[PATCH] ipchains log will show all flags

From: Christian W. Zuckschwerdt (zany@triq.net)
Date: Tue Dec 05 2000 - 08:22:00 EST

Hi Linus,

This tiny patch extends ipchains logging. This way one can distinguish
(plain) connection attempts and (Xmas, Fin,...) scans. E.g.
 kernel: Packet log: input - lo PROTO=6 127.0.0.1:40326 127.0.0.1:80
  L=40 S=0x00 I=5808 F=0x0000 T=51 (#1)
 vs.
  L=40 S=0x00 I=5808 F=0x0000 T=51 (#1) B=-s--a-
 and
  L=40 S=0x00 I=5808 F=0x0000 T=51 (#1) B=fs-p-u

Please comment on the format (B=...) and implementation details (speed).
The patch is against 2.2.17's /net/ipv4/ip_fw.c

ipchains log with flags Christian W. Zuckschwerdt <zany@triq.net>

--- linux-2.2.17-pristine/net/ipv4/ip_fw.c.orig Mon Nov 27 00:38:36 2000
+++ linux-2.2.17/net/ipv4/ip_fw.c Sun Dec 3 23:58:06 2000
@@ -415,6 +415,7 @@
 {
         __u32 *opt = (__u32 *) (ip + 1);
         int opti;
+ struct tcphdr *tcp=(struct tcphdr *)((__u32 *)ip+ip->ihl);
         
         if (f)
         {
@@ -443,7 +444,15 @@
 
         for (opti = 0; opti < (ip->ihl - sizeof(struct iphdr) / 4); opti++)
                 printk(" O=0x%8.8X", *opt++);
- printk(" %s(#%d)\n", syn ? "SYN " : /* "PENANCE" */ "", count);
+ printk(" %s(#%d)", syn ? "SYN " : /* "PENANCE" */ "", count);
+
+ if (ip->protocol == IPPROTO_TCP)
+ printk(" B=%c%c%c%c%c%c\n", tcp->fin ? 'f' : '-',
+ tcp-syn ? 's' : '-', tcp->rst ? 'r' : '-',
+ tcp->psh ? 'p' : '-', tcp->ack ? 'a' : '-',
+ tcp->urg ? 'u' : '-');
+ else
+ printk("\n");
 }
 
 /* function for checking chain labels for user space. */ 

-- 
  cu.
    :
    Christian

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This archive was generated by hypermail 2b29 : Thu Dec 07 2000 - 21:00:13 EST