BadVPN – Rev 1
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/*
* multilink.c - support routines for multilink.
*
* Copyright (c) 2000-2002 Paul Mackerras. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 3. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <paulus@samba.org>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT && defined(HAVE_MULTILINK) /* don't build if not configured for use in lwipopts.h */
/* Multilink support
*
* Multilink uses Samba TDB (Trivial Database Library), which
* we cannot port, because it needs a filesystem.
*
* We have to choose between doing a memory-shared TDB-clone,
* or dropping multilink support at all.
*/
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <netdb.h>
#include <errno.h>
#include <signal.h>
#include <netinet/in.h>
#include <unistd.h>
#include "netif/ppp/ppp_impl.h"
#include "netif/ppp/fsm.h"
#include "netif/ppp/lcp.h"
#include "netif/ppp/tdb.h"
bool endpoint_specified; /* user gave explicit endpoint discriminator */
char *bundle_id; /* identifier for our bundle */
char *blinks_id; /* key for the list of links */
bool doing_multilink; /* multilink was enabled and agreed to */
bool multilink_master; /* we own the multilink bundle */
extern TDB_CONTEXT *pppdb;
extern char db_key[];
static void make_bundle_links (int append);
static void remove_bundle_link (void);
static void iterate_bundle_links (void (*func) (char *));
static int get_default_epdisc (struct epdisc *);
static int parse_num (char *str, const char *key, int *valp);
static int owns_unit (TDB_DATA pid, int unit);
#define set_ip_epdisc(ep, addr) do { \
ep->length = 4; \
ep->value[0] = addr >> 24; \
ep->value[1] = addr >> 16; \
ep->value[2] = addr >> 8; \
ep->value[3] = addr; \
} while (0)
#define LOCAL_IP_ADDR(addr) \
(((addr) & 0xff000000) == 0x0a000000 /* 10.x.x.x */ \
|| ((addr) & 0xfff00000) == 0xac100000 /* 172.16.x.x */ \
|| ((addr) & 0xffff0000) == 0xc0a80000) /* 192.168.x.x */
#define process_exists(n) (kill((n), 0) == 0 || errno != ESRCH)
void
mp_check_options()
{
lcp_options *wo = &lcp_wantoptions[0];
lcp_options *ao = &lcp_allowoptions[0];
doing_multilink = 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);
}
}
/*
* 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];
lcp_options *ao = &lcp_allowoptions[0];
int unit, pppd_pid;
int l, mtu;
char *p;
TDB_DATA key, pid, rec;
if (doing_multilink) {
/* have previously joined a bundle */
if (!go->neg_mrru || !ho->neg_mrru) {
notice("oops, didn't get multilink on renegotiation");
lcp_close(pcb, "multilink required");
return 0;
}
/* XXX should check the peer_authname and ho->endpoint
are the same as previously */
return 0;
}
if (!go->neg_mrru || !ho->neg_mrru) {
/* not doing multilink */
if (go->neg_mrru)
notice("oops, multilink negotiated only for receive");
mtu = ho->neg_mru? ho->mru: PPP_MRU;
if (mtu > ao->mru)
mtu = ao->mru;
if (demand) {
/* already have a bundle */
cfg_bundle(0, 0, 0, 0);
netif_set_mtu(pcb, mtu);
return 0;
}
make_new_bundle(0, 0, 0, 0);
set_ifunit(1);
netif_set_mtu(pcb, mtu);
return 0;
}
doing_multilink = 1;
/*
* 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.
*/
l = 4 * strlen(peer_authname) + 10;
if (ho->neg_endpoint)
l += 3 * ho->endpoint.length + 8;
if (bundle_name)
l += 3 * strlen(bundle_name) + 2;
bundle_id = malloc(l);
if (bundle_id == 0)
novm("bundle identifier");
p = bundle_id;
p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
if (ho->neg_endpoint || bundle_name)
*p++ = '/';
if (ho->neg_endpoint)
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);
/* Make the key for the list of links belonging to the bundle */
l = p - bundle_id;
blinks_id = malloc(l + 7);
if (blinks_id == NULL)
novm("bundle links key");
slprintf(blinks_id, l + 7, "BUNDLE_LINKS=%s", bundle_id + 7);
/*
* For demand mode, we only need to configure the bundle
* and attach the link.
*/
mtu = LWIP_MIN(ho->mrru, ao->mru);
if (demand) {
cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
netif_set_mtu(pcb, mtu);
script_setenv("BUNDLE", bundle_id + 7, 1);
return 0;
}
/*
* Check if the bundle ID is already in the database.
*/
unit = -1;
lock_db();
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 && rec.dsize > 0) {
/* make sure the string is null-terminated */
rec.dptr[rec.dsize-1] = 0;
/* 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);
make_bundle_links(1);
unlock_db();
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);
netif_set_mtu(pcb, mtu);
script_setenv("BUNDLE", bundle_id + 7, 1);
make_bundle_links(pcb);
unlock_db();
info("New bundle %s created", ifname);
multilink_master = 1;
return 0;
}
void mp_exit_bundle()
{
lock_db();
remove_bundle_link();
unlock_db();
}
static void sendhup(char *str)
{
int pid;
if (parse_num(str, "PPPD_PID=", &pid) && pid != getpid()) {
if (debug)
dbglog("sending SIGHUP to process %d", pid);
kill(pid, SIGHUP);
}
}
void mp_bundle_terminated()
{
TDB_DATA key;
bundle_terminating = 1;
upper_layers_down(pcb);
notice("Connection terminated.");
#if PPP_STATS_SUPPORT
print_link_stats();
#endif /* PPP_STATS_SUPPORT */
if (!demand) {
remove_pidfiles();
script_unsetenv("IFNAME");
}
lock_db();
destroy_bundle();
iterate_bundle_links(sendhup);
key.dptr = blinks_id;
key.dsize = strlen(blinks_id);
tdb_delete(pppdb, key);
unlock_db();
new_phase(PPP_PHASE_DEAD);
doing_multilink = 0;
multilink_master = 0;
}
static void make_bundle_links(int append)
{
TDB_DATA key, rec;
char *p;
char entry[32];
int l;
key.dptr = blinks_id;
key.dsize = strlen(blinks_id);
slprintf(entry, sizeof(entry), "%s;", db_key);
p = entry;
if (append) {
rec = tdb_fetch(pppdb, key);
if (rec.dptr != NULL && rec.dsize > 0) {
rec.dptr[rec.dsize-1] = 0;
if (strstr(rec.dptr, db_key) != NULL) {
/* already in there? strange */
warn("link entry already exists in tdb");
return;
}
l = rec.dsize + strlen(entry);
p = malloc(l);
if (p == NULL)
novm("bundle link list");
slprintf(p, l, "%s%s", rec.dptr, entry);
} else {
warn("bundle link list not found");
}
if (rec.dptr != NULL)
free(rec.dptr);
}
rec.dptr = p;
rec.dsize = strlen(p) + 1;
if (tdb_store(pppdb, key, rec, TDB_REPLACE))
error("couldn't %s bundle link list",
append? "update": "create");
if (p != entry)
free(p);
}
static void remove_bundle_link()
{
TDB_DATA key, rec;
char entry[32];
char *p, *q;
int l;
key.dptr = blinks_id;
key.dsize = strlen(blinks_id);
slprintf(entry, sizeof(entry), "%s;", db_key);
rec = tdb_fetch(pppdb, key);
if (rec.dptr == NULL || rec.dsize <= 0) {
if (rec.dptr != NULL)
free(rec.dptr);
return;
}
rec.dptr[rec.dsize-1] = 0;
p = strstr(rec.dptr, entry);
if (p != NULL) {
q = p + strlen(entry);
l = strlen(q) + 1;
memmove(p, q, l);
rec.dsize = p - rec.dptr + l;
if (tdb_store(pppdb, key, rec, TDB_REPLACE))
error("couldn't update bundle link list (removal)");
}
free(rec.dptr);
}
static void iterate_bundle_links(void (*func)(char *))
{
TDB_DATA key, rec, pp;
char *p, *q;
key.dptr = blinks_id;
key.dsize = strlen(blinks_id);
rec = tdb_fetch(pppdb, key);
if (rec.dptr == NULL || rec.dsize <= 0) {
error("bundle link list not found (iterating list)");
if (rec.dptr != NULL)
free(rec.dptr);
return;
}
p = rec.dptr;
p[rec.dsize-1] = 0;
while ((q = strchr(p, ';')) != NULL) {
*q = 0;
key.dptr = p;
key.dsize = q - p;
pp = tdb_fetch(pppdb, key);
if (pp.dptr != NULL && pp.dsize > 0) {
pp.dptr[pp.dsize-1] = 0;
func(pp.dptr);
}
if (pp.dptr != NULL)
free(pp.dptr);
p = q + 1;
}
free(rec.dptr);
}
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;
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;
{
char *p;
struct hostent *hp;
u32_t addr;
/* First try for an ethernet MAC address */
p = get_first_ethernet();
if (p != 0 && get_if_hwaddr(ep->value, p) >= 0) {
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 = *(u32_t *)hp->h_addr;
if (!bad_ip_adrs(addr)) {
addr = lwip_ntohl(addr);
if (!LOCAL_IP_ADDR(addr)) {
ep->class = EPD_IP;
set_ip_epdisc(ep, addr);
return 1;
}
}
}
return 0;
}
/*
* 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) {
u32_t addr;
GETLONG(addr, p);
slprintf(str, sizeof(str), "IP:%I", lwip_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)
return 0; /* can't parse class number */
str = endp;
}
ep->class = i;
if (*str == 0) {
ep->length = 0;
return 1;
}
if (*str != ':' && *str != '.')
return 0;
++str;
if (i == EPD_IP) {
u32_t addr;
i = parse_dotted_ip(str, &addr);
if (i == 0 || str[i] != 0)
return 0;
set_ip_epdisc(ep, addr);
return 1;
}
if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) {
ep->length = 6;
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)
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 || (ep->class == EPD_MAC && l != 6))
return 0;
ep->length = l;
return 1;
}
#endif /* PPP_SUPPORT && HAVE_MULTILINK */