David Phillips' FD_SETSIZE fix

1 files changed, 231 insertions, 0 deletions

diff --git a/lib/select.c b/lib/select.c
new file mode 100644
index 000000000..fb337d421
--- /dev/null
+++ b/lib/select.c
@@ -0,0 +1,231 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2004, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ ***************************************************************************/
+
+#include "setup.h"
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+#ifndef HAVE_SELECT
+#error "We can't compile without select() support!"
+#endif
+
+#include "select.h"
+
+/*
+ * This is an internal function used for waiting for read or write
+ * events on single file descriptors.  It attempts to replace select()
+ * in order to avoid limits with FD_SETSIZE.
+ *
+ * Return values:
+ *   -1 = system call error
+ *    0 = timeout
+ *    CSELECT_IN | CSELECT_OUT | CSELECT_ERR
+ */
+int Curl_select(int readfd, int writefd, int timeout_ms)
+{
+#ifdef HAVE_POLL_FINE
+  struct pollfd pfd[2];
+  int num;
+  int r;
+  int ret;
+
+  num = 0;
+  if (readfd != CURL_SOCKET_BAD) {
+    pfd[num].fd = readfd;
+    pfd[num].events = POLLIN;
+    num++;
+  }
+  if (writefd != CURL_SOCKET_BAD) {
+    pfd[num].fd = writefd;
+    pfd[num].events = POLLOUT;
+    num++;
+  }
+
+  r = poll(pfd, num, timeout_ms);
+
+  if (r < 0)
+    return -1;
+  if (r == 0)
+    return 0;
+
+  ret = 0;
+  num = 0;
+  if (readfd != CURL_SOCKET_BAD) {
+    if (pfd[num].revents & POLLIN)
+      ret |= CSELECT_IN;
+    if (pfd[num].revents & POLLERR)
+      ret |= CSELECT_ERR;
+    num++;
+  }
+  if (writefd != CURL_SOCKET_BAD) {
+    if (pfd[num].revents & POLLOUT)
+      ret |= CSELECT_OUT;
+    if (pfd[num].revents & POLLERR)
+      ret |= CSELECT_ERR;
+  }
+
+  return ret;
+#else
+  struct timeval timeout;
+  fd_set fds_read;
+  fd_set fds_write;
+  fd_set fds_err;
+  int maxfd;
+  int r;
+  int ret;
+
+  timeout.tv_sec = timeout_ms / 1000;
+  timeout.tv_usec = (timeout_ms % 1000) * 1000;
+
+  FD_ZERO(&fds_err);
+  maxfd = -1;
+
+  FD_ZERO(&fds_read);
+  if (readfd != CURL_SOCKET_BAD) {
+    if ((readfd < 0) || (readfd >= FD_SETSIZE)) {
+      errno = EINVAL;
+      return -1;
+    }
+    FD_SET(readfd, &fds_read);
+    FD_SET(readfd, &fds_err);
+    maxfd = readfd;
+  }
+
+  FD_ZERO(&fds_write);
+  if (writefd != CURL_SOCKET_BAD) {
+    if ((writefd < 0) || (writefd >= FD_SETSIZE)) {
+      errno = EINVAL;
+      return -1;
+    }
+    FD_SET(writefd, &fds_write);
+    FD_SET(writefd, &fds_err);
+    if (writefd > maxfd)
+      maxfd = writefd;
+  }
+
+  r = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
+
+  if (r < 0)
+    return -1;
+  if (r == 0)
+    return 0;
+
+  ret = 0;
+  if (readfd != CURL_SOCKET_BAD) {
+    if (FD_ISSET(readfd, &fds_read))
+      ret |= CSELECT_IN;
+    if (FD_ISSET(readfd, &fds_err))
+      ret |= CSELECT_ERR;
+  }
+  if (writefd != CURL_SOCKET_BAD) {
+    if (FD_ISSET(writefd, &fds_write))
+      ret |= CSELECT_OUT;
+    if (FD_ISSET(writefd, &fds_err))
+      ret |= CSELECT_ERR;
+  }
+
+  return ret;
+#endif
+}
+
+/*
+ * This is a wrapper around poll().  If poll() does not exist, then
+ * select() is used instead.  An error is returned if select() is
+ * being used and a file descriptor too large for FD_SETSIZE.
+ *
+ * Return values:
+ *   -1 = system call error or fd >= FD_SETSIZE
+ *    0 = timeout
+ *    1 = number of structures with non zero revent fields
+ */
+int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms)
+{
+#ifdef HAVE_POLL_FINE
+    return poll(ufds, nfds, timeout_ms);
+#else
+  struct timeval timeout;
+  struct timeval *ptimeout;
+  fd_set fds_read;
+  fd_set fds_write;
+  fd_set fds_err;
+  int maxfd;
+  int r;
+  unsigned int i;
+
+  FD_ZERO(&fds_read);
+  FD_ZERO(&fds_write);
+  FD_ZERO(&fds_err);
+  maxfd = -1;
+
+  for (i = 0; i < nfds; i++) {
+    if (ufds[i].fd < 0)
+      continue;
+    if (ufds[i].fd >= FD_SETSIZE) {
+      errno = EINVAL;
+      return -1;
+    }
+    if (ufds[i].fd > maxfd)
+      maxfd = ufds[i].fd;
+    if (ufds[i].events & POLLIN)
+      FD_SET(ufds[i].fd, &fds_read);
+    if (ufds[i].events & POLLOUT)
+      FD_SET(ufds[i].fd, &fds_write);
+    if (ufds[i].events & POLLERR)
+      FD_SET(ufds[i].fd, &fds_err);
+  }
+
+  if (timeout_ms < 0) {
+    ptimeout = NULL;      /* wait forever */
+  } else {
+    timeout.tv_sec = timeout_ms / 1000;
+    timeout.tv_usec = (timeout_ms % 1000) * 1000;
+    ptimeout = &timeout;
+  }
+
+  r = select(maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout);
+
+  if (r < 0)
+    return -1;
+  if (r == 0)
+    return 0;
+
+  r = 0;
+  for (i = 0; i < nfds; i++) {
+    ufds[i].revents = 0;
+    if (ufds[i].fd < 0)
+      continue;
+    if (FD_ISSET(ufds[i].fd, &fds_read))
+      ufds[i].revents |= POLLIN;
+    if (FD_ISSET(ufds[i].fd, &fds_write))
+      ufds[i].revents |= POLLOUT;
+    if (FD_ISSET(ufds[i].fd, &fds_err))
+      ufds[i].revents |= POLLERR;
+    if (ufds[i].revents != 0)
+      r++;
+  }
+
+  return r;
+#endif
+}