1liblldp_clif(3) Linux liblldp_clif(3)
2
6 clif_vsi,clif_vsievt,clif_vsiwait - Manipulate VDP IEEE 802.1 Ratified
7 Standard Assocications
8
10 #include "include/clif.h"
11 int clif_vsi(struct clif *connp, char *ifname, unsigned int tlvid, char
13 *cmd, char *reply, size_t *reply_len);
14 int clif_vsievt(struct clif *connp, char *reply, size_t *reply_len, int
16 wait);
17 int clif_vsiwait(struct clif *connp, char *ifname, unsigned int tlvid,
19 char *cmd, char *reply, size_t *reply_len, int wait);
20
23 The Virtual station interface Discovery Protocol is a protocol to man‐
24 age the association and deassociation of virtual machine network inter‐
25 faces (VSIs) between the station and an adjacent switch. VDP is typi‐
26 cally used with the local switch in VEPA mode and the adjacent switch
27 port in reflective relay (also called haripin) mode. This allows all
28 traffic to be sent to the switch for processing. Reflective relay mode
29 is negotiated via EVB TLVs (see lldptool-evb).
30 This man pages describes the IEEE 802.1 Qbg ratified standard dated
32 from July 5th, 2012. This differs from the draft 0.2 which is imple‐
33 mented as well, see lldptool-vdp(8). For clarification in this man
34 page the version complying to the ratified standard is called VDP22 and
35 the version complying to the draft 0.2 is called VDP.
36 VSI Parameter
38 Each VDP22 TLVs contains a command mode, manager identifier, type iden‐
39 tifier, type identifier version, VSI instance identifier, migiration
40 hints and filter information. The fields are explained next:
41 Command Mode:
43 The command mode determines the type of the VSI association to
44 be established. It is an ascii string can be one of:
45 assoc: Create an VSI association.
47 preassoc:
49 Create an VSI preassociation. The association is only
50 announced to the switch.
51 preassoc-rr:
53 Create an VSI preassociation. The association is only
54 announced to the switch and the switch should reserve the
55 resources.
56 deassoc:
58 Delete an VSI association.
59 Other strings are not recognized and return an error.
60 Manager identifier:
62 The manager identifier is a string of up to 16 alphanumeric
63 characters. It can also be an UUID according to RFC 4122 with
64 optional dashes in between.
65 Type Identifier:
67 The type identifier is a number in the range of 0 to 2^24 - 1.
68 Type Identifier Version:
70 The type identifer version is a number in the range of 0 to 255.
71 VSI Instance Identifier:
73 The VSI instance identifier is an UUID according to RFC 4122
74 with optional dashes in between.
75 Migration Hints:
77 The migiration hints is a string aiding in migration of virtual
78 machines:
79 none: No hints available.
81 from: The virtual machine is migriting away.
83 to: The virtual machine is migriting to.
85 Filter Information Data:
87 The filter information data can be supplied in four different
88 formats:
89 vlan (1)
91 A vlan number only, also known as filter information for‐
92 mat 1. The vlan identifier is a number in the range of 1
93 to 2^16 - 1. The high order 4 bits are used as quality
94 of service bits. The vlan identifier can be zero, a vlan
95 identifier is then selected by the switch. Refer to IEEE
96 802.1 Qbg ratified standard for details.
97 vlan-mac (2)
99 A vlan number and MAC address delimited by a slash ('-'),
100 also known as filter information format 2. The MAC
101 address is specified in the format xx:xx:xx:xx:xx:xx.
102 The colons are mandatory. For vlan details see (1).
103 vlan-mac-group (4)
105 A vlan number, MAC address and group identifier, each
106 delimited by a slash ('-'), also known as filter informa‐
107 tion format 4. The group identifier is a 32 bit number.
108 For vlan and MAC address details see (1) and (2).
109 vlan--group (3)
111 A vlan number and group identifier, delimited by two
112 slashes ('--'), also known as filter information format
113 3. For vlan and group details see (1) and (4).
114 Several filter information fields can be supplied. The have to be sep‐
115 arated by comma (',') and must be of the same format.
116 clif_vsi
118 This function sends a VSI command to lldpad(8). Parameter connp is a
119 pointer to the connection information. This information is obtained by
120 calling clif_open and clif_attach. Parameter ifname is the interface
121 name lldpad [22m(8) uses to send the VSI data. Paramenter tlvid is the
122 number of the VSI request. Valid numbers are 1 (for Preassociation), 2
123 (for Preassociation with resource reservation) and 3 (for association),
124 4 (for Deassociation). Parameter cmd points to a character string con‐
125 taining the VSI command. The layout of the VSI command has been
126 explained above. All VSI fields are concatenated together and sepa‐
127 rated to by commas (',') to form one large string. Parameter reply is
128 a pointer to a character array to receive the reply from lldpad(8).
129 Parameter reply_len holds the maximum number of characters available in
130 the array pointed to by reply. On successful return of the call,
131 reply_len contains the number of characters stored by lldpad(8) as the
132 response of the command.
133 The functions returns zero on success and the reply and reply_len
135 parameters are set. Reply_len contains the number of bytes in the mem‐
136 ory area pointed to by reply. Reply contains the same information and
137 format as the cmd parameter with several exceptions:
138 Command Mode:
140 This field should be the same as in cmd parameter. If it
141 contains deassoc then the command failed and the field
142 ,igration hints contains an error numner.
143 Migration Hints:
145 This field contains the error number on why the command
146 was not accepted by lldpad(8). This command failed to
147 pass the lldpad(8) sanity checks. Note that the command
148 was not even sent to the switch for processing. If no
149 error occured, this field contains a dash ('-').
150 Filter Information Data:
152 If parameter cmd contained the a vlan identifier of value
153 zero or a group identifier the switch is allowed to
154 assign a different vlan identifier, which is saved and
155 returned in the reply buffer.
156 All the other fields should be returned unchanged.
157 The function returns zero when the command was accepted by lldpad(8).
159 Otherwise it returns a positive number on why the command was not
160 accepted.
161 clif_vsievt
163 After a successful return of clif_vsi, lldpad(8) has sent the command
164 to the switch and waits for a response from the switch. The switch can
165 still deny the request. Function clif_vsievt waits for parameter wait
166 seconds for a reply from lldpad(8). Parameter reply_len specifies the
167 maximum buffer size pointed to by parameter reply. If a response was
168 received in wait seconds, the function returns zero and sets reply_len
169 to the number of bytes received and reply contains the response. The
170 format is the same as in clif_vsi.
171 Since the switch can disassociate an established VSI association any
173 time, it is recommended to call clif_vsievt periodically to check for
174 disassociate event messages from lldpad(8).
175 If the functions fails it returns
177 -EINVAL
179 No attachment to lldpad(8) or wait is negative.
180 -EAGAIN
182 No message was received during the wait.
183 -EIO Message was received but could not be read.
185 -EBADF Message was received but was not an event message.
187 clif_vsiwait
189 This function combines clif_vsi and clif_vsievt into one function call.
190
192 Code sample to create an VSI association on eth0:
193 char ok[MAX_CLIF_MSGBUF];
195 int rc;
196 size_t ok_len = sizeof(ok);
197 char *cmd ="assoc,blabla,12345,1,00000000-1111-2222-3333-aabbccddeeff"
198 ",none,10-aa:bb:00:00:00:10,11-aa:bb:00:00:00:11";
199 struct clif *tool_conn = clif_open();
200 if (!tool_conn) {
202 fprintf(stderr, "%s can not open connection to LLDPAD0,
203 progname);
204 exit(5);
205 }
206 /* Attach to the vdp22 module */
208 if (clif_attach(tool_conn, "80c4")) {
209 fprintf(stderr, "%s can not attach to LLDPAD0, progname);
210 clif_close(tool_conn);
211 tool_conn = NULL;
212 exit(5);
213 }
214 rc = clif_vsiwait(tool_conn, "eth0", 1, cmd, ok, &ok_len, 5);
216 if (!rc) {
217 /* Parse the response in ok */
218 ....
219 }
220 clif_detach(tool_conn));
221 clif_close(tool_conn);
222
224 lldptool-vdp(8), lldptool-evb(8), lldptool-evb22(8), lldptool(8), lld‐
225 pad(8)
226 IEEE 802.1Qbg (http://www.ieee802.org/1/pages/802.1bg.html)
227
229 Thomas Richter
230open-lldp February 2014 liblldp_clif(3)