mirror of
https://github.com/yarrick/iodine.git
synced 2024-11-22 16:19:20 +02:00
update server code #75
This commit is contained in:
J. A. Bezemer
Erik Ekman
parent
55cfed9956
commit
40167437d3
199
src/iodined.c
199
src/iodined.c
|
|
@ -68,6 +68,7 @@ static int running = 1;
|
|||
static char *topdomain;
|
||||
static char password[33];
|
||||
static struct encoder *b32;
|
||||
static struct encoder *b64;
|
||||
static int created_users;
|
||||
|
||||
static int check_ip;
|
||||
|
|
@ -85,7 +86,7 @@ static char *__progname;
|
|||
#endif
|
||||
|
||||
static int read_dns(int, int, struct query *);
|
||||
static void write_dns(int, struct query *, char *, int);
|
||||
static void write_dns(int, struct query *, char *, int, char);
|
||||
static void handle_full_packet(int, int);
|
||||
|
||||
static void
|
||||
|
|
@ -119,7 +120,7 @@ check_user_and_ip(int userid, struct query *q)
|
|||
if (userid < 0 || userid >= created_users ) {
|
||||
return 1;
|
||||
}
|
||||
if (!users[userid].active) {
|
||||
if (!users[userid].active || users[userid].disabled) {
|
||||
return 1;
|
||||
}
|
||||
if (users[userid].last_pkt + 60 < time(NULL)) {
|
||||
|
|
@ -225,7 +226,7 @@ send_version_response(int fd, version_ack_t ack, uint32_t payload, int userid, s
|
|||
out[7] = ((payload) & 0xff);
|
||||
out[8] = userid & 0xff;
|
||||
|
||||
write_dns(fd, q, out, sizeof(out));
|
||||
write_dns(fd, q, out, sizeof(out), users[userid].downenc);
|
||||
}
|
||||
|
||||
static void
|
||||
|
|
@ -270,7 +271,7 @@ send_chunk(int dns_fd, int userid) {
|
|||
users[userid].outpacket.seqno & 7, users[userid].outpacket.fragment & 15,
|
||||
last, users[userid].outpacket.offset, datalen, users[userid].outpacket.len, userid);
|
||||
}
|
||||
write_dns(dns_fd, &users[userid].q, pkt, datalen + 2);
|
||||
write_dns(dns_fd, &users[userid].q, pkt, datalen + 2, users[userid].downenc);
|
||||
users[userid].q.id = 0;
|
||||
|
||||
if (users[userid].outpacket.len > 0 &&
|
||||
|
|
@ -360,10 +361,21 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
|
||||
memcpy(&(users[userid].q), q, sizeof(struct query));
|
||||
users[userid].encoder = get_base32_encoder();
|
||||
users[userid].downenc = 'T';
|
||||
send_version_response(dns_fd, VERSION_ACK, users[userid].seed, userid, q);
|
||||
syslog(LOG_INFO, "accepted version for user #%d from %s",
|
||||
userid, inet_ntoa(tempin->sin_addr));
|
||||
users[userid].q.id = 0;
|
||||
users[userid].outpacket.len = 0;
|
||||
users[userid].outpacket.offset = 0;
|
||||
users[userid].outpacket.sentlen = 0;
|
||||
users[userid].outpacket.seqno = 0;
|
||||
users[userid].outpacket.fragment = 0;
|
||||
users[userid].inpacket.len = 0;
|
||||
users[userid].inpacket.offset = 0;
|
||||
users[userid].inpacket.seqno = 0;
|
||||
users[userid].inpacket.fragment = 0;
|
||||
users[userid].fragsize = 100; /* very safe */
|
||||
} else {
|
||||
/* No space for another user */
|
||||
send_version_response(dns_fd, VERSION_FULL, created_users, 0, q);
|
||||
|
|
@ -382,7 +394,7 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
userid = unpacked[0];
|
||||
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5);
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
syslog(LOG_WARNING, "dropped login request from user #%d from unexpected source %s",
|
||||
userid, inet_ntoa(((struct sockaddr_in *) &q->from)->sin_addr));
|
||||
return;
|
||||
|
|
@ -401,14 +413,14 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
read = snprintf(out, sizeof(out), "%s-%s-%d-%d",
|
||||
tmp[0], tmp[1], my_mtu, netmask);
|
||||
|
||||
write_dns(dns_fd, q, out, read);
|
||||
write_dns(dns_fd, q, out, read, users[userid].downenc);
|
||||
q->id = 0;
|
||||
syslog(LOG_NOTICE, "accepted password from user #%d, given IP %s", userid, tmp[1]);
|
||||
|
||||
free(tmp[1]);
|
||||
free(tmp[0]);
|
||||
} else {
|
||||
write_dns(dns_fd, q, "LNAK", 4);
|
||||
write_dns(dns_fd, q, "LNAK", 4, 'T');
|
||||
syslog(LOG_WARNING, "rejected login request from user #%d from %s, bad password",
|
||||
userid, inet_ntoa(((struct sockaddr_in *) &q->from)->sin_addr));
|
||||
}
|
||||
|
|
@ -422,7 +434,7 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
|
||||
userid = b32_8to5(in[1]);
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5);
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
return; /* illegal id */
|
||||
}
|
||||
|
||||
|
|
@ -440,25 +452,26 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
reply[2] = (addr >> 16) & 0xFF;
|
||||
reply[3] = (addr >> 8) & 0xFF;
|
||||
reply[4] = (addr >> 0) & 0xFF;
|
||||
write_dns(dns_fd, q, reply, sizeof(reply));
|
||||
write_dns(dns_fd, q, reply, sizeof(reply), 'T');
|
||||
} else if(in[0] == 'Z' || in[0] == 'z') {
|
||||
/* Check for case conservation and chars not allowed according to RFC */
|
||||
|
||||
/* Reply with received hostname as data */
|
||||
write_dns(dns_fd, q, in, domain_len);
|
||||
/* No userid here, reply with lowest-grade downenc */
|
||||
write_dns(dns_fd, q, in, domain_len, 'T');
|
||||
return;
|
||||
} else if(in[0] == 'S' || in[0] == 's') {
|
||||
int codec;
|
||||
struct encoder *enc;
|
||||
if (domain_len < 3) { /* len at least 3, example: "S15" */
|
||||
write_dns(dns_fd, q, "BADLEN", 6);
|
||||
write_dns(dns_fd, q, "BADLEN", 6, 'T');
|
||||
return;
|
||||
}
|
||||
|
||||
userid = b32_8to5(in[1]);
|
||||
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5);
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
return; /* illegal id */
|
||||
}
|
||||
|
||||
|
|
@ -468,15 +481,49 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
case 5: /* 5 bits per byte = base32 */
|
||||
enc = get_base32_encoder();
|
||||
user_switch_codec(userid, enc);
|
||||
write_dns(dns_fd, q, enc->name, strlen(enc->name));
|
||||
write_dns(dns_fd, q, enc->name, strlen(enc->name), users[userid].downenc);
|
||||
break;
|
||||
case 6: /* 6 bits per byte = base64 */
|
||||
enc = get_base64_encoder();
|
||||
user_switch_codec(userid, enc);
|
||||
write_dns(dns_fd, q, enc->name, strlen(enc->name));
|
||||
write_dns(dns_fd, q, enc->name, strlen(enc->name), users[userid].downenc);
|
||||
break;
|
||||
default:
|
||||
write_dns(dns_fd, q, "BADCODEC", 8);
|
||||
write_dns(dns_fd, q, "BADCODEC", 8, users[userid].downenc);
|
||||
break;
|
||||
}
|
||||
return;
|
||||
} else if(in[0] == 'O' || in[0] == 'o') {
|
||||
if (domain_len != 4) { /* len = 4, example: "O1T." */
|
||||
write_dns(dns_fd, q, "BADLEN", 6, 'T');
|
||||
return;
|
||||
}
|
||||
|
||||
userid = b32_8to5(in[1]);
|
||||
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
return; /* illegal id */
|
||||
}
|
||||
|
||||
switch (in[2]) {
|
||||
case 'T':
|
||||
case 't':
|
||||
users[userid].downenc = 'T';
|
||||
write_dns(dns_fd, q, "Base32", 6, users[userid].downenc);
|
||||
break;
|
||||
case 'S':
|
||||
case 's':
|
||||
users[userid].downenc = 'S';
|
||||
write_dns(dns_fd, q, "Base64", 6, users[userid].downenc);
|
||||
break;
|
||||
case 'R':
|
||||
case 'r':
|
||||
users[userid].downenc = 'R';
|
||||
write_dns(dns_fd, q, "Raw", 3, users[userid].downenc);
|
||||
break;
|
||||
default:
|
||||
write_dns(dns_fd, q, "BADCODEC", 8, users[userid].downenc);
|
||||
break;
|
||||
}
|
||||
return;
|
||||
|
|
@ -486,20 +533,26 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
/* Downstream fragsize probe packet */
|
||||
userid = (b32_8to5(in[1]) >> 1) & 15;
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5);
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
return; /* illegal id */
|
||||
}
|
||||
|
||||
req_frag_size = ((b32_8to5(in[1]) & 1) << 10) | ((b32_8to5(in[2]) & 31) << 5) | (b32_8to5(in[3]) & 31);
|
||||
if (req_frag_size < 2 || req_frag_size > 2047) {
|
||||
write_dns(dns_fd, q, "BADFRAG", 7);
|
||||
write_dns(dns_fd, q, "BADFRAG", 7, users[userid].downenc);
|
||||
} else {
|
||||
char buf[2048];
|
||||
int i;
|
||||
unsigned int v = (unsigned int) rand();
|
||||
|
||||
memset(buf, 0, sizeof(buf));
|
||||
buf[0] = (req_frag_size >> 8) & 0xff;
|
||||
buf[1] = req_frag_size & 0xff;
|
||||
write_dns(dns_fd, q, buf, req_frag_size);
|
||||
/* make checkable pseudo-random sequence */
|
||||
buf[2] = 107;
|
||||
for (i = 3; i < 2048; i++, v += 107)
|
||||
buf[i] = (char) (v & 0xff);
|
||||
write_dns(dns_fd, q, buf, req_frag_size, users[userid].downenc);
|
||||
}
|
||||
return;
|
||||
} else if(in[0] == 'N' || in[0] == 'n') {
|
||||
|
|
@ -509,16 +562,16 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
/* Downstream fragsize packet */
|
||||
userid = unpacked[0];
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5);
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
return; /* illegal id */
|
||||
}
|
||||
|
||||
max_frag_size = ((unpacked[1] & 0xff) << 8) | (unpacked[2] & 0xff);
|
||||
if (max_frag_size < 2) {
|
||||
write_dns(dns_fd, q, "BADFRAG", 7);
|
||||
write_dns(dns_fd, q, "BADFRAG", 7, users[userid].downenc);
|
||||
} else {
|
||||
users[userid].fragsize = max_frag_size;
|
||||
write_dns(dns_fd, q, &unpacked[1], 2);
|
||||
write_dns(dns_fd, q, &unpacked[1], 2, users[userid].downenc);
|
||||
}
|
||||
return;
|
||||
} else if(in[0] == 'P' || in[0] == 'p') {
|
||||
|
|
@ -529,7 +582,7 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
/* Ping packet, store userid */
|
||||
userid = unpacked[0];
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5);
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
return; /* illegal id */
|
||||
}
|
||||
|
||||
|
|
@ -564,7 +617,7 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
|
|||
userid = code;
|
||||
/* Check user and sending ip number */
|
||||
if (check_user_and_ip(userid, q) != 0) {
|
||||
write_dns(dns_fd, q, "BADIP", 5);
|
||||
write_dns(dns_fd, q, "BADIP", 5, 'T');
|
||||
} else {
|
||||
/* Decode data header */
|
||||
int up_seq = (b32_8to5(in[1]) >> 2) & 7;
|
||||
|
|
@ -637,6 +690,10 @@ handle_ns_request(int dns_fd, struct query *q)
|
|||
}
|
||||
|
||||
len = dns_encode_ns_response(buf, sizeof(buf), q, topdomain);
|
||||
if (len < 1) {
|
||||
warnx("dns_encode_ns_response doesn't fit");
|
||||
return;
|
||||
}
|
||||
|
||||
if (debug >= 2) {
|
||||
struct sockaddr_in *tempin;
|
||||
|
|
@ -659,6 +716,10 @@ forward_query(int bind_fd, struct query *q)
|
|||
in_addr_t newaddr;
|
||||
|
||||
len = dns_encode(buf, sizeof(buf), q, QR_QUERY, q->name, strlen(q->name));
|
||||
if (len < 1) {
|
||||
warnx("dns_encode doesn't fit");
|
||||
return;
|
||||
}
|
||||
|
||||
/* Store sockaddr for q->id */
|
||||
memcpy(&(fwq.addr), &(q->from), q->fromlen);
|
||||
|
|
@ -755,8 +816,14 @@ tunnel_dns(int tun_fd, int dns_fd, int bind_fd)
|
|||
|
||||
if (inside_topdomain) {
|
||||
/* This is a query we can handle */
|
||||
|
||||
switch (q.type) {
|
||||
case T_NULL:
|
||||
case T_CNAME:
|
||||
case T_A:
|
||||
case T_MX:
|
||||
case T_TXT:
|
||||
/* encoding is "transparent" here */
|
||||
handle_null_request(tun_fd, dns_fd, &q, domain_len);
|
||||
break;
|
||||
case T_NS:
|
||||
|
|
@ -1044,12 +1111,91 @@ read_dns(int fd, int tun_fd, struct query *q) /* FIXME: tun_fd is because of raw
|
|||
}
|
||||
|
||||
static void
|
||||
write_dns(int fd, struct query *q, char *data, int datalen)
|
||||
write_dns(int fd, struct query *q, char *data, int datalen, char downenc)
|
||||
{
|
||||
char buf[64*1024];
|
||||
int len;
|
||||
int len = 0;
|
||||
|
||||
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, data, datalen);
|
||||
if (q->type == T_CNAME || q->type == T_A || q->type == T_MX) {
|
||||
static int td1 = 0;
|
||||
static int td2 = 0;
|
||||
char cnamebuf[1024]; /* max 255 */
|
||||
size_t space;
|
||||
char *b;
|
||||
|
||||
/* Make a rotating topdomain to prevent filtering */
|
||||
td1+=3;
|
||||
td2+=7;
|
||||
if (td1>=26) td1-=26;
|
||||
if (td2>=25) td2-=25;
|
||||
|
||||
/* encode data,datalen to CNAME/MX answer */
|
||||
/* (adapted from build_hostname() in iodine.c) */
|
||||
|
||||
space = MIN(0xFF, sizeof(cnamebuf)) - 4 - 2;
|
||||
/* -1 encoding type, -3 ".xy", -2 for safety */
|
||||
|
||||
memset(cnamebuf, 0, sizeof(cnamebuf));
|
||||
|
||||
if (downenc == 'S') {
|
||||
cnamebuf[0] = 'I';
|
||||
if (!b64->places_dots())
|
||||
space -= (space / 57); /* space for dots */
|
||||
b64->encode(cnamebuf+1, &space, data, datalen);
|
||||
if (!b64->places_dots())
|
||||
inline_dotify(cnamebuf, sizeof(cnamebuf), 57);
|
||||
} else {
|
||||
cnamebuf[0] = 'H';
|
||||
if (!b32->places_dots())
|
||||
space -= (space / 57); /* space for dots */
|
||||
b32->encode(cnamebuf+1, &space, data, datalen);
|
||||
if (!b32->places_dots())
|
||||
inline_dotify(cnamebuf, sizeof(cnamebuf), 57);
|
||||
}
|
||||
|
||||
/* Add dot (if it wasn't there already) and topdomain */
|
||||
b = cnamebuf;
|
||||
b += strlen(cnamebuf);
|
||||
if (*b != '.')
|
||||
*b++ = '.';
|
||||
|
||||
*b = 'a' + td1;
|
||||
b++;
|
||||
*b = 'a' + td2;
|
||||
b++;
|
||||
*b = '\0';
|
||||
|
||||
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, cnamebuf, sizeof(cnamebuf));
|
||||
}
|
||||
else if (q->type == T_TXT) {
|
||||
/* TXT with base32 */
|
||||
char txtbuf[64*1024];
|
||||
size_t space = sizeof(txtbuf) - 1;;
|
||||
|
||||
memset(txtbuf, 0, sizeof(txtbuf));
|
||||
|
||||
if (downenc == 'S') {
|
||||
txtbuf[0] = 'S'; /* plain base64(Sixty-four) */
|
||||
len = b64->encode(txtbuf+1, &space, data, datalen);
|
||||
}
|
||||
else if (downenc == 'R') {
|
||||
txtbuf[0] = 'R'; /* Raw binary data */
|
||||
len = MIN(datalen, sizeof(txtbuf) - 1);
|
||||
memcpy(txtbuf + 1, data, len);
|
||||
} else {
|
||||
txtbuf[0] = 'T'; /* plain base32(Thirty-two) */
|
||||
len = b32->encode(txtbuf+1, &space, data, datalen);
|
||||
}
|
||||
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, txtbuf, len+1);
|
||||
} else {
|
||||
/* Normal NULL-record encode */
|
||||
len = dns_encode(buf, sizeof(buf), q, QR_ANSWER, data, datalen);
|
||||
}
|
||||
|
||||
if (len < 1) {
|
||||
warnx("dns_encode doesn't fit");
|
||||
return;
|
||||
}
|
||||
|
||||
if (debug >= 2) {
|
||||
struct sockaddr_in *tempin;
|
||||
|
|
@ -1166,6 +1312,7 @@ main(int argc, char **argv)
|
|||
pidfile = NULL;
|
||||
|
||||
b32 = get_base32_encoder();
|
||||
b64 = get_base64_encoder();
|
||||
|
||||
retval = 0;
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue