start to impliment mscp as a library

this commit starts to refactor file.h|c to path.h|c and
add mscp.c|h. not completed yet.

9 files changed, 788 insertions, 3 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 17837d0..6cad232 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -49,6 +49,22 @@ target_compile_definitions(mscp PUBLIC _VERSION="${PROJECT_VERSION}")
 install(TARGETS mscp RUNTIME DESTINATION bin)
 
 
+# libmscp
+add_library(mscp-shared SHARED src/mscp.c src/ssh.c src/path.c)
+target_include_directories(mscp-shared PRIVATE ${MSCP_INCLUDE_DIRS})
+target_link_directories(mscp-shared PRIVATE ${MSCP_LINK_DIRS})
+target_link_libraries(mscp-shared PRIVATE ${MSCP_LINK_LIBS})
+target_compile_options(mscp-shared PRIVATE ${MSCP_COMPILE_OPTS})
+set_target_properties(mscp-shared
+	PROPERTIES
+	OUTPUT_NAME	mscp)
+
+# test executable
+add_executable(test-mscp src/test.c src/ssh.c src/path.c)
+target_include_directories(test-mscp PRIVATE ${MSCP_INCLUDE_DIRS})
+target_link_directories(test-mscp PRIVATE ${MSCP_LINK_DIRS})
+target_link_libraries(test-mscp PRIVATE ${MSCP_LINK_LIBS})
+target_compile_options(test-mscp PRIVATE ${MSCP_COMPILE_OPTS})
 
 # Test
 add_test(NAME	pytest
diff --git a/src/list.h b/src/list.h
index 6c7e79f..b2cfc76 100644
--- a/src/list.h
+++ b/src/list.h
@@ -208,6 +208,32 @@ static inline void list_splice(struct list_head *list, struct list_head *head)
 		__list_splice(list, head);
 }
 
+static inline void __list_splice_tail(struct list_head *list,
+				      struct list_head *head)
+{
+	struct list_head *first = list->next;
+	struct list_head *last = list->prev;
+	struct list_head *at = head->prev;
+
+	first->prev = at;
+	at->next = first;
+
+	last->next = head;
+	at->prev = last;
+}
+
+/**
+ * list_splice_tail - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice_tail(struct list_head *list, struct list_head *head)
+{
+	if (!list_empty(list))
+		__list_splice_tail(list, head);
+}
+
+
 /**
  * list_splice_init - join two lists and reinitialise the emptied list.
  * @list: the new list to add.
diff --git a/src/mscp.c b/src/mscp.c
new file mode 100644
index 0000000..d1d8fa8
--- /dev/null
+++ b/src/mscp.c
@@ -0,0 +1,190 @@
+#include <stdbool.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <math.h>
+#include <pthread.h>
+
+#include <list.h>       
+#include <util.h>       
+#include <ssh.h>                
+#include <path.h>
+#include <pprint.h>             
+#include <atomic.h>             
+#include <platform.h>
+#include <mscp.h>
+
+struct mscp {
+	const char		*remote;	/* remote host (and uername) */
+	struct mscp_opts	*opts;
+	struct ssh_opts		ssh_opts;
+
+	sftp_session		first;		/* first sftp session */
+
+	char 			dst_path[PATH_MAX];
+	struct list_head	src_list;
+	struct list_head	path_list;
+	struct list_head	chunk_list;
+	lock			chunk_lock;
+
+	struct mscp_thread	*threads;
+};
+
+struct src {
+	struct list_head list;
+	char *path;
+};
+
+#define DEFAULT_MIN_CHUNK_SZ    (64 << 20)      /* 64MB */
+#define DEFAULT_NR_AHEAD        32
+#define DEFAULT_BUF_SZ          16384
+
+struct mscp *mscp_init(const char *remote_host, struct mscp_opts *opts)
+{
+	struct mscp *m;
+
+	m = malloc(sizeof(*m));
+	if (!m) {
+		pr_err("failed to allocate memory: %s\n", strerrno());
+		return NULL;
+	}
+
+	memset(m, 0, sizeof(*m));
+	INIT_LIST_HEAD(&m->src_list);
+	INIT_LIST_HEAD(&m->path_list);
+	INIT_LIST_HEAD(&m->chunk_list);
+	lock_init(&m->chunk_lock);
+	m->remote = strdup(remote_host);
+	if (!m->remote) {
+		pr_err("failed to allocate memory: %s\n", strerrno());
+		free(m);
+		return NULL;
+	}
+
+	m->opts = opts;
+	m->ssh_opts.login_name		= opts->ssh_login_name;
+	m->ssh_opts.port		= opts->ssh_port;
+	m->ssh_opts.identity		= opts->ssh_identity;
+	m->ssh_opts.cipher		= opts->ssh_cipher_spec;
+	m->ssh_opts.hmac		= opts->ssh_hmac_spec;
+	m->ssh_opts.compress		= opts->ssh_compress_level;
+	m->ssh_opts.debuglevel		= opts->ssh_debug_level;
+	m->ssh_opts.no_hostkey_check	= opts->ssh_no_hostkey_check;
+	m->ssh_opts.nodelay		= opts->ssh_disable_tcp_nodely;
+
+	m->first = ssh_init_sftp_session(m->remote, &m->ssh_opts);
+	if (!m->first) {
+		free(m);
+		return NULL;
+	}
+
+	return m;
+}
+
+int mscp_add_src_path(struct mscp *m, const char *src_path)
+{
+	struct src *s;
+
+	s = malloc(sizeof(*s));
+	if (!s) {
+		pr_err("failed to allocate memory: %s\n", strerrno());
+		return -1;
+	}
+
+	memset(s, 0, sizeof(*s));
+	s->path = strdup(src_path);
+	if (!s->path) {
+		pr_err("failed to allocate memory: %s\n", strerrno());
+		free(s);
+		return -1;
+	}
+
+	list_add_tail(&s->list, &m->src_list);
+	return 0;
+}
+
+static void mscp_free_src_list(struct mscp *m)
+{
+	struct src *s, *n;
+
+	list_for_each_entry_safe(s, n, &m->src_list, list) {
+		free(s->path);
+		list_del(&s->list);
+		free(s);
+	}
+}
+
+int mscp_set_dst_path(struct mscp *m, const char *dst_path)
+{
+	if (strlen(dst_path) + 1 >= PATH_MAX) {
+		pr_err("too long dst path: %s\n", dst_path);
+		return -1;
+	}
+
+	strncpy(m->dst_path, dst_path, PATH_MAX);
+	return 0;
+}
+
+int mscp_prepare(struct mscp *m)
+{
+	sftp_session src_sftp = NULL, dst_sftp = NULL;
+	bool src_path_is_dir, dst_path_is_dir;
+	struct list_head tmp;
+	struct src *s;
+	mstat ss, ds;
+	
+	switch (m->opts->direct) {
+	case MSCP_DIRECT_L2R:
+		src_sftp = NULL;
+		dst_sftp = m->first;
+		break;
+	case MSCP_DIRECT_R2L:
+		src_sftp = m->first;
+		dst_sftp = NULL;
+		break;
+	default:
+		pr_err("invalid mscp direction: %d\n", m->opts->direct);
+		return -1;
+	}
+
+	if (mscp_stat(m->dst_path, &ds, dst_sftp) == 0) {
+		if (mstat_is_dir(ds))
+			dst_path_is_dir = true;
+		mscp_stat_free(ds);
+	} else
+		dst_path_is_dir = false;
+
+	/* walk a src_path recusively, and resolve path->dst_path for each src */
+	list_for_each_entry(s, &m->src_list, list) {
+		if (mscp_stat(s->path, &ss, src_sftp) < 0) {
+			pr_err("stat: %s\n", mscp_stat_strerror(src_sftp));
+			return -1;
+		}
+		src_path_is_dir = mstat_is_dir(ss);
+		mscp_stat_free(ss);
+
+		INIT_LIST_HEAD(&tmp);
+		if (walk_src_path(src_sftp, s->path, &tmp) < 0)
+			return -1;
+		
+		if (resolve_dst_path(src_sftp, s->path, m->dst_path, &tmp,
+				     src_path_is_dir, dst_path_is_dir) < 0)
+			return -1;
+
+		list_splice_tail(&tmp, m->path_list.prev);
+	}
+
+	if (prepare_chunk(&m->path_list, &m->chunk_list, m->opts->nr_threads,
+			  m->opts->max_chunk_sz, m->opts->min_chunk_sz) < 0)
+		return -1;
+
+	mscp_free_src_list(m);
+
+	return 0;
+}
+
+int mscp_start(struct mscp *m)
+{
+	return 0;
+}
diff --git a/src/mscp.h b/src/mscp.h
new file mode 100644
index 0000000..beb48dd
--- /dev/null
+++ b/src/mscp.h
@@ -0,0 +1,43 @@
+#ifndef _MSCP_H_
+#define _MSCP_H_
+
+#include <stdbool.h>
+
+#define MSCP_DIRECT_L2R	1
+#define MSCP_DIRECT_R2L	2
+
+struct mscp_opts {
+	/* mscp options */
+	int	direct;	/* MSCP_DIRECT_ */
+
+	int	nr_threads;
+	int	nr_ahead;
+	size_t	min_chunk_sz;
+	size_t	max_chunk_sz;
+	size_t	buf_sz;
+
+	int	verbose_level;
+	bool	quiet;
+	bool	dryrun;
+
+	/* ssh options */
+	char	ssh_login_name[64];
+	char	ssh_port[32];
+	char	ssh_identity[PATH_MAX];
+	char	ssh_cipher_spec[64];
+	char	ssh_hmac_spec[32];
+	int	ssh_debug_level;
+	int	ssh_compress_level;
+	bool	ssh_no_hostkey_check;
+	bool	ssh_disable_tcp_nodely;
+};
+
+struct mscp;
+
+struct mscp *mscp_init(const char *remote_host, struct mscp_opts *opts);
+int mscp_add_src_path(struct mscp *m, const char *src_path);
+int mscp_set_dst_path(struct mscp *m, const char *dst_path);
+int mscp_prepare(struct mscp *m);
+int mscp_start(struct mscp *m);
+
+#endif /* _MSCP_H_ */
diff --git a/src/path.c b/src/path.c
new file mode 100644
index 0000000..2951dfd
--- /dev/null
+++ b/src/path.c
@@ -0,0 +1,250 @@
+#include <string.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <libgen.h>
+
+#include <ssh.h>
+#include <util.h>
+#include <list.h>
+#include <atomic.h>
+#include <path.h>
+
+
+
+static int append_path(sftp_session sftp, const char *path, mstat s,
+		       struct list_head *path_list)
+{
+	struct path *p;
+
+	if (!(p = malloc(sizeof(*p)))) {
+		pr_err("failed to allocate memory: %s\n", strerrno());
+		return -1;
+	}
+
+	memset(p, 0, sizeof(*p));
+	INIT_LIST_HEAD(&p->list);
+	strncpy(p->path, path, PATH_MAX - 1);
+	p->size = mstat_size(s);
+	p->mode = mstat_mode(s);
+	p->state = FILE_STATE_INIT;
+	lock_init(&p->lock);
+	list_add_tail(&p->list, path_list);
+
+	return 0;
+}
+
+static bool check_path_should_skip(const char *path)
+{               
+        int len = strlen(path);
+        if ((len == 1 && strncmp(path, ".", 1) == 0) ||
+            (len == 2 && strncmp(path, "..", 2) == 0)) {
+                return true;
+        }
+        return false; 
+}
+
+static int walk_path_recursive(sftp_session sftp, const char *path,
+			       struct list_head *path_list)
+{
+	char next_path[PATH_MAX];
+	mdirent *e;
+	mdir *d;
+	mstat s;
+	int ret;
+
+	if (mscp_stat(path, &s, sftp) < 0)
+		return -1;
+
+	if (mstat_is_regular(s)) {
+		/* this path is regular file. it is to be copied */
+		ret = append_path(sftp, path, s, path_list);
+		mscp_stat_free(s);
+		return ret;
+	}
+
+	if (!mstat_is_dir(s)) {
+		/* not regular file and not directory, skip it. */
+		mscp_stat_free(s);
+		return 0; 
+	}
+
+	mscp_stat_free(s);
+
+
+	/* ok, this path is directory. walk it. */
+	if (!(d = mscp_opendir(path, sftp)))
+		return -1;
+	
+	for (e = mscp_readdir(d); !mdirent_is_null(e); e = mscp_readdir(d)) {
+		if (check_path_should_skip(mdirent_name(e)))
+			continue;
+		
+		if (strlen(path) + 1 + strlen(mdirent_name(e)) > PATH_MAX) {
+			pr_err("too long path: %s/%s\n", path, mdirent_name(e));
+			return -1;
+		}
+		snprintf(next_path, sizeof(next_path), "%s/%s", path, mdirent_name(e));
+		ret = walk_path_recursive(sftp, next_path, path_list);
+		if (ret < 0)
+			return ret;
+	}
+
+	mscp_closedir(d);
+
+	return 0;
+}
+
+int walk_src_path(sftp_session sftp, const char *src_path, struct list_head *path_list)
+{
+	return walk_path_recursive(sftp, src_path, path_list);
+}
+
+static int src2dst_path(const char *src_path, const char *src_file_path,
+			const char *dst_path, char *dst_file_path, size_t len,
+			bool src_path_is_dir, bool dst_path_is_dir)
+{
+	char copy[PATH_MAX];
+	char *prefix;
+	int offset;
+
+	strncpy(copy, src_path, PATH_MAX - 1);
+	prefix = dirname(copy);
+	if (!prefix) {
+		pr_err("dirname: %s\n", strerrno());
+		return -1;
+	}
+	if (strlen(prefix) == 1 && prefix[0] == '.')
+		offset = 0;
+	else
+		offset = strlen(prefix) + 1;
+
+
+	/* both are file */
+	if (!src_path_is_dir && !dst_path_is_dir)
+		strncpy(dst_file_path, dst_path, len);
+
+	/* src is file, and dst is dir */
+	if (!src_path_is_dir && dst_path_is_dir)
+		snprintf(dst_file_path, len, "%s/%s", dst_path, src_path + offset);
+
+	/* both are directory */
+	if (src_path_is_dir && dst_path_is_dir)
+		snprintf(dst_file_path, len, "%s/%s", dst_path, src_file_path + offset);
+
+	/* dst path does not exist. change dir name to dst_path */
+	if (src_path_is_dir && !dst_path_is_dir)
+		snprintf(dst_file_path, len, "%s/%s",
+			 dst_path, src_file_path + strlen(src_path) + 1);
+
+	return 0;
+}
+
+int resolve_dst_path(sftp_session sftp, const char *src_path, const char *dst_path,
+		     struct list_head *path_list, bool src_is_dir, bool dst_is_dir)
+{
+	struct path *p;
+
+	list_for_each_entry(p, path_list, list) {
+		if (src2dst_path(src_path, p->path, dst_path, p->dst_path, PATH_MAX,
+				 src_is_dir, dst_is_dir) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+void path_dump(struct list_head *path_list)
+{
+	struct path *p;
+
+	list_for_each_entry(p, path_list, list) {
+		printf("src: %s %lu-byte\n", p->path, p->size);
+		printf("dst: %s\n", p->dst_path);
+	}
+}
+	
+/* chunk preparation */
+
+static struct chunk *alloc_chunk(struct path *p)
+{
+        struct chunk *c;
+
+        if (!(c = malloc(sizeof(*c)))) {
+                pr_err("%s\n", strerrno());
+                return NULL;
+        }
+        memset(c, 0, sizeof(*c));
+
+        c->p = p;
+        c->off = 0;
+        c->len = 0;
+        refcnt_inc(&p->refcnt);
+        return c;
+}
+
+static int get_page_mask(void)
+{
+        long page_sz = sysconf(_SC_PAGESIZE);
+        size_t page_mask = 0;
+        int n;
+
+        for (n = 0; page_sz > 0; page_sz >>= 1, n++) {
+                page_mask <<= 1;
+                page_mask |= 1;
+        }
+
+        return page_mask >> 1;
+}
+
+int prepare_chunk(struct list_head *path_list, struct list_head *chunk_list,
+		  int nr_conn, int min_chunk_sz, int max_chunk_sz)
+{
+        struct chunk *c;
+        struct path *p;
+        size_t page_mask;
+        size_t chunk_sz;
+        size_t size;
+
+        page_mask = get_page_mask();
+
+        list_for_each_entry(p, path_list, list) {
+                if (p->size <= min_chunk_sz)
+                        chunk_sz = p->size;
+                else if (max_chunk_sz)
+                        chunk_sz = max_chunk_sz;
+                else {
+                        chunk_sz = (p->size - (p->size % nr_conn)) / nr_conn;
+                        chunk_sz &= ~page_mask; /* align with page_sz */
+                        if (chunk_sz <= min_chunk_sz)
+                                chunk_sz = min_chunk_sz;
+                }
+
+                /* for (size = f->size; size > 0;) does not create a
+                 * file (chunk) when file size is 0. This do {} while
+                 * (size > 0) creates just open/close a 0-byte file.
+                 */
+                size = p->size;
+                do {
+                        c = alloc_chunk(p);
+                        if (!c)
+                                return -1;
+                        c->off = p->size - size;
+                        c->len = size < chunk_sz ? size : chunk_sz;
+                        size -= c->len;
+                        list_add_tail(&c->list, chunk_list);
+                } while (size > 0);
+        }
+
+        return 0;
+}
+
+void chunk_dump(struct list_head *chunk_list)
+{
+	struct chunk *c;
+
+	list_for_each_entry(c, chunk_list, list) {
+		printf("chunk: %s 0x%lx-%lx bytes\n",
+		       c->p->path, c->off, c->off + c->len);
+	}
+}
diff --git a/src/path.h b/src/path.h
new file mode 100644
index 0000000..3cc5327
--- /dev/null
+++ b/src/path.h
@@ -0,0 +1,192 @@
+#ifndef _PATH_H_
+#define _PATH_H_
+
+#include <limits.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <sys/stat.h>
+
+#include <list.h>
+#include <atomic.h>
+#include <ssh.h>
+
+struct path {
+	struct list_head	list;	/* mscp->path_list */
+
+	char	path[PATH_MAX];		/* file path */
+	size_t	size;			/* size of file on this path */
+	mode_t	mode;			/* permission */
+
+	char	dst_path[PATH_MAX];	/* copy dst path */
+
+	int	state;
+	lock	lock;
+	refcnt	refcnt;
+};
+#define FILE_STATE_INIT         0
+#define FILE_STATE_OPENED       1
+#define FILE_STATE_DONE         2
+
+struct chunk {
+	struct list_head	list;	/* mscp->chunk_list */
+
+	struct path *p;
+	size_t	off;	/* offset of this chunk on the file on path p */
+	size_t	len;	/* length of this chunk */
+	size_t	done;	/* copied bytes for this chunk by a thread */
+};
+
+
+
+/* recursivly walk through src_path and fill path_list for each file */
+int walk_src_path(sftp_session sftp, const char *src_path, struct list_head *path_list);
+
+/* fill path->dst_path for all files */
+int resolve_dst_path(sftp_session sftp, const char *src_path, const char *dst_path,
+		     struct list_head *path_list,
+		     bool src_path_is_dir, bool dst_path_is_dir);
+
+/* prepare chunk_list for files in the path_list */
+int prepare_chunk(struct list_head *path_list, struct list_head *chunk_list,
+		  int nr_conn, int min_chunk_sz, int max_chunk_sz);
+
+/* just print contents. just for debugging */
+void path_dump(struct list_head *path_list);
+void chunk_dump(struct list_head *chunk_list);
+
+
+
+
+/* wrap DIR/dirent and sftp_dir/sftp_attribute. not thread safe */
+struct mscp_dir {
+        DIR *l;
+        sftp_dir r;
+        sftp_session sftp;
+};
+typedef struct mscp_dir mdir;
+
+struct mscp_dirent {
+        struct dirent *l;
+        sftp_attributes r;
+};
+typedef struct mscp_dirent mdirent;
+
+#define mdirent_name(e) ((e->l) ? e->l->d_name : e->r->name)
+#define mdirent_is_dir(e) ((e->l) ?                                     \
+                           (e->l->d_type == DT_DIR) :                   \
+                           (e->r->type == SSH_FILEXFER_TYPE_DIRECTORY))
+#define mdirent_is_null(e) (e->l == NULL && e->r == NULL)
+
+static mdir *mscp_opendir(const char *path, sftp_session sftp)
+{
+        mdir *d;
+
+        if (!(d = malloc(sizeof(*d))))
+                return NULL;
+        memset(d, 0, sizeof(*d));
+
+        d->sftp = sftp;
+
+        if (sftp) {
+                d->r = sftp_opendir(sftp, path);
+                if (!d->r) {
+                        pr_err("sftp_opendir: %s: %s\n", path, sftp_get_ssh_error(sftp));
+                        free(d);
+                        return NULL;
+                }
+        } else {
+                d->l = opendir(path);
+                if (!d->l) {
+                        pr_err("opendir: %s: %s\n", path, strerrno());
+                        free(d);
+                        return NULL;
+                }
+        }
+        return d;
+}
+
+static int mscp_closedir(mdir *d)
+{
+        int ret;
+        if (d->r)
+                ret = sftp_closedir(d->r);
+        else
+                ret = closedir(d->l);
+        free(d);
+        return ret;
+}
+
+static mdirent *mscp_readdir(mdir *d)
+{
+        static mdirent e;
+
+        memset(&e, 0, sizeof(e));
+        if (d->r)
+                e.r = sftp_readdir(d->sftp, d->r);
+        else
+                e.l = readdir(d->l);
+        return &e;
+}
+
+/* warp stat/sftp_stat */
+struct mscp_stat {
+        struct stat l;
+        sftp_attributes r;
+};
+typedef struct mscp_stat mstat;
+
+static int mscp_stat(const char *path, mstat *s, sftp_session sftp)
+{
+        memset(s, 0, sizeof(*s));
+
+        if (sftp) {
+                s->r = sftp_stat(sftp, path);
+                if (!s->r)
+                        return -1;
+        } else {
+                if (stat(path, &s->l) < 0)
+                        return -1;
+        }
+
+        return 0;
+}
+
+static const char *mscp_stat_strerror(sftp_session sftp)
+{
+	if (sftp)
+		return sftp_get_ssh_error(sftp);
+	return strerrno();
+}
+
+static int mscp_stat_check_err_noent(sftp_session sftp)
+{
+	if (sftp) {
+		if (sftp_get_error(sftp) == SSH_FX_NO_SUCH_PATH ||
+		    sftp_get_error(sftp) == SSH_FX_NO_SUCH_FILE)
+			return 0;
+	} else {
+		if (errno == ENOENT)
+			return 0;
+	}
+	return -1;
+}
+
+static void mscp_stat_free(mstat s) {
+        if (s.r)
+                sftp_attributes_free(s.r);
+}
+
+#define mstat_size(s) ((s.r) ? s.r->size : s.l.st_size)
+#define mstat_mode(s) ((s.r) ?                                  \
+                       s.r->permissions :                       \
+                       s.l.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO))
+#define mstat_is_regular(s) ((s.r) ?                                    \
+                             (s.r->type == SSH_FILEXFER_TYPE_REGULAR) : \
+                             S_ISREG(s.l.st_mode))
+#define mstat_is_dir(s) ((s.r) ?                        \
+                         (s.r->type == SSH_FILEXFER_TYPE_DIRECTORY) :   \
+                         S_ISDIR(s.l.st_mode))
+
+
+
+#endif /* _PATH_H_ */
diff --git a/src/ssh.c b/src/ssh.c
index 67909d3..e063e28 100644
--- a/src/ssh.c
+++ b/src/ssh.c
@@ -148,7 +148,7 @@ static struct ssh_callbacks_struct cb = {
 	.userdata = NULL,
 };
 
-static ssh_session ssh_init_session(char *sshdst, struct ssh_opts *opts)
+static ssh_session ssh_init_session(const char *sshdst, struct ssh_opts *opts)
 {
 	ssh_session ssh = ssh_new();
 
@@ -187,7 +187,7 @@ free_out:
 	return NULL;
 }
 
-sftp_session ssh_init_sftp_session(char *sshdst, struct ssh_opts *opts)
+sftp_session ssh_init_sftp_session(const char *sshdst, struct ssh_opts *opts)
 {
 	sftp_session sftp;
 	ssh_session ssh = ssh_init_session(sshdst, opts);
diff --git a/src/ssh.h b/src/ssh.h
index f44f67f..9fdc822 100644
--- a/src/ssh.h
+++ b/src/ssh.h
@@ -25,7 +25,7 @@ struct ssh_opts {
 /* ssh_init_sftp_session() creates sftp_session. sshdst accpets
  * user@hostname and hostname notations (by libssh).
  */
-sftp_session ssh_init_sftp_session(char *sshdst, struct ssh_opts *opts);
+sftp_session ssh_init_sftp_session(const char *sshdst, struct ssh_opts *opts);
 void ssh_sftp_close(sftp_session sftp);
 
 #define sftp_ssh(sftp) (sftp)->session
diff --git a/src/test.c b/src/test.c
new file mode 100644
index 0000000..2452b6e
--- /dev/null
+++ b/src/test.c
@@ -0,0 +1,68 @@
+#include <util.h>
+#include <path.h>
+
+int path_walk_test(int argc, char **argv)
+{
+	struct list_head path_list, chunk_list, tmp;
+	mstat src, dst;
+	bool dst_is_dir = false, src_is_dir = false;
+	int ret, n;
+
+	
+	if (mscp_stat(argv[argc - 1], &dst, NULL) == 0) {
+		if (mstat_is_dir(dst))
+			dst_is_dir = true;
+	}
+
+	INIT_LIST_HEAD(&path_list);
+	INIT_LIST_HEAD(&chunk_list);
+
+	for (n = 1; n < argc - 1; n++) {
+		if (mscp_stat(argv[n], &src, NULL) < 0) {
+			pr_err("%s not found: %s\n", argv[n], strerrno());
+			return -1;
+		}
+		src_is_dir = mstat_is_dir(src);
+
+		INIT_LIST_HEAD(&tmp);
+		ret = walk_src_path(NULL, argv[n], &tmp);
+		if (ret < 0)
+			return ret;
+
+		ret = resolve_dst_path(NULL, argv[n], argv[argc - 1], &tmp,
+				       mstat_is_dir(src), dst_is_dir);
+		if (ret < 0)
+			return ret;
+
+		list_splice_tail(&tmp, &path_list);
+	}
+
+	path_dump(&path_list);
+
+	ret = prepare_chunk(&path_list, &chunk_list, 4, 1024 * 1024, 0);
+	if (ret < 0)
+		return ret;
+
+	//chunk_dump(&chunk_list);
+
+
+	return 0;
+}
+
+void usage()
+{
+	printf("test [SRC_PATH] ... [DST_PATH]\n");
+}
+
+int main(int argc, char **argv)
+{
+	if (argc < 3) {
+		usage();
+		return 1;
+	}
+
+	if (path_walk_test(argc, argv) < 0)
+		return 1;
+
+	return 0;
+}