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+/*
+ * connect.c - handles connections to ssh servers
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2003-2009 by Aris Adamantiadis
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ *
+ * The SSH Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _WIN32
+/*
+ * Only use Windows API functions available on Windows 2000 SP4 or later.
+ * The available constants are in <sdkddkver.h>.
+ * http://msdn.microsoft.com/en-us/library/aa383745.aspx
+ * http://blogs.msdn.com/oldnewthing/archive/2007/04/11/2079137.aspx
+ */
+#undef _WIN32_WINNT
+#ifdef HAVE_WSPIAPI_H
+#define _WIN32_WINNT 0x0500 /* _WIN32_WINNT_WIN2K */
+#undef NTDDI_VERSION
+#define NTDDI_VERSION 0x05000400 /* NTDDI_WIN2KSP4 */
+#else
+#define _WIN32_WINNT 0x0501 /* _WIN32_WINNT_WINXP */
+#undef NTDDI_VERSION
+#define NTDDI_VERSION 0x05010000 /* NTDDI_WINXP */
+#endif
+
+#if _MSC_VER >= 1400
+#include <io.h>
+#undef close
+#define close _close
+#endif /* _MSC_VER */
+#include <winsock2.h>
+#include <ws2tcpip.h>
+
+/* <wspiapi.h> is necessary for getaddrinfo before Windows XP, but it isn't
+ * available on some platforms like MinGW. */
+#ifdef HAVE_WSPIAPI_H
+#include <wspiapi.h>
+#endif
+
+#else /* _WIN32 */
+
+#include <netdb.h>
+#include <sys/socket.h>
+#include <sys/select.h>
+#include <netinet/in.h>
+
+#endif /* _WIN32 */
+
+#include "libssh/priv.h"
+#include "libssh/socket.h"
+#include "libssh/channels.h"
+#include "libssh/session.h"
+
+#ifndef HAVE_SELECT
+#error "Your system must have select()"
+#endif
+
+#ifndef HAVE_GETADDRINFO
+#error "Your system must have getaddrinfo()"
+#endif
+
+#ifdef HAVE_REGCOMP
+/* don't declare gnu extended regexp's */
+#ifndef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE
+#endif
+#include <regex.h>
+#endif /* HAVE_REGCOMP */
+
+#ifdef _WIN32
+void ssh_sock_set_nonblocking(socket_t sock) {
+ u_long nonblocking = 1;
+ ioctlsocket(sock, FIONBIO, &nonblocking);
+}
+
+void ssh_sock_set_blocking(socket_t sock) {
+ u_long nonblocking = 0;
+ ioctlsocket(sock, FIONBIO, &nonblocking);
+}
+
+#ifndef gai_strerror
+char WSAAPI *gai_strerrorA(int code) {
+ static char buf[256];
+
+ snprintf(buf, sizeof(buf), "Undetermined error code (%d)", code);
+
+ return buf;
+}
+#endif /* gai_strerror */
+
+#else /* _WIN32 */
+void ssh_sock_set_nonblocking(socket_t sock) {
+ fcntl(sock, F_SETFL, O_NONBLOCK);
+}
+
+void ssh_sock_set_blocking(socket_t sock) {
+ fcntl(sock, F_SETFL, 0);
+}
+
+#endif /* _WIN32 */
+
+#ifdef HAVE_REGCOMP
+static regex_t *ip_regex = NULL;
+
+/** @internal
+ * @brief initializes and compile the regexp to be used for IP matching
+ * @returns -1 on error (and error message is set)
+ * @returns 0 on success
+ */
+int ssh_regex_init(){
+ if(ip_regex==NULL){
+ int err;
+ regex_t *regex=malloc(sizeof (regex_t));
+ ZERO_STRUCTP(regex);
+ err=regcomp(regex,"^[0-9]+\\.[0-9]+\\.[0-9]+\\.[0-9]+$",REG_EXTENDED | REG_NOSUB);
+ if(err != 0){
+ char buffer[128];
+ regerror(err,regex,buffer,sizeof(buffer));
+ fprintf(stderr,"Error while compiling regular expression : %s\n",buffer);
+ SAFE_FREE(regex);
+ return -1;
+ }
+ ip_regex=regex;
+ }
+ return 0;
+}
+
+/** @internal
+ * @brief clean up the IP regexp
+ */
+void ssh_regex_finalize(){
+ if(ip_regex){
+ regfree(ip_regex);
+ SAFE_FREE(ip_regex);
+ }
+}
+
+#else /* HAVE_REGCOMP */
+int ssh_regex_init(){
+ return 0;
+}
+void ssh_regex_finalize(){
+}
+#endif
+
+
+static int ssh_connect_socket_close(socket_t s){
+#ifdef _WIN32
+ return closesocket(s);
+#else
+ return close(s);
+#endif
+}
+
+
+static int getai(ssh_session session, const char *host, int port, struct addrinfo **ai) {
+ const char *service = NULL;
+ struct addrinfo hints;
+ char s_port[10];
+
+ ZERO_STRUCT(hints);
+
+ hints.ai_protocol = IPPROTO_TCP;
+ hints.ai_family = PF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+
+ if (port == 0) {
+ hints.ai_flags = AI_PASSIVE;
+ } else {
+ snprintf(s_port, sizeof(s_port), "%hu", (unsigned short)port);
+ service = s_port;
+#ifdef AI_NUMERICSERV
+ hints.ai_flags=AI_NUMERICSERV;
+#endif
+ }
+#ifdef HAVE_REGCOMP
+ if(regexec(ip_regex,host,0,NULL,0) == 0){
+ /* this is an IP address */
+ ssh_log(session,SSH_LOG_PACKET,"host %s matches an IP address",host);
+ hints.ai_flags |= AI_NUMERICHOST;
+ }
+#endif
+ return getaddrinfo(host, service, &hints, ai);
+}
+
+static int ssh_connect_ai_timeout(ssh_session session, const char *host,
+ int port, struct addrinfo *ai, long timeout, long usec, socket_t s) {
+ struct timeval to;
+ fd_set set;
+ int rc = 0;
+ unsigned int len = sizeof(rc);
+
+ enter_function();
+
+ to.tv_sec = timeout;
+ to.tv_usec = usec;
+
+ ssh_sock_set_nonblocking(s);
+
+ ssh_log(session, SSH_LOG_RARE, "Trying to connect to host: %s:%d with "
+ "timeout %ld.%ld", host, port, timeout, usec);
+
+ /* The return value is checked later */
+ connect(s, ai->ai_addr, ai->ai_addrlen);
+ freeaddrinfo(ai);
+
+ FD_ZERO(&set);
+ FD_SET(s, &set);
+
+ rc = select(s + 1, NULL, &set, NULL, &to);
+ if (rc == 0) {
+ /* timeout */
+ ssh_set_error(session, SSH_FATAL,
+ "Timeout while connecting to %s:%d", host, port);
+ ssh_connect_socket_close(s);
+ leave_function();
+ return -1;
+ }
+
+ if (rc < 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Select error: %s", strerror(errno));
+ ssh_connect_socket_close(s);
+ leave_function();
+ return -1;
+ }
+ rc = 0;
+
+ /* Get connect(2) return code. Zero means no error */
+ getsockopt(s, SOL_SOCKET, SO_ERROR,(char *) &rc, &len);
+ if (rc != 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Connect to %s:%d failed: %s", host, port, strerror(rc));
+ ssh_connect_socket_close(s);
+ leave_function();
+ return -1;
+ }
+
+ /* s is connected ? */
+ ssh_log(session, SSH_LOG_PACKET, "Socket connected with timeout\n");
+ ssh_sock_set_blocking(s);
+
+ leave_function();
+ return s;
+}
+
+/**
+ * @internal
+ *
+ * @brief Connect to an IPv4 or IPv6 host specified by its IP address or
+ * hostname.
+ *
+ * @returns A file descriptor, < 0 on error.
+ */
+socket_t ssh_connect_host(ssh_session session, const char *host,
+ const char *bind_addr, int port, long timeout, long usec) {
+ socket_t s = -1;
+ int rc;
+ struct addrinfo *ai;
+ struct addrinfo *itr;
+
+ enter_function();
+
+ rc = getai(session,host, port, &ai);
+ if (rc != 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Failed to resolve hostname %s (%s)", host, gai_strerror(rc));
+ leave_function();
+ return -1;
+ }
+
+ for (itr = ai; itr != NULL; itr = itr->ai_next){
+ /* create socket */
+ s = socket(itr->ai_family, itr->ai_socktype, itr->ai_protocol);
+ if (s < 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Socket create failed: %s", strerror(errno));
+ continue;
+ }
+
+ if (bind_addr) {
+ struct addrinfo *bind_ai;
+ struct addrinfo *bind_itr;
+
+ ssh_log(session, SSH_LOG_PACKET, "Resolving %s\n", bind_addr);
+
+ rc = getai(session,bind_addr, 0, &bind_ai);
+ if (rc != 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Failed to resolve bind address %s (%s)",
+ bind_addr,
+ gai_strerror(rc));
+ leave_function();
+ return -1;
+ }
+
+ for (bind_itr = bind_ai; bind_itr != NULL; bind_itr = bind_itr->ai_next) {
+ if (bind(s, bind_itr->ai_addr, bind_itr->ai_addrlen) < 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Binding local address: %s", strerror(errno));
+ continue;
+ } else {
+ break;
+ }
+ }
+ freeaddrinfo(bind_ai);
+
+ /* Cannot bind to any local addresses */
+ if (bind_itr == NULL) {
+ ssh_connect_socket_close(s);
+ s = -1;
+ continue;
+ }
+ }
+
+ if (timeout || usec) {
+ socket_t ret = ssh_connect_ai_timeout(session, host, port, itr,
+ timeout, usec, s);
+ leave_function();
+ return ret;
+ }
+
+ if (connect(s, itr->ai_addr, itr->ai_addrlen) < 0) {
+ ssh_set_error(session, SSH_FATAL, "Connect failed: %s", strerror(errno));
+ ssh_connect_socket_close(s);
+ s = -1;
+ leave_function();
+ continue;
+ } else {
+ /* We are connected */
+ break;
+ }
+ }
+
+ freeaddrinfo(ai);
+ leave_function();
+
+ return s;
+}
+
+/**
+ * @internal
+ *
+ * @brief Launches a nonblocking connect to an IPv4 or IPv6 host
+ * specified by its IP address or hostname.
+ *
+ * @returns A file descriptor, < 0 on error.
+ * @warning very ugly !!!
+ */
+socket_t ssh_connect_host_nonblocking(ssh_session session, const char *host,
+ const char *bind_addr, int port) {
+ socket_t s = -1;
+ int rc;
+ struct addrinfo *ai;
+ struct addrinfo *itr;
+
+ enter_function();
+
+ rc = getai(session,host, port, &ai);
+ if (rc != 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Failed to resolve hostname %s (%s)", host, gai_strerror(rc));
+ leave_function();
+ return -1;
+ }
+
+ for (itr = ai; itr != NULL; itr = itr->ai_next){
+ /* create socket */
+ s = socket(itr->ai_family, itr->ai_socktype, itr->ai_protocol);
+ if (s < 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Socket create failed: %s", strerror(errno));
+ continue;
+ }
+
+ if (bind_addr) {
+ struct addrinfo *bind_ai;
+ struct addrinfo *bind_itr;
+
+ ssh_log(session, SSH_LOG_PACKET, "Resolving %s\n", bind_addr);
+
+ rc = getai(session,bind_addr, 0, &bind_ai);
+ if (rc != 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Failed to resolve bind address %s (%s)",
+ bind_addr,
+ gai_strerror(rc));
+ close(s);
+ s=-1;
+ break;
+ }
+
+ for (bind_itr = bind_ai; bind_itr != NULL; bind_itr = bind_itr->ai_next) {
+ if (bind(s, bind_itr->ai_addr, bind_itr->ai_addrlen) < 0) {
+ ssh_set_error(session, SSH_FATAL,
+ "Binding local address: %s", strerror(errno));
+ continue;
+ } else {
+ break;
+ }
+ }
+ freeaddrinfo(bind_ai);
+
+ /* Cannot bind to any local addresses */
+ if (bind_itr == NULL) {
+ ssh_connect_socket_close(s);
+ s = -1;
+ continue;
+ }
+ }
+ ssh_sock_set_nonblocking(s);
+
+ connect(s, itr->ai_addr, itr->ai_addrlen);
+ break;
+ }
+
+ freeaddrinfo(ai);
+ leave_function();
+
+ return s;
+}
+
+/**
+ * @addtogroup libssh_session
+ *
+ * @{
+ */
+
+/**
+ * @brief A wrapper for the select syscall
+ *
+ * This functions acts more or less like the select(2) syscall.\n
+ * There is no support for writing or exceptions.\n
+ *
+ * @param[in] channels Arrays of channels pointers terminated by a NULL.
+ * It is never rewritten.
+ *
+ * @param[out] outchannels Arrays of same size that "channels", there is no need
+ * to initialize it.
+ *
+ * @param[in] maxfd Maximum +1 file descriptor from readfds.
+ *
+ * @param[in] readfds A fd_set of file descriptors to be select'ed for
+ * reading.
+ *
+ * @param[in] timeout A timeout for the select.
+ *
+ * @return -1 if an error occured. E_INTR if it was interrupted, in
+ * that case, just restart it.
+ *
+ * @warning libssh is not threadsafe here. That means that if a signal is caught
+ * during the processing of this function, you cannot call ssh
+ * functions on sessions that are busy with ssh_select().
+ *
+ * @see select(2)
+ */
+int ssh_select(ssh_channel *channels, ssh_channel *outchannels, socket_t maxfd,
+ fd_set *readfds, struct timeval *timeout) {
+ struct timeval zerotime;
+ fd_set localset, localset2;
+ socket_t f;
+ int rep;
+ int set;
+ int i;
+ int j;
+
+ zerotime.tv_sec = 0;
+ zerotime.tv_usec = 0;
+
+ /*
+ * First, poll the maxfd file descriptors from the user with a zero-second
+ * timeout. They have the bigger priority.
+ */
+ if (maxfd > 0) {
+ memcpy(&localset, readfds, sizeof(fd_set));
+ rep = select(maxfd, &localset, NULL, NULL, &zerotime);
+ /* catch the eventual errors */
+ if (rep==-1) {
+ return -1;
+ }
+ }
+
+ /* Poll every channel */
+ j = 0;
+ for (i = 0; channels[i]; i++) {
+ if (channels[i]->session->alive) {
+ if(ssh_channel_poll(channels[i], 0) > 0) {
+ outchannels[j] = channels[i];
+ j++;
+ } else {
+ if(ssh_channel_poll(channels[i], 1) > 0) {
+ outchannels[j] = channels[i];
+ j++;
+ }
+ }
+ }
+ }
+ outchannels[j] = NULL;
+
+ /* Look into the localset for active fd */
+ set = 0;
+ for (f = 0; (f < maxfd) && !set; f++) {
+ if (FD_ISSET(f, &localset)) {
+ set = 1;
+ }
+ }
+
+ /* j != 0 means a channel has data */
+ if( (j != 0) || (set != 0)) {
+ if(maxfd > 0) {
+ memcpy(readfds, &localset, sizeof(fd_set));
+ }
+ return 0;
+ }
+
+ /*
+ * At this point, not any channel had any data ready for reading, nor any fd
+ * had data for reading.
+ */
+ memcpy(&localset, readfds, sizeof(fd_set));
+ for (i = 0; channels[i]; i++) {
+ if (channels[i]->session->alive) {
+ ssh_socket_fd_set(channels[i]->session->socket, &localset, &maxfd);
+ }
+ }
+
+ rep = select(maxfd, &localset, NULL, NULL, timeout);
+ if (rep == -1 && errno == EINTR) {
+ /* Interrupted by a signal */
+ return SSH_EINTR;
+ }
+
+ if (rep == -1) {
+ /*
+ * Was the error due to a libssh's channel or from a closed descriptor from
+ * the user? User closed descriptors have been caught in the first select
+ * and not closed since that moment. That case shouldn't occur at all
+ */
+ return -1;
+ }
+
+ /* Set the data_to_read flag on each session */
+ for (i = 0; channels[i]; i++) {
+ if (channels[i]->session->alive &&
+ ssh_socket_fd_isset(channels[i]->session->socket,&localset)) {
+ ssh_socket_set_toread(channels[i]->session->socket);
+ }
+ }
+
+ /* Now, test each channel */
+ j = 0;
+ for (i = 0; channels[i]; i++) {
+ if (channels[i]->session->alive &&
+ ssh_socket_fd_isset(channels[i]->session->socket,&localset)) {
+ if ((ssh_channel_poll(channels[i],0) > 0) ||
+ (ssh_channel_poll(channels[i], 1) > 0)) {
+ outchannels[j] = channels[i];
+ j++;
+ }
+ }
+ }
+ outchannels[j] = NULL;
+
+ FD_ZERO(&localset2);
+ for (f = 0; f < maxfd; f++) {
+ if (FD_ISSET(f, readfds) && FD_ISSET(f, &localset)) {
+ FD_SET(f, &localset2);
+ }
+ }
+
+ memcpy(readfds, &localset2, sizeof(fd_set));
+
+ return 0;
+}
+
+/** @} */
+
+/* vim: set ts=4 sw=4 et cindent: */