/* Copyright (C) 2002-2010 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 ipv6_ip(char *host); int dotted_ip(char *host, int partial); 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 find_free_port6(int start, int end); int have_ssh_env(void); char *ipv6_getnameinfo(struct sockaddr *paddr, int addrlen); char *ipv6_getipaddr(struct sockaddr *paddr, int addrlen); int listen6(int port); int connect_tcp(char *host, int port); int listen_tcp(int port, in_addr_t iface, int try6); 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 ipv6_ip(char *host_in) { char *p, *host, a[2]; int ncol = 0, nhex = 0; if (host_in[0] == '[') { host = host_in + 1; } else { host = host_in; } if (strstr(host, "::ffff:") == host || strstr(host, "::FFFF:") == host) { return dotted_ip(host + strlen("::ffff:"), 0); } a[1] = '\0'; p = host; while (*p != '\0' && *p != '%' && *p != ']') { if (*p == ':') { ncol++; } else { nhex++; } a[0] = *p; if (strpbrk(a, ":abcdef0123456789") == a) { p++; continue; } return 0; } if (ncol < 2 || ncol > 8 || nhex == 0) { return 0; } else { return 1; } } int dotted_ip(char *host, int partial) { int len, dots = 0; char *p = host; if (!host) { return 0; } if (!isdigit((unsigned char) host[0])) { return 0; } len = strlen(host); if (!partial && !isdigit((unsigned char) host[len-1])) { return 0; } while (*p != '\0') { if (*p == '.') dots++; if (*p == '.' || isdigit((unsigned char) (*p))) { p++; continue; } return 0; } if (!partial && dots != 3) { 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') { 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 = connect_tcp(client->host, 113)) < 0) { exit(1); } else { close(sock); exit(0); } } } #endif if (block || refused) { ; } else if ((sock = connect_tcp(client->host, 113)) < 0) { rfbLog("ident_username: could not connect to ident: %s:%d\n", client->host, 113); } else { char msg[128]; 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 = 3; tv.tv_usec = 0; ret = select(sock+1, &rfds, NULL, NULL, &tv); if (ret > 0) { int i; char *q, *p; for (i=0; i < (int) sizeof(msg); 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 = listen_tcp(port, htonl(INADDR_ANY), 0); if (sock >= 0) { close(sock); return port; } } return 0; } int find_free_port6(int start, int end) { int port; if (start <= 0) { start = 1024; } if (end <= 0) { end = 65530; } for (port = start; port <= end; port++) { int sock = listen6(port); 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; } char *ipv6_getnameinfo(struct sockaddr *paddr, int addrlen) { #if X11VNC_IPV6 char name[200]; if (noipv6) { return strdup("unknown"); } if (getnameinfo(paddr, addrlen, name, sizeof(name), NULL, 0, 0) == 0) { return strdup(name); } #endif return strdup("unknown"); } char *ipv6_getipaddr(struct sockaddr *paddr, int addrlen) { #if X11VNC_IPV6 && defined(NI_NUMERICHOST) char name[200]; if (noipv6) { return strdup("unknown"); } if (getnameinfo(paddr, addrlen, name, sizeof(name), NULL, 0, NI_NUMERICHOST) == 0) { return strdup(name); } #endif return strdup("unknown"); } int listen6(int port) { #if X11VNC_IPV6 struct sockaddr_in6 sin; int fd = -1, one = 1; if (noipv6) { return -1; } if (port <= 0 || 65535 < port) { /* for us, invalid port means do not listen. */ return -1; } fd = socket(AF_INET6, SOCK_STREAM, 0); if (fd < 0) { rfbLogPerror("listen6: socket"); rfbLog("(Ignore the above error if this system is IPv4-only.)\n"); return -1; } if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one)) < 0) { rfbLogPerror("listen6: setsockopt SO_REUSEADDR"); close(fd); return -1; } #if defined(SOL_IPV6) && defined(IPV6_V6ONLY) if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, (char *)&one, sizeof(one)) < 0) { rfbLogPerror("listen6: setsockopt IPV6_V6ONLY"); close(fd); return -1; } #endif memset((char *)&sin, 0, sizeof(sin)); sin.sin6_family = AF_INET6; sin.sin6_port = htons(port); sin.sin6_addr = in6addr_any; if (listen_str6) { if (!strcmp(listen_str6, "localhost") || !strcmp(listen_str6, "::1")) { sin.sin6_addr = in6addr_loopback; } else { int err; struct addrinfo *ai; struct addrinfo hints; char service[32]; memset(&hints, 0, sizeof(hints)); sprintf(service, "%d", port); hints.ai_family = AF_INET6; hints.ai_socktype = SOCK_STREAM; #ifdef AI_ADDRCONFIG hints.ai_flags |= AI_ADDRCONFIG; #endif #ifdef AI_NUMERICHOST if(ipv6_ip(listen_str6)) { hints.ai_flags |= AI_NUMERICHOST; } #endif #ifdef AI_NUMERICSERV hints.ai_flags |= AI_NUMERICSERV; #endif err = getaddrinfo(listen_str6, service, &hints, &ai); if (err == 0) { struct addrinfo *ap = ai; err = 1; while (ap != NULL) { char *s = ipv6_getipaddr(ap->ai_addr, ap->ai_addrlen); if (!s) s = strdup("unknown"); rfbLog("listen6: checking: %s family: %d\n", s, ap->ai_family); if (ap->ai_family == AF_INET6) { memcpy((char *)&sin, ap->ai_addr, sizeof(sin)); rfbLog("listen6: using: %s scope_id: %d\n", s, sin.sin6_scope_id); err = 0; free(s); break; } free(s); ap = ap->ai_next; } freeaddrinfo(ai); } if (err != 0) { rfbLog("Invalid or Unsupported -listen6 string: %s\n", listen_str6); close(fd); return -1; } } } else if (allow_list && !strcmp(allow_list, "127.0.0.1")) { sin.sin6_addr = in6addr_loopback; } else if (listen_str) { if (!strcmp(listen_str, "localhost")) { sin.sin6_addr = in6addr_loopback; } } if (bind(fd, (struct sockaddr *) &sin, sizeof(sin)) < 0) { rfbLogPerror("listen6: bind"); close(fd); return -1; } if (listen(fd, 32) < 0) { rfbLogPerror("listen6: listen"); close(fd); return -1; } return fd; #else if (port) {} return -1; #endif } int connect_tcp(char *host, int port) { double t0 = dnow(); int fd = -1; int fail4 = noipv4; if (getenv("IPV4_FAILS")) { fail4 = 2; } rfbLog("connect_tcp: trying: %s %d\n", host, port); if (fail4) { if (fail4 > 1) { rfbLog("TESTING: IPV4_FAILS for connect_tcp.\n"); } } else { fd = rfbConnectToTcpAddr(host, port); } if (fd >= 0) { return fd; } rfbLogPerror("connect_tcp: connection failed"); if (dnow() - t0 < 4.0) { rfbLog("connect_tcp: re-trying %s %d\n", host, port); usleep (100 * 1000); if (!fail4) { fd = rfbConnectToTcpAddr(host, port); } if (fd < 0) { rfbLogPerror("connect_tcp: connection failed"); } } if (fd < 0 && !noipv6) { #if X11VNC_IPV6 int err; struct addrinfo *ai; struct addrinfo hints; char service[32], *host2, *q; rfbLog("connect_tcp: trying IPv6 %s %d\n", host, port); memset(&hints, 0, sizeof(hints)); sprintf(service, "%d", port); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_STREAM; #ifdef AI_ADDRCONFIG hints.ai_flags |= AI_ADDRCONFIG; #endif if(ipv6_ip(host)) { #ifdef AI_NUMERICHOST rfbLog("connect_tcp[ipv6]: setting AI_NUMERICHOST for %s\n", host); hints.ai_flags |= AI_NUMERICHOST; #endif } #ifdef AI_NUMERICSERV hints.ai_flags |= AI_NUMERICSERV; #endif if (!strcmp(host, "127.0.0.1")) { host2 = strdup("::1"); } else if (host[0] == '[') { host2 = strdup(host+1); } else { host2 = strdup(host); } q = strrchr(host2, ']'); if (q) { *q = '\0'; } err = getaddrinfo(host2, service, &hints, &ai); if (err != 0) { rfbLog("connect_tcp[ipv6]: getaddrinfo[%d]: %s\n", err, gai_strerror(err)); usleep(100 * 1000); err = getaddrinfo(host2, service, &hints, &ai); } free(host2); if (err != 0) { rfbLog("connect_tcp[ipv6]: getaddrinfo[%d]: %s\n", err, gai_strerror(err)); } else { struct addrinfo *ap = ai; while (ap != NULL) { int sock; if (fail4) { struct sockaddr_in6 *s6ptr; if (ap->ai_family != AF_INET6) { rfbLog("connect_tcp[ipv6]: skipping AF_INET address under -noipv4\n"); ap = ap->ai_next; continue; } #ifdef IN6_IS_ADDR_V4MAPPED s6ptr = (struct sockaddr_in6 *) ap->ai_addr; if (IN6_IS_ADDR_V4MAPPED(&(s6ptr->sin6_addr))) { rfbLog("connect_tcp[ipv6]: skipping V4MAPPED address under -noipv4\n"); ap = ap->ai_next; continue; } #endif } sock = socket(ap->ai_family, ap->ai_socktype, ap->ai_protocol); if (sock == -1) { rfbLogPerror("connect_tcp[ipv6]: socket"); if (0) rfbLog("(Ignore the above error if this system is IPv4-only.)\n"); } else { int res = -1, dmsg = 0; char *s = ipv6_getipaddr(ap->ai_addr, ap->ai_addrlen); if (!s) s = strdup("unknown"); rfbLog("connect_tcp[ipv6]: trying sock=%d fam=%d proto=%d using %s\n", sock, ap->ai_family, ap->ai_protocol, s); res = connect(sock, ap->ai_addr, ap->ai_addrlen); #if defined(SOL_IPV6) && defined(IPV6_V6ONLY) if (res != 0) { int zero = 0; rfbLogPerror("connect_tcp[ipv6]: connect"); dmsg = 1; if (setsockopt(sock, SOL_IPV6, IPV6_V6ONLY, (char *)&zero, sizeof(zero)) == 0) { rfbLog("connect_tcp[ipv6]: trying again with IPV6_V6ONLY=0\n"); res = connect(sock, ap->ai_addr, ap->ai_addrlen); dmsg = 0; } else { rfbLogPerror("connect_tcp[ipv6]: setsockopt IPV6_V6ONLY"); } } #endif if (res == 0) { rfbLog("connect_tcp[ipv6]: connect OK\n"); fd = sock; if (!ipv6_client_ip_str) { ipv6_client_ip_str = strdup(s); } free(s); break; } else { if (!dmsg) rfbLogPerror("connect_tcp[ipv6]: connect"); close(sock); } free(s); } ap = ap->ai_next; } freeaddrinfo(ai); } #endif } if (fd < 0 && !fail4) { /* this is a kludge for IPv4-only machines getting v4mapped string. */ char *q, *host2; if (host[0] == '[') { host2 = strdup(host+1); } else { host2 = strdup(host); } q = strrchr(host2, ']'); if (q) { *q = '\0'; } if (strstr(host2, "::ffff:") == host2 || strstr(host2, "::FFFF:") == host2) { char *host3 = host2 + strlen("::ffff:"); if (dotted_ip(host3, 0)) { rfbLog("connect_tcp[ipv4]: trying fallback to IPv4 for %s\n", host2); fd = rfbConnectToTcpAddr(host3, port); if (fd < 0) { rfbLogPerror("connect_tcp[ipv4]: connection failed"); } } } free(host2); } return fd; } int listen_tcp(int port, in_addr_t iface, int try6) { int fd = -1; int fail4 = noipv4; if (getenv("IPV4_FAILS")) { fail4 = 2; } if (port <= 0 || 65535 < port) { /* for us, invalid port means do not listen. */ return -1; } if (fail4) { if (fail4 > 1) { rfbLog("TESTING: IPV4_FAILS for listen_tcp: port=%d try6=%d\n", port, try6); } } else { fd = rfbListenOnTCPPort(port, iface); } if (fd >= 0) { return fd; } if (fail4 > 1) { rfbLogPerror("listen_tcp: listen failed"); } if (fd < 0 && try6 && ipv6_listen && !noipv6) { #if X11VNC_IPV6 char *save = listen_str6; if (iface == htonl(INADDR_LOOPBACK)) { listen_str6 = "localhost"; rfbLog("listen_tcp: retrying on IPv6 in6addr_loopback ...\n"); fd = listen6(port); } else if (iface == htonl(INADDR_ANY)) { listen_str6 = NULL; rfbLog("listen_tcp: retrying on IPv6 in6addr_any ...\n"); fd = listen6(port); } listen_str6 = save; #endif } return fd; }