diff options
Diffstat (limited to 'nhrp/sysdep_netlink.c')
| -rw-r--r-- | nhrp/sysdep_netlink.c | 1159 |
1 files changed, 1159 insertions, 0 deletions
diff --git a/nhrp/sysdep_netlink.c b/nhrp/sysdep_netlink.c new file mode 100644 index 0000000..d058a98 --- /dev/null +++ b/nhrp/sysdep_netlink.c @@ -0,0 +1,1159 @@ +/* sysdep_netlink.c - Linux netlink glue + * + * Copyright (C) 2007-2009 Timo Teräs <timo.teras@iki.fi> + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 or later as + * published by the Free Software Foundation. + * + * See http://www.gnu.org/ for details. + */ + +#include <time.h> +#include <stdio.h> +#include <fcntl.h> +#include <errno.h> +#include <unistd.h> +#include <stdlib.h> +#include <malloc.h> +#include <string.h> +#include <sys/uio.h> +#include <sys/wait.h> +#include <sys/types.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <asm/types.h> +#include <arpa/inet.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <linux/ip.h> +#include <linux/if_arp.h> +#include <linux/if_tunnel.h> + +#include "libev.h" +#include "nhrp_common.h" +#include "nhrp_interface.h" +#include "nhrp_peer.h" + +#define NETLINK_KERNEL_BUFFER (256 * 1024) +#define NETLINK_RECV_BUFFER (8 * 1024) + +#define NLMSG_TAIL(nmsg) \ + ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len))) + +#define NDA_RTA(r) ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg)))) +#define NDA_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct ndmsg)) + +typedef void (*netlink_dispatch_f)(struct nlmsghdr *msg); + +struct netlink_fd { + int fd; + __u32 seq; + struct ev_io io; + + int dispatch_size; + const netlink_dispatch_f *dispatch; +}; + +static const int netlink_groups[] = { + 0, + RTMGRP_NEIGH, + RTMGRP_LINK, + RTMGRP_IPV4_IFADDR, + RTMGRP_IPV4_ROUTE, +}; +static struct netlink_fd netlink_fds[ARRAY_SIZE(netlink_groups)]; +#define talk_fd netlink_fds[0] + +static struct ev_io packet_io; + +static u_int16_t translate_mtu(u_int16_t mtu) +{ + /* if mtu is ethernet standard, do not advertise it + * pmtu should be working */ + if (mtu == 1500) + return 0; + return mtu; +} + +static void netlink_parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len) +{ + memset(tb, 0, sizeof(struct rtattr *) * (max + 1)); + while (RTA_OK(rta, len)) { + if (rta->rta_type <= max) + tb[rta->rta_type] = rta; + rta = RTA_NEXT(rta,len); + } +} + +static int netlink_add_rtattr_l(struct nlmsghdr *n, int maxlen, int type, + const void *data, int alen) +{ + int len = RTA_LENGTH(alen); + struct rtattr *rta; + + if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) + return FALSE; + + rta = NLMSG_TAIL(n); + rta->rta_type = type; + rta->rta_len = len; + memcpy(RTA_DATA(rta), data, alen); +#ifdef VALGRIND + /* Clear the padding area to avoid spurious warnings */ + memset(RTA_DATA(rta) + alen, 0, RTA_ALIGN(len) - alen); +#endif + n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len); + return TRUE; +} + +static int netlink_receive(struct netlink_fd *fd, struct nlmsghdr *reply) +{ + struct sockaddr_nl nladdr; + struct iovec iov; + struct msghdr msg = { + .msg_name = &nladdr, + .msg_namelen = sizeof(nladdr), + .msg_iov = &iov, + .msg_iovlen = 1, + }; + int got_reply = FALSE, len; + char buf[NETLINK_RECV_BUFFER]; + + iov.iov_base = buf; + while (!got_reply) { + int status; + struct nlmsghdr *h; + + iov.iov_len = sizeof(buf); + status = recvmsg(fd->fd, &msg, MSG_DONTWAIT); + if (status < 0) { + if (errno == EINTR) + continue; + if (errno == EAGAIN) + return reply == NULL; + nhrp_perror("Netlink overrun"); + continue; + } + + if (status == 0) { + nhrp_error("Netlink returned EOF"); + return FALSE; + } + + h = (struct nlmsghdr *) buf; + while (NLMSG_OK(h, status)) { + if (reply != NULL && + h->nlmsg_seq == reply->nlmsg_seq) { + len = h->nlmsg_len; + if (len > reply->nlmsg_len) { + nhrp_error("Netlink message truncated"); + len = reply->nlmsg_len; + } + memcpy(reply, h, len); + got_reply = TRUE; + } else if (h->nlmsg_type <= fd->dispatch_size && + fd->dispatch[h->nlmsg_type] != NULL) { + fd->dispatch[h->nlmsg_type](h); + } else if (h->nlmsg_type != NLMSG_DONE) { + nhrp_info("Unknown NLmsg: 0x%08x, len %d", + h->nlmsg_type, h->nlmsg_len); + } + h = NLMSG_NEXT(h, status); + } + } + + return TRUE; +} + +static int netlink_send(struct netlink_fd *fd, struct nlmsghdr *req) +{ + struct sockaddr_nl nladdr; + struct iovec iov = { + .iov_base = (void*) req, + .iov_len = req->nlmsg_len + }; + struct msghdr msg = { + .msg_name = &nladdr, + .msg_namelen = sizeof(nladdr), + .msg_iov = &iov, + .msg_iovlen = 1, + }; + int status; + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + + req->nlmsg_seq = ++fd->seq; + + status = sendmsg(fd->fd, &msg, 0); + if (status < 0) { + nhrp_perror("Cannot talk to rtnetlink"); + return FALSE; + } + return TRUE; +} + +static int netlink_talk(struct netlink_fd *fd, struct nlmsghdr *req, + size_t replysize, struct nlmsghdr *reply) +{ + if (reply == NULL) + req->nlmsg_flags |= NLM_F_ACK; + + if (!netlink_send(fd, req)) + return FALSE; + + if (reply == NULL) + return TRUE; + + reply->nlmsg_len = replysize; + return netlink_receive(fd, reply); +} + +static int netlink_enumerate(struct netlink_fd *fd, int family, int type) +{ + struct { + struct nlmsghdr nlh; + struct rtgenmsg g; + } req; + struct sockaddr_nl addr; + + memset(&addr, 0, sizeof(addr)); + addr.nl_family = AF_NETLINK; + + memset(&req, 0, sizeof(req)); + req.nlh.nlmsg_len = sizeof(req); + req.nlh.nlmsg_type = type; + req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST; + req.nlh.nlmsg_pid = 0; + req.nlh.nlmsg_seq = ++fd->seq; + req.g.rtgen_family = family; + + return sendto(fd->fd, (void *) &req, sizeof(req), 0, + (struct sockaddr *) &addr, sizeof(addr)) >= 0; +} + +static void netlink_read_cb(struct ev_io *w, int revents) +{ + struct netlink_fd *nfd = container_of(w, struct netlink_fd, io); + + if (revents & EV_READ) + netlink_receive(nfd, NULL); +} + +static int do_get_ioctl(const char *basedev, struct ip_tunnel_parm *p) +{ + struct ifreq ifr; + +#ifdef VALGRIND + /* Valgrind does not have SIOCGETTUNNEL description, so clear + * the memory structs to avoid spurious warnings */ + memset(&ifr, 0, sizeof(ifr)); + memset(p, 0, sizeof(*p)); +#endif + + strncpy(ifr.ifr_name, basedev, IFNAMSIZ); + ifr.ifr_ifru.ifru_data = (void *) p; + if (ioctl(packet_io.fd, SIOCGETTUNNEL, &ifr)) { + nhrp_perror("ioctl(SIOCGETTUNNEL)"); + return FALSE; + } + return TRUE; +} + +#ifndef NHRP_NO_NBMA_GRE + +static int netlink_add_nested_rtattr_u32(struct rtattr *rta, int maxlen, + int type, uint32_t value) +{ + int len = RTA_LENGTH(4); + struct rtattr *subrta; + + if (RTA_ALIGN(rta->rta_len) + len > maxlen) + return FALSE; + + subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len)); + subrta->rta_type = type; + subrta->rta_len = len; + memcpy(RTA_DATA(subrta), &value, 4); + rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len; + return TRUE; +} + +static int netlink_configure_arp(struct nhrp_interface *iface, int pf) +{ + struct { + struct nlmsghdr n; + struct ndtmsg ndtm; + char buf[256]; + } req; + struct { + struct rtattr rta; + char buf[256]; + } parms; + + memset(&req.n, 0, sizeof(req.n)); + memset(&req.ndtm, 0, sizeof(req.ndtm)); + + req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndtmsg)); + req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_REPLACE; + req.n.nlmsg_type = RTM_SETNEIGHTBL; + + req.ndtm.ndtm_family = pf; + + netlink_add_rtattr_l(&req.n, sizeof(req), NDTA_NAME, + "arp_cache", 10); + + parms.rta.rta_type = NDTA_PARMS; + parms.rta.rta_len = RTA_LENGTH(0); + netlink_add_nested_rtattr_u32(&parms.rta, sizeof(parms), + NDTPA_IFINDEX, iface->index); + netlink_add_nested_rtattr_u32(&parms.rta, sizeof(parms), + NDTPA_APP_PROBES, 1); + netlink_add_nested_rtattr_u32(&parms.rta, sizeof(parms), + NDTPA_MCAST_PROBES, 0); + netlink_add_nested_rtattr_u32(&parms.rta, sizeof(parms), + NDTPA_UCAST_PROBES, 0); + + netlink_add_rtattr_l(&req.n, sizeof(req), NDTA_PARMS, + parms.buf, parms.rta.rta_len - RTA_LENGTH(0)); + + return netlink_send(&talk_fd, &req.n); +} + +static int netlink_link_arp_on(struct nhrp_interface *iface) +{ + struct ifreq ifr; + + strncpy(ifr.ifr_name, iface->name, IFNAMSIZ); + if (ioctl(packet_io.fd, SIOCGIFFLAGS, &ifr)) { + nhrp_perror("ioctl(SIOCGIFFLAGS)"); + return FALSE; + } + if (ifr.ifr_flags & IFF_NOARP) { + ifr.ifr_flags &= ~IFF_NOARP; + if (ioctl(packet_io.fd, SIOCSIFFLAGS, &ifr)) { + nhrp_perror("ioctl(SIOCSIFFLAGS)"); + return FALSE; + } + } + return TRUE; +} + +#else + +static int netlink_configure_arp(struct nhrp_interface *iface, int pf) +{ + return TRUE; +} + +static int netlink_link_arp_on(struct nhrp_interface *iface) +{ + return TRUE; +} + +#endif + +static int proc_icmp_redirect_off(const char *interface) +{ + char fname[256]; + int fd, ret = FALSE; + + sprintf(fname, "/proc/sys/net/ipv4/conf/%s/send_redirects", interface); + fd = open(fname, O_WRONLY); + if (fd < 0) + return FALSE; + if (write(fd, "0\n", 2) == 2) + ret = TRUE; + close(fd); + + return ret; +} + +static void netlink_neigh_request(struct nlmsghdr *msg) +{ + struct ndmsg *ndm = NLMSG_DATA(msg); + struct rtattr *rta[NDA_MAX+1]; + struct nhrp_peer *peer; + struct nhrp_address addr; + struct nhrp_interface *iface; + char tmp[64]; + + netlink_parse_rtattr(rta, NDA_MAX, NDA_RTA(ndm), NDA_PAYLOAD(msg)); + if (rta[NDA_DST] == NULL) + return; + + iface = nhrp_interface_get_by_index(ndm->ndm_ifindex, 0); + if (iface == NULL) + return; + + nhrp_address_set(&addr, ndm->ndm_family, + RTA_PAYLOAD(rta[NDA_DST]), + RTA_DATA(rta[NDA_DST])); + + nhrp_debug("NL-ARP(%s) who-has %s", + iface->name, nhrp_address_format(&addr, sizeof(tmp), tmp)); + + peer = nhrp_peer_route(iface, &addr, 0, ~BIT(NHRP_PEER_TYPE_LOCAL_ROUTE)); + if (peer == NULL) + return; + + if (peer->flags & NHRP_PEER_FLAG_UP) + kernel_inject_neighbor(&addr, &peer->next_hop_address, iface); + + if (peer->next_hop_address.type != PF_UNSPEC && + nhrp_address_cmp(&addr, &peer->protocol_address) != 0) + nhrp_peer_traffic_indication(iface, peer->afnum, &addr); +} + +static void netlink_neigh_update(struct nlmsghdr *msg) +{ + struct ndmsg *ndm = NLMSG_DATA(msg); + struct rtattr *rta[NDA_MAX+1]; + struct nhrp_interface *iface; + struct nhrp_peer_selector sel; + int used = FALSE; + + netlink_parse_rtattr(rta, NDA_MAX, NDA_RTA(ndm), NDA_PAYLOAD(msg)); + if (rta[NDA_DST] == NULL) + return; + + if (!(ndm->ndm_state & (NUD_STALE | NUD_FAILED | NUD_REACHABLE))) + return; + + iface = nhrp_interface_get_by_index(ndm->ndm_ifindex, 0); + if (iface == NULL) + return; + + memset(&sel, 0, sizeof(sel)); + sel.flags = NHRP_PEER_FIND_EXACT; + sel.interface = iface; + nhrp_address_set(&sel.protocol_address, ndm->ndm_family, + RTA_PAYLOAD(rta[NDA_DST]), + RTA_DATA(rta[NDA_DST])); + + if (msg->nlmsg_type == RTM_NEWNEIGH && (ndm->ndm_state & NUD_REACHABLE)) + used = TRUE; + + nhrp_peer_foreach(nhrp_peer_set_used_matching, + (void*) (intptr_t) used, &sel); +} + +static void netlink_link_new(struct nlmsghdr *msg) +{ + struct nhrp_interface *iface; + struct ifinfomsg *ifi = NLMSG_DATA(msg); + struct rtattr *rta[IFLA_MAX+1]; + const char *ifname; + struct ip_tunnel_parm cfg; + int configuration_changed = FALSE; + + netlink_parse_rtattr(rta, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(msg)); + if (rta[IFLA_IFNAME] == NULL) + return; + + ifname = RTA_DATA(rta[IFLA_IFNAME]); + iface = nhrp_interface_get_by_name(ifname, TRUE); + if (iface == NULL) + return; + + if (rta[IFLA_MTU]) + iface->mtu = *((unsigned*)RTA_DATA(rta[IFLA_MTU])); + + if (iface->index == 0 || (ifi->ifi_flags & ifi->ifi_change & IFF_UP)) { + nhrp_info("Interface %s: new or configured up, mtu=%d", + ifname, iface->mtu); + nhrp_interface_run_script(iface, "interface-up"); + } else { + nhrp_info("Interface %s: config change, mtu=%d", + ifname, iface->mtu); + } + + iface->index = ifi->ifi_index; + nhrp_interface_hash(iface); + + if (!(iface->flags & NHRP_INTERFACE_FLAG_CONFIGURED)) + return; + + switch (ifi->ifi_type) { + case ARPHRD_IPGRE: + iface->afnum = AFNUM_INET; + /* try hard to get the interface nbma address */ + do_get_ioctl(ifname, &cfg); + if (iface->gre_key != ntohl(cfg.i_key)) { + configuration_changed = TRUE; + iface->gre_key = ntohl(cfg.i_key); + } + if (cfg.iph.saddr) { + struct nhrp_address saddr; + nhrp_address_set(&saddr, PF_INET, 4, (uint8_t *) &cfg.iph.saddr); + if (nhrp_address_cmp(&iface->nbma_address, &saddr) || iface->link_index) { + configuration_changed = TRUE; + iface->nbma_address = saddr; + iface->link_index = 0; + } + } else if (cfg.link) { + if (cfg.link != iface->link_index) { + configuration_changed = TRUE; + nhrp_address_set_type(&iface->nbma_address, PF_UNSPEC); + iface->link_index = cfg.link; + } + } else { + if (iface->link_index || iface->nbma_address.type != PF_UNSPEC) { + configuration_changed = TRUE; + /* Mark the interface as owning all NBMA addresses + * this works when there's only one GRE interface */ + iface->link_index = 0; + nhrp_address_set_type(&iface->nbma_address, PF_UNSPEC); + nhrp_info("WARNING: Cannot figure out NBMA address for " + "interface '%s'. Using route hints.", ifname); + } + } + break; + } + + if (!(iface->flags & NHRP_INTERFACE_FLAG_SHORTCUT_DEST)) { + netlink_configure_arp(iface, PF_INET); + netlink_link_arp_on(iface); + proc_icmp_redirect_off(iface->name); + } + + if (configuration_changed) { + struct nhrp_peer_selector sel; + int count = 0; + + /* Reset the interface values we detect later */ + memset(&iface->nat_cie, 0, sizeof(iface->nat_cie)); + iface->nbma_mtu = 0; + if (iface->link_index) { + /* Reenumerate addresses if needed */ + netlink_enumerate(&talk_fd, PF_UNSPEC, RTM_GETADDR); + netlink_read_cb(&talk_fd.io, EV_READ); + } + + /* Purge all NHRP entries for this interface */ + memset(&sel, 0, sizeof(sel)); + sel.type_mask = NHRP_PEER_TYPEMASK_PURGEABLE; + sel.interface = iface; + nhrp_peer_foreach(nhrp_peer_purge_matching, &count, &sel); + nhrp_info("Interface %s: GRE configuration changed. Purged %d peers.", + ifname, count); + } +} + +static void netlink_link_del(struct nlmsghdr *msg) +{ + struct nhrp_interface *iface; + struct ifinfomsg *ifi = NLMSG_DATA(msg); + struct rtattr *rta[IFLA_MAX+1]; + const char *ifname; + + netlink_parse_rtattr(rta, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(msg)); + if (rta[IFLA_IFNAME] == NULL) + return; + + ifname = RTA_DATA(rta[IFLA_IFNAME]); + iface = nhrp_interface_get_by_name(ifname, FALSE); + if (iface == NULL) + return; + + nhrp_info("Interface '%s' deleted", ifname); + iface->index = 0; + iface->link_index = 0; + nhrp_interface_hash(iface); + + nhrp_address_set_type(&iface->nbma_address, PF_UNSPEC); + nhrp_address_set_type(&iface->protocol_address, PF_UNSPEC); +} + +static int netlink_addr_new_nbma(void *ctx, struct nhrp_interface *iface) +{ + struct nlmsghdr *msg = (struct nlmsghdr *) ctx; + struct ifaddrmsg *ifa = NLMSG_DATA(msg); + struct rtattr *rta[IFA_MAX+1]; + struct nhrp_interface *nbma_iface; + + if (iface->link_index == ifa->ifa_index) { + netlink_parse_rtattr(rta, IFA_MAX, IFA_RTA(ifa), + IFA_PAYLOAD(msg)); + + if (rta[IFA_LOCAL] == NULL) + return 0; + + nhrp_address_set(&iface->nbma_address, ifa->ifa_family, + RTA_PAYLOAD(rta[IFA_LOCAL]), + RTA_DATA(rta[IFA_LOCAL])); + + nbma_iface = nhrp_interface_get_by_index(ifa->ifa_index, FALSE); + if (nbma_iface != NULL) { + iface->nbma_mtu = translate_mtu(nbma_iface->mtu); + } + } + + return 0; +} + +static void netlink_addr_new(struct nlmsghdr *msg) +{ + struct nhrp_interface *iface; + struct nhrp_peer *peer, *bcast; + struct ifaddrmsg *ifa = NLMSG_DATA(msg); + struct rtattr *rta[IFA_MAX+1]; + + if (!(ifa->ifa_flags & IFA_F_SECONDARY)) + nhrp_interface_foreach(netlink_addr_new_nbma, msg); + + netlink_parse_rtattr(rta, IFA_MAX, IFA_RTA(ifa), IFA_PAYLOAD(msg)); + iface = nhrp_interface_get_by_index(ifa->ifa_index, FALSE); + if (iface == NULL || rta[IFA_LOCAL] == NULL) + return; + + /* Shortcut destination stuff is extracted from routes; + * not from local address information. */ + if (iface->flags & NHRP_INTERFACE_FLAG_SHORTCUT_DEST) + return; + if (!(iface->flags & NHRP_INTERFACE_FLAG_CONFIGURED)) + return; + + nhrp_address_set(&iface->protocol_address, ifa->ifa_family, + RTA_PAYLOAD(rta[IFA_LOCAL]), + RTA_DATA(rta[IFA_LOCAL])); + iface->protocol_address_prefix = ifa->ifa_prefixlen; + + peer = nhrp_peer_alloc(iface); + peer->type = NHRP_PEER_TYPE_LOCAL_ADDR; + peer->afnum = AFNUM_RESERVED; + nhrp_address_set(&peer->protocol_address, ifa->ifa_family, + RTA_PAYLOAD(rta[IFA_LOCAL]), + RTA_DATA(rta[IFA_LOCAL])); + switch (ifa->ifa_family) { + case PF_INET: + peer->protocol_type = ETHPROTO_IP; + peer->prefix_length = peer->protocol_address.addr_len * 8; + nhrp_peer_insert(peer); + break; + default: + nhrp_peer_put(peer); + return; + } + + bcast = nhrp_peer_alloc(iface); + bcast->type = peer->type; + bcast->afnum = peer->afnum; + bcast->protocol_type = peer->protocol_type; + bcast->prefix_length = peer->prefix_length; + bcast->protocol_address = peer->protocol_address; + nhrp_address_set_broadcast(&bcast->protocol_address, + ifa->ifa_prefixlen); + bcast->next_hop_address = peer->protocol_address; + nhrp_peer_insert(bcast); + nhrp_peer_put(bcast); + + nhrp_peer_put(peer); +} + +struct netlink_del_addr_msg { + int interface_index; + struct nhrp_address address; +}; + +static int netlink_addr_del_nbma(void *ctx, struct nhrp_interface *iface) +{ + struct netlink_del_addr_msg *msg = (struct netlink_del_addr_msg *) ctx; + + if (iface->link_index == msg->interface_index && + nhrp_address_cmp(&msg->address, &iface->nbma_address) == 0) + nhrp_address_set_type(&iface->nbma_address, PF_UNSPEC); + + return 0; +} + +static int netlink_addr_purge_nbma(void *ctx, struct nhrp_peer *peer) +{ + struct netlink_del_addr_msg *msg = (struct netlink_del_addr_msg *) ctx; + + if (nhrp_address_cmp(&peer->my_nbma_address, &msg->address) == 0) + nhrp_peer_purge(peer, "address-removed"); + + return 0; +} + +static void netlink_addr_del(struct nlmsghdr *nlmsg) +{ + struct netlink_del_addr_msg msg; + struct nhrp_interface *iface; + struct ifaddrmsg *ifa = NLMSG_DATA(nlmsg); + struct rtattr *rta[IFA_MAX+1]; + struct nhrp_peer_selector sel; + + netlink_parse_rtattr(rta, IFA_MAX, IFA_RTA(ifa), IFA_PAYLOAD(nlmsg)); + if (rta[IFA_LOCAL] == NULL) + return; + + msg.interface_index = ifa->ifa_index; + nhrp_address_set(&msg.address, ifa->ifa_family, + RTA_PAYLOAD(rta[IFA_LOCAL]), + RTA_DATA(rta[IFA_LOCAL])); + + if (!(ifa->ifa_flags & IFA_F_SECONDARY)) + nhrp_interface_foreach(netlink_addr_del_nbma, &msg); + nhrp_peer_foreach(netlink_addr_purge_nbma, &msg, NULL); + + iface = nhrp_interface_get_by_index(ifa->ifa_index, FALSE); + if (iface == NULL) + return; + + memset(&sel, 0, sizeof(sel)); + sel.flags = NHRP_PEER_FIND_EXACT; + sel.type_mask = BIT(NHRP_PEER_TYPE_LOCAL_ADDR); + sel.interface = iface; + sel.protocol_address = msg.address; + sel.prefix_length = sel.protocol_address.addr_len * 8; + + if (nhrp_address_cmp(&sel.protocol_address, &iface->protocol_address) == 0) + nhrp_address_set_type(&iface->protocol_address, PF_UNSPEC); + nhrp_peer_foreach(nhrp_peer_remove_matching, NULL, &sel); + + nhrp_address_set_broadcast(&sel.protocol_address, ifa->ifa_prefixlen); + sel.next_hop_address = msg.address; + nhrp_peer_foreach(nhrp_peer_remove_matching, NULL, &sel); +} + +static void netlink_route_new(struct nlmsghdr *msg) +{ + struct nhrp_interface *iface; + struct nhrp_peer *peer; + struct rtmsg *rtm = NLMSG_DATA(msg); + struct rtattr *rta[RTA_MAX+1]; + int type = 0; + + netlink_parse_rtattr(rta, RTA_MAX, RTM_RTA(rtm), RTM_PAYLOAD(msg)); + if (rta[RTA_OIF] == NULL || rta[RTA_DST] == NULL) + return; + + if (rtm->rtm_family != PF_INET) + return; + + iface = nhrp_interface_get_by_index(*(int*)RTA_DATA(rta[RTA_OIF]), + FALSE); + if (iface == NULL) + return; + + if (iface->flags & NHRP_INTERFACE_FLAG_SHORTCUT_DEST) { + /* Local shortcut target routes */ + if (rtm->rtm_table != RT_TABLE_MAIN) + return; + type = NHRP_PEER_TYPE_LOCAL_ADDR; + } else if (iface->flags & NHRP_INTERFACE_FLAG_CONFIGURED) { + /* Routes which might get additional outbound + * shortcuts */ + if (rtm->rtm_table != iface->route_table || + rtm->rtm_protocol == RTPROT_KERNEL) + return; + type = NHRP_PEER_TYPE_LOCAL_ROUTE; + } + if (type == 0) + return; + + peer = nhrp_peer_alloc(iface); + peer->type = type; + peer->afnum = AFNUM_RESERVED; + nhrp_address_set(&peer->protocol_address, rtm->rtm_family, + RTA_PAYLOAD(rta[RTA_DST]), + RTA_DATA(rta[RTA_DST])); + if (rta[RTA_GATEWAY] != NULL) { + nhrp_address_set(&peer->next_hop_address, + rtm->rtm_family, + RTA_PAYLOAD(rta[RTA_GATEWAY]), + RTA_DATA(rta[RTA_GATEWAY])); + } + peer->protocol_type = nhrp_protocol_from_pf(rtm->rtm_family); + peer->prefix_length = rtm->rtm_dst_len; + nhrp_peer_insert(peer); + nhrp_peer_put(peer); +} + +static void netlink_route_del(struct nlmsghdr *msg) +{ + struct nhrp_interface *iface; + struct rtmsg *rtm = NLMSG_DATA(msg); + struct rtattr *rta[RTA_MAX+1]; + struct nhrp_peer_selector sel; + int type = 0; + + netlink_parse_rtattr(rta, RTA_MAX, RTM_RTA(rtm), RTM_PAYLOAD(msg)); + if (rta[RTA_OIF] == NULL || rta[RTA_DST] == NULL) + return; + + if (rtm->rtm_family != PF_INET) + return; + + iface = nhrp_interface_get_by_index(*(int*)RTA_DATA(rta[RTA_OIF]), + FALSE); + if (iface == NULL) + return; + + if (iface->flags & NHRP_INTERFACE_FLAG_SHORTCUT_DEST) { + /* Local shortcut target routes */ + if (rtm->rtm_table != RT_TABLE_MAIN) + return; + type = NHRP_PEER_TYPE_LOCAL_ADDR; + } else if (iface->flags & NHRP_INTERFACE_FLAG_CONFIGURED) { + /* Routes which might get additional outbound + * shortcuts */ + if (rtm->rtm_table != iface->route_table || + rtm->rtm_protocol == RTPROT_KERNEL) + return; + type = NHRP_PEER_TYPE_LOCAL_ROUTE; + } + if (type == 0) + return; + + memset(&sel, 0, sizeof(sel)); + sel.flags = NHRP_PEER_FIND_EXACT; + sel.type_mask = BIT(type); + sel.interface = iface; + nhrp_address_set(&sel.protocol_address, rtm->rtm_family, + RTA_PAYLOAD(rta[RTA_DST]), + RTA_DATA(rta[RTA_DST])); + if (rta[RTA_GATEWAY] != NULL) { + nhrp_address_set(&sel.next_hop_address, + rtm->rtm_family, + RTA_PAYLOAD(rta[RTA_GATEWAY]), + RTA_DATA(rta[RTA_GATEWAY])); + } + sel.prefix_length = rtm->rtm_dst_len; + nhrp_peer_foreach(nhrp_peer_remove_matching, NULL, &sel); +} + +static const netlink_dispatch_f route_dispatch[RTM_MAX] = { + [RTM_GETNEIGH] = netlink_neigh_request, + [RTM_NEWNEIGH] = netlink_neigh_update, + [RTM_DELNEIGH] = netlink_neigh_update, + [RTM_NEWLINK] = netlink_link_new, + [RTM_DELLINK] = netlink_link_del, + [RTM_NEWADDR] = netlink_addr_new, + [RTM_DELADDR] = netlink_addr_del, + [RTM_NEWROUTE] = netlink_route_new, + [RTM_DELROUTE] = netlink_route_del, +}; + +static void netlink_stop_listening(struct netlink_fd *fd) +{ + ev_io_stop(&fd->io); +} + +static void netlink_close(struct netlink_fd *fd) +{ + if (fd->fd >= 0) { + netlink_stop_listening(fd); + close(fd->fd); + fd->fd = 0; + } +} + +static int netlink_open(struct netlink_fd *fd, int protocol, int groups) +{ + struct sockaddr_nl addr; + int buf = NETLINK_KERNEL_BUFFER; + + fd->fd = socket(AF_NETLINK, SOCK_RAW, protocol); + fd->seq = time(NULL); + if (fd->fd < 0) { + nhrp_perror("Cannot open netlink socket"); + return FALSE; + } + + fcntl(fd->fd, F_SETFD, FD_CLOEXEC); + if (setsockopt(fd->fd, SOL_SOCKET, SO_SNDBUF, &buf, sizeof(buf)) < 0) { + nhrp_perror("SO_SNDBUF"); + goto error; + } + + if (setsockopt(fd->fd, SOL_SOCKET, SO_RCVBUF, &buf, sizeof(buf)) < 0) { + nhrp_perror("SO_RCVBUF"); + goto error; + } + + memset(&addr, 0, sizeof(addr)); + addr.nl_family = AF_NETLINK; + addr.nl_groups = groups; + if (bind(fd->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { + nhrp_perror("Cannot bind netlink socket"); + goto error; + } + + ev_io_init(&fd->io, netlink_read_cb, fd->fd, EV_READ); + ev_io_start(&fd->io); + + return TRUE; + +error: + netlink_close(fd); + return FALSE; +} + +static void pfpacket_read_cb(struct ev_io *w, int revents) +{ + struct sockaddr_ll lladdr; + struct nhrp_interface *iface; + struct iovec iov; + struct msghdr msg = { + .msg_name = &lladdr, + .msg_namelen = sizeof(lladdr), + .msg_iov = &iov, + .msg_iovlen = 1, + }; + uint8_t buf[1500]; + struct nhrp_address from; + int fd = w->fd; + int i; + + iov.iov_base = buf; + for (i = 0; i < 2; i++) { + int status; + + iov.iov_len = sizeof(buf); + status = recvmsg(fd, &msg, MSG_DONTWAIT); + if (status < 0) { + if (errno == EINTR) + continue; + if (errno == EAGAIN) + return; + nhrp_perror("PF_PACKET overrun"); + continue; + } + + if (status == 0) { + nhrp_error("PF_PACKET returned EOF"); + return; + } + + iface = nhrp_interface_get_by_index(lladdr.sll_ifindex, FALSE); + if (iface == NULL) + continue; + + nhrp_address_set(&from, PF_INET, lladdr.sll_halen, lladdr.sll_addr); + if (memcmp(lladdr.sll_addr, "\x00\x00\x00\x00", 4) == 0) + nhrp_address_set_type(&from, PF_UNSPEC); + nhrp_packet_receive(buf, status, iface, &from); + } +} + +int kernel_init(void) +{ + int fd, i; + + proc_icmp_redirect_off("all"); + + fd = socket(PF_PACKET, SOCK_DGRAM, ETHPROTO_NHRP); + if (fd < 0) { + nhrp_error("Unable to create PF_PACKET socket"); + return FALSE; + } + + fcntl(fd, F_SETFD, FD_CLOEXEC); + ev_io_init(&packet_io, pfpacket_read_cb, fd, EV_READ); + ev_io_start(&packet_io); + + for (i = 0; i < ARRAY_SIZE(netlink_groups); i++) { + netlink_fds[i].dispatch_size = sizeof(route_dispatch) / sizeof(route_dispatch[0]); + netlink_fds[i].dispatch = route_dispatch; + if (!netlink_open(&netlink_fds[i], NETLINK_ROUTE, + netlink_groups[i])) + goto err_close_all; + } + + netlink_enumerate(&talk_fd, PF_UNSPEC, RTM_GETLINK); + netlink_read_cb(&talk_fd.io, EV_READ); + + netlink_enumerate(&talk_fd, PF_UNSPEC, RTM_GETADDR); + netlink_read_cb(&talk_fd.io, EV_READ); + + netlink_enumerate(&talk_fd, PF_UNSPEC, RTM_GETROUTE); + netlink_read_cb(&talk_fd.io, EV_READ); + + return TRUE; + +err_close_all: + kernel_cleanup(); + return FALSE; +} + +void kernel_stop_listening(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(netlink_groups); i++) + netlink_stop_listening(&netlink_fds[i]); + ev_io_stop(&packet_io); +} + +void kernel_cleanup(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(netlink_groups); i++) + netlink_close(&netlink_fds[i]); + ev_io_stop(&packet_io); + close(packet_io.fd); +} + +int kernel_route(struct nhrp_interface *out_iface, + struct nhrp_address *dest, + struct nhrp_address *default_source, + struct nhrp_address *next_hop, + u_int16_t *mtu) +{ + struct { + struct nlmsghdr n; + struct rtmsg r; + char buf[1024]; + } req; + struct rtmsg *r = NLMSG_DATA(&req.n); + struct rtattr *rta[RTA_MAX+1]; + + memset(&req, 0, sizeof(req)); + req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); + req.n.nlmsg_flags = NLM_F_REQUEST; + req.n.nlmsg_type = RTM_GETROUTE; + req.r.rtm_family = dest->type; + + netlink_add_rtattr_l(&req.n, sizeof(req), RTA_DST, + dest->addr, dest->addr_len); + req.r.rtm_dst_len = dest->addr_len * 8; + + if (default_source != NULL && default_source->type != PF_UNSPEC) + netlink_add_rtattr_l(&req.n, sizeof(req), RTA_SRC, + default_source->addr, + default_source->addr_len); + if (out_iface != NULL) + netlink_add_rtattr_l(&req.n, sizeof(req), RTA_OIF, + &out_iface->index, sizeof(int)); + + if (!netlink_talk(&talk_fd, &req.n, sizeof(req), &req.n)) + return FALSE; + + netlink_parse_rtattr(rta, RTA_MAX, RTM_RTA(r), RTM_PAYLOAD(&req.n)); + + if (default_source != NULL && default_source->type == PF_UNSPEC && + rta[RTA_PREFSRC] != NULL) { + nhrp_address_set(default_source, dest->type, + RTA_PAYLOAD(rta[RTA_PREFSRC]), + RTA_DATA(rta[RTA_PREFSRC])); + } + + if (next_hop != NULL) { + if (rta[RTA_GATEWAY] != NULL) { + nhrp_address_set(next_hop, dest->type, + RTA_PAYLOAD(rta[RTA_GATEWAY]), + RTA_DATA(rta[RTA_GATEWAY])); + } else { + *next_hop = *dest; + } + } + + if (mtu != NULL) { + *mtu = 0; + + if (rta[RTA_OIF] != NULL) { + struct nhrp_interface *nbma_iface; + + /* We use interface MTU here instead of the route + * cache MTU from RTA_METRICS/RTAX_MTU since we + * don't want to announce mtu if PMTU works */ + nbma_iface = nhrp_interface_get_by_index( + *(int*)RTA_DATA(rta[RTA_OIF]), + FALSE); + if (nbma_iface != NULL) + *mtu = translate_mtu(nbma_iface->mtu); + } + } + + return TRUE; +} + +int kernel_send(uint8_t *packet, size_t bytes, struct nhrp_interface *out, + struct nhrp_address *to) +{ + struct sockaddr_ll lladdr; + struct iovec iov = { + .iov_base = (void*) packet, + .iov_len = bytes + }; + struct msghdr msg = { + .msg_name = &lladdr, + .msg_namelen = sizeof(lladdr), + .msg_iov = &iov, + .msg_iovlen = 1, + }; + int status; + + if (to->addr_len > sizeof(lladdr.sll_addr)) { + nhrp_error("Destination NBMA address too long"); + return FALSE; + } + + memset(&lladdr, 0, sizeof(lladdr)); + lladdr.sll_family = AF_PACKET; + lladdr.sll_protocol = ETHPROTO_NHRP; + lladdr.sll_ifindex = out->index; + lladdr.sll_halen = to->addr_len; + memcpy(lladdr.sll_addr, to->addr, to->addr_len); + + status = sendmsg(packet_io.fd, &msg, 0); + if (status < 0) { + nhrp_error("Cannot send packet to %s(%d): %s", + out->name, out->index, strerror(errno)); + return FALSE; + } + + return TRUE; +} + +int kernel_inject_neighbor(struct nhrp_address *neighbor, + struct nhrp_address *hwaddr, + struct nhrp_interface *dev) +{ + struct { + struct nlmsghdr n; + struct ndmsg ndm; + char buf[256]; + } req; + char neigh[64], nbma[64]; + + memset(&req.n, 0, sizeof(req.n)); + memset(&req.ndm, 0, sizeof(req.ndm)); + + req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)); + req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_REPLACE | NLM_F_CREATE; + req.n.nlmsg_type = RTM_NEWNEIGH; + req.ndm.ndm_family = neighbor->type; + req.ndm.ndm_ifindex = dev->index; + req.ndm.ndm_type = RTN_UNICAST; + + netlink_add_rtattr_l(&req.n, sizeof(req), NDA_DST, + neighbor->addr, neighbor->addr_len); + + if (hwaddr != NULL && hwaddr->type != PF_UNSPEC) { + req.ndm.ndm_state = NUD_REACHABLE; + + netlink_add_rtattr_l(&req.n, sizeof(req), NDA_LLADDR, + hwaddr->addr, hwaddr->addr_len); + + nhrp_debug("NL-ARP(%s) %s is-at %s", + dev->name, + nhrp_address_format(neighbor, sizeof(neigh), neigh), + nhrp_address_format(hwaddr, sizeof(nbma), nbma)); + } else { + req.ndm.ndm_state = NUD_FAILED; + + nhrp_debug("NL-ARP(%s) %s not-reachable", + dev->name, + nhrp_address_format(neighbor, sizeof(neigh), neigh)); + } + + return netlink_send(&talk_fd, &req.n); +} + |