IP(2) IP(2)
NAME
eipconv, parseip, parseipmask, v4parseip, v4parsecidr,
parseether, myipaddr, myetheraddr, maskip, equivip, defmask,
isv4, v4tov6, v6tov4, nhgetl, nhgets, hnputl, hnputs,
readipifc - Internet protocol
SYNOPSIS
#include <u.h>
#include <libc.h>
#include <ip.h>
int eipconv(void *o, int f1, int f2, int f3, int chr)
ulong parseip(uchar *ipaddr, char *str)
ulong parseipmask(uchar *ipaddr, char *str)
char* v4parseip(uchar *ipaddr, char *str)
ulong v4parsecidr(uchar *addr, uchar *mask, char *str)
int parseether(uchar *eaddr, char *str)
int myetheraddr(uchar *eaddr, char *net)
void maskip(uchar *from, uchar *mask, uchar *to)
int equivip(uchar *ipaddr1, uchar *ipaddr2)
uchar* defmask(uchar *ipaddr)
int isv4(uchar *ipaddr)
void v4tov6(uchar *ipv6, uchar *ipv4)
void v6tov4(uchar *ipv4, uchar *ipv6)
ushort nhgets(void *p)
uint nhgetl(void *p)
void hnputs(void *p, ushort v)
void hnputl(void *p, uint v)
Ipifc* readipifc(char *net, Ipifc *ifc)
uchar IPv4bcast[IPaddrlen];
uchar IPv4allsys[IPaddrlen];
Page 1 Plan 9 (printed 12/26/24)
IP(2) IP(2)
uchar IPv4allrouter[IPaddrlen];
uchar IPallbits[IPaddrlen];
uchar IPnoaddr[IPaddrlen];
uchar v4prefix[IPaddrlen];
DESCRIPTION
These routines are used by Internet Protocol (IP) programs
to manipulate IP and Ethernet addresses. Plan 9, by
default, uses V6 format IP addresses. Since V4 addresses
fit into the V6 space, all IP addresses can be represented.
IP addresses are stored as a string of 16 unsigned chars,
Ethernet addresses as 6 unsigned chars. Either V4 or V6
string representation can be used for IP addresses. For V4
addresses, the representation can be (up to) 4 decimal inte-
gers from 0 to 255 separated by periods. For V6 addresses,
the representation is (up to) 8 hex integers from 0x0 to
0xFFFF separated by colons. Strings of 0 integers can be
elided using two colons. For example, FFFF::1111 is equiva-
lent to FFFF:0:0:0:0:0:0:1111. The string representation
for IP masks is a superset of the address representation.
It includes slash notation that indicates the number of
leading 1 bits in the mask. Thus, a V4 class C mask can be
represented as FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FF00,
255.255.255.0, or /120. The string representation of Ether-
net addresses is exactly 12 hexadecimal digits.
Eipconv is a print(2) formatter for Ethernet (verb E)
addresses, IP V6 (verb I) addresses, IP V4 (verb V)
addresses, and IP V6 (verb M) masks.
Parseip converts a string pointed to by str to a 16-byte IP
address starting at ipaddr. As a concession to backwards
compatibility, if the string is a V4 address, the return
value is an unsigned long integer containing the big-endian
V4 address. If not, the return value is 6. Parseipmask
converts a string pointed to by str to a 6-byte IP mask
starting at ipaddr. It too returns an unsigned long big-
endian V4 address or 6. Both routines return -1 on errors.
V4parseip converts a string pointed to by str to a 4-byte V4
IP address starting at ipaddr.
V4parsecidr converts a string of the form addr/mask, pointed
to by str, to a 4-byte V4 IP address starting at ipaddr and
a 4-byte V4 IP mask starting at mask.
Parseether converts a string pointed to by str to a 6-byte
Ethernet address starting at eaddr. Myetheraddr reads the
Ethernet address string from file net/1/stats and parses it
Page 2 Plan 9 (printed 12/26/24)
IP(2) IP(2)
into eaddr. Both routines return a negative number on
errors.
Maskip places the bit-wise AND of the IP addresses pointed
to by its first two arguments into the buffer pointed to by
the third.
Equivip returns non-zero if the IP addresses pointed to by
its two arguments are equal.
Defmask returns the standard class A, B, or C mask for
ipaddr.
Isv4 returns non-zero if the V6 address is in the V4 space,
that is, if it starts with 0:0:0:0:0:0:FFFF. V4tov6 con-
verts the V4 address, v4ip, to a V6 address and puts the
result in v6ip. V6tov4 converts the V6 address, v6ip, to a
V4 address and puts the result in v4ip.
Hnputs and hnputl are used to store 16-bit and 32-bit inte-
gers into IP big-endian form. Nhgets and nhgetl convert
big-endian 2 and 4 byte quantities into integers.
A number of standard IP addresses in V6 format are also
defined. They are:
IPv4bcast
the V4 broadcast address
IPv4allsys
the V4 all systems multicast address
IPv4allrouter
the V4 all routers multicast address
IPallbits
the V6 all bits on address
IPnoaddr
the V6 null address, all zeros
v4prefix
the IP V6 prefix to all embedded V4 addresses
Readipifc updates the linked list of IP interfaces, ifc,
with those currently configured under mountpoint net,
default /net. The new list is returned. Ipifc is:
typedef struct Ipifc
{
char dev[64];
uchar ip[IPaddrlen];
Page 3 Plan 9 (printed 12/26/24)
IP(2) IP(2)
uchar mask[IPaddrlen];
uchar net[IPaddrlen];
int mtu;
Ipifc *next;
} Ipifc;
Dev contains the first 64 bytes of the device configured
with this interface. Net is ip&mask if the network is mul-
tipoint or the remote address if the network is point to
point.
SOURCE
/sys/src/libip
SEE ALSO
print(2)
Page 4 Plan 9 (printed 12/26/24)