Re: IPv4 mapped addresses and -4/-6 switches
Mauro Tortonesi [EMAIL PROTECTED] writes:
well, to defend myself, i have to say that nc6 handles the -4 and -6
switches by simply setting the ai_family member of the hints struct
to be passed to getaddrinfo to PF_INET6 and PF_INET respectively,
instead of the PF_UNSPEC default. so, the behaviour of -4 and -6
switches with numeric addresses in nc6 is just a byproduct of this
simple assignement. ;-)
But so does Wget! Take a look at the code:
if (opt.ipv4_only)
hints.ai_family = AF_INET;
else if (opt.ipv6_only)
hints.ai_family = AF_INET6;
else
{
hints.ai_family = AF_UNSPEC;
hints.ai_flags |= AI_ADDRCONFIG;
}
That's why I am surprised at the different behavior.
Re: IPv4 mapped addresses and -4/-6 switches
On Wednesday 20 April 2005 05:12 am, Hrvoje Niksic wrote:
Mauro Tortonesi [EMAIL PROTECTED] writes:
well, to defend myself, i have to say that nc6 handles the -4 and -6
switches by simply setting the ai_family member of the hints struct
to be passed to getaddrinfo to PF_INET6 and PF_INET respectively,
instead of the PF_UNSPEC default. so, the behaviour of -4 and -6
switches with numeric addresses in nc6 is just a byproduct of this
simple assignement. ;-)
But so does Wget! Take a look at the code:
if (opt.ipv4_only)
hints.ai_family = AF_INET;
else if (opt.ipv6_only)
hints.ai_family = AF_INET6;
else
{
hints.ai_family = AF_UNSPEC;
hints.ai_flags |= AI_ADDRCONFIG;
}
That's why I am surprised at the different behavior.
sorry, i forgot to tell you that when the -6 switch is used, nc6 also sets the
IPV6_V6ONLY option for the PF_INET6 socket used in the communication. that's
why IPv4-compatible addresses are rejected.
--
Aequam memento rebus in arduis servare mentem...
Mauro Tortonesi
University of Ferrara - Dept. of Eng.http://www.ing.unife.it
Institute of Human Machine Cognition http://www.ihmc.us
Deep Space 6 - IPv6 for Linuxhttp://www.deepspace6.net
Ferrara Linux User Group http://www.ferrara.linux.it
Re: IPv4 mapped addresses and -4/-6 switches
Mauro Tortonesi [EMAIL PROTECTED] writes: sorry, i forgot to tell you that when the -6 switch is used, nc6 also sets the IPV6_V6ONLY option for the PF_INET6 socket used in the communication. that's why IPv4-compatible addresses are rejected. Should Wget do the same? It seems to make sense to me.
IPv4 mapped addresses and -4/-6 switches
Is this the intended behavior of the -4/-6 switches: $ wget -4 http://\[:::127.0.0.1\] --00:35:50-- http://[:::127.0.0.1]/ = `index.html' failed: Name or service not known. $ wget -6 http://\[:::127.0.0.1\] --00:35:54-- http://[:::127.0.0.1]/ = `index.html' Connecting to :::127.0.0.1:80... connected. ... Should -4/-6 make a better attempt to deal with this, or is the current behavior fine? If the latter is the case, should we document the current behavior? nc6 rejects the second test case: $ nc6 -4 :::127.0.0.1 80 nc6: forward host lookup failed for remote endpoint :::127.0.0.1: Name or service not known $ nc6 -6 :::127.0.0.1 80 nc6: forward lookup returned no usable socket types
Re: IPv4 mapped addresses and -4/-6 switches
On Tuesday 19 April 2005 05:55 pm, Hrvoje Niksic wrote: Is this the intended behavior of the -4/-6 switches: $ wget -4 http://\[:::127.0.0.1\] --00:35:50-- http://[:::127.0.0.1]/ = `index.html' failed: Name or service not known. $ wget -6 http://\[:::127.0.0.1\] --00:35:54-- http://[:::127.0.0.1]/ = `index.html' Connecting to :::127.0.0.1:80... connected. ... Should -4/-6 make a better attempt to deal with this, or is the current behavior fine? If the latter is the case, should we document the current behavior? nc6 rejects the second test case: $ nc6 -4 :::127.0.0.1 80 nc6: forward host lookup failed for remote endpoint :::127.0.0.1: Name or service not known $ nc6 -6 :::127.0.0.1 80 nc6: forward lookup returned no usable socket types well, this is up to us and the semantics we choose for the -4 and -6 switches. theoretically, since an IPv6 connection to :::127.0.0.1 is semantically equivalent to an IPv4 connection to 127.0.0.1, it makes sense to reject IPv4-compatible addresses when using the -6 switch. therefore, if IPv6 support is compiled in, i think we should accept IPv4-compatible addresses when using the -4 switch. anyway, i realize that adopting this policy makes the implementation of the -4 and -6 switches much more complex. so, i don't have any real preference. BTW, IMVHO this is a very low priority issue and can be left for wget 1.11 ;-) -- Aequam memento rebus in arduis servare mentem... Mauro Tortonesi University of Ferrara - Dept. of Eng.http://www.ing.unife.it Institute of Human Machine Cognition http://www.ihmc.us Deep Space 6 - IPv6 for Linuxhttp://www.deepspace6.net Ferrara Linux User Group http://www.ferrara.linux.it
Re: IPv4 mapped addresses and -4/-6 switches
In article [EMAIL PROTECTED] (at Wed, 20 Apr 2005 00:55:42 +0200), Hrvoje Niksic [EMAIL PROTECTED] says: Is this the intended behavior of the -4/-6 switches: $ wget -4 http://\[:::127.0.0.1\] --00:35:50-- http://[:::127.0.0.1]/ = `index.html' failed: Name or service not known. $ wget -6 http://\[:::127.0.0.1\] --00:35:54-- http://[:::127.0.0.1]/ = `index.html' Connecting to :::127.0.0.1:80... connected. ... Should -4/-6 make a better attempt to deal with this, or is the current behavior fine? If the latter is the case, should we document the current behavior? -4/-6 make sense when and only when we use name (instead of address) to connect host. e.g.: wget -4 http://localhost/ (So, it is not necessary at all to do as nc6 does.) -- Hideaki YOSHIFUJI @ USAGI Project [EMAIL PROTECTED] Homepage: http://www.yoshifuji.org/~hideaki/ GPG FP : 9022 65EB 1ECF 3AD1 0BDF 80D8 4807 F894 E062 0EEA
Re: IPv4 mapped addresses and -4/-6 switches
On Tuesday 19 April 2005 09:21 pm, YOSHIFUJI Hideaki / wrote: In article [EMAIL PROTECTED] (at Wed, 20 Apr 2005 00:55:42 +0200), Hrvoje Niksic [EMAIL PROTECTED] says: Is this the intended behavior of the -4/-6 switches: $ wget -4 http://\[:::127.0.0.1\] --00:35:50-- http://[:::127.0.0.1]/ = `index.html' failed: Name or service not known. $ wget -6 http://\[:::127.0.0.1\] --00:35:54-- http://[:::127.0.0.1]/ = `index.html' Connecting to :::127.0.0.1:80... connected. ... Should -4/-6 make a better attempt to deal with this, or is the current behavior fine? If the latter is the case, should we document the current behavior? -4/-6 make sense when and only when we use name (instead of address) to connect host. e.g.: wget -4 http://localhost/ right. (So, it is not necessary at all to do as nc6 does.) well, to defend myself, i have to say that nc6 handles the -4 and -6 switches by simply setting the ai_family member of the hints struct to be passed to getaddrinfo to PF_INET6 and PF_INET respectively, instead of the PF_UNSPEC default. so, the behaviour of -4 and -6 switches with numeric addresses in nc6 is just a byproduct of this simple assignement. ;-) -- Aequam memento rebus in arduis servare mentem... Mauro Tortonesi University of Ferrara - Dept. of Eng.http://www.ing.unife.it Institute of Human Machine Cognition http://www.ihmc.us Deep Space 6 - IPv6 for Linuxhttp://www.deepspace6.net Ferrara Linux User Group http://www.ferrara.linux.it
