1/* vi: set sw=4 ts=4: */ 2/* 3 * iplink.c "ip link". 4 * 5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 6 * 7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. 8 */ 9#include <net/if.h> 10#include <net/if_packet.h> 11#include <netpacket/packet.h> 12#include <net/ethernet.h> 13 14#include "ip_common.h" /* #include "libbb.h" is inside */ 15#include "rt_names.h" 16#include "utils.h" 17 18#ifndef IFLA_LINKINFO 19# define IFLA_LINKINFO 18 20# define IFLA_INFO_KIND 1 21#endif 22 23/* taken from linux/sockios.h */ 24#define SIOCSIFNAME 0x8923 /* set interface name */ 25 26/* Exits on error */ 27static int get_ctl_fd(void) 28{ 29 int fd; 30 31 fd = socket(PF_INET, SOCK_DGRAM, 0); 32 if (fd >= 0) 33 return fd; 34 fd = socket(PF_PACKET, SOCK_DGRAM, 0); 35 if (fd >= 0) 36 return fd; 37 return xsocket(PF_INET6, SOCK_DGRAM, 0); 38} 39 40/* Exits on error */ 41static void do_chflags(char *dev, uint32_t flags, uint32_t mask) 42{ 43 struct ifreq ifr; 44 int fd; 45 46 strncpy_IFNAMSIZ(ifr.ifr_name, dev); 47 fd = get_ctl_fd(); 48 xioctl(fd, SIOCGIFFLAGS, &ifr); 49 if ((ifr.ifr_flags ^ flags) & mask) { 50 ifr.ifr_flags &= ~mask; 51 ifr.ifr_flags |= mask & flags; 52 xioctl(fd, SIOCSIFFLAGS, &ifr); 53 } 54 close(fd); 55} 56 57/* Exits on error */ 58static void do_changename(char *dev, char *newdev) 59{ 60 struct ifreq ifr; 61 int fd; 62 63 strncpy_IFNAMSIZ(ifr.ifr_name, dev); 64 strncpy_IFNAMSIZ(ifr.ifr_newname, newdev); 65 fd = get_ctl_fd(); 66 xioctl(fd, SIOCSIFNAME, &ifr); 67 close(fd); 68} 69 70/* Exits on error */ 71static void set_qlen(char *dev, int qlen) 72{ 73 struct ifreq ifr; 74 int s; 75 76 s = get_ctl_fd(); 77 memset(&ifr, 0, sizeof(ifr)); 78 strncpy_IFNAMSIZ(ifr.ifr_name, dev); 79 ifr.ifr_qlen = qlen; 80 xioctl(s, SIOCSIFTXQLEN, &ifr); 81 close(s); 82} 83 84/* Exits on error */ 85static void set_mtu(char *dev, int mtu) 86{ 87 struct ifreq ifr; 88 int s; 89 90 s = get_ctl_fd(); 91 memset(&ifr, 0, sizeof(ifr)); 92 strncpy_IFNAMSIZ(ifr.ifr_name, dev); 93 ifr.ifr_mtu = mtu; 94 xioctl(s, SIOCSIFMTU, &ifr); 95 close(s); 96} 97 98/* Exits on error */ 99static int get_address(char *dev, int *htype) 100{ 101 struct ifreq ifr; 102 struct sockaddr_ll me; 103 socklen_t alen; 104 int s; 105 106 s = xsocket(PF_PACKET, SOCK_DGRAM, 0); 107 108 memset(&ifr, 0, sizeof(ifr)); 109 strncpy_IFNAMSIZ(ifr.ifr_name, dev); 110 xioctl(s, SIOCGIFINDEX, &ifr); 111 112 memset(&me, 0, sizeof(me)); 113 me.sll_family = AF_PACKET; 114 me.sll_ifindex = ifr.ifr_ifindex; 115 me.sll_protocol = htons(ETH_P_LOOP); 116 xbind(s, (struct sockaddr*)&me, sizeof(me)); 117 alen = sizeof(me); 118 getsockname(s, (struct sockaddr*)&me, &alen); 119 //never happens: 120 //if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) 121 // bb_perror_msg_and_die("getsockname"); 122 close(s); 123 *htype = me.sll_hatype; 124 return me.sll_halen; 125} 126 127/* Exits on error */ 128static void parse_address(char *dev, int hatype, int halen, char *lla, struct ifreq *ifr) 129{ 130 int alen; 131 132 memset(ifr, 0, sizeof(*ifr)); 133 strncpy_IFNAMSIZ(ifr->ifr_name, dev); 134 ifr->ifr_hwaddr.sa_family = hatype; 135 136 alen = hatype == 1/*ARPHRD_ETHER*/ ? 14/*ETH_HLEN*/ : 19/*INFINIBAND_HLEN*/; 137 alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla); 138 if (alen < 0) 139 exit(EXIT_FAILURE); 140 if (alen != halen) { 141 bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen); 142 } 143} 144 145/* Exits on error */ 146static void set_address(struct ifreq *ifr, int brd) 147{ 148 int s; 149 150 s = get_ctl_fd(); 151 if (brd) 152 xioctl(s, SIOCSIFHWBROADCAST, ifr); 153 else 154 xioctl(s, SIOCSIFHWADDR, ifr); 155 close(s); 156} 157 158 159static void die_must_be_on_off(const char *msg) NORETURN; 160static void die_must_be_on_off(const char *msg) 161{ 162 bb_error_msg_and_die("argument of \"%s\" must be \"on\" or \"off\"", msg); 163} 164 165/* Return value becomes exitcode. It's okay to not return at all */ 166static int do_set(char **argv) 167{ 168 char *dev = NULL; 169 uint32_t mask = 0; 170 uint32_t flags = 0; 171 int qlen = -1; 172 int mtu = -1; 173 char *newaddr = NULL; 174 char *newbrd = NULL; 175 struct ifreq ifr0, ifr1; 176 char *newname = NULL; 177 int htype, halen; 178 static const char keywords[] ALIGN1 = 179 "up\0""down\0""name\0""mtu\0""qlen\0""multicast\0" 180 "arp\0""address\0""dev\0"; 181 enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_qlen, ARG_multicast, 182 ARG_arp, ARG_addr, ARG_dev }; 183 static const char str_on_off[] ALIGN1 = "on\0""off\0"; 184 enum { PARM_on = 0, PARM_off }; 185 smalluint key; 186 187 while (*argv) { 188 /* substring search ensures that e.g. "addr" and "address" 189 * are both accepted */ 190 key = index_in_substrings(keywords, *argv); 191 if (key == ARG_up) { 192 mask |= IFF_UP; 193 flags |= IFF_UP; 194 } else if (key == ARG_down) { 195 mask |= IFF_UP; 196 flags &= ~IFF_UP; 197 } else if (key == ARG_name) { 198 NEXT_ARG(); 199 newname = *argv; 200 } else if (key == ARG_mtu) { 201 NEXT_ARG(); 202 if (mtu != -1) 203 duparg("mtu", *argv); 204 mtu = get_unsigned(*argv, "mtu"); 205 } else if (key == ARG_qlen) { 206 NEXT_ARG(); 207 if (qlen != -1) 208 duparg("qlen", *argv); 209 qlen = get_unsigned(*argv, "qlen"); 210 } else if (key == ARG_addr) { 211 NEXT_ARG(); 212 newaddr = *argv; 213 } else if (key >= ARG_dev) { 214 if (key == ARG_dev) { 215 NEXT_ARG(); 216 } 217 if (dev) 218 duparg2("dev", *argv); 219 dev = *argv; 220 } else { 221 int param; 222 NEXT_ARG(); 223 param = index_in_strings(str_on_off, *argv); 224 if (key == ARG_multicast) { 225 if (param < 0) 226 die_must_be_on_off("multicast"); 227 mask |= IFF_MULTICAST; 228 if (param == PARM_on) 229 flags |= IFF_MULTICAST; 230 else 231 flags &= ~IFF_MULTICAST; 232 } else if (key == ARG_arp) { 233 if (param < 0) 234 die_must_be_on_off("arp"); 235 mask |= IFF_NOARP; 236 if (param == PARM_on) 237 flags &= ~IFF_NOARP; 238 else 239 flags |= IFF_NOARP; 240 } 241 } 242 argv++; 243 } 244 245 if (!dev) { 246 bb_error_msg_and_die(bb_msg_requires_arg, "\"dev\""); 247 } 248 249 if (newaddr || newbrd) { 250 halen = get_address(dev, &htype); 251 if (newaddr) { 252 parse_address(dev, htype, halen, newaddr, &ifr0); 253 set_address(&ifr0, 0); 254 } 255 if (newbrd) { 256 parse_address(dev, htype, halen, newbrd, &ifr1); 257 set_address(&ifr1, 1); 258 } 259 } 260 261 if (newname && strcmp(dev, newname)) { 262 do_changename(dev, newname); 263 dev = newname; 264 } 265 if (qlen != -1) { 266 set_qlen(dev, qlen); 267 } 268 if (mtu != -1) { 269 set_mtu(dev, mtu); 270 } 271 if (mask) 272 do_chflags(dev, flags, mask); 273 return 0; 274} 275 276static int ipaddr_list_link(char **argv) 277{ 278 preferred_family = AF_PACKET; 279 return ipaddr_list_or_flush(argv, 0); 280} 281 282#ifndef NLMSG_TAIL 283#define NLMSG_TAIL(nmsg) \ 284 ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len))) 285#endif 286/* Return value becomes exitcode. It's okay to not return at all */ 287static int do_change(char **argv, const unsigned rtm) 288{ 289 static const char keywords[] ALIGN1 = 290 "link\0""name\0""type\0""dev\0"; 291 enum { 292 ARG_link, 293 ARG_name, 294 ARG_type, 295 ARG_dev, 296 }; 297 struct rtnl_handle rth; 298 struct { 299 struct nlmsghdr n; 300 struct ifinfomsg i; 301 char buf[1024]; 302 } req; 303 smalluint arg; 304 char *name_str = NULL, *link_str = NULL, *type_str = NULL, *dev_str = NULL; 305 306 memset(&req, 0, sizeof(req)); 307 308 req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); 309 req.n.nlmsg_flags = NLM_F_REQUEST; 310 req.n.nlmsg_type = rtm; 311 req.i.ifi_family = preferred_family; 312 if (rtm == RTM_NEWLINK) 313 req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL; 314 315 while (*argv) { 316 arg = index_in_substrings(keywords, *argv); 317 if (arg == ARG_link) { 318 NEXT_ARG(); 319 link_str = *argv; 320 } else if (arg == ARG_name) { 321 NEXT_ARG(); 322 name_str = *argv; 323 } else if (arg == ARG_type) { 324 NEXT_ARG(); 325 type_str = *argv; 326 } else { 327 if (arg == ARG_dev) { 328 if (dev_str) 329 duparg(*argv, "dev"); 330 NEXT_ARG(); 331 } 332 dev_str = *argv; 333 } 334 argv++; 335 } 336 xrtnl_open(&rth); 337 ll_init_map(&rth); 338 if (type_str) { 339 struct rtattr *linkinfo = NLMSG_TAIL(&req.n); 340 341 addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0); 342 addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type_str, 343 strlen(type_str)); 344 linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo; 345 } 346 if (rtm != RTM_NEWLINK) { 347 if (!dev_str) 348 return 1; /* Need a device to delete */ 349 req.i.ifi_index = xll_name_to_index(dev_str); 350 } else { 351 if (!name_str) 352 name_str = dev_str; 353 if (link_str) { 354 int idx = xll_name_to_index(link_str); 355 addattr_l(&req.n, sizeof(req), IFLA_LINK, &idx, 4); 356 } 357 } 358 if (name_str) { 359 const size_t name_len = strlen(name_str) + 1; 360 if (name_len < 2 || name_len > IFNAMSIZ) 361 invarg(name_str, "name"); 362 addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name_str, name_len); 363 } 364 if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0) 365 return 2; 366 return 0; 367} 368 369/* Return value becomes exitcode. It's okay to not return at all */ 370int do_iplink(char **argv) 371{ 372 static const char keywords[] ALIGN1 = 373 "add\0""delete\0""set\0""show\0""lst\0""list\0"; 374 if (*argv) { 375 smalluint key = index_in_substrings(keywords, *argv); 376 if (key > 5) /* invalid argument */ 377 bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name); 378 argv++; 379 if (key <= 1) /* add/delete */ 380 return do_change(argv, key ? RTM_DELLINK : RTM_NEWLINK); 381 else if (key == 2) /* set */ 382 return do_set(argv); 383 } 384 /* show, lst, list */ 385 return ipaddr_list_link(argv); 386} 387