diff --git a/sys/netlink/netlink_message_writer.c b/sys/netlink/netlink_message_writer.c index 0d27d5d0d47c..2187c40f2786 100644 --- a/sys/netlink/netlink_message_writer.c +++ b/sys/netlink/netlink_message_writer.c @@ -1,691 +1,690 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2022 Alexander V. Chernikov * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR OR CONTRIBUTORS 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 __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEBUG_MOD_NAME nl_writer #define DEBUG_MAX_LEVEL LOG_DEBUG3 #include _DECLARE_DEBUG(LOG_DEBUG); /* * The goal of this file is to provide convenient message writing KPI on top of * different storage methods (mbufs, uio, temporary memory chunks). * * The main KPI guarantee is the the (last) message always resides in the contiguous * memory buffer, so one is able to update the header after writing the entire message. * * This guarantee comes with a side effect of potentially reallocating underlying * buffer, so one needs to update the desired pointers after something is added * to the header. * * Messaging layer contains hooks performing transparent Linux translation for the messages. * * There are 3 types of supported targets: * * socket (adds mbufs to the socket buffer, used for message replies) * * group (sends mbuf/chain to the specified groups, used for the notifications) * * chain (returns mbuf chain, used in Linux message translation code) * * There are 3 types of storage: * * NS_WRITER_TYPE_MBUF (mbuf-based, most efficient, used when a single message * fits in MCLBYTES) * * NS_WRITER_TYPE_BUF (fallback, malloc-based, used when a single message needs * to be larger than one supported by NS_WRITER_TYPE_MBUF) * * NS_WRITER_TYPE_LBUF (malloc-based, similar to NS_WRITER_TYPE_BUF, used for * Linux sockets, calls translation hook prior to sending messages to the socket). * * Internally, KPI switches between different types of storage when memory requirements * change. It happens transparently to the caller. */ typedef bool nlwriter_op_init(struct nl_writer *nw, int size, bool waitok); typedef bool nlwriter_op_write(struct nl_writer *nw, void *buf, int buflen, int cnt); struct nlwriter_ops { nlwriter_op_init *init; nlwriter_op_write *write_socket; nlwriter_op_write *write_group; nlwriter_op_write *write_chain; }; /* * NS_WRITER_TYPE_BUF * Writes message to a temporary memory buffer, * flushing to the socket/group when buffer size limit is reached */ static bool nlmsg_get_ns_buf(struct nl_writer *nw, int size, bool waitok) { int mflag = waitok ? M_WAITOK : M_NOWAIT; nw->_storage = malloc(size, M_NETLINK, mflag | M_ZERO); if (__predict_false(nw->_storage == NULL)) return (false); nw->alloc_len = size; nw->offset = 0; nw->hdr = NULL; nw->data = nw->_storage; nw->writer_type = NS_WRITER_TYPE_BUF; nw->malloc_flag = mflag; nw->num_messages = 0; nw->enomem = false; return (true); } static bool nlmsg_write_socket_buf(struct nl_writer *nw, void *buf, int datalen, int cnt) { NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw); if (__predict_false(datalen == 0)) { free(buf, M_NETLINK); return (true); } struct mbuf *m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR); if (__predict_false(m == NULL)) { /* XXX: should we set sorcverr? */ free(buf, M_NETLINK); return (false); } m_append(m, datalen, buf); free(buf, M_NETLINK); int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0; - return (nl_send_one(m, (struct nlpcb *)(nw->arg_ptr), cnt, io_flags)); + return (nl_send_one(m, (struct nlpcb *)(nw->arg_ptr), cnt, io_flags)); } static bool nlmsg_write_group_buf(struct nl_writer *nw, void *buf, int datalen, int cnt) { NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr); if (__predict_false(datalen == 0)) { free(buf, M_NETLINK); return (true); } struct mbuf *m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR); if (__predict_false(m == NULL)) { free(buf, M_NETLINK); return (false); } bool success = m_append(m, datalen, buf) != 0; free(buf, M_NETLINK); if (!success) return (false); - nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF); + nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF); return (true); } static bool nlmsg_write_chain_buf(struct nl_writer *nw, void *buf, int datalen, int cnt) { struct mbuf **m0 = (struct mbuf **)(nw->arg_ptr); NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr); if (__predict_false(datalen == 0)) { free(buf, M_NETLINK); return (true); } if (*m0 == NULL) { struct mbuf *m; m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR); if (__predict_false(m == NULL)) { free(buf, M_NETLINK); return (false); } *m0 = m; } if (__predict_false(m_append(*m0, datalen, buf) == 0)) { free(buf, M_NETLINK); return (false); } - return (true); + return (true); } /* * NS_WRITER_TYPE_MBUF * Writes message to the allocated mbuf, * flushing to socket/group when mbuf size limit is reached. * This is the most efficient mechanism as it avoids double-copying. * * Allocates a single mbuf suitable to store up to @size bytes of data. * If size < MHLEN (around 160 bytes), allocates mbuf with pkghdr * If size <= MCLBYTES (2k), allocate a single mbuf cluster * Otherwise, return NULL. */ static bool nlmsg_get_ns_mbuf(struct nl_writer *nw, int size, bool waitok) { struct mbuf *m; int mflag = waitok ? M_WAITOK : M_NOWAIT; - m = m_get2(size, mflag, MT_DATA, M_PKTHDR); - if (__predict_false(m == NULL)) - return (false); - nw->alloc_len = M_TRAILINGSPACE(m); - nw->offset = 0; - nw->hdr = NULL; + m = m_get2(size, mflag, MT_DATA, M_PKTHDR); + if (__predict_false(m == NULL)) + return (false); + nw->alloc_len = M_TRAILINGSPACE(m); + nw->offset = 0; + nw->hdr = NULL; nw->_storage = (void *)m; nw->data = mtod(m, void *); nw->writer_type = NS_WRITER_TYPE_MBUF; nw->malloc_flag = mflag; nw->num_messages = 0; nw->enomem = false; memset(nw->data, 0, size); - NL_LOG(LOG_DEBUG2, "alloc mbuf %p req_len %d alloc_len %d data_ptr %p", - m, size, nw->alloc_len, nw->data); - return (true); + NL_LOG(LOG_DEBUG2, "alloc mbuf %p req_len %d alloc_len %d data_ptr %p", + m, size, nw->alloc_len, nw->data); + return (true); } static bool nlmsg_write_socket_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt) { struct mbuf *m = (struct mbuf *)buf; NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr); if (__predict_false(datalen == 0)) { m_freem(m); return (true); } m->m_pkthdr.len = datalen; m->m_len = datalen; int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0; - return (nl_send_one(m, (struct nlpcb *)(nw->arg_ptr), cnt, io_flags)); + return (nl_send_one(m, (struct nlpcb *)(nw->arg_ptr), cnt, io_flags)); } static bool nlmsg_write_group_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt) { struct mbuf *m = (struct mbuf *)buf; NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr); if (__predict_false(datalen == 0)) { m_freem(m); return (true); } m->m_pkthdr.len = datalen; m->m_len = datalen; - nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF); + nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF); return (true); } static bool nlmsg_write_chain_mbuf(struct nl_writer *nw, void *buf, int datalen, int cnt) { struct mbuf *m_new = (struct mbuf *)buf; struct mbuf **m0 = (struct mbuf **)(nw->arg_ptr); NL_LOG(LOG_DEBUG2, "IN: ptr: %p len: %d arg: %p", buf, datalen, nw->arg_ptr); if (__predict_false(datalen == 0)) { m_freem(m_new); return (true); } m_new->m_pkthdr.len = datalen; m_new->m_len = datalen; if (*m0 == NULL) { *m0 = m_new; } else { struct mbuf *m_last; for (m_last = *m0; m_last->m_next != NULL; m_last = m_last->m_next) ; m_last->m_next = m_new; (*m0)->m_pkthdr.len += datalen; } - return (true); + return (true); } /* * NS_WRITER_TYPE_LBUF * Writes message to the allocated memory buffer, * flushing to socket/group when mbuf size limit is reached. * Calls linux handler to rewrite messages before sending to the socket. */ static bool nlmsg_get_ns_lbuf(struct nl_writer *nw, int size, bool waitok) { int mflag = waitok ? M_WAITOK : M_NOWAIT; size = roundup2(size, sizeof(void *)); int add_size = sizeof(struct linear_buffer) + SCRATCH_BUFFER_SIZE; char *buf = malloc(add_size + size * 2, M_NETLINK, mflag | M_ZERO); if (__predict_false(buf == NULL)) return (false); /* Fill buffer header first */ struct linear_buffer *lb = (struct linear_buffer *)buf; lb->base = &buf[sizeof(struct linear_buffer) + size]; lb->size = size + SCRATCH_BUFFER_SIZE; nw->alloc_len = size; nw->offset = 0; nw->hdr = NULL; nw->_storage = buf; nw->data = (char *)(lb + 1); nw->malloc_flag = mflag; nw->writer_type = NS_WRITER_TYPE_LBUF; nw->num_messages = 0; nw->enomem = false; return (true); } - static bool nlmsg_write_socket_lbuf(struct nl_writer *nw, void *buf, int datalen, int cnt) { struct linear_buffer *lb = (struct linear_buffer *)buf; char *data = (char *)(lb + 1); struct nlpcb *nlp = (struct nlpcb *)(nw->arg_ptr); if (__predict_false(datalen == 0)) { free(buf, M_NETLINK); return (true); } struct mbuf *m = NULL; if (linux_netlink_p != NULL) m = linux_netlink_p->msgs_to_linux(nlp->nl_proto, data, datalen, nlp); free(buf, M_NETLINK); if (__predict_false(m == NULL)) { /* XXX: should we set sorcverr? */ return (false); } int io_flags = (nw->ignore_limit) ? NL_IOF_IGNORE_LIMIT : 0; - return (nl_send_one(m, nlp, cnt, io_flags)); + return (nl_send_one(m, nlp, cnt, io_flags)); } /* Shouldn't be called (maybe except Linux code originating message) */ static bool nlmsg_write_group_lbuf(struct nl_writer *nw, void *buf, int datalen, int cnt) { struct linear_buffer *lb = (struct linear_buffer *)buf; char *data = (char *)(lb + 1); if (__predict_false(datalen == 0)) { free(buf, M_NETLINK); return (true); } struct mbuf *m = m_getm2(NULL, datalen, nw->malloc_flag, MT_DATA, M_PKTHDR); if (__predict_false(m == NULL)) { free(buf, M_NETLINK); return (false); } m_append(m, datalen, data); free(buf, M_NETLINK); - nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF); + nl_send_group(m, cnt, nw->arg_uint >> 16, nw->arg_uint & 0xFFFF); return (true); } static const struct nlwriter_ops nlmsg_writers[] = { /* NS_WRITER_TYPE_MBUF */ { .init = nlmsg_get_ns_mbuf, .write_socket = nlmsg_write_socket_mbuf, .write_group = nlmsg_write_group_mbuf, .write_chain = nlmsg_write_chain_mbuf, }, /* NS_WRITER_TYPE_BUF */ { .init = nlmsg_get_ns_buf, .write_socket = nlmsg_write_socket_buf, .write_group = nlmsg_write_group_buf, .write_chain = nlmsg_write_chain_buf, }, /* NS_WRITER_TYPE_LBUF */ { .init = nlmsg_get_ns_lbuf, .write_socket = nlmsg_write_socket_lbuf, .write_group = nlmsg_write_group_lbuf, }, }; static void nlmsg_set_callback(struct nl_writer *nw) { const struct nlwriter_ops *pops = &nlmsg_writers[nw->writer_type]; switch (nw->writer_target) { case NS_WRITER_TARGET_SOCKET: nw->cb = pops->write_socket; break; case NS_WRITER_TARGET_GROUP: nw->cb = pops->write_group; break; case NS_WRITER_TARGET_CHAIN: nw->cb = pops->write_chain; break; default: panic("not implemented"); } } static bool nlmsg_get_buf_type(struct nl_writer *nw, int size, int type, bool waitok) { MPASS(type + 1 <= sizeof(nlmsg_writers) / sizeof(nlmsg_writers[0])); NL_LOG(LOG_DEBUG3, "Setting up nw %p size %d type %d", nw, size, type); return (nlmsg_writers[type].init(nw, size, waitok)); } static bool nlmsg_get_buf(struct nl_writer *nw, int size, bool waitok, bool is_linux) { int type; if (!is_linux) { if (__predict_true(size <= MCLBYTES)) type = NS_WRITER_TYPE_MBUF; else type = NS_WRITER_TYPE_BUF; } else type = NS_WRITER_TYPE_LBUF; return (nlmsg_get_buf_type(nw, size, type, waitok)); } bool nlmsg_get_unicast_writer(struct nl_writer *nw, int size, struct nlpcb *nlp) { - if (!nlmsg_get_buf(nw, size, false, nlp->nl_linux)) - return (false); - nw->arg_ptr = (void *)nlp; + if (!nlmsg_get_buf(nw, size, false, nlp->nl_linux)) + return (false); + nw->arg_ptr = (void *)nlp; nw->writer_target = NS_WRITER_TARGET_SOCKET; nlmsg_set_callback(nw); - return (true); + return (true); } bool nlmsg_get_group_writer(struct nl_writer *nw, int size, int protocol, int group_id) { - if (!nlmsg_get_buf(nw, size, false, false)) - return (false); - nw->arg_uint = (uint64_t)protocol << 16 | (uint64_t)group_id; + if (!nlmsg_get_buf(nw, size, false, false)) + return (false); + nw->arg_uint = (uint64_t)protocol << 16 | (uint64_t)group_id; nw->writer_target = NS_WRITER_TARGET_GROUP; nlmsg_set_callback(nw); - return (true); + return (true); } bool nlmsg_get_chain_writer(struct nl_writer *nw, int size, struct mbuf **pm) { - if (!nlmsg_get_buf(nw, size, false, false)) - return (false); + if (!nlmsg_get_buf(nw, size, false, false)) + return (false); *pm = NULL; - nw->arg_ptr = (void *)pm; + 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); + 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; + 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; + 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); - } + if (!result) { + NL_LOG(LOG_DEBUG, "nw %p offset %d: flush with %p() failed", nw, nw->offset, nw->cb); + } - return (result); + 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; + 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*/ + /* 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)) { + 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); + 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_uint = nw->arg_uint; - /* Copy last (unfinished) header to the new storage */ - int last_len = nw->offset - completed_len; + /* 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); + NL_LOG(LOG_DEBUG2, "completed: %d bytes, copied: %d bytes", completed_len, last_len); - /* Flush completed headers & switch to the new nw */ + /* 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); + NL_LOG(LOG_DEBUG2, "switched buffer: used %d/%d bytes", nw->offset, nw->alloc_len); - return (true); + 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 (__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 = (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; + 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); + nw->hdr = hdr; + nw->offset += sizeof(struct nlmsghdr); - return (true); + 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); + 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->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; - } + 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; /* * TODO: handle cookies */ 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 (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); }