release/src/router/rp-pppoe/src/plugin.c

   1 /***********************************************************************
   2 *
   3 * plugin.c
   4 *
   5 * pppd plugin for kernel-mode PPPoE on Linux
   6 *
   7 * Copyright (C) 2001-2012 by Roaring Penguin Software Inc.
   8 * Portions copyright 2000 Michal Ostrowski and Jamal Hadi Salim.
   9 *
  10 * Much code and many ideas derived from pppoe plugin by Michal
  11 * Ostrowski and Jamal Hadi Salim, which carries this copyright:
  12 *
  13 * Copyright 2000 Michal Ostrowski <mostrows@styx.uwaterloo.ca>,
  14 *                Jamal Hadi Salim <hadi@cyberus.ca>
  15 * Borrows heavily from the PPPoATM plugin by Mitchell Blank Jr.,
  16 * which is based in part on work from Jens Axboe and Paul Mackerras.
  17 *
  18 * This program is free software; you can redistribute it and/or
  19 * modify it under the terms of the GNU General Public License
  20 * as published by the Free Software Foundation; either version
  21 * 2 of the License, or (at your option) any later version.
  22 *
  23 * LIC: GPL
  24 *
  25 ***********************************************************************/
  26
  27 static char const RCSID[] =
  28 "$Id$";
  29
  30 #define _GNU_SOURCE 1
  31 #include "pppoe.h"
  32
  33 #include "pppd/pppd.h"
  34 #include "pppd/fsm.h"
  35 #include "pppd/lcp.h"
  36 #include "pppd/ipcp.h"
  37 #include "pppd/ccp.h"
  38 /* #include "pppd/pathnames.h" */
  39
  40 #include <linux/types.h>
  41 #include <syslog.h>
  42 #include <sys/ioctl.h>
  43 #include <sys/types.h>
  44 #include <sys/socket.h>
  45 #include <sys/stat.h>
  46 #include <string.h>
  47 #include <stdlib.h>
  48 #include <errno.h>
  49 #include <unistd.h>
  50 #include <fcntl.h>
  51 #include <signal.h>
  52 #include <net/ethernet.h>
  53 #include <net/if_arp.h>
  54 #include <linux/ppp_defs.h>
  55 #include <linux/if_pppox.h>
  56
  57 #ifndef _ROOT_PATH
  58 #define _ROOT_PATH ""
  59 #endif
  60
  61 #define _PATH_ETHOPT         _ROOT_PATH "/etc/ppp/options."
  62
  63 char pppd_version[] = VERSION;
  64
  65 static int seen_devnam[2] = {0, 0};
  66 static char *pppoe_reqd_mac = NULL;
  67
  68 /* From sys-linux.c in pppd -- MUST FIX THIS! */
  69 extern int new_style_driver;
  70
  71 char *pppd_pppoe_service = NULL;
  72 static char *acName = NULL;
  73 static char *existingSession = NULL;
  74 static int printACNames = 0;
  75
  76 static int PPPoEDevnameHook(char *cmd, char **argv, int doit);
  77 static option_t Options[] = {
  78     { "device name", o_wild, (void *) &PPPoEDevnameHook,
  79       "PPPoE device name",
  80       OPT_DEVNAM | OPT_PRIVFIX | OPT_NOARG  | OPT_A2STRVAL | OPT_STATIC,
  81       devnam},
  82     { "rp_pppoe_service", o_string, &pppd_pppoe_service,
  83       "Desired PPPoE service name" },
  84     { "rp_pppoe_ac",      o_string, &acName,
  85       "Desired PPPoE access concentrator name" },
  86     { "rp_pppoe_sess",    o_string, &existingSession,
  87       "Attach to existing session (sessid:macaddr)" },
  88     { "rp_pppoe_verbose", o_int, &printACNames,
  89       "Be verbose about discovered access concentrators"},
  90     { "rp_pppoe_mac", o_string, &pppoe_reqd_mac,
  91       "Only connect to specified MAC address" },
  92     { NULL }
  93 };
  94 int (*OldDevnameHook)(char *cmd, char **argv, int doit) = NULL;
  95 static PPPoEConnection *conn = NULL;
  96
  97 /**********************************************************************
  98  * %FUNCTION: PPPOEInitDevice
  99  * %ARGUMENTS:
 100  * None
 101  * %RETURNS:
 102  *
 103  * %DESCRIPTION:
 104  * Initializes PPPoE device.
 105  ***********************************************************************/
 106 static int
 107 PPPOEInitDevice(void)
 108 {
 109     conn = malloc(sizeof(PPPoEConnection));
 110     if (!conn) {
 111         fatal("Could not allocate memory for PPPoE session");
 112     }
 113     memset(conn, 0, sizeof(PPPoEConnection));
 114     if (acName) {
 115         SET_STRING(conn->acName, acName);
 116     }
 117     if (pppd_pppoe_service) {
 118         SET_STRING(conn->serviceName, pppd_pppoe_service);
 119     }
 120     SET_STRING(conn->ifName, devnam);
 121     conn->discoverySocket = -1;
 122     conn->sessionSocket = -1;
 123     conn->useHostUniq = 1;
 124     conn->printACNames = printACNames;
 125     conn->discoveryTimeout = PADI_TIMEOUT;
 126     return 1;
 127 }
 128
 129 /**********************************************************************
 130  * %FUNCTION: PPPOEConnectDevice
 131  * %ARGUMENTS:
 132  * None
 133  * %RETURNS:
 134  * Non-negative if all goes well; -1 otherwise
 135  * %DESCRIPTION:
 136  * Connects PPPoE device.
 137  ***********************************************************************/
 138 static int
 139 PPPOEConnectDevice(void)
 140 {
 141     struct sockaddr_pppox sp;
 142     struct ifreq ifr;
 143     int s;
 144
 145     /* Restore configuration */
 146     lcp_allowoptions[0].mru = conn->mtu;
 147     lcp_wantoptions[0].mru = conn->mru;
 148
 149     /* Update maximum MRU */
 150     s = socket(AF_INET, SOCK_DGRAM, 0);
 151     if (s < 0) {
 152         error("Can't get MTU for %s: %m", conn->ifName);
 153         return -1;
 154     }
 155     strncpy(ifr.ifr_name, conn->ifName, sizeof(ifr.ifr_name));
 156     if (ioctl(s, SIOCGIFMTU, &ifr) < 0) {
 157         error("Can't get MTU for %s: %m", conn->ifName);
 158         close(s);
 159         return -1;
 160     }
 161     close(s);
 162
 163     if (lcp_allowoptions[0].mru > ifr.ifr_mtu - TOTAL_OVERHEAD) {
 164         lcp_allowoptions[0].mru = ifr.ifr_mtu - TOTAL_OVERHEAD;
 165     }
 166     if (lcp_wantoptions[0].mru > ifr.ifr_mtu - TOTAL_OVERHEAD) {
 167         lcp_wantoptions[0].mru = ifr.ifr_mtu - TOTAL_OVERHEAD;
 168     }
 169
 170     /* Open session socket before discovery phase, to avoid losing session */
 171     /* packets sent by peer just after PADS packet (noted on some Cisco    */
 172     /* server equipment).                                                  */
 173     /* Opening this socket just before waitForPADS in the discovery()      */
 174     /* function would be more appropriate, but it would mess-up the code   */
 175     conn->sessionSocket = socket(AF_PPPOX, SOCK_STREAM, PX_PROTO_OE);
 176     if (conn->sessionSocket < 0) {
 177         error("Failed to create PPPoE socket: %m");
 178         return -1;
 179     }
 180
 181     if (acName) {
 182         SET_STRING(conn->acName, acName);
 183     }
 184     if (pppd_pppoe_service) {
 185         SET_STRING(conn->serviceName, pppd_pppoe_service);
 186     }
 187
 188     strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
 189     if (existingSession) {
 190         unsigned int mac[ETH_ALEN];
 191         int i, ses;
 192         if (sscanf(existingSession, "%d:%x:%x:%x:%x:%x:%x",
 193                    &ses, &mac[0], &mac[1], &mac[2],
 194                    &mac[3], &mac[4], &mac[5]) != 7) {
 195             fatal("Illegal value for rp_pppoe_sess option");
 196         }
 197         conn->session = htons(ses);
 198         for (i=0; i<ETH_ALEN; i++) {
 199             conn->peerEth[i] = (unsigned char) mac[i];
 200         }
 201     } else {
 202         conn->discoverySocket =
 203             openInterface(conn->ifName, Eth_PPPOE_Discovery, conn->myEth, NULL);
 204         discovery(conn);
 205         if (conn->discoveryState != STATE_SESSION) {
 206             error("Unable to complete PPPoE Discovery");
 207             return -1;
 208         }
 209     }
 210
 211     /* Set PPPoE session-number for further consumption */
 212     ppp_session_number = ntohs(conn->session);
 213
 214     sp.sa_family = AF_PPPOX;
 215     sp.sa_protocol = PX_PROTO_OE;
 216     sp.sa_addr.pppoe.sid = conn->session;
 217     memcpy(sp.sa_addr.pppoe.dev, conn->ifName, IFNAMSIZ);
 218     memcpy(sp.sa_addr.pppoe.remote, conn->peerEth, ETH_ALEN);
 219
 220     /* Set remote_number for ServPoET */
 221     sprintf(remote_number, "%02X:%02X:%02X:%02X:%02X:%02X",
 222             (unsigned) conn->peerEth[0],
 223             (unsigned) conn->peerEth[1],
 224             (unsigned) conn->peerEth[2],
 225             (unsigned) conn->peerEth[3],
 226             (unsigned) conn->peerEth[4],
 227             (unsigned) conn->peerEth[5]);
 228
 229     warn("Connected to %02X:%02X:%02X:%02X:%02X:%02X via interface %s",
 230          (unsigned) conn->peerEth[0],
 231          (unsigned) conn->peerEth[1],
 232          (unsigned) conn->peerEth[2],
 233          (unsigned) conn->peerEth[3],
 234          (unsigned) conn->peerEth[4],
 235          (unsigned) conn->peerEth[5],
 236          conn->ifName);
 237
 238     script_setenv("MACREMOTE", remote_number, 0);
 239
 240     if (connect(conn->sessionSocket, (struct sockaddr *) &sp,
 241                 sizeof(struct sockaddr_pppox)) < 0) {
 242         error("Failed to connect PPPoE socket: %d %m", errno);
 243         return -1;
 244     }
 245
 246     return conn->sessionSocket;
 247 }
 248
 249 static void
 250 PPPOESendConfig(int mtu,
 251                 u_int32_t asyncmap,
 252                 int pcomp,
 253                 int accomp)
 254 {
 255     int sock;
 256     struct ifreq ifr;
 257
 258     if (mtu > MAX_PPPOE_MTU) {
 259         warn("Couldn't increase MTU to %d", mtu);
 260         mtu = MAX_PPPOE_MTU;
 261     }
 262     sock = socket(AF_INET, SOCK_DGRAM, 0);
 263     if (sock < 0) {
 264         warn("Couldn't create IP socket: %m");
 265         return;
 266     }
 267     strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 268     ifr.ifr_mtu = mtu;
 269     if (ioctl(sock, SIOCSIFMTU, &ifr) < 0) {
 270         warn("ioctl(SIOCSIFMTU): %m");
 271         return;
 272     }
 273     (void) close (sock);
 274 }
 275
 276
 277 static void
 278 PPPOERecvConfig(int mru,
 279                 u_int32_t asyncmap,
 280                 int pcomp,
 281                 int accomp)
 282 {
 283     if (mru > MAX_PPPOE_MTU) {
 284         warn("Couldn't increase MRU to %d", mru);
 285     }
 286 }
 287
 288 /**********************************************************************
 289  * %FUNCTION: PPPOEDisconnectDevice
 290  * %ARGUMENTS:
 291  * None
 292  * %RETURNS:
 293  * Nothing
 294  * %DESCRIPTION:
 295  * Disconnects PPPoE device
 296  ***********************************************************************/
 297 static void
 298 PPPOEDisconnectDevice(void)
 299 {
 300     struct sockaddr_pppox sp;
 301
 302     sp.sa_family = AF_PPPOX;
 303     sp.sa_protocol = PX_PROTO_OE;
 304     sp.sa_addr.pppoe.sid = 0;
 305     memcpy(sp.sa_addr.pppoe.dev, conn->ifName, IFNAMSIZ);
 306     memcpy(sp.sa_addr.pppoe.remote, conn->peerEth, ETH_ALEN);
 307     if (connect(conn->sessionSocket, (struct sockaddr *) &sp,
 308                 sizeof(struct sockaddr_pppox)) < 0) {
 309         fatal("Failed to disconnect PPPoE socket: %d %m", errno);
 310         return;
 311     }
 312     close(conn->sessionSocket);
 313     close(conn->discoverySocket);
 314
 315 }
 316
 317 static void
 318 PPPOEDeviceOptions(void)
 319 {
 320     char buf[256];
 321     snprintf(buf, 256, _PATH_ETHOPT "%s",devnam);
 322     if(!options_from_file(buf, 0, 0, 1))
 323         exit(EXIT_OPTION_ERROR);
 324
 325 }
 326
 327 struct channel pppoe_channel;
 328
 329 /**********************************************************************
 330  * %FUNCTION: PPPoEDevnameHook
 331  * %ARGUMENTS:
 332  * cmd -- the command (actually, the device name
 333  * argv -- argument vector
 334  * doit -- if non-zero, set device name.  Otherwise, just check if possible
 335  * %RETURNS:
 336  * 1 if we will handle this device; 0 otherwise.
 337  * %DESCRIPTION:
 338  * Checks if name is a valid interface name; if so, returns 1.  Also
 339  * sets up devnam (string representation of device).
 340  ***********************************************************************/
 341 static int
 342 PPPoEDevnameHook(char *cmd, char **argv, int doit)
 343 {
 344     int r = 1;
 345     int fd;
 346     struct ifreq ifr;
 347     int seen_idx = doit ? 1 : 0;
 348
 349     /* If "devnam" has already been set, ignore.
 350        This prevents kernel from doing modprobes against random
 351        pppd arguments that happen to begin with "nic-", "eth" or "br"
 352
 353        Ideally, "nix-ethXXX" should be supplied immediately after
 354        "plugin rp-pppoe.so"
 355
 356        Patch based on suggestion from Mike Ireton.
 357     */
 358     if (seen_devnam[seen_idx]) {
 359         if (OldDevnameHook) return OldDevnameHook(cmd, argv, doit);
 360         return 0;
 361     }
 362
 363     /* Only do it if name is "ethXXX" or "brXXX" or what was specified
 364        by rp_pppoe_dev option (ugh). */
 365     /* Can also specify nic-XXXX in which case the nic- is stripped off. */
 366     if (!strncmp(cmd, "nic-", 4)) {
 367         cmd += 4;
 368     } else {
 369         if (strncmp(cmd, "eth", 3) &&
 370             strncmp(cmd, "br", 2)) {
 371             if (OldDevnameHook) return OldDevnameHook(cmd, argv, doit);
 372             return 0;
 373         }
 374     }
 375
 376     /* Open a socket */
 377     if ((fd = socket(PF_PACKET, SOCK_RAW, 0)) < 0) {
 378         r = 0;
 379     }
 380
 381     /* Try getting interface index */
 382     if (r) {
 383         strncpy(ifr.ifr_name, cmd, IFNAMSIZ);
 384         if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
 385             r = 0;
 386         } else {
 387             if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
 388                 r = 0;
 389             } else {
 390                 if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
 391                     error("Interface %s not Ethernet", cmd);
 392                     r=0;
 393                 }
 394             }
 395         }
 396     }
 397
 398     /* Close socket */
 399     close(fd);
 400     if (r) {
 401         seen_devnam[seen_idx] = 1;
 402         if (doit) {
 403             strncpy(devnam, cmd, sizeof(devnam));
 404             if (the_channel != &pppoe_channel) {
 405
 406                 the_channel = &pppoe_channel;
 407                 modem = 0;
 408
 409                 lcp_allowoptions[0].neg_accompression = 0;
 410                 lcp_wantoptions[0].neg_accompression = 0;
 411
 412                 lcp_allowoptions[0].neg_asyncmap = 0;
 413                 lcp_wantoptions[0].neg_asyncmap = 0;
 414
 415                 lcp_allowoptions[0].neg_pcompression = 0;
 416                 lcp_wantoptions[0].neg_pcompression = 0;
 417
 418                 ipcp_allowoptions[0].neg_vj=0;
 419                 ipcp_wantoptions[0].neg_vj=0;
 420
 421                 ccp_allowoptions[0].deflate = 0 ;
 422                 ccp_wantoptions[0].deflate = 0 ;
 423
 424                 ccp_allowoptions[0].bsd_compress = 0;
 425                 ccp_wantoptions[0].bsd_compress = 0;
 426
 427
 428                 PPPOEInitDevice();
 429             }
 430         }
 431         return 1;
 432     }
 433
 434     if (OldDevnameHook) r = OldDevnameHook(cmd, argv, doit);
 435     return r;
 436 }
 437
 438 /**********************************************************************
 439  * %FUNCTION: plugin_init
 440  * %ARGUMENTS:
 441  * None
 442  * %RETURNS:
 443  * Nothing
 444  * %DESCRIPTION:
 445  * Initializes hooks for pppd plugin
 446  ***********************************************************************/
 447 void
 448 plugin_init(void)
 449 {
 450     if (!ppp_available() && !new_style_driver) {
 451         fatal("Linux kernel does not support PPPoE -- are you running 2.4.x?");
 452     }
 453
 454     add_options(Options);
 455
 456     info("RP-PPPoE plugin version %s compiled against pppd %s",
 457          RP_VERSION, VERSION);
 458 }
 459
 460 /**********************************************************************
 461 *%FUNCTION: fatalSys
 462 *%ARGUMENTS:
 463 * str -- error message
 464 *%RETURNS:
 465 * Nothing
 466 *%DESCRIPTION:
 467 * Prints a message plus the errno value to stderr and syslog and exits.
 468 *
 469 ***********************************************************************/
 470 void
 471 fatalSys(char const *str)
 472 {
 473     char buf[1024];
 474     int i = errno;
 475     sprintf(buf, "%.256s: %.256s", str, strerror(i));
 476     printErr(buf);
 477     sprintf(buf, "RP-PPPoE: %.256s: %.256s", str, strerror(i));
 478     sendPADT(conn, buf);
 479     exit(1);
 480 }
 481
 482 /**********************************************************************
 483 *%FUNCTION: rp_fatal
 484 *%ARGUMENTS:
 485 * str -- error message
 486 *%RETURNS:
 487 * Nothing
 488 *%DESCRIPTION:
 489 * Prints a message to stderr and syslog and exits.
 490 ***********************************************************************/
 491 void
 492 rp_fatal(char const *str)
 493 {
 494     printErr(str);
 495     sendPADTf(conn, "RP-PPPoE: %.256s", str);
 496     exit(1);
 497 }
 498
 499 /**********************************************************************
 500 *%FUNCTION: sysErr
 501 *%ARGUMENTS:
 502 * str -- error message
 503 *%RETURNS:
 504 * Nothing
 505 *%DESCRIPTION:
 506 * Prints a message plus the errno value to syslog.
 507 ***********************************************************************/
 508 void
 509 sysErr(char const *str)
 510 {
 511     rp_fatal(str);
 512 }
 513
 514 void pppoe_check_options(void)
 515 {
 516     unsigned int mac[ETH_ALEN];
 517     int i;
 518
 519     if (pppoe_reqd_mac != NULL) {
 520         if (sscanf(pppoe_reqd_mac, "%x:%x:%x:%x:%x:%x",
 521                    &mac[0], &mac[1], &mac[2], &mac[3],
 522                    &mac[4], &mac[5]) != ETH_ALEN) {
 523             option_error("cannot parse pppoe-mac option value");
 524             exit(EXIT_OPTION_ERROR);
 525         }
 526         for (i = 0; i < 6; ++i)
 527             conn->req_peer_mac[i] = mac[i];
 528         conn->req_peer = 1;
 529     }
 530
 531     lcp_allowoptions[0].neg_accompression = 0;
 532     lcp_wantoptions[0].neg_accompression = 0;
 533
 534     lcp_allowoptions[0].neg_asyncmap = 0;
 535     lcp_wantoptions[0].neg_asyncmap = 0;
 536
 537     lcp_allowoptions[0].neg_pcompression = 0;
 538     lcp_wantoptions[0].neg_pcompression = 0;
 539
 540     if (lcp_allowoptions[0].mru > MAX_PPPOE_MTU) {
 541         lcp_allowoptions[0].mru = MAX_PPPOE_MTU;
 542     }
 543     if (lcp_wantoptions[0].mru > MAX_PPPOE_MTU) {
 544         lcp_wantoptions[0].mru = MAX_PPPOE_MTU;
 545     }
 546
 547     /* Save configuration */
 548     conn->mtu = lcp_allowoptions[0].mru;
 549     conn->mru = lcp_wantoptions[0].mru;
 550
 551     ccp_allowoptions[0].deflate = 0;
 552     ccp_wantoptions[0].deflate = 0;
 553
 554     ipcp_allowoptions[0].neg_vj = 0;
 555     ipcp_wantoptions[0].neg_vj = 0;
 556
 557     ccp_allowoptions[0].bsd_compress = 0;
 558     ccp_wantoptions[0].bsd_compress = 0;
 559 }
 560
 561 struct channel pppoe_channel = {
 562     .options = Options,
 563     .process_extra_options = &PPPOEDeviceOptions,
 564     .check_options = &pppoe_check_options,
 565     .connect = &PPPOEConnectDevice,
 566     .disconnect = &PPPOEDisconnectDevice,
 567     .establish_ppp = &generic_establish_ppp,
 568     .disestablish_ppp = &generic_disestablish_ppp,
 569     .send_config = &PPPOESendConfig,
 570     .recv_config = &PPPOERecvConfig,
 571     .close = NULL,
 572     .cleanup = NULL
 573 };