multilink.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* multilink.c - support routines for multilink.
*
* Copyright (c) 2000-2001 by Sun Microsystems, Inc.
* All rights reserved.
*
* Copyright (c) 2000 Paul Mackerras.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms. The name of the author may not be
* used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#define RCSID "$Id: $"
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <netdb.h>
#include <errno.h>
#include <signal.h>
#include <netinet/in.h>
#include "pppd.h"
#include "fsm.h"
#include "lcp.h"
#ifdef HAVE_MULTILINK
#include "tdb.h"
#endif
#if !defined(lint) && !defined(_lint)
static const char rcsid[] = RCSID;
#endif
#define set_ip_epdisc(ep, addr) ( \
ep->length = 4, \
ep->value[0] = addr >> 24, \
ep->value[1] = addr >> 16, \
ep->value[2] = addr >> 8, \
ep->value[3] = addr \
)
#ifdef HAVE_MULTILINK
bool endpoint_specified; /* user gave explicit endpoint discriminator */
char *bundle_id; /* identifier for our bundle */
static int get_default_epdisc __P((struct epdisc *));
static int parse_num __P((char *str, const char *key, int *valp));
static int owns_unit __P((TDB_DATA pid, int unit));
#define process_exists(n) (kill(0, (n)) == 0 || errno != ESRCH)
void
mp_check_options()
{
lcp_options *wo = &lcp_wantoptions[0];
lcp_options *ao = &lcp_allowoptions[0];
if (!multilink)
return;
/* if we're doing multilink, we have to negotiate MRRU */
if (!wo->neg_mrru) {
/* mrru not specified, default to mru */
wo->mrru = wo->mru;
wo->neg_mrru = 1;
}
ao->mrru = ao->mru;
ao->neg_mrru = 1;
if (!wo->neg_endpoint && !noendpoint) {
/* get a default endpoint value */
wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
if (wo->neg_endpoint)
dbglog("using default endpoint %s",
epdisc_to_str(&wo->endpoint));
}
}
/*
* Make a new bundle or join us to an existing bundle
* if we are doing multilink.
*/
int
mp_join_bundle()
{
lcp_options *go = &lcp_gotoptions[0];
lcp_options *ho = &lcp_hisoptions[0];
int unit, pppd_pid;
int l;
char *p;
TDB_DATA key, pid, rec;
if (!go->neg_mrru || !ho->neg_mrru) {
/* not doing multilink */
if (go->neg_mrru)
notice("oops, multilink negotiated only for receive");
multilink = 0;
if (demand) {
/* already have a bundle */
cfg_bundle(0, 0, 0, 0);
return 0;
}
make_new_bundle(0, 0, 0, 0);
set_ifunit(1);
return 0;
}
/*
* Find the appropriate bundle or join a new one.
* First we make up a name for the bundle.
* The length estimate is worst-case assuming every
* character has to be quoted.
*
* Note - RFC 1990 requires that an unnegotiated endpoint
* discriminator value be equivalent to negotiating with class
* zero. Do not test ho->neg_endpoint here.
*/
l = 4 * strlen(peer_authname) + 10;
l += 3 * ho->endpoint.length + 8;
if (bundle_name)
l += 3 * strlen(bundle_name) + 2;
bundle_id = malloc(l);
if (bundle_id == NULL)
novm("bundle identifier");
p = bundle_id;
p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
*p++ = '/';
p += slprintf(p, bundle_id+l-p, "%s", epdisc_to_str(&ho->endpoint));
if (bundle_name)
p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
dbglog("bundle_id = %s", bundle_id+7);
/*
* For demand mode, we only need to configure the bundle
* and attach the link.
*/
if (demand) {
cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
script_setenv("BUNDLE", bundle_id + 7, 1);
return 0;
}
/*
* Check if the bundle ID is already in the database.
*/
unit = -1;
tdb_writelock(pppdb);
key.dptr = bundle_id;
key.dsize = p - bundle_id;
pid = tdb_fetch(pppdb, key);
if (pid.dptr != NULL) {
/* bundle ID exists, see if the pppd record exists */
rec = tdb_fetch(pppdb, pid);
if (rec.dptr != NULL) {
/* it does, parse the interface number */
parse_num(rec.dptr, "IFNAME=ppp", &unit);
/* check the pid value */
if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
|| !process_exists(pppd_pid)
|| !owns_unit(pid, unit))
unit = -1;
free(rec.dptr);
}
free(pid.dptr);
}
if (unit >= 0) {
/* attach to existing unit */
if (bundle_attach(unit)) {
set_ifunit(0);
script_setenv("BUNDLE", bundle_id + 7, 0);
tdb_writeunlock(pppdb);
info("Link attached to %s", ifname);
return 1;
}
/* attach failed because bundle doesn't exist */
}
/* we have to make a new bundle */
make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
set_ifunit(1);
script_setenv("BUNDLE", bundle_id + 7, 1);
tdb_writeunlock(pppdb);
info("New bundle %s created", ifname);
return 0;
}
static int
parse_num(str, key, valp)
char *str;
const char *key;
int *valp;
{
char *p, *endp;
int i;
p = strstr(str, key);
if (p != 0) {
p += strlen(key);
i = strtol(p, &endp, 10);
if (endp != p && (*endp == 0 || *endp == ';')) {
*valp = i;
return 1;
}
}
return 0;
}
/*
* Check whether the pppd identified by `key' still owns ppp unit `unit'.
*/
static int
owns_unit(key, unit)
TDB_DATA key;
int unit;
{
char ifkey[32];
TDB_DATA kd, vd;
int ret = 0;
(void) slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
kd.dptr = ifkey;
kd.dsize = strlen(ifkey);
vd = tdb_fetch(pppdb, kd);
if (vd.dptr != NULL) {
ret = vd.dsize == key.dsize
&& memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
free(vd.dptr);
}
return ret;
}
static int
get_default_epdisc(ep)
struct epdisc *ep;
{
struct hostent *hp;
u_int32_t addr;
if (get_first_hwaddr(ep->value, sizeof(ep->value))) {
ep->class = EPD_MAC;
ep->length = 6;
return 1;
}
/* see if our hostname corresponds to a reasonable IP address */
hp = gethostbyname(hostname);
if (hp != NULL) {
addr = *(u_int32_t *)hp->h_addr;
if (!bad_ip_adrs(addr)) {
addr = ntohl(addr);
if (!LOCAL_IP_ADDR(addr)) {
ep->class = EPD_IP;
set_ip_epdisc(ep, addr);
return 1;
}
}
}
return 0;
}
#endif /* HAVE_MULTILINK */
/*
* epdisc_to_str - make a printable string from an endpoint discriminator.
*/
static char *endp_class_names[] = {
"null", "local", "IP", "MAC", "magic", "phone"
};
char *
epdisc_to_str(ep)
struct epdisc *ep;
{
static char str[MAX_ENDP_LEN*3+8];
u_char *p = ep->value;
int i, mask = 0;
char *q, c, c2;
if (ep->class == EPD_NULL && ep->length == 0)
return "null";
if (ep->class == EPD_IP && ep->length == 4) {
u_int32_t addr;
GETLONG(addr, p);
(void) slprintf(str, sizeof(str), "IP:%I", htonl(addr));
return str;
}
c = ':';
c2 = '.';
if (ep->class == EPD_MAC && ep->length == 6)
c2 = ':';
else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
mask = 3;
q = str;
if (ep->class <= EPD_PHONENUM)
q += slprintf(q, sizeof(str)-1, "%s",
endp_class_names[ep->class]);
else
q += slprintf(q, sizeof(str)-1, "%d", ep->class);
c = ':';
for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
if ((i & mask) == 0) {
*q++ = c;
c = c2;
}
q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
}
return str;
}
static int hexc_val(int c)
{
if (c >= 'a')
return c - 'a' + 10;
if (c >= 'A')
return c - 'A' + 10;
return c - '0';
}
int
str_to_epdisc(ep, str)
struct epdisc *ep;
char *str;
{
int i, l;
char *p, *endp;
for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
int sl = strlen(endp_class_names[i]);
if (strncasecmp(str, endp_class_names[i], sl) == 0) {
str += sl;
break;
}
}
if (i > EPD_PHONENUM) {
/* not a class name, try a decimal class number */
i = strtol(str, &endp, 10);
if (endp == str) {
option_error("cannot parse endpoint class in \"%s\"",
str);
return 0; /* can't parse class number */
}
str = endp;
}
ep->class = i;
if (*str == 0) {
ep->length = 0;
return 1;
}
if (*str != ':' && *str != '.') {
option_error("invalid class/value separator '%c'", *str);
return 0;
}
++str;
if (i == EPD_IP) {
u_int32_t addr;
i = parse_dotted_ip(str, &addr);
if (i == 0 || str[i] != 0)
return 0;
set_ip_epdisc(ep, addr);
dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
return 1;
}
if (i == EPD_MAC &&
get_if_hwaddr(ep->value, sizeof(ep->value), str) >= 0) {
ep->length = 6;
dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
return 1;
}
p = str;
for (l = 0; l < MAX_ENDP_LEN; ++l) {
if (*str == 0)
break;
if (p <= str)
for (p = str; isxdigit(*p); ++p)
;
i = p - str;
if (i == 0) {
option_error("no valid hex digits in \"%s\"", str);
return 0;
}
ep->value[l] = hexc_val(*str++);
if ((i & 1) == 0)
ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
if (*str == ':' || *str == '.')
++str;
}
if (*str != 0) {
option_error("too many bytes in value; max is %d",
MAX_ENDP_LEN);
return 0;
}
if (ep->class == EPD_MAC && l != 6) {
option_error("bad endpoint; MAC address must have 6 bytes");
return 0;
}
ep->length = l;
dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
return 1;
}