1/***********************************************************************
2*
3* plugin.c
4*
5* pppd plugin for kernel-mode PPPoE on Linux
6*
7* Copyright (C) 2001 by Roaring Penguin Software Inc., Michal Ostrowski
8* 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***********************************************************************/
24
25static char const RCSID[] =
26"Id: plugin.c,v 1.17 2008/06/15 04:35:50 paulus Exp ";
27
28#define _GNU_SOURCE 1
29#include "pppoe.h"
30
31#include "pppd/pppd.h"
32#include "pppd/fsm.h"
33#include "pppd/lcp.h"
34#include "pppd/ipcp.h"
35#include "pppd/ccp.h"
36/* #include "pppd/pathnames.h" */
37
38#include <linux/types.h>
39#include <sys/ioctl.h>
40#include <sys/types.h>
41#include <sys/socket.h>
42#include <sys/stat.h>
43#include <string.h>
44#include <stdlib.h>
45#include <errno.h>
46#include <unistd.h>
47#include <fcntl.h>
48#include <signal.h>
49#include <net/if_arp.h>
50#include <linux/ppp_defs.h>
51#include <linux/if_pppox.h>
52
53#ifndef _ROOT_PATH
54#define _ROOT_PATH ""
55#endif
56
57#define _PATH_ETHOPT         _ROOT_PATH "/etc/ppp/options."
58
59char pppd_version[] = VERSION;
60
61/* From sys-linux.c in pppd -- MUST FIX THIS! */
62extern int new_style_driver;
63
64char *pppd_pppoe_service = NULL;
65static char *acName = NULL;
66static char *existingSession = NULL;
67static int printACNames = 0;
68static char *pppoe_reqd_mac = NULL;
69unsigned char pppoe_reqd_mac_addr[6];
70static char *pppoe_host_uniq;
71static int pppoe_padi_timeout = PADI_TIMEOUT;
72static int pppoe_padi_attempts = MAX_PADI_ATTEMPTS;
73
74static int PPPoEDevnameHook(char *cmd, char **argv, int doit);
75static option_t Options[] = {
76    { "device name", o_wild, (void *) &PPPoEDevnameHook,
77      "PPPoE device name",
78      OPT_DEVNAM | OPT_PRIVFIX | OPT_NOARG  | OPT_A2STRVAL | OPT_STATIC,
79      devnam},
80    { "pppoe-service", o_string, &pppd_pppoe_service,
81      "Desired PPPoE service name" },
82    { "rp_pppoe_service", o_string, &pppd_pppoe_service,
83      "Legacy alias for pppoe-service", OPT_ALIAS },
84    { "pppoe-ac",      o_string, &acName,
85      "Desired PPPoE access concentrator name" },
86    { "rp_pppoe_ac",      o_string, &acName,
87      "Legacy alias for pppoe-ac", OPT_ALIAS },
88    { "pppoe-sess",    o_string, &existingSession,
89      "Attach to existing session (sessid:macaddr)" },
90    { "rp_pppoe_sess",    o_string, &existingSession,
91      "Legacy alias for pppoe-sess", OPT_ALIAS },
92    { "pppoe-verbose", o_int, &printACNames,
93      "Be verbose about discovered access concentrators" },
94    { "rp_pppoe_verbose", o_int, &printACNames,
95      "Legacy alias for pppoe-verbose", OPT_ALIAS },
96    { "pppoe-mac", o_string, &pppoe_reqd_mac,
97      "Only connect to specified MAC address" },
98    { "pppoe-host-uniq", o_string, &pppoe_host_uniq,
99      "Set the Host-Uniq to the supplied hex string" },
100    { "host-uniq", o_string, &pppoe_host_uniq,
101      "Legacy alias for pppoe-host-uniq", OPT_ALIAS },
102    { "pppoe-padi-timeout", o_int, &pppoe_padi_timeout,
103      "Initial timeout for discovery packets in seconds" },
104    { "pppoe-padi-attempts", o_int, &pppoe_padi_attempts,
105      "Number of discovery attempts" },
106    { NULL }
107};
108int (*OldDevnameHook)(char *cmd, char **argv, int doit) = NULL;
109static PPPoEConnection *conn = NULL;
110
111/**********************************************************************
112 * %FUNCTION: PPPOEInitDevice
113 * %ARGUMENTS:
114 * None
115 * %RETURNS:
116 *
117 * %DESCRIPTION:
118 * Initializes PPPoE device.
119 ***********************************************************************/
120static int
121PPPOEInitDevice(void)
122{
123    conn = malloc(sizeof(PPPoEConnection));
124    if (!conn) {
125	novm("PPPoE session data");
126    }
127    memset(conn, 0, sizeof(PPPoEConnection));
128    conn->ifName = devnam;
129    conn->discoverySocket = -1;
130    conn->sessionSocket = -1;
131    conn->printACNames = printACNames;
132    conn->discoveryTimeout = pppoe_padi_timeout;
133    conn->discoveryAttempts = pppoe_padi_attempts;
134    return 1;
135}
136
137/**********************************************************************
138 * %FUNCTION: PPPOEConnectDevice
139 * %ARGUMENTS:
140 * None
141 * %RETURNS:
142 * Non-negative if all goes well; -1 otherwise
143 * %DESCRIPTION:
144 * Connects PPPoE device.
145 ***********************************************************************/
146static int
147PPPOEConnectDevice(void)
148{
149    struct sockaddr_pppox sp;
150    struct ifreq ifr;
151    int s;
152
153    /* Open session socket before discovery phase, to avoid losing session */
154    /* packets sent by peer just after PADS packet (noted on some Cisco    */
155    /* server equipment).                                                  */
156    /* Opening this socket just before waitForPADS in the discovery()      */
157    /* function would be more appropriate, but it would mess-up the code   */
158    conn->sessionSocket = socket(AF_PPPOX, SOCK_STREAM, PX_PROTO_OE);
159    if (conn->sessionSocket < 0) {
160	error("Failed to create PPPoE socket: %m");
161	return -1;
162    }
163
164    /* Restore configuration */
165    lcp_allowoptions[0].mru = conn->mtu;
166    lcp_wantoptions[0].mru = conn->mru;
167
168    /* Update maximum MRU */
169    s = socket(AF_INET, SOCK_DGRAM, 0);
170    if (s < 0) {
171	error("Can't get MTU for %s: %m", conn->ifName);
172	goto errout;
173    }
174    strlcpy(ifr.ifr_name, conn->ifName, sizeof(ifr.ifr_name));
175    if (ioctl(s, SIOCGIFMTU, &ifr) < 0) {
176	error("Can't get MTU for %s: %m", conn->ifName);
177	close(s);
178	goto errout;
179    }
180    close(s);
181
182    if (lcp_allowoptions[0].mru > ifr.ifr_mtu - TOTAL_OVERHEAD)
183	lcp_allowoptions[0].mru = ifr.ifr_mtu - TOTAL_OVERHEAD;
184    if (lcp_wantoptions[0].mru > ifr.ifr_mtu - TOTAL_OVERHEAD)
185	lcp_wantoptions[0].mru = ifr.ifr_mtu - TOTAL_OVERHEAD;
186
187    if (pppoe_host_uniq) {
188	if (!parseHostUniq(pppoe_host_uniq, &conn->hostUniq))
189	    fatal("Illegal value for pppoe-host-uniq option");
190    } else {
191	/* if a custom host-uniq is not supplied, use our PID */
192	pid_t pid = getpid();
193	conn->hostUniq.type = htons(TAG_HOST_UNIQ);
194	conn->hostUniq.length = htons(sizeof(pid));
195	memcpy(conn->hostUniq.payload, &pid, sizeof(pid));
196    }
197
198    conn->acName = acName;
199    conn->serviceName = pppd_pppoe_service;
200    strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
201    if (existingSession) {
202	unsigned int mac[ETH_ALEN];
203	int i, ses;
204	if (sscanf(existingSession, "%d:%x:%x:%x:%x:%x:%x",
205		   &ses, &mac[0], &mac[1], &mac[2],
206		   &mac[3], &mac[4], &mac[5]) != 7) {
207	    fatal("Illegal value for pppoe-sess option");
208	}
209	conn->session = htons(ses);
210	for (i=0; i<ETH_ALEN; i++) {
211	    conn->peerEth[i] = (unsigned char) mac[i];
212	}
213    } else {
214	conn->discoverySocket =
215            openInterface(conn->ifName, Eth_PPPOE_Discovery, conn->myEth);
216	if (conn->discoverySocket < 0) {
217	    error("Failed to create PPPoE discovery socket: %m");
218	    goto errout;
219	}
220	discovery(conn);
221	if (conn->discoveryState != STATE_SESSION) {
222	    error("Unable to complete PPPoE Discovery");
223	    goto errout;
224	}
225    }
226
227    /* Set PPPoE session-number for further consumption */
228    ppp_session_number = ntohs(conn->session);
229
230    sp.sa_family = AF_PPPOX;
231    sp.sa_protocol = PX_PROTO_OE;
232    sp.sa_addr.pppoe.sid = conn->session;
233    memcpy(sp.sa_addr.pppoe.dev, conn->ifName, IFNAMSIZ);
234    memcpy(sp.sa_addr.pppoe.remote, conn->peerEth, ETH_ALEN);
235
236    /* Set remote_number for ServPoET */
237    sprintf(remote_number, "%02X:%02X:%02X:%02X:%02X:%02X",
238	    (unsigned) conn->peerEth[0],
239	    (unsigned) conn->peerEth[1],
240	    (unsigned) conn->peerEth[2],
241	    (unsigned) conn->peerEth[3],
242	    (unsigned) conn->peerEth[4],
243	    (unsigned) conn->peerEth[5]);
244
245    warn("Connected to %02X:%02X:%02X:%02X:%02X:%02X via interface %s",
246	 (unsigned) conn->peerEth[0],
247	 (unsigned) conn->peerEth[1],
248	 (unsigned) conn->peerEth[2],
249	 (unsigned) conn->peerEth[3],
250	 (unsigned) conn->peerEth[4],
251	 (unsigned) conn->peerEth[5],
252	 conn->ifName);
253
254    script_setenv("MACREMOTE", remote_number, 0);
255
256    if (connect(conn->sessionSocket, (struct sockaddr *) &sp,
257		sizeof(struct sockaddr_pppox)) < 0) {
258	error("Failed to connect PPPoE socket: %d %m", errno);
259	goto errout;
260    }
261
262    return conn->sessionSocket;
263
264 errout:
265    if (conn->discoverySocket >= 0) {
266	sendPADT(conn, NULL);
267	close(conn->discoverySocket);
268	conn->discoverySocket = -1;
269    }
270    close(conn->sessionSocket);
271    return -1;
272}
273
274static void
275PPPOERecvConfig(int mru,
276		u_int32_t asyncmap,
277		int pcomp,
278		int accomp)
279{
280#if 0 /* broken protocol, but no point harrassing the users I guess... */
281    if (mru > MAX_PPPOE_MTU)
282	warn("Couldn't increase MRU to %d", mru);
283#endif
284}
285
286/**********************************************************************
287 * %FUNCTION: PPPOEDisconnectDevice
288 * %ARGUMENTS:
289 * None
290 * %RETURNS:
291 * Nothing
292 * %DESCRIPTION:
293 * Disconnects PPPoE device
294 ***********************************************************************/
295static void
296PPPOEDisconnectDevice(void)
297{
298    struct sockaddr_pppox sp;
299
300    sp.sa_family = AF_PPPOX;
301    sp.sa_protocol = PX_PROTO_OE;
302    sp.sa_addr.pppoe.sid = 0;
303    memcpy(sp.sa_addr.pppoe.dev, conn->ifName, IFNAMSIZ);
304    memcpy(sp.sa_addr.pppoe.remote, conn->peerEth, ETH_ALEN);
305    if (connect(conn->sessionSocket, (struct sockaddr *) &sp,
306		sizeof(struct sockaddr_pppox)) < 0 && errno != EALREADY)
307	error("Failed to disconnect PPPoE socket: %d %m", errno);
308    close(conn->sessionSocket);
309    if (conn->discoverySocket >= 0) {
310        sendPADT(conn, NULL);
311	close(conn->discoverySocket);
312    }
313}
314
315static void
316PPPOEDeviceOptions(void)
317{
318    char buf[MAXPATHLEN];
319
320    strlcpy(buf, _PATH_ETHOPT, MAXPATHLEN);
321    strlcat(buf, devnam, MAXPATHLEN);
322    if (!options_from_file(buf, 0, 0, 1))
323	exit(EXIT_OPTION_ERROR);
324
325}
326
327struct 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 ***********************************************************************/
341static int
342PPPoEDevnameHook(char *cmd, char **argv, int doit)
343{
344    int r = 1;
345    int fd;
346    struct ifreq ifr;
347
348    /*
349     * Take any otherwise-unrecognized option as a possible device name,
350     * and test if it is the name of a network interface with a
351     * hardware address whose sa_family is ARPHRD_ETHER.
352     */
353    if (strlen(cmd) > 4 && !strncmp(cmd, "nic-", 4)) {
354	/* Strip off "nic-" */
355	cmd += 4;
356    }
357
358    /* Open a socket */
359    if ((fd = socket(PF_PACKET, SOCK_RAW, 0)) < 0) {
360	r = 0;
361    }
362
363    /* Try getting interface index */
364    if (r) {
365	strlcpy(ifr.ifr_name, cmd, sizeof(ifr.ifr_name));
366	if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
367	    r = 0;
368	} else {
369	    if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
370		r = 0;
371	    } else {
372		if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
373		    if (doit)
374			error("Interface %s not Ethernet", cmd);
375		    r = 0;
376		}
377	    }
378	}
379    }
380
381    /* Close socket */
382    close(fd);
383    if (r && doit) {
384	strlcpy(devnam, cmd, sizeof(devnam));
385	if (the_channel != &pppoe_channel) {
386
387	    the_channel = &pppoe_channel;
388	    modem = 0;
389
390	    PPPOEInitDevice();
391	}
392	return 1;
393    }
394
395    return r;
396}
397
398/**********************************************************************
399 * %FUNCTION: plugin_init
400 * %ARGUMENTS:
401 * None
402 * %RETURNS:
403 * Nothing
404 * %DESCRIPTION:
405 * Initializes hooks for pppd plugin
406 ***********************************************************************/
407void
408plugin_init(void)
409{
410    if (!ppp_available() && !new_style_driver) {
411	fatal("Linux kernel does not support PPPoE -- are you running 2.4.x?");
412    }
413
414    add_options(Options);
415
416    info("PPPoE plugin from pppd %s", VERSION);
417}
418
419void pppoe_check_options(void)
420{
421    unsigned int mac[6];
422    int i;
423
424    if (pppoe_reqd_mac != NULL) {
425	if (sscanf(pppoe_reqd_mac, "%x:%x:%x:%x:%x:%x",
426		   &mac[0], &mac[1], &mac[2], &mac[3],
427		   &mac[4], &mac[5]) != 6) {
428	    option_error("cannot parse pppoe-mac option value");
429	    exit(EXIT_OPTION_ERROR);
430	}
431	for (i = 0; i < 6; ++i)
432	    conn->req_peer_mac[i] = mac[i];
433	conn->req_peer = 1;
434    }
435
436    lcp_allowoptions[0].neg_accompression = 0;
437    lcp_wantoptions[0].neg_accompression = 0;
438
439    lcp_allowoptions[0].neg_asyncmap = 0;
440    lcp_wantoptions[0].neg_asyncmap = 0;
441
442    lcp_allowoptions[0].neg_pcompression = 0;
443    lcp_wantoptions[0].neg_pcompression = 0;
444
445    if (lcp_allowoptions[0].mru > MAX_PPPOE_MTU)
446	lcp_allowoptions[0].mru = MAX_PPPOE_MTU;
447    if (lcp_wantoptions[0].mru > MAX_PPPOE_MTU)
448	lcp_wantoptions[0].mru = MAX_PPPOE_MTU;
449
450    /* Save configuration */
451    conn->mtu = lcp_allowoptions[0].mru;
452    conn->mru = lcp_wantoptions[0].mru;
453
454    ccp_allowoptions[0].deflate = 0;
455    ccp_wantoptions[0].deflate = 0;
456
457    ipcp_allowoptions[0].neg_vj = 0;
458    ipcp_wantoptions[0].neg_vj = 0;
459
460    ccp_allowoptions[0].bsd_compress = 0;
461    ccp_wantoptions[0].bsd_compress = 0;
462}
463
464struct channel pppoe_channel = {
465    .options = Options,
466    .process_extra_options = &PPPOEDeviceOptions,
467    .check_options = pppoe_check_options,
468    .connect = &PPPOEConnectDevice,
469    .disconnect = &PPPOEDisconnectDevice,
470    .establish_ppp = &generic_establish_ppp,
471    .disestablish_ppp = &generic_disestablish_ppp,
472    .send_config = NULL,
473    .recv_config = &PPPOERecvConfig,
474    .close = NULL,
475    .cleanup = NULL
476};
477