#75, update client code
This commit is contained in:
Erik Ekman
parent
bd4a4eb24c
commit
83dfde0728
356
src/client.c
356
src/client.c
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@ -14,6 +14,7 @@
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <ctype.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <stdlib.h>
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@ -75,12 +76,20 @@ static char userid;
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/* DNS id for next packet */
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static uint16_t chunkid;
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/* Base32 encoder used for non-data packets */
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/* Base32 encoder used for non-data packets and replies */
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static struct encoder *b32;
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/* Base64 encoder for replies */
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static struct encoder *b64;
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/* The encoder used for data packets
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* Defaults to Base32, can be changed after handshake */
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static struct encoder *dataenc;
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/* The encoder to use for downstream data */
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static char downenc = ' ';
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/* set query type to send */
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static unsigned short do_qtype = T_NULL;
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/* My connection mode */
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static enum connection conn;
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@ -95,10 +104,11 @@ client_init()
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downstream_fragment = 0;
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down_ack_seqno = 0;
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down_ack_fragment = 0;
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chunkid = 0;
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chunkid = ((unsigned int) rand()) & 0xFFFF;
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b32 = get_base32_encoder();
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b64 = get_base64_encoder();
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dataenc = get_base32_encoder();
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rand_seed = rand();
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rand_seed = ((unsigned int) rand()) & 0xFFFF;
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conn = CONN_DNS_NULL;
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}
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@ -140,6 +150,32 @@ client_set_password(const char *cp)
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password = cp;
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}
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void
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set_qtype(char *qtype)
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{
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if (!strcasecmp(qtype, "NULL"))
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do_qtype = T_NULL;
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else if (!strcasecmp(qtype, "CNAME"))
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do_qtype = T_CNAME;
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else if (!strcasecmp(qtype, "A"))
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do_qtype = T_A;
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else if (!strcasecmp(qtype, "MX"))
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do_qtype = T_MX;
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else if (!strcasecmp(qtype, "TXT"))
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do_qtype = T_TXT;
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}
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void
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set_downenc(char *encoding)
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{
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if (!strcasecmp(encoding, "base32"))
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downenc = 'T';
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else if (!strcasecmp(encoding, "base64"))
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downenc = 'S';
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else if (!strcasecmp(encoding, "raw"))
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downenc = 'R';
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}
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const char *
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client_get_raw_addr()
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{
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@ -153,10 +189,19 @@ send_query(int fd, char *hostname)
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struct query q;
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size_t len;
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q.id = ++chunkid;
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q.type = T_NULL;
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chunkid += 7727;
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if (chunkid == 0)
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/* 0 is used as "no-query" in iodined.c */
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chunkid = 7727;
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q.id = chunkid;
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q.type = do_qtype;
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len = dns_encode(packet, sizeof(packet), &q, QR_QUERY, hostname, strlen(hostname));
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if (len < 1) {
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warnx("dns_encode doesn't fit");
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return;
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}
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sendto(fd, packet, len, 0, (struct sockaddr*)&nameserv, sizeof(nameserv));
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}
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@ -207,7 +252,7 @@ is_sending()
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static void
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send_chunk(int fd)
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{
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char hex[] = "0123456789ABCDEF";
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char hex[] = "0123456789abcdef";
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char buf[4096];
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int avail;
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int code;
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@ -261,7 +306,7 @@ send_ping(int fd)
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rand_seed++;
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send_packet(fd, 'P', data, sizeof(data));
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send_packet(fd, 'p', data, sizeof(data));
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} else {
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send_raw(fd, NULL, 0, userid, RAW_HDR_CMD_PING);
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}
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@ -288,6 +333,88 @@ read_dns(int dns_fd, int tun_fd, char *buf, int buflen) /* FIXME: tun_fd needed
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rv = dns_decode(buf, buflen, &q, QR_ANSWER, data, r);
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if ((q.type == T_CNAME || q.type == T_MX || q.type == T_TXT)
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&& rv >= 1)
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/* CNAME an also be returned from an A (or MX) question */
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{
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size_t space;
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/*
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* buf is a hostname or txt stream that we still need to
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* decode to binary
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*
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* also update rv with the number of valid bytes
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*
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* data is unused here, and will certainly hold the smaller binary
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*/
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switch (buf[0]) {
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case 'h': /* Hostname with base32 */
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case 'H':
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if (rv < 5) {
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/* 1 byte H, 3 bytes ".xy", >=1 byte data */
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rv = 0;
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break;
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}
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rv -= 3; /* rv=strlen, strip ".xy" */
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rv = unpack_data (data, sizeof(data), buf + 1, rv - 1, b32);
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/* this also does undotify */
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rv = MIN(rv, buflen);
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memcpy(buf, data, rv);
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break;
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case 'i': /* Hostname++ with base64 */
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case 'I':
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if (rv < 5) {
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/* 1 byte H, 3 bytes ".xy", >=1 byte data */
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rv = 0;
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break;
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}
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rv -= 3; /* rv=strlen, strip ".xy" */
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rv = unpack_data (data, sizeof(data), buf + 1, rv - 1, b64);
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/* this also does undotify */
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rv = MIN(rv, buflen);
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memcpy(buf, data, rv);
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break;
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case 't': /* plain base32(Thirty-two) from TXT */
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case 'T':
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if (rv < 2) {
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rv = 0;
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break;
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}
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space = sizeof(data);
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rv = b32->decode (data, &space, buf + 1, rv - 1);
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rv = MIN(rv, buflen);
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memcpy(buf, data, rv);
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break;
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case 's': /* plain base64(Sixty-four) from TXT */
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case 'S':
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if (rv < 2) {
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rv = 0;
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break;
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}
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space = sizeof(data);
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rv = b64->decode (data, &space, buf + 1, rv - 1);
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rv = MIN(rv, buflen);
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memcpy(buf, data, rv);
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break;
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case 'r': /* Raw binary from TXT */
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case 'R':
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rv--; /* rv>=1 already checked */
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memmove(buf, buf+1, rv);
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break;
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default:
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warnx("Received unsupported encoding");
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rv = 0;
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break;
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}
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}
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/* decode the data header, update seqno and frag before next request */
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if (rv >= 2) {
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downstream_seqno = (buf[1] >> 5) & 7;
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@ -311,7 +438,7 @@ read_dns(int dns_fd, int tun_fd, char *buf, int buflen) /* FIXME: tun_fd needed
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downstream_seqno != down_ack_seqno ||
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downstream_fragment != down_ack_fragment
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)) {
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send_ping(dns_fd);
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}
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} else {
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@ -487,7 +614,7 @@ send_login(int fd, char *login, int len)
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rand_seed++;
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send_packet(fd, 'L', data, sizeof(data));
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send_packet(fd, 'l', data, sizeof(data));
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}
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static void
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@ -496,9 +623,12 @@ send_fragsize_probe(int fd, int fragsize)
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char probedata[256];
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char buf[4096];
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/* build a large query domain which is random and maximum size */
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memset(probedata, MIN(1, rand_seed & 0xff), sizeof(probedata));
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probedata[1] = MIN(1, (rand_seed >> 8) & 0xff);
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/*
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* build a large query domain which is random and maximum size,
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* will also take up maximal space in the return packet
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*/
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memset(probedata, MAX(1, rand_seed & 0xff), sizeof(probedata));
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probedata[1] = MAX(1, (rand_seed >> 8) & 0xff);
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rand_seed++;
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build_hostname(buf + 4, sizeof(buf) - 4, probedata, sizeof(probedata), topdomain, dataenc);
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@ -525,14 +655,14 @@ send_set_downstream_fragsize(int fd, int fragsize)
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rand_seed++;
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send_packet(fd, 'N', data, sizeof(data));
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send_packet(fd, 'n', data, sizeof(data));
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}
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static void
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send_version(int fd, uint32_t version)
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{
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char data[6];
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data[0] = (version >> 24) & 0xff;
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data[1] = (version >> 16) & 0xff;
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data[2] = (version >> 8) & 0xff;
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@ -585,7 +715,7 @@ 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] = "S_____.";
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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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@ -597,6 +727,23 @@ send_codec_switch(int fd, int userid, int bits)
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strncat(buf, topdomain, 512 - strlen(buf));
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send_query(fd, buf);
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}
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static void
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send_downenc_switch(int fd, int userid)
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{
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char buf[512] = "o_____.";
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buf[1] = b32_5to8(userid);
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buf[2] = tolower(downenc);
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buf[3] = b32_5to8((rand_seed >> 10) & 0x1f);
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buf[4] = b32_5to8((rand_seed >> 5) & 0x1f);
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buf[5] = b32_5to8((rand_seed ) & 0x1f);
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rand_seed++;
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strncat(buf, topdomain, 512 - strlen(buf));
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send_query(fd, buf);
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}
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static int
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handshake_version(int dns_fd, int *seed)
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@ -657,7 +804,7 @@ handshake_version(int dns_fd, int *seed)
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fprintf(stderr, "Retrying version check...\n");
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}
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warnx("couldn't connect to server");
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warnx("couldn't connect to server (maybe other -T options will work)");
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return 1;
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}
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@ -891,7 +1038,7 @@ handshake_switch_codec(int dns_fd)
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int read;
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dataenc = get_base64_encoder();
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fprintf(stderr, "Switching to %s codec\n", dataenc->name);
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fprintf(stderr, "Switching upstream to %s codec\n", dataenc->name);
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/* Send to server that this user will use base64 from now on */
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for (i=0; running && i<5 ;i++) {
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int bits;
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@ -922,7 +1069,7 @@ handshake_switch_codec(int dns_fd)
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goto codec_revert;
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}
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in[read] = 0; /* zero terminate */
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fprintf(stderr, "Server switched to codec %s\n", in);
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fprintf(stderr, "Server switched upstream to codec %s\n", in);
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return;
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}
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}
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@ -935,6 +1082,138 @@ codec_revert:
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dataenc = get_base32_encoder();
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}
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static void
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handshake_switch_downenc(int dns_fd)
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{
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struct timeval tv;
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char in[4096];
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fd_set fds;
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int i;
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int r;
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int read;
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char *dname;
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dname = "Base32";
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if (downenc == 'S')
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dname = "Base64";
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else if (downenc == 'R')
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dname = "Raw";
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fprintf(stderr, "Switching downstream to codec %s\n", dname);
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for (i=0; running && i<5 ;i++) {
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tv.tv_sec = i + 1;
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tv.tv_usec = 0;
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send_downenc_switch(dns_fd, userid);
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FD_ZERO(&fds);
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FD_SET(dns_fd, &fds);
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r = select(dns_fd + 1, &fds, NULL, NULL, &tv);
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if(r > 0) {
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read = read_dns(dns_fd, 0, in, sizeof(in));
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if (read > 0) {
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if (strncmp("BADLEN", in, 6) == 0) {
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fprintf(stderr, "Server got bad message length. ");
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goto codec_revert;
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} else if (strncmp("BADIP", in, 5) == 0) {
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fprintf(stderr, "Server rejected sender IP address. ");
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goto codec_revert;
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} else if (strncmp("BADCODEC", in, 8) == 0) {
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fprintf(stderr, "Server rejected the selected codec. ");
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goto codec_revert;
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}
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in[read] = 0; /* zero terminate */
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fprintf(stderr, "Server switched downstream to codec %s\n", in);
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return;
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}
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}
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fprintf(stderr, "Retrying codec switch...\n");
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}
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fprintf(stderr, "No reply from server on codec switch. ");
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codec_revert:
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fprintf(stderr, "Falling back to base32\n");
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}
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static int
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fragsize_check(char *in, int read, int proposed_fragsize, int *max_fragsize)
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/* Returns: 0: keep checking, 1: break loop (either okay or definitely wrong) */
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{
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int acked_fragsize = ((in[0] & 0xff) << 8) | (in[1] & 0xff);
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static int nocheck_warned = 0;
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if (read >= 5 && strncmp("BADIP", in, 5) == 0) {
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fprintf(stderr, "got BADIP (Try iodined -c)..\n");
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fflush(stderr);
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return 0; /* maybe temporary error */
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}
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if (acked_fragsize != proposed_fragsize) {
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/*
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* got ack for wrong fragsize, maybe late response for
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* earlier query, or ack corrupted
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*/
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return 0;
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}
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if (read != proposed_fragsize) {
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/*
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* correctly acked fragsize but read too little (or too
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* much): this fragsize is definitely not reliable
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*/
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return 1;
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}
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/* here: read == proposed_fragsize == acked_fragsize */
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/* test: */
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/* in[123] = 123; */
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/* Check for corruption */
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if ((in[2] & 0xff) == 107) {
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int okay = 1;
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int i;
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unsigned int v = in[3] & 0xff;
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for (i = 3; i < read; i++, v += 107)
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if ((in[i] & 0xff) != (v & 0xff)) {
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okay = 0;
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break;
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}
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if (okay) {
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fprintf(stderr, "%d ok.. ", acked_fragsize);
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fflush(stderr);
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*max_fragsize = acked_fragsize;
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return 1;
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} else {
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if (downenc != ' ' && downenc != 'T')
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fprintf(stderr, "%d corrupted at %d.. (Try -O Base32)\n", acked_fragsize, i);
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else
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fprintf(stderr, "%d corrupted at %d.. ", acked_fragsize, i);
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fflush(stderr);
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return 1;
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}
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} /* always returns */
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/* here when uncheckable, so assume correct */
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if (read >= 3 && nocheck_warned == 0) {
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fprintf(stderr, "(Old server version, cannot check for corruption)\n");
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fflush(stderr);
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nocheck_warned = 1;
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}
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fprintf(stderr, "%d ok.. ", acked_fragsize);
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fflush(stderr);
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*max_fragsize = acked_fragsize;
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return 1;
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}
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static int
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handshake_autoprobe_fragsize(int dns_fd)
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{
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@ -946,11 +1225,12 @@ handshake_autoprobe_fragsize(int dns_fd)
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int read;
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int proposed_fragsize = 768;
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int range = 768;
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int max_fragsize = 0;
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int max_fragsize;
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max_fragsize = 0;
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fprintf(stderr, "Autoprobing max downstream fragment size... (skip with -m fragsize)\n");
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while (running && range > 0 && (range >= 8 || !max_fragsize)) {
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while (running && range > 0 && (range >= 8 || max_fragsize < 300)) {
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/* stop the slow probing early when we have enough bytes anyway */
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for (i=0; running && i<3 ;i++) {
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tv.tv_sec = 1;
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tv.tv_usec = 0;
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@ -961,24 +1241,13 @@ handshake_autoprobe_fragsize(int dns_fd)
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r = select(dns_fd + 1, &fds, NULL, NULL, &tv);
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if(r > 0) {
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if(r >= 2) {
|
||||
read = read_dns(dns_fd, 0, in, sizeof(in));
|
||||
|
||||
if (read > 0) {
|
||||
/* We got a reply */
|
||||
int acked_fragsize = ((in[0] & 0xff) << 8) | (in[1] & 0xff);
|
||||
if (acked_fragsize == proposed_fragsize) {
|
||||
if (read == proposed_fragsize) {
|
||||
fprintf(stderr, "%d ok.. ", acked_fragsize);
|
||||
fflush(stderr);
|
||||
max_fragsize = acked_fragsize;
|
||||
}
|
||||
}
|
||||
if (strncmp("BADIP", in, 5) == 0) {
|
||||
fprintf(stderr, "got BADIP.. ");
|
||||
fflush(stderr);
|
||||
}
|
||||
break;
|
||||
if (fragsize_check(in, read, proposed_fragsize, &max_fragsize) == 1)
|
||||
break;
|
||||
}
|
||||
}
|
||||
fprintf(stderr, ".");
|
||||
|
|
@ -997,17 +1266,22 @@ handshake_autoprobe_fragsize(int dns_fd)
|
|||
}
|
||||
if (!running) {
|
||||
fprintf(stderr, "\n");
|
||||
warnx("stopped while autodetecting fragment size (Try probing manually with -m)");
|
||||
warnx("stopped while autodetecting fragment size (Try setting manually with -m)");
|
||||
return 0;
|
||||
}
|
||||
if (range == 0) {
|
||||
if (max_fragsize <= 2) {
|
||||
/* Tried all the way down to 2 and found no good size */
|
||||
fprintf(stderr, "\n");
|
||||
warnx("found no accepted fragment size. (Try probing manually with -m)");
|
||||
warnx("found no accepted fragment size. (Try forcing with -m, or try other -T or -O options)");
|
||||
return 0;
|
||||
}
|
||||
fprintf(stderr, "will use %d\n", max_fragsize);
|
||||
return max_fragsize;
|
||||
/* data header adds 2 bytes */
|
||||
fprintf(stderr, "will use %d-2=%d\n", max_fragsize, max_fragsize - 2);
|
||||
|
||||
if (do_qtype != T_NULL && downenc == ' ')
|
||||
fprintf(stderr, "(Maybe other -O options will increase throughput)\n");
|
||||
|
||||
return max_fragsize - 2;
|
||||
}
|
||||
|
||||
static void
|
||||
|
|
@ -1084,6 +1358,10 @@ client_handshake(int dns_fd, int raw_mode, int autodetect_frag_size, int fragsiz
|
|||
handshake_switch_codec(dns_fd);
|
||||
}
|
||||
|
||||
if (downenc != ' ') {
|
||||
handshake_switch_downenc(dns_fd);
|
||||
}
|
||||
|
||||
if (autodetect_frag_size) {
|
||||
fragsize = handshake_autoprobe_fragsize(dns_fd);
|
||||
if (!fragsize) {
|
||||
|
|
|
|||
|
|
@ -29,7 +29,7 @@ get_resolvconf_addr()
|
|||
rv = NULL;
|
||||
|
||||
if ((fp = fopen("/etc/resolv.conf", "r")) == NULL)
|
||||
err(1, "/etc/resolve.conf");
|
||||
err(1, "/etc/resolv.conf");
|
||||
|
||||
while (feof(fp) == 0) {
|
||||
fgets(buf, sizeof(buf), fp);
|
||||
|
|
|
|||
Loading…
Reference in New Issue