Disallow leading lines before the ident for server (#102) Per RFC4253 4.2 clients must be able to process other lines of data before the version string, server behavior is not defined neither with MUST/SHOULD nor with MAY. If server process up to 50 lines too - it may cause too long hanging session with invalid/evil client that consume host resources and potentially may lead to DDoS on poor embedded boxes. Let's require first line from client to be version string and fail early if it's not - matches both RFC and real OpenSSH behavior.

#ifndef DROPBEAR_DROPBEAR_LIST_H
#define DROPBEAR_DROPBEAR_LIST_H

struct _m_list;

struct _m_list_elem {
	void *item;
	struct _m_list_elem *next;
	struct _m_list_elem *prev;
	struct _m_list *list;
};
	
typedef struct _m_list_elem m_list_elem;

struct _m_list {
	m_list_elem *first;
	m_list_elem *last;
};

typedef struct _m_list m_list;

m_list * list_new(void);
void list_append(m_list *list, void *item);
/* returns the item for the element removed */
void * list_remove(m_list_elem *elem);


#endif /* DROPBEAR_DROPBEAR_LIST_H */