[2/4] resolv: fix nsaddr_list array indexing
Commit Message
This commit is basically a revert of commits 6f5c3117 and 16b7dc27.
Those commits changed the indexing of nsaddr_list array when reading
resolv.conf, with the goal to simplify the mapping between the
nsaddr_list and nsaddrs, by making sure we don't have any name server at
the same both arrays. However the code in __libc_res_nsend hasn't been
updated, and still assume that all nsaddr_list entries are located at
the beginning of the array, without any gap. This causes some issues
when IPv6 name servers are in use.
2014-06-13 Aurelien Jarno <aurelien@aurel32.net>
[BZ #17053]
* resolv/res_init.c (__res_vinit): Fill in IPv4 name server
information using the nserv index. Only count IPv4 name servers
in statp->nscount.
Comments
On Fri, Jun 13, 2014 at 05:32:11PM +0200, Aurelien Jarno wrote:
> This commit is basically a revert of commits 6f5c3117 and 16b7dc27.
> Those commits changed the indexing of nsaddr_list array when reading
> resolv.conf, with the goal to simplify the mapping between the
> nsaddr_list and nsaddrs, by making sure we don't have any name server at
> the same both arrays. However the code in __libc_res_nsend hasn't been
> updated, and still assume that all nsaddr_list entries are located at
> the beginning of the array, without any gap. This causes some issues
> when IPv6 name servers are in use.
>
> 2014-06-13 Aurelien Jarno <aurelien@aurel32.net>
>
> [BZ #17053]
> * resolv/res_init.c (__res_vinit): Fill in IPv4 name server
> information using the nserv index. Only count IPv4 name servers
> in statp->nscount.
Looks good to me.
Siddhesh
>
> diff --git a/resolv/res_init.c b/resolv/res_init.c
> index bdec4d9..37004ab 100644
> --- a/resolv/res_init.c
> +++ b/resolv/res_init.c
> @@ -308,9 +308,9 @@ __res_vinit(res_state statp, int preinit) {
> cp++;
> if ((*cp != '\0') && (*cp != '\n')
> && __inet_aton(cp, &a)) {
> - statp->nsaddr_list[nservall].sin_addr = a;
> - statp->nsaddr_list[nservall].sin_family = AF_INET;
> - statp->nsaddr_list[nservall].sin_port =
> + statp->nsaddr_list[nserv].sin_addr = a;
> + statp->nsaddr_list[nserv].sin_family = AF_INET;
> + statp->nsaddr_list[nserv].sin_port =
> htons(NAMESERVER_PORT);
> nserv++;
> #ifdef _LIBC
> @@ -414,7 +414,7 @@ __res_vinit(res_state statp, int preinit) {
> continue;
> }
> }
> - statp->nscount = nservall;
> + statp->nscount = nserv;
> #ifdef _LIBC
> if (nservall - nserv > 0) {
> statp->_u._ext.nscount6 = nservall - nserv;
> --
> 2.0.0
>
On Thu, Jun 19, 2014 at 7:56 PM, Siddhesh Poyarekar <siddhesh@redhat.com> wrote:
> On Fri, Jun 13, 2014 at 05:32:11PM +0200, Aurelien Jarno wrote:
>> This commit is basically a revert of commits 6f5c3117 and 16b7dc27.
>> Those commits changed the indexing of nsaddr_list array when reading
>> resolv.conf, with the goal to simplify the mapping between the
>> nsaddr_list and nsaddrs, by making sure we don't have any name server at
>> the same both arrays. However the code in __libc_res_nsend hasn't been
>> updated, and still assume that all nsaddr_list entries are located at
>> the beginning of the array, without any gap. This causes some issues
>> when IPv6 name servers are in use.
>>
>> 2014-06-13 Aurelien Jarno <aurelien@aurel32.net>
>>
>> [BZ #17053]
>> * resolv/res_init.c (__res_vinit): Fill in IPv4 name server
>> information using the nserv index. Only count IPv4 name servers
>> in statp->nscount.
>
> Looks good to me.
>
> Siddhesh
>
>>
>> diff --git a/resolv/res_init.c b/resolv/res_init.c
>> index bdec4d9..37004ab 100644
>> --- a/resolv/res_init.c
>> +++ b/resolv/res_init.c
>> @@ -308,9 +308,9 @@ __res_vinit(res_state statp, int preinit) {
>> cp++;
>> if ((*cp != '\0') && (*cp != '\n')
>> && __inet_aton(cp, &a)) {
>> - statp->nsaddr_list[nservall].sin_addr = a;
>> - statp->nsaddr_list[nservall].sin_family = AF_INET;
>> - statp->nsaddr_list[nservall].sin_port =
>> + statp->nsaddr_list[nserv].sin_addr = a;
>> + statp->nsaddr_list[nserv].sin_family = AF_INET;
>> + statp->nsaddr_list[nserv].sin_port =
>> htons(NAMESERVER_PORT);
>> nserv++;
>> #ifdef _LIBC
>> @@ -414,7 +414,7 @@ __res_vinit(res_state statp, int preinit) {
>> continue;
>> }
>> }
>> - statp->nscount = nservall;
>> + statp->nscount = nserv;
>> #ifdef _LIBC
>> if (nservall - nserv > 0) {
>> statp->_u._ext.nscount6 = nservall - nserv;
>> --
>> 2.0.0
>>
There is a concern:
https://lists.debian.org/debian-glibc/2014/08/msg00068.html
@@ -308,9 +308,9 @@ __res_vinit(res_state statp, int preinit) {
cp++;
if ((*cp != '\0') && (*cp != '\n')
&& __inet_aton(cp, &a)) {
- statp->nsaddr_list[nservall].sin_addr = a;
- statp->nsaddr_list[nservall].sin_family = AF_INET;
- statp->nsaddr_list[nservall].sin_port =
+ statp->nsaddr_list[nserv].sin_addr = a;
+ statp->nsaddr_list[nserv].sin_family = AF_INET;
+ statp->nsaddr_list[nserv].sin_port =
htons(NAMESERVER_PORT);
nserv++;
#ifdef _LIBC
@@ -414,7 +414,7 @@ __res_vinit(res_state statp, int preinit) {
continue;
}
}
- statp->nscount = nservall;
+ statp->nscount = nserv;
#ifdef _LIBC
if (nservall - nserv > 0) {
statp->_u._ext.nscount6 = nservall - nserv;