X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/bc2e93eb8e6562590492e39349b37c38711a05ce..7c583c73160714a2f61034515adb1a4a32f9d818:/socket.c diff --git a/socket.c b/socket.c index 71aa6c2a..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 @@ -16,12 +18,765 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +/** + * @file socket.c + * + * Socket functions used in rsync. + **/ + +#include "rsync.h" + +/* 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; + /* 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 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: + 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(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_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(); -int open_socket_out(char *host, int port) + 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,&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); + } + + /* 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_storage ss; + int length = sizeof(ss); + static char addr_buf[100]; + static int initialised; + + if (initialised) return addr_buf; + + 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; +} + + +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_storage 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 (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]; +} + + +