add -4 and -6 options to use either IPv4 or IPv6

doc/mscp.1.in

@@ -6,7 +6,7 @@ mscp \- copy files over multiple SSH connections
 .SH SYNOPSIS
 
 .B mscp
-.RB [ \-vqDpHdNh ]
+.RB [ \-46vqDpHdNh ]
 [\c
 .BI \-n \ NR_CONNECTIONS\c
 ]
@@ -150,6 +150,14 @@ Specifies the buffer size for I/O and transfer over SFTP. The default
 value is 16384. Note that the SSH specification restricts buffer size
 delivered over SSH. Changing this value is not recommended at present.
 
+.TP
+.B \-4
+Uses IPv4 addresses only.
+
+.TP
+.B \-6
+Uses IPv6 addresses only.
+
 .TP
 .B \-v
 Increments the verbose output level.

doc/mscp.rst

@@ -2,7 +2,7 @@
 MSCP
 ====
 
-:Date:   v0.1.3-22-g9608400
+:Date:   v0.1.3-23-ga9c59f7
 
 NAME
 ====
@@ -12,7 +12,7 @@ mscp - copy files over multiple SSH connections
 SYNOPSIS
 ========
 
-**mscp** [**-vqDpHdNh**] [ **-n**\ *NR_CONNECTIONS* ] [
+**mscp** [**-46vqDpHdNh**] [ **-n**\ *NR_CONNECTIONS* ] [
 **-m**\ *COREMASK* ] [ **-u**\ *MAX_STARTUPS* ] [ **-I**\ *INTERVAL* ] [
 **-s**\ *MIN_CHUNK_SIZE* ] [ **-S**\ *MAX_CHUNK_SIZE* ] [
 **-a**\ *NR_AHEAD* ] [ **-b**\ *BUF_SIZE* ] [ **-l**\ *LOGIN_NAME* ] [
@@ -87,6 +87,12 @@ OPTIONS
    delivered over SSH. Changing this value is not recommended at
    present.
 
+**-4**
+   Uses IPv4 addresses only.
+
+**-6**
+   Uses IPv6 addresses only.
+
 **-v**
    Increments the verbose output level.
 

include/mscp.h

@@ -58,6 +58,7 @@ struct mscp_ssh_opts {
 	/* ssh options */
 	char	*login_name;	/** ssh username */
 	char	*port;		/** ssh port */
+	int	ai_family;	/** address family */
 	char	*config;	/** path to ssh_config, default ~/.ssh/config*/
 	char	*identity;	/** path to private key */
 	char	*cipher;	/** cipher spec */

patch/libssh-0.10.6-2-g6f1b1e76.patch

@@ -37,10 +37,18 @@ index 1fce7b76..b64d1455 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 669a0a96..b6a93ac7 100644
+index 669a0a96..da5b4099 100644
 --- a/include/libssh/libssh.h
 +++ b/include/libssh/libssh.h
-@@ -402,6 +402,7 @@ enum ssh_options_e {
+@@ -368,6 +368,7 @@ enum ssh_options_e {
+   SSH_OPTIONS_HOST,
+   SSH_OPTIONS_PORT,
+   SSH_OPTIONS_PORT_STR,
++  SSH_OPTIONS_AI_FAMILY,
+   SSH_OPTIONS_FD,
+   SSH_OPTIONS_USER,
+   SSH_OPTIONS_SSH_DIR,
+@@ -402,6 +403,7 @@ enum ssh_options_e {
    SSH_OPTIONS_GSSAPI_AUTH,
    SSH_OPTIONS_GLOBAL_KNOWNHOSTS,
    SSH_OPTIONS_NODELAY,
@@ -48,7 +56,7 @@ index 669a0a96..b6a93ac7 100644
    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);
+@@ -833,6 +835,7 @@ 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);
@@ -56,7 +64,7 @@ index 669a0a96..b6a93ac7 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 +845,8 @@ LIBSSH_API void *ssh_buffer_get(ssh_buffer buffer);
+@@ -843,6 +846,8 @@ 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);
  
@@ -66,10 +74,18 @@ index 669a0a96..b6a93ac7 100644
  #include "libssh/legacy.h"
  #endif
 diff --git a/include/libssh/session.h b/include/libssh/session.h
-index 97936195..e4a7f80c 100644
+index 97936195..e4fc4fce 100644
 --- a/include/libssh/session.h
 +++ b/include/libssh/session.h
-@@ -258,6 +258,7 @@ struct ssh_session_struct {
+@@ -249,6 +249,7 @@ struct ssh_session_struct {
+         unsigned long timeout; /* seconds */
+         unsigned long timeout_usec;
+         uint16_t port;
++        int  ai_family;
+         socket_t fd;
+         int StrictHostKeyChecking;
+         char compressionlevel;
+@@ -258,6 +259,7 @@ struct ssh_session_struct {
          int flags;
          int exp_flags;
          int nodelay;
@@ -204,9 +220,27 @@ index 8991e006..e0414801 100644
   * @brief Ensure the buffer has at least a certain preallocated size.
   *
 diff --git a/src/connect.c b/src/connect.c
-index 15cae644..e7520f40 100644
+index 15cae644..02ef43b4 100644
 --- a/src/connect.c
 +++ b/src/connect.c
+@@ -114,7 +114,7 @@ static int ssh_connect_socket_close(socket_t s)
+ #endif
+ }
+ 
+-static int getai(const char *host, int port, struct addrinfo **ai)
++static int getai(const char *host, int port, int ai_family, struct addrinfo **ai)
+ {
+     const char *service = NULL;
+     struct addrinfo hints;
+@@ -123,7 +123,7 @@ static int getai(const char *host, int port, struct addrinfo **ai)
+     ZERO_STRUCT(hints);
+ 
+     hints.ai_protocol = IPPROTO_TCP;
+-    hints.ai_family = PF_UNSPEC;
++    hints.ai_family = ai_family > 0 ? ai_family : PF_UNSPEC;
+     hints.ai_socktype = SOCK_STREAM;
+ 
+     if (port == 0) {
 @@ -156,6 +156,20 @@ static int set_tcp_nodelay(socket_t socket)
                        sizeof(opt));
  }
@@ -228,6 +262,24 @@ index 15cae644..e7520f40 100644
  /**
   * @internal
   *
+@@ -173,7 +187,7 @@ socket_t ssh_connect_host_nonblocking(ssh_session session, const char *host,
+     struct addrinfo *ai = NULL;
+     struct addrinfo *itr = NULL;
+ 
+-    rc = getai(host, port, &ai);
++    rc = getai(host, port, session->opts.ai_family, &ai);
+     if (rc != 0) {
+         ssh_set_error(session, SSH_FATAL,
+                       "Failed to resolve hostname %s (%s)",
+@@ -199,7 +213,7 @@ socket_t ssh_connect_host_nonblocking(ssh_session session, const char *host,
+ 
+             SSH_LOG(SSH_LOG_PACKET, "Resolving %s", bind_addr);
+ 
+-            rc = getai(bind_addr, 0, &bind_ai);
++            rc = getai(bind_addr, 0, session->opts.ai_family, &bind_ai);
+             if (rc != 0) {
+                 ssh_set_error(session, SSH_FATAL,
+                               "Failed to resolve bind address %s (%s)",
 @@ -256,6 +270,18 @@ socket_t ssh_connect_host_nonblocking(ssh_session session, const char *host,
              }
          }
@@ -248,7 +300,7 @@ index 15cae644..e7520f40 100644
          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 b3ecffe1..fb966fa1 100644
+index b3ecffe1..8de24ed6 100644
 --- a/src/options.c
 +++ b/src/options.c
 @@ -217,6 +217,7 @@ int ssh_options_copy(ssh_session src, ssh_session *dest)
@@ -259,7 +311,17 @@ index b3ecffe1..fb966fa1 100644
      new->opts.config_processed      = src->opts.config_processed;
      new->common.log_verbosity       = src->common.log_verbosity;
      new->common.callbacks           = src->common.callbacks;
-@@ -458,6 +459,10 @@ int ssh_options_set_algo(ssh_session session,
+@@ -268,6 +269,9 @@ int ssh_options_set_algo(ssh_session session,
+  *              - SSH_OPTIONS_PORT_STR:
+  *                The port to connect to (const char *).
+  *
++ *              - SSH_OPTIONS_AI_FAMILY:
++ *                The address family for connecting (int *).
++ *
+  *              - SSH_OPTIONS_FD:
+  *                The file descriptor to use (socket_t).\n
+  *                \n
+@@ -458,6 +462,10 @@ int ssh_options_set_algo(ssh_session session,
   *                Set it to disable Nagle's Algorithm (TCP_NODELAY) on the
   *                session socket. (int, 0=false)
   *
@@ -270,7 +332,29 @@ index b3ecffe1..fb966fa1 100644
   *              - SSH_OPTIONS_PROCESS_CONFIG
   *                Set it to false to disable automatic processing of per-user
   *                and system-wide OpenSSH configuration files. LibSSH
-@@ -1017,6 +1022,20 @@ int ssh_options_set(ssh_session session, enum ssh_options_e type,
+@@ -571,6 +579,21 @@ int ssh_options_set(ssh_session session, enum ssh_options_e type,
+                 session->opts.port = i & 0xffffU;
+             }
+             break;
++        case SSH_OPTIONS_AI_FAMILY:
++            if (value == NULL) {
++                session->opts.ai_family = 0;
++                ssh_set_error_invalid(session);
++                return -1;
++            } else {
++                int *x = (int *) value;
++                if (*x < 0) {
++		    session->opts.ai_family = 0;
++                    ssh_set_error_invalid(session);
++                    return -1;
++                }
++                session->opts.ai_family = *x;
++            }
++            break;
+         case SSH_OPTIONS_FD:
+             if (value == NULL) {
+                 session->opts.fd = SSH_INVALID_SOCKET;
+@@ -1017,6 +1040,20 @@ int ssh_options_set(ssh_session session, enum ssh_options_e type,
                  session->opts.nodelay = (*x & 0xff) > 0 ? 1 : 0;
              }
              break;
@@ -292,10 +376,14 @@ index b3ecffe1..fb966fa1 100644
              if (value == NULL) {
                  ssh_set_error_invalid(session);
 diff --git a/src/session.c b/src/session.c
-index 8c509699..88602b6a 100644
+index 8c509699..307388e5 100644
 --- a/src/session.c
 +++ b/src/session.c
-@@ -108,6 +108,7 @@ ssh_session ssh_new(void)
+@@ -105,9 +105,11 @@ ssh_session ssh_new(void)
+     /* OPTIONS */
+     session->opts.StrictHostKeyChecking = 1;
+     session->opts.port = 22;
++    session->opts.ai_family = 0;
      session->opts.fd = -1;
      session->opts.compressionlevel = 7;
      session->opts.nodelay = 0;

scripts/test-in-container.sh

@@ -15,6 +15,8 @@ if [ ! -e /var/run/sshd.pid ]; then
 fi
 
 ssh-keyscan localhost >> ${HOME}/.ssh/known_hosts
+ssh-keyscan 127.0.0.1 >> ${HOME}/.ssh/known_hosts
+ssh-keyscan ::1 >> ${HOME}/.ssh/known_hosts
 
 # Run test
 python3 -m pytest ../test -v

src/main.c

@@ -9,6 +9,8 @@
 #include <sys/time.h>
 #include <sys/ioctl.h>
 #include <poll.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
 #include <pthread.h>
 
 #include <mscp.h>
@@ -20,12 +22,12 @@
 
 void usage(bool print_help)
 {
-	printf("mscp " MSCP_BUILD_VERSION ": copy files over multiple ssh connections\n"
+	printf("mscp " MSCP_BUILD_VERSION ": copy files over multiple SSH connections\n"
 	       "\n"
-	       "Usage: mscp [vqDpHdNh] [-n nr_conns] [-m coremask]\n"
+	       "Usage: mscp [-46vqDpHdNh] [-n nr_conns] [-m coremask]\n"
 	       "            [-u max_startups] [-I interval]\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"
+	       "            [-l login_name] [-P port] [-F ssh_config] [-i identity_file]\n"
 	       "            [-c cipher_spec] [-M hmac_spec] [-C compress] [-g congestion]\n"
 	       "            source ... target\n"
 	       "\n");
@@ -45,6 +47,8 @@ void usage(bool print_help)
 	       "    -a NR_AHEAD        number of inflight SFTP commands (default: 32)\n"
 	       "    -b BUF_SZ          buffer size for i/o and transfer\n"
 	       "\n"
+	       "    -4                 use IPv4\n"
+	       "    -6                 use IPv6\n"
 	       "    -v                 increment verbose output level\n"
 	       "    -q                 disable output\n"
 	       "    -D                 dry run. check copy destinations with -vvv\n"
@@ -263,8 +267,8 @@ int main(int argc, char **argv)
 	memset(&o, 0, sizeof(o));
 	o.severity = MSCP_SEVERITY_WARN;
 
-	while ((ch = getopt(argc, argv, "n:m:u:I:s:S:a:b:vqDrl:P:i:F:c:M:C:g:pHdNh")) !=
+#define mscpopts "n:m:u:I:s:S:a:b:46vqDrl:P:i:F:c:M:C:g:pHdNh"
-	       -1) {
+	while ((ch = getopt(argc, argv, mscpopts)) != -1) {
 		switch (ch) {
 		case 'n':
 			o.nr_threads = atoi(optarg);
@@ -294,6 +298,12 @@ int main(int argc, char **argv)
 		case 'b':
 			o.buf_sz = atoi(optarg);
 			break;
+		case '4':
+			s.ai_family = AF_INET;
+			break;
+		case '6':
+			s.ai_family = AF_INET6;
+			break;
 		case 'v':
 			o.severity++;
 			break;

src/ssh.c

@@ -27,6 +27,12 @@ static int ssh_set_opts(ssh_session ssh, struct mscp_ssh_opts *opts)
 		return -1;
 	}
 
+	if (opts->ai_family &&
+	    ssh_options_set(ssh, SSH_OPTIONS_AI_FAMILY, &opts->ai_family) < 0) {
+		priv_set_errv("failed to set address family");
+		return -1;
+	}
+
 	if (opts->identity &&
 	    ssh_options_set(ssh, SSH_OPTIONS_IDENTITY, opts->identity) < 0) {
 		priv_set_errv("failed to set identity");

test/test_e2e.py

@@ -324,6 +324,38 @@ def test_set_port(mscp, src_prefix, dst_prefix, src, dst):
     run2ng([mscp, "-H", "-vvv", "-P", 21, src_prefix + src.path, dst_prefix + dst.path])
     src.cleanup()
 
+def test_v4only(mscp):
+    src = File("src", size = 1024).make()
+    dst = File("dst")
+    dst_prefix = "localhost:{}/".format(os.getcwd())
+    run2ok([mscp, "-H", "-vvv", "-4", src.path, dst_prefix + dst.path])
+    assert check_same_md5sum(src, dst)
+    src.cleanup()
+    dst.cleanup()
+
+def test_v6only(mscp):
+    src = File("src", size = 1024).make()
+    dst = File("dst")
+    dst_prefix = "localhost:{}/".format(os.getcwd())
+    run2ok([mscp, "-H", "-vvv", "-6", src.path, dst_prefix + dst.path])
+    assert check_same_md5sum(src, dst)
+    src.cleanup()
+    dst.cleanup()
+
+def test_v4_to_v6_should_fail(mscp):
+    src = File("src", size = 1024).make()
+    dst = File("dst")
+    dst_prefix = "[::1]:{}/".format(os.getcwd())
+    run2ng([mscp, "-H", "-vvv", "-4", src.path, dst_prefix + dst.path])
+    src.cleanup()
+
+def test_v6_to_v4_should_fail(mscp):
+    src = File("src", size = 1024).make()
+    dst = File("dst")
+    dst_prefix = "127.0.0.1:{}/".format(os.getcwd())
+    run2ng([mscp, "-H", "-vvv", "-6", src.path, dst_prefix + dst.path])
+    src.cleanup()
+
 @pytest.mark.parametrize("src_prefix, dst_prefix", param_remote_prefix)
 def test_set_conn_interval(mscp, src_prefix, dst_prefix):
     srcs = []
@@ -442,3 +474,4 @@ def test_specify_invalid_password_via_env(mscp):
     run2ng([mscp, "-H", "-vvv", "-l", "test",
             src.path, "localhost:" + dst.path], env = env)
     src.cleanup()
+