2 * curvetun - the cipherspace wormhole creator
3 * Part of the netsniff-ng project
4 * Copyright 2011 Daniel Borkmann <daniel@netsniff-ng.org>,
5 * Subject to the GPL, version 2.
20 #include <netinet/in.h>
21 #include <netinet/tcp.h>
22 #include <netinet/udp.h>
24 #include <sys/types.h>
25 #include <sys/socket.h>
27 #include <sys/epoll.h>
28 #include <arpa/inet.h>
29 #include <linux/if_tun.h>
42 #include "curvetun_mgmt.h"
54 struct worker_struct
{
58 struct parent_info parent
;
59 int (*handler
)(int fd
, const struct worker_struct
*ws
,
60 char *buff
, size_t len
);
61 struct curve25519_struct
*c
;
64 static struct worker_struct
*threadpool
= NULL
;
66 static int auth_log
= 1;
68 extern volatile sig_atomic_t sigint
;
70 static int handler_udp_tun_to_net(int fd
, const struct worker_struct
*ws
,
71 char *buff
, size_t len
) __pure
;
72 static int handler_udp_net_to_tun(int fd
, const struct worker_struct
*ws
,
73 char *buff
, size_t len
) __pure
;
74 static int handler_udp(int fd
, const struct worker_struct
*ws
,
75 char *buff
, size_t len
) __pure
;
76 static int handler_tcp_tun_to_net(int fd
, const struct worker_struct
*ws
,
77 char *buff
, size_t len
) __pure
;
78 static int handler_tcp_net_to_tun(int fd
, const struct worker_struct
*ws
,
79 char *buff
, size_t len
) __pure
;
80 static int handler_tcp(int fd
, const struct worker_struct
*ws
,
81 char *buff
, size_t len
) __pure
;
82 ssize_t
handler_tcp_read(int fd
, char *buff
, size_t len
);
83 static void *worker(void *self
) __pure
;
85 static int handler_udp_tun_to_net(int fd
, const struct worker_struct
*ws
,
86 char *buff
, size_t len
)
90 ssize_t rlen
, err
, clen
;
92 struct curve25519_proto
*p
;
93 struct sockaddr_storage naddr
;
95 size_t off
= sizeof(struct ct_proto
) + crypto_box_zerobytes
;
97 if (!buff
|| len
<= off
)
100 memset(buff
, 0, len
);
101 while ((rlen
= read(fd
, buff
+ off
, len
- off
)) > 0) {
102 dfd
= -1; nlen
= 0; p
= NULL
;
104 memset(&naddr
, 0, sizeof(naddr
));
106 hdr
= (struct ct_proto
*) buff
;
107 memset(hdr
, 0, sizeof(*hdr
));
110 trie_addr_lookup(buff
+ off
, rlen
, ws
->parent
.ipv4
, &dfd
, &naddr
,
112 if (unlikely(dfd
< 0 || nlen
== 0)) {
113 memset(buff
, 0, len
);
117 err
= get_user_by_sockaddr(&naddr
, nlen
, &p
);
118 if (unlikely(err
|| !p
)) {
119 memset(buff
, 0, len
);
123 clen
= curve25519_encode(ws
->c
, p
, (unsigned char *) (buff
+ off
-
124 crypto_box_zerobytes
), (rlen
+
125 crypto_box_zerobytes
), (unsigned char **)
127 if (unlikely(clen
<= 0)) {
128 memset(buff
, 0, len
);
132 hdr
->payload
= htons((uint16_t) clen
);
136 sendto(dfd
, hdr
, sizeof(struct ct_proto
), 0, (struct sockaddr
*)
138 sendto(dfd
, cbuff
, clen
, 0, (struct sockaddr
*) &naddr
, nlen
);
142 memset(buff
, 0, len
);
148 static void handler_udp_notify_close(int fd
, struct sockaddr_storage
*addr
)
152 memset(&hdr
, 0, sizeof(hdr
));
153 hdr
.flags
|= PROTO_FLAG_EXIT
;
156 sendto(fd
, &hdr
, sizeof(hdr
), 0, (struct sockaddr
*) addr
,
160 static int handler_udp_net_to_tun(int fd
, const struct worker_struct
*ws
,
161 char *buff
, size_t len
)
165 ssize_t rlen
, err
, clen
;
166 struct ct_proto
*hdr
;
167 struct curve25519_proto
*p
;
168 struct sockaddr_storage naddr
;
169 socklen_t nlen
= sizeof(naddr
);
174 memset(&naddr
, 0, sizeof(naddr
));
175 while ((rlen
= recvfrom(fd
, buff
, len
, 0, (struct sockaddr
*) &naddr
,
179 hdr
= (struct ct_proto
*) buff
;
181 if (unlikely(rlen
< sizeof(struct ct_proto
)))
183 if (unlikely(rlen
- sizeof(*hdr
) != ntohs(hdr
->payload
)))
185 if (unlikely(ntohs(hdr
->payload
) == 0))
187 if (hdr
->flags
& PROTO_FLAG_EXIT
) {
189 remove_user_by_sockaddr(&naddr
, nlen
);
190 trie_addr_remove_addr(&naddr
, nlen
);
191 handler_udp_notify_close(fd
, &naddr
);
195 if (hdr
->flags
& PROTO_FLAG_INIT
) {
196 syslog_maybe(auth_log
, LOG_INFO
, "Got initial userhash "
197 "from remote end!\n");
199 if (unlikely(rlen
- sizeof(*hdr
) <
200 sizeof(struct username_struct
)))
203 err
= try_register_user_by_sockaddr(ws
->c
,
204 buff
+ sizeof(struct ct_proto
),
205 rlen
- sizeof(struct ct_proto
),
206 &naddr
, nlen
, auth_log
);
213 err
= get_user_by_sockaddr(&naddr
, nlen
, &p
);
214 if (unlikely(err
|| !p
))
217 clen
= curve25519_decode(ws
->c
, p
, (unsigned char *) buff
+
218 sizeof(struct ct_proto
),
219 rlen
- sizeof(struct ct_proto
),
220 (unsigned char **) &cbuff
, NULL
);
221 if (unlikely(clen
<= 0))
224 cbuff
+= crypto_box_zerobytes
;
225 clen
-= crypto_box_zerobytes
;
227 err
= trie_addr_maybe_update(cbuff
, clen
, ws
->parent
.ipv4
,
232 err
= write(ws
->parent
.tunfd
, cbuff
, clen
);
234 nlen
= sizeof(naddr
);
235 memset(&naddr
, 0, sizeof(naddr
));
241 static int handler_udp(int fd
, const struct worker_struct
*ws
,
242 char *buff
, size_t len
)
246 if (fd
== ws
->parent
.tunfd
)
247 ret
= handler_udp_tun_to_net(fd
, ws
, buff
, len
);
249 ret
= handler_udp_net_to_tun(fd
, ws
, buff
, len
);
254 static int handler_tcp_tun_to_net(int fd
, const struct worker_struct
*ws
,
255 char *buff
, size_t len
)
259 ssize_t rlen
, err
, clen
;
260 struct ct_proto
*hdr
;
261 struct curve25519_proto
*p
;
263 size_t off
= sizeof(struct ct_proto
) + crypto_box_zerobytes
;
265 if (!buff
|| len
<= off
)
268 memset(buff
, 0, len
);
269 while ((rlen
= read(fd
, buff
+ off
, len
- off
)) > 0) {
272 hdr
= (struct ct_proto
*) buff
;
273 memset(hdr
, 0, sizeof(*hdr
));
276 trie_addr_lookup(buff
+ off
, rlen
, ws
->parent
.ipv4
, &dfd
, NULL
,
278 if (unlikely(dfd
< 0)) {
279 memset(buff
, 0, len
);
283 err
= get_user_by_socket(dfd
, &p
);
284 if (unlikely(err
|| !p
)) {
285 memset(buff
, 0, len
);
289 clen
= curve25519_encode(ws
->c
, p
, (unsigned char *) (buff
+ off
-
290 crypto_box_zerobytes
), (rlen
+
291 crypto_box_zerobytes
), (unsigned char **)
293 if (unlikely(clen
<= 0)) {
294 memset(buff
, 0, len
);
298 hdr
->payload
= htons((uint16_t) clen
);
302 write_exact(dfd
, hdr
, sizeof(struct ct_proto
), 0);
303 write_exact(dfd
, cbuff
, clen
, 0);
307 memset(buff
, 0, len
);
313 ssize_t
handler_tcp_read(int fd
, char *buff
, size_t len
)
316 struct ct_proto
*hdr
= (struct ct_proto
*) buff
;
321 /* May exit on EAGAIN if 0 Byte read */
322 rlen
= read_exact(fd
, buff
, sizeof(struct ct_proto
), 1);
325 if (unlikely(ntohs(hdr
->payload
) > len
- sizeof(struct ct_proto
))) {
327 return 1; /* Force server to close connection */
330 /* May not exit on EAGAIN if 0 Byte read */
331 rlen
= read_exact(fd
, buff
+ sizeof(struct ct_proto
),
332 ntohs(hdr
->payload
), 0);
336 return sizeof(struct ct_proto
) + rlen
;
339 static void handler_tcp_notify_close(int fd
)
343 memset(&hdr
, 0, sizeof(hdr
));
344 hdr
.flags
|= PROTO_FLAG_EXIT
;
347 if (write(fd
, &hdr
, sizeof(hdr
))) { ; }
350 static int handler_tcp_net_to_tun(int fd
, const struct worker_struct
*ws
,
351 char *buff
, size_t len
)
353 int keep
= 1, count
= 0;
355 ssize_t rlen
, err
, clen
;
356 struct ct_proto
*hdr
;
357 struct curve25519_proto
*p
;
362 while ((rlen
= handler_tcp_read(fd
, buff
, len
)) > 0) {
365 hdr
= (struct ct_proto
*) buff
;
367 if (unlikely(rlen
< sizeof(struct ct_proto
)))
369 if (unlikely(rlen
- sizeof(*hdr
) != ntohs(hdr
->payload
)))
371 if (unlikely(ntohs(hdr
->payload
) == 0))
373 if (hdr
->flags
& PROTO_FLAG_EXIT
) {
375 remove_user_by_socket(fd
);
376 trie_addr_remove(fd
);
377 handler_tcp_notify_close(fd
);
378 rlen
= write(ws
->parent
.efd
, &fd
, sizeof(fd
));
383 if (hdr
->flags
& PROTO_FLAG_INIT
) {
384 syslog_maybe(auth_log
, LOG_INFO
, "Got initial userhash "
385 "from remote end!\n");
387 if (unlikely(rlen
- sizeof(*hdr
) <
388 sizeof(struct username_struct
)))
391 err
= try_register_user_by_socket(ws
->c
,
392 buff
+ sizeof(struct ct_proto
),
393 rlen
- sizeof(struct ct_proto
),
401 err
= get_user_by_socket(fd
, &p
);
402 if (unlikely(err
|| !p
))
405 clen
= curve25519_decode(ws
->c
, p
, (unsigned char *) buff
+
406 sizeof(struct ct_proto
),
407 rlen
- sizeof(struct ct_proto
),
408 (unsigned char **) &cbuff
, NULL
);
409 if (unlikely(clen
<= 0))
412 cbuff
+= crypto_box_zerobytes
;
413 clen
-= crypto_box_zerobytes
;
415 err
= trie_addr_maybe_update(cbuff
, clen
, ws
->parent
.ipv4
,
420 err
= write(ws
->parent
.tunfd
, cbuff
, clen
);
424 write_exact(ws
->efd
[1], &fd
, sizeof(fd
), 1);
425 /* Read later next data and let others process */
433 static int handler_tcp(int fd
, const struct worker_struct
*ws
,
434 char *buff
, size_t len
)
438 if (fd
== ws
->parent
.tunfd
)
439 ret
= handler_tcp_tun_to_net(fd
, ws
, buff
, len
);
441 ret
= handler_tcp_net_to_tun(fd
, ws
, buff
, len
);
446 static void *worker(void *self
)
450 size_t blen
= TUNBUFF_SIZ
; //FIXME
451 struct worker_struct
*ws
= self
;
458 ws
->c
= curve25519_tfm_alloc();
459 buff
= xmalloc_aligned(blen
, 64);
461 syslog(LOG_INFO
, "curvetun thread on CPU%u up!\n", ws
->cpu
);
463 pthread_cleanup_push(curve25519_tfm_free_void
, ws
->c
);
464 pthread_cleanup_push(xfree_func
, buff
);
466 while (likely(!sigint
)) {
468 if ((fds
.revents
& POLLIN
) != POLLIN
)
471 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE
, &old_state
);
473 while ((ret
= read_exact(ws
->efd
[0], &fd
, sizeof(fd
), 1)) > 0) {
474 if (ret
!= sizeof(fd
)) {
479 ret
= ws
->handler(fd
, ws
, buff
, blen
);
481 write_exact(ws
->parent
.refd
, &fd
, sizeof(fd
), 1);
484 pthread_setcancelstate(old_state
, NULL
);
487 syslog(LOG_INFO
, "curvetun thread on CPU%u down!\n", ws
->cpu
);
489 pthread_cleanup_pop(1);
490 pthread_cleanup_pop(1);
492 pthread_exit((void *) ((long) ws
->cpu
));
495 static void thread_spawn_or_panic(unsigned int cpus
, int efd
, int refd
,
496 int tunfd
, int ipv4
, int udp
)
500 unsigned int threads
;
502 threads
= cpus
* THREADS_PER_CPU
;
504 for (i
= 0; i
< threads
; ++i
) {
506 threadpool
[i
].cpu
= i
% cpus
;
507 CPU_SET(threadpool
[i
].cpu
, &cpuset
);
509 ret
= pipe2(threadpool
[i
].efd
, O_NONBLOCK
);
511 syslog_panic("Cannot create event socket!\n");
513 threadpool
[i
].c
= xmalloc_aligned(sizeof(*threadpool
[i
].c
), 64);
514 threadpool
[i
].parent
.efd
= efd
;
515 threadpool
[i
].parent
.refd
= refd
;
516 threadpool
[i
].parent
.tunfd
= tunfd
;
517 threadpool
[i
].parent
.ipv4
= ipv4
;
518 threadpool
[i
].parent
.udp
= udp
;
519 threadpool
[i
].handler
= udp
? handler_udp
: handler_tcp
;
521 ret
= pthread_create(&threadpool
[i
].trid
, NULL
,
522 worker
, &threadpool
[i
]);
524 syslog_panic("Thread creation failed!\n");
526 ret
= pthread_setaffinity_np(threadpool
[i
].trid
,
527 sizeof(cpuset
), &cpuset
);
529 syslog_panic("Thread CPU migration failed!\n");
531 pthread_detach(threadpool
[i
].trid
);
537 static void thread_finish(unsigned int cpus
)
540 unsigned int threads
;
542 threads
= cpus
* THREADS_PER_CPU
;
544 for (i
= 0; i
< threads
; ++i
) {
545 while (pthread_join(threadpool
[i
].trid
, NULL
) < 0)
548 close(threadpool
[i
].efd
[0]);
549 close(threadpool
[i
].efd
[1]);
553 int server_main(char *home
, char *dev
, char *port
, int udp
, int ipv4
, int log
)
555 int lfd
= -1, kdpfd
, nfds
, nfd
, curfds
, efd
[2], refd
[2], tunfd
, i
;
556 unsigned int cpus
= 0, threads
, udp_cpu
= 0;
558 struct epoll_event
*events
;
559 struct addrinfo hints
, *ahead
, *ai
;
562 openlog("curvetun", LOG_PID
| LOG_CONS
| LOG_NDELAY
, LOG_DAEMON
);
564 syslog(LOG_INFO
, "curvetun server booting!\n");
565 syslog_maybe(!auth_log
, LOG_INFO
, "curvetun user logging disabled!\n");
567 parse_userfile_and_generate_user_store_or_die(home
);
569 memset(&hints
, 0, sizeof(hints
));
570 hints
.ai_family
= PF_UNSPEC
;
571 hints
.ai_socktype
= udp
? SOCK_DGRAM
: SOCK_STREAM
;
572 hints
.ai_protocol
= udp
? IPPROTO_UDP
: IPPROTO_TCP
;
573 hints
.ai_flags
= AI_PASSIVE
;
575 ret
= getaddrinfo(NULL
, port
, &hints
, &ahead
);
577 syslog_panic("Cannot get address info!\n");
579 for (ai
= ahead
; ai
!= NULL
&& lfd
< 0; ai
= ai
->ai_next
) {
580 lfd
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
583 if (ai
->ai_family
== AF_INET6
) {
585 ret
= set_ipv6_only(lfd
);
595 #endif /* IPV6_V6ONLY */
599 set_mtu_disc_dont(lfd
);
601 ret
= bind(lfd
, ai
->ai_addr
, ai
->ai_addrlen
);
609 ret
= listen(lfd
, 5);
618 ipv4
= (ai
->ai_family
== AF_INET6
? 0 :
619 (ai
->ai_family
== AF_INET
? 1 : -1));
622 syslog_maybe(auth_log
, LOG_INFO
, "curvetun on IPv%d via %s "
623 "on port %s!\n", ai
->ai_family
== AF_INET
? 4 : 6,
624 udp
? "UDP" : "TCP", port
);
625 syslog_maybe(auth_log
, LOG_INFO
, "Allowed overlay proto is "
626 "IPv%d!\n", ipv4
? 4 : 6);
631 if (lfd
< 0 || ipv4
< 0)
632 syslog_panic("Cannot create socket!\n");
634 tunfd
= tun_open_or_die(dev
? dev
: DEVNAME_SERVER
, IFF_TUN
| IFF_NO_PI
);
636 pipe_or_die(efd
, O_NONBLOCK
);
637 pipe_or_die(refd
, O_NONBLOCK
);
639 set_nonblocking(lfd
);
641 events
= xcalloc(MAX_EPOLL_SIZE
, sizeof(*events
));
642 for (i
= 0; i
< MAX_EPOLL_SIZE
; ++i
)
643 events
[i
].data
.fd
= -1;
645 kdpfd
= epoll_create(MAX_EPOLL_SIZE
);
647 syslog_panic("Cannot create socket!\n");
649 set_epoll_descriptor(kdpfd
, EPOLL_CTL_ADD
, lfd
,
650 udp
? EPOLLIN
| EPOLLET
| EPOLLONESHOT
: EPOLLIN
);
651 set_epoll_descriptor(kdpfd
, EPOLL_CTL_ADD
, efd
[0], EPOLLIN
);
652 set_epoll_descriptor(kdpfd
, EPOLL_CTL_ADD
, refd
[0], EPOLLIN
);
653 set_epoll_descriptor(kdpfd
, EPOLL_CTL_ADD
, tunfd
,
654 EPOLLIN
| EPOLLET
| EPOLLONESHOT
);
659 cpus
= get_number_cpus_online();
660 threads
= cpus
* THREADS_PER_CPU
;
661 if (!ispow2(threads
))
662 syslog_panic("Thread number not power of two!\n");
664 threadpool
= xcalloc(threads
, sizeof(*threadpool
));
665 thread_spawn_or_panic(cpus
, efd
[1], refd
[1], tunfd
, ipv4
, udp
);
667 init_cpusched(threads
);
669 register_socket(tunfd
);
670 register_socket(lfd
);
672 syslog(LOG_INFO
, "curvetun up and running!\n");
674 while (likely(!sigint
)) {
675 nfds
= epoll_wait(kdpfd
, events
, curfds
, -1);
677 syslog(LOG_ERR
, "epoll_wait error: %s\n",
682 for (i
= 0; i
< nfds
; ++i
) {
683 if (unlikely(events
[i
].data
.fd
< 0))
686 if (events
[i
].data
.fd
== lfd
&& !udp
) {
688 char hbuff
[256], sbuff
[256];
689 struct sockaddr_storage taddr
;
692 tlen
= sizeof(taddr
);
693 nfd
= accept(lfd
, (struct sockaddr
*) &taddr
,
696 syslog(LOG_ERR
, "accept error: %s\n",
701 if (curfds
+ 1 > MAX_EPOLL_SIZE
) {
708 ncpu
= register_socket(nfd
);
710 memset(hbuff
, 0, sizeof(hbuff
));
711 memset(sbuff
, 0, sizeof(sbuff
));
712 getnameinfo((struct sockaddr
*) &taddr
, tlen
,
713 hbuff
, sizeof(hbuff
),
714 sbuff
, sizeof(sbuff
),
715 NI_NUMERICHOST
| NI_NUMERICSERV
);
717 syslog_maybe(auth_log
, LOG_INFO
, "New connection "
718 "from %s:%s (%d active client connections) - id %d on CPU%d",
719 hbuff
, sbuff
, curfds
-4, nfd
, ncpu
);
721 set_nonblocking(nfd
);
722 set_socket_keepalive(nfd
);
723 set_tcp_nodelay(nfd
);
724 ret
= set_epoll_descriptor2(kdpfd
, EPOLL_CTL_ADD
,
725 nfd
, EPOLLIN
| EPOLLET
| EPOLLONESHOT
);
731 } else if (events
[i
].data
.fd
== refd
[0]) {
734 ret
= read_exact(refd
[0], &fd_one
,
736 if (ret
!= sizeof(fd_one
) || fd_one
<= 0)
739 ret
= set_epoll_descriptor2(kdpfd
, EPOLL_CTL_MOD
,
740 fd_one
, EPOLLIN
| EPOLLET
| EPOLLONESHOT
);
745 } else if (events
[i
].data
.fd
== efd
[0]) {
748 ret
= read_exact(efd
[0], &fd_del
,
750 if (ret
!= sizeof(fd_del
) || fd_del
<= 0)
753 ret
= read(fd_del
, &test
, sizeof(test
));
754 if (ret
< 0 && errno
== EBADF
)
757 ret
= set_epoll_descriptor2(kdpfd
, EPOLL_CTL_DEL
,
766 unregister_socket(fd_del
);
768 syslog_maybe(auth_log
, LOG_INFO
, "Closed connection "
769 "with id %d (%d active client connections remain)\n", fd_del
,
772 int cpu
, fd_work
= events
[i
].data
.fd
;
775 cpu
= socket_to_cpu(fd_work
);
777 udp_cpu
= (udp_cpu
+ 1) & (threads
- 1);
779 write_exact(threadpool
[udp
? udp_cpu
: cpu
].efd
[1],
780 &fd_work
, sizeof(fd_work
), 1);
785 syslog(LOG_INFO
, "curvetun prepare shut down!\n");
799 unregister_socket(lfd
);
800 unregister_socket(tunfd
);
806 destroy_user_store();
808 syslog(LOG_INFO
, "curvetun shut down!\n");