow, void *passthrough) {
 	file_new(path, O_WRONLY | O_CREAT | O_NOFOLLOW, flow, passthrough);
 }
diff --git a/adsbus/file.h b/adsbus/file.h
index 7727a49..659b626 100644
--- a/adsbus/file.h
+++ b/adsbus/file.h
@@ -2,7 +2,9 @@
 
 struct flow;
 
+void file_opts_add(void);
+void file_init(void);
 void file_cleanup(void);
-void file_read_new(char *, struct flow *, void *);
-void file_write_new(char *, struct flow *, void *);
-void file_append_new(char *, struct flow *, void *);
+void file_read_new(const char *, struct flow *, void *);
+void file_write_new(const char *, struct flow *, void *);
+void file_append_new(const char *, struct flow *, void *);
diff --git a/adsbus/incoming.c b/adsbus/incoming.c
index daced14..60e8cf5 100644
--- a/adsbus/incoming.c
+++ b/adsbus/incoming.c
@@ -1,18 +1,21 @@
 #include <assert.h>
-#include <stdio.h>
+#include <errno.h>
+#include <netdb.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/types.h>
 #include <sys/socket.h>
-#include <netdb.h>
-#include <string.h>
-#include <errno.h>
+#include <sys/stat.h>
 #include <unistd.h>
 
-#include "buf.h"
 #include "flow.h"
-#include "list.h"
+#include "log.h"
+#include "opts.h"
 #include "peer.h"
+#include "receive.h"
 #include "resolve.h"
+#include "send.h"
+#include "send_receive.h"
 #include "socket.h"
 #include "wakeup.h"
 #include "uuid.h"
@@ -31,25 +34,28 @@ struct incoming {
 };
 
 static struct list_head incoming_head = LIST_HEAD_INIT(incoming_head);
+static opts_group incoming_opts;
+
+static char log_module = 'I';
 
 static void incoming_resolve_wrapper(struct peer *);
 
 static void incoming_retry(struct incoming *incoming) {
 	uint32_t delay = wakeup_get_retry_delay_ms(incoming->attempt++);
-	fprintf(stderr, "I %s: Will retry in %ds\n", incoming->id, delay / 1000);
+	LOG(incoming->id, "Will retry in %ds", delay / 1000);
 	incoming->peer.event_handler = incoming_resolve_wrapper;
-	wakeup_add((struct peer *) incoming, delay);
+	wakeup_add(&incoming->peer, delay);
 }
 
 static void incoming_handler(struct peer *peer) {
-	struct incoming *incoming = (struct incoming *) peer;
+	struct incoming *incoming = container_of(peer, struct incoming, peer);
 
 	struct sockaddr peer_addr, local_addr;
 	socklen_t peer_addrlen = sizeof(peer_addr), local_addrlen = sizeof(local_addr);
 
 	int fd = accept4(incoming->peer.fd, &peer_addr, &peer_addrlen, SOCK_NONBLOCK | SOCK_CLOEXEC);
 	if (fd == -1) {
-		fprintf(stderr, "I %s: Failed to accept new connection on %s/%s: %s\n", incoming->id, incoming->node, incoming->service, strerror(errno));
+		LOG(incoming->id, "Failed to accept new connection on %s/%s: %s", incoming->node, incoming->service, strerror(errno));
 		return;
 	}
 
@@ -58,8 +64,7 @@ static void incoming_handler(struct peer *peer) {
 	assert(getnameinfo(&peer_addr, peer_addrlen, peer_hbuf, sizeof(peer_hbuf), peer_sbuf, sizeof(peer_sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0);
 	assert(getnameinfo(&local_addr, local_addrlen, local_hbuf, sizeof(local_hbuf), local_sbuf, sizeof(local_sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0);
 
-	fprintf(stderr, "I %s: New incoming connection on %s/%s (%s/%s) from %s/%s\n",
-			incoming->id,
+	LOG(incoming->id, "New incoming connection on %s/%s (%s/%s) from %s/%s",
 			incoming->node, incoming->service,
 			local_hbuf, local_sbuf,
 			peer_hbuf, peer_sbuf);
@@ -67,16 +72,14 @@ static void incoming_handler(struct peer *peer) {
 	flow_socket_connected(fd, incoming->flow);
 
 	if (!flow_new_send_hello(fd, incoming->flow, incoming->passthrough, NULL)) {
-		fprintf(stderr, "I %s: Error writing greeting\n", incoming->id);
+		LOG(incoming->id, "Error writing greeting");
 		return;
 	}
 }
 
 static void incoming_del(struct incoming *incoming) {
 	flow_ref_dec(incoming->flow);
-	if (incoming->peer.fd >= 0) {
-		assert(!close(incoming->peer.fd));
-	}
+	peer_close(&incoming->peer);
 	list_del(&incoming->incoming_list);
 	free(incoming->node);
 	free(incoming->service);
@@ -84,12 +87,12 @@ static void incoming_del(struct incoming *incoming) {
 }
 
 static void incoming_listen(struct peer *peer) {
-	struct incoming *incoming = (struct incoming *) peer;
+	struct incoming *incoming = container_of(peer, struct incoming, peer);
 
 	struct addrinfo *addrs;
 	int err = resolve_result(peer, &addrs);
 	if (err) {
-		fprintf(stderr, "I %s: Failed to resolve %s/%s: %s\n", incoming->id, incoming->node, incoming->service, gai_strerror(err));
+		LOG(incoming->id, "Failed to resolve %s/%s: %s", incoming->node, incoming->service, gai_strerror(err));
 		incoming_retry(incoming);
 		return;
 	}
@@ -98,7 +101,7 @@ static void incoming_listen(struct peer *peer) {
 	for (addr = addrs; addr; addr = addr->ai_next) {
 		char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
 		assert(getnameinfo(addr->ai_addr, addr->ai_addrlen, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0);
-		fprintf(stderr, "I %s: Listening on %s/%s...\n", incoming->id, hbuf, sbuf);
+		LOG(incoming->id, "Listening on %s/%s...", hbuf, sbuf);
 
 		incoming->peer.fd = socket(addr->ai_family, addr->ai_socktype | SOCK_CLOEXEC, addr->ai_protocol);
 		assert(incoming->peer.fd >= 0);
@@ -106,7 +109,7 @@ static void incoming_listen(struct peer *peer) {
 		socket_pre_bind(incoming->peer.fd);
 
 		if (bind(incoming->peer.fd, addr->ai_addr, addr->ai_addrlen) != 0) {
-			fprintf(stderr, "I %s: Failed to bind to %s/%s: %s\n", incoming->id, hbuf, sbuf, strerror(errno));
+			LOG(incoming->id, "Failed to bind to %s/%s: %s", hbuf, sbuf, strerror(errno));
 			assert(!close(incoming->peer.fd));
 			continue;
 		}
@@ -122,24 +125,57 @@ static void incoming_listen(struct peer *peer) {
 	freeaddrinfo(addrs);
 
 	if (addr == NULL) {
-		fprintf(stderr, "I %s: Failed to bind any addresses for %s/%s...\n", incoming->id, incoming->node, incoming->service);
+		LOG(incoming->id, "Failed to bind any addresses for %s/%s...", incoming->node, incoming->service);
 		incoming_retry(incoming);
 		return;
 	}
 
 	incoming->attempt = 0;
 	incoming->peer.event_handler = incoming_handler;
-	peer_epoll_add((struct peer *) incoming, EPOLLIN);
+	peer_epoll_add(&incoming->peer, EPOLLIN);
 }
 
 static void incoming_resolve(struct incoming *incoming) {
-	fprintf(stderr, "I %s: Resolving %s/%s...\n", incoming->id, incoming->node, incoming->service);
+	LOG(incoming->id, "Resolving %s/%s...", incoming->node, incoming->service);
 	incoming->peer.event_handler = incoming_listen;
-	resolve((struct peer *) incoming, incoming->node, incoming->service, AI_PASSIVE);
+	resolve(&incoming->peer, incoming->node, incoming->service, AI_PASSIVE);
 }
 
 static void incoming_resolve_wrapper(struct peer *peer) {
-	incoming_resolve((struct incoming *) peer);
+	incoming_resolve(container_of(peer, struct incoming, peer));
+}
+
+static bool incoming_add(const char *host_port, struct flow *flow, void *passthrough) {
+	char *host = opts_split(&host_port, '/');
+	if (host) {
+		incoming_new(host, host_port, flow, passthrough);
+		free(host);
+	} else {
+		incoming_new(NULL, host_port, flow, passthrough);
+	}
+	return true;
+}
+
+static bool incoming_listen_receive(const char *arg) {
+	return incoming_add(arg, receive_flow, NULL);
+}
+
+static bool incoming_listen_send(const char *arg) {
+	return send_add(incoming_add, send_flow, arg);
+}
+
+static bool incoming_listen_send_receive(const char *arg) {
+	return send_add(incoming_add, send_receive_flow, arg);
+}
+
+void incoming_opts_add() {
+	opts_add("listen-receive", "[HOST/]PORT", incoming_listen_receive, incoming_opts);
+	opts_add("listen-send", "FORMAT=[HOST/]PORT", incoming_listen_send, incoming_opts);
+	opts_add("listen-send-receive", "FORMAT=[HOST/]PORT", incoming_listen_send_receive, incoming_opts);
+}
+
+void incoming_init() {
+	opts_call(incoming_opts);
 }
 
 void incoming_cleanup() {
@@ -149,7 +185,7 @@ void incoming_cleanup() {
 	}
 }
 
-void incoming_new(char *node, char *service, struct flow *flow, void *passthrough) {
+void incoming_new(const char *node, const char *service, struct flow *flow, void *passthrough) {
 	flow_ref_inc(flow);
 
 	struct incoming *incoming = malloc(sizeof(*incoming));
diff --git a/adsbus/incoming.h b/adsbus/incoming.h
index 4691c1d..785a164 100644
--- a/adsbus/incoming.h
+++ b/adsbus/incoming.h
@@ -2,5 +2,7 @@
 
 struct flow;
 
+void incoming_opts_add(void);
+void incoming_init(void);
 void incoming_cleanup(void);
-void incoming_new(char *, char *, struct flow *, void *);
+void incoming_new(const char *, const char *, struct flow *, void *);
diff --git a/adsbus/json.c b/adsbus/json.c
index 98a0836..bc6f7de 100644
--- a/adsbus/json.c
+++ b/adsbus/json.c
@@ -1,16 +1,15 @@
 #include <assert.h>
-#include <stdio.h>
+#include <stdbool.h>
 #include <string.h>
 #include <jansson.h>
 
 #include "hex.h"
 #include "buf.h"
+#include "log.h"
 #include "packet.h"
 #include "rand.h"
 #include "receive.h"
-#include "send.h"
 #include "server.h"
-#include "uuid.h"
 
 #include "json.h"
 
@@ -27,6 +26,8 @@ struct json_parser_state {
 static json_t *json_prev = NULL;
 static struct buf json_hello_buf = BUF_INIT;
 
+static char log_module = 'R'; // borrowing
+
 static void json_serialize_to_buf(json_t *obj, struct buf *buf) {
 	assert(json_dump_callback(obj, json_buf_append_callback, buf, 0) == 0);
 	json_decref(obj);
@@ -80,11 +81,11 @@ static bool json_parse_header(json_t *in, struct packet *packet, struct json_par
 	}
 
 	if (!strcmp(json_server_id, (const char *) server_id)) {
-		fprintf(stderr, "R %s: Attempt to receive json data from our own server ID (%s); loop!\n", packet->source_id, server_id);
+		LOG(packet->source_id, "Attempt to receive json data from our own server ID (%s); loop!", server_id);
 		return false;
 	}
 
-	fprintf(stderr, "R %s: Connected to server ID: %s\n", packet->source_id, json_server_id);
+	LOG(packet->source_id, "Connected to server ID: %s", json_server_id);
 
 	state->mlat_timestamp_mhz = (uint16_t) mlat_timestamp_mhz;
 	state->mlat_timestamp_max = (uint64_t) mlat_timestamp_max;
diff --git a/adsbus/list.c b/adsbus/list.c
index f8c2873..e37101b 100644
--- a/adsbus/list.c
+++ b/adsbus/list.c
@@ -1,5 +1,3 @@
-#include <stdlib.h>
-
 #include "list.h"
 
 void list_head_init(struct list_head *head) {
diff --git a/adsbus/list.h b/adsbus/list.h
index fb9af51..c4f4433 100644
--- a/adsbus/list.h
+++ b/adsbus/list.h
@@ -1,16 +1,15 @@
 #pragma once
 
 #include <stdbool.h>
+#include <stddef.h>
 
 #pragma GCC diagnostic ignored "-Wcast-align"
 #pragma GCC diagnostic ignored "-Wgnu-statement-expression"
 #pragma GCC diagnostic ignored "-Wlanguage-extension-token"
 
-#define offset_of(type, member) ((size_t) &((type *) NULL)->member)
-
 #define container_of(ptr, type, member) ({ \
 		typeof( ((type *) NULL)->member ) *__mptr = (ptr); \
-		(type *)( (char *)__mptr - offset_of(type, member) );})
+		(type *)( (char *)__mptr - offsetof(type, member) );})
 
 struct list_head {
 	struct list_head *next;
diff --git a/adsbus/log.c b/adsbus/log.c
new file mode 100644
index 0000000..9fabea2
--- /dev/null
+++ b/adsbus/log.c
@@ -0,0 +1,148 @@
+#include <assert.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/signalfd.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "log.h"
+#include "opts.h"
+#include "peer.h"
+#include "uuid.h"
+
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+
+static FILE *log_stream = NULL;
+static char *log_path = NULL;
+static uint8_t log_id[UUID_LEN];
+static struct peer log_rotate_peer;
+static bool log_timestamps = false;
+static bool log_quiet = false;
+static opts_group log_opts;
+
+static char log_module = 'L';
+
+static void log_open() {
+	if (!log_path) {
+		return;
+	}
+	int fd = open(log_path, O_WRONLY | O_CREAT | O_APPEND | O_NOCTTY | O_CLOEXEC, S_IRUSR | S_IWUSR);
+	assert(fd >= 0);
+	assert(dup3(fd, STDERR_FILENO, O_CLOEXEC) == STDERR_FILENO);
+	assert(!close(fd));
+}
+
+static void log_rotate() {
+	assert(log_path);
+
+	uint8_t old_log_id[UUID_LEN], new_log_id[UUID_LEN];
+	uuid_gen(new_log_id);
+	LOG(log_id, "Switching to new log with ID %s at: %s", new_log_id, log_path);
+	memcpy(old_log_id, log_id, UUID_LEN);
+	memcpy(log_id, new_log_id, UUID_LEN);
+	log_open();
+	LOG(log_id, "Log start after switch from log ID %s", old_log_id);
+}
+
+static void log_rotate_handler(struct peer *peer) {
+	struct signalfd_siginfo siginfo;
+	assert(read(peer->fd, &siginfo, sizeof(siginfo)) == sizeof(siginfo));
+	LOG(log_id, "Received signal %u; rotating logs", siginfo.ssi_signo);
+	log_rotate();
+}
+
+static bool log_set_path(const char *path) {
+	if (log_path) {
+		return false;
+	}
+	log_path = strdup(path);
+	assert(log_path);
+	return true;
+}
+
+static bool log_enable_timestamps(const char __attribute__ ((unused)) *arg) {
+	log_timestamps = true;
+	return true;
+}
+
+static bool log_set_quiet(const char __attribute__ ((unused)) *arg) {
+	log_quiet = true;
+	return true;
+}
+
+void log_opts_add() {
+	opts_add("log-file", "PATH", log_set_path, log_opts);
+	opts_add("log-timestamps", NULL, log_enable_timestamps, log_opts);
+	opts_add("quiet", NULL, log_set_quiet, log_opts);
+}
+
+void log_init() {
+	opts_call(log_opts);
+	log_open();
+	log_stream = fdopen(STDERR_FILENO, "a");
+	assert(log_stream);
+	setlinebuf(log_stream);
+
+	uuid_gen(log_id);
+	LOG(log_id, "Log start");
+}
+
+void log_init_peer() {
+	if (log_path) {
+		sigset_t sigmask;
+		assert(!sigemptyset(&sigmask));
+		assert(!sigaddset(&sigmask, SIGHUP));
+		log_rotate_peer.fd = signalfd(-1, &sigmask, SFD_NONBLOCK | SFD_CLOEXEC);
+		assert(log_rotate_peer.fd >= 0);
+		log_rotate_peer.event_handler = log_rotate_handler;
+		peer_epoll_add(&log_rotate_peer, EPOLLIN);
+
+		assert(!sigprocmask(SIG_BLOCK, &sigmask, NULL));
+	} else {
+		log_rotate_peer.fd = -1;
+	}
+}
+
+void log_cleanup_peer() {
+	peer_close(&log_rotate_peer);
+}
+
+void log_cleanup() {
+	LOG(log_id, "Log end");
+	assert(!fclose(log_stream));
+	if (log_path) {
+		free(log_path);
+		log_path = NULL;
+	}
+}
+
+void log_write(char type, const char *loc, const uint8_t *id, const char *fmt, ...) {
+	if (log_quiet) {
+		return;
+	}
+
+	va_list ap;
+	va_start(ap, fmt);
+
+	char datetime[64] = "";
+	if (log_timestamps) {
+		time_t now;
+		assert(time(&now) >= 0);
+		struct tm tmnow;
+		assert(gmtime_r(&now, &tmnow));
+		assert(strftime(datetime, sizeof(datetime), "%FT%TZ ", &tmnow) > 0);
+	}
+
+	assert(fprintf(log_stream, "%s[%18s] %c %s: ", datetime, loc, type, id) > 0);
+	assert(vfprintf(log_stream, fmt, ap) > 0);
+	assert(fprintf(log_stream, "\n") == 1);
+	va_end(ap);
+}
diff --git a/adsbus/log.h b/adsbus/log.h
new file mode 100644
index 0000000..6494eb6
--- /dev/null
+++ b/adsbus/log.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define LOG_STR(line) #line
+#define LOG_LOC(file, line) (file ":" LOG_STR(line))
+#define LOG(id, ...) log_write((log_module), LOG_LOC(__FILE__, __LINE__), (id), __VA_ARGS__)
+
+void log_opts_add(void);
+void log_init(void);
+void log_cleanup(void);
+void log_init_peer(void);
+void log_cleanup_peer(void);
+void log_write(char, const char *, const uint8_t *, const char *, ...)
+		__attribute__ ((__format__ (__printf__, 4, 5)));
diff --git a/adsbus/opts.c b/adsbus/opts.c
index 0b39e88..7218fdb 100644
--- a/adsbus/opts.c
+++ b/adsbus/opts.c
@@ -1,23 +1,91 @@
 #include <assert.h>
-#include <fcntl.h>
+#include <getopt.h>
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include "exec.h"
-#include "file.h"
-#include "flow.h"
-#include "incoming.h"
-#include "outgoing.h"
-#include "receive.h"
-#include "send.h"
-#include "send_receive.h"
 
 #include "opts.h"
 
-static char *opts_split(char **arg, char delim) {
+#define OPTS_MAX 128
+
+static struct {
+	const char *arg_help;
+	opts_handler handler;
+	void *group;
+} opts[OPTS_MAX];
+
+static struct option opts_long[OPTS_MAX];
+static size_t opts_num = 0;
+static int opts_argc;
+static char **opts_argv;
+static opts_group opts_group_internal;
+
+static void opts_print_usage() {
+	fprintf(stderr,
+			"Usage: %s [OPTION]...\n"
+			"\n"
+			"Options:\n"
+			, opts_argv[0]);
+	for (size_t i = 0; i < opts_num; i++) {
+		fprintf(stderr, "\t--%s%s%s\n", opts_long[i].name, opts[i].arg_help ? "=" : "", opts[i].arg_help ? opts[i].arg_help : "");
+	}
+}
+
+static bool opts_help(const char __attribute__ ((unused)) *arg) {
+	opts_print_usage();
+	exit(EXIT_SUCCESS);
+}
+
+void opts_init(int argc, char *argv[]) {
+	opts_argc = argc;
+	opts_argv = argv;
+	opts_add("help", NULL, opts_help, opts_group_internal);
+
+	assert(opts_num < OPTS_MAX);
+	opts_long[opts_num].name = NULL;
+	opts_long[opts_num].has_arg = 0;
+	opts_long[opts_num].flag = NULL;
+	opts_long[opts_num].val = 0;
+
+	opts_call(opts_group_internal);
+}
+
+void opts_add(const char *name, const char *arg_help, opts_handler handler, opts_group group) {
+	assert(opts_num < OPTS_MAX);
+	opts[opts_num].arg_help = arg_help;
+	opts[opts_num].handler = handler;
+	opts[opts_num].group = group;
+	opts_long[opts_num].name = name;
+	opts_long[opts_num].has_arg = arg_help ? required_argument : no_argument;
+	opts_long[opts_num].flag = NULL;
+	opts_long[opts_num].val = 0;
+	opts_num++;
+}
+
+void opts_call(opts_group group) {
+	optind = 1;
+	int opt, longindex;
+	while ((opt = getopt_long_only(opts_argc, opts_argv, "", opts_long, &longindex)) == 0) {
+		if (opts[longindex].group != group) {
+			continue;
+		}
+		if (!opts[longindex].handler(optarg)) {
+			fprintf(stderr, "Invalid option value: %s\n", opts_argv[optind - 1]);
+			exit(EXIT_FAILURE);
+		}
+	}
+	if (opt != -1) {
+		opts_print_usage();
+		exit(EXIT_FAILURE);
+	}
+
+	if (optind != opts_argc) {
+		fprintf(stderr, "Not a flag: %s\n", opts_argv[optind]);
+		exit(EXIT_FAILURE);
+	}
+}
+
+char *opts_split(const char **arg, char delim) {
 	char *split = strchr(*arg, delim);
 	if (!split) {
 		return NULL;
@@ -26,137 +94,3 @@ static char *opts_split(char **arg, char delim) {
 	*arg = split + 1;
 	return ret;
 }
-
-static bool opts_add_listen(char *host_port, struct flow *flow, void *passthrough) {
-	char *host = opts_split(&host_port, '/');
-	if (host) {
-		incoming_new(host, host_port, flow, passthrough);
-		free(host);
-	} else {
-		incoming_new(NULL, host_port, flow, passthrough);
-	}
-	return true;
-}
-
-static bool opts_add_connect(char *host_port, struct flow *flow, void *passthrough) {
-	char *host = opts_split(&host_port, '/');
-	if (!host) {
-		return false;
-	}
-
-	outgoing_new(host, host_port, flow, passthrough);
-	free(host);
-	return true;
-}
-
-static bool opts_add_file_write_int(char *path, struct flow *flow, void *passthrough) {
-	file_write_new(path, flow, passthrough);
-	return true;
-}
-
-static bool opts_add_file_append_int(char *path, struct flow *flow, void *passthrough) {
-	file_append_new(path, flow, passthrough);
-	return true;
-}
-
-static bool opts_add_exec(char *cmd, struct flow *flow, void *passthrough) {
-	exec_new(cmd, flow, passthrough);
-	return true;
-}
-
-static struct serializer *opts_get_serializer(char **arg) {
-	char *format = opts_split(arg, '=');
-	if (!format) {
-		return NULL;
-	}
-
-	struct serializer *serializer = send_get_serializer(format);
-	free(format);
-	if (!serializer) {
-		return NULL;
-	}
-
-	return serializer;
-}
-
-static bool opts_add_send(bool (*next)(char *, struct flow *, void *), struct flow *flow, char *arg) {
-	struct serializer *serializer = opts_get_serializer(&arg);
-	if (!serializer) {
-		return false;
-	}
-	return next(arg, flow, serializer);
-}
-
-bool opts_add_connect_receive(char *arg) {
-	return opts_add_connect(arg, receive_flow, NULL);
-}
-
-bool opts_add_connect_send(char *arg) {
-	return opts_add_send(opts_add_connect, send_flow, arg);
-}
-
-bool opts_add_connect_send_receive(char *arg) {
-	return opts_add_send(opts_add_connect, send_receive_flow, arg);
-}
-
-bool opts_add_listen_receive(char *arg) {
-	return opts_add_listen(arg, receive_flow, NULL);
-}
-
-bool opts_add_listen_send(char *arg) {
-	return opts_add_send(opts_add_listen, send_flow, arg);
-}
-
-bool opts_add_listen_send_receive(char *arg) {
-	return opts_add_send(opts_add_listen, send_receive_flow, arg);
-}
-
-bool opts_add_file_read(char *arg) {
-	file_read_new(arg, receive_flow, NULL);
-	return true;
-}
-
-bool opts_add_file_write(char *arg) {
-	return opts_add_send(opts_add_file_write_int, send_flow, arg);
-}
-
-bool opts_add_file_write_read(char *arg) {
-	return opts_add_send(opts_add_file_write_int, send_receive_flow, arg);
-}
-
-bool opts_add_file_append(char *arg) {
-	return opts_add_send(opts_add_file_append_int, send_flow, arg);
-}
-
-bool opts_add_file_append_read(char *arg) {
-	return opts_add_send(opts_add_file_append_int, send_receive_flow, arg);
-}
-
-bool opts_add_exec_receive(char *arg) {
-	exec_new(arg, receive_flow, NULL);
-	return true;
-}
-
-bool opts_add_exec_send(char *arg) {
-	return opts_add_send(opts_add_exec, send_flow, arg);
-}
-
-bool opts_add_exec_send_receive(char *arg) {
-	return opts_add_send(opts_add_exec, send_receive_flow, arg);
-}
-
-bool opts_add_stdin(char __attribute__((unused)) *arg) {
-	int fd = fcntl(STDIN_FILENO, F_DUPFD_CLOEXEC, 0);
-	assert(fd >= 0);
-	return flow_new_send_hello(fd, receive_flow, NULL, NULL);
-}
-
-bool opts_add_stdout(char *arg) {
-	struct serializer *serializer = send_get_serializer(arg);
-	if (!serializer) {
-		return false;
-	}
-	int fd = fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
-	assert(fd >= 0);
-	return flow_new_send_hello(fd, send_flow, serializer, NULL);
-}
diff --git a/adsbus/opts.h b/adsbus/opts.h
index 3c03ce8..4f832ae 100644
--- a/adsbus/opts.h
+++ b/adsbus/opts.h
@@ -2,19 +2,10 @@
 
 #include <stdbool.h>
 
-bool opts_add_connect_receive(char *);
-bool opts_add_connect_send(char *);
-bool opts_add_connect_send_receive(char *);
-bool opts_add_listen_receive(char *);
-bool opts_add_listen_send(char *);
-bool opts_add_listen_send_receive(char *);
-bool opts_add_file_read(char *);
-bool opts_add_file_write(char *);
-bool opts_add_file_write_read(char *);
-bool opts_add_file_append(char *);
-bool opts_add_file_append_read(char *);
-bool opts_add_exec_receive(char *);
-bool opts_add_exec_send(char *);
-bool opts_add_exec_send_receive(char *);
-bool opts_add_stdout(char *);
-bool opts_add_stdin(char *);
+typedef bool (*opts_handler)(const char *);
+typedef char opts_group[1];
+
+void opts_init(int, char *[]);
+void opts_add(const char *, const char *, opts_handler, opts_group);
+void opts_call(opts_group);
+char *opts_split(const char **, char);
diff --git a/adsbus/outgoing.c b/adsbus/outgoing.c
index 6ccf25b..a868579 100644
--- a/adsbus/outgoing.c
+++ b/adsbus/outgoing.c
@@ -1,19 +1,22 @@
-#include <stdlib.h>
-#include <stdio.h>
 #include <assert.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netdb.h>
 #include <errno.h>
+#include <netdb.h>
+#include <stdlib.h>
 #include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 #include "buf.h"
 #include "flow.h"
-#include "list.h"
+#include "log.h"
+#include "opts.h"
 #include "peer.h"
+#include "receive.h"
 #include "resolve.h"
-#include "socket.h"
+#include "send.h"
+#include "send_receive.h"
 #include "wakeup.h"
 #include "uuid.h"
 
@@ -33,29 +36,33 @@ struct outgoing {
 };
 
 static struct list_head outgoing_head = LIST_HEAD_INIT(outgoing_head);
+static opts_group outgoing_opts;
+
+static char log_module = 'O';
 
 static void outgoing_connect_result(struct outgoing *, int);
 static void outgoing_resolve(struct outgoing *);
 static void outgoing_resolve_wrapper(struct peer *);
 
 static void outgoing_retry(struct outgoing *outgoing) {
+	outgoing->peer.fd = -1;
 	uint32_t delay = wakeup_get_retry_delay_ms(++outgoing->attempt);
-	fprintf(stderr, "O %s: Will retry in %ds\n", outgoing->id, delay / 1000);
+	LOG(outgoing->id, "Will retry in %ds", delay / 1000);
 	outgoing->peer.event_handler = outgoing_resolve_wrapper;
-	wakeup_add((struct peer *) outgoing, delay);
+	wakeup_add(&outgoing->peer, delay);
 }
 
 static void outgoing_connect_next(struct outgoing *outgoing) {
 	if (outgoing->addr == NULL) {
 		freeaddrinfo(outgoing->addrs);
-		fprintf(stderr, "O %s: Can't connect to any addresses of %s/%s\n", outgoing->id, outgoing->node, outgoing->service);
+		LOG(outgoing->id, "Can't connect to any addresses of %s/%s", outgoing->node, outgoing->service);
 		outgoing_retry(outgoing);
 		return;
 	}
 
 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
 	assert(getnameinfo(outgoing->addr->ai_addr, outgoing->addr->ai_addrlen, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0);
-	fprintf(stderr, "O %s: Connecting to %s/%s...\n", outgoing->id, hbuf, sbuf);
+	LOG(outgoing->id, "Connecting to %s/%s...", hbuf, sbuf);
 
 	outgoing->peer.fd = socket(outgoing->addr->ai_family, outgoing->addr->ai_socktype | SOCK_NONBLOCK | SOCK_CLOEXEC, outgoing->addr->ai_protocol);
 	assert(outgoing->peer.fd >= 0);
@@ -67,7 +74,7 @@ static void outgoing_connect_next(struct outgoing *outgoing) {
 }
 
 static void outgoing_connect_handler(struct peer *peer) {
-	struct outgoing *outgoing = (struct outgoing *) peer;
+	struct outgoing *outgoing = container_of(peer, struct outgoing, peer);
 
 	peer_epoll_del(&outgoing->peer);
 
@@ -78,11 +85,8 @@ static void outgoing_connect_handler(struct peer *peer) {
 }
 
 static void outgoing_disconnect_handler(struct peer *peer) {
-	struct outgoing *outgoing = (struct outgoing *) peer;
-	if (outgoing->peer.fd != -1) {
-		assert(!close(outgoing->peer.fd));
-	}
-	fprintf(stderr, "O %s: Peer disconnected; reconnecting...\n", outgoing->id);
+	struct outgoing *outgoing = container_of(peer, struct outgoing, peer);
+	LOG(outgoing->id, "Peer disconnected; reconnecting...");
 	outgoing_retry(outgoing);
 }
 
@@ -91,7 +95,7 @@ static void outgoing_connect_result(struct outgoing *outgoing, int result) {
 	assert(getnameinfo(outgoing->addr->ai_addr, outgoing->addr->ai_addrlen, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0);
 	switch (result) {
 		case 0:
-			fprintf(stderr, "O %s: Connected to %s/%s\n", outgoing->id, hbuf, sbuf);
+			LOG(outgoing->id, "Connected to %s/%s", hbuf, sbuf);
 			freeaddrinfo(outgoing->addrs);
 			outgoing->attempt = 0;
 			int fd = outgoing->peer.fd;
@@ -99,18 +103,17 @@ static void outgoing_connect_result(struct outgoing *outgoing, int result) {
 			outgoing->peer.event_handler = outgoing_disconnect_handler;
 			flow_socket_ready(fd, outgoing->flow);
 			flow_socket_connected(fd, outgoing->flow);
-			flow_new(fd, outgoing->flow, outgoing->passthrough, (struct peer *) outgoing);
+			flow_new(fd, outgoing->flow, outgoing->passthrough, &outgoing->peer);
 			break;
 
 		case EINPROGRESS:
 			outgoing->peer.event_handler = outgoing_connect_handler;
-			peer_epoll_add((struct peer *) outgoing, EPOLLOUT);
+			peer_epoll_add(&outgoing->peer, EPOLLOUT);
 			break;
 
 		default:
-			fprintf(stderr, "O %s: Can't connect to %s/%s: %s\n", outgoing->id, hbuf, sbuf, strerror(result));
+			LOG(outgoing->id, "Can't connect to %s/%s: %s", hbuf, sbuf, strerror(result));
 			assert(!close(outgoing->peer.fd));
-			outgoing->peer.fd = -1;
 			outgoing->addr = outgoing->addr->ai_next;
 			// Tail recursion :/
 			outgoing_connect_next(outgoing);
@@ -119,10 +122,10 @@ static void outgoing_connect_result(struct outgoing *outgoing, int result) {
 }
 
 static void outgoing_resolve_handler(struct peer *peer) {
-	struct outgoing *outgoing = (struct outgoing *) peer;
+	struct outgoing *outgoing = container_of(peer, struct outgoing, peer);
 	int err = resolve_result(peer, &outgoing->addrs);
 	if (err) {
-		fprintf(stderr, "O %s: Failed to resolve %s/%s: %s\n", outgoing->id, outgoing->node, outgoing->service, gai_strerror(err));
+		LOG(outgoing->id, "Failed to resolve %s/%s: %s", outgoing->node, outgoing->service, gai_strerror(err));
 		outgoing_retry(outgoing);
 	} else {
 		outgoing->addr = outgoing->addrs;
@@ -131,26 +134,57 @@ static void outgoing_resolve_handler(struct peer *peer) {
 }
 
 static void outgoing_resolve(struct outgoing *outgoing) {
-	fprintf(stderr, "O %s: Resolving %s/%s...\n", outgoing->id, outgoing->node, outgoing->service);
+	LOG(outgoing->id, "Resolving %s/%s...", outgoing->node, outgoing->service);
 	outgoing->peer.event_handler = outgoing_resolve_handler;
-	resolve((struct peer *) outgoing, outgoing->node, outgoing->service, 0);
+	resolve(&outgoing->peer, outgoing->node, outgoing->service, 0);
 }
 
 static void outgoing_resolve_wrapper(struct peer *peer) {
-	outgoing_resolve((struct outgoing *) peer);
+	outgoing_resolve(container_of(peer, struct outgoing, peer));
 }
 
 static void outgoing_del(struct outgoing *outgoing) {
 	flow_ref_dec(outgoing->flow);
-	if (outgoing->peer.fd >= 0) {
-		assert(!close(outgoing->peer.fd));
-	}
+	peer_close(&outgoing->peer);
 	list_del(&outgoing->outgoing_list);
 	free(outgoing->node);
 	free(outgoing->service);
 	free(outgoing);
 }
 
+static bool outgoing_add(const char *host_port, struct flow *flow, void *passthrough) {
+	char *host = opts_split(&host_port, '/');
+	if (!host) {
+		return false;
+	}
+
+	outgoing_new(host, host_port, flow, passthrough);
+	free(host);
+	return true;
+}
+
+static bool outgoing_connect_receive(const char *arg) {
+	return outgoing_add(arg, receive_flow, NULL);
+}
+
+static bool outgoing_connect_send(const char *arg) {
+	return send_add(outgoing_add, send_flow, arg);
+}
+
+static bool outgoing_connect_send_receive(const char *arg) {
+	return send_add(outgoing_add, send_receive_flow, arg);
+}
+
+void outgoing_opts_add() {
+	opts_add("connect-receive", "HOST/PORT", outgoing_connect_receive, outgoing_opts);
+	opts_add("connect-send", "FORMAT=HOST/PORT", outgoing_connect_send, outgoing_opts);
+	opts_add("connect-send-receive", "FORMAT=HOST/PORT", outgoing_connect_send_receive, outgoing_opts);
+}
+
+void outgoing_init() {
+	opts_call(outgoing_opts);
+}
+
 void outgoing_cleanup() {
 	struct outgoing *iter, *next;
 	list_for_each_entry_safe(iter, next, &outgoing_head, outgoing_list) {
@@ -158,7 +192,7 @@ void outgoing_cleanup() {
 	}
 }
 
-void outgoing_new(char *node, char *service, struct flow *flow, void *passthrough) {
+void outgoing_new(const char *node, const char *service, struct flow *flow, void *passthrough) {
 	flow_ref_inc(flow);
 
 	struct outgoing *outgoing = malloc(sizeof(*outgoing));
diff --git a/adsbus/outgoing.h b/adsbus/outgoing.h
index c39fdc5..4333dd0 100644
--- a/adsbus/outgoing.h
+++ b/adsbus/outgoing.h
@@ -2,5 +2,7 @@
 
 struct flow;
 
+void outgoing_opts_add(void);
+void outgoing_init(void);
 void outgoing_cleanup(void);
-void outgoing_new(char *, char *, struct flow *, void *);
+void outgoing_new(const char *, const char *, struct flow *, void *);
diff --git a/adsbus/packet.c b/adsbus/packet.c
index 6232e81..3dfd461 100644
--- a/adsbus/packet.c
+++ b/adsbus/packet.c
@@ -1,7 +1,6 @@
 #pragma GCC diagnostic ignored "-Wtautological-constant-out-of-range-compare"
 
 #include <assert.h>
-#include <stdio.h>
 #include <string.h>
 
 #include "uuid.h"
diff --git a/adsbus/peer.c b/adsbus/peer.c
index 3c8f70e..067f533 100644
--- a/adsbus/peer.c
+++ b/adsbus/peer.c
@@ -1,61 +1,61 @@
 #include <assert.h>
 #include <errno.h>
-#include <fcntl.h>
 #include <signal.h>
 #include <stdbool.h>
-#include <stdio.h>
 #include <stdlib.h>
-#include <sys/epoll.h>
+#include <string.h>
+#include <sys/signalfd.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
+#include "log.h"
 #include "server.h"
-#include "uuid.h"
-#include "wakeup.h"
 
 #include "peer.h"
 
+static char log_module = 'X';
+
 uint32_t peer_count_in = 0, peer_count_out = 0, peer_count_out_in = 0;
 
 static int peer_epoll_fd;
-static int peer_shutdown_fd;
+static struct peer peer_shutdown_peer;
 static bool peer_shutdown_flag = false;
 static struct list_head peer_always_trigger_head = LIST_HEAD_INIT(peer_always_trigger_head);
 
-static void peer_shutdown_handler(struct peer *peer) {
-	fprintf(stderr, "X %s: Shutting down\n", server_id);
-	assert(!close(peer->fd));
-	free(peer);
+static void peer_shutdown() {
+	peer_close(&peer_shutdown_peer);
 	peer_shutdown_flag = true;
 }
 
+static void peer_shutdown_handler(struct peer *peer) {
+	struct signalfd_siginfo siginfo;
+	assert(read(peer->fd, &siginfo, sizeof(siginfo)) == sizeof(siginfo));
+	LOG(server_id, "Received signal %u; shutting down", siginfo.ssi_signo);
+	peer_shutdown();
+}
+
 void peer_init() {
 	peer_epoll_fd = epoll_create1(EPOLL_CLOEXEC);
 	assert(peer_epoll_fd >= 0);
 
-	int shutdown_fds[2];
-	assert(!pipe2(shutdown_fds, O_CLOEXEC));
+	sigset_t sigmask;
+	assert(!sigemptyset(&sigmask));
+	assert(!sigaddset(&sigmask, SIGINT));
+	assert(!sigaddset(&sigmask, SIGTERM));
+	peer_shutdown_peer.fd = signalfd(-1, &sigmask, SFD_NONBLOCK | SFD_CLOEXEC);
+	assert(peer_shutdown_peer.fd >= 0);
+	peer_shutdown_peer.event_handler = peer_shutdown_handler;
+	peer_epoll_add(&peer_shutdown_peer, EPOLLIN);
 
-	struct peer *shutdown_peer = malloc(sizeof(*shutdown_peer));
-	assert(shutdown_peer);
-	shutdown_peer->fd = shutdown_fds[0];
-	shutdown_peer->event_handler = peer_shutdown_handler;
-	peer_epoll_add(shutdown_peer, EPOLLRDHUP);
-
-	peer_shutdown_fd = shutdown_fds[1];
-	signal(SIGINT, peer_shutdown);
+	assert(!sigprocmask(SIG_BLOCK, &sigmask, NULL));
 }
 
 void peer_cleanup() {
 	assert(!close(peer_epoll_fd));
 }
 
-void peer_shutdown(int __attribute__((unused)) signal) {
-	if (peer_shutdown_fd != -1) {
-		assert(!close(peer_shutdown_fd));
-		peer_shutdown_fd = -1;
-	}
-}
-
 void peer_epoll_add(struct peer *peer, uint32_t events) {
 	struct epoll_event ev = {
 		.events = events,
@@ -87,6 +87,15 @@ void peer_epoll_del(struct peer *peer) {
 	}
 }
 
+void peer_close(struct peer *peer) {
+	if (peer->fd == -1) {
+		return;
+	}
+	peer_epoll_del(peer);
+	assert(!close(peer->fd));
+	peer->fd = -1;
+}
+
 void peer_call(struct peer *peer) {
 	if (peer_shutdown_flag || !peer) {
 		return;
@@ -95,18 +104,20 @@ void peer_call(struct peer *peer) {
 }
 
 void peer_loop() {
-	fprintf(stderr, "X %s: Starting event loop\n", server_id);
+	LOG(server_id, "Starting event loop");
 	while (!peer_shutdown_flag) {
 		if (!(peer_count_in + peer_count_out_in)) {
-			fprintf(stderr, "X %s: No remaining inputs\n", server_id);
-			peer_shutdown(0);
+			LOG(server_id, "No remaining inputs");
+			peer_shutdown();
+			break;
 		} else if (!(peer_count_out + peer_count_out_in)) {
-			fprintf(stderr, "X %s: No remaining outputs\n", server_id);
-			peer_shutdown(0);
+			LOG(server_id, "No remaining outputs");
+			peer_shutdown();
+			break;
 		}
 #define MAX_EVENTS 10
 		struct epoll_event events[MAX_EVENTS];
-		int delay = list_is_empty(&peer_always_trigger_head) ? wakeup_get_delay() : 0;
+		int delay = list_is_empty(&peer_always_trigger_head) ? -1 : 0;
 		int nfds = epoll_wait(peer_epoll_fd, events, MAX_EVENTS, delay);
 		if (nfds == -1 && errno == EINTR) {
 			continue;
@@ -124,7 +135,5 @@ void peer_loop() {
 				peer_call(iter);
 			}
 		}
-
-		wakeup_dispatch();
 	}
 }
diff --git a/adsbus/peer.h b/adsbus/peer.h
index 1b380ea..9b39f94 100644
--- a/adsbus/peer.h
+++ b/adsbus/peer.h
@@ -18,8 +18,8 @@ extern uint32_t peer_count_in, peer_count_out, peer_count_out_in;
 
 void peer_init(void);
 void peer_cleanup(void);
-void peer_shutdown(int signal);
 void peer_epoll_add(struct peer *, uint32_t);
 void peer_epoll_del(struct peer *);
+void peer_close(struct peer *);
 void peer_call(struct peer *);
 void peer_loop(void);
diff --git a/adsbus/proto.c b/adsbus/proto.c
index d85cc25..36a6cf9 100644
--- a/adsbus/proto.c
+++ b/adsbus/proto.c
@@ -1,19 +1,17 @@
-#pragma GCC diagnostic ignored "-Wcast-qual"
-#pragma GCC diagnostic ignored "-Wpacked"
-
-#include <arpa/inet.h>
-#include <assert.h>
-#include <stdio.h>
+#include <stdbool.h>
 #include <string.h>
 
 #include "buf.h"
+#include "log.h"
 #include "packet.h"
 #include "server.h"
-#include "uuid.h"
 
 #include "adsb.pb-c.h"
 #include "proto.h"
 
+#pragma GCC diagnostic ignored "-Wcast-qual"
+#pragma GCC diagnostic ignored "-Wpacked"
+
 #define PROTO_MAGIC "aDsB"
 
 struct proto_parser_state {
@@ -24,6 +22,8 @@ struct proto_parser_state {
 	bool have_header;
 };
 
+static char log_module = 'R'; // borrowing
+
 static Adsb *proto_prev = NULL;
 static struct buf proto_hello_buf = BUF_INIT;
 
@@ -145,12 +145,12 @@ static bool proto_parse_header(AdsbHeader *header, struct packet *packet, struct
 	state->rssi_max = header->rssi_max;
 
 	if (!strcmp(header->server_id, (const char *) server_id)) {
-		fprintf(stderr, "R %s: Attempt to receive proto data from our own server ID (%s); loop!\n", packet->source_id, server_id);
+		LOG(packet->source_id, "Attempt to receive proto data from our own server ID (%s); loop!", server_id);
 		return false;
 	}
 
 	state->have_header = true;
-	fprintf(stderr, "R %s: Connected to server ID: %s\n", packet->source_id, header->server_id);
+	LOG(packet->source_id, "Connected to server ID: %s", header->server_id);
 	return true;
 }
 
diff --git a/adsbus/rand.c b/adsbus/rand.c
index 82d6563..b4d27f1 100644
--- a/adsbus/rand.c
+++ b/adsbus/rand.c
@@ -1,7 +1,6 @@
 #include <assert.h>
 #include <fcntl.h>
 #include <limits.h>
-#include <stdio.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -16,7 +15,7 @@ static struct buf rand_buf = BUF_INIT;
 static int rand_fd;
 
 void rand_init() {
-	rand_fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC);
+	rand_fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC | O_NOCTTY);
 	assert(rand_fd >= 0);
 	assert(read(rand_fd, buf_at(&rand_buf, 0), BUF_LEN_MAX) == BUF_LEN_MAX);
 	rand_buf.length = BUF_LEN_MAX;
diff --git a/adsbus/raw.c b/adsbus/raw.c
index bcceb3d..b176b06 100644
--- a/adsbus/raw.c
+++ b/adsbus/raw.c
@@ -1,11 +1,8 @@
 #include <assert.h>
-#include <stdio.h>
-#include <string.h>
 
 #include "buf.h"
 #include "hex.h"
 #include "packet.h"
-#include "uuid.h"
 
 #include "raw.h"
 
diff --git a/adsbus/receive.c b/adsbus/receive.c
index 8b34095..189e6b6 100644
--- a/adsbus/receive.c
+++ b/adsbus/receive.c
@@ -1,18 +1,16 @@
 #include <assert.h>
-#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/socket.h>
 #include <sys/stat.h>
-#include <unistd.h>
+#include <sys/types.h>
 
 #include "airspy_adsb.h"
 #include "beast.h"
 #include "buf.h"
 #include "flow.h"
 #include "json.h"
-#include "list.h"
+#include "log.h"
 #include "packet.h"
 #include "peer.h"
 #include "proto.h"
@@ -39,6 +37,8 @@ struct receive {
 };
 static struct list_head receive_head = LIST_HEAD_INIT(receive_head);
 
+static char log_module = 'R';
+
 static void receive_new(int, void *, struct peer *);
 
 static struct flow _receive_flow = {
@@ -92,7 +92,7 @@ static bool receive_autodetect_parse(struct receive *receive, struct packet *pac
 
 	for (size_t i = 0; i < NUM_PARSERS; i++) {
 		if (parsers[i].parse(buf, packet, state)) {
-			fprintf(stderr, "R %s: Detected input format %s\n", receive->id, parsers[i].name);
+			LOG(receive->id, "Detected input format: %s", parsers[i].name);
 			receive->parser_wrapper = receive_parse_wrapper;
 			receive->parser = parsers[i].parse;
 			return true;
@@ -105,17 +105,16 @@ static bool receive_autodetect_parse(struct receive *receive, struct packet *pac
 }
 
 static void receive_del(struct receive *receive) {
-	fprintf(stderr, "R %s: Connection closed\n", receive->id);
+	LOG(receive->id, "Connection closed");
 	peer_count_in--;
-	peer_epoll_del((struct peer *) receive);
-	assert(!close(receive->peer.fd));
+	peer_close(&receive->peer);
 	list_del(&receive->receive_list);
 	peer_call(receive->on_close);
 	free(receive);
 }
 
 static void receive_read(struct peer *peer) {
-	struct receive *receive = (struct receive *) peer;
+	struct receive *receive = container_of(peer, struct receive, peer);
 
 	if (buf_fill(&receive->buf, receive->peer.fd) <= 0) {
 		receive_del(receive);
@@ -134,14 +133,14 @@ static void receive_read(struct peer *peer) {
 			continue;
 		}
 		if (++packet.hops > receive_max_hops) {
-			fprintf(stderr, "R %s: Packet exceeded hop limit (%u > %u); dropping. You may have a loop in your configuration.\n", receive->id, packet.hops, receive_max_hops);
+			LOG(receive->id, "Packet exceeded hop limit (%u > %u); dropping. You may have a loop in your configuration.", packet.hops, receive_max_hops);
 			continue;
 		}
 		send_write(&packet);
 	}
 
 	if (receive->buf.length == BUF_LEN_MAX) {
-		fprintf(stderr, "R %s: Input buffer overrun. This probably means that adsbus doesn't understand the protocol that this source is speaking.\n", receive->id);
+		LOG(receive->id, "Input buffer overrun. This probably means that adsbus doesn't understand the protocol that this source is speaking.");
 		receive_del(receive);
 		return;
 	}
@@ -164,9 +163,9 @@ static void receive_new(int fd, void __attribute__((unused)) *passthrough, struc
 
 	list_add(&receive->receive_list, &receive_head);
 
-	peer_epoll_add((struct peer *) receive, EPOLLIN);
+	peer_epoll_add(&receive->peer, EPOLLIN);
 
-	fprintf(stderr, "R %s: New receive connection\n", receive->id);
+	LOG(receive->id, "New receive connection");
 }
 
 void receive_init() {
diff --git a/adsbus/resolve.c b/adsbus/resolve.c
index 35d4864..57f05c6 100644
--- a/adsbus/resolve.c
+++ b/adsbus/resolve.c
@@ -1,5 +1,3 @@
-#include <sys/types.h>
-#include <sys/socket.h>
 #include <netdb.h>
 
 #include "asyncaddrinfo.h"
diff --git a/adsbus/send.c b/adsbus/send.c
index 5522442..77b0732 100644
--- a/adsbus/send.c
+++ b/adsbus/send.c
@@ -1,7 +1,5 @@
 #include <assert.h>
-#include <errno.h>
 #include <signal.h>
-#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <strings.h>
@@ -15,7 +13,8 @@
 #include "buf.h"
 #include "flow.h"
 #include "json.h"
-#include "list.h"
+#include "log.h"
+#include "opts.h"
 #include "packet.h"
 #include "peer.h"
 #include "proto.h"
@@ -47,6 +46,8 @@ static struct flow _send_flow = {
 };
 struct flow *send_flow = &_send_flow;
 
+static char log_module = 'S';
+
 typedef void (*serialize)(struct packet *, struct buf *);
 typedef void (*hello)(struct buf **);
 static struct serializer {
@@ -89,17 +90,16 @@ static struct serializer {
 #define NUM_SERIALIZERS (sizeof(serializers) / sizeof(*serializers))
 
 static void send_del(struct send *send) {
-	fprintf(stderr, "S %s (%s): Connection closed\n", send->id, send->serializer->name);
+	LOG(send->id, "Connection closed");
 	peer_count_out--;
-	peer_epoll_del((struct peer *) send);
-	assert(!close(send->peer.fd));
+	peer_close(&send->peer);
 	list_del(&send->send_list);
 	peer_call(send->on_close);
 	free(send);
 }
 
 static void send_del_wrapper(struct peer *peer) {
-	send_del((struct send *) peer);
+	send_del(container_of(peer, struct send, peer));
 }
 
 static void send_new(int fd, void *passthrough, struct peer *on_close) {
@@ -119,9 +119,24 @@ static void send_new(int fd, void *passthrough, struct peer *on_close) {
 
 	list_add(&send->send_list, &serializer->send_head);
 
-	peer_epoll_add((struct peer *) send, 0);
+	peer_epoll_add(&send->peer, 0);
 
-	fprintf(stderr, "S %s (%s): New send connection\n", send->id, serializer->name);
+	LOG(send->id, "New send connection: %s", serializer->name);
+}
+
+static struct serializer *send_parse_format(const char **arg) {
+	char *format = opts_split(arg, '=');
+	if (!format) {
+		return NULL;
+	}
+
+	struct serializer *serializer = send_get_serializer(format);
+	free(format);
+	if (!serializer) {
+		return NULL;
+	}
+
+	return serializer;
 }
 
 void send_init() {
@@ -140,7 +155,7 @@ void send_cleanup() {
 	}
 }
 
-void *send_get_serializer(char *name) {
+void *send_get_serializer(const char *name) {
 	for (size_t i = 0; i < NUM_SERIALIZERS; i++) {
 		if (strcasecmp(serializers[i].name, name) == 0) {
 			return &serializers[i];
@@ -177,8 +192,8 @@ void send_write(struct packet *packet) {
 			}
 			if (write(iter->peer.fd, buf_at(&buf, 0), buf.length) != (ssize_t) buf.length) {
 				// peer_loop() will see this shutdown and call send_del
-				int res = shutdown(iter->peer.fd, SHUT_WR);
-				assert(res == 0 || (res == -1 && errno == ENOTSOCK));
+				// Ignore error
+				shutdown(iter->peer.fd, SHUT_WR);
 			}
 		}
 	}
@@ -190,3 +205,11 @@ void send_print_usage() {
 		fprintf(stderr, "\t%s\n", serializers[i].name);
 	}
 }
+
+bool send_add(bool (*next)(const char *, struct flow *, void *), struct flow *flow, const char *arg) {
+	struct serializer *serializer = send_parse_format(&arg);
+	if (!serializer) {
+		return false;
+	}
+	return next(arg, flow, serializer);
+}
diff --git a/adsbus/send.h b/adsbus/send.h
index a3c380f..31d6752 100644
--- a/adsbus/send.h
+++ b/adsbus/send.h
@@ -1,13 +1,16 @@
 #pragma once
 
+#include <stdbool.h>
+
 struct buf;
 struct flow;
 struct packet;
 
 void send_init(void);
 void send_cleanup(void);
-void *send_get_serializer(char *);
+void *send_get_serializer(const char *);
 void send_get_hello(struct buf **, void *);
 void send_write(struct packet *);
 void send_print_usage(void);
+bool send_add(bool (*)(const char *, struct flow *, void *), struct flow *, const char *);
 extern struct flow *send_flow;
diff --git a/adsbus/send_receive.c b/adsbus/send_receive.c
index 0285cf2..6e72b23 100644
--- a/adsbus/send_receive.c
+++ b/adsbus/send_receive.c
@@ -1,10 +1,8 @@
 #include <assert.h>
 #include <fcntl.h>
 #include <stdlib.h>
-#include <unistd.h>
 
 #include "flow.h"
-#include "list.h"
 #include "peer.h"
 #include "receive.h"
 #include "send.h"
@@ -37,7 +35,7 @@ static void send_receive_del(struct send_receive *send_receive) {
 }
 
 static void send_receive_on_close(struct peer *peer) {
-	struct send_receive *send_receive = (struct send_receive *) peer;
+	struct send_receive *send_receive = container_of(peer, struct send_receive, peer);
 
 	if (!--(send_receive->ref_count)) {
 		send_receive_del(send_receive);
@@ -54,10 +52,10 @@ static void send_receive_new(int fd, void *passthrough, struct peer *on_close) {
 	send_receive->ref_count = 2;
 	list_add(&send_receive->send_receive_list, &send_receive_head);
 
-	flow_new(fd, send_flow, passthrough, on_close);
+	flow_new(fd, send_flow, passthrough, &send_receive->peer);
 	int fd2 = fcntl(fd, F_DUPFD_CLOEXEC, 0);
 	assert(fd2 >= 0);
-	flow_new(fd2, receive_flow, NULL, on_close);
+	flow_new(fd2, receive_flow, NULL, &send_receive->peer);
 }
 
 void send_receive_cleanup() {
diff --git a/adsbus/server.c b/adsbus/server.c
index 288996f..4978c39 100644
--- a/adsbus/server.c
+++ b/adsbus/server.c
@@ -1,13 +1,85 @@
+#include <assert.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <unistd.h>
 
+#include <jansson.h>
+#include <protobuf-c/protobuf-c.h>
+
+#include "build.h"
+#include "log.h"
+#include "opts.h"
 #include "uuid.h"
 
 #include "server.h"
 
+#pragma GCC diagnostic ignored "-Wdate-time"
+
 uint8_t server_id[UUID_LEN];
 char server_version[] = "https://github.com/flamingcowtv/adsb-tools#1";
+static opts_group server_opts1, server_opts2;
+
+static char log_module = 'X';
+
+static bool server_detach(const char __attribute__ ((unused)) *arg) {
+	LOG(server_id, "Detaching");
+
+	int ret = fork();
+	assert(ret >= 0);
+	if (ret > 0) {
+		// We are the parent
+		exit(EXIT_SUCCESS);
+	}
+
+	LOG(server_id, "Background process ID: %u", getpid());
+
+	assert(setsid() >= 0);
+
+	return true;
+}
+
+static bool server_pid_file(const char *path) {
+	pid_t pid = getpid();
+	LOG(server_id, "Writing process ID %d to pid-file: %s", pid, path);
+	FILE *fh = fopen(path, "w");
+	assert(fh);
+	assert(fprintf(fh, "%d\n", pid) > 0);
+	assert(!fclose(fh));
+	return true;
+}
+
+void server_opts_add() {
+	opts_add("detach", NULL, server_detach, server_opts1);
+	opts_add("pid-file", "PATH", server_pid_file, server_opts2);
+}
 
 void server_init() {
 	uuid_gen(server_id);
-	fprintf(stderr, "X %s: Server start\n", server_id);
+	LOG(server_id, "Server start");
+	LOG(server_id, "Build data:");
+	LOG(server_id, "\tgit_last_change: %s", GIT_LAST_CHANGE);
+	LOG(server_id, "\tgit_local_clean: %s", GIT_LOCAL_CLEAN ? "true" : "false");
+	LOG(server_id, "\tclang_version: %s", __clang_version__);
+	LOG(server_id, "\tglibc_version: %d.%d", __GLIBC__, __GLIBC_MINOR__);
+	LOG(server_id, "\tjansson_version: %s", JANSSON_VERSION);
+	LOG(server_id, "\tprotobuf-c_version: %s", PROTOBUF_C_VERSION);
+	LOG(server_id, "\tdatetime: %s", __DATE__ " " __TIME__);
+	LOG(server_id, "\tusername: %s", USERNAME);
+	LOG(server_id, "\thostname: %s", HOSTNAME);
+
+	LOG(server_id, "Runtime data:");
+	struct utsname utsname;
+	assert(!uname(&utsname));
+	LOG(server_id, "\tusername: %s", getlogin());
+	LOG(server_id, "\thostname: %s", utsname.nodename);
+	LOG(server_id, "\tprocess_id: %d", getpid());
+	LOG(server_id, "\tsystem: %s", utsname.sysname);
+	LOG(server_id, "\trelease: %s", utsname.release);
+	LOG(server_id, "\tversion: %s", utsname.version);
+	LOG(server_id, "\tmachine: %s", utsname.machine);
+
+	opts_call(server_opts1);
+	opts_call(server_opts2);
 }
diff --git a/adsbus/server.h b/adsbus/server.h
index b5fcfc8..8e9e889 100644
--- a/adsbus/server.h
+++ b/adsbus/server.h
@@ -3,4 +3,5 @@
 extern uint8_t server_id[];
 extern char server_version[];
 
+void server_opts_add(void);
 void server_init(void);
diff --git a/adsbus/socket.c b/adsbus/socket.c
index 207460e..7782ded 100644
--- a/adsbus/socket.c
+++ b/adsbus/socket.c
@@ -2,8 +2,9 @@
 #include <errno.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
-#include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #include "socket.h"
 
diff --git a/adsbus/stdinout.c b/adsbus/stdinout.c
new file mode 100644
index 0000000..c1c7f38
--- /dev/null
+++ b/adsbus/stdinout.c
@@ -0,0 +1,37 @@
+#include <assert.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "flow.h"
+#include "opts.h"
+#include "receive.h"
+#include "send.h"
+
+#include "stdinout.h"
+
+static opts_group stdinout_opts;
+
+static bool stdinout_stdin(const char __attribute__((unused)) *arg) {
+	int fd = fcntl(STDIN_FILENO, F_DUPFD_CLOEXEC, 0);
+	assert(fd >= 0);
+	return flow_new_send_hello(fd, receive_flow, NULL, NULL);
+}
+
+static bool stdinout_stdout(const char *arg) {
+	struct serializer *serializer = send_get_serializer(arg);
+	if (!serializer) {
+		return false;
+	}
+	int fd = fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
+	assert(fd >= 0);
+	return flow_new_send_hello(fd, send_flow, serializer, NULL);
+}
+
+void stdinout_opts_add() {
+	opts_add("stdin", NULL, stdinout_stdin, stdinout_opts);
+	opts_add("stdout", "FORMAT", stdinout_stdout, stdinout_opts);
+}
+
+void stdinout_init() {
+	opts_call(stdinout_opts);
+}
diff --git a/adsbus/stdinout.h b/adsbus/stdinout.h
new file mode 100644
index 0000000..e1291f4
--- /dev/null
+++ b/adsbus/stdinout.h
@@ -0,0 +1,4 @@
+#pragma once
+
+void stdinout_opts_add(void);
+void stdinout_init(void);
diff --git a/adsbus/uuid.c b/adsbus/uuid.c
index 792bf49..b5c0bca 100644
--- a/adsbus/uuid.c
+++ b/adsbus/uuid.c
@@ -1,5 +1,3 @@
-#include <stdint.h>
-
 #include "hex.h"
 #include "rand.h"
 
diff --git a/adsbus/wakeup.c b/adsbus/wakeup.c
index ed89abd..1dfb5b9 100644
--- a/adsbus/wakeup.c
+++ b/adsbus/wakeup.c
@@ -1,91 +1,72 @@
 #include <assert.h>
-#include <fcntl.h>
-#include <errno.h>
-#include <limits.h>
 #include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <string.h>
-#include <sys/epoll.h>
-#include <time.h>
+#include <sys/timerfd.h>
 #include <unistd.h>
 
-#include "list.h"
 #include "peer.h"
 #include "rand.h"
 
 #include "wakeup.h"
 
-struct wakeup_entry {
-	int fd;
-	uint64_t absolute_time_ms;
-	struct peer *peer;
+struct wakeup {
+	struct peer peer;
+	struct peer *inner_peer;
 	struct list_head wakeup_list;
 };
 
 static struct list_head wakeup_head = LIST_HEAD_INIT(wakeup_head);
 
-static uint64_t wakeup_get_time_ms() {
-	struct timespec tp;
-	assert(!clock_gettime(CLOCK_MONOTONIC_COARSE, &tp));
-#define MS_PER_S UINT64_C(1000)
-#define NS_PER_MS UINT64_C(1000000)
-	assert(tp.tv_sec >= 0);
-	assert(tp.tv_nsec >= 0);
-	return ((uint64_t) tp.tv_sec * MS_PER_S) + ((uint64_t) tp.tv_nsec / NS_PER_MS);
+static void wakeup_del(struct wakeup *wakeup) {
+	peer_close(&wakeup->peer);
+	list_del(&wakeup->wakeup_list);
+	free(wakeup);
+}
+
+static void wakeup_handler(struct peer *peer) {
+	struct wakeup *wakeup = container_of(peer, struct wakeup, peer);
+
+	uint64_t events;
+	assert(read(wakeup->peer.fd, &events, sizeof(events)) == sizeof(events));
+	assert(events == 1);
+
+	peer_call(wakeup->inner_peer);
+	wakeup_del(wakeup);
 }
 
 void wakeup_init() {
 }
 
 void wakeup_cleanup() {
-	struct wakeup_entry *iter, *next;
+	struct wakeup *iter, *next;
 	list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
-		free(iter);
-	}
-}
-
-int wakeup_get_delay() {
-	if (list_is_empty(&wakeup_head)) {
-		return -1;
-	}
-	uint64_t now = wakeup_get_time_ms();
-	struct wakeup_entry *next_to_fire = list_entry(wakeup_head.next, struct wakeup_entry, wakeup_list);
-	if (next_to_fire->absolute_time_ms > now) {
-		uint64_t delta = next_to_fire->absolute_time_ms - now;
-		assert(delta < INT_MAX);
-		return (int) delta;
-	} else {
-		return 0;
-	}
-}
-
-void wakeup_dispatch() {
-	uint64_t now = wakeup_get_time_ms();
-	struct wakeup_entry *iter, *next;
-	list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
-		if (iter->absolute_time_ms > now) {
-			break;
-		}
-		peer_call(iter->peer);
-		list_del(&iter->wakeup_list);
-		free(iter);
+		wakeup_del(iter);
 	}
 }
 
 void wakeup_add(struct peer *peer, uint32_t delay_ms) {
-	struct wakeup_entry *entry = malloc(sizeof(*entry));
-	entry->absolute_time_ms = wakeup_get_time_ms() + delay_ms;
-	entry->peer = peer;
+	struct wakeup *wakeup = malloc(sizeof(*wakeup));
+	wakeup->inner_peer = peer;
+	list_add(&wakeup->wakeup_list, &wakeup_head);
 
-	struct wakeup_entry *iter, *next;
-	list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
-		if (iter->absolute_time_ms > entry->absolute_time_ms) {
-			list_add(&entry->wakeup_list, &iter->wakeup_list);
-			return;
-		}
-	}
-	list_add(&entry->wakeup_list, &wakeup_head);
+	wakeup->peer.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
+	assert(wakeup->peer.fd >= 0);
+
+#define MS_PER_S UINT64_C(1000)
+#define NS_PER_MS UINT64_C(1000000)
+	const struct itimerspec ts = {
+		.it_interval = {
+			.tv_sec = 0,
+			.tv_nsec = 0,
+		},
+		.it_value = {
+			.tv_sec = delay_ms / MS_PER_S,
+			.tv_nsec = (delay_ms % MS_PER_S) * NS_PER_MS,
+		},
+	};
+	assert(!timerfd_settime(wakeup->peer.fd, 0, &ts, NULL));
+
+	wakeup->peer.event_handler = wakeup_handler;
+	peer_epoll_add(&wakeup->peer, EPOLLIN);
 }
 
 #define RETRY_MIN_MS 2000
diff --git a/adsbus/wakeup.h b/adsbus/wakeup.h
index 77ffb3b..c11f7e3 100644
--- a/adsbus/wakeup.h
+++ b/adsbus/wakeup.h
@@ -6,7 +6,5 @@ struct peer;
 
 void wakeup_init(void);
 void wakeup_cleanup(void);
-int wakeup_get_delay(void);
-void wakeup_dispatch(void);
 void wakeup_add(struct peer *, uint32_t);
 uint32_t wakeup_get_retry_delay_ms(uint32_t);