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                 if (str[1] == 0)
  54                         return -1;
  55                 if (sscanf(str, "%02x", &tmp) != 1)
  56                         return -1;
  57                 addr[len] = tmp;
  58                 len++;
  59                 str += 2;
  60         }
  61         return len;
  62 }
  63
  64 struct ma_info
  65 {
  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                 char abuf[256];
 208                 switch(list->addr.family) {
 209                 case AF_INET:
 210                         fprintf(fp, "inet  ");
 211                         break;
 212                 case AF_INET6:
 213                         fprintf(fp, "inet6 ");
 214                         break;
 215                 default:
 216                         fprintf(fp, "family %d ", list->addr.family);
 217                         break;
 218                 }
 219                 fprintf(fp, "%s",
 220                         format_host(list->addr.family,
 221                                     -1,
 222                                     list->addr.data,
 223                                     abuf, sizeof(abuf)));
 224         }
 225         if (list->users != 1)
 226                 fprintf(fp, " users %d", list->users);
 227         if (list->features)
 228                 fprintf(fp, " %s", list->features);
 229         fprintf(fp, "\n");
 230 }
 231
 232 static void print_mlist(FILE *fp, struct ma_info *list)
 233 {
 234         int cur_index = 0;
 235
 236         for (; list; list = list->next) {
 237                 if (oneline) {
 238                         cur_index = list->index;
 239                         fprintf(fp, "%d:\t%s%s", cur_index, list->name, _SL_);
 240                 } else if (cur_index != list->index) {
 241                         cur_index = list->index;
 242                         fprintf(fp, "%d:\t%s\n", cur_index, list->name);
 243                 }
 244                 print_maddr(fp, list);
 245         }
 246 }
 247
 248 static int multiaddr_list(int argc, char **argv)
 249 {
 250         struct ma_info *list = NULL;
 251
 252         if (!filter.family)
 253                 filter.family = preferred_family;
 254
 255         while (argc > 0) {
 256                 if (1) {
 257                         if (strcmp(*argv, "dev") == 0) {
 258                                 NEXT_ARG();
 259                         }
 260                         else if (matches(*argv, "help") == 0)
 261                                 usage();
 262                         if (filter.dev)
 263                                 duparg2("dev", *argv);
 264                         filter.dev = *argv;
 265                 }
 266                 argv++; argc--;
 267         }
 268
 269         if (!filter.family || filter.family == AF_PACKET)
 270                 read_dev_mcast(&list);
 271         if (!filter.family || filter.family == AF_INET)
 272                 read_igmp(&list);
 273         if (!filter.family || filter.family == AF_INET6)
 274                 read_igmp6(&list);
 275         print_mlist(stdout, list);
 276         return 0;
 277 }
 278
 279 static int multiaddr_modify(int cmd, int argc, char **argv)
 280 {
 281         struct ifreq ifr;
 282         int fd;
 283
 284         memset(&ifr, 0, sizeof(ifr));
 285
 286         if (cmd == RTM_NEWADDR)
 287                 cmd = SIOCADDMULTI;
 288         else
 289                 cmd = SIOCDELMULTI;
 290
 291         while (argc > 0) {
 292                 if (strcmp(*argv, "dev") == 0) {
 293                         NEXT_ARG();
 294                         if (ifr.ifr_name[0])
 295                                 duparg("dev", *argv);
 296                         strncpy(ifr.ifr_name, *argv, IFNAMSIZ);
 297                 } else {
 298                         if (matches(*argv, "address") == 0) {
 299                                 NEXT_ARG();
 300                         }
 301                         if (matches(*argv, "help") == 0)
 302                                 usage();
 303                         if (ifr.ifr_hwaddr.sa_data[0])
 304                                 duparg("address", *argv);
 305                         if (ll_addr_a2n(ifr.ifr_hwaddr.sa_data,
 306                                         14, *argv) < 0) {
 307                                 fprintf(stderr, "Error: \"%s\" is not a legal ll address.\n", *argv);
 308                                 exit(1);
 309                         }
 310                 }
 311                 argc--; argv++;
 312         }
 313         if (ifr.ifr_name[0] == 0) {
 314                 fprintf(stderr, "Not enough information: \"dev\" is required.\n");
 315                 exit(-1);
 316         }
 317
 318         fd = socket(AF_INET, SOCK_DGRAM, 0);
 319         if (fd < 0) {
 320                 perror("Cannot create socket");
 321                 exit(1);
 322         }
 323         if (ioctl(fd, cmd, (char*)&ifr) != 0) {
 324                 perror("ioctl");
 325                 exit(1);
 326         }
 327         close(fd);
 328
 329         exit(0);
 330 }
 331
 332
 333 int do_multiaddr(int argc, char **argv)
 334 {
 335         if (argc < 1)
 336                 return multiaddr_list(0, NULL);
 337         if (matches(*argv, "add") == 0)
 338                 return multiaddr_modify(RTM_NEWADDR, argc-1, argv+1);
 339         if (matches(*argv, "delete") == 0)
 340                 return multiaddr_modify(RTM_DELADDR, argc-1, argv+1);
 341         if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
 342             || matches(*argv, "lst") == 0)
 343                 return multiaddr_list(argc-1, argv+1);
 344         if (matches(*argv, "help") == 0)
 345                 usage();
 346         fprintf(stderr, "Command \"%s\" is unknown, try \"ip maddr help\".\n", *argv);
 347         exit(-1);
 348 }