/*
* ngIRCd -- The Next Generation IRC Daemon
* Copyright (c)2005-2006 Florian Westphal (westphal@foo.fh-furtwangen.de)
* Copyright (c)2006-2014 Alexander Barton (alex@barton.de) and Contributors.
*
* 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.
* Please read the file COPYING, README and AUTHORS for more information.
*/
#include "portab.h"
/**
* @file
* I/O abstraction interface.
*/
/* Extra debug messages in event add/delete/callback code: 0=off / 1=on */
#define DEBUG_IO 0
#include <assert.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "array.h"
#include "io.h"
#include "log.h"
typedef struct {
#ifdef PROTOTYPES
void (*callback)(int, short);
#else
void (*callback)();
#endif
short what;
} io_event;
#define INIT_IOEVENT { NULL, -1, 0, NULL }
#define IO_ERROR 4
#define MAX_EVENTS 100
#ifdef HAVE_EPOLL_CREATE
# define IO_USE_EPOLL 1
# ifdef HAVE_SELECT
# define IO_USE_SELECT 1
# endif
#else
# ifdef HAVE_KQUEUE
# define IO_USE_KQUEUE 1
# else
# ifdef HAVE_SYS_DEVPOLL_H
# define IO_USE_DEVPOLL 1
# else
# if defined(HAVE_POLL) && defined(HAVE_POLL_H)
# define IO_USE_POLL 1
# else
# ifdef HAVE_SELECT
# define IO_USE_SELECT 1
# else
# error "no IO API available!?"
# endif /* HAVE_SELECT */
# endif /* HAVE_POLL */
# endif /* HAVE_SYS_DEVPOLL_H */
# endif /* HAVE_KQUEUE */
#endif /* HAVE_EPOLL_CREATE */
static bool library_initialized = false;
#ifdef IO_USE_EPOLL
#include <sys/epoll.h>
static int io_masterfd = -1;
static bool io_event_change_epoll(int fd, short what, const int action);
static int io_dispatch_epoll(struct timeval *tv);
#endif
#ifdef IO_USE_KQUEUE
#include <sys/types.h>
#include <sys/event.h>
static array io_evcache;
static int io_masterfd;
static int io_dispatch_kqueue(struct timeval *tv);
static bool io_event_change_kqueue(int, short, const int action);
#ifndef EV_SET
/* Taken from /usr/include/sys/event.h of FreeBSD 8.1 and required by all
* platforms that have kqueue but lack EV_SET() -- for example FreeBSD 4. */
#define EV_SET(kevp, a, b, c, d, e, f) do { \
struct kevent *__kevp__ = (kevp); \
__kevp__->ident = (a); \
__kevp__->filter = (b); \
__kevp__->flags = (c); \
__kevp__->fflags = (d); \
__kevp__->data = (e); \
__kevp__->udata = (f); \
} while(0)
#endif
#endif
#ifdef IO_USE_POLL
#include <poll.h>
static array pollfds;
static int poll_maxfd;
static bool io_event_change_poll PARAMS((int fd, short what));
#endif
#ifdef IO_USE_DEVPOLL
#include <sys/devpoll.h>
static int io_masterfd;
static bool io_event_change_devpoll(int fd, short what);
#endif
#ifdef IO_USE_SELECT
#include <sys/time.h>
#include "defines.h" /* for conn.h */
#include "proc.h" /* for PROC_STAT (needed by conf.h) */
#include "conn.h" /* for CONN_ID (needed by conf.h) */
#include "conf.h" /* for Conf_MaxConnections */
static fd_set readers;
static fd_set writers;
/*
* this is the first argument for select(), i.e.
* the largest fd registered, plus one.
*/
static int select_maxfd;
static int io_dispatch_select PARAMS((struct timeval *tv));
#ifndef IO_USE_EPOLL
#define io_masterfd -1
#endif
#endif /* IO_USE_SELECT */
static array io_events;
static void io_docallback PARAMS((int fd, short what));
#if DEBUG_IO
static void
io_debug(const char *s, int fd, int what)
{
Log(LOG_DEBUG, "%s: %d, %d\n", s, fd, what);
}
#else
static inline void
io_debug(const char UNUSED *s,int UNUSED a, int UNUSED b)
{ /* NOTHING */ }
#endif
static io_event *
io_event_get(int fd)
{
io_event *i;
assert(fd >= 0);
i = (io_event *) array_get(&io_events, sizeof(io_event), (size_t) fd);
assert(i != NULL);
return i;
}
#ifdef IO_USE_DEVPOLL
static int
io_dispatch_devpoll(struct timeval *tv)
{
struct dvpoll dvp;
time_t sec = tv->tv_sec * 1000;
int i, ret, timeout = tv->tv_usec + sec;
short what;
struct pollfd p[MAX_EVENTS];
if (timeout < 0)
timeout = 1000;
dvp.dp_timeout = timeout;
dvp.dp_nfds = MAX_EVENTS;
dvp.dp_fds = p;
ret = ioctl(io_masterfd, DP_POLL, &dvp);
for (i=0; i < ret ; i++) {
what = 0;
if (p[i].revents & (POLLIN|POLLPRI))
what = IO_WANTREAD;
if (p[i].revents & POLLOUT)
what |= IO_WANTWRITE;
if (p[i].revents && !what) {
/* other flag is set, probably POLLERR */
what = IO_ERROR;
}
io_docallback(p[i].fd, what);
}
return ret;
}
static bool
io_event_change_devpoll(int fd, short what)
{
struct pollfd p;
p.events = 0;
if (what & IO_WANTREAD)
p.events = POLLIN | POLLPRI;
if (what & IO_WANTWRITE)
p.events |= POLLOUT;
p.fd = fd;
return write(io_masterfd, &p, sizeof p) == (ssize_t)sizeof p;
}
static void
io_close_devpoll(int fd)
{
struct pollfd p;
p.events = POLLREMOVE;
p.fd = fd;
write(io_masterfd, &p, sizeof p);
}
static void
io_library_init_devpoll(unsigned int eventsize)
{
io_masterfd = open("/dev/poll", O_RDWR);
if (io_masterfd >= 0)
library_initialized = true;
Log(LOG_INFO, "IO subsystem: /dev/poll (initial maxfd %u, masterfd %d).",
eventsize, io_masterfd);
}
#else
static inline void
io_close_devpoll(int UNUSED x)
{ /* NOTHING */ }
static inline void
io_library_init_devpoll(unsigned int UNUSED ev)
{ /* NOTHING */ }
#endif
#ifdef IO_USE_POLL
static int
io_dispatch_poll(struct timeval *tv)
{
time_t sec = tv->tv_sec * 1000;
int i, ret, timeout = tv->tv_usec + sec;
int fds_ready;
short what;
struct pollfd *p = array_start(&pollfds);
if (timeout < 0)
timeout = 1000;
ret = poll(p, poll_maxfd + 1, timeout);
if (ret <= 0)
return ret;
fds_ready = ret;
for (i=0; i <= poll_maxfd; i++) {
what = 0;
if (p[i].revents & (POLLIN|POLLPRI))
what = IO_WANTREAD;
if (p[i].revents & POLLOUT)
what |= IO_WANTWRITE;
if (p[i].revents && !what) {
/* other flag is set, probably POLLERR */
what = IO_ERROR;
}
if (what) {
fds_ready--;
io_docallback(i, what);
}
if (fds_ready <= 0)
break;
}
return ret;
}
static bool
io_event_change_poll(int fd, short what)
{
struct pollfd *p;
short events = 0;
if (what & IO_WANTREAD)
events = POLLIN | POLLPRI;
if (what & IO_WANTWRITE)
events |= POLLOUT;
p = array_alloc(&pollfds, sizeof *p, fd);
if (p) {
p->events = events;
p->fd = fd;
if (fd > poll_maxfd)
poll_maxfd = fd;
}
return p != NULL;
}
static void
io_close_poll(int fd)
{
struct pollfd *p;
p = array_get(&pollfds, sizeof *p, fd);
if (!p) return;
p->fd = -1;
if (fd == poll_maxfd) {
while (poll_maxfd > 0) {
--poll_maxfd;
p = array_get(&pollfds, sizeof *p, poll_maxfd);
if (p && p->fd >= 0)
break;
}
}
}
static void
io_library_init_poll(unsigned int eventsize)
{
struct pollfd *p;
array_init(&pollfds);
poll_maxfd = 0;
Log(LOG_INFO, "IO subsystem: poll (initial maxfd %u).",
eventsize);
p = array_alloc(&pollfds, sizeof(struct pollfd), eventsize);
if (p) {
unsigned i;
p = array_start(&pollfds);
for (i = 0; i < eventsize; i++)
p[i].fd = -1;
library_initialized = true;
}
}
#else
static inline void
io_close_poll(int UNUSED x)
{ /* NOTHING */ }
static inline void
io_library_init_poll(unsigned int UNUSED ev)
{ /* NOTHING */ }
#endif
#ifdef IO_USE_SELECT
static int
io_dispatch_select(struct timeval *tv)
{
fd_set readers_tmp;
fd_set writers_tmp;
short what;
int ret, i;
int fds_ready;
readers_tmp = readers;
writers_tmp = writers;
ret = select(select_maxfd + 1, &readers_tmp, &writers_tmp, NULL, tv);
if (ret <= 0)
return ret;
fds_ready = ret;
for (i = 0; i <= select_maxfd; i++) {
what = 0;
if (FD_ISSET(i, &readers_tmp)) {
what = IO_WANTREAD;
fds_ready--;
}
if (FD_ISSET(i, &writers_tmp)) {
what |= IO_WANTWRITE;
fds_ready--;
}
if (what)
io_docallback(i, what);
if (fds_ready <= 0)
break;
}
return ret;
}
static void
io_library_init_select(unsigned int eventsize)
{
if (library_initialized)
return;
Log(LOG_INFO, "IO subsystem: select (initial maxfd %u).",
eventsize);
FD_ZERO(&readers);
FD_ZERO(&writers);
#ifdef FD_SETSIZE
if (Conf_MaxConnections >= (int)FD_SETSIZE) {
Log(LOG_WARNING,
"MaxConnections (%d) exceeds limit (%u), changed MaxConnections to %u.",
Conf_MaxConnections, FD_SETSIZE, FD_SETSIZE - 1);
Conf_MaxConnections = FD_SETSIZE - 1;
}
#else
Log(LOG_WARNING,
"FD_SETSIZE undefined, don't know how many descriptors select() can handle on your platform ...");
#endif /* FD_SETSIZE */
library_initialized = true;
}
static void
io_close_select(int fd)
{
io_event *i;
if (io_masterfd >= 0) /* Are we using epoll()? */
return;
FD_CLR(fd, &writers);
FD_CLR(fd, &readers);
i = io_event_get(fd);
if (!i) return;
if (fd == select_maxfd) {
while (select_maxfd>0) {
--select_maxfd; /* find largest fd */
i = io_event_get(select_maxfd);
if (i && i->callback) break;
}
}
}
#else
static inline void
io_library_init_select(int UNUSED x)
{ /* NOTHING */ }
static inline void
io_close_select(int UNUSED x)
{ /* NOTHING */ }
#endif /* SELECT */
#ifdef IO_USE_EPOLL
static bool
io_event_change_epoll(int fd, short what, const int action)
{
struct epoll_event ev = { 0, {0} };
ev.data.fd = fd;
if (what & IO_WANTREAD)
ev.events = EPOLLIN | EPOLLPRI;
if (what & IO_WANTWRITE)
ev.events |= EPOLLOUT;
return epoll_ctl(io_masterfd, action, fd, &ev) == 0;
}
static int
io_dispatch_epoll(struct timeval *tv)
{
time_t sec = tv->tv_sec * 1000;
int i, ret, timeout = tv->tv_usec + sec;
struct epoll_event epoll_ev[MAX_EVENTS];
short type;
if (timeout < 0)
timeout = 1000;
ret = epoll_wait(io_masterfd, epoll_ev, MAX_EVENTS, timeout);
for (i = 0; i < ret; i++) {
type = 0;
if (epoll_ev[i].events & (EPOLLERR | EPOLLHUP))
type = IO_ERROR;
if (epoll_ev[i].events & (EPOLLIN | EPOLLPRI))
type |= IO_WANTREAD;
if (epoll_ev[i].events & EPOLLOUT)
type |= IO_WANTWRITE;
io_docallback(epoll_ev[i].data.fd, type);
}
return ret;
}
static void
io_library_init_epoll(unsigned int eventsize)
{
int ecreate_hint = (int)eventsize;
if (ecreate_hint <= 0)
ecreate_hint = 128;
io_masterfd = epoll_create(ecreate_hint);
if (io_masterfd >= 0) {
library_initialized = true;
Log(LOG_INFO,
"IO subsystem: epoll (hint size %d, initial maxfd %u, masterfd %d).",
ecreate_hint, eventsize, io_masterfd);
return;
}
#ifdef IO_USE_SELECT
Log(LOG_INFO, "Can't initialize epoll() IO interface, falling back to select() ...");
#endif
}
#else
static inline void
io_library_init_epoll(unsigned int UNUSED ev)
{ /* NOTHING */ }
#endif /* IO_USE_EPOLL */
#ifdef IO_USE_KQUEUE
static bool
io_event_kqueue_commit_cache(void)
{
struct kevent *events;
bool ret;
int len = (int) array_length(&io_evcache, sizeof (struct kevent));
if (!len) /* nothing to do */
return true;
assert(len>0);
if (len < 0) {
array_free(&io_evcache);
return false;
}
events = array_start(&io_evcache);
assert(events != NULL);
ret = kevent(io_masterfd, events, len, NULL, 0, NULL) == 0;
if (ret)
array_trunc(&io_evcache);
return ret;
}
static bool
io_event_change_kqueue(int fd, short what, const int action)
{
struct kevent kev;
bool ret = true;
if (what & IO_WANTREAD) {
EV_SET(&kev, fd, EVFILT_READ, action, 0, 0, 0);
ret = array_catb(&io_evcache, (char*) &kev, sizeof (kev));
if (!ret)
ret = kevent(io_masterfd, &kev,1, NULL, 0, NULL) == 0;
}
if (ret && (what & IO_WANTWRITE)) {
EV_SET(&kev, fd, EVFILT_WRITE, action, 0, 0, 0);
ret = array_catb(&io_evcache, (char*) &kev, sizeof (kev));
if (!ret)
ret = kevent(io_masterfd, &kev, 1, NULL, 0, NULL) == 0;
}
if (array_length(&io_evcache, sizeof kev) >= 100)
io_event_kqueue_commit_cache();
return ret;
}
static int
io_dispatch_kqueue(struct timeval *tv)
{
int i, ret;
struct kevent kev[MAX_EVENTS];
struct kevent *newevents;
struct timespec ts;
int newevents_len;
ts.tv_sec = tv->tv_sec;
ts.tv_nsec = tv->tv_usec * 1000;
newevents_len = (int) array_length(&io_evcache, sizeof (struct kevent));
newevents = (newevents_len > 0) ? array_start(&io_evcache) : NULL;
assert(newevents_len >= 0);
ret = kevent(io_masterfd, newevents, newevents_len, kev, MAX_EVENTS, &ts);
if (newevents && ret != -1)
array_trunc(&io_evcache);
for (i = 0; i < ret; i++) {
io_debug("dispatch_kqueue: fd, kev.flags", (int)kev[i].ident, kev[i].flags);
if (kev[i].flags & (EV_EOF|EV_ERROR)) {
if (kev[i].flags & EV_ERROR)
Log(LOG_ERR, "kevent fd %d: EV_ERROR (%s)",
(int)kev[i].ident, strerror((int)kev[i].data));
io_docallback((int)kev[i].ident, IO_ERROR);
continue;
}
switch (kev[i].filter) {
case EVFILT_READ:
io_docallback((int)kev[i].ident, IO_WANTREAD);
break;
case EVFILT_WRITE:
io_docallback((int)kev[i].ident, IO_WANTWRITE);
break;
default:
LogDebug("Unknown kev.filter number %d for fd %d",
kev[i].filter, kev[i].ident);
/* Fall through */
case EV_ERROR:
io_docallback((int)kev[i].ident, IO_ERROR);
break;
}
}
return ret;
}
static void
io_library_init_kqueue(unsigned int eventsize)
{
io_masterfd = kqueue();
Log(LOG_INFO,
"IO subsystem: kqueue (initial maxfd %u, masterfd %d).",
eventsize, io_masterfd);
if (io_masterfd >= 0)
library_initialized = true;
}
#else
static inline void
io_library_init_kqueue(unsigned int UNUSED ev)
{ /* NOTHING */ }
#endif
bool
io_library_init(unsigned int eventsize)
{
if (library_initialized)
return true;
if ((eventsize > 0) && !array_alloc(&io_events, sizeof(io_event), (size_t)eventsize))
eventsize = 0;
io_library_init_epoll(eventsize);
io_library_init_kqueue(eventsize);
io_library_init_devpoll(eventsize);
io_library_init_poll(eventsize);
io_library_init_select(eventsize);
return library_initialized;
}
void
io_library_shutdown(void)
{
#ifdef IO_USE_SELECT
FD_ZERO(&readers);
FD_ZERO(&writers);
#endif
#if defined(IO_USE_EPOLL) || defined(IO_USE_KQUEUE) || defined(IO_USE_DEVPOLL)
if (io_masterfd >= 0)
close(io_masterfd);
io_masterfd = -1;
#endif
#ifdef IO_USE_KQUEUE
array_free(&io_evcache);
#endif
library_initialized = false;
}
bool
io_event_setcb(int fd, void (*cbfunc) (int, short))
{
io_event *i = io_event_get(fd);
if (!i)
return false;
i->callback = cbfunc;
return true;
}
static bool
backend_create_ev(int fd, short what)
{
bool ret;
#ifdef IO_USE_DEVPOLL
ret = io_event_change_devpoll(fd, what);
#endif
#ifdef IO_USE_POLL
ret = io_event_change_poll(fd, what);
#endif
#ifdef IO_USE_EPOLL
ret = io_event_change_epoll(fd, what, EPOLL_CTL_ADD);
#endif
#ifdef IO_USE_KQUEUE
ret = io_event_change_kqueue(fd, what, EV_ADD|EV_ENABLE);
#endif
#ifdef IO_USE_SELECT
if (io_masterfd < 0)
ret = io_event_add(fd, what);
#endif
return ret;
}
bool
io_event_create(int fd, short what, void (*cbfunc) (int, short))
{
bool ret;
io_event *i;
assert(fd >= 0);
#if defined(IO_USE_SELECT) && defined(FD_SETSIZE)
if (io_masterfd < 0 && fd >= FD_SETSIZE) {
Log(LOG_ERR,
"fd %d exceeds FD_SETSIZE (%u) (select can't handle more file descriptors)",
fd, FD_SETSIZE);
return false;
}
#endif
i = (io_event *) array_alloc(&io_events, sizeof(io_event), (size_t) fd);
if (!i) {
Log(LOG_WARNING,
"array_alloc failed: could not allocate space for %d io_event structures",
fd);
return false;
}
i->callback = cbfunc;
i->what = 0;
ret = backend_create_ev(fd, what);
if (ret)
i->what = what;
return ret;
}
bool
io_event_add(int fd, short what)
{
io_event *i = io_event_get(fd);
if (!i) return false;
if ((i->what & what) == what) /* event type is already registered */
return true;
io_debug("io_event_add: fd, what", fd, what);
i->what |= what;
#ifdef IO_USE_EPOLL
if (io_masterfd >= 0)
return io_event_change_epoll(fd, i->what, EPOLL_CTL_MOD);
#endif
#ifdef IO_USE_KQUEUE
return io_event_change_kqueue(fd, what, EV_ADD | EV_ENABLE);
#endif
#ifdef IO_USE_DEVPOLL
return io_event_change_devpoll(fd, i->what);
#endif
#ifdef IO_USE_POLL
return io_event_change_poll(fd, i->what);
#endif
#ifdef IO_USE_SELECT
if (fd > select_maxfd)
select_maxfd = fd;
if (what & IO_WANTREAD)
FD_SET(fd, &readers);
if (what & IO_WANTWRITE)
FD_SET(fd, &writers);
return true;
#endif
return false;
}
bool
io_setnonblock(int fd)
{
int flags = fcntl(fd, F_GETFL);
if (flags == -1)
return false;
#ifndef O_NONBLOCK
#define O_NONBLOCK O_NDELAY
#endif
flags |= O_NONBLOCK;
return fcntl(fd, F_SETFL, flags) == 0;
}
bool
io_setcloexec(int fd)
{
int flags = fcntl(fd, F_GETFD);
if (flags == -1)
return false;
#ifdef FD_CLOEXEC
flags |= FD_CLOEXEC;
#endif
return fcntl(fd, F_SETFD, flags) == 0;
}
bool
io_close(int fd)
{
io_event *i;
i = io_event_get(fd);
#ifdef IO_USE_KQUEUE
if (array_length(&io_evcache, sizeof (struct kevent))) /* pending data in cache? */
io_event_kqueue_commit_cache();
/* both kqueue and epoll remove fd from all sets automatically on the last close
* of the descriptor. since we don't know if this is the last close we'll have
* to remove the set explicitly. */
if (i) {
io_event_change_kqueue(fd, i->what, EV_DELETE);
io_event_kqueue_commit_cache();
}
#endif
io_close_devpoll(fd);
io_close_poll(fd);
io_close_select(fd);
#ifdef IO_USE_EPOLL
io_event_change_epoll(fd, 0, EPOLL_CTL_DEL);
#endif
if (i) {
i->callback = NULL;
i->what = 0;
}
return close(fd) == 0;
}
bool
io_event_del(int fd, short what)
{
io_event *i = io_event_get(fd);
io_debug("io_event_del: trying to delete eventtype; fd, what", fd, what);
if (!i) return false;
if (!(i->what & what)) /* event is already disabled */
return true;
i->what &= ~what;
#ifdef IO_USE_DEVPOLL
return io_event_change_devpoll(fd, i->what);
#endif
#ifdef IO_USE_POLL
return io_event_change_poll(fd, i->what);
#endif
#ifdef IO_USE_EPOLL
if (io_masterfd >= 0)
return io_event_change_epoll(fd, i->what, EPOLL_CTL_MOD);
#endif
#ifdef IO_USE_KQUEUE
return io_event_change_kqueue(fd, what, EV_DISABLE);
#endif
#ifdef IO_USE_SELECT
if (what & IO_WANTWRITE)
FD_CLR(fd, &writers);
if (what & IO_WANTREAD)
FD_CLR(fd, &readers);
return true;
#endif
return false;
}
int
io_dispatch(struct timeval *tv)
{
#ifdef IO_USE_EPOLL
if (io_masterfd >= 0)
return io_dispatch_epoll(tv);
#endif
#ifdef IO_USE_SELECT
return io_dispatch_select(tv);
#endif
#ifdef IO_USE_KQUEUE
return io_dispatch_kqueue(tv);
#endif
#ifdef IO_USE_DEVPOLL
return io_dispatch_devpoll(tv);
#endif
#ifdef IO_USE_POLL
return io_dispatch_poll(tv);
#endif
return -1;
}
/* call the callback function inside the struct matching fd */
static void
io_docallback(int fd, short what)
{
io_event *i = io_event_get(fd);
io_debug("io_docallback; fd, what", fd, what);
if (i->callback) { /* callback might be NULL if a previous callback function
called io_close on this fd */
i->callback(fd, (what & IO_ERROR) ? i->what : what);
}
/* if error indicator is set, we return the event(s) that were registered */
}
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to io.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [local] / ircnowd / src / ngircd