Move adsbus into its own dir.

adsbus/common.h

@@ -0,0 +1,94 @@
+#pragma once
+
+#include <stdint.h>
+#include <sys/epoll.h>
+
+
+//////// peer
+
+// All specific peer structs must be castable to this.
+struct peer;
+typedef void (*peer_event_handler)(struct peer *);
+struct peer {
+	int fd;
+	peer_event_handler event_handler;
+};
+extern int epoll_fd;
+void peer_init();
+void peer_epoll_add(struct peer *, uint32_t);
+void peer_epoll_del(struct peer *);
+void peer_loop();
+
+
+//////// buf
+
+#define BUF_LEN_MAX 256
+struct buf {
+	char buf[BUF_LEN_MAX];
+	size_t start;
+	size_t length;
+};
+#define BUF_INIT { \
+	.start = 0, \
+	.length = 0, \
+}
+
+#define buf_chr(buff, at) ((buff)->buf[(buff)->start + (at)])
+#define buf_at(buff, at) (&buf_chr(buff, at))
+
+void buf_init(struct buf *);
+ssize_t buf_fill(struct buf *, int);
+void buf_consume(struct buf *, size_t);
+
+
+//////// packet
+
+#define DATA_LEN_MAX 14
+struct packet {
+	enum {
+		MODE_S_SHORT,
+		MODE_S_LONG,
+	} type;
+	#define NUM_TYPES 2
+	uint8_t payload[DATA_LEN_MAX];
+	uint64_t mlat_timestamp;
+	uint32_t rssi;
+};
+extern char *packet_type_names[];
+
+
+//////// mlat
+
+#define MLAT_MHZ 120
+// Use the signed max to avoid problems with some consumers; it's large enough to not matter.
+#define MLAT_MAX INT64_MAX
+#define RSSI_MAX UINT32_MAX
+
+struct mlat_state {
+	uint64_t timestamp_last;
+	uint64_t timestamp_generation;
+};
+
+uint64_t mlat_timestamp_scale_in(uint64_t, uint64_t, uint16_t, struct mlat_state *);
+uint64_t mlat_timestamp_scale_out(uint64_t, uint64_t, uint16_t);
+
+
+//////// rssi
+
+uint32_t rssi_scale_in(uint32_t, uint32_t);
+uint32_t rssi_scale_out(uint32_t, uint32_t);
+
+
+//////// hex
+
+void hex_init();
+void hex_to_bin(uint8_t *, const char *, size_t);
+uint64_t hex_to_int(const char *, size_t);
+void hex_from_bin(char *, const uint8_t *, size_t);
+void hex_from_int(char *, uint64_t, size_t);
+
+
+///////// uuid
+
+#define UUID_LEN 37
+void uuid_gen(char *);