Annotation of embedaddon/quagga/pimd/pim_rpf.c, revision 1.1.1.1
1.1 misho 1: /*
2: PIM for Quagga
3: Copyright (C) 2008 Everton da Silva Marques
4:
5: This program is free software; you can redistribute it and/or modify
6: it under the terms of the GNU General Public License as published by
7: the Free Software Foundation; either version 2 of the License, or
8: (at your option) any later version.
9:
10: This program is distributed in the hope that it will be useful, but
11: WITHOUT ANY WARRANTY; without even the implied warranty of
12: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13: General Public License for more details.
14:
15: You should have received a copy of the GNU General Public License
16: along with this program; see the file COPYING; if not, write to the
17: Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
18: MA 02110-1301 USA
19:
20: $QuaggaId: $Format:%an, %ai, %h$ $
21: */
22:
23: #include <zebra.h>
24:
25: #include "log.h"
26: #include "prefix.h"
27: #include "memory.h"
28:
29: #include "pimd.h"
30: #include "pim_rpf.h"
31: #include "pim_pim.h"
32: #include "pim_str.h"
33: #include "pim_iface.h"
34: #include "pim_zlookup.h"
35: #include "pim_ifchannel.h"
36:
37: static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
38:
39: int pim_nexthop_lookup(struct pim_nexthop *nexthop,
40: struct in_addr addr)
41: {
42: struct pim_zlookup_nexthop nexthop_tab[PIM_NEXTHOP_IFINDEX_TAB_SIZE];
43: int num_ifindex;
44: struct interface *ifp;
45: int first_ifindex;
46:
47: num_ifindex = zclient_lookup_nexthop(qpim_zclient_lookup, nexthop_tab,
48: PIM_NEXTHOP_IFINDEX_TAB_SIZE,
49: addr, PIM_NEXTHOP_LOOKUP_MAX);
50: if (num_ifindex < 1) {
51: char addr_str[100];
52: pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
53: zlog_warn("%s %s: could not find nexthop ifindex for address %s",
54: __FILE__, __PRETTY_FUNCTION__,
55: addr_str);
56: return -1;
57: }
58:
59: first_ifindex = nexthop_tab[0].ifindex;
60:
61: if (num_ifindex > 1) {
62: char addr_str[100];
63: pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
64: zlog_info("%s %s: FIXME ignoring multiple nexthop ifindex'es num_ifindex=%d for address %s (using only ifindex=%d)",
65: __FILE__, __PRETTY_FUNCTION__,
66: num_ifindex, addr_str, first_ifindex);
67: /* debug warning only, do not return */
68: }
69:
70: ifp = if_lookup_by_index(first_ifindex);
71: if (!ifp) {
72: char addr_str[100];
73: pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
74: zlog_warn("%s %s: could not find interface for ifindex %d (address %s)",
75: __FILE__, __PRETTY_FUNCTION__,
76: first_ifindex, addr_str);
77: return -2;
78: }
79:
80: if (!ifp->info) {
81: char addr_str[100];
82: pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
83: zlog_warn("%s: multicast not enabled on input interface %s (ifindex=%d, RPF for source %s)",
84: __PRETTY_FUNCTION__,
85: ifp->name, first_ifindex, addr_str);
86: /* debug warning only, do not return */
87: }
88:
89: if (PIM_DEBUG_PIM_TRACE) {
90: char nexthop_str[100];
91: char addr_str[100];
92: pim_inet4_dump("<nexthop?>", nexthop_tab[0].nexthop_addr, nexthop_str, sizeof(nexthop_str));
93: pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
94: zlog_debug("%s %s: found nexthop %s for address %s: interface %s ifindex=%d metric=%d pref=%d",
95: __FILE__, __PRETTY_FUNCTION__,
96: nexthop_str, addr_str,
97: ifp->name, first_ifindex,
98: nexthop_tab[0].route_metric,
99: nexthop_tab[0].protocol_distance);
100: }
101:
102: /* update nextop data */
103: nexthop->interface = ifp;
104: nexthop->mrib_nexthop_addr = nexthop_tab[0].nexthop_addr;
105: nexthop->mrib_metric_preference = nexthop_tab[0].protocol_distance;
106: nexthop->mrib_route_metric = nexthop_tab[0].route_metric;
107:
108: return 0;
109: }
110:
111: static int nexthop_mismatch(const struct pim_nexthop *nh1,
112: const struct pim_nexthop *nh2)
113: {
114: return (nh1->interface != nh2->interface)
115: ||
116: (nh1->mrib_nexthop_addr.s_addr != nh2->mrib_nexthop_addr.s_addr)
117: ||
118: (nh1->mrib_metric_preference != nh2->mrib_metric_preference)
119: ||
120: (nh1->mrib_route_metric != nh2->mrib_route_metric);
121: }
122:
123: enum pim_rpf_result pim_rpf_update(struct pim_upstream *up,
124: struct in_addr *old_rpf_addr)
125: {
126: struct in_addr save_rpf_addr;
127: struct pim_nexthop save_nexthop;
128: struct pim_rpf *rpf = &up->rpf;
129:
130: save_nexthop = rpf->source_nexthop; /* detect change in pim_nexthop */
131: save_rpf_addr = rpf->rpf_addr; /* detect change in RPF'(S,G) */
132:
133: if (pim_nexthop_lookup(&rpf->source_nexthop,
134: up->source_addr)) {
135: return PIM_RPF_FAILURE;
136: }
137:
138: rpf->rpf_addr = pim_rpf_find_rpf_addr(up);
139: if (PIM_INADDR_IS_ANY(rpf->rpf_addr) && PIM_DEBUG_PIM_EVENTS) {
140: /* RPF'(S,G) not found */
141: char src_str[100];
142: char grp_str[100];
143: pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
144: pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
145: zlog_debug("%s %s: RPF'(%s,%s) not found: won't send join upstream",
146: __FILE__, __PRETTY_FUNCTION__,
147: src_str, grp_str);
148: /* warning only */
149: }
150:
151: /* detect change in pim_nexthop */
152: if (nexthop_mismatch(&rpf->source_nexthop, &save_nexthop)) {
153:
154: if (PIM_DEBUG_PIM_EVENTS) {
155: char src_str[100];
156: char grp_str[100];
157: char nhaddr_str[100];
158: pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
159: pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
160: pim_inet4_dump("<addr?>", rpf->source_nexthop.mrib_nexthop_addr, nhaddr_str, sizeof(nhaddr_str));
161: zlog_debug("%s %s: (S,G)=(%s,%s) source nexthop now is: interface=%s address=%s pref=%d metric=%d",
162: __FILE__, __PRETTY_FUNCTION__,
163: src_str, grp_str,
164: rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
165: nhaddr_str,
166: rpf->source_nexthop.mrib_metric_preference,
167: rpf->source_nexthop.mrib_route_metric);
168: /* warning only */
169: }
170:
171: pim_upstream_update_join_desired(up);
172: pim_upstream_update_could_assert(up);
173: pim_upstream_update_my_assert_metric(up);
174: }
175:
176: /* detect change in RPF_interface(S) */
177: if (save_nexthop.interface != rpf->source_nexthop.interface) {
178:
179: if (PIM_DEBUG_PIM_EVENTS) {
180: char src_str[100];
181: char grp_str[100];
182: pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
183: pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
184: zlog_debug("%s %s: (S,G)=(%s,%s) RPF_interface(S) changed from %s to %s",
185: __FILE__, __PRETTY_FUNCTION__,
186: src_str, grp_str,
187: save_nexthop.interface ? save_nexthop.interface->name : "<oldif?>",
188: rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
189: /* warning only */
190: }
191:
192: pim_upstream_rpf_interface_changed(up, save_nexthop.interface);
193: }
194:
195: /* detect change in RPF'(S,G) */
196: if (save_rpf_addr.s_addr != rpf->rpf_addr.s_addr) {
197:
198: /* return old rpf to caller ? */
199: if (old_rpf_addr)
200: *old_rpf_addr = save_rpf_addr;
201:
202: return PIM_RPF_CHANGED;
203: }
204:
205: return PIM_RPF_OK;
206: }
207:
208: /*
209: RFC 4601: 4.1.6. State Summarization Macros
210:
211: neighbor RPF'(S,G) {
212: if ( I_Am_Assert_Loser(S, G, RPF_interface(S) )) {
213: return AssertWinner(S, G, RPF_interface(S) )
214: } else {
215: return NBR( RPF_interface(S), MRIB.next_hop( S ) )
216: }
217: }
218:
219: RPF'(*,G) and RPF'(S,G) indicate the neighbor from which data
220: packets should be coming and to which joins should be sent on the RP
221: tree and SPT, respectively.
222: */
223: static struct in_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
224: {
225: struct pim_ifchannel *rpf_ch;
226: struct pim_neighbor *neigh;
227: struct in_addr rpf_addr;
228:
229: if (!up->rpf.source_nexthop.interface) {
230: char src_str[100];
231: char grp_str[100];
232: pim_inet4_dump("<src?>", up->source_addr, src_str, sizeof(src_str));
233: pim_inet4_dump("<grp?>", up->group_addr, grp_str, sizeof(grp_str));
234: zlog_warn("%s: missing RPF interface for upstream (S,G)=(%s,%s)",
235: __PRETTY_FUNCTION__,
236: src_str, grp_str);
237:
238: rpf_addr.s_addr = PIM_NET_INADDR_ANY;
239: return rpf_addr;
240: }
241:
242: rpf_ch = pim_ifchannel_find(up->rpf.source_nexthop.interface,
243: up->source_addr, up->group_addr);
244: if (rpf_ch) {
245: if (rpf_ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
246: return rpf_ch->ifassert_winner;
247: }
248: }
249:
250: /* return NBR( RPF_interface(S), MRIB.next_hop( S ) ) */
251:
252: neigh = pim_if_find_neighbor(up->rpf.source_nexthop.interface,
253: up->rpf.source_nexthop.mrib_nexthop_addr);
254: if (neigh)
255: rpf_addr = neigh->source_addr;
256: else
257: rpf_addr.s_addr = PIM_NET_INADDR_ANY;
258:
259: return rpf_addr;
260: }
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