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      1 /* pppoatm.c - pppd plugin to implement PPPoATM protocol.
      2  *
      3  * Copyright 2000 Mitchell Blank Jr.
      4  * Based in part on work from Jens Axboe and Paul Mackerras.
      5  * Updated to ppp-2.4.1 by Bernhard Kaindl
      6  *
      7  * Updated to ppp-2.4.2 by David Woodhouse 2004.
      8  *  - disconnect method added
      9  *  - remove_options() abuse removed.
     10  *
     11  *  This program is free software; you can redistribute it and/or
     12  *  modify it under the terms of the GNU General Public License
     13  *  as published by the Free Software Foundation; either version
     14  *  2 of the License, or (at your option) any later version.
     15  */
     16 #include <unistd.h>
     17 #include <string.h>
     18 #include <stdlib.h>
     19 #include "pppd.h"
     20 #include "pathnames.h"
     21 #include "fsm.h" /* Needed for lcp.h to include cleanly */
     22 #include "lcp.h"
     23 #include <atm.h>
     24 #include <linux/atmdev.h>
     25 #include <linux/atmppp.h>
     26 #include <sys/stat.h>
     27 #include <net/if.h>
     28 #include <sys/ioctl.h>
     29 
     30 const char pppd_version[] = VERSION;
     31 
     32 static struct sockaddr_atmpvc pvcaddr;
     33 static char *qosstr = NULL;
     34 static bool llc_encaps = 0;
     35 static bool vc_encaps = 0;
     36 static int device_got_set = 0;
     37 static int pppoatm_max_mtu, pppoatm_max_mru;
     38 static int setdevname_pppoatm(const char *cp, const char **argv, int doit);
     39 struct channel pppoa_channel;
     40 static int pppoa_fd = -1;
     41 
     42 static option_t pppoa_options[] = {
     43 	{ "device name", o_wild, (void *) &setdevname_pppoatm,
     44 	  "ATM service provider IDs: VPI.VCI",
     45 	  OPT_DEVNAM | OPT_PRIVFIX | OPT_NOARG  | OPT_A2STRVAL | OPT_STATIC,
     46 	  devnam},
     47 	{ "llc-encaps", o_bool, &llc_encaps,
     48 	  "use LLC encapsulation for PPPoATM", 1},
     49 	{ "vc-encaps", o_bool, &vc_encaps,
     50 	  "use VC multiplexing for PPPoATM (default)", 1},
     51 	{ "qos", o_string, &qosstr,
     52 	  "set QoS for PPPoATM connection", 1},
     53 	{ NULL }
     54 };
     55 
     56 /* returns:
     57  *  -1 if there's a problem with setting the device
     58  *   0 if we can't parse "cp" as a valid name of a device
     59  *   1 if "cp" is a reasonable thing to name a device
     60  * Note that we don't actually open the device at this point
     61  * We do need to fill in:
     62  *   devnam: a string representation of the device
     63  *   devstat: a stat structure of the device.  In this case
     64  *     we're not opening a device, so we just make sure
     65  *     to set up S_ISCHR(devstat.st_mode) != 1, so we
     66  *     don't get confused that we're on stdin.
     67  */
     68 int (*old_setdevname_hook)(const char* cp) = NULL;
     69 static int setdevname_pppoatm(const char *cp, const char **argv, int doit)
     70 {
     71 	struct sockaddr_atmpvc addr;
     72 	extern struct stat devstat;
     73 	if (device_got_set)
     74 		return 0;
     75 	//info("PPPoATM setdevname_pppoatm: '%s'", cp);
     76 	memset(&addr, 0, sizeof addr);
     77 	if (text2atm(cp, (struct sockaddr *) &addr, sizeof(addr),
     78 	    T2A_PVC | T2A_NAME) < 0) {
     79                if(doit)
     80                    info("atm does not recognize: %s", cp);
     81 		return 0;
     82            }
     83 	if (!doit) return 1;
     84 	//if (!dev_set_ok()) return -1;
     85 	memcpy(&pvcaddr, &addr, sizeof pvcaddr);
     86 	strlcpy(devnam, cp, sizeof devnam);
     87 	devstat.st_mode = S_IFSOCK;
     88 	if (the_channel != &pppoa_channel) {
     89 		the_channel = &pppoa_channel;
     90 		lcp_wantoptions[0].neg_accompression = 0;
     91 		lcp_allowoptions[0].neg_accompression = 0;
     92 		lcp_wantoptions[0].neg_asyncmap = 0;
     93 		lcp_allowoptions[0].neg_asyncmap = 0;
     94 		lcp_wantoptions[0].neg_pcompression = 0;
     95 	}
     96 	info("PPPoATM setdevname_pppoatm - SUCCESS:%s", cp);
     97 	device_got_set = 1;
     98 	return 1;
     99 }
    100 
    101 #define pppoatm_overhead() (llc_encaps ? 6 : 2)
    102 
    103 static void no_device_given_pppoatm(void)
    104 {
    105 	fatal("No vpi.vci specified");
    106 }
    107 
    108 static void set_line_discipline_pppoatm(int fd)
    109 {
    110 	struct atm_backend_ppp be;
    111 	be.backend_num = ATM_BACKEND_PPP;
    112 	if (!llc_encaps)
    113 		be.encaps = PPPOATM_ENCAPS_VC;
    114 	else if (!vc_encaps)
    115 		be.encaps = PPPOATM_ENCAPS_LLC;
    116 	else
    117 		be.encaps = PPPOATM_ENCAPS_AUTODETECT;
    118 	if (ioctl(fd, ATM_SETBACKEND, &be) < 0)
    119 		fatal("ioctl(ATM_SETBACKEND): %m");
    120 }
    121 
    122 #if 0
    123 static void reset_line_discipline_pppoatm(int fd)
    124 {
    125 	atm_backend_t be = ATM_BACKEND_RAW;
    126 	/* 2.4 doesn't support this yet */
    127 	(void) ioctl(fd, ATM_SETBACKEND, &be);
    128 }
    129 #endif
    130 
    131 static int connect_pppoatm(void)
    132 {
    133 	int fd;
    134 	struct atm_qos qos;
    135 
    136 	/* XXX: This won't work on Android */
    137 	system ("/sbin/modprobe pppoatm");
    138 
    139 	if (!device_got_set)
    140 		no_device_given_pppoatm();
    141 	fd = socket(AF_ATMPVC, SOCK_DGRAM, 0);
    142 	if (fd < 0)
    143 		fatal("failed to create socket: %m");
    144 	memset(&qos, 0, sizeof qos);
    145 	qos.txtp.traffic_class = qos.rxtp.traffic_class = ATM_UBR;
    146 	/* TODO: support simplified QoS setting */
    147 	if (qosstr != NULL)
    148 		if (text2qos(qosstr, &qos, 0))
    149 			fatal("Can't parse QoS: \"%s\"");
    150 	qos.txtp.max_sdu = lcp_allowoptions[0].mru + pppoatm_overhead();
    151 	qos.rxtp.max_sdu = lcp_wantoptions[0].mru + pppoatm_overhead();
    152 	qos.aal = ATM_AAL5;
    153 	if (setsockopt(fd, SOL_ATM, SO_ATMQOS, &qos, sizeof(qos)) < 0)
    154 		fatal("setsockopt(SO_ATMQOS): %m");
    155 	/* TODO: accept on SVCs... */
    156 	if (connect(fd, (struct sockaddr *) &pvcaddr,
    157 	    sizeof(struct sockaddr_atmpvc)))
    158 		fatal("connect(%s): %m", devnam);
    159 	pppoatm_max_mtu = lcp_allowoptions[0].mru;
    160 	pppoatm_max_mru = lcp_wantoptions[0].mru;
    161 	set_line_discipline_pppoatm(fd);
    162 	strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
    163 	pppoa_fd = fd;
    164 	return fd;
    165 }
    166 
    167 static void disconnect_pppoatm(void)
    168 {
    169 	close(pppoa_fd);
    170 }
    171 
    172 static void send_config_pppoa(int mtu,
    173 			      u_int32_t asyncmap,
    174 			      int pcomp,
    175 			      int accomp)
    176 {
    177 	int sock;
    178 	struct ifreq ifr;
    179 	if (mtu > pppoatm_max_mtu)
    180 		error("Couldn't increase MTU to %d", mtu);
    181 	sock = socket(AF_INET, SOCK_DGRAM, 0);
    182 	if (sock < 0)
    183 		fatal("Couldn't create IP socket: %m");
    184 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
    185 	ifr.ifr_mtu = mtu;
    186 	if (ioctl(sock, SIOCSIFMTU, (caddr_t) &ifr) < 0)
    187 		fatal("ioctl(SIOCSIFMTU): %m");
    188 	(void) close (sock);
    189 }
    190 
    191 static void recv_config_pppoa(int mru,
    192 			      u_int32_t asyncmap,
    193 			      int pcomp,
    194 			      int accomp)
    195 {
    196 	if (mru > pppoatm_max_mru)
    197 		error("Couldn't increase MRU to %d", mru);
    198 }
    199 
    200 void plugin_init(void)
    201 {
    202 #if defined(__linux__)
    203 	extern int new_style_driver;	/* From sys-linux.c */
    204 	if (!ppp_available() && !new_style_driver)
    205 		fatal("Kernel doesn't support ppp_generic - "
    206 		    "needed for PPPoATM");
    207 #else
    208 	fatal("No PPPoATM support on this OS");
    209 #endif
    210 	info("PPPoATM plugin_init");
    211 	add_options(pppoa_options);
    212 }
    213 struct channel pppoa_channel = {
    214     options: pppoa_options,
    215     process_extra_options: NULL,
    216     check_options: NULL,
    217     connect: &connect_pppoatm,
    218     disconnect: &disconnect_pppoatm,
    219     establish_ppp: &generic_establish_ppp,
    220     disestablish_ppp: &generic_disestablish_ppp,
    221     send_config: &send_config_pppoa,
    222     recv_config: &recv_config_pppoa,
    223     close: NULL,
    224     cleanup: NULL
    225 };
    226