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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 | } | |
1d43a717 | 68 | fclose(f); |
f0cbd3ec FB |
69 | if (!found) |
70 | return -1; | |
71 | return 0; | |
72 | } | |
73 | ||
74 | #endif | |
75 | ||
76 | void slirp_init(void) | |
77 | { | |
512176db | 78 | // debug_init("/tmp/slirp.log", DEBUG_DEFAULT); |
1d43a717 | 79 | |
f0cbd3ec FB |
80 | link_up = 1; |
81 | ||
82 | if_init(); | |
83 | ip_init(); | |
84 | ||
85 | /* Initialise mbufs *after* setting the MTU */ | |
86 | m_init(); | |
87 | ||
88 | /* set default addresses */ | |
89 | getouraddr(); | |
90 | inet_aton("127.0.0.1", &loopback_addr); | |
91 | ||
92 | if (get_dns_addr(&dns_addr) < 0) { | |
93 | fprintf(stderr, "Could not get DNS address\n"); | |
94 | exit(1); | |
95 | } | |
96 | ||
97 | inet_aton(CTL_SPECIAL, &special_addr); | |
98 | } | |
99 | ||
100 | #define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED) | |
101 | #define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED) | |
102 | #define UPD_NFDS(x) if (nfds < (x)) nfds = (x) | |
103 | ||
104 | /* | |
105 | * curtime kept to an accuracy of 1ms | |
106 | */ | |
107 | static void updtime(void) | |
108 | { | |
109 | gettimeofday(&tt, 0); | |
110 | ||
111 | curtime = (u_int)tt.tv_sec * (u_int)1000; | |
112 | curtime += (u_int)tt.tv_usec / (u_int)1000; | |
113 | ||
114 | if ((tt.tv_usec % 1000) >= 500) | |
115 | curtime++; | |
116 | } | |
117 | ||
118 | void slirp_select_fill(int *pnfds, | |
119 | fd_set *readfds, fd_set *writefds, fd_set *xfds) | |
120 | { | |
121 | struct socket *so, *so_next; | |
122 | struct timeval timeout; | |
123 | int nfds; | |
124 | int tmp_time; | |
125 | ||
126 | /* fail safe */ | |
127 | global_readfds = NULL; | |
128 | global_writefds = NULL; | |
129 | global_xfds = NULL; | |
130 | ||
131 | nfds = *pnfds; | |
132 | /* | |
133 | * First, TCP sockets | |
134 | */ | |
135 | do_slowtimo = 0; | |
136 | if (link_up) { | |
137 | /* | |
138 | * *_slowtimo needs calling if there are IP fragments | |
139 | * in the fragment queue, or there are TCP connections active | |
140 | */ | |
141 | do_slowtimo = ((tcb.so_next != &tcb) || | |
142 | ((struct ipasfrag *)&ipq != (struct ipasfrag *)ipq.next)); | |
143 | ||
144 | for (so = tcb.so_next; so != &tcb; so = so_next) { | |
145 | so_next = so->so_next; | |
146 | ||
147 | /* | |
148 | * See if we need a tcp_fasttimo | |
149 | */ | |
150 | if (time_fasttimo == 0 && so->so_tcpcb->t_flags & TF_DELACK) | |
151 | time_fasttimo = curtime; /* Flag when we want a fasttimo */ | |
152 | ||
153 | /* | |
154 | * NOFDREF can include still connecting to local-host, | |
155 | * newly socreated() sockets etc. Don't want to select these. | |
156 | */ | |
157 | if (so->so_state & SS_NOFDREF || so->s == -1) | |
158 | continue; | |
159 | ||
160 | /* | |
161 | * Set for reading sockets which are accepting | |
162 | */ | |
163 | if (so->so_state & SS_FACCEPTCONN) { | |
164 | FD_SET(so->s, readfds); | |
165 | UPD_NFDS(so->s); | |
166 | continue; | |
167 | } | |
168 | ||
169 | /* | |
170 | * Set for writing sockets which are connecting | |
171 | */ | |
172 | if (so->so_state & SS_ISFCONNECTING) { | |
173 | FD_SET(so->s, writefds); | |
174 | UPD_NFDS(so->s); | |
175 | continue; | |
176 | } | |
177 | ||
178 | /* | |
179 | * Set for writing if we are connected, can send more, and | |
180 | * we have something to send | |
181 | */ | |
182 | if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) { | |
183 | FD_SET(so->s, writefds); | |
184 | UPD_NFDS(so->s); | |
185 | } | |
186 | ||
187 | /* | |
188 | * Set for reading (and urgent data) if we are connected, can | |
189 | * receive more, and we have room for it XXX /2 ? | |
190 | */ | |
191 | if (CONN_CANFRCV(so) && (so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) { | |
192 | FD_SET(so->s, readfds); | |
193 | FD_SET(so->s, xfds); | |
194 | UPD_NFDS(so->s); | |
195 | } | |
196 | } | |
197 | ||
198 | /* | |
199 | * UDP sockets | |
200 | */ | |
201 | for (so = udb.so_next; so != &udb; so = so_next) { | |
202 | so_next = so->so_next; | |
203 | ||
204 | /* | |
205 | * See if it's timed out | |
206 | */ | |
207 | if (so->so_expire) { | |
208 | if (so->so_expire <= curtime) { | |
209 | udp_detach(so); | |
210 | continue; | |
211 | } else | |
212 | do_slowtimo = 1; /* Let socket expire */ | |
213 | } | |
214 | ||
215 | /* | |
216 | * When UDP packets are received from over the | |
217 | * link, they're sendto()'d straight away, so | |
218 | * no need for setting for writing | |
219 | * Limit the number of packets queued by this session | |
220 | * to 4. Note that even though we try and limit this | |
221 | * to 4 packets, the session could have more queued | |
222 | * if the packets needed to be fragmented | |
223 | * (XXX <= 4 ?) | |
224 | */ | |
225 | if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) { | |
226 | FD_SET(so->s, readfds); | |
227 | UPD_NFDS(so->s); | |
228 | } | |
229 | } | |
230 | } | |
231 | ||
232 | /* | |
233 | * Setup timeout to use minimum CPU usage, especially when idle | |
234 | */ | |
235 | ||
236 | /* | |
237 | * First, see the timeout needed by *timo | |
238 | */ | |
239 | timeout.tv_sec = 0; | |
240 | timeout.tv_usec = -1; | |
241 | /* | |
242 | * If a slowtimo is needed, set timeout to 500ms from the last | |
243 | * slow timeout. If a fast timeout is needed, set timeout within | |
244 | * 200ms of when it was requested. | |
245 | */ | |
246 | if (do_slowtimo) { | |
247 | /* XXX + 10000 because some select()'s aren't that accurate */ | |
248 | timeout.tv_usec = ((500 - (curtime - last_slowtimo)) * 1000) + 10000; | |
249 | if (timeout.tv_usec < 0) | |
250 | timeout.tv_usec = 0; | |
251 | else if (timeout.tv_usec > 510000) | |
252 | timeout.tv_usec = 510000; | |
253 | ||
254 | /* Can only fasttimo if we also slowtimo */ | |
255 | if (time_fasttimo) { | |
256 | tmp_time = (200 - (curtime - time_fasttimo)) * 1000; | |
257 | if (tmp_time < 0) | |
258 | tmp_time = 0; | |
259 | ||
260 | /* Choose the smallest of the 2 */ | |
261 | if (tmp_time < timeout.tv_usec) | |
262 | timeout.tv_usec = (u_int)tmp_time; | |
263 | } | |
264 | } | |
265 | *pnfds = nfds; | |
266 | } | |
267 | ||
268 | void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds) | |
269 | { | |
270 | struct socket *so, *so_next; | |
271 | int ret; | |
272 | ||
273 | global_readfds = readfds; | |
274 | global_writefds = writefds; | |
275 | global_xfds = xfds; | |
276 | ||
277 | /* Update time */ | |
278 | updtime(); | |
279 | ||
280 | /* | |
281 | * See if anything has timed out | |
282 | */ | |
283 | if (link_up) { | |
284 | if (time_fasttimo && ((curtime - time_fasttimo) >= 199)) { | |
285 | tcp_fasttimo(); | |
286 | time_fasttimo = 0; | |
287 | } | |
288 | if (do_slowtimo && ((curtime - last_slowtimo) >= 499)) { | |
289 | ip_slowtimo(); | |
290 | tcp_slowtimo(); | |
291 | last_slowtimo = curtime; | |
292 | } | |
293 | } | |
294 | ||
295 | /* | |
296 | * Check sockets | |
297 | */ | |
298 | if (link_up) { | |
299 | /* | |
300 | * Check TCP sockets | |
301 | */ | |
302 | for (so = tcb.so_next; so != &tcb; so = so_next) { | |
303 | so_next = so->so_next; | |
304 | ||
305 | /* | |
306 | * FD_ISSET is meaningless on these sockets | |
307 | * (and they can crash the program) | |
308 | */ | |
309 | if (so->so_state & SS_NOFDREF || so->s == -1) | |
310 | continue; | |
311 | ||
312 | /* | |
313 | * Check for URG data | |
314 | * This will soread as well, so no need to | |
315 | * test for readfds below if this succeeds | |
316 | */ | |
317 | if (FD_ISSET(so->s, xfds)) | |
318 | sorecvoob(so); | |
319 | /* | |
320 | * Check sockets for reading | |
321 | */ | |
322 | else if (FD_ISSET(so->s, readfds)) { | |
323 | /* | |
324 | * Check for incoming connections | |
325 | */ | |
326 | if (so->so_state & SS_FACCEPTCONN) { | |
327 | tcp_connect(so); | |
328 | continue; | |
329 | } /* else */ | |
330 | ret = soread(so); | |
331 | ||
332 | /* Output it if we read something */ | |
333 | if (ret > 0) | |
334 | tcp_output(sototcpcb(so)); | |
335 | } | |
336 | ||
337 | /* | |
338 | * Check sockets for writing | |
339 | */ | |
340 | if (FD_ISSET(so->s, writefds)) { | |
341 | /* | |
342 | * Check for non-blocking, still-connecting sockets | |
343 | */ | |
344 | if (so->so_state & SS_ISFCONNECTING) { | |
345 | /* Connected */ | |
346 | so->so_state &= ~SS_ISFCONNECTING; | |
347 | ||
348 | ret = write(so->s, &ret, 0); | |
349 | if (ret < 0) { | |
350 | /* XXXXX Must fix, zero bytes is a NOP */ | |
351 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
352 | errno == EINPROGRESS || errno == ENOTCONN) | |
353 | continue; | |
354 | ||
355 | /* else failed */ | |
356 | so->so_state = SS_NOFDREF; | |
357 | } | |
358 | /* else so->so_state &= ~SS_ISFCONNECTING; */ | |
359 | ||
360 | /* | |
361 | * Continue tcp_input | |
362 | */ | |
363 | tcp_input((struct mbuf *)NULL, sizeof(struct ip), so); | |
364 | /* continue; */ | |
365 | } else | |
366 | ret = sowrite(so); | |
367 | /* | |
368 | * XXXXX If we wrote something (a lot), there | |
369 | * could be a need for a window update. | |
370 | * In the worst case, the remote will send | |
371 | * a window probe to get things going again | |
372 | */ | |
373 | } | |
374 | ||
375 | /* | |
376 | * Probe a still-connecting, non-blocking socket | |
377 | * to check if it's still alive | |
378 | */ | |
379 | #ifdef PROBE_CONN | |
380 | if (so->so_state & SS_ISFCONNECTING) { | |
381 | ret = read(so->s, (char *)&ret, 0); | |
382 | ||
383 | if (ret < 0) { | |
384 | /* XXX */ | |
385 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
386 | errno == EINPROGRESS || errno == ENOTCONN) | |
387 | continue; /* Still connecting, continue */ | |
388 | ||
389 | /* else failed */ | |
390 | so->so_state = SS_NOFDREF; | |
391 | ||
392 | /* tcp_input will take care of it */ | |
393 | } else { | |
394 | ret = write(so->s, &ret, 0); | |
395 | if (ret < 0) { | |
396 | /* XXX */ | |
397 | if (errno == EAGAIN || errno == EWOULDBLOCK || | |
398 | errno == EINPROGRESS || errno == ENOTCONN) | |
399 | continue; | |
400 | /* else failed */ | |
401 | so->so_state = SS_NOFDREF; | |
402 | } else | |
403 | so->so_state &= ~SS_ISFCONNECTING; | |
404 | ||
405 | } | |
406 | tcp_input((struct mbuf *)NULL, sizeof(struct ip),so); | |
407 | } /* SS_ISFCONNECTING */ | |
408 | #endif | |
409 | } | |
410 | ||
411 | /* | |
412 | * Now UDP sockets. | |
413 | * Incoming packets are sent straight away, they're not buffered. | |
414 | * Incoming UDP data isn't buffered either. | |
415 | */ | |
416 | for (so = udb.so_next; so != &udb; so = so_next) { | |
417 | so_next = so->so_next; | |
418 | ||
419 | if (so->s != -1 && FD_ISSET(so->s, readfds)) { | |
420 | sorecvfrom(so); | |
421 | } | |
422 | } | |
423 | } | |
424 | ||
425 | /* | |
426 | * See if we can start outputting | |
427 | */ | |
428 | if (if_queued && link_up) | |
429 | if_start(); | |
430 | } | |
431 | ||
432 | #define ETH_ALEN 6 | |
433 | #define ETH_HLEN 14 | |
434 | ||
435 | #define ETH_P_IP 0x0800 /* Internet Protocol packet */ | |
436 | #define ETH_P_ARP 0x0806 /* Address Resolution packet */ | |
437 | ||
438 | #define ARPOP_REQUEST 1 /* ARP request */ | |
439 | #define ARPOP_REPLY 2 /* ARP reply */ | |
440 | ||
441 | struct ethhdr | |
442 | { | |
443 | unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ | |
444 | unsigned char h_source[ETH_ALEN]; /* source ether addr */ | |
445 | unsigned short h_proto; /* packet type ID field */ | |
446 | }; | |
447 | ||
448 | struct arphdr | |
449 | { | |
450 | unsigned short ar_hrd; /* format of hardware address */ | |
451 | unsigned short ar_pro; /* format of protocol address */ | |
452 | unsigned char ar_hln; /* length of hardware address */ | |
453 | unsigned char ar_pln; /* length of protocol address */ | |
454 | unsigned short ar_op; /* ARP opcode (command) */ | |
455 | ||
456 | /* | |
457 | * Ethernet looks like this : This bit is variable sized however... | |
458 | */ | |
459 | unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ | |
460 | unsigned char ar_sip[4]; /* sender IP address */ | |
461 | unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ | |
462 | unsigned char ar_tip[4]; /* target IP address */ | |
463 | }; | |
464 | ||
465 | void arp_input(const uint8_t *pkt, int pkt_len) | |
466 | { | |
467 | struct ethhdr *eh = (struct ethhdr *)pkt; | |
468 | struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); | |
469 | uint8_t arp_reply[ETH_HLEN + sizeof(struct arphdr)]; | |
470 | struct ethhdr *reh = (struct ethhdr *)arp_reply; | |
471 | struct arphdr *rah = (struct arphdr *)(arp_reply + ETH_HLEN); | |
472 | int ar_op; | |
473 | ||
474 | ar_op = ntohs(ah->ar_op); | |
475 | switch(ar_op) { | |
476 | case ARPOP_REQUEST: | |
477 | if (!memcmp(ah->ar_tip, &special_addr, 3) && | |
478 | (ah->ar_tip[3] == CTL_DNS || ah->ar_tip[3] == CTL_ALIAS)) { | |
479 | ||
480 | /* XXX: make an ARP request to have the client address */ | |
481 | memcpy(client_ethaddr, eh->h_source, ETH_ALEN); | |
482 | ||
483 | /* ARP request for alias/dns mac address */ | |
484 | memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); | |
485 | memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1); | |
486 | reh->h_source[5] = ah->ar_tip[3]; | |
487 | reh->h_proto = htons(ETH_P_ARP); | |
488 | ||
489 | rah->ar_hrd = htons(1); | |
490 | rah->ar_pro = htons(ETH_P_IP); | |
491 | rah->ar_hln = ETH_ALEN; | |
492 | rah->ar_pln = 4; | |
493 | rah->ar_op = htons(ARPOP_REPLY); | |
494 | memcpy(rah->ar_sha, reh->h_source, ETH_ALEN); | |
495 | memcpy(rah->ar_sip, ah->ar_tip, 4); | |
496 | memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN); | |
497 | memcpy(rah->ar_tip, ah->ar_sip, 4); | |
498 | slirp_output(arp_reply, sizeof(arp_reply)); | |
499 | } | |
500 | break; | |
501 | default: | |
502 | break; | |
503 | } | |
504 | } | |
505 | ||
506 | void slirp_input(const uint8_t *pkt, int pkt_len) | |
507 | { | |
508 | struct mbuf *m; | |
509 | int proto; | |
510 | ||
511 | if (pkt_len < ETH_HLEN) | |
512 | return; | |
513 | ||
514 | proto = ntohs(*(uint16_t *)(pkt + 12)); | |
515 | switch(proto) { | |
516 | case ETH_P_ARP: | |
517 | arp_input(pkt, pkt_len); | |
518 | break; | |
519 | case ETH_P_IP: | |
520 | m = m_get(); | |
521 | if (!m) | |
522 | return; | |
523 | m->m_len = pkt_len; | |
524 | memcpy(m->m_data, pkt, pkt_len); | |
525 | ||
526 | m->m_data += ETH_HLEN; | |
527 | m->m_len -= ETH_HLEN; | |
528 | ||
529 | ip_input(m); | |
530 | break; | |
531 | default: | |
532 | break; | |
533 | } | |
534 | } | |
535 | ||
536 | /* output the IP packet to the ethernet device */ | |
537 | void if_encap(const uint8_t *ip_data, int ip_data_len) | |
538 | { | |
539 | uint8_t buf[1600]; | |
540 | struct ethhdr *eh = (struct ethhdr *)buf; | |
541 | ||
542 | if (ip_data_len + ETH_HLEN > sizeof(buf)) | |
543 | return; | |
544 | ||
545 | memcpy(eh->h_dest, client_ethaddr, ETH_ALEN); | |
546 | memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 1); | |
547 | eh->h_source[5] = CTL_ALIAS; | |
548 | eh->h_proto = htons(ETH_P_IP); | |
549 | memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len); | |
550 | slirp_output(buf, ip_data_len + ETH_HLEN); | |
551 | } |