/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2021 Ng Peng Nam Sean * Copyright (c) 2022 Alexander V. Chernikov * Copyright (c) 2023 Gleb Smirnoff * * 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. */ /* * This file contains socket and protocol bindings for netlink. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEBUG_MOD_NAME nl_domain #define DEBUG_MAX_LEVEL LOG_DEBUG3 #include _DECLARE_DEBUG(LOG_INFO); _Static_assert((NLP_MAX_GROUPS % 64) == 0, "NLP_MAX_GROUPS has to be multiple of 64"); _Static_assert(NLP_MAX_GROUPS >= 64, "NLP_MAX_GROUPS has to be at least 64"); #define NLCTL_TRACKER struct rm_priotracker nl_tracker #define NLCTL_RLOCK() rm_rlock(&V_nl_ctl.ctl_lock, &nl_tracker) #define NLCTL_RUNLOCK() rm_runlock(&V_nl_ctl.ctl_lock, &nl_tracker) #define NLCTL_LOCK_ASSERT() rm_assert(&V_nl_ctl.ctl_lock, RA_LOCKED) #define NLCTL_WLOCK() rm_wlock(&V_nl_ctl.ctl_lock) #define NLCTL_WUNLOCK() rm_wunlock(&V_nl_ctl.ctl_lock) #define NLCTL_WLOCK_ASSERT() rm_assert(&V_nl_ctl.ctl_lock, RA_WLOCKED) static u_long nl_sendspace = NLSNDQ; SYSCTL_ULONG(_net_netlink, OID_AUTO, sendspace, CTLFLAG_RW, &nl_sendspace, 0, "Default netlink socket send space"); static u_long nl_recvspace = NLSNDQ; SYSCTL_ULONG(_net_netlink, OID_AUTO, recvspace, CTLFLAG_RW, &nl_recvspace, 0, "Default netlink socket receive space"); extern u_long sb_max_adj; static u_long nl_maxsockbuf = 512 * 1024 * 1024; /* 512M, XXX: init based on physmem */ static int sysctl_handle_nl_maxsockbuf(SYSCTL_HANDLER_ARGS); SYSCTL_OID(_net_netlink, OID_AUTO, nl_maxsockbuf, CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_MPSAFE, &nl_maxsockbuf, 0, sysctl_handle_nl_maxsockbuf, "LU", "Maximum Netlink socket buffer size"); static unsigned int osd_slot_id = 0; void nl_osd_register(void) { osd_slot_id = osd_register(OSD_THREAD, NULL, NULL); } void nl_osd_unregister(void) { osd_deregister(OSD_THREAD, osd_slot_id); } struct nlpcb * _nl_get_thread_nlp(struct thread *td) { return (osd_get(OSD_THREAD, &td->td_osd, osd_slot_id)); } void nl_set_thread_nlp(struct thread *td, struct nlpcb *nlp) { NLP_LOG(LOG_DEBUG2, nlp, "Set thread %p nlp to %p (slot %u)", td, nlp, osd_slot_id); if (osd_set(OSD_THREAD, &td->td_osd, osd_slot_id, nlp) == 0) return; /* Failed, need to realloc */ void **rsv = osd_reserve(osd_slot_id); osd_set_reserved(OSD_THREAD, &td->td_osd, osd_slot_id, rsv, nlp); } /* * Looks up a nlpcb struct based on the @portid. Need to claim nlsock_mtx. * Returns nlpcb pointer if present else NULL */ static struct nlpcb * nl_port_lookup(uint32_t port_id) { struct nlpcb *nlp; CK_LIST_FOREACH(nlp, &V_nl_ctl.ctl_port_head, nl_port_next) { if (nlp->nl_port == port_id) return (nlp); } return (NULL); } static void nlp_join_group(struct nlpcb *nlp, unsigned int group_id) { MPASS(group_id < NLP_MAX_GROUPS); NLCTL_WLOCK_ASSERT(); /* TODO: add family handler callback */ if (!nlp_unconstrained_vnet(nlp)) return; BIT_SET(NLP_MAX_GROUPS, group_id, &nlp->nl_groups); } static void nlp_leave_group(struct nlpcb *nlp, unsigned int group_id) { MPASS(group_id < NLP_MAX_GROUPS); NLCTL_WLOCK_ASSERT(); BIT_CLR(NLP_MAX_GROUPS, group_id, &nlp->nl_groups); } static bool nlp_memberof_group(struct nlpcb *nlp, unsigned int group_id) { MPASS(group_id < NLP_MAX_GROUPS); NLCTL_LOCK_ASSERT(); return (BIT_ISSET(NLP_MAX_GROUPS, group_id, &nlp->nl_groups)); } static uint32_t nlp_get_groups_compat(struct nlpcb *nlp) { uint32_t groups_mask = 0; NLCTL_LOCK_ASSERT(); for (int i = 0; i < 32; i++) { if (nlp_memberof_group(nlp, i + 1)) groups_mask |= (1 << i); } return (groups_mask); } static struct nl_buf * nl_buf_copy(struct nl_buf *nb) { struct nl_buf *copy; copy = nl_buf_alloc(nb->buflen, M_NOWAIT); if (__predict_false(copy == NULL)) return (NULL); memcpy(copy, nb, sizeof(*nb) + nb->buflen); return (copy); } /* * Broadcasts in the writer's buffer. */ bool nl_send_group(struct nl_writer *nw) { struct nl_buf *nb = nw->buf; struct nlpcb *nlp_last = NULL; struct nlpcb *nlp; NLCTL_TRACKER; IF_DEBUG_LEVEL(LOG_DEBUG2) { struct nlmsghdr *hdr = (struct nlmsghdr *)nb->data; NL_LOG(LOG_DEBUG2, "MCAST len %u msg type %d len %u to group %d/%d", nb->datalen, hdr->nlmsg_type, hdr->nlmsg_len, nw->group.proto, nw->group.id); } nw->buf = NULL; NLCTL_RLOCK(); CK_LIST_FOREACH(nlp, &V_nl_ctl.ctl_pcb_head, nl_next) { if ((nw->group.priv == 0 || priv_check_cred( nlp->nl_socket->so_cred, nw->group.priv) == 0) && nlp->nl_proto == nw->group.proto && nlp_memberof_group(nlp, nw->group.id)) { if (nlp_last != NULL) { struct nl_buf *copy; copy = nl_buf_copy(nb); if (copy != NULL) { nw->buf = copy; (void)nl_send(nw, nlp_last); } else { NLP_LOCK(nlp_last); if (nlp_last->nl_socket != NULL) sorwakeup(nlp_last->nl_socket); NLP_UNLOCK(nlp_last); } } nlp_last = nlp; } } if (nlp_last != NULL) { nw->buf = nb; (void)nl_send(nw, nlp_last); } else nl_buf_free(nb); NLCTL_RUNLOCK(); return (true); } void nl_clear_group(u_int group) { struct nlpcb *nlp; NLCTL_WLOCK(); CK_LIST_FOREACH(nlp, &V_nl_ctl.ctl_pcb_head, nl_next) if (nlp_memberof_group(nlp, group)) nlp_leave_group(nlp, group); NLCTL_WUNLOCK(); } static uint32_t nl_find_port(void) { /* * app can open multiple netlink sockets. * Start with current pid, if already taken, * try random numbers in 65k..256k+65k space, * avoiding clash with pids. */ if (nl_port_lookup(curproc->p_pid) == NULL) return (curproc->p_pid); for (int i = 0; i < 16; i++) { uint32_t nl_port = (arc4random() % 65536) + 65536 * 4; if (nl_port_lookup(nl_port) == 0) return (nl_port); NL_LOG(LOG_DEBUG3, "tried %u\n", nl_port); } return (curproc->p_pid); } static int nl_bind_locked(struct nlpcb *nlp, struct sockaddr_nl *snl) { if (nlp->nl_bound) { if (nlp->nl_port != snl->nl_pid) { NL_LOG(LOG_DEBUG, "bind() failed: program pid %d " "is different from provided pid %d", nlp->nl_port, snl->nl_pid); return (EINVAL); // XXX: better error } } else { if (snl->nl_pid == 0) snl->nl_pid = nl_find_port(); if (nl_port_lookup(snl->nl_pid) != NULL) return (EADDRINUSE); nlp->nl_port = snl->nl_pid; nlp->nl_bound = true; CK_LIST_INSERT_HEAD(&V_nl_ctl.ctl_port_head, nlp, nl_port_next); } for (int i = 0; i < 32; i++) { if (snl->nl_groups & ((uint32_t)1 << i)) nlp_join_group(nlp, i + 1); else nlp_leave_group(nlp, i + 1); } return (0); } static int nl_attach(struct socket *so, int proto, struct thread *td) { struct nlpcb *nlp; int error; if (__predict_false(netlink_unloading != 0)) return (EAFNOSUPPORT); error = nl_verify_proto(proto); if (error != 0) return (error); bool is_linux = SV_PROC_ABI(td->td_proc) == SV_ABI_LINUX; NL_LOG(LOG_DEBUG2, "socket %p, %sPID %d: attaching socket to %s", so, is_linux ? "(linux) " : "", curproc->p_pid, nl_get_proto_name(proto)); nlp = malloc(sizeof(struct nlpcb), M_PCB, M_WAITOK | M_ZERO); error = soreserve(so, nl_sendspace, nl_recvspace); if (error != 0) { free(nlp, M_PCB); return (error); } TAILQ_INIT(&so->so_rcv.nl_queue); TAILQ_INIT(&so->so_snd.nl_queue); so->so_pcb = nlp; nlp->nl_socket = so; nlp->nl_proto = proto; nlp->nl_process_id = curproc->p_pid; nlp->nl_linux = is_linux; nlp->nl_unconstrained_vnet = !jailed_without_vnet(so->so_cred); nlp->nl_need_thread_setup = true; NLP_LOCK_INIT(nlp); refcount_init(&nlp->nl_refcount, 1); nlp->nl_taskqueue = taskqueue_create("netlink_socket", M_WAITOK, taskqueue_thread_enqueue, &nlp->nl_taskqueue); TASK_INIT(&nlp->nl_task, 0, nl_taskqueue_handler, nlp); taskqueue_start_threads(&nlp->nl_taskqueue, 1, PWAIT, "netlink_socket (PID %u)", nlp->nl_process_id); NLCTL_WLOCK(); CK_LIST_INSERT_HEAD(&V_nl_ctl.ctl_pcb_head, nlp, nl_next); NLCTL_WUNLOCK(); soisconnected(so); return (0); } static int nl_bind(struct socket *so, struct sockaddr *sa, struct thread *td) { struct nlpcb *nlp = sotonlpcb(so); struct sockaddr_nl *snl = (struct sockaddr_nl *)sa; int error; NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid); if (snl->nl_len != sizeof(*snl)) { NL_LOG(LOG_DEBUG, "socket %p, wrong sizeof(), ignoring bind()", so); return (EINVAL); } NLCTL_WLOCK(); NLP_LOCK(nlp); error = nl_bind_locked(nlp, snl); NLP_UNLOCK(nlp); NLCTL_WUNLOCK(); NL_LOG(LOG_DEBUG2, "socket %p, bind() to %u, groups %u, error %d", so, snl->nl_pid, snl->nl_groups, error); return (error); } static int nl_assign_port(struct nlpcb *nlp, uint32_t port_id) { struct sockaddr_nl snl = { .nl_pid = port_id, }; int error; NLCTL_WLOCK(); NLP_LOCK(nlp); snl.nl_groups = nlp_get_groups_compat(nlp); error = nl_bind_locked(nlp, &snl); NLP_UNLOCK(nlp); NLCTL_WUNLOCK(); NL_LOG(LOG_DEBUG3, "socket %p, port assign: %d, error: %d", nlp->nl_socket, port_id, error); return (error); } /* * nl_autobind_port binds a unused portid to @nlp * @nlp: pcb data for the netlink socket * @candidate_id: first id to consider */ static int nl_autobind_port(struct nlpcb *nlp, uint32_t candidate_id) { uint32_t port_id = candidate_id; NLCTL_TRACKER; bool exist; int error = EADDRINUSE; for (int i = 0; i < 10; i++) { NL_LOG(LOG_DEBUG3, "socket %p, trying to assign port %d", nlp->nl_socket, port_id); NLCTL_RLOCK(); exist = nl_port_lookup(port_id) != 0; NLCTL_RUNLOCK(); if (!exist) { error = nl_assign_port(nlp, port_id); if (error != EADDRINUSE) break; } port_id++; } NL_LOG(LOG_DEBUG3, "socket %p, autobind to %d, error: %d", nlp->nl_socket, port_id, error); return (error); } static int nl_connect(struct socket *so, struct sockaddr *sa, struct thread *td) { struct sockaddr_nl *snl = (struct sockaddr_nl *)sa; struct nlpcb *nlp; NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid); if (snl->nl_len != sizeof(*snl)) { NL_LOG(LOG_DEBUG, "socket %p, wrong sizeof(), ignoring bind()", so); return (EINVAL); } nlp = sotonlpcb(so); if (!nlp->nl_bound) { int error = nl_autobind_port(nlp, td->td_proc->p_pid); if (error != 0) { NL_LOG(LOG_DEBUG, "socket %p, nl_autobind() failed: %d", so, error); return (error); } } /* XXX: Handle socket flags & multicast */ soisconnected(so); NL_LOG(LOG_DEBUG2, "socket %p, connect to %u", so, snl->nl_pid); return (0); } static void destroy_nlpcb_epoch(epoch_context_t ctx) { struct nlpcb *nlp; nlp = __containerof(ctx, struct nlpcb, nl_epoch_ctx); NLP_LOCK_DESTROY(nlp); free(nlp, M_PCB); } static void nl_close(struct socket *so) { MPASS(sotonlpcb(so) != NULL); struct nlpcb *nlp; struct nl_buf *nb; NL_LOG(LOG_DEBUG2, "detaching socket %p, PID %d", so, curproc->p_pid); nlp = sotonlpcb(so); /* Mark as inactive so no new work can be enqueued */ NLP_LOCK(nlp); bool was_bound = nlp->nl_bound; NLP_UNLOCK(nlp); /* Wait till all scheduled work has been completed */ taskqueue_drain_all(nlp->nl_taskqueue); taskqueue_free(nlp->nl_taskqueue); NLCTL_WLOCK(); NLP_LOCK(nlp); if (was_bound) { CK_LIST_REMOVE(nlp, nl_port_next); NL_LOG(LOG_DEBUG3, "socket %p, unlinking bound pid %u", so, nlp->nl_port); } CK_LIST_REMOVE(nlp, nl_next); nlp->nl_socket = NULL; NLP_UNLOCK(nlp); NLCTL_WUNLOCK(); so->so_pcb = NULL; while ((nb = TAILQ_FIRST(&so->so_snd.nl_queue)) != NULL) { TAILQ_REMOVE(&so->so_snd.nl_queue, nb, tailq); nl_buf_free(nb); } while ((nb = TAILQ_FIRST(&so->so_rcv.nl_queue)) != NULL) { TAILQ_REMOVE(&so->so_rcv.nl_queue, nb, tailq); nl_buf_free(nb); } NL_LOG(LOG_DEBUG3, "socket %p, detached", so); /* XXX: is delayed free needed? */ NET_EPOCH_CALL(destroy_nlpcb_epoch, &nlp->nl_epoch_ctx); } static int nl_disconnect(struct socket *so) { NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid); MPASS(sotonlpcb(so) != NULL); return (ENOTCONN); } static int nl_sockaddr(struct socket *so, struct sockaddr *sa) { *(struct sockaddr_nl *)sa = (struct sockaddr_nl ){ /* TODO: set other fields */ .nl_len = sizeof(struct sockaddr_nl), .nl_family = AF_NETLINK, .nl_pid = sotonlpcb(so)->nl_port, }; return (0); } static int nl_sosend(struct socket *so, struct sockaddr *addr, struct uio *uio, struct mbuf *m, struct mbuf *control, int flags, struct thread *td) { struct nlpcb *nlp = sotonlpcb(so); struct sockbuf *sb = &so->so_snd; struct nl_buf *nb; size_t len; int error; MPASS(m == NULL && uio != NULL); if (__predict_false(control != NULL)) { m_freem(control); return (EINVAL); } if (__predict_false(flags & MSG_OOB)) /* XXXGL: or just ignore? */ return (EOPNOTSUPP); if (__predict_false(uio->uio_resid < sizeof(struct nlmsghdr))) return (ENOBUFS); /* XXXGL: any better error? */ if (__predict_false(uio->uio_resid > sb->sb_hiwat)) return (EMSGSIZE); error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags)); if (error) return (error); len = roundup2(uio->uio_resid, 8) + SCRATCH_BUFFER_SIZE; if (nlp->nl_linux) len += roundup2(uio->uio_resid, 8); nb = nl_buf_alloc(len, M_WAITOK); nb->datalen = uio->uio_resid; error = uiomove(&nb->data[0], uio->uio_resid, uio); if (__predict_false(error)) goto out; NL_LOG(LOG_DEBUG2, "sending message to kernel %u bytes", nb->datalen); SOCK_SENDBUF_LOCK(so); restart: if (sb->sb_hiwat - sb->sb_ccc >= nb->datalen) { TAILQ_INSERT_TAIL(&sb->nl_queue, nb, tailq); sb->sb_acc += nb->datalen; sb->sb_ccc += nb->datalen; nb = NULL; } else if ((so->so_state & SS_NBIO) || (flags & (MSG_NBIO | MSG_DONTWAIT)) != 0) { SOCK_SENDBUF_UNLOCK(so); error = EWOULDBLOCK; goto out; } else { if ((error = sbwait(so, SO_SND)) != 0) { SOCK_SENDBUF_UNLOCK(so); goto out; } else goto restart; } SOCK_SENDBUF_UNLOCK(so); if (nb == NULL) { NL_LOG(LOG_DEBUG3, "success"); NLP_LOCK(nlp); nl_schedule_taskqueue(nlp); NLP_UNLOCK(nlp); } out: SOCK_IO_SEND_UNLOCK(so); if (nb != NULL) { NL_LOG(LOG_DEBUG3, "failure, error %d", error); nl_buf_free(nb); } return (error); } /* Create control data for recvmsg(2) on Netlink socket. */ static struct mbuf * nl_createcontrol(struct nlpcb *nlp) { struct { struct nlattr nla; uint32_t val; } data[] = { { .nla.nla_len = sizeof(struct nlattr) + sizeof(uint32_t), .nla.nla_type = NLMSGINFO_ATTR_PROCESS_ID, .val = nlp->nl_process_id, }, { .nla.nla_len = sizeof(struct nlattr) + sizeof(uint32_t), .nla.nla_type = NLMSGINFO_ATTR_PORT_ID, .val = nlp->nl_port, }, }; return (sbcreatecontrol(data, sizeof(data), NETLINK_MSG_INFO, SOL_NETLINK, M_WAITOK)); } static int nl_soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio, struct mbuf **mp, struct mbuf **controlp, int *flagsp) { static const struct sockaddr_nl nl_empty_src = { .nl_len = sizeof(struct sockaddr_nl), .nl_family = PF_NETLINK, .nl_pid = 0 /* comes from the kernel */ }; struct sockbuf *sb = &so->so_rcv; struct nlpcb *nlp = sotonlpcb(so); struct nl_buf *first, *last, *nb, *next; struct nlmsghdr *hdr; int flags, error; u_int len, overflow, partoff, partlen, msgrcv, datalen; bool nonblock, trunc, peek; MPASS(mp == NULL && uio != NULL); NL_LOG(LOG_DEBUG3, "socket %p, PID %d", so, curproc->p_pid); if (psa != NULL) *psa = sodupsockaddr((const struct sockaddr *)&nl_empty_src, M_WAITOK); if (controlp != NULL && (nlp->nl_flags & NLF_MSG_INFO)) *controlp = nl_createcontrol(nlp); flags = flagsp != NULL ? *flagsp & ~MSG_TRUNC : 0; trunc = flagsp != NULL ? *flagsp & MSG_TRUNC : false; nonblock = (so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT | MSG_NBIO)); peek = flags & MSG_PEEK; error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags)); if (__predict_false(error)) return (error); len = 0; overflow = 0; msgrcv = 0; datalen = 0; SOCK_RECVBUF_LOCK(so); while ((first = TAILQ_FIRST(&sb->nl_queue)) == NULL) { if (nonblock) { SOCK_RECVBUF_UNLOCK(so); SOCK_IO_RECV_UNLOCK(so); return (EWOULDBLOCK); } error = sbwait(so, SO_RCV); if (error) { SOCK_RECVBUF_UNLOCK(so); SOCK_IO_RECV_UNLOCK(so); return (error); } } /* * Netlink socket buffer consists of a queue of nl_bufs, but for the * userland there should be no boundaries. However, there are Netlink * messages, that shouldn't be split. Internal invariant is that a * message never spans two nl_bufs. * If a large userland buffer is provided, we would traverse the queue * until either queue end is reached or the buffer is fulfilled. If * an application provides a buffer that isn't able to fit a single * message, we would truncate it and lose its tail. This is the only * condition where we would lose data. If buffer is able to fit at * least one message, we would return it and won't truncate the next. * * We use same code for normal and MSG_PEEK case. At first queue pass * we scan nl_bufs and count lenght. In case we can read entire buffer * at one write everything is trivial. In case we can not, we save * pointer to the last (or partial) nl_buf and in the !peek case we * split the queue into two pieces. We can safely drop the queue lock, * as kernel would only append nl_bufs to the end of the queue, and * we are the exclusive owner of queue beginning due to sleepable lock. * At the second pass we copy data out and in !peek case free nl_bufs. */ TAILQ_FOREACH(nb, &sb->nl_queue, tailq) { u_int offset; MPASS(nb->offset < nb->datalen); offset = nb->offset; while (offset < nb->datalen) { hdr = (struct nlmsghdr *)&nb->data[offset]; MPASS(nb->offset + hdr->nlmsg_len <= nb->datalen); if (uio->uio_resid < len + hdr->nlmsg_len) { overflow = len + hdr->nlmsg_len - uio->uio_resid; partoff = nb->offset; if (offset > partoff) { partlen = offset - partoff; if (!peek) { nb->offset = offset; datalen += partlen; } } else if (len == 0 && uio->uio_resid > 0) { flags |= MSG_TRUNC; partlen = uio->uio_resid; if (peek) goto nospace; datalen += hdr->nlmsg_len; if (nb->offset + hdr->nlmsg_len == nb->datalen) { /* * Avoid leaving empty nb. * Process last nb normally. * Trust uiomove() to care * about negative uio_resid. */ nb = TAILQ_NEXT(nb, tailq); overflow = 0; partlen = 0; } else nb->offset += hdr->nlmsg_len; msgrcv++; } else partlen = 0; goto nospace; } len += hdr->nlmsg_len; offset += hdr->nlmsg_len; MPASS(offset <= nb->buflen); msgrcv++; } MPASS(offset == nb->datalen); datalen += nb->datalen - nb->offset; } nospace: last = nb; if (!peek) { if (last == NULL) TAILQ_INIT(&sb->nl_queue); else { /* XXXGL: create TAILQ_SPLIT */ TAILQ_FIRST(&sb->nl_queue) = last; last->tailq.tqe_prev = &TAILQ_FIRST(&sb->nl_queue); } MPASS(sb->sb_acc >= datalen); sb->sb_acc -= datalen; sb->sb_ccc -= datalen; } SOCK_RECVBUF_UNLOCK(so); for (nb = first; nb != last; nb = next) { next = TAILQ_NEXT(nb, tailq); if (__predict_true(error == 0)) error = uiomove(&nb->data[nb->offset], (int)(nb->datalen - nb->offset), uio); if (!peek) nl_buf_free(nb); } if (last != NULL && partlen > 0 && __predict_true(error == 0)) error = uiomove(&nb->data[partoff], (int)partlen, uio); if (trunc && overflow > 0) { uio->uio_resid -= overflow; MPASS(uio->uio_resid < 0); } else MPASS(uio->uio_resid >= 0); if (uio->uio_td) uio->uio_td->td_ru.ru_msgrcv += msgrcv; if (flagsp != NULL) *flagsp |= flags; SOCK_IO_RECV_UNLOCK(so); nl_on_transmit(sotonlpcb(so)); return (error); } static int nl_getoptflag(int sopt_name) { switch (sopt_name) { case NETLINK_CAP_ACK: return (NLF_CAP_ACK); case NETLINK_EXT_ACK: return (NLF_EXT_ACK); case NETLINK_GET_STRICT_CHK: return (NLF_STRICT); case NETLINK_MSG_INFO: return (NLF_MSG_INFO); } return (0); } static int nl_ctloutput(struct socket *so, struct sockopt *sopt) { struct nlpcb *nlp = sotonlpcb(so); uint32_t flag; int optval, error = 0; NLCTL_TRACKER; NL_LOG(LOG_DEBUG2, "%ssockopt(%p, %d)", (sopt->sopt_dir) ? "set" : "get", so, sopt->sopt_name); switch (sopt->sopt_dir) { case SOPT_SET: switch (sopt->sopt_name) { case NETLINK_ADD_MEMBERSHIP: case NETLINK_DROP_MEMBERSHIP: error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval)); if (error != 0) break; if (optval <= 0 || optval >= NLP_MAX_GROUPS) { error = ERANGE; break; } NL_LOG(LOG_DEBUG2, "ADD/DEL group %d", (uint32_t)optval); NLCTL_WLOCK(); if (sopt->sopt_name == NETLINK_ADD_MEMBERSHIP) nlp_join_group(nlp, optval); else nlp_leave_group(nlp, optval); NLCTL_WUNLOCK(); break; case NETLINK_CAP_ACK: case NETLINK_EXT_ACK: case NETLINK_GET_STRICT_CHK: case NETLINK_MSG_INFO: error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval)); if (error != 0) break; flag = nl_getoptflag(sopt->sopt_name); if ((flag == NLF_MSG_INFO) && nlp->nl_linux) { error = EINVAL; break; } NLCTL_WLOCK(); if (optval != 0) nlp->nl_flags |= flag; else nlp->nl_flags &= ~flag; NLCTL_WUNLOCK(); break; default: error = ENOPROTOOPT; } break; case SOPT_GET: switch (sopt->sopt_name) { case NETLINK_LIST_MEMBERSHIPS: NLCTL_RLOCK(); optval = nlp_get_groups_compat(nlp); NLCTL_RUNLOCK(); error = sooptcopyout(sopt, &optval, sizeof(optval)); break; case NETLINK_CAP_ACK: case NETLINK_EXT_ACK: case NETLINK_GET_STRICT_CHK: case NETLINK_MSG_INFO: NLCTL_RLOCK(); optval = (nlp->nl_flags & nl_getoptflag(sopt->sopt_name)) != 0; NLCTL_RUNLOCK(); error = sooptcopyout(sopt, &optval, sizeof(optval)); break; default: error = ENOPROTOOPT; } break; default: error = ENOPROTOOPT; } return (error); } static int sysctl_handle_nl_maxsockbuf(SYSCTL_HANDLER_ARGS) { int error = 0; u_long tmp_maxsockbuf = nl_maxsockbuf; error = sysctl_handle_long(oidp, &tmp_maxsockbuf, arg2, req); if (error || !req->newptr) return (error); if (tmp_maxsockbuf < MSIZE + MCLBYTES) return (EINVAL); nl_maxsockbuf = tmp_maxsockbuf; return (0); } static int nl_setsbopt(struct socket *so, struct sockopt *sopt) { int error, optval; bool result; if (sopt->sopt_name != SO_RCVBUF) return (sbsetopt(so, sopt)); /* Allow to override max buffer size in certain conditions */ error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error != 0) return (error); NL_LOG(LOG_DEBUG2, "socket %p, PID %d, SO_RCVBUF=%d", so, curproc->p_pid, optval); if (optval > sb_max_adj) { if (priv_check(curthread, PRIV_NET_ROUTE) != 0) return (EPERM); } SOCK_RECVBUF_LOCK(so); result = sbreserve_locked_limit(so, SO_RCV, optval, nl_maxsockbuf, curthread); SOCK_RECVBUF_UNLOCK(so); return (result ? 0 : ENOBUFS); } #define NETLINK_PROTOSW \ .pr_flags = PR_ATOMIC | PR_ADDR | PR_SOCKBUF, \ .pr_ctloutput = nl_ctloutput, \ .pr_setsbopt = nl_setsbopt, \ .pr_attach = nl_attach, \ .pr_bind = nl_bind, \ .pr_connect = nl_connect, \ .pr_disconnect = nl_disconnect, \ .pr_sosend = nl_sosend, \ .pr_soreceive = nl_soreceive, \ .pr_sockaddr = nl_sockaddr, \ .pr_close = nl_close static struct protosw netlink_raw_sw = { .pr_type = SOCK_RAW, NETLINK_PROTOSW }; static struct protosw netlink_dgram_sw = { .pr_type = SOCK_DGRAM, NETLINK_PROTOSW }; static struct domain netlinkdomain = { .dom_family = PF_NETLINK, .dom_name = "netlink", .dom_flags = DOMF_UNLOADABLE, .dom_nprotosw = 2, .dom_protosw = { &netlink_raw_sw, &netlink_dgram_sw }, }; DOMAIN_SET(netlink);