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-rw-r--r--libcurl/src/lib/select.c578
1 files changed, 578 insertions, 0 deletions
diff --git a/libcurl/src/lib/select.c b/libcurl/src/lib/select.c
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+++ b/libcurl/src/lib/select.c
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+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2015, 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.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+#if !defined(HAVE_SELECT) && !defined(HAVE_POLL_FINE)
+#error "We can't compile without select() or poll() support."
+#endif
+
+#if defined(__BEOS__) && !defined(__HAIKU__)
+/* BeOS has FD_SET defined in socket.h */
+#include <socket.h>
+#endif
+
+#ifdef MSDOS
+#include <dos.h> /* delay() */
+#endif
+
+#ifdef __VXWORKS__
+#include <strings.h> /* bzero() in FD_SET */
+#endif
+
+#include <curl/curl.h>
+
+#include "urldata.h"
+#include "connect.h"
+#include "select.h"
+#include "warnless.h"
+
+/* Convenience local macros */
+
+#define elapsed_ms (int)curlx_tvdiff(curlx_tvnow(), initial_tv)
+
+CURL_STATIC_DEF(int, Curl_ack_eintr, 0);
+#define error_not_EINTR (Curl_ack_eintr || error != EINTR)
+
+/*
+ * Internal function used for waiting a specific amount of ms
+ * in Curl_socket_ready() and Curl_poll() when no file descriptor
+ * is provided to wait on, just being used to delay execution.
+ * WinSock select() and poll() timeout mechanisms need a valid
+ * socket descriptor in a not null file descriptor set to work.
+ * Waiting indefinitely with this function is not allowed, a
+ * zero or negative timeout value will return immediately.
+ * Timeout resolution, accuracy, as well as maximum supported
+ * value is system dependent, neither factor is a citical issue
+ * for the intended use of this function in the library.
+ *
+ * Return values:
+ * -1 = system call error, invalid timeout value, or interrupted
+ * 0 = specified timeout has elapsed
+ */
+CURL_STATIC int Curl_wait_ms(int timeout_ms)
+{
+#if !defined(MSDOS) && !defined(USE_WINSOCK) || defined(CURL_WINRT)
+#ifndef HAVE_POLL_FINE
+ struct timeval pending_tv;
+#endif
+ struct timeval initial_tv;
+ int pending_ms;
+ int error;
+#endif
+ int r = 0;
+
+ if(!timeout_ms)
+ return 0;
+ if(timeout_ms < 0) {
+ SET_SOCKERRNO(EINVAL);
+ return -1;
+ }
+#if defined(MSDOS)
+ delay(timeout_ms);
+#elif defined(USE_WINSOCK) && !defined(CURL_WINRT)
+ Sleep(timeout_ms);
+#else
+ pending_ms = timeout_ms;
+ initial_tv = curlx_tvnow();
+ do {
+#if defined(HAVE_POLL_FINE)
+ r = poll(NULL, 0, pending_ms);
+#else
+ pending_tv.tv_sec = pending_ms / 1000;
+ pending_tv.tv_usec = (pending_ms % 1000) * 1000;
+ r = select(0, NULL, NULL, NULL, &pending_tv);
+#endif /* HAVE_POLL_FINE */
+ if(r != -1)
+ break;
+ error = SOCKERRNO;
+ if(error && error_not_EINTR)
+ break;
+ pending_ms = timeout_ms - elapsed_ms;
+ if(pending_ms <= 0) {
+ r = 0; /* Simulate a "call timed out" case */
+ break;
+ }
+ } while(r == -1);
+#endif /* USE_WINSOCK */
+ if(r)
+ r = -1;
+ return r;
+}
+
+/*
+ * Wait for read or write events on a set of file descriptors. It uses poll()
+ * when a fine poll() is available, in order to avoid limits with FD_SETSIZE,
+ * otherwise select() is used. An error is returned if select() is being used
+ * and a file descriptor is too large for FD_SETSIZE.
+ *
+ * A negative timeout value makes this function wait indefinitely,
+ * unles no valid file descriptor is given, when this happens the
+ * negative timeout is ignored and the function times out immediately.
+ *
+ * Return values:
+ * -1 = system call error or fd >= FD_SETSIZE
+ * 0 = timeout
+ * [bitmask] = action as described below
+ *
+ * CURL_CSELECT_IN - first socket is readable
+ * CURL_CSELECT_IN2 - second socket is readable
+ * CURL_CSELECT_OUT - write socket is writable
+ * CURL_CSELECT_ERR - an error condition occurred
+ */
+int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
+ curl_socket_t readfd1,
+ curl_socket_t writefd, /* socket to write to */
+ long timeout_ms) /* milliseconds to wait */
+{
+#ifdef HAVE_POLL_FINE
+ struct pollfd pfd[3];
+ int num;
+#else
+ struct timeval pending_tv;
+ struct timeval *ptimeout;
+ fd_set fds_read;
+ fd_set fds_write;
+ fd_set fds_err;
+ curl_socket_t maxfd;
+#endif
+ struct timeval initial_tv = {0, 0};
+ int pending_ms = 0;
+ int error;
+ int r;
+ int ret;
+
+ if((readfd0 == CURL_SOCKET_BAD) && (readfd1 == CURL_SOCKET_BAD) &&
+ (writefd == CURL_SOCKET_BAD)) {
+ /* no sockets, just wait */
+ r = Curl_wait_ms((int)timeout_ms);
+ return r;
+ }
+
+ /* Avoid initial timestamp, avoid curlx_tvnow() call, when elapsed
+ time in this function does not need to be measured. This happens
+ when function is called with a zero timeout or a negative timeout
+ value indicating a blocking call should be performed. */
+
+ if(timeout_ms > 0) {
+ pending_ms = (int)timeout_ms;
+ initial_tv = curlx_tvnow();
+ }
+
+#ifdef HAVE_POLL_FINE
+
+ num = 0;
+ if(readfd0 != CURL_SOCKET_BAD) {
+ pfd[num].fd = readfd0;
+ pfd[num].events = POLLRDNORM|POLLIN|POLLRDBAND|POLLPRI;
+ pfd[num].revents = 0;
+ num++;
+ }
+ if(readfd1 != CURL_SOCKET_BAD) {
+ pfd[num].fd = readfd1;
+ pfd[num].events = POLLRDNORM|POLLIN|POLLRDBAND|POLLPRI;
+ pfd[num].revents = 0;
+ num++;
+ }
+ if(writefd != CURL_SOCKET_BAD) {
+ pfd[num].fd = writefd;
+ pfd[num].events = POLLWRNORM|POLLOUT;
+ pfd[num].revents = 0;
+ num++;
+ }
+
+ do {
+ if(timeout_ms < 0)
+ pending_ms = -1;
+ else if(!timeout_ms)
+ pending_ms = 0;
+ r = poll(pfd, num, pending_ms);
+ if(r != -1)
+ break;
+ error = SOCKERRNO;
+ if(error && error_not_EINTR)
+ break;
+ if(timeout_ms > 0) {
+ pending_ms = (int)(timeout_ms - elapsed_ms);
+ if(pending_ms <= 0) {
+ r = 0; /* Simulate a "call timed out" case */
+ break;
+ }
+ }
+ } while(r == -1);
+
+ if(r < 0)
+ return -1;
+ if(r == 0)
+ return 0;
+
+ ret = 0;
+ num = 0;
+ if(readfd0 != CURL_SOCKET_BAD) {
+ if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
+ ret |= CURL_CSELECT_IN;
+ if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
+ ret |= CURL_CSELECT_ERR;
+ num++;
+ }
+ if(readfd1 != CURL_SOCKET_BAD) {
+ if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
+ ret |= CURL_CSELECT_IN2;
+ if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
+ ret |= CURL_CSELECT_ERR;
+ num++;
+ }
+ if(writefd != CURL_SOCKET_BAD) {
+ if(pfd[num].revents & (POLLWRNORM|POLLOUT))
+ ret |= CURL_CSELECT_OUT;
+ if(pfd[num].revents & (POLLERR|POLLHUP|POLLNVAL))
+ ret |= CURL_CSELECT_ERR;
+ }
+
+ return ret;
+
+#else /* HAVE_POLL_FINE */
+
+ FD_ZERO(&fds_err);
+ maxfd = (curl_socket_t)-1;
+
+ FD_ZERO(&fds_read);
+ if(readfd0 != CURL_SOCKET_BAD) {
+ VERIFY_SOCK(readfd0);
+ FD_SET(readfd0, &fds_read);
+ FD_SET(readfd0, &fds_err);
+ maxfd = readfd0;
+ }
+ if(readfd1 != CURL_SOCKET_BAD) {
+ VERIFY_SOCK(readfd1);
+ FD_SET(readfd1, &fds_read);
+ FD_SET(readfd1, &fds_err);
+ if(readfd1 > maxfd)
+ maxfd = readfd1;
+ }
+
+ FD_ZERO(&fds_write);
+ if(writefd != CURL_SOCKET_BAD) {
+ VERIFY_SOCK(writefd);
+ FD_SET(writefd, &fds_write);
+ FD_SET(writefd, &fds_err);
+ if(writefd > maxfd)
+ maxfd = writefd;
+ }
+
+ ptimeout = (timeout_ms < 0) ? NULL : &pending_tv;
+
+ do {
+ if(timeout_ms > 0) {
+ pending_tv.tv_sec = pending_ms / 1000;
+ pending_tv.tv_usec = (pending_ms % 1000) * 1000;
+ }
+ else if(!timeout_ms) {
+ pending_tv.tv_sec = 0;
+ pending_tv.tv_usec = 0;
+ }
+
+ /* WinSock select() must not be called with an fd_set that contains zero
+ fd flags, or it will return WSAEINVAL. But, it also can't be called
+ with no fd_sets at all! From the documentation:
+
+ Any two of the parameters, readfds, writefds, or exceptfds, can be
+ given as null. At least one must be non-null, and any non-null
+ descriptor set must contain at least one handle to a socket.
+
+ We know that we have at least one bit set in at least two fd_sets in
+ this case, but we may have no bits set in either fds_read or fd_write,
+ so check for that and handle it. Luckily, with WinSock, we can _also_
+ ask how many bits are set on an fd_set.
+
+ It is unclear why WinSock doesn't just handle this for us instead of
+ calling this an error.
+
+ Note also that WinSock ignores the first argument, so we don't worry
+ about the fact that maxfd is computed incorrectly with WinSock (since
+ curl_socket_t is unsigned in such cases and thus -1 is the largest
+ value).
+ */
+ r = select((int)maxfd + 1,
+#ifndef USE_WINSOCK
+ &fds_read,
+ &fds_write,
+#else
+ fds_read.fd_count ? &fds_read : NULL,
+ fds_write.fd_count ? &fds_write : NULL,
+#endif
+ &fds_err, ptimeout);
+ if(r != -1)
+ break;
+ error = SOCKERRNO;
+ if(error && error_not_EINTR)
+ break;
+ if(timeout_ms > 0) {
+ pending_ms = timeout_ms - elapsed_ms;
+ if(pending_ms <= 0) {
+ r = 0; /* Simulate a "call timed out" case */
+ break;
+ }
+ }
+ } while(r == -1);
+
+ if(r < 0)
+ return -1;
+ if(r == 0)
+ return 0;
+
+ ret = 0;
+ if(readfd0 != CURL_SOCKET_BAD) {
+ if(FD_ISSET(readfd0, &fds_read))
+ ret |= CURL_CSELECT_IN;
+ if(FD_ISSET(readfd0, &fds_err))
+ ret |= CURL_CSELECT_ERR;
+ }
+ if(readfd1 != CURL_SOCKET_BAD) {
+ if(FD_ISSET(readfd1, &fds_read))
+ ret |= CURL_CSELECT_IN2;
+ if(FD_ISSET(readfd1, &fds_err))
+ ret |= CURL_CSELECT_ERR;
+ }
+ if(writefd != CURL_SOCKET_BAD) {
+ if(FD_ISSET(writefd, &fds_write))
+ ret |= CURL_CSELECT_OUT;
+ if(FD_ISSET(writefd, &fds_err))
+ ret |= CURL_CSELECT_ERR;
+ }
+
+ return ret;
+
+#endif /* HAVE_POLL_FINE */
+
+}
+
+/*
+ * 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 is too large for FD_SETSIZE.
+ * A negative timeout value makes this function wait indefinitely,
+ * unles no valid file descriptor is given, when this happens the
+ * negative timeout is ignored and the function times out immediately.
+ *
+ * Return values:
+ * -1 = system call error or fd >= FD_SETSIZE
+ * 0 = timeout
+ * N = number of structures with non zero revent fields
+ */
+CURL_STATIC int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms)
+{
+#ifndef HAVE_POLL_FINE
+ struct timeval pending_tv;
+ struct timeval *ptimeout;
+ fd_set fds_read;
+ fd_set fds_write;
+ fd_set fds_err;
+ curl_socket_t maxfd;
+#endif
+ struct timeval initial_tv = {0, 0};
+ bool fds_none = TRUE;
+ unsigned int i;
+ int pending_ms = 0;
+ int error;
+ int r;
+
+ if(ufds) {
+ for(i = 0; i < nfds; i++) {
+ if(ufds[i].fd != CURL_SOCKET_BAD) {
+ fds_none = FALSE;
+ break;
+ }
+ }
+ }
+ if(fds_none) {
+ r = Curl_wait_ms(timeout_ms);
+ return r;
+ }
+
+ /* Avoid initial timestamp, avoid curlx_tvnow() call, when elapsed
+ time in this function does not need to be measured. This happens
+ when function is called with a zero timeout or a negative timeout
+ value indicating a blocking call should be performed. */
+
+ if(timeout_ms > 0) {
+ pending_ms = timeout_ms;
+ initial_tv = curlx_tvnow();
+ }
+
+#ifdef HAVE_POLL_FINE
+
+ do {
+ if(timeout_ms < 0)
+ pending_ms = -1;
+ else if(!timeout_ms)
+ pending_ms = 0;
+ r = poll(ufds, nfds, pending_ms);
+ if(r != -1)
+ break;
+ error = SOCKERRNO;
+ if(error && error_not_EINTR)
+ break;
+ if(timeout_ms > 0) {
+ pending_ms = timeout_ms - elapsed_ms;
+ if(pending_ms <= 0) {
+ r = 0; /* Simulate a "call timed out" case */
+ break;
+ }
+ }
+ } while(r == -1);
+
+ if(r < 0)
+ return -1;
+ if(r == 0)
+ return 0;
+
+ for(i = 0; i < nfds; i++) {
+ if(ufds[i].fd == CURL_SOCKET_BAD)
+ continue;
+ if(ufds[i].revents & POLLHUP)
+ ufds[i].revents |= POLLIN;
+ if(ufds[i].revents & POLLERR)
+ ufds[i].revents |= (POLLIN|POLLOUT);
+ }
+
+#else /* HAVE_POLL_FINE */
+
+ FD_ZERO(&fds_read);
+ FD_ZERO(&fds_write);
+ FD_ZERO(&fds_err);
+ maxfd = (curl_socket_t)-1;
+
+ for(i = 0; i < nfds; i++) {
+ ufds[i].revents = 0;
+ if(ufds[i].fd == CURL_SOCKET_BAD)
+ continue;
+ VERIFY_SOCK(ufds[i].fd);
+ if(ufds[i].events & (POLLIN|POLLOUT|POLLPRI|
+ POLLRDNORM|POLLWRNORM|POLLRDBAND)) {
+ if(ufds[i].fd > maxfd)
+ maxfd = ufds[i].fd;
+ if(ufds[i].events & (POLLRDNORM|POLLIN))
+ FD_SET(ufds[i].fd, &fds_read);
+ if(ufds[i].events & (POLLWRNORM|POLLOUT))
+ FD_SET(ufds[i].fd, &fds_write);
+ if(ufds[i].events & (POLLRDBAND|POLLPRI))
+ FD_SET(ufds[i].fd, &fds_err);
+ }
+ }
+
+#ifdef USE_WINSOCK
+ /* WinSock select() can't handle zero events. See the comment about this in
+ Curl_check_socket(). */
+ if(fds_read.fd_count == 0 && fds_write.fd_count == 0
+ && fds_err.fd_count == 0) {
+ r = Curl_wait_ms(timeout_ms);
+ return r;
+ }
+#endif
+
+ ptimeout = (timeout_ms < 0) ? NULL : &pending_tv;
+
+ do {
+ if(timeout_ms > 0) {
+ pending_tv.tv_sec = pending_ms / 1000;
+ pending_tv.tv_usec = (pending_ms % 1000) * 1000;
+ }
+ else if(!timeout_ms) {
+ pending_tv.tv_sec = 0;
+ pending_tv.tv_usec = 0;
+ }
+ r = select((int)maxfd + 1,
+#ifndef USE_WINSOCK
+ &fds_read, &fds_write, &fds_err,
+#else
+ /* WinSock select() can't handle fd_sets with zero bits set, so
+ don't give it such arguments. See the comment about this in
+ Curl_check_socket().
+ */
+ fds_read.fd_count ? &fds_read : NULL,
+ fds_write.fd_count ? &fds_write : NULL,
+ fds_err.fd_count ? &fds_err : NULL,
+#endif
+ ptimeout);
+ if(r != -1)
+ break;
+ error = SOCKERRNO;
+ if(error && error_not_EINTR)
+ break;
+ if(timeout_ms > 0) {
+ pending_ms = timeout_ms - elapsed_ms;
+ if(pending_ms <= 0) {
+ r = 0; /* Simulate a "call timed out" case */
+ break;
+ }
+ }
+ } while(r == -1);
+
+ 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 == CURL_SOCKET_BAD)
+ 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 |= POLLPRI;
+ if(ufds[i].revents != 0)
+ r++;
+ }
+
+#endif /* HAVE_POLL_FINE */
+
+ return r;
+}
+
+#ifdef TPF
+/*
+ * This is a replacement for select() on the TPF platform.
+ * It is used whenever libcurl calls select().
+ * The call below to tpf_process_signals() is required because
+ * TPF's select calls are not signal interruptible.
+ *
+ * Return values are the same as select's.
+ */
+int tpf_select_libcurl(int maxfds, fd_set* reads, fd_set* writes,
+ fd_set* excepts, struct timeval* tv)
+{
+ int rc;
+
+ rc = tpf_select_bsd(maxfds, reads, writes, excepts, tv);
+ tpf_process_signals();
+ return rc;
+}
+#endif /* TPF */