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tcpdrop: allow TCP connections to be filtered by cc-algo

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In addition to filtering by stack and state, allow filtering
by the congestion control module used.  Choose the command line
options to be consistent with the ones of sockstat.

MFC after:	1 week
Sponsored by:	Netflix, Inc.
This commit is contained in:
Michael Tuexen 2021-12-04 15:00:05 +01:00
parent 130df64793
commit 31537ea583
2 changed files with 55 additions and 18 deletions
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45
usr.sbin/tcpdrop/tcpdrop.8
View File

@ -34,13 +34,18 @@
.Fl a
.Nm tcpdrop
.Op Fl l
.Fl S Ar stack
.Fl C Ar cc-algo
.Op Fl S Ar stack
.Op Fl s Ar state
.Nm tcpdrop
.Op Fl l
.Fl s Ar state
.Op Fl C Ar cc-algo
.Fl S Ar stack
.Op Fl s Ar state
.Nm tcpdrop
.Op Fl l
.Fl S Ar stack
.Op Fl C Ar cc-algo
.Op Fl S Ar stack
.Fl s Ar state
.Sh DESCRIPTION
The
@ -54,6 +59,13 @@ is specified then
will attempt to drop all TCP connections.
.Pp
If
.Fl C Ar cc-algo
is specified then
.Nm
will attempt to drop all connections using the TCP congestion control algorithm
.Ar cc-algo .
.Pp
If
.Fl S Ar stack
is specified then
.Nm
@ -78,16 +90,20 @@ is one of
.Dv FIN_WAIT_2 , or
.Dv TIME_WAIT .
.Pp
If
.Fl S Ar stack
If multiple of
.Fl C Ar cc-algo ,
.Fl S Ar stack ,
and
.Fl s Ar state
are specified,
.Nm
will attempt to drop all TCP connections being in the state
.Ar state
will attempt to drop all TCP connections using the congestion control algorithm
.Ar cc-algo ,
being in the state
.Ar state ,
and using the TCP stack
.Ar stack .
.Ar stack ,
if specified.
Since TCP connections in the
.Dv TIME_WAIT
state are not tied to any TCP stack, using the option
@ -102,6 +118,7 @@ The
.Fl l
flag may be given in addition to the
.Fl a ,
.Fl C ,
.Fl S ,
or
.Fl s
@ -110,6 +127,7 @@ connections one at a time.
.Pp
If none of the
.Fl a ,
.Fl C ,
.Fl S ,
or
.Fl s
@ -154,6 +172,11 @@ port 22, the port used by
# tcpdrop -l -a | grep -vw 22 | sh
.Ed
.Pp
To drop all TCP connections using the new-reno congestion control algorithm use:
.Bd -literal -offset indent
# tcpdrop -C new-reno
.Ed
.Pp
The following command will drop all connections using the TCP stack
rack:
.Bd -literal -offset indent
@ -165,10 +188,10 @@ To drop all TCP connections in the LAST_ACK state use:
# tcpdrop -s LAST_ACK
.Ed
.Pp
To drop all TCP connections using the TCP stack rack and being in the
LAST_ACK state use:
To drop all TCP connections using the congestion control algorithm new-reno and
the TCP stack rack and being in the LAST_ACK state use:
.Bd -literal -offset indent
# tcpdrop -S rack -s LAST_ACK
# tcpdrop -C new-reno -S rack -s LAST_ACK
.Ed
.Sh SEE ALSO
.Xr netstat 1 ,

28
usr.sbin/tcpdrop/tcpdrop.c
View File

@ -54,7 +54,7 @@ static char *findport(const char *);
static struct xinpgen *getxpcblist(const char *);
static void sockinfo(const struct sockaddr *, struct host_service *);
static bool tcpdrop(const struct sockaddr *, const struct sockaddr *);
static bool tcpdropall(const char *, int);
static bool tcpdropall(const char *, const char *, int);
static bool tcpdropbyname(const char *, const char *, const char *,
const char *);
static bool tcpdropconn(const struct in_conninfo *);
@ -67,20 +67,26 @@ int
main(int argc, char *argv[])
{
char stack[TCP_FUNCTION_NAME_LEN_MAX];
char ca_name[TCP_CA_NAME_MAX];
char *lport, *fport;
bool dropall, dropspecific;
int ch, state;
dropall = false;
dropspecific = false;
ca_name[0] = '\0';
stack[0] = '\0';
state = -1;
while ((ch = getopt(argc, argv, "alS:s:")) != -1) {
while ((ch = getopt(argc, argv, "aC:lS:s:")) != -1) {
switch (ch) {
case 'a':
dropall = true;
break;
case 'C':
dropspecific = true;
strlcpy(ca_name, optarg, sizeof(ca_name));
break;
case 'l':
tcpdrop_list_commands = true;
break;
@ -111,7 +117,7 @@ main(int argc, char *argv[])
if (dropall || dropspecific) {
if (argc != 0)
usage();
if (!tcpdropall(stack, state))
if (!tcpdropall(ca_name, stack, state))
exit(1);
exit(0);
}
@ -223,7 +229,7 @@ tcpdrop(const struct sockaddr *lsa, const struct sockaddr *fsa)
}
static bool
tcpdropall(const char *stack, int state)
tcpdropall(const char *ca_name, const char *stack, int state)
{
struct xinpgen *head, *xinp;
struct xtcpcb *xtp;
@ -259,6 +265,14 @@ tcpdropall(const char *stack, int state)
if ((state != -1) && (xtp->t_state != state))
continue;
/*
* If requested, skip sockets not having the requested
* congestion control algorithm.
*/
if (ca_name[0] != '\0' &&
strncmp(xtp->xt_cc, ca_name, TCP_CA_NAME_MAX))
continue;
/* If requested, skip sockets not having the requested stack. */
if (stack[0] != '\0' &&
strncmp(xtp->xt_stack, stack, TCP_FUNCTION_NAME_LEN_MAX))
@ -379,8 +393,8 @@ usage(void)
" tcpdrop local-address:local-port foreign-address:foreign-port\n"
" tcpdrop local-address.local-port foreign-address.foreign-port\n"
" tcpdrop [-l] -a\n"
" tcpdrop [-l] -S stack\n"
" tcpdrop [-l] -s state\n"
" tcpdrop [-l] -S stack -s state\n");
" tcpdrop [-l] -C cc-algo [-S stack] [-s state]\n"
" tcpdrop [-l] [-C cc-algo] -S stack [-s state]\n"
" tcpdrop [-l] [-C cc-algo] [-S stack] -s state\n");
exit(1);
}