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More unsignedness and working DNS tunnelling

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This commit is contained in:
frekky 2015-08-29 20:08:46 +08:00
parent 51a59bed24
commit 98da57ba74
2 changed files with 226 additions and 403 deletions
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618
src/server.c
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@ -181,7 +181,8 @@ save_to_qmem_pingordata(int userid, struct query *q)
+ 1 char CMC; that last char is non-Base32. + 1 char CMC; that last char is non-Base32.
*/ */
char cmc[8]; warnx("save_to_qmem_pingordata deprecated! use something else instead!");
uint8_t cmc[8];
int i; int i;
if (q->name[0] == 'P' || q->name[0] == 'p') { if (q->name[0] == 'P' || q->name[0] == 'p') {
@ -195,15 +196,15 @@ save_to_qmem_pingordata(int userid, struct query *q)
/* We already unpacked in handle_null_request(), but that's /* We already unpacked in handle_null_request(), but that's
lost now... Note: b32 directly, we want no undotify here! */ lost now... Note: b32 directly, we want no undotify here! */
i = b32->decode(cmc, &cmcsize, q->name + 1, (cp - q->name) - 1); i = b32->decode(cmc, &cmcsize, (uint8_t *)q->name + 1, (cp - q->name) - 1);
if (i < 4) if (i < 4)
return; /* illegal ping; shouldn't happen */ return; /* illegal ping; shouldn't happen */
save_to_qmem(users[userid].qmemping_cmc, /*save_to_qmem(users[userid].qmemping_cmc,
users[userid].qmemping_type, QMEMPING_LEN, users[userid].qmemping_type, QMEMPING_LEN,
&users[userid].qmemping_lastfilled, &users[userid].qmemping_lastfilled,
(void *) cmc, q->type); (void *) cmc, q->type);*/
} else { } else {
/* Data packet, hopefully not illegal */ /* Data packet, hopefully not illegal */
if (strlen(q->name) < 5) if (strlen(q->name) < 5)
@ -220,10 +221,10 @@ save_to_qmem_pingordata(int userid, struct query *q)
else else
cmc[i] = q->name[i+1]; cmc[i] = q->name[i+1];
save_to_qmem(users[userid].qmemdata_cmc, /*save_to_qmem(users[userid].qmemdata_cmc,
users[userid].qmemdata_type, QMEMDATA_LEN, users[userid].qmemdata_type, QMEMDATA_LEN,
&users[userid].qmemdata_lastfilled, &users[userid].qmemdata_lastfilled,
(void *) cmc, q->type); (void *) cmc, q->type);*/
} }
} }
@ -231,7 +232,8 @@ static inline int
answer_from_qmem_data(int dns_fd, int userid, struct query *q) answer_from_qmem_data(int dns_fd, int userid, struct query *q)
/* Quick helper function to keep handle_null_request() clean */ /* Quick helper function to keep handle_null_request() clean */
{ {
char cmc[4]; warnx("answer_from_qmem_data deprecated! use something else");
/*char cmc[4];
int i; int i;
for (i = 0; i < 4; i++) for (i = 0; i < 4; i++)
@ -242,7 +244,8 @@ answer_from_qmem_data(int dns_fd, int userid, struct query *q)
return answer_from_qmem(dns_fd, q, users[userid].qmemdata_cmc, return answer_from_qmem(dns_fd, q, users[userid].qmemdata_cmc,
users[userid].qmemdata_type, QMEMDATA_LEN, users[userid].qmemdata_type, QMEMDATA_LEN,
(void *) cmc); (void *) cmc);*/
return 0;
} }
/* END INLINE FUNCTION DEFINITIONS */ /* END INLINE FUNCTION DEFINITIONS */
@ -260,7 +263,7 @@ answer_from_qmem_data(int dns_fd, int userid, struct query *q)
are prevented. Data-CMC is only 36 counts, so our cache length should are prevented. Data-CMC is only 36 counts, so our cache length should
not exceed 36/2=18 packets. (This quick rule assumes all packets are not exceed 36/2=18 packets. (This quick rule assumes all packets are
otherwise equal, which they arent: up/downstream seq, TCP/IP headers and otherwise equal, which they arent: up/downstream seq, TCP/IP headers and
the actual data) TODO: adjust dns cache length the actual data
*/ */
static void static void
@ -370,40 +373,8 @@ forward_query(int bind_fd, struct query *q)
} }
} }
void
send_ping_response(int dns_fd, int userid, struct query *q)
{
static uint8_t pkt[10];
size_t datalen = 5;
/* Build downstream data + ping header (see doc/proto_xxxxxxxx.txt) for details */
pkt[0] = users[userid].outgoing->start_seq_id & 0xFF;
pkt[1] = users[userid].incoming->start_seq_id & 0xFF;
pkt[2] = (1 << 5); /* ping flag */
pkt[3] = users[userid].outgoing->windowsize & 0xFF;
pkt[4] = users[userid].incoming->windowsize & 0xFF;
write_dns(dns_fd, q, (char *)pkt, datalen, users[userid].downenc);
if (q->id2 != 0) { /* rotate pending duplicate queries */
q->id = q->id2;
q->fromlen = q->fromlen2;
memcpy(&(q->from), &(q->from2), q->fromlen2);
if (debug >= 1)
warnx("OUT again to last duplicate");
write_dns(dns_fd, q, (char *)pkt, datalen, users[userid].downenc);
}
save_to_qmem_pingordata(userid, q);
#ifdef DNSCACHE_LEN
save_to_dnscache(userid, q, (char *)pkt, datalen + 2);
#endif
q->id = 0; /* this query is used */
}
static int static int
send_frag_or_dataless(int dns_fd, int userid, struct query *q) send_frag_or_dataless(int dns_fd, int userid, struct query *q, int ping)
/* Sends current fragment to user, or a ping if no data available. /* Sends current fragment to user, or a ping if no data available.
Does not update anything, except: Does not update anything, except:
- discards q always (query is used) - discards q always (query is used)
@ -413,55 +384,57 @@ send_frag_or_dataless(int dns_fd, int userid, struct query *q)
0 = don't call us again for now. 0 = don't call us again for now.
*/ */
{ {
static uint8_t pkt[MAX_FRAGSIZE + DOWNSTREAM_HDR]; static uint8_t pkt[MAX_FRAGSIZE + DOWNSTREAM_PING_HDR];
int ping = 0; size_t datalen, headerlen;
size_t datalen;
fragment *f; fragment *f;
struct frag_buffer *out; struct frag_buffer *out, *in;
in = users[userid].incoming;
out = users[userid].outgoing; out = users[userid].outgoing;
f = window_get_next_sending_fragment(out, users[userid].next_upstream_ack); f = window_get_next_sending_fragment(out, &users[userid].next_upstream_ack);
if (!f && user_sending(userid)) { if (!f) {
/* Need to tell client to sync stuff - send data header with ping stuff */ /* No data, may as well send data/ping header (with extra info) */
ping = 1; ping = 1;
} /* TODO: If re-sent too many times, drop stuff */ datalen = 0;
pkt[0] = 0; /* Pings don't need seq IDs unless they have data */
/* Build downstream data header (see doc/proto_xxxxxxxx.txt) for details */ pkt[1] = users[userid].next_upstream_ack & 0xFF;
pkt[0] = f->seqID & 0xFF; pkt[2] = (1 << 5) | ((users[userid].next_upstream_ack < 0 ? 0 : 1) << 3);
pkt[1] = f->ack_other & 0xFF; /* TODO: resend ACKs in pings? */
pkt[2] = ((ping & 1) << 5) | ((f->compressed & 1) << 4) | ((f->ack_other < 0 ? 0 : 1) << 3) users[userid].next_upstream_ack = -1;
| (f->is_nack << 2) | (f->start << 1) | f->end;
if (ping) {
pkt[3] = out->windowsize & 0xFF;
pkt[4] = users[userid].incoming->windowsize & 0xFF;
datalen = 5;
} else { } else {
datalen = DOWNSTREAM_HDR + f->len; datalen = f->len;
if (datalen > sizeof(pkt)) { pkt[0] = f->seqID & 0xFF;
warnx("send_frag_or_dataless: fragment too large to send!"); pkt[1] = f->ack_other & 0xFF;
return 0; pkt[2] = ((f->compressed & 1) << 4) | ((f->ack_other < 0 ? 0 : 1) << 3) |
} (f->is_nack << 2) | (f->start << 1) | f->end;
memcpy(&pkt, f->data, f->len); headerlen = DOWNSTREAM_HDR;
}
write_dns(dns_fd, q, (char *)pkt, datalen, users[userid].downenc);
if (q->id2 != 0) { /* reply to any duplicates */
q->id = q->id2;
q->fromlen = q->fromlen2;
memcpy(&(q->from), &(q->from2), q->fromlen2);
if (debug >= 1)
warnx("OUT again to last duplicate");
write_dns(dns_fd, q, (char *)pkt, datalen, users[userid].downenc);
} }
save_to_qmem_pingordata(userid, q); /* Build downstream data/ping header (see doc/proto_xxxxxxxx.txt) for details */
if (ping) { /* TODO: pings with downstream data */
pkt[3] = out->windowsize & 0xFF;
pkt[4] = in->windowsize & 0xFF;
pkt[5] = out->start_seq_id & 0xFF;
pkt[6] = in->start_seq_id & 0xFF;
headerlen = DOWNSTREAM_PING_HDR;
}
if (datalen + headerlen > sizeof(pkt)) {
warnx("send_frag_or_dataless: fragment too large to send! (%lu)", datalen);
return 0;
}
if (f) memcpy(pkt + headerlen, f->data, datalen);
write_dns(dns_fd, q, (char *)pkt, datalen + headerlen, users[userid].downenc);
/* TODO: reply to any duplicates (q.id2 etc) */
// save_to_qmem_pingordata(userid, q);
#ifdef DNSCACHE_LEN #ifdef DNSCACHE_LEN
save_to_dnscache(userid, q, (char *)pkt, datalen + 2); save_to_dnscache(userid, q, (char *)pkt, datalen + 2);
#endif #endif
/* this query has been */ /* this query has been used */
q->id = 0; q->id = 0;
window_tick(out); window_tick(out);
@ -569,14 +542,8 @@ tunnel_tun(int tun_fd, struct dnsfd *dns_fds)
window_add_outgoing_data(users[userid].outgoing, out, outlen, 1); window_add_outgoing_data(users[userid].outgoing, out, outlen, 1);
/* Start sending immediately if query is waiting */ /* TODO: Start sending immediately if query is waiting
if (users[userid].q_sendrealsoon.id != 0) { * Need to get incoming query handling done first. */
int dns_fd = get_dns_fd(dns_fds, &users[userid].q_sendrealsoon.from);
send_frag_or_dataless(dns_fd, userid, &users[userid].q_sendrealsoon);
} else if (users[userid].q.id != 0) {
int dns_fd = get_dns_fd(dns_fds, &users[userid].q.from);
send_frag_or_dataless(dns_fd, userid, &users[userid].q);
}
return outlen; return outlen;
} else { /* CONN_RAW_UDP */ } else { /* CONN_RAW_UDP */
@ -598,8 +565,8 @@ tunnel_dns(int tun_fd, int dns_fd, struct dnsfd *dns_fds, int bind_fd)
return 0; return 0;
if (debug >= 2) { if (debug >= 2) {
fprintf(stderr, "RX: client %s, type %d, name %s\n", fprintf(stderr, "RX: client %s ID %5d, type %d, name %s\n",
format_addr(&q.from, q.fromlen), q.type, q.name); format_addr(&q.from, q.fromlen), q.id, q.type, q.name);
} }
domain_len = strlen(q.name) - strlen(topdomain); domain_len = strlen(q.name) - strlen(topdomain);
@ -653,7 +620,7 @@ tunnel_dns(int tun_fd, int dns_fd, struct dnsfd *dns_fds, int bind_fd)
} else { } else {
/* Forward query to other port ? */ /* Forward query to other port ? */
if (debug >= 3) { if (debug >= 3) {
fprintf(stderr, "Requested domain outside our topdomain."); fprintf(stderr, "Requested domain outside our topdomain.\n");
} }
if (bind_fd) { if (bind_fd) {
forward_query(bind_fd, &q); forward_query(bind_fd, &q);
@ -673,26 +640,9 @@ server_tunnel(int tun_fd, struct dnsfd *dns_fds, int bind_fd, int max_idle_time)
while (running) { while (running) {
int maxfd; int maxfd;
tv.tv_sec = 10; /* doesn't really matter */ tv.tv_sec = 5; /* TODO: adjust time based on query timeouts (lazy mode) */
tv.tv_usec = 0; tv.tv_usec = 0;
/* Adjust timeout if there is anything to send realsoon.
Clients won't be sending new data until we send our ack, TODO: adjust stuff in this function
so don't keep them waiting long. This only triggers at
final upstream fragments, which is about once per eight
requests during heavy upstream traffic.
20msec: ~8 packets every 1/50sec = ~400 DNSreq/sec,
or ~1200bytes every 1/50sec = ~0.5 Mbit/sec upstream */
for (userid = 0; userid < created_users; userid++) {
if (user_active(userid)) {
users[userid].q_sendrealsoon_new = 0;
if (users[userid].q_sendrealsoon.id != 0) {
tv.tv_sec = 0;
tv.tv_usec = 20000;
}
}
}
FD_ZERO(&fds); FD_ZERO(&fds);
maxfd = 0; maxfd = 0;
@ -754,14 +704,6 @@ server_tunnel(int tun_fd, struct dnsfd *dns_fds, int bind_fd, int max_idle_time)
tunnel_bind(bind_fd, dns_fds); tunnel_bind(bind_fd, dns_fds);
} }
} }
/* Send realsoon's if tun or dns didn't already */
for (userid = 0; userid < created_users; userid++)
if (user_active(userid) && users[userid].q_sendrealsoon.id != 0 &&
users[userid].conn == CONN_DNS_NULL && !users[userid].q_sendrealsoon_new) {
int dns_fd = get_dns_fd(dns_fds, &users[userid].q_sendrealsoon.from);
send_frag_or_dataless(dns_fd, userid, &users[userid].q_sendrealsoon);
}
} }
return 0; return 0;
@ -770,36 +712,25 @@ server_tunnel(int tun_fd, struct dnsfd *dns_fds, int bind_fd, int max_idle_time)
void void
handle_full_packet(int tun_fd, struct dnsfd *dns_fds, int userid, uint8_t *data, size_t len) handle_full_packet(int tun_fd, struct dnsfd *dns_fds, int userid, uint8_t *data, size_t len)
{ {
unsigned long outlen; size_t outlen;
uint8_t out[64*1024]; uint8_t out[64*1024];
struct ip *hdr;
int touser; int touser;
int ret; int ret; // TODO: optional upstream compression flag
outlen = sizeof(out); outlen = sizeof(out);
if ((ret = uncompress(out, &outlen, data, len)) == Z_OK) { if ((ret = uncompress(out, &outlen, data, len)) == Z_OK) {
struct ip *hdr;
hdr = (struct ip*) (out + 4); hdr = (struct ip*) (out + 4);
touser = find_user_by_ip(hdr->ip_dst.s_addr); touser = find_user_by_ip(hdr->ip_dst.s_addr);
if (debug >= 3)
fprintf(stderr, "FULL PKT: %lu bytes from user %d (touser %d)\n", len, userid, touser);
if (touser == -1) { if (touser == -1) {
/* send the uncompressed packet to tun device */ /* send the uncompressed packet to tun device */
write_tun(tun_fd, out, outlen); write_tun(tun_fd, out, outlen);
} else { } else {
/* send the compressed(!) packet to other client */ /* send the compressed (!) packet to other client */
if (users[touser].conn == CONN_DNS_NULL) { if (users[touser].conn == CONN_DNS_NULL) {
if (window_buffer_available(users[touser].outgoing) * users[touser].outgoing->maxfraglen >= len) { window_add_outgoing_data(users[touser].outgoing, data, len, 1);
window_add_outgoing_data(users[touser].outgoing, data, len, 1); /* TODO: send immediately if query waiting */
/* Start sending immediately if query is waiting */
if (users[touser].q_sendrealsoon.id != 0) {
int dns_fd = get_dns_fd(dns_fds, &users[touser].q_sendrealsoon.from);
send_frag_or_dataless(dns_fd, touser, &users[touser].q_sendrealsoon);
} else if (users[touser].q.id != 0) {
int dns_fd = get_dns_fd(dns_fds, &users[touser].q.from);
send_frag_or_dataless(dns_fd, touser, &users[touser].q);
}
}
} else{ /* CONN_RAW_UDP */ } else{ /* CONN_RAW_UDP */
int dns_fd = get_dns_fd(dns_fds, &users[touser].q.from); int dns_fd = get_dns_fd(dns_fds, &users[touser].q.from);
send_raw(dns_fd, data, len, touser, RAW_HDR_CMD_DATA, &users[touser].q); send_raw(dns_fd, data, len, touser, RAW_HDR_CMD_DATA, &users[touser].q);
@ -1002,13 +933,13 @@ read_dns(int fd, struct dnsfd *dns_fds, int tun_fd, struct query *q)
} }
static size_t static size_t
write_dns_nameenc(char *buf, size_t buflen, char *data, int datalen, char downenc) write_dns_nameenc(uint8_t *buf, size_t buflen, uint8_t *data, size_t datalen, char downenc)
/* Returns #bytes of data that were encoded */ /* Returns #bytes of data that were encoded */
{ {
static int td1 = 0; static int td1 = 0;
static int td2 = 0; static int td2 = 0;
size_t space; size_t space;
char *b; uint8_t *b;
/* Make a rotating topdomain to prevent filtering */ /* Make a rotating topdomain to prevent filtering */
td1+=3; td1+=3;
@ -1057,7 +988,7 @@ write_dns_nameenc(char *buf, size_t buflen, char *data, int datalen, char downen
/* Add dot (if it wasn't there already) and topdomain */ /* Add dot (if it wasn't there already) and topdomain */
b = buf; b = buf;
b += strlen(buf) - 1; b += strlen((char *)buf) - 1;
if (*b != '.') if (*b != '.')
*++b = '.'; *++b = '.';
b++; b++;
@ -1072,7 +1003,7 @@ write_dns_nameenc(char *buf, size_t buflen, char *data, int datalen, char downen
} }
void void
write_dns(int fd, struct query *q, char *data, int datalen, char downenc) write_dns(int fd, struct query *q, char *data, size_t datalen, char downenc)
{ {
char buf[64*1024]; char buf[64*1024];
int len = 0; int len = 0;
@ -1080,11 +1011,9 @@ write_dns(int fd, struct query *q, char *data, int datalen, char downenc)
if (q->type == T_CNAME || q->type == T_A) { if (q->type == T_CNAME || q->type == T_A) {
char cnamebuf[1024]; /* max 255 */ char cnamebuf[1024]; /* max 255 */
write_dns_nameenc(cnamebuf, sizeof(cnamebuf), write_dns_nameenc((uint8_t *)cnamebuf, sizeof(cnamebuf), (uint8_t *)data, datalen, downenc);
data, datalen, downenc);
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, cnamebuf, len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, cnamebuf, sizeof(cnamebuf));
sizeof(cnamebuf));
} else if (q->type == T_MX || q->type == T_SRV) { } else if (q->type == T_MX || q->type == T_SRV) {
char mxbuf[64*1024]; char mxbuf[64*1024];
char *b = mxbuf; char *b = mxbuf;
@ -1092,9 +1021,8 @@ write_dns(int fd, struct query *q, char *data, int datalen, char downenc)
int res; int res;
while (1) { while (1) {
res = write_dns_nameenc(b, sizeof(mxbuf) - (b - mxbuf), res = write_dns_nameenc((uint8_t *)b, sizeof(mxbuf) - (b - mxbuf),
data + offset, (uint8_t *)data + offset, datalen - offset, downenc);
datalen - offset, downenc);
if (res < 1) { if (res < 1) {
/* nothing encoded */ /* nothing encoded */
b++; /* for final \0 */ b++; /* for final \0 */
@ -1115,22 +1043,22 @@ write_dns(int fd, struct query *q, char *data, int datalen, char downenc)
sizeof(mxbuf)); sizeof(mxbuf));
} else if (q->type == T_TXT) { } else if (q->type == T_TXT) {
/* TXT with base32 */ /* TXT with base32 */
char txtbuf[64*1024]; uint8_t txtbuf[64*1024];
size_t space = sizeof(txtbuf) - 1;; size_t space = sizeof(txtbuf) - 1;;
memset(txtbuf, 0, sizeof(txtbuf)); memset(txtbuf, 0, sizeof(txtbuf));
if (downenc == 'S') { if (downenc == 'S') {
txtbuf[0] = 's'; /* plain base64(Sixty-four) */ txtbuf[0] = 's'; /* plain base64(Sixty-four) */
len = b64->encode(txtbuf+1, &space, data, datalen); len = b64->encode(txtbuf+1, &space, (uint8_t *)data, datalen);
} }
else if (downenc == 'U') { else if (downenc == 'U') {
txtbuf[0] = 'u'; /* Base64 with Underscore */ txtbuf[0] = 'u'; /* Base64 with Underscore */
len = b64u->encode(txtbuf+1, &space, data, datalen); len = b64u->encode(txtbuf+1, &space, (uint8_t *)data, datalen);
} }
else if (downenc == 'V') { else if (downenc == 'V') {
txtbuf[0] = 'v'; /* Base128 */ txtbuf[0] = 'v'; /* Base128 */
len = b128->encode(txtbuf+1, &space, data, datalen); len = b128->encode(txtbuf+1, &space, (uint8_t *)data, datalen);
} }
else if (downenc == 'R') { else if (downenc == 'R') {
txtbuf[0] = 'r'; /* Raw binary data */ txtbuf[0] = 'r'; /* Raw binary data */
@ -1138,9 +1066,9 @@ write_dns(int fd, struct query *q, char *data, int datalen, char downenc)
memcpy(txtbuf + 1, data, len); memcpy(txtbuf + 1, data, len);
} else { } else {
txtbuf[0] = 't'; /* plain base32(Thirty-two) */ txtbuf[0] = 't'; /* plain base32(Thirty-two) */
len = b32->encode(txtbuf+1, &space, data, datalen); len = b32->encode(txtbuf+1, &space, (uint8_t *)data, datalen);
} }
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, txtbuf, len+1); len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, (char *)txtbuf, len+1);
} else { } else {
/* Normal NULL-record encode */ /* Normal NULL-record encode */
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, data, datalen); len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, data, datalen);
@ -1152,22 +1080,47 @@ write_dns(int fd, struct query *q, char *data, int datalen, char downenc)
} }
if (debug >= 2) { if (debug >= 2) {
fprintf(stderr, "TX: client %s, type %d, name %s, %d bytes data\n", fprintf(stderr, "TX: client %s ID %5d, %lu bytes data, type %d, name '%10s'\n",
format_addr(&q->from, q->fromlen), q->type, q->name, datalen); format_addr(&q->from, q->fromlen), q->id, datalen, q->type, q->name);
} }
sendto(fd, buf, len, 0, (struct sockaddr*)&q->from, q->fromlen); sendto(fd, buf, len, 0, (struct sockaddr*)&q->from, q->fromlen);
} }
void
send_data_or_ping_response(int tun_fd, int dns_fd, struct dnsfd *dns_fds, int userid, struct query *q, int ping) {
uint8_t unpacked[64*1024];
size_t read;
/* if waiting for an ACK to be sent back upstream (on incoming buffer) */
if (users[userid].next_upstream_ack < 0) {
users[userid].next_upstream_ack = window_get_next_ack(users[userid].incoming);
}
window_tick(users[userid].outgoing);
read = window_reassemble_data(users[userid].incoming, unpacked, sizeof(unpacked), NULL);
window_tick(users[userid].incoming);
if (read > 0) { /* Data reassembled successfully + cleared out of buffer */
handle_full_packet(tun_fd, dns_fds, userid, unpacked, read);
}
send_frag_or_dataless(dns_fd, userid, q, ping);
/* Save new query and time info */
memcpy(&(users[userid].q), q, sizeof(struct query));
users[userid].last_pkt = time(NULL);
}
void void
handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query *q, int domain_len) handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query *q, int domain_len)
/* Handles a NULL DNS request. See doc/proto_XXXXXXXX.txt for details on iodine protocol. */ /* Handles a NULL DNS request. See doc/proto_XXXXXXXX.txt for details on iodine protocol. */
{ {
struct in_addr tempip; struct in_addr tempip;
char in[512]; uint8_t in[512];
char logindata[16]; char logindata[16];
char out[64*1024]; uint8_t out[64*1024];
static char unpacked[64*1024]; static uint8_t unpacked[64*1024];
char *tmp[2]; char *tmp[2];
int userid; int userid;
size_t read; size_t read;
@ -1202,45 +1155,47 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
userid = find_available_user(); userid = find_available_user();
if (userid >= 0) { if (userid >= 0) {
int i; int i;
struct tun_user *u = &users[userid];
users[userid].seed = rand(); u->seed = rand();
/* Store remote IP number */ /* Store remote IP number */
memcpy(&(users[userid].host), &(q->from), q->fromlen); memcpy(&(u->host), &(q->from), q->fromlen);
users[userid].hostlen = q->fromlen; u->hostlen = q->fromlen;
memcpy(&(users[userid].q), q, sizeof(struct query)); memcpy(&(u->q), q, sizeof(struct query));
users[userid].encoder = get_base32_encoder(); u->encoder = get_base32_encoder();
users[userid].downenc = 'T'; u->downenc = 'T';
send_version_response(dns_fd, VERSION_ACK, users[userid].seed, userid, q); u->downenc_bits = 5;
send_version_response(dns_fd, VERSION_ACK, u->seed, userid, q);
syslog(LOG_INFO, "accepted version for user #%d from %s", syslog(LOG_INFO, "accepted version for user #%d from %s",
userid, format_addr(&q->from, q->fromlen)); userid, format_addr(&q->from, q->fromlen));
users[userid].q.id = 0; u->q.id = 0;
users[userid].q.id2 = 0; u->q.id2 = 0;
users[userid].q_sendrealsoon.id = 0; u->fragsize = 100; /* very safe */
users[userid].q_sendrealsoon.id2 = 0; u->conn = CONN_DNS_NULL;
users[userid].q_sendrealsoon_new = 0; u->lazy = 0;
users[userid].fragsize = 100; /* very safe */
users[userid].conn = CONN_DNS_NULL;
users[userid].lazy = 0;
// TODO: client specified window size // TODO: client specified window size
users[userid].incoming = window_buffer_init(128, 10, MAX_FRAGSIZE, WINDOW_RECVING); u->incoming = window_buffer_init(INFRAGBUF_LEN, 10, MAX_FRAGSIZE, WINDOW_RECVING);
users[userid].outgoing = window_buffer_init(16, 10, users[userid].fragsize, WINDOW_SENDING); u->outgoing = window_buffer_init(OUTFRAGBUF_LEN, 10,
users[userid].next_upstream_ack = -1; u->encoder->get_raw_length(u->fragsize) - DOWNSTREAM_PING_HDR, WINDOW_SENDING);
u->next_upstream_ack = -1;
#ifdef DNSCACHE_LEN #ifdef DNSCACHE_LEN
{ {
for (i = 0; i < DNSCACHE_LEN; i++) { for (i = 0; i < DNSCACHE_LEN; i++) {
users[userid].dnscache_q[i].id = 0; u->dnscache_q[i].id = 0;
users[userid].dnscache_answerlen[i] = 0; u->dnscache_answerlen[i] = 0;
} }
} }
users[userid].dnscache_lastfilled = 0; u->dnscache_lastfilled = 0;
#endif #endif
for (i = 0; i < QMEMPING_LEN; i++) /*for (i = 0; i < QMEMPING_LEN; i++)
users[userid].qmemping_type[i] = T_UNSET; u->qmemping_type[i] = T_UNSET;
users[userid].qmemping_lastfilled = 0; u->qmemping_lastfilled = 0;
for (i = 0; i < QMEMDATA_LEN; i++) for (i = 0; i < QMEMDATA_LEN; i++)
users[userid].qmemdata_type[i] = T_UNSET; u->qmemdata_type[i] = T_UNSET;
users[userid].qmemdata_lastfilled = 0; u->qmemdata_lastfilled = 0;*/
if (debug >= 1)
fprintf(stderr, "User %d connected with correct version from %s.\n",
userid, format_addr(&q->from, q->fromlen));
} else { } else {
/* No space for another user */ /* No space for another user */
send_version_response(dns_fd, VERSION_FULL, created_users, 0, q); send_version_response(dns_fd, VERSION_FULL, created_users, 0, q);
@ -1262,11 +1217,13 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
/* Login phase, handle auth */ /* Login phase, handle auth */
userid = unpacked[0]; userid = unpacked[0];
if (debug >= 3)
fprintf(stderr, "Received login request for user %d from %s.\n",
userid, format_addr(&q->from, q->fromlen));
if (check_user_and_ip(userid, q) != 0) { if (check_user_and_ip(userid, q) != 0) {
write_dns(dns_fd, q, "BADIP", 5, 'T'); write_dns(dns_fd, q, "BADIP", 5, 'T');
syslog(LOG_WARNING, "dropped login request from user #%d from unexpected source %s", syslog(LOG_WARNING, "dropped login request from user #%d from %s; expected source %s",
userid, format_addr(&q->from, q->fromlen)); userid, format_addr(&q->from, q->fromlen), format_addr(&users[userid].host, users[userid].hostlen));
return; return;
} else { } else {
users[userid].last_pkt = time(NULL); users[userid].last_pkt = time(NULL);
@ -1282,10 +1239,10 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
tempip.s_addr = users[userid].tun_ip; tempip.s_addr = users[userid].tun_ip;
tmp[1] = strdup(inet_ntoa(tempip)); tmp[1] = strdup(inet_ntoa(tempip));
read = snprintf(out, sizeof(out), "%s-%s-%d-%d", read = snprintf((char *)out, sizeof(out), "%s-%s-%d-%d",
tmp[0], tmp[1], my_mtu, netmask); tmp[0], tmp[1], my_mtu, netmask);
write_dns(dns_fd, q, out, read, users[userid].downenc); write_dns(dns_fd, q, (char *)out, read, users[userid].downenc);
q->id = 0; q->id = 0;
syslog(LOG_NOTICE, "accepted password from user #%d, given IP %s", userid, tmp[1]); syslog(LOG_NOTICE, "accepted password from user #%d, given IP %s", userid, tmp[1]);
@ -1331,7 +1288,7 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
/* Reply with received hostname as data */ /* Reply with received hostname as data */
/* No userid here, reply with lowest-grade downenc */ /* No userid here, reply with lowest-grade downenc */
write_dns(dns_fd, q, in, domain_len, 'T'); write_dns(dns_fd, q, (char *)in, domain_len, 'T');
return; return;
} else if(in[0] == 'S' || in[0] == 's') { /* Switch upstream codec */ } else if(in[0] == 'S' || in[0] == 's') { /* Switch upstream codec */
int codec; int codec;
@ -1389,31 +1346,37 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
return; /* illegal id */ return; /* illegal id */
} }
int bits = 0;
switch (in[2]) { switch (in[2]) {
case 'T': case 'T':
case 't': case 't':
users[userid].downenc = 'T'; users[userid].downenc = 'T';
write_dns(dns_fd, q, "Base32", 6, users[userid].downenc); write_dns(dns_fd, q, "Base32", 6, users[userid].downenc);
bits = 5;
break; break;
case 'S': case 'S':
case 's': case 's':
users[userid].downenc = 'S'; users[userid].downenc = 'S';
write_dns(dns_fd, q, "Base64", 6, users[userid].downenc); write_dns(dns_fd, q, "Base64", 6, users[userid].downenc);
bits = 6;
break; break;
case 'U': case 'U':
case 'u': case 'u':
users[userid].downenc = 'U'; users[userid].downenc = 'U';
write_dns(dns_fd, q, "Base64u", 7, users[userid].downenc); write_dns(dns_fd, q, "Base64u", 7, users[userid].downenc);
bits = 6;
break; break;
case 'V': case 'V':
case 'v': case 'v':
users[userid].downenc = 'V'; users[userid].downenc = 'V';
write_dns(dns_fd, q, "Base128", 7, users[userid].downenc); write_dns(dns_fd, q, "Base128", 7, users[userid].downenc);
bits = 7;
break; break;
case 'R': case 'R':
case 'r': case 'r':
users[userid].downenc = 'R'; users[userid].downenc = 'R';
write_dns(dns_fd, q, "Raw", 3, users[userid].downenc); write_dns(dns_fd, q, "Raw", 3, users[userid].downenc);
bits = 8;
break; break;
case 'L': case 'L':
case 'l': case 'l':
@ -1429,6 +1392,14 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
write_dns(dns_fd, q, "BADCODEC", 8, users[userid].downenc); write_dns(dns_fd, q, "BADCODEC", 8, users[userid].downenc);
break; break;
} }
if (bits) {
int f = users[userid].fragsize;
users[userid].outgoing->maxfraglen = (bits * f) / 8 - DOWNSTREAM_PING_HDR;
if (debug >= 1)
warnx("Setting max downstream data length to %u bytes for user %d; bits %d (%c)",
users[userid].outgoing->maxfraglen, userid, bits, users[userid].downenc);
users[userid].downenc_bits = bits;
}
return; return;
} else if(in[0] == 'Y' || in[0] == 'y') { /* Downstream codec check */ } else if(in[0] == 'Y' || in[0] == 'y') { /* Downstream codec check */
int i; int i;
@ -1561,12 +1532,17 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
write_dns(dns_fd, q, "BADFRAG", 7, users[userid].downenc); write_dns(dns_fd, q, "BADFRAG", 7, users[userid].downenc);
} else { } else {
users[userid].fragsize = max_frag_size; users[userid].fragsize = max_frag_size;
write_dns(dns_fd, q, &unpacked[1], 2, users[userid].downenc); users[userid].outgoing->maxfraglen = (users[userid].downenc_bits * max_frag_size) /
8 - DOWNSTREAM_PING_HDR;
write_dns(dns_fd, q, (char *) unpacked + 1, 2, users[userid].downenc);
if (debug >= 1)
warnx("Setting max downstream data length to %u bytes for user %d; bits %d (%c)",
users[userid].outgoing->maxfraglen, userid, users[userid].downenc_bits, users[userid].downenc);
} }
return; return;
} else if(in[0] == 'P' || in[0] == 'p') { /* Ping request */ } else if(in[0] == 'P' || in[0] == 'p') { /* Ping request */
int dn_seq, up_seq, dn_wins, up_wins; int dn_seq, up_seq, dn_wins, up_wins, dn_ack;
int didsend = 0;
int respond; int respond;
/* We can't handle id=0, that's "no packet" to us. So drop /* We can't handle id=0, that's "no packet" to us. So drop
@ -1579,8 +1555,10 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
return; return;
read = unpack_data(unpacked, sizeof(unpacked), in + 1, domain_len - 1, b32); read = unpack_data(unpacked, sizeof(unpacked), in + 1, domain_len - 1, b32);
if (read < 7) if (read < UPSTREAM_PING) {
if (debug >= 1) warnx("Invalid ping! Length %lu", read);
return; return;
}
/* Ping packet, store userid */ /* Ping packet, store userid */
userid = unpacked[0]; userid = unpacked[0];
@ -1594,100 +1572,35 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
if (answer_from_dnscache(dns_fd, userid, q)) if (answer_from_dnscache(dns_fd, userid, q))
return; return;
#endif #endif
/* TODO: incoming query handling for lazy mode */
/* Check if duplicate (and not in full dnscache any more) */ /* Check if duplicate (and not in full dnscache any more) * /
if (answer_from_qmem(dns_fd, q, users[userid].qmemping_cmc, if (answer_from_qmem(dns_fd, q, users[userid].qmemping_cmc,
users[userid].qmemping_type, QMEMPING_LEN, users[userid].qmemping_type, QMEMPING_LEN,
(void *) unpacked)) (void *) unpacked))
return; return; */
/* Check if duplicate of waiting queries; impatient DNS relays dn_ack = ((unpacked[6] >> 2) & 1) ? unpacked[1] : -1;
like to re-try early and often (with _different_ .id!) */ up_wins = unpacked[2];
if (users[userid].q.id != 0 && dn_wins = unpacked[3];
q->type == users[userid].q.type && dn_seq = unpacked[4];
!strcmp(q->name, users[userid].q.name) && up_seq = unpacked[5];
users[userid].lazy) { respond = unpacked[6] & 1;
/* We have this ping already, and it's waiting to be
answered. Always keep the last duplicate, since the /* TODO: Use ping to re-sync window buffer */
relay may have forgotten its first version already. if (debug >= 2) {
Our answer will go to both. fprintf(stderr, "PING pkt from user %d, down %d/%d, up %d/%d, ACK %d\n", userid, dn_seq, dn_wins, up_seq, up_wins, dn_ack);
(If we already sent an answer, qmem/cache will
have triggered.) */
if (debug >= 2) {
fprintf(stderr, "PING pkt from user %d = dupe from impatient DNS server, remembering\n",
userid);
}
users[userid].q.id2 = q->id;
users[userid].q.fromlen2 = q->fromlen;
memcpy(&(users[userid].q.from2), &(q->from), q->fromlen);
return;
} }
if (users[userid].q_sendrealsoon.id != 0 && window_ack(users[userid].outgoing, dn_ack);
q->type == users[userid].q_sendrealsoon.type &&
!strcmp(q->name, users[userid].q_sendrealsoon.name)) {
/* Outer select loop will send answer immediately,
to both queries. */
if (debug >= 2) {
fprintf(stderr, "PING pkt from user %d = dupe from impatient DNS server, remembering\n",
userid);
}
users[userid].q_sendrealsoon.id2 = q->id;
users[userid].q_sendrealsoon.fromlen2 = q->fromlen;
memcpy(&(users[userid].q_sendrealsoon.from2),
&(q->from), q->fromlen);
return;
}
dn_seq = unpacked[1]; send_data_or_ping_response(tun_fd, dns_fd, dns_fds, userid, q, respond);
up_seq = unpacked[2];
up_wins = unpacked[3];
dn_wins = unpacked[4];
respond = unpacked[5] & 1;
if (debug >= 1) {
fprintf(stderr, "PING pkt from user %d, down %d/%d, up %d/%d\n", userid, dn_seq, dn_wins, up_seq, up_wins);
}
/* If there is a query that must be returned real soon, do it.
May contain new downstream data if the ping had a new ack. TODO: ping with downstream data
Otherwise, may also be re-sending old data. */
if (users[userid].q_sendrealsoon.id != 0) {
if (respond) send_ping_response(dns_fd, userid, &users[userid].q_sendrealsoon);
else send_frag_or_dataless(dns_fd, userid, &users[userid].q_sendrealsoon);
}
/* We need to store a new query, so if there still is an
earlier query waiting, always send a reply to finish it.
May contain new downstream data if the ping had a new ack.
Otherwise, may also be re-sending old data.
(This is duplicate data if we had q_sendrealsoon above.) */
if (users[userid].q.id != 0) {
didsend = 1;
if (respond)
send_ping_response(dns_fd, userid, &users[userid].q);
else
if (send_frag_or_dataless(dns_fd, userid, &users[userid].q) == 1)
/* new packet from queue, send immediately */
didsend = 0;
}
/* Save new query and time info */
memcpy(&(users[userid].q), q, sizeof(struct query));
users[userid].last_pkt = time(NULL);
/* If anything waiting and we didn't already send above, send
it now. And always send immediately if we're not lazy
(then above won't have sent at all). TODO only call send_frag if sending */
if ((!didsend) || !users[userid].lazy)
send_frag_or_dataless(dns_fd, userid, &users[userid].q);
} else if((in[0] >= '0' && in[0] <= '9') /* Upstream data packet */ } else if((in[0] >= '0' && in[0] <= '9') /* Upstream data packet */
|| (in[0] >= 'a' && in[0] <= 'f') || (in[0] >= 'a' && in[0] <= 'f')
|| (in[0] >= 'A' && in[0] <= 'F')) { || (in[0] >= 'A' && in[0] <= 'F')) {
int didsend = 0;
int code = -1; int code = -1;
static fragment f; static fragment f;
size_t len;
/* Need 6 char header + >=1 char data */ /* Need 6 char header + >=1 char data */
if (domain_len < 7) if (domain_len < 7)
@ -1699,8 +1612,10 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
different id, then all okay. different id, then all okay.
Else client doesn't get our ack, and will retransmit in Else client doesn't get our ack, and will retransmit in
1 second. */ 1 second. */
if (q->id == 0) if (q->id == 0) {
warnx("Query with ID 0!");
return; return;
}
if ((in[0] >= '0' && in[0] <= '9')) if ((in[0] >= '0' && in[0] <= '9'))
code = in[0] - '0'; code = in[0] - '0';
@ -1721,142 +1636,41 @@ handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query
if (answer_from_dnscache(dns_fd, userid, q)) if (answer_from_dnscache(dns_fd, userid, q))
return; return;
#endif #endif
/* TODO: incoming query buffer/handling for lazy mode */
/* Check if duplicate (and not in full dnscache any more) */ /* TODO: Check if duplicate of waiting queries (ping and data) */
if (answer_from_qmem_data(dns_fd, userid, q))
return;
/* Check if duplicate of waiting queries; impatient DNS relays
like to re-try early and often (with _different_ .id!) */
if (users[userid].q.id != 0 &&
q->type == users[userid].q.type &&
!strcmp(q->name, users[userid].q.name) &&
users[userid].lazy) {
/* We have this packet already, and it's waiting to be
answered. Always keep the last duplicate, since the
relay may have forgotten its first version already.
Our answer will go to both.
(If we already sent an answer, qmem/cache will
have triggered.) */
if (debug >= 2) {
fprintf(stderr, "IN pkt from user %d = dupe from impatient DNS server, remembering\n", userid);
}
users[userid].q.id2 = q->id;
users[userid].q.fromlen2 = q->fromlen;
memcpy(&(users[userid].q.from2), &(q->from), q->fromlen);
return;
}
if (users[userid].q_sendrealsoon.id != 0 &&
q->type == users[userid].q_sendrealsoon.type &&
!strcmp(q->name, users[userid].q_sendrealsoon.name)) {
/* Outer select loop will send answer immediately to both queries. */
if (debug >= 2) {
fprintf(stderr, "IN pkt from user %d = dupe from impatient DNS server, remembering\n", userid);
}
users[userid].q_sendrealsoon.id2 = q->id;
users[userid].q_sendrealsoon.fromlen2 = q->fromlen;
memcpy(&(users[userid].q_sendrealsoon.from2), &(q->from), q->fromlen);
return;
}
/* Decode upstream data header - see docs/proto_XXXXXXXX.txt */ /* Decode upstream data header - see docs/proto_XXXXXXXX.txt */
/* First byte (after userid) = CMC (ignored?) */ /* First byte (after userid) = CMC (ignored) */
f.seqID = (b32_8to5(in[2]) << 2) | (b32_8to5(in[3]) >> 2); // f.seqID = (b32_8to5(in[2]) << 2) | (b32_8to5(in[3]) >> 2);
f.ack_other = (b32_8to5(in[5]) & 8) ? ((b32_8to5(in[3]) & 3) << 6) // f.ack_other = (b32_8to5(in[5]) & 8) ? ((b32_8to5(in[3]) & 3) << 6)
| (b32_8to5(in[4]) << 1) | (b32_8to5(in[5]) & 1) : -1; // | (b32_8to5(in[4]) << 1) | ((b32_8to5(in[5]) >> 4) & 1) : -1;
f.is_nack = (b32_8to5(in[5]) >> 2) & 1; // f.is_nack = (b32_8to5(in[5]) >> 2) & 1;
f.start = (b32_8to5(in[5]) >> 1) & 1; // f.start = (b32_8to5(in[5]) >> 1) & 1;
f.end = b32_8to5(in[5]) & 1; // f.end = b32_8to5(in[5]) & 1;
len = sizeof(unpacked);
read = b32->decode(unpacked, &len, in + 2, 5);
f.seqID = unpacked[0];
unpacked[2] >>= 4; /* Lower 4 bits are unused */
f.ack_other = ((unpacked[2] >> 3) & 1) ? unpacked[1] : -1;
f.is_nack = (unpacked[2] >> 2) & 1;
f.start = (unpacked[2] >> 1) & 1;
f.end = unpacked[2] & 1;
/* Decode remainder of data with user encoding */ /* Decode remainder of data with user encoding */
read = unpack_data(unpacked, sizeof(unpacked), in + UPSTREAM_HDR, read = unpack_data(unpacked, sizeof(unpacked), in + UPSTREAM_HDR,
domain_len - UPSTREAM_HDR, users[userid].encoder); domain_len - UPSTREAM_HDR, users[userid].encoder);
if (debug >= 4) warnx("++++ UNPACKED %d bytes into %lu using %s with header len %d",
domain_len, read, users[userid].encoder->name, UPSTREAM_HDR);
f.len = MIN(read, MAX_FRAGSIZE); f.len = MIN(read, MAX_FRAGSIZE);
memcpy(f.data, unpacked, read); memcpy(f.data, unpacked, f.len);
window_process_incoming_fragment(users[userid].incoming, &f); window_process_incoming_fragment(users[userid].incoming, &f);
window_ack(users[userid].outgoing, f.ack_other); window_ack(users[userid].outgoing, f.ack_other);
/* if waiting for an ACK to be sent back upstream (on incoming buffer) */ send_data_or_ping_response(tun_fd, dns_fd, dns_fds, userid, q, 0);
if (users[userid].next_upstream_ack < 0) {
users[userid].next_upstream_ack = window_get_next_ack(users[userid].incoming);
}
read = window_reassemble_data(users[userid].incoming, (uint8_t *)unpacked, sizeof(unpacked), NULL);
if (read > 0) { /* Data reassembled successfully + cleared out of buffer */
handle_full_packet(tun_fd, dns_fds, userid, (uint8_t *)unpacked, read);
}
window_tick(users[userid].incoming);
/* If there is a query that must be returned real soon, do it.
Includes an ack of the just received upstream fragment,
may contain new data. */
if (users[userid].q_sendrealsoon.id != 0) {
didsend = 1;
if (send_frag_or_dataless(dns_fd, userid, &users[userid].q_sendrealsoon) == 1)
/* new packet from queue, send immediately */
didsend = 0;
}
/* If we already have an earlier query waiting, we need to
get rid of it to store the new query.
- If we have new data waiting and not yet sent above, send immediately.
- If this wasn't the last upstream fragment, then we expect
more, so ack immediately if we didn't already.
- If we are in non-lazy mode, there should be no query
waiting, but if there is, send immediately.
- In all other cases (mostly the last-fragment cases),
we can afford to wait just a tiny little while for the
TCP ack to arrive from our tun. Note that this works best
when there is only one client.
*/
// if (users[userid].q.id != 0) {
// if ((users[userid].outpacket.len > 0 && !didsend) ||
// (upstream_ok && !lastfrag && !didsend) ||
// (!upstream_ok && !didsend) ||
// !users[userid].lazy) {
// didsend = 1;
// if (send_frag_or_dataless(dns_fd, userid, &users[userid].q) == 1)
// /* new packet from queue, send immediately */
// didsend = 0;
// } else {
// memcpy(&(users[userid].q_sendrealsoon), &(users[userid].q),
// sizeof(struct query));
// users[userid].q_sendrealsoon_new = 1;
// users[userid].q.id = 0; /* used */
// didsend = 1;
// }
// }
/* Save new query and time info */
memcpy(&(users[userid].q), q, sizeof(struct query));
users[userid].last_pkt = time(NULL);
/* If we still need to ack this upstream frag, do it to keep
upstream flowing.
- If we have new data waiting and not yet sent above,
send immediately.
- If this wasn't the last upstream fragment, then we expect
more, so ack immediately if we didn't already or are
in non-lazy mode.
- If this was the last fragment, and we didn't ack already
or are in non-lazy mode, send the ack after just a tiny
little while so that the TCP ack may have arrived from
our tun device.
- In all other cases, don't send anything now. */
if (!didsend) // TODO: also check if sending
send_frag_or_dataless(dns_fd, userid, &users[userid].q);
else if (!didsend || !users[userid].lazy) {
memcpy(&(users[userid].q_sendrealsoon), &(users[userid].q), sizeof(struct query));
users[userid].q_sendrealsoon_new = 1;
users[userid].q.id = 0; /* used */
}
} }
} }
@ -1882,8 +1696,8 @@ handle_ns_request(int dns_fd, struct query *q)
} }
if (debug >= 2) { if (debug >= 2) {
fprintf(stderr, "TX: client %s, type %d, name %s, %d bytes NS reply\n", fprintf(stderr, "TX: client %s ID %5d, type %d, name %s, %d bytes NS reply\n",
format_addr(&q->from, q->fromlen), q->type, q->name, len); format_addr(&q->from, q->fromlen), q->id, q->type, q->name, len);
} }
if (sendto(dns_fd, buf, len, 0, (struct sockaddr*)&q->from, q->fromlen) <= 0) { if (sendto(dns_fd, buf, len, 0, (struct sockaddr*)&q->from, q->fromlen) <= 0) {
warn("ns reply send error"); warn("ns reply send error");
@ -1916,8 +1730,8 @@ handle_a_request(int dns_fd, struct query *q, int fakeip)
} }
if (debug >= 2) { if (debug >= 2) {
fprintf(stderr, "TX: client %s, type %d, name %s, %d bytes A reply\n", fprintf(stderr, "TX: client %s ID %5d, type %d, name %s, %d bytes A reply\n",
format_addr(&q->from, q->fromlen), q->type, q->name, len); format_addr(&q->from, q->fromlen), q->id, q->type, q->name, len);
} }
if (sendto(dns_fd, buf, len, 0, (struct sockaddr*)&q->from, q->fromlen) <= 0) { if (sendto(dns_fd, buf, len, 0, (struct sockaddr*)&q->from, q->fromlen) <= 0) {
warn("a reply send error"); warn("a reply send error");

11
src/server.h
View File

@ -47,6 +47,15 @@
#define QMEMDATA_LEN 15 #define QMEMDATA_LEN 15
/* Max advisable: 36/2 = 18. Total mem usage: QMEMDATA_LEN * USERS * 6 bytes */ /* Max advisable: 36/2 = 18. Total mem usage: QMEMDATA_LEN * USERS * 6 bytes */
/* Number of fragments in outgoing buffer.
* Mem usage: USERS * (MAX_FRAGLEN * OUTFRAGBUF_LEN + sizeof(struct window_buffer) */
#define OUTFRAGBUF_LEN 64
/* Number of fragments in incoming buffer
* Minimum recommended = ((max packet size or MTU) / (max up fragsize)) * 2
* ie. (1200 / 100) * 2 = 24 */
#define INFRAGBUF_LEN 32
#define PASSWORD_ENV_VAR "IODINED_PASS" #define PASSWORD_ENV_VAR "IODINED_PASS"
#if defined IP_RECVDSTADDR #if defined IP_RECVDSTADDR
@ -102,7 +111,7 @@ void server_stop();
int server_tunnel(int tun_fd, struct dnsfd *dns_fds, int bind_fd, int max_idle_time); int server_tunnel(int tun_fd, struct dnsfd *dns_fds, int bind_fd, int max_idle_time);
int read_dns(int fd, struct dnsfd *dns_fds, int tun_fd, struct query *q); int read_dns(int fd, struct dnsfd *dns_fds, int tun_fd, struct query *q);
void write_dns(int fd, struct query *q, char *data, int datalen, char downenc); void write_dns(int fd, struct query *q, char *data, size_t datalen, char downenc);
void handle_full_packet(int tun_fd, struct dnsfd *dns_fds, int userid, uint8_t *data, size_t len); void handle_full_packet(int tun_fd, struct dnsfd *dns_fds, int userid, uint8_t *data, size_t len);
void handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query *q, int domain_len); void handle_null_request(int tun_fd, int dns_fd, struct dnsfd *dns_fds, struct query *q, int domain_len);
void handle_ns_request(int dns_fd, struct query *q); void handle_ns_request(int dns_fd, struct query *q);