/* site.c - manage communication with a remote network site */
-#include <stdio.h>
-#include <sys/mman.h>
+/* The 'site' code doesn't know anything about the structure of the
+ packets it's transmitting. In fact, under the new netlink
+ configuration scheme it doesn't need to know anything at all about
+ IP addresses, except how to contact its peer. This means it could
+ potentially be used to tunnel other protocols too (IPv6, IPX, plain
+ old Ethernet frames) if appropriate netlink code can be written
+ (and that ought not to be too hard, eg. using the TUN/TAP device to
+ pretend to be an Ethernet interface). */
#include "secnet.h"
+#include <stdio.h>
+#include <string.h>
+/* MBM asserts the next one is needed for compilation under BSD. */
+#include <sys/socket.h>
+
+#include <sys/mman.h>
#include "util.h"
#include "unaligned.h"
#define SETUP_BUFFER_LEN 2048
-#define DEFAULT_KEY_LIFETIME 3600000
+#define DEFAULT_KEY_LIFETIME 3600000 /* One hour */
+#define DEFAULT_KEY_RENEGOTIATE_GAP 300000 /* Five minutes */
#define DEFAULT_SETUP_RETRIES 5
#define DEFAULT_SETUP_TIMEOUT 1000
-#define DEFAULT_WAIT_TIME 10000
+#define DEFAULT_WAIT_TIME 20000
/* Each site can be in one of several possible states. */
static string_t state_name(uint32_t state)
{
switch (state) {
- case 0: return "SITE_STOP";
- case 1: return "SITE_RUN";
- case 2: return "SITE_RESOLVE";
- case 3: return "SITE_SENTMSG1";
- case 4: return "SITE_SENTMSG2";
- case 5: return "SITE_SENTMSG3";
- case 6: return "SITE_SENTMSG4";
- case 7: return "SITE_SENTMSG5";
- case 8: return "SITE_WAIT";
+ case 0: return "STOP";
+ case 1: return "RUN";
+ case 2: return "RESOLVE";
+ case 3: return "SENTMSG1";
+ case 4: return "SENTMSG2";
+ case 5: return "SENTMSG3";
+ case 6: return "SENTMSG4";
+ case 7: return "SENTMSG5";
+ case 8: return "WAIT";
default: return "*bad state*";
}
}
#define LOG_SETUP_TIMEOUT 0x00000004
#define LOG_ACTIVATE_KEY 0x00000008
#define LOG_TIMEOUT_KEY 0x00000010
-#define LOG_SEC 0x00000020
+#define LOG_SEC 0x00000020
#define LOG_STATE 0x00000040
#define LOG_DROP 0x00000080
#define LOG_DUMP 0x00000100
#define LOG_ERROR 0x00000400
+static struct flagstr log_event_table[]={
+ { "unexpected", LOG_UNEXPECTED },
+ { "setup-init", LOG_SETUP_INIT },
+ { "setup-timeout", LOG_SETUP_TIMEOUT },
+ { "activate-key", LOG_ACTIVATE_KEY },
+ { "timeout-key", LOG_TIMEOUT_KEY },
+ { "security", LOG_SEC },
+ { "state-change", LOG_STATE },
+ { "packet-drop", LOG_DROP },
+ { "dump-packets", LOG_DUMP },
+ { "errors", LOG_ERROR },
+ { "all", 0xffffffff },
+ { NULL, 0 }
+};
+
struct site {
closure_t cl;
struct site_if ops;
struct log_if *log;
struct random_if *random;
struct rsaprivkey_if *privkey;
- struct subnet_list remotenets;
struct rsapubkey_if *pubkey;
struct transform_if *transform;
struct dh_if *dh;
struct hash_if *hash;
- void *netlink_cid;
uint32_t setup_retries; /* How many times to send setup packets */
uint32_t setup_timeout; /* Initial timeout for setup packets */
uint32_t wait_timeout; /* How long to wait if setup unsuccessful */
uint32_t key_lifetime; /* How long a key lasts once set up */
+ uint32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
+ after this time, initiate a new
+ key exchange */
+
+ bool_t keepalive; /* Always keep the tunnel up */
uint8_t *setupsig; /* Expected signature of incoming MSG1 packets */
uint32_t setupsiglen; /* Allows us to discard packets quickly if
{
va_list ap;
uint8_t buf[240];
+ uint32_t class;
va_start(ap,msg);
if (event&st->log_events) {
+ switch(event) {
+ case LOG_UNEXPECTED: class=M_INFO; break;
+ case LOG_SETUP_INIT: class=M_INFO; break;
+ case LOG_SETUP_TIMEOUT: class=M_NOTICE; break;
+ case LOG_ACTIVATE_KEY: class=M_INFO; break;
+ case LOG_TIMEOUT_KEY: class=M_INFO; break;
+ case LOG_SEC: class=M_SECURITY; break;
+ case LOG_STATE: class=M_DEBUG; break;
+ case LOG_DROP: class=M_DEBUG; break;
+ case LOG_DUMP: class=M_DEBUG; break;
+ case LOG_ERROR: class=M_ERR; break;
+ default: class=M_ERR; break;
+ }
+
vsnprintf(buf,240,msg,ap);
- st->log->log(st->log->st,0,"%s: %s",st->tunname,buf);
+ st->log->log(st->log->st,class,"%s: %s",st->tunname,buf);
}
va_end(ap);
}
+static void set_link_quality(struct site *st);
+static void delete_key(struct site *st, string_t reason, uint32_t loglevel);
+static bool_t initiate_key_setup(struct site *st, string_t reason);
static void enter_state_run(struct site *st);
static bool_t enter_state_resolve(struct site *st);
static bool_t enter_state_sentmsg1(struct site *st);
/* We are going to add three words to the transformed message */
buffer_init(&st->buffer,st->transform->max_start_pad+(4*3));
buf_append_uint32(&st->buffer,LABEL_MSG5);
+ /* Give the netlink code an opportunity to put its own stuff in the
+ message (configuration information, etc.) */
+ st->netlink->output_config(st->netlink->st,&st->buffer);
st->new_transform->forwards(st->new_transform->st,&st->buffer,
&transform_err);
buf_prepend_uint32(&st->buffer,LABEL_MSG5);
slog(st,LOG_SEC,"MSG5/PING packet contained invalid data");
return False;
}
+ if (!st->netlink->check_config(st->netlink->st,msg5)) {
+ slog(st,LOG_SEC,"MSG5/PING packet contained bad netlink config");
+ return False;
+ }
CHECK_EMPTY(msg5);
return True;
}
/* We are going to add three words to the transformed message */
buffer_init(&st->buffer,st->transform->max_start_pad+(4*3));
buf_append_uint32(&st->buffer,LABEL_MSG6);
+ /* Give the netlink code an opportunity to put its own stuff in the
+ message (configuration information, etc.) */
+ st->netlink->output_config(st->netlink->st,&st->buffer);
st->new_transform->forwards(st->new_transform->st,&st->buffer,
&transform_err);
buf_prepend_uint32(&st->buffer,LABEL_MSG6);
slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
return False;
}
+ if (!st->netlink->check_config(st->netlink->st,msg6)) {
+ slog(st,LOG_SEC,"MSG6/PONG packet contained bad netlink config");
+ return False;
+ }
CHECK_EMPTY(msg6);
return True;
}
if (!st->current_valid) {
slog(st,LOG_DROP,"incoming message but no current key -> dropping");
- if (st->state==SITE_RUN) {
- slog(st,LOG_SETUP_INIT|LOG_STATE,
- "now initiating setup of new key");
- return enter_state_resolve(st);
- }
- return False;
+ return initiate_key_setup(st,"incoming message but no current key");
}
if (!unpick_msg0(st,msg0,&m)) return False;
msg0,&transform_err)) {
/* There's a problem */
slog(st,LOG_SEC,"transform: %s",transform_err);
- return False;
+ return initiate_key_setup(st,"incoming message would not decrypt");
}
CHECK_AVAIL(msg0,4);
type=buf_unprepend_uint32(msg0);
switch(type) {
+ case LABEL_MSG7:
+ /* We must forget about the current session. */
+ delete_key(st,"request from peer",LOG_SEC);
+ return True;
+ break;
case LABEL_MSG9:
/* Deliver to netlink layer */
- st->netlink->deliver(st->netlink->st,st->netlink_cid,msg0);
+ st->netlink->deliver(st->netlink->st,msg0);
return True;
break;
default:
uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8));
if (st->log_events & LOG_DUMP)
- log(st->log,0,"(%s,%s): %s: %08x<-%08x: %08x:",
- st->localname,st->remotename,incoming?"incoming":"outgoing",
+ log(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
+ st->tunname,incoming?"incoming":"outgoing",
dest,source,msgtype);
}
st->retries--;
return True;
} else {
- slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet");
+ slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet "
+ "(in state %s)",state_name(st->state));
enter_state_wait(st);
return False;
}
}
}
+static bool_t initiate_key_setup(struct site *st,string_t reason)
+{
+ if (st->state!=SITE_RUN) return False;
+ slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
+ if (st->address) {
+ slog(st,LOG_SETUP_INIT,"resolving peer address");
+ return enter_state_resolve(st);
+ } else if (st->peer_valid) {
+ slog(st,LOG_SETUP_INIT,"using old peer address");
+ st->setup_peer=st->peer;
+ return enter_state_sentmsg1(st);
+ }
+ return False;
+}
+
static void activate_new_key(struct site *st)
{
struct transform_inst_if *t;
st->new_transform=t;
t->delkey(t->st);
- st->state=SITE_RUN;
st->timeout=0;
st->current_valid=True;
st->current_key_timeout=st->now+st->key_lifetime;
st->remote_session_id=st->setup_session_id;
slog(st,LOG_ACTIVATE_KEY,"new key activated");
+ enter_state_run(st);
+}
+
+static void delete_key(struct site *st, string_t reason, uint32_t loglevel)
+{
+ if (st->current_valid) {
+ slog(st,loglevel,"session closed (%s)",reason);
+
+ st->current_valid=False;
+ st->current_transform->delkey(st->current_transform->st);
+ st->current_key_timeout=0;
+ set_link_quality(st);
+ }
}
static void state_assert(struct site *st, bool_t ok)
{
st->state=SITE_STOP;
st->timeout=0;
- st->current_transform->delkey(st->current_transform->st);
- st->current_valid=False;
- st->current_key_timeout=0;
-
- st->peer_valid=False;
-
+ delete_key(st,"entering state STOP",LOG_TIMEOUT_KEY);
st->new_transform->delkey(st->new_transform->st);
}
+static void set_link_quality(struct site *st)
+{
+ uint32_t quality;
+ if (st->current_valid)
+ quality=LINK_QUALITY_UP;
+ else if (st->state==SITE_WAIT || st->state==SITE_STOP)
+ quality=LINK_QUALITY_DOWN;
+ else if (st->address)
+ quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
+ else if (st->peer_valid)
+ quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
+ else
+ quality=LINK_QUALITY_DOWN;
+
+ st->netlink->set_quality(st->netlink->st,quality);
+}
+
static void enter_state_run(struct site *st)
{
slog(st,LOG_STATE,"entering state RUN");
st->state=SITE_RUN;
st->timeout=0;
- st->netlink->set_delivery(st->netlink->st,st->netlink_cid,True);
+
+ set_link_quality(st);
/* XXX get rid of key setup data */
}
return False;
}
+static bool_t send_msg7(struct site *st,string_t reason)
+{
+ string_t transform_err;
+
+ if (st->current_valid && st->peer_valid && st->buffer.free) {
+ BUF_ALLOC(&st->buffer,"site:MSG7");
+ buffer_init(&st->buffer,st->transform->max_start_pad+(4*3));
+ buf_append_uint32(&st->buffer,LABEL_MSG7);
+ buf_append_string(&st->buffer,reason);
+ st->current_transform->forwards(st->current_transform->st,
+ &st->buffer, &transform_err);
+ buf_prepend_uint32(&st->buffer,LABEL_MSG0);
+ buf_prepend_uint32(&st->buffer,(uint32_t)st);
+ buf_prepend_uint32(&st->buffer,st->remote_session_id);
+ st->comm->sendmsg(st->comm->st,&st->buffer,&st->peer);
+ BUF_FREE(&st->buffer);
+ return True;
+ }
+ return False;
+}
+
/* We go into this state if our peer becomes uncommunicative. Similar to
the "stop" state, we forget all session keys for a while, before
re-entering the "run" state. */
st->timeout=st->now+st->wait_timeout;
st->state=SITE_WAIT;
st->peer_valid=False;
- st->netlink->set_delivery(st->netlink->st,st->netlink_cid,False);
+ set_link_quality(st);
BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
/* XXX Erase keys etc. */
}
}
}
if (st->current_key_timeout && *now>st->current_key_timeout) {
- slog(st,LOG_TIMEOUT_KEY,"maximum key life exceeded; session closed");
- st->current_valid=False;
- st->current_transform->delkey(st->current_transform->st);
- st->current_key_timeout=0;
+ delete_key(st,"maximum key life exceeded",LOG_TIMEOUT_KEY);
}
}
/* This function is called by the netlink device to deliver packets
intended for the remote network. The packet is in "raw" wire
format, but is guaranteed to be word-aligned. */
-static void site_outgoing(void *sst, void *cid, struct buffer_if *buf)
+static void site_outgoing(void *sst, struct buffer_if *buf)
{
struct site *st=sst;
string_t transform_err;
a valid key and a valid address to send it to. */
if (st->current_valid && st->peer_valid) {
/* Transform it and send it */
- buf_prepend_uint32(buf,LABEL_MSG9);
- st->current_transform->forwards(st->current_transform->st,
- buf, &transform_err);
- buf_prepend_uint32(buf,LABEL_MSG0);
- buf_prepend_uint32(buf,(uint32_t)st);
- buf_prepend_uint32(buf,st->remote_session_id);
- st->comm->sendmsg(st->comm->st,buf,&st->peer);
+ if (buf->size>0) {
+ buf_prepend_uint32(buf,LABEL_MSG9);
+ st->current_transform->forwards(st->current_transform->st,
+ buf, &transform_err);
+ buf_prepend_uint32(buf,LABEL_MSG0);
+ buf_prepend_uint32(buf,(uint32_t)st);
+ buf_prepend_uint32(buf,st->remote_session_id);
+ st->comm->sendmsg(st->comm->st,buf,&st->peer);
+ }
BUF_FREE(buf);
return;
}
- if (st->state==SITE_RUN) {
- BUF_FREE(buf); /* We throw the outgoing packet away */
- slog(st,LOG_SETUP_INIT,"initiating key exchange");
- enter_state_resolve(st);
- return;
- }
-
- /* Otherwise we're in the middle of key setup or a wait - just
- throw the outgoing packet away */
- slog(st,LOG_DROP,"discarding outgoing packet");
+ slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
BUF_FREE(buf);
- return;
+ initiate_key_setup(st,"outgoing packet");
}
/* This function is called by the communication device to deliver
return False; /* Not for us. */
}
if (dest==(uint32_t)st) {
- uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8));
+ uint32_t msgtype=ntohl(get_uint32(buf->start+8));
/* Explicitly addressed to us */
if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
switch (msgtype) {
+ case 0: /* NAK */
+ /* If the source is our current peer then initiate a key setup,
+ because our peer's forgotten the key */
+ if (get_uint32(buf->start+4)==st->remote_session_id) {
+ initiate_key_setup(st,"received a NAK");
+ } else {
+ slog(st,LOG_SEC,"bad incoming NAK");
+ }
+ break;
case LABEL_MSG0:
process_msg0(st,buf,source);
break;
slog(st,LOG_SEC,"invalid MSG6");
}
break;
- case LABEL_MSG8:
- /* NAK packet: enter state where we ping and check for response */
- slog(st,LOG_ERROR,"received a NAK");
- break;
default:
slog(st,LOG_SEC,"received message of unknown type 0x%08x",
msgtype);
else enter_state_stop(st);
}
+static void site_phase_hook(void *sst, uint32_t newphase)
+{
+ struct site *st=sst;
+
+ /* The program is shutting down; tell our peer */
+ send_msg7(st,"shutting down");
+}
+
static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
list_t *args)
{
cfgfatal(loc,"site","parameter must be a dictionary\n");
dict=item->data.dict;
- st->netlink=find_cl_if(dict,"netlink",CL_NETLINK,True,"site",loc);
+ st->localname=dict_read_string(dict, "local-name", True, "site", loc);
+ st->remotename=dict_read_string(dict, "name", True, "site", loc);
+ /* Sanity check (which also allows the 'sites' file to include
+ site() closures for all sites including our own): refuse to
+ talk to ourselves */
+ if (strcmp(st->localname,st->remotename)==0) {
+ Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
+ st->localname);
+ free(st);
+ return NULL;
+ }
+ st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
st->comm=find_cl_if(dict,"comm",CL_COMM,True,"site",loc);
st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
- st->localname=dict_read_string(dict, "local-name", True, "site", loc);
st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
- st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
-
- st->remotename=dict_read_string(dict, "name", True, "site", loc);
st->address=dict_read_string(dict, "address", False, "site", loc);
- dict_read_subnet_list(dict, "networks", True, "site", loc,
- &st->remotenets);
+ if (st->address)
+ st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
+ else st->remoteport=0;
st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
st->transform=
st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
- st->key_lifetime=dict_read_number(dict,"key-lifetime",
- False,"site",loc,DEFAULT_KEY_LIFETIME);
- st->setup_retries=dict_read_number(dict,"setup-retries",
- False,"site",loc,DEFAULT_SETUP_RETRIES);
- st->setup_timeout=dict_read_number(dict,"setup-timeout",
- False,"site",loc,DEFAULT_SETUP_TIMEOUT);
- st->wait_timeout=dict_read_number(dict,"wait-time",
- False,"site",loc,DEFAULT_WAIT_TIME);
- /* XXX should be configurable */
- st->log_events=LOG_SEC|LOG_ERROR|
- LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SETUP_INIT|LOG_SETUP_TIMEOUT;
+ st->key_lifetime=dict_read_number(
+ dict,"key-lifetime",False,"site",loc,DEFAULT_KEY_LIFETIME);
+ if (st->key_lifetime < DEFAULT_KEY_RENEGOTIATE_GAP)
+ st->key_renegotiate_time=st->key_lifetime/2;
+ else
+ st->key_renegotiate_time=st->key_lifetime-DEFAULT_KEY_RENEGOTIATE_GAP;
+ st->setup_retries=dict_read_number(
+ dict,"setup-retries",False,"site",loc,DEFAULT_SETUP_RETRIES);
+ st->setup_timeout=dict_read_number(
+ dict,"setup-timeout",False,"site",loc,DEFAULT_SETUP_TIMEOUT);
+ st->wait_timeout=dict_read_number(
+ dict,"wait-time",False,"site",loc,DEFAULT_WAIT_TIME);
+ st->key_renegotiate_time=dict_read_number(
+ dict,"renegotiate-time",False,"site",loc,st->key_lifetime);
+ if (st->key_renegotiate_time > st->key_lifetime) {
+ cfgfatal(loc,"site",
+ "renegotiate-time must be less than key-lifetime\n");
+ }
+ /* XXX keepalive will eventually default to True */
+ st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
+
+ st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
+ log_event_table,"site");
st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
"site_apply");
sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
/* The information we expect to see in incoming messages of type 1 */
- /* XXX fix this bit for unaligned access */
st->setupsiglen=strlen(st->remotename)+strlen(st->localname)+8;
st->setupsig=safe_malloc(st->setupsiglen,"site_apply");
- *(uint32_t *)&(st->setupsig[0])=LABEL_MSG1;
- *(uint16_t *)&(st->setupsig[4])=htons(strlen(st->remotename));
+ put_uint32(st->setupsig+0,LABEL_MSG1);
+ put_uint16(st->setupsig+4,strlen(st->remotename));
memcpy(&st->setupsig[6],st->remotename,strlen(st->remotename));
- *(uint16_t *)&(st->setupsig[6+strlen(st->remotename)])=
- htons(strlen(st->localname));
+ put_uint16(st->setupsig+(6+strlen(st->remotename)),strlen(st->localname));
memcpy(&st->setupsig[8+strlen(st->remotename)],st->localname,
strlen(st->localname));
st->setup_priority=(strcmp(st->localname,st->remotename)>0);
st->sharedsecret=safe_malloc(st->transform->keylen,"site:sharedsecret");
/* We need to register the remote networks with the netlink device */
- st->netlink_cid=st->netlink->regnets(st->netlink->st, &st->remotenets,
- site_outgoing, st,
- st->transform->max_start_pad+(4*4),
- st->transform->max_end_pad,
- st->tunname);
+ st->netlink->reg(st->netlink->st, site_outgoing, st,
+ st->transform->max_start_pad+(4*4),
+ st->transform->max_end_pad);
st->comm->request_notify(st->comm->st, st, site_incoming);
enter_state_stop(st);
+ add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
+
return new_closure(&st->cl);
}