#include <linux/module.h>
#include <net/tcp.h>
-int sysctl_tcp_syn_retries = TCP_SYN_RETRIES;
-int sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES;
-int sysctl_tcp_keepalive_time = TCP_KEEPALIVE_TIME;
-int sysctl_tcp_keepalive_probes = TCP_KEEPALIVE_PROBES;
-int sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL;
-int sysctl_tcp_retries1 = TCP_RETR1;
-int sysctl_tcp_retries2 = TCP_RETR2;
-int sysctl_tcp_orphan_retries;
+int sysctl_tcp_syn_retries __read_mostly = TCP_SYN_RETRIES;
+int sysctl_tcp_synack_retries __read_mostly = TCP_SYNACK_RETRIES;
+int sysctl_tcp_keepalive_time __read_mostly = TCP_KEEPALIVE_TIME;
+int sysctl_tcp_keepalive_probes __read_mostly = TCP_KEEPALIVE_PROBES;
+int sysctl_tcp_keepalive_intvl __read_mostly = TCP_KEEPALIVE_INTVL;
+int sysctl_tcp_retries1 __read_mostly = TCP_RETR1;
+int sysctl_tcp_retries2 __read_mostly = TCP_RETR2;
+int sysctl_tcp_orphan_retries __read_mostly;
static void tcp_write_timer(unsigned long);
static void tcp_delack_timer(unsigned long);
* to prevent DoS attacks. It is called when a retransmission timeout
* or zero probe timeout occurs on orphaned socket.
*
- * Criterium is still not confirmed experimentally and may change.
+ * Criteria is still not confirmed experimentally and may change.
* We kill the socket, if:
* 1. If number of orphaned sockets exceeds an administratively configured
* limit.
/* A write timeout has occurred. Process the after effects. */
static int tcp_write_timeout(struct sock *sk)
{
- const struct inet_connection_sock *icsk = inet_csk(sk);
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
int retry_until;
+ int mss;
if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
if (icsk->icsk_retransmits)
retry_until = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
} else {
if (icsk->icsk_retransmits >= sysctl_tcp_retries1) {
- /* NOTE. draft-ietf-tcpimpl-pmtud-01.txt requires pmtu black
- hole detection. :-(
-
- It is place to make it. It is not made. I do not want
- to make it. It is disguisting. It does not work in any
- case. Let me to cite the same draft, which requires for
- us to implement this:
-
- "The one security concern raised by this memo is that ICMP black holes
- are often caused by over-zealous security administrators who block
- all ICMP messages. It is vitally important that those who design and
- deploy security systems understand the impact of strict filtering on
- upper-layer protocols. The safest web site in the world is worthless
- if most TCP implementations cannot transfer data from it. It would
- be far nicer to have all of the black holes fixed rather than fixing
- all of the TCP implementations."
-
- Golden words :-).
- */
+ /* Black hole detection */
+ if (sysctl_tcp_mtu_probing) {
+ if (!icsk->icsk_mtup.enabled) {
+ icsk->icsk_mtup.enabled = 1;
+ tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+ } else {
+ mss = min(sysctl_tcp_base_mss,
+ tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low)/2);
+ mss = max(mss, 68 - tp->tcp_header_len);
+ icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss);
+ tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+ }
+ }
dst_negative_advice(&sk->sk_dst_cache);
}
static void tcp_probe_timer(struct sock *sk)
{
+ struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
int max_probes;
if (tp->packets_out || !sk->sk_send_head) {
- tp->probes_out = 0;
+ icsk->icsk_probes_out = 0;
return;
}
* FIXME: We ought not to do it, Solaris 2.5 actually has fixing
* this behaviour in Solaris down as a bug fix. [AC]
*
- * Let me to explain. probes_out is zeroed by incoming ACKs
+ * Let me to explain. icsk_probes_out is zeroed by incoming ACKs
* even if they advertise zero window. Hence, connection is killed only
* if we received no ACKs for normal connection timeout. It is not killed
* only because window stays zero for some time, window may be zero
max_probes = sysctl_tcp_retries2;
if (sock_flag(sk, SOCK_DEAD)) {
- const struct inet_connection_sock *icsk = inet_csk(sk);
const int alive = ((icsk->icsk_rto << icsk->icsk_backoff) < TCP_RTO_MAX);
max_probes = tcp_orphan_retries(sk, alive);
- if (tcp_out_of_resources(sk, alive || tp->probes_out <= max_probes))
+ if (tcp_out_of_resources(sk, alive || icsk->icsk_probes_out <= max_probes))
return;
}
- if (tp->probes_out > max_probes) {
+ if (icsk->icsk_probes_out > max_probes) {
tcp_write_err(sk);
} else {
/* Only send another probe if we didn't close things up. */
goto out;
if (icsk->icsk_retransmits == 0) {
- if (tp->ca_state == TCP_CA_Disorder || tp->ca_state == TCP_CA_Recovery) {
+ if (icsk->icsk_ca_state == TCP_CA_Disorder ||
+ icsk->icsk_ca_state == TCP_CA_Recovery) {
if (tp->rx_opt.sack_ok) {
- if (tp->ca_state == TCP_CA_Recovery)
+ if (icsk->icsk_ca_state == TCP_CA_Recovery)
NET_INC_STATS_BH(LINUX_MIB_TCPSACKRECOVERYFAIL);
else
NET_INC_STATS_BH(LINUX_MIB_TCPSACKFAILURES);
} else {
- if (tp->ca_state == TCP_CA_Recovery)
+ if (icsk->icsk_ca_state == TCP_CA_Recovery)
NET_INC_STATS_BH(LINUX_MIB_TCPRENORECOVERYFAIL);
else
NET_INC_STATS_BH(LINUX_MIB_TCPRENOFAILURES);
}
- } else if (tp->ca_state == TCP_CA_Loss) {
+ } else if (icsk->icsk_ca_state == TCP_CA_Loss) {
NET_INC_STATS_BH(LINUX_MIB_TCPLOSSFAILURES);
} else {
NET_INC_STATS_BH(LINUX_MIB_TCPTIMEOUTS);
static void tcp_keepalive_timer (unsigned long data)
{
struct sock *sk = (struct sock *) data;
+ struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
__u32 elapsed;
elapsed = tcp_time_stamp - tp->rcv_tstamp;
if (elapsed >= keepalive_time_when(tp)) {
- if ((!tp->keepalive_probes && tp->probes_out >= sysctl_tcp_keepalive_probes) ||
- (tp->keepalive_probes && tp->probes_out >= tp->keepalive_probes)) {
+ if ((!tp->keepalive_probes && icsk->icsk_probes_out >= sysctl_tcp_keepalive_probes) ||
+ (tp->keepalive_probes && icsk->icsk_probes_out >= tp->keepalive_probes)) {
tcp_send_active_reset(sk, GFP_ATOMIC);
tcp_write_err(sk);
goto out;
}
if (tcp_write_wakeup(sk) <= 0) {
- tp->probes_out++;
+ icsk->icsk_probes_out++;
elapsed = keepalive_intvl_when(tp);
} else {
/* If keepalive was lost due to local congestion,
projects / linux-2.6 / blobdiff