diff options
| -rw-r--r-- | lib/genl/ctrl.c | 186 | ||||
| -rw-r--r-- | tests/test-genl.c | 3 |
2 files changed, 146 insertions, 43 deletions
diff --git a/lib/genl/ctrl.c b/lib/genl/ctrl.c index ddb7603..3902f09 100644 --- a/lib/genl/ctrl.c +++ b/lib/genl/ctrl.c @@ -61,6 +61,47 @@ static struct nla_policy family_grp_policy[CTRL_ATTR_MCAST_GRP_MAX+1] = { [CTRL_ATTR_MCAST_GRP_ID] = { .type = NLA_U32 }, }; +static int parse_mcast_grps(struct genl_family *family, struct nlattr *grp_attr) +{ + struct nlattr *nla; + int remaining, err; + + if (!grp_attr) + BUG(); + + nla_for_each_nested(nla, grp_attr, remaining) { + struct nlattr *tb[CTRL_ATTR_MCAST_GRP_MAX+1]; + int id; + const char * name; + + err = nla_parse_nested(tb, CTRL_ATTR_MCAST_GRP_MAX, nla, + family_grp_policy); + if (err < 0) + goto errout; + + if (tb[CTRL_ATTR_MCAST_GRP_ID] == NULL) { + err = -NLE_MISSING_ATTR; + goto errout; + } + id = nla_get_u32(tb[CTRL_ATTR_MCAST_GRP_ID]); + + if (tb[CTRL_ATTR_MCAST_GRP_NAME] == NULL) { + err = -NLE_MISSING_ATTR; + goto errout; + } + name = nla_get_string(tb[CTRL_ATTR_MCAST_GRP_NAME]); + + err = genl_family_add_grp(family, id, name); + if (err < 0) + goto errout; + } + + err = 0; + +errout: + return err; +} + static int ctrl_msg_parser(struct nl_cache_ops *ops, struct genl_cmd *cmd, struct genl_info *info, void *arg) { @@ -137,45 +178,115 @@ static int ctrl_msg_parser(struct nl_cache_ops *ops, struct genl_cmd *cmd, } if (info->attrs[CTRL_ATTR_MCAST_GROUPS]) { - struct nlattr *nla, *nla_grps; - int remaining; + err = parse_mcast_grps(family, info->attrs[CTRL_ATTR_MCAST_GROUPS]); + if (err < 0) + goto errout; + } - nla_grps = info->attrs[CTRL_ATTR_MCAST_GROUPS]; - nla_for_each_nested(nla, nla_grps, remaining) { - struct nlattr *tb[CTRL_ATTR_MCAST_GRP_MAX+1]; - int id; - const char * name; + err = pp->pp_cb((struct nl_object *) family, pp); +errout: + genl_family_put(family); + return err; +} - err = nla_parse_nested(tb, CTRL_ATTR_MCAST_GRP_MAX, nla, - family_grp_policy); - if (err < 0) - goto errout; +/** + * process responses from from the query sent by genl_ctrl_probe_by_name + * @arg nl_msg Returned message. + * @arg name genl_family structure to fill out. + * + * Process returned messages, filling out the missing informatino in the + * genl_family structure + * + * @return Indicator to keep processing frames or not + * + */ +static int probe_response(struct nl_msg *msg, void *arg) +{ + struct nlattr *tb[CTRL_ATTR_MAX+1]; + struct nlmsghdr *nlh = nlmsg_hdr(msg); + struct genl_family *ret = (struct genl_family *)arg; - if (tb[CTRL_ATTR_MCAST_GRP_ID] == NULL) { - err = -NLE_MISSING_ATTR; - goto errout; - } - id = nla_get_u32(tb[CTRL_ATTR_MCAST_GRP_ID]); + if (genlmsg_parse(nlh, 0, tb, CTRL_ATTR_MAX, ctrl_policy)) + return NL_SKIP; - if (tb[CTRL_ATTR_MCAST_GRP_NAME] == NULL) { - err = -NLE_MISSING_ATTR; - goto errout; - } - name = nla_get_string(tb[CTRL_ATTR_MCAST_GRP_NAME]); + if (tb[CTRL_ATTR_FAMILY_ID]) + genl_family_set_id(ret, nla_get_u16(tb[CTRL_ATTR_FAMILY_ID])); - err = genl_family_add_grp(family, id, name); - if (err < 0) - goto errout; - } + if (tb[CTRL_ATTR_MCAST_GROUPS]) + if (parse_mcast_grps(ret, tb[CTRL_ATTR_MCAST_GROUPS]) < 0) + return NL_SKIP; + + return NL_STOP; +} + +/** + * Look up generic netlink family by family name querying the kernel directly + * @arg sk Socket. + * @arg name Family name. + * + * Directly query's the kernel for a given family name. The caller will own a + * reference on the returned object which needsd to be given back after usage + * using genl_family_put. + * + * Note: This API call differs from genl_ctrl_search_by_name in that it querys + * the kernel directly, alowing for module autoload to take place to resolve the + * family request. Using an nl_cache prevents that operation + * + * @return Generic netlink family object or NULL if no match was found. + */ +static struct genl_family *genl_ctrl_probe_by_name(struct nl_sock *sk, const char *name) +{ + struct nl_msg *msg; + struct genl_family *ret = NULL; + struct nl_cb *cb; + int rc; + + ret = genl_family_alloc(); + if (!ret) + goto out; + + genl_family_set_name(ret, name); + + msg = nlmsg_alloc(); + if (!msg) + goto out_fam_free; + if (!(cb = nl_cb_clone(nl_socket_get_cb(sk)))) + goto out_msg_free; + + + genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, GENL_ID_CTRL, + 0, 0, CTRL_CMD_GETFAMILY, 1); + + if (nla_put_string(msg, CTRL_ATTR_FAMILY_NAME, name)) + goto out_cb_free; + + rc = nl_send_auto_complete(sk, msg); + if (rc < 0) + goto out_cb_free; + + nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, probe_response, (void *)ret); + + nl_recvmsgs(sk, cb); + + if (genl_family_get_id(ret) != 0) { + nlmsg_free(msg); + nl_cb_put(cb); + return ret; } - err = pp->pp_cb((struct nl_object *) family, pp); -errout: - genl_family_put(family); - return err; +out_cb_free: + nl_cb_put(cb); +out_msg_free: + nlmsg_free(msg); +out_fam_free: + genl_family_put(ret); + ret = NULL; +out: + return ret; } + /** @endcond */ /** @@ -299,14 +410,10 @@ struct genl_family *genl_ctrl_search_by_name(struct nl_cache *cache, */ int genl_ctrl_resolve(struct nl_sock *sk, const char *name) { - struct nl_cache *cache; struct genl_family *family; int err; - if ((err = genl_ctrl_alloc_cache(sk, &cache)) < 0) - return err; - - family = genl_ctrl_search_by_name(cache, name); + family = genl_ctrl_probe_by_name(sk, name); if (family == NULL) { err = -NLE_OBJ_NOTFOUND; goto errout; @@ -315,8 +422,6 @@ int genl_ctrl_resolve(struct nl_sock *sk, const char *name) err = genl_family_get_id(family); genl_family_put(family); errout: - nl_cache_free(cache); - return err; } @@ -348,14 +453,11 @@ static int genl_ctrl_grp_by_name(const struct genl_family *family, int genl_ctrl_resolve_grp(struct nl_sock *sk, const char *family_name, const char *grp_name) { - struct nl_cache *cache; + struct genl_family *family; int err; - if ((err = genl_ctrl_alloc_cache(sk, &cache)) < 0) - return err; - - family = genl_ctrl_search_by_name(cache, family_name); + family = genl_ctrl_probe_by_name(sk, family_name); if (family == NULL) { err = -NLE_OBJ_NOTFOUND; goto errout; @@ -364,8 +466,6 @@ int genl_ctrl_resolve_grp(struct nl_sock *sk, const char *family_name, err = genl_ctrl_grp_by_name(family, grp_name); genl_family_put(family); errout: - nl_cache_free(cache); - return err; } diff --git a/tests/test-genl.c b/tests/test-genl.c index 63862b3..74aea10 100644 --- a/tests/test-genl.c +++ b/tests/test-genl.c @@ -84,6 +84,9 @@ int main(int argc, char *argv[]) if ((err = genl_ops_resolve(sock, &ops)) < 0) nl_cli_fatal(err, "Unable to resolve family name"); + if (genl_ctrl_resolve(sock, "nlctrl") != GENL_ID_CTRL) + nl_cli_fatal(NLE_INVAL, "Resolving of \"nlctrl\" failed"); + msg = nlmsg_alloc(); if (msg == NULL) nl_cli_fatal(NLE_NOMEM, "Unable to allocate netlink message"); |