1 /* UDP send/receive module for secnet */
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
8 * Packets are offered to registered receivers in turn. Once one
9 * accepts it, it isn't offered to any more. */
17 #include <sys/socket.h>
19 #include <netinet/in.h>
20 #include <arpa/inet.h>
23 #include "unaligned.h"
26 #include "comm-common.h"
28 static comm_sendmsg_fn udp_sendmsg
;
32 struct udpsocks socks
;
33 bool_t addr_configured
;
38 * Re comm_addr.ix: This field allows us to note in the comm_addr
39 * which socket an incoming packet was received on. This is required
40 * for conveniently logging the actual source of a packet. But the ix
41 * does not formally form part of the address: it is not used when
42 * sending, nor when comparing two comm_addrs.
44 * The special value -1 means that the comm_addr was constructed by
45 * another module in secnet (eg the resolver), rather than being a
46 * description of the source of an incoming packet.
49 static const char *udp_addr_to_string(void *commst
, const struct comm_addr
*ca
)
51 struct udp
*st
=commst
;
52 struct udpsocks
*socks
=&st
->socks
;
53 static char sbuf
[100];
54 int ix
=ca
->ix
>=0 ? ca
->ix
: 0;
56 assert(ix
>=0 && ix
<socks
->n_socks
);
57 snprintf(sbuf
, sizeof(sbuf
), "udp#%u@l%d:%s%s-%s",
58 st
->counter
, st
->uc
.cc
.loc
.line
,
59 iaddr_to_string(&socks
->socks
[ix
].addr
),
60 ca
->ix
<0 && socks
->n_socks
>1 ?
"&" : "",
61 iaddr_to_string(&ca
->ia
));
65 static int udp_socks_beforepoll(void *state
, struct pollfd
*fds
, int *nfds_io
,
68 struct udpsocks
*socks
=state
;
70 BEFOREPOLL_WANT_FDS(socks
->n_socks
);
71 for (i
=0; i
<socks
->n_socks
; i
++) {
72 fds
[i
].fd
=socks
->socks
[i
].fd
;
78 const char *af_name(int af
)
81 case AF_INET6
: return "IPv6";
82 case AF_INET
: return "IPv4";
83 case 0: return "(any)";
88 void udp_sock_experienced(struct log_if
*lg
, struct udpcommon
*uc
,
89 struct udpsocks
*socks
, struct udpsock
*us
,
90 const union iaddr
*dest
, int af
,
94 if (us
->experienced
[!!dest
][af
][success
]++)
96 lg_perror(lg
, uc
->cc
.cl
.description
, &uc
->cc
.loc
,
97 success ? M_INFO
: M_WARNING
,
98 success ?
0 : errnoval
,
99 "%s %s experiencing some %s %s%s%s%s%s%s",
100 socks
->desc
,iaddr_to_string(&us
->addr
),
101 success?
"success":"trouble",
102 dest?
"transmitting":"receiving",
103 af?
" ":"", af?
af_name(af
):"",
105 dest?
iaddr_to_string(dest
):"",
109 static void udp_socks_afterpoll(void *state
, struct pollfd
*fds
, int nfds
)
111 struct udpsocks
*socks
=state
;
112 struct udpcommon
*uc
=socks
->uc
;
119 struct commcommon
*cc
=&uc
->cc
;
121 for (i
=0; i
<socks
->n_socks
; i
++) {
122 struct udpsock
*us
=&socks
->socks
[i
];
123 if (i
>=nfds
) continue;
124 if (!(fds
[i
].revents
& POLLIN
)) continue;
125 assert(fds
[i
].fd
== us
->fd
);
128 fromlen
=sizeof(from
);
129 BUF_ASSERT_FREE(cc
->rbuf
);
130 BUF_ALLOC(cc
->rbuf
,"udp_afterpoll");
131 buffer_init(cc
->rbuf
,calculate_max_start_pad());
132 rv
=recvfrom(fd
, cc
->rbuf
->start
,
133 buf_remaining_space(cc
->rbuf
),
134 0, &from
.sa
, &fromlen
);
138 /* Check that the packet came from our poxy server;
139 we shouldn't be contacted directly by anybody else
140 (since they can trivially forge source addresses) */
141 if (!iaddr_equal(&from
,&uc
->proxy
,False
)) {
142 Message(M_INFO
,"udp: received packet that's not "
147 /* proxy protocol supports ipv4 transport only */
148 from
.sa
.sa_family
=AF_INET
;
149 BUF_GET_BYTES(unprepend
,cc
->rbuf
,&from
.sin
.sin_addr
,4);
150 buf_unprepend(cc
->rbuf
,2);
151 BUF_GET_BYTES(unprepend
,cc
->rbuf
,&from
.sin
.sin_port
,2);
157 done
=comm_notify(&cc
->notify
, cc
->rbuf
, &ca
);
159 udp_sock_experienced(0,uc
,socks
,us
,0,
160 from
.sa
.sa_family
,0,0);
163 if (cc
->rbuf
->size
>12 /* prevents traffic amplification */
164 && ((msgtype
=get_uint32(cc
->rbuf
->start
+8))
166 uint32_t source
,dest
;
167 /* Manufacture and send NAK packet */
168 source
=get_uint32(cc
->rbuf
->start
); /* Us */
169 dest
=get_uint32(cc
->rbuf
->start
+4); /* Them */
170 send_nak(&ca
,source
,dest
,msgtype
,cc
->rbuf
,"unwanted");
174 BUF_ASSERT_FREE(cc
->rbuf
);
176 if (errno
!=EINTR
&& !iswouldblock(errno
))
177 udp_sock_experienced(0,uc
,socks
,us
, 0,0, rv
,errno
);
184 static bool_t
udp_sendmsg(void *commst
, struct buffer_if
*buf
,
185 const struct comm_addr
*dest
)
187 struct udp
*st
=commst
;
188 struct udpcommon
*uc
=&st
->uc
;
189 struct udpsocks
*socks
=&st
->socks
;
193 struct udpsock
*us
=&socks
->socks
[0];
194 sa
=buf_prepend(buf
,8);
195 if (dest
->ia
.sa
.sa_family
!= AF_INET
) {
197 "udp: proxy means dropping outgoing non-IPv4 packet to %s\n",
198 iaddr_to_string(&dest
->ia
));
201 memcpy(sa
,&dest
->ia
.sin
.sin_addr
,4);
203 memcpy(sa
+6,&dest
->ia
.sin
.sin_port
,2);
204 int r
=sendto(us
->fd
,sa
,buf
->size
+8,0,&uc
->proxy
.sa
,
205 iaddr_socklen(&uc
->proxy
));
206 udp_sock_experienced(0,uc
,socks
,us
, &dest
->ia
,0, r
,errno
);
207 buf_unprepend(buf
,8);
210 bool_t allunsupported
=True
;
211 int af
=dest
->ia
.sa
.sa_family
;
212 for (i
=0; i
<socks
->n_socks
; i
++) {
213 struct udpsock
*us
=&socks
->socks
[i
];
214 if (us
->addr
.sa
.sa_family
!= af
)
215 /* no point even trying */
217 r
=sendto(us
->fd
, buf
->start
, buf
->size
, 0,
218 &dest
->ia
.sa
, iaddr_socklen(&dest
->ia
));
219 udp_sock_experienced(0,uc
,socks
,us
, &dest
->ia
,af
, r
,errno
);
220 if (r
>=0) return True
;
221 if (!(errno
==EAFNOSUPPORT
|| errno
==ENETUNREACH
))
222 /* who knows what that error means? */
223 allunsupported
=False
;
225 return !allunsupported
; /* see doc for comm_sendmsg_fn in secnet.h */
231 void udp_destroy_socket(struct udpcommon
*uc
, struct udpsock
*us
)
239 #define FAIL_LG 0, cc->cl.description, &cc->loc, failmsgclass
240 #define FAIL(...) do{ \
241 lg_perror(FAIL_LG,errno,__VA_ARGS__); \
245 static bool_t
record_socket_gotaddr(struct udpcommon
*uc
, struct udpsock
*us
,
248 struct commcommon
*cc
=&uc
->cc
;
249 socklen_t salen
=sizeof(us
->addr
);
250 int r
=getsockname(us
->fd
,&us
->addr
.sa
,&salen
);
251 if (r
) FAIL("getsockname()");
252 if (salen
>sizeof(us
->addr
)) { errno
=0; FAIL("getsockname() length"); }
259 bool_t
udp_import_socket(struct udpcommon
*uc
, struct udpsock
*us
,
260 int failmsgclass
, int fd
)
262 FILLZERO(us
->experienced
);
264 return record_socket_gotaddr(uc
,us
,failmsgclass
);
267 bool_t
udp_make_socket(struct udpcommon
*uc
, struct udpsock
*us
,
270 const union iaddr
*addr
=&us
->addr
;
271 struct commcommon
*cc
=&uc
->cc
;
274 FILLZERO(us
->experienced
);
275 us
->fd
=socket(addr
->sa
.sa_family
, SOCK_DGRAM
, IPPROTO_UDP
);
276 if (us
->fd
<0) FAIL("socket");
280 if (addr
->sa
.sa_family
==AF_INET6
) {
283 socklen_t optlen
=sizeof(optval
);
284 r
=setsockopt(us
->fd
,IPPROTO_IPV6
,IPV6_V6ONLY
,&optval
,optlen
);
285 if (r
) FAIL("setsockopt(,IPV6_V6ONLY,&1,)");
293 snprintf(desc
,sizeof(desc
),"authbind for %s: %s",
294 iaddr_to_string(addr
), uc
->authbind
);
296 /* XXX this fork() and waitpid() business needs to be hidden
297 in some system-specific library functions. */
300 FAIL("fork() for authbind");
302 char *argv
[5], addrstr
[33], portstr
[5];
306 switch (addr
->sa
.sa_family
) {
308 sprintf(addrstr
,"%08lX",(long)addr
->sin
.sin_addr
.s_addr
);
309 port
=addr
->sin
.sin_port
;
316 sprintf(addrstr
+i
*2,"%02X",addr
->sin6
.sin6_addr
.s6_addr
[i
]);
317 port
=addr
->sin6
.sin6_port
;
321 #endif /*CONFIG_IPV6*/
323 fatal("udp (%s:%d): unsupported address family for authbind",
324 cc
->loc
.file
,cc
->loc
.line
);
326 sprintf(portstr
,"%04X",port
);
327 argv
[0]=uc
->authbind
;
330 argv
[3]=(char*)addrfam
;
333 execvp(uc
->authbind
,argv
);
336 while (waitpid(c
,&status
,0)==-1) {
337 if (errno
==EINTR
) continue;
338 FAIL("waitpid for authbind");
341 if (WIFEXITED(status
) && WEXITSTATUS(status
)<127) {
342 int es
=WEXITSTATUS(status
);
343 lg_perror(FAIL_LG
,es
,
344 "%s exited with error exit status %d;"
345 " indicates error",desc
,es
);
347 lg_exitstatus(FAIL_LG
,status
,desc
);
352 if (bind(us
->fd
, &addr
->sa
, iaddr_socklen(addr
))!=0)
353 FAIL("bind (%s)",iaddr_to_string(addr
));
356 bool_t ok
=record_socket_gotaddr(uc
,us
,failmsgclass
);
357 if (!ok
) goto failed
;
362 udp_destroy_socket(uc
,us
);
368 void udp_socks_register(struct udpcommon
*uc
, struct udpsocks
*socks
,
374 register_for_poll(socks
,udp_socks_beforepoll
,udp_socks_afterpoll
,"udp");
377 void udp_socks_deregister(struct udpcommon
*uc
, struct udpsocks
*socks
)
380 deregister_for_poll(socks
->interest
);
383 void udp_socks_childpersist(struct udpcommon
*uc
, struct udpsocks
*socks
)
386 for (i
=0; i
<socks
->n_socks
; i
++)
387 udp_destroy_socket(uc
,&socks
->socks
[i
]);
390 static void udp_childpersist_hook(void *sst
, uint32_t new_phase
)
393 udp_socks_childpersist(&st
->uc
,&st
->socks
);
396 static void udp_phase_hook(void *sst
, uint32_t new_phase
)
399 struct udpsocks
*socks
=&st
->socks
;
400 struct udpcommon
*uc
=&st
->uc
;
404 for (i
=0; i
<socks
->n_socks
; i
++) {
405 bool_t required
=st
->addr_configured
406 || (!anydone
&& i
==socks
->n_socks
-1);
407 anydone
+= udp_make_socket(uc
,&socks
->socks
[i
],
408 required ? M_FATAL
: M_WARNING
);
411 udp_socks_register(uc
,socks
, uc
->use_proxy ?
"proxy" : "socket");
413 add_hook(PHASE_CHILDPERSIST
,udp_childpersist_hook
,st
);
416 static list_t
*udp_apply(closure_t
*self
, struct cloc loc
, dict_t
*context
,
419 static unsigned counter
;
427 COMM_APPLY(st
,&st
->uc
.cc
,udp_
,"udp",loc
);
428 COMM_APPLY_STANDARD(st
,&st
->uc
.cc
,"udp",args
);
429 UDP_APPLY_STANDARD(st
,&st
->uc
,"udp");
431 struct udpcommon
*uc
=&st
->uc
;
432 struct udpsocks
*socks
=&st
->socks
;
433 struct commcommon
*cc
=&uc
->cc
;
435 st
->counter
=counter
++;
437 union iaddr defaultaddrs
[] = {
439 { .sin6
= { .sin6_family
=AF_INET6
,
440 .sin6_port
=htons(uc
->port
),
441 .sin6_addr
=IN6ADDR_ANY_INIT
} },
443 { .sin
= { .sin_family
=AF_INET
,
444 .sin_port
=htons(uc
->port
),
445 .sin_addr
= { .s_addr
=INADDR_ANY
} } }
448 caddrl
=dict_lookup(d
,"address");
449 st
->addr_configured
=!!caddrl
;
450 socks
->n_socks
=st
->addr_configured ?
list_length(caddrl
)
451 : (int)ARRAY_SIZE(defaultaddrs
);
452 if (socks
->n_socks
<=0 || socks
->n_socks
>UDP_MAX_SOCKETS
)
453 cfgfatal(cc
->loc
,"udp","`address' must be 1..%d addresses",
456 for (i
=0; i
<socks
->n_socks
; i
++) {
457 struct udpsock
*us
=&socks
->socks
[i
];
458 if (!st
->addr_configured
) {
459 us
->addr
=defaultaddrs
[i
];
461 string_item_to_iaddr(list_elem(caddrl
,i
),uc
->port
,&us
->addr
,"udp");
466 l
=dict_lookup(d
,"proxy");
469 uc
->proxy
.sa
.sa_family
=AF_INET
;
471 if (!item
|| item
->type
!=t_string
) {
472 cfgfatal(cc
->loc
,"udp","proxy must supply ""addr"",port\n");
474 a
=string_item_to_ipaddr(item
,"proxy");
475 uc
->proxy
.sin
.sin_addr
.s_addr
=htonl(a
);
477 if (!item
|| item
->type
!=t_number
) {
478 cfgfatal(cc
->loc
,"udp","proxy must supply ""addr"",port\n");
480 uc
->proxy
.sin
.sin_port
=htons(item
->data
.number
);
483 update_max_start_pad(&comm_max_start_pad
, uc
->use_proxy ?
8 : 0);
485 add_hook(PHASE_GETRESOURCES
,udp_phase_hook
,st
);
487 return new_closure(&cc
->cl
);
490 void udp_module(dict_t
*dict
)
492 add_closure(dict
,"udp",udp_apply
);