thodg/libgit2

diff --git a/include/git2/transport.h b/include/git2/transport.h
index 5e99683..9b9ecc5 100644
--- a/include/git2/transport.h
+++ b/include/git2/transport.h
@@ -319,6 +319,17 @@ GIT_EXTERN(int) git_smart_subtransport_git(
 	git_smart_subtransport **out,
 	git_transport* owner);
 
+/**
+ * Create an instance of the ssh subtransport.
+ *
+ * @param out The newly created subtransport
+ * @param owner The smart transport to own this subtransport
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_smart_subtransport_ssh(
+	git_smart_subtransport **out,
+	git_transport* owner);
+
 /*
  *** End interface for subtransports for the smart transport ***
  */
diff --git a/src/transport.c b/src/transport.c
index adb6d53..7b7a5aa 100644
--- a/src/transport.c
+++ b/src/transport.c
@@ -23,14 +23,16 @@ static transport_definition dummy_transport_definition = { NULL, 1, git_transpor
 
 static git_smart_subtransport_definition http_subtransport_definition = { git_smart_subtransport_http, 1 };
 static git_smart_subtransport_definition git_subtransport_definition = { git_smart_subtransport_git, 0 };
+static git_smart_subtransport_definition ssh_subtransport_definition = { git_smart_subtransport_ssh, 0 };
 
 static transport_definition transports[] = {
 	{"git://", 1, git_transport_smart, &git_subtransport_definition},
 	{"http://", 1, git_transport_smart, &http_subtransport_definition},
 	{"https://", 1, git_transport_smart, &http_subtransport_definition},
 	{"file://", 1, git_transport_local, NULL},
-	{"git+ssh://", 1, git_transport_dummy, NULL},
-	{"ssh+git://", 1, git_transport_dummy, NULL},
+	{"git+ssh://", 1, git_transport_smart, &git_smart_subtransport_ssh},
+	{"ssh+git://", 1, git_transport_smart, &git_smart_subtransport_ssh},
+	{"git@", 1, git_transport_smart, &git_smart_subtransport_ssh},
 	{NULL, 0, 0}
 };
 
diff --git a/src/transports/ssh.c b/src/transports/ssh.c
new file mode 100644
index 0000000..a7f21f5
--- /dev/null
+++ b/src/transports/ssh.c
@@ -0,0 +1,356 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "git2.h"
+#include "buffer.h"
+#include "netops.h"
+
+#include <libssh2.h>
+
+#define OWNING_SUBTRANSPORT(s) ((ssh_subtransport *)(s)->parent.subtransport)
+
+static const char prefix_git_ssh[] = "git+ssh://";
+static const char prefix_ssh_git[] = "ssh+git://";
+static const char prefix_git[] = "git@";
+static const char cmd_uploadpack[] = "git-upload-pack";
+static const char cmd_receivepack[] = "git-receive-pack";
+
+typedef struct {
+	git_smart_subtransport_stream parent;
+	gitno_socket socket;
+	const char *cmd;
+	char *url;
+	unsigned sent_command : 1;
+} ssh_stream;
+
+typedef struct {
+	git_smart_subtransport parent;
+	git_transport *owner;
+	git_stream *current_stream;
+} ssh_subtransport;
+
+/*
+ * Create a git protocol request.
+ *
+ * For example: 0035git-upload-pack /libgit2/libgit2\0host=github.com\0
+ */
+static int gen_proto(git_buf *request, const char *cmd, const char *url)
+{
+	char *delim, *repo;
+	char host[] = "host=";
+	size_t len;
+	
+	delim = strchr(url, '/');
+	if (delim == NULL) {
+		giterr_set(GITERR_NET, "Malformed URL");
+		return -1;
+	}
+	
+	repo = delim;
+	
+	delim = strchr(url, ':');
+	if (delim == NULL)
+		delim = strchr(url, '/');
+	
+	len = 4 + strlen(cmd) + 1 + strlen(repo) + 1 + strlen(host) + (delim - url) + 1;
+	
+	git_buf_grow(request, len);
+	git_buf_printf(request, "%04x%s %s%c%s",
+				   (unsigned int)(len & 0x0FFFF), cmd, repo, 0, host);
+	git_buf_put(request, url, delim - url);
+	git_buf_putc(request, '\0');
+	
+	if (git_buf_oom(request))
+		return -1;
+	
+	return 0;
+}
+
+static int send_command(git_stream *s)
+{
+	int error;
+	git_buf request = GIT_BUF_INIT;
+	
+	error = gen_proto(&request, s->cmd, s->url);
+	if (error < 0)
+		goto cleanup;
+	
+	/* It looks like negative values are errors here, and positive values
+	 * are the number of bytes sent. */
+	error = gitno_send(&s->socket, request.ptr, request.size, 0);
+	
+	if (error >= 0)
+		s->sent_command = 1;
+	
+cleanup:
+	git_buf_free(&request);
+	return error;
+}
+
+static int git_stream_read(
+						   git_smart_subtransport_stream *stream,
+						   char *buffer,
+						   size_t buf_size,
+						   size_t *bytes_read)
+{
+	git_stream *s = (git_stream *)stream;
+	gitno_buffer buf;
+	
+	*bytes_read = 0;
+	
+	if (!s->sent_command && send_command(s) < 0)
+		return -1;
+	
+	gitno_buffer_setup(&s->socket, &buf, buffer, buf_size);
+	
+	if (gitno_recv(&buf) < 0)
+		return -1;
+	
+	*bytes_read = buf.offset;
+	
+	return 0;
+}
+
+static int git_stream_write(
+							git_smart_subtransport_stream *stream,
+							const char *buffer,
+							size_t len)
+{
+	git_stream *s = (git_stream *)stream;
+	
+	if (!s->sent_command && send_command(s) < 0)
+		return -1;
+	
+	return gitno_send(&s->socket, buffer, len, 0);
+}
+
+static void git_stream_free(git_smart_subtransport_stream *stream)
+{
+	git_stream *s = (git_stream *)stream;
+	ssh_subtransport *t = OWNING_SUBTRANSPORT(s);
+	int ret;
+	
+	GIT_UNUSED(ret);
+	
+	t->current_stream = NULL;
+	
+	if (s->socket.socket) {
+		ret = gitno_close(&s->socket);
+		assert(!ret);
+	}
+	
+	git__free(s->url);
+	git__free(s);
+}
+
+static int git_stream_alloc(
+							ssh_subtransport *t,
+							const char *url,
+							const char *cmd,
+							git_smart_subtransport_stream **stream)
+{
+	git_stream *s;
+	
+	if (!stream)
+		return -1;
+	
+	s = git__calloc(sizeof(git_stream), 1);
+	GITERR_CHECK_ALLOC(s);
+	
+	s->parent.subtransport = &t->parent;
+	s->parent.read = git_stream_read;
+	s->parent.write = git_stream_write;
+	s->parent.free = git_stream_free;
+	
+	s->cmd = cmd;
+	s->url = git__strdup(url);
+	
+	if (!s->url) {
+		git__free(s);
+		return -1;
+	}
+	
+	*stream = &s->parent;
+	return 0;
+}
+
+static int _git_uploadpack_ls(
+							  ssh_subtransport *t,
+							  const char *url,
+							  git_smart_subtransport_stream **stream)
+{
+	char *host, *port, *user=NULL, *pass=NULL;
+	git_stream *s;
+	
+	*stream = NULL;
+	
+	if (!git__prefixcmp(url, prefix_git))
+		url += strlen(prefix_git);
+	
+	if (git_stream_alloc(t, url, cmd_uploadpack, stream) < 0)
+		return -1;
+	
+	s = (git_stream *)*stream;
+	
+	if (gitno_extract_url_parts(&host, &port, &user, &pass, url, GIT_DEFAULT_PORT) < 0)
+		goto on_error;
+	
+	if (gitno_connect(&s->socket, host, port, 0) < 0)
+		goto on_error;
+	
+	t->current_stream = s;
+	git__free(host);
+	git__free(port);
+	git__free(user);
+	git__free(pass);
+	return 0;
+	
+on_error:
+	if (*stream)
+		git_stream_free(*stream);
+	
+	git__free(host);
+	git__free(port);
+	return -1;
+}
+
+static int _git_uploadpack(
+						   ssh_subtransport *t,
+						   const char *url,
+						   git_smart_subtransport_stream **stream)
+{
+	GIT_UNUSED(url);
+	
+	if (t->current_stream) {
+		*stream = &t->current_stream->parent;
+		return 0;
+	}
+	
+	giterr_set(GITERR_NET, "Must call UPLOADPACK_LS before UPLOADPACK");
+	return -1;
+}
+
+static int _git_receivepack_ls(
+							   ssh_subtransport *t,
+							   const char *url,
+							   git_smart_subtransport_stream **stream)
+{
+	char *host, *port, *user=NULL, *pass=NULL;
+	git_stream *s;
+	
+	*stream = NULL;
+	
+	if (!git__prefixcmp(url, prefix_git))
+		url += strlen(prefix_git);
+	
+	if (git_stream_alloc(t, url, cmd_receivepack, stream) < 0)
+		return -1;
+	
+	s = (git_stream *)*stream;
+	
+	if (gitno_extract_url_parts(&host, &port, &user, &pass, url, GIT_DEFAULT_PORT) < 0)
+		goto on_error;
+	
+	if (gitno_connect(&s->socket, host, port, 0) < 0)
+		goto on_error;
+	
+	t->current_stream = s;
+	git__free(host);
+	git__free(port);
+	git__free(user);
+	git__free(pass);
+	return 0;
+	
+on_error:
+	if (*stream)
+		git_stream_free(*stream);
+	
+	git__free(host);
+	git__free(port);
+	return -1;
+}
+
+static int _git_receivepack(
+							ssh_subtransport *t,
+							const char *url,
+							git_smart_subtransport_stream **stream)
+{
+	GIT_UNUSED(url);
+	
+	if (t->current_stream) {
+		*stream = &t->current_stream->parent;
+		return 0;
+	}
+	
+	giterr_set(GITERR_NET, "Must call RECEIVEPACK_LS before RECEIVEPACK");
+	return -1;
+}
+
+static int _git_action(
+					   git_smart_subtransport_stream **stream,
+					   git_smart_subtransport *subtransport,
+					   const char *url,
+					   git_smart_service_t action)
+{
+	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+	
+	switch (action) {
+		case GIT_SERVICE_UPLOADPACK_LS:
+			return _git_uploadpack_ls(t, url, stream);
+			
+		case GIT_SERVICE_UPLOADPACK:
+			return _git_uploadpack(t, url, stream);
+			
+		case GIT_SERVICE_RECEIVEPACK_LS:
+			return _git_receivepack_ls(t, url, stream);
+			
+		case GIT_SERVICE_RECEIVEPACK:
+			return _git_receivepack(t, url, stream);
+	}
+	
+	*stream = NULL;
+	return -1;
+}
+
+static int _git_close(git_smart_subtransport *subtransport)
+{
+	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+	
+	assert(!t->current_stream);
+	
+	GIT_UNUSED(t);
+	
+	return 0;
+}
+
+static void _git_free(git_smart_subtransport *subtransport)
+{
+	ssh_subtransport *t = (ssh_subtransport *) subtransport;
+	
+	assert(!t->current_stream);
+	
+	git__free(t);
+}
+
+int git_smart_subtransport_git(git_smart_subtransport **out, git_transport *owner)
+{
+	ssh_subtransport *t;
+	
+	if (!out)
+		return -1;
+	
+	t = git__calloc(sizeof(ssh_subtransport), 1);
+	GITERR_CHECK_ALLOC(t);
+	
+	t->owner = owner;
+	t->parent.action = _git_action;
+	t->parent.close = _git_close;
+	t->parent.free = _git_free;
+	
+	*out = (git_smart_subtransport *) t;
+	return 0;
+}