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add downstream data header and basic parsing in client, for #7

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Erik Ekman 2009-01-04 18:56:24 +00:00 committed by Erik Ekman
parent 3ed5f7e674
commit cc17083222
2 changed files with 32 additions and 5 deletions
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19
src/iodine.c
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@ -59,6 +59,8 @@ static struct sockaddr_in nameserv;
static char *topdomain; static char *topdomain;
static uint16_t rand_seed; static uint16_t rand_seed;
static int downstream_seqno;
static int downstream_fragment;
/* Current IP packet */ /* Current IP packet */
static struct packet packet; static struct packet packet;
@ -171,6 +173,12 @@ read_dns(int fd, char *buf, int buflen)
rv = dns_decode(buf, buflen, &q, QR_ANSWER, data, r); rv = dns_decode(buf, buflen, &q, QR_ANSWER, data, r);
/* decode the data header, update seqno and frag before next request */
if (rv > 2) {
downstream_seqno = (buf[1] >> 5) & 7;
downstream_fragment = (buf[1] >> 1) & 15;
}
if (is_sending() && chunkid == q.id) { if (is_sending() && chunkid == q.id) {
/* Got ACK on sent packet */ /* Got ACK on sent packet */
packet.offset += packet.sentlen; packet.offset += packet.sentlen;
@ -230,7 +238,9 @@ tunnel_dns(int tun_fd, int dns_fd)
outlen = sizeof(out); outlen = sizeof(out);
inlen = read; inlen = read;
if (uncompress((uint8_t*)out, &outlen, (uint8_t*)in, inlen) != Z_OK) {
/* Skip 2 byte data header and uncompress */
if (uncompress((uint8_t*)out, &outlen, (uint8_t*) &in[2], inlen - 2) != Z_OK) {
return -1; return -1;
} }
@ -309,10 +319,10 @@ send_chunk(int fd)
code = ((packet.seqno & 7) << 2) | ((packet.fragment & 15) >> 2); code = ((packet.seqno & 7) << 2) | ((packet.fragment & 15) >> 2);
buf[1] = b32_5to8(code); /* Second byte is 3 bits seqno, 2 upper bits fragment count */ buf[1] = b32_5to8(code); /* Second byte is 3 bits seqno, 2 upper bits fragment count */
code = ((packet.fragment & 3) << 3) | (0); code = ((packet.fragment & 3) << 3) | (downstream_seqno & 7);
buf[2] = b32_5to8(code); /* Third byte is 2 bits lower fragment count, 3 bits downstream packet seqno */ buf[2] = b32_5to8(code); /* Third byte is 2 bits lower fragment count, 3 bits downstream packet seqno */
code = (0 << 1) | (packet.sentlen == avail); code = ((downstream_fragment & 15) << 1) | (packet.sentlen == avail);
buf[3] = b32_5to8(code); /* Fourth byte is 4 bits downstream fragment count, 1 bit compression flag */ buf[3] = b32_5to8(code); /* Fourth byte is 4 bits downstream fragment count, 1 bit compression flag */
packet.fragment++; packet.fragment++;
@ -837,6 +847,9 @@ main(int argc, char **argv)
} }
} }
downstream_seqno = 0;
downstream_fragment = 0;
tunnel(tun_fd, dns_fd); tunnel(tun_fd, dns_fd);
cleanup2: cleanup2:

18
src/iodined.c
View file

@ -160,12 +160,26 @@ send_version_response(int fd, version_ack_t ack, uint32_t payload, int userid, s
static void static void
send_chunk(int dns_fd, int userid) { send_chunk(int dns_fd, int userid) {
char pkt[4096];
int datalen;
datalen = MIN(sizeof(pkt) - 2, users[userid].outpacket.len);
memcpy(&pkt[2], users[userid].outpacket.data, datalen);
/* Build downstream data header (see doc/proto_xxxxxxxx.txt) */
/* First byte is 1 bit compression flag, 3 bits upstream seqno, 4 bits upstream fragment */
pkt[0] = (1<<7) | ((users[userid].inpacket.seqno & 7) << 4) | (users[userid].inpacket.fragment & 15);
/* Second byte is 3 bits downstream seqno, 4 bits downstream fragment, 1 bit last flag */
pkt[1] = ((users[userid].outpacket.seqno & 7) << 5) | ((users[userid].outpacket.fragment & 15) << 1) | 1;
if (debug >= 1) { if (debug >= 1) {
printf("OUT pkt seq# %d, frag %d (last=%d), fragsize %d, total %d, to user %d\n", printf("OUT pkt seq# %d, frag %d (last=%d), fragsize %d, total %d, to user %d\n",
users[userid].outpacket.seqno & 7, users[userid].outpacket.fragment & 15, users[userid].outpacket.seqno & 7, users[userid].outpacket.fragment & 15,
1, users[userid].outpacket.len, users[userid].outpacket.len, userid); 1, users[userid].outpacket.len, datalen, userid);
} }
write_dns(dns_fd, &users[userid].q, users[userid].outpacket.data, users[userid].outpacket.len); write_dns(dns_fd, &users[userid].q, pkt, datalen + 2);
users[userid].outpacket.len = 0; users[userid].outpacket.len = 0;
users[userid].q.id = 0; users[userid].q.id = 0;
} }