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