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commit ced8f8933673f4efda1d666d26a1a949602035ed
Author: Stephen Gallagher <sgallagh@redhat.com>
Date: Fri Apr 29 22:11:09 2016 -0400
NSS: Implement group merging support.
commit 2413e73c32fc36470885ae548631e081d66f4201
Author: Zack Weinberg <zackw@panix.com>
Date: Mon Jul 18 09:33:21 2016 -0300
Don't install the internal header grp-merge.h
--- glibc-2.17-c758a686/grp/Makefile
+++ glibc-2.17-c758a686/grp/Makefile
@@ -23,7 +23,8 @@
routines := fgetgrent initgroups setgroups \
getgrent getgrgid getgrnam putgrent \
- getgrent_r getgrgid_r getgrnam_r fgetgrent_r
+ getgrent_r getgrgid_r getgrnam_r fgetgrent_r \
+ grp-merge
include ../Makeconfig
--- glibc-2.17-c758a686/grp/Versions
+++ glibc-2.17-c758a686/grp/Versions
@@ -28,4 +28,7 @@
# g*
getgrouplist;
}
+ GLIBC_PRIVATE {
+ __merge_grp; __copy_grp;
+ }
}
--- glibc-2.17-c758a686/grp/getgrgid_r.c
+++ glibc-2.17-c758a686/grp/getgrgid_r.c
@@ -18,6 +18,7 @@
#include <grp.h>
+#include <grp-merge.h>
#define LOOKUP_TYPE struct group
#define FUNCTION_NAME getgrgid
@@ -25,5 +26,7 @@
#define ADD_PARAMS gid_t gid
#define ADD_VARIABLES gid
#define BUFLEN NSS_BUFLEN_GROUP
+#define DEEPCOPY_FN __copy_grp
+#define MERGE_FN __merge_grp
#include <nss/getXXbyYY_r.c>
--- glibc-2.17-c758a686/grp/getgrnam_r.c
+++ glibc-2.17-c758a686/grp/getgrnam_r.c
@@ -18,6 +18,7 @@
#include <grp.h>
+#include <grp-merge.h>
#define LOOKUP_TYPE struct group
#define FUNCTION_NAME getgrnam
@@ -25,4 +26,7 @@
#define ADD_PARAMS const char *name
#define ADD_VARIABLES name
+#define DEEPCOPY_FN __copy_grp
+#define MERGE_FN __merge_grp
+
#include <nss/getXXbyYY_r.c>
--- glibc-2.17-c758a686/grp/grp-merge.c
+++ glibc-2.17-c758a686/grp/grp-merge.c
@@ -0,0 +1,186 @@
+/* Group merging implementation.
+ Copyright (C) 2016 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <grp.h>
+#include <grp-merge.h>
+
+#define BUFCHECK(size) \
+ ({ \
+ do \
+ { \
+ if (c + (size) > buflen) \
+ { \
+ free (members); \
+ return ERANGE; \
+ } \
+ } \
+ while (0); \
+ })
+
+int
+internal_function
+__copy_grp (const struct group srcgrp, const size_t buflen,
+ struct group *destgrp, char *destbuf, char **endptr)
+{
+ size_t i;
+ size_t c = 0;
+ size_t len;
+ size_t memcount;
+ char **members = NULL;
+
+ /* Copy the GID. */
+ destgrp->gr_gid = srcgrp.gr_gid;
+
+ /* Copy the name. */
+ len = strlen (srcgrp.gr_name) + 1;
+ BUFCHECK (len);
+ memcpy (&destbuf[c], srcgrp.gr_name, len);
+ destgrp->gr_name = &destbuf[c];
+ c += len;
+
+ /* Copy the password. */
+ len = strlen (srcgrp.gr_passwd) + 1;
+ BUFCHECK (len);
+ memcpy (&destbuf[c], srcgrp.gr_passwd, len);
+ destgrp->gr_passwd = &destbuf[c];
+ c += len;
+
+ /* Count all of the members. */
+ for (memcount = 0; srcgrp.gr_mem[memcount]; memcount++)
+ ;
+
+ /* Allocate a temporary holding area for the pointers to the member
+ contents, including space for a NULL-terminator. */
+ members = malloc (sizeof (char *) * (memcount + 1));
+ if (members == NULL)
+ return ENOMEM;
+
+ /* Copy all of the group members to destbuf and add a pointer to each of
+ them into the 'members' array. */
+ for (i = 0; srcgrp.gr_mem[i]; i++)
+ {
+ len = strlen (srcgrp.gr_mem[i]) + 1;
+ BUFCHECK (len);
+ memcpy (&destbuf[c], srcgrp.gr_mem[i], len);
+ members[i] = &destbuf[c];
+ c += len;
+ }
+ members[i] = NULL;
+
+ /* Copy the pointers from the members array into the buffer and assign them
+ to the gr_mem member of destgrp. */
+ destgrp->gr_mem = (char **) &destbuf[c];
+ len = sizeof (char *) * (memcount + 1);
+ BUFCHECK (len);
+ memcpy (&destbuf[c], members, len);
+ c += len;
+ free (members);
+ members = NULL;
+
+ /* Save the count of members at the end. */
+ BUFCHECK (sizeof (size_t));
+ memcpy (&destbuf[c], &memcount, sizeof (size_t));
+ c += sizeof (size_t);
+
+ if (endptr)
+ *endptr = destbuf + c;
+ return 0;
+}
+libc_hidden_def (__copy_grp)
+
+/* Check that the name, GID and passwd fields match, then
+ copy in the gr_mem array. */
+int
+internal_function
+__merge_grp (struct group *savedgrp, char *savedbuf, char *savedend,
+ size_t buflen, struct group *mergegrp, char *mergebuf)
+{
+ size_t c, i, len;
+ size_t savedmemcount;
+ size_t memcount;
+ size_t membersize;
+ char **members = NULL;
+
+ /* We only support merging members of groups with identical names and
+ GID values. If we hit this case, we need to overwrite the current
+ buffer with the saved one (which is functionally equivalent to
+ treating the new lookup as NSS_STATUS_NOTFOUND). */
+ if (mergegrp->gr_gid != savedgrp->gr_gid
+ || strcmp (mergegrp->gr_name, savedgrp->gr_name))
+ return __copy_grp (*savedgrp, buflen, mergegrp, mergebuf, NULL);
+
+ /* Get the count of group members from the last sizeof (size_t) bytes in the
+ mergegrp buffer. */
+ savedmemcount = (size_t) *(savedend - sizeof (size_t));
+
+ /* Get the count of new members to add. */
+ for (memcount = 0; mergegrp->gr_mem[memcount]; memcount++)
+ ;
+
+ /* Create a temporary array to hold the pointers to the member values from
+ both the saved and merge groups. */
+ membersize = savedmemcount + memcount + 1;
+ members = malloc (sizeof (char *) * membersize);
+ if (members == NULL)
+ return ENOMEM;
+
+ /* Copy in the existing member pointers from the saved group
+ Note: this is not NULL-terminated yet. */
+ memcpy (members, savedgrp->gr_mem, sizeof (char *) * savedmemcount);
+
+ /* Back up into the savedbuf until we get back to the NULL-terminator of the
+ group member list. (This means walking back savedmemcount + 1 (char *) pointers
+ and the member count value.
+ The value of c is going to be the used length of the buffer backed up by
+ the member count and further backed up by the size of the pointers. */
+ c = savedend - savedbuf
+ - sizeof (size_t)
+ - sizeof (char *) * (savedmemcount + 1);
+
+ /* Add all the new group members, overwriting the old NULL-terminator while
+ adding the new pointers to the temporary array. */
+ for (i = 0; mergegrp->gr_mem[i]; i++)
+ {
+ len = strlen (mergegrp->gr_mem[i]) + 1;
+ BUFCHECK (len);
+ memcpy (&savedbuf[c], mergegrp->gr_mem[i], len);
+ members[savedmemcount + i] = &savedbuf[c];
+ c += len;
+ }
+ /* Add the NULL-terminator. */
+ members[savedmemcount + memcount] = NULL;
+
+ /* Copy the member array back into the buffer after the member list and free
+ the member array. */
+ savedgrp->gr_mem = (char **) &savedbuf[c];
+ len = sizeof (char *) * membersize;
+ BUFCHECK (len);
+ memcpy (&savedbuf[c], members, len);
+ c += len;
+
+ free (members);
+ members = NULL;
+
+ /* Finally, copy the results back into mergebuf, since that's the buffer
+ that we were provided by the caller. */
+ return __copy_grp (*savedgrp, buflen, mergegrp, mergebuf, NULL);
+}
+libc_hidden_def (__merge_grp)
--- glibc-2.17-c758a686/grp/grp-merge.h
+++ glibc-2.17-c758a686/grp/grp-merge.h
@@ -0,0 +1,37 @@
+/* Group merging implementation.
+ Copyright (C) 2016 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
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _GRP_MERGE_H
+#define _GRP_MERGE_H 1
+
+#include <grp.h>
+
+/* Duplicate a grp struct (and its members). When no longer needed, the
+ calling function must free(newbuf). */
+int
+__copy_grp (const struct group srcgrp, const size_t buflen,
+ struct group *destgrp, char *destbuf, char **endptr)
+ internal_function;
+
+/* Merge the member lists of two grp structs together. */
+int
+__merge_grp (struct group *savedgrp, char *savedbuf, char *savedend,
+ size_t buflen, struct group *mergegrp, char *mergebuf)
+ internal_function;
+
+#endif /* _GRP_MERGE_H */
--- glibc-2.17-c758a686/include/grp-merge.h
+++ glibc-2.17-c758a686/include/grp-merge.h
@@ -0,0 +1,7 @@
+#ifndef _GRP_MERGE_H
+#include <grp/grp-merge.h>
+
+libc_hidden_proto (__copy_grp)
+libc_hidden_proto (__merge_grp)
+
+#endif /* _GRP_MERGE_H */
--- glibc-2.17-c758a686/manual/nss.texi
+++ glibc-2.17-c758a686/manual/nss.texi
@@ -180,7 +180,7 @@
The case of the keywords is insignificant. The @var{status}
values are the results of a call to a lookup function of a specific
-service. They mean
+service. They mean:
@ftable @samp
@item success
@@ -204,6 +204,50 @@
@end ftable
@noindent
+The @var{action} values mean:
+
+@ftable @samp
+@item return
+
+If the status matches, stop the lookup process at this service
+specification. If an entry is available, provide it to the application.
+If an error occurred, report it to the application. In case of a prior
+@samp{merge} action, the data is combined with previous lookup results,
+as explained below.
+
+@item continue
+
+If the status matches, proceed with the lookup process at the next
+entry, discarding the result of the current lookup (and any merged
+data). An exception is the @samp{initgroups} database and the
+@samp{success} status, where @samp{continue} acts like @code{merge}
+below.
+
+@item merge
+
+Proceed with the lookup process, retaining the current lookup result.
+This action is useful only with the @samp{success} status. If a
+subsequent service lookup succeeds and has a matching @samp{return}
+specification, the results are merged, the lookup process ends, and the
+merged results are returned to the application. If the following service
+has a matching @samp{merge} action, the lookup process continues,
+retaining the combined data from this and any previous lookups.
+
+After a @code{merge} action, errors from subsequent lookups are ignored,
+and the data gathered so far will be returned.
+
+The @samp{merge} only applies to the @samp{success} status. It is
+currently implemented for the @samp{group} database and its group
+members field, @samp{gr_mem}. If specified for other databases, it
+causes the lookup to fail (if the @var{status} matches).
+
+When processing @samp{merge} for @samp{group} membership, the group GID
+and name must be identical for both entries. If only one or the other is
+a match, the behavior is undefined.
+
+@end ftable
+
+@noindent
If we have a line like
@smallexample
--- glibc-2.17-c758a686/nscd/getgrgid_r.c
+++ glibc-2.17-c758a686/nscd/getgrgid_r.c
@@ -17,6 +17,7 @@
#include <grp.h>
+#include <grp-merge.h>
#define LOOKUP_TYPE struct group
#define FUNCTION_NAME getgrgid
@@ -25,6 +26,9 @@
#define ADD_VARIABLES gid
#define BUFLEN NSS_BUFLEN_GROUP
+#define DEEPCOPY_FN __copy_grp
+#define MERGE_FN __merge_grp
+
/* We are nscd, so we don't want to be talking to ourselves. */
#undef USE_NSCD
--- glibc-2.17-c758a686/nscd/getgrnam_r.c
+++ glibc-2.17-c758a686/nscd/getgrnam_r.c
@@ -17,6 +17,7 @@
#include <grp.h>
+#include <grp-merge.h>
#define LOOKUP_TYPE struct group
#define FUNCTION_NAME getgrnam
@@ -24,6 +25,9 @@
#define ADD_PARAMS const char *name
#define ADD_VARIABLES name
+#define DEEPCOPY_FN __copy_grp
+#define MERGE_FN __merge_grp
+
/* We are nscd, so we don't want to be talking to ourselves. */
#undef USE_NSCD
--- glibc-2.17-c758a686/nss/getXXbyYY_r.c
+++ glibc-2.17-c758a686/nss/getXXbyYY_r.c
@@ -131,6 +131,52 @@
# define AF_VAL AF_INET
#endif
+
+/* Set defaults for merge functions that haven't been defined. */
+#ifndef DEEPCOPY_FN
+static inline int
+__copy_einval (LOOKUP_TYPE a,
+ const size_t b,
+ LOOKUP_TYPE *c,
+ char *d,
+ char **e)
+{
+ return EINVAL;
+}
+# define DEEPCOPY_FN __copy_einval
+#endif
+
+#ifndef MERGE_FN
+static inline int
+__merge_einval (LOOKUP_TYPE *a,
+ char *b,
+ char *c,
+ size_t d,
+ LOOKUP_TYPE *e,
+ char *f)
+{
+ return EINVAL;
+}
+# define MERGE_FN __merge_einval
+#endif
+
+#define CHECK_MERGE(err, status) \
+ ({ \
+ do \
+ { \
+ if (err) \
+ { \
+ __set_errno (err); \
+ if (err == ERANGE) \
+ status = NSS_STATUS_TRYAGAIN; \
+ else \
+ status = NSS_STATUS_UNAVAIL; \
+ break; \
+ } \
+ } \
+ while (0); \
+ })
+
/* Type of the lookup function we need here. */
typedef enum nss_status (*lookup_function) (ADD_PARAMS, LOOKUP_TYPE *, char *,
size_t, int * H_ERRNO_PARM
@@ -152,13 +198,16 @@
static service_user *startp;
static lookup_function start_fct;
service_user *nip;
+ int do_merge = 0;
+ LOOKUP_TYPE mergegrp;
+ char *mergebuf = NULL;
+ char *endptr = NULL;
union
{
lookup_function l;
void *ptr;
} fct;
-
- int no_more;
+ int no_more, err;
enum nss_status status = NSS_STATUS_UNAVAIL;
#ifdef USE_NSCD
int nscd_status;
@@ -278,9 +327,66 @@
&& errno == ERANGE)
break;
+ if (do_merge)
+ {
+
+ if (status == NSS_STATUS_SUCCESS)
+ {
+ /* The previous loop saved a buffer for merging.
+ Perform the merge now. */
+ err = MERGE_FN (&mergegrp, mergebuf, endptr, buflen, resbuf,
+ buffer);
+ CHECK_MERGE (err,status);
+ do_merge = 0;
+ }
+ else
+ {
+ /* If the result wasn't SUCCESS, copy the saved buffer back
+ into the result buffer and set the status back to
+ NSS_STATUS_SUCCESS to match the previous pass through the
+ loop.
+ * If the next action is CONTINUE, it will overwrite the value
+ currently in the buffer and return the new value.
+ * If the next action is RETURN, we'll return the previously-
+ acquired values.
+ * If the next action is MERGE, then it will be added to the
+ buffer saved from the previous source. */
+ err = DEEPCOPY_FN (mergegrp, buflen, resbuf, buffer, NULL);
+ CHECK_MERGE (err, status);
+ status = NSS_STATUS_SUCCESS;
+ }
+ }
+
+ /* If we were are configured to merge this value with the next one,
+ save the current value of the group struct. */
+ if (nss_next_action (nip, status) == NSS_ACTION_MERGE
+ && status == NSS_STATUS_SUCCESS)
+ {
+ /* Copy the current values into a buffer to be merged with the next
+ set of retrieved values. */
+ if (mergebuf == NULL)
+ {
+ /* Only allocate once and reuse it for as many merges as we need
+ to perform. */
+ mergebuf = malloc (buflen);
+ if (mergebuf == NULL)
+ {
+ __set_errno (ENOMEM);
+ status = NSS_STATUS_UNAVAIL;
+ break;
+ }
+ }
+
+ err = DEEPCOPY_FN (*resbuf, buflen, &mergegrp, mergebuf, &endptr);
+ CHECK_MERGE (err, status);
+ do_merge = 1;
+ }
+
no_more = __nss_next2 (&nip, REENTRANT_NAME_STRING,
REENTRANT2_NAME_STRING, &fct.ptr, status, 0);
}
+ free (mergebuf);
+ mergebuf = NULL;
#ifdef HANDLE_DIGITS_DOTS
done:
--- glibc-2.17-c758a686/nss/getnssent_r.c
+++ glibc-2.17-c758a686/nss/getnssent_r.c
@@ -79,7 +79,18 @@
else
status = DL_CALL_FCT (fct.f, (0));
- no_more = __nss_next2 (nip, func_name, NULL, &fct.ptr, status, 0);
+
+ /* This is a special-case. When [SUCCESS=merge] is in play,
+ _nss_next2() will skip to the next database. Due to the
+ implementation of that function, we can't know whether we're
+ in an enumeration or an individual lookup, which behaves
+ differently with regards to merging. We'll treat SUCCESS as
+ an indication to start the enumeration at this database. */
+ if (nss_next_action (*nip, status) == NSS_ACTION_MERGE)
+ no_more = 1;
+ else
+ no_more = __nss_next2 (nip, func_name, NULL, &fct.ptr, status, 0);
+
if (is_last_nip)
*last_nip = *nip;
}
@@ -175,8 +186,18 @@
do
{
- no_more = __nss_next2 (nip, getent_func_name, NULL, &fct.ptr,
- status, 0);
+ /* This is a special-case. When [SUCCESS=merge] is in play,
+ _nss_next2() will skip to the next database. Due to the
+ implementation of that function, we can't know whether we're
+ in an enumeration or an individual lookup, which behaves
+ differently with regards to merging. We'll treat SUCCESS as
+ an indication to return the results here. */
+ if (status == NSS_STATUS_SUCCESS
+ && nss_next_action (*nip, status) == NSS_ACTION_MERGE)
+ no_more = 1;
+ else
+ no_more = __nss_next2 (nip, getent_func_name, NULL, &fct.ptr,
+ status, 0);
if (is_last_nip)
*last_nip = *nip;
--- glibc-2.17-c758a686/nss/nsswitch.c
+++ glibc-2.17-c758a686/nss/nsswitch.c
@@ -712,6 +712,9 @@
else if (line - name == 8
&& __strncasecmp (name, "CONTINUE", 8) == 0)
action = NSS_ACTION_CONTINUE;
+ else if (line - name == 5
+ && __strncasecmp (name, "MERGE", 5) == 0)
+ action = NSS_ACTION_MERGE;
else
goto finish;
--- glibc-2.17-c758a686/nss/nsswitch.h
+++ glibc-2.17-c758a686/nss/nsswitch.h
@@ -32,7 +32,8 @@
typedef enum
{
NSS_ACTION_CONTINUE,
- NSS_ACTION_RETURN
+ NSS_ACTION_RETURN,
+ NSS_ACTION_MERGE
} lookup_actions;