upstream: switch mainloop from select(2) to poll(2); ok deraadt@

OpenBSD-Commit-ID: 37645419a330037d297f6f0adc3b3663e7ae7b2e

1 files changed, 19 insertions, 23 deletions

diff --git a/ssh-pkcs11-helper.c b/ssh-pkcs11-helper.c
index c7dfea279..97fb1212c 100644
--- a/ssh-pkcs11-helper.c
+++ b/ssh-pkcs11-helper.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-pkcs11-helper.c,v 1.16 2019/01/21 12:53:35 djm Exp $ */
+/* $OpenBSD: ssh-pkcs11-helper.c,v 1.17 2019/01/23 02:01:10 djm Exp $ */
 /*
  * Copyright (c) 2010 Markus Friedl.  All rights reserved.
  *
@@ -24,10 +24,11 @@
 
 #include "openbsd-compat/sys-queue.h"
 
+#include <errno.h>
+#include <poll.h>
 #include <stdarg.h>
 #include <string.h>
 #include <unistd.h>
-#include <errno.h>
 
 #include "xmalloc.h"
 #include "sshbuf.h"
@@ -311,14 +312,13 @@ cleanup_exit(int i)
 int
 main(int argc, char **argv)
 {
-        fd_set *rset, *wset;
         int r, ch, in, out, max, log_stderr = 0;
-        ssize_t len, olen, set_size;
+        ssize_t len;
         SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
         LogLevel log_level = SYSLOG_LEVEL_ERROR;
         char buf[4*4096];
-
         extern char *__progname;
+        struct pollfd pfd[2];
 
         ssh_malloc_init();      /* must be called before any mallocs */
         __progname = ssh_get_progname(argv[0]);
@@ -360,13 +360,10 @@ main(int argc, char **argv)
         if ((oqueue = sshbuf_new()) == NULL)
                 fatal("%s: sshbuf_new failed", __func__);
 
-        set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
-        rset = xmalloc(set_size);
-        wset = xmalloc(set_size);
-
-        for (;;) {
-                memset(rset, 0, set_size);
-                memset(wset, 0, set_size);
+        while (1) {
+                memset(pfd, 0, sizeof(pfd));
+                pfd[0].fd = in;
+                pfd[1].fd = out;
 
                 /*
                  * Ensure that we can read a full buffer and handle
@@ -375,23 +372,21 @@ main(int argc, char **argv)
                  */
                 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
                     (r = sshbuf_check_reserve(oqueue, MAX_MSG_LENGTH)) == 0)
-                        FD_SET(in, rset);
+                        pfd[0].events = POLLIN;
                 else if (r != SSH_ERR_NO_BUFFER_SPACE)
                         fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-                olen = sshbuf_len(oqueue);
-                if (olen > 0)
-                        FD_SET(out, wset);
+                if (sshbuf_len(oqueue) > 0)
+                        pfd[1].events = POLLOUT;
 
-                if (select(max+1, rset, wset, NULL, NULL) < 0) {
-                        if (errno == EINTR)
+                if ((r = poll(pfd, 2, -1 /* INFTIM */)) <= 0) {
+                        if (r == 0 || errno == EINTR)
                                 continue;
-                        error("select: %s", strerror(errno));
-                        cleanup_exit(2);
+                        fatal("poll: %s", strerror(errno));
                 }
 
                 /* copy stdin to iqueue */
-                if (FD_ISSET(in, rset)) {
+                if ((pfd[0].revents & (POLLIN|POLLERR)) != 0) {
                         len = read(in, buf, sizeof buf);
                         if (len == 0) {
                                 debug("read eof");
@@ -405,8 +400,9 @@ main(int argc, char **argv)
                         }
                 }
                 /* send oqueue to stdout */
-                if (FD_ISSET(out, wset)) {
-                        len = write(out, sshbuf_ptr(oqueue), olen);
+                if ((pfd[1].revents & (POLLOUT|POLLHUP)) != 0) {
+                        len = write(out, sshbuf_ptr(oqueue),
+                            sshbuf_len(oqueue));
                         if (len < 0) {
                                 error("write: %s", strerror(errno));
                                 cleanup_exit(1);