package/libnl-tiny/src/genl_ctrl.c

   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 /** @} */