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
  32 static struct {
  33         char *dev;
  34         int  family;
  35 } filter;
  36
  37 static void usage(void) __attribute__((noreturn));
  38
  39 static void usage(void)
  40 {
  41         fprintf(stderr, "Usage: ip maddr [ add | del ] MULTIADDR dev STRING\n");
  42         fprintf(stderr, "       ip maddr show [ dev STRING ]\n");
  43         exit(-1);
  44 }
  45
  46 static int parse_hex(char *str, unsigned char *addr, size_t size)
  47 {
  48         int len=0;
  49
  50         while (*str && (len < 2 * size)) {
  51                 int tmp;
  52                 if (str[1] == 0)
  53                         return -1;
  54                 if (sscanf(str, "%02x", &tmp) != 1)
  55                         return -1;
  56                 addr[len] = tmp;
  57                 len++;
  58                 str += 2;
  59         }
  60         return len;
  61 }
  62
  63 struct ma_info
  64 {
  65         struct ma_info *next;
  66         int             index;
  67         int             users;
  68         char            *features;
  69         char            name[IFNAMSIZ];
  70         inet_prefix     addr;
  71 };
  72
  73 void maddr_ins(struct ma_info **lst, struct ma_info *m)
  74 {
  75         struct ma_info *mp;
  76
  77         for (; (mp=*lst) != NULL; lst = &mp->next) {
  78                 if (mp->index > m->index)
  79                         break;
  80         }
  81         m->next = *lst;
  82         *lst = m;
  83 }
  84
  85 void read_dev_mcast(struct ma_info **result_p)
  86 {
  87         char buf[256];
  88         FILE *fp = fopen("/proc/net/dev_mcast", "r");
  89
  90         if (!fp)
  91                 return;
  92
  93         while (fgets(buf, sizeof(buf), fp)) {
  94                 char hexa[256];
  95                 struct ma_info m;
  96                 int len;
  97                 int st;
  98
  99                 memset(&m, 0, sizeof(m));
 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                 m.addr.family = AF_PACKET;
 106
 107                 len = parse_hex(hexa, (unsigned char*)&m.addr.data, sizeof (m.addr.data));
 108                 if (len >= 0) {
 109                         struct ma_info *ma = malloc(sizeof(m));
 110
 111                         memcpy(ma, &m, sizeof(m));
 112                         ma->addr.bytelen = len;
 113                         ma->addr.bitlen = len<<3;
 114                         if (st)
 115                                 ma->features = "static";
 116                         maddr_ins(result_p, ma);
 117                 }
 118         }
 119         fclose(fp);
 120 }
 121
 122 void read_igmp(struct ma_info **result_p)
 123 {
 124         struct ma_info m;
 125         char buf[256];
 126         FILE *fp = fopen("/proc/net/igmp", "r");
 127
 128         if (!fp)
 129                 return;
 130         memset(&m, 0, sizeof(m));
 131         if (!fgets(buf, sizeof(buf), fp)) {
 132                 fclose(fp);
 133                 return;
 134         }
 135
 136         m.addr.family = AF_INET;
 137         m.addr.bitlen = 32;
 138         m.addr.bytelen = 4;
 139
 140         while (fgets(buf, sizeof(buf), fp)) {
 141                 struct ma_info *ma;
 142
 143                 if (buf[0] != '\t') {
 144                         sscanf(buf, "%d%s", &m.index, m.name);
 145                         continue;
 146                 }
 147
 148                 if (filter.dev && strcmp(filter.dev, m.name))
 149                         continue;
 150
 151                 sscanf(buf, "%08x%d", (__u32*)&m.addr.data, &m.users);
 152
 153                 ma = malloc(sizeof(m));
 154                 memcpy(ma, &m, sizeof(m));
 155                 maddr_ins(result_p, ma);
 156         }
 157         fclose(fp);
 158 }
 159
 160
 161 void read_igmp6(struct ma_info **result_p)
 162 {
 163         char buf[256];
 164         FILE *fp = fopen("/proc/net/igmp6", "r");
 165
 166         if (!fp)
 167                 return;
 168
 169         while (fgets(buf, sizeof(buf), fp)) {
 170                 char hexa[256];
 171                 struct ma_info m;
 172                 int len;
 173
 174                 memset(&m, 0, sizeof(m));
 175                 sscanf(buf, "%d%s%s%d", &m.index, m.name, hexa, &m.users);
 176
 177                 if (filter.dev && strcmp(filter.dev, m.name))
 178                         continue;
 179
 180                 m.addr.family = AF_INET6;
 181
 182                 len = parse_hex(hexa, (unsigned char*)&m.addr.data, sizeof (m.addr.data));
 183                 if (len >= 0) {
 184                         struct ma_info *ma = malloc(sizeof(m));
 185
 186                         memcpy(ma, &m, sizeof(m));
 187
 188                         ma->addr.bytelen = len;
 189                         ma->addr.bitlen = len<<3;
 190                         maddr_ins(result_p, ma);
 191                 }
 192         }
 193         fclose(fp);
 194 }
 195
 196 static void print_maddr(FILE *fp, struct ma_info *list)
 197 {
 198         fprintf(fp, "\t");
 199
 200         if (list->addr.family == AF_PACKET) {
 201                 SPRINT_BUF(b1);
 202                 fprintf(fp, "link  %s", ll_addr_n2a((unsigned char*)list->addr.data,
 203                                                     list->addr.bytelen, 0,
 204                                                     b1, sizeof(b1)));
 205         } else {
 206                 char abuf[256];
 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,
 221                                     list->addr.data,
 222                                     abuf, sizeof(abuf)));
 223         }
 224         if (list->users != 1)
 225                 fprintf(fp, " users %d", list->users);
 226         if (list->features)
 227                 fprintf(fp, " %s", list->features);
 228         fprintf(fp, "\n");
 229 }
 230
 231 static void print_mlist(FILE *fp, struct ma_info *list)
 232 {
 233         int cur_index = 0;
 234
 235         for (; list; list = list->next) {
 236                 if (oneline) {
 237                         cur_index = list->index;
 238                         fprintf(fp, "%d:\t%s%s", cur_index, list->name, _SL_);
 239                 } else if (cur_index != list->index) {
 240                         cur_index = list->index;
 241                         fprintf(fp, "%d:\t%s\n", cur_index, list->name);
 242                 }
 243                 print_maddr(fp, list);
 244         }
 245 }
 246
 247 static int multiaddr_list(int argc, char **argv)
 248 {
 249         struct ma_info *list = NULL;
 250
 251         if (!filter.family)
 252                 filter.family = preferred_family;
 253
 254         while (argc > 0) {
 255                 if (1) {
 256                         if (strcmp(*argv, "dev") == 0) {
 257                                 NEXT_ARG();
 258                         }
 259                         if (matches(*argv, "help") == 0)
 260                                 usage();
 261                         if (filter.dev)
 262                                 duparg2("dev", *argv);
 263                         filter.dev = *argv;
 264                 }
 265                 argv++; argc--;
 266         }
 267
 268         if (!filter.family || filter.family == AF_PACKET)
 269                 read_dev_mcast(&list);
 270         if (!filter.family || filter.family == AF_INET)
 271                 read_igmp(&list);
 272         if (!filter.family || filter.family == AF_INET6)
 273                 read_igmp6(&list);
 274         print_mlist(stdout, list);
 275         return 0;
 276 }
 277
 278 int multiaddr_modify(int cmd, int argc, char **argv)
 279 {
 280         struct ifreq ifr;
 281         int fd;
 282
 283         memset(&ifr, 0, sizeof(ifr));
 284
 285         if (cmd == RTM_NEWADDR)
 286                 cmd = SIOCADDMULTI;
 287         else
 288                 cmd = SIOCDELMULTI;
 289
 290         while (argc > 0) {
 291                 if (strcmp(*argv, "dev") == 0) {
 292                         NEXT_ARG();
 293                         if (ifr.ifr_name[0])
 294                                 duparg("dev", *argv);
 295                         strncpy(ifr.ifr_name, *argv, IFNAMSIZ);
 296                 } else {
 297                         if (matches(*argv, "address") == 0) {
 298                                 NEXT_ARG();
 299                         }
 300                         if (matches(*argv, "help") == 0)
 301                                 usage();
 302                         if (ifr.ifr_hwaddr.sa_data[0])
 303                                 duparg("address", *argv);
 304                         if (ll_addr_a2n(ifr.ifr_hwaddr.sa_data,
 305                                         14, *argv) < 0) {
 306                                 fprintf(stderr, "Error: \"%s\" is not a legal ll address.\n", *argv);
 307                                 exit(1);
 308                         }
 309                 }
 310                 argc--; argv++;
 311         }
 312         if (ifr.ifr_name[0] == 0) {
 313                 fprintf(stderr, "Not enough information: \"dev\" is required.\n");
 314                 exit(-1);
 315         }
 316
 317         fd = socket(AF_INET, SOCK_DGRAM, 0);
 318         if (fd < 0) {
 319                 perror("Cannot create socket");
 320                 exit(1);
 321         }
 322         if (ioctl(fd, cmd, (char*)&ifr) != 0) {
 323                 perror("ioctl");
 324                 exit(1);
 325         }
 326         close(fd);
 327
 328         exit(0);
 329 }
 330
 331
 332 int do_multiaddr(int argc, char **argv)
 333 {
 334         if (argc < 1)
 335                 return multiaddr_list(0, NULL);
 336         if (matches(*argv, "add") == 0)
 337                 return multiaddr_modify(RTM_NEWADDR, argc-1, argv+1);
 338         if (matches(*argv, "delete") == 0)
 339                 return multiaddr_modify(RTM_DELADDR, argc-1, argv+1);
 340         if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
 341             || matches(*argv, "lst") == 0)
 342                 return multiaddr_list(argc-1, argv+1);
 343         if (matches(*argv, "help") == 0)
 344                 usage();
 345         fprintf(stderr, "Command \"%s\" is unknown, try \"ip maddr help\".\n", *argv);
 346         exit(-1);
 347 }