| Message ID | 1402673533-13243-4-git-send-email-aurelien@aurel32.net |
|---|---|
| State | New |
| Headers | show |
On Fri, Jun 13, 2014 at 05:32:12PM +0200, Aurelien Jarno wrote: > statp->nscount contains the number of servers in the statp->nsaddr_list > array, which only contains IPv4 name servers. > > When resolv.conf only contains IPv6 name servers, statp->nscount equals > to 0, which causes the existing code to add a 127.0.0.1 entry. Change > that by checking nservall, contains the number of IPv4 + IPv6 servers > instead. > > The same way __libc_res_nsend exits almost immediately when > statp->nscount considering that no name servers are available, while > IPv6 name servers are actually available. Change that by checking > (statp->nscount + EXT(statp).nscount6) instead. > > Finally in send_dg, the seconds variable is wrongly computed in case of > IPv6 only name servers. Use (statp->nscount + EXT(statp).nscount6) > instead of statp->nscount. > > 2014-06-13 Aurelien Jarno <aurelien@aurel32.net> > > * resolv/res_init.c (__res_vinit): Check for both IPv4 and IPv6 > name servers before adding a localhost name server entry. > * resolv/res_send.c (__libc_res_nsend): Check for both IPv4 and > IPv6 name servers before ignoring the request. > (send_dg): Check for both IPv4 and IPv6 name servers to compute > time for the total operation. You may also have to fix this bit to also account for ipv6 nameservers: ... static void __attribute__ ((section ("__libc_thread_freeres_fn"))) res_thread_freeres (void) { if (_res.nscount == 0) /* Never called res_ninit. */ return; ... Likewise for any other checks in the resolver that may be using only nscount. Siddhesh > > diff --git a/resolv/res_init.c b/resolv/res_init.c > index 37004ab..95564af 100644 > --- a/resolv/res_init.c > +++ b/resolv/res_init.c > @@ -427,7 +427,7 @@ __res_vinit(res_state statp, int preinit) { > #endif > (void) fclose(fp); > } > - if (__builtin_expect(statp->nscount == 0, 0)) { > + if (__builtin_expect(nservall == 0, 0)) { > statp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1); > statp->nsaddr.sin_family = AF_INET; > statp->nsaddr.sin_port = htons(NAMESERVER_PORT); > diff --git a/resolv/res_send.c b/resolv/res_send.c > index af42b8a..82242bd 100644 > --- a/resolv/res_send.c > +++ b/resolv/res_send.c > @@ -347,7 +347,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, > { > int gotsomewhere, terrno, try, v_circuit, resplen, ns, n; > > - if (statp->nscount == 0) { > + if ((statp->nscount + EXT(statp).nscount6) == 0) { > __set_errno (ESRCH); > return (-1); > } > @@ -1013,7 +1013,7 @@ send_dg(res_state statp, > */ > int seconds = (statp->retrans << ns); > if (ns > 0) > - seconds /= statp->nscount; > + seconds /= (statp->nscount + EXT(statp).nscount6); > if (seconds <= 0) > seconds = 1; > bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0; > -- > 2.0.0 >
diff --git a/resolv/res_init.c b/resolv/res_init.c index 37004ab..95564af 100644 --- a/resolv/res_init.c +++ b/resolv/res_init.c @@ -427,7 +427,7 @@ __res_vinit(res_state statp, int preinit) { #endif (void) fclose(fp); } - if (__builtin_expect(statp->nscount == 0, 0)) { + if (__builtin_expect(nservall == 0, 0)) { statp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1); statp->nsaddr.sin_family = AF_INET; statp->nsaddr.sin_port = htons(NAMESERVER_PORT); diff --git a/resolv/res_send.c b/resolv/res_send.c index af42b8a..82242bd 100644 --- a/resolv/res_send.c +++ b/resolv/res_send.c @@ -347,7 +347,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen, { int gotsomewhere, terrno, try, v_circuit, resplen, ns, n; - if (statp->nscount == 0) { + if ((statp->nscount + EXT(statp).nscount6) == 0) { __set_errno (ESRCH); return (-1); } @@ -1013,7 +1013,7 @@ send_dg(res_state statp, */ int seconds = (statp->retrans << ns); if (ns > 0) - seconds /= statp->nscount; + seconds /= (statp->nscount + EXT(statp).nscount6); if (seconds <= 0) seconds = 1; bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0;