X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=site.c;h=55efa4d512561a1038d31ff0a8d6dc9f58681477;hp=8e7a3fe8c8ed33d3c99815906522116f96343f6e;hb=4f5e39ecfaa49376b0a5c3a4c384e91a828c1105;hpb=7138d0c54cd2212439434d27cb2d6ea775c3039b diff --git a/site.c b/site.c index 8e7a3fe..55efa4d 100644 --- a/site.c +++ b/site.c @@ -1,21 +1,34 @@ /* 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 -/* MBM asserts the next one is needed for compilation under BSD. */ +#include #include #include #include "util.h" -#include "ipaddr.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_SETUP_TIMEOUT 2000 #define DEFAULT_WAIT_TIME 20000 /* Each site can be in one of several possible states. */ @@ -81,17 +94,6 @@ static string_t state_name(uint32_t state) } } -#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 #define LOG_UNEXPECTED 0x00000001 @@ -116,32 +118,27 @@ static struct flagstr log_event_table[]={ { "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 } }; -static struct flagstr netlink_option_table[]={ - { "soft", NETLINK_OPTION_SOFTROUTE }, - { "allow-route", NETLINK_OPTION_ALLOW_ROUTE }, - { NULL, 0} -}; - struct site { closure_t cl; struct site_if ops; /* 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; @@ -154,8 +151,8 @@ struct site { 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 */ + 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 @@ -168,16 +165,22 @@ struct site { 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 */ @@ -187,7 +190,6 @@ struct site { uint64_t timeout; /* Timeout for current state */ uint8_t *dhsecret; uint8_t *sharedsecret; - struct transform_inst_if *new_transform; /* For key setup/verify */ }; @@ -210,8 +212,8 @@ static void slog(struct site *st, uint32_t event, string_t msg, ...) 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_ERROR; break; - default: class=M_ERROR; break; + case LOG_ERROR: class=M_ERR; break; + default: class=M_ERR; break; } vsnprintf(buf,240,msg,ap); @@ -221,14 +223,11 @@ static void slog(struct site *st, uint32_t event, string_t msg, ...) } static void set_link_quality(struct site *st); -static bool_t initiate_key_setup(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); -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) @@ -255,8 +254,8 @@ struct msg { uint8_t *sig; }; -/* Build any of msg1 to msg4. msg5 and msg6 are built from the inside out - using a transform. */ +/* 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, string_t what) { void *hst; @@ -330,6 +329,36 @@ static bool_t unpick_msg(struct site *st, uint32_t type, return True; } +static bool_t check_msg(struct site *st, uint32_t type, struct msg *m, + string_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); @@ -347,9 +376,7 @@ static bool_t process_msg1(struct site *st, struct buffer_if *msg1, 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; @@ -365,21 +392,11 @@ static bool_t process_msg2(struct site *st, struct buffer_if *msg2, struct sockaddr_in *src) { struct msg m; + string_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; @@ -401,28 +418,14 @@ static bool_t process_msg3(struct site *st, struct buffer_if *msg3, struct msg m; uint8_t *hash=alloca(st->hash->len); void *hst; + string_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 */ hst=st->hash->init(); st->hash->update(hst,m.hashstart,m.hashlen); @@ -463,25 +466,11 @@ static bool_t process_msg4(struct site *st, struct buffer_if *msg4, struct msg m; uint8_t *hash=alloca(st->hash->len); void *hst; + string_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; } @@ -508,24 +497,6 @@ static bool_t process_msg4(struct site *st, struct buffer_if *msg4, 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; @@ -545,6 +516,27 @@ static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0, /* Leaves transformed part of buffer untouched */ } +static bool_t generate_msg5(struct site *st) +{ + string_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) { @@ -562,7 +554,11 @@ static bool_t process_msg5(struct site *st, struct buffer_if *msg5, /* 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); @@ -574,16 +570,19 @@ static bool_t generate_msg6(struct site *st) string_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; } @@ -607,6 +606,10 @@ static bool_t process_msg6(struct site *st, struct buffer_if *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; } @@ -620,7 +623,7 @@ static bool_t process_msg0(struct site *st, struct buffer_if *msg0, 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; @@ -629,18 +632,24 @@ static bool_t process_msg0(struct site *st, struct buffer_if *msg0, 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; @@ -693,7 +702,7 @@ static void site_resolve_callback(void *sst, struct in_addr *address) 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); @@ -701,18 +710,19 @@ static void site_resolve_callback(void *sst, struct in_addr *address) } } -static bool_t initiate_key_setup(struct site *st) +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,"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; } @@ -720,6 +730,8 @@ static void activate_new_key(struct site *st) { 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; @@ -728,6 +740,7 @@ static void activate_new_key(struct site *st) 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; @@ -736,23 +749,28 @@ static void activate_new_key(struct site *st) 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) { - 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); } @@ -770,7 +788,7 @@ static void set_link_quality(struct site *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) @@ -779,8 +797,14 @@ 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) @@ -793,97 +817,82 @@ static bool_t enter_state_resolve(struct site *st) return True; } -static bool_t enter_state_sentmsg1(struct site *st) +static bool_t enter_new_state(struct site *st, uint32_t next) { - 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) -{ - 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); + 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; + if (gen(st) && send_msg(st)) { + 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 SENTMSG4"); - 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 enter_state_sentmsg5(struct site *st) +/* msg7 tells our peer that we're about to forget our key */ +static bool_t send_msg7(struct site *st,string_t reason) { - state_assert(st,st->state==SITE_SENTMSG3); - slog(st,LOG_STATE,"entering state SENTMSG5"); - BUF_FREE(&st->buffer); /* Free message 3 */ - - if (generate_msg5(st) && send_msg(st)) { - st->state=SITE_SENTMSG5; - return True; - } - slog(st,LOG_ERROR,"error entering state SENTMSG5"); - st->buffer.free=False; - enter_state_wait(st); - - return False; -} + string_t transform_err; -static bool_t send_msg6(struct site *st) -{ - 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); + 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; } @@ -931,7 +940,6 @@ static void site_afterpoll(void *sst, struct pollfd *fds, int nfds, 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); @@ -943,18 +951,14 @@ static void site_afterpoll(void *sst, struct pollfd *fds, int nfds, } } 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; @@ -978,12 +982,15 @@ static void site_outgoing(void *sst, void *cid, struct buffer_if *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 @@ -995,25 +1002,24 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, 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. */ @@ -1027,7 +1033,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, "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)"); @@ -1045,10 +1051,19 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, 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; @@ -1062,7 +1077,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, 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"); } @@ -1072,7 +1087,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, 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"); } @@ -1082,7 +1097,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, 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"); } @@ -1093,11 +1108,11 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, 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"); } @@ -1113,10 +1128,6 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, 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); @@ -1136,13 +1147,20 @@ static void site_control(void *vst, bool_t run) 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) { struct site *st; item_t *item; dict_t *dict; - uint32_t netlink_options; st=safe_malloc(sizeof(*st),"site_apply"); @@ -1171,7 +1189,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, 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); @@ -1182,8 +1200,6 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, if (st->address) st->remoteport=dict_read_number(dict,"port",True,"site",loc,0); else st->remoteport=0; - dict_read_subnet_list(dict, "networks", True, "site", loc, - &st->remotenets); st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc); st->transform= @@ -1210,15 +1226,11 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, 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"); - netlink_options=string_list_to_word(dict_lookup(dict,"netlink-options"), - netlink_option_table,"site"); - st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5, "site_apply"); sprintf(st->tunname,"%s<->%s",st->localname,st->remotename); @@ -1249,18 +1261,11 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, 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, - netlink_options, 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); @@ -1268,6 +1273,8 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, enter_state_stop(st); + add_hook(PHASE_SHUTDOWN,site_phase_hook,st); + return new_closure(&st->cl); }