bootp.c 12 KB

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  1. #include "u.h"
  2. #include "lib.h"
  3. #include "mem.h"
  4. #include "dat.h"
  5. #include "fns.h"
  6. #include "io.h"
  7. #include "ip.h"
  8. uchar broadcast[Eaddrlen] = {
  9. 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  10. };
  11. static ushort tftpport = 5000;
  12. static int Id = 1;
  13. static Netaddr myaddr;
  14. static Netaddr server;
  15. typedef struct {
  16. uchar header[4];
  17. uchar data[Segsize];
  18. } Tftp;
  19. static Tftp tftpb;
  20. static void
  21. hnputs(uchar *ptr, ushort val)
  22. {
  23. ptr[0] = val>>8;
  24. ptr[1] = val;
  25. }
  26. static void
  27. hnputl(uchar *ptr, ulong val)
  28. {
  29. ptr[0] = val>>24;
  30. ptr[1] = val>>16;
  31. ptr[2] = val>>8;
  32. ptr[3] = val;
  33. }
  34. static ulong
  35. nhgetl(uchar *ptr)
  36. {
  37. return ((ptr[0]<<24) | (ptr[1]<<16) | (ptr[2]<<8) | ptr[3]);
  38. }
  39. static ushort
  40. nhgets(uchar *ptr)
  41. {
  42. return ((ptr[0]<<8) | ptr[1]);
  43. }
  44. static short endian = 1;
  45. static char* aendian = (char*)&endian;
  46. #define LITTLE *aendian
  47. static ushort
  48. ptcl_csum(void *a, int len)
  49. {
  50. uchar *addr;
  51. ulong t1, t2;
  52. ulong losum, hisum, mdsum, x;
  53. addr = a;
  54. losum = 0;
  55. hisum = 0;
  56. mdsum = 0;
  57. x = 0;
  58. if((ulong)addr & 1) {
  59. if(len) {
  60. hisum += addr[0];
  61. len--;
  62. addr++;
  63. }
  64. x = 1;
  65. }
  66. while(len >= 16) {
  67. t1 = *(ushort*)(addr+0);
  68. t2 = *(ushort*)(addr+2); mdsum += t1;
  69. t1 = *(ushort*)(addr+4); mdsum += t2;
  70. t2 = *(ushort*)(addr+6); mdsum += t1;
  71. t1 = *(ushort*)(addr+8); mdsum += t2;
  72. t2 = *(ushort*)(addr+10); mdsum += t1;
  73. t1 = *(ushort*)(addr+12); mdsum += t2;
  74. t2 = *(ushort*)(addr+14); mdsum += t1;
  75. mdsum += t2;
  76. len -= 16;
  77. addr += 16;
  78. }
  79. while(len >= 2) {
  80. mdsum += *(ushort*)addr;
  81. len -= 2;
  82. addr += 2;
  83. }
  84. if(x) {
  85. if(len)
  86. losum += addr[0];
  87. if(LITTLE)
  88. losum += mdsum;
  89. else
  90. hisum += mdsum;
  91. } else {
  92. if(len)
  93. hisum += addr[0];
  94. if(LITTLE)
  95. hisum += mdsum;
  96. else
  97. losum += mdsum;
  98. }
  99. losum += hisum >> 8;
  100. losum += (hisum & 0xff) << 8;
  101. while(hisum = losum>>16)
  102. losum = hisum + (losum & 0xffff);
  103. return ~losum;
  104. }
  105. static ushort
  106. ip_csum(uchar *addr)
  107. {
  108. int len;
  109. ulong sum = 0;
  110. len = (addr[0]&0xf)<<2;
  111. while(len > 0) {
  112. sum += addr[0]<<8 | addr[1] ;
  113. len -= 2;
  114. addr += 2;
  115. }
  116. sum = (sum & 0xffff) + (sum >> 16);
  117. sum = (sum & 0xffff) + (sum >> 16);
  118. return (sum^0xffff);
  119. }
  120. enum {
  121. /* this is only true of IPv4, but we're not doing v6 yet */
  122. Min_udp_payload = ETHERMINTU - ETHERHDRSIZE - UDP_HDRSIZE,
  123. };
  124. static void
  125. udpsend(int ctlrno, Netaddr *a, void *data, int dlen)
  126. {
  127. char payload[ETHERMAXTU];
  128. Udphdr *uh;
  129. Etherhdr *ip;
  130. Etherpkt pkt;
  131. int len, ptcllen;
  132. /*
  133. * if packet is too short, make it longer rather than relying
  134. * on ethernet interface or lower layers to pad it.
  135. */
  136. if (dlen < Min_udp_payload) {
  137. memmove(payload, data, dlen);
  138. data = payload;
  139. dlen = Min_udp_payload;
  140. }
  141. uh = (Udphdr*)&pkt;
  142. memset(uh, 0, sizeof(Etherpkt));
  143. memmove(uh->udpcksum+sizeof(uh->udpcksum), data, dlen);
  144. /*
  145. * UDP portion
  146. */
  147. ptcllen = dlen + (UDP_HDRSIZE-UDP_PHDRSIZE);
  148. uh->ttl = 0;
  149. uh->udpproto = IP_UDPPROTO;
  150. uh->frag[0] = 0;
  151. uh->frag[1] = 0;
  152. hnputs(uh->udpplen, ptcllen);
  153. hnputl(uh->udpsrc, myaddr.ip);
  154. hnputs(uh->udpsport, myaddr.port);
  155. hnputl(uh->udpdst, a->ip);
  156. hnputs(uh->udpdport, a->port);
  157. hnputs(uh->udplen, ptcllen);
  158. uh->udpcksum[0] = 0;
  159. uh->udpcksum[1] = 0;
  160. dlen = (dlen+1)&~1;
  161. hnputs(uh->udpcksum, ptcl_csum(&uh->ttl, dlen+UDP_HDRSIZE));
  162. /*
  163. * IP portion
  164. */
  165. ip = (Etherhdr*)&pkt;
  166. len = UDP_EHSIZE+UDP_HDRSIZE+dlen; /* non-descriptive names */
  167. ip->vihl = IP_VER|IP_HLEN;
  168. ip->tos = 0;
  169. ip->ttl = 255;
  170. hnputs(ip->length, len-ETHER_HDR);
  171. hnputs(ip->id, Id++);
  172. ip->frag[0] = 0;
  173. ip->frag[1] = 0;
  174. ip->cksum[0] = 0;
  175. ip->cksum[1] = 0;
  176. hnputs(ip->cksum, ip_csum(&ip->vihl));
  177. /*
  178. * Ethernet MAC portion
  179. */
  180. hnputs(ip->type, ET_IP);
  181. memmove(ip->d, a->ea, sizeof(ip->d));
  182. if(debug) {
  183. print("udpsend ");
  184. }
  185. ethertxpkt(ctlrno, &pkt, len, Timeout);
  186. }
  187. static void
  188. nak(int ctlrno, Netaddr *a, int code, char *msg, int report)
  189. {
  190. int n;
  191. char buf[128];
  192. buf[0] = 0;
  193. buf[1] = Tftp_ERROR;
  194. buf[2] = 0;
  195. buf[3] = code;
  196. strcpy(buf+4, msg);
  197. n = strlen(msg) + 4 + 1;
  198. udpsend(ctlrno, a, buf, n);
  199. if(report)
  200. print("\ntftp: error(%d): %s\n", code, msg);
  201. }
  202. static int
  203. udprecv(int ctlrno, Netaddr *a, void *data, int dlen)
  204. {
  205. int n, len;
  206. ushort csm;
  207. Udphdr *h;
  208. ulong addr, timo;
  209. Etherpkt pkt;
  210. static int rxactive;
  211. if(rxactive == 0)
  212. timo = 1000;
  213. else
  214. timo = Timeout;
  215. timo += TK2MS(m->ticks);
  216. while(timo > TK2MS(m->ticks)){
  217. n = etherrxpkt(ctlrno, &pkt, timo-TK2MS(m->ticks));
  218. if(n <= 0)
  219. continue;
  220. h = (Udphdr*)&pkt;
  221. if(debug)
  222. print("udprecv %E to %E...\n", h->s, h->d);
  223. if(nhgets(h->type) != ET_IP) {
  224. if(debug)
  225. print("not ip...");
  226. continue;
  227. }
  228. if(ip_csum(&h->vihl)) {
  229. print("ip chksum error\n");
  230. continue;
  231. }
  232. if(h->vihl != (IP_VER|IP_HLEN)) {
  233. print("ip bad vers/hlen\n");
  234. continue;
  235. }
  236. if(h->udpproto != IP_UDPPROTO) {
  237. if(debug)
  238. print("not udp (%d)...", h->udpproto);
  239. continue;
  240. }
  241. if(debug)
  242. print("okay udp...");
  243. h->ttl = 0;
  244. len = nhgets(h->udplen);
  245. hnputs(h->udpplen, len);
  246. if(nhgets(h->udpcksum)) {
  247. csm = ptcl_csum(&h->ttl, len+UDP_PHDRSIZE);
  248. if(csm != 0) {
  249. print("udp chksum error csum #%4ux len %d\n",
  250. csm, n);
  251. break;
  252. }
  253. }
  254. if(a->port != 0 && nhgets(h->udpsport) != a->port) {
  255. if(debug)
  256. print("udpport %ux %ux\n",
  257. nhgets(h->udpsport), a->port);
  258. continue;
  259. }
  260. addr = nhgetl(h->udpsrc);
  261. if(a->ip != Bcastip && addr != a->ip) {
  262. if(debug)
  263. print("bad ip\n");
  264. continue;
  265. }
  266. len -= UDP_HDRSIZE-UDP_PHDRSIZE;
  267. if(len > dlen) {
  268. print("udp: packet too big: %d > %d; from addr %E\n",
  269. len, dlen, h->udpsrc);
  270. continue;
  271. }
  272. memmove(data, h->udpcksum+sizeof(h->udpcksum), len);
  273. a->ip = addr;
  274. a->port = nhgets(h->udpsport);
  275. memmove(a->ea, pkt.s, sizeof(a->ea));
  276. rxactive = 1;
  277. return len;
  278. }
  279. return 0;
  280. }
  281. static int tftpblockno;
  282. /*
  283. * format of a request packet, from the RFC:
  284. *
  285. 2 bytes string 1 byte string 1 byte
  286. ------------------------------------------------
  287. | Opcode | Filename | 0 | Mode | 0 |
  288. ------------------------------------------------
  289. */
  290. static int
  291. tftpopen(int ctlrno, Netaddr *a, char *name, Tftp *tftp)
  292. {
  293. int i, len, rlen, oport;
  294. char buf[Segsize+2];
  295. buf[0] = 0;
  296. buf[1] = Tftp_READ;
  297. len = 2 + sprint(buf+2, "%s", name) + 1;
  298. len += sprint(buf+len, "octet") + 1;
  299. oport = a->port;
  300. for(i = 0; i < 5; i++){
  301. a->port = oport;
  302. udpsend(ctlrno, a, buf, len);
  303. a->port = 0;
  304. if((rlen = udprecv(ctlrno, a, tftp, sizeof(Tftp))) < sizeof(tftp->header))
  305. continue;
  306. switch((tftp->header[0]<<8)|tftp->header[1]){
  307. case Tftp_ERROR:
  308. print("tftpopen: error (%d): %s\n",
  309. (tftp->header[2]<<8)|tftp->header[3], (char*)tftp->data);
  310. return -1;
  311. case Tftp_DATA:
  312. tftpblockno = 1;
  313. len = (tftp->header[2]<<8)|tftp->header[3];
  314. if(len != tftpblockno){
  315. print("tftpopen: block error: %d\n", len);
  316. nak(ctlrno, a, 1, "block error", 0);
  317. return -1;
  318. }
  319. rlen -= sizeof(tftp->header);
  320. if(rlen < Segsize){
  321. /* ACK now, in case we don't later */
  322. buf[0] = 0;
  323. buf[1] = Tftp_ACK;
  324. buf[2] = tftpblockno>>8;
  325. buf[3] = tftpblockno;
  326. udpsend(ctlrno, a, buf, sizeof(tftp->header));
  327. }
  328. return rlen;
  329. }
  330. }
  331. print("tftpopen: failed to connect to server\n");
  332. return -1;
  333. }
  334. static int
  335. tftpread(int ctlrno, Netaddr *a, Tftp *tftp, int dlen)
  336. {
  337. uchar buf[4];
  338. int try, blockno, len;
  339. dlen += sizeof(tftp->header);
  340. for(try = 0; try < 10; try++) {
  341. buf[0] = 0;
  342. buf[1] = Tftp_ACK;
  343. buf[2] = tftpblockno>>8;
  344. buf[3] = tftpblockno;
  345. udpsend(ctlrno, a, buf, sizeof(buf));
  346. len = udprecv(ctlrno, a, tftp, dlen);
  347. if(len <= sizeof(tftp->header)){
  348. if(debug)
  349. print("tftpread: too short %d <= %d\n",
  350. len, sizeof(tftp->header));
  351. continue;
  352. }
  353. blockno = (tftp->header[2]<<8)|tftp->header[3];
  354. if(blockno <= tftpblockno){
  355. if(debug)
  356. print("tftpread: blkno %d <= %d\n",
  357. blockno, tftpblockno);
  358. continue;
  359. }
  360. if(blockno == tftpblockno+1) {
  361. tftpblockno++;
  362. if(len < dlen) { /* last packet; send final ack */
  363. tftpblockno++;
  364. buf[0] = 0;
  365. buf[1] = Tftp_ACK;
  366. buf[2] = tftpblockno>>8;
  367. buf[3] = tftpblockno;
  368. udpsend(ctlrno, a, buf, sizeof(buf));
  369. }
  370. return len-sizeof(tftp->header);
  371. }
  372. print("tftpread: block error: %d, expected %d\n",
  373. blockno, tftpblockno+1);
  374. }
  375. return -1;
  376. }
  377. static int
  378. bootpopen(int ctlrno, char *file, Bootp *rep, int dotftpopen)
  379. {
  380. Bootp req;
  381. int i, n;
  382. uchar *ea;
  383. char name[128], *filename, *sysname;
  384. if((ea = etheraddr(ctlrno)) == 0){
  385. print("invalid ctlrno %d\n", ctlrno);
  386. return -1;
  387. }
  388. filename = 0;
  389. sysname = 0;
  390. if(file && *file){
  391. strcpy(name, file);
  392. if(filename = strchr(name, '!')){
  393. sysname = name;
  394. *filename++ = 0;
  395. }
  396. else
  397. filename = name;
  398. }
  399. memset(&req, 0, sizeof(req));
  400. req.op = Bootrequest;
  401. req.htype = 1; /* ethernet */
  402. req.hlen = Eaddrlen; /* ethernet */
  403. memmove(req.chaddr, ea, Eaddrlen);
  404. if(filename != nil)
  405. strncpy(req.file, filename, sizeof(req.file));
  406. if(sysname != nil)
  407. strncpy(req.sname, sysname, sizeof(req.sname));
  408. myaddr.ip = 0;
  409. myaddr.port = BPportsrc;
  410. memmove(myaddr.ea, ea, Eaddrlen);
  411. etherrxflush(ctlrno);
  412. for(i = 0; i < 10; i++) {
  413. server.ip = Bcastip;
  414. server.port = BPportdst;
  415. memmove(server.ea, broadcast, sizeof(server.ea));
  416. udpsend(ctlrno, &server, &req, sizeof(req));
  417. if(udprecv(ctlrno, &server, rep, sizeof(*rep)) <= 0)
  418. continue;
  419. if(memcmp(req.chaddr, rep->chaddr, Eaddrlen))
  420. continue;
  421. if(rep->htype != 1 || rep->hlen != Eaddrlen)
  422. continue;
  423. if(sysname == 0 || strcmp(sysname, rep->sname) == 0)
  424. break;
  425. }
  426. if(i >= 10) {
  427. print("bootp timed out\n");
  428. return -1;
  429. }
  430. if(!dotftpopen)
  431. return 0;
  432. if(filename == 0 || *filename == 0){
  433. if(strcmp(rep->file, "/386/9pxeload") == 0)
  434. return -1;
  435. filename = rep->file;
  436. }
  437. if(rep->sname[0] != '\0')
  438. print("%s ", rep->sname);
  439. print("(%d.%d.%d.%d!%d): %s\n",
  440. rep->siaddr[0],
  441. rep->siaddr[1],
  442. rep->siaddr[2],
  443. rep->siaddr[3],
  444. server.port,
  445. filename);
  446. myaddr.ip = nhgetl(rep->yiaddr);
  447. myaddr.port = tftpport++;
  448. server.ip = nhgetl(rep->siaddr);
  449. server.port = TFTPport;
  450. if((n = tftpopen(ctlrno, &server, filename, &tftpb)) < 0)
  451. return -1;
  452. return n;
  453. }
  454. int
  455. bootpboot(int ctlrno, char *file, Boot *b)
  456. {
  457. int n;
  458. Bootp rep;
  459. if((n = bootpopen(ctlrno, file, &rep, 1)) < 0)
  460. return -1;
  461. while(bootpass(b, tftpb.data, n) == MORE){
  462. n = tftpread(ctlrno, &server, &tftpb, sizeof(tftpb.data));
  463. if(n < sizeof(tftpb.data))
  464. break;
  465. }
  466. if(0 < n && n < sizeof(tftpb.data)) /* got to end of file */
  467. bootpass(b, tftpb.data, n);
  468. else
  469. nak(ctlrno, &server, 3, "ok", 0); /* tftpclose to abort transfer */
  470. bootpass(b, nil, 0); /* boot if possible */
  471. return -1;
  472. }
  473. #include "fs.h"
  474. #define INIPATHLEN 64
  475. static struct {
  476. Fs fs;
  477. char ini[INIPATHLEN];
  478. } pxether[MaxEther];
  479. static vlong
  480. pxediskseek(Fs*, vlong)
  481. {
  482. return -1LL;
  483. }
  484. static long
  485. pxediskread(Fs*, void*, long)
  486. {
  487. return -1;
  488. }
  489. static long
  490. pxeread(File* f, void* va, long len)
  491. {
  492. int n;
  493. Bootp rep;
  494. char *p, *v;
  495. if((n = bootpopen(f->fs->dev, pxether[f->fs->dev].ini, &rep, 1)) < 0)
  496. return -1;
  497. p = v = va;
  498. while(n > 0) {
  499. if((p-v)+n > len)
  500. n = len - (p-v);
  501. memmove(p, tftpb.data, n);
  502. p += n;
  503. if(n != Segsize)
  504. break;
  505. if((n = tftpread(f->fs->dev, &server, &tftpb, sizeof(tftpb.data))) < 0)
  506. return -1;
  507. }
  508. return p-v;
  509. }
  510. static int
  511. pxewalk(File* f, char* name)
  512. {
  513. Bootp rep;
  514. char *ini;
  515. switch(f->walked){
  516. default:
  517. return -1;
  518. case 0:
  519. if(strcmp(name, "cfg") == 0){
  520. f->walked = 1;
  521. return 1;
  522. }
  523. break;
  524. case 1:
  525. if(strcmp(name, "pxe") == 0){
  526. f->walked = 2;
  527. return 1;
  528. }
  529. break;
  530. case 2:
  531. if(strcmp(name, "%E") != 0)
  532. break;
  533. f->walked = 3;
  534. if(bootpopen(f->fs->dev, nil, &rep, 0) < 0)
  535. return 0;
  536. ini = pxether[f->fs->dev].ini;
  537. /* use our mac address instead of relying on a bootp answer */
  538. snprint(ini, INIPATHLEN, "/cfg/pxe/%E", (uchar *)myaddr.ea);
  539. f->path = ini;
  540. return 1;
  541. }
  542. return 0;
  543. }
  544. void*
  545. pxegetfspart(int ctlrno, char* part, int)
  546. {
  547. if(!pxe)
  548. return nil;
  549. if(strcmp(part, "*") != 0)
  550. return nil;
  551. if(ctlrno >= MaxEther)
  552. return nil;
  553. pxether[ctlrno].fs.dev = ctlrno;
  554. pxether[ctlrno].fs.diskread = pxediskread;
  555. pxether[ctlrno].fs.diskseek = pxediskseek;
  556. pxether[ctlrno].fs.read = pxeread;
  557. pxether[ctlrno].fs.walk = pxewalk;
  558. pxether[ctlrno].fs.root.fs = &pxether[ctlrno].fs;
  559. pxether[ctlrno].fs.root.walked = 0;
  560. return &pxether[ctlrno].fs;
  561. }