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         struct nlmsghdr *nlh;
  46         struct genlmsghdr *ghdr;
  47         int ret = 0;
  48         struct {
  49                 struct nlmsghdr         n;
  50                 char                    buf[4096];
  51         } req;
  52
  53         memset(&req, 0, sizeof(req));
  54
  55         nlh = &req.n;
  56         nlh->nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
  57         nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
  58         nlh->nlmsg_type = GENL_ID_CTRL;
  59
  60         ghdr = NLMSG_DATA(&req.n);
  61         ghdr->cmd = CTRL_CMD_GETFAMILY;
  62
  63         if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
  64                 fprintf(stderr, "Cannot open generic netlink socket\n");
  65                 exit(1);
  66         }
  67
  68         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME, family, strlen(family) + 1);
  69
  70         if (rtnl_talk(&rth, nlh, 0, 0, nlh, NULL, NULL) < 0) {
  71                 fprintf(stderr, "Error talking to the kernel\n");
  72                 goto errout;
  73         }
  74
  75         {
  76                 struct rtattr *tb[CTRL_ATTR_MAX + 1];
  77                 struct genlmsghdr *ghdr = NLMSG_DATA(nlh);
  78                 int len = nlh->nlmsg_len;
  79                 struct rtattr *attrs;
  80
  81                 if (nlh->nlmsg_type !=  GENL_ID_CTRL) {
  82                         fprintf(stderr, "Not a controller message, nlmsg_len=%d "
  83                                 "nlmsg_type=0x%x\n", nlh->nlmsg_len, nlh->nlmsg_type);
  84                         goto errout;
  85                 }
  86
  87                 if (ghdr->cmd != CTRL_CMD_NEWFAMILY) {
  88                         fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
  89                         goto errout;
  90                 }
  91
  92                 len -= NLMSG_LENGTH(GENL_HDRLEN);
  93
  94                 if (len < 0) {
  95                         fprintf(stderr, "wrong controller message len %d\n", len);
  96                         return -1;
  97                 }
  98
  99                 attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
 100                 parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
 101
 102                 if (tb[CTRL_ATTR_FAMILY_ID] == NULL) {
 103                         fprintf(stderr, "Missing family id TLV\n");
 104                         goto errout;
 105                 }
 106
 107                 ret = *(__u16 *) RTA_DATA(tb[CTRL_ATTR_FAMILY_ID]);
 108         }
 109
 110 errout:
 111         rtnl_close(&rth);
 112         return ret;
 113 }
 114
 115 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(const struct sockaddr_nl *who, struct nlmsghdr *n,
 181                       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 ctrl_list(int cmd, int argc, char **argv)
 285 {
 286         struct rtnl_handle rth;
 287         struct nlmsghdr *nlh;
 288         struct genlmsghdr *ghdr;
 289         int ret = -1;
 290         char d[GENL_NAMSIZ];
 291         struct {
 292                 struct nlmsghdr         n;
 293                 char                    buf[4096];
 294         } req;
 295
 296         memset(&req, 0, sizeof(req));
 297
 298         nlh = &req.n;
 299         nlh->nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
 300         nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
 301         nlh->nlmsg_type = GENL_ID_CTRL;
 302
 303         ghdr = NLMSG_DATA(&req.n);
 304         ghdr->cmd = CTRL_CMD_GETFAMILY;
 305
 306         if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
 307                 fprintf(stderr, "Cannot open generic netlink socket\n");
 308                 exit(1);
 309         }
 310
 311         if (cmd == CTRL_CMD_GETFAMILY) {
 312                 if (argc != 2) {
 313                         fprintf(stderr, "Wrong number of params\n");
 314                         return -1;
 315                 }
 316
 317                 if (matches(*argv, "name") == 0) {
 318                         NEXT_ARG();
 319                         strncpy(d, *argv, sizeof (d) - 1);
 320                         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME,
 321                                   d, strlen(d) + 1);
 322                 } else if (matches(*argv, "id") == 0) {
 323                         __u16 id;
 324                         NEXT_ARG();
 325                         if (get_u16(&id, *argv, 0)) {
 326                                 fprintf(stderr, "Illegal \"id\"\n");
 327                                 goto ctrl_done;
 328                         }
 329
 330                         addattr_l(nlh, 128, CTRL_ATTR_FAMILY_ID, &id, 2);
 331
 332                 } else {
 333                         fprintf(stderr, "Wrong params\n");
 334                         goto ctrl_done;
 335                 }
 336
 337                 if (rtnl_talk(&rth, nlh, 0, 0, nlh, NULL, NULL) < 0) {
 338                         fprintf(stderr, "Error talking to the kernel\n");
 339                         goto ctrl_done;
 340                 }
 341
 342                 if (print_ctrl(NULL, nlh, (void *) stdout) < 0) {
 343                         fprintf(stderr, "Dump terminated\n");
 344                         goto ctrl_done;
 345                 }
 346
 347         }
 348
 349         if (cmd == CTRL_CMD_UNSPEC) {
 350                 nlh->nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
 351                 nlh->nlmsg_seq = rth.dump = ++rth.seq;
 352
 353                 if (rtnl_send(&rth, (const char *) nlh, nlh->nlmsg_len) < 0) {
 354                         perror("Failed to send dump request\n");
 355                         goto ctrl_done;
 356                 }
 357
 358                 rtnl_dump_filter(&rth, print_ctrl, stdout, NULL, NULL);
 359
 360         }
 361
 362         ret = 0;
 363 ctrl_done:
 364         rtnl_close(&rth);
 365         return ret;
 366 }
 367
 368 static int ctrl_listen(int argc, char **argv)
 369 {
 370         struct rtnl_handle rth;
 371
 372         if (rtnl_open_byproto(&rth, nl_mgrp(GENL_ID_CTRL), NETLINK_GENERIC) < 0) {
 373                 fprintf(stderr, "Canot open generic netlink socket\n");
 374                 return -1;
 375         }
 376
 377         if (rtnl_listen(&rth, print_ctrl, (void *) stdout) < 0)
 378                 return -1;
 379
 380         return 0;
 381 }
 382
 383 static int parse_ctrl(struct genl_util *a, int argc, char **argv)
 384 {
 385         argv++;
 386         if (--argc <= 0) {
 387                 fprintf(stderr, "wrong controller params\n");
 388                 return -1;
 389         }
 390
 391         if (matches(*argv, "monitor") == 0)
 392                 return ctrl_listen(argc-1, argv+1);
 393         if (matches(*argv, "get") == 0)
 394                 return ctrl_list(CTRL_CMD_GETFAMILY, argc-1, argv+1);
 395         if (matches(*argv, "list") == 0 ||
 396             matches(*argv, "show") == 0 ||
 397             matches(*argv, "lst") == 0)
 398                 return ctrl_list(CTRL_CMD_UNSPEC, argc-1, argv+1);
 399         if (matches(*argv, "help") == 0)
 400                 return usage();
 401
 402         fprintf(stderr, "ctrl command \"%s\" is unknown, try \"ctrl -help\".\n",
 403                 *argv);
 404
 405         return -1;
 406 }
 407
 408 struct genl_util ctrl_genl_util = {
 409         .name = "ctrl",
 410         .parse_genlopt = parse_ctrl,
 411         .print_genlopt = print_ctrl,
 412 };