--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/svr-main.c	Tue Jul 27 14:44:43 2004 +0000
@@ -0,0 +1,347 @@
+/*
+ * Dropbear - a SSH2 server
+ * 
+ * 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 "dbutil.h"
+#include "session.h"
+#include "buffer.h"
+#include "signkey.h"
+#include "runopts.h"
+
+static int listensockets(int *sock, int *maxfd);
+static void sigchld_handler(int dummy);
+static void sigsegv_handler(int);
+static void sigintterm_handler(int fish);
+
+static int childpipes[MAX_UNAUTH_CLIENTS];
+
+#if defined(DBMULTI_dropbear) || !defined(DROPBEAR_MULTI)
+#if defined(DBMULTI_dropbear) && defined(DROPBEAR_MULTI)
+int dropbear_main(int argc, char ** argv)
+#else
+int main(int argc, char ** argv)
+#endif
+{
+	
+	fd_set fds;
+	struct timeval seltimeout;
+	unsigned int i, j;
+	int val;
+	int maxsock = -1;
+	struct sockaddr remoteaddr;
+	int remoteaddrlen;
+	int listensocks[MAX_LISTEN_ADDR];
+	unsigned int listensockcount = 0;
+	FILE * pidfile;
+
+	int childsock;
+	pid_t childpid;
+	int childpipe[2];
+
+	struct sigaction sa_chld;
+
+	_dropbear_exit = svr_dropbear_exit;
+	_dropbear_log = svr_dropbear_log;
+
+	/* get commandline options */
+	svr_getopts(argc, argv);
+
+	/* fork */
+	if (svr_opts.forkbg) {
+		int closefds = 0;
+#ifndef DEBUG_TRACE
+		if (!svr_opts.usingsyslog) {
+			closefds = 1;
+		}
+#endif
+		if (daemon(0, closefds) < 0) {
+			dropbear_exit("Failed to create background process: %s",
+					strerror(errno));
+		}
+	}
+
+#ifndef DISABLE_SYSLOG
+	if (svr_opts.usingsyslog) {
+		startsyslog();
+	}
+#endif
+
+	/* should be done after syslog is working */
+	if (svr_opts.forkbg) {
+		dropbear_log(LOG_INFO, "Running in background");
+	} else {
+		dropbear_log(LOG_INFO, "Not forking");
+	}
+
+	/* create a PID file so that we can be killed easily */
+	pidfile = fopen(DROPBEAR_PIDFILE, "w");
+	if (pidfile) {
+		fprintf(pidfile, "%d\n", getpid());
+		fclose(pidfile);
+	}
+
+	/* set up cleanup handler */
+	if (signal(SIGINT, sigintterm_handler) == SIG_ERR || 
+#ifndef DEBUG_VALGRIND
+		signal(SIGTERM, sigintterm_handler) == SIG_ERR ||
+#endif
+		signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
+		dropbear_exit("signal() error");
+	}
+
+	/* catch and reap zombie children */
+	sa_chld.sa_handler = sigchld_handler;
+	sa_chld.sa_flags = SA_NOCLDSTOP;
+	if (sigaction(SIGCHLD, &sa_chld, NULL) < 0) {
+		dropbear_exit("signal() error");
+	}
+	if (signal(SIGSEGV, sigsegv_handler) == SIG_ERR) {
+		dropbear_exit("signal() error");
+	}
+
+	/* sockets to identify pre-authenticated clients */
+	for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) {
+		childpipes[i] = -1;
+	}
+	
+	/* Set up the listening sockets */
+	/* XXX XXX ports */
+	listensockcount = listensockets(listensocks, &maxsock);
+
+	/* incoming connection select loop */
+	for(;;) {
+
+		FD_ZERO(&fds);
+		
+		seltimeout.tv_sec = 60;
+		seltimeout.tv_usec = 0;
+		
+		/* listening sockets */
+		for (i = 0; i < listensockcount; i++) {
+			FD_SET(listensocks[i], &fds);
+		}
+
+		/* pre-authentication clients */
+		for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) {
+			if (childpipes[i] >= 0) {
+				FD_SET(childpipes[i], &fds);
+				maxsock = MAX(maxsock, childpipes[i]);
+			}
+		}
+
+		val = select(maxsock+1, &fds, NULL, NULL, &seltimeout);
+
+		if (exitflag) {
+			unlink(DROPBEAR_PIDFILE);
+			dropbear_exit("Terminated by signal");
+		}
+		
+		if (val == 0) {
+			/* timeout reached */
+			continue;
+		}
+
+		if (val < 0) {
+			if (errno == EINTR) {
+				continue;
+			}
+			dropbear_exit("Listening socket error");
+		}
+
+		/* close fds which have been authed or closed - auth.c handles
+		 * closing the auth sockets on success */
+		for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) {
+			if (childpipes[i] >= 0 && FD_ISSET(childpipes[i], &fds)) {
+				close(childpipes[i]);
+				childpipes[i] = -1;
+			}
+		}
+
+		/* handle each socket which has something to say */
+		for (i = 0; i < listensockcount; i++) {
+			if (!FD_ISSET(listensocks[i], &fds)) 
+				continue;
+
+			/* child connection XXX - ip6 stuff here */
+			remoteaddrlen = sizeof(struct sockaddr_in);
+			childsock = accept(listensocks[i], &remoteaddr, &remoteaddrlen);
+
+			if (childsock < 0) {
+				/* accept failed */
+				continue;
+			}
+
+			/* check for max number of connections not authorised */
+			for (j = 0; j < MAX_UNAUTH_CLIENTS; j++) {
+				if (childpipes[j] < 0) {
+					break;
+				}
+			}
+
+			if (j == MAX_UNAUTH_CLIENTS) {
+				/* no free connections */
+				/* TODO - possibly log, though this would be an easy way
+				 * to fill logs/disk */
+				close(childsock);
+				continue;
+			}
+
+			if (pipe(childpipe) < 0) {
+				TRACE(("error creating child pipe"));
+				close(childsock);
+				continue;
+			}
+
+			if ((childpid = fork()) == 0) {
+
+				/* child */
+				char * addrstring = NULL;
+#ifdef DEBUG_FORKGPROF
+				extern void _start(void), etext(void);
+				monstartup((u_long)&_start, (u_long)&etext);
+#endif /* DEBUG_FORKGPROF */
+
+				addrstring = getaddrstring(&remoteaddr);
+				dropbear_log(LOG_INFO, "Child connection from %s", addrstring);
+				m_free(addrstring);
+
+				if (setsid() < 0) {
+					dropbear_exit("setsid: %s", strerror(errno));
+				}
+
+				/* make sure we close sockets */
+				for (i = 0; i < listensockcount; i++) {
+					if (m_close(listensocks[i]) == DROPBEAR_FAILURE) {
+						dropbear_exit("Couldn't close socket");
+					}
+				}
+
+				if (m_close(childpipe[0]) == DROPBEAR_FAILURE) {
+					dropbear_exit("Couldn't close socket");
+				}
+
+				/* start the session */
+				svr_session(childsock, childpipe[1], 
+								getaddrhostname(&remoteaddr));
+				/* don't return */
+				assert(0);
+			}
+			
+			/* parent */
+			childpipes[j] = childpipe[0];
+			if (m_close(childpipe[1]) == DROPBEAR_FAILURE
+					|| m_close(childsock) == DROPBEAR_FAILURE) {
+				dropbear_exit("Couldn't close socket");
+			}
+		}
+	} /* for(;;) loop */
+
+	/* don't reach here */
+	return -1;
+}
+#endif
+
+/* catch + reap zombie children */
+static void sigchld_handler(int fish) {
+	struct sigaction sa_chld;
+
+	while(waitpid(-1, NULL, WNOHANG) > 0); 
+
+	sa_chld.sa_handler = sigchld_handler;
+	sa_chld.sa_flags = SA_NOCLDSTOP;
+	if (sigaction(SIGCHLD, &sa_chld, NULL) < 0) {
+		dropbear_exit("signal() error");
+	}
+}
+
+/* catch any segvs */
+static void sigsegv_handler(int fish) {
+	fprintf(stderr, "Aiee, segfault! You should probably report "
+			"this as a bug to the developer\n");
+	exit(EXIT_FAILURE);
+}
+
+/* catch ctrl-c or sigterm */
+static void sigintterm_handler(int fish) {
+
+	exitflag = 1;
+}
+
+/* Set up listening sockets for all the requested ports */
+static int listensockets(int *sock, int *maxfd) {
+	
+	int listensock; /* listening fd */
+	struct sockaddr_in listen_addr;
+	struct linger linger;
+	unsigned int i;
+	int val;
+
+	for (i = 0; i < svr_opts.portcount; i++) {
+
+		/* iterate through all the sockets to listen on */
+		listensock = socket(PF_INET, SOCK_STREAM, 0);
+		if (listensock < 0) {
+			dropbear_exit("Failed to create socket");
+		}
+
+		val = 1;
+		/* set to reuse, quick timeout */
+		setsockopt(listensock, SOL_SOCKET, SO_REUSEADDR,
+				(void*) &val, sizeof(val));
+		linger.l_onoff = 1;
+		linger.l_linger = 5;
+		setsockopt(listensock, SOL_SOCKET, SO_LINGER,
+				(void*)&linger, sizeof(linger));
+
+		/* disable nagle */
+		setsockopt(listensock, IPPROTO_TCP, TCP_NODELAY,
+				(void*)&val, sizeof(val));
+
+		memset((void*)&listen_addr, 0x0, sizeof(listen_addr));
+		listen_addr.sin_family = AF_INET;
+		listen_addr.sin_port = htons(svr_opts.ports[i]);
+		listen_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+		memset(&(listen_addr.sin_zero), '\0', 8);
+
+		if (bind(listensock, (struct sockaddr *)&listen_addr,
+					sizeof(listen_addr)) < 0) {
+			dropbear_exit("Bind failed port %d", svr_opts.ports[i]);
+		}
+
+		/* listen */
+		if (listen(listensock, 20) < 0) { /* TODO set listen count */
+			dropbear_exit("Listen failed");
+		}
+
+		/* nonblock */
+		if (fcntl(listensock, F_SETFL, O_NONBLOCK) < 0) {
+			dropbear_exit("Failed to set non-blocking");
+		}
+
+		sock[i] = listensock;
+		*maxfd = MAX(listensock, *maxfd);
+	}
+
+	return svr_opts.portcount;
+}