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f0cbd3ec FB |
1 | #include "slirp.h" |
2 | ||
3 | /* host address */ | |
4 | struct in_addr our_addr; | |
5 | /* host dns address */ | |
6 | struct in_addr dns_addr; | |
7 | /* host loopback address */ | |
8 | struct in_addr loopback_addr; | |
9 | ||
10 | /* address for slirp virtual addresses */ | |
11 | struct in_addr special_addr; | |
12 | ||
13 | const uint8_t special_ethaddr[6] = { | |
14 | 0x52, 0x54, 0x00, 0x12, 0x35, 0x00 | |
15 | }; | |
16 | ||
17 | uint8_t client_ethaddr[6]; | |
18 | ||
19 | int do_slowtimo; | |
20 | int link_up; | |
21 | struct timeval tt; | |
22 | FILE *lfd; | |
23 | ||
24 | /* XXX: suppress those select globals */ | |
25 | fd_set *global_readfds, *global_writefds, *global_xfds; | |
26 | ||
27 | #ifdef _WIN32 | |
28 | ||
29 | static int get_dns_addr(struct in_addr *pdns_addr) | |
30 | { | |
31 | /* XXX: add it */ | |
32 | return -1; | |
33 | } | |
34 | ||
35 | #else | |
36 | ||
37 | static int get_dns_addr(struct in_addr *pdns_addr) | |
38 | { | |
39 | char buff[512]; | |
40 | char buff2[256]; | |
41 | FILE *f; | |
42 | int found = 0; | |
43 | struct in_addr tmp_addr; | |
44 | ||
45 | f = fopen("/etc/resolv.conf", "r"); | |
46 | if (!f) | |
47 | return -1; | |
48 | ||
49 | lprint("IP address of your DNS(s): "); | |
50 | while (fgets(buff, 512, f) != NULL) { | |
51 | if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) { | |
52 | if (!inet_aton(buff2, &tmp_addr)) | |
53 | continue; | |
54 | if (tmp_addr.s_addr == loopback_addr.s_addr) | |
55 | tmp_addr = our_addr; | |
56 | /* If it's the first one, set it to dns_addr */ | |
57 | if (!found) | |
58 | *pdns_addr = tmp_addr; | |
59 | else | |
60 | lprint(", "); | |
61 | if (++found > 3) { | |
62 | lprint("(more)"); | |
63 | break; | |
64 | } else | |
65 | lprint("%s", inet_ntoa(tmp_addr)); | |
66 | } | |
67 | } | |
68 | if (!found) | |
69 | return -1; | |
70 | return 0; | |
71 | } | |
72 | ||
73 | #endif | |
74 | ||
75 | void slirp_init(void) | |
76 | { | |
77 | debug_init("/tmp/slirp.log", DEBUG_DEFAULT); | |
78 | ||
79 | link_up = 1; | |
80 | ||
81 | if_init(); | |
82 | ip_init(); | |
83 | ||
84 | /* Initialise mbufs *after* setting the MTU */ | |
85 | m_init(); | |
86 | ||
87 | /* set default addresses */ | |
88 | getouraddr(); | |
89 | inet_aton("127.0.0.1", &loopback_addr); | |
90 | ||
91 | if (get_dns_addr(&dns_addr) < 0) { | |
92 | fprintf(stderr, "Could not get DNS address\n"); | |
93 | exit(1); | |
94 | } | |
95 | ||
96 | inet_aton(CTL_SPECIAL, &special_addr); | |
97 | } | |
98 | ||
99 | #define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED) | |
100 | #define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED) | |
101 | #define UPD_NFDS(x) if (nfds < (x)) nfds = (x) | |
102 | ||
103 | /* | |
104 | * curtime kept to an accuracy of 1ms | |
105 | */ | |
106 | static void updtime(void) | |
107 | { | |
108 | gettimeofday(&tt, 0); | |
109 | ||
110 | curtime = (u_int)tt.tv_sec * (u_int)1000; | |
111 | curtime += (u_int)tt.tv_usec / (u_int)1000; | |
112 | ||
113 | if ((tt.tv_usec % 1000) >= 500) | |
114 | curtime++; | |
115 | } | |
116 | ||
117 | void slirp_select_fill(int *pnfds, | |
118 | fd_set *readfds, fd_set *writefds, fd_set *xfds) | |
119 | { | |
120 | struct socket *so, *so_next; | |
121 | struct timeval timeout; | |
122 | int nfds; | |
123 | int tmp_time; | |
124 | ||
125 | /* fail safe */ | |
126 | global_readfds = NULL; | |
127 | global_writefds = NULL; | |
128 | global_xfds = NULL; | |
129 | ||
130 | nfds = *pnfds; | |
131 | /* | |
132 | * First, TCP sockets | |
133 | */ | |
134 | do_slowtimo = 0; | |
135 | if (link_up) { | |
136 | /* | |
137 | * *_slowtimo needs calling if there are IP fragments | |
138 | * in the fragment queue, or there are TCP connections active | |
139 | */ | |
140 | do_slowtimo = ((tcb.so_next != &tcb) || | |
141 | ((struct ipasfrag *)&ipq != (struct ipasfrag *)ipq.next)); | |
142 | ||
143 | for (so = tcb.so_next; so != &tcb; so = so_next) { | |
144 | so_next = so->so_next; | |
145 | ||
146 | /* | |
147 | * See if we need a tcp_fasttimo | |
148 | */ | |
149 | if (time_fasttimo == 0 && so->so_tcpcb->t_flags & TF_DELACK) | |
150 | time_fasttimo = curtime; /* Flag when we want a fasttimo */ | |
151 | ||
152 | /* | |
153 | * NOFDREF can include still connecting to local-host, | |
154 | * newly socreated() sockets etc. Don't want to select these. | |
155 | */ | |
156 | if (so->so_state & SS_NOFDREF || so->s == -1) | |
157 | continue; | |
158 | ||
159 | /* | |
160 | * Set for reading sockets which are accepting | |
161 | */ | |
162 | if (so->so_state & SS_FACCEPTCONN) { | |
163 | FD_SET(so->s, readfds); | |
164 | UPD_NFDS(so->s); | |
165 | continue; | |
166 | } | |
167 | ||
168 | /* | |
169 | * Set for writing sockets which are connecting | |
170 | */ | |
171 | if (so->so_state & SS_ISFCONNECTING) { | |
172 | FD_SET(so->s, writefds); | |
173 | UPD_NFDS(so->s); | |
174 | continue; | |
175 | } | |
176 | ||
177 | /* | |
178 | * Set for writing if we are connected, can send more, and | |
179 | * we have something to send | |
180 | */ | |
181 | if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) { | |
182 | FD_SET(so->s, writefds); | |
183 | UPD_NFDS(so->s); | |
184 | } | |
185 | ||
186 | /* | |
187 | * Set for reading (and urgent data) if we are connected, can | |
188 | * receive more, and we have room for it XXX /2 ? | |
189 | */ | |
190 | if (CONN_CANFRCV(so) && (so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) { | |
191 | FD_SET(so->s, readfds); | |
192 | FD_SET(so->s, xfds); | |
193 | UPD_NFDS(so->s); | |
194 | } | |
195 | } | |
196 | ||
197 | /* | |
198 | * UDP sockets | |
199 | */ | |
200 | for (so = udb.so_next; so != &udb; so = so_next) { | |
201 | so_next = so->so_next; | |
202 | ||
203 | /* | |
204 | * See if it's timed out | |
205 | */ | |
206 | if (so->so_expire) { | |
207 | if (so->so_expire <= curtime) { | |
208 | udp_detach(so); | |
209 | continue; | |
210 | } else | |
211 | do_slowtimo = 1; /* Let socket expire */ | |
212 | } | |
213 | ||
214 | /* | |
215 | * When UDP packets are received from over the | |
216 | * link, they're sendto()'d straight away, so | |
217 | * no need for setting for writing | |
218 | * Limit the number of packets queued by this session | |
219 | * to 4. Note that even though we try and limit this | |
220 | * to 4 packets, the session could have more queued | |
221 | * if the packets needed to be fragmented | |
222 | * (XXX <= 4 ?) | |
223 | */ | |
224 | if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) { | |
225 | FD_SET(so->s, readfds); | |
226 | UPD_NFDS(so->s); | |
227 | } | |
228 | } | |
229 | } | |
230 | ||
231 | /* | |
232 | * Setup timeout to use minimum CPU usage, especially when idle | |
233 | */ | |
234 | ||
235 | /* | |
236 | * First, see the timeout needed by *timo | |
237 | */ | |
238 | timeout.tv_sec = 0; | |
239 | timeout.tv_usec = -1; | |
240 | /* | |
241 | * If a slowtimo is needed, set timeout to 500ms from the last | |
242 | * slow timeout. If a fast timeout is needed, set timeout within | |
243 | * 200ms of when it was requested. | |
244 | */ | |
245 | if (do_slowtimo) { | |
246 | /* XXX + 10000 because some select()'s aren't that accurate */ | |
247 | timeout.tv_usec = ((500 - (curtime - last_slowtimo)) * 1000) + 10000; | |
248 | if (timeout.tv_usec < 0) | |
249 | timeout.tv_usec = 0; | |
250 | else if (timeout.tv_usec > 510000) | |
251 | timeout.tv_usec = 510000; | |
252 | ||
253 | /* Can only fasttimo if we also slowtimo */ | |
254 | if (time_fasttimo) { | |
255 | tmp_time = (200 - (curtime - time_fasttimo)) * 1000; | |
256 | if (tmp_time < 0) | |
257 | tmp_time = 0; | |
258 | ||
259 | /* Choose the smallest of the 2 */ | |
260 | if (tmp_time < timeout.tv_usec) | |
261 | timeout.tv_usec = (u_int)tmp_time; | |
262 | } | |
263 | } | |
264 | *pnfds = nfds; | |
265 | } | |
266 | ||
267 | void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds) | |
268 | { | |
269 | struct socket *so, *so_next; | |
270 | int ret; | |
271 | ||
272 | global_readfds = readfds; | |
273 | global_writefds = writefds; | |
274 | global_xfds = xfds; | |
275 | ||
276 | /* Update time */ | |
277 | updtime(); | |
278 | ||
279 | /* | |
280 | * See if anything has timed out | |
281 | */ | |
282 | if (link_up) { | |
283 | if (time_fasttimo && ((curtime - time_fasttimo) >= 199)) { | |
284 | tcp_fasttimo(); | |
285 | time_fasttimo = 0; | |
286 | } | |
287 | if (do_slowtimo && ((curtime - last_slowtimo) >= 499)) { | |
288 | ip_slowtimo(); | |
289 | tcp_slowtimo(); | |
290 | last_slowtimo = curtime; | |
291 | } | |
292 | } | |
293 | ||
294 | /* | |
295 | * Check sockets | |
296 | */ | |
297 | if (link_up) { | |
298 | /* | |
299 | * Check TCP sockets | |
300 | */ | |
301 | for (so = tcb.so_next; so != &tcb; so = so_next) { | |
302 | so_next = so->so_next; | |
303 | ||
304 | /* | |
305 | * FD_ISSET is meaningless on these sockets | |
306 | * (and they can crash the program) | |
307 | */ | |
308 | if (so->so_state & SS_NOFDREF || so->s == -1) | |
309 | continue; | |
310 | ||
311 | /* | |
312 | * Check for URG data | |
313 | * This will soread as well, so no need to | |
314 | * test for readfds below if this succeeds | |
315 | */ | |
316 | if (FD_ISSET(so->s, xfds)) | |
317 | sorecvoob(so); | |
318 | /* | |
319 | * Check sockets for reading | |
320 | */ | |
321 | else if (FD_ISSET(so->s, readfds)) { | |
322 | /* | |
323 | * Check for incoming connections | |
324 | */ | |
325 | if (so->so_state & SS_FACCEPTCONN) { | |
326 | tcp_connect(so); | |
327 | continue; | |
328 | } /* else */ | |
329 | ret = soread(so); | |
330 | ||
331 | /* Output it if we read something */ | |
332 | if (ret > 0) | |
333 | tcp_output(sototcpcb(so)); | |
334 | } | |
335 | ||
336 | /* | |
337 | * Check sockets for writing | |
338 | */ | |
339 | if (FD_ISSET(so->s, writefds)) { | |
340 | /* | |
341 | * Check for non-blocking, still-connecting sockets | |
342 | */ | |
343 | if (so->so_state & SS_ISFCONNECTING) { | |
344 | /* Connected */ | |
345 | so->so_state &= ~SS_ISFCONNECTING; | |
346 | ||
347 | ret = write(so->s, &ret, 0); | |
348 | if (ret < 0) { | |
349 | /* XXXXX Must fix, zero bytes is a NOP */ | |
350 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
351 | errno == EINPROGRESS || errno == ENOTCONN) | |
352 | continue; | |
353 | ||
354 | /* else failed */ | |
355 | so->so_state = SS_NOFDREF; | |
356 | } | |
357 | /* else so->so_state &= ~SS_ISFCONNECTING; */ | |
358 | ||
359 | /* | |
360 | * Continue tcp_input | |
361 | */ | |
362 | tcp_input((struct mbuf *)NULL, sizeof(struct ip), so); | |
363 | /* continue; */ | |
364 | } else | |
365 | ret = sowrite(so); | |
366 | /* | |
367 | * XXXXX If we wrote something (a lot), there | |
368 | * could be a need for a window update. | |
369 | * In the worst case, the remote will send | |
370 | * a window probe to get things going again | |
371 | */ | |
372 | } | |
373 | ||
374 | /* | |
375 | * Probe a still-connecting, non-blocking socket | |
376 | * to check if it's still alive | |
377 | */ | |
378 | #ifdef PROBE_CONN | |
379 | if (so->so_state & SS_ISFCONNECTING) { | |
380 | ret = read(so->s, (char *)&ret, 0); | |
381 | ||
382 | if (ret < 0) { | |
383 | /* XXX */ | |
384 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
385 | errno == EINPROGRESS || errno == ENOTCONN) | |
386 | continue; /* Still connecting, continue */ | |
387 | ||
388 | /* else failed */ | |
389 | so->so_state = SS_NOFDREF; | |
390 | ||
391 | /* tcp_input will take care of it */ | |
392 | } else { | |
393 | ret = write(so->s, &ret, 0); | |
394 | if (ret < 0) { | |
395 | /* XXX */ | |
396 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
397 | errno == EINPROGRESS || errno == ENOTCONN) | |
398 | continue; | |
399 | /* else failed */ | |
400 | so->so_state = SS_NOFDREF; | |
401 | } else | |
402 | so->so_state &= ~SS_ISFCONNECTING; | |
403 | ||
404 | } | |
405 | tcp_input((struct mbuf *)NULL, sizeof(struct ip),so); | |
406 | } /* SS_ISFCONNECTING */ | |
407 | #endif | |
408 | } | |
409 | ||
410 | /* | |
411 | * Now UDP sockets. | |
412 | * Incoming packets are sent straight away, they're not buffered. | |
413 | * Incoming UDP data isn't buffered either. | |
414 | */ | |
415 | for (so = udb.so_next; so != &udb; so = so_next) { | |
416 | so_next = so->so_next; | |
417 | ||
418 | if (so->s != -1 && FD_ISSET(so->s, readfds)) { | |
419 | sorecvfrom(so); | |
420 | } | |
421 | } | |
422 | } | |
423 | ||
424 | /* | |
425 | * See if we can start outputting | |
426 | */ | |
427 | if (if_queued && link_up) | |
428 | if_start(); | |
429 | } | |
430 | ||
431 | #define ETH_ALEN 6 | |
432 | #define ETH_HLEN 14 | |
433 | ||
434 | #define ETH_P_IP 0x0800 /* Internet Protocol packet */ | |
435 | #define ETH_P_ARP 0x0806 /* Address Resolution packet */ | |
436 | ||
437 | #define ARPOP_REQUEST 1 /* ARP request */ | |
438 | #define ARPOP_REPLY 2 /* ARP reply */ | |
439 | ||
440 | struct ethhdr | |
441 | { | |
442 | unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ | |
443 | unsigned char h_source[ETH_ALEN]; /* source ether addr */ | |
444 | unsigned short h_proto; /* packet type ID field */ | |
445 | }; | |
446 | ||
447 | struct arphdr | |
448 | { | |
449 | unsigned short ar_hrd; /* format of hardware address */ | |
450 | unsigned short ar_pro; /* format of protocol address */ | |
451 | unsigned char ar_hln; /* length of hardware address */ | |
452 | unsigned char ar_pln; /* length of protocol address */ | |
453 | unsigned short ar_op; /* ARP opcode (command) */ | |
454 | ||
455 | /* | |
456 | * Ethernet looks like this : This bit is variable sized however... | |
457 | */ | |
458 | unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ | |
459 | unsigned char ar_sip[4]; /* sender IP address */ | |
460 | unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ | |
461 | unsigned char ar_tip[4]; /* target IP address */ | |
462 | }; | |
463 | ||
464 | void arp_input(const uint8_t *pkt, int pkt_len) | |
465 | { | |
466 | struct ethhdr *eh = (struct ethhdr *)pkt; | |
467 | struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); | |
468 | uint8_t arp_reply[ETH_HLEN + sizeof(struct arphdr)]; | |
469 | struct ethhdr *reh = (struct ethhdr *)arp_reply; | |
470 | struct arphdr *rah = (struct arphdr *)(arp_reply + ETH_HLEN); | |
471 | int ar_op; | |
472 | ||
473 | ar_op = ntohs(ah->ar_op); | |
474 | switch(ar_op) { | |
475 | case ARPOP_REQUEST: | |
476 | if (!memcmp(ah->ar_tip, &special_addr, 3) && | |
477 | (ah->ar_tip[3] == CTL_DNS || ah->ar_tip[3] == CTL_ALIAS)) { | |
478 | ||
479 | /* XXX: make an ARP request to have the client address */ | |
480 | memcpy(client_ethaddr, eh->h_source, ETH_ALEN); | |
481 | ||
482 | /* ARP request for alias/dns mac address */ | |
483 | memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); | |
484 | memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1); | |
485 | reh->h_source[5] = ah->ar_tip[3]; | |
486 | reh->h_proto = htons(ETH_P_ARP); | |
487 | ||
488 | rah->ar_hrd = htons(1); | |
489 | rah->ar_pro = htons(ETH_P_IP); | |
490 | rah->ar_hln = ETH_ALEN; | |
491 | rah->ar_pln = 4; | |
492 | rah->ar_op = htons(ARPOP_REPLY); | |
493 | memcpy(rah->ar_sha, reh->h_source, ETH_ALEN); | |
494 | memcpy(rah->ar_sip, ah->ar_tip, 4); | |
495 | memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN); | |
496 | memcpy(rah->ar_tip, ah->ar_sip, 4); | |
497 | slirp_output(arp_reply, sizeof(arp_reply)); | |
498 | } | |
499 | break; | |
500 | default: | |
501 | break; | |
502 | } | |
503 | } | |
504 | ||
505 | void slirp_input(const uint8_t *pkt, int pkt_len) | |
506 | { | |
507 | struct mbuf *m; | |
508 | int proto; | |
509 | ||
510 | if (pkt_len < ETH_HLEN) | |
511 | return; | |
512 | ||
513 | proto = ntohs(*(uint16_t *)(pkt + 12)); | |
514 | switch(proto) { | |
515 | case ETH_P_ARP: | |
516 | arp_input(pkt, pkt_len); | |
517 | break; | |
518 | case ETH_P_IP: | |
519 | m = m_get(); | |
520 | if (!m) | |
521 | return; | |
522 | m->m_len = pkt_len; | |
523 | memcpy(m->m_data, pkt, pkt_len); | |
524 | ||
525 | m->m_data += ETH_HLEN; | |
526 | m->m_len -= ETH_HLEN; | |
527 | ||
528 | ip_input(m); | |
529 | break; | |
530 | default: | |
531 | break; | |
532 | } | |
533 | } | |
534 | ||
535 | /* output the IP packet to the ethernet device */ | |
536 | void if_encap(const uint8_t *ip_data, int ip_data_len) | |
537 | { | |
538 | uint8_t buf[1600]; | |
539 | struct ethhdr *eh = (struct ethhdr *)buf; | |
540 | ||
541 | if (ip_data_len + ETH_HLEN > sizeof(buf)) | |
542 | return; | |
543 | ||
544 | memcpy(eh->h_dest, client_ethaddr, ETH_ALEN); | |
545 | memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 1); | |
546 | eh->h_source[5] = CTL_ALIAS; | |
547 | eh->h_proto = htons(ETH_P_IP); | |
548 | memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len); | |
549 | slirp_output(buf, ip_data_len + ETH_HLEN); | |
550 | } |