NSS: Replace exported NSS lookup functions with stubs [BZ #21962]

Commit 384ca551743318bd9c9e24a496d6397f2e3f2a49 from 2007 added this to
nss/XXX-lookup.c:

+#ifndef NO_COMPAT
+int
+internal_function attribute_compat_text_section
+DB_COMPAT_FCT (service_user **ni, const char *fct_name, void **fctp)
+{
+  return DB_LOOKUP_FCT (ni, fct_name, NULL, fctp);
+}
+#endif

That is, it adds a pseudo-compat function with an internal_function
attribute.  The function it was supposed to replace did not have the
attribute:

 extern int DB_LOOKUP_FCT (service_user **ni, const char *fct_name,
-			  void **fctp) internal_function;
+			  const char *fct2_name, void **fctp)
+  internal_function;

This changed the calling convention on i386 for the following
functions in the public ABI:

  __nss_passwd_lookup
  __nss_group_lookup
  __nss_hosts_lookup

This commit replaces the functions with always-failing stubs,
with true compat symbols.  Due to a happy accident, the calling
convention of the stub is identical for the internal_function
and non-internal_function case on i386.

In addition, this commit auto-generates the __nss_*_lookup2
function declarations as part of <nsswitch.h>.

2 files changed, 3 insertions, 11 deletions

diff --git a/sunrpc/netname.c b/sunrpc/netname.c
index 9aee3e4..0dacd1c 100644
--- a/sunrpc/netname.c
+++ b/sunrpc/netname.c
@@ -140,9 +140,6 @@ libc_hidden_nolink_sunrpc (getnetname, GLIBC_2_1)
 /* Type of the lookup function for netname2user.  */
 typedef int (*netname2user_function) (const char netname[MAXNETNAMELEN + 1],
 				      uid_t *, gid_t *, int *, gid_t *);
-/* The lookup function for the first entry of this service.  */
-extern int __nss_publickey_lookup (service_user ** nip, const char *name,
-				   void **fctp) internal_function;
 
 int
 netname2user (const char netname[MAXNETNAMELEN + 1], uid_t * uidp, gid_t * gidp,
@@ -161,7 +158,7 @@ netname2user (const char netname[MAXNETNAMELEN + 1], uid_t * uidp, gid_t * gidp,
 
   if (startp == NULL)
     {
-      no_more = __nss_publickey_lookup (&nip, "netname2user", &fct.ptr);
+      no_more = __nss_publickey_lookup2 (&nip, "netname2user", NULL, &fct.ptr);
       if (no_more)
 	startp = (service_user *) - 1;
       else
diff --git a/sunrpc/publickey.c b/sunrpc/publickey.c
index ca6e430..e7ac854 100644
--- a/sunrpc/publickey.c
+++ b/sunrpc/publickey.c
@@ -31,11 +31,6 @@ typedef int (*public_function) (const char *, char *, int *);
 /* Type of the lookup function for the secret key.  */
 typedef int (*secret_function) (const char *, char *, const char *, int *);
 
-/* The lookup function for the first entry of this service.  */
-extern int __nss_publickey_lookup (service_user **nip, const char *name,
-				   void **fctp) internal_function;
-
-
 int
 getpublickey (const char *name, char *key)
 {
@@ -52,7 +47,7 @@ getpublickey (const char *name, char *key)
 
   if (startp == NULL)
     {
-      no_more = __nss_publickey_lookup (&nip, "getpublickey", &fct.ptr);
+      no_more = __nss_publickey_lookup2 (&nip, "getpublickey", NULL, &fct.ptr);
       if (no_more)
 	startp = (service_user *) -1;
       else
@@ -95,7 +90,7 @@ getsecretkey (const char *name, char *key, const char *passwd)
 
   if (startp == NULL)
     {
-      no_more = __nss_publickey_lookup (&nip, "getsecretkey", &fct.ptr);
+      no_more = __nss_publickey_lookup2 (&nip, "getsecretkey", NULL, &fct.ptr);
       if (no_more)
 	startp = (service_user *) -1;
       else