Detect duplicates in upstream data, start frag at zero

This commit is contained in:
Erik Ekman 2008-12-14 17:21:27 +00:00 committed by Erik Ekman
parent 8d27febc7d
commit cc075124fa
2 changed files with 22 additions and 5 deletions

View file

@ -301,7 +301,6 @@ send_chunk(int fd)
avail = packet.len - packet.offset; avail = packet.len - packet.offset;
packet.sentlen = build_hostname(buf + 4, sizeof(buf) - 4, p, avail, topdomain, dataenc); packet.sentlen = build_hostname(buf + 4, sizeof(buf) - 4, p, avail, topdomain, dataenc);
packet.fragment++;
/* Build upstream data header (see doc/proto_xxxxxxxx.txt) */ /* Build upstream data header (see doc/proto_xxxxxxxx.txt) */
@ -316,6 +315,7 @@ send_chunk(int fd)
code = (0 << 1) | (packet.sentlen == avail); code = (0 << 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++;
send_query(fd, buf); send_query(fd, buf);
} }

View file

@ -113,6 +113,8 @@ tunnel_tun(int tun_fd, int dns_fd)
if (users[userid].outpacket.len == 0) { if (users[userid].outpacket.len == 0) {
memcpy(users[userid].outpacket.data, out, outlen); memcpy(users[userid].outpacket.data, out, outlen);
users[userid].outpacket.len = outlen; users[userid].outpacket.len = outlen;
users[userid].outpacket.seqno++;
users[userid].outpacket.fragment = 0;
return outlen; return outlen;
} else { } else {
return 0; return 0;
@ -170,7 +172,8 @@ update_downstream_seqno(int dns_fd, int userid, int down_seq, int down_frag)
if (users[userid].outpacket.len > 0) { if (users[userid].outpacket.len > 0) {
if (debug >= 1) { if (debug >= 1) {
printf("OUT pkt seq# %d, frag %d (last=%d), fragsize %d of total %d, to user %d\n", printf("OUT pkt seq# %d, frag %d (last=%d), fragsize %d of total %d, to user %d\n",
0, 0, 1, users[userid].outpacket.len, users[userid].outpacket.len, userid); users[userid].outpacket.seqno & 7, users[userid].outpacket.fragment & 15,
1, users[userid].outpacket.len, users[userid].outpacket.len, userid);
} }
write_dns(dns_fd, &users[userid].q, users[userid].outpacket.data, users[userid].outpacket.len); write_dns(dns_fd, &users[userid].q, users[userid].outpacket.data, users[userid].outpacket.len);
users[userid].outpacket.len = 0; users[userid].outpacket.len = 0;
@ -356,6 +359,17 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
users[userid].last_pkt = time(NULL); users[userid].last_pkt = time(NULL);
memcpy(&(users[userid].q), q, sizeof(struct query)); memcpy(&(users[userid].q), q, sizeof(struct query));
if (up_seq == users[userid].inpacket.seqno &&
up_frag <= users[userid].inpacket.fragment) {
/* Got repeated old packet, skip it */
if (debug >= 1) {
printf("IN pkt seq# %d, frag %d, dropped duplicate\n",
up_seq, up_frag);
}
/* Update seqno and maybe send immediate response packet */
update_downstream_seqno(dns_fd, userid, dn_seq, dn_frag);
return;
}
if (up_seq != users[userid].inpacket.seqno) { if (up_seq != users[userid].inpacket.seqno) {
/* New packet has arrived */ /* New packet has arrived */
users[userid].inpacket.seqno = up_seq; users[userid].inpacket.seqno = up_seq;
@ -604,9 +618,12 @@ tunnel(int tun_fd, int dns_fd, int bind_fd)
int j; int j;
for (j = 0; j < USERS; j++) { for (j = 0; j < USERS; j++) {
if (users[j].q.id != 0) { if (users[j].q.id != 0) {
if (debug >= 1) { if (debug >= 1 && users[j].outpacket.len > 0) {
printf("OUT pkt seq# %d, frag %d (last=%d), fragsize %d of total %d, to user %d\n", printf("OUT pkt seq# %d, frag %d (last=%d), "
0, 0, 1, users[j].outpacket.len, users[j].outpacket.len, j); "fragsize %d of total %d, to user %d\n",
users[j].outpacket.seqno & 7,
users[j].outpacket.fragment & 15, 1,
users[j].outpacket.len, users[j].outpacket.len, j);
} }
write_dns(dns_fd, &(users[j].q), users[j].outpacket.data, users[j].outpacket.len); write_dns(dns_fd, &(users[j].q), users[j].outpacket.data, users[j].outpacket.len);
users[j].outpacket.len = 0; users[j].outpacket.len = 0;