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/* $OpenBSD: snmpd.c,v 1.6 2008/03/16 00:14:47 dlg Exp $ */
/*
* Copyright (c) 2007, 2008 Reyk Floeter <reyk@vantronix.net>
*
* 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 <pwd.h>
#include "snmpd.h"
__dead void usage(void);
void snmpd_sig_handler(int, short, void *);
void snmpd_shutdown(struct snmpd *);
void snmpd_dispatch_snmpe(int, short, void *);
int check_child(pid_t, const char *);
struct snmpd *snmpd_env;
int pipe_parent2snmpe[2];
struct imsgbuf *ibuf_snmpe;
pid_t snmpe_pid = 0;
void
snmpd_sig_handler(int sig, short event, void *arg)
{
struct snmpd *env = arg;
int die = 0;
switch (sig) {
case SIGTERM:
case SIGINT:
die = 1;
/* FALLTHROUGH */
case SIGCHLD:
if (check_child(snmpe_pid, "snmp engine")) {
snmpe_pid = 0;
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;
struct event ev_sigint;
struct event ev_sigterm;
struct event ev_sigchld;
struct event ev_sighup;
int debug = 0;
u_int flags = 0;
int noaction = 0;
const char *conffile = CONF_FILE;
smi_init();
log_init(1); /* log to stderr until daemonized */
while ((c = getopt(argc, argv, "dD:nNf:v")) != -1) {
switch (c) {
case 'd':
debug = 1;
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':
flags |= SNMPD_F_VERBOSE;
break;
default:
usage();
}
}
if ((env = parse_config(conffile, flags)) == NULL)
exit(1);
snmpd_env = env;
if (noaction) {
fprintf(stderr, "configuration ok\n");
exit(0);
}
if (geteuid())
errx(1, "need root privileges");
if (getpwnam(SNMPD_USER) == NULL)
errx(1, "unknown user %s", SNMPD_USER);
log_init(debug);
if (!debug) {
if (daemon(1, 0) == -1)
err(1, "failed to daemonize");
}
gettimeofday(&env->sc_starttime, NULL);
log_info("startup");
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC,
pipe_parent2snmpe) == -1)
fatal("socketpair");
session_socket_blockmode(pipe_parent2snmpe[0], BM_NONBLOCK);
session_socket_blockmode(pipe_parent2snmpe[1], BM_NONBLOCK);
snmpe_pid = snmpe(env, pipe_parent2snmpe);
setproctitle("parent");
event_init();
signal_set(&ev_sigint, SIGINT, snmpd_sig_handler, env);
signal_set(&ev_sigterm, SIGTERM, snmpd_sig_handler, env);
signal_set(&ev_sigchld, SIGCHLD, snmpd_sig_handler, env);
signal_set(&ev_sighup, SIGHUP, snmpd_sig_handler, env);
signal_add(&ev_sigint, NULL);
signal_add(&ev_sigterm, NULL);
signal_add(&ev_sigchld, NULL);
signal_add(&ev_sighup, NULL);
signal(SIGPIPE, SIG_IGN);
close(pipe_parent2snmpe[1]);
if ((ibuf_snmpe = calloc(1, sizeof(struct imsgbuf))) == NULL)
fatal(NULL);
imsg_init(ibuf_snmpe, pipe_parent2snmpe[0], snmpd_dispatch_snmpe);
ibuf_snmpe->events = EV_READ;
event_set(&ibuf_snmpe->ev, ibuf_snmpe->fd, ibuf_snmpe->events,
ibuf_snmpe->handler, ibuf_snmpe);
event_add(&ibuf_snmpe->ev, NULL);
event_dispatch();
return (0);
}
void
snmpd_shutdown(struct snmpd *env)
{
pid_t pid;
if (snmpe_pid)
kill(snmpe_pid, SIGTERM);
do {
if ((pid = wait(NULL)) == -1 &&
errno != EINTR && errno != ECHILD)
fatal("wait");
} while (pid != -1 || (pid == -1 && errno == EINTR));
control_cleanup();
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);
}
void
imsg_event_add(struct imsgbuf *ibuf)
{
ibuf->events = EV_READ;
if (ibuf->w.queued)
ibuf->events |= EV_WRITE;
event_del(&ibuf->ev);
event_set(&ibuf->ev, ibuf->fd, ibuf->events, ibuf->handler, ibuf);
event_add(&ibuf->ev, NULL);
}
void
snmpd_dispatch_snmpe(int fd, short event, void * ptr)
{
struct imsgbuf *ibuf;
struct imsg imsg;
ssize_t n;
ibuf = ptr;
switch (event) {
case EV_READ:
if ((n = imsg_read(ibuf)) == -1)
fatal("imsg_read error");
if (n == 0) {
/* this pipe is dead, so remove the event handler */
event_del(&ibuf->ev);
event_loopexit(NULL);
return;
}
break;
case EV_WRITE:
if (msgbuf_write(&ibuf->w) == -1)
fatal("msgbuf_write");
imsg_event_add(ibuf);
return;
default:
fatalx("unknown event");
}
for (;;) {
if ((n = imsg_get(ibuf, &imsg)) == -1)
fatal("snmpd_dispatch_relay: imsg_read error");
if (n == 0)
break;
switch (imsg.hdr.type) {
default:
log_debug("snmpd_dispatch_relay: unexpected imsg %d",
imsg.hdr.type);
break;
}
imsg_free(&imsg);
}
imsg_event_add(ibuf);
}
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);
}
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