[Patch 2.4.20+] missing SNMP stats

[Nivedita Singhvi <niv@xxxxxxxxxx>]

Here is the 2.4 version of the patch to support those SNMP TCP
counters currently not supported:

RtoAlgorithm
RtoMin
RtoMax
MaxConn
EstabResets

thanks,
Nivedita



diff -urN linux-2.4.20/include/net/snmp.h linux-2.4.20mibp/include/net/snmp.h
--- linux-2.4.20/include/net/snmp.h     Thu Nov 22 11:47:11 2001
+++ linux-2.4.20mibp/include/net/snmp.h Tue Apr  8 18:40:09 2003
@@ -268,5 +268,8 @@
 #define SNMP_INC_STATS(mib, field) 
((mib)[2*smp_processor_id()+!in_softirq()].field++)
 #define SNMP_INC_STATS_BH(mib, field) ((mib)[2*smp_processor_id()].field++)
 #define SNMP_INC_STATS_USER(mib, field) ((mib)[2*smp_processor_id()+1].field++)
-       
+#define SNMP_ADD_STATS_BH(mib, field, addend)  \
+       ((mib)[2*smp_processor_id()].field += addend)
+#define SNMP_ADD_STATS_USER(mib, field, addend)        \
+       ((mib)[2*smp_processor_id()+1].field += addend)
 #endif
diff -urN linux-2.4.20/include/net/tcp.h linux-2.4.20mibp/include/net/tcp.h
--- linux-2.4.20/include/net/tcp.h      Thu Nov 28 15:53:15 2002
+++ linux-2.4.20mibp/include/net/tcp.h  Tue Apr  8 18:40:20 2003
@@ -30,6 +30,7 @@
 #include <linux/cache.h>
 #include <net/checksum.h>
 #include <net/sock.h>
+#include <net/snmp.h>
 
 /* This is for all connections with a full identity, no wildcards.
  * New scheme, half the table is for TIME_WAIT, the other half is
@@ -621,6 +622,8 @@
 #define TCP_INC_STATS(field)           SNMP_INC_STATS(tcp_statistics, field)
 #define TCP_INC_STATS_BH(field)                
SNMP_INC_STATS_BH(tcp_statistics, field)
 #define TCP_INC_STATS_USER(field)      SNMP_INC_STATS_USER(tcp_statistics, 
field)
+#define TCP_ADD_STATS_BH(field, val)   SNMP_ADD_STATS_BH(tcp_statistics, 
field, val)
+#define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, 
field, val)
 
 extern void                    tcp_put_port(struct sock *sk);
 extern void                    __tcp_put_port(struct sock *sk);
@@ -1372,6 +1375,9 @@
                break;
 
        case TCP_CLOSE:
+               if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
+                       TCP_INC_STATS(TcpEstabResets);
+
                sk->prot->unhash(sk);
                if (sk->prev && !(sk->userlocks&SOCK_BINDPORT_LOCK))
                        tcp_put_port(sk);
@@ -1830,4 +1836,13 @@
 
 #define TCP_CHECK_TIMER(sk) do { } while (0)
 
+static inline void tcp_mib_init(void)
+{
+       /* See RFC 2012 */
+       TCP_ADD_STATS_USER(TcpRtoAlgorithm, 1);
+       TCP_ADD_STATS_USER(TcpRtoMin, TCP_RTO_MIN*1000/HZ);
+       TCP_ADD_STATS_USER(TcpRtoMax, TCP_RTO_MAX*1000/HZ);
+       TCP_ADD_STATS_USER(TcpMaxConn, -1);
+}
+
 #endif /* _TCP_H */
diff -urN linux-2.4.20/net/ipv4/proc.c linux-2.4.20mibp/net/ipv4/proc.c
--- linux-2.4.20/net/ipv4/proc.c        Thu Nov 28 15:53:15 2002
+++ linux-2.4.20mibp/net/ipv4/proc.c    Tue Apr  8 18:41:06 2003
@@ -134,9 +134,17 @@
        len += sprintf (buffer + len,
                "\nTcp: RtoAlgorithm RtoMin RtoMax MaxConn ActiveOpens 
PassiveOpens AttemptFails EstabResets CurrEstab InSegs OutSegs RetransSegs 
InErrs OutRsts\n"
                  "Tcp:");
-       for (i=0; i<offsetof(struct tcp_mib, __pad)/sizeof(unsigned long); i++)
-               len += sprintf(buffer+len, " %lu", fold_field((unsigned 
long*)tcp_statistics, sizeof(struct tcp_mib), i));
-
+       for (i=0; i<offsetof(struct tcp_mib, __pad)/sizeof(unsigned long); i++) 
{
+               if (i == (offsetof(struct tcp_mib, TcpMaxConn) / 
sizeof(unsigned long)))
+                       /* MaxConn field is negative, RFC 2012 */
+                       len += sprintf(buffer+len, " %d", 
+                                      fold_field((unsigned 
long*)tcp_statistics,
+                                                 sizeof(struct tcp_mib), i));
+               else
+                       len += sprintf(buffer+len, " %lu",
+                                      fold_field((unsigned 
long*)tcp_statistics,
+                                                 sizeof(struct tcp_mib), i));
+       }
        len += sprintf (buffer + len,
                "\nUdp: InDatagrams NoPorts InErrors OutDatagrams\n"
                  "Udp:");
diff -urN linux-2.4.20/net/ipv4/tcp.c linux-2.4.20mibp/net/ipv4/tcp.c
--- linux-2.4.20/net/ipv4/tcp.c Thu Nov 28 15:53:15 2002
+++ linux-2.4.20mibp/net/ipv4/tcp.c     Tue Apr  8 18:40:51 2003
@@ -2641,5 +2641,6 @@
        printk(KERN_INFO "TCP: Hash tables configured (established %d bind 
%d)\n",
               tcp_ehash_size<<1, tcp_bhash_size);
 
+       (void) tcp_mib_init();
        tcpdiag_init();
 }