From 9e6ae4ff1dfc0054068f2c3a7024bfa4391ed3c8 Mon Sep 17 00:00:00 2001 From: Erik Ekman Date: Sun, 15 Feb 2009 20:07:30 +0000 Subject: [PATCH] Split handshake() function into smaller functions --- src/iodine.c | 240 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 161 insertions(+), 79 deletions(-) diff --git a/src/iodine.c b/src/iodine.c index c4c40fe..641cd91 100644 --- a/src/iodine.c +++ b/src/iodine.c @@ -498,22 +498,17 @@ send_codec_switch(int fd, int userid, int bits) strncat(buf, topdomain, 512 - strlen(buf)); send_query(fd, buf); } - + static int -handshake(int dns_fd) +handshake_version(int dns_fd, int *seed) { struct timeval tv; - uint32_t payload; - char server[65]; - char client[65]; - char login[16]; char in[4096]; fd_set fds; - int read; - int mtu; - int seed; + uint32_t payload; int i; int r; + int read; for (i = 0; running && i < 5; i++) { tv.tv_sec = i + 1; @@ -544,11 +539,11 @@ handshake(int dns_fd) ((in[7] & 0xff))); if (strncmp("VACK", in, 4) == 0) { - seed = payload; + *seed = payload; userid = in[8]; printf("Version ok, both using protocol v 0x%08x. You are user #%d\n", VERSION, userid); - goto perform_login; + return 0; } else if (strncmp("VNAK", in, 4) == 0) { warnx("You use protocol v 0x%08x, server uses v 0x%08x. Giving up", VERSION, payload); @@ -563,10 +558,24 @@ handshake(int dns_fd) printf("Retrying version check...\n"); } - errx(1, "couldn't connect to server"); - /* NOTREACHED */ - -perform_login: + warnx("couldn't connect to server"); + return 1; +} + +static int +handshake_login(int dns_fd, int seed) +{ + struct timeval tv; + char in[4096]; + char login[16]; + char server[65]; + char client[65]; + int mtu; + fd_set fds; + int i; + int r; + int read; + login_calculate(login, 16, password, seed); for (i=0; running && i<5 ;i++) { @@ -600,7 +609,7 @@ perform_login: client[64] = 0; if (tun_setip(client, netmask) == 0 && tun_setmtu(mtu) == 0) { - goto perform_case_check; + return 0; } else { warnx("Received handshake with bad data"); } @@ -614,8 +623,18 @@ perform_login: } warnx("couldn't login to server"); return 1; +} + +static void +handshake_case_check(int dns_fd) +{ + struct timeval tv; + char in[4096]; + fd_set fds; + int i; + int r; + int read; -perform_case_check: case_preserved = 0; for (i=0; running && i<5 ;i++) { tv.tv_sec = i + 1; @@ -635,7 +654,7 @@ perform_case_check: if (in[0] == 'z' || in[0] == 'Z') { if (read < (27 * 2)) { printf("Received short case check reply. Will use base32 encoder\n"); - goto switch_codec; + return; } else { int k; @@ -647,14 +666,14 @@ perform_case_check: case_preserved = 0; } } - goto switch_codec; + return; } } else { printf("Received bad case check reply\n"); } } else { printf("Got error on case check, will use base32\n"); - goto switch_codec; + return; } } @@ -662,9 +681,17 @@ perform_case_check: } printf("No reply on case check, continuing\n"); -switch_codec: - if (!case_preserved) - goto autodetect_max_fragsize; +} + +static void +handshake_switch_codec(int dns_fd) +{ + struct timeval tv; + char in[4096]; + fd_set fds; + int i; + int r; + int read; dataenc = get_base64_encoder(); printf("Switching to %s codec\n", dataenc->name); @@ -699,76 +726,99 @@ switch_codec: } in[read] = 0; /* zero terminate */ printf("Server switched to codec %s\n", in); - goto autodetect_max_fragsize; + return; } } printf("Retrying codec switch...\n"); } printf("No reply from server on codec switch. "); + codec_revert: printf("Falling back to base32\n"); dataenc = get_base32_encoder(); -autodetect_max_fragsize: - if (autodetect_frag_size) { - int proposed_fragsize = 768; - int range = 768; - max_downstream_frag_size = 0; - printf("Autoprobing max downstream fragment size... (skip with -m fragsize)\n"); - while (running && range > 0 && (range >= 8 || !max_downstream_frag_size)) { - for (i=0; running && i<3 ;i++) { - tv.tv_sec = 1; - tv.tv_usec = 0; - send_fragsize_probe(dns_fd, proposed_fragsize); +} - FD_ZERO(&fds); - FD_SET(dns_fd, &fds); +static int +handshake_autoprobe_fragsize(int dns_fd) +{ + struct timeval tv; + char in[4096]; + fd_set fds; + int i; + int r; + int read; + int proposed_fragsize = 768; + int range = 768; - r = select(dns_fd + 1, &fds, NULL, NULL, &tv); + max_downstream_frag_size = 0; + printf("Autoprobing max downstream fragment size... (skip with -m fragsize)\n"); + while (running && range > 0 && (range >= 8 || !max_downstream_frag_size)) { + for (i=0; running && i<3 ;i++) { + tv.tv_sec = 1; + tv.tv_usec = 0; + send_fragsize_probe(dns_fd, proposed_fragsize); - if(r > 0) { - read = read_dns(dns_fd, 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) { - printf("%d ok.. ", acked_fragsize); - fflush(stdout); - max_downstream_frag_size = acked_fragsize; - range >>= 1; - proposed_fragsize += range; - continue; - } else { - goto badlen; - } - } - if (strncmp("BADIP", in, 5) == 0) { - printf("got BADIP.. "); + FD_ZERO(&fds); + FD_SET(dns_fd, &fds); + + r = select(dns_fd + 1, &fds, NULL, NULL, &tv); + + if(r > 0) { + read = read_dns(dns_fd, 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) { + printf("%d ok.. ", acked_fragsize); fflush(stdout); + max_downstream_frag_size = acked_fragsize; + range >>= 1; + proposed_fragsize += range; + continue; + } else { + goto badlen; } } + if (strncmp("BADIP", in, 5) == 0) { + printf("got BADIP.. "); + fflush(stdout); + } } } + } badlen: - printf("%d not ok.. ", proposed_fragsize); - fflush(stdout); - range >>= 1; - proposed_fragsize -= range; - } - if (!running) { - printf("\n"); - warnx("stopped while autodetecting fragment size (Try probing manually with -m)"); - return 1; - } - if (range == 0) { - /* Tried all the way down to 2 and found no good size */ - printf("\n"); - warnx("found no accepted fragment size. (Try probing manually with -m)"); - return 1; - } - printf("will use %d\n", max_downstream_frag_size); + printf("%d not ok.. ", proposed_fragsize); + fflush(stdout); + range >>= 1; + proposed_fragsize -= range; } + if (!running) { + printf("\n"); + warnx("stopped while autodetecting fragment size (Try probing manually with -m)"); + return 1; + } + if (range == 0) { + /* Tried all the way down to 2 and found no good size */ + printf("\n"); + warnx("found no accepted fragment size. (Try probing manually with -m)"); + return 1; + } + printf("will use %d\n", max_downstream_frag_size); + return 0; +} + +static void +handshake_set_fragsize(int dns_fd) +{ + struct timeval tv; + char in[4096]; + fd_set fds; + int i; + int r; + int read; + printf("Setting downstream fragment size to max %d...\n", max_downstream_frag_size); for (i=0; running && i<5 ;i++) { tv.tv_sec = i + 1; @@ -789,20 +839,52 @@ badlen: if (strncmp("BADFRAG", in, 7) == 0) { printf("Server rejected fragsize. Keeping default."); - goto done; + return; } else if (strncmp("BADIP", in, 5) == 0) { printf("Server rejected sender IP address.\n"); - goto done; + return; } accepted_fragsize = ((in[0] & 0xff) << 8) | (in[1] & 0xff); - goto done; + return; } } printf("Retrying set fragsize...\n"); } printf("No reply from server when setting fragsize. Keeping default.\n"); -done: +} + +static int +handshake(int dns_fd) +{ + int seed; + int r; + + r = handshake_version(dns_fd, &seed); + if (r) { + return r; + } + + r = handshake_login(dns_fd, seed); + if (r) { + return r; + } + + handshake_case_check(dns_fd); + + if (case_preserved) { + handshake_switch_codec(dns_fd); + } + + if (autodetect_frag_size) { + r = handshake_autoprobe_fragsize(dns_fd); + if (r) { + return r; + } + } + + handshake_set_fragsize(dns_fd); + return 0; }