nut/server/upsd.c

1021 lines
20 KiB
C
Raw Permalink Normal View History

2010-03-25 23:20:59 +00:00
/* upsd.c - watches ups state files and answers queries
Copyright (C)
1999 Russell Kroll <rkroll@exploits.org>
2008 Arjen de Korte <adkorte-guest@alioth.debian.org>
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "upsd.h"
#include "upstype.h"
#include "conf.h"
#include "netcmds.h"
#include "upsconf.h"
#include <sys/un.h>
#include <sys/socket.h>
#include <netdb.h>
#include <poll.h>
#include "user.h"
#include "ctype.h"
#include "stype.h"
#include "ssl.h"
#include "sstate.h"
#include "desc.h"
#include "neterr.h"
#ifdef HAVE_WRAP
#include <tcpd.h>
int allow_severity = LOG_INFO;
int deny_severity = LOG_WARNING;
#endif /* HAVE_WRAP */
/* externally-visible settings and pointers */
upstype_t *firstups = NULL;
/* default 15 seconds before data is marked stale */
int maxage = 15;
/* preloaded to {OPEN_MAX} in main, can be overridden via upsd.conf */
int maxconn = 0;
/* preloaded to STATEPATH in main, can be overridden via upsd.conf */
char *statepath = NULL;
/* preloaded to DATADIR in main, can be overridden via upsd.conf */
char *datapath = NULL;
/* everything else */
const char *progname;
static ctype_t *firstclient = NULL;
/* static ctype_t *lastclient = NULL; */
/* default is to listen on all local interfaces */
static stype_t *firstaddr = NULL;
static int opt_af = AF_UNSPEC;
typedef enum {
DRIVER = 1,
CLIENT,
SERVER
} handler_type_t;
typedef struct {
handler_type_t type;
void *data;
} handler_t;
/* pollfd */
static struct pollfd *fds = NULL;
static handler_t *handler = NULL;
/* pid file */
static char pidfn[SMALLBUF];
/* set by signal handlers */
static int reload_flag = 0, exit_flag = 0;
static const char *inet_ntopW (struct sockaddr_storage *s)
{
static char str[40];
switch (s->ss_family)
{
case AF_INET:
return inet_ntop (AF_INET, &(((struct sockaddr_in *)s)->sin_addr), str, 16);
case AF_INET6:
return inet_ntop (AF_INET6, &(((struct sockaddr_in6 *)s)->sin6_addr), str, 40);
default:
errno = EAFNOSUPPORT;
return NULL;
}
}
/* return a pointer to the named ups if possible */
upstype_t *get_ups_ptr(const char *name)
{
upstype_t *tmp;
if (!name) {
return NULL;
}
for (tmp = firstups; tmp; tmp = tmp->next) {
if (!strcasecmp(tmp->name, name)) {
return tmp;
}
}
return NULL;
}
/* mark the data stale if this is new, otherwise cleanup any remaining junk */
static void ups_data_stale(upstype_t *ups)
{
/* don't complain again if it's already known to be stale */
if (ups->stale == 1) {
return;
}
ups->stale = 1;
upslogx(LOG_NOTICE, "Data for UPS [%s] is stale - check driver", ups->name);
}
/* mark the data ok if this is new, otherwise do nothing */
static void ups_data_ok(upstype_t *ups)
{
if (ups->stale == 0) {
return;
}
ups->stale = 0;
upslogx(LOG_NOTICE, "UPS [%s] data is no longer stale", ups->name);
}
/* add another listening address */
void listen_add(const char *addr, const char *port)
{
stype_t *server;
/* don't change listening addresses on reload */
if (reload_flag) {
return;
}
/* grab some memory and add the info */
server = xcalloc(1, sizeof(*server));
server->addr = xstrdup(addr);
server->port = xstrdup(port);
server->sock_fd = -1;
server->next = firstaddr;
firstaddr = server;
upsdebugx(3, "listen_add: added %s:%s", server->addr, server->port);
}
/* create a listening socket for tcp connections */
static void setuptcp(stype_t *server)
{
struct addrinfo hints, *res, *ai;
int v = 0, one = 1;
upsdebugx(3, "setuptcp: try to bind to %s port %s", server->addr, server->port);
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_PASSIVE;
hints.ai_family = opt_af;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
if ((v = getaddrinfo(server->addr, server->port, &hints, &res)) != 0) {
if (v == EAI_SYSTEM) {
fatal_with_errno(EXIT_FAILURE, "getaddrinfo");
}
fatalx(EXIT_FAILURE, "getaddrinfo: %s", gai_strerror(v));
}
for (ai = res; ai; ai = ai->ai_next) {
int sock_fd;
if ((sock_fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol)) < 0) {
upsdebug_with_errno(3, "setuptcp: socket");
continue;
}
if (setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one)) != 0) {
fatal_with_errno(EXIT_FAILURE, "setuptcp: setsockopt");
}
if (bind(sock_fd, ai->ai_addr, ai->ai_addrlen) < 0) {
upsdebug_with_errno(3, "setuptcp: bind");
close(sock_fd);
continue;
}
if ((v = fcntl(sock_fd, F_GETFL, 0)) == -1) {
fatal_with_errno(EXIT_FAILURE, "setuptcp: fcntl(get)");
}
if (fcntl(sock_fd, F_SETFL, v | O_NDELAY) == -1) {
fatal_with_errno(EXIT_FAILURE, "setuptcp: fcntl(set)");
}
if (listen(sock_fd, 16) < 0) {
upsdebug_with_errno(3, "setuptcp: listen");
close(sock_fd);
continue;
}
server->sock_fd = sock_fd;
break;
}
freeaddrinfo(res);
/* don't fail silently */
if (server->sock_fd < 0) {
fatalx(EXIT_FAILURE, "not listening on %s port %s", server->addr, server->port);
} else {
upslogx(LOG_INFO, "listening on %s port %s", server->addr, server->port);
}
return;
}
/* decrement the login counter for this ups */
static void declogins(const char *upsname)
{
upstype_t *ups;
ups = get_ups_ptr(upsname);
if (!ups) {
upslogx(LOG_INFO, "Tried to decrement invalid ups name (%s)", upsname);
return;
}
ups->numlogins--;
if (ups->numlogins < 0) {
upslogx(LOG_ERR, "Programming error: UPS [%s] has numlogins=%d", ups->name, ups->numlogins);
}
}
/* disconnect a client connection and free all related memory */
static void client_disconnect(ctype_t *client)
{
if (!client) {
return;
}
upsdebugx(2, "Disconnect from %s", client->addr);
shutdown(client->sock_fd, 2);
close(client->sock_fd);
if (client->loginups) {
declogins(client->loginups);
}
ssl_finish(client);
pconf_finish(&client->ctx);
if (client->prev) {
client->prev->next = client->next;
} else {
/* deleting first entry */
firstclient = client->next;
}
if (client->next) {
client->next->prev = client->prev;
} else {
/* deleting last entry */
/* lastclient = client->prev; */
}
free(client->addr);
free(client->loginups);
free(client->password);
free(client->username);
free(client);
return;
}
/* send the buffer <sendbuf> of length <sendlen> to host <dest> */
int sendback(ctype_t *client, const char *fmt, ...)
{
int res, len;
char ans[NUT_NET_ANSWER_MAX+1];
va_list ap;
if (!client) {
return 0;
}
va_start(ap, fmt);
vsnprintf(ans, sizeof(ans), fmt, ap);
va_end(ap);
len = strlen(ans);
if (client->ssl) {
res = ssl_write(client, ans, len);
} else {
res = write(client->sock_fd, ans, len);
}
upsdebugx(2, "write: [destfd=%d] [len=%d] [%s]", client->sock_fd, len, rtrim(ans, '\n'));
if (len != res) {
upslog_with_errno(LOG_NOTICE, "write() failed for %s", client->addr);
client->last_heard = 0;
return 0; /* failed */
}
return 1; /* OK */
}
/* just a simple wrapper for now */
int send_err(ctype_t *client, const char *errtype)
{
if (!client) {
return -1;
}
upsdebugx(4, "Sending error [%s] to client %s", errtype, client->addr);
return sendback(client, "ERR %s\n", errtype);
}
/* disconnect anyone logged into this UPS */
void kick_login_clients(const char *upsname)
{
ctype_t *client, *cnext;
for (client = firstclient; client; client = cnext) {
cnext = client->next;
/* if it's not logged in, don't check it */
if (!client->loginups) {
continue;
}
if (!strcmp(client->loginups, upsname)) {
upslogx(LOG_INFO, "Kicking client %s (was on UPS [%s])\n", client->addr, upsname);
client_disconnect(client);
}
}
}
/* make sure a UPS is sane - connected, with fresh data */
int ups_available(const upstype_t *ups, ctype_t *client)
{
if (ups->sock_fd < 0) {
send_err(client, NUT_ERR_DRIVER_NOT_CONNECTED);
return 0;
}
if (ups->stale) {
send_err(client, NUT_ERR_DATA_STALE);
return 0;
}
/* must be OK */
return 1;
}
/* check flags and access for an incoming command from the network */
static void check_command(int cmdnum, ctype_t *client, int numarg,
const char **arg)
{
if (netcmds[cmdnum].flags & FLAG_USER) {
#ifdef HAVE_WRAP
struct request_info req;
#endif /* HAVE_WRAP */
if (!client->username) {
send_err(client, NUT_ERR_USERNAME_REQUIRED);
return;
}
if (!client->password) {
send_err(client, NUT_ERR_PASSWORD_REQUIRED);
return;
}
#ifdef HAVE_WRAP
2011-01-26 09:35:08 +00:00
request_init(&req, RQ_DAEMON, progname, RQ_FILE, client->sock_fd, RQ_USER, client->username, 0);
fromhost(&req);
2010-03-25 23:20:59 +00:00
if (!hosts_access(&req)) {
/* tcp-wrappers says access should be denied */
send_err(client, NUT_ERR_ACCESS_DENIED);
return;
}
#endif /* HAVE_WRAP */
}
/* looks good - call the command */
netcmds[cmdnum].func(client, numarg - 1, &arg[1]);
}
/* parse requests from the network */
static void parse_net(ctype_t *client)
{
int i;
/* shouldn't happen */
if (client->ctx.numargs < 1) {
send_err(client, NUT_ERR_UNKNOWN_COMMAND);
return;
}
for (i = 0; netcmds[i].name; i++) {
if (!strcasecmp(netcmds[i].name, client->ctx.arglist[0])) {
check_command(i, client, client->ctx.numargs, (const char **) client->ctx.arglist);
return;
}
}
/* fallthrough = not matched by any entry in netcmds */
send_err(client, NUT_ERR_UNKNOWN_COMMAND);
}
/* answer incoming tcp connections */
static void client_connect(stype_t *server)
{
struct sockaddr_storage csock;
socklen_t clen;
int fd;
ctype_t *client;
clen = sizeof(csock);
fd = accept(server->sock_fd, (struct sockaddr *) &csock, &clen);
if (fd < 0) {
return;
}
client = xcalloc(1, sizeof(*client));
client->sock_fd = fd;
time(&client->last_heard);
client->addr = xstrdup(inet_ntopW(&csock));
pconf_init(&client->ctx, NULL);
if (firstclient) {
firstclient->prev = client;
client->next = firstclient;
}
firstclient = client;
/*
if (lastclient) {
client->prev = lastclient;
lastclient->next = client;
}
lastclient = client;
*/
upsdebugx(2, "Connect from %s", client->addr);
}
/* read tcp messages and handle them */
static void client_readline(ctype_t *client)
{
char buf[SMALLBUF];
int i, ret;
if (client->ssl) {
ret = ssl_read(client, buf, sizeof(buf));
} else {
ret = read(client->sock_fd, buf, sizeof(buf));
}
if (ret < 0) {
upsdebug_with_errno(2, "Disconnect %s (read failure)", client->addr);
client_disconnect(client);
return;
}
if (ret == 0) {
upsdebugx(2, "Disconnect %s (no data available)", client->addr);
client_disconnect(client);
return;
}
/* fragment handling code */
for (i = 0; i < ret; i++) {
/* add to the receive queue one by one */
switch (pconf_char(&client->ctx, buf[i]))
{
case 1:
time(&client->last_heard); /* command received */
parse_net(client);
continue;
case 0:
continue; /* haven't gotten a line yet */
default:
/* parse error */
upslogx(LOG_NOTICE, "Parse error on sock: %s", client->ctx.errmsg);
return;
}
}
return;
}
void server_load(void)
{
stype_t *server;
/* default behaviour if no LISTEN addres has been specified */
if (!firstaddr) {
if (opt_af != AF_INET) {
listen_add("::1", string_const(PORT));
}
if (opt_af != AF_INET6) {
listen_add("127.0.0.1", string_const(PORT));
}
}
for (server = firstaddr; server; server = server->next) {
setuptcp(server);
}
}
void server_free(void)
{
stype_t *server, *snext;
/* cleanup server fds */
for (server = firstaddr; server; server = snext) {
snext = server->next;
if (server->sock_fd != -1) {
close(server->sock_fd);
}
free(server->addr);
free(server->port);
free(server);
}
firstaddr = NULL;
}
static void client_free(void)
{
ctype_t *client, *cnext;
/* cleanup client fds */
for (client = firstclient; client; client = cnext) {
cnext = client->next;
client_disconnect(client);
}
}
void driver_free(void)
{
upstype_t *ups, *unext;
for (ups = firstups; ups; ups = unext) {
unext = ups->next;
if (ups->sock_fd != -1) {
close(ups->sock_fd);
}
sstate_infofree(ups);
sstate_cmdfree(ups);
pconf_finish(&ups->sock_ctx);
free(ups->fn);
free(ups->name);
free(ups->desc);
free(ups);
}
}
static void upsd_cleanup(void)
{
if (strlen(pidfn) > 0) {
unlink(pidfn);
}
/* dump everything */
user_flush();
desc_free();
server_free();
client_free();
driver_free();
free(statepath);
free(datapath);
free(certfile);
free(fds);
free(handler);
}
void poll_reload(void)
{
int ret;
ret = sysconf(_SC_OPEN_MAX);
if (ret < maxconn) {
fatalx(EXIT_FAILURE,
"Your system limits the maximum number of connections to %d\n"
"but you requested %d. The server won't start until this\n"
"problem is resolved.\n", ret, maxconn);
}
fds = xrealloc(fds, maxconn * sizeof(*fds));
handler = xrealloc(handler, maxconn * sizeof(*handler));
}
/* service requests and check on new data */
static void mainloop(void)
{
int i, ret, nfds = 0;
upstype_t *ups;
ctype_t *client, *cnext;
stype_t *server;
time_t now;
time(&now);
if (reload_flag) {
conf_reload();
poll_reload();
reload_flag = 0;
}
/* scan through driver sockets */
for (ups = firstups; ups && (nfds < maxconn); ups = ups->next) {
/* see if we need to (re)connect to the socket */
if (ups->sock_fd < 0) {
ups->sock_fd = sstate_connect(ups);
continue;
}
/* throw some warnings if it's not feeding us data any more */
if (sstate_dead(ups, maxage)) {
ups_data_stale(ups);
} else {
ups_data_ok(ups);
}
fds[nfds].fd = ups->sock_fd;
fds[nfds].events = POLLIN;
handler[nfds].type = DRIVER;
handler[nfds].data = ups;
nfds++;
}
/* scan through client sockets */
for (client = firstclient; client; client = cnext) {
cnext = client->next;
if (difftime(now, client->last_heard) > 60) {
/* shed clients after 1 minute of inactivity */
client_disconnect(client);
continue;
}
if (nfds >= maxconn) {
/* ignore clients that we are unable to handle */
continue;
}
fds[nfds].fd = client->sock_fd;
fds[nfds].events = POLLIN;
handler[nfds].type = CLIENT;
handler[nfds].data = client;
nfds++;
}
/* scan through server sockets */
for (server = firstaddr; server && (nfds < maxconn); server = server->next) {
if (server->sock_fd < 0) {
continue;
}
fds[nfds].fd = server->sock_fd;
fds[nfds].events = POLLIN;
handler[nfds].type = SERVER;
handler[nfds].data = server;
nfds++;
}
upsdebugx(2, "%s: polling %d filedescriptors", __func__, nfds);
ret = poll(fds, nfds, 2000);
if (ret == 0) {
upsdebugx(2, "%s: no data available", __func__);
return;
}
if (ret < 0) {
upslog_with_errno(LOG_ERR, "%s", __func__);
return;
}
for (i = 0; i < nfds; i++) {
if (fds[i].revents & (POLLHUP|POLLERR|POLLNVAL)) {
switch(handler[i].type)
{
case DRIVER:
sstate_disconnect((upstype_t *)handler[i].data);
break;
case CLIENT:
client_disconnect((ctype_t *)handler[i].data);
break;
case SERVER:
upsdebugx(2, "%s: server disconnected", __func__);
break;
default:
upsdebugx(2, "%s: <unknown> disconnected", __func__);
break;
}
continue;
}
if (fds[i].revents & POLLIN) {
switch(handler[i].type)
{
case DRIVER:
sstate_readline((upstype_t *)handler[i].data);
break;
case CLIENT:
client_readline((ctype_t *)handler[i].data);
break;
case SERVER:
client_connect((stype_t *)handler[i].data);
break;
default:
upsdebugx(2, "%s: <unknown> has data available", __func__);
break;
}
continue;
}
}
}
static void help(const char *progname)
{
printf("Network server for UPS data.\n\n");
printf("usage: %s [OPTIONS]\n", progname);
printf("\n");
printf(" -c <command> send <command> via signal to background process\n");
printf(" commands:\n");
printf(" - reload: reread configuration files\n");
printf(" - stop: stop process and exit\n");
printf(" -D raise debugging level\n");
printf(" -h display this help\n");
printf(" -r <dir> chroots to <dir>\n");
2011-01-26 09:35:08 +00:00
printf(" -q raise log level threshold\n");
2010-03-25 23:20:59 +00:00
printf(" -u <user> switch to <user> (if started as root)\n");
printf(" -V display the version of this software\n");
printf(" -4 IPv4 only\n");
printf(" -6 IPv6 only\n");
exit(EXIT_SUCCESS);
}
static void set_reload_flag(int sig)
{
reload_flag = 1;
}
static void set_exit_flag(int sig)
{
exit_flag = sig;
}
static void setup_signals(void)
{
struct sigaction sa;
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGHUP);
sa.sa_flags = 0;
/* basic signal setup to ignore SIGPIPE */
sa.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &sa, NULL);
/* handle shutdown signals */
sa.sa_handler = set_exit_flag;
sigaction(SIGINT, &sa, NULL);
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
/* handle reloading */
sa.sa_handler = set_reload_flag;
sigaction(SIGHUP, &sa, NULL);
}
void check_perms(const char *fn)
{
int ret;
struct stat st;
ret = stat(fn, &st);
if (ret != 0) {
fatal_with_errno(EXIT_FAILURE, "stat %s", fn);
}
/* include the x bit here in case we check a directory */
if (st.st_mode & (S_IROTH | S_IXOTH)) {
upslogx(LOG_WARNING, "%s is world readable", fn);
}
}
int main(int argc, char **argv)
{
int i, cmd = 0;
char *chroot_path = NULL;
2011-01-26 09:35:08 +00:00
const char *user = RUN_AS_USER;
2010-03-25 23:20:59 +00:00
struct passwd *new_uid = NULL;
progname = xbasename(argv[0]);
/* yes, xstrdup - the conf handlers call free on this later */
statepath = xstrdup(dflt_statepath());
datapath = xstrdup(DATADIR);
/* set up some things for later */
2011-01-26 09:35:08 +00:00
snprintf(pidfn, sizeof(pidfn), "%s/%s.pid", altpidpath(), progname);
2010-03-25 23:20:59 +00:00
2011-01-26 09:35:08 +00:00
printf("Network UPS Tools %s %s\n", progname, UPS_VERSION);
2010-03-25 23:20:59 +00:00
2011-01-26 09:35:08 +00:00
while ((i = getopt(argc, argv, "+h46p:qr:i:fu:Vc:D")) != -1) {
2010-03-25 23:20:59 +00:00
switch (i) {
case 'h':
help(progname);
break;
case 'p':
case 'i':
fatalx(EXIT_FAILURE, "Specifying a listening addresses with '-i <address>' and '-p <port>'\n"
"is deprecated. Use 'LISTEN <address> [<port>]' in 'upsd.conf' instead.\n"
"See 'man 8 upsd.conf' for more information.");
2011-01-26 09:35:08 +00:00
case 'q':
nut_log_level++;
break;
2010-03-25 23:20:59 +00:00
case 'r':
chroot_path = optarg;
break;
case 'u':
user = optarg;
break;
case 'V':
/* do nothing - we already printed the banner */
exit(EXIT_SUCCESS);
case 'c':
if (!strncmp(optarg, "reload", strlen(optarg)))
cmd = SIGCMD_RELOAD;
if (!strncmp(optarg, "stop", strlen(optarg)))
cmd = SIGCMD_STOP;
/* bad command given */
if (cmd == 0)
help(progname);
break;
case 'D':
nut_debug_level++;
break;
2011-01-26 09:35:08 +00:00
case '4':
2010-03-25 23:20:59 +00:00
opt_af = AF_INET;
break;
2011-01-26 09:35:08 +00:00
case '6':
2010-03-25 23:20:59 +00:00
opt_af = AF_INET6;
break;
default:
help(progname);
break;
}
}
if (cmd) {
sendsignalfn(pidfn, cmd);
exit(EXIT_SUCCESS);
}
argc -= optind;
argv += optind;
if (argc != 0) {
help(progname);
}
atexit(upsd_cleanup);
setup_signals();
2011-01-26 09:35:08 +00:00
open_syslog(progname);
2010-03-25 23:20:59 +00:00
/* send logging to the syslog pre-background for later use */
syslogbit_set();
/* do this here, since getpwnam() might not work in the chroot */
new_uid = get_user_pwent(user);
if (chroot_path) {
chroot_start(chroot_path);
}
/* default to system limit (may be overridden in upsd.conf */
maxconn = sysconf(_SC_OPEN_MAX);
/* handle upsd.conf */
load_upsdconf(0); /* 0 = initial */
/* start server */
server_load();
2011-01-26 09:35:08 +00:00
/* initialize SSL before we drop privileges (we may not be able to read the keyfile as non-root) */
ssl_init();
2010-03-25 23:20:59 +00:00
become_user(new_uid);
if (chdir(statepath)) {
fatal_with_errno(EXIT_FAILURE, "Can't chdir to %s", statepath);
}
/* check statepath perms */
check_perms(statepath);
/* handle ups.conf */
read_upsconf();
upsconf_add(0); /* 0 = initial */
poll_reload();
if (num_ups == 0) {
fatalx(EXIT_FAILURE, "Fatal error: at least one UPS must be defined in ups.conf");
}
/* try to bring in the var/cmd descriptions */
desc_load();
/* handle upsd.users */
user_load();
if (!nut_debug_level) {
background();
writepid(pidfn);
} else {
memset(pidfn, 0, sizeof(pidfn));
}
while (!exit_flag) {
mainloop();
}
upslogx(LOG_INFO, "Signal %d: exiting", exit_flag);
return EXIT_SUCCESS;
}
2011-01-26 09:35:08 +00:00