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2fb975da TT |
1 | /* NHRP netlink/neighbor table arpd code |
2 | * Copyright (c) 2014-2016 Timo Teräs | |
3 | * | |
4 | * This file is free software: you may copy, redistribute and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation, either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | */ | |
9 | ||
10 | #include <fcntl.h> | |
11 | #include <net/if.h> | |
12 | #include <netinet/if_ether.h> | |
13 | #include <linux/netlink.h> | |
14 | #include <linux/neighbour.h> | |
15 | #include <linux/netfilter/nfnetlink_log.h> | |
16 | ||
17 | #include "thread.h" | |
18 | #include "nhrpd.h" | |
19 | #include "netlink.h" | |
20 | #include "znl.h" | |
21 | ||
22 | int netlink_req_fd = -1; | |
23 | int netlink_nflog_group; | |
24 | static int netlink_log_fd = -1; | |
25 | static struct thread *netlink_log_thread; | |
26 | static int netlink_listen_fd = -1; | |
27 | ||
28 | typedef void (*netlink_dispatch_f)(struct nlmsghdr *msg, struct zbuf *zb); | |
29 | ||
996c9314 LB |
30 | void netlink_update_binding(struct interface *ifp, union sockunion *proto, |
31 | union sockunion *nbma) | |
2fb975da TT |
32 | { |
33 | struct nlmsghdr *n; | |
34 | struct ndmsg *ndm; | |
35 | struct zbuf *zb = zbuf_alloc(512); | |
36 | ||
996c9314 LB |
37 | n = znl_nlmsg_push(zb, nbma ? RTM_NEWNEIGH : RTM_DELNEIGH, |
38 | NLM_F_REQUEST | NLM_F_REPLACE | NLM_F_CREATE); | |
2fb975da | 39 | ndm = znl_push(zb, sizeof(*ndm)); |
996c9314 | 40 | *ndm = (struct ndmsg){ |
2fb975da TT |
41 | .ndm_family = sockunion_family(proto), |
42 | .ndm_ifindex = ifp->ifindex, | |
43 | .ndm_type = RTN_UNICAST, | |
44 | .ndm_state = nbma ? NUD_REACHABLE : NUD_FAILED, | |
45 | }; | |
996c9314 LB |
46 | znl_rta_push(zb, NDA_DST, sockunion_get_addr(proto), |
47 | family2addrsize(sockunion_family(proto))); | |
2fb975da | 48 | if (nbma) |
996c9314 LB |
49 | znl_rta_push(zb, NDA_LLADDR, sockunion_get_addr(nbma), |
50 | family2addrsize(sockunion_family(nbma))); | |
2fb975da TT |
51 | znl_nlmsg_complete(zb, n); |
52 | zbuf_send(zb, netlink_req_fd); | |
53 | zbuf_recv(zb, netlink_req_fd); | |
54 | zbuf_free(zb); | |
55 | } | |
56 | ||
57 | static void netlink_neigh_msg(struct nlmsghdr *msg, struct zbuf *zb) | |
58 | { | |
59 | struct ndmsg *ndm; | |
60 | struct rtattr *rta; | |
61 | struct nhrp_cache *c; | |
62 | struct interface *ifp; | |
63 | struct zbuf payload; | |
64 | union sockunion addr; | |
65 | size_t len; | |
66 | char buf[SU_ADDRSTRLEN]; | |
67 | int state; | |
68 | ||
69 | ndm = znl_pull(zb, sizeof(*ndm)); | |
996c9314 LB |
70 | if (!ndm) |
71 | return; | |
2fb975da TT |
72 | |
73 | sockunion_family(&addr) = AF_UNSPEC; | |
74 | while ((rta = znl_rta_pull(zb, &payload)) != NULL) { | |
75 | len = zbuf_used(&payload); | |
76 | switch (rta->rta_type) { | |
77 | case NDA_DST: | |
996c9314 LB |
78 | sockunion_set(&addr, ndm->ndm_family, |
79 | zbuf_pulln(&payload, len), len); | |
2fb975da TT |
80 | break; |
81 | } | |
82 | } | |
83 | ||
7e2b7603 | 84 | ifp = if_lookup_by_index(ndm->ndm_ifindex, VRF_DEFAULT); |
2fb975da TT |
85 | if (!ifp || sockunion_family(&addr) == AF_UNSPEC) |
86 | return; | |
87 | ||
88 | c = nhrp_cache_get(ifp, &addr, 0); | |
89 | if (!c) | |
90 | return; | |
91 | ||
92 | if (msg->nlmsg_type == RTM_GETNEIGH) { | |
93 | debugf(NHRP_DEBUG_KERNEL, "Netlink: who-has %s dev %s", | |
996c9314 | 94 | sockunion2str(&addr, buf, sizeof buf), ifp->name); |
2fb975da TT |
95 | |
96 | if (c->cur.type >= NHRP_CACHE_CACHED) { | |
97 | nhrp_cache_set_used(c, 1); | |
996c9314 LB |
98 | netlink_update_binding(ifp, &addr, |
99 | &c->cur.peer->vc->remote.nbma); | |
2fb975da TT |
100 | } |
101 | } else { | |
102 | debugf(NHRP_DEBUG_KERNEL, "Netlink: update %s dev %s nud %x", | |
996c9314 LB |
103 | sockunion2str(&addr, buf, sizeof buf), ifp->name, |
104 | ndm->ndm_state); | |
2fb975da | 105 | |
996c9314 LB |
106 | state = (msg->nlmsg_type == RTM_NEWNEIGH) ? ndm->ndm_state |
107 | : NUD_FAILED; | |
2fb975da TT |
108 | nhrp_cache_set_used(c, state == NUD_REACHABLE); |
109 | } | |
110 | } | |
111 | ||
112 | static int netlink_route_recv(struct thread *t) | |
113 | { | |
114 | uint8_t buf[ZNL_BUFFER_SIZE]; | |
115 | int fd = THREAD_FD(t); | |
116 | struct zbuf payload, zb; | |
117 | struct nlmsghdr *n; | |
118 | ||
119 | zbuf_init(&zb, buf, sizeof(buf), 0); | |
120 | while (zbuf_recv(&zb, fd) > 0) { | |
121 | while ((n = znl_nlmsg_pull(&zb, &payload)) != 0) { | |
996c9314 LB |
122 | debugf(NHRP_DEBUG_KERNEL, |
123 | "Netlink: Received msg_type %u, msg_flags %u", | |
124 | n->nlmsg_type, n->nlmsg_flags); | |
2fb975da TT |
125 | switch (n->nlmsg_type) { |
126 | case RTM_GETNEIGH: | |
127 | case RTM_NEWNEIGH: | |
128 | case RTM_DELNEIGH: | |
129 | netlink_neigh_msg(n, &payload); | |
130 | break; | |
131 | } | |
132 | } | |
133 | } | |
134 | ||
ffa2c898 | 135 | thread_add_read(master, netlink_route_recv, 0, fd, NULL); |
2fb975da TT |
136 | |
137 | return 0; | |
138 | } | |
139 | ||
140 | static void netlink_log_register(int fd, int group) | |
141 | { | |
142 | struct nlmsghdr *n; | |
143 | struct nfgenmsg *nf; | |
144 | struct nfulnl_msg_config_cmd cmd; | |
145 | struct zbuf *zb = zbuf_alloc(512); | |
146 | ||
996c9314 LB |
147 | n = znl_nlmsg_push(zb, (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG, |
148 | NLM_F_REQUEST | NLM_F_ACK); | |
2fb975da | 149 | nf = znl_push(zb, sizeof(*nf)); |
996c9314 | 150 | *nf = (struct nfgenmsg){ |
2fb975da TT |
151 | .nfgen_family = AF_UNSPEC, |
152 | .version = NFNETLINK_V0, | |
153 | .res_id = htons(group), | |
154 | }; | |
155 | cmd.command = NFULNL_CFG_CMD_BIND; | |
156 | znl_rta_push(zb, NFULA_CFG_CMD, &cmd, sizeof(cmd)); | |
157 | znl_nlmsg_complete(zb, n); | |
158 | ||
159 | zbuf_send(zb, fd); | |
160 | zbuf_free(zb); | |
161 | } | |
162 | ||
163 | static void netlink_log_indication(struct nlmsghdr *msg, struct zbuf *zb) | |
164 | { | |
165 | struct nfgenmsg *nf; | |
166 | struct rtattr *rta; | |
167 | struct zbuf rtapl, pktpl; | |
168 | struct interface *ifp; | |
169 | struct nfulnl_msg_packet_hdr *pkthdr = NULL; | |
170 | uint32_t *in_ndx = NULL; | |
171 | ||
172 | nf = znl_pull(zb, sizeof(*nf)); | |
996c9314 LB |
173 | if (!nf) |
174 | return; | |
2fb975da TT |
175 | |
176 | memset(&pktpl, 0, sizeof(pktpl)); | |
177 | while ((rta = znl_rta_pull(zb, &rtapl)) != NULL) { | |
178 | switch (rta->rta_type) { | |
179 | case NFULA_PACKET_HDR: | |
180 | pkthdr = znl_pull(&rtapl, sizeof(*pkthdr)); | |
181 | break; | |
182 | case NFULA_IFINDEX_INDEV: | |
183 | in_ndx = znl_pull(&rtapl, sizeof(*in_ndx)); | |
184 | break; | |
185 | case NFULA_PAYLOAD: | |
186 | pktpl = rtapl; | |
187 | break; | |
996c9314 LB |
188 | /* NFULA_HWHDR exists and is supposed to contain source |
189 | * hardware address. However, for ip_gre it seems to be | |
190 | * the nexthop destination address if the packet matches | |
191 | * route. */ | |
2fb975da TT |
192 | } |
193 | } | |
194 | ||
195 | if (!pkthdr || !in_ndx || !zbuf_used(&pktpl)) | |
196 | return; | |
197 | ||
7e2b7603 | 198 | ifp = if_lookup_by_index(htonl(*in_ndx), VRF_DEFAULT); |
2fb975da TT |
199 | if (!ifp) |
200 | return; | |
201 | ||
202 | nhrp_peer_send_indication(ifp, htons(pkthdr->hw_protocol), &pktpl); | |
203 | } | |
204 | ||
205 | static int netlink_log_recv(struct thread *t) | |
206 | { | |
207 | uint8_t buf[ZNL_BUFFER_SIZE]; | |
208 | int fd = THREAD_FD(t); | |
209 | struct zbuf payload, zb; | |
210 | struct nlmsghdr *n; | |
211 | ||
212 | netlink_log_thread = NULL; | |
213 | ||
214 | zbuf_init(&zb, buf, sizeof(buf), 0); | |
215 | while (zbuf_recv(&zb, fd) > 0) { | |
216 | while ((n = znl_nlmsg_pull(&zb, &payload)) != 0) { | |
996c9314 LB |
217 | debugf(NHRP_DEBUG_KERNEL, |
218 | "Netlink-log: Received msg_type %u, msg_flags %u", | |
219 | n->nlmsg_type, n->nlmsg_flags); | |
2fb975da | 220 | switch (n->nlmsg_type) { |
996c9314 | 221 | case (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_PACKET: |
2fb975da TT |
222 | netlink_log_indication(n, &payload); |
223 | break; | |
224 | } | |
225 | } | |
226 | } | |
227 | ||
ffa2c898 QY |
228 | thread_add_read(master, netlink_log_recv, 0, netlink_log_fd, |
229 | &netlink_log_thread); | |
2fb975da TT |
230 | |
231 | return 0; | |
232 | } | |
233 | ||
234 | void netlink_set_nflog_group(int nlgroup) | |
235 | { | |
236 | if (netlink_log_fd >= 0) { | |
237 | THREAD_OFF(netlink_log_thread); | |
238 | close(netlink_log_fd); | |
239 | netlink_log_fd = -1; | |
240 | } | |
241 | netlink_nflog_group = nlgroup; | |
242 | if (nlgroup) { | |
996c9314 | 243 | netlink_log_fd = znl_open(NETLINK_NETFILTER, 0); |
6c8ca260 JB |
244 | if (netlink_log_fd < 0) |
245 | return; | |
246 | ||
2fb975da | 247 | netlink_log_register(netlink_log_fd, nlgroup); |
ffa2c898 QY |
248 | thread_add_read(master, netlink_log_recv, 0, netlink_log_fd, |
249 | &netlink_log_thread); | |
2fb975da TT |
250 | } |
251 | } | |
252 | ||
6c8ca260 | 253 | void netlink_init(void) |
2fb975da TT |
254 | { |
255 | netlink_req_fd = znl_open(NETLINK_ROUTE, 0); | |
6c8ca260 JB |
256 | if (netlink_req_fd < 0) |
257 | return; | |
258 | ||
2fb975da | 259 | netlink_listen_fd = znl_open(NETLINK_ROUTE, RTMGRP_NEIGH); |
6c8ca260 JB |
260 | if (netlink_listen_fd < 0) |
261 | return; | |
262 | ||
996c9314 | 263 | thread_add_read(master, netlink_route_recv, 0, netlink_listen_fd, NULL); |
2fb975da TT |
264 | } |
265 | ||
266 | int netlink_configure_arp(unsigned int ifindex, int pf) | |
267 | { | |
268 | struct nlmsghdr *n; | |
269 | struct ndtmsg *ndtm; | |
270 | struct rtattr *rta; | |
271 | struct zbuf *zb = zbuf_alloc(512); | |
272 | int r; | |
273 | ||
274 | n = znl_nlmsg_push(zb, RTM_SETNEIGHTBL, NLM_F_REQUEST | NLM_F_REPLACE); | |
275 | ndtm = znl_push(zb, sizeof(*ndtm)); | |
996c9314 | 276 | *ndtm = (struct ndtmsg){ |
2fb975da TT |
277 | .ndtm_family = pf, |
278 | }; | |
279 | ||
996c9314 LB |
280 | znl_rta_push(zb, NDTA_NAME, pf == AF_INET ? "arp_cache" : "ndisc_cache", |
281 | 10); | |
2fb975da TT |
282 | |
283 | rta = znl_rta_nested_push(zb, NDTA_PARMS); | |
284 | znl_rta_push_u32(zb, NDTPA_IFINDEX, ifindex); | |
285 | znl_rta_push_u32(zb, NDTPA_APP_PROBES, 1); | |
286 | znl_rta_push_u32(zb, NDTPA_MCAST_PROBES, 0); | |
287 | znl_rta_push_u32(zb, NDTPA_UCAST_PROBES, 0); | |
288 | znl_rta_nested_complete(zb, rta); | |
289 | ||
290 | znl_nlmsg_complete(zb, n); | |
291 | r = zbuf_send(zb, netlink_req_fd); | |
292 | zbuf_recv(zb, netlink_req_fd); | |
293 | zbuf_free(zb); | |
294 | ||
295 | return r; | |
296 | } |