101b39b50SAndreas Gruenbacher #include "drbd_wrappers.h" 201b39b50SAndreas Gruenbacher #include <linux/kernel.h> 301b39b50SAndreas Gruenbacher #include <net/netlink.h> 401b39b50SAndreas Gruenbacher #include <linux/drbd_genl_api.h> 501b39b50SAndreas Gruenbacher #include "drbd_nla.h" 601b39b50SAndreas Gruenbacher 701b39b50SAndreas Gruenbacher static int drbd_nla_check_mandatory(int maxtype, struct nlattr *nla) 801b39b50SAndreas Gruenbacher { 901b39b50SAndreas Gruenbacher struct nlattr *head = nla_data(nla); 1001b39b50SAndreas Gruenbacher int len = nla_len(nla); 1101b39b50SAndreas Gruenbacher int rem; 1201b39b50SAndreas Gruenbacher 1301b39b50SAndreas Gruenbacher /* 1401b39b50SAndreas Gruenbacher * validate_nla (called from nla_parse_nested) ignores attributes 1501b39b50SAndreas Gruenbacher * beyond maxtype, and does not understand the DRBD_GENLA_F_MANDATORY flag. 1601b39b50SAndreas Gruenbacher * In order to have it validate attributes with the DRBD_GENLA_F_MANDATORY 1701b39b50SAndreas Gruenbacher * flag set also, check and remove that flag before calling 1801b39b50SAndreas Gruenbacher * nla_parse_nested. 1901b39b50SAndreas Gruenbacher */ 2001b39b50SAndreas Gruenbacher 2101b39b50SAndreas Gruenbacher nla_for_each_attr(nla, head, len, rem) { 2201b39b50SAndreas Gruenbacher if (nla->nla_type & DRBD_GENLA_F_MANDATORY) { 2301b39b50SAndreas Gruenbacher nla->nla_type &= ~DRBD_GENLA_F_MANDATORY; 2401b39b50SAndreas Gruenbacher if (nla_type(nla) > maxtype) 2501b39b50SAndreas Gruenbacher return -EOPNOTSUPP; 2601b39b50SAndreas Gruenbacher } 2701b39b50SAndreas Gruenbacher } 2801b39b50SAndreas Gruenbacher return 0; 2901b39b50SAndreas Gruenbacher } 3001b39b50SAndreas Gruenbacher 3101b39b50SAndreas Gruenbacher int drbd_nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla, 3201b39b50SAndreas Gruenbacher const struct nla_policy *policy) 3301b39b50SAndreas Gruenbacher { 3401b39b50SAndreas Gruenbacher int err; 3501b39b50SAndreas Gruenbacher 3601b39b50SAndreas Gruenbacher err = drbd_nla_check_mandatory(maxtype, nla); 3701b39b50SAndreas Gruenbacher if (!err) 3801b39b50SAndreas Gruenbacher err = nla_parse_nested(tb, maxtype, nla, policy); 3901b39b50SAndreas Gruenbacher 4001b39b50SAndreas Gruenbacher return err; 4101b39b50SAndreas Gruenbacher } 4201b39b50SAndreas Gruenbacher 4301b39b50SAndreas Gruenbacher struct nlattr *drbd_nla_find_nested(int maxtype, struct nlattr *nla, int attrtype) 4401b39b50SAndreas Gruenbacher { 4501b39b50SAndreas Gruenbacher int err; 4601b39b50SAndreas Gruenbacher /* 4701b39b50SAndreas Gruenbacher * If any nested attribute has the DRBD_GENLA_F_MANDATORY flag set and 4801b39b50SAndreas Gruenbacher * we don't know about that attribute, reject all the nested 4901b39b50SAndreas Gruenbacher * attributes. 5001b39b50SAndreas Gruenbacher */ 5101b39b50SAndreas Gruenbacher err = drbd_nla_check_mandatory(maxtype, nla); 5201b39b50SAndreas Gruenbacher if (err) 5301b39b50SAndreas Gruenbacher return ERR_PTR(err); 5401b39b50SAndreas Gruenbacher return nla_find_nested(nla, attrtype); 5501b39b50SAndreas Gruenbacher } 56