sysctl net: Keep tcp_syn_retries inside the boundary

[ Upstream commit 651e92716aaae60fc41b9652f54cb6803896e0da ]

Limit the min/max value passed to the
/proc/sys/net/ipv4/tcp_syn_retries.

Signed-off-by: Michal Tesar <mtesar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 5485077..739b073 100644 (file)
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -32,6 +32,8 @@ static int tcp_adv_win_scale_min = -31;
 static int tcp_adv_win_scale_max = 31;
 static int ip_ttl_min = 1;
 static int ip_ttl_max = 255;
 static int tcp_adv_win_scale_max = 31;
 static int ip_ttl_min = 1;
 static int ip_ttl_max = 255;

+static int tcp_syn_retries_min = 1;
+static int tcp_syn_retries_max = MAX_TCP_SYNCNT;

 static int ip_ping_group_range_min[] = { 0, 0 };
 static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
 
 static int ip_ping_group_range_min[] = { 0, 0 };
 static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
 


@@ -231,7 +233,9 @@ static struct ctl_table ipv4_table[] = {
                .data           = &sysctl_tcp_syn_retries,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .data           = &sysctl_tcp_syn_retries,
                .maxlen         = sizeof(int),
                .mode           = 0644,

-               .proc_handler   = proc_dointvec
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &tcp_syn_retries_min,
+               .extra2         = &tcp_syn_retries_max

        },
        {
                .procname       = "tcp_synack_retries",
        },
        {
                .procname       = "tcp_synack_retries",