From 977be04762b9bda29a88d39bb3e2cb7c44b2ad22 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Thu, 16 Apr 2020 09:59:03 +0200
Subject: [PATCH] Revert "freebsd,linux: add recvmmsg() + sendmmsg() udp
implementation"
This reverts commit 3d7136639a39db46bc4a9074922559a564e49514.
This reverts commit d9cd7d437d6bcea56355b6e0ef215aa64687d7a1.
The first reverted commit is the sendmmsg/recvmmsg support, the second
one a fix-up to deliver datagrams in order. The second commit has been
implicated in causing bind9 to crash on freebsd.
A quick review of the code suggests that downstream code written against
pre-v1.35.0 libuv can't safely deal with multi-datagram support because
they are unaware of the `UV_UDP_MMSG_CHUNK` flag and what that implies
for buffer management, hence I'm moving to revert it.
The `UV_UDP_MMSG_CHUNK` flag remains part of `uv_udp_flags` for
API/ABI backwards compatibility reasons but it is no longer used.
Fixes: https://github.com/libuv/libuv/issues/2791
Refs: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=245653
---
docs/src/udp.rst | 18 +---
include/uv.h | 5 +-
src/unix/freebsd.c | 25 -----
src/unix/internal.h | 24 -----
src/unix/linux-syscalls.c | 1 -
src/unix/linux-syscalls.h | 14 +++
src/unix/udp.c | 207 +-------------------------------------
7 files changed, 22 insertions(+), 272 deletions(-)
diff --git a/docs/src/udp.rst b/docs/src/udp.rst
index 786a28b030..53b1fea493 100644
--- a/docs/src/udp.rst
+++ b/docs/src/udp.rst
@@ -42,11 +42,6 @@ Data types
* any traffic, in effect "stealing" the port from the previous listener.
*/
UV_UDP_REUSEADDR = 4
- /*
- * Indicates that the message was received by recvmmsg, so the buffer provided
- * must not be freed by the recv_cb callback.
- */
- UV_UDP_MMSG_CHUNK = 8
};
.. c:type:: void (*uv_udp_send_cb)(uv_udp_send_t* req, int status)
@@ -67,18 +62,13 @@ Data types
* `buf`: :c:type:`uv_buf_t` with the received data.
* `addr`: ``struct sockaddr*`` containing the address of the sender.
Can be NULL. Valid for the duration of the callback only.
- * `flags`: One or more or'ed UV_UDP_* constants.
+ * `flags`: One or more or'ed UV_UDP_* constants. Right now only
+ ``UV_UDP_PARTIAL`` is used.
The callee is responsible for freeing the buffer, libuv does not reuse it.
The buffer may be a null buffer (where `buf->base` == NULL and `buf->len` == 0)
on error.
- When using :man:`recvmmsg(2)`, chunks will have the `UV_UDP_MMSG_CHUNK` flag set,
- those must not be freed. There will be a final callback with `nread` set to 0,
- `addr` set to NULL and the buffer pointing at the initially allocated data with
- the `UV_UDP_MMSG_CHUNK` flag cleared. This is a good chance for the callee to
- free the provided buffer.
-
.. note::
The receive callback will be called with `nread` == 0 and `addr` == NULL when there is
nothing to read, and with `nread` == 0 and `addr` != NULL when an empty UDP packet is
@@ -376,10 +366,6 @@ API
:returns: 0 on success, or an error code < 0 on failure.
- .. versionchanged:: 1.35.0 added support for :man:`recvmmsg(2)` on supported platforms).
- The use of this feature requires a buffer larger than
- 2 * 64KB to be passed to `alloc_cb`.
-
.. c:function:: int uv_udp_recv_stop(uv_udp_t* handle)
Stop listening for incoming datagrams.
diff --git a/include/uv.h b/include/uv.h
index 2e8072fdae..dd8c8a40b0 100644
--- a/include/uv.h
+++ b/include/uv.h
@@ -1,4 +1,4 @@
-/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+/* 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
@@ -607,8 +607,7 @@ enum uv_udp_flags {
*/
UV_UDP_REUSEADDR = 4,
/*
- * Indicates that the message was received by recvmmsg, so the buffer provided
- * must not be freed by the recv_cb callback.
+ * Unused. Here for API/ABI compatibility.
*/
UV_UDP_MMSG_CHUNK = 8
};
diff --git a/src/unix/freebsd.c b/src/unix/freebsd.c
index ef77e127c2..57bd04e240 100644
--- a/src/unix/freebsd.c
+++ b/src/unix/freebsd.c
@@ -288,28 +288,3 @@ int uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
uv__free(cp_times);
return 0;
}
-
-
-int uv__sendmmsg(int fd,
- struct uv__mmsghdr* mmsg,
- unsigned int vlen,
- unsigned int flags) {
-#if __FreeBSD__ >= 11
- return sendmmsg(fd, mmsg, vlen, flags);
-#else
- return errno = ENOSYS, -1;
-#endif
-}
-
-
-int uv__recvmmsg(int fd,
- struct uv__mmsghdr* mmsg,
- unsigned int vlen,
- unsigned int flags,
- struct timespec* timeout) {
-#if __FreeBSD__ >= 11
- return recvmmsg(fd, mmsg, vlen, flags, timeout);
-#else
- return errno = ENOSYS, -1;
-#endif
-}
diff --git a/src/unix/internal.h b/src/unix/internal.h
index 598554b607..469fd7d2b8 100644
--- a/src/unix/internal.h
+++ b/src/unix/internal.h
@@ -31,7 +31,6 @@
#include <fcntl.h> /* O_CLOEXEC and O_NONBLOCK, if supported. */
#include <stdio.h>
#include <errno.h>
-#include <sys/socket.h>
#if defined(__STRICT_ANSI__)
# define inline __inline
@@ -328,27 +327,4 @@ int uv__getsockpeername(const uv_handle_t* handle,
struct sockaddr* name,
int* namelen);
-#if defined(__linux__) || \
- defined(__FreeBSD__) || \
- defined(__FreeBSD_kernel__)
-#define HAVE_MMSG 1
-struct uv__mmsghdr {
- struct msghdr msg_hdr;
- unsigned int msg_len;
-};
-
-int uv__recvmmsg(int fd,
- struct uv__mmsghdr* mmsg,
- unsigned int vlen,
- unsigned int flags,
- struct timespec* timeout);
-int uv__sendmmsg(int fd,
- struct uv__mmsghdr* mmsg,
- unsigned int vlen,
- unsigned int flags);
-#else
-#define HAVE_MMSG 0
-#endif
-
-
#endif /* UV_UNIX_INTERNAL_H_ */
diff --git a/src/unix/linux-syscalls.c b/src/unix/linux-syscalls.c
index 742f26ada8..eb5a8fd274 100644
--- a/src/unix/linux-syscalls.c
+++ b/src/unix/linux-syscalls.c
@@ -126,7 +126,6 @@
# endif
#endif /* __NR_getrandom */
-struct uv__mmsghdr;
int uv__sendmmsg(int fd,
struct uv__mmsghdr* mmsg,
diff --git a/src/unix/linux-syscalls.h b/src/unix/linux-syscalls.h
index 2e8fa2a519..7ee1511a45 100644
--- a/src/unix/linux-syscalls.h
+++ b/src/unix/linux-syscalls.h
@@ -61,6 +61,20 @@ struct uv__statx {
uint64_t unused1[14];
};
+struct uv__mmsghdr {
+ struct msghdr msg_hdr;
+ unsigned int msg_len;
+};
+
+int uv__recvmmsg(int fd,
+ struct uv__mmsghdr* mmsg,
+ unsigned int vlen,
+ unsigned int flags,
+ struct timespec* timeout);
+int uv__sendmmsg(int fd,
+ struct uv__mmsghdr* mmsg,
+ unsigned int vlen,
+ unsigned int flags);
ssize_t uv__preadv(int fd, const struct iovec *iov, int iovcnt, int64_t offset);
ssize_t uv__pwritev(int fd, const struct iovec *iov, int iovcnt, int64_t offset);
int uv__dup3(int oldfd, int newfd, int flags);
diff --git a/src/unix/udp.c b/src/unix/udp.c
index f2fcae1760..982059ff48 100644
--- a/src/unix/udp.c
+++ b/src/unix/udp.c
@@ -32,8 +32,6 @@
#endif
#include <sys/un.h>
-#define UV__UDP_DGRAM_MAXSIZE (64 * 1024)
-
#if defined(IPV6_JOIN_GROUP) && !defined(IPV6_ADD_MEMBERSHIP)
# define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
#endif
@@ -51,36 +49,6 @@ static int uv__udp_maybe_deferred_bind(uv_udp_t* handle,
int domain,
unsigned int flags);
-#if HAVE_MMSG
-
-#define UV__MMSG_MAXWIDTH 20
-
-static int uv__udp_recvmmsg(uv_udp_t* handle, uv_buf_t* buf);
-static void uv__udp_sendmmsg(uv_udp_t* handle);
-
-static int uv__recvmmsg_avail;
-static int uv__sendmmsg_avail;
-static uv_once_t once = UV_ONCE_INIT;
-
-static void uv__udp_mmsg_init(void) {
- int ret;
- int s;
- s = uv__socket(AF_INET, SOCK_DGRAM, 0);
- if (s < 0)
- return;
- ret = uv__sendmmsg(s, NULL, 0, 0);
- if (ret == 0 || errno != ENOSYS) {
- uv__sendmmsg_avail = 1;
- uv__recvmmsg_avail = 1;
- } else {
- ret = uv__recvmmsg(s, NULL, 0, 0, NULL);
- if (ret == 0 || errno != ENOSYS)
- uv__recvmmsg_avail = 1;
- }
- uv__close(s);
-}
-
-#endif
void uv__udp_close(uv_udp_t* handle) {
uv__io_close(handle->loop, &handle->io_watcher);
@@ -180,61 +148,6 @@ static void uv__udp_io(uv_loop_t* loop, uv__io_t* w, unsigned int revents) {
}
}
-#if HAVE_MMSG
-static int uv__udp_recvmmsg(uv_udp_t* handle, uv_buf_t* buf) {
- struct sockaddr_in6 peers[UV__MMSG_MAXWIDTH];
- struct iovec iov[UV__MMSG_MAXWIDTH];
- struct uv__mmsghdr msgs[UV__MMSG_MAXWIDTH];
- ssize_t nread;
- uv_buf_t chunk_buf;
- size_t chunks;
- int flags;
- size_t k;
-
- /* prepare structures for recvmmsg */
- chunks = buf->len / UV__UDP_DGRAM_MAXSIZE;
- if (chunks > ARRAY_SIZE(iov))
- chunks = ARRAY_SIZE(iov);
- for (k = 0; k < chunks; ++k) {
- iov[k].iov_base = buf->base + k * UV__UDP_DGRAM_MAXSIZE;
- iov[k].iov_len = UV__UDP_DGRAM_MAXSIZE;
- msgs[k].msg_hdr.msg_iov = iov + k;
- msgs[k].msg_hdr.msg_iovlen = 1;
- msgs[k].msg_hdr.msg_name = peers + k;
- msgs[k].msg_hdr.msg_namelen = sizeof(peers[0]);
- }
-
- do
- nread = uv__recvmmsg(handle->io_watcher.fd, msgs, chunks, 0, NULL);
- while (nread == -1 && errno == EINTR);
-
- if (nread < 1) {
- if (nread == 0 || errno == EAGAIN || errno == EWOULDBLOCK)
- handle->recv_cb(handle, 0, buf, NULL, 0);
- else
- handle->recv_cb(handle, UV__ERR(errno), buf, NULL, 0);
- } else {
- /* pass each chunk to the application */
- for (k = 0; k < (size_t) nread && handle->recv_cb != NULL; k++) {
- flags = UV_UDP_MMSG_CHUNK;
- if (msgs[k].msg_hdr.msg_flags & MSG_TRUNC)
- flags |= UV_UDP_PARTIAL;
-
- chunk_buf = uv_buf_init(iov[k].iov_base, iov[k].iov_len);
- handle->recv_cb(handle,
- msgs[k].msg_len,
- &chunk_buf,
- msgs[k].msg_hdr.msg_name,
- flags);
- }
-
- /* one last callback so the original buffer is freed */
- if (handle->recv_cb != NULL)
- handle->recv_cb(handle, 0, buf, NULL, 0);
- }
- return nread;
-}
-#endif
static void uv__udp_recvmsg(uv_udp_t* handle) {
struct sockaddr_storage peer;
@@ -254,27 +167,13 @@ static void uv__udp_recvmsg(uv_udp_t* handle) {
do {
buf = uv_buf_init(NULL, 0);
- handle->alloc_cb((uv_handle_t*) handle, UV__UDP_DGRAM_MAXSIZE, &buf);
+ handle->alloc_cb((uv_handle_t*) handle, 64 * 1024, &buf);
if (buf.base == NULL || buf.len == 0) {
handle->recv_cb(handle, UV_ENOBUFS, &buf, NULL, 0);
return;
}
assert(buf.base != NULL);
-#if HAVE_MMSG
- uv_once(&once, uv__udp_mmsg_init);
- if (uv__recvmmsg_avail) {
- /* Returned space for more than 1 datagram, use it to receive
- * multiple datagrams. */
- if (buf.len >= 2 * UV__UDP_DGRAM_MAXSIZE) {
- nread = uv__udp_recvmmsg(handle, &buf);
- if (nread > 0)
- count -= nread;
- continue;
- }
- }
-#endif
-
memset(&h, 0, sizeof(h));
memset(&peer, 0, sizeof(peer));
h.msg_name = &peer;
@@ -300,120 +199,21 @@ static void uv__udp_recvmsg(uv_udp_t* handle) {
handle->recv_cb(handle, nread, &buf, (const struct sockaddr*) &peer, flags);
}
- count--;
}
/* recv_cb callback may decide to pause or close the handle */
while (nread != -1
- && count > 0
+ && count-- > 0
&& handle->io_watcher.fd != -1
&& handle->recv_cb != NULL);
}
-#if HAVE_MMSG
-static void uv__udp_sendmmsg(uv_udp_t* handle) {
- uv_udp_send_t* req;
- struct uv__mmsghdr h[UV__MMSG_MAXWIDTH];
- struct uv__mmsghdr *p;
- QUEUE* q;
- ssize_t npkts;
- size_t pkts;
- size_t i;
-
- if (QUEUE_EMPTY(&handle->write_queue))
- return;
-
-write_queue_drain:
- for (pkts = 0, q = QUEUE_HEAD(&handle->write_queue);
- pkts < UV__MMSG_MAXWIDTH && q != &handle->write_queue;
- ++pkts, q = QUEUE_HEAD(q)) {
- assert(q != NULL);
- req = QUEUE_DATA(q, uv_udp_send_t, queue);
- assert(req != NULL);
-
- p = &h[pkts];
- memset(p, 0, sizeof(*p));
- if (req->addr.ss_family == AF_UNSPEC) {
- p->msg_hdr.msg_name = NULL;
- p->msg_hdr.msg_namelen = 0;
- } else {
- p->msg_hdr.msg_name = &req->addr;
- if (req->addr.ss_family == AF_INET6)
- p->msg_hdr.msg_namelen = sizeof(struct sockaddr_in6);
- else if (req->addr.ss_family == AF_INET)
- p->msg_hdr.msg_namelen = sizeof(struct sockaddr_in);
- else if (req->addr.ss_family == AF_UNIX)
- p->msg_hdr.msg_namelen = sizeof(struct sockaddr_un);
- else {
- assert(0 && "unsupported address family");
- abort();
- }
- }
- h[pkts].msg_hdr.msg_iov = (struct iovec*) req->bufs;
- h[pkts].msg_hdr.msg_iovlen = req->nbufs;
- }
-
- do
- npkts = uv__sendmmsg(handle->io_watcher.fd, h, pkts, 0);
- while (npkts == -1 && errno == EINTR);
-
- if (npkts < 1) {
- if (errno == EAGAIN || errno == EWOULDBLOCK || errno == ENOBUFS)
- return;
- for (i = 0, q = QUEUE_HEAD(&handle->write_queue);
- i < pkts && q != &handle->write_queue;
- ++i, q = QUEUE_HEAD(q)) {
- assert(q != NULL);
- req = QUEUE_DATA(q, uv_udp_send_t, queue);
- assert(req != NULL);
-
- req->status = UV__ERR(errno);
- QUEUE_REMOVE(&req->queue);
- QUEUE_INSERT_TAIL(&handle->write_completed_queue, &req->queue);
- }
- uv__io_feed(handle->loop, &handle->io_watcher);
- return;
- }
-
- for (i = 0, q = QUEUE_HEAD(&handle->write_queue);
- i < pkts && q != &handle->write_queue;
- ++i, q = QUEUE_HEAD(&handle->write_queue)) {
- assert(q != NULL);
- req = QUEUE_DATA(q, uv_udp_send_t, queue);
- assert(req != NULL);
-
- req->status = req->bufs[0].len;
-
- /* Sending a datagram is an atomic operation: either all data
- * is written or nothing is (and EMSGSIZE is raised). That is
- * why we don't handle partial writes. Just pop the request
- * off the write queue and onto the completed queue, done.
- */
- QUEUE_REMOVE(&req->queue);
- QUEUE_INSERT_TAIL(&handle->write_completed_queue, &req->queue);
- }
-
- /* couldn't batch everything, continue sending (jump to avoid stack growth) */
- if (!QUEUE_EMPTY(&handle->write_queue))
- goto write_queue_drain;
- uv__io_feed(handle->loop, &handle->io_watcher);
- return;
-}
-#endif
static void uv__udp_sendmsg(uv_udp_t* handle) {
uv_udp_send_t* req;
- struct msghdr h;
QUEUE* q;
+ struct msghdr h;
ssize_t size;
-#if HAVE_MMSG
- uv_once(&once, uv__udp_mmsg_init);
- if (uv__sendmmsg_avail) {
- uv__udp_sendmmsg(handle);
- return;
- }
-#endif
-
while (!QUEUE_EMPTY(&handle->write_queue)) {
q = QUEUE_HEAD(&handle->write_queue);
assert(q != NULL);
@@ -463,6 +263,7 @@ static void uv__udp_sendmsg(uv_udp_t* handle) {
}
}
+
/* On the BSDs, SO_REUSEPORT implies SO_REUSEADDR but with some additional
* refinements for programs that use multicast.
*
