mirror of
https://github.com/yarrick/iodine.git
synced 2024-12-25 00:57:46 +00:00
add downstream data header and basic parsing in client, for #7
This commit is contained in:
parent
7dd38fec17
commit
55d9ddb8dd
19
src/iodine.c
19
src/iodine.c
@ -59,6 +59,8 @@ static struct sockaddr_in nameserv;
|
||||
static char *topdomain;
|
||||
|
||||
static uint16_t rand_seed;
|
||||
static int downstream_seqno;
|
||||
static int downstream_fragment;
|
||||
|
||||
/* Current IP 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);
|
||||
|
||||
/* 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) {
|
||||
/* Got ACK on sent packet */
|
||||
packet.offset += packet.sentlen;
|
||||
@ -230,7 +238,9 @@ tunnel_dns(int tun_fd, int dns_fd)
|
||||
|
||||
outlen = sizeof(out);
|
||||
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;
|
||||
}
|
||||
|
||||
@ -309,10 +319,10 @@ send_chunk(int fd)
|
||||
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 */
|
||||
|
||||
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 */
|
||||
|
||||
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 */
|
||||
|
||||
packet.fragment++;
|
||||
@ -837,6 +847,9 @@ main(int argc, char **argv)
|
||||
}
|
||||
}
|
||||
|
||||
downstream_seqno = 0;
|
||||
downstream_fragment = 0;
|
||||
|
||||
tunnel(tun_fd, dns_fd);
|
||||
|
||||
cleanup2:
|
||||
|
@ -160,12 +160,26 @@ send_version_response(int fd, version_ack_t ack, uint32_t payload, int userid, s
|
||||
|
||||
static void
|
||||
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) {
|
||||
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,
|
||||
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].q.id = 0;
|
||||
}
|
||||
|
Loading…
x
Reference in New Issue
Block a user