From ccab6d8f73a17346862b681250de6f73a6940144 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sat, 20 Jun 2009 20:39:19 -0700 Subject: Fix broken up NIS groups for compat NSS module. The check for the inclusion of a group in the result gave up too early in case of broken-up NIS groups. We now fall back automatically to the slow mode of using getgrent_r. As an optimization, if there is not blacklist we need not perform the check in the first place and therefore can just accept the results of the initgroups_dyn callback. --- nis/nss_compat/compat-initgroups.c | 200 +++++++++++++++++++++++-------------- 1 file changed, 125 insertions(+), 75 deletions(-) (limited to 'nis') diff --git a/nis/nss_compat/compat-initgroups.c b/nis/nss_compat/compat-initgroups.c index 76ca95d..07a3b92 100644 --- a/nis/nss_compat/compat-initgroups.c +++ b/nis/nss_compat/compat-initgroups.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1998-2004, 2006, 2007 Free Software Foundation, Inc. +/* Copyright (C) 1998-2004, 2006, 2007, 2009 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Thorsten Kukuk , 1998. @@ -43,8 +43,10 @@ static enum nss_status (*nss_getgrnam_r) (const char *name, static enum nss_status (*nss_getgrgid_r) (gid_t gid, struct group * grp, char *buffer, size_t buflen, int *errnop); +static enum nss_status (*nss_setgrent) (int stayopen); static enum nss_status (*nss_getgrent_r) (struct group * grp, char *buffer, size_t buflen, int *errnop); +static enum nss_status (*nss_endgrent) (void); /* Protect global state against multiple changers. */ __libc_lock_define_initialized (static, lock) @@ -68,7 +70,9 @@ struct blacklist_t struct ent_t { - bool_t files; + bool files; + bool need_endgrent; + bool skip_initgroups_dyn; FILE *stream; struct blacklist_t blacklist; }; @@ -106,7 +110,9 @@ init_nss_interface (void) nss_initgroups_dyn = __nss_lookup_function (ni, "initgroups_dyn"); nss_getgrnam_r = __nss_lookup_function (ni, "getgrnam_r"); nss_getgrgid_r = __nss_lookup_function (ni, "getgrgid_r"); + nss_setgrent = __nss_lookup_function (ni, "setgrent"); nss_getgrent_r = __nss_lookup_function (ni, "getgrent_r"); + nss_endgrent = __nss_lookup_function (ni, "endgrent"); } __libc_lock_unlock (lock); @@ -117,7 +123,7 @@ internal_setgrent (ent_t *ent) { enum nss_status status = NSS_STATUS_SUCCESS; - ent->files = TRUE; + ent->files = true; if (ni == NULL) init_nss_interface (); @@ -195,54 +201,68 @@ internal_endgrent (ent_t *ent) else ent->blacklist.current = 0; + if (ent->need_endgrent && nss_endgrent != NULL) + nss_endgrent (); + return NSS_STATUS_SUCCESS; } -/* This function checks, if the user is a member of this group and if - yes, add the group id to the list. */ +/* Add new group record. */ static void +add_group (long int *start, long int *size, gid_t **groupsp, long int limit, + gid_t gid) +{ + gid_t *groups = *groupsp; + + /* Matches user. Insert this group. */ + if (__builtin_expect (*start == *size, 0)) + { + /* Need a bigger buffer. */ + gid_t *newgroups; + long int newsize; + + if (limit > 0 && *size == limit) + /* We reached the maximum. */ + return; + + if (limit <= 0) + newsize = 2 * *size; + else + newsize = MIN (limit, 2 * *size); + + newgroups = realloc (groups, newsize * sizeof (*groups)); + if (newgroups == NULL) + return; + *groupsp = groups = newgroups; + *size = newsize; + } + + groups[*start] = gid; + *start += 1; +} + +/* This function checks, if the user is a member of this group and if + yes, add the group id to the list. Return nonzero is we couldn't + handle the group because the user is not in the member list. */ +static int check_and_add_group (const char *user, gid_t group, long int *start, long int *size, gid_t **groupsp, long int limit, struct group *grp) { - gid_t *groups = *groupsp; char **member; /* Don't add main group to list of groups. */ if (grp->gr_gid == group) - return; + return 0; for (member = grp->gr_mem; *member != NULL; ++member) if (strcmp (*member, user) == 0) { - /* Matches user. Insert this group. */ - if (*start == *size) - { - /* Need a bigger buffer. */ - gid_t *newgroups; - long int newsize; - - if (limit > 0 && *size == limit) - /* We reached the maximum. */ - return; - - if (limit <= 0) - newsize = 2 * *size; - else - newsize = MIN (limit, 2 * *size); - - newgroups = realloc (groups, newsize * sizeof (*groups)); - if (newgroups == NULL) - return; - *groupsp = groups = newgroups; - *size = newsize; - } - - groups[*start] = grp->gr_gid; - *start += 1; - - break; + add_group (start, size, groupsp, limit, grp->gr_gid); + return 0; } + + return 1; } /* Get the next group from NSS (+ entry). If the NSS module supports @@ -255,15 +275,10 @@ getgrent_next_nss (ent_t *ent, char *buffer, size_t buflen, const char *user, enum nss_status status; struct group grpbuf; - /* if this module does not support getgrent_r and initgroups_dyn, - abort. We cannot find the needed group entries. */ - if (nss_getgrent_r == NULL && nss_initgroups_dyn == NULL) - return NSS_STATUS_UNAVAIL; - /* Try nss_initgroups_dyn if supported. We also need getgrgid_r. If this function is not supported, step through the whole group database with getgrent_r. */ - if (nss_initgroups_dyn && nss_getgrgid_r) + if (! ent->skip_initgroups_dyn) { long int mystart = 0; long int mysize = limit <= 0 ? *size : limit; @@ -282,39 +297,56 @@ getgrent_next_nss (ent_t *ent, char *buffer, size_t buflen, const char *user, if (nss_initgroups_dyn (user, group, &mystart, &mysize, &mygroups, limit, errnop) == NSS_STATUS_SUCCESS) { - /* A temporary buffer. We use the normal buffer, until we find - an entry, for which this buffer is to small. In this case, we - overwrite the pointer with one to a bigger buffer. */ - char *tmpbuf = buffer; - size_t tmplen = buflen; - int i; - - for (i = 0; i < mystart; i++) + /* If there is no blacklist we can trust the underlying + initgroups implementation. */ + if (ent->blacklist.current <= 1) + for (int i = 0; i < mystart; i++) + add_group (start, size, groupsp, limit, mygroups[i]); + else { - while ((status = nss_getgrgid_r (mygroups[i], &grpbuf, tmpbuf, - tmplen, - errnop)) == NSS_STATUS_TRYAGAIN - && *errnop == ERANGE) - if (tmpbuf == buffer) - { - tmplen *= 2; - tmpbuf = __alloca (tmplen); - } - else - tmpbuf = extend_alloca (tmpbuf, tmplen, 2 * tmplen); - - if (__builtin_expect (status != NSS_STATUS_NOTFOUND, 1)) + /* A temporary buffer. We use the normal buffer, until we find + an entry, for which this buffer is to small. In this case, we + overwrite the pointer with one to a bigger buffer. */ + char *tmpbuf = buffer; + size_t tmplen = buflen; + + for (int i = 0; i < mystart; i++) { - if (__builtin_expect (status != NSS_STATUS_SUCCESS, 0)) + while ((status = nss_getgrgid_r (mygroups[i], &grpbuf, + tmpbuf, tmplen, errnop)) + == NSS_STATUS_TRYAGAIN + && *errnop == ERANGE) + if (tmpbuf == buffer) + { + tmplen *= 2; + tmpbuf = __alloca (tmplen); + } + else + tmpbuf = extend_alloca (tmpbuf, tmplen, 2 * tmplen); + + if (__builtin_expect (status != NSS_STATUS_NOTFOUND, 1)) { - free (mygroups); - return status; + if (__builtin_expect (status != NSS_STATUS_SUCCESS, 0)) + { + free (mygroups); + return status; + } + + if (!in_blacklist (grpbuf.gr_name, + strlen (grpbuf.gr_name), ent) + && check_and_add_group (user, group, start, size, + groupsp, limit, &grpbuf)) + { + if (nss_setgrent != NULL) + { + nss_setgrent (1); + ent->need_endgrent = true; + } + ent->skip_initgroups_dyn = true; + + goto iter; + } } - - if (!in_blacklist (grpbuf.gr_name, - strlen (grpbuf.gr_name), ent)) - check_and_add_group (user, group, start, size, groupsp, - limit, &grpbuf); } } @@ -327,17 +359,21 @@ getgrent_next_nss (ent_t *ent, char *buffer, size_t buflen, const char *user, } /* If we come here, the NSS module does not support initgroups_dyn - and we have to step through the whole list ourself. */ + or we were confronted with a split group. In these cases we have + to step through the whole list ourself. */ + iter: do { if ((status = nss_getgrent_r (&grpbuf, buffer, buflen, errnop)) != NSS_STATUS_SUCCESS) - return status; + break; } while (in_blacklist (grpbuf.gr_name, strlen (grpbuf.gr_name), ent)); - check_and_add_group (user, group, start, size, groupsp, limit, &grpbuf); - return NSS_STATUS_SUCCESS; + if (status == NSS_STATUS_SUCCESS) + check_and_add_group (user, group, start, size, groupsp, limit, &grpbuf); + + return status; } static enum nss_status @@ -435,7 +471,21 @@ internal_getgrent_r (ent_t *ent, char *buffer, size_t buflen, const char *user, /* +:... */ if (grpbuf.gr_name[0] == '+' && grpbuf.gr_name[1] == '\0') { - ent->files = FALSE; + /* If the selected module does not support getgrent_r or + initgroups_dyn, abort. We cannot find the needed group + entries. */ + if (nss_getgrent_r == NULL && nss_initgroups_dyn == NULL) + return NSS_STATUS_UNAVAIL; + + ent->files = false; + + if (nss_initgroups_dyn == NULL && nss_setgrent != NULL) + { + nss_setgrent (1); + ent->need_endgrent = true; + } + ent->skip_initgroups_dyn = true; + return getgrent_next_nss (ent, buffer, buflen, user, group, start, size, groupsp, limit, errnop); } @@ -455,7 +505,7 @@ _nss_compat_initgroups_dyn (const char *user, gid_t group, long int *start, size_t buflen = sysconf (_SC_GETPW_R_SIZE_MAX); char *tmpbuf; enum nss_status status; - ent_t intern = { TRUE, NULL, {NULL, 0, 0} }; + ent_t intern = { true, false, false, NULL, {NULL, 0, 0} }; status = internal_setgrent (&intern); if (status != NSS_STATUS_SUCCESS) -- cgit v1.1