X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/cb1bcc7ebbb84a056a63fd09e47c456509c52411..d54765c44250fdef784f1d1d540690fe246048b6:/socket.c diff --git a/socket.c b/socket.c index 0ad8a169..a01499eb 100644 --- a/socket.c +++ b/socket.c @@ -1,7 +1,9 @@ /* -*- c-file-style: "linux" -*- + rsync -- fast file replication program + Copyright (C) 1992-2001 by Andrew Tridgell - Copyright (C) 2001 by Martin Pool + Copyright (C) 2001, 2002 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 @@ -22,6 +24,11 @@ * @file socket.c * * Socket functions used in rsync. + * + * This file is now converted to use the new-style getaddrinfo() + * interface, which supports IPv6 but is also supported on recent + * IPv4-only machines. On systems that don't have that interface, we + * emulate it using the KAME implementation. **/ #include "rsync.h" @@ -90,6 +97,39 @@ static int establish_proxy_connection(int fd, char *host, int port) } +/** + * Try to set the local address for a newly-created socket. Return -1 + * if this fails. + **/ +int try_bind_local(int s, + int ai_family, int ai_socktype, + const char *bind_address) +{ + int error; + struct addrinfo bhints, *bres_all, *r; + + memset(&bhints, 0, sizeof(bhints)); + bhints.ai_family = ai_family; + bhints.ai_socktype = ai_socktype; + bhints.ai_flags = AI_PASSIVE; + if ((error = getaddrinfo(bind_address, NULL, &bhints, &bres_all))) { + rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n", + bind_address, gai_strerror(error)); + return -1; + } + + for (r = bres_all; r; r = r->ai_next) { + if (bind(s, r->ai_addr, r->ai_addrlen) == -1) + continue; + return s; + } + + /* no error message; there might be some problem that allows + * creation of the socket but not binding, perhaps if the + * machine has no ipv6 address of this name. */ + return -1; +} + /** * Open a socket to a tcp remote host with the specified port . @@ -117,7 +157,6 @@ int open_socket_out(char *host, int port, const char *bind_address, int type = SOCK_STREAM; int error; int s; - int result; struct addrinfo hints, *res0, *res; char portbuf[10]; char *h; @@ -167,31 +206,13 @@ int open_socket_out(char *host, int port, const char *bind_address, 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); + if (bind_address) + if (try_bind_local(s, res->ai_family, type, + bind_address) == -1) { + close(s); + s = -1; continue; } - bind(s, bres->ai_addr, bres->ai_addrlen); - } if (connect(s, res->ai_addr, res->ai_addrlen) < 0) { close(s); @@ -267,7 +288,7 @@ static int open_socket_in(int type, int port, const char *bind_address, { int one=1; int s; - struct addrinfo hints, *res, *resp; + struct addrinfo hints, *all_ai, *resp; char portbuf[10]; int error; @@ -276,54 +297,43 @@ static int open_socket_in(int type, int port, const char *bind_address, hints.ai_socktype = type; hints.ai_flags = AI_PASSIVE; snprintf(portbuf, sizeof(portbuf), "%d", port); - error = getaddrinfo(bind_address, portbuf, &hints, &res); + error = getaddrinfo(bind_address, portbuf, &hints, &all_ai); 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; - } + /* We may not be able to create the socket, if for example the + * machine knows about IPv6 in the C library, but not in the + * kernel. */ + for (resp = all_ai; resp; resp = resp->ai_next) { + s = socket(resp->ai_family, resp->ai_socktype, + resp->ai_protocol); + + if (s == -1) + /* See if there's another address that will work... */ + continue; + + setsockopt(s, SOL_SOCKET, SO_REUSEADDR, + (char *)&one, sizeof one); + + /* now we've got a socket - we need to bind it */ + if (bind(s, all_ai->ai_addr, all_ai->ai_addrlen) < 0) { + /* Nope, try another */ + close(s); + 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; } - return s; + rprintf(FERROR, RSYNC_NAME ": open inbound socket on port %d failed: " + "%s\n", + port, + strerror(errno)); -fail: - freeaddrinfo(res); + freeaddrinfo(all_ai); return -1; } @@ -358,10 +368,10 @@ void start_accept_loop(int port, int (*fn)(int )) { int s; extern char *bind_address; + extern int default_af_hint; /* open an incoming socket */ - s = open_socket_in(SOCK_STREAM, port, bind_address, - global_opts.af_hint); + s = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint); if (s == -1) exit_cleanup(RERR_SOCKETIO); @@ -378,7 +388,7 @@ void start_accept_loop(int port, int (*fn)(int )) fd_set fds; int fd; struct sockaddr_storage addr; - int addrlen = sizeof(addr); + socklen_t addrlen = sizeof addr; /* close log file before the potentially very long select so file can be trimmed by another process instead of growing @@ -561,7 +571,7 @@ void become_daemon(void) char *client_addr(int fd) { struct sockaddr_storage ss; - int length = sizeof(ss); + socklen_t length = sizeof ss; static char addr_buf[100]; static int initialised; @@ -591,7 +601,7 @@ static int get_sockaddr_family(const struct sockaddr_storage *ss) char *client_name(int fd) { struct sockaddr_storage ss; - int length = sizeof(ss); + socklen_t length = sizeof ss; static char name_buf[100]; static char port_buf[100]; char *def = "UNKNOWN"; @@ -615,6 +625,12 @@ char *client_name(int fd) #ifdef INET6 if (get_sockaddr_family(&ss) == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&ss)->sin6_addr)) { + /* OK, so ss is in the IPv6 family, but it is really + * an IPv4 address: something like + * "::ffff:10.130.1.2". If we use it as-is, then the + * reverse lookup might fail or perhaps something else + * bad might happen. So instead we convert it to an + * equivalent address in the IPv4 address family. */ struct sockaddr_in6 sin6; struct sockaddr_in *sin; @@ -627,6 +643,9 @@ char *client_name(int fd) sin->sin_len = length; #endif sin->sin_port = sin6.sin6_port; + /* FIXME: Isn't there a macro we can use here rather + * than grovelling through the struct? It might be + * wrong on some systems. */ memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12], sizeof(sin->sin_addr)); } @@ -665,13 +684,11 @@ char *client_name(int fd) 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); + "reverse name lookup for \"%s\" failed on fd%d - spoofed address? \n", + name_buf, fd); } freeaddrinfo(res0);