Commit | Line | Data |
---|---|---|
ce5c098f IJ |
1 | /* polypath |
2 | * send/receive module for secnet | |
3 | * for multi-route setups */ | |
c215a4bc IJ |
4 | /* |
5 | * This file is part of secnet. | |
6 | * See README for full list of copyright holders. | |
7 | * | |
8 | * secnet is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version d of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * secnet is distributed in the hope that it will be useful, but | |
14 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * version 3 along with secnet; if not, see | |
20 | * https://www.gnu.org/licenses/gpl.html. | |
21 | */ | |
ce5c098f IJ |
22 | |
23 | #include "secnet.h" | |
24 | #include "util.h" | |
25 | #include "unaligned.h" | |
26 | #include "comm-common.h" | |
27 | ||
28 | #include <adns.h> | |
29 | #include <ctype.h> | |
30 | ||
31 | #ifdef CONFIG_IPV6 | |
32 | ||
33 | static comm_sendmsg_fn polypath_sendmsg; | |
34 | ||
35 | struct interf { | |
36 | char *name; /* from malloc */ | |
37 | struct udpsocks socks; | |
38 | bool_t experienced_xmit_noaf[MAX_AF+1]; | |
39 | LIST_ENTRY(interf) entry; | |
40 | }; | |
41 | ||
42 | struct polypath { | |
43 | struct udpcommon uc; | |
44 | int max_interfs; | |
45 | const char *const *ifname_pats; | |
46 | const char *const *monitor_command; | |
47 | bool_t permit_loopback; | |
03cbfbd2 IJ |
48 | LIST_HEAD(interf_list, interf) interfs_general; |
49 | struct interf_list interfs_dedicated; | |
ce5c098f IJ |
50 | struct buffer_if lbuf; |
51 | int monitor_fd; | |
52 | pid_t monitor_pid; | |
93cdea57 IJ |
53 | int privsep_incoming_fd; |
54 | int privsep_ipcsock_fd; | |
ce5c098f IJ |
55 | }; |
56 | ||
03cbfbd2 IJ |
57 | struct comm_clientinfo { |
58 | union iaddr dedicated; /* might be AF_UNSPEC */ | |
59 | }; | |
60 | ||
93cdea57 IJ |
61 | static void polypath_phase_shutdown(void *sst, uint32_t newphase); |
62 | ||
ce5c098f IJ |
63 | #define LG 0, st->uc.cc.cl.description, &st->uc.cc.loc |
64 | ||
65 | static const char *const default_loopback_ifname_pats[] = { | |
66 | "!lo", 0 | |
67 | }; | |
68 | static const char *const default_ifname_pats[] = { | |
03cbfbd2 | 69 | "!tun*","!tap*","!sl*","!userv*", "@hippo*", "*", 0 |
ce5c098f IJ |
70 | }; |
71 | ||
72 | static const char *const default_monitor_command[] = { | |
e61a41a4 IJ |
73 | #if __linux__ |
74 | DATAROOTDIR "/secnet/" "polypath-interface-monitor-linux", 0 | |
75 | #else | |
ce5c098f | 76 | 0 |
e61a41a4 | 77 | #endif |
ce5c098f IJ |
78 | }; |
79 | ||
80 | static const char *polypath_addr_to_string(void *commst, | |
81 | const struct comm_addr *ca) | |
82 | { | |
83 | static char sbuf[100]; | |
84 | ||
85 | snprintf(sbuf, sizeof(sbuf), "polypath:%s", | |
86 | iaddr_to_string(&ca->ia)); | |
87 | return sbuf; | |
88 | } | |
89 | ||
90 | static bool_t ifname_search_pats(struct polypath *st, struct cloc loc, | |
7b713549 | 91 | const char *ifname, char *want_io, |
ce5c098f IJ |
92 | const char *const *pats) { |
93 | /* Returns True iff we found a list entry, in which case *want_io | |
94 | * is set to the sense of that entry. Otherwise *want_io is set | |
95 | * to the sense of the last entry, or unchanged if there were no pats. */ | |
96 | if (!pats) | |
97 | return False; | |
98 | const char *const *pati; | |
99 | for (pati=pats; *pati; pati++) { | |
100 | const char *pat=*pati; | |
d8a024fe | 101 | if (*pat=='!' || *pat=='+' || *pat=='@') { *want_io=*pat; pat++; } |
7b713549 | 102 | else if (*pat=='*' || isalnum((unsigned char)*pat)) { *want_io='+'; } |
ce5c098f IJ |
103 | else cfgfatal(loc,"polypath","invalid interface name pattern `%s'",pat); |
104 | int match=fnmatch(pat,ifname,0); | |
105 | if (match==0) return True; | |
106 | if (match!=FNM_NOMATCH) | |
107 | cfgfatal(loc,"polypath","fnmatch failed! (pattern `%s')",pat); | |
108 | } | |
109 | return False; | |
110 | } | |
111 | ||
7b713549 IJ |
112 | static char ifname_wanted(struct polypath *st, struct cloc loc, |
113 | const char *ifname) { | |
114 | char want='!'; /* pretend an empty cfg ends with !<doesn'tmatch> */ | |
ce5c098f IJ |
115 | if (ifname_search_pats(st,loc,ifname,&want, st->ifname_pats)) |
116 | return want; | |
7b713549 IJ |
117 | if (want!='!') /* last pattern was positive, do not search default */ |
118 | return '!'; | |
ce5c098f IJ |
119 | if (!st->permit_loopback && |
120 | ifname_search_pats(st,loc,ifname,&want, default_loopback_ifname_pats)) | |
121 | return want; | |
122 | if (ifname_search_pats(st,loc,ifname,&want, default_ifname_pats)) | |
123 | return want; | |
124 | abort(); | |
125 | } | |
126 | ||
03cbfbd2 IJ |
127 | static struct comm_clientinfo *polypath_clientinfo(void *state, |
128 | dict_t *dict, struct cloc cloc) { | |
129 | struct comm_clientinfo *clientinfo; | |
130 | ||
131 | NEW(clientinfo); | |
132 | FILLZERO(*clientinfo); | |
133 | clientinfo->dedicated.sa.sa_family=AF_UNSPEC; | |
134 | ||
135 | item_t *item = dict_find_item(dict,"dedicated-interface-addr", | |
136 | False,"polypath",cloc); | |
137 | if (item) string_item_to_iaddr(item,0,&clientinfo->dedicated, | |
138 | "polypath"); | |
139 | return clientinfo; | |
140 | } | |
141 | ||
ce5c098f IJ |
142 | static int polypath_beforepoll(void *state, struct pollfd *fds, int *nfds_io, |
143 | int *timeout_io) | |
144 | { | |
145 | struct polypath *st=state; | |
146 | BEFOREPOLL_WANT_FDS(1); | |
147 | fds[0].fd=st->monitor_fd; | |
148 | fds[0].events=POLLIN; | |
149 | return 0; | |
150 | } | |
151 | ||
ce5c098f IJ |
152 | static inline bool_t matches32(uint32_t word, uint32_t prefix, int prefixlen) |
153 | { | |
154 | assert(prefixlen>0); | |
155 | assert(prefixlen<=32); | |
156 | uint32_t mask = ~(((uint32_t)1 << (32-prefixlen)) - 1); | |
157 | assert(!(prefix & ~mask)); | |
158 | return (word & mask) == prefix; | |
159 | } | |
160 | ||
70ad8e2c IJ |
161 | /* These macros expect |
162 | * bad_fn_type *const bad; | |
163 | * void *badctx; | |
164 | * and | |
165 | * out: | |
166 | */ | |
84dcd42d IJ |
167 | #define BAD(m) do{ bad(st,badctx,M_WARNING,m,0); goto out; }while(0) |
168 | #define BADE(m,ev) do{ bad(st,badctx,M_WARNING,m,ev); goto out; }while(0) | |
70ad8e2c | 169 | typedef void bad_fn_type(struct polypath *st, void *badctx, |
84dcd42d | 170 | int mclass, const char* m, int ev); |
70ad8e2c IJ |
171 | |
172 | typedef void polypath_ppml_callback_type(struct polypath *st, | |
173 | bad_fn_type *bad, void *badctx, | |
65d6d32e IJ |
174 | bool_t add, char want, |
175 | const char *ifname, const char *ifaddr, | |
70ad8e2c IJ |
176 | const union iaddr *ia, int fd /* -1 if none yet */); |
177 | ||
178 | struct ppml_bad_ctx { | |
179 | const char *orgl; | |
180 | char *undospace; | |
181 | }; | |
182 | ||
84dcd42d IJ |
183 | static void ppml_bad(struct polypath *st, void *badctx, |
184 | int mclass, const char *m, int ev) | |
70ad8e2c IJ |
185 | { |
186 | struct ppml_bad_ctx *bc=badctx; | |
187 | if (bc->undospace) | |
188 | *(bc->undospace)=' '; | |
84dcd42d | 189 | lg_perror(LG,mclass,ev, |
70ad8e2c IJ |
190 | "error processing polypath state change: %s" |
191 | " (while processing `%s')", | |
192 | m,bc->orgl); | |
193 | } | |
194 | ||
195 | static void polypath_process_monitor_line(struct polypath *st, char *orgl, | |
196 | polypath_ppml_callback_type *callback) | |
197 | /* always calls callback with fd==-1 */ | |
ce5c098f | 198 | { |
ce5c098f | 199 | struct udpcommon *uc=&st->uc; |
ce5c098f | 200 | char *l=orgl; |
70ad8e2c IJ |
201 | bad_fn_type (*const bad)=ppml_bad; |
202 | struct ppml_bad_ctx badctx[1]={{ | |
203 | .orgl=orgl, | |
204 | .undospace=0 | |
205 | }}; | |
ce5c098f IJ |
206 | |
207 | bool_t add; | |
208 | int c=*l++; | |
209 | if (c=='+') add=True; | |
210 | else if (c=='-') add=False; | |
211 | else BAD("bad +/-"); | |
212 | ||
213 | int proto; | |
214 | c=*l++; | |
215 | if (c=='4') proto=AF_INET; | |
216 | else if (c=='6') proto=AF_INET6; | |
217 | else BAD("bad proto"); | |
218 | ||
219 | char *space=strchr(l,' '); | |
220 | if (!space) BAD("no first space"); | |
221 | const char *ifname=space+1; | |
222 | ||
223 | space=strchr(ifname,' '); | |
224 | if (!space) BAD("no second space"); | |
225 | const char *ifaddr=space+1; | |
226 | *space=0; | |
70ad8e2c | 227 | badctx->undospace=space; |
ce5c098f IJ |
228 | |
229 | union iaddr ia; | |
230 | FILLZERO(ia); | |
231 | socklen_t salen=sizeof(ia); | |
232 | int r=adns_text2addr(ifaddr,uc->port, adns_qf_addrlit_ipv4_quadonly, | |
233 | &ia.sa, &salen); | |
234 | assert(r!=ENOSPC); | |
235 | if (r) BADE("adns_text2addr",r); | |
236 | if (ia.sa.sa_family!=proto) BAD("address family mismatch"); | |
237 | ||
238 | #define DONT(m) do{ \ | |
239 | if (add) \ | |
240 | lg_perror(LG,M_INFO,0,"ignoring %s [%s]: %s",ifname,ifaddr,m); \ | |
241 | goto out; \ | |
242 | }while(0) | |
243 | ||
7b713549 IJ |
244 | char want=ifname_wanted(st,st->uc.cc.loc,ifname); |
245 | if (want=='!') DONT("unwanted interface name"); | |
ce5c098f IJ |
246 | |
247 | switch (ia.sa.sa_family) { | |
248 | case AF_INET6: { | |
249 | const struct in6_addr *i6=&ia.sin6.sin6_addr; | |
250 | #define DONTKIND(X,m) \ | |
251 | if (IN6_IS_ADDR_##X(i6)) DONT("IPv6 address is " m) | |
252 | DONTKIND(UNSPECIFIED, "unspecified"); | |
253 | DONTKIND(MULTICAST , "multicast" ); | |
254 | DONTKIND(LINKLOCAL , "link local" ); | |
255 | DONTKIND(SITELOCAL , "site local" ); | |
256 | DONTKIND(V4MAPPED , "v4-mapped" ); | |
257 | if (!st->permit_loopback) | |
258 | DONTKIND(LOOPBACK , "loopback" ); | |
259 | #undef DONTKIND | |
260 | #define DONTMASK(w7x,w6x,prefixlen,m) \ | |
261 | if (matches32(get_uint32(i6->s6_addr), \ | |
262 | ((uint32_t)0x##w7x << 16) | (uint32_t)0x##w6x, \ | |
263 | prefixlen)) \ | |
264 | DONT("IPv6 address is " m) | |
265 | DONTMASK( 100, 0, 8, "Discard-Only (RFC6666)"); | |
266 | DONTMASK(2001, 0, 23, "in IETF protocol block (RFC2928)"); | |
b073e347 | 267 | DONTMASK(fc00, 0, 7, "Uniqe Local unicast (RFC4193)"); |
ce5c098f IJ |
268 | #undef DONTMASK |
269 | break; | |
270 | } | |
271 | case AF_INET: { | |
272 | const uint32_t i4=htonl(ia.sin.sin_addr.s_addr); | |
273 | if (i4==INADDR_ANY) DONT("IPv4 address is any/unspecified"); | |
274 | if (i4==INADDR_BROADCAST) DONT("IPv4 address is all hosts broadcast"); | |
275 | #define DONTMASK(b3,b2,b1,b0,prefixlen,m) do{ \ | |
276 | const uint8_t prefixbytes[4] = { (b3),(b2),(b1),(b0) }; \ | |
277 | if (matches32(i4,get_uint32(prefixbytes),prefixlen)) \ | |
278 | DONT("IPv4 address is " m); \ | |
279 | }while(0) | |
280 | DONTMASK(169,254,0,0, 16, "link local"); | |
281 | DONTMASK(224, 0,0,0, 4, "multicast"); | |
282 | DONTMASK(192, 0,0,0, 24, "in IETF protocol block (RFC6890)"); | |
283 | DONTMASK(240, 0,0,0, 4, "in reserved addressing block (RFC1112)"); | |
284 | if (!st->permit_loopback) | |
285 | DONTMASK(127, 0,0,0, 8, "loopback"); | |
286 | #undef DONTMASK | |
287 | break; | |
288 | } | |
289 | default: | |
290 | abort(); | |
291 | } | |
292 | ||
70ad8e2c IJ |
293 | #undef DONT |
294 | ||
ce5c098f | 295 | /* OK, process it */ |
65d6d32e | 296 | callback(st, bad,badctx, add,want, ifname,ifaddr,&ia,-1); |
70ad8e2c IJ |
297 | |
298 | out:; | |
299 | } | |
300 | ||
65d6d32e IJ |
301 | static void dump_pria(struct polypath *st, struct interf_list *interfs, |
302 | const char *ifname, char want) | |
70ad8e2c IJ |
303 | { |
304 | #ifdef POLYPATH_DEBUG | |
305 | struct interf *interf; | |
306 | if (ifname) | |
65d6d32e IJ |
307 | lg_perror(LG,M_DEBUG,0, "polypath record ifaddr `%s' (%c)", |
308 | ifname, want); | |
309 | LIST_FOREACH(interf, interfs, entry) { | |
70ad8e2c IJ |
310 | lg_perror(LG,M_DEBUG,0, " polypath interface `%s', nsocks=%d", |
311 | interf->name, interf->socks.n_socks); | |
312 | int i; | |
313 | for (i=0; i<interf->socks.n_socks; i++) { | |
314 | struct udpsock *us=&interf->socks.socks[i]; | |
315 | lg_perror(LG,M_DEBUG,0, " polypath sock fd=%d addr=%s", | |
316 | us->fd, iaddr_to_string(&us->addr)); | |
317 | } | |
318 | } | |
319 | #endif | |
320 | } | |
321 | ||
322 | static bool_t polypath_make_socket(struct polypath *st, | |
323 | bad_fn_type *bad, void *badctx, | |
324 | struct udpsock *us, const char *ifname) | |
325 | /* on error exit has called bad; might leave us->fd as -1 */ | |
326 | { | |
327 | assert(us->fd==-1); | |
328 | ||
329 | bool_t ok=udp_make_socket(&st->uc,us,M_WARNING); | |
330 | if (!ok) BAD("unable to set up socket"); | |
331 | int r=setsockopt(us->fd,SOL_SOCKET,SO_BINDTODEVICE, | |
332 | ifname,strlen(ifname)+1); | |
333 | if (r) BADE("setsockopt(,,SO_BINDTODEVICE,)",errno); | |
334 | return True; | |
335 | ||
336 | out: | |
337 | return False; | |
338 | } | |
339 | ||
340 | static void polypath_record_ifaddr(struct polypath *st, | |
341 | bad_fn_type *bad, void *badctx, | |
65d6d32e IJ |
342 | bool_t add, char want, |
343 | const char *ifname, | |
70ad8e2c IJ |
344 | const char *ifaddr, |
345 | const union iaddr *ia, int fd) | |
346 | { | |
347 | struct udpcommon *uc=&st->uc; | |
348 | struct interf *interf=0; | |
65d6d32e | 349 | int max_interfs; |
70ad8e2c IJ |
350 | struct udpsock *us=0; |
351 | ||
65d6d32e IJ |
352 | struct interf_list *interfs; |
353 | switch (want) { | |
ce53e0ea | 354 | case '+': interfs=&st->interfs_general; max_interfs=st->max_interfs; break; |
98208aeb | 355 | case '@': interfs=&st->interfs_dedicated; max_interfs=INT_MAX; break; |
65d6d32e IJ |
356 | default: fatal("polypath: got bad want (%#x, %s)", want, ifname); |
357 | } | |
358 | ||
359 | dump_pria(st,interfs,ifname,want); | |
70ad8e2c | 360 | |
ce5c098f | 361 | int n_ifs=0; |
65d6d32e | 362 | LIST_FOREACH(interf,interfs,entry) { |
ce5c098f IJ |
363 | if (!strcmp(interf->name,ifname)) |
364 | goto found_interf; | |
365 | n_ifs++; | |
366 | } | |
367 | /* not found */ | |
65d6d32e | 368 | if (n_ifs==max_interfs) BAD("too many interfaces"); |
ce5c098f IJ |
369 | interf=malloc(sizeof(*interf)); |
370 | if (!interf) BADE("malloc for new interface",errno); | |
371 | interf->name=0; | |
372 | interf->socks.n_socks=0; | |
373 | FILLZERO(interf->experienced_xmit_noaf); | |
65d6d32e | 374 | LIST_INSERT_HEAD(interfs,interf,entry); |
ce5c098f | 375 | interf->name=strdup(ifname); |
c72d679d | 376 | udp_socks_register(&st->uc,&interf->socks,interf->name); |
ce5c098f IJ |
377 | if (!interf->name) BADE("strdup interface name",errno); |
378 | found_interf: | |
379 | ||
380 | if (add) { | |
381 | if (interf->socks.n_socks == UDP_MAX_SOCKETS) | |
382 | BAD("too many addresses on this interface"); | |
383 | struct udpsock *us=&interf->socks.socks[interf->socks.n_socks]; | |
384 | us->fd=-1; | |
70ad8e2c IJ |
385 | COPY_OBJ(us->addr,*ia); |
386 | if (fd<0) { | |
387 | bool_t ok=polypath_make_socket(st,bad,badctx, us,ifname); | |
388 | if (!ok) goto out; | |
389 | } else { | |
9c44ef13 IJ |
390 | bool_t ok=udp_import_socket(uc,us,M_WARNING,fd); |
391 | if (!ok) goto out; | |
70ad8e2c IJ |
392 | fd=-1; |
393 | } | |
ce5c098f | 394 | interf->socks.n_socks++; |
9c44ef13 IJ |
395 | lg_perror(LG,M_INFO,0,"using %s %s",ifname, |
396 | iaddr_to_string(&us->addr)); | |
ce5c098f | 397 | us=0; /* do not destroy this socket during `out' */ |
ce5c098f IJ |
398 | } else { |
399 | int i; | |
400 | for (i=0; i<interf->socks.n_socks; i++) | |
9c44ef13 | 401 | if (iaddr_equal(&interf->socks.socks[i].addr,ia,True)) |
ce5c098f | 402 | goto address_remove_found; |
c69b984e IJ |
403 | bad(st,badctx,M_DEBUG,"address to remove not found",0); |
404 | goto out; | |
ce5c098f | 405 | address_remove_found: |
9c44ef13 IJ |
406 | lg_perror(LG,M_INFO,0,"removed %s %s",ifname, |
407 | iaddr_to_string(&interf->socks.socks[i].addr)); | |
ce5c098f IJ |
408 | udp_destroy_socket(&st->uc,&interf->socks.socks[i]); |
409 | interf->socks.socks[i]= | |
410 | interf->socks.socks[--interf->socks.n_socks]; | |
411 | } | |
412 | ||
413 | out: | |
414 | if (us) | |
415 | udp_destroy_socket(uc,us); | |
70ad8e2c IJ |
416 | if (fd>=0) |
417 | close(fd); | |
ce5c098f IJ |
418 | if (interf && !interf->socks.n_socks) { |
419 | udp_socks_deregister(&st->uc,&interf->socks); | |
420 | LIST_REMOVE(interf,entry); | |
421 | free(interf->name); | |
422 | free(interf); | |
423 | } | |
424 | ||
65d6d32e | 425 | dump_pria(st,interfs,0,0); |
ce5c098f IJ |
426 | } |
427 | ||
23ca1537 IJ |
428 | static void subproc_problem(struct polypath *st, |
429 | enum async_linebuf_result alr, const char *emsg) | |
ce5c098f | 430 | { |
ce5c098f | 431 | int status; |
ce5c098f IJ |
432 | assert(st->monitor_pid); |
433 | ||
434 | pid_t gotpid=waitpid(st->monitor_pid,&status,WNOHANG); | |
435 | if (gotpid==st->monitor_pid) { | |
436 | st->monitor_pid=0; | |
437 | lg_exitstatus(LG,M_FATAL,status,"interface monitor"); | |
438 | } else if (gotpid<0) | |
439 | lg_perror(LG,M_ERR,errno,"unable to reap interface monitor"); | |
440 | else | |
441 | assert(gotpid==0); | |
442 | ||
443 | if (alr==async_linebuf_eof) | |
444 | lg_perror(LG,M_FATAL,0,"unexpected EOF from interface monitor"); | |
445 | else | |
446 | lg_perror(LG,M_FATAL,0,"bad output from interface monitor: %s",emsg); | |
ce5c098f IJ |
447 | assert(!"not reached"); |
448 | } | |
449 | ||
93cdea57 | 450 | /* Used in non-privsep case, and in privsep child */ |
23ca1537 IJ |
451 | static void afterpoll_monitor(struct polypath *st, struct pollfd *fd, |
452 | polypath_ppml_callback_type *callback) | |
453 | { | |
454 | enum async_linebuf_result alr; | |
455 | const char *emsg; | |
456 | ||
457 | while ((alr=async_linebuf_read(fd,&st->lbuf,&emsg)) == async_linebuf_ok) | |
458 | polypath_process_monitor_line(st,st->lbuf.base,callback); | |
459 | ||
460 | if (alr==async_linebuf_nothing) | |
461 | return; | |
462 | ||
463 | subproc_problem(st,alr,emsg); | |
464 | } | |
465 | ||
93cdea57 | 466 | /* Used in non-privsep case only - glue for secnet main loop */ |
23ca1537 IJ |
467 | static void polypath_afterpoll_monitor(void *state, struct pollfd *fds, |
468 | int nfds) | |
469 | { | |
470 | struct polypath *st=state; | |
471 | if (nfds<1) return; | |
472 | afterpoll_monitor(st,fds,polypath_record_ifaddr); | |
473 | } | |
474 | ||
ce5c098f | 475 | /* Actual udp packet sending work */ |
bfd718e6 IJ |
476 | |
477 | static void polypath_sendmsg_interf(struct polypath *st, | |
478 | struct interf *interf, | |
479 | struct buffer_if *buf, | |
480 | const struct comm_addr *dest, | |
03cbfbd2 | 481 | const union iaddr *dedicated, |
bfd718e6 IJ |
482 | bool_t *allreasonable) |
483 | { | |
484 | int i; | |
485 | int af=dest->ia.sa.sa_family; | |
03cbfbd2 | 486 | bool_t wanted=False, attempted=False, reasonable=False; |
bfd718e6 IJ |
487 | |
488 | for (i=0; i<interf->socks.n_socks; i++) { | |
489 | struct udpsock *us=&interf->socks.socks[i]; | |
03cbfbd2 IJ |
490 | if (dedicated && !iaddr_equal(dedicated, &us->addr, True)) |
491 | continue; | |
492 | wanted=True; | |
bfd718e6 IJ |
493 | if (af != us->addr.sa.sa_family) |
494 | continue; | |
495 | attempted=True; | |
496 | int r=sendto(us->fd,buf->start,buf->size, | |
497 | 0,&dest->ia.sa,iaddr_socklen(&dest->ia)); | |
498 | udp_sock_experienced(0,&st->uc,&interf->socks,us, | |
499 | &dest->ia,af, r,errno); | |
500 | if (r>=0) { | |
501 | reasonable=True; | |
502 | break; | |
503 | } | |
504 | if (!(errno==EAFNOSUPPORT || errno==ENETUNREACH)) | |
505 | reasonable=True; | |
506 | lg_perror(LG,M_DEBUG,errno,"%s [%s] xmit %"PRIu32" bytes to %s", | |
507 | interf->name,iaddr_to_string(&us->addr), | |
508 | buf->size,iaddr_to_string(&dest->ia)); | |
509 | } | |
03cbfbd2 IJ |
510 | if (!wanted) |
511 | return; | |
512 | ||
bfd718e6 IJ |
513 | if (!attempted) |
514 | if (!interf->experienced_xmit_noaf[af]++) | |
515 | lg_perror(LG,M_WARNING,0, | |
516 | "%s has no suitable address to transmit %s", | |
517 | interf->name, af_name(af)); | |
518 | ||
519 | *allreasonable *= reasonable; | |
520 | } | |
521 | ||
ce5c098f | 522 | static bool_t polypath_sendmsg(void *commst, struct buffer_if *buf, |
2d80199d IJ |
523 | const struct comm_addr *dest, |
524 | struct comm_clientinfo *clientinfo) | |
ce5c098f IJ |
525 | { |
526 | struct polypath *st=commst; | |
527 | struct interf *interf; | |
528 | bool_t allreasonable=True; | |
ce5c098f | 529 | |
03cbfbd2 | 530 | LIST_FOREACH(interf,&st->interfs_general,entry) { |
bfd718e6 | 531 | polypath_sendmsg_interf(st,interf,buf,dest, |
03cbfbd2 IJ |
532 | 0, &allreasonable); |
533 | } | |
534 | if (clientinfo && clientinfo->dedicated.sa.sa_family != AF_UNSPEC) { | |
535 | LIST_FOREACH(interf,&st->interfs_dedicated,entry) { | |
536 | polypath_sendmsg_interf(st,interf,buf,dest, | |
537 | &clientinfo->dedicated, &allreasonable); | |
538 | } | |
ce5c098f IJ |
539 | } |
540 | return allreasonable; | |
541 | } | |
542 | ||
93cdea57 | 543 | /* Non-privsep: called in (sole) child. Privsep: in grandchild. */ |
23ca1537 IJ |
544 | static void child_monitor(struct polypath *st, int childfd) |
545 | { | |
546 | dup2(childfd,1); | |
547 | execvp(st->monitor_command[0],(char**)st->monitor_command); | |
548 | fprintf(stderr,"secnet: cannot execute %s: %s\n", | |
549 | st->monitor_command[0], strerror(errno)); | |
550 | exit(-1); | |
551 | } | |
552 | ||
93cdea57 | 553 | /* General utility function. */ |
23ca1537 | 554 | static void start_subproc(struct polypath *st, void (*make_fdpair)(int[2]), |
83e03cac IJ |
555 | void (*child)(struct polypath *st, int childfd), |
556 | const char *desc) | |
ce5c098f | 557 | { |
ce5c098f IJ |
558 | int pfds[2]; |
559 | ||
560 | assert(!st->monitor_pid); | |
561 | assert(st->monitor_fd<0); | |
562 | ||
23ca1537 | 563 | make_fdpair(pfds); |
ce5c098f IJ |
564 | |
565 | pid_t pid=fork(); | |
566 | if (!pid) { | |
567 | afterfork(); | |
94a1d5fc | 568 | close(pfds[0]); |
23ca1537 IJ |
569 | child(st,pfds[1]); |
570 | abort(); | |
ce5c098f IJ |
571 | } |
572 | if (pid<0) | |
23ca1537 | 573 | fatal_perror("%s: failed to fork for interface monitoring", |
ce5c098f IJ |
574 | st->uc.cc.cl.description); |
575 | ||
576 | close(pfds[1]); | |
577 | st->monitor_pid=pid; | |
578 | st->monitor_fd=pfds[0]; | |
579 | setnonblock(st->monitor_fd); | |
83e03cac IJ |
580 | |
581 | lg_perror(LG,M_NOTICE,0, "%s: spawning %s [pid %ld]", | |
582 | st->uc.cc.cl.description, desc, (long)st->monitor_pid); | |
23ca1537 | 583 | } |
ce5c098f | 584 | |
93cdea57 | 585 | /* Non-privsep only: glue for forking the monitor, from the main loop */ |
23ca1537 IJ |
586 | static void polypath_phase_startmonitor(void *sst, uint32_t newphase) |
587 | { | |
588 | struct polypath *st=sst; | |
93cdea57 IJ |
589 | start_subproc(st,pipe_cloexec,child_monitor, |
590 | "interface monitor (no privsep)"); | |
23ca1537 IJ |
591 | register_for_poll(st,polypath_beforepoll, |
592 | polypath_afterpoll_monitor,"polypath"); | |
ce5c098f IJ |
593 | } |
594 | ||
93cdea57 IJ |
595 | /*----- Privsep-only: -----*/ |
596 | ||
597 | /* | |
598 | * We use two subprocesses, a child and a grandchild. These are | |
599 | * forked before secnet drops privilege. | |
600 | * | |
601 | * The grandchild is the same interface monitor helper script as used | |
602 | * in the non-privsep case. But its lines are read by the child | |
603 | * instead of by the main secnet. The child is responsible for | |
604 | * creating the actual socket (binding it, etc.). Each socket is | |
605 | * passed to secnet proper via fd passing, along with a data message | |
606 | * describing the interface name and address. The child does not | |
607 | * retain a list of current interfaces and addresses - it trusts the | |
608 | * interface monitor to get that right. secnet proper still maintains | |
609 | * that data structure. | |
610 | * | |
611 | * The result is that much of the non-privsep code can be reused, but | |
612 | * just plumbed together differently. | |
613 | * | |
614 | * The child does not retain the socket after passing it on. | |
615 | * Interface removals are handled similarly but without any fd. | |
616 | * | |
617 | * The result is that the configuration's limits on which interfaces | |
618 | * and ports secnet may use are enforced by the privileged child. | |
619 | */ | |
620 | ||
621 | struct privsep_mdata { | |
622 | bool_t add; | |
623 | char ifname[100]; | |
624 | union iaddr ia; | |
03cbfbd2 | 625 | char want; /* `+' or `@' */ |
93cdea57 IJ |
626 | }; |
627 | ||
84dcd42d IJ |
628 | static void papp_bad(struct polypath *st, void *badctx, |
629 | int mclass, const char *m, int ev) | |
93cdea57 IJ |
630 | { |
631 | const struct privsep_mdata *mdata=(const void*)st->lbuf.start; | |
632 | const char *addr_str=badctx; | |
633 | ||
84dcd42d | 634 | lg_perror(LG,mclass,ev, |
93cdea57 IJ |
635 | "error processing polypath address change %s %s [%s]: %s", |
636 | mdata->add ? "+" : "-", | |
637 | mdata->ifname, addr_str, m); | |
638 | } | |
639 | ||
640 | static void polypath_afterpoll_privsep(void *state, struct pollfd *fds, | |
641 | int nfds) | |
642 | /* In secnet proper; receives messages from child. */ | |
643 | { | |
644 | struct polypath *st=state; | |
645 | ||
646 | if (nfds<1) return; | |
647 | ||
648 | int revents=fds[0].revents; | |
649 | ||
650 | const char *badbit=pollbadbit(revents); | |
651 | if (badbit) subproc_problem(st,async_linebuf_broken,badbit); | |
652 | ||
653 | if (!(revents & POLLIN)) return; | |
654 | ||
655 | for (;;) { | |
656 | if (st->lbuf.size==sizeof(struct privsep_mdata)) { | |
657 | const struct privsep_mdata *mdata=(const void*)st->lbuf.start; | |
658 | if (mdata->add && st->privsep_incoming_fd<0) | |
659 | fatal("polypath (privsep): got add message data but no fd"); | |
660 | if (!mdata->add && st->privsep_incoming_fd>=0) | |
661 | fatal("polypath (privsep): got remove message data with fd"); | |
662 | if (!memchr(mdata->ifname,0,sizeof(mdata->ifname))) | |
663 | fatal("polypath (privsep): got ifname with no terminating nul"); | |
664 | int af=mdata->ia.sa.sa_family; | |
665 | if (!(af==AF_INET6 || af==AF_INET)) | |
666 | fatal("polypath (privsep): got message data but bad AF %d",af); | |
667 | const char *addr_str=iaddr_to_string(&mdata->ia); | |
668 | polypath_record_ifaddr(st,papp_bad,(void*)addr_str, | |
65d6d32e IJ |
669 | mdata->add,mdata->want, |
670 | mdata->ifname,addr_str, | |
93cdea57 IJ |
671 | &mdata->ia, st->privsep_incoming_fd); |
672 | st->privsep_incoming_fd=-1; | |
673 | st->lbuf.size=0; | |
674 | } | |
675 | struct msghdr msg; | |
676 | int fd; | |
677 | size_t cmsgdatalen=sizeof(fd); | |
678 | char cmsg_control_buf[CMSG_SPACE(cmsgdatalen)]; | |
679 | struct iovec iov; | |
680 | ||
681 | FILLZERO(msg); | |
682 | msg.msg_iov=&iov; | |
683 | msg.msg_iovlen=1; | |
684 | ||
685 | iov.iov_base=st->lbuf.start+st->lbuf.size; | |
686 | iov.iov_len=sizeof(struct privsep_mdata)-st->lbuf.size; | |
687 | ||
688 | if (st->privsep_incoming_fd<0) { | |
689 | msg.msg_control=cmsg_control_buf; | |
690 | msg.msg_controllen=sizeof(cmsg_control_buf); | |
691 | } | |
692 | ||
693 | ssize_t got=recvmsg(st->monitor_fd,&msg,0); | |
694 | if (got<0) { | |
695 | if (errno==EINTR) continue; | |
696 | if (iswouldblock(errno)) break; | |
697 | fatal_perror("polypath (privsep): recvmsg failed"); | |
698 | } | |
699 | if (got==0) | |
700 | subproc_problem(st,async_linebuf_eof,0); | |
701 | ||
702 | st->lbuf.size+=got; | |
703 | ||
704 | if (msg.msg_controllen) { | |
705 | size_t cmsgdatalen=sizeof(st->privsep_incoming_fd); | |
706 | struct cmsghdr *h=CMSG_FIRSTHDR(&msg); | |
707 | if (!(st->privsep_incoming_fd==-1 && | |
708 | h && | |
709 | h->cmsg_level==SOL_SOCKET && | |
710 | h->cmsg_type==SCM_RIGHTS && | |
711 | h->cmsg_len==CMSG_LEN(cmsgdatalen) && | |
712 | !CMSG_NXTHDR(&msg,h))) | |
713 | subproc_problem(st,async_linebuf_broken,"bad cmsg"); | |
714 | memcpy(&st->privsep_incoming_fd,CMSG_DATA(h),cmsgdatalen); | |
715 | assert(st->privsep_incoming_fd>=0); | |
716 | } | |
717 | ||
718 | } | |
719 | } | |
720 | ||
721 | static void privsep_handle_ifaddr(struct polypath *st, | |
722 | bad_fn_type *bad, void *badctx, | |
65d6d32e IJ |
723 | bool_t add, char want, |
724 | const char *ifname, | |
93cdea57 IJ |
725 | const char *ifaddr, |
726 | const union iaddr *ia, int fd_dummy) | |
727 | /* In child: handles discovered wanted interfaces, making sockets | |
728 | and sending them to secnet proper. */ | |
729 | { | |
730 | struct msghdr msg; | |
731 | struct iovec iov; | |
732 | struct udpsock us={ .fd=-1 }; | |
733 | size_t cmsgdatalen=sizeof(us.fd); | |
734 | char cmsg_control_buf[CMSG_SPACE(cmsgdatalen)]; | |
735 | ||
736 | assert(fd_dummy==-1); | |
737 | ||
738 | struct privsep_mdata mdata; | |
739 | FILLZERO(mdata); | |
740 | mdata.add=add; | |
741 | ||
742 | size_t l=strlen(ifname); | |
743 | if (l>=sizeof(mdata.ifname)) BAD("interface name too long"); | |
744 | strcpy(mdata.ifname,ifname); | |
65d6d32e | 745 | mdata.want=want; |
93cdea57 IJ |
746 | |
747 | COPY_OBJ(mdata.ia,*ia); | |
748 | ||
749 | iov.iov_base=&mdata; | |
750 | iov.iov_len =sizeof(mdata); | |
751 | ||
752 | FILLZERO(msg); | |
753 | msg.msg_iov=&iov; | |
754 | msg.msg_iovlen=1; | |
755 | ||
756 | if (add) { | |
757 | COPY_OBJ(us.addr,*ia); | |
758 | bool_t ok=polypath_make_socket(st,bad,badctx,&us,ifname); | |
759 | if (!ok) goto out; | |
760 | ||
761 | msg.msg_control=cmsg_control_buf; | |
762 | msg.msg_controllen=sizeof(cmsg_control_buf); | |
763 | ||
764 | struct cmsghdr *h=CMSG_FIRSTHDR(&msg); | |
765 | h->cmsg_level=SOL_SOCKET; | |
766 | h->cmsg_type =SCM_RIGHTS; | |
767 | h->cmsg_len =CMSG_LEN(cmsgdatalen); | |
768 | memcpy(CMSG_DATA(h),&us.fd,cmsgdatalen); | |
769 | } | |
770 | ||
771 | while (iov.iov_len) { | |
772 | ssize_t got=sendmsg(st->privsep_ipcsock_fd,&msg,0); | |
773 | if (got<0) { | |
774 | if (errno!=EINTR) fatal_perror("polypath privsep sendmsg"); | |
775 | got=0; | |
776 | } else { | |
777 | assert(got>0); | |
778 | assert((size_t)got<=iov.iov_len); | |
779 | } | |
780 | iov.iov_base=(char*)iov.iov_base+got; | |
781 | iov.iov_len-=got; | |
782 | msg.msg_control=0; | |
783 | msg.msg_controllen=0; | |
784 | } | |
785 | ||
786 | out: | |
787 | if (us.fd>=0) close(us.fd); | |
788 | } | |
789 | ||
790 | static void child_privsep(struct polypath *st, int ipcsockfd) | |
791 | /* Privsep child main loop. */ | |
792 | { | |
793 | struct pollfd fds[2]; | |
794 | ||
795 | enter_phase(PHASE_CHILDPERSIST); | |
796 | ||
797 | st->privsep_ipcsock_fd=ipcsockfd; | |
798 | start_subproc(st,pipe_cloexec,child_monitor, | |
799 | "interface monitor (grandchild)"); | |
800 | for (;;) { | |
801 | int nfds=1; | |
802 | int r=polypath_beforepoll(st,fds,&nfds,0); | |
803 | assert(nfds==1); | |
804 | assert(!r); | |
805 | ||
806 | fds[1].fd=st->privsep_ipcsock_fd; | |
807 | fds[1].events=POLLIN; | |
808 | ||
809 | r=poll(fds,ARRAY_SIZE(fds),-1); | |
810 | ||
811 | if (r<0) { | |
812 | if (errno==EINTR) continue; | |
813 | fatal_perror("polypath privsep poll"); | |
814 | } | |
815 | if (fds[1].revents) { | |
816 | if (fds[1].revents & (POLLHUP|POLLIN)) { | |
817 | polypath_phase_shutdown(st,PHASE_SHUTDOWN); | |
818 | exit(0); | |
819 | } | |
820 | fatal("polypath privsep poll parent socket revents=%#x", | |
821 | fds[1].revents); | |
822 | } | |
823 | if (fds[0].revents & POLLNVAL) | |
824 | fatal("polypath privsep poll child socket POLLNVAL"); | |
825 | afterpoll_monitor(st,fds,privsep_handle_ifaddr); | |
826 | } | |
827 | } | |
828 | ||
829 | static void privsep_socketpair(int *fd) | |
830 | { | |
831 | int r=socketpair(AF_UNIX,SOCK_STREAM,0,fd); | |
832 | if (r) fatal_perror("socketpair(AF_UNIX,SOCK_STREAM,,)"); | |
833 | setcloexec(fd[0]); | |
834 | setcloexec(fd[1]); | |
835 | } | |
836 | ||
837 | static void polypath_phase_startprivsep(void *sst, uint32_t newphase) | |
838 | { | |
839 | struct polypath *st=sst; | |
840 | ||
841 | if (!will_droppriv()) { | |
842 | add_hook(PHASE_RUN, polypath_phase_startmonitor,st); | |
843 | return; | |
844 | } | |
845 | ||
846 | start_subproc(st,privsep_socketpair,child_privsep, | |
847 | "socket generator (privsep interface handler)"); | |
848 | ||
849 | BUF_FREE(&st->lbuf); | |
850 | buffer_destroy(&st->lbuf); | |
851 | buffer_new(&st->lbuf,sizeof(struct privsep_mdata)); | |
852 | BUF_ALLOC(&st->lbuf,"polypath mdata buf"); | |
853 | st->privsep_incoming_fd=-1; | |
854 | ||
855 | register_for_poll(st,polypath_beforepoll, | |
856 | polypath_afterpoll_privsep,"polypath"); | |
857 | } | |
858 | ||
ce5c098f IJ |
859 | static void polypath_phase_shutdown(void *sst, uint32_t newphase) |
860 | { | |
861 | struct polypath *st=sst; | |
862 | if (st->monitor_pid) { | |
863 | assert(st->monitor_pid>0); | |
864 | kill(st->monitor_pid,SIGTERM); | |
865 | } | |
866 | } | |
867 | ||
32654a31 IJ |
868 | static void polypath_phase_childpersist(void *sst, uint32_t newphase) |
869 | { | |
870 | struct polypath *st=sst; | |
871 | struct interf *interf; | |
872 | ||
03cbfbd2 IJ |
873 | LIST_FOREACH(interf,&st->interfs_general,entry) |
874 | udp_socks_childpersist(&st->uc,&interf->socks); | |
875 | LIST_FOREACH(interf,&st->interfs_dedicated,entry) | |
32654a31 IJ |
876 | udp_socks_childpersist(&st->uc,&interf->socks); |
877 | } | |
878 | ||
70ad8e2c IJ |
879 | #undef BAD |
880 | #undef BADE | |
881 | ||
93cdea57 IJ |
882 | /*----- generic closure and module setup -----*/ |
883 | ||
ce5c098f IJ |
884 | static list_t *polypath_apply(closure_t *self, struct cloc loc, |
885 | dict_t *context, list_t *args) | |
886 | { | |
887 | struct polypath *st; | |
888 | ||
889 | COMM_APPLY(st,&st->uc.cc,polypath_,"polypath",loc); | |
890 | COMM_APPLY_STANDARD(st,&st->uc.cc,"polypath",args); | |
891 | UDP_APPLY_STANDARD(st,&st->uc,"polypath"); | |
892 | ||
03cbfbd2 IJ |
893 | st->uc.cc.ops.clientinfo = polypath_clientinfo; |
894 | ||
ce5c098f IJ |
895 | struct udpcommon *uc=&st->uc; |
896 | struct commcommon *cc=&uc->cc; | |
897 | ||
898 | st->max_interfs=dict_read_number(d,"max-interfaces",False,"polypath",loc,3); | |
899 | ||
900 | st->ifname_pats=dict_read_string_array(d,"interfaces",False,"polypath", | |
901 | cc->loc,0); | |
902 | st->permit_loopback=0; /* ifname_wanted reads this */ | |
903 | ifname_wanted(st,st->uc.cc.loc," "); /* try to check each pattern */ | |
904 | ||
905 | st->monitor_command=dict_read_string_array(d,"monitor-command",False, | |
906 | "polypath",cc->loc, default_monitor_command); | |
907 | if (!st->monitor_command[0]) | |
908 | cfgfatal(loc,"polypath","no polypath interface monitor-command" | |
909 | " (polypath unsupported on this platform?)\n"); | |
910 | ||
911 | st->permit_loopback=dict_read_bool(d,"permit-loopback",False, | |
912 | "polypath",cc->loc,False); | |
913 | ||
03cbfbd2 IJ |
914 | LIST_INIT(&st->interfs_general); |
915 | LIST_INIT(&st->interfs_dedicated); | |
ce5c098f IJ |
916 | buffer_new(&st->lbuf,ADNS_ADDR2TEXT_BUFLEN+100); |
917 | BUF_ALLOC(&st->lbuf,"polypath lbuf"); | |
918 | ||
919 | st->monitor_fd=-1; | |
920 | st->monitor_pid=0; | |
921 | ||
93cdea57 IJ |
922 | add_hook(PHASE_GETRESOURCES, polypath_phase_startprivsep,st); |
923 | ||
ce5c098f | 924 | add_hook(PHASE_SHUTDOWN, polypath_phase_shutdown, st); |
32654a31 | 925 | add_hook(PHASE_CHILDPERSIST,polypath_phase_childpersist,st); |
ce5c098f IJ |
926 | |
927 | return new_closure(&cc->cl); | |
928 | } | |
929 | ||
930 | #endif /* CONFIG_IPV6 */ | |
931 | ||
932 | void polypath_module(dict_t *dict) | |
933 | { | |
934 | #ifdef CONFIG_IPV6 | |
935 | add_closure(dict,"polypath",polypath_apply); | |
936 | #endif /* CONFIG_IPV6 */ | |
937 | } |