-/*
- Copyright (C) Andrew Tridgell 1998
+/* -*- c-file-style: "linux" -*-
+
+ Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>
+ Copyright (C) 2001 by Martin Pool <mbp@samba.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+/**
+ * @file socket.c
+ *
+ * Socket functions used in rsync.
+ **/
+
+#include "rsync.h"
+
+#ifndef HAVE_GETADDRINFO
+#include "lib/addrinfo.h"
+#endif
+
+/* Establish a proxy connection on an open socket to a web roxy by
+ * using the CONNECT method. */
+static int establish_proxy_connection(int fd, char *host, int port)
+{
+ char buffer[1024];
+ char *cp;
+
+ snprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port);
+ if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) {
+ rprintf(FERROR, "failed to write to proxy: %s\n",
+ strerror(errno));
+ return -1;
+ }
+
+ for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) {
+ if (read(fd, cp, 1) != 1) {
+ rprintf(FERROR, "failed to read from proxy: %s\n",
+ strerror(errno));
+ return -1;
+ }
+ if (*cp == '\n')
+ break;
+ }
+
+ if (*cp != '\n')
+ cp++;
+ *cp-- = '\0';
+ if (*cp == '\r')
+ *cp = '\0';
+ if (strncmp(buffer, "HTTP/", 5) != 0) {
+ rprintf(FERROR, "bad response from proxy - %s\n",
+ buffer);
+ return -1;
+ }
+ for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++)
+ ;
+ while (*cp == ' ')
+ cp++;
+ if (*cp != '2') {
+ rprintf(FERROR, "bad response from proxy - %s\n",
+ buffer);
+ return -1;
+ }
+ /* throw away the rest of the HTTP header */
+ while (1) {
+ for (cp = buffer; cp < &buffer[sizeof(buffer) - 1];
+ cp++) {
+ if (read(fd, cp, 1) != 1) {
+ rprintf(FERROR, "failed to read from proxy: %s\n",
+ strerror(errno));
+ return -1;
+ }
+ if (*cp == '\n')
+ break;
+ }
+ if ((cp > buffer) && (*cp == '\n'))
+ cp--;
+ if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r')))
+ break;
+ }
+ return 0;
+}
+
+
+
+/**
+ * Open a socket to a tcp remote host with the specified port .
+ *
+ * Based on code from Warren. Proxy support by Stephen Rothwell.
+ * getaddrinfo() rewrite contributed by KAME.net.
+ *
+ * Now that we support IPv6 we need to look up the remote machine's
+ * address first, using @p af_hint to set a preference for the type
+ * of address. Then depending on whether it has v4 or v6 addresses we
+ * try to open a connection.
+ *
+ * The loop allows for machines with some addresses which may not be
+ * reachable, perhaps because we can't e.g. route ipv6 to that network
+ * but we can get ip4 packets through.
+ *
+ * @param bind_address Local address to use. Normally NULL to bind
+ * the wildcard address.
+ *
+ * @param af_hint Address family, e.g. AF_INET or AF_INET6.
+ **/
+int open_socket_out(char *host, int port, const char *bind_address,
+ int af_hint)
+{
+ int type = SOCK_STREAM;
+ int error;
+ int s;
+ int result;
+ struct addrinfo hints, *res0, *res;
+ char portbuf[10];
+ char *h;
+ int proxied = 0;
+ char buffer[1024];
+ char *cp;
+
+ /* if we have a RSYNC_PROXY env variable then redirect our
+ * connetcion via a web proxy at the given address. The format
+ * is hostname:port */
+ h = getenv("RSYNC_PROXY");
+ proxied = (h != NULL) && (*h != '\0');
+
+ if (proxied) {
+ strlcpy(buffer, h, sizeof(buffer));
+ cp = strchr(buffer, ':');
+ if (cp == NULL) {
+ rprintf(FERROR,
+ "invalid proxy specification: should be HOST:PORT\n");
+ return -1;
+ }
+ *cp++ = '\0';
+ strcpy(portbuf, cp);
+ h = buffer;
+ } else {
+ snprintf(portbuf, sizeof(portbuf), "%d", port);
+ h = host;
+ }
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = af_hint;
+ hints.ai_socktype = type;
+ error = getaddrinfo(h, portbuf, &hints, &res0);
+ if (error) {
+ rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",
+ h, portbuf, gai_strerror(error));
+ return -1;
+ }
+
+ s = -1;
+ for (res = res0; res; res = res->ai_next) {
+ s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+ if (s < 0)
+ continue;
+
+ if (bind_address) {
+ struct addrinfo bhints, *bres;
+
+ memset(&bhints, 0, sizeof(bhints));
+ bhints.ai_family = res->ai_family;
+ bhints.ai_socktype = type;
+ bhints.ai_flags = AI_PASSIVE;
+ error = getaddrinfo(bind_address, NULL, &bhints, &bres);
+ if (error) {
+ rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s <noport>: %s\n",
+ bind_address, gai_strerror(error));
+ continue;
+ }
+ if (bres->ai_next) {
+ rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s resolved to multiple hosts\n",
+ bind_address);
+ freeaddrinfo(bres);
+ continue;
+ }
+ bind(s, bres->ai_addr, bres->ai_addrlen);
+ }
+
+ if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
+ close(s);
+ s = -1;
+ continue;
+ }
+ if (proxied &&
+ establish_proxy_connection(s, host, port) != 0) {
+ close(s);
+ s = -1;
+ continue;
+ } else
+ break;
+ }
+ freeaddrinfo(res0);
+ if (s < 0) {
+ rprintf(FERROR, RSYNC_NAME ": failed to connect to %s: %s\n",
+ h, strerror(errno));
+ return -1;
+ }
+ return s;
+}
+
+
+/**
+ * Open an outgoing socket, but allow for it to be intercepted by
+ * $RSYNC_CONNECT_PROG, which will execute a program across a TCP
+ * socketpair rather than really opening a socket.
+ *
+ * We use this primarily in testing to detect TCP flow bugs, but not
+ * cause security problems by really opening remote connections.
+ *
+ * This is based on the Samba LIBSMB_PROG feature.
+ *
+ * @param bind_address Local address to use. Normally NULL to get the stack default.
+ **/
+int open_socket_out_wrapped (char *host,
+ int port,
+ const char *bind_address,
+ int af_hint)
+{
+ char *prog;
+
+ if ((prog = getenv ("RSYNC_CONNECT_PROG")) != NULL)
+ return sock_exec (prog);
+ else
+ return open_socket_out (host, port, bind_address,
+ af_hint);
+}
+
+
+
+/**
+ * Open a socket of the specified type, port and address for incoming data
+ *
+ * Try to be better about handling the results of getaddrinfo(): when
+ * opening an inbound socket, we might get several address results,
+ * e.g. for the machine's ipv4 and ipv6 name.
+ *
+ * If binding a wildcard, then any one of them should do. If an address
+ * was specified but it's insufficiently specific then that's not our
+ * fault.
+ *
+ * However, some of the advertized addresses may not work because e.g. we
+ * don't have IPv6 support in the kernel. In that case go on and try all
+ * addresses until one succeeds.
+ *
+ * @param bind_address Local address to bind, or NULL to allow it to
+ * default.
+ **/
+static int open_socket_in(int type, int port, const char *bind_address,
+ int af_hint)
+{
+ int one=1;
+ int s;
+ struct addrinfo hints, *res, *resp;
+ char portbuf[10];
+ int error;
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = af_hint;
+ hints.ai_socktype = type;
+ hints.ai_flags = AI_PASSIVE;
+ snprintf(portbuf, sizeof(portbuf), "%d", port);
+ error = getaddrinfo(bind_address, portbuf, &hints, &res);
+ if (error) {
+ rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
+ bind_address, gai_strerror(error));
+ return -1;
+ }
+ /* XXX: Do we need to care about getting multiple results
+ * back? I think probably not; if the user passed
+ * bind_address == NULL and we set AI_PASSIVE then we ought to
+ * get a wildcard result. */
+
+ resp = res;
+ while (1) {
+ s = socket(resp->ai_family, resp->ai_socktype, resp->ai_protocol);
+
+ if (s >= 0) {
+ break; /* got a socket */
+ } else if ((resp = resp->ai_next)) {
+ switch (errno) {
+ case EPROTONOSUPPORT:
+ case EAFNOSUPPORT:
+ case EPFNOSUPPORT:
+ /* See if there's another address that will work... */
+ continue;
+ }
+ }
+
+ rprintf(FERROR, RSYNC_NAME ": open inbound socket"
+ "(dom=%d, type=%d, proto=%d) failed: %s\n",
+ resp->ai_family, resp->ai_socktype, resp->ai_protocol,
+ strerror(errno));
+ goto fail;
+ }
+
+ setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one));
+
+ /* now we've got a socket - we need to bind it */
+ if (bind(s, res->ai_addr, res->ai_addrlen) < 0) {
+ rprintf(FERROR, RSYNC_NAME ": bind failed on port %d\n", port);
+ close(s);
+ goto fail;
+ }
+
+ return s;
+
+fail:
+ freeaddrinfo(res);
+ return -1;
+}
+
+
/*
- socket functions used in rsync
+ * Determine if a file descriptor is in fact a socket
+ */
+int is_a_socket(int fd)
+{
+ int v;
+ socklen_t l;
+ l = sizeof(int);
+
+ /* Parameters to getsockopt, setsockopt etc are very
+ * unstandardized across platforms, so don't be surprised if
+ * there are compiler warnings on e.g. SCO OpenSwerver or AIX.
+ * It seems they all eventually get the right idea.
+ *
+ * Debian says: ``The fifth argument of getsockopt and
+ * setsockopt is in reality an int [*] (and this is what BSD
+ * 4.* and libc4 and libc5 have). Some POSIX confusion
+ * resulted in the present socklen_t. The draft standard has
+ * not been adopted yet, but glibc2 already follows it and
+ * also has socklen_t [*]. See also accept(2).''
+ *
+ * We now return to your regularly scheduled programming. */
+ return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
+}
+
+
+void start_accept_loop(int port, int (*fn)(int ))
+{
+ int s;
+ extern char *bind_address;
+
+ /* open an incoming socket */
+ s = open_socket_in(SOCK_STREAM, port, bind_address,
+ global_opts.af_hint);
+ if (s == -1)
+ exit_cleanup(RERR_SOCKETIO);
+
+ /* ready to listen */
+ if (listen(s, 5) == -1) {
+ close(s);
+ exit_cleanup(RERR_SOCKETIO);
+ }
+
+
+ /* now accept incoming connections - forking a new process
+ for each incoming connection */
+ while (1) {
+ fd_set fds;
+ int fd;
+ struct sockaddr addr;
+ int in_addrlen = sizeof(addr);
+
+ /* close log file before the potentially very long select so
+ file can be trimmed by another process instead of growing
+ forever */
+ log_close();
+
+ FD_ZERO(&fds);
+ FD_SET(s, &fds);
+
+ if (select(s+1, &fds, NULL, NULL, NULL) != 1) {
+ continue;
+ }
+
+ if(!FD_ISSET(s, &fds)) continue;
+
+ fd = accept(s,(struct sockaddr *)&addr,&in_addrlen);
+
+ if (fd == -1) continue;
+
+ signal(SIGCHLD, SIG_IGN);
+
+ /* we shouldn't have any children left hanging around
+ but I have had reports that on Digital Unix zombies
+ are produced, so this ensures that they are reaped */
+#ifdef WNOHANG
+ while (waitpid(-1, NULL, WNOHANG) > 0);
+#endif
+
+ if (fork()==0) {
+ close(s);
+ /* open log file in child before possibly giving
+ up privileges */
+ log_open();
+ _exit(fn(fd));
+ }
+
+ close(fd);
+ }
+}
+
+
+enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
- */
+struct
+{
+ char *name;
+ int level;
+ int option;
+ int value;
+ int opttype;
+} socket_options[] = {
+ {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
+ {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
+ {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
+#ifdef TCP_NODELAY
+ {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
+#endif
+#ifdef IPTOS_LOWDELAY
+ {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
+#endif
+#ifdef IPTOS_THROUGHPUT
+ {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
+#endif
+#ifdef SO_SNDBUF
+ {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
+#endif
+#ifdef SO_RCVBUF
+ {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
+#endif
+#ifdef SO_SNDLOWAT
+ {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
+#endif
+#ifdef SO_RCVLOWAT
+ {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
+#endif
+#ifdef SO_SNDTIMEO
+ {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
+#endif
+#ifdef SO_RCVTIMEO
+ {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
+#endif
+ {NULL,0,0,0,0}};
+
+
+
+/****************************************************************************
+set user socket options
+****************************************************************************/
+void set_socket_options(int fd, char *options)
+{
+ char *tok;
+ if (!options || !*options) return;
+
+ options = strdup(options);
+
+ if (!options) out_of_memory("set_socket_options");
+
+ for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) {
+ int ret=0,i;
+ int value = 1;
+ char *p;
+ int got_value = 0;
+
+ if ((p = strchr(tok,'='))) {
+ *p = 0;
+ value = atoi(p+1);
+ got_value = 1;
+ }
+
+ for (i=0;socket_options[i].name;i++)
+ if (strcmp(socket_options[i].name,tok)==0)
+ break;
+
+ if (!socket_options[i].name) {
+ rprintf(FERROR,"Unknown socket option %s\n",tok);
+ continue;
+ }
+
+ switch (socket_options[i].opttype) {
+ case OPT_BOOL:
+ case OPT_INT:
+ ret = setsockopt(fd,socket_options[i].level,
+ socket_options[i].option,(char *)&value,sizeof(int));
+ break;
+
+ case OPT_ON:
+ if (got_value)
+ rprintf(FERROR,"syntax error - %s does not take a value\n",tok);
+
+ {
+ int on = socket_options[i].value;
+ ret = setsockopt(fd,socket_options[i].level,
+ socket_options[i].option,(char *)&on,sizeof(int));
+ }
+ break;
+ }
+
+ if (ret != 0)
+ rprintf(FERROR, "failed to set socket option %s: %s\n", tok,
+ strerror(errno));
+ }
+
+ free(options);
+}
+
+/****************************************************************************
+become a daemon, discarding the controlling terminal
+****************************************************************************/
+void become_daemon(void)
+{
+ int i;
+
+ if (fork()) {
+ _exit(0);
+ }
-int open_socket_out(char *host, int port)
+ /* detach from the terminal */
+#ifdef HAVE_SETSID
+ setsid();
+#else
+#ifdef TIOCNOTTY
+ i = open("/dev/tty", O_RDWR);
+ if (i >= 0) {
+ ioctl(i, (int) TIOCNOTTY, (char *)0);
+ close(i);
+ }
+#endif /* TIOCNOTTY */
+#endif
+ /* make sure that stdin, stdout an stderr don't stuff things
+ up (library functions, for example) */
+ for (i=0;i<3;i++) {
+ close(i);
+ open("/dev/null", O_RDWR);
+ }
+}
+
+/**
+ * Return the IP addr of the client as a string
+ **/
+char *client_addr(int fd)
+{
+ struct sockaddr ss;
+ int length = sizeof(ss);
+ static char addr_buf[100];
+ static int initialised;
+
+ if (initialised) return addr_buf;
+
+ initialised = 1;
+
+ if (getpeername(fd, &ss, &length)) {
+ exit_cleanup(RERR_SOCKETIO);
+ }
+
+ getnameinfo(&ss, length,
+ addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
+ return addr_buf;
+}
+
+
+/**
+ * Return the DNS name of the client
+ **/
+char *client_name(int fd)
{
+ struct sockaddr ss;
+ int length = sizeof(ss);
+ static char name_buf[100];
+ static char port_buf[100];
+ char *def = "UNKNOWN";
+ static int initialised;
+ struct addrinfo hints, *res, *res0;
+ int error;
+
+ if (initialised) return name_buf;
+
+ initialised = 1;
+
+ strcpy(name_buf,def);
+
+ if (getpeername(fd, (struct sockaddr *)&ss, &length)) {
+ /* FIXME: Can we really not continue? */
+ rprintf(FERROR, RSYNC_NAME ": getpeername on fd%d failed: %s\n",
+ fd, strerror(errno));
+ exit_cleanup(RERR_SOCKETIO);
+ }
+
+#ifdef INET6
+ if (ss.sa_family == AF_INET6 &&
+ IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
+ struct sockaddr_in6 sin6;
+ struct sockaddr_in *sin;
+
+ memcpy(&sin6, &ss, sizeof(sin6));
+ sin = (struct sockaddr_in *)&ss;
+ memset(sin, 0, sizeof(*sin));
+ sin->sin_family = AF_INET;
+ length = sizeof(struct sockaddr_in);
+#ifdef HAVE_SOCKADDR_LEN
+ sin->sin_len = length;
+#endif
+ sin->sin_port = sin6.sin6_port;
+ memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12],
+ sizeof(sin->sin_addr));
+ }
+#endif
+
+ /* reverse lookup */
+ if (getnameinfo((struct sockaddr *)&ss, length,
+ name_buf, sizeof(name_buf), port_buf, sizeof(port_buf),
+ NI_NAMEREQD | NI_NUMERICSERV) != 0) {
+ strcpy(name_buf, def);
+ rprintf(FERROR, "reverse name lookup failed\n");
+ }
+
+ /* forward lookup */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = PF_UNSPEC;
+ hints.ai_flags = AI_CANONNAME;
+ hints.ai_socktype = SOCK_STREAM;
+ error = getaddrinfo(name_buf, port_buf, &hints, &res0);
+ if (error) {
+ strcpy(name_buf, def);
+ rprintf(FERROR,
+ RSYNC_NAME ": forward name lookup for %s failed: %s\n",
+ port_buf,
+ gai_strerror(error));
+ return name_buf;
+ }
+
+ /* XXX sin6_flowinfo and other fields */
+ for (res = res0; res; res = res->ai_next) {
+ if (res->ai_family != ss.sa_family)
+ continue;
+ if (res->ai_addrlen != length)
+ continue;
+ if (memcmp(res->ai_addr, &ss, res->ai_addrlen) == 0)
+ break;
+ }
+
+ /* TODO: Do a forward lookup as well to prevent spoofing */
+
+ if (res == NULL) {
+ strcpy(name_buf, def);
+ rprintf(FERROR, RSYNC_NAME ": "
+ "reverse name lookup mismatch on fd%d - spoofed address?\n",
+ fd);
+ }
+
+ freeaddrinfo(res0);
+ return name_buf;
+}
+
+
+/*******************************************************************
+this is like socketpair but uses tcp. It is used by the Samba
+regression test code
+The function guarantees that nobody else can attach to the socket,
+or if they do that this function fails and the socket gets closed
+returns 0 on success, -1 on failure
+the resulting file descriptors are symmetrical
+ ******************************************************************/
+static int socketpair_tcp(int fd[2])
+{
+ int listener;
+ struct sockaddr_in sock;
+ struct sockaddr_in sock2;
+ socklen_t socklen = sizeof(sock);
+ int connect_done = 0;
+
+ fd[0] = fd[1] = listener = -1;
+
+ memset(&sock, 0, sizeof(sock));
+
+ if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
+
+ memset(&sock2, 0, sizeof(sock2));
+#ifdef HAVE_SOCK_SIN_LEN
+ sock2.sin_len = sizeof(sock2);
+#endif
+ sock2.sin_family = PF_INET;
+
+ bind(listener, (struct sockaddr *)&sock2, sizeof(sock2));
+
+ if (listen(listener, 1) != 0) goto failed;
+
+ if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed;
+
+ if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
+
+ set_nonblocking(fd[1]);
+
+ sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+ if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) == -1) {
+ if (errno != EINPROGRESS) goto failed;
+ } else {
+ connect_done = 1;
+ }
+
+ if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed;
+
+ close(listener);
+ if (connect_done == 0) {
+ if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) != 0
+ && errno != EISCONN) goto failed;
+ }
+
+ set_blocking (fd[1]);
+
+ /* all OK! */
+ return 0;
+
+ failed:
+ if (fd[0] != -1) close(fd[0]);
+ if (fd[1] != -1) close(fd[1]);
+ if (listener != -1) close(listener);
return -1;
}
+
+
+/*******************************************************************
+run a program on a local tcp socket, this is used to launch smbd
+when regression testing
+the return value is a socket which is attached to a subprocess
+running "prog". stdin and stdout are attached. stderr is left
+attached to the original stderr
+ ******************************************************************/
+int sock_exec(const char *prog)
+{
+ int fd[2];
+ if (socketpair_tcp(fd) != 0) {
+ rprintf (FERROR, RSYNC_NAME
+ ": socketpair_tcp failed (%s)\n",
+ strerror(errno));
+ return -1;
+ }
+ if (fork() == 0) {
+ close(fd[0]);
+ close(0);
+ close(1);
+ dup(fd[1]);
+ dup(fd[1]);
+ if (verbose > 3)
+ fprintf (stderr,
+ RSYNC_NAME ": execute socket program \"%s\"\n",
+ prog);
+ exit (system (prog));
+ }
+ close (fd[1]);
+ return fd[0];
+}
+
+
+