Fixes BZ #15339.
NSS_STATUS_UNAVAIL may mean that a necessary input resource is not
available. This could occur in a number of cases including when the
network is down, system runs out of file descriptors, etc. The
correct differentiator in such a case is the h_errno, which gives the
nature of failure. In case of failures other than a simple 'not
found', we set h_errno as NETDB_INTERNAL and let errno be the
identifier for the exact error.
When glibc is built with --enable-static-nss, the warning that
using NSS symbols requires the nss shared objects to be present
is no longer true, as those symbols are built into libc. Suppress
the warning for those symbols by providing a new macro
(nss_interface_function) for the NSS functions that is defined as
static_link_warning in the normal case, and empty for static NSS.
* sysdeps/posix/getaddrinfo.c (default_scopes): Map RFC 1918
* addresses
to global scope.
* posix/tst-rfc3484.c: Verify 10/8, 172.16/12 and 196.128/16
addresses are in the same scope as 192.0.2/24.
* posix/gai.conf: Document new scope table defaults.
limit
[BZ #14307]
* sysdeps/posix/getaddrinfo.c (gaih_inet): Increase the size of
the temporary buffer used to invoke __gethostbyname2_r,
__gethostbyaddr_r and gethostbyname4_r to make room for struct
host_data / struct gaih_addrtuple.
* resolv/nss_dns/dns-host.c (global scope): Move definition of
implementation constants MAX_NR_ALIASES and MAX_NR_ADDRS to
header file nss/nsswitch.h.
* nss/nsswitch.h (global scope): Add definition of implementation
constants MAX_NR_ALIASES and MAX_NR_ADDRS (moved from
resolv/nss_dns/dns-host.c).
Whenever getaddrinfo needed network interface information it used the
netlink interface to read the information every single time. The
problem is that this information can change at any time.
The patch implements monitoring of the network interfaces through
nscd. If no change is detected the previously read information can
be reused (which is the norm). This timestamp information is also
made available to other processes using the shared memory segment
between nscd and those processes.
getaddrinfo works around the resolver functionality to avoid automatic
IPv6 lookups. The restoring didn't allow for the resolver to set
additional bits in _res.
When not using gethostbyname4 methods we immediately aborted the loop
over the nss modules on the first successful lookup. While this is
almost always what is wanted the nsswitch.conf file allows to select
something different.
ESRCH return value.
(_nss_dns_gethostbyname4_r): Likewise.
* resolv/res_init.c (__res_vinit): Initialize nscount to zero.
* sysdeps/posix/getaddrinfo.c (gaih_inet): In case we use
gethostbyname4_r, we don't have a separate IPv6 status, so copy
the no_data variable.
prototypes.
* include/arpa/nameser_compat.h: Define T_UNSPEC.
* nis/Versions (libnss_nis): Export _nss_nis_gethostbyname4_r.
(libnss_nisplus): Export _nss_nisplus_gethostbyname4_r.
* nis/nss_nis/nis-hosts.c (LINE_PARSER): Change to also handle
af==AF_UNSPEC.
(_nss_nis_gethostbyname4_r): New function.
* nis/nss_nisplus/nisplus-hosts.c (_nss_nisplus_parse_hostent):
Change to also handle af==AF_UNSPEC.
(get_tablename): New function. Use it to avoid duplication.
(_nss_nisplus_gethostbyname4_r): New function.
* nscd/aicache.c (addhstaiX): Use gethostbyname4_r function is
available.
* nss/Versions (libnss_files): Export _nss_files_gethostbyname4_r.
* nss/nss.h: Define struct gaih_addrtuple.
* nss/nss_files/files-hosts.c (LINE_PARSER): Change to also handle
af==AF_UNSPEC.
(_nss_files_gethostbyname4_r): New function.
* resolv/Versions (libnss_dns): Export _nss_dns_gethostbyname4_r.
* resolv/gethnmaddr.c: Adjust __libc_res_nsearch and __libc_res_nquery
calls.
* resolv/res_query.c (__libc_res_nquery): Take two additional
parameters for second answer buffer. Handle type=T_UNSPEC to mean
look up IPv4 and IPv6.
Change all callers.
* resolv/res_send.c (__libc_res_nsend): Take five aditional parameters
for an additional query and answer buffer. Pass to send_vc and
send_dg.
(send_vc): Send possibly two requests and receive two answers.
(send_dg): Likewise.
* resolv/nss_dns/dns-host.c: Adjust calls to __libc_res_nsearch and
__libc_res_nquery.
(_nss_dns_gethostbyname4_r): New function.
(gaih_getanswer_slice): Likewise.
(gaih_getanswer): Likewise.
* resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Adjust
__libc_res_nquery call.
* resolv/nss_dns/dns-network.c (_nss_dns_getnetbyaddr_r): Likewise.
(_nss_dns_getnetbyname_r): Adjust __libc_res_nsearch call.
* sysdeps/posix/getaddrinfo.c: Use gethostbyname4_r function is
available.
