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         socklen_t 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,
 220                 char *lla, struct ifreq *ifr)
 221 {
 222         int alen;
 223
 224         memset(ifr, 0, sizeof(*ifr));
 225         strncpy(ifr->ifr_name, dev, IFNAMSIZ);
 226         ifr->ifr_hwaddr.sa_family = hatype;
 227         alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
 228         if (alen < 0)
 229                 return -1;
 230         if (alen != halen) {
 231                 fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
 232                 return -1;
 233         }
 234         return 0;
 235 }
 236
 237 static int set_address(struct ifreq *ifr, int brd)
 238 {
 239         int s;
 240
 241         s = get_ctl_fd();
 242         if (s < 0)
 243                 return -1;
 244         if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
 245                 perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
 246                 close(s);
 247                 return -1;
 248         }
 249         close(s);
 250         return 0;
 251 }
 252
 253
 254 static int do_set(int argc, char **argv)
 255 {
 256         char *dev = NULL;
 257         __u32 mask = 0;
 258         __u32 flags = 0;
 259         int qlen = -1;
 260         int mtu = -1;
 261         char *newaddr = NULL;
 262         char *newbrd = NULL;
 263         struct ifreq ifr0, ifr1;
 264         char *newname = NULL;
 265         int htype, halen;
 266
 267         while (argc > 0) {
 268                 if (strcmp(*argv, "up") == 0) {
 269                         mask |= IFF_UP;
 270                         flags |= IFF_UP;
 271                 } else if (strcmp(*argv, "down") == 0) {
 272                         mask |= IFF_UP;
 273                         flags &= ~IFF_UP;
 274                 } else if (strcmp(*argv, "name") == 0) {
 275                         NEXT_ARG();
 276                         newname = *argv;
 277                 } else if (matches(*argv, "address") == 0) {
 278                         NEXT_ARG();
 279                         newaddr = *argv;
 280                 } else if (matches(*argv, "broadcast") == 0 ||
 281                            strcmp(*argv, "brd") == 0) {
 282                         NEXT_ARG();
 283                         newbrd = *argv;
 284                 } else if (matches(*argv, "txqueuelen") == 0 ||
 285                            strcmp(*argv, "qlen") == 0 ||
 286                            matches(*argv, "txqlen") == 0) {
 287                         NEXT_ARG();
 288                         if (qlen != -1)
 289                                 duparg("txqueuelen", *argv);
 290                         if (get_integer(&qlen,  *argv, 0))
 291                                 invarg("Invalid \"txqueuelen\" value\n", *argv);
 292                 } else if (strcmp(*argv, "mtu") == 0) {
 293                         NEXT_ARG();
 294                         if (mtu != -1)
 295                                 duparg("mtu", *argv);
 296                         if (get_integer(&mtu, *argv, 0))
 297                                 invarg("Invalid \"mtu\" value\n", *argv);
 298                 } else if (strcmp(*argv, "multicast") == 0) {
 299                         NEXT_ARG();
 300                         mask |= IFF_MULTICAST;
 301                         if (strcmp(*argv, "on") == 0) {
 302                                 flags |= IFF_MULTICAST;
 303                         } else if (strcmp(*argv, "off") == 0) {
 304                                 flags &= ~IFF_MULTICAST;
 305                         } else
 306                                 return on_off("multicast");
 307                 } else if (strcmp(*argv, "allmulticast") == 0) {
 308                         NEXT_ARG();
 309                         mask |= IFF_ALLMULTI;
 310                         if (strcmp(*argv, "on") == 0) {
 311                                 flags |= IFF_ALLMULTI;
 312                         } else if (strcmp(*argv, "off") == 0) {
 313                                 flags &= ~IFF_ALLMULTI;
 314                         } else
 315                                 return on_off("allmulticast");
 316                 } else if (strcmp(*argv, "promisc") == 0) {
 317                         NEXT_ARG();
 318                         mask |= IFF_PROMISC;
 319                         if (strcmp(*argv, "on") == 0) {
 320                                 flags |= IFF_PROMISC;
 321                         } else if (strcmp(*argv, "off") == 0) {
 322                                 flags &= ~IFF_PROMISC;
 323                         } else
 324                                 return on_off("promisc");
 325                 } else if (strcmp(*argv, "trailers") == 0) {
 326                         NEXT_ARG();
 327                         mask |= IFF_NOTRAILERS;
 328                         if (strcmp(*argv, "off") == 0) {
 329                                 flags |= IFF_NOTRAILERS;
 330                         } else if (strcmp(*argv, "on") == 0) {
 331                                 flags &= ~IFF_NOTRAILERS;
 332                         } else
 333                                 return on_off("trailers");
 334                 } else if (strcmp(*argv, "arp") == 0) {
 335                         NEXT_ARG();
 336                         mask |= IFF_NOARP;
 337                         if (strcmp(*argv, "on") == 0) {
 338                                 flags &= ~IFF_NOARP;
 339                         } else if (strcmp(*argv, "off") == 0) {
 340                                 flags |= IFF_NOARP;
 341                         } else
 342                                 return on_off("noarp");
 343 #ifdef IFF_DYNAMIC
 344                 } else if (matches(*argv, "dynamic") == 0) {
 345                         NEXT_ARG();
 346                         mask |= IFF_DYNAMIC;
 347                         if (strcmp(*argv, "on") == 0) {
 348                                 flags |= IFF_DYNAMIC;
 349                         } else if (strcmp(*argv, "off") == 0) {
 350                                 flags &= ~IFF_DYNAMIC;
 351                         } else
 352                                 return on_off("dynamic");
 353 #endif
 354                 } else {
 355                         if (strcmp(*argv, "dev") == 0) {
 356                                 NEXT_ARG();
 357                         }
 358                         if (matches(*argv, "help") == 0)
 359                                 usage();
 360                         if (dev)
 361                                 duparg2("dev", *argv);
 362                         dev = *argv;
 363                 }
 364                 argc--; argv++;
 365         }
 366
 367         if (!dev) {
 368                 fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
 369                 exit(-1);
 370         }
 371
 372         if (newaddr || newbrd) {
 373                 halen = get_address(dev, &htype);
 374                 if (halen < 0)
 375                         return -1;
 376                 if (newaddr) {
 377                         if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
 378                                 return -1;
 379                 }
 380                 if (newbrd) {
 381                         if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
 382                                 return -1;
 383                 }
 384         }
 385
 386         if (newname && strcmp(dev, newname)) {
 387                 if (do_changename(dev, newname) < 0)
 388                         return -1;
 389                 dev = newname;
 390         }
 391         if (qlen != -1) {
 392                 if (set_qlen(dev, qlen) < 0)
 393                         return -1;
 394         }
 395         if (mtu != -1) {
 396                 if (set_mtu(dev, mtu) < 0)
 397                         return -1;
 398         }
 399         if (newaddr || newbrd) {
 400                 if (newbrd) {
 401                         if (set_address(&ifr1, 1) < 0)
 402                                 return -1;
 403                 }
 404                 if (newaddr) {
 405                         if (set_address(&ifr0, 0) < 0)
 406                                 return -1;
 407                 }
 408         }
 409         if (mask)
 410                 return do_chflags(dev, flags, mask);
 411         return 0;
 412 }
 413
 414 int do_iplink(int argc, char **argv)
 415 {
 416         if (argc > 0) {
 417                 if (matches(*argv, "set") == 0)
 418                         return do_set(argc-1, argv+1);
 419                 if (matches(*argv, "show") == 0 ||
 420                     matches(*argv, "lst") == 0 ||
 421                     matches(*argv, "list") == 0)
 422                         return ipaddr_list_link(argc-1, argv+1);
 423                 if (matches(*argv, "help") == 0)
 424                         usage();
 425         } else
 426                 return ipaddr_list_link(0, NULL);
 427
 428         fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
 429         exit(-1);
 430 }