#define FIN 4
#define RST 8
+#define AUX_INIT 1
+#define AUX_FRAME 2
+#define AUX_SAK 3
+#define AUX_TIMESTAMP 4
+
+#define NSACKS 4
#define DEFAULT_SNDBUFSIZE 4096
#define DEFAULT_MAXSNDBUFSIZE 131072
+#define DEFAULT_RCVBUFSIZE 0
+#define DEFAULT_MAXRCVBUFSIZE 131072
+
+#define DEFAULT_MTU 1000
+
+#define USEC_PER_SEC 1000000
+#define DEFAULT_USER_TIMEOUT 60 // sec
+#define CLOCK_GRANULARITY 1000 // usec
+#define START_RTO 1000000 // usec
+#define MAX_RTO 3000000 // usec
struct hdr {
uint16_t src; // Source port
TIME_WAIT
};
-static const char *strstate[] = {
+static const char *strstate[] __attribute__((unused)) = {
[CLOSED] = "CLOSED",
[LISTEN] = "LISTEN",
[SYN_SENT] = "SYN_SENT",
[TIME_WAIT] = "TIME_WAIT"
};
+struct buffer {
+ char *data;
+ uint32_t used;
+ uint32_t size;
+ uint32_t maxsize;
+};
+
+struct sack {
+ uint32_t offset;
+ uint32_t len;
+};
+
struct utcp_connection {
void *priv;
struct utcp *utcp;
+ uint32_t flags;
+
bool reapable;
- bool nodelay;
- bool keepalive;
+ // Callbacks
+
+ utcp_recv_t recv;
+ utcp_poll_t poll;
+
+ // TCP State
uint16_t src;
uint16_t dst;
enum state state;
- // The following two structures form the TCB
-
struct {
uint32_t una;
uint32_t nxt;
uint32_t wnd;
uint32_t iss;
+
+ uint32_t last;
+ uint32_t cwnd;
+ uint32_t ssthresh;
} snd;
struct {
uint32_t nxt;
- uint32_t wnd;
uint32_t irs;
} rcv;
- utcp_recv_t recv;
+ int dupack;
+
+ // Timers
struct timeval conn_timeout;
struct timeval rtrx_timeout;
+ struct timeval rtt_start;
+ uint32_t rtt_seq;
+
+ // Buffers
- char *sndbuf;
- uint32_t sndbufsize;
- uint32_t maxsndbufsize;
+ struct buffer sndbuf;
+ struct buffer rcvbuf;
+ struct sack sacks[NSACKS];
+
+ // Per-socket options
+
+ bool nodelay;
+ bool keepalive;
+ bool shut_wr;
+
+ // Congestion avoidance state
+
+ struct timeval tlast;
+ uint64_t bandwidth;
};
struct utcp {
void *priv;
+ // Callbacks
+
utcp_accept_t accept;
utcp_pre_accept_t pre_accept;
utcp_send_t send;
+ // Global socket options
+
uint16_t mtu;
- int timeout;
+ int timeout; // sec
+
+ // RTT variables
+
+ uint32_t srtt; // usec
+ uint32_t rttvar; // usec
+ uint32_t rto; // usec
+
+ // Connection management
struct utcp_connection **connections;
int nconnections;