1: /*************************************************************************
2: * (C) 2011 AITNET - Sofia/Bulgaria - <office@aitnet.org>
3: * by Michael Pounov <misho@elwix.org>
4: *
5: * $Author: misho $
6: * $Id: utils.c,v 1.1.1.1.2.5 2011/10/13 11:01:37 misho Exp $
7: *
8: *************************************************************************/
9: #include "global.h"
10:
11:
12: void
13: Get1stEth(char *psDev, int devlen)
14: {
15: struct ifaddrs *ifa;
16:
17: assert(psDev);
18: assert(devlen > 0);
19:
20: getifaddrs(&ifa);
21: strlcpy(psDev, ifa->ifa_name, devlen);
22: freeifaddrs(ifa);
23: }
24:
25: int
26: PrepareL2(const char *psDev, int *bpflen)
27: {
28: int h, n = 1;
29: register int i;
30: char szStr[STRSIZ];
31: struct ifreq ifr;
32: struct bpf_program fcode = { 0 };
33: struct bpf_insn insns[] = {
34: BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 12),
35: BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ANSH_ID, 0, 1),
36: BPF_STMT(BPF_RET + BPF_K, -1),
37: BPF_STMT(BPF_RET + BPF_K, 0),
38: };
39:
40: FTRACE(3);
41: assert(psDev);
42:
43: fcode.bf_len = sizeof(insns) / sizeof(struct bpf_insn);
44: fcode.bf_insns = insns;
45:
46: for (i = 0; i < 10; i++) {
47: memset(szStr, 0, sizeof szStr);
48: snprintf(szStr, sizeof szStr, "/dev/bpf%d", i);
49: h = open(szStr, O_RDWR);
50: if (h > 2)
51: break;
52: }
53: if (h < 3) {
54: printf("Error:: open bpf %s #%d - %s\n", szStr, errno, strerror(errno));
55: return -1;
56: }
57:
58: if (ioctl(h, BIOCIMMEDIATE, &n) == -1) {
59: printf("Error:: set interface %s to bpf #%d - %s\n", psDev, errno, strerror(errno));
60: close(h);
61: return -1;
62: }
63: strlcpy(ifr.ifr_name, psDev, sizeof ifr.ifr_name);
64: if (ioctl(h, BIOCSETIF, &ifr) == -1) {
65: printf("Error:: bind interface %s to bpf #%d - %s\n", psDev, errno, strerror(errno));
66: close(h);
67: return -1;
68: }
69: if (ioctl(h, BIOCSETF, &fcode) == -1) {
70: printf("Error:: set filter interface %s to bpf #%d - %s\n", psDev, errno, strerror(errno));
71: close(h);
72: return -1;
73: }
74: if (ioctl(h, BIOCGBLEN, bpflen) == -1) {
75: printf("Error:: get interface %s buffer length #%d - %s\n", psDev, errno, strerror(errno));
76: close(h);
77: return -1;
78: }
79:
80: /*
81: n = fcntl(h, F_GETFL);
82: fcntl(h, F_SETFL, n | O_NONBLOCK);
83: */
84:
85: VERB(3) LOG("Openned device handle %d with bpf buflen %d", h, *bpflen);
86: return h;
87: }
88:
89: int
90: PrepareL3(const struct sockaddr *sa, int *bpflen)
91: {
92: int h, n = 1;
93:
94: FTRACE(3);
95: assert(sa);
96:
97: h = socket(sa->sa_family, SOCK_RAW, IPPROTO_ICMP);
98: if (h == -1) {
99: printf("Error:: Cant open raw socket #%d - %s\n", errno, strerror(errno));
100: return -1;
101: }
102: /*
103: if (setsockopt(h, SOL_SOCKET, SO_REUSEADDR, &n, sizeof n) == -1) {
104: printf("Error:: Cant set raw socket #%d - %s\n", errno, strerror(errno));
105: close(h);
106: return -1;
107: }
108: */
109: if (bind(h, sa, sizeof(struct sockaddr)) == -1) {
110: printf("Error:: Cant bind to raw socket #%d - %s\n", errno, strerror(errno));
111: close(h);
112: return -1;
113: }
114:
115: n = fcntl(h, F_GETFL);
116: fcntl(h, F_SETFL, n | O_NONBLOCK);
117:
118: *bpflen = USHRT_MAX;
119: VERB(3) LOG("Openned socket handle %d", h);
120: return h;
121: }
122:
123: char
124: icmpRecv(int s, u_short * __restrict id, u_int * __restrict crypted, u_char * __restrict data,
125: int * __restrict datlen, struct sockaddr *sa, socklen_t *salen)
126: {
127: int ret = 0;
128: struct icmp *icmp;
129: struct ansh_hdr *hdr;
130: u_char buf[USHRT_MAX] = { 0 };
131: u_int crc;
132:
133: ret = recvfrom(s, buf, sizeof buf, 0, sa, salen);
134: if (ret == -1) {
135: ERR("Receive recvfrom() #%d - %s", errno, strerror(errno));
136: return ANSH_FLG_ERR;
137: } else
138: VERB(4) LOG("Get packet with len=%d", ret);
139:
140: /* check header len */
141: if (ret < (sizeof(struct ip) + sizeof(struct icmp) + sizeof(struct ansh_hdr))) {
142: VERB(1) LOG("Discard packet too short %d ...", ret);
143: return ANSH_FLG_ERR;
144: } else
145: icmp = (struct icmp*) (buf + sizeof(struct ip));
146:
147: /* check echo magic ansh code */
148: if (icmp->icmp_type != ICMP_ECHOREPLY || icmp->icmp_code != ANSH_CODE) {
149: VERB(3) LOG("Packet isnt for me %d ... icmp_code=%d", ret, icmp->icmp_code);
150: return ANSH_FLG_ERR;
151: } else
152: hdr = (struct ansh_hdr*) (buf + sizeof(struct ip) + sizeof(struct icmp));
153:
154: /* check version and total size of packet */
155: if (hdr->ansh_ver != ANSH_VERSION) {
156: VERB(3) LOG("Packet with wrong version ...");
157: return ANSH_FLG_ERR;
158: }
159: if (crypted) {
160: if (hdr->ansh_nonce && !*crypted) {
161: VERB(3) LOG("Channel INSECURED:: Crypted communication not supported at this moment ...");
162: return ANSH_FLG_ERR;
163: }
164: if (!hdr->ansh_nonce && *crypted) {
165: VERB(3) LOG("Channel SECURED:: Plain text communication not supported at this moment ...");
166: return ANSH_FLG_ERR;
167: }
168:
169: *crypted = ntohl(hdr->ansh_nonce);
170: }
171:
172: /* check crc of packet */
173: crc = hdr->ansh_crc;
174: hdr->ansh_crc ^= hdr->ansh_crc;
175: hdr->ansh_crc = htonl(crcAdler((u_char*) hdr, ntohs(hdr->ansh_len)));
176: if (crc != hdr->ansh_crc) {
177: VERB(3) LOG("Packet with wrong crc ...");
178: return ANSH_FLG_ERR;
179: }
180:
181: /* copy data */
182: if (data && datlen) {
183: memset(data, 0, *datlen);
184: *datlen = ntohs(hdr->ansh_len) - sizeof(struct ansh_hdr);
185: memcpy(data, buf + sizeof(struct ip) + sizeof(struct icmp) + sizeof(struct ansh_hdr), *datlen);
186: }
187:
188: if (id)
189: *id = ntohs(icmp->icmp_id);
190: return hdr->ansh_flg;
191: }
192:
193: int
194: icmpSend(int s, u_short id, char flg, u_int crypted, u_char *data, int datlen, struct sockaddr *sa, socklen_t salen)
195: {
196: u_char *pos, buf[USHRT_MAX] = { 0 };
197: struct icmp *icmp;
198: struct ansh_hdr *hdr;
199: int ret = 0;
200:
201: assert(data);
202: if ((sizeof buf - sizeof(struct icmp) + sizeof(struct ansh_hdr)) < datlen)
203: return ANSH_FLG_ERR;
204:
205: icmp = (struct icmp*) buf;
206: hdr = (struct ansh_hdr*) (buf + sizeof(struct icmp));
207: pos = buf + sizeof(struct icmp) + sizeof(struct ansh_hdr);
208:
209: memcpy(pos, data, datlen);
210:
211: hdr->ansh_ver = ANSH_VERSION;
212: hdr->ansh_flg = flg;
213: hdr->ansh_len = htons(datlen + sizeof(struct ansh_hdr));
214: hdr->ansh_nonce = htonl(crypted);
215: hdr->ansh_crc = 0;
216: hdr->ansh_crc = htonl(crcAdler((u_char*) hdr, ntohs(hdr->ansh_len)));
217:
218: icmp->icmp_type = ICMP_ECHOREPLY;
219: icmp->icmp_code = ANSH_CODE;
220: icmp->icmp_id = htons(id);
221: icmp->icmp_seq = htons(datlen);
222: icmp->icmp_cksum = 0;
223: icmp->icmp_cksum = crcIP(buf, sizeof(struct icmp) + sizeof(struct ansh_hdr) + datlen);
224:
225: if ((ret = sendto(s, buf, sizeof(struct icmp) + sizeof(struct ansh_hdr) + datlen,
226: 0, sa, salen)) == -1) {
227: ERR("Send sendto() #%d - %s", errno, strerror(errno));
228: return ANSH_FLG_ERR;
229: } else
230: VERB(4) LOG("Put packet with len=%d", ret);
231: if (ret != sizeof(struct icmp) + sizeof(struct ansh_hdr) + datlen) {
232: VERB(3) LOG("Sended data %d is different from source data len %d", ret,
233: sizeof(struct icmp) + sizeof(struct ansh_hdr) + datlen);
234: return ANSH_FLG_ERR;
235: }
236:
237: return ret;
238: }
239:
240: static int
241: _pkt_Send(int s, char flg, u_int crypted, u_char *data, int datlen, struct ether_addr *ea)
242: {
243: u_char *pos, buf[USHRT_MAX] = { 0 };
244: struct ether_header *e = (struct ether_header*) buf;
245: struct ansh_hdr *hdr;
246: int ret = 0;
247:
248: assert(data);
249: if ((sizeof buf - ETHER_HDR_LEN + sizeof(struct ansh_hdr)) < datlen)
250: return ANSH_FLG_ERR;
251:
252: e->ether_type = ntohs(ANSH_ID);
253: memcpy(e->ether_dhost, ea->octet, ETHER_ADDR_LEN);
254: hdr = (struct ansh_hdr*) (buf + ETHER_HDR_LEN);
255: pos = ((u_char*) hdr) + sizeof(struct ansh_hdr);
256:
257: memcpy(pos, data, datlen);
258:
259: hdr->ansh_ver = ANSH_VERSION;
260: hdr->ansh_flg = flg;
261: hdr->ansh_len = htons(datlen + sizeof(struct ansh_hdr));
262: hdr->ansh_nonce = htonl(crypted);
263: hdr->ansh_crc = 0;
264: hdr->ansh_crc = htonl(crcAdler((u_char*) hdr, ntohs(hdr->ansh_len)));
265:
266: if ((ret = write(s, buf, ETHER_HDR_LEN + sizeof(struct ansh_hdr) + datlen)) == -1) {
267: ERR("Send packet() #%d - %s", errno, strerror(errno));
268: return ANSH_FLG_ERR;
269: } else
270: VERB(4) LOG("Put packet with len=%d", ret);
271: if (ret != ETHER_HDR_LEN + sizeof(struct ansh_hdr) + datlen) {
272: VERB(3) LOG("Sended data %d is different from source data len %d", ret,
273: ETHER_HDR_LEN + sizeof(struct ansh_hdr) + datlen);
274: return ANSH_FLG_ERR;
275: }
276:
277: return ret;
278: }
279:
280: int
281: pktSend(int s, char flg, u_int crypted, u_char *data, int datlen, struct ether_addr *ea)
282: {
283: int wlen, ret = 0;
284: u_char *pos = data;
285:
286: while (datlen > -1) {
287: wlen = _pkt_Send(s, flg, crypted, pos, (datlen > 512) ? 512 : datlen, ea);
288: if (wlen == -1)
289: return -1;
290: else {
291: pos += wlen;
292: datlen -= wlen;
293: ret += wlen;
294: }
295: }
296:
297: return ret;
298: }
299:
300: static char
301: _pkt_Recv(u_char * __restrict buf, int rlen, u_int * __restrict crypted,
302: u_char * __restrict data, int * __restrict datlen,
303: u_char ** __restrict next, int * __restrict nextlen)
304: {
305: int bias;
306: struct bpf_hdr *bpf;
307: struct ansh_hdr *hdr;
308: u_int crc;
309:
310: if (rlen < (sizeof(struct bpf_hdr) + ETHER_HDR_LEN + sizeof(struct ansh_hdr))) {
311: VERB(1) LOG("Discard packet too short %d ...", rlen);
312: return ANSH_FLG_ERR;
313: } else {
314: bpf = (struct bpf_hdr*) buf;
315: hdr = (struct ansh_hdr*) (buf + bpf->bh_hdrlen + ETHER_HDR_LEN);
316: }
317:
318: /* slice readed data to packets */
319: if ((bias = BPF_WORDALIGN(bpf->bh_hdrlen + bpf->bh_caplen)) < rlen) {
320: *next = buf + bias;
321: *nextlen = rlen - bias;
322: } else {
323: *next = NULL;
324: *nextlen = 0;
325: }
326:
327: /* check version and total size of packet */
328: if (hdr->ansh_ver != ANSH_VERSION) {
329: VERB(3) LOG("Packet with wrong version ... %d", hdr->ansh_ver);
330: return ANSH_FLG_ERR;
331: }
332: if (crypted) {
333: if (hdr->ansh_nonce && !*crypted) {
334: VERB(3) LOG("Channel INSECURED:: Crypted communication not supported at this moment ...");
335: return ANSH_FLG_ERR;
336: }
337: if (!hdr->ansh_nonce && *crypted) {
338: VERB(3) LOG("Channel SECURED:: Plain text communication not supported at this moment ...");
339: return ANSH_FLG_ERR;
340: }
341:
342: *crypted = ntohl(hdr->ansh_nonce);
343: }
344:
345: /* check crc of packet */
346: crc = hdr->ansh_crc;
347: hdr->ansh_crc ^= hdr->ansh_crc;
348: hdr->ansh_crc = htonl(crcAdler((u_char*) hdr, ntohs(hdr->ansh_len)));
349: if (crc != hdr->ansh_crc) {
350: VERB(3) LOG("Packet with wrong crc ...");
351: return ANSH_FLG_ERR;
352: }
353:
354: /* select data */
355: if (data) {
356: *datlen = ntohs(hdr->ansh_len) - sizeof(struct ansh_hdr);
357: memcpy(data, buf + bpf->bh_hdrlen + ETHER_HDR_LEN + sizeof(struct ansh_hdr), *datlen);
358: }
359:
360: return hdr->ansh_flg;
361: }
362:
363: char
364: pktRecv(int s, u_int * __restrict crypted, u_char * __restrict data, int * __restrict datlen,
365: struct ether_header *eth)
366: {
367: u_char *buf, *next, *pos, *ptr;
368: int nextlen, rlen, buflen, ptrlen;
369: char flg;
370: struct bpf_hdr *bpf;
371: struct ether_header *e;
372:
373: if (!eth || !datlen)
374: return ANSH_FLG_ERR;
375:
376: if (!(buf = malloc(*datlen))) {
377: ERR("malloc() #%d - %s", errno, strerror(errno));
378: return ANSH_FLG_ERR;
379: }
380:
381: rlen = read(s, buf, *datlen);
382: if (rlen == -1) {
383: ERR("Receive packet() #%d - %s", errno, strerror(errno));
384: free(buf);
385: return ANSH_FLG_ERR;
386: } else
387: VERB(4) LOG("Get packet with len=%d", rlen);
388:
389: /* check header len */
390: if (rlen < (sizeof(struct bpf_hdr) + ETHER_HDR_LEN + sizeof(struct ansh_hdr))) {
391: VERB(1) LOG("Discard packet too short %d ...", rlen);
392: free(buf);
393: return ANSH_FLG_ERR;
394: } else {
395: bpf = (struct bpf_hdr*) buf;
396: e = (struct ether_header*) (buf + bpf->bh_hdrlen);
397: memcpy(eth, e, ETHER_HDR_LEN);
398: }
399:
400: ptr = next = buf;
401: ptrlen = nextlen = rlen;
402: pos = data;
403: buflen = *datlen;
404: if ((flg = _pkt_Recv(ptr, ptrlen, crypted, pos, &buflen, &next, &nextlen)) == -1) {
405: free(buf);
406: return ANSH_FLG_ERR;
407: } else {
408: pos += buflen;
409: *datlen = buflen;
410: ptr = next;
411: ptrlen = nextlen;
412: }
413: while (next && nextlen > 0)
414: if (_pkt_Recv(ptr, ptrlen, crypted, pos, &buflen, &next, &nextlen) == -1)
415: break;
416: else {
417: pos += buflen;
418: *datlen += buflen;
419: ptr = next;
420: ptrlen = nextlen;
421: }
422:
423: free(buf);
424: return flg;
425: }
426:
427: void *
428: TOfunc(sched_task_t *task)
429: {
430: struct tagProc *proc;
431:
432: FTRACE(3);
433:
434: /* not found argument, drop data */
435: if (!(proc = TASK_ARG(task)))
436: return (void*) -1;
437:
438: if (proc->proc_pid)
439: kill(proc->proc_pid, SIGTERM);
440:
441: return NULL;
442: }
443:
444: u_char *
445: cryptBuffer(u_char *buf, int rlen, u_int ctr)
446: {
447: u_char *str, ivec[AES_BLOCK_SIZE] = { 0 };
448: u_int rctr = htonl(ctr);
449:
450: FTRACE(3);
451:
452: if (!buf)
453: return NULL;
454:
455: memcpy(ivec, &ctr, sizeof ctr);
456: memcpy(ivec + 4, &rctr, sizeof rctr);
457: memcpy(ivec + 8, &ctr, sizeof ctr);
458: memcpy(ivec + 12, &rctr, sizeof rctr);
459:
460: if (io_ctr_AES(buf, rlen, &str, (u_char*) "_ansh_ELWIX_", ivec) == -1)
461: return NULL;
462:
463: return str;
464: }
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