Commit 3eb9a889 authored by Ben Greear's avatar Ben Greear Committed by Steve French
Browse files

cifs: Allow binding to local IP address. 



When using multi-homed machines, it's nice to be able to specify
the local IP to use for outbound connections.  This patch gives
cifs the ability to bind to a particular IP address.

   Usage:  mount -t cifs -o srcaddr=192.168.1.50,user=foo, ...
   Usage:  mount -t cifs -o srcaddr=2002::100:1,user=foo, ...

Acked-by: default avatarJeff Layton <jlayton@redhat.com>
Acked-by: default avatarDr. David Holder <david.holder@erion.co.uk>
Signed-off-by: default avatarBen Greear <greearb@candelatech.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 2b149f11

fs/cifs/cifsfs.c

+19 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
#include <linux/kthread.h>

#include <linux/freezer.h>

#include <linux/smp_lock.h>

#include <net/ipv6.h>

#include "cifsfs.h"

#include "cifspdu.h"

#define DECLARE_GLOBALS_HERE
@@ -367,6 +368,8 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m) 
{

	struct cifs_sb_info *cifs_sb = CIFS_SB(m->mnt_sb);

	struct cifsTconInfo *tcon = cifs_sb->tcon;

	struct sockaddr *srcaddr;

	srcaddr = (struct sockaddr *)&tcon->ses->server->srcaddr;



	seq_printf(s, ",unc=%s", tcon->treeName);

	if (tcon->ses->userName)
@@ -374,6 +377,22 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m) 
	if (tcon->ses->domainName)

		seq_printf(s, ",domain=%s", tcon->ses->domainName);



	if (srcaddr->sa_family != AF_UNSPEC) {

		struct sockaddr_in *saddr4;

		struct sockaddr_in6 *saddr6;

		saddr4 = (struct sockaddr_in *)srcaddr;

		saddr6 = (struct sockaddr_in6 *)srcaddr;

		if (srcaddr->sa_family == AF_INET6)

			seq_printf(s, ",srcaddr=%pI6c",

				   &saddr6->sin6_addr);

		else if (srcaddr->sa_family == AF_INET)

			seq_printf(s, ",srcaddr=%pI4",

				   &saddr4->sin_addr.s_addr);

		else

			seq_printf(s, ",srcaddr=BAD-AF:%i",

				   (int)(srcaddr->sa_family));

	}



	seq_printf(s, ",uid=%d", cifs_sb->mnt_uid);

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)

		seq_printf(s, ",forceuid");

fs/cifs/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -139,6 +139,7 @@ struct TCP_Server_Info { 
		struct sockaddr_in sockAddr;

		struct sockaddr_in6 sockAddr6;

	} addr;

	struct sockaddr_storage srcaddr; /* locally bind to this IP */

	wait_queue_head_t response_q;

	wait_queue_head_t request_q; /* if more than maxmpx to srvr must block*/

	struct list_head pending_mid_q;

fs/cifs/connect.c

+88 −2
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ struct smb_vol { 
	bool sockopt_tcp_nodelay:1;

	unsigned short int port;

	char *prepath;

	struct sockaddr_storage srcaddr; /* allow binding to a local IP */

	struct nls_table *local_nls;

};
@@ -1046,6 +1047,22 @@ cifs_parse_mount_options(char *options, const char *devname, 
						    "long\n");

				return 1;

			}

		} else if (strnicmp(data, "srcaddr", 7) == 0) {

			vol->srcaddr.ss_family = AF_UNSPEC;



			if (!value || !*value) {

				printk(KERN_WARNING "CIFS: srcaddr value"

				       " not specified.\n");

				return 1;	/* needs_arg; */

			}

			i = cifs_convert_address((struct sockaddr *)&vol->srcaddr,

						 value, strlen(value));

			if (i < 0) {

				printk(KERN_WARNING "CIFS:  Could not parse"

				       " srcaddr: %s\n",

				       value);

				return 1;

			}

		} else if (strnicmp(data, "prefixpath", 10) == 0) {

			if (!value || !*value) {

				printk(KERN_WARNING
@@ -1374,8 +1391,36 @@ cifs_parse_mount_options(char *options, const char *devname, 
	return 0;

}



/** Returns true if srcaddr isn't specified and rhs isn't

 * specified, or if srcaddr is specified and

 * matches the IP address of the rhs argument.

 */

static bool

srcip_matches(struct sockaddr *srcaddr, struct sockaddr *rhs)

{

	switch (srcaddr->sa_family) {

	case AF_UNSPEC:

		return (rhs->sa_family == AF_UNSPEC);

	case AF_INET: {

		struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;

		struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;

		return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);

	}

	case AF_INET6: {

		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;

		struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)&rhs;

		return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);

	}

	default:

		WARN_ON(1);

		return false; /* don't expect to be here */

	}

}





static bool

match_address(struct TCP_Server_Info *server, struct sockaddr *addr)

match_address(struct TCP_Server_Info *server, struct sockaddr *addr,

	      struct sockaddr *srcaddr)

{

	struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;

	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
@@ -1402,6 +1447,9 @@ match_address(struct TCP_Server_Info *server, struct sockaddr *addr) 
		break;

	}



	if (!srcip_matches(srcaddr, (struct sockaddr *)&server->srcaddr))

		return false;



	return true;

}
@@ -1469,7 +1517,8 @@ cifs_find_tcp_session(struct sockaddr *addr, struct smb_vol *vol) 
		if (server->tcpStatus == CifsNew)

			continue;



		if (!match_address(server, addr))

		if (!match_address(server, addr,

				   (struct sockaddr *)&vol->srcaddr))

			continue;



		if (!match_security(server, vol))
@@ -1584,6 +1633,8 @@ cifs_get_tcp_session(struct smb_vol *volume_info) 
	 * no need to spinlock this init of tcpStatus or srv_count

	 */

	tcp_ses->tcpStatus = CifsNew;

	memcpy(&tcp_ses->srcaddr, &volume_info->srcaddr,

	       sizeof(tcp_ses->srcaddr));

	++tcp_ses->srv_count;



	if (addr.ss_family == AF_INET6) {
@@ -1999,6 +2050,33 @@ static void rfc1002mangle(char *target, char *source, unsigned int length) 


}



static int

bind_socket(struct TCP_Server_Info *server)

{

	int rc = 0;

	if (server->srcaddr.ss_family != AF_UNSPEC) {

		/* Bind to the specified local IP address */

		struct socket *socket = server->ssocket;

		rc = socket->ops->bind(socket,

				       (struct sockaddr *) &server->srcaddr,

				       sizeof(server->srcaddr));

		if (rc < 0) {

			struct sockaddr_in *saddr4;

			struct sockaddr_in6 *saddr6;

			saddr4 = (struct sockaddr_in *)&server->srcaddr;

			saddr6 = (struct sockaddr_in6 *)&server->srcaddr;

			if (saddr6->sin6_family == AF_INET6)

				cERROR(1, "cifs: "

				       "Failed to bind to: %pI6c, error: %d\n",

				       &saddr6->sin6_addr, rc);

			else

				cERROR(1, "cifs: "

				       "Failed to bind to: %pI4, error: %d\n",

				       &saddr4->sin_addr.s_addr, rc);

		}

	}

	return rc;

}



static int

ipv4_connect(struct TCP_Server_Info *server)
@@ -2024,6 +2102,10 @@ ipv4_connect(struct TCP_Server_Info *server) 
		cifs_reclassify_socket4(socket);

	}



	rc = bind_socket(server);

	if (rc < 0)

		return rc;



	/* user overrode default port */

	if (server->addr.sockAddr.sin_port) {

		rc = socket->ops->connect(socket, (struct sockaddr *)
@@ -2186,6 +2268,10 @@ ipv6_connect(struct TCP_Server_Info *server) 
		cifs_reclassify_socket6(socket);

	}



	rc = bind_socket(server);

	if (rc < 0)

		return rc;



	/* user overrode default port */

	if (server->addr.sockAddr6.sin6_port) {

		rc = socket->ops->connect(socket,

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