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|
/*-
* Copyright (c) 2009-2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/wait.h>
#include <assert.h>
#include <err.h>
#include <errno.h>
#include <libutil.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include <activemap.h>
#include <pjdlog.h>
#include "control.h"
#include "hast.h"
#include "hast_proto.h"
#include "hastd.h"
#include "subr.h"
/* Path to configuration file. */
static const char *cfgpath = HAST_CONFIG;
/* Hastd configuration. */
static struct hastd_config *cfg;
/* Was SIGCHLD signal received? */
static bool sigchld_received = false;
/* Was SIGHUP signal received? */
static bool sighup_received = false;
/* Was SIGINT or SIGTERM signal received? */
bool sigexit_received = false;
/* PID file handle. */
struct pidfh *pfh;
static void
usage(void)
{
errx(EX_USAGE, "[-dFh] [-c config] [-P pidfile]");
}
static void
sighandler(int sig)
{
switch (sig) {
case SIGCHLD:
sigchld_received = true;
break;
case SIGHUP:
sighup_received = true;
break;
default:
assert(!"invalid condition");
}
}
static void
g_gate_load(void)
{
if (modfind("g_gate") == -1) {
/* Not present in kernel, try loading it. */
if (kldload("geom_gate") == -1 || modfind("g_gate") == -1) {
if (errno != EEXIST) {
pjdlog_exit(EX_OSERR,
"Unable to load geom_gate module");
}
}
}
}
static void
child_exit_log(unsigned int pid, int status)
{
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
pjdlog_debug(1, "Worker process exited gracefully (pid=%u).",
pid);
} else if (WIFSIGNALED(status)) {
pjdlog_error("Worker process killed (pid=%u, signal=%d).",
pid, WTERMSIG(status));
} else {
pjdlog_error("Worker process exited ungracefully (pid=%u, exitcode=%d).",
pid, WIFEXITED(status) ? WEXITSTATUS(status) : -1);
}
}
static void
child_exit(void)
{
struct hast_resource *res;
int status;
pid_t pid;
while ((pid = wait3(&status, WNOHANG, NULL)) > 0) {
/* Find resource related to the process that just exited. */
TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
if (pid == res->hr_workerpid)
break;
}
if (res == NULL) {
/*
* This can happen when new connection arrives and we
* cancel child responsible for the old one.
*/
continue;
}
pjdlog_prefix_set("[%s] (%s) ", res->hr_name,
role2str(res->hr_role));
child_exit_log(pid, status);
proto_close(res->hr_ctrl);
res->hr_workerpid = 0;
if (res->hr_role == HAST_ROLE_PRIMARY) {
/*
* Restart child process if it was killed by signal
* or exited because of temporary problem.
*/
if (WIFSIGNALED(status) ||
(WIFEXITED(status) &&
WEXITSTATUS(status) == EX_TEMPFAIL)) {
sleep(1);
pjdlog_info("Restarting worker process.");
hastd_primary(res);
} else {
res->hr_role = HAST_ROLE_INIT;
pjdlog_info("Changing resource role back to %s.",
role2str(res->hr_role));
}
}
pjdlog_prefix_set("%s", "");
}
}
static void
hastd_reload(void)
{
/* TODO */
pjdlog_warning("Configuration reload is not implemented.");
}
static void
listen_accept(void)
{
struct hast_resource *res;
struct proto_conn *conn;
struct nv *nvin, *nvout, *nverr;
const char *resname;
const unsigned char *token;
char laddr[256], raddr[256];
size_t size;
pid_t pid;
int status;
proto_local_address(cfg->hc_listenconn, laddr, sizeof(laddr));
pjdlog_debug(1, "Accepting connection to %s.", laddr);
if (proto_accept(cfg->hc_listenconn, &conn) < 0) {
pjdlog_errno(LOG_ERR, "Unable to accept connection %s", laddr);
return;
}
proto_local_address(conn, laddr, sizeof(laddr));
proto_remote_address(conn, raddr, sizeof(raddr));
pjdlog_info("Connection from %s to %s.", laddr, raddr);
/* Error in setting timeout is not critical, but why should it fail? */
if (proto_timeout(conn, HAST_TIMEOUT) < 0)
pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
nvin = nvout = nverr = NULL;
/*
* Before receiving any data see if remote host have access to any
* resource.
*/
TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
if (proto_address_match(conn, res->hr_remoteaddr))
break;
}
if (res == NULL) {
pjdlog_error("Client %s isn't known.", raddr);
goto close;
}
/* Ok, remote host can access at least one resource. */
if (hast_proto_recv_hdr(conn, &nvin) < 0) {
pjdlog_errno(LOG_ERR, "Unable to receive header from %s",
raddr);
goto close;
}
resname = nv_get_string(nvin, "resource");
if (resname == NULL) {
pjdlog_error("No 'resource' field in the header received from %s.",
raddr);
goto close;
}
pjdlog_debug(2, "%s: resource=%s", raddr, resname);
token = nv_get_uint8_array(nvin, &size, "token");
/*
* NULL token means that this is first conection.
*/
if (token != NULL && size != sizeof(res->hr_token)) {
pjdlog_error("Received token of invalid size from %s (expected %zu, got %zu).",
raddr, sizeof(res->hr_token), size);
goto close;
}
/*
* From now on we want to send errors to the remote node.
*/
nverr = nv_alloc();
/* Find resource related to this connection. */
TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
if (strcmp(resname, res->hr_name) == 0)
break;
}
/* Have we found the resource? */
if (res == NULL) {
pjdlog_error("No resource '%s' as requested by %s.",
resname, raddr);
nv_add_stringf(nverr, "errmsg", "Resource not configured.");
goto fail;
}
/* Now that we know resource name setup log prefix. */
pjdlog_prefix_set("[%s] (%s) ", res->hr_name, role2str(res->hr_role));
/* Does the remote host have access to this resource? */
if (!proto_address_match(conn, res->hr_remoteaddr)) {
pjdlog_error("Client %s has no access to the resource.", raddr);
nv_add_stringf(nverr, "errmsg", "No access to the resource.");
goto fail;
}
/* Is the resource marked as secondary? */
if (res->hr_role != HAST_ROLE_SECONDARY) {
pjdlog_error("We act as %s for the resource and not as %s as requested by %s.",
role2str(res->hr_role), role2str(HAST_ROLE_SECONDARY),
raddr);
nv_add_stringf(nverr, "errmsg",
"Remote node acts as %s for the resource and not as %s.",
role2str(res->hr_role), role2str(HAST_ROLE_SECONDARY));
goto fail;
}
/* Does token (if exists) match? */
if (token != NULL && memcmp(token, res->hr_token,
sizeof(res->hr_token)) != 0) {
pjdlog_error("Token received from %s doesn't match.", raddr);
nv_add_stringf(nverr, "errmsg", "Toke doesn't match.");
goto fail;
}
/*
* If there is no token, but we have half-open connection
* (only remotein) or full connection (worker process is running)
* we have to cancel those and accept the new connection.
*/
if (token == NULL) {
assert(res->hr_remoteout == NULL);
pjdlog_debug(1, "Initial connection from %s.", raddr);
if (res->hr_workerpid != 0) {
assert(res->hr_remotein == NULL);
pjdlog_debug(1,
"Worker process exists (pid=%u), stopping it.",
(unsigned int)res->hr_workerpid);
/* Stop child process. */
if (kill(res->hr_workerpid, SIGINT) < 0) {
pjdlog_errno(LOG_ERR,
"Unable to stop worker process (pid=%u)",
(unsigned int)res->hr_workerpid);
/*
* Other than logging the problem we
* ignore it - nothing smart to do.
*/
}
/* Wait for it to exit. */
else if ((pid = waitpid(res->hr_workerpid,
&status, 0)) != res->hr_workerpid) {
/* We can only log the problem. */
pjdlog_errno(LOG_ERR,
"Waiting for worker process (pid=%u) failed",
(unsigned int)res->hr_workerpid);
} else {
child_exit_log(res->hr_workerpid, status);
}
res->hr_workerpid = 0;
} else if (res->hr_remotein != NULL) {
char oaddr[256];
proto_remote_address(conn, oaddr, sizeof(oaddr));
pjdlog_debug(1,
"Canceling half-open connection from %s on connection from %s.",
oaddr, raddr);
proto_close(res->hr_remotein);
res->hr_remotein = NULL;
}
}
/*
* Checks and cleanups are done.
*/
if (token == NULL) {
arc4random_buf(res->hr_token, sizeof(res->hr_token));
nvout = nv_alloc();
nv_add_uint8_array(nvout, res->hr_token,
sizeof(res->hr_token), "token");
if (nv_error(nvout) != 0) {
pjdlog_common(LOG_ERR, 0, nv_error(nvout),
"Unable to prepare return header for %s", raddr);
nv_add_stringf(nverr, "errmsg",
"Remote node was unable to prepare return header: %s.",
strerror(nv_error(nvout)));
goto fail;
}
if (hast_proto_send(NULL, conn, nvout, NULL, 0) < 0) {
int error = errno;
pjdlog_errno(LOG_ERR, "Unable to send response to %s",
raddr);
nv_add_stringf(nverr, "errmsg",
"Remote node was unable to send response: %s.",
strerror(error));
goto fail;
}
res->hr_remotein = conn;
pjdlog_debug(1, "Incoming connection from %s configured.",
raddr);
} else {
res->hr_remoteout = conn;
pjdlog_debug(1, "Outgoing connection to %s configured.", raddr);
hastd_secondary(res, nvin);
}
nv_free(nvin);
nv_free(nvout);
nv_free(nverr);
pjdlog_prefix_set("%s", "");
return;
fail:
if (nv_error(nverr) != 0) {
pjdlog_common(LOG_ERR, 0, nv_error(nverr),
"Unable to prepare error header for %s", raddr);
goto close;
}
if (hast_proto_send(NULL, conn, nverr, NULL, 0) < 0) {
pjdlog_errno(LOG_ERR, "Unable to send error to %s", raddr);
goto close;
}
close:
if (nvin != NULL)
nv_free(nvin);
if (nvout != NULL)
nv_free(nvout);
if (nverr != NULL)
nv_free(nverr);
proto_close(conn);
pjdlog_prefix_set("%s", "");
}
static void
main_loop(void)
{
fd_set rfds, wfds;
int fd, maxfd, ret;
for (;;) {
if (sigchld_received) {
sigchld_received = false;
child_exit();
}
if (sighup_received) {
sighup_received = false;
hastd_reload();
}
maxfd = 0;
FD_ZERO(&rfds);
FD_ZERO(&wfds);
/* Setup descriptors for select(2). */
#define SETUP_FD(conn) do { \
fd = proto_descriptor(conn); \
if (fd >= 0) { \
maxfd = fd > maxfd ? fd : maxfd; \
FD_SET(fd, &rfds); \
FD_SET(fd, &wfds); \
} \
} while (0)
SETUP_FD(cfg->hc_controlconn);
SETUP_FD(cfg->hc_listenconn);
#undef SETUP_FD
ret = select(maxfd + 1, &rfds, &wfds, NULL, NULL);
if (ret == -1) {
if (errno == EINTR)
continue;
KEEP_ERRNO((void)pidfile_remove(pfh));
pjdlog_exit(EX_OSERR, "select() failed");
}
#define ISSET_FD(conn) \
(FD_ISSET((fd = proto_descriptor(conn)), &rfds) || FD_ISSET(fd, &wfds))
if (ISSET_FD(cfg->hc_controlconn))
control_handle(cfg);
if (ISSET_FD(cfg->hc_listenconn))
listen_accept();
#undef ISSET_FD
}
}
int
main(int argc, char *argv[])
{
const char *pidfile;
pid_t otherpid;
bool foreground;
int debuglevel;
g_gate_load();
foreground = false;
debuglevel = 0;
pidfile = HASTD_PIDFILE;
for (;;) {
int ch;
ch = getopt(argc, argv, "c:dFhP:");
if (ch == -1)
break;
switch (ch) {
case 'c':
cfgpath = optarg;
break;
case 'd':
debuglevel++;
break;
case 'F':
foreground = true;
break;
case 'P':
pidfile = optarg;
break;
case 'h':
default:
usage();
}
}
argc -= optind;
argv += optind;
pjdlog_debug_set(debuglevel);
pfh = pidfile_open(pidfile, 0600, &otherpid);
if (pfh == NULL) {
if (errno == EEXIST) {
pjdlog_exitx(EX_TEMPFAIL,
"Another hastd is already running, pid: %jd.",
(intmax_t)otherpid);
}
/* If we cannot create pidfile from other reasons, only warn. */
pjdlog_errno(LOG_WARNING, "Cannot open or create pidfile");
}
cfg = yy_config_parse(cfgpath);
assert(cfg != NULL);
signal(SIGHUP, sighandler);
signal(SIGCHLD, sighandler);
/* Listen on control address. */
if (proto_server(cfg->hc_controladdr, &cfg->hc_controlconn) < 0) {
KEEP_ERRNO((void)pidfile_remove(pfh));
pjdlog_exit(EX_OSERR, "Unable to listen on control address %s",
cfg->hc_controladdr);
}
/* Listen for remote connections. */
if (proto_server(cfg->hc_listenaddr, &cfg->hc_listenconn) < 0) {
KEEP_ERRNO((void)pidfile_remove(pfh));
pjdlog_exit(EX_OSERR, "Unable to listen on address %s",
cfg->hc_listenaddr);
}
if (!foreground) {
if (daemon(0, 0) < 0) {
KEEP_ERRNO((void)pidfile_remove(pfh));
pjdlog_exit(EX_OSERR, "Unable to daemonize");
}
/* Start logging to syslog. */
pjdlog_mode_set(PJDLOG_MODE_SYSLOG);
/* Write PID to a file. */
if (pidfile_write(pfh) < 0) {
pjdlog_errno(LOG_WARNING,
"Unable to write PID to a file");
}
}
main_loop();
exit(0);
}
|