* 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 "nsswitch-internal.h"
#include "nonlocal.h"
+#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)
static service_user *nip = NULL;
if (nip == NULL)
__nss_database_lookup("group_nonlocal", NULL, "", &nip);
-
+
return nip;
}
-static __thread int local_only = 0;
-
enum nss_status
-local_getgrgid_r(gid_t gid, struct group *grp,
- char *buffer, size_t buflen, int *errnop)
+check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
{
- int old_local_only = local_only;
+ 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;
int old_errno = errno;
- int ret;
- errno = *errnop;
- local_only = 1;
- ret = getgrgid_r(gid, grp, buffer, buflen, &grp);
+ int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
+ char *buf = malloc(buflen);
+ if (buf == NULL) {
+ *errnop = ENOMEM;
+ errno = old_errno;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ 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 {
+ 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)
+ break;
+ } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
- local_only = old_local_only;
- *errnop = errno;
- errno = old_errno;
+ if (status == NSS_STATUS_SUCCESS) {
+ syslog(LOG_WARNING, "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;
+ }
- if (grp != NULL)
- return NSS_STATUS_SUCCESS;
- else if (ret == 0)
- return NSS_STATUS_NOTFOUND;
- else
- return NSS_STATUS_TRYAGAIN;
+ free(buf);
+ return status;
}
enum nss_status
-check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
+get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop)
{
- struct group local_grp;
- int local_errno = errno;
- enum nss_status local_status, status = NSS_STATUS_SUCCESS;
- int local_buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
- char *local_buffer = malloc(local_buflen);
- if (local_buffer == NULL) {
+ 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;
+ struct group gbuf;
+ int n;
+ int old_errno = errno;
+
+ int len = sysconf(_SC_GETGR_R_SIZE_MAX);
+ char *buf = malloc(len);
+ if (buf == NULL) {
*errnop = ENOMEM;
- errno = local_errno;
+ errno = old_errno;
return NSS_STATUS_TRYAGAIN;
}
- local_errno = 0;
- local_status = local_getgrgid_r(gid, &local_grp, local_buffer,
- local_buflen, &local_errno);
- if (local_status == NSS_STATUS_SUCCESS) {
- syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", local_grp.gr_gid, local_grp.gr_name, user);
- status = NSS_STATUS_NOTFOUND;
- } else if (local_status != NSS_STATUS_NOTFOUND &&
- local_status != NSS_STATUS_UNAVAIL) {
- *errnop = local_errno;
- status = local_status;
+
+ 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 {
+ if (fct.l == _nss_nonlocal_getgrnam_r)
+ status = NSS_STATUS_NOTFOUND;
+ else
+ status = DL_CALL_FCT(fct.l, (name, &gbuf, buf, buflen, errnop));
+ if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
+ break;
+ } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
+
+ if (status != NSS_STATUS_SUCCESS)
+ goto get_local_group_done;
+
+ n = snprintf(buffer, buflen, "%s", gbuf.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", gbuf.gr_passwd);
+ if (n < 0 || n >= buflen) {
+ *errnop = ERANGE;
+ status = NSS_STATUS_TRYAGAIN;
+ goto get_local_group_done;
}
- free(local_buffer);
+ grp->gr_passwd = buffer;
+ buffer += n;
+ buflen -= n;
+
+ grp->gr_gid = gbuf.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);
return status;
}
-
static service_user *grent_nip = NULL;
static void *grent_fct_start;
static union {
int *errnop)
{
enum nss_status status;
+
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (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 (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 (local_only == 1)
+ char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+ if (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);
+ 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, newsize * sizeof((*groupsp)[0]));
+ if (newgroups == NULL) {
+ *errnop = ENOMEM;
+ errno = old_errno;
+ return NSS_STATUS_TRYAGAIN;
+ }
+ *groupsp = newgroups;
+ *size = newsize;
+ }
+ (*groupsp)[(*start)++] = gid;
+ }
+ }
+
+ 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;