tcp: make sysctl_tcp_ecn namespace aware

As per suggestion from Eric Dumazet this patch makes tcp_ecn sysctl
namespace aware.  The reason behind this patch is to ease the testing
of ecn problems on the internet and allows applications to tune their
own use of ecn.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 2ae2b8372cfdc1a64210218fe3824d7f7973b60c..9b78862014a4c27609236b4ce9f73e69d682e7c7 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -61,6 +61,8 @@ struct netns_ipv4 {
        int sysctl_icmp_ratemask;
        int sysctl_icmp_errors_use_inbound_ifaddr;
 
+       int sysctl_tcp_ecn;
+
        kgid_t sysctl_ping_group_range[2];
        long sysctl_tcp_mem[3];
 

diff --git a/include/net/tcp.h b/include/net/tcp.h
index aed42c7851539ba945c562e7de8692e1201eee7c..614af8b7758e4ac31b4deec6134a9a95759a6533 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -266,7 +266,6 @@ extern int sysctl_tcp_abort_on_overflow;
 extern int sysctl_tcp_max_orphans;
 extern int sysctl_tcp_fack;
 extern int sysctl_tcp_reordering;
-extern int sysctl_tcp_ecn;
 extern int sysctl_tcp_dsack;
 extern int sysctl_tcp_wmem[3];
 extern int sysctl_tcp_rmem[3];
@@ -504,7 +503,8 @@ static inline __u32 cookie_v4_init_sequence(struct sock *sk,
 #endif
 
 extern __u32 cookie_init_timestamp(struct request_sock *req);
-extern bool cookie_check_timestamp(struct tcp_options_received *opt, bool *);
+extern bool cookie_check_timestamp(struct tcp_options_received *opt,
+                               struct net *net, bool *ecn_ok);
 
 /* From net/ipv6/syncookies.c */
 extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);
@@ -728,11 +728,12 @@ struct tcp_skb_cb {
  * notifications, we disable TCP ECN negociation.
  */
 static inline void
-TCP_ECN_create_request(struct request_sock *req, const struct sk_buff *skb)
+TCP_ECN_create_request(struct request_sock *req, const struct sk_buff *skb,
+               struct net *net)
 {
        const struct tcphdr *th = tcp_hdr(skb);
 
-       if (sysctl_tcp_ecn && th->ece && th->cwr &&
+       if (net->ipv4.sysctl_tcp_ecn && th->ece && th->cwr &&
            INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield))
                inet_rsk(req)->ecn_ok = 1;
 }

diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index b236ef04914f99585455269fe2c9a18241088461..ef54377fb11cbdd3f327fa29c45c623923b8cb2f 100644 (file)
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -232,7 +232,8 @@ static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
  *
  * return false if we decode an option that should not be.
  */
-bool cookie_check_timestamp(struct tcp_options_received *tcp_opt, bool *ecn_ok)
+bool cookie_check_timestamp(struct tcp_options_received *tcp_opt,
+                       struct net *net, bool *ecn_ok)
 {
        /* echoed timestamp, lowest bits contain options */
        u32 options = tcp_opt->rcv_tsecr & TSMASK;
@@ -247,7 +248,7 @@ bool cookie_check_timestamp(struct tcp_options_received *tcp_opt, bool *ecn_ok)
 
        tcp_opt->sack_ok = (options & (1 << 4)) ? TCP_SACK_SEEN : 0;
        *ecn_ok = (options >> 5) & 1;
-       if (*ecn_ok && !sysctl_tcp_ecn)
+       if (*ecn_ok && !net->ipv4.sysctl_tcp_ecn)
                return false;
 
        if (tcp_opt->sack_ok && !sysctl_tcp_sack)
@@ -295,7 +296,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
        memset(&tcp_opt, 0, sizeof(tcp_opt));
        tcp_parse_options(skb, &tcp_opt, &hash_location, 0, NULL);
 
-       if (!cookie_check_timestamp(&tcp_opt, &ecn_ok))
+       if (!cookie_check_timestamp(&tcp_opt, sock_net(sk), &ecn_ok))
                goto out;
 
        ret = NULL;

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 7547a6d238a290839bed4ee4e1289586b70831c5..a25e1d286b99eabbff49790b4763a17d869a7c4c 100644 (file)
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -537,13 +537,6 @@ static struct ctl_table ipv4_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
-       {
-               .procname       = "tcp_ecn",
-               .data           = &sysctl_tcp_ecn,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = proc_dointvec
-       },
        {
                .procname       = "tcp_dsack",
                .data           = &sysctl_tcp_dsack,
@@ -849,6 +842,13 @@ static struct ctl_table ipv4_net_table[] = {
                .mode           = 0644,
                .proc_handler   = ipv4_ping_group_range,
        },
+       {
+               .procname       = "tcp_ecn",
+               .data           = &init_net.ipv4.sysctl_tcp_ecn,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec
+       },
        {
                .procname       = "tcp_mem",
                .maxlen         = sizeof(init_net.ipv4.sysctl_tcp_mem),
@@ -882,6 +882,8 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
                        &net->ipv4.sysctl_icmp_ratemask;
                table[6].data =
                        &net->ipv4.sysctl_ping_group_range;
+               table[7].data =
+                       &net->ipv4.sysctl_tcp_ecn;
 
                /* Don't export sysctls to unprivileged users */
                if (net->user_ns != &init_user_ns)

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a28e4db8a952b15cc2f06578f12acbe6353c162a..38e11841be0971b8f6fa8c5d7ca24ec6cf695534 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -81,8 +81,6 @@ int sysctl_tcp_sack __read_mostly = 1;
 int sysctl_tcp_fack __read_mostly = 1;
 int sysctl_tcp_reordering __read_mostly = TCP_FASTRETRANS_THRESH;
 EXPORT_SYMBOL(sysctl_tcp_reordering);
-int sysctl_tcp_ecn __read_mostly = 2;
-EXPORT_SYMBOL(sysctl_tcp_ecn);
 int sysctl_tcp_dsack __read_mostly = 1;
 int sysctl_tcp_app_win __read_mostly = 31;
 int sysctl_tcp_adv_win_scale __read_mostly = 1;

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 54139fa514e6ee2d82c4cf9ca8528e012b546a90..c6ce9ca98d23781e83659de51aecd8808ad4adb3 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1568,7 +1568,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
                goto drop_and_free;
 
        if (!want_cookie || tmp_opt.tstamp_ok)
-               TCP_ECN_create_request(req, skb);
+               TCP_ECN_create_request(req, skb, sock_net(sk));
 
        if (want_cookie) {
                isn = cookie_v4_init_sequence(sk, skb, &req->mss);
@@ -2888,6 +2888,7 @@ EXPORT_SYMBOL(tcp_prot);
 
 static int __net_init tcp_sk_init(struct net *net)
 {
+       net->ipv4.sysctl_tcp_ecn = 2;
        return 0;
 }
 

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 5d451593ef16f98c65379da619b08e3d47236bff..667a6adfccf89629360f824d814e66575c4994b1 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -314,7 +314,7 @@ static inline void TCP_ECN_send_syn(struct sock *sk, struct sk_buff *skb)
        struct tcp_sock *tp = tcp_sk(sk);
 
        tp->ecn_flags = 0;
-       if (sysctl_tcp_ecn == 1) {
+       if (sock_net(sk)->ipv4.sysctl_tcp_ecn == 1) {
                TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_ECE | TCPHDR_CWR;
                tp->ecn_flags = TCP_ECN_OK;
        }

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 40161977f7cf0b69ecc488d87427e03c88d61598..8a0848b60b3539babdf245f4cf256761cfb704cd 100644 (file)
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -179,7 +179,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
        memset(&tcp_opt, 0, sizeof(tcp_opt));
        tcp_parse_options(skb, &tcp_opt, &hash_location, 0, NULL);
 
-       if (!cookie_check_timestamp(&tcp_opt, &ecn_ok))
+       if (!cookie_check_timestamp(&tcp_opt, sock_net(sk), &ecn_ok))
                goto out;
 
        ret = NULL;

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 93825dd3a7c070be4dd1e294a155b409525337e2..3164ad272a74411661930ec19309af14589347c1 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1027,7 +1027,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
        treq->rmt_addr = ipv6_hdr(skb)->saddr;
        treq->loc_addr = ipv6_hdr(skb)->daddr;
        if (!want_cookie || tmp_opt.tstamp_ok)
-               TCP_ECN_create_request(req, skb);
+               TCP_ECN_create_request(req, skb, sock_net(sk));
 
        treq->iif = sk->sk_bound_dev_if;