system-linux.c

   1 #define _GNU_SOURCE
   2
   3 #include <sys/socket.h>
   4 #include <sys/ioctl.h>
   5 #include <sys/stat.h>
   6 #include <sys/syscall.h>
   7
   8 #include <linux/rtnetlink.h>
   9 #include <linux/sockios.h>
  10 #include <linux/if_vlan.h>
  11 #include <linux/if_bridge.h>
  12
  13 #include <unistd.h>
  14 #include <string.h>
  15 #include <fcntl.h>
  16 #include <glob.h>
  17
  18 #include <netlink/msg.h>
  19 #include <netlink/attr.h>
  20 #include <netlink/socket.h>
  21 #include <libubox/uloop.h>
  22
  23 #include "netifd.h"
  24 #include "device.h"
  25 #include "system.h"
  26
  27 static int sock_ioctl = -1;
  28 static struct nl_sock *sock_rtnl = NULL;
  29 static struct nl_sock *sock_rtnl_event = NULL;
  30
  31 static void handler_rtnl_event(struct uloop_fd *u, unsigned int events);
  32 static int cb_rtnl_event(struct nl_msg *msg, void *arg);
  33 static struct uloop_fd rtnl_event = {.cb = handler_rtnl_event};
  34 static struct nl_cb *nl_cb_rtnl_event;
  35
  36 int system_init(void)
  37 {
  38         sock_ioctl = socket(AF_LOCAL, SOCK_DGRAM, 0);
  39         fcntl(sock_ioctl, F_SETFD, fcntl(sock_ioctl, F_GETFD) | FD_CLOEXEC);
  40
  41         // Prepare socket for routing / address control
  42         sock_rtnl = nl_socket_alloc();
  43         if (!sock_rtnl)
  44                 return -1;
  45
  46         if (nl_connect(sock_rtnl, NETLINK_ROUTE))
  47                 goto error_free_sock;
  48
  49         // Prepare socket for link events
  50         nl_cb_rtnl_event = nl_cb_alloc(NL_CB_DEFAULT);
  51         if (!nl_cb_rtnl_event)
  52                 goto error_free_sock;
  53
  54         nl_cb_set(nl_cb_rtnl_event, NL_CB_VALID, NL_CB_CUSTOM,
  55                   cb_rtnl_event, NULL);
  56
  57         sock_rtnl_event = nl_socket_alloc();
  58         if (!sock_rtnl_event)
  59                 goto error_free_cb;
  60
  61         if (nl_connect(sock_rtnl_event, NETLINK_ROUTE))
  62                 goto error_free_event;
  63
  64         // Receive network link events form kernel
  65         nl_socket_add_membership(sock_rtnl_event, RTNLGRP_LINK);
  66
  67         rtnl_event.fd = nl_socket_get_fd(sock_rtnl_event);
  68         uloop_fd_add(&rtnl_event, ULOOP_READ | ULOOP_EDGE_TRIGGER);
  69
  70         return 0;
  71
  72 error_free_event:
  73         nl_socket_free(sock_rtnl_event);
  74         sock_rtnl_event = NULL;
  75 error_free_cb:
  76         nl_cb_put(nl_cb_rtnl_event);
  77         nl_cb_rtnl_event = NULL;
  78 error_free_sock:
  79         nl_socket_free(sock_rtnl);
  80         sock_rtnl = NULL;
  81         return -1;
  82 }
  83
  84 // If socket is ready for reading parse netlink events
  85 static void handler_rtnl_event(struct uloop_fd *u, unsigned int events)
  86 {
  87         nl_recvmsgs(sock_rtnl_event, nl_cb_rtnl_event);
  88 }
  89
  90 // Evaluate netlink messages
  91 static int cb_rtnl_event(struct nl_msg *msg, void *arg)
  92 {
  93         struct nlmsghdr *nh = nlmsg_hdr(msg);
  94         struct ifinfomsg *ifi = NLMSG_DATA(nh);
  95         struct nlattr *nla[__IFLA_MAX];
  96
  97         if (nh->nlmsg_type != RTM_DELLINK && nh->nlmsg_type != RTM_NEWLINK)
  98                 goto out;
  99
 100         nlmsg_parse(nh, sizeof(*ifi), nla, __IFLA_MAX - 1, NULL);
 101         if (!nla[IFLA_IFNAME])
 102                 goto out;
 103
 104         struct device *dev = device_get(RTA_DATA(nla[IFLA_IFNAME]), false);
 105         if (!dev)
 106                 goto out;
 107
 108         dev->ifindex = ifi->ifi_index;
 109         device_set_present(dev, (nh->nlmsg_type == RTM_NEWLINK));
 110
 111 out:
 112         return 0;
 113 }
 114
 115 static int system_rtnl_call(struct nl_msg *msg)
 116 {
 117         int s = -(nl_send_auto_complete(sock_rtnl, msg)
 118                         || nl_wait_for_ack(sock_rtnl));
 119         nlmsg_free(msg);
 120         return s;
 121 }
 122
 123 int system_bridge_delbr(struct device *bridge)
 124 {
 125         return ioctl(sock_ioctl, SIOCBRDELBR, bridge->ifname);
 126 }
 127
 128 static int system_bridge_if(const char *bridge, struct device *dev, int cmd, void *data)
 129 {
 130         struct ifreq ifr;
 131         if (dev)
 132                 ifr.ifr_ifindex = dev->ifindex;
 133         else
 134                 ifr.ifr_data = data;
 135         strncpy(ifr.ifr_name, bridge, sizeof(ifr.ifr_name));
 136         return ioctl(sock_ioctl, cmd, &ifr);
 137 }
 138
 139 int system_bridge_addif(struct device *bridge, struct device *dev)
 140 {
 141         return system_bridge_if(bridge->ifname, dev, SIOCBRADDIF, NULL);
 142 }
 143
 144 int system_bridge_delif(struct device *bridge, struct device *dev)
 145 {
 146         return system_bridge_if(bridge->ifname, dev, SIOCBRDELIF, NULL);
 147 }
 148
 149 static bool system_is_bridge(const char *name, char *buf, int buflen)
 150 {
 151         struct stat st;
 152
 153         snprintf(buf, buflen, "/sys/devices/virtual/net/%s/bridge", name);
 154         if (stat(buf, &st) < 0)
 155                 return false;
 156
 157         return true;
 158 }
 159
 160 static char *system_get_bridge(const char *name, char *buf, int buflen)
 161 {
 162         char *path;
 163         ssize_t len;
 164         glob_t gl;
 165
 166         snprintf(buf, buflen, "/sys/devices/virtual/net/*/brif/%s/bridge", name);
 167         if (glob(buf, GLOB_NOSORT, NULL, &gl) < 0)
 168                 return NULL;
 169
 170         if (gl.gl_pathc == 0)
 171                 return NULL;
 172
 173         len = readlink(gl.gl_pathv[0], buf, buflen);
 174         if (len < 0)
 175                 return NULL;
 176
 177         buf[len] = 0;
 178         path = strrchr(buf, '/');
 179         if (!path)
 180                 return NULL;
 181
 182         return path + 1;
 183 }
 184
 185 static int system_if_resolve(struct device *dev)
 186 {
 187         struct ifreq ifr;
 188         strncpy(ifr.ifr_name, dev->ifname, sizeof(ifr.ifr_name));
 189         if (!ioctl(sock_ioctl, SIOCGIFINDEX, &ifr))
 190                 return ifr.ifr_ifindex;
 191         else
 192                 return 0;
 193 }
 194
 195 static int system_if_flags(const char *ifname, unsigned add, unsigned rem)
 196 {
 197         struct ifreq ifr;
 198         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 199         ioctl(sock_ioctl, SIOCGIFFLAGS, &ifr);
 200         ifr.ifr_flags |= add;
 201         ifr.ifr_flags &= ~rem;
 202         return ioctl(sock_ioctl, SIOCSIFFLAGS, &ifr);
 203 }
 204
 205 /*
 206  * Clear bridge (membership) state and bring down device
 207  */
 208 void system_if_clear_state(struct device *dev)
 209 {
 210         char buf[256];
 211         char *bridge;
 212
 213         dev->ifindex = system_if_resolve(dev);
 214         if (!dev->ifindex)
 215                 return;
 216
 217         system_if_flags(dev->ifname, 0, IFF_UP);
 218
 219         if (system_is_bridge(dev->ifname, buf, sizeof(buf))) {
 220                 D(SYSTEM, "Delete existing bridge named '%s'\n", dev->ifname);
 221                 system_bridge_delbr(dev);
 222                 return;
 223         }
 224
 225         bridge = system_get_bridge(dev->ifname, buf, sizeof(buf));
 226         if (bridge) {
 227                 D(SYSTEM, "Remove device '%s' from bridge '%s'\n", dev->ifname, bridge);
 228                 system_bridge_if(bridge, dev, SIOCBRDELIF, NULL);
 229         }
 230 }
 231
 232 static inline unsigned long
 233 sec_to_jiffies(int val)
 234 {
 235         return (unsigned long) val * 100;
 236 }
 237
 238 int system_bridge_addbr(struct device *bridge, struct bridge_config *cfg)
 239 {
 240         unsigned long args[4] = {};
 241
 242         if (ioctl(sock_ioctl, SIOCBRADDBR, bridge->ifname) < 0)
 243                 return -1;
 244
 245         args[0] = BRCTL_SET_BRIDGE_STP_STATE;
 246         args[1] = !!cfg->stp;
 247         system_bridge_if(bridge->ifname, NULL, SIOCDEVPRIVATE, &args);
 248
 249         args[0] = BRCTL_SET_BRIDGE_FORWARD_DELAY;
 250         args[1] = sec_to_jiffies(cfg->forward_delay);
 251         system_bridge_if(bridge->ifname, NULL, SIOCDEVPRIVATE, &args);
 252
 253         if (cfg->flags & BRIDGE_OPT_AGEING_TIME) {
 254                 args[0] = BRCTL_SET_AGEING_TIME;
 255                 args[1] = sec_to_jiffies(cfg->ageing_time);
 256                 system_bridge_if(bridge->ifname, NULL, SIOCDEVPRIVATE, &args);
 257         }
 258
 259         if (cfg->flags & BRIDGE_OPT_HELLO_TIME) {
 260                 args[0] = BRCTL_SET_BRIDGE_HELLO_TIME;
 261                 args[1] = sec_to_jiffies(cfg->hello_time);
 262                 system_bridge_if(bridge->ifname, NULL, SIOCDEVPRIVATE, &args);
 263         }
 264
 265         if (cfg->flags & BRIDGE_OPT_MAX_AGE) {
 266                 args[0] = BRCTL_SET_BRIDGE_MAX_AGE;
 267                 args[1] = sec_to_jiffies(cfg->max_age);
 268                 system_bridge_if(bridge->ifname, NULL, SIOCDEVPRIVATE, &args);
 269         }
 270
 271         return 0;
 272 }
 273
 274 static int system_vlan(struct device *dev, int id)
 275 {
 276         struct vlan_ioctl_args ifr = {
 277                 .cmd = SET_VLAN_NAME_TYPE_CMD,
 278                 .u.name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD,
 279         };
 280
 281         ioctl(sock_ioctl, SIOCSIFVLAN, &ifr);
 282
 283         if (id < 0) {
 284                 ifr.cmd = DEL_VLAN_CMD;
 285                 ifr.u.VID = 0;
 286         } else {
 287                 ifr.cmd = ADD_VLAN_CMD;
 288                 ifr.u.VID = id;
 289         }
 290         strncpy(ifr.device1, dev->ifname, sizeof(ifr.device1));
 291         return ioctl(sock_ioctl, SIOCSIFVLAN, &ifr);
 292 }
 293
 294 int system_vlan_add(struct device *dev, int id)
 295 {
 296         return system_vlan(dev, id);
 297 }
 298
 299 int system_vlan_del(struct device *dev)
 300 {
 301         return system_vlan(dev, -1);
 302 }
 303
 304 int system_if_up(struct device *dev)
 305 {
 306         dev->ifindex = system_if_resolve(dev);
 307         return system_if_flags(dev->ifname, IFF_UP, 0);
 308 }
 309
 310 int system_if_down(struct device *dev)
 311 {
 312         return system_if_flags(dev->ifname, 0, IFF_UP);
 313 }
 314
 315 int system_if_check(struct device *dev)
 316 {
 317         device_set_present(dev, (system_if_resolve(dev) >= 0));
 318         return 0;
 319 }
 320
 321 int system_if_dump_stats(struct device *dev, struct blob_buf *b)
 322 {
 323         const char *const counters[] = {
 324                 "collisions",     "rx_frame_errors",   "tx_compressed",
 325                 "multicast",      "rx_length_errors",  "tx_dropped",
 326                 "rx_bytes",       "rx_missed_errors",  "tx_errors",
 327                 "rx_compressed",  "rx_over_errors",    "tx_fifo_errors",
 328                 "rx_crc_errors",  "rx_packets",        "tx_heartbeat_errors",
 329                 "rx_dropped",     "tx_aborted_errors", "tx_packets",
 330                 "rx_errors",      "tx_bytes",          "tx_window_errors",
 331                 "rx_fifo_errors", "tx_carrier_errors",
 332         };
 333         char buf[64];
 334         int stats_dir;
 335         int i, fd, len;
 336
 337         snprintf(buf, sizeof(buf), "/sys/class/net/%s/statistics", dev->ifname);
 338         stats_dir = open(buf, O_DIRECTORY);
 339         if (stats_dir < 0)
 340                 return -1;
 341
 342         for (i = 0; i < ARRAY_SIZE(counters); i++) {
 343                 fd = openat(stats_dir, counters[i], O_RDONLY);
 344                 if (fd < 0)
 345                         continue;
 346
 347 retry:
 348                 len = read(fd, buf, sizeof(buf));
 349                 if (len < 0) {
 350                         if (errno == EINTR)
 351                                 goto retry;
 352                         continue;
 353                 }
 354
 355                 buf[len] = 0;
 356                 blobmsg_add_u32(b, counters[i], strtoul(buf, NULL, 0));
 357                 close(fd);
 358         }
 359
 360         close(stats_dir);
 361         return 0;
 362 }
 363
 364 static int system_addr(struct device *dev, struct device_addr *addr, int cmd)
 365 {
 366         int alen = ((addr->flags & DEVADDR_FAMILY) == DEVADDR_INET4) ? 4 : 16;
 367         struct ifaddrmsg ifa = {
 368                 .ifa_family = (alen == 4) ? AF_INET : AF_INET6,
 369                 .ifa_prefixlen = addr->mask,
 370                 .ifa_index = dev->ifindex,
 371         };
 372
 373         struct nl_msg *msg = nlmsg_alloc_simple(cmd, 0);
 374         if (!msg)
 375                 return -1;
 376
 377         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 378         nla_put(msg, IFA_LOCAL, alen, &addr->addr);
 379         return system_rtnl_call(msg);
 380 }
 381
 382 int system_add_address(struct device *dev, struct device_addr *addr)
 383 {
 384         return system_addr(dev, addr, RTM_NEWADDR);
 385 }
 386
 387 int system_del_address(struct device *dev, struct device_addr *addr)
 388 {
 389         return system_addr(dev, addr, RTM_DELADDR);
 390 }
 391
 392 static int system_rt(struct device *dev, struct device_route *route, int cmd)
 393 {
 394         int alen = ((route->flags & DEVADDR_FAMILY) == DEVADDR_INET4) ? 4 : 16;
 395         bool have_gw;
 396         unsigned int flags = 0;
 397
 398         if (alen == 4)
 399                 have_gw = !!route->nexthop.in.s_addr;
 400         else
 401                 have_gw = route->nexthop.in6.s6_addr32[0] ||
 402                         route->nexthop.in6.s6_addr32[1] ||
 403                         route->nexthop.in6.s6_addr32[2] ||
 404                         route->nexthop.in6.s6_addr32[3];
 405
 406         unsigned char scope = (cmd == RTM_DELROUTE) ? RT_SCOPE_NOWHERE :
 407                         (have_gw) ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK;
 408
 409         struct rtmsg rtm = {
 410                 .rtm_family = (alen == 4) ? AF_INET : AF_INET6,
 411                 .rtm_dst_len = route->mask,
 412                 .rtm_table = RT_TABLE_MAIN,
 413                 .rtm_protocol = RTPROT_BOOT,
 414                 .rtm_scope = scope,
 415                 .rtm_type = (cmd == RTM_DELROUTE) ? 0: RTN_UNICAST,
 416         };
 417
 418         if (cmd == RTM_NEWROUTE)
 419                 flags |= NLM_F_CREATE | NLM_F_REPLACE;
 420
 421         struct nl_msg *msg = nlmsg_alloc_simple(cmd, flags);
 422         if (!msg)
 423                 return -1;
 424
 425         nlmsg_append(msg, &rtm, sizeof(rtm), 0);
 426
 427         if (route->mask)
 428                 nla_put(msg, RTA_DST, alen, &route->addr);
 429
 430         if (have_gw)
 431                 nla_put(msg, RTA_GATEWAY, alen, &route->nexthop);
 432
 433         if (route->flags & DEVADDR_DEVICE)
 434                 nla_put_u32(msg, RTA_OIF, dev->ifindex);
 435
 436         return system_rtnl_call(msg);
 437 }
 438
 439 int system_add_route(struct device *dev, struct device_route *route)
 440 {
 441         return system_rt(dev, route, RTM_NEWROUTE);
 442 }
 443
 444 int system_del_route(struct device *dev, struct device_route *route)
 445 {
 446         return system_rt(dev, route, RTM_DELROUTE);
 447 }
 448
 449 int system_flush_routes(void)
 450 {
 451         const char *names[] = {
 452                 "/proc/sys/net/ipv4/route/flush",
 453                 "/proc/sys/net/ipv6/route/flush"
 454         };
 455         int fd, i;
 456
 457         for (i = 0; i < ARRAY_SIZE(names); i++) {
 458                 fd = open(names[i], O_WRONLY);
 459                 if (fd < 0)
 460                         continue;
 461
 462                 write(fd, "-1", 2);
 463                 close(fd);
 464         }
 465         return 0;
 466 }
 467
 468 time_t system_get_rtime(void)
 469 {
 470         struct timespec ts;
 471         struct timeval tv;
 472
 473         if (syscall(__NR_clock_gettime, CLOCK_MONOTONIC, &ts) == 0)
 474                 return ts.tv_sec;
 475
 476         if (gettimeofday(&tv, NULL) == 0)
 477                 return tv.tv_sec;
 478
 479         return 0;
 480 }