/* -*- c-file-style: "linux" -*-
+ rsync -- fast file replication program
+
Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>
- Copyright (C) 2001 by Martin Pool <mbp@samba.org>
+ Copyright (C) 2001, 2002 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
* @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
+static int lookup_name(const struct sockaddr_storage *ss,
+ socklen_t ss_len,
+ char *name_buf, size_t name_buf_len,
+ char *port_buf, size_t port_buf_len);
+
+static int check_name(const struct sockaddr_storage *ss,
+ socklen_t ss_len,
+ const char *name_buf,
+ const char *port_buf);
/* Establish a proxy connection on an open socket to a web roxy by
* using the CONNECT method. */
}
+/**
+ * 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 .
int type = SOCK_STREAM;
int error;
int s;
- int result;
struct addrinfo hints, *res0, *res;
char portbuf[10];
char *h;
}
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 <noport>: %s\n",
- bind_address, gai_strerror(error));
+ if (bind_address)
+ if (try_bind_local(s, res->ai_family, type,
+ bind_address) == -1) {
+ close(s);
+ s = -1;
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);
{
int one=1;
int s;
- struct addrinfo hints, *res, *resp;
+ struct addrinfo hints, *all_ai, *resp;
char portbuf[10];
int error;
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;
- }
+ /* 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;
}
{
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);
while (1) {
fd_set fds;
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
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;
**/
char *client_addr(int fd)
{
- struct sockaddr ss;
- int length = sizeof(ss);
+ struct sockaddr_storage ss;
+ socklen_t length = sizeof ss;
static char addr_buf[100];
static int initialised;
initialised = 1;
- if (getpeername(fd, &ss, &length)) {
+ if (getpeername(fd, (struct sockaddr *)&ss, &length)) {
exit_cleanup(RERR_SOCKETIO);
}
- getnameinfo(&ss, length,
+ 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
+ * Return the DNS name of the client.
+ *
+ * The name is statically cached so that repeated lookups are quick,
+ * so there is a limit of one lookup per customer.
**/
char *client_name(int fd)
{
- struct sockaddr ss;
- int length = sizeof(ss);
+ struct sockaddr_storage ss;
+ socklen_t ss_len = 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)) {
+ if (getpeername(fd, (struct sockaddr *)&ss, &ss_len)) {
/* FIXME: Can we really not continue? */
rprintf(FERROR, RSYNC_NAME ": getpeername on fd%d failed: %s\n",
- strerror(errno));
+ fd, strerror(errno));
exit_cleanup(RERR_SOCKETIO);
}
+ if (!lookup_name(&ss, ss_len, name_buf, sizeof name_buf, port_buf, sizeof port_buf))
+ check_name(&ss, ss_len, name_buf, port_buf);
+
+ return name_buf;
+}
+
+
+/**
+ * Look up a name from @p ss into @p name_buf.
+ **/
+static int lookup_name(const struct sockaddr_storage *ss,
+ socklen_t ss_len,
+ char *name_buf, size_t name_buf_len,
+ char *port_buf, size_t port_buf_len)
+{
+ int name_err;
+ const char *def = "UNKNOWN";
+
#ifdef INET6
- if (ss.sa_family == AF_INET6 &&
- IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
+ 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;
- memcpy(&sin6, &ss, sizeof(sin6));
- sin = (struct sockaddr_in *)&ss;
+ 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);
+ ss_len = sizeof(struct sockaddr_in);
#ifdef HAVE_SOCKADDR_LEN
- sin->sin_len = length;
+ sin->sin_len = ss_len;
#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));
}
#endif
/* reverse lookup */
- if (getnameinfo((struct sockaddr *)&ss, length,
- name_buf, sizeof(name_buf), port_buf, sizeof(port_buf),
- NI_NAMEREQD | NI_NUMERICSERV) != 0) {
+ if (!(name_err = getnameinfo((struct sockaddr *) ss, ss_len,
+ name_buf, name_buf_len,
+ port_buf, port_buf_len,
+ NI_NAMEREQD | NI_NUMERICSERV))) {
strcpy(name_buf, def);
- rprintf(FERROR, "reverse name lookup failed\n");
+ rprintf(FERROR, RSYNC_NAME ": reverse name lookup failed: %s\n",
+ gai_strerror(name_err));
+ return name_err;
}
- /* forward lookup */
+ return 0;
+}
+
+
+
+/* Do a forward lookup on name_buf and make sure it corresponds to ss
+ * -- otherwise we may be being spoofed. If we suspect we are, then
+ * we don't abort the connection but just emit a warning. */
+static int check_name(const struct sockaddr_storage *ss,
+ socklen_t ss_len,
+ const char *name_buf,
+ const char *port_buf)
+{
+ struct addrinfo hints, *res, *res0;
+ int error;
+
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);
+ /* We still use the name found by the reverse lookup,
+ * but emit a warning. */
rprintf(FERROR,
- RSYNC_NAME ": forward name lookup for %s failed: %s\n",
- port_buf,
+ RSYNC_NAME ": forward name lookup for %s:%s failed: %s\n",
+ name_buf, port_buf,
gai_strerror(error));
- return name_buf;
+ return error;
}
- /* XXX sin6_flowinfo and other fields */
+
+ /* We expect that one of the results will be the same as ss. */
for (res = res0; res; res = res->ai_next) {
- if (res->ai_family != ss.sa_family)
+ if (res->ai_family != get_sockaddr_family(ss))
continue;
- if (res->ai_addrlen != length)
+ if (res->ai_addrlen != ss_len)
continue;
- if (memcmp(res->ai_addr, &ss, res->ai_addrlen) == 0)
+ 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);
+ /* We hit the end of the list without finding an
+ * address that was the same as ss. */
+ rprintf(FERROR, RSYNC_NAME
+ ": no address record for \"%s\" corresponds to peer name: spoofed address?\n",
+ name_buf);
}
freeaddrinfo(res0);
- return name_buf;
+ return 0;
}
Matt McCutchen's Web Site / rsync / rsync.git / blobdiff