From d74939d323643edf15680b54aa5ae1d59042102b Mon Sep 17 00:00:00 2001 From: Erik Ekman Date: Fri, 24 Jul 2020 20:18:07 +0200 Subject: [PATCH] Add send_handshake_query helper function Convert send_downenctest to use it. Remove unused data/len args from send_downenctest. --- src/client.c | 47 +++++++++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 16 deletions(-) diff --git a/src/client.c b/src/client.c index 13539a0..0d7864b 100644 --- a/src/client.c +++ b/src/client.c @@ -1255,6 +1255,28 @@ send_version(int fd, uint32_t version) send_packet(fd, 'v', data, sizeof(data)); } +/* Add lower 15 bits of rand seed as base32, + * followed by a dot and the tunnel domain and send */ +static void +send_handshake_query(int fd, char *prefix) +{ + char buf[300]; + char cmc_dot[5]; + + cmc_dot[0] = b32_5to8((rand_seed >> 10) & 0x1f); + cmc_dot[1] = b32_5to8((rand_seed >> 5) & 0x1f); + cmc_dot[2] = b32_5to8((rand_seed) & 0x1f); + cmc_dot[3] = '.'; + cmc_dot[4] = 0; + rand_seed++; + + buf[0] = 0; + strncat(buf, prefix, 60); /* 63 - space for 3 CMC bytes */ + strcat(buf, cmc_dot); + strncat(buf, topdomain, sizeof(buf) - strlen(buf)); + send_query(fd, buf); +} + static void send_ip_request(int fd, int userid) { @@ -1297,21 +1319,14 @@ send_upenctest(int fd, const char *s) } static void -send_downenctest(int fd, char downenc, int variant, char *s, int slen) -/* Note: content/handling of s is not defined yet. */ +send_downenctest(int fd, char downenc, int variant) { - char buf[512] = "y_____."; + char prefix[4] = "y__"; + prefix[1] = tolower(downenc); + prefix[2] = b32_5to8(variant); - buf[1] = tolower(downenc); - buf[2] = b32_5to8(variant); - - buf[3] = b32_5to8((rand_seed >> 10) & 0x1f); - buf[4] = b32_5to8((rand_seed >> 5) & 0x1f); - buf[5] = b32_5to8((rand_seed) & 0x1f); - rand_seed++; - - strncat(buf, topdomain, 512 - strlen(buf)); - send_query(fd, buf); + /* Use send_query directly if we ever send more data here. */ + send_handshake_query(fd, prefix); } static void @@ -1746,7 +1761,7 @@ handshake_downenctest(int dns_fd, char trycodec) for (i = 0; running && i < 3; i++) { - send_downenctest(dns_fd, trycodec, 1, NULL, 0); + send_downenctest(dns_fd, trycodec, 1); read = handshake_waitdns(dns_fd, in, sizeof(in), 'y', 'Y', i+1); @@ -1846,7 +1861,7 @@ handshake_qtypetest(int dns_fd, int timeout) byte values can be returned, which is needed for NULL/PRIVATE to work. */ - send_downenctest(dns_fd, trycodec, 1, NULL, 0); + send_downenctest(dns_fd, trycodec, 1); read = handshake_waitdns(dns_fd, in, sizeof(in), 'y', 'Y', timeout); @@ -1972,7 +1987,7 @@ handshake_edns0_check(int dns_fd) for (i = 0; running && i < 3; i++) { - send_downenctest(dns_fd, trycodec, 1, NULL, 0); + send_downenctest(dns_fd, trycodec, 1); read = handshake_waitdns(dns_fd, in, sizeof(in), 'y', 'Y', i+1);