/* Copyright (C) 2002-2009 Karl J. Runge All rights reserved. This file is part of x11vnc. x11vnc is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. x11vnc 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 General Public License for more details. You should have received a copy of the GNU General Public License along with x11vnc; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA or see . In addition, as a special exception, Karl J. Runge gives permission to link the code of its release of x11vnc with the OpenSSL project's "OpenSSL" library (or with modified versions of it that use the same license as the "OpenSSL" library), and distribute the linked executables. You must obey the GNU General Public License in all respects for all of the code used other than "OpenSSL". If you modify this file, you may extend this exception to your version of the file, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ /* -- inet.c -- */ #include "x11vnc.h" #include "unixpw.h" #include "sslhelper.h" /* * Simple utility to map host name to dotted IP address. Ignores aliases. * Up to caller to free returned string. */ char *host2ip(char *host); char *raw2host(char *raw, int len); char *raw2ip(char *raw); char *ip2host(char *ip); int dotted_ip(char *host); int get_remote_port(int sock); int get_local_port(int sock); char *get_remote_host(int sock); char *get_local_host(int sock); char *ident_username(rfbClientPtr client); int find_free_port(int start, int end); int have_ssh_env(void); static int get_port(int sock, int remote); static char *get_host(int sock, int remote); char *host2ip(char *host) { struct hostent *hp; struct sockaddr_in addr; char *str; if (! host_lookup) { return NULL; } hp = gethostbyname(host); if (!hp) { return NULL; } memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = *(unsigned long *)hp->h_addr; str = strdup(inet_ntoa(addr.sin_addr)); return str; } char *raw2host(char *raw, int len) { char *str; #if LIBVNCSERVER_HAVE_NETDB_H && LIBVNCSERVER_HAVE_NETINET_IN_H struct hostent *hp; if (! host_lookup) { return strdup("unknown"); } hp = gethostbyaddr(raw, len, AF_INET); if (!hp) { return strdup(inet_ntoa(*((struct in_addr *)raw))); } str = strdup(hp->h_name); #else str = strdup("unknown"); #endif return str; } char *raw2ip(char *raw) { return strdup(inet_ntoa(*((struct in_addr *)raw))); } char *ip2host(char *ip) { char *str; #if LIBVNCSERVER_HAVE_NETDB_H && LIBVNCSERVER_HAVE_NETINET_IN_H struct hostent *hp; in_addr_t iaddr; if (! host_lookup) { return strdup("unknown"); } iaddr = inet_addr(ip); if (iaddr == htonl(INADDR_NONE)) { return strdup("unknown"); } hp = gethostbyaddr((char *)&iaddr, sizeof(in_addr_t), AF_INET); if (!hp) { return strdup("unknown"); } str = strdup(hp->h_name); #else str = strdup("unknown"); #endif return str; } int dotted_ip(char *host) { char *p = host; while (*p != '\0') { if (*p == '.' || isdigit((unsigned char) (*p))) { p++; continue; } return 0; } return 1; } static int get_port(int sock, int remote) { struct sockaddr_in saddr; unsigned int saddr_len; int saddr_port; saddr_len = sizeof(saddr); memset(&saddr, 0, sizeof(saddr)); saddr_port = -1; if (remote) { if (!getpeername(sock, (struct sockaddr *)&saddr, &saddr_len)) { saddr_port = ntohs(saddr.sin_port); } } else { if (!getsockname(sock, (struct sockaddr *)&saddr, &saddr_len)) { saddr_port = ntohs(saddr.sin_port); } } return saddr_port; } int get_remote_port(int sock) { return get_port(sock, 1); } int get_local_port(int sock) { return get_port(sock, 0); } static char *get_host(int sock, int remote) { struct sockaddr_in saddr; unsigned int saddr_len; int saddr_port; char *saddr_ip_str = NULL; saddr_len = sizeof(saddr); memset(&saddr, 0, sizeof(saddr)); saddr_port = -1; #if LIBVNCSERVER_HAVE_NETINET_IN_H if (remote) { if (!getpeername(sock, (struct sockaddr *)&saddr, &saddr_len)) { saddr_ip_str = inet_ntoa(saddr.sin_addr); } } else { if (!getsockname(sock, (struct sockaddr *)&saddr, &saddr_len)) { saddr_ip_str = inet_ntoa(saddr.sin_addr); } } #endif if (! saddr_ip_str) { saddr_ip_str = "unknown"; } return strdup(saddr_ip_str); } char *get_remote_host(int sock) { return get_host(sock, 1); } char *get_local_host(int sock) { return get_host(sock, 0); } char *ident_username(rfbClientPtr client) { ClientData *cd = (ClientData *) client->clientData; char *str, *newhost, *user = NULL, *newuser = NULL; int len; if (cd) { user = cd->username; } if (!user || *user == '\0') { char msg[128]; int n, sock, ok = 0; int block = 0; int refused = 0; /* * need to check to see if the operation will block for * a long time: a firewall may just ignore our packets. */ #if LIBVNCSERVER_HAVE_FORK { pid_t pid, pidw; int rc; if ((pid = fork()) > 0) { usleep(100 * 1000); /* 0.1 sec for quick success or refusal */ pidw = waitpid(pid, &rc, WNOHANG); if (pidw <= 0) { usleep(1500 * 1000); /* 1.5 sec */ pidw = waitpid(pid, &rc, WNOHANG); if (pidw <= 0) { int rc2; rfbLog("ident_username: set block=1 (hung)\n"); block = 1; kill(pid, SIGTERM); usleep(100 * 1000); waitpid(pid, &rc2, WNOHANG); } } if (pidw > 0 && !block) { if (WIFEXITED(rc) && WEXITSTATUS(rc) == 1) { rfbLog("ident_username: set refused=1 (exit)\n"); refused = 1; } } } else if (pid == -1) { ; } else { /* child */ signal(SIGHUP, SIG_DFL); signal(SIGINT, SIG_DFL); signal(SIGQUIT, SIG_DFL); signal(SIGTERM, SIG_DFL); if ((sock = rfbConnectToTcpAddr(client->host, 113)) < 0) { exit(1); } else { close(sock); exit(0); } } } #endif if (block || refused) { ; } else if ((sock = rfbConnectToTcpAddr(client->host, 113)) < 0) { rfbLog("ident_username: could not connect to ident: %s:%d\n", client->host, 113); } else { int ret; fd_set rfds; struct timeval tv; int rport = get_remote_port(client->sock); int lport = get_local_port(client->sock); sprintf(msg, "%d, %d\r\n", rport, lport); n = write(sock, msg, strlen(msg)); FD_ZERO(&rfds); FD_SET(sock, &rfds); tv.tv_sec = 4; tv.tv_usec = 0; ret = select(sock+1, &rfds, NULL, NULL, &tv); if (ret > 0) { int i; char *q, *p; for (i=0; i<128; i++) { msg[i] = '\0'; } usleep(250*1000); n = read(sock, msg, 127); close(sock); if (n <= 0) goto badreply; /* 32782 , 6000 : USERID : UNIX :runge */ q = strstr(msg, "USERID"); if (!q) goto badreply; q = strstr(q, ":"); if (!q) goto badreply; q++; q = strstr(q, ":"); if (!q) goto badreply; q++; q = lblanks(q); p = q; while (*p) { if (*p == '\r' || *p == '\n') { *p = '\0'; } p++; } ok = 1; if (strlen(q) > 24) { *(q+24) = '\0'; } newuser = strdup(q); badreply: n = 0; /* avoid syntax error */ } else { close(sock); } } if (! ok || !newuser) { newuser = strdup("unknown-user"); } if (cd) { if (cd->username) { free(cd->username); } cd->username = newuser; } user = newuser; } if (!strcmp(user, "unknown-user") && cd && cd->unixname[0] != '\0') { user = cd->unixname; } if (unixpw && openssl_last_ip && strstr("UNIX:", user) != user) { newhost = ip2host(openssl_last_ip); } else { newhost = ip2host(client->host); } len = strlen(user) + 1 + strlen(newhost) + 1; str = (char *) malloc(len); sprintf(str, "%s@%s", user, newhost); free(newhost); return str; } int find_free_port(int start, int end) { int port; if (start <= 0) { start = 1024; } if (end <= 0) { end = 65530; } for (port = start; port <= end; port++) { int sock = rfbListenOnTCPPort(port, htonl(INADDR_ANY)); if (sock >= 0) { close(sock); return port; } } return 0; } int have_ssh_env(void) { char *str, *p = getenv("SSH_CONNECTION"); char *rhost, *rport, *lhost, *lport; if (! p) { char *q = getenv("SSH_CLIENT"); if (! q) { return 0; } if (strstr(q, "127.0.0.1") != NULL) { return 0; } return 1; } if (strstr(p, "127.0.0.1") != NULL) { return 0; } str = strdup(p); p = strtok(str, " "); rhost = p; p = strtok(NULL, " "); if (! p) goto fail; rport = p; p = strtok(NULL, " "); if (! p) goto fail; lhost = p; p = strtok(NULL, " "); if (! p) goto fail; lport = p; if (0) fprintf(stderr, "%d/%d - '%s' '%s'\n", atoi(rport), atoi(lport), rhost, lhost); if (atoi(rport) <= 16 || atoi(rport) > 65535) { goto fail; } if (atoi(lport) <= 16 || atoi(lport) > 65535) { goto fail; } if (!strcmp(rhost, lhost)) { goto fail; } free(str); return 1; fail: free(str); return 0; }