| 1 | /* |
| 2 | * lib/genl/ctrl.c Generic Netlink Controller |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation version 2.1 |
| 7 | * of the License. |
| 8 | * |
| 9 | * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch> |
| 10 | */ |
| 11 | |
| 12 | /** |
| 13 | * @ingroup genl_mngt |
| 14 | * @defgroup ctrl Controller |
| 15 | * @brief |
| 16 | * |
| 17 | * @{ |
| 18 | */ |
| 19 | |
| 20 | #include <netlink-generic.h> |
| 21 | #include <netlink/netlink.h> |
| 22 | #include <netlink/genl/genl.h> |
| 23 | #include <netlink/genl/family.h> |
| 24 | #include <netlink/genl/mngt.h> |
| 25 | #include <netlink/genl/ctrl.h> |
| 26 | #include <netlink/utils.h> |
| 27 | |
| 28 | /** @cond SKIP */ |
| 29 | #define CTRL_VERSION 0x0001 |
| 30 | |
| 31 | static struct nl_cache_ops genl_ctrl_ops; |
| 32 | /** @endcond */ |
| 33 | |
| 34 | static int ctrl_request_update(struct nl_cache *c, struct nl_sock *h) |
| 35 | { |
| 36 | return genl_send_simple(h, GENL_ID_CTRL, CTRL_CMD_GETFAMILY, |
| 37 | CTRL_VERSION, NLM_F_DUMP); |
| 38 | } |
| 39 | |
| 40 | static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = { |
| 41 | [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, |
| 42 | [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_STRING, |
| 43 | .maxlen = GENL_NAMSIZ }, |
| 44 | [CTRL_ATTR_VERSION] = { .type = NLA_U32 }, |
| 45 | [CTRL_ATTR_HDRSIZE] = { .type = NLA_U32 }, |
| 46 | [CTRL_ATTR_MAXATTR] = { .type = NLA_U32 }, |
| 47 | [CTRL_ATTR_OPS] = { .type = NLA_NESTED }, |
| 48 | }; |
| 49 | |
| 50 | static struct nla_policy family_op_policy[CTRL_ATTR_OP_MAX+1] = { |
| 51 | [CTRL_ATTR_OP_ID] = { .type = NLA_U32 }, |
| 52 | [CTRL_ATTR_OP_FLAGS] = { .type = NLA_U32 }, |
| 53 | }; |
| 54 | |
| 55 | static int ctrl_msg_parser(struct nl_cache_ops *ops, struct genl_cmd *cmd, |
| 56 | struct genl_info *info, void *arg) |
| 57 | { |
| 58 | struct genl_family *family; |
| 59 | struct nl_parser_param *pp = arg; |
| 60 | int err; |
| 61 | |
| 62 | family = genl_family_alloc(); |
| 63 | if (family == NULL) { |
| 64 | err = -NLE_NOMEM; |
| 65 | goto errout; |
| 66 | } |
| 67 | |
| 68 | if (info->attrs[CTRL_ATTR_FAMILY_NAME] == NULL) { |
| 69 | err = -NLE_MISSING_ATTR; |
| 70 | goto errout; |
| 71 | } |
| 72 | |
| 73 | if (info->attrs[CTRL_ATTR_FAMILY_ID] == NULL) { |
| 74 | err = -NLE_MISSING_ATTR; |
| 75 | goto errout; |
| 76 | } |
| 77 | |
| 78 | family->ce_msgtype = info->nlh->nlmsg_type; |
| 79 | genl_family_set_id(family, |
| 80 | nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID])); |
| 81 | genl_family_set_name(family, |
| 82 | nla_get_string(info->attrs[CTRL_ATTR_FAMILY_NAME])); |
| 83 | |
| 84 | if (info->attrs[CTRL_ATTR_VERSION]) { |
| 85 | uint32_t version = nla_get_u32(info->attrs[CTRL_ATTR_VERSION]); |
| 86 | genl_family_set_version(family, version); |
| 87 | } |
| 88 | |
| 89 | if (info->attrs[CTRL_ATTR_HDRSIZE]) { |
| 90 | uint32_t hdrsize = nla_get_u32(info->attrs[CTRL_ATTR_HDRSIZE]); |
| 91 | genl_family_set_hdrsize(family, hdrsize); |
| 92 | } |
| 93 | |
| 94 | if (info->attrs[CTRL_ATTR_MAXATTR]) { |
| 95 | uint32_t maxattr = nla_get_u32(info->attrs[CTRL_ATTR_MAXATTR]); |
| 96 | genl_family_set_maxattr(family, maxattr); |
| 97 | } |
| 98 | |
| 99 | if (info->attrs[CTRL_ATTR_OPS]) { |
| 100 | struct nlattr *nla, *nla_ops; |
| 101 | int remaining; |
| 102 | |
| 103 | nla_ops = info->attrs[CTRL_ATTR_OPS]; |
| 104 | nla_for_each_nested(nla, nla_ops, remaining) { |
| 105 | struct nlattr *tb[CTRL_ATTR_OP_MAX+1]; |
| 106 | int flags = 0, id; |
| 107 | |
| 108 | err = nla_parse_nested(tb, CTRL_ATTR_OP_MAX, nla, |
| 109 | family_op_policy); |
| 110 | if (err < 0) |
| 111 | goto errout; |
| 112 | |
| 113 | if (tb[CTRL_ATTR_OP_ID] == NULL) { |
| 114 | err = -NLE_MISSING_ATTR; |
| 115 | goto errout; |
| 116 | } |
| 117 | |
| 118 | id = nla_get_u32(tb[CTRL_ATTR_OP_ID]); |
| 119 | |
| 120 | if (tb[CTRL_ATTR_OP_FLAGS]) |
| 121 | flags = nla_get_u32(tb[CTRL_ATTR_OP_FLAGS]); |
| 122 | |
| 123 | err = genl_family_add_op(family, id, flags); |
| 124 | if (err < 0) |
| 125 | goto errout; |
| 126 | |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | err = pp->pp_cb((struct nl_object *) family, pp); |
| 131 | errout: |
| 132 | genl_family_put(family); |
| 133 | return err; |
| 134 | } |
| 135 | |
| 136 | /** |
| 137 | * @name Cache Management |
| 138 | * @{ |
| 139 | */ |
| 140 | |
| 141 | int genl_ctrl_alloc_cache(struct nl_sock *sock, struct nl_cache **result) |
| 142 | { |
| 143 | return nl_cache_alloc_and_fill(&genl_ctrl_ops, sock, result); |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * Look up generic netlink family by id in the provided cache. |
| 148 | * @arg cache Generic netlink family cache. |
| 149 | * @arg id Family identifier. |
| 150 | * |
| 151 | * Searches through the cache looking for a registered family |
| 152 | * matching the specified identifier. The caller will own a |
| 153 | * reference on the returned object which needs to be given |
| 154 | * back after usage using genl_family_put(). |
| 155 | * |
| 156 | * @return Generic netlink family object or NULL if no match was found. |
| 157 | */ |
| 158 | struct genl_family *genl_ctrl_search(struct nl_cache *cache, int id) |
| 159 | { |
| 160 | struct genl_family *fam; |
| 161 | |
| 162 | if (cache->c_ops != &genl_ctrl_ops) |
| 163 | BUG(); |
| 164 | |
| 165 | nl_list_for_each_entry(fam, &cache->c_items, ce_list) { |
| 166 | if (fam->gf_id == id) { |
| 167 | nl_object_get((struct nl_object *) fam); |
| 168 | return fam; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | return NULL; |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * @name Resolver |
| 177 | * @{ |
| 178 | */ |
| 179 | |
| 180 | /** |
| 181 | * Look up generic netlink family by family name in the provided cache. |
| 182 | * @arg cache Generic netlink family cache. |
| 183 | * @arg name Family name. |
| 184 | * |
| 185 | * Searches through the cache looking for a registered family |
| 186 | * matching the specified name. The caller will own a reference |
| 187 | * on the returned object which needs to be given back after |
| 188 | * usage using genl_family_put(). |
| 189 | * |
| 190 | * @return Generic netlink family object or NULL if no match was found. |
| 191 | */ |
| 192 | struct genl_family *genl_ctrl_search_by_name(struct nl_cache *cache, |
| 193 | const char *name) |
| 194 | { |
| 195 | struct genl_family *fam; |
| 196 | |
| 197 | if (cache->c_ops != &genl_ctrl_ops) |
| 198 | BUG(); |
| 199 | |
| 200 | nl_list_for_each_entry(fam, &cache->c_items, ce_list) { |
| 201 | if (!strcmp(name, fam->gf_name)) { |
| 202 | nl_object_get((struct nl_object *) fam); |
| 203 | return fam; |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | return NULL; |
| 208 | } |
| 209 | |
| 210 | /** @} */ |
| 211 | |
| 212 | /** |
| 213 | * Resolve generic netlink family name to its identifier |
| 214 | * @arg sk Netlink socket. |
| 215 | * @arg name Name of generic netlink family |
| 216 | * |
| 217 | * Resolves the generic netlink family name to its identifer and returns |
| 218 | * it. |
| 219 | * |
| 220 | * @return A positive identifier or a negative error code. |
| 221 | */ |
| 222 | int genl_ctrl_resolve(struct nl_sock *sk, const char *name) |
| 223 | { |
| 224 | struct nl_cache *cache; |
| 225 | struct genl_family *family; |
| 226 | int err; |
| 227 | |
| 228 | if ((err = genl_ctrl_alloc_cache(sk, &cache)) < 0) |
| 229 | return err; |
| 230 | |
| 231 | family = genl_ctrl_search_by_name(cache, name); |
| 232 | if (family == NULL) { |
| 233 | err = -NLE_OBJ_NOTFOUND; |
| 234 | goto errout; |
| 235 | } |
| 236 | |
| 237 | err = genl_family_get_id(family); |
| 238 | genl_family_put(family); |
| 239 | errout: |
| 240 | nl_cache_free(cache); |
| 241 | |
| 242 | return err; |
| 243 | } |
| 244 | |
| 245 | /** @} */ |
| 246 | |
| 247 | static struct genl_cmd genl_cmds[] = { |
| 248 | { |
| 249 | .c_id = CTRL_CMD_NEWFAMILY, |
| 250 | .c_name = "NEWFAMILY" , |
| 251 | .c_maxattr = CTRL_ATTR_MAX, |
| 252 | .c_attr_policy = ctrl_policy, |
| 253 | .c_msg_parser = ctrl_msg_parser, |
| 254 | }, |
| 255 | { |
| 256 | .c_id = CTRL_CMD_DELFAMILY, |
| 257 | .c_name = "DELFAMILY" , |
| 258 | }, |
| 259 | { |
| 260 | .c_id = CTRL_CMD_GETFAMILY, |
| 261 | .c_name = "GETFAMILY" , |
| 262 | }, |
| 263 | { |
| 264 | .c_id = CTRL_CMD_NEWOPS, |
| 265 | .c_name = "NEWOPS" , |
| 266 | }, |
| 267 | { |
| 268 | .c_id = CTRL_CMD_DELOPS, |
| 269 | .c_name = "DELOPS" , |
| 270 | }, |
| 271 | }; |
| 272 | |
| 273 | static struct genl_ops genl_ops = { |
| 274 | .o_cmds = genl_cmds, |
| 275 | .o_ncmds = ARRAY_SIZE(genl_cmds), |
| 276 | }; |
| 277 | |
| 278 | /** @cond SKIP */ |
| 279 | extern struct nl_object_ops genl_family_ops; |
| 280 | /** @endcond */ |
| 281 | |
| 282 | static struct nl_cache_ops genl_ctrl_ops = { |
| 283 | .co_name = "genl/family", |
| 284 | .co_hdrsize = GENL_HDRSIZE(0), |
| 285 | .co_msgtypes = GENL_FAMILY(GENL_ID_CTRL, "nlctrl"), |
| 286 | .co_genl = &genl_ops, |
| 287 | .co_protocol = NETLINK_GENERIC, |
| 288 | .co_request_update = ctrl_request_update, |
| 289 | .co_obj_ops = &genl_family_ops, |
| 290 | }; |
| 291 | |
| 292 | static void __init ctrl_init(void) |
| 293 | { |
| 294 | genl_register(&genl_ctrl_ops); |
| 295 | } |
| 296 | |
| 297 | static void __exit ctrl_exit(void) |
| 298 | { |
| 299 | genl_unregister(&genl_ctrl_ops); |
| 300 | } |
| 301 | |
| 302 | /** @} */ |
| 303 | |
