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samba-mirror/ctdb/tools/ctdb_killtcp.c
Martin Schwenke 201066d2e6 ctdb-tools: Fix signed/unsigned comparison by declaring as unsigned
Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
2019-06-05 10:25:49 +00:00

418 lines
10 KiB
C

/*
CTDB TCP connection killing utility
Copyright (C) Martin Schwenke <martin@meltin.net> 2016
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "system/network.h"
#include <talloc.h>
#include <tevent.h>
#include "lib/util/debug.h"
#include "lib/util/tevent_unix.h"
#include "protocol/protocol.h"
#include "protocol/protocol_util.h"
#include "common/db_hash.h"
#include "common/system_socket.h"
#include "common/logging.h"
struct reset_connections_state {
struct tevent_context *ev;
int capture_fd;
struct tevent_fd *fde;
struct db_hash_context *connections;
void *private_data;
unsigned int attempts;
unsigned int max_attempts;
struct timeval retry_interval;
unsigned int batch_count;
unsigned int batch_size;
};
static void reset_connections_capture_tcp_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags,
void *private_data);
static void reset_connections_batch(struct tevent_req *subreq);
static int reset_connections_tickle_connection(
uint8_t *keybuf, size_t keylen,
uint8_t *databuf, size_t datalen,
void *private_data);
static struct tevent_req *reset_connections_send(
TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
const char *iface,
struct ctdb_connection_list *conn_list)
{
struct tevent_req *req, *subreq;
struct reset_connections_state *state;
unsigned int i;
int ret;
req = tevent_req_create(mem_ctx, &state,
struct reset_connections_state);
if (req == NULL) {
return NULL;
}
state->ev = ev;
if (conn_list->num == 0) {
/* No connections, done! */
tevent_req_done(req);
return tevent_req_post(req, ev);
}
ret = db_hash_init(state, "connections", 2048, DB_HASH_SIMPLE,
&state->connections);
if (ret != 0) {
D_ERR("Failed to initialise connection hash (%s)\n",
strerror(ret));
tevent_req_error(req, ret);
return tevent_req_post(req, ev);
}
DBG_DEBUG("Adding %u connections to hash\n", conn_list->num);
for (i = 0; i < conn_list->num; i++) {
struct ctdb_connection *c = &conn_list->conn[i];
DBG_DEBUG("Adding connection to hash: %s\n",
ctdb_connection_to_string(conn_list, c, true));
/* Connection is stored as a key in the connections hash */
ret = db_hash_add(state->connections,
(uint8_t *)discard_const(c), sizeof(*c),
NULL, 0);
if (ret != 0) {
D_ERR("Error adding connection to hash (%s)\n",
strerror(ret));
tevent_req_error(req, ret);
return tevent_req_post(req, ev);
}
}
state->attempts = 0;
state->max_attempts = 50;
state->retry_interval.tv_sec = 0;
state->retry_interval.tv_usec = 100 * 1000;
state->batch_count = 0;
state->batch_size = 300;
state->capture_fd =
ctdb_sys_open_capture_socket(iface, &state->private_data);
if (state->capture_fd == -1) {
D_ERR("Failed to open capture socket on iface '%s' (%s)\n",
iface, strerror(errno));
tevent_req_error(req, EIO);
return tevent_req_post(req, ev);
}
state->fde = tevent_add_fd(ev, state, state->capture_fd,
TEVENT_FD_READ,
reset_connections_capture_tcp_handler,
state);
if (tevent_req_nomem(state->fde, req)) {
return tevent_req_post(req, ev);
}
tevent_fd_set_auto_close(state->fde);
subreq = tevent_wakeup_send(state, ev, tevent_timeval_current_ofs(0,0));
if (tevent_req_nomem(subreq, req)) {
return tevent_req_post(req, ev);
}
tevent_req_set_callback(subreq, reset_connections_batch, req);
return req;
}
/*
called when we get a read event on the raw socket
*/
static void reset_connections_capture_tcp_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags,
void *private_data)
{
struct reset_connections_state *state = talloc_get_type_abort(
private_data, struct reset_connections_state);
/* 0 the parts that don't get set by ctdb_sys_read_tcp_packet */
struct ctdb_connection conn;
uint32_t ack_seq, seq;
int rst;
uint16_t window;
int ret;
ret = ctdb_sys_read_tcp_packet(state->capture_fd,
state->private_data,
&conn.server, &conn.client,
&ack_seq, &seq, &rst, &window);
if (ret != 0) {
/* probably a non-tcp ACK packet */
return;
}
if (window == htons(1234) && (rst || seq == 0)) {
/* Ignore packets that we sent! */
D_DEBUG("Ignoring packet: %s, "
"seq=%"PRIu32", ack_seq=%"PRIu32", "
"rst=%d, window=%"PRIu16"\n",
ctdb_connection_to_string(state, &conn, false),
seq, ack_seq, rst, ntohs(window));
return;
}
/* Check if this connection is one being reset, if found then delete */
ret = db_hash_delete(state->connections,
(uint8_t*)&conn, sizeof(conn));
if (ret == ENOENT) {
/* Packet for some other connection, ignore */
DBG_DEBUG("Ignoring packet for unknown connection: %s\n",
ctdb_connection_to_string(state, &conn, true));
return;
}
if (ret != 0) {
DBG_WARNING("Internal error (%s)\n", strerror(ret));
return;
}
D_INFO("Sending a TCP RST to for connection %s\n",
ctdb_connection_to_string(state, &conn, true));
ret = ctdb_sys_send_tcp(&conn.server, &conn.client, ack_seq, seq, 1);
if (ret != 0) {
DBG_ERR("Error sending TCP RST for connection\n");
}
}
/*
* Called periodically until all sentenced connections have been reset
* or enough attempts have been made
*/
static void reset_connections_batch(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(
subreq, struct tevent_req);
struct reset_connections_state *state = tevent_req_data(
req, struct reset_connections_state);
bool status;
int count, ret;
status = tevent_wakeup_recv(subreq);
TALLOC_FREE(subreq);
if (! status) {
DBG_WARNING("Unexpected error on timer expiry\n");
/* Keep going... */
}
/* loop over up to batch_size connections sending tickle ACKs */
state->batch_count = 0;
ret = db_hash_traverse(state->connections,
reset_connections_tickle_connection,
state, NULL);
if (ret != 0) {
DBG_WARNING("Unexpected error traversing connections (%s)\n",
strerror(ret));
}
state->attempts++;
/*
* If there are no more connections to kill or we have tried
* too many times we're finished
*/
ret = db_hash_traverse(state->connections, NULL, NULL, &count);
if (ret != 0) {
/* What now? Try again until max_attempts reached */
DBG_WARNING("Unexpected error traversing connections (%s)\n",
strerror(ret));
count = 1;
}
if (count == 0 ||
state->attempts >= state->max_attempts) {
tevent_req_done(req);
return;
}
/* Schedule next attempt */
subreq = tevent_wakeup_send(state, state->ev,
tevent_timeval_current_ofs(
state->retry_interval.tv_sec,
state->retry_interval.tv_usec));
if (tevent_req_nomem(subreq, req)) {
return;
}
tevent_req_set_callback(subreq, reset_connections_batch, req);
}
static int reset_connections_tickle_connection(
uint8_t *keybuf, size_t keylen,
uint8_t *databuf, size_t datalen,
void *private_data)
{
struct reset_connections_state *state = talloc_get_type_abort(
private_data, struct reset_connections_state);
struct ctdb_connection *conn;
int ret;
if (keylen != sizeof(*conn)) {
DBG_WARNING("Unexpected data in connection hash\n");
return 0;
}
conn = (struct ctdb_connection *)keybuf;
state->batch_count++;
if (state->batch_count > state->batch_size) {
/* Terminate the traverse */
return 1;
}
DBG_DEBUG("Sending tickle ACK for connection '%s'\n",
ctdb_connection_to_string(state, conn, true));
ret = ctdb_sys_send_tcp(&conn->server, &conn->client, 0, 0, 0);
if (ret != 0) {
DBG_ERR("Error sending tickle ACK\n");
/* continue */
}
return 0;
}
static bool reset_connections_recv(struct tevent_req *req, int *perr)
{
int err;
if (tevent_req_is_unix_error(req, &err)) {
if (perr != NULL) {
*perr = err;
}
return false;
}
return true;
}
static void usage(const char *prog)
{
printf("usage: %s <interface> [ <srcip:port> <dstip:port> ]\n", prog);
exit(1);
}
int main(int argc, char **argv)
{
struct ctdb_connection conn;
struct tevent_context *ev = NULL;
TALLOC_CTX *mem_ctx = NULL;
struct ctdb_connection_list *conn_list = NULL;
const char *t;
struct tevent_req *req;
int debug_level;
bool status;
bool ok;
int ret;
/* Set the debug level */
t = getenv("CTDB_DEBUGLEVEL");
if (t != NULL) {
ok = debug_level_parse(t, &debug_level);
if (!ok) {
debug_level = DEBUG_ERR;
}
debuglevel_set(debug_level);
}
if (argc != 2 && argc != 4) {
usage(argv[0]);
}
if (argc == 4) {
ret = ctdb_sock_addr_from_string(argv[2], &conn.client, true);
if (ret != 0) {
D_ERR("Bad IP:port '%s'\n", argv[2]);
goto fail;
}
ret = ctdb_sock_addr_from_string(argv[3], &conn.server, true);
if (ret != 0) {
D_ERR("Bad IP:port '%s'\n", argv[3]);
goto fail;
}
conn_list = talloc_zero(mem_ctx, struct ctdb_connection_list);
if (conn_list == NULL) {
ret = ENOMEM;
DBG_ERR("Internal error (%s)\n", strerror(ret));
goto fail;
}
ret = ctdb_connection_list_add(conn_list, &conn);
if (ret != 0) {
DBG_ERR("Internal error (%s)\n", strerror(ret));
goto fail;
}
} else {
ret = ctdb_connection_list_read(mem_ctx, 0, true, &conn_list);
if (ret != 0) {
D_ERR("Unable to parse connections (%s)\n",
strerror(ret));
goto fail;
}
}
mem_ctx = talloc_new(NULL);
if (mem_ctx == NULL) {
DEBUG(DEBUG_ERR, (__location__ " out of memory\n"));
goto fail;
}
ev = tevent_context_init(mem_ctx);
if (ev == NULL) {
DEBUG(DEBUG_ERR, ("Failed to initialise tevent\n"));
goto fail;
}
req = reset_connections_send(mem_ctx, ev, argv[1], conn_list);
if (req == NULL) {
goto fail;
}
tevent_req_poll(req, ev);
status = reset_connections_recv(req, &ret);
if (! status) {
D_ERR("Failed to kill connections (%s)\n", strerror(ret));
goto fail;
}
talloc_free(mem_ctx);
return 0;
fail:
TALLOC_FREE(mem_ctx);
return -1;
}