pnspace.h

#ifndef QUIC_CONN_PNSPACE_H
#define QUIC_CONN_PNSPACE_H
 
#include "common/platform/sys/syscall.h"

typedef enum {
  QUIC_PNS_INITIAL = 0,
  QUIC_PNS_HANDSHAKE,
  QUIC_PNS_APP,
  QUIC_PNS_COUNT
} quic_pns_space;

typedef struct {
  u64 next[QUIC_PNS_COUNT]; 
} quic_pnspace;
 
/* RFC 9000 12.3: 2^62-1 is the highest packet number a sender may ever use;
 * once issued, that space must not send another packet in it (and MUST
 * close the connection without sending a CONNECTION_CLOSE frame). */
#define QUIC_PN_LIMIT (((u64)1 << 62) - 1)
 
/* Initialize all spaces to packet number 0. */
void quic_pnspace_init(quic_pnspace* s);
 
/* Return the next packet number for `space` and advance that space's counter.
 * Each space is strictly monotonic and independent of the others. */
u64 quic_pnspace_next(quic_pnspace* s, quic_pns_space space);
 
/* RFC 9000 12.3: 1 once `space` has issued QUIC_PN_LIMIT (its highest legal
 * packet number), meaning the sender must stop sending in it -- silently,
 * without a CONNECTION_CLOSE. 0 while more packet numbers remain. */
int quic_pnspace_exhausted(const quic_pnspace* s, quic_pns_space space);
 
#endif