add -g option to specify TCP cc algorithm

This commit introduce SSH_OPTIONS_CCALGO option to the libssh patch
and add -g CONGESTION option to mscp.

7 files changed, 191 insertions, 7 deletions

diff --git a/include/mscp.h b/include/mscp.h
index 7062c48..35af518 100644
--- a/include/mscp.h
+++ b/include/mscp.h
@@ -56,6 +56,7 @@ struct mscp_opts {
 #define MSCP_SSH_MAX_CIPHER_STR		32
 #define MSCP_SSH_MAX_HMAC_STR		32
 #define MSCP_SSH_MAX_COMP_STR		32 /* yes, no, zlib, zlib@openssh.com, none */
+#define MSCP_SSH_MAX_CCALGO_STR		16
 #define MSCP_SSH_MAX_PASSWORD		128
 #define MSCP_SSH_MAX_PASSPHRASE		128
 
@@ -72,6 +73,7 @@ struct mscp_ssh_opts {
 	char	cipher[MSCP_SSH_MAX_CIPHER_STR];	/** cipher spec */
 	char	hmac[MSCP_SSH_MAX_HMAC_STR];		/** hmacp spec */
 	char	compress[MSCP_SSH_MAX_COMP_STR];	/** yes, no, zlib@openssh.com */
+	char	ccalgo[MSCP_SSH_MAX_CCALGO_STR];	/** TCP cc algorithm */
 
 	char	password[MSCP_SSH_MAX_PASSWORD];	/** password auth passowrd */
 	char	passphrase[MSCP_SSH_MAX_PASSPHRASE];	/** passphrase for private key */
diff --git a/patch/libssh-0.10.4.patch b/patch/libssh-0.10.4.patch
index a8a9628..432cad0 100644
--- a/patch/libssh-0.10.4.patch
+++ b/patch/libssh-0.10.4.patch
@@ -1,3 +1,28 @@
+diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
+index 7103f303..c64eb39d 100644
+--- a/ConfigureChecks.cmake
++++ b/ConfigureChecks.cmake
+@@ -258,6 +258,7 @@ if (UNIX)
+     check_library_exists(util forkpty "" HAVE_LIBUTIL)
+     check_function_exists(cfmakeraw HAVE_CFMAKERAW)
+     check_function_exists(__strtoull HAVE___STRTOULL)
++    check_symbol_exists(TCP_CONGESTION "netinet/tcp.h" HAVE_TCP_CONGESTION)
+ endif (UNIX)
+ 
+ set(LIBSSH_REQUIRED_LIBRARIES ${_REQUIRED_LIBRARIES} CACHE INTERNAL "libssh required system libraries")
+diff --git a/config.h.cmake b/config.h.cmake
+index 1357615b..1e915ead 100644
+--- a/config.h.cmake
++++ b/config.h.cmake
+@@ -237,6 +237,8 @@
+ 
+ #cmakedefine HAVE_GCC_BOUNDED_ATTRIBUTE 1
+ 
++#cmakedefine HAVE_TCP_CONGESTION 1
++
+ /* Define to 1 if you want to enable GSSAPI */
+ #cmakedefine WITH_GSSAPI 1
+ 
 diff --git a/include/libssh/buffer.h b/include/libssh/buffer.h
 index a55a1b40..e34e075c 100644
 --- a/include/libssh/buffer.h
@@ -12,10 +37,18 @@ index a55a1b40..e34e075c 100644
  int ssh_buffer_validate_length(struct ssh_buffer_struct *buffer, size_t len);
  
 diff --git a/include/libssh/libssh.h b/include/libssh/libssh.h
-index 7857a77b..3eef7a16 100644
+index 7857a77b..6b4d481c 100644
 --- a/include/libssh/libssh.h
 +++ b/include/libssh/libssh.h
-@@ -833,6 +833,7 @@ LIBSSH_API const char* ssh_get_hmac_in(ssh_session session);
+@@ -402,6 +402,7 @@ enum ssh_options_e {
+   SSH_OPTIONS_GSSAPI_AUTH,
+   SSH_OPTIONS_GLOBAL_KNOWNHOSTS,
+   SSH_OPTIONS_NODELAY,
++  SSH_OPTIONS_CCALGO,
+   SSH_OPTIONS_PUBLICKEY_ACCEPTED_TYPES,
+   SSH_OPTIONS_PROCESS_CONFIG,
+   SSH_OPTIONS_REKEY_DATA,
+@@ -833,6 +834,7 @@ LIBSSH_API const char* ssh_get_hmac_in(ssh_session session);
  LIBSSH_API const char* ssh_get_hmac_out(ssh_session session);
  
  LIBSSH_API ssh_buffer ssh_buffer_new(void);
@@ -23,7 +56,7 @@ index 7857a77b..3eef7a16 100644
  LIBSSH_API void ssh_buffer_free(ssh_buffer buffer);
  #define SSH_BUFFER_FREE(x) \
      do { if ((x) != NULL) { ssh_buffer_free(x); x = NULL; } } while(0)
-@@ -843,6 +844,8 @@ LIBSSH_API void *ssh_buffer_get(ssh_buffer buffer);
+@@ -843,6 +845,8 @@ LIBSSH_API void *ssh_buffer_get(ssh_buffer buffer);
  LIBSSH_API uint32_t ssh_buffer_get_len(ssh_buffer buffer);
  LIBSSH_API int ssh_session_set_disconnect_message(ssh_session session, const char *message);
  
@@ -32,6 +65,18 @@ index 7857a77b..3eef7a16 100644
  #ifndef LIBSSH_LEGACY_0_4
  #include "libssh/legacy.h"
  #endif
+diff --git a/include/libssh/session.h b/include/libssh/session.h
+index d3e5787c..15183d1b 100644
+--- a/include/libssh/session.h
++++ b/include/libssh/session.h
+@@ -232,6 +232,7 @@ struct ssh_session_struct {
+         int gss_delegate_creds;
+         int flags;
+         int nodelay;
++        char *ccalgo;
+         bool config_processed;
+         uint8_t options_seen[SOC_MAX];
+         uint64_t rekey_data;
 diff --git a/include/libssh/sftp.h b/include/libssh/sftp.h
 index c855df8a..0fcdb9b8 100644
 --- a/include/libssh/sftp.h
@@ -158,6 +203,106 @@ index e0068015..cc0caf35 100644
  /**
   * @brief Ensure the buffer has at least a certain preallocated size.
   *
+diff --git a/src/connect.c b/src/connect.c
+index 57e37e63..c02397d5 100644
+--- a/src/connect.c
++++ b/src/connect.c
+@@ -156,6 +156,20 @@ static int set_tcp_nodelay(socket_t socket)
+                       sizeof(opt));
+ }
+ 
++static int set_tcp_ccalgo(socket_t socket, const char *ccalgo)
++{
++#ifdef HAVE_TCP_CONGESTION
++	return setsockopt(socket,
++			  IPPROTO_TCP,
++			  TCP_CONGESTION,
++			  (void *)ccalgo,
++			  strlen(ccalgo));
++#else
++	errno = ENOTSUP;
++	return -1;
++#endif
++}
++
+ /**
+  * @internal
+  *
+@@ -256,6 +270,18 @@ socket_t ssh_connect_host_nonblocking(ssh_session session, const char *host,
+             }
+         }
+ 
++        if (session->opts.ccalgo) {
++	     rc = set_tcp_ccalgo(s, session->opts.ccalgo);
++	     if (rc < 0) {
++		 ssh_set_error(session, SSH_FATAL,
++			       "Failed to set TCP_CONGESTION on socket: %s",
++			       ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));
++		 ssh_connect_socket_close(s);
++		 s = -1;
++		 continue;
++	     }
++	}
++
+         errno = 0;
+         rc = connect(s, itr->ai_addr, itr->ai_addrlen);
+         if (rc == -1 && (errno != 0) && (errno != EINPROGRESS)) {
+diff --git a/src/options.c b/src/options.c
+index 49aaefa2..9f7360c3 100644
+--- a/src/options.c
++++ b/src/options.c
+@@ -210,6 +210,7 @@ int ssh_options_copy(ssh_session src, ssh_session *dest)
+     new->opts.gss_delegate_creds    = src->opts.gss_delegate_creds;
+     new->opts.flags                 = src->opts.flags;
+     new->opts.nodelay               = src->opts.nodelay;
++    new->opts.ccalgo                = src->opts.ccalgo;
+     new->opts.config_processed      = src->opts.config_processed;
+     new->common.log_verbosity       = src->common.log_verbosity;
+     new->common.callbacks           = src->common.callbacks;
+@@ -450,6 +451,10 @@ int ssh_options_set_algo(ssh_session session,
+  *                Set it to disable Nagle's Algorithm (TCP_NODELAY) on the
+  *                session socket. (int, 0=false)
+  *
++ *              - SSH_OPTIONS_CCALGO
++ *                Set it to specify TCP congestion control algorithm on the
++ *                session socket (Linux only). (int, 0=false)
++ *
+  *              - SSH_OPTIONS_PROCESS_CONFIG
+  *                Set it to false to disable automatic processing of per-user
+  *                and system-wide OpenSSH configuration files. LibSSH
+@@ -1013,6 +1018,20 @@ int ssh_options_set(ssh_session session, enum ssh_options_e type,
+                 session->opts.nodelay = (*x & 0xff) > 0 ? 1 : 0;
+             }
+             break;
++	case SSH_OPTIONS_CCALGO:
++            v = value;
++            if (v == NULL || v[0] == '\0') {
++                ssh_set_error_invalid(session);
++                return -1;
++            } else {
++                SAFE_FREE(session->opts.ccalgo);
++                session->opts.ccalgo = strdup(v);
++                if (session->opts.ccalgo == NULL) {
++                    ssh_set_error_oom(session);
++                    return -1;
++                }
++            }
++            break;
+         case SSH_OPTIONS_PROCESS_CONFIG:
+             if (value == NULL) {
+                 ssh_set_error_invalid(session);
+diff --git a/src/session.c b/src/session.c
+index 6025c133..6b197526 100644
+--- a/src/session.c
++++ b/src/session.c
+@@ -108,6 +108,7 @@ ssh_session ssh_new(void)
+     session->opts.fd = -1;
+     session->opts.compressionlevel = 7;
+     session->opts.nodelay = 0;
++    session->opts.ccalgo = NULL;
+ 
+     session->opts.flags = SSH_OPT_FLAG_PASSWORD_AUTH |
+                           SSH_OPT_FLAG_PUBKEY_AUTH |
 diff --git a/src/sftp.c b/src/sftp.c
 index e01012a8..702623a0 100644
 --- a/src/sftp.c
diff --git a/src/main.c b/src/main.c
index cbd2574..8a229dd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -21,7 +21,8 @@ void usage(bool print_help) {
 	       "Usage: mscp [vqDHdNh] [-n nr_conns] [-m coremask] [-u max_startups]\n"
 	       "            [-s min_chunk_sz] [-S max_chunk_sz] [-a nr_ahead] [-b buf_sz]\n"
 	       "            [-l login_name] [-p port] [-F ssh_config] [-i identity_file]\n"
-	       "            [-c cipher_spec] [-M hmac_spec] [-C compress] source ... target\n"
+	       "            [-c cipher_spec] [-M hmac_spec] [-C compress] [-g congestion]\n"
+	       "            source ... target\n"
 	       "\n");
 
 	if (!print_help)
@@ -51,6 +52,7 @@ void usage(bool print_help) {
 	       "    -M HMAC            hmac spec\n"
 	       "    -C COMPRESS        enable compression: "
 	       "yes, no, zlib, zlib@openssh.com\n"
+	       "    -g CONGESTION      specify TCP congestion control algorithm\n"
 	       "    -H                 disable hostkey check\n"
 	       "    -d                 increment ssh debug output level\n"
 	       "    -N                 enable Nagle's algorithm (default disabled)\n"
@@ -202,7 +204,8 @@ int main(int argc, char **argv)
 	memset(&o, 0, sizeof(o));
 	o.severity = MSCP_SEVERITY_WARN;
 
-	while ((ch = getopt(argc, argv, "n:m:u:s:S:a:b:vqDrl:p:i:F:c:M:C:HdNh")) != -1) {
+	while ((ch = getopt(argc, argv,
+			    "n:m:u:s:S:a:b:vqDrl:p:i:F:c:M:C:g:HdNh")) != -1) {
 		switch (ch) {
 		case 'n':
 			o.nr_threads = atoi(optarg);
@@ -287,6 +290,13 @@ int main(int argc, char **argv)
 			}
 			strncpy(s.compress, optarg, MSCP_SSH_MAX_COMP_STR);
 			break;
+		case 'g':
+			if (strlen(optarg) > MSCP_SSH_MAX_CCALGO_STR - 1) {
+				fprintf(stderr, "long ccalgo string: %s\n", optarg);
+				return -1;
+			}
+			strncpy(s.ccalgo, optarg, MSCP_SSH_MAX_CCALGO_STR);
+			break;
 		case 'H':
 			s.no_hostkey_check = true;
 			break;
diff --git a/src/pymscp.c b/src/pymscp.c
index c36c662..6861ad8 100644
--- a/src/pymscp.c
+++ b/src/pymscp.c
@@ -109,6 +109,7 @@ static PyObject *wrap_mscp_init(PyObject *self, PyObject *args, PyObject *kw)
 		"cipher",	/* const char * */
 		"hmac",		/* const char * */
 		"compress",	/* const char * */
+		"ccalgo",       /* const char * */
 		"password",	/* const char * */
 		"passphrase",	/* const char * */
 
@@ -117,10 +118,10 @@ static PyObject *wrap_mscp_init(PyObject *self, PyObject *args, PyObject *kw)
 		"enable_nagle",		/* bool */
 		NULL,
 	};
-	const char *fmt = "si" "|" "ii" "kkk" "s" "iii" "ssss" "sssss" "ipp";
+	const char *fmt = "si" "|" "ii" "kkk" "s" "iii" "ssss" "ssssss" "ipp";
 	char *coremask = NULL;
 	char *login_name = NULL, *port = NULL, *config = NULL, *identity = NULL;
-	char *cipher = NULL, *hmac = NULL, *compress = NULL;
+	char *cipher = NULL, *hmac = NULL, *compress = NULL, *ccalgo = NULL;
 	char *password = NULL, *passphrase = NULL;
 
 	struct instance *i;
@@ -154,6 +155,7 @@ static PyObject *wrap_mscp_init(PyObject *self, PyObject *args, PyObject *kw)
 					  &cipher,
 					  &hmac,
 					  &compress,
+					  &ccalgo,
 					  &password,
 					  &passphrase,
 					  &i->so.debug_level,
@@ -179,6 +181,8 @@ static PyObject *wrap_mscp_init(PyObject *self, PyObject *args, PyObject *kw)
 		strncpy(i->so.hmac, hmac, MSCP_SSH_MAX_HMAC_STR - 1);
 	if (compress)
 		strncpy(i->so.compress, compress, MSCP_SSH_MAX_COMP_STR - 1);
+	if (ccalgo)
+		strncpy(i->so.ccalgo, ccalgo, MSCP_SSH_MAX_CCALGO_STR - 1);
 	if (password)
 		strncpy(i->so.password, password, MSCP_SSH_MAX_PASSWORD - 1);
 	if (passphrase)
diff --git a/src/ssh.c b/src/ssh.c
index 29f9623..eceb71c 100644
--- a/src/ssh.c
+++ b/src/ssh.c
@@ -64,6 +64,12 @@ static int ssh_set_opts(ssh_session ssh, struct mscp_ssh_opts *opts)
 		return -1;
 	}
 
+	if (is_specified(opts->ccalgo) &&
+	    ssh_options_set(ssh, SSH_OPTIONS_CCALGO, opts->ccalgo) < 0) {
+		mscp_set_error("failed to set cclago");
+		return -1;
+	}
+
 	/* if NOT specified to enable Nagle's algorithm, disable it (set TCP_NODELAY) */
 	if (!opts->enable_nagle) {
 		int v = 1;
diff --git a/test/test_e2e.py b/test/test_e2e.py
index 108ae71..c46141b 100644
--- a/test/test_e2e.py
+++ b/test/test_e2e.py
@@ -3,6 +3,7 @@
 test_e2e.py: End-to-End test for mscp executable.
 """
 
+import platform
 import pytest
 import os
 
@@ -268,6 +269,21 @@ def test_compression(mscp, src_prefix, dst_prefix, compress):
     src.cleanup()
     dst.cleanup()
 
+@pytest.mark.parametrize("src_prefix, dst_prefix", param_remote_prefix)
+def test_ccalgo(mscp, src_prefix, dst_prefix):
+    src = File("src", size = 1024 * 1024).make()
+    dst = File("dst").make()
+    if platform.system() == "Darwin":
+        # Darwin does not support TCP_CONGESTION
+        algo = "cubic"
+        run = run2ng
+    elif platform.system() == "Linux":
+        # Linux supports TCP_CONGESTION
+        with open("/proc/sys/net/ipv4/tcp_allowed_congestion_control", r) as f:
+            algo = f.read().strip().split().pop()
+        run = run2ok
+    run([mscp, "-H", "-vvv", "-g", algo, src_prefix + src.path, dst_prefix + "dst"])
+
 
 testhost = "mscptestlocalhost"
 testhost_prefix = "{}:{}/".format(testhost, os.getcwd()) # use current dir
diff --git a/test/test_python.py b/test/test_python.py
index a6b2787..22d778a 100644
--- a/test/test_python.py
+++ b/test/test_python.py
@@ -121,6 +121,7 @@ param_invalid_kwargs = [
     { "cipher": "invalid" },
     { "hmac": "invalid"},
     { "compress": "invalid"},
+    { "ccalgo": "invalid"},
 ]
 
 @pytest.mark.parametrize("kw", param_invalid_kwargs)