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Diffstat (limited to 'sys/netinet/tcp_input.c')
-rw-r--r--sys/netinet/tcp_input.c106
1 files changed, 94 insertions, 12 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 140cee7..a763e46 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -98,6 +98,9 @@ __FBSDID("$FreeBSD$");
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
+#ifdef TCP_RFC7413
+#include <netinet/tcp_fastopen.h>
+#endif
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
@@ -916,9 +919,10 @@ findpcb:
*/
if (inp->inp_ip_minttl != 0) {
#ifdef INET6
- if (isipv6 && inp->inp_ip_minttl > ip6->ip6_hlim)
- goto dropunlock;
- else
+ if (isipv6) {
+ if (inp->inp_ip_minttl > ip6->ip6_hlim)
+ goto dropunlock;
+ } else
#endif
if (inp->inp_ip_minttl > ip->ip_ttl)
goto dropunlock;
@@ -999,7 +1003,8 @@ relocked:
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
#endif
if (!((tp->t_state == TCPS_ESTABLISHED && (thflags & TH_SYN) == 0) ||
- (tp->t_state == TCPS_LISTEN && (thflags & TH_SYN)))) {
+ (tp->t_state == TCPS_LISTEN && (thflags & TH_SYN) &&
+ !(tp->t_flags & TF_FASTOPEN)))) {
if (ti_locked == TI_UNLOCKED) {
if (INP_INFO_TRY_RLOCK(&V_tcbinfo) == 0) {
in_pcbref(inp);
@@ -1091,6 +1096,9 @@ relocked:
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
+#ifdef TCP_RFC7413
+new_tfo_socket:
+#endif
if (so == NULL) {
/*
* We completed the 3-way handshake
@@ -1353,7 +1361,12 @@ relocked:
#endif
TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
tcp_dooptions(&to, optp, optlen, TO_SYN);
+#ifdef TCP_RFC7413
+ if (syncache_add(&inc, &to, th, inp, &so, m, NULL, NULL))
+ goto new_tfo_socket;
+#else
syncache_add(&inc, &to, th, inp, &so, m, NULL, NULL);
+#endif
/*
* Entry added to syncache and mbuf consumed.
* Only the listen socket is unlocked by syncache_add().
@@ -1468,7 +1481,8 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct in_conninfo *inc;
struct mbuf *mfree;
struct tcpopt to;
-
+ int tfo_syn;
+
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
@@ -1921,6 +1935,28 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
+#ifdef TCP_RFC7413
+ if (tp->t_flags & TF_FASTOPEN) {
+ /*
+ * When a TFO connection is in SYN_RECEIVED, the
+ * only valid packets are the initial SYN, a
+ * retransmit/copy of the initial SYN (possibly with
+ * a subset of the original data), a valid ACK, a
+ * FIN, or a RST.
+ */
+ if ((thflags & (TH_SYN|TH_ACK)) == (TH_SYN|TH_ACK)) {
+ rstreason = BANDLIM_RST_OPENPORT;
+ goto dropwithreset;
+ } else if (thflags & TH_SYN) {
+ /* non-initial SYN is ignored */
+ if ((tcp_timer_active(tp, TT_DELACK) ||
+ tcp_timer_active(tp, TT_REXMT)))
+ goto drop;
+ } else if (!(thflags & (TH_ACK|TH_FIN|TH_RST))) {
+ goto drop;
+ }
+ }
+#endif
break;
/*
@@ -2136,7 +2172,8 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
* RFC5961 Section 4.2
* Send challenge ACK for any SYN in synchronized state.
*/
- if ((thflags & TH_SYN) && tp->t_state != TCPS_SYN_SENT) {
+ if ((thflags & TH_SYN) && tp->t_state != TCPS_SYN_SENT &&
+ tp->t_state != TCPS_SYN_RECEIVED) {
KASSERT(ti_locked == TI_RLOCKED,
("tcp_do_segment: TH_SYN ti_locked %d", ti_locked));
INP_INFO_RLOCK_ASSERT(&V_tcbinfo);
@@ -2330,9 +2367,16 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_state == TCPS_SYN_RECEIVED ||
- (tp->t_flags & TF_NEEDSYN))
+ (tp->t_flags & TF_NEEDSYN)) {
+#ifdef TCP_RFC7413
+ if (tp->t_state == TCPS_SYN_RECEIVED &&
+ tp->t_flags & TF_FASTOPEN) {
+ tp->snd_wnd = tiwin;
+ cc_conn_init(tp);
+ }
+#endif
goto step6;
- else if (tp->t_flags & TF_ACKNOW)
+ } else if (tp->t_flags & TF_ACKNOW)
goto dropafterack;
else
goto drop;
@@ -2371,7 +2415,27 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
tcp_state_change(tp, TCPS_ESTABLISHED);
TCP_PROBE5(accept__established, NULL, tp,
mtod(m, const char *), tp, th);
- cc_conn_init(tp);
+#ifdef TCP_RFC7413
+ if (tp->t_tfo_pending) {
+ tcp_fastopen_decrement_counter(tp->t_tfo_pending);
+ tp->t_tfo_pending = NULL;
+
+ /*
+ * Account for the ACK of our SYN prior to
+ * regular ACK processing below.
+ */
+ tp->snd_una++;
+ }
+ /*
+ * TFO connections call cc_conn_init() during SYN
+ * processing. Calling it again here for such
+ * connections is not harmless as it would undo the
+ * snd_cwnd reduction that occurs when a TFO SYN|ACK
+ * is retransmitted.
+ */
+ if (!(tp->t_flags & TF_FASTOPEN))
+#endif
+ cc_conn_init(tp);
tcp_timer_activate(tp, TT_KEEP, TP_KEEPIDLE(tp));
}
/*
@@ -2919,7 +2983,9 @@ dodata: /* XXX */
* case PRU_RCVD). If a FIN has already been received on this
* connection then we just ignore the text.
*/
- if ((tlen || (thflags & TH_FIN)) &&
+ tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
+ (tp->t_flags & TF_FASTOPEN));
+ if ((tlen || (thflags & TH_FIN) || tfo_syn) &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
tcp_seq save_start = th->th_seq;
m_adj(m, drop_hdrlen); /* delayed header drop */
@@ -2937,8 +3003,9 @@ dodata: /* XXX */
*/
if (th->th_seq == tp->rcv_nxt &&
LIST_EMPTY(&tp->t_segq) &&
- TCPS_HAVEESTABLISHED(tp->t_state)) {
- if (DELAY_ACK(tp, tlen))
+ (TCPS_HAVEESTABLISHED(tp->t_state) ||
+ tfo_syn)) {
+ if (DELAY_ACK(tp, tlen) || tfo_syn)
tp->t_flags |= TF_DELACK;
else
tp->t_flags |= TF_ACKNOW;
@@ -3293,6 +3360,21 @@ tcp_dooptions(struct tcpopt *to, u_char *cp, int cnt, int flags)
to->to_sacks = cp + 2;
TCPSTAT_INC(tcps_sack_rcv_blocks);
break;
+#ifdef TCP_RFC7413
+ case TCPOPT_FAST_OPEN:
+ if ((optlen != TCPOLEN_FAST_OPEN_EMPTY) &&
+ (optlen < TCPOLEN_FAST_OPEN_MIN) &&
+ (optlen > TCPOLEN_FAST_OPEN_MAX))
+ continue;
+ if (!(flags & TO_SYN))
+ continue;
+ if (!V_tcp_fastopen_enabled)
+ continue;
+ to->to_flags |= TOF_FASTOPEN;
+ to->to_tfo_len = optlen - 2;
+ to->to_tfo_cookie = to->to_tfo_len ? cp + 2 : NULL;
+ break;
+#endif
default:
continue;
}
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