| /* |
| * Copyright (c) 2021 Nutanix Inc. All rights reserved. |
| * |
| * Authors: Thanos Makatos <thanos@nutanix.com> |
| * Swapnil Ingle <swapnil.ingle@nutanix.com> |
| * Felipe Franciosi <felipe@nutanix.com> |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * * Neither the name of Nutanix nor the names of its contributors may be |
| * used to endorse or promote products derived from this software without |
| * specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
| * DAMAGE. |
| * |
| */ |
| |
| #include <sys/param.h> |
| #include <assert.h> |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <strings.h> |
| |
| #include "tran_pipe.h" |
| |
| typedef struct { |
| int in_fd; |
| int out_fd; |
| } tran_pipe_t; |
| |
| static int |
| tran_pipe_send_iovec(int fd, uint16_t msg_id, bool is_reply, |
| enum vfio_user_command cmd, |
| struct iovec *iovecs, size_t nr_iovecs, int err) |
| { |
| struct vfio_user_header hdr = { .msg_id = msg_id }; |
| ssize_t ret; |
| |
| if (nr_iovecs == 0) { |
| iovecs = alloca(sizeof(*iovecs)); |
| nr_iovecs = 1; |
| } |
| |
| if (is_reply) { |
| hdr.flags |= VFIO_USER_F_TYPE_REPLY; |
| hdr.cmd = cmd; |
| if (err != 0) { |
| hdr.flags |= VFIO_USER_F_ERROR; |
| hdr.error_no = err; |
| } |
| } else { |
| hdr.cmd = cmd; |
| hdr.flags |= VFIO_USER_F_TYPE_COMMAND; |
| } |
| |
| iovecs[0].iov_base = &hdr; |
| iovecs[0].iov_len = sizeof(hdr); |
| |
| ret = writev(fd, iovecs, nr_iovecs); |
| |
| /* Quieten static analysis. */ |
| iovecs[0].iov_base = NULL; |
| iovecs[0].iov_len = 0; |
| |
| if (ret == -1) { |
| /* Treat a failed write due to EPIPE the same as a short write. */ |
| if (errno == EPIPE) { |
| return ERROR_INT(ECONNRESET); |
| } |
| return -1; |
| } else if (ret < (ssize_t)hdr.msg_size) { |
| return ERROR_INT(ECONNRESET); |
| } |
| |
| return 0; |
| } |
| |
| static int |
| tran_pipe_get_msg(void *data, size_t len, int fd) |
| { |
| ssize_t ret; |
| |
| ret = read(fd, data, len); |
| |
| if (ret == -1) { |
| return -1; |
| } else if (ret == 0) { |
| return ERROR_INT(ENOMSG); |
| } else if ((size_t)ret < len) { |
| return ERROR_INT(ECONNRESET); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Receive a vfio-user message. If "len" is set to non-zero, the message should |
| * include data of that length, which is stored in the pre-allocated "data" |
| * pointer. |
| */ |
| static int |
| tran_pipe_recv(int fd, struct vfio_user_header *hdr, bool is_reply, |
| uint16_t *msg_id, void *data, size_t *len) |
| { |
| int ret; |
| |
| /* FIXME if ret == -1 then fcntl can overwrite recv's errno */ |
| |
| ret = tran_pipe_get_msg(hdr, sizeof(*hdr), fd); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| if (is_reply) { |
| if (msg_id != NULL && hdr->msg_id != *msg_id) { |
| return ERROR_INT(EPROTO); |
| } |
| |
| if ((hdr->flags & VFIO_USER_F_TYPE_MASK) != VFIO_USER_F_TYPE_REPLY) { |
| return ERROR_INT(EINVAL); |
| } |
| |
| if (hdr->flags & VFIO_USER_F_ERROR) { |
| if (hdr->error_no <= 0) { |
| hdr->error_no = EINVAL; |
| } |
| return ERROR_INT(hdr->error_no); |
| } |
| } else { |
| if ((hdr->flags & VFIO_USER_F_TYPE_MASK) != VFIO_USER_F_TYPE_COMMAND) { |
| return ERROR_INT(EINVAL); |
| } |
| if (msg_id != NULL) { |
| *msg_id = hdr->msg_id; |
| } |
| } |
| |
| if (hdr->msg_size < sizeof(*hdr) || hdr->msg_size > SERVER_MAX_MSG_SIZE) { |
| return ERROR_INT(EINVAL); |
| } |
| |
| if (len != NULL && *len > 0 && hdr->msg_size > sizeof(*hdr)) { |
| ret = read(fd, data, MIN(hdr->msg_size - sizeof(*hdr), *len)); |
| if (ret < 0) { |
| return -1; |
| } else if (ret == 0) { |
| return ERROR_INT(ENOMSG); |
| } else if (*len != (size_t)ret) { |
| return ERROR_INT(ECONNRESET); |
| } |
| *len = ret; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Like tran_pipe_recv(), but will automatically allocate reply data. |
| */ |
| static int |
| tran_pipe_recv_alloc(int fd, struct vfio_user_header *hdr, bool is_reply, |
| uint16_t *msg_id, void **datap, size_t *lenp) |
| { |
| void *data; |
| size_t len; |
| int ret; |
| |
| ret = tran_pipe_recv(fd, hdr, is_reply, msg_id, NULL, NULL); |
| |
| if (ret != 0) { |
| return ret; |
| } |
| |
| assert(hdr->msg_size >= sizeof(*hdr)); |
| assert(hdr->msg_size <= SERVER_MAX_MSG_SIZE); |
| |
| len = hdr->msg_size - sizeof(*hdr); |
| |
| if (len == 0) { |
| *datap = NULL; |
| *lenp = 0; |
| return 0; |
| } |
| |
| data = calloc(1, len); |
| |
| if (data == NULL) { |
| return -1; |
| } |
| |
| ret = read(fd, data, len); |
| if (ret < 0) { |
| ret = errno; |
| free(data); |
| return ERROR_INT(ret); |
| } else if (ret == 0) { |
| free(data); |
| return ERROR_INT(ENOMSG); |
| } else if (len != (size_t)ret) { |
| free(data); |
| return ERROR_INT(ECONNRESET); |
| } |
| |
| *datap = data; |
| *lenp = len; |
| return 0; |
| } |
| |
| /* |
| * FIXME: all these send/recv handlers need to be made robust against async |
| * messages. |
| */ |
| static int |
| tran_pipe_msg_iovec(tran_pipe_t *tp, uint16_t msg_id, |
| enum vfio_user_command cmd, |
| struct iovec *iovecs, size_t nr_iovecs, |
| struct vfio_user_header *hdr, |
| void *recv_data, size_t recv_len) |
| { |
| int ret = tran_pipe_send_iovec(tp->out_fd, msg_id, false, cmd, iovecs, |
| nr_iovecs, 0); |
| if (ret < 0) { |
| return ret; |
| } |
| if (hdr == NULL) { |
| hdr = alloca(sizeof(*hdr)); |
| } |
| return tran_pipe_recv(tp->in_fd, hdr, true, &msg_id, recv_data, &recv_len); |
| } |
| |
| static int |
| tran_pipe_init(vfu_ctx_t *vfu_ctx) |
| { |
| tran_pipe_t *tp = NULL; |
| |
| assert(vfu_ctx != NULL); |
| |
| tp = calloc(1, sizeof(tran_pipe_t)); |
| |
| if (tp == NULL) { |
| return -1; |
| } |
| |
| tp->in_fd = -1; |
| tp->out_fd = -1; |
| |
| vfu_ctx->tran_data = tp; |
| return 0; |
| } |
| |
| static int |
| tran_pipe_get_poll_fd(vfu_ctx_t *vfu_ctx) |
| { |
| tran_pipe_t *tp = vfu_ctx->tran_data; |
| |
| return tp->in_fd; |
| } |
| |
| static int |
| tran_pipe_attach(vfu_ctx_t *vfu_ctx) |
| { |
| tran_pipe_t *tp; |
| int ret; |
| |
| assert(vfu_ctx != NULL); |
| assert(vfu_ctx->tran_data != NULL); |
| |
| tp = vfu_ctx->tran_data; |
| |
| tp->in_fd = STDIN_FILENO; |
| tp->out_fd = STDOUT_FILENO; |
| |
| ret = tran_negotiate(vfu_ctx, NULL); |
| if (ret < 0) { |
| ret = errno; |
| tp->in_fd = -1; |
| tp->out_fd = -1; |
| return ERROR_INT(ret); |
| } |
| |
| return 0; |
| } |
| |
| static int |
| tran_pipe_get_request_header(vfu_ctx_t *vfu_ctx, struct vfio_user_header *hdr, |
| int *fds UNUSED, size_t *nr_fds) |
| { |
| tran_pipe_t *tp; |
| |
| assert(vfu_ctx != NULL); |
| assert(vfu_ctx->tran_data != NULL); |
| |
| tp = vfu_ctx->tran_data; |
| |
| *nr_fds = 0; |
| |
| return tran_pipe_get_msg(hdr, sizeof(*hdr), tp->in_fd); |
| } |
| |
| static int |
| tran_pipe_recv_body(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg) |
| { |
| tran_pipe_t *tp; |
| int ret; |
| |
| assert(vfu_ctx != NULL); |
| assert(vfu_ctx->tran_data != NULL); |
| assert(msg != NULL); |
| |
| tp = vfu_ctx->tran_data; |
| |
| assert(msg->in.iov.iov_len <= SERVER_MAX_MSG_SIZE); |
| |
| msg->in.iov.iov_base = malloc(msg->in.iov.iov_len); |
| |
| if (msg->in.iov.iov_base == NULL) { |
| return -1; |
| } |
| |
| ret = read(tp->in_fd, msg->in.iov.iov_base, msg->in.iov.iov_len); |
| |
| if (ret < 0) { |
| ret = errno; |
| free(msg->in.iov.iov_base); |
| msg->in.iov.iov_base = NULL; |
| return ERROR_INT(ret); |
| } else if (ret == 0) { |
| free(msg->in.iov.iov_base); |
| msg->in.iov.iov_base = NULL; |
| return ERROR_INT(ENOMSG); |
| } else if (ret != (int)msg->in.iov.iov_len) { |
| vfu_log(vfu_ctx, LOG_ERR, "msg%#hx: short read: expected=%zu, actual=%d", |
| msg->hdr.msg_id, msg->in.iov.iov_len, ret); |
| free(msg->in.iov.iov_base); |
| msg->in.iov.iov_base = NULL; |
| return ERROR_INT(EINVAL); |
| } |
| |
| return 0; |
| } |
| |
| static int |
| tran_pipe_recv_msg(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg) |
| { |
| tran_pipe_t *tp; |
| |
| assert(vfu_ctx != NULL); |
| assert(vfu_ctx->tran_data != NULL); |
| assert(msg != NULL); |
| |
| tp = vfu_ctx->tran_data; |
| |
| if (tp->in_fd == -1) { |
| vfu_log(vfu_ctx, LOG_ERR, "%s: not connected", __func__); |
| return ERROR_INT(ENOTCONN); |
| } |
| |
| return tran_pipe_recv_alloc(tp->in_fd, &msg->hdr, false, NULL, |
| &msg->in.iov.iov_base, &msg->in.iov.iov_len); |
| } |
| |
| static int |
| tran_pipe_reply(vfu_ctx_t *vfu_ctx, vfu_msg_t *msg, int err) |
| { |
| struct iovec *iovecs; |
| size_t nr_iovecs; |
| tran_pipe_t *tp; |
| int ret; |
| |
| assert(vfu_ctx != NULL); |
| assert(vfu_ctx->tran_data != NULL); |
| assert(msg != NULL); |
| |
| tp = vfu_ctx->tran_data; |
| |
| /* First iovec entry is for msg header. */ |
| nr_iovecs = (msg->nr_out_iovecs != 0) ? (msg->nr_out_iovecs + 1) : 2; |
| iovecs = calloc(nr_iovecs, sizeof(*iovecs)); |
| |
| if (iovecs == NULL) { |
| return -1; |
| } |
| |
| if (msg->out_iovecs != NULL) { |
| memcpy(iovecs + 1, msg->out_iovecs, |
| msg->nr_out_iovecs * sizeof(*iovecs)); |
| } else { |
| iovecs[1].iov_base = msg->out.iov.iov_base; |
| iovecs[1].iov_len = msg->out.iov.iov_len; |
| } |
| |
| ret = tran_pipe_send_iovec(tp->out_fd, msg->hdr.msg_id, true, msg->hdr.cmd, |
| iovecs, nr_iovecs, err); |
| |
| free(iovecs); |
| |
| return ret; |
| } |
| |
| static int |
| tran_pipe_send_msg(vfu_ctx_t *vfu_ctx, uint16_t msg_id, |
| enum vfio_user_command cmd, |
| void *send_data, size_t send_len, |
| struct vfio_user_header *hdr, |
| void *recv_data, size_t recv_len) |
| { |
| /* [0] is for the header. */ |
| struct iovec iovecs[2] = { |
| [1] = { |
| .iov_base = send_data, |
| .iov_len = send_len |
| } |
| }; |
| tran_pipe_t *tp; |
| |
| assert(vfu_ctx != NULL); |
| assert(vfu_ctx->tran_data != NULL); |
| |
| tp = vfu_ctx->tran_data; |
| |
| return tran_pipe_msg_iovec(tp, msg_id, cmd, iovecs, ARRAY_SIZE(iovecs), |
| hdr, recv_data, recv_len); |
| } |
| |
| static void |
| tran_pipe_detach(vfu_ctx_t *vfu_ctx) |
| { |
| assert(vfu_ctx != NULL); |
| } |
| |
| static void |
| tran_pipe_fini(vfu_ctx_t *vfu_ctx) |
| { |
| assert(vfu_ctx != NULL); |
| |
| free(vfu_ctx->tran_data); |
| vfu_ctx->tran_data = NULL; |
| } |
| |
| struct transport_ops tran_pipe_ops = { |
| .init = tran_pipe_init, |
| .get_poll_fd = tran_pipe_get_poll_fd, |
| .attach = tran_pipe_attach, |
| .get_request_header = tran_pipe_get_request_header, |
| .recv_body = tran_pipe_recv_body, |
| .reply = tran_pipe_reply, |
| .recv_msg = tran_pipe_recv_msg, |
| .send_msg = tran_pipe_send_msg, |
| .detach = tran_pipe_detach, |
| .fini = tran_pipe_fini |
| }; |
| |
| /* ex: set tabstop=4 shiftwidth=4 softtabstop=4 expandtab: */ |
