X-Git-Url: http://andersk.mit.edu/gitweb/nss_nonlocal.git/blobdiff_plain/5879a6964b6eb2e8e53e833623f91017b94859b1..e40bea7ed12613f7442023989bfc5e75fe242e91:/nonlocal-group.c diff --git a/nonlocal-group.c b/nonlocal-group.c index 05f4d46..c7903bd 100644 --- a/nonlocal-group.c +++ b/nonlocal-group.c @@ -2,28 +2,25 @@ * nonlocal-group.c * group database for nss_nonlocal proxy * - * Copyright © 2007 Anders Kaseorg and Tim Abbott - * + * Copyright © 2007–2010 Anders Kaseorg and Tim + * Abbott * - * Permission is hereby granted, free of charge, to any person - * obtaining a copy of this software and associated documentation - * files (the "Software"), to deal in the Software without - * restriction, including without limitation the rights to use, copy, - * modify, merge, publish, distribute, sublicense, and/or sell copies - * of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: + * This file is part of nss_nonlocal. * - * The above copyright notice and this permission notice shall be - * included in all copies or substantial portions of the Software. + * nss_nonlocal 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 SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, - * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF - * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND - * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS - * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN - * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN - * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE - * SOFTWARE. + * nss_nonlocal 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 nss_nonlocal; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301 USA */ #define _GNU_SOURCE @@ -41,11 +38,19 @@ #include "nsswitch-internal.h" #include "nonlocal.h" -#define MAGIC_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7) #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users" #define MAGIC_LOCAL_GROUPNAME "nss-local-users" +enum nss_status +_nss_nonlocal_getgrnam_r(const char *name, struct group *grp, + char *buffer, size_t buflen, int *errnop); + +enum nss_status +_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, + char *buffer, size_t buflen, int *errnop); + + static service_user * nss_group_nonlocal_database(void) { @@ -60,87 +65,139 @@ nss_group_nonlocal_database(void) enum nss_status check_nonlocal_gid(const char *user, gid_t gid, int *errnop) { - enum nss_status status = NSS_STATUS_SUCCESS; + static const char *fct_name = "getgrgid_r"; + static service_user *startp = NULL; + static void *fct_start = NULL; + enum nss_status status; + service_user *nip; + union { + enum nss_status (*l)(gid_t gid, struct group *grp, + char *buffer, size_t buflen, int *errnop); + void *ptr; + } fct; struct group gbuf; - struct group *gbufp = &gbuf; - int ret; int old_errno = errno; - int buflen = MAGIC_LOCAL_GR_BUFLEN; + + size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX); char *buf = malloc(buflen); if (buf == NULL) { *errnop = ENOMEM; errno = old_errno; return NSS_STATUS_TRYAGAIN; } - ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp); - if (ret != 0) { - *errnop = old_errno; - status = NSS_STATUS_TRYAGAIN; - } else if (gbufp != NULL) { - syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user); + + if (fct_start == NULL && + __nss_group_lookup(&startp, fct_name, &fct_start) != 0) { + free(buf); + return NSS_STATUS_UNAVAIL; + } + nip = startp; + fct.ptr = fct_start; + do { + morebuf: + if (fct.l == _nss_nonlocal_getgrgid_r) + status = NSS_STATUS_NOTFOUND; + else + status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop)); + if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) { + free(buf); + buflen *= 2; + buf = malloc(buflen); + if (buf == NULL) { + *errnop = ENOMEM; + errno = old_errno; + return NSS_STATUS_TRYAGAIN; + } + goto morebuf; + } + } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0); + + if (status == NSS_STATUS_SUCCESS) { + syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user); status = NSS_STATUS_NOTFOUND; + } else if (status != NSS_STATUS_TRYAGAIN) { + status = NSS_STATUS_SUCCESS; } + free(buf); - errno = old_errno; return status; } enum nss_status -get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop) +check_nonlocal_group(const char *user, struct group *grp, int *errnop) { - enum nss_status status = NSS_STATUS_NOTFOUND; - struct group gbuf; - struct group *gbufp = &gbuf; - int ret, n; + enum nss_status status = NSS_STATUS_SUCCESS; int old_errno = errno; - int len = MAGIC_LOCAL_GR_BUFLEN; - char *buf = malloc(len); - if (buf == NULL) { + char *end; + unsigned long gid; + + errno = 0; + gid = strtoul(grp->gr_name, &end, 10); + if (errno == 0 && *end == '\0' && (gid_t)gid == gid) + status = check_nonlocal_gid(user, gid, errnop); + errno = old_errno; + if (status != NSS_STATUS_SUCCESS) + return status; + + return check_nonlocal_gid(user, grp->gr_gid, errnop); +} + +enum nss_status +get_local_group(const char *name, struct group *grp, char **buffer, int *errnop) +{ + static const char *fct_name = "getgrnam_r"; + static service_user *startp = NULL; + static void *fct_start = NULL; + enum nss_status status; + service_user *nip; + union { + enum nss_status (*l)(const char *name, struct group *grp, + char *buffer, size_t buflen, int *errnop); + void *ptr; + } fct; + size_t buflen; + int old_errno = errno; + + buflen = sysconf(_SC_GETGR_R_SIZE_MAX); + *buffer = malloc(buflen); + if (*buffer == NULL) { *errnop = ENOMEM; errno = old_errno; return NSS_STATUS_TRYAGAIN; } - ret = getgrnam_r(name, gbufp, buf, len, &gbufp); - if (ret != 0) { - *errnop = old_errno; - status = NSS_STATUS_TRYAGAIN; - } else if (gbufp != NULL) { - status = NSS_STATUS_SUCCESS; - n = snprintf(buffer, buflen, "%s", gbufp->gr_name); - if (n < 0 || n >= buflen) { - *errnop = ERANGE; - status = NSS_STATUS_TRYAGAIN; - goto get_local_group_done; - } - grp->gr_name = buffer; - buffer += n; - buflen -= n; - - n = snprintf(buffer, buflen, "%s", gbufp->gr_passwd); - if (n < 0 || n >= buflen) { - *errnop = ERANGE; - status = NSS_STATUS_TRYAGAIN; - goto get_local_group_done; + if (fct_start == NULL && + __nss_group_lookup(&startp, fct_name, &fct_start) != 0) { + free(*buffer); + *buffer = NULL; + return NSS_STATUS_UNAVAIL; + } + nip = startp; + fct.ptr = fct_start; + do { + morebuf: + if (fct.l == _nss_nonlocal_getgrnam_r) + status = NSS_STATUS_NOTFOUND; + else + status = DL_CALL_FCT(fct.l, (name, grp, *buffer, buflen, errnop)); + if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) { + free(*buffer); + buflen *= 2; + *buffer = malloc(buflen); + if (*buffer == NULL) { + *errnop = ENOMEM; + errno = old_errno; + return NSS_STATUS_TRYAGAIN; + } + goto morebuf; } - grp->gr_passwd = buffer; - buffer += n; - buflen -= n; - - grp->gr_gid = gbufp->gr_gid; + } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0); - if (buflen < sizeof(void *)) { - *errnop = ERANGE; - status = NSS_STATUS_TRYAGAIN; - goto get_local_group_done; - } - *(void **)buffer = NULL; - buffer += sizeof(void *); - buflen -= sizeof(void *); + if (status != NSS_STATUS_SUCCESS) { + free(*buffer); + *buffer = NULL; } - get_local_group_done: - free(buf); - errno = old_errno; + return status; } @@ -223,8 +280,7 @@ _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen, enum nss_status status; char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); - if (buflen == MAGIC_LOCAL_GR_BUFLEN || - (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')) + if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') return NSS_STATUS_UNAVAIL; if (grent_nip == NULL) { @@ -240,7 +296,7 @@ _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen, do status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop)); while (status == NSS_STATUS_SUCCESS && - check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS); + check_nonlocal_group("(unknown)", grp, &nonlocal_errno) != NSS_STATUS_SUCCESS); } if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) return status; @@ -269,8 +325,7 @@ _nss_nonlocal_getgrnam_r(const char *name, struct group *grp, } fct; char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); - if (buflen == MAGIC_LOCAL_GR_BUFLEN || - (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')) + if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') return NSS_STATUS_UNAVAIL; nip = nss_group_nonlocal_database(); @@ -290,7 +345,12 @@ _nss_nonlocal_getgrnam_r(const char *name, struct group *grp, if (status != NSS_STATUS_SUCCESS) return status; - return check_nonlocal_gid(name, grp->gr_gid, errnop); + if (strcmp(name, grp->gr_name) != 0) { + syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name); + return NSS_STATUS_NOTFOUND; + } + + return check_nonlocal_group(name, grp, errnop); } enum nss_status @@ -308,8 +368,7 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, } fct; char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); - if (buflen == MAGIC_LOCAL_GR_BUFLEN || - (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')) + if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') return NSS_STATUS_UNAVAIL; nip = nss_group_nonlocal_database(); @@ -329,7 +388,12 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, if (status != NSS_STATUS_SUCCESS) return status; - return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop); + if (gid != grp->gr_gid) { + syslog(LOG_ERR, "nss_nonlocal: discarding gid %d from lookup for gid %d\n", grp->gr_gid, gid); + return NSS_STATUS_NOTFOUND; + } + + return check_nonlocal_group(grp->gr_name, grp, errnop); } enum nss_status @@ -351,8 +415,9 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, struct group local_users_group, nonlocal_users_group; gid_t local_users_gid, gid; int is_local = 0; - int buflen; char *buffer; + int old_errno; + int in, out, i; /* Check that the user is a nonlocal user before adding any groups. */ status = check_nonlocal_user(user, errnop); @@ -361,19 +426,13 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, else if (status != NSS_STATUS_SUCCESS) is_local = 1; - int old_errno = errno; + old_errno = errno; - buflen = sysconf(_SC_GETGR_R_SIZE_MAX); - buffer = malloc(buflen); - if (buffer == NULL) { - *errnop = ENOMEM; - errno = old_errno; - return NSS_STATUS_TRYAGAIN; - } status = get_local_group(MAGIC_LOCAL_GROUPNAME, - &local_users_group, buffer, buflen, errnop); + &local_users_group, &buffer, errnop); if (status == NSS_STATUS_SUCCESS) { local_users_gid = local_users_group.gr_gid; + free(buffer); } else if (status == NSS_STATUS_TRYAGAIN) { return status; } else { @@ -381,31 +440,22 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, MAGIC_LOCAL_GROUPNAME); local_users_gid = -1; } - free(buffer); if (is_local) { gid = local_users_gid; } else { - buflen = sysconf(_SC_GETGR_R_SIZE_MAX); - buffer = malloc(buflen); - if (buffer == NULL) { - *errnop = ENOMEM; - errno = old_errno; - return NSS_STATUS_TRYAGAIN; - } status = get_local_group(MAGIC_NONLOCAL_GROUPNAME, - &nonlocal_users_group, buffer, buflen, errnop); + &nonlocal_users_group, &buffer, errnop); if (status == NSS_STATUS_SUCCESS) { gid = nonlocal_users_group.gr_gid; + free(buffer); } else if (status == NSS_STATUS_TRYAGAIN) { - errno = old_errno; return status; } else { syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", MAGIC_NONLOCAL_GROUPNAME); gid = -1; } - free(buffer); } if (gid != -1) { @@ -423,7 +473,7 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, if (newsize > limit) newsize = limit; } - newgroups = realloc(*groupsp, *size * sizeof((*groupsp)[0])); + newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0])); if (newgroups == NULL) { *errnop = ENOMEM; errno = old_errno; @@ -436,12 +486,10 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, } } - errno = old_errno; - if (is_local) return NSS_STATUS_SUCCESS; - int in = *start, out = *start, i; + in = out = *start; nip = nss_group_nonlocal_database(); if (nip == NULL)