linux-stable/io_uring/net.c
Dylan Yudaken 9bb66906f2 io_uring: support multishot in recvmsg
Similar to multishot recv, this will require provided buffers to be
used. However recvmsg is much more complex than recv as it has multiple
outputs. Specifically flags, name, and control messages.

Support this by introducing a new struct io_uring_recvmsg_out with 4
fields. namelen, controllen and flags match the similar out fields in
msghdr from standard recvmsg(2), payloadlen is the length of the payload
following the header.
This struct is placed at the start of the returned buffer. Based on what
the user specifies in struct msghdr, the next bytes of the buffer will be
name (the next msg_namelen bytes), and then control (the next
msg_controllen bytes). The payload will come at the end. The return value
in the CQE is the total used size of the provided buffer.

Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220714110258.1336200-4-dylany@fb.com
[axboe: style fixups, see link]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:18 -06:00

1047 lines
25 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/compat.h>
#include <net/compat.h>
#include <linux/io_uring.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "kbuf.h"
#include "alloc_cache.h"
#include "net.h"
#if defined(CONFIG_NET)
struct io_shutdown {
struct file *file;
int how;
};
struct io_accept {
struct file *file;
struct sockaddr __user *addr;
int __user *addr_len;
int flags;
u32 file_slot;
unsigned long nofile;
};
struct io_socket {
struct file *file;
int domain;
int type;
int protocol;
int flags;
u32 file_slot;
unsigned long nofile;
};
struct io_connect {
struct file *file;
struct sockaddr __user *addr;
int addr_len;
};
struct io_sr_msg {
struct file *file;
union {
struct compat_msghdr __user *umsg_compat;
struct user_msghdr __user *umsg;
void __user *buf;
};
int msg_flags;
size_t len;
size_t done_io;
unsigned int flags;
};
#define IO_APOLL_MULTI_POLLED (REQ_F_APOLL_MULTISHOT | REQ_F_POLLED)
int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_shutdown *shutdown = io_kiocb_to_cmd(req);
if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
sqe->buf_index || sqe->splice_fd_in))
return -EINVAL;
shutdown->how = READ_ONCE(sqe->len);
return 0;
}
int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_shutdown *shutdown = io_kiocb_to_cmd(req);
struct socket *sock;
int ret;
if (issue_flags & IO_URING_F_NONBLOCK)
return -EAGAIN;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
ret = __sys_shutdown_sock(sock, shutdown->how);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
static bool io_net_retry(struct socket *sock, int flags)
{
if (!(flags & MSG_WAITALL))
return false;
return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
}
static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_async_msghdr *hdr = req->async_data;
if (!hdr || issue_flags & IO_URING_F_UNLOCKED)
return;
/* Let normal cleanup path reap it if we fail adding to the cache */
if (io_alloc_cache_put(&req->ctx->netmsg_cache, &hdr->cache)) {
req->async_data = NULL;
req->flags &= ~REQ_F_ASYNC_DATA;
}
}
static struct io_async_msghdr *io_recvmsg_alloc_async(struct io_kiocb *req,
unsigned int issue_flags)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_cache_entry *entry;
if (!(issue_flags & IO_URING_F_UNLOCKED) &&
(entry = io_alloc_cache_get(&ctx->netmsg_cache)) != NULL) {
struct io_async_msghdr *hdr;
hdr = container_of(entry, struct io_async_msghdr, cache);
req->flags |= REQ_F_ASYNC_DATA;
req->async_data = hdr;
return hdr;
}
if (!io_alloc_async_data(req))
return req->async_data;
return NULL;
}
static int io_setup_async_msg(struct io_kiocb *req,
struct io_async_msghdr *kmsg,
unsigned int issue_flags)
{
struct io_async_msghdr *async_msg = req->async_data;
if (async_msg)
return -EAGAIN;
async_msg = io_recvmsg_alloc_async(req, issue_flags);
if (!async_msg) {
kfree(kmsg->free_iov);
return -ENOMEM;
}
req->flags |= REQ_F_NEED_CLEANUP;
memcpy(async_msg, kmsg, sizeof(*kmsg));
async_msg->msg.msg_name = &async_msg->addr;
/* if were using fast_iov, set it to the new one */
if (!async_msg->free_iov)
async_msg->msg.msg_iter.iov = async_msg->fast_iov;
return -EAGAIN;
}
static int io_sendmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
iomsg->msg.msg_name = &iomsg->addr;
iomsg->free_iov = iomsg->fast_iov;
return sendmsg_copy_msghdr(&iomsg->msg, sr->umsg, sr->msg_flags,
&iomsg->free_iov);
}
int io_sendmsg_prep_async(struct io_kiocb *req)
{
int ret;
ret = io_sendmsg_copy_hdr(req, req->async_data);
if (!ret)
req->flags |= REQ_F_NEED_CLEANUP;
return ret;
}
void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
{
struct io_async_msghdr *io = req->async_data;
kfree(io->free_iov);
}
int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
if (unlikely(sqe->file_index || sqe->addr2))
return -EINVAL;
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
sr->len = READ_ONCE(sqe->len);
sr->flags = READ_ONCE(sqe->ioprio);
if (sr->flags & ~IORING_RECVSEND_POLL_FIRST)
return -EINVAL;
sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
if (sr->msg_flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
sr->done_io = 0;
return 0;
}
int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
struct io_async_msghdr iomsg, *kmsg;
struct socket *sock;
unsigned flags;
int min_ret = 0;
int ret;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
if (req_has_async_data(req)) {
kmsg = req->async_data;
} else {
ret = io_sendmsg_copy_hdr(req, &iomsg);
if (ret)
return ret;
kmsg = &iomsg;
}
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return io_setup_async_msg(req, kmsg, issue_flags);
flags = sr->msg_flags;
if (issue_flags & IO_URING_F_NONBLOCK)
flags |= MSG_DONTWAIT;
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&kmsg->msg.msg_iter);
ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
if (ret < min_ret) {
if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
return io_setup_async_msg(req, kmsg, issue_flags);
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (ret > 0 && io_net_retry(sock, flags)) {
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return io_setup_async_msg(req, kmsg, issue_flags);
}
req_set_fail(req);
}
/* fast path, check for non-NULL to avoid function call */
if (kmsg->free_iov)
kfree(kmsg->free_iov);
req->flags &= ~REQ_F_NEED_CLEANUP;
io_netmsg_recycle(req, issue_flags);
if (ret >= 0)
ret += sr->done_io;
else if (sr->done_io)
ret = sr->done_io;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_send(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
struct msghdr msg;
struct iovec iov;
struct socket *sock;
unsigned flags;
int min_ret = 0;
int ret;
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return -EAGAIN;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
if (unlikely(ret))
return ret;
msg.msg_name = NULL;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_namelen = 0;
flags = sr->msg_flags;
if (issue_flags & IO_URING_F_NONBLOCK)
flags |= MSG_DONTWAIT;
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&msg.msg_iter);
msg.msg_flags = flags;
ret = sock_sendmsg(sock, &msg);
if (ret < min_ret) {
if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
return -EAGAIN;
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (ret > 0 && io_net_retry(sock, flags)) {
sr->len -= ret;
sr->buf += ret;
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return -EAGAIN;
}
req_set_fail(req);
}
if (ret >= 0)
ret += sr->done_io;
else if (sr->done_io)
ret = sr->done_io;
io_req_set_res(req, ret, 0);
return IOU_OK;
}
static bool io_recvmsg_multishot_overflow(struct io_async_msghdr *iomsg)
{
unsigned long hdr;
if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
(unsigned long)iomsg->namelen, &hdr))
return true;
if (check_add_overflow(hdr, iomsg->controllen, &hdr))
return true;
if (hdr > INT_MAX)
return true;
return false;
}
static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
struct user_msghdr msg;
int ret;
if (copy_from_user(&msg, sr->umsg, sizeof(*sr->umsg)))
return -EFAULT;
ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
if (ret)
return ret;
if (req->flags & REQ_F_BUFFER_SELECT) {
if (msg.msg_iovlen == 0) {
sr->len = iomsg->fast_iov[0].iov_len = 0;
iomsg->fast_iov[0].iov_base = NULL;
iomsg->free_iov = NULL;
} else if (msg.msg_iovlen > 1) {
return -EINVAL;
} else {
if (copy_from_user(iomsg->fast_iov, msg.msg_iov, sizeof(*msg.msg_iov)))
return -EFAULT;
sr->len = iomsg->fast_iov[0].iov_len;
iomsg->free_iov = NULL;
}
if (req->flags & REQ_F_APOLL_MULTISHOT) {
iomsg->namelen = msg.msg_namelen;
iomsg->controllen = msg.msg_controllen;
if (io_recvmsg_multishot_overflow(iomsg))
return -EOVERFLOW;
}
} else {
iomsg->free_iov = iomsg->fast_iov;
ret = __import_iovec(READ, msg.msg_iov, msg.msg_iovlen, UIO_FASTIOV,
&iomsg->free_iov, &iomsg->msg.msg_iter,
false);
if (ret > 0)
ret = 0;
}
return ret;
}
#ifdef CONFIG_COMPAT
static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
struct compat_msghdr msg;
struct compat_iovec __user *uiov;
int ret;
if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))
return -EFAULT;
ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr);
if (ret)
return ret;
uiov = compat_ptr(msg.msg_iov);
if (req->flags & REQ_F_BUFFER_SELECT) {
compat_ssize_t clen;
if (msg.msg_iovlen == 0) {
sr->len = 0;
iomsg->free_iov = NULL;
} else if (msg.msg_iovlen > 1) {
return -EINVAL;
} else {
if (!access_ok(uiov, sizeof(*uiov)))
return -EFAULT;
if (__get_user(clen, &uiov->iov_len))
return -EFAULT;
if (clen < 0)
return -EINVAL;
sr->len = clen;
iomsg->free_iov = NULL;
}
if (req->flags & REQ_F_APOLL_MULTISHOT) {
iomsg->namelen = msg.msg_namelen;
iomsg->controllen = msg.msg_controllen;
if (io_recvmsg_multishot_overflow(iomsg))
return -EOVERFLOW;
}
} else {
iomsg->free_iov = iomsg->fast_iov;
ret = __import_iovec(READ, (struct iovec __user *)uiov, msg.msg_iovlen,
UIO_FASTIOV, &iomsg->free_iov,
&iomsg->msg.msg_iter, true);
if (ret < 0)
return ret;
}
return 0;
}
#endif
static int io_recvmsg_copy_hdr(struct io_kiocb *req,
struct io_async_msghdr *iomsg)
{
iomsg->msg.msg_name = &iomsg->addr;
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
return __io_compat_recvmsg_copy_hdr(req, iomsg);
#endif
return __io_recvmsg_copy_hdr(req, iomsg);
}
int io_recvmsg_prep_async(struct io_kiocb *req)
{
int ret;
ret = io_recvmsg_copy_hdr(req, req->async_data);
if (!ret)
req->flags |= REQ_F_NEED_CLEANUP;
return ret;
}
#define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)
int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
if (unlikely(sqe->file_index || sqe->addr2))
return -EINVAL;
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
sr->len = READ_ONCE(sqe->len);
sr->flags = READ_ONCE(sqe->ioprio);
if (sr->flags & ~(RECVMSG_FLAGS))
return -EINVAL;
sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
if (sr->msg_flags & MSG_DONTWAIT)
req->flags |= REQ_F_NOWAIT;
if (sr->msg_flags & MSG_ERRQUEUE)
req->flags |= REQ_F_CLEAR_POLLIN;
if (sr->flags & IORING_RECV_MULTISHOT) {
if (!(req->flags & REQ_F_BUFFER_SELECT))
return -EINVAL;
if (sr->msg_flags & MSG_WAITALL)
return -EINVAL;
if (req->opcode == IORING_OP_RECV && sr->len)
return -EINVAL;
req->flags |= REQ_F_APOLL_MULTISHOT;
}
#ifdef CONFIG_COMPAT
if (req->ctx->compat)
sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
sr->done_io = 0;
return 0;
}
static inline void io_recv_prep_retry(struct io_kiocb *req)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
sr->done_io = 0;
sr->len = 0; /* get from the provided buffer */
}
/*
* Finishes io_recv and io_recvmsg.
*
* Returns true if it is actually finished, or false if it should run
* again (for multishot).
*/
static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
unsigned int cflags, bool mshot_finished)
{
if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
io_req_set_res(req, *ret, cflags);
*ret = IOU_OK;
return true;
}
if (!mshot_finished) {
if (io_post_aux_cqe(req->ctx, req->cqe.user_data, *ret,
cflags | IORING_CQE_F_MORE, false)) {
io_recv_prep_retry(req);
return false;
}
/*
* Otherwise stop multishot but use the current result.
* Probably will end up going into overflow, but this means
* we cannot trust the ordering anymore
*/
}
io_req_set_res(req, *ret, cflags);
if (req->flags & REQ_F_POLLED)
*ret = IOU_STOP_MULTISHOT;
else
*ret = IOU_OK;
return true;
}
static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
struct io_sr_msg *sr, void __user **buf,
size_t *len)
{
unsigned long ubuf = (unsigned long) *buf;
unsigned long hdr;
hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
kmsg->controllen;
if (*len < hdr)
return -EFAULT;
if (kmsg->controllen) {
unsigned long control = ubuf + hdr - kmsg->controllen;
kmsg->msg.msg_control_user = (void *) control;
kmsg->msg.msg_controllen = kmsg->controllen;
}
sr->buf = *buf; /* stash for later copy */
*buf = (void *) (ubuf + hdr);
kmsg->payloadlen = *len = *len - hdr;
return 0;
}
struct io_recvmsg_multishot_hdr {
struct io_uring_recvmsg_out msg;
struct sockaddr_storage addr;
};
static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
struct io_async_msghdr *kmsg,
unsigned int flags, bool *finished)
{
int err;
int copy_len;
struct io_recvmsg_multishot_hdr hdr;
if (kmsg->namelen)
kmsg->msg.msg_name = &hdr.addr;
kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
kmsg->msg.msg_namelen = 0;
if (sock->file->f_flags & O_NONBLOCK)
flags |= MSG_DONTWAIT;
err = sock_recvmsg(sock, &kmsg->msg, flags);
*finished = err <= 0;
if (err < 0)
return err;
hdr.msg = (struct io_uring_recvmsg_out) {
.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
};
hdr.msg.payloadlen = err;
if (err > kmsg->payloadlen)
err = kmsg->payloadlen;
copy_len = sizeof(struct io_uring_recvmsg_out);
if (kmsg->msg.msg_namelen > kmsg->namelen)
copy_len += kmsg->namelen;
else
copy_len += kmsg->msg.msg_namelen;
/*
* "fromlen shall refer to the value before truncation.."
* 1003.1g
*/
hdr.msg.namelen = kmsg->msg.msg_namelen;
/* ensure that there is no gap between hdr and sockaddr_storage */
BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
sizeof(struct io_uring_recvmsg_out));
if (copy_to_user(io->buf, &hdr, copy_len)) {
*finished = true;
return -EFAULT;
}
return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
kmsg->controllen + err;
}
int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
struct io_async_msghdr iomsg, *kmsg;
struct socket *sock;
unsigned int cflags;
unsigned flags;
int ret, min_ret = 0;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
bool mshot_finished = true;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
if (req_has_async_data(req)) {
kmsg = req->async_data;
} else {
ret = io_recvmsg_copy_hdr(req, &iomsg);
if (ret)
return ret;
kmsg = &iomsg;
}
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return io_setup_async_msg(req, kmsg, issue_flags);
retry_multishot:
if (io_do_buffer_select(req)) {
void __user *buf;
size_t len = sr->len;
buf = io_buffer_select(req, &len, issue_flags);
if (!buf)
return -ENOBUFS;
if (req->flags & REQ_F_APOLL_MULTISHOT) {
ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
if (ret) {
io_kbuf_recycle(req, issue_flags);
return ret;
}
}
kmsg->fast_iov[0].iov_base = buf;
kmsg->fast_iov[0].iov_len = len;
iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov, 1,
len);
}
flags = sr->msg_flags;
if (force_nonblock)
flags |= MSG_DONTWAIT;
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&kmsg->msg.msg_iter);
kmsg->msg.msg_get_inq = 1;
if (req->flags & REQ_F_APOLL_MULTISHOT)
ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
&mshot_finished);
else
ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
kmsg->uaddr, flags);
if (ret < min_ret) {
if (ret == -EAGAIN && force_nonblock) {
ret = io_setup_async_msg(req, kmsg, issue_flags);
if (ret == -EAGAIN && (req->flags & IO_APOLL_MULTI_POLLED) ==
IO_APOLL_MULTI_POLLED) {
io_kbuf_recycle(req, issue_flags);
return IOU_ISSUE_SKIP_COMPLETE;
}
return ret;
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (ret > 0 && io_net_retry(sock, flags)) {
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return io_setup_async_msg(req, kmsg, issue_flags);
}
req_set_fail(req);
} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
req_set_fail(req);
}
if (ret > 0)
ret += sr->done_io;
else if (sr->done_io)
ret = sr->done_io;
else
io_kbuf_recycle(req, issue_flags);
cflags = io_put_kbuf(req, issue_flags);
if (kmsg->msg.msg_inq)
cflags |= IORING_CQE_F_SOCK_NONEMPTY;
if (!io_recv_finish(req, &ret, cflags, mshot_finished))
goto retry_multishot;
if (mshot_finished) {
io_netmsg_recycle(req, issue_flags);
/* fast path, check for non-NULL to avoid function call */
if (kmsg->free_iov)
kfree(kmsg->free_iov);
req->flags &= ~REQ_F_NEED_CLEANUP;
}
return ret;
}
int io_recv(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_sr_msg *sr = io_kiocb_to_cmd(req);
struct msghdr msg;
struct socket *sock;
struct iovec iov;
unsigned int cflags;
unsigned flags;
int ret, min_ret = 0;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
size_t len = sr->len;
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
return -EAGAIN;
sock = sock_from_file(req->file);
if (unlikely(!sock))
return -ENOTSOCK;
retry_multishot:
if (io_do_buffer_select(req)) {
void __user *buf;
buf = io_buffer_select(req, &len, issue_flags);
if (!buf)
return -ENOBUFS;
sr->buf = buf;
}
ret = import_single_range(READ, sr->buf, len, &iov, &msg.msg_iter);
if (unlikely(ret))
goto out_free;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_control = NULL;
msg.msg_get_inq = 1;
msg.msg_flags = 0;
msg.msg_controllen = 0;
msg.msg_iocb = NULL;
flags = sr->msg_flags;
if (force_nonblock)
flags |= MSG_DONTWAIT;
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&msg.msg_iter);
ret = sock_recvmsg(sock, &msg, flags);
if (ret < min_ret) {
if (ret == -EAGAIN && force_nonblock) {
if ((req->flags & IO_APOLL_MULTI_POLLED) == IO_APOLL_MULTI_POLLED) {
io_kbuf_recycle(req, issue_flags);
return IOU_ISSUE_SKIP_COMPLETE;
}
return -EAGAIN;
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
if (ret > 0 && io_net_retry(sock, flags)) {
sr->len -= ret;
sr->buf += ret;
sr->done_io += ret;
req->flags |= REQ_F_PARTIAL_IO;
return -EAGAIN;
}
req_set_fail(req);
} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
out_free:
req_set_fail(req);
}
if (ret > 0)
ret += sr->done_io;
else if (sr->done_io)
ret = sr->done_io;
else
io_kbuf_recycle(req, issue_flags);
cflags = io_put_kbuf(req, issue_flags);
if (msg.msg_inq)
cflags |= IORING_CQE_F_SOCK_NONEMPTY;
if (!io_recv_finish(req, &ret, cflags, ret <= 0))
goto retry_multishot;
return ret;
}
int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_accept *accept = io_kiocb_to_cmd(req);
unsigned flags;
if (sqe->len || sqe->buf_index)
return -EINVAL;
accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
accept->flags = READ_ONCE(sqe->accept_flags);
accept->nofile = rlimit(RLIMIT_NOFILE);
flags = READ_ONCE(sqe->ioprio);
if (flags & ~IORING_ACCEPT_MULTISHOT)
return -EINVAL;
accept->file_slot = READ_ONCE(sqe->file_index);
if (accept->file_slot) {
if (accept->flags & SOCK_CLOEXEC)
return -EINVAL;
if (flags & IORING_ACCEPT_MULTISHOT &&
accept->file_slot != IORING_FILE_INDEX_ALLOC)
return -EINVAL;
}
if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
return -EINVAL;
if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
if (flags & IORING_ACCEPT_MULTISHOT)
req->flags |= REQ_F_APOLL_MULTISHOT;
return 0;
}
int io_accept(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_accept *accept = io_kiocb_to_cmd(req);
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
bool fixed = !!accept->file_slot;
struct file *file;
int ret, fd;
retry:
if (!fixed) {
fd = __get_unused_fd_flags(accept->flags, accept->nofile);
if (unlikely(fd < 0))
return fd;
}
file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
accept->flags);
if (IS_ERR(file)) {
if (!fixed)
put_unused_fd(fd);
ret = PTR_ERR(file);
if (ret == -EAGAIN && force_nonblock) {
/*
* if it's multishot and polled, we don't need to
* return EAGAIN to arm the poll infra since it
* has already been done
*/
if ((req->flags & IO_APOLL_MULTI_POLLED) ==
IO_APOLL_MULTI_POLLED)
ret = IOU_ISSUE_SKIP_COMPLETE;
return ret;
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
req_set_fail(req);
} else if (!fixed) {
fd_install(fd, file);
ret = fd;
} else {
ret = io_fixed_fd_install(req, issue_flags, file,
accept->file_slot);
}
if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
io_req_set_res(req, ret, 0);
return IOU_OK;
}
if (ret >= 0 &&
io_post_aux_cqe(ctx, req->cqe.user_data, ret, IORING_CQE_F_MORE, false))
goto retry;
io_req_set_res(req, ret, 0);
if (req->flags & REQ_F_POLLED)
return IOU_STOP_MULTISHOT;
return IOU_OK;
}
int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_socket *sock = io_kiocb_to_cmd(req);
if (sqe->addr || sqe->rw_flags || sqe->buf_index)
return -EINVAL;
sock->domain = READ_ONCE(sqe->fd);
sock->type = READ_ONCE(sqe->off);
sock->protocol = READ_ONCE(sqe->len);
sock->file_slot = READ_ONCE(sqe->file_index);
sock->nofile = rlimit(RLIMIT_NOFILE);
sock->flags = sock->type & ~SOCK_TYPE_MASK;
if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
return -EINVAL;
if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
return -EINVAL;
return 0;
}
int io_socket(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_socket *sock = io_kiocb_to_cmd(req);
bool fixed = !!sock->file_slot;
struct file *file;
int ret, fd;
if (!fixed) {
fd = __get_unused_fd_flags(sock->flags, sock->nofile);
if (unlikely(fd < 0))
return fd;
}
file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
if (IS_ERR(file)) {
if (!fixed)
put_unused_fd(fd);
ret = PTR_ERR(file);
if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
return -EAGAIN;
if (ret == -ERESTARTSYS)
ret = -EINTR;
req_set_fail(req);
} else if (!fixed) {
fd_install(fd, file);
ret = fd;
} else {
ret = io_fixed_fd_install(req, issue_flags, file,
sock->file_slot);
}
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_connect_prep_async(struct io_kiocb *req)
{
struct io_async_connect *io = req->async_data;
struct io_connect *conn = io_kiocb_to_cmd(req);
return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
}
int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_connect *conn = io_kiocb_to_cmd(req);
if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
return -EINVAL;
conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
conn->addr_len = READ_ONCE(sqe->addr2);
return 0;
}
int io_connect(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_connect *connect = io_kiocb_to_cmd(req);
struct io_async_connect __io, *io;
unsigned file_flags;
int ret;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
if (req_has_async_data(req)) {
io = req->async_data;
} else {
ret = move_addr_to_kernel(connect->addr,
connect->addr_len,
&__io.address);
if (ret)
goto out;
io = &__io;
}
file_flags = force_nonblock ? O_NONBLOCK : 0;
ret = __sys_connect_file(req->file, &io->address,
connect->addr_len, file_flags);
if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
if (req_has_async_data(req))
return -EAGAIN;
if (io_alloc_async_data(req)) {
ret = -ENOMEM;
goto out;
}
memcpy(req->async_data, &__io, sizeof(__io));
return -EAGAIN;
}
if (ret == -ERESTARTSYS)
ret = -EINTR;
out:
if (ret < 0)
req_set_fail(req);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
void io_netmsg_cache_free(struct io_cache_entry *entry)
{
kfree(container_of(entry, struct io_async_msghdr, cache));
}
#endif