/* site.c - manage communication with a remote network site */
+/* 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). */
+
+/* At some point in the future the netlink code will be asked for
+ configuration information to go in the PING/PONG packets at the end
+ of the key exchange. */
+
#include "secnet.h"
#include <stdio.h>
-/* MBM asserts the next one is needed for compilation under BSD. */
+#include <string.h>
+#include <limits.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include "util.h"
#include "unaligned.h"
+#include "magic.h"
#define SETUP_BUFFER_LEN 2048
#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_SETUP_TIMEOUT 2000
+#define DEFAULT_WAIT_TIME 20000
/* Each site can be in one of several possible states. */
#define SITE_SENTMSG5 7
#define SITE_WAIT 8
-#if 0
-static string_t state_name(uint32_t state)
+static cstring_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*";
}
}
-#endif /* 0 */
-
-#define LABEL_MSG0 0x00020200
-#define LABEL_MSG1 0x01010101
-#define LABEL_MSG2 0x02020202
-#define LABEL_MSG3 0x03030303
-#define LABEL_MSG4 0x04040404
-#define LABEL_MSG5 0x05050505
-#define LABEL_MSG6 0x06060606
-#define LABEL_MSG7 0x07070707
-#define LABEL_MSG8 0x08080808
-#define LABEL_MSG9 0x09090909
#define NONCELEN 8
{ "packet-drop", LOG_DROP },
{ "dump-packets", LOG_DUMP },
{ "errors", LOG_ERROR },
+ { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
+ LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
{ "all", 0xffffffff },
{ NULL, 0 }
};
/* configuration information */
string_t localname;
string_t remotename;
- string_t tunname; /* localname<->remotename by default */
+ string_t tunname; /* localname<->remotename by default, used in logs */
string_t address; /* DNS name for bootstrapping, optional */
- int remoteport;
+ int remoteport; /* Port for bootstrapping, optional */
struct netlink_if *netlink;
struct comm_if *comm;
struct resolver_if *resolver;
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;
- 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)
+ int32_t setup_retries; /* How many times to send setup packets */
+ int32_t setup_timeout; /* Initial timeout for setup packets */
+ int32_t wait_timeout; /* How long to wait if setup unsuccessful */
+ int32_t key_lifetime; /* How long a key lasts once set up */
+ int32_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 */
+ bool_t keepalive; /* Send keepalives to detect peer failure (not yet
+ implemented) */
uint8_t *setupsig; /* Expected signature of incoming MSG1 packets */
- uint32_t setupsiglen; /* Allows us to discard packets quickly if
- they are not for us */
+ int32_t setupsiglen; /* Allows us to discard packets quickly if
+ they are not for us */
bool_t setup_priority; /* Do we have precedence if both sites emit
message 1 simultaneously? */
uint32_t log_events;
uint32_t state;
uint64_t now; /* Most recently seen time */
- void *netlink_cid;
-
+ /* The currently established session */
uint32_t remote_session_id;
struct transform_inst_if *current_transform;
bool_t current_valid;
uint64_t current_key_timeout; /* End of life of current key */
+ uint64_t renegotiate_key_time; /* When we can negotiate a new key */
struct sockaddr_in peer; /* Current address of peer */
bool_t peer_valid; /* Peer address becomes invalid when key times out,
but only if we have a DNS name for our peer */
+ /* The current key setup protocol exchange. We can only be
+ involved in one of these at a time. There's a potential for
+ denial of service here (the attacker keeps sending a setup
+ packet; we keep trying to continue the exchange, and have to
+ timeout before we can listen for another setup packet); perhaps
+ we should keep a list of 'bad' sources for setup packets. */
uint32_t setup_session_id;
struct sockaddr_in setup_peer;
uint8_t localN[NONCELEN]; /* Nonces for key exchange */
uint8_t remoteN[NONCELEN];
struct buffer_if buffer; /* Current outgoing key exchange packet */
- uint32_t retries; /* Number of retries remaining */
+ int32_t retries; /* Number of retries remaining */
uint64_t timeout; /* Timeout for current state */
uint8_t *dhsecret;
uint8_t *sharedsecret;
-
struct transform_inst_if *new_transform; /* For key setup/verify */
};
-static void slog(struct site *st, uint32_t event, string_t msg, ...)
+static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
{
va_list ap;
- uint8_t buf[240];
+ char 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 bool_t initiate_key_setup(struct site *st);
+static void delete_key(struct site *st, cstring_t reason, uint32_t loglevel);
+static bool_t initiate_key_setup(struct site *st, cstring_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);
-static bool_t enter_state_sentmsg2(struct site *st);
-static bool_t enter_state_sentmsg3(struct site *st);
-static bool_t enter_state_sentmsg4(struct site *st);
-static bool_t enter_state_sentmsg5(struct site *st);
+static bool_t enter_new_state(struct site *st,uint32_t next);
static void enter_state_wait(struct site *st);
#define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
uint8_t *hashstart;
uint32_t dest;
uint32_t source;
- uint32_t remlen;
+ int32_t remlen;
uint8_t *remote;
- uint32_t loclen;
+ int32_t loclen;
uint8_t *local;
uint8_t *nR;
uint8_t *nL;
- uint32_t pklen;
+ int32_t pklen;
uint8_t *pk;
- uint32_t hashlen;
- uint32_t siglen;
+ int32_t hashlen;
+ int32_t siglen;
uint8_t *sig;
};
-/* Build any of msg1 to msg4. msg5 and msg6 are built from the inside out
- using a transform. */
-static bool_t generate_msg(struct site *st, uint32_t type, string_t what)
+/* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
+ out using a transform of config data supplied by netlink */
+static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
{
void *hst;
- uint8_t *hash=alloca(st->hash->len);
+ uint8_t *hash;
string_t dhpub, sig;
st->retries=st->setup_retries;
if (type==LABEL_MSG1) return True;
memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN);
if (type==LABEL_MSG2) return True;
+
+ if (hacky_par_mid_failnow()) return False;
+
dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
buf_append_string(&st->buffer,dhpub);
free(dhpub);
+ hash=safe_malloc(st->hash->len, "generate_msg");
hst=st->hash->init();
st->hash->update(hst,st->buffer.start,st->buffer.size);
st->hash->final(hst,hash);
sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
buf_append_string(&st->buffer,sig);
free(sig);
+ free(hash);
return True;
}
return True;
}
+static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
+ cstring_t *error)
+{
+ if (type==LABEL_MSG1) return True;
+
+ /* Check that the site names and our nonce have been sent
+ back correctly, and then store our peer's nonce. */
+ if (memcmp(m->remote,st->remotename,strlen(st->remotename)!=0)) {
+ *error="wrong remote site name";
+ return False;
+ }
+ if (memcmp(m->local,st->localname,strlen(st->localname)!=0)) {
+ *error="wrong local site name";
+ return False;
+ }
+ if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
+ *error="wrong locally-generated nonce";
+ return False;
+ }
+ if (type==LABEL_MSG2) return True;
+ if (memcmp(m->nR,st->remoteN,NONCELEN)!=0) {
+ *error="wrong remotely-generated nonce";
+ return False;
+ }
+ if (type==LABEL_MSG3) return True;
+ if (type==LABEL_MSG4) return True;
+ *error="unknown message type";
+ return False;
+}
+
static bool_t generate_msg1(struct site *st)
{
st->random->generate(st->random->st,NONCELEN,st->localN);
if (!unpick_msg(st,LABEL_MSG1,msg1,&m)) return False;
- /* XXX save src as our peer address here? */
st->setup_peer=*src;
-
st->setup_session_id=m.source;
memcpy(st->remoteN,m.nR,NONCELEN);
return True;
struct sockaddr_in *src)
{
struct msg m;
+ cstring_t err;
if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
-
- /* Check that the site names and our nonce have been sent
- back correctly, and then store our peer's nonce. */
- if (memcmp(m.remote,st->remotename,strlen(st->remotename)!=0)) {
- slog(st,LOG_SEC,"msg2: bad B (remote site name)");
- return False;
- }
- if (memcmp(m.local,st->localname,strlen(st->localname)!=0)) {
- slog(st,LOG_SEC,"msg2: bad A (local site name)");
- return False;
- }
- if (memcmp(m.nL,st->localN,NONCELEN)!=0) {
- slog(st,LOG_SEC,"msg2: bad nA (locally generated nonce)");
+ if (!check_msg(st,LABEL_MSG2,&m,&err)) {
+ slog(st,LOG_SEC,"msg2: %s",err);
return False;
}
st->setup_session_id=m.source;
struct sockaddr_in *src)
{
struct msg m;
- uint8_t *hash=alloca(st->hash->len);
+ uint8_t *hash;
void *hst;
+ cstring_t err;
if (!unpick_msg(st,LABEL_MSG3,msg3,&m)) return False;
-
- /* Check that the site names and nonces have been sent back
- correctly */
- if (memcmp(m.remote,st->remotename,strlen(st->remotename)!=0)) {
- slog(st,LOG_SEC,"msg3: bad A (remote site name)");
- return False;
- }
- if (memcmp(m.local,st->localname,strlen(st->localname)!=0)) {
- slog(st,LOG_SEC,"msg3: bad B (local site name)");
- return False;
- }
- if (memcmp(m.nR,st->remoteN,NONCELEN)!=0) {
- slog(st,LOG_SEC,"msg3: bad nA (remotely generated nonce)");
+ if (!check_msg(st,LABEL_MSG3,&m,&err)) {
+ slog(st,LOG_SEC,"msg3: %s",err);
return False;
}
- if (memcmp(m.nL,st->localN,NONCELEN)!=0) {
- slog(st,LOG_SEC,"msg3: bad nB (locally generated nonce)");
- return False;
- }
-
+
/* Check signature and store g^x mod m */
+ hash=safe_malloc(st->hash->len, "process_msg3");
hst=st->hash->init();
st->hash->update(hst,m.hashstart,m.hashlen);
st->hash->final(hst,hash);
m.sig[m.siglen]=0;
if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
slog(st,LOG_SEC,"msg3 signature failed check!");
+ free(hash);
return False;
}
+ free(hash);
/* Terminate their DH public key with a '0' */
m.pk[m.pklen]=0;
struct sockaddr_in *src)
{
struct msg m;
- uint8_t *hash=alloca(st->hash->len);
+ uint8_t *hash;
void *hst;
+ cstring_t err;
if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
-
- /* Check that the site names and nonces have been sent back
- correctly */
- if (memcmp(m.remote,st->remotename,strlen(st->remotename)!=0)) {
- slog(st,LOG_SEC,"msg4: bad B (remote site name)");
- return False;
- }
- if (memcmp(m.local,st->localname,strlen(st->localname)!=0)) {
- slog(st,LOG_SEC,"msg4: bad A (local site name)");
- return False;
- }
- if (memcmp(m.nR,st->remoteN,NONCELEN)!=0) {
- slog(st,LOG_SEC,"msg4: bad nB (remotely generated nonce)");
- return False;
- }
- if (memcmp(m.nL,st->localN,NONCELEN)!=0) {
- slog(st,LOG_SEC,"msg4: bad nA (locally generated nonce)");
+ if (!check_msg(st,LABEL_MSG4,&m,&err)) {
+ slog(st,LOG_SEC,"msg4: %s",err);
return False;
}
/* Check signature and store g^x mod m */
+ hash=safe_malloc(st->hash->len, "process_msg4");
hst=st->hash->init();
st->hash->update(hst,m.hashstart,m.hashlen);
st->hash->final(hst,hash);
m.sig[m.siglen]=0;
if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
slog(st,LOG_SEC,"msg4 signature failed check!");
+ free(hash);
return False;
}
+ free(hash);
/* Terminate their DH public key with a '0' */
m.pk[m.pklen]=0;
return True;
}
-static bool_t generate_msg5(struct site *st)
-{
- string_t transform_err;
-
- BUF_ALLOC(&st->buffer,"site:MSG5");
- /* 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);
- st->new_transform->forwards(st->new_transform->st,&st->buffer,
- &transform_err);
- buf_prepend_uint32(&st->buffer,LABEL_MSG5);
- buf_prepend_uint32(&st->buffer,(uint32_t)st);
- buf_prepend_uint32(&st->buffer,st->setup_session_id);
-
- st->retries=st->setup_retries;
- return True;
-}
-
struct msg0 {
uint32_t dest;
uint32_t source;
/* Leaves transformed part of buffer untouched */
}
+static bool_t generate_msg5(struct site *st)
+{
+ cstring_t transform_err;
+
+ BUF_ALLOC(&st->buffer,"site:MSG5");
+ /* We are going to add four words to the message */
+ buffer_init(&st->buffer,st->transform->max_start_pad+(4*4));
+ /* 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);
+ buf_prepend_uint32(&st->buffer,LABEL_MSG5);
+ st->new_transform->forwards(st->new_transform->st,&st->buffer,
+ &transform_err);
+ buf_prepend_uint32(&st->buffer,LABEL_MSG5);
+ buf_prepend_uint32(&st->buffer,(uint32_t)st);
+ buf_prepend_uint32(&st->buffer,st->setup_session_id);
+
+ st->retries=st->setup_retries;
+ return True;
+}
+
static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
struct sockaddr_in *src)
{
struct msg0 m;
- string_t transform_err;
+ cstring_t transform_err;
if (!unpick_msg0(st,msg5,&m)) return False;
/* Buffer should now contain untransformed PING packet data */
CHECK_AVAIL(msg5,4);
if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
- slog(st,LOG_SEC,"MSG5/PING packet contained invalid data");
+ slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
+ 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);
static bool_t generate_msg6(struct site *st)
{
- string_t transform_err;
+ cstring_t transform_err;
BUF_ALLOC(&st->buffer,"site:MSG6");
- /* 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);
+ /* We are going to add four words to the message */
+ buffer_init(&st->buffer,st->transform->max_start_pad+(4*4));
+ /* 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);
+ buf_prepend_uint32(&st->buffer,LABEL_MSG6);
st->new_transform->forwards(st->new_transform->st,&st->buffer,
&transform_err);
buf_prepend_uint32(&st->buffer,LABEL_MSG6);
buf_prepend_uint32(&st->buffer,(uint32_t)st);
buf_prepend_uint32(&st->buffer,st->setup_session_id);
- st->retries=1; /* Peer will retransmit MSG5 if necessary */
+ st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
return True;
}
struct sockaddr_in *src)
{
struct msg0 m;
- string_t transform_err;
+ cstring_t transform_err;
if (!unpick_msg0(st,msg6,&m)) return False;
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;
}
struct sockaddr_in *src)
{
struct msg0 m;
- string_t transform_err;
+ cstring_t transform_err;
uint32_t type;
if (!st->current_valid) {
slog(st,LOG_DROP,"incoming message but no current key -> dropping");
- return initiate_key_setup(st);
+ 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:
- slog(st,LOG_SEC,"incoming message of type %08x (unknown)",type);
+ slog(st,LOG_SEC,"incoming encrypted message of type %08x "
+ "(unknown)",type);
break;
}
return False;
uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8));
if (st->log_events & LOG_DUMP)
- log(st->log,0,"%s: %s: %08x<-%08x: %08x:",
- st->tunname,incoming?"incoming":"outgoing",
- dest,source,msgtype);
+ slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
+ st->tunname,incoming?"incoming":"outgoing",
+ dest,source,msgtype);
}
static uint32_t site_status(void *st)
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;
}
st->setup_peer.sin_family=AF_INET;
st->setup_peer.sin_port=htons(st->remoteport);
st->setup_peer.sin_addr=*address;
- enter_state_sentmsg1(st);
+ enter_new_state(st,SITE_SENTMSG1);
} else {
/* Resolution failed */
slog(st,LOG_ERROR,"resolution of %s failed",st->address);
}
}
-static bool_t initiate_key_setup(struct site *st)
+static bool_t initiate_key_setup(struct site *st, cstring_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,"initiating key exchange; resolving address");
+ slog(st,LOG_SETUP_INIT,"resolving peer address");
return enter_state_resolve(st);
} else if (st->peer_valid) {
- slog(st,LOG_SETUP_INIT,"initiating key exchange using old "
- "peer address");
+ slog(st,LOG_SETUP_INIT,"using old peer address");
st->setup_peer=st->peer;
- return enter_state_sentmsg1(st);
+ return enter_new_state(st,SITE_SENTMSG1);
}
+ slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
return False;
}
{
struct transform_inst_if *t;
+ /* We have two transform instances, which we swap between active
+ and setup */
t=st->current_transform;
st->current_transform=st->new_transform;
st->new_transform=t;
st->timeout=0;
st->current_valid=True;
st->current_key_timeout=st->now+st->key_lifetime;
+ st->renegotiate_key_time=st->now+st->key_renegotiate_time;
st->peer=st->setup_peer;
st->peer_valid=True;
st->remote_session_id=st->setup_session_id;
enter_state_run(st);
}
+static void delete_key(struct site *st, cstring_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)
{
- if (!ok) fatal("state_assert\n");
+ if (!ok) fatal("site:state_assert");
}
static void enter_state_stop(struct site *st)
{
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;
-
- set_link_quality(st);
-
+ delete_key(st,"entering state STOP",LOG_TIMEOUT_KEY);
st->new_transform->delkey(st->new_transform->st);
}
else
quality=LINK_QUALITY_DOWN;
- st->netlink->set_quality(st->netlink->st,st->netlink_cid,quality);
+ st->netlink->set_quality(st->netlink->st,quality);
}
static void enter_state_run(struct site *st)
st->state=SITE_RUN;
st->timeout=0;
+ st->setup_session_id=0;
+ memset(&st->setup_peer,0,sizeof(st->setup_peer));
+ memset(st->localN,0,NONCELEN);
+ memset(st->remoteN,0,NONCELEN);
+ st->new_transform->delkey(st->new_transform->st);
+ memset(st->dhsecret,0,st->dh->len);
+ memset(st->sharedsecret,0,st->transform->keylen);
set_link_quality(st);
- /* XXX get rid of key setup data */
}
static bool_t enter_state_resolve(struct site *st)
return True;
}
-static bool_t enter_state_sentmsg1(struct site *st)
-{
- state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
- slog(st,LOG_STATE,"entering state SENTMSG1");
- if (generate_msg1(st) && send_msg(st)) {
- st->state=SITE_SENTMSG1;
- return True;
- }
- slog(st,LOG_ERROR,"error entering state SENTMSG1");
- st->buffer.free=False; /* Can't tell which it was, but enter_state_wait()
- will do a BUF_FREE() */
- enter_state_wait(st);
- return False;
-}
-
-static bool_t enter_state_sentmsg2(struct site *st)
-{
- state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
- st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
- slog(st,LOG_STATE,"entering state SENTMSG2");
- if (generate_msg2(st) && send_msg(st)) {
- st->state=SITE_SENTMSG2;
- return True;
- }
- slog(st,LOG_ERROR,"error entering state SENTMSG2");
- st->buffer.free=False;
- enter_state_wait(st);
- return False;
-}
-
-static bool_t enter_state_sentmsg3(struct site *st)
+static bool_t enter_new_state(struct site *st, uint32_t next)
{
- state_assert(st,st->state==SITE_SENTMSG1);
- slog(st,LOG_STATE,"entering state SENTMSG3");
- BUF_FREE(&st->buffer); /* Free message 1 */
- if (generate_msg3(st) && send_msg(st)) {
- st->state=SITE_SENTMSG3;
- return True;
+ bool_t (*gen)(struct site *st);
+ int r;
+
+ slog(st,LOG_STATE,"entering state %s",state_name(next));
+ switch(next) {
+ case SITE_SENTMSG1:
+ state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
+ gen=generate_msg1;
+ break;
+ case SITE_SENTMSG2:
+ state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
+ st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
+ gen=generate_msg2;
+ break;
+ case SITE_SENTMSG3:
+ state_assert(st,st->state==SITE_SENTMSG1);
+ BUF_FREE(&st->buffer);
+ gen=generate_msg3;
+ break;
+ case SITE_SENTMSG4:
+ state_assert(st,st->state==SITE_SENTMSG2);
+ BUF_FREE(&st->buffer);
+ gen=generate_msg4;
+ break;
+ case SITE_SENTMSG5:
+ state_assert(st,st->state==SITE_SENTMSG3);
+ BUF_FREE(&st->buffer);
+ gen=generate_msg5;
+ break;
+ case SITE_RUN:
+ state_assert(st,st->state==SITE_SENTMSG4);
+ BUF_FREE(&st->buffer);
+ gen=generate_msg6;
+ break;
+ default:
+ gen=NULL;
+ fatal("enter_new_state(%s): invalid new state",state_name(next));
+ break;
}
- slog(st,LOG_ERROR,"error entering state SENTMSG3");
- st->buffer.free=False;
- enter_state_wait(st);
- return False;
-}
-static bool_t enter_state_sentmsg4(struct site *st)
-{
- state_assert(st,st->state==SITE_SENTMSG2);
- slog(st,LOG_STATE,"entering state SENTMSG4");
- BUF_FREE(&st->buffer); /* Free message 2 */
- if (generate_msg4(st) && send_msg(st)) {
- st->state=SITE_SENTMSG4;
- return True;
- }
- slog(st,LOG_ERROR,"error entering state SENTMSG4");
- st->buffer.free=False;
- enter_state_wait(st);
- return False;
-}
+ if (hacky_par_start_failnow()) return False;
-static bool_t enter_state_sentmsg5(struct site *st)
-{
- state_assert(st,st->state==SITE_SENTMSG3);
- slog(st,LOG_STATE,"entering state SENTMSG5");
- BUF_FREE(&st->buffer); /* Free message 3 */
+ r= gen(st) && send_msg(st);
- if (generate_msg5(st) && send_msg(st)) {
- st->state=SITE_SENTMSG5;
+ hacky_par_end(&r,
+ st->setup_retries, st->setup_timeout,
+ send_msg, st);
+
+ if (r) {
+ st->state=next;
+ if (next==SITE_RUN) {
+ BUF_FREE(&st->buffer); /* Never reused */
+ st->timeout=0; /* Never retransmit */
+ activate_new_key(st);
+ }
return True;
}
- slog(st,LOG_ERROR,"error entering state SENTMSG5");
- st->buffer.free=False;
+ slog(st,LOG_ERROR,"error entering state %s",state_name(next));
+ st->buffer.free=False; /* Unconditionally use the buffer; it may be
+ in either state, and enter_state_wait() will
+ do a BUF_FREE() */
enter_state_wait(st);
-
return False;
}
-static bool_t send_msg6(struct site *st)
+/* msg7 tells our peer that we're about to forget our key */
+static bool_t send_msg7(struct site *st, cstring_t reason)
{
- state_assert(st,st->state==SITE_SENTMSG4);
- slog(st,LOG_STATE,"entering state RUN after sending msg6");
- BUF_FREE(&st->buffer); /* Free message 4 */
- if (generate_msg6(st) && send_msg(st)) {
- BUF_FREE(&st->buffer); /* Never reused */
- st->timeout=0; /* Never retransmit */
- activate_new_key(st);
+ cstring_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;
}
- slog(st,LOG_ERROR,"error entering state RUN after sending msg6");
- st->buffer.free=False;
- enter_state_wait(st);
return False;
}
/* XXX Erase keys etc. */
}
+static inline void site_settimeout(uint64_t timeout, int *timeout_io)
+{
+ if (timeout) {
+ int64_t offset=timeout-*now;
+ if (offset<0) offset=0;
+ if (offset>INT_MAX) offset=INT_MAX;
+ if (*timeout_io<0 || offset<*timeout_io)
+ *timeout_io=offset;
+ }
+}
+
static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
- int *timeout_io, const struct timeval *tv_now,
- uint64_t *now)
+ int *timeout_io)
{
struct site *st=sst;
/* Work out when our next timeout is. The earlier of 'timeout' or
'current_key_timeout'. A stored value of '0' indicates no timeout
active. */
- if (st->timeout && st->timeout-*now < *timeout_io) {
- *timeout_io=st->timeout-*now;
- }
-
- if (st->current_key_timeout && st->current_key_timeout-*now < *timeout_io)
- *timeout_io=st->current_key_timeout-*now;
+ site_settimeout(st->timeout, timeout_io);
+ site_settimeout(st->current_key_timeout, timeout_io);
return 0; /* success */
}
/* NB site_afterpoll will be called before site_beforepoll is ever called */
-static void site_afterpoll(void *sst, struct pollfd *fds, int nfds,
- const struct timeval *tv_now, uint64_t *now)
+static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
{
struct site *st=sst;
st->now=*now;
if (st->timeout && *now>st->timeout) {
- /* Do stuff */
st->timeout=0;
- if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5)
- send_msg(st);
- else if (st->state==SITE_WAIT) {
+ if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
+ if (!hacky_par_start_failnow())
+ send_msg(st);
+ } else if (st->state==SITE_WAIT) {
enter_state_run(st);
} else {
slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
}
}
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;
- set_link_quality(st);
+ 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;
+ cstring_t transform_err;
if (st->state==SITE_STOP) {
BUF_FREE(buf);
st->comm->sendmsg(st->comm->st,buf,&st->peer);
}
BUF_FREE(buf);
+ /* See whether we should start negotiating a new key */
+ if (st->now > st->renegotiate_key_time)
+ initiate_key_setup(st,"outgoing packet in renegotiation window");
return;
}
slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
BUF_FREE(buf);
- initiate_key_setup(st);
+ initiate_key_setup(st,"outgoing packet");
}
/* This function is called by the communication device to deliver
uint32_t dest=ntohl(*(uint32_t *)buf->start);
if (dest==0) {
- if (buf->size<(st->setupsiglen+8+NONCELEN)) return False;
/* It could be for any site - it should have LABEL_MSG1 and
might have our name and our peer's name in it */
+ if (buf->size<(st->setupsiglen+8+NONCELEN)) return False;
if (memcmp(buf->start+8,st->setupsig,st->setupsiglen)==0) {
- dump_packet(st,buf,source,True);
/* It's addressed to us. Decide what to do about it. */
+ dump_packet(st,buf,source,True);
if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
st->state==SITE_WAIT) {
/* We should definitely process it */
if (process_msg1(st,buf,source)) {
slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
- enter_state_sentmsg2(st);
+ enter_new_state(st,SITE_SENTMSG2);
} else {
slog(st,LOG_ERROR,"failed to process incoming msg1");
}
BUF_FREE(buf);
return True;
- }
- if (st->state==SITE_SENTMSG1) {
+ } else if (st->state==SITE_SENTMSG1) {
/* We've just sent a message 1! They may have crossed on
the wire. If we have priority then we ignore the
incoming one, otherwise we process it as usual. */
"priority => use incoming msg1");
if (process_msg1(st,buf,source)) {
BUF_FREE(&st->buffer); /* Free our old message 1 */
- enter_state_sentmsg2(st);
+ enter_new_state(st,SITE_SENTMSG2);
} else {
slog(st,LOG_ERROR,"failed to process an incoming "
"crossed msg1 (we have low priority)");
return False; /* Not for us. */
}
if (dest==(uint32_t)st) {
- uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8));
/* Explicitly addressed to us */
+ uint32_t msgtype=ntohl(get_uint32(buf->start+8));
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;
if (st->state!=SITE_SENTMSG1) {
slog(st,LOG_UNEXPECTED,"unexpected MSG2");
} else if (process_msg2(st,buf,source))
- enter_state_sentmsg3(st);
+ enter_new_state(st,SITE_SENTMSG3);
else {
slog(st,LOG_SEC,"invalid MSG2");
}
if (st->state!=SITE_SENTMSG2) {
slog(st,LOG_UNEXPECTED,"unexpected MSG3");
} else if (process_msg3(st,buf,source))
- enter_state_sentmsg4(st);
+ enter_new_state(st,SITE_SENTMSG4);
else {
slog(st,LOG_SEC,"invalid MSG3");
}
if (st->state!=SITE_SENTMSG3) {
slog(st,LOG_UNEXPECTED,"unexpected MSG4");
} else if (process_msg4(st,buf,source))
- enter_state_sentmsg5(st);
+ enter_new_state(st,SITE_SENTMSG5);
else {
slog(st,LOG_SEC,"invalid MSG4");
}
and the new key has already been activated. In that
case we should treat it as an ordinary PING packet. We
can't pass it to process_msg5() because the
- new_transform will now be null. XXX) */
+ new_transform will now be unkeyed. XXX) */
if (st->state!=SITE_SENTMSG4) {
slog(st,LOG_UNEXPECTED,"unexpected MSG5");
} else if (process_msg5(st,buf,source)) {
- send_msg6(st);
+ enter_new_state(st,SITE_RUN);
} else {
slog(st,LOG_SEC,"invalid MSG5");
}
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)
{
site() closures for all sites including our own): refuse to
talk to ourselves */
if (strcmp(st->localname,st->remotename)==0) {
- Message(M_INFO,"site %s: local-name==name -> ignoring this site\n",
+ Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
st->localname);
free(st);
return NULL;
}
- st->netlink=find_cl_if(dict,"netlink",CL_NETLINK,True,"site",loc);
+ 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->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
- st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
-
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->key_lifetime=dict_read_number(
dict,"key-lifetime",False,"site",loc,DEFAULT_KEY_LIFETIME);
- if (st->key_lifetime < DEFAULT_KEY_RENEGOTIATE_GAP)
+ if (st->key_lifetime < DEFAULT_KEY_RENEGOTIATE_GAP*2)
st->key_renegotiate_time=st->key_lifetime/2;
else
st->key_renegotiate_time=st->key_lifetime-DEFAULT_KEY_RENEGOTIATE_GAP;
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"),
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 */
+ /* fixme: lots of unchecked overflows here, but the results are only
+ corrupted packets rather than undefined behaviour */
st->setupsiglen=strlen(st->remotename)+strlen(st->localname)+8;
st->setupsig=safe_malloc(st->setupsiglen,"site_apply");
put_uint32(st->setupsig+0,LABEL_MSG1);
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->address!=NULL), st->tunname);
- if (!st->netlink_cid) {
- Message(M_WARNING,"%s: netlink device did not let us register "
- "our remote networks. This site will not start.\n",
- st->tunname);
- return NULL; /* XXX should free site first */
- }
-
+ st->netlink->reg(st->netlink->st, site_outgoing, st,
+ st->transform->max_start_pad+(4*4)+
+ st->comm->min_start_pad,
+ st->transform->max_end_pad+st->comm->min_end_pad);
+
st->comm->request_notify(st->comm->st, st, site_incoming);
st->current_transform=st->transform->create(st->transform->st);
enter_state_stop(st);
+ add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
+
return new_closure(&st->cl);
}
-init_module site_module;
void site_module(dict_t *dict)
{
add_closure(dict,"site",site_apply);
~ianmdlvl / secnet.git / blobdiff