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Convert DNS code to use ASR

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This commit is contained in:
Mike Belopuhov 2014-03-09 16:09:45 +01:00
parent 718d0c9314
commit e87ab6d0e4
5 changed files with 100 additions and 174 deletions
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3
Makefile
View File

@ -10,6 +10,9 @@ CFLAGS+= -W -Wall -Werror
CFLAGS+= -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations CFLAGS+= -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations
CFLAGS+= -Wshadow -Wpointer-arith -Wcast-qual -Wsign-compare CFLAGS+= -Wshadow -Wpointer-arith -Wcast-qual -Wsign-compare
# hook up asynchronous resolver
CFLAGS+= -I${BSDSRCDIR}/lib/libc/asr
DPADD= ${LIBEVENT} DPADD= ${LIBEVENT}
LDADD= -levent LDADD= -levent

258
dns.c
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@ -1,7 +1,10 @@
/* /*
* Copyright (c) 2014 Mike Belopuhov * Copyright (c) 2014 Mike Belopuhov
* Copyright (c) 2009 Michael Shalayeff *
* All rights reserved. * ASR implementation and OpenSMTPD integration are copyright
* Copyright (c) 2008 Gilles Chehade <gilles@poolp.org>
* Copyright (c) 2009 Jacek Masiulaniec <jacekm@dobremiasto.net>
* Copyright (c) 2011-2012 Eric Faurot <eric@faurot.net>
* *
* Permission to use, copy, modify, and distribute this software for any * Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above * purpose with or without fee is hereby granted, provided that the above
@ -16,186 +19,52 @@
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/ */
#include <sys/param.h> #include <sys/types.h>
#include <sys/socket.h> #include <sys/socket.h>
#include <sys/time.h> #include <sys/time.h>
#include <netinet/in.h> #include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h> #include <errno.h>
#include <event.h>
#include <resolv.h>
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
#include <unistd.h>
#include <syslog.h> #include <syslog.h>
#include <sysexits.h>
#include <login_cap.h> #include "asr.h"
#include <event.h>
#include <pwd.h>
#include <netdb.h>
#include "icb.h" #include "icb.h"
#include "icbd.h" #include "icbd.h"
void dns_dispatch(int, short, void *); struct async_event;
void dns_done(int, short, void *); struct async_event *
async_run_event(struct async *,
struct icbd_dnsquery { void (*)(int, struct async_res *, void *), void *);
uint64_t sid; void dns_done(int, struct async_res *, void *);
union {
struct sockaddr_storage req;
char rep[NI_MAXHOST];
} u;
};
int dns_pipe;
extern int dodns; extern int dodns;
int void
dns_init(void) dns_done(int ev __attribute__((__unused__)), struct async_res *ar, void *arg)
{ {
static struct event ev; struct icb_session *is = arg;
struct passwd *pw;
int pipes[2];
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipes) == -1) { if (ar->ar_gai_errno == 0) {
syslog(LOG_ERR, "socketpair: %m"); syslog(LOG_DEBUG, "dns resolved %s to %s", is->host,
exit(EX_OSERR); is->hostname);
} if (strncmp(is->hostname, "localhost",
sizeof "localhost" - 1) == 0)
switch (fork()) { strlcpy(is->host, "unknown", ICB_MAXHOSTLEN);
case -1: else if (strlen(is->hostname) < ICB_MAXHOSTLEN)
syslog(LOG_ERR, "fork: %m"); strlcpy(is->host, is->hostname, ICB_MAXHOSTLEN);
exit(EX_OSERR); } else
case 0: syslog(LOG_WARNING, "dns resolution failed: %s",
break; gai_strerror(ar->ar_gai_errno));
default:
close(pipes[1]);
dns_pipe = pipes[0];
/* event for the reply */
event_set(&ev, dns_pipe, EV_READ | EV_PERSIST,
dns_done, NULL);
if (event_add(&ev, NULL) < 0) {
syslog(LOG_ERR, "event_add: %m");
exit (EX_UNAVAILABLE);
}
return (0);
}
setproctitle("dns resolver");
close(pipes[0]);
if ((pw = getpwnam(ICBD_USER)) == NULL) {
syslog(LOG_ERR, "No passwd entry for %s", ICBD_USER);
exit(EX_NOUSER);
}
if (chdir("/") < 0) {
syslog(LOG_ERR, "chdir: %m");
exit(EX_UNAVAILABLE);
}
if (setusercontext(NULL, pw, pw->pw_uid,
LOGIN_SETALL & ~LOGIN_SETUSER) < 0)
exit(EX_NOPERM);
if (setuid(pw->pw_uid) < 0) {
syslog(LOG_ERR, "%d: %m", pw->pw_uid);
exit(EX_NOPERM);
}
event_init();
/* event for the request */
event_set(&ev, pipes[1], EV_READ | EV_PERSIST, dns_dispatch, NULL);
if (event_add(&ev, NULL) < 0) {
syslog(LOG_ERR, "event_add: %m");
exit (EX_UNAVAILABLE);
}
return event_dispatch();
} }
void void
dns_dispatch(int fd, short event, void *arg __attribute__((unused))) dns_rresolv(struct icb_session *is, struct sockaddr *sa)
{ {
char host[NI_MAXHOST]; struct async *as;
struct sockaddr *sa;
struct icbd_dnsquery q;
ssize_t res;
int gerr;
if (event != EV_READ)
return;
do
res = read(fd, &q, sizeof q);
while (res == -1 && errno == EINTR);
if (res == -1 && errno == EAGAIN)
return;
if (res < (ssize_t)sizeof q) {
syslog(LOG_ERR, "dns_dispatch read: %m");
/* disable dns resolver */
dodns = 0;
return;
}
sa = (struct sockaddr *)&q.u.req;
if ((gerr = getnameinfo(sa, sa->sa_len,
host, sizeof host, NULL, 0, NI_NOFQDN))) {
syslog(LOG_ERR, "getnameinfo: %s", gai_strerror(gerr));
return;
}
if (verbose)
syslog(LOG_DEBUG, "dns_dispatch: resolved %s", host);
memcpy(&q.u.rep, host, sizeof host);
if (write(fd, &q, sizeof q) != sizeof q)
syslog(LOG_ERR, "dns_dispatch write: %m");
}
void
dns_done(int fd, short event, void *arg __attribute__((unused)))
{
struct icb_session *is;
struct icbd_dnsquery q;
ssize_t res;
if (event != EV_READ)
return;
do
res = read(fd, &q, sizeof q);
while (res == -1 && errno == EINTR);
if (res == -1 && errno == EAGAIN)
return;
if (res < (ssize_t)sizeof q) {
syslog(LOG_ERR, "dns_done read: %m");
return;
}
if ((is = icbd_session_lookup(q.sid)) == NULL) {
syslog(LOG_DEBUG, "failed to find session %llu", q.sid);
return;
}
if (verbose)
syslog(LOG_DEBUG, "icbd_dns: resolved %s to %s",
is->host, q.u.rep);
/* XXX */
if (strcmp(q.u.rep, "localhost") == 0)
strlcpy(is->host, "unknown", ICB_MAXHOSTLEN);
else if (strlen(q.u.rep) < ICB_MAXHOSTLEN)
strlcpy(is->host, q.u.rep, ICB_MAXHOSTLEN);
}
void
dns_rresolv(struct icb_session *is, struct sockaddr_storage *ss)
{
struct icbd_dnsquery q;
if (!dodns) if (!dodns)
return; return;
@ -203,11 +72,64 @@ dns_rresolv(struct icb_session *is, struct sockaddr_storage *ss)
if (verbose) if (verbose)
syslog(LOG_DEBUG, "resolving: %s", is->host); syslog(LOG_DEBUG, "resolving: %s", is->host);
memset(&q, 0, sizeof q); as = getnameinfo_async(sa, sa->sa_len, is->hostname,
q.sid = is->id; sizeof is->hostname, NULL, 0, NI_NOFQDN, NULL);
memcpy(&q.u.req, ss, sizeof *ss); async_run_event(as, dns_done, is);
if (write(dns_pipe, &q, sizeof q) != sizeof q) { }
syslog(LOG_ERR, "dns_rresolv write: %m");
exit(EX_OSERR); /* Generic libevent glue for asr */
struct async_event {
struct async *async;
struct event ev;
void (*callback)(int, struct async_res *, void *);
void *arg;
};
void async_event_dispatch(int, short, void *);
struct async_event *
async_run_event(struct async * async,
void (*cb)(int, struct async_res *, void *), void *arg)
{
struct async_event *aev;
struct timeval tv;
aev = calloc(1, sizeof *aev);
if (aev == NULL)
return (NULL);
aev->async = async;
aev->callback = cb;
aev->arg = arg;
tv.tv_sec = 0;
tv.tv_usec = 0;
evtimer_set(&aev->ev, async_event_dispatch, aev);
evtimer_add(&aev->ev, &tv);
return (aev);
}
void
async_event_dispatch(int fd __attribute__((__unused__)),
short ev __attribute__((__unused__)), void *arg)
{
struct async_event *aev = arg;
struct async_res ar;
int r;
struct timeval tv;
while ((r = asr_async_run(aev->async, &ar)) == ASYNC_YIELD)
aev->callback(r, &ar, aev->arg);
event_del(&aev->ev);
if (r == ASYNC_COND) {
event_set(&aev->ev, ar.ar_fd,
ar.ar_cond == ASYNC_READ ? EV_READ : EV_WRITE,
async_event_dispatch, aev);
tv.tv_sec = ar.ar_timeout / 1000;
tv.tv_usec = (ar.ar_timeout % 1000) * 1000;
event_add(&aev->ev, &tv);
} else { /* ASYNC_DONE */
aev->callback(r, &ar, aev->arg);
free(aev);
} }
} }

1
icb.h
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@ -77,6 +77,7 @@ struct icb_session {
char nick[ICB_MAXNICKLEN]; char nick[ICB_MAXNICKLEN];
char client[ICB_MAXNICKLEN]; char client[ICB_MAXNICKLEN];
char host[ICB_MAXHOSTLEN]; char host[ICB_MAXHOSTLEN];
char hostname[MAXHOSTNAMELEN];
char buffer[ICB_MSGSIZE]; char buffer[ICB_MSGSIZE];
struct event ev; struct event ev;
struct bufferevent *bev; struct bufferevent *bev;

7
icbd.c
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@ -38,6 +38,7 @@
#include <event.h> #include <event.h>
#include <errno.h> #include <errno.h>
#include <err.h> #include <err.h>
#include <resolv.h>
#include "icb.h" #include "icb.h"
#include "icbd.h" #include "icbd.h"
@ -230,8 +231,8 @@ main(int argc, char *argv[])
/* start the logger service */ /* start the logger service */
logger_init(); logger_init();
/* start a dns resolver thread */ /* initialize resolver */
dns_init(); res_init();
if (!foreground) if (!foreground)
icbd_restrict(); icbd_restrict();
@ -635,5 +636,5 @@ getpeerinfo(struct icb_session *is)
(void *)&sin->sin_addr : (void *)&sin6->sin6_addr, (void *)&sin->sin_addr : (void *)&sin6->sin6_addr,
is->host, sizeof is->host); is->host, sizeof is->host);
dns_rresolv(is, &ss); dns_rresolv(is, (struct sockaddr *)&ss);
} }

5
icbd.h
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@ -29,9 +29,8 @@ void icbd_modupdate(void);
time_t getmonotime(void); time_t getmonotime(void);
/* dns.c */ /* dns.c */
struct sockaddr_storage; struct sockaddr;
int dns_init(void); void dns_rresolv(struct icb_session *, struct sockaddr *);
void dns_rresolv(struct icb_session *, struct sockaddr_storage *);
/* logger.c */ /* logger.c */
int logger_init(void); int logger_init(void);