sftp.c

一个FTP下载的源代码。代码质量非常高

    pktin = sftp_recv();
    if (!pktin) {
	fxp_internal_error("could not connect");
	return 0;
    }
    if (pktin->type != SSH_FXP_VERSION) {
	fxp_internal_error("did not receive FXP_VERSION");
        sftp_pkt_free(pktin);
	return 0;
    }
    remotever = sftp_pkt_getuint32(pktin);
    if (remotever > SFTP_PROTO_VERSION) {
	fxp_internal_error
	    ("remote protocol is more advanced than we support");
        sftp_pkt_free(pktin);
	return 0;
    }
    /*
     * In principle, this packet might also contain extension-
     * string pairs. We should work through them and look for any
     * we recognise. In practice we don't currently do so because
     * we know we don't recognise _any_.
     */
    sftp_pkt_free(pktin);

    return 1;
}

/*
 * Canonify a pathname.
 */
struct sftp_request *fxp_realpath_send(char *path)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_REALPATH);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring_start(pktout);
    sftp_pkt_addstring_str(pktout, path);
    sftp_send(pktout);

    return req;
}

char *fxp_realpath_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    sfree(req);

    if (pktin->type == SSH_FXP_NAME) {
	int count;
	char *path;
	int len;

	count = sftp_pkt_getuint32(pktin);
	if (count != 1) {
	    fxp_internal_error("REALPATH returned name count != 1\n");
            sftp_pkt_free(pktin);
	    return NULL;
	}
	sftp_pkt_getstring(pktin, &path, &len);
	if (!path) {
	    fxp_internal_error("REALPATH returned malformed FXP_NAME\n");
            sftp_pkt_free(pktin);
	    return NULL;
	}
	path = mkstr(path, len);
	sftp_pkt_free(pktin);
	return path;
    } else {
	fxp_got_status(pktin);
        sftp_pkt_free(pktin);
	return NULL;
    }
}

/*
 * Open a file.
 */
struct sftp_request *fxp_open_send(char *path, int type)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_OPEN);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, path);
    sftp_pkt_adduint32(pktout, type);
    sftp_pkt_adduint32(pktout, 0);     /* (FIXME) empty ATTRS structure */
    sftp_send(pktout);

    return req;
}

struct fxp_handle *fxp_open_recv(struct sftp_packet *pktin,
				 struct sftp_request *req)
{
    sfree(req);

    if (pktin->type == SSH_FXP_HANDLE) {
	char *hstring;
	struct fxp_handle *handle;
	int len;

	sftp_pkt_getstring(pktin, &hstring, &len);
	if (!hstring) {
	    fxp_internal_error("OPEN returned malformed FXP_HANDLE\n");
            sftp_pkt_free(pktin);
	    return NULL;
	}
	handle = snew(struct fxp_handle);
	handle->hstring = mkstr(hstring, len);
	handle->hlen = len;
	sftp_pkt_free(pktin);
	return handle;
    } else {
	fxp_got_status(pktin);
        sftp_pkt_free(pktin);
	return NULL;
    }
}

/*
 * Open a directory.
 */
struct sftp_request *fxp_opendir_send(char *path)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_OPENDIR);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, path);
    sftp_send(pktout);

    return req;
}

struct fxp_handle *fxp_opendir_recv(struct sftp_packet *pktin,
				    struct sftp_request *req)
{
    sfree(req);
    if (pktin->type == SSH_FXP_HANDLE) {
	char *hstring;
	struct fxp_handle *handle;
	int len;

	sftp_pkt_getstring(pktin, &hstring, &len);
	if (!hstring) {
	    fxp_internal_error("OPENDIR returned malformed FXP_HANDLE\n");
            sftp_pkt_free(pktin);
	    return NULL;
	}
	handle = snew(struct fxp_handle);
	handle->hstring = mkstr(hstring, len);
	handle->hlen = len;
	sftp_pkt_free(pktin);
	return handle;
    } else {
	fxp_got_status(pktin);
        sftp_pkt_free(pktin);
	return NULL;
    }
}

/*
 * Close a file/dir.
 */
struct sftp_request *fxp_close_send(struct fxp_handle *handle)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_CLOSE);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring_start(pktout);
    sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
    sftp_send(pktout);

    sfree(handle->hstring);
    sfree(handle);

    return req;
}

void fxp_close_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    sfree(req);
    fxp_got_status(pktin);
    sftp_pkt_free(pktin);
}

struct sftp_request *fxp_mkdir_send(char *path)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_MKDIR);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, path);
    sftp_pkt_adduint32(pktout, 0);     /* (FIXME) empty ATTRS structure */
    sftp_send(pktout);

    return req;
}

int fxp_mkdir_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    int id;
    sfree(req);
    id = fxp_got_status(pktin);
    sftp_pkt_free(pktin);
    if (id != 1) {
    	return 0;
    }
    return 1;
}

struct sftp_request *fxp_rmdir_send(char *path)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_RMDIR);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, path);
    sftp_send(pktout);

    return req;
}

int fxp_rmdir_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    int id;
    sfree(req);
    id = fxp_got_status(pktin);
    sftp_pkt_free(pktin);
    if (id != 1) {
    	return 0;
    }
    return 1;
}

struct sftp_request *fxp_remove_send(char *fname)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_REMOVE);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, fname);
    sftp_send(pktout);

    return req;
}

int fxp_remove_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    int id;
    sfree(req);
    id = fxp_got_status(pktin);
    sftp_pkt_free(pktin);
    if (id != 1) {
    	return 0;
    }
    return 1;
}

struct sftp_request *fxp_rename_send(char *srcfname, char *dstfname)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_RENAME);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, srcfname);
    sftp_pkt_addstring(pktout, dstfname);
    sftp_send(pktout);

    return req;
}

int fxp_rename_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    int id;
    sfree(req);
    id = fxp_got_status(pktin);
    sftp_pkt_free(pktin);
    if (id != 1) {
    	return 0;
    }
    return 1;
}

/*
 * Retrieve the attributes of a file. We have fxp_stat which works
 * on filenames, and fxp_fstat which works on open file handles.
 */
struct sftp_request *fxp_stat_send(char *fname)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_STAT);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, fname);
    sftp_send(pktout);

    return req;
}

int fxp_stat_recv(struct sftp_packet *pktin, struct sftp_request *req,
		  struct fxp_attrs *attrs)
{
    sfree(req);
    if (pktin->type == SSH_FXP_ATTRS) {
	*attrs = sftp_pkt_getattrs(pktin);
        sftp_pkt_free(pktin);
	return 1;
    } else {
	fxp_got_status(pktin);
        sftp_pkt_free(pktin);
	return 0;
    }
}

struct sftp_request *fxp_fstat_send(struct fxp_handle *handle)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_FSTAT);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring_start(pktout);
    sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
    sftp_send(pktout);

    return req;
}

int fxp_fstat_recv(struct sftp_packet *pktin, struct sftp_request *req,
		   struct fxp_attrs *attrs)
{
    sfree(req);
    if (pktin->type == SSH_FXP_ATTRS) {
	*attrs = sftp_pkt_getattrs(pktin);
        sftp_pkt_free(pktin);
	return 1;
    } else {
	fxp_got_status(pktin);
        sftp_pkt_free(pktin);
	return 0;
    }
}

/*
 * Set the attributes of a file.
 */
struct sftp_request *fxp_setstat_send(char *fname, struct fxp_attrs attrs)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_SETSTAT);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring(pktout, fname);
    sftp_pkt_addattrs(pktout, attrs);
    sftp_send(pktout);

    return req;
}

int fxp_setstat_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    int id;
    sfree(req);
    id = fxp_got_status(pktin);
    sftp_pkt_free(pktin);
    if (id != 1) {
    	return 0;
    }
    return 1;
}

struct sftp_request *fxp_fsetstat_send(struct fxp_handle *handle,
				       struct fxp_attrs attrs)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_FSETSTAT);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring_start(pktout);
    sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
    sftp_pkt_addattrs(pktout, attrs);
    sftp_send(pktout);

    return req;
}

int fxp_fsetstat_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
    int id;
    sfree(req);
    id = fxp_got_status(pktin);
    sftp_pkt_free(pktin);
    if (id != 1) {
    	return 0;
    }
    return 1;
}

/*
 * Read from a file. Returns the number of bytes read, or -1 on an
 * error, or possibly 0 if EOF. (I'm not entirely sure whether it
 * will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
 * error indicator. It might even depend on the SFTP server.)
 */
struct sftp_request *fxp_read_send(struct fxp_handle *handle,
				   uint64 offset, int len)
{
    struct sftp_request *req = sftp_alloc_request();
    struct sftp_packet *pktout;

    pktout = sftp_pkt_init(SSH_FXP_READ);
    sftp_pkt_adduint32(pktout, req->id);
    sftp_pkt_addstring_start(pktout);
    sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
    sftp_pkt_adduint64(pktout, offset);
    sftp_pkt_adduint32(pktout, len);
    sftp_send(pktout);

    return req;
}

int fxp_read_recv(struct sftp_packet *pktin, struct sftp_request *req,
		  char *buffer, int len)
{
    sfree(req);
    if (pktin->type == SSH_FXP_DATA) {
	char *str;
	int rlen;

	sftp_pkt_getstring(pktin, &str, &rlen);

	if (rlen > len || rlen < 0) {
	    fxp_internal_error("READ returned more bytes than requested");
            sftp_pkt_free(pktin);
	    return -1;
	}

	memcpy(buffer, str, rlen);