* nonlocal-group.c
* group database for nss_nonlocal proxy
*
- * Copyright © 2007 Anders Kaseorg <andersk@mit.edu>
+ * Copyright © 2007 Anders Kaseorg <andersk@mit.edu> and Tim Abbott
+ * <tabbott@mit.edu>
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
#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"
static service_user *
static service_user *nip = NULL;
if (nip == NULL)
__nss_database_lookup("group_nonlocal", NULL, "", &nip);
-
+
return nip;
}
errno = old_errno;
return NSS_STATUS_TRYAGAIN;
}
- errno = 0;
ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
if (ret != 0) {
*errnop = old_errno;
return status;
}
+enum nss_status
+get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop)
+{
+ enum nss_status status = NSS_STATUS_NOTFOUND;
+ struct group gbuf;
+ struct group *gbufp = &gbuf;
+ int ret, n;
+ int old_errno = errno;
+ int len = MAGIC_LOCAL_GR_BUFLEN;
+ char *buf = malloc(len);
+ if (buf == 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;
+ }
+ grp->gr_passwd = buffer;
+ buffer += n;
+ buflen -= n;
+
+ grp->gr_gid = gbufp->gr_gid;
+
+ if (buflen < sizeof(void *)) {
+ *errnop = ERANGE;
+ status = NSS_STATUS_TRYAGAIN;
+ goto get_local_group_done;
+ }
+ *(void **)buffer = NULL;
+ buffer += sizeof(void *);
+ buflen -= sizeof(void *);
+ }
+ get_local_group_done:
+ free(buf);
+ errno = old_errno;
+ return status;
+}
static service_user *grent_nip = NULL;
static void *grent_fct_start;
int *errnop)
{
enum nss_status status;
+
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
+ (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+ return NSS_STATUS_UNAVAIL;
+
if (grent_nip == NULL) {
status = _nss_nonlocal_setgrent(0);
if (status != NSS_STATUS_SUCCESS)
void *ptr;
} fct;
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
+ (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+ return NSS_STATUS_UNAVAIL;
+
nip = nss_group_nonlocal_database();
if (nip == NULL)
return NSS_STATUS_UNAVAIL;
void *ptr;
} fct;
- if (buflen == MAGIC_LOCAL_GR_BUFLEN)
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
+ (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
return NSS_STATUS_UNAVAIL;
nip = nss_group_nonlocal_database();
int *errnop);
void *ptr;
} fct;
+
+ struct group local_users_group, nonlocal_users_group;
+ gid_t local_users_gid, gid;
+ int is_local = 0;
+ int buflen;
+ char *buffer;
+
+ /* Check that the user is a nonlocal user before adding any groups. */
+ status = check_nonlocal_user(user, errnop);
+ if (status == NSS_STATUS_TRYAGAIN)
+ return status;
+ else if (status != NSS_STATUS_SUCCESS)
+ is_local = 1;
+
+ 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;
+ }
+ status = get_local_group(MAGIC_LOCAL_GROUPNAME,
+ &local_users_group, buffer, buflen, errnop);
+ if (status == NSS_STATUS_SUCCESS) {
+ local_users_gid = local_users_group.gr_gid;
+ } else if (status == NSS_STATUS_TRYAGAIN) {
+ free(buffer);
+ return status;
+ } else {
+ syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
+ 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);
+ if (status == NSS_STATUS_SUCCESS) {
+ gid = nonlocal_users_group.gr_gid;
+ } else if (status == NSS_STATUS_TRYAGAIN) {
+ free(buffer);
+ 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) {
+ int i;
+ for (i = 0; i < *start; ++i)
+ if ((*groupsp)[i] == gid)
+ break;
+ if (i >= *start) {
+ if (*start + 1 > *size) {
+ gid_t *newgroups;
+ long int newsize = 2 * *size;
+ if (limit > 0) {
+ if (*size >= limit)
+ return NSS_STATUS_SUCCESS;
+ if (newsize > limit)
+ newsize = limit;
+ }
+ newgroups = realloc(*groupsp, *size * sizeof((*groupsp)[0]));
+ if (newgroups == NULL) {
+ *errnop = ENOMEM;
+ errno = old_errno;
+ return NSS_STATUS_TRYAGAIN;
+ }
+ *groupsp = newgroups;
+ *size = newsize;
+ }
+ (*groupsp)[(*start)++] = gid;
+ }
+ }
+
+ errno = old_errno;
+
+ if (is_local)
+ return NSS_STATUS_SUCCESS;
+
int in = *start, out = *start, i;
nip = nss_group_nonlocal_database();
if (i < out)
continue;
+ /* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
+ if (local_users_gid == (*groupsp)[in]) {
+ syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
+ user, MAGIC_LOCAL_GROUPNAME);
+ continue;
+ }
+
status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
if (status == NSS_STATUS_SUCCESS) {
(*groupsp)[out++] = (*groupsp)[in];
- } else if (status != NSS_STATUS_NOTFOUND) {
+ } else if (status == NSS_STATUS_TRYAGAIN) {
*start = out;
*errnop = nonlocal_errno;
return status;
andersk / nss_nonlocal.git / blobdiff