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 #ifdef HAVE_LIBBSD
  22 #include <bsd/string.h>
  23 #endif
  24
  25 #include "utils.h"
  26 #include "genl_utils.h"
  27
  28 #define GENL_MAX_FAM_OPS        256
  29 #define GENL_MAX_FAM_GRPS       256
  30
  31 static int usage(void)
  32 {
  33         fprintf(stderr,"Usage: ctrl <CMD>\n" \
  34                        "CMD   := get <PARMS> | list | monitor\n" \
  35                        "PARMS := name <name> | id <id>\n" \
  36                        "Examples:\n" \
  37                        "\tctrl ls\n" \
  38                        "\tctrl monitor\n" \
  39                        "\tctrl get name foobar\n" \
  40                        "\tctrl get id 0xF\n");
  41         return -1;
  42 }
  43
  44 int genl_ctrl_resolve_family(const char *family)
  45 {
  46         struct rtnl_handle rth;
  47         int ret = 0;
  48         struct {
  49                 struct nlmsghdr         n;
  50                 struct genlmsghdr       g;
  51                 char                    buf[4096];
  52         } req = {
  53                 .n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),
  54                 .n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK,
  55                 .n.nlmsg_type = GENL_ID_CTRL,
  56                 .g.cmd = CTRL_CMD_GETFAMILY,
  57         };
  58         struct nlmsghdr *nlh = &req.n;
  59         struct genlmsghdr *ghdr = &req.g;
  60         struct nlmsghdr *answer = NULL;
  61
  62         if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
  63                 fprintf(stderr, "Cannot open generic netlink socket\n");
  64                 exit(1);
  65         }
  66
  67         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME, family, strlen(family) + 1);
  68
  69         if (rtnl_talk(&rth, nlh, &answer) < 0) {
  70                 fprintf(stderr, "Error talking to the kernel\n");
  71                 goto errout;
  72         }
  73
  74         {
  75                 struct rtattr *tb[CTRL_ATTR_MAX + 1];
  76                 int len = answer->nlmsg_len;
  77                 struct rtattr *attrs;
  78
  79                 if (answer->nlmsg_type !=  GENL_ID_CTRL) {
  80                         fprintf(stderr, "Not a controller message, nlmsg_len=%d "
  81                                 "nlmsg_type=0x%x\n", answer->nlmsg_len, answer->nlmsg_type);
  82                         goto errout;
  83                 }
  84
  85                 if (ghdr->cmd != CTRL_CMD_NEWFAMILY) {
  86                         fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
  87                         goto errout;
  88                 }
  89
  90                 len -= NLMSG_LENGTH(GENL_HDRLEN);
  91
  92                 if (len < 0) {
  93                         fprintf(stderr, "wrong controller message len %d\n", len);
  94                         free(answer);
  95                         return -1;
  96                 }
  97
  98                 attrs = (struct rtattr *) ((char *) answer + NLMSG_LENGTH(GENL_HDRLEN));
  99                 parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
 100
 101                 if (tb[CTRL_ATTR_FAMILY_ID] == NULL) {
 102                         fprintf(stderr, "Missing family id TLV\n");
 103                         goto errout;
 104                 }
 105
 106                 ret = rta_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
 107         }
 108
 109 errout:
 110         free(answer);
 111         rtnl_close(&rth);
 112         return ret;
 113 }
 114
 115 static void print_ctrl_cmd_flags(FILE *fp, __u32 fl)
 116 {
 117         fprintf(fp, "\n\t\tCapabilities (0x%x):\n ", fl);
 118         if (!fl) {
 119                 fprintf(fp, "\n");
 120                 return;
 121         }
 122         fprintf(fp, "\t\t ");
 123
 124         if (fl & GENL_ADMIN_PERM)
 125                 fprintf(fp, " requires admin permission;");
 126         if (fl & GENL_CMD_CAP_DO)
 127                 fprintf(fp, " can doit;");
 128         if (fl & GENL_CMD_CAP_DUMP)
 129                 fprintf(fp, " can dumpit;");
 130         if (fl & GENL_CMD_CAP_HASPOL)
 131                 fprintf(fp, " has policy");
 132
 133         fprintf(fp, "\n");
 134 }
 135
 136 static int print_ctrl_cmds(FILE *fp, struct rtattr *arg, __u32 ctrl_ver)
 137 {
 138         struct rtattr *tb[CTRL_ATTR_OP_MAX + 1];
 139
 140         if (arg == NULL)
 141                 return -1;
 142
 143         parse_rtattr_nested(tb, CTRL_ATTR_OP_MAX, arg);
 144         if (tb[CTRL_ATTR_OP_ID]) {
 145                 __u32 *id = RTA_DATA(tb[CTRL_ATTR_OP_ID]);
 146                 fprintf(fp, " ID-0x%x ",*id);
 147         }
 148         /* we are only gonna do this for newer version of the controller */
 149         if (tb[CTRL_ATTR_OP_FLAGS] && ctrl_ver >= 0x2) {
 150                 __u32 *fl = RTA_DATA(tb[CTRL_ATTR_OP_FLAGS]);
 151                 print_ctrl_cmd_flags(fp, *fl);
 152         }
 153         return 0;
 154
 155 }
 156
 157 static int print_ctrl_grp(FILE *fp, struct rtattr *arg, __u32 ctrl_ver)
 158 {
 159         struct rtattr *tb[CTRL_ATTR_MCAST_GRP_MAX + 1];
 160
 161         if (arg == NULL)
 162                 return -1;
 163
 164         parse_rtattr_nested(tb, CTRL_ATTR_MCAST_GRP_MAX, arg);
 165         if (tb[2]) {
 166                 __u32 *id = RTA_DATA(tb[CTRL_ATTR_MCAST_GRP_ID]);
 167                 fprintf(fp, " ID-0x%x ",*id);
 168         }
 169         if (tb[1]) {
 170                 char *name = RTA_DATA(tb[CTRL_ATTR_MCAST_GRP_NAME]);
 171                 fprintf(fp, " name: %s ", name);
 172         }
 173         return 0;
 174
 175 }
 176
 177 /*
 178  * The controller sends one nlmsg per family
 179 */
 180 static int print_ctrl(struct rtnl_ctrl_data *ctrl,
 181                       struct nlmsghdr *n, void *arg)
 182 {
 183         struct rtattr *tb[CTRL_ATTR_MAX + 1];
 184         struct genlmsghdr *ghdr = NLMSG_DATA(n);
 185         int len = n->nlmsg_len;
 186         struct rtattr *attrs;
 187         FILE *fp = (FILE *) arg;
 188         __u32 ctrl_v = 0x1;
 189
 190         if (n->nlmsg_type !=  GENL_ID_CTRL) {
 191                 fprintf(stderr, "Not a controller message, nlmsg_len=%d "
 192                         "nlmsg_type=0x%x\n", n->nlmsg_len, n->nlmsg_type);
 193                 return 0;
 194         }
 195
 196         if (ghdr->cmd != CTRL_CMD_GETFAMILY &&
 197             ghdr->cmd != CTRL_CMD_DELFAMILY &&
 198             ghdr->cmd != CTRL_CMD_NEWFAMILY &&
 199             ghdr->cmd != CTRL_CMD_NEWMCAST_GRP &&
 200             ghdr->cmd != CTRL_CMD_DELMCAST_GRP) {
 201                 fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
 202                 return 0;
 203         }
 204
 205         len -= NLMSG_LENGTH(GENL_HDRLEN);
 206
 207         if (len < 0) {
 208                 fprintf(stderr, "wrong controller message len %d\n", len);
 209                 return -1;
 210         }
 211
 212         attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
 213         parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
 214
 215         if (tb[CTRL_ATTR_FAMILY_NAME]) {
 216                 char *name = RTA_DATA(tb[CTRL_ATTR_FAMILY_NAME]);
 217                 fprintf(fp, "\nName: %s\n",name);
 218         }
 219         if (tb[CTRL_ATTR_FAMILY_ID]) {
 220                 __u16 *id = RTA_DATA(tb[CTRL_ATTR_FAMILY_ID]);
 221                 fprintf(fp, "\tID: 0x%x ",*id);
 222         }
 223         if (tb[CTRL_ATTR_VERSION]) {
 224                 __u32 *v = RTA_DATA(tb[CTRL_ATTR_VERSION]);
 225                 fprintf(fp, " Version: 0x%x ",*v);
 226                 ctrl_v = *v;
 227         }
 228         if (tb[CTRL_ATTR_HDRSIZE]) {
 229                 __u32 *h = RTA_DATA(tb[CTRL_ATTR_HDRSIZE]);
 230                 fprintf(fp, " header size: %d ",*h);
 231         }
 232         if (tb[CTRL_ATTR_MAXATTR]) {
 233                 __u32 *ma = RTA_DATA(tb[CTRL_ATTR_MAXATTR]);
 234                 fprintf(fp, " max attribs: %d ",*ma);
 235         }
 236         /* end of family definitions .. */
 237         fprintf(fp,"\n");
 238         if (tb[CTRL_ATTR_OPS]) {
 239                 struct rtattr *tb2[GENL_MAX_FAM_OPS];
 240                 int i=0;
 241                 parse_rtattr_nested(tb2, GENL_MAX_FAM_OPS, tb[CTRL_ATTR_OPS]);
 242                 fprintf(fp, "\tcommands supported: \n");
 243                 for (i = 0; i < GENL_MAX_FAM_OPS; i++) {
 244                         if (tb2[i]) {
 245                                 fprintf(fp, "\t\t#%d: ", i);
 246                                 if (0 > print_ctrl_cmds(fp, tb2[i], ctrl_v)) {
 247                                         fprintf(fp, "Error printing command\n");
 248                                 }
 249                                 /* for next command */
 250                                 fprintf(fp,"\n");
 251                         }
 252                 }
 253
 254                 /* end of family::cmds definitions .. */
 255                 fprintf(fp,"\n");
 256         }
 257
 258         if (tb[CTRL_ATTR_MCAST_GROUPS]) {
 259                 struct rtattr *tb2[GENL_MAX_FAM_GRPS + 1];
 260                 int i;
 261
 262                 parse_rtattr_nested(tb2, GENL_MAX_FAM_GRPS,
 263                                     tb[CTRL_ATTR_MCAST_GROUPS]);
 264                 fprintf(fp, "\tmulticast groups:\n");
 265
 266                 for (i = 0; i < GENL_MAX_FAM_GRPS; i++) {
 267                         if (tb2[i]) {
 268                                 fprintf(fp, "\t\t#%d: ", i);
 269                                 if (0 > print_ctrl_grp(fp, tb2[i], ctrl_v))
 270                                         fprintf(fp, "Error printing group\n");
 271                                 /* for next group */
 272                                 fprintf(fp,"\n");
 273                         }
 274                 }
 275
 276                 /* end of family::groups definitions .. */
 277                 fprintf(fp,"\n");
 278         }
 279
 280         fflush(fp);
 281         return 0;
 282 }
 283
 284 static int print_ctrl2(struct nlmsghdr *n, void *arg)
 285 {
 286         return print_ctrl(NULL, n, arg);
 287 }
 288
 289 static int ctrl_list(int cmd, int argc, char **argv)
 290 {
 291         struct rtnl_handle rth;
 292         int ret = -1;
 293         char d[GENL_NAMSIZ];
 294         struct {
 295                 struct nlmsghdr         n;
 296                 struct genlmsghdr       g;
 297                 char                    buf[4096];
 298         } req = {
 299                 .n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),
 300                 .n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK,
 301                 .n.nlmsg_type = GENL_ID_CTRL,
 302                 .g.cmd = CTRL_CMD_GETFAMILY,
 303         };
 304         struct nlmsghdr *nlh = &req.n;
 305         struct nlmsghdr *answer = NULL;
 306
 307         if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
 308                 fprintf(stderr, "Cannot open generic netlink socket\n");
 309                 exit(1);
 310         }
 311
 312         if (cmd == CTRL_CMD_GETFAMILY) {
 313                 if (argc != 2) {
 314                         fprintf(stderr, "Wrong number of params\n");
 315                         return -1;
 316                 }
 317
 318                 if (matches(*argv, "name") == 0) {
 319                         NEXT_ARG();
 320                         strlcpy(d, *argv, sizeof(d));
 321                         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME,
 322                                   d, strlen(d) + 1);
 323                 } else if (matches(*argv, "id") == 0) {
 324                         __u16 id;
 325                         NEXT_ARG();
 326                         if (get_u16(&id, *argv, 0)) {
 327                                 fprintf(stderr, "Illegal \"id\"\n");
 328                                 goto ctrl_done;
 329                         }
 330
 331                         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_ID, &id, 2);
 332
 333                 } else {
 334                         fprintf(stderr, "Wrong params\n");
 335                         goto ctrl_done;
 336                 }
 337
 338                 if (rtnl_talk(&rth, nlh, &answer) < 0) {
 339                         fprintf(stderr, "Error talking to the kernel\n");
 340                         goto ctrl_done;
 341                 }
 342
 343                 if (print_ctrl2(answer, (void *) stdout) < 0) {
 344                         fprintf(stderr, "Dump terminated\n");
 345                         goto ctrl_done;
 346                 }
 347
 348         }
 349
 350         if (cmd == CTRL_CMD_UNSPEC) {
 351                 nlh->nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
 352                 nlh->nlmsg_seq = rth.dump = ++rth.seq;
 353
 354                 if (rtnl_send(&rth, nlh, nlh->nlmsg_len) < 0) {
 355                         perror("Failed to send dump request\n");
 356                         goto ctrl_done;
 357                 }
 358
 359                 rtnl_dump_filter(&rth, print_ctrl2, stdout);
 360
 361         }
 362
 363         ret = 0;
 364 ctrl_done:
 365         free(answer);
 366         rtnl_close(&rth);
 367         return ret;
 368 }
 369
 370 static int ctrl_listen(int argc, char **argv)
 371 {
 372         struct rtnl_handle rth;
 373
 374         if (rtnl_open_byproto(&rth, nl_mgrp(GENL_ID_CTRL), NETLINK_GENERIC) < 0) {
 375                 fprintf(stderr, "Canot open generic netlink socket\n");
 376                 return -1;
 377         }
 378
 379         if (rtnl_listen(&rth, print_ctrl, (void *) stdout) < 0)
 380                 return -1;
 381
 382         return 0;
 383 }
 384
 385 static int parse_ctrl(struct genl_util *a, int argc, char **argv)
 386 {
 387         argv++;
 388         if (--argc <= 0) {
 389                 fprintf(stderr, "wrong controller params\n");
 390                 return -1;
 391         }
 392
 393         if (matches(*argv, "monitor") == 0)
 394                 return ctrl_listen(argc-1, argv+1);
 395         if (matches(*argv, "get") == 0)
 396                 return ctrl_list(CTRL_CMD_GETFAMILY, argc-1, argv+1);
 397         if (matches(*argv, "list") == 0 ||
 398             matches(*argv, "show") == 0 ||
 399             matches(*argv, "lst") == 0)
 400                 return ctrl_list(CTRL_CMD_UNSPEC, argc-1, argv+1);
 401         if (matches(*argv, "help") == 0)
 402                 return usage();
 403
 404         fprintf(stderr, "ctrl command \"%s\" is unknown, try \"ctrl help\".\n",
 405                 *argv);
 406
 407         return -1;
 408 }
 409
 410 struct genl_util ctrl_genl_util = {
 411         .name = "ctrl",
 412         .parse_genlopt = parse_ctrl,
 413         .print_genlopt = print_ctrl2,
 414 };