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