Commit | Line | Data |
---|---|---|
ce5c098f IJ |
1 | /* polypath |
2 | * send/receive module for secnet | |
3 | * for multi-route setups */ | |
4 | ||
5 | #include "secnet.h" | |
6 | #include "util.h" | |
7 | #include "unaligned.h" | |
8 | #include "comm-common.h" | |
9 | ||
10 | #include <adns.h> | |
11 | #include <ctype.h> | |
12 | ||
13 | #ifdef CONFIG_IPV6 | |
14 | ||
15 | static comm_sendmsg_fn polypath_sendmsg; | |
16 | ||
17 | struct interf { | |
18 | char *name; /* from malloc */ | |
19 | struct udpsocks socks; | |
20 | bool_t experienced_xmit_noaf[MAX_AF+1]; | |
21 | LIST_ENTRY(interf) entry; | |
22 | }; | |
23 | ||
24 | struct polypath { | |
25 | struct udpcommon uc; | |
26 | int max_interfs; | |
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; | |
32 | int monitor_fd; | |
33 | pid_t monitor_pid; | |
34 | }; | |
35 | ||
36 | #define LG 0, st->uc.cc.cl.description, &st->uc.cc.loc | |
37 | ||
38 | static const char *const default_loopback_ifname_pats[] = { | |
39 | "!lo", 0 | |
40 | }; | |
41 | static const char *const default_ifname_pats[] = { | |
42 | "!tun*","!tap*","!sl*","!userv*", "*", 0 | |
43 | }; | |
44 | ||
45 | static const char *const default_monitor_command[] = { | |
e61a41a4 IJ |
46 | #if __linux__ |
47 | DATAROOTDIR "/secnet/" "polypath-interface-monitor-linux", 0 | |
48 | #else | |
ce5c098f | 49 | 0 |
e61a41a4 | 50 | #endif |
ce5c098f IJ |
51 | }; |
52 | ||
53 | static const char *polypath_addr_to_string(void *commst, | |
54 | const struct comm_addr *ca) | |
55 | { | |
56 | static char sbuf[100]; | |
57 | ||
58 | snprintf(sbuf, sizeof(sbuf), "polypath:%s", | |
59 | iaddr_to_string(&ca->ia)); | |
60 | return sbuf; | |
61 | } | |
62 | ||
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. */ | |
69 | if (!pats) | |
70 | return False; | |
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); | |
82 | } | |
83 | return False; | |
84 | } | |
85 | ||
86 | static bool_t ifname_wanted(struct polypath *st, struct cloc loc, | |
87 | const char *ifname) { | |
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)) | |
90 | return want; | |
91 | if (want) /* last pattern was positive, do not search default */ | |
92 | return False; | |
93 | if (!st->permit_loopback && | |
94 | ifname_search_pats(st,loc,ifname,&want, default_loopback_ifname_pats)) | |
95 | return want; | |
96 | if (ifname_search_pats(st,loc,ifname,&want, default_ifname_pats)) | |
97 | return want; | |
98 | abort(); | |
99 | } | |
100 | ||
101 | static int polypath_beforepoll(void *state, struct pollfd *fds, int *nfds_io, | |
102 | int *timeout_io) | |
103 | { | |
104 | struct polypath *st=state; | |
105 | BEFOREPOLL_WANT_FDS(1); | |
106 | fds[0].fd=st->monitor_fd; | |
107 | fds[0].events=POLLIN; | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static void dump_ppml(struct polypath *st, const char *orgl) | |
112 | { | |
113 | #ifdef POLYPATH_DEBUG | |
114 | struct interf *interf; | |
115 | if (orgl) | |
116 | lg_perror(LG,M_DEBUG,0, "polypath monitor line `%s'",orgl); | |
117 | LIST_FOREACH(interf, &st->interfs, entry) { | |
118 | lg_perror(LG,M_DEBUG,0, " polypath interface `%s', nsocks=%d", | |
119 | interf->name, interf->socks.n_socks); | |
120 | int i; | |
121 | for (i=0; i<interf->socks.n_socks; i++) { | |
122 | struct udpsock *us=&interf->socks.socks[i]; | |
123 | lg_perror(LG,M_DEBUG,0, " polypath sock fd=%d addr=%s", | |
124 | us->fd, iaddr_to_string(&us->addr)); | |
125 | } | |
126 | } | |
127 | #endif | |
128 | } | |
129 | ||
130 | static void bad(struct polypath *st, char *l, char *undospace, | |
131 | const char *m, int ev) | |
132 | { | |
133 | if (undospace) | |
134 | *undospace=' '; | |
135 | lg_perror(LG,M_WARNING,ev, | |
136 | "error processing polypath state change: %s" | |
137 | " (while processing `%s')", | |
138 | m,l); | |
139 | } | |
140 | ||
141 | static inline bool_t matches32(uint32_t word, uint32_t prefix, int prefixlen) | |
142 | { | |
143 | assert(prefixlen>0); | |
144 | assert(prefixlen<=32); | |
145 | uint32_t mask = ~(((uint32_t)1 << (32-prefixlen)) - 1); | |
146 | assert(!(prefix & ~mask)); | |
147 | return (word & mask) == prefix; | |
148 | } | |
149 | ||
150 | static void polypath_process_monitor_line(struct polypath *st, char *orgl) | |
151 | { | |
152 | struct interf *interf=0; | |
153 | struct udpcommon *uc=&st->uc; | |
154 | char *undospace=0; | |
155 | char *l=orgl; | |
156 | struct udpsock *us=0; | |
157 | ||
158 | dump_ppml(st,orgl); | |
159 | ||
160 | #define BAD(m) do{ bad(st,orgl,undospace,m,0); goto out; }while(0) | |
161 | #define BADE(m,ev) do{ bad(st,orgl,undospace,m,ev); goto out; }while(0) | |
162 | ||
163 | bool_t add; | |
164 | int c=*l++; | |
165 | if (c=='+') add=True; | |
166 | else if (c=='-') add=False; | |
167 | else BAD("bad +/-"); | |
168 | ||
169 | int proto; | |
170 | c=*l++; | |
171 | if (c=='4') proto=AF_INET; | |
172 | else if (c=='6') proto=AF_INET6; | |
173 | else BAD("bad proto"); | |
174 | ||
175 | char *space=strchr(l,' '); | |
176 | if (!space) BAD("no first space"); | |
177 | const char *ifname=space+1; | |
178 | ||
179 | space=strchr(ifname,' '); | |
180 | if (!space) BAD("no second space"); | |
181 | const char *ifaddr=space+1; | |
182 | *space=0; | |
183 | undospace=space; | |
184 | ||
185 | union iaddr ia; | |
186 | FILLZERO(ia); | |
187 | socklen_t salen=sizeof(ia); | |
188 | int r=adns_text2addr(ifaddr,uc->port, adns_qf_addrlit_ipv4_quadonly, | |
189 | &ia.sa, &salen); | |
190 | assert(r!=ENOSPC); | |
191 | if (r) BADE("adns_text2addr",r); | |
192 | if (ia.sa.sa_family!=proto) BAD("address family mismatch"); | |
193 | ||
194 | #define DONT(m) do{ \ | |
195 | if (add) \ | |
196 | lg_perror(LG,M_INFO,0,"ignoring %s [%s]: %s",ifname,ifaddr,m); \ | |
197 | goto out; \ | |
198 | }while(0) | |
199 | ||
200 | if (!ifname_wanted(st,st->uc.cc.loc,ifname)) | |
201 | DONT("unwanted interface name"); | |
202 | ||
203 | switch (ia.sa.sa_family) { | |
204 | case AF_INET6: { | |
205 | const struct in6_addr *i6=&ia.sin6.sin6_addr; | |
206 | #define DONTKIND(X,m) \ | |
207 | if (IN6_IS_ADDR_##X(i6)) DONT("IPv6 address is " m) | |
208 | DONTKIND(UNSPECIFIED, "unspecified"); | |
209 | DONTKIND(MULTICAST , "multicast" ); | |
210 | DONTKIND(LINKLOCAL , "link local" ); | |
211 | DONTKIND(SITELOCAL , "site local" ); | |
212 | DONTKIND(V4MAPPED , "v4-mapped" ); | |
213 | if (!st->permit_loopback) | |
214 | DONTKIND(LOOPBACK , "loopback" ); | |
215 | #undef DONTKIND | |
216 | #define DONTMASK(w7x,w6x,prefixlen,m) \ | |
217 | if (matches32(get_uint32(i6->s6_addr), \ | |
218 | ((uint32_t)0x##w7x << 16) | (uint32_t)0x##w6x, \ | |
219 | prefixlen)) \ | |
220 | DONT("IPv6 address is " m) | |
221 | DONTMASK( 100, 0, 8, "Discard-Only (RFC6666)"); | |
222 | DONTMASK(2001, 0, 23, "in IETF protocol block (RFC2928)"); | |
223 | #undef DONTMASK | |
224 | break; | |
225 | } | |
226 | case AF_INET: { | |
227 | const uint32_t i4=htonl(ia.sin.sin_addr.s_addr); | |
228 | if (i4==INADDR_ANY) DONT("IPv4 address is any/unspecified"); | |
229 | if (i4==INADDR_BROADCAST) DONT("IPv4 address is all hosts broadcast"); | |
230 | #define DONTMASK(b3,b2,b1,b0,prefixlen,m) do{ \ | |
231 | const uint8_t prefixbytes[4] = { (b3),(b2),(b1),(b0) }; \ | |
232 | if (matches32(i4,get_uint32(prefixbytes),prefixlen)) \ | |
233 | DONT("IPv4 address is " m); \ | |
234 | }while(0) | |
235 | DONTMASK(169,254,0,0, 16, "link local"); | |
236 | DONTMASK(224, 0,0,0, 4, "multicast"); | |
237 | DONTMASK(192, 0,0,0, 24, "in IETF protocol block (RFC6890)"); | |
238 | DONTMASK(240, 0,0,0, 4, "in reserved addressing block (RFC1112)"); | |
239 | if (!st->permit_loopback) | |
240 | DONTMASK(127, 0,0,0, 8, "loopback"); | |
241 | #undef DONTMASK | |
242 | break; | |
243 | } | |
244 | default: | |
245 | abort(); | |
246 | } | |
247 | ||
248 | /* OK, process it */ | |
249 | int n_ifs=0; | |
250 | LIST_FOREACH(interf,&st->interfs,entry) { | |
251 | if (!strcmp(interf->name,ifname)) | |
252 | goto found_interf; | |
253 | n_ifs++; | |
254 | } | |
255 | /* not found */ | |
256 | if (n_ifs==st->max_interfs) BAD("too many interfaces"); | |
257 | interf=malloc(sizeof(*interf)); | |
258 | if (!interf) BADE("malloc for new interface",errno); | |
259 | interf->name=0; | |
260 | interf->socks.n_socks=0; | |
261 | FILLZERO(interf->experienced_xmit_noaf); | |
262 | LIST_INSERT_HEAD(&st->interfs,interf,entry); | |
263 | udp_socks_register(&st->uc,&interf->socks); | |
264 | interf->name=strdup(ifname); | |
265 | if (!interf->name) BADE("strdup interface name",errno); | |
266 | found_interf: | |
267 | ||
268 | if (add) { | |
269 | if (interf->socks.n_socks == UDP_MAX_SOCKETS) | |
270 | BAD("too many addresses on this interface"); | |
271 | struct udpsock *us=&interf->socks.socks[interf->socks.n_socks]; | |
272 | us->fd=-1; | |
273 | COPY_OBJ(us->addr,ia); | |
274 | bool_t ok=udp_make_socket(&st->uc,us,M_WARNING); | |
275 | if (!ok) BAD("unable to set up socket"); | |
276 | r=setsockopt(us->fd,SOL_SOCKET,SO_BINDTODEVICE, | |
277 | ifname,strlen(ifname)+1); | |
278 | if (r) BADE("setsockopt(,,SO_BINDTODEVICE,)",errno); | |
279 | interf->socks.n_socks++; | |
280 | us=0; /* do not destroy this socket during `out' */ | |
281 | lg_perror(LG,M_INFO,0,"using %s %s",ifname,ifaddr); | |
282 | } else { | |
283 | int i; | |
284 | for (i=0; i<interf->socks.n_socks; i++) | |
285 | if (!memcmp(&interf->socks.socks[i].addr,&ia,sizeof(ia))) | |
286 | goto address_remove_found; | |
287 | BAD("address to remove not found"); | |
288 | address_remove_found: | |
289 | lg_perror(LG,M_INFO,0,"removed %s %s",ifname,ifaddr); | |
290 | udp_destroy_socket(&st->uc,&interf->socks.socks[i]); | |
291 | interf->socks.socks[i]= | |
292 | interf->socks.socks[--interf->socks.n_socks]; | |
293 | } | |
294 | ||
295 | out: | |
296 | if (us) | |
297 | udp_destroy_socket(uc,us); | |
298 | if (interf && !interf->socks.n_socks) { | |
299 | udp_socks_deregister(&st->uc,&interf->socks); | |
300 | LIST_REMOVE(interf,entry); | |
301 | free(interf->name); | |
302 | free(interf); | |
303 | } | |
304 | ||
305 | dump_ppml(st,0); | |
306 | ||
307 | #undef BAD | |
308 | #undef BADE | |
309 | #undef DONT | |
310 | } | |
311 | ||
312 | static void polypath_afterpoll(void *state, struct pollfd *fds, int nfds) | |
313 | { | |
314 | struct polypath *st=state; | |
315 | enum async_linebuf_result alr; | |
316 | const char *emsg; | |
317 | int status; | |
318 | ||
319 | if (nfds<1) return; | |
320 | ||
321 | while ((alr=async_linebuf_read(fds,&st->lbuf,&emsg)) == async_linebuf_ok) | |
322 | polypath_process_monitor_line(st,st->lbuf.base); | |
323 | ||
324 | if (alr==async_linebuf_nothing) | |
325 | return; | |
326 | ||
327 | assert(st->monitor_pid); | |
328 | ||
329 | pid_t gotpid=waitpid(st->monitor_pid,&status,WNOHANG); | |
330 | if (gotpid==st->monitor_pid) { | |
331 | st->monitor_pid=0; | |
332 | lg_exitstatus(LG,M_FATAL,status,"interface monitor"); | |
333 | } else if (gotpid<0) | |
334 | lg_perror(LG,M_ERR,errno,"unable to reap interface monitor"); | |
335 | else | |
336 | assert(gotpid==0); | |
337 | ||
338 | if (alr==async_linebuf_eof) | |
339 | lg_perror(LG,M_FATAL,0,"unexpected EOF from interface monitor"); | |
340 | else | |
341 | lg_perror(LG,M_FATAL,0,"bad output from interface monitor: %s",emsg); | |
342 | ||
343 | assert(!"not reached"); | |
344 | } | |
345 | ||
346 | /* Actual udp packet sending work */ | |
347 | static bool_t polypath_sendmsg(void *commst, struct buffer_if *buf, | |
348 | const struct comm_addr *dest) | |
349 | { | |
350 | struct polypath *st=commst; | |
351 | struct interf *interf; | |
352 | bool_t allreasonable=True; | |
353 | int af=dest->ia.sa.sa_family; | |
354 | ||
355 | LIST_FOREACH(interf,&st->interfs,entry) { | |
356 | int i; | |
357 | bool_t attempted=False, reasonable=False; | |
358 | for (i=0; i<interf->socks.n_socks; i++) { | |
359 | struct udpsock *us=&interf->socks.socks[i]; | |
360 | if (af != us->addr.sa.sa_family) | |
361 | continue; | |
362 | attempted=True; | |
363 | int r=sendto(us->fd,buf->start,buf->size, | |
364 | 0,&dest->ia.sa,iaddr_socklen(&dest->ia)); | |
365 | udp_sock_experienced(0,&st->uc, interf->name,us, | |
366 | 1,af, r,errno); | |
367 | if (r>=0) { | |
368 | reasonable=True; | |
369 | break; | |
370 | } | |
371 | if (!(errno==EAFNOSUPPORT || errno==ENETUNREACH)) | |
372 | reasonable=True; | |
373 | lg_perror(LG,M_DEBUG,errno,"%s [%s] xmit %"PRIu32" bytes to %s", | |
374 | interf->name,iaddr_to_string(&us->addr), | |
375 | buf->size,iaddr_to_string(&dest->ia)); | |
376 | } | |
377 | if (!attempted) | |
378 | if (!interf->experienced_xmit_noaf[af]++) | |
379 | lg_perror(LG,M_WARNING,0, | |
380 | "%s has no suitable address to transmit %s", | |
381 | interf->name, af_name(af)); | |
382 | allreasonable *= reasonable; | |
383 | } | |
384 | return allreasonable; | |
385 | } | |
386 | ||
387 | static void polypath_phase_startmonitor(void *sst, uint32_t newphase) | |
388 | { | |
389 | struct polypath *st=sst; | |
390 | int pfds[2]; | |
391 | ||
392 | assert(!st->monitor_pid); | |
393 | assert(st->monitor_fd<0); | |
394 | ||
395 | pipe_cloexec(pfds); | |
396 | ||
397 | pid_t pid=fork(); | |
398 | if (!pid) { | |
399 | afterfork(); | |
400 | dup2(pfds[1],1); | |
401 | execvp(st->monitor_command[0],(char**)st->monitor_command); | |
402 | fprintf(stderr,"secnet: cannot execute %s: %s\n", | |
403 | st->monitor_command[0], strerror(errno)); | |
404 | exit(-1); | |
405 | } | |
406 | if (pid<0) | |
407 | fatal_perror("%s: failed to fork for interface monitor", | |
408 | st->uc.cc.cl.description); | |
409 | ||
410 | close(pfds[1]); | |
411 | st->monitor_pid=pid; | |
412 | st->monitor_fd=pfds[0]; | |
413 | setnonblock(st->monitor_fd); | |
414 | ||
415 | register_for_poll(st,polypath_beforepoll,polypath_afterpoll,"polypath"); | |
416 | } | |
417 | ||
418 | static void polypath_phase_shutdown(void *sst, uint32_t newphase) | |
419 | { | |
420 | struct polypath *st=sst; | |
421 | if (st->monitor_pid) { | |
422 | assert(st->monitor_pid>0); | |
423 | kill(st->monitor_pid,SIGTERM); | |
424 | } | |
425 | } | |
426 | ||
427 | static list_t *polypath_apply(closure_t *self, struct cloc loc, | |
428 | dict_t *context, list_t *args) | |
429 | { | |
430 | struct polypath *st; | |
431 | ||
432 | COMM_APPLY(st,&st->uc.cc,polypath_,"polypath",loc); | |
433 | COMM_APPLY_STANDARD(st,&st->uc.cc,"polypath",args); | |
434 | UDP_APPLY_STANDARD(st,&st->uc,"polypath"); | |
435 | ||
436 | struct udpcommon *uc=&st->uc; | |
437 | struct commcommon *cc=&uc->cc; | |
438 | ||
439 | st->max_interfs=dict_read_number(d,"max-interfaces",False,"polypath",loc,3); | |
440 | ||
441 | st->ifname_pats=dict_read_string_array(d,"interfaces",False,"polypath", | |
442 | cc->loc,0); | |
443 | st->permit_loopback=0; /* ifname_wanted reads this */ | |
444 | ifname_wanted(st,st->uc.cc.loc," "); /* try to check each pattern */ | |
445 | ||
446 | st->monitor_command=dict_read_string_array(d,"monitor-command",False, | |
447 | "polypath",cc->loc, default_monitor_command); | |
448 | if (!st->monitor_command[0]) | |
449 | cfgfatal(loc,"polypath","no polypath interface monitor-command" | |
450 | " (polypath unsupported on this platform?)\n"); | |
451 | ||
452 | st->permit_loopback=dict_read_bool(d,"permit-loopback",False, | |
453 | "polypath",cc->loc,False); | |
454 | ||
455 | LIST_INIT(&st->interfs); | |
456 | buffer_new(&st->lbuf,ADNS_ADDR2TEXT_BUFLEN+100); | |
457 | BUF_ALLOC(&st->lbuf,"polypath lbuf"); | |
458 | ||
459 | st->monitor_fd=-1; | |
460 | st->monitor_pid=0; | |
461 | ||
462 | add_hook(PHASE_RUN, polypath_phase_startmonitor,st); | |
463 | add_hook(PHASE_SHUTDOWN, polypath_phase_shutdown, st); | |
464 | ||
465 | return new_closure(&cc->cl); | |
466 | } | |
467 | ||
468 | #endif /* CONFIG_IPV6 */ | |
469 | ||
470 | void polypath_module(dict_t *dict) | |
471 | { | |
472 | #ifdef CONFIG_IPV6 | |
473 | add_closure(dict,"polypath",polypath_apply); | |
474 | #endif /* CONFIG_IPV6 */ | |
475 | } |