2 * Copyright (C) 2017 Hans Dedecker <dedeckeh@gmail.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
19 #include <linux/netlink.h>
20 #include <linux/if_addr.h>
21 #include <linux/neighbour.h>
22 #include <linux/rtnetlink.h>
24 #include <netlink/msg.h>
25 #include <netlink/socket.h>
26 #include <netlink/attr.h>
28 #include <arpa/inet.h>
29 #include <libubox/list.h>
34 struct odhcpd_event ev
;
39 static void handle_rtnl_event(struct odhcpd_event
*ev
);
40 static int cb_rtnl_valid(struct nl_msg
*msg
, void *arg
);
41 static void catch_rtnl_err(struct odhcpd_event
*e
, int error
);
42 static struct nl_sock
*create_socket(int protocol
);
44 static struct nl_sock
*rtnl_socket
= NULL
;
45 struct list_head netevent_handler_list
= LIST_HEAD_INIT(netevent_handler_list
);
46 static struct event_socket rtnl_event
= {
48 .uloop
= {.fd
= - 1, },
50 .handle_error
= catch_rtnl_err
,
51 .recv_msgs
= handle_rtnl_event
,
54 .sock_bufsize
= 133120,
57 int netlink_init(void)
59 rtnl_socket
= create_socket(NETLINK_ROUTE
);
61 syslog(LOG_ERR
, "Unable to open nl socket: %m");
65 rtnl_event
.sock
= create_socket(NETLINK_ROUTE
);
66 if (!rtnl_event
.sock
) {
67 syslog(LOG_ERR
, "Unable to open nl event socket: %m");
71 rtnl_event
.ev
.uloop
.fd
= nl_socket_get_fd(rtnl_event
.sock
);
73 if (nl_socket_set_buffer_size(rtnl_event
.sock
, rtnl_event
.sock_bufsize
, 0))
76 nl_socket_disable_seq_check(rtnl_event
.sock
);
78 nl_socket_modify_cb(rtnl_event
.sock
, NL_CB_VALID
, NL_CB_CUSTOM
,
81 /* Receive IPv4 address, IPv6 address, IPv6 routes and neighbor events */
82 if (nl_socket_add_memberships(rtnl_event
.sock
, RTNLGRP_IPV4_IFADDR
,
83 RTNLGRP_IPV6_IFADDR
, RTNLGRP_IPV6_ROUTE
,
84 RTNLGRP_NEIGH
, RTNLGRP_LINK
, 0))
87 odhcpd_register(&rtnl_event
.ev
);
93 nl_socket_free(rtnl_socket
);
97 if (rtnl_event
.sock
) {
98 nl_socket_free(rtnl_event
.sock
);
99 rtnl_event
.sock
= NULL
;
100 rtnl_event
.ev
.uloop
.fd
= -1;
107 int netlink_add_netevent_handler(struct netevent_handler
*handler
)
112 list_add(&handler
->head
, &netevent_handler_list
);
117 static void call_netevent_handler_list(unsigned long event
, struct netevent_handler_info
*info
)
119 struct netevent_handler
*handler
;
121 list_for_each_entry(handler
, &netevent_handler_list
, head
)
122 handler
->cb(event
, info
);
125 static void handle_rtnl_event(struct odhcpd_event
*e
)
127 struct event_socket
*ev_sock
= container_of(e
, struct event_socket
, ev
);
129 nl_recvmsgs_default(ev_sock
->sock
);
132 static void refresh_iface_addr4(struct netevent_handler_info
*event_info
)
134 struct odhcpd_ipaddr
*addr
= NULL
;
135 struct interface
*iface
= event_info
->iface
;
136 ssize_t len
= netlink_get_interface_addrs(iface
->ifindex
, false, &addr
);
141 bool change
= len
!= (ssize_t
)iface
->addr4_len
;
142 for (ssize_t i
= 0; !change
&& i
< len
; ++i
)
143 if (addr
[i
].addr
.in
.s_addr
!= iface
->addr4
[i
].addr
.in
.s_addr
)
146 event_info
->addrs_old
.addrs
= iface
->addr4
;
147 event_info
->addrs_old
.len
= iface
->addr4_len
;
150 iface
->addr4_len
= len
;
153 call_netevent_handler_list(NETEV_ADDRLIST_CHANGE
, event_info
);
155 free(event_info
->addrs_old
.addrs
);
158 static void refresh_iface_addr6(struct netevent_handler_info
*event_info
)
160 struct odhcpd_ipaddr
*addr
= NULL
;
161 struct interface
*iface
= event_info
->iface
;
162 ssize_t len
= netlink_get_interface_addrs(iface
->ifindex
, true, &addr
);
167 bool change
= len
!= (ssize_t
)iface
->addr6_len
;
168 for (ssize_t i
= 0; !change
&& i
< len
; ++i
)
169 if (!IN6_ARE_ADDR_EQUAL(&addr
[i
].addr
.in6
, &iface
->addr6
[i
].addr
.in6
) ||
170 (addr
[i
].preferred
> 0) != (iface
->addr6
[i
].preferred
> 0) ||
171 addr
[i
].valid
< iface
->addr6
[i
].valid
||
172 addr
[i
].preferred
< iface
->addr6
[i
].preferred
)
175 event_info
->addrs_old
.addrs
= iface
->addr6
;
176 event_info
->addrs_old
.len
= iface
->addr6_len
;
179 iface
->addr6_len
= len
;
182 call_netevent_handler_list(NETEV_ADDR6LIST_CHANGE
, event_info
);
184 free(event_info
->addrs_old
.addrs
);
187 /* Handler for neighbor cache entries from the kernel. This is our source
188 * to learn and unlearn hosts on interfaces. */
189 static int cb_rtnl_valid(struct nl_msg
*msg
, _unused
void *arg
)
191 struct nlmsghdr
*hdr
= nlmsg_hdr(msg
);
192 struct netevent_handler_info event_info
;
194 char ipbuf
[INET6_ADDRSTRLEN
];
196 memset(&event_info
, 0, sizeof(event_info
));
197 switch (hdr
->nlmsg_type
) {
199 struct ifinfomsg
*ifi
= nlmsg_data(hdr
);
200 struct nlattr
*nla
[__IFLA_MAX
];
202 if (!nlmsg_valid_hdr(hdr
, sizeof(*ifi
)) ||
203 ifi
->ifi_family
!= AF_UNSPEC
)
206 nlmsg_parse(hdr
, sizeof(*ifi
), nla
, __IFLA_MAX
- 1, NULL
);
207 if (!nla
[IFLA_IFNAME
])
210 event_info
.iface
= odhcpd_get_interface_by_name(nla_get_string(nla
[IFLA_IFNAME
]));
211 if (!event_info
.iface
)
214 if (event_info
.iface
->ifindex
!= ifi
->ifi_index
) {
215 event_info
.iface
->ifindex
= ifi
->ifi_index
;
216 call_netevent_handler_list(NETEV_IFINDEX_CHANGE
, &event_info
);
225 struct rtmsg
*rtm
= nlmsg_data(hdr
);
226 struct nlattr
*nla
[__RTA_MAX
];
228 if (!nlmsg_valid_hdr(hdr
, sizeof(*rtm
)) ||
229 rtm
->rtm_family
!= AF_INET6
)
232 nlmsg_parse(hdr
, sizeof(*rtm
), nla
, __RTA_MAX
- 1, NULL
);
234 event_info
.rt
.dst_len
= rtm
->rtm_dst_len
;
236 nla_memcpy(&event_info
.rt
.dst
, nla
[RTA_DST
],
237 sizeof(event_info
.rt
.dst
));
240 event_info
.iface
= odhcpd_get_interface_by_index(nla_get_u32(nla
[RTA_OIF
]));
242 if (nla
[RTA_GATEWAY
])
243 nla_memcpy(&event_info
.rt
.gateway
, nla
[RTA_GATEWAY
],
244 sizeof(event_info
.rt
.gateway
));
246 call_netevent_handler_list(add
? NETEV_ROUTE6_ADD
: NETEV_ROUTE6_DEL
,
255 struct ifaddrmsg
*ifa
= nlmsg_data(hdr
);
256 struct nlattr
*nla
[__IFA_MAX
];
258 if (!nlmsg_valid_hdr(hdr
, sizeof(*ifa
)) ||
259 (ifa
->ifa_family
!= AF_INET6
&&
260 ifa
->ifa_family
!= AF_INET
))
263 event_info
.iface
= odhcpd_get_interface_by_index(ifa
->ifa_index
);
264 if (!event_info
.iface
)
267 nlmsg_parse(hdr
, sizeof(*ifa
), nla
, __IFA_MAX
- 1, NULL
);
269 if (ifa
->ifa_family
== AF_INET6
) {
270 if (!nla
[IFA_ADDRESS
])
273 nla_memcpy(&event_info
.addr
, nla
[IFA_ADDRESS
], sizeof(event_info
.addr
));
275 if (IN6_IS_ADDR_LINKLOCAL(&event_info
.addr
) ||
276 IN6_IS_ADDR_MULTICAST(&event_info
.addr
))
279 inet_ntop(AF_INET6
, &event_info
.addr
, ipbuf
, sizeof(ipbuf
));
280 syslog(LOG_DEBUG
, "Netlink %s %s%%%s", add
? "newaddr" : "deladdr",
281 ipbuf
, event_info
.iface
->ifname
);
283 call_netevent_handler_list(add
? NETEV_ADDR6_ADD
: NETEV_ADDR6_DEL
,
286 refresh_iface_addr6(&event_info
);
291 nla_memcpy(&event_info
.addr
, nla
[IFA_LOCAL
], sizeof(event_info
.addr
));
293 inet_ntop(AF_INET
, &event_info
.addr
, ipbuf
, sizeof(ipbuf
));
294 syslog(LOG_DEBUG
, "Netlink %s %s%%%s", add
? "newaddr" : "deladdr",
295 ipbuf
, event_info
.iface
->ifname
);
297 call_netevent_handler_list(add
? NETEV_ADDR_ADD
: NETEV_ADDR_DEL
,
300 refresh_iface_addr4(&event_info
);
309 struct ndmsg
*ndm
= nlmsg_data(hdr
);
310 struct nlattr
*nla
[__NDA_MAX
];
312 if (!nlmsg_valid_hdr(hdr
, sizeof(*ndm
)) ||
313 ndm
->ndm_family
!= AF_INET6
)
316 event_info
.iface
= odhcpd_get_interface_by_index(ndm
->ndm_ifindex
);
317 if (!event_info
.iface
)
320 nlmsg_parse(hdr
, sizeof(*ndm
), nla
, __NDA_MAX
- 1, NULL
);
324 nla_memcpy(&event_info
.neigh
.dst
, nla
[NDA_DST
], sizeof(event_info
.neigh
.dst
));
326 if (IN6_IS_ADDR_LINKLOCAL(&event_info
.neigh
.dst
) ||
327 IN6_IS_ADDR_MULTICAST(&event_info
.neigh
.dst
))
330 inet_ntop(AF_INET6
, &event_info
.neigh
.dst
, ipbuf
, sizeof(ipbuf
));
331 syslog(LOG_DEBUG
, "Netlink %s %s%%%s", true ? "newneigh" : "delneigh",
332 ipbuf
, event_info
.iface
->ifname
);
334 event_info
.neigh
.state
= ndm
->ndm_state
;
335 event_info
.neigh
.flags
= ndm
->ndm_flags
;
337 call_netevent_handler_list(add
? NETEV_NEIGH6_ADD
: NETEV_NEIGH6_DEL
,
349 static void catch_rtnl_err(struct odhcpd_event
*e
, int error
)
351 struct event_socket
*ev_sock
= container_of(e
, struct event_socket
, ev
);
353 if (error
!= ENOBUFS
)
356 /* Double netlink event buffer size */
357 ev_sock
->sock_bufsize
*= 2;
359 if (nl_socket_set_buffer_size(ev_sock
->sock
, ev_sock
->sock_bufsize
, 0))
362 netlink_dump_addr_table(true);
366 odhcpd_deregister(e
);
369 static struct nl_sock
*create_socket(int protocol
)
371 struct nl_sock
*nl_sock
;
373 nl_sock
= nl_socket_alloc();
377 if (nl_connect(nl_sock
, protocol
) < 0)
384 nl_socket_free(nl_sock
);
393 struct odhcpd_ipaddr
**addrs
;
399 static int cb_valid_handler(struct nl_msg
*msg
, void *arg
)
401 struct addr_info
*ctxt
= (struct addr_info
*)arg
;
402 struct odhcpd_ipaddr
*addrs
= *(ctxt
->addrs
);
403 struct nlmsghdr
*hdr
= nlmsg_hdr(msg
);
404 struct ifaddrmsg
*ifa
;
405 struct nlattr
*nla
[__IFA_MAX
], *nla_addr
= NULL
;
407 if (hdr
->nlmsg_type
!= RTM_NEWADDR
)
410 ifa
= NLMSG_DATA(hdr
);
411 if (ifa
->ifa_scope
!= RT_SCOPE_UNIVERSE
||
412 (ctxt
->af
!= ifa
->ifa_family
) ||
413 (ctxt
->ifindex
&& ifa
->ifa_index
!= (unsigned)ctxt
->ifindex
))
416 nlmsg_parse(hdr
, sizeof(*ifa
), nla
, __IFA_MAX
- 1, NULL
);
418 switch (ifa
->ifa_family
) {
420 if (nla
[IFA_ADDRESS
])
421 nla_addr
= nla
[IFA_ADDRESS
];
426 nla_addr
= nla
[IFA_LOCAL
];
435 addrs
= realloc(addrs
, sizeof(*addrs
)*(ctxt
->ret
+ 1));
439 memset(&addrs
[ctxt
->ret
], 0, sizeof(addrs
[ctxt
->ret
]));
440 addrs
[ctxt
->ret
].prefix
= ifa
->ifa_prefixlen
;
442 nla_memcpy(&addrs
[ctxt
->ret
].addr
, nla_addr
,
443 sizeof(addrs
[ctxt
->ret
].addr
));
445 if (nla
[IFA_BROADCAST
])
446 nla_memcpy(&addrs
[ctxt
->ret
].broadcast
, nla
[IFA_BROADCAST
],
447 sizeof(addrs
[ctxt
->ret
].broadcast
));
449 if (nla
[IFA_CACHEINFO
]) {
450 struct ifa_cacheinfo
*ifc
= nla_data(nla
[IFA_CACHEINFO
]);
452 addrs
[ctxt
->ret
].preferred
= ifc
->ifa_prefered
;
453 addrs
[ctxt
->ret
].valid
= ifc
->ifa_valid
;
456 if (ifa
->ifa_flags
& IFA_F_DEPRECATED
)
457 addrs
[ctxt
->ret
].preferred
= 0;
460 *(ctxt
->addrs
) = addrs
;
466 static int cb_finish_handler(_unused
struct nl_msg
*msg
, void *arg
)
468 struct addr_info
*ctxt
= (struct addr_info
*)arg
;
476 static int cb_error_handler(_unused
struct sockaddr_nl
*nla
, struct nlmsgerr
*err
,
479 struct addr_info
*ctxt
= (struct addr_info
*)arg
;
482 ctxt
->ret
= err
->error
;
488 static int prefix_cmp(const void *va
, const void *vb
)
490 const struct odhcpd_ipaddr
*a
= va
, *b
= vb
;
493 if (a
->prefix
== b
->prefix
) {
494 ret
= (ntohl(a
->addr
.in
.s_addr
) < ntohl(b
->addr
.in
.s_addr
)) ? 1 :
495 (ntohl(a
->addr
.in
.s_addr
) > ntohl(b
->addr
.in
.s_addr
)) ? -1 : 0;
497 ret
= a
->prefix
< b
->prefix
? 1 : -1;
503 /* compare IPv6 prefixes */
504 static int prefix6_cmp(const void *va
, const void *vb
)
506 const struct odhcpd_ipaddr
*a
= va
, *b
= vb
;
507 uint32_t a_pref
= IN6_IS_ADDR_ULA(&a
->addr
.in6
) ? 1 : a
->preferred
;
508 uint32_t b_pref
= IN6_IS_ADDR_ULA(&b
->addr
.in6
) ? 1 : b
->preferred
;
509 return (a_pref
< b_pref
) ? 1 : (a_pref
> b_pref
) ? -1 : 0;
513 /* Detect an IPV6-address currently assigned to the given interface */
514 ssize_t
netlink_get_interface_addrs(int ifindex
, bool v6
, struct odhcpd_ipaddr
**addrs
)
517 struct ifaddrmsg ifa
= {
518 .ifa_family
= v6
? AF_INET6
: AF_INET
,
522 .ifa_index
= ifindex
, };
523 struct nl_cb
*cb
= nl_cb_alloc(NL_CB_DEFAULT
);
524 struct addr_info ctxt
= {
526 .af
= v6
? AF_INET6
: AF_INET
,
537 msg
= nlmsg_alloc_simple(RTM_GETADDR
, NLM_F_REQUEST
| NLM_F_DUMP
);
544 nlmsg_append(msg
, &ifa
, sizeof(ifa
), 0);
546 nl_cb_set(cb
, NL_CB_VALID
, NL_CB_CUSTOM
, cb_valid_handler
, &ctxt
);
547 nl_cb_set(cb
, NL_CB_FINISH
, NL_CB_CUSTOM
, cb_finish_handler
, &ctxt
);
548 nl_cb_err(cb
, NL_CB_CUSTOM
, cb_error_handler
, &ctxt
);
550 nl_send_auto_complete(rtnl_socket
, msg
);
551 while (ctxt
.pending
> 0)
552 nl_recvmsgs(rtnl_socket
, cb
);
559 time_t now
= odhcpd_time();
560 struct odhcpd_ipaddr
*addr
= *addrs
;
562 qsort(addr
, ctxt
.ret
, sizeof(*addr
), v6
? prefix6_cmp
: prefix_cmp
);
564 for (ssize_t i
= 0; i
< ctxt
.ret
; ++i
) {
565 if (addr
[i
].preferred
< UINT32_MAX
- now
)
566 addr
[i
].preferred
+= now
;
568 if (addr
[i
].valid
< UINT32_MAX
- now
)
569 addr
[i
].valid
+= now
;
579 int netlink_setup_route(const struct in6_addr
*addr
, const int prefixlen
,
580 const int ifindex
, const struct in6_addr
*gw
,
581 const uint32_t metric
, const bool add
)
585 .rtm_family
= AF_INET6
,
586 .rtm_dst_len
= prefixlen
,
588 .rtm_table
= RT_TABLE_MAIN
,
589 .rtm_protocol
= (add
? RTPROT_STATIC
: RTPROT_UNSPEC
),
590 .rtm_scope
= (add
? (gw
? RT_SCOPE_UNIVERSE
: RT_SCOPE_LINK
) : RT_SCOPE_NOWHERE
),
591 .rtm_type
= (add
? RTN_UNICAST
: RTN_UNSPEC
),
595 msg
= nlmsg_alloc_simple(add
? RTM_NEWROUTE
: RTM_DELROUTE
,
596 add
? NLM_F_CREATE
| NLM_F_REPLACE
: 0);
600 nlmsg_append(msg
, &rtm
, sizeof(rtm
), 0);
602 nla_put(msg
, RTA_DST
, sizeof(*addr
), addr
);
603 nla_put_u32(msg
, RTA_OIF
, ifindex
);
604 nla_put_u32(msg
, RTA_PRIORITY
, metric
);
607 nla_put(msg
, RTA_GATEWAY
, sizeof(*gw
), gw
);
609 ret
= nl_send_auto_complete(rtnl_socket
, msg
);
615 return nl_wait_for_ack(rtnl_socket
);
619 int netlink_setup_proxy_neigh(const struct in6_addr
*addr
,
620 const int ifindex
, const bool add
)
624 .ndm_family
= AF_INET6
,
625 .ndm_flags
= NTF_PROXY
,
626 .ndm_ifindex
= ifindex
,
628 int ret
= 0, flags
= NLM_F_REQUEST
;
631 flags
|= NLM_F_REPLACE
| NLM_F_CREATE
;
633 msg
= nlmsg_alloc_simple(add
? RTM_NEWNEIGH
: RTM_DELNEIGH
, flags
);
637 nlmsg_append(msg
, &ndm
, sizeof(ndm
), 0);
639 nla_put(msg
, NDA_DST
, sizeof(*addr
), addr
);
641 ret
= nl_send_auto_complete(rtnl_socket
, msg
);
647 return nl_wait_for_ack(rtnl_socket
);
651 int netlink_setup_addr(struct odhcpd_ipaddr
*addr
,
652 const int ifindex
, const bool v6
, const bool add
)
655 struct ifaddrmsg ifa
= {
656 .ifa_family
= v6
? AF_INET6
: AF_INET
,
657 .ifa_prefixlen
= addr
->prefix
,
660 .ifa_index
= ifindex
, };
661 int ret
= 0, flags
= NLM_F_REQUEST
;
664 flags
|= NLM_F_REPLACE
| NLM_F_CREATE
;
666 msg
= nlmsg_alloc_simple(add
? RTM_NEWADDR
: RTM_DELADDR
, 0);
670 nlmsg_append(msg
, &ifa
, sizeof(ifa
), flags
);
671 nla_put(msg
, IFA_LOCAL
, v6
? 16 : 4, &addr
->addr
);
673 struct ifa_cacheinfo cinfo
= { .ifa_prefered
= 0xffffffffU
,
674 .ifa_valid
= 0xffffffffU
,
677 time_t now
= odhcpd_time();
679 if (addr
->preferred
) {
680 int64_t preferred
= addr
->preferred
- now
;
683 else if (preferred
> UINT32_MAX
)
684 preferred
= UINT32_MAX
;
686 cinfo
.ifa_prefered
= preferred
;
690 int64_t valid
= addr
->valid
- now
;
695 else if (valid
> UINT32_MAX
)
698 cinfo
.ifa_valid
= valid
;
701 nla_put(msg
, IFA_CACHEINFO
, sizeof(cinfo
), &cinfo
);
703 nla_put_u32(msg
, IFA_FLAGS
, IFA_F_NOPREFIXROUTE
);
705 if (addr
->broadcast
.s_addr
)
706 nla_put_u32(msg
, IFA_BROADCAST
, addr
->broadcast
.s_addr
);
709 ret
= nl_send_auto_complete(rtnl_socket
, msg
);
715 return nl_wait_for_ack(rtnl_socket
);
718 void netlink_dump_neigh_table(const bool proxy
)
722 .ndm_family
= AF_INET6
,
723 .ndm_flags
= proxy
? NTF_PROXY
: 0,
726 msg
= nlmsg_alloc_simple(RTM_GETNEIGH
, NLM_F_REQUEST
| NLM_F_DUMP
);
730 nlmsg_append(msg
, &ndm
, sizeof(ndm
), 0);
732 nl_send_auto_complete(rtnl_event
.sock
, msg
);
737 void netlink_dump_addr_table(const bool v6
)
740 struct ifaddrmsg ifa
= {
741 .ifa_family
= v6
? AF_INET6
: AF_INET
,
744 msg
= nlmsg_alloc_simple(RTM_GETADDR
, NLM_F_REQUEST
| NLM_F_DUMP
);
748 nlmsg_append(msg
, &ifa
, sizeof(ifa
), 0);
750 nl_send_auto_complete(rtnl_event
.sock
, msg
);