12-14-2009
Corona688, thanks for your input. But I think you agree with me that that's not exaclty it. With strace I cannot see how exactly read/write API calls are mapped into block devide requests, next - a very important one - I cannot see how efficiently I utilize FS. For example on some filesystems I have to allocate file in large chunks and then fseek, on others I have to append, so on... - all these choises become obvious once I can see what's going on under the hood...
PS
I think once I found a tool that did exactly what I need by installing a driver under /proc but now I can't find it anymore...
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PFLOG(4) BSD Kernel Interfaces Manual PFLOG(4)
NAME
pflog -- packet filter logging interface
SYNOPSIS
device pflog
DESCRIPTION
The pflog interface is a pseudo-device which makes visible all packets logged by the packet filter, pf(4). Logged packets can easily be mon-
itored in real time by invoking tcpdump(1) on the pflog interface, or stored to disk using pflogd(8).
The pflog0 interface is created automatically at boot if both pf(4) and pflogd(8) are enabled; further instances can be created using
ifconfig(8).
Each packet retrieved on this interface has a header associated with it of length PFLOG_HDRLEN. This header documents the address family,
interface name, rule number, reason, action, and direction of the packet that was logged. This structure, defined in <net/if_pflog.h> looks
like
struct pfloghdr {
u_int8_t length;
sa_family_t af;
u_int8_t action;
u_int8_t reason;
char ifname[IFNAMSIZ];
char ruleset[PF_RULESET_NAME_SIZE];
u_int32_t rulenr;
u_int32_t subrulenr;
uid_t uid;
pid_t pid;
uid_t rule_uid;
pid_t rule_pid;
u_int8_t dir;
u_int8_t pad[3];
};
EXAMPLES
Create a pflog interface and monitor all packets logged on it:
# ifconfig pflog1 up
# tcpdump -n -e -ttt -i pflog1
SEE ALSO
tcpdump(1) inet(4), inet6(4), netintro(4), pf(4), ifconfig(8), pflogd(8)
HISTORY
The pflog device first appeared in OpenBSD 3.0.
BSD December 10, 2001 BSD