Mercurial > dropbear
changeset 1016:257f7d5fca97
piggyback data on acks when making connections on linux
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Fri, 13 Feb 2015 22:49:15 +0800 |
parents | cb7b510b4dd2 |
children | cb148f8d3d22 |
files | cli-main.c dbutil.c |
diffstat | 2 files changed, 40 insertions(+), 9 deletions(-) [+] |
line wrap: on
line diff
--- a/cli-main.c Fri Feb 13 21:45:15 2015 +0800 +++ b/cli-main.c Fri Feb 13 22:49:15 2015 +0800 @@ -73,7 +73,7 @@ #endif { int sock = connect_remote(cli_opts.remotehost, cli_opts.remoteport, - 0, &error); + 1, &error); sock_in = sock_out = sock; }
--- a/dbutil.c Fri Feb 13 21:45:15 2015 +0800 +++ b/dbutil.c Fri Feb 13 22:49:15 2015 +0800 @@ -150,18 +150,31 @@ #ifdef DEBUG_TRACE + +static double time_since_start() +{ + static double start_time = -1; + double nowf; + struct timeval tv; + gettimeofday(&tv, NULL); + nowf = tv.tv_sec + (tv.tv_usec / 1000000.0); + if (start_time < 0) + { + start_time = nowf; + return 0; + } + return nowf - start_time; +} + void dropbear_trace(const char* format, ...) { va_list param; - struct timeval tv; if (!debug_trace) { return; } - gettimeofday(&tv, NULL); - va_start(param, format); - fprintf(stderr, "TRACE (%d) %d.%d: ", getpid(), (int)tv.tv_sec, (int)tv.tv_usec); + fprintf(stderr, "TRACE (%d) %f: ", getpid(), time_since_start()); vfprintf(stderr, format, param); fprintf(stderr, "\n"); va_end(param); @@ -170,7 +183,6 @@ void dropbear_trace2(const char* format, ...) { static int trace_env = -1; va_list param; - struct timeval tv; if (trace_env == -1) { trace_env = getenv("DROPBEAR_TRACE2") ? 1 : 0; @@ -180,10 +192,8 @@ return; } - gettimeofday(&tv, NULL); - va_start(param, format); - fprintf(stderr, "TRACE2 (%d) %d.%d: ", getpid(), (int)tv.tv_sec, (int)tv.tv_usec); + fprintf(stderr, "TRACE2 (%d) %f: ", getpid(), time_since_start()); vfprintf(stderr, format, param); fprintf(stderr, "\n"); va_end(param); @@ -390,6 +400,23 @@ } #endif +#if defined(__linux__) && defined(TCP_DEFER_ACCEPT) +static void set_piggyback_ack(int sock) { + /* Undocumented Linux feature - set TCP_DEFER_ACCEPT and data will be piggybacked + on the 3rd packet (ack) of the TCP handshake. Saves a IP packet. + http://thread.gmane.org/gmane.linux.network/224627/focus=224727 + "Piggyback the final ACK of the three way TCP connection establishment with the data" */ + int val = 1; + /* No error checking, this is opportunistic */ + int err = setsockopt(sock, IPPROTO_TCP, TCP_DEFER_ACCEPT, (void*)&val, sizeof(val)); + if (err) + { + DEBUG_TRACE(("Failed setsockopt TCP_DEFER_ACCEPT: %s", strerror(errno))) + } +} +#endif + + /* Connect via TCP to a host. Connection will try ipv4 or ipv6, will * return immediately if nonblocking is set. On failure, if errstring * wasn't null, it will be a newly malloced error message */ @@ -437,6 +464,10 @@ if (nonblocking) { setnonblocking(sock); + +#if defined(__linux__) && defined(TCP_DEFER_ACCEPT) + set_piggyback_ack(sock); +#endif } if (connect(sock, res->ai_addr, res->ai_addrlen) < 0) {