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;
  97                 int len;
  98                 int st;
  99
 100                 memset(&m, 0, sizeof(m));
 101                 sscanf(buf, "%d%s%d%d%s", &m.index, m.name, &m.users, &st,
 102                        hexa);
 103                 if (filter.dev && strcmp(filter.dev, m.name))
 104                         continue;
 105
 106                 m.addr.family = AF_PACKET;
 107
 108                 len = parse_hex(hexa, (unsigned char *)&m.addr.data, sizeof(m.addr.data));
 109                 if (len >= 0) {
 110                         struct ma_info *ma = malloc(sizeof(m));
 111
 112                         memcpy(ma, &m, sizeof(m));
 113                         ma->addr.bytelen = len;
 114                         ma->addr.bitlen = len<<3;
 115                         if (st)
 116                                 ma->features = "static";
 117                         maddr_ins(result_p, ma);
 118                 }
 119         }
 120         fclose(fp);
 121 }
 122
 123 static void read_igmp(struct ma_info **result_p)
 124 {
 125         struct ma_info m;
 126         char buf[256];
 127         FILE *fp = fopen("/proc/net/igmp", "r");
 128
 129         if (!fp)
 130                 return;
 131         memset(&m, 0, sizeof(m));
 132         if (!fgets(buf, sizeof(buf), fp)) {
 133                 fclose(fp);
 134                 return;
 135         }
 136
 137         m.addr.family = AF_INET;
 138         m.addr.bitlen = 32;
 139         m.addr.bytelen = 4;
 140
 141         while (fgets(buf, sizeof(buf), fp)) {
 142                 struct ma_info *ma;
 143
 144                 if (buf[0] != '\t') {
 145                         sscanf(buf, "%d%s", &m.index, m.name);
 146                         continue;
 147                 }
 148
 149                 if (filter.dev && strcmp(filter.dev, m.name))
 150                         continue;
 151
 152                 sscanf(buf, "%08x%d", (__u32 *)&m.addr.data, &m.users);
 153
 154                 ma = malloc(sizeof(m));
 155                 memcpy(ma, &m, sizeof(m));
 156                 maddr_ins(result_p, ma);
 157         }
 158         fclose(fp);
 159 }
 160
 161
 162 static void read_igmp6(struct ma_info **result_p)
 163 {
 164         char buf[256];
 165         FILE *fp = fopen("/proc/net/igmp6", "r");
 166
 167         if (!fp)
 168                 return;
 169
 170         while (fgets(buf, sizeof(buf), fp)) {
 171                 char hexa[256];
 172                 struct ma_info m;
 173                 int len;
 174
 175                 memset(&m, 0, sizeof(m));
 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                 m.addr.family = AF_INET6;
 182
 183                 len = parse_hex(hexa, (unsigned char *)&m.addr.data, sizeof(m.addr.data));
 184                 if (len >= 0) {
 185                         struct ma_info *ma = malloc(sizeof(m));
 186
 187                         memcpy(ma, &m, sizeof(m));
 188
 189                         ma->addr.bytelen = len;
 190                         ma->addr.bitlen = len<<3;
 191                         maddr_ins(result_p, ma);
 192                 }
 193         }
 194         fclose(fp);
 195 }
 196
 197 static void print_maddr(FILE *fp, struct ma_info *list)
 198 {
 199         fprintf(fp, "\t");
 200
 201         if (list->addr.family == AF_PACKET) {
 202                 SPRINT_BUF(b1);
 203                 fprintf(fp, "link  %s", ll_addr_n2a((unsigned char *)list->addr.data,
 204                                                     list->addr.bytelen, 0,
 205                                                     b1, sizeof(b1)));
 206         } else {
 207                 switch (list->addr.family) {
 208                 case AF_INET:
 209                         fprintf(fp, "inet  ");
 210                         break;
 211                 case AF_INET6:
 212                         fprintf(fp, "inet6 ");
 213                         break;
 214                 default:
 215                         fprintf(fp, "family %d ", list->addr.family);
 216                         break;
 217                 }
 218                 fprintf(fp, "%s",
 219                         format_host(list->addr.family,
 220                                     -1, list->addr.data));
 221         }
 222         if (list->users != 1)
 223                 fprintf(fp, " users %d", list->users);
 224         if (list->features)
 225                 fprintf(fp, " %s", list->features);
 226         fprintf(fp, "\n");
 227 }
 228
 229 static void print_mlist(FILE *fp, struct ma_info *list)
 230 {
 231         int cur_index = 0;
 232
 233         for (; list; list = list->next) {
 234                 if (oneline) {
 235                         cur_index = list->index;
 236                         fprintf(fp, "%d:\t%s%s", cur_index, list->name, _SL_);
 237                 } else if (cur_index != list->index) {
 238                         cur_index = list->index;
 239                         fprintf(fp, "%d:\t%s\n", cur_index, list->name);
 240                 }
 241                 print_maddr(fp, list);
 242         }
 243 }
 244
 245 static int multiaddr_list(int argc, char **argv)
 246 {
 247         struct ma_info *list = NULL;
 248
 249         if (!filter.family)
 250                 filter.family = preferred_family;
 251
 252         while (argc > 0) {
 253                 if (1) {
 254                         if (strcmp(*argv, "dev") == 0) {
 255                                 NEXT_ARG();
 256                         } else if (matches(*argv, "help") == 0)
 257                                 usage();
 258                         if (filter.dev)
 259                                 duparg2("dev", *argv);
 260                         filter.dev = *argv;
 261                 }
 262                 argv++; argc--;
 263         }
 264
 265         if (!filter.family || filter.family == AF_PACKET)
 266                 read_dev_mcast(&list);
 267         if (!filter.family || filter.family == AF_INET)
 268                 read_igmp(&list);
 269         if (!filter.family || filter.family == AF_INET6)
 270                 read_igmp6(&list);
 271         print_mlist(stdout, list);
 272         return 0;
 273 }
 274
 275 static int multiaddr_modify(int cmd, int argc, char **argv)
 276 {
 277         struct ifreq ifr;
 278         int fd;
 279
 280         memset(&ifr, 0, sizeof(ifr));
 281
 282         if (cmd == RTM_NEWADDR)
 283                 cmd = SIOCADDMULTI;
 284         else
 285                 cmd = SIOCDELMULTI;
 286
 287         while (argc > 0) {
 288                 if (strcmp(*argv, "dev") == 0) {
 289                         NEXT_ARG();
 290                         if (ifr.ifr_name[0])
 291                                 duparg("dev", *argv);
 292                         strncpy(ifr.ifr_name, *argv, IFNAMSIZ);
 293                 } else {
 294                         if (matches(*argv, "address") == 0) {
 295                                 NEXT_ARG();
 296                         }
 297                         if (matches(*argv, "help") == 0)
 298                                 usage();
 299                         if (ifr.ifr_hwaddr.sa_data[0])
 300                                 duparg("address", *argv);
 301                         if (ll_addr_a2n(ifr.ifr_hwaddr.sa_data,
 302                                         14, *argv) < 0) {
 303                                 fprintf(stderr, "Error: \"%s\" is not a legal ll address.\n", *argv);
 304                                 exit(1);
 305                         }
 306                 }
 307                 argc--; argv++;
 308         }
 309         if (ifr.ifr_name[0] == 0) {
 310                 fprintf(stderr, "Not enough information: \"dev\" is required.\n");
 311                 exit(-1);
 312         }
 313
 314         fd = socket(AF_INET, SOCK_DGRAM, 0);
 315         if (fd < 0) {
 316                 perror("Cannot create socket");
 317                 exit(1);
 318         }
 319         if (ioctl(fd, cmd, (char *)&ifr) != 0) {
 320                 perror("ioctl");
 321                 exit(1);
 322         }
 323         close(fd);
 324
 325         exit(0);
 326 }
 327
 328
 329 int do_multiaddr(int argc, char **argv)
 330 {
 331         if (argc < 1)
 332                 return multiaddr_list(0, NULL);
 333         if (matches(*argv, "add") == 0)
 334                 return multiaddr_modify(RTM_NEWADDR, argc-1, argv+1);
 335         if (matches(*argv, "delete") == 0)
 336                 return multiaddr_modify(RTM_DELADDR, argc-1, argv+1);
 337         if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
 338             || matches(*argv, "lst") == 0)
 339                 return multiaddr_list(argc-1, argv+1);
 340         if (matches(*argv, "help") == 0)
 341                 usage();
 342         fprintf(stderr, "Command \"%s\" is unknown, try \"ip maddr help\".\n", *argv);
 343         exit(-1);
 344 }