From 8d27febc7d9f6cdb97215e6a06438931ef5b323c Mon Sep 17 00:00:00 2001
From: Erik Ekman <yarrick@kryo.se>
Date: Thu, 11 Dec 2008 22:39:06 +0000
Subject: [PATCH] Implemented new protocol for upstream data
---
doc/proto_00000403.txt | 29 ++++----
src/encoding.c | 4 +-
src/iodine.c | 52 ++++++++------
src/iodined.c | 151 +++++++++++++++++++++++++++++------------
src/user.c | 2 +
src/user.h | 4 +-
6 files changed, 161 insertions(+), 81 deletions(-)
diff --git a/doc/proto_00000403.txt b/doc/proto_00000403.txt
index c392079..cf05d94 100644
--- a/doc/proto_00000403.txt
+++ b/doc/proto_00000403.txt
@@ -38,8 +38,8 @@ Server replies:
Switch codec:
Client sends:
First byte s or S
- One byte ASCII digit, meaning userid
- One byte ASCII digit, with value 5 or 6, representing number of raw
+ 5 bits coded as Base32 char, meaning userid
+ 5 bits coded as Base32 char, with value 5 or 6, representing number of raw
bits per encoded byte
Server sends:
Name of codec if accepted. After this all upstream data packets must
@@ -47,28 +47,28 @@ Server sends:
BADCODEC if not accepted. Client must then revert to Base32
Data:
-Upstream data header (encoded as 4 bytes Base32):
- 4321 0 432 10 43 210 4321 0
- +----+-+---+--+--+---+----+-+
- |UUUU|L|SSS|FF|FF|DDD|GGGG|C|
- +----+-+---+--+--+---+----+-+
+Upstream data header:
+ 3210 432 10 43 210 4321 0
+ +----+---+--+--+---+----+-+
+ |UUUU|SSS|FF|FF|DDD|GGGG|L|
+ +----+---+--+--+---+----+-+
Downstream data header:
7 654 3210 765 4321 0
+-+---+----+---+----+-+
- |L|SSS|FFFF|DDD|GGGG|C|
+ |C|SSS|FFFF|DDD|GGGG|L|
+-+---+----+---+----+-+
UUUU = Userid
L = Last fragment in packet flag
-SSS = Upstream packet sequence number
+SS = Upstream packet sequence number
FFFF = Upstream fragment number
DDD = Downstream packet sequence number
GGGG = Downstream fragment number
-C = Compression enabled for this packet
+C = Compression enabled for downstream packet
-Upstream data packet starts with 4 bytes Base32 encoded header, then comes
-the payload data, encoded with chosen codec.
+Upstream data packet starts with 1 byte ASCII hex coded user byte, then 3 bytes
+Base32 encoded header, then comes the payload data, encoded with chosen codec.
Downstream data starts with 2 byte header. Then payload data, which may be
compressed.
@@ -77,7 +77,10 @@ Ping:
Client sends:
First byte p or P
Rest encoded with Base32:
- 1 byte userid
+ 1 byte with 4 bits userid
+ 1 byte with:
+ 3 bits downstream seqno
+ 4 bits downstream fragment
CMC
The server response to Ping and Data packets is a DNS NULL type response:
diff --git a/src/encoding.c b/src/encoding.c
index d581587..c3c94fb 100644
--- a/src/encoding.c
+++ b/src/encoding.c
@@ -35,7 +35,7 @@ inline_dotify(char *buf, size_t buflen)
char *reader, *writer;
total = strlen(buf);
- dots = total / 62;
+ dots = total / 57;
writer = buf;
writer += total;
@@ -52,7 +52,7 @@ inline_dotify(char *buf, size_t buflen)
pos = (unsigned) (reader - buf) + 1;
while (dots) {
- if (pos % 62 == 0) {
+ if (pos % 57 == 0) {
*writer-- = '.';
dots--;
}
diff --git a/src/iodine.c b/src/iodine.c
index 6905f26..ac52e04 100644
--- a/src/iodine.c
+++ b/src/iodine.c
@@ -124,10 +124,9 @@ build_hostname(char *buf, size_t buflen,
size_t space;
char *b;
-
- space = MIN(0xFF, buflen) - strlen(topdomain) - 2;
+ space = MIN(0xFF, buflen) - strlen(topdomain) - 5;
if (!encoder->places_dots())
- space -= (space / 62); /* space for dots */
+ space -= (space / 57); /* space for dots */
memset(buf, 0, buflen);
@@ -209,6 +208,8 @@ tunnel_tun(int tun_fd, int dns_fd)
packet.sentlen = 0;
packet.offset = 0;
packet.len = outlen;
+ packet.seqno++;
+ packet.fragment = 0;
send_chunk(dns_fd);
@@ -254,9 +255,11 @@ tunnel(int tun_fd, int dns_fd)
tv.tv_sec = 1;
tv.tv_usec = 0;
+
FD_ZERO(&fds);
- if (!is_sending())
+ if (!is_sending()) {
FD_SET(tun_fd, &fds);
+ }
FD_SET(dns_fd, &fds);
i = select(MAX(tun_fd, dns_fd) + 1, &fds, NULL, NULL, &tv);
@@ -297,15 +300,21 @@ send_chunk(int fd)
p += packet.offset;
avail = packet.len - packet.offset;
- packet.sentlen = build_hostname(buf + 1, sizeof(buf) - 1, p, avail, topdomain, dataenc);
+ packet.sentlen = build_hostname(buf + 4, sizeof(buf) - 4, p, avail, topdomain, dataenc);
+ packet.fragment++;
- if (packet.sentlen == avail)
- code = 1;
- else
- code = 0;
-
- code |= (userid << 1);
- buf[0] = hex[code];
+ /* Build upstream data header (see doc/proto_xxxxxxxx.txt) */
+
+ buf[0] = hex[userid & 15]; /* First byte is 4 bits userid */
+
+ 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);
+ buf[2] = b32_5to8(code); /* Third byte is 2 bits lower fragment count, 3 bits downstream packet seqno */
+
+ code = (0 << 1) | (packet.sentlen == avail);
+ buf[3] = b32_5to8(code); /* Fourth byte is 4 bits downstream fragment count, 1 bit compression flag */
send_query(fd, buf);
}
@@ -330,7 +339,7 @@ send_login(int fd, char *login, int len)
static void
send_ping(int fd)
{
- char data[3];
+ char data[4];
if (is_sending()) {
packet.sentlen = 0;
@@ -339,8 +348,9 @@ send_ping(int fd)
}
data[0] = userid;
- data[1] = (rand_seed >> 8) & 0xff;
- data[2] = (rand_seed >> 0) & 0xff;
+ data[1] = 0;
+ data[2] = (rand_seed >> 8) & 0xff;
+ data[3] = (rand_seed >> 0) & 0xff;
rand_seed++;
@@ -380,13 +390,9 @@ send_case_check(int fd)
static void
send_codec_switch(int fd, int userid, int bits)
{
- char buf[512] = "S00.";
- if (userid >= 0 && userid < 9) {
- buf[1] += userid;
- }
- if (bits >= 0 && bits < 9) {
- buf[2] += bits;
- }
+ char buf[512] = "S__.";
+ buf[1] = b32_5to8(userid);
+ buf[2] = b32_5to8(bits);
strncat(buf, topdomain, 512 - strlen(buf));
send_query(fd, buf);
@@ -705,6 +711,8 @@ main(int argc, char **argv)
device = NULL;
chunkid = 0;
+ packet.seqno = 0;
+
b32 = get_base32_encoder();
dataenc = get_base32_encoder();
diff --git a/src/iodined.c b/src/iodined.c
index 3ddb752..2750877 100644
--- a/src/iodined.c
+++ b/src/iodined.c
@@ -151,6 +151,33 @@ send_version_response(int fd, version_ack_t ack, uint32_t payload, int userid, s
write_dns(fd, q, out, sizeof(out));
}
+static void
+update_downstream_seqno(int dns_fd, int userid, int down_seq, int down_frag)
+{
+ /* update outgoing seqno/frag */
+ if (down_seq != users[userid].out_acked_seqno) {
+ /* First ack on new outgoing packet */
+ users[userid].out_acked_seqno = down_seq;
+ users[userid].out_acked_fragment = down_frag;
+ } else {
+ if (down_frag > users[userid].out_acked_fragment) {
+ /* Ack on later fragment */
+ users[userid].out_acked_fragment = down_frag;
+ }
+ }
+
+ /* Send reply if waiting */
+ if (users[userid].outpacket.len > 0) {
+ if (debug >= 1) {
+ 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);
+ }
+ write_dns(dns_fd, &users[userid].q, users[userid].outpacket.data, users[userid].outpacket.len);
+ users[userid].outpacket.len = 0;
+ users[userid].q.id = 0;
+ }
+}
+
static void
handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
{
@@ -240,16 +267,6 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
}
}
return;
- } else if(in[0] == 'P' || in[0] == 'p') {
- read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), domain_len - 1, b32);
- /* Ping packet, store userid */
- userid = unpacked[0];
- if (userid < 0 || userid >= USERS || ip_cmp(userid, q) != 0) {
- write_dns(dns_fd, q, "BADIP", 5);
- return; /* illegal id */
- }
- memcpy(&(users[userid].q), q, sizeof(struct query));
- users[userid].last_pkt = time(NULL);
} else if(in[0] == 'Z' || in[0] == 'z') {
/* Check for case conservation and chars not allowed according to RFC */
@@ -264,14 +281,15 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
return;
}
- userid = in[1] & 0x7;
+ userid = b32_8to5(in[1]);
if (ip_cmp(userid, q) != 0) {
write_dns(dns_fd, q, "BADIP", 5);
return; /* illegal id */
}
- codec = in[2] & 0xF;
+ codec = b32_8to5(in[2]);
+
switch (codec) {
case 5: /* 5 bits per byte = base32 */
enc = get_base32_encoder();
@@ -288,6 +306,25 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
break;
}
return;
+ } else if(in[0] == 'P' || in[0] == 'p') {
+ int dn_seq;
+ int dn_frag;
+
+ read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), domain_len - 1, b32);
+ /* Ping packet, store userid */
+ userid = unpacked[0];
+ if (userid < 0 || userid >= USERS || ip_cmp(userid, q) != 0) {
+ write_dns(dns_fd, q, "BADIP", 5);
+ return; /* illegal id */
+ }
+
+ dn_seq = unpacked[1] >> 4;
+ dn_frag = unpacked[1] & 15;
+ memcpy(&(users[userid].q), q, sizeof(struct query));
+ users[userid].last_pkt = time(NULL);
+
+ /* Update seqno and maybe send immediate response packet */
+ update_downstream_seqno(dns_fd, userid, dn_seq, dn_frag);
} else if((in[0] >= '0' && in[0] <= '9')
|| (in[0] >= 'a' && in[0] <= 'f')
|| (in[0] >= 'A' && in[0] <= 'F')) {
@@ -298,7 +335,7 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
if ((in[0] >= 'A' && in[0] <= 'F'))
code = in[0] - 'A' + 10;
- userid = code >> 1;
+ userid = code;
if (userid < 0 || userid >= USERS) {
write_dns(dns_fd, q, "BADIP", 5);
return; /* illegal id */
@@ -308,45 +345,69 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
if (check_ip && ip_cmp(userid, q) != 0) {
write_dns(dns_fd, q, "BADIP", 5);
} else {
- /* decode with this users encoding */
- read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), domain_len - 1,
- users[userid].encoder);
+ /* Decode data header */
+ int up_seq = (b32_8to5(in[1]) >> 2) & 7;
+ int up_frag = ((b32_8to5(in[1]) & 3) << 2) | ((b32_8to5(in[2]) >> 3) & 3);
+ int dn_seq = (b32_8to5(in[2]) & 7);
+ int dn_frag = b32_8to5(in[3]) >> 1;
+ int lastfrag = b32_8to5(in[3]) & 1;
+ /* Update query and time info for user */
users[userid].last_pkt = time(NULL);
memcpy(&(users[userid].q), q, sizeof(struct query));
+
+ if (up_seq != users[userid].inpacket.seqno) {
+ /* New packet has arrived */
+ users[userid].inpacket.seqno = up_seq;
+ users[userid].inpacket.len = 0;
+ users[userid].inpacket.offset = 0;
+ }
+ users[userid].inpacket.fragment = up_frag;
+
+ /* decode with this users encoding */
+ read = unpack_data(unpacked, sizeof(unpacked), &(in[4]), domain_len - 4,
+ users[userid].encoder);
+
+ /* copy to packet buffer, update length */
memcpy(users[userid].inpacket.data + users[userid].inpacket.offset, unpacked, read);
users[userid].inpacket.len += read;
users[userid].inpacket.offset += read;
- if (code & 1) {
+ if (debug >= 1) {
+ printf("IN pkt seq# %d, frag %d (last=%d), fragsize %d, total %d, from user %d\n",
+ up_seq, up_frag, lastfrag, read, users[userid].inpacket.len, userid);
+ }
+
+ if (lastfrag & 1) { /* packet is complete */
+ int ret;
outlen = sizeof(out);
- uncompress((uint8_t*)out, &outlen,
- (uint8_t*)users[userid].inpacket.data, users[userid].inpacket.len);
+ ret = uncompress((uint8_t*)out, &outlen,
+ (uint8_t*)users[userid].inpacket.data, users[userid].inpacket.len);
- hdr = (struct ip*) (out + 4);
- touser = find_user_by_ip(hdr->ip_dst.s_addr);
+ if (ret == Z_OK) {
+ hdr = (struct ip*) (out + 4);
+ touser = find_user_by_ip(hdr->ip_dst.s_addr);
- if (touser == -1) {
- /* send the uncompressed packet to tun device */
- write_tun(tun_fd, out, outlen);
- } else {
- /* send the compressed packet to other client
- * if another packet is queued, throw away this one. TODO build queue */
- if (users[touser].outpacket.len == 0) {
- memcpy(users[touser].outpacket.data, users[userid].inpacket.data, users[userid].inpacket.len);
- users[touser].outpacket.len = users[userid].inpacket.len;
+ if (touser == -1) {
+ /* send the uncompressed packet to tun device */
+ write_tun(tun_fd, out, outlen);
+ } else {
+ /* send the compressed packet to other client
+ * if another packet is queued, throw away this one. TODO build queue */
+ if (users[touser].outpacket.len == 0) {
+ memcpy(users[touser].outpacket.data, users[userid].inpacket.data, users[userid].inpacket.len);
+ users[touser].outpacket.len = users[userid].inpacket.len;
+ }
}
+ } else {
+ printf("Discarded data, uncompress() result: %d\n", ret);
}
users[userid].inpacket.len = users[userid].inpacket.offset = 0;
}
+ /* Update seqno and maybe send immediate response packet */
+ update_downstream_seqno(dns_fd, userid, dn_seq, dn_frag);
}
}
- /* userid must be set for a reply to be sent */
- if (userid >= 0 && userid < USERS && ip_cmp(userid, q) == 0 && users[userid].outpacket.len > 0) {
- write_dns(dns_fd, q, users[userid].outpacket.data, users[userid].outpacket.len);
- users[userid].outpacket.len = 0;
- users[userid].q.id = 0;
- }
}
static void
@@ -361,7 +422,7 @@ handle_ns_request(int dns_fd, struct query *q)
len = dns_encode_ns_response(buf, sizeof(buf), q, topdomain);
- if (debug >= 1) {
+ if (debug >= 2) {
struct sockaddr_in *tempin;
tempin = (struct sockaddr_in *) &(q->from);
printf("TX: client %s, type %d, name %s, %d bytes NS reply\n",
@@ -394,7 +455,7 @@ forward_query(int bind_fd, struct query *q)
memcpy(&(myaddr->sin_addr), &newaddr, sizeof(in_addr_t));
myaddr->sin_port = htons(bind_port);
- if (debug >= 1) {
+ if (debug >= 2) {
printf("TX: NS reply \n");
}
@@ -422,18 +483,18 @@ tunnel_bind(int bind_fd, int dns_fd)
id = dns_get_id(packet, r);
- if (debug >= 1) {
+ if (debug >= 2) {
printf("RX: Got response on query %u from DNS\n", (id & 0xFFFF));
}
/* Get sockaddr from id */
fw_query_get(id, &query);
- if (!query && debug >= 1) {
+ if (!query && debug >= 2) {
printf("Lost sender of id %u, dropping reply\n", (id & 0xFFFF));
return 0;
}
- if (debug >= 1) {
+ if (debug >= 2) {
struct sockaddr_in *in;
in = (struct sockaddr_in *) &(query->addr);
printf("TX: client %s id %u, %d bytes\n",
@@ -460,7 +521,7 @@ tunnel_dns(int tun_fd, int dns_fd, int bind_fd)
if ((read = read_dns(dns_fd, &q)) <= 0)
return 0;
- if (debug >= 1) {
+ if (debug >= 2) {
struct sockaddr_in *tempin;
tempin = (struct sockaddr_in *) &(q.from);
printf("RX: client %s, type %d, name %s\n",
@@ -543,6 +604,10 @@ tunnel(int tun_fd, int dns_fd, int bind_fd)
int j;
for (j = 0; j < USERS; j++) {
if (users[j].q.id != 0) {
+ if (debug >= 1) {
+ printf("OUT pkt seq# %d, frag %d (last=%d), fragsize %d of total %d, to user %d\n",
+ 0, 0, 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);
users[j].outpacket.len = 0;
users[j].q.id = 0;
@@ -626,7 +691,7 @@ write_dns(int fd, struct query *q, char *data, int datalen)
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, data, datalen);
- if (debug >= 1) {
+ if (debug >= 2) {
struct sockaddr_in *tempin;
tempin = (struct sockaddr_in *) &(q->from);
printf("TX: client %s, type %d, name %s, %d bytes data\n",
diff --git a/src/user.c b/src/user.c
index c23d9c7..cc6a883 100644
--- a/src/user.c
+++ b/src/user.c
@@ -50,6 +50,8 @@ init_users(in_addr_t my_ip)
users[i].inpacket.offset = 0;
users[i].outpacket.len = 0;
users[i].q.id = 0;
+ users[i].out_acked_seqno = 0;
+ users[i].out_acked_fragment = 0;
}
}
diff --git a/src/user.h b/src/user.h
index 8f1250c..0dc7cc2 100644
--- a/src/user.h
+++ b/src/user.h
@@ -17,7 +17,7 @@
#ifndef __USER_H__
#define __USER_H__
-#define USERS 8
+#define USERS 16
struct user {
char id;
@@ -30,6 +30,8 @@ struct user {
struct packet inpacket;
struct packet outpacket;
struct encoder *encoder;
+ int out_acked_seqno;
+ int out_acked_fragment;
};
extern struct user users[USERS];