-----BEGIN PGP SIGNED MESSAGE-----
I wrote a new sysctl flag allowing to control Time To Live for ICMP packages.
I've applied it to my 2.4.18 and it runs stable on fortress.mirotel.net
(Linux i386).
PS: This is my first kernel patch, so it would be better if community will
forgive me in case i've done something wrong :)
- --- linux/net/ipv4/sysctl_net_ipv4.c Wed Oct 31 01:08:12 2001
+++ linux-2.4.18/net/ipv4/sysctl_net_ipv4.c Mon Jun 10 21:51:08 2002
@@ -22,6 +22,7 @@
extern int sysctl_icmp_echo_ignore_all;
extern int sysctl_icmp_echo_ignore_broadcasts;
extern int sysctl_icmp_ignore_bogus_error_responses;
+extern int sysctl_icmp_default_ttl;
/* From ip_fragment.c */
extern int sysctl_ipfrag_low_thresh;
@@ -176,6 +177,9 @@
{NET_IPV4_ICMP_IGNORE_BOGUS_ERROR_RESPONSES,
"icmp_ignore_bogus_error_responses",
&sysctl_icmp_ignore_bogus_error_responses, sizeof(int), 0644, NULL,
&proc_dointvec},
+ {NET_IPV4_ICMP_DEFAULT_TTL, "icmp_default_ttl",
+ &sysctl_icmp_default_ttl,sizeof(int), 0644,NULL,
+ &proc_dointvec},
{NET_IPV4_ROUTE, "route", NULL, 0, 0555, ipv4_route_table},
#ifdef CONFIG_IP_MULTICAST
{NET_IPV4_IGMP_MAX_MEMBERSHIPS, "igmp_max_memberships",
- --- linux/net/ipv4/ip_output.c Thu Oct 18 00:16:39 2001
+++ linux-2.4.18/net/ipv4/ip_output.c Tue Jun 11 15:58:07 2002
@@ -84,6 +84,9 @@
int sysctl_ip_dynaddr = 0;
int sysctl_ip_default_ttl = IPDEFTTL;
+#ifdef CONFIG_SYSCTL
+extern int sysctl_icmp_default_ttl;
+#endif
/* Generate a checksum for an outgoing IP datagram. */
__inline__ void ip_send_check(struct iphdr *iph)
@@ -572,10 +575,17 @@
*/
mf = htons(IP_MF);
}
- - if (rt->rt_type == RTN_MULTICAST)
- - iph->ttl = sk->protinfo.af_inet.mc_ttl;
- - else
- - iph->ttl = sk->protinfo.af_inet.ttl;
+#ifdef CONFIG_SYSCTL
+ if(sk->protocol != IPPROTO_ICMP) {
+#endif
+ if (rt->rt_type == RTN_MULTICAST)
+ iph->ttl = sk->protinfo.af_inet.mc_ttl;
+ else
+ iph->ttl = sk->protinfo.af_inet.ttl;
+#ifdef CONFIG_SYSCTL
+ }
+ else iph->ttl = sysctl_icmp_default_ttl;
+#endif
iph->protocol = sk->protocol;
iph->check = 0;
iph->saddr = rt->rt_src;
@@ -693,10 +703,19 @@
iph->tos=sk->protinfo.af_inet.tos;
iph->tot_len = htons(length);
iph->frag_off = df;
- - iph->ttl=sk->protinfo.af_inet.mc_ttl;
+ /* set TTL for ICMP packets */
+#ifdef CONFIG_SYSCTL
+ if(iph->protocol == IPPROTO_ICMP)
+ iph->ttl = sysctl_icmp_default_ttl;
+ else {
+#endif
+ if(rt->rt_type != RTN_MULTICAST)
+ iph->ttl = sk->protinfo.af_inet.ttl;
+ else iph->ttl = sk->protinfo.af_inet.mc_ttl;
+#ifdef CONFIG_SYSCTL
+ }
+#endif
ip_select_ident(iph, &rt->u.dst, sk);
- - if (rt->rt_type != RTN_MULTICAST)
- - iph->ttl=sk->protinfo.af_inet.ttl;
iph->protocol=sk->protocol;
iph->saddr=rt->rt_src;
iph->daddr=rt->rt_dst;
- --- linux/net/ipv4/icmp.c Mon Feb 25 21:38:14 2002
+++ linux-2.4.18/net/ipv4/icmp.c Tue Jun 11 15:36:36 2002
@@ -143,6 +143,9 @@
int sysctl_icmp_echo_ignore_all;
int sysctl_icmp_echo_ignore_broadcasts;
+/* Control max icmp ttl. */
+int sysctl_icmp_default_ttl = 255;
+
/* Control parameter - ignore bogus broadcast responses? */
int sysctl_icmp_ignore_bogus_error_responses;
ð
- --
Lev V. Vanyan Software Engineer
Mirotel ISP nic-hdl: VL1580-RIPE, LV2560-NIC
mailto: remedy@mirotel.net
-----BEGIN PGP SIGNATURE-----
Version: 2.6.3a
Charset: noconv
iQB1AwUBPQX8O89Sz223N4s1AQGg9wL+MvqmTeGEo+fPPQO0N9xhuDCskpOypQ/7
AoV7dkqx3IhvYqrZPFUJ2P2KYR1l/whzQK0gmFsWkc0jpPpsfW0Krtmn8JzS4U4h
PQhHhOqhbhWLOEMQoOGhkT/g/mOmAXnE
=d6XJ
-----END PGP SIGNATURE-----
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Jun 15 2002 - 22:00:22 EST