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7c40bf39 | 1 | /* BGP FlowSpec for packet handling |
2 | * Portions: | |
3 | * Copyright (C) 2017 ChinaTelecom SDN Group | |
4 | * Copyright (C) 2018 6WIND | |
5 | * | |
6 | * FRRouting is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2, or (at your option) any | |
9 | * later version. | |
10 | * | |
11 | * FRRouting is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License along | |
17 | * with this program; see the file COPYING; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | */ | |
20 | ||
21 | #include "math.h" | |
22 | ||
23 | #include <zebra.h> | |
24 | #include "prefix.h" | |
25 | ||
26 | #include "bgpd/bgpd.h" | |
27 | #include "bgpd/bgp_route.h" | |
28 | #include "bgpd/bgp_flowspec.h" | |
fc836540 | 29 | #include "bgpd/bgp_flowspec_util.h" |
7c40bf39 | 30 | #include "bgpd/bgp_flowspec_private.h" |
268e1b9b PG |
31 | #include "bgpd/bgp_ecommunity.h" |
32 | #include "bgpd/bgp_debug.h" | |
7c40bf39 | 33 | |
fc836540 PG |
34 | static int bgp_fs_nlri_validate(uint8_t *nlri_content, uint32_t len) |
35 | { | |
36 | uint32_t offset = 0; | |
37 | int type; | |
38 | int ret = 0, error = 0; | |
39 | ||
40 | while (offset < len-1) { | |
41 | type = nlri_content[offset]; | |
42 | offset++; | |
43 | switch (type) { | |
44 | case FLOWSPEC_DEST_PREFIX: | |
45 | case FLOWSPEC_SRC_PREFIX: | |
46 | ret = bgp_flowspec_ip_address( | |
47 | BGP_FLOWSPEC_VALIDATE_ONLY, | |
48 | nlri_content + offset, | |
49 | len - offset, NULL, &error); | |
50 | break; | |
51 | case FLOWSPEC_IP_PROTOCOL: | |
52 | case FLOWSPEC_PORT: | |
53 | case FLOWSPEC_DEST_PORT: | |
54 | case FLOWSPEC_SRC_PORT: | |
55 | case FLOWSPEC_ICMP_TYPE: | |
56 | case FLOWSPEC_ICMP_CODE: | |
57 | ret = bgp_flowspec_op_decode(BGP_FLOWSPEC_VALIDATE_ONLY, | |
58 | nlri_content + offset, | |
59 | len - offset, NULL, &error); | |
60 | break; | |
61 | case FLOWSPEC_TCP_FLAGS: | |
62 | ret = bgp_flowspec_tcpflags_decode( | |
63 | BGP_FLOWSPEC_VALIDATE_ONLY, | |
64 | nlri_content + offset, | |
65 | len - offset, NULL, &error); | |
66 | break; | |
67 | case FLOWSPEC_PKT_LEN: | |
68 | case FLOWSPEC_DSCP: | |
69 | ret = bgp_flowspec_op_decode( | |
70 | BGP_FLOWSPEC_VALIDATE_ONLY, | |
71 | nlri_content + offset, | |
72 | len - offset, NULL, &error); | |
73 | break; | |
74 | case FLOWSPEC_FRAGMENT: | |
75 | ret = bgp_flowspec_fragment_type_decode( | |
76 | BGP_FLOWSPEC_VALIDATE_ONLY, | |
77 | nlri_content + offset, | |
78 | len - offset, NULL, &error); | |
79 | break; | |
80 | default: | |
81 | error = -1; | |
82 | break; | |
83 | } | |
84 | offset += ret; | |
85 | if (error < 0) | |
86 | break; | |
87 | } | |
88 | return error; | |
89 | } | |
90 | ||
7c40bf39 | 91 | int bgp_nlri_parse_flowspec(struct peer *peer, struct attr *attr, |
92 | struct bgp_nlri *packet, int withdraw) | |
93 | { | |
94 | uint8_t *pnt; | |
95 | uint8_t *lim; | |
96 | afi_t afi; | |
fc836540 | 97 | safi_t safi; |
7c40bf39 | 98 | int psize = 0; |
99 | uint8_t rlen; | |
100 | struct prefix p; | |
fc836540 PG |
101 | int ret; |
102 | void *temp; | |
7c40bf39 | 103 | |
104 | /* Start processing the NLRI - there may be multiple in the MP_REACH */ | |
105 | pnt = packet->nlri; | |
106 | lim = pnt + packet->length; | |
107 | afi = packet->afi; | |
fc836540 | 108 | safi = packet->safi; |
7c40bf39 | 109 | |
110 | if (afi == AFI_IP6) { | |
111 | zlog_err("BGP flowspec IPv6 not supported"); | |
112 | return -1; | |
113 | } | |
114 | ||
115 | if (packet->length >= FLOWSPEC_NLRI_SIZELIMIT) { | |
116 | zlog_err("BGP flowspec nlri length maximum reached (%u)", | |
117 | packet->length); | |
118 | return -1; | |
119 | } | |
120 | ||
121 | for (; pnt < lim; pnt += psize) { | |
122 | /* Clear prefix structure. */ | |
123 | memset(&p, 0, sizeof(struct prefix)); | |
124 | ||
125 | /* All FlowSpec NLRI begin with length. */ | |
126 | if (pnt + 1 > lim) | |
127 | return -1; | |
128 | ||
129 | psize = rlen = *pnt++; | |
130 | ||
131 | /* When packet overflow occur return immediately. */ | |
132 | if (pnt + psize > lim) { | |
133 | zlog_err("Flowspec NLRI length inconsistent ( size %u seen)", | |
134 | psize); | |
135 | return -1; | |
136 | } | |
fc836540 PG |
137 | if (bgp_fs_nlri_validate(pnt, psize) < 0) { |
138 | zlog_err("Bad flowspec format or NLRI options not supported"); | |
139 | return -1; | |
140 | } | |
141 | p.family = AF_FLOWSPEC; | |
142 | p.prefixlen = 0; | |
143 | /* Flowspec encoding is in bytes */ | |
144 | p.u.prefix_flowspec.prefixlen = psize; | |
145 | temp = XCALLOC(MTYPE_TMP, psize); | |
146 | memcpy(temp, pnt, psize); | |
147 | p.u.prefix_flowspec.ptr = (uintptr_t) temp; | |
268e1b9b PG |
148 | |
149 | if (BGP_DEBUG(flowspec, FLOWSPEC)) { | |
150 | char return_string[BGP_FLOWSPEC_NLRI_STRING_MAX]; | |
151 | char local_string[BGP_FLOWSPEC_NLRI_STRING_MAX]; | |
152 | char ec_string[BGP_FLOWSPEC_NLRI_STRING_MAX]; | |
153 | char *s = NULL; | |
154 | ||
155 | bgp_fs_nlri_get_string((unsigned char *) | |
156 | p.u.prefix_flowspec.ptr, | |
157 | p.u.prefix_flowspec.prefixlen, | |
158 | return_string, | |
d33fc23b | 159 | NLRI_STRING_FORMAT_MIN, NULL); |
268e1b9b PG |
160 | snprintf(ec_string, BGP_FLOWSPEC_NLRI_STRING_MAX, |
161 | "EC{none}"); | |
162 | if (attr && attr->ecommunity) { | |
163 | s = ecommunity_ecom2str(attr->ecommunity, | |
164 | ECOMMUNITY_FORMAT_ROUTE_MAP, 0); | |
165 | snprintf(ec_string, | |
166 | BGP_FLOWSPEC_NLRI_STRING_MAX, | |
167 | "EC{%s}", | |
168 | s == NULL ? "none" : s); | |
c7ee6c35 DS |
169 | |
170 | if (s) | |
171 | ecommunity_strfree(&s); | |
268e1b9b PG |
172 | } |
173 | snprintf(local_string, BGP_FLOWSPEC_NLRI_STRING_MAX, | |
174 | "FS Rx %s %s %s %s", withdraw ? | |
175 | "Withdraw":"Update", | |
176 | afi2str(afi), return_string, | |
177 | attr != NULL ? ec_string : ""); | |
178 | zlog_info("%s", local_string); | |
179 | } | |
fc836540 PG |
180 | /* Process the route. */ |
181 | if (!withdraw) | |
182 | ret = bgp_update(peer, &p, 0, attr, | |
183 | afi, safi, | |
184 | ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL, | |
185 | NULL, NULL, 0, 0, NULL); | |
186 | else | |
187 | ret = bgp_withdraw(peer, &p, 0, attr, | |
188 | afi, safi, | |
189 | ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL, | |
190 | NULL, NULL, 0, NULL); | |
191 | if (ret) { | |
192 | zlog_err("Flowspec NLRI failed to be %s.", | |
193 | attr ? "added" : "withdrawn"); | |
194 | return -1; | |
195 | } | |
7c40bf39 | 196 | } |
197 | return 0; | |
198 | } |