tip.3 - plan9port - [fork] Plan 9 from user space
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tip.3 (7110B)
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1 .TH IP 3
2 .SH NAME
3 eipfmt, parseip, parseipmask, v4parseip, v4parsecidr, parseether, myipaddr, myetheraddr, maskip, equivip, defmask, isv4, v4tov6, v6tov4, nhgetl, nhgets, nhgetv, hnputl, hnputs, hnputv, ptclbsum, readipifc \- Internet protocol
4 .SH SYNOPSIS
5 .B #include <u.h>
6 .br
7 .B #include <libc.h>
8 .br
9 .B #include <ip.h>
10 .PP
11 .B
12 int eipfmt(Fmt*)
13 .PP
14 .B
15 ulong parseip(uchar *ipaddr, char *str)
16 .PP
17 .B
18 ulong parseipmask(uchar *ipaddr, char *str)
19 .PP
20 .B
21 char* v4parseip(uchar *ipaddr, char *str)
22 .PP
23 .B
24 ulong v4parsecidr(uchar *addr, uchar *mask, char *str)
25 .PP
26 .B
27 int parseether(uchar *eaddr, char *str)
28 .PP
29 .B
30 int myetheraddr(uchar *eaddr, char *dev)
31 .PP
32 .B
33 int myipaddr(uchar *ipaddr, char *net)
34 .PP
35 .B
36 void maskip(uchar *from, uchar *mask, uchar *to)
37 .PP
38 .B
39 int equivip(uchar *ipaddr1, uchar *ipaddr2)
40 .PP
41 .B
42 uchar* defmask(uchar *ipaddr)
43 .PP
44 .B
45 int isv4(uchar *ipaddr)
46 .PP
47 .B
48 void v4tov6(uchar *ipv6, uchar *ipv4)
49 .PP
50 .B
51 void v6tov4(uchar *ipv4, uchar *ipv6)
52 .PP
53 .B
54 ushort nhgets(void *p)
55 .PP
56 .B
57 uint nhgetl(void *p)
58 .PP
59 .B
60 uvlong nhgetv(void *p)
61 .PP
62 .B
63 void hnputs(void *p, ushort v)
64 .PP
65 .B
66 void hnputl(void *p, uint v)
67 .PP
68 .B
69 void hnputv(void *p, uvlong v)
70 .PP
71 .B
72 ushort ptclbsum(uchar *a, int n)
73 .PP
74 .B
75 Ipifc* readipifc(char *net, Ipifc *ifc, int index)
76 .PP
77 .B
78 uchar IPv4bcast[IPaddrlen];
79 .PP
80 .B
81 uchar IPv4allsys[IPaddrlen];
82 .PP
83 .B
84 uchar IPv4allrouter[IPaddrlen];
85 .PP
86 .B
87 uchar IPallbits[IPaddrlen];
88 .PP
89 .B
90 uchar IPnoaddr[IPaddrlen];
91 .PP
92 .B
93 uchar v4prefix[IPaddrlen];
94 .SH DESCRIPTION
95 These routines are used by Internet Protocol (IP) programs to
96 manipulate IP and Ethernet addresses.
97 Plan 9, by default, uses V6 format IP addresses. Since V4
98 addresses fit into the V6 space, all IP addresses can be represented.
99 IP addresses are stored as a string of 16
100 .B unsigned
101 .BR chars ,
102 Ethernet
103 addresses as 6
104 .B unsigned
105 .BR chars .
106 Either V4 or V6 string representation can be used for IP addresses.
107 For V4 addresses, the representation can be (up to) 4 decimal
108 integers from 0 to 255 separated by periods.
109 For V6 addresses, the representation is (up to) 8 hex integers
110 from 0x0 to 0xFFFF separated by colons.
111 Strings of 0 integers can be elided using two colons.
112 For example,
113 .B FFFF::1111
114 is equivalent to
115 .BR FFFF:0:0:0:0:0:0:1111 .
116 The string representation for IP masks is a superset of the
117 address representation. It includes slash notation that indicates
118 the number of leading 1 bits in the mask. Thus, a
119 V4 class C mask can be represented as
120 .BR FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FF00 ,
121 .BR 255.255.255.0 ,
122 or
123 .BR /120.
124 The string representation of Ethernet addresses is exactly
125 12 hexadecimal digits.
126 .PP
127 .I Eipfmt
128 is a
129 .MR print (3)
130 formatter for Ethernet (verb
131 .BR E )
132 addresses,
133 IP V6 (verb
134 .BR I )
135 addresses,
136 IP V4 (verb
137 .BR V )
138 addresses,
139 and IP V6 (verb
140 .BR M )
141 masks.
142 .PP
143 .I Parseip
144 converts a string pointed to by
145 .I str
146 to a 16-byte IP address starting at
147 .IR ipaddr .
148 As a concession to backwards compatibility,
149 if the string is a V4 address, the return value
150 is an unsigned long integer containing the big-endian V4 address.
151 If not, the return value is 6.
152 .I Parseipmask
153 converts a string pointed to by
154 .I str
155 to a 6-byte IP mask starting at
156 .IR ipaddr .
157 It too returns an unsigned long big-endian V4 address or 6.
158 Both routines return -1 on errors.
159 .PP
160 .I V4parseip
161 converts a string pointed to by
162 .I str
163 to a 4-byte V4 IP address starting at
164 .IR ipaddr .
165 .PP
166 .I V4parsecidr
167 converts a string of the form
168 addr/mask, pointed to by
169 .IR str ,
170 to a 4-byte V4 IP address starting at
171 .I ipaddr
172 and a 4-byte V4 IP mask starting at
173 .IR mask .
174 .PP
175 .I Myipaddr
176 returns the first valid IP address in
177 the IP stack rooted at
178 .IR net .
179 .PP
180 .I Parseether
181 converts a string pointed to by
182 .I str
183 to a 6-byte Ethernet address starting at
184 .IR eaddr .
185 .I Myetheraddr
186 reads the Ethernet address string from file
187 .IB dev /1/stats
188 and parses it into
189 .IR eaddr .
190 Both routines return a negative number on errors.
191 .PP
192 .I Maskip
193 places the bit-wise AND of the IP addresses pointed
194 to by its first two arguments into the buffer pointed
195 to by the third.
196 .PP
197 .I Equivip
198 returns non-zero if the IP addresses pointed to by its two
199 arguments are equal.
200 .PP
201 .I Defmask
202 returns the standard class A, B, or C mask for
203 .IR ipaddr .
204 .PP
205 .I Isv4
206 returns non-zero if the V6 address is in the V4 space, that is,
207 if it starts with
208 .BR 0:0:0:0:0:0:FFFF .
209 .I V4tov6
210 converts the V4 address,
211 .IR v4ip ,
212 to a V6 address and puts the result in
213 .IR v6ip .
214 .I V6tov4
215 converts the V6 address,
216 .IR v6ip ,
217 to a V4 address and puts the result in
218 .IR v4ip .
219 .PP
220 .IR Hnputs ,
221 .IR hnputl ,
222 and
223 .I hnputv
224 are used to store 16-, 32-, and 64-bit integers into IP big-endian form.
225 .IR Nhgets ,
226 .IR nhgetl ,
227 and
228 .I nhgetv
229 convert big-endian 2-, 4-, and 8-byte quantities into integers.
230 .PP
231 .I Pctlbsum
232 returns the one's complement checksum used in IP protocols, typically invoked as
233 .EX
234 hnputs(hdr->cksum, ~ptclbsum(data, len) & 0xffff);
235 .EE
236 .PP
237 A number of standard IP addresses in V6 format are also defined. They
238 are:
239 .IP \f5IPv4bcast
240 the V4 broadcast address
241 .IP \f5IPv4allsys
242 the V4 all systems multicast address
243 .IP \f5IPv4allrouter
244 the V4 all routers multicast address
245 .IP \f5IPallbits
246 the V6 all bits on address
247 .IP \f5IPnoaddr
248 the V6 null address, all zeros
249 .IP \f5v4prefix
250 the IP V6 prefix to all embedded V4 addresses
251 .PP
252 .I Readipifc
253 returns information about
254 a particular interface (\fIindex\fP >= 0)
255 or all IP interfaces (\fIindex\fP < 0)
256 configured under a
257 mount point
258 .IR net ,
259 default
260 .BR /net .
261 Each interface is described by one
262 .I Ipifc
263 structure which in turn points to a linked list of
264 .IR Iplifc
265 structures describing the addresses assigned
266 to this interface.
267 If the list
268 .IR ifc
269 is supplied,
270 that list is freed.
271 Thus, subsequent calls can be used
272 to free the list returned by the previous call.
273 .I Ipifc
274 is:
275 .PP
276 .EX
277 typedef struct Ipifc
278 {
279 Ipifc *next;
280 Iplifc *lifc; /* local addressses */
281
282 /* per ip interface */
283 int index; /* number of interface in ipifc dir */
284 char dev[64]; /* associated physical device */
285 int mtu; /* max transfer unit */
286
287 long validlt; /* valid life time */
288 long preflt; /* preferred life time */
289 uchar sendra6; /* on == send router adv */
290 uchar recvra6; /* on == rcv router adv */
291
292 ulong pktin; /* packets read */
293 ulong pktout; /* packets written */
294 ulong errin; /* read errors */
295 ulong errout; /* write errors */
296 Ipv6rp rp; /* route advertisement params */
297 } Ipifc;
298 .EE
299 .PP
300 .I Iplifc
301 is:
302 .PP
303 .EX
304 struct Iplifc
305 {
306 Iplifc *next;
307
308 uchar ip[IPaddrlen];
309 uchar mask[IPaddrlen];
310 uchar net[IPaddrlen]; /* ip & mask */
311 ulong preflt; /* preferred lifetime */
312 ulong validlt; /* valid lifetime */
313 };
314 .EE
315 .PP
316 .I Ipv6rp
317 is:
318 struct Ipv6rp
319 {
320 int mflag;
321 int oflag;
322 int maxraint; /* max route adv interval */
323 int minraint; /* min route adv interval */
324 int linkmtu;
325 int reachtime;
326 int rxmitra;
327 int ttl;
328 int routerlt;
329 };
330 .PP
331 .I Dev
332 contains the first 64 bytes of the device configured with this
333 interface.
334 .I Net
335 is
336 .IB ip & mask
337 if the network is multipoint or
338 the remote address if the network is
339 point to point.
340 .SH SOURCE
341 .B \*9/src/libip
342 .SH SEE ALSO
343 .MR print (3)