io_uring: add socket(2) support

Supports both regular socket(2) where a normal file descriptor is
instantiated when called, or direct descriptors.

Link: https://lore.kernel.org/r/20220412202240.234207-3-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2221fe0..bf95ef9 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -576,6 +576,16 @@ struct io_accept {
        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_sync {
        struct file                     *file;
        loff_t                          len;
@@ -951,6 +961,7 @@ struct io_kiocb {
                struct io_hardlink      hardlink;
                struct io_msg           msg;
                struct io_xattr         xattr;
+               struct io_socket        sock;
        };
 
        u8                              opcode;
@@ -1227,6 +1238,9 @@ static const struct io_op_def io_op_defs[] = {
                .needs_file = 1
        },
        [IORING_OP_GETXATTR] = {},
+       [IORING_OP_SOCKET] = {
+               .audit_skip             = 1,
+       },
 };
 
 /* requests with any of those set should undergo io_disarm_next() */
@@ -6017,6 +6031,62 @@ static int io_accept(struct io_kiocb *req, unsigned int issue_flags)
        return 0;
 }
 
+static int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       struct io_socket *sock = &req->sock;
+
+       if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+               return -EINVAL;
+       if (sqe->ioprio || 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;
+}
+
+static int io_socket(struct io_kiocb *req, unsigned int issue_flags)
+{
+       struct io_socket *sock = &req->sock;
+       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_install_fixed_file(req, file, issue_flags,
+                                           sock->file_slot - 1);
+       }
+       __io_req_complete(req, issue_flags, ret, 0);
+       return 0;
+}
+
 static int io_connect_prep_async(struct io_kiocb *req)
 {
        struct io_async_connect *io = req->async_data;
@@ -6105,6 +6175,7 @@ IO_NETOP_PREP_ASYNC(sendmsg);
 IO_NETOP_PREP_ASYNC(recvmsg);
 IO_NETOP_PREP_ASYNC(connect);
 IO_NETOP_PREP(accept);
+IO_NETOP_PREP(socket);
 IO_NETOP_FN(send);
 IO_NETOP_FN(recv);
 #endif /* CONFIG_NET */
@@ -7426,6 +7497,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
                return io_fgetxattr_prep(req, sqe);
        case IORING_OP_GETXATTR:
                return io_getxattr_prep(req, sqe);
+       case IORING_OP_SOCKET:
+               return io_socket_prep(req, sqe);
        }
 
        printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
@@ -7744,6 +7817,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
        case IORING_OP_GETXATTR:
                ret = io_getxattr(req, issue_flags);
                break;
+       case IORING_OP_SOCKET:
+               ret = io_socket(req, issue_flags);
+               break;
        default:
                ret = -EINVAL;
                break;

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 8ca1d9a..5fb52bf 100644 (file)
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -151,6 +151,7 @@ enum {
        IORING_OP_SETXATTR,
        IORING_OP_FGETXATTR,
        IORING_OP_GETXATTR,
+       IORING_OP_SOCKET,
 
        /* this goes last, obviously */
        IORING_OP_LAST,