2 * Copyright (c) 2009 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.
19 #include <netinet/in.h>
24 dpid_from_string(const char *s, uint64_t *dpidp)
26 *dpidp = (strlen(s) == 16 && strspn(s, "0123456789abcdefABCDEF") == 16
27 ? strtoll(s, NULL, 16)
33 eth_addr_from_string(const char *s, uint8_t ea[ETH_ADDR_LEN])
35 if (sscanf(s, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(ea))
36 == ETH_ADDR_SCAN_COUNT) {
39 memset(ea, 0, ETH_ADDR_LEN);
44 /* Fills 'b' with an 802.2 SNAP packet with Ethernet source address 'eth_src',
45 * the Nicira OUI as SNAP organization and 'snap_type' as SNAP type. The text
46 * string in 'tag' is enclosed as the packet payload.
48 * This function is used by Open vSwitch to compose packets in cases where
49 * context is important but content doesn't (or shouldn't) matter. For this
50 * purpose, 'snap_type' should be a random number and 'tag' should be an
51 * English phrase that explains the purpose of the packet. (The English phrase
52 * gives hapless admins running Wireshark the opportunity to figure out what's
55 compose_benign_packet(struct ofpbuf *b, const char *tag, uint16_t snap_type,
56 const uint8_t eth_src[ETH_ADDR_LEN])
58 struct eth_header *eth;
59 struct llc_snap_header *llc_snap;
61 /* Compose basic packet structure. (We need the payload size to stick into
62 * the 802.2 header.) */
64 eth = ofpbuf_put_zeros(b, ETH_HEADER_LEN);
65 llc_snap = ofpbuf_put_zeros(b, LLC_SNAP_HEADER_LEN);
66 ofpbuf_put(b, tag, strlen(tag) + 1); /* Includes null byte. */
67 ofpbuf_put(b, eth_src, ETH_ADDR_LEN);
69 /* Compose 802.2 header. */
70 memcpy(eth->eth_dst, eth_addr_broadcast, ETH_ADDR_LEN);
71 memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN);
72 eth->eth_type = htons(b->size - ETH_HEADER_LEN);
74 /* Compose LLC, SNAP headers. */
75 llc_snap->llc.llc_dsap = LLC_DSAP_SNAP;
76 llc_snap->llc.llc_ssap = LLC_SSAP_SNAP;
77 llc_snap->llc.llc_cntl = LLC_CNTL_SNAP;
78 memcpy(llc_snap->snap.snap_org, "\x00\x23\x20", 3);
79 llc_snap->snap.snap_type = htons(snap_type);