[PATCH v2 23/23] nss: Remove old group merge code
Carlos O'Donell
carlos@redhat.com
Tue Mar 24 21:59:57 GMT 2026
On 3/20/26 4:43 PM, Florian Weimer wrote:
LGTM. Nice removal :-)
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> ---
> nss/Makefile | 1 -
> nss/getXXbyYY_r.c | 107 ++-----------------------
> nss/grp-merge.c | 200 ----------------------------------------------
> nss/grp-merge.h | 35 --------
> 4 files changed, 7 insertions(+), 336 deletions(-)
> delete mode 100644 nss/grp-merge.c
> delete mode 100644 nss/grp-merge.h
>
> diff --git a/nss/Makefile b/nss/Makefile
> index 504f573478..36cf9aa63c 100644
> --- a/nss/Makefile
> +++ b/nss/Makefile
> @@ -95,7 +95,6 @@ routines += \
> getgrgid_r \
> getgrnam \
> getgrnam_r \
> - grp-merge \
> initgroups \
> nss_group_members \
> putgrent \
> diff --git a/nss/getXXbyYY_r.c b/nss/getXXbyYY_r.c
> index 9527b6722d..aa262634f9 100644
> --- a/nss/getXXbyYY_r.c
> +++ b/nss/getXXbyYY_r.c
> @@ -126,47 +126,6 @@
> #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) \
> - ({ \
> - if (err) \
> - { \
> - __set_errno (err); \
> - if (err == ERANGE) \
> - status = NSS_STATUS_TRYAGAIN; \
> - else \
> - status = NSS_STATUS_UNAVAIL; \
> - break; \
> - } \
> - })
> -
> /* 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
> @@ -184,12 +143,8 @@ INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
> EXTRA_PARAMS)
> {
> nss_action_list nip;
> - int do_merge = 0;
> - LOOKUP_TYPE mergegrp;
> - char *mergebuf = NULL;
> - char *endptr = NULL;
> void *fct;
> - int no_more, err;
> + int no_more;
> enum nss_status status = NSS_STATUS_UNAVAIL;
> #ifdef USE_NSCD
> int nscd_status;
> @@ -273,66 +228,18 @@ INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
> && 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)
> + /* MERGE is invalid for most databases. */
> + 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;
> + __set_errno (EINVAL);
> + status = NSS_STATUS_UNAVAIL;
> + break;
> }
>
> no_more = __nss_next2 (&nip, REENTRANT_NAME_STRING,
> REENTRANT2_NAME_STRING, &fct, status, 0);
> }
> - free (mergebuf);
> - mergebuf = NULL;
>
> #ifdef HANDLE_DIGITS_DOTS
> done:
> diff --git a/nss/grp-merge.c b/nss/grp-merge.c
> deleted file mode 100644
> index 0a99882097..0000000000
> --- a/nss/grp-merge.c
> +++ /dev/null
> @@ -1,200 +0,0 @@
> -/* Group merging implementation.
> - Copyright (C) 2016-2026 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/>. */
> -
> -#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
> -__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;
> -
> - /* Align for pointers. We can't simply align C because we need to
> - align destbuf[c]. */
> - if ((((uintptr_t)destbuf + c) & (__alignof__(char **) - 1)) != 0)
> - {
> - uintptr_t mis_align = ((uintptr_t)destbuf + c) & (__alignof__(char **) - 1);
> - c += __alignof__(char **) - mis_align;
> - }
> -
> - /* 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
> -__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;
> -
> - /* Align for pointers. We can't simply align C because we need to
> - align savedbuf[c]. */
> - if ((((uintptr_t)savedbuf + c) & (__alignof__(char **) - 1)) != 0)
> - {
> - uintptr_t mis_align = ((uintptr_t)savedbuf + c) & (__alignof__(char **) - 1);
> - c += __alignof__(char **) - mis_align;
> - }
> -
> - /* 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)
> diff --git a/nss/grp-merge.h b/nss/grp-merge.h
> deleted file mode 100644
> index ba985c556e..0000000000
> --- a/nss/grp-merge.h
> +++ /dev/null
> @@ -1,35 +0,0 @@
> -/* Group merging implementation.
> - Copyright (C) 2016-2026 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 _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);
> -
> -/* 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);
> -
> -#endif /* _GRP_MERGE_H */
--
Cheers,
Carlos.
More information about the Libc-alpha
mailing list