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"
-#ifndef HAVE_GETADDRINFO
-#include "lib/addrinfo.h"
-#endif
-
-extern int af;
-
/* 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)
}
+/**
+ * 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 (getaddrinfo(bind_address, NULL, &bhints, &bres_all) == -1) {
+ 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, bres->ai_addr, bres->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 .
+/**
+ * Open a socket to a tcp remote host with the specified port .
*
- * Based on code from Warren. Proxy support by Stephen Rothwell
+ * 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.
*
- * @param bind_address Local address to use. Normally NULL to get the stack default.
+ * 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 open_socket_out(char *host, int port, const char *bind_address,
+ int af_hint)
{
int type = SOCK_STREAM;
int error;
}
memset(&hints, 0, sizeof(hints));
- hints.ai_family = af;
+ hints.ai_family = af_hint;
hints.ai_socktype = type;
error = getaddrinfo(h, portbuf, &hints, &res0);
if (error) {
- rprintf(FERROR, "getaddrinfo: %s\n", gai_strerror(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, "getaddrinfo: %s\n", 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, "getaddrinfo: resolved to multiple hosts\n");
- freeaddrinfo(bres);
- continue;
- }
- bind(s, bres->ai_addr, bres->ai_addrlen);
- }
if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
close(s);
}
freeaddrinfo(res0);
if (s < 0) {
- rprintf(FERROR, "failed to connect to %s - %s\n", h, strerror(errno));
+ rprintf(FERROR, RSYNC_NAME ": failed to connect to %s: %s\n",
+ h, strerror(errno));
return -1;
}
return s;
**/
int open_socket_out_wrapped (char *host,
int port,
- const char *bind_address)
+ 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);
+ 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)
+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;
+ struct addrinfo hints, *all_ai, *resp;
char portbuf[10];
int error;
memset(&hints, 0, sizeof(hints));
- hints.ai_family = af;
+ 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);
+ error = getaddrinfo(bind_address, portbuf, &hints, &all_ai);
if (error) {
- rprintf(FERROR, "getaddrinfo: %s\n", gai_strerror(error));
- return -1;
- }
- if (res->ai_next) {
- rprintf(FERROR, "getaddrinfo: resolved to multiple hosts\n");
- freeaddrinfo(res);
+ rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",
+ bind_address, gai_strerror(error));
return -1;
}
- s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
- if (s < 0) {
- rprintf(FERROR, RSYNC_NAME ": socket failed\n");
- freeaddrinfo(res);
- return -1;
- }
-
- setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one));
+ /* 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);
- /* 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);
- freeaddrinfo(res);
- close(s);
- return -1;
+ 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;
+ }
+
+ return s;
}
- return s;
+ rprintf(FERROR, RSYNC_NAME ": open inbound socket on port %d failed: "
+ "%s\n",
+ port,
+ strerror(errno));
+
+ 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);
+ s = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);
if (s == -1)
exit_cleanup(RERR_SOCKETIO);
fd_set fds;
int fd;
struct sockaddr_storage addr;
- int in_addrlen = sizeof(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
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;
}
}
-/*******************************************************************
- 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_storage ss;
}
-/*******************************************************************
- 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_storage ss;
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 (ss.ss_family == AF_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;
error = getaddrinfo(name_buf, port_buf, &hints, &res0);
if (error) {
strcpy(name_buf, def);
- rprintf(FERROR, "forward name lookup failed\n");
+ 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.ss_family)
+ if (res->ai_family != get_sockaddr_family(&ss))
continue;
if (res->ai_addrlen != length)
continue;
break;
}
- /* TODO: Do a forward lookup as well to prevent spoofing */
+ /* TODO: Do a forward lookup as well to prevent spoofing */
if (res == NULL) {
strcpy(name_buf, def);
- rprintf(FERROR,
- "reverse name lookup mismatch - spoofed address?\n");
+ rprintf(FERROR, RSYNC_NAME ": "
+ "reverse name lookup mismatch on fd%d - spoofed address?\n",
+ fd);
}
freeaddrinfo(res0);
return name_buf;
}
-/**
- Convert a string to an IP address. The string can be a name or
- dotted decimal number.
-
- Returns a pointer to a static in_addr struct -- if you call this
- more than once then you should copy it.
-*/
-struct in_addr *ip_address(const char *str)
-{
- static struct in_addr ret;
- struct hostent *hp;
-
- if (!str) {
- rprintf (FERROR, "ip_address received NULL name\n");
- return NULL;
- }
-
- /* try as an IP address */
- if (inet_aton(str, &ret) != 0) {
- return &ret;
- }
-
- /* otherwise assume it's a network name of some sort and use
- gethostbyname */
- if ((hp = gethostbyname (str)) == 0) {
- rprintf(FERROR, "gethostbyname failed for \"%s\": unknown host?\n",str);
- return NULL;
- }
-
- if (hp->h_addr == NULL) {
- rprintf(FERROR, "gethostbyname: host address is invalid for host \"%s\"\n",str);
- return NULL;
- }
-
- if (hp->h_length > sizeof ret) {
- rprintf(FERROR, "gethostbyname: host address for \"%s\" is too large\n",
- str);
- return NULL;
- }
-
- if (hp->h_addrtype != AF_INET) {
- rprintf (FERROR, "gethostname: host address for \"%s\" is not IPv4\n",
- str);
- return NULL;
- }
-
- /* This is kind of difficult. The only field in ret is
- s_addr, which is the IP address as a 32-bit int. On
- UNICOS, s_addr is in fact a *bitfield* for reasons best
- know to Cray. This means we can't memcpy in to it. On the
- other hand, h_addr is a char*, so we can't just assign.
-
- Since there's meant to be only one field inside the in_addr
- structure we will try just copying over the top and see how
- that goes. */
- memcpy (&ret, hp->h_addr, hp->h_length);
-
- return &ret;
-}
-
-
/*******************************************************************
this is like socketpair but uses tcp. It is used by the Samba
Matt McCutchen's Web Site / rsync / rsync.git / blobdiff