[29/30] resolv: Move nss_dns into libc

  No abilist updates are needed because the symbols were GLIBC_PRIVATE.
---
 include/nss_dns.h            | 36 ++++++++++++++++++++++++++
 resolv/Makefile              | 15 +++--------
 resolv/Versions              | 21 ++++++++-------
 resolv/nss_dns/dns-canon.c   |  4 +--
 resolv/nss_dns/dns-host.c    | 50 +++++++++++++++++-------------------
 resolv/nss_dns/dns-network.c | 13 +++++-----
 6 files changed, 82 insertions(+), 57 deletions(-)
 create mode 100644 include/nss_dns.h
  

On 7/8/21 11:07 AM, Florian Weimer via Libc-alpha wrote:
> No abilist updates are needed because the symbols were GLIBC_PRIVATE.

OK for glibc 2.34.

Tested without regression on x86_64 and i686.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

> ---
>  include/nss_dns.h            | 36 ++++++++++++++++++++++++++
>  resolv/Makefile              | 15 +++--------
>  resolv/Versions              | 21 ++++++++-------
>  resolv/nss_dns/dns-canon.c   |  4 +--
>  resolv/nss_dns/dns-host.c    | 50 +++++++++++++++++-------------------
>  resolv/nss_dns/dns-network.c | 13 +++++-----
>  6 files changed, 82 insertions(+), 57 deletions(-)
>  create mode 100644 include/nss_dns.h
> 
> diff --git a/include/nss_dns.h b/include/nss_dns.h
> new file mode 100644
> index 0000000000..63b5853870
> --- /dev/null
> +++ b/include/nss_dns.h
> @@ -0,0 +1,36 @@
> +/* Internal routines for nss_dns.

OK.

> +   Copyright (C) 2021 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef _NSS_DNS_H
> +#define _NSS_DNS_H
> +
> +#include <nss.h>
> +
> +NSS_DECLARE_MODULE_FUNCTIONS (dns)
> +
> +libc_hidden_proto (_nss_dns_getcanonname_r)
> +libc_hidden_proto (_nss_dns_gethostbyname3_r)
> +libc_hidden_proto (_nss_dns_gethostbyname2_r)
> +libc_hidden_proto (_nss_dns_gethostbyname_r)
> +libc_hidden_proto (_nss_dns_gethostbyname4_r)
> +libc_hidden_proto (_nss_dns_gethostbyaddr2_r)
> +libc_hidden_proto (_nss_dns_gethostbyaddr_r)
> +libc_hidden_proto (_nss_dns_getnetbyname_r)
> +libc_hidden_proto (_nss_dns_getnetbyaddr_r)

OK.

> +
> +#endif
> diff --git a/resolv/Makefile b/resolv/Makefile
> index 4ba58dfa96..dd0a98c74f 100644
> --- a/resolv/Makefile
> +++ b/resolv/Makefile
> @@ -31,6 +31,9 @@ routines := \
>    dn_comp \
>    dn_expand \
>    dn_skipname \
> +  dns-canon \
> +  dns-host \
> +  dns-network \

OK. Pull into libc.

>    herror \
>    inet_addr \
>    inet_ntop \
> @@ -175,18 +178,6 @@ libanl-shared-only-routines += libanl-compat
>  subdir-dirs = nss_dns
>  vpath %.c nss_dns
>  
> -libnss_dns-routines := \
> -  dns-canon \
> -  dns-host \
> -  dns-network \
> -  # libnss_dns-routines
> -
> -libnss_dns-inhibit-o	= $(filter-out .os,$(object-suffixes))
> -ifeq ($(build-static-nss),yes)
> -routines                += $(libnss_dns-routines) $(libresolv-routines)
> -static-only-routines    += $(libnss_dns-routines) $(libresolv-routines)
> -endif
> -

OK. Remove libnss_dns-routines.

>  ifeq ($(run-built-tests),yes)
>  ifneq (no,$(PERL))
>  tests-special += $(objpfx)mtrace-tst-leaks.out $(objpfx)mtrace-tst-leaks2.out \
> diff --git a/resolv/Versions b/resolv/Versions
> index f8b7700a1e..0e878d1421 100644
> --- a/resolv/Versions
> +++ b/resolv/Versions
> @@ -124,6 +124,15 @@ libc {
>      __resolv_context_get_preinit;
>      __resolv_context_put;
>      __resp;
> +    _nss_dns_getcanonname_r;
> +    _nss_dns_gethostbyaddr2_r;
> +    _nss_dns_gethostbyaddr_r;
> +    _nss_dns_gethostbyname2_r;
> +    _nss_dns_gethostbyname3_r;
> +    _nss_dns_gethostbyname4_r;
> +    _nss_dns_gethostbyname_r;
> +    _nss_dns_getnetbyaddr_r;
> +    _nss_dns_getnetbyname_r;

OK. New functions.

>    }
>  }
>  
> @@ -215,15 +224,9 @@ libresolv {
>  
>  libnss_dns {
>    GLIBC_PRIVATE {
> -    _nss_dns_getcanonname_r;
> -    _nss_dns_gethostbyaddr2_r;
> -    _nss_dns_gethostbyaddr_r;
> -    _nss_dns_gethostbyname2_r;
> -    _nss_dns_gethostbyname3_r;
> -    _nss_dns_gethostbyname4_r;
> -    _nss_dns_gethostbyname_r;
> -    _nss_dns_getnetbyaddr_r;
> -    _nss_dns_getnetbyname_r;

OK.

> +    # Keep a version node (with a synthesized local: * directive) so that
> +    # __bss_* symbols are hidden on targets that need it.
> +    __libnss_dns_version_placeholder;

OK.

>    }
>  }
>  
> diff --git a/resolv/nss_dns/dns-canon.c b/resolv/nss_dns/dns-canon.c
> index c5718ce3ab..c892170abd 100644
> --- a/resolv/nss_dns/dns-canon.c
> +++ b/resolv/nss_dns/dns-canon.c
> @@ -25,8 +25,7 @@
>  #include <nsswitch.h>
>  #include <resolv/resolv_context.h>
>  #include <resolv/resolv-internal.h>
> -
> -NSS_DECLARE_MODULE_FUNCTIONS (dns)
> +#include <nss_dns.h>

OK. Include nss_dns.h.

>  
>  #if PACKETSZ > 65536
>  # define MAXPACKET	PACKETSZ
> @@ -185,3 +184,4 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
>    __resolv_context_put (ctx);
>    return status;
>  }
> +libc_hidden_def (_nss_dns_getcanonname_r)

OK.

> diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
> index d6a69a602a..7248ade18d 100644
> --- a/resolv/nss_dns/dns-host.c
> +++ b/resolv/nss_dns/dns-host.c
> @@ -82,6 +82,7 @@
>  
>  #include "nsswitch.h"
>  #include <arpa/nameser.h>
> +#include <nss_dns.h>

OK. Include nss_dns.h.

>  
>  #include <resolv/resolv-internal.h>
>  #include <resolv/resolv_context.h>
> @@ -90,8 +91,6 @@
>  #include <resolv/mapv4v6addr.h>
>  #include <resolv/mapv4v6hostent.h>
>  
> -NSS_DECLARE_MODULE_FUNCTIONS (dns)
> -
>  #define RESOLVSORT
>  
>  #if PACKETSZ > 65536
> @@ -169,6 +168,7 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
>    __resolv_context_put (ctx);
>    return status;
>  }
> +libc_hidden_def (_nss_dns_gethostbyname3_r)

OK.

>  
>  static enum nss_status
>  gethostbyname3_context (struct resolv_context *ctx,
> @@ -283,7 +283,7 @@ gethostbyname3_context (struct resolv_context *ctx,
>  static enum nss_status
>  check_name (const char *name, int *h_errnop)
>  {
> -  if (res_hnok (name))
> +  if (__libc_res_hnok (name))
>      return NSS_STATUS_SUCCESS;

OK.

>    *h_errnop = HOST_NOT_FOUND;
>    return NSS_STATUS_NOTFOUND;
> @@ -300,7 +300,7 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
>    return _nss_dns_gethostbyname3_r (name, af, result, buffer, buflen, errnop,
>  				    h_errnop, NULL, NULL);
>  }
> -
> +libc_hidden_def (_nss_dns_gethostbyname2_r)

OK.

>  
>  enum nss_status
>  _nss_dns_gethostbyname_r (const char *name, struct hostent *result,
> @@ -327,7 +327,7 @@ _nss_dns_gethostbyname_r (const char *name, struct hostent *result,
>    __resolv_context_put (ctx);
>    return status;
>  }
> -
> +libc_hidden_def (_nss_dns_gethostbyname_r)

OK.

>  
>  enum nss_status
>  _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
> @@ -419,15 +419,7 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
>    __resolv_context_put (ctx);
>    return status;
>  }
> -
> -
> -extern enum nss_status _nss_dns_gethostbyaddr2_r (const void *addr,
> -						  socklen_t len, int af,
> -						  struct hostent *result,
> -						  char *buffer, size_t buflen,
> -						  int *errnop, int *h_errnop,
> -						  int32_t *ttlp);
> -hidden_proto (_nss_dns_gethostbyaddr2_r)
> +libc_hidden_def (_nss_dns_gethostbyname4_r)

OK.

>  
>  enum nss_status
>  _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
> @@ -568,7 +560,7 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
>    __resolv_context_put (ctx);
>    return NSS_STATUS_SUCCESS;
>  }
> -hidden_def (_nss_dns_gethostbyaddr2_r)
> +libc_hidden_def (_nss_dns_gethostbyaddr2_r)

OK.

>  
>  
>  enum nss_status
> @@ -579,6 +571,7 @@ _nss_dns_gethostbyaddr_r (const void *addr, socklen_t len, int af,
>    return _nss_dns_gethostbyaddr2_r (addr, len, af, result, buffer, buflen,
>  				    errnop, h_errnop, NULL);
>  }
> +libc_hidden_def (_nss_dns_gethostbyaddr_r)

OK.

>  
>  static void
>  addrsort (struct resolv_context *ctx, char **ap, int num)
> @@ -672,10 +665,10 @@ getanswer_r (struct resolv_context *ctx,
>      {
>      case T_A:
>      case T_AAAA:
> -      name_ok = res_hnok;
> +      name_ok = __libc_res_hnok;

OK.

>        break;
>      case T_PTR:
> -      name_ok = res_dnok;
> +      name_ok = __libc_res_dnok;

OK.

>        break;
>      default:
>        *errnop = ENOENT;
> @@ -810,7 +803,8 @@ getanswer_r (struct resolv_context *ctx,
>  
>  	  if (ap >= &host_data->aliases[MAX_NR_ALIASES - 1])
>  	    continue;
> -	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
> +	  n = __libc_dn_expand (answer->buf, end_of_message, cp,
> +				tbuf, sizeof tbuf);

OK.

>  	  if (__glibc_unlikely (n < 0 || (*name_ok) (tbuf) == 0))
>  	    {
>  	      ++had_error;
> @@ -848,8 +842,9 @@ getanswer_r (struct resolv_context *ctx,
>  	  if (ttlp != NULL && ttl < *ttlp)
>  	      *ttlp = ttl;
>  
> -	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
> -	  if (__glibc_unlikely (n < 0 || res_dnok (tbuf) == 0))
> +	  n = __libc_dn_expand (answer->buf, end_of_message, cp,
> +				tbuf, sizeof tbuf);
> +	  if (__glibc_unlikely (n < 0 || __libc_res_dnok (tbuf) == 0))

OK.

>  	    {
>  	      ++had_error;
>  	      continue;
> @@ -881,7 +876,7 @@ getanswer_r (struct resolv_context *ctx,
>        switch (type)
>  	{
>  	case T_PTR:
> -	  if (__glibc_unlikely (strcasecmp (tname, bp) != 0))
> +	  if (__glibc_unlikely (__strcasecmp (tname, bp) != 0))

OK.

>  	    {
>  	      cp += n;
>  	      continue;			/* XXX - had_error++ ? */
> @@ -897,7 +892,7 @@ getanswer_r (struct resolv_context *ctx,
>  	      n = -1;
>  	    }
>  
> -	  if (__glibc_unlikely (n < 0 || res_hnok (bp) == 0))
> +	  if (__glibc_unlikely (n < 0 || __libc_res_hnok (bp) == 0))

OK.

>  	    {
>  	      ++had_error;
>  	      break;
> @@ -911,7 +906,7 @@ getanswer_r (struct resolv_context *ctx,
>  	  return NSS_STATUS_SUCCESS;
>  	case T_A:
>  	case T_AAAA:
> -	  if (__glibc_unlikely (strcasecmp (result->h_name, bp) != 0))
> +	  if (__glibc_unlikely (__strcasecmp (result->h_name, bp) != 0))

OK.

>  	    {
>  	      cp += n;
>  	      continue;			/* XXX - had_error++ ? */
> @@ -1060,7 +1055,7 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
>        *h_errnop = NO_RECOVERY;
>        return NSS_STATUS_UNAVAIL;
>      }
> -  if (__glibc_unlikely (res_hnok (buffer) == 0))
> +  if (__glibc_unlikely (__libc_res_hnok (buffer) == 0))

OK.

>      {
>        errno = EBADMSG;
>        *errnop = EBADMSG;
> @@ -1093,7 +1088,7 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
>  
>  	  n = -1;
>  	}
> -      if (__glibc_unlikely (n < 0 || res_hnok (buffer) == 0))
> +      if (__glibc_unlikely (n < 0 || __libc_res_hnok (buffer) == 0))

OK.

>  	{
>  	  ++had_error;
>  	  continue;
> @@ -1142,8 +1137,9 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
>  	  if (ttlp != NULL && ttl < *ttlp)
>  	      *ttlp = ttl;
>  
> -	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
> -	  if (__glibc_unlikely (n < 0 || res_hnok (tbuf) == 0))
> +	  n = __libc_dn_expand (answer->buf, end_of_message, cp,
> +				tbuf, sizeof tbuf);
> +	  if (__glibc_unlikely (n < 0 || __libc_res_hnok (tbuf) == 0))

OK.

>  	    {
>  	      ++had_error;
>  	      continue;
> diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
> index 801313caec..74b78959c2 100644
> --- a/resolv/nss_dns/dns-network.c
> +++ b/resolv/nss_dns/dns-network.c
> @@ -67,11 +67,10 @@
>  #include "nsswitch.h"
>  #include <arpa/inet.h>
>  #include <arpa/nameser.h>
> +#include <nss_dns.h>

OK. Include nss_dns.h.

>  #include <resolv/resolv-internal.h>
>  #include <resolv/resolv_context.h>
>  
> -NSS_DECLARE_MODULE_FUNCTIONS (dns)
> -
>  /* Maximum number of aliases we allow.  */
>  #define MAX_NR_ALIASES	48
>  
> @@ -152,7 +151,7 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result,
>    __resolv_context_put (ctx);
>    return status;
>  }
> -
> +libc_hidden_def (_nss_dns_getnetbyname_r)

OK.

>  
>  enum nss_status
>  _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
> @@ -246,7 +245,7 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
>    __resolv_context_put (ctx);
>    return status;
>  }
> -
> +libc_hidden_def (_nss_dns_getnetbyaddr_r)

OK.

>  
>  static enum nss_status
>  getanswer_r (const querybuf *answer, int anslen, struct netent *result,
> @@ -347,7 +346,7 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
>  	  n = -1;
>  	}
>  
> -      if (n < 0 || res_dnok (bp) == 0)
> +      if (n < 0 || __libc_res_dnok (bp) == 0)

OK.

>  	break;
>        cp += n;
>  
> @@ -381,7 +380,7 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
>  	      n = -1;
>  	    }
>  
> -	  if (n < 0 || !res_hnok (bp))
> +	  if (n < 0 || !__libc_res_hnok (bp))

OK.

>  	    {
>  	      /* XXX What does this mean?  The original form from bind
>  		 returns NULL. Incrementing cp has no effect in any case.
> @@ -469,7 +468,7 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
>  		    /* If we are out of digits now, there are two cases:
>  		       1. We are done with digits and now see "in-addr.arpa".
>  		       2. This is not the droid we are looking for.  */
> -		    if (!isdigit (*p) && !strcasecmp (p, "in-addr.arpa"))
> +		    if (!isdigit (*p) && !__strcasecmp (p, "in-addr.arpa"))

OK.

>  		      {
>  			result->n_net = val;
>  			return NSS_STATUS_SUCCESS;
>