2 * send/receive module for secnet
3 * for multi-route setups */
8 #include "comm-common.h"
15 static comm_sendmsg_fn polypath_sendmsg
;
18 char *name
; /* from malloc */
19 struct udpsocks socks
;
20 bool_t experienced_xmit_noaf
[MAX_AF
+1];
21 LIST_ENTRY(interf
) entry
;
27 const char *const *ifname_pats
;
28 const char *const *monitor_command
;
29 bool_t permit_loopback
;
30 LIST_HEAD(,interf
) interfs
;
31 struct buffer_if lbuf
;
36 #define LG 0, st->uc.cc.cl.description, &st->uc.cc.loc
38 static const char *const default_loopback_ifname_pats
[] = {
41 static const char *const default_ifname_pats
[] = {
42 "!tun*","!tap*","!sl*","!userv*", "*", 0
45 static const char *const default_monitor_command
[] = {
47 DATAROOTDIR
"/secnet/" "polypath-interface-monitor-linux", 0
53 static const char *polypath_addr_to_string(void *commst
,
54 const struct comm_addr
*ca
)
56 static char sbuf
[100];
58 snprintf(sbuf
, sizeof(sbuf
), "polypath:%s",
59 iaddr_to_string(&ca
->ia
));
63 static bool_t
ifname_search_pats(struct polypath
*st
, struct cloc loc
,
64 const char *ifname
, bool_t
*want_io
,
65 const char *const *pats
) {
66 /* Returns True iff we found a list entry, in which case *want_io
67 * is set to the sense of that entry. Otherwise *want_io is set
68 * to the sense of the last entry, or unchanged if there were no pats. */
71 const char *const *pati
;
72 for (pati
=pats
; *pati
; pati
++) {
73 const char *pat
=*pati
;
74 if (*pat
=='!') { *want_io
=False
; pat
++; }
75 else if (*pat
=='+') { *want_io
=True
; pat
++; }
76 else if (*pat
=='*' || isalnum((unsigned char)*pat
)) { *want_io
=True
; }
77 else cfgfatal(loc
,"polypath","invalid interface name pattern `%s'",pat
);
78 int match
=fnmatch(pat
,ifname
,0);
79 if (match
==0) return True
;
80 if (match
!=FNM_NOMATCH
)
81 cfgfatal(loc
,"polypath","fnmatch failed! (pattern `%s')",pat
);
86 static bool_t
ifname_wanted(struct polypath
*st
, struct cloc loc
,
88 bool_t want
=False
; /* pretend an empty cfg ends with !<doesn'tmatch> */
89 if (ifname_search_pats(st
,loc
,ifname
,&want
, st
->ifname_pats
))
91 if (want
) /* last pattern was positive, do not search default */
93 if (!st
->permit_loopback
&&
94 ifname_search_pats(st
,loc
,ifname
,&want
, default_loopback_ifname_pats
))
96 if (ifname_search_pats(st
,loc
,ifname
,&want
, default_ifname_pats
))
101 static int polypath_beforepoll(void *state
, struct pollfd
*fds
, int *nfds_io
,
104 struct polypath
*st
=state
;
105 BEFOREPOLL_WANT_FDS(1);
106 fds
[0].fd
=st
->monitor_fd
;
107 fds
[0].events
=POLLIN
;
111 static inline bool_t
matches32(uint32_t word
, uint32_t prefix
, int prefixlen
)
114 assert(prefixlen
<=32);
115 uint32_t mask
= ~(((uint32_t)1 << (32-prefixlen
)) - 1);
116 assert(!(prefix
& ~mask
));
117 return (word
& mask
) == prefix
;
120 /* These macros expect
121 * bad_fn_type *const bad;
126 #define BAD(m) do{ bad(st,badctx,m,0); goto out; }while(0)
127 #define BADE(m,ev) do{ bad(st,badctx,m,ev); goto out; }while(0)
128 typedef void bad_fn_type(struct polypath
*st
, void *badctx
,
129 const char* m
, int ev
);
131 typedef void polypath_ppml_callback_type(struct polypath
*st
,
132 bad_fn_type
*bad
, void *badctx
,
133 bool_t add
, const char *ifname
, const char *ifaddr
,
134 const union iaddr
*ia
, int fd
/* -1 if none yet */);
136 struct ppml_bad_ctx
{
141 static void ppml_bad(struct polypath
*st
, void *badctx
, const char *m
, int ev
)
143 struct ppml_bad_ctx
*bc
=badctx
;
145 *(bc
->undospace
)=' ';
146 lg_perror(LG
,M_WARNING
,ev
,
147 "error processing polypath state change: %s"
148 " (while processing `%s')",
152 static void polypath_process_monitor_line(struct polypath
*st
, char *orgl
,
153 polypath_ppml_callback_type
*callback
)
154 /* always calls callback with fd==-1 */
156 struct udpcommon
*uc
=&st
->uc
;
158 bad_fn_type (*const bad
)=ppml_bad
;
159 struct ppml_bad_ctx badctx
[1]={{
166 if (c
=='+') add
=True
;
167 else if (c
=='-') add
=False
;
172 if (c
=='4') proto
=AF_INET
;
173 else if (c
=='6') proto
=AF_INET6
;
174 else BAD("bad proto");
176 char *space
=strchr(l
,' ');
177 if (!space
) BAD("no first space");
178 const char *ifname
=space
+1;
180 space
=strchr(ifname
,' ');
181 if (!space
) BAD("no second space");
182 const char *ifaddr
=space
+1;
184 badctx
->undospace
=space
;
188 socklen_t salen
=sizeof(ia
);
189 int r
=adns_text2addr(ifaddr
,uc
->port
, adns_qf_addrlit_ipv4_quadonly
,
192 if (r
) BADE("adns_text2addr",r
);
193 if (ia
.sa
.sa_family
!=proto
) BAD("address family mismatch");
195 #define DONT(m) do{ \
197 lg_perror(LG,M_INFO,0,"ignoring %s [%s]: %s",ifname,ifaddr,m); \
201 if (!ifname_wanted(st
,st
->uc
.cc
.loc
,ifname
))
202 DONT("unwanted interface name");
204 switch (ia
.sa
.sa_family
) {
206 const struct in6_addr
*i6
=&ia
.sin6
.sin6_addr
;
207 #define DONTKIND(X,m) \
208 if (IN6_IS_ADDR_##X(i6)) DONT("IPv6 address is " m)
209 DONTKIND(UNSPECIFIED
, "unspecified");
210 DONTKIND(MULTICAST
, "multicast" );
211 DONTKIND(LINKLOCAL
, "link local" );
212 DONTKIND(SITELOCAL
, "site local" );
213 DONTKIND(V4MAPPED
, "v4-mapped" );
214 if (!st
->permit_loopback
)
215 DONTKIND(LOOPBACK
, "loopback" );
217 #define DONTMASK(w7x,w6x,prefixlen,m) \
218 if (matches32(get_uint32(i6->s6_addr), \
219 ((uint32_t)0x##w7x << 16) | (uint32_t)0x##w6x, \
221 DONT("IPv6 address is " m)
222 DONTMASK( 100, 0, 8, "Discard-Only (RFC6666)");
223 DONTMASK(2001, 0, 23, "in IETF protocol block (RFC2928)");
228 const uint32_t i4
=htonl(ia
.sin
.sin_addr
.s_addr
);
229 if (i4
==INADDR_ANY
) DONT("IPv4 address is any/unspecified");
230 if (i4
==INADDR_BROADCAST
) DONT("IPv4 address is all hosts broadcast");
231 #define DONTMASK(b3,b2,b1,b0,prefixlen,m) do{ \
232 const uint8_t prefixbytes[4] = { (b3),(b2),(b1),(b0) }; \
233 if (matches32(i4,get_uint32(prefixbytes),prefixlen)) \
234 DONT("IPv4 address is " m); \
236 DONTMASK(169,254,0,0, 16, "link local");
237 DONTMASK(224, 0,0,0, 4, "multicast");
238 DONTMASK(192, 0,0,0, 24, "in IETF protocol block (RFC6890)");
239 DONTMASK(240, 0,0,0, 4, "in reserved addressing block (RFC1112)");
240 if (!st
->permit_loopback
)
241 DONTMASK(127, 0,0,0, 8, "loopback");
252 callback(st
, bad
,badctx
, add
,ifname
,ifaddr
,&ia
,-1);
257 static void dump_pria(struct polypath
*st
, const char *ifname
)
259 #ifdef POLYPATH_DEBUG
260 struct interf
*interf
;
262 lg_perror(LG
,M_DEBUG
,0, "polypath record ifaddr `%s'",ifname
);
263 LIST_FOREACH(interf
, &st
->interfs
, entry
) {
264 lg_perror(LG
,M_DEBUG
,0, " polypath interface `%s', nsocks=%d",
265 interf
->name
, interf
->socks
.n_socks
);
267 for (i
=0; i
<interf
->socks
.n_socks
; i
++) {
268 struct udpsock
*us
=&interf
->socks
.socks
[i
];
269 lg_perror(LG
,M_DEBUG
,0, " polypath sock fd=%d addr=%s",
270 us
->fd
, iaddr_to_string(&us
->addr
));
276 static bool_t
polypath_make_socket(struct polypath
*st
,
277 bad_fn_type
*bad
, void *badctx
,
278 struct udpsock
*us
, const char *ifname
)
279 /* on error exit has called bad; might leave us->fd as -1 */
283 bool_t ok
=udp_make_socket(&st
->uc
,us
,M_WARNING
);
284 if (!ok
) BAD("unable to set up socket");
285 int r
=setsockopt(us
->fd
,SOL_SOCKET
,SO_BINDTODEVICE
,
286 ifname
,strlen(ifname
)+1);
287 if (r
) BADE("setsockopt(,,SO_BINDTODEVICE,)",errno
);
294 static void polypath_record_ifaddr(struct polypath
*st
,
295 bad_fn_type
*bad
, void *badctx
,
296 bool_t add
, const char *ifname
,
298 const union iaddr
*ia
, int fd
)
300 struct udpcommon
*uc
=&st
->uc
;
301 struct interf
*interf
=0;
302 struct udpsock
*us
=0;
304 dump_pria(st
,ifname
);
307 LIST_FOREACH(interf
,&st
->interfs
,entry
) {
308 if (!strcmp(interf
->name
,ifname
))
313 if (n_ifs
==st
->max_interfs
) BAD("too many interfaces");
314 interf
=malloc(sizeof(*interf
));
315 if (!interf
) BADE("malloc for new interface",errno
);
317 interf
->socks
.n_socks
=0;
318 FILLZERO(interf
->experienced_xmit_noaf
);
319 LIST_INSERT_HEAD(&st
->interfs
,interf
,entry
);
320 udp_socks_register(&st
->uc
,&interf
->socks
);
321 interf
->name
=strdup(ifname
);
322 if (!interf
->name
) BADE("strdup interface name",errno
);
326 if (interf
->socks
.n_socks
== UDP_MAX_SOCKETS
)
327 BAD("too many addresses on this interface");
328 struct udpsock
*us
=&interf
->socks
.socks
[interf
->socks
.n_socks
];
330 COPY_OBJ(us
->addr
,*ia
);
332 bool_t ok
=polypath_make_socket(st
,bad
,badctx
, us
,ifname
);
335 FILLZERO(us
->experienced
);
339 interf
->socks
.n_socks
++;
340 us
=0; /* do not destroy this socket during `out' */
341 lg_perror(LG
,M_INFO
,0,"using %s %s",ifname
,ifaddr
);
344 for (i
=0; i
<interf
->socks
.n_socks
; i
++)
345 if (!memcmp(&interf
->socks
.socks
[i
].addr
,ia
,sizeof(*ia
)))
346 goto address_remove_found
;
347 BAD("address to remove not found");
348 address_remove_found
:
349 lg_perror(LG
,M_INFO
,0,"removed %s %s",ifname
,ifaddr
);
350 udp_destroy_socket(&st
->uc
,&interf
->socks
.socks
[i
]);
351 interf
->socks
.socks
[i
]=
352 interf
->socks
.socks
[--interf
->socks
.n_socks
];
357 udp_destroy_socket(uc
,us
);
360 if (interf
&& !interf
->socks
.n_socks
) {
361 udp_socks_deregister(&st
->uc
,&interf
->socks
);
362 LIST_REMOVE(interf
,entry
);
370 static void polypath_afterpoll(void *state
, struct pollfd
*fds
, int nfds
)
372 struct polypath
*st
=state
;
373 enum async_linebuf_result alr
;
379 while ((alr
=async_linebuf_read(fds
,&st
->lbuf
,&emsg
)) == async_linebuf_ok
)
380 polypath_process_monitor_line(st
,st
->lbuf
.base
,
381 polypath_record_ifaddr
);
383 if (alr
==async_linebuf_nothing
)
386 assert(st
->monitor_pid
);
388 pid_t gotpid
=waitpid(st
->monitor_pid
,&status
,WNOHANG
);
389 if (gotpid
==st
->monitor_pid
) {
391 lg_exitstatus(LG
,M_FATAL
,status
,"interface monitor");
393 lg_perror(LG
,M_ERR
,errno
,"unable to reap interface monitor");
397 if (alr
==async_linebuf_eof
)
398 lg_perror(LG
,M_FATAL
,0,"unexpected EOF from interface monitor");
400 lg_perror(LG
,M_FATAL
,0,"bad output from interface monitor: %s",emsg
);
402 assert(!"not reached");
405 /* Actual udp packet sending work */
406 static bool_t
polypath_sendmsg(void *commst
, struct buffer_if
*buf
,
407 const struct comm_addr
*dest
)
409 struct polypath
*st
=commst
;
410 struct interf
*interf
;
411 bool_t allreasonable
=True
;
412 int af
=dest
->ia
.sa
.sa_family
;
414 LIST_FOREACH(interf
,&st
->interfs
,entry
) {
416 bool_t attempted
=False
, reasonable
=False
;
417 for (i
=0; i
<interf
->socks
.n_socks
; i
++) {
418 struct udpsock
*us
=&interf
->socks
.socks
[i
];
419 if (af
!= us
->addr
.sa
.sa_family
)
422 int r
=sendto(us
->fd
,buf
->start
,buf
->size
,
423 0,&dest
->ia
.sa
,iaddr_socklen(&dest
->ia
));
424 udp_sock_experienced(0,&st
->uc
, interf
->name
,us
,
430 if (!(errno
==EAFNOSUPPORT
|| errno
==ENETUNREACH
))
432 lg_perror(LG
,M_DEBUG
,errno
,"%s [%s] xmit %"PRIu32
" bytes to %s",
433 interf
->name
,iaddr_to_string(&us
->addr
),
434 buf
->size
,iaddr_to_string(&dest
->ia
));
437 if (!interf
->experienced_xmit_noaf
[af
]++)
438 lg_perror(LG
,M_WARNING
,0,
439 "%s has no suitable address to transmit %s",
440 interf
->name
, af_name(af
));
441 allreasonable
*= reasonable
;
443 return allreasonable
;
446 static void polypath_phase_startmonitor(void *sst
, uint32_t newphase
)
448 struct polypath
*st
=sst
;
451 assert(!st
->monitor_pid
);
452 assert(st
->monitor_fd
<0);
460 execvp(st
->monitor_command
[0],(char**)st
->monitor_command
);
461 fprintf(stderr
,"secnet: cannot execute %s: %s\n",
462 st
->monitor_command
[0], strerror(errno
));
466 fatal_perror("%s: failed to fork for interface monitor",
467 st
->uc
.cc
.cl
.description
);
471 st
->monitor_fd
=pfds
[0];
472 setnonblock(st
->monitor_fd
);
474 register_for_poll(st
,polypath_beforepoll
,polypath_afterpoll
,"polypath");
477 static void polypath_phase_shutdown(void *sst
, uint32_t newphase
)
479 struct polypath
*st
=sst
;
480 if (st
->monitor_pid
) {
481 assert(st
->monitor_pid
>0);
482 kill(st
->monitor_pid
,SIGTERM
);
489 static list_t
*polypath_apply(closure_t
*self
, struct cloc loc
,
490 dict_t
*context
, list_t
*args
)
494 COMM_APPLY(st
,&st
->uc
.cc
,polypath_
,"polypath",loc
);
495 COMM_APPLY_STANDARD(st
,&st
->uc
.cc
,"polypath",args
);
496 UDP_APPLY_STANDARD(st
,&st
->uc
,"polypath");
498 struct udpcommon
*uc
=&st
->uc
;
499 struct commcommon
*cc
=&uc
->cc
;
501 st
->max_interfs
=dict_read_number(d
,"max-interfaces",False
,"polypath",loc
,3);
503 st
->ifname_pats
=dict_read_string_array(d
,"interfaces",False
,"polypath",
505 st
->permit_loopback
=0; /* ifname_wanted reads this */
506 ifname_wanted(st
,st
->uc
.cc
.loc
," "); /* try to check each pattern */
508 st
->monitor_command
=dict_read_string_array(d
,"monitor-command",False
,
509 "polypath",cc
->loc
, default_monitor_command
);
510 if (!st
->monitor_command
[0])
511 cfgfatal(loc
,"polypath","no polypath interface monitor-command"
512 " (polypath unsupported on this platform?)\n");
514 st
->permit_loopback
=dict_read_bool(d
,"permit-loopback",False
,
515 "polypath",cc
->loc
,False
);
517 LIST_INIT(&st
->interfs
);
518 buffer_new(&st
->lbuf
,ADNS_ADDR2TEXT_BUFLEN
+100);
519 BUF_ALLOC(&st
->lbuf
,"polypath lbuf");
524 add_hook(PHASE_RUN
, polypath_phase_startmonitor
,st
);
525 add_hook(PHASE_SHUTDOWN
, polypath_phase_shutdown
, st
);
527 return new_closure(&cc
->cl
);
530 #endif /* CONFIG_IPV6 */
532 void polypath_module(dict_t
*dict
)
535 add_closure(dict
,"polypath",polypath_apply
);
536 #endif /* CONFIG_IPV6 */