release/src/router/busybox/networking/libiproute/iplink.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   4  *
   5  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   6  */
   7 #include <net/if.h>
   8 #include <net/if_packet.h>
   9 #include <netpacket/packet.h>
  10 #include <netinet/if_ether.h>
  11
  12 #include "ip_common.h"  /* #include "libbb.h" is inside */
  13 #include "rt_names.h"
  14 #include "utils.h"
  15
  16 #ifndef IFLA_LINKINFO
  17 # define IFLA_LINKINFO 18
  18 # define IFLA_INFO_KIND 1
  19 #endif
  20
  21 /* taken from linux/sockios.h */
  22 #define SIOCSIFNAME  0x8923  /* set interface name */
  23
  24 /* Exits on error */
  25 static int get_ctl_fd(void)
  26 {
  27         int fd;
  28
  29         fd = socket(PF_INET, SOCK_DGRAM, 0);
  30         if (fd >= 0)
  31                 return fd;
  32         fd = socket(PF_PACKET, SOCK_DGRAM, 0);
  33         if (fd >= 0)
  34                 return fd;
  35         return xsocket(PF_INET6, SOCK_DGRAM, 0);
  36 }
  37
  38 /* Exits on error */
  39 static void do_chflags(char *dev, uint32_t flags, uint32_t mask)
  40 {
  41         struct ifreq ifr;
  42         int fd;
  43
  44         strncpy_IFNAMSIZ(ifr.ifr_name, dev);
  45         fd = get_ctl_fd();
  46         xioctl(fd, SIOCGIFFLAGS, &ifr);
  47         if ((ifr.ifr_flags ^ flags) & mask) {
  48                 ifr.ifr_flags &= ~mask;
  49                 ifr.ifr_flags |= mask & flags;
  50                 xioctl(fd, SIOCSIFFLAGS, &ifr);
  51         }
  52         close(fd);
  53 }
  54
  55 /* Exits on error */
  56 static void do_changename(char *dev, char *newdev)
  57 {
  58         struct ifreq ifr;
  59         int fd;
  60
  61         strncpy_IFNAMSIZ(ifr.ifr_name, dev);
  62         strncpy_IFNAMSIZ(ifr.ifr_newname, newdev);
  63         fd = get_ctl_fd();
  64         xioctl(fd, SIOCSIFNAME, &ifr);
  65         close(fd);
  66 }
  67
  68 /* Exits on error */
  69 static void set_qlen(char *dev, int qlen)
  70 {
  71         struct ifreq ifr;
  72         int s;
  73
  74         s = get_ctl_fd();
  75         memset(&ifr, 0, sizeof(ifr));
  76         strncpy_IFNAMSIZ(ifr.ifr_name, dev);
  77         ifr.ifr_qlen = qlen;
  78         xioctl(s, SIOCSIFTXQLEN, &ifr);
  79         close(s);
  80 }
  81
  82 /* Exits on error */
  83 static void set_mtu(char *dev, int mtu)
  84 {
  85         struct ifreq ifr;
  86         int s;
  87
  88         s = get_ctl_fd();
  89         memset(&ifr, 0, sizeof(ifr));
  90         strncpy_IFNAMSIZ(ifr.ifr_name, dev);
  91         ifr.ifr_mtu = mtu;
  92         xioctl(s, SIOCSIFMTU, &ifr);
  93         close(s);
  94 }
  95
  96 /* Exits on error */
  97 static int get_address(char *dev, int *htype)
  98 {
  99         struct ifreq ifr;
 100         struct sockaddr_ll me;
 101         socklen_t alen;
 102         int s;
 103
 104         s = xsocket(PF_PACKET, SOCK_DGRAM, 0);
 105
 106         memset(&ifr, 0, sizeof(ifr));
 107         strncpy_IFNAMSIZ(ifr.ifr_name, dev);
 108         xioctl(s, SIOCGIFINDEX, &ifr);
 109
 110         memset(&me, 0, sizeof(me));
 111         me.sll_family = AF_PACKET;
 112         me.sll_ifindex = ifr.ifr_ifindex;
 113         me.sll_protocol = htons(ETH_P_LOOP);
 114         xbind(s, (struct sockaddr*)&me, sizeof(me));
 115         alen = sizeof(me);
 116         getsockname(s, (struct sockaddr*)&me, &alen);
 117         //never happens:
 118         //if (getsockname(s, (struct sockaddr*)&me, &alen) == -1)
 119         //      bb_perror_msg_and_die("getsockname");
 120         close(s);
 121         *htype = me.sll_hatype;
 122         return me.sll_halen;
 123 }
 124
 125 /* Exits on error */
 126 static void parse_address(char *dev, int hatype, int halen, char *lla, struct ifreq *ifr)
 127 {
 128         int alen;
 129
 130         memset(ifr, 0, sizeof(*ifr));
 131         strncpy_IFNAMSIZ(ifr->ifr_name, dev);
 132         ifr->ifr_hwaddr.sa_family = hatype;
 133
 134         alen = hatype == 1/*ARPHRD_ETHER*/ ? 14/*ETH_HLEN*/ : 19/*INFINIBAND_HLEN*/;
 135         alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla);
 136         if (alen < 0)
 137                 exit(EXIT_FAILURE);
 138         if (alen != halen) {
 139                 bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen);
 140         }
 141 }
 142
 143 /* Exits on error */
 144 static void set_address(struct ifreq *ifr, int brd)
 145 {
 146         int s;
 147
 148         s = get_ctl_fd();
 149         if (brd)
 150                 xioctl(s, SIOCSIFHWBROADCAST, ifr);
 151         else
 152                 xioctl(s, SIOCSIFHWADDR, ifr);
 153         close(s);
 154 }
 155
 156
 157 static void die_must_be_on_off(const char *msg) NORETURN;
 158 static void die_must_be_on_off(const char *msg)
 159 {
 160         bb_error_msg_and_die("argument of \"%s\" must be \"on\" or \"off\"", msg);
 161 }
 162
 163 /* Return value becomes exitcode. It's okay to not return at all */
 164 static int do_set(char **argv)
 165 {
 166         char *dev = NULL;
 167         uint32_t mask = 0;
 168         uint32_t flags = 0;
 169         int qlen = -1;
 170         int mtu = -1;
 171         char *newaddr = NULL;
 172         char *newbrd = NULL;
 173         struct ifreq ifr0, ifr1;
 174         char *newname = NULL;
 175         int htype, halen;
 176         static const char keywords[] ALIGN1 =
 177                 "up\0""down\0""name\0""mtu\0""qlen\0""multicast\0"
 178                 "arp\0""address\0""dev\0";
 179         enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_qlen, ARG_multicast,
 180                 ARG_arp, ARG_addr, ARG_dev };
 181         static const char str_on_off[] ALIGN1 = "on\0""off\0";
 182         enum { PARM_on = 0, PARM_off };
 183         smalluint key;
 184
 185         while (*argv) {
 186                 /* substring search ensures that e.g. "addr" and "address"
 187                  * are both accepted */
 188                 key = index_in_substrings(keywords, *argv);
 189                 if (key == ARG_up) {
 190                         mask |= IFF_UP;
 191                         flags |= IFF_UP;
 192                 } else if (key == ARG_down) {
 193                         mask |= IFF_UP;
 194                         flags &= ~IFF_UP;
 195                 } else if (key == ARG_name) {
 196                         NEXT_ARG();
 197                         newname = *argv;
 198                 } else if (key == ARG_mtu) {
 199                         NEXT_ARG();
 200                         if (mtu != -1)
 201                                 duparg("mtu", *argv);
 202                         mtu = get_unsigned(*argv, "mtu");
 203                 } else if (key == ARG_qlen) {
 204                         NEXT_ARG();
 205                         if (qlen != -1)
 206                                 duparg("qlen", *argv);
 207                         qlen = get_unsigned(*argv, "qlen");
 208                 } else if (key == ARG_addr) {
 209                         NEXT_ARG();
 210                         newaddr = *argv;
 211                 } else if (key >= ARG_dev) {
 212                         if (key == ARG_dev) {
 213                                 NEXT_ARG();
 214                         }
 215                         if (dev)
 216                                 duparg2("dev", *argv);
 217                         dev = *argv;
 218                 } else {
 219                         int param;
 220                         NEXT_ARG();
 221                         param = index_in_strings(str_on_off, *argv);
 222                         if (key == ARG_multicast) {
 223                                 if (param < 0)
 224                                         die_must_be_on_off("multicast");
 225                                 mask |= IFF_MULTICAST;
 226                                 if (param == PARM_on)
 227                                         flags |= IFF_MULTICAST;
 228                                 else
 229                                         flags &= ~IFF_MULTICAST;
 230                         } else if (key == ARG_arp) {
 231                                 if (param < 0)
 232                                         die_must_be_on_off("arp");
 233                                 mask |= IFF_NOARP;
 234                                 if (param == PARM_on)
 235                                         flags &= ~IFF_NOARP;
 236                                 else
 237                                         flags |= IFF_NOARP;
 238                         }
 239                 }
 240                 argv++;
 241         }
 242
 243         if (!dev) {
 244                 bb_error_msg_and_die(bb_msg_requires_arg, "\"dev\"");
 245         }
 246
 247         if (newaddr || newbrd) {
 248                 halen = get_address(dev, &htype);
 249                 if (newaddr) {
 250                         parse_address(dev, htype, halen, newaddr, &ifr0);
 251                         set_address(&ifr0, 0);
 252                 }
 253                 if (newbrd) {
 254                         parse_address(dev, htype, halen, newbrd, &ifr1);
 255                         set_address(&ifr1, 1);
 256                 }
 257         }
 258
 259         if (newname && strcmp(dev, newname)) {
 260                 do_changename(dev, newname);
 261                 dev = newname;
 262         }
 263         if (qlen != -1) {
 264                 set_qlen(dev, qlen);
 265         }
 266         if (mtu != -1) {
 267                 set_mtu(dev, mtu);
 268         }
 269         if (mask)
 270                 do_chflags(dev, flags, mask);
 271         return 0;
 272 }
 273
 274 static int ipaddr_list_link(char **argv)
 275 {
 276         preferred_family = AF_PACKET;
 277         return ipaddr_list_or_flush(argv, 0);
 278 }
 279
 280 #ifndef NLMSG_TAIL
 281 #define NLMSG_TAIL(nmsg) \
 282         ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
 283 #endif
 284 /* Return value becomes exitcode. It's okay to not return at all */
 285 static int do_change(char **argv, const unsigned rtm)
 286 {
 287         static const char keywords[] ALIGN1 =
 288                 "link\0""name\0""type\0""dev\0";
 289         enum {
 290                 ARG_link,
 291                 ARG_name,
 292                 ARG_type,
 293                 ARG_dev,
 294         };
 295         struct rtnl_handle rth;
 296         struct {
 297                 struct nlmsghdr  n;
 298                 struct ifinfomsg i;
 299                 char             buf[1024];
 300         } req;
 301         smalluint arg;
 302         char *name_str = NULL, *link_str = NULL, *type_str = NULL, *dev_str = NULL;
 303
 304         memset(&req, 0, sizeof(req));
 305
 306         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
 307         req.n.nlmsg_flags = NLM_F_REQUEST;
 308         req.n.nlmsg_type = rtm;
 309         req.i.ifi_family = preferred_family;
 310         if (rtm == RTM_NEWLINK)
 311                 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
 312
 313         while (*argv) {
 314                 arg = index_in_substrings(keywords, *argv);
 315                 if (arg == ARG_link) {
 316                         NEXT_ARG();
 317                         link_str = *argv;
 318                 } else if (arg == ARG_name) {
 319                         NEXT_ARG();
 320                         name_str = *argv;
 321                 } else if (arg == ARG_type) {
 322                         NEXT_ARG();
 323                         type_str = *argv;
 324                 } else {
 325                         if (arg == ARG_dev) {
 326                                 if (dev_str)
 327                                         duparg(*argv, "dev");
 328                                 NEXT_ARG();
 329                         }
 330                         dev_str = *argv;
 331                 }
 332                 argv++;
 333         }
 334         xrtnl_open(&rth);
 335         ll_init_map(&rth);
 336         if (type_str) {
 337                 struct rtattr *linkinfo = NLMSG_TAIL(&req.n);
 338
 339                 addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
 340                 addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type_str,
 341                                 strlen(type_str));
 342                 linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
 343         }
 344         if (rtm != RTM_NEWLINK) {
 345                 if (!dev_str)
 346                         return 1; /* Need a device to delete */
 347                 req.i.ifi_index = xll_name_to_index(dev_str);
 348         } else {
 349                 if (!name_str)
 350                         name_str = dev_str;
 351                 if (link_str) {
 352                         int idx = xll_name_to_index(link_str);
 353                         addattr_l(&req.n, sizeof(req), IFLA_LINK, &idx, 4);
 354                 }
 355         }
 356         if (name_str) {
 357                 const size_t name_len = strlen(name_str) + 1;
 358                 if (name_len < 2 || name_len > IFNAMSIZ)
 359                         invarg(name_str, "name");
 360                 addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name_str, name_len);
 361         }
 362         if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
 363                 return 2;
 364         return 0;
 365 }
 366
 367 /* Return value becomes exitcode. It's okay to not return at all */
 368 int FAST_FUNC do_iplink(char **argv)
 369 {
 370         static const char keywords[] ALIGN1 =
 371                 "add\0""delete\0""set\0""show\0""lst\0""list\0";
 372         if (*argv) {
 373                 smalluint key = index_in_substrings(keywords, *argv);
 374                 if (key > 5) /* invalid argument */
 375                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 376                 argv++;
 377                 if (key <= 1) /* add/delete */
 378                         return do_change(argv, key ? RTM_DELLINK : RTM_NEWLINK);
 379                 else if (key == 2) /* set */
 380                         return do_set(argv);
 381         }
 382         /* show, lst, list */
 383         return ipaddr_list_link(argv);
 384 }