X-Git-Url: http://andersk.mit.edu/gitweb/nss_nonlocal.git/blobdiff_plain/cbb0e3ea444ff761b58c8f9355af1dfc631bc64b..775f7dc3865d6ddfa74d88e77c132f78e0667ac9:/nonlocal-group.c diff --git a/nonlocal-group.c b/nonlocal-group.c index fa7fbaf..8ceeb23 100644 --- a/nonlocal-group.c +++ b/nonlocal-group.c @@ -33,12 +33,25 @@ #include #include #include +#include #include #include #include "nsswitch-internal.h" #include "nonlocal.h" +/* + * If the MAGIC_NONLOCAL_GROUPNAME local group exists, then nonlocal + * users will be automatically added to it. Furthermore, if a local + * user is added to this group, then that user will inherit any + * nonlocal gids from a nonlocal user of the same name, as + * supplementary gids. + */ #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users" + +/* + * If the MAGIC_LOCAL_GROUPNAME local group exists, then local users + * will be automatically added to it. + */ #define MAGIC_LOCAL_GROUPNAME "nss-local-users" @@ -279,6 +292,39 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, return check_nonlocal_group(grp->gr_name, grp, errnop); } +static bool +add_group(gid_t group, long int *start, long int *size, gid_t **groupsp, + long int limit, int *errnop, enum nss_status *status) +{ + int i, old_errno = errno; + for (i = 0; i < *start; ++i) + if ((*groupsp)[i] == group) + return true; + if (*start + 1 > *size) { + gid_t *newgroups; + long int newsize = 2 * *size; + if (limit > 0) { + if (*size >= limit) { + *status = NSS_STATUS_SUCCESS; + return false; + } + if (newsize > limit) + newsize = limit; + } + newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0])); + errno = old_errno; + if (newgroups == NULL) { + *errnop = ENOMEM; + *status = NSS_STATUS_TRYAGAIN; + return false; + } + *groupsp = newgroups; + *size = newsize; + } + (*groupsp)[(*start)++] = group; + return true; +} + enum nss_status _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, long int *size, gid_t **groupsp, long int limit, @@ -292,80 +338,83 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, const __typeof__(&_nss_nonlocal_initgroups_dyn) self = NULL; struct group local_users_group, nonlocal_users_group; - gid_t local_users_gid, gid; - int is_local = 0; + bool is_nonlocal = true; char *buffer; - int old_errno; int in, out, i; - /* Check that the user is a nonlocal user before adding any groups. */ + /* Check that the user is a nonlocal user, or a member of the + * MAGIC_NONLOCAL_GROUPNAME group, 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; - - old_errno = errno; - - status = get_local_group(MAGIC_LOCAL_GROUPNAME, - &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) { + if (status == NSS_STATUS_TRYAGAIN) { return status; - } else { - syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", - MAGIC_LOCAL_GROUPNAME); - local_users_gid = -1; - } + } else if (status != NSS_STATUS_SUCCESS) { + is_nonlocal = false; - if (is_local) { - gid = local_users_gid; - } else { - status = get_local_group(MAGIC_NONLOCAL_GROUPNAME, - &nonlocal_users_group, &buffer, errnop); + status = get_local_group(MAGIC_LOCAL_GROUPNAME, + &local_users_group, &buffer, errnop); if (status == NSS_STATUS_SUCCESS) { - gid = nonlocal_users_group.gr_gid; free(buffer); + if (!add_group(local_users_group.gr_gid, start, size, groupsp, + limit, errnop, &status)) + return status; } else if (status == NSS_STATUS_TRYAGAIN) { return status; } else { - syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", - MAGIC_NONLOCAL_GROUPNAME); - gid = -1; + syslog(LOG_WARNING, + "nss_nonlocal: Group %s does not exist locally!", + MAGIC_LOCAL_GROUPNAME); } } - 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; + status = get_local_group(MAGIC_NONLOCAL_GROUPNAME, + &nonlocal_users_group, &buffer, errnop); + if (status == NSS_STATUS_SUCCESS) { + free(buffer); + if (is_nonlocal) { + if (!add_group(nonlocal_users_group.gr_gid, start, size, groupsp, + limit, errnop, &status)) + return status; + } else { + int i; + for (i = 0; i < *start; ++i) { + if ((*groupsp)[i] == nonlocal_users_group.gr_gid) { + is_nonlocal = true; + break; } - newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0])); - errno = old_errno; - if (newgroups == NULL) { - *errnop = ENOMEM; - return NSS_STATUS_TRYAGAIN; + } + + if (is_nonlocal) { + struct passwd pwbuf; + char *buf; + int nonlocal_errno = *errnop; + status = get_nonlocal_passwd(user, &pwbuf, &buf, errnop); + + if (status == NSS_STATUS_SUCCESS) { + nonlocal_errno = *errnop; + status = check_nonlocal_gid(user, pwbuf.pw_gid, + &nonlocal_errno); + free(buf); + } + + if (status == NSS_STATUS_SUCCESS) { + if (!add_group(pwbuf.pw_gid, start, size, groupsp, limit, + errnop, &status)) + return status; + } else if (status == NSS_STATUS_TRYAGAIN) { + *errnop = nonlocal_errno; + return status; } - *groupsp = newgroups; - *size = newsize; } - (*groupsp)[(*start)++] = gid; } + } else if (status == NSS_STATUS_TRYAGAIN) { + if (is_nonlocal) + return status; + } else { + syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", + MAGIC_NONLOCAL_GROUPNAME); } - if (is_local) + if (!is_nonlocal) return NSS_STATUS_SUCCESS; in = out = *start; @@ -385,13 +434,6 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, 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];