Implemented new protocol for upstream data
This commit is contained in:
Erik Ekman
Erik Ekman
parent
2c4c5ec1ba
commit
8d27febc7d
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@ -38,8 +38,8 @@ Server replies:
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Switch codec:
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Client sends:
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First byte s or S
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One byte ASCII digit, meaning userid
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One byte ASCII digit, with value 5 or 6, representing number of raw
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5 bits coded as Base32 char, meaning userid
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5 bits coded as Base32 char, with value 5 or 6, representing number of raw
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bits per encoded byte
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Server sends:
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Name of codec if accepted. After this all upstream data packets must
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@ -47,28 +47,28 @@ Server sends:
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BADCODEC if not accepted. Client must then revert to Base32
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Data:
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Upstream data header (encoded as 4 bytes Base32):
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4321 0 432 10 43 210 4321 0
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+----+-+---+--+--+---+----+-+
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|UUUU|L|SSS|FF|FF|DDD|GGGG|C|
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+----+-+---+--+--+---+----+-+
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Upstream data header:
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3210 432 10 43 210 4321 0
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+----+---+--+--+---+----+-+
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|UUUU|SSS|FF|FF|DDD|GGGG|L|
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+----+---+--+--+---+----+-+
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Downstream data header:
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7 654 3210 765 4321 0
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+-+---+----+---+----+-+
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|L|SSS|FFFF|DDD|GGGG|C|
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|C|SSS|FFFF|DDD|GGGG|L|
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+-+---+----+---+----+-+
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UUUU = Userid
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L = Last fragment in packet flag
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SSS = Upstream packet sequence number
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SS = Upstream packet sequence number
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FFFF = Upstream fragment number
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DDD = Downstream packet sequence number
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GGGG = Downstream fragment number
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C = Compression enabled for this packet
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C = Compression enabled for downstream packet
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Upstream data packet starts with 4 bytes Base32 encoded header, then comes
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the payload data, encoded with chosen codec.
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Upstream data packet starts with 1 byte ASCII hex coded user byte, then 3 bytes
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Base32 encoded header, then comes the payload data, encoded with chosen codec.
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Downstream data starts with 2 byte header. Then payload data, which may be
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compressed.
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@ -77,7 +77,10 @@ Ping:
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Client sends:
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First byte p or P
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Rest encoded with Base32:
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1 byte userid
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1 byte with 4 bits userid
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1 byte with:
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3 bits downstream seqno
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4 bits downstream fragment
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CMC
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The server response to Ping and Data packets is a DNS NULL type response:
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@ -35,7 +35,7 @@ inline_dotify(char *buf, size_t buflen)
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char *reader, *writer;
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total = strlen(buf);
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dots = total / 62;
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dots = total / 57;
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writer = buf;
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writer += total;
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@ -52,7 +52,7 @@ inline_dotify(char *buf, size_t buflen)
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pos = (unsigned) (reader - buf) + 1;
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while (dots) {
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if (pos % 62 == 0) {
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if (pos % 57 == 0) {
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*writer-- = '.';
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dots--;
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}
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50
src/iodine.c
50
src/iodine.c
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@ -124,10 +124,9 @@ build_hostname(char *buf, size_t buflen,
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size_t space;
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char *b;
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space = MIN(0xFF, buflen) - strlen(topdomain) - 2;
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space = MIN(0xFF, buflen) - strlen(topdomain) - 5;
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if (!encoder->places_dots())
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space -= (space / 62); /* space for dots */
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space -= (space / 57); /* space for dots */
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memset(buf, 0, buflen);
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@ -209,6 +208,8 @@ tunnel_tun(int tun_fd, int dns_fd)
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packet.sentlen = 0;
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packet.offset = 0;
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packet.len = outlen;
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packet.seqno++;
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packet.fragment = 0;
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send_chunk(dns_fd);
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@ -254,9 +255,11 @@ tunnel(int tun_fd, int dns_fd)
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tv.tv_sec = 1;
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tv.tv_usec = 0;
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FD_ZERO(&fds);
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if (!is_sending())
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if (!is_sending()) {
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FD_SET(tun_fd, &fds);
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}
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FD_SET(dns_fd, &fds);
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i = select(MAX(tun_fd, dns_fd) + 1, &fds, NULL, NULL, &tv);
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@ -297,15 +300,21 @@ send_chunk(int fd)
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p += packet.offset;
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avail = packet.len - packet.offset;
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packet.sentlen = build_hostname(buf + 1, sizeof(buf) - 1, p, avail, topdomain, dataenc);
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packet.sentlen = build_hostname(buf + 4, sizeof(buf) - 4, p, avail, topdomain, dataenc);
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packet.fragment++;
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if (packet.sentlen == avail)
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code = 1;
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else
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code = 0;
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/* Build upstream data header (see doc/proto_xxxxxxxx.txt) */
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code |= (userid << 1);
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buf[0] = hex[code];
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buf[0] = hex[userid & 15]; /* First byte is 4 bits userid */
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code = ((packet.seqno & 7) << 2) | ((packet.fragment & 15) >> 2);
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buf[1] = b32_5to8(code); /* Second byte is 3 bits seqno, 2 upper bits fragment count */
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code = ((packet.fragment & 3) << 3) | (0);
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buf[2] = b32_5to8(code); /* Third byte is 2 bits lower fragment count, 3 bits downstream packet seqno */
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code = (0 << 1) | (packet.sentlen == avail);
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buf[3] = b32_5to8(code); /* Fourth byte is 4 bits downstream fragment count, 1 bit compression flag */
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send_query(fd, buf);
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}
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@ -330,7 +339,7 @@ send_login(int fd, char *login, int len)
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static void
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send_ping(int fd)
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{
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char data[3];
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char data[4];
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if (is_sending()) {
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packet.sentlen = 0;
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@ -339,8 +348,9 @@ send_ping(int fd)
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}
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data[0] = userid;
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data[1] = (rand_seed >> 8) & 0xff;
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data[2] = (rand_seed >> 0) & 0xff;
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data[1] = 0;
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data[2] = (rand_seed >> 8) & 0xff;
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data[3] = (rand_seed >> 0) & 0xff;
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rand_seed++;
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@ -380,13 +390,9 @@ send_case_check(int fd)
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static void
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send_codec_switch(int fd, int userid, int bits)
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{
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char buf[512] = "S00.";
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if (userid >= 0 && userid < 9) {
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buf[1] += userid;
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}
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if (bits >= 0 && bits < 9) {
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buf[2] += bits;
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}
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char buf[512] = "S__.";
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buf[1] = b32_5to8(userid);
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buf[2] = b32_5to8(bits);
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strncat(buf, topdomain, 512 - strlen(buf));
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send_query(fd, buf);
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@ -705,6 +711,8 @@ main(int argc, char **argv)
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device = NULL;
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chunkid = 0;
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packet.seqno = 0;
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b32 = get_base32_encoder();
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dataenc = get_base32_encoder();
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127
src/iodined.c
127
src/iodined.c
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@ -151,6 +151,33 @@ send_version_response(int fd, version_ack_t ack, uint32_t payload, int userid, s
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write_dns(fd, q, out, sizeof(out));
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}
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static void
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update_downstream_seqno(int dns_fd, int userid, int down_seq, int down_frag)
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{
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/* update outgoing seqno/frag */
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if (down_seq != users[userid].out_acked_seqno) {
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/* First ack on new outgoing packet */
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users[userid].out_acked_seqno = down_seq;
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users[userid].out_acked_fragment = down_frag;
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} else {
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if (down_frag > users[userid].out_acked_fragment) {
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/* Ack on later fragment */
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users[userid].out_acked_fragment = down_frag;
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}
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}
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/* Send reply if waiting */
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if (users[userid].outpacket.len > 0) {
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if (debug >= 1) {
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printf("OUT pkt seq# %d, frag %d (last=%d), fragsize %d of total %d, to user %d\n",
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0, 0, 1, users[userid].outpacket.len, users[userid].outpacket.len, userid);
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}
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write_dns(dns_fd, &users[userid].q, users[userid].outpacket.data, users[userid].outpacket.len);
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users[userid].outpacket.len = 0;
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users[userid].q.id = 0;
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}
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}
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static void
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handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
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{
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@ -240,16 +267,6 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
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}
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}
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return;
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} else if(in[0] == 'P' || in[0] == 'p') {
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read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), domain_len - 1, b32);
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/* Ping packet, store userid */
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userid = unpacked[0];
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if (userid < 0 || userid >= USERS || ip_cmp(userid, q) != 0) {
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write_dns(dns_fd, q, "BADIP", 5);
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return; /* illegal id */
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}
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memcpy(&(users[userid].q), q, sizeof(struct query));
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users[userid].last_pkt = time(NULL);
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} else if(in[0] == 'Z' || in[0] == 'z') {
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/* Check for case conservation and chars not allowed according to RFC */
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@ -264,14 +281,15 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
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return;
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}
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userid = in[1] & 0x7;
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userid = b32_8to5(in[1]);
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if (ip_cmp(userid, q) != 0) {
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write_dns(dns_fd, q, "BADIP", 5);
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return; /* illegal id */
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}
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codec = in[2] & 0xF;
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codec = b32_8to5(in[2]);
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switch (codec) {
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case 5: /* 5 bits per byte = base32 */
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enc = get_base32_encoder();
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@ -288,6 +306,25 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
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break;
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}
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return;
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} else if(in[0] == 'P' || in[0] == 'p') {
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int dn_seq;
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int dn_frag;
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read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), domain_len - 1, b32);
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/* Ping packet, store userid */
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userid = unpacked[0];
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if (userid < 0 || userid >= USERS || ip_cmp(userid, q) != 0) {
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write_dns(dns_fd, q, "BADIP", 5);
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return; /* illegal id */
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}
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dn_seq = unpacked[1] >> 4;
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dn_frag = unpacked[1] & 15;
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memcpy(&(users[userid].q), q, sizeof(struct query));
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users[userid].last_pkt = time(NULL);
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/* Update seqno and maybe send immediate response packet */
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update_downstream_seqno(dns_fd, userid, dn_seq, dn_frag);
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} else if((in[0] >= '0' && in[0] <= '9')
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|| (in[0] >= 'a' && in[0] <= 'f')
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|| (in[0] >= 'A' && in[0] <= 'F')) {
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@ -298,7 +335,7 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
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if ((in[0] >= 'A' && in[0] <= 'F'))
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code = in[0] - 'A' + 10;
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userid = code >> 1;
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userid = code;
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if (userid < 0 || userid >= USERS) {
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write_dns(dns_fd, q, "BADIP", 5);
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return; /* illegal id */
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@ -308,21 +345,46 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
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if (check_ip && ip_cmp(userid, q) != 0) {
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write_dns(dns_fd, q, "BADIP", 5);
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} else {
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/* decode with this users encoding */
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read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), domain_len - 1,
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users[userid].encoder);
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/* Decode data header */
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int up_seq = (b32_8to5(in[1]) >> 2) & 7;
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int up_frag = ((b32_8to5(in[1]) & 3) << 2) | ((b32_8to5(in[2]) >> 3) & 3);
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int dn_seq = (b32_8to5(in[2]) & 7);
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int dn_frag = b32_8to5(in[3]) >> 1;
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int lastfrag = b32_8to5(in[3]) & 1;
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/* Update query and time info for user */
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users[userid].last_pkt = time(NULL);
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memcpy(&(users[userid].q), q, sizeof(struct query));
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if (up_seq != users[userid].inpacket.seqno) {
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/* New packet has arrived */
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users[userid].inpacket.seqno = up_seq;
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users[userid].inpacket.len = 0;
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users[userid].inpacket.offset = 0;
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}
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users[userid].inpacket.fragment = up_frag;
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/* decode with this users encoding */
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read = unpack_data(unpacked, sizeof(unpacked), &(in[4]), domain_len - 4,
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users[userid].encoder);
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/* copy to packet buffer, update length */
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memcpy(users[userid].inpacket.data + users[userid].inpacket.offset, unpacked, read);
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users[userid].inpacket.len += read;
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users[userid].inpacket.offset += read;
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if (code & 1) {
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if (debug >= 1) {
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printf("IN pkt seq# %d, frag %d (last=%d), fragsize %d, total %d, from user %d\n",
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up_seq, up_frag, lastfrag, read, users[userid].inpacket.len, userid);
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}
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if (lastfrag & 1) { /* packet is complete */
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int ret;
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outlen = sizeof(out);
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uncompress((uint8_t*)out, &outlen,
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ret = uncompress((uint8_t*)out, &outlen,
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(uint8_t*)users[userid].inpacket.data, users[userid].inpacket.len);
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if (ret == Z_OK) {
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hdr = (struct ip*) (out + 4);
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touser = find_user_by_ip(hdr->ip_dst.s_addr);
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@ -337,16 +399,15 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
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users[touser].outpacket.len = users[userid].inpacket.len;
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}
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}
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} else {
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printf("Discarded data, uncompress() result: %d\n", ret);
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}
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users[userid].inpacket.len = users[userid].inpacket.offset = 0;
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}
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/* Update seqno and maybe send immediate response packet */
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update_downstream_seqno(dns_fd, userid, dn_seq, dn_frag);
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}
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}
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/* userid must be set for a reply to be sent */
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if (userid >= 0 && userid < USERS && ip_cmp(userid, q) == 0 && users[userid].outpacket.len > 0) {
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write_dns(dns_fd, q, users[userid].outpacket.data, users[userid].outpacket.len);
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users[userid].outpacket.len = 0;
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users[userid].q.id = 0;
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}
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}
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static void
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@ -361,7 +422,7 @@ handle_ns_request(int dns_fd, struct query *q)
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len = dns_encode_ns_response(buf, sizeof(buf), q, topdomain);
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if (debug >= 1) {
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if (debug >= 2) {
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struct sockaddr_in *tempin;
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tempin = (struct sockaddr_in *) &(q->from);
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printf("TX: client %s, type %d, name %s, %d bytes NS reply\n",
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@ -394,7 +455,7 @@ forward_query(int bind_fd, struct query *q)
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memcpy(&(myaddr->sin_addr), &newaddr, sizeof(in_addr_t));
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myaddr->sin_port = htons(bind_port);
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if (debug >= 1) {
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if (debug >= 2) {
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printf("TX: NS reply \n");
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}
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@ -422,18 +483,18 @@ tunnel_bind(int bind_fd, int dns_fd)
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id = dns_get_id(packet, r);
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if (debug >= 1) {
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if (debug >= 2) {
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printf("RX: Got response on query %u from DNS\n", (id & 0xFFFF));
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}
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/* Get sockaddr from id */
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fw_query_get(id, &query);
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if (!query && debug >= 1) {
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if (!query && debug >= 2) {
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printf("Lost sender of id %u, dropping reply\n", (id & 0xFFFF));
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return 0;
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}
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if (debug >= 1) {
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if (debug >= 2) {
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struct sockaddr_in *in;
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in = (struct sockaddr_in *) &(query->addr);
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printf("TX: client %s id %u, %d bytes\n",
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@ -460,7 +521,7 @@ tunnel_dns(int tun_fd, int dns_fd, int bind_fd)
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if ((read = read_dns(dns_fd, &q)) <= 0)
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return 0;
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if (debug >= 1) {
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if (debug >= 2) {
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struct sockaddr_in *tempin;
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tempin = (struct sockaddr_in *) &(q.from);
|
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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",
|
||||
|
|
|
|||
|
|
@ -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;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -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];
|
||||
|
|
|
|||
Loading…
Reference in New Issue