X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/2be5d2daad47684b5d2728652c4a80bf8846a507..32f761755e2cfee243a1513c9ea9871586463fa6:/socket.c diff --git a/socket.c b/socket.c index 8e895ca8..bb7acc06 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 @@ -22,23 +24,27 @@ * @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" -#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. */ +/** + * Establish a proxy connection on an open socket to a web proxy by + * using the HTTP 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)) { + if (write(fd, buffer, strlen(buffer)) != (int) strlen(buffer)) { rprintf(FERROR, "failed to write to proxy: %s\n", strerror(errno)); return -1; @@ -64,7 +70,7 @@ static int establish_proxy_connection(int fd, char *host, int port) buffer); return -1; } - for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++) + for (cp = &buffer[5]; isdigit(* (unsigned char *) cp) || (*cp == '.'); cp++) ; while (*cp == ' ') cp++; @@ -94,6 +100,41 @@ 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; + freeaddrinfo(bres_all); + 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. */ + freeaddrinfo(bres_all); + return -1; +} + /** * Open a socket to a tcp remote host with the specified port . @@ -121,7 +162,6 @@ 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; @@ -146,6 +186,10 @@ int open_socket_out(char *host, int port, const char *bind_address, *cp++ = '\0'; strcpy(portbuf, cp); h = buffer; + if (verbose >= 2) { + rprintf(FINFO, "connection via http proxy %s port %s\n", + h, portbuf); + } } else { snprintf(portbuf, sizeof(portbuf), "%d", port); h = host; @@ -162,32 +206,22 @@ int open_socket_out(char *host, int port, const char *bind_address, } 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) { - 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); @@ -263,7 +297,7 @@ 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; @@ -272,53 +306,44 @@ 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: - /* 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; - } + /* 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); - setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); + 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; + } - /* 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; + freeaddrinfo(all_ai); + 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; } @@ -353,10 +378,10 @@ 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); @@ -371,9 +396,10 @@ void start_accept_loop(int port, int (*fn)(int )) for each incoming connection */ while (1) { fd_set fds; + pid_t pid; int fd; - struct sockaddr addr; - int in_addrlen = sizeof(addr); + struct sockaddr_storage 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 @@ -389,7 +415,7 @@ void start_accept_loop(int port, int (*fn)(int )) if(!FD_ISSET(s, &fds)) continue; - fd = accept(s,(struct sockaddr *)&addr,&in_addrlen); + fd = accept(s,(struct sockaddr *)&addr,&addrlen); if (fd == -1) continue; @@ -402,15 +428,26 @@ void start_accept_loop(int port, int (*fn)(int )) while (waitpid(-1, NULL, WNOHANG) > 0); #endif - if (fork()==0) { + if ((pid = fork()) == 0) { close(s); /* open log file in child before possibly giving up privileges */ log_open(); _exit(fn(fd)); + } else if (pid < 0) { + rprintf(FERROR, + RSYNC_NAME + ": could not create child server process: %s\n", + strerror(errno)); + close(fd); + /* This might have happened because we're + * overloaded. Sleep briefly before trying to + * accept again. */ + sleep(2); + } else { + /* Parent doesn't need this fd anymore. */ + close(fd); } - - close(fd); } } @@ -459,9 +496,9 @@ struct -/**************************************************************************** -set user socket options -****************************************************************************/ +/** + * Set user socket options + **/ void set_socket_options(int fd, char *options) { char *tok; @@ -519,9 +556,9 @@ void set_socket_options(int fd, char *options) free(options); } -/**************************************************************************** -become a daemon, discarding the controlling terminal -****************************************************************************/ +/** + * Become a daemon, discarding the controlling terminal + **/ void become_daemon(void) { int i; @@ -550,132 +587,16 @@ void become_daemon(void) } } -/** - * 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 + * 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. **/ -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", - 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; @@ -691,7 +612,7 @@ static int socketpair_tcp(int fd[2]) if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed; memset(&sock2, 0, sizeof(sock2)); -#ifdef HAVE_SOCK_SIN_LEN +#ifdef HAVE_SOCKADDR_LEN sock2.sin_len = sizeof(sock2); #endif sock2.sin_family = PF_INET; @@ -735,16 +656,20 @@ static int socketpair_tcp(int fd[2]) } -/******************************************************************* -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 - ******************************************************************/ + +/** + * Run a program on a local tcp socket, so that we can talk to it's + * stdin and stdout. This is used to fake a connection to a daemon + * for testing -- not for the normal case of running SSH. + * + * @return 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", @@ -757,10 +682,12 @@ int sock_exec(const char *prog) close(1); dup(fd[1]); dup(fd[1]); - if (verbose > 3) + if (verbose > 3) { + /* Can't use rprintf because we've forked. */ fprintf (stderr, RSYNC_NAME ": execute socket program \"%s\"\n", prog); + } exit (system (prog)); } close (fd[1]);