1 files changed, 261 insertions, 0 deletions

diff --git a/lib/util/event_select.c b/lib/util/event_select.c
new file mode 100644
index 0000000..a733633
--- /dev/null
+++ b/lib/util/event_select.c
@@ -0,0 +1,261 @@
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# include "compat/stdbool.h"
+#endif /* HAVE_STDBOOL_H */
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <time.h>
+#include <unistd.h>
+#include <errno.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 = o * sizeof(fd_mask);
+	const size_t new_bytes = (n - o) * sizeof(fd_mask);
+	fd_set *rfds_in, *wfds_in, *rfds_out, *wfds_out;
+
+	rfds_in = reallocarray(base->readfds_in, n, sizeof(fd_mask));
+	wfds_in = reallocarray(base->writefds_in, n, sizeof(fd_mask));
+	rfds_out = reallocarray(base->readfds_out, n, sizeof(fd_mask));
+	wfds_out = reallocarray(base->writefds_out, 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, 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, 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, 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, base->writefds_in);
+    }
+    if (base->highfd == ev->fd) {
+	for (;;) {
+	    if (FD_ISSET(base->highfd, base->readfds_in) ||
+		FD_ISSET(base->highfd, 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, 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 = 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. */
+	debug_return_int(-1);
+    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) {
+		int what = 0;
+		if (FD_ISSET(ev->fd, base->readfds_out))
+		    what |= (ev->events & SUDO_EV_READ);
+		if (FD_ISSET(ev->fd, 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 %d, activating %p",
+			__func__, ev->fd, what, ev);
+		    ev->revents = what;
+		    sudo_ev_activate(base, ev);
+		}
+	    }
+	}
+	break;
+    }
+    debug_return_int(nready);
+}