genl/ctrl.c

   1 /*
   2  * ctrl.c       generic netlink controller
   3  *
   4  *              This program is free software; you can distribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     J Hadi Salim (hadi@cyberus.ca)
  10  *              Johannes Berg (johannes@sipsolutions.net)
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <fcntl.h>
  17 #include <sys/socket.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <string.h>
  21
  22 #include "utils.h"
  23 #include "genl_utils.h"
  24
  25 #define GENL_MAX_FAM_OPS        256
  26 #define GENL_MAX_FAM_GRPS       256
  27
  28 static int usage(void)
  29 {
  30         fprintf(stderr,"Usage: ctrl <CMD>\n" \
  31                        "CMD   := get <PARMS> | list | monitor\n" \
  32                        "PARMS := name <name> | id <id>\n" \
  33                        "Examples:\n" \
  34                        "\tctrl ls\n" \
  35                        "\tctrl monitor\n" \
  36                        "\tctrl get name foobar\n" \
  37                        "\tctrl get id 0xF\n");
  38         return -1;
  39 }
  40
  41 int genl_ctrl_resolve_family(const char *family)
  42 {
  43         struct rtnl_handle rth;
  44         int ret = 0;
  45         struct {
  46                 struct nlmsghdr         n;
  47                 struct genlmsghdr       g;
  48                 char                    buf[4096];
  49         } req = {
  50                 .n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),
  51                 .n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK,
  52                 .n.nlmsg_type = GENL_ID_CTRL,
  53                 .g.cmd = CTRL_CMD_GETFAMILY,
  54         };
  55         struct nlmsghdr *nlh = &req.n;
  56         struct genlmsghdr *ghdr = &req.g;
  57         struct nlmsghdr *answer = NULL;
  58
  59         if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
  60                 fprintf(stderr, "Cannot open generic netlink socket\n");
  61                 exit(1);
  62         }
  63
  64         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME, family, strlen(family) + 1);
  65
  66         if (rtnl_talk(&rth, nlh, &answer) < 0) {
  67                 fprintf(stderr, "Error talking to the kernel\n");
  68                 goto errout;
  69         }
  70
  71         {
  72                 struct rtattr *tb[CTRL_ATTR_MAX + 1];
  73                 int len = answer->nlmsg_len;
  74                 struct rtattr *attrs;
  75
  76                 if (answer->nlmsg_type !=  GENL_ID_CTRL) {
  77                         fprintf(stderr, "Not a controller message, nlmsg_len=%d "
  78                                 "nlmsg_type=0x%x\n", answer->nlmsg_len, answer->nlmsg_type);
  79                         goto errout;
  80                 }
  81
  82                 if (ghdr->cmd != CTRL_CMD_NEWFAMILY) {
  83                         fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
  84                         goto errout;
  85                 }
  86
  87                 len -= NLMSG_LENGTH(GENL_HDRLEN);
  88
  89                 if (len < 0) {
  90                         fprintf(stderr, "wrong controller message len %d\n", len);
  91                         free(answer);
  92                         return -1;
  93                 }
  94
  95                 attrs = (struct rtattr *) ((char *) answer + NLMSG_LENGTH(GENL_HDRLEN));
  96                 parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
  97
  98                 if (tb[CTRL_ATTR_FAMILY_ID] == NULL) {
  99                         fprintf(stderr, "Missing family id TLV\n");
 100                         goto errout;
 101                 }
 102
 103                 ret = rta_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
 104         }
 105
 106 errout:
 107         free(answer);
 108         rtnl_close(&rth);
 109         return ret;
 110 }
 111
 112 static void print_ctrl_cmd_flags(FILE *fp, __u32 fl)
 113 {
 114         fprintf(fp, "\n\t\tCapabilities (0x%x):\n ", fl);
 115         if (!fl) {
 116                 fprintf(fp, "\n");
 117                 return;
 118         }
 119         fprintf(fp, "\t\t ");
 120
 121         if (fl & GENL_ADMIN_PERM)
 122                 fprintf(fp, " requires admin permission;");
 123         if (fl & GENL_CMD_CAP_DO)
 124                 fprintf(fp, " can doit;");
 125         if (fl & GENL_CMD_CAP_DUMP)
 126                 fprintf(fp, " can dumpit;");
 127         if (fl & GENL_CMD_CAP_HASPOL)
 128                 fprintf(fp, " has policy");
 129
 130         fprintf(fp, "\n");
 131 }
 132
 133 static int print_ctrl_cmds(FILE *fp, struct rtattr *arg, __u32 ctrl_ver)
 134 {
 135         struct rtattr *tb[CTRL_ATTR_OP_MAX + 1];
 136
 137         if (arg == NULL)
 138                 return -1;
 139
 140         parse_rtattr_nested(tb, CTRL_ATTR_OP_MAX, arg);
 141         if (tb[CTRL_ATTR_OP_ID]) {
 142                 __u32 *id = RTA_DATA(tb[CTRL_ATTR_OP_ID]);
 143                 fprintf(fp, " ID-0x%x ",*id);
 144         }
 145         /* we are only gonna do this for newer version of the controller */
 146         if (tb[CTRL_ATTR_OP_FLAGS] && ctrl_ver >= 0x2) {
 147                 __u32 *fl = RTA_DATA(tb[CTRL_ATTR_OP_FLAGS]);
 148                 print_ctrl_cmd_flags(fp, *fl);
 149         }
 150         return 0;
 151
 152 }
 153
 154 static int print_ctrl_grp(FILE *fp, struct rtattr *arg, __u32 ctrl_ver)
 155 {
 156         struct rtattr *tb[CTRL_ATTR_MCAST_GRP_MAX + 1];
 157
 158         if (arg == NULL)
 159                 return -1;
 160
 161         parse_rtattr_nested(tb, CTRL_ATTR_MCAST_GRP_MAX, arg);
 162         if (tb[2]) {
 163                 __u32 *id = RTA_DATA(tb[CTRL_ATTR_MCAST_GRP_ID]);
 164                 fprintf(fp, " ID-0x%x ",*id);
 165         }
 166         if (tb[1]) {
 167                 char *name = RTA_DATA(tb[CTRL_ATTR_MCAST_GRP_NAME]);
 168                 fprintf(fp, " name: %s ", name);
 169         }
 170         return 0;
 171
 172 }
 173
 174 /*
 175  * The controller sends one nlmsg per family
 176 */
 177 static int print_ctrl(struct rtnl_ctrl_data *ctrl,
 178                       struct nlmsghdr *n, void *arg)
 179 {
 180         struct rtattr *tb[CTRL_ATTR_MAX + 1];
 181         struct genlmsghdr *ghdr = NLMSG_DATA(n);
 182         int len = n->nlmsg_len;
 183         struct rtattr *attrs;
 184         FILE *fp = (FILE *) arg;
 185         __u32 ctrl_v = 0x1;
 186
 187         if (n->nlmsg_type !=  GENL_ID_CTRL) {
 188                 fprintf(stderr, "Not a controller message, nlmsg_len=%d "
 189                         "nlmsg_type=0x%x\n", n->nlmsg_len, n->nlmsg_type);
 190                 return 0;
 191         }
 192
 193         if (ghdr->cmd != CTRL_CMD_GETFAMILY &&
 194             ghdr->cmd != CTRL_CMD_DELFAMILY &&
 195             ghdr->cmd != CTRL_CMD_NEWFAMILY &&
 196             ghdr->cmd != CTRL_CMD_NEWMCAST_GRP &&
 197             ghdr->cmd != CTRL_CMD_DELMCAST_GRP) {
 198                 fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
 199                 return 0;
 200         }
 201
 202         len -= NLMSG_LENGTH(GENL_HDRLEN);
 203
 204         if (len < 0) {
 205                 fprintf(stderr, "wrong controller message len %d\n", len);
 206                 return -1;
 207         }
 208
 209         attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
 210         parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
 211
 212         if (tb[CTRL_ATTR_FAMILY_NAME]) {
 213                 char *name = RTA_DATA(tb[CTRL_ATTR_FAMILY_NAME]);
 214                 fprintf(fp, "\nName: %s\n",name);
 215         }
 216         if (tb[CTRL_ATTR_FAMILY_ID]) {
 217                 __u16 *id = RTA_DATA(tb[CTRL_ATTR_FAMILY_ID]);
 218                 fprintf(fp, "\tID: 0x%x ",*id);
 219         }
 220         if (tb[CTRL_ATTR_VERSION]) {
 221                 __u32 *v = RTA_DATA(tb[CTRL_ATTR_VERSION]);
 222                 fprintf(fp, " Version: 0x%x ",*v);
 223                 ctrl_v = *v;
 224         }
 225         if (tb[CTRL_ATTR_HDRSIZE]) {
 226                 __u32 *h = RTA_DATA(tb[CTRL_ATTR_HDRSIZE]);
 227                 fprintf(fp, " header size: %d ",*h);
 228         }
 229         if (tb[CTRL_ATTR_MAXATTR]) {
 230                 __u32 *ma = RTA_DATA(tb[CTRL_ATTR_MAXATTR]);
 231                 fprintf(fp, " max attribs: %d ",*ma);
 232         }
 233         /* end of family definitions .. */
 234         fprintf(fp,"\n");
 235         if (tb[CTRL_ATTR_OPS]) {
 236                 struct rtattr *tb2[GENL_MAX_FAM_OPS];
 237                 int i=0;
 238                 parse_rtattr_nested(tb2, GENL_MAX_FAM_OPS, tb[CTRL_ATTR_OPS]);
 239                 fprintf(fp, "\tcommands supported: \n");
 240                 for (i = 0; i < GENL_MAX_FAM_OPS; i++) {
 241                         if (tb2[i]) {
 242                                 fprintf(fp, "\t\t#%d: ", i);
 243                                 if (0 > print_ctrl_cmds(fp, tb2[i], ctrl_v)) {
 244                                         fprintf(fp, "Error printing command\n");
 245                                 }
 246                                 /* for next command */
 247                                 fprintf(fp,"\n");
 248                         }
 249                 }
 250
 251                 /* end of family::cmds definitions .. */
 252                 fprintf(fp,"\n");
 253         }
 254
 255         if (tb[CTRL_ATTR_MCAST_GROUPS]) {
 256                 struct rtattr *tb2[GENL_MAX_FAM_GRPS + 1];
 257                 int i;
 258
 259                 parse_rtattr_nested(tb2, GENL_MAX_FAM_GRPS,
 260                                     tb[CTRL_ATTR_MCAST_GROUPS]);
 261                 fprintf(fp, "\tmulticast groups:\n");
 262
 263                 for (i = 0; i < GENL_MAX_FAM_GRPS; i++) {
 264                         if (tb2[i]) {
 265                                 fprintf(fp, "\t\t#%d: ", i);
 266                                 if (0 > print_ctrl_grp(fp, tb2[i], ctrl_v))
 267                                         fprintf(fp, "Error printing group\n");
 268                                 /* for next group */
 269                                 fprintf(fp,"\n");
 270                         }
 271                 }
 272
 273                 /* end of family::groups definitions .. */
 274                 fprintf(fp,"\n");
 275         }
 276
 277         fflush(fp);
 278         return 0;
 279 }
 280
 281 static int print_ctrl2(struct nlmsghdr *n, void *arg)
 282 {
 283         return print_ctrl(NULL, n, arg);
 284 }
 285
 286 static int ctrl_list(int cmd, int argc, char **argv)
 287 {
 288         struct rtnl_handle rth;
 289         int ret = -1;
 290         char d[GENL_NAMSIZ];
 291         struct {
 292                 struct nlmsghdr         n;
 293                 struct genlmsghdr       g;
 294                 char                    buf[4096];
 295         } req = {
 296                 .n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),
 297                 .n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK,
 298                 .n.nlmsg_type = GENL_ID_CTRL,
 299                 .g.cmd = CTRL_CMD_GETFAMILY,
 300         };
 301         struct nlmsghdr *nlh = &req.n;
 302         struct nlmsghdr *answer = NULL;
 303
 304         if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
 305                 fprintf(stderr, "Cannot open generic netlink socket\n");
 306                 exit(1);
 307         }
 308
 309         if (cmd == CTRL_CMD_GETFAMILY) {
 310                 if (argc != 2) {
 311                         fprintf(stderr, "Wrong number of params\n");
 312                         return -1;
 313                 }
 314
 315                 if (matches(*argv, "name") == 0) {
 316                         NEXT_ARG();
 317                         strlcpy(d, *argv, sizeof(d));
 318                         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME,
 319                                   d, strlen(d) + 1);
 320                 } else if (matches(*argv, "id") == 0) {
 321                         __u16 id;
 322                         NEXT_ARG();
 323                         if (get_u16(&id, *argv, 0)) {
 324                                 fprintf(stderr, "Illegal \"id\"\n");
 325                                 goto ctrl_done;
 326                         }
 327
 328                         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_ID, &id, 2);
 329
 330                 } else {
 331                         fprintf(stderr, "Wrong params\n");
 332                         goto ctrl_done;
 333                 }
 334
 335                 if (rtnl_talk(&rth, nlh, &answer) < 0) {
 336                         fprintf(stderr, "Error talking to the kernel\n");
 337                         goto ctrl_done;
 338                 }
 339
 340                 if (print_ctrl2(answer, (void *) stdout) < 0) {
 341                         fprintf(stderr, "Dump terminated\n");
 342                         goto ctrl_done;
 343                 }
 344
 345         }
 346
 347         if (cmd == CTRL_CMD_UNSPEC) {
 348                 nlh->nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
 349                 nlh->nlmsg_seq = rth.dump = ++rth.seq;
 350
 351                 if (rtnl_send(&rth, nlh, nlh->nlmsg_len) < 0) {
 352                         perror("Failed to send dump request\n");
 353                         goto ctrl_done;
 354                 }
 355
 356                 rtnl_dump_filter(&rth, print_ctrl2, stdout);
 357
 358         }
 359
 360         ret = 0;
 361 ctrl_done:
 362         free(answer);
 363         rtnl_close(&rth);
 364         return ret;
 365 }
 366
 367 static int ctrl_listen(int argc, char **argv)
 368 {
 369         struct rtnl_handle rth;
 370
 371         if (rtnl_open_byproto(&rth, nl_mgrp(GENL_ID_CTRL), NETLINK_GENERIC) < 0) {
 372                 fprintf(stderr, "Canot open generic netlink socket\n");
 373                 return -1;
 374         }
 375
 376         if (rtnl_listen(&rth, print_ctrl, (void *) stdout) < 0)
 377                 return -1;
 378
 379         return 0;
 380 }
 381
 382 static int parse_ctrl(struct genl_util *a, int argc, char **argv)
 383 {
 384         argv++;
 385         if (--argc <= 0) {
 386                 fprintf(stderr, "wrong controller params\n");
 387                 return -1;
 388         }
 389
 390         if (matches(*argv, "monitor") == 0)
 391                 return ctrl_listen(argc-1, argv+1);
 392         if (matches(*argv, "get") == 0)
 393                 return ctrl_list(CTRL_CMD_GETFAMILY, argc-1, argv+1);
 394         if (matches(*argv, "list") == 0 ||
 395             matches(*argv, "show") == 0 ||
 396             matches(*argv, "lst") == 0)
 397                 return ctrl_list(CTRL_CMD_UNSPEC, argc-1, argv+1);
 398         if (matches(*argv, "help") == 0)
 399                 return usage();
 400
 401         fprintf(stderr, "ctrl command \"%s\" is unknown, try \"ctrl help\".\n",
 402                 *argv);
 403
 404         return -1;
 405 }
 406
 407 struct genl_util ctrl_genl_util = {
 408         .name = "ctrl",
 409         .parse_genlopt = parse_ctrl,
 410         .print_genlopt = print_ctrl2,
 411 };