diff options
| author | Markus Friedl <markus@cvs.openbsd.org> | 2005-06-30 08:51:32 +0000 |
|---|---|---|
| committer | Markus Friedl <markus@cvs.openbsd.org> | 2005-06-30 08:51:32 +0000 |
| commit | d0da6045c3473c63c2c5ebcb604695383312ac92 (patch) | |
| tree | 47b24d0d2ccf633ec13c5ec6181e8098952eea3e /sys/netinet/tcp_var.h | |
| parent | 9a113f7cb87a9e2074ec670f5a343663a903c767 (diff) | |
implement PMTU checks from
http://www.gont.com.ar/drafts/icmp-attacks-against-tcp.html
i.e. don't act on ICMP-need-frag immediately if adhoc checks on the
advertised mtu fail. the mtu update is delayed until a tcp retransmit
happens. initial patch by Fernando Gont, tested by many.
Diffstat (limited to 'sys/netinet/tcp_var.h')
| -rw-r--r-- | sys/netinet/tcp_var.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h index 04334ea17e6..5b7d67b7941 100644 --- a/sys/netinet/tcp_var.h +++ b/sys/netinet/tcp_var.h @@ -1,4 +1,4 @@ -/* $OpenBSD: tcp_var.h,v 1.74 2005/05/24 00:02:37 fgont Exp $ */ +/* $OpenBSD: tcp_var.h,v 1.75 2005/06/30 08:51:31 markus Exp $ */ /* $NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $ */ /* @@ -85,6 +85,7 @@ struct tcpcb { #define TF_REASSLOCK 0x00080000 /* reassembling or draining */ #define TF_LASTIDLE 0x00100000 /* no outstanding ACK on last send */ #define TF_DEAD 0x00200000 /* dead and to-be-released */ +#define TF_PMTUD_PEND 0x00400000 /* Path MTU Discovery pending */ struct mbuf *t_template; /* skeletal packet for transmit */ struct inpcb *t_inpcb; /* back pointer to internet pcb */ @@ -179,6 +180,14 @@ struct tcpcb { /* TUBA stuff */ caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */ +/* Path-MTU Discovery Information */ + u_int t_pmtud_mss_acked; /* MSS acked, lower bound for MTU */ + u_int t_pmtud_mtu_sent; /* MTU used, upper bound for MTU */ + tcp_seq t_pmtud_th_seq; /* TCP SEQ from ICMP payload */ + u_int t_pmtud_nextmtu; /* Advertised Next-Hop MTU from ICMP */ + u_short t_pmtud_ip_len; /* IP length from ICMP payload */ + u_short t_pmtud_ip_hl; /* IP header length from ICMP payload */ + int pf; struct timeout t_reap_to; /* delayed cleanup timeout */ @@ -582,6 +591,7 @@ int tcp6_input(struct mbuf **, int *, int); void tcp_input(struct mbuf *, ...); int tcp_mss(struct tcpcb *, int); void tcp_mss_update(struct tcpcb *); +u_int tcp_hdrsz(struct tcpcb *); void tcp_mtudisc(struct inpcb *, int); void tcp_mtudisc_increase(struct inpcb *, int); #ifdef INET6 |