2 * Copyright (c) 2009, 2010, 2011 Nicira Networks.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 #include <arpa/inet.h>
21 #include <netinet/in.h>
23 #include "byte-order.h"
24 #include "dynamic-string.h"
27 const struct in6_addr in6addr_exact = IN6ADDR_EXACT_INIT;
29 /* Parses 's' as a 16-digit hexadecimal number representing a datapath ID. On
30 * success stores the dpid into '*dpidp' and returns true, on failure stores 0
31 * into '*dpidp' and returns false.
33 * Rejects an all-zeros dpid as invalid. */
35 dpid_from_string(const char *s, uint64_t *dpidp)
37 *dpidp = (strlen(s) == 16 && strspn(s, "0123456789abcdefABCDEF") == 16
38 ? strtoull(s, NULL, 16)
44 eth_addr_from_string(const char *s, uint8_t ea[ETH_ADDR_LEN])
46 if (sscanf(s, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(ea))
47 == ETH_ADDR_SCAN_COUNT) {
50 memset(ea, 0, ETH_ADDR_LEN);
55 /* Fills 'b' with an 802.2 SNAP packet with Ethernet source address 'eth_src',
56 * the Nicira OUI as SNAP organization and 'snap_type' as SNAP type. The text
57 * string in 'tag' is enclosed as the packet payload.
59 * This function is used by Open vSwitch to compose packets in cases where
60 * context is important but content doesn't (or shouldn't) matter. For this
61 * purpose, 'snap_type' should be a random number and 'tag' should be an
62 * English phrase that explains the purpose of the packet. (The English phrase
63 * gives hapless admins running Wireshark the opportunity to figure out what's
66 compose_benign_packet(struct ofpbuf *b, const char *tag, uint16_t snap_type,
67 const uint8_t eth_src[ETH_ADDR_LEN])
69 size_t tag_size = strlen(tag) + 1;
72 payload = snap_compose(b, eth_addr_broadcast, eth_src, 0x002320, snap_type,
73 tag_size + ETH_ADDR_LEN);
74 memcpy(payload, tag, tag_size);
75 memcpy(payload + tag_size, eth_src, ETH_ADDR_LEN);
78 /* Stores the string representation of the IPv6 address 'addr' into the
79 * character array 'addr_str', which must be at least INET6_ADDRSTRLEN
82 format_ipv6_addr(char *addr_str, const struct in6_addr *addr)
84 inet_ntop(AF_INET6, addr, addr_str, INET6_ADDRSTRLEN);
88 print_ipv6_addr(struct ds *string, const struct in6_addr *addr)
90 char addr_str[INET6_ADDRSTRLEN];
92 format_ipv6_addr(addr_str, addr);
93 ds_put_format(string, "%s", addr_str);
96 struct in6_addr ipv6_addr_bitand(const struct in6_addr *a,
97 const struct in6_addr *b)
103 for (i=0; i<4; i++) {
104 dst.s6_addr32[i] = a->s6_addr32[i] & b->s6_addr32[i];
107 for (i=0; i<16; i++) {
108 dst.s6_addr[i] = a->s6_addr[i] & b->s6_addr[i];
115 /* Returns an in6_addr consisting of 'mask' high-order 1-bits and 128-N
116 * low-order 0-bits. */
118 ipv6_create_mask(int mask)
120 struct in6_addr netmask;
121 uint8_t *netmaskp = &netmask.s6_addr[0];
123 memset(&netmask, 0, sizeof netmask);
131 *netmaskp = 0xff << (8 - mask);
137 /* Given the IPv6 netmask 'netmask', returns the number of bits of the
138 * IPv6 address that it wildcards. 'netmask' must be a CIDR netmask (see
139 * ipv6_is_cidr()). */
141 ipv6_count_cidr_bits(const struct in6_addr *netmask)
145 const uint8_t *netmaskp = &netmask->s6_addr[0];
147 assert(ipv6_is_cidr(netmask));
149 for (i=0; i<16; i++) {
150 if (netmaskp[i] == 0xff) {
155 for(nm = netmaskp[i]; nm; nm <<= 1) {
167 /* Returns true if 'netmask' is a CIDR netmask, that is, if it consists of N
168 * high-order 1-bits and 128-N low-order 0-bits. */
170 ipv6_is_cidr(const struct in6_addr *netmask)
172 const uint8_t *netmaskp = &netmask->s6_addr[0];
175 for (i=0; i<16; i++) {
176 if (netmaskp[i] != 0xff) {
177 uint8_t x = ~netmaskp[i];
192 /* Populates 'b' with an Ethernet II packet headed with the given 'eth_dst',
193 * 'eth_src' and 'eth_type' parameters. A payload of 'size' bytes is allocated
194 * in 'b' and returned. This payload may be populated with appropriate
195 * information by the caller. */
197 eth_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN],
198 const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
202 struct eth_header *eth;
206 ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + size);
207 eth = ofpbuf_put_uninit(b, ETH_HEADER_LEN);
208 data = ofpbuf_put_uninit(b, size);
210 memcpy(eth->eth_dst, eth_dst, ETH_ADDR_LEN);
211 memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN);
212 eth->eth_type = htons(eth_type);
217 /* Populates 'b' with an Ethernet LLC+SNAP packet headed with the given
218 * 'eth_dst', 'eth_src', 'snap_org', and 'snap_type'. A payload of 'size'
219 * bytes is allocated in 'b' and returned. This payload may be populated with
220 * appropriate information by the caller. */
222 snap_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN],
223 const uint8_t eth_src[ETH_ADDR_LEN],
224 unsigned int oui, uint16_t snap_type, size_t size)
226 struct eth_header *eth;
227 struct llc_snap_header *llc_snap;
230 /* Compose basic packet structure. (We need the payload size to stick into
231 * the 802.2 header.) */
233 ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + LLC_SNAP_HEADER_LEN + size);
234 eth = ofpbuf_put_zeros(b, ETH_HEADER_LEN);
235 llc_snap = ofpbuf_put_zeros(b, LLC_SNAP_HEADER_LEN);
236 payload = ofpbuf_put_uninit(b, size);
238 /* Compose 802.2 header. */
239 memcpy(eth->eth_dst, eth_dst, ETH_ADDR_LEN);
240 memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN);
241 eth->eth_type = htons(b->size - ETH_HEADER_LEN);
243 /* Compose LLC, SNAP headers. */
244 llc_snap->llc.llc_dsap = LLC_DSAP_SNAP;
245 llc_snap->llc.llc_ssap = LLC_SSAP_SNAP;
246 llc_snap->llc.llc_cntl = LLC_CNTL_SNAP;
247 llc_snap->snap.snap_org[0] = oui >> 16;
248 llc_snap->snap.snap_org[1] = oui >> 8;
249 llc_snap->snap.snap_org[2] = oui;
250 llc_snap->snap.snap_type = htons(snap_type);
255 /* Populates 'pdu' with a LACP PDU comprised of 'actor' and 'partner'. */
257 compose_lacp_pdu(const struct lacp_info *actor,
258 const struct lacp_info *partner, struct lacp_pdu *pdu)
260 memset(pdu, 0, sizeof *pdu);
269 pdu->partner_type = 2;
270 pdu->partner_len = 20;
271 pdu->partner = *partner;
273 pdu->collector_type = 3;
274 pdu->collector_len = 16;
275 pdu->collector_delay = htons(0);
278 /* Parses 'b' which represents a packet containing a LACP PDU. This function
279 * returns NULL if 'b' is malformed, or does not represent a LACP PDU format
280 * supported by OVS. Otherwise, it returns a pointer to the lacp_pdu contained
282 const struct lacp_pdu *
283 parse_lacp_packet(const struct ofpbuf *b)
285 const struct lacp_pdu *pdu;
287 pdu = ofpbuf_at(b, (uint8_t *)b->l3 - (uint8_t *)b->data, LACP_PDU_LEN);
289 if (pdu && pdu->subtype == 1
290 && pdu->actor_type == 1 && pdu->actor_len == 20
291 && pdu->partner_type == 2 && pdu->partner_len == 20) {