int tcp_reass(struct tcpcb *tp,struct tcpiphdr *ti, usn_mbuf_t *m) { struct tcpiphdr *q; struct usn_socket *so = tp->t_inpcb->inp_socket; int flags; // Call with ti==0 after become established to // force pre-ESTABLISHED data up to user socket. if (ti == 0) goto present; // Find a segment which begins after this one does. for (q = tp->seg_next; q != (struct tcpiphdr *)tp; q = (struct tcpiphdr *)q->ti_next) if (SEQ_GT(q->ti_seq, ti->ti_seq)) break; // If there is a preceding segment, it may provide some of // our data already. If so, drop the data from the incoming // segment. If it provides all of our data, drop us. if ((struct tcpiphdr *)q->ti_prev != (struct tcpiphdr *)tp) { int i; q = (struct tcpiphdr *)q->ti_prev; // conversion to int (in i) handles seq wraparound i = q->ti_seq + q->ti_len - ti->ti_seq; if (i > 0) { if (i >= ti->ti_len) { g_tcpstat.tcps_rcvduppack++; g_tcpstat.tcps_rcvdupbyte += ti->ti_len; usn_free_mbuf(m); return (0); } m_adj(m, i); ti->ti_len -= i; ti->ti_seq += i; } q = (struct tcpiphdr *)(q->ti_next); } g_tcpstat.tcps_rcvoopack++; g_tcpstat.tcps_rcvoobyte += ti->ti_len; REASS_MBUF(ti) = m; // XXX: wrong assumtion dst and src port for mbuf pointer // While we overlap succeeding segments trim them or, // if they are completely covered, dequeue them. while (q != (struct tcpiphdr *)tp) { int i = (ti->ti_seq + ti->ti_len) - q->ti_seq; if (i <= 0) break; if (i < q->ti_len) { q->ti_seq += i; q->ti_len -= i; m_adj(REASS_MBUF(q), i); break; } q = (struct tcpiphdr *)q->ti_next; m = REASS_MBUF((struct tcpiphdr *)q->ti_prev); // FIXME //remque(q->ti_prev); usn_free_mbuf(m); } // FIXME: Stick new segment in its place. //insque(ti, q->ti_prev); present: // Present data to user, advancing rcv_nxt through // completed sequence space. if (TCPS_HAVERCVDSYN(tp->t_state) == 0) return (0); ti = tp->seg_next; if (ti == (struct tcpiphdr *)tp || ti->ti_seq != tp->rcv_nxt) return (0); if (tp->t_state == TCPS_SYN_RECEIVED && ti->ti_len) return (0); do { tp->rcv_nxt += ti->ti_len; flags = ti->ti_flags & TH_FIN; // FIXME //remque(ti); m = REASS_MBUF(ti); ti = (struct tcpiphdr *)ti->ti_next; if (so->so_state & USN_CANTRCVMORE) { usn_free_mbuf(m); } else { sbappend(so->so_rcv, m); } } while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt); sorwakeup(so); usnet_tcpin_rwakeup(so, USN_TCP_IN, USN_TCPEV_READ, m); return (flags); }
int tcp_reass(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m) { register struct tcpiphdr *q; struct socket *so = tp->t_socket; int flags; /* * Call with ti==0 after become established to * force pre-ESTABLISHED data up to user socket. */ if (ti == 0) goto present; /* * Find a segment which begins after this one does. */ for (q = (struct tcpiphdr *)tp->seg_next; q != (struct tcpiphdr *)tp; q = (struct tcpiphdr *)q->ti_next) if (SEQ_GT(q->ti_seq, ti->ti_seq)) break; /* * If there is a preceding segment, it may provide some of * our data already. If so, drop the data from the incoming * segment. If it provides all of our data, drop us. */ if ((struct tcpiphdr *)q->ti_prev != (struct tcpiphdr *)tp) { register int i; q = (struct tcpiphdr *)q->ti_prev; /* conversion to int (in i) handles seq wraparound */ i = q->ti_seq + q->ti_len - ti->ti_seq; if (i > 0) { if (i >= ti->ti_len) { tcpstat.tcps_rcvduppack++; tcpstat.tcps_rcvdupbyte += ti->ti_len; m_freem(m); /* * Try to present any queued data * at the left window edge to the user. * This is needed after the 3-WHS * completes. */ goto present; /* ??? */ } m_adj(m, i); ti->ti_len -= i; ti->ti_seq += i; } q = (struct tcpiphdr *)(q->ti_next); } tcpstat.tcps_rcvoopack++; tcpstat.tcps_rcvoobyte += ti->ti_len; REASS_MBUF(ti) = (mbufp_32) m; /* XXX */ /* * While we overlap succeeding segments trim them or, * if they are completely covered, dequeue them. */ while (q != (struct tcpiphdr *)tp) { register int i = (ti->ti_seq + ti->ti_len) - q->ti_seq; if (i <= 0) break; if (i < q->ti_len) { q->ti_seq += i; q->ti_len -= i; m_adj((struct mbuf *) REASS_MBUF(q), i); break; } q = (struct tcpiphdr *)q->ti_next; m = (struct mbuf *) REASS_MBUF((struct tcpiphdr *)q->ti_prev); slirp_remque((void *)(q->ti_prev)); m_freem(m); } /* * Stick new segment in its place. */ slirp_insque(ti, (void *)(q->ti_prev)); present: /* * Present data to user, advancing rcv_nxt through * completed sequence space. */ if (!TCPS_HAVEESTABLISHED(tp->t_state)) return (0); ti = (struct tcpiphdr *) tp->seg_next; if (ti == (struct tcpiphdr *)tp || ti->ti_seq != tp->rcv_nxt) return (0); if (tp->t_state == TCPS_SYN_RECEIVED && ti->ti_len) return (0); do { tp->rcv_nxt += ti->ti_len; flags = ti->ti_flags & TH_FIN; slirp_remque(ti); m = (struct mbuf *) REASS_MBUF(ti); /* XXX */ ti = (struct tcpiphdr *)ti->ti_next; /* if (so->so_state & SS_FCANTRCVMORE) */ if (so->so_state & SS_FCANTSENDMORE) m_freem(m); else { if (so->so_emu) { if (tcp_emu(so,m)) sbappend(so, m); } else sbappend(so, m); } } while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt); /* sorwakeup(so); */ return (flags); }