--- /dev/null
+/*
+ * BIRD -- Linux Netlink Interface
+ *
+ * (c) 1999--2000 Martin Mares <mj@ucw.cz>
+ *
+ * Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <errno.h>
+
+#undef LOCAL_DEBUG
+
+#include "nest/bird.h"
+#include "nest/route.h"
+#include "nest/protocol.h"
+#include "nest/iface.h"
+#include "lib/alloca.h"
+#include "lib/timer.h"
+#include "lib/unix.h"
+#include "lib/krt.h"
+#include "lib/socket.h"
+#include "lib/string.h"
+#include "conf/conf.h"
+
+#include <asm/types.h>
+#include <linux/if.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#ifndef MSG_TRUNC /* Hack: Several versions of glibc miss this one :( */
+#define MSG_TRUNC 0x20
+#endif
+
+#ifndef IFF_LOWER_UP
+#define IFF_LOWER_UP 0x10000
+#endif
+
+/*
+ * Synchronous Netlink interface
+ */
+
+struct nl_sock
+{
+ int fd;
+ u32 seq;
+ byte *rx_buffer; /* Receive buffer */
+ struct nlmsghdr *last_hdr; /* Recently received packet */
+ unsigned int last_size;
+};
+
+#define NL_RX_SIZE 8192
+
+static struct nl_sock nl_scan = {.fd = -1}; /* Netlink socket for synchronous scan */
+static struct nl_sock nl_req = {.fd = -1}; /* Netlink socket for requests */
+
+static void
+nl_open_sock(struct nl_sock *nl)
+{
+ if (nl->fd < 0)
+ {
+ nl->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ if (nl->fd < 0)
+ die("Unable to open rtnetlink socket: %m");
+ nl->seq = now;
+ nl->rx_buffer = xmalloc(NL_RX_SIZE);
+ nl->last_hdr = NULL;
+ nl->last_size = 0;
+ }
+}
+
+static void
+nl_open(void)
+{
+ nl_open_sock(&nl_scan);
+ nl_open_sock(&nl_req);
+}
+
+static void
+nl_send(struct nl_sock *nl, struct nlmsghdr *nh)
+{
+ struct sockaddr_nl sa;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.nl_family = AF_NETLINK;
+ nh->nlmsg_pid = 0;
+ nh->nlmsg_seq = ++(nl->seq);
+ if (sendto(nl->fd, nh, nh->nlmsg_len, 0, (struct sockaddr *)&sa, sizeof(sa)) < 0)
+ die("rtnetlink sendto: %m");
+ nl->last_hdr = NULL;
+}
+
+static void
+nl_request_dump(int cmd)
+{
+ struct {
+ struct nlmsghdr nh;
+ struct rtgenmsg g;
+ } req;
+ req.nh.nlmsg_type = cmd;
+ req.nh.nlmsg_len = sizeof(req);
+ req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+ /* Is it important which PF_* is used for link-level interface scan?
+ It seems that some information is available only when PF_INET is used. */
+ req.g.rtgen_family = (cmd == RTM_GETLINK) ? PF_INET : BIRD_PF;
+ nl_send(&nl_scan, &req.nh);
+}
+
+static struct nlmsghdr *
+nl_get_reply(struct nl_sock *nl)
+{
+ for(;;)
+ {
+ if (!nl->last_hdr)
+ {
+ struct iovec iov = { nl->rx_buffer, NL_RX_SIZE };
+ struct sockaddr_nl sa;
+ struct msghdr m = { (struct sockaddr *) &sa, sizeof(sa), &iov, 1, NULL, 0, 0 };
+ int x = recvmsg(nl->fd, &m, 0);
+ if (x < 0)
+ die("nl_get_reply: %m");
+ if (sa.nl_pid) /* It isn't from the kernel */
+ {
+ DBG("Non-kernel packet\n");
+ continue;
+ }
+ nl->last_size = x;
+ nl->last_hdr = (void *) nl->rx_buffer;
+ if (m.msg_flags & MSG_TRUNC)
+ bug("nl_get_reply: got truncated reply which should be impossible");
+ }
+ if (NLMSG_OK(nl->last_hdr, nl->last_size))
+ {
+ struct nlmsghdr *h = nl->last_hdr;
+ nl->last_hdr = NLMSG_NEXT(h, nl->last_size);
+ if (h->nlmsg_seq != nl->seq)
+ {
+ log(L_WARN "nl_get_reply: Ignoring out of sequence netlink packet (%x != %x)",
+ h->nlmsg_seq, nl->seq);
+ continue;
+ }
+ return h;
+ }
+ if (nl->last_size)
+ log(L_WARN "nl_get_reply: Found packet remnant of size %d", nl->last_size);
+ nl->last_hdr = NULL;
+ }
+}
+
+static struct rate_limit rl_netlink_err;
+
+static int
+nl_error(struct nlmsghdr *h)
+{
+ struct nlmsgerr *e;
+ int ec;
+
+ if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
+ {
+ log(L_WARN "Netlink: Truncated error message received");
+ return ENOBUFS;
+ }
+ e = (struct nlmsgerr *) NLMSG_DATA(h);
+ ec = -e->error;
+ if (ec)
+ log_rl(&rl_netlink_err, L_WARN "Netlink: %s", strerror(ec));
+ return ec;
+}
+
+static struct nlmsghdr *
+nl_get_scan(void)
+{
+ struct nlmsghdr *h = nl_get_reply(&nl_scan);
+
+ if (h->nlmsg_type == NLMSG_DONE)
+ return NULL;
+ if (h->nlmsg_type == NLMSG_ERROR)
+ {
+ nl_error(h);
+ return NULL;
+ }
+ return h;
+}
+
+static int
+nl_exchange(struct nlmsghdr *pkt)
+{
+ struct nlmsghdr *h;
+
+ nl_send(&nl_req, pkt);
+ for(;;)
+ {
+ h = nl_get_reply(&nl_req);
+ if (h->nlmsg_type == NLMSG_ERROR)
+ break;
+ log(L_WARN "nl_exchange: Unexpected reply received");
+ }
+ return nl_error(h) ? -1 : 0;
+}
+
+/*
+ * Netlink attributes
+ */
+
+static int nl_attr_len;
+
+static void *
+nl_checkin(struct nlmsghdr *h, int lsize)
+{
+ nl_attr_len = h->nlmsg_len - NLMSG_LENGTH(lsize);
+ if (nl_attr_len < 0)
+ {
+ log(L_ERR "nl_checkin: underrun by %d bytes", -nl_attr_len);
+ return NULL;
+ }
+ return NLMSG_DATA(h);
+}
+
+static int
+nl_parse_attrs(struct rtattr *a, struct rtattr **k, int ksize)
+{
+ int max = ksize / sizeof(struct rtattr *);
+ bzero(k, ksize);
+ while (RTA_OK(a, nl_attr_len))
+ {
+ if (a->rta_type < max)
+ k[a->rta_type] = a;
+ a = RTA_NEXT(a, nl_attr_len);
+ }
+ if (nl_attr_len)
+ {
+ log(L_ERR "nl_parse_attrs: remnant of size %d", nl_attr_len);
+ return 0;
+ }
+ else
+ return 1;
+}
+
+void
+nl_add_attr(struct nlmsghdr *h, unsigned bufsize, unsigned code,
+ void *data, unsigned dlen)
+{
+ unsigned len = RTA_LENGTH(dlen);
+ unsigned pos = NLMSG_ALIGN(h->nlmsg_len);
+ struct rtattr *a;
+
+ if (pos + len > bufsize)
+ bug("nl_add_attr: packet buffer overflow");
+ a = (struct rtattr *)((char *)h + pos);
+ a->rta_type = code;
+ a->rta_len = len;
+ h->nlmsg_len = pos + len;
+ memcpy(RTA_DATA(a), data, dlen);
+}
+
+static inline void
+nl_add_attr_u32(struct nlmsghdr *h, unsigned bufsize, int code, u32 data)
+{
+ nl_add_attr(h, bufsize, code, &data, 4);
+}
+
+static inline void
+nl_add_attr_ipa(struct nlmsghdr *h, unsigned bufsize, int code, ip_addr ipa)
+{
+ ipa_hton(ipa);
+ nl_add_attr(h, bufsize, code, &ipa, sizeof(ipa));
+}
+
+#define RTNH_SIZE (sizeof(struct rtnexthop) + sizeof(struct rtattr) + sizeof(ip_addr))
+
+static inline void
+add_mpnexthop(char *buf, ip_addr ipa, unsigned iface, unsigned char weight)
+{
+ struct rtnexthop *nh = (void *) buf;
+ struct rtattr *rt = (void *) (buf + sizeof(*nh));
+ nh->rtnh_len = RTNH_SIZE;
+ nh->rtnh_flags = 0;
+ nh->rtnh_hops = weight;
+ nh->rtnh_ifindex = iface;
+ rt->rta_len = sizeof(*rt) + sizeof(ipa);
+ rt->rta_type = RTA_GATEWAY;
+ ipa_hton(ipa);
+ memcpy(buf + sizeof(*nh) + sizeof(*rt), &ipa, sizeof(ipa));
+}
+
+
+static void
+nl_add_multipath(struct nlmsghdr *h, unsigned bufsize, struct mpnh *nh)
+{
+ unsigned len = sizeof(struct rtattr);
+ unsigned pos = NLMSG_ALIGN(h->nlmsg_len);
+ char *buf = (char *)h + pos;
+ struct rtattr *rt = (void *) buf;
+ buf += len;
+
+ for (; nh; nh = nh->next)
+ {
+ len += RTNH_SIZE;
+ if (pos + len > bufsize)
+ bug("nl_add_multipath: packet buffer overflow");
+
+ add_mpnexthop(buf, nh->gw, nh->iface->index, nh->weight);
+ buf += RTNH_SIZE;
+ }
+
+ rt->rta_type = RTA_MULTIPATH;
+ rt->rta_len = len;
+ h->nlmsg_len = pos + len;
+}
+
+
+static struct mpnh *
+nl_parse_multipath(struct krt_proto *p, struct rtattr *ra)
+{
+ /* Temporary buffer for multicast nexthops */
+ static struct mpnh *nh_buffer;
+ static int nh_buf_size; /* in number of structures */
+ static int nh_buf_used;
+
+ struct rtattr *a[RTA_CACHEINFO+1];
+ struct rtnexthop *nh = RTA_DATA(ra);
+ struct mpnh *rv, *first, **last;
+ int len = RTA_PAYLOAD(ra);
+
+ first = NULL;
+ last = &first;
+ nh_buf_used = 0;
+
+ while (len)
+ {
+ /* Use RTNH_OK(nh,len) ?? */
+ if ((len < sizeof(*nh)) || (len < nh->rtnh_len))
+ return NULL;
+
+ if (nh_buf_used == nh_buf_size)
+ {
+ nh_buf_size = nh_buf_size ? (nh_buf_size * 2) : 4;
+ nh_buffer = xrealloc(nh_buffer, nh_buf_size * sizeof(struct mpnh));
+ }
+ *last = rv = nh_buffer + nh_buf_used++;
+ rv->next = NULL;
+ last = &(rv->next);
+
+ rv->weight = nh->rtnh_hops;
+ rv->iface = if_find_by_index(nh->rtnh_ifindex);
+ if (!rv->iface)
+ return NULL;
+
+ /* Nonexistent RTNH_PAYLOAD ?? */
+ nl_attr_len = nh->rtnh_len - RTNH_LENGTH(0);
+ nl_parse_attrs(RTNH_DATA(nh), a, sizeof(a));
+ if (a[RTA_GATEWAY])
+ {
+ if (RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr))
+ return NULL;
+
+ memcpy(&rv->gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ip_addr));
+ ipa_ntoh(rv->gw);
+
+ neighbor *ng = neigh_find2(&p->p, &rv->gw, rv->iface,
+ (nh->rtnh_flags & RTNH_F_ONLINK) ? NEF_ONLINK : 0);
+ if (!ng || (ng->scope == SCOPE_HOST))
+ return NULL;
+ }
+ else
+ return NULL;
+
+ len -= NLMSG_ALIGN(nh->rtnh_len);
+ nh = RTNH_NEXT(nh);
+ }
+
+ return first;
+}
+
+
+/*
+ * Scanning of interfaces
+ */
+
+static void
+nl_parse_link(struct nlmsghdr *h, int scan)
+{
+ struct ifinfomsg *i;
+ struct rtattr *a[IFLA_WIRELESS+1];
+ int new = h->nlmsg_type == RTM_NEWLINK;
+ struct iface f = {};
+ struct iface *ifi;
+ char *name;
+ u32 mtu;
+ unsigned int fl;
+
+ if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFLA_RTA(i), a, sizeof(a)))
+ return;
+ if (!a[IFLA_IFNAME] || RTA_PAYLOAD(a[IFLA_IFNAME]) < 2 ||
+ !a[IFLA_MTU] || RTA_PAYLOAD(a[IFLA_MTU]) != 4)
+ {
+ if (scan || !a[IFLA_WIRELESS])
+ log(L_ERR "nl_parse_link: Malformed message received");
+ return;
+ }
+ name = RTA_DATA(a[IFLA_IFNAME]);
+ memcpy(&mtu, RTA_DATA(a[IFLA_MTU]), sizeof(u32));
+
+ ifi = if_find_by_index(i->ifi_index);
+ if (!new)
+ {
+ DBG("KIF: IF%d(%s) goes down\n", i->ifi_index, name);
+ if (!ifi)
+ return;
+
+ if_delete(ifi);
+ }
+ else
+ {
+ DBG("KIF: IF%d(%s) goes up (mtu=%d,flg=%x)\n", i->ifi_index, name, mtu, i->ifi_flags);
+ if (ifi && strncmp(ifi->name, name, sizeof(ifi->name)-1))
+ if_delete(ifi);
+
+ strncpy(f.name, name, sizeof(f.name)-1);
+ f.index = i->ifi_index;
+ f.mtu = mtu;
+
+ fl = i->ifi_flags;
+ if (fl & IFF_UP)
+ f.flags |= IF_ADMIN_UP;
+ if (fl & IFF_LOWER_UP)
+ f.flags |= IF_LINK_UP;
+ if (fl & IFF_LOOPBACK) /* Loopback */
+ f.flags |= IF_MULTIACCESS | IF_LOOPBACK | IF_IGNORE;
+ else if (fl & IFF_POINTOPOINT) /* PtP */
+ f.flags |= IF_MULTICAST;
+ else if (fl & IFF_BROADCAST) /* Broadcast */
+ f.flags |= IF_MULTIACCESS | IF_BROADCAST | IF_MULTICAST;
+ else
+ f.flags |= IF_MULTIACCESS; /* NBMA */
+ if_update(&f);
+ }
+}
+
+static void
+nl_parse_addr(struct nlmsghdr *h)
+{
+ struct ifaddrmsg *i;
+ struct rtattr *a[IFA_ANYCAST+1];
+ int new = h->nlmsg_type == RTM_NEWADDR;
+ struct ifa ifa;
+ struct iface *ifi;
+ int scope;
+
+ if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFA_RTA(i), a, sizeof(a)))
+ return;
+ if (i->ifa_family != BIRD_AF)
+ return;
+ if (!a[IFA_ADDRESS] || RTA_PAYLOAD(a[IFA_ADDRESS]) != sizeof(ip_addr)
+#ifdef IPV6
+ || a[IFA_LOCAL] && RTA_PAYLOAD(a[IFA_LOCAL]) != sizeof(ip_addr)
+#else
+ || !a[IFA_LOCAL] || RTA_PAYLOAD(a[IFA_LOCAL]) != sizeof(ip_addr)
+ || (a[IFA_BROADCAST] && RTA_PAYLOAD(a[IFA_BROADCAST]) != sizeof(ip_addr))
+#endif
+ )
+ {
+ log(L_ERR "nl_parse_addr: Malformed message received");
+ return;
+ }
+
+ ifi = if_find_by_index(i->ifa_index);
+ if (!ifi)
+ {
+ log(L_ERR "KIF: Received address message for unknown interface %d", i->ifa_index);
+ return;
+ }
+
+ bzero(&ifa, sizeof(ifa));
+ ifa.iface = ifi;
+ if (i->ifa_flags & IFA_F_SECONDARY)
+ ifa.flags |= IA_SECONDARY;
+
+ /* IFA_LOCAL can be unset for IPv6 interfaces */
+ memcpy(&ifa.ip, RTA_DATA(a[IFA_LOCAL] ? : a[IFA_ADDRESS]), sizeof(ifa.ip));
+ ipa_ntoh(ifa.ip);
+ ifa.pxlen = i->ifa_prefixlen;
+ if (i->ifa_prefixlen > BITS_PER_IP_ADDRESS)
+ {
+ log(L_ERR "KIF: Invalid prefix length for interface %s: %d", ifi->name, i->ifa_prefixlen);
+ new = 0;
+ }
+ if (i->ifa_prefixlen == BITS_PER_IP_ADDRESS)
+ {
+ ip_addr addr;
+ memcpy(&addr, RTA_DATA(a[IFA_ADDRESS]), sizeof(addr));
+ ipa_ntoh(addr);
+ ifa.prefix = ifa.brd = addr;
+
+ /* It is either a host address or a peer address */
+ if (ipa_equal(ifa.ip, addr))
+ ifa.flags |= IA_HOST;
+ else
+ {
+ ifa.flags |= IA_PEER;
+ ifa.opposite = addr;
+ }
+ }
+ else
+ {
+ ip_addr netmask = ipa_mkmask(ifa.pxlen);
+ ifa.prefix = ipa_and(ifa.ip, netmask);
+ ifa.brd = ipa_or(ifa.ip, ipa_not(netmask));
+ if (i->ifa_prefixlen == BITS_PER_IP_ADDRESS - 1)
+ ifa.opposite = ipa_opposite_m1(ifa.ip);
+
+#ifndef IPV6
+ if (i->ifa_prefixlen == BITS_PER_IP_ADDRESS - 2)
+ ifa.opposite = ipa_opposite_m2(ifa.ip);
+
+ if ((ifi->flags & IF_BROADCAST) && a[IFA_BROADCAST])
+ {
+ ip_addr xbrd;
+ memcpy(&xbrd, RTA_DATA(a[IFA_BROADCAST]), sizeof(xbrd));
+ ipa_ntoh(xbrd);
+ if (ipa_equal(xbrd, ifa.prefix) || ipa_equal(xbrd, ifa.brd))
+ ifa.brd = xbrd;
+ else if (ifi->flags & IF_TMP_DOWN) /* Complain only during the first scan */
+ log(L_ERR "KIF: Invalid broadcast address %I for %s", xbrd, ifi->name);
+ }
+#endif
+ }
+
+ scope = ipa_classify(ifa.ip);
+ if (scope < 0)
+ {
+ log(L_ERR "KIF: Invalid interface address %I for %s", ifa.ip, ifi->name);
+ return;
+ }
+ ifa.scope = scope & IADDR_SCOPE_MASK;
+
+ DBG("KIF: IF%d(%s): %s IPA %I, flg %x, net %I/%d, brd %I, opp %I\n",
+ ifi->index, ifi->name,
+ new ? "added" : "removed",
+ ifa.ip, ifa.flags, ifa.prefix, ifa.pxlen, ifa.brd, ifa.opposite);
+ if (new)
+ ifa_update(&ifa);
+ else
+ ifa_delete(&ifa);
+}
+
+void
+kif_do_scan(struct kif_proto *p UNUSED)
+{
+ struct nlmsghdr *h;
+
+ if_start_update();
+
+ nl_request_dump(RTM_GETLINK);
+ while (h = nl_get_scan())
+ if (h->nlmsg_type == RTM_NEWLINK || h->nlmsg_type == RTM_DELLINK)
+ nl_parse_link(h, 1);
+ else
+ log(L_DEBUG "nl_scan_ifaces: Unknown packet received (type=%d)", h->nlmsg_type);
+
+ nl_request_dump(RTM_GETADDR);
+ while (h = nl_get_scan())
+ if (h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_DELADDR)
+ nl_parse_addr(h);
+ else
+ log(L_DEBUG "nl_scan_ifaces: Unknown packet received (type=%d)", h->nlmsg_type);
+
+ if_end_update();
+}
+
+/*
+ * Routes
+ */
+
+static struct krt_proto *nl_table_map[NL_NUM_TABLES];
+
+int
+krt_capable(rte *e)
+{
+ rta *a = e->attrs;
+
+ if (a->cast != RTC_UNICAST)
+ return 0;
+
+ switch (a->dest)
+ {
+ case RTD_ROUTER:
+ case RTD_DEVICE:
+ if (a->iface == NULL)
+ return 0;
+ case RTD_BLACKHOLE:
+ case RTD_UNREACHABLE:
+ case RTD_PROHIBIT:
+ case RTD_MULTIPATH:
+ break;
+ default:
+ return 0;
+ }
+ return 1;
+}
+
+static inline int
+nh_bufsize(struct mpnh *nh)
+{
+ int rv = 0;
+ for (; nh != NULL; nh = nh->next)
+ rv += RTNH_SIZE;
+ return rv;
+}
+
+static int
+nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
+{
+ eattr *ea;
+ net *net = e->net;
+ rta *a = e->attrs;
+ struct {
+ struct nlmsghdr h;
+ struct rtmsg r;
+ char buf[128 + nh_bufsize(a->nexthops)];
+ } r;
+
+ DBG("nl_send_route(%I/%d,new=%d)\n", net->n.prefix, net->n.pxlen, new);
+
+ bzero(&r.h, sizeof(r.h));
+ bzero(&r.r, sizeof(r.r));
+ r.h.nlmsg_type = new ? RTM_NEWROUTE : RTM_DELROUTE;
+ r.h.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+ r.h.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | (new ? NLM_F_CREATE|NLM_F_EXCL : 0);
+
+ r.r.rtm_family = BIRD_AF;
+ r.r.rtm_dst_len = net->n.pxlen;
+ r.r.rtm_tos = 0;
+ r.r.rtm_table = KRT_CF->sys.table_id;
+ r.r.rtm_protocol = RTPROT_BIRD;
+ r.r.rtm_scope = RT_SCOPE_UNIVERSE;
+ nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net->n.prefix);
+
+ u32 metric = 0;
+ if (new && e->attrs->source == RTS_INHERIT)
+ metric = e->u.krt.metric;
+ if (ea = ea_find(eattrs, EA_KRT_METRIC))
+ metric = ea->u.data;
+ if (metric != 0)
+ nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, metric);
+
+ if (ea = ea_find(eattrs, EA_KRT_PREFSRC))
+ nl_add_attr_ipa(&r.h, sizeof(r), RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
+
+ if (ea = ea_find(eattrs, EA_KRT_REALM))
+ nl_add_attr_u32(&r.h, sizeof(r), RTA_FLOW, ea->u.data);
+
+ /* a->iface != NULL checked in krt_capable() for router and device routes */
+
+ switch (a->dest)
+ {
+ case RTD_ROUTER:
+ r.r.rtm_type = RTN_UNICAST;
+ nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
+ nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, a->gw);
+ break;
+ case RTD_DEVICE:
+ r.r.rtm_type = RTN_UNICAST;
+ nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
+ break;
+ case RTD_BLACKHOLE:
+ r.r.rtm_type = RTN_BLACKHOLE;
+ break;
+ case RTD_UNREACHABLE:
+ r.r.rtm_type = RTN_UNREACHABLE;
+ break;
+ case RTD_PROHIBIT:
+ r.r.rtm_type = RTN_PROHIBIT;
+ break;
+ case RTD_MULTIPATH:
+ r.r.rtm_type = RTN_UNICAST;
+ nl_add_multipath(&r.h, sizeof(r), a->nexthops);
+ break;
+ default:
+ bug("krt_capable inconsistent with nl_send_route");
+ }
+
+ return nl_exchange(&r.h);
+}
+
+void
+krt_replace_rte(struct krt_proto *p, net *n, rte *new, rte *old, struct ea_list *eattrs)
+{
+ int err = 0;
+
+ /*
+ * NULL for eattr of the old route is a little hack, but we don't
+ * get proper eattrs for old in rt_notify() anyway. NULL means no
+ * extended route attributes and therefore matches if the kernel
+ * route has any of them.
+ */
+
+ if (old)
+ nl_send_route(p, old, NULL, 0);
+
+ if (new)
+ err = nl_send_route(p, new, eattrs, 1);
+
+ if (err < 0)
+ n->n.flags |= KRF_SYNC_ERROR;
+ else
+ n->n.flags &= ~KRF_SYNC_ERROR;
+}
+
+
+#define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0)
+
+static void
+nl_parse_route(struct nlmsghdr *h, int scan)
+{
+ struct krt_proto *p;
+ struct rtmsg *i;
+ struct rtattr *a[RTA_CACHEINFO+1];
+ int new = h->nlmsg_type == RTM_NEWROUTE;
+
+ ip_addr dst = IPA_NONE;
+ u32 oif = ~0;
+ int src;
+
+ if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(RTM_RTA(i), a, sizeof(a)))
+ return;
+ if (i->rtm_family != BIRD_AF)
+ return;
+ if ((a[RTA_DST] && RTA_PAYLOAD(a[RTA_DST]) != sizeof(ip_addr)) ||
+#ifdef IPV6
+ (a[RTA_IIF] && RTA_PAYLOAD(a[RTA_IIF]) != 4) ||
+#endif
+ (a[RTA_OIF] && RTA_PAYLOAD(a[RTA_OIF]) != 4) ||
+ (a[RTA_GATEWAY] && RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)) ||
+ (a[RTA_PRIORITY] && RTA_PAYLOAD(a[RTA_PRIORITY]) != 4) ||
+ (a[RTA_PREFSRC] && RTA_PAYLOAD(a[RTA_PREFSRC]) != sizeof(ip_addr)) ||
+ (a[RTA_FLOW] && RTA_PAYLOAD(a[RTA_OIF]) != 4))
+ {
+ log(L_ERR "KRT: Malformed message received");
+ return;
+ }
+
+ if (a[RTA_DST])
+ {
+ memcpy(&dst, RTA_DATA(a[RTA_DST]), sizeof(dst));
+ ipa_ntoh(dst);
+ }
+
+ if (a[RTA_OIF])
+ memcpy(&oif, RTA_DATA(a[RTA_OIF]), sizeof(oif));
+
+ p = nl_table_map[i->rtm_table]; /* Do we know this table? */
+ DBG("KRT: Got %I/%d, type=%d, oif=%d, table=%d, prid=%d, proto=%s\n", dst, i->rtm_dst_len, i->rtm_type, oif, i->rtm_table, i->rtm_protocol, p ? p->p.name : "(none)");
+ if (!p)
+ SKIP("unknown table %d\n", i->rtm_table);
+
+
+#ifdef IPV6
+ if (a[RTA_IIF])
+ SKIP("IIF set\n");
+#else
+ if (i->rtm_tos != 0) /* We don't support TOS */
+ SKIP("TOS %02x\n", i->rtm_tos);
+#endif
+
+ if (scan && !new)
+ SKIP("RTM_DELROUTE in scan\n");
+
+ int c = ipa_classify_net(dst);
+ if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK))
+ SKIP("strange class/scope\n");
+
+ // ignore rtm_scope, it is not a real scope
+ // if (i->rtm_scope != RT_SCOPE_UNIVERSE)
+ // SKIP("scope %u\n", i->rtm_scope);
+
+ switch (i->rtm_protocol)
+ {
+ case RTPROT_UNSPEC:
+ SKIP("proto unspec\n");
+
+ case RTPROT_REDIRECT:
+ src = KRT_SRC_REDIRECT;
+ break;
+
+ case RTPROT_KERNEL:
+ src = KRT_SRC_KERNEL;
+ return;
+
+ case RTPROT_BIRD:
+ if (!scan)
+ SKIP("echo\n");
+ src = KRT_SRC_BIRD;
+ break;
+
+ case RTPROT_BOOT:
+ default:
+ src = KRT_SRC_ALIEN;
+ }
+
+ net *net = net_get(p->p.table, dst, i->rtm_dst_len);
+
+ rta ra = {
+ .proto = &p->p,
+ .source = RTS_INHERIT,
+ .scope = SCOPE_UNIVERSE,
+ .cast = RTC_UNICAST
+ };
+
+ switch (i->rtm_type)
+ {
+ case RTN_UNICAST:
+
+ if (a[RTA_MULTIPATH])
+ {
+ ra.dest = RTD_MULTIPATH;
+ ra.nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH]);
+ if (!ra.nexthops)
+ {
+ log(L_ERR "KRT: Received strange multipath route %I/%d",
+ net->n.prefix, net->n.pxlen);
+ return;
+ }
+
+ break;
+ }
+
+ ra.iface = if_find_by_index(oif);
+ if (!ra.iface)
+ {
+ log(L_ERR "KRT: Received route %I/%d with unknown ifindex %u",
+ net->n.prefix, net->n.pxlen, oif);
+ return;
+ }
+
+ if (a[RTA_GATEWAY])
+ {
+ neighbor *ng;
+ ra.dest = RTD_ROUTER;
+ memcpy(&ra.gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ra.gw));
+ ipa_ntoh(ra.gw);
+
+ /* Silently skip strange 6to4 routes */
+ if (ipa_in_net(ra.gw, IPA_NONE, 96))
+ return;
+
+ ng = neigh_find2(&p->p, &ra.gw, ra.iface,
+ (i->rtm_flags & RTNH_F_ONLINK) ? NEF_ONLINK : 0);
+ if (!ng || (ng->scope == SCOPE_HOST))
+ {
+ log(L_ERR "KRT: Received route %I/%d with strange next-hop %I",
+ net->n.prefix, net->n.pxlen, ra.gw);
+ return;
+ }
+ }
+ else
+ {
+ ra.dest = RTD_DEVICE;
+
+ /*
+ * In Linux IPv6, 'native' device routes have proto
+ * RTPROT_BOOT and not RTPROT_KERNEL (which they have in
+ * IPv4 and which is expected). We cannot distinguish
+ * 'native' and user defined device routes, so we ignore all
+ * such device routes and for consistency, we have the same
+ * behavior in IPv4. Anyway, users should use RTPROT_STATIC
+ * for their 'alien' routes.
+ */
+
+ if (i->rtm_protocol == RTPROT_BOOT)
+ src = KRT_SRC_KERNEL;
+ }
+
+ break;
+ case RTN_BLACKHOLE:
+ ra.dest = RTD_BLACKHOLE;
+ break;
+ case RTN_UNREACHABLE:
+ ra.dest = RTD_UNREACHABLE;
+ break;
+ case RTN_PROHIBIT:
+ ra.dest = RTD_PROHIBIT;
+ break;
+ /* FIXME: What about RTN_THROW? */
+ default:
+ SKIP("type %d\n", i->rtm_type);
+ return;
+ }
+
+ rte *e = rte_get_temp(&ra);
+ e->net = net;
+ e->u.krt.src = src;
+ e->u.krt.proto = i->rtm_protocol;
+ e->u.krt.type = i->rtm_type;
+
+ if (a[RTA_PRIORITY])
+ memcpy(&e->u.krt.metric, RTA_DATA(a[RTA_PRIORITY]), sizeof(e->u.krt.metric));
+ else
+ e->u.krt.metric = 0;
+
+ if (a[RTA_PREFSRC])
+ {
+ ip_addr ps;
+ memcpy(&ps, RTA_DATA(a[RTA_PREFSRC]), sizeof(ps));
+ ipa_ntoh(ps);
+
+ ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr));
+ ea->next = ra.eattrs;
+ ra.eattrs = ea;
+ ea->flags = EALF_SORTED;
+ ea->count = 1;
+ ea->attrs[0].id = EA_KRT_PREFSRC;
+ ea->attrs[0].flags = 0;
+ ea->attrs[0].type = EAF_TYPE_IP_ADDRESS;
+ ea->attrs[0].u.ptr = alloca(sizeof(struct adata) + sizeof(ps));
+ ea->attrs[0].u.ptr->length = sizeof(ps);
+ memcpy(ea->attrs[0].u.ptr->data, &ps, sizeof(ps));
+ }
+
+ if (a[RTA_FLOW])
+ {
+ ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr));
+ ea->next = ra.eattrs;
+ ra.eattrs = ea;
+ ea->flags = EALF_SORTED;
+ ea->count = 1;
+ ea->attrs[0].id = EA_KRT_REALM;
+ ea->attrs[0].flags = 0;
+ ea->attrs[0].type = EAF_TYPE_INT;
+ memcpy(&ea->attrs[0].u.data, RTA_DATA(a[RTA_FLOW]), 4);
+ }
+
+ if (scan)
+ krt_got_route(p, e);
+ else
+ krt_got_route_async(p, e, new);
+}
+
+void
+krt_do_scan(struct krt_proto *p UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NULL */
+{
+ struct nlmsghdr *h;
+
+ nl_request_dump(RTM_GETROUTE);
+ while (h = nl_get_scan())
+ if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE)
+ nl_parse_route(h, 1);
+ else
+ log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type);
+}
+
+/*
+ * Asynchronous Netlink interface
+ */
+
+static sock *nl_async_sk; /* BIRD socket for asynchronous notifications */
+static byte *nl_async_rx_buffer; /* Receive buffer */
+
+static void
+nl_async_msg(struct nlmsghdr *h)
+{
+ switch (h->nlmsg_type)
+ {
+ case RTM_NEWROUTE:
+ case RTM_DELROUTE:
+ DBG("KRT: Received async route notification (%d)\n", h->nlmsg_type);
+ nl_parse_route(h, 0);
+ break;
+ case RTM_NEWLINK:
+ case RTM_DELLINK:
+ DBG("KRT: Received async link notification (%d)\n", h->nlmsg_type);
+ nl_parse_link(h, 0);
+ break;
+ case RTM_NEWADDR:
+ case RTM_DELADDR:
+ DBG("KRT: Received async address notification (%d)\n", h->nlmsg_type);
+ nl_parse_addr(h);
+ break;
+ default:
+ DBG("KRT: Received unknown async notification (%d)\n", h->nlmsg_type);
+ }
+}
+
+static int
+nl_async_hook(sock *sk, int size UNUSED)
+{
+ struct iovec iov = { nl_async_rx_buffer, NL_RX_SIZE };
+ struct sockaddr_nl sa;
+ struct msghdr m = { (struct sockaddr *) &sa, sizeof(sa), &iov, 1, NULL, 0, 0 };
+ struct nlmsghdr *h;
+ int x;
+ unsigned int len;
+
+ x = recvmsg(sk->fd, &m, 0);
+ if (x < 0)
+ {
+ if (errno == ENOBUFS)
+ {
+ /*
+ * Netlink reports some packets have been thrown away.
+ * One day we might react to it by asking for route table
+ * scan in near future.
+ */
+ return 1; /* More data are likely to be ready */
+ }
+ else if (errno != EWOULDBLOCK)
+ log(L_ERR "Netlink recvmsg: %m");
+ return 0;
+ }
+ if (sa.nl_pid) /* It isn't from the kernel */
+ {
+ DBG("Non-kernel packet\n");
+ return 1;
+ }
+ h = (void *) nl_async_rx_buffer;
+ len = x;
+ if (m.msg_flags & MSG_TRUNC)
+ {
+ log(L_WARN "Netlink got truncated asynchronous message");
+ return 1;
+ }
+ while (NLMSG_OK(h, len))
+ {
+ nl_async_msg(h);
+ h = NLMSG_NEXT(h, len);
+ }
+ if (len)
+ log(L_WARN "nl_async_hook: Found packet remnant of size %d", len);
+ return 1;
+}
+
+static void
+nl_open_async(void)
+{
+ sock *sk;
+ struct sockaddr_nl sa;
+ int fd;
+ static int nl_open_tried = 0;
+
+ if (nl_open_tried)
+ return;
+ nl_open_tried = 1;
+
+ DBG("KRT: Opening async netlink socket\n");
+
+ fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ if (fd < 0)
+ {
+ log(L_ERR "Unable to open asynchronous rtnetlink socket: %m");
+ return;
+ }
+
+ bzero(&sa, sizeof(sa));
+ sa.nl_family = AF_NETLINK;
+#ifdef IPV6
+ sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV6_IFADDR | RTMGRP_IPV6_ROUTE;
+#else
+ sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV4_ROUTE;
+#endif
+ if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0)
+ {
+ log(L_ERR "Unable to bind asynchronous rtnetlink socket: %m");
+ return;
+ }
+
+ sk = nl_async_sk = sk_new(krt_pool);
+ sk->type = SK_MAGIC;
+ sk->rx_hook = nl_async_hook;
+ sk->fd = fd;
+ if (sk_open(sk))
+ bug("Netlink: sk_open failed");
+
+ if (!nl_async_rx_buffer)
+ nl_async_rx_buffer = xmalloc(NL_RX_SIZE);
+}
+
+/*
+ * Interface to the UNIX krt module
+ */
+
+static u8 nl_cf_table[(NL_NUM_TABLES+7) / 8];
+
+void
+krt_sys_start(struct krt_proto *p, int first)
+{
+ nl_table_map[KRT_CF->sys.table_id] = p;
+ if (first)
+ {
+ nl_open();
+ nl_open_async();
+ }
+}
+
+void
+krt_sys_shutdown(struct krt_proto *p UNUSED, int last UNUSED)
+{
+}
+
+int
+krt_sys_reconfigure(struct krt_proto *p UNUSED, struct krt_config *n, struct krt_config *o)
+{
+ return n->sys.table_id == o->sys.table_id;
+}
+
+
+void
+krt_sys_preconfig(struct config *c UNUSED)
+{
+ bzero(&nl_cf_table, sizeof(nl_cf_table));
+}
+
+void
+krt_sys_postconfig(struct krt_config *x)
+{
+ int id = x->sys.table_id;
+
+ if (nl_cf_table[id/8] & (1 << (id%8)))
+ cf_error("Multiple kernel syncers defined for table #%d", id);
+ nl_cf_table[id/8] |= (1 << (id%8));
+}
+
+void
+krt_sys_init_config(struct krt_config *cf)
+{
+ cf->sys.table_id = RT_TABLE_MAIN;
+}
+
+void
+krt_sys_copy_config(struct krt_config *d, struct krt_config *s)
+{
+ d->sys.table_id = s->sys.table_id;
+}
+
+
+
+void
+kif_sys_start(struct kif_proto *p UNUSED)
+{
+ nl_open();
+ nl_open_async();
+}
+
+void
+kif_sys_shutdown(struct kif_proto *p UNUSED)
+{
+}
projects / thirdparty / bird.git / commitdiff
