mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-06-26 14:28:30 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Fix bug with send() on Windows in O_NONBLOCK mode

Browse source 
There is a bug in WIN32 where using CancelIoEx() on an overlapped i/o op
initiated by WSASend() will cause WSAGetOverlappedResult() to report the
operation failed when it actually succeeded. We now work around that, by
having send and sendto initially consult WSAPoll() on O_NONBLOCK sockets
This commit is contained in:
Justine Tunney 2024-09-16 20:49:58 -07:00
parent 5aa970bc4e
commit 3c58ecd00c
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
4 changed files with 22 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

21
libc/sock/winsockblock.c
View file

@ -30,17 +30,19 @@
#include "libc/nt/events.h"
#include "libc/nt/runtime.h"
#include "libc/nt/struct/overlapped.h"
#include "libc/nt/struct/pollfd.h"
#include "libc/nt/synchronization.h"
#include "libc/nt/thread.h"
#include "libc/nt/winsock.h"
#include "libc/sock/internal.h"
#include "libc/sysv/consts/poll.h"
#include "libc/sysv/consts/sicode.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/posixthread.internal.h"
#ifdef __x86_64__
textwindows ssize_t
__winsock_block(int64_t handle, uint32_t flags, bool nonblock,
__winsock_block(int64_t handle, uint32_t flags, int nonblock,
uint32_t srwtimeout, sigset_t waitmask,
int StartSocketOp(int64_t handle, struct NtOverlapped *overlap,
uint32_t *flags, void *arg),
@ -61,6 +63,21 @@ __winsock_block(int64_t handle, uint32_t flags, bool nonblock,
bool got_eagain = false;
uint32_t other_error = 0;
// send() and sendto() provide O_NONBLOCK as a negative number
// because winsock has a bug that causes CancelIoEx() to cause
// WSAGetOverlappedResult() to report errors when it succeeded
if (nonblock < 0) {
struct sys_pollfd_nt fds[1] = {{handle, POLLOUT}};
switch (WSAPoll(fds, 1, 0)) {
case -1:
return __winsockerr();
case 0:
return eagain();
default:
break;
}
}
// create event handle for overlapped i/o
intptr_t event;
if (!(event = WSACreateEvent()))
@ -69,7 +86,7 @@ __winsock_block(int64_t handle, uint32_t flags, bool nonblock,
struct NtOverlapped overlap = {.hEvent = event};
bool32 ok = !StartSocketOp(handle, &overlap, &flags, arg);
if (!ok && WSAGetLastError() == kNtErrorIoPending) {
if (nonblock) {
if (nonblock > 0) {
CancelIoEx(handle, &overlap);
got_eagain = true;
} else {