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-rw-r--r--lib/util/event_select.c250
1 files changed, 250 insertions, 0 deletions
diff --git a/lib/util/event_select.c b/lib/util/event_select.c
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+++ b/lib/util/event_select.c
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+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2013-2015 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * 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.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/param.h> /* for howmany() on Linux */
+#include <sys/time.h>
+#ifdef HAVE_SYS_SYSMACROS_H
+# include <sys/sysmacros.h> /* for howmany() on Solaris */
+#endif
+#ifdef HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif /* HAVE_SYS_SELECT_H */
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include <sudo_compat.h>
+#include <sudo_util.h>
+#include <sudo_fatal.h>
+#include <sudo_debug.h>
+#include <sudo_event.h>
+
+int
+sudo_ev_base_alloc_impl(struct sudo_event_base *base)
+{
+ debug_decl(sudo_ev_base_alloc_impl, SUDO_DEBUG_EVENT);
+
+ base->maxfd = NFDBITS - 1;
+ base->readfds_in = calloc(1, sizeof(fd_mask));
+ base->writefds_in = calloc(1, sizeof(fd_mask));
+ base->readfds_out = calloc(1, sizeof(fd_mask));
+ base->writefds_out = calloc(1, sizeof(fd_mask));
+
+ if (base->readfds_in == NULL || base->writefds_in == NULL ||
+ base->readfds_out == NULL || base->writefds_out == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "%s: unable to calloc(1, %zu)", __func__, sizeof(fd_mask));
+ sudo_ev_base_free_impl(base);
+ debug_return_int(-1);
+ }
+ debug_return_int(0);
+}
+
+void
+sudo_ev_base_free_impl(struct sudo_event_base *base)
+{
+ debug_decl(sudo_ev_base_free_impl, SUDO_DEBUG_EVENT);
+ free(base->readfds_in);
+ free(base->writefds_in);
+ free(base->readfds_out);
+ free(base->writefds_out);
+ debug_return;
+}
+
+int
+sudo_ev_add_impl(struct sudo_event_base *base, struct sudo_event *ev)
+{
+ debug_decl(sudo_ev_add_impl, SUDO_DEBUG_EVENT);
+
+ /* If out of space in fd sets, realloc. */
+ if (ev->fd > base->maxfd) {
+ const int o = (base->maxfd + 1) / NFDBITS;
+ const int n = howmany(ev->fd + 1, NFDBITS);
+ const size_t used_bytes = (size_t)o * sizeof(fd_mask);
+ const size_t new_bytes = (size_t)(n - o) * sizeof(fd_mask);
+ fd_set *rfds_in, *wfds_in, *rfds_out, *wfds_out;
+
+ rfds_in = reallocarray(base->readfds_in, (size_t)n, sizeof(fd_mask));
+ wfds_in = reallocarray(base->writefds_in, (size_t)n, sizeof(fd_mask));
+ rfds_out = reallocarray(base->readfds_out, (size_t)n, sizeof(fd_mask));
+ wfds_out = reallocarray(base->writefds_out, (size_t)n, sizeof(fd_mask));
+ if (rfds_in == NULL || wfds_in == NULL ||
+ rfds_out == NULL || wfds_out == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "%s: unable to reallocarray(%d, %zu)",
+ __func__, n, sizeof(fd_mask));
+ free(rfds_in);
+ free(wfds_in);
+ free(rfds_out);
+ free(wfds_out);
+ debug_return_int(-1);
+ }
+
+ /* Clear newly allocated space. */
+ memset((char *)rfds_in + used_bytes, 0, new_bytes);
+ memset((char *)wfds_in + used_bytes, 0, new_bytes);
+ memset((char *)rfds_out + used_bytes, 0, new_bytes);
+ memset((char *)wfds_out + used_bytes, 0, new_bytes);
+
+ /* Update base. */
+ base->readfds_in = rfds_in;
+ base->writefds_in = wfds_in;
+ base->readfds_out = rfds_out;
+ base->writefds_out = wfds_out;
+ base->maxfd = (n * NFDBITS) - 1;
+ }
+
+ /* Set events and adjust high fd as needed. */
+ if (ISSET(ev->events, SUDO_EV_READ)) {
+ sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: added fd %d to readfs",
+ __func__, ev->fd);
+ FD_SET(ev->fd, (fd_set *)base->readfds_in);
+ }
+ if (ISSET(ev->events, SUDO_EV_WRITE)) {
+ sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: added fd %d to writefds",
+ __func__, ev->fd);
+ FD_SET(ev->fd, (fd_set *)base->writefds_in);
+ }
+ if (ev->fd > base->highfd)
+ base->highfd = ev->fd;
+
+ debug_return_int(0);
+}
+
+int
+sudo_ev_del_impl(struct sudo_event_base *base, struct sudo_event *ev)
+{
+ debug_decl(sudo_ev_del_impl, SUDO_DEBUG_EVENT);
+
+ /* Remove from readfds and writefds and adjust high fd. */
+ if (ISSET(ev->events, SUDO_EV_READ)) {
+ sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: removed fd %d from readfds",
+ __func__, ev->fd);
+ FD_CLR(ev->fd, (fd_set *)base->readfds_in);
+ }
+ if (ISSET(ev->events, SUDO_EV_WRITE)) {
+ sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: removed fd %d from writefds",
+ __func__, ev->fd);
+ FD_CLR(ev->fd, (fd_set *)base->writefds_in);
+ }
+ if (base->highfd == ev->fd) {
+ for (;;) {
+ if (FD_ISSET(base->highfd, (fd_set *)base->readfds_in) ||
+ FD_ISSET(base->highfd, (fd_set *)base->writefds_in))
+ break;
+ if (--base->highfd < 0)
+ break;
+ }
+ }
+
+ debug_return_int(0);
+}
+
+#ifdef HAVE_PSELECT
+static int
+sudo_ev_select(int nfds, fd_set *readfds, fd_set *writefds,
+ fd_set *exceptfds, const struct timespec *timeout)
+{
+ return pselect(nfds, readfds, writefds, exceptfds, timeout, NULL);
+}
+#else
+static int
+sudo_ev_select(int nfds, fd_set *readfds, fd_set *writefds,
+ fd_set *exceptfds, const struct timespec *timeout)
+{
+ struct timeval tvbuf, *tv = NULL;
+
+ if (timeout != NULL) {
+ TIMESPEC_TO_TIMEVAL(&tvbuf, timeout);
+ tv = &tvbuf;
+ }
+ return select(nfds, readfds, writefds, exceptfds, tv);
+}
+#endif /* HAVE_PSELECT */
+
+int
+sudo_ev_scan_impl(struct sudo_event_base *base, unsigned int flags)
+{
+ struct timespec now, ts, *timeout;
+ struct sudo_event *ev;
+ size_t setsize;
+ int nready;
+ debug_decl(sudo_ev_loop, SUDO_DEBUG_EVENT);
+
+ if ((ev = TAILQ_FIRST(&base->timeouts)) != NULL) {
+ sudo_gettime_mono(&now);
+ sudo_timespecsub(&ev->timeout, &now, &ts);
+ if (ts.tv_sec < 0)
+ sudo_timespecclear(&ts);
+ timeout = &ts;
+ } else {
+ if (ISSET(flags, SUDO_EVLOOP_NONBLOCK)) {
+ sudo_timespecclear(&ts);
+ timeout = &ts;
+ } else {
+ timeout = NULL;
+ }
+ }
+
+ /* select() overwrites readfds/writefds so make a copy. */
+ setsize = (size_t)howmany(base->highfd + 1, NFDBITS) * sizeof(fd_mask);
+ memcpy(base->readfds_out, base->readfds_in, setsize);
+ memcpy(base->writefds_out, base->writefds_in, setsize);
+
+ sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: select high fd %d",
+ __func__, base->highfd);
+ nready = sudo_ev_select(base->highfd + 1, base->readfds_out,
+ base->writefds_out, NULL, timeout);
+ sudo_debug_printf(SUDO_DEBUG_INFO, "%s: %d fds ready", __func__, nready);
+ switch (nready) {
+ case -1:
+ /* Error or interrupted by signal. */
+ break;
+ case 0:
+ /* Front end will activate timeout events. */
+ break;
+ default:
+ /* Activate each I/O event that fired. */
+ TAILQ_FOREACH(ev, &base->events, entries) {
+ if (ev->fd >= 0) {
+ short what = 0;
+ if (FD_ISSET(ev->fd, (fd_set *)base->readfds_out))
+ what |= (ev->events & SUDO_EV_READ);
+ if (FD_ISSET(ev->fd, (fd_set *)base->writefds_out))
+ what |= (ev->events & SUDO_EV_WRITE);
+ if (what != 0) {
+ /* Make event active. */
+ sudo_debug_printf(SUDO_DEBUG_DEBUG,
+ "%s: selected fd %d, events %hd, activating %p",
+ __func__, ev->fd, what, ev);
+ ev->revents = what;
+ sudo_ev_activate(base, ev);
+ }
+ }
+ }
+ break;
+ }
+ debug_return_int(nready);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 05:41:10 +0000