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/* $OpenBSD: snmpd.c,v 1.18 2013/10/17 08:42:44 reyk Exp $ */
/*
* Copyright (c) 2007, 2008, 2012 Reyk Floeter <reyk@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/wait.h>
#include <sys/tree.h>
#include <net/if.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <err.h>
#include <errno.h>
#include <event.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <pwd.h>
#include "snmpd.h"
#include "mib.h"
__dead void usage(void);
void snmpd_shutdown(struct snmpd *);
void snmpd_sig_handler(int, short, void *);
int snmpd_dispatch_snmpe(int, struct privsep_proc *, struct imsg *);
void snmpd_generate_engineid(struct snmpd *);
int check_child(pid_t, const char *);
struct snmpd *snmpd_env;
static struct privsep_proc procs[] = {
{ "snmpe", PROC_SNMPE, snmpd_dispatch_snmpe, snmpe, snmpe_shutdown }
};
void
snmpd_sig_handler(int sig, short event, void *arg)
{
struct privsep *ps = arg;
struct snmpd *env = ps->ps_env;
int die = 0, id;
switch (sig) {
case SIGTERM:
case SIGINT:
die = 1;
/* FALLTHROUGH */
case SIGCHLD:
for (id = 0; id < PROC_MAX; id++) {
if (check_child(ps->ps_pid[id],
ps->ps_title[id]))
die = 1;
}
if (die)
snmpd_shutdown(env);
break;
case SIGHUP:
/* reconfigure */
break;
default:
fatalx("unexpected signal");
}
}
/* __dead is for lint */
__dead void
usage(void)
{
extern char *__progname;
fprintf(stderr, "usage: %s [-dNnv] [-D macro=value] "
"[-f file]\n", __progname);
exit(1);
}
int
main(int argc, char *argv[])
{
int c;
struct snmpd *env;
int debug = 0, verbose = 0;
u_int flags = 0;
int noaction = 0;
const char *conffile = CONF_FILE;
struct privsep *ps;
smi_init();
log_init(1); /* log to stderr until daemonized */
while ((c = getopt(argc, argv, "dD:nNf:v")) != -1) {
switch (c) {
case 'd':
debug++;
break;
case 'D':
if (cmdline_symset(optarg) < 0)
log_warnx("could not parse macro definition %s",
optarg);
break;
case 'n':
noaction++;
break;
case 'N':
flags |= SNMPD_F_NONAMES;
break;
case 'f':
conffile = optarg;
break;
case 'v':
verbose++;
flags |= SNMPD_F_VERBOSE;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc > 0)
usage();
if ((env = parse_config(conffile, flags)) == NULL)
exit(1);
ps = &env->sc_ps;
ps->ps_env = env;
snmpd_env = env;
if (noaction) {
fprintf(stderr, "configuration ok\n");
exit(0);
}
if (geteuid())
errx(1, "need root privileges");
if ((ps->ps_pw = getpwnam(SNMPD_USER)) == NULL)
errx(1, "unknown user %s", SNMPD_USER);
log_init(debug);
log_verbose(verbose);
if (!debug && daemon(0, 0) == -1)
err(1, "failed to daemonize");
gettimeofday(&env->sc_starttime, NULL);
env->sc_engine_boots = 0;
pf_init();
snmpd_generate_engineid(env);
proc_init(ps, procs, nitems(procs));
setproctitle("parent");
log_info("startup");
event_init();
signal_set(&ps->ps_evsigint, SIGINT, snmpd_sig_handler, ps);
signal_set(&ps->ps_evsigterm, SIGTERM, snmpd_sig_handler, ps);
signal_set(&ps->ps_evsigchld, SIGCHLD, snmpd_sig_handler, ps);
signal_set(&ps->ps_evsighup, SIGHUP, snmpd_sig_handler, ps);
signal_set(&ps->ps_evsigpipe, SIGPIPE, snmpd_sig_handler, ps);
signal_add(&ps->ps_evsigint, NULL);
signal_add(&ps->ps_evsigterm, NULL);
signal_add(&ps->ps_evsigchld, NULL);
signal_add(&ps->ps_evsighup, NULL);
signal_add(&ps->ps_evsigpipe, NULL);
proc_config(ps, procs, nitems(procs));
event_dispatch();
log_debug("%d parent exiting", getpid());
return (0);
}
void
snmpd_shutdown(struct snmpd *env)
{
proc_kill(&env->sc_ps);
free(env);
log_info("terminating");
exit(0);
}
int
check_child(pid_t pid, const char *pname)
{
int status;
if (waitpid(pid, &status, WNOHANG) > 0) {
if (WIFEXITED(status)) {
log_warnx("check_child: lost child: %s exited", pname);
return (1);
}
if (WIFSIGNALED(status)) {
log_warnx("check_child: lost child: %s terminated; "
"signal %d", pname, WTERMSIG(status));
return (1);
}
}
return (0);
}
int
snmpd_dispatch_snmpe(int fd, struct privsep_proc *p, struct imsg *imsg)
{
switch (imsg->hdr.type) {
case IMSG_CTL_RELOAD:
/* XXX notyet */
default:
break;
}
return (-1);
}
int
snmpd_socket_af(struct sockaddr_storage *ss, in_port_t port)
{
int s;
switch (ss->ss_family) {
case AF_INET:
((struct sockaddr_in *)ss)->sin_port = port;
((struct sockaddr_in *)ss)->sin_len =
sizeof(struct sockaddr_in);
break;
case AF_INET6:
((struct sockaddr_in6 *)ss)->sin6_port = port;
((struct sockaddr_in6 *)ss)->sin6_len =
sizeof(struct sockaddr_in6);
break;
default:
return (-1);
}
s = socket(ss->ss_family, SOCK_DGRAM, IPPROTO_UDP);
return (s);
}
void
snmpd_generate_engineid(struct snmpd *env)
{
u_int32_t oid_enterprise, rnd, tim;
/* RFC 3411 */
memset(env->sc_engineid, 0, sizeof(env->sc_engineid));
oid_enterprise = htonl(OIDVAL_openBSD_eid);
memcpy(env->sc_engineid, &oid_enterprise, sizeof(oid_enterprise));
env->sc_engineid[0] |= SNMP_ENGINEID_NEW;
env->sc_engineid_len = sizeof(oid_enterprise);
/* XXX alternatively configure engine id via snmpd.conf */
env->sc_engineid[(env->sc_engineid_len)++] = SNMP_ENGINEID_FMT_EID;
rnd = arc4random();
memcpy(&env->sc_engineid[env->sc_engineid_len], &rnd, sizeof(rnd));
env->sc_engineid_len += sizeof(rnd);
tim = htonl(env->sc_starttime.tv_sec);
memcpy(&env->sc_engineid[env->sc_engineid_len], &tim, sizeof(tim));
env->sc_engineid_len += sizeof(tim);
}
u_long
snmpd_engine_time(void)
{
struct timeval now;
/*
* snmpEngineBoots should be stored in a non-volatile storage.
* snmpEngineTime is the number of seconds since snmpEngineBoots
* was last incremented. We don't rely on non-volatile storage.
* snmpEngineBoots is set to zero and snmpEngineTime to the system
* clock. Hence, the tuple (snmpEngineBoots, snmpEngineTime) is
* still unique and protects us against replay attacks. It only
* 'expires' a little bit sooner than the RFC3414 method.
*/
gettimeofday(&now, NULL);
return now.tv_sec;
}
char *
tohexstr(u_int8_t *str, int len)
{
#define MAXHEXSTRLEN 256
static char hstr[2 * MAXHEXSTRLEN + 1];
char *r = hstr;
if (len > MAXHEXSTRLEN)
len = MAXHEXSTRLEN; /* truncate */
while (len-- > 0)
r += snprintf(r, len * 2, "%0*x", 2, *str++);
*r = '\0';
return hstr;
}
void
socket_set_blockmode(int fd, enum blockmodes bm)
{
int flags;
if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
fatal("fcntl F_GETFL");
if (bm == BM_NONBLOCK)
flags |= O_NONBLOCK;
else
flags &= ~O_NONBLOCK;
if ((flags = fcntl(fd, F_SETFL, flags)) == -1)
fatal("fcntl F_SETFL");
}
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