/*
- event.c -- I/O, timeout and signal event handling
- Copyright (C) 2012-2013 Guus Sliepen <guus@tinc-vpn.org>
+ event.c -- I/O, timeout, and event handling
+ Copyright (C) 2012-2022 Guus Sliepen <guus@tinc-vpn.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
#include "system.h"
-#include "dropin.h"
#include "event.h"
-#include "net.h"
-#include "utils.h"
-#include "xalloc.h"
struct timeval now;
-#ifndef HAVE_MINGW
-static fd_set readfds;
-static fd_set writefds;
-#else
-static const long READ_EVENTS = FD_READ | FD_ACCEPT | FD_CLOSE;
-static const long WRITE_EVENTS = FD_WRITE | FD_CONNECT;
-static DWORD event_count = 0;
-#endif
-static bool running;
-
static int io_compare(const io_t *a, const io_t *b) {
-#ifndef HAVE_MINGW
+#ifndef HAVE_WINDOWS
return a->fd - b->fd;
#else
- return a->event - b->event;
-#endif
-}
-static int timeout_compare(const timeout_t *a, const timeout_t *b) {
- struct timeval diff;
- timersub(&a->tv, &b->tv, &diff);
- if(diff.tv_sec < 0)
- return -1;
- if(diff.tv_sec > 0)
- return 1;
- if(diff.tv_usec < 0)
+ if(a->event < b->event) {
return -1;
- if(diff.tv_usec > 0)
- return 1;
- if(a < b)
- return -1;
- if(a > b)
+ }
+
+ if(a->event > b->event) {
return 1;
+ }
+
return 0;
+#endif
}
-static splay_tree_t io_tree = {.compare = (splay_compare_t)io_compare};
-static splay_tree_t timeout_tree = {.compare = (splay_compare_t)timeout_compare};
+static int timeout_compare(const timeout_t *a, const timeout_t *b) {
+ struct timeval diff;
+ timersub(&a->tv, &b->tv, &diff);
-void io_add(io_t *io, io_cb_t cb, void *data, int fd, int flags) {
- if(io->cb)
- return;
+ if(diff.tv_sec < 0) {
+ return -1;
+ }
- io->fd = fd;
-#ifdef HAVE_MINGW
- if (io->fd != -1) {
- io->event = WSACreateEvent();
- if (io->event == WSA_INVALID_EVENT)
- abort();
+ if(diff.tv_sec > 0) {
+ return 1;
}
- event_count++;
-#endif
- io->cb = cb;
- io->data = data;
- io->node.data = io;
- io_set(io, flags);
+ if(diff.tv_usec < 0) {
+ return -1;
+ }
- if(!splay_insert_node(&io_tree, &io->node))
- abort();
-}
+ if(diff.tv_usec > 0) {
+ return 1;
+ }
-#ifdef HAVE_MINGW
-void io_add_event(io_t *io, io_cb_t cb, void *data, WSAEVENT event) {
- io->event = event;
- io_add(io, cb, data, -1, 0);
-}
-#endif
+ uintptr_t ap = (uintptr_t)a;
+ uintptr_t bp = (uintptr_t)b;
-void io_set(io_t *io, int flags) {
- if (flags == io->flags)
- return;
- io->flags = flags;
- if (io->fd == -1)
- return;
+ if(ap < bp) {
+ return -1;
+ }
-#ifndef HAVE_MINGW
- if(flags & IO_READ)
- FD_SET(io->fd, &readfds);
- else
- FD_CLR(io->fd, &readfds);
+ if(ap > bp) {
+ return 1;
+ }
- if(flags & IO_WRITE)
- FD_SET(io->fd, &writefds);
- else
- FD_CLR(io->fd, &writefds);
-#else
- long events = 0;
- if (flags & IO_WRITE)
- events |= WRITE_EVENTS;
- if (flags & IO_READ)
- events |= READ_EVENTS;
- if (WSAEventSelect(io->fd, io->event, events) != 0)
- abort();
-#endif
+ return 0;
}
-void io_del(io_t *io) {
- if(!io->cb)
- return;
-
- io_set(io, 0);
-#ifdef HAVE_MINGW
- if (io->fd != -1 && WSACloseEvent(io->event) == FALSE)
- abort();
- event_count--;
-#endif
-
- splay_unlink_node(&io_tree, &io->node);
- io->cb = NULL;
-}
+splay_tree_t io_tree = {.compare = (splay_compare_t)io_compare};
+splay_tree_t timeout_tree = {.compare = (splay_compare_t)timeout_compare};
-void timeout_add(timeout_t *timeout, timeout_cb_t cb, void *data, struct timeval *tv) {
+void timeout_add(timeout_t *timeout, timeout_cb_t cb, void *data, const struct timeval *tv) {
timeout->cb = cb;
timeout->data = data;
timeout->node.data = timeout;
timeout_set(timeout, tv);
}
-void timeout_set(timeout_t *timeout, struct timeval *tv) {
- if(timerisset(&timeout->tv))
+void timeout_set(timeout_t *timeout, const struct timeval *tv) {
+ if(timerisset(&timeout->tv)) {
splay_unlink_node(&timeout_tree, &timeout->node);
+ }
- if(!now.tv_sec)
+ if(!now.tv_sec) {
gettimeofday(&now, NULL);
+ }
timeradd(&now, tv, &timeout->tv);
- if(!splay_insert_node(&timeout_tree, &timeout->node))
+ if(!splay_insert_node(&timeout_tree, &timeout->node)) {
abort();
+ }
}
void timeout_del(timeout_t *timeout) {
- if(!timeout->cb)
+ if(!timeout->cb) {
return;
+ }
splay_unlink_node(&timeout_tree, &timeout->node);
timeout->cb = 0;
- timeout->tv = (struct timeval){0, 0};
-}
-
-#ifndef HAVE_MINGW
-static int signal_compare(const signal_t *a, const signal_t *b) {
- return a->signum - b->signum;
-}
-
-static io_t signalio;
-static int pipefd[2] = {-1, -1};
-static splay_tree_t signal_tree = {.compare = (splay_compare_t)signal_compare};
-
-static void signal_handler(int signum) {
- unsigned char num = signum;
- write(pipefd[1], &num, 1);
-}
-
-static void signalio_handler(void *data, int flags) {
- unsigned char signum;
- if(read(pipefd[0], &signum, 1) != 1)
- return;
-
- signal_t *sig = splay_search(&signal_tree, &((signal_t){.signum = signum}));
- if(sig)
- sig->cb(sig->data);
-}
-
-static void pipe_init(void) {
- if(!pipe(pipefd))
- io_add(&signalio, signalio_handler, NULL, pipefd[0], IO_READ);
-}
-
-void signal_add(signal_t *sig, signal_cb_t cb, void *data, int signum) {
- if(sig->cb)
- return;
-
- sig->cb = cb;
- sig->data = data;
- sig->signum = signum;
- sig->node.data = sig;
-
- if(pipefd[0] == -1)
- pipe_init();
-
- signal(sig->signum, signal_handler);
-
- if(!splay_insert_node(&signal_tree, &sig->node))
- abort();
-}
-
-void signal_del(signal_t *sig) {
- if(!sig->cb)
- return;
-
- signal(sig->signum, SIG_DFL);
-
- splay_unlink_node(&signal_tree, &sig->node);
- sig->cb = NULL;
+ timeout->tv = (struct timeval) {
+ 0, 0
+ };
}
-#endif
-static struct timeval * get_time_remaining(struct timeval *diff) {
+struct timeval *timeout_execute(struct timeval *diff) {
gettimeofday(&now, NULL);
struct timeval *tv = NULL;
if(diff->tv_sec < 0) {
timeout->cb(timeout->data);
- if(timercmp(&timeout->tv, &now, <))
+
+ if(timercmp(&timeout->tv, &now, <)) {
timeout_del(timeout);
+ }
} else {
tv = diff;
break;
return tv;
}
-
-bool event_loop(void) {
- running = true;
-
-#ifndef HAVE_MINGW
- fd_set readable;
- fd_set writable;
-
- while(running) {
- struct timeval diff;
- struct timeval *tv = get_time_remaining(&diff);
- memcpy(&readable, &readfds, sizeof readable);
- memcpy(&writable, &writefds, sizeof writable);
-
- int fds = 0;
-
- if(io_tree.tail) {
- io_t *last = io_tree.tail->data;
- fds = last->fd + 1;
- }
-
- int n = select(fds, &readable, &writable, NULL, tv);
-
- if(n < 0) {
- if(sockwouldblock(sockerrno))
- continue;
- else
- return false;
- }
-
- if(!n)
- continue;
-
- for splay_each(io_t, io, &io_tree) {
- if(FD_ISSET(io->fd, &writable))
- io->cb(io->data, IO_WRITE);
- else if(FD_ISSET(io->fd, &readable))
- io->cb(io->data, IO_READ);
- else
- continue;
-
- /*
- There are scenarios in which the callback will remove another io_t from the tree
- (e.g. closing a double connection). Since splay_each does not support that, we
- need to exit the loop now. That's okay, since any remaining events will get picked
- up by the next select() call.
- */
- break;
- }
- }
-#else
- while (running) {
- struct timeval diff;
- struct timeval *tv = get_time_remaining(&diff);
- DWORD timeout_ms = tv ? (tv->tv_sec * 1000 + tv->tv_usec / 1000 + 1) : WSA_INFINITE;
-
- if (!event_count) {
- Sleep(timeout_ms);
- continue;
- }
-
- /*
- For some reason, Microsoft decided to make the FD_WRITE event edge-triggered instead of level-triggered,
- which is the opposite of what select() does. In practice, that means that if a FD_WRITE event triggers,
- it will never trigger again until a send() returns EWOULDBLOCK. Since the semantics of this event loop
- is that write events are level-triggered (i.e. they continue firing until the socket is full), we need
- to emulate these semantics by making sure we fire each IO_WRITE that is still writeable.
-
- Note that technically FD_CLOSE has the same problem, but it's okay because user code does not rely on
- this event being fired again if ignored.
- */
- io_t* writeable_io = NULL;
- for splay_each(io_t, io, &io_tree)
- if (io->flags & IO_WRITE && send(io->fd, NULL, 0, 0) == 0) {
- writeable_io = io;
- break;
- }
- if (writeable_io) {
- writeable_io->cb(writeable_io->data, IO_WRITE);
- continue;
- }
-
- WSAEVENT* events = xmalloc(event_count * sizeof(*events));
- DWORD event_index = 0;
- for splay_each(io_t, io, &io_tree) {
- events[event_index] = io->event;
- event_index++;
- }
-
- DWORD result = WSAWaitForMultipleEvents(event_count, events, FALSE, timeout_ms, FALSE);
-
- WSAEVENT event;
- if (result >= WSA_WAIT_EVENT_0 && result < WSA_WAIT_EVENT_0 + event_count)
- event = events[result - WSA_WAIT_EVENT_0];
- free(events);
- if (result == WSA_WAIT_TIMEOUT)
- continue;
- if (result < WSA_WAIT_EVENT_0 || result >= WSA_WAIT_EVENT_0 + event_count)
- return false;
-
- io_t *io = splay_search(&io_tree, &((io_t){.event = event}));
- if (!io)
- abort();
-
- if (io->fd == -1) {
- io->cb(io->data, 0);
- } else {
- WSANETWORKEVENTS network_events;
- if (WSAEnumNetworkEvents(io->fd, io->event, &network_events) != 0)
- return false;
- if (network_events.lNetworkEvents & READ_EVENTS)
- io->cb(io->data, IO_READ);
- /*
- The fd might be available for write too. However, if we already fired the read callback, that
- callback might have deleted the io (e.g. through terminate_connection()), so we can't fire the
- write callback here. Instead, we loop back and let the writable io loop above handle it.
- */
- }
- }
-#endif
-
- return true;
-}
-
-void event_exit(void) {
- running = false;
-}
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