Current Netlink message writer code relies on executing callbacks with arbitrary data (pointer or integer) to flush the completed messages. This arbitrary data is stored as a union of { void *, uint64_t }. At some stage, the message flushing code copied this data, using direct uint64_t assignment instead of copying the union. It lead to failure on CHERI, as sizeof(pointer) == 16 there. Fix the code by making union non-anonymous and copying it entirely. Reviewed by: br, jhb, jrtc27 Differential Revision: https://reviews.freebsd.org/D39557 MFC after: 2 weeks
694 lines
19 KiB
C
694 lines
19 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "opt_netlink.h"
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/malloc.h>
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#include <sys/lock.h>
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#include <sys/rmlock.h>
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#include <sys/mbuf.h>
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#include <sys/ck.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/syslog.h>
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#include <netlink/netlink.h>
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#include <netlink/netlink_ctl.h>
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#include <netlink/netlink_linux.h>
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#include <netlink/netlink_var.h>
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#define DEBUG_MOD_NAME nl_writer
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#define DEBUG_MAX_LEVEL LOG_DEBUG3
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#include <netlink/netlink_debug.h>
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_DECLARE_DEBUG(LOG_DEBUG);
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/*
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* The goal of this file is to provide convenient message writing KPI on top of
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* different storage methods (mbufs, uio, temporary memory chunks).
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*
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* The main KPI guarantee is the the (last) message always resides in the contiguous
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* memory buffer, so one is able to update the header after writing the entire message.
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*
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* This guarantee comes with a side effect of potentially reallocating underlying
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* buffer, so one needs to update the desired pointers after something is added
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* to the header.
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*
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* Messaging layer contains hooks performing transparent Linux translation for the messages.
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*
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* There are 3 types of supported targets:
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* * socket (adds mbufs to the socket buffer, used for message replies)
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* * group (sends mbuf/chain to the specified groups, used for the notifications)
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* * chain (returns mbuf chain, used in Linux message translation code)
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*
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* There are 3 types of storage:
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* * NS_WRITER_TYPE_MBUF (mbuf-based, most efficient, used when a single message
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* fits in MCLBYTES)
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* * NS_WRITER_TYPE_BUF (fallback, malloc-based, used when a single message needs
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* to be larger than one supported by NS_WRITER_TYPE_MBUF)
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* * NS_WRITER_TYPE_LBUF (malloc-based, similar to NS_WRITER_TYPE_BUF, used for
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* Linux sockets, calls translation hook prior to sending messages to the socket).
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*
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* Internally, KPI switches between different types of storage when memory requirements
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* change. It happens transparently to the caller.
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*/
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typedef bool nlwriter_op_init(struct nl_writer *nw, int size, bool waitok);
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typedef bool nlwriter_op_write(struct nl_writer *nw, void *buf, int buflen, int cnt);
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struct nlwriter_ops {
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nlwriter_op_init *init;
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nlwriter_op_write *write_socket;
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nlwriter_op_write *write_group;
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nlwriter_op_write *write_chain;
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};
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/*
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* NS_WRITER_TYPE_BUF
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* Writes message to a temporary memory buffer,
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* flushing to the socket/group when buffer size limit is reached
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*/
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static bool
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nlmsg_get_ns_buf(struct nl_writer *nw, int size, bool waitok)
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{
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int mflag = waitok ? M_WAITOK : M_NOWAIT;
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nw->_storage = malloc(size, M_NETLINK, mflag | M_ZERO);
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if (__predict_false(nw->_storage == NULL))
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return (false);
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nw->alloc_len = size;
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nw->offset = 0;
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nw->hdr = NULL;
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nw->data = nw->_storage;
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nw->writer_type = NS_WRITER_TYPE_BUF;
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nw->malloc_flag = mflag;
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nw->num_messages = 0;
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nw->enomem = false;
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return (true);
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}
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static bool
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nlmsg_write_socket_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
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if (__predict_false(datalen == 0)) {
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free(buf, M_NETLINK);
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return (true);
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}
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struct mbuf *m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR);
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if (__predict_false(m == NULL)) {
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/* XXX: should we set sorcverr? */
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free(buf, M_NETLINK);
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return (false);
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}
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m_append(m, datalen, buf);
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free(buf, M_NETLINK);
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int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0;
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return (nl_send_one(m, (struct nlpcb *)(nw->arg.ptr), cnt, io_flags));
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}
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static bool
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nlmsg_write_group_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d proto: %d id: %d", buf, datalen,
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nw->arg.group.proto, nw->arg.group.id);
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if (__predict_false(datalen == 0)) {
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free(buf, M_NETLINK);
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return (true);
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}
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struct mbuf *m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR);
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if (__predict_false(m == NULL)) {
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free(buf, M_NETLINK);
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return (false);
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}
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bool success = m_append(m, datalen, buf) != 0;
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free(buf, M_NETLINK);
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if (!success)
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return (false);
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nl_send_group(m, cnt, nw->arg.group.proto, nw->arg.group.id);
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return (true);
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}
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static bool
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nlmsg_write_chain_buf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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struct mbuf **m0 = (struct mbuf **)(nw->arg.ptr);
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NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
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if (__predict_false(datalen == 0)) {
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free(buf, M_NETLINK);
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return (true);
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}
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if (*m0 == NULL) {
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struct mbuf *m;
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m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR);
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if (__predict_false(m == NULL)) {
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free(buf, M_NETLINK);
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return (false);
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}
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*m0 = m;
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}
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if (__predict_false(m_append(*m0, datalen, buf) == 0)) {
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free(buf, M_NETLINK);
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return (false);
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}
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return (true);
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}
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/*
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* NS_WRITER_TYPE_MBUF
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* Writes message to the allocated mbuf,
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* flushing to socket/group when mbuf size limit is reached.
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* This is the most efficient mechanism as it avoids double-copying.
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*
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* Allocates a single mbuf suitable to store up to @size bytes of data.
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* If size < MHLEN (around 160 bytes), allocates mbuf with pkghdr
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* If size <= MCLBYTES (2k), allocate a single mbuf cluster
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* Otherwise, return NULL.
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*/
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static bool
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nlmsg_get_ns_mbuf(struct nl_writer *nw, int size, bool waitok)
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{
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struct mbuf *m;
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int mflag = waitok ? M_WAITOK : M_NOWAIT;
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m = m_get2(size, mflag, MT_DATA, M_PKTHDR);
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if (__predict_false(m == NULL))
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return (false);
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nw->alloc_len = M_TRAILINGSPACE(m);
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nw->offset = 0;
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nw->hdr = NULL;
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nw->_storage = (void *)m;
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nw->data = mtod(m, void *);
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nw->writer_type = NS_WRITER_TYPE_MBUF;
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nw->malloc_flag = mflag;
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nw->num_messages = 0;
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nw->enomem = false;
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memset(nw->data, 0, size);
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NL_LOG(LOG_DEBUG2, "alloc mbuf %p req_len %d alloc_len %d data_ptr %p",
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m, size, nw->alloc_len, nw->data);
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return (true);
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}
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static bool
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nlmsg_write_socket_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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struct mbuf *m = (struct mbuf *)buf;
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NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
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if (__predict_false(datalen == 0)) {
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m_freem(m);
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return (true);
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}
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m->m_pkthdr.len = datalen;
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m->m_len = datalen;
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int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0;
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return (nl_send_one(m, (struct nlpcb *)(nw->arg.ptr), cnt, io_flags));
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}
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static bool
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nlmsg_write_group_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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struct mbuf *m = (struct mbuf *)buf;
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NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d proto: %d id: %d", buf, datalen,
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nw->arg.group.proto, nw->arg.group.id);
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if (__predict_false(datalen == 0)) {
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m_freem(m);
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return (true);
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}
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m->m_pkthdr.len = datalen;
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m->m_len = datalen;
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nl_send_group(m, cnt, nw->arg.group.proto, nw->arg.group.id);
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return (true);
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}
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static bool
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nlmsg_write_chain_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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struct mbuf *m_new = (struct mbuf *)buf;
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struct mbuf **m0 = (struct mbuf **)(nw->arg.ptr);
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NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg.ptr);
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if (__predict_false(datalen == 0)) {
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m_freem(m_new);
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return (true);
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}
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m_new->m_pkthdr.len = datalen;
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m_new->m_len = datalen;
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if (*m0 == NULL) {
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*m0 = m_new;
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} else {
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struct mbuf *m_last;
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for (m_last = *m0; m_last->m_next != NULL; m_last = m_last->m_next)
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;
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m_last->m_next = m_new;
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(*m0)->m_pkthdr.len += datalen;
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}
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return (true);
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}
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/*
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* NS_WRITER_TYPE_LBUF
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* Writes message to the allocated memory buffer,
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* flushing to socket/group when mbuf size limit is reached.
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* Calls linux handler to rewrite messages before sending to the socket.
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*/
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static bool
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nlmsg_get_ns_lbuf(struct nl_writer *nw, int size, bool waitok)
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{
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int mflag = waitok ? M_WAITOK : M_NOWAIT;
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size = roundup2(size, sizeof(void *));
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int add_size = sizeof(struct linear_buffer) + SCRATCH_BUFFER_SIZE;
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char *buf = malloc(add_size + size * 2, M_NETLINK, mflag | M_ZERO);
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if (__predict_false(buf == NULL))
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return (false);
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/* Fill buffer header first */
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struct linear_buffer *lb = (struct linear_buffer *)buf;
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lb->base = &buf[sizeof(struct linear_buffer) + size];
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lb->size = size + SCRATCH_BUFFER_SIZE;
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nw->alloc_len = size;
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nw->offset = 0;
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nw->hdr = NULL;
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nw->_storage = buf;
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nw->data = (char *)(lb + 1);
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nw->malloc_flag = mflag;
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nw->writer_type = NS_WRITER_TYPE_LBUF;
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nw->num_messages = 0;
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nw->enomem = false;
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return (true);
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}
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static bool
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nlmsg_write_socket_lbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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struct linear_buffer *lb = (struct linear_buffer *)buf;
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char *data = (char *)(lb + 1);
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struct nlpcb *nlp = (struct nlpcb *)(nw->arg.ptr);
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if (__predict_false(datalen == 0)) {
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free(buf, M_NETLINK);
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return (true);
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}
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struct mbuf *m = NULL;
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if (linux_netlink_p != NULL)
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m = linux_netlink_p->msgs_to_linux(nlp->nl_proto, data, datalen, nlp);
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free(buf, M_NETLINK);
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if (__predict_false(m == NULL)) {
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/* XXX: should we set sorcverr? */
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return (false);
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}
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int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0;
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return (nl_send_one(m, nlp, cnt, io_flags));
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}
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/* Shouldn't be called (maybe except Linux code originating message) */
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static bool
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nlmsg_write_group_lbuf(struct nl_writer *nw, void *buf, int datalen, int cnt)
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{
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struct linear_buffer *lb = (struct linear_buffer *)buf;
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char *data = (char *)(lb + 1);
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if (__predict_false(datalen == 0)) {
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free(buf, M_NETLINK);
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return (true);
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}
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struct mbuf *m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR);
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if (__predict_false(m == NULL)) {
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free(buf, M_NETLINK);
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return (false);
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}
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m_append(m, datalen, data);
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free(buf, M_NETLINK);
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nl_send_group(m, cnt, nw->arg.group.proto, nw->arg.group.id);
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return (true);
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}
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static const struct nlwriter_ops nlmsg_writers[] = {
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/* NS_WRITER_TYPE_MBUF */
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{
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.init = nlmsg_get_ns_mbuf,
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.write_socket = nlmsg_write_socket_mbuf,
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.write_group = nlmsg_write_group_mbuf,
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.write_chain = nlmsg_write_chain_mbuf,
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},
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/* NS_WRITER_TYPE_BUF */
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{
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.init = nlmsg_get_ns_buf,
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.write_socket = nlmsg_write_socket_buf,
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.write_group = nlmsg_write_group_buf,
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.write_chain = nlmsg_write_chain_buf,
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},
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/* NS_WRITER_TYPE_LBUF */
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{
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.init = nlmsg_get_ns_lbuf,
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.write_socket = nlmsg_write_socket_lbuf,
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.write_group = nlmsg_write_group_lbuf,
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},
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};
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static void
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nlmsg_set_callback(struct nl_writer *nw)
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{
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const struct nlwriter_ops *pops = &nlmsg_writers[nw->writer_type];
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switch (nw->writer_target) {
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case NS_WRITER_TARGET_SOCKET:
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nw->cb = pops->write_socket;
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break;
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case NS_WRITER_TARGET_GROUP:
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nw->cb = pops->write_group;
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break;
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case NS_WRITER_TARGET_CHAIN:
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nw->cb = pops->write_chain;
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break;
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default:
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panic("not implemented");
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}
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}
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static bool
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nlmsg_get_buf_type(struct nl_writer *nw, int size, int type, bool waitok)
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{
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MPASS(type + 1 <= sizeof(nlmsg_writers) / sizeof(nlmsg_writers[0]));
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NL_LOG(LOG_DEBUG3, "Setting up nw %p size %d type %d", nw, size, type);
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return (nlmsg_writers[type].init(nw, size, waitok));
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}
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static bool
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nlmsg_get_buf(struct nl_writer *nw, int size, bool waitok, bool is_linux)
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{
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int type;
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if (!is_linux) {
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if (__predict_true(size <= MCLBYTES))
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type = NS_WRITER_TYPE_MBUF;
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else
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type = NS_WRITER_TYPE_BUF;
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} else
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type = NS_WRITER_TYPE_LBUF;
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return (nlmsg_get_buf_type(nw, size, type, waitok));
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}
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bool
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_nlmsg_get_unicast_writer(struct nl_writer *nw, int size, struct nlpcb *nlp)
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{
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if (!nlmsg_get_buf(nw, size, false, nlp->nl_linux))
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return (false);
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nw->arg.ptr = (void *)nlp;
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nw->writer_target = NS_WRITER_TARGET_SOCKET;
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nlmsg_set_callback(nw);
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return (true);
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}
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bool
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_nlmsg_get_group_writer(struct nl_writer *nw, int size, int protocol, int group_id)
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{
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if (!nlmsg_get_buf(nw, size, false, false))
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return (false);
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nw->arg.group.proto = protocol;
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nw->arg.group.id = group_id;
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nw->writer_target = NS_WRITER_TARGET_GROUP;
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nlmsg_set_callback(nw);
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return (true);
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}
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bool
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_nlmsg_get_chain_writer(struct nl_writer *nw, int size, struct mbuf **pm)
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{
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if (!nlmsg_get_buf(nw, size, false, false))
|
|
return (false);
|
|
*pm = NULL;
|
|
nw->arg.ptr = (void *)pm;
|
|
nw->writer_target = NS_WRITER_TARGET_CHAIN;
|
|
nlmsg_set_callback(nw);
|
|
NL_LOG(LOG_DEBUG3, "setup cb %p (need %p)", nw->cb, &nlmsg_write_chain_mbuf);
|
|
return (true);
|
|
}
|
|
|
|
void
|
|
_nlmsg_ignore_limit(struct nl_writer *nw)
|
|
{
|
|
nw->ignore_limit = true;
|
|
}
|
|
|
|
bool
|
|
_nlmsg_flush(struct nl_writer *nw)
|
|
{
|
|
|
|
if (__predict_false(nw->hdr != NULL)) {
|
|
/* Last message has not been completed, skip it. */
|
|
int completed_len = (char *)nw->hdr - nw->data;
|
|
/* Send completed messages */
|
|
nw->offset -= nw->offset - completed_len;
|
|
nw->hdr = NULL;
|
|
}
|
|
|
|
NL_LOG(LOG_DEBUG2, "OUT");
|
|
bool result = nw->cb(nw, nw->_storage, nw->offset, nw->num_messages);
|
|
nw->_storage = NULL;
|
|
|
|
if (!result) {
|
|
NL_LOG(LOG_DEBUG, "nw %p offset %d: flush with %p() failed", nw, nw->offset, nw->cb);
|
|
}
|
|
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* Flushes previous data and allocates new underlying storage
|
|
* sufficient for holding at least @required_len bytes.
|
|
* Return true on success.
|
|
*/
|
|
bool
|
|
_nlmsg_refill_buffer(struct nl_writer *nw, int required_len)
|
|
{
|
|
struct nl_writer ns_new = {};
|
|
int completed_len, new_len;
|
|
|
|
if (nw->enomem)
|
|
return (false);
|
|
|
|
NL_LOG(LOG_DEBUG3, "no space at offset %d/%d (want %d), trying to reclaim",
|
|
nw->offset, nw->alloc_len, required_len);
|
|
|
|
/* Calculated new buffer size and allocate it s*/
|
|
completed_len = (nw->hdr != NULL) ? (char *)nw->hdr - nw->data : nw->offset;
|
|
if (completed_len > 0 && required_len < MCLBYTES) {
|
|
/* We already ran out of space, use the largest effective size */
|
|
new_len = max(nw->alloc_len, MCLBYTES);
|
|
} else {
|
|
if (nw->alloc_len < MCLBYTES)
|
|
new_len = MCLBYTES;
|
|
else
|
|
new_len = nw->alloc_len * 2;
|
|
while (new_len < required_len)
|
|
new_len *= 2;
|
|
}
|
|
bool waitok = (nw->malloc_flag == M_WAITOK);
|
|
bool is_linux = (nw->writer_type == NS_WRITER_TYPE_LBUF);
|
|
if (!nlmsg_get_buf(&ns_new, new_len, waitok, is_linux)) {
|
|
nw->enomem = true;
|
|
NL_LOG(LOG_DEBUG, "getting new buf failed, setting ENOMEM");
|
|
return (false);
|
|
}
|
|
if (nw->ignore_limit)
|
|
nlmsg_ignore_limit(&ns_new);
|
|
|
|
/* Update callback data */
|
|
ns_new.writer_target = nw->writer_target;
|
|
nlmsg_set_callback(&ns_new);
|
|
ns_new.arg = nw->arg;
|
|
|
|
/* Copy last (unfinished) header to the new storage */
|
|
int last_len = nw->offset - completed_len;
|
|
if (last_len > 0) {
|
|
memcpy(ns_new.data, nw->hdr, last_len);
|
|
ns_new.hdr = (struct nlmsghdr *)ns_new.data;
|
|
ns_new.offset = last_len;
|
|
}
|
|
|
|
NL_LOG(LOG_DEBUG2, "completed: %d bytes, copied: %d bytes", completed_len, last_len);
|
|
|
|
/* Flush completed headers & switch to the new nw */
|
|
nlmsg_flush(nw);
|
|
memcpy(nw, &ns_new, sizeof(struct nl_writer));
|
|
NL_LOG(LOG_DEBUG2, "switched buffer: used %d/%d bytes", nw->offset, nw->alloc_len);
|
|
|
|
return (true);
|
|
}
|
|
|
|
bool
|
|
_nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type,
|
|
uint16_t flags, uint32_t len)
|
|
{
|
|
struct nlmsghdr *hdr;
|
|
|
|
MPASS(nw->hdr == NULL);
|
|
|
|
int required_len = NETLINK_ALIGN(len + sizeof(struct nlmsghdr));
|
|
if (__predict_false(nw->offset + required_len > nw->alloc_len)) {
|
|
if (!nlmsg_refill_buffer(nw, required_len))
|
|
return (false);
|
|
}
|
|
|
|
hdr = (struct nlmsghdr *)(&nw->data[nw->offset]);
|
|
|
|
hdr->nlmsg_len = len;
|
|
hdr->nlmsg_type = type;
|
|
hdr->nlmsg_flags = flags;
|
|
hdr->nlmsg_seq = seq;
|
|
hdr->nlmsg_pid = portid;
|
|
|
|
nw->hdr = hdr;
|
|
nw->offset += sizeof(struct nlmsghdr);
|
|
|
|
return (true);
|
|
}
|
|
|
|
bool
|
|
_nlmsg_end(struct nl_writer *nw)
|
|
{
|
|
MPASS(nw->hdr != NULL);
|
|
|
|
if (nw->enomem) {
|
|
NL_LOG(LOG_DEBUG, "ENOMEM when dumping message");
|
|
nlmsg_abort(nw);
|
|
return (false);
|
|
}
|
|
|
|
nw->hdr->nlmsg_len = (uint32_t)(nw->data + nw->offset - (char *)nw->hdr);
|
|
NL_LOG(LOG_DEBUG2, "wrote msg len: %u type: %d: flags: 0x%X seq: %u pid: %u",
|
|
nw->hdr->nlmsg_len, nw->hdr->nlmsg_type, nw->hdr->nlmsg_flags,
|
|
nw->hdr->nlmsg_seq, nw->hdr->nlmsg_pid);
|
|
nw->hdr = NULL;
|
|
nw->num_messages++;
|
|
return (true);
|
|
}
|
|
|
|
void
|
|
_nlmsg_abort(struct nl_writer *nw)
|
|
{
|
|
if (nw->hdr != NULL) {
|
|
nw->offset = (uint32_t)((char *)nw->hdr - nw->data);
|
|
nw->hdr = NULL;
|
|
}
|
|
}
|
|
|
|
void
|
|
nlmsg_ack(struct nlpcb *nlp, int error, struct nlmsghdr *hdr,
|
|
struct nl_pstate *npt)
|
|
{
|
|
struct nlmsgerr *errmsg;
|
|
int payload_len;
|
|
uint32_t flags = nlp->nl_flags;
|
|
struct nl_writer *nw = npt->nw;
|
|
bool cap_ack;
|
|
|
|
payload_len = sizeof(struct nlmsgerr);
|
|
|
|
/*
|
|
* The only case when we send the full message in the
|
|
* reply is when there is an error and NETLINK_CAP_ACK
|
|
* is not set.
|
|
*/
|
|
cap_ack = (error == 0) || (flags & NLF_CAP_ACK);
|
|
if (!cap_ack)
|
|
payload_len += hdr->nlmsg_len - sizeof(struct nlmsghdr);
|
|
payload_len = NETLINK_ALIGN(payload_len);
|
|
|
|
uint16_t nl_flags = cap_ack ? NLM_F_CAPPED : 0;
|
|
if ((npt->err_msg || npt->err_off) && nlp->nl_flags & NLF_EXT_ACK)
|
|
nl_flags |= NLM_F_ACK_TLVS;
|
|
|
|
NL_LOG(LOG_DEBUG3, "acknowledging message type %d seq %d",
|
|
hdr->nlmsg_type, hdr->nlmsg_seq);
|
|
|
|
if (!nlmsg_add(nw, nlp->nl_port, hdr->nlmsg_seq, NLMSG_ERROR, nl_flags, payload_len))
|
|
goto enomem;
|
|
|
|
errmsg = nlmsg_reserve_data(nw, payload_len, struct nlmsgerr);
|
|
errmsg->error = error;
|
|
/* In case of error copy the whole message, else just the header */
|
|
memcpy(&errmsg->msg, hdr, cap_ack ? sizeof(*hdr) : hdr->nlmsg_len);
|
|
|
|
if (npt->err_msg != NULL && nlp->nl_flags & NLF_EXT_ACK)
|
|
nlattr_add_string(nw, NLMSGERR_ATTR_MSG, npt->err_msg);
|
|
if (npt->err_off != 0 && nlp->nl_flags & NLF_EXT_ACK)
|
|
nlattr_add_u32(nw, NLMSGERR_ATTR_OFFS, npt->err_off);
|
|
if (npt->cookie != NULL)
|
|
nlattr_add_raw(nw, npt->cookie);
|
|
|
|
if (nlmsg_end(nw))
|
|
return;
|
|
enomem:
|
|
NLP_LOG(LOG_DEBUG, nlp, "error allocating ack data for message %d seq %u",
|
|
hdr->nlmsg_type, hdr->nlmsg_seq);
|
|
nlmsg_abort(nw);
|
|
}
|
|
|
|
bool
|
|
_nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr)
|
|
{
|
|
if (!nlmsg_add(nw, hdr->nlmsg_pid, hdr->nlmsg_seq, NLMSG_DONE, 0, sizeof(int))) {
|
|
NL_LOG(LOG_DEBUG, "Error finalizing table dump");
|
|
return (false);
|
|
}
|
|
/* Save operation result */
|
|
int *perror = nlmsg_reserve_object(nw, int);
|
|
NL_LOG(LOG_DEBUG2, "record error=%d at off %d (%p)", error,
|
|
nw->offset, perror);
|
|
*perror = error;
|
|
nlmsg_end(nw);
|
|
nw->suppress_ack = true;
|
|
|
|
return (true);
|
|
}
|