view listener.c @ 1653:76189c9ffea2

External Public-Key Authentication API (#72) * Implemented dynamic loading of an external plug-in shared library to delegate public key authentication * Moved conditional compilation of the plugin infrastructure into the configure.ac script to be able to add -ldl to dropbear build only when the flag is enabled * Added tags file to the ignore list * Updated API to have the constructor to return function pointers in the pliugin instance. Added support for passing user name to the checkpubkey function. Added options to the session returned by the plugin and have dropbear to parse and process them * Added -rdynamic to the linker flags when EPKA is enabled * Changed the API to pass a previously created session to the checkPubKey function (created during preauth) * Added documentation to the API * Added parameter addrstring to plugin creation function * Modified the API to retrieve the auth options. Instead of having them as field of the EPKASession struct, they are stored internally (plugin-dependent) in the plugin/session and retrieved through a pointer to a function (in the session) * Changed option string to be a simple char * instead of unsigned char *
author fabriziobertocci <fabriziobertocci@gmail.com>
date Wed, 15 May 2019 09:43:57 -0400
parents 58a74cb829b8
children ce3ce75a6e04
line wrap: on
line source

/*
 * Dropbear SSH
 * 
 * Copyright (c) 2002,2003 Matt Johnston
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. */

#include "includes.h"
#include "listener.h"
#include "session.h"
#include "dbutil.h"

void listeners_initialise() {

	/* just one slot to start with */
	ses.listeners = (struct Listener**)m_malloc(sizeof(struct Listener*));
	ses.listensize = 1;
	ses.listeners[0] = NULL;

}

void set_listener_fds(fd_set * readfds) {

	unsigned int i, j;
	struct Listener *listener;

	/* check each in turn */
	for (i = 0; i < ses.listensize; i++) {
		listener = ses.listeners[i];
		if (listener != NULL) {
			for (j = 0; j < listener->nsocks; j++) {
				FD_SET(listener->socks[j], readfds);
			}
		}
	}
}


void handle_listeners(const fd_set * readfds) {

	unsigned int i, j;
	struct Listener *listener;
	int sock;

	/* check each in turn */
	for (i = 0; i < ses.listensize; i++) {
		listener = ses.listeners[i];
		if (listener != NULL) {
			for (j = 0; j < listener->nsocks; j++) {
				sock = listener->socks[j];
				if (FD_ISSET(sock, readfds)) {
					listener->acceptor(listener, sock);
				}
			}
		}
	}
} /* Woo brace matching */


/* acceptor(int fd, void* typedata) is a function to accept connections, 
 * cleanup(void* typedata) happens when cleaning up */
struct Listener* new_listener(const int socks[], unsigned int nsocks,
		int type, void* typedata, 
		void (*acceptor)(const struct Listener* listener, int sock),
		void (*cleanup)(const struct Listener*)) {

	unsigned int i, j;
	struct Listener *newlisten = NULL;
	/* try get a new structure to hold it */
	for (i = 0; i < ses.listensize; i++) {
		if (ses.listeners[i] == NULL) {
			break;
		}
	}

	/* or create a new one */
	if (i == ses.listensize) {
		if (ses.listensize > MAX_LISTENERS) {
			TRACE(("leave newlistener: too many already"))
			for (j = 0; j < nsocks; j++) {
				close(socks[i]);
			}
			return NULL;
		}
		
		ses.listeners = (struct Listener**)m_realloc(ses.listeners,
				(ses.listensize+LISTENER_EXTEND_SIZE)
				*sizeof(struct Listener*));

		ses.listensize += LISTENER_EXTEND_SIZE;

		for (j = i; j < ses.listensize; j++) {
			ses.listeners[j] = NULL;
		}
	}

	for (j = 0; j < nsocks; j++) {
		ses.maxfd = MAX(ses.maxfd, socks[j]);
	}

	TRACE(("new listener num %d ", i))

	newlisten = (struct Listener*)m_malloc(sizeof(struct Listener));
	newlisten->index = i;
	newlisten->type = type;
	newlisten->typedata = typedata;
	newlisten->nsocks = nsocks;
	memcpy(newlisten->socks, socks, nsocks * sizeof(int));
	newlisten->acceptor = acceptor;
	newlisten->cleanup = cleanup;

	ses.listeners[i] = newlisten;
	return newlisten;
}

/* Return the first listener which matches the type-specific comparison
 * function. Particularly needed for global requests, like tcp */
struct Listener * get_listener(int type, const void* typedata,
		int (*match)(const void*, const void*)) {

	unsigned int i;
	struct Listener* listener;

	for (i = 0, listener = ses.listeners[i]; i < ses.listensize; i++) {
		if (listener->type == type
				&& match(typedata, listener->typedata)) {
			return listener;
		}
	}

	return NULL;
}

void remove_listener(struct Listener* listener) {

	unsigned int j;

	if (listener->cleanup) {
		listener->cleanup(listener);
	}

	for (j = 0; j < listener->nsocks; j++) {
		close(listener->socks[j]);
	}
	ses.listeners[listener->index] = NULL;
	m_free(listener);
}

void remove_all_listeners(void) {
	unsigned int i;
	for (i = 0; i < ses.listensize; i++) {
		if (ses.listeners[i]) {
			remove_listener(ses.listeners[i]);
		}
	}
	m_free(ses.listeners);
}