ip/iplink.c

   1 /*
   2  * iplink.c             "ip link".
   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 <errno.h>
  19 #include <sys/socket.h>
  20 #include <linux/if.h>
  21 #include <linux/if_packet.h>
  22 #include <linux/if_ether.h>
  23 #include <linux/sockios.h>
  24 #include <netinet/in.h>
  25 #include <arpa/inet.h>
  26 #include <string.h>
  27 #include <sys/ioctl.h>
  28 #include <linux/sockios.h>
  29
  30 #include "rt_names.h"
  31 #include "utils.h"
  32 #include "ip_common.h"
  33
  34
  35 static void usage(void) __attribute__((noreturn));
  36
  37 void iplink_usage(void)
  38 {
  39         fprintf(stderr, "Usage: ip link set DEVICE { up | down |\n");
  40         fprintf(stderr, "                            arp { on | off } |\n");
  41         fprintf(stderr, "                            dynamic { on | off } |\n");
  42         fprintf(stderr, "                            multicast { on | off } |\n");
  43         fprintf(stderr, "                            allmulticast { on | off } |\n");
  44         fprintf(stderr, "                            promisc { on | off } |\n");
  45         fprintf(stderr, "                            trailers { on | off } |\n");
  46         fprintf(stderr, "                            txqueuelen PACKETS |\n");
  47         fprintf(stderr, "                            name NEWNAME |\n");
  48         fprintf(stderr, "                            address LLADDR | broadcast LLADDR |\n");
  49         fprintf(stderr, "                            mtu MTU }\n");
  50         fprintf(stderr, "       ip link show [ DEVICE ]\n");
  51         exit(-1);
  52 }
  53
  54 static void usage(void)
  55 {
  56         iplink_usage();
  57 }
  58
  59 static int on_off(char *msg)
  60 {
  61         fprintf(stderr, "Error: argument of \"%s\" must be \"on\" or \"off\"\n", msg);
  62         return -1;
  63 }
  64
  65 static int get_ctl_fd(void)
  66 {
  67         int s_errno;
  68         int fd;
  69
  70         fd = socket(PF_INET, SOCK_DGRAM, 0);
  71         if (fd >= 0)
  72                 return fd;
  73         s_errno = errno;
  74         fd = socket(PF_PACKET, SOCK_DGRAM, 0);
  75         if (fd >= 0)
  76                 return fd;
  77         fd = socket(PF_INET6, SOCK_DGRAM, 0);
  78         if (fd >= 0)
  79                 return fd;
  80         errno = s_errno;
  81         perror("Cannot create control socket");
  82         return -1;
  83 }
  84
  85 static int do_chflags(const char *dev, __u32 flags, __u32 mask)
  86 {
  87         struct ifreq ifr;
  88         int fd;
  89         int err;
  90
  91         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
  92         fd = get_ctl_fd();
  93         if (fd < 0)
  94                 return -1;
  95         err = ioctl(fd, SIOCGIFFLAGS, &ifr);
  96         if (err) {
  97                 perror("SIOCGIFFLAGS");
  98                 close(fd);
  99                 return -1;
 100         }
 101         if ((ifr.ifr_flags^flags)&mask) {
 102                 ifr.ifr_flags &= ~mask;
 103                 ifr.ifr_flags |= mask&flags;
 104                 err = ioctl(fd, SIOCSIFFLAGS, &ifr);
 105                 if (err)
 106                         perror("SIOCSIFFLAGS");
 107         }
 108         close(fd);
 109         return err;
 110 }
 111
 112 static int do_changename(const char *dev, const char *newdev)
 113 {
 114         struct ifreq ifr;
 115         int fd;
 116         int err;
 117
 118         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 119         strncpy(ifr.ifr_newname, newdev, IFNAMSIZ);
 120         fd = get_ctl_fd();
 121         if (fd < 0)
 122                 return -1;
 123         err = ioctl(fd, SIOCSIFNAME, &ifr);
 124         if (err) {
 125                 perror("SIOCSIFNAME");
 126                 close(fd);
 127                 return -1;
 128         }
 129         close(fd);
 130         return err;
 131 }
 132
 133 static int set_qlen(const char *dev, int qlen)
 134 {
 135         struct ifreq ifr;
 136         int s;
 137
 138         s = get_ctl_fd();
 139         if (s < 0)
 140                 return -1;
 141
 142         memset(&ifr, 0, sizeof(ifr));
 143         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 144         ifr.ifr_qlen = qlen;
 145         if (ioctl(s, SIOCSIFTXQLEN, &ifr) < 0) {
 146                 perror("SIOCSIFXQLEN");
 147                 close(s);
 148                 return -1;
 149         }
 150         close(s);
 151
 152         return 0;
 153 }
 154
 155 static int set_mtu(const char *dev, int mtu)
 156 {
 157         struct ifreq ifr;
 158         int s;
 159
 160         s = get_ctl_fd();
 161         if (s < 0)
 162                 return -1;
 163
 164         memset(&ifr, 0, sizeof(ifr));
 165         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 166         ifr.ifr_mtu = mtu;
 167         if (ioctl(s, SIOCSIFMTU, &ifr) < 0) {
 168                 perror("SIOCSIFMTU");
 169                 close(s);
 170                 return -1;
 171         }
 172         close(s);
 173
 174         return 0;
 175 }
 176
 177 static int get_address(const char *dev, int *htype)
 178 {
 179         struct ifreq ifr;
 180         struct sockaddr_ll me;
 181         int alen;
 182         int s;
 183
 184         s = socket(PF_PACKET, SOCK_DGRAM, 0);
 185         if (s < 0) {
 186                 perror("socket(PF_PACKET)");
 187                 return -1;
 188         }
 189
 190         memset(&ifr, 0, sizeof(ifr));
 191         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 192         if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
 193                 perror("SIOCGIFINDEX");
 194                 close(s);
 195                 return -1;
 196         }
 197
 198         memset(&me, 0, sizeof(me));
 199         me.sll_family = AF_PACKET;
 200         me.sll_ifindex = ifr.ifr_ifindex;
 201         me.sll_protocol = htons(ETH_P_LOOP);
 202         if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) {
 203                 perror("bind");
 204                 close(s);
 205                 return -1;
 206         }
 207
 208         alen = sizeof(me);
 209         if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
 210                 perror("getsockname");
 211                 close(s);
 212                 return -1;
 213         }
 214         close(s);
 215         *htype = me.sll_hatype;
 216         return me.sll_halen;
 217 }
 218
 219 static int parse_address(const char *dev, int hatype, int halen, char *lla, struct ifreq *ifr)
 220 {
 221         int alen;
 222
 223         memset(ifr, 0, sizeof(*ifr));
 224         strncpy(ifr->ifr_name, dev, IFNAMSIZ);
 225         ifr->ifr_hwaddr.sa_family = hatype;
 226         alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
 227         if (alen < 0)
 228                 return -1;
 229         if (alen != halen) {
 230                 fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
 231                 return -1;
 232         }
 233         return 0;
 234 }
 235
 236 static int set_address(struct ifreq *ifr, int brd)
 237 {
 238         int s;
 239
 240         s = get_ctl_fd();
 241         if (s < 0)
 242                 return -1;
 243         if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
 244                 perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
 245                 close(s);
 246                 return -1;
 247         }
 248         close(s);
 249         return 0;
 250 }
 251
 252
 253 static int do_set(int argc, char **argv)
 254 {
 255         char *dev = NULL;
 256         __u32 mask = 0;
 257         __u32 flags = 0;
 258         int qlen = -1;
 259         int mtu = -1;
 260         char *newaddr = NULL;
 261         char *newbrd = NULL;
 262         struct ifreq ifr0, ifr1;
 263         char *newname = NULL;
 264         int htype, halen;
 265
 266         while (argc > 0) {
 267                 if (strcmp(*argv, "up") == 0) {
 268                         mask |= IFF_UP;
 269                         flags |= IFF_UP;
 270                 } else if (strcmp(*argv, "down") == 0) {
 271                         mask |= IFF_UP;
 272                         flags &= ~IFF_UP;
 273                 } else if (strcmp(*argv, "name") == 0) {
 274                         NEXT_ARG();
 275                         newname = *argv;
 276                 } else if (matches(*argv, "address") == 0) {
 277                         NEXT_ARG();
 278                         newaddr = *argv;
 279                 } else if (matches(*argv, "broadcast") == 0 ||
 280                            strcmp(*argv, "brd") == 0) {
 281                         NEXT_ARG();
 282                         newbrd = *argv;
 283                 } else if (matches(*argv, "txqueuelen") == 0 ||
 284                            strcmp(*argv, "qlen") == 0 ||
 285                            matches(*argv, "txqlen") == 0) {
 286                         NEXT_ARG();
 287                         if (qlen != -1)
 288                                 duparg("txqueuelen", *argv);
 289                         if (get_integer(&qlen,  *argv, 0))
 290                                 invarg("Invalid \"txqueuelen\" value\n", *argv);
 291                 } else if (strcmp(*argv, "mtu") == 0) {
 292                         NEXT_ARG();
 293                         if (mtu != -1)
 294                                 duparg("mtu", *argv);
 295                         if (get_integer(&mtu, *argv, 0))
 296                                 invarg("Invalid \"mtu\" value\n", *argv);
 297                 } else if (strcmp(*argv, "multicast") == 0) {
 298                         NEXT_ARG();
 299                         mask |= IFF_MULTICAST;
 300                         if (strcmp(*argv, "on") == 0) {
 301                                 flags |= IFF_MULTICAST;
 302                         } else if (strcmp(*argv, "off") == 0) {
 303                                 flags &= ~IFF_MULTICAST;
 304                         } else
 305                                 return on_off("multicast");
 306                 } else if (strcmp(*argv, "allmulticast") == 0) {
 307                         NEXT_ARG();
 308                         mask |= IFF_ALLMULTI;
 309                         if (strcmp(*argv, "on") == 0) {
 310                                 flags |= IFF_ALLMULTI;
 311                         } else if (strcmp(*argv, "off") == 0) {
 312                                 flags &= ~IFF_ALLMULTI;
 313                         } else
 314                                 return on_off("allmulticast");
 315                 } else if (strcmp(*argv, "promisc") == 0) {
 316                         NEXT_ARG();
 317                         mask |= IFF_PROMISC;
 318                         if (strcmp(*argv, "on") == 0) {
 319                                 flags |= IFF_PROMISC;
 320                         } else if (strcmp(*argv, "off") == 0) {
 321                                 flags &= ~IFF_PROMISC;
 322                         } else
 323                                 return on_off("promisc");
 324                 } else if (strcmp(*argv, "trailers") == 0) {
 325                         NEXT_ARG();
 326                         mask |= IFF_NOTRAILERS;
 327                         if (strcmp(*argv, "off") == 0) {
 328                                 flags |= IFF_NOTRAILERS;
 329                         } else if (strcmp(*argv, "on") == 0) {
 330                                 flags &= ~IFF_NOTRAILERS;
 331                         } else
 332                                 return on_off("trailers");
 333                 } else if (strcmp(*argv, "arp") == 0) {
 334                         NEXT_ARG();
 335                         mask |= IFF_NOARP;
 336                         if (strcmp(*argv, "on") == 0) {
 337                                 flags &= ~IFF_NOARP;
 338                         } else if (strcmp(*argv, "off") == 0) {
 339                                 flags |= IFF_NOARP;
 340                         } else
 341                                 return on_off("noarp");
 342 #ifdef IFF_DYNAMIC
 343                 } else if (matches(*argv, "dynamic") == 0) {
 344                         NEXT_ARG();
 345                         mask |= IFF_DYNAMIC;
 346                         if (strcmp(*argv, "on") == 0) {
 347                                 flags |= IFF_DYNAMIC;
 348                         } else if (strcmp(*argv, "off") == 0) {
 349                                 flags &= ~IFF_DYNAMIC;
 350                         } else
 351                                 return on_off("dynamic");
 352 #endif
 353                 } else {
 354                         if (strcmp(*argv, "dev") == 0) {
 355                                 NEXT_ARG();
 356                         }
 357                         if (matches(*argv, "help") == 0)
 358                                 usage();
 359                         if (dev)
 360                                 duparg2("dev", *argv);
 361                         dev = *argv;
 362                 }
 363                 argc--; argv++;
 364         }
 365
 366         if (!dev) {
 367                 fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
 368                 exit(-1);
 369         }
 370
 371         if (newaddr || newbrd) {
 372                 halen = get_address(dev, &htype);
 373                 if (halen < 0)
 374                         return -1;
 375                 if (newaddr) {
 376                         if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
 377                                 return -1;
 378                 }
 379                 if (newbrd) {
 380                         if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
 381                                 return -1;
 382                 }
 383         }
 384
 385         if (newname && strcmp(dev, newname)) {
 386                 if (do_changename(dev, newname) < 0)
 387                         return -1;
 388                 dev = newname;
 389         }
 390         if (qlen != -1) {
 391                 if (set_qlen(dev, qlen) < 0)
 392                         return -1;
 393         }
 394         if (mtu != -1) {
 395                 if (set_mtu(dev, mtu) < 0)
 396                         return -1;
 397         }
 398         if (newaddr || newbrd) {
 399                 if (newbrd) {
 400                         if (set_address(&ifr1, 1) < 0)
 401                                 return -1;
 402                 }
 403                 if (newaddr) {
 404                         if (set_address(&ifr0, 0) < 0)
 405                                 return -1;
 406                 }
 407         }
 408         if (mask)
 409                 return do_chflags(dev, flags, mask);
 410         return 0;
 411 }
 412
 413 int do_iplink(int argc, char **argv)
 414 {
 415         if (argc > 0) {
 416                 if (matches(*argv, "set") == 0)
 417                         return do_set(argc-1, argv+1);
 418                 if (matches(*argv, "show") == 0 ||
 419                     matches(*argv, "lst") == 0 ||
 420                     matches(*argv, "list") == 0)
 421                         return ipaddr_list_link(argc-1, argv+1);
 422                 if (matches(*argv, "help") == 0)
 423                         usage();
 424         } else
 425                 return ipaddr_list_link(0, NULL);
 426
 427         fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
 428         exit(-1);
 429 }