Commit | Line | Data |
---|---|---|
2fe58dfd SE |
1 | /* UDP send/receive module for secnet */ |
2 | ||
3 | /* This module enables sites to communicate by sending UDP | |
4 | * packets. When an instance of the module is created we can | |
5 | * optionally bind to a particular local IP address (not implemented | |
6 | * yet). | |
7 | * | |
2fe58dfd SE |
8 | * Packets are offered to registered receivers in turn. Once one |
9 | * accepts it, it isn't offered to any more. */ | |
10 | ||
8689b3a9 | 11 | #include "secnet.h" |
2fe58dfd SE |
12 | #include <stdio.h> |
13 | #include <unistd.h> | |
14 | #include <fcntl.h> | |
15 | #include <string.h> | |
16 | #include <errno.h> | |
2fe58dfd | 17 | #include <sys/socket.h> |
b2a56f7c | 18 | #include <sys/wait.h> |
5edf478f IJ |
19 | #include <netinet/in.h> |
20 | #include <arpa/inet.h> | |
2fe58dfd | 21 | #include "util.h" |
dd9209d1 | 22 | #include "magic.h" |
794f2398 | 23 | #include "unaligned.h" |
ff05a229 | 24 | #include "ipaddr.h" |
136740e6 | 25 | #include "magic.h" |
54d5ef00 | 26 | #include "comm-common.h" |
2fe58dfd | 27 | |
2fe58dfd SE |
28 | static comm_sendmsg_fn udp_sendmsg; |
29 | ||
2fe58dfd | 30 | struct udp { |
763e458f IJ |
31 | struct udpcommon uc; |
32 | struct udpsocks socks; | |
2fe58dfd SE |
33 | }; |
34 | ||
08b62a6c IJ |
35 | /* |
36 | * Re comm_addr.ix: This field allows us to note in the comm_addr | |
37 | * which socket an incoming packet was received on. This is required | |
38 | * for conveniently logging the actual source of a packet. But the ix | |
39 | * does not formally form part of the address: it is not used when | |
40 | * sending, nor when comparing two comm_addrs. | |
41 | * | |
42 | * The special value -1 means that the comm_addr was constructed by | |
43 | * another module in secnet (eg the resolver), rather than being a | |
44 | * description of the source of an incoming packet. | |
45 | */ | |
46 | ||
54d5ef00 IJ |
47 | static const char *udp_addr_to_string(void *commst, const struct comm_addr *ca) |
48 | { | |
5edf478f | 49 | struct udp *st=commst; |
763e458f | 50 | struct udpsocks *socks=&st->socks; |
5edf478f | 51 | static char sbuf[100]; |
08b62a6c | 52 | int ix=ca->ix>=0 ? ca->ix : 0; |
5edf478f | 53 | |
7d31df0e | 54 | assert(ix>=0 && ix<socks->n_socks); |
08b62a6c | 55 | snprintf(sbuf, sizeof(sbuf), "udp:%s%s-%s", |
7d31df0e | 56 | iaddr_to_string(&socks->socks[ix].addr), |
08b62a6c IJ |
57 | ca->ix<0 ? "&" : "", |
58 | iaddr_to_string(&ca->ia)); | |
5edf478f IJ |
59 | return sbuf; |
60 | } | |
61 | ||
f7af3192 IJ |
62 | static int udp_socks_beforepoll(void *state, struct pollfd *fds, int *nfds_io, |
63 | int *timeout_io) | |
2fe58dfd | 64 | { |
f7af3192 | 65 | struct udpsocks *socks=state; |
08b62a6c | 66 | int i; |
7d31df0e IJ |
67 | BEFOREPOLL_WANT_FDS(socks->n_socks); |
68 | for (i=0; i<socks->n_socks; i++) { | |
69 | fds[i].fd=socks->socks[i].fd; | |
08b62a6c IJ |
70 | fds[i].events=POLLIN; |
71 | } | |
2fe58dfd SE |
72 | return 0; |
73 | } | |
74 | ||
2d7478f7 IJ |
75 | const char *af_name(int af) |
76 | { | |
77 | switch (af) { | |
78 | case AF_INET6: return "IPv6"; | |
79 | case AF_INET: return "IPv4"; | |
80 | case 0: return "(any)"; | |
81 | default: abort(); | |
82 | } | |
83 | } | |
84 | ||
85 | void udp_sock_experienced(struct log_if *lg, struct udpcommon *uc, | |
86 | const char *socksdesc, struct udpsock *us, | |
87 | bool_t recvsend, int af, | |
88 | int r, int errnoval) | |
89 | { | |
90 | bool_t success=r>=0; | |
91 | if (us->experienced[recvsend][af][success]++) | |
92 | return; | |
93 | lg_perror(lg, uc->cc.cl.description, &uc->cc.loc, | |
94 | success ? M_INFO : M_WARNING, | |
95 | success ? 0 : errnoval, | |
96 | "%s %s experiencing some %s %s%s%s", | |
97 | socksdesc,iaddr_to_string(&us->addr), | |
98 | success?"success":"trouble", | |
99 | recvsend?"transmitting":"receiving", | |
100 | af?" ":"", af?af_name(af):""); | |
101 | } | |
102 | ||
f7af3192 | 103 | static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds) |
763e458f | 104 | { |
f7af3192 IJ |
105 | struct udpsocks *socks=state; |
106 | struct udpcommon *uc=socks->uc; | |
a32d56fb | 107 | union iaddr from; |
b1a0f651 | 108 | socklen_t fromlen; |
2fe58dfd SE |
109 | bool_t done; |
110 | int rv; | |
08b62a6c | 111 | int i; |
2fe58dfd | 112 | |
763e458f IJ |
113 | struct commcommon *cc=&uc->cc; |
114 | ||
115 | for (i=0; i<socks->n_socks; i++) { | |
56c8ed69 | 116 | struct udpsock *us=&socks->socks[i]; |
08b62a6c IJ |
117 | if (i>=nfds) continue; |
118 | if (!(fds[i].revents & POLLIN)) continue; | |
56c8ed69 IJ |
119 | assert(fds[i].fd == us->fd); |
120 | int fd=us->fd; | |
2fe58dfd SE |
121 | do { |
122 | fromlen=sizeof(from); | |
7d31df0e IJ |
123 | BUF_ASSERT_FREE(cc->rbuf); |
124 | BUF_ALLOC(cc->rbuf,"udp_afterpoll"); | |
125 | buffer_init(cc->rbuf,calculate_max_start_pad()); | |
126 | rv=recvfrom(fd, cc->rbuf->start, | |
127 | buf_remaining_space(cc->rbuf), | |
a32d56fb | 128 | 0, &from.sa, &fromlen); |
2fe58dfd | 129 | if (rv>0) { |
7d31df0e IJ |
130 | cc->rbuf->size=rv; |
131 | if (uc->use_proxy) { | |
ff05a229 SE |
132 | /* Check that the packet came from our poxy server; |
133 | we shouldn't be contacted directly by anybody else | |
134 | (since they can trivially forge source addresses) */ | |
7d31df0e | 135 | if (!iaddr_equal(&from,&uc->proxy)) { |
ff05a229 SE |
136 | Message(M_INFO,"udp: received packet that's not " |
137 | "from the proxy\n"); | |
7d31df0e | 138 | BUF_FREE(cc->rbuf); |
ff05a229 SE |
139 | continue; |
140 | } | |
a32d56fb IJ |
141 | /* proxy protocol supports ipv4 transport only */ |
142 | from.sa.sa_family=AF_INET; | |
c1ddd026 | 143 | BUF_GET_BYTES(unprepend,cc->rbuf,&from.sin.sin_addr,4); |
7d31df0e | 144 | buf_unprepend(cc->rbuf,2); |
c1ddd026 | 145 | BUF_GET_BYTES(unprepend,cc->rbuf,&from.sin.sin_port,2); |
ff05a229 | 146 | } |
8534d602 | 147 | struct comm_addr ca; |
7d31df0e | 148 | ca.comm=&cc->ops; |
a32d56fb | 149 | ca.ia=from; |
08b62a6c | 150 | ca.ix=i; |
54d5ef00 | 151 | done=comm_notify(&cc->notify, cc->rbuf, &ca); |
2fe58dfd | 152 | if (!done) { |
bf28fc73 | 153 | uint32_t msgtype; |
7d31df0e IJ |
154 | if (cc->rbuf->size>12 /* prevents traffic amplification */ |
155 | && ((msgtype=get_uint32(cc->rbuf->start+8)) | |
bf28fc73 IJ |
156 | != LABEL_NAK)) { |
157 | uint32_t source,dest; | |
158 | /* Manufacture and send NAK packet */ | |
7d31df0e IJ |
159 | source=get_uint32(cc->rbuf->start); /* Us */ |
160 | dest=get_uint32(cc->rbuf->start+4); /* Them */ | |
161 | send_nak(&ca,source,dest,msgtype,cc->rbuf,"unwanted"); | |
bf28fc73 | 162 | } |
7d31df0e | 163 | BUF_FREE(cc->rbuf); |
2fe58dfd | 164 | } |
7d31df0e | 165 | BUF_ASSERT_FREE(cc->rbuf); |
56c8ed69 | 166 | } else { /* rv<=0 */ |
2d7478f7 IJ |
167 | if (errno!=EINTR && !iswouldblock(errno)) |
168 | udp_sock_experienced(0,uc, "socket",us, 0,0, rv,errno); | |
7d31df0e | 169 | BUF_FREE(cc->rbuf); |
2fe58dfd SE |
170 | } |
171 | } while (rv>=0); | |
172 | } | |
173 | } | |
174 | ||
2fe58dfd | 175 | static bool_t udp_sendmsg(void *commst, struct buffer_if *buf, |
a15faeb2 | 176 | const struct comm_addr *dest) |
2fe58dfd SE |
177 | { |
178 | struct udp *st=commst; | |
763e458f IJ |
179 | struct udpcommon *uc=&st->uc; |
180 | struct udpsocks *socks=&st->socks; | |
ff05a229 | 181 | uint8_t *sa; |
2fe58dfd | 182 | |
7d31df0e | 183 | if (uc->use_proxy) { |
56c8ed69 | 184 | struct udpsock *us=&socks->socks[0]; |
3abd18e8 | 185 | sa=buf_prepend(buf,8); |
a32d56fb IJ |
186 | if (dest->ia.sa.sa_family != AF_INET) { |
187 | Message(M_INFO, | |
188 | "udp: proxy means dropping outgoing non-IPv4 packet to %s\n", | |
189 | iaddr_to_string(&dest->ia)); | |
190 | return False; | |
191 | } | |
192 | memcpy(sa,&dest->ia.sin.sin_addr,4); | |
ff05a229 | 193 | memset(sa+4,0,4); |
a32d56fb | 194 | memcpy(sa+6,&dest->ia.sin.sin_port,2); |
2d7478f7 | 195 | int r=sendto(us->fd,sa,buf->size+8,0,&uc->proxy.sa, |
7d31df0e | 196 | iaddr_socklen(&uc->proxy)); |
2d7478f7 | 197 | udp_sock_experienced(0,uc, "proxy",us, 1,0, r,errno); |
3abd18e8 | 198 | buf_unprepend(buf,8); |
ff05a229 | 199 | } else { |
08b62a6c IJ |
200 | int i,r; |
201 | bool_t allunsupported=True; | |
56c8ed69 | 202 | int af=dest->ia.sa.sa_family; |
7d31df0e | 203 | for (i=0; i<socks->n_socks; i++) { |
56c8ed69 IJ |
204 | struct udpsock *us=&socks->socks[i]; |
205 | if (us->addr.sa.sa_family != af) | |
08b62a6c IJ |
206 | /* no point even trying */ |
207 | continue; | |
56c8ed69 | 208 | r=sendto(us->fd, buf->start, buf->size, 0, |
08b62a6c | 209 | &dest->ia.sa, iaddr_socklen(&dest->ia)); |
2d7478f7 | 210 | udp_sock_experienced(0,uc, "socket",us, 1,af, r,errno); |
08b62a6c IJ |
211 | if (r>=0) return True; |
212 | if (!(errno==EAFNOSUPPORT || errno==ENETUNREACH)) | |
213 | /* who knows what that error means? */ | |
214 | allunsupported=False; | |
215 | } | |
216 | return !allunsupported; /* see doc for comm_sendmsg_fn in secnet.h */ | |
ff05a229 | 217 | } |
2fe58dfd SE |
218 | |
219 | return True; | |
220 | } | |
221 | ||
5f8b7a8e IJ |
222 | void udp_destroy_socket(struct udpcommon *uc, struct udpsock *us) |
223 | { | |
224 | if (us->fd>=0) { | |
225 | close(us->fd); | |
226 | us->fd=-1; | |
227 | } | |
228 | } | |
229 | ||
53f4e666 IJ |
230 | bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us, |
231 | int failmsgclass) | |
baa06aeb | 232 | { |
f164f167 | 233 | const union iaddr *addr=&us->addr; |
763e458f | 234 | struct commcommon *cc=&uc->cc; |
53f4e666 IJ |
235 | us->fd=-1; |
236 | ||
237 | #define FAIL_LG 0, cc->cl.description, &cc->loc, failmsgclass | |
238 | #define FAIL(...) do{ \ | |
239 | lg_perror(FAIL_LG,errno,__VA_ARGS__); \ | |
240 | goto failed; \ | |
241 | }while(0) | |
763e458f | 242 | |
2d7478f7 | 243 | FILLZERO(us->experienced); |
08b62a6c | 244 | us->fd=socket(addr->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP); |
53f4e666 | 245 | if (us->fd<0) FAIL("socket"); |
f54d5ada | 246 | setnonblock(us->fd); |
f164f167 | 247 | setcloexec(us->fd); |
08b62a6c IJ |
248 | #ifdef CONFIG_IPV6 |
249 | if (addr->sa.sa_family==AF_INET6) { | |
250 | int r; | |
251 | int optval=1; | |
252 | socklen_t optlen=sizeof(optval); | |
253 | r=setsockopt(us->fd,IPPROTO_IPV6,IPV6_V6ONLY,&optval,optlen); | |
53f4e666 | 254 | if (r) FAIL("setsockopt(,IPV6_V6ONLY,&1,)"); |
08b62a6c IJ |
255 | } |
256 | #endif | |
baa06aeb | 257 | |
7d31df0e | 258 | if (uc->authbind) { |
b2a56f7c SE |
259 | pid_t c; |
260 | int status; | |
261 | ||
262 | /* XXX this fork() and waitpid() business needs to be hidden | |
263 | in some system-specific library functions. */ | |
264 | c=fork(); | |
53f4e666 IJ |
265 | if (c==-1) |
266 | FAIL("fork() for authbind"); | |
b2a56f7c | 267 | if (c==0) { |
3ff31eda IJ |
268 | char *argv[5], addrstr[33], portstr[5]; |
269 | const char *addrfam; | |
270 | int port; | |
5e7a5e2d | 271 | afterfork(); |
f164f167 | 272 | switch (addr->sa.sa_family) { |
a32d56fb | 273 | case AF_INET: |
f164f167 | 274 | sprintf(addrstr,"%08lX",(long)addr->sin.sin_addr.s_addr); |
3ff31eda IJ |
275 | port=addr->sin.sin_port; |
276 | addrfam=NULL; | |
a32d56fb | 277 | break; |
3ff31eda IJ |
278 | #ifdef CONFIG_IPV6 |
279 | case AF_INET6: { | |
280 | int i; | |
281 | for (i=0; i<16; i++) | |
282 | sprintf(addrstr+i*2,"%02X",addr->sin6.sin6_addr.s6_addr[i]); | |
283 | port=addr->sin6.sin6_port; | |
284 | addrfam="6"; | |
285 | break; | |
286 | } | |
287 | #endif /*CONFIG_IPV6*/ | |
a32d56fb IJ |
288 | default: |
289 | fatal("udp (%s:%d): unsupported address family for authbind", | |
7d31df0e | 290 | cc->loc.file,cc->loc.line); |
a32d56fb | 291 | } |
3ff31eda | 292 | sprintf(portstr,"%04X",port); |
7d31df0e | 293 | argv[0]=uc->authbind; |
3b83c932 SE |
294 | argv[1]=addrstr; |
295 | argv[2]=portstr; | |
3ff31eda IJ |
296 | argv[3]=(char*)addrfam; |
297 | argv[4]=NULL; | |
f164f167 | 298 | dup2(us->fd,0); |
7d31df0e | 299 | execvp(uc->authbind,argv); |
3b83c932 | 300 | _exit(255); |
b2a56f7c | 301 | } |
3b83c932 SE |
302 | while (waitpid(c,&status,0)==-1) { |
303 | if (errno==EINTR) continue; | |
53f4e666 | 304 | FAIL("waitpid for authbind"); |
b2a56f7c | 305 | } |
4ac7fd3f | 306 | if (status) { |
313e4f0f IJ |
307 | if (WIFEXITED(status) && WEXITSTATUS(status)<127) { |
308 | int es=WEXITSTATUS(status); | |
309 | lg_perror(FAIL_LG,es, | |
310 | "authbind exited with error exit status %d;" | |
311 | " indicates error",es); | |
312 | } else { | |
313 | lg_exitstatus(FAIL_LG,status,"authbind"); | |
314 | } | |
53f4e666 | 315 | goto failed; |
3b83c932 | 316 | } |
b2a56f7c | 317 | } else { |
53f4e666 IJ |
318 | if (bind(us->fd, &addr->sa, iaddr_socklen(addr))!=0) |
319 | FAIL("bind (%s)",iaddr_to_string(addr)); | |
baa06aeb | 320 | } |
53f4e666 IJ |
321 | return True; |
322 | ||
323 | failed: | |
5f8b7a8e | 324 | udp_destroy_socket(uc,us); |
53f4e666 IJ |
325 | return False; |
326 | ||
327 | #undef FAIL | |
f164f167 | 328 | } |
baa06aeb | 329 | |
f7af3192 IJ |
330 | void udp_socks_register(struct udpcommon *uc, struct udpsocks *socks) |
331 | { | |
332 | socks->uc=uc; | |
5c679ae0 IJ |
333 | socks->interest= |
334 | register_for_poll(socks,udp_socks_beforepoll,udp_socks_afterpoll,"udp"); | |
335 | } | |
336 | ||
337 | void udp_socks_deregister(struct udpcommon *uc, struct udpsocks *socks) | |
338 | { | |
339 | socks->uc=uc; | |
340 | deregister_for_poll(socks->interest); | |
f7af3192 IJ |
341 | } |
342 | ||
f164f167 IJ |
343 | static void udp_phase_hook(void *sst, uint32_t new_phase) |
344 | { | |
345 | struct udp *st=sst; | |
763e458f | 346 | struct udpsocks *socks=&st->socks; |
f7af3192 | 347 | struct udpcommon *uc=&st->uc; |
08b62a6c | 348 | int i; |
7d31df0e | 349 | for (i=0; i<socks->n_socks; i++) |
53f4e666 | 350 | udp_make_socket(uc,&socks->socks[i],M_FATAL); |
08b62a6c | 351 | |
f7af3192 | 352 | udp_socks_register(uc,socks); |
baa06aeb SE |
353 | } |
354 | ||
2fe58dfd SE |
355 | static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context, |
356 | list_t *args) | |
357 | { | |
358 | struct udp *st; | |
08b62a6c | 359 | list_t *caddrl; |
ff05a229 SE |
360 | list_t *l; |
361 | uint32_t a; | |
08b62a6c | 362 | int i; |
2fe58dfd | 363 | |
763e458f IJ |
364 | COMM_APPLY(st,&st->uc.cc,udp_,"udp",loc); |
365 | COMM_APPLY_STANDARD(st,&st->uc.cc,"udp",args); | |
366 | UDP_APPLY_STANDARD(st,&st->uc,"udp"); | |
2fe58dfd | 367 | |
763e458f IJ |
368 | struct udpcommon *uc=&st->uc; |
369 | struct udpsocks *socks=&st->socks; | |
370 | struct commcommon *cc=&uc->cc; | |
08b62a6c IJ |
371 | |
372 | union iaddr defaultaddrs[] = { | |
373 | #ifdef CONFIG_IPV6 | |
374 | { .sin6 = { .sin6_family=AF_INET6, | |
763e458f | 375 | .sin6_port=htons(uc->port), |
08b62a6c IJ |
376 | .sin6_addr=IN6ADDR_ANY_INIT } }, |
377 | #endif | |
378 | { .sin = { .sin_family=AF_INET, | |
763e458f | 379 | .sin_port=htons(uc->port), |
08b62a6c IJ |
380 | .sin_addr= { .s_addr=INADDR_ANY } } } |
381 | }; | |
382 | ||
383 | caddrl=dict_lookup(d,"address"); | |
7d31df0e IJ |
384 | socks->n_socks=caddrl ? list_length(caddrl) : (int)ARRAY_SIZE(defaultaddrs); |
385 | if (socks->n_socks<=0 || socks->n_socks>UDP_MAX_SOCKETS) | |
386 | cfgfatal(cc->loc,"udp","`address' must be 1..%d addresses", | |
387 | UDP_MAX_SOCKETS); | |
08b62a6c | 388 | |
7d31df0e IJ |
389 | for (i=0; i<socks->n_socks; i++) { |
390 | struct udpsock *us=&socks->socks[i]; | |
08b62a6c IJ |
391 | if (!list_length(caddrl)) { |
392 | us->addr=defaultaddrs[i]; | |
393 | } else { | |
763e458f | 394 | string_item_to_iaddr(list_elem(caddrl,i),uc->port,&us->addr,"udp"); |
08b62a6c IJ |
395 | } |
396 | us->fd=-1; | |
397 | } | |
398 | ||
ff05a229 SE |
399 | l=dict_lookup(d,"proxy"); |
400 | if (l) { | |
7d31df0e IJ |
401 | uc->use_proxy=True; |
402 | uc->proxy.sa.sa_family=AF_INET; | |
c649eafe IJ |
403 | item=list_elem(l,0); |
404 | if (!item || item->type!=t_string) { | |
7d31df0e | 405 | cfgfatal(cc->loc,"udp","proxy must supply ""addr"",port\n"); |
ff05a229 | 406 | } |
c649eafe | 407 | a=string_item_to_ipaddr(item,"proxy"); |
7d31df0e | 408 | uc->proxy.sin.sin_addr.s_addr=htonl(a); |
c649eafe IJ |
409 | item=list_elem(l,1); |
410 | if (!item || item->type!=t_number) { | |
7d31df0e | 411 | cfgfatal(cc->loc,"udp","proxy must supply ""addr"",port\n"); |
ff05a229 | 412 | } |
7d31df0e | 413 | uc->proxy.sin.sin_port=htons(item->data.number); |
ff05a229 | 414 | } |
2fe58dfd | 415 | |
7d31df0e | 416 | update_max_start_pad(&comm_max_start_pad, uc->use_proxy ? 8 : 0); |
3abd18e8 | 417 | |
baa06aeb | 418 | add_hook(PHASE_GETRESOURCES,udp_phase_hook,st); |
2fe58dfd | 419 | |
7d31df0e | 420 | return new_closure(&cc->cl); |
2fe58dfd SE |
421 | } |
422 | ||
2fe58dfd SE |
423 | void udp_module(dict_t *dict) |
424 | { | |
425 | add_closure(dict,"udp",udp_apply); | |
426 | } |