2 * Code for encoding/decoding FPM messages that are in netlink format.
4 * Copyright (C) 1997, 98, 99 Kunihiro Ishiguro
5 * Copyright (C) 2012 by Open Source Routing.
6 * Copyright (C) 2012 by Internet Systems Consortium, Inc. ("ISC")
8 * This file is part of GNU Zebra.
10 * GNU Zebra is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2, or (at your option) any
15 * GNU Zebra is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; see the file COPYING; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
34 #include "zebra/zserv.h"
35 #include "zebra/zebra_ns.h"
36 #include "zebra/zebra_vrf.h"
37 #include "zebra/kernel_netlink.h"
38 #include "zebra/rt_netlink.h"
41 #include "zebra/zebra_fpm_private.h"
46 * Returns string representation of an address of the given AF.
48 static inline const char *addr_to_a(u_char af
, void *addr
)
51 return "<No address>";
56 return inet_ntoa(*((struct in_addr
*)addr
));
59 return inet6_ntoa(*((struct in6_addr
*)addr
));
62 return "<Addr in unknown AF>";
70 * Convience wrapper that returns a human-readable string for the
71 * address in a prefix.
73 static const char *prefix_addr_to_a(struct prefix
*prefix
)
76 return "<No address>";
78 return addr_to_a(prefix
->family
, &prefix
->u
.prefix
);
84 * The size of an address in a given address family.
86 static size_t af_addr_size(u_char af
)
105 * Holds information about a single nexthop for netlink. These info
106 * structures are transient and may contain pointers into rib
107 * data structures for convenience.
109 typedef struct netlink_nh_info_t_
{
111 union g_addr
*gateway
;
114 * Information from the struct nexthop from which this nh was
115 * derived. For debug purposes only.
118 enum nexthop_types_t type
;
122 * netlink_route_info_t
124 * A structure for holding information for a netlink route message.
126 typedef struct netlink_route_info_t_
{
132 struct prefix
*prefix
;
134 unsigned int num_nhs
;
139 netlink_nh_info_t nhs
[MULTIPATH_NUM
];
140 union g_addr
*pref_src
;
141 } netlink_route_info_t
;
144 * netlink_route_info_add_nh
146 * Add information about the given nexthop to the given route info
149 * Returns TRUE if a nexthop was added, FALSE otherwise.
151 static int netlink_route_info_add_nh(netlink_route_info_t
*ri
,
152 struct nexthop
*nexthop
)
154 netlink_nh_info_t nhi
;
157 memset(&nhi
, 0, sizeof(nhi
));
160 if (ri
->num_nhs
>= (int)ZEBRA_NUM_OF(ri
->nhs
))
163 nhi
.recursive
= nexthop
->rparent
? 1 : 0;
164 nhi
.type
= nexthop
->type
;
165 nhi
.if_index
= nexthop
->ifindex
;
167 if (nexthop
->type
== NEXTHOP_TYPE_IPV4
168 || nexthop
->type
== NEXTHOP_TYPE_IPV4_IFINDEX
) {
169 nhi
.gateway
= &nexthop
->gate
;
170 if (nexthop
->src
.ipv4
.s_addr
)
174 if (nexthop
->type
== NEXTHOP_TYPE_IPV6
175 || nexthop
->type
== NEXTHOP_TYPE_IPV6_IFINDEX
) {
176 nhi
.gateway
= &nexthop
->gate
;
179 if (nexthop
->type
== NEXTHOP_TYPE_IFINDEX
) {
180 if (nexthop
->src
.ipv4
.s_addr
)
184 if (!nhi
.gateway
&& nhi
.if_index
== 0)
188 * We have a valid nhi. Copy the structure over to the route_info.
190 ri
->nhs
[ri
->num_nhs
] = nhi
;
193 if (src
&& !ri
->pref_src
)
200 * netlink_proto_from_route_type
202 static u_char
netlink_proto_from_route_type(int type
)
205 case ZEBRA_ROUTE_KERNEL
:
206 case ZEBRA_ROUTE_CONNECT
:
207 return RTPROT_KERNEL
;
215 * netlink_route_info_fill
217 * Fill out the route information object from the given route.
219 * Returns TRUE on success and FALSE on failure.
221 static int netlink_route_info_fill(netlink_route_info_t
*ri
, int cmd
,
222 rib_dest_t
*dest
, struct route_entry
*re
)
224 struct nexthop
*nexthop
;
226 memset(ri
, 0, sizeof(*ri
));
228 ri
->prefix
= rib_dest_prefix(dest
);
229 ri
->af
= rib_dest_af(dest
);
231 ri
->nlmsg_type
= cmd
;
232 ri
->rtm_table
= zvrf_id(rib_dest_vrf(dest
));
233 ri
->rtm_protocol
= RTPROT_UNSPEC
;
236 * An RTM_DELROUTE need not be accompanied by any nexthops,
237 * particularly in our communication with the FPM.
239 if (cmd
== RTM_DELROUTE
&& !re
)
243 zfpm_debug("%s: Expected non-NULL re pointer",
244 __PRETTY_FUNCTION__
);
248 ri
->rtm_protocol
= netlink_proto_from_route_type(re
->type
);
249 ri
->rtm_type
= RTN_UNICAST
;
250 ri
->metric
= &re
->metric
;
252 for (ALL_NEXTHOPS(re
->ng
, nexthop
)) {
253 if (ri
->num_nhs
>= multipath_num
)
256 if (CHECK_FLAG(nexthop
->flags
, NEXTHOP_FLAG_RECURSIVE
))
259 if (nexthop
->type
== NEXTHOP_TYPE_BLACKHOLE
) {
260 switch (nexthop
->bh_type
) {
261 case BLACKHOLE_ADMINPROHIB
:
262 ri
->rtm_type
= RTN_PROHIBIT
;
264 case BLACKHOLE_REJECT
:
265 ri
->rtm_type
= RTN_UNREACHABLE
;
269 ri
->rtm_type
= RTN_BLACKHOLE
;
275 if ((cmd
== RTM_NEWROUTE
276 && CHECK_FLAG(nexthop
->flags
, NEXTHOP_FLAG_ACTIVE
))
277 || (cmd
== RTM_DELROUTE
278 && CHECK_FLAG(nexthop
->flags
, NEXTHOP_FLAG_FIB
))) {
279 netlink_route_info_add_nh(ri
, nexthop
);
283 /* If there is no useful nexthop then return. */
284 if (ri
->num_nhs
== 0) {
285 zfpm_debug("netlink_encode_route(): No useful nexthop.");
293 * netlink_route_info_encode
295 * Returns the number of bytes written to the buffer. 0 or a negative
296 * value indicates an error.
298 static int netlink_route_info_encode(netlink_route_info_t
*ri
, char *in_buf
,
302 unsigned int nexthop_num
= 0;
304 netlink_nh_info_t
*nhi
;
312 req
= (void *)in_buf
;
314 buf_offset
= ((char *)req
->buf
) - ((char *)req
);
316 if (in_buf_len
< buf_offset
) {
321 memset(req
, 0, buf_offset
);
323 bytelen
= af_addr_size(ri
->af
);
325 req
->n
.nlmsg_len
= NLMSG_LENGTH(sizeof(struct rtmsg
));
326 req
->n
.nlmsg_flags
= NLM_F_CREATE
| NLM_F_REQUEST
;
327 req
->n
.nlmsg_type
= ri
->nlmsg_type
;
328 req
->r
.rtm_family
= ri
->af
;
329 req
->r
.rtm_table
= ri
->rtm_table
;
330 req
->r
.rtm_dst_len
= ri
->prefix
->prefixlen
;
331 req
->r
.rtm_protocol
= ri
->rtm_protocol
;
332 req
->r
.rtm_scope
= RT_SCOPE_UNIVERSE
;
334 addattr_l(&req
->n
, in_buf_len
, RTA_DST
, &ri
->prefix
->u
.prefix
, bytelen
);
336 req
->r
.rtm_type
= ri
->rtm_type
;
340 addattr32(&req
->n
, in_buf_len
, RTA_PRIORITY
, *ri
->metric
);
342 if (ri
->num_nhs
== 0)
345 if (ri
->num_nhs
== 1) {
349 addattr_l(&req
->n
, in_buf_len
, RTA_GATEWAY
,
350 nhi
->gateway
, bytelen
);
354 addattr32(&req
->n
, in_buf_len
, RTA_OIF
, nhi
->if_index
);
363 char buf
[NL_PKT_BUF_SIZE
];
364 struct rtattr
*rta
= (void *)buf
;
365 struct rtnexthop
*rtnh
;
367 rta
->rta_type
= RTA_MULTIPATH
;
368 rta
->rta_len
= RTA_LENGTH(0);
369 rtnh
= RTA_DATA(rta
);
371 for (nexthop_num
= 0; nexthop_num
< ri
->num_nhs
; nexthop_num
++) {
372 nhi
= &ri
->nhs
[nexthop_num
];
374 rtnh
->rtnh_len
= sizeof(*rtnh
);
375 rtnh
->rtnh_flags
= 0;
377 rtnh
->rtnh_ifindex
= 0;
378 rta
->rta_len
+= rtnh
->rtnh_len
;
381 rta_addattr_l(rta
, sizeof(buf
), RTA_GATEWAY
,
382 nhi
->gateway
, bytelen
);
383 rtnh
->rtnh_len
+= sizeof(struct rtattr
) + bytelen
;
387 rtnh
->rtnh_ifindex
= nhi
->if_index
;
390 rtnh
= RTNH_NEXT(rtnh
);
393 assert(rta
->rta_len
> RTA_LENGTH(0));
394 addattr_l(&req
->n
, in_buf_len
, RTA_MULTIPATH
, RTA_DATA(rta
),
400 addattr_l(&req
->n
, in_buf_len
, RTA_PREFSRC
, &ri
->pref_src
,
404 assert(req
->n
.nlmsg_len
< in_buf_len
);
405 return req
->n
.nlmsg_len
;
409 * zfpm_log_route_info
411 * Helper function to log the information in a route_info structure.
413 static void zfpm_log_route_info(netlink_route_info_t
*ri
, const char *label
)
415 netlink_nh_info_t
*nhi
;
418 zfpm_debug("%s : %s %s/%d, Proto: %s, Metric: %u", label
,
419 nl_msg_type_to_str(ri
->nlmsg_type
),
420 prefix_addr_to_a(ri
->prefix
), ri
->prefix
->prefixlen
,
421 nl_rtproto_to_str(ri
->rtm_protocol
),
422 ri
->metric
? *ri
->metric
: 0);
424 for (i
= 0; i
< ri
->num_nhs
; i
++) {
426 zfpm_debug(" Intf: %u, Gateway: %s, Recursive: %s, Type: %s",
427 nhi
->if_index
, addr_to_a(ri
->af
, nhi
->gateway
),
428 nhi
->recursive
? "yes" : "no",
429 nexthop_type_to_str(nhi
->type
));
434 * zfpm_netlink_encode_route
436 * Create a netlink message corresponding to the given route in the
437 * given buffer space.
439 * Returns the number of bytes written to the buffer. 0 or a negative
440 * value indicates an error.
442 int zfpm_netlink_encode_route(int cmd
, rib_dest_t
*dest
, struct route_entry
*re
,
443 char *in_buf
, size_t in_buf_len
)
445 netlink_route_info_t ri_space
, *ri
;
449 if (!netlink_route_info_fill(ri
, cmd
, dest
, re
))
452 zfpm_log_route_info(ri
, __FUNCTION__
);
454 return netlink_route_info_encode(ri
, in_buf
, in_buf_len
);
457 #endif /* HAVE_NETLINK */