X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/e22de16264d3c5a05b3869692af52b1ccdf3aa80..7c583c73160714a2f61034515adb1a4a32f9d818:/socket.c diff --git a/socket.c b/socket.c index 27260a1b..0ad8a169 100644 --- a/socket.c +++ b/socket.c @@ -1,5 +1,7 @@ -/* - Copyright (C) Andrew Tridgell 1998 +/* -*- c-file-style: "linux" -*- + + Copyright (C) 1992-2001 by Andrew Tridgell + Copyright (C) 2001 by Martin Pool 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 @@ -16,121 +18,357 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -/* - socket functions used in rsync - - */ +/** + * @file socket.c + * + * Socket functions used in rsync. + **/ #include "rsync.h" -/* open a socket to a tcp remote host with the specified port - based on code from Warren */ -int open_socket_out(char *host, int port) +/* 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) { - int type = SOCK_STREAM; - struct sockaddr_in sock_out; - int res; - struct hostent *hp; - + char buffer[1024]; + char *cp; - res = socket(PF_INET, type, 0); - if (res == -1) { + 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; } - hp = gethostbyname(host); - if (!hp) { - rprintf(FERROR,"unknown host: %s\n", host); + 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; +} - memcpy(&sock_out.sin_addr, hp->h_addr, hp->h_length); - sock_out.sin_port = htons(port); - sock_out.sin_family = PF_INET; - if (connect(res,(struct sockaddr *)&sock_out,sizeof(sock_out))) { - close(res); - rprintf(FERROR,"failed to connect to %s - %s\n", host, strerror(errno)); + +/** + * 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; } - return res; + s = -1; + /* Try to connect to all addresses for this machine until we get + * through. It might e.g. be multi-homed, or have both IPv4 and IPv6 + * addresses. We need to create a socket for each record, since the + * address record tells us what protocol to use to try to connect. */ + 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 : %s\n", + bind_address, gai_strerror(error)); + continue; + } + if (bres->ai_next) { + /* I'm not at all sure that this is the right + * response here... -- mbp */ + 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 a socket of the specified type, port and address for incoming data -****************************************************************************/ -static int open_socket_in(int type, int port) +/** + * 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) { - struct hostent *hp; - struct sockaddr_in sock; - char host_name[200]; - int res; - int one=1; + char *prog; + + if ((prog = getenv ("RSYNC_CONNECT_PROG")) != NULL) + return sock_exec (prog); + else + return open_socket_out (host, port, bind_address, + af_hint); +} - /* get my host name */ - if (gethostname(host_name, sizeof(host_name)) == -1) { - rprintf(FERROR,"gethostname failed\n"); - return -1; - } - /* get host info */ - if ((hp = gethostbyname(host_name)) == 0) { - rprintf(FERROR,"gethostbyname: Unknown host %s\n",host_name); + +/** + * 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; } - - bzero((char *)&sock,sizeof(sock)); - memcpy((char *)&sock.sin_addr,(char *)hp->h_addr, hp->h_length); - sock.sin_port = htons(port); - sock.sin_family = hp->h_addrtype; - sock.sin_addr.s_addr = INADDR_ANY; - res = socket(hp->h_addrtype, type, 0); - if (res == -1) { - rprintf(FERROR,"socket failed\n"); - 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: + case EINVAL: + /* 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(res,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); + setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); /* now we've got a socket - we need to bind it */ - if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) == -1) { - rprintf(FERROR,"bind failed on port %d\n", port); - close(res); - return -1; + 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 res; + return s; + +fail: + freeaddrinfo(res); + return -1; } -/**************************************************************************** -determine if a file descriptor is in fact a socket -****************************************************************************/ +/* + * Determine if a file descriptor is in fact a socket + */ int is_a_socket(int fd) { - int v,l; - l = sizeof(int); - return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0); + 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; - - signal(SIGCHLD, SIG_IGN); + extern char *bind_address; /* open an incoming socket */ - s = open_socket_in(SOCK_STREAM, port); + s = open_socket_in(SOCK_STREAM, port, bind_address, + global_opts.af_hint); if (s == -1) - exit(1); + exit_cleanup(RERR_SOCKETIO); /* ready to listen */ if (listen(s, 5) == -1) { close(s); - exit(1); + exit_cleanup(RERR_SOCKETIO); } @@ -139,8 +377,13 @@ void start_accept_loop(int port, int (*fn)(int )) while (1) { fd_set fds; int fd; - struct sockaddr addr; - int in_addrlen = sizeof(addr); + struct sockaddr_storage addr; + int 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); @@ -151,13 +394,24 @@ void start_accept_loop(int port, int (*fn)(int )) if(!FD_ISSET(s, &fds)) continue; - fd = accept(s,&addr,&in_addrlen); + fd = accept(s,(struct sockaddr *)&addr,&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)); } @@ -216,6 +470,8 @@ 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"); @@ -261,7 +517,8 @@ void set_socket_options(int fd, char *options) } if (ret != 0) - rprintf(FERROR,"Failed to set socket option %s\n",tok); + rprintf(FERROR, "failed to set socket option %s: %s\n", tok, + strerror(errno)); } free(options); @@ -272,72 +529,254 @@ become a daemon, discarding the controlling terminal ****************************************************************************/ void become_daemon(void) { - if (fork()) + int i; + + if (fork()) { _exit(0); + } /* detach from the terminal */ #ifdef HAVE_SETSID setsid(); #else #ifdef TIOCNOTTY - { - int i = open("/dev/tty", O_RDWR); - if (i >= 0) - { - ioctl(i, (int) TIOCNOTTY, (char *)0); - close(i); - } + i = open("/dev/tty", O_RDWR); + if (i >= 0) { + ioctl(i, (int) TIOCNOTTY, (char *)0); + close(i); } #endif /* TIOCNOTTY */ #endif - close(0); - close(1); - close(2); + /* 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 - ******************************************************************/ +/** + * Return the IP addr of the client as a string + **/ char *client_addr(int fd) { - struct sockaddr sa; - struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); - int length = sizeof(sa); + struct sockaddr_storage ss; + int length = sizeof(ss); static char addr_buf[100]; + static int initialised; - if (getpeername(fd, &sa, &length)) { - exit(1); - } + if (initialised) return addr_buf; - strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf)-1); + initialised = 1; + + if (getpeername(fd, (struct sockaddr *)&ss, &length)) { + exit_cleanup(RERR_SOCKETIO); + } + getnameinfo((struct sockaddr *)&ss, length, + addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST); return addr_buf; } -/******************************************************************* - return the DNS name of the client - ******************************************************************/ +static int get_sockaddr_family(const struct sockaddr_storage *ss) +{ + return ((struct sockaddr *) ss)->sa_family; +} + + +/** + * Return the DNS name of the client + **/ char *client_name(int fd) { - struct sockaddr sa; - struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); - int length = sizeof(sa); + struct sockaddr_storage ss; + int length = sizeof(ss); static char name_buf[100]; - struct hostent *hp; + 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,"UNKNOWN"); + strcpy(name_buf,def); - if (getpeername(fd, &sa, &length)) { - exit(1); + 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); } - /* Look up the remote host name. */ - if ((hp = gethostbyaddr((char *) &sockin->sin_addr, - sizeof(sockin->sin_addr), - AF_INET))) { - strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf) - 1); +#ifdef INET6 + if (get_sockaddr_family(&ss) == 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 != get_sockaddr_family(&ss)) + 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]; +} + + +