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libip: prefer v4 over v6 for myipaddr()

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myipaddr() is used in legacy applications that assume a
single ip address per host. so prefer to retun a v4
address over a v6 one.
This commit is contained in:
cinap_lenrek 2019-02-13 18:56:21 +01:00
parent 06912e53e4
commit dc6772fccc
1 changed files with 22 additions and 12 deletions
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34
sys/src/libip/myipaddr.c
View file

@ -21,8 +21,8 @@ static uchar loopback6[IPaddrlen] = {
0, 0, 0, 1
};
// find first ip addr that isn't the friggin loopback address
// unless there are no others
// find first ip that isn't a friggin loopback or
// link-local address. prefer v4 over v6.
int
myipaddr(uchar *ip, char *net)
{
@ -31,29 +31,39 @@ myipaddr(uchar *ip, char *net)
static Ipifc *ifc;
uchar mynet[IPaddrlen];
ipmove(ip, IPnoaddr);
ifc = readipifc(net, ifc, -1);
for(nifc = ifc; nifc; nifc = nifc->next)
for(lifc = nifc->lifc; lifc; lifc = lifc->next){
for(nifc = ifc; nifc != nil; nifc = nifc->next){
for(lifc = nifc->lifc; lifc != nil; lifc = lifc->next){
/* unspecified */
if(ipcmp(lifc->ip, IPnoaddr) == 0)
continue;
if(isv4(lifc->ip)){
/* ipv4 loopback */
maskip(lifc->ip, loopbackmask, mynet);
if(ipcmp(mynet, loopbacknet) == 0)
continue;
ipmove(ip, lifc->ip);
return 0;
}
/* already got a v6 address? */
if(ipcmp(ip, IPnoaddr) != 0)
continue;
/* ipv6 loopback */
if(ipcmp(lifc->ip, loopback6) == 0)
continue;
/* ipv4 loopback */
maskip(lifc->ip, loopbackmask, mynet);
if(ipcmp(mynet, loopbacknet) == 0)
continue;
/* ipv6 linklocal */
if(ISIPV6LINKLOCAL(lifc->ip))
continue;
/* save first v6 address */
ipmove(ip, lifc->ip);
return 0;
}
ipmove(ip, IPnoaddr);
return -1;
}
return ipcmp(ip, IPnoaddr) != 0 ? 0 : -1;
}