diff options
Diffstat (limited to 'Utilities/cmlibuv/src/unix/stream.c')
| -rw-r--r-- | Utilities/cmlibuv/src/unix/stream.c | 1629 |
1 files changed, 1629 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/unix/stream.c b/Utilities/cmlibuv/src/unix/stream.c new file mode 100644 index 0000000000..1ce75257b2 --- /dev/null +++ b/Utilities/cmlibuv/src/unix/stream.c @@ -0,0 +1,1629 @@ +/* Copyright Joyent, Inc. and other Node contributors. All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include "uv.h" +#include "internal.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <errno.h> + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/uio.h> +#include <sys/un.h> +#include <unistd.h> +#include <limits.h> /* IOV_MAX */ + +#if defined(__APPLE__) +# include <sys/event.h> +# include <sys/time.h> +# include <sys/select.h> + +/* Forward declaration */ +typedef struct uv__stream_select_s uv__stream_select_t; + +struct uv__stream_select_s { + uv_stream_t* stream; + uv_thread_t thread; + uv_sem_t close_sem; + uv_sem_t async_sem; + uv_async_t async; + int events; + int fake_fd; + int int_fd; + int fd; + fd_set* sread; + size_t sread_sz; + fd_set* swrite; + size_t swrite_sz; +}; +#endif /* defined(__APPLE__) */ + +static void uv__stream_connect(uv_stream_t*); +static void uv__write(uv_stream_t* stream); +static void uv__read(uv_stream_t* stream); +static void uv__stream_io(uv_loop_t* loop, uv__io_t* w, unsigned int events); +static void uv__write_callbacks(uv_stream_t* stream); +static size_t uv__write_req_size(uv_write_t* req); +static void uv__drain(uv_stream_t* stream); + + +void uv__stream_init(uv_loop_t* loop, + uv_stream_t* stream, + uv_handle_type type) { + int err; + + uv__handle_init(loop, (uv_handle_t*)stream, type); + stream->read_cb = NULL; + stream->alloc_cb = NULL; + stream->close_cb = NULL; + stream->connection_cb = NULL; + stream->connect_req = NULL; + stream->shutdown_req = NULL; + stream->accepted_fd = -1; + stream->queued_fds = NULL; + stream->delayed_error = 0; + QUEUE_INIT(&stream->write_queue); + QUEUE_INIT(&stream->write_completed_queue); + stream->write_queue_size = 0; + + if (loop->emfile_fd == -1) { + err = uv__open_cloexec("/dev/null", O_RDONLY); + if (err < 0) + /* In the rare case that "/dev/null" isn't mounted open "/" + * instead. + */ + err = uv__open_cloexec("/", O_RDONLY); + if (err >= 0) + loop->emfile_fd = err; + } + +#if defined(__APPLE__) && !defined(CMAKE_BOOTSTRAP) + stream->select = NULL; +#endif /* defined(__APPLE_) */ + + uv__io_init(&stream->io_watcher, uv__stream_io, -1); +} + + +static void uv__stream_osx_interrupt_select(uv_stream_t* stream) { +#if defined(__APPLE__) && !defined(CMAKE_BOOTSTRAP) + /* Notify select() thread about state change */ + uv__stream_select_t* s; + int r; + + s = stream->select; + if (s == NULL) + return; + + /* Interrupt select() loop + * NOTE: fake_fd and int_fd are socketpair(), thus writing to one will + * emit read event on other side + */ + do + r = write(s->fake_fd, "x", 1); + while (r == -1 && errno == EINTR); + + assert(r == 1); +#else /* !defined(__APPLE__) */ + /* No-op on any other platform */ +#endif /* !defined(__APPLE__) */ +} + + +#if defined(__APPLE__) && !defined(CMAKE_BOOTSTRAP) +static void uv__stream_osx_select(void* arg) { + uv_stream_t* stream; + uv__stream_select_t* s; + char buf[1024]; + int events; + int fd; + int r; + int max_fd; + + stream = arg; + s = stream->select; + fd = s->fd; + + if (fd > s->int_fd) + max_fd = fd; + else + max_fd = s->int_fd; + + for (;;) { + /* Terminate on semaphore */ + if (uv_sem_trywait(&s->close_sem) == 0) + break; + + /* Watch fd using select(2) */ + memset(s->sread, 0, s->sread_sz); + memset(s->swrite, 0, s->swrite_sz); + + if (uv__io_active(&stream->io_watcher, POLLIN)) + FD_SET(fd, s->sread); + if (uv__io_active(&stream->io_watcher, POLLOUT)) + FD_SET(fd, s->swrite); + FD_SET(s->int_fd, s->sread); + + /* Wait indefinitely for fd events */ + r = select(max_fd + 1, s->sread, s->swrite, NULL, NULL); + if (r == -1) { + if (errno == EINTR) + continue; + + /* XXX: Possible?! */ + abort(); + } + + /* Ignore timeouts */ + if (r == 0) + continue; + + /* Empty socketpair's buffer in case of interruption */ + if (FD_ISSET(s->int_fd, s->sread)) + for (;;) { + r = read(s->int_fd, buf, sizeof(buf)); + + if (r == sizeof(buf)) + continue; + + if (r != -1) + break; + + if (errno == EAGAIN || errno == EWOULDBLOCK) + break; + + if (errno == EINTR) + continue; + + abort(); + } + + /* Handle events */ + events = 0; + if (FD_ISSET(fd, s->sread)) + events |= POLLIN; + if (FD_ISSET(fd, s->swrite)) + events |= POLLOUT; + + assert(events != 0 || FD_ISSET(s->int_fd, s->sread)); + if (events != 0) { + ACCESS_ONCE(int, s->events) = events; + + uv_async_send(&s->async); + uv_sem_wait(&s->async_sem); + + /* Should be processed at this stage */ + assert((s->events == 0) || (stream->flags & UV_HANDLE_CLOSING)); + } + } +} + + +static void uv__stream_osx_select_cb(uv_async_t* handle) { + uv__stream_select_t* s; + uv_stream_t* stream; + int events; + + s = container_of(handle, uv__stream_select_t, async); + stream = s->stream; + + /* Get and reset stream's events */ + events = s->events; + ACCESS_ONCE(int, s->events) = 0; + + assert(events != 0); + assert(events == (events & (POLLIN | POLLOUT))); + + /* Invoke callback on event-loop */ + if ((events & POLLIN) && uv__io_active(&stream->io_watcher, POLLIN)) + uv__stream_io(stream->loop, &stream->io_watcher, POLLIN); + + if ((events & POLLOUT) && uv__io_active(&stream->io_watcher, POLLOUT)) + uv__stream_io(stream->loop, &stream->io_watcher, POLLOUT); + + if (stream->flags & UV_HANDLE_CLOSING) + return; + + /* NOTE: It is important to do it here, otherwise `select()` might be called + * before the actual `uv__read()`, leading to the blocking syscall + */ + uv_sem_post(&s->async_sem); +} + + +static void uv__stream_osx_cb_close(uv_handle_t* async) { + uv__stream_select_t* s; + + s = container_of(async, uv__stream_select_t, async); + uv__free(s); +} + + +int uv__stream_try_select(uv_stream_t* stream, int* fd) { + /* + * kqueue doesn't work with some files from /dev mount on osx. + * select(2) in separate thread for those fds + */ + + struct kevent filter[1]; + struct kevent events[1]; + struct timespec timeout; + uv__stream_select_t* s; + int fds[2]; + int err; + int ret; + int kq; + int old_fd; + int max_fd; + size_t sread_sz; + size_t swrite_sz; + + kq = kqueue(); + if (kq == -1) { + perror("(libuv) kqueue()"); + return UV__ERR(errno); + } + + EV_SET(&filter[0], *fd, EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, 0); + + /* Use small timeout, because we only want to capture EINVALs */ + timeout.tv_sec = 0; + timeout.tv_nsec = 1; + + do + ret = kevent(kq, filter, 1, events, 1, &timeout); + while (ret == -1 && errno == EINTR); + + uv__close(kq); + + if (ret == -1) + return UV__ERR(errno); + + if (ret == 0 || (events[0].flags & EV_ERROR) == 0 || events[0].data != EINVAL) + return 0; + + /* At this point we definitely know that this fd won't work with kqueue */ + + /* + * Create fds for io watcher and to interrupt the select() loop. + * NOTE: do it ahead of malloc below to allocate enough space for fd_sets + */ + if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds)) + return UV__ERR(errno); + + max_fd = *fd; + if (fds[1] > max_fd) + max_fd = fds[1]; + + sread_sz = ROUND_UP(max_fd + 1, sizeof(uint32_t) * NBBY) / NBBY; + swrite_sz = sread_sz; + + s = uv__malloc(sizeof(*s) + sread_sz + swrite_sz); + if (s == NULL) { + err = UV_ENOMEM; + goto failed_malloc; + } + + s->events = 0; + s->fd = *fd; + s->sread = (fd_set*) ((char*) s + sizeof(*s)); + s->sread_sz = sread_sz; + s->swrite = (fd_set*) ((char*) s->sread + sread_sz); + s->swrite_sz = swrite_sz; + + err = uv_async_init(stream->loop, &s->async, uv__stream_osx_select_cb); + if (err) + goto failed_async_init; + + s->async.flags |= UV_HANDLE_INTERNAL; + uv__handle_unref(&s->async); + + err = uv_sem_init(&s->close_sem, 0); + if (err != 0) + goto failed_close_sem_init; + + err = uv_sem_init(&s->async_sem, 0); + if (err != 0) + goto failed_async_sem_init; + + s->fake_fd = fds[0]; + s->int_fd = fds[1]; + + old_fd = *fd; + s->stream = stream; + stream->select = s; + *fd = s->fake_fd; + + err = uv_thread_create(&s->thread, uv__stream_osx_select, stream); + if (err != 0) + goto failed_thread_create; + + return 0; + +failed_thread_create: + s->stream = NULL; + stream->select = NULL; + *fd = old_fd; + + uv_sem_destroy(&s->async_sem); + +failed_async_sem_init: + uv_sem_destroy(&s->close_sem); + +failed_close_sem_init: + uv__close(fds[0]); + uv__close(fds[1]); + uv_close((uv_handle_t*) &s->async, uv__stream_osx_cb_close); + return err; + +failed_async_init: + uv__free(s); + +failed_malloc: + uv__close(fds[0]); + uv__close(fds[1]); + + return err; +} +#endif /* defined(__APPLE__) */ + + +int uv__stream_open(uv_stream_t* stream, int fd, int flags) { +#if defined(__APPLE__) + int enable; +#endif + + if (!(stream->io_watcher.fd == -1 || stream->io_watcher.fd == fd)) + return UV_EBUSY; + + assert(fd >= 0); + stream->flags |= flags; + + if (stream->type == UV_TCP) { + if ((stream->flags & UV_HANDLE_TCP_NODELAY) && uv__tcp_nodelay(fd, 1)) + return UV__ERR(errno); + + /* TODO Use delay the user passed in. */ + if ((stream->flags & UV_HANDLE_TCP_KEEPALIVE) && + uv__tcp_keepalive(fd, 1, 60)) { + return UV__ERR(errno); + } + } + +#if defined(__APPLE__) + enable = 1; + if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &enable, sizeof(enable)) && + errno != ENOTSOCK && + errno != EINVAL) { + return UV__ERR(errno); + } +#endif + + stream->io_watcher.fd = fd; + + return 0; +} + + +void uv__stream_flush_write_queue(uv_stream_t* stream, int error) { + uv_write_t* req; + QUEUE* q; + while (!QUEUE_EMPTY(&stream->write_queue)) { + q = QUEUE_HEAD(&stream->write_queue); + QUEUE_REMOVE(q); + + req = QUEUE_DATA(q, uv_write_t, queue); + req->error = error; + + QUEUE_INSERT_TAIL(&stream->write_completed_queue, &req->queue); + } +} + + +void uv__stream_destroy(uv_stream_t* stream) { + assert(!uv__io_active(&stream->io_watcher, POLLIN | POLLOUT)); + assert(stream->flags & UV_HANDLE_CLOSED); + + if (stream->connect_req) { + uv__req_unregister(stream->loop, stream->connect_req); + stream->connect_req->cb(stream->connect_req, UV_ECANCELED); + stream->connect_req = NULL; + } + + uv__stream_flush_write_queue(stream, UV_ECANCELED); + uv__write_callbacks(stream); + uv__drain(stream); + + assert(stream->write_queue_size == 0); +} + + +/* Implements a best effort approach to mitigating accept() EMFILE errors. + * We have a spare file descriptor stashed away that we close to get below + * the EMFILE limit. Next, we accept all pending connections and close them + * immediately to signal the clients that we're overloaded - and we are, but + * we still keep on trucking. + * + * There is one caveat: it's not reliable in a multi-threaded environment. + * The file descriptor limit is per process. Our party trick fails if another + * thread opens a file or creates a socket in the time window between us + * calling close() and accept(). + */ +static int uv__emfile_trick(uv_loop_t* loop, int accept_fd) { + int err; + int emfile_fd; + + if (loop->emfile_fd == -1) + return UV_EMFILE; + + uv__close(loop->emfile_fd); + loop->emfile_fd = -1; + + do { + err = uv__accept(accept_fd); + if (err >= 0) + uv__close(err); + } while (err >= 0 || err == UV_EINTR); + + emfile_fd = uv__open_cloexec("/", O_RDONLY); + if (emfile_fd >= 0) + loop->emfile_fd = emfile_fd; + + return err; +} + + +#if defined(UV_HAVE_KQUEUE) +# define UV_DEC_BACKLOG(w) w->rcount--; +#else +# define UV_DEC_BACKLOG(w) /* no-op */ +#endif /* defined(UV_HAVE_KQUEUE) */ + + +void uv__server_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) { + uv_stream_t* stream; + int err; + + stream = container_of(w, uv_stream_t, io_watcher); + assert(events & POLLIN); + assert(stream->accepted_fd == -1); + assert(!(stream->flags & UV_HANDLE_CLOSING)); + + uv__io_start(stream->loop, &stream->io_watcher, POLLIN); + + /* connection_cb can close the server socket while we're + * in the loop so check it on each iteration. + */ + while (uv__stream_fd(stream) != -1) { + assert(stream->accepted_fd == -1); + +#if defined(UV_HAVE_KQUEUE) + if (w->rcount <= 0) + return; +#endif /* defined(UV_HAVE_KQUEUE) */ + + err = uv__accept(uv__stream_fd(stream)); + if (err < 0) { + if (err == UV_EAGAIN || err == UV__ERR(EWOULDBLOCK)) + return; /* Not an error. */ + + if (err == UV_ECONNABORTED) + continue; /* Ignore. Nothing we can do about that. */ + + if (err == UV_EMFILE || err == UV_ENFILE) { + err = uv__emfile_trick(loop, uv__stream_fd(stream)); + if (err == UV_EAGAIN || err == UV__ERR(EWOULDBLOCK)) + break; + } + + stream->connection_cb(stream, err); + continue; + } + + UV_DEC_BACKLOG(w) + stream->accepted_fd = err; + stream->connection_cb(stream, 0); + + if (stream->accepted_fd != -1) { + /* The user hasn't yet accepted called uv_accept() */ + uv__io_stop(loop, &stream->io_watcher, POLLIN); + return; + } + + if (stream->type == UV_TCP && + (stream->flags & UV_HANDLE_TCP_SINGLE_ACCEPT)) { + /* Give other processes a chance to accept connections. */ + struct timespec timeout = { 0, 1 }; + nanosleep(&timeout, NULL); + } + } +} + + +#undef UV_DEC_BACKLOG + + +int uv_accept(uv_stream_t* server, uv_stream_t* client) { + int err; + + assert(server->loop == client->loop); + + if (server->accepted_fd == -1) + return UV_EAGAIN; + + switch (client->type) { + case UV_NAMED_PIPE: + case UV_TCP: + err = uv__stream_open(client, + server->accepted_fd, + UV_HANDLE_READABLE | UV_HANDLE_WRITABLE); + if (err) { + /* TODO handle error */ + uv__close(server->accepted_fd); + goto done; + } + break; + + case UV_UDP: + err = uv_udp_open((uv_udp_t*) client, server->accepted_fd); + if (err) { + uv__close(server->accepted_fd); + goto done; + } + break; + + default: + return UV_EINVAL; + } + + client->flags |= UV_HANDLE_BOUND; + +done: + /* Process queued fds */ + if (server->queued_fds != NULL) { + uv__stream_queued_fds_t* queued_fds; + + queued_fds = server->queued_fds; + + /* Read first */ + server->accepted_fd = queued_fds->fds[0]; + + /* All read, free */ + assert(queued_fds->offset > 0); + if (--queued_fds->offset == 0) { + uv__free(queued_fds); + server->queued_fds = NULL; + } else { + /* Shift rest */ + memmove(queued_fds->fds, + queued_fds->fds + 1, + queued_fds->offset * sizeof(*queued_fds->fds)); + } + } else { + server->accepted_fd = -1; + if (err == 0) + uv__io_start(server->loop, &server->io_watcher, POLLIN); + } + return err; +} + + +int uv_listen(uv_stream_t* stream, int backlog, uv_connection_cb cb) { + int err; + if (uv__is_closing(stream)) { + return UV_EINVAL; + } + switch (stream->type) { + case UV_TCP: + err = uv__tcp_listen((uv_tcp_t*)stream, backlog, cb); + break; + + case UV_NAMED_PIPE: + err = uv__pipe_listen((uv_pipe_t*)stream, backlog, cb); + break; + + default: + err = UV_EINVAL; + } + + if (err == 0) + uv__handle_start(stream); + + return err; +} + + +static void uv__drain(uv_stream_t* stream) { + uv_shutdown_t* req; + int err; + + assert(QUEUE_EMPTY(&stream->write_queue)); + if (!(stream->flags & UV_HANDLE_CLOSING)) { + uv__io_stop(stream->loop, &stream->io_watcher, POLLOUT); + uv__stream_osx_interrupt_select(stream); + } + + if (!(stream->flags & UV_HANDLE_SHUTTING)) + return; + + req = stream->shutdown_req; + assert(req); + + if ((stream->flags & UV_HANDLE_CLOSING) || + !(stream->flags & UV_HANDLE_SHUT)) { + stream->shutdown_req = NULL; + stream->flags &= ~UV_HANDLE_SHUTTING; + uv__req_unregister(stream->loop, req); + + err = 0; + if (stream->flags & UV_HANDLE_CLOSING) + /* The user destroyed the stream before we got to do the shutdown. */ + err = UV_ECANCELED; + else if (shutdown(uv__stream_fd(stream), SHUT_WR)) + err = UV__ERR(errno); + else /* Success. */ + stream->flags |= UV_HANDLE_SHUT; + + if (req->cb != NULL) + req->cb(req, err); + } +} + + +static ssize_t uv__writev(int fd, struct iovec* vec, size_t n) { + if (n == 1) + return write(fd, vec->iov_base, vec->iov_len); + else + return writev(fd, vec, n); +} + + +static size_t uv__write_req_size(uv_write_t* req) { + size_t size; + + assert(req->bufs != NULL); + size = uv__count_bufs(req->bufs + req->write_index, + req->nbufs - req->write_index); + assert(req->handle->write_queue_size >= size); + + return size; +} + + +/* Returns 1 if all write request data has been written, or 0 if there is still + * more data to write. + * + * Note: the return value only says something about the *current* request. + * There may still be other write requests sitting in the queue. + */ +static int uv__write_req_update(uv_stream_t* stream, + uv_write_t* req, + size_t n) { + uv_buf_t* buf; + size_t len; + + assert(n <= stream->write_queue_size); + stream->write_queue_size -= n; + + buf = req->bufs + req->write_index; + + do { + len = n < buf->len ? n : buf->len; + buf->base += len; + buf->len -= len; + buf += (buf->len == 0); /* Advance to next buffer if this one is empty. */ + n -= len; + } while (n > 0); + + req->write_index = buf - req->bufs; + + return req->write_index == req->nbufs; +} + + +static void uv__write_req_finish(uv_write_t* req) { + uv_stream_t* stream = req->handle; + + /* Pop the req off tcp->write_queue. */ + QUEUE_REMOVE(&req->queue); + + /* Only free when there was no error. On error, we touch up write_queue_size + * right before making the callback. The reason we don't do that right away + * is that a write_queue_size > 0 is our only way to signal to the user that + * they should stop writing - which they should if we got an error. Something + * to revisit in future revisions of the libuv API. + */ + if (req->error == 0) { + if (req->bufs != req->bufsml) + uv__free(req->bufs); + req->bufs = NULL; + } + + /* Add it to the write_completed_queue where it will have its + * callback called in the near future. + */ + QUEUE_INSERT_TAIL(&stream->write_completed_queue, &req->queue); + uv__io_feed(stream->loop, &stream->io_watcher); +} + + +static int uv__handle_fd(uv_handle_t* handle) { + switch (handle->type) { + case UV_NAMED_PIPE: + case UV_TCP: + return ((uv_stream_t*) handle)->io_watcher.fd; + + case UV_UDP: + return ((uv_udp_t*) handle)->io_watcher.fd; + + default: + return -1; + } +} + +static int uv__try_write(uv_stream_t* stream, + const uv_buf_t bufs[], + unsigned int nbufs, + uv_stream_t* send_handle) { + struct iovec* iov; + int iovmax; + int iovcnt; + ssize_t n; + + /* + * Cast to iovec. We had to have our own uv_buf_t instead of iovec + * because Windows's WSABUF is not an iovec. + */ + iov = (struct iovec*) bufs; + iovcnt = nbufs; + + iovmax = uv__getiovmax(); + + /* Limit iov count to avoid EINVALs from writev() */ + if (iovcnt > iovmax) + iovcnt = iovmax; + + /* + * Now do the actual writev. Note that we've been updating the pointers + * inside the iov each time we write. So there is no need to offset it. + */ + if (send_handle != NULL) { + int fd_to_send; + struct msghdr msg; + struct cmsghdr *cmsg; + union { + char data[64]; + struct cmsghdr alias; + } scratch; + + if (uv__is_closing(send_handle)) + return UV_EBADF; + + fd_to_send = uv__handle_fd((uv_handle_t*) send_handle); + + memset(&scratch, 0, sizeof(scratch)); + + assert(fd_to_send >= 0); + + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_iov = iov; + msg.msg_iovlen = iovcnt; + msg.msg_flags = 0; + + msg.msg_control = &scratch.alias; + msg.msg_controllen = CMSG_SPACE(sizeof(fd_to_send)); + + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(fd_to_send)); + + /* silence aliasing warning */ + { + void* pv = CMSG_DATA(cmsg); + int* pi = pv; + *pi = fd_to_send; + } + + do + n = sendmsg(uv__stream_fd(stream), &msg, 0); + while (n == -1 && errno == EINTR); + } else { + do + n = uv__writev(uv__stream_fd(stream), iov, iovcnt); + while (n == -1 && errno == EINTR); + } + + if (n >= 0) + return n; + + if (errno == EAGAIN || errno == EWOULDBLOCK || errno == ENOBUFS) + return UV_EAGAIN; + +#ifdef __APPLE__ + /* macOS versions 10.10 and 10.15 - and presumbaly 10.11 to 10.14, too - + * have a bug where a race condition causes the kernel to return EPROTOTYPE + * because the socket isn't fully constructed. It's probably the result of + * the peer closing the connection and that is why libuv translates it to + * ECONNRESET. Previously, libuv retried until the EPROTOTYPE error went + * away but some VPN software causes the same behavior except the error is + * permanent, not transient, turning the retry mechanism into an infinite + * loop. See https://github.com/libuv/libuv/pull/482. + */ + if (errno == EPROTOTYPE) + return UV_ECONNRESET; +#endif /* __APPLE__ */ + + return UV__ERR(errno); +} + +static void uv__write(uv_stream_t* stream) { + QUEUE* q; + uv_write_t* req; + ssize_t n; + + assert(uv__stream_fd(stream) >= 0); + + for (;;) { + if (QUEUE_EMPTY(&stream->write_queue)) + return; + + q = QUEUE_HEAD(&stream->write_queue); + req = QUEUE_DATA(q, uv_write_t, queue); + assert(req->handle == stream); + + n = uv__try_write(stream, + &(req->bufs[req->write_index]), + req->nbufs - req->write_index, + req->send_handle); + + /* Ensure the handle isn't sent again in case this is a partial write. */ + if (n >= 0) { + req->send_handle = NULL; + if (uv__write_req_update(stream, req, n)) { + uv__write_req_finish(req); + return; /* TODO(bnoordhuis) Start trying to write the next request. */ + } + } else if (n != UV_EAGAIN) + break; + + /* If this is a blocking stream, try again. */ + if (stream->flags & UV_HANDLE_BLOCKING_WRITES) + continue; + + /* We're not done. */ + uv__io_start(stream->loop, &stream->io_watcher, POLLOUT); + + /* Notify select() thread about state change */ + uv__stream_osx_interrupt_select(stream); + + return; + } + + req->error = n; + uv__write_req_finish(req); + uv__io_stop(stream->loop, &stream->io_watcher, POLLOUT); + uv__stream_osx_interrupt_select(stream); +} + + +static void uv__write_callbacks(uv_stream_t* stream) { + uv_write_t* req; + QUEUE* q; + QUEUE pq; + + if (QUEUE_EMPTY(&stream->write_completed_queue)) + return; + + QUEUE_MOVE(&stream->write_completed_queue, &pq); + + while (!QUEUE_EMPTY(&pq)) { + /* Pop a req off write_completed_queue. */ + q = QUEUE_HEAD(&pq); + req = QUEUE_DATA(q, uv_write_t, queue); + QUEUE_REMOVE(q); + uv__req_unregister(stream->loop, req); + + if (req->bufs != NULL) { + stream->write_queue_size -= uv__write_req_size(req); + if (req->bufs != req->bufsml) + uv__free(req->bufs); + req->bufs = NULL; + } + + /* NOTE: call callback AFTER freeing the request data. */ + if (req->cb) + req->cb(req, req->error); + } +} + + +static void uv__stream_eof(uv_stream_t* stream, const uv_buf_t* buf) { + stream->flags |= UV_HANDLE_READ_EOF; + stream->flags &= ~UV_HANDLE_READING; + uv__io_stop(stream->loop, &stream->io_watcher, POLLIN); + uv__handle_stop(stream); + uv__stream_osx_interrupt_select(stream); + stream->read_cb(stream, UV_EOF, buf); +} + + +static int uv__stream_queue_fd(uv_stream_t* stream, int fd) { + uv__stream_queued_fds_t* queued_fds; + unsigned int queue_size; + + queued_fds = stream->queued_fds; + if (queued_fds == NULL) { + queue_size = 8; + queued_fds = uv__malloc((queue_size - 1) * sizeof(*queued_fds->fds) + + sizeof(*queued_fds)); + if (queued_fds == NULL) + return UV_ENOMEM; + queued_fds->size = queue_size; + queued_fds->offset = 0; + stream->queued_fds = queued_fds; + + /* Grow */ + } else if (queued_fds->size == queued_fds->offset) { + queue_size = queued_fds->size + 8; + queued_fds = uv__realloc(queued_fds, + (queue_size - 1) * sizeof(*queued_fds->fds) + + sizeof(*queued_fds)); + + /* + * Allocation failure, report back. + * NOTE: if it is fatal - sockets will be closed in uv__stream_close + */ + if (queued_fds == NULL) + return UV_ENOMEM; + queued_fds->size = queue_size; + stream->queued_fds = queued_fds; + } + + /* Put fd in a queue */ + queued_fds->fds[queued_fds->offset++] = fd; + + return 0; +} + + +#if defined(__PASE__) +/* on IBMi PASE the control message length can not exceed 256. */ +# define UV__CMSG_FD_COUNT 60 +#else +# define UV__CMSG_FD_COUNT 64 +#endif +#define UV__CMSG_FD_SIZE (UV__CMSG_FD_COUNT * sizeof(int)) + + +static int uv__stream_recv_cmsg(uv_stream_t* stream, struct msghdr* msg) { + struct cmsghdr* cmsg; + + for (cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) { + char* start; + char* end; + int err; + void* pv; + int* pi; + unsigned int i; + unsigned int count; + + if (cmsg->cmsg_type != SCM_RIGHTS) { + fprintf(stderr, "ignoring non-SCM_RIGHTS ancillary data: %d\n", + cmsg->cmsg_type); + continue; + } + + /* silence aliasing warning */ + pv = CMSG_DATA(cmsg); + pi = pv; + + /* Count available fds */ + start = (char*) cmsg; + end = (char*) cmsg + cmsg->cmsg_len; + count = 0; + while (start + CMSG_LEN(count * sizeof(*pi)) < end) + count++; + assert(start + CMSG_LEN(count * sizeof(*pi)) == end); + + for (i = 0; i < count; i++) { + /* Already has accepted fd, queue now */ + if (stream->accepted_fd != -1) { + err = uv__stream_queue_fd(stream, pi[i]); + if (err != 0) { + /* Close rest */ + for (; i < count; i++) + uv__close(pi[i]); + return err; + } + } else { + stream->accepted_fd = pi[i]; + } + } + } + + return 0; +} + + +#ifdef __clang__ +# pragma clang diagnostic push +# pragma clang diagnostic ignored "-Wgnu-folding-constant" +# pragma clang diagnostic ignored "-Wvla-extension" +#endif + +static void uv__read(uv_stream_t* stream) { + uv_buf_t buf; + ssize_t nread; + struct msghdr msg; + char cmsg_space[CMSG_SPACE(UV__CMSG_FD_SIZE)]; + int count; + int err; + int is_ipc; + + stream->flags &= ~UV_HANDLE_READ_PARTIAL; + + /* Prevent loop starvation when the data comes in as fast as (or faster than) + * we can read it. XXX Need to rearm fd if we switch to edge-triggered I/O. + */ + count = 32; + + is_ipc = stream->type == UV_NAMED_PIPE && ((uv_pipe_t*) stream)->ipc; + + /* XXX: Maybe instead of having UV_HANDLE_READING we just test if + * tcp->read_cb is NULL or not? + */ + while (stream->read_cb + && (stream->flags & UV_HANDLE_READING) + && (count-- > 0)) { + assert(stream->alloc_cb != NULL); + + buf = uv_buf_init(NULL, 0); + stream->alloc_cb((uv_handle_t*)stream, 64 * 1024, &buf); + if (buf.base == NULL || buf.len == 0) { + /* User indicates it can't or won't handle the read. */ + stream->read_cb(stream, UV_ENOBUFS, &buf); + return; + } + + assert(buf.base != NULL); + assert(uv__stream_fd(stream) >= 0); + + if (!is_ipc) { + do { + nread = read(uv__stream_fd(stream), buf.base, buf.len); + } + while (nread < 0 && errno == EINTR); + } else { + /* ipc uses recvmsg */ + msg.msg_flags = 0; + msg.msg_iov = (struct iovec*) &buf; + msg.msg_iovlen = 1; + msg.msg_name = NULL; + msg.msg_namelen = 0; + /* Set up to receive a descriptor even if one isn't in the message */ + msg.msg_controllen = sizeof(cmsg_space); + msg.msg_control = cmsg_space; + + do { + nread = uv__recvmsg(uv__stream_fd(stream), &msg, 0); + } + while (nread < 0 && errno == EINTR); + } + + if (nread < 0) { + /* Error */ + if (errno == EAGAIN || errno == EWOULDBLOCK) { + /* Wait for the next one. */ + if (stream->flags & UV_HANDLE_READING) { + uv__io_start(stream->loop, &stream->io_watcher, POLLIN); + uv__stream_osx_interrupt_select(stream); + } + stream->read_cb(stream, 0, &buf); +#if defined(__CYGWIN__) || defined(__MSYS__) + } else if (errno == ECONNRESET && stream->type == UV_NAMED_PIPE) { + uv__stream_eof(stream, &buf); + return; +#endif + } else { + /* Error. User should call uv_close(). */ + stream->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE); + stream->read_cb(stream, UV__ERR(errno), &buf); + if (stream->flags & UV_HANDLE_READING) { + stream->flags &= ~UV_HANDLE_READING; + uv__io_stop(stream->loop, &stream->io_watcher, POLLIN); + uv__handle_stop(stream); + uv__stream_osx_interrupt_select(stream); + } + } + return; + } else if (nread == 0) { + uv__stream_eof(stream, &buf); + return; + } else { + /* Successful read */ + ssize_t buflen = buf.len; + + if (is_ipc) { + err = uv__stream_recv_cmsg(stream, &msg); + if (err != 0) { + stream->read_cb(stream, err, &buf); + return; + } + } + +#if defined(__MVS__) + if (is_ipc && msg.msg_controllen > 0) { + uv_buf_t blankbuf; + int nread; + struct iovec *old; + + blankbuf.base = 0; + blankbuf.len = 0; + old = msg.msg_iov; + msg.msg_iov = (struct iovec*) &blankbuf; + nread = 0; + do { + nread = uv__recvmsg(uv__stream_fd(stream), &msg, 0); + err = uv__stream_recv_cmsg(stream, &msg); + if (err != 0) { + stream->read_cb(stream, err, &buf); + msg.msg_iov = old; + return; + } + } while (nread == 0 && msg.msg_controllen > 0); + msg.msg_iov = old; + } +#endif + stream->read_cb(stream, nread, &buf); + + /* Return if we didn't fill the buffer, there is no more data to read. */ + if (nread < buflen) { + stream->flags |= UV_HANDLE_READ_PARTIAL; + return; + } + } + } +} + + +#ifdef __clang__ +# pragma clang diagnostic pop +#endif + +#undef UV__CMSG_FD_COUNT +#undef UV__CMSG_FD_SIZE + + +int uv_shutdown(uv_shutdown_t* req, uv_stream_t* stream, uv_shutdown_cb cb) { + assert(stream->type == UV_TCP || + stream->type == UV_TTY || + stream->type == UV_NAMED_PIPE); + + if (!(stream->flags & UV_HANDLE_WRITABLE) || + stream->flags & UV_HANDLE_SHUT || + stream->flags & UV_HANDLE_SHUTTING || + uv__is_closing(stream)) { + return UV_ENOTCONN; + } + + assert(uv__stream_fd(stream) >= 0); + + /* Initialize request. The `shutdown(2)` call will always be deferred until + * `uv__drain`, just before the callback is run. */ + uv__req_init(stream->loop, req, UV_SHUTDOWN); + req->handle = stream; + req->cb = cb; + stream->shutdown_req = req; + stream->flags |= UV_HANDLE_SHUTTING; + stream->flags &= ~UV_HANDLE_WRITABLE; + + if (QUEUE_EMPTY(&stream->write_queue)) + uv__io_feed(stream->loop, &stream->io_watcher); + + return 0; +} + + +static void uv__stream_io(uv_loop_t* loop, uv__io_t* w, unsigned int events) { + uv_stream_t* stream; + + stream = container_of(w, uv_stream_t, io_watcher); + + assert(stream->type == UV_TCP || + stream->type == UV_NAMED_PIPE || + stream->type == UV_TTY); + assert(!(stream->flags & UV_HANDLE_CLOSING)); + + if (stream->connect_req) { + uv__stream_connect(stream); + return; + } + + assert(uv__stream_fd(stream) >= 0); + + /* Ignore POLLHUP here. Even if it's set, there may still be data to read. */ + if (events & (POLLIN | POLLERR | POLLHUP)) + uv__read(stream); + + if (uv__stream_fd(stream) == -1) + return; /* read_cb closed stream. */ + + /* Short-circuit iff POLLHUP is set, the user is still interested in read + * events and uv__read() reported a partial read but not EOF. If the EOF + * flag is set, uv__read() called read_cb with err=UV_EOF and we don't + * have to do anything. If the partial read flag is not set, we can't + * report the EOF yet because there is still data to read. + */ + if ((events & POLLHUP) && + (stream->flags & UV_HANDLE_READING) && + (stream->flags & UV_HANDLE_READ_PARTIAL) && + !(stream->flags & UV_HANDLE_READ_EOF)) { + uv_buf_t buf = { NULL, 0 }; + uv__stream_eof(stream, &buf); + } + + if (uv__stream_fd(stream) == -1) + return; /* read_cb closed stream. */ + + if (events & (POLLOUT | POLLERR | POLLHUP)) { + uv__write(stream); + uv__write_callbacks(stream); + + /* Write queue drained. */ + if (QUEUE_EMPTY(&stream->write_queue)) + uv__drain(stream); + } +} + + +/** + * We get called here from directly following a call to connect(2). + * In order to determine if we've errored out or succeeded must call + * getsockopt. + */ +static void uv__stream_connect(uv_stream_t* stream) { + int error; + uv_connect_t* req = stream->connect_req; + socklen_t errorsize = sizeof(int); + + assert(stream->type == UV_TCP || stream->type == UV_NAMED_PIPE); + assert(req); + + if (stream->delayed_error) { + /* To smooth over the differences between unixes errors that + * were reported synchronously on the first connect can be delayed + * until the next tick--which is now. + */ + error = stream->delayed_error; + stream->delayed_error = 0; + } else { + /* Normal situation: we need to get the socket error from the kernel. */ + assert(uv__stream_fd(stream) >= 0); + getsockopt(uv__stream_fd(stream), + SOL_SOCKET, + SO_ERROR, + &error, + &errorsize); + error = UV__ERR(error); + } + + if (error == UV__ERR(EINPROGRESS)) + return; + + stream->connect_req = NULL; + uv__req_unregister(stream->loop, req); + + if (error < 0 || QUEUE_EMPTY(&stream->write_queue)) { + uv__io_stop(stream->loop, &stream->io_watcher, POLLOUT); + } + + if (req->cb) + req->cb(req, error); + + if (uv__stream_fd(stream) == -1) + return; + + if (error < 0) { + uv__stream_flush_write_queue(stream, UV_ECANCELED); + uv__write_callbacks(stream); + } +} + + +static int uv__check_before_write(uv_stream_t* stream, + unsigned int nbufs, + uv_stream_t* send_handle) { + assert(nbufs > 0); + assert((stream->type == UV_TCP || + stream->type == UV_NAMED_PIPE || + stream->type == UV_TTY) && + "uv_write (unix) does not yet support other types of streams"); + + if (uv__stream_fd(stream) < 0) + return UV_EBADF; + + if (!(stream->flags & UV_HANDLE_WRITABLE)) + return UV_EPIPE; + + if (send_handle != NULL) { + if (stream->type != UV_NAMED_PIPE || !((uv_pipe_t*)stream)->ipc) + return UV_EINVAL; + + /* XXX We abuse uv_write2() to send over UDP handles to child processes. + * Don't call uv__stream_fd() on those handles, it's a macro that on OS X + * evaluates to a function that operates on a uv_stream_t with a couple of + * OS X specific fields. On other Unices it does (handle)->io_watcher.fd, + * which works but only by accident. + */ + if (uv__handle_fd((uv_handle_t*) send_handle) < 0) + return UV_EBADF; + +#if defined(__CYGWIN__) || defined(__MSYS__) + /* Cygwin recvmsg always sets msg_controllen to zero, so we cannot send it. + See https://github.com/mirror/newlib-cygwin/blob/86fc4bf0/winsup/cygwin/fhandler_socket.cc#L1736-L1743 */ + return UV_ENOSYS; +#endif + } + + return 0; +} + +int uv_write2(uv_write_t* req, + uv_stream_t* stream, + const uv_buf_t bufs[], + unsigned int nbufs, + uv_stream_t* send_handle, + uv_write_cb cb) { + int empty_queue; + int err; + + err = uv__check_before_write(stream, nbufs, send_handle); + if (err < 0) + return err; + + /* It's legal for write_queue_size > 0 even when the write_queue is empty; + * it means there are error-state requests in the write_completed_queue that + * will touch up write_queue_size later, see also uv__write_req_finish(). + * We could check that write_queue is empty instead but that implies making + * a write() syscall when we know that the handle is in error mode. + */ + empty_queue = (stream->write_queue_size == 0); + + /* Initialize the req */ + uv__req_init(stream->loop, req, UV_WRITE); + req->cb = cb; + req->handle = stream; + req->error = 0; + req->send_handle = send_handle; + QUEUE_INIT(&req->queue); + + req->bufs = req->bufsml; + if (nbufs > ARRAY_SIZE(req->bufsml)) + req->bufs = uv__malloc(nbufs * sizeof(bufs[0])); + + if (req->bufs == NULL) + return UV_ENOMEM; + + memcpy(req->bufs, bufs, nbufs * sizeof(bufs[0])); + req->nbufs = nbufs; + req->write_index = 0; + stream->write_queue_size += uv__count_bufs(bufs, nbufs); + + /* Append the request to write_queue. */ + QUEUE_INSERT_TAIL(&stream->write_queue, &req->queue); + + /* If the queue was empty when this function began, we should attempt to + * do the write immediately. Otherwise start the write_watcher and wait + * for the fd to become writable. + */ + if (stream->connect_req) { + /* Still connecting, do nothing. */ + } + else if (empty_queue) { + uv__write(stream); + } + else { + /* + * blocking streams should never have anything in the queue. + * if this assert fires then somehow the blocking stream isn't being + * sufficiently flushed in uv__write. + */ + assert(!(stream->flags & UV_HANDLE_BLOCKING_WRITES)); + uv__io_start(stream->loop, &stream->io_watcher, POLLOUT); + uv__stream_osx_interrupt_select(stream); + } + + return 0; +} + + +/* The buffers to be written must remain valid until the callback is called. + * This is not required for the uv_buf_t array. + */ +int uv_write(uv_write_t* req, + uv_stream_t* handle, + const uv_buf_t bufs[], + unsigned int nbufs, + uv_write_cb cb) { + return uv_write2(req, handle, bufs, nbufs, NULL, cb); +} + + +int uv_try_write(uv_stream_t* stream, + const uv_buf_t bufs[], + unsigned int nbufs) { + return uv_try_write2(stream, bufs, nbufs, NULL); +} + + +int uv_try_write2(uv_stream_t* stream, + const uv_buf_t bufs[], + unsigned int nbufs, + uv_stream_t* send_handle) { + int err; + + /* Connecting or already writing some data */ + if (stream->connect_req != NULL || stream->write_queue_size != 0) + return UV_EAGAIN; + + err = uv__check_before_write(stream, nbufs, NULL); + if (err < 0) + return err; + + return uv__try_write(stream, bufs, nbufs, send_handle); +} + + +int uv__read_start(uv_stream_t* stream, + uv_alloc_cb alloc_cb, + uv_read_cb read_cb) { + assert(stream->type == UV_TCP || stream->type == UV_NAMED_PIPE || + stream->type == UV_TTY); + + /* The UV_HANDLE_READING flag is irrelevant of the state of the stream - it + * just expresses the desired state of the user. */ + stream->flags |= UV_HANDLE_READING; + stream->flags &= ~UV_HANDLE_READ_EOF; + + /* TODO: try to do the read inline? */ + assert(uv__stream_fd(stream) >= 0); + assert(alloc_cb); + + stream->read_cb = read_cb; + stream->alloc_cb = alloc_cb; + + uv__io_start(stream->loop, &stream->io_watcher, POLLIN); + uv__handle_start(stream); + uv__stream_osx_interrupt_select(stream); + + return 0; +} + + +int uv_read_stop(uv_stream_t* stream) { + if (!(stream->flags & UV_HANDLE_READING)) + return 0; + + stream->flags &= ~UV_HANDLE_READING; + uv__io_stop(stream->loop, &stream->io_watcher, POLLIN); + uv__handle_stop(stream); + uv__stream_osx_interrupt_select(stream); + + stream->read_cb = NULL; + stream->alloc_cb = NULL; + return 0; +} + + +int uv_is_readable(const uv_stream_t* stream) { + return !!(stream->flags & UV_HANDLE_READABLE); +} + + +int uv_is_writable(const uv_stream_t* stream) { + return !!(stream->flags & UV_HANDLE_WRITABLE); +} + + +#if defined(__APPLE__) && !defined(CMAKE_BOOTSTRAP) +int uv___stream_fd(const uv_stream_t* handle) { + const uv__stream_select_t* s; + + assert(handle->type == UV_TCP || + handle->type == UV_TTY || + handle->type == UV_NAMED_PIPE); + + s = handle->select; + if (s != NULL) + return s->fd; + + return handle->io_watcher.fd; +} +#endif /* defined(__APPLE__) */ + + +void uv__stream_close(uv_stream_t* handle) { + unsigned int i; + uv__stream_queued_fds_t* queued_fds; + +#if defined(__APPLE__) && !defined(CMAKE_BOOTSTRAP) + /* Terminate select loop first */ + if (handle->select != NULL) { + uv__stream_select_t* s; + + s = handle->select; + + uv_sem_post(&s->close_sem); + uv_sem_post(&s->async_sem); + uv__stream_osx_interrupt_select(handle); + uv_thread_join(&s->thread); + uv_sem_destroy(&s->close_sem); + uv_sem_destroy(&s->async_sem); + uv__close(s->fake_fd); + uv__close(s->int_fd); + uv_close((uv_handle_t*) &s->async, uv__stream_osx_cb_close); + + handle->select = NULL; + } +#endif /* defined(__APPLE__) */ + + uv__io_close(handle->loop, &handle->io_watcher); + uv_read_stop(handle); + uv__handle_stop(handle); + handle->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE); + + if (handle->io_watcher.fd != -1) { + /* Don't close stdio file descriptors. Nothing good comes from it. */ + if (handle->io_watcher.fd > STDERR_FILENO) + uv__close(handle->io_watcher.fd); + handle->io_watcher.fd = -1; + } + + if (handle->accepted_fd != -1) { + uv__close(handle->accepted_fd); + handle->accepted_fd = -1; + } + + /* Close all queued fds */ + if (handle->queued_fds != NULL) { + queued_fds = handle->queued_fds; + for (i = 0; i < queued_fds->offset; i++) + uv__close(queued_fds->fds[i]); + uv__free(handle->queued_fds); + handle->queued_fds = NULL; + } + + assert(!uv__io_active(&handle->io_watcher, POLLIN | POLLOUT)); +} + + +int uv_stream_set_blocking(uv_stream_t* handle, int blocking) { + /* Don't need to check the file descriptor, uv__nonblock() + * will fail with EBADF if it's not valid. + */ + return uv__nonblock(uv__stream_fd(handle), !blocking); +} |