ip/ipmaddr.c

   1 /*
   2  * ipmaddr.c            "ip maddress".
   3  *
   4  *              This program is free software; you can redistribute 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:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  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/ioctl.h>
  19 #include <sys/socket.h>
  20 #include <netinet/in.h>
  21 #include <arpa/inet.h>
  22 #include <string.h>
  23
  24 #include <linux/netdevice.h>
  25 #include <linux/if.h>
  26 #include <linux/if_arp.h>
  27 #include <linux/sockios.h>
  28
  29 #include "rt_names.h"
  30 #include "utils.h"
  31 #include "ip_common.h"
  32
  33 static struct {
  34         char *dev;
  35         int  family;
  36 } filter;
  37
  38 static void usage(void) __attribute__((noreturn));
  39
  40 static void usage(void)
  41 {
  42         fprintf(stderr, "Usage: ip maddr [ add | del ] MULTIADDR dev STRING\n");
  43         fprintf(stderr, "       ip maddr show [ dev STRING ]\n");
  44         exit(-1);
  45 }
  46
  47 static int parse_hex(char *str, unsigned char *addr, size_t size)
  48 {
  49         int len = 0;
  50
  51         while (*str && (len < 2 * size)) {
  52                 int tmp;
  53
  54                 if (str[1] == 0)
  55                         return -1;
  56                 if (sscanf(str, "%02x", &tmp) != 1)
  57                         return -1;
  58                 addr[len] = tmp;
  59                 len++;
  60                 str += 2;
  61         }
  62         return len;
  63 }
  64
  65 struct ma_info {
  66         struct ma_info *next;
  67         int             index;
  68         int             users;
  69         char            *features;
  70         char            name[IFNAMSIZ];
  71         inet_prefix     addr;
  72 };
  73
  74 static void maddr_ins(struct ma_info **lst, struct ma_info *m)
  75 {
  76         struct ma_info *mp;
  77
  78         for (; (mp = *lst) != NULL; lst = &mp->next) {
  79                 if (mp->index > m->index)
  80                         break;
  81         }
  82         m->next = *lst;
  83         *lst = m;
  84 }
  85
  86 static void read_dev_mcast(struct ma_info **result_p)
  87 {
  88         char buf[256];
  89         FILE *fp = fopen("/proc/net/dev_mcast", "r");
  90
  91         if (!fp)
  92                 return;
  93
  94         while (fgets(buf, sizeof(buf), fp)) {
  95                 char hexa[256];
  96                 struct ma_info m = { .addr.family = AF_PACKET };
  97                 int len;
  98                 int st;
  99
 100                 sscanf(buf, "%d%s%d%d%s", &m.index, m.name, &m.users, &st,
 101                        hexa);
 102                 if (filter.dev && strcmp(filter.dev, m.name))
 103                         continue;
 104
 105                 len = parse_hex(hexa, (unsigned char *)&m.addr.data, sizeof(m.addr.data));
 106                 if (len >= 0) {
 107                         struct ma_info *ma = malloc(sizeof(m));
 108
 109                         memcpy(ma, &m, sizeof(m));
 110                         ma->addr.bytelen = len;
 111                         ma->addr.bitlen = len<<3;
 112                         if (st)
 113                                 ma->features = "static";
 114                         maddr_ins(result_p, ma);
 115                 }
 116         }
 117         fclose(fp);
 118 }
 119
 120 static void read_igmp(struct ma_info **result_p)
 121 {
 122         struct ma_info m = {
 123                 .addr.family = AF_INET,
 124                 .addr.bitlen = 32,
 125                 .addr.bytelen = 4,
 126         };
 127         char buf[256];
 128         FILE *fp = fopen("/proc/net/igmp", "r");
 129
 130         if (!fp)
 131                 return;
 132         if (!fgets(buf, sizeof(buf), fp)) {
 133                 fclose(fp);
 134                 return;
 135         }
 136
 137         while (fgets(buf, sizeof(buf), fp)) {
 138                 struct ma_info *ma;
 139
 140                 if (buf[0] != '\t') {
 141                         size_t len;
 142
 143                         sscanf(buf, "%d%s", &m.index, m.name);
 144                         len = strlen(m.name);
 145                         if (m.name[len - 1] == ':')
 146                                 m.name[len - 1] = '\0';
 147                         continue;
 148                 }
 149
 150                 if (filter.dev && strcmp(filter.dev, m.name))
 151                         continue;
 152
 153                 sscanf(buf, "%08x%d", (__u32 *)&m.addr.data, &m.users);
 154
 155                 ma = malloc(sizeof(m));
 156                 memcpy(ma, &m, sizeof(m));
 157                 maddr_ins(result_p, ma);
 158         }
 159         fclose(fp);
 160 }
 161
 162
 163 static void read_igmp6(struct ma_info **result_p)
 164 {
 165         char buf[256];
 166         FILE *fp = fopen("/proc/net/igmp6", "r");
 167
 168         if (!fp)
 169                 return;
 170
 171         while (fgets(buf, sizeof(buf), fp)) {
 172                 char hexa[256];
 173                 struct ma_info m = { .addr.family = AF_INET6 };
 174                 int len;
 175
 176                 sscanf(buf, "%d%s%s%d", &m.index, m.name, hexa, &m.users);
 177
 178                 if (filter.dev && strcmp(filter.dev, m.name))
 179                         continue;
 180
 181                 len = parse_hex(hexa, (unsigned char *)&m.addr.data, sizeof(m.addr.data));
 182                 if (len >= 0) {
 183                         struct ma_info *ma = malloc(sizeof(m));
 184
 185                         memcpy(ma, &m, sizeof(m));
 186
 187                         ma->addr.bytelen = len;
 188                         ma->addr.bitlen = len<<3;
 189                         maddr_ins(result_p, ma);
 190                 }
 191         }
 192         fclose(fp);
 193 }
 194
 195 static void print_maddr(FILE *fp, struct ma_info *list)
 196 {
 197         fprintf(fp, "\t");
 198
 199         if (list->addr.family == AF_PACKET) {
 200                 SPRINT_BUF(b1);
 201                 fprintf(fp, "link  %s", ll_addr_n2a((unsigned char *)list->addr.data,
 202                                                     list->addr.bytelen, 0,
 203                                                     b1, sizeof(b1)));
 204         } else {
 205                 switch (list->addr.family) {
 206                 case AF_INET:
 207                         fprintf(fp, "inet  ");
 208                         break;
 209                 case AF_INET6:
 210                         fprintf(fp, "inet6 ");
 211                         break;
 212                 default:
 213                         fprintf(fp, "family %d ", list->addr.family);
 214                         break;
 215                 }
 216                 fprintf(fp, "%s",
 217                         format_host(list->addr.family,
 218                                     -1, list->addr.data));
 219         }
 220         if (list->users != 1)
 221                 fprintf(fp, " users %d", list->users);
 222         if (list->features)
 223                 fprintf(fp, " %s", list->features);
 224         fprintf(fp, "\n");
 225 }
 226
 227 static void print_mlist(FILE *fp, struct ma_info *list)
 228 {
 229         int cur_index = 0;
 230
 231         for (; list; list = list->next) {
 232                 if (oneline) {
 233                         cur_index = list->index;
 234                         fprintf(fp, "%d:\t%s%s", cur_index, list->name, _SL_);
 235                 } else if (cur_index != list->index) {
 236                         cur_index = list->index;
 237                         fprintf(fp, "%d:\t%s\n", cur_index, list->name);
 238                 }
 239                 print_maddr(fp, list);
 240         }
 241 }
 242
 243 static int multiaddr_list(int argc, char **argv)
 244 {
 245         struct ma_info *list = NULL;
 246
 247         if (!filter.family)
 248                 filter.family = preferred_family;
 249
 250         while (argc > 0) {
 251                 if (1) {
 252                         if (strcmp(*argv, "dev") == 0) {
 253                                 NEXT_ARG();
 254                         } else if (matches(*argv, "help") == 0)
 255                                 usage();
 256                         if (filter.dev)
 257                                 duparg2("dev", *argv);
 258                         filter.dev = *argv;
 259                 }
 260                 argv++; argc--;
 261         }
 262
 263         if (!filter.family || filter.family == AF_PACKET)
 264                 read_dev_mcast(&list);
 265         if (!filter.family || filter.family == AF_INET)
 266                 read_igmp(&list);
 267         if (!filter.family || filter.family == AF_INET6)
 268                 read_igmp6(&list);
 269         print_mlist(stdout, list);
 270         return 0;
 271 }
 272
 273 static int multiaddr_modify(int cmd, int argc, char **argv)
 274 {
 275         struct ifreq ifr = {};
 276         int fd;
 277
 278         if (cmd == RTM_NEWADDR)
 279                 cmd = SIOCADDMULTI;
 280         else
 281                 cmd = SIOCDELMULTI;
 282
 283         while (argc > 0) {
 284                 if (strcmp(*argv, "dev") == 0) {
 285                         NEXT_ARG();
 286                         if (ifr.ifr_name[0])
 287                                 duparg("dev", *argv);
 288                         if (get_ifname(ifr.ifr_name, *argv))
 289                                 invarg("\"dev\" not a valid ifname", *argv);
 290                 } else {
 291                         if (matches(*argv, "address") == 0) {
 292                                 NEXT_ARG();
 293                         }
 294                         if (matches(*argv, "help") == 0)
 295                                 usage();
 296                         if (ifr.ifr_hwaddr.sa_data[0])
 297                                 duparg("address", *argv);
 298                         if (ll_addr_a2n(ifr.ifr_hwaddr.sa_data,
 299                                         14, *argv) < 0) {
 300                                 fprintf(stderr, "Error: \"%s\" is not a legal ll address.\n", *argv);
 301                                 exit(1);
 302                         }
 303                 }
 304                 argc--; argv++;
 305         }
 306         if (ifr.ifr_name[0] == 0) {
 307                 fprintf(stderr, "Not enough information: \"dev\" is required.\n");
 308                 exit(-1);
 309         }
 310
 311         fd = socket(AF_INET, SOCK_DGRAM, 0);
 312         if (fd < 0) {
 313                 perror("Cannot create socket");
 314                 exit(1);
 315         }
 316         if (ioctl(fd, cmd, (char *)&ifr) != 0) {
 317                 perror("ioctl");
 318                 exit(1);
 319         }
 320         close(fd);
 321
 322         exit(0);
 323 }
 324
 325
 326 int do_multiaddr(int argc, char **argv)
 327 {
 328         if (argc < 1)
 329                 return multiaddr_list(0, NULL);
 330         if (matches(*argv, "add") == 0)
 331                 return multiaddr_modify(RTM_NEWADDR, argc-1, argv+1);
 332         if (matches(*argv, "delete") == 0)
 333                 return multiaddr_modify(RTM_DELADDR, argc-1, argv+1);
 334         if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
 335             || matches(*argv, "lst") == 0)
 336                 return multiaddr_list(argc-1, argv+1);
 337         if (matches(*argv, "help") == 0)
 338                 usage();
 339         fprintf(stderr, "Command \"%s\" is unknown, try \"ip maddr help\".\n", *argv);
 340         exit(-1);
 341 }